Search results for: temperature dependent viscosity

Authors: Young Mun Lee, Seon Ho Kim, Seok Min Choi, JeongJu Kim, Seungyeong Choi, Hyung Hee Cho

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To decrease sulfur oxide in the flue gas from coal power plant, a flue gas de-sulfurization facility is operated. In the reactor, a chemical reaction occurs with a temperature change of the gas so that sulfur oxide is removed and cleaned air is emitted. In this process, temperature change induces a serious problem which is a cold erosion of stack. To solve this problem, the rotary heat exchanger is managed before the stack. In the heat exchanger, a heating element is equipped to increase a heat transfer area. Heat transfer and pressure loss is a big issue to improve a performance. In this research, thermal-fluid characteristics of the heating element are analyzed by computational fluid dynamics. Fouling simulation is also conducted to calculate a performance of heating element. Numerical analysis is performed on the situation where plugging phenomenon has already occurred and existed in the inlet region of the heating element. As the pressure of the rear part of the plugging decreases suddenly and the flow velocity becomes slower, it is found that the flow is gathered from both sides as it develops in the flow direction, and it is confirmed that the pressure difference due to plugging is increased.

Keywords: heating element, plugging, rotary heat exchanger, thermal fluid characteristics

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Authors: Ila Shukla, Lubna Azmi, Shyam Sunder Gupta, C. V. Rao

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Treatments against Hepatitis-C virus (HCV) are already available, but the current high cost of such treatments limit them to wealthy patients only. Hence our current study is aimed at the rectification of HCV infection by using Lichen rangiferinus (LRE) extract in in vitro cultures. Anti-HCV activity of the given extract was evaluated using the virus grown in cell culture (HCVcc). Two control inhibitors, erlotinib and telaprevir, were systematically included in each experiment. At the end of the incubation period, we evaluated cell viability and viral replication. The LRE inhibited the growth of HCV in a dose dependent manner.

Keywords: Erlotinib, Hepatitis C, Lichen rangiferinus, Telaprevir

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Authors: Anton G. Kalmykov, Andrew Yu. Bychkov, Georgy A. Kalmykov

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Nowadays, most oil reserves in Russia and all over the world are hard to recover. That is the reason oil companies are searching for new sources for hydrocarbon production. One of the sources might be high-carbon formations with unconventional reservoirs. Bazhenov formation is a huge source rock formation located in West Siberia, which contains unconventional reservoirs on some of the areas. These reservoirs are formed by secondary processes with low predicting ratio. Only one of five wells is drilled through unconventional reservoirs, in others kerogen has low thermal maturity, and they are of low petroliferous. Therefore, there was a request for tertiary methods for in-situ cracking of kerogen and production of oil. Laboratory experiments of Bazhenov formation rock hydrous pyrolysis were used to investigate features of the oil generation process. Experiments on Bazhenov rocks with a different mineral composition (silica concentration from 15 to 90 wt.%, clays – 5-50 wt.%, carbonates – 0-30 wt.%, kerogen – 1-25 wt.%) and thermal maturity (from immature to late oil window kerogen) were performed in a retort under reservoir conditions. Rock samples of 50 g weight were placed in retort, covered with water and heated to the different temperature varied from 250 to 400°C with the durability of the experiments from several hours to one week. After the experiments, the retort was cooled to room temperature; generated hydrocarbons were extracted with hexane, then separated from the solvent and weighted. The molecular composition of this synthesized oil was then investigated via GC-MS chromatography Characteristics of rock samples after the heating was measured via the Rock-Eval method. It was found, that the amount of synthesized oil and its composition depending on the experimental conditions and composition of rocks. The highest amount of oil was produced at a temperature of 350°C after 12 hours of heating and was up to 12 wt.% of initial organic matter content in the rocks. At the higher temperatures and within longer heating time secondary cracking of generated hydrocarbons occurs, the mass of produced oil is lowering, and the composition contains more hydrocarbons that need to be recovered by catalytical processes. If the temperature is lower than 300°C, the amount of produced oil is too low for the process to be economically effective. It was also found that silica and clay minerals work as catalysts. Selection of heating conditions allows producing synthesized oil with specified composition. Kerogen investigations after heating have shown that thermal maturity increases, but the yield is only up to 35% of the maximum amount of synthetic oil. This yield is the result of gaseous hydrocarbons formation due to secondary cracking and aromatization and coaling of kerogen. Future investigations will allow the increase in the yield of synthetic oil. The results are in a good agreement with theoretical data on kerogen maturation during oil production. Evaluated trends could be tooled up for in-situ oil generation by shale rocks thermal action.

Keywords: Bazhenov formation, fossil fuels, hydropyrolysis, synthetic oil

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Authors: Szymon Kuczynski

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Poland is characterized by the presence of numerous sedimentary basins and hydrocarbon provinces. Since 2006 exploration for hydrocarbons in Poland become gradually more focus on new unconventional targets, particularly on the shale gas potential of the Upper Ordovician and Lower Silurian in the Baltic-Podlasie-Lublin Basin. The first forecast prepared by US Energy Information Administration in 2011 indicated to 5.3 Tcm of natural gas. In 2012, Polish Geological Institute presented its own forecast which estimated maximum reserves on 1.92 Tcm. The difference in the estimates was caused by problems with calculations of the initial amount of adsorbed, as well as free, gas trapped in shale rocks (GIIP - Gas Initially in Place). This value is dependent from sorption capacity, gas saturation and mutual interactions between gas, water, and rock. Determination of the reservoir type in the initial exploration phase brings essential knowledge, which has an impact on decisions related to the production. The study of porosity impact for phase envelope shift eliminates errors and improves production profitability. Confinement phenomenon affects flow characteristics, fluid properties, and phase equilibrium. The thermodynamic behavior of confined fluids in porous media is subject to the basic considerations for industrial applications such as hydrocarbons production. In particular the knowledge of the phase equilibrium and the critical properties of the contained fluid is essential for the design and optimization of such process. In pores with a small diameter (nanopores), the effect of the wall interaction with the fluid particles becomes significant and occurs in shale formations. Nano pore size is similar to the fluid particles’ diameter and the area of particles which flow without interaction with pore wall is almost equal to the area where this phenomenon occurs. The molecular simulation studies have shown an effect of confinement to the pseudo critical properties. Therefore, the critical parameters pressure and temperature and the flow characteristics of hydrocarbons in terms of nano-scale are under the strong influence of fluid particles with the pore wall. It can be concluded that the impact of a single pore size is crucial when it comes to the nanoscale because there is possible the above-described effect. Nano- porosity makes it difficult to predict the flow of reservoir fluid. Research are conducted to explain the mechanisms of fluid flow in the nanopores and gas extraction from porous media by desorption.

