Search results for: vibration analyses
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4213

Search results for: vibration analyses

2473 Effect of Defect Dipoles And Microstructure Engineering in Energy Storage Performance of Co-doped Barium Titanate Ceramics

Authors: Mahmoud Saleh Mohammed Alkathy

Abstract:

Electricity generated from renewable resources may help the transition to clean energy. A reliable energy storage system is required to use this energy properly. To do this, a high breakdown strength (Eb) and a significant difference between spontaneous polarization (Pmax) and remnant polarization (Pr) are required. To achieve this, the defect dipoles in lead free BaTiO3 ferroelectric ceramics are created using Mg2+ and Ni2+ ions as acceptor co-doping in the Ti site. According to the structural analyses, the co-dopant ions were effectively incorporated into the BTO unit cell. According to the ferroelectric study, the co-doped samples display a double hysteresis loop, stronger polarization, and high breakdown strength. The formation of oxygen vacancies and defect dipoles prevent domains' movement, resulting in hysteresis loop pinching. This results in increased energy storage density and efficiency. The defect dipoles mechanism effect can be considered a fascinating technology that can guide the researcher working on developing energy storage for next-generation applications.

Keywords: microstructure, defect, energy storage, effciency

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2472 An Exploration of the Effects of Individual and Interpersonal Factors on Saudi Learners' Motivation to Learn English as a Foreign Language

Authors: Fakieh Alrabai

Abstract:

This paper presents an experimental study designed to explore some of the learner’s individual and interpersonal factors (e.g. persistence, interest, regulation, satisfaction, appreciation, etc.) that Saudi learners experience when learning English as a Foreign Language and how learners’ perceptions of these factors influence various aspects of their motivation to learn English language. As part of the study, a 27-item structured survey was administered to a randomly selected sample of 105 Saudi learners from public schools and universities. Data collected through the survey were subjected to some basic statistical analyses, such as "mean" and "standard deviation". Based on the results from the analysis, a number of generalizations and conclusions are made in relation to how these inherent factors affect Saudi learners’ motivation to learn English as a foreign language. In addition, some recommendations are offered to Saudi academics on how to effectively make use of such factors, which may enable Saudi teachers and learners of English as a foreign language to achieve better learning outcomes in an area widely associated by Saudis with lack of success.

Keywords: persistence, interest, appreciation, satisfaction, SL/FL motivation

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2471 Incentivize Contracting Partners of Public Projects

Authors: Sai On Cheung, Qiuwen Ma, Fong Chung Lee

Abstract:

Due to increased project complexity and technological advancement in the last decade, the designers and contractors are expected to put more efforts to achieve project goals. To render extra efforts from the agents, incentivization has become one of the primary strategies for the client. Despite increased academia interest in the design of incentive strategies, there is still a need for discussion about the underlying motivations and favourable conditions to make incentives effective. Therefore, this study focuses on the effects of motivations and favourable conditions for the use of incentives in public projects. Questionnaire survey is used as the data collection tool. The questionnaire survey was piloted through interviews with professionals from Hong Kong public sector. A total of 100 responses were collected for this survey. Accountability and organizational effectiveness were found to be the prime objectives of incentives installed by public clients. Furthermore, a list of favourable conditions for incentivization and its consequent effects on cost, schedule, risk and public opinions were identified. To conclude, this study analyses the means and ends of the use of incentives in public projects in Hong Kong.

Keywords: incentives, public accountability, project effectiveness, public opinions

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2470 The Investigation of Correlation between Body Composition and Physical Activity in University Students

Authors: Ferruh Taspinar, Gulce K. Seyyar, Gamze Kurt, Eda O. Okur, Emrah Afsar, Ismail Saracoglu, Betul Taspinar

Abstract:

Alterations of physical activity can effect body composition (especially body fat ratio); however body mass index may not sufficient to indicate these minimal differences. The aim of this study was to evaluate the relationship between body composition and physical activity in university students. In this study, 132 university students (mean age; 21.21±1.51) were included. Tanita BC-418 and International Physical Activity Questionnaire (IPAQ) were used to evaluate participants. The correlation between the parameters was analysed via Spearman correlation analysis. Significance level in statistical analyses was accepted is 0.05. The results showed that there was no correlation between body mass index and physical activity (p>0.05). There was a positive correlation between body muscle ratio and physical activity, whereas a negative correlation between body fat ratio and physical activity (p<0.05). This study showed that body fat and muscle ratio affects the level of physical activity in healthy university students. Therefore, we thought that physical activity might reduce effects of the diseases caused by disturbed body composition. Further studies are required to support this idea.

