Search results for: one-sided thermal damage

Authors: Stephanie Wall, Guido Wimmers

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The construction and operation of buildings greatly contribute to environmental degradation through resource and energy consumption and greenhouse gas emissions. The design of the envelope system affects the environmental impact of a building in two major ways; 1) high thermal performance and air tightness can significantly reduce the operational energy of the building and 2) the material selection for the envelope largely impacts the embodied energy of the building. Life cycle assessment (LCA) is a scientific methodology that is used to systematically analyze the environmental load of processes or products, such as buildings, over their life. The paper will discuss the results of a comparative LCA of different envelope designs and the long-term monitoring of the Wood Innovation Research Lab (WIRL); a Passive House (PH), industrial building under construction in Prince George, Canada. The WIRL has a footprint of 30m x 30m on a concrete raft slab foundation and consists of shop space as well as a portion of the building that includes a two-story office/classroom space. The lab building goes beyond what was previously thought possible in regards to energy efficiency of industrial buildings in cold climates due to their large volume to surface ratio, small floor area, and high air change rate, and will be the first PH certified industrial building in Canada. These challenges were mitigated through the envelope design which utilizes solar gains while minimizing overheating, reduces thermal bridges with thick (570mm) prefabricated truss walls filled with blown in mineral wool insulation and a concrete slab and roof insulated with EPS rigid insulation. The envelope design results in lower operational and embodied energy when compared to buildings built to local codes or with steel. The LCA conducted using Athena Impact Estimator for Buildings identifies project specific hot spots as well illustrates that for high-efficiency buildings where the operational energy is relatively low; the embodied energy of the material selection becomes a significant design decision as it greatly impacts the overall environmental footprint of the building. The results of the LCA will be reinforced by long-term monitoring of the buildings envelope performance through the installation of temperature and humidity sensors throughout the floor slab, wall and roof panels and through detailed metering of the energy consumption. The data collected from the sensors will also be used to reinforce the results of hygrothermal analysis using WUFI®, a program used to verify the durability of the wall and roof panels. The WIRL provides an opportunity to showcase the use of wood in a high performance envelope of an industrial building and to emphasize the importance of considering the embodied energy of a material in the early stages of design. The results of the LCA will be of interest to leading researchers and scientists committed to finding sustainable solutions for new construction and high-performance buildings.

Keywords: high performance envelope, life cycle assessment, long term monitoring, passive house, prefabricated panels

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Authors: Hyung T. Kwak, Jun Gao, Yao An, Alfred Kleinhammes, Yue Wu

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Surface wettability is a crucial factor in oil recovery. In oil industry, the rock wettability involves the interplay between water, oil, and solid surface. Therefore, studying the interplay between adsorptions of water and hydrocarbon molecules on solid surface would be very informative for understanding rock wettability. Here we use the in-situ Nuclear Magnetic Resonance (NMR) gas isotherm technique to study competitive adsorptions of water and isopropanol, an intermediate step from hydrocarbons. This in-situ NMR technique obtains information on thermodynamic properties such as the isotherm, molecular dynamics via spin relaxation measurements, and adsorption kinetics such as how fast the system can reach thermal equilibrium after changes of vapor pressures. Using surfaces of silica glass beads, which can be modified from hydrophilic to hydrophobic, we obtained information on the influence of surface hydrophilicity on the state of surface water via obtained thermodynamic and dynamic properties.

Keywords: Wettability, NMR, Gas Isotherm, Hydrophilicity, adsorption

Procedia PDF Downloads 179

Authors: Necati Içer

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Crop-hail insurance plays a vital role in managing risks and reducing the financial consequences of hail damage on crop production. Predicting insurance premium rates with short-term data is a major difficulty in numerous nations because of the unique characteristics of hailstorms. This study aims to suggest a feasible approach for establishing equitable premium rates in crop-hail insurance for nations with short-term insurance data. The primary goal of the rate-making process is to determine premium rates for high and zero loss costs of villages and enhance their credibility. To do this, a technique was created using the author's practical knowledge of crop-hail insurance. With this approach, the rate-making method was developed using a range of temporal and spatial factor combinations with both hypothetical and real data, including extreme cases. This article aims to show how to incorporate the temporal and spatial elements into determining fair premium rates using short-term insurance data. The article ends with a suggestion on the ultimate premium rates for insurance contracts.

Keywords: crop-hail insurance, premium rate, short-term insurance data, spatial and temporal parameters

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Authors: Ezio Bassi, Francesco Vercesi, Francesco Benzi

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The aim of this study is to evaluate the potentiality of synchronous reluctance motors for lift systems by also evaluating the vibroacoustic behaviour of the motor. Two types of synchronous machines are designed, analysed, and compared with an equivalent induction motor, which is the more common solution in such gearbox applications. The machines' performance are further improved with optimization procedures based on multiobjective optimization genetic algorithm (MOGA). The difference between the two synchronous motors consists in the rotor geometry; a symmetric and an asymmetric rotor design were investigated. The evaluation of the vibroacoustic performance has been conducted with a multi-variable model and finite element software taking into account electromagnetic, mechanical, and thermal features of the motor, therefore carrying out a multi-physics analysis of the electrical machine.

