Search results for: Vapor Corrosion Inhibitor

Authors: Azhar Jabareen, Mahmoud Huleihel

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BRCA-1 is a multifunctional tumor suppressor, whose expression is activated by the estrogen (E2)-liganded ERα receptor. The activated ERα is a transcriptional factor which activates various genes either by direct binding to the DNA at E2-responsive elements (EREs) and indirectly associated with a range of alternative non-ERE elements. Interference with BRCA-1 expression and/or functions leads to high risk of breast or/and ovarian cancer. Our lab investigated the involvement of Human T-cell leukemia Virus Type 1 (HTLV-1) in breast cancer, since HTLV-1 Tax was found to strongly inhibit BRCA-1 expression. In addition, long exposure of 12-O-tetradecanoylphorbol-13-acetate (TPA), which is one of the stress-inducing agents activated the HTLV-1 promoter. So here the involvement of TPA in breast cancer had been examined by testing the effect of TPA on BRCA-1 and ERE expression. The results showed that TPA activated both BRCA-1 and ERE expression. In the 12 hours TPA activated the tow promoters more than others time, and after 24 hours the level of the tow promoters was decreased. Tax inhibited BRCA-1 expression but did not succeed to inhibit the effect of TPA. Then the activation of the two promoters was not through ERα pathway because TPA had no effect on ERα binding to the two promoters of the BRCA-1 and ERE. Also, the activation was not via nuclear factor kappa B (NF-κB) pathway because when the inhibitory of NF-κB had been added to the TPA, it still activated the tow promoters. However, it seems that 53BP1 may be involved in TPA activation of these promoters because ectopic high expression of 53BP1 significantly reduced the TPA activity. In addition, in the presence of Bisindolylmaleimide-I (BI)- the inhibitor of Protein Kinase C (PKC)- there was no activation for the two promoters, so the PKC is agonized BRCA-1 and ERE activation.

Keywords: BRCA-1, ERE, HTLV-1, TPA

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Authors: D. S. Vardar, A. S. Kipcak, F. T. Senberber, E. M. Derun, S. Piskin, N. Tugrul

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Zinc borate is an important inorganic hydrate borate material, which can be use as a flame retardant agent and corrosion resistance material. This compound can loss its structural water content at higher than 290°C. Due to thermal stability; Zinc Borate can be used as flame reterdant at high temperature process of plastic and gum. In this study, the ultrasonic reaction of zinc borates were studied using hydrozincite (Zn5(CO3)2•(OH)6) and boric acid (H3BO3) raw materials. Before the synthesis raw materials were characterized by X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). Ultrasonic method is a new application on the zinc borate synthesis. The synthesis parameters were set to 90°C reaction temperature and 55 minutes of reaction time, with 1:1, 1:2, 1:3, 1:4 and 1:5 molar ratio of starting materials (Zn5(CO3)2•(OH)6 : H3BO3). After the zinc borate synthesis, the products analyzed by XRD and FT-IR. As a result, optimum molar ratio of 1:5 (Zn5(CO3)2•(OH)6:H3BO3) is determined for the synthesis of zinc borates with ultrasonic method.

Keywords: borate, ultrasonic method, zinc borate, zinc borate synthesis

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Authors: Aseem Rajvanshi, Pankaj Kumar Pandey

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Increase in population has increased the demand of energy to fulfill all its needs. This will result in burden on fossil fuels especially crude oil. Waste oil due to its disposal problem creates environmental degradation. In this context, this paper studies utilization of waste cooking oil and waste motor sludge for making lubricating grease. Experimental studies have been performed by variation in time and concentration of mixture of waste cooking oil and waste motor sludge. The samples were analyzed using penetration test (ASTM D-217), dropping point (ASTM D-566), work penetration (ASTM D-217) and copper strip test (ASTM D-408). Among 6 samples, sample 6 gives the best results with a good drop point and a fine penetration value. The dropping point and penetration test values were found to be 205 °C and 315, respectively. The penetration value falls under the category of NLGI (National Lubricating Grease Institute) consistency number 1.

