Search results for: organizational and economic structure

Authors: O. Squillace, R. L. Thompson

Abstract:

Migration of small molecules to, and across the surface of polymer matrices is a little-studied problem with important industrial applications. Tackifiers in adhesives, flavors in foods and binding agents in paints all present situations where the function of a product depends on the ability of small molecules to migrate through a polymer matrix to achieve the desired properties such as softness, dispersion of fillers, and to deliver an effect that is felt (or tasted) on a surface. It’s been shown that the chemical and molecular structure, surface free energies, phase behavior, close environment and compatibility of the system, influence the migrants’ motion. When differences in behavior, such as occurrence of segregation to the surface or not, are observed it is then of crucial importance to identify and get a better understanding of the driving forces involved in the process of molecular migration. In this aim, experience is meant to be allied with theory in order to deliver a validated theoretical and computational toolkit to describe and predict these phenomena. The systems that have been chosen for this study aim to address the effect of polarity mismatch between the migrants and the polymer matrix and that of a second migrant over the first one. As a non-polar resin polymer, polyvinyl acetate is used as the material to which more or less polar migrants (sorbitol, carvone, octanoic acid (OA), triacetin) are to be added. Through contact angle measurement a surface excess is seen for sorbitol (polar) mixed with PVAc as the surface energy is lowered compare to the one of pure PVAc. This effect is increased upon the addition of carvon or triacetin (non-polars). Surface micro-structures are also evidenced by atomic force microscopy (AFM). Ion beam analysis (Nuclear Reaction Analysis), supplemented by neutron reflectometry can accurately characterize the self-organization of surfactants, oligomers, aromatic molecules in polymer films in order to relate the macroscopic behavior to the length scales that are amenable to simulation. The nuclear reaction analysis (NRA) data for deuterated OA 20% shows the evidence of a surface excess which is enhanced after annealing. The addition of 10% triacetin, as a second migrant, results in the formation of an underlying layer enriched in triacetin below the surface excess of OA. The results show that molecules in polarity mismatch with the matrix tend to segregate to the surface, and this is favored by the addition of a second migrant of the same polarity than the matrix. As studies have been restricted to materials that are model supported films under static conditions in a first step, it is also wished to address the more challenging conditions of materials under controlled stress or strain. To achieve this, a simple rig and PDMS cell have been designed to stretch the material to a defined strain and to probe these mechanical effects by ion beam analysis and atomic force microscopy. This will make a significant step towards exploring the influence of extensional strain on surface segregation, flavor release in cross-linked rubbers.

Keywords: polymers, surface segregation, thin films, molecular migration

Procedia PDF Downloads 100

Authors: Arti Singh, Carolyn Jenkins, Oyedunni S. Arulogun, Mayowa O. Owolabi, Fred S. Sarfo, Bruce Ovbiagele, Enzinne Sylvia

Abstract:

Background: Stroke, the leading cause of adult-onset disability and the second leading cause of death, is a major public health concern particularly pertinent in Sub-Saharan Africa (SSA), where nearly 80% of all global stroke mortalities occur. The Stroke Investigative Research and Education Network (SIREN) seeks to comprehensively characterize the genomic, sociocultural, economic, and behavioral risk factors for stroke and to build effective teams for research to address and decrease the burden of stroke and other non communicable diseases in SSA. One of the first steps to address this goal was to effectively engage the communities that suffer the high burden of disease in SSA. This study describes how the SIREN project engaged six sites in Ghana and Nigeria over the past three years, describing the community engagement activities that have arisen since inception. Aim: The aim of community engagement (CE) within SIREN is to elucidate information about knowledge, attitudes, beliefs, and practices (KABP) about stroke and its risk factors from individuals of African ancestry in SSA, and to educate the community about stroke and ways to decrease disabilities and deaths from stroke using socioculturally appropriate messaging and messengers. Methods: Community Advisory Board (CABs), Focus Group Discussions (FGDs) and community outreach programs. Results: 27 FGDs with 168 participants including community heads, religious leaders, health professionals and individuals with stroke among others, were conducted, and over 60 CE outreaches have been conducted within the SIREN performance sites. Over 5,900 individuals have received education on cardiovascular risk factors and about 5,000 have been screened for cardiovascular risk factors during the outreaches. FGDs and outreach programs indicate that knowledge of stroke, as well as risk factors and follow-up evidence-based care is limited and often late. Other findings include: 1) Most recognize hypertension as a major risk factor for stroke. 2) About 50% report that stroke is hereditary and about 20% do not know organs affected by stroke. 3) More than 95% willing to participate in genetic testing research and about 85% willing to pay for testing and recommend the test to others. 4) Almost all indicated that genetic testing could help health providers better treat stroke and help scientists better understand the causes of stroke. The CABs provided stakeholder input into SIREN activities and facilitated collaborations among investigators, community members and stakeholders. Conclusion: The CE core within SIREN is a first-of-its kind public outreach engagement initiative to evaluate and address perceptions about stroke and genomics by patients, caregivers, and local leaders in SSA and has implications as a model for assessment in other high-stroke risk populations. SIREN’s CE program uses best practices to build capacity for community-engaged research, accelerate integration of research findings into practice and strengthen dynamic community-academic partnerships within our communities. CE has had several major successes over the past three years including our multi-site collaboration examining the KABP about stroke (symptoms, risk factors, burden) and genetic testing across SSA.

Keywords: community advisory board, community engagement, focus groups, outreach, SSA, stroke

Procedia PDF Downloads 405

Authors: M. Shiva Prasad, S. R. Atchuta, T. Vijayaraghavan, S. Sakthivel

Abstract:

The world is in need of efficient energy conversion technologies which are affordable, accessible, and sustainable with eco-friendly nature. Solar energy is one of the cornerstones for the world’s economic growth because of its abundancy with zero carbon pollution. Among the various solar energy conversion technologies, solar thermal technology has attracted a substantial renewed interest due to its diversity and compatibility in various applications. Solar thermal systems employ concentrators, tracking systems and heat engines for electricity generation which lead to high cost and complexity in comparison with photovoltaics; however, it is compatible with distinct thermal energy storage capability and dispatchable electricity which creates a tremendous attraction. Apart from that, employing cost-effective solar selective receiver tube in a concentrating solar thermal (CST) system improves the energy conversion efficiency and directly reduces the cost of technology. In addition, the development of solar receiver tubes by low cost methods which can offer high optical properties and corrosion resistance in an open-air atmosphere would be beneficial for low and medium temperature applications. In this regard, our work opens up an approach which has the potential to achieve cost-effective energy conversion. We have developed a highly selective tandem absorber coating through a facile wet chemical route by a combination of chemical oxidation, sol-gel, and nanoparticle coating methods. The developed tandem absorber coating has gradient refractive index nature on stainless steel (SS 304) and exhibited high optical properties (α ≤ 0.95 & ε ≤ 0.14). The first absorber layer (Cr-Mn-Fe oxides) developed by controlled oxidation of SS 304 in a chemical bath reactor. A second composite layer of ZrO₂-SiO₂ has been applied on the chemically oxidized substrate by So-gel dip coating method to serve as optical enhancing and corrosion resistant layer. Finally, an antireflective layer (MgF₂) has been deposited on the second layer, to achieve > 95% of absorption. The developed tandem layer exhibited good thermal stability up to 250 °C in open air atmospheric condition and superior corrosion resistance (withstands for > 200h in salt spray test (ASTM B117)). After the successful development of a coating with targeted properties at a laboratory scale, a prototype of the 1 m tube has been demonstrated with excellent uniformity and reproducibility. Moreover, it has been validated under standard laboratory test condition as well as in field condition with a comparison of the commercial receiver tube. The presented strategy can be widely adapted to develop highly selective coatings for a variety of CST applications ranging from hot water, solar desalination, and industrial process heat and power generation. The high-performance, cost-effective medium temperature receiver tube technology has attracted many industries, and recently the technology has been transferred to Indian industry.

Keywords: concentrated solar thermal system, solar selective coating, tandem absorber, ultralow refractive index

Procedia PDF Downloads 72

Authors: Elena Ionescu, Elena Iacob, Marie-Louise Ionescu, Carmen Elena Tebrencu, Oana Teodora Ciuperca

Abstract:

Echinacea species (Asteraceae) has received a global attention because it is widely used for treatment of cold, flu and upper respiratory tract infections. Echinacea species contain a great variety of chemical components that contribute to their activity. The most important components responsible for the biological activity are those with high molecular-weight such as polysaccharides, polyacetylenes, highly unsaturated alkamides and caffeic acid derivatives. The principal factors that may influence the chemical composition of Echinacea include the species and the part of plant used (aerial parts or roots ). In recent years the market for Echinacea has grown rapidly and also the cases of adultery/replacement especially for Echinacea root. The identification of presence or absence of same biomarkers provide information for safe use of Echinacea species in food supplements industry. The aim of the study was the preliminary evaluation and fingerprinting by UV-VISIBLE spectroscopy of biomarkers in terms of content in phenolic derivatives of some Echinacea species (E. purpurea, E. angustifolia and E. pallida) for identification and authentication of the species. The steps of the study were: (1) samples (extracts) preparation from Echinacea species (non-hydrolyzed and hydrolyzed ethanol extracts); (2) samples preparation of reference substances (polyphenol acids: caftaric acid, caffeic acid, chlorogenic acid, ferulic acid; flavonoids: rutoside, hyperoside, isoquercitrin and their aglycones: quercitri, quercetol, luteolin, kaempferol and apigenin); (3) identification of specific absorption at wavelengths between 700-200 nm; (4) identify the phenolic compounds from Echinacea species based on spectral characteristics and the specific absorption; each class of compounds corresponds to a maximum absorption in the UV spectrum. The phytochemical compounds were identified at specific wavelengths between 700-200 nm. The absorption intensities were measured. The obtained results proved that ethanolic extract showed absorption peaks attributed to: phenolic compounds (free phenolic acids and phenolic acids derivatives) registrated between 220-280 nm, unsymmetrical chemical structure compounds (caffeic acid, chlorogenic acid, ferulic acid) with maximum absorption peak and absorption "shoulder" that may be due to substitution of hydroxyl or methoxy group, flavonoid compounds (in free form or glycosides) between 330-360 nm, due to the double bond in position 2,3 and carbonyl group in position 4 flavonols. UV spectra showed two major peaks of absorption (quercetin glycoside, rutin, etc.). The results obtained by UV-VIS spectroscopy has revealed the presence of phenolic derivatives such as cicoric acid (240 nm), caftaric acid (329 nm), caffeic acid (240 nm), rutoside (205 nm), quercetin (255 nm), luteolin (235 nm) in all three species of Echinacea. The echinacoside is absent. This profile mentioned above and the absence of phenolic compound echinacoside leads to the conclusion that species harvested as Echinacea angustifolia and Echinacea pallida are Echinacea purpurea also; It can be said that preliminary fingerprinting of Echinacea species through correspondence with the phenolic derivatives profile can be achieved by UV-VIS spectroscopic investigation, which is an adequate technique for preliminary identification and authentication of Echinacea in medicinal herbs.