Keywords: synchronous reluctance motor, vibro-acoustic, lift systems, genetic algorithm

Procedia PDF Downloads 178

Authors: G. A. Asciak, C. Camilleri, A. Rizzo

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The waste management in Malta is a national challenge. Coupled with Malta’s recent economic boom, which has seen massive growth in several sectors, especially the construction industry, drastic actions need to be taken. Wood waste, currently being dumped in landfills, is one type of waste which has increased astronomically. This research study aims to carry out a thorough examination on the possibility of using this waste as a biomass resource and adopting a waste-to-energy technology in order to generate electrical energy. This study is composed of three distinct yet interdependent phases, namely, data collection from the local SMEs, thermal analysis using the bomb calorimeter, and generation of energy from wood waste using a micro biomass plant. Data collection from SMEs specializing in wood works was carried out to obtain information regarding the available types of wood waste, the annual weight of imported wood, and to analyse the manner in which wood shavings are used after wood is manufactured. From this analysis, it resulted that five most common types of wood available in Malta which would suitable for generating energy are Oak (hardwood), Beech (hardwood), Red Beech (softwood), African Walnut (softwood) and Iroko (hardwood). Subsequently, based on the information collected, a thermal analysis using a 6200 Isoperibol calorimeter on the five most common types of wood was performed. This analysis was done so as to give a clear indication with regards to the burning potential, which will be valuable when testing the wood in the biomass plant. The experiments carried out in this phase provided a clear indication that the African Walnut generated the highest gross calorific value. This means that this type of wood released the highest amount of heat during the combustion in the calorimeter. This is due to the high presence of extractives and lignin, which accounts for a slightly higher gross calorific value. This is followed by Red Beech and Oak. Moreover, based on the findings of the first phase, both the African Walnut and Red Beech are highly imported in the Maltese Islands for use in various purposes. Oak, which has the third highest gross calorific value is the most imported and common wood used. From the five types of wood, three were chosen for use in the power plant on the basis of their popularity and their heating values. The PP20 biomass plant was used to burn the three types of shavings in order to compare results related to the estimated feedstock consumed by the plant, the high temperatures generated, the time taken by the plant to produce gasification temperatures, and the projected electrical power attributed to each wood type. From the experiments, it emerged that whilst all three types reached the required gasification temperature and thus, are feasible for electrical energy generation. African Walnut was deemed to be the most suitable fast-burning fuel. This is followed by Red-beech and Oak, which required a longer period of time to reach the required gasification temperatures. The results obtained provide a clear indication that wood waste can not only be treated instead of being dumped in dumped in landfill but coupled.

Keywords: biomass, isoperibol calorimeter, waste-to-energy technology, wood

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Authors: Reshma Jolly, Mohammad Shakir, Mohammad Shoeb Khan, Noor E. Iram

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A nanocomposite system integrating hydroxyapatite, chitin and starch (n-HA/CT/ST) has been synthesized via co-precipitation approach at room temperature, addressing the issues of biocompatibility, mechanical strength and cytotoxicity required for Bone tissue engineering. The interactions, crystallite size and surface morphology against n-HA/CT (nano-hydroxyapatite/chitin) nanocomposite have been obtained by correlating and comparing the results of FTIR, SEM, TEM and XRD. The comparative study of the bioactivity of n-HA/CT and n-HA/CT/ST nanocomposites revealed that the incorporation of starch as templating agent improved these properties in n-HA/CT/ST nanocomposite. The rise in thermal stability in n-HA/CT/ST nanocomposite as compared to n-HA/CT has been observed by comparing the TGA results. The comparison of SEM images of both the scaffolds indicated that the addition of ST influenced the surface morphology of n-HA/CT scaffold which appeared to be rougher and porous. The MTT assay on murine fibroblast L929 cells and in-vitro bioactivity of n-HA/CT/ST matrix referred superior non-toxic property of n-HA/CT/ST nanocomposite and higher possibility of osteo-integration in-vivo, respectively.

Keywords: bioactive, chitin, hyroxyapatite, nanocomposite

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Authors: M. El-Eraki, A. A. Mohamed, A. A. El-Kenawy, M. S. Toni, S. I. Mustafa

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The aim of this paper is to study the ground vibrations using Nakamura technique to evaluate the relation between the ground conditions and the earthquake characteristics. Microtremor measurements were carried out at 55 sites in and around Zagazig city. The signals were processed using horizontal to vertical spectral ratio (HVSR) technique to estimate the fundamental frequencies of the soil deposits and its corresponding H/V amplitude. Seismic measurements were acquired at nine sites for recording the surface waves. The recorded waveforms were processed using the multi-channel analysis of surface waves (MASW) method to infer the shear wave velocity profile. The obtained fundamental frequencies were found to be ranging from 0.7 to 1.7 Hz and the maximum H/V amplitude reached 6.4. These results together with the average shear wave velocity in the surface layers were used for the estimation of the thickness of the upper most soft cover layers (depth to bedrock). The sediment thickness generally increases at the northeastern and southwestern parts of the area, which is in good agreement with the local geological structure. The results of this work showed the zones of higher potential damage in the event of an earthquake in the study area.

Keywords: ambient vibrations, fundamental frequency, surface waves, zagazig

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Authors: Gholamreza Koochaki

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This paper presents the buckling analysis of functionally graded beams with various boundary conditions. The first order shear deformation beam theory (Timoshenko beam theory) and the classical theory (Euler-Bernoulli beam theory) of Reddy have been applied to the functionally graded beams buckling analysis The material property gradient is assumed to be in thickness direction. The equilibrium and stability equations are derived using the total potential energy equations, classical theory and first order shear deformation theory assumption. The temperature difference and applied voltage are assumed to be constant. The critical buckling temperature of FG beams are upper than the isotropic ones. Also, the critical temperature is different for various boundary conditions.