Keywords: body composition, body mass index, physical activity, university student

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2469 Clinical Profile of Oral Sensory Abilities in Developmental Dysarthria

Authors: Swapna N., Deepthy Ann Joy

Abstract:

One of the major causes of communication disorders in pediatric population is Motor speech disorders. These disorders which affect the motor aspects of speech articulators can have an adverse effect on the communication abilities of children in their developmental period. The motor aspects are dependent on the sensory abilities of children with motor speech disorders. Hence, oral sensorimotor evaluation is an important component in the assessment of children with motor speech disorders. To our knowledge, the importance of oral motor examination has been well established, yet the sensory assessment of the oral structures has received less focus. One of the most common motor speech disorders seen in children is developmental dysarthria. The present study aimed to assess the orosensory aspects in children with developmental dysarthria (CDD). The control group consisted of 240 children in the age range of four and eight years which was divided into four subgroups (4-4.11, 5-5.11, 6-6.11 and 7-7.11 years). The experimental group consisted of 15 children who were diagnosed with developmental dysarthria secondary to cerebral palsy who belonged in the age range of four and eight years. The oro-sensory aspects such as response to touch, temperature, taste, texture, and orofacial sensitivity were evaluated and profiled. For this purpose, the authors used the ‘Oral Sensorimotor Evaluation Protocol- Children’ which was developed by the authors. The oro-sensory section of the protocol was administered and the clinical profile of oro-sensory abilities of typically developing children and CDD was obtained for each of the sensory abilities. The oro-sensory abilities of speech articulators such as lips, tongue, palate, jaw, and cheeks were assessed in detail and scored. The results indicated that experimental group had poorer scores on oro-sensory aspects such as light static touch, kinetic touch, deep pressure, vibration and double simultaneous touch. However, it was also found that the experimental group performed similar to control group on few aspects like temperature, taste, texture and orofacial sensitivity. Apart from the oro-motor abilities which has received utmost interest, the variation in the oro-sensory abilities of experimental and control group is highlighted and discussed in the present study. This emphasizes the need for assessing the oro-sensory abilities in children with developmental dysarthria in addition to oro-motor abilities.

Keywords: cerebral palsy, developmental dysarthria, orosensory assessment, touch

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2468 Experimental and Numerical Analyses of Tehran Research Reactor

Authors: A. Lashkari, H. Khalafi, H. Khazeminejad, S. Khakshourniya

Abstract:

In this paper, a numerical model is presented. The model is used to analyze a steady state thermo-hydraulic and reactivity insertion transient in TRR reference cores respectively. The model predictions are compared with the experiments and PARET code results. The model uses the piecewise constant and lumped parameter methods for the coupled point kinetics and thermal-hydraulics modules respectively. The advantages of the piecewise constant method are simplicity, efficiency and accuracy. A main criterion on the applicability range of this model is that the exit coolant temperature remains below the saturation temperature, i.e. no bulk boiling occurs in the core. The calculation values of power and coolant temperature, in steady state and positive reactivity insertion scenario, are in good agreement with the experiment values. However, the model is a useful tool for the transient analysis of most research reactor encountered in practice. The main objective of this work is using simple calculation methods and benchmarking them with experimental data. This model can be used for training proposes.

Keywords: thermal-hydraulic, research reactor, reactivity insertion, numerical modeling

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2467 Optimal Design of Friction Dampers for Seismic Retrofit of a Moment Frame

Authors: Hyungoo Kang, Jinkoo Kim

Abstract:

This study investigated the determination of the optimal location and friction force of friction dampers to effectively reduce the seismic response of a reinforced concrete structure designed without considering seismic load. To this end, the genetic algorithm process was applied and the results were compared with those obtained by simplified methods such as distribution of dampers based on the story shear or the inter-story drift ratio. The seismic performance of the model structure with optimally positioned friction dampers was evaluated by nonlinear static and dynamic analyses. The analysis results showed that compared with the system without friction dampers, the maximum roof displacement and the inter-story drift ratio were reduced by about 30% and 40%, respectively. After installation of the dampers about 70% of the earthquake input energy was dissipated by the dampers and the energy dissipated in the structural elements was reduced by about 50%. In comparison with the simplified methods of installation, the genetic algorithm provided more efficient solutions for seismic retrofit of the model structure.

Keywords: friction dampers, genetic algorithm, optimal design, RC buildings

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2466 Observational Learning in Ecotourism: An Investigation into Ecotourists' Environmentally Responsible Behavioral Intentions in South Korea

Authors: Benjamin Morse, Michaela Zint, Jennifer Carman

Abstract:

This study proposes a behavioral model in which ecotourists’ level of observational learning shapes their subsequent environmentally responsible behavioral intentions through ecotourism participation. Unlike past studies that have focused on individual attributes such as attitudes, locus of control, personal responsibility, knowledge, skills or effect, this present study explores select social attributes as potential antecedents to environmentally responsible behaviors. A total of 207 completed questionnaires were obtained from ecotourists in Korea and path analyses were conducted to explore the degree in which the hypothesized model directly and indirectly explained ecotourists’ environmentally responsible behavioral intentions. Results suggest that observational learning and its associated predictors (i.e., engagement, observation, reproduction and reinforcement) are key determinants of ecotourists environmentally responsible behavioral intentions. The application of observational learning proved to be informative, and has a number of implications for improving ecotourism programs. Our model also lays out a theoretical framework for future research.

