Search results for: tragedies study
14147 Progressive Type-I Interval Censoring with Binomial Removal-Estimation and Its Properties
Authors: Sonal Budhiraja, Biswabrata Pradhan
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This work considers statistical inference based on progressive Type-I interval censored data with random removal. The scheme of progressive Type-I interval censoring with random removal can be described as follows. Suppose n identical items are placed on a test at time T0 = 0 under k pre-fixed inspection times at pre-specified times T1 < T2 < . . . < Tk, where Tk is the scheduled termination time of the experiment. At inspection time Ti, Ri of the remaining surviving units Si, are randomly removed from the experiment. The removal follows a binomial distribution with parameters Si and pi for i = 1, . . . , k, with pk = 1. In this censoring scheme, the number of failures in different inspection intervals and the number of randomly removed items at pre-specified inspection times are observed. Asymptotic properties of the maximum likelihood estimators (MLEs) are established under some regularity conditions. A β-content γ-level tolerance interval (TI) is determined for two parameters Weibull lifetime model using the asymptotic properties of MLEs. The minimum sample size required to achieve the desired β-content γ-level TI is determined. The performance of the MLEs and TI is studied via simulation.Keywords: asymptotic normality, consistency, regularity conditions, simulation study, tolerance interval
Procedia PDF Downloads 23714146 The Scattering in Flexible Reactive Silencer Containing Rigid Partitioning
Authors: Muhammad Afzal, Junaid Uzair Satti
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The noise emanating from the ducting of heating, ventilation, and air-conditioning (HVAC) system is often attenuated by using the dissipative silencers. Such devices work well for the high-frequency noise but are less operative in the low-frequency noise range. The present study analyzes a reactive silencer comprising expansion chamber of the elastic membranes partitioned symmetrically by a rigid plate. The Mode-Matching scheme has been developed to solve the governing boundary value problem. The orthogonal and non-orthogonal duct modes of acoustic pressures and normal velocities are matched at interfaces. It enables to recast the differential system into the infinite system of linear algebraic of equations, which is, then truncated and inverted for the solution. The truncated solution is validated through the conservation of energy and reconstruction of matching conditions. The results for scattering energy flux and transmission loss are shown against frequency and the dimensions of the chamber. It is seen that the stop-band of the silencer can be shifted to the broadband by changing the dimensions of the chamber and the properties of the elastic membranes. The modeled reactive silencer is more efficient in low frequency regime where the passive devices are least effective.Keywords: acoustic scattering, elastic membranes mode-matching, reactive silencer
Procedia PDF Downloads 14214145 Evaluating Portfolio Performance by Highlighting Network Property and the Sharpe Ratio in the Stock Market
Authors: Zahra Hatami, Hesham Ali, David Volkman
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Selecting a portfolio for investing is a crucial decision for individuals and legal entities. In the last two decades, with economic globalization, a stream of financial innovations has rushed to the aid of financial institutions. The importance of selecting stocks for the portfolio is always a challenging task for investors. This study aims to create a financial network to identify optimal portfolios using network centralities metrics. This research presents a community detection technique of superior stocks that can be described as an optimal stock portfolio to be used by investors. By using the advantages of a network and its property in extracted communities, a group of stocks was selected for each of the various time periods. The performance of the optimal portfolios compared to the famous index. Their Sharpe ratio was calculated in a timely manner to evaluate their profit for making decisions. The analysis shows that the selected potential portfolio from stocks with low centrality measurement can outperform the market; however, they have a lower Sharpe ratio than stocks with high centrality scores. In other words, stocks with low centralities could outperform the S&P500 yet have a lower Sharpe ratio than high central stocks.Keywords: portfolio management performance, network analysis, centrality measurements, Sharpe ratio
Procedia PDF Downloads 14414144 Challenges Being Faced by Students of Arabic and Islamic Studies in Tetiary Institutions in Nigeria: Case Study of Some Selected Tetiary Instutions of Yobe State, Nigeria
Authors: Muhammad Alhaji Maidugu
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The role played by Arabic and Islamic Studies in the history of Nigeria - particularly Northern part of the country - cannot be overemphasized. Before the British colonialism, Arabic language was the official language in some of the great empires in Nigeria such as the Kanem Borno Empire. Islam, on the other hand, is the state religion. Both the rulers and the ruled were deeply involved in the pursuit of Arabic and Islamic knowledge traveling as far as Egypt, Saudia Arabia for scholarship. Their homes are like a modern library where Islamic books are kept and used to teach the community the different fields of Arabic and Islamic Studies. Scholars of Arabic and Islamic Studies were highly regarded and well respected in the society as they were the decision makers, diplomats and advisers to the authorities. Unfortunately, the colonizers used their influence and force to replace this language with a foreign language. In fact, they tried to exterminate it. Arabic became less important in the country. Arabic and Islamic Students became less significant and anybody studying Arabic or Islamic Studies is looked down at with disdain, and the course is considered unprofessional. This paper aims at casting a glance in the position of Arabic and Islamic Studies in Yobe State, Nigeria and social, political, economical and moral challenges faced by the students at institutions of learning.Keywords: challenges, students of Arabic and Islamic studies, tertiary, institutions, Yobe
