Search results for: peak current reduction

Authors: Foo Shen Hwang, Thomas Confrey, Stephen Scully, Barry Flannery

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Thermal characterization plays an important role in battery pack design. Lithium-ion batteries have to be maintained between 15-35 °C to operate optimally. Heat is generated (Q) internally within the batteries during both the charging and discharging phases. This can be quantified using several standard methods. The most common method of calculating the batteries heat generation is through the addition of both the joule heating effects and the entropic changes across the battery. In addition, such values can be derived by identifying the open-circuit voltage (OCV), nominal voltage (V), operating current (I), battery temperature (T) and the rate of change of the open-circuit voltage in relation to temperature (dOCV/dT). This paper focuses on experimental characterization and comparative modelling of the heat generation rate (Q) across several current discharge rates (0.5C, 1C, and 1.5C) of a 18650 cell. The analysis is conducted utilizing several non-linear mathematical functions methods, including polynomial, exponential, and power models. Parameter fitting is carried out over the respective function orders; polynomial (n = 3~7), exponential (n = 2) and power function. The generated parameter fitting functions are then used as heat source functions in a 3-D computational fluid dynamics (CFD) solver under natural convection conditions. Generated temperature profiles are analyzed for errors based on experimental discharge tests, conducted at standard room temperature (25°C). Initial experimental results display low deviation between both experimental and CFD temperature plots. As such, the heat generation function formulated could be easier utilized for larger battery applications than other methods available.

Keywords: computational fluid dynamics, curve fitting, lithium-ion battery, voltage drop

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Authors: Frederic Schenker, Jonathan J. Hendriks, Gianluca Nicchiotti

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In a product industrialization perspective, the end-product shall always be at the peak of technological advancement and developed in the shortest time possible. Thus, the constant growth of complexity and a shorter time-to-market calls for important changes on both the technical and business level. Undeniably, the common understanding of the system is beclouded by its complexity which leads to the communication gap between the engineers and the sale department. This communication link is therefore important to maintain and increase the information exchange between departments to ensure a punctual and flawless delivery to the end customer. This evolution brings engineers to reason with more hindsight and plan ahead. In this sense, they use new viewpoints to represent the data and to express the model deliverables in an understandable way that the different stakeholder may identify their needs and ideas. This article focuses on the usage of Model-Based System Engineering (MBSE) in a perspective of system industrialization and reconnect the engineering with the sales team. The modeling method used and presented in this paper concentrates on displaying as closely as possible the needs of the customer. Firstly, by providing a technical solution to the sales team to help them elaborate commercial offers without omitting technicalities. Secondly, the model simulates between a vast number of possibilities across a wide range of components. It becomes a dynamic tool for powerful analysis and optimizations. Thus, the model is no longer a technical tool for the engineers, but a way to maintain and solidify the communication between departments using different views of the model. The MBSE contribution to cost optimization during New Product Introduction (NPI) activities is made explicit through the illustration of a case study describing the support provided by system models to architectural choices during the industrialization of a novel optical sensor.

Keywords: analytical model, architecture comparison, MBSE, product industrialization, SysML, system thinking

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Authors: André Furtado, Rafael Mineiro, Isabel Gonçalves, Cecília Santos, Telma Quintela

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The development of therapies for central nervous system (CNS) disorders is one of the biggest challenges of current pharmacology, given the unique features of brain barriers, which limit drug delivery. Efflux transporters (ABC transporters) expressed at the blood-cerebrospinal fluid barrier (BCSFB), are the main obstacles for the delivery of therapeutic compounds into the CNS, compromising the effective treatment of brain cancer, brain metastasis from peripheral cancers, or even neurodegenerative disorders. It is thus extremely important to understand the regulation of these transporters for reducing their expression while treating a brain disorder or choosing the most appropriate conditions for drug administration. Based on the fact that the BCSFB have fine-tuned biological rhythms, studying the circadian variation of drug transport processes is critical for choosing the most appropriate time of the day for drug administration. In our study, using an in vitro model of the BCSFB, we characterized the circadian transport profile of methotrexate (MTX) and donepezil (DNPZ), two drugs involved in the treatment of cancer and Alzheimer’s Disease symptoms, respectively. We found that MTX is transported across the basal and apical membranes of the BCSFB in a circadian way. The circadian pattern of an ABC transporter, Abcc4, might be partially responsible for MTX circadian transport. Furthermore, regarding the DNPZ transport study, we observed that the regulation of Abcg2 expression by the circadian rhythm will impact the circadian-dependent transport of DNPZ across the BCSFB. Overall, our results will contribute to the current knowledge on brain pharmacoresistance at the BCSFB by disclosing how circadian rhythms control drug delivery to the brain, setting the grounds for a potential application of chronotherapy to brain diseases to enhance the efficacy of medications and minimize their side effects.

Keywords: blood-cerebrospinal fluid barrier, ABC transporters, drug transport, chronotherapy

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Authors: Rafia Akbar

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This paper assesses different Energy Efficiency Measures (EEMs) and their impact on energy consumption and carbon footprint of an educational building located in Islamabad. A base case was first developed in accordance with typical construction practices in Pakistan. Several EEMs were separately applied to the baseline design to quantify their impact on operational energy reduction of the building and the resultant carbon emissions. Results indicate that by applying these measures, there is a potential to reduce energy consumption up to 49% as compared to the base case. It was observed that energy efficient ceiling fans and lights, insulation of the walls and roof and an efficient air conditioning system for the building can provide significant energy savings. The results further indicate that the initial investment cost of these energy efficiency measures can be recovered within 6 to 7 years of building’s service life.