Keywords: ecotourism, observational learning, environmentally responsible behavior, social learning theory

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2465 The Forensic Swing of Things: The Current Legal and Technical Challenges of IoT Forensics

Authors: Pantaleon Lutta, Mohamed Sedky, Mohamed Hassan

Abstract:

The inability of organizations to put in place management control measures for Internet of Things (IoT) complexities persists to be a risk concern. Policy makers have been left to scamper in finding measures to combat these security and privacy concerns. IoT forensics is a cumbersome process as there is no standardization of the IoT products, no or limited historical data are stored on the devices. This paper highlights why IoT forensics is a unique adventure and brought out the legal challenges encountered in the investigation process. A quadrant model is presented to study the conflicting aspects in IoT forensics. The model analyses the effectiveness of forensic investigation process versus the admissibility of the evidence integrity; taking into account the user privacy and the providers’ compliance with the laws and regulations. Our analysis concludes that a semi-automated forensic process using machine learning, could eliminate the human factor from the profiling and surveillance processes, and hence resolves the issues of data protection (privacy and confidentiality).

Keywords: cloud forensics, data protection Laws, GDPR, IoT forensics, machine Learning

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2464 Effects of Pipe Curvature and Internal Pressure on Stiffness and Buckling Phenomenon of Circular Thin-Walled Pipes

Authors: V. Polenta, S. D. Garvey, D. Chronopoulos, A. C. Long, H. P. Morvan

Abstract:

A parametric study on circular thin-walled pipes subjected to pure bending is performed. Both straight and curved pipes are considered. Ratio D/t, initial pipe curvature and internal pressure are the parameters varying in the analyses. The study is mainly FEA-based. It is found that negative curvatures (opposite to bending moment) considerably increase stiffness and buckling limit of the pipe when no internal pressure is acting and, similarly, positive curvatures decrease the stiffness and buckling limit. For internal pressurised pipes the effects of initial pipe curvature are less relevant. Results show that this phenomenon is in relationship with the cross-section deformation due to bending moment, which undergoes relevant ovalisation for no pressurised pipes and little ovalisation for pressurised pipes.

Keywords: buckling, curved pipes, internal pressure, ovalisation, pure bending, thin-walled pipes

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2463 Forage Production Area Development in Bangkok Metropolitan Region

Authors: Thipayasothorn Pastraporn, Phonpakdee Rachadakorn, Ponpo Sopar

Abstract:

Forage production area development in Bangkok Metropolitan Region with an Agriculture in the city concept. Food chain of city man reduced distance of the food, so the food chain was a good attempt to connect the city’s product with the changes in each area of city. This paper purposed (I) to study the problems of using forage production area development in Bangkok Metropolitan Region, (II) to propose guidelines of forage production area development in Bangkok Metropolitan Region. We collected the data by questionnaire which we got from the agriculture, marketing and city plan sector in Bangkok Metropolitan Region. We analyzed the questionnaire in the way of relationship and guidelines of forage production area development in Bangkok Metropolitan Region. Results from the analyses are that the role of forage area productive plan in Bangkok Metropolitan Region is important to the cities for adapting in changing way of the food transmission. It also enhanced benefits using from cities fringe. Moreover, it managed watercourse and reduced energy consumption in order to sustainable distribute the food into the cities. .

Keywords: city plan, forage production area, urban development, Bangkok Metropolitan Region

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2462 Psychosocial Predictors of Brand Loyalty in Pakistani Consumers

Authors: Muhammad Sulman, Tabinda Khurshid, Afsheen Masood

Abstract:

The current research focused on determining the factors that determine the brand loyalty in consumers. It was hypothesized that there are certain demographical features that lead the consumers to adhere more towards certain brands. Cross-sectional research design was used. The sample for the current research comprised of participants (N=500) from age group 16 to 55 years. The data was collected through self-constructed demographic questionnaire as well as from a self-constructed Brand Loyalty Questionnaire. Brand Loyalty Questionnaire was adapted after taking permission from researchers. A pilot study was conducted to chalk out all the ambiguities of the questionnaire. The final version was administered on 250 participants. The descriptive and inferential analyses were carried on through SPSS version 24.00 to explore the factors that determine Brand Loyalty. The findings revealed that there is a relationship between brand loyalty and brand loyalty demographics and certain factors emerged as significant predictors of brand loyalty in young and middle aged consumers. The research findings carry strong implications for organizational and consumer psychologists in particular and for professionals in marketing and policy making in general.

