Search results for: working pairs.
3038 Investigation on Ultrahigh Heat Flux of Nanoporous Membrane Evaporation Using Dimensionless Lattice Boltzmann Method
Authors: W. H. Zheng, J. Li, F. J. Hong
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Thin liquid film evaporation in ultrathin nanoporous membranes, which reduce the viscous resistance while still maintaining high capillary pressure and efficient liquid delivery, is a promising thermal management approach for high-power electronic devices cooling. Given the challenges and technical limitations of experimental studies for accurate interface temperature sensing, complex manufacturing process, and short duration of membranes, a dimensionless lattice Boltzmann method capable of restoring thermophysical properties of working fluid is particularly derived. The evaporation of R134a to its pure vapour ambient in nanoporous membranes with the pore diameter of 80nm, thickness of 472nm, and three porosities of 0.25, 0.33 and 0.5 are numerically simulated. The numerical results indicate that the highest heat transfer coefficient is about 1740kW/m²·K; the highest heat flux is about 1.49kW/cm² with only about the wall superheat of 8.59K in the case of porosity equals to 0.5. The dissipated heat flux scaled with porosity because of the increasing effective evaporative area. Additionally, the self-regulation of the shape and curvature of the meniscus under different operating conditions is also observed. This work shows a promising approach to forecast the membrane performance for different geometry and working fluids.Keywords: high heat flux, ultrathin nanoporous membrane, thin film evaporation, lattice Boltzmann method
Procedia PDF Downloads 1633037 Generalized Approach to Linear Data Transformation
Authors: Abhijith Asok
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This paper presents a generalized approach for the simple linear data transformation, Y=bX, through an integration of multidimensional coordinate geometry, vector space theory and polygonal geometry. The scaling is performed by adding an additional ’Dummy Dimension’ to the n-dimensional data, which helps plot two dimensional component-wise straight lines on pairs of dimensions. The end result is a set of scaled extensions of observations in any of the 2n spatial divisions, where n is the total number of applicable dimensions/dataset variables, created by shifting the n-dimensional plane along the ’Dummy Axis’. The derived scaling factor was found to be dependent on the coordinates of the common point of origin for diverging straight lines and the plane of extension, chosen on and perpendicular to the ’Dummy Axis’, respectively. This result indicates the geometrical interpretation of a linear data transformation and hence, opportunities for a more informed choice of the factor ’b’, based on a better choice of these coordinate values. The paper follows on to identify the effect of this transformation on certain popular distance metrics, wherein for many, the distance metric retained the same scaling factor as that of the features.Keywords: data transformation, dummy dimension, linear transformation, scaling
Procedia PDF Downloads 2993036 Comparison of Carcass Weight of Pure and Mixed Races Namebar 30-Day Squabs
Authors: Sepehr Moradi, Mehdi Asadi Rad
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The aim of this study is to evaluate and compare carcass weight of pure and mixed races Namebar 30-day pigeons to investigate about their sex, race, and some auxiliary variables. In this paper, 68 pieces of pigeons as 34 male and female pairs with equal age are studied randomly. A natural incubation was done from each pair. All produced chickens were slaughtered at 30 days age after 12 hours hunger. Then their carcasses were weighted by a scale with one gram precision. A covariance analysis was used since there were many auxiliary variables and unequal observations. SAS software was used for statistical analysis. Mean weight of carcass in pure race (Namebar-Namebar) with 8 records, 219.5±61.3 gr and mixed races of Kabood-Namebar, Parvazy-Namebar, Tizpar-Namebar, Namebar-Kabood, Namebar-Tizpar, and Namebar-Parvazy with 8, 10, 8, 12, 12, and 10 records were 369.9±54.6, 338.3±52.7, 224.5±73.6, 142.3±67.8, 155.6±56.2, and 170.2±55 gr, respectively.. Difference carcass weight of 30-day of Namebar-Namebar race with Namebar-Kabood, Namebar-Parvazy, Namebar-Tizpar, Parvazy-Namebar and Tizpar-Namebar mixed races was not significant, and was significant in level 5% with Kabood- Namebar (P < 0.05). Effect of sex and age were also significant in 1% level (P < 0.01), but mutual effect of sex and race was not significant. The results showed that most and least weights of carcass belonged to Kabood-Namebar and Namebar-Kabood.Keywords: squab, Namebar race, 30-day carcass weight, pigeons
Procedia PDF Downloads 1803035 Model Organic Ranikin Cycle Power Plant for Waste Heat Recovery in Olkaria-I Geothermal Power Plant
Authors: Haile Araya Nigusse, Hiram M. Ndiritu, Robert Kiplimo
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Energy consumption is an indispensable component for the continued development of the human population. The global energy demand increases with development and population rise. The increase in energy demand, high cost of fossil fuels and the link between energy utilization and environmental impacts have resulted in the need for a sustainable approach to the utilization of the low grade energy resources. The Organic Rankine Cycle (ORC) power plant is an advantageous technology that can be applied in generation of power from low temperature brine of geothermal reservoirs. The power plant utilizes a low boiling organic working fluid such as a refrigerant or a hydrocarbon. Researches indicated that the performance of ORC power plant is highly dependent upon factors such as proper organic working fluid selection, types of heat exchangers (condenser and evaporator) and turbine used. Despite a high pressure drop, shell-tube heat exchangers have satisfactory performance for ORC power plants. This study involved the design, fabrication and performance assessment of the components of a model Organic Rankine Cycle power plant to utilize the low grade geothermal brine. Two shell and tube heat exchangers (evaporator and condenser) and a single stage impulse turbine have been designed, fabricated and the performance assessment of each component has been conducted. Pentane was used as a working fluid and hot water simulating the geothermal brine. The results of the experiment indicated that the increase in mass flow rate of hot water by 0.08 kg/s caused a rise in overall heat transfer coefficient of the evaporator by 17.33% and the heat transferred was increased by 6.74%. In the condenser, the increase of cooling water flow rate from 0.15 kg/s to 0.35 kg/s increased the overall heat transfer coefficient by 1.21% and heat transferred was increased by 4.26%. The shaft speed varied from 1585 to 4590 rpm as inlet pressure was varied from 0.5 to 5.0 bar and power generated was varying from 4.34 to 14.46W. The results of the experiments indicated that the performance of each component of the model Organic Rankine Cycle power plant operating at low temperature heat resources was satisfactory.Keywords: brine, heat exchanger, ORC, turbine
