Search results for: long term effect
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 20597

Search results for: long term effect

11507 Rice Bran Material Enrichment of Granulated Cane Brown Sugar to Increase Policosanol Contents

Authors: Monthana Weerawatanakorn, Hajime Tamaki, Yonathan Asikin, Koji Wada, Makoto Takahashi, Chi-Tang Ho, Min-Hsiung Pan

Abstract:

Rice bran and sugarcane are significant sources of wax containing policosanol (PC), the cholesterol-lowering nutraceutical available in the market. The processing of rice bran oil causes the loss of PC content into various waste products. Therefore, we hypothesise that defatted rice bran (DRB) as agricultural waste product and rice bran oil (RBO) retain a varying but significant amount of PC wax. Non-centrifugal cane sugar (NCS) or cane brown sugar has been consumed worldwide and possesses various health benefits. Since PC wax is mainly in the outer layer rinds of cane, PC contents of the granulated sugar are reduced due to the peeling step. The study aimed to increase PC contents of the granular brown sugar by adding wax extracted from DRB and RBO and to investigate the toxicity of the developed products. The results showed that the total PC contents including long chain aldehyde of products were increased to the maximum level of 147.97 mg/100 g and 40.14 mg/100 g for extracted wax and rice bran oil addition, respectively. PC content of RBO was found to be 96.93 mg/100 g. DRB is promising source of policosanol (6,044.7 mg/100 g). The 28-day toxicity evaluations of the developed sugar revealed no adverse effects on the liver, spleen or kidney.

Keywords: enrichment, sugarcane, policosanol, defatted rice bran, wax

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11506 Cellular Mechanisms Involved in the Radiosensitization of Breast- and Lung Cancer Cells by Agents Targeting Microtubule Dynamics

Authors: Elsie M. Nolte, Annie M. Joubert, Roy Lakier, Maryke Etsebeth, Jolene M. Helena, Marcel Verwey, Laurence Lafanechere, Anne E. Theron

Abstract:

Treatment regimens for breast- and lung cancers may include both radiation- and chemotherapy. Ideally, a pharmaceutical agent which selectively sensitizes cancer cells to gamma (γ)-radiation would allow administration of lower doses of each modality, yielding synergistic anti-cancer benefits and lower metastasis occurrence, in addition to decreasing the side-effect profiles. A range of 2-methoxyestradiol (2-ME) analogues, namely 2-ethyl-3-O-sulphamoyl-estra-1,3,5 (10) 15-tetraene-3-ol-17one (ESE-15-one), 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10),15-tetraen-17-ol (ESE-15-ol) and 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16) were in silico-designed by our laboratory, with the aim of improving the parent compound’s bioavailability in vivo. The main effect of these compounds is the disruption of microtubule dynamics with a resultant mitotic accumulation and induction of programmed cell death in various cancer cell lines. This in vitro study aimed to determine the cellular responses involved in the radiation sensitization effects of these analogues at low doses in breast- and lung cancer cell lines. The oestrogen receptor positive MCF-7-, oestrogen receptor negative MDA-MB-231- and triple negative BT-20 breast cancer cell lines as well as the A549 lung cancer cell line were used. The minimal compound- and radiation doses able to induce apoptosis were determined using annexin-V and cell cycle progression markers. These doses (cell line dependent) were used to pre-sensitize the cancer cells 24 hours prior to 6 gray (Gy) radiation. Experiments were conducted on samples exposed to the individual- as well as the combination treatment conditions in order to determine whether the combination treatment yielded an additive cell death response. Morphological studies included light-, fluorescence- and transmission electron microscopy. Apoptosis induction was determined by flow cytometry employing annexin V, cell cycle analysis, B-cell lymphoma 2 (Bcl-2) signalling, as well as reactive oxygen species (ROS) production. Clonogenic studies were performed by allowing colony formation for 10 days post radiation. Deoxyribonucleic acid (DNA) damage was quantified via γ-H2AX foci and micronuclei quantification. Amplification of the p53 signalling pathway was determined by western blot. Results indicated that exposing breast- and lung cancer cells to nanomolar concentrations of these analogues 24 hours prior to γ-radiation induced more cell death than the compound- and radiation treatments alone. Hypercondensed chromatin, decreased cell density, a damaged cytoskeleton and an increase in apoptotic body formation were observed in cells exposed to the combination treatment condition. An increased number of cells present in the sub-G1 phase as well as increased annexin-V staining, elevation of ROS formation and decreased Bcl-2 signalling confirmed the additive effect of the combination treatment. In addition, colony formation decreased significantly. p53 signalling pathways were significantly amplified in cells exposed to the analogues 24 hours prior to radiation, as was the amount of DNA damage. In conclusion, our results indicated that pre-treatment of breast- and lung cancer cells with low doses of 2-ME analogues sensitized breast- and lung cancer cells to γ-radiation and induced apoptosis more so than the individual treatments alone. Future studies will focus on the effect of the combination treatment on non-malignant cellular counterparts.

Keywords: cancer, microtubule dynamics, radiation therapy, radiosensitization

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11505 Multilevel Regression Model - Evaluate Relationship Between Early Years’ Activities of Daily Living and Alzheimer’s Disease Onset Accounting for Influence of Key Sociodemographic Factors Using a Longitudinal Household Survey Data

Authors: Linyi Fan, C.J. Schumaker

Abstract:

Background: Biomedical efforts to treat Alzheimer’s disease (AD) have typically produced mixed to poor results, while more lifestyle-focused treatments such as exercise may fare better than existing biomedical treatments. A few promising studies have indicated that activities of daily life (ADL) may be a useful way of predicting AD. However, the existing cross-sectional studies fail to show how functional-related issues such as ADL in early years predict AD and how social factors influence health either in addition to or in interaction with individual risk factors. This study would helpbetterscreening and early treatments for the elderly population and healthcare practice. The findings have significance academically and practically in terms of creating positive social change. Methodology: The purpose of this quantitative historical, correlational study was to examine the relationship between early years’ ADL and the development of AD in later years. The studyincluded 4,526participantsderived fromRAND HRS dataset. The Health and Retirement Study (HRS) is a longitudinal household survey data set that is available forresearchof retirement and health among the elderly in the United States. The sample was selected by the completion of survey questionnaire about AD and dementia. The variablethat indicates whether the participant has been diagnosed with AD was the dependent variable. The ADL indices and changes in ADL were the independent variables. A four-step multilevel regression model approach was utilized to address the research questions. Results: Amongst 4,526 patients who completed the AD and dementia questionnaire, 144 (3.1%) were diagnosed with AD. Of the 4,526 participants, 3,465 (76.6%) have high school and upper education degrees,4,074 (90.0%) were above poverty threshold. The model evaluatedthe effect of ADL and change in ADL on onset of AD in late years while allowing the intercept of the model to vary by level of education. The results suggested that the only significant predictor of the onset of AD was changes in early years’ ADL (b = 20.253, z = 2.761, p < .05). However, the result of the sensitivity analysis (b = 7.562, z = 1.900, p =.058), which included more control variables and increased the observation period of ADL, are not supported this finding. The model also estimated whether the variances of random effect vary by Level-2 variables. The results suggested that the variances associated with random slopes were approximately zero, suggesting that the relationship between early years’ ADL were not influenced bysociodemographic factors. Conclusion: The finding indicated that an increase in changes in ADL leads to an increase in the probability of onset AD in the future. However, this finding is not support in a broad observation period model. The study also failed to reject the hypothesis that the sociodemographic factors explained significant amounts of variance in random effect. Recommendations were then made for future research and practice based on these limitations and the significance of the findings.

