Search results for: temperature factors

Authors: Jaruwan Duangchuen, Siwalak Pathaveerat

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Coconut (Cocos nucifera) belongs to the family Arecaceae. Coconut juice and meat are consumed as food and dessert in several regions of the world. Coconut juice contains low proteins, and arginine is the main amino acid content. Coconut meat is the endosperm of coconut that has nutritional value. It composes of carbohydrate, protein and fat. The objective of this study is utilization of by-products from the virgin coconut oil extraction process by using the skimmed coconut milk as a powder. The skimmed coconut milk was separated from the coconut milk in virgin coconut oil extraction process that consists approximately of protein 6.4%, carbohydrate 7.2%, dietary fiber 0.27 %, sugar 6.27%, fat 3.6 % and moisture content of 86.93%. This skimmed coconut milk can be made to powder for value - added product by using spray drying. The factors effect to the yield and properties of dry skimmed coconut milk in spraying process are inlet, outlet air temperature and the maltodextrin concentration. The percentage of maltodextrin content (15, 20%), outlet air temperature (80 ºC, 85 ºC, 90 ºC) and inlet air temperature (190 ºC, 200 ºC, 210 ºC) were conducted to the skimmed coconut milk spray drying process. The spray dryer was kept air flow rate (0.2698 m3 /s). The result that shown 2.22 -3.23% of moisture content, solubility, bulk density (0.4-0.67g/mL), solubility, wettability (4.04 -19.25 min) for solubility in the water, color, particle size were analyzed for the powder samples. The maximum yield (18.00%) of spray dried coconut milk powder was obtained at 210 °C of temperature, 80°C of outlet temperature and 20% maltodextrin for 27.27 second for drying time. For the amino analysis shown that the high amino acids are Glutamine (16.28%), Arginine (10.32%) and Glycerin (9.59%) by using HPLP method (UV detector).

Keywords: skimmed coconut milk, spray drying, virgin coconut oil process (VCO), maltodextrin

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Authors: Vito Telesca, Giuseppina A. Giorgio, M. Ragosta

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The effects of extreme heat events are increasing in recent years. Humans are forced to adjust themselves to adverse climatic conditions. The impact of weather on human health has become public health significance, especially in light of climate change and rising frequency of devasting weather events (e.g., heat waves and floods). The interest of scientific community is widely known. In particular, the associations between temperature and mortality are well studied. Weather conditions are natural factors that affect the human organism. Recent works show that the temperature threshold at which an impact is seen varies by geographic area and season. These results suggest heat warning criteria should consider local thresholds to account for acclimation to local climatology as well as the seasonal timing of a forecasted heat wave. Therefore, it is very important the problem called ‘local warming’. This is preventable with adequate warning tools and effective emergency planning. Since climate change has the potential to increase the frequency of these types of events, improved heat warning systems are urgently needed. This would require a better knowledge of the full impact of extreme heat on morbidity and mortality. The majority of researchers who analyze the associations between human health and weather variables, investigate the effect of air temperature and bioclimatic indices. These indices combine air temperature, relative humidity, and wind speed and are very important to determine the human thermal comfort. Health impact studies of weather events showed that the prevention is an essential element to dramatically reduce the impact of heat waves. The summer Italian of 2012 was characterized with high average temperatures (con un +2.3°C in reference to the period 1971-2000), enough to be considered as the second hottest summer since 1800. Italy was the first among countries in Europe which adopted tools for to predict these phenomena with 72 hours in advance (Heat Health Watch Warning System - HHWWS). Furthermore, in Italy heat alert criteria relies on the different Indexes, for example Apparent temperature, Scharlau index, Thermohygrometric Index, etc. This study examines the importance of developing public health policies that protect the most vulnerable people (such as the elderly) to extreme temperatures, highlighting the factors that confer susceptibility.

Keywords: heat waves, Italy, local warming, temperature

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Authors: Dolhadi Bin Zainudin

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The study attempts to predict the relationship between influencing factors in the adoption of ISO 9000:2008 and to identify which how these factors play the main role in achieving ISO 9000 standard. A survey using structured questionnaire was employed. A total of 255 respondents from 255 small and medium enterprises participated in this study. With regards to influencing factors, a discriminant analysis was conducted and the results showed that three out of nine critical success factors is statistically significant between ISO 9000:2008 and non-ISO 9000 certified companies which are communication for quality, information and analysis and organizational culture.

