Search results for: “warm” mortars

Authors: Mahmoud M. Tash, S. Alkahtani

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The present study was undertaken to investigate the effect of pre-aging and aging parameters (time and temperature) on the mechanical properties of Al-Mg-Zn (7075) alloys. Ultimate tensile strength, 0.5% offset yield strength and % elongation measurements were carried out on specimens prepared from cast and heat treated 7075 alloys. Aging treatments were carried out for the as solution treated (SHT) specimens (after quenching in warm water). The specimens were aged at different conditions; Natural aging was carried out at room temperature for different periods of time. Double aging was performed for SHT conditions (pre-aged at different time and temperature followed by high temperature aging). Ultimate tensile strength, yield strength and % elongation as a function of different pre-aging and aging parameters are analysed to acquire an understanding of the effects of these variables and their interactions on the mechanical properties of Be-treated 7075 alloys.

Keywords: duplex aging treatment, mechanical properties, Al-Mg-Zn (7075) alloys, manufacturing

Procedia PDF Downloads 219

Authors: Abdulrahman M. Homadi

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As a great source of renewable energy, solar energy is considered to be one of the most important in the world, since it will be one of solutions cover the energy shortage in the future. Photovoltaic (PV) is the most popular and widely used among solar energy technologies. However, PV efficiency is fairly low and remains somewhat expensive. High temperature has a negative effect on PV efficiency and cooling system for these panels is vital, especially in warm weather conditions. This paper presents the results of a simulation study carried out on silicon solar cells to assess the effects of elevation on enhancing the efficiency of solar panels. The study included four different terrains. The study also took into account the direction of the wind hitting the solar panels. To ensure the simulation mimics reality, six silicon solar panels are designed in two columns and three rows, facing to the south at an angle of 30 ^o. The elevations are assumed to change from 10 meters to 200 meters. The results show that maximum increase in efficiency occurs when the wind comes from the north, hitting the back of the panels.

Keywords: solar panels, elevation, wind direction, efficiency

Procedia PDF Downloads 274

Authors: Pibool Waijittragum

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This paper has its objectives to reveal contents and personality suitable to women’s newspapers. The research methodology employed in this study is the questionnaire which is derived from a literature review related to newspapers, graphic elements method for print media design and 12 sample sizes of different daily newspapers. In order to acquire an in-depth understanding and comprehensible view of desirable for a women’s newspaper design, graphic elements that related to that personality as well as other preferable elements for a women’s newspaper, including seven editorial Many Thai newspapers were offer a women’s documentary and column space. With its feminine looks, most of them appeared with warm tones and friendly mood through their headlines, contents, illustrations and graphics. The study found that most desirable personalities for a women’s newspaper design in Thailand are: Modern, Chic and Natural. Each personality has significant graphic elements as follows: 1. Modern: significant elements of modern personality comprises of the composition with graduation pattern which creates attractiveness by using an anomalous alignment layout grid and outstanding structure to create focal points and dynamic movement. Dark to black color that has narrowed, limited hue coupled with bright color tones. The round shape of the Thai font style was suitable for this concept. Such Thai fonts have harmonious proportion and consistent stroke with the urban-polite look. 2. Chic: significant elements of chic personality comprises of the proper composition with distinctive scale, using rhythmic repetition and a contrast of scale to draw in reader attention. Vivid and bright color tones with extensive hues coupled with similar color tones and round shape of the Thai font style with a light stroke and consistent line. 3. Natural: significant elements of natural personality comprises of the proper composition using rhythmic repetition that creates a focal point through striking images and harmonious perspective. Warm color tones with restricted hues that appear to look natural. Duo tone color was suitable through the gradually increasing gradient. The Thai style with hand writing font was suitable through the inconsistent stroke. There are 10 types of daily content that were revealed to be the most desirable for Thai women readers, these are: Daily News, Economics News, Education News, Entertainment News, International news, Political News, Public Health News, Scientific News, Social News and Sports News. As well, there are 16 topics identified as very desirable for Thai women readers, such as: Art and Culture, Automobile, Classified, Special Scoop, Editorial, Advertisement, Entertainment, Health and Quality of Life, History, Horoscope, Lifestyle and Fashion, Literature, Nature - Environment and Tourism, Night Life, Stars and Jet Set Gossip, Women’s Issue.

