Search results for: diffusion effect
12452 Perceived Impact of Climate Change on the Livelihood of Arable Crop Farmers in Ipokia Local Government Area of Ogun State, Nigeria
Authors: Emmanuel Olugbenga Fakoya
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The study examined the perceived impact of climate change on the livelihood of arable crop farmers in Ipokia Local Government Area of Ogun State, Nigeria. Multistage sampling technique was used to select 80 arable crop farmers in the study area. Data collected were analyzed using percentages, frequencies and Chi square analysis. The result showed that 63.8 percent of the respondents were male while 55.0 percent were married. Less than half (30.0 percent) of the respondents were between the age bracket of 41-50 years and 50.0 percent had 6-10 household size. Furthermore, majority (40.0 percent) of the arable crop farmers farmed on an inherited land and 51.3 percent had 2-3 hectares of land. Majority (38.8 percent) of the farmers intercrop maize with cassava and maize with yam. Various strategies adapted to reduce the effect of climate change on their crop and livelihood include: crop rotation (53.8 percent), planting of leguminous crop (35.0 percent), application of organic fertilizers (45.0 percent), mulching (56.3 percent) and by planting drought resistance crops (46.5 percent). Reported among the effects of climate change on crop and farmers’ livelihood were: discoloration of crop leave (63.8 percent), increase infestation of pests and diseases (58.8 percent) and reduction of crop yield (60.0 percent). Chi- square analysis showed significant relationship between impact of climate change on arable crop production and thus famers’ livelihood. It was concluded from the study that climate change is an impinging factor that seriously affect arable crop production and hence farmers’ livelihood despite coping strategies to minimize its effect. It was however recommended that Agricultural policies and practices that could minimize or eliminate its effect should be seriously enacted to boost production and increase farmers’ livelihood.Keywords: agricultural extension, extension agent, private sector, perception
Procedia PDF Downloads 43412451 Thermo-Mechanical Characterization of MWCNTs-Modified Epoxy Resin
Authors: M. Dehghan, R. Al-Mahaidi, I. Sbarski
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An industrial epoxy adhesive used in Carbon Fiber Reinforced Polymer (CFRP)-strengthening systems was modified by dispersing multi-walled carbon nanotubes (MWCNTs). Nanocomposites were fabricated using solvent-assisted dispersion method and ultrasonic mixing. Thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and tensile tests were conducted to study the effect of nanotubes dispersion on the thermal and mechanical properties of the epoxy composite. Experimental results showed a substantial enhancement in the decomposition temperature and tensile properties of epoxy composite, while, the glass transition temperature (Tg) was slightly reduced due to the solvent effect. The morphology of the epoxy nanocomposites was investigated by SEM. It was proved that using solvent improves the nanotubes dispersion. However, at contents higher than 2 wt. %, nanotubes started to re-bundle in the epoxy matrix which negatively affected the final properties of epoxy composite.Keywords: carbon fiber reinforced polymer, epoxy, multi-walled carbon nanotube, DMA, glass transition temperature
Procedia PDF Downloads 33112450 Effect of Pre-treatment with Salicylic Acid on Vegetative Growth and Yield Components of Wheat under Salinity
Authors: Saad M. Howladar, Mike Dennett
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At first harvest, results showed that salinity (tap water, 100 and 200 mM NaCl) induced a significant decrease in all growth parameters in both Yecora Rojo and Paragon cultivars. The greatest effect of salinity was a decrease in leaf area. The same tendency was observed with specific leaf area, and total fresh and dry weights and their components. Green leaf and tiller numbers were reduced by the same extent in both cultivars. The corresponding final harvest, all growth parameters also reduced with increased salinity. Yield and yield components were also reduced by salinity with similar effects in both cultivars. Chlorophyll fluorescence, expressed as Fv/Fm, and gas exchange parameters were decreased significantly with increase in salinity in both cultivars. In contrast, seed protein content was increased significantly with increase in salinity. Salicylic acid (SA) application induced no significant improvements in growth parameters and yield components.Keywords: salinity, salicylic acid, growth, chlorophyll fluorescence, gas exchange, yield
Procedia PDF Downloads 46312449 Effect of Core Puncture Diameter on Bio-Char Kiln Efficiency
Authors: W. Intagun, T. Khamdaeng, P. Prom-ngarm, N. Panyoyai
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Biochar has been used as a soil amendment since it has high porous structure and has proper nutrients and chemical properties for plants. Product yields produced from biochar kiln are dependent on process parameters and kiln types used. The objective of this research is to investigate the effect of core puncture diameter on biochar kiln efficiency, i.e., yields of biochar and produced gas. Corncobs were used as raw material to produce biochar. Briquettes from agricultural wastes were used as fuel. Each treatment was performed by changing the core puncture diameter. From the experiment, it is revealed that the yield of biochar at the core puncture diameter of 3.18 mm, 4.76 mm, and 6.35 mm was 10.62 wt. %, 24.12 wt. %, and 12.24 wt. %, of total solid yields, respectively. The yield of produced gas increased with increasing the core puncture diameter. The maximum percentage by weight of the yield of produced gas was 81.53 wt. % which was found at the core puncture diameter of 6.35 mm. The core puncture diameter was furthermore found to affect the temperature distribution inside the kiln and its thermal efficiency. In conclusion, the high efficient biochar kiln can be designed and constructed by using the proper core puncture diameter.Keywords: anila stove, bio-char, soil conditioning materials, temperature distribution
Procedia PDF Downloads 22212448 An Integrated Approach to Find the Effect of Strain Rate on Ultimate Tensile Strength of Randomly Oriented Short Glass Fiber Composite in Combination with Artificial Neural Network
Authors: Sharad Shrivastava, Arun Jalan