Keywords: CO2 savings, educational building, energy efficiency measures, payback period

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Authors: A. Boumedine, K. Benfriha, S. Lecheb

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Manufacturing methods for products and structures made of composite materials reduce the number of parts and integrate technical functions, this advantage of composite materials leads to a lot of innovation but also to a reduction of costs and a gain in quality. A material has attributes: its density, it’s resistance, it’s cost, it’s resistance to corrosion. For the design of a product, a certain profile of these attributes is required: low density, resistance removed, low cost. The problem is then to identify this attribute profile and to compare it with those of the materials, in order to find the one that comes closest. The aim of this work is to demonstrate the feasibility of characterizing a mini turbine made of 3D printed fiber-filled composite material by the process of additive manufacturing, then compare the performance of the alloy turbine with the composite turbine according to the results of the simulation by Abaqus software.

Keywords: additive manufacturing, composite materials, design, 3D printer, turbine

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Authors: Loujaina Abdelwahed

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Debt relief granted to low-and middle-income countries effectively provides additional funds for governments that can be used to increase public investment on poverty-reducing services to alleviate poverty and boost economic growth. However, little is known about the extent to which the poor benefit from the increased public investment. This study aims to assess the impact of debt relief granted through multiple initiatives during the 1990s on poverty reduction. In particular, it assesses the impact on the level, depth and severity of poverty in 76 low-and middle income countries over the period 1990-2011. Debt relief is found to have a significant impact on reducing the level, the depth and the severity of poverty. Analysis of the different types of debt relief reveals that debt service relief reduces poverty, whereas debt principle relief does not have a significant impact.

Keywords: debt relief, developing countries, HIPC, poverty, system GMM estimator

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Authors: K. Jankowski, M. Pawlikowski, A. Makuch, K. Skalski

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Depth-sensing indentation (DSI) or nanoindentation is becoming a more and more popular method of measuring mechanical properties of various materials and tissues at a micro-scale. This technique allows measurements without complicated sample preparation procedures which makes this method very useful. As a result of measurement force and displacement of the intender are obtained. It is also possible to determine three measures of hardness i.e. Martens hardness (HM), nanohardness (HIT), Vickers hardness (HV) and Young modulus EIT. In this work trabecular bone mechanical properties were investigated. The bone samples were harvested from human femoral heads during hip replacement surgery. Patients were of different age, sexes and stages of tissue degeneration caused by osteoarthritis. The specimens were divided into three groups. Each group contained samples harvested from patients of different range of age. All samples were investigated with the same measurement conditions. The maximum load was Pmax=500 mN and the loading rate was 500 mN/min. The tests were held without hold at the peak force. The tests were conducted with indenter Vickers tip and spherical tip of the diameter 0.2 mm. Each trabecular bone sample was tested 7 times in a close area of the same trabecula. The measured loading P as a function of indentation depth allowed to obtain hysteresis loop and HM, HIT, HV, EIT. Results for arbitrarily chosen sample are HM=289.95 ± 42.31 MPa, HIT=430.75 ± 45.37 MPa, HV=40.66 ± 4.28 Vickers, EIT=7.37 ± 1.84 GPa for Vickers tip and HM=115.19 ± 15.03 MPa, HIT=165.80 ± 19.30 MPa, HV=16.90 ± 1.97 Vickers, EIT=5.30 ± 1.31 GPa for spherical tip. Results of nanoindentation tests show that this method is very useful and is perfect for obtaining mechanical properties of trabecular bone. Estimated values of elastic modulus are similar. The differences between hardness are significant but it is a result of using two different types of tips. However, it has to be emphasised that the differences in the values of elastic modulus and hardness result from different testing protocols, anisotropy and asymmetry of the micro-samples and the hydration of bone.

Keywords: human bone, mechanical properties, nano hardness nanoindentation, trabecular bone

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Authors: Chin-Hsien Yeh, Shao-Wen Chen, Wen-Shu Huang, Chun-Fu Huang, Jong-Rong Wang, Jung-Hua Yang, Yuh-Ming Ferng, Chunkuan Shih

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In this research, a Fukushima-like conditions is simulated with TRACE and RELAP5. Fukushima Daiichi Nuclear Power Plant (NPP) occurred the disaster which caused by the earthquake and tsunami. This disaster caused extended loss of all AC power (ELAP). Hence, loss of ultimate heat sink (LUHS) happened finally. In order to handle Fukushima-like conditions, Taiwan Atomic Energy Council (AEC) commanded that Taiwan Power Company should propose strategies to ensure the nuclear power plant safety. One of the diverse and flexible coping strategies (FLEX) is a different water injection strategy. It can execute core injection at 20 Kg/cm2 without depressurization. In this study, TRACE and RELAP5 were used to simulate Maanshan nuclear power plant, which is a three loops PWR in Taiwan, under Fukushima-like conditions and make sure the success criteria of FLEX. Reducing core cooling ability is due to failure of emergency core cooling system (ECCS) in extended loss of all AC power situation. The core water level continues to decline because of the seal leakage, and then FLEX is used to save the core water level and make fuel rods covered by water. The result shows that this mitigation strategy can cool the reactor pressure vessel (RPV) as soon as possible under Fukushima-like conditions, and keep the core water level higher than Top of Active Fuel (TAF). The FLEX can ensure the peak cladding temperature (PCT) below than the criteria 1088.7 K. Finally, the FLEX can provide protection for nuclear power plant and make plant safety.