Keywords: consumers, consumer psychologists, marketing, organizational, policy making

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2461 Seismic Isolation of Existing Masonry Buildings: Recent Case Studies in Italy

Authors: Stefano Barone

Abstract:

Seismic retrofit of buildings through base isolation represents a consolidated protection strategy against earthquakes. It consists in decoupling the ground motion from that of the structure and introducing anti-seismic devices at the base of the building, characterized by high horizontal flexibility and medium/high dissipative capacity. This allows to protect structural elements and to limit damages to non-structural ones. For these reasons, full functionality is guaranteed after an earthquake event. Base isolation is applied extensively to both new and existing buildings. For the latter, it usually does not require any interruption of the structure use and occupants evacuation, a special advantage for strategic buildings such as schools, hospitals, and military buildings. This paper describes the application of seismic isolation to three existing masonry buildings in Italy: Villa “La Maddalena” in Macerata (Marche region), “Giacomo Matteotti” and “Plinio Il Giovane” school buildings in Perugia (Umbria region). The seismic hazard of the sites is characterized by a Peak Ground Acceleration (PGA) of 0.213g-0.287g for the Life Safety Limit State and between 0.271g-0.359g for the Collapse Limit State. All the buildings are isolated with a combination of free sliders type TETRON® CD with confined elastomeric disk and anti-seismic rubber isolators type ISOSISM® HDRB to reduce the eccentricity between the center of mass and stiffness, thus limiting torsional effects during a seismic event. The isolation systems are designed to lengthen the original period of vibration (i.e., without isolators) by at least three times and to guarantee medium/high levels of energy dissipation capacity (equivalent viscous damping between 12.5% and 16%). This allows the structures to resist 100% of the seismic design action. This article shows the performances of the supplied anti-seismic devices with particular attention to the experimental dynamic response. Finally, a special focus is given to the main site activities required to isolate a masonry building.

Keywords: retrofit, masonry buildings, seismic isolation, energy dissipation, anti-seismic devices

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2460 Seismic Evaluation of Multi-Plastic Hinge Design Approach on RC Shear Wall-Moment Frame Systems against Near-Field Earthquakes

Authors: Mohsen Tehranizadeh, Mahboobe Forghani

Abstract:

The impact of higher modes on the seismic response of dual structural system consist of concrete moment-resisting frame and with RC shear walls is investigated against near-field earthquakes in this paper. a 20 stories reinforced concrete shear wall-special moment frame structure is designed in accordance with ASCE7 requirements and The nonlinear model of the structure was performed on OpenSees platform. Nonlinear time history dynamic analysis with 3 near-field records are performed on them. In order to further understand the structural collapse behavior in the near field, the response of the structure at the moment of collapse especially the formation of plastic hinges is explored. The results revealed that the amplification of moment at top of the wall due to higher modes, the plastic hinge can form in the upper part of wall, even when designed and detailed for plastic hinging at the base only (according to ACI code).on the other hand, shear forces in excess of capacity design values can develop due to the contribution of the higher modes of vibration to dynamic response due to the near field can cause brittle shear or sliding failure modes. The past investigation on shear walls clearly shows the dual-hinge design concept is effective at reducing the effects of the second mode of response. An advantage of the concept is that, when combined with capacity design, it can result in relaxation of special reinforcing detailing in large portions of the wall. In this study, to investigate the implications of multi-design approach, 4 models with varies arrangement of hinge plastics at the base and height of the shear wall are considered. results base on time history analysis showed that the dual or multi plastic hinges approach can be useful in order to control the high moment and shear demand of higher mode effect.

Keywords: higher mode effect, Near-field earthquake, nonlinear time history analysis, multi plastic hinge design

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2459 Measurement of Operational and Environmental Performance of the Coal-Fired Power Plants in India by Using Data Envelopment Analysis

Authors: Vijay Kumar Bajpai, Sudhir Kumar Singh

Abstract:

In this study, the performance analyses of the twenty five coal-fired power plants (CFPPs) used for electricity generation are carried out through various data envelopment analysis (DEA) models. Three efficiency indices are defined and pursued. During the calculation of the operational performance, energy and non-energy variables are used as input, and net electricity produced is used as desired output. CO2 emitted to the environment is used as the undesired output in the computation of the pure environmental performance while in Model-3 CO2 emissions is considered as detrimental input in the calculation of operational and environmental performance. Empirical results show that most of the plants are operating in increasing returns to scale region and Mettur plant is efficient one with regards to energy use and environment. The result also indicates that the undesirable output effect is insignificant in the research sample. The present study will provide clues to plant operators towards raising the operational and environmental performance of CFPPs.

