Search results for: water transfer between rivers
Commenced in January 2007
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Edition: International
Paper Count: 10882

Search results for: water transfer between rivers

5062 Regulating Transnational Corporations and Protecting Human Rights: Analyzing the Efficiency of International Legal Framework

Authors: Stellina Jolly

Abstract:

July 18th to August 19th 2013 has gone down in the history of India for undertaking the country’s first environment referendum. The Supreme Court had ruled that the Vedanta Group's bauxite mining project in the Niyamgiri Hills of Orissa will have to get clearance from the gram sabha, which will consider the cultural and religious rights of the tribals and forest dwellers living in Rayagada and Kalahandi districts. In the Niyamgiri hills, people of small tribal hamlets were asked to voice their opinion on bauxite mining in their habitat. The ministry has reiterated its stand that mining cannot be allowed on the Niyamgiri hills because it will affect the rights of the Dongria Kondhs. The tribal person who occupies the Niyamgiri Hills in Eastern India accomplished their first success in 2010 in their struggle to protect and preserve their existence, culture and land against Vedanta a London-based mining giant. In August, 2010 Government of India revoked permission for Vedanta Resources to mine bauxite from hills in Orissa State where the Dongria Kondh live as forest dwellers. This came after various protests and reports including amnesty report wherein it highlighted that an alumina refinery in eastern India operated by a subsidiary of mining company. Vedanta was accused of causing air and water pollution that threatens the health of local people and their access to water. The abuse of human rights by corporate is not a new issue it has occurred in Africa, Asia and other parts of the world. Paper focuses on the instances and extent of human right especially in terms of environment violations by corporations. Further Paper details on corporations and sustainable development. Paper finally comes up with certain recommendation including call for a declaration by United Nations on Corporate environment Human Rights Liability.

Keywords: environment, corporate, human rights, sustainable development

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5061 Exhaust Gas Cleaning Systems on Board Ships and Impact on Crews’ Health: A Feasibility Study Protocol

Authors: Despoina Andrioti Bygvraa, Ida-Maja Hassellöv, George Charalambous

Abstract:

Exhaust gas cleaning systems, also known as scrubbers, are today widely used to allow for the use of High Sulphur Heavy Fuel Oil and still comply with the regulations limiting sulphur content in marine fuels. There are extensive concerns about environmental consequences, especially in the Baltic Sea, from the wide-scale use of scrubbers, as the wash water is acidic (ca pH 3) and contains high concentrations of toxic, carcinogenic, and mutagenic substances. The aim of this feasibility study is to investigate the potential adverse effects on seafarers’ health with the ultimate goal of raising awareness of chemical-related health and safety issues in the shipping environment. The project got funding from the Swedish Foundation. The team will extend previously compiled data on scrubber wash water concentrations of hazardous substances and pH to include the use of strong base in closed-loop scrubbers, and scoping assessment on handling and disposing practices. Based on the findings (a), a systematic review of risk assessment will follow to show the risk of exposures, the establishment of the hazardous levels for human health as well as the respective prevention practices. In addition, the researchers will perform (b) a systematic review to identify facilitators and barriers of the crew on compliance with the safe handling of chemicals. The study will run for 12 months, delivering (a) a risk assessment inventory with risk exposures and (b) a course description of safe handling practices. This feasibility study could provide valuable knowledge on how pollutants found in scrubbers should be considered from a human health perspective to facilitate evidence-based informed decisions in future technology- and policy development to make shipping a safer, healthier, and more attractive workplace.

Keywords: health and safety, seafarers, scrubbers, chemicals, risk exposures

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5060 Steel Concrete Composite Bridge: Modelling Approach and Analysis

Authors: Kaviyarasan D., Satish Kumar S. R.

Abstract:

India being vast in area and population with great scope of international business, roadways and railways network connection within the country is expected to have a big growth. There are numerous rail-cum-road bridges constructed across many major rivers in India and few are getting very old. So there is more possibility of repairing or coming up with such new bridges in India. Analysis and design of such bridges are practiced through conventional procedure and end up with heavy and uneconomical sections. Such heavy class steel bridges when subjected to high seismic shaking has more chance to fail by stability because the members are too much rigid and stocky rather than being flexible to dissipate the energy. This work is the collective study of the researches done in the truss bridge and steel concrete composite truss bridges presenting the method of analysis, tools for numerical and analytical modeling which evaluates its seismic behaviour and collapse mechanisms. To ascertain the inelastic and nonlinear behaviour of the structure, generally at research level static pushover analysis is adopted. Though the static pushover analysis is now extensively used for the framed steel and concrete buildings to study its lateral action behaviour, those findings by pushover analysis done for the buildings cannot directly be used for the bridges as such, because the bridges have completely a different performance requirement, behaviour and typology as compared to that of the buildings. Long span steel bridges are mostly the truss bridges. Truss bridges being formed by many members and connections, the failure of the system does not happen suddenly with single event or failure of one member. Failure usually initiates from one member and progresses gradually to the next member and so on when subjected to further loading. This kind of progressive collapse of the truss bridge structure is dependent on many factors, in which the live load distribution and span to length ratio are most significant. The ultimate collapse is anyhow by the buckling of the compression members only. For regular bridges, single step pushover analysis gives results closer to that of the non-linear dynamic analysis. But for a complicated bridge like heavy class steel bridge or the skewed bridges or complicated dynamic behaviour bridges, nonlinear analysis capturing the progressive yielding and collapse pattern is mandatory. With the knowledge of the postelastic behaviour of the bridge and advancements in the computational facility, the current level of analysis and design of bridges has moved to state of ascertaining the performance levels of the bridges based on the damage caused by seismic shaking. This is because the buildings performance levels deals much with the life safety and collapse prevention levels, whereas the bridges mostly deal with the extent damages and how quick it can be repaired with or without disturbing the traffic after a strong earthquake event. The paper would compile the wide spectrum of modeling to analysis of the steel concrete composite truss bridges in general.

