Search results for: growth temperature

Authors: Safar Ghaedrahmati, Leila Soltani

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Population centralization in urban area and metropolitans, especially in developing countries such as Iran increase metropolitan's problems. For few decades, the population of cities in developing countries, including Iran had a higher growth rate than the total growth rate of countries’ population. While in developed countries, the development of the big cities began decades ago and generally allowed for controlled and planned urban expansion, the opposite is the case in developing countries, where rapid urbanization process is characterized by an unplanned existing urban expansion. The developing metropolitan cities have enormous difficulties in coping both with the natural population growth and the urban physical expansion. Iranian cities are usually the heart of economic and cultural changes that have occurred after the Islamic revolution in 1979. These cities are increasingly having impacts via political–economical arrangement and chiefly by urban management structures. Structural features have led to the population growth of cities and urbanization (in number, population and physical frame) and the main problems in them. On the other hand, the lack of birth control policies and the deceptive attractions of cities, particularly big cities, and the birth rate has shot up, something which has occurred mainly in rural regions and small cities. The population of Iran has increased rapidly since 1956. The 1956 and 1966 decennial censuses counted the population of Iran at 18.9 million and 25.7 million, respectively, with a 3.1% annual growth rate during the 1956–1966 period. The 1976 and 1986 decennial censuses counted Iran’s population at 33.7 and 49.4 million, respectively, a 2.7% and 3.9% annual growth rate during the 1966–1976 and 1976–1986 periods. The 1996 count put Iran’s population at 60 million, a 1.96% annual growth rate from 1986–1996 and the 2006 count put Iran population at 72 million. A recent major policy of urban economic and industrial decentralization is a persistent program of the government. The policy has been identified as a result of the massive growth of Tehran in the recent years, up to 9 million by 2010. Part of the growth of the capitally resulted from the lack of economic opportunities elsewhere and in order to redress the developing primacy of Tehran and the domestic pressures which it is undergoing, the policy of decentralization is to be implemented as quickly as possible. Type of research is applied and method of data collection is documentary and methods of analysis are; population analysis with urban system analysis and urban distribution system

Keywords: population centralization, cities of Iran, urban centralization, urban system

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Authors: Hyun-Jong Choi, Minjun Kwak, Doo-Won Seo, Sang-Kuk Woo, Sun-Dong Kim

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Solid Oxide Cell(SOC) systems can contribute to the transition to the hydrogen society by utilized as a power and hydrogen generator by the electrochemical reaction with high efficiency at high operation temperature (>750 ℃). La1-xSrxCo1-yFeyO3, which is an air electrode, is occurred stability degradations due to reaction and delamination with yittria stabilized zirconia(YSZ) electrolyte in a water electrolysis mode. To complement this phenomenon SOCs need gadolinium doped ceria(GDC) buffer layer between electrolyte and air electrode. However, GDC buffer layer requires a high sintering temperature and it causes a reaction with YSZ electrolyte. This study carried out low temperature sintering of GDC layer by applying Cu-oxide as a sintering aid. The effect of a copper additive as a sintering aid to lower the sintering temperature for the construction of solid oxide fuel cells (SOFCs) was investigated. GDC buffer layer with 0.25-10 mol% CuO sintering aid was prepared by reacting GDC power and copper nitrate solution followed by heating at 600 ℃. The sintering of CuO-added GDC powder was optimized by investigating linear shrinkage, microstructure, grain size, ionic conductivity, and activation energy of CuO-GDC electrolytes at temperatures ranging from 1100 to 1400 ℃. The sintering temperature of the CuO-GDC electrolyte decreases from 1400 ℃ to 1100 ℃ by adding the CuO sintering aid. The ionic conductivity of the CuO-GDC electrolyte shows a maximum value at 0.5 mol% of CuO. However, the addition of CuO has no significant effects on the activation energy of GDC electrolyte. GDC-LSCF layers were co-sintering at 1050 and 1100 ℃ and button cell tests were carried out at 750 ℃.

Keywords: Co-Sintering, GDC-LSCF, Sintering Aid, solid Oxide Cells

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Authors: Emmanuel Dele Balogun

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This paper analyzes, using descriptive statistics and econometrics data which span the period 1981 to 2014 to gauge the effects of trade policy incentives on economic growth in Nigeria. It argues that the provided incentives penalize economic growth during pre-trade liberalization eras, but stimulated a rapid increase in total factor productivity during the post-liberalization period of 2000 to 2014. The trend analysis shows that Nigeria maintained high tariff walls in economic regulation eras which became low in post liberalization era. The protections were in favor of infant industries, which were mainly appendages of multinationals but against imports of competing food and finished consumer products. The trade openness index confirms the undue exposure of Nigeria’s economy to the vagaries of international market shocks; while banking sector recapitalization and new listing of telecommunications companies deepened the financial markets in post-liberalization era. The structure of economic incentives was biased in favor of construction, trade and services, but against the real sector despite protectionist policies. Total Factor Productivity (TFP) estimates show that the Nigerian economy suffered stagnation in pre-liberalization eras, but experienced rapid growth rates in post-liberalization eras. The regression results relating trade policy incentives to TFP growth rate yielded a significant but negative intercept suggesting that a non-interventionist policy could be detrimental to economic progress, while protective tariff which limits imports of competing products could spur productivity gains in domestic import substitutes beyond factor growth with market liberalization. The main constraint to the effectiveness of trade policy incentives is the failure of benefiting industries to leverage on the domestic factor endowments of the nation. This paper concludes that there is the need to review the current economic transformation strategies urgently with a view to provide policymakers with a better understanding of the most viable options that could make for rapid success.