Keywords: coal fired power plants, environmental performance, data envelopment analysis, operational performance

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2458 Non-Standard Monetary Policy Measures and Their Consequences

Authors: Aleksandra Nocoń (Szunke)

Abstract:

The study is a review of the literature concerning the consequences of non-standard monetary policy, which are used by central banks during unconventional periods, threatening instability of the banking sector. In particular, the attention was paid to the effects of non-standard monetary policy tools for financial markets. However, the empirical evidence about their effects and real consequences for the financial markets are still not final. The main aim of the study is to survey the consequences of standard and non-standard monetary policy instruments, implemented during the global financial crisis in the United States, United Kingdom and Euroland, with particular attention to the results for the stabilization of global financial markets. The study analyses the consequences for short and long-term market interest rates, interbank interest rates and LIBOR-OIS spread. The study consists mainly of the empirical review, indicating the impact of the implementation of these tools for the financial markets. The following research methods were used in the study: literature studies, including domestic and foreign literature, cause and effect analysis and statistical analysis.

Keywords: asset purchase facility, consequences of monetary policy instruments, non-standard monetary policy, quantitative easing

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2457 Work-Home Interference and Emotional Exhaustion: The Role of Psychological Detachment, Relaxation and Technology-Assisted Supplemental Work

Authors: Nidhi S. Bisht

Abstract:

The study examines the role of work-home interference, on enhancing emotional exhaustion in the branch officers of private MFIs in India. Additionally, the moderating role of recovery experiences and technology-assisted supplemental work (TASW) were studied. With the increasing expectations to perform job related tasks at home, technology-assisted supplemental work (TASW) was hypothesized to positively moderate the relationship between work-home interference and emotional exhaustion. Further, it was expected that recovery experiences-psychological detachment, relaxation will help to recover and unwind from work and negatively moderate the relationship between work-home interference and emotional exhaustion. Results of SEM-analyses largely offered support for the hypotheses. These findings increase our insight in the processes leading to increased emotional exhaustion and suggest that employees can protect themselves from emotional exhaustion by keeping a tab on technology-assisted supplemental work and facilitating recovery experiences.

Keywords: emotional exhaustion, India, microfinance institutions (MFIs), work-home interference

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2456 A Dynamic Approach for Evaluating the Climate Change Risks on Building Performance

Authors: X. Lu, T. Lu, S. Javadi

Abstract:

A simple dynamic approach is presented for analyzing thermal and moisture dynamics of buildings, which is of particular relevance to understanding climate change impacts on buildings, including assessment of risks and applications of resilience strategies. With the goal to demonstrate the proposed modeling methodology, to verify the model, and to show that wooden materials provide a mechanism that can facilitate the reduction of moisture risks and be more resilient to global warming, a wooden church equipped with high precision measurement systems was taken as a test building for full-scale time-series measurements. Sensitivity analyses indicate a high degree of accuracy in the model prediction regarding the indoor environment. The model is then applied to a future projection of climate indoors aiming to identify significant environmental factors, the changing temperature and humidity, and effective response to the climate change impacts. The paper suggests that wooden building materials offer an effective and resilient response to anticipated future climate changes.

Keywords: dynamic model, forecast, climate change impact, wooden structure, buildings

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2455 Minimizing the Impact of Covariate Detection Limit in Logistic Regression

Authors: Shahadut Hossain, Jacek Wesolowski, Zahirul Hoque

Abstract:

In many epidemiological and environmental studies covariate measurements are subject to the detection limit. In most applications, covariate measurements are usually truncated from below which is known as left-truncation. Because the measuring device, which we use to measure the covariate, fails to detect values falling below the certain threshold. In regression analyses, it causes inflated bias and inaccurate mean squared error (MSE) to the estimators. This paper suggests a response-based regression calibration method to correct the deleterious impact introduced by the covariate detection limit in the estimators of the parameters of simple logistic regression model. Compared to the maximum likelihood method, the proposed method is computationally simpler, and hence easier to implement. It is robust to the violation of distributional assumption about the covariate of interest. In producing correct inference, the performance of the proposed method compared to the other competing methods has been investigated through extensive simulations. A real-life application of the method is also shown using data from a population-based case-control study of non-Hodgkin lymphoma.

Keywords: environmental exposure, detection limit, left truncation, bias, ad-hoc substitution

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2454 Failure Analysis of a Hydrocarbon Carrying/Piping System

Authors: Esteban Morales Murillo, Ephraim Mokgothu

Abstract:

This paper presents the findings of a study conducted to investigate the wall thinning in a piping system carrying a mix of hydrocarbons in a petrochemical plant. A detailed investigation including optical inspection and several characterisation techniques such as optical microscopy, SEM/EDX, and XRF/C-S analyses was conducted. The examinations revealed that the wall thinning in the piping system was a result of high-temperature H2/H2S corrosion caused by a susceptible material for this mechanism and operating parameters and effluent concentrations beyond the prescribed limits. The sulfide layers found to testify to the large amounts of H2S that led to material degradation. Deposit analysis revealed that it consisted primarily of carbon, oxygen, iron, chromium and sulfur. Metallographic examinations revealed that the attack initiated from the internal surface and that spheroidization of carbides did occur. The article discusses in detail the contribution failure factors on the Couper-Gorman H2/H2S curves to draw conclusions. Recommendations based on the above findings are also discussed.

