Search results for: archival work

Authors: Suddhasil Siddhanta, Debasish Nandy

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Child sex ratios pattern in the Asian Population is highly masculine mainly due to birth masculinity and gender bias in child mortality. The vast and the growing literature of female deficit in world population points out the diffusion of child sex ratio pattern in many Asian as well as neighboring European countries. However, little attention has been given to understand the common factors in different demographics in explaining child sex ratio pattern. Such a scholarship is extremely important as level of gender inequity is different in different country set up. Our paper tries to explain the major structural commonalities in the child masculinity pattern in two demographic billionaires - India and China. The analysis reveals that apart from geographical diffusion of sex selection technology, patrilocal social structure, as proxied by households with more than one generation in China and proportion of population aged 65 years and above in India, can explain significant variation of missing girl child in these two countries. Even after controlling for individual capacity building factors like educational attainment, or work force participation, the measure of social stratification is coming out to be the major determinant of child sex ratio variation. Other socio economic factors that perform much well are the agency building factors of the females, like changing pattern of marriage customs which is proxied by divorce and remarriage ratio for china and percentage of female marrying at or after the age of 20 years in India and the female workforce participation. Proportion of minorities in socio-religious composition of the population and gender bias in scholastic attainment in both these counties are also found to be significant in modeling child sex ratio variations. All these significant common factors associated with child sex ratio point toward the one single most important factor: the historical evolution of patriarchy and its contemporary perpetuation in both the countries. It seems that prohibition of sex selection might not be sufficient to combat the peculiar skewness of excessive maleness in child population in both these countries. Demand sided policies is therefore utmost important to root out the gender bias in child sex ratios.

Keywords: child sex ratios, gender bias, structural factors, prosperity, patrilocality

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Authors: Khaled Al-Badani, Andrew Norbury, Essam Elmshawet, Glynn Rotwell, Ian Jenkinson , James Ren

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Micro welding procedures are widely used for joining materials, developing duplex components or functional surfaces, through various methods such as Micro Discharge Welding or Spot Welding process, which can be found in the engineering, aerospace, automotive, biochemical, biomedical and numerous other industries. The relationship between the material properties, structure and processing is very important to improve the structural integrity and the final performance of the welded joints. This includes controlling the shape and the size of the welding nugget, state of the heat affected zone, residual stress, etc. Nowadays, modern high volume productions require the welding of much versatile shapes/sizes and material systems that are suitable for various applications. Hence, an improved understanding of the micro welding process and the digital tools, which are based on computational numerical modelling linking key welding parameters, dimensional attributes and functional performance of the weldment, would directly benefit the industry in developing products that meet current and future market demands. This paper will introduce recent work on developing an integrated experimental and numerical modelling code for micro welding techniques. This includes similar and dissimilar materials for both ferrous and non-ferrous metals, at different scales. The paper will also produce a comparative study, concerning the differences between the micro discharge welding process and the spot welding technique, in regards to the size effect of the welding zone and the changes in the material structure. Numerical modelling method for the micro welding processes and its effects on the material properties, during melting and cooling progression at different scales, will also be presented. Finally, the applications of the integrated numerical modelling and the material development for the digital manufacturing of welding, is discussed with references to typical application cases such as sensors (thermocouples), energy (heat exchanger) and automotive structures (duplex steel structures).

Keywords: computer modelling, droplet formation, material distortion, materials forming, welding

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Authors: Komal Vig, Syamala Soumyakrishnan, Yadav Baral

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Bypass surgery, using the autologous vein has been one of the most effective treatments for cardiovascular diseases (CVD). More recently tissue engineering including engineered vascular grafts to synthesize blood vessels is gaining usage. Dacron and ePTFE has been employed for vascular grafts, however, these does not work well for small diameter grafts (<6 mm) due to intimal hyperplasia and thrombosis. In the present study PTFE was treated with LTP to improve the endothelialization of intimal surface of graft. Scaffolds were also modified with polyvinylpyrrolidone coated silver nanoparticles (Ag-PVP) and the antimicrobial peptides, p753 and p359. Human umbilical vein endothelial cells (HUVEC) were plated on the developed scaffolds and cell proliferation was determined by the MTT assay. Cells attachment on scaffolds was visualized by microscopy. mRNA expressions levels of different cell markers were investigated using quantitative real-time PCR (qPCR). X ray photoelectron spectroscopic confirmed the introduction of oxygenated functionalities from LTP air plasma. Microscopic and MTT assays indicated increase in cell viability in LTP treated scaffolds. Gene expression studies shows enhanced expression of cell adhesion marker Integrin- α 5 gene after LTP treatment. The KB test displayed a zone of inhibition for Ag-PVP, p753 and p359 of 19mm, 14mm, and 12mm respectively. To determine toxicity of antimicrobial agents to cells, MTT Assay was performed using HEK293 cells. MTT Assay exhibited that Ag-PVP and the peptides were non-toxic to cells at 100μg/mL and 50μg/mL, respectively. Live/dead analysis and plate count of treated bacteria exhibited bacterial inhibition on develop scaffold compared to non-treated scaffold. SEM was performed to analyze the structural changes of bacteria after treatment with antimicrobial agents. Gene expression studies were conducted on RNA from bacteria treated with Ag-PVP and peptides using qRT-PCR. Based on our initial results, more scaffolds alternatives will be developed and investigated for cell growth and vascularization studies.

Keywords: low temperature plasma, vascular graft, HUVEC cells, antimicrobial

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Authors: Ouabo Emmanuel Romaric, Amougou Armathe

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Background and aim: The study of impacts of floods and landslides at a small scale, specifically in the urban areas of developing countries is done to provide tools and actors for a better management of risks in such areas, which are now being affected by climate change. The main objective of this study is to assess the hydrometeorological vulnerabilities associated with flooding and urban landslides to propose adaptation measures. Methods: Climatic data analyses were done by calculation of indices of climate change within 50 years (1960-2012). Analyses of field data to determine causes, the level of risk and its consequences on the area of study was carried out using SPSS 18 software. The cartographic analysis and GIS were used to refine the work in space. Then, spatial and terrain analyses were carried out to determine the morphology of field in relation with floods and landslide, and the diffusion on the field. Results: The interannual changes in precipitation has highlighted the surplus years (21), the deficit years (24) and normal years (7). Barakat method bring out evolution of precipitation by jerks and jumps. Floods and landslides are correlated to high precipitation during surplus and normal years. Data field analyses show that populations are conscious (78%) of the risks with 74% of them exposed, but their capacities of adaptation is very low (51%). Floods are the main risk. The soils are classed as feralitic (80%), hydromorphic (15%) and raw mineral (5%). Slope variation (5% to 15%) of small hills and deep valley with anarchic construction favor flood and landslide during heavy precipitation. Mismanagement of waste produce blocks free circulation of river and accentuate floods. Conclusion: Vulnerability of population to hydrometeorological risks in Yaoundé VI is the combination of variation of parameters like precipitation, temperature due to climate change, and the bad planning of construction in urban areas. Because of lack of channels for water to circulate due to saturation of soils, the increase of heavy precipitation and mismanagement of waste, the result are floods and landslides which causes many damages on goods and people.