Keywords: Echinacea species, Fingerprinting, Phenolic compounds, UV-VIS spectroscopy

Procedia PDF Downloads 228

Authors: Momoka Sunohara, Ashley J. Lemieux, Esther Yakobov, Andrew G. Ryder, Tomas Jurcik

Abstract:

Immigration brings changes in many aspects of an individual's life, from social support dynamics, to housing and language, as well as difficulties with regards to discrimination, trauma, and loss. Past research has mostly emphasized individual differences in mental health and has neglected the impact of social-ecological context, such as acculturation and ethnic density. Purpose: The present study aimed to assess the relationship between variables associated with social integration such as perceived ethnic density and ways of coping, as well as psychological adjustment in a rapidly growing non-visible minority group of immigrants in Canada. Data: A small subset of an archival data from our previously published study was reanalyzed with additional variables. Data included information from 269 Russian-Speaking immigrants in Montreal, Canada. Method: Canonical correlation analysis (CCA) investigated the relationship between two sets of variables. SAS PROC CANCORR was used to conduct CCA on a set of social integration variables, including ethnic density, discrimination, social support, family functioning, and acculturation, and a set of psychological well-being variables, including distress, depression, self-esteem, and life satisfaction. In addition, canonical redundancy analysis was performed to calculate the proportion of variances of original variables explained by their own canonical variates. Results: Significance tests using Rao’s F statistics indicated that the first two canonical correlations (i.e., r1 = 0.64, r2 = 0.40) were statistically significant (p-value < 0.0001). Additionally, canonical redundancy analysis showed that the first two well-being canonical variates explained separately 62.9% and 12.8% variances of the standardized well-being variables, whereas the first two social integration canonical variates explained separately 14.7% and 16.7% variances of the standardized social integration variables. These results support the selection of the first two canonical correlations. Then, we interpreted the derived canonical variates based on their canonical structure (i.e., correlations with original variables). Two observations can be concluded. First, individuals who have adequate social support, and who, as a family, cope by acquiring social support, mobilizing others and reframing are more likely to have better self-esteem, greater life satisfaction and experience less feelings of depression or distress. Second, individuals who feel discriminated yet rate higher on a mainstream acculturation scale, and who, as a family, cope by acquiring social support, mobilizing others and using spirituality, while using less passive strategies are more likely to have better life satisfaction but also higher degree of depression. Implications: This model may serve to explain the complex interactions that exist between social and emotional adjustment and aid in facilitating the integration of individuals immigrating into new communities. The same group may experience greater depression but paradoxically improved life satisfaction associated with their coping process. Such findings need to be placed in the context of Russian cultural values. For instance, some Russian-speakers may value the expression of negative emotions with significant others during the integration process; this in turn may make negative emotions more salient, but also facilitate a greater sense of family and community connection, as well as life satisfaction.

Keywords: acculturation, ethnic density, mental health, Russian-speaking

Procedia PDF Downloads 446

Authors: Aurica P. Chiriac, Vera Balan, Mihai Asandulesa, Elena Butnaru, Nita Tudorachi, Elena Stoleru, Loredana E. Nita, Iordana Neamtu, Alina Diaconu, Liliana Mititelu-Tartau

Abstract:

The interest for studying ‘smart’ materials is entirely justified and in this context were realized investigations on poly(2-hydroxyethylmethacrylate-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane), which is a macromolecular compound with sensibility at pH and temperature, gel formation capacity, binding properties, amphilicity, good oxidative and thermal stability. Physico-chemical characteristics in terms of the molecular weight, temperature-sensitive abilities and thermal stability, as well rheological, dielectric and spectroscopic properties were evaluated in correlation with further coupling capabilities. Differential scanning calorimetry investigation indicated Tg at 36.6 °C and a melting point at Tm=72.8°C, for the studied copolymer, and up to 200oC two exothermic processes (at 99.7°C and 148.8°C) were registered with losing weight of about 4 %, respective 19.27%, which indicate just processes of thermal decomposition (and not phenomena of thermal transition) owing to scission of the functional groups and breakage of the macromolecular chains. At the same time, the rheological studies (rotational tests) confirmed the non-Newtonian shear-thinning fluid behavior of the copolymer solution. The dielectric properties of the copolymer have been evaluated in order to investigate the relaxation processes and two relaxation processes under Tg value were registered and attributed to localized motions of polar groups from side chain macromolecules, or parts of them, without disturbing the main chains. According to literature and confirmed as well by our investigations, β-relaxation is assigned with the rotation of the ester side group and the γ-relaxation corresponds to the rotation of hydroxy- methyl side groups. The fluorescence spectroscopy confirmed the copolymer structure, the spiroacetal moiety getting an axial conformation, more stable, with lower energy, able for specific interactions with molecules from environment, phenomena underlined by different shapes of the emission spectra of the copolymer. Also, the copolymer was used as template for indomethacin incorporation as model drug, and the biocompatible character of the complex was confirmed. The release behavior of the bioactive compound was dependent by the copolymer matrix composition, the increasing of 3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane comonomer amount attenuating the drug release. At the same time, the in vivo studies did not show significant differences of leucocyte formula elements, GOT, GPT and LDH levels, nor immune parameters (OC, PC, and BC) between control mice group and groups treated just with copolymer samples, with or without drug, data attesting the biocompatibility of the polymer samples. The investigation of the physico-chemical characteristics of poly(2-hydrxyethyl methacrylate-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane) in terms of temperature-sensitive abilities, rheological and dielectrical properties, are bringing useful information for further specific use of this polymeric compound.

Keywords: bioapplications, dielectric and spectroscopic properties, dual sensitivity at pH and temperature, smart materials

Procedia PDF Downloads 259

Authors: Etibar Guliyev

Abstract:

The breakdown of the Soviet Union in 1991 has led to a considerable rise in the religious self-consciousness of Muslim population of the Central Asia. Additionally, huge amount of money spent by various states further facilitated the spread of religious ideas. According to some sources, Saudi Arabia spent 87 billion dollars to propagate Wahhabism abroad during two decades, whereas the Communist Party of the Soviet Union spent just over 7 billion dollars to spread its ideology worldwide between 1921 and 1991. As the result, today once a remote area from international politics has turned into third major source of recruitment of fighters for global terrorist organizations. In order to illustrate to scope of the involvement of the Central Asian residents in international terrorist networks it is enough to mention the name of Colonel Gulmorod Khalimov, the former head of the Tajik special police forces who served as ISIS war minister between 2016 and 2017. The importance of the topic stems from the fact that the above-mentioned republics with a territory of 4 million square km and the population of around 80 million people borders Russia, Iran Afghanistan and China. Moreover, the fact that political and military activities motivated with religious feelings in those countries have implications not only for domestic but also for regional and global political relations and all of them has root in politics of religions adds value to the research. This research aims to provide an in-depth analyses of the marked features of the state policies to regulate religious activities and approach this question both from individual, domestic, regional and global levels of analyses. The research will enable us to better understand what implications have the state of religious freedom in post-Soviet Muslim republics for international relations and the rise of global jihadi terrorism. The paper tries to find a linkage between the mentioned terror attacks and underground rise of religious extremism in Central Asia. This research is based on multiple research methods, mainly on qualitative one. The process tracing method is also employed to review religious policies implemented from 1918-1991 and after the collapse of the Soviet Union in a chronological way. In terms of the quantitative method, it chiefly will be used in a bid to process various statistics disseminated in academic and official sources. The research mostly explored constructivist, securitization and social movement theories. Findings of the research suggests that the endemic problems peculiar to authoritarian regimes of Central Asia such as crackdown on the expression of religious believe and any kind of opposition, economic decline, instrumental use of religion and corruption and tribalism further accelerated the recruitment problem. Paper also concludes that the Central Asian states in some cases misused counter-terrorism campaign as a pretext to further restrict freedom of faith in their respective countries.