Procedia PDF Downloads 35114143 Integrating Wound Location Data with Deep Learning for Improved Wound Classification
Authors: Mouli Banga, Chaya Ravindra
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Wound classification is a crucial step in wound diagnosis. An effective classifier can aid wound specialists in identifying wound types with reduced financial and time investments, facilitating the determination of optimal treatment procedures. This study presents a deep neural network-based classifier that leverages wound images and their corresponding locations to categorize wounds into various classes, such as diabetic, pressure, surgical, and venous ulcers. By incorporating a developed body map, the process of tagging wound locations is significantly enhanced, providing healthcare specialists with a more efficient tool for wound analysis. We conducted a comparative analysis between two prominent convolutional neural network models, ResNet50 and MobileNetV2, utilizing a dataset of 730 images. Our findings reveal that the RestNet50 outperforms MovileNetV2, achieving an accuracy of approximately 90%, compared to MobileNetV2’s 83%. This disparity highlights the superior capability of ResNet50 in the context of this dataset. The results underscore the potential of integrating deep learning with spatial data to improve the precision and efficiency of wound diagnosis, ultimately contributing to better patient outcomes and reducing healthcare costs.Keywords: wound classification, MobileNetV2, ResNet50, multimodel
Procedia PDF Downloads 1514142 Basic Aspects and Ecology of a Group of Capuchin Monkeys (Cebus spp.) (Primates: Cebidae) and Frequency of Contact with Visitor of the State Park Alberto Lofgren, Sao Paulo, Brazil
Authors: Luma Vaz, Marcio Port-Carvalho
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The main objective of this research was to study the basics aspects of the ecology of a group of capuchin monkeys (Cebus spp.), evaluating the risks that habit and food that is given by the visitors may cause to the people's health and animals welfare, also how to make proposals for mitigation and management guidelines. In order to do that, some aspects of the animal's ecology (such as diet, habitat range and habitat use) and activity patterns were studied. It was also measured the frequency of contact with visitors at the park using protocols for data collection. The behavioral categories of displacement and resting represent more than 80% of total activities, followed by feeding (13%) and others (6%). When compared to the studies in natural environment, the Cebus group studied has a small living area (1.7ha) occupying mostly the PEAL public area. The diversity of items offered by the visitors and the high frequency of contact closer than one meter suggests that using information and education campaigns must be a priority in the public program in PEAL in order to avoid future accidents and diseases transmissions.Keywords: capuchin monkeys, Cebus, environmental education, public health, wildlife management
Procedia PDF Downloads 13314141 Influence of Chemical Pollution on Thermal Habitats of the Ciliate Tetrahymena thermophila
Authors: Doufoungognon C. Kone
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Global change, in particular pollution and global warming, threatens ecosystems and the biodiversity they harbor. Due to pollutants exposure, organisms might modify their thermal niches in order to track the thermal conditions limiting the negative impacts of chemical stressors depending on their mode of action. This study tests the influence of different pollutants, copper, salt, and chloramphenicol, on the thermal preferences of the ciliate Tetrahymena thermophila. Six genotypes were exposed to a gradient of concentrations ranging from 0 to 500mg/L for copper, 0 to 300 mg/l for chloramphenicol, and 0 to 12g/l for salt in synthetic media at eight temperatures ranging from 11 to 39° C. The measured fitness proxies are the maximum growth rate and the 50% growth inhibitory concentration (IC50). The results show that the majority of genotypes are more resistant to chloramphenicol in temperatures below their thermal optimum without pollutants, while they better tolerate other salt and copper in temperatures above their thermal optimum. In addition, generalists reduce their niche width while specialists widen it in chloramphenicol. Overall, results suggest that global warming would have a particularly deleterious effect in the case of chemical pollution. This pollution would induce the full disruption of the thermal habitats.Keywords: ciliate, thermal niche, growth rate, toxicity, multiple stressors
Procedia PDF Downloads 8514140 Prevelance of Green Peach Aphid (Myzus persicae) in District Jacobabad, Sindh, Pakistran
Authors: Kamal Khan Abro, Nasreen Memon, Attaullah Ansari, Mahpara Pirzada, Saima Pathan
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Jacobabad district has a hot desert climate with very hot summers and insignificant winters. The highest recorded temperature is 53.8 °C (127.0 °F), and the lowest recorded temperature is −4.9 °C (25.0 °F). Rainfall is short and mostly occurs in the monsoon season (July–September). Agriculture point of view Jacobabad district is very important district of Sindh Pakistan in which many types of crop and vegetables are cultivated annually such as Wheat, Rice, and Brassica, Cabbage, Spinach, Chili etc. which are badly attacked by many crops pest. Insects are very tiny, sensitive and most attractive mortal and most important collection of animal wildlife they play important role in biological control agent, biodiversity & agroecosystem. The brassica crop extremely infested by many different types of pest such as Aphids, Whitefly, Jassids, Thrips, Mealybug, scale insect pink worm, bollworm and borers Mealy bug, scale insect etc. These pests destroy many crops. The present study was carried out from Jacobabad district from January 2017 to April 2017.Keywords: prevelance, green peach aphid, Jacobabad, Sindh Pakistan
Procedia PDF Downloads 28014139 A Study on the False Alarm Rates of MEWMA and MCUSUM Control Charts When the Parameters Are Estimated
Authors: Umar Farouk Abbas, Danjuma Mustapha, Hamisu Idi
