Search results for: supplier selection problem

Authors: Jie Zhang, Qianyu Guo, Tieyi Zhang, Zhiyong Feng, Xiaohong Li

Abstract:

With the widespread popularity of mobile devices and the development of artificial intelligence (AI), deep learning (DL) has been extensively applied in Android apps. Compared with traditional Android apps (traditional apps), deep learning based Android apps (DL-based apps) need to use more third-party application programming interfaces (APIs) to complete complex DL inference tasks. However, existing methods (e.g., FlowDroid) for detecting sensitive information leakage in Android apps cannot be directly used to detect DL-based apps as they are difficult to detect third-party APIs. To solve this problem, we design DLtrace; a new static information flow analysis tool that can effectively recognize third-party APIs. With our proposed trace and detection algorithms, DLtrace can also efficiently detect privacy leaks caused by sensitive APIs in DL-based apps. Moreover, using DLtrace, we summarize the non-sequential characteristics of DL inference tasks in DL-based apps and the specific functionalities provided by DL models for such apps. We propose two formal definitions to deal with the common polymorphism and anonymous inner-class problems in the Android static analyzer. We conducted an empirical assessment with DLtrace on 208 popular DL-based apps in the wild and found that 26.0% of the apps suffered from sensitive information leakage. Furthermore, DLtrace has a more robust performance than FlowDroid in detecting and identifying third-party APIs. The experimental results demonstrate that DLtrace expands FlowDroid in understanding DL-based apps and detecting security issues therein.

Keywords: mobile computing, deep learning apps, sensitive information, static analysis

Procedia PDF Downloads 139

Authors: John Joseph S. Martis, Rohanchandra R. Gatty, Aaron Jose Fernandes, Rahul P. Nambiar

Abstract:

Introduction: Surgery for breast cancer is either mastectomy or breast conservation surgery. The most commonly used incision for modified radical mastectomy is the transverse Stewart incision. But this incision may have the disadvantage of causing disparity between the closure lines of superior and inferior skin flaps in mastectomy and can cause overhanging of soft tissue below and behind the axilla. The curvizigzag incision, on principle, may help in this regard and can prevent scar migration beyond the anterior axillary line. This study aims to compare the two incisions in this regard. Methods: 100 patients with cancer of breast were included in the study after satisfying inclusion and exclusion criteria. They underwent surgery at Father Muller Medical College, Mangalore, India, between November 2019 to September 2021. The patients were divided into two groups. Group A patients were subjected to modified radical mastectomy with curvizigzag incision and group B patients with transverse Stewart incision. Results: Seroma on postoperative day1, day 2 was 0% in both the groups. Seroma on postoperative day 30 was present in 14% of patients in group B. 60% of patients in group B had sag of soft tissue below and behind the axilla, and none of the patients in group A had this problem. In 64% of the patients in group B, the incision crossed the anterior axillary fold, 64% of the patients in group B had tension in the incision site while approximation of the skin flaps. Conclusion: Curvizigzag incision is statistically better with lesser complications when compared to the transverse Stewart incision for modified radical mastectomy for carcinoma breast.

Keywords: breast cancer, curvizigzag incision, transverse Stewart incision, seroma, modified radical mastectomy

Procedia PDF Downloads 73

Authors: Evangelos Tsakalos, Maria Kazantzaki, Eleni Filippaki, Yannis Bassiakos

Abstract:

The coastal areas of the Mediterranean have been extensively affected by the transgressive event that followed the Last Glacial Maximum, with many studies conducted regarding the stratigraphic configuration of coastal sediments around the Mediterranean. The coastal zone of the Messologi area, western Greece, consists of low relief beaches containing low cliffs and eroded dunes, a fact which, in combination with the rising sea level and tectonic subsidence of the area, has led to substantial coastal. Coastal vulnerability assessment is a useful means of identifying areas of coastline that are vulnerable to impacts of climate change and coastal processes, highlighting potential problem areas. Commonly, coastal vulnerability assessment takes the form of an ‘index’ that quantifies the relative vulnerability along a coastline. Here we make use of the coastal vulnerability index (CVI) methodology by Thieler and Hammar-Klose, by considering geological features, coastal slope, relative sea-level change, shoreline erosion/accretion rates, and mean significant wave height as well as mean tide range to assess the present-day vulnerability of the coastal zone of Messologi area. In light of this, an impact assessment is performed under three different sea level rise scenarios, and adaptation measures to control climate change events are proposed. This study contributes toward coastal zone management practices in low-lying areas that have little data information, assisting decision-makers in adopting best adaptations options to overcome sea level rise impact on vulnerable areas similar to the coastal zone of Messologi.

Keywords: coastal vulnerability index, coastal erosion, sea level rise, GIS

Procedia PDF Downloads 156

Authors: Monsuru Oyenola Popoola, Oladapo Samson Abiola, Wusamotu Alao Adeniji

Abstract:

The prevalent and incessant abandonment of road construction projects are alarming that it creates several negative effects to social, economic and environmental values of the project. The purpose of this paper is to investigate and determined the various causes and effects of abandoning road construction projects in Nigeria. Likert Scale questionnaire design was used to administered and analysed the data obtained for the stydy. 135 (Nr) questionnaires were completed and retrieved from the respondents, out of 200 (Nr) questionnaires sent out, representing a response rate of 67.5%. The analysis utilized the Relative Importance Index (R.I.I.) method and the results are presented in tabular form. The findings confirms that at least 20 factors were the causes of road projects abandonment in Nigeria with most including Leadership Instability, Improper Project Planning, Inconsistence in government policies and Design, Contractor Incompetence, Economy Instability and Inflation, Delay in remittance of money, Improper financial analysis, Poor risk management, Climatic Conditions, Improper Project Estimates etc. The findings also show that at least eight (8) effect were identified on the system, and these include; Waste of Financial Resources, Loss of economic value, Environmental degradation, Loss of economic value, Reduction in standard of living, Litigation and Arbitration, etc. The reflection is that allocating reasonable finance, developing appropriate and effective implementation plans and monitoring, evaluation and reporting on development project activities by key actors should enhance in resolving the problem of road projects abandonment.