Keywords: ISO 9000, quality management, factors, small and medium enterprise, Malaysia, influencing factors

Procedia PDF Downloads 315

Authors: Jiří Kubásek, Peter Minárik, Klára Hosová, Stanislav Šašek, Jozef Veselý, Jitka Stráská, Drahomír Dvorský, Dalibor Vojtěch, Miloš Janeček

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Mg-2Y-2Gd-1Ca and Mg-4Y-4Gd-2Ca alloys were processed by extrusion or equal channel angular pressing (ECAP) to analyse the effect of the microstructure on ignition temperature, mechanical properties and corrosion resistance. The alloys are characterized by good mechanical properties and exceptionally high ignition temperature, which is a critical safety measure. The effect of extrusion and ECAP on the microstructure, mechanical properties and ignition temperature was studied. The obtained results indicated a substantial effect of the processing conditions on the average grain size, the recrystallized fraction and texture formation. Both alloys featured a high strength, depending on the composition and processing condition, and a high ignition temperature of ≈1100 °C (Mg-4Y-4Gd-2Ca) and ≈950 °C (Mg-2Y-2Gd-1Ca), which was attributed to the synergic effect of Y, Gd and Ca oxides, with the dominant effect of Y₂O₃. The achieved combination of enhanced mechanical properties and the ignition temperature makes these alloys a prominent candidate for aircraft applications.

Keywords: magnesium alloys, enhanced ignition temperature, mechanical properties, ECAP

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Authors: Kenza Maher, Yahya Zakaria, Noora S. Al-Jaidah

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Temperature is a critical parameter for lithium-ion battery performance, life, and safety. In this study, four commercially available 18650 lithium-ion cells from four different manufacturers are subjected to accelerated cycle aging for up to 500 cycles at two different temperatures (25°C and 45°C). The cells are also calendar-aged at the same temperatures in both charged and discharged states for 6 months to investigate the effect of aging and temperature on capacity fade and state of health. The results showed that all battery cells demonstrated good cyclability and had a good state of health at both temperatures. However, the capacity loss and state of health of these cells are found to be dependent on the cell chemistry and aging conditions, including temperature. Specifically, the capacity loss is found to be higher at the higher aging temperature, indicating the significant impact of temperature on the aging of lithium-ion batteries.

Keywords: lithium-ion battery, aging mechanisms, cycle aging, calendar aging.

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Authors: Pornsiri Kaewpradit, Chalisa Pourneaw

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Temperature control improvement of a membrane reactor with exothermic and reversible esterification reaction is studied in this work. It is well known that a batch membrane reactor requires different control strategies from a continuous one due to the fact that it is operated dynamically. Due to the effect of the operating temperature, the suitable control scheme has to be designed based reliable predictive model to achieve a desired objective. In the study, the optimization framework has been preliminary formulated in order to determine an optimal temperature trajectory for maximizing a desired product. In model predictive control scheme, a set of predictive models have been initially developed corresponding to the possible operating points of the system. The multiple predictive control moves have been further calculated on-line using the developed models corresponding to current operating point. It is obviously seen in the simulation results that the temperature control has been improved compared to the performance obtained by the conventional predictive controller. Further robustness tests have also been investigated in this study.

Keywords: model predictive control, batch reactor, temperature control, membrane reactor

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Authors: Richard G. Carranza, Juan Ospina

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The fin efficiency for a helical fin with a fixed fin tip (or arbitrary) temperature boundary condition is presented. Firstly, the temperature profile throughout the fin is determined via an energy balance around the fin itself. Secondly, the fin efficiency is formulated by integrating across the entire surface of the helical fin. An analytical expression for the fin efficiency is presented and compared with the literature for accuracy.

Keywords: efficiency, fin, heat, helical, transfer

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Authors: Samaneh serraj

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Listening anxiety has a detrimental effect on language learners. Through a qualitative study on Iranian EFL learners several factors were identified as having influence on their listening anxiety. These factors were divided into three categories, i.e. individual factors (nerves and emotionality, using inappropriate strategies and lack of practice), input factors (lack of time to process, lack of visual support, nature of speech and level of difficulty) and environmental factors (instructors, peers and class environment).