Keywords: climate change, floods, hydrometeorological, vulnerability

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Authors: Dhouibi Mohamed, Stirbu Bogdan, Chabotier André, Pirlot Marc

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Effects of erosion and wear on the performance of small caliber guns have been analyzed throughout numerical and experimental studies. Mainly, qualitative observations were performed. Correlations between the volume change of the chamber and the maximum pressure are limited. This paper focuses on the development of a numerical model to predict the maximum pressure evolution when the interior shape of the chamber changes in the different weapon’s life phases. To fulfill this goal, an experimental campaign, followed by a numerical simulation study, is carried out. Two test barrels, « 5.56x45mm NATO » and « 7.62x51mm NATO,» are considered. First, a Coordinate Measuring Machine (CMM) with a contact scanning probe is used to measure the interior profile of the barrels after each 300-shots cycle until their worn out. Simultaneously, the EPVAT (Electronic Pressure Velocity and Action Time) method with a special WEIBEL radar are used to measure: (i) the chamber pressure, (ii) the action time, (iii) and the bullet velocity in each barrel. Second, a numerical simulation study is carried out. Thus, a coupled interior ballistic model is developed using the dynamic finite element program LS-DYNA. In this work, two different models are elaborated: (i) coupled Eularien Lagrangian method using fluid-structure interaction (FSI) techniques and a coupled thermo-mechanical finite element using a lumped parameter model (LPM) as a subroutine. Those numerical models are validated and checked through three experimental results, such as (i) the muzzle velocity, (ii) the chamber pressure, and (iii) the surface morphology of fired projectiles. Results show a good agreement between experiments and numerical simulations. Next, a comparison between the two models is conducted. The projectile motions, the dynamic engraving resistances and the maximum pressures are compared and analyzed. Finally, using this obtained database, a statistical correlation between the muzzle velocity, the maximum pressure and the chamber volume is established.

Keywords: engraving process, finite element analysis, gun barrel erosion, interior ballistics, statistical correlation

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Authors: Nikolaos Petropoulos, Elena Blokhina, Andrii Sokolov, Andrii Semenov, Panagiotis Giounanlis, Xutong Wu, Dmytro Mishagli, Eugene Koskin, Robert Bogdan Staszewski, Dirk Leipold

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We investigate entanglement and quantum information scrambling (QIS) by the example of a many-body Extended and spinless effective Fermi-Hubbard Model (EFHM and e-FHM, respectively) that describes a special type of quantum dot array provided by Equal1 labs silicon-based quantum computer. The concept of QIS is used in the framework of quantum information processing by quantum circuits and quantum channels. In general, QIS is manifest as the de-localization of quantum information over the entire quantum system; more compactly, information about the input cannot be obtained by local measurements of the output of the quantum system. In our work, we will first make an introduction to the concept of quantum information scrambling and its connection with the 4-point out-of-time-order (OTO) correlators. In order to have a quantitative measure of QIS we use the tripartite mutual information, in similar lines to previous works, that measures the mutual information between 4 different spacetime partitions of the system and study the Transverse Field Ising (TFI) model; this is used to quantify the dynamical spreading of quantum entanglement and information in the system. Then, we investigate scrambling in the quantum many-body Extended Hubbard Model with external magnetic field Bz and spin-spin coupling J for both uniform and thermal quantum channel inputs and show that it scrambles for specific external tuning parameters (e.g., tunneling amplitudes, on-site potentials, magnetic field). In addition, we compare different Hilbert space sizes (different number of qubits) and show the qualitative and quantitative differences in quantum scrambling as we increase the number of quantum degrees of freedom in the system. Moreover, we find a "scrambling phase transition" for a threshold temperature in the thermal case, that is, the temperature of the model that the channel starts to scramble quantum information. Finally, we make comparisons to the TFI model and highlight the key physical differences between the two systems and mention some future directions of research.

Keywords: condensed matter physics, quantum computing, quantum information theory, quantum physics

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Authors: Mahnaz Seyedoshohadaee, Azadeh Nematolahi, Parsa Rahimi

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Introduction: Rehabilitation training after hip joint surgery is one of the priorities of nursing, which can be helpful in today's world with the advancement of technology. This study was conducted with the aim of the effect of Tele rehabilitation Education on outcomes of hip osteoarthritis. Methods: The present study was a semi-experimental study that was conducted on patients after hip replacement in the first half of 2023. To perform the work, 70 patients who were available were included in the study and were divided into two intervention and control groups by a nonrandom method. Inclusion criteria included: a maximum of 6 months had passed since the hip joint replacement, age between 30-70 years, the ability to follow instructions by the subject, the absence of accompanying orthopedic lesions such as fractures, and having access to the Internet, a smartphone, and the Skype program. Exclusion criteria were severe speech disorder and non-participation in a training session. The research tool included a demographic profile form and Hip disability and osteoarthritis outcome score (HOOS), which were completed by the patients before and after the training. Training for people in the intervention group in 4 sessions, including introduction of the disease, risk factors, symptoms, management of disease symptoms, medication, diet, appropriate exercises and pain relief methods, one session per week for 30 to 45 minutes in the groups 4 to 6 people were offered through Skype software. SPSS version 22 statistical software was used to analyze the data. Results: The average score of osteoarthritis outcomes in the patients before the intervention was 112.74±29.64 in the test group and 110.41±16.34 in the control group, which had no significant difference (P=0.682). After the intervention, it reached 85.25±21.43 and 109.94±15.74, respectively, and this difference was significant (P<0.001). The comparison of the average scores of osteoarthritis results in the test group indicated a significant difference from the pre-test to the post-test time (p<0.001). But in the control group, this difference was not significant (p=0.130). Conclusion: The results showed that Tele rehabilitation Education has a positive effect on reducing the outcomes of hip osteoarthritis, so it is recommended that nurses use Tele rehabilitation Education in their training in order to empower patients.

Keywords: training, rehabilitation, hip osteoarthritides, patient, complications

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Authors: U. Gunal, H. I. Turgut, H. Gurler, S. Kaya

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There are many ever-increasing and newly emerging problems with rapid population growth in the world. With the increase in people's quality of life in our daily life, acoustic comfort has become an important feature in the textile industry. In order to meet all these expectations in people's comfort areas and survive in challenging competitive conditions in the market without compromising the customer product quality expectations of textile manufacturers, it has become a necessity to bring functionality to the products. It is inevitable to research and develop materials and processes that will bring these functionalities to textile products. The noise we encounter almost everywhere in our daily life, in the street, at home and work, is one of the problems which textile industry is working on. It brings with it many health problems, both mentally and physically. Therefore, noise control studies become more of an issue. Besides, materials used in noise control are not sufficient to reduce the effect of the noise level. The fabrics used in acoustic studies in the textile industry do not show sufficient performance according to their weight and high cost. Thus, acoustic textile products can not be used in daily life. In the thesis study, the attributions used in the noise control and building acoustics studies in the literature were analyzed, and the product with the highest damping value that a textile material will have was designed, manufactured, and tested. Optimum values were obtained by using different material samples that may affect the performance of the acoustic material. Acoustic measurement methods should be applied to verify the acoustic performances shown by the parameters and the designed three-dimensional structure at different values. In the measurements made in the study, the device designed for determining the acoustic performance of the material for both the impedance tube according to the relevant standards and the different noise types in the study was used. In addition, sound records of noise types encountered in daily life are taken and applied to the acoustic absorbent fabric with the aid of the device, and the feasibility of the results and the commercial ability of the product are examined. MATLAB numerical computing programming language and libraries were used in the frequency and sound power analyses made in the study.