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In this study tensile testing was performed on randomly oriented short glass fiber/epoxy resin composite specimens which were prepared using hand lay-up method. Samples were tested over a wide range of strain rate/loading rate from 2mm/min to 40mm/min to see the effect on ultimate tensile strength of the composite. A multi layered 'back propagation artificial neural network of supervised learning type' was used to analyze and predict the tensile properties with strain rate and temperature as given input and output as UTS to predict. Various network structures were designed and investigated with varying parameters and network sizes, and an optimized network structure was proposed to predict the UTS of short glass fiber/epoxy resin composite specimens with reasonably good accuracy.Keywords: glass fiber composite, mechanical properties, strain rate, artificial neural network
Procedia PDF Downloads 43612447 Effect of Variety and Fibre Type on Functional and organoleptic Properties of Plantain Flour Intended for Food "Fufu"
Authors: C. C. Okafor
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The effect of different varieties of plantain (Horn, false horn and French) and fibre types (soy bean residue, cassava sievette and rice bran) on functional and organoleptic properties of plantain-based flour was assessed. Horn, false horn french were processed by washing, peeling with knife, slicing into 3mm thickness and steam blanched at 80℃ for 5minutes, oven dried at 65℃ for 48 hours and milled into flours with attrition mill, sieved with 60 mesh sieve, separately. Fibre sources were processed, milled and fractionated into 60, 40 & 20 mesh sizes. Both flours were blended as 80:20, 70:30 and 60:40. Results obtained indicated that water absorption capacity is highest (2.68) in French plantain variety irrespective of the fibre type used. And in all variety tested the swelling capacity is highest (2.93) when the plantain flour is blended with soy residue (SR) and lowest (1.25) when blended with rice brain (RB). The results show that there is significant variety and fibre type interaction effect at (P < : 0.05). Again the results showed that texture mold ability and overall acceptability were best (7.00) when soy residue was used where as addition of rice bran into plantain flour resulted in fufu with poor texture. This trend was observed in all the verities of plantain tested and in all of the particle size of flour. Using cassava serviette also yield fufu similar to that produced with soy residue in all the parameter tested (mold ability, texture and overall acceptability. Generally, plantain flours from french and false horn yielded better quality fufu in terms of texture mold ability, overall acceptability, irrespective of the fibre type used.Keywords: functional, organoleptic, particle size, sieve mesh, variety
Procedia PDF Downloads 40112446 Hepatoxicity induced Glyphosate-Based Herbicide Baron in albino rats
Authors: Manal E. A Elhalwagy, Nadia Amin Abdulmajeed, Hanan S. Alnahdi, Enas N. Danial
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Baron is herbicide includes (48% glyphosate) widely used in Egypt. The present study assesses the cytotoxic and genotoxic effect of baron on rats liver. Two groups of rats were treated orally with 1/10 LD 50, (275.49 mg kg -1) and 1/40 LD 50, (68.86 mg kg-1) glyphosate for 28 days compared with control group. Serum and liver tissues were taken at 14 and 28 days of treatment. An inhibition in Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities were recorded at both treatment periods and reduction in total serum protein (TP) and albumin (ALB). However, non-significant changes in serum acetylcholinesterase (AChE). Elevation in oxidative stress biomarker malondyaldehyde (MDA) and the decline in detoxification biomarker total reduced glutathione (GSH), Glutathione S-transferase (GST) and superoxide dismutase (SOD) in liver tissues led to increase in percentage of DNA damage. Destruction in liver tissue architecture was observed . Although, Baron was classified in the safe category pesticides repeated exposure to small doses has great danger effect.Keywords: glyphosate, liver toxicity, oxidative stress, DNA damage, commet assay
Procedia PDF Downloads 37212445 Microwave-Assisted 3D Porous Graphene for Its Multi-Functionalities
Authors: Jung-Hwan Oh, Rajesh Kumar, Il-Kwon Oh
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Porous graphene has extensive potential applications in variety of fields such as hydrogen storage, CO oxidation, gas separation, supercapacitors, fuel cells, nanoelectronics, oil adsorption, and so on. However, the generation of some carbon atoms vacancies for precise small holes have been not extensively studied to prevent the agglomerates of graphene sheets and to obtain porous graphene with high surface area. Recently, many research efforts have been presented to develop physical and chemical synthetic approaches for porous graphene. But physical method has very high cost of manufacture and chemical method consumes so many hours for porous graphene. Herein, we propose a porous graphene contained holes with atomic scale precision by embedding metal nano-particles through microwave irradiation for hydrogen storage and CO oxidation multi- functionalities. This proposed synthetic method is appropriate for fast and convenient production of three dimensional nanostructures, which have nanoholes on the graphene surface in consequence of microwave irradiation. The metal nanoparticles are dispersed quickly on the graphene surface and generated uniform nanoholes on the graphene nanosheets. The morphological and structural characterization of the porous graphene were examined by scanning electron microscopy (SEM), transmission scanning electron microscopy (TEM) and RAMAN spectroscopy, respectively. The metal nanoparticle-embedded porous graphene exhibits a microporous volume of 2.586cm3g-1 with an average pore radius of 0.75 nm. HR-TEM analysis was carried out to further characterize the microstructures. By investigating the RAMAN spectra, we can understand the structural changes of graphene. The results of this work demonstrate a possibility to produce a new class of porous graphene. Furthermore, the newly acquired knowledge for the diffusion into graphene can provide useful guidance for the development of the growth of nanostructure.Keywords: CO oxidation, hydrogen storage, nanocomposites, porous graphene
Procedia PDF Downloads 36812444 Analysing the Moderating Effect of Customer Loyalty on Long Run Repurchase Intentions