Keywords: listening Comprehension, Listening Anxiety, Foreign language learners

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Authors: Khaled Alshamari

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Synthesized partially phosphorylated polyvinyl phosphate derivative (PPVP) was functionalized to extract Zirconium (IV) from Egyptian zircon sand. The specifications for the PPVP composite were approved effectively via different techniques, namely, FT-IR, XPS, BET, EDX, TGA, HNMR, C-NMR, GC-MS, XRD and ICP-OES analyses, which demonstrated a satisfactory synthesis of PPVP and zircon dissolution from Egyptian zircon sand. Factors controlling parameters, such as pH values, shaking time, initial zirconium concentration, PPVP dose, nitrate ions concentration, co-ions, temperature and eluting agents, have been optimized. At 25 ◦C, pH 0, 20 min shaking, 0.05 mol/L zirconium ions and 0.5 mol/L nitrate ions, PPVP has an exciting preservation potential of 195 mg/g, equivalent to 390 mg/L zirconium ions. From the extraction–distribution isotherm, the practical outcomes of Langmuir’s modeling are better than the Freundlich model, with a theoretical value of 196.07 mg/g, which is more in line with the experimental results of 195 mg/g. The zirconium ions adsorption onto the PPVP composite follows the pseudo-second-order kinetics with a theoretical capacity value of 204.08 mg/g. According to thermodynamic potential, the extraction process was expected to be an exothermic, spontaneous and beneficial extraction at low temperatures. The thermodynamic parameters ∆S (−0.03 kJ/mol), ∆H (−12.22 kJ/mol) and ∆G were also considered. As the temperature grows, ∆G values increase from −2.948 kJ/mol at 298 K to −1.941 kJ/mol at 338 K. Zirconium ions may be eluted from the working loaded PPVP by 0.025M HNO₃, with a 99% efficiency rate. It was found that zirconium ions revealed good separation factors towards some co-ions such as Hf⁴+ (28.82), Fe³+ (10.64), Ti⁴+ (28.82), V⁵+ (86.46) and U⁶+ (68.17). A successful alkali fusion technique with NaOH flux followed by the extraction with PPVP is used to obtain a high-purity zirconia concentrate with a zircon content of 72.77 % and a purity of 98.29%. As a result of this, the improved factors could finally be used.

Keywords: zirconium extraction, partially phosphorylated polyvinyl phosphate (PPVP), acidic medium, zircon

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Authors: Abegunde Linda, Adedeji Oluwatola

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It has become increasingly evident that large developments influence the climate within the immediate region and there are concerns that rising temperatures over developed areas could have negative impact and increase living discomfort within city boundaries. Temperature trends in Ibadan city have received minor attention, yet the area has experienced heavy urban expansion between 1972 and 2014. This research aims at examining the impact of landuse change on temperature knowing that the built environment absorbs and stores solar energy, the temperature in cities can be several degrees higher than in adjacent rural areas. This is known as the urban heat island (UHI) effect. The Landsat imagery were used to examine the landuse change for a time period of 42years (1972-2014) and Land surface temperature (LST) was obtained by converting the thermal band to a surface temperature map and zonal statistic analyses was further used to examine the relationship between landuse and temperature emission. The results showed that the settlement area increased by 200km2 while the area covered by vegetation also reduced to about 42.6% during the study period. The spatial and temporal trends of temperature are related to the gradual change in urban landcover and the settlement area has the highest emission of land surface temperature. This research provides useful insight into the temporal behavior of the Ibadan city.

Keywords: landuse, LST, remote sensing, UHI

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Authors: Justin Orimisan Ijigbade

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The study was conducted to assess the effect of climate variability on honeybee’s production in Ondo State, Nigeria. Multistage sampling technique was employed to collect the data from 60 beekeepers across six Local Government Areas in Ondo State. Data collected were subjected to descriptive statistics and multiple regression model analyses. The results showed that 93.33% of the respondents were male with 80% above 40 years of age. Majority of the respondents (96.67%) had formal education and 90% produced honey for commercial purpose. The result revealed that 90% of the respondents admitted that low temperature as a result of long hours/period of rainfall affected the foraging efficiency of the worker bees, 73.33% claimed that long period of low humidity resulted in low level of nectar flow, while 70% submitted that high temperature resulted in improper composition of workers, dunes and queen in the hive colony. The result of multiple regression showed that beekeepers’ experience, educational level, access to climate information, temperature and rainfall were the main factors affecting honey bees production in the study area. Therefore, beekeepers should be given more education on climate variability and its adaptive strategies towards ensuring better honeybees production in the study area.

Keywords: climate variability, honeybees production, humidity, rainfall and temperature

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Authors: Farhad Forouharmajd, Hossein Ebrahimi, Siamak Pourabdian

