Search results for: good

Authors: B. Sathyanarayana

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As per the report of World Health Organization, more than 80% of world population uses medicines made from herbal and natural materials. They have stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. Quality assurance and control measures, such as national quality specification and standards for herbal materials, good manufacturing practices (GMP) for herbal medicines, labelling, and licensing schemes for manufacturing, imports and marketing, should be in place in every country where herbal medicines are regulated. These measures are vital for ensuring the safety and efficacy of herbal medicines. In the case of herbal products challenge begins at the stage of designing itself except the classical products. Selection of herbal ingredients, officinal parts to be used, proportions are vital. Once the formulation is designed one should take utmost care to produce the standardized product of assured quality and safety. Quality control measures should cover the validation of quality and identity of raw materials, in process control (as per SOP and GMP norms) and at the level of final product. Quality testing, safety and efficacy studies of the final product are required to ensure the safe and effective use of the herbal products in human beings. Medicinal plants being the materials of natural resource are subjected to great variation making it really difficult to fix quality standards especially in the case of polyherbal preparations. Manufacturing also needs modification according to the type of ingredients present. Hence, it becomes essential to develop Standard operative Procedure for a specific herbal product. Present paper throws a light on the challenges that are encountered during the design and development of herbal products.

Keywords: herbal product, challenges, quality, safety, efficacy

Procedia PDF Downloads 503

Authors: Youssef R. Hassan, Mohamed S. Hasanin, Reda M. Abdelhameed

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Recently, innovations in packaging security features become more important to see the originality of packaging in industrial application. Luminescent 3d printing materials have been a promising property which can provides a unique opportunity for the design and application of 3D printing. Lack emission of terbium ions, as a source of green emission, in salt form prevent its uses in industrial applications, so searching about stable and highly emitter material become essential. Nowadays, metal organic frameworks (MOFs) play an important role in designing light emitter material. In this work, fluorescent high density polyethylene (FHDPE) composite filament with Tb-benzene 1,3,5-tricarboxylate (Tb-BTC) MOFs for 3D printing have been successfully developed.HDPE pellets were mixed with Tb-BTC and melting extrustion with single screw extruders. It was found that Tb-BTCuniformly dispersed in the HDPE matrix and significantly increased the crystallinity of PE, which not only maintained the good thermal property but also improved the mechanical properties of Tb-BTC@HDPE composites. Notably, the composite filaments emitted ultra-bright green light under UV lamp, and the fluorescence intensity increased as the content of Tb-BTC increased. Finally, several brightly luminescent exquisite articles could be manufactured by fused deposition modeling (FDM) 3D printer with these new fluorescent filaments. In this context, the development of novel fluorescent Tb-BTC@HDPE composites was combined with 3D printing technology to amplified the packaging Security Features.

Keywords: 3D printing, fluorescent, packaging, security

Procedia PDF Downloads 101

Authors: Lindiwe Ngcobo

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The aim of the study is to describe and understand the benefits and costs of having biogas digesters at both household and society level. On a household level, the purpose is to understand how rural households benefit from the biogas digesters, for example, by converting animal and human waste through biogas digesters, and at what costs the benefits are realized. At a societal level, the purpose is to understand the costs and benefits of biogas digesters relative to the situation of rural communities who do not have flush toilets and have no appropriate waste disposal services while they incur electricity costs. Multiple regression analysis was used to determine the effect of biogas digesters on electricity availability and waste management. The results showed that beneficiaries spent less on electricity using household waste, and also waste disposal costs were eliminated from household expenses. A move to biogas energy production can be beneficial to rural households. It is economically and environmentally friendly. Small-scale farmers need to be introduced to agricultural innovations that can assist them in producing nutritious crops at a low cost. This can be a good opportunity to start an agribusiness that focuses on organic crops. Extensions and training institutions have to play a part in supporting households to develop entrepreneurial skills. Cost-benefit analysis showed that the benefits of biogas exceed the costs of the biogas projects. This implies that this technology should be promoted in rural households. Government financial incentives must be put in place to motivate a generation of organic Agri-prenuers.

Keywords: Agri-prenuers, biogas digester, biogas energy, disposal costs

Procedia PDF Downloads 136

Authors: Vitheejongjaroen P., Jaisin Y., Pachekrepapol U., Taweechotipatr M.