Authors: John Akpesiri Olotewo
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One of the controversies in existing marketing literatures is on how to retain existing and new customers to have repurchase intention in the long-run; however, empirical answer to this question is scanty in existing studies. Thus, this study investigates the moderating effect of consumer loyalty on long-run repurchase intentions in telecommunication industry using Lagos State environs. The study adopted field survey research design using questionnaire to elicit responses from 250 respondents who were selected using random and stratified random sampling techniques from the telecommunication industry in Lagos State, Nigeria. The internal consistency of the research instrument was verified using the Cronbach’s alpha, the result of 0.89 implies the acceptability of the internal consistency of the survey instrument. The test of the research hypotheses were analyzed using Pearson Product Method of Correlation (PPMC), simple regression analysis and inferential statistics with the aid of Statistical Package for Social Science version 20.0 (SPSS). The study confirmed that customer satisfaction has a significant relationship with customer loyalty in the telecommunication industry; also Service quality has a significant relationship with customer loyalty to a brand; loyalty programs have a significant relationship with customer loyalty to a network operator in Nigeria and Customer loyalty has a significant effect on the long run repurchase intentions of the customer. The study concluded that one of the determinants of long term profitability of a business entity is the long run repurchase intentions of its customers which hinges on the level of brand loyalty of the customer. Thus, it was recommended that service providers in Nigeria should improve on factors like customer satisfaction, service quality, and loyalty programs in order to increase the loyalty of their customer to their brands thereby increasing their repurchase intentions.Keywords: customer loyalty, long run repurchase intentions, brands, service quality and customer satisfaction
Procedia PDF Downloads 22912443 Mixed Hydrotropic Zaleplon Oral Tablets: Formulation and Neuropharmacological Effect on Plasma GABA Level
Authors: Ghada A. Abdelbary, Maha M. Amin, Mostafa Abdelmoteleb
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Zaleplon (ZP) is a non-benzodiazepine poorly soluble hypnotic drug indicated for the short term treatment of insomnia having a bioavailability of about 30%. The aim of the present study is to enhance the solubility and consequently the bioavailability of ZP using hydrotropic agents (HA). Phase solubility diagrams of ZP in presence of different molar concentrations of HA (Sodium benzoate, Urea, Ascorbic acid, Resorcinol, Nicotinamide, and Piperazine) were constructed. ZP/Sodium benzoate and Resorcinol microparticles were prepared adopting melt, solvent evaporation and melt-evaporation techniques followed by XRD. Directly compressed mixed hydrotropic ZP tablets of Sodium benzoate and Resorcinol in different weight ratios were prepared and evaluated compared to the commercially available tablets (Sleep aid® 5 mg). The effect of shelf and accelerated stability storage (40°C ± 2°C/75%RH ± 5%RH) on the optimum tablet formula (F5) for six months were studied. The enhancement of ZP solubility follows the order of: Resorcinol > Sodium benzoate > Ascorbic acid > Piperazine > Urea > Nicotinamide with about 350 and 2000 fold increase using 1M of Sodium benzoate and Resorcinol respectively. ZP/HA microparticles exhibit the order of: Solvent evaporation > melt-solvent evaporation > melt > physical mixture which was further confirmed by the complete conversion of ZP into amorphous form. Mixed hydrotropic tablet formula (F5) composed of ZP/(Resorcinol: Sodium benzoate 4:1w/w) microparticles prepared by solvent evaporation exhibits in-vitro dissolution of 31.7±0.11% after five minutes (Q5min) compared to 10.0±0.10% for Sleep aid® (5 mg) respectively. F5 showed significantly higher GABA concentration of 122.5±5.5mg/mL in plasma compared to 118±1.00 and 27.8±1.5 mg/mL in case of Sleep aid® (5 mg) and control taking only saline respectively suggesting a higher neuropharmacological effect of ZP following hydrotropic solubilization.Keywords: zaleplon, hydrotropic solubilization, plasma GABA level, mixed hydrotropy
Procedia PDF Downloads 43812442 Response to Comprehensive Stress of Growing Greylag Geese Offered Alternative Fiber Sources
Authors: He Li Wen, Meng Qing Xiang, Li De Yong, Zhang Ya Wei, Ren Li Ping
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Stress always exerts some extent adverse effects on the animal production, food safety and quality concerns. Stress is commonly-seen in livestock industry, but there is rare literature focusing on the effects of nutrition stress. What’s more, the research always concentrates on the effect of single stress additionally, there is scarce information about the stress effect on waterfowl like goose as they are commonly thought to be tolerant to stress. To our knowledge, it is not always true. The object of this study was to evaluate the response of growing Greylag geese offered different fiber sources to the comprehensive stress, primarily involving the procedures of fasting, transport, capture, etc. The birds were randomly selected to rear with the diets differing in fiber source, being corn straw silage (CSS), steam-exploded corn straw (SECS), steam-exploded wheat straw (SEWS), and steam-exploded rice straw (SERS), respectively. Blood samples designated for the determination of stress status were collected before (pre-stress ) and after (post-stress ) the stressors carried out. No difference (P>0.05) was found on the pre-stress blood parameters of growing Greylags fed alternative fiber sources. Irrespective of the dietary differences, the comprehensive stress decreased (P<0.01) the concentration of SOD and increased (P<0.01) that of CK. Between the dietary treatments, the birds fed CSS had a higher (P<0.05)post-stress concentration of MDA than those offered SECS, along with a similarity to those fed the other two fiber sources. There was no difference (P>0.05) found on the stress response of the birds fed different fiber sources. In conclusion, SOD and CK concentration in blood may be more sensitive in indicating stress status and dietary fiber source exerted no effect on the stress response of growing Greylags. There is little chance to improve the stress status by ingesting different fiber sources.Keywords: blood parameter, fiber source, Greylag goose, stress