Keywords: TRACE, RELAP5/MOD3.3, ELAP, FLEX

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Authors: Sunitha Sampathi, Pankaj Kumar Tiriya, Sonia Gera, Sravanthi Reddy Pailla, V. Likhitha, A. J. Maruthi

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Surgical site infections (SSIs) are the most common nosocomial infections localized at the incision site. With an estimated 27 million surgical procedures each year in USA, approximately 2-5% rate of SSIs are predicted to occur annually. SSIs are treated with antibiotic medication. Current trend suggest that the direct drug delivery from the suture to the scared tissue can improve patient comfort and wound recovery. For that reason coating the surface of the medical device such as suture and catguts with broad spectrum antibiotics can prevent the formation of bactierial colonies with out comprimising the mechanical properties of the sutures.Hence, the present study was aimed to develop and evaluate a surgical suture coated with an antibiotic Ciprofloxacin hydrochloride loaded on gold nanoparticles. Gold nanoparticles were synthesized by chemical reduction method and conjugated with ciprofloxacin using Polyvinylpyrolidone as stabilizer and gold as carrier. Ciprofloxacin conjugated gold nanoparticles were coated over an absorbable surgical suture made of Polyglactan using sodium alginate as an immobilising agent by slurry dipping technique. The average particle size and Polydispersity Index of drug conjugated gold NPs were found to be 129±2.35 nm and 0.243±0.36 respectively. Gold nanoparticles are characterized by UV-Vis absorption spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR), Scanning electron microscopy and Transmission electron microscopy. FT-IR revealed that there is no chemical interaction between drug and polymer. Antimicrobial activity for coated sutures was evaluated by disc diffusion method on culture plates of both gram negative (E-coli) and gram positive bacteria (Staphylococcus aureus) and results found to be satisfactory. In vivo studies for coated sutures was performed on Swiss albino mice and histological evaluation of intestinal wound healing parameters such as wound edges in mucosa, muscularis, presence of necrosis, exudates, granulation tissue, granulocytes, macrophages, restoration, and repair of mucosal epithelium and muscularis propria on day 7 after surgery were studied. The control animal group, sutured with plain suture (uncoated suture) showed signs of restoration and repair, but presence of necrosis, heamorraghic infiltration and granulation tissue was still noticed. Whereas the animal group treated with ciprofloxacin and ciprofloxacin gold nanoparticle coated sutures has shown promising decrease in terms of haemorraghic infiltration, granulation tissue, necrosis and better repaired muscularis layers on comparision with plain coated sutures indicating faster rate of repair and less chance of sepsis. Hence coating of sutures with broad spectrum antibiotics can be an alternate technique to reduce SSIs.

Keywords: ciprofloxacin hydrochloride, gold nanoparticles, surgical site infections, sutures

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Authors: Najla Alhkalaf

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The focus of this study is answering the following question: How do e-government services in Bahrain support the productivity of SMEs? This study examines the current E-government function in enhancing SME productivity in Bahrain through analysing the efficiency of e- government by viewing its facilitators and barriers from the perspective of different stakeholders. The study aims to identify and develop best practice guidelines with the end-goal of creating a standardised channel of communication between e-government and SMEs that fulfil the requirement of SME owners, and thus achieve the prime objective of e-government. E-government services for SMEs have been offered in Bahrain since 2005. However, the current services lack the required mechanism for SMEs to fully take advantage of these services because of lagging communication between service provider and end-user. E-government employees believe that a lack of awareness and trust are the main stumbling block, whereas the SME owners believe that there is a lack of sufficiency in the content and efficiency provided through e- services. A questionnaire has been created based on a pilot study that highlighted the main indicators of e-government efficiency and SMEs productivity as well as previous studies conducted on this subject. This allowed for quantitative data to be extracted. Also interviews were conducted with SME owners and government employees from both case studies, which formed the qualitative data for this study. The findings portray that both the service provider and service receiver largely agree on the existence of most of the technical and administrative barriers. However, the data reflects a level of dissatisfaction from the SME side, which contradicts with the perceived level of satisfaction from the government employees. Therefore, the data supports the argument that assures the existence of a communication gap between stakeholders. To this effect, this research would help build channels of communication between stakeholders, and then induces a plan unlocking the potential of e-government application. The conclusions of this study will help devise an optimised E-government strategy for Bahrain.

Keywords: e-government, SME, e-services, G2B, government employees' perspective, entrepreneurs' perspective, enterprise

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Authors: Davide Cocchi, Andrea Zucchelli, Luca Raimondi, Maria Brugo Tommaso

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The increasing attention is given to the issues of environmental pollution and climate change is exponentially stimulating the development of electrically propelled vehicles powered by renewable energy, in particular, the solar one. Given the small amount of solar energy that can be stored and subsequently transformed into propulsive energy, it is necessary to develop vehicles with high mechanical, electrical and aerodynamic efficiencies along with reduced masses. The reduction of the masses is of fundamental relevance especially for the unsprung masses, that is the assembly of those elements that do not undergo a variation of their distance from the ground (wheel, suspension system, hub, upright, braking system). Therefore, the reduction of unsprung masses is fundamental in decreasing the rolling inertia and improving the drivability, comfort, and performance of the vehicle. This principle applies even more in solar propelled vehicles, equipped with an electric motor that is connected directly to the wheel hub. In this solution, the electric motor is integrated inside the wheel. Since the electric motor is part of the unsprung masses, the development of compact and lightweight solutions is of fundamental importance. The purpose of this research is the design development and optimization of a CFRP 16 wheel hub motor for solar propulsion vehicles that can carry up to four people. In addition to trying to maximize aspects of primary importance such as mass, strength, and stiffness, other innovative constructive aspects were explored. One of the main objectives has been to achieve a high geometric packing in order to ensure a reduced lateral dimension, without reducing the power exerted by the electric motor. In the final solution, it was possible to realize a wheel hub motor assembly completely comprised inside the rim width, for a total lateral overall dimension of less than 100 mm. This result was achieved by developing an innovative connection system between the wheel and the rotor with a double purpose: centering and transmission of the driving torque. This solution with appropriate interlocking noses allows the transfer of high torques and at the same time guarantees both the centering and the necessary stiffness of the transmission system. Moreover, to avoid delamination in critical areas, evaluated by means of FEM analysis using 3D Hashin damage criteria, electrospun nanofibrous mats have been interleaved between CFRP critical layers. In order to reduce rolling resistance, the rim has been designed to withstand high inflation pressure. Laboratory tests have been performed on the rim using the Digital Image Correlation technique (DIC). The wheel has been tested for fatigue bending according to E/ECE/324 R124e.