Keywords: buckling, functionally graded beams, Hamilton's principle, Euler-Bernoulli beam

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Authors: Yasmeen F. Pervez, Etesh K. Janghel, Santosh Kumar Sar

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Simple and sensitive analytical thermal gradient-thin layer chromatography technique has been developed for the simultaneous determination of phenolic pesticides like carbaryl, propoxur and carbofuran. It is based on the differential migration of colored derivatives formed by the reaction of hydrolysed phenolic compound with diazotized 3, 4 dimethyl aniline on a silica gel plate. Quantitative evaluation of hydrolyzed phenolic compound is made by visual comparison of intensities of color by spectrophotometry. The color system obeys Beer’s law in the following working range in ppm : carbaryl, 0.5-6.6; propoxur, 0.8-7.2; and carbofuran, 0.2-3.3 respectively. The Molar absorptivity, Sandell’s sensitivity, Correlation coefficient have been determined. The effects of analytical parameters on migration and analysis have been evaluated. The methods are highly reproducible and have been successfully applied to determination of phenolic pesticides in environmental and biological samples.

Keywords: phenolic pesticides (carbaryl, propoxur and carbofuran), 3.4 dimethyl aniline, environmental, biological samples

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Authors: Oliver Mărunţălu, Gheorghe Lăzăroiu, Elena Elisabeta Manea, Dana Andreya Bondrea, Lăcrămioara Diana Robescu

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This paper presents the results obtained by numerical simulation of the pollutants dispersion in the atmosphere coming from the evacuation of combustion gases resulting from the fuel combustion used by electric thermal power plant using the software ANSYS CFX-CFD. The model uses the Navier-Stokes equation to simulate the dispersion of pollutants in the atmosphere. We considered as important factors in elaboration of simulation the atmospheric conditions (pressure, temperature, wind speed, wind direction), the exhaust velocity of the combustion gases, chimney height and the obstacles (buildings). Using the air quality monitoring stations we have measured the concentrations of main pollutants (SO2, NOx and PM). The pollutants were monitored over a period of 3 months, after that we calculated the average concentration, which is used by the software. The concentrations are: 8.915 μg/m3 (NOx), 9.587 μg/m3 (SO2) and 42 μg/m3 (PM). A comparison of test data with simulation results demonstrated that CFX was able to describe the dispersion of the pollutant as well the concentration of this pollutants in the atmosphere.

Keywords: air pollutants, computational fluid dynamics, dispersion, simulation

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Authors: Nazila Dehbari, Javad Tavakoli, Yakani Kambu, Youhong Tang

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Superabsorbent hydrogels (SAP), as an enviro-sensitive material have been widely used for industrial and biomedical applications due to their unique structure and capabilities. Poor mechanical properties of SAPs - which is extremely related to their large volume change – count as a great weakness in adopting for high-tech applications. Therefore, improving SAPs’ mechanical properties via toughening methods by mixing different types of cross-linked polymer or introducing energy-dissipating mechanisms is highly focused. In this work, in order to change the intrinsic brittle character of commercialized Poly Acrylic Acid (here as SAP) to be semi-ductile, a commercial available highly branched tree-like dendritic polymers with numerous –OH end groups known as hyper-branched polymer (HB) has been added to PAA-SAP system in a single step, cost effective and environment friendly solvent casting method. Samples were characterized by FTIR, SEM and TEM and their physico-chemical characterization including swelling capabilities, hydraulic permeability, surface tension and thermal properties had been performed. Toughness energy, stiffness, elongation at breaking point, viscoelastic properties and samples extensibility were mechanical properties that had been performed and characterized as a function of samples lateral cracks’ length in different HB concentration. Addition of HB to PAA-SAP significantly improved mechanical and surface properties. Increasing equilibrium swelling ratio by about 25% had been experienced by the SAP-HB samples in comparison with SAPs; however, samples swelling kinetics remained without changes as initial rate of water uptake and equilibrium time haven’t been subjected to any changes. Thermal stability analysis showed that HB is participating in hybrid network formation while improving mechanical properties. Samples characterization by TEM showed that, the aggregated HB polymer binders into nano-spheres with diameter in range of 10–200 nm. So well dispersion in the SAP matrix occurred as it was predictable due to the hydrophilic character of the numerous hydroxyl groups at the end of HB which enhance the compatibility of HB with PAA-SAP. As the profused -OH groups in HB could react with -COOH groups in the PAA-SAP during the curing process, the formation of a 2D structure in the SAP-HB could be attributed to the strong interfacial adhesion between HB and the PAA-SAP matrix which hinders the activity of PAA chains (SEM analysis). FTIR spectra introduced new peaks at 1041 and 1121 cm-1 that attributed to the C–O(–OH) stretching hydroxyl and O–C stretching ester groups of HB polymer binder indicating the incorporation of HB polymer into the SAP structure. SAP-HB polymer has significant effects on the final mechanical properties. The brittleness of PAA hydrogels are decreased by introducing HB as the fracture energies of hydrogels increased from 8.67 to 26.67. PAA-HBs’ stretch ability enhanced about 10 folds while reduced as a function of different notches depth.

Keywords: superabsorbent polymer, toughening, viscoelastic properties, hydrogel network

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Authors: Raghda El-Nagara, Maher I. Nessim, Carmen E. Elshafee, Renee I. Abdallah, Yasser M. Moustafa

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Three asymmetric dicationic ionic liquids (ADILs), 1-(2-(1-dodecyl-2-methyl-1H-imidazolium-3-yl)ethyl)-3-methyl pyridinium bromide (IL₁), 1-(6-(1-dodecyl-2-methyl-1H-imidazolium-3-yl)hexyl)-3-methyl pyridinium bromide (IL₂) and 1-(10-(1-dodecyl-2-methyl-1H-imidazolium-3-yl)decyl)-3-methyl pyridinium bromide (IL₃) were synthesized with yield of 83.54, 84.12 & 83.05% respectively. They were elucidated via conventional tools of analysis (elemental analysis, FT-IR, and 1H-NMR). The thermogravimetric analysis confirmed that the three ADILs possessed high thermal stability (up to 500ᵒC). Their critical micelle concentration (CMC) was investigated and exhibited values of 5.5-1*10⁻³ Mol./L. They were evaluated as oil spill dispersants were at different temperatures (10, 30 & 50ᵒC) with different concentrations (750, 1500, 2000, 3000 ppm). Data reveals that the efficiency is ranked as follows: IL₂ > IL₁ > IL₃, which showed high dispersion efficiency reached to 63% with the concentration of 1500 ppm.