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Introduction: Prevalent use of cell phones (mobile phones) has led to increasing worries about the effect of radiofrequency waves on the physiology of human body. This study was done to determine different reactions of the temperatures in different depths of brain tissue in confronting with radiofrequency waves of cell phones. Methodology: This study was an empirical research. A cow's brain tissue was placed in a compartment and the effects of radiofrequency waves of the cell phone was analyzed during confrontation and after confrontation, in three different depths of 2, 12, and 22 mm of the tissue, in 4 mm and 4 cm distances of the tissue to a cell phone, for 15 min. Lutron thermometer was used to measure the tissue temperatures. Data analysis was done by Lutron software. Findings: The rate of increasing the temperature at the depth of 22 mm was higher than 2 mm and 12mm depths, during confrontation of the brain tissue at the distance of 4 mm with the cell phone, such that the tissue temperatures at 2, 12, and 22 mm depths increased by 0.29 ˚C, 0.31 ˚C, and 0.37 ˚C, respectively, relative to the base temperature (tissue temperature before confrontation). Moreover, the temperature of brain tissue at the distance of 4 cm by increasing the tissue depth was more than other depths. Increasing the tissue temperature also existed by increasing the brain tissue depth after the confrontation with the cell phone. The temperature of the 22 mm depth increased with higher speed at the time confrontation. Conclusion: Not only radiofrequency waves of cell phones increased the tissue temperature in all the depths of the brain tissue, but also the temperature due to radiofrequency waves of the cell phone was more at the depths higher than 22 mm of the tissue. In fact, the thermal effect of radiofrequency waves was higher in higher depths.

Keywords: mobile phone, radio frequency waves, brain tissue, temperature

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Authors: Ali Alzeyadi, Edward Loffill, Rafid Alkhaddar Ali Alattabi

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Phosphate, ammonium, and nitrates are forms of nutrients; they are released from different sources. High nutrient levels contribute to the eutrophication of water bodies by accelerating the extraordinary growth of algae. Recently, many filtration and treatment systems were developed and used for different removal processes. Due to enhanced operational aspects for the up-flow, continuous, granular Media filter researchers became more interested in further developing this technology and its performance for nutrient removal from wastewater. Environmental factors significantly affect the filtration process performance, and understanding their impact will help to maintain the nutrient removal process. Phosphate removal by phosphate sorption materials PSMs and nitrogen removal biologically are the methods of nutrient removal that have been discussed in this paper. Hence, the focus on the factors that influence these processes is the scope of this work. The finding showed the presence of factors affecting both removal processes; the size, shape, and roughness of the filter media particles play a crucial role in supporting biofilm formation. On the other hand, all of which are effected on the reactivity of surface between the media and phosphate. Many studies alluded to factors that have significant influence on the biological removal for nitrogen such as dissolved oxygen, temperature, and pH; this is due to the sensitivity of biological processes while the phosphate removal by PSMs showed less affected by these factors. This review work provides help to the researchers in create a comprehensive approach in regards study the nutrient removal in up flow filtration systems.

Keywords: nitrogen biological treatment, nutrients, psms, upflow filter, wastewater treatment

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Authors: Khater N., Rahmine S., Bougoffa C., Bouguenna T., Ouanes H.

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Moringa oleifera L. species is considered one of the most useful trees in the world, possessing many interesting properties that make it of great scientific interest. It has been described as the miracle tree, the tree of a thousand virtues, the tree of life and God's gift to man. The present study aims to introduce, produce, and develop Moringa Oleifera as a species with high ecological potential (resistance to biotic and abiotic stresses and productivity), high added value, and multiple virtues. The aim of this work is to study the germination potential of this species under different temperature conditions. In this study, the germination assay was tested in two different temperature ranges: internal (laboratory ambient temperature between 22°c and 25°c) and external (seasonal temperature between 4°c and 8°c). Morphological and physiological analyses were carried out by Shoot length (SL), root length (RL), diameter at the crown (DC), fresh weight of shoots (FWS), fresh weight of roots (FWR), dry weight of shoots (DWS) and dry weight of roots (DWS). For all these variables, the results of the study reveal a significant difference between the two temperature intervals, with a high germination rate of 81. 81% and plant growth was rapid (7cm during 24h) in the laboratory temperature; in contrast to the external temperatures, a germination rate value of around 27% was recorded, and germination took place after 20 days of sowing, with slower plant growth. The results obtained show that a temperature greater than or equal to 25° is the ideal temperature for the germination and growth of moringa seeds and has a positive influence on the speed and percentage of germination.

Keywords: moringa oleifera, temperature, germination rate, growth, biomass

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Authors: Duy Cuong Nguyen, Ali Makke, Guillaume Montay

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This work presents an improved single fiber pull-out test for fiber/matrix interface characterization. This test has been used to study the Inter-Facial Shear Strength ‘IFSS’ of hemp fibers reinforced polypropylene (PP). For this aim, the fiber diameter has been carefully measured using a tomography inspired method. The fiber section contour can then be approximated by a circle or a polygon. The results show that the IFSS is overestimated if the circular approximation is used. The Influence of the molding temperature on the IFSS has also been studied. We find a molding temperature of 183°C leads to better interface properties. Above or below this temperature the interface strength is reduced.

