Search results for: subcritical water
1223 Sustainability and Promotion of Inland Waterway Transportation Projects in Colombia: Case of the Magdalena River
Authors: David Julian Bernal Melgarejo
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Inland Waterway Transportation (IWT) is playing an important role in national transport systems, water transportation is considered to be safe, energy efficient and environmentally friendly mode of transport, all benefits of IWT cause national awareness increase, for instance the Colombian government is planning to restore the navigability of the most important river of the country, the Magdalena’s River navigability, embrace waterway transportation in Colombia could strength competitiveness while reduce most of the transport externalities. However, the current situation of the Magdalena is deplorable, the most important river of Colombia has been abandoned for decades and the solution is beyond of a single administrative entity. This paper analyzes the outcomes of the Navigation And Inland Waterway Action and Development in Europe program (NAIADES) as a prospective to develop a similar program in Colombia with similar objectives and guidelines, considering sustainability, guarantying the long-term future results and adaptability of the program. Identifying stakeholders and policy experts, a set of individual interviews were carried out; findings support the idea of lack of integration within governmental institutions and lack of importance in marketing promotion as possible drawbacks on the implementation of IWT projects.
Keywords: Inland waterway transportation, Logistics, Sustainability, Multimodal transport systems, Water transportation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28131222 Snails and Fish as Pollution Biomarkers in Lake Manzala and Laboratory B: Lake Manzala Fish
Authors: Hanaa M. M. El-Khayat, Hanan S. Gaber, Hoda Abdel-Hamid, Kadria M. A. Mahmoud, Hoda M. A. Abu Taleb
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This work aimed to examine Oreochromis niloticus fish from Lake Manzala in Port Said, Dakahlya and Damietta governorates, Egypt, as a bio-indicator for the lake water pollution through recording alterations in their hematological, physiological, and histopathological parameters. All fish samples showed a significant increase in levels of alkaline phosphatase (ALP), creatinine and glutathione-S-transferase (GST); only Dakahlya samples showed a significant increase (p<0.01) in aspartate aminotransferase (AST) level and most Dakahlya and Damietta samples showed reversed albumin and globulin ratio and a significant increase in γ-glutamyltransferase (GGT) level. Port-Said and Damietta samples showed a significant decrease of hemoglobin (Hb) while Dakahlya samples showed a significant decrease in white blood cell (WBC) count. Histopathological investigation for different fish organs showed that Port-Said and Dakahlya samples were more altered than Damietta. The muscle and gill followed by intestine were the most affected organs. The muscle sections showed severe edema, neoplasia, necrotic change, fat vacuoles and splitting of muscle fiber. The gill sections showed dilated blood vessels of the filaments, curling of gill lamellae, severe hyperplasia, edema and blood vessels congestion of filaments. The intestine sections revealed degeneration, atrophy, dilation in blood vessels and necrotic changes in sub-mucosa and mucosa with edema in between. The recorded significant alterations, in most of the physiological and histological parameters in O. niloticus samples from Lake Manzala, were alarming for water pollution impacts on lake fish community, which constitutes the main diet and the main source of income for the people inhabiting these areas, and were threatening their public health and economy. Also, results evaluate the use of O. niloticus fish as important bio-indicator for their habitat stressors.
Keywords: Lake Manzala, Oreochromis niloticus fish, water pollution, physiological, hematological and histopathological parameters.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15461221 GIS-based Non-point Sources of Pollution Simulation in Cameron Highlands, Malaysia
Authors: M. Eisakhani, A. Pauzi, O. Karim, A. Malakahmad, S.R. Mohamed Kutty, M. H. Isa
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Cameron Highlands is a mountainous area subjected to torrential tropical showers. It extracts 5.8 million liters of water per day for drinking supply from its rivers at several intake points. The water quality of rivers in Cameron Highlands, however, has deteriorated significantly due to land clearing for agriculture, excessive usage of pesticides and fertilizers as well as construction activities in rapidly developing urban areas. On the other hand, these pollution sources known as non-point pollution sources are diverse and hard to identify and therefore they are difficult to estimate. Hence, Geographical Information Systems (GIS) was used to provide an extensive approach to evaluate landuse and other mapping characteristics to explain the spatial distribution of non-point sources of contamination in Cameron Highlands. The method to assess pollution sources has been developed by using Cameron Highlands Master Plan (2006-2010) for integrating GIS, databases, as well as pollution loads in the area of study. The results show highest annual runoff is created by forest, 3.56 × 108 m3/yr followed by urban development, 1.46 × 108 m3/yr. Furthermore, urban development causes highest BOD load (1.31 × 106 kgBOD/yr) while agricultural activities and forest contribute the highest annual loads for phosphorus (6.91 × 104 kgP/yr) and nitrogen (2.50 × 105 kgN/yr), respectively. Therefore, best management practices (BMPs) are suggested to be applied to reduce pollution level in the area.Keywords: Cameron Highlands, Land use, Non-point Sources of Pollution
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28591220 Brazilian Constitution and the Fundamental Right to Sanitation
Authors: Michely Vargas Delpupo, José Geraldo Romanello Bueno
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The right to basic sanitation, was elevated to the category of fundamental right by the Constitution of 1988 to protect the ecologically balanced environment, ensuring social rights to health and adequate housing and put the dignity of the human person as the foundation of the Brazilian Democratic State. Before their essentiality to humans, this article seeks to understand why universal access to basic sanitation is a goal so difficult to achieve in Brazil. Therefore, this research uses the deductive and analytical method. Given the nature of the research literature, research techniques were centered in specialized books on the subject, journals, theses and dissertations, laws, relevant law case and raising social indicators relating to the theme. The relevance of the topic stems, among other things, the fact that sanitation services are essential for a dignified life, i.e., everyone is entitled to the maintenance of the necessary existence conditions are satisfied. However, the effectiveness of this right is undermined in society, since Brazil has huge deficit in sanitation services, denying thus a worthy life to most of the population. Thus, it can be seen that the provision of water and sewage services in Brazil is still characterized by a large imbalance, since the municipalities with lower population index have greater disability in the sanitation service. The truth is that the precariousness of water and sewage services in Brazil is still very concentrated in the North and Northeast regions, limiting the effective implementation of the Law 11.445/2007 in the country. Therefore, there is urgent need for a positive service by the State in the provision of sanitation services in order to prevent and control disease, improve quality of life and productivity of individuals, besides preventing contamination of water resources. More than just social and economic necessity, there is a government duty to implement such services. In this sense, given the current scenario, to achieve universal access to basic sanitation imposes many hurdles. These are mainly in the field of properly formulated and implemented public policies, i.e., it requires an excellent institutional organization, management services, strategic planning, social control, in order to provide answers to complex challenges.Keywords: Fundamental rights, sanitation, universal access.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16181219 Development and Characterization of Wheat Bread with Lupin Flour