Procedia PDF Downloads 51012441 Synthesis of Pd@ Cu Core−Shell Nanowires by Galvanic Displacement of Cu by Pd²⁺ Ions as a Modified Glassy Carbon Electrode for the Simultaneous Determination of Dihydroxybenzene Isomers Speciation
Authors: Majid Farsadrouh Rashti, Parisa Jahani, Amir Shafiee, Mehrdad Mofidi
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The dihydroxybenzene isomers, hydroquinone (HQ), catechol (CC) and resorcinol (RS) have been widely recognized as important environmental pollutants due to their toxicity and low degradability in the ecological environment. Speciation of HQ, CC and RS is very important for environmental analysis because they co-exist of these isomers in environmental samples and are too difficult to degrade as an environmental contaminant with high toxicity. There are many analytical methods have been reported for detecting these isomers, such as spectrophotometry, fluorescence, High-performance liquid chromatography (HPLC) and electrochemical methods. These methods have attractive advantages such as simple and fast response, low maintenance costs, wide linear analysis range, high efficiency, excellent selectivity and high sensitivity. A novel modified glassy carbon electrode (GCE) with Pd@ Cu/CNTs core−shell nanowires for the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RS) is described. A detailed investigation by field emission scanning electron microscopy and electrochemistry was performed in order to elucidate the preparation process and properties of the GCE/ Pd/CuNWs-CNTs. The electrochemical response characteristic of the modified GPE/LFOR toward HQ, CC and RS were investigated by cyclic voltammetry, differential pulse voltammetry (DPV) and Chronoamperometry. Under optimum conditions, the calibrations curves were linear up to 228 µM for each with detection limits of 0.4, 0.6 and 0.8 µM for HQ, CC and RS, respectively. The diffusion coefficient for the oxidation of HQ, CC and RS at the modified electrode was calculated as 6.5×10⁻⁵, 1.6 ×10⁻⁵ and 8.5 ×10⁻⁵ cm² s⁻¹, respectively. DPV was used for the simultaneous determination of HQ, CC and RS at the modified electrode and the relative standard deviations were 2.1%, 1.9% and 1.7% for HQ, CC and RS, respectively. Moreover, GCE/Pd/CuNWs-CNTs was successfully used for determination of HQ, CC and RS in real samples.Keywords: dihydroxybenzene isomers, galvanized copper nanowires, electrochemical sensor, Palladium, speciation
Procedia PDF Downloads 12412440 Effect of Pretreatment and Drying Method on Selected Quality Parameters of Dried Bell Pepper
Authors: Toyosi Yewande Tunde-Akintunde, Grace Oluwatoyin Ogunlakin, Bosede Folake Olanipekun
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Peppers are excellent sources of nutrients but its high moisture content makes it susceptible to spoilage. Drying, a common processing method, results in a reduction of these nutrients in the final product. Pre-treatment of pepper before drying can be used to reduce the level of degradation of nutrients. Thus this study investigated the effect of pre-treatment (hot water blanching and soaking in brine-sodium chloride) and drying methods (oven, microwave and sun) on selected quality parameters (proximate composition, capsaicin, reducing sugar and phenolic content, pH, total solid (TS), Titratable acidity (TA), water absorption capacity (WAC) and colour) of pepper. The protein and moisture content value ranged from 9.09 to 10.23% and 5.63 to 8.48% respectively. Sun dried samples had the highest value while oven dried samples had the lowest. Brine treated samples had higher protein but lower moisture content than blanched samples. Capsaicin, reducing sugar and phenolic content values ranged from 0.68 to 0.87 mg/dm3; 3.18 to 3.79 µg/ml; and 40.67 to 84.01 mg GAE/100 g d.m respectively. The sun dried samples had higher values while the lowest values were from microwave dried samples. The brine treated samples had higher values in capsaicin while the blanched samples had higher reducing sugar and phenolic contents. The values of L, a* and b* for the dried pepper varied from 58.76 to 63.13; 7.09 to 7.34; and 11.79 to 12.36 respectively. Oven dried samples had the lowest values for a*, while its L values were the highest. The L and a* values for brine treated samples were higher than blanched samples. The pre-treatment and drying method considered resulted in different values of the quality parameters considered which indicates that drying and pre-treatment has an effect on the quality of the final dried pepper samples.Keywords: Bell pepper, microwave drying, oven drying, quality, sun drying
Procedia PDF Downloads 33812439 Investigations into Effect of Neural Network Predictive Control of UPFC for Improving Transient Stability Performance of Multimachine Power System
Authors: Sheela Tiwari, R. Naresh, R. Jha
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The paper presents an investigation into the effect of neural network predictive control of UPFC on the transient stability performance of a multi-machine power system. The proposed controller consists of a neural network model of the test system. This model is used to predict the future control inputs using the damped Gauss-Newton method which employs ‘backtracking’ as the line search method for step selection. The benchmark 2 area, 4 machine system that mimics the behavior of large power systems is taken as the test system for the study and is subjected to three phase short circuit faults at different locations over a wide range of operating conditions. The simulation results clearly establish the robustness of the proposed controller to the fault location, an increase in the critical clearing time for the circuit breakers and an improved damping of the power oscillations as compared to the conventional PI controller.Keywords: identification, neural networks, predictive control, transient stability, UPFC
Procedia PDF Downloads 36512438 Comparative Study between Herzberg’s and Maslow’s Theories in Maritime Transport Education
Authors: Nermin Mahmoud Gohar, Aisha Tarek Noour