Procedia PDF Downloads 6513034 Compact Dual-Band Bandpass Filter Based on Quarter Wavelength Stepped Impedance Resonators
Authors: Yu-Fu Chen, Zih-Jyun Dai, Chen-Te Chiu, Shiue-Chen Chiou, Yung-Wei Chen, Yu-Ming Lin, Kuan-Yu Chen, Hung-Wei Wu, Hsin-Ying Lee, Yan-Kuin Su, Shoou-Jinn Chang
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This paper presents a compact dual-band bandpass filter that involves using the quarter wavelength stepped impedance resonators (SIRs) for achieving simultaneously compact circuit size and good dual-band performance. The filter is designed at 2.4 / 3.5 GHz and constructed by two pairs of quarter wavelength SIRs and source-load lines. By properly tuning the impedance ratio, length ratio and radius of via hole of the SIRs, dual-passbands performance can be easily determined. To improve the passband selectivity, the use of source-load lines is to increase coupling energy between the resonators. The filter is showing simple configuration, effective design method and small circuit size. The measured results are in good agreement with the simulation results.Keywords: dual-band, bandpass filter, stepped impedance resonators, SIR
Procedia PDF Downloads 5173033 Domain Adaptive Dense Retrieval with Query Generation
Authors: Rui Yin, Haojie Wang, Xun Li
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Recently, mainstream dense retrieval methods have obtained state-of-the-art results on some datasets and tasks. However, they require large amounts of training data, which is not available in most domains. The severe performance degradation of dense retrievers on new data domains has limited the use of dense retrieval methods to only a few domains with large training datasets. In this paper, we propose an unsupervised domain-adaptive approach based on query generation. First, a generative model is used to generate relevant queries for each passage in the target corpus, and then, the generated queries are used for mining negative passages. Finally, the query-passage pairs are labeled with a cross-encoder and used to train a domain-adapted dense retriever. We also explore contrastive learning as a method for training domain-adapted dense retrievers and show that it leads to strong performance in various retrieval settings. Experiments show that our approach is more robust than previous methods in target domains that require less unlabeled data.Keywords: dense retrieval, query generation, contrastive learning, unsupervised training
Procedia PDF Downloads 1053032 Semi-Analytic Method in Fast Evaluation of Thermal Management Solution in Energy Storage System
Authors: Ya Lv
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This article presents the application of the semi-analytic method (SAM) in the thermal management solution (TMS) of the energy storage system (ESS). The TMS studied in this work is fluid cooling. In fluid cooling, both effective heat conduction and heat convection are indispensable due to the heat transfer from solid to fluid. Correspondingly, an efficient TMS requires a design investigation of the following parameters: fluid inlet temperature, ESS initial temperature, fluid flow rate, working c rate, continuous working time, and materials properties. Their variation induces a change of thermal performance in the battery module, which is usually evaluated by numerical simulation. Compared to complicated computation resources and long computation time in simulation, the SAM is developed in this article to predict the thermal influence within a few seconds. In SAM, a fast prediction model is reckoned by combining numerical simulation with theoretical/empirical equations. The SAM can explore the thermal effect of boundary parameters in both steady-state and transient heat transfer scenarios within a short time. Therefore, the SAM developed in this work can simplify the design cycle of TMS and inspire more possibilities in TMS design.Keywords: semi-analytic method, fast prediction model, thermal influence of boundary parameters, energy storage system
Procedia PDF Downloads 1553031 A Constitutional Theory of the American Presidency
Authors: Elvin Lim
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This article integrates the debate about presidential powers with the debate about federalism, arguing that there are two ways of exercising presidential powers, one working in tandem with expanding federal powers, and the other working against it. Alexander Hamilton and Thomas Jefferson—the former a Federalist and the latter echoing the views of many Anti-Federalists—disagreed not only on the constitutional basis of prerogative, but also on the ends for which it should be deployed. This tension has always existed in American politics, and is reproduced today. Modern Democrats and Republicans both want a strong executive, but the Democrats who want a strong executive to pass legislation to expand the reach of the federal government; naturally, they must rely on an equally empowered Congress to do so. Republicans generally do not want an intrusive federal government, which is why their defense of a strong presidency does not come alongside a call for a strong Congress. This distinction cannot be explained without recourse to foundational yet opposing views about the appropriate role of federal power. When we bring federalism back in, we see that there are indeed two presidencies; one neo-Federalist, in favor of moderate presidential prerogative alongside a robust Congress directed collectively to a national state-building agenda and expanding the federal prerogative; another, neo-Anti-Federalist, in favor of expansive presidential prerogative and an ideologically sympathetic Congress equally suspicious of federal power to retard or roll back national state-building in favour of states rights.Keywords: US presidency, federalism, prerogative, anti-federalism