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Lactic acid bacteria (LAB) are the most common type of microorganisms that had been used as probiotics also known for many beneficial health effects. The antioxidant activity of LAB is associated with numerous health-protective effects. This research aimed to investigate the antioxidant activity of lactic acid bacteria isolated from Thai sour pork sausage for their application in fermented milk products. Antioxidant activity determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay showed that the isolate FN33-7, as 1 of 8 isolated exhibited scavenging activity in intact cell 5-7%, and supernatant 13-16%, intracellular cell free extract 42-48% respectively. This isolate was identified using 16S ribosomal DNA sequence analysis as Lactobacillus plantarum. The effect of milk fermented with L. plantarum FN33-7 on microbial count, pH and syneresis was assessed during refrigerated storage period of 28 days. The strain showed increased viability, pH level decreased, while syneresis increased. These results are similar to dairy products fermented with commercial starter cultures. Additionally, microstructure analysis of fermented milk by fluorescent microscopy showed that curd structure appeared to be dense and less porous in this fermented milk than commercial yogurt. The results of this study indicated that L. plantarum FN33-7 was a good probiotic candidate to be used in cultured milk products to reduce the risk of diseases caused by oxidative stress.

Keywords: Lactobacillus plantarum, probiotics, free radical, antioxidant, oxidative stress, fermented milk products

Procedia PDF Downloads 131

Authors: Issam Lakdhar, Akram Alhussein, Juan Creus

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With the huge increase in world energy consumption, researchers are working to find other alternative sources of energy instead of fossil fuel one causing many environmental problems as the production of greenhouse effect gases. Hydrogen is considered a green energy source, which its combustion does not cause environmental pollution. The transport and the storage of the gas molecules or the other products containing this smallest chemical element in metallic structures (pipelines, tanks) are crucial issues. The dissolve and the permeation of hydrogen into the metal lattice lead to the formation of hydride phases and the embrittlement of structures. To protect the metallic structures, a surface treatment could be a good solution. Among the different techniques, magnetron sputtering is used to elaborate micrometric coatings capable of slowing down or stop hydrogen permeation. In the plasma environment, the deposition parameters of new thin-film metallic glasses Al-Ti-W were optimized and controlled in order to obtain, hydrogen barrier. Many characterizations were carried out (SEM, XRD and Nano-indentation…) to control the composition and understand the influence of film microstructure and chemical composition on the hydrogen permeation through the coatings. The coating performance was evaluated under two hydrogen production methods: chemical and electrochemical (cathodic protection) techniques. The hydrogen quantity absorbed was experimentally determined using the Thermal-Desorption Spectroscopy method (TDS)). An ideal ATW thin film was developed and showed excellent behavior against the diffusion of hydrogen.

Keywords: thin films, hydrogen, PVD, plasma technology, electrochemical properties

Procedia PDF Downloads 185

Authors: Raoul Ouambo Tobou, Alexis Kuitche, Marcel Edoun

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The FWM (Finite Window Method) is a new numerical meshfree technique for solving problems defined either in terms of PDEs (Partial Differential Equation) or by a set of conservation/equilibrium laws. The principle behind the FWM is that in such problem each element of the concerned domain is interacting with its neighbors and will always try to adapt to keep in equilibrium with respect to those neighbors. This leads to a very simple and robust problem solving scheme, well suited for transfer problems. In this work, we have applied the FWM to an unsteady scalar convection-diffusion equation. Despite its simplicity, it is well known that convection-diffusion problems can be challenging to be solved numerically, especially when convection is highly dominant. This has led researchers to set the scalar convection-diffusion equation as a benchmark one used to analyze and derive the required conditions or artifacts needed to numerically solve problems where convection and diffusion occur simultaneously. We have shown here that the standard FWM can be used to solve convection-diffusion equations in a robust manner as no adjustments (Upwinding or Artificial Diffusion addition) were required to obtain good results even for high Peclet numbers and coarse space and time steps. A comparison was performed between the FWM scheme and both a first order implicit Finite Volume Scheme (Upwind scheme) and a third order implicit Finite Volume Scheme (QUICK Scheme). The results of the comparison was that for equal space and time grid spacing, the FWM yields a much better precision than the used Finite Volume schemes, all having similar computational cost and conditioning number.

Keywords: Finite Window Method, Convection-Diffusion, Numerical Technique, Convergence

Procedia PDF Downloads 332

Authors: Chi-Yuan Huang, Mei-Chuan Kuo, Ching-Yi Hsiao

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In this study, acids with various chain lengths (C₆, C₈, C₁₀ and C₁₂) modified by methane sulfonic acid (MSA) and temperature were used to modify tapioca starch (TPS), then the glycerol (GA) were added into modified starch, to prepare new blends. The mechanical properties, thermal properties and physical properties of blends were studied. This investigation was divided into two parts.  First, the biodegradable materials were used such as starch and glycerol with hexanedioic acid (HA), suberic acid (SBA), sebacic acid (SA), decanedicarboxylic acid (DA) manufacturing with different temperatures (90, 110 and 130 °C). And then, the solution was added into modified starch to prepare the blends by using single-screw extruder. The FT-IR patterns indicated that the characteristic peak of C=O in ester was observed at 1730 cm^-1. It is proved that different chain length acids (C₆, C₈, C₁₀ and C₁₂) reacted with glycerol by esterification and these are used to plasticize blends during extrusion. In addition, the blends would improve the hydrolysis and thermal stability. The water contact angle increased from 43.0° to 64.0°.  Second, the HA (110 °C), SBA (110 °C), SA (110 °C), and DA blends (130 °C) were used in study, because they possessed good mechanical properties, water resistances and thermal stability. On the other hand, the various contents (0, 0.005, 0.010, 0.020 g) of MSA were also used to modify the mechanical properties of blends. We observed that the blends were added to MSA, and then the FT-IR patterns indicated that the C=O ester appeared at 1730 cm^-1. For this reason, the hydrophobic blends were produced. The water contact angle of the MSA blends increased from 55.0° to 71.0°. Although break elongation of the MSA blends reduced from the original 220% to 128%, the stress increased from 2.5 MPa to 5.1 MPa. Therefore, the optimal composition of blends was the DA blend (130 °C) with adding of MSA (0.005 g).