Keywords: alzheimer’s disease, epidemiology, moderation, multilevel modeling

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11504 Least Squares Solution for Linear Quadratic Gaussian Problem with Stochastic Approximation Approach

Authors: Sie Long Kek, Wah June Leong, Kok Lay Teo

Abstract:

Linear quadratic Gaussian model is a standard mathematical model for the stochastic optimal control problem. The combination of the linear quadratic estimation and the linear quadratic regulator allows the state estimation and the optimal control policy to be designed separately. This is known as the separation principle. In this paper, an efficient computational method is proposed to solve the linear quadratic Gaussian problem. In our approach, the Hamiltonian function is defined, and the necessary conditions are derived. In addition to this, the output error is defined and the least-square optimization problem is introduced. By determining the first-order necessary condition, the gradient of the sum squares of output error is established. On this point of view, the stochastic approximation approach is employed such that the optimal control policy is updated. Within a given tolerance, the iteration procedure would be stopped and the optimal solution of the linear-quadratic Gaussian problem is obtained. For illustration, an example of the linear-quadratic Gaussian problem is studied. The result shows the efficiency of the approach proposed. In conclusion, the applicability of the approach proposed for solving the linear quadratic Gaussian problem is highly demonstrated.

Keywords: iteration procedure, least squares solution, linear quadratic Gaussian, output error, stochastic approximation

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11503 In Vitro Propagation of Aloe vera and Aloe littoralis Plants: Gamma Radiation, Biochemical and Genetic Changes

Authors: Z. Nourmohammadi, F. Farahani, M. Shaker

Abstract:

Aloe is an important commercial crop available in a wide range of species and varieties in international markets. The applications of this plant have been recorded in the ancient cultures of India, Egypt, Greece, Rome and China. Aloe has been used for centuries and is currently being actively studied for medicinal purposes. Aloe is propagated through lateral buds, which is slow, very expensive and low income practice. Nowadays, it has been cultured by in vitro propagation for rapid multiplication of plants, genetic improvement of crops, obtaining disease-free clones and for progressive valuable germplasm. The present study focused on the influence of different phytohormones on rapid in vitro propagation of Aloe plants. We also investigated the effect of gamma radiation on biochemical characters as well as genetic changes. Shoot tip of 2-3 cm were collected from offshoot of Aloe barbadensis and Aloe littoralis, and were inoculated with MS medium containing various concentrations of BA (0.5, 1, 2 mg/l), IAA (0.5, 1 mg/l). The best treatment for a highest shoot number and bud proliferation was MS medium containing 2 mg/l BAP and 0.5 mg/l IAA in A. barbadensis and A. littoralis. Maximum percentage of proliferated shoot buds (90% and 95%) from a single explant were obtained in MS medium after 4-5 weeks of the second and the first subcultures, respectively. Different genome sizes were also indicated among treatments and subcultures. The mixoploids identified in flow cytometery histograms in different treatments. The effect of gamma radiation on A. littoralis showed that by increasing the dose of gamma radiation, amounts of chlorophyll A, B, carotenoids, total protein content and superoxide dismutase were significantly increased compared to control plants. Genetic variation analysis also revealed significant genetic differences between control and gamma radiation treated regenerated plants by AMOVA test. Higher genetic heterozygocity was observed in radiation treated plants. Our findings may provide useful method for improving of Aloe plant proliferation with increasing of useful material such as antioxidant enzymes.

Keywords: aloe, antioxidant enzyme, micropropagation, gamma radiation, genetic variation

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11502 Fixed Point Iteration of a Damped and Unforced Duffing's Equation

Authors: Paschal A. Ochang, Emmanuel C. Oji

Abstract:

The Duffing’s Equation is a second order system that is very important because they are fundamental to the behaviour of higher order systems and they have applications in almost all fields of science and engineering. In the biological area, it is useful in plant stem dependence and natural frequency and model of the Brain Crash Analysis (BCA). In Engineering, it is useful in the study of Damping indoor construction and Traffic lights and to the meteorologist it is used in the prediction of weather conditions. However, most Problems in real life that occur are non-linear in nature and may not have analytical solutions except approximations or simulations, so trying to find an exact explicit solution may in general be complicated and sometimes impossible. Therefore we aim to find out if it is possible to obtain one analytical fixed point to the non-linear ordinary equation using fixed point analytical method. We started by exposing the scope of the Duffing’s equation and other related works on it. With a major focus on the fixed point and fixed point iterative scheme, we tried different iterative schemes on the Duffing’s Equation. We were able to identify that one can only see the fixed points to a Damped Duffing’s Equation and not to the Undamped Duffing’s Equation. This is because the cubic nonlinearity term is the determining factor to the Duffing’s Equation. We finally came to the results where we identified the stability of an equation that is damped, forced and second order in nature. Generally, in this research, we approximate the solution of Duffing’s Equation by converting it to a system of First and Second Order Ordinary Differential Equation and using Fixed Point Iterative approach. This approach shows that for different versions of Duffing’s Equations (damped), we find fixed points, therefore the order of computations and running time of applied software in all fields using the Duffing’s equation will be reduced.