Keywords: road construction, abandonment of road projects, climatic condition, project planning, contractor

Procedia PDF Downloads 284

Authors: Shantanu Prakash, Suruchi Shukla, Amita Jain

Abstract:

Introduction: The hepatitis C virus (HCV) is a major public health problem and a leading cause of chronic liver disease. Injection drug use and individuals receiving blood and blood products are the primary modes of HCV transmission. Our study aims to establish the prevalent genotypes/ subtypes of HCV circulating in Uttar Pradesh, North India, as reported from a tertiary care hospital. Methods: It is a retrospective observational analysis of consecutive 404 HCV RNA positive cases referred to our hospital during September 2014 to April 2017. The study was approved by an institutional ethics committee. Written informed consent was taken from each participant. Clinical and demographic details of these patients were recorded using predesigned questionnaires. All the laboratory testing was carried on stored serum sample of enrolled cases. Genotyping of all 404 strains was done by Sanger’s sequencing of the core region. The phylogenetic analysis of 179 HCV strains with high -quality sequencing data was performed. Results: The distribution of prevalent genotypes/ subtypes as noted in the present study was; Genotype (GT)1a [n-101(25%)], GT1b [n-12(2.9%)], GT1c [1(0.25%)], GT3a [275(68.07%)], GT3b [9(2.2%)], GT3g [2(0.49%)], GT3i [3(0.74%)], and GT4a [1(0.24%)]. HCV genotypes GT2, GT5 and GT6 were not detected from our region. Sequence analysis showed high genotypic variability in HCV GT3. Phylogenetic analysis showed that HCV GT3 and GT1 circulating in our region were related to Indian strains reported earlier. Conclusions: HCV genotypes 3a and 1a are commonest circulating genotypes in Uttar Pradesh (UP), India.

Keywords: Hepatitis C virus, genetic variation, bioinformatics, genotype, HCV

Procedia PDF Downloads 136

Authors: Carolyne Ndungu, Wesley Too, Diana Kassaman

Abstract:

Diabetes is a global public health problem with an increasing morbidity and mortality rate across the globe. It is reported that 422 million people worldwide have diabetes with type 2 diabetes more common in people of African descent. Whilst prevalence of diabetes is four times more than it was in the last three decades, making it the world's ninth greatest cause of mortality, treatment of complications resulting from poor glycemic control is still high, contributing to poverty level in sub-Saharan. Poor treatment adherence has also been identified as a major contributing factor poor glycemic control among diabetic patients and still remains a significant challenge especially among patients living in rural Kenya. This study therefore seeks to identify gaps, barriers and challenges towards medication non-adherence among diabetic patients on follow-up at Kiambu County Referral Hospital, Kenya. Methods: A cross- sectional descriptive study was carried out at Gatundu Level five Hospital in Kiambu County. The study population consisted of adult patients with type two diabetes mellitus (T2DM) on follow up, at the Diabetes clinic between the month of June to July 2022. Systematic sampling of 200 participants was carried out. Ethical approvals from relevant authorities were done and ethical aspects of the study were also observed. Data analysis is ongoing using logistic regression analysis. Results, recommendations -contribution of this study will be highlighted within the next one month.

Keywords: adherence, diabetes, medication, Kenya

Procedia PDF Downloads 113

Authors: Shishir Lamichhane, Saurav Dulal, Bibek Gautam, Madan Thapa Magar, Indraman Tamrakar

Abstract:

Renewable energies such as wind turbines and solar photovoltaic have gained significance as a result of global environmental pollution and energy crises. These sources of energy are converted into electrical energy and delivered to end-users through the utility system. As a result of the widespread use of power electronics-based grid-interfacing technologies to accommodate renewable sources of energy, the prevalence of converters has expanded as well. As a result, the power system's rotating inertia is decreasing, endangering the utility grid's stability. The use of Virtual Synchronous Machine (VSM) technology has been proposed to overcome the grid stability problem due to low rotating inertia. The grid-connected inverter used in VSM can be controlled to emulate inertia, which replicates the external features of a synchronous generator. As a result, the rotating inertia is increased to support the power system's stability. A power angle control strategy is proposed in this paper and its model is simulated in MATLAB/Simulink to study the effects of parameter disturbances on the active power and frequency for a VSM. The system consists of a synchronous generator, which is modeled in such a way that the frequency drops to an unacceptable region during transient conditions due to a lack of inertia when VSM is not used. Then, the suggested model incorporating VSM emulates rotating inertia, injecting a controllable amount of energy into the grid during frequency transients to enhance transient stability.

Keywords: damping constant, inertia–constant, ROCOF, transient stability, distributed sources

Procedia PDF Downloads 195

Authors: Tracy Smith-Carrier

Abstract:

In 1995, the World Health Organization declared that poverty was the biggest killer and the greatest cause of suffering in the world. Income is certainly a key social determinant of health, the lack of which causes innumerable health and mental health conditions. In seeking to provide relief from financial hardship for residents within their populace, states in the Global North have largely turned to the non-profit and charitable sector. The stigma and shame of accessing charity is a significant barrier for many, but what is more problematic is that the embrace of the charitable model has let governments off the hook from responding to their international human rights obligations. Although states are signatories to various human rights treaties and conventions internationally, many of these laws have not been implemented domestically. This presentation explores the limits of the charitable model in addressing poverty in countries of the Global North. Unlike in the ages passed, when poverty was thought to be an individual problem, we now know that poverty is largely systemic in nature. In this presentation, we will identify the structural determinants of poverty, outline why people are reticent to access charitable programs and services and how income security is reproduced through the charitable model, and discuss evidence-informed solutions, such as a basic income guarantee, to move beyond the charitable model in favour of a rights-based justice model. To move beyond charity, we must demand that governments recognize our fundamental human rights and address poverty and hunger using a justice model based on substantive human rights.