Keywords: bridge engineering, performance based design of steel truss bridge, seismic design of composite bridge, steel-concrete composite bridge

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5059 Study on the Wave Dissipation Performance of Double-Cylinder and Double-Plate Floating Breakwater

Authors: Liu Bijin

Abstract:

Floating breakwaters have several advantages, including being environmentally friendly, easy to construct, and cost-effective regardless of water depth. They have a broad range of applications in coastal engineering. However, they face significant challenges due to the unstable effect of wave dissipation, structural vulnerability, and high mooring system requirements. This paper investigates the wave dissipation performance of a floating breakwater structure. The structure consists of double cylinders, double vertical plates, and horizontal connecting plates. The investigation is carried out using physical model tests and numerical simulation methods based on STAR-CCM+. This paper discusses the impact of wave elements, relative vertical plate heights, and relative horizontal connecting plate widths on the wave dissipation performance of the double-cylinder, double-plate floating breakwater (DCDPFB). The study also analyses the changes in local vorticity and velocity fields around the DCDPFB to determine the optimal structural dimensions. The study found that the relative width of the horizontal connecting plate, the relative height of the vertical plate, and the size of the semi-cylinder are the key factors affecting the wave dissipation performance of the DCDPFB. The transmittance coefficient is minimally affected by the wave height and the depth of water entry. The local vortex and velocity field formed around the DCDPFB are important factors for dissipating wave energy. The test section of the DCDPFB, constructed according to the relative optimal structural dimensions, showed good wave dissipation performance during offshore prototype tests. The test section of DCDPFB, constructed with optimal structural dimensions, exhibits excellent wave dissipation performance in offshore prototype tests.

Keywords: floating breakwater, wave dissipation performance, transmittance coefficient, model test

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5058 Effect of Surfactant Level of Microemulsions and Nanoemulsions on Cell Viability

Authors: Sonal Gupta, Rakhi Bansal, Javed Ali, Reema Gabrani, Shweta Dang

Abstract:

Nanoemulsions (NEs) and microemulsions (MEs) have been an attractive tool for encapsulation of both hydrophilic and lipophillic actives. Both these systems are composed of oil phase, surfactant, co-surfactant and aqueous phase. Depending upon the application and intended use, both oil-in-water and water-in-oil emulsions can be designed. NEs are fabricated using high energy methods employing less percentage of surfactant as compared to MEs which are self assembled drug delivery systems. Owing to the nanometric size of the droplets these systems have been widely used to enhance solubility and bioavailability of natural as well as synthetic molecules. The aim of the present study is to assess the effect of % age of surfactants on cell viability of Vero cells (African Green Monkeys’ Kidney epithelial cells) via MTT assay. Green tea catechin (Polyphenon 60) loaded ME employing low energy vortexing and NE employing high energy ultrasonication were prepared using same excipients (labrasol as oil, cremophor EL as surfactant and glycerol as co-surfactant) however, the % age of oil and surfactant needed to prepare the ME was higher as compared to NE. These formulations along with their excipients (oilME=13.3%, SmixME=26.67%; oilNE=10%, SmixNE=13.52%) were added to Vero cells for 24 hrs. The tetrazolium dye, 3-(4,5-dimethylthia/ol-2-yl)-2,5-diphi-iiyltclrazolium bromide (MTT), is reduced by live cells and this reaction is used as the end point to evaluate the cytoxicity level of a test formulation. Results of MTT assay indicated that oil at different percentages exhibited almost equal cell viability (oilME ≅ oilNE) while surfactant mixture had a significant difference in the cell viability values (SmixME < SmixNE). Polyphenon 60 loaded ME and its PlaceboME showed higher toxicity as compared to Polyphenon 60 loaded NE and its PlaceboNE that can be attributed to the higher concentration of surfactants present in MEs. Another probable reason for high % cell viability of Polyphenon 60 loaded NE might be due to the effective release of Polyphenon 60 from NE formulation that helps in the sustenance of Vero cells.

Keywords: cell viability, microemulsion, MTT, nanoemulsion, surfactants, ultrasonication

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5057 Modelling and Optimisation of Floating Drum Biogas Reactor

Authors: L. Rakesh, T. Y. Heblekar

Abstract:

This study entails the development and optimization of a mathematical model for a floating drum biogas reactor from first principles using thermal and empirical considerations. The model was derived on the basis of mass conservation, lumped mass heat transfer formulations and empirical biogas formation laws. The treatment leads to a system of coupled nonlinear ordinary differential equations whose solution mapped four-time independent controllable parameters to five output variables which adequately serve to describe the reactor performance. These equations were solved numerically using fourth order Runge-Kutta method for a range of input parameter values. Using the data so obtained an Artificial Neural Network with a single hidden layer was trained using Levenberg-Marquardt Damped Least Squares (DLS) algorithm. This network was then fine-tuned for optimal mapping by varying hidden layer size. This fast forward model was then employed as a health score generator in the Bacterial Foraging Optimization code. The optimal operating state of the simplified Biogas reactor was thus obtained.

Keywords: biogas, floating drum reactor, neural network model, optimization

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5056 Adjustable Aperture with Liquid Crystal for Real-Time Range Sensor

Authors: Yumee Kim, Seung-Guk Hyeon, Kukjin Chun

Abstract:

An adjustable aperture using a liquid crystal is proposed for real-time range detection and obtaining images simultaneously. The adjustable aperture operates as two types of aperture stops which can create two different Depth of Field images. By analyzing these two images, the distance can be extracted from camera to object. Initially, the aperture stop has large size with zero voltage. When the input voltage is applied, the aperture stop transfer to smaller size by orientational transition of liquid crystal molecules in the device. The diameter of aperture stop is 1.94mm and 1.06mm. The proposed device has low driving voltage of 7.0V and fast response time of 6.22m. Compact size aperture of 6×6×1.1 mm3 is assembled in conventional camera which contain 1/3” HD image sensor and focal length of 3.3mm that can be used in autonomous. The measured range was up to 5m. The adjustable aperture has high stability due to no mechanically moving parts. This range sensor can be applied to the various field of 3D depth map application which is the Advanced Driving Assistance System (ADAS), drones and manufacturing machine.

Keywords: adjustable aperture, dual aperture, liquid crystal, ranging and imaging, ADAS, range sensor

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5055 Investigation of Distortion and Impact Strength of 304L Butt Joint Using Different Weld Groove

Authors: A. Sharma, S. S. Sandhu, A. Shahi, A. Kumar

Abstract:

The aim of present investigation was to carry out Finite element modeling of distortion in the case of butt weld. 12mm thick AISI 304L plates were butt welded using three different combinations of groove design namely Double U, Double V and Composite. A full simulation of shielded metal arc welding (SMAW) of nonlinear heat transfer is carried out. Aspects like, temperature-dependent thermal properties of AISI stainless steel above liquid phase, the effect of thermal boundary conditions, were included in the model. Since welding heat dissipation characteristics changed due to variable groove design significant changes in the microhardness tensile strength and impact toughness of the joints were observed. The cumulative distortion was found to be least in double V joint followed by the Composite and Double U-joints. All the joints have joint efficiency more than 100%. CVN value of the Double V-groove weld metal was highest. The experimental results and the FEM results were compared and reveal a very good correlation for distortion and weld groove design for a multipass joint with a standard analogy of 83%.