Keywords: women behaviors, feminine looks, newspaper design, news content

Procedia PDF Downloads 147

Authors: M. Guen

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A three-dimensional numerical study is used to analyze the behavior of the flow inside a vortex tube. The vortex tube or Ranque-Hilsch vortex tube is a simple device which is capable of dividing compressed air from the inlet nozzle tangentially into two flow with different temperatures warm and cold. This phenomenon is known from literature by temperature separation. The K ω-SST and K-ε turbulence models are used to predict the turbulent flow behaviour inside the tube. The vortex tube is an Exair 708 slpm (25 scfm) commercial tube. The cold and hot exits areas are 30.2 and 95 mm2 respectively. The vortex nozzle consists of 6 straight slots; the height and the width of each slot are 0.97 mm and 1.41 mm. The total area normal to the flow associated with six nozzles is therefore 8.15 mm 2. The present study focuses on a comparison between two turbulence models K ω-SST, K-ε by using a new configuration of vortex tube (Conical Vortex Tube). The performance curves of the temperature separation versus cold outlet mass fraction were calculated and compared with experimental and numerical study of other researchers.

Keywords: conical vortex tube, temperature separation, cold mass fraction, turbulence

Procedia PDF Downloads 233

Authors: Adedayo Jeremiah Adeyekun, Samuel Oluwagbemiga Ishola

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This research aims to study the use of traditional building materials for the repair and refurbishment of historic buildings in India and to provide an authentic treatment of historical buildings that will be highly considered by taking into consideration the new standards of rehabilitating process. This can be proven to be an effective solution over modern impervious material due to its compatibility with traditional building methods and materials. For example, their elastoplastic properties allow accommodating movement due to settlement or moisture/temperature changes without cracking. The use of lime also enhances workability, water retention and bond characteristics. Lime is considered to be a natural, traditional material, but it is also sustainable and energy-efficient, with production powered by biomass and emissions up to 25% less than cementitious materials. However, there is a lack of comprehensive data on the impact of lime‐based materials on the energy efficiency and thermal properties of traditional buildings and structures. Although lime mortars, renders and plasters were largely superseded by cement-based products in the first half of the 20th century, lime has a long and proven track record dating back to ancient times. This was used by the Egyptians in 4000BC to construct the pyramids. This doesn't mean that lime is an outdated technology, nor is it difficult to be used as a material. In fact, lime has a growing place in modern construction, with increasing numbers of designers choosing to use lime-based products because of their special properties. To carry out this research, some historic buildings will be surveyed and information will be derived from the textbooks and journals related to Architectural restoration.

Keywords: lime, materials, historic, buildings, sustainability

Procedia PDF Downloads 148

Authors: Aman Patidar, Dipankar Sarkar, Manish Pal

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Due to rapid development, increase in the traffic load, higher traffic volume and seasonal variation in temperature, asphalt pavement shows distresses like rutting, fatigue and thermal cracking etc. because of this pavement fails during service life so that bitumen needs to be modified with some additive. In this study VG30 grade bitumen modify with addition of nanosilica with 1% to 5% (increment of 1%) by weight of bitumen. Hot mix asphalt (HMA) have higher mixing, laying and rolling temperatures which leads to higher consumption of fuel. To address this issue, a nano material named ZycoTherm which is chemical warm mix asphalt (WMA) additive is added to bitumen. Nanosilica modification (NSMB) results in the increase in stability compared to unmodified bitumen (UMB). WMA modified mix shows slightly higher stability than UMB and NSMB in a lower bitumen content. The Retained stability and tensile strength ratio (TSR) is more than 75% and 80% respectively for both mixes. Nanosilica with WMA has more resistant to temperature susceptibility, moisture susceptibility and short term aging than NSMB.

Keywords: HMA, nanosilica, NSMB, temperature, TSR, UMB, WMA

Procedia PDF Downloads 285

Authors: Philip Symonds, Jon Taylor, Zaid Chalabi, Michael Davies

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With the world climate projected to warm and major cities in developing countries becoming increasingly populated and polluted, governments are tasked with the problem of overheating and air quality in residential buildings. This paper presents the development of an adaptable model of these risks. Simulations are performed using the EnergyPlus building physics software. An accurate metamodel is formed by randomly sampling building input parameters and training on the outputs of EnergyPlus simulations. Metamodels are used to vastly reduce the amount of computation time required when performing optimisation and sensitivity analyses. Neural Networks (NNs) are compared to a Radial Basis Function (RBF) algorithm when forming a metamodel. These techniques were implemented using the PyBrain and scikit-learn python libraries, respectively. NNs are shown to perform around 15% better than RBFs when estimating overheating and air pollution metrics modelled by EnergyPlus.