Keywords: composite laminate, delamination, DIC, lightweight vehicle, motor hub wheel, nanofiber

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Authors: Corlia van der Walt, Michele K. Havenga

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The study considers corporate governance regulation and practice in South African higher education institutions and makes recommendations for the improvement of current governance practices in this sector. The development of corporate governance principles and practices in South Africa, culminating in the King IV Report on Corporate Governance which was launched in November 2016, is discussed. King IV enjoys international recognition as a progressive corporate governance instrument. It was necessitated by the fundamental changes in business and society nationally and globally, as well as by the significant changes to South African company law introduced by new legislation. Corporate governance and the corporate form are narrowly associated, but there is general recognition that the principles of ethical and effective leadership are not restricted to corporations. Thus King IV was drafted with the express aim that it should apply to all organisations, regardless of their form of incorporation, and the report includes specific sector supplements in support of this aspiration. The South African higher education sector has of late been under intense scrutiny, and a few universities have been placed under administration because of poor governance practices. Universities have also been severely impacted by the consequences of what is generally known as ‘#FeesmustFall’, a student led protest movement initially aimed against the increase of fees at public universities, but which rapidly expanded to also include other concerns. It was clearly necessary to revisit corporate governance policy and practice in the sector. The review of the current higher education governance regime in light of the King IV recommendations, lessons from company law regarding the entrenchment and enforcement of corporate governance principles, and a comparison of higher education governance practices in selected other jurisdictions led to recommendations for the improvement of governance practices in South African higher education. It is further suggested that a sector supplement for higher education institutions may provide additional clarity. Some of the recommendations may be of comparative value for international higher education governance.

Keywords: committees, corporate governance, ethical leadership, higher education institutions, integrated reporting, King IV, sector supplements, sustainability

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Authors: Diego F. Camacho, Cristian J. Mejia, Carlos Duque-Daza

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The recent widespread use of Unmanned Aerial Vehicles (UAVs) has fueled a renewed interest in efficiency and performance of airfoils, particularly for applications at low and moderate Reynolds numbers, typical of this kind of vehicles. Most of previous efforts in the aeronautical industry, regarding aerodynamic efficiency, had been focused on high Reynolds numbers applications, typical of commercial airliners and large size aircrafts. However, in order to increase the levels of efficiency and to boost the performance of these UAV, it is necessary to explore new alternatives in terms of airfoil design and application of drag reduction techniques. The objective of the present work is to carry out the analysis and comparison of performance levels between a standard NACA0012 profile against another one featuring a wall protuberance or surface perturbation. A computational model, based on the finite volume method, is employed to evaluate the effect of the presence of geometrical distortions on the wall. The performance evaluation is achieved in terms of variations of drag and lift coefficients for the given profile. In particular, the aerodynamic performance of the new design, i.e. the airfoil with a surface perturbation, is examined under conditions of incompressible and subsonic flow in transient state. The perturbation considered is a shaped protrusion prescribed as a small surface deformation on the top wall of the aerodynamic profile. The ultimate goal by including such a controlled smooth artificial roughness was to alter the turbulent boundary layer. It is shown in the present work that such a modification has a dramatic impact on the aerodynamic characteristics of the airfoil, and if properly adjusted, in a positive way. The computational model was implemented using the unstructured, FVM-based open source C++ platform OpenFOAM. A number of numerical experiments were carried out at Reynolds number 5x104, based on the length of the chord and the free-stream velocity, and angles of attack 6° and 12°. A Large Eddy Simulation (LES) approach was used, together with the dynamic Smagorinsky approach as subgrid scale (SGS) model, in order to account for the effect of the small turbulent scales. The impact of the surface perturbation on the performance of the airfoil is judged in terms of changes in the drag and lift coefficients, as well as in terms of alterations of the main characteristics of the turbulent boundary layer on the upper wall. A dramatic change in the whole performance can be appreciated, including an arguably large level of lift-to-drag coefficient ratio increase for all angles and a size reduction of laminar separation bubble (LSB) for a twelve-angle-of-attack.

Keywords: CFD, LES, Lift-to-drag ratio, LSB, NACA 0012 airfoil

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Authors: L. S. Zavodna, J. Zavodny Pospisil

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The aim of this paper is to identify the factors for sustainability in the accommodation sector. Although sustainability is a current trend in tourism, not many facilities know how to apply the concept in practice. This paper presents a model for the implementation of sustainability in hotels, hostels, campgrounds, or other facilities. First, there are identified sections of each accommodation facility, which can contribute to sustainability. Furthermore, concrete steps are presented to transfer this model into reality.

Keywords: accommodation sector, model, sustainable tourism, sustainability

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Authors: M. G. Ghanem, A. M. M. A. Allam, Diaa E. Fawzy, Mehmet Faruk Cengiz

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This paper is devoted to the design and implementation of a smartwatch textile antenna for Wi-Fi bio-medical applications in millimetric wave bands. The antenna is implemented on a leather textile-based substrate to be embedded in a smartwatch. It enables the watch to pick Wi-Fi signals without the need to be connected to a mobile through Bluetooth. It operates at 60 GHz or WiGig (Wireless Gigabit Alliance) band with a wide band for higher rate applications. It also could be implemented over many stratified layers of the body organisms to be used in the diagnosis of many diseases like diabetes and cancer. The structure is designed and simulated using CST (Studio Suite) program. The wearable patch antenna has an octagon shape, and it is implemented on leather material that acts as a flexible substrate with a size of 5.632 x 6.4 x 2 mm3, a relative permittivity of 2.95, and a loss tangent of 0.006. The feeding is carried out using differential feed (discrete port in CST). The work provides five antenna implementations; antenna without ground, a ground is added at the back of the antenna in order to increase the antenna gain, the substrate dimensions are increased to 15 x 30 mm2 to resemble the real hand watch size, layers of skin and fat are added under the ground of the antenna to study the effect of human body tissues human on the antenna performance. Finally, the whole structure is bent. It is found that the antenna can achieve a simulated peak realized gain in dB of 5.68, 7.28, 6.15, 3.03, and 4.37 for antenna without ground, antenna with the ground, antenna with larger substrate dimensions, antenna with skin and fat, and bent structure, respectively. The antenna with ground exhibits high gain; while adding the human organisms absorption, the gain is degraded because of human absorption. The bent structure contributes to higher gain.