Authors: Paula M. R. Correia, Marta Gonzaga, Luis M. Batista, Luísa Beirão-Costa, Raquel F. P. Guiné
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The purpose of the present work was to develop an innovative food product with good textural and sensorial characteristics. The product, a new type of bread, was prepared with wheat (90%) and lupin (10%) flours, without the addition of any conservatives. Several experiences were also done to find the most appropriate proportion of lupin flour. The optimized product was characterized considering the rheological, physical-chemical and sensorial properties. The water absorption of wheat flour with 10% of lupin was higher than that of the normal wheat flours, and Wheat Ceres flour presented the lower value, with lower dough development time and high stability time. The breads presented low moisture but a considerable water activity. The density of bread decreased with the introduction of lupin flour. The breads were quite white, and during storage the colour parameters decreased. The lupin flour clearly increased the number of alveolus, but the total area increased significantly just for the Wheat Cerealis bread. The addition of lupin flour increased the hardness and chewiness of breads, but the elasticity did not vary significantly. Lupin bread was sensorially similar to wheat bread produced with WCerealis flour, and the main differences are the crust rugosity, colour and alveolus characteristics.
Keywords: Lupin flour, physical-chemical properties, sensorial analysis, wheat flour.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25231218 Assessment of Physicochemical Characteristics and Heavy Metals Concentration in Freshwater from Jega River, Kebbi State, Nigeria
Authors: D. Y. Bawa, M. I. Ribah, I. S. Jega, V. O. Oyedepo
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This study was conducted to determine the physicochemical characteristics and heavy metal concentration (Cadmium (Cd), Copper (Cu), Iron (Fe), Lead (Pb) and Zinc (Zn)) in freshwater from Jega river. 30 water samples were collected in two 1-liter sterile plastic containers from three designated sampling points, namely; Station A (before the bridge; upstream), Station B (at the bridge where human activities such as washing of cars, motorbike, clothes, bathing and other household materials are concentrated), Station C (after the bridge; downstream) fortnightly, between March and July 2014. Results indicated that the highest pH mean value of 7.08 ± 1.12 was observed in station C, the highest conductivity with the mean 58.75 ± 7.87 µs/cm was observed at station A, the highest mean value of the water total hardness was observed at station A (54 ± 16.11 mg/L), the highest mean value of nitrate deposit was observed in station A (1.66 ± 1.33 mg/L), the highest mean value of alkalinity was observed at station B (51.33 ± 6.66 mg/L) and the highest mean (39.56 ± 3.24 mg/L) of total dissolved solids was observed at station A. The highest concentration mean value of Fe was observed in station C (65.33 ± 4.50 mg/L), the highest concentrations of Cd was observed in station C (0.99 ± 0.36 mg/L), the mean value of 2.13 ± 1.99 mg/L was the highest concentration of Zn observed in station B, the concentration of Pb was not detected (ND) and the highest concentration of Cu with the mean value of 0.43 ± 0.16 mg/L was observed in station B, while the lowest concentration was observed at station C (0.27 ± 0.26 mg/L). Statistical analysis shows no significant difference (P > 0.05) among the sampling stations for both the physicochemical characteristics and heavy metal concentrations. The results were found to be within the internationally acceptable standard limits.
Keywords: Assessment, freshwater, heavy metal concentration, physicochemical.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10081217 Effects of the In-Situ Upgrading Project in Afghanistan: A Case Study on the Formally and Informally Developed Areas in Kabul
Authors: Maisam Rafiee, Chikashi Deguchi, Akio Odake, Minoru Matsui, Takanori Sata
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Cities in Afghanistan have been rapidly urbanized; however, many parts of these cities have been developed with no detailed land use plan or infrastructure. In other words, they have been informally developed without any government leadership. The new government started the In-situ Upgrading Project in Kabul to upgrade roads, the water supply network system, and the surface water drainage system on the existing street layout in 2002, with the financial support of international agencies. This project is an appropriate emergency improvement for living life, but not an essential improvement of living conditions and infrastructure problems because the life expectancies of the improved facilities are as short as 10–15 years, and residents cannot obtain land tenure in the unplanned areas. The Land Readjustment System (LRS) conducted in Japan has good advantages that rearrange irregularly shaped land lots and develop the infrastructure effectively. This study investigates the effects of the In-situ Upgrading Project on private investment, land prices, and residents’ satisfaction with projects in Kart-e-Char, where properties are registered, and in Afshar-e-Silo Lot 1, where properties are unregistered. These projects are located 5 km and 7 km from the CBD area of Kabul, respectively. This study discusses whether LRS should be applied to the unplanned area based on the questionnaire and interview responses of experts experienced in the In-situ Upgrading Project who have knowledge of LRS. The analysis results reveal that, in Kart-e-Char, a lot of private investment has been made in the construction of medium-rise (five- to nine-story) buildings for commercial and residential purposes. Land values have also incrementally increased since the project, and residents are commonly satisfied with the road pavement, drainage systems, and water supplies, but dissatisfied with the poor delivery of electricity as well as the lack of public facilities (e.g., parks and sport facilities). In Afshar-e-Silo Lot 1, basic infrastructures like paved roads and surface water drainage systems have improved from the project. After the project, a few four- and five-story residential buildings were built with very low-level private investments, but significant increases in land prices were not evident. The residents are satisfied with the contribution ratio, drainage system, and small increase in land price, but there is still no drinking water supply system or tenure security; moreover, there are substandard paved roads and a lack of public facilities, such as parks, sport facilities, mosques, and schools. The results of the questionnaire and interviews with the four engineers highlight the problems that remain to be solved in the unplanned areas if LRS is applied—namely, land use differences, types and conditions of the infrastructure still to be installed by the project, and time spent for positive consensus building among the residents, given the project’s budget limitation.
