Search results for: heat strain
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4486

Search results for: heat strain

1606 Effect of Transition Metal Addition on Aging Behavior of Invar Alloy

Authors: Young Sik Kim, Tae Kwon Ha

Abstract:

High strength Fe-36Ni-base Invar alloys containing Al contents up to 0.3 weight per cent were cast into ingots and thermodynamic equilibrium during solidification has been investigated in this study. From the thermodynamic simulation using Thermo-Calc®, it has been revealed that equilibrium phases which can be formed are two kinds of MC-type precipitates, MoC, and M2C carbides. The mu phase was also expected to form by addition of aluminum. Microstructure observation revealed the coarse precipitates in the as-cast ingots, which was non-equilibrium phase and could be resolved by the successive heat treatment. With increasing Al contents up to 0.3 wt.%, tensile strength of Invar alloy increased as 1400MPa after cold rolling and thermal expansion coefficient increased significantly. Cold rolling appeared to dramatically decrease thermal expansion coefficient.

Keywords: Invar alloy, transition metals, phase equilibrium, aging behavior, microstructure, hardness

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1605 Conversion of Glycerol to 3-Hydroxypropanoic Acid by Genetically Engineered Bacillus subtilis

Authors: Aida Kalantari, Boyang Ji, Tao Chen, Ivan Mijakovic

Abstract:

3-hydroxypropanoic acid (3-HP) is one of the most important biomass-derivable platform chemicals that can be converted into a number of industrially important compounds. There have been several attempts at production of 3-HP from renewable sources in cell factories, focusing mainly on Escherichia coli, Klebsiella pneumoniae, and Saccharomyces cerevisiae. Despite the significant progress made in this field, commercially exploitable large-scale production of 3-HP in microbial strains has still not been achieved. In this study, we investigated the potential of Bacillus subtilis to be used as a microbial platform for bioconversion of glycerol into 3-HP. Our recombinant B. subtilis strains overexpress the two-step heterologous pathway containing glycerol dehydratase and aldehyde dehydrogenase from various backgrounds. The recombinant strains harboring the codon-optimized synthetic pathway from K. pneumoniae produced low levels of 3-HP. Since the enzymes in the heterologous pathway are sensitive to oxygen, we had to perform our experiments in micro-aerobic conditions. Under these conditions, the cell produces lactate in order to regenerate NAD+, and we found the lactate production to be in competition with the production of 3-HP. Therefore, based on the in silico predictions, we knocked out the glycerol kinase (glpk), which in combination with growth on glucose, resulted in improving the 3-HP titer to 1 g/L and the removal of lactate. Cultivation of the same strain in an enriched medium improved the 3-HP titer up to 7.6 g/L. Our findings provide the first report of successful introduction of the biosynthetic pathway for conversion of glycerol into 3-HP in B. subtilis.

Keywords: bacillus subtilis, glycerol, 3-hydroxypropanoic acid, metabolic engineering

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1604 Finite Element Analysis and Design Optimization of Stent and Balloon System

Authors: V. Hashim, P. N. Dileep

Abstract:

Stent implantation is being seen as the most successful method to treat coronary artery diseases. Different types of stents are available in the market these days and the success of a stent implantation greatly depends on the proper selection of a suitable stent for a patient. Computer numerical simulation is the cost effective way to choose the compatible stent. Studies confirm that the design characteristics of stent do have great importance with regards to the pressure it can sustain, the maximum displacement it can produce, the developed stress concentration and so on. In this paper different designs of stent were analyzed together with balloon to optimize the stent and balloon system. Commercially available stent Palmaz-Schatz has been selected for analysis. Abaqus software is used to simulate the system. This work is the finite element analysis of the artery stent implant to find out the design factors affecting the stress and strain. The work consists of two phases. In the first phase, stress distribution of three models were compared - stent without balloon, stent with balloon of equal length and stent with balloon of extra length than stent. In second phase, three different design models of Palmaz-Schatz stent were compared by keeping the balloon length constant. The results obtained from analysis shows that, the design of the strut have strong effect on the stress distribution. A design with chamfered slots found better results. The length of the balloon also has influence on stress concentration of the stent. Increase in length of the balloon will reduce stress, but will increase dog boning effect.

Keywords: coronary stent, finite element analysis, restenosis, stress concentration

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1603 A Novel PfkB Gene Cloning and Characterization for Expression in Potato Plants

Authors: Arfan Ali, Idrees Ahmad Nasir

Abstract:

Potato (Solanum tuberosum) is an important cash crop and popular vegetable in Pakistan and throughout the world. Cold storage of potatoes accelerates the conversion of starch into reduced sugars (glucose and fructose). This process causes dry mass and bitter taste in the potatoes that are not acceptable to end consumers. In the current study, the phosphofructokinase B gene was cloned into the pET-30 vector for protein expression and the pCambia-1301 vector for plant expression. Amplification of a 930bp product from an E. coli strain determined the successful isolation of the phosphofructokinase B gene. Restriction digestion using NcoI and BglII along with the amplification of the 930bp product using gene specific primers confirmed the successful cloning of the PfkB gene in both vectors. The protein was expressed as a His-PfkB fusion protein. Western blot analysis confirmed the presence of the 35 Kda PfkB protein when hybridized with anti-His antibodies. The construct Fani-01 was evaluated transiently using a histochemical gus assay. The appearance of blue color in the agroinfiltrated area of potato leaves confirmed the successful expression of construct Fani-01. Further, the area displaying gus expression was evaluated for PfkB expression using ELISA. Moreover, PfkB gene expression evaluated through transient expression determined successful gene expression and highlighted its potential utilization for stable expression in potato to reduce sweetening due to long-term storage.