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It is now a known fact that quality is an important issue in manufacturing industries. A control chart is an integrated and powerful tool in statistical process control (SPC). The mean µ and standard deviation σ parameters are estimated. In general, the multivariate exponentially weighted moving average (MEWMA) and multivariate cumulative sum (MCUSUM) are used in the detection of small shifts in joint monitoring of several correlated variables; the charts used information from past data which makes them sensitive to small shifts. The aim of the paper is to compare the performance of Shewhart xbar, MEWMA, and MCUSUM control charts in terms of their false rates when parameters are estimated with autocorrelation. A simulation was conducted in R software to generate the average run length (ARL) values of each of the charts. After the analysis, the results show that a comparison of the false alarm rates of the charts shows that MEWMA chart has lower false alarm rates than the MCUSUM chart at various levels of parameter estimated to the number of ARL0 (in control) values. Also noticed was that the sample size has an advert effect on the false alarm of the control charts.Keywords: average run length, MCUSUM chart, MEWMA chart, false alarm rate, parameter estimation, simulation
Procedia PDF Downloads 20814138 The Role of Homocysteine in Bone and Cartilage Regeneration
Authors: Arif İsmailov, Naila Hasanova, Gunay Orujalieva
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Homocysteine (HCY) is an indicator of prognostic value in monitoring regenerative processes in osteoporosis and osteoporotic fractures. The osteoporosis is known to be a serious health and economic problem, especially for women in the postmenopausal period. The study was carried out on patients 45-83 years old divided into 3 groups: group I – 14 patients with osteoporosis , group II – 15 patients with non-osteoporotic fractures, group III – 25 patients with osteoporotic fractures. The control group consisted of practically healthy 14 people. A blood sample was taken at 3 stages to monitor the dynamics of HCY level: on the 1st day before treatment, on the 10th day of treatment and 1 month after it. Blood levels of Hcy were determined at a wavelength of 450 nm by the ELİSA(Cloud Clone Corp.Elisa kits,USA). The statistical evaluation was performed by using SPSS 26.0 program (IBM SPSS Inc., USA).The results showed that on the 1st day before the treatment HCY concentration was statistically increased 2.7 times(PU = 0.108) in group I, 5.6 times (PU <0.001) in group II and 6.5 times (PU <0.001) in group III compared to the control group. Thus, the average value of HCY in group I was 1.76 ± 0.56 μg/ml; in group II – 3.57 ± 0.62 μg/ml; in group III – 4.2 ± 0.50 μg/ml. HCY level increases more sharply after fractures,especially in osteoporotic patients. In treatment period Vitamin D plays an important role in synthesis of the Cystathionine β‐synthase enzyme, which regulates HCY metabolism. Increased Hcy levels could lead to an increase in the risk of fracture through the interference in collagen cross-linking.Keywords: homocysteine, osteoporosis, osteoporotic fractures, Vitamin D
Procedia PDF Downloads 5014137 Harnessing Nigeria's Forestry Potential for Structural Applications: Structural Reliability of Nigerian Grown Opepe Timber
Authors: J. I. Aguwa, S. Sadiku, M. Abdullahi
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This study examined the structural reliability of the Nigerian grown Opepe timber as bridge beam material. The strength of a particular specie of timber depends so much on some factors such as soil and environment in which it is grown. The steps involved are collection of the Opepe timber samples, seasoning/preparation of the test specimens, determination of the strength properties/statistical analysis, development of a computer programme in FORTRAN language and finally structural reliability analysis using FORM 5 software. The result revealed that the Nigerian grown Opepe is a reliable and durable structural bridge beam material for span of 5000mm, depth of 400mm, breadth of 250mm and end bearing length of 150mm. The probabilities of failure in bending parallel to the grain, compression perpendicular to the grain, shear parallel to the grain and deflection are 1.61 x 10-7, 1.43 x 10-8, 1.93 x 10-4 and 1.51 x 10-15 respectively. The paper recommends establishment of Opepe plantation in various Local Government Areas in Nigeria for structural applications such as in bridges, railway sleepers, generation of income to the nation as well as creating employment for the numerous unemployed youths.Keywords: bending and deflection, bridge beam, compression, Nigerian Opepe, shear, structural reliability
Procedia PDF Downloads 45414136 Is Privatization Related with Macroeconomic Management? Evidence from Some Selected African Countries
Authors: E. O. George, P. Ojeaga, D. Odejimi, O. Mattehws
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Has macroeconomic management succeeded in making privatization promote growth in Africa? What are the probable strategies that should accompany the privatization reform process to promote growth in Africa? To what extent has the privatization process succeeded in attracting foreign direct investment to Africa? The study investigates the relationship between macroeconomic management and privatization. Many African countries have embarked on one form of privatization reform or the other since 1980 as one of the stringent conditions for accessing capital from the IMF and the World Bank. Secondly globalization and the gradually integration of the African economy into the global economy also means that Africa has to strategically develop its domestic market to cushion itself from fluctuations and probable contagion associated with global economic crisis that are always inevitable Stiglitz. The methods of estimation used are the OLS, linear mixed effects (LME), 2SLS and the GMM method of estimation. It was found that macroeconomic management has the capacity to affect the success of the privatization reform process. It was also found that privatization was not promoting growth in Africa; privatization could promote growth if long run growth strategies are implemented together with the privatization reform process. Privatization was also found not to have the capacity to attract foreign investment to many African countries.Keywords: Africa, political economy, game theory, macroeconomic management and privatization