Keywords: neural networks, radial basis functions, metamodelling, python machine learning libraries

Procedia PDF Downloads 424

Authors: Ghulam Zahra

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Parenting style affects the morality of their children. There is plenty of evidence to support the effect of parenting styles on the morality of their children. Therefore, this research is considered essential and suitable. Thus, the main objective of this study was to assess the correlation between the parenting style of mothers and the moral development of primary school students. The population consisted of all primary school students enrolled in the province of Punjab. The sample was comprised of twelve hundred thirty-nine primary school students. One questionnaire was adapted to explore the parenting styles of mothers and to assess the level of students’ level of morality; a moral development scale was adopted. The conclusions showed that there was a significant correlation exist among authoritarian parenting style, permissive parenting, and moral developments. Based on findings, it is recommended that parents should follow a warm style of parenting for the sake of the moral development of their children.

Keywords: maternal parenting style, moral development, authoritative parenting, authoritarian parenting, permissive parenting

Procedia PDF Downloads 91

Authors: Bulus Kpame, Mukhtar Mohammed Alhaji, Garba Jibril

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In any team sport, the most important variables that should be used to measure performance are physical condition, and technical and tactical performance. In a complex game like football, it is extremely difficult to measure the relative importance of each of these variables. However, physical fitness itself has been shown to consist of several components, like endurance, strength, flexibility, agility, coordination and speed. Each of these components has been shown to consist of several subcomponents. This paper attempts to describe a test battery to assess and evaluate physical performance in football players. This battery comprises a functional, structured training session of about 2.5hrs. it consists of quality rating of the warm-up procedure, tests of flexibility, football skills, power, speed, and endurance. Acceptable values for performance in each of the tests are also presented under each test. It is hoped that this battery of tests will be helpful to the coach in determining the effect of a specific training program. It would also be helpful to train physician and trainer, to monitor progress during rehabilitation after sustaining any injury.

Keywords: assessment, evaluation, performance, programs

Procedia PDF Downloads 378

Authors: Vaibhav Garg

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The concept of guest engagement lies in the rigor of operational excellence and the emotional engagement of associates who perform their tasks genuinely from their hearts and hence in word and indeed, in intent and through gestures, a great hospitality is always genuine, attentive, passionate, caring and warm where engaged associates deliver exceptional service experiences and creates memories to last forever for the guests. One out of every five guests says that their decision of coming back to the same hotel is influenced by the opportunity to “experience and be engaged” A key question is what does a guest mean by experience and be engaged? Most hotels are highly concerned about the guest satisfaction. Therefore they have the brand standards which are a guide to the associate to ensure consistent implementation of set service and product standards to satisfy a guest. However, satisfaction of basic guest needs does not necessarily lead to engagement. For example an absolutely clean room and an in room dining order delivered on time can satisfy a guest but may not engage him. Absence of these standards can certainly lead to guest dissatisfaction however; the presence of these standards does not necessarily lead to guest engagement or guest delight.

Keywords: guest engagement, guest satisfaction, hospitality, hotel operations, operational excellence

Procedia PDF Downloads 224

Authors: Amir Reza Radmanesh, Sina Farajzadeh Khosroshahi, Hani Sadr

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The transient catalytic converter performance is governed by complex interactions between exhaust gas flow and the monolithic structure of the catalytic converter. Stringent emission regulations around the world necessitate the use of highly-efficient catalytic converters in vehicle exhaust systems. Computational fluid dynamics (CFD) is a powerful tool for calculating the flow field inside the catalytic converter. Radial velocity profiles, obtained by a commercial CFD code, present very good agreement with respective experimental results published in the literature. However the applicability of CFD for transient simulations is limited by the high CPU demands. In the present work, Geometric modeling ceramic monolith substrate is done with square shaped channel type of Catalytic converter and it is coated platinum and palladium. This example illustrates the effect of flow distribution on thermal response of a catalytic converter and different gas flow velocities, during the critical phase of catalytic converter warm up.

Keywords: catalytic converter, computational fluid dynamic, porous media, velocity distribution

Procedia PDF Downloads 834

Authors: Widayat Widayat

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Nowday, in the modern investment era, household behavior on investment is a topic that is quite warm. The development of the modern investment, indicated by the emergence of a variety of investment instruments, such as stocks, bonds and various forms of derivatives, affected on the complexity of choosing an investment, especially for traditional societies. Various studies show that there is more than one factor acting as a behavioral antesenden decide to choose an investment instrument. One of the factors, which contribute in determining the investment option is ethnic. Society with a particular sub-culture tend to prefer investing their particular instrument. This is because they have the values, norms and different social environmental. This article is designed to test the impact of sub-cultures between Osing-Java as moderator, in investing. The study was conducted in Banyuwangi, East Java Province of Indonesia. Data were collected using questionnaires, which is given to the head of the household respondents were selected as samples. Sample of households selected by multistage sampling method. The data have been collected processed using SmartPLS software and testing moderating effects using grouped sample test. The result showed that sub-ethnic and has a significant role in determining the investment.