Keywords: identity, political Islam, religious extremism, security, terrorism

Procedia PDF Downloads 242

Authors: Deepak Loura

Abstract:

Climate change is considered one of the major environmental problems of the 21st century and a lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. Agriculture and climate change are internally correlated with each other in various aspects, as the threat of varying global climate has greatly driven the attention of scientists, as these variations are imparting a negative impact on global crop production and compromising food security worldwide. The fast pace of development and industrialization and indiscriminate destruction of the natural environment, more so in the last century, have altered the concentration of atmospheric gases that lead to global warming. Carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (NO) are important biogenic greenhouse gases (GHGs) from the agricultural sector contributing to global warming and their concentration is increasing alarmingly. Agricultural productivity can be affected by climate change in 2 ways: first, directly, by affecting plant growth development and yield due to changes in rainfall/precipitation and temperature and/or CO₂ levels, and second, indirectly, there may be considerable impact on agricultural land use due to snow melt, availability of irrigation, frequency and intensity of inter- and intra-seasonal droughts and floods, soil organic matter transformations, soil erosion, distribution and frequency of infestation by insect pests, diseases or weeds, the decline in arable areas (due to submergence of coastal lands), and availability of energy. An increase in atmospheric CO₂ promotes the growth and productivity of C3 plants. On the other hand, an increase in temperature, can reduce crop duration, increase crop respiration rates, affect the equilibrium between crops and pests, hasten nutrient mineralization in soils, decrease fertilizer- use efficiencies, and increase evapotranspiration among others. All these could considerably affect crop yield in long run. Climate resilient agriculture consisting of adaptation, mitigation, and other agriculture practices can potentially enhance the capacity of the system to withstand climate-related disturbances by resisting damage and recovering quickly. Climate resilient agriculture turns the climate change threats that have to be tackled into new business opportunities for the sector in different regions and therefore provides a triple win: mitigation, adaptation, and economic growth. Improving the soil organic carbon stock of soil is integral to any strategy towards adapting to and mitigating the abrupt climate change, advancing food security, and improving the environment. Soil carbon sequestration is one of the major mitigation strategies to achieve climate-resilient agriculture. Climate-smart agriculture is the only way to lower the negative impact of climate variations on crop adaptation before it might affect global crop production drastically. To cope with these extreme changes, future development needs to make adjustments in technology, management practices, and legislation. Adaptation and mitigation are twin approaches to bringing resilience to climate change in agriculture.

Keywords: climate change, global warming, crop production, climate resilient agriculture

Procedia PDF Downloads 50

Authors: Jinlu Ruan, Liang Chen, Bo Liu, Xiaoping Ouyang, Zhichao Zhu, Zhongbing Zhang, Shiyi He, Mengxuan Xu

Abstract:

Plastic scintillators play an important role in the measurement of a mixed neutron/gamma pulsed radiation, neutron radiography and pulse shape discrimination technology. In some research, these luminescent properties are necessary that photons produced by the interactions between a plastic scintillator and radiations can be detected as much as possible by the photoelectric detectors and more photons can be emitted from the scintillators along a specific direction where detectors are located. Unfortunately, a majority of these photons produced are trapped in the plastic scintillators due to the total internal reflection (TIR), because there is a significant light-trapping effect when the incident angle of internal scintillation light is larger than the critical angle. Some of these photons trapped in the scintillator may be absorbed by the scintillator itself and the others are emitted from the edges of the scintillator. This makes the light extraction of plastic scintillators very low. Moreover, only a small portion of the photons emitted from the scintillator easily can be detected by detectors effectively, because the distribution of the emission directions of this portion of photons exhibits approximate Lambertian angular profile following a cosine emission law. Therefore, enhancing the light extraction efficiency and adjusting the emission angular profile become the keys for improving the number of photons detected by the detectors. In recent years, photonic crystal structures have been covered on inorganic scintillators to enhance the light extraction efficiency and adjust the angular profile of scintillation light successfully. However, that, preparation methods of photonic crystals will deteriorate performance of plastic scintillators and even destroy the plastic scintillators, makes the investigation on preparation methods of photonic crystals for plastic scintillators and luminescent properties of plastic scintillators with photonic crystal structures inadequate. Although we have successfully made photonic crystal structures covered on the surface of plastic scintillators by a modified self-assembly technique and achieved a great enhance of light extraction efficiency without evident angular-dependence for the angular profile of scintillation light, the preparation of photonic crystal structures with large area (the diameter is larger than 6cm) and perfect periodic structure is still difficult. In this paper, large area photonic crystals on the surface of scintillators were prepared by nanoimprint lithography firstly, and then a conformal layer with material of high refractive index on the surface of photonic crystal by atomic layer deposition technique in order to enhance the stability of photonic crystal structures and increase the number of leaky modes for improving the light extraction efficiency. The luminescent properties of the plastic scintillator with photonic crystals prepared by the mentioned method are compared with those of the plastic scintillator without photonic crystal. The results indicate that the number of photons detected by detectors is increased by the enhanced light extraction efficiency and the angular profile of scintillation light exhibits evident angular-dependence for the scintillator with photonic crystals. The mentioned preparation of photonic crystals is beneficial to scintillation detection applications and lays an important technique foundation for the plastic scintillators to meet special requirements under different application backgrounds.

Keywords: angular profile, atomic layer deposition, light extraction efficiency, plastic scintillator, photonic crystal

Procedia PDF Downloads 168

Authors: Rizwana Tabassum

Abstract:

Introductive Statement: Delay in budget releases is often cited as one of the biggest bottlenecks to smooth and efficient service delivery. While budget release from the ministry of finance to the line ministries has been expedited by simplifying the procedure, budget distribution within the line ministries remains one of the major causes of slow budget utilization. While the budget preparation is a bottom-up process where all DDOs submit their proposals to their controlling officers (such as Upazila Civil Surgeon sends it to Director General Health), who consolidate the budget proposals in iBAS++ budget preparation module, the approved budget is not disaggregated by all DDOs. Instead, it is left to the discretion of the controlling officers to distribute the approved budget to their sub-ordinate offices over the course of the year. Though there are some need-based criteria/formulae to distribute the approved budget among DDOs in some sectors, there is little evidence that these criteria are actually used. This means that majority of the DDOs don’t know their yearly allocations upfront to enable yearly planning of activities and expenditures. This delays the implementation of critical activities and the payment to the suppliers of goods and services and sometimes leads to undocumented arrears to suppliers for essential goods/services. In addition, social sector budgets are fragmented because of the vertical programs and externally financed interventions that pose several management challenges at the level of the budget holders and frontline service providers. Slow procurement processes further delay the provision of necessary goods and services. For example, it takes an average of 15–18 months for drugs to reach the Upazila Health Complex and below, while it should not take more than 9 months in procuring and distributing these. Aim of the Study: This paper aims to investigate the budget distribution practices of an emerging economy, Bangladesh. The paper identifies challenges of timely distribution and ways to deal with problems as well. Methodology: The study draws conclusions on the basis of document analysis which is a branch of the qualitative research method. Major Findings: Upon approval of the National Budget, the Ministry of Finance is required to distribute the budget to budget holders at the department level; however, budget is distributed to drawing and disbursing officers much later. Conclusions: Timely and predictable budget releases assist completion of development schemes on time and on budget, with sufficient recurrent resources for effective operation. ADP implementation is usually very low at the beginning of the fiscal year and expedited dramatically during the last few months, leading to inefficient use of resources. The timely budget release will resolve this issue and deliver economic benefits faster, better, and more reliably. This will also give the project directors/DDOs the freedom to think and plan the budget execution in a predictable manner, thereby ensuring value for money by reducing time overrun and expediting the completion of capital investments, and improving infrastructure utilization through timely payment of recurrent costs.

Keywords: budget distribution, challenges, digitization, emerging economy, service delivery

Procedia PDF Downloads 57

Authors: Carolina Busco, Daniela Osses

Abstract:

The development of digital literacy has become a fundamental element that allows for citizen inclusion, access to quality jobs, and a labor market capable of responding to the digital economy. There are no methodological instruments available in Chile to measure the workforce’s digital literacy and improve national policies on this matter. Thus, the objective of this research is to develop a survey to measure digital literacy in a sample of 200 Chilean workers. Dimensions considered in the instrument are sociodemographics, access to infrastructure, digital education, digital skills, and the ability to use e-government services. To achieve the research objective of developing a digital literacy model of indicators and a research instrument for this purpose, along with an exploratory analysis of data using factor analysis, we used an empirical, quantitative-qualitative, exploratory, non-probabilistic, and cross-sectional research design. The research instrument is a survey created to measure variables that make up the conceptual map prepared from the bibliographic review. Before applying the survey, a pilot test was implemented, resulting in several adjustments to the phrasing of some items. A validation test was also applied using six experts, including their observations on the final instrument. The survey contained 49 items that were further divided into three sets of questions: sociodemographic data; a Likert scale of four values ranked according to the level of agreement; iii) multiple choice questions complementing the dimensions. Data collection occurred between January and March 2022. For the factor analysis, we used the answers to 12 items with the Likert scale. KMO showed a value of 0.626, indicating a medium level of correlation, whereas Bartlett’s test yielded a significance value of less than 0.05 and a Cronbach’s Alpha of 0.618. Taking all factor selection criteria into account, we decided to include and analyze four factors that together explain 53.48% of the accumulated variance. We identified the following factors: i) access to infrastructure and opportunities to develop digital skills at the workplace or educational establishment (15.57%), ii) ability to solve everyday problems using digital tools (14.89%), iii) online tools used to stay connected with others (11.94%), and iv) residential Internet access and speed (11%). Quantitative results were discussed within six focus groups using heterogenic selection criteria related to the most relevant variables identified in the statistical analysis: upper-class school students; middle-class university students; Ph.D. professors; low-income working women, elderly individuals, and a group of rural workers. The digital divide and its social and economic correlations are evident in the results of this research. In Chile, the items that explain the acquisition of digital tools focus on access to infrastructure, which ultimately puts the first filter on the development of digital skills. Therefore, as expressed in the literature review, the advance of these skills is radically different when sociodemographic variables are considered. This increases socioeconomic distances and exclusion criteria, putting those who do not have these skills at a disadvantage and forcing them to seek the assistance of others.