Keywords: AISI 304 L, Butt joint, distortion, FEM, groove design, SMAW

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5054 The Effects of Red Onion (Allium cepa) Extract on Histopathological Appearance of Bursa fabricius in Layers in Open House System

Authors: A. D. Paryuni, R. N. Nataria, R. Wasito

Abstract:

Layer chickens are a poultry commodity that has an important role in producing eggs and meat to support the availability of animal proteins. The layer chickens still have obstacles to increasing their productivity, especially due to poultry diseases which can result not only in decreased egg production but also morbidity and mortality. To overcome this condition, phyto-therapeutic and/or phyto-preventive approaches which are efficacious, safe and cheap are needed. One of the herbal spices from Indonesia which is greatly possible to be promoted as an herbal medicine is a red onion (Allium cepa). The objective of the present study was to identify and determine the effect of red onion extract (Allium cepa) as anti-infection and immuno-modulator of Bursa fabricius in layer chickens raised in an open house system. Eighteen layer chickens at 17 days of age were divided randomly into three group of six each. Those were layer chickens without red onion extract (Group K I), Group K II gave red onion extract via drinking water and Group K III gave red onion extract peroral for 30 days. Water and feed were given ad libitum. Necropsy was conducted every 10 days by taking two samples of layer chickens/Group. Bursa fabricius was processed histopathologically and stained-routinely with hematoxylin-eosinand was then examined under light microscope. The results of the present study indicated that bursaFabricius in layer chickens in Groups K I, K II, and K III that were necropsied at days 10 and 20 had normal histologic structures. However, Bursa fabricius in Group K I at day 30, had vacuolization with mild to moderate large vacuoles containing homogenous eosinophilic fluid and atrophy of lymphoid follicles. Mild vacuolization in the follicle of Bursa fabricius was seen in layer chickens in Group K II, whereas layer chickens in Group K III had normal histologic structures of Bursa fabricius. It was concluded that apparently, red onion extract (Allium cepa) has herbal preventive effects against the pathological lesions in the Bursa fabricius of layer chickens.

Keywords: Bursa fabricius, disease of poultry, hematoxylin-eosin, layer chickens, red onion extract

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5053 Microbial Fuel Cells: Performance and Applications

Authors: Andrea Pietrelli, Vincenzo Ferrara, Bruno Allard, Francois Buret, Irene Bavasso, Nicola Lovecchio, Francesca Costantini, Firas Khaled

Abstract:

This paper aims to show some applications of microbial fuel cells (MFCs), an energy harvesting technique, as clean power source to supply low power device for application like wireless sensor network (WSN) for environmental monitoring. Furthermore, MFC can be used directly as biosensor to analyse parameters like pH and temperature or arranged in form of cluster devices in order to use as small power plant. An MFC is a bioreactor that converts energy stored in chemical bonds of organic matter into electrical energy, through a series of reactions catalysed by microorganisms. We have developed a lab-scale terrestrial microbial fuel cell (TMFC), based on soil that acts as source of bacteria and flow of nutrient and a lab-scale waste water microbial fuel cell (WWMFC), where waste water acts as flow of nutrient and bacteria. We performed large series of tests to exploit the capability as biosensor. The pH value has strong influence on the open circuit voltage (OCV) delivered from TMFCs. We analyzed three condition: test A and B were filled with same soil but changing pH from 6 to 6.63, test C was prepared using a different soil with a pH value of 6.3. Experimental results clearly show how with higher pH value a higher OCV was produced; indeed reactors are influenced by different values of pH which increases the voltage in case of a higher pH value until the best pH value of 7 is achieved. The influence of pH on OCV of lab-scales WWMFC was analyzed at pH value of 6.5, 7, 7.2, 7.5 and 8. WWMFCs are influenced from temperature more than TMFCs. We tested the power performance of WWMFCs considering four imposed values of ambient temperature. Results show how power performance increase proportionally with higher temperature values, doubling the output power from 20° to 40°. The best value of power produced from our lab-scale TMFC was equal to 310 μW using peaty soil, at 1KΩ, corresponding to a current of 0.5 mA. A TMFC can supply proper energy to low power devices of a WSN by means of the design of three stages scheme of an energy management system, which adapts voltage level of TMFC to those required by a WSN node, as 3.3V. Using a commercial DC/DC boost converter, that needs an input voltage of 700 mV, the current source of 0.5 mA, charges a capacitor of 6.8 mF until it will have accumulated an amount of charge equal to 700 mV in a time of 10 s. The output stage includes an output switch that close the circuit after a time of 10s + 1.5ms because the converter can boost the voltage from 0.7V to 3.3V in 1.5 ms. Furthermore, we tested in form of clusters connected in series up to 20 WWMFCs, we have obtained a high voltage value as output, around 10V, but low current value. MFC can be considered a suitable clean energy source to be used to supply low power devices as a WSN node or to be used directly as biosensor.

Keywords: energy harvesting, low power electronics, microbial fuel cell, terrestrial microbial fuel cell, waste-water microbial fuel cell, wireless sensor network

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5052 Characteristics of Smoked Edible Film Made from Myofibril, Collagen and Carrageenan

Authors: Roike Iwan Montolalu, Henny Adeleida Dien, Feny Mentang, Kristhina P. Rahael, Tomy Moga, Ayub Meko, Siegfried Berhimpon

Abstract:

In the last 20 years, packaging materials derived from petrochemicals polymers were widely used as packaging materials. This due to various advantages such as flexible, strong, transparent, and the price is relatively cheap. However, the plastic polymer also has various disadvantages, such as the transmission monomer contamination into the material to be packed, and waste is non-biodegradable. Edible film (EF) is an up to date materials, generated after the biodegradable packaging materials. The advantages of the EF materials, is the materials can be eat together with food, and the materials can be applied as a coating materials for a widely kind of foods especially snack foods. The aims of this research are to produce and to analyze the characteristics of smoked EF made from carrageenan, myofibril and collagen of Black Marlin (Makaira indica) industrial waste. Smoked EF made with an addition of 0.8 % smoke liquid. Three biopolymers i.e. carrageenan, myofibril, and collagen were used as treatments, and homogenate for 1 hours at speed of 1500 rpm. The analysis carried out on the pH and physical properties i.e. thickness, solubility, tensile strength, % elongation, and water vapor transmission rate (WVTR), as well as on the sensory characteristics of texture i.e. wateriness, firmness, elasticity, hardness, and juiciness of the coated products. The result shown that the higher the concentration the higher the thickness of EF, where as for myofibril proteins appeared higher than carrageenan and collagen. Both of collagen and myofibril shown that concentration of 6% was most soluble, while for carrageenan were in concentration of 2 to 2.5%. For tensile strength, carrageenan was significantly higher than myofibril and collagen; while for elongation, collagen film more elastic than carragenan and myofibril protein. Water vapor transmission rate, shown that myofibril protein film lower than carrageenan and collagen film. From sensory assessment of texture, carrageenan has a high elasticity and juiciness, while collagen and myofibril have a high in firmness and hardness.