Keywords: investment behaviour, household, moderating, sub ethnic

Procedia PDF Downloads 351

Authors: Tiedan Huang, Chun Zhang, Caitlin Coe

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This study investigated the quality of instructional support for young Emergent Multilingual Learners (EMLs) in 50 Universal Prekindergarten (UPK) classroom in New York City (NYC). This is one of the first empirical studies examining the instructional support for this student population. We collected data using a mixed method of structured observations of teacher-child interactions in 50 classrooms, and surveys and interviews with program leaders and the teaching teams. We found that NYC’s UPK classrooms offered warm and supportive environments for EMLs. Nevertheless, in general, instructional support was relatively low. This study identified large mindset, knowledge, and practice gaps—and a real opportunity—among NYC early childhood professionals, specifically in the areas of providing adequate instructional and linguistic support for EMLs as well as partnering with families in capturing their cultural and home literacy assets. Consistent, rigorous, and meaningful use of data is necessary to support both EMLs’ language and literacy development and teachers’/leaders’ professional development.

Keywords: high quality instruction, culturally and linguistically responsive practices, professional development, workforce development

Procedia PDF Downloads 61

Authors: Courret Gilles, Pidoux Damien

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Considering that sunshine is the ultimate reference in lighting, we have examined the spectral correlation between a series of electric light sources and sunlight. As the latter is marked by fluctuations, we have taken two spectra of reference: on the one hand, the CIE daylight standard illuminant, and on the other hand, the global illumination by the clear sky with the sun at 30° above the horizon. We determined the coefficients of correlation between the spectra filtered by the sensitivity of the CIE standard observer for photopic vision. We also calculated the luminous efficiency of the radiation in order to compare the ideal energy performances as well as the CIE color indexes Ra, Ra14, and Rf, since the choice of a light source requires a trade-off between color rendering and luminous efficiency. The benchmarking includes the most commonly used bulbs, various white LED (Lighting Emitting Diode) of warm white or cold white types, incandescent halogen as well as two HID lamps (High-Intensity Discharge) and two plasma lamps of different types, a solar simulator and a new version of the sulfur lamp. The latter obtains the best correlation, whether in comparison with the solar spectrum or that of the standard illuminant.

Keywords: electric light sources, plasma lamp, daylighting, sunlight, spectral correlation

Procedia PDF Downloads 163

Authors: Mohsen Salesi, Seyyed Zoheir Rabei

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Exercise has been considered a cornerstone of diabetes prevention and treatment for decades, but the benefits of resistance training are less clear. The purpose of this study was to determine the impact of resistance training on blood profile and inflammatory marker (CRP) of type 2 diabetes mellitus people. Thirty diabetic male were recruited (age: 50.34±10.28 years) and randomly assigned to 8 weeks resistance exercise training (n=15) and control groups (n=15). Before and after training blood pressure, weight, lipid profile (TC, TG, LDL-c, and HDL-c) and hs-CRP were measured. The resistance exercise training group took part in supervised 50–80 minutes resistance training sessions, three days a week on non-consecutive days for 8 weeks. Each exercise session included approximately 10 min of warm-up and cool-down periods. Results showed that TG significantly decreased (pre 210.19±9.31 vs. 101.12±7.25, p=0.03) and HDL-c significantly increased (pre 42.37±3.15 vs. 47.50±2.19, p=0.01) after exercise training. However, there was no difference between groups in TC, LDL-c, BMI and weight. In addition, a decrease in fasting blood glucose levels showed significant difference between groups (pre 144.65±5.73 vs. 124.21±6.48 p=0.04). Regular resistance exercise training can improve the lipid profile and reducing the cardiovascular risk factors in T2DM patients.

Keywords: lipid profile, resistance exercise, type 2 diabetes mellitus, men

Procedia PDF Downloads 387

Authors: K. Eshwara Prasad, R. Raman Goud, Swadesh Kumar Singh, N. Sateesh

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In the present work forming limit diagrams and strain distribution profile diagrams for extra deep drawing steel at room and elevated temperatures have been determined experimentally by conducting stretch forming experiments by using designed and fabricated warm stretchforming tooling setup. With the help of forming Limit Diagrams (FLDs) and strain distribution profile diagrams the formability of Extra Deep Drawing steel has been analyzed and co-related with mechanical properties like strain hardening COEFFICIENT (n) and normal anisotropy (r−).Mechanical properties of EDD steel from room temperature to 4500C were determined and discussed the impact of temperature on the properties like work hardening exponent (n) anisotropy(r-) and strength coefficient of the material. Also the fractured surfaces after stretching have undergone the some metallurgical investigations and attempt has been made to co-relate with the formability of EDD steel sheets. They are co-related and good agreement with FLDs at various temperatures.