Keywords: acoustic, egg crate, fabric, textile

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Authors: Sisaynew Tesfaw Admassu

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The strengthening of timber beams can be necessary for several reasons including the increase of live loads (possible in a historical building for a change of destination of use or upgrading to meet new requirements), the reduction of the resistant cross-sections following deterioration (attacks of biological agents such as fungi, and insects) or traumatic events (fires) and the excess of deflection in the members. The main purpose of strengthening an element is not merely to repair it, but also to prevent and minimize the appearance of future problems. This study did an experimental investigation on the behavior of reference and strengthened solid timber beams. The strengthening materials used in this study were CSM-450 glass fiber and steel materials for both flexural and shear strengthening techniques. Twenty-two solid timber beams of Juniperus procera (TID) species with the dimensions of 60 x 90 x 780 mm were used in the present study. The binding material to bond the strengthening materials with timber was general-purpose resin with Luperox® K10 MEKP catalyst. Three beams were used as control beams (unstrengthen beams) while the remaining nineteen beams were strengthened using the strengthening materials for flexure and shear. All the beams were tested for three points loading to failure by using a Universal Testing Machine, UTM-600kN machine. The experimental results showed that the strengthened beams performed better than the unstrengthen beams. The experimental result of flexural strengthened beams showed that the load-bearing capacity of strengthened beams increased between 16.34 – 42.55%. Four layers of Glass Fiber Reinforced polymer on the tension side of the beams was shown to be the most effective way to enhance load-bearing capacity. The strengthened beams also have an enhancement in their flexural stiffness. The stiffness of flexural strengthened beams was increased between 1.18 – 65.53% as compared to the control beams. The highest increment in stiffness has occurred on beams strengthened using 2x60 mm steel plates. The shear-strengthened beams showed a relatively small amount of performance as compared to flexural-strengthened beams; the reason is that the beams are sufficient for shear. The polyester resin used in the experimental work showed good performance in bonding agents between materials. The resin showed more effectiveness in GFRP materials than steel materials.

Keywords: heritage structures, strengthening, stiffness, adhesive, polyester resin, steel plates

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Authors: Catia S. A. Sima, K. Bousson

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Congestion in the Terminal Maneuvering Areas (TMAs) of larger airports impacts all aspects of air traffic flow, not only at national level but may also induce arrival delays at international level. Hence, there is a need to monitor appropriately the air traffic flow in TMAs so that efficient decisions may be taken to manage their occupancy rates. It would be desirable to physically increase the existing airspace to accommodate all existing demands, but this question is entirely utopian and, given this possibility, several studies and analyses have been developed over the past decades to meet the challenges that have arisen due to the dizzying expansion of the aeronautical industry. The main objective of the present paper is to propose concepts to manage and reduce the degree of uncertainty in the air traffic operations, maximizing the interest of all involved, ensuring a balance between demand and supply, and developing and/or adapting resources that enable a rapid and effective adaptation of measures to the current context and the consequent changes perceived in the aeronautical industry. A central task is to emphasize the increase in air traffic flow management capacity to the present day, taking into account not only a wide range of methodologies but also equipment and/or tools already available in the aeronautical industry. The efficient use of these resources is crucial as the human capacity for work is limited and the actors involved in all processes related to air traffic flow management are increasingly overloaded and, as a result, operational safety could be compromised. The methodology used to answer and/or develop the issues listed above is based on the advantages promoted by the application of Markov Chain principles that enable the construction of a simplified model of a dynamic network that describes the air traffic flow behavior anticipating their changes and eventual measures that could better address the impact of increased demand. Through this model, the proposed concepts are shown to have potentials to optimize the air traffic flow management combined with the operation of the existing resources at each moment and the circumstances found in each TMA, using historical data from the air traffic operations and specificities found in the aeronautical industry, namely in the Portuguese context.

Keywords: air traffic flow, terminal maneuvering area, TMA, air traffic management, ATM, Markov chains

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Authors: Manal M. Shehata, Kawther M. Abdel-Hamid, Nashwa A. Mohamed, Marwa H. Bakr, Maged S. Mahmoud, Hala M. Elbadre

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Introduction: The worldwide rapid increase in diabetes poses a significant challenge to current therapeutic approaches. Therapeutic utility of bone marrow transplantation in diabetes is an attractive approach. However, the oxidative stress generated by hyperglycemia may hinder β-cell regeneration. Curcumin, is a dietary spice with antioxidant activity. Aim of work: The present study was undertaken to investigate the therapeutic potential of curcumin, bone marrow transplantation, and their combined effects in the reversal of experimental diabetes. Material and Methods: Fifty adult male healthy albino rats were included in the present study.They were divided into two groups: Group І: (control group) included 10 rats. Group П: (diabetic group): included 40 rats. Diabetes was induced by single intraperitoneal injection of streptozotocin (STZ). Group II will be further subdivided into four groups (10 rats for each): Group II-a (diabetic control). Group II-b: rats were received single intraperitoneal injection of bone marrow suspension (un-fractionated bone marrow cells) prepared from rats of the same family. Group II-c: rats were treated with curcumin orally by gastric intubation for 6 weeks. Group II-d: rats were received a combination of single bone marrow transplantation and curcumin for 6 weeks. After 6 weeks, blood glucose, insulin levels were measured and the pancreas from all rats were processed for Histological, Immunohistochemical and morphometric examination. Results: Diabetic group, showed progressive histological changes in the pancreatic islets. Treatment with either curcumin or bone marrow transplantation improved the structure of the islets and reversed streptozotocin-induced hyperglycemia and hypoinsulinemia. Combination of curcumin and bone marrow transplantation elicited more profound alleviation of streptozotocin-induced changes including islet regeneration and insulin secretion. Conclusion: The use of natural antioxidants combined with bone marrow transplantation to induce pancreatic regeneration is a promising strategy in the management of diabetes.