Keywords: ionic liquids, amphiphilic, oil spill dispersants, dicationic, efficiency test

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Authors: Cyril O. Ehi-Eromosele, Ajayi Kayode

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The Li-rich layered metal oxides (LLO) are the most promising candidates for promising electrodes of high energy Li-ion battery (LIB). In literature, these electrode system has either been designed as a hetero-structure of the primary components (composite) or as a core-shell structure with improved electrochemistry reported for both configurations when compared with its primary components. With the on-going efforts to improve on the electrochemical performance of the LIB, it is important to investigate comparatively the structural and electrochemical characteristics of the core-shell like and ‘composite’ forms of these materials with the same compositions and synthesis conditions which could influence future engineering of these materials. Therefore, this study concerns the structural and electrochemical properties of the ‘composite’ and core-shell like LLO cathode materials with the same nominal composition of 0.5Li₂MnO₃-0.5LiNi₀.₅Mn₀.₃Co₀.₂O₂ (LiNi₀.₅Mn₀.₃Co₀.₂O₂ as core and Li₂MnO₃ as the shell). The results show that the core-shell sample (–CS) gave better electrochemical performance than the ‘composite’ sample (–C). Both samples gave the same initial charge capacity of ~300 mAh/g when cycled at 10 mA/g and comparable charge capacity (246 mAh/g for the –CS sample and 240 mAh/g for the –C sample) when cycled at 200 mA/g. However, the –CS sample gave a higher initial discharge capacity at both current densities. The discharge capacity of the –CS sample was 232 mAh/g and 164 mAh/g while the –C sample is 208 mAh/g and 143 mAh/g at the current densities of 10 mA/g and 200 mA/g, respectively. Electrochemical impedance spectroscopy (EIS) results show that the –CS sample generally exhibited a smaller resistance than the –C sample both for the uncycled and after 50th cycle. Detailed structural analysis is on-going, but preliminary results show that the –CS sample had bigger unit cell volume and a higher degree of cation mixing. The thermal stability of the –CS sample was higher than the –C sample. XPS investigation also showed that the pristine –C sample gave a more reactive surface (showing formation of carbonate species to a greater degree) which could result in the greater resistance seen in the EIS result. To reinforce the results obtained for the 0.5Li₂MnO₃-0.5LiNi₀.₅Mn₀.₃Co₀.₃O₂ composition, the same investigations were extended to another ‘composite’ and core-shell like LLO cathode materials also with the same nominal composition of 0.5Li₂MnO₃-0.5LiNi₀.₃Mn₀.₃Co₀.₃O₂. In this case, the aim was to determine the electrochemical performance of the material using a low Ni content (LiNi₀.₃Mn₀.₃Co₀.₃O₂) as the core to clarify the contributions of the core-shell configuration to the electrochemical performance of these materials. Ni-rich layered oxides show active catalytic surface leading to electrolyte oxidation resulting in poor thermal stability and cycle life. Here, the core-shell sample also gave better electrochemical performance than the ‘composite’ sample with 0.5Li₂MnO₃-0.5LiNi₀.₃Mn₀.₃Co₀.₃O₂ composition. Furthermore, superior electrochemical performance was also recorded for the core-shell like spinel modified LLO (0.5Li₂MnO₃-0.45LiNi₀.₅Mn₀.₃Co₀.₂O₂-0.05LiNi₀.₅Mn₁.₅O₄) when compared to the composite system. These results show that the core-shell configuration can generally be used to improve the structural and electrochemical properties of the LLO and spinel modified LLO materials.

Keywords: lithium-ion battery, lithium rich oxide cathode, core-shell structure, composite structure

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Authors: Shi-Yu Xu

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The top three risk factors that have contributed to building collapses during past earthquake events in Taiwan are: "irregular floor plans or elevations," "insufficient columns in single-bay buildings," and the "weak-story problem." Fortunately, these unsound structural characteristics can be directly identified from the floor plans. However, due to the vast number of old buildings, conducting manual inspections to identify these compromised structural features in all existing structures would be time-consuming and prone to human errors. This study aims to develop an algorithm that utilizes artificial intelligence techniques to automatically pinpoint the structural components within a building's floor plans. The obtained spatial information will be utilized to construct a digital structural model of the building. This information, particularly regarding the distribution of columns in the floor plan, can then be used to conduct preliminary seismic assessments of the building. The study employs various image processing and pattern recognition techniques to enhance detection efficiency and accuracy. The study enables a large-scale evaluation of structural vulnerability for numerous old buildings, providing ample time to arrange for structural retrofitting in those buildings that are at risk of significant damage or collapse during earthquakes.

Keywords: structural vulnerability detection, object recognition, seismic capacity assessment, old buildings, artificial intelligence

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Authors: Nicolas Lipchak, Franco Aiducic, Santiago Baieli

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The present work is a part of the research project called ‘Testing of gas turbine KingTech with biodiesel’, carried out by the Department of Industrial Engineering of the National Technological University at Buenos Aires. The research group aims to experiment with biodiesel in a gas turbine Kingtech K-100 to verify the correct operation of it. In this sense, tests have been developed to obtain real data of parameters inherent to the work cycle, to be used later as parameters of comparison and performance analysis. In the first instance, the study consisted in testing the gas turbine with a mixture composition of 50% Biodiesel and 50% Diesel. The parameters arising from the measurements made were compared with the parameters of the gas turbine with a composition of 100% Diesel. In the second instance, the measured parameters were used to calculate the power generated and the thermal efficiency of the Kingtech K-100 turbine. The turbine was also inspected to verify the status of the internals due to the use of biofuels. The conclusions obtained allow empirically demonstrate that it is feasible to use biodiesel in this type of gas turbines, without the use of this fuel generates a loss of power or degradation of internals.