Procedia PDF Downloads 32314135 Comparison of Food Products Contaminated by DDTs in South Africa and Mozambique
Authors: Lesa A. Thompson, Yoshinori Ikenaka, Victor Wepener, Mayumi Ishizuka
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One method for controlling malaria in endemic regions is the killing of vector mosquitoes using pesticides such as DDT in indoor residual spraying (IRS). This study was carried out to investigate the presence of and human health risk due to DDT and its metabolites (collectively, DDTs) contaminating human food sources in areas where DDT is used for IRS. Free-range chicken products (meat and eggs) were collected from homesteads in KwaZulu-Natal Province in the northeast of South Africa, and fish meat samples from Maputo Bay in neighbouring Mozambique. Samples were analysed for DDTs (o,p’-DDT, p,p’-DDT, o,p’-DDD, p,p’-DDD, o,p’-DDE and p,p’-DDE) using a gas chromatograph with electron capture detector (GC-ECD). DDTs were detected in all food types, with the predominant congener being p,p’-DDE. The presence of p,p’-DDT confirmed recent release of DDT into the environment. By using concentration levels detected in foods and national consumption levels, the risk to human health through consumption of such food products was calculated. In order of risk level, these were: chicken eggs > chicken meat > fish meat. Human risk (carcinogenic) values greater than one suggest there is an increased health risk through consumption of these foods.Keywords: DDT, food contamination, human health risk, Mozambique, South Africa
Procedia PDF Downloads 33414134 Ambient Vibration Testing of Existing Buildings in Madinah
Authors: Tarek M. Alguhane, Ayman H. Khalil, M. N. Fayed, Ayman M. Ismail
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The elastic period has a primary role in the seismic assessment of buildings. Reliable calculations and/or estimates of the fundamental frequency of a building and its site are essential during analysis and design process. Various code formulas based on empirical data are generally used to estimate the fundamental frequency of a structure. For existing structures, in addition to code formulas and available analytical tools such as modal analyses, various methods of testing including ambient and forced vibration testing procedures may be used to determine dynamic characteristics. In this study, the dynamic properties of the 32 buildings located in the Madinah of Saudi Arabia were identified using ambient motions recorded at several, spatially-distributed locations within each building. Ambient vibration measurements of buildings have been analyzed and the fundamental longitudinal and transverse periods for all tested buildings are presented. The fundamental mode of vibration has been compared in plots with codes formulae (Saudi Building Code, EC8, and UBC1997). The results indicate that measured periods of existing buildings are shorter than that given by most empirical code formulas. Recommendations are given based on the common design and construction practice in Madinah city.Keywords: ambient vibration, fundamental period, RC buildings, infill walls
Procedia PDF Downloads 25614133 Preliminary Studies of MWCNT/PVDF Polymer Composites
Authors: Esther Lorrayne M. Pereira, Adriana Souza M. Batista, Fabíola A. S. Ribeiro, Adelina P. Santos, Clascídia A. Furtado, Luiz O. Faria
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The combination of multi–walled carbon nanotubes (MWCNTs) with polymers offers an attractive route to reinforce the macromolecular compounds as well as the introduction of new properties based on morphological modifications or electronic interactions between the two constituents. As they are only a few nanometers in dimension, it offers ultra-large interfacial area per volume between the nano-element and polymer matrix. Nevertheless, the use of MWCNTs as a rough material in different applications has been largely limited by their poor processability, insolubility, and infusibility. Studies concerning the nanofiller reinforced polymer composites are justified in an attempt to overcome these limitations. This work presents one preliminary study of MWCNTs dispersion into the PVDF homopolymer. For preparation, the composite components were diluted in n,n-dimethylacetamide (DMAc) with mechanical agitation assistance. After complete dilution, followed by slow evaporation of the solvent at 60°C, the samples were dried. Films of about 80 μm were obtained. FTIR and UV-Vis spectroscopic techniques were used to characterize the nanocomposites. The appearance of absorption bands in the FTIR spectra of nanofilled samples, when compared to the spectrum of pristine PVDF samples, are discussed and compared with the UV-Vis measurements.Keywords: composites materials, FTIR, MWNTs, PVDF, UV-vis
Procedia PDF Downloads 44214132 Surface Roughness Formed during Hybrid Turning of Inconel Alloy
Authors: Pawel Twardowski, Tadeusz Chwalczuk, Szymon Wojciechowski
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Inconel 718 is a material characterized by the unique mechanical properties, high temperature strength, high thermal conductivity and the corrosion resistance. However, these features affect the low machinability of this material, which is usually manifested by the intense tool wear and low surface finish. Therefore, this paper is focused on the evaluation of surface roughness during hybrid machining of Inconel 718. The primary aim of the study was to determine the relations between the vibrations generated during hybrid turning and the formed surface roughness. Moreover, the comparison of tested machining techniques in terms of vibrations, tool wear and surface roughness has been made. The conducted tests included the face turning of Inconel 718 with laser assistance in the range of variable cutting speeds. The surface roughness was inspected with the application of stylus profile meter and accelerations of vibrations were measured with the use of three-component piezoelectric accelerometer. The carried out research shows that application of laser assisted machining can contribute to the reduction of surface roughness and cutting vibrations, in comparison to conventional turning. Moreover, the obtained results enable the selection of effective cutting speed allowing the improvement of surface finish and cutting dynamics.Keywords: hybrid machining, nickel alloys, surface roughness, turning, vibrations