Keywords: composite, hemp, interface, pull-out, processing, polypropylene, temperature

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Authors: Nalini C. Iyer, Shraddha H., Anagha B. Varahamurthy, Dikshith C. S., Ishwar G. Kubasad, Vinayak I. Karalatti, Pavan B. Mulimani

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The current scenario of the pandemic due to COVID-19 has led to the awareness among the people to avoid unneces-sary contact in public places. There is a need to avoid contact with physical objects to stop the spreading of infection. The contactless feature has to be included in the systems in public places wherever possible. For example, attendance monitoring systems with fingerprint biometric can be replaced with a contactless feature. One more important protocol followed in the current situation is temperature monitoring and screening. The paper describes an attendance system with a contactless feature and temperature screening for the university. The system displays a QR code to scan, which redirects to the student login web page only if the location is valid (the location where the student scans the QR code should be the location of the display of the QR code). Once the student logs in, the temperature of the student is scanned by the contactless temperature sensor (mlx90614) with an error of 0.5°C. If the temperature falls in the range of the desired value (range of normal body temperature), then the attendance of the student is marked as present, stored in the database, and the door opens automatically. The attendance is marked as absent in the other case, alerted with the display of temperature, and the door remains closed. The door is automated with the help of a servomotor. To avoid the proxy, IR sensors are used to count the number of students in the classroom. The hardware system consisting of a contactless temperature sensor and IR sensor is implemented on the microcontroller, NodeMCU.

Keywords: NodeMCU, IR sensor, attendance monitoring, contactless, temperature

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Authors: Flavia Cordeiro, Fabio Silva, Alvaro Eiras, Jose Luiz Acebal

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Aedes aegypti is present in the tropical and subtropical regions of the world and is a vector of several diseases such as dengue fever, yellow fever, chikungunya, zika etc. The growth in the number of arboviruses cases in the last decades became a matter of great concern worldwide. Meteorological factors like mean temperature and precipitation are known to influence the infestation by the species through effects on physiology and ecology, altering the fecundity, mortality, lifespan, dispersion behaviour and abundance of the vector. Models able to describe the dynamics of the vector population size should then take into account the meteorological variables. The relationship between meteorological factors and the population dynamics of Ae. aegypti adult females are studied to provide a good set of predictors to model the dynamics of the mosquito population size. The time-series data of capture of adult females of a public health surveillance program from the city of Lavras, MG, Brazil had its association with precipitation, humidity and temperature analysed through a set of statistical methods for time series analysis commonly adopted in Signal Processing, Information Theory and Neuroscience. Cross-correlation, multicollinearity test and whitened cross-correlation were applied to determine in which time lags would occur the influence of meteorological variables on the dynamics of the mosquito abundance. Among the findings, the studied case indicated strong collinearity between humidity and precipitation, and precipitation was selected to form a pair of descriptors together with temperature. In the techniques used, there were observed significant associations between infestation indicators and both temperature and precipitation in short, mid and long terms, evincing that those variables should be considered in entomological models and as public health indicators. A descriptive model used to test the results exhibits a strong correlation to data.

Keywords: Aedes aegypti, cross-correlation, multicollinearity, meteorological variables

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Authors: Faith Maina

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Slender leaf (Crotalaria brevidens and Crotalaria ochroleuca), African indigenous vegetables, are an important source of nutrients, income and traditional medicines in Kenya. However, their production is constrained by poor quality seed, due to lack of standardized agronomic and storage practices. Factors that affect the quality of seed in storage include the duration of storage, seed moisture, temperature, relative humidity, oxygen pressure during storage, diseases, and pests. These factors vary with the type of storage method used. The aim of the study was to investigate the effect of various storage methods on seed quality of slender leaf and recommend the best methods of seed storage to the farmers in Western Kenya. Seeds from various morphotypes of slender leaf that had high germination percentage (90%) were stored in pots, jars, brown paper bags and polythene bags in Kakamega and Siaya. Other seeds were also stored in a freezer at the University of Eldoret. In Kakamega County average room temperature was 23°C and relative humidity was 85% during the storage period of May to July 2006. Between December and February 2006 the average room temperature was 26°C while relative humidity was 80% in the same county. In Siaya County, the average room temperature was 25°C and relative humidity was 80% during storage period of May to July 2006. In the same county, the average temperature was 28°C and relative humidity 65% during the period of December and February 2006. Storage duration was 90 days for each season. Seed viability and vigour, was determined for each storage method. Data obtained from storage experiments was subjected to ANOVA and T-tests using Statistical Analysis Software (SAS). Season of growth and storage methods significantly influenced seed quality in Kakamega and Siaya counties. Seeds from the long rains season had higher seed quality than those grown during the short rains season. Generally, seeds stored in pots, brown paper bags, jars and freezer had higher seed quality than those stored in polythene bags. It was concluded that in order to obtain high-quality seeds farmers should store slender leaf seeds in pots or brown paper bags or plastic jars or freezer.