Keywords: bio medical engineering, millimetric wave, smart watch, textile antennas, Wi-Fi

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Authors: Seyed Abolhasan Naeini, Hamidreza Rahmani

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Laboratory consolidated undrained triaxial (CU) tests were carried out to study the strength behavior of silty soil reinforced with randomly plastic waste bottle chips. Specimens mixed with plastic waste chips in triaxial compression tests with 0.25, 0.50, 0.75, 1.0, and 1.25% by dry weight of soil and tree different length including 4, 8, and 12 mm. In all of the samples, the width and thickness of plastic chips were kept constant. According to the results, the amount and size of plastic waste bottle chips played an important role in the increasing of the strength parameters of reinforced silt compared to the pure soil. Because of good results, the suggested method of soil improvement can be used in many engineering problems such as increasing the bearing capacity and settlement reduction in foundations.

Keywords: reinforcement, silt, soil improvement, triaxial test, waste bottle chips

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Authors: Julius Adebayo John

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The objective of this study is to compare the use of medicinal plants and Conventional medicine intervention in the management of HBV among Ibadan populace. A purposive sampling technique was used to administer questionnaires at 2 places, namely, the University College Hospital and Total Healthcare Diagnostic Centre, Ibadan, where viral loads are carried out. A EuroQol (EQ – 5D) was adopted to collect data. Descriptive and inferential analyses were performed. Also, ANOVA, Correlation, charts, and tables were used. Findings revealed a high prevalence of HBV among female respondents and sample between ages 26years to 50years. Results showed that the majority discovered their health status through free HBV tests. Analysis indicated that the use of medicinal plant extract is cost-effective in 73% of cases. Rank order utility derived from medicinal plants is higher than other interventions. Correlation analysis performed for the current health status of respondents were significant at P<0.01 against the intervention management adopted (0.046), cost of treatment (0.549), utility (0.407) at P<0.00, duration of the treatment (0.604) at P<0.01; viral load before treatment (-0.142) not significant at P<0.01, the R2 (72.2%) showed the statistical variance in respondents current health status as explained by the independent variables. Respondents gained quality-adjusted life-years (QALYs) of between 1year to 3years. Suggestions were made for a public-private partnership effort against HBV with emphasis on periodic screening, viral load test subsidy, and free vaccination of people with –HBV status. Promoting phytomedicine through intensive research with strong regulation of herbal practitioners will go a long way in alleviating the burdens of the disease in society.

Keywords: medicinal plant, HBV management interventions, utility, QALYs, ibadan metropolis

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Authors: Catelyn Coyle, Helena Kwakwa

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Objective: As novel and better tolerated therapies become available, effective HCV testing and care models become increasingly necessary to not only identify individuals with active infection but also link them to HCV providers for medical evaluation and treatment. Our aim is to describe an effective HCV testing and linkage to care model piloted in a network of five community health centers located in Philadelphia, PA. Methods: In October 2012, National Nursing Centers Consortium piloted a routine opt-out HCV testing model in a network of community health centers, one of which treats HCV, HIV, and co-infected patients. Key aspects of the model were medical assistant initiated testing, the use of laboratory-based reflex test technology, and electronic medical record modifications to prompt, track, report and facilitate payment of test costs. Universal testing on all adult patients was implemented at health centers serving patients at high-risk for HCV. The other sites integrated high-risk based testing, where patients meeting one or more of the CDC testing recommendation risk factors or had a history of homelessness were eligible for HCV testing. Mid-course adjustments included the integration of dual HIV testing, development of a linkage to care coordinator position to facilitate the transition of HIV and/or HCV-positive patients from primary to specialist care, and the transition to universal HCV testing across all testing sites. Results: From October 2012 to June 2015, the health centers performed 7,730 HCV tests and identified 886 (11.5%) patients with a positive HCV-antibody test. Of those with positive HCV-antibody tests, 838 (94.6%) had an HCV-RNA confirmatory test and 590 (70.4%) progressed to current HCV infection (overall prevalence=7.6%); 524 (88.8%) received their RNA-positive test result; 429 (72.7%) were referred to an HCV care specialist and 271 (45.9%) were seen by the HCV care specialist. The best linkage to care results were seen at the test and treat the site, where of the 333 patients were current HCV infection, 175 (52.6%) were seen by an HCV care specialist. Of the patients with active HCV infection, 349 (59.2%) were unaware of their HCV-positive status at the time of diagnosis. Since the integration of dual HCV/HIV testing in September 2013, 9,506 HIV tests were performed, 85 (0.9%) patients had positive HIV tests, 81 (95.3%) received their confirmed HIV test result and 77 (90.6%) were linked to HIV care. Dual HCV/HIV testing increased the number of HCV tests performed by 362 between the 9 months preceding dual testing and first 9 months after dual testing integration, representing a 23.7% increment. Conclusion: Our HCV testing model shows that integrated routine testing and linkage to care is feasible and improved detection and linkage to care in a primary care setting. We found that prevalence of current HCV infection was higher than that seen in locally in Philadelphia and nationwide. Intensive linkage services can increase the number of patients who successfully navigate the HCV treatment cascade. The linkage to care coordinator position is an important position that acts as a trusted intermediary for patients being linked to care.