Keywords: damping, Duffing's equation, fixed point analysis, second order differential, stability analysis

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11501 Shades of Memory, Echoes of Despair: Exploring Melancholy in Modern Amharic Novels

Authors: Dawit Dibekulu, Tesfaye Dagnew, Tesfamaryam G. Meskel

Abstract:

Echoing with memories of loss and whispers of despair, this study delves into the poignant world of melancholy in Sisay Nigusu's contemporary Amharic novel, ‘Yäqənat Zār’ (‘Zār of Jealousy’). Employing a psychoanalytic lens focused on Freud and Klein's theories of mourning and melancholia, we explore the psychological depths of characters ravaged by grief. Through an interpretive paradigm and descriptive research design, we unpack the intricate tapestry of the novel, revealing how love's ashes morph into melancholic despair. The loss of loved ones, be it sudden death or betrayal, casts long shadows on the characters' souls, distorting their behavior and twisting their narratives. Altered thoughts, self-blame, and paralyzing yearning become their companions, weaving a tragic dance of longing and despair. ‘Yäqənat Zār’ serves as a powerful testament to the transformative power of storytelling, allowing us to navigate the labyrinthine paths of melancholia and gain a glimpse into the Ethiopian soul grappling with loss. This study not only sheds light on the individual's struggle with sadness but also illuminates the cultural fabric of grief and melancholia intricately woven into Ethiopian society.

Keywords: melancholy, loss, psychoanalysis, grief, identity

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11500 Identifying and Optimizing the Critical Excipients in Moisture Activated Dry Granulation Process for Two Anti TB Drugs of Different Aqueous Solubilities

Authors: K. Srujana, Vinay U. Rao, M. Sudhakar

Abstract:

Isoniazide (INH) a freely water soluble and pyrazinamide (Z) a practically water insoluble first line anti tubercular (TB) drugs were identified as candidates for optimizing the Moisture Activated Dry Granulation (MADG) process. The work focuses on identifying the effect of binder type and concentration as well as the effect of magnesium stearate level on critical quality attributes of Disintegration time (DT) and in vitro dissolution test when the tablets are processed by the MADG process. Also, the level of the drug concentration, binder concentration and fluid addition during the agglomeration stage of the MADG process was evaluated and optimized. For INH, it was identified that for tablets with HPMC as binder at both 2% w/w and 5% w/w level and Magnesium stearate upto 1%w/w as lubrication the DT is within 1 minute and the dissolution rate is the fastest (> 80% in 15 minutes) as compared to when PVP or pregelatinized starch is used as binder. Regarding the process, fast disintegrating and rapidly dissolving tablets are obtained when the level of drug, binder and fluid uptake in agglomeration stage is 25% w/w 0% w/w binder and 0.033%. w/w. At the other 2 levels of these three ingredients, the DT is significantly impacted and dissolution is also slower. For pyrazinamide,it was identified that for the tablets with 2% w/w level of each of PVP as binder and Cross Caramellose Sodium disintegrant the DT is within 2 minutes and the dissolution rate is the fastest(>80 in 15 minutes)as compared to when HPMC or pregelatinized starch is used as binder. This may be attributed to the fact that PVP may be acting as a solubilizer for the practically insoluble Pyrazinamide. Regarding the process,fast dispersing and rapidly disintegrating tablets are obtained when the level of drug, binder and fluid uptake in agglomeration stage is 10% w/w,25% w/w binder and 1% w/w.At the other 2 levels of these three ingredients, the DT is significantly impacted and dissolution is comparatively slower and less complete.

Keywords: agglomeration stage, isoniazide, MADG, moisture distribution stage, pyrazinamide

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11499 Mycophenolate Versus Methotrexate in Non-Infectious Ocular Inflammatory Disease: A Systematic Review and Meta-Analysis

Authors: Mohammad Karam, Abdulmalik Alsaif, Abdulrahman Al-Naseem, Amrit Hayre, Abdurrahman Al Jabbouri, Ahmad Aldubaikhi, Narvair Kahlar, Salem Al-Mutairi

Abstract:

Purpose: To compare the outcomes of mycophenolate mofetil (MMF) versus methotrexate (MTX) in non-infectious ocular inflammatory disease (NIOID). Methods: A systematic review and meta-analysis were performed as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Guidelines and an electronic search was conducted to identify all comparative studies of MMF versus MTX in NIOID. Treatment results and side effects were primary outcome measures. Secondary outcome measures included visual acuity and resolution of macular oedema. Fixed and random-effects models were used for the analysis. Results: Four studies enrolling 905 patients were identified. There was no significant difference between MMF and MTX groups in overall treatment success (Odds Ratio [OR] = 0.97, P = 0.96) and failure (OR = 0.86, P = 0.85) of NIOID. Although treatment success of uveitis showed no significant difference for anterior and intermediate uveitis cases (OR = 2.33, P = 0.14), MTX showed a significantly improved effect in cases involving posterior uveitis and panuveitis (OR = 0.41, P = 0.003). However, the median dose required for treatment success was lower for MTX whereas MMF was associated with a faster median time to treatment success. Further to this, MMF showed a reduced rate of side effects when compared to MTX, but MTX failed to reach statistical significance, most notably for liver enzyme elevation (OR = 0.65, P = 0.16), fatigue (OR = 0.84, P = 0.49) and headache (OR = 0.81, P = 0.37). For secondary outcomes, no significant difference was noted in visual acuity and resolution of macular edema. Conclusions: MMF is comparable to MTX in the treatment of NIOID as there was no significant difference in the outcome of treatment success and side effect profiles.

Keywords: Mycophenolate mofetil, methotrexate, non-infectious ocular inflammation, uveitis, scleritis

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11498 Modeling of Leaks Effects on Transient Dispersed Bubbly Flow

Authors: Mohand Kessal, Rachid Boucetta, Mourad Tikobaini, Mohammed Zamoum

Abstract:

Leakage problem of two-component fluids flow is modeled for a transient one-dimensional homogeneous bubbly flow and developed by taking into account the effect of a leak located at the middle point of the pipeline. The corresponding three conservation equations are numerically resolved by an improved characteristic method. The obtained results are explained and commented in terms of physical impact on the flow parameters.

Keywords: fluid transients, pipelines leaks, method of characteristics, leakage problem

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11497 Study of the Mega–Landslide at the Community of Ropoto, Central Greece, and of the Design of Mitigation and Early Warning System Using the Fiber Bragg Grating Technology

Authors: Michael Bellas, George Voulgaridis

Abstract:

This paper refers to the world known mega - landslide induced at the community of Ropoto, belonging to the Municipality of Trikala, in the Central part of Greece. The landslide affected the debris as well as the colluvium mantle of the flysch, and makes up a special case of study in engineering geology and geotechnical engineering not only because of the size of the domain affected by the landslide (approximately 750m long), but also because of the geostructure’s global behavior. Due to the landslide, the whole community’s infrastructure massively collapsed and human lives were put in danger. After the complete simulation of the coupled Seepage - Deformation phenomenon due to the extreme rainfall, and by closely examining the slope’s global behavior, both the mitigation of the landslide, as well as, an advanced surveillance method (Fiber Bragg Grating) using fiber optics were further studied, in order both to retain the geostructure and to monitor its health by creating an early warning system, which would serve as a complete safety net for saving both the community’s infrastructure as well as the lives of its habitats.