Keywords: corrosion, Couper-Gorman, high-temperature corrosion, sulfidation, wall thinning, piping system

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2453 Sensitivity Analysis of Interference of Localised Corrosion on Bending Capacity of a Corroded RC Beam

Authors: Mohammad Mahdi Kioumarsi

Abstract:

In this paper, using the response surface method (RSM), tornado diagram method and non-linear finite element analysis, the effect of four parameters on residual bending capacity of a corroded RC beam was investigated. The parameters considered are amount of localised cross section reduction, ratio of pit distance on adjacent bars to rebar distance, concrete compressive strength, and rebar tensile strength. The focus is on the influence on the bending ultimate limit state. Based on the obtained results, the effects of the ratio of pit distance to rebar distance (Lp⁄Lr) and the ratio of the localised cross section reduction to the original area of the rebar (Apit⁄A0) were found significant. The interference of localised corrosion on adjacent reinforcement bars reduces the bending capacity of under-reinforced concrete beam. Using the sensitivity analysis could lead to recognize uncertainty parameters, which have the most influences on the performance of the structure.

Keywords: localised corrosion, concrete beam, sensitivity analyses, ultimate capacity

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2452 Naturally Occurring Abietic Acid for Liquid Crystalline Epoxy Curing Agents

Authors: Rasha A.Ibrahim El-Ghazawy, Ashraf M. El-Saeed, Heusin El-Shafey, M. Abdel-Raheim, Maher A. El-Sockary

Abstract:

Two thermotropic liquid crystalline curing agents based on abietic acid with different mesogens (LCC1 and LCC2) were synthesized for producing thermally stable liquid crystal networks suitable for high performance epoxy coatings. Differential scanning calorimetry (DSC) and polarized optical microscope (POM) was used to identify the liquid crystal phase transformation temperatures and texture, respectively. POM micro graphs for both LCCs revealing cholesteric texture. A multifunctional epoxy resin with two abietic acid moieties was also synthesized. Dynamic mechanical (DMA) and thermogravimetric (TGA) analyses show that the fully bio-based cured epoxies by either LCCs possess high glass transition temperature (Tg), high modulus (G`) and improved thermal stability. The chemical structure of the synthesized LCCs and epoxy resin was investigated through FTIR and 1HNMR spectroscopic techniques.

Keywords: abietic acid, dynamic mechanical analysis, epoxy resin, liquid crystal, thermo gravimetric analysis

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2451 Theory of Planned Behavior Predicts Graduation Intentions of College and University Students with and without Learning Disabilities / Attention Deficit Hyperactivity Disorder in Canada and Israel

Authors: Catherine S. Fichten, Tali Heiman, Mary Jorgensen, Mai Nhu Nguyen, Rhonda Amsel, Dorit Olenik-Shemesh

Abstract:

The study examined Canadian and Israeli students' perceptions related to their intention to graduate from their program of studies. Canada and Israel are dissimilar in many ways that affect education, including language and alphabet. In addition, the postsecondary education systems differ. For example, in some parts of Canada (e.g., in Quebec, Canada’s 2nd largest province), students matriculate after 11 years of high school; in Israel, this typically occurs after 12 years. In addition, Quebec students attend two compulsory years of junior college before enrolling in a three-year university Bachelor program; in Israel students enroll in a three-year Bachelor program directly after matriculation. In addition, Israeli students typically enroll in the army shortly after high school graduation; in Canada, this is not the case. What the two countries do have in common is concern about the success of postsecondary students with disabilities. The present study was based on Ajzen’s Theory of Planned Behavior (TPB); the model suggests that behavior is influenced by Intention to carry it out. This, in turn, is predicted by the following correlated variables: Perceived Behavioral Control (i.e., ease or difficulty enacting the behavior - in this case graduation), Subjective Norms (i.e., perceived social/peer pressure from individuals important in the student’s life), and Attitude (i.e., positive or negative evaluation of graduation). A questionnaire was developed to test the TPB in previous Canadian studies and administered to 845 Canadian college students (755 nondisabled, 90 with LD/ADHD) who had completed at least one semester of studies) and to 660 Israeli university students enrolled in a Bachelor’s program (537 nondisabled, 123 with LD/ADHD). Because Israeli students were older than Canadian students we covaried age in SPSS-based ANOVA comparisons and included it in regression equations. Because females typically have better academic outcomes than males, gender was included in all analyses. ANOVA results indicate only a significant gender effect for Intention to graduate, with females having higher scores. Four stepwise regressions were conducted, with Intention to graduate as the predicted variable, and Gender and the three TPB predictors as independent variables (separate analyses for Israeli and Canadian samples with and without LD/ADHD). Results show that for samples with LD/ADHD, although Gender and Age were not significant predictors, the TPB predictors were, with all three TPB predictors being significant for the Canadian sample (i.e., Perceived Behavioral Control, Subjective Norms, Attitude, R2=.595), and two of the three (i.e., Perceived Behavioral Control, Subjective Norms) for the Israeli sample (R2=.528). For nondisabled students, the results for both countries show that all three TPB predictors were significant along with Gender: R2=.443 for Canada and R2=.332 for Israel; age was not significant. Our findings show that despite vast differences between our Canadian and Israeli samples, Intention to graduate was related to the three TPB predictors. This suggests that our TPB measure is valid for diverse samples and countries that it can be used as a quick, inexpensive way to predict graduation rates, and that strengthening the three predictor variables may result in higher graduation rates.