Keywords: FLD, microhardness, strain distribution profile, stretch forming

Procedia PDF Downloads 304

Authors: Lanre Oluwafemi Akinyemi

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The reduction of limestone to cement in Nigeria is expensive and requires huge amounts of energy. This significantly affects the cost of cement. Concrete is heavy: a cubic foot of it weighs about 150 lbs. and a cubic yard is about 4000 lbs. Thus a ready-mix truck with 9 cubic yards is carrying 36,000 lbs excluding the weight of the truck itself, thereby accumulating cost for also manufacturers. Therein lies the need to find a substitute for cement by using the polystyrene paste that benefits both the manufactures and the consumers. Polystyrene Paste Constructional Cement (PPCC), a patented material obtained by dissolving Waste EPS in volatile organic solvent, has recently been identified as a suitable binder/cement for construction and building material production. This paper illustrates the procedures of a test experiment undertaken to determine the splitting tensile strength of PPCC mortar compared to that of OPC (Ordinary Portland Cement). Expanded polystyrene was dissolved in gasoline to form a paste referred to as Polystyrene Paste Constructional Cement (PPCC). Mortars of mix ratios 1:4, 1:5, 1:6, 1:7 (PPCC: fine aggregate) batched by volume were used to produce 50mm x 100mm cylindrical PPCC mortar splitting tensile strength specimens. The control experiment was done by creating another series of cylindrical OPC mortar splitting tensile strength specimens following the same mix ratio used earlier. The PPCC cylindrical splitting tensile strength specimens were left to air-set, and the ones made with Ordinary Portland Cement (OPC) were demoded after 24 hours and cured in water. The cylindrical PPCC splitting tensile strength specimens were tested at 28 days and compared with those of the Ordinary Portland cement splitting tensile strength specimens. The result shows that hence for this two mixes, PPCC exhibits a better binding property than the OPC. With this my new invention I recommend the use of PPCC as a substitute for a Portland cement.

Keywords: polystyrene paste, Portland cement, construction, mortar

Procedia PDF Downloads 137

Authors: Eshwara Prasad Koorapati, R. Raman Goud, Swadesh Kumar Singh

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In the present work forming limit diagrams and strain distribution profile diagrams for extra deep drawing steel at room and elevated temperatures have been determined experimentally by conducting stretch forming experiments by using designed and fabricated warm stretch forming tooling setup. With the help of forming Limit Diagrams (FLDs) and strain distribution profile diagrams the formability of Extra Deep Drawing steel has been analyzed and co-related with mechanical properties like strain hardening coefficient (n) and normal anisotropy (r−).Mechanical properties of EDD steel from room temperature to 4500 C were determined and discussed the impact of temperature on the properties like work hardening exponent (n) anisotropy (r-) and strength coefficient of the material. Also, the fractured surfaces after stretching have undergone the some metallurgical investigations and attempt has been made to co-relate with the formability of EDD steel sheets. They are co-related and good agreement with FLDs at various temperatures.

Keywords: FLD, micro hardness, strain distribution profile, stretch forming

Procedia PDF Downloads 403

Authors: U. P. Rathnakar, Sejpal Jaykumar, Shenoy K. Ashok

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The effect of Shilajit was investigated for lipid lowering activity and its effect on weight gain in Wistar albino rats. Shilajit, semi-hard brownish black resin formed through long-term humidification of several plant types, mainly bryophytes, can be obtained from steep rocks of the Himalayas at altitudes between 1000 to 5000 meters. Hyperlipidemia was produced by feeding the rats with the cholesterol-rich high-fat diet (HFD) for 2 months. This diet contained deoxycholic acid, cholesterol and warm coconut oil in powdered rat chow diet. At the end of study, Shilajit treated rats showed significant decrease in serum LDL, triglyceride and total cholesterol level as well as increase in serum HDL level, in comparison to rats fed on high-fat diet with no treatment. Also during study period, increase in weight in Shilajit treated group was significantly less than in the other group of rats fed on high-fat diet with no treatment. Thus, Shilajit has significantly controlled the development of hyperlipidemia and weight gain in high-fat diet fed rats in the present study.