Keywords: economic growth, macroeconomic incentives, total factor productivity, trade policies

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Authors: Renée M. Ripken, Johannes G. E. Gardeniers, Séverine Le Gac

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Controlling the multiphase behavior of aqueous biomass mixtures is essential when working in the biomass conversion industry. Here, the vapor/liquid equilibria (VLE) of ethylene glycol, glycerol, and xylitol were studied for temperatures between 25 and 200 °C and pressures of 1 to 10 bar. These experiments were performed in a microfluidic platform, which exhibits excellent heat transfer properties so that equilibrium is reached fast. Firstly, the saturated vapor pressure as a function of the temperature and the substrate mole fraction of the substrate was calculated using AspenPlus with a Redlich-Kwong-Soave Boston-Mathias (RKS-BM) model. Secondly, we developed a high-pressure and high-temperature microfluidic set-up for experimental validation. Furthermore, we have studied the multiphase flow pattern that occurs after the saturation temperature was achieved. A glass-silicon microfluidic device containing a 0.4 or 0.2 m long meandering channel with a depth of 250 μm and a width of 250 or 500 μm was fabricated using standard microfabrication techniques. This device was placed in a dedicated chip-holder, which includes a ceramic heater on the silicon side. The temperature was controlled and monitored by three K-type thermocouples: two were located between the heater and the silicon substrate, one to set the temperature and one to measure it, and the third one was placed in a 300 μm wide and 450 μm deep groove on the glass side to determine the heat loss over the silicon. An adjustable back pressure regulator and a pressure meter were added to control and evaluate the pressure during the experiment. Aqueous biomass solutions (10 wt%) were pumped at a flow rate of 10 μL/min using a syringe pump, and the temperature was slowly increased until the theoretical saturation temperature for the pre-set pressure was reached. First and surprisingly, a significant difference was observed between our theoretical saturation temperature and the experimental results. The experimental values were 10’s of degrees higher than the calculated ones and, in some cases, saturation could not be achieved. This discrepancy can be explained in different ways. Firstly, the pressure in the microchannel is locally higher due to both the thermal expansion of the liquid and the Laplace pressure that has to be overcome before a gas bubble can be formed. Secondly, superheating effects are likely to be present. Next, once saturation was reached, the flow pattern of the gas/liquid multiphase system was recorded. In our device, the point of nucleation can be controlled by taking advantage of the pressure drop across the channel and the accurate control of the temperature. Specifically, a higher temperature resulted in nucleation further upstream in the channel. As the void fraction increases downstream, the flow regime changes along the channel from bubbly flow to Taylor flow and later to annular flow. All three flow regimes were observed simultaneously. The findings of this study are key for the development and optimization of a microreactor for hydrogen production from biomass.

Keywords: biomass conversion, high pressure and high temperature microfluidics, multiphase, phase diagrams, superheating

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Authors: Praveen Chandramenon, Andrew Gascoyne, Fideline Tchuenbou-Magaia

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Aquaponics offers a simple conclusive solution to the food and environmental crisis of the world. This approach combines the idea of Aquaculture (growing fish) to Hydroponics (growing vegetables and plants in a soilless method). Smart Aquaponics explores the use of smart technology including artificial intelligence and IoT, to assist farmers with better decision making and online monitoring and control of the system. Identification of different growth stages of Swiss Chard plants and predicting its harvest time is found to be important in Aquaponic yield management. This paper brings out the comparative analysis of a standard Aquaponics with a Vermiponics (Aquaponics with worms), which was grown in the controlled environment, by implementing IoT and deep learning-based growth stage segregation and harvest time prediction of Swiss Chards before and after applying an optimal freshwater replenishment. Data collection, Growth stage classification and Harvest Time prediction has been performed with and without water replenishment. The paper discusses the experimental design, IoT and sensor communication with architecture, data collection process, image segmentation, various regression and classification models and error estimation used in the project. The paper concludes with the results comparison, including best models that performs growth stage segregation and harvest time prediction of the Aquaponic and Vermiponic testbed with and without freshwater replenishment.

Keywords: aquaponics, deep learning, internet of things, vermiponics

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Authors: Wojciech J. Nowak, Natalia Maciaszek, Marcin Drajewicz

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A constant requirement to reduce greenhouse gas emissions in combination with the desire to increase gas turbine efficiency results in a continuous trend to increase the operating temperature of gas turbines. An increase in operating temperature will result in lower fuel consumption, and a higher combustion temperature will result in lower pollution release. Moreover, there is a strong trend for hydrogen to be used as an alternative and clean fuel. However, using hydrogen or hydrogen-rich fuel results in a higher combustion temperature, as well as an increase in the water vapor content in the exhaust gases. Commonly used Ni-base alloys have their limits. Moreover, the presence of water vapor worsens the oxidation behavior of Ni-based alloys at a high temperature. Therefore, a new brand of materials is demanded to be used in gas turbines operated with hydrogen-rich fuel. High-entropy alloys (HEAs) seem to be very promising materials to replace commonly used Ni-based alloys. HEAs are the group of materials consisting of at least five main equiatomic elements. These alloys can be doped by other elements in amounts less than 5 at. % in total. Thus, in the present study, NiCoCrAlFe-X alloys are studied in terms of oxidation behavior during exposure to dry and wet atmospheres up to 1000 h. NiCoCrAlFe-X alloys are doped with minor alloying elements in amounts ranging from 1-5 at.%. The effect of the chemical composition on oxidation resistance in dry and wet atmospheres will be shown and discussed.