Procedia PDF Downloads 32014131 Empirical Green’s Function Technique for Accelerogram Synthesis: The Problem of the Use for Marine Seismic Hazard Assessment
Authors: Artem A. Krylov
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Instrumental seismological researches in water areas are complicated and expensive, that leads to the lack of strong motion records in most offshore regions. In the same time the number of offshore industrial infrastructure objects, such as oil rigs, subsea pipelines, is constantly increasing. The empirical Green’s function technique proved to be very effective for accelerograms synthesis under the conditions of poorly described seismic wave propagation medium. But the selection of suitable small earthquake record in offshore regions as an empirical Green’s function is a problem because of short seafloor instrumental seismological investigation results usually with weak micro-earthquakes recordings. An approach based on moving average smoothing in the frequency domain is presented for preliminary processing of weak micro-earthquake records before using it as empirical Green’s function. The method results in significant waveform correction for modeled event. The case study for 2009 L’Aquila earthquake was used to demonstrate the suitability of the method. This work was supported by the Russian Foundation of Basic Research (project № 18-35-00474 mol_a).Keywords: accelerogram synthesis, empirical Green's function, marine seismology, microearthquakes
Procedia PDF Downloads 31914130 Experimental and Analytical Study of Various Types of Shear Connector Used for Cold-Formed Steel-Ferrocement Composite Beam
Authors: Talal Alhajri, Mahmood M. Tahir, Khaled Alenezi, Mohamad Ragaee
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This work presents the experimental tests carried out to evaluate the behaviour of different types of shear connectors proposed for cold formed steel (CFS) section integrated with ferrocement slab as potential used for composite beam. Ten push-out test specimens of cold-formed steel lipped channel sections connected with ferrocement slab were tested. Three types of shear connectors were studied comprised of bolts, self-drilling-screw and bar angle. The connection behavior is analysed in terms of its load-slip relationship and the failure mode. The parametric studies were performed to investigate the effect on the shear connector’s capacity by varying the number of layers of wire mesh used in ferrocement slab and types of shear connector used. An analytical analysis using ANSYS program and theoretical analysis (Eurocode 4) were carried out to verify the experiment results. The results show that the experimental, theoretical, and numerical values proved to have good agreement with each other.Keywords: cold-formed steel, composite beam, ferrocement, finite element method, push-out test, shear connector
Procedia PDF Downloads 35614129 Efficacy of a Zeolite as a Detoxifier in Broiler Feed Contaminated with Aflatoxin B1
Authors: R. Stevens, W.L. Bryden
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The objective of this study was to determine the efficacy of zeolite in preventing the adverse effects of aflatoxin B1 (AFB1) in broilers. A total of 540 one-day-old Ross chicks were randomly divided into nine treatments, with four replicate pens per treatment and 15 chicks per pen. The treatments included 3 Levels of AFB1 (0,1and 2 mg/kg diet) and 3 levels of zeolite (0, 1.5 and 3 %) in a 3 ×3 factorial arrangement. The experimental treatments commenced on d 7 post-hatch. A starter diet was provided from d 1 to 14, a grower diet from d 15 to 28 and a finisher diet from d 29 to d 49. Diets were based on corn and soybeans and formulated to meet the bird's requirements. The evaluated parameters were as follows: Bodyweight, daily gain, feed intake (FI), feed conversion (FC), relative weights of organs (carcass, liver, heart and abdominal fat) and clinical biochemistry parameters: alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Bodyweight, daily gain and FC were significantly (P<0.05) impaired by aflatoxin. Relative weights of the liver and heart were also affected. The addition of zeolite (1.5 and 3 %) to the contaminated diets ameliorated the effects of aflatoxin, especially at the higher level of inclusion. These data demonstrate that this specific sorbent (zeolite) can protect against the toxicity of AFB1in young broiler chicks.Keywords: aflatoxin, broiler, toxicity, zeolite
Procedia PDF Downloads 14914128 Quantifying Spatiotemporal Patterns of Past and Future Urbanization Trends in El Paso, Texas and Their Impact on Electricity Consumption
Authors: Joanne Moyer
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El Paso, Texas is a southwest border city that has experienced continuous growth within the last 15-years. Understanding the urban growth trends and patterns using data from the National Land Cover Database (NLCD) and landscape metrics, provides a quantitative description of growth. Past urban growth provided a basis to predict 2031 future land-use for El Paso using the CA-Markov model. As a consequence of growth, an increase in demand of resources follows. Using panel data analysis, an understanding of the relation between landscape metrics and electricity consumption is further analyzed. The studies’ findings indicate that past growth focused within three districts within the City of El Paso. The landscape metrics suggest as the city has grown, fragmentation has decreased. Alternatively, the landscape metrics for the projected 2031 land-use indicates possible fragmentation within one of these districts. Panel data suggests electricity consumption and mean patch area landscape metric are positively correlated. The study provides local decision makers to make informed decisions for policies and urban planning to ensure a future sustainable community.Keywords: landscape metrics, CA-Markov, El Paso, Texas, panel data
Procedia PDF Downloads 13714127 Generalized Correlation for the Condensation and Evaporation Heat Transfer Coefficients of Propane (R290), Butane (R600), R134a, and R407c in Porous Horizontal Tubes: Experimental Investigation
Authors: M. Tarawneh