Keywords: Shilajit, hyperlipidemia, weight control, cholesterol-rich high-fat diet

Procedia PDF Downloads 164

Authors: M. Sorahi Nobar, V. Niknam, H. Ebrahimzadeh, H. Soltanloo

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Fusarium graminearum is one of the most destructive crop diseases in the world. Infection occurs during the flowering period in warm and humid conditions. It causes reduction in yield. Moreover, harvested grain is often contaminated with mycotoxins and its acetylated derivatives. Fusarium mycotoxines are potent inhibitor of protein synthesis, and thereby presents hazards for both human and animal health. A rapid production of reactive oxygen intermediates, primarily superoxide and hydrogen peroxide at the site of attempted infection considered as key feature underlying successful pathogen recognition. Here, we compared the time course activity of superoxide dismutase (SOD) as a first line of defenses against ROS- induced oxidative burst between FHB- resistant Sumai3 and susceptible Falat at 48, 96 and 144 hours after infection. Our results showed that Sumai3 SOD activity increased with time and reached the highest-level 4 days after infection while in susceptible cultivar Falat, SOD activity decreased during the first 96 h. after infection. Decreased was followed by an increased at 6 days after infection. According to our results rapid induction of SOD activity in resistant cultivar may play an important role in resistance against FHB in wheat.

Keywords: Fusarium graminearum, mycotoxins, resistant cultivar, superoxide dismutase

Procedia PDF Downloads 423

Authors: R. M. Chandler, A. J. Stringer

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In adults, short bursts of high-intensity exercise (intensities between 80-95% of maximum heart rates) increase cardiovascular and metabolic function without the time investment of traditional aerobic training. Similar improvements in various health indices are also becoming increasingly evident in children in countries other than the United States. In the United States, physical education programs have become shorter in length and fewer in frequency. With this in the background, it is imperative that health and physical educators delivered well-organized and focused fitness programs that can be tolerated across many different somatotypes. Perhaps the least effective lag-time in a US physical education (PE) class is the first 10 minutes, a time during which children warm up. Replacing a traditional PE warmup with a 10 min high-intensity excise protocol is a time-efficient method to impact health, leaving as much time for other PE material such as skill development, motor behavior development as possible. This supplemented 10 min high-intensity exercise increases cardiovascular function as well as induces favorable body composition changes in as little as six weeks with further enhancement throughout a semester of activity. The supplemental high-intensity exercise did not detract from the PE lesson outcomes.

Keywords: cardiovascular fitness, high intensity interval training, high intensity exercise, pediatric

Procedia PDF Downloads 119

Authors: Abdeljalil Métioui

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The purpose of this paper is to present the results of research on the conceptual representations of 128 Quebec (Canada) pre-service teachers enrolled in their third year of university in a program to train elementary teachers about heat and temperature. To identify their conceptual representations about heat and temperature, we constructed a multiple-choice questionnaire consisting of five questions. For each question, they had to explain their choice of an answer. At the methodological level, this step is essential to be able to identify the student conceptual representations. It should be noted that the selected questions were based: (1) on the works have done worldwide on primary and secondary students’ misconceptions about heat and temperature; (2) on the notions prescribed in the curriculum related to the physical world and (3) on student’s everyday contexts. As illustrations, the following are the erroneous conceptual representations identified in our analysis of the data collected: (1) The change of state of the matter does not require a constant temperature, (2) The temperature is a measure in degrees to indicate the level of heat of an object or person, (3) The mercury contained in a thermometer expands when it is heated so that the particles which constitute it expand and (4) The sensation of cold (or warm) is related to the difference in temperature. In conclusion, we will see that it is possible to develop situations of conflict, dealing specifically with the limits of the analogy between heat and temperature. These situations must consider the conceptual representations of the pre-service teachers, as well as the relevant scientific understanding of the concept of heat and temperature.

Keywords: conceptual representation, heat, temperature, pre-service teachers

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Authors: Benseghir Omar, Bahmed Mohamed

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In this work, we presented a numerical study of the phenomenon of heat transfer through the laminar, incompressible and steady mixed convection in a closed square cavity with the left vertical wall of the cavity is subjected to a warm temperature, while the right wall is considered to be cold. The horizontal walls are assumed adiabatic. The governing equations were discretized by finite volume method on a staggered mesh and the SIMPLER algorithm was used for the treatment of velocity-pressure coupling. The numerical simulations were performed for a wide range of Reynolds numbers 1, 10, 100, and 1000 numbers are equal to 0.01,0.1 Richardson, 0.5,1 and 10.The analysis of the results shows a flow bicellular (two cells), one is created by the speed of the fan placed in the inner cavity, one on the left is due to the difference between the temperatures right wall and the left wall. Knowledge of the intensity of each of these cells allowed us to get an original result. And the values obtained from each of Nuselt convection which allow to know the rate of heat transfer in the cavity.Finally we find that there is a significant influence on the position of the fan on the heat transfer (Nusselt evolution) for values of Reynolds studied and for low values of Richardson handed this influence is negligible for high values of the latter.