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Learner satisfaction has been a vital field of interest in the literature. Accordingly, the paper will explore the reasons behind individual differences in motivation and satisfaction. This study examines the effect of both; Herzberg’s and Maslow’s theories on learners satisfaction. A self-administered questionnaire was used to collect data from learners who were geographically widely spread around the College of Maritime Transport and Technology (CMTT) at the Arab Academy for Science, Technology and Maritime Transport (AAST&MT) in Egypt. One hundred and fifty undergraduates responded to a questionnaire survey. Respondents were drawn from two branches in Alexandria and Port Said. The data analysis used was SPSS 22 and AMOS 18. Factor analysis technique was used to find out the dimensions under study verified by Herzberg’s and Maslow’s theories. In addition, regression analysis and structural equation modeling were applied to find the effect of the above-mentioned theories on maritime transport learners’ satisfaction. Concerning the limitation of this study, it used the available number of learners in the CMTT due to the relatively low population in this field.Keywords: motivation, satisfaction, needs, education, Herzberg’s and Maslow’s theories
Procedia PDF Downloads 42712437 Addictive Use Due to Personality: Focused on Big Five Personality Traits and Game Addiction
Authors: Eui Jun Jeong, Hye Rim Lee, Ji Hye Yoo
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Recent studies have verified the significant relationship of user personality with Internet use. However, in game studies, little research has emphasized on the effects of personality traits on game addiction. This study examined whether big five personality traits affect game addiction with control of psychological, social, and demographic factors. Specifically, using data from a survey of 789 game users in Korea, we conducted a regression analysis to see the associations of psychological (loneliness/depression), social (activities with family/friends), self-efficacy (game/general), gaming (daily gaming time/perception), demographic (age/gender), and personality traits (extraversion, neuroticism conscientiousness, agreeableness, & openness) with the degree of game addiction. Results showed that neuroticism increase game addiction with no effect of extraversion on the addiction. General self-efficacy negatively affected game addiction, whereas game self-efficacy increased the degree of game addiction. Loneliness enhanced game addiction while depression showed a negative effect on the addiction. Results and implications are discussed.Keywords: game addiction, big five personality, social activities, self-efficacy, loneliness, depression
Procedia PDF Downloads 56212436 A Seismic Study on The Settlement of Superstructures Due to the Tunnel Construction
Authors: Seyed Abolhasan Naeini, Saeideh Mohammadi
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Rapid urban development leads to the construction of urban tunnels for transport. Passage of tunnels under the surface structures and utilities prompted the changes in the site conditions and hence alteration of the dynamic response of surface structures. Therefore, in this study, the effect of the interaction of tunnel-superstructure on the site response is investigated numerically. For this purpose, Fast Lagrangian Analysis of Continua (FLAC 2D) is used, and stratification and properties of soil layers are selected based on the line No 7 of Tehran subway. The superstructure is modeled both as an equivalent surcharge and the actual structure, and the results are compared. A comparison of the results shows that consideration of structure geometry is necessary for dynamic analysis and it leads to the changes in displacements and accelerations. Consequently, the geometry of the superstructure should be modeled completely instead of the application of an equivalent load. The effect of tunnel diameter and depth on the settlement of superstructures is also studied. Results show that when the tunnel depth and diameter grow, the settlements increase considerably.Keywords: tunnel, FLAC2D, settlement, dynamic analysis
Procedia PDF Downloads 12512435 The Effects of the Uniaxial Anisotropy and the Loss Tangent on the Resonant Frequencies in Stacked Rectangular Patches Configuration
Authors: Boualem Mekimah, Abderraouf Messai, Abdelkrim Belhedri
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Dielectric substrates have an important attention in the fabrication of microstrip patch antennas. The effects of the uniaxial anisotropy and the loss tangent on resonant frequencies of microstrip patches consist of two perfectly conducting rectangular patches in stacked and offset configuration, embedded in a bilayer medium containing isotropic or uniaxial anisotropic materials. The Green’s functions are discussed in detail and numerical results are validated by comparing the computed results with previously published data. The numerical results show, that the uniaxial anisotropy has more effects on resonant frequencies according to the optical axis. However, the loss tangent of dielectric substrates has almost no effect on resonant frequencies, but it strongly affects the imaginary parts of the resonant frequencies of the antenna. The dielectric constant has no effect on the separation in terms of frequencies.Keywords: resonant frequencies, loss tangent, microstrip patches, stacked, anisotropic materials, optical axis
Procedia PDF Downloads 42912434 The Effectiveness of Extracorporeal Shockwave Therapy on Pain and Motor Function in Subjects with Knee Osteoarthritis A Systematic Review and Meta-Analysis of Randomized Clinical Trial
Authors: Vu Hoang Thu Huong
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Background and Purpose: The effects of Extracorporeal Shockwave Therapy (ESWT) in the participants with knee osteoarthritis (KOA) were unclear on physical performance although its effects on pain had been investiagted. This study aims to explore the effects of ESWT on pain relief and physical performance on KOA. Methods: The studies with the randomized controlled design to investigate the effects of ESWT on KOA were systematically searched using inclusion and exclusion criteria through seven electronic databases including Pubmed etc. between 1990 and Dec 2022. To summarize those data, visual analog scale (VAS) or pain scores were determined for measure of pain intensity. Range of knee motion, or the scores of physical activities including Lequesne index (LI), Knee Injury and Osteoarthritis Outcome Score (KOOS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were determined for measure of physical performances. The first evaluate after treatment period was define as the effect of post-treatment period or immediately effect; and the last evaluate