Keywords: In-Situ Upgrading, Kabul, Land Readjustment, Land value, Planned areas, Private investment, Resident satisfaction, Unplanned areas.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 11341216 Prediction of Air-Water Two-Phase Frictional Pressure Drop Using Artificial Neural Network
Authors: H. B. Mehta, Vipul M. Patel, Jyotirmay Banerjee
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The present paper discusses the prediction of gas-liquid two-phase frictional pressure drop in a 2.12 mm horizontal circular minichannel using Artificial Neural Network (ANN). The experimental results are obtained with air as gas phase and water as liquid phase. The superficial gas velocity is kept in the range of 0.0236 m/s to 0.4722 m/s while the values of 0.0944 m/s, 0.1416 m/s and 0.1889 m/s are considered for superficial liquid velocity. The experimental results are predicted using different Artificial Neural Network (ANN) models. Networks used for prediction are radial basis, generalised regression, linear layer, cascade forward back propagation, feed forward back propagation, feed forward distributed time delay, layer recurrent, and Elman back propagation. Transfer functions used for networks are Linear (PURELIN), Logistic sigmoid (LOGSIG), tangent sigmoid (TANSIG) and Gaussian RBF. Combination of networks and transfer functions give different possible neural network models. These models are compared for Mean Absolute Relative Deviation (MARD) and Mean Relative Deviation (MRD) to identify the best predictive model of ANN.
Keywords: Minichannel, Two-Phase Flow, Frictional Pressure Drop, ANN, MARD, MRD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13951215 Investigation of Bubble Growth during Nucleate Boiling Using CFD
Authors: K. Jagannath, Akhilesh Kotian, S. S. Sharma, Achutha Kini U., P. R. Prabhu
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Boiling process is characterized by the rapid formation of vapour bubbles at the solid–liquid interface (nucleate boiling) with pre-existing vapour or gas pockets. Computational fluid dynamics (CFD) is an important tool to study bubble dynamics. In the present study, CFD simulation has been carried out to determine the bubble detachment diameter and its terminal velocity. Volume of fluid method is used to model the bubble and the surrounding by solving single set of momentum equations and tracking the volume fraction of each of the fluids throughout the domain. In the simulation, bubble is generated by allowing water-vapour to enter a cylinder filled with liquid water through an inlet at the bottom. After the bubble is fully formed, the bubble detaches from the surface and rises up during which the bubble accelerates due to the net balance between buoyancy force and viscous drag. Finally when these forces exactly balance each other, it attains a constant terminal velocity. The bubble detachment diameter and the terminal velocity of the bubble are captured by the monitor function provided in FLUENT. The detachment diameter and the terminal velocity obtained are compared with the established results based on the shape of the bubble. A good agreement is obtained between the results obtained from simulation and the equations in comparison with the established results.Keywords: Bubble growth, computational fluid dynamics, detachment diameter, terminal velocity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 21061214 Investigation on a Wave-Powered Electrical Generator Consisted of a Geared Motor-Generator Housed by a Double-Cone Rolling on Concentric Circular Rails
Authors: Barenten Suciu
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An electrical generator able to harness energy from the water waves and designed as a double-cone geared motor-generator (DCGMG), is proposed and theoretically investigated. Similar to a differential gear mechanism, used in the transmission system of the auto vehicle wheels, an angular speed differential is created between the cones rolling on two concentric circular rails. Water wave acting on the floating DCGMG produces and a gear-box amplifies the speed differential to gain sufficient torque for power generation. A model that allows computation of the speed differential, torque, and power of the DCGMG is suggested. Influence of various parameters, regarding the construction of the DCGMG, as well as the contact between the double-cone and rails, on the electro-mechanical output, is emphasized. Results obtained indicate that the generated electrical power can be increased by augmenting the mass of the double-cone, the span of the rails, the apex angle of the cones, the friction between cones and rails, the amplification factor of the gear-box, and the efficiency of the motor-generator. Such findings are useful to formulate a design methodology for the proposed wave-powered generator.