Keywords: digital literacy, digital society, workforce digitalization, digital skills

Procedia PDF Downloads 51

Authors: Natàlia Garcia Soler, Timothy Moss

Abstract:

Despite the multiple benefits of sustainable urban drainage, as demonstrated in numerous case studies across the world, urban rainwater harvesting techniques are generally restricted to isolated model projects. The leap from niche to mainstream has, in most cities, proved an elusive goal. Why policies promoting rainwater harvesting are limited in their widespread implementation has seldom been subjected to systematic analysis. Much of the literature on the policy, planning and institutional contexts of these techniques focus either on their potential benefits or on project design, but very rarely on a critical-constructive analysis of past experiences of implementation. Moreover, the vast majority of these contributions are restricted to single-case studies. There is a dearth of knowledge with respect to, firstly, policy implementation processes and, secondly, multi-case analysis. Insights from both, the authors argue, are essential to inform more effective rainwater harvesting in cities in the future. This paper presents preliminary findings from a research project on rainwater harvesting in cities from a social science perspective that is funded by the Swedish Research Foundation (Formas). This project – UrbanRain – is examining the challenges and opportunities of mainstreaming rainwater harvesting in three European cities. The paper addresses two research questions: firstly, what lessons can be learned on suitable policy incentives and planning instruments for rainwater harvesting from a meta-analysis of the relevant international literature and, secondly, how far these lessons are reflected in a study of past and ongoing rainwater harvesting projects in a European forerunner city. This two-tier approach frames the structure of the paper. We present, first, the results of the literature analysis on policy and planning issues of urban rainwater harvesting. Here, we analyze quantitatively and qualitatively the literature of the past 15 years on this topic in terms of thematic focus, issues addressed and key findings and draw conclusions on research gaps, highlighting the need for more studies on implementation factors, actor interests, institutional adaptation and multi-level governance. In a second step we focus in on the experiences of rainwater harvesting in Berlin and present the results of a mapping exercise on a wide variety of projects implemented there over the last 30 years. Here, we develop a typology to characterize the rainwater harvesting projects in terms of policy issues (what problems and goals are targeted), project design (which kind of solutions are envisaged), project implementation (how and when they were implemented), location (whether they are in new or existing urban developments) and actors (which stakeholders are involved and how), paying particular attention to the shifting institutional framework in Berlin. Mapping and categorizing these projects is based on a combination of document analysis and expert interviews. The paper concludes by synthesizing the findings, identifying how far the goals, governance structures and instruments applied in the Berlin projects studied reflect the findings emerging from the meta-analysis of the international literature on policy and planning issues of rainwater harvesting and what implications these findings have for mainstreaming such techniques in future practice.

Keywords: institutional framework, planning, policy, project implementation, urban rainwater management

Procedia PDF Downloads 264

Authors: Nadia Belu, Laurenţiu Mihai Ionescu, Agnieszka Misztal

Abstract:

The automotive industry is one of the most important industries in the world that concerns not only the economy, but also the world culture. In the present financial and economic context, this field faces new challenges posed by the current crisis, companies must maintain product quality, deliver on time and at a competitive price in order to achieve customer satisfaction. Two of the most recommended techniques of quality management by specific standards of the automotive industry, in the product development, are Failure Mode and Effects Analysis (FMEA) and Control Plan. FMEA is a methodology for risk management and quality improvement aimed at identifying potential causes of failure of products and processes, their quantification by risk assessment, ranking of the problems identified according to their importance, to the determination and implementation of corrective actions related. The companies use Control Plans realized using the results from FMEA to evaluate a process or product for strengths and weaknesses and to prevent problems before they occur. The Control Plans represent written descriptions of the systems used to control and minimize product and process variation. In addition Control Plans specify the process monitoring and control methods (for example Special Controls) used to control Special Characteristics. In this paper we propose a computer-aided solution with Genetic Algorithms in order to reduce the drafting of reports: FMEA analysis and Control Plan required in the manufacture of the product launch and improved knowledge development teams for future projects. The solution allows to the design team to introduce data entry required to FMEA. The actual analysis is performed using Genetic Algorithms to find optimum between RPN risk factor and cost of production. A feature of Genetic Algorithms is that they are used as a means of finding solutions for multi criteria optimization problems. In our case, along with three specific FMEA risk factors is considered and reduce production cost. Analysis tool will generate final reports for all FMEA processes. The data obtained in FMEA reports are automatically integrated with other entered parameters in Control Plan. Implementation of the solution is in the form of an application running in an intranet on two servers: one containing analysis and plan generation engine and the other containing the database where the initial parameters and results are stored. The results can then be used as starting solutions in the synthesis of other projects. The solution was applied to welding processes, laser cutting and bending to manufacture chassis for buses. Advantages of the solution are efficient elaboration of documents in the current project by automatically generating reports FMEA and Control Plan using multiple criteria optimization of production and build a solid knowledge base for future projects. The solution which we propose is a cheap alternative to other solutions on the market using Open Source tools in implementation.

Keywords: automotive industry, FMEA, control plan, automotive technology

Procedia PDF Downloads 383

Authors: Tatjana Kadifkova Panovska, Svetlana Kulevanova, Blagica Jovanova

Abstract:

Biological systems possess the ability to neutralize the excess of reactive oxygen species (ROS) and to protect cells from destructive alterations. However, many pathological conditions (cardiovascular diseases, autoimmune disorders, cancer) are associated with inflammatory processes that generate an excessive amount of reactive oxygen species (ROS) that shift the balance between endogenous antioxidant systems and free oxygen radicals in favor of the latter, leading to oxidative stress. Therefore, an additional source of natural compounds with antioxidant properties that will reduce the amount of ROS in cells is much needed despite their broad utilization; many plant species remain largely unexplored. Therefore, the purpose of the present study is to investigate the antioxidant activity of twenty-five selected medicinal and aromatic plant species. The antioxidant activity of the ethanol extracts was evaluated with in vitro assays: 2,2’-diphenyl-1-pycryl-hydrazyl (DPPH), ferric reducing antioxidant power (FRAP), non-site-specific- (NSSOH) and site-specific hydroxyl radical-2-deoxy-D-ribose degradation (SSOH) assays. The Folin-Ciocalteu method and AlCl3 method were performed to determine total phenolic content (TPC) and total flavonoid content (TFC). All examined plant extracts manifested antioxidant activity to a different extent. Cinnamomum verum J.Presl bark and Ocimum basilicum L. Herba demonstrated strong radical scavenging activity and reducing power with the DPPH and FRAP assay, respectively. Additionally, significant hydroxyl scavenging potential and metal chelating properties were observed using the NSSOH and SSOH assays. Furthermore, significant variations were determined in the total polyphenolic content (TPC) and total flavonoid content (TFC), with Cinnamomum verum and Ocimum basilicum showing the highest amount of total polyphenols. The considerably strong radical scavenging activity, hydroxyl scavenging potential and reducing power for the species mentioned above suggest of a presence of highly bioactive phytochemical compounds, predominantly polyphenols. Since flavonoids are the most abundant group of polyphenols that possess a large number of available reactive OH groups in their structure, it is considered that they are the main contributors to the radical scavenging properties of the examined plant extracts. This observation is supported by the positive correlation between the radical scavenging activity and the total polyphenolic and flavonoid content obtained in the current research. The observations from the current research nominate Cinnamomum verum bark and Ocimum basilicum herba as potential sources of bioactive compounds that could be utilized as antioxidative additives in the food and pharmaceutical industries. Moreover, the present study will help the researchers as basic data for future research in exploiting the hidden potential of these important plants that have not been explored so far.

Keywords: ethanol extracts, radical scavenging activity, reducing power, total polyphenols.

Procedia PDF Downloads 179

Authors: Dan Kanmegne

Abstract:

Africa will become the most populated continent by the end of the century, with around 4 billion inhabitants. Food security and climate changes will become continental issues since agricultural practices depend on climate but also contribute to global emissions and land degradation. Agroforestry has been identified as a cost-efficient and reliable strategy to address these two issues. It is defined as the integrated management of trees and crops/animals in the same land unit. Agroforestry provides benefits in terms of goods (fruits, medicine, wood, etc.) and services (windbreaks, fertility, etc.), and is acknowledged to have a great potential for carbon sequestration; therefore it can be integrated into reduction mechanisms of carbon emissions. Particularly in sub-Saharan Africa, the constraint stands in the lack of information about both areas under agroforestry and the characterization (composition, structure, and management) of each agroforestry system at the country level. This study describes and quantifies “what is where?”, earliest to the quantification of carbon stock in different systems. Remote sensing (RS) is the most efficient approach to map such a dynamic technology as agroforestry since it gives relatively adequate and consistent information over a large area at nearly no cost. RS data fulfill the good practice guidelines of the Intergovernmental Panel On Climate Change (IPCC) that is to be used in carbon estimation. Satellite data are getting more and more accessible, and the archives are growing exponentially. To retrieve useful information to support decision-making out of this large amount of data, satellite data needs to be organized so to ensure fast processing, quick accessibility, and ease of use. A new solution is a data cube, which can be understood as a multi-dimensional stack (space, time, data type) of spatially aligned pixels and used for efficient access and analysis. A data cube for Burkina Faso has been set up from the cooperation project between the international service provider WASCAL and Germany, which provides an accessible exploitation architecture of multi-temporal satellite data. The aim of this study is to map and characterize agroforestry systems using the Burkina Faso earth observation data cube. The approach in its initial stage is based on an unsupervised image classification of a normalized difference vegetation index (NDVI) time series from 2010 to 2018, to stratify the country based on the vegetation. Fifteen strata were identified, and four samples per location were randomly assigned to define the sampling units. For safety reasons, the northern part will not be part of the fieldwork. A total of 52 locations will be visited by the end of the dry season in February-March 2020. The field campaigns will consist of identifying and describing different agroforestry systems and qualitative interviews. A multi-temporal supervised image classification will be done with a random forest algorithm, and the field data will be used for both training the algorithm and accuracy assessment. The expected outputs are (i) map(s) of agroforestry dynamics, (ii) characteristics of different systems (main species, management, area, etc.); (iii) assessment report of Burkina Faso data cube.