Keywords: high entropy alloys, oxidation resistance, hydrogen fuel, water vapor

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Authors: Ogbe E. E., Ossia. C. V., Saturday. E. G., Ezekwe M. C.

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The disparity in power output between a simple and a modified gas turbine plant is noticeable when the gas turbine functions under local environmental conditions that deviate from the standard ISO specifications. Extensive research and literature have demonstrated a well-known direct correlation between ambient temperature and the power output of a gas turbine plant. In this study, the Omotosho gas turbine plant was modified into three different configurations. The reason for the modification is to improve its performance and reduce the fuel consumption and emission rate. Aspen Hysys software was used to simulate both the simple (Omotosho) and the three modified gas turbine plants. The input parameters considered include ambient temperature, air mass flow rate, fuel mass flow rate, water mass flow rate, turbine inlet temperature, compressor efficiency, and turbine efficiency, while the output parameters considered are thermal efficiency, specific fuel consumption, heat rate, emission rate, compressor power, turbine power and power output. The three modified gas turbine power plants incorporate an inlet air cooling system and a heat recovery steam generator. The variations between the modifications are due to additional components or enhancements alongside the inlet air cooling system and heat recovery steam generator incorporated; the first modification has an additional turbine, the second modification has an additional combustion chamber, and the third modification has an additional turbine and combustion chamber. This paper clearly shows ambient temperature effects on both the simple and three modified gas turbine plants. for every 10-degree kelvin increase in ambient temperature, there is an approximate reduction of 3977 kW, 4795 kW, 4681 kW, and 4793 kW of the power output for the simple gas turbine, first, second, and third modifications, respectively. Also, for every 10-degree kelvin increase in temperature, there is a thermal efficiency decrease of 1.22%, 1.45%, 1.43%, and 1.44% for the simple gas turbine, first, second, and third modifications respectively. Low ambient temperature will help save fuel; looking at the high price of fuel presently in Nigeria for every 10 degrees kelvin increase in temperature, there is a specific fuel consumption increase of 0.0074 kg/kWh, 0.0051 kg/kWh, 0.0061 kg/kWh, and 0.0057 kg/kWh for the simple gas turbine, first, second, and third modifications respectively. These findings will aid in accurately evaluating local power generating plants, particularly in hotter regions, for installing gas turbine inlet air cooling (GTIAC) systems.

Keywords: Aspen HYSYS software, Brayton Cycle, modified gas turbine, power plant, simple gas turbine, thermal efficiency.

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Authors: Vano Benidze, Ioseb Berikashvili

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Since 2003, Georgia has implemented many successful reforms, however, economic growth, poverty alleviation and unemployment reduction are still major challenges facing country’s economy. This is due to the fact that most reforms during the past 2 decades were mainly geared toward improving the institutional environment, while economy’s sectoral composition and industrial policy were largely ignored. Each individual sector plays its own specific role in the functioning of the whole economy that cannot be accomplished by any other sector. However, given the unavoidable reality that one sector uses intermediate inputs from other industries to produce its output and sells part of its output to other sectors, the importance of sectors should consider these sectoral interdependencies as well. Simply put, not all industries are equally useful for economic growth and development. In this context, the aim of this paper is to identify the key economic sectors of the Georgian economy. Leontief input-output analysis has been used in deriving backward and forwards linkages for all sectors in the Georgian economy for 2020 and 2021. Sectors with both high backward and forward linkages have been identified as key sectors of the economy. The results obtained are beneficial for the success of the economic and industrial policy of Georgia. If targeted properly by thoughtful policy intervention, key sectors identified in this paper will have a high potential of spreading growth impulses throughout the economy and will possibly generate higher economic growth.

Keywords: structural change, key sectors, development strategies, input-output analysis

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Authors: Nandy Putra, Imansyah Ibnu Hakim, Iwan Setyawan, Muhammad Zayd A.I

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A two-phase cooling technology of passive system sometimes can no longer meet the cooling needs of an increasingly challenging due to the inherent limitations of the capillary pumping for example in terms of the heat flux that can lead to dry out. In this study, intended to overcome the dry out with the addition of a diaphragm, they pump to accelerate the fluid transportation from the condenser to the evaporator. Diaphragm pump installed on the bypass line. When it did not happen dry out then the hybrid loop heat pipe will be work passively using a capillary pressure of wick. Meanwhile, when necessary, hybrid loop heat pipe will be work actively, using diaphragm pump with temperature control installed on the evaporator. From the results, it can be said that the pump has been successfully overcome dry out and can distribute working fluid from the condenser to the evaporator and reduce the temperature of the evaporator from 143°C to 100°C as a temperature controlled where the pump start actively at set point 100°C.

Keywords: hybrid, heat pipe, dry out, assisted, pump

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Authors: Mohamed M. Emara, Heba Ashraf

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This study is to investigation the effect of silicon carbide (SiC) particle size and thermo-mechanical processing on dimensional stability of aluminum alloy 2124. Three combinations of SiC weight fractions are investigated, 2.5, 5, and 10 wt. % with different SiC particle sizes (25 μm, 5 μm, and 100nm) were produced using mechanical ball mill. The standard testing samples were fabricated using powder metallurgy technique. Both samples, prior and after extrusion, were heated from room temperature up to 400ºC in a dilatometer at different heating rates, that is, 10, 20, and 40ºC/min. The analysis showed that for all materials, there was an increase in length change as temperature increased and the temperature sensitivity of aluminum alloy decreased in the presence of both micro and nano-sized silicon carbide. For all conditions, nanocomposites showed better dimensional stability compared to conventional Al 2124/SiC composites. The after extrusion samples showed better thermal stability and less temperature sensitivity for the aluminum alloy for both micro and nano-sized silicon carbide.