Keywords: edible film, collagen, myofibril, carrageenan

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5051 Molecular Dynamics Simulation Studies of Thermal Effects Created by High-Intensity, Ultra-Short Pulses Induced Cell Membrane Electroporation

Authors: Jiahui Song

Abstract:

The use of electric fields with high intensity (~ 100kV/cm or higher) and ultra short pulse durations (nanosecond range) has been a recent development. Most of the studies of electroporation have ignored possible thermal effects because of the small duration of the applied voltage pulses. However, it has been predicted membrane temperature gradients ranging from 0.2×109 to 109 K/m. This research focuses on thermal effects that drive for electroporative enhancements, even though the actual temperature values might not have changed appreciably from their equilibrium levels. The dynamics of pore formation with the application of an externally applied electric field is studied on the basis of molecular dynamics (MD) simulations using the GROMACS package. MD simulations of a lipid layer with constant electric field strength of 0.5 V/nm at 25 °C and 47 °C are implemented to simulate the appropriate thermal effects. The GROMACS provides the force fields for the lipid membranes, which is taken to comprise of dipalmitoyl-phosphatidyl-choline (DPPC) molecules. The water model mimicks the aqueous environment surrounding the membrane. Velocities of water and membrane molecules are generated randomly at each simulation run according to a Maxwellian distribution. The high background electric field is typically used in MD simulations to probe electroporation. It serves as an accelerated test of the pore formation process since low electric fields would take inordinately long simulation time. MD simulation shows no pore is formed in a 1-ns snapshot for a DPPC membrane set at a temperature of 25°C after a 0.5 V/nm electric field is applied. A nano-sized pore is clearly seen in a 0.75-ns snapshot on the same geometry, but with the membrane surfaces kept at temperatures of 47°C. And the pore increases at 1 ns. The MD simulation results suggest the possibility that the increase in temperature can result in different degrees of electrically stimulated bio-effects. The results points to the role of thermal effects in facilitating and accelerating the electroporation process.

Keywords: high-intensity, ultra-short, electroporation, thermal effects, molecular dynamics

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5050 Identifying Artifacts in SEM-EDS of Fouled RO Membranes Used for the Treatment of Brackish Groundwater Through Raman and ICP-MS Analysis

Authors: Abhishek Soti, Aditya Sharma, Akhilendra Bhushan Gupta

Abstract:

Fouled reverse osmosis membranes are primarily characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectrometer (EDS) for a detailed investigation of foulants; however, this has severe limitations on several accounts. Apart from inaccuracy in spectral properties and inevitable interferences and interactions between sample and instrument, misidentification of elements due to overlapping peaks is a significant drawback of EDS. This paper discusses this limitation by analyzing fouled polyamide RO membranes derived from community RO plants of Rajasthan treating brackish water via a combination of results obtained from EDS and Raman spectroscopy and cross corroborating with ICP-MS analysis of water samples prepared by dissolving the deposited salts. The anomalous behavior of different morphic forms of CaCO₃ in aqueous suspensions tends to introduce false reporting of the presence of certain heavy metals and rare earth metals in the scales of the fouled RO membranes used for treating brackish groundwater when analyzed using the commonly adopted techniques like SEM-EDS or Raman spectrometry. Peaks of CaCO₃ reflected in EDS spectra of the membrane were found to be misinterpreted as Scandium due to the automatic assignment of elements by the software. Similarly, the morphic forms merged with the dominant peak of CaCO₃ might be reflected as a single peak of Molybdenum in the Raman spectrum. A subsequent ICP-MS analysis of the deposited salts showed that both Sc and Mo were below detectable levels. It is always essential to cross-confirm the results through a destructive analysis method to avoid such interferences. It is further recommended to study different morphic forms of CaCO₃ scales, as they exhibit anomalous properties like reverse solubility with temperature and hence altered precipitation tendencies, for an accurate description of the composition of scales, which is vital for the smooth functioning of RO systems.

Keywords: reverse osmosis, foulant analysis, groundwater, EDS, artifacts

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5049 Investigation of Drought Resistance in Iranian Sesamum Germpelasm

Authors: Fatemeh Najafi

Abstract:

The major stress factor limiting crop growth and development of sesame (Sesamum indicum L.) is drought stress in arid and semiarid regions of the world. For this study the effects of water stress on some qualitative and quantitative traits in sesame germplasm was conducted in the Research Farm of Seed and Plant Improvement Institute, Karaj, in the crop year. Genotypes in a randomized complete block design with three replications in two environments (moisture stress and normal) were studied in regard of the seed weight, capsule weight, grain yield, biomass, plant height, number of capsules per plant, etc. The characteristics were evaluated based on the combined analysis. Irrigation was based on first class evaporation basin. After flowering stage drought stress was applied. The water deficit reduced growth period. Days to reach full ripening decreased so that the reduction was significant at the five percent level. Drought stress reduces yield and plant biomass. Genotypes based on combined analysis of these two traits were significant at the one percent level. Genotypes differ in terms of yield stress in terms of density plots, grain yield, days to first flowering and days to the half of the cap on the confidence level of five percent and traits of days to emergence of the first capsule and days to reach full ripening at the one percent level were significant. Other traits were not significant. The correlation of traits in circumstances of stress the number of seeds per capsule has the greatest impact on performance. The sensitivity and stress tolerance index was calculated. Based on the indicators, (Fars variety) and variety Karaj were identified as the most tolerant genotypes among the studied genotypes to drought stress. The highest sensitivity indicator of stress was related to genotype (FARS).