Keywords: diabtes, panceatic islets, bone marrow transplantation, curcumin

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Authors: Waganesh Zeleke, Abebaw Minaye

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This study examined the act, means, and purpose of human trafficking in the case of Ethiopian migrant returnees from the Middle East and South Africa. Using a questionnaire survey data was gathered from 1078 returnees. Twelve focus group discussions were used to solicit detailed experience of returnee about the process of their 'unsafe' immigration. Both quantitative and qualitative analysis results revealed that against the mainstream thinking of human trafficking means such as forcing, coercing, abducting or threatening, traffickers used 'victims’ free will' means by providing false promises to and capitalizing on the vulnerability of migrants. The migrants’ living condition including unemployment, ambitious view to change their life, and low level of risk perception were found to be risk factors which made them vulnerable and target of the brokers and smugglers who served as a catalyst in the process of their 'unsafe' migration. Equal to the traffickers/brokers/agency, the migrants’ family, friends and Ethiopian embassies contributed to the deplorable situation of migrant workers. 64.4% of the returnees reported that their migration is self-initiated, and 20% reported peer pressure and 13.8 percent reported family pressure, and it is only 1.8% who reported having been pushed by brokers. The findings revealed that 69.5% of the returnees do not know about the lifestyle and culture of the host community before their leave. In a similar vein, 50.9% of the returnees reported that they do not know about the nature of the work they are to do and their responsibilities. Further, 81% of the returnees indicated that the pre-migration training they received was not enough in equipping them with the required skill. Despite the returnees experiences of various forms of abuse and exploitation in the journey and at the destination they still have a positive attitude for migration (t=9.7 mean of 18.85 with a test value of 15). The returnees evaluated the support provided by sending agencies and Ethiopian embassies in the destination to be poor. 51.8% of the migrants do not know the details of the contract they signed during migration. Close to 70% of the returnees expressed that they had not got any legal support from stakeholders when they faced problems. What is more is that despite all these 27.9% of the returnees indicated re-immigrating as their plan. Based on these findings on the context and experience of Ethiopian migrant returnees, implications for training, policy, research, and intervention are discussed.

Keywords: trafficking, migrant, returnee, Ethiopia, experience, reconceptualizing

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Authors: Sophio Kobauri, Tengiz Kantaria, Temur Kantaria, David Tugushi, Nina Kulikova, Ramaz Katsarava

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Nanosized environmentally responsive materials are of special interest for various applications, including targeted drug to a considerable potential for treatment of many human diseases. The important technological advantages of nanoparticles (NPs) usage as drug carriers (nanocontainers) are their high stability, high carrier capacity, feasibility of encapsulation of both hydrophilic or hydrophobic substances, as well as a high variety of possible administration routes, including oral application and inhalation. NPs can also be designed to allow controlled (sustained) drug release from the matrix. These properties of NPs enable improvement of drug bioavailability and might allow drug dosage decrease. The targeted and controlled administration of drugs using NPs might also help to overcome drug resistance, which is one of the major obstacles in the control of epidemics. Various degradable and non-degradable polymers of both natural and synthetic origin have been used for NPs construction. One of the most promising for the design of NPs are amino acid-based biodegradable polymers (AABBPs) which can clear from the body after the fulfillment of their function. The AABBPs are composed of naturally occurring and non-toxic building blocks such as α-amino acids, fatty diols and dicarboxylic acids. The particles designed from these polymers are expected to have an improved bioavailability along with a high biocompatibility. The present work deals with a systematic study of the preparation of NPs by cost-effective polymer deposition/solvent displacement method using AABBPs. The influence of the nature and concentration of surfactants, concentration of organic phase (polymer solution), and the ratio organic phase/inorganic (water) phase, as well as of some other factors on the size of the fabricated NPs have been studied. It was established that depending on the used conditions the NPs size could be tuned within 40-330 nm. As the next step of this research an evaluation of biocompatibility and bioavailability of the synthesized NPs has been performed, using two stable human cell culture lines – HeLa and A549. This part of study is still in progress now.

Keywords: amino acids, biodegradable polymers, nanoparticles (NPs), non-toxic building blocks

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Authors: Periklis Brakatsoulas

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Recent empirical research shows a growing interest in investment decision-making under market anomalies that contradict the rational paradigm. Momentum is undoubtedly one of the most robust anomalies in the empirical asset pricing research and remains surprisingly lucrative ever since first documented. Although predominantly phenomena identified across equities, momentum premia are now evident across various asset classes. Yet few many attempts are made so far to provide traders a diversified portfolio of strategies across different assets and markets. Moreover, literature focuses on patterns from past returns rather than mechanisms to signal future price directions prior to momentum runs. The aim of this paper is to develop a diversified portfolio approach to price distortion signals using daily position data on stocks, credit derivatives, and bonds. An algorithm allocates assets periodically, and new investment tactics take over upon price momentum signals and across different ranking groups. We focus on momentum life cycles, trend reversals, and price acceleration signals. The main effort here concentrates on the density, time span and maturity of momentum phenomena to identify consistent patterns over time and measure the predictive power of buy-sell signals generated by these anomalies. To tackle this, we propose a two-stage modelling process. First, we generate forecasts on core macroeconomic drivers. Secondly, satellite models generate market risk forecasts using the core driver projections generated at the first stage as input. Moreover, using a combination of the ARFIMA and FIGARCH models, we examine the dependence of consecutive observations across time and portfolio assets since long memory behavior in volatilities of one market appears to trigger persistent volatility patterns across other markets. We believe that this is the first work that employs evidence of volatility transmissions among derivatives, equities, and bonds to identify momentum life cycle patterns.

Keywords: forecasting, long memory, momentum, returns

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Authors: Xue Li, Hui Xu

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Mild cognitive impairment (MCI) is a clinical stage that occurs between normal aging and dementia. Although MCI increases the risk of developing dementia, individuals with MCI may maintain stable cognitive function and even recover to a typical cognitive state. An intervention to prevent or delay the progression to dementia in individuals with MCI may involve promoting social engagement. Social participation is the engagement in socially relevant social exchanges and meaningful activities. Older adults with MCI may encounter restricted cognitive abilities, mood changes, and behavioral difficulties during social participation, influencing their willingness to engage. Therefore, this study aims to employ qualitative research methods to gain an in-depth comprehension of the authentic social participation experiences of older adults with mild cognitive impairment, which will establish a foundation for designing appropriate intervention programs. A phenomenological research was conducted. The study participants were selected using the purposive sampling method in combination with the maximum differentiation sampling strategy. Face-to-face semistructured interviews were conducted among 12 elderly individuals suffering from mild cognitive impairment in a community in Zhengzhou City from May to July 2023. Colaizzi 7-step method was used to analyze the data and extract the theme. The real experience of social participation in older adults with mild cognitive impairment can be summarized into 3 themes: (1) a single social relationship but a strong desire to participate, (2) a dual experience of social participation with both positive and negative aspects, (3) multiple barriers to social participation, including impaired memory capacity, heavy family responsibilities and lack of infrastructure. The study found that elderly individuals with mild cognitive impairment and one social interaction display an increased desire to engage in society. To improve social participation levels and reduce cognitive function decline, healthcare providers should work with relevant government agencies and the community to create a comprehensive social participation system. It is important for healthcare providers to note the social participation status of the elderly with mild cognitive impairment.