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This work is an experimental study on the heat transfer characteristics and pressure drop of different refrigerants during the condensation and evaporation processes in porous media. Four different refrigerants (R134a, R407C, 600a, R290), with different porosities were used to reach a real understanding of the actual heat transfer characteristics and pressure drop when using porous material inside the condenser and evaporator. Steel balls were used as porous media with different porosities (38%, 43%, 48%). The main goal of this project is to enhance the heat transfer coefficient during the condensation and evaporation processes when using different refrigerants and different porosities. Different correlations for the heat transfer coefficient and the pressure drop of the different refrigerants were developed. Also a generalized empirical correlation was developed for the different refrigerants. The experimental and predicted heat transfer coefficients and pressure drops were compared. It was found that, the Absolute standard deviation for the heat transfer coefficient and the pressure drop not exceeded values of 15% and 20%, respectively.Keywords: condensation, evaporation, porous media, horizontal tubes, heat transfer coefficient, propane, butane
Procedia PDF Downloads 53314126 Effective Design Factors for Bicycle-Friendly Streets
Authors: Zohreh Asadi-Shekari, Mehdi Moeinaddini, Muhammad Zaly Shah, Amran Hamzah
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Bicycle level of service (BLOS) is a measure for evaluating street conditions for cyclists. Currently, various methods are proposed for BLOS. These analytical methods however have some drawbacks: they usually assume cyclists as users that can share street facilities with motorized vehicles, it is not easy to link them to design process and they are not easy to follow. In addition, they only support a narrow range of cycling facilities and may not be applicable for all situations. Along this, the current paper introduces various effective design factors for bicycle-friendly streets. This study considers cyclists as users of streets who have special needs and facilities. Therefore, the key factors that influence BLOS based on different cycling facilities that are proposed by developed guidelines and literature are identified. The combination of these factors presents a complete set of effective design factors for bicycle-friendly streets. In addition, the weight of each factor in existing BLOS models is estimated and these effective factors are ranked based on these weights. These factors and their weights can be used in further studies to propose special bicycle-friendly street design model.Keywords: bicycle level of service, bicycle-friendly streets, cycling facilities, rating system, urban streets
Procedia PDF Downloads 48214125 Preparation and Characterization of Nanostructured FeN Electrocatalyst for Air Cathode Microbial Fuel Cell (MFC)
Authors: Md. Maksudur Rahman Khan, Chee Wai Woon, Huei Ruey Ong, Vignes Rasiah, Chin Kui Cheng, Kar Min Chan, E. Baranitharan
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The present work represents a preparation of non-precious iron-based electrocatalyst (FeN) for ORR in air-cathode microbial fuel cell by pyrolysis treatment. Iron oxalate which recovered from the industrial wastewater and Phenanthroline (Phen) were used as the iron and nitrogen precursors, respectively in preparing FeN catalyst. The performance of as prepared catalyst (FeN) was investigated in a single chambered air cathode MFC in which anaerobic sludge was used as inoculum and palm oil mill effluent as substrate. The maximum open circuit potential (OCV) and the highest power density recorded were 0.543 V and 4.9 mW/m2, respectively. Physical characterization of FeN was elucidated by using Brunauner Emmett Teller (BET), X-Ray Diffraction (XRD) analysis and Field Emission Scanning Electron Microscopy (FESEM) while the electrochemical properties were characterized by cyclic voltammetry (CV) analysis. The presence of biofilm on anode surface was examined using FESEM and confirmed using Infrared Spectroscopy and Thermogravimetric Analysis. The findings of this study demonstrated that FeN is electrochemically active and further modification is needed to increase the ORR catalytic activity.Keywords: iron based catalyst, microbial fuel cells, oxygen reduction reaction, palm oil mill effluent
Procedia PDF Downloads 32614124 Nonlinear Homogenized Continuum Approach for Determining Peak Horizontal Floor Acceleration of Old Masonry Buildings
Authors: Andreas Rudisch, Ralf Lampert, Andreas Kolbitsch
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It is a well-known fact among the engineering community that earthquakes with comparatively low magnitudes can cause serious damage to nonstructural components (NSCs) of buildings, even when the supporting structure performs relatively well. Past research works focused mainly on NSCs of nuclear power plants and industrial plants. Particular attention should also be given to architectural façade elements of old masonry buildings (e.g. ornamental figures, balustrades, vases), which are very vulnerable under seismic excitation. Large numbers of these historical nonstructural components (HiNSCs) can be found in highly frequented historical city centers and in the event of failure, they pose a significant danger to persons. In order to estimate the vulnerability of acceleration sensitive HiNSCs, the peak horizontal floor acceleration (PHFA) is used. The PHFA depends on the dynamic characteristics of the building, the ground excitation, and induced nonlinearities. Consequently, the PHFA can not be generalized as a simple function of height. In the present research work, an extensive case study was conducted to investigate the influence of induced nonlinearity on the PHFA for old masonry buildings. Probabilistic nonlinear FE time-history analyses considering three different hazard levels were performed. A set of eighteen synthetically generated ground motions was used as input to the structure models. An elastoplastic macro-model (multiPlas) for nonlinear homogenized continuum FE-calculation was calibrated to multiple scales and applied, taking specific failure mechanisms of masonry into account. The macro-model was calibrated according to the results of specific laboratory and cyclic in situ shear tests. The nonlinear macro-model is based on the concept of multi-surface rate-independent plasticity. Material