Keywords: HCV, routine testing, linkage to care, community health centers

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Authors: Robyn L. Curran, Joanne R. Naidoo, Gugu Mchunu

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Along with the increasing awareness of human trafficking, is the acknowledgement that it is no longer just a social problem but also a significant public health problem that requires both increased knowledge and the specialist equipping of aftercare providers such as nurses who care for human trafficking survivors. Current discourse regarding aftercare of human trafficking survivors, is that approaches do not clearly explain the function or content of aftercare and what aftercare entails. Although psychological and medical aftercare are emphasized as important components, little practical attention is devoted to what these components actually involve and the effectiveness of current practice in aftercare. Review of the literature on the processes that take place from aftercare to empowerment, revealed the need for emphasis to be placed on the voices of survivors concerning their liberation from oppression. The aim of the study was to develop a theory for aftercare of human trafficking survivors, through analyzing the experiences of survivors and aftercare providers in shelters in three provinces in South Africa. Through using a Straussian grounded theory approach, the researcher developed a theory to inform care of human trafficking survivors in low resource settings using the voice of the survivors and those experienced in direct care of human trafficking survivors. Four human trafficking survivors and three aftercare providers from three shelters in three provinces in South Africa were individually interviewed in order for the theory to emerge. The findings of the study elicited a theoretical model of the renewed self, and the conditions that facilitate this process in care of human trafficking survivors. The process that human trafficking survivors navigate to empowerment require mutual collaboration of the aftercare provider and survivor as the survivor awakens vision, confronts reality, re-salvages autonomy and liberates self. Psychological resilience of the survivor facilitates the transition to renewed self. The recommendations of this study may improve the nursing care provided to human trafficking survivors and equip professionals with knowledge and skills to promote the process of renewing self for survivors.

Keywords: aftercare, aftercare providers, grounded theory, human trafficking survivors

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Authors: Rosyidah, Permata Wulandari

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We investigate the price effect of addition and deletions from the Indonesia Sharia Stock Index (ISSI) and Jakarta Islamic Index (JII). Using event study methodology, we measure abnormal returns for firms over the period June 2019 - to December 2021. Through the sample of 107 additions and 95 deletions, we find evidence to support the theory of Muslim country investment behavior. We find that additions to the Islamic index led to a significant positive stock market reaction and deletions to the Islamic index led to a negative stock market reaction on Jakarta Islamic Index (JII) and there is no significant reaction of addition and deletion on Indonesia Sharia Stock Index (ISSI).

Keywords: abnormal return, abnormal volume, event study, index changes, sharia index

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Authors: May Maricel De Gracia

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Different generations respond differently to instruction because of their diverse characteristics, learning styles and study habits. Teaching strategies that were effective many years ago may not be effective now especially to the current generation which is Gen Z. Using quantitative research design, the main goal of this paper is to determine the impact of the implementation of educational technology integration in a private high school in the math performance of its Junior High School (JHS) students on SY 2014-2018 based on their periodical exam performance and on their final math grades. In support, survey on the use of technology was administered to determine the characteristics of both students and teachers of SY 2017-2018. Another survey regarding study habits was also administered to the students to determine their readiness with regards to note-taking skills, time management, test taking/preparation skills, reading, and writing and math skills. Teaching strategies were recommended based on the need of the current Gen Z JHS students. A total of 712 JHS students and 12 math teachers participated in answering the different surveys. Periodic exam means and final math grades between the school years without technology (SY 2004-2008) and with technology (SY 2014-2018) were analyzed through correlation and regression analyses. Result shows that the periodic exam mean has a 35.29% impact to the final grade of the students. In addition, z-test result where p > 0.05 shows that the periodical exam results do not differ significantly between the school years without integration of technology and with the integration of technology. However, with p < 0.01, a significant positive difference was observed in the final math grades of students between the school years without technology integration and with technology integration.

Keywords: classroom instruction, technology, generation z, math performance

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Authors: Amir Raeisdana, Davood Sohrabi, Mojtaba Nohekhan, Ameneh Kargarian, Maryam Ghapanvari, Alireza Aslezaeem

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Improvement of zirconium properties by chromium coating and nitrogen implantation is ideal to protect the nuclear fuel rods against corrosion and secondary hydrogenation. Metallic chromium (Cr) has attracted attention as a potential coating material on zirconium alloys, to limit external cladding corrosion. In this research, high energy plasma focus device was used to coat the chromium and implant the nitrogen ions in the zirconium substrate. This device emits high-energy nitrogen ions of 10 keV-1 MeV and with a flux of 10^16 ions/cm^2 in each shot toward the target so it is attractive for implantation on the substrate materials at the room temperature. Six zirconium samples in 2cm×2cm dimensions with 1mm thickness were located at a distance of 20cm from the place where the pinch is formed. The experiments are carried out in 0.5 mbar of the nitrogen gas pressure and 15 kV of the charging voltage. Pure Cr disc was installed on the anode head for sputtering of the chromium and deposition on zirconium substrate. When the pinch plasma column decays due to various instabilities, intense and high-energy N2 ions are accelerated towards the zirconium substrate also sputtered Cr is deposited on the zirconium substrate. XRD and XRF analysis were used to study the structural properties of the samples. XRF analysis indicates 77.1% of Zr and 11.1% of Cr in the surface of the sample. XRD spectra shows the formation of ZrN, CrN and CrZr composites after nitrogen implantation and chromium coating. XRD spectra shows the chromium peak height equal to 152.80 a.u. for the major sample (θ=0֯) and 92.99 a.u. for the minor sample (θ=6֯), so implantation and coating along the main axis of the device is significantly more than other directions.