Keywords: Crotalaria sp, seed, quality, storage

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Authors: Jose Cristiano Pereira, Gilson Brito Alves Lima

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Ergonomics is a key factor affecting the operational safety and quality in the aircraft engine manufacturing industry and evidence shows that the lack of attention to it can increase the risk of accidents. In order to emphasize the importance of ergonomics, this paper systematically reviews the critical processes used in the aircraft engine production industry with focus on the ergonomic factors. about the subject to identify key ergonomic factors. Experts validated the factors and used AHP to rank the factors in order of significance. From the six key risk factors identified, the ones with the highest weight are psychological demand followed by understanding of operational side. These factors suggest that measures must be taken to improve ergonomic factors, quality and safety in the manufacturing of aircraft engines.

Keywords: ergonomics, safety, aviation, aircraft engine production

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Authors: Sara Kamalisiahroudi, Jun Huang, Zhe Li, Jianbo Zhang

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Two types of commercial cylindrical lithium ion batteries (Panasonic 3.4 Ah NCR-18650B and Samsung 2.9 Ah INR-18650), were investigated experimentally. The capacities of these samples were individually measured using constant current-constant voltage (CC-CV) method at different ambient temperatures (-10 ℃, 0 ℃, 25 ℃). Their internal resistance was determined by electrochemical impedance spectroscopy (EIS) and pulse discharge methods. The cells with different configurations of parallel connection NCR-NCR, INR-INR and NCR-INR were charged/discharged at the aforementioned ambient temperatures. The results showed that the difference of internal resistance between cells much more evident at low temperatures. Furthermore, the parallel connection of NCR-NCR exhibits the most uniform temperature distribution in cells at -10 ℃, this feature is quite favorable for the safety of the battery pack.

Keywords: batteries in parallel connection, internal resistance, low temperature, temperature difference, current distribution

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Authors: Zakaria Aketouane, Mustapha Malha, Abdellah Bah, Omar Ansari, Mohamed Asbik

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The present paper deals with the thermal performance of a hollow-brick filled with Phase Change Material (PCM). The main objective is to study the effect of percentage and melting temperature of the PCM on the thermal inertia and internal surface temperature of the hollow-brick. A numerical model based on the heat transfer equation and the apparent heat capacity method has been validated using experimental study from the literature. The results show that increasing the percentage of the PCM has a significant effect on time lag and decrement factor that define the thermal inertia; the internal temperature is reduced by 1.36°C to 5.39°C for a percentage from 11% to 71% in comparison to a brick without PCM. In addition, an appropriate melting temperature of 37°C has been deduced for the horizontal wall orientation in Rabat in comparison to 27°C and 47°C.

Keywords: appropriate melting temperature, decrement factor, phase change material, thermal inertia, time lag

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Authors: Abir S. AL-Harrasi, Eyad B. AL-Zadjali, Zahran S. AL-Salti

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Entrepreneurship has captured the attention of policy-makers, educators and researchers in the last few decades. It has been regarded as a main driver for economic growth, development and employment generation in many countries worldwide. However, scholars have not agreed on the key factors that impact entrepreneurial intention. This study attempts, through an extensive literature review, to provide a holistic view and a more comprehensive understanding of the key factors that lead university undergraduate students to become entrepreneurs. A systematic literature review is conducted and several scientific articles and reports have been examined. The results of this study indicate that there are four main sets of factors: the personality-traits factors, contextual factors, motivational factors, and personal background factors. This research will serve as a base for future studies and will have valuable implications for policy makers and educators.

Keywords: entrepreneurship, entrepreneurial intention, literature review, economic growth

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Authors: Omid Ghaffarzadeh Mollabashi, Sara Khorshidi, Hossein Kermanian Seyed, Majid Zabihzadeh