Keywords: biodiesel, efficiency, KingTech, turbine

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Authors: Hilary Limo Rutto

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To better understand the application of diatomite as an adsorbent for the removal of Pb2+ from heavy metal-contaminated water, in this paper, diatomite was used to adsorb Pb2+ from aqueous solution under various conditions. The intrinsic exchange properties were further improved by heating the raw diatomite with fluxing agent at different temperatures and modification with manganese oxides. It is evident that the mass of the adsorbed Pb2+ generally increases after thermal treatment and modification with manganese oxides. The adsorption characteristics of lead on diatomite were studied at pH range of 2.5–12. The favourable pH range was found to be 7.5-8.5. The thermodynamic parameters (i.e.,∆H° ∆G° ∆S°) were evaluated from the temperature dependent adsorption isotherms. The results indicated that the adsorption process of Pb2+ on diatomite was spontaneous, endothermic and physical in nature. The equilibrium data have been analyzed using Langmuir and freundlich isotherm. The Langmuir isotherm was demonstrated to provide the best correlation for the adsorption of lead onto diatomite. The kinetics was studied using Pseudo- first and second-order model on the adsorption of lead onto diatomite. The results give best fit in second-order studies and it can be concluded that the adsorption of lead onto diatomite is second order reaction.

Keywords: thermally modified, diatomite, adsorption, lead

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Authors: Kambiz Hassanzadeh, Seyedeh Shohreh Ebrahimi, Shahrbanoo Oryan, Arman Rahimmi, Esmael Izadpanah

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Parkinson’s disease is one of the most prevalent neurodegenerative diseases which occurs in elderly. There are convincing evidences that oxidative stress has an important role in both the initiation and progression of Parkinson’s disease. Thymoquinone (TQ) is shown to have antioxidant and anti-inflammatory properties in invitro and invivo studies. It is well documented that TQ acts as a free radical scavenger and prevents the cell damage. Therefore this study aimed to evaluate the effect of TQ on motor and non-motor symptoms in animal model of Parkinson’s disease. Male Wistar rats (10-12 months) received rotenone (1mg/kg/day, sc) to induce Parkinson’s disease model. Pretreatment with TQ (7.5 and 15 mg/kg/day, po) was administered one hour before the rotenone injection. Three motor tests (rotarod, rearing and bar tests) and two non-motor tests (forced swimming and elevated plus maze) were performed for behavioral assessment. Our results indicated that TQ significantly ameliorated the rotenone-induced motor dysfunction in rotarod and rearing tests also it could prevent the non-motor dysfunctions in forced swimming and elevated plus maze tests. In conclusion we found that TQ delayed the Parkinson's disease induction by rotenone and this effect might be related to its proved antioxidant effect.

Keywords: Parkinson's disease, thymoquinone, motor and non-motor symptoms, neurodegenerative disease

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Authors: A. M. Gheitaghy, H. Saffari, G. Q. Zhang

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Numerical approach based on the electrical simulation method is proposed to solve a nonlinear transient heat conduction problem with nonlinear boundary for a spherical body. This problem represents a strong nonlinearity in both the governing equation for temperature dependent thermal property and the boundary condition for combined convective and radiative cooling. By analysing the equivalent electrical model using the electrical circuit simulation program HSPICE, transient temperature and heat flux distributions at sphere can be obtained easily and fast. The solutions clearly illustrate the effect of the radiation-conduction parameter Nrc, the Biot number and the linear coefficient of temperature dependent conductivity and heat capacity. On comparing the results with corresponding numerical solutions, the accuracy and efficiency of this computational method are found to be good.

Keywords: convective and radiative boundary, electrical simulation method, nonlinear heat conduction, spherical coordinate

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Authors: Renu Yadav, Sanjeev Kumar

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In northern India, chickpea (Cicer arietinum L.) come across with terminal high-temperature stress during reproductive stage which leads to reduced yield. Hence, stable production of chickpea will depend on the development of new methods like ‘priming’ which allow improved adaptation to the drought and heat stress. In the present experiment, 11-day chickpea seedling was primed with mild drought stress and put on recovery stage by irrigating and finally 30-day seedlings were exposed to heat stress 38°C (4 hours), 35°C (8 hours) and 32°C (12 hours). To study the effect of combinatorial stress, heat and drought stress was applied simultaneously. Analyses of various physiological parameters like membrane damage assay, photosynthetic pigments, antioxidative enzyme, total sugars were estimated at all stages. To study the effect of heat stress on the metabolites of the plants, GC-MS and HPLC were performed, while at transcriptional level Real-Time PCR of predicted heat stress-related genes was done. It was concluded that the heat stress significantly affected the chickpea plant at physiological and molecular level in all the five varieties. Results also show less damaging effect in primed plants by increasing the activity of antioxidative enzymes and increased expression of heat shock proteins and heat shock factors.