Keywords: landslide, remediation measures, the finite element method (FEM), Fiber Bragg Grating (FBG) sensing method

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11496 Investigations on Enhancement of Fly Ash in Cement Manufacturing through Optimization of Clinker Quality and Fly Ash Fineness

Authors: Suresh Vanguri, Suresh Palla, K. V. Kalyani, S. K. Chaturvedi, B. N. Mohapatra

Abstract:

Enhancing the fly ash utilization in the manufacture of cement is identified as one of the key areas to mitigate the Green House Gas emissions from the cement industry. Though increasing the fly ash content in cement has economic and environmental benefits, it results in a decrease in the compressive strength values, particularly at early ages. Quality of clinker and fly ash were identified as predominant factors that govern the extent of absorption of fly ash in the manufacturing of cement. This paper presents systematic investigations on the effect of clinker and fly ash quality on the properties of resultant cement. Since mechanical activation alters the physicochemical properties such as particle size distribution, surface area, phase morphology, understanding the variation of these properties with activation is required for its applications. The effect of mechanical activation on fly ash surface area, specific gravity, flow properties, lime reactivity, comparative compressive strength (CCS), reactive silica and mineralogical properties were also studied. The fineness of fly ash was determined by Blaine’s method, specific gravity, lime reactivity, CCS were determined as per the method IS 1727-1967. The phase composition of fly ash was studied using the X-ray Diffraction technique. The changes in the microstructure and morphology with activation were examined using the scanning electron microscope. The studies presented in this paper also include evaluation of Portland Pozzolana Cement (PPC), prepared using high volume fly ash. Studies are being carried out using clinker from cement plants located in different regions/clusters in India. Blends of PPC containing higher contents of activated fly ash have been prepared and investigated for their chemical and physical properties, as per Indian Standard procedures. Changes in the microstructure of fly ash with activation and mechanical properties of resultant cement containing high volumes of fly ash indicated the significance of optimization of the quality of clinker and fly ash fineness for better techno-economical benefits.

Keywords: flow properties, fly ash enhancement, lime reactivity, microstructure, mineralogy

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11495 Suitability Evaluation of Human Settlements Using a Global Sensitivity Analysis Method: A Case Study in of China

Authors: Feifei Wu, Pius Babuna, Xiaohua Yang

Abstract:

The suitability evaluation of human settlements over time and space is essential to track potential challenges towards suitable human settlements and provide references for policy-makers. This study established a theoretical framework of human settlements based on the nature, human, economy, society and residence subsystems. Evaluation indicators were determined with the consideration of the coupling effect among subsystems. Based on the extended Fourier amplitude sensitivity test algorithm, the global sensitivity analysis that considered the coupling effect among indicators was used to determine the weights of indicators. The human settlement suitability was evaluated at both subsystems and comprehensive system levels in 30 provinces of China between 2000 and 2016. The findings were as follows: (1) human settlements suitability index (HSSI) values increased significantly in all 30 provinces from 2000 to 2016. Among the five subsystems, the suitability index of the residence subsystem in China exhibited the fastest growinggrowth, fol-lowed by the society and economy subsystems. (2) HSSI in eastern provinces with a developed economy was higher than that in western provinces with an underdeveloped economy. In con-trast, the growing rate of HSSI in eastern provinces was significantly higher than that in western provinces. (3) The inter-provincial difference of in HSSI decreased from 2000 to 2016. For sub-systems, it decreased for the residence system, whereas it increased for the economy system. (4) The suitability of the natural subsystem has become a limiting factor for the improvement of human settlements suitability, especially in economically developed provinces such as Beijing, Shanghai, and Guangdong. The results can be helpful to support decision-making and policy for improving the quality of human settlements in a broad nature, human, economy, society and residence context.

Keywords: human settlements, suitability evaluation, extended fourier amplitude, human settlement suitability

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11494 Experimental Study on Performance of a Planar Membrane Humidifier for a Proton Exchange Membrane Fuel Cell Stack

Authors: Chen-Yu Chen, Wei-Mon Yan, Chi-Nan Lai, Jian-Hao Su

Abstract:

The proton exchange membrane fuel cell (PEMFC) becomes more important as an alternative energy source recently. Maintaining proper water content in the membrane is one of the key requirements for optimizing the PEMFC performance. The planar membrane humidifier has the advantages of simple structure, low cost, low-pressure drop, light weight, reliable performance and good gas separability. Thus, it is a common external humidifier for PEMFCs. In this work, a planar membrane humidifier for kW-scale PEMFCs is developed successfully. The heat and mass transfer of humidifier is discussed, and its performance is analyzed in term of dew point approach temperature (DPAT), water vapor transfer rate (WVTR) and water recovery ratio (WRR). The DPAT of the humidifier with the counter flow approach reaches about 6°C under inlet dry air of 50°C and 60% RH and inlet humid air of 70°C and 100% RH. The rate of pressure loss of the humidifier is 5.0×10² Pa/min at the torque of 7 N-m, which reaches the standard of commercial planar membrane humidifiers. From the tests, it is found that increasing the air flow rate increases the WVTR. However, the DPAT and the WRR are not improved by increasing the WVTR as the air flow rate is higher than the optimal value. In addition, increasing the inlet temperature or the humidity of dry air decreases the WVTR and the WRR. Nevertheless, the DPAT is improved at elevated inlet temperatures or humidities of dry air. Furthermore, the performance of the humidifier with the counter flow approach is better than that with the parallel flow approach. The DPAT difference between the two flow approaches reaches up to 8 °C.