Keywords: mild cognitive impairment, the elderly, social participation, qualitative research

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Authors: Hana Barak, Alex Sivan, Ariel Kushmaro

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Microorganisms are the most diverse and abundant life forms on Earth and account for a large portion of the Earth’s biomass and biodiversity. To date though, our knowledge regarding microbial life is lacking, as it is based mainly on information from cultivated organisms. Indeed, microbiologists have borrowed from astrophysics and termed the ‘uncultured microbial majority’ as ‘microbial dark matter’. The realization of how diverse and unexplored microorganisms are, actually stems from recent advances in molecular biology, and in particular from novel methods for sequencing microbial small subunit ribosomal RNA genes directly from environmental samples termed next-generation sequencing (NGS). This has led us to use NGS that generates several gigabases of sequencing data in a single experimental run, to identify and classify environmental samples of microorganisms. In metagenomics sequencing analysis (both 16S and shotgun), sequences are compared to reference databases that contain only small part of the existing microorganisms and therefore their taxonomy assignment may reveal groups of unknown microorganisms or origins. These unknowns, or the ‘microbial sequences dark matter’, are usually ignored in spite of their great importance. The goal of this work was to develop an improved bioinformatics method that enables more complete analyses of the microbial communities in numerous environments. Therefore, NGS was used to identify previously unknown microorganisms from three different environments (industrials wastewater, Negev Desert’s rocks and water wells at the Arava valley). 16S rRNA gene metagenome analysis of the microorganisms from those three environments produce about ~4 million reads for 75 samples. Between 0.1-12% of the sequences in each sample were tagged as ‘Unassigned’. Employing relatively simple methodology for resequencing of original gDNA samples through Sanger or MiSeq Illumina with specific primers, this study demonstrates that the mysterious ‘Unassigned’ group apparently contains sequences of candidate phyla. Those unknown sequences can be located on a phylogenetic tree and thus provide a better understanding of the ‘sequences dark matter’ and its role in the research of microbial communities and diversity. Studying this ‘dark matter’ will extend the existing databases and could reveal the hidden potential of the ‘microbial dark matter’.

Keywords: bacteria, bioinformatics, dark matter, Next Generation Sequencing, unknown

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Authors: Surajo Ladan

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There is no doubt nowadays, the media plays a crucial role in the development of languages. Media practitioners influence and set our linguistic norms to a greater extent. Their strategic position makes them influential than school teachers as linguistic pacesetters and models. This is so because of the direct access to the general public that media enjoys being public, oriented and at the same time being patronized by the public, the media is regarded as an authority as far as language use is concerned. In the modern world, listening to the news has become part and parcel of our daily lives. Easy communication has made the world a global village. Contact between countries and people are increasing daily. In Nigeria and indeed the whole of West Africa, radio is the most widely spread out of the three types of media (radio, television, and print). This is because of its (radio) cheapness and less cumbersome and flexibility. Therefore, the positive or negative effect of radio on the lives of a typical Nigerian or African cannot be over emphasized. Hausa language, on the other hand, is one of the most widely spoken languages in West Africa and, of course, the lingua franca in the Northern part of Nigeria and Southern Niger. The language has been in use to a large extent by almost all the popular foreign media houses of BBC, VOA, Deutsche Welle Radio, Radio France International, Radio China, etc. The many people in Nigeria and West Africa depend so much on the news in this language. In fact even government programmes, mobilization, education and sensitization of the populace are done in this language through the broadcast media. It is against this background, for effective and efficient work of this nature it requires the services of a trained translator for the purpose of translating scientific and technological terms. The main thrust of this paper was necessitated for the fact that no nation develops using foreign or borrowed language. This is in lined with UNESCO declaration of 1953 where it says 'the best Language of Instruction (LOI) is the vernacular or the Mother Tongue (MT) of the learner'. This idea is in the right direction especially nowadays that the developing nations have come to terms with realities that their destiny is really in their own hands, not in the hands of the so-called developed nations.

Keywords: translation, scientific, technological, language, radio, media

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Authors: Mengistu Tulu Balcha, Endale Gadisa Motuma

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The purpose of this study was to assess the effect of leadership styles on employees’ organizational commitments in Ambo Woreda public organizations. The study was guided by a Descriptive survey and correlation research design of the quantitative method. By using simple random sampling techniques, 80 participants of employees and by purposive sampling technique, 32 leaders were involved in research from five purposely selected Woreda public organizations without a non-response rate. Two separate instruments adopted from previous studies, namely the multifactor leadership questionnaire (MLQ), which has 36 items and the Organizational Commitment Questionnaire (OCQ), which has 12 items, were used as a data instrument tool. These items were rated by using a five-point Likert-scale. The survey data was processed by using an SPSS (version 27). Descriptive statistics to calculate mean and standard deviations of leaders’ and employees’ responses to leadership styles dominantly practiced in order to determine their perceptions, MLQ of leaders’ and employees’ responses (independent sample), and multiple linear regressions were used to calculate the effect of leadership styles on organizational commitment. The findings of the study show that the leadership style dominantly practiced in Ambo Woreda public organizations was more transactional than transformational and followed by laissez-faire. The level of EOC was ranked as continuance commitment and had the highest mean score, followed by normative commitment and then affective commitment. There is a strong, positive and significant relationship between leadership style dimensions and employees’ organizational commitment. Leadership styles were found statistically significant to predict employee commitment and there was a significant linear relationship between independent variables and dependent variables. Out of the three leadership variables, the transactional leadership style has the highest contribution, followed by the transformational leadership style, whereas the laissez-faire leadership style has the least contribution in predicting employees’ organizational commitment. Finally, the researcher forwarded possible recommendations for Ambo Woreda public organizational leaders and employees to work on improving leadership styles and employees’ commitment collaboratively.

Keywords: organizations, employee, relations, commitments, style

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Authors: Raed KOUTA, José-Alcebiades-Ernesto HLUNGUANE, Eric Châtele

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The search for and exploitation of new fossil energy resources is taking place in the context of the gradual depletion of existing deposits. Despite the adoption of international targets to combat global warming, the demand for fuels continues to grow, contradicting the movement towards an energy-efficient society. The increase in the share of offshore in global hydrocarbon production tends to compensate for the depletion of terrestrial reserves, thus constituting a major challenge for the players in the sector. Through the economic potential it represents, and the energy independence it provides, offshore exploitation is also a challenge for States such as Mozambique, which have large maritime areas and whose environmental wealth must be considered. The exploitation of new reserves on economically viable terms depends on available technologies. The development of deep and ultra-deep offshore requires significant research and development efforts. Progress has also been made in managing the multiple risks inherent in this activity. Our study proposes a reliability approach to develop products and processes designed to live at sea. Indeed, the context of an offshore platform requires highly reliable solutions to overcome the difficulties of access to the system for regular maintenance and quick repairs and which must resist deterioration and degradation processes. One of the characteristics of failures that we consider is the actual conditions of use that are considered 'extreme.' These conditions depend on time and the interactions between the different causes. These are the two factors that give the degradation process its dynamic character, hence the need to develop dynamic reliability models. Our work highlights mathematical models that can explicitly manage interactions between components and process variables. These models are accompanied by numerical resolution methods that help to structure a dynamic reliability approach in a physical and probabilistic context. The application developed makes it possible to evaluate the reliability, availability, and maintainability of a floating storage and unloading platform for liquefied natural gas production.

