Search results for: Region of Interest (ROI)
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 8186

Search results for: Region of Interest (ROI)

686 A Multilingual App for Studying Children’s Developing Values: Developing a New Arabic Translation of the Picture-based Values Survey and Comparison of Palestinian and Jewish Children in Israel

Authors: Aysheh Maslamani, Ella Daniel, Anna Dӧring, Iyas Nasser, Ariel Knafo-Noam

Abstract:

Over 250 million people globally speak Arabic, one of the most widespread languages in the world, as their first language. Yet only a minuscule fraction of developmental research studies Middle East children. As values are a core component of culture, understanding how values develop is key to understanding development across cultures. Indeed, with the advent of research on value development, significantly since the introduction of the Picture-Based Value Survey for Children, interest in cross-cultural differences in children's values is increasing. As no measure exists for Arab children, PBVS-C in Arabic developed. The online application version of the PBVS-C that can be administered on a computer, tablet, or even a smartphone to measure the 10 values whose presence has been repeatedly demonstrated across the world. The application has been developed simultaneously in Hebrew and Arabic and can easily be adapted to include additional languages. In this research, the development of the multilingual PBVS-C application version adapted for five-year-olds. The translation process discussed (including important decisions such as which dialect of Arabic, a diglossic language, is most suitable), adaptations to subgroups (e.g., Muslim, Druze and Christian Arab children), and using recorded instructions and value item captions, as well as touchscreens to enhance applicability with young children. Four hundred Palestinian and Israeli 5-12 year old children reported their values using the app (50% in Arabic, 50% in Hebrew). Confirmatory Multidimensional Scaling (MDS) analyses revealed structural patterns that closely correspond to Schwartz's theoretical structure in both languages (e.g., universalism values correlated positively with benevolence and negatively with power, whereas tradition correlated negatively with hedonism and positively with conformity). Replicating past findings, power values showed lower importance than benevolence values in both cultural groups, and there were gender differences in which girls were higher in self-transcendence values and lower in self-enhancement values than boys. Cultural value importance differences were explored and revealed that Palestinian children are significantly higher in tradition and achievement values compared to Israeli children, whereas Israeli children are significantly higher in benevolence, hedonism, self-direction, and stimulation values. Age differences in value coherence across the two groups were also studied. Exploring the cultural differences opens a window to understanding the basic motivations driving populations that were hardly studied before. This study will contribute to the developmental value research since it considers the role of critical variables such as culture and religion and tests value coherence across middle childhood. Findings will be discussed, and the potential and limitations of the computerized PBVS-C concerning future values research.

Keywords: Arab-children, culture, multilingual-application, value-development

Procedia PDF Downloads 72
685 Coastal Resources Spatial Planning and Potential Oil Risk Analysis: Case Study of Misratah’s Coastal Resources, Libya

Authors: Abduladim Maitieg, Kevin Lynch, Mark Johnson

Abstract:

The goal of the Libyan Environmental General Authority (EGA) and National Oil Corporation (Department of Health, Safety & Environment) during the last 5 years has been to adopt a common approach to coastal and marine spatial planning. Protection and planning of the coastal zone is a significant for Libya, due to the length of coast and, the high rate of oil export, and spills’ potential negative impacts on coastal and marine habitats. Coastal resource scenarios constitute an important tool for exploring the long-term and short-term consequences of oil spill impact and available response options that would provide an integrated perspective on mitigation. To investigate that, this paper reviews the Misratah coastal parameters to present the physical and human controls and attributes of coastal habitats as the first step in understanding how they may be damaged by an oil spill. This paper also investigates costal resources, providing a better understanding of the resources and factors that impact the integrity of the ecosystem. Therefore, the study described the potential spatial distribution of oil spill risk and the coastal resources value, and also created spatial maps of coastal resources and their vulnerability to oil spills along the coast. This study proposes an analysis of coastal resources condition at a local level in the Misratah region of the Mediterranean Sea, considering the implementation of coastal and marine spatial planning over time as an indication of the will to manage urban development. Oil spill contamination analysis and their impact on the coastal resources depend on (1) oil spill sequence, (2) oil spill location, (3) oil spill movement near the coastal area. The resulting maps show natural, socio-economic activity, environmental resources along of the coast, and oil spill location. Moreover, the study provides significant geodatabase information which is required for coastal sensitivity index mapping and coastal management studies. The outcome of study provides the information necessary to set an Environmental Sensitivity Index (ESI) for the Misratah shoreline, which can be used for management of coastal resources and setting boundaries for each coastal sensitivity sectors, as well as to help planners measure the impact of oil spills on coastal resources. Geographic Information System (GIS) tools were used in order to store and illustrate the spatial convergence of existing socio-economic activities such as fishing, tourism, and the salt industry, and ecosystem components such as sea turtle nesting area, Sabkha habitats, and migratory birds feeding sites. These geodatabases help planners investigate the vulnerability of coastal resources to an oil spill.

Keywords: coastal and marine spatial planning advancement training, GIS mapping, human uses, ecosystem components, Misratah coast, Libyan, oil spill

Procedia PDF Downloads 347
684 Reservoir-Triggered Seismicity of Water Level Variation in the Lake Aswan

Authors: Abdel-Monem Sayed Mohamed

Abstract:

Lake Aswan is one of the largest man-made reservoirs in the world. The reservoir began to fill in 1964 and the level rose gradually, with annual irrigation cycles, until it reached a maximum water level of 181.5 m in November 1999, with a capacity of 160 km3. The filling of such large reservoir changes the stress system either through increasing vertical compressional stress by loading and/or increased pore pressure through the decrease of the effective normal stress. The resulted effect on fault zones changes stability depending strongly on the orientation of pre-existing stress and geometry of the reservoir/fault system. The main earthquake occurred on November 14, 1981, with magnitude 5.5. This event occurred after 17 years of the reservoir began to fill, along the active part of the Kalabsha fault and located not far from the High Dam. Numerous of small earthquakes follow this earthquake and continue till now. For this reason, 13 seismograph stations (radio-telemetry network short-period seismometers) were installed around the northern part of Lake Aswan. The main purpose of the network is to monitor the earthquake activity continuously within Aswan region. The data described here are obtained from the continuous record of earthquake activity and lake-water level variation through the period from 1982 to 2015. The seismicity is concentrated in the Kalabsha area, where there is an intersection of the easterly trending Kalabsha fault with the northerly trending faults. The earthquake foci are distributed in two seismic zones, shallow and deep in the crust. Shallow events have focal depths of less than 12 km while deep events extend from 12 to 28 km. Correlation between the seismicity and the water level variation in the lake provides great suggestion to distinguish the micro-earthquakes, particularly, those in shallow seismic zone in the reservoir–triggered seismicity category. The water loading is one factor from several factors, as an activating medium in triggering earthquakes. The common factors for all cases of induced seismicity seem to be the presence of specific geological conditions, the tectonic setting and water loading. The role of the water loading is as a supplementary source of earthquake events. So, the earthquake activity in the area originated tectonically (ML ≥ 4) and the water factor works as an activating medium in triggering small earthquakes (ML ≤ 3). Study of the inducing seismicity from the water level variation in Aswan Lake is of great importance and play great roles necessity for the safety of the High Dam body and its economic resources.

Keywords: Aswan lake, Aswan seismic network, seismicity, water level variation

Procedia PDF Downloads 350
683 First-Trimester Screening of Preeclampsia in a Routine Care

Authors: Tamar Grdzelishvili, Zaza Sinauridze

Abstract:

Introduction: Preeclampsia is a complication of the second trimester of pregnancy, which is characterized by high morbidity and multiorgan damage. Many complex pathogenic mechanisms are now implicated to be responsible for this disease (1). Preeclampsia is one of the leading causes of maternal mortality worldwide. Statistics are enough to convince you of the seriousness of this pathology: about 100,000 women die of preeclampsia every year. It occurs in 3-14% (varies significantly depending on racial origin or ethnicity and geographical region) of pregnant women, in 75% of cases - in a mild form, and in 25% - in a severe form. During severe pre-eclampsia-eclampsia, perinatal mortality increases by 5 times and stillbirth by 9.6 times. Considering that the only way to treat the disease is to end the pregnancy, the main thing is timely diagnosis and prevention of the disease. Identification of high-risk pregnant women for PE and giving prophylaxis would reduce the incidence of preterm PE. First-trimester screening model developed by the Fetal Medicine Foundation (FMF), which uses the Bayes-theorem to combine maternal characteristics and medical history together with measurements of mean arterial pressure, uterine artery pulsatility index, and serum placental growth factor, has been proven to be effective and have superior screening performance to that of traditional risk factor-based approach for the prediction of PE (2) Methods: Retrospective single center screening study. The study population consisted of women from the Tbilisi maternity hospital “Pineo medical ecosystem” who met the following criteria: they spoke Georgian, English, or Russian and agreed to participate in the study after discussing informed consent and answering questions. Prior to the study, the informed consent forms approved by the Institutional Review Board were obtained from the study subjects. Early assessment of preeclampsia was performed between 11-13 weeks of pregnancy. The following were evaluated: anamnesis, dopplerography of the uterine artery, mean arterial blood pressure, and biochemical parameter: Pregnancy-associated plasma protein A (PAPP-A). Individual risk assessment was performed with performed by Fast Screen 3.0 software ThermoFisher scientific. Results: A total of 513 women were recruited and through the study, 51 women were diagnosed with preeclampsia (34.5% in the pregnant women with high risk, 6.5% in the pregnant women with low risk; P<0.000 1). Conclusions: First-trimester screening combining maternal factors with uterine artery Doppler, blood pressure, and pregnancy-associated plasma protein-A is useful to predict PE in a routine care setting. More patient studies are needed for final conclusions. The research is still ongoing.