Keywords: aluminum 2124 metal matrix composite, SiC nano-sized reinforcements, powder metallurgy, extrusion mechanical ball mill, dimensional stability

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Authors: Stephen Dankwa, Zheng Wenfeng, Xiaolu Li

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Climate change is recently gaining the attention of many countries across the world. Climate change, which is also known as global warming, referring to the increasing in average surface temperature has been a concern to the Environmental Protection Agency of Ghana. Recently, Ghana has become vulnerable to the effect of the climate change as a result of the dependence of the majority of the population on agriculture. The clearing down of trees to grow crops and burning of charcoal in the country has been a contributing factor to the rise in temperature nowadays in the country as a result of releasing of carbon dioxide and greenhouse gases into the air. Recently, petroleum stations across the cities have been on fire due to this climate changes and which have position Ghana in a way not able to withstand this climate event. As a result, the significant of this research paper is to project how the rise in the average surface temperature will be like at the end of the mid-21st century when agriculture and deforestation are allowed to continue for some time in the country. This study uses the Coupled Modeled Intercomparison Project phase 5 (CMIP5) experiment RCP 8.5 model output data to monitor the future climate changes from 2041-2050, at the end of the mid-21st century over the ten (10) major cities (Accra, Bolgatanga, Cape Coast, Koforidua, Kumasi, Sekondi-Takoradi, Sunyani, Ho, Tamale, Wa) in Ghana. In the models, Support Vector Machine and Random forest, where the cities as a function of heat wave metrics (minimum temperature, maximum temperature, mean temperature, heat wave duration and number of heat waves) assisted to provide more than 50% accuracy to predict and monitor the pattern of the surface air temperature. The findings identified were that the near-surface air temperature will rise between 1°C-2°C (degrees Celsius) over the coastal cities (Accra, Cape Coast, Sekondi-Takoradi). The temperature over Kumasi, Ho and Sunyani by the end of 2050 will rise by 1°C. In Koforidua, it will rise between 1°C-2°C. The temperature will rise in Bolgatanga, Tamale and Wa by 0.5°C by 2050. This indicates how the coastal and the southern part of the country are becoming hotter compared with the north, even though the northern part is the hottest. During heat waves from 2041-2050, Bolgatanga, Tamale, and Wa will experience the highest mean daily air temperature between 34°C-36°C. Kumasi, Koforidua, and Sunyani will experience about 34°C. The coastal cities (Accra, Cape Coast, Sekondi-Takoradi) will experience below 32°C. Even though, the coastal cities will experience the lowest mean temperature, they will have the highest number of heat waves about 62. Majority of the heat waves will last between 2 to 10 days with the maximum 30 days. The surface temperature will continue to rise by the end of the mid-21st century (2041-2050) over the major cities in Ghana and so needs to be addressed to the Environmental Protection Agency in Ghana in order to mitigate this problem.

Keywords: climate changes, CMIP5, Ghana, heat waves, random forest, SVM

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Authors: Keziah Bazar

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The effect of Brassica rapa leaf extracts on the growth of upland Ipomoea aquatica was investigated. One hundred grams Brassica rapa leaf were blended using a heavy duty blender. These were diluted with water to have final concentrations of 75% (T1), 50% (T2) and 25% (T3) that served as treatments of the study. Pure water (T0) that served as control was also included Upland Ipomoea aquatic were grown in pots. A 3-4 in water level was maintained during the whole duration of the study. Plant height, leaf area, fruit size and shoot height, were taken after 6 months. Results showed that plant height and shoot height was highest in T1 while T0 was the lowest. On the other hand, T2 had the highest leaf area and fruit size. The study suggests that T1 and T2 can be a good fertilizer for Ipomoea aquatica.

Keywords: Ipomoea aquatica, leaf extracts, growth, Brassica rapa

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Authors: Sankar Majumder

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Development of Rural Entrepreneurs requires a holistic approach involving social, economic, political, technical, and environmental and many other issues. It needs a thorough understanding of the economy and society. It's true that agricultural development, rural development and many other social and right based development programmes have resulted in the growth of income in the rural sector. The development of rural entrepreneurs is necessary to utilise these opportunities. Many programmes and policies in the spheres of organisational, financial, infrastructural and technical supports have been taken to promote rural industries. But if one looks at the growth and development of rural industrial units, especially the manufacturing units, the picture is not promising. This paper aims at analysing the possible causes and its solutions in terms of (1) Mind set of the society towards business as a livelihood; (2) Sufficiency and appropriateness of the existing organisational, financial, infrastructural and technical supports. The paper is based on secondary data on various aspects of rural enterprises and the author’s experiences in the course of his work as a practitioner in this field. Growth of units and employment in the rural industries shows that the entrepreneurs are more inclined towards trading units than towards manufacturing ventures. The growth of rural industries is constrained not by the insufficiency of the supply of finance but by the insufficient demand for finance. The task is to increase the supply of entrepreneurs by creating an entrepreneurial environment. Incubation for rural entrepreneurs is the need of the hour.