Keywords: potato, Solanum tuberosum, transformation, PfkB, anti-sweetening

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1602 SiC Particulate-Reinforced SiC Composites Fabricated by PIP Method Using Highly Concentrated SiC Slurry

Authors: Jian Gu, Sea-Hoon Lee, Jun-Seop Kim

Abstract:

SiC particulate-reinforced SiC ceramic composites (SiCp/SiC) were successfully fabricated using polymer impregnation and pyrolysis (PIP) method. The effects of green density, infiltrated method, pyrolytic temperature, and heating rate on the densification behavior of the composites were investigated. SiCp/SiC particulate reinforced composites with high relative density up to 88.06% were fabricated after 4 PIP cycles using SiC pellets with high green density. The pellets were prepared by drying 62-70 vol.% aqueous SiC slurries, and the maximum relative density of the pellets was 75.5%. The hardness of the as-fabricated SiCp/SiCs was 21.05 GPa after 4 PIP cycles, which value increased to 23.99 GPa after a heat treatment at 2000℃. Excellent mechanical properties, thermal stability, and short processing time render the SiCp/SiC composite as a challenging candidate for the high-temperature application.

Keywords: high green density, mechanical property, polymer impregnation and pyrolysis, structural application

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1601 Development and Sound Absorption and Insulation Performance Evaluation of Nonwoven Fabric Material including Paper Honeycomb Structure for Insulator Covering Shelf Trim

Authors: In-Sung Lee, Un-Hwan Park, Jun-Hyeok Heo, Dae-Gyu Park

Abstract:

Insulator Covering Shelf Trim is one of the automotive interior parts located in the rear seat of a car, and it is a component that is the most strongly demanded for impact resistance, strength, and heat resistance. Such an Insulator Covering Shelf Trim is composed of a polyethylene terephthalate (PET) nonwoven fabric which is a surface material appearing externally and a substrate layer which exerts shape and mechanical strength. In this paper, we develop a lightweight Insulator Covering Shelf Trim using the nonwoven fabric material with a high strength honeycomb structure and evaluate sound absorption and insulation performance by using acoustic impedance tubes.

Keywords: sound absorption and insulation, insulator covering shelf trim, nonwoven fabric, honeycomb

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1600 Strength of Fine Concrete Used in Textile Reinforced Concrete by Changing Water-Binder Ratio

Authors: Taekyun Kim, Jongho Park, Jinwoong Choi, Sun-Kyu Park

Abstract:

Recently, the abnormal climate phenomenon has enlarged due to the global warming. As a result, temperature variation is increasing and the term is being prolonged, frequency of high and low temperature is increasing by heat wave and severe cold. Especially for reinforced concrete structure, the corrosion of reinforcement has occurred by concrete crack due to temperature change and the durability of the structure that has decreased by concrete crack. Accordingly, the textile reinforced concrete (TRC) which does not corrode due to using textile is getting the interest and the investigation of TRC is proceeding. The study of TRC structure behavior has proceeded, but the characteristic study of the concrete used in TRC is insufficient. Therefore, characteristic of the concrete by changing mixing ratio is studied in this paper. As a result, mixing ratio with different water-binder ratio has influenced to the strength of concrete. Also, as the water-binder ratio has decreased, strength of concrete has increased.

Keywords: concrete, mixing ratio, textile, TRC

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1599 Thermal Energy Storage Based on Molten Salts Containing Nano-Particles: Dispersion Stability and Thermal Conductivity Using Multi-Scale Computational Modelling

Authors: Bashar Mahmoud, Lee Mortimer, Michael Fairweather

Abstract:

New methods have recently been introduced to improve the thermal property values of molten nitrate salts (a binary mixture of NaNO3:KNO3in 60:40 wt. %), by doping them with minute concentration of nanoparticles in the range of 0.5 to 1.5 wt. % to form the so-called: Nano-heat-transfer-fluid, apt for thermal energy transfer and storage applications. The present study aims to assess the stability of these nanofluids using the advanced computational modelling technique, Lagrangian particle tracking. A multi-phase solid-liquid model is used, where the motion of embedded nanoparticles in the suspended fluid is treated by an Euler-Lagrange hybrid scheme with fixed time stepping. This technique enables measurements of various multi-scale forces whose characteristic (length and timescales) are quite different. Two systems are considered, both consisting of 50 nm Al2O3 ceramic nanoparticles suspended in fluids of different density ratios. This includes both water (5 to 95 °C) and molten nitrate salt (220 to 500 °C) at various volume fractions ranging between 1% to 5%. Dynamic properties of both phases are coupled to the ambient temperature of the fluid suspension. The three-dimensional computational region consists of a 1μm cube and particles are homogeneously distributed across the domain. Periodic boundary conditions are enforced. The particle equations of motion are integrated using the fourth order Runge-Kutta algorithm with a very small time-step, Δts, set at 10-11 s. The implemented technique demonstrates the key dynamics of aggregated nanoparticles and this involves: Brownian motion, soft-sphere particle-particle collisions, and Derjaguin, Landau, Vervey, and Overbeek (DLVO) forces. These mechanisms are responsible for the predictive model of aggregation of nano-suspensions. An energy transport-based method of predicting the thermal conductivity of the nanofluids is also used to determine thermal properties of the suspension. The simulation results confirms the effectiveness of the technique. The values are in excellent agreement with the theoretical and experimental data obtained from similar studies. The predictions indicates the role of Brownian motion and DLVO force (represented by both the repulsive electric double layer and an attractive Van der Waals) and its influence in the level of nanoparticles agglomeration. As to the nano-aggregates formed that was found to play a key role in governing the thermal behavior of nanofluids at various particle concentration. The presentation will include a quantitative assessment of these forces and mechanisms, which would lead to conclusions about nanofluids, heat transfer performance and thermal characteristics and its potential application in solar thermal energy plants.

Keywords: thermal energy storage, molten salt, nano-fluids, multi-scale computational modelling

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1598 Determination of the Bearing Capacity of Granular Pumice Soils by Laboratory Tests

Authors: Mustafa Yildiz, Ali Sinan Soganci

Abstract:

Pumice soils are countered in many projects such as transportation roads, channels and residential units throughout the World. The pumice deposits are characterized by the vesicular nature of their particles. When the pumice soils are evaluated considering the geotechnical viewpoint, they differ from silica sands in terms of physical and engineering characteristics. These differences are low grain strength, high friction angle, void ratio and compressibility. At stresses greater than a few hundred kPa, the stress-strain-strength behaviour of these soils is determined by particle crushing. Particle crushing leads to changes in the density and reduction in the components of shear stress due to expansion. In this study, the bearing capacity and behaviour of granular pumice soils compared to sand-gravels were investigated by laboratory model tests. Firstly the geotechnical properties of granular pumice soils were determined; then, the behaviour of pumice soils with an equivalent diameter of sand and gravel soils were investigated by model rectangular and circular foundation types and were compared with each other. For this purpose, basic types of model footing (15*15 cm, 20*20 cm, Φ=15 cm and Φ=20 cm) have been selected. When the experimental results of model bearing capacity are analyzed, the values of sand and gravel bearing capacity tests were found to be 1.0-1.5 times higher than the bearing capacity of pumice the same size. This fact has shown that sand and gravel have a higher bearing capacity than pumice of the similar particle sizes.

Keywords: pumice soils, laboratory model tests, bearing capacity, laboratory model tests, Nevşehir

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1597 On the Exergy Analysis of the Aluminum Smelter

Authors: Ayoola T. Brimmo, Mohamed I. Hassan

Abstract:

The push to mitigate the aluminum smelting industry’s enormous energy consumption and high emission releases is now even more persistent with the recent climate change happenings. Common approaches to achieve this have been focused on improving energy efficiency in the pot line and cast house sections of the smelter. However, the conventional energy efficiency analyses are based on the first law of thermodynamics, which do not shed proper light on the smelter’s degradation of energy. This just gives a general idea of the furnace’s performance with no reference to locations where improvement is a possibility based on the second law of thermodynamics. In this study, we apply exergy analyses on the pot line and cast house sections of the smelter to identify the locality and causes of energy degradation. The exergy analyses, which are based on a real life smelter conditions, highlight the possible locations for technology improvement in a typical smelter. With this established, methods of minimizing the smelter’s exergy losses are assessed.

Keywords: exergy analysis, electrolytic cell, furnace, heat transfer

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1596 After-Cooling Analysis of RC Structural Members Exposed to High Temperature by Using Numerical Approach

Authors: Ju-Young Hwang, Hyo-Gyoung Kwak

Abstract:

This paper introduces a numerical analysis method for reinforced-concrete (RC) structures exposed to fire and compares the result with experimental results. The proposed analysis method for RC structure under the high temperature consists of two procedures. First step is to decide the temperature distribution across the section through the heat transfer analysis by using the time-temperature curve. After determination of the temperature distribution, the nonlinear analysis is followed. By considering material and geometrical nonlinearity with the temperature distribution, nonlinear analysis predicts the behavior of RC structure under the fire by the exposed time. The proposed method is validated by the comparison with the experimental results. Finally, prediction model to describe the status of after-cooling concrete can also be introduced based on the results of additional experiment. The product of this study is expected to be embedded for smart structure monitoring system against fire in u-City.