Keywords: ZrN and CrN and CrZr composites, angular distribution for Cr deposition rate, zirconium corrosion resistance, nuclear fuel rods, plasma focus device

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Authors: Latha Krishnan, Andrew Cobley

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Epoxy resin is most widely used as matrices for composites of aerospace, automotive and electronic applications due to its outstanding mechanical properties. These properties are chiefly predetermined by the chemical structure of the prepolymer and type of hardener but can also be varied by the processing conditions such as prepolymer and hardener mixing, degassing and curing conditions. In this research, the effect of degassing on the curing behaviour and the void occurrence is experimentally evaluated for epoxy /anhydride resin system. The epoxy prepolymer was mixed with an anhydride hardener and accelerator in an appropriate quantity. In order to investigate the effect of degassing on the curing behaviour and void content of the resin, the uncured resin samples were prepared using three different methods: 1) no degassing 2) degassing on prepolymer and 3) degassing on mixed solution of prepolymer and hardener with an accelerator. The uncured resins were tested in differential scanning calorimeter (DSC) to observe the changes in curing behaviour of the above three resin samples by analysing factors such as gel temperature, peak cure temperature and heat of reaction/heat flow in curing. Additionally, the completely cured samples were tested in DSC to identify the changes in the glass transition temperature (Tg) between the three samples. In order to evaluate the effect of degassing on the void content and morphology changes in the cured epoxy resin, the fractured surfaces of cured epoxy resin were examined under the scanning electron microscope (SEM). Also, the changes in the mechanical properties of the cured resin were studied by three-point bending test. It was found that degassing at different stages of resin mixing had significant effects on properties such as glass transition temperature, the void content and void size of the epoxy/anhydride resin system. For example, degassing (vacuum applied on the mixed resin) has shown higher glass transition temperature (Tg) with lower void content.

Keywords: anhydride epoxy, curing behaviour, degassing, void occurrence

Procedia PDF Downloads 347

Authors: Murat Toren, Mehmet Çelebi

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Reducing the weight of transformers while providing good performance, cost reduction and increased efficiency is important. Weight is one of the most significant factors in all electrical machines, and as such, many transformer design parameters are related to weight calculations. This study presents a comparison of the weight of oil type transformers and dry type transformer weight. Oil type transformers are mainly used in industry; however, dry type transformers are becoming more widespread in recent years. MATLAB is typically used for designing transformers and design parameters (rated voltages, core loss, etc.) along with design in ANSYS Maxwell. Similar to other studies, this study presented that the dry type transformer option is limited. Moreover, the commonly-used 50 kVA distribution transformers in the industry are oil type and dry type transformers are designed and considered in terms of weight. Currently, the preference for low-cost oil-type transformers would change if costs for dry-type transformer were more competitive. The aim of this study was to compare the weight of transformers, which is a substantial cost factor, and to provide an evaluation about increasing the use of dry type transformers.

Keywords: weight, optimization, oil-type transformers, dry-type transformers

Procedia PDF Downloads 354

Authors: Samson Mil'shtein, Dhawal Asthana, Benjamin Sullivan

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The wide energy gap of GaN is the major parameter justifying the design and fabrication of high-power electronic components made of this material. However, the existence of a piezo-electrics in nature sheet charge at the AlGaN/GaN interface complicates the control of carrier injection into the intrinsic channel of GaN HEMTs (High Electron Mobility Transistors). As a result, most of the transistors created as R&D prototypes and all of the designs used for mass production are D-mode devices which introduce challenges in the design of integrated circuits. This research presents the design and modeling of an E-mode GaN HEMT with a very low turn-on voltage. The proposed device includes two critical elements allowing the transistor to achieve zero conductance across the channel when Vg = 0V. This is accomplished through the inclusion of an extremely thin, 2.5nm intrinsic Ga₀.₇₄Al₀.₂₆N spacer layer. The added spacer layer does not create piezoelectric strain but rather elastically follows the variations of the crystal structure of the adjacent GaN channel. The second important factor is the design of a gate metal with a high work function. The use of a metal gate with a work function (Ni in this research) greater than 5.3eV positioned on top of n-type doped (Nd=10¹⁷cm⁻³) Ga₀.₇₄Al₀.₂₆N creates the necessary built-in potential, which controls the injection of electrons into the intrinsic channel as the gate voltage is increased. The 5µm long transistor with a 0.18µm long gate and a channel width of 30µm operate at Vd=10V. At Vg =1V, the device reaches the maximum drain current of 0.6mA, which indicates a high current density. The presented device is operational at frequencies greater than 10GHz and exhibits a stable transconductance over the full range of operational gate voltages.

Keywords: compound semiconductors, device modeling, enhancement mode HEMT, gallium nitride

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Authors: David Nogueiras Blanco, Amir Alwash, Arnaud Gaudinat, René Schneider

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At a time when the access to and the sharing of information are crucial in the world of research, the use of technologies such as persistent identifiers (PIDs), Current Research Information Systems (CRIS), and ontologies may create platforms for information sharing if they respond to the need of disambiguation of their data by assuring interoperability inside and between other systems. INCIPIT-CRIS is a continuation of the former INCIPIT project, whose goal was to set up an infrastructure for a low-cost attribution of PIDs with high granularity based on Archival Resource Keys (ARKs). INCIPIT-CRIS can be interpreted as a logical consequence and propose a research information management system developed from scratch. The system has been created on and around the Schema.org ontology with a further articulation of the use of ARKs. It is thus built upon the infrastructure previously implemented (i.e., INCIPIT) in order to enhance the persistence of URIs. As a consequence, INCIPIT-CRIS aims to be the hinge between previously separated aspects such as CRIS, ontologies and PIDs in order to produce a powerful system allowing the resolution of disambiguation problems using a combination of an ontology such as Schema.org and unique persistent identifiers such as ARK, allowing the sharing of information through a dedicated platform, but also the interoperability of the system by representing the entirety of the data as RDF triplets. This paper aims to present the implemented solution as well as its simulation in real life. We will describe the underlying ideas and inspirations while going through the logic and the different functionalities implemented and their links with ARKs and Schema.org. Finally, we will discuss the tests performed with our project partner, the Swiss Institute of Bioinformatics (SIB), by the use of large and real-world data sets.