was defined as the effect of following period or the end effect in our study. Data analysis was performed using RevMan 5.4.1 software. A significant level was set at p<0.05. Results: Eight studies (number of participant= 499) reporting the ESWT effects on mild-to-moderate severity (Grades I to III Kellgren–Lawrence) of KOA were qualified for meta-analysis. Compared with sham or placebo group, the ESWT group had a significant decrease of VAS rest score (0.90[0.12~1.67] as mean difference [95% confidence interval]) and pain score WOMAC (2.49[1.22~3.76]), and a significant improvement of physical performance with a decrease of the scores of WOMAC activities (8.18[3.97~12.39]), LI (3.47[1.68~5.26]), and KOOS (5.87[1.73~ 10.00]) in the post-treatment period. There were also a significant decrease of WOMAC pain score (2.83[2.12~3.53]) and a significant decrease of the scores of WOMAC activities (9.47[7.65~11.28]) and LI (4.12[2.34 to 5.89]) in the following period. Besides, compared with other treatment groups, ESWT also displayed the improvement in pain and physical performance, but it is not significant. Conclusions: The ESWT was effective and valuable method in pain relief as well as in improving physical activities in the participants with mild-to-moderate KOA. Clinical Relevance: There are the effects of ESWT on pain relief and the improvement of physical performance in the with KOA.Keywords: knee osteoarthritis, extracorporeal shockwave therapy, pain relief, physical performance, shockwave
Procedia PDF Downloads 7912433 Translational and Rotational Effect of Earthquake Ground Motion on a Bridge Substructure
Authors: Tauhidur Rahman, Gitartha Kalita
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In this study a four span box girder bridge is considered and effect of the rotational and translational earthquake ground motion have been thoroughly investigated. This study is motivated by the fact that in many countries the translational and rotational components of earthquake ground motion, especially rocking, is not adequately considered in analysing the overall response of the structures subjected to earthquake ground excitations. Much consideration is given to only the horizontal components of the earthquake ground motion during the response analysis of structures. In the present research work, P waves, SV waves and Rayleigh wave excitations are considered for different angle of incidence. In the present paper, the four span bridge is model considering the effects of vertical and rocking components of P, SV and Rayleigh wave excitations. Ground responses namely displacement, velocity and acceleration of the substructures of the bridge have been considered for rotational and translational effects in addition to the horizontal ground motion due to earthquake and wind.Keywords: ground motion, response, rotational effects, translational effects
Procedia PDF Downloads 43412432 Analysis of Interparticle interactions in High Waxy-Heavy Clay Fine Sands for Sand Control Optimization
Authors: Gerald Gwamba
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Formation and oil well sand production is one of the greatest and oldest concerns for the Oil and gas industry. The production of sand particles may vary from very small and limited amounts to far elevated levels which has the potential to block or plug the pore spaces near the perforated points to blocking production from surface facilities. Therefore, the timely and reliable investigation of conditions leading to the onset or quantifying sanding while producing is imperative. The challenges of sand production are even more elevated while producing in Waxy and Heavy wells with Clay Fine sands (WHFC). Existing research argues that both waxy and heavy hydrocarbons exhibit far differing characteristics with waxy more paraffinic while heavy crude oils exhibit more asphaltenic properties. Moreover, the combined effect of WHFC conditions presents more complexity in production as opposed to individual effects that could be attributed to a consolidation of a surmountable opposing force. However, research on a combined high WHFC system could depict a better representation of the surmountable effect which in essence is more comparable to field conditions where a one-sided view of either individual effects on sanding has been argued to some extent misrepresentative of actual field conditions since all factors act surmountably. In recognition of the limited customized research on sand production studies with the combined effect of WHFC however, our research seeks to apply the Design of Experiments (DOE) methodology based on latest literature to analyze the relationship between various interparticle factors in relation to selected sand control methods. Our research aims to unearth a better understanding of how the combined effect of interparticle factors including: strength, cementation, particle size and production rate among others could better assist in the design of an optimal sand control system for the WHFC well conditions. In this regard, we seek to answer the following research question: How does the combined effect of interparticle factors affect the optimization of sand control systems for WHFC wells? Results from experimental data collection will inform a better justification for a sand control design for WHFC. In doing so, we hope to contribute to earlier contrasts arguing that sand production could potentially enable well self-permeability enhancement caused by the establishment of new flow channels created by loosening and detachment of sand grains. We hope that our research will contribute to future sand control designs capable of adapting to flexible production adjustments in controlled sand management. This paper presents results which are part of an ongoing research towards the authors' PhD project in the optimization of sand control systems for WHFC wells.Keywords: waxy-heavy oils, clay-fine sands, sand control optimization, interparticle factors, design of experiments
Procedia PDF Downloads 12812431 Surface Roughness Modeling in Dry Face Milling of Annealed and Hardened AISI 52100 Steel
Authors: Mohieddine Benghersallah, Mohamed Zakaria Zahaf, Ali Medjber, Idriss Tibakh