Keywords: RC, high temperature, after-cooling analysis, nonlinear analysis

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1595 Identification of Two Novel Carbapenemase Gene Variants from a Carbapenem-Resistant Aeromonas Veronii Environmental Isolate

Authors: Rafael Estrada, Cristian Ruiz Rueda

Abstract:

Carbapenems are last-resort antibiotics used in clinical settings to treat antibiotic-resistant bacterial infections. Thus, the emergence and spread of resistance to carbapenems is a major public health concern. Here, we have studied a carbapenem-resistant Aeromonas veronii strain previously isolated from a water sample from Sam Simeon Creek (Hearst San Simeon State Park, CA). Analysis of this isolate using disk-diffusion, CarbaNP, eCIM and mCIM assays revealed that it was resistant to amoxicillin-clavulanic acid and all carbapenems tested and that this isolate produced a potentially novel carbapenemase of the Metallo-β-lactamase family. Whole genome sequencing analysis revealed that this A. veronii isolate carries a novel variant of the blacₚₕₐ class β-carbapenemase gene that was closely related to the blacₚₕₐ₇ gene of Aeromonas jandaei. This isolate also carried a novel variant of the blaₒₓₐ class D carbapenemase gene that was most closely related to the blaₒₓₐ-₉₁₂ gene found in other Aeromonas veronii isolates. Finally, we also identified a novel class C β-lactamase gene moderately related to the blaFₒₓ-₁₇ gene of Providencia stuartii and other blaFₒₓ variants identified in Klebsiella pneumoniae, Escherichia coli and other Enterobacteriaceae. Overall, our findings reveal that environmental isolates are an important reservoir of multiple carbapenemases and other β-lactamases of clinical significance.

Keywords: β-lactamases, carbapenem, antibiotic-resistant, aeromonas veronii

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1594 The Optimisation of Salt Impregnated Matrices as Potential Thermochemical Storage Materials

Authors: Robert J. Sutton, Jon Elvins, Sean Casey, Eifion Jewell, Justin R. Searle

Abstract:

Thermochemical storage utilises chemical salts which store and release energy a fully reversible endo/exothermic chemical reaction. Highly porous vermiculite impregnated with CaCl2, LiNO3 and MgSO4 (SIMs – Salt In Matrices) are proposed as potential materials for long-term thermochemical storage. The behavior of these materials during typical hydration and dehydration cycles is investigated. A simple moisture experiment represents the hydration, whilst thermogravimetric analysis (TGA) represents the dehydration. Further experiments to approximate the energy density and to determine the peak output temperatures of the SIMs are conducted. The CaCl2 SIM is deemed the best performing SIM across most experiments, whilst the results of MgSO4 SIM indicate difficulty associated with energy recovery.

Keywords: hydrated states, inter-seasonal heat storage, moisture sorption, salt in matrix

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1593 Surpassing Antibiotic Resistance through Synergistic Effects of Polyethyleneimine-Silver Nanoparticle Complex Coated Mesoporous Silica Trio-Nanoconstructs

Authors: Ranjith Kumar Kankala, Wei-Zhi Lin, Chia-Hung Lee

Abstract:

Antibiotic resistance in bacteria has become an emergency situation clinically. To improve the efficacy of antibiotics in resistant strains, advancement of nanoparticles is inevitable than ever. Herewith, we demonstrate a design by immobilizing tetracycline (TET) in copper substituted mesoporous silica nanoparticles (Cu-MSNs) through a pH-sensitive coordination link, enabling its release in the acidic environment. Subsequently, MSNs are coated with silver nanoparticles stabilized polyethyleneimine (PEI-SNP) to act against drug-resistant (MDR) bacterial strains. Silver ions released from SNP are capable of sensitizing the resistant strains and facilitate the generation of free radicals capable of damaging the cell components. In addition, copper ions in the framework are also capable of generating free radicals through Fenton-like reaction. Furthermore, the nanoparticles are well-characterized physically, and various antibacterial efficacious tests against isolated multidrug resistant bacterial strain were highly commendable. However, this formulation has no significant toxic effect on normal mammalian fibroblast cells accounting its high biocompatibility. These MSN trio-hybrids, i.e., SNP, tetracycline, and copper ions result in synergistic effects, and their advancement could bypass resistance and allow synergism for effective treatment of antibiotic clinically.

Keywords: antibiotic resistance, copper, mesoporous silica nanoparticles, Ph-sensitive release, polyethyleneimine, silver, tetracycline

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1592 Thermal and Flammability Properties of Paraffin/Nanoclay Composite Phase Change Materials Incorporated in Building Materials for Thermal Energy Storage

Authors: Awni H. Alkhazaleh, Baljinder K. Kandola

Abstract:

In this study, a form-stable composite Paraffin/Nanoclay (PA-NC) has been prepared by absorbing PA into porous particles of NC to be used for low-temperature latent heat thermal energy storage. The leakage test shows that the maximum mass fraction of PA that can be incorporated in NC without leakage is 60 wt.%. Differential scanning calorimetry (DSC) has been used to measure the thermal properties of the PA and PA-NC both before and after incorporation in plasterboard (PL). The mechanical performance of the samples has been evaluated in flexural mode. The thermal energy storage performance has been studied using a small test chamber (100 mm × 100 mm × 100 mm) made from 10 mm thick PL and measuring the temperatures using thermocouples. The flammability of the PL+PL-NC has been discussed using a cone calorimeter. The results indicate that the form composite PA has good potential for use as thermal energy storage materials in building applications.