Keywords: Wave-powered electrical generator, double-cone, circular concentric rails, amplification of angular speed differential.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6951213 Fish Catch Composition from Gobind Sagar Reservoir during 2006-2012
Authors: Krishan Lal, Anish Dua
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Gobind Sagar Reservoir has been created in Himachal Pradesh, India (31° 25´ N and 76 ° 25´E) by damming River Sutlej at village Bhakra in 1963. The average water spread area of this reservoir is 10,000 hectares. Fishermen have organized themselves in the form of co-operative societies. 26 fisheries co-operative societies were working in Gobind Sagar Reservoir up till 2012. June and July months were observed as closed season, no fishing was done during this period. Proper record maintaining of fish catch was done at different levels by the state fisheries department. Different measures like minimum harvestable size, mesh size regulation and prohibition of illegal fishing etc. were taken for fish conservation. Fishermen were actively involved in the management. Gill nets were used for catching fishes from this reservoir. State fisheries department is realizing 15% royalty of the sold fish. Data used in this paper is about the fish catch during 2006-2012 and were obtained from the state fisheries department, Himachal Pradesh. Catla catla, Labeo rohita, Cirrhinus mrigala, Sperata seenghala, Cyprinus carpio, Tor putitora, Hypophthalmichthys molitrix, Labeo calbasu, Labeo dero and Ctenopharyngodon idella etc., were the fish species exploited for commercial purposes. Total number of individuals of all species caught was 3141236 weighing 5637108.9 kg during 2006-2012. H. molitrix was introduced accidently in this reservoir and was making a good share of fish catch in this reservoir. The annual catch of this species was varying between 161279.6 kg, caught in 2011 and 788030.8 kg caught in 2009. Total numbers of individuals of C. idella caught were 8966 weighing 64320.2 kg. The catch of Cyprinus carpio was varying between 144826.1 kg caught in 2006 and 214480.1 kg caught in 2010. Total catch of Tor putitora was 180263.2 kg during 2006-2012. Total catch of L. dero, S. seenghala and Catla catla remained 100637.4 kg, 75297.8 kg and 561802.9 kg, respectively, during 2006-2012. Maximum fish catch was observed during the months of August (after observing Closed Season). Maximum catch of exotic carps was from Bhakra area of the reservoir which has fewer fluctuations in water levels. The reservoir has been divided into eight beats for administrative purpose, to avoid conflicts between operating fisheries co-operative societies for area of operation. Fish catch was more by co-operative societies operating in the area of reservoir having fewer fluctuations in water level and catch was less by co-operative societies operating in the area of more fluctuations in water level. Species-wise fish catch by different co-operative societies from their allotted area was studied. This reservoir is one of most scientifically managed reservoirs.Keywords: Co-operative societies, fish catch, fish species, reservoir.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 15041212 Influence of Atmospheric Physical Effects on Static Behavior of Building Plate Components Made of Fiber-Cement-Based Materials
Authors: Jindrich J. Melcher, Marcela Karmazínová
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The paper presents the brief information on particular results of experimental study focused to the problems of behavior of structural plated components made of fiber-cement-based materials and used in building constructions, exposed to atmospheric physical effects given by the weather changes in the summer period. Weather changes represented namely by temperature and rain cause also the changes of the temperature and moisture of the investigated structural components. This can affect their static behavior that means stresses and deformations, which have been monitored as the main outputs of tests performed. Experimental verification is based on the simulation of the influence of temperature and rain using the defined procedure of warming and water sprinkling with respect to the corresponding weather conditions during summer period in the South Moravian region at the Czech Republic, for which the application of these structural components is mainly planned. Two types of components have been tested: (i) glass-fiber-concrete panels used for building façades and (ii) fiber-cement slabs used mainly for claddings, but also as a part of floor structures or lost shuttering, and so on.
Keywords: Atmospheric physical effect, building component, experiment, fiber-cement, glass-fiber-concrete, simulation, static behavior, test, warming, water sprinkling, weather.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 12321211 Comparison of Finite Difference Schemes for Water Flow in Unsaturated Soils
Authors: H. Taheri Shahraiyni, B. Ataie Ashtiani
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Flow movement in unsaturated soil can be expressed by a partial differential equation, named Richards equation. The objective of this study is the finding of an appropriate implicit numerical solution for head based Richards equation. Some of the well known finite difference schemes (fully implicit, Crank Nicolson and Runge-Kutta) have been utilized in this study. In addition, the effects of different approximations of moisture capacity function, convergence criteria and time stepping methods were evaluated. Two different infiltration problems were solved to investigate the performance of different schemes. These problems include of vertical water flow in a wet and very dry soils. The numerical solutions of two problems were compared using four evaluation criteria and the results of comparisons showed that fully implicit scheme is better than the other schemes. In addition, utilizing of standard chord slope method for approximation of moisture capacity function, automatic time stepping method and difference between two successive iterations as convergence criterion in the fully implicit scheme can lead to better and more reliable results for simulation of fluid movement in different unsaturated soils.Keywords: Finite Difference methods, Richards equation, fullyimplicit, Crank-Nicolson, Runge-Kutta.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 23591210 Effects of Cellular Insulin Receptor Stimulators with Alkaline Water on Performance, Plasma Cholesterol, Glucose, Triglyceride Levels and Hatchability in Breeding Japanese Quail
Authors: Rabia Göçmen, Gülşah Kanbur, Sinan Sefa Parlat
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Aim of this study is to determine the effects of cellular insulin receptor stimulators on performance, plasma glucose, high density lipoprotein (HDL), low density lipoprotein (LDL), total cholesterol, triglyceride, triiodothyronine (T3) and thyroxine (T4) hormone levels, and incubation features in the breeding Japanese quails (Coturnix japonica). In the study, a total of 84 breeding quails was used, 6 weeks’ age, 24 are male and 60, female. Rations used in experiment are 2900 kcal/kg metabolic energy and 20% crude protein. Water pH is calibrated to 7.45. Ration and water were administered ad-libitum to the animals. As metformin source, metformin-HCl was used and as chrome resource, chromium picolinate was used. Trial groups were formed as control group (basal ration), metformin group (basal ration, added metformin at the level of feed of 20 mg/kg), and chromium picolinate (basal ration, added feed of 1500 ppb Cr) group. When regarded to the results of performance at the end of experiment, it is seen that live weight gain, feed consumption, egg weight, feed conversion ratio (Feed consumption/ egg weight), and egg production were affected at the significant level (p < 0.05). When the results are evaluated in terms of incubation features, hatchability and hatchability of fertile egg ratio were not affected from the treatments. Fertility ratio was significantly affected by metformin and chromium picolinate treatments and fertility rose at the significant level compared to control group (p < 0.05). According to results of experiment, plasma glucose level was not affected by metformin and chromium picolinate treatments. Plasma, total cholesterol, HDL, LDL, and triglyceride levels were significantly affected from insulin receptor stimulators added to ration (p < 0.05). Hormone level of Plasma T3 and T4 were also affected at the significant level from insulin receptor stimulators added to ration (p < 0.05).