Procedia PDF Downloads 1193030 Nurses' Knowledge and Attitudes toward the Use of Physical Restraints
Authors: Fatema Salman, Ridha Hammam, Fatima Khairallah, Fatima Aradi, Nafeesa Abdulla, Mohammed Alsafar
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Purpose: This study aims at measuring the extent of nurses’ knowledge and attitudes toward the use of physical restraints in different hospital wards at Salmaniya Medical Complex (SMC). Background: The habitual use of physical restraint is a widespread practice among nurses working in the clinical settings. Restraints inflict many deleterious consequences on patients physically and psychologically which in turn increases their morbidity and mortality risk and jeopardizes care quality. Nurses’ knowledge and attitudes toward physical restraints are crucial determinants of the persistence of this practice. Literature review: the evidence of lack of knowledge among nurses regarding the use of physical restraints is overwhelming in various clinical settings, especially in two main areas which are the negative consequences and the available alternatives to physical restraints. Studies explored nurses’ attitudes toward physical restraints yielded inconsistent findings. Equally comparable, some studies found that nurses hold positive attitudes toward the use of physical restraints while some others reported just the opposite. Methods: Self-administered knowledge and attitudes scales to 106 nurses working in the SMC. Findings: nurses hold the moderate level of knowledge about restraints (M=58%) with weak negative attitudes (M = -20%) toward using it. Significant moderately-strong negative correlation (r= -0.57, r2= 0.32, p= 0.000) was uncovered between nurses knowledge and their attitudes which provided an empirical explanation of this phenomenon (use of physical restraints). Recommendations: Induction of awareness program that especially focuses on the negative consequences and encourages the use of alternatives is an evident need. This effort necessarily should be adjoined with policy and procedure adjustments.Keywords: attitudes, knowledge, nurses, restraints
Procedia PDF Downloads 3183029 Healthcare Providers’ Perception Towards Utilization of Health Information Applications and Its Associated Factors in Healthcare Delivery in Health Facilities in Cape Coast Metropolis, Ghana
Authors: Richard Okyere Boadu, Godwin Adzakpah, Nathan Kumasenu Mensah, Kwame Adu Okyere Boadu, Jonathan Kissi, Christiana Dziyaba, Rosemary Bermaa Abrefa
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Information and communication technology (ICT) has significantly advanced global healthcare, with electronic health (e-Health) applications improving health records and delivery. These innovations, including electronic health records, strengthen healthcare systems. The study investigates healthcare professionals' perceptions of health information applications and their associated factors in the Cape Coast Metropolis of Ghana's health facilities. Methods: We used a descriptive cross-sectional study design to collect data from 632 healthcare professionals (HCPs), in the three purposively selected health facilities in the Cape Coast municipality of Ghana in July 2022. Shapiro-Wilk test was used to check the normality of dependent variables. Descriptive statistics were used to report means with corresponding standard deviations for continuous variables. Proportions were also reported for categorical variables. Bivariate regression analysis was conducted to determine the factors influencing the Benefits of Information Technology (BoIT); Barriers to Information Technology Use (BITU); and Motives of Information Technology Use (MoITU) in healthcare delivery. Stata SE version 15 was used for the analysis. A p-value of less than 0.05 served as the basis for considering a statistically significant accepting hypothesis. Results: Healthcare professionals (HCPs) generally perceived moderate benefits (Mean score (M)=5.67) from information technology (IT) in healthcare. However, they slightly agreed that barriers like insufficient computers (M=5.11), frequent system downtime (M=5.09), low system performance (M=5.04), and inadequate staff training (M=4.88) hindered IT utilization. Respondents slightly agreed that training (M=5.56), technical support (M=5.46), and changes in work procedures (M=5.10) motivated their IT use. Bivariate regression analysis revealed significant influences of education, working experience, healthcare profession, and IT training on attitudes towards IT utilization in healthcare delivery (BoIT, BITU, and MoITU). Additionally, the age of healthcare providers, education, and working experience significantly influenced BITU. Ultimately, age, education, working experience, healthcare profession, and IT training significantly influenced MoITU in healthcare delivery. Conclusions: Healthcare professionals acknowledge moderate benefits of IT in healthcare but encounter barriers like inadequate resources and training. Motives for IT use include staff training and support. Bivariate regression analysis shows education, working experience, profession, and IT training significantly influence attitudes toward IT adoption. Targeted interventions and policies can enhance IT utilization in the Cape Coast Metropolis, Ghana.Keywords: health information application, utilization of information application, information technology use, healthcare
Procedia PDF Downloads 673028 Visual Thing Recognition with Binary Scale-Invariant Feature Transform and Support Vector Machine Classifiers Using Color Information
Authors: Wei-Jong Yang, Wei-Hau Du, Pau-Choo Chang, Jar-Ferr Yang, Pi-Hsia Hung