Keywords: dynamic reliability, offshore plateform, stochastic process, uncertainties

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Authors: Soumya Mishra, Elena Neiterman

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Aligned with the growing interest in the impact of the pandemic on academic experiences of university students, this study aimed to examine the challenges Canadian undergraduate students experienced during the university closures due to COVID-19. Using qualitative methodological approach, the study utilized semi-structured interviews conducted with 20 undergraduate students enrolled in an Ontario university to explore their thoughts and experience regarding online learning during the peak of the COVID-19 pandemic, from January 2021 to March 2021. The interviews yielded four major themes with the following associated subthemes: Personal Challenges Associated with Adapting to the Pandemic (Change in the Type of Stress Experienced, Unique Impact on Certain Groups of Students, Decreased Motivation, Crucial Role of Resilience), Social Challenges Associated with Adapting to the Pandemic (Increased Loneliness, Challenges Faced while Communicating, Perception of Group work, Role of Living Conditions), Challenges associated with Accessing University Resources (Crucial Role of Professors, Perception of Virtual Events, Importance of Physical Spaces). Overall, the analysis showed that the COVID-19 pandemic fostered resilience and psychological flexibility amongst all students. However, the mental health and social wellbeing of students deteriorated during the COVID-19 pandemic and they reported experiencing chronic stress, anxiety and loneliness. International students, first year and final year students experienced a unique set of challenges. It was hard for participants in our study to make strong new connections with their classmates and maintain existing friendships with their peers. The importance of professors in facilitating learning was amplified in the online environment due to the lack of in-person interaction with other students. Despite these challenges, most participants reported that they received high grades during online learning. The findings from this study could be helpful for organizations and individuals working towards fostering the wellbeing of undergraduate students. They can also help in making post-secondary institutions more resilient to future emergencies by creating contingency plans regarding online instructions and risk management techniques.

Keywords: Canadian, COVID-19, university students, wellbeing

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Authors: Sakda Loetpiparwanich, Preecha Vichitthamaros

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Nowadays, poor data quality is considered one of the majority costs for a data project. The data project with data quality awareness almost as much time to data quality processes while data project without data quality awareness negatively impacts financial resources, efficiency, productivity, and credibility. One of the processes that take a long time is defining the expectations and measurements of data quality because the expectation is different up to the purpose of each data project. Especially, big data project that maybe involves with many datasets and stakeholders, that take a long time to discuss and define quality expectations and measurements. Therefore, this study aimed at developing meaningful indicators to describe overall data quality for each dataset to quick comparison and priority. The objectives of this study were to: (1) Develop a practical data quality indicators and measurements, (2) Develop data quality dimensions based on statistical characteristics and (3) Develop Composite Indicator that can describe overall data quality for each dataset. The sample consisted of more than 500 datasets from public sources obtained by random sampling. After datasets were collected, there are five steps to develop the Dataset Quality Index (SDQI). First, we define standard data quality expectations. Second, we find any indicators that can measure directly to data within datasets. Thirdly, each indicator aggregates to dimension using factor analysis. Next, the indicators and dimensions were weighted by an effort for data preparing process and usability. Finally, the dimensions aggregate to Composite Indicator. The results of these analyses showed that: (1) The developed useful indicators and measurements contained ten indicators. (2) the developed data quality dimension based on statistical characteristics, we found that ten indicators can be reduced to 4 dimensions. (3) The developed Composite Indicator, we found that the SDQI can describe overall datasets quality of each dataset and can separate into 3 Level as Good Quality, Acceptable Quality, and Poor Quality. The conclusion, the SDQI provide an overall description of data quality within datasets and meaningful composition. We can use SQDI to assess for all data in the data project, effort estimation, and priority. The SDQI also work well with Agile Method by using SDQI to assessment in the first sprint. After passing the initial evaluation, we can add more specific data quality indicators into the next sprint.

Keywords: data quality, dataset quality, data quality management, composite indicator, factor analysis, principal component analysis

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Authors: Urrutia Fernando, López Jessica, Sánchez Carlos, San Antonio Thalía

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Ecuador, as a signatory country of the convention of the rights of persons with disabilities (CRPD) has, in the recent years, strengthened the structures and legal framework required to protect this minority comprised of 13.2% of its total population. However, the reality is that this group has disproportionately low earnings and low educational attainment in comparison with the general population. The main struggles, to promote job placement of wheelchairs users, are environmental discrimination caused by accessibility in structures and transportation, this mainly due to the cost, for private and public entities, of performing the reasonable accommodation they require. It is widely known that product development and production is needed to support effective implementation of the CRPD and that walking and standing are the major life activities, in this context the objective of this investigation is to promote job placement of wheelchair user in the province of Tungurahua by means of the design, production and marketing of a customized stand up wheelchair. Exploratory interviews and measurements were performed in a representative sample of working age wheelchairs users that develop their disability after achieving their physical maturity and that are capable of performing professional activities with their upper limbs, this in order to detect the user’s preference and determine the local economic and anthropometric parameters to be included in the wheelchair design. The findings reveal factors that uniquely impact quality of life and development for people with a mobility disability within the context of the province, first that transportation is a big issue since public buses does not have accessibility for wheelchair users and the absence of curb cuts and the presence of trash bins over the sidewalks among other hinders an economic independent mobility, second that the proposal based in the idea of modifying the wheelchairs to make it able to overcome certain obstacles helps people in wheelchair to improve their independent living and by reducing the costs of modification for the employer could improve their chances of finding work.

Keywords: anthropometrics, job placement, stand up wheelchair, user centered design

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Authors: Prasad Pokkunuri

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Visco-elastic materials combine the stress response properties of both solids and fluids and have found use in a variety of damping applications – both vibrational and acoustic. Defense and automotive applications, in particular, are subject to high impact and shock loading – for example: aircraft landing gear, firearms, and shock absorbers. Field responsive fluids – a class of smart materials – are the preferred choice of energy absorbents because of their controllability. These fluids’ stress response can be controlled by the application of a magnetic or electric field, in a closed loop. Their rheological properties – elasticity, plasticity, and viscosity – can be varied all the way from that of a liquid such as water to a hard solid. This work presents a simplified model to study the impulse response behavior of such fluids for use in recoil damping systems. The well-known Burger’s equation, in conjunction with various visco-elastic constitutive models, is used to represent fluid behavior. The Kelvin-Voigt, Upper Convected Maxwell (UCM), and Oldroyd-B constitutive models are implemented in this study. Using these models in a one-dimensional framework eliminates additional complexities due to geometry, pressure, body forces, and other source terms. Using a finite difference formulation to numerically solve the governing equation(s), the response to an initial impulse is studied. The disturbance is confined within the problem domain with no-inflow, no-outflow boundary conditions, and its decay characteristics studied. Visco-elastic fluids typically involve a time-dependent stress relaxation which gives rise to interesting behavior when subjected to an impulsive load. For particular values of viscous damping and elastic modulus, the fluid settles into a stable oscillatory state, absorbing and releasing energy without much decay. The simplified formulation enables a comprehensive study of different modes of system response, by varying relevant parameters. Using the insights gained from this study, extension to a more detailed multi-dimensional model is considered.