Keywords: building materials, flammability, phase change materials, thermal energy storage

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1591 Effect of Molybdenum Addition to Aluminum Grain Refined by Titanium Plus Boron on Its Grain Size and Mechanical Characteristics in the Cast and After Pressing by the Equal Channel Angular Pressing Conditions

Authors: A. I. O. Zaid, A. M. Attieh, S. M. A. Al Qawabah

Abstract:

Aluminum and its alloys solidify in columnar structure with large grain size which tends to reduce their mechanical strength and surface quality. They are, therefore, grain refined by addition of either titanium or titanium plus boron to their melt before solidification. Equal channel angular pressing, ECAP, process is a recent forming method for producing heavy plastic deformation in materials. In this paper, the effect of molybdenum addition to aluminum grain refined by Ti+B on its metallurgical and mechanical characteristics are investigated in the as cast condition and after pressing by the ECAP process. It was found that addition of Mo or Ti+B alone or together to aluminum resulted in grain refining of its microstructure in the as cast condition, as the average grain size was reduced from 139 micron to 46 micron when Mo and Ti+B are added together. Pressing by the ECAP process resulted in further refinement of the microstructure where 32 micron of average grain size was achieved in Al and the Al-Mo microalloy. Regarding the mechanical strength, addition of Mo or Ti+B alone to Al resulted in deterioration of its mechanical behavior but resulted in enhancement of its mechanical behavior when added together, increase of 10% in flow stress was achieved at 20% strain. However, pressing by ECAP addition of Mo or Ti+B alone to Al resulted in enhancement of its mechanical strength but reduced its strength when added together.

Keywords: ECAP, aluminum, cast, mechanical characteristics, Mo grain refiner

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1590 Production of Buttermilk as a Bio-Active Functional Food by Utilizing Dairy Waste

Authors: Hafsa Tahir, Sanaullah Iqbal

Abstract:

Glactooligosaccharide (GOS) is a type of prebiotic which is mainly found in human milk. GOS belongs to those bacteria which stimulates the growth of beneficial bacteria in human intestines. The aim of the present study was to develop a value-added product by producing prebiotic (GOS) in buttermilk through trans galactosylation. Buttermilk is considered as an industrial waste which is discarded after the production of butter and cream. It contains protein, minerals, vitamins and a smaller amount of fat. Raw milk was pasteurized at 100º C for butter production and then trans galactosylation process was induced in the butter milk thus obtained to produce prebiotic GOS. Results showed that the enzyme (which was obtained from bacterial strain of Esecrshia coli and has a gene of Lactobacillus reuteri L103) concentration between 400-600µl/5ml can produce GOS in 30 minutes. Chemical analysis and sensory evaluation of plain and GOS containing buttermilk showed no remarkable difference in their composition. Furthermore, the shelf-life study showed that there was non-significant (P>0.05) difference in glass and pouch packaging of buttermilk. Buttermilk in pouch packaging maintained its stability for 6 days without the addition of preservatives. Therefore it is recommended that GOS enriched buttermilk which is generally considered as a processing waste in dairy manufacturing can be turned into a cost-effective nutritional functional food product. This will not only enhance the production efficiency of butter processing but also will create a new market opportunity for dairy manufacturers all over the world.

Keywords: buttermilk, galactooligosaccharide, shelf Life, transgalactosylation

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1589 Study on NOₓ Emission Characteristics of Internal Gas Recirculation Technique

Authors: DaeHae Kim, MinJun Kwon, Sewon Kim

Abstract:

This study is aimed to develop ultra-low NOₓ burner using the internal recirculation of flue gas inside the combustion chamber that utilizes the momentum of intake fuel and air. Detailed experimental investigations are carried out to study these fluid dynamic effects on the emission characteristics of newly developed burner in industrial steam boiler system. Experimental parameters are distance of Venturi tube from burner, Coanda nozzle gap distance, and air sleeve length at various fuel/air ratio and thermal heat load conditions. The results showed that NOₓ concentration decreases as the distance of Venturi tube from burner increases. The CO concentration values at all operating conditions were negligible. In addition, the increase of the Coanda nozzle gap distance decreased the NOₓ concentration. It is experimentally found out that both fuel injection recirculation and air injection recirculation technique was very effective in reducing NOₓ formation.

Keywords: Coanda effect, combustion, burner, low NOₓ

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1588 Voxel Models as Input for Heat Transfer Simulations with Siemens NX Based on X-Ray Microtomography Images of Random Fibre Reinforced Composites

Authors: Steven Latré, Frederik Desplentere, Ilya Straumit, Stepan V. Lomov

Abstract:

A method is proposed in order to create a three-dimensional finite element model representing fibre reinforced insulation materials for the simulation software Siemens NX. VoxTex software, a tool for quantification of µCT images of fibrous materials, is used for the transformation of microtomography images of random fibre reinforced composites into finite element models. An automatic tool was developed to execute the import of the models to the thermal solver module of Siemens NX. The paper describes the numerical tools used for the image quantification and the transformation and illustrates them on several thermal simulations of fibre reinforced insulation blankets filled with low thermal conductive fillers. The calculation of thermal conductivity is validated by comparison with the experimental data.