Keywords: sesamum, drought, stress, germplasm, resistance

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5048 Microbial and Meiofaunal Dynamics in the Intertidal Sediments of the Northern Red Sea

Authors: Hamed A. El-Serehy, Khaled A. Al-Rasheid, Fahad A Al-Misned

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The meiofaunal population fluctuation, microbial dynamic and the composition of the sedimentary organic matter were investigated seasonally in the Egyptian shores along the northern part of Red Sea. Total meiofaunal population densities were extremely low with an annual average of 109 ±26 ind./10 cm2 and largely dominated by nematodes (on annual average from 52% to 94% of total meiofaunal density). The benthic microbial population densities ranged from 0.26±0.02 x 108 to 102.67±18.62 x 108/g dry sediment. Total sedimentary organic matter concentrations varied between 5.8 and 11.6 mg/g and the organic carbon, which was measured as summation of the carbohydrates, proteins and lipids, accounted for only a small fraction of being 32 % of the total organic matter. Chlorophyll a attained very low values and fluctuated between 2 and 11 µg/g. The very low chlorophyll a concentration in the Egyptian coasts along the Red Sea can suggest that the sedimentary organic matter along the Egyptian coasts is dominated by organic detrital and heterotrophic bacteria on one hand, and do not promote carbon transfer towards the higher trophic level on the other hand. However, the present study indicates that the existing of well diversified meiofaunal group, with a total of ten meiofaunal taxa, can serve as food for higher trophic levels in the Red Sea marine ecosystem.

Keywords: bacteria, meiofauna, intertidal sediments, Red Sea

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5047 Characteristics of the Mortars Obtained by Radioactive Recycled Sand

Authors: Claudiu Mazilu, Ion Robu, Radu Deju

Abstract:

At the end of 2011 worldwide there were 124 power reactors shut down, from which: 16 fully decommissioned, 50 power reactors in a decommissioning process, 49 reactors in “safe enclosure mode”, 3 reactors “entombed”, for other 6 reactors it was not yet have specified the decommissioning strategy. The concrete radioactive waste that will be generated from dismantled structures of VVR-S nuclear research reactor from Magurele (e.g.: biological shield of the reactor core and hot cells) represents an estimated amount of about 70 tons. Until now the solid low activity radioactive waste (LLW) was pre-placed in containers and cementation with mortar made from cement and natural fine aggregates, providing a fill ratio of the container of approximately 50 vol. % for concrete. In this paper is presented an innovative technology in which radioactive concrete is crushed and the mortar made from recycled radioactive sand, cement, water and superplasticizer agent is poured in container with radioactive rubble (that is pre-placed in container) for cimentation. Is achieved a radioactive waste package in which the degree of filling of radioactive waste increases substantially. The tests were carried out on non-radioactive material because the radioactive concrete was not available in a good time. Waste concrete with maximum size of 350 mm were crushed in the first stage with a Liebhher type jaw crusher, adjusted to nominal size of 50 mm. Crushed concrete less than 50 mm was sieved in order to obtain useful sort for preplacement, 10 to 50 mm. The rest of the screening > 50 mm obtained from primary crushing of concrete was crushed in the second stage, with different working principles crushers at size < 2.5 mm, in order to produce recycled fine aggregate (sand) for the filler mortar and which fulfills the technical specifications proposed: –jaw crusher, Retsch type, model BB 100; –hammer crusher, Buffalo Shuttle model WA-12-H; presented a series of characteristics of recycled concrete aggregates by predefined class (the granulosity, the granule shape, the absorption of water, behavior to the Los Angeles test, the content of attached mortar etc.), most in comparison with characteristics of natural aggregates. Various mortar recipes were used in order to identify those that meet the proposed specification (flow-rate: 16-50s, no bleeding, min. 30N/mm2 compressive strength of the mortar after 28 days, the proportion of recycled sand used in mortar: min. 900kg/m3) and allow obtaining of the highest fill ratio for mortar. In order to optimize the mortars following compositional factors were varied: aggregate nature, water/cement (W/C) ratio, sand/cement (S/C) ratio, nature and proportion of additive. To confirm the results obtained on a small scale, it made an attempt to fill the mortar in a container that simulates the final storage drums. Was measured the mortar fill ratio (98.9%) compared with the results of laboratory tests and targets set out in the proposed specification. Although fill ratio obtained on the mock-up is lower by 0.8 vol. % compared to that obtained in the laboratory tests (99.7%), the result meets the specification criteria.

Keywords: characteristics, radioactive recycled concrete aggregate, mortars, fill ratio

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5046 High-Frequency Acoustic Microscopy Imaging of Pellet/Cladding Interface in Nuclear Fuel Rods

Authors: H. Saikouk, D. Laux, Emmanuel Le Clézio, B. Lacroix, K. Audic, R. Largenton, E. Federici, G. Despaux

Abstract:

Pressurized Water Reactor (PWR) fuel rods are made of ceramic pellets (e.g. UO2 or (U,Pu) O2) assembled in a zirconium cladding tube. By design, an initial gap exists between these two elements. During irradiation, they both undergo transformations leading progressively to the closure of this gap. A local and non destructive examination of the pellet/cladding interface could constitute a useful help to identify the zones where the two materials are in contact, particularly at high burnups when a strong chemical bonding occurs under nominal operating conditions in PWR fuel rods. The evolution of the pellet/cladding bonding during irradiation is also an area of interest. In this context, the Institute of Electronic and Systems (IES- UMR CNRS 5214), in collaboration with the Alternative Energies and Atomic Energy Commission (CEA), is developing a high frequency acoustic microscope adapted to the control and imaging of the pellet/cladding interface with high resolution. Because the geometrical, chemical and mechanical nature of the contact interface is neither axially nor radially homogeneous, 2D images of this interface need to be acquired via this ultrasonic system with a highly performing processing signal and by means of controlled displacement of the sample rod along both its axis and its circumference. Modeling the multi-layer system (water, cladding, fuel etc.) is necessary in this present study and aims to take into account all the parameters that have an influence on the resolution of the acquired images. The first prototype of this microscope and the first results of the visualization of the inner face of the cladding will be presented in a poster in order to highlight the potentials of the system, whose final objective is to be introduced in the existing bench MEGAFOX dedicated to the non-destructive examination of irradiated fuel rods at LECA-STAR facility in CEA-Cadarache.

Keywords: high-frequency acoustic microscopy, multi-layer model, non-destructive testing, nuclear fuel rod, pellet/cladding interface, signal processing

Procedia PDF Downloads 175
5045 Effects of External and Internal Focus of Attention in Motor Learning of Children with Cerebral Palsy

Authors: Morteza Pourazar, Fatemeh Mirakhori, Fazlolah Bagherzadeh, Rasool Hemayattalab

Abstract:

The purpose of study was to examine the effects of external and internal focus of attention in the motor learning of children with cerebral palsy. The study involved 30 boys (7 to 12 years old) with CP type 1 who practiced throwing beanbags. The participants were randomly assigned to the internal focus, external focus, and control groups, and performed six blocks of 10-trial with attentional focus reminders during a practice phase and no reminders during retention and transfer tests. Analysis of variance (ANOVA) with repeated measures on the last factor was used. The results show that significant main effects were found for time and group. However, the interaction of time and group was not significant. Retention scores were significantly higher for the external focus group. The external focus group performed better than other groups; however, the internal focus and control groups’ performance did not differ. The study concluded that motor skills in Spastic Hemiparetic Cerebral Palsy (SHCP) children could be enhanced by external attention.