Keywords: Burgers Equation, Impulse Response, Recoil Damping Systems, Visco-elastic Fluids

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Authors: Nidhi Gupta, Omita Nanda, Rakhi Grover, Kanchan Saxena

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Hybrid perovskite is new class of material which has gained much attention due to their different crystal structure and interesting optical and electrical properties. Easy fabrication, high absorption coefficient, and photoluminescence properties make them a strong candidate for various applications such as sensors, photovoltaics, photodetectors, etc. In perovskites, ions arrange themselves in a special type of crystal structure with chemical formula ABX3, where A is organic species like CH3NH3+, B is metal ion (e.g., Pb, Sn, etc.) and X is halide (Cl-, Br-, I-). In crystal structure, A is present at corner position, B at center of the crystal lattice and halide ions at the face centers. High stability and sensitivity of nanostructured perovskite make them suitable for chemical sensors. Researchers have studied sensing properties of perovskites for number of analytes such as 2,4,6-trinitrophenol, ethanol and other hazardous chemical compounds. Ammonia being highly toxic agent makes it a reason of concern for the environment. Thus the detection of ammonia is extremely important. Our present investigation deals with organic inorganic hybrid perovskite based ammonia sensor. Various methods like sol-gel, solid state synthesis, thermal vapor deposition etc can be used to synthesize Different hybrid perovskites. In the present work, a novel hybrid perovskite has been synthesized by a single step method. Ethylenediammnedihalide and lead halide were used as precursor. Formation of hybrid perovskite was confirmed by FT-IR and XRD. Morphological characterization of the synthesized material was performed using scanning electron microscopy (SEM). SEM analysis revealed the formation of one dimensional nanowire perovskite with mean diameter of 200 nm. Measurements for sensing properties of halide perovskite for ammonia vapor were carried out. Perovskite thin films showed a color change from yellow to orange on exposure of ammonia vapor. Electro-optical measurements show that sensor based on lead halide perovskite has high sensitivity towards ammonia with effective selectivity and reversibility. Sensor exhibited rapid response time of less than 20 seconds.

Keywords: hybrid perovskite, ammonia, sensor, nanostructure, thin film

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Authors: Filip Rusak, Yulia Arzhaeva, Dadong Wang

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Machine learning based Computer-Aided Diagnosis (CAD) is gaining much popularity in medical imaging and diagnostic radiology. However, it requires a large amount of high quality and labeled training image datasets. The training images may come from different sources and be acquired from different radiography machines produced by different manufacturers, digital or digitized copies of film radiographs, with various sizes as well as different pixel intensity distributions. In this paper, a content-aware image augmentation method is presented to deal with these variations. The results of the proposed method have been validated graphically by plotting the removed and added seams of pixels on original images. Two different chest X-ray (CXR) datasets are used in the experiments. The CXRs in the datasets defer in size, some are digital CXRs while the others are digitized from analog CXR films. With the proposed content-aware augmentation method, the Seam Carving algorithm is employed to resize CXRs and the corresponding labels in the form of image masks, followed by histogram matching used to normalize the pixel intensities of digital radiography, based on the pixel intensity values of digitized radiographs. We implemented the algorithms, resized the well-known Montgomery dataset, to the size of the most frequently used Japanese Society of Radiological Technology (JSRT) dataset and normalized our digital CXRs for testing. This work resulted in the unified off-the-shelf CXR dataset composed of radiographs included in both, Montgomery and JSRT datasets. The experimental results show that even though the amount of augmentation is large, our algorithm can preserve the important information in lung fields, local structures, and global visual effect adequately. The proposed method can be used to augment training and testing image data sets so that the trained machine learning model can be used to process CXRs from various sources, and it can be potentially used broadly in any medical imaging applications.

Keywords: computer-aided diagnosis, image augmentation, lung segmentation, medical imaging, seam carving

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Authors: David Holton, Michelle Dickinson, Giovanni Carta

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The principle of geological disposal is to isolate higher-activity radioactive wastes deep inside a suitable rock formation to ensure that no harmful quantities of radioactivity reach the surface environment. To achieve this, wastes will be placed in an engineered underground containment facility – the geological disposal facility (GDF) – which will be designed so that natural and man-made barriers work together to minimise the escape of radioactivity. Internationally, various multi-barrier concepts have been developed for the disposal of higher-activity radioactive wastes. High-heat-generating wastes (HLW, spent fuel and Pu) provide a number of different technical challenges to those associated with the disposal of low-heat-generating waste. Thermal management of the disposal system must be taken into consideration in GDF design; temperature constraints might apply to the wasteform, container, buffer and host rock. Of these, the temperature limit placed on the buffer component of the engineered barrier system (EBS) can be the most constraining factor. The heat must therefore be managed such that the properties of the buffer are not compromised to the extent that it cannot deliver the required level of safety. The maximum temperature of a buffer surrounding a container at the centre of a fixed array of heat-generating sources, arises due to heat diffusing from neighbouring heat-generating wastes, incrementally contributing to the temperature of the EBS. A range of strategies can be employed for managing heat in a GDF, including the spatial arrangements or patterns of those containers; different geometrical configurations can influence the overall thermal density in a disposal facility (or area within a facility) and therefore the maximum buffer temperature. A semi-analytical thermal dimensioning tool and methodology have been applied at a generic stage to explore a range of strategies to manage the disposal of high-heat-generating waste. A number of examples, including different geometrical layouts and chequer-boarding, have been illustrated to demonstrate how these tools can be used to consider safety margins and inform strategic disposal options when faced with uncertainty, at a generic stage of the development of a GDF.

Keywords: buffer, geological disposal facility, high-heat-generating waste, spent fuel

Procedia PDF Downloads 285

Authors: Tânia F. C. V. Silva, Eloísa S. S. Vieira, João Pinto da Costa, Rui A. R. Boaventura, Vitor J. P. Vilar

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Sanitary landfill leachates are characterized as a complex mixture of diverse organic and inorganic contaminants, which are usually removed by combining different treatment processes. Due to its simplicity, reliability, high cost-effectiveness and high nitrogen content (mostly under the ammonium form) inherent in this type of effluent, the activated sludge biological process is almost always applied in leachate treatment plants (LTPs). The purpose of this work is to assess the effect of the main nitrification and denitrification variables on the nitrogen's biological removal, from mature leachates. The leachate samples were collected after an aerated lagoon, at a LTP nearby Porto, presenting a high amount of dissolved organic carbon (1.0-1.3 g DOC/L) and ammonium nitrogen (1.1-1.7 g NH4+-N/L). The experiments were carried out in a 1-L lab-scale batch reactor, equipped with a pH, temperature and dissolved oxygen (DO) control system, in order to determine the reaction kinetic constants at unchanging conditions. The nitrification reaction rate was evaluated while varying the (i) operating temperature (15, 20, 25 and 30ºC), (ii) DO concentration interval (0.5-1.0, 1.0-2.0 and 2.0-4.0 mg/L) and (iii) solution pH (not controlled, 7.5-8.5 and 6.5-7.5). At the beginning of most assays, it was verified that the ammonium stripping occurred simultaneously to the nitrification, reaching up to 37% removal of total dissolved nitrogen. The denitrification kinetic constants and the methanol consumptions were calculated for different values of (i) volatile suspended solids (VSS) content (25, 50 and 100 mL of centrifuged sludge in 1 L solution), (ii) pH interval (6.5-7.0, 7.5-8.0 and 8.5-9.0) and (iii) temperature (15, 20, 25 and 30ºC), using effluent previously nitrified. The maximum nitrification rate obtained was 38±2 mg NH4+-N/h/g VSS (25ºC, 0.5-1.0 mg O2/L, pH not controlled), consuming 4.4±0.3 mg CaCO3/mg NH4+-N. The highest denitrification rate achieved was 19±1 mg (NO2--N+NO3--N)/h/g VSS (30ºC, 50 mL of sludge and pH between 7.5 and 8.0), with a C/N consumption ratio of 1.1±0.1 mg CH3OH/mg (NO2--N+NO3--N) and an overall alkalinity production of 3.7±0.3 mg CaCO3/mg (NO2--N+NO3--N). The denitrification process showed to be sensitive to all studied parameters, while the nitrification reaction did not suffered significant change when DO content was changed.