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The demands of smart visual thing recognition in various devices have been increased rapidly for daily smart production, living and learning systems in recent years. This paper proposed a visual thing recognition system, which combines binary scale-invariant feature transform (SIFT), bag of words model (BoW), and support vector machine (SVM) by using color information. Since the traditional SIFT features and SVM classifiers only use the gray information, color information is still an important feature for visual thing recognition. With color-based SIFT features and SVM, we can discard unreliable matching pairs and increase the robustness of matching tasks. The experimental results show that the proposed object recognition system with color-assistant SIFT SVM classifier achieves higher recognition rate than that with the traditional gray SIFT and SVM classification in various situations.Keywords: color moments, visual thing recognition system, SIFT, color SIFT
Procedia PDF Downloads 4713027 The Actoprotective Efficiency of Pyrimidine Derivatives
Authors: Nail Nazarov, Vladimir Zobov, Alexandra Vyshtakalyuk, Vyacheslav Semenov, Irina Galyametdinova, Vladimir Reznik
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There have been studied effects of xymedon and six new pyrimidine derivatives, that are close and distant analogs of xymedon, on rats' working capacity in the test 'swimming to failure'. It has been shown that a single administration of the studied compounds did not have a statistically significant effect in the test. In the conditions of multiple intraperitoneal administration of the studied pyrimidine derivatives, the compound L-ascorbate, 1-(2-hydroxyethyl)-4.6-dimethyl-1.2-dihydropyrimidine-2-one had the lowest toxicity and the most pronounced actoprotective effect. Introduction in the dose of 20 mg/kg caused a statistically significant increase 440 % in the duration of swimming of rats on the 14th day of the experiment compared with the control group. Multiple administration of the compound in the conditions of physical load did not affect leucopoiesis but stimulates erythropoiesis resulting in an increase in the number of erythrocytes and a hemoglobin level. The substance introduction under mixed exhausting loads prevented such changes of blood biochemical parameters as reduction of glucose, increased of urea and lactic acid levels, what indicates improvement in the animals' tolerability of loads and an anti-catabolic effect of the compound. Absence of hepato and cardiotoxic effects of the substance has been shown. This work was performed with the financial support of Russian Science Foundation (grant № 14-50-00014).Keywords: actoprotectors, physical working capacity, pyrimidine derivatives, xymedon
Procedia PDF Downloads 2933026 Studying in the Outback: A Hermeneutic Phenomenological Study of the Lived Experience of Women in Regional, Rural and Remote Areas Studying Nursing Online
Authors: Keden Montgomery, Kathie Ardzejewska, Alison Casey, Rosemarie Hogan
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Research was undertaken to explore the question “what is known about the experiences of regional, rural and remote Australian women undertaking a Bachelor of Nursing program delivered online?”. The findings will support future research aimed at improving the retention and completion rates of women studying nursing in regional, rural and remote areas. There is a critical shortage of nurses working in regional, rural and remote (RRR) Australia. It is well supported that this shortage of nurses is most likely to be addressed by nursing students who are completing their studies in RRR areas. Despite this, students from RRR Australia remain an equity group and experience poorer outcomes than their metropolitan counterparts. Completion rates for RRR students who enrol in tertiary education courses are much less than students from metropolitan areas. In addition to this, RRR students are less likely than students from metropolitan areas to gain a tertiary level qualification at all, and even less likely to gain a Bachelor level degree which is required for Registered Nurses. Supporting students to remain in regional, rural and remote areas while they study reduces the need for students to relocate to metropolitan areas and to continue living and working in RRR areas after graduation. This research holds implications for workforce shortages internationally.Keywords: nurse education, online education, regional, rural, remote, workforce
Procedia PDF Downloads 883025 A Randomized Controlled Trial of the Effects of Meditation Awareness Training (Mat) on Work-Related Stress and Job Performance
Authors: Edo Shonin, William Van Gordon, Mark D. Griffiths
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Due to its potential to concurrently improve Work-Related Wellbeing (WRW) and job performance; occupational stakeholders are becoming increasingly interested in meditation. Despite this, there is a scarcity of methodologically robust research examining the utility of meditation within occupational contexts. This study conducted the first randomized controlled trial to assess the effects of meditation on outcomes relating to both WRW and job performance. Office-based middle-hierarchy managers (n=152) were allocated to either an eight-week meditation intervention (Meditation Awareness Training: MAT) or an active control intervention. MAT participants demonstrated significant improvements (with strong effect-sizes) over control-group participants in levels of work-related stress, job satisfaction, psychological distress, and employer-rated job performance. It is concluded that MAT appears to be effective for improving both WRW and job performance in middle-hierarchy managers. There are a number of novel implications: (i) meditation can effectuate a perceptual shift in how employees experience their work and psychological environment and may thus constitute a cost-effective WRW intervention, (ii) meditation-based (i.e., present-moment-focused) working styles may be more effective than goal-based (i.e., future-orientated) working styles, and (iii) meditation may reduce the separation made by employees between their own interests and those of the organizations they work for.Keywords: work-related stress, workplace wellbeing, occupational stress, job performance, meditation awareness training, mindfulness
Procedia PDF Downloads 3183024 Experimental Investigation of Heat Transfer on Vertical Two-Phased Closed Thermosyphon
Authors: M. Hadi Kusuma, Nandy Putra, Anhar Riza Antariksawan, Ficky Augusta Imawan