Keywords: chain length acids, methane sulfonic acid, Tapioca starch (TPS), tensile stress

Procedia PDF Downloads 249

Authors: Olivier Delage, Hassan Bencherif, Alain Bourdier

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Signal decomposition approaches represent an important step in time series analysis, providing useful knowledge and insight into the data and underlying dynamics characteristics while also facilitating tasks such as noise removal and feature extraction. As most of observational time series are nonlinear and nonstationary, resulting of several physical processes interaction at different time scales, experimental time series have fluctuations at all time scales and requires the development of specific signal decomposition techniques. Most commonly used techniques are data driven, enabling to obtain well-behaved signal components without making any prior-assumptions on input data. Among the most popular time series decomposition techniques, most cited in the literature, are the empirical mode decomposition and its variants, the empirical wavelet transform and singular spectrum analysis. With increasing popularity and utility of these methods in wide ranging applications, it is imperative to gain a good understanding and insight into the operation of these algorithms. In this work, we describe all of the techniques mentioned above as well as their ability to denoise signals, to capture trends, to identify components corresponding to the physical processes involved in the evolution of the observed system and deduce the dimensionality of the underlying dynamics. Results obtained with all of these methods on experimental total ozone columns and rainfall time series will be discussed and compared

Keywords: denoising, empirical mode decomposition, singular spectrum analysis, time series, underlying dynamics, wavelet analysis

Procedia PDF Downloads 118

Authors: Habtamu Tkubet Ebuy

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Purpose Conventional dynamic energy simulation tools go beyond the static dimension of simplified methods by providing better and more accurate prediction of building performance. However, their ability to forecast actual performance is undermined by a low representation of human interactions. The purpose of this study is to examine the potential benefits of incorporating information on occupant diversity into occupant behavior models used to simulate building performance. The co-simulation of the stochastic behavior of the occupants substantially increases the accuracy of the simulation. Design/methodology/approach In this article, probabilistic models of the "opening and closing" behavior of the window of inhabitants have been developed in a separate multi-agent platform, SimOcc, and implemented in the building simulation, TRNSYS, in such a way that the behavior of the window with the interconnectivity can be reflected in the simulation analysis of the building. Findings The results of the study prove that the application of complex behaviors is important to research in predicting actual building performance. The results aid in the identification of the gap between reality and existing simulation methods. We hope this study and its results will serve as a guide for researchers interested in investigating occupant behavior in the future. Research limitations/implications Further case studies involving multi-user behavior for complex commercial buildings need to more understand the impact of the occupant behavior on building performance. Originality/value This study is considered as a good opportunity to achieve the national strategy by showing a suitable tool to help stakeholders in the design phase of new or retrofitted buildings to improve the performance of office buildings.

Keywords: occupant behavior, co-simulation, energy consumption, thermal comfort

Procedia PDF Downloads 104

Authors: Ying-Ming Su

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Fujian earthen building which was known as a classic for ecological buildings was listed on the world heritage in 2008 (UNESCO) in China. Its design strategy can be applied to modern architecture planning and design. This study chose two different cases (Round Atrium: Er-Yi Building, Double Round Atrium: Zhen-Chen Building) of earthen building in Fu-Jian to compare the ventilation effects of different atrium forms. We adopt field measurements and computational fluid dynamics (CFD) simulation of temperature, humidity, and wind environment to identify the relationship between external environment and atrium about comfort and to confirm the relationship about atrium H/W (height/width). Results indicate that, through the atrium convection effect, it makes the natural wind guides to each space surrounded and keeps indoor comfort. It illustrates that the smaller the ratio of the H/W which is the relationship between the height and the width of an atrium is, the greater the wind speed generated within the street valley. Moreover, the wind speed is very close to the reference wind speed. This field measurement verifies that the value of H/W has great influence of solar radiation heat and sunshine shadows. The ventilation efficiency is: Er-Yi Building (H/W =0.2778) > Zhen-Chen Building (H/W=0.3670). Comparing the cases with the same shape but with different H/W, through the different size patios, airflow revolves in the atriums and can be brought into each interior space. The atrium settings meet the need of building ventilation, and can adjust the humidity and temperature within the buildings. It also creates good ventilation effect.