Keywords: basic income, charity, poverty, income security, hunger, food security, social justice, human rights

Procedia PDF Downloads 93

Authors: A. Driouiche, S. Mohareb, A. Hadfi

Abstract:

In Morocco’s Agadir region, the reuse of treated wastewater for irrigation of green spaces has faced the problem of scaling of the pipes of these waters. This research paper aims at studying the phenomenon of scaling caused by the treated wastewater from the Mzar sewage treatment plant. These waters are used in the irrigation of golf turf for the Ocean Golf Resort. Ocean Golf, located about 10 km from the center of the city of Agadir, is one of the most important recreation centers in Morocco. The course is a Belt Collins design with 27 holes, and is quite open with deep challenging bunkers. The formation of solid deposits in the irrigation systems has led to a decrease in their lifetime and, consequently, a loss of load and performance. Thus, the sprinklers used in golf turf irrigation are plugged in the first weeks of operation. To study this phenomenon, the wastewater used for the irrigation of the golf turf was taken and analyzed at various points, and also samples of scale formed in the circuits of the passage of these waters were characterized. This characterization of the scale was performed by X-ray fluorescence spectrometry, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The results of the physicochemical analysis of the waters show that they are full of bicarbonates (653 mg/L), chloride (478 mg/L), nitrate (412 mg/L), sodium (425 mg/L) and calcium (199mg/L). Their pH is slightly alkaline. The analysis of the scale reveals that it is rich in calcium and phosphorus. It is formed of calcium carbonate (CaCO₃), silica (SiO₂), calcium silicate (Ca₂SiO₄), hydroxylapatite (Ca₁₀P₆O₂₆), calcium carbonate and phosphate (Ca₁₀(PO₄) 6CO₃) and silicate calcium and magnesium (Ca₅MgSi₃O₁₂).

Keywords: Agadir, irrigation, scaling water, wastewater

Procedia PDF Downloads 102

Authors: Muhammad Ameer Nawaz Akram

Abstract:

The 21st century has been revealed that many individuals around the world are living in urban settlements than in rural zones. The evolution of numerous cities in emerging and newly developed countries is accompanied by the rise of slums. The precise definition of a slum varies countries to countries, but the universal harmony is that slums are dilapidated settlements facing severe poverty and have lacked access to sanitation, water, electricity, good living styles, and land tenure. The slum settlements always vary in unique patterns within and among the countries and cities. The core objective of this study is the spatial identification and classification of slums in Gujrat city Pakistan from very high-resolution GeoEye-1 (0.41m) satellite imagery. Slums were first identified using GPS for sample site identification and ground-truthing; through this process, 425 slums were identified. Then Object-Oriented Analysis (OOA) was applied to classify slums on digital image. Spatial analysis softwares, e.g., ArcGIS 10.3, Erdas Imagine 9.3, and Envi 5.1, were used for processing data and performing the analysis. Results show that OOA provides up to 90% accuracy for the identification of slums. Jalal Cheema and Allah Ho colonies are severely affected by slum settlements. The ratio of criminal activities is also higher here than in other areas. Slums are increasing with the passage of time in urban areas, and they will be like a hazardous problem in coming future. So now, the executive bodies need to make effective policies and move towards the amelioration process of the city.

Keywords: slums, GPS, satellite imagery, object oriented analysis, zonal change detection

Procedia PDF Downloads 111

Authors: Nabila Mohamed, Santiago Aparicio, Bahman Tohidi, Mert Atilhan

Abstract:

Qatar's one of the biggest problem in processing its natural resource, which is natural gas, is the often occurring blockage in the pipelines caused due to uncontrolled gas hydrate formation in the pipelines. Several millions of dollars are being spent at the process site to dehydrate the blockage safely by using chemical inhibitors. We aim to establish national database, which addresses the physical conditions that promotes Qatari natural gas to form gas hydrates in the pipelines. Moreover, we aim to design and test novel hydrate inhibitors that are suitable for Qatari natural gas and its processing facilities. From these perspectives we are aiming to provide more effective and sustainable reservoir utilization and processing of Qatari natural gas. In this work, we present the initial findings of a QNRF funded project, which deals with the natural gas hydrate formation characteristics of Qatari type gas in both experimental (PVTx) and computational (molecular simulations) methods. We present the data from the two fully automated apparatus: a gas hydrate autoclave and a rocking cell. Hydrate equilibrium curves including growth/dissociation conditions for multi-component systems for several gas mixtures that represent Qatari type natural gas with and without the presence of well known kinetic and thermodynamic hydrate inhibitors. Ionic liquids were designed and used for testing their inhibition performance and their DFT and molecular modeling simulation results were also obtained and compared with the experimental results. Results showed significant performance of ionic liquids with up to 0.5 % in volume with up to 2 to 4 0C inhibition at high pressures.