Keywords: cerebral palsy, external attention, internal attention, throwing task

Procedia PDF Downloads 296
5044 Assessing the Ecological Status of the Moroccan Mediterranean Sea: An Ecopath Modeling Study

Authors: Salma Aboussalam, Karima Khalil, Khalid Elkalay

Abstract:

In order to understand the structure, functioning, and current state of the Moroccan Mediterranean Sea ecosystem, an Ecopath mass balance model was applied. The model was based on 31 functional groups, which included 21 fish species, 7 invertebrates, 2 primary producers, and one detritus group. The trophic interactions between these groups were analyzed, and the system's average trophic transfer efficiency was found to be 23%. The total primary production and total respiration were calculated to be greater than 1, indicating that the system produces more energy than it respires. The ecosystem was found to have a high level of respiration and consumption flows, and indicators of stability and development showed low values for the Finn cycle index (13.97), system omnivory index (0.18), and average Finn path length (3.09), indicating that the ecosystem is disturbed and has a linear rather than web-like trophic structure. Keystone species were identified using the keystone index and mixed trophic impact analysis, with other demersal invertebrates, zooplankton, and cephalopods found to have a significant impact on other groups.

Keywords: ecopath, food web, trophic flux, moroccan mediterranean sea

Procedia PDF Downloads 59
5043 Relationship between Gully Development and Characteristics of Drainage Area in Semi-Arid Region, NW Iran

Authors: Ali Reza Vaezi, Ouldouz Bakhshi Rad

Abstract:

Gully erosion is a widespread and often dramatic form of soil erosion caused by water during and immediately after heavy rainfall. It occurs when flowing surface water is channelled across unprotected land and washes away the soil along the drainage lines. The formation of gully is influenced by various factors, including climate, drainage surface area, slope gradient, vegetation cover, land use, and soil properties. It is a very important problem in semi-arid regions, where soils have lower organic matter and are weakly aggregated. Intensive agriculture and tillage along the slope can accelerate soil erosion by water in the region. There is little information on the development of gully erosion in agricultural rainfed areas. Therefore, this study was carried out to investigate the relationship between gully erosion and morphometric characteristics of the drainage area and the effects of soil properties and soil management factors (land use and tillage method) on gully development. A field study was done in a 900 km2 agricultural area in Hshtroud township located in the south of East Azarbijan province, NW Iran. Toward this, two hundred twenty-two gullies created in rainfed lands were found in the area. Some properties of gullies, consisting of length, width, depth, height difference, cross section area, and volume, were determined. Drainage areas for each or some gullies were determined, and their boundaries were drawn. Additionally, the surface area of each drainage, land use, tillage direction, and soil properties that may affect gully formation were determined. The soil erodibility factor (K) defined in the Universal Soil Loss Equation (USLE) was estimated based on five soil properties (silt and very fine sand, coarse sand, organic matter, soil structure code, and soil permeability). Gully development in each drainage area was quantified using its volume and soil loss. The dependency of gully development on drainage area characteristics (surface area, land use, tillage direction, and soil properties) was determined using correlation matrix analysis. Based on the results, gully length was the most important morphometric characteristic indicating the development of gully erosion in the lands. Gully development in the area was related to slope gradient (r= -0.26), surface area (r= 0.71), the area of rainfed lands (r= 0.23), and the area of rainfed tilled along the slope (r= 0.24). Nevertheless, its correlation with the area of pasture and soil erodibility factor (K) was not significant. Among the characteristics of drainage area, surface area is the major factor controlling gully volume in the agricultural land. No significant correlation was found between gully erosion and soil erodibility factor (K) estimated by the Universal Soil Loss Equation (USLE). It seems the estimated soil erodibility can’t describe the susceptibility of the study soils to the gully erosion process. In these soils, aggregate stability and soil permeability are the two soil physical properties that affect the actual soil erodibility and in consequence, these soil properties can control gully erosion in the rainfed lands.

Keywords: agricultural area, gully properties, soil structure, USLE

Procedia PDF Downloads 62
5042 Surface Tension and Bulk Density of Ammonium Nitrate Solutions: A Molecular Dynamics Study

Authors: Sara Mosallanejad, Bogdan Z. Dlugogorski, Jeff Gore, Mohammednoor Altarawneh

Abstract:

Ammonium nitrate (NH­₄NO₃, AN) is commonly used as the main component of AN emulsion and fuel oil (ANFO) explosives, that use extensively in civilian and mining operations for underground development and tunneling applications. The emulsion formulation and wettability of AN prills, which affect the physical stability and detonation of ANFO, highly depend on the surface tension, density, viscosity of the used liquid. Therefore, for engineering applications of this material, the determination of density and surface tension of concentrated aqueous solutions of AN is essential. The molecular dynamics (MD) simulation method have been used to investigate the density and the surface tension of high concentrated ammonium nitrate solutions; up to its solubility limit in water. Non-polarisable models for water and ions have carried out the simulations, and the electronic continuum correction model (ECC) uses a scaling of the charges of the ions to apply the polarisation implicitly into the non-polarisable model. The results of calculated density and the surface tension of the solutions have been compared to available experimental values. Our MD simulations show that the non-polarisable model with full-charge ions overestimates the experimental results while the reduce-charge model for the ions fits very well with the experimental data. Ions in the solutions show repulsion from the interface using the non-polarisable force fields. However, when charges of the ions in the original model are scaled in line with the scaling factor of the ECC model, the ions create a double ionic layer near the interface by the migration of anions toward the interface while cations stay in the bulk of the solutions. Similar ions orientations near the interface were observed when polarisable models were used in simulations. In conclusion, applying the ECC model to the non-polarisable force field yields the density and surface tension of the AN solutions with high accuracy in comparison to the experimental measurements.