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The objective of this study is to analyse the effects of cutting parameters on surface roughness in dry face milling using statistical techniques. We studied the effect of the microstructure of AISI 52100 steel on machinability before and after hardening. The machining tests were carried out on a high rigidity vertical milling machine with a 25 mm diameter face milling cutter equipped with micro-grain bicarbide inserts with PVD (Ti, AlN) coating in GC1030 grade. A Taguchi L9 experiment plan is adopted. Analysis of variance (ANOVA) was used to determine the effects of cutting parameters (Vc, fz, ap) on the roughness (Ra) of the machined surface. Regression analysis to assess the machinability of steel presented mathematical models of roughness and the combination of parameters to minimize it. The recorded results show that feed per tooth has the most significant effect on the surface condition for both steel treatment conditions. The best roughnesses were obtained for the hardened AISI 52100 steel.Keywords: machinability, heat treatment, microstructure, surface roughness, Taguchi method
Procedia PDF Downloads 14312430 Fluid Structure Interaction of Flow and Heat Transfer around a Microcantilever
Authors: Khalil Khanafer
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This study emphasizes on analyzing the effect of flow conditions and the geometric variation of the microcantilever’s bluff body on the microcantilever detection capabilities within a fluidic device using a finite element fluid-structure interaction model. Such parameters include inlet velocity, flow direction, and height of the microcantilever’s supporting system within the fluidic cell. The transport equations are solved using a finite element formulation based on the Galerkin method of weighted residuals. For a flexible microcantilever, a fully coupled fluid-structure interaction (FSI) analysis is utilized and the fluid domain is described by an Arbitrary-Lagrangian–Eulerian (ALE) formulation that is fully coupled to the structure domain. The results of this study showed a profound effect on the magnitude and direction of the inlet velocity and the height of the bluff body on the deflection of the microcantilever. The vibration characteristics were also investigated in this study. This work paves the road for researchers to design efficient microcantilevers that display least errors in the measurements.Keywords: fluidic cell, FSI, microcantilever, flow direction
Procedia PDF Downloads 37112429 Effect of Multilayered MnBi Films on Magnetic and Microstructural Properties
Authors: Hyun-Sook Lee, Hongjae Moon, Hwaebong Jung, Sumin Kim, Wooyoung Lee
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Low-temperature phase (LTP) of MnBi has attracted much attention because it has a larger coercivity than that of Nd-Fe-B at high temperature, which gives high potential as a permanent magnet material that can be used at such high temperature. We present variation in magnetic properties of MnBi films by controlling the numbers of Bi/Mn bilayer. The thin films of LTP-MnBi were fabricated onto glass substrates by UHV sputtering, followed by in-situ annealing process at an optimized condition of 350 °C and 1.5 hours. The composition ratio of Bi/Mn was adjusted by varying the thickness of Bi and Mn layers. The highest value of (BH)max ~ 8.6 MGOe at room temperature was obtained in one Bi/Mn bilayer with 34 nm Bi and 16 nm Mn. To investigate the effect of Bi/Mn multilayers on the magnetic properties, we increased the numbers of Bi/Mn bilayer up to five at which the total film thicknesses of Bi and Mn were fixed with 34 nm and 16 nm. The increase of coercivity was observed up to three layers from 4.8 kOe to 15.3 kOe and then suppression was appeared. A reversed behavior was exhibited in the magnetization. We found that these were closely related to a microstructural change of LTP-MnBi and a reduction of growth rate of LTP-MnBi by analyzing XRD and TEM results. We will discuss how the multilayered MnBi affects the magnetic properties in details.Keywords: coercivity, MnBi, multilayer film, permanent magnet
Procedia PDF Downloads 32812428 The Effect of Video Games on English as a Foreign Language Students' Language Learning Motivation
Authors: Shamim Ali
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Researchers and teachers have begun developing digital games and model environments for educational purpose; therefore this study examines the effect of a videos game on secondary school students’ language learning motivation. Secondly, it tries to find out the opportunities to develop a decision making process and simultaneously it analyzes the solutions for further implementation in educational setting. Participants were 30 male students randomly assigned to one of the following three treatments: 10 students were assigned to read the game’s story; 10 students were players, who played video game; and, and the last 10 students acted as watchers and observers, their duty was to watch their classmates play the digital video game. A language learning motivation scale was developed and it was given to the participants as a pre- and post-test. Results indicated a significant language learning motivation and the participants were quite motivated in the end. It is, thus, concluded that the use of video games can help enhance high school students’ language learning motivation. It was suggested that video games should be used as a complementary activity not as a replacement for textbook since excessive use of video games can divert the original purpose of learning.Keywords: EFL, English as a Foreign Language, motivation, video games, EFL learners
Procedia PDF Downloads 17012427 Effect of Pre-Treatment with Salicylic Acid on Vegetative Growth and Yield Components of Saudi’s Wheat under Salinity
Authors: Saad Howladar, Mike Dennett
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At first harvest, results showed that salinity (tap water, 100 and 200 mM NaCl) induced a significant decrease in all growth parameters in both Yecora Rojo and Paragon cultivars. The greatest effect of salinity was a decrease in leaf area. The same tendency was observed with specific leaf area, and total fresh and dry weights and their components. Green leaf and tiller numbers were reduced by the same extent in both cultivars. The corresponding final harvest, all growth parameters also reduced with increased salinity. Yield and yield components were also reduced by salinity with similar effects in both cultivars. Chlorophyll fluorescence, expressed as Fv/Fm, and gas exchange parameters were decreased significantly with increase in salinity in both cultivars. In contrast, seed protein content was increased significantly with increase in salinity. Salicylic acid (SA) application induced no significant improvements in growth parameters and yield components.Keywords: salinity, salicylic acid, growth, chlorophyll fluorescence, gas exchange, yield