Keywords: gas hydrates, natural gas, ionic liquids, inhibition, thermodynamic inhibitors, kinetic inhibitors

Procedia PDF Downloads 1290

Authors: Lormaine Anne A. Branzuela, Elysa V. Largo, Monet Concepcion M. Detras, Neil C. Concibido

Abstract:

The electricity demand is still increasing, and currently, the Philippine government is investigating the feasibility of operating the Bataan Nuclear Power Plant (BNPP) to address the country’s energy problem. However, the lack of process safety studies on BNPP focused on the effects of hazardous substances on the integrity of the structure, equipment, and other components, have made the plant operationalization questionable to the public. The three major nuclear power plant incidents – TMI-2, Chernobyl, and Fukushima – have made many people hesitant to include nuclear energy in the energy matrix. This study focused on the safety evaluation of possible operations of a nuclear power plant installed with a Pressurized Water Reactor (PWR), which is similar to BNPP. Failure Mode and Effects Analysis (FMEA) is one of the Process Hazard Analysis (PHA) techniques used for the identification of equipment failure modes and minimizing its consequences. Using the FMEA technique, this study was able to recognize 116 different failure modes in total. Upon computation and ranking of the risk priority number (RPN) and criticality rating (CR), it showed that failure of the reactor coolant pump due to earthquakes is the most critical failure mode. This hazard scenario could lead to a nuclear meltdown and radioactive release, as identified by the FMEA team. Safeguards and recommended risk reduction strategies to lower the RPN and CR were identified such that the effects are minimized, the likelihood of occurrence is reduced, and failure detection is improved.

Keywords: PHA, FMEA, nuclear power plant, bataan nuclear power plant

Procedia PDF Downloads 104

Authors: Barenten Suciu

Abstract:

In this work, effects of the friction and truncation on the dynamics of a double-cone gravitational motor, self-propelled on a straight V-shaped horizontal rail, are evaluated. Such mechanism has a variable radius of contact, and, on one hand, it is similar to a pulley mechanism that changes the potential energy into the kinetic energy of rotation, but on the other hand, it is similar to a pendulum mechanism that converts the potential energy of the suspended body into the kinetic energy of translation along a circular path. Movies of the self- propelled double-cones, made of S45C carbon steel and wood, along rails made of aluminum alloy, were shot for various opening angles of the rails. Kinematical features of the double-cones were estimated through the slow-motion processing of the recorded movies. Then, a kinematical model is derived under assumption that the distance traveled by the contact points on the rectilinear rails is identical with the distance traveled by the contact points on the truncated conical surface. Additionally, a dynamic model, for this particular contact problem, was proposed and validated against the experimental results. Based on such model, the traction force and the traction torque acting on the double-cone are identified. One proved that the rolling traction force is always smaller than the sliding friction force; i.e., the double-cone is rolling without slipping. Results obtained in this work can be used to achieve the proper design of such gravitational motor.

Keywords: Truncated double-cone, friction, rolling and sliding, dynamic model, gravitational motor

Procedia PDF Downloads 257

Authors: João Paulo Pascon

Abstract:

In this work, a mixed 3D finite element formulation is proposed in order to analyze thermoviscoplastic materials under large strain levels and ductile damage. To this end, a tetrahedral element of linear order is employed, considering a thermoviscoplastic constitutive law together with the neo-Hookean hyperelastic relationship and a nonlocal Gurson`s porous plasticity theory The material model is capable of reproducing finite deformations, elastoplastic behavior, void growth, nucleation and coalescence, thermal effects such as plastic work heating and conductivity, strain hardening and strain-rate dependence. The nonlocal character is introduced by means of a nonlocal parameter applied to the Laplacian of the porosity field. The element degrees of freedom are the nodal values of the deformed position, the temperature and the nonlocal porosity field. The internal variables are updated at the Gauss points according to the yield criterion and the evolution laws, including the yield stress of matrix, the equivalent plastic strain, the local porosity and the plastic components of the Cauchy-Green stretch tensor. Two problems involving 3D specimens and ductile damage are numerically analyzed with the developed computational code: the necking problem and a notched sample. The effect of the nonlocal parameter and the mesh refinement is investigated in detail. Results indicate the need of a proper nonlocal parameter. In addition, the numerical formulation can predict ductile fracture, based on the evolution of the fully damaged zone.

Keywords: mixed finite element, large strains, ductile damage, thermoviscoplasticity

Procedia PDF Downloads 70

Authors: Janet Ige, Paul Pilkington, Selena Gray, Jane Powell

Abstract:

Older adults from socially disadvantaged groups and Black and Minority Ethnic (BME) groups experience a higher burden of physical inactivity. Physical inactivity among BME groups is associated with the disproportionately higher level of health inequalities. People from minority ethnic groups encounter more barriers to physical activity. However, this is not often reported. There is very limited review-level evidence on the barriers and facilitators of physical activity among older adults from BME groups in the UK. This study aims to answer the following research question: what are the barriers and facilitators of physical activity participation among adults and older adults from BME background in the UK? To address this, we conducted a review of qualitative studies investigating the barriers and opportunities for physical activity among of BME adults and older adults in the UK. Method: This study is nested in an interpretive paradigm of meta-ethnography. A structured search for published literature was conducted on 6 electronic databases (MEDLINE, PsychINFO, Cumulative Index to Nursing & Allied Health Literature, Applied Social Sciences Index and Abstracts, Cochrane Database of Systematic Reviews, Allied and Complementary Medicine) from January 2007 to July 2017. Hand searching of the reference list of publications was performed in addition to a search conducted on Google Scholar to identify grey literature. Studies were eligible provided they employed any qualitative method and included participants identified as being BME, aged 50 and above, living in any community within the UK. In total, 1036 studies were identified from the structured search for literature, 718 studies were screened by titles after duplicates were removed. On applying the inclusion and exclusion criteria, a final selection of 10 studies was considered eligible for synthesis. Quality assessment was performed using the Critical Appraisal Skills Programme tool. Logic maps were used to show the relationship between factors that impact on physical activity participation among adults and older adults Result: Six key themes emerged from the data: awareness of the links between physical activity and health, interaction, and engagement with health professionals, cultural expectations and social responsibilities, appropriate environment, religious fatalism and practical challenges. Findings also showed that the barriers and facilitators of physical activity exist at the individual, community, and socio-economic, cultural and environmental level. There was a substantial gap in research among Black African groups. Findings from the review also informed the design of an ongoing survey investigating the experience and attitude of adults from Somali backgrounds towards physical activity in the UK. Conclusion: Identifying the barriers and facilitators of physical activity among BME groups is a crucial step in addressing the widening inequality gap. Findings from this study highlight the importance of engaging local BME residents in the design of exercise facilities within the community. This will ensure that cultural and social concerns are recognized and properly addressed.

