Search results for: charge storage

Authors: Charmaine Lamiel, Van Hoa Nguyen, Marjorie Baynosa, Jae-Jin Shim

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Electrochemical supercapacitors have attracted considerable attention because of their high potential as an efficient energy storage system. The combination of carbon-based material and transition metal oxides/sulfides are studied because they have long and improved cycle life as well as high energy and power densities. In this study, a hierarchical mesoporous carbon sphere/nickel cobalt sulfide (CS/Ni-Co-S) core/shell structure was synthesized using a facile hydrothermal method without any further sulfurization or post-heat treatment. The CS/Ni-Co-S core/shell microstructures exhibited a high capacitance of 724 F g−1 at 2 A g−1 in a 6 M KOH electrolyte. After 2000 charge-discharge cycles, it retained 86.1% of its original capacitance, with high Coulombic efficiency of 97.9%. The electrode exhibited a high energy density of 58.0 Wh kg−1 at an energy density of 1440 W kg−1, and high power density of 7200 W kg−1 at an energy density of 34.2 Wh kg−1. The successful synthesis was considered to be simple and cost-effective which supports the viability of this composite as an alternative activated material for high performance supercapacitors.

Keywords: carbon sphere, electrochemical, hydrothermal, nickel cobalt sulfide, supercapacitor

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Authors: Gil Bae, Seung Uk Choi, Jae Eun Lee, Joon Hwa Rho

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Using proprietary engagement partner identity information for the Big 4 audit firms in Korea over the 2001-2011 period, we find that expert engagement partners obtain significantly higher total compensation than do non-expert partners. Importantly, we also find that expert partners increase the number of audit hours compared to their non-expert counterparts. The hourly billing rate, calculated as total fees divided by total audit hours, of expert partners is not higher than that of non-expert partners, indicating that there is no expert partner premium reflected in the hourly rate. This finding suggests that the increase in total audit fees is attributable mainly to the increase in the quantity of audit hours that expert partners work, not from the higher fee per hour. The results are not attributable to auditor selection bias.

Keywords: industry expert partners, expert premiums, audit hours, hourly charge rate

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Authors: Rajasekhar Reddy Poonuru, Anusha Parnem

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Purpose: To formulate proliposome powder of agomelatine, an antipsychotic drug, and to evaluate physicochemical, in vitro characters and effect of surface charge on ex vivo intestinal permeation. Methods: Film deposition technique was employed to develop proliposomal powders of agomelatin with varying molar ratios of lipid Hydro Soy PC L-α-phosphatidylcholine (HSPC) and cholesterol with fixed sum of drug. With the aim to derive free flowing and stable proliposome powder, fluid retention potential of various carriers was examined. Liposome formation and number of vesicles formed for per mm3 up on hydration, vesicle size, and entrapment efficiency was assessed to deduce an optimized formulation. Sodium cholate added to optimized formulation to induce surface charge on formed vesicles. Solid-state characterization (FTIR, DSC, and XRD) was performed with the intention to assess native crystalline and chemical behavior of drug. The in vitro dissolution test of optimized formulation along with pure drug was evaluated to estimate dissolution efficiency (DE) and relative dissolution rate (RDR). Effective permeability co-efficient (Peff(rat)) in rat and enhancement ratio (ER) of drug from formulation and pure drug dispersion were calculated from ex vivo permeation studies in rat ileum. Results: Proliposomal powder formulated with equimolar ratio of HSPC and cholesterol ensued in higher no. of vesicles (3.95) with 90% drug entrapment up on hydration. Neusilin UFL2 was elected as carrier because of its high fluid retention potential (4.5) and good flow properties. Proliposome powder exhibited augmentation in DE (60.3 ±3.34) and RDR (21.2±01.02) of agomelation over pure drug. Solid state characterization studies demonstrated the transformation of native crystalline form of drug to amorphous and/or molecular state, which was in correlation with results obtained from in vitro dissolution test. The elevated Peff(rat) of 46.5×10-4 cm/sec and ER of 2.65 of drug from charge induced proliposome formulation with respect to pure drug dispersion was assessed from ex vivo intestinal permeation studies executed in ileum of wistar rats. Conclusion: Improved physicochemical characters and ex vivo intestinal permeation of drug from charge induced proliposome powder with Neusilin UFL2 unravels the potentiality of this system in enhancing oral delivery of agomelatin.

Keywords: agomelatin, proliposome, sodium cholate, neusilin

Procedia PDF Downloads 136

Authors: Rafik Balti, Nourhene Zayoud, Mohamed Ben Mansour, Abdellah Arhaliass, Anthony Masse

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Application of edible films and coatings with natural active compounds for enhancing storage stability of food products is a promising active packaging approach. Shrimp are generally known as valuable seafood products around the world because of their delicacy and good nutritional. However, shrimp is highly vulnerable to quality deterioration associated with biochemical, microbiological or physical changes during postmortem storage, which results in the limited shelf life of the product. Chitosan is considered as a functional packaging component for maintaining the quality and increasing the shelf life of perishable foods. The present study was conducted to evaluate edible coating of crab chitosan containing variable levels of ethanolic extract of Spirulina on microbiological (mesophilic aerobic, psychrotrophic, lactic acid bacteria, and enterobacteriacea), chemical (pH, TVB-N, TMA-N, PV, TBARS) and sensory (odor, color, texture, taste, and overall acceptance) properties of shrimp during refrigerated storage. Also, textural and color characteristics of coated shrimp were performed. According to the obtained results, crab chitosan in combination with Spirulina extract was very effective in order to extend the shelf life of shrimp during storage in refrigerated condition.