Keywords: adsorption, capillary condensation, phase envelope, nanopores, unconventional natural gas

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Authors: Ehsan Arabian, Thomas Sattelmayer

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The formation of nitrogen dioxide NO2 in the exhaust duct of a MAN dual fuel test engine has been investigated numerically. The dual fuel engine concept with premixed lean methane combustion ignited through diesel pilot flames reveals high potential for the abatement of the NOx formation. The drawback of this combustion method, however, is the high NO2 formation due to the increasing concentration of unburned hydrocarbons. This promotes the conversion of NO to NO2, which is toxic and characterized through its yellow color. The results presented in this paper cover a wide range of engine operation points from full load to part load for different air to fuel ratios. The effects of temperature, pressure and concentrations of unburned methane and nitric oxide on NO2 formation in the exhaust duct has been investigated on the basis of a zero-dimensional well stirred reactor model implemented in Cantera, which calculates the steady state of a uniform composition for a certain residence time. It can be shown that the simulated conversion of NO to NO2 match the experimental results fairly well. The partial oxidation of methane followed by CO production can be predicted as well. It can also be concluded that the lower temperature limit for which no conversion takes place, depends mainly on the concentration of the unburned hydrocarbons in the exhaust.

Keywords: cantera, dual fuel engines, exhaust tract, numerical modeling of NO2 formation, well stirred reactor

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Authors: Hsyi-En Cheng, Ying-Yi Liou

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Metal-oxide semiconductor (MOS) gas sensors are widely used in the gas-detection market due to their high sensitivity, fast response, and simple device structures. However, the high working temperature of MOS gas sensors makes them difficult to integrate with the appliance or consumer goods. One-dimensional (1-D) nanostructures are considered to have the potential to lower their working temperature due to their large surface-to-volume ratio, confined electrical conduction channels, and small feature sizes. Unfortunately, the difficulty of fabricating 1-D nanostructure electrodes has hindered the development of low-temperature MOS gas sensors. In this work, we proposed a method to fabricate nanotube-arrays, and the SnO₂ nanotube-array sensors with different wall thickness were successfully prepared and examined. The fabrication of SnO₂ nanotube arrays incorporates the techniques of barrier-free anodic aluminum oxide (AAO) template and atomic layer deposition (ALD) of SnO₂. First, 1.0 µm Al film was deposited on ITO glass substrate by electron beam evaporation and then anodically oxidized by five wt% phosphoric acid solution at 5°C under a constant voltage of 100 V to form porous aluminum oxide. As the Al film was fully oxidized, a 15 min over anodization and a 30 min post chemical dissolution were used to remove the barrier oxide at the bottom end of pores to generate a barrier-free AAO template. The ALD using reactants of TiCl4 and H₂O was followed to grow a thin layer of SnO₂ on the template to form SnO₂ nanotube arrays. After removing the surface layer of SnO₂ by H₂ plasma and dissolving the template by 5 wt% phosphoric acid solution at 50°C, upright standing SnO₂ nanotube arrays on ITO glass were produced. Finally, Ag top electrode with line width of 5 μm was printed on the nanotube arrays to form SnO₂ nanotube-array sensor. Two SnO₂ nanotube-arrays with wall thickness of 30 and 60 nm were produced in this experiment for the evaluation of gas sensing ability. The flat SnO₂ films with thickness of 30 and 60 nm were also examined for comparison. The results show that the properties of ALD SnO₂ films were related to the deposition temperature. The films grown at 350°C had a low electrical resistivity of 3.6×10-3 Ω-cm and were, therefore, used for the nanotube-array sensors. The carrier concentration and mobility of the SnO₂ films were characterized by Ecopia HMS-3000 Hall-effect measurement system and were 1.1×1020 cm-3 and 16 cm3/V-s, respectively. The electrical resistance of SnO₂ film and nanotube-array sensors in air and in a 5% H₂-95% N₂ mixture gas was monitored by Pico text M3510A 6 1/2 Digits Multimeter. It was found that, at 200 °C, the 30-nm-wall SnO₂ nanotube-array sensor performs the highest responsivity to 5% H₂, followed by the 30-nm SnO₂ film sensor, the 60-nm SnO₂ film sensor, and the 60-nm-wall SnO₂ nanotube-array sensor. However, at temperatures below 100°C, all the samples were insensitive to the 5% H₂ gas. Further investigation on the sensors with thinner SnO₂ is necessary for improving the sensing ability at temperatures below 100 °C.

Keywords: atomic layer deposition, nanotube arrays, gas sensor, tin dioxide

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Authors: Shafqat Wahab, Waseem Tahir, Manzoor Ahmad, Sarfraz Khan, M. Azam

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Optimization and analysis of tool flank wear width and surface finish of alloy steel rods are studied in the presence of cryogenic media (LN2) by using Tungsten Carbide Insert (CNMG 120404- WF 4215). Robust design concept of Taguchi L9(34) method and ANOVA is applied to determine the contribution of key cutting parameters and their optimum conditions. Through analysis, it revealed that cryogenic impact is more significant in reduction of the tool flank wear width while surface finish is mostly dependent on feed rate.