Keywords: agroforestry systems, Burkina Faso, earth observation data cube, multi-temporal image classification

Procedia PDF Downloads 116

Authors: T. Ul Rehman, S. Agnello, F. M. Gelardi, M. M. Calvino, G. Lazzara, G. Buscarino, M. Cannas

Abstract:

Metal-Organic Frameworks (MOFs) have emerged as promising candidates for detecting metal ions owing to their large surface area, customizable porosity, and diverse functionalities. In recent years, there has been a surge in research focused on MOFs with luminescent properties. These frameworks are constructed through coordinated bonding between metal ions and multi-dentate ligands, resulting in inherent fluorescent structures. Their luminescent behavior is influenced by factors like structural composition, surface morphology, pore volume, and interactions with target analytes, particularly metal ions. MOFs exhibit various sensing mechanisms, including photo-induced electron transfer (PET) and charge transfer processes such as ligand-to-metal (LMCT) and metal-to-ligand (MLCT) transitions. Among these, MIL-53(Al) stands out due to its flexibility, stability, and specific affinity towards certain metal ions, making it a promising platform for selective metal ion sensing. This study investigates the structural, thermal, and luminescent properties of MIL-53(Al) metal-organic framework (MOF) upon Fe3+ cation exchange. Two separate sets of samples were prepared to activate the MOF powder at different temperatures. The first set of samples, referred to as MIL-53(Al), activated (120°C), was prepared by activating the raw powder in a glass tube at 120°C for 12 hours and then sealing it. The second set of samples, referred to as MIL-53(Al), activated (300°C), was prepared by activating the MIL-53(Al) powder in a glass tube at 300°C for 70 hours. Additionally, 25 mg of MIL-53(Al) powder was dispersed in 5 mL of Fe3+ solution at various concentrations (0.1-100 mM) for the cation exchange experiment. The suspension was centrifuged for five minutes at 10,000 rpm to extract MIL-53(Al) powder. After three rounds of washing with ultrapure water, MIL-53(Al) powder was heated at 120°C for 12 hours. For PXRD and TGA analyses, a sample of the obtained MIL-53(Al) was used. We also activated the cation-exchanged samples for time-resolved photoluminescence (TRPL) measurements at two distinct temperatures (120 and 300°C) for comparative analysis. Powder X-ray diffraction patterns reveal amorphization in samples with higher Fe3+ concentrations, attributed to alterations in coordination environments and ion exchange dynamics. Thermal decomposition analysis shows reduced weight loss in Fe3+-exchanged MOFs, indicating enhanced stability due to stronger metal-ligand bonds and altered decomposition pathways. Raman spectroscopy demonstrates intensity decrease, shape disruption, and frequency shifts, indicative of structural perturbations induced by cation exchange. Photoluminescence spectra exhibit ligand-based emission (π-π* or n-π*) and ligand-to-metal charge transfer (LMCT), influenced by activation temperature and Fe3+ incorporation. Quenching of luminescence intensity and shorter lifetimes upon Fe3+ exchange result from structural distortions and Fe3+ binding to organic linkers. In a nutshell, this research underscores the complex interplay between composition, structure, and properties in MOFs, offering insights into their potential for diverse applications in catalysis, gas storage, and luminescent devices.

Keywords: Fe³⁺ cation exchange, luminescent metal-organic frameworks (LMOFs), MIL-53(Al), solid-state analysis

Procedia PDF Downloads 26

Authors: E. Loffi Borghese

Abstract:

In this comprehensive study, we delve into the intricate dynamics of the big tech oligopoly, focusing particularly on Apple as a case study. The core objective is to scrutinize the evolving relationship between a firm's commitment to positive social impact as its primary purpose and its resilience in the face of disruptive innovations within the big tech market. Our exploration begins with a theoretical framework, emphasizing the significance of distinguishing between corporate social responsibility and social impact as a primary purpose. Drawing on insights from Drumwright and Bartkus and Glassman, we underscore the transformative potential when a firm aligns its core business with a social mission, transcending mere side activities. Examining successful firms, such as Apple, we adopt Sinek's perspective on inspirational leadership and the "golden circle." This framework sheds light on why some organizations, like Apple, succeed in making positive social impact their primary purpose. Apple's early-stage life cycle is dissected, revealing a profound commitment to challenging the status quo and promoting simpler alternatives that resonate with its users' lives. The study then navigates through industry life cycles, drawing on Klepper's stages and Christensen's disruptive innovations. Apple's dominance in the big tech oligopoly is contrasted with companies like Harley Davidson and Polaroid, illustrating the consequences of failing to adapt to disruptive innovations. The data and methods employed encompass a qualitative approach, leveraging sources like ECB, Forbes, World in Data, and scientific articles. A secondary data analysis probes Apple's market evolution within the big tech oligopoly, emphasizing the shifts in market context and innovation trends that demand strategic adaptations. The subsequent sections scrutinize Apple's present innovation strategies, highlighting its diversified product portfolio and intensified focus on big data. We examine the implications of these shifts on Apple's capacity to maintain positive social impact as its primary purpose, pondering potential consequences on its brand perception. The study culminates in a reflection on the broader implications of the big tech oligopoly's dominance. It contemplates the diminishing competitiveness in the market and the potential sidelining of positive social impact as a competitive advantage. The expansion of tech firms into diverse sectors raises concerns about negative societal impacts, prompting a call for increased regulatory attention and awareness. In conclusion, this research serves as a catalyst for heightened awareness and discussion on the intricate interplay between firms' social impact goals, disruptive innovations, and the broader societal implications within the evolving landscape of the big tech oligopoly. Despite limitations, this study aims to stimulate further research, urging a conscious and responsible approach to shaping the future economic system.

Keywords: innovation trends, market dynamics, social impact, tech oligopoly

Procedia PDF Downloads 43

Authors: Pavel Baroch, Jiri Rezek, Michal Prochazka, Tomas Kozak, Jiri Houska

Abstract:

Transparent semiconducting amorphous IGZO films have attracted great attention due to their excellent electrical properties and possible utilization in thin film transistors or in photovoltaic applications as they show 20-50 times higher mobility than that of amorphous silicon. It is also known that the properties of IGZO films are highly sensitive to process parameters, especially to oxygen partial pressure. In this study we have focused on the comparison of properties of transparent semiconducting amorphous indium gallium zinc oxide (IGZO) thin films prepared by conventional sputtering methods and those prepared by high power impulse magnetron sputtering (HiPIMS) method. Furthermore we tried to optimize electrical and optical properties of the IGZO thin films and to investigate possibility to apply these coatings on thermally sensitive flexible substrates. We employed dc, pulsed dc, mid frequency sine wave and HiPIMS power supplies for magnetron deposition. Magnetrons were equipped with sintered ceramic InGaZnO targets. As oxygen vacancies are considered to be the main source of the carriers in IGZO films, it is expected that with the increase of oxygen partial pressure number of oxygen vacancies decreases which results in the increase of film resistivity. Therefore in all experiments we focused on the effect of oxygen partial pressure, discharge power and pulsed power mode on the electrical, optical and mechanical properties of IGZO thin films and also on the thermal load deposited to the substrate. As expected, we have observed a very fast transition between low- and high-resistivity films depending on oxygen partial pressure when deposition using conventional sputtering methods/power supplies have been utilized. Therefore we established and utilized HiPIMS sputtering system for enlargement of operation window for better control of IGZO thin film properties. It is shown that with this system we are able to effectively eliminate steep transition between low and high resistivity films exhibited by DC mode of sputtering and the electrical resistivity can be effectively controlled in the wide resistivity range of 10-² to 10⁵ Ω.cm. The highest mobility of charge carriers (up to 50 cm2/V.s) was obtained at very low oxygen partial pressures. Utilization of HiPIMS also led to significant decrease in thermal load deposited to the substrate which is beneficial for deposition on the thermally sensitive and flexible polymer substrates. Deposition rate as a function of discharge power and oxygen partial pressure was also systematically investigated and the results from optical, electrical and structure analysis will be discussed in detail. Most important result which we have obtained demonstrates almost linear control of IGZO thin films resistivity with increasing of oxygen partial pressure utilizing HiPIMS mode of sputtering and highly transparent films with low resistivity were prepared already at low pO2. It was also found that utilization of HiPIMS technique resulted in significant improvement of surface smoothness in reactive mode of sputtering (with increasing of oxygen partial pressure).

Keywords: charge carrier mobility, HiPIMS, IGZO, resistivity

Procedia PDF Downloads 272

Authors: Jara Kaye S. Villanueva, M. Rosario Concepcion O. Ang

Abstract:

For the past few years, Philippines has depended most of its energy source on oil, coal, and fossil fuel. According to the Department of Energy (DOE), the dominance of coal in the energy mix will continue until the year 2020. The expanding energy needs in the country have led to increasing efforts to promote and develop renewable energy. This research is a part of the government initiative in preparation for renewable energy development and expansion in the country. The Philippine Renewable Energy Resource Mapping from Light Detection and Ranging (LiDAR) Surveys is a three-year government project which aims to assess and quantify the renewable energy potential of the country and to put them into usable maps. This study focuses on the site suitability analysis of the four renewable energy sources – biomass (coconut, corn, rice, and sugarcane), hydro, solar, and wind energy. The site assessment is a key component in determining and assessing the most suitable locations for the construction of renewable energy power plants. This method maximizes the use of both the technical methods in resource assessment, as well as taking into account the environmental, social, and accessibility aspect in identifying potential sites by utilizing and integrating two different methods: the Multi-Criteria Decision Analysis (MCDA) method and Geographic Information System (GIS) tools. For the MCDA, Analytical Hierarchy Processing (AHP) is employed to determine the parameters needed for the suitability analysis. To structure these site suitability parameters, various experts from different fields were consulted – scientists, policy makers, environmentalists, and industrialists. The need to have a well-represented group of people to consult with is relevant to avoid bias in the output parameter of hierarchy levels and weight matrices. AHP pairwise matrix computation is utilized to derive weights per level out of the expert’s gathered feedback. Whereas from the threshold values derived from related literature, international studies, and government laws, the output values were then consulted with energy specialists from the DOE. Geospatial analysis using GIS tools translate this decision support outputs into visual maps. Particularly, this study uses Euclidean distance to compute for the distance values of each parameter, Fuzzy Membership algorithm which normalizes the output from the Euclidean Distance, and the Weighted Overlay tool for the aggregation of the layers. Using the Natural Breaks algorithm, the suitability ratings of each of the map are classified into 5 discrete categories of suitability index: (1) not suitable (2) least suitable, (3) suitable, (4) moderately suitable, and (5) highly suitable. In this method, the classes are grouped based on the best groups similar values wherein each subdivision are set from the rest based on the big difference in boundary values. Results show that in the entire Philippine area of responsibility, biomass has the highest suitability rating with rice as the most suitable at 75.76% suitability percentage, whereas wind has the least suitability percentage with score 10.28%. Solar and Hydro fall in the middle of the two, with suitability values 28.77% and 21.27%.