Keywords: food packaging, chitosan, spirulina extract, white shrimp, shelf life

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Authors: Ibrahim Halil Korkmaz, Eren Özceylan, Cihan Çetinkaya

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Logistics function has great potential for increasing sustainable competitive advantage, profitability, productivity, customer satisfaction and decreasing costs in all sectors. The performance of logistics sector, which has such great influence on the overall performance of the economy, attracts more attention of both researchers and sector representatives day by day. The purpose of this study is to determine the effects of research and development expenditures which spent by enterprises operating in the transportation and storage sectors on Turkey’s logistic performance index (LPI). To do so, research and development investment expenditure among the years 2009-2015 of Turkish transportation and storage firms data from the Turkish Statistical Institute and Turkeys country points in the World Bank logistics performance index in the same years data were examined. As the result of the parametric evaluation, it is seen that the research and development expenditures made have a positive effect on the logistic performance of Turkey.

Keywords: logistics performance index, R&D investments, transportation, storage, Turkey

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Authors: Adebisi Moruf Ademola

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Hematite (Fe2O3),commonly known as ‘rust’ which usually surfaced on metal when exposed to some climatic materials. This emerges as a promising candidate for photoelectrochemical (PEC) water splitting due to its favorable physiochemical properties of the narrow band gap (2.1–2.2 eV), chemical stability, nontoxicity, abundance, and low cost. However, inherent limitations such as short hole diffusion length (2–4 nm), high charge recombination rate, and slow oxygen evolution reaction kinetics inhibit the PEC performances of a-Fe2O3 photoanodes. As such, given the narrow bandgap enabling excellent optical absorption, increased charge carrier density and accelerated surface oxidation reaction kinetics become the key points for improved photoelectrochemical performances for a-Fe2O3 photoanodes and metal ion doping as an effective way to promote charge transfer by increasing donor density and improving the electronic conductivity of a-Fe2O3. Hematite attracts enormous efforts with a number of metal ions (Ti, Zr, Sn, Pt ,etc.) as dopants. A facile deposition-annealing process showed greatly enhanced PEC performance due to the increased donor density and reduced electron-hole recombination at the time scale beyond a few picoseconds. Zr doping was also found to enhance the PEC performance of a-Fe2O3 nanorod arrays by reducing the rate of electron-hole recombination. Slow water oxidation reaction kinetics, another main factor limiting the PEC water splitting efficiency of aFe2O3 as photoanodes, was previously found to be effectively improved by surface treatment.

Keywords: deposition-annealing, hematite, metal ion doping, nanorod

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Authors: Amit Kumar, Archana Gupta, Poonam Tandon, E. D. D’Silva

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Nonlinear optical (NLO) materials are the key materials for the fast processing of information and optical data storage applications. In the last decade, materials showing nonlinear optical properties have been the object of increasing attention by both experimental and computational points of view. Chalcones are one of the most important classes of cross conjugated NLO chromophores that are reported to exhibit good SHG efficiency, ultra fast optical nonlinearities and are easily crystallizable. The basic structure of chalcones is based on the π-conjugated system in which two aromatic rings are connected by a three-carbon α, β-unsaturated carbonyl system. Due to the overlap of π orbitals, delocalization of electronic charge distribution leads to a high mobility of the electron density. On a molecular scale, the extent of charge transfer across the NLO chromophore determines the level of SHG output. Hence, the functionalization of both ends of the π-bond system with appropriate electron donor and acceptor groups can enhance the asymmetric electronic distribution in either or both ground and excited states, leading to an increased optical nonlinearity. In this research, the experimental and theoretical study on the structure and vibrations of (2E)-3-[4-(methylsulfanyl) phenyl]-1-(3-bromophenyl) prop-2-en-1-one (3Br4MSP) is presented. The FT-IR and FT-Raman spectra of the NLO material in the solid phase have been recorded. Density functional theory (DFT) calculations at B3LYP with 6-311++G(d,p) basis set were carried out to study the equilibrium geometry, vibrational wavenumbers, infrared absorbance and Raman scattering activities. The interpretation of vibrational features (normal mode assignments, for instance) has an invaluable aid from DFT calculations that provide a quantum-mechanical description of the electronic energies and forces involved. Perturbation theory allows one to obtain the vibrational normal modes by estimating the derivatives of the Kohn−Sham energy with respect to atomic displacements. The molecular hyperpolarizability β plays a chief role in the NLO properties, and a systematical study on β has been carried out. Furthermore, the first order hyperpolarizability (β) and the related properties such as dipole moment (μ) and polarizability (α) of the title molecule are evaluated by Finite Field (FF) approach. The electronic α and β of the studied molecule are 41.907×10-24 and 79.035×10-24 e.s.u. respectively, indicating that 3Br4MSP can be used as a good nonlinear optical material.