Keywords: turning, cryogenic fluid, liquid nitrogen, flank wear, surface roughness, taguchi

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Authors: Zuoyong Zhang, Min Yu, Jinlong Zhao, Shudong He

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The Maillard reaction can produce the flavor enhancing substance through the chemical crosslinking between free amino group of the protein or polypeptide with the carbonyl of the reducing sugar. In this research, solutions of rapeseed meal peptide and D-xylose with or without L-cysteine (RXC or RX) were heated over a range of temperatures (80-140 °C) for 2 h. It was observed that RXs had a severe browning,while RXCs accompanied by more pH decrement with the temperature increasing. Then the correlation among data of quantitative sensory descriptive analysis, free amino acid (FAA) and GC–MS of RXCs and RXs were analyzed using the partial least square regression method. Results suggested that the Maillard reaction product (MRPs) with cysteine formed at 120 °C (RXC-120) had greater sensory properties especially meat-like flavor compared to other MRPs. Meanwhile, it revealed that glutamic and glycine not only had a positive contribution to meaty aroma but also showed a significant and positive influence on umami taste of RXs based on the FAA data. Moreover, the sulfur-containing compounds showed a significant positive correlation with the meat-like flavor of RXCs, while RXs depended on furans and nitrogenous-containing compounds with more caramel-like flavor. Therefore, a MRP with strong meaty flavor could be obtained at 120 °C by addition of cysteine.

Keywords: rapeseed meal, Maillard reaction, sensory characteristics, FAA, GC–MS, partial least square regression

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Authors: Tânia F. C. V. Silva, Eloísa S. S. Vieira, João Pinto da Costa, Rui A. R. Boaventura, Vitor J. P. Vilar

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Sanitary landfill leachates are characterized as a complex mixture of diverse organic and inorganic contaminants, which are usually removed by combining different treatment processes. Due to its simplicity, reliability, high cost-effectiveness and high nitrogen content (mostly under the ammonium form) inherent in this type of effluent, the activated sludge biological process is almost always applied in leachate treatment plants (LTPs). The purpose of this work is to assess the effect of the main nitrification and denitrification variables on the nitrogen's biological removal, from mature leachates. The leachate samples were collected after an aerated lagoon, at a LTP nearby Porto, presenting a high amount of dissolved organic carbon (1.0-1.3 g DOC/L) and ammonium nitrogen (1.1-1.7 g NH4+-N/L). The experiments were carried out in a 1-L lab-scale batch reactor, equipped with a pH, temperature and dissolved oxygen (DO) control system, in order to determine the reaction kinetic constants at unchanging conditions. The nitrification reaction rate was evaluated while varying the (i) operating temperature (15, 20, 25 and 30ºC), (ii) DO concentration interval (0.5-1.0, 1.0-2.0 and 2.0-4.0 mg/L) and (iii) solution pH (not controlled, 7.5-8.5 and 6.5-7.5). At the beginning of most assays, it was verified that the ammonium stripping occurred simultaneously to the nitrification, reaching up to 37% removal of total dissolved nitrogen. The denitrification kinetic constants and the methanol consumptions were calculated for different values of (i) volatile suspended solids (VSS) content (25, 50 and 100 mL of centrifuged sludge in 1 L solution), (ii) pH interval (6.5-7.0, 7.5-8.0 and 8.5-9.0) and (iii) temperature (15, 20, 25 and 30ºC), using effluent previously nitrified. The maximum nitrification rate obtained was 38±2 mg NH4+-N/h/g VSS (25ºC, 0.5-1.0 mg O2/L, pH not controlled), consuming 4.4±0.3 mg CaCO3/mg NH4+-N. The highest denitrification rate achieved was 19±1 mg (NO2--N+NO3--N)/h/g VSS (30ºC, 50 mL of sludge and pH between 7.5 and 8.0), with a C/N consumption ratio of 1.1±0.1 mg CH3OH/mg (NO2--N+NO3--N) and an overall alkalinity production of 3.7±0.3 mg CaCO3/mg (NO2--N+NO3--N). The denitrification process showed to be sensitive to all studied parameters, while the nitrification reaction did not suffered significant change when DO content was changed.

Keywords: mature sanitary landfill leachate, nitrogen removal, nitrification and denitrification parameters, lab-scale activated sludge biological reactor

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Authors: Jaharlal Debbarma

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The ecological crisis has become a threat to earth’s well-being. Man’s ambitious desire of wealth, pleasure, fame, longevity and happiness has extracted natural resources so vastly that it is unable to sustain a healthy life. Man’s greed for wealth and power has caused the setting up of vast factories which further created the problem of air, water and noise pollution, which have adversely affected both fauna and flora.It is no secret that man uses his inherent powers of reason, intelligence and creativity to change his environment for his advantage. But man is not aware that the moral force he himself creates brings about corresponding changes in his environment to his weal or woe whether he likes it or not. As we are facing the global warming and the nature’s gift such as air and water has been so drastically polluted with disastrous consequences that man seek for a ways and means to overcome all this pollution problem as his health and life sustainability has been threaten and that is where man try to question about the moral ethics and value.It is where Buddhist philosophy has been emphasized deeply which gives us hope for overcoming this entire problem as Buddha himself emphasized in eradicating human suffering and Buddhism is the strongest form of humanism we have. It helps us to learn to live with responsibility, compassion, and loving kindness.It teaches us to be mindful in our action and thought as the environment unites every human being. If we fail to save it we will perish. If we can rise to meet the need to all which ecology binds us - humans, other species, other everything will survive together.My paper will look into the theory of Dependent Origination (Pratītyasamutpāda), Buddhist understanding of suffering (collective suffering), and Non-violence (Ahimsa) and an effort will be made to provide a new vision to Buddhist ecological perspective. The above Buddhist philosophy will be applied to ethical values and belief systems of modern society. The challenge will be substantially to transform the modern individualistic and consumeristic values. The stress will be made on the interconnectedness of the nature and the relation between human and planetary sustainability. In a way environmental crisis will be referred to “spiritual crisis” as A. Gore (1992) has pointed out. The paper will also give important to global consciousness, as well as to self-actualization and self-fulfillment. In the words of Melvin McLeod “Only when we combine environmentalism with spiritual practice, will we find the tools to make the profound personal transformations needed to address the planetary crisis?”