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Heat pipe is considered to be applied as a passive system to remove residual heat that generated from reactor core when incident occur or from spent fuel storage pool. The objectives are to characterized the heat transfer phenomena, performance of heat pipe, and as a model for large heat pipe will be applied as passive cooling system on nuclear spent fuel pool storage. In this experimental wickless heat pipe or two-phase closed thermosyphon (TPCT) is used. Variation of heat flux are 611.24 Watt/m2 - 3291.29 Watt/m2. Variation of filling ratio are 45 - 70%. Variation of initial pressure are -62 to -74 cm Hg. Demineralized water is used as working fluid in the TPCT. The results showed that increasing of heat load leads to an increase of evaporation of the working fluid. The optimum filling ratio obtained for 60% of TPCT evaporator volume, and initial pressure variation gave different TPCT wall temperature characteristic. TPCT showed best performance with 60% filling ratio and can be consider to be applied as passive residual heat removal system or passive cooling system on spent fuel storage pool.Keywords: two-phase closed term syphon, heat pipe, passive cooling, spent fuel storage pool
Procedia PDF Downloads 3303023 A Method for the Extraction of the Character's Tendency from Korean Novels
Authors: Min-Ha Hong, Kee-Won Kim, Seung-Hoon Kim
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The character in the story-based content, such as novels and movies, is one of the core elements to understand the story. In particular, the character’s tendency is an important factor to analyze the story-based content, because it has a significant influence on the storyline. If readers have the knowledge of the tendency of characters before reading a novel, it will be helpful to understand the structure of conflict, episode and relationship between characters in the novel. It may therefore help readers to select novel that the reader wants to read. In this paper, we propose a method of extracting the tendency of the characters from a novel written in Korean. In advance, we build the dictionary with pairs of the emotional words in Korean and English since the emotion words in the novel’s sentences express character’s feelings. We rate the degree of polarity (positive or negative) of words in our emotional words dictionary based on SenticNet. Then we extract characters and emotion words from sentences in a novel. Since the polarity of a word grows strong or weak due to sentence features such as quotations and modifiers, our proposed method consider them to calculate the polarity of characters. The information of the extracted character’s polarity can be used in the book search service or book recommendation service.Keywords: character tendency, data mining, emotion word, Korean novel
Procedia PDF Downloads 3353022 Effect of Sex and Breed on Live Weight of Adult Iranian Pigeons
Authors: Sepehr Moradi, Mehdi Asadi Rad
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This study is to evaluate the live weight of adult pigeons to investigate about their sex, race, their mutual effects and some auxiliary variables in 4 races of Kabood, Tizpar, Parvazy, and Namebar. In this paper, 152 pieces of pigeons as 76 male and female pairs with equal age are studied randomly. Then the birds were weighted by a scale with one gram precision. Software was used for statistical analysis. Mean live weight of adult male and female pigeons in 4 races (Kabood, Tizpar, Parvazy and Namebar with (15, 20, 20, 21) and (20, 21, 18, 17) records were, (530±56, 388.75±32, 392±34, 552±48) and (446±34, 342±32, 341±46, 457±57) gr, respectively. Difference weight of adult live of male with female was significant in 1% level (P < 0.01). Difference live weight of male adult pigeon was significant in 5% level (P < 0.05). Different live weight of female adult pigeon between Kabood, Parvazy and Tizpar races were significant in 5% level (P < 0.05) but mean live weight Kabood race with Namebar race and Parvazy with Tizpar were not significant. The results showed that most and least mean live weights belonged to Namebar of the male pigeon race and Parvazy of the female pigeon race.Keywords: Iranian Native Pigeons, adult weight, live weight, adult pigeons
Procedia PDF Downloads 2023021 Performance Analysis of Air Conditioning System Working on the Vapour Compression Refrigeration Cycle under Magnetohydrodynamic Influence
Authors: Nikhil S. Mane, Mukund L. Harugade, Narayan V. Hargude, Vishal P. Patil
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The fluids exposed to magnetic field can enhance the convective heat transfer by inducing secondary convection currents due to Lorentz force. The use of magnetohydrodynamic (MHD) forces in power generation and mass transfer is increasing steadily but its application to enhance the convective currents in fluids needed to be explored. The enhancement in convective heat transfer using MHD forces can be employed in heat exchangers, cooling of molten metal, vapour compression refrigeration (VCR) systems etc. The effective increase in the convective heat transfer without any additional energy consumption will lead to the energy efficient heat exchanging devices. In this work, the effect of MHD forces on the performance of air conditioning system working on the VCR system is studied. The refrigerant in VCR system is exposed to the magnetic field which influenced the flow of refrigerant. The different intensities of magnets are used on the different liquid refrigerants and investigation on performance of split air conditioning system is done under different loading conditions. The results of this research work show that the application of magnet on refrigerant flow has positive influence on the coefficient of performance (COP) of split air conditioning system. It is also observed that with increasing intensity of magnetic force the COP of split air conditioning system also increases.Keywords: magnetohydrodynamics, heat transfer enhancement, VCRS, air conditioning, refrigeration
Procedia PDF Downloads 2123020 Contributing Factors Affecting the Safety in Construction Sites of Bangladesh
Authors: Farzana Rahman, Mohammed Hossain Ezaz, Dipak Halder, Proshanta Mondal