Keywords: DFT, MEP, NLO, vibrational spectra

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Authors: Asnate Kirse, Daina Karklina, Sandra Muizniece-Brasava, Ruta Galoburda

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Pulses are high in plant protein and dietary fiber, and contain slowly digestible starches. Innovative products from pulses could increase their consumption and benefit consumer health. This study was conducted to evaluate physicochemical stability of processed cowpea (Vigna unguiculata (L.) Walp. cv. Fradel) and maple pea (Pisum sativum var. arvense L. cv. Bruno) spreads at 5 °C temperature during 62-day storage. Physicochemical stability of pulse spreads was compared after sous vide treatment (80 °C/15 min) and high pressure processing (700 MPa/10 min/20 °C). Pulse spreads were made by homogenizing cooked pulses in a food processor together with salt, citric acid, oil, and bruschetta seasoning. A total of four different pulse spreads were studied: Cowpea spread without and with seasoning, maple pea spread without and with seasoning. Transparent PA/PE and light proof PET/ALU/PA/PP film pouches were used for packaging of pulse spreads under vacuum. The parameters investigated were pH, water activity and mass losses. Pulse spreads were tested on days 0, 15, 29, 42, 50, 57 and 62. The results showed that sous-vide treatment and high pressure processing had an insignificant influence on pH, water activity and mass losses after processing, irrespective of packaging material did not change (p>0.1). pH and water activity of sous-vide treated and high pressure processed pulse spreads in different packaging materials proved to be stable throughout the storage. Mass losses during storage accounted to 0.1% losses. Chosen sous-vide treatment and high pressure processing regimes and packaging materials are suitable to maintain consistent physicochemical quality of the new products during 62-day storage.

Keywords: cowpea, flexible packaging, maple pea, water activity

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Authors: Kerem Ok, Serafettin Senturk, Serdar Aktas, Cem Cevikbas

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Mobile technology is very popular nowadays and it provides a digital world where users can experience many value-added services. Service Providers are also eager to offer diverse value-added services to users such as digital identity, mobile financial services and so on. In this context, the security of data storage in smartphones and the security of communication between the smartphone and service provider are critical for the success of these services. In order to provide the required security functions, the SIM card is one acceptable alternative. Since SIM cards include a Secure Element, they are able to store sensitive data, create cryptographically secure keys, encrypt and decrypt data. In this paper, we design and implement a SIM and a smartphone framework that uses a SIM card for secure key generation, key storage, data encryption, data decryption and digital signing for mobile financial services. Our frameworks show that the SIM card can be used as a controlled Secure Element to provide required security functions for popular e-services such as mobile financial services.

Keywords: SIM card, mobile financial services, cryptography, secure data storage

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Authors: Dongju Kim, Youngjoo Suh, Hyojin Kim, Gyeongyeong Kim

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Acoustic Emission Testing (AET) is widely used to test the structural integrity of an operational hydrogen storage container, and clustering algorithms are frequently used in pattern recognition methods to interpret AET results. However, the interpretation of AET results can vary from user to user as the tuning of the relevant parameters relies on the user's experience and knowledge of AET. Therefore, it is necessary to use a deep learning model to identify patterns in acoustic emission (AE) signal data that can be used to classify defects instead. In this paper, a deep learning-based model for classifying the types of defects in hydrogen storage tanks, using AE sensor waveforms, is proposed. As hydrogen storage tanks are commonly constructed using carbon fiber reinforced polymer composite (CFRP), a defect classification dataset is collected through a tensile test on a specimen of CFRP with an AE sensor attached. The performance of the classification model, using one-dimensional convolutional neural network (1-D CNN) and synthetic minority oversampling technique (SMOTE) data augmentation, achieved 91.09% accuracy for each defect. It is expected that the deep learning classification model in this paper, used with AET, will help in evaluating the operational safety of hydrogen storage containers.

Keywords: acoustic emission testing, carbon fiber reinforced polymer composite, one-dimensional convolutional neural network, smote data augmentation

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Authors: Ahmed Aisa, Tariq Iqbal

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This letter talks about the ready-to-use design of a solar water heating system because, in Canada, the average consumption of hot water per person is approximately 50 to 75 L per day and the average Canadian household uses 225 L. Therefore, this paper will demonstrate the method of designing a solar water heating system with thermal storage. It highlights the renewable hybrid power system, allowing you to obtain a reliable, independent system with the optimization of the ingredient size and at an improved capital cost. The system can provide hot water for a big building. The main power for the system comes from solar panels. Solar Advisory Model (SAM) and HOMER are used. HOMER and SAM are design models that calculate the consumption of hot water and cost for a house. Some results, obtained through simulation, were for monthly energy production, annual energy production, after tax cash flow, the lifetime of the system and monthly energy usage represented by three types of energy. These are system energy, electricity load electricity and net metering credit.