Keywords: first-trimester, preeclampsia, screening, pregnancy-associated plasma protein

Procedia PDF Downloads 60
682 Determination Optimum Strike Price of FX Option Call Spread with USD/IDR Volatility and Garman–Kohlhagen Model Analysis

Authors: Bangkit Adhi Nugraha, Bambang Suripto

Abstract:

On September 2016 Bank Indonesia (BI) release regulation no.18/18/PBI/2016 that permit bank clients for using the FX option call spread USD/IDR. Basically, this product is a combination between clients buy FX call option (pay premium) and sell FX call option (receive premium) to protect against currency depreciation while also capping the potential upside with cheap premium cost. BI classifies this product as a structured product. The structured product is combination at least two financial instruments, either derivative or non-derivative instruments. The call spread is the first structured product against IDR permitted by BI since 2009 as response the demand increase from Indonesia firms on FX hedging through derivative for protecting market risk their foreign currency asset or liability. The composition of hedging products on Indonesian FX market increase from 35% on 2015 to 40% on 2016, the majority on swap product (FX forward, FX swap, cross currency swap). Swap is formulated by interest rate difference of the two currency pairs. The cost of swap product is 7% for USD/IDR with one year USD/IDR volatility 13%. That cost level makes swap products seem expensive for hedging buyers. Because call spread cost (around 1.5-3%) cheaper than swap, the most Indonesian firms are using NDF FX call spread USD/IDR on offshore with outstanding amount around 10 billion USD. The cheaper cost of call spread is the main advantage for hedging buyers. The problem arises because BI regulation requires the call spread buyer doing the dynamic hedging. That means, if call spread buyer choose strike price 1 and strike price 2 and volatility USD/IDR exchange rate surpass strike price 2, then the call spread buyer must buy another call spread with strike price 1’ (strike price 1’ = strike price 2) and strike price 2’ (strike price 2’ > strike price 1‘). It could make the premium cost of call spread doubled or even more and dismiss the purpose of hedging buyer to find the cheapest hedging cost. It is very crucial for the buyer to choose best optimum strike price before entering into the transaction. To help hedging buyer find the optimum strike price and avoid expensive multiple premium cost, we observe ten years 2005-2015 historical data of USD/IDR volatility to be compared with the price movement of the call spread USD/IDR using Garman–Kohlhagen Model (as a common formula on FX option pricing). We use statistical tools to analysis data correlation, understand nature of call spread price movement over ten years, and determine factors affecting price movement. We select some range of strike price and tenor and calculate the probability of dynamic hedging to occur and how much it’s cost. We found USD/IDR currency pairs is too uncertain and make dynamic hedging riskier and more expensive. We validated this result using one year data and shown small RMS. The study result could be used to understand nature of FX call spread and determine optimum strike price for hedging plan.

Keywords: FX call spread USD/IDR, USD/IDR volatility statistical analysis, Garman–Kohlhagen Model on FX Option USD/IDR, Bank Indonesia Regulation no.18/18/PBI/2016

Procedia PDF Downloads 362
681 The Effectiveness of Multiphase Flow in Well- Control Operations

Authors: Ahmed Borg, Elsa Aristodemou, Attia Attia

Abstract:

Well control involves managing the circulating drilling fluid within the wells and avoiding kicks and blowouts as these can lead to losses in human life and drilling facilities. Current practices for good control incorporate predictions of pressure losses through computational models. Developing a realistic hydraulic model for a good control problem is a very complicated process due to the existence of a complex multiphase region, which usually contains a non-Newtonian drilling fluid and the miscibility of formation gas in drilling fluid. The current approaches assume an inaccurate flow fluid model within the well, which leads to incorrect pressure loss calculations. To overcome this problem, researchers have been considering the more complex two-phase fluid flow models. However, even these more sophisticated two-phase models are unsuitable for applications where pressure dynamics are important, such as in managed pressure drilling. This study aims to develop and implement new fluid flow models that take into consideration the miscibility of fluids as well as their non-Newtonian properties for enabling realistic kick treatment. furthermore, a corresponding numerical solution method is built with an enriched data bank. The research work considers and implements models that take into consideration the effect of two phases in kick treatment for well control in conventional drilling. In this work, a corresponding numerical solution method is built with an enriched data bank. Software STARCCM+ for the computational studies to study the important parameters to describe wellbore multiphase flow, the mass flow rate, volumetric fraction, and velocity of each phase. Results showed that based on the analysis of these simulation studies, a coarser full-scale model of the wellbore, including chemical modeling established. The focus of the investigations was put on the near drill bit section. This inflow area shows certain characteristics that are dominated by the inflow conditions of the gas as well as by the configuration of the mud stream entering the annulus. Without considering the gas solubility effect, the bottom hole pressure could be underestimated by 4.2%, while the bottom hole temperature is overestimated by 3.2%. and without considering the heat transfer effect, the bottom hole pressure could be overestimated by 11.4% under steady flow conditions. Besides, larger reservoir pressure leads to a larger gas fraction in the wellbore. However, reservoir pressure has a minor effect on the steady wellbore temperature. Also as choke pressure increases, less gas will exist in the annulus in the form of free gas.

Keywords: multiphase flow, well- control, STARCCM+, petroleum engineering and gas technology, computational fluid dynamic

Procedia PDF Downloads 96
680 A Sociological Study of the Potential Role of Retired Soldiers in the Post War Development and Reconstruction in Sri Lanka

Authors: Amunupura Kiriwandeiye Gedara, Asintha Saminda Gnanaratne

Abstract:

The security forces can be described as a workforce that goes beyond the role of ensuring the national security and contributes to the development process of the country. Soldiers are following combatant training courses during their tenure, they are equipped with a variety of vocational training courses to satisfy the needs of the army, to equip them with vocational training capabilities to achieve the development and reconstruction goals of the country as well as for the betterment of society in the event of emergencies. But with retirement, their relationship with the military is severed, and they are responsible for the future of their lives. The main purpose of this study was to examine how such professional capabilities can contribute to the development of the country, the current socio-economic status of the retired soldiers, and the current application of the vocational training skills they have mastered in the army to develop and rebuild the country in an effective manner. After analyzing the available research literature related to this field, a conceptual framework was developed and according to qualitative research methodology, and data obtained from Case studies and interviews are analyzed by using thematic analysis. Factors influencing early retirement include a lack of understanding of benefits, delays in promotions, not being properly evaluated for work, getting married on hasty decisions, and not having enough time to spend on family and household chores. Most of the soldiers are not aware about various programs and benefits available to retirees. They do not have a satisfactory attitude towards the retirement guidance they receive from the army at the time of retirement. Also, due to the lack of understanding about how to use their vocational capabilities successfully pursue their retirement life, the majority of people are employed in temporary jobs, and some are successful in post-retirement life due to their successful use of training received. Some live on pensions without engaging in any income-generating activities, and those who retire after 12 years of service are facing severe economic hardships as they do not get pensions. Although they have received training in various fields, they do not use them for their benefit due to lack of proper guidance. Although the government implements programs, they are not clearly aware of them. Barriers to utilization of training include an absence of a system to identify the professional skills of retired soldiers, interest in civil society affairs, exploration of opportunities in the civil and private sectors, and politicization of services. If they are given the opportunity, they will be able to contribute to the development and reconstruction process. The findings of the study further show that it has many social, economic, political, and psychological benefits not only for individuals but also for a country. Entrepreneurship training for all retired soldiers, improving officers' understanding, streamlining existing mechanisms, creating new mechanisms, setting up a separate unit for retirees, and adapting them to civil society, private and non-governmental contributions, and training courses can be identified as potential means to improve the current situation.

Keywords: development, reconstruction, retired soldiers, vocational capabilities

Procedia PDF Downloads 106
679 Meeting the Health Needs of Adolescents and Young Adults: Developing and Evaluating an Electronic Questionnaire and Health Report Form, for the Health Assessment at Youth Health Clinics – A Mixed Methods Project

Authors: P.V. Lostelius, M.Mattebo, E. Thors Adolfsson, A. Söderlund, Å. Revenäs

Abstract:

Adolescents are vulnerable in healthcare settings. Early detection of poor health in young people is important to support a good quality of life and adult social functioning. Youth Health Clinics (YHCs) in Sweden provide healthcare for young people ages 13-25 years old. Using an overall mixed methods approach, the project’s main objective was to develop and evaluate an electronic health system, including a health questionnaire, a case report form, and an evaluation questionnaire to assess young people’s health risks in early stages, increase health, and quality of life. In total, 72 young people, 16-23 years old, eleven healthcare professionals and eight researchers participated in the three project studies. Results from interviews with fifteen young people gave that an electronic health questionnaire should include questions about physical-, mental-, sexual health and social support. It should specifically include questions about self-harm and suicide risk. The young people said that the questionnaire should be appealing, based on young people’s needs and be user-friendly. It was important that young people felt safe when responding to the questions, both physically and electronically. Also, they found that it had the potential to support the face-to face-meeting between young people and healthcare professionals. The electronic health report system was developed by the researchers, performing a structured development of the electronic health questionnaire, construction of a case report form to present the results from the health questions, along with an electronic evaluation questionnaire. An Information Technology company finalized the development by digitalizing the electronic health system. Four young people, three healthcare professionals and seven researchers evaluated the usability using interviews and a usability questionnaire. The electronic health questionnaire was found usable for YHCs but needed some clarifications. Essentially, the system succeeded in capturing the overall health of young people; it should be able to keep the interest of young people and have the potential to contribute to health assessment planning and young people’s self-reflection, sharing vulnerable feelings with healthcare professionals. In advance of effect studies, a feasibility study was performed by collecting electronic questionnaire data from 54 young people and interview data from eight healthcare professionals to assess the feasibility of the use of the electronic evaluation questionnaire, the case report form, and the planned recruitment method. When merging the results, the research group found that the evaluation questionnaire and the health report were feasible for future research. However, the COVID-19 pandemic, commitment challenges and drop-outs affected the recruitment of young people. Also, some healthcare professionals felt insecure about using computers and electronic devices and worried that their workload would increase. This project contributes knowledge about the development and use of electronic health tools for young people. Before implementation, clinical routines need for using the health report system need to be considered.