Keywords: traditional folk houses, atrium, tulou, ventilation, building microclimate

Procedia PDF Downloads 475

Authors: Mahmoodreza Tahamtan

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Background: Malignant surface epithelial ovarian tumors (SEOT) account for approximately 90% of primary ovarian cancer. Wilms tumor gene (WT1) product was defined as a tumor suppressor gene, but today it is considered capable of performing oncogenic functions. There seems to be differences in WT1 expression patterns among SEOT subtypes. We evaluate the immunohistochemical expression of WT1 protein among different histologic subtypes of SEOT. Materials and Methods: Immunohistochemistry for WT1 was done on 35 serous cystadenocarcinomas, 9 borderline serous tumors, 3 mucinous cystadenocarcinomas, 10 borderline mucinous tumors, 7 endometrioid ovarian carcinomas, 3 clear cell carcinomas, 1 malignant Brenner tumor, 2 metastatic adenocarcinomas, and 6 endometrial adenocarcinomas. A tumor was considered negative if < 1% of tumor cells were stained.Positive reactions were graded as follows:1+,1%-24%; 2+,25%-49%; 3+,50%-74%; 4+,75%-100%. Results: Of the 35 cases of ovarian serous cystadenocarcinoma, 30(85.7%) were diffusely positive (3+,4+),4 showed reactivity of < 50% of the tumor cells (1+,2+), and one were negative. All 9 borderline serous tumors showed immunoreactivity with WT1. All the mucinous tumors(n:13), endometrioid carcinomas (n: 7), clear cell carcinomas (n: 3), metastatic adenocarcinomas (n: 2) and primary endometrial carcinomas (n:6) were negative. The single malignant Brenner tumor showed a positive reaction for WT1(4+) Conclusion: WT1 is a good marker to distinguish primary ovarian serous carcinomas from other surface epithelial tumors (especially endometrioid subtype) and metastatic carcinomas (especially endometrial serous carcinoma), other than malignant mesothelioma. We cannot rely to the degree of expression inorder to separate high grade borderline serous tumors from low grade ones.

Keywords: WT1, ovary, epithelial tumors, malignant

Procedia PDF Downloads 103

Authors: N. Prabavathy, R. Balasundaraprabhu, S. Shalini, Dhayalan Velauthapillai, S. Prasanna, N. Muthukumarasamy

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Dye sensitized solar cell (DSSC) has become a significant research area due to their fundamental and scientific importance in the area of energy conversion. Synthetic dyes as sensitizer in DSSC are efficient and durable but they are costlier, toxic and have the tendency to degrade. Natural sensitizers contain plant pigments such as anthocyanin, carotenoid, flavonoid, and chlorophyll which promote light absorption as well as injection of charges to the conduction band of TiO2 through the sensitizer. But, the efficiency of natural dyes is not up to the mark mainly due to instability of the pigment such as anthocyanin. The stability issues in vitro are mainly due to the effect of solvents on extraction of anthocyanins and their respective pH. Taking this factor into consideration, in the present work, the anthocyanins were extracted from the flower Caesalpinia pulcherrima (C. pulcherrimma) with various solvents and their respective stability and pH values are discussed. The usage of citric acid as solvent to extract anthocyanin has shown good stability than other solvents. It also helps in enhancing the sensitization properties of anthocyanins with Titanium dioxide (TiO2) nanorods. The IPCE spectra show higher photovoltaic performance for dye sensitized TiO2nanorods using citric acid as solvent. The natural DSSC using citric acid as solvent shows a higher efficiency compared to other solvents. Hence citric acid performs to be a safe solvent for natural DSSC in boosting the photovoltaic performance and maintaining the stability of anthocyanins.

Keywords: Caesalpinia pulcherrima, citric acid, dye sensitized solar cells, TiO₂ nanorods

Procedia PDF Downloads 290

Authors: Ameema Mahroof, Muhammad Saeed

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The purpose of this study was to analyze the papers of computer science conducted by Board of Intermediate and Secondary Education with reference to Bloom’s taxonomy. The present study has two parts. First, the analysis is done on the papers conducted by Board of Intermediate of Secondary Education on the basis of basic rules of item construction especially Bloom’s (1956). And the item analysis is done to improve the psychometric properties of a test. The sample included the question papers of computer science of higher secondary classes (XI-XII) for the years 2011 and 2012. For item analysis, the data was collected from 60 students through convenient sampling. Findings of the study revealed that in the papers by Board of intermediate and secondary education the maximum focus was on knowledge and understanding level and very less focus was on the application, analysis, and synthesis. Furthermore, the item analysis on the question paper reveals that item difficulty of most of the questions did not show a balanced paper, the items were either very difficult while most of the items were too easy (measuring knowledge and understanding abilities). Likewise, most of the items were not truly discriminating the high and low achievers; four items were even negatively discriminating. The researchers also analyzed the items of the paper through software Conquest. These results show that the papers conducted by Board of Intermediate and Secondary Education were not well constructed. It was recommended that paper setters should be trained in developing the question papers that can measure various cognitive abilities of students so that a good paper in computer science should assess all cognitive abilities of students.