Keywords: business mind set, entrepreneurial environment, supply of finance, technical support

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Authors: Tafadzwa Shumba, Rose C. Nyatondo, Regret Sunge

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This research analyses the impact of budget deficits on the economic performance of Zimbabwe. The study employs the autoregressive distributed lag (ARDL) confines testing method to co-integration and long-run estimation using time series data from 1980-2018. The Augmented Dick Fuller (ADF) and the Granger approach were used to testing for stationarity and causality among the factors. Co-integration test results affirm a long term association between GDP development rate and descriptive factors. Causality test results show a unidirectional connection between budget shortfall to GDP development and bi-directional causality amid debt and budget deficit. This study also found unidirectional causality from debt to GDP growth rate. ARDL estimates indicate a significantly positive long term and significantly negative short term impact of budget shortfall on GDP. This suggests that budget deficits have a short-run growth retarding effect and a long-run growth-inducing effect. The long-run results follow the Keynesian theory that posits that fiscal deficits result in an increase in GDP growth. Short-run outcomes follow the neoclassical theory. In light of these findings, the government is recommended to minimize financing of recurrent expenditure using a budget deficit. To achieve sustainable growth and development, the government needs to spend an absorbable budget deficit focusing on capital projects such as the development of human capital and infrastructure.

Keywords: ARDL, budget deficit, economic performance, long run

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Authors: Atasi Dan, Kamanio Chattopadhyay, Bikramjit Basu

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A cost-effective titanium diboride (TiB2) paint coating has been developed on stainless steel substrate using commercially available polyvinylpyrrolidone as a binder by convenient dip-coating technique. The emittance of the coating has been explored by tailoring various process parameters to obtain highest thermal radiation. The optimized coating has achieved a high thermal emittance of 0.85. In addition, the coating exhibited an excellent thermal stability while heat-treated at 500 °C in air. Along with the emittance, the structural and physical properties of the As-deposited and heat-treated coatings have been investigated systematically. The high temperature annealing has not affected the emittance, chemical composition and morphology of the coating significantly. Hence, the fabricated paint coating is expected to open up new possibilities for using it as a low-cost, thermally stable emitter in high temperature applications.

Keywords: titanium diboride, emittance, paint coating, thermal stability

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Authors: Mauricio Cruz, Andrés Díaz García, Martha Isabel Gómez, Juan Carlos Serrato Bermúdez

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The disadvantages of using natural substrates in SSF processes have been well recognized and mainly are associated to gradual decomposition of the substrate, formation of agglomerates and decrease of porosity bed generating limitations in the mass and heat transfer. Additionally, in several cases, materials with a high agricultural value such as sour milk, beets, rice, beans and corn have been used. Thus, the use of economic inert supports (natural or synthetic) in combination with a nutrient suspension for the production of biocontrol microorganisms is a good alternative in SSF processes, but requires further studies in the fields of modeling and optimization. Therefore, the aim of this work is to compare the performance of two inert supports, a synthetic (polyurethane foam) and a natural one (rice husk), identifying the factors that have the major effects on the productivity of T. asperellum Th204 and the maximum specific growth rate in a PROPHYTA L05® fixed bed bioreactor. For this, the six factors C:N ratio, temperature, inoculation rate, bed height, air moisture content and airflow were evaluated using a fractional design. The factors C:N and air flow were identified as significant on the productivity (expressed as conidia/dry substrate•h). The polyurethane foam showed higher maximum specific growth rate (0.1631 h-1) and productivities of 3.89 x107 conidia/dry substrate•h compared to rice husk (2.83x106) and natural substrate based on rice (8.87x106) used as control. Finally, a quadratic model was generated and validated, obtaining productivities higher than 3.0x107 conidia/dry substrate•h with air flow at 0.9 m3/h and C:N ratio at 18.1.

Keywords: bioprocess, scale up, fractional design, C:N ratio, air flow

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Authors: Rania Samir Zaki

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Because of their inhibitory effects, selected probiotic Lactobacilli may be used as antimicrobial against some hazardous microorganisms responsible for spoilage of fresh minced beef (cattle) minced meat and camel minced meat. Lactic acid bacteria were isolated from camel meat. These included 10 isolates; 1 Lactobacillus fermenti, 4 Lactobacillus plantarum, 4 Lactobacillus pulgaricus, 3 Lactobacillus acidophilus and 1 Lactobacillus brevis. The most efficient inhibitory organism was Lactobacillus plantarum which can be used as a propiotic with antibacterial activity. All microbiological analyses were made at the time 0, first day and the second day at altered ranges of temperature [4±2 ⁰C (chilling temperature), 25±2 ⁰C, and 38±2 ⁰C]. Results showed a significant decrease of pH 6.2 to 5.1 within variant types of meat, in addition to reduction of Total Bacterial Count, Enterococci, Bacillus cereus and Escherichia coli together with the stability of Coliforms and absence of Staphylococcus aureus.

Keywords: antibacterial, camel meat, inhibition, probiotics

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Authors: Neelam Kadyan

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Global environmental change is happening at an alarming rate in the present world. Floods, Tsunamis’, Avalanches, Change in Weather patterns, Rise in sea temperature, Landslides, are only few evidences of this change. To regulate such alarming growth of global change in environment certain regulatory system or mechanism is required. Nuisance,negligence,absolute liability,strict liability and trespass are some of the effective common law principles which are helpful in environmental problems. What we need today is sufficient law and adequate machinery to enforce the legal standards. Without law environmental standards cannot be enforced and once again there is need to adopt the common law approach in solving the problem of environmental change as through this approach the affected person can get compensation and as the same time it puts check on wrongdoer.