Keywords: current research information systems, linked data, ontologies, persistent identifier, schema.org, semantic web

Procedia PDF Downloads 135

Authors: Parminder Kaur Heer, Alexei Lapkin

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Due to global challenges of increased competition and demand for more sustainable products/processes, there is a rising pressure on the industry to develop innovative processes. Through Process Intensification (PI) the existing and new processes may be able to attain higher efficiency. However, very few PI options are generally considered. This is because processes are typically analysed at a unit operation level, thus limiting the search space for potential process options. PI performed at more detailed levels of a process can increase the size of the search space. The different levels at which PI can be achieved is unit operations, functional and phenomena level. Physical/chemical phenomena form the lowest level of aggregation and thus, are expected to give the highest impact because all the intensification options can be described by their enhancement. The objective of the current work is thus, generation of numerous process alternatives based on phenomena, and development of their corresponding computer aided models. The methodology comprises: a) automated generation of process options, and b) automated generation of process models. The process under investigation is disintegrated into functions viz. reaction, separation etc., and these functions are further broken down into the phenomena required to perform them. E.g., separation may be performed via vapour-liquid or liquid-liquid equilibrium. A list of phenomena for the process is formed and new phenomena, which can overcome the difficulties/drawbacks of the current process or can enhance the effectiveness of the process, are added to the list. For instance, catalyst separation issue can be handled by using solid catalysts; the corresponding phenomena are identified and added. The phenomena are then combined to generate all possible combinations. However, not all combinations make sense and, hence, screening is carried out to discard the combinations that are meaningless. For example, phase change phenomena need the co-presence of the energy transfer phenomena. Feasible combinations of phenomena are then assigned to the functions they execute. A combination may accomplish a single or multiple functions, i.e. it might perform reaction or reaction with separation. The combinations are then allotted to the functions needed for the process. This creates a series of options for carrying out each function. Combination of these options for different functions in the process leads to the generation of superstructure of process options. These process options, which are formed by a list of phenomena for each function, are passed to the model generation algorithm in the form of binaries (1, 0). The algorithm gathers the active phenomena and couples them to generate the model. A series of models is generated for the functions, which are combined to get the process model. The most promising process options are then chosen subjected to a performance criterion, for example purity of product, or via a multi-objective Pareto optimisation. The methodology was applied to a two-step process and the best route was determined based on the higher product yield. The current methodology can identify, produce and evaluate process intensification options from which the optimal process can be determined. It can be applied to any chemical/biochemical process because of its generic nature.

Keywords: Phenomena, Process intensification, Process models , Process options

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Authors: Pawan S. Nagda, Purnank S. Bhatt, Mit K. Shah

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Earing defect in drawing process is highly undesirable not only because it adds on an additional trimming operation but also because the uneven material flow demands extra care. The objective of this work is to study the earing problem in the Deep Drawing of circular cup and to optimize the blank shape to reduce the earing. A finite element model is developed for 3-D numerical simulation of cup forming process in ABAQUS. Extra-deep-drawing (EDD) steel sheet has been used for simulation. Properties and tool design parameters were used as input for simulation. Earing was observed in the simulated cup and it was measured at various angles with respect to rolling direction. To reduce the earing defect initial blank shape was modified with the help of anisotropy coefficient. Modified blanks showed notable reduction in earing.

Keywords: anisotropy, deep drawing, earing, finite element simulation

Procedia PDF Downloads 377

Authors: Vinu Elias Jacob, Manoj Kumar Kini

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Disasters of all types are occurring more frequently and are becoming more costly than ever due to various manmade factors including climate change. A better utilisation of the concept of governance and management within disaster risk reduction is inevitable and of utmost importance. There is a need to explore the role of pre- and post-disaster public policies. The role of urban planning/design in shaping the opportunities of households, individuals and collectively the settlements for achieving recovery has to be explored. Governance strategies that can better support the integration of disaster risk reduction and management has to be examined. The main aim is to thereby build the resilience of individuals and communities and thus, the states too. Resilience is a term that is usually linked to the fields of disaster management and mitigation, but today has become an integral part of planning and design of cities. Disaster resilience broadly describes the ability of an individual or community to 'bounce back' from disaster impacts, through improved mitigation, preparedness, response, and recovery. The growing population of the world has resulted in the inflow and use of resources, creating a pressure on the various natural systems and inequity in the distribution of resources. This makes cities vulnerable to multiple attacks by both natural and man-made disasters. Each urban area needs elaborate studies and study based strategies to proceed in the discussed direction. Cochin in Kerala is the fastest and largest growing city with a population of more than 26 lakhs. The main concern that has been looked into in this paper is making cities resilient by designing a framework of strategies based on urban design principles for an immediate response system especially focussing on the city of Cochin, Kerala, India. The paper discusses, understanding the spatial transformations due to disasters and the role of spatial planning in the context of significant disasters. The paper also aims in developing a model taking into consideration of various factors such as land use, open spaces, transportation networks, physical and social infrastructure, building design, and density and ecology that can be implemented in any city of any context. Guidelines are made for the smooth evacuation of people through hassle-free transport networks, protecting vulnerable areas in the city, providing adequate open spaces for shelters and gatherings, making available basic amenities to affected population within reachable distance, etc. by using the tool of urban design. Strategies at the city level and neighbourhood level have been developed with inferences from vulnerability analysis and case studies.

Keywords: disaster management, resilience, spatial planning, spatial transformations

Procedia PDF Downloads 296

Authors: Teresa McGrath, Ryan Johnson, Rebecca Stamm, Cassidy Clarity, Wei Yung Lui

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Building and construction is the second largest plastic user behind packaging, accounting for 16% of plastic production. Building and construction is also by far the largest user of one of the most impactful plastics, polyvinyl chloride (aka vinyl or PVC), accounting for 69% of PVC production. Building materials also have an outsized contribution to plastic pollution, including microplastic pollution. Yet building materials are often overlooked in plastic waste and pollution reduction efforts. Habitable will present a plastics and petrochemical analysis of over 250 common building material types and demonstrate how changes to building material selection towards safer, renewable, and lower carbon materials can reduce global consumption of plastics and associated pollution.

Keywords: building materials, fenceline communities, microplastics, safer alternatives, embodied carbon, life cycle analysis, petrochemicals, green chemistry

Procedia PDF Downloads 23