Keywords: water heating, thermal storage, capital cost solar, consumption

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Authors: Richard, Iyan Subiyanto, Chairul Hudaya

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Activated carbon has been playing a significant role for many applications, especially in energy storage devices. However, commercially activated carbons generally require complicated processes and high production costs. Therefore, in this study, an activated carbon originating from green coke waste, that is economically affordable will be used as a carbon source. To synthesize activated carbon, KOH as an activator was employed with variation of C:KOH in ratio of 1:2, 1:3, 1:4, and 1:5, respectively, with an activation temperature of 700°C. The characterizations of activated carbon are obtained from Scanning Electron Microscopy, Energy Dispersive X-Ray, Raman Spectroscopy, and Brunauer-Emmett-Teller. The optimal activated carbon sample with specific surface area of 2,024 m²/g with high carbon content ( > 80%) supported by the high porosity carbon image obtained by SEM was prepared at C:KOH ratio of 1:4. The result shows that the synthesized activated carbon would be an ideal choice for energy storage device applications. Therefore, this study is expected to reduce the costs of activated carbon production by expanding the utilization of petroleum waste.

Keywords: activated carbon, energy storage material, green coke, specific surface area

Procedia PDF Downloads 167

Authors: Malek Mahmoudi, Jonas Keruckas, Dmytro Volyniuk, Jurate Simokaitiene, Juozas V. Grazulevicius

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Host materials have been discovered as one of the most appealing methods for harvesting triplet states in organic materials for application in organic light-emitting diodes (OLEDs). The ideal host-guest system for emission in thermally delayed fluorescence OLEDs with 20% guest concentration for efficient energy transfer has been demonstrated in the present investigation. In this work, 3,3'-bis[9-(4-fluorophenyl) carbazole] (bFPC) has been used as the host, which induces balanced charge carrier transport for high-efficiency OLEDs.For providing a complete characterization of the synthesized compound, photophysical, photoelectrical, charge-transporting, and electrochemical properties of the compound have been examined. Excited-state lifetimes and singlet-triplet energy gaps were measured for characterization of photophysical properties, while thermogravimetric analysis, as well as differential scanning calorimetry measurements, were performed for probing of electrochemical and thermal properties of the compound. The electrochemical properties of this compound were investigated by cyclic voltammetry (CV) method, and ionization potential (IPCV) value of 5.68 eV was observed. UV–Vis absorption and photoluminescence spectrum of a solution of the compound in toluene (10-5 M) showed maxima at 302 and 405 nm, respectively. Photoelectron emission spectrometry was used for the characterization of charge-injection properties of the studied compound in solid. The ionization potential of this material was found to be 5.78 eV, and time-of-flight measurement was used for testing charge-transporting properties and hole mobility estimated using this technique in a vacuum-deposited layer reached 4×10-4 cm2 V-1s-1. Since the compound with high charge mobilities was tested as a host in an organic light-emitting diode. The device was fabricated by successive deposition onto a pre-cleaned indium tin oxide (ITO) coated glass substrate under a vacuum of 10-6 Torr and consisting of an indium-tin-oxide anode, hole injection and transporting layer(MoO3, NPB), emitting layer with bFPC as a host and 4CzIPN (2,4,5,6-tetra(9-carbazolyl)isophthalonitrile) which is a new highly efficient green thermally activated delayed fluorescence (TADF) material as an emitter, an electron transporting layer(TPBi) and lithium fluoride layer topped with aluminum layer as a cathode exhibited the highest maximum current efficiency and power efficiency of 33.9 cd/A and 23.5 lm/W, respectively and the electroluminescence spectrum showed only a peak at 512nm. Furthermore, the new bicarbazole-based compound was tested as a host in thermally activated delayed fluorescence organic light-emitting diodes are reaching luminance of 25300 cd m-2 and external quantum efficiency of 10.1%. Interestingly, the turn-on voltage was low enough (3.8 V), and such a device can be used for highly efficient light sources.

Keywords: thermally-activated delayed fluorescence, host material, ionization energy, charge mobility, electroluminescence

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Authors: Muhammad Randhawa, Muhammad Nadeem

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Guava (Psidium guajava L.) is a vital source of minerals, vitamins, dietary fiber and antioxidants. Owing to highly perishable nature and proning towards chilling injury, diseases, insect-pests and physical damage the main drawbacks of guava after harvesting, present study was designed. Due to its delicacy in physiology, economic importance, effects of pre and postharvest factors and maturity indices, guava fruits should be given prime importance for good quality attributes. In this study guava fruits were stored at 10°C with 80% relative humidity after treating with different levels of sulphate salt of magnesium followed by dipping in cellulose based edible coating hydroxy propyl methyl cellulose (HPMC). The main objective of this coating was to enhance the shelf life of guava by inhibiting the respiration and also by binding the dissolved solids with salt application. Characterization for quality attributes including physical, physiological and bio chemical analysis was performed after every 7 days interval till the fruit remains edible during the storage period of 4 weeks. Finally, data obtained was subjected to statistical analysis. It was concluded on statistical basis that Surahi variety (treated with 5% MgSO4) showed best storage stability and kept its original quality up to almost 23 days during storage.