Keywords: Chromium picolinate, cholesterol, hormone, metformin, quail.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 13161209 Influence of Raw Materials Ratio and Sintering Temperature on the Properties of the Refractory Mullite-Corundum Ceramics
Authors: L. Mahnicka
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The alumosilicate ceramics with mullite crystalline phase are used in various branches of science and technique. The mullite refractory ceramics with high porosity serve as a heat insulator and as a constructional materials [1], [2]. The purpose of the work was to sinter high porosity ceramic and to increase the quantity of mullite phase in this mullite, mullite-corundum ceramics. Two types of compositions were prepared at during the experiment. The first type is compositions with commercial alumina and silica oxides. The second type is from mixing these oxides with 10, 20 and 30 wt.%. of kaolin. In all samples the Al2O3 and SiO2 were in 2.57:1 ratio, because that was conformed to mullite stechiometric compositions (3Al2O3.2SiO2). The types of alumina oxides were α-Al2O3 (d50=4µm) and γ-Al2O3 (d50=80µm). Ratios of α-: γ-Al2O3 were (1:1) or (1:3). The porous materials were prepared by slip casting of suspension of raw materials. The aluminium paste (0.18 wt.%) was used as a pore former. Water content in the suspensions was 26-47 wt.%. Pore formation occurred as a result of hydrogen formation in chemical reaction between aluminium paste and water [2]. The samples were sintered at the temperature of 1650°C and 1750°C for one hour. The increasing amount of kaolin, α-: γ-Al2O3 at the ratio (1:3) and sintering at the highest temperature raised the quantity of mullite phase. The mullite phase began to dominate over the corundum phase.Keywords: Alumina, Kaolin, Mullite-corundum, Porous refractory ceramics
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28381208 Investigating the Potential for Introduction of Warm Mix Asphalt in Kuwait Using the Volcanic Ash
Authors: H. Al-Baghli, F. Al-Asfour
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The current applied asphalt technology for Kuwait roads pavement infrastructure is the hot mix asphalt (HMA) pavement, including both pen grade and polymer modified bitumen (PMBs), that is produced and compacted at high temperature levels ranging from 150 to 180 °C. There are no current specifications for warm and cold mix asphalts in Kuwait’s Ministry of Public Works (MPW) asphalt standard and specifications. The process of the conventional HMA is energy intensive and directly responsible for the emission of greenhouse gases and other environmental hazards into the atmosphere leading to significant environmental impacts and raising health risk to labors at site. Warm mix asphalt (WMA) technology, a sustainable alternative preferred in multiple countries, has many environmental advantages because it requires lower production temperatures than HMA by 20 to 40 °C. The reduction of temperatures achieved by WMA originates from multiple technologies including foaming and chemical or organic additives that aim to reduce bitumen and improve mix workability. This paper presents a literature review of WMA technologies and techniques followed by an experimental study aiming to compare the results of produced WMA samples, using a water containing additive (foaming process), at different compaction temperatures with the HMA control volumetric properties mix designed in accordance to the new MPW’s specifications and guidelines.
Keywords: Warm-mix asphalt, water-bearing additives, foaming-based process, chemical additives, organic additives.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4891207 Phenolic Compounds and Antimicrobial Properties of Pomegranate (Punica granatum) Peel Extracts
Authors: P. Rahnemoon, M. Sarabi Jamab, M. Javanmard Dakheli, A. Bostan
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In recent years, tendency to use of natural antimicrobial agents in food industry has increased. Pomegranate peels containing phenolic compounds and anti-microbial agents, are counted as valuable source for extraction of these compounds. In this study, the extraction of pomegranate peel extract was carried out at different ethanol/water ratios (40:60, 60:40, and 80:20), temperatures (25, 40, and 55 ˚C), and time durations (20, 24, and 28 h). The extraction yield, phenolic compounds, flavonoids, and anthocyanins were measured. Antimicrobial activity of pomegranate peel extracts were determined against some food-borne microorganisms such as Salmonella enteritidis, Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, Aspergillus niger, and Saccharomyces cerevisiae by agar diffusion and MIC methods. Results showed that at ethanol/water ratio 60:40, 25 ˚C and 24 h maximum amount of phenolic compounds (349.518 mg gallic acid/g dried extract), flavonoids (250.124 mg rutin/g dried extract), anthocyanins (252.047 mg cyanidin3glucoside/100 g dried extract), and the strongest antimicrobial activity were obtained. All extracts’ antimicrobial activities were demonstrated against every tested microorganisms. Staphylococcus aureus showed the highest sensitivity among the tested microorganisms.
Keywords: Antimicrobial agents, phenolic compounds, pomegranate peel, solvent extraction.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 19361206 Evaluation of Azo Dye Toxicity Using Some Haematological and Histopathological Alterations in Fish Catla catla
Authors: Barot Jagruti
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The textile industry plays a major role in the economy of India and on the other side of the coin it is the major source for water pollution. As azo dyes is the largest dye class they are extensively used in many fields such as textile industry, leather tanning industry, paper production, food, color photography, pharmaceuticals and medicine, cosmetic, hair colorings, wood staining, agricultural, biological and chemical research etc. In addition to these, they can have acute and/or chronic effects on organisms depending on their concentration and length of exposure when they discharged as effluent in the environment. The aim of this study was to assess the genotoxic and histotoxic potentials of environmentally relevant concentrations of C. I. Reactive Red 120 (RR 120) on Catla catla, important edible freshwater fingerlings. For this, healthy Catla catla fingerlings were procured from the Government Fish Farm and acclimatized in 100 L capacity and continuously aerated glass aquarium in laboratory for 15 days. According to APHA some physic-chemical parameters were measured and maintained such as temperature, pH, dissolve oxygen, alkalinity, total hardness. Water along with excreta had been changed every 24 hrs. All fingerlings were fed artificial food palates once a day @ body weight. After 15 days fingerlings were grouped in 5 (10 in each) and exposed to various concentrations of RR 120 (Control, 10, 20, 30 and 40 mg.l-1) and samples (peripheral blood and gills, kidney) were collected and analyzed at 96 hrs. All results were compared with the control. Micronuclei (MN), nuclear buds (NB), fragmented-apoptotic (FA) and bi-nucleated (BN) cells in blood smears and in tissues (gills and kidney cells) were observed. Prominent histopathological alterations were noticed in gills such as aneurism, hyperplasia, degenerated central axis, lifting of gill epithelium, curved secondary gill lamellae etc. Similarly kidney showed some detrimental changes like shrunken glomeruli with increased periglomerular space, degenerated renal tubules etc. Both haematological and histopathological changes clearly reveal the toxic potential of RR 120. This work concludes that water pollution assessment can be done by these two biomarkers which provide baseline to the further chromosomal or molecular work.