Keywords: chickpea, combinatorial stress, heat stress, oxidative stress, priming, RT-PCR

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Authors: Sharmin Sultana, Nicolas Nuns, Pardis Simon, Jean-Marc Giraudon, Jean-Francois Lamonior, Nathalie D. Geyter, Rino Morent

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Environmental issues, especially air pollution, have become a huge concern of environmental legislation as a consequence of growing awareness in our global world. In this regard, control of volatile organic compounds (VOCs) emission has become an important issue due to their potential toxicity, carcinogenicity, and mutagenicity. The research of innovative technologies for VOC abatement is stimulated to accommodate the new stringent standards in terms of VOC emission. One emerging strategy is the coupling of 2 existing complementary technologies, namely here non-thermal plasma (NTP) and heterogeneous catalysis, to get a more efficient process for VOC removal in air. The objective of this current work is to investigate the abatement of trichloroethylene (TCE-highly toxic chlorinated VOC) from moist air (RH=15%) as a function of time by combined use of multi-pin-to-plate negative DC corona/glow discharge with Fe-doped cryptomelanes catalyst downstream i.e. post plasma-catalysis (PPC) process. For catalyst alone case, experiments reveal that, initially, Fe doped cryptomelane (regardless the mode of Fe incorporation by co-precipitation (Fe-K-OMS-2)/ impregnation (Fe/K-OMS-2)) exhibits excellent activity to decompose TCE compared to cryptomelane (K-OMS-2) itself. A maximum obtained value of TCE abatement after 6 min is as follows: Fe-KOMS-2 (73.3%) > Fe/KOMS-2 (48.5) > KOMS-2 (22.6%). However, with prolonged operation time, whatever the catalyst under concern, the abatement of TCE decreases. After 111 min time of exposure, the catalysts can be ranked as follows: Fe/KOMS-2 (11%) < K-OMS-2 (12.3%) < Fe-KOMS-2 (14.5%). Clearly, this phenomenon indicates catalyst deactivation either by chlorination or by blocking the active sites. Remarkably, in PPC configuration (energy density = 60 J/L, catalyst temperature = 150°C), experiments reveal an enhanced performance towards TCE removal regardless the type of catalyst. After 6 min time on stream, the TCE removal efficiency amount as follows: K-OMS-2 (60%) < Fe/K-OMS-2 (79%) < Fe-K-OMS-2 (99.3%). The enhanced performances over Fe-K-OMS-2 catalyst are attributed to its high surface oxygen mobility and structural defects leading to high O₃ decomposition efficiency to give active species able to oxidize the plasma processed hazardous\by-products and the possibly remaining VOC into CO₂. Moreover, both undoped and doped catalysts remain strongly capable to abate TCE with time on stream. The TCE removal efficiencies of the PPC processes with Fe/KOMS-2 and KOMS-2 catalysts are not affected by time on stream indicating an excellent catalyst stability. When using the Fe-K-OMS-2 as catalyst, TCE abatement slightly reduces with time on stream. However, it is noteworthy to stress that still a constant abatement of 83% is observed during at least 30 minutes. These results prove that the combination of NTP with catalysts not only increases the catalytic activity but also allows to avoid, to some extent, the poisoning of catalytic sites resulting in an enhanced catalyst stability. In order to better understand the different surface processes occurring in the course of the total TCE oxidation in PPC experiments, a detailed X-ray Photoelectron Spectroscopy (XPS) and Time of Flight-Secondary Ion Mass Spectrometry (ToF-SIMS) study on the fresh and used catalysts is in progress.

Keywords: Fe doped cryptomelane, non-thermal plasma, plasma-catalysis, stability, trichloroethylene

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Authors: Augustas Vaitkevicius, Mikhail Korjik, Eugene Tretyak, Ekaterina Trusova, Gintautas Tamulaitis

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Silicate materials are widely used as luminescent materials in amorphous and crystalline phase. Lithium silicate glass is popular for making neutron sensitive scintillation glasses. Cerium-doped single crystalline silicates of rare earth elements and yttrium have been demonstrated to be good scintillation materials. Due to their high thermal and photo-stability, silicate glass ceramics are supposed to be suitable materials for producing light converters for high power white light emitting diodes. In this report, the influence of glass composition and crystallization on photoluminescence (PL) of different silicate glasses was studied. Barium (BaO-2SiO₂) and lithium (Li₂O-2SiO₂) glasses were under study. Cerium, dysprosium, erbium and europium ions as well as their combinations were used for doping. The influence of crystallization was studied after transforming the doped glasses into glass ceramics by heat treatment in the temperature range of 550-850 degrees Celsius for 1 hour. The study was carried out by comparing the photoluminescence (PL) spectra, spatial distributions of PL parameters and quantum efficiency in the samples under study. The PL spectra and spatial distributions of their parameters were obtained by using confocal PL microscopy. A WITec Alpha300 S confocal microscope coupled with an air cooled CCD camera was used. A CW laser diode emitting at 405 nm was exploited for excitation. The spatial resolution was in sub-micrometer domain in plane and ~1 micrometer perpendicularly to the sample surface. An integrating sphere with a xenon lamp coupled with a monochromator was used to measure the external quantum efficiency. All measurements were performed at room temperature. Chromatic properties of the light emission from the glasses and glass ceramics have been evaluated. We observed that the quantum efficiency of the glass ceramics is higher than that of the corresponding glass. The investigation of spatial distributions of PL parameters revealed that heat treatment of the glasses leads to a decrease in sample homogeneity. In the case of BaO-2SiO₂: Eu, 10 micrometer long needle-like objects are formed, when transforming the glass into glass ceramics. The comparison of PL spectra from within and outside the needle-like structure reveals that the ratio between intensities of PL bands associated with Eu²⁺ and Eu³⁺ ions is larger in the bright needle-like structures. This indicates a higher degree of crystallinity in the needle-like objects. We observed that the spectral positions of the PL bands are the same in the background and the needle-like areas, indicating that heat treatment imposes no significant change to the valence state of the europium ions. The evaluation of chromatic properties confirms applicability of the glasses under study for fabrication of white light sources with high thermal stability. The ability to combine barium and lithium glass matrixes and doping by Eu, Ce, Dy, and Tb enables optimization of chromatic properties.