Keywords: adolescent health, developmental studies, electronic health questionnaire, mixed methods research

Procedia PDF Downloads 78
678 A Hybrid Film: NiFe₂O₄ Nanoparticles in Poly-3-Hydroxybutyrate as an Antibacterial Agent

Authors: Karen L. Rincon-Granados, América R. Vázquez-Olmos, Adriana-Patricia Rodríguez-Hernández, Gina Prado-Prone, Margarita Rivera, Roberto Y. Sato-Berrú

Abstract:

In this work, a hybrid film based on poly-3-hydroxybutyrate (P3HB) and nickel ferrite (NiFe₂O₄) nanoparticles (NPs) was obtained by a simple and reproducible methodology in order to study its antibacterial and cytotoxic properties. The motivation for this research is the current antimicrobial resistance (RAM). This is a threat to human health and development worldwide. RAM is caused by the emergence of bacterial strains resistant to traditional antibiotics that were used as treatment. Due to this, the need to investigate new alternatives for preventing and treating bacterial infections emerges. In this sense, metal oxide NPs have aroused great interest due to their unique physicochemical properties. However, their use is limited by the nanostructured nature, commonly obtained by chemical and physical synthesis methods, as powders or colloidal dispersions. Therefore, the incorporation of nanostructured materials in polymer matrices to obtain hybrid materials that allow disinfecting and preventing the spread of bacteria on various surfaces. Accordingly, this work presents the synthesis and study of the antibacterial properties of the P3HB@NiFe₂O₄ hybrid film as a potential material to inhibit bacterial growth. The NiFe₂O₄ NPs were previously synthesized by a mechanochemical method. The P3HB and P3HB@NiFe₂O₄ films were obtained by the solvent casting method. The films were characterized by X-ray diffraction (XRD), Raman scattering, and scanning electron microscopy (SEM). The XRD pattern showed that the NiFe₂O₄ NPs were incorporated into the P3HB polymer matrix and retained their nanometric sizes. By energy dispersive X-ray spectroscopy (EDS), it was observed that the NPs are homogeneously distributed in the film. The bactericidal effect of the films obtained was evaluated in vitro using the broth surface method against two opportunistic and nosocomial pathogens, Staphylococcus aureus and Pseudomonas aeruginosa. The bacterial growth results showed that the P3HB@NiFe₂O₄ hybrid film was inhibited by 97% and 96% for S. aureus and P. aeruginosa, respectively. Surprisingly, the P3HB film inhibited both bacterial strains by around 90%. The cytotoxicity of the NiFe₂O₄ NPs, P3HB@NiFe₂O₄ hybrid film, and the P3HB film was evaluated using human skin cells, keratinocytes, and fibroblasts, finding that the NPs are biocompatible. The P3HB film and hybrids are cytotoxic, which demonstrated that although P3HB is known and reported as a biocompatible polymer, under our work conditions, P3HB was cytotoxic. Its bactericidal effect could be related to this activity. Its films are bactericidal and cytotoxic to keratinocytes and fibroblasts, the first barrier of human skin. Despite this, the hybrid film of P3HB@NiFe₂O₄ presents synergy with the bactericidal effect between P3HB and NPs, increasing bacterial inhibition. In addition, NPs decrease the cytotoxicity of P3HB to keratinocytes. The methodology used in this work was successful in producing hybrid films with antibacterial activity. However, future challenges are generated to find relationships between NPs and P3HB that allow taking advantage of their bactericidal properties and do not compromise biocompatibility.

Keywords: poly-3-hydroxybutyrate, nanoparticles, hybrid film, antibacterial

Procedia PDF Downloads 58
677 Flexural Performance of the Sandwich Structures Having Aluminum Foam Core with Different Thicknesses

Authors: Emre Kara, Ahmet Fatih Geylan, Kadir Koç, Şura Karakuzu, Metehan Demir, Halil Aykul

Abstract:

The structures obtained with the use of sandwich technologies combine low weight with high energy absorbing capacity and load carrying capacity. Hence, there is a growing and markedly interest in the use of sandwiches with aluminium foam core because of very good properties such as flexural rigidity and energy absorption capability. The static (bending and penetration) and dynamic (dynamic bending and low velocity impact) tests were already performed on the aluminum foam cored sandwiches with different types of outer skins by some of the authors. In the current investigation, the static three-point bending tests were carried out on the sandwiches with aluminum foam core and glass fiber reinforced polymer (GFRP) skins at different values of support span distances (L= 55, 70, 80, 125 mm) aiming the analyses of their flexural performance. The influence of the core thickness and the GFRP skin type was reported in terms of peak load, energy absorption capacity and energy efficiency. For this purpose, the skins with two different types of fabrics ([0°/90°] cross ply E-Glass Woven and [0°/90°] cross ply S-Glass Woven which have same thickness value of 1.5 mm) and the aluminum foam core with two different thicknesses (h=10 and 15 mm) were bonded with a commercial polyurethane based flexible adhesive in order to combine the composite sandwich panels. The GFRP skins fabricated via Vacuum Assisted Resin Transfer Molding (VARTM) technique used in the study can be easily bonded to the aluminum foam core and it is possible to configure the base materials (skin, adhesive and core), fiber angle orientation and number of layers for a specific application. The main results of the bending tests are: force-displacement curves, peak force values, absorbed energy, energy efficiency, collapse mechanisms and the effect of the support span length and core thickness. The results of the experimental study showed that the sandwich with the skins made of S-Glass Woven fabrics and with the thicker foam core presented higher mechanical values such as load carrying and energy absorption capacities. The increment of the support span distance generated the decrease of the mechanical values for each type of panels, as expected, because of the inverse proportion between the force and span length. The most common failure types of the sandwiches are debonding of the upper or lower skin and the core shear. The obtained results have particular importance for applications that require lightweight structures with a high capacity of energy dissipation, such as the transport industry (automotive, aerospace, shipbuilding and marine industry), where the problems of collision and crash have increased in the last years.

Keywords: aluminum foam, composite panel, flexure, transport application

Procedia PDF Downloads 312
676 Artificial Cells Capable of Communication by Using Polymer Hydrogel

Authors: Qi Liu, Jiqin Yao, Xiaohu Zhou, Bo Zheng

Abstract:

The first artificial cell was produced by Thomas Chang in the 1950s when he was trying to make a mimic of red blood cells. Since then, many different types of artificial cells have been constructed from one of the two approaches: a so-called bottom-up approach, which aims to create a cell from scratch, and a top-down approach, in which genes are sequentially knocked out from organisms until only the minimal genome required for sustaining life remains. In this project, bottom-up approach was used to build a new cell-free expression system which mimics artificial cell that capable of protein expression and communicate with each other. The artificial cells constructed from the bottom-up approach are usually lipid vesicles, polymersomes, hydrogels or aqueous droplets containing the nucleic acids and transcription-translation machinery. However, lipid vesicles based artificial cells capable of communication present several issues in the cell communication research: (1) The lipid vesicles normally lose the important functions such as protein expression within a few hours. (2) The lipid membrane allows the permeation of only small molecules and limits the types of molecules that can be sensed and released to the surrounding environment for chemical communication; (3) The lipid vesicles are prone to rupture due to the imbalance of the osmotic pressure. To address these issues, the hydrogel-based artificial cells were constructed in this work. To construct the artificial cell, polyacrylamide hydrogel was functionalized with Acrylate PEG Succinimidyl Carboxymethyl Ester (ACLT-PEG2000-SCM) moiety on the polymer backbone. The proteinaceous factors can then be immobilized on the polymer backbone by the reaction between primary amines of proteins and N-hydroxysuccinimide esters (NHS esters) of ACLT-PEG2000-SCM, the plasmid template and ribosome were encapsulated inside the hydrogel particles. Because the artificial cell could continuously express protein with the supply of nutrients and energy, the artificial cell-artificial cell communication and artificial cell-natural cell communication could be achieved by combining the artificial cell vector with designed plasmids. The plasmids were designed referring to the quorum sensing (QS) system of bacteria, which largely relied on cognate acyl-homoserine lactone (AHL) / transcription pairs. In one communication pair, “sender” is the artificial cell or natural cell that can produce AHL signal molecule by synthesizing the corresponding signal synthase that catalyzed the conversion of S-adenosyl-L-methionine (SAM) into AHL, while the “receiver” is the artificial cell or natural cell that can sense the quorum sensing signaling molecule form “sender” and in turn express the gene of interest. In the experiment, GFP was first immobilized inside the hydrogel particle to prove that the functionalized hydrogel particles could be used for protein binding. After that, the successful communication between artificial cell-artificial cell and artificial cell-natural cell was demonstrated, the successful signal between artificial cell-artificial cell or artificial cell-natural cell could be observed by recording the fluorescence signal increase. The hydrogel-based artificial cell designed in this work can help to study the complex communication system in bacteria, it can also be further developed for therapeutic applications.