Keywords: heat and mass transfer, humidifier performance, PEM fuel cell, planar membrane humidifier

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11493 Energy Efficient Building Design in Nigeria: An Assessment of the Effect of the Sun on Energy Consumption in Residential Buildings

Authors: Ekele T. Ochedi, Ahmad H. Taki, Birgit Painter

Abstract:

The effect of the sun and its path on thermal comfort and energy consumption in residential buildings in tropical climates constitute a serious concern for designers, building owners, and users. Passive design approaches based on the sun and its path have been identified as a means of reducing energy consumption as well as enhancing thermal comfort in buildings worldwide. Hence, a thorough understanding regarding the sun path is key to achieving this. This is necessary due to energy need, poor energy supply, and distribution, energy poverty, and over-dependence on electric generators for power supply in Nigeria. These challenges call for a change in the approach to energy-related issues, especially in terms of buildings. The aim of this study is to explore the influence of building orientation, glazing and the use of shading devices on residential buildings in Nigeria. This is intended to provide data that will guide designers in the design of energy-efficient residential buildings. The paper used EnergyPlus to analyze a typical semi-detached residential building in Lokoja, Nigeria using hourly weather data for a period of 10 years. Building performance was studied as well as possible improvement regarding different orientations, glazing types and shading devices. The simulation results show some reductions in energy consumption in response to changes in building orientation, types of glazing and the use of shading devices. The results indicate 29.45% reduction in solar gains and 1.90% in annual operative temperature using natural ventilation only. This shows a huge potential to reduce energy consumption and improve people’s well-being through the use of proper building orientation, glazing and appropriate shading devices on building envelope. The study concludes that for a significant reduction in total energy consumption by residential buildings, the design should focus on multiple design options rather than concentrating on one or few building elements. Moreover, the investigation confirms that energy performance modeling can be used by building designers to take advantage of the sun and to evaluate various design options.

Keywords: energy consumption, energy-efficient buildings, glazing, thermal comfort, shading devices, solar gains

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11492 Effect of Insulin versus Green Tea on the Parotid Gland of Streptozotocin Induced Diabetic Rats

Authors: H. El-Messiry, M. El-Zainy, D. Ghazy

Abstract:

Diabetes is a metabolic disease that results in a variety of oral health complications. Green tea is a natural antioxidant proved to have powerful effects against diabetes. The aim of this study was to compare between the effect of insulin and green tea on the Parotid gland of streptozotocin induced diabetic Albino rats by using light and transmission electron microscopy. Forty male Albino rats were divided into control group and diabetic groups. The diabetic group received a single injection of 40 mg/kg of streptozotocin intra-peritoneal under anesthesia and was further subdivided into three subgroups: The diabetic untreated subgroup which was untreated for two weeks, the insulin treated subgroup which has received insulin subcutaneously in a daily dose of 5 IU/kg body weight/day for two weeks and a green tea treated subgroup received a daily dose of 1 ml/ 100 gm body weight intragastrically for two weeks. Rats were terminated and parotid glands were dissected and processed for light and transmission electron microscopic examination. Histological examination of the diabetic untreated subgroup revealed acinar cells with pyknotic and hyperchromatic nuclei with cytoplasmic vacuolations. Ultrastructurally, acinar cells showed nuclear pleomorphism, dilated rough endoplasmic reticulum and swollen mitochondria with damaged cristae. Inflammatory cell infiltration was detected both histologically and ultrastructurally. Ducts showed signs of degeneration with loss of their normal outline and stagnated secretion within the lumen. However, insulin and green tea treated subgroups showed minimal degenerative damage and were almost similar to the control with minimal changes. Treatment of the parotid gland of the streptozotocin induced diabetic rats with GT was closely comparable to the traditional insulin therapy in reducing signs of histological and ultrastructural damage.

Keywords: diabetes, green tea, insulin, parotid

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11491 Analysis of the Effect of Farmers’ Socio-Economic Factors on Net Farm Income of Catfish Farmers in Kwara State, Nigeria

Authors: Olanike A. Ojo, Akindele M. Ojo, Jacob H. Tsado, Ramatu U. Kutigi

Abstract:

The study was carried out on analysis of the effect of farmers’ socio-economic factors on the net farm income of catfish farmers in Kwara State, Nigeria. Primary data were collected from selected catfish farmers with the aid of well-structured questionnaire and a multistage sampling technique was used to select 102 catfish farmers in the area. The analytical techniques involved the use of descriptive statistics and multiple regression analysis. The findings of the analysis of socio-economic characteristics of catfish farmers reveal that 60% of the catfish farmers in the study area were male gender which implied the existence of gender inequality in the area. The mean age of 47 years was an indication that they were at their economically productive age and could contribute positively to increased production of catfish in the area. Also, the mean household size was five while the mean year of experience was five. The latter implied that the farmers were experienced in fishing techniques, breeding and fish culture which would assist in generating more revenue, reduce cost of production and eventual increase in profit levels of the farmers. The result also revealed that stock capacity (X3), accessibility to credit (X7) and labour (X4) were the main determinants of catfish production in the area. In addition, farmer’s sex, household size, no of ponds, distance of the farm from market, access to credit were the main socio-economic factors influencing the net farm income of the catfish farmers in the area. The most serious constraints militating against catfish production in the study area were high mortality rate, insufficient market, inadequate credit facilities/ finance and inadequate skilled labour needed for daily production routine. Based on the findings, it is therefore recommended that, to reduce the mortality rate of catfish extension agents should organize training workshops on improved methods and techniques of raising catfish right from juvenile to market size.

Keywords: credit, income, stock, mortality

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11490 Impact of Gamma Irradiation on Biological Activities of Artemisia herba alba from Algeria

Authors: Abir Mohamed Mohamed Ibrahim, Amina Titouche, Mohamed Hazzit

Abstract:

Phytotherapy is based on use of plant natural products holding the main sources of drugs with healing properties for the treatment of human, animal or vegetable diseases. With these aims, and to replace chemical preservatives in natural products, we are interested to use essential oils from Algerian endemic plants belonging to the Asteraceae family: Artemisia herba alba Asso, which was undergoes a hydro-distillation after its irradiation by Gamma rays at frequencies: 10, 20, and 30 KGray which gave respectively the following essential oil yields: 1.087%, 1.087%, 1.085%, compared with that of the untreated sample giving a yield of 1.27 %. Evaluation of the antioxidant activity in vitro of essential oil for A. herba alba has been assessed by two different methods: inhibition of DPPH radical and measurement of reducing power. The first method has not revealed a very big difference regardless of the dose of irradiation, the IC50 is about 4000 mg/l, the maximum of inhibition was around 49.4%, likewise, the test of reducing power awarded us a maximum reducing capacity was of 0.76%; both of results were registered by the specimen irradiated at 20 KGy, it has a more better antioxidant power than no irradiated sample but slightly. To combat Fusarium culmorum, causing the wilts and rots, we are focused on the antifungal screening of this aromatic plant. The results obtained, followed by measurements of Minimal Inhibitory Concentrations (MIC); showed promising inhibitory effect against pathogen tested. With a yield superior to l%, the essential oil has shown a remarkable efficiency on the stump, mainly for sample irradiate at 30KGray (MICs= 625 µg/ml; MICc= 1250 µg/ml) with MIC of 2%. These results demonstrate a good antifungal activity, to limit and even to stop the development of the pathogenic microorganism and also the positive effect of dose of irradiation to upgrade this capacity as well, to uphold the antioxidant capacity.