Keywords: mature sanitary landfill leachate, nitrogen removal, nitrification and denitrification parameters, lab-scale activated sludge biological reactor

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Authors: Dileep Maarisetty, Janaki Komandur, Saroj S. Baral

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In the current work, photocatalytic degradation of phenol was carried both in UV and visible light to find the slowest step that is limiting the rate of photo-degradation process. Characterization such as XRD, SEM, FT-IR, TEM, XPS, UV-DRS, PL, BET, UPS, ESR and zeta potential experiments were conducted to assess the credibility of catalysts in boosting the photocatalytic activity. To explore the synergy, TiO₂ was doped with graphene and alumina. The orbital hybridization with alumina doping (mediated by graphene) resulted in higher electron transfer from the conduction band of TiO₂ to alumina surface where oxygen reduction reactions (ORR) occur. Besides, the doping of alumina and graphene introduced defects into Ti lattice and helped in improving the adsorptive properties of modified photo-catalyst. Results showed that these defects promoted the oxygen reduction reactions (ORR) on the catalyst’s surface. ORR activity aims at producing reactive oxygen species (ROS). These ROS species oxidizes the phenol molecules which is adsorbed on the surface of photo-catalysts, thereby driving the photocatalytic reactions. Since mass transfer is considered as rate limiting step, various mathematical models were applied to the experimental data to probe the best fit. By varying the parameters, it was found that intra-particle diffusion was the slowest step in the degradation process. Lagergren model gave the best R² values indicating the nature of rate kinetics. Similarly, different adsorption isotherms were employed and realized that Langmuir isotherm suits the best with tremendous increase in uptake capacity (mg/g) of TiO₂-rGO-Al₂O₃ as compared undoped TiO₂. This further assisted in higher adsorption of phenol molecules. The results obtained from experimental, kinetic modelling and adsorption isotherms; it is concluded that apart from changes in surface, optoelectronic and morphological properties that enhanced the photocatalytic activity, the intra-particle diffusion within the catalyst’s pores serve as rate-limiting step in deciding the fate of photo-catalytic degradation of phenol.

Keywords: ORR, phenol degradation, photo-catalyst, rate kinetics

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Authors: Rebecca M. Dagger, Katy Hadgraft, Matthew Teggart, Peter Angell

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Background: There is a growing body of evidence that demonstrates the association between sedentary behaviour, cardiometabolic risk and all-cause mortality. Since full time working adults spend approximately 8 hours per day in the workplace, interventions to reduce sedentary behaviour at work may alleviate some of the negative health outcomes associated with sedentary behaviour. The aims of this pilot study were to assess the impacts of using a Sit-Stand workstation on markers of cardiometabolic health in a cohort of desk workers. Methods: Twenty eight participants were recruited and randomly assigned to a control (n=5 males, 9 females, mean age 37 years ± 9.4 years) or intervention group (n= 5 males, 9 females, mean age 42 years ± 12.7 years). All participants attended the labs on 2 occasion’s pre and post intervention, following baseline measurements the intervention participants had the Sit Stand Workstations (Ergotron, USA) installed for a 10 week intervention period. The Sit Stand workstations allow participants to stand or sit at their usual workstation and participants were encouraged to the use the desk in a standing position at regular intervals throughout the working day. Cardiometabolic risk markers assessed were body mass, body composition (using bio impedance analysis; Tanita, Tokyo), fasting blood Total Cholesterol (TC), lipid profiles (HDL-C, LDL-C, TC: HDL-C ratio), triglycerides and fasting glucose (Cholestech LDX), resting systolic and diastolic blood pressure and resting heart rate. ANCOVA controlling for baseline values was used to assess the group difference in changes in risk markers between pre and post intervention. Results: The 10 week intervention was associated with significant reductions in some cardiometabolic risk factors. There were significant group effects on change in body mass (F (1,25)=5.915, p<0.05), total body fat percentage (F(1,25)=12.615, p<0.01), total fat mass (F (1,25)=6.954, p<0.05), and systolic blood pressure (F (1,25)=5.012, p<0.05). There were no other significant group effects on changes in other cardiometabolic risk markers. Conclusion: This pilot study highlights the importance of reducing sedentary behaviour in the workplace for reduction in cardiometabolic risk markers. Further research is required to support these findings.

Keywords: sedentary behaviour, caridometabolic risk, evidence, risk makers

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Authors: Siobhan Hegarty, Michael Bloomfield, Kim Entholt, Dorothy Williams, Helen Kennerley

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Complex Post-Traumatic Stress Disorder (CPTSD) confers greater risk of poor outcomes than does Post-Traumatic Stress Disorder (PTSD). Despite this, the current treatment guidelines for CPTSD aim to reduce only the ‘core’ symptoms of re-experiencing, hyper-vigilance and avoidance, while not addressing the Disturbances of Self Organisation (DSO) symptoms that distinguish this novel diagnosis from PTSD. The Recovering from Child Abuse Programme (RCAP) is a group protocol, based on the principles of cognitive behavioural therapy (CBT). Preliminary evidence suggests the program is effective at reducing DSO symptoms. This pilot study is the first to investigate the potential effectiveness of the RCAP for the specific treatment of CPTSD. This study was conducted as a service evaluation in a secondary care, traumatic stress service. Treatment was delivered once a week, in two-hour sessions, to ten existing female CPTSD patients of the service, who had experienced sexual abuse in childhood. The programme was administered by two therapists and two additional facilitators, following the RCAP protocol manual. Symptom severity was measured before the administration of therapy and was tracked across a range of measures (International Trauma Questionnaire; Patient Health Questionnaire; Community Assessment of Psychic Experience; Work and Social Adjustment Scale) at five time points, over the course of treatment. Qualitative appraisal of the programme was gathered via weekly feedback forms and from audio-taped recordings of verbal feedback given during group sessions. Preliminary results suggest the programme causes a slight reduction in CPTSD and depressive symptom severity and preliminary qualitative analysis suggests that the RCAP is both helpful and acceptable to group members. Final results and conclusions will follow completed thematic analysis of results.

Keywords: Child sexual abuse, Cognitive behavioural therapy, Complex post-traumatic stress disorder, Recovering from child abuse programme

Procedia PDF Downloads 135