Keywords: glass ceramics, luminescence, phosphor, silicate

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Authors: Anas Fadlelmula, Elsafi M. M. Ahmed

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The efficacy of Defender 2% WS (tebuconazole) and Imidal 70 WS (imidacloprid) to control damping-off diseases and early insect pests in sesame crop under rain fed conditions at Damazine and Gedarif areas was evaluated. Defender 2% WS with dosage rates 0.5, 0.75, 1.0 and 1.25 g/kg of seeds and Imidal 70 WS at 2.25, 3.0, and 3.75 g/ kg of seeds were tested singly and as a mixture during 2010/2011 and 2012/013. Sesame seeds treated with Defender at the rates of 0.5 g and 0.75 g/ kg of seeds gave a high significant increase in percent seedlings emergence (84% and 85%) respectively. Imidal 70 WS at rate of 3g/kg seed showed the least percent damaged leaves by sesame webworm (1.7%). However, the mixed Defender at rate 0.75g with Imidal at 3 g/kg seed, significantly gave a highest percentage of sesame seedling emergence (85.1%) and reduced the incidence of post-emergence damping off and percent damaged leaves to the least per cent (2.1% and 0.4% ) respectively, compared to other treatments. Consequently, the mixed treatment of 0.75 g of Defender + 3 g of Imidal improved the crop stand and significantly gave the highest yield (405.2 kg and 418.8 kg/fed) respectively in both sites compared to the other treatments.

Keywords: seed dressers, damage, daming off, insects

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Authors: Hulya Tuba Kiyan, Nilgun Ozturk

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Gentiana, a member of Gentianaceae, is represented by approximately 400 species in the world and 12 species in Turkey. Flavonoids, iridoids, triterpenoids and also xanthones are the major compounds of this genus, have been previously reported to have antiinflammatory, antimicrobial, antioxidant, hepatoprotective, hypotensive, hypoglycaemic, DNA repair and immunomodulatory properties. The methanolic extract of the aerial parts of Gentiana brachyphylla Vill. from Turkey was evaluated for its biological activities and its total phenolic content in the present study. According to the antioxidant activity results, G. brachyphylla methanolic extract showed very strong anti-DNA damage antioxidant activity with an inhibition of 81.82%. It showed weak ferric-reducing power with a EC50 value of 0.65 when compared to BHT (EC50 = 0.2). Also, at 0.5 mg/ml concentration, the methanolic extract inhibited ABTS radical cation activity with an inhibition of 20.13% when compared to Trolox (79.01%). Chelating ability of G. brachyphylla was 44.71% whereas EDTA showed 78.87% chelating activity at 0.2 mg/ml. Also G. brachyphylla showed weak 27.21% AChE, 20.23% BChE, strong 67.86% MAO-A and moderate 50.06% MAO-B, weak 19.14% COX-1, 29.11% COX-2 inhibitory activities at 0.25 mg/ml. The total phenolic content of G. brachyphylla was 156.23 ± 2.73 mg gallic acid equivalent/100 g extract.

Keywords: antioxidant activity, cholinesterase inhibitory activity, Gentiana brachyphylla Vill., total phenolic content

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Authors: Bharatkumar Sutaria, Tejaskumar Chaudhari

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An engine performance can be increased by minimizing losses. There are various losses observed in the engines. i.e. thermal loss, heat loss and mechanical losses. Mechanical losses are in the tune of 15 to 20 % of the overall losses. Piston ring assembly contributes the highest friction in the mechanical frictional losses. The variation of piston speed in stroke length the friction force development is not uniform. In present work, comparison has been made between theoretical and experimental friction force under different operating conditions. The experiments are performed using variable operating parameters such as load, speed, temperature and lubricants. It is found that reducing trend of friction force and friction coefficient is in good nature with mixed lubrication regime of the Stribeck curve. Overall outcome from the laboratory test performance of segmented piston ring assembly using multi-grade oil offers reasonably good results at room and elevated temperatures.

Keywords: friction force, friction coefficient, piston rings, Stribeck curve

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Authors: Manju Lata Sharma

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Damage to cells caused by free radicals is believed to play a central role in the ageing process and in disease progression. Withania somnifera is widely used in ayurvedic medicine, and it is one of the ingredients in many formulations to increase energy, improve overall health and longevity and prevent disease. Withania somnifera possesses antioxidative properties. The antioxdant activity of Withania somnifera consisting of an equimolar concentration of active principles of sitoindoside VII-X and withaferin A. The antioxidant effect of Withania somnifera extract was investigated on lipid peroxidation (LPO), superoxide dismutase (SOD) and catalase (CAT) activity in mice. Aim: To study the antioxidant activity of an extract of Withania somnifera leaf against a mice model of chronic stress. Healthy swiss albino mice (3-4 months old) selected from an inbred colony were divided in to 6 groups. Biochemical estimation revealed that stress induced a significant change in SOD, LPO, CAT AND GPX. These stress induced perturbations were attenuated Withania somnifera (50 and 100 mg/kg BW). Result: Withania somnifera tended to normalize the augmented SOD and LPO activities and enhanced the activities of CAT and GPX. The result indicates that treatment with an alcoholic extract of Withania somnifera produced a significant decrease in LPO ,and an increase in both SOD and CAT in brain mice. This indicates that Withania somnifera extract possesses free radical scavenging activity .