Keywords: disability, higher education, students, theory of planned behavior

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2450 Assessing Effectiveness of Manager-Subordinate Relationships at Workplace

Authors: Anant Sagar, Manisha Rana, Surabhi Singhal

Abstract:

This study was aimed at analysing the effectiveness of manager-subordinate relationship and the different factors contributing to its effectiveness in a mid-sized IT organization. To define effectiveness in context of a manager-subordinate relationship, a model was framed which analyses personal and professional need fulfilment of subordinates. On basis of this need satisfaction based effectiveness model, relationships are categorized into four types anchored on two scales; Personal Need Satisfaction and Professional Need Satisfaction. These spatial effectiveness scores of a managerial relationship are further mapped with the relationship style of the manager to identify relationship styles which are associated with different effectiveness levels. The relationship style is analysed by using Impact Message Inventory-Circumplex (IMI-C). The results show that managerial relationship’s effectiveness is contingent on manager’s affiliation scores, subordinate’s previous work experience and the ability of managers to influence the personal and professional needs of employees through organizational policies. The findings reflect that effectiveness of manager-subordinate relationship increased in a friendly workplace where managers were adequately empowered to acknowledge employee needs.

Keywords: relationship effectiveness, need fulfilment, managerial style, impact message inventory-circumplex

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2449 Analysis of Trends in Equity of Maternal Health Care in South India

Authors: Anushree S. Panikkassery

Abstract:

The paper analyses the pattern and trend of maternal health care in south Indian states. It studies the interstate disparities in terms of maternal health care. It also compares the trends in terms of achieving the target of sustainable development Goal is related to maternal health. The maternal health care (MHC) development is one of the key indicators for the development of health sector in the country and assumes significance from the socioeconomic and developmental perspectives. Maternal health care mainly consists of composite care during pregnancy, child birth as well as postpartum period. Antenatal care, identification, referral and management of high risk pregnancies, safe and healthy child birth and early postnatal care are some of the important issues pertaining to maternal health. Data is collected from national family health survey 1992-93, 1998-99, 2005-06, and 2015-16. A concentration index is used to study the disparities in equity of maternal health among south Indian states. The study shows that there has been an improvement in maternal health care in south Indian states with Kerala topping among the states. But there exist disparities among the south Indian states.

Keywords: antenatal care, disparities, equity, maternal health

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2448 Long-Term Mechanical and Structural Properties of Metakaolin-Based Geopolymers

Authors: Lenka Matulova

Abstract:

Geopolymers are alumosilicate materials that have long been studied. Despite this fact, little is known about the long-term stability of geopolymer mechanical and structural properties, so crucial for their successful industrial application. To improve understanding, we investigated the effect of four different types of environments on the mechanical and structural properties of a metakaolin-based geopolymer (MK GP). The MK GP samples were stored in laboratory conditions (control samples), in water at 20 °C, in water at 80 °C, and outside exposed to the weather. Compressive and tensile strengths were measured after 28, 56, 90, and 360 days. In parallel, structural properties were analyzed using XRD, SEM, and mercury intrusion porosimetry. Whereas the mechanical properties of the samples in laboratory conditions and in 20 °C water were stable, the mechanical properties of the outdoor samples and the samples 80 °C water decreased noticeably after 360 days. Structural analyses were focused on changes in sample microstructure (developing microcrack network, porosity) and identifying zeolites, the presence of which would indicate detrimental processes in the structure that can change it from amorphous to crystalline. No zeolites were found during the 360-day period in MK GP samples, but the reduction in mechanical properties coincided with a developing network of microcracks and changes in pore size distribution.