Keywords: site suitability, biomass energy, hydro energy, solar energy, wind energy, GIS

Procedia PDF Downloads 129

Authors: Zofia Wlodarczyk

Abstract:

I study the experiences of domestic violence survivors who flee their countries of origin in times of political conflict using insight and evidence from forty-five biographical interviews with female Chechen refugees and twelve refugee resettlement professionals in Poland. Both refugees and women are often described as having less agency—that is, they lack the power to decide to migrate – refugees less than economic migrants and women less than men. In this paper, I focus on how female refugees who have been victims of domestic violence make decisions about leaving their countries of origin during times of political conflict. I use several existing migration theories to trace how the migration experience of these women is shaped by dynamics at different levels of society: the macro level, the meso level and the micro level. At the macro level of analysis, I find that political conflict can be both a source of and an escape from domestic violence. Ongoing conflict can strengthen the patriarchal cultural norms, increase violence and constrain women’s choices when it comes to marriage. However, political conflict can also destabilize families and make pathways for women to escape. At the meso level I demonstrate that other political migrants and institutions that emerge due to politically triggered migration can guide those fleeing domestic violence. Finally, at the micro level, I show that family dynamics often force domestic abuse survivors to make their decision to escape alone or with the support of only the most trusted female relatives. Taken together, my analyses show that we cannot look solely at one level of society when describing decision-making processes of women fleeing domestic violence. Conflict-related micro, meso and macro forces interact with and influence each other: on the one hand, strengthening an abusive trap, and on the other hand, opening a door to escape. This study builds upon several theoretical and empirical debates. First, it expands theories of migration by incorporating both refugee and gender perspectives. Few social scientists have used the migration theory framework to discuss the unique circumstances of refugee flows. Those who have mainly focus on “political” migrants, a designation that frequently fails to account for gender, does not incorporate individuals fleeing gender-based violence, including domestic-violence victims. The study also enriches migration scholarship, typically focused on the US and Western-European context, with research from Eastern Europe and Caucasus. Moreover, it contributes to the literature on the changing roles of gender in the context of migration. I argue that understanding how gender roles and hierarchies influence the pre-migration stage of female refugees is crucial, as it may have implications for policy-making efforts in host countries that recognize the asylum claims of those fleeing domestic violence. This study also engages in debates about asylum and refugee law. Domestic violence is normatively and often legally considered an individual-level problem whereas political persecution is recognized as a structural or societal level issue. My study challenges these notions by showing how the migration triggered by domestic violence is closely intertwined with politically motivated refuge.

Keywords: AGENCY, DOMESTIC VIOLENCE, FEMALE REFUGEES, POLITICAL REFUGE, SOCIAL NETWORKS

Procedia PDF Downloads 144

Authors: Matthias Haenisch, Marc Godau, Julia Barreiro, Dominik Maxelon

Abstract:

In times of ubiquitous digitalization and the increasing entanglement of humans and technologies in musical practices in the 21st century, it is to be asked, how popular musicians learn in the (post)digital Age. Against the backdrop of the increasing interest in transferring informal learning practices into formal settings of music education the interdisciplinary research association »MusCoDA – Musical Communities in the (Post)Digital Age« (University of Erfurt/University of Applied Sciences Clara Hoffbauer Potsdam, funded by the German Ministry of Education and Research, pursues the goal to derive an empirical model of collective songwriting practices from the study of informal lelearningf songwriters and bands that can be translated into pedagogical concepts for music education in schools. Drawing on concepts from Community of Musical Practice and Actor Network Theory, lelearnings considered not only as social practice and as participation in online and offline communities, but also as an effect of heterogeneous networks composed of human and non-human actors. Learning is not seen as an individual, cognitive process, but as the formation and transformation of actor networks, i.e., as a practice of assembling and mediating humans and technologies. Based on video stimulated recall interviews and videography of online and offline activities, songwriting practices are followed from the initial idea to different forms of performance and distribution. The data evaluation combines coding and mapping methods of Grounded Theory Methodology and Situational Analysis. This results in network maps in which both the temporality of creative practices and the material and spatial relations of human and technological actors are reconstructed. In addition, positional analyses document the power relations between the participants that structure the learning process of the field. In the area of online informal lelearninginitial key research findings reveal a transformation of the learning subject through the specific technological affordances of TikTok and Instagram and the accompanying changes in the learning practices of the corresponding online communities. Learning is explicitly shaped by the material agency of online tools and features and the social practices entangled with these technologies. Thus, any human online community member can be invited to directly intervene in creative decisions that contribute to the further compositional and structural development of songs. At the same time, participants can provide each other with intimate insights into songwriting processes in progress and have the opportunity to perform together with strangers and idols. Online Lelearnings characterized by an increase in social proximity, distribution of creative agency and informational exchange between participants. While it seems obvious that traditional notions not only of lelearningut also of the learning subject cannot be maintained, the question arises, how exactly the observed informal learning practices and the subject that emerges from the use of social media as online learning technologies can be transferred into contexts of formal learning

Keywords: informal learning, postdigitality, songwriting, actor-network theory, community of musical practice, social media, TikTok, Instagram, apps

Procedia PDF Downloads 102

Authors: Javad Jozaei, Rob G. Bell, Paula Blackett, Scott A. Stephens

Abstract:

In the last few decades, Social Vulnerability Assessment (SVA) has been a favoured means in evaluating the susceptibility of social systems to drivers of change, including climate change and natural disasters. However, the application of SVA to inform responsive and practical strategies to deal with uncertain climate change impacts has always been challenging, and typically agencies resort back to conventional risk/vulnerability assessment. These challenges include complex nature of social vulnerability concepts which influence its applicability, complications in identifying and measuring social vulnerability determinants, the transitory social dynamics in a changing environment, and unpredictability of the scenarios of change that impacts the regime of vulnerability (including contention of when these impacts might emerge). Research suggests that the conventional quantitative approaches in SVA could not appropriately address these problems; hence, the outcomes could potentially be misleading and not fit for addressing the ongoing uncertain rise in risk. The second phase of New Zealand’s Resilience to Nature’s Challenges (RNC2) is developing a forward-looking vulnerability assessment framework and methodology that informs the decision-making and policy development in dealing with the changing coastal systems and accounts for complex dynamics of New Zealand’s coastal systems (including socio-economic, environmental and cultural). Also, RNC2 requires the new methodology to consider plausible drivers of incremental and unknowable changes, create mechanisms to enhance social and community resilience; and fits the New Zealand’s multi-layer governance system. This paper aims to analyse the conventional approaches and methodologies in SVA and offer recommendations for more responsive approaches that inform adaptive decision-making and policy development in practice. The research adopts a qualitative research design to examine different aspects of the conventional SVA processes, and the methods to achieve the research objectives include a systematic review of the literature and case study methods. We found that the conventional quantitative, reductionist and deterministic mindset in the SVA processes -with a focus the impacts of rapid stressors (i.e. tsunamis, floods)- show some deficiencies to account for complex dynamics of social-ecological systems (SES), and the uncertain, long-term impacts of incremental drivers. The paper will focus on addressing the links between resilience and vulnerability; and suggests how resilience theory and its underpinning notions such as the adaptive cycle, panarchy, and system transformability could address these issues, therefore, influence the perception of vulnerability regime and its assessment processes. In this regard, it will be argued that how a shift of paradigm from ‘specific resilience’, which focuses on adaptive capacity associated with the notion of ‘bouncing back’, to ‘general resilience’, which accounts for system transformability, regime shift, ‘bouncing forward’, can deliver more effective strategies in an era characterised by ongoing change and deep uncertainty.

Keywords: complexity, social vulnerability, resilience, transformation, uncertain risks

Procedia PDF Downloads 68

Authors: Chunyang Miao, Bingxin Li, Shanglong Ning, Christopher J. B. Ford

Abstract:

While it is challenging to fabricate electronic devices close to atomic dimensions in conventional top-down lithography, molecular electronics is promising to help maintain the exponential increase in component densities via using molecular building blocks to fabricate electronic components from the bottom up. It offers smaller, faster, and more energy-efficient electronic and photonic systems. A self-assembled monolayer (SAM) of molecules is a layer of molecules that self-assembles on a substrate. They are mechanically flexible, optically transparent, low-cost, and easy to fabricate. A large-area multi-layer structure has been designed and investigated by the team, where a SAM of designed molecules is sandwiched between graphene and gold electrodes. Each molecule can act as a quantum dot, with all molecules conducting in parallel. When a source-drain bias is applied, significant current flows only if a molecular orbital (HOMO or LUMO) lies within the source-drain energy window. If electrons tunnel sequentially on and off the molecule, the charge on the molecule is well-defined and the finite charging energy causes Coulomb blockade of transport until the molecular orbital comes within the energy window. This produces ‘Coulomb diamonds’ in the conductance vs source-drain and gate voltages. For different tunnel barriers at either end of the molecule, it is harder for electrons to tunnel out of the dot than in (or vice versa), resulting in the accumulation of two or more charges and a ‘Coulomb staircase’ in the current vs voltage. This nanostructure exhibits highly reproducible Coulomb-staircase patterns, together with additional oscillations, which are believed to be attributed to molecular vibrations. Molecules are more isolated than semiconductor dots, and so have a discrete phonon spectrum. When tunnelling into or out of a molecule, one or more vibronic states can be excited in the molecule, providing additional transport channels and resulting in additional peaks in the conductance. For useful molecular electronic devices, achieving the optimum orbital alignment of molecules to the Fermi energy in the leads is essential. To explore it, a drop of ionic liquid is employed on top of the graphene to establish an electric field at the graphene, which screens poorly, gating the molecules underneath. Results for various molecules with different alignments of Fermi energy to HOMO have shown highly reproducible Coulomb-diamond patterns, which agree reasonably with DFT calculations. In summary, this large-area SAM molecular junction is a promising candidate for future electronic circuits. (1) The small size (1-10nm) of the molecules and good flexibility of the SAM lead to the scalable assembly of ultra-high densities of functional molecules, with advantages in cost, efficiency, and power dissipation. (2) The contacting technique using graphene enables mass fabrication. (3) Its well-observed Coulomb blockade behaviour, narrow molecular resonances, and well-resolved vibronic states offer good tuneability for various functionalities, such as switches, thermoelectric generators, and memristors, etc.