Keywords: BME, UK, meta-ethnographic, adults

Procedia PDF Downloads 106

Authors: Rafeza Begum, Mohammad Mokhlesur Rahman, Safikul Moula, Rafiqul Islam

Abstract:

Potassium (K) is crucial for healthy soil and plant growth. However, K fertilization is either disregarded or poorly underutilized in Bangladesh agriculture, despite the great demand for crops. This could eventually result in a significant depletion of the soil's potassium reserves, irreversible alteration of the minerals that contain potassium, and detrimental effects on crop productivity. Soil K mining in Bangladesh is a worrying problem, and we need to evaluate it thoroughly and find remedies. A pot culture experiment was conducted in the greenhouse of Bangladesh Institute of Nuclear Agriculture (BINA) using eleven soil series of Bangladesh in order to see the depletion behaviour of potassium (K) by continuous cropping using rice (var. Iratom-24) as the test crop. The soil series were Ranishankhail, Kaonia. Sonatala, Silmondi, Gopalpur, Ishurdi, Sara, Kongsha, Nunni, Lauta and Amnura on which four successive rice plants (45 days duration) were raised with (100 ppm K) or without addition of potassium. Nitrogen, phosphorus, sulfur and zinc were applied as basal to all pots. Potassium application resulted in higher dry matter yield, increased K concentration and uptake in all the soils compared with no K treatment; which gradually decreased in the subsequent harvests. Furthermore, plant takes up K not only from exchangeable pool but also from non-exchangeable sites and a minimum replenishment of K from the soil reserve was observed. Continuous cropping has resulted in the depletion of available K of the soil. The result indicated that in order to sustain higher crop yield under intensive cultivation, the addition of potash fertilizer is necessary.

Keywords: potassium, exchangeable pool, depletion behavior., Soil series

Procedia PDF Downloads 98

Authors: H. Lahlali F. El Haouzi, A.M.Al-Baradi, I. El Aboudi, M. El Azhari, A. Mdarhri

Abstract:

Polytetrafluoroethylene (PTFE) is a high performance thermoplastic polymer with exceptional physical and chemical properties, such as a high melting temperature, high thermal stability, and very good chemical resistance. Nevertheless, manufacturing PTFE is problematic due to its high melt viscosity (10 12 Pa.s). In practice, it is by now well established that this property presents a serious problem when the classical methods are used to synthesized the dense PTFE materials in particularly hot pressing, high temperature extrusion. In this framework, we use here a new process namely spark plasma sintering (SPS) to elaborate PTFE samples from the micro metric particles powder. It consists in applying simultaneous electric current and pressure directly on the sample powder. By controlling the processing parameters of this technique, a series of PTFE samples are easy obtained and associated to remarkably short time as is reported in an early work. Our central goal in the present study is to understand how the non conventional SPS affects the mechanical properties at room temperature. For this end, a second commercially series of PTFE synthesized by using the extrusion method is investigated. The first data according to the tensile mechanical properties are found to be superior for the first set samples (SPS). However, this trend is not observed for the results obtained from the compression testing. The observed macro-behaviors are correlated to some physical properties of the two series of samples such as their crystallinity or density. Upon a close examination of these properties, we believe the SPS technique can be seen as a promising way to elaborate the polymer having high molecular mass without compromising their mechanical properties.

Keywords: PTFE, extrusion, Spark Plasma Sintering, physical properties, mechanical behavior

Procedia PDF Downloads 284

Authors: Brandon Ko

Abstract:

Whether it’s a kitchen staff or a law firm, many groups tend to have homogenous characteristics of race, gender, interests, and goals. Social groups are not typically random samples of the population and will usually have common identifiers. According to Blau, age, sex, and education all play salient roles in shaping relationships within members of society. So if there is some degree of homogeneity within groups, the question arises whether this is beneficial or harmful to a group’s effectiveness. There has been much disagreement in the scientific community as to whether the presence of homophily benefits or hinders an athletic team's cohesiveness. For this paper, a comparative study of research of soccer case studies that followed various, youth players was studied against examinations of the effects that such a culture has on athletes. The case studies were used as evidence to determine what kind of homophily existed within the soccer camps. One case study followed several European developmental clubs such as Bayern Munich and Barcelona. Another study followed eight different players, four of each gender, implementing a similar method of interviewing, observing, and questioning. The individual and team goals of each athlete were reviewed to see which teams and players were ego-oriented and which were team-oriented. Additionally, there had been little research done on the relationship between homophily and how it applies to the sport community, suggesting the need to develop this neglected problem in applied psychology. This paper argues that the benefits of an egalitarian culture and stronger relations with people of a similar socio-demographic outweigh the liabilities of cohesion like being stereotyped and a lack of network outside the group as produced by homophily in athletic competition.