Keywords: dependent arising, collective ecological suffering, remediation, Buddhist approach

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Authors: Hasan Yalcin, Tugba Dursun Capar

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Deep-fat frying causes desirable as well as undesirable changes in oil and potato, and changes the quality of the oil by hydrolysis, oxidation, and polymerization. The main objective of the present study was to investigate the pre-drying effects on the quality of both frying oil and potatoes. Prior to frying, potato slices (10 mm x10 mm x 30 mm) were air- dried at 60°C for 15, 30, 45, 60, 90, and 120 mins., respectively. Potato slices without the pre-drying treatment were considered as the control variable. Potato slices were fried in sunflower oil at 180°C for 5, 10, and 13 mins. The deep-frying experiments were repeated five times using the new potato slices in the same oil without oil replenishment. Samples of the fresh oil, together with those sampled at the end of successive frying operations (1th, 3th and 5th) were removed and analysed. Moisture content, colour and oil intake of the potato and colour, peroxide value (PV), free fatty acid (FFA), fatty acid composition and viscosity of the used oil were evaluated. The effect of frying time was also examined. Results show that pre-drying treatment had a significant effect on physicochemical properties and colour parameters of potato slices and frying oil. Pre-drying considerably decreased the oil absorption. The lowest oil absorption was found for the treatment that was pre-dried for 120, and fried for 5 min. The FFA levels decreased permanently for each pre-treatment throughout the frying period. All the pre-drying treatments had reached their maximum levels of FFA by the end of the frying procedures. The PV of the control and 60 min pre-dried sample decreased after the third frying. However, the PV of other samples increased constantly throughout the frying periods. Lastly, pre-drying did not affect the fatty acid composition of frying oil considerably when compared against previously unused oil.

Keywords: air-drying, deep-fat frying, moisture content oil uptake, quality

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Authors: Ashok K. Satapathy, Prerana Nashine

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Radiative heat transfer in participating medium was anticipated using the finite volume method. The radiative transfer equations are formulated for absorbing and anisotropically scattering and emitting medium. The solution strategy is discussed and the conditions for computational stability are conferred. The equations have been solved for transient radiative medium and transient radiation incorporated with transient conduction. Results have been obtained for irradiation and corresponding heat fluxes for both the cases. The solutions can be used to conclude incident energy and surface heat flux. Transient solutions were obtained for a slab of heat conducting in slab by thermal radiation. The effect of heat conduction during the transient phase is to partially equalize the internal temperature distribution. The solution procedure provides accurate temperature distributions in these regions. A finite volume procedure with variable space and time increments is used to solve the transient energy equation. The medium in the enclosure absorbs, emits, and anisotropically scatters radiative energy. The incident radiations and the radiative heat fluxes are presented in graphical forms. The phase function anisotropy plays a significant role in the radiation heat transfer when the boundary condition is non-symmetric.

Keywords: participating media, finite volume method, radiation coupled with conduction, heat transfer

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Authors: Salise Oktay, Nilgün Kizilcan, Başak Bengü

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At present, formaldehyde based adhesives such as urea formaldehyde (UF), melamine formaldehyde (MF), melamine – urea formaldehyde (MUF), etc. are mostly used in wood based panel industry because of their high reactivity, chemical versatility, and economic competitiveness. However, formaldehyde based wood adhesives are produced from non- renewable resources. Hence, there has been a growing interest in the development of environment friendly, economically competitive, bio-based wood adhesives in order to meet wood based panel industry requirements. In this study, as formaldehyde free adhesive, Mimosa tannin, starch, sugar based wood adhesivewas synthesized. Citric acid and tartaric acid were used as hardener for the resin system. Solid content, viscosity, and gel time analyzes of the prepared adhesive were performed in order to evaluate the adhesive processability. FTIR characterization technique was used to elucidate the chemical structures of the cured adhesivesamples. In order to evaluate the performance of the prepared bio-based resin formulation, particleboards were produced in a laboratory scale, and mechanical, physical properties of the boards were investigated. Besides, the formaldehyde contents of the boards were determined by using the perforator method. The obtained results revealed that the developed bio-based wood adhesive formulation can be a good potential candidate to use wood based panel industry with some developments.

Keywords: bio-based wood adhesives, mimosa tannin, corn starch, sugar, polycarboxyclic acid

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Authors: Hamesh Babu Nanvala, Madhuri Malhal Rao

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The overall development of the Institution is dependent on the approach and attitude of the principal. Influence of principal’s professionalism on overall development of the Institution is the aim of this paper. Professionalism means conducting oneself with responsibility, integrity, accountability and excellence. The predominant characteristic of professionalism is the temperament of oneself to work in the public interest. By summarizing the observations based on authors’ experience regarding professionalism of principals towards the development of their respective institutions and correlating these observations with the findings in the literature and opinion of other principals and staff, the authors conceived a conceptual approach with its attributes by practicing suggested approach principals that can achieve overall development of their institutions.

Keywords: achiever, development, institution, principal, professionalism, student, teacher

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Authors: Xiang Wang, Yan Pang, Zhaomiao Liu

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Droplet-based microfluidics have been studied extensively with the development of the Micro-Electro-Mechanical System (MEMS) which bears the advantages of high throughput, high efficiency, low cost and low polydispersity. Droplets, worked as versatile carriers, could provide isolated chambers as the internal dispersed phase is protected from the outside continuous phase. Droplets are used to add reagents to start or end bio-chemical reactions, to generate concentration gradients, to realize hydrate crystallization or protein analyses, while droplets coalescence acts as an important control technology. In this paper, deionized water is used as the dispersed phase, and several kinds of oil are used as the continuous phase to investigate the influence of the viscosity ratio of the two phases on the coalescence process. The microchannels are fabricated by coating a polydimethylsiloxane (PDMS) layer onto another PDMS flat plate after corona treatment. All newly made microchannels are rinsed with the continuous oil phase for hours before experiments to ensure the swelling fully developed. High-speed microscope system is used to document the serial videos with a maximum speed of 2000 frames per second. The critical capillary numbers (Ca*) of droplet pairs in various junctions are studied and compared. Ca* varies with different junctions or different liquids within the range of 0.002 to 0.01. However, droplets without extra control would have the problem of synchronism which reduces the coalescence efficiency.