Procedia PDF Downloads 41612426 The Effect of Gibberellic Acid on Gamma-Aminobutyric Acid (GABA) Metabolism in Phaseolus Vulgaris L. Plant Exposed to Drought and Salt Stresses
Authors: Fazilet Özlem Çekiç, Seyda Yılmaz
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Salinity and drought are important environmental problems in the world and have negative effects on plant metabolism. Gamma-aminobutyric acid (GABA), four-carbon non-protein amino acid, is a significant component of the free amino acid pool. GABA is widely distributed in prokaryotic and eukaryotic organisms. Environmental stress factors increase GABA accumulation in plants. Our aim was to evaluate the effect of gibberellic acid (GA) on GABA metabolism system during drought and salt stress factors in Phaseolus vulgaris L. plants. GABA, Glutamate dehydrogenase (GDH) activity, chlorophyll, and lipid peroxidation (MDA) analyses were determined. According to our results we can suggest that GA play a role in GABA metabolism during salt and drought stresses in bean plants. Also GABA shunt is an important metabolic pathway and key signaling allowing to adapt to drought and salt stresses.Keywords: gibberellic acid, GABA, Phaseolus vulgaris L., salinity, drought
Procedia PDF Downloads 41612425 Temperature Control and Comfort Level of Elementary School Building with Green Roof in New Taipei City, Taiwan
Authors: Ying-Ming Su, Mei-Shu Huang
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To mitigate the urban heat island effect has become a global issue facing the challenge of climate change. Through literature reviews, plant photosynthesis can reduce the carbon dioxide and mitigate the urban heat island effect relatively. Because there are not enough open space and park, green roof has become an important policy in Taiwan. We selected elementary school buildings in northern New Taipei City as research subjects since elementary school is asked priority to build green roof and important educational place to promote green roof concept. Testo 175-H1 recording device was used to record the temperature and humidity difference between roof surface and interior space below roof with and without green roof for the long-term. We also use questionnaire to investigate the awareness of comfort level of green roof and sensation of teachers and students of the elementary school. The results indicated the temperature of roof without greening was higher than that with greening about 2°C. But sometimes during noontime, the temperature of green roof was higher than that of non-green roof related to the character of the accumulation and dissipation of heat of greening probably. The temperature of interior space below green roof was normally lower than that without green roof about 1°C showed that green roof could lower the temperature. The humidity of the green roof was higher than the one without greening also indicated that green roof retained water better. Teachers liked to combine green roof concept in the curriculum, students wished all classes can take turns to maintain the green roof. Teachers and students that school had integrated green roof concept in the curriculum were more willing to participate in the maintenance work of green roof. Teachers and students who may access and touch the green roof can be more aware of the green roof benefit. We suggest architect to increase the accessibility and visibility of green roof, such as a part of the activity space. This idea can be a reference of the green roof curriculum design.Keywords: comfort level, elementary school, green roof, heat island effect
Procedia PDF Downloads 41112424 Development of Risk-Based Dam Safety Framework in Climate Change Condition for Batu Dam, Malaysia
Authors: Wan Noorul Hafilah Binti Wan Ariffin
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Dam safety management is the crucial infrastructure as dam failure has a catastrophic effect on the community. Dam safety management is the effective framework of key actions and activities for the dam owner to manage the safety of the dam for its entire life cycle. However, maintaining dam safety is a challenging task as there are changes in current dam states. These changes introduce new risks to the dam's safety, which had not been considered when the dam was designed. A new framework has to be developed to adapt to the changes in the dam risk and make the dams resilient. This study proposes a risk-based decision-making adaptation framework for dam safety management. The research focuses on climate change's impact on hydrological situations as it causes floods and damages the dam structure. The risk analysis framework is adopted to improve the dam management strategies. The proposed study encompasses four phases. To start with, measuring the effect by assessing the impact of climate change on embankment dam, the second phase is to analyze the potential embankment dam failures. The third is analyzing the different components of risks related to the dam and, finally, developing a robust decision-making framework.Keywords: climate change, embankment dam, failure, risk-informed decision making
Procedia PDF Downloads 14512423 The Role of Brand Loyalty in Generating Positive Word of Mouth among Malaysian Hypermarket Customers
Authors: S. R. Nikhashemi, Laily Haj Paim, Ali Khatibi
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Structural Equation Modeling (SEM) was used to test a hypothesized model explaining Malaysian hypermarket customers’ perceptions of brand trust (BT), customer perceived value (CPV) and perceived service quality (PSQ) on building their brand loyalty (CBL) and generating positive word-of-mouth communication (WOM). Self-administered questionnaires were used to collect data from 374 Malaysian hypermarket customers from Mydin, Tesco, Aeon Big and Giant in Kuala Lumpur, a metropolitan city of Malaysia. The data strongly supported the model exhibiting that BT, CPV and PSQ are prerequisite factors in building customer brand loyalty, while PSQ has the strongest effect on prediction of customer brand loyalty compared to other factors. Besides, the present study suggests the effect of the aforementioned factors via customer brand loyalty strongly contributes to generate positive word of mouth communication.Keywords: brand trust, perceived value, Perceived Service Quality, Brand loyalty, positive word of mouth communication
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