Keywords: molecular electronics, Coulomb blokade, electron-phonon coupling, self-assembled monolayer

Procedia PDF Downloads 34

Authors: Tsirekidze M., Aprasidze T.

Abstract:

Introduction: The problem of dissocial behavior is at the heart of the social sciences and psychiatry; however, it should be noted that its psychiatric aspect is little studied, and some issues of the problem are still controversial. This is complicated by the diversity of terminological concepts in defining “dissocial behavior”, “behavioral disorder”, “abnormal behavior”, “deviant behavior”, “delinquent behavior”, etc. In literature, there is no comprehensive definition of the essence of dissociative behavior. Numerous attempts to systematize dissociative disorders should also be considered unsatisfactory, which is primarily related to the lack of solid criteria for defining this group of disorders. According to the clinical classification, dissocial behavior is divided into psychotic and non-psychotic forms. Such differentiation is conditional in nature since it is not always possible to draw precise, clear distinctions between these forms, and in addition, there is a transition of a behavior disorder or so-called intermediate forms. One group of authors distinguishes two main forms of deviant behavior in terms of both theoretical and practical significance - non-pathological and pathological. In recent years, especially, the non-pathological form of behavior disorder has become topical. It refers to a large group of forms of deviant behavior, the emergence of which is associated with psychologically full-fledged reactions of children and adolescents to stressful situations and extreme conditions. According to the authors, its concept is understandable-it is difficult to draw a line between psychologically understandable reactions and psychogenically induced reactive states. In addition, the concept of "normal" child and adolescent is, to some extent, a vague concept, as in medicine, any definition of the norm. From a practical (more precisely, pragmatic) point of view, the term "abnormal behavioral disorder" undoubtedly makes sense, especially for the purpose of forensic psychiatric examination. Non-pathological deviation mainly includes transient situational reactions, microsocial-pedagogical backwardness, and character accentuation.Deviant behavior was predominantly manifested in a non-pathological form, which, in our opinion, is due to the difficult socio-economic situation of the country, moral-ethical deprivation, and expressed frustration. By itself, society is an indicator of deviation. Add to this situation complicated factors such as micro-social-pedagogical leave, unfavorable family environment, and parenting defects. Consideration is also given to the connection of acceptable deviation with the personal structural features of the adolescent. Aim: The topic of our discussion is the dissocial behavior of the non-psychotic register. Methods: We surveyed 120 adolescents with deviant behaviors. 61% of them were diagnosed with various neuropsychiatric disorders. Results: Abnormal forms of deviant behavior were observed in 13%, and non-pathological forms in -69%. A combination of non-pathological and pathological forms was present in 10% of cases. In the case of non-pathological deviation, microsocial-pedagogical acceptance was revealed in 62%, character accentuation in 22%; during the pathological forms, pathological reactions were observed in 21%, and abnormal formation of the person -21%. Conclusion: It should be emphasized that in case of any of the above defects, if the so-called family psychosis, and medical and pedagogical habilitation measures for the adolescent, it is quite possible to prevent the abnormal development of the child's personality, correct his character, regulate behavior and develop positive labor-social relations.

Keywords: dissocial personality, deviant behavior, dissocial, delinquent behavior

Procedia PDF Downloads 193

Authors: A. Sottomayor, M. Perez Duque, M. C. Henriques

Abstract:

Introduction: Migration is not a new phenomenon; nomads often traveled, seeking better living conditions, including food and water. The increase of migrations affects all countries, rising health-related challenges. In Portugal, we have had migrant movements in the last decades, pairing with economic behavior. Irregular immigrants are detained in Santo António detention center from Portuguese Immigration and Borders Service (USHA-SEF) in Porto until court decision for a maximum of 60 days. It is the only long stay officially designated detention center for immigrants in Portugal. Immigrant health is important for public health (PH). It affects and is affected by the community. The XXVII Portuguese Government considered immigrant integration, including access to health, health promotion, protection and reduction of inequities a political priority. Many curative, psychological and legal services are provided for detainees, but until 2015, no structured health promotion or prevention actions were being held at USHA-SEF. That year, Porto Occidental PH Local Unit started to provide vaccination and health literacy on this theme for detainees and SEF workers. Our activities include a vaccine lecture, a medical consultation with vaccine prescription and administration, along with documented proof of vaccination. All vaccines are volunteer and free of charge. This action reduces the risk of importation and transmission of diseases, contributing to world eradication and elimination programs. We aimed to characterize the demography of irregular immigrant detained at UHSA-SEF and describe our activity. Methods: All data was provided by Porto Occidental Public Health Unit. All paper registers of vaccination were uploaded to MicrosoftExcel®. We included all registers and collected demographic variables, nationality, vaccination date, category, and administered vaccines. Descriptive analysis was performed using MicrosoftExcel®. Results: From 2015 to 2018, we delivered care to 256 individuals (179 immigrants; 77 workers). Considering immigrants, 72% were male, and 8 (16%) women were pregnant. 85% were between 20-54 years (ᵡ=30,8y; 2-71y), and 11 didn’t report any age. Migrants came from 48 countries, and India had the highest number (9%). MMR and Tetanus vaccines had > 90% vaccination rate and Poliomyelitis, hepatitis B and flu vaccines had around 85% vaccination rates. We had a consistent number of refusals. Conclusion: Our irregular migrant population comes from many different countries, which increases the risk of disease importation. Pregnant women are present as a particular subset of irregular migrants, and vaccination protects them and the baby. Vaccination of migrant is valuable for them and for the countries in which they pass. It contributes to universal health coverage, for eradication programmes and accomplishment of the Sustainable Development Goals. Peer influence may present as a determinant of refusals so we must consistently educate migrants before vaccination. More studies would be valuable, particularly on the migrant trajectory, duration of stay, destiny after court decision and health impact.

Keywords: migrants, public health, universal health coverage, vaccination

Procedia PDF Downloads 92

Authors: Mohanad Elemary, Imose Itua, Rajeswari B. Matam

Abstract:

Virologists and public health experts have been predicting potential pandemics from coronaviruses for decades. The viruses which caused the SARS and MERS pandemics and the Nipah virus led to many lost lives, but still, the COVID-19 pandemic caused by the SARS-CoV2 virus surprised many scientific communities, experts, and governments with its ease of transmission and its pathogenicity. Governments of various countries reacted by locking down entire populations to their homes to combat the devastation caused by the virus, which led to a loss of livelihood and economic hardship to many individuals and organizations. To revive national economies and support their citizens in resuming their lives, governments focused on the development and use of contact tracing apps as a digital way to track and trace exposure. Google and Apple introduced the Exposure Notification Systems (ENS) framework. Independent organizations and countries also developed different frameworks for contact tracing apps. The efficiency, popularity, and adoption rate of these various apps have been different across countries. In this paper, we present a critical analysis of the different contact tracing apps with respect to their efficiency, adoption rate and general perception, and the governmental strategies and policies, which led to the development of the applications. When it comes to the European countries, each of them followed an individualistic approach to the same problem resulting in different realizations of a similarly functioning application with differing results of use and acceptance. The study conducted an extensive review of existing literature, policies, and reports across multiple disciplines, from which a framework was developed and then validated through interviews with six key stakeholders in the field, including founders and executives in digital health startups and corporates as well as experts from international organizations like The World Health Organization. A framework of best practices and tactics is the result of this research. The framework looks at three main questions regarding the contact tracing apps; how to develop them, how to deploy them, and how to regulate them. The findings are based on the best practices applied by governments across multiple countries, the mistakes they made, and the best practices applied in similar situations in the business world. The findings include multiple strategies when it comes to the development milestone regarding establishing frameworks for cooperation with the private sector and how to design the features and user experience of the app for a transparent, effective, and rapidly adaptable app. For the deployment section, several tactics were discussed regarding communication messages, marketing campaigns, persuasive psychology, and the initial deployment scale strategies. The paper also discusses the data privacy dilemma and how to build for a more sustainable system of health-related data processing and utilization. This is done through principles-based regulations specific for health data to allow for its avail for the public good. This framework offers insights into strategies and tactics that could be implemented as protocols for future public health crises and emergencies whether global or regional.