Keywords: thermal transfer, mixed convection, square cavity, finite volume method

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Authors: Mawande Dlali

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This paper examines the request strategies in commuter discourse involving taxi drivers and passengers in Khayelitsha as well as the responses to these requests. The present study considers requests in commuter transport as face threatening acts (FTAs), hence the need for the commuter crew to strategically shape their communicative actions to achieve their overall discourse goal of getting passengers to perform actions that are in their own interest with minimum resistance or confrontation. The crew presents itself by using communicative devices that prompt the passengers to evaluate it positively as warm, friendly, and respectful. However, the passengers' responses to requests range from compliance to resistance depending on their interpretation of the speaker’s motive and the probable social consequences. Participant observation by the researcher was the main method of collecting examples of requests and responses to the requests. Unstructured interviews and informal discussions were made with randomly selected taxi drivers and commuters. The findings and explanations presented in this article revealed the predominance of polite requests as speech acts in taxi discourse in Khayelitsha. This research makes a contribution to the contemporary pragmatics study of African languages in urban context.

Keywords: face threatening acts, speech acts, request strategies, discourse

Procedia PDF Downloads 140

Authors: Chi-Wai Kan, Yanming Wang, Alan Yiu-Lun Tang, Cheng-Hao Lee Lee

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Dyeing of polyester/cotton blend fabrics in various polyester/cotton percentages (32/68, 40/60 and 65/35) was investigated using (poly(ethylene glycol), PEG) based reverse-micelle. High energy disperse dyes and warm type reactive dyes were encapsulated and applied on polyester/cotton blend fabrics in a one bath one step dyeing process. Comparison of reverse micellar-based and aqueous-based (water-based) dyeing was conducted in terms of colour reflectance. Experimental findings revealed that the colour shade of the dyed fabrics in reverse micellar non-aqueous dyeing system at a lower dyeing temperature of 98°C is slightly lighter than that of conventional aqueous dyeing system in two-step process (130oC for disperse dyeing and 70°C for reactive dyeing). The exhaustion of dye in polyester-cotton blend fabrics, in terms of colour reflectance, were found to be highly fluctuated at dyeing temperature of 98°C.

Keywords: one-bath dyeing, polyester/cotton blends, disperse/reactive dyes, reverse micelle

Procedia PDF Downloads 128

Authors: K. L. Virupaksha Gupta

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Ayurveda offers a holistic outlook regarding skin care. Most Initial step in Ayurveda is to identify the skin type and care accordingly which is highly personalized. Though dermatologically there are various skin type classifications such Baumann skin types (based on 4 parameters i) Oily Vs Dry ii) Sensitive Vs Resistant iii) Pigmented Vs Non-Pigmented iv) Wrinkled Vs Tight (Unwrinkled) etc but Skin typing in Ayurveda is mainly determined by the prakriti (constitution) of the individual as well as the status of Doshas (Humors) which are basically of 3 types – i.e Vata Pitta and Kapha,. Difference between them is mainly attributed to the qualities of each dosha (humor). All the above said skin types can be incorporated under these three types. The skin care modalities in each of the constitution vary greatly. Skin of an individual of Vata constitution would be lustreless, having rough texture and cracks due to dryness and thus should be given warm and unctuous therapies and oil massage for lubrication and natural moisturizers for hydration. Skin of an individual of Pitta constitution would look more vascular (pinkish), delicate and sensitive with a fair complexion, unctuous and tendency for wrinkles and greying of hair at an early age and hence should be given cooling and nurturing therapies and should avoid tanning treatments. Skin of an individual of kapha constitution will have oily skin, they are delicate and look beautiful and radiant and hence these individuals would require therapies to mainly combat oily skin. Hence, the skin typing and skin care in Ayurveda is highly rational and scientific.