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Site safety is an important function regardless of project size. A key goal, which must be met for a successful project, is to finish the project with a good safety record. Construction safety is an important issue in all over the world. Today, developed countries strictly follow the safety procedure to avoid any hazard, accident or fatality. However, for a least developed country like Bangladesh, still accidents and fatalities are quite high due to lack of safety management. With the increased volume of construction work in Bangladesh, the need for proper attention in safety issues has become essential for human, economic and other consideration. Recently lots of accidents are taking place in construction sites of Bangladesh causing severe injury to death to the workers and pedestrians. There are a number of reasons/factors that these high numbers are widespread to the construction industry that are not found in most other businesses. The objective of this research work is to identify and explore the various factor that affect the construction site safety in Bangladesh. A questionnaire surveys was conducted to the reputed construction companies of Bangladesh to examine the present safety situation in construction sites. Nine factors were selected for the survey. The finding shows that 78% of organizations’ from the respondents are conscious about the safety procedure and they usually provide safety measures for the workers. Promotion of safety measures at the working site results in a better working environment, higher productivity and greater contentment among the workers.Keywords: construction sites, fatalities, safety issues, safety situation
Procedia PDF Downloads 5693019 Comparison of Live Weight of Pure and Mixed Races Tizpar 30-Day Squabs
Authors: Sepehr Moradi, Mehdi Asadi Rad
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The aim of this study is to evaluate and compare live weight of pure and mixed races Tizpar 30-day pigeons to investigate about their sex, race, and some auxiliary variables. In this paper, 70 pieces of pigeons as 35 male and female pairs with equal age are studied randomly. A natural incubation was done from each pair. All produced chickens were weighted at 30 days age before and after hunger by a scale with one gram precision. A covariance analysis was used since there were many auxiliary variables and unequal observations. SAS software was used for statistical analysis. Mean weight of live in pure race (Tizpar-Tizpar) with 12 records, 182.3±60.9 gr and mixed races of Tizpar-Kabood, Tizpar-Parvazy, Tizpar-Namebar, Kabood-Tizpar, Namebar-Tizpar, and Parvazy-Tizpar with 10, 10, 8, 6, 12, and 12 records were 114.3±71.6, 210.6±71.7, 353.2±86, 520.8±81.5, 288.3±65.6, and 382.6±70.4 gr, respectively. Effects of sex, race and some auxiliary variables were also significant in 1% level (P < 0.01). Difference live weight of 30-day of Tizpar-Tizpar race with Tizpar-Namebar and Parvazi-Tizpar mixed races was significant in 5% level (P < 0.05) and with Kabood-Tizpar mixed races was significant in 1% level (P < 0.01) but with Tizpar-Kabood, Nmaebar-Tizpar and Tizpar-Parvazy mixed races was not significant. The results showed that most and least weights of live belonged to Kabood-Tizpar and Tizpar-Kabood.Keywords: squabs, Tizpar race, 30-day live weight, pigeons
Procedia PDF Downloads 1783018 Gloria Naylor's Linden Hills: A Fine Description of Burdens and Misguided Notions of the Middle Black Community
Authors: Kalluru Maheswaramma, Putta Padma
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This study makes an attempt to demonstrate the wondrous world of the upwardly middle black community in Gloria Naylor’s Linden Hills. Gloria Naylor’s first novel The Women of Brewster Place is about the working class and Linden Hills about middle-class Black America. Naylor believes their serenity that is lost in the middle or working class black people as they move into the upper patriarchal society. Naylor challenges the different forms of superiority, homophobia, and chauvinism, interracial bias, and the like, which plague a community so significantly trying to be acceptable in the larger white community. In an ironic twist, Naylor creates characters that recognize their desire for a solid black community but who in reality ignore blackness and negate any emergent sign of its development. Linden Hills is an expose of the wealthy and spiritually dissolute upper class. Linden Hills is an examination of an upper-middle-class African American community in which women are largely exploited or invisible and in which men have, in the course of upward mobility, sacrificed their racial identity and their essence. Linden Hills is a social world, which includes firm stratification, false values, and an immobilizing impact on its residents. Touching a brief note upon the origin and development of African American Literature as well a note on the chosen writer and her works, the paper proceeds to depict the middle-class black community of Linden Hills.Keywords: gloria naylor, linden hills, African American community, the middle black community
Procedia PDF Downloads 5643017 Comparative Syudy Of Heat Transfer Capacity Limits of Heat Pipe
Authors: H. Shokouhmand, A. Ghanami
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Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also observed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits
Procedia PDF Downloads 3783016 Heat Pipe Thermal Performance Improvement in H-VAC Systems Using CFD Modeling
Authors: H. Shokouhmand, A. Ghanami
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Heat pipe is a simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of the heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force, the liquid phase flows to evaporator section. In HVAC systems, the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally, heat pipes have three main sections: condenser, adiabatic region, and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of the heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances its heat transfer capacity.Keywords: heat pipe, HVAC system, grooved heat pipe, CFD simulation
Procedia PDF Downloads 4973015 Heat Pipes Thermal Performance Improvement in H-VAC Systems Using CFD Modeling
Authors: M. Heydari, A. Ghanami
Abstract:
Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section.In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region and evaporator.Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits
Procedia PDF Downloads 4453014 The Way of Life of the Civil Servant Community under the Bureau of the Royal Household: A Case Study of Tha Wasukri, Bangkok
Authors: Vilasinee Jintalikhitdee, Saowapa Phaithayawat