Keywords: analysis, modelling, thermal, voxel

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1587 The Mechanical Behavior of a Cement-Fiber Composite Material

Authors: K. Harrat, M. Hidjeb, M. T’kint

Abstract:

The aim of the present research work is to characterize a cement palm date fiber composite in order to be used in isolation and in the manufacture of new structural materials. This technique may possibly participate seriously in the preservation of the environment and develop a growing need for plant products. On one hand, It has been shown that the presence of natural fiber in the composite materials manufacture, based on hydraulic binder, has improved the mechanical behaviour of the material. On the Other hand, It has been proven that the durability of composite materials reinforced with untreated fibers was largely affected by the presence of organic matter. In order to extract the organic material, the fibers were treated with boiling water and then coated with different types of products. A considerable improvement in the sensitivity to water of the fibers, as well as in the mechanical strength and in the ductility of the composite material was observed. The fiber being sensitive to water, the study put the emphasis on its dimensional stability.

Keywords: cement composite, durability, heat treatment, mechanical behaviour, vegetal fiber

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1586 Antioxidant Activity of Chlorophyll from Sauropus androgynus Leaves in Female Mice Induced Sodium Nitrite

Authors: Suparmi, Sampurna

Abstract:

Sodium nitrite which is widespread used as a color fixative and preservative in foods can increase oxidative stress and cause hemolytic anemia. Consumption of food supplement containing sufficient antioxidant, e.g. chlorophyll, reported can decrease these negative effects. This study was conducted to determine the effect of chlorophyll from Sauropus androgynus leaves on Malodialdehide (MDA) and ferritin level. Experimental research with post-test only control group design was conducted using 24 female mice strain Balb-c. Sodium nitrite 0.3 ml/head/day given during 18 days, while the chlorophyll or Cu-chlorophyllin as much as 0.7 ml/head/day given the following day for 14 days. The mean of MDA levels of blood plasma in the control group, NaNO2 induction, induction NaNO2 and chlorophyll of S. androgynus leaves, induction of NaNO2 and Cu-chlorophyllin from K-Liquid in sequence is 2.10±0.11mol/L, 3.44±0.38 mol/L, 2.31±0.18 mol/L, 2.31±0.13 mol/L, whilst the ferritin levels mean in each group is 62.71±6.42 ng/ml; 63.22±7.59 ng/ml; 67.45±8.03 ng/ml, and 64.74±7.80 ng/ml, respectively. Results of Mann Whitney test found no significant difference in MDA levels (p>0.05), while the One-Way Anova test result found no significant difference in ferritin levels between the groups of mice that received S. androgynus chlorophyll with a group of mice that received Cu-chlorophyllin after induction NaNO2 (p>0.05). This indicates that chlorophyll from S. androgynus leaves as effective as Cu-chlorophyllin in decrease of MDA levels and increase of ferritin levels. Chlorophyll from S. androgynus are potential as food supplement in anemic conditions caused by sodium nitrite consumptions.

Keywords: ferritin, MDA, chlorophyll, sodium nitrite

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1585 Paenibacillus illinoisensis CX11: A Cellulase- and Xylanase-Producing Bacteria for Saccharification of Lignocellulosic Materials

Authors: Abeer A. Q. Ahmed, Tracey McKay

Abstract:

Biomass can provide a sustainable source for the production of high valued chemicals. Under the uncertain availability of fossil resources biomass could be the only available source for chemicals in future. Cellulose and hemicellulose can be hydrolyzed into their building blocks (hexsoses and pentoses) which can be converted later to the desired high valued chemicals. A cellulase- and xylanase- producing bacterial strain identified as Paenibacillus illinoisensis CX11 by 16S rRNA gene sequencing and phylogenetic analysis was found to have the ability to saccharify different lignocellulosic materials. Cellulase and xylanase activities were evaluated by 3,5-dinitro-salicylic acid (DNS) method using CMC and xylan as substrates. Results showed that P. illinoisensis CX11 have cellulase (2.63± 0.09 mg/ml) and xylanase (3.25 ± 0.2 mg/ml) activities. The ability of P. illinoisensis CX11 to saccharify lignocellulosic materials was tested using wheat straw (WS), wheat bran (WB), saw dust (SD), and corn stover (CS). DNS method was used to determine the amount of reducing sugars that were released from lignocellulosic materials. P. illinoisensis CX11 showed to have the ability to saccharify lignocellulosic materials and producing total reducing sugars as 2.34 ± 0.12, 2.51 ± 0.37, 1.86 ± 0.16, and 3.29 ± 0.20 mg/l from WS, WB, SD, and CS respectively. According to the author's knowledge, current findings are the first to report P. illinoisensis CX11 as a cellulase and xylanase producing species and that it has the ability to saccharify different lignocellulosic materials. This study presents P. illinoisensis CX11 that can be good source for cellulase and xylanase enzymes which could be introduced into lignocellulose bioconversion processes to produce high valued chemicals.