Keywords: artificial cell, cell-free system, gene circuit, synthetic biology

Procedia PDF Downloads 128
675 Factors of Self-Sustainability in Social Entrepreneurship: Case Studies of ACT Group Čakovec and Friskis and Svettis Stockholm

Authors: Filip Majetić, Dražen Šimleša, Jelena Puđak, Anita Bušljeta Tonković, Svitlana Pinchuk

Abstract:

This paper focuses on the self-sustainability aspect of social entrepreneurship (SE). We define SE as a form of entrepreneurship that is social/ecological mission oriented. It means SE organizations start and run businesses and use them to accomplish their social/ecological missions i.e. to solve social/ecological problems or fulfill social/ecological needs. Self-sustainability is defined as the capability of an SE organization to operate by relying on the money earned through trading its products in the free market. For various reasons, the achievement of self-sustainability represents a fundamental (business) challenge for many SE organizations. Those that are not able to operate using the money made through commercial activities, in order to remain active, rely on alternative, non-commercial streams of income such as grants, donations, and public subsidies. Starting from this widespread (business) challenge, we are interested in exploring elements that (could) influence the self-sustainability in SE organizations. Therefore, the research goal is to empirically investigate some of the self-sustainability factors of two notable SE organizations from different socio-economic contexts. A qualitative research, using the multiple case study approach, was conducted. ACT Group Čakovec (ACT) from Croatia was selected for the first case because it represents one of the leading and most self-sustainable SE organization in the region (in 2015 55% of the organization’s budget came from commercial activities); Friskis&Svettis Stockholm (F&S) from Sweden was selected for the second case because it is a rare example of completely self-sustainable SE organization in Europe (100% of the organization’s budget comes from commercial activities). The data collection primarily consists of conducting in-depth interviews. Additionally, the content of some of the organizations' official materials are analyzed (e.g. business reports, marketing materials). The interviewees are selected purposively and include: six highly ranked F&S members who represent five different levels in the hierarchy of their organization; five highly ranked ACT members who represent three different levels in the hierarchy of the organization. All of the interviews contain five themes: a) social values of the organization, b) organization of work, c) non-commercial income sources, d) marketing/collaborations, and e) familiarity with the industry characteristics and trends. The gathered data is thematically analyzed through the coding process for which Atlas.ti software for qualitative data analysis is used. For the purpose of creating thematic categories (codes), the open coding is used. The research results intend to provide new theoretical insights on factors of SE self-sustainability and, preferably, encourage practical improvements in the field.

Keywords: Friskis&Svettis, self-sustainability factors, social entrepreneurship, Stockholm

Procedia PDF Downloads 194
674 A Mixed Integer Linear Programming Model for Container Collection

Authors: J. Van Engeland, C. Lavigne, S. De Jaeger

Abstract:

In the light of the transition towards a more circular economy, recovery of products, parts or materials will gain in importance. Additionally, the EU proximity principle related to waste management and emissions generated by transporting large amounts of end-of-life products, shift attention to local recovery networks. The Flemish inter-communal cooperation for municipal solid waste management Meetjesland (IVM) is currently investigating the set-up of such a network. More specifically, the network encompasses the recycling of polyvinyl chloride (PVC), which is collected in separate containers. When these containers are full, a truck should transport them to the processor which can recycle the PVC into new products. This paper proposes a model to optimize the container collection. The containers are located at different Civic Amenity sites (CA sites) in a certain region. Since people can drop off their waste at these CA sites, the containers will gradually fill up during a planning horizon. If a certain container is full, it has to be collected and replaced by an empty container. The collected waste is then transported to a single processor. To perform this collection and transportation of containers, the responsible firm has a set of vehicles stationed at a single depot and different personnel crews. A vehicle can load exactly one container. If a trailer is attached to the vehicle, it can load an additional container. Each day of the planning horizon, the different crews and vehicles leave the depot to collect containers at the different sites. After loading one or two containers, the crew has to drive to the processor for unloading the waste and to pick up empty containers. Afterwards, the crew can again visit sites or it can return to the depot to end its collection work for that day. All along the collection process, the crew has to respect the opening hours of the sites. In order to allow for some flexibility, a crew is allowed to wait a certain amount of time at the gate of a site until it opens. The problem described can be modelled as a variant to the PVRP-TW (Periodic Vehicle Routing Problem with Time Windows). However, a vehicle can at maximum load two containers, hence only two subsequent site visits are possible. For that reason, we will refer to the model as a model for building tactical waste collection schemes. The goal is to a find a schedule describing which crew should visit which CA site on which day to minimize the number of trucks and the routing costs. The model was coded in IBM CPLEX Optimization studio and applied to a number of test instances. Good results were obtained, and specific suggestions concerning route and truck costs could be made. For a large range of input parameters, collection schemes using two trucks are obtained.

Keywords: container collection, crew scheduling, mixed integer linear programming, waste management

Procedia PDF Downloads 110
673 Coupled Field Formulation – A Unified Method for Formulating Structural Mechanics Problems

Authors: Ramprasad Srinivasan

Abstract:

Engineers create inventions and put their ideas in concrete terms to design new products. Design drivers must be established, which requires, among other things, a complete understanding of the product design, load paths, etc. For Aerospace Vehicles, weight/strength ratio, strength, stiffness and stability are the important design drivers. A complex built-up structure is made up of an assemblage of primitive structural forms of arbitrary shape, which include 1D structures like beams and frames, 2D structures like membranes, plate and shell structures, and 3D solid structures. Justification through simulation involves a check for all the quantities of interest, namely stresses, deformation, frequencies, and buckling loads and is normally achieved through the finite element (FE) method. Over the past few decades, Fiber-reinforced composites are fast replacing the traditional metallic structures in the weight-sensitive aerospace and aircraft industries due to their high specific strength, high specific stiffness, anisotropic properties, design freedom for tailoring etc. Composite panel constructions are used in aircraft to design primary structure components like wings, empennage, ailerons, etc., while thin-walled composite beams (TWCB) are used to model slender structures like stiffened panels, helicopter, and wind turbine rotor blades, etc. The TWCB demonstrates many non-classical effects like torsional and constrained warping, transverse shear, coupling effects, heterogeneity, etc., which makes the analysis of composite structures far more complex. Conventional FE formulations to model 1D structures suffer from many limitations like shear locking, particularly in slender beams, lower convergence rates due to material coupling in composites, inability to satisfy, equilibrium in the domain and natural boundary conditions (NBC) etc. For 2D structures, the limitations of conventional displacement-based FE formulations include the inability to satisfy NBC explicitly and many pathological problems such as shear and membrane locking, spurious modes, stress oscillations, lower convergence due to mesh distortion etc. This mandates frequent re-meshing to even achieve an acceptable mesh (satisfy stringent quality metrics) for analysis leading to significant cycle time. Besides, currently, there is a need for separate formulations (u/p) to model incompressible materials, and a single unified formulation is missing in the literature. Hence coupled field formulation (CFF) is a unified formulation proposed by the author for the solution of complex 1D and 2D structures addressing the gaps in the literature mentioned above. The salient features of CFF and its many advantages over other conventional methods shall be presented in this paper.

Keywords: coupled field formulation, kinematic and material coupling, natural boundary condition, locking free formulation

Procedia PDF Downloads 54
672 Exploring the Treatment of Unmarried Female Adolescents (10-19 Years) at Health Facilities during the Maternity Period in Uganda

Authors: Peninah Agaba, Monica Magadi, Bev Orton

Abstract:

Uganda is one of the countries with high maternal mortality (336/100,000) where adolescents account for 24 percent of the total maternal deaths. Research shows that use of maternal health services may prevent some of these deaths and good provider attitudes attract adolescents to use the services. However, poor health provider’s attitudes discourage adolescents from seeking the services during the maternity period. This study explores the experiences of unmarried female adolescents at the health facilities during the maternity period. The study population is unmarried adolescent girls aged 10-19 years who were pregnant or had given birth within three years before the interview. This is a special interest group that requires attention throughout this period. Most of the pregnancies among unmarried adolescents are unwanted; as a result, many of them have been abused and neglected by parents and close family members including partners who deny fatherhood of the pregnancy/child. These adolescents hope to find comfort from health providers like being listened to during counseling, not abused and judged; unfortunately this is not the case always. The research was approved by the University of Hull, School of Education and Social Sciences ethics review committee, Mildmay Uganda Research Ethics Committee and Uganda National Council of Science and Technology. The study was carried out in Bushenyi and Kibale districts in Western Uganda. Fourteen in-depth interviews and seven focus group discussions were completed in the local languages and later transcribed to English language. Thematic analysis to identify the themes was done. Adolescents were aged 16-19 years, two had become pregnant before 15 years. Most had not completed secondary education; none had tertiary education and three of the 14 IDI adolescent participants wanted to get pregnant. Analysis shows varied experiences; most adolescents were abused verbally and physically by the health providers due to their young age of pregnancy, lack of essential items during this period (maternity dresses, children clothes, delivery kit) and fear of labour pains. Another cause for abuse was these adolescents coming for antenatal care with no partners yet the implementation of a policy on increasing male involvement in reproductive health in Uganda requires them to attend antenatal care with their partners and most of these unmarried adolescents have no partners to accompany them. Despite the above challenges, the study also identified the care some of these unmarried adolescents received during the maternity visits for example they were not abused, were provided with appropriate information and supported with child care. The study identified abuse and support the unmarried adolescents received during the maternity period. Efforts to provide adolescents with adequate information including what to expect during labour by providers and provision of basic needs are essential. Health providers should have trainings on client care especially how to embrace unmarried adolescents when they come to access maternity services. More so, the policy on improving male involvement in RH issues need to be considerate of unmarried adolescents who in most cases do not have the partners to go with to access maternity care.