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The main problem that hinders the intensive use of non-wood raw materials in papermaking industry is the environmental pollution caused by black liquor. As a matter of fact, black liquor of nonwood pulping is discharged to the environment due to the lack of recovery. Traditionally, NaOH pulping produces Na-based black liquor that may increase soil erosion and reduce soil permeability. With substitution of KOH/NH4OH with NaOH as the cooking liquor, K and N can act as a soil fertilizer while offering an environmentally acceptable disposal alternative. For this purpose, rice straw samples were pulped under the following conditions; Constant factors were: straw weight: 100 gram (based on oven dry), liquor to straw ratio 7:1 and maximum temperature, 170 and 180 ºC. Variable factors for KOH cooks were: KOH dosage of 14, 17 and %20 on oven dry of straw and times at maximum temperature of 60 and 90 minutes. For KOH-NH4OH cooks, KOH dosage of 5 and %10 and NH4OH dosage of 25 and %35, both based as oven dry of straw were applied. Besides, time at maximum temperature was 90 minutes. Yield ranges of KOH and KOH-NH4OH pulp samples were obtained from 37.28 to 48.62 and 45.63 to 48.08 percent, respectively. In addition, Kappa number ranged from 21.91 to 29.85 and 55.15 to 56.25, respectively. In comparison with soda, soda-AQ, cold soda, kraft, EDA (dissolving), De-Ethylene Glycol (dissolving), burst and tensile index for KOH pulp was more in similar cooking condition. With an exception of soda pulps, tear index of the mentioned pulp is more than all compared treatments. Therefore, it can be resulted that KOH pulping method is an appropriate choice for making paper of the rice straw. Also, compared to KOH-NH4OH, KOH pulping method is more appropriate choice because of better pulping results.

Keywords: environmentally friendly process, rice straw, NH4OH-KOH pulping, pulp properties

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Authors: Yadchol Tawetanawanich

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Depression of elderly is a mental health problem that impacts tremendously on the elderly themselves, their family, and society. the purposes of this descriptive research were to examine prevalence rate of elderly depression and to study factors related to depression in elderly including 1) individual factors: sex, education, marital status, 2) economic factors: occupation, adequate income 3) health factors: chronic illnesses , disability, 4) social factors: family relationship, community relationship, 5) knowledge of depression, and 6) self-care behavior. The subject in this study included 273 elderly in Ladboakao sub-district, Banpong district, Ratchaburi province, Thailand. Data were collected through questionnaires and were analyzed using percentage, mean, standard deviation, chi-square, and one-way ANOVA. The results of the study revealed that: The prevalence rate of elderly depression were 21.61%, factors included economic factors, health factors, knowledge about depression, and self-care behavior were statistically significant positively related to depression of elderly (p<0.05), but individual factors and social factors were not significantly related to depression. It is also important for nurses to assess factors related to depression of the elderly in order to develop the model of care and use self-care strategies to contribute the positive outcomes.

Keywords: associated factors, depression, elderly, self-care

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Authors: Hongshan Guo

Abstract:

Ground-source heat pumps provide stable and reliable heating and cooling when designed properly. The confounding effect of the borehole depth for a GSHP system, however, is rarely taken into account for any optimization: the determination of the borehole depth usually comes prior to the selection of corresponding system components and thereafter any optimization of the GSHP system. The depth of the borehole is important to any GSHP system because the shallower the borehole, the larger the fluctuation of temperature of the near-borehole soil temperature. This could lead to fluctuations of the coefficient of performance (COP) for the GSHP system in the long term when the heating/cooling demand is large. Yet the deeper the boreholes are drilled, the more the drilling cost and the operational expenses for the circulation. A controller that reads different building load profiles, optimizing for the smallest costs and temperature fluctuation at the borehole wall, eventually providing borehole depth as the output is developed. Due to the nature of the nonlinear dynamic nature of the GSHP system, it was found that between conventional optimal controller problem and model predictive control problem, the latter was found to be more feasible due to a possible history of both the trajectory during the iteration as well as the final output could be computed and compared against. Aside from a few scenarios of different weighting factors, the resulting system costs were verified with literature and reports and were found to be relatively accurate, while the temperature fluctuation at the borehole wall was also found to be within acceptable range. It was therefore determined that the MPC is adequate to optimize for the investment as well as the system performance for various outputs.

Keywords: geothermal borehole, MPC, dynamic modeling, simulation

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Authors: Z. O. Apotiola, J. F. Fashakin

Abstract:

A study was conducted to investigate the storage stability of Mr Chef and Annapurna salts. The salts were bought from Mile 12 market in Lagos State and were stored for a period of six months. The stability of the iodine content was then investigated by storing some at ambient temperature (24-30oC) and some at atmospheric temperature (21-35 oC), and from each storage condition, a sample each was taken every month to analyze for the iodine and moisture contents. The result shows that there was a significant difference between Mr Chef and the standard and Annapurna and the standard. The iodine content of Mr Chef stored at ambient and atmospheric temperature decreases progressively from 48.70±0.00-37.00±0.00 and 47.60±0.00-11.60±0.00 respectively. And that of Annapurna at both ambient and atmospheric temperature also decreases progressively from 47.60±0.00-36.60±0.00 and 47.60±0.00-10.60±0.00 respectively. Also, the moisture content of both salts at the zero month to the sixth month both at room temperature and atmospheric temperature increases from 1.11±0.00-1.70±0.00 and 1.11±0.00-2.40±0.00 respectively. The results of the heavy metals shows that only Copper, Zinc and Cobalt were detected at the first and the sixth month in both Mr Chef and Annapurna which ranges from 0.15±0.00-0.38±0.00 and 0.18±0.00 - 3.50±0.00 respectively. Hence, the stability of iodine in salt is influenced by the storage conditions it is subjected to and the length of time it is been stored.