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The research on “The Way of Life of the Civil Servant Community under the Bureau of the Royal Household” aims to study 1) the way of life of the people who live in the civil servant community in Tha Wasukri, and 2) the model of community administration of civil servants under the Bureau of the Royal Household. This research is conducted qualitatively and quantitatively by collecting data from interviews, focus group discussion, participant and non-participant observation along with the data from the questionnaire based on age groups which include elder group, working age group and youth group. The result of the research shows that the origin of this community is related to the history during the Rama V’s reign. It has been a harbor for the king to boat in any royal ceremonies; this custom is still maintained until today. The status or position of person who serves the king in terms of working is often inherited from the bureau of the Royal Household based on his/her consanguinity and, hence, further receives the rights to live in the Tha Wasukri area. Therefore, this community has some special characteristics demonstrating the way of living influenced by the regulation of the Bureau of the Royal Household such as respecting elders and interdependence in which there is internal social organization with the practice of bureaucracy in going in and out the community. The person who has rights to live here must be friendly to everybody so that this community will be a safe place for lives and property. The administration based on the model of Bangkok for local administration was used as an external structure only, but the way of living still follows the practice of the Bureau of the Royal Household.Keywords: way of life, community, Tha Wasukri, Bureau of the Royal Household
Procedia PDF Downloads 4703013 Sources of Occupational Stress among Teachers in Command Secondary Schools of Nigerian Army
Authors: Mary Esere, Mogbekeloluwa Fakokunde, Adetoun Idowu
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Background: Working in a military setting could elicit some amount of stressful doses into ones system because of the attendant peculiar characteristics found in the military environment. Thus, this study was carried out to find out the sources of occupational stress among teachers in various Command Secondary Schools within 2 Division of Nigerian Army. Method: The study employed a survey method. Simple random sampling technique was used to select the schools in the Division. A total of 200 respondents participated in the study. Sources of Teachers’ Occupational Stress Questionnaire (STOSQ) was administered to the respondents to collect relevant data. The t-test and Analysis of Variance (ANOVA) statistics were used to test the hypotheses. Findings: From the study, it was discovered that teachers in this setting do experience occupational stress. Their major sources of stress bother on issues relating to salaries and allowances and staff welfare concerns. The findings also revealed that there were no significant differences in the sources of occupational stress among the teachers in respect to gender and marital status. Discussion: Based on these findings, it was recommended that the Appropriate Superior Authority (ASA) should reconstitute the proscribed Armed Forces Schools Management Board (AFSMB) where issues, such as staff salaries and welfare concerns for teachers working in the schools under the three services (Army, Navy, Airforce) will always be addressed. This will go a long way in enhancing the psychological well-being of the teachers.Keywords: Nigerian army, occupational stress, sources, teachers
Procedia PDF Downloads 4903012 Shaping Work Engagement through Intra-Organizational Coopetition: Case Study of the University of Zielona Gora in Poland
Authors: Marta Moczulska
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One of the most important aspects of human management in an organization is the work engagement. In spite of the different perspectives of engagement, it is possible to see that it is expressed in the activity of the individual involved in the performance of tasks, the functioning of the organization. At the same time is considered not only in behavioural but also cognitive and emotional dimensions. Previous studies were related to sources, predictors of engagement and determinants, including organizational ones. Attention was paid to the importance of needs (including belonging, success, development, sense of work), values (such as trust, honesty, respect, justice) or interpersonal relationships, especially with the supervisor. Taking them into account and theories related to human acting, behaviour in the organization, interactions, it was recognized that engagement can be shaped through cooperation and competition. It was assumed that to shape the work engagement, it is necessary to simultaneously cooperate and compete in order to reduce the weaknesses of each of these activities and strengthen the strengths. Combining cooperation and competition is defined as 'coopetition'. However, research conducted in this field is primarily concerned with relations between companies. Intra-organizational coopetition is mainly considered as competing organizational branches or units (cross-functional coopetition). Less attention is paid to competing groups or individuals. It is worth noting the ambiguity of the concepts of cooperation and rivalry. Taking into account the terms used and their meaning, different levels of cooperation and forms of competition can be distinguished. Thus, several types of intra-organizational coopetition can be identified. The article aims at defining the potential for work engagement through intra-organizational coopetition. The aim of research was to know how levels of cooperation in competition conditions influence engagement. It is assumed that rivalry (positive competition) between teams (the highest level of cooperation) is a type of coopetition that contributes to working engagement. Qualitative research will be carried out among students of the University of Zielona Gora, realizing various types of projects. The first research groups will be students working in groups on one project for three months. The second research group will be composed of students working in groups on several projects in the same period (three months). Work engagement will be determined using the UWES questionnaire. Levels of cooperation will be determined using the author's research tool. Due to the fact that the research is ongoing, results will be presented in the final paper.Keywords: competition, cooperation, intra-organizational coopetition, work engagement