Keywords: abuse, maternity care, Uganda, unmarried, adolescents

Procedia PDF Downloads 112
671 Scenario of Some Minerals and Impact of Promoter Hypermethylation of DAP-K Gene in Gastric Carcinoma Patients of Kashmir Valley

Authors: Showkat Ahmad Bhat, Iqra Reyaz, Falaque ul Afshan, Ahmad Arif Reshi, Muneeb U. Rehman, Manzoor R. Mir, Sabhiya Majid, Sonallah, Sheikh Bilal, Ishraq Hussain

Abstract:

Background: Gastric cancer is the fourth most common cancer and the second leading cause of worldwide cancer-related deaths, with a wide variation in incidence rates across different geographical areas. The current view of cancer is that a malignancy arises from a transformation of the genetic material of a normal cell, followed by successive mutations and by chain of alterations in genes such as DNA repair genes, oncogenes, Tumor suppressor genes. Minerals are necessary for the functioning of several transcriptional factors, proteins that recognize certain DNA sequences and have been found to play a role in gastric cancer. Material Methods:The present work was a case control study and its aim was to ascertain the role of minerals and promoter hypermethylation of CpG islands of DAP-K gene in Gastric cancer patients among the Kashmiri population. Serum was extracted from all the samples and mineral estimation was done by AAS from serum, DNA was also extracted and was modified using bisulphite modification kit. Methylation-specific PCR was used for the analysis of the promoter hypermethylation status of DAP-K gene. The epigenetic analysis revealed that unlike other high risk regions, Kashmiri population has a different promoter hypermethylation profile of DAP-K gene and has different mineral profile. Results: In our study mean serum copper levels were significantly different for the two genders (p<0.05), while as no significant differences were observed for iron and zinc levels. In Methylation-specific PCR the methylation status of the promoter region of DAP-K gene was as 67.50% (27/40) of the gastric cancer tissues showed methylated DAP-K promoter and 32.50% (13/40) of the cases however showed unmethylated DAP-K promoter. Almost all 85% (17/20) of the histopathologically confirmed normal tissues showed unmethylated DAP-K promoter except only in 3 cases where DAP-K promoter was found to be methylated. The association of promoter hypermethylation with gastric cancer was evaluated by χ2 (Chi square) test and was found to be significant (P=0.0006). Occurrence of DAP-K methylation was found to be unequally distributed in males and females with more frequency in males than in females but the difference was not statistically significant (P =0.7635, Odds ratio=1.368 and 95% C.I=0.4197 to 4.456). When the frequency of DAP-K promoter methylation was compared with clinical staging of the disease, DAP-K promoter methylation was found to be certainly higher in Stage III/IV (85.71%) compared to Stage I/ II (57.69%) but the difference was not statistically significant (P =0.0673). These results suggest that DAP-K aberrant promoter hypermethylation in Kashmiri population contributes to the process of carcinogenesis in Gastric cancer and is reportedly one of the commonest epigenetic changes in the development of Gastric cancer.

Keywords: gastric cancer, minerals, AAS, hypermethylation, CpG islands, DAP-K gene

Procedia PDF Downloads 500
670 A Delphi Study to Build Consensus for Tuberculosis Control Guideline to Achieve Who End Tb 2035 Strategy

Authors: Pui Hong Chung, Cyrus Leung, Jun Li, Kin On Kwok, Ek Yeoh

Abstract:

Introduction: Studies for TB control in intermediate tuberculosis burden countries (IBCs) comprise a relatively small proportion in TB control literature, as compared to the effort put in high and low burden counterparts. It currently lacks of consensus in the optimal weapons and strategies we can use to combat TB in IBCs; guidelines of TB control are inadequate and thus posing a great obstacle in eliminating TB in these countries. To fill-in the research and services gap, we need to summarize the findings of the effort in this regard and to seek consensus in terms of policy making for TB control, we have devised a series of scoping and Delphi studies for these purposes. Method: The scoping and Delphi studies are conducted in parallel to feed information for each other. Before the Delphi iterations, we have invited three local experts in TB control in Hong Kong to participate in the pre-assessment round of the Delphi study to comments on the validity, relevance, and clarity of the Delphi questionnaire. Result: Two scoping studies, regarding LTBI control in health care workers in IBCs and TB control in elderly of IBCs respectively, have been conducted. The result of these two studies is used as the foundation for developing the Delphi questionnaire, which tapped on seven areas of question, namely: characteristics of IBCs, adequacy of research and services in LTBI control in IBCs, importance and feasibility of interventions for TB control and prevention in hospital, screening and treatment of LTBI in community, reasons of refusal to/ default from LTBI treatment, medical adherence of LTBI treatment, and importance and feasibility of interventions for TB control and prevention in elderly in IBCs. The local experts also commented on the two scoping studies conducted, thus act as the sixth phase of expert consultation in Arksey and O’Malley framework of scoping studies, to either nourish the scope and strategies used in these studies or to supplement ideas for further scoping or systematic review studies. In the subsequent stage, an international expert panel, comprised of 15 to 20 experts from IBCs in Western Pacific Region, will be recruited to join the two-round anonymous Delphi iterations. Four categories of TB control experts, namely clinicians, policy makers, microbiologists/ laboratory personnel, and public health clinicians will be our target groups. A consensus level of 80% is used to determine the achievement of consensus on particular issues. Key messages: 1. Scoping review and Delphi method are useful to identify gaps and then achieve consensus in research. 2. Lots of resources are put in the high burden countries now. However, the usually neglected intermediate-burden countries with TB is an indispensable part for achieving the ambitious WHO End TB 2035 target.

Keywords: dephi questionnaire, tuberculosis, WHO, latent TB infection

Procedia PDF Downloads 269
669 Dengue Prevention and Control in Kaohsiung City

Authors: Chiu-Wen Chang, I-Yun Chang, Wei-Ting Chen, Hui-Ping Ho, Ruei-Hun Chang, Joh-Jong Huang

Abstract:

Kaohsiung City is located in the tropical region where has Aedes aegypti and Aedes albopictus distributed; once the virus invades, it’s can easily trigger local epidemic. Besides, Kaohsiung City has a world-class airport and harbor, trade and tourism are close and frequently with every country, especially with the Southeast Asian countries which also suffer from dengue. Therefore, Kaohsiung City faces the difficult challenge of dengue every year. The objectives of this study was to enhance dengue clinical care, border management and vector surveillance in Kaohsiung City by establishing an larger scale, innovatively and more coordinated dengue prevention and control strategies in 2016, including (1) Integrated medical programs: facilitated 657 contract medical institutions, widely set up NS1 rapid test in clinics, enhanced triage and referrals system, dengue case daily-monitoring management (2) Border quarantine: comprehensive NS1 screening for foreign workers and fisheries when immigration, hospitalization and isolation for suspected cases, health education for high risk groups (foreign students, other tourists) (3) Mosquito control: Widely use Gravitrap to monitor mosquito density in environment, use NS1 rapid screening test to detect community dengue virus (4) Health education: create a dengue app for people to immediately inquire the risk map and nearby medical resources, routine health education to all districts to strengthen public’s dengue knowledge, neighborhood cleaning awards program. The results showed that after new integration of dengue prevention and control strategies fully implemented in Kaohsiung City, the number of confirmed cases in 2016 declined to 342 cases, the majority of these cases are the continuation epidemic in 2015; in fact, only two cases confirmed after the 2016 summer. Besides, the dengue mortality rate successfully decreased to 0% in 2016. Moreover, according to the reporting rate from medical institutions in 2014 and 2016, it dropped from 27.07% to 19.45% from medical center, and it decreased from 36.55% to 29.79% from regional hospital; however, the reporting rate of district hospital increased from 11.88% to 15.87% and also increased from 24.51% to 34.89% in general practice clinics. Obviously, it showed that under the action of strengthening medical management, it reduced the medical center’s notification ratio and improved the notification ratio of general clinics which achieved the great effect of dengue clinical management and dengue control.

Keywords: dengue control, integrated control strategies, clinical management, NS1

Procedia PDF Downloads 246
668 Antimicrobial Activity of Igusa and the Application to Foam Materials for Food Industry

Authors: I. Nanako, Mariko Era, Hiroshi Morita

Abstract:

Objectives: Japanese uses TATAMI rather than flooring at home. Igusa ( Juncus effuses var. decipiens ), which is commonly known in the forms of TATAMI. Juncus spp. grow at a relatively high humidity area (Japan, China and Southeast Asia ). Yatsushiro region in the southern part of Kumamoto prefecture is major produing area of Igusa. Igusa found to have honeycomb structure and was also shown to have the ability to control humidity. And Igusa has been used as a medicinal herb for diuretic and antiphlogistic agent. In previous study, we investigated antimicrobial effects of Igusa, and showed high antimicrobial activity against food poisoning bacteria. Therefore, the food trays blended Igusa can be kept clean by antimicrobial activity of Igusa. We focus on ‘Igusa foam materials’. In this study, we investigated the antibacterial and antifungal activity of Igusa, and new application to foam materials for food industry. Materials and method: We used Igusa foam materials (3 × 3 × 3 cm) as a sample. We set about fifteen types of samples combined with a commercial antibacterial agent A, a commercial antibacterial agent B, potassium laurate (C12K) and a commercial antifungal agent C, a commercial antifungal agent D and a commercial antifungal agent E. We selected four bacteria strains (Escherichia coli NBRC 3972, Staphylococus aureus NBRC 12732, Salmonella typhimurium NBRC 13245, Bacillus subtilis NBRC 3335 ) and three fungus strains (Penicillium pinophilum NBRC 6345, Cladosporium cladosporioides NBRC 30314, Aspergillus oryzae NBRC 5238 ). The fungus was cultured at 30 °C on Igusa foam materials after inoculation of the fungus for fourteen days. The bacteria was cultured at 30 °C on Igusa foam materials after inoculation of the bacteria for three days. And the Igusa foam materials were washed with 10 mL normal saline after three days. The normal saline washed Igusa foam materials plated the NA medium. After, It was cultured at 30 °C and used colony counting method. Result and Conclusion: The fifteen types of sample of Igusa foam materials had antifungal activity against C. cladosporioides, A. oryzae and P. pinophilum for fourteen days. The four types of sample contained potassium laurate and antibacterial agent A, sample contained antibacterial agent B and antifungal agent D, sample contained A and antifungal agent E, sample contained B and E had antibacterial activity against B. subtilis. The three types of sample contained potassium laurate and A, sample contained B and D, sample contained A and E had antibacterial activity against S. typhimurium. The five types of sample contained potassium laurate and A, sample contained B and D, sample contained A and E, sample contained B and E, sample contained B and antifungal agent C had antibacterial activity against E. coli and S. aureus. These results indicate that Igusa of Igusa foam materials had high antifungal activity. In addition, Igusa foam materials combined with a commercial antibacterial agent had antibacterial activity. In the future, we consider that use of Igusa foam materials may be spread from food industry.