Keywords: cellulase, high valued chemicals, lignocellulosic materials, Paenibacillus illinoisensis CX11, Xylanase

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1584 Extracellular Phytase from Lactobacillus fermentum spp KA1: Optimization of Enzyme Production and Its Application for Improving the Nutritional Quality of Rice Bran

Authors: Neha Sharma, Kanthi K. Kondepudi, Naveen Gupta

Abstract:

Phytases are phytate specific phosphatases catalyzing the step-wise dephosphorylation of phytate, which acts as an anti-nutritional factor in food due to its strong binding capacity to minerals. In recent years microbial phytases have been explored for improving nutritional quality of food. But the major limitation is acceptability of phytases from these microorganisms. Therefore, efforts are being made to isolate organisms which are generally regarded as safe for human consumption such as Lactic Acid Bacteria (LAB). Phytases from these organisms will have an edge over other phytase sources due to its probiotic attributes. Only few LAB have been reported to give phytase activity that too is generally seen as intracellular. LAB producing extracellular phytase will be more useful as it can degrade phytate more effectively. Moreover, enzyme from such isolate will have application in food processing also. Only few species of Lactobacillus producing extracellular phytase have been reported so far. This study reports the isolation of a probiotic strain of Lactobacillus fermentum spp KA1 which produces extracellular phytase. Conditions for the optimal production of phytase have been optimized and the enzyme production resulted in an approximately 13-fold increase in yield. The phytate degradation potential of extracellular phytase in rice bran has been explored and conditions for optimal degradation were optimized. Under optimal conditions, there was 43.26% release of inorganic phosphate and 6.45% decrease of phytate content.

Keywords: Lactobacillus, phytase, phytate reduction, rice bran

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1583 Comparison Physicochemical Properties of Hexane Extracted Aniseed Oil from Cold Press Extraction Residue and Cold Press Aniseed Oil

Authors: Derya Ören, Şeyma Akalın

Abstract:

Cold pres technique is a traditional method to obtain oil. The cold-pressing procedure, involves neither heat nor chemical treatments, so cold press technique has low oil yield and cold pressed herbal material residue still contains some oil. In this study, the oil that is remained in the cold pressed aniseed extracted with hegzan and analysed to determine physicochemical properties and quality parameters. It is found that the aniseed after cold press process contains % 10 oil. Other analysis parametres free fatty acid (FFA) is 2,1 mgKOH/g, peroxide value is 7,6 meq02/kg. Cold pressed aniseed oil values are determined for fatty acid (FFA) value as 2,1 mgKOH/g, peroxide value 4,5 meq02/kg respectively. Also fatty acid composition is analysed, it is found that both of these oil have same fatty acid composition. The main fatty acids are; oleic, linoleic, and palmitic acids.

Keywords: aniseed oil, cold press, extraction, residue

Procedia PDF Downloads 377
1582 Assessment of Fluid Flow Hydrodynamics for Cylindrical and Conical Fluidized Bed Reactor

Authors: N. G. Thangan, A. B. Deoghare, P. M. Padole

Abstract:

Computational Fluid Dynamics (CFD) aids in modeling the prototype of a real world processes. CFD approach is useful in predicting the fluid flow, heat transfer mass transfer and other flow related phenomenon. In present study, hydrodynamic characteristics of gas-solid cylindrical fluidized bed is compared with conical fluidized beds. A 2D fluidized bed consists of different configurations of particle size of iron oxide, bed height and superficial velocities of nitrogen. Simulations are performed to capture the complex physics associated with it. The Eulerian multiphase model is prepared in ANSYS FLUENT v.14 which is used to simulate fluidization process. It is analyzed with nitrogen as primary phase and iron oxide as secondary phase. The bed hydrodynamics is assessed prominently to examine effect on fluidization time, pressure drop, minimum fluidization velocity, and gas holdup in the system.

Keywords: fluidized bed, bed hydrodynamics, Eulerian multiphase approach, computational fluid dynamics

Procedia PDF Downloads 439
1581 Engoglaze Development for the Production of Glazed Porcelain Tiles

Authors: Sezgi Isik, Yasin Urersoy, Gizem Ustunel, Ilkyaz Yalcin

Abstract:

Improvement of the digital tile application, lots of process revolutions have occurred in the tile production. In order to create unique and inimitable designs, all the competitors start to try different applications. Both Europian and domestic ceramic producers focus on the deep and realistic surfaces. In this study, the trend of engoglaze, which is becoming widespread in glaze porcelain tile designs to create the most intensive colours, were investigated. The aim of the study is to develop engoglaze formulation that supports digital ink activation. Thermal expansion coefficient values were determined by a dilatometer. Chemical analyses and sintering behaviors of engoglazes were made by X-ray diffraction and heat microscopy analysis. According to these glaze formulation studies, it has been reported that using engoglaze could easily reduce the digital ink consumption of the design. On the other hand, the advantage of the production cost is gained, and deepness of the design is provided.

Keywords: ceramic, engoglaze, digital ink activation, glazed porcelain tile

Procedia PDF Downloads 121
1580 A Review on the Use of Salt in Building Construction

Authors: Vesna Pungercar, Florian Musso

Abstract:

Identifying materials that can substitute rare or expensive natural resources is one of the key challenges for improving resource efficiency in the building sector. With a growing world population and rising living standards, more and more salt is produced as waste through seawater desalination and potash mining processes. Unfortunately, most of the salt is directly disposed of into nature, where it causes environmental pollution. On the other hand, salt is affordable, is used therapeutically in various respiratory treatments, and can store humidity and heat. It was, therefore, necessary to determine salt materials already in use in building construction and their hygrothermal properties. This research aims to identify salt materials from different scientific branches and historically, to investigate their properties and prioritize the most promising salt materials for indoor applications in a thermal envelope. This was realized through literature review and classification of salt materials into three groups (raw salt materials, composite salt materials, and processed salt materials). The outcome of this research shows that salt has already been used as a building material for centuries and has a potential for future applications due to its hygrothermal properties in a thermal envelope.