Keywords: group cohesion, homophily, sports psychology, youth athletics

Procedia PDF Downloads 268

Authors: Mamoon M. Atout

Abstract:

The Middle East Gulf region has witnessed rapid growth and development in many areas over the last two decades. The development of the real-estate sector, construction industry and infrastructure projects are a major share of the development that has participated in the civilization of the countries of the Gulf. Construction industry projects were planned and managed by different types of experts, who came from all over the world having different types of experiences in construction management and industry. Some of these projects were completed on time, while many were not, due to many accumulating factors. Many accumulated factors are considered as the principle reason for the problem experienced at the project construction stage, which reflected negatively on the project success. Specific causes of delay have been identified by construction managers to avoid any unexpected delays through proper analysis and considerations to some implications such as risk assessment and analysis for many potential problems to ensure that projects will be delivered on time. Construction management implications were adopted and considered by project managers who have experience and knowledge in applying the techniques of the system of engineering construction management. The aim of this research is to determine the benefits of the implications of construction management by the construction team and level of considerations of the techniques and processes during the project development and construction phases to avoid any delay in the projects. It also aims to determine the factors that participate to project completion delays in case project managers are not well committed to their roles and responsibilities. The results of the analysis will determine the necessity of the applications required by the project team to avoid the causes of delays that help them deliver projects on time, e.g. verifying tender documents, quantities and preparing the construction method of the project.

Keywords: construction management, control process, cost control, planning and scheduling

Procedia PDF Downloads 225

Authors: M. Aghili, S. Tabarestani, C. Freytes, M. Shojaie, M. Cabrerizo, A. Barreto, N. Rishe, R. E. Curiel, D. Loewenstein, R. Duara, M. Adjouadi

Abstract:

A major challenge in medical studies, especially those that are longitudinal, is the problem of missing measurements which hinders the effective application of many machine learning algorithms. Furthermore, recent Alzheimer's Disease studies have focused on the delineation of Early Mild Cognitive Impairment (EMCI) and Late Mild Cognitive Impairment (LMCI) from cognitively normal controls (CN) which is essential for developing effective and early treatment methods. To address the aforementioned challenges, this paper explores the potential of using the eXtreme Gradient Boosting (XGBoost) algorithm in handling missing values in multiclass classification. We seek a generalized classification scheme where all prodromal stages of the disease are considered simultaneously in the classification and decision-making processes. Given the large number of subjects (1631) included in this study and in the presence of almost 28% missing values, we investigated the performance of XGBoost on the classification of the four classes of AD, NC, EMCI, and LMCI. Using 10-fold cross validation technique, XGBoost is shown to outperform other state-of-the-art classification algorithms by 3% in terms of accuracy and F-score. Our model achieved an accuracy of 80.52%, a precision of 80.62% and recall of 80.51%, supporting the more natural and promising multiclass classification.

Keywords: eXtreme gradient boosting, missing data, Alzheimer disease, early mild cognitive impairment, late mild cognitive impair, multiclass classification, ADNI, support vector machine, random forest

Procedia PDF Downloads 164

Authors: K. R. Mukuna

Abstract:

Teachers are faced many challenges in the South African rural schools such as stress, depression, lack of resources, poor working relationships, inflexible curriculum etc. These could affect their wellbeing and effectiveness at the workplace. As a result, the study had a significance in the teacher’s lives, and community due teachers worked under conditions that are unfavourable to perform their jobs effectively. Despite these conditions, they still managed to do their jobs and the community is uplifted. However, this study aimed to explore factors that enable teachers to cope with workplace adversities at a rural school district in the Free State Province. It adopted a qualitative case study as a research design. Semi-structured interviews and colleges had employed as tools to collect data. Ten participants (n=10; 5 males and 5 females) were selected through purposive and convenience sampling. All participants selected from a South African rural school. Sesotho culture was their home language, and most of them had 5 years of teaching experiences. The thematic findings revealed that they developed abilities to cope with and adjust to the social and cultural environment. These included self-efficacy, developing problem-solving skills, awareness of strengths and asserts, self-managing of emotions, and self-confidence. This study concluded that these psychosocial factors contributed to coping with teacher’s diversities, and effectively stabilized their wellbeing in the schools.

Keywords: psychosocial factors, teachers counselling, teacher stress, workplace adversity, rural school, teachers’ wellbeing, teachers’ resilience, teachers’ self-efficacy, social interaction

Procedia PDF Downloads 110

Authors: Ibrahim A. Alhammad, Suleiman A. Al-Otaibi, Khalid S. Al-Gahtani, Naïf Al-Otaibi, Abdulaziz A. Bubshait

Abstract:

In the last decade, the use of project delivery system of design build engineering contracts is increasing in North America due to the reasons of reducing the project duration and minimizing costs. The shift from traditional approach of Design-Bid-Build to Design-Build contracts have been attributed to many factors such as evolution of the regulatory and legal frameworks governing the engineering contracts and improvement in integrating design and construction. The aforementioned practice of contracting is more appropriate in North America; yet, it may not be the case in Saudi Arabia where the traditional approach of construction contracting remains dominant. The authors believe there are number of factors related to the gaps in the level of sophistication of the engineering and management of the construction projects in both countries. A step towards improving the Saudi construction practice by adopting the new trend of construction contracting, this paper identifies the reasons why Design/Build form of contracting are not frequently utilized. A field survey, which includes the questionnaire addressing the research problem, is distributed to three main parties of the construction contracts: clients, consultants, and contractors. The analyzed collected data were statistically sufficient to finding the reasons of not adopting the new trend of good practice of deign build approach in Saudi Arabia. In addition, the reasons are: (1) lack of regulation and legal framework; (2) absence of clear criteria of the owner for the trade-off between competing contractors, (3) and lack of experience, knowledge and skill.