Keywords: edible coating, guava cultivars, physicochemical attributes, storage

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Authors: Sandeep Bandarwadkar, Tadas Zdankus

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To maintain a comfortable indoor temperature for its residents in the colder season, heating a building is necessary. Due to the expansion in the construction sectors, the consumption of heating energy is increasing. According to Eurostat data, in the European Union, the share of energy consumption of heating energy for space and cooling in residential buildings was around 63% in 2019. These figures indicate that heating energy still accounts for a significant portion of total energy consumption in Europe. Innovation is crucial to reduce energy consumption in buildings and achieve greater energy efficiency and sustainability. It can bring about new solutions that are smarter and more natural energy generation to reduce greenhouse gas emissions. The ground can serve as an effective and sustainable heat accumulator for heating and cooling. The temperature of the ground is higher than that of the ambient air in the colder period and lower in the warmer period. The building deep in the soil could use less thermal energy compared to the above-ground buildings that provide the same amount of thermal comfort. The temperature difference between the soil and the air inside the building decreases as the temperature of the soil increases. In progress, this process generates the condition that acts against heat loss. However, heat dissipates further to the consecutive layers and reaches thermal equilibrium. The charging of the ground by heat and its dissipation through the adjacent soil layers was investigated experimentally. The results of this research showed that 9% of the energy savings in partially underground buildings and 44.4% in completely underground buildings were derived from heating the space. Heat loss to the ground is treated as a charge of the soil by thermal energy. The dependence of the intensity of the charge on time was analysed and presented.

Keywords: heat transfer, accumulation of heat, underground building, soil charge

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Authors: Ehsan Mohseni, Waiching Tang, Shanyong Wang

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Low thermal conductivity of phase change materials (PCMs) affects the thermal performance and energy storage efficiency of latent heat thermal energy storage systems. In the current research, a structural lightweight concrete with function of indoor temperature control was developed using thermal energy storage aggregates (TESA) and nano-titanium (NT). The macro-encapsulated technique was served to incorporate the PCM into the lightweight aggregate through vacuum impregnation. The compressive strength was measured, and the thermal performance of concrete panel was evaluated by using a self-designed environmental chamber. The impact of NT on microstructure was also assessed via scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) tests. The test results indicated that NT was able to increase the compressive strength by filling the micro pores and making the microstructure denser and more homogeneous. In addition, the environmental chamber experiment showed that introduction of NT into TESA improved the heat transfer of composites noticeably. The changes were illustrated by the reduction in peak temperatures in the centre, outside and inside surfaces of concrete panels by the inclusion of NT. It can be concluded that NT particles had the capability to decrease the energy consumption and obtain higher energy storage efficiency by the reduction of indoor temperature.

Keywords: heat transfer, macro-encapsulation, microstructure properties, nanoparticles, phase change material

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Authors: Rayleigh Dada Abu, Halilu Ahmad Shaba

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Siltation is a serious problem that affects public water supply infrastructures such as dams and reservoirs. It is a major problem which threatens the performance and sustainability of dams and reservoirs. It reduces the dam capacity for flood control, potable water supply, changes water stage, reduces water quality and recreational benefits. The focus of this study is the Lower Usuma reservoir. At completion the reservoir had a gross storage capacity of 100 × 106 m3 (100 million cubic metres), a maximum operational level of 587.440 m a.s.l., with a maximum depth of 49 m and a catchment area of 241 km2 at dam site with a daily designed production capacity of 10,000 cubic metres per hour. The reservoir is 1,300 m long and feeds the treatment plant mainly by gravity. The reservoir became operational in 1986 and no survey has been conducted to determine its current storage capacity and rate of siltation. Hydrographic survey of the reservoir by integrated acoustic echo-sounding technique was conducted in November 2012 to determine the level and rate of siltation. The result obtained shows that the reservoir has lost 12.0 meters depth to siltation in 26 years of its operation; indicating 24.5% loss in installed storage capacity. The present bathymetric survey provides baseline information for future work on siltation depth and annual rates of storage capacity loss for the Lower Usuma reservoir.

Keywords: sedimentation, lower Usuma reservoir, acoustic echo sounder, bathymetric survey

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Authors: Jacob Schwartz, Maxim Durach, Aniruddha Mitra, Abbas Rashidi, Glen Sage, Atin Adhikari