Keywords: Bloom’s taxonomy, question paper, item analysis, cognitive domain, computer science

Procedia PDF Downloads 151

Authors: Muhammad Ameer Nawaz Akram

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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 134

Authors: Nicolò Vaiana, Giorgio Serino

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In this paper, a one-dimensional (1d) Parallel Elasto- Plastic Model (PEPM), able to simulate the uniaxial dynamic behavior of seismic isolators having a continuously decreasing tangent stiffness with increasing displacement, is presented. The parallel modeling concept is applied to discretize the continuously decreasing tangent stiffness function, thus allowing to simulate the dynamic behavior of seismic isolation bearings by putting linear elastic and nonlinear elastic-perfectly plastic elements in parallel. The mathematical model has been validated by comparing the experimental force-displacement hysteresis loops, obtained testing a helical wire rope isolator and a recycled rubber-fiber reinforced bearing, with those predicted numerically. Good agreement between the simulated and experimental results shows that the proposed model can be an effective numerical tool to predict the forcedisplacement relationship of seismic isolators within relatively large displacements. Compared to the widely used Bouc-Wen model, the proposed one allows to avoid the numerical solution of a first order ordinary nonlinear differential equation for each time step of a nonlinear time history analysis, thus reducing the computation effort, and requires the evaluation of only three model parameters from experimental tests, namely the initial tangent stiffness, the asymptotic tangent stiffness, and a parameter defining the transition from the initial to the asymptotic tangent stiffness.

Keywords: base isolation, earthquake engineering, parallel elasto-plastic model, seismic isolators, softening hysteresis loops

Procedia PDF Downloads 280

Authors: A. Bilek, M. Beldi, T. Cherfi, S. Djebali, S. Larbi

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Finite elements analysis and photoelasticity are used to determine the stress field developed in a double edge notched specimen loaded in tension. The specimen is cut in a birefringent plate. Experimental isochromatic fringes are obtained with circularly polarized light on the analyzer of a regular polariscope. The fringes represent the loci of points of equal maximum shear stress. In order to obtain the stress values corresponding to the fringe orders recorded in the notched specimen, particularly in the neighborhood of the notches, a calibrating disc made of the same material is loaded in compression along its diameter in order to determine the photoelastic fringe value. This fringe value is also used in the finite elements solution in order to obtain the simulated photoelastic fringes, the isochromatics as well as the isoclinics. A color scale is used by the software to represent the simulated fringes on the whole model. The stress concentration factor can be readily obtained at the notches. Good agreements are obtained between the experimental and the simulated fringe patterns and between the graphs of the shear stress particularly in the neighborhood of the notches. The purpose in this paper is to show that one can obtain rapidly and accurately, by the finite element analysis, the isochromatic and the isoclinic fringe patterns in a stressed model as the experimental procedure can be time consuming. Stress fields can therefore be analyzed in three dimensional models as long as the meshing and the limit conditions are properly set in the program.

Keywords: isochromatic fringe, isoclinic fringe, photoelasticity, stress concentration factor

Procedia PDF Downloads 229

Authors: Gayan Mapitiya

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Maintaining good occupational health and safety (OHS) performance is significant at the coalface, especially in industries such as mining, power, and construction. Coalface workers are vulnerable to high OHS risks such as working at heights, working with mobile plants and vehicles, working with underground and above ground services, chemical emissions, radiation hazards and explosions at everyday work. To improve OHS performance of workers, OHS key performance indicators (KPIs) (for example, lost time injuries (LTI), serious injury frequency rate (SIFR), total reportable injury frequency rate (TRIFR) and number of near misses) are widely used by managers in making OHS business decisions such as investing in safety equipment and training programs. However, in many organizations, workers at the coalface hardly see any relevance or value addition of OHS KPIs to their everyday work. Therefore, the aim of the study was to understand why coalface workers perceive that OHS KPIs are not practically relevant to their jobs. Accordingly, this study was conducted as a qualitative case study focusing on a large electricity and gas firm in Australia. Semi-structured face to face interviews were conducted with selected coalface workers to gather data on their attitude towards OHS KPIs. The findings of the study revealed that workers at the coalface generally have no understanding of the purpose of KPIs, the meaning of each KPI, origin of KPIs, and how KPIs are correlated to organizational performance. Indeed, KPIs are perceived as ‘meaningless obstacles’ imposed on workers by managers without a rationale. It is recommended to engage coalface workers (a fair number of representatives) in both KPIs setting and revising processes while maintaining a continuous dialogue between workers and managers in regards OHS KPIs.