Keywords: design built projects, Saudi Arabia, GCC, mega projects

Procedia PDF Downloads 204

Authors: Shehu A. Salau, Robiu O. Aliu, Nofiu B. Nofiu

Abstract:

Nigeria is among countries of the world confronted with food insecurity problem. The agricultural production systems that produces food for the teaming population is not endurable. Attention is thus being given to alternative approaches of intensification such as the use of Sustainable Land Management (SLM) technologies. Thus, this study assessed the effect of SLM technologies on food security of farming households in Kwara State, Nigeria. A-three stage sampling technique was used to select a sample of 200 farming households for this study. Descriptive statistics, Shriar index, Likert scale, food security index and logistic regression were employed for the analysis. The result indicated that majority (41%) of the household heads were between the ages of 51 and 70 years with an average of 60.5 years. Food security index revealed that 35% and 65% of the households were food secure and food insecure respectively. The logistic regression showed that SLM technologies, estimated income, household size, gender and age of the household heads were the critical determinants of food security among farming households. The most effective coping strategies adopted by households geared towards lessening the effects of food insecurity are reduced quality of food consumed, employed off-farm jobs to raise household income and diversion of money budgeted for other uses to purchase foods. Governments should encourage the adoption and use of SLM technologies at all levels. Policies and strategies that reduce household size should be enthusiastically pursued to reduce food insecurity.

Keywords: agricultural practices, coping strategies, farming households, food security, SLM technologies, logistic regression

Procedia PDF Downloads 152

Authors: Khalid M. Albarkoly, Kenneth S. Park

Abstract:

The substantial development of the construction industry has forced the cement industry, its major support, to focus on achieving maximum productivity to meet the growing demand for this material. Statistics indicate that the demand for cement rose from 1.6 billion metric tons (bmt) in 2000 to 4bmt in 2013. This means that the reliability of a production system needs to be at the highest level that can be achieved by good maintenance. This paper studies the extent to which the implementation of RCM is needed as a strategy for increasing the reliability of the production systems component can be increased, thus ensuring continuous productivity. In a case study of four Libyan cement factories, 80 employees were surveyed and 12 top and middle managers interviewed. It is evident that these factories usually breakdown more often than once per month which has led to a decline in productivity, they cannot produce more than 50% of their designed capacity. This has resulted from the poor reliability of their production systems as a result of poor or insufficient maintenance. It has been found that most of the factories’ employees misunderstand maintenance and its importance. The main cause of this problem is the lack of qualified and trained staff, but in addition, it has been found that most employees are not found to be motivated as a result of a lack of management support and interest. In response to these findings, it has been suggested that the RCM strategy should be implemented in the four factories. The paper shows the importance of considering the development of maintenance strategies through the implementation of RCM in these factories. The purpose of it would be to overcome the problems that could reduce the level of reliability of the production systems. This study could be a useful source of information for academic researchers and the industrial organisations which are still experiencing problems in maintenance practices.

Keywords: Libyan cement industry, reliability centred maintenance, maintenance, production, reliability

Procedia PDF Downloads 370

Authors: Hasibe Caballero-Gomez, Richard Pepino

Abstract:

Childhood lead poisoning is an issue that continues to plague major U.S. cities. Lead poisoning has been linked to decreases in academic achievement and IQ at levels as low as 5 ug/dL. Despite efforts from the Philadelphia Health Department to curtail systemic childhood lead poisoning, children continue to be identified with elevated blood lead levels (EBLLs) above the CDC reference level for diagnosis. This problem disproportionately affects low-income Black communities. At the moment, remediation is costly, and with the current policies in place, comprehensive remediation seems unrealistic. This research investigates community engagement policy and the ways pre-exisiting resources in target communities can be adjusted to decrease childhood lead poisoning. The study was done with two methods: content analysis and case studies. The content analysis includes 12 interviews from stakeholders and five published policy recommendations. The case studies focus on Baltimore, Chicago, Rochester, and St. Louis, four cities with significant childhood lead poisoning. Target communities were identified by mapping five factors that indicate a higher risk for lead poisoning. Seven priority zipcodes were identified for the model developed in this study. For these urban centers, 28 policy solutions and suggestions were identified, with three being identified at least four times in the content analysis and case studies. These three solutions create an interdependent model that offers increased community awareness and engagement with the issue that could potentially improve health and social outcomes for at-risk children.

Keywords: at-risk populations, community engagement, environmental justice, policy translation

Procedia PDF Downloads 97

Authors: Seyed Mohammad Hashemi, Shahrokh Barati

Abstract:

The problem of fault-tolerant control (FTC) by accommodation method has been studied in this paper. The fault occurs in any system components such as actuators, sensors or internal structure of the system and leads to loss of performance and instability of the system. When a fault occurs, the purpose of the fault-tolerant control is designate strategy that can keep the control loop stable and system performance as much as possible perform it without shutting down the system. Here, the section of fault detection and isolation (FDI) system has been evaluated with regard to actuator's fault. Designing a fault detection and isolation system for a multi input-multi output (MIMO) is done by an unknown input observer, so the system is divided to several subsystems as the effect of other inputs such as disturbing given system state equations. In this observer design method, the effect of these disturbances will weaken and the only fault is detected on specific input. The results of this approach simulation can confirm the ability of the fault detection and isolation system design. After fault detection and isolation, it is necessary to redesign controller based on a suitable modification. In this regard after the use of unknown input observer theory and obtain residual signal and evaluate it, PID controller parameters redesigned for iterative. Stability of the closed loop system has proved in the presence of this method. Also, In order to soften the volatility caused by Annie variations of the PID controller parameters, modifying Sigma as a way acceptable solution used. Finally, the simulation results of three tank popular example confirm the accuracy of performance.