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NIOSH (National Institute for Occupational Safety and Health) approved N95 respirators are commonly used by workers in construction sites where there is a large amount of dust being produced from sawing, grinding, blasting, welding, etc., both electrostatically charged and not. A significant portion of airborne particles in construction sites could be nanoparticles created beside coarse particles. The penetration of the particles through the masks may differ depending on the size and charge of the individual particle. In field experiments relevant to this current study, we found that nanoparticles of medium size ranges are penetrating more frequently than nanoparticles of smaller and larger sizes. For example, penetration percentages of nanoparticles of 11.5 – 27.4 nm into a sealed N95 respirator on a manikin head ranged from 0.59 to 6.59%, whereas nanoparticles of 36.5 – 86.6 nm ranged from 7.34 to 16.04%. The possible causes behind this increased penetration of mid-size nanoparticles through mask filters are not yet explored. The objective of this study is to identify causes behind this unusual behavior of mid-size nanoparticles. We have considered such physical factors as Boltzmann distribution of the particles in thermal equilibrium with the air, kinetic energy of the particles at impact on the mask, Stoke’s drag force, and electrostatic forces in the mask stopping the particles. When the particles collide with the mask, only the particles that have enough kinetic energy to overcome the energy loss due to the electrostatic forces and the Stokes’ drag in the mask can pass through the mask. To understand this process, the following assumptions were made: (1) the effect of Stoke’s drag depends on the particles’ velocity at entry into the mask; (2) the electrostatic force is proportional to the charge on the particles, which in turn is proportional to the surface area of the particles; (3) the general dependence on electrostatic charge and thickness means that for stronger electrostatic resistance in the masks and thicker the masks’ fiber layers the penetration of particles is reduced, which is a sensible conclusion. In sampling situations where one mask was soaked in alcohol eliminating electrostatic interaction the penetration was much larger in the mid-range than the same mask with electrostatic interaction. The smaller nanoparticles showed almost zero penetration most likely because of the small kinetic energy, while the larger sized nanoparticles showed almost negligible penetration most likely due to the interaction of the particle with its own drag force. If there is no electrostatic force the fraction for larger particles grows. But if the electrostatic force is added the fraction for larger particles goes down, so diminished penetration for larger particles should be due to increased electrostatic repulsion, may be due to increased surface area and therefore larger charge on average. We have also explored the effect of ambient temperature on nanoparticle penetrations and determined that the dependence of the penetration of particles on the temperature is weak in the range of temperatures in the measurements 37-42°C, since the factor changes in the range from 3.17 10-3K-1 to 3.22 10-3K-1.

Keywords: respiratory protection, industrial hygiene, aerosol, electrostatic force

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

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

Keywords: marketing, ripening, temperature, winter squash

Procedia PDF Downloads 598

Authors: E. Abustam, M. I. Said, M. Yusuf, H. M. Ali

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This study aims to examine the sensory quality of meatballs made from Balinese beef and buffalo meat after the addition of smoke powder prior to storage at the temperatures of 2-5°C for 7 days. This study used meat from Longissimus dorsi muscle of male Balinese cattle aged 3 years and of male buffalo aged 5 years as the main raw materials, and smoke powder as a binder and preservative in making meatballs. The study was based on completely randomized design (CRD) of factorial pattern of 2 x 3 x 2 where factors 1, 2 and 3 included the types of meat (cattle and buffalo), types of smoke powder (oven dried, freeze dried and spray dried) with a level of 2% of the weight of the meat (b/b), and storage duration (0 and 7 days) with three replications respectively. The parameters measured were the meatball sensory quality (scores of tenderness, firmness, chewing residue, and intensity of flavor). The results of this study show that each type of meat has produced different sensory characteristics. The meatballs made from buffalo meat have higher tenderness and elasticity scores than the Balinese beef. Meanwhile, the buffalo meatballs have a lower residue mastication score than the Balinese beef. Each type of smoke powders has produced a relatively similar sensory quality of meatballs. It can be concluded that the smoke powder of 2% of the weight of the meat (w/w) could maintain the sensory quality of the meatballs for 7 days of storage.

Keywords: Balinese beef meatballs, buffalo meatballs, sensory quality, smoke powder

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Authors: A. A. Abdullah, K. A. Lindsay

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The management of a salt-gradient is investigated with respect to the interaction between the solar pond and its associated evaporation pond. Issues considered are the impact of precipitation and the operation of the flushing system with particular reference to the case in which the flushing fluid is pure water. Results suggest that a management strategy based on a flushing system that simply replaces evaporation losses of water from the solar pond and evaporation pond will be optimally efficient. Such a management strategy will maintain the operational viability of a salt-gradient solar pond as a reservoir of cheap heat while simultaneously ensuring that the associated evaporation pond can feed the storage zone of the solar pond with sufficient saturated brine to balance the effect of salt diffusion. Other findings are, first, that once near saturation is achieved in the evaporation pond, the efficacy of the proposed management strategy is relatively insensitive to both the size of the evaporation pond or its depth, and second, small changes in the extraction of heat from the storage zone of a salt-gradient solar pond have an amplified effect on the temperature of that zone. The possibility of boiling of the storage zone cannot be ignored in a well-configured salt-gradient solar pond.

Keywords: aqueous sodium chloride, constitutive expression, solar pond, salt-gradient

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Authors: Sun-Ki Hong, Yong-Ho Cho, Ki-Seok Kim, Tae-Sam Kang

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Piezoelectric actuator is treated as RC load when it is modeled electrically. For some piezoelectric actuator applications, arbitrary voltage is required to actuate. Especially for unidirectional arbitrary voltage driving like as sine wave, some special inverter with circuit that can charge and discharge the capacitive energy can be used. In this case, the difference between power supply level and the object voltage level for RC load is varied. Because the control gain is constant, the controlled output is not uniform according to the voltage difference. In this paper, for charge and discharge circuit for unidirectional arbitrary voltage driving for piezoelectric actuator, the controller gain is controlled according to the voltage difference. With the proposed simple idea, the load voltage can have controlled smoothly although the voltage difference is varied. The appropriateness is proved from the simulation of the proposed circuit.