Keywords: KPIs, coalface, OHS risks, case-study

Procedia PDF Downloads 116

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

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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 308

Authors: H. Trabelsi, A. Chehma, I. Benseddik

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Animals can play an important role in the seed dispersal cycle through the active or passive uptake of seeds and the subsequent external (epizoochory) or internal transport (endozoochory) of seeds. In Algeria, small ruminants and camels are generally conducted in extensive livestock exploiting the Saharan and steppe rangelands. To get an idea on the ecological potential role of these animals in the spontaneous plants proliferation, we propose to make a study of seeds dispersal and germination possibilities by camel faeces compared to those of small ruminants. Manual faeces decortication of the two animals categories has allowed to inventory 72 seed which 71% are in good condition, while 29% of the seeds that are encountered are partially altered and could not be identified. The species that have been identified, from small ruminants dung are weeds of cultures, while those identified from camel dung are spontaneous plants of Saharan rangeland. Concerning germination in the laboratory, only 3 species seeds were germinated from camel feces, whose germination rate varies from 25% to 100%. Contrary to Sheep-Goat feces, a single species germinated with 71%. The three months seed germination in greenhouse allowed to identify 10 species belonging to 4 botanical families (5 species from small ruminants dung and 3 species from Camel dung). In general, the results show the positive effect played by two animals categories for plants seed dispersal with the camel particularity for spontaneous plants due to its capacity to cover long distances in different rangeland types.

Keywords: Algeria, camel, endozoochory, seeds, sheep-goat, rangeland

Procedia PDF Downloads 314

Authors: Malinwo Estone Ayikpa

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With the rapid increase of grid-connected PV systems over the last decades, genuine challenges have arisen for engineers and professionals of energy field in the planning and operation of existing distribution networks with the integration of new generation sources. However, the conventional distribution network, in its design was not expected to receive other generation outside the main power supply. The tools generally used to analyze the networks become inefficient and cannot take into account all the constraints related to the operation of grid-connected PV systems. Some of these constraints are voltage control difficulty, reverse power flow, and especially voltage unbalance which could be due to the poor distribution of single-phase PV systems in the network. In order to analyze the impact of the connection of small and large number of PV systems to the distribution networks, this paper presents an efficient optimization tool that minimizes voltage unbalance in three-phase distribution networks with active and reactive power injections from the allocation of single-phase and three-phase PV plants. Reactive power can be generated or absorbed using the available capacity and the adjustable power factor of the inverter. Good reduction of voltage unbalance can be achieved by reactive power control of the PV systems. The presented tool is based on the three-phase current injection method and the PV systems are modeled via an equivalent circuit. The primal-dual interior point method is used to obtain the optimal operating points for the systems.

Keywords: Photovoltaic system, Primal-dual interior point method, Three-phase optimal power flow, Voltage unbalance

Procedia PDF Downloads 332

Authors: Basavaraj Kabade, K. T. Nagaraja, Swathi Ramanathan, A. Veeraragavan, P. S. Reashma

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Deteriorating quality of the pedestrian environment and the increasing risk of pedestrian crashes are major concerns for most of the cities in India. The recent shift in the priority to motorized transport and the abating condition of existing pedestrian facilities can be considered as prime reasons for the increasing pedestrian related crashes in India. Bengaluru City – the IT capital hub of the nation is not much different from this. The increase in number of pedestrian crashes in Bengaluru reflects the same. To resolve this issue and to ensure safe, sustainable and pedestrian friendly sidewalks, Govt. of Karnataka, India has implemented newfangled pedestrian sidewalks popularized programme named Tender S.U.R.E. (Specifications for Urban Road Execution) projects. Tender SURE adopts unique urban street design guidelines where the pedestrians are given prime preference. The present study presents an assessment of the quality and performance of the pedestrian side walk and the walkability index of the newly built pedestrian friendly sidewalks. Various physical and environmental factors affecting pedestrian safety are identified and studied in detail. The pedestrian mobility is quantified through Pedestrian Level of Service (PLoS) and the pedestrian walking comfort is measured by calculating the Walkability Index (WI). It is observed that the new initiatives taken in reference to improving pedestrian safety have succeeded in Bengaluru by attaining a level of Service of ‘A’ and with a good WI score.