Keywords: global environmental problems, nuisance, negligence, trespass, strict liability, absolute liability

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Authors: Fakhreia A. Al Sagheer, Enas I. Ibrahim, Khaled D. Khalil

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N-Acryloyl morpholine, NAM, was grafted onto chitosan utilizing homogeneous conditions with 1% acetic acid as the solvent, and potassium persulfate and sodium sulfite as the redox initiator. The effects of various reaction parameters, such as time, temperature, and monomer and initiator concentrations, on the percentage of grafting (G%) and the grafting efficiency (E%) were determined. The graft copolymer showed a remarkably improved crystallinity, as compared to the unmodified chitosan, based on the FESEM, XRD, and DSC results. Chitosan-g-poly(N-acryloyl morpholine) (Cs-PNAM), the copolymer obtained by using this procedure, was characterized by utilizing FTIR, FESEM, TGA, and XRD analysis. As expected, the results of an evaluation of antibacterial and antifungal activities show that the grafted chitosan copolymers exhibit stronger inhibitory effects against both types of microbes than does chitosan. Moreover, the size of the inhibition zone created by the graft copolymer was observed to be proportional to its G% corresponding to its morpholine content. Fortunately, the graft copolymer showed a marked growth inhibition against candidiasis (C.Albicans and C.Kefyr). We conclude that the graft copolymer may be highly effective in the prevention and treatment of candidiasis. In addition, the extent and pH dependence of uptake of different types of dyes (acidic: EBT, and MV; and basic: MB) by grafted chitosan in pH 6.5 aqueous solutions was determined. The results show that, the grafted copolymer exhibited a greater affinity to absorb the acid dyes more than the basic ones especially at relatively low temperature. Thus the modified chitosan can be used, in wastewater treatment, as efficient economic absorbent especially for anionic dyes from the industrial processing effluents.

Keywords: chitosan, N-Acryloyl morpholine, homogeneous grafting, antimicrobial activity, dye uptake

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Authors: Imoukhuede Oladunni Bimpe, Ale Monday Olatunbosun

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Periodic scarcity of onion requires urgent solution in Nigerian agro-economy. The high percentage of onion losses incurred after harvesting period is due to non-availability of appropriate facility for its storage. Therefore, some storage structures were constructed with different roofing materials. The response of the materials to the weather parameters like temperature and relative humidity were evaluated to know their effects on the performance of the storage structures. The temperature and relative humidity were taken three times daily alongside with the weight of the onion in each of the structures; the losses as indicated by loss indices like shrinkage, rottenness, sprouting and colour were identified and percentage loss per week determined. The highest mean percentage loss (22%) was observed in the structure with iron roofing materials while structure with thatched materials had the lowest (9.4%); The highest temperature was observed in the structure with Asbestos roofing materials and no significant difference in the temperature value in the structure with thatched and Iron materials; highest relatively humidity was found in Asbestos roofing material while the lowest in the structure with Iron materials. It was conclusively found that the storage structure with thatched roof had the best performance in terms of losses.

Keywords: onion, storage structures, weather parameters, roof materials, losses

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Authors: Mohammadreza Sedighi, Mohammad Said Saidi, Hesamoddin Salarian

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A numerical study has been performed to investigate the effect of using different turbulent models on natural convection flow field and temperature distributions in partially heated square cavity compare to benchmark. The temperature of the right vertical wall is lower than that of heater while other walls are insulated. The commercial CFD codes are used to model. Standard k-w model provided good agreement with the experimental data.

Keywords: Buoyancy, Cavity, CFD, Heat Transfer, Natural Convection, Turbulence

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Authors: Marzieh Fotovvat, Farzaneh Najafi, Ramazan Ali Khavari-Nejad, Daryush Talei, Farhad Rejali

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Salvia leriifolia Benth. is one of the valuable and perennial medicinal plants of the Lamiaceae family, geographically growing in the south and tropical regions of Khorassan and Semnan provinces in Iran. In recent years, several medicinal properties such as antimicrobial, antifungal, anti-diabetic, analgesic, and anti-inflammatory effects have been reported from this plant. The use of elicitors such as chitosan and Arbuscular mycorrhizal fungi (AMF) symbiosis are the main methods for increasing the production of secondary metabolites, growth, and physiological factors in plants. The main aim of this study was to investigate the effects of foliar spraying applications by chitosan and/or the contribution of AMF (Glomus interaradices) on some growth factors and chlorophyll content of S. leriifolia under glasshouse conditions. The sterilized seeds were germinated by placing them into a cocopeat. After one month, seedlings that were in the 2-4 leaf stage were transferred to plastic pots (garden soil and pumice at 2:1) with or without mycorrhizal fungi. Chitosan (0, 50, 100, 200, and 400 mg L-1) was sprayed four times in the fourth month of the vegetative period. The results showed that fresh leaf weight, fresh root weight, root height, and chlorophyll content could change in the plant treated with chitosan and AMF symbiosis. So that the highest chlorophyll content and fresh weight of roots and leaves were observed in the interaction of chitosan and G. interaradices. In general, by optimizing the chitosan concentration and the use of appropriate AMF symbiosis, it is possible to improve the growth and quality of the medicinal plant S. leriifolia.

Keywords: chitosan, chlorophyll, growth factors, mycorrhiza

Procedia PDF Downloads 68

Authors: M. A. Hamza, H. A. Bosila, M. A. Zewil, I. M. Harridy

Abstract:

Silymarin is one active component extracted from milk thistle Silybum marianum; it is flavonoid recognized for its ability to benefit people with liver disorders and as a protective compound against liver damaging agents. For this reason, this research aims to study the effect of growth regulators (BA+NAA) and explant type (cotyledon, hypocotyl, and root) to increase the growth and active ingredients (silymarin) in callus of S. mariaum plant. The results showed that cotyledon explant which have been cultured in MS medium supplemented with BA 0.4 mg/l. +NAA 0.25 mg/l. Led to obtain the best results in callus fresh weight (1.847a) and callus dry weight (0.155a). On the other hand, the same explant (cotyledon) cultured in MS medium supplemented with BA 1.6 mg/l. + NAA 0.5 mg/l. The suitable condition to silymarin content (0.132 mg/100 mg dry weight). And also, it turned out, lack of importance of the use of hypocotyl and root in the production of callus and silymarin compared to cotyledon.