Keywords: coalescence, concentration, critical capillary number, droplet pair, split

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Authors: Vinu Viswanath, Lawrence Dsouza, Ugo Ravon

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Syngas typically and intermediary gas product has a wide range of application of producing various chemical products, such as mixed alcohols, hydrogen, ammonia, Fischer-Tropsch products methanol, ethanol, aldehydes, alcohols, etc. There are several technologies available for the syngas production. An alternative to the conventional processes an attractive route of utilizing carbon dioxide and methane in equimolar ratio to generate syngas of ratio close to one has been developed which is also termed as Dry Reforming of Methane technology. It also gives the privilege to utilize the greenhouse gases like CO2 and CH4. The dry reforming process is highly endothermic, and indeed, ΔG becomes negative if the temperature is higher than 900K and practically, the reaction occurs at 1000-1100K. At this temperature, the sintering of the metal particle is happening that deactivate the catalyst. However, by using this strategy, the methane is just partially oxidized, and some cokes deposition occurs that causing the catalyst deactivation. The current research work was focused to mitigate the main challenges of dry reforming process such coke deposition, and metal sintering at high temperature.To achieve these objectives, we employed three different strategies of catalyst development. 1) Use of bulk catalysts such as olivine and pyrochlore type materials. 2) Use of metal doped support materials, like spinel and clay type material. 3) Use of core-shell model catalyst. In this approach, a thin layer (shell) of redox metal oxide is deposited over the MgAl2O4 /Al2O3 based support material (core). For the core-shell approach, an active metal is been deposited on the surface of the shell. The shell structure formed is a doped metal oxide that can undergo reduction and oxidation reactions (redox), and the core is an alkaline earth aluminate having a high affinity towards carbon dioxide. In the case of metal-doped support catalyst, the enhanced redox properties of doped CeO2 oxide and CO2 affinity property of alkaline earth aluminates collectively helps to overcome coke formation. For all of the mentioned three strategies, a systematic screening of the metals is carried out to optimize the efficiency of the catalyst. To evaluate the performance of them, the activity and stability test were carried out under reaction conditions of temperature ranging from 650 to 850 ̊C and an operating pressure ranging from 1 to 20 bar. The result generated infers that the core-shell model catalyst showed high activity and better stable DR catalysts under atmospheric as well as high-pressure conditions. In this presentation, we will show the results related to the strategy.

Keywords: carbon dioxide, dry reforming, supports, core shell catalyst

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Authors: Gunnar Oskarsson, Gudjon Helgi Egilsson

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Due to globalization, small and medium-sized enterprises (SME) increasingly offer their products and services in foreign markets. The main reasons are either to compensate for a decreased market share in their home market or to exploit opportunities in foreign markets, which are becoming less distant and better accessible than before. International markets are particularly important for companies located in a small economy and offering specialized products. Although more accessible, entering international markets is both expensive and difficult. In order to select the most appropriate markets, it is, therefore, important to gain an insight into the factors that have an impact on success, or potential failure. Although there has been a reasonable volume of research into the theory of internationalization, there is still a need to gain further understanding of the decision-making process of SMEs in small economies and the most important characteristics that distinguish between success and failure. The main objective of this research is to enhance knowledge on the internationalization of SMEs, including the drivers for the decision to internationalize, and the most important factors contributing to success in their internationalization activities. A qualitative approach was found to be most appropriate for this kind of research, with the objective of gaining a deeper understanding and discovering factors which impact a company’s decision-making and potential success. In-depth interviews were conducted with 14 companies in different industries located in Iceland, a country extensively dependent on export revenues. The interviews revealed several factors as drivers of internationalization and, not surprisingly, the most frequently mentioned source of motivation was that the local market is inadequate to maintain a sustainable operation. Good networking relationships were seen as a particular priority for potential success, searching for new markets was mainly carried out through the internet, although sales exhibitions and sales trips were also considered important. When it comes to the final decision as to whether a market should be considered for further analysis, economy, labor cost, legal environment, and cultural barriers were the most common factors to be weighted. The ultimate answer to successful internationalization, however, is largely dependent on a coordinated and experienced management team. The main contribution of this research is offering an insight into factors affecting decision-making in the internationalization process of SMEs, based on the opinion and experience of managers of SMEs in a small economy.

Keywords: internationalization, success factors, small and medium-sized enterprises (SMEs), drivers, decision making

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Authors: L. Kutateldze, T. Urushadze, R. Khvedelidze, N. Zakariashvili, I. Khokhashvili, T. Sadunishvili

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Microbial cellulase/xylanase have shown their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing, and agriculture. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Extremophilic micromycetes and their enzymes that are resistant to critical values of temperature and pH, and retaining enzyme activity for a long time are of great industrial interest. Among strains of microscopic fungi from the collection of S. Durmishidze Institute of Biochemistry and Biotechnology, strains isolated from different ecological niches of Southern Caucasus-active producers of cellulase/xylanase have been selected by means of screening under deep cultivation conditions. Representatives of the genera Aspergillus, Penicillium and Trichoderma are outstanding by relatively high activities of these enzymes. Among the producers were revealed thermophilic strains, representatives of the genus Aspergillus-Aspergillus terreus, Aspergillus versicolor, Aspergillus wentii, also strains of Sporotrichum pulverulentum and Chaetomium thermophile. As a result of optimization of cultivation media and conditions, activities of enzymes produced by the strains have been increased by 4 -189 %. Two strains, active producers of cellulase/xylanase – Penicillium canescence E2 (mesophile) and Aspergillus versicolor Z17 (thermophile) were chosen for further studies. Cellulase/xylanase enzyme preparations from two different genera of microscopic fungi Penicillium canescence E2 and Aspergillus versicolor Z 17 were obtained with activities 220 U/g /1200 U/g and 125 U/g /940 U/g, correspondingly. Main technical characteristics were as follows: the highest enzyme activities were obtained for mesophilic strain Penicillium canescence E2 at 45-500C, while almost the same enzyme activities were fixed for the thermophilic strain Aspergillus versicolor Z 17 at temperature 60-65°C, exceeding the temperature optimum of the mesophile by 150C. Optimum pH of action of the studied cellulase/xylanases from mesophileic and thermophilic strains were similar and equaled to 4.5-5.0 It has been shown that cellulase/xylanase technical preparations from selected strains of Penicillium canescence E2 and Aspergillus versicolor Z17 hydrolyzed cellulose of untreated wheat straw to reducible sugars by 46-52%, and to glucose by 22-27%. However the thermophilic enzyme preparations from the thermophilic A.versicolor strains conducted the process at 600C higher by 100C as compared to mesophlic analogue. Rate of hydrolyses of the pretreated substrate by the same enzyme preparations to reducible sugars and glucose conducted at optimum for their action 60 and 500C was 52-61% and 29-33%, correspondingly. Thus, maximum yield of glucose and reducible sugars form untreated and pretreated wheat straw was achieved at higher temperature (600C) by enzyme preparations from thermophilic strain, which gives advantage for their industrial application.