Keywords: Catla catla, genotoxicity, histopathlogicalchanges, RR 120azo dye.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28011205 Experimental Investigation on Freeze-Concentration Process Desalting for Highly Saline Brines
Authors: H. Al-Jabli
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Using the freeze-melting process for the disposing of high saline brines was the aim of the paper by confirming the performance estimation of the treatment system. A laboratory bench scale freezing technique test unit was designed, constructed, and tested at Doha Research Plant (DRP) in Kuwait. The principal unit operations that have been considered for the laboratory study are: ice crystallization, separation, washing, and melting. The applied process is characterized as “the secondary-refrigerant indirect freezing”, which is utilizing normal freezing concept. The high saline brine was used as definite feed water, i.e. average TDS of 250,000 ppm. Kuwait desalination plants were carried out in the experimental study to measure the performance of the proposed treatment system. Experimental analysis shows that the freeze-melting process is capable of dropping the TDS of the feed water from 249,482 ppm to 56,880 ppm of the freeze-melting process in the two-phase’s course, whereas overall recovery results of the salt passage and salt rejection are 31.11%, 19.05%, and 80.95%, correspondingly. Therefore, the freeze-melting process is encouraging for the proposed application, as it shows on the results, which approves the process capability of reducing a major amount of the dissolved salts of the high saline brine with reasonable sensible recovery. This process might be reasonable with other brine disposal processes.
Keywords: High saline brine, freeze-melting process, ice crystallization, brine disposal process.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10441204 Synthesizing an Artificial Loess for Geotechnical Investigations of Collapsible Soil Behavior
Authors: Hamed Sadeghi, Pouya A. Panahi, Hamed Nasiri, Mohammad Sadeghi
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Collapsible soils like loess comprise an important category of problematic soils for construction purposes and sustainable development. As a result, research on both geological and geotechnical aspects of this type of soil have been in progress for decades. However, considerable natural variability in physical properties of in-situ loess strata even in a single block sample challenges the fundamental laboratory investigations. The reason behind this is that it is somehow impossible to remove the effect of a specific factor like void ratio from fair comparisons to come with a reliable conclusion. In order to cope with this limitation, two types of artificially made dispersive and calcareous loess are introduced which can be easily reproduced in any soil mechanics laboratory provided that all its compositions are known and controlled. The collapse potential is explored for a variety of soil water salinity and lime content and comparisons are made against the natural soil behavior. Trends are reported for the influence of pore water salinity on collapse potential under different osmotic flow conditions. The most important advantage of artificial loess is the ease of controlling cementing agent content like calcite or dispersive potential for studying their influence on mechanical soil behavior.
Keywords: Artificial loess, unsaturated soils, collapse potential, dispersive clays, laboratory tests.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 7421203 Evaluation of Coastal Erosion in the Jurisdiction of the Municipalities of Puerto Colombia and Tubará, Atlántico, Colombia in Google Earth Engine with Landsat and Sentinel 2 Images
Authors: Francisco Javier Reyes Salazar, Héctor Mauricio Ramírez
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The coastal zones are home to mangrove swamps, coral reefs, and seagrass ecosystems, which are the most biodiverse and fragile on the planet. These areas support a great diversity of marine life; they are also extraordinarily important for humans in the provision of food, water, wood, and other associated goods and services; they also contribute to climate regulation. The lack of an automated model that generates information on the dynamics of changes in coastlines and coastal erosion is identified as a central problem. In this paper, coastlines were determined from 1984 to 2020 on the Google Earth Engine platform from Landsat and Sentinel images. Then, we determined the Modified Normalized Difference Water Index (MNDWI) and used Digital Shoreline Analysis System (DSAS) v5.0. Starting from the 2020 coastline; the 10-year prediction (Year 2031) was determined with the erosion of 238.32 hectares and an accretion of 181.96 hectares. For the 20-year prediction (Year 2041) will be presented an erosion of 544.04 hectares and an accretion of 133.94 hectares. The erosion and accretion of Playa Muelle in the municipality of Puerto Colombia were established, which will register the highest value of erosion. The coverage that presented the greatest change was that of artificialized territories.
Keywords: Coastline, coastal erosion, MNDWI, Google Earth Engine, Colombia.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1661202 UF as Pretreatment of RO for Tertiary Treatment of Biologically Treated Distillery Spentwash
Authors: Pinki Sharma, Himanshu Joshi
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Distillery spentwash contains high chemical oxygen demand (COD), biological oxygen demand (BOD), color, total dissolved solids (TDS) and other contaminants even after biological treatment. The effluent can’t be discharged as such in the surface water bodies or land without further treatment. Reverse osmosis (RO) treatment plants have been installed in many of the distilleries at tertiary level in many of the distilleries in India, but are not properly working due to fouling problem which is caused by the presence of high concentration of organic matter and other contaminants in biologically treated spentwash. In order to make the membrane treatment a proven and reliable technology, proper pre-treatment is mandatory. In the present study, ultra-filtration (UF) for pretreatment of RO at tertiary stage has been performed. Operating parameters namely initial pH (pHo: 2–10), trans-membrane pressure (TMP: 4-20 bars) and temperature (T: 15-43°C) were used for conducting experiments with UF system. Experiments were optimized at different operating parameters in terms of COD, color, TDS and TOC removal by using response surface methodology (RSM) with central composite design. The results showed that removal of COD, color and TDS was 62%, 93.5% and 75.5% respectively, with UF, at optimized conditions with increased permeate flux from 17.5 l/m2/h (RO) to 38 l/m2/h (UF-RO). The performance of the RO system was greatly improved both in term of pollutant removal as well as water recovery.Keywords: Bio-digested distillery spentwash, reverse osmosis, Response surface methodology, ultra-filtration.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 25781201 An Effect of Organic Supplements on Stimulating Growth of Vanda and Mokara Seedlings in Tissue Culture
Authors: Kullanart Obsuwan, Chockpisit Thepsithar
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This study aimed to investigate effect of different organic supplements on growth of Vanda and Mokara seedlings. Vanda and Mokara seedlings approximately 0.2 and 0.3 cm. in height were sub-cultured onto VW supplemented with 150 ml/L coconut water, 100 g/L potato extract, 100 g/L ‘Gros Michel’ banana (AAA group) and 100 g/L ‘Namwa’ banana (ABB group). The explants were sub-cultured onto the same medium every month for 3 months. The best medium increased stem height to 0.52 and 0.44 Cm. in Vanda and Mokara respectively was supplemented with coconut water. The maximum fresh weight of Vanda (0.59 g) was found on medium supplemented with ‘Gros Michel’ banana while Mokara cultured on medium supplemented with Potato extract had the maximum fresh weight (0.27 g) and number of roots (5.20 roots/shoot) statistically different (p≤ 0.05) to other treatments. However, Vanda cultured on medium supplemented with ‘Namwa’ banana had the maximum number of roots (3.80 roots/shoot). Our results suggested that growth of different orchid genera was responded diversely to different organic supplements.