damage or crack formation are detected by reducing the initial strength after failure due to shear or tensile stress. As a result, shear forces can only be transmitted to a limited extent by friction when the cracking begins. The tensile strength is reduced to zero. The first goal of the calibration was the consistency of the load-displacement curves between experiment and simulation. The calibrated macro-model matches well with regard to the initial stiffness and the maximum horizontal load. Another goal was the correct reproduction of the observed crack image and the plastic strain activities. Again the macro-model proved to work well in this case and shows very good correlation. The results of the case study show that there is significant scatter in the absolute distribution of the PHFA between the applied ground excitations. An absolute distribution along the normalized building height was determined in the framework of probability theory. It can be observed that the extent of nonlinear behavior varies for the three hazard levels. Due to the detailed scope of the present research work, a robust comparison with code-recommendations and simplified PHFA distributions are possible. The chosen methodology offers a chance to determine the distribution of PHFA along the building height of old masonry structures. This permits a proper hazard assessment of HiNSCs under seismic loads.Keywords: nonlinear macro-model, nonstructural components, time-history analysis, unreinforced masonry
Procedia PDF Downloads 16114123 Analysis of Heat Transfer in a Closed Cavity Ventilated Inside
Authors: Benseghir Omar, Bahmed Mohamed
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In this work, we presented a numerical study of the phenomenon of heat transfer through the laminar, incompressible and steady mixed convection in a closed square cavity with the left vertical wall of the cavity is subjected to a warm temperature, while the right wall is considered to be cold. The horizontal walls are assumed adiabatic. The governing equations were discretized by finite volume method on a staggered mesh and the SIMPLER algorithm was used for the treatment of velocity-pressure coupling. The numerical simulations were performed for a wide range of Reynolds numbers 1, 10, 100, and 1000 numbers are equal to 0.01,0.1 Richardson, 0.5,1 and 10.The analysis of the results shows a flow bicellular (two cells), one is created by the speed of the fan placed in the inner cavity, one on the left is due to the difference between the temperatures right wall and the left wall. Knowledge of the intensity of each of these cells allowed us to get an original result. And the values obtained from each of Nuselt convection which allow to know the rate of heat transfer in the cavity.Finally we find that there is a significant influence on the position of the fan on the heat transfer (Nusselt evolution) for values of Reynolds studied and for low values of Richardson handed this influence is negligible for high values of the latter.Keywords: thermal transfer, mixed convection, square cavity, finite volume method
Procedia PDF Downloads 42814122 Response of Pavement under Temperature and Vehicle Coupled Loading
Authors: Yang Zhong, Mei-Jie Xu
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To study the dynamic mechanics response of asphalt pavement under the temperature load and vehicle loading, asphalt pavement was regarded as multilayered elastic half-space system, and theory analysis was conducted by regarding dynamic modulus of asphalt mixture as the parameter. Firstly, based on the dynamic modulus test of asphalt mixture, function relationship between the dynamic modulus of representative asphalt mixture and temperature was obtained. In addition, the analytical solution for thermal stress in the single layer was derived by using Laplace integral transformation and Hankel integral transformation respectively by using thermal equations of equilibrium. The analytical solution of calculation model of thermal stress in asphalt pavement was derived by transfer matrix of thermal stress in multilayer elastic system. Finally, the variation of thermal stress in pavement structure was analyzed. The result shows that there is an obvious difference between the thermal stress based on dynamic modulus and the solution based on static modulus. Therefore, the dynamic change of parameter in asphalt mixture should be taken into consideration when the theoretical analysis is taken out.Keywords: asphalt pavement, dynamic modulus, integral transformation, transfer matrix, thermal stress
Procedia PDF Downloads 49414121 Effect of Colloid Versus Crystalloid Administration in Cardiopulmonary Bypass Prime Solution on Tissue and Organ Perfusionm
Authors: Mohammad Java Esmaeily
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Background: We evaluate the effects of tissue and organ perfusion during and after coronary artery bypass graft surgery with either colloid (Voluven) or crystalloid (Lactated ringers) as a prime solution. Materials and Methods: In this prospective randomized-controlled trial study, 70 patients undergoing on-pump coronary artery bypass graft surgery were randomly assigned to receive either colloid (Voluven) or crystalloid (Lactated ringer's) as a prime solution for initiation of cardiopulmonary bypass machine procedure. Tissue and organ perfusion markers, including lactate, troponin I, liver and renal function tests and electrolytes, were measured sequentially before induction (T1) to the second days after surgery (T5). Results: With the exception of chloride and potassium levels, no significant differences were detected in other measurements, and laboratory results were identical entirely in the two groups. Conclusion: Voluven® (hydroxyethyl starch, HES 130/0.4) has a not significant difference in comparison with crystalloid (Lactated ringer's) as priming solution on the basis of organ and tissue perfusion tests assessment.Keywords: prime, colloid, crystalloid, lactate, troponin, hydroxyethyl starch
Procedia PDF Downloads 7914120 Two Weeks of Multi-Modal Inpatient Treatment: Patients Suffering from Chronic Musculoskeletal Pain for over 12 Months
Authors: D. Schafer, H. Booke, R. Nordmeier