Keywords: cellulase/xylanase, cellulose hydrolysis, microscopic fungi, thermophilic strain

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Authors: Parag Katira, Frederika Rentzeperis, Zuzanna Nowicka, Giada Fiandaca, Thomas Veith, Jack Farinhas, Noemi Andor

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Resource limitations shape the outcome of competitions between genetically heterogeneous pre-malignant cells. One example of such heterogeneity is in the ploidy (DNA content) of pre-malignant cells. A whole-genome duplication (WGD) transforms a diploid cell into a tetraploid one and has been detected in 28-56% of human cancers. If a tetraploid subclone expands, it consistently does so early in tumor evolution, when cell density is still low, and competition for nutrients is comparatively weak – an observation confirmed for several tumor types. WGD+ cells need more resources to synthesize increasing amounts of DNA, RNA, and proteins. To quantify resource limitations and how they relate to ploidy, we performed a PAN cancer analysis of WGD, PET/CT, and MRI scans. Segmentation of >20 different organs from >900 PET/CT scans were performed with MOOSE. We observed a strong correlation between organ-wide population-average estimates of Oxygen and the average ploidy of cancers growing in the respective organ (Pearson R = 0.66; P= 0.001). In-vitro experiments using near-diploid and near-tetraploid lineages derived from a breast cancer cell line supported the hypothesis that DNA content influences Glucose- and Oxygen-dependent proliferation-, death- and migration rates. To model how subpopulations with variable DNA content compete in the resource-limited environment of the human brain, we developed a stochastic state-space model of the brain (S3MB). The model discretizes the brain into voxels, whereby the state of each voxel is defined by 8+ variables that are updated over time: stiffness, Oxygen, phosphate, glucose, vasculature, dead cells, migrating cells and proliferating cells of various DNA content, and treat conditions such as radiotherapy and chemotherapy. Well-established Fokker-Planck partial differential equations govern the distribution of resources and cells across voxels. We applied S3MB on sequencing and imaging data obtained from a primary GBM patient. We performed whole genome sequencing (WGS) of four surgical specimens collected during the 1ˢᵗ and 2ⁿᵈ surgeries of the GBM and used HATCHET to quantify its clonal composition and how it changes between the two surgeries. HATCHET identified two aneuploid subpopulations of ploidy 1.98 and 2.29, respectively. The low-ploidy clone was dominant at the time of the first surgery and became even more dominant upon recurrence. MRI images were available before and after each surgery and registered to MNI space. The S3MB domain was initiated from 4mm³ voxels of the MNI space. T1 post and T2 flair scan acquired after the 1ˢᵗ surgery informed tumor cell densities per voxel. Magnetic Resonance Elastography scans and PET/CT scans informed stiffness and Glucose access per voxel. We performed a parameter search to recapitulate the GBM’s tumor cell density and ploidy composition before the 2ⁿᵈ surgery. Results suggest that the high-ploidy subpopulation had a higher Glucose-dependent proliferation rate (0.70 vs. 0.49), but a lower Glucose-dependent death rate (0.47 vs. 1.42). These differences resulted in spatial differences in the distribution of the two subpopulations. Our results contribute to a better understanding of how genomics and microenvironments interact to shape cell fate decisions and could help pave the way to therapeutic strategies that mimic prognostically favorable environments.

Keywords: tumor evolution, intra-tumor heterogeneity, whole-genome doubling, mathematical modeling

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Authors: Abasali Masoumi, Amir Gholamian Bozorgi

Abstract:

To have the best quality in wood products such as tabletops and inlay-woods, applying two principles are required: aesthetic and protection against the destructive agent. Artists spent a lot of time creating a masterwork project and also for better demonstrating beautiful appearance and preserving it for hundred years. So they need good material and appropriate method to finish it. As usual, wood painters use polyester or epoxy resins. These finishes need a special skill to use and then give a fantastic paint film and clearness. If we let resins dry in exposure to environmental agents such as unstable temperature, dust and etc., no doubt it becomes cloudy, crack, blister and much wood dust and air bubbles in it. We have designed a special wood coating booth (IR-Patent No: 70429) for wood-coating resins (polyester and epoxy), and this booth provides an adjustable space to control factors that is necessary to have a good finish in the end. Anti-bubble painting booth has the ability to remove bubbles from resin, precludes the cracking process and causes the resin to be the best. With this booth drying time of resin is reduced from 24 hours to 6 hours by fixing the optimum temperature, and it is very good for saving time. This booth is environment-friendly and never lets the poisonous vapors and other VOC (Volatile organic components) enter to workplace atmosphere because they are very harmful to humans.

Keywords: wood coating, epoxy resin, polyester resin, wood finishes

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Authors: Shubham Damke, Md Imtiaz, Sanchita Dei

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To stimulate the well and to enhance the production from the shaly formations, fracturing is essential. Presently the chiefly employed technology is Hydraulic Fracturing. However Hydraulic Fracturing accompanies itself with problems like disposing large volumes of fracturing wastewater, removal of water from the pores, formation damage due to injection of large amount of chemicals into underground formations and many more. Therefore embarking on the path of innovation new techniques have been developed which uses different gases such as Nitrogen, Carbon dioxide, Frac Oil, LPG, etc. are used as a base fluid for fracturing formation. However LPG proves to be the most favorable of them which eliminates the use of water and chemicals. When using it as a fracturing fluid, within the surface equipment, it is stored, gelled, and proppant blended at a constant pressure. It is then pressurized with high pressure pumps to the required surface injection pressure With lowering the total cost and increasing the productivity, LPG is also very noteworthy for fracturing shale, where if the hydraulic fracturing is done the water ‘swells’ the formation and creates surface tension, both of which inhibit the flow of oil and gas. Also fracturing with LPG increases the effective fracture length and since propane, butane and pentane is used which are already present in the natural gas therefore there is no problem of back flow because these gases get mixed with the natural gas. LPG Fracturing technology can be a promising substitute of the Hydraulic Fracturing, which could substantially reduce the capital cost of fracturing shale and will also restrict the problems with the disposal of water and on the same hand increasing the fracture length and the productivity from the shale.