Keywords: antibacterial, antifungal, foam materials, Igusa

Procedia PDF Downloads 219
667 Enhanced Field Emission from Plasma Treated Graphene and 2D Layered Hybrids

Authors: R. Khare, R. V. Gelamo, M. A. More, D. J. Late, Chandra Sekhar Rout

Abstract:

Graphene emerges out as a promising material for various applications ranging from complementary integrated circuits to optically transparent electrode for displays and sensors. The excellent conductivity and atomic sharp edges of unique two-dimensional structure makes graphene a propitious field emitter. Graphene analogues of other 2D layered materials have emerged in material science and nanotechnology due to the enriched physics and novel enhanced properties they present. There are several advantages of using 2D nanomaterials in field emission based devices, including a thickness of only a few atomic layers, high aspect ratio (the ratio of lateral size to sheet thickness), excellent electrical properties, extraordinary mechanical strength and ease of synthesis. Furthermore, the presence of edges can enhance the tunneling probability for the electrons in layered nanomaterials similar to that seen in nanotubes. Here we report electron emission properties of multilayer graphene and effect of plasma (CO2, O2, Ar and N2) treatment. The plasma treated multilayer graphene shows an enhanced field emission behavior with a low turn on field of 0.18 V/μm and high emission current density of 1.89 mA/cm2 at an applied field of 0.35 V/μm. Further, we report the field emission studies of layered WS2/RGO and SnS2/RGO composites. The turn on field required to draw a field emission current density of 1μA/cm2 is found to be 3.5, 2.3 and 2 V/μm for WS2, RGO and the WS2/RGO composite respectively. The enhanced field emission behavior observed for the WS2/RGO nanocomposite is attributed to a high field enhancement factor of 2978, which is associated with the surface protrusions of the single-to-few layer thick sheets of the nanocomposite. The highest current density of ~800 µA/cm2 is drawn at an applied field of 4.1 V/μm from a few layers of the WS2/RGO nanocomposite. Furthermore, first-principles density functional calculations suggest that the enhanced field emission may also be due to an overlap of the electronic structures of WS2 and RGO, where graphene-like states are dumped in the region of the WS2 fundamental gap. Similarly, the turn on field required to draw an emission current density of 1µA/cm2 is significantly low (almost half the value) for the SnS2/RGO nanocomposite (2.65 V/µm) compared to pristine SnS2 (4.8 V/µm) nanosheets. The field enhancement factor β (~3200 for SnS2 and ~3700 for SnS2/RGO composite) was calculated from Fowler-Nordheim (FN) plots and indicates emission from the nanometric geometry of the emitter. The field emission current versus time plot shows overall good emission stability for the SnS2/RGO emitter. The DFT calculations reveal that the enhanced field emission properties of SnS2/RGO composites are because of a substantial lowering of work function of SnS2 when supported by graphene, which is in response to p-type doping of the graphene substrate. Graphene and 2D analogue materials emerge as a potential candidate for future field emission applications.

Keywords: graphene, layered material, field emission, plasma, doping

Procedia PDF Downloads 344
666 Examining Historically Defined Periods in Autobiographical Memories for Transitional Events

Authors: Khadeeja Munawar, Shamsul Haque

Abstract:

We examined the plausibility of transition theory suggesting that memories of transitional events, which give rise to a significant and persistent change in the fabric of daily life, are organized around the historically defined autobiographical periods (H-DAPs). 141 Pakistani older adults retrieved 10 autobiographical memories (AMs) each to 10 cue words. As the history of Pakistan is dominated by various political and nationwide transitional events, it was expected that the participants would recall memories with H-DAPs references. The content analysis revealed that 0.7% of memories had H-DAP references and 0.4% memories mentioned major transitional events such as War/Natural Disaster. There was a vivid reminiscence bump between 10 - 20 years of age in lifespan distribution of AMs. There were 67.9% social-focused AMs. Significantly more self-focused memories were reported by individuals who endorsed themselves as conservatives. Only a few H-DAPs were reported, although the history of Pakistan was dominated by numerous political, historical and nationwide transitional events. Memories within and outside of the bump period were mostly positive. The participants rarely used historical/political or nationwide significant events or periods to date the memories elicited. The intense and nationwide (as well as region-wise) significant historical/political events spawned across decades in the lives of participants of the present study but these events did not produce H-DAPs. The findings contradicted the previous studies on H-DAPs and transition theory. The dominance of social-focused AMs in the present study is in line with the past studies comparing the memories of collectivist and individualist cultures (i.e., European Americans vs. Asian, African and Latin-American cultures). The past empirical evidence shows that conservative values and beliefs are adopted as a coping strategy to feel secure in the face of danger when future is dominated with uncertainty and to connect to likeminded others. In the present study, conservative political ideology is somehow assisting the participants in living a stable life midst of their complex social worlds. The reminiscence bump, as well as dominance of positive memories within and outside the bump period, are in line with the narrative/identity account which states that the events and experiences during adolescence and early adulthood assimilate into a person’s lifelong narratives. Hence these events are used as identity markers and are more easily recalled later in life. Also, according to socioemotional theory and the positivity effect, the participants evaluated past events more positively as they grow up and the intensity of negative emotions decreased with time.

Keywords: autobiographical memory, historically defined autobiographical periods, narrative/identity account, Pakistan, reminiscence bump, SMS framework, transition theory

Procedia PDF Downloads 207
665 Accelerating Personalization Using Digital Tools to Drive Circular Fashion

Authors: Shamini Dhana, G. Subrahmanya VRK Rao

Abstract:

The fashion industry is advancing towards a mindset of zero waste, personalization, creativity, and circularity. The trend of upcycling clothing and materials into personalized fashion is being demanded by the next generation. There is a need for a digital tool to accelerate the process towards mass customization. Dhana’s D/Sphere fashion technology platform uses digital tools to accelerate upcycling. In essence, advanced fashion garments can be designed and developed via reuse, repurposing, recreating activities, and using existing fabric and circulating materials. The D/Sphere platform has the following objectives: to provide (1) An opportunity to develop modern fashion using existing, finished materials and clothing without chemicals or water consumption; (2) The potential for an everyday customer and designer to use the medium of fashion for creative expression; (3) A solution to address the global textile waste generated by pre- and post-consumer fashion; (4) A solution to reduce carbon emissions, water, and energy consumption with the participation of all stakeholders; (5) An opportunity for brands, manufacturers, retailers to work towards zero-waste designs and as an alternative revenue stream. Other benefits of this alternative approach include sustainability metrics, trend prediction, facilitation of disassembly and remanufacture deep learning, and hyperheuristics for high accuracy. A design tool for mass personalization and customization utilizing existing circulating materials and deadstock, targeted to fashion stakeholders will lower environmental costs, increase revenues through up to date upcycled apparel, produce less textile waste during the cut-sew-stitch process, and provide a real design solution for the end customer to be part of circular fashion. The broader impact of this technology will result in a different mindset to circular fashion, increase the value of the product through multiple life cycles, find alternatives towards zero waste, and reduce the textile waste that ends up in landfills. This technology platform will be of interest to brands and companies that have the responsibility to reduce their environmental impact and contribution to climate change as it pertains to the fashion and apparel industry. Today, over 70% of the $3 trillion fashion and apparel industry ends up in landfills. To this extent, the industry needs such alternative techniques to both address global textile waste as well as provide an opportunity to include all stakeholders and drive circular fashion with new personalized products. This type of modern systems thinking is currently being explored around the world by the private sector, organizations, research institutions, and governments. This technological innovation using digital tools has the potential to revolutionize the way we look at communication, capabilities, and collaborative opportunities amongst stakeholders in the development of new personalized and customized products, as well as its positive impacts on society, our environment, and global climate change.

Keywords: circular fashion, deep learning, digital technology platform, personalization

Procedia PDF Downloads 39
664 The Relationship between Body Fat Percent and Metabolic Syndrome Indices in Childhood Morbid Obesity

Authors: Mustafa Metin Donma

Abstract:

Metabolic syndrome (MetS) is characterized by a series of biochemical, physiological and anthropometric indicators and is a life-threatening health problem due to its close association with chronic diseases such as diabetes mellitus, hypertension, cancer and cardiovascular diseases. The syndrome deserves great interest both in adults and children. Central obesity is the indispensable component of MetS. Particularly, children, who are morbidly obese have a great tendency to develop the disease, because they are under the threat in their future lives. Preventive measures at this stage should be considered. For this, investigators seek for an informative scale or an index for the purpose. So far, several, but not many suggestions come into the stage. However, the diagnostic decision is not so easy and may not be complete particularly in the pediatric population. The aim of the study was to develop a MetS index capable of predicting MetS, while children are at the morbid obesity stage. This study was performed on morbid obese (MO) children, which were divided into two groups. Morbid obese children, who do not possess MetS criteria comprised the first group (n=44). The second group was composed of children (n=42) with MetS diagnosis. Parents were informed about the signed consent forms, which are required for the participation of their children in the study. The approval of the study protocol was taken from the institutional ethics committee of Tekirdag Namik Kemal University. Helsinki Declaration was accepted prior to and during the study. Anthropometric measurements including weight, height, waist circumference (WC), hip C, head C, neck C, biochemical tests including fasting blood glucose (FBG), insulin (INS), triglycerides (TRG), high density lipoprotein cholesterol (HDL-C) and blood pressure measurements (systolic (SBP) and diastolic (DBP)) were performed. Body fat percentage (BFP) values were determined by TANITA’s Bioelectrical Impedance Analysis technology. Body mass index and MetS indices were calculated. The equations for MetS index (MetSI) and advanced Donma MetS index (ADMI) were [(INS/FBG)/(HDL-C/TRG)]*100 and MetSI*[(SBP+DBP/Height)], respectively. Descriptive statistics including median values, compare means tests, correlation-regression analysis were performed within the scope of data evaluation using the statistical package program, SPSS. Statistically significant mean differences were determined by a p value smaller than 0.05. Median values for MetSI and ADMI in MO (MetS-) and MO (MetS+) groups were calculated as (25.9 and 36.5) and (74.0 and 106.1), respectively. Corresponding mean±SD values for BFPs were 35.9±7.1 and 38.2±7.7 in groups. Correlation analysis of these two indices with corresponding general BFP values exhibited significant association with ADMI, close to significance with MetSI in MO group. Any significant correlation was found with neither of the indices in MetS group. In conclusion, important associations observed with MetS indices in MO group were quite meaningful. The presence of these associations in MO group was important for showing the tendency towards the development of MetS in MO (MetS-) participants. The other index, ADMI, was more helpful for predictive purpose.