Keywords: salt, building material, hygrothermal properties, environment

Procedia PDF Downloads 155
1579 Laser Welding of Titanium Alloy Ti64 to Polyamide 6.6: Effects of Welding Parameters on Temperature Profile Evolution

Authors: A. Al-Sayyad, P. Lama, J. Bardon, P. Hirchenhahn, L. Houssiau, P. Plapper

Abstract:

Composite metal–polymer materials, in particular titanium alloy (Ti-6Al-4V) to polyamide (PA6.6), fabricated by laser joining, have gained cogent interest among industries and researchers concerned with aerospace and biomedical applications. This work adopts infrared (IR) thermography technique to investigate effects of laser parameters used in the welding process on the three-dimensional temperature profile at the rear-side of titanium, at the region to be welded with polyamide. Cross sectional analysis of welded joints showed correlations between the morphology of titanium and polyamide at the weld zone with the corresponding temperature profile. In particular, spatial temperature profile was found to be correlated with the laser beam energy density, titanium molten pool width and depth, and polyamide heat affected zone depth.

Keywords: laser welding, metals to polymers joining, process monitoring, temperature profile, thermography

Procedia PDF Downloads 125
1578 High Piezoelectric and Magnetic Performance Achieved in the Lead-free BiFeO3-BaTiO3 Cceramics by Defect Engineering

Authors: Muhammad Habib, Xuefan Zhou, Lin Tang, Guoliang Xue, Fazli Akram, Dou Zhang

Abstract:

Defect engineering approach is a well-established approach for the customization of functional properties of perovskite ceramics. In modern technology, the high multiferroic properties for elevated temperature applications are greatly demanding. In this work, the Bi-nonstoichiometric lead-free 0.67Biy-xSmxFeO3-0.33BaTiO3 ceramics (Sm-doped BF-BT for Bi-excess; y = 1.03 and Bi-deficient; y = 0.975 with x = 0.00, 0.04 and 0.08) were design for the high-temperature multiferroic property. Enhanced piezoelectric (d33  250 pC/N and d33* 350 pm/V) and magnetic properties (Mr  0.25 emu/g) with a high Curie temperature (TC  465 ℃) were obtained in the Bi-deficient pure BF-BT ceramics. With Sm-doping (x = 0.04), the TC decrease to 350 ℃ a significant improvement occurred in the d33* to 504 pm/V and 450 pm/V for Bi-excess and Bi-deficient compositions, respectively. The structural origin of the enhanced piezoelectric strain performance is related to the soft ferroelectric effect by Sm-doping and reversible phase transition from the short-range relaxor ferroelectric state to the long-range order under the applied electric field. However, a slight change occurs in the Mr 0.28 emu/g value with Sm-doping for Bi-deficient ceramics, whereas the Bi-excess ceramics shows completely paramagnetic behavior. Hence, the origin of high magnetic properties in the Bi-deficient BF-BT ceramics is mainly attributed to the proposed double exchange mechanism. We believe that this strategy will provide a new perspective for the development of lead-free multiferroic ceramics for high-temperature applications.

Keywords: BiFeO3-BaTiO3, lead-free piezoceramics, magnetic properties, defect engineering

Procedia PDF Downloads 120
1577 Anti Staphylococcus aureus and Methicillin Resistant Staphylococcus aureus Action of Thermophilic Fungi Acrophialophora levis IBSD19 and Determination of Its Mode of Action Using Electron Microscopy

Authors: Shivankar Agrawal, Indira Sarangthem

Abstract:

Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA) remains one of the major causes of healthcare-associated and community-onset infections worldwide. Hence the search for non-toxic natural compounds having antibacterial activity has intensified for future drug development. The exploration of less studied niches of Earth can highly increase the possibility to discover novel bioactive compounds. Therefore, in this study, the cultivable fraction of fungi from the sediments of natural hot springs has been studied to mine potential fungal candidates with antibacterial activity against the human pathogen Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus. We isolated diverse strains of thermophilic fungi from a collection of samples from sediment. Following a standard method, we isolated a promising thermophilic fungus strain IBSD19, identified as Acrophialophora levis, possessing the potential to produce an anti-Staphylococcus aureus agent. The growth conditions were optimized and scaled to fermentation, and its produced extract was subjected to chemical extraction. The ethyl acetate fraction was found to display significant activity against Staphylococcus aureus and MRSA with a minimum inhibitory concentration (MIC) of 0.5 mg/ml and 4 mg/ml, respectively. The cell membrane integrity assay and SEM suggested that the fungal metabolites cause bacteria clustering and further lysis of the cell.

Keywords: antibacterial activity, antioxidant, fungi, Staphylococcus aureus, MRSA, thermophiles

Procedia PDF Downloads 125