Keywords: silybum, callus, tissue culture, cotyledon

Procedia PDF Downloads 186

Authors: Do Su Park, Sang Jun Park, Cheon Soon Jeong

Abstract:

This study was performed in order to investigate the optimum ripening conditions for the marketing of Squash. Research sample 'Bochang' was grown at Hongcheonin in Gangwon province in August 2014. Ripening the samples were stored under the conditions of 25℃, 30℃, and 35℃ with the humidity RH70 ± 5%. They were checked every 3 days for 21 days. The respiration rate, water loss, hardness, coloration, the contents of soluble solids, starch, total sugar were evaluated after storage. Respiration rate was reduced in all treatments with longer storage period. Water loss was increased in the higher temperature. The 13% water loss was found at 35℃ on 21st storage day. The store initially 25℃ and 30℃ Hardness 47N and the ripening 21 days decreased slightly. On the other hand, in the case of 35℃ showed a large reduction than 25℃ and 30℃. Soluble solid contents were increased with longer ripening period. 30℃ and 35℃ was highest ripening 15 days. In the case of 25℃, it was highest on 21th day. The higher the temperature, the higher the soluble solids content are. 25℃ and 30℃ Coloration was increased rapidly until the ripening 12 days. In case of 35℃, continued increase up to 21 days. 25℃ and 30℃ showed no differences. Meanwhile, in case of 35℃, appearance quality was reduced in Occurrence of yellowing phenomenon of pericarp occurs from after ripening for 9 days. The coloration of fruit flesh is increase until after ripening for 9 days and decrease from after ripening for 9 days. There was no significant difference depending on the conditions of temperature. The higher the temperature, the lower the content of the starch. In case of 30℃ and 35℃, was reduced with longer storage period. 25℃ was minimal content change. Total sugar was increased in all treatments with longer storage period. The higher the temperature, the higher the amount of total sugar content is. Therefore, at 25℃ for 18-21 days and at 30℃ for 12-15 days is suitable for ripening.

Keywords: marketing, ripening, temperature, winter squash

Procedia PDF Downloads 590

Authors: Yongjian Gu

Abstract:

Ocean thermal energy is one of the ocean energy sources. It is a renewable, sustainable, and green energy source. Ocean thermal energy conversion (OTEC) applies the ocean temperature gradient between the warmer surface seawater and the cooler deep seawater to run a heat engine and produce a useful power output. Unfortunately, the ocean temperature gradient is not big. Even in the tropical and equatorial regions, the surface water temperature can only reach up to 28oC and the deep water temperature can be as low as 4oC. The thermal efficiency of the OTEC plants, therefore, is low. In order to improve the plant thermal efficiency by using the limited ocean temperature gradient, some OTEC plants use the method of adding more equipment for better heat recovery, such as heat exchangers, pumps, etc. Obviously, the method will increase the plant's complexity and cost. The more important impact of the method is the additional equipment needs to consume power too, which may have an adverse effect on the plant net power output, in turn, the plant thermal efficiency. In the paper, the author first describes varied OTEC plants and the practice of using the method of adding more equipment for improving the plant's thermal efficiency. Then the author proposes a parameter, plant back works ratio ϕ, for measuring if the added equipment is appropriate for the plant thermal efficiency improvement. Finally, in the paper, the author presents examples to illustrate the application of the back work ratio ϕ as a key parameter in the OTEC plant design and operation.

Keywords: ocean thermal energy, ocean thermal energy conversion (OTEC), OTEC plant, plant back work ratio ϕ

Procedia PDF Downloads 183

Authors: Noe Brice Nkoumbou Kaptchouang, Pierre-Guy Vincent, Yann Monerie

Abstract:

The present work addresses the modelling and the simulation of crack initiation and propagation in ductile materials which failed by void nucleation, growth, and coalescence. One of the current research frameworks on crack propagation is the use of cohesive-volumetric approach where the crack growth is modelled as a decohesion of two surfaces in a continuum material. In this framework, the material behavior is characterized by two constitutive relations, the volumetric constitutive law relating stress and strain, and a traction-separation law across a two-dimensional surface embedded in the three-dimensional continuum. Several cohesive models have been proposed for the simulation of crack growth in brittle materials. On the other hand, the application of cohesive models in modelling crack growth in ductile material is still a relatively open field. One idea developed in the literature is to identify the traction separation for ductile material based on the behavior of a continuously-deforming unit cell failing by void growth and coalescence. Following this method, the present study proposed a semi-analytical cohesive model for ductile material based on a micromechanical approach. The strain localization band prior to ductile failure is modelled as a cohesive band, and the Gurson-Tvergaard-Needleman plasticity model (GTN) is used to model the behavior of the cohesive band and derived a corresponding traction separation law. The numerical implementation of the model is realized using the non-smooth contact method (NSCD) where cohesive models are introduced as mixed boundary conditions between each volumetric finite element. The present approach is applied to the simulation of crack growth in nuclear ferritic steel. The model provides an alternative way to simulate crack propagation using the numerical efficiency of cohesive model with a traction separation law directly derived from porous continuous model.