Keywords: body fat percentage, child, index, metabolic syndrome, obesity

Procedia PDF Downloads 45
663 Fabrication of High Energy Hybrid Capacitors from Biomass Waste-Derived Activated Carbon

Authors: Makhan Maharjan, Mani Ulaganathan, Vanchiappan Aravindan, Srinivasan Madhavi, Jing-Yuan Wang, Tuti Mariana Lim

Abstract:

There is great interest to exploit sustainable, low-cost, renewable resources as carbon precursors for energy storage applications. Research on development of energy storage devices has been growing rapidly due to mismatch in power supply and demand from renewable energy sources This paper reported the synthesis of porous activated carbon from biomass waste and evaluated its performance in supercapicators. In this work, we employed orange peel (waste material) as the starting material and synthesized activated carbon by pyrolysis of KOH impregnated orange peel char at 800 °C in argon atmosphere. The resultant orange peel-derived activated carbon (OP-AC) exhibited a high BET surface area of 1,901 m2 g-1, which is the highest surface area so far reported for the orange peel. The pore size distribution (PSD) curve exhibits the pores centered at 11.26 Å pore width, suggesting dominant microporosity. The OP-AC was studied as positive electrode in combination with different negative electrode materials, such as pre-lithiated graphite (LiC6) and Li4Ti5O12 for making different hybrid capacitors. The lithium ion capacitor (LIC) fabricated using OP-AC with pre-lithiated graphite delivered a high energy density of ~106 Wh kg–1. The energy density for OP-AC||Li4Ti5O12 capacitor was ~35 Wh kg–1. For comparison purpose, configuration of OP-AC||OP-AC capacitors were studied in both aqueous (1M H2SO4) and organic (1M LiPF6 in EC-DMC) electrolytes, which delivered the energy density of 6.6 Wh kg-1 and 16.3 Wh kg-1, respectively. The cycling retentions obtained at current density of 1 A g–1 were ~85.8, ~87.0 ~82.2 and ~58.8% after 2500 cycles for OP-AC||OP-AC (aqueous), OP-AC||OP-AC (organic), OP-AC||Li4Ti5O12 and OP-AC||LiC6 configurations, respectively. In addition, characterization studies were performed by elemental and proximate composition, thermogravimetry, field emission-scanning electron microscopy, Raman spectra, X-ray diffraction (XRD) pattern, Fourier transform-infrared, X-ray photoelectron spectroscopy (XPS) and N2 sorption isotherms. The morphological features from FE-SEM exhibited well-developed porous structures. Two typical broad peaks observed in the XRD framework of the synthesized carbon implies amorphous graphitic structure. The ratio of 0.86 for ID/IG in Raman spectra infers high degree of graphitization in the sample. The band spectra of C 1s in XPS display the well resolved peaks related to carbon atoms in various chemical environments; for instances, the characteristics binding energies appeared at ~283.83, ~284.83, ~286.13, ~288.56, and ~290.70 eV which correspond to sp2 -graphitic C, sp3 -graphitic C, C-O, C=O and π-π*, respectively. Characterization studies revealed the synthesized carbon to be promising electrode material towards the application for energy storage devices. The findings opened up the possibility of developing high energy LICs from abundant, low-cost, renewable biomass waste.

Keywords: lithium-ion capacitors, orange peel, pre-lithiated graphite, supercapacitors

Procedia PDF Downloads 214
662 An Assessment of Involuntary Migration in India: Understanding Issues and Challenges

Authors: Rajni Singh, Rakesh Mishra, Mukunda Upadhyay

Abstract:

India is among the nations born out of partition that led to one of the greatest forced migrations that marked the past century. The Indian subcontinent got partitioned into two nation-states, namely India and Pakistan. This led to an unexampled mass displacement of people accounting for about 20 million in the subcontinent as a whole. This exemplifies the socio-political version of displacement, but there are other identified reasons leading to human displacement viz., natural calamities, development projects and people-trafficking and smuggling. Although forced migrations are rare in incidence, they are mostly region-specific and a very less percentage of population appears to be affected by it. However, when this percentage is transcripted in terms of volume, the real impact created by such migration can be realized. Forced migration is thus an issue related to the lives of many people and requires to be addressed with proper intervention. Forced or involuntary migration decimates peoples' assets while taking from them their most basic resources and makes them migrate without planning and intention. This in most cases proves to be a burden on the destination resources. Thus, the question related to their security concerns arise profoundly with regard to the protection and safeguards to these migrants who need help at the place of destination. This brings the human security dimension of forced migration into picture. The present study is an analysis of a sample of 1501 persons by NSSO in India (National Sample Survey Organisation), which identifies three reasons for forced migration- natural disaster, social/political problem and displacement by development projects. It was observed that, of the total forced migrants, about 4/5th comprised of the internally displaced persons. However, there was a huge inflow of such migrants to the country from across the borders also, the major contributing countries being Bangladesh, Pakistan, Sri Lanka, Gulf countries and Nepal. Among the three reasons for involuntary migration, social and political problem is the most prominent in displacing huge masses of population; it is also the reason where the share of international migrants to that of internally displaced is higher compared to the other two factors /reasons. Second to political and social problems, natural calamities displaced a high portion of the involuntary migrants. The present paper examines the factors which increase people's vulnerability to forced migration. On perusing the background characteristics of the migrants it was seen that those who were economically weak and socially fragile are more susceptible to migration. Therefore, getting an insight about this fragile group of society is required so that government policies can benefit these in the most efficient and targeted manner.

Keywords: involuntary migration, displacement, natural disaster, social and political problem

Procedia PDF Downloads 332
661 The Impact of a Leadership Change on Individuals' Behaviour and Incentives: Evidence from the Top Tier Italian Football League

Authors: Kaori Narita, Juan de Dios Tena Horrillo, Claudio Detotto

Abstract:

Decisions on replacement of leaders are of significance and high prevalence in any organization, and concerns many of its stakeholders, whether it is a leader in a political party or a CEO of a firm, as indicated by high media coverage of such events. This merits an investigation into the consequences and implications of a leadership change on the performances and behavior of organizations and their workers. Sport economics provides a fruitful field to explore these issues due to the high frequencies of managerial changes in professional sports clubs and the transparency and regularity of observations of team performance and players’ abilities. Much of the existing research on managerial change focuses on how this affects the performance of an organization. However, there is scarcely attention paid to the consequences of such events on the behavior of individuals within the organization. Changes in behavior and attitudes of a group of workers due to a managerial change could be of great interest in management science, psychology, and operational research. On the other hand, these changes cannot be observed in the final outcome of the organization, as this is affected by many other unobserved shocks, for example, the stress level of workers with the need to deal with a difficult situation. To fill this gap, this study shows the first attempt to evaluate the impact of managerial change on players’ behaviors such as attack intensity, aggressiveness, and efforts. The data used in this study is from the top tier Italian football league (“Serie A”), where an average of 13 within season replacements of head coaches were observed over the period of seasons from 2000/2001 to 2017/18. The preliminary estimation employs Pooled Ordinary Least Square (POLS) and club-season Fixed Effect (FE) in order to assess the marginal effect of having a new manager on the number of shots, corners and red/yellow cards after controlling for a home-field advantage, ex ante abilities and current positions in the league of a team and their opponent. The results from this preliminary estimation suggest that the teams do not show a significant difference in their behaviors before and after the managerial change. To build on these preliminary results, other methods, including propensity score matching and non-linear model estimates, will be used. Moreover, the study will further investigate these issues by considering other measurements of attack intensity, aggressiveness, and efforts, such as possessions, a number of fouls and the athletic performance of players, respectively. Finally, the study is going to investigate whether these results vary over the characteristics of a new head coach, for example, their age and experience as a manager and a player. Thus far, this study suggests that certain behaviours of individuals in an organisation are not immediately affected by a change in leadership. To confirm this preliminary finding and lead to a more solid conclusion, further investigation will be conducted in the aforementioned manner, and the results will be elaborated in the conference.