Keywords: artemisia herba alba Asso, essential oil yield, gamma ray, antioxidant activity, antifungal activity

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11489 Use of Giant Magneto Resistance Sensors to Detect Micron to Submicron Biologic Objects

Authors: Manon Giraud, Francois-Damien Delapierre, Guenaelle Jasmin-Lebras, Cecile Feraudet-Tarisse, Stephanie Simon, Claude Fermon

Abstract:

Early diagnosis or detection of harmful substances at low level is a growing field of high interest. The ideal test should be cheap, easy to use, quick, reliable, specific, and with very low detection limit. Combining the high specificity of antibodies-functionalized magnetic beads used to immune-capture biologic objects and the high sensitivity of a GMR-based sensors, it is possible to even detect these biologic objects one by one, such as a cancerous cell, a bacteria or a disease biomarker. The simplicity of the detection process makes its use possible even for untrained staff. Giant Magneto Resistance (GMR) is a recently discovered effect consisting in the electrical resistance modification of some conductive layers when exposed to a magnetic field. This effect allows the detection of very low variations of magnetic field (typically a few tens of nanoTesla). Magnetic nanobeads coated with antibodies targeting the analytes are mixed with a biological sample (blood, saliva) and incubated for 45 min. Then the mixture is injected in a very simple microfluidic chip and circulates above a GMR sensor that detects changes in the surrounding magnetic field. Magnetic particles do not create a field sufficient to be detected. Therefore, only the biological objects surrounded by several antibodies-functionalized magnetic beads (that have been captured by the complementary antigens) are detected when they move above the sensor. Proof of concept has been carried out on NS1 mouse cancerous cells diluted in PBS which have been bonded to magnetic 200nm particles. Signals were detected in cells-containing samples while none were recorded for negative controls. Binary response was hence assessed for this first biological model. The precise quantification of the analytes and its detection in highly diluted solution is the step now in progress.

Keywords: early diagnosis, giant magnetoresistance, lab-on-a-chip, submicron particle

Procedia PDF Downloads 238
11488 Antioxydant Properties and Gastroprotective Effect of Rosa canina Aqueous Extract against Alcohol-Induced Ulceration and Oxidative Stress in Rat Model

Authors: H. Sebai, M. A. Jabria, D. Wannes, H. Tounsi, L. Marzouki

Abstract:

We aimed in the present study to investigate the protective effects of Tunisian Rosa canina aqueous extract (RCAE) against ethanol-induced gastric ulceration and oxidative stress in a rat model. In this respect, adult male Wistar rats were used and divided into six groups of ten each: control, EtOH, EtOH plus various doses of RCAE, EtOH plus famotidine and EtOH + gallic acid. Phytochemical and biochemical analysis were performed using colorimetric methods. We found that RCAE is rich in total polyphenols, total flavonoids, and condensed tannins, and exhibited an importance in vitro antioxidant activity on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. In vivo, the results showed that oral administration of EtOH caused macroscopic and histological changes in gastric mucosa. These injuries are accompanied by an oxidative stress status as assessed by an increase of lipid peroxidation as well as a decrease of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Alcohol intoxication also induced intracellular mediators deregulation as assessed by an increase of hydrogen peroxide (H2O2), calcium and free iron levels in gastric mucosa. More, importantly, RCAE pretreatment reversed all macroscopic, histological and biochemical changes induced by EtOH administration. In conclusion, we suggest that RCAE has potent protective effects on acute ethanol-induced gastric ulceration related in part in part its antioxidant properties and its opposite effect on intracellular mediators. Indeed, Rosa canina can be offered as a food additive to protect against alcohol consumption-induced gastric and oxidative damage.

Keywords: alcohol, antioxidant properties, food additive, gastric ulceration, rat model, Rosa canina

Procedia PDF Downloads 186
11487 Impact of Output Market Participation on Cassava-Based Farming Households' Welfare in Nigeria

Authors: Seyi Olalekan Olawuyi, Abbyssiania Mushunje

Abstract:

The potential benefits of agricultural production to improve the welfare condition of smallholder farmers in developing countries is no more a news because it has been widely documented. Yet majority of these farming households suffer from shortfall in production output to meet both the consumption needs and market demand which adversely affects output market participation and by extension welfare condition. Therefore, this study investigated the impacts of output market participation on households’ welfare of cassava-based farmers in Oyo State, Nigeria. Multistage sampling technique was used to select 324 sample size used for this study. The findings from the data obtained and analyzed through composite score and crosstab analysis revealed that there is varying degree of output market participation among the farmers which also translate to the observed welfare profile differentials in the study area. The probit model analysis with respect to the selection equation identified gender of household head, household size, access to remittance, off-farm income and ownership of farmland as significant drivers of output market participation in the study area. Furthermore, the treatment effect model of the welfare equation and propensity score matching (PSM) technique were used as robust checks; and the findings attest to the fact that, complimentarily with other significant variables highlighted in this study, output market participation indeed has a significant impact on farming households’ welfare. As policy implication inferences, the study recommends female active inclusiveness and empowerment in farming activities, birth control strategies, secondary income smoothing activities and discouragement of land fragmentation habits, to boost productivity and output market participation, which by extension can significantly improve farming households’ welfare.

Keywords: Cassava market participation, households' welfare, propensity score matching, treatment effect model

Procedia PDF Downloads 148
11486 Internal Product Management: The Key to Achieving Digital Maturity and Business Agility for Manufacturing IT Organizations

Authors: Frederick Johnson

Abstract:

Product management has a long and well-established history within the consumer goods industry, despite being one of the most obscure aspects of brand management. Many global manufacturing organizations are now opting for external cloud-based Manufacturing Execution Systems (MES) to replace costly and outdated monolithic MES solutions. Other global manufacturing leaders are restructuring their organizations to support human-centered values, agile methodologies, and fluid operating principles. Still, industry-leading organizations struggle to apply the appropriate framework for managing evolving external MES solutions as internal "digital products." Product management complements these current trends in technology and philosophical thinking in the market. This paper discusses the central problems associated with adopting product management processes by analyzing its traditional theories and characteristics. Considering these ideas, the article then constructs a translated internal digital product management framework by combining new and existing approaches and principles. The report concludes by demonstrating the framework's capabilities and potential effectiveness in achieving digital maturity and business agility within a manufacturing environment.