Keywords: Fracking, Shale, Surface Tension, Viscosity

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Authors: Seon Ho Kim, Minho Bang, Seok Min Choi, Young Moon Lee, Dong Kwan Kim, Hyung Hee Cho

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Gas turbines are heat engines that convert chemical energy into electrical energy through mechanical energy. Since their high energy density per unit volume and low pollutant emissions, gas turbines are classified as clean energy. In order to obtain better performance, the turbine inlet temperature of the current gas turbine is operated at about 1600℃, and thermal damage is a very serious problem. Especially, these thermal damages are more prominent in off-design conditions than in design conditions. In this study, the thermal damage characteristics of high temperature components of a gas turbine made of a single crystal material are studied numerically for the off-design operating conditions. The target gas turbine is configured as a reheat cycle and is operated in peak load operation mode, not normal operation. In particular, the target gas turbine features a lot of low-load operation. In this study, a commercial code, ANSYS 18.2, was used for analyzing the thermal-flow coupling problems. As a result, the flow separation phenomenon on the pressure side due to the flow reduction was remarkable at the off-design condition, and the high heat transfer coefficient at the upper end of the suction surface due to the tip leakage flow was appeared.

Keywords: gas turbine, single crystal blade, off-design, thermal analysis

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Authors: Amanda Rithieli Pereira Dos Santos, Rute Quelvia De Faria, Álvaro De Oliveira Cardoso, Anderson Rodrigo Da Silva, Érica Leão Fernandes Araújo

Abstract:

The study of the kinetics of drying has great importance for the mathematical modeling, allowing to know about the processes of transference of heat and mass between the products and to adjust dryers managing new technologies for these processes. The present work had the objective of studying the kinetics of drying of soybean seeds and adjusting different statistical models to the experimental data varying cultivar and temperature. Soybean seeds were pre-dried in a natural environment in order to reduce and homogenize the water content to the level of 14% (b.s.). Then, drying was carried out in a forced air circulation oven at controlled temperatures of 38, 43, 48, 53 and 58 ± 1 ° C, using two soybean cultivars, BRS 8780 and Sambaíba, until reaching a hygroscopic equilibrium. The experimental design was completely randomized in factorial 5 x 2 (temperature x cultivar) with 3 replicates. To the experimental data were adjusted eleven statistical models used to explain the drying process of agricultural products. Regression analysis was performed using the least squares Gauss-Newton algorithm to estimate the parameters. The degree of adjustment was evaluated from the analysis of the coefficient of determination (R²), the adjusted coefficient of determination (R² Aj.) And the standard error (S.E). The models that best represent the drying kinetics of soybean seeds are those of Midilli and Logarítmico.

Keywords: curve of drying seeds, Glycine max L., moisture ratio, statistical models

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Authors: Yeo Kyeong Lee, Ji Yeon Kang, Eun Mi Ryu, Hee Sun Kim, Yeong Soo Shin

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The objective of this paper is an investigation of the effects of the thickness and axial loading during a fire test on the load-bearing capacity of a fire-damaged normal-strength concrete wall. Two factors are attributed to the temperature distributions in the concrete members and are mainly obtained through numerous experiments. Toward this goal, three wall specimens of different thicknesses are heated for 2 h according to the ISO-standard heating curve, and the temperature distributions through the thicknesses are measured using thermocouples. In addition, two wall specimens are heated for 2 h while simultaneously being subjected to a constant axial loading at their top sections. The test results show that the temperature distribution during the fire test depends on wall thickness and axial load during the fire test. After the fire tests, the specimens are cured for one month, followed by the loading testing. The heated specimens are compared with three unheated specimens to investigate the residual load-bearing capacities. The fire-damaged walls show a minor difference of the load-bearing capacity regarding the axial loading, whereas a significant difference became evident regarding the wall thickness. To validate the experiment results, finite element models are generated for which the material properties that are obtained for the experiment are subject to elevated temperatures, and the analytical results show sound agreements with the experiment results. The analytical method based on validated thought experimental results is applied to generate the fire-damaged walls with 2,800 mm high considering the buckling effect: typical story height of residual buildings in Korea. The models for structural analyses generated to deformation shape after thermal analysis. The load-bearing capacity of the fire-damaged walls with pin supports at both ends does not significantly depend on the wall thickness, the reason for it is restraint of pinned ends. The difference of the load-bearing capacity of fire-damaged walls as axial load during the fire is within approximately 5 %.

Keywords: normal-strength concrete wall, wall thickness, axial-load ratio, slenderness ratio, fire test, residual strength, finite element analysis

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Authors: Sender Dovchin, Alastair Pennycook

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This paper looks at the relationship between online space, urban space and digital literacies. The everyday digital literacy practices of Facebook users (with a particular focus on young urban Mongolians) can be understood as ‘metrolingual’ because of the varied ways in which linguistic and cultural resources, spatial repertoires, and online activities are bound together to make meaning. Whereas the initial development of the term metrolingualism was dependent on a notion of physical urban space, we here argue that the digital practices of these Facebook users perform a range of social and cultural identities (sexual, ethnic, and class-based identities) that are both parts of but also adjacent to the metrolingual fabric.