Keywords: pedestrian safety, pedestrian level of service (PLoS), Right of Way (RoW), Tender S.U.R.E (Specifications for Urban Road Execution), walkability index (WI), walkway facilities

Procedia PDF Downloads 201

Authors: Shivani Jha, Klaus Baier, Rafiq Azzam, Ramakar Jha

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In India, generally people migrate from rural area to the urban area for better infra-structural facilities, high standard of living, good job opportunities and advanced transport/communication availability. In fact, unplanned urban development due to migration of people causes seriou damage to the land use, water pollution and available water resources. In the present work, an attempt has been made to use satellite data of different years for urban change detection of Chennai metropolitan city along with pattern analysis to generate future scenario of urban development using buffer zoning in GIS environment. In the analysis, SRTM (30m) elevation data and IRS-1C satellite data for the years 1990, 2000, and 2014, are used. The flow accumulation, aspect, flow direction and slope maps developed using SRTM 30 m data are very useful for finding suitable urban locations for industrial setup and urban settlements. Normalized difference vegetation index (NDVI) and Principal Component Analysis (PCA) have been used in ERDAS imagine software for change detection in land use of Chennai metropolitan city. It has been observed that the urban area has increased exponentially in Chennai metropolitan city with significant decrease in agriculture and barren lands. However, the water bodies located in the study regions are protected and being used as freshwater for drinking purposes. Using buffer zone analysis in GIS environment, it has been observed that the development has taken place in south west direction significantly and will do so in future.

Keywords: urban change, satellite data, the Chennai metropolis, change detection

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

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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

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Authors: Itsaree Padphai, Jiranan Pakpeian, Suksun Niponchai

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This study is a descriptive research which aims to: 1) Compare the difference of knowledge before and after using the e-Learning program entitled “Basic Cardiopulmonary Resuscitation for Students in an Emergency Medical Technician Diploma Program”, and 2) Assess the students’ satisfaction after using the said program. This research is a kind of teaching and learning management supplemented with the e-Learning system; therefore, the purposively selected samples are 44 first-year and class-16 students of an emergency medical technician diploma program who attend the class in a second semester of academic year 2012 in Sirindhorn College of Public Health, Khon Kaen province. The research tools include 1) the questionnaire for general information of the respondents, 2) the knowledge tests before and after using the e-Learning program, and 3) an assessment of satisfaction in using the e-Learning program. The statistics used in data analysis percentage, include mean, standard deviation, and inferential statistics: paired t-test. 1. The general information of the respondents was mostly 37 females representing 84.09 percent. The average age was 19.5 years (standard deviation was 0.81), the maximum age was 21 years, and the minimum age was 19 years respectively. Students (35 subjects) admitted that they preferred the methods of teaching and learning by using the e-Learning systems. This was totally 79.95 percent. 2. A comparison on the difference of knowledge before and after using the e-Learning program showed that the mean before an application was 6.64 (standard deviation was 1.94) and after was 18.84 (standard deviation 1.03), which was higher than the knowledge of students before using the e-Learning program with the statistical significance (P value < 0.001). 3. For the satisfaction after using the e-Learning program, it was found that students’ satisfaction was at a very good level with the mean of 4.93 (standard deviation was 0.11).

Keywords: e-Learning, cardiopulmonary resuscitation, diploma program, Khon Kaen Province

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Authors: Pankaj Kumar Kalita

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Ineffectiveness of formal institutional mechanisms such as official audit to improve public service delivery has been a serious concern to scholars working on governance reforms in developing countries. Scholars argue that public service delivery in local self-governing institutions can be improved through application of informal mechanisms such as social accountability. Social accountability has been reinforced with the engagement of citizens and civic organizations in the process of service delivery to reduce the governance gap in developing countries. However, there are challenges that may impede the scope of establishing social accountability initiatives in the performance of local self-governing institutions. This study makes an attempt to investigate the factors that may impede the scope of establishing social accountability, particularly in culturally heterogeneous societies like India. While analyzing the implementation of two rural development schemes by Panchayats, the local self-governing institutions functioning in rural Assam in India, this study argues that the scope of establishing social accountability in the performance of local self-governing institutions, particularly in culturally heterogeneous societies in developing countries will be impeded by the absence of inter-caste and inter-religion networks. Data has been collected from five selected districts of Assam using in-depth interview method and survey method. The study further contributes to the debates on 'good governance' and citizen-centric approaches in developing countries.

Keywords: citizen engagement, local self-governing institutions, networks, social accountability

Procedia PDF Downloads 319

Authors: C. C. Egwuonwu, N. A. A. Okereke, K. O. Chilakpu, S. O. Ohanyere

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In this study, initial soil strength indices (qu) and stress-strain characteristics, namely failure strain (ϵf), area under the stress-strain curve up to failure (Is) and stress-strain modulus between no load and failure (Es) were investigated as potential indicators for characterizing the erosion resistance of two compacted soils, namely sandy clay loam (SCL) and clay loam (CL) in some selected sites in Enugu State, Nigeria. The unconfined compressive strength (used in obtaining strength indices) and stress-strain measurements were obtained as a function of moisture content in percentage (mc %) and dry density (γd). Test were conducted over a range of 8% to 30% moisture content and 1.0 g/cm3 to 2.0 g/cm3 dry density at applied loads of 20, 40, 80, 160 and 320 kPa. Based on the results, it was found out that initial soil strength alone was not a good indicator of erosion resistance. For instance, in the comparison of exponents of mc% and γd for jet index or erosion resistance index (Ji) and the strength measurements, qu and Es agree in signs for mc%, but are opposite in signs for γd. Therefore, there is an inconsistency in exponents making it difficult to develop a relationship between the strength parameters and Ji for this data set. In contrast, the exponents of mc% and γd for Ji and ϵf and Is are opposite in signs, there is potential for an inverse relationship. The measured stress-strain characteristics, however, appeared to have potential in providing useful information on erosion resistance. The models developed for the prediction of the extent or the susceptibility of soils to erosion and subjected to sensitivity test on some selected sites achieved over 90% efficiency in their functions.