Keywords: internal product management, digital transformation, manufacturing information technology, manufacturing execution systems

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11485 Analyzing Log File of Community Question Answering for Online Learning

Authors: Long Chen

Abstract:

With the proliferation of E-Learning, collaborative learning becomes more and more popular in various teaching and learning occasions. Studies over the years have proved that actively participating in classroom discussion can enhance student's learning experience, consolidating their knowledge and understanding of the class content. Collaborative learning can also allow students to share their resources and knowledge by exchanging, absorbing, and observing one another's opinions and ideas. Community Question Answering (CQA) services are particularly suitable paradigms for collaborative learning, since it is essentially an online collaborative learning platform where one can get information from multiple sources for he/her to choose from. However, current CQA services have only achieved limited success in collaborative learning due to the uncertainty of answers' quality. In this paper, we predict the quality of answers in a CQA service, i.e. Yahoo! Answers, for the use of online education and distance learning, which would enable a student to find relevant answers and potential answerers more effectively and efficiently, and thus greatly increase students' user experience in CQA services. Our experiment reveals that the quality of answers is influenced by a series of factors such as asking time, relations between users, and his/her experience in the past. We also show that by modelling user's profile with our proposed personalized features, student's satisfaction towards the provided answers could be accurately estimated.

Keywords: Community Question Answering, Collaborative Learning, Log File, Co-Training

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11484 A Comprehensive Study of a Hybrid System Integrated Solid Oxide Fuel cell, Gas Turbine, Organic Rankine Cycle with Compressed air Energy Storage

Authors: Taiheng Zhang, Hongbin Zhao

Abstract:

Compressed air energy storage become increasingly vital for solving intermittency problem of some renewable energies. In this study, a new hybrid system on a combination of compressed air energy storage (CAES), solid oxide fuel cell (SOFC), gas turbine (GT), and organic Rankine cycle (ORC) is proposed. In the new system, excess electricity during off-peak time is utilized to compress air. Then, the compressed air is stored in compressed air storage tank. During peak time, the compressed air enters the cathode of SOFC directly instead of combustion chamber of traditional CAES. There is no air compressor consumption of SOFC-GT in peak demand, so SOFC- GT can generate power with high-efficiency. In addition, the waste heat of exhaust from GT is recovered by applying an ORC. Three different organic working fluid (R123, R601, R601a) of ORC are chosen to evaluate system performance. Based on Aspen plus and Engineering Equation Solver (EES) software, energy and exergoeconomic analysis are used to access the viability of the combined system. Besides, the effect of two parameters (fuel flow and ORC turbine inlet pressure) on energy efficiency is studied. The effect of low-price electricity at off-peak hours on thermodynamic criteria (total unit exergy cost of products and total cost rate) is also investigated. Furthermore, for three different organic working fluids, the results of round-trip efficiency, exergy efficiency, and exergoeconomic factors are calculated and compared. Based on thermodynamic performance and exergoeconomic performance of different organic working fluids, the best suitable working fluid will be chosen. In conclusion, this study can provide important guidance for system efficiency improvement and viability.

Keywords: CAES, SOFC, ORC, energy and exergoeconomic analysis, organic working fluids

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11483 Effect of Feeding Varying Levels of Dietary Cation-Anion Difference on the Performance of Transition Sahiwal Cattle

Authors: Farhan Ahmad Atif, Abd Ur Rehman, Muhammad Babir

Abstract:

Dietary cation anion difference (DCAD) is an important aspect of dairy nutrition, especially in the transition period. Sahiwal cattle is the highest milk producing breed among Zebu cattle. We planned first study on transition Sahiwal cattle to determine the effects of feeding varying levels of negative DCAD. For this purpose, twenty pregnant cows (at the 250th day of gestation) were selected and randomly divided into 5 groups comprising four animals each. Five iso-caloric (2100 Kcal) and iso-nitrogenous (12%) diets were formulated and each diet was allotted to each group. The animals received positive DCAD diet served as control. Diets were supplemented with NutriCAB® to attain 0, -15, -30 and -45 DCAD levels. Experimental diets were fed at ad-libitum upto parturition and data regarding feed intake were recorded on daily. Post-partum incidence of milk fever, dystocia, retention of placenta (RP), mastitis as well as milk production, milk fat percentage and serum Ca levels were recorded. Urine and blood pH were determined weekly during the last month of pregnancy. Results showed that prepartum feed intake and blood pH were not affected (P > 0.05), while urine pH was significantly reduced (P < 0.05) by lowering DCAD levels. Post parturient blood calcium level linearly increased (P < 0.05) with decreasing DCAD. Pre-partum negative DCAD feeding had no effect (P > 0.05) on post-parturient milk production and fat percentage. However, parturient related problems decreased with decreasing DCAD feeding. It was concluded that negative DCAD feeding raised serum calcium level and reduced the incidence of post-parturient problems in Sahiwal cattle.

Keywords: dairy cattle, transition, metabolic diseases, reproductive disorders, incidence

Procedia PDF Downloads 179
11482 Exploring the Contribution of Higher Education to Sustainable Development: A Bibliometric Analysis of Research on Social Sustainability

Authors: Mestawot Beyene Tafese, Erika Kopp

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Sustainable development, aimed at meeting current needs while safeguarding the needs of future generations, is a global imperative. Higher education stands as a pivotal force in fostering sustainable values and behaviors. However, most scholars and governments primarily focus on environmental and economic aspects. Consequently, this study examines the distribution patterns of higher education for social sustainability. The study highlights overall annual scientific production trends, leading journals and countries in scientific publication, most researched topics, and frequently used keywords. The study utilized a bibliometric method with the aid of the R Studio program. The analysis reveals Sustainability (Switzerland) as the leading journal, with 292 articles published, followed by the International Journal of Sustainability in Higher Education, which published 186 articles. Additionally, the USA is identified as the leading country, with Spain ranking second in producing research related to higher education for socially sustainable development. Among the 54 African countries, only South Africa ranks 13th, contributing fifty-nine scientific articles. Furthermore, higher education for sustainability, sustainable education, sustainable development goals, etc., emerge as the most researched topics, while the term "higher education" is prevalent in 29% and "sustainability" in 28% of the documents. Notably, according to the analysis, social sustainability is the focus of only 3% of articles. This suggests that academics researching sustainable development and higher education have overlooked social sustainability, a crucial human component of sustainable development. Consequently, the researchers concluded that social academics who are interested in studying sustainable development and higher education should give priority to social sustainability.