Keywords: Fresh weight, in vitro propagation, orchid, plant height.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 32521200 Comparative Study of Sedimentation in Hydraulic Structures using Sharc and Ssiim Soft Wares - A Case of the Dez and Hamidieh Intake Structures in Iran
Authors: A.H. Sajedipoor, N. Hedayat , M. Mashal, R. Nazarzadeh
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Sedimentation formation is a complex hydraulic phenomenon that has emerged as a major operational and maintenance consideration in modern hydraulic engineering in general and river engineering in particular. Sediments accumulation along the river course and their eventual storage in a form of islands affect water intake in the canal systems that are fed by the storage reservoirs. Without proper management, sediment transport can lead to major operational challenges in water distribution system of arid regions like the Dez and Hamidieh command areas. The paper aims to investigate sedimentation in the Western Canal of Dez Diversion Weir using the SHARC model and compare the results with the two intake structures of the Hamidieh dam in Iran using SSIIM model. The objective was to identify the factors which influence the process, check reliability of outcome and provide ways in which to mitigate the implications on operation and maintenance of the structures. Results estimated sand and silt bed loads concentrations to be 193 ppm and 827ppm respectively. This followed ,ore or less similar pattern in Hamidieh where the sediment formation impeded water intake in the canal system. Given the available data on average annual bed loads and average suspended sediment loads of 165ppm and 837ppm in the Dez, there was a significant statistical difference (16%) between the sand grains, whereas no significant difference (1.2%) was find in the silt grain sizes. One explanation for such finding being that along the 6 Km river course there was considerable meandering effects which explains recent shift in the hydraulic behavior along the stream course under investigation. The sand concentration in downstream relative to present state of the canal showed a steep descending curve. Sediment trapping on the other hand indicated a steep ascending curve. These occurred because the diversion weir was not considered in the simulation model. The comparative study showed very close similarities in the results which explains the fact that both software can be used as accurate and reliable analytical tools for simulation of the sedimentation in hydraulic engineering.
Keywords: SHARC, SSIIM, sedimentation, Dez diversion weir, Hamidieh dam, Intake structures
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 17431199 Miocene Warm Tropical Climate: Evidence Based on Oxygen Isotope in Central Java, Indonesia
Authors: Akmaluddin, Koichiro Watanabe, Akihiro Kano, Wartono Rahardjo
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Oxygen and carbon isotopes records of multi-species planktonic, benthic foraminifera and bulk carbonate sample from Central Java Indonesia demonstrate that warm sea surface temperature occurred during the Miocene. Planktonic δ18O values from this study consistently lighter (-4 to -3 ‰PDB) than previous studies that indicate sea surface temperature during Miocene in this area was warm than tropical/equatorial localities. A surprising decrease of oxygen isotopic composition was recorded at ±14 Ma where the maximum of δ18O values is -4.87 ‰PDB for Orbulina universa, -5.02 ‰PDB for Globigerinoides sacculifer and -4.30 ‰PDB for Globoquadrina dehiscens, this event we predict as Middle Miocene Optimum. Warming of sea surface temperature we interpret as related to the development of Western Pacific Warm Pool where warm water from Pacific Ocean through the Indonesian seaway appears to remain during Miocene. Our result also show increasing suddenly of oxygen isotope values of planktic, benthic and bulk carbonate sample from ± 12 Ma, the increasing cooled surface water relatively high degree with Late Miocene global cooling climate or we predict that due to closing of Indonesian Gateway.
Keywords: Oxygen isotope, Foraminifera, Miocene, Paleoclimate, Indonesian.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 16391198 Eco-Design of Multifunctional System Based on a Shape Memory Polymer and ZnO Nanoparticles for Sportswear
Authors: Inês Boticas, Diana P. Ferreira, Ana Eusébio, Carlos Silva, Pedro Magalhães, Ricardo Silva, Raul Fangueiro
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Since the beginning of the 20th century, sportswear has a major contribution to the impact of fashion on our lives. Nowadays, the embracing of sportswear fashion/looks is undoubtedly noticeable, as the modern consumer searches for high comfort and linear aesthetics for its clothes. This compromise lead to the arise of the athleisure trend. Athleisure surges as a new style area that combines both wearability and fashion sense, differentiated from the archetypal sportswear, usually associated to “gym clothes”. Additionally, the possibility to functionalize and implement new technologies have shifted and progressively empowers the connection between the concepts of physical activities practice and well-being, allowing clothing to be more interactive and responsive with its surroundings. In this study, a design inspired in retro and urban lifestyle was envisioned, engineering textile structures that can respond to external stimuli. These structures are enhanced to be responsive to heat, water vapor and humidity, integrating shape memory polymers (SMP) to improve the breathability and heat-responsive behavior of the textiles and zinc oxide nanoparticles (ZnO NPs) to heighten the surface hydrophobic properties. The best results for hydrophobic exhibited superhydrophobic behavior with water contact angle (WAC) of more than 150 degrees. For the breathability and heat-response properties, SMP-coated samples showed an increase in water vapour permeability values of about 50% when compared with non SMP-coated samples. These innovative technological approaches were endorsed to design innovative clothing, in line with circular economy and eco-design principles, by assigning a substantial degree of mutability and versatility to the clothing. The development of a coat and shirt, in which different parts can be purchased separately to create multiple products, aims to combine the technicality of both the fabrics used and the making of the garments. This concept translates itself into a real constructive mechanism through the symbiosis of high-tech functionalities and the timeless design that follows the athleisure aesthetics.