Keywords: analog voltage inverter, capacitive load, gain control, dc-dc converter, piezoelectric, voltage waveform

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Authors: S. Mahdi S. Kolbadi, Ramezan Ali Alvand, Afrasiab Mirzaei

Abstract:

In this study, to investigate and analyze the seismic behavior of concrete in open rectangular water storage tanks in two-dimensional and three-dimensional spaces, the Finite Element Method has been used. Through this method, dynamic responses can be investigated together in fluid storages system. Soil behavior has been simulated using tanks boundary conditions in linear form. In this research, in addition to flexibility of wall, the effects of fluid-structure interaction on seismic response of tanks have been investigated to account for the effects of flexible foundation in linear boundary conditions form, and a dynamic response of rectangular tanks in two-dimensional and three-dimensional spaces using finite element method has been provided. The boundary conditions of both rigid and flexible walls in two-dimensional finite element method have been considered to investigate the effect of wall flexibility on seismic response of fluid and storage system. Furthermore, three-dimensional model of fluid-structure interaction issue together with wall flexibility has been analyzed under the three components of earthquake. The obtained results show that two-dimensional model is also accurately near to the results of three-dimension as well as flexibility of foundation leads to absorb received energy and relative reduction of responses.

Keywords: dynamic behavior, flexible wall, fluid-structure interaction, water storage tank

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Authors: Miguel Chen Austin, Denis Bruneau, Alain Sempey, Laurent Mora, Alain Sommier

Abstract:

An experimental study in a Plus Energy House (PEH) prototype was conducted in August 2016. It aimed to highlight the energy charge and discharge of a concrete-slab floor submitted to the day-night-cycles heat exchanges in the southwestern part of France and to identify the heat transfer phenomena that take place in both processes: charge and discharge. The main features of this PEH, significant to this study, are the following: (i) a non-active slab covering the major part of the entire floor surface of the house, which include a concrete layer 68 mm thick as upper layer; (ii) solar window shades located on the north and south facades along with a large eave facing south, (iii) large double-glazed windows covering the majority of the south facade, (iv) a natural ventilation system (NVS) composed by ten automatized openings with different dimensions: four are located on the south facade, four on the north facade and two on the shed roof (north-oriented). To highlight the energy charge and discharge processes of the non-active slab, heat flux and temperature measurement techniques were implemented, along with airspeed measurements. Ten “measurement-poles” (MP) were distributed all over the concrete-floor surface. Each MP represented a zone of measurement, where air and surface temperatures, and convection and radiation heat fluxes, were intended to be measured. The airspeed was measured only at two points over the slab surface, near the south facade. To identify the heat transfer phenomena that take part in the charge and discharge process, some relevant dimensionless parameters were used, along with statistical analysis; heat transfer phenomena were identified based on this analysis. Experimental data, after processing, had shown that two periods could be identified at a glance: charge (heat gain, positive values) and discharge (heat losses, negative values). During the charge period, on the floor surface, radiation heat exchanges were significantly higher compared with convection. On the other hand, convection heat exchanges were significantly higher than radiation, in the discharge period. Spatially, both, convection and radiation heat exchanges are higher near the natural ventilation openings and smaller far from them, as expected. Experimental correlations have been determined using a linear regression model, showing the relation between the Nusselt number with relevant parameters: Peclet, Rayleigh, and Richardson numbers. This has led to the determination of the convective heat transfer coefficient and its comparison with the convective heat coefficient resulting from measurements. Results have shown that forced and natural convection coexists during the discharge period; more accurate correlations with the Peclet number than with the Rayleigh number, have been found. This may suggest that forced convection is stronger than natural convection. Yet, airspeed levels encountered suggest that it is natural convection that should take place rather than forced convection. Despite this, Richardson number values encountered indicate otherwise. During the charge period, air-velocity levels might indicate that none air motion occurs, which might lead to heat transfer by diffusion instead of convection.

Keywords: heat flux measurement, natural ventilation, non-active concrete slab, plus energy house

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Authors: Salah A. Al-Garyani, Yousef Swesi

Abstract:

Gas hydrates can be hazardous to upstream operations. On the other hand, the high gas storage capacity of hydrate may be utilized for natural gas storage and transport. Research on the promotion of hydrate formation, as related to natural gas storage and transport, has received relatively little attention. The primary objective of this study is to gain a better understanding of the effects of ionic surfactants, particularly their molecular structures and concentration, on the formation of tetrahydrofuran (THF) hydrate, which is often used as a model hydrate former for screening hydrate promoters or inhibitors. The surfactants studied were sodium n-dodecyl sulfate (SDS), sodium n-hexadecyl sulfate (SHS). Our results show that, at concentrations below the solubility limit, the induction time decreases with increasing surfactant concentration. At concentrations near or above the solubility, however, the surfactant concentration no longer has any effect on the induction time. These observations suggest that the effect of surfactant on THF hydrate formation is associated with surfactant monomers, not the formation of micelle as previously reported. The lowest induction time (141.25 ± 21 s, n = 4) was observed in a solution containing 7.5 mM SDS. The induction time decreases by a factor of three at concentrations near or above the solubility, compared to that without surfactant.