Keywords: fault tolerant control, fault detection and isolation, actuator fault, unknown input observer

Procedia PDF Downloads 432

Authors: Mayesha Tahsin, A.S. Mollah

Abstract:

Recently, a 1.5x1.5 inch NaI(Tl) detector based gamma-ray spectroscopy system has been installed in the laboratory of the Nuclear Science and Engineering Department of the Military Institute of Science and Technology for radioactivity detection purposes. The newly installed NaI(Tl) detector has a circular lead shield of 22 mm width. An important consideration of any gamma-ray spectroscopy is the minimization of natural background radiation not originating from the radioactive sample that is being measured. Natural background gamma-ray radiation comes from naturally occurring or man-made radionuclides in the environment or from cosmic sources. Moreover, the main problem with this system is that it is not suitable for measurements of radioactivity with a large sample container like Petridish or Marinelli beaker geometry. When any laboratory installs a new detector or/and new shield, it “must” first carry out quality and performance tests for the detector and shield. This paper describes a new portable shielding system with lead that can reduce the background radiation. Intensity of gamma radiation after passing the shielding will be calculated using shielding equation I=Ioe-µx where Io is initial intensity of the gamma source, I is intensity after passing through the shield, µ is linear attenuation coefficient of the shielding material, and x is the thickness of the shielding material. The height and width of the shielding will be selected in order to accommodate the large sample container. The detector will be surrounded by a 4π-geometry low activity lead shield. An additional 1.5 mm thick shield of tin and 1 mm thick shield of copper covering the inner part of the lead shielding will be added in order to remove the presence of characteristic X-rays from the lead shield.

Keywords: shield, NaI (Tl) detector, gamma radiation, intensity, linear attenuation coefficient

Procedia PDF Downloads 135

Authors: Ekroop Singh Sethi, Arshnoor Kaur, M. H. Bharath

Abstract:

India is the fastest growing economy and a land of tradition, culture and realm of 19 % of the world’s children. Children are an essential part of any economy as its future GDP contributors and, therefore, it is the duty of a country to take care of its future wealth providers. Each country has its own way of child welfare. India is a developing country, has its own child welfare schemes in place, but the question is, are they really as effective as they seem? Are the schemes sufficient? And what about implementation? With 41% of the population below the age of 18, questions relating to child education and welfare require focus. Right to education is a significant act of the government of India that explains the roadmap of free and compulsory elementary education for children in India, making the India 135th country to bring education as right, involving proper support from the government to overcome the shadow of economic conditions and status which prevents children to learn and grow. But is right to education a children-centric movement? As faces the major problem of well-planned, practical curriculum and facilitators, as only 40% of grade 5 students could barely read the textbook of grade 2. Is the policy worthy of settling the child or still trapped in negative realities of the competitive environment of private VS government schools. From the steps to encouragement from the pupil's home to enlightening centers, the article focuses on level of execution, impact and difference in terms to contributing and enabling the children of India for a better tomorrow and a solution to multilayered problems of elementary education in India.

Keywords: growing economy, child welfare, right to education, elementary education, private vs government schools, pupil's home, enlightening centers, execution, impact

Procedia PDF Downloads 217

Authors: Shashank Gahlaut, Chandrashekhar Sharan, J. P. Singh

Abstract:

Increasing incidence of antibiotic-resistant bacteria is a big concern for the treatment of pathogenic diseases. The effect of treatment of patients with antibiotics often leads to the evolution of antibiotic resistance in the pathogens. The detection of antibiotic or antimicrobial resistant bacteria (microbes) is quite essential as it is becoming one of the big threats globally. Here we propose a novel technique to tackle this problem. We are taking a step forward to prevent the infections and diseases due to drug resistant microbes. This detection is based on some unique features of silver (a noble metal) nanorods (AgNRs) which are fabricated by a physical deposition method called thermal glancing angle deposition (GLAD). Silver nanorods are found to be highly sensitive and selective for hydrogen sulfide (H2S) gas. Color and water wetting (contact angle) of AgNRs are two parameters what are effected in the presence of this gas. H₂S is one of the major gaseous products evolved in the bacterial metabolic process. It is also known as gasotransmitter that transmits some biological singles in living systems. Nitric Oxide (NO) and Carbon mono oxide (CO) are two another members of this family. Orlowski (1895) observed the emission of H₂S by the bacteria for the first time. Most of the microorganism produce these gases. Here we are focusing on H₂S gas evolution to determine live/dead and antibiotic-resistant bacteria. AgNRs array has been used for the detection of H₂S from micro-organisms. A mobile app is also developed to make it easy, portable, user-friendly, and cost-effective.

Keywords: antibiotic resistance, hydrogen sulfide, live and dead bacteria, mobile app

Procedia PDF Downloads 123

Authors: Lingyu Ding, Hongxia Hua, Hanfei Zhu, Jinling Lu, Qin Xu

Abstract:

Background: Postoperative pain is a prevalent problem leading to many adverse outcomes in surgical patients. Virtual reality (VR) is an emerging non-pharmacological method of postoperative pain relief, but the effects of it are not clear. This review aimed to explore the effects of VR on relieving postoperative pain. Methods: We searched PubMed, Embase, Web of Science, and other databases from inception to November 2019 to get the eligible studies. Meta-analyses were conducted to compare VR and usual care for relieving postoperative pain. Subgroup analyses and sensitivity analyses were performed to explain the heterogeneity. Results: Overall, 8 randomized control trials (RCTs) enrolling 723 participants were included. Our results demonstrated that the patients receiving the VR intervention had lower postoperative pain scores than those receiving the usual care. One subgroup analysis revealed that VR could relieve postoperative pain both in minor surgery and major surgery. Another subgroup analysis demonstrated a significant reduction in postoperative pain among patients receiving VR during the intraoperative and the postoperative periods. However, there was no significant postoperative pain relief when receiving VR during the preoperative period. Additionally, significant improvements in postoperative satisfaction were reported in two studies. However, another two studies included found that VR could not affect physiological parameters related to pain. Conclusion: Applying VR can relieve postoperative pain effectively. The type of surgery and timing of using VR are the main sources of heterogeneity. More rigorous studies about the relationship between VR and postoperative pain relief will be needed.

Keywords: meta-analysis, postoperative pain, systematic review, virtual reality

Procedia PDF Downloads 116