Keywords: ammonium nitrate, electronic continuum correction, non-polarisable force field, surface tension

Procedia PDF Downloads 208
5041 Data Calibration of the Actual versus the Theoretical Micro Electro Mechanical Systems (MEMS) Based Accelerometer Reading through Remote Monitoring of Padre Jacinto Zamora Flyover

Authors: John Mark Payawal, Francis Aldrine Uy, John Paul Carreon

Abstract:

This paper shows the application of Structural Health Monitoring, SHM into bridges. Bridges are structures built to provide passage over a physical obstruction such as rivers, chasms or roads. The Philippines has a total of 8,166 national bridges as published on the 2015 atlas of the Department of Public Works and Highways (DPWH) and only 2,924 or 35.81% of these bridges are in good condition. As a result, PHP 30.464 billion of the 2016 budget of DPWH is allocated on roads and/or bridges maintenance alone. Intensive spending is owed to the present practice of outdated manual inspection and assessment, and poor structural health monitoring of Philippine infrastructures. As the School of Civil, Environmental, & Geological Engineering of Mapua Institute of Technology (MIT) continuous its well driven passion in research based projects, a partnership with the Department of Science and Technology (DOST) and the DPWH launched the application of Structural Health Monitoring, (SHM) in Padre Jacinto Zamora Flyover. The flyover is located along Nagtahan Boulevard in Sta. Mesa, Manila that connects Brgy. 411 and Brgy. 635. It gives service to vehicles going from Lacson Avenue to Mabini Bridge passing over Legarda Flyover. The flyover is chosen among the many located bridges in Metro Manila as the focus of the pilot testing due to its site accessibility, and complete structural built plans and specifications necessary for SHM as provided by the Bureau of Design, BOD department of DPWH. This paper focuses on providing a method to calibrate theoretical readings from STAAD Vi8 Pro and sync the data to actual MEMS accelerometer readings. It is observed that while the design standards used in constructing the flyover was reflected on the model, actual readings of MEMS accelerometer display a large difference compared to the theoretical data ran and taken from STAAD Vi8 Pro. In achieving a true seismic response of the modeled bridge or hence syncing the theoretical data to the actual sensor reading also called as the independent variable of this paper, analysis using single degree of freedom (SDOF) of the flyover under free vibration without damping using STAAD Vi8 Pro is done. The earthquake excitation and bridge responses are subjected to earthquake ground motion in the form of ground acceleration or Peak Ground Acceleration, PGA. Translational acceleration load is used to simulate the ground motion of the time history analysis acceleration record in STAAD Vi8 Pro.

Keywords: accelerometer, analysis using single degree of freedom, micro electro mechanical system, peak ground acceleration, structural health monitoring

Procedia PDF Downloads 305
5040 Numerical and Experimental Analysis of Temperature Distribution and Electric Field in a Natural Rubber Glove during Microwave Heating

Authors: U. Narumitbowonkul, P. Keangin, P. Rattanadecho

Abstract:

Both numerical and experimental investigation of the temperature distribution and electric field in a natural rubber glove (NRG) during microwave heating are studied. A three-dimensional model of NRG and microwave oven are considered in this work. The influences of position, heating time and rotation angle of NRG on temperature distribution and electric field are presented in details. The coupled equations of electromagnetic wave propagation and heat transfer are solved using the finite element method (FEM). The numerical model is validated with an experimental study at a frequency of 2.45 GHz. The results show that the numerical results closely match the experimental results. Furthermore, it is found that the temperature distribution and electric field increases with increasing heating time. The hot spot zone appears in NRG at the tip of middle finger while the maximum temperature occurs in case of rotation angle of NRG = 60 degree. This investigation provides the essential aspects for a fundamental understanding of heat transport of NRG using microwave energy in industry.

Keywords: electric field, finite element method, microwave energy, natural rubber glove

Procedia PDF Downloads 250
5039 Characterization of Self-Assembly Behavior of 1-Dodecylamine Molecules on Au (111) Surface

Authors: Wan-Tzu Yen, Yu-Chen Luo, I-Ping Liu, Po-Hsuan Yeh, Sheng-Hsun Fu, Yuh-Lang Lee

Abstract:

Self-assembled characteristics and adsorption performance of 1-dodecylamine molecules on gold (Au) (111) surfaces were characterized via cyclic voltammetry (CV), surface-enhanced infrared absorption spectroscopy (SEIRAS) and scanning tunneling microscopy (STM). The present study focused on the formation of 1-dodecylamine (DDA) on a gold surface with respect to the ex-situ arrangement of an adlayer on the Au(111) surface, and phase transition at potential dynamics carried out by EC-STM. This study reveals that alkyl amine molecules were formed an adsorption pattern with highly regular “lie down shape” on Au(111) surface, even in an extreme acid system (pH = 1). Acidic electrolyte (HClO₄) could protonate the surface of alkyl amine of a monolayer of the gold surface when potential shifts to negative. The quite stability of 1-dodecylamine on the gold surface maintained the monolayer across the potential window (0.1-0.8V). This transform model was confirmed by EC-STM. In addition, amine-modified Au(111) electrode adlayer used to examine how to affect an electron transfer across an interface using [Fe(CN)₆]³⁻/[Fe(CN)₆]⁴⁻ redox pair containing 0.1 M HClO₄ solution.

Keywords: cyclic voltammetry, dodecylamine, gold (Au)(111), scanning tunneling microscopy, self-assembled monolayer, surface-enhanced infrared absorption spectroscopy

Procedia PDF Downloads 176
5038 Characterization of the Queuine Salvage Pathway From Bacteria in the Human Parasite Entamoeba Histolytica

Authors: Lotem Sarid, Meirav Trebicz-Geffen, Serge Ankri

Abstract:

Queuosine (Q) is a naturally occurring modified nucleoside that occurs in the first position of transfer RNA anticodons such as Asp, Asn, His, and Tyr. As eukaryotes lack pathways to synthesize queuine, the nucleobase of queuosine, they must obtain it from their diet or gut microbiota. Our previous work investigated the effects of queuine on the physiology of the eukaryotic parasite Entamoeba histolytica and defined the enzyme EhTGT responsible for its incorporation into tRNA. To our best knowledge, it is unknown how E. histolytica salvages Q from gut bacteria. We used N-acryloyl-3-aminophenylboronic acid (APB) PAGE analysis to demonstrate that E. histolytica trophozoites can salvage queuine from Q or E. coli K12 but not from the modified E. coli QueC strain, which cannot produce queuine. Next, we examined the role of EhDUF2419, a protein with homology to DNA glycosylase, as a queuine salvage enzyme in E. histolytica. When EhDUF2419 expression is silenced, it inhibits Q's conversion to queuine, resulting in a decrease in Q-tRNA levels. We also observed that Q protects control trophozoites from oxidative stress (OS), but not siEhDUF2419 trophozoites. Overall, our data reveal that EhDUF2419 is central for the salvaging of queuine from bacteria and for the resistance of the parasite to OS.