Keywords: geopolymer, long-term properties, mechanical properties, metakaolin, structural properties

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2447 Comparative Analysis of Integrated and Non-Integrated Fish Farming in Ogun State, Nigeria

Authors: B. G. Abiona

Abstract:

This study compared profitability analysis of integrated and non-integrated fish farming in Ogun State, Nigeria. Primary data were collected using interview guide. Random sampling techniques was used to select 133 non-integrated fish farmers (NIFF) and 216 integrated fish farmers (IFF) (n = 349) from the study area. Data were analyzed using Chi-square, T-test and Pearson Product moment correlation. Results showed that 92.5% of NIFF was male compared to IFF (90.7%). Also, 96.8% of IFF and 79.7% of NIFF were married. The mean ages of sampled farmers were 44 years (NIFF) and 46 years (IFF) while the mean fish farming experiences were 4 years (NIFF) and 5 years (IFF). Also, the average net profit per year of integrated fish farmers was ₦162,550 compared to NIFF (₦61,638). The chi-square analyses showed that knowledge of fish farming had significant relationship with respondents sex (χ2 = 9.44, df = 2, p < 0.05), age (r = 0.20, p< 0.05) and farming experience (r = p = 0.05). Significant differences exist between integrated and non-integrated fish farming, considering their knowledge of fish farming (t = 21.5, χ = 43.01, p < 0.05). The study concluded that IFF are more profitable compared to NIFF. It was recommended that private investors and NGOs should sponsor short training and courses which will enhance efficiency of fish farming to boost productivity among fish farmers.

Keywords: profitability analysis, farms, integration

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2446 Improvement of Oran Sebkha Soil by Dredged Sediments from Chorfa Dam in Algeria

Authors: Z. Aloui-Labiod, H. Trouzine, M. S. Ghembaza

Abstract:

Geotechnical properties of dredged sediment from Chorfa dam in Algeria and their mixtures (5%, 10%, 15%, 20%, and 25%)with bentonite were investigated through with bentonite were investigated through a series of laboratory experimental tests in order to investigate possibilities of their usage as a barrier against the spread out of the Sebkha of Oran in the northwest of Algeria. Grain size and Atterberg limits tests, chemical and mineral analyses, and compaction, vertical swelling, and horizontal and vertical permeability tests were performed on the soils and their mixtures using tap water and the salty Sebkha water. The results indicate that the bentonite specimens remolded and inundated with Sebkha salty water have less swell potential than those prepared with tap water. The addition of bentonite to Chorfa sediment increases the density, limit liquid, specific surface, and swell potential of the mixtures. Compaction tests show a decrease in the optimum moisture and an increase in maximum dry densities as the bentonite content increases. The horizontal and vertical permeabilities decrease relatively with the addition of bentonite.

Keywords: dredged sediment, bentonite, salty water, barrier

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2445 The Role of Social Parameters in the Choice of Address Forms Used in Kinship Domain in Punjab, Pakistan

Authors: Ana Ramsha, Samrah Hidayat

Abstract:

This study examines the role of social parameters in the choice of address forms used in kinship domain in Punjab, Pakistan. The study targeted 140 respondents in order to test the impact of social factors along with the regional differences in the choices of address forms in kinship domain. Statistical analyses are done by applying t-test for gender in relation to choices of address forms and ANOVA for age, income, education and social class. The study finds out that there is a strong connection of different social parameters not only with language use and practice but also in choices and use of address forms, especially in kinship relationships. Moreover, it is highlighted that gender does not influence in the choices of address forms, even the participants belonging to young and middle categories show no significant difference with regard to the choices of address form despite the fact that all the factors and parameters exert influence on the choices of address forms. Hence address forms as being one of the major traits of language and society is affected by all the social factors around and regional differences are also most important as they give identity and ethnicity to the society.

Keywords: address forms, kinship, social parameters, linguistics

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2444 Influence of Cure Degree in GO and CNT-Epoxy Nanocomposites

Authors: Marina Borgert Moraes, Wesley Francisco, Filipe Vargas, Gilmar Patrocínio Thim

Abstract:

In recent years, carbon nanotubes (CNT) and graphene oxide (GO), especially the functionalized ones, have been added to epoxy resin in order to increase the mechanical, electrical and thermal properties of nanocomposites. However, it's still unknown how the presence of these nanoparticles influences the curing process and the final mechanical properties as well. In this work, kinetic and mechanical properties of the nanocomposites were analyzed, where the kinetic process was followed by DSC and the mechanical properties by DMA. Initially, CNT was annealed at high temperature (1800 °C) under vacuum atmosphere, followed by a chemical treatment using acids and ethylenediamine. GO was synthesized through chemical route, washed clean, dried and ground to #200. The presence of functional groups on CNT and GO surface was confirmed by XPS spectra and FT-IR. Then, epoxy resin, nanoparticles and acetone were mixed by sonication in order to obtain the composites. DSC analyses were performed on samples with different curing cycles (1h 80°C + 2h 120°C; 3h 80°C + 2h 120°C; 5h 80°C) and samples with different times at constant temperature (120°C). Results showed that the kinetic process and the mechanical strength are very dependent on the presence of graphene and functionalized-CNT in the nanocomposites.

Keywords: carbon nanotube, epoxy resin, Graphene oxide, nanocomposite

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