Keywords: tetrahydrofuran, hydrate, surfactant, induction time, monomers, micelle

Procedia PDF Downloads 408

Authors: A. Babou, Y. Kerboua Ziari, Y. Kerkoub

Abstract:

The risks of depletion of fossil fuel reserves and environmental problems caused by their consumption cause to consider alternative energy solutions. Hydrogen appears as a serious solution because its combustion produces only water. The objective of this study is to digitally analyze the effect of operating conditions on the process of absorption of hydrogen in a tank of metal hydride alloy Lanthanum - Nickel (LaNi 5). For this modeling of heat transfer and mass in the tank was carried .The results of numerical weather prediction are in good agreement with the experimental results.

Keywords: hydrogen, storage, energy, fuel, simulation

Procedia PDF Downloads 305

Authors: M. Ghasemi-Varnamkhasti, S. H. Yoosefian. A. Mohammad- Razdari

Abstract:

The effect of 1.0 kJ/m² Ultraviolet-C (UV-C) light on pH, weight loss, color, and firmness of button mushroom (Agaricus bisporus) tissues during 21-days storage at 4 ºC was studied. UV-C irradiation enhanced pH, weight, color parameters, and firmness of mushroom during storage compared to control treatment. However, application of 1.0 kJ/m² UV-C treatment could effectively induce the increase of weight loss, firmness, and pH to 14.53%, 49.82%, and 10.39%, respectively. These results suggest that the application of UV-C irradiation could be an effective method to maintain the postharvest quality of mushrooms.

Keywords: mushroom, polyethylene film, quality, UV-c irradiation

Procedia PDF Downloads 295

Authors: Mohamed Ayoub

Abstract:

We perform computational investigation using density functional theory, B3LYP with aug-cc-pVTZ basis set followed by natural bond orbital analysis (NBO), which provides best single “natural Lewis structure” (NLS) representation of chosen wavefunction (Ψ) with natural resonance theory (NRT) to provide an analysis of molecular electron density in terms of resonance structures (RS) and weights (w). We selected for the study a wide range of gas phase dimers (B…HA), with hydrogen bond dissociation energies (ΔEB…H) that span more than two orders of magnitude. We demonstrate that charge transfer from a donor Lewis-type NBO (nB:) to an acceptor non-Lewis-type NBO (σHA*) is the primary cause for H-bonding not classical electrostatic (dipole-dipole or ionic). We provide a variety of structure, and spectroscopic descriptors to support the conclusion, such as IR frequency shift (ΔνHA), H-bond penetration distance (ΔRB..H), bond order (bB..H), charge-transfer (CTB→HA) and the corresponding donor-acceptor stabilization energy (ΔE(2)).

Keywords: natural bond orbital, hydrogen bonding, electron donor, electron acceptor

Procedia PDF Downloads 436

Authors: M. A. Ghebouli, H. Choutri, B. Ghebouli , M. Fatmi, L. Louail

Abstract:

We employed the density-functional perturbation theory (DFPT) within the generalized gradient approximation (GGA), the local density approximation (LDA) and the virtual-crystal approximation (VCA) to study the effect of composition on the structure, stability, energy gaps, electron effective mass, the dynamic effective charge, optical and acoustical phonon frequencies and static and high dielectric constants of the rock-salt CaxMg1-xSe and CaxMg1-xTe alloys. The computed equilibrium lattice constant and bulk modulus show an important deviation from the linear concentration. From the Voigt-Reuss-Hill approximation, CaxMg1-xSe and CaxMg1-xTe present lower stiffness and lateral expansion. For Ca content ranging between 0.25-0.75, the elastic constants, energy gaps, electron effective mass and dynamic effective charge are predictions. The elastic constants and computed phonon dispersion curves indicate that these alloys are mechanically stable.

Keywords: CaxMg1-xSe, CaxMg1-xTe, band structure, phonon

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Authors: Sanjay Singh, Sushil Kumar, Rashmi Jain

Abstract:

Quantum registering is another pattern in computational hypothesis and a quantum mechanical framework has a few helpful properties like Entanglement. We plan to store data concerning the structure and substance of a basic picture in a quantum framework. Consider a variety of n qubits which we propose to use as our memory stockpiling. In recent years classical processing is switched to quantum image processing. Quantum image processing is an elegant approach to overcome the problems of its classical counter parts. Image storage, retrieval and its processing on quantum machines is an emerging area. Although quantum machines do not exist in physical reality but theoretical algorithms developed based on quantum entangled states gives new insights to process the classical images in quantum domain. Here in the present work, we give the brief overview, such that how entangled states can be useful for quantum image storage and retrieval. We discuss the properties of tripartite Greenberger-Horne-Zeilinger and W states and their usefulness to store the shapes which may consist three vertices. We also propose the techniques to store shapes having more than three vertices.

Keywords: Greenberger-Horne-Zeilinger, image storage and retrieval, quantum entanglement, W states

Procedia PDF Downloads 306