Keywords: ductile failure, cohesive model, GTN model, numerical simulation

Procedia PDF Downloads 136

Authors: Eda Cagli, Irem Erel Goktepe

Abstract:

Externally triggered and effective release of therapeutics from polymer nanoplatforms is one of the key issues in cancer treatment. In this study, we aim to prepare polymer multilayer films which are stable at physiological conditions (little or no drug release) but release drug molecules at acidic pH and via application of AC magnetic field. First, novel stimuli responsive diblock copolymers composed of pH- and temperature-responsive blocks were synthesized. Then, block copolymer micelles with pH-responsive core and temperature responsive coronae will be obtained via pH-induced self-assembly of these block copolymers in aqueous environment. A model anticancer drug, e.g. Doxorubicin will be loaded in the micellar cores. Second, superparamagnetic nanoparticles will be synthesized. Magnetic nanoparticles and drug loaded block copolymer micelles will be used as building blocks to construct the multilayers. To mimic the acidic nature of the tumor tissues, Doxorubicin release from the micellar cores will be induced at acidic conditions. Moreover, Doxorubicin release from the multilayers will be facilitated via magnetothermal trigger. Application of AC magnetic field will induce the heating of magnetic nanoparticles resulting in an increase in the temperature of the polymer platform. This increase in temperature is expected to trigger conformational changes on the temperature-responsive micelle coronae and facilitate the release of Doxorubicin from the surface. Such polymer platform may find use in biomedical applications.

Keywords: layer-by-layer films, magnetothermal trigger, smart polymers, stimuli responsive

Procedia PDF Downloads 356

Authors: Aziez Ouahiba, Remini Boualam, Habi Mohamed

Abstract:

the growth and the development of a pay are strongly related to the existence or the absence of water in this area, The sedentary lifestyle of the population makes that water demand is increasing and the different brandishing (dams, tablecloths or other) are increasingly solicited. In normal time rain and snow of the winter period reloads the slicks and the wadis that fill dams. Over these two decades, global warming fact that temperature is increasingly high and rainfall is increasingly low which induces a charge less and less important tablecloths, add to that the strong demand in irrigation. Our study will focus on the variation of rainfall and irrigation, their effects on the degree of pollution of the groundwater in this area based on statistical analyses by the Xlstat (ACP, correlation...) software for a better explanation of these results and determine the hydrochemistry of different groups or polluted areas pou be able to offer adequate solutions for each area.

Keywords: rainfall, groundwater of mitidja, irrigation, pollution

Procedia PDF Downloads 393

Authors: Mohamed Abdelfattah Meawad Hamza, H. A. Bosila, M. A. Zewil

Abstract:

This research aims to study the effect of different sources of elicitors for increase growth and active ingredients in callus of Echinacea purpurea plant. Callus that have been obtained from leaf explant, was used to conduct the following studies. A study of the impact of both the phenylalanine and tyrosine (50, 100,150 and 200 mg/l.) individually and casein hydrolysate (100, 200 and 300 mg/l.) supplemented to MS medium. Results show that Casein hydrolysate 100 mg/l. has achieved the better results in both callus fresh weight 1.881 g/explant after 8 weeks of the incubation period and callus growth rate 0.398 g/explant after 6 weeks of the incubation period, while gave add 200 mg/l. The best results in total carbohydrate 2.444 mg/ 100 mg dry weight. Phenylalanine 150 mg/l. has achieved the best results in callus dry weight 0.156 g/explant after 8 weeks of incubation period. Tyrosine 200 mg/l. recorded the best result for positive production of caffeic acid 0.460 mg/ 100 mg dry weight after 4 weeks incubation period.

Keywords: tissue culture, echinacea, tyrosine, casein

Procedia PDF Downloads 259

Authors: Zayneb Kthiri, Walid Hamada

Abstract:

The application of organic fertilizers is generally known to be useful to sustain soil fertility and plant growth, especially in poor soils, with less than 1% of organic matter, as it is very common in our Tunisian fields. Therefore, we focused on evaluating the effect of a new released liquid organic fertilizer named Solorga (with 5% of organic matter) compared to a reference product (Espartan: Kimitec, Spain) on tomato plant growth and physiology. Both fertilizers, derived from plant decomposition, were applied at an early stage in hydroponic system and under greenhouse. In hydroponic system, after 14 days of their application by root feeding, a significant difference was observed between treatments. Indeed, Solorga improved shoots and roots length, as well as the biomass respectively, by 45%, 27%, and 27.8% increase rate, while compared to control plants. However, Espartan induced less the measured parameters while compared to untreated control. Moreover, Solorga significantly increased the chlorophyll content by 42% compared to control and by 32% compared to Espartan. In the greenhouse, after 20 days of treatments, the results showed a significant effect of both fertilizers on SPAD index and the number of flowers blossom. Solorga increased the amount of chlorophyll present in the leaf by 7% compared to Espartan as well as the plant height under greenhouse. Moreover, the number of flowers blossom increased by 15% in plants treated with Solorga while compared to Espartan. Whereas, there is no notable difference between both organic fertilizers on the fruits blossom and the number of fruits per blossom. In conclusion, even though there is a difference in the organic matter between both fertilizers, Solorga improved better the plant growth in controlled conditions in hydroponic system while compared to Espartan. Altogether the obtained results are encouraging for the use of Solorga as a soil enriching source of organic matter to help plants to boost their growth and help them to overcome abiotic stresses linked to soil fertility.

Keywords: tomato, plant growth, organic fertilizer, hydroponic system, greenhouse

Procedia PDF Downloads 123