Keywords: metrolingualism, digital literacy, Mongolia, Facebook

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Authors: Eman Ghoneim, Amr S. Fahil

Abstract:

Many regions in Egypt are facing a reduction in crop productivity due to environmental degradation. One factor of crop deterioration includes the unsustainable drainage of surface water, leading to salinized soil conditions. Egypt has exerted time and effort to identify solutions to mitigate the surface water drawdown problem and its resulting effects by exploring renewable and sustainable sources of energy. Siwa Oasis represents one of the most favorable regions in Egypt for geothermal exploitation since it hosts an evident cluster of superficial thermal springs. Some of these hot springs are characterized by high surface temperatures and bottom hole temperatures (BHT) ranging between 20°C to 40 °C and 21 °C to 121.7°C, respectively. The depth to the Precambrian basement rock is commonly greater than 440 m, ranging from 440 m to 4724.4 m. It is this feature that makes the locality of Siwa Oasis sufficient for industrial processes and geothermal power production. In this study, BHT data from 27 deep oil wells were processed by applying the widely used Horner and Gulf of Mexico correction methods to obtain formation temperatures. BHT, commonly used in geothermal studies, remains the most abundant and readily available data source for subsurface temperature information. Outcomes of the present work indicated a geothermal gradient ranging from 18 to 42 °C/km, a heat flow ranging from 24.7 to 111.3 m.W.k⁻¹, and a thermal conductivity of 1.3–2.65 W.m⁻¹.k⁻¹. Remote sensing thermal infrared, topographic, geologic, and geothermal data were utilized to provide geothermal potential maps for the Siwa Oasis. Important physiographic variables (including surface elevation, lineament density, drainage density), geological and geophysical parameters (including land surface temperature, depth to basement, bottom hole temperature, magnetic, geothermal gradient, heat flow, thermal conductivity, and main rock units) were incorporated into GIS to produce a geothermal potential map (GTP) for the Siwa Oasis region. The model revealed that both the northeastern and southeastern sections of the study region are of high geothermal potential. The present work showed that combining bottom-hole temperature measurements and remote sensing data with the selected geospatial methodologies is a useful tool for geothermal prospecting in geologically and tectonically comparable settings in Egypt and East Africa. This work has implications for identifying sustainable resources needed to support food production and renewable energy resources.

Keywords: BHT, geothermal potential map, geothermal gradient, heat flow, thermal conductivity, satellite imagery, GIS

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Authors: Shahbaz Ahmed

Abstract:

This study is conducted to demonstrate the knowledge of intentional learning and incidental learning. Hypothesis of this experiment is intentional learning is better than incidental learning, participants were demonstrated and were asked to learn the 10 nonsense syllables in a specific sequence from the colored cards in the end they were asked to recall the background color of each card instead of nonsense syllables. Independent variables of the experiment are the colored cards containing nonsense syllables which are to be memorized by the participants, dependent variables are the number of correct responses made by the participant. The findings of the experiment concluded that intentional learning is better than incidental learning, hence hypothesis is proved.

Keywords: intentional learning, incidental learning, non-sense syllable cards, score sheets

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Authors: Mustafa M. Bob, Siti Izaidah Azmi, Mohd Hakim Ab Halim, Nur Syahida Abdul Jamal, Aznah Nor-Anuar, Zaini Ujang

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In this research, the formation and development of aerobic granular sludge (AGS) for domestic wastewater treatment application in hot climate conditions was studied using a sequencing batch reactor (SBR). The performance of the developed AGS in the removal of organic matter and nutrients from wastewater was also investigated. The operation of the reactor was based on the sequencing batch system with a complete cycle time of 3 hours that included feeding, aeration, settling, discharging and idling. The reactor was seeded with sludge collected from the municipal wastewater treatment plant in Madinah city, Saudi Arabia and operated at a temperature of 40ºC using synthetic wastewater as influent. Results showed that granular sludge was developed after an operation period of 30 days. The developed granular sludge had a good settling ability with the average size of the granules ranging from 1.03 to 2.42 mm. The removal efficiency of chemical oxygen demand (COD), ammonia nitrogen (NH3-N) and total phosphorus (TP) were 87.31%, 91.93% and 61.25% respectively. These results show that AGS can be developed at elevated temperatures and it is a promising technique to treat domestic wastewater in hot and low humidity climate conditions such as those encountered in Saudi Arabia.

Keywords: aerobic granular sludge, hot climate, sequencing batch reactor, domestic wastewater treatment

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Authors: Eleftheria Barouni, Antonia Terpou, Maria Kanellaki, Argyro Bekatorou, Athanasios A.Koutinas

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The aim of the present work was to evaluate the production of cheese using a composite filter of tubular cellulose (TC) with [a] entrapped rennin enzyme and [b] immobilized L.casei and entrapped enzyme. Tubular cellulose from sawdust was prepared after lignin removal with 1% NaOH. The biocatalysts were thermally dried at 38oC and used for milk coagulation. The effect of temperature (5,20,37 oC) of the first dried biocatalyst on the pH kinetics of milk coagulation was examined. The optimum temperature (37oC) of the first biocatalyst was used for milk coagulation with the second biocatalyst prepared by entrapment of both rennin enzyme and probiotic lactic acid bacteria in order to introduce a sour taste in cheeses. This co-biocatalyst was used for milk coagulation. Samples were studied as regards its effect on lactic acid formation and its correlation with taste test results in cheeses. For both biocatalysts samples were analyzed for total acidity and lactic acid formation by HPLC. The quality of the produced cheeses was examined through the determination of volatile compounds by SPME GC/MS analysis. Preliminary taste tests and microbiological analysis were performed and encourage us for further research regarding scale up.

Keywords: tubular cellulose, Lactobacillus casei, rennin enzyme, cheese production

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Authors: W. Walke, J. Przondziono, K. Nowińska

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The study comprises evaluation of suitability of passive layer created on the surface of AISI 316L stainless steel for products that are intended to have contact with blood. For that purpose, prior to and after chemical passivation, samples were subject to 7 day exposure in artificial plasma at the temperature of T=37°C. Next, tests of metallic ions infiltration from the surface to the solution were performed. The tests were performed with application of spectrometer JY 2000, by Yobin – Yvon, employing Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). In order to characterize physical and chemical features of electrochemical processes taking place during exposure of samples to artificial plasma, tests with application of electrochemical impedance spectroscopy were suggested. The tests were performed with application of measuring unit equipped with potentiostat PGSTAT 302n with an attachment for impedance tests FRA2. Measurements were made in the environment simulating human blood at the temperature of T=37°C. Performed tests proved that application of chemical passivation process for AISI 316L stainless steel used for production of goods intended to have contact with blood is well-grounded and useful in order to improve safety of their usage.

Keywords: AISI 316L stainless steel, chemical passivation, artificial plasma, ions infiltration, EIS

Procedia PDF Downloads 251