Procedia PDF Downloads 1463011 42CrMo4 Steel Flow Behavior Characterization for High Temperature Closed Dies Hot Forging in Automotive Components Applications
Authors: O. Bilbao, I. Loizaga, F. A. Girot, A. Torregaray
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The current energetical situation and the high competitiveness in industrial sectors as the automotive one have become the development of new manufacturing processes with less energy and raw material consumption a real necessity. As consequence, new forming processes related with high temperature hot forging in closed dies have emerged in the last years as new solutions to expand the possibilities of hot forging and iron casting in the automotive industry. These technologies are mid-way between hot forging and semi-solid metal processes, working at temperatures higher than the hot forging but below the solidus temperature or the semi solid range, where no liquid phase is expected. This represents an advantage comparing with semi-solid forming processes as thixoforging, by the reason that no so high temperatures need to be reached in the case of high melting point alloys as steels, reducing the manufacturing costs and the difficulties associated to semi-solid processing of them. Comparing with hot forging, this kind of technologies allow the production of parts with as forged properties and more complex and near-net shapes (thinner sidewalls), enhancing the possibility of designing lightweight components. From the process viewpoint, the forging forces are significantly decreased, and a significant reduction of the raw material, energy consumption, and the forging steps have been demonstrated. Despite the mentioned advantages, from the material behavior point of view, the expansion of these technologies has shown the necessity of developing new material flow behavior models in the process working temperature range to make the simulation or the prediction of these new forming processes feasible. Moreover, the knowledge of the material flow behavior at the working temperature range also allows the design of the new closed dies concept required. In this work, the flow behavior characterization in the mentioned temperature range of the widely used in automotive commercial components 42CrMo4 steel has been studied. For that, hot compression tests have been carried out in a thermomechanical tester in a temperature range that covers the material behavior from the hot forging until the NDT (Nil Ductility Temperature) temperature (1250 ºC, 1275 ºC, 1300 ºC, 1325 ºC, 1350ºC, and 1375 ºC). As for the strain rates, three different orders of magnitudes have been considered (0,1 s-1, 1s-1, and 10s-1). Then, results obtained from the hot compression tests have been treated in order to adapt or re-write the Spittel model, widely used in automotive commercial softwares as FORGE® that restrict the current existing models up to 1250ºC. Finally, the obtained new flow behavior model has been validated by the process simulation in a commercial automotive component and the comparison of the results of the simulation with the already made experimental tests in a laboratory cellule of the new technology. So as a conclusion of the study, a new flow behavior model for the 42CrMo4 steel in the new working temperature range and the new process simulation in its application in automotive commercial components has been achieved and will be shown.Keywords: 42CrMo4 high temperature flow behavior, high temperature hot forging in closed dies, simulation of automotive commercial components, spittel flow behavior model
Procedia PDF Downloads 1293010 Improve Heat Pipe Thermal Performance in H-VAC Systems Using CFD Modeling
Authors: H. Shokouhmand, A. Ghanami
Abstract:
A heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At a hot surface of the heat pipe, the liquid phase absorbs heat and changes to the vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to the liquid phase. Due to gravitational force the liquid phase flows to the evaporator section. In HVAC systems, the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses the heater, humidifier, or dryer is a suitable nominate for the utilization of heat pipes. Generally, heat pipes have three main sections: condenser, adiabatic region, and evaporator. Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of the heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian-Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances its heat transfer capacity.Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits
Procedia PDF Downloads 4403009 Three-Dimensional Spillage Effects on the Pressure Distribution of a Double Ramp
Authors: Pengcheng Quan, Shan Zhong
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Double ramp geometry is widely used in supersonic and hypersonic environments as it presents unique flow patterns for shock wave-boundary layer interaction studies as well as for two-dimensional inlets and deflected control surfaces for re-entry vehicles. Hence, the surface pressure distribution is critical for optimum design. Though when the model is wide enough on spanwise direction the flow can be regarded as a two-dimensional flow, in actual applications a finite width would normally cause some three-dimensional spillage effects. No research has been found addressed this problem, hence the primary interest of this study is to set up a liable surface pressure distribution on a double ramp with three-dimensional effects. Both numerical and experimental (pressure sensitive paints) are applied to obtain the pressure distribution; the results agree well except that the numerical computation doesn’t capture the Gortler vortices. The pressure variations on the spanwise planes are used to analyse the development of the Gortler vortices and the effects of three-dimensional spillage on the vortices. Results indicate that the three-dimensionl spillage effects not only enhance the developing of the Gortler vortice, but also increase the periodic distance between vortice pairs.Keywords: spillage effects, pressure sensitive paints, hypersonic, double ramp
Procedia PDF Downloads 332