Keywords: behaviour, effort, manager characteristics, managerial change, sport economics

Procedia PDF Downloads 113
660 Examining Smallholder Farmers’ Perceptions of Climate Change and Barriers to Strategic Adaptation in Todee District, Liberia

Authors: Joe Dorbor Wuokolo

Abstract:

Thousands of smallholder farmers in Todee District, Montserrado county, are currently vulnerable to the negative impact of climate change. The district, which is the agricultural hot spot for the county, is faced with unfavorable changes in the daily temperature due to climate change. Farmers in the district have observed a dramatic change in the ratio of rainfall to sunshine, which has caused a chilling effect on their crop yields. However, there is a lack of documentation regarding how farmers perceive and respond to these changes and challenges. A study was conducted in the region to examine the perceptions of smallholder farmers regarding the negative impact of climate change, the adaptation strategies practice, and the barriers that hinder the process of advancing adaptation strategy. On purpose, a sample of 41 respondents from five towns was selected, including five town chiefs, five youth leaders, five women leaders, and sixteen community members. Women and youth leaders were specifically chosen to provide gender balance and enhance the quality of the investigation. Additionally, to validate the barriers farmers face during adaptation to climate change, this study interviewed eight experts from local and international organizations and government ministries and agencies involved in climate change and agricultural programs on what they perceived as the major barrier in both local and national level that impede farmers adaptation to climate change impact. SPSS was used to code the data, and descriptive statistics were used to analyze the data. The weighted average index (WAI) was used to rank adaptation strategies and the perceived importance of adaptation practices among farmers. On a scale from 0 to 3, 0 indicates the least important technique, and 3 indicates the most effective technique. In addition, the Problem Confrontation Index (PCI) was used to rank the barriers that prevented farmers from implementing adaptation measures. According to the findings, approximately 60% of all respondents considered the use of irrigation systems to be the most effective adaptation strategy, with drought-resistant varieties making up 30% of the total. Additionally, 80% of respondents placed a high value on drought-resistant varieties, while 63% percent placed it on irrigation practices. In addition, 78% of farmers ranked and indicated that unpredictability of the weather is the most significant barrier to their adaptation strategies, followed by the high cost of farm inputs and lack of access to financing facilities. 80% of respondents believe that the long-term changes in precipitation (rainfall) and temperature (hotness) are accelerating. This suggests that decision-makers should adopt policies and increase the capacity of smallholder farmers to adapt to the negative impact of climate change in order to ensure sustainable food production.

Keywords: adaptation strategies, climate change, farmers’ perception, smallholder farmers

Procedia PDF Downloads 69
659 Making Haste Slowly: South Africa's Transition from a Medical to a Social Model regarding Persons with Disabilities

Authors: Leoni Van Der Merwe

Abstract:

Historically, in South Africa, disability has been viewed as a dilemma of the individual. The discourse surrounding the definition of disability and applicable theories are as fluid as the differing needs of persons with disabilities within society. In 1997, the Office of the Deputy President published the White Paper on the Integrated National Disability Strategy (WPINDS) which sought to integrate disability issues in all governmental development strategies, planning and programs as well as to solidify the South African government’s stance that disability was to be considered according to the social model and not the, previously utilized, medical model of disability. The models of disability are conceptual frameworks for understanding disability and can provide some insight into why certain attitudes exist and how they are reinforced in society. Although the WPINDS was regarded as a critical milestone in the history of the disability rights struggle in South Africa; it has taken approximately twenty years for the publication of a similar document taking into account South Africa’s changing social, economic, political and technological dispensation. December 2015 marked the approval of the White Paper on the Rights of Persons with Disabilities (WPRPD) which seeks to update the WPINDS, integrate principles contained in international law instruments and endorse a mainstreaming trajectory for realizing the rights of persons with disabilities. While the WPINDS and the WPRPD were published two decades apart, both documents contain an emphasis on a transition from the medical model to the social model. Whereas, the medical model presupposes that disability is mainly a health and welfare matter and is focused on an individualistic and dependency-based approach; the social model requires a paradigm shift in the manner in which disability is constructed so as to highlight the shortcomings of society in respect of disability and to bring to the fore the capabilities of persons with disabilities. The social model has led to unmatched success in changing the perceptions surrounding disability. This article seeks to investigate the progress made in the implementation of the social model in South Africa by taking into account the effect of the diverse political and cultural landscape in promoting the historically entrenched medical model and the rise of disability activism prior to the new democratic dispensation as well as legislation, case law, policy documents and barriers in respect of persons with disabilities that are pervasive in South African society. The research paper will conclude that although numerous interventions have been identified and implemented to promote the consideration of disability within a social construct in South Africa, such interventions require increased national and international collaboration, resources and pace to ensure that the efforts made lead to sustainable results. For persons with disabilities, what remains to be seen is whether the proliferation of activism by interest groups, social awareness as well as the development of policy documents, legislation and case law will serve as the impetus to dissipate the view that disability is burden to be carried solely on the shoulders of the person with the disability.

Keywords: disability, medical model, social model, societal barriers, South Africa

Procedia PDF Downloads 358
658 A Study of the Prevalence of Trichinellosis in Domestic and Wild Animals for the Region of Sofia, Bulgaria

Authors: Valeria Dilcheva, Svetlozara Petkova, Ivelin Vladov

Abstract:

Nemathodes of the genus Trichinella are zoonotic parasites with a cosmopolitan distribution. More than 100 species of mammals, birds and reptiles are involved in the natural cycle of this nematode. At present, T. spiralis, T. pseudospiralis, and T. britovi have been found in Bulgaria. The existence of natural wildlife and domestic reservoirs of Trichinella spp. can be a serious threat to human health. Three trichinella isolates caused human trichinella infection outbreaks from three regions of Sofia City Province were used for the research: sample No. 1 - Ratus norvegicus, sample No. 2 – domestic pig (Sus scrofa domestica), sample No. 3 - domestic pig (Sus scrofa domestica). Trichinella larvae of the studied species were isolated via digestive method (pepsin, hydrochloric acid, water) at 37ºC by standard procedure and were determined by gender (male and female) based on their morphological characteristics. As a reference trichinella species were used: T. spiralis, T. pseudospiralis, T. nativa and T. britovi. Single male and female larvae of the three isolates were crossed with single male and female larvae of the reference trichinella species as well as reciprocally. As a result of cross-breeding, offspring of muscular larvae with T. spiralis and T. britovi were obtained, while in experiments with T. pseudospiralis and T. nativa, trichinella larvae were not found in the laboratory mice. The results obtained in the control groups indicate that the trichinella larvae used from the isolates and the four trichinella species are infective. Also, the infective ability of the F1 offspring from the successful cross-breeding between isolates and reference species was investigated. Through the data obtained in the experiment was found that isolates No. 1 and No. 2 belong to the species T. spiralis, and isolate No. 3 belongs to the species T. britovi. The results were confirmed by PCR and real-time PCR analysis. Thus the presence and circulation of the species T. spiralis and T. britovi in Bulgaria was confirmed. Probably the rodents (rats) are involved in the distribution of T. spiralis in urban environment. The species T. britovi found in a domestic pig speaks of some contact with wild animals for which T. britovi is characteristic. The probable reason is that a large number of farmers in Bulgaria practice the free-range breeding of domestic pigs. Part of the farmers also used as food for domestic pigs waste products from the game (foxes, jackals, bears, wolves) and probably thus the infection was obtained. The distribution range of trichinella species in Bulgaria is not strictly outlined. It is believed that T. spiralis is most common in domestic animals and T. britovi and T. pseudospiralis are characteristic of wildlife. To answer the question whether wild and synanthropic animals are infected with the same or different trichinella species, which species predominate in nature and what their distribution among different hosts is, further research is required.

Keywords: cross-breeding, Sofia, trichinellosis, Trichinella britovi, Trichinella spiralis

Procedia PDF Downloads 163
657 Sensitivity Improvement of Optical Ring Resonator for Strain Analysis with the Direction of Strain Recognition Possibility

Authors: Tayebeh Sahraeibelverdi, Ahmad Shirazi Hadi Veladi, Mazdak Radmalekshah

Abstract:

Optical sensors became attractive due to preciseness, low power consumption, and intrinsic electromagnetic interference-free characteristic. Among the waveguide optical sensors, cavity-based ones attended for the high Q-factor. Micro ring resonators as a potential platform have been investigated for various applications as biosensors to pressure sensors thanks to their sensitive ring structure responding to any small change in the refractive index. Furthermore, these small micron size structures can come in an array, bringing the opportunity to have any of the resonance in a specific wavelength and be addressed in this way. Another exciting application is applying a strain to the ring and making them an optical strain gauge where the traditional ones are based on the piezoelectric material. Making them in arrays needs electrical wiring and about fifty times bigger in size. Any physical element that impacts the waveguide cross-section, Waveguide elastic-optic property change, or ring circumference can play a role. In comparison, ring size change has a larger effect than others. Here an engineered ring structure is investigated to study the strain effect on the ring resonance wavelength shift and its potential for more sensitive strain devices. At the same time, these devices can measure any strain by mounting on the surface of interest. The idea is to change the" O" shape ring to a "C" shape ring with a small opening starting from 2π/360 or one degree. We used the Mode solution of Lumbrical software to investigate the effect of changing the ring's opening and the shift induced by applied strain. The designed ring radius is a three Micron silicon on isolator ring which can be fabricated by standard complementary metal-oxide-semiconductor (CMOS) micromachining. The measured wavelength shifts from1-degree opening of the ring to a 6-degree opening have been investigated. Opening the ring for 1-degree affects the ring's quality factor from 3000 to 300, showing an order of magnitude Q-factor reduction. Assuming a strain making the ring-opening from 1 degree to 6 degrees, our simulation results showing negligible Q-factor reduction from 300 to 280. A ring resonator quality factor can reach up to 108 where an order of magnitude reduction is negligible. The resonance wavelength shift showed a blue shift and was obtained to be 1581, 1579,1578,1575nm for 1-, 2-, 4- and 6-degree ring-opening, respectively. This design can find the direction of the strain-induced by applying the opening on different parts of the ring. Moreover, by addressing the specified wavelength, we can precisely find the direction. We can open a significant opportunity to find cracks and any surface mechanical property very specifically and precisely. This idea can be implemented on polymer ring resonators while they can come with a flexible substrate and can be very sensitive to any strain making the two ends of the ring in the slit part come closer or further.

Keywords: optical ring resonator, strain gauge, strain sensor, surface mechanical property analysis

Procedia PDF Downloads 105