Keywords: higher education, bibliometric analysis, social sustainability, sustainable development

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11481 Evaluating the Prominence of Chemical Phenomena in Chemistry Courses

Authors: Vanessa R. Ralph, Leah J. Scharlott, Megan Y. Deshaye, Ryan L. Stowe

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Given the traditions of chemistry teaching, one may not question whether chemical phenomena play a prominent role. Yet, the role of chemical phenomena in an introductory chemistry course may define the extent to which the course is introductory, chemistry, and equitable. Picture, for example, the classic Ideal Gas Law problem. If one envisions a prompt wherein students are tasked with calculating a missing variable, then one envisions a prompt that relies on chemical phenomena as a context rather than as a model to understand the natural world. Consider a prompt wherein students are tasked with applying molecular models of gases to explain why the vapor pressure of a gaseous solution of water differs from that of carbon dioxide. Here, the chemical phenomenon is not only the context but also the subject of the prompt. Deliveries of general and organic chemistry were identified as ranging wildly in the integration of chemical phenomena. The more incorporated the phenomena, the more equitable the assessment task was for students of varying access to pre-college math and science preparation. How chemical phenomena are integrated may very well define whether courses are chemistry, are introductory, and are equitable. Educators of chemistry are invited colleagues to discuss the role of chemical phenomena in their courses and consider the long-lasting impacts of replicating tradition for tradition’s sake.

Keywords: equitable educational practices, chemistry curriculum, content organization, assessment design

Procedia PDF Downloads 182
11480 Correlates of Work-Family Role Conflict and Well-Being: A Comparative Analysis by Gender

Authors: Liat Kulik

Abstract:

The main goal of the present study was to examine gender differences in the variables that explain the experience of role conflict and well-being among Jewish working fathers and mothers in the Israel. The experience of work-family conflict arises from simultaneous pressures from the work and family domains that are mutually incompatible. In light of the expansion of women's role set following the addition of paid employment outside of the home, most of the studies dealing with the impact of multiple roles on well-being have been conducted among women. However, changes in gender roles in recent years have also affected men's role set, as reflected in the terms ‘new men’ and ‘new fathers’. Based on structural equation modeling, the study examined gender differences in variables that explain the experience of two types of role conflict – family interferes with work (FIW) and work interferes with family (WIF), as well as with the sense of well-being (positive and negative affect) among 611 employed Jewish mothers and fathers in Israel. The findings revealed that for women, both FIW and WIF conflict correlated negatively with well-being, whereas for men, a negative correlation with well-being was found only in the case of FIW conflict. For both men and women, egalitarian gender role ideology correlated with the dimension of positive effect, but the correlation was stronger for men. The findings highlight the contribution of egalitarian gender role ideology to alleviating the experience of role conflict and improving the emotional well-being of both men and women. Contrary to expectations, social support contributed more to mitigating negative effect among men than women. On the whole, the findings highlight the changes that men have experienced in the work-family system. In sum, the research findings shed new light on the masculine image in terms of the experience of FIW conflict. In contrast to the prevailing assumption that FIW role conflict is predominant among women, the findings of this study indicate that today, this type of role conflict is experienced equally by men and women whereas WIF conflict is predominant among men. Furthermore, contrary to expectations, levels of perceived social support were found to be similar for men and women, and men benefited from it even more than women did.

Keywords: FIW conflict, WIF conflict, social support, egalitarian gender role ideology, overload

Procedia PDF Downloads 273
11479 Study on the Influence of Different Lengths of Tunnel High Temperature Zones on Train Aerodynamic Resistance

Authors: Chong Hu, Tiantian Wang, Zhe Li, Ourui Huang, Yichen Pan

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When the train is running in a high geothermal tunnel, changes in the temperature field will cause disturbances in the propagation and superposition of pressure waves in the tunnel, which in turn have an effect on the aerodynamic resistance of the train. The aim of this paper is to investigate the effect of the changes in the lengths of the high-temperature zone of the tunnel on the aerodynamic resistance of the train, clarifying the evolution mechanism of aerodynamic resistance of trains in tunnels with high ground temperatures. Firstly, moving model tests of trains passing through wall-heated tunnels were conducted to verify the reliability of the numerical method in this paper. Subsequently, based on the three-dimensional unsteady compressible RANS method and the standard k-ε two-equation turbulence model, the change laws of the average aerodynamic resistance under different high-temperature zone lengths were analyzed, and the influence of frictional resistance and pressure difference resistance on total resistance at different times was discussed. The results show that as the length of the high-temperature zone LH increases, the average aerodynamic resistance of a train running in a tunnel gradually decreases; when LH = 330 m, the aerodynamic resistance can be reduced by 5.7%. At the moment of maximum resistance, the total resistance, differential pressure resistance, and friction resistance all decrease gradually with the increase of LH and then remain basically unchanged. At the moment of the minimum value of resistance, with the increase of LH, the total resistance first increases and then slowly decreases; the differential pressure resistance first increases and then remains unchanged, while the friction resistance first remains unchanged and then gradually decreases, and the ratio of the differential pressure resistance to the total resistance gradually increases with the increase of LH. The results of this paper can provide guidance for scholars who need to investigate the mechanism of aerodynamic resistance change of trains in high geothermal environments, as well as provide a new way of thinking for resistance reduction in non-high geothermal tunnels.

Keywords: high-speed trains, aerodynamic resistance, high-ground temperature, tunnel

Procedia PDF Downloads 50
11478 Mentor and Mentee Based Learning

Authors: Erhan Eroğlu

Abstract:

This paper presents a new method called Mentor and Mentee Based Learning. This new method is becoming more and more common especially at workplaces. This study is significant as it clearly underlines how it works well. Education has always aimed at equipping people with the necessary knowledge and information. For many decades it went on teachers’ talk and chalk methods. In the second half of the nineteenth century educators felt the need for some changes in delivery systems. Some new terms like self- discovery, learner engagement, student centered learning, hands on learning have become more and more popular for such a long time. However, some educators believe that there is much room for better learning methods in many fields as they think the learners still cannot fulfill their potential capacities. Thus, new systems and methods are still being developed and applied at education centers and work places. One of the latest methods is assigning some mentors for the newly recruited employees and training them within a mentor and mentee program which allows both parties to see their strengths and weaknesses and the areas which can be improved. This paper aims at finding out the perceptions of the mentors and mentees on the programs they are offered at their workplaces and suggests some betterment alternatives. The study has been conducted via a qualitative method whereby some interviews have been done with both mentors and mentees separately and together. Results show that it is a great way to train inexperienced one and also to refresh the older ones. Some points to be improved have also been underlined. The paper shows that education is not a one way path to follow.

Keywords: learning, mentor, mentee, training

Procedia PDF Downloads 215