Keywords: Withania somnifera, antioxidant, lipid peroxidation, brain

Procedia PDF Downloads 366

Authors: Shweta Lall

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The intent of this paper is to demonstrate the role of computerized auxiliary science in advancing the desired and necessary alliance of historians, surveyors, topographers, and analysts of architectural conservation and management. The digital era practice of recording architectural and cultural heritage in view of its preservation, dissemination, and planning developments are discussed in this paper. Geomatics include practices like remote sensing, photogrammetry, surveying, Geographic Information System (GIS), laser scanning technology, etc. These all resources help in architectural and conservation applications which will be identified through various case studies analysed in this paper. The standardised outcomes and the methodologies using relevant case studies are listed and described. The main component of geomatics methodology adapted in conservation is data acquisition, processing, and presentation. Geomatics is used in a wide range of activities involved in architectural and cultural heritage – damage and risk assessment analysis, documentation, 3-D model construction, virtual reconstruction, spatial and structural decision – making analysis and monitoring. This paper will project the summary answers of the capabilities and limitations of the geomatics field in architectural and cultural conservation. Policy-makers, urban planners, architects, and conservationist not only need answers to these questions but also need to practice them in a predictable, transparent, spatially explicit and inexpensive manner.

Keywords: architectural and cultural conservation, geomatics, GIS, remote sensing

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Authors: M. A. Boukli Hacene, N. E.Chabane Sari, A. Benzair

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This article highlights a method for natural heating and cooling of systems in areas of moderate climate. Movement of air is generated inside a space by an underground piping system. In this paper, we discuss a feasibility study in Algeria of air-conditioning using a ground source heat pump (GSHP) with vertical mounting, coupled with a solar collector. This study consists of modeling ground temperature at different depths, for a clay soil in the city of Tlemcen. Our model is developed from the non-stationary heat equation for a homogeneous medium and takes into consideration the soil thermal diffusivity. It uses the daily ambient temperature during a typical year for the locality of Tlemcen. The study shows the feasibility of using a heating/cooling GSHP in the town of Tlemcen for the particular soil type; and indicates that the duration of air flow in the borehole has a major influence on the outgoing temperature drilling.

Keywords: green building, heat pump, insulation, climate change

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Authors: Omar Hamdy, Schichen Zhao, Hussein Abd El-Atty, Ayman Ragab, Muhammad Salem

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One of the most risky areas in Aswan is Abouelreesh, which is suffering from flood disasters, as heavy deluge inundates urban areas causing considerable damage to buildings and infrastructure. Moreover, the main problem was the urban sprawl towards this risky area. This paper aims to identify the urban areas located in the risk areas prone to flash floods. Analyzing this phenomenon needs a lot of data to ensure satisfactory results; however, in this case the official data and field data were limited, and therefore, free sources of satellite data were used. This paper used ArcGIS tools to obtain the storm water drains network by analyzing DEM files. Additionally, historical imagery in Google Earth was studied to determine the age of each building. The last step was to overlay the urban area layer and the storm water drains layer to identify the vulnerable areas. The results of this study would be helpful to urban planners and government officials to make the disasters risk estimation and develop primary plans to recover the risky area, especially urban areas located in torrents.

Keywords: risk area, DEM, storm water drains, GIS

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Authors: Abdulkarim Mohammed Iliyasu, Mahmud Abba Tahir

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Freezing and thawing are considered to be one of the major causes of concrete deterioration in the cold regions. This study aimed at assessing the freezing and thawing of concrete within the cover zone by monitoring the formation of ice and melting at different temperatures using electrical measurement technique. A multi-electrode array system was used to obtain the resistivity of ice formation and melting at discrete depths within the cover zone of the concrete. A total number of four concrete specimens (250 mm x 250 mm x 150 mm) made of ordinary Portland cement concrete and ordinary Portland cement replaced by 65% ground granulated blast furnace slag (GGBS) is investigated. Water/binder ratios of 0.35 and 0.65 were produced and ponded with water to ensure full saturation and then subjected to freezing and thawing process in a refrigerator within a temperature range of -30 ⁰C and 20 ⁰C over a period of time 24 hours. The data were collected and analysed. The obtained results show that the addition of GGBS changed the pore structure of the concrete which resulted in the decrease in conductance. It was recommended among others that, the surface of the concrete structure should be protected as this will help to prevent the instantaneous propagation of ice trough the rebar and to avoid corrosion and subsequent damage.

Keywords: concrete, conductance, deterioration, freezing and thawing

Procedia PDF Downloads 417

Authors: Marek Halenár, Eva Tvrdá, Simona Baldovská, Ľubomír Ondruška, Peter Massányi, Adriana Kolesárová

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This study aimed to assess the in vitro effects of different concentrations of the Viscum album extract on the motility, viability, and reactive oxygen species (ROS) production by rabbit spermatozoa during different time periods (0, 2, and 8h). Spermatozoa motility was assessed by using the CASA (Computer aided sperm analysis) system. Cell viability was evaluated by using the metabolic activity MTT assay, and the luminol-based luminometry was applied to quantify the ROS formation. The CASA analysis revealed that low Viscum concentrations were able to prevent a rapid decline of spermatozoa motility, especially in the case of concentrations ranging between 1 and 5 µg/mL (P<0.05 with respect to time 8h). At the same time, concentrations ranging between 1 and 100 µg/mL of the extract led to a significant preservation of the cell viability (P<0.05 in case of 5, 50 and 100 µg/mL; P<0.01 with respect to 1 and 10 µg/mL, time 8h). 1 and 5 µg/mL of the extract exhibited antioxidant characteristics, translated into a significant reduction of the ROS production, particularly notable at time 8h (P<0.01). The results indicate that the Viscum extract is capable of delaying the damage inflicted to the spermatozoon by the in vitro environment.

Keywords: CASA, mistletoe, mitochondrial activity, motility, reactive oxygen species, rabbits, spermatozoa, Viscum album

Procedia PDF Downloads 394