Keywords: Breathability, sportswear and casual clothing, sustainable design, superhydrophobicity.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 10391197 Compressive Strength and Workability Characteristics of Low-Calcium Fly ash-based Self-Compacting Geopolymer Concrete
Authors: M. Fareed Ahmed, M. Fadhil Nuruddin, Nasir Shafiq
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Due to growing environmental concerns of the cement industry, alternative cement technologies have become an area of increasing interest. It is now believed that new binders are indispensable for enhanced environmental and durability performance. Self-compacting Geopolymer concrete is an innovative method and improved way of concreting operation that does not require vibration for placing it and is produced by complete elimination of ordinary Portland cement. This paper documents the assessment of the compressive strength and workability characteristics of low-calcium fly ash based selfcompacting geopolymer concrete. The essential workability properties of the freshly prepared Self-compacting Geopolymer concrete such as filling ability, passing ability and segregation resistance were evaluated by using Slump flow, V-funnel, L-box and J-ring test methods. The fundamental requirements of high flowability and segregation resistance as specified by guidelines on Self Compacting Concrete by EFNARC were satisfied. In addition, compressive strength was determined and the test results are included here. This paper also reports the effect of extra water, curing time and curing temperature on the compressive strength of self-compacting geopolymer concrete. The test results show that extra water in the concrete mix plays a significant role. Also, longer curing time and curing the concrete specimens at higher temperatures will result in higher compressive strength.Keywords: Fly ash, Geopolymer Concrete, Self-compactingconcrete, Self-compacting Geopolymer concrete
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 45601196 Investigations on the Influence of Optimized Charge Air Cooling for a Diesel Passenger Car
Authors: Christian Doppler, Gernot Hirschl, Gerhard Zsiga
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Starting in 2020, an EU-wide CO2-limitation of 95 g/km is scheduled for the average of an OEMs passenger car fleet. Taking that into consideration additional improvement measures of the Diesel cycle are necessary in order to reduce fuel consumption and emissions while boosting, or at the least, keeping performance values at the same time. The present article deals with the possibilities of an optimized air/water charge air cooler, also called iCAC (indirect Charge Air Cooler) for a Diesel passenger car amongst extreme-boundary conditions. In this context, the precise objective was to show the impact of improved intercooling with reference to the engine working process (fuel consumption and NOx-emissions). Several extremeboundaries - e.g. varying ambient temperatures or mountainous routes - that will become very important in the near future regarding RDE (Real Driving emissions) were subject of the investigation. With the introduction of RDE in 2017 (EU6c measure), the controversial NEDC (New European Driving Cycle) will belong to the past and the OEMs will have to avoid harmful emissions in any conceivable real life situation. This is certainly going to lead to optimization-measurements at the powertrain, which again is going to make the implementation of iCACs, presently solely used for the premium class, more and more attractive for compact class cars. The investigations showed a benefit in FC between 1 and 3% for the iCAC in real world conditions.
Keywords: Air/Water-Charge Air Cooler, Co-Simulation, Diesel Working Process, EURO VI Fuel Consumption.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 28961195 Performance Evaluation and Economic Analysis of Minimum Quantity Lubrication with Pressurized/Non-Pressurized Air and Nanofluid Mixture
Authors: M. Amrita, R. R. Srikant, A. V. Sita Rama Raju
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Water miscible cutting fluids are conventionally used to lubricate and cool the machining zone. But issues related to health hazards, maintenance and disposal costs have limited their usage, leading to application of Minimum Quantity Lubrication (MQL). To increase the effectiveness of MQL, nanocutting fluids are proposed. In the present work, water miscible nanographite cutting fluids of varying concentration are applied at cutting zone by two systems A and B. System A utilizes high pressure air and supplies cutting fluid at a flow rate of 1ml/min. System B uses low pressure air and supplies cutting fluid at a flow rate of 5ml/min. Their performance in machining is evaluated by measuring cutting temperatures, tool wear, cutting forces and surface roughness and compared with dry machining and flood machining. Application of nanocutting fluid using both systems showed better performance than dry machining. Cutting temperatures and cutting forces obtained by both techniques are more than flood machining. But tool wear and surface roughness showed improvement compared to flood machining. Economic analysis has been carried out in all the cases to decide the applicability of the techniques.
Keywords: Economic analysis, Machining, Minimum Quantity lubrication, nanofluid.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 22651194 Power Ultrasound Application on Convective Drying of Banana (Musa paradisiaca), Mango (Mangifera indica L.) and Guava (Psidium guajava L.)
Authors: Erika K. Méndez, Carlos E. Orrego, Diana L. Manrique, Juan D. Gonzalez, Doménica Vallejo
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High moisture content in fruits generates post-harvest problems such as mechanical, biochemical, microbial and physical losses. Dehydration, which is based on the reduction of water activity of the fruit, is a common option for overcoming such losses. However, regular hot air drying could affect negatively the quality properties of the fruit due to the long residence time at high temperature. Power ultrasound (US) application during the convective drying has been used as a novel method able to enhance drying rate and, consequently, to decrease drying time. In the present study, a new approach was tested to evaluate the effect of US on the drying time, the final antioxidant activity (AA) and the total polyphenol content (TPC) of banana slices (BS), mango slices (MS) and guava slices (GS). There were also studied the drying kinetics with nine different models from which water effective diffusivities (Deff) (with or without shrinkage corrections) were calculated. Compared with the corresponding control tests, US assisted drying for fruit slices showed reductions in drying time between 16.23 and 30.19%, 11.34 and 32.73%, and 19.25 and 47.51% for the MS, BS and GS respectively. Considering shrinkage effects, Deff calculated values ranged from 1.67*10-10 to 3.18*10-10 m2/s, 3.96*10-10 and 5.57*10-10 m2/s and 4.61*10-10 to 8.16*10-10 m2/s for the BS, MS and GS samples respectively. Reductions of TPC and AA (as DPPH) were observed compared with the original content in fresh fruit data in all kinds of drying assays.Keywords: Banana, drying, effective diffusivity, guava, mango, ultrasound.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2409