Keywords: characterization of erodibility, selected sites in Enugu state, soil strength, stress-strain indices

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Authors: Niveen M. Hassan-Abbas

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The COVID-19 pandemic created a range of stressors, among them difficulties related to work conditions, financial changes, lack of childcare, and confinement or isolation due to social distancing. Among families and married individuals, these stressors were often expressed in additional daily hassles, with an influence on mental health. This study examined two moderated mediation models based on Bodenmann’s systemic-transactional stress model. Specifically, the models tested the hypothesis that intra-dyadic stress mediates the association between extra-dyadic stress and mental health, while two measures of family functioning, cohesion, and flexibility, moderate the relationship between extra and intra-dyadic stress. Participants were 480 heterosexual married Palestinians from Israel who completed self-report questionnaires. The results showed partial mediation patterns supporting both models, indicating that family cohesion and flexibility weakened the mediating effect of intra-dyadic stress on the relationship between extra-dyadic stress and mental health. These findings increase our understanding of the variables that affected mental health during the pandemic and suggested that when faced with extra-dyadic stress, married individuals with good family environments are less likely to experience high levels of intra-dyadic stress, which is in turn associated with preserved mental health. Limitations and implications for planning interventions for couples and families during the pandemic are discussed.

Keywords: Palestinian families in Israel, COVID-19 pandemic, family cohesion and flexibility, extra-dyadic stress, intra-dyadic stress, mental health

Procedia PDF Downloads 95

Authors: Ying-Chang Yu, Yuan-Lung Lo

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Building ventilation performance is an important indicator of indoor comfort. However, in addition to the geometry of the building or the proportion of the opening, the ventilation performance is also very much related to the actual wind pressure of the building. There are more and more contemporary building designs built with multi-layer exterior envelope. Due to ventilation and view observatory requirement, the porous outer layer of the building is commonly adopted and has a significant wind damping effect, causing the phenomenon of actual wind pressure loss. However, the relationship between the wind damping effect and the actual wind pressure is not linear. This effect can make the indoor ventilation of the building rationalized to reasonable range under the condition of high wind pressure, and also maintain a good amount of ventilation performance under the condition of low wind pressure. In this study, wind tunnel experiments were carried out to simulate the different wind pressures flow through the porous outer layer, and observe the actual wind pressure strength engage with the window layer to find the decreasing relationship between the damping effect of the porous shell and the wind pressure. Experiment specimen scale was designed to be 1:50 for testing real-world building conditions; the study found that the porous enclosure has protective shielding without affecting low-pressure ventilation. Current study observed the porous skin may damp more wind energy to ease the wind pressure under high-speed wind. Differential wind speed may drop the pressure into similar pressure level by using porous skin. The actual mechanism and value of this phenomenon will need further study in the future.

Keywords: multi-layer facade, porous media, wind damping, wind tunnel test, building ventilation

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Authors: Khalid M. Albarkoly, Kenneth S. Park

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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 390

Authors: Sanjin Kršćanski, Josip Brnić

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Virtual Crack Closure Technique (VCCT) is a method used for calculating stress intensity factor (SIF) of a cracked body that is easily implemented on top of basic finite element (FE) codes and as such can be applied on the various component geometries. It is a relatively simple method that does not require any special finite elements to be used and is usually used for calculating stress intensity factors at the crack tip for components made of brittle materials. This paper studies applicability and accuracy of VCCT applied on standard metal specimens containing trough thickness crack, subjected to an in-plane bending load. Finite element analyses were performed using regular 4-node, regular 8-node and a modified quarter-point 8-node 2D elements. Stress intensity factor was calculated from the FE model results for a given crack length, using data available from FE analysis and a custom programmed algorithm based on virtual crack closure technique. Influence of the finite element size on the accuracy of calculated SIF was also studied. The final part of this paper includes a comparison of calculated stress intensity factors with results obtained from analytical expressions found in available literature and in ASTM standard. Results calculated by this algorithm based on VCCT were found to be in good correlation with results obtained with mentioned analytical expressions.

Keywords: VCCT, stress intensity factor, finite element analysis, 2D finite elements, bending

Procedia PDF Downloads 305