Keywords: contact tracing apps, COVID-19, digital health applications, exposure notification system

Procedia PDF Downloads 113

Authors: Neha Adsul, Rohit Shah

Abstract:

Background: The global history of nursing is exclusively a history of deep contradictions as it seeks to negotiate inclusion in an already gendered world. Although a powerful 'clinical gaze exists, nurses have toiled to re-negotiate and subvert the 'medical gaze' by practicing the 'therapeutic gaze' to tether back 'care into nursing practice.' This helps address the duality of the 'body' and 'mind' wherein the patient is not just limited to being an object of medical inquiry. Nevertheless, there has been a consistent effort to fit 'nursing' into being an art or an emerging science over the years. Especially with advances in hospital-based techno-centric medical practices, the boundaries between technology and nursing practices are becoming more blurred as the technical process becomes synonymous with nursing, eroding the essence of nursing care. Aim: This paper examines the history of nursing and offers insights into how gendered relations and the ideological belief of 'nursing as gendered work' have propagated to the subjugation of the nursing profession. It further aims to provide insights into the patriarchally imbibed techno-centrism that negates the gendered caregiving which lies at the crux of a nurse's work. Method: A literature search was carried out using Google Scholar, Web of Science and PubMed databases. Search words included: technology and nursing, medical technology and nursing, history of nursing, sociology and nursing and nursing care. The history of nursing is presented in a discussion that weaves together the historical events of the 'Birth of the Clinic' and the shift from 'bed-side medicine' to 'hospital-based medicine' that legitimizes exploitation of the bodies of patients to the 'medical gaze while the emergence of nursing as acquiescent to instrumental, technical, positivist and dominant views of medicine. The resultant power asymmetries, wherein in contemporary nursing, the constant struggle of nurses to juggle between being the physicians "operational right arm" to harboring that subjective understanding of the patients to refrain from de-humanizing nursing-care. Findings: The nursing profession suffers from being rendered invisible due to gendered relations having patrifocal societal roots. This perpetuates a notion rooted in the idea that emphasizes empiricism and has resulted in theoretical and epistemological fragmentation of the understanding of body and mind as separate entities. Nurses operate within this structure while constantly being at the brink of being pushed beyond the legitimate professional boundaries while being labeled as being 'unscientific' as the work does not always corroborate and align with the existing dominant positivist lines of inquiries. Conclusion: When understood in this broader context of how nursing as a practice has evolved over the years, it provides a particularly crucial testbed for understanding contemporary gender relations. Not because nurses like to live in a gendered work trap but because the gendered relations at work are written in a covert narcissistic patriarchal milieu that fails to recognize the value of intangible yet utmost necessary 'caring work in nursing. This research urges and calls for preserving and revering the humane aspect of nursing care alongside the emerging tech-savvy expectations from nursing work.

Keywords: nursing history, technocentric, power relations, scientific duality

Procedia PDF Downloads 125

Authors: Trevor C. Brown, David J. Miron

Abstract:

Gas-solid physical adsorption methods are central to the characterization and optimization of the effective surface area, pore size and porosity for applications such as heterogeneous catalysis, and gas separation and storage. Properties such as adsorption uptake, capacity, equilibrium constants and Gibbs free energy are dependent on the composition and structure of both the gas and the adsorbent. However, challenges remain, in accurately calculating these properties from experimental data. Gas adsorption experiments involve measuring the amounts of gas adsorbed over a range of pressures under isothermal conditions. Various constant-parameter models, such as Langmuir and Brunauer-Emmett-Teller (BET) theories are used to provide information on adsorbate and adsorbent properties from the isotherm data. These models typically do not provide accurate interpretations across the full range of pressures and temperatures. The Langmuir adsorption isotherm is a simple approximation for modelling equilibrium adsorption data and has been effective in estimating surface areas and catalytic rate laws, particularly for high surface area solids. The Langmuir isotherm assumes the systematic filling of identical adsorption sites to a monolayer coverage. The BET model is based on the Langmuir isotherm and allows for the formation of multiple layers. These additional layers do not interact with the first layer and the energetics are equal to the adsorbate as a bulk liquid. This BET method is widely used to measure the specific surface area of materials. Both Langmuir and BET models assume that the affinity of the gas for all adsorption sites are identical and so the calculated adsorbent uptake at the monolayer and equilibrium constant are independent of coverage and pressure. Accurate representations of adsorption data have been achieved by extending the Langmuir and BET models to include pressure-varying uptake capacities and equilibrium constants. These parameters are determined using a novel regression technique called flexible least squares for time-varying linear regression. For isothermal adsorption the adsorption parameters are assumed to vary slowly and smoothly with increasing pressure. The flexible least squares for pressure-varying linear regression (FLS-PVLR) approach assumes two distinct types of discrepancy terms, dynamic and measurement for all parameters in the linear equation used to simulate the data. Dynamic terms account for pressure variation in successive parameter vectors, and measurement terms account for differences between observed and theoretically predicted outcomes via linear regression. The resultant pressure-varying parameters are optimized by minimizing both dynamic and measurement residual squared errors. Validation of this methodology has been achieved by simulating adsorption data for n-butane and isobutane on activated carbon at 298 K, 323 K and 348 K and for nitrogen on mesoporous alumina at 77 K with pressure-varying Langmuir and BET adsorption parameters (equilibrium constants and uptake capacities). This modeling provides information on the adsorbent (accessible surface area and micropore volume), adsorbate (molecular areas and volumes) and thermodynamic (Gibbs free energies) variations of the adsorption sites.

Keywords: Langmuir adsorption isotherm, BET adsorption isotherm, pressure-varying adsorption parameters, adsorbate and adsorbent properties and energetics

Procedia PDF Downloads 197

Authors: E. O. Okan, A. Kepic, P. Williams

Abstract:

Iron oxide copper gold (IOCG) deposits constitute important sources of copper and gold in Australia especially since the discovery of the supergiant Olympic Dam deposits in 1975. They are considered to be metasomatic expressions of large crustal-scale alteration events occasioned by intrusive actions and are associated with felsic igneous rocks in most cases, commonly potassic igneous magmatism, with the deposits ranging from ~2.2 –1.5 Ga in age. For the past two decades, geological, geochemical and potential methods have been used to identify the structures hosting these deposits follow up by drilling. Though these methods have largely been successful for shallow targets, at deeper depth due to low resolution they are limited to mapping only very large to gigantic deposits with sufficient contrast. As the search for ore-bodies under regolith cover continues due to depletion of the near surface deposits, there is a compelling need to develop new exploration technology to explore these deep seated ore-bodies within 1-4km which is the current mining depth range. Seismic reflection method represents this new technology as it offers a distinct advantage over all other geophysical techniques because of its great depth of penetration and superior spatial resolution maintained with depth. Further, in many different geological scenarios, it offers a greater ‘3D mapability’ of units within the stratigraphic boundary. Despite these superior attributes, no arguments for crustal scale seismic surveys have been proposed because there has not been a compelling argument of economic benefit to proceed with such work. For the seismic reflection method to be used at these scales (100’s to 1000’s of square km covered) the technical risks or the survey costs have to be reduced. In addition, as most IOCG deposits have large footprint due to its association with intrusions and large fault zones; we hypothesized that these deposits can be found by mainly looking for the seismic signatures of intrusions along prospective structures. In this study, we present two of such cases: - Olympic Dam and Vulcan iron-oxide copper-gold (IOCG) deposits all located in the Gawler craton, South Australia. Results from our 2D modelling experiments revealed that seismic reflection surveys using 20m geophones and 40m shot spacing as an exploration tool for locating IOCG deposit is possible even when hosted in very complex structures. The migrated sections were not only able to identify and trace various layers plus the complex structures but also show reflections around the edges of intrusive packages. The presences of such intrusions were clearly detected from 100m to 1000m depth range without losing its resolution. The modelled seismic images match the available real seismic data and have the hypothesized characteristics; thus, the seismic method seems to be a valid exploration tool to find IOCG deposits. We therefore propose that 2D seismic survey is viable for IOCG exploration as it can detect mineralised intrusive structures along known favourable corridors. This would help in reducing the exploration risk associated with locating undiscovered resources as well as conducting a life-of-mine study which will enable better development decisions at the very beginning.

Keywords: crustal scale, exploration, IOCG deposit, modelling, seismic surveys

Procedia PDF Downloads 305

Authors: Imen Soltani, Takoua Soltani, Taoufik Aguili

Abstract:

Metamaterials crossover classic physical boundaries and gives rise to new phenomena and applications in the domain of beam steering and shaping. Where electromagnetic near and far field manipulations were achieved in an accurate manner. In this sense, 3D imaging is one of the beneficiaries and in particular Denis Gabor’s invention: holography. But, the major difficulty here is the lack of a suitable recording medium. So some enhancements were essential, where the 2D version of bulk metamaterials have been introduced the so-called metasurface. This new class of interfaces simplifies the problem of recording medium with the capability of tuning the phase, amplitude, and polarization at a given frequency. In order to achieve an intelligible wavefront control, the electromagnetic properties of the metasurface should be optimized by means of solving Maxwell’s equations. In this context, integral methods are emerging as an important method to study electromagnetic from microwave to optical frequencies. The method of moment presents an accurate solution to reduce the problem of dimensions by writing its boundary conditions in the form of integral equations. But solving this kind of equations tends to be more complicated and time-consuming as the structural complexity increases. Here, the use of equivalent circuit’s method exhibits the most scalable experience to develop an integral method formulation. In fact, for allaying the resolution of Maxwell’s equations, the method of Generalised Equivalent Circuit was proposed to convey the resolution from the domain of integral equations to the domain of equivalent circuits. In point of fact, this technique consists in creating an electric image of the studied structure using discontinuity plan paradigm and taken into account its environment. So that, the electromagnetic state of the discontinuity plan is described by generalised test functions which are modelled by virtual sources not storing energy. The environmental effects are included by the use of an impedance or admittance operator. Here, we propose a tunable metasurface composed of graphene-based elements which combine the advantages of reflectarrays concept and graphene as a pillar constituent element at Terahertz frequencies. The metasurface’s building block consists of a thin gold film, a dielectric spacer SiO₂ and graphene patch antenna. Our electromagnetic analysis is based on the method of moment combined with generalised equivalent circuit (MoM-GEC). We begin by restricting our attention to study the effects of varying graphene’s chemical potential on the unit cell input impedance. So, it was found that the variation of complex conductivity of graphene allows controlling the phase and amplitude of the reflection coefficient at each element of the array. From the results obtained here, we were able to determine that the phase modulation is realized by adjusting graphene’s complex conductivity. This modulation is a viable solution compared to tunning the phase by varying the antenna length because it offers a full 2π reflection phase control.

Keywords: graphene, method of moment combined with generalised equivalent circuit, reconfigurable metasurface, reflectarray, terahertz domain

Procedia PDF Downloads 152