Keywords: Ayurveda, dermatology, Dosha, skin types

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Authors: Jaime Carpio-García, Elena Blanco-Fernández, Jorge Rodríguez-Hernández, Daniel Castro-Fresno

Abstract:

Geosynthetic mechanical behavior vs temperature or vs aging has been widely studied independently during the last years, both in laboratory and in outdoor conditions. This paper studies this behavior deeper, considering that geosynthetics have to perform adequately at different outdoor temperatures once they have been subjected to a certain degree of aging, and also considering the different geosynthetic structures made of the same material. This combining effect has been not considered so far, and it is important to ensure the performance of geosynthetics, especially where high temperatures are expected. In order to fill this gap, six commercial geosynthetics with different internal structures made of polypropylene (PP), high density polyethylene (HDPE), bitumen and polyvinyl chloride (PVC), or even a combination of some of them have been mechanically tested at mild temperature (20ºC or 23ºC) and at warm temperature (45ºC) before and after specific exposition to air at standardized high temperature in order to simulate 25 years of aging due to oxidation. Besides, for 45ºC tests, an innovative heating system during test for high deformable specimens is proposed. The influence of the combining effect of aging, structure and temperature in the product behavior have been analyzed and discussed, concluding that internal structure is more influential than aging in the mechanical behavior of a geosynthetic versus temperature.

Keywords: geosynthetics, mechanical behavior, temperature, aging, internal structure

Procedia PDF Downloads 47

Authors: Siamak Eskandari, Neda Ebadi

Abstract:

After discovering and using Freon as refrigerant in refrigerators and air conditioners, researchers have been working hard to minimize massive environmental damage caused by this type of systems, including ozone depletion, heat production, and urban warming. However, there is a growing concern for global warming and climate change and its impacts on climates. Although gas air conditioners can provide comfort in short term, there are long-term consequences and effects, including global warming, polar ice melting, sea level rising, rising sea surface temperatures, reduction in seasonal precipitation, tropical storms, and drought. In this theoretical and practical study, Peltier electronic chip was used with no gas in the structure and operation. In fact, cooling and heating are based on bipolar electronics. With an innovative method, Peltier air conditioners provide cooling in warm seasons and heating in cold seasons in buildings. Such a system prevents ambient warming. The problem of air circulation between high buildings in large cities and draught will be considerably resolved through the use of the silent fan in the system. In addition, the system is designed and developed in accordance with international standards such as LEED and Energy Star.

Keywords: energy, Building cooling and heating, peltier, leed, energy star

Procedia PDF Downloads 172

Authors: Debraj Adhikari, Resham Bahadur Thapa, Samudra Lal Joshi, Jason Jinping Du, Sundar Tiwari

Abstract:

The purpose of this study was to keep a record of fruit fly species (Tephritidae: Diptera) in the sweet orange orchards of Sindhuli district, Nepal. Male fruit fly species were trapped and collected fortnightly using para-pheromone lures (methyl eugenol and cue lure) in Steiner traps at 25 orchards starting in March 2019 and continuing until February 2021. During the monitoring period, there was a significant variation in the occurrence of the fruit fly species. Fruit flies were captured in greater numbers during warm and rainy months (June, July, August, September) than during dry and winter months (December, January, February). Higher numbers of fruit flies were trapped in methyl eugenol than cue lure traps. Bactrocera dorsalis, B. zonata were major fruit fly species trapped in the methyl eugenol trap. Whereas, Zeugodacus tau, Z. cucurbitae, Z. scutellaris, and Dacus longicornis were major fruit fly species trapped in the cue lure trap. The findings of this study could be used to develop a long-term pest management strategy for the agro-ecological system.

Keywords: bactrocera, cue lure, methyl eugenol, monitoring, zeugodacus

Procedia PDF Downloads 163

Authors: Rakesh Prajapati, Purvik Patel, Avadhoot Rajurkar

Abstract:

Nowadays, manufacturing industries augment their production lines with modern machining centers backed by CAM software. Several attempts are being made to cut down the programming time for machining complex geometries. Special programs/software have been developed to generate the digital numerical data and to prepare NC programs by using suitable post-processors for different machines. By selecting the tools and manufacturing process then applying tool paths and NC program are generated. More and more complex mechanical parts that earlier were being cast and assembled/manufactured by other processes are now being machined. Majority of these parts require lots of pocketing operations and find their applications in die and mold, turbo machinery, aircraft, nuclear, defense etc. Pocketing operations involve removal of large quantity of material from the metal surface. The modeling of warm cast and clamping a piece of food processing parts which the used of Pro-E and MasterCAM^® software. Pocketing operation has been specifically chosen for toolpath optimization. Then after apply Pocketing toolpath, Multi Tool Selection and Reduce Air Time give the results of software simulation time and experimental machining time.

Keywords: toolpath, part program, optimization, pocket

Procedia PDF Downloads 276