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Patients suffering from chronic musculoskeletal pain ( > 12 months) are a challenging clientele for pain specialists. A multimodal approach, characterized by a two weeks inpatient treatment, often is the ultimate therapeutic attempt. The lasting effects of such a multimodal approach were analyzed, especially since two weeks of inpatient therapy, although very intense, often seem too short to make a difference in patients suffering from chronic pain for years. The study includes 32 consecutive patients suffering from chronic pain over years who underwent a two weeks multimodal inpatient treatment of pain. Twelve months after discharge, each patient was interviewed to objectify any lasting effects. Pain was measured on admission and 12 months after discharge using the numeric rating scale (NRS). For statistics, a paired students' t-test was used. Significance was defined as p < 0.05. The average intensity of pain on admission was 8,6 on the NRS. Twelve months after discharge, the intensity of pain was still reduced by an average of 48% (average NRS 4,4), p < 0.05. Despite this significant improvement in pain severity, two thirds (66%) of the patients still judge their treatment as not sufficient. In conclusion, inpatient treatment of chronic pain has a long-lasting effect on the intensity of pain in patients suffering from chronic musculoskeletal pain for more than 12 months.Keywords: chronic pain, inpatient treatment, multimodal pain treatment, musculoskeletal pain
Procedia PDF Downloads 15714119 Comparing Implications of Manual and ROSA-assisted Total Knee Replacements on Patients and Physicians: A Scoping Review
Authors: Bassem M. Darwish, Robert H. Ablove
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Introduction: Total knee arthroscopy (TKA) is a commonly performed procedure in patients with end-stage osteoarthritis and inaccuracy of component alignment in TKA has been shown to have many adverse post-operative outcomes such as accelerated implant wear, reduced functional outcomes, and shorter overall implant survival. Robotic surgical systems have been introduced to try and improve joint alignment and functional outcomes in knee arthroscopy, one recent iteration is the ROSA knee system, released to the market in 2019. The objective of this scoping review is to map the available evidence, identify the current types of evidence, and identify knowledge gaps to guide future studies on patient outcomes following ROSA-assisted total knee arthroplasties. Methods: An electronic search was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. Search terms included ROSA, knee arthroscopy, osteoarthritis, robotic, and malalignment. Types of study participants included patients with osteoarthritis, ages 18 and older, male or female, who received manual TKA (mTKA) or ROSA-assisted TKA (rTKA), and human patients or cadavers. Published, peer-reviewed controlled trials, observational studies, and case series were included. Case reports were not included in article review. Resulting articles were first screened based on title and abstract. Articles meeting inclusion criteria based on title and abstract review then underwent full-text review by the same reviewer. Results: This scoping review identified 11 total studies, 3 prospective observational studies, and 8 retrospective observational studies - a total of 970 rTKA patients and 1745 mTKA patients. There were no case series or randomized controlled trials comparing rTKA and mTKA. Patient-centered outcomes showed promise for rTKA, where it frequently showed significantly favorable functional outcomes, measured via KOOS-JR, VAS, KSS, OKS, FJS, and PROMIS scores, at various times postoperatively. However, there was much discrepancy about which score yielded significance at which postoperative follow-up. Complication rates, reoperation rates, and LOS were very similar between mTKA and rTKA groups. Studies also showed rTKA had more accurate joint alignment within the 0 ± 3o corridor and had significantly higher rates of achieving postoperative joint angles similar to the preoperative plan. Finally, there was major agreement that rTKA cases take significantly longer time at the start, however, there is a rapid learning curve. Once past the learning curve, rTKA cases are performed in a similar time to mTKA and reduced physician stress and strain. Conclusion: The ROSA knee system represents a promising option for the management of osteoarthritis via total knee arthroscopy. The studies reviewed in this paper favor the patient-centered function outcomes, joint alignments, and physician health implications of the ROSA knee system to conventional total knee arthroscopy. Further study is warranted, however, to better understand recovery periods, longer-term functional outcomes, operative fatigue, and reduction in radiation exposure.Keywords: arthroplasty, knee, robotics, malalignment
Procedia PDF Downloads 1114118 A Study on the Comparatison of Mechanical and Thermal Properties According to Laminated Orientation of CFRP through Bending Test
Authors: Hee Jae Shin, Lee Ku Kwac, In Pyo Cha, Min Sang Lee, Hyun Kyung Yoon, Hong Gun Kim
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In rapid industrial development has increased the demand for high-strength and lightweight materials. Thus, various CFRP (Carbon Fiber Reinforced Plastics) with composite materials are being used. The design variables of CFRP are its lamination direction, order, and thickness. Thus, the hardness and strength of CFRP depend much on their design variables. In this paper, the lamination direction of CFRP was used to produce a symmetrical ply [0°/0°, -15°/+15°, -30°/+30°, -45°/+45°, -60°/+60°, -75°/+75°, and 90°/90°] and an asymmetrical ply [0°/15°, 0°/30°, 0°/45°, 0°/60° 0°/75°, and 0°/90°]. The bending flexure stress of the CFRP specimen was evaluated through a bending test. Its thermal property was measured using an infrared camera. The symmetrical specimen and the asymmetrical specimen were analyzed. The results showed that the asymmetrical specimen increased the bending loads according to the increase in the orientation angle; and from 0°, the symmetrical specimen showed a tendency opposite the asymmetrical tendency because the tensile force of fiber differs at the vertical direction of its load. Also, the infrared camera showed that the thermal property had a trend similar to that of the mechanical properties.Keywords: Carbon Fiber Reinforced Plastic (CFRP), bending test, infrared camera, composite
Procedia PDF Downloads 391