Keywords: crude oil, copper strip corrosion test, dropping point, penetration test

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Authors: Hong-Jin Joo, Hee-Yoel Kwak

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Vacuum Membrane Distillation (VMD) uses pressure lower than the atmospheric pressure. The feed seawater is capable of producing more vapor at the same temperature than Direct Contact Membrane Distillation (DCMD), Air Gap Membrane Distillation (AGMD) or Sweep Gas Membrane Distillation (SGMD). It is advantageous because it is operable at a lower temperature than other membrane distillations. However, no commercial product is available that uses the VMD method, as it is still in the study stage. In this study, therefore, thermal performance test according to the feed water conditions was performed prior to both construction of the demonstration plant, which uses VMD module of the capacity of 400m³/d in South Korea, and commercialization of VMD module with hollow fiber membrane. Such study was performed by designing and constructing the VMD module of the capacity of 2 m³/day which utilizes the polyvinylidene fluoride (PVDF) hollow fiber membrane. The results obtained from the VMD module manufactured by ECONITY Co., Ltd in South Korea, showed that the maximum performance ratio (PR) value of 0.904, feed water temperature of 75 ℃, and the flow rate of 8 m3/h. As the temperature of and flow rate of the feed water increased, the PR value of the VMD module also increased.

Keywords: membrane distillation, vacuum membrane distillation, hollow fiber membrane, desalination

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Authors: Zahra Tolou-Ghamari

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Introduction: After allogeneic organ transplantation, in order to lower the rate of rejectiontacrolimus is given. In fact, infection is reported as the most complication of tacrolimus that might be associated with higher susceptibility by its’ long term use. Aim: This study aims to review the association between the occurrence of infections after organ transplantation following the administration of tacrolims. Materials and Methods: Scientific literature on the pharmacotherapy of tacrolimus after organ transplantation and infections were searched using PUBMED.Gov (https://pubmed.ncbi.nlm.nih.gov/), Web of Science, and Scopus. Results: In order to prevent acute and chronic rejection, the potent immunosuppressive drug tacrolimus administered as a calcineurin inhibitor after organ transplantation. Its’ most frequent infectious complication is reported as urinary tract infection. Virulent strain of recombinant Literiamonocytogenes, in addition to an increase in bacterial burden in the liver and spleen tissues, was reported in the animal experimental study. The consequence of aggressive events and recipients total area under the cureve exposure to immunosuppressive could be as considered as surrogate markers for individual infection’s risk evaluation. Conclusion: Transplant surgery and duration of hospital stay could determinate the risk of infection during the first month of organ transplantation. Despite administration of antiviral drugs, opportunistic infection such as cytomegalovirus could increase the risk of infection during month 1 to year after transplantation.

Keywords: transplant, infection, tacrolimus, kidney

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Authors: Shiraz A. Markarian

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Our systematic studies of diethylsulfoxide (DESO), the nearest homologue of dimethylsulfoxide (DMSO), reveal new physicochemical features. DESO has already received worthy biomedical applications: in some cases even are more pronounced compare with DMSO. The several important physicochemical characteristics of DESO including aqueous solutions have been verified and first reported: melting point of pure substance, density, dielectric relaxation data, vapor pressure and volumetric properties. Analysis of the complete vibrational spectra also leads to the conclusion that very strong interactions take place between DESO and water, even stronger than those between DMSO and water. The simultaneous existence of strong DESO-H₂O and DESO-DESO interactions suggest the coexistence of many types of structural molecular aggregates, the presence of which plays a significant role also in diluted water solutions. Our recent investigations have shown that aqueous solution of DESO could provide amorphous, glassy systems, thus avoiding ice crystallization, in a wide range of concentrations and even at very low cooling rates. The ability of DESO to act as an effective cryoprotectant on E. coli survival was also studied and compared with other commonly used cryoprotective agents. The results also confirm that DESO, more than DMSO, is able to penetrate living tissues without