Keywords: salt, iodine, stability, ambient, atmospheric temperature

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Authors: Yogesh Shukla

Abstract:

Many attempts have been made to study temperature distribution problem in human tissues under normal environmental and physiological conditions at constant arterial blood temperature. But very few attempts have been made to investigate temperature distribution in human tissues under different arterial blood temperature. In view of above, a finite element model has been developed to unsteady temperature distribution in dermal region in human body. The model has been developed for one dimension unsteady state case. The variation in parameters like thermal conductivity, blood mass flow and metabolic activity with respect to position and time has been incorporated in the model. Appropriate boundary conditions have been framed. The central difference approach has been used in space variable and trapezoidal rule has been employed a long time variable. Numerical results have been obtained to study relationship among temperature and time.

Keywords: rate of metabolism, blood mass flow rate, thermal conductivity, heat generation, finite element method

Procedia PDF Downloads 332

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: M. Javanmard

Abstract:

This study was aimed at analyzing the effects of packaging (MAP) and preservation conditions on the packaged fresh walnut kernel quality. The central composite plan was used for evaluating the effect of oxygen (0–10%), carbon dioxide (0-10%), and temperature (4-26 °C) on qualitative characteristics of walnut kernels. Also, the response level technique was used to find the optimal conditions for interactive effects of factors, as well as estimating the best conditions of process using least amount of testing. Measured qualitative parameters were: peroxide index, color, decreased weight, mould and yeast counting test, and sensory evaluation. The results showed that the defined model for peroxide index, color, weight loss, and sensory evaluation is significant (p < 0.001), so that increase of temperature causes the peroxide value, color variation, and weight loss to increase and it reduces the overall acceptability of walnut kernels. An increase in oxygen percentage caused the color variation level and peroxide value to increase and resulted in lower overall acceptability of the walnuts. An increase in CO₂ percentage caused the peroxide value to decrease, but did not significantly affect other indices (p ≥ 0.05). Mould and yeast were not found in any samples. Optimal packaging conditions to achieve maximum quality of walnuts include: 1.46% oxygen, 10% carbon dioxide, and temperature of 4 °C.

Keywords: shelled walnut, MAP, quality, storage temperature

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Authors: Lee Sunghyoun, Yu Byeongkee, Kim Hyuckjoo, Yun Namkyu, Jung Jongcheon

Abstract:

Most of the recent on-sale oyster mushrooms are raised in a oyster mushroom house, in which the necessary adjustment of growing condition is feasible. The rationale for such artificial growing is the impossibility of successive cultivation in the case of a natural cultivation due to external weather conditions. A oyster mushroom house adopts an equipment called growing bed, laying one growing bed upon another in a multi-column fashion, growing and developing the mushrooms on the respective equipments. The indispensable environment management factors of mushroom cultivation are temperature, humidity, and CO2; on which an appropriate regulation of the three requisites is a necessitated condition for the sake of the total output’s increase. However, due to the multiple layers of growing bed’s disturbance on air circulation, a oyster mushroom house’s internal environmental uniformity meets with considerable instability. This research presents a technology which assures the facilitation of environment regulation over all the internal space of a oyster mushroom house, irrespective of its location. The research staff reinforced the oyster mushroom house’s insulation in order to minimize the external environment’s influence on the oyster mushroom house’s internal environment and installed circulation fan to improve the oyster mushroom house’s interior environmental uniformity. Also, the humidifier nozzle’s position was set to prevent dew condensation when humidifying. As a result, a highly sophisticated management over all the oyster mushroom house‘s internal space was realized with the temperature of 0.2~1.3℃, and the relative humidity of 2~7% at the cultivating stage of mushroom’s growth. Therefore, to maximize oyster mushroom house‘s internal environmental uniformity, it can be concluded that consideration of various factors such as insulation reinforcement, decision on the humidifier nozzle’s location, disposition of circulation fan’s installation and the direction of wind discharge is needed.

Keywords: mushroom growing facility, environmental uniformity, temperature, relative humidity, CO2 concentration

Procedia PDF Downloads 513