Keywords: entamoeba histolytica, epitranscriptomics, gut microbiota, queuine, queuosine, response to oxidative stress, tRNA modification.

Procedia PDF Downloads 105
5037 Mass-Transfer Processes of Textile Dyes Adsorption onto Food Waste Adsorbent

Authors: Amel Asselah, Nadia Chabli, Imane Haddad

Abstract:

The adsorption of methylene blue and congo red dyes in an aqueous solution, on a food waste adsorbent: potato peel, and on a commercial adsorbent: activated carbon powder, was investigated using batch experiments. The objective of this study is the valorization of potato peel by its application in the elimination of these dyes. A comparison of the adsorption efficiency with a commercial adsorbent was carried out. Characterization of the potato peel adsorbent was performed by scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy, Fourier transforms infrared spectroscopy, X-ray diffraction, and X-ray fluorescence. Various parameters were analyzed, in particular: the adsorbent mass, the initial dye concentration, the contact time, the pH, and the temperature. The results reveal that it is about 98% for methylene blue-potato peel, 84% for congo red-potato peel, 84% for methylene blue-activated carbon, and 66% for congo red-activated carbon. The kinetic data were modeled by different equations and revealed that the adsorption of textile dyes on adsorbents follows the model pseudo-second-order, and the particular extra diffusion governs the adsorption mechanism. It has been found that the adsorption process could be described by the Langmuir isotherm.

Keywords: bioadsorbent, waste valorization, adsorptio, textile dyes

Procedia PDF Downloads 71
5036 The Effect of the Weld Current Types on Microstructure and Hardness in Tungsten Inert Gas Welding of the AZ31 Magnesium Alloy Sheet

Authors: Bilge Demir, Ahmet Durgutlu, Mustafa Acarer

Abstract:

In this study, the butt welding of the commercial AZ31 magnesium alloy sheets have been carried out by using Tungsten Inert Gas (TIG) welding process with alternative and pulsed current. Welded samples were examined with regards to hardness and microstructure. Despite some recent developments in welding of magnesium alloys, they have some problems such as porosity, hot cracking, oxide formation and so on. Samples of the welded parts have undergone metallographic and mechanical examination. Porosities and homogeneous micron grain oxides were rarely observed. Orientations of the weld microstructure in terms of heat transfer also were rarely observed and equiaxed grain morphology was dominant grain structure as in the base metal. As results, fusion zone and few locations of the HAZ of the welded samples have shown twin’s grains. Hot cracking was not observed for any samples. Weld bead geometry of the welded samples were evaluated as normal according to welding parameters. In the results, conditions of alternative and pulsed current and the samples were compared to each other with regards to microstructure and hardness.

Keywords: AZ31 magnesium alloy, microstructures, micro hardness TIG welding

Procedia PDF Downloads 374
5035 The Evolution of the Simulated and Observed Star Formation Rates of Galaxies for the Past 13 Billion Years

Authors: Antonios Katsianis

Abstract:

I present the evolution of the galaxy Star Formation Rate Function (SFRF), star formation rate-stellar mass relation (SFR-M*) and Cosmic Star Formation Rate Density (CSFRD) of z = 0-8 galaxies employing both the Evolution and Assembly of GaLaxies and their Environments (EAGLE) simulations and a compilation of UV, Ha, radio and IR data. While I present comparisons between the above, I evaluate the effect and importance of supernovae/active galactic nuclei feedback. The relation between the star formation rate and stellar mass of galaxies represents a fundamental constraint on galaxy formation, and has been studied extensively both in observations and cosmological hydrodynamic simulations. However, a tension between the above is reported in the literature. I present the evolution of the SFR-M* relation and demonstrate the inconsistencies between observations that are retrieved using different methods. I employ cosmological hydrodynamic simulations combined with radiative transfer methods and compare these with a range of observed data in order to investigate further the root of this tension. Last, I present insights about the scatter of the SFR-M* relation and investigate which mechanisms (e.g. feedback) drive its shape and evolution.

Keywords: cosmological simulations, galaxy formation and evolution, star formation rate, stellar masses

Procedia PDF Downloads 130
5034 High-Frequency Cryptocurrency Portfolio Management Using Multi-Agent System Based on Federated Reinforcement Learning

Authors: Sirapop Nuannimnoi, Hojjat Baghban, Ching-Yao Huang

Abstract:

Over the past decade, with the fast development of blockchain technology since the birth of Bitcoin, there has been a massive increase in the usage of Cryptocurrencies. Cryptocurrencies are not seen as an investment opportunity due to the market’s erratic behavior and high price volatility. With the recent success of deep reinforcement learning (DRL), portfolio management can be modeled and automated. In this paper, we propose a novel DRL-based multi-agent system to automatically make proper trading decisions on multiple cryptocurrencies and gain profits in the highly volatile cryptocurrency market. We also extend this multi-agent system with horizontal federated transfer learning for better adapting to the inclusion of new cryptocurrencies in our portfolio; therefore, we can, through the concept of diversification, maximize our profits and minimize the trading risks. Experimental results through multiple simulation scenarios reveal that this proposed algorithmic trading system can offer three promising key advantages over other systems, including maximized profits, minimized risks, and adaptability.

Keywords: cryptocurrency portfolio management, algorithmic trading, federated learning, multi-agent reinforcement learning

Procedia PDF Downloads 105
5033 Numerical Study of Heat Transfer in Silica Aerogel

Authors: Amal Maazoun, Abderrazak Mezghani, Ali Ben Moussa

Abstract:

Aerogel consists of a ramified and inter-connected solid skeleton enclosing a very important number of nano-sized pores filled with air that occupies most of the volume and makes very low density. The thermal conductivity of this material can reach lower values than those of any other material, and it changes with the type of the aerogel and its composition. So, in order to explain the causes of the super-insulation of our material and to determine the factors in which depends on its conductivity we used a numerical simulation. We have developed a numerical code that generates random fractal structure of silica aerogel with pre-defined concentration, properties of the backbone and the gas in the pores as well as the size of the particles. The calculation of the conductivity at any point of domain shows that it is not constant and that it depends on the pore size and the location in the pore. A numerical method based on resolution by inversion of block tridiagonal matrices is used to calculate the equivalent thermal conductivity of the whole fractal structure. The average conductivity calculated for each concentration is in good agreement with those of typical aerogels. And we found that the equivalent thermal conductivity of a silica aerogel depends strongly not only on the porosity but also on the tortuosity of the solid backbone.

Keywords: aerogel, fractal structure, numerical study, porous media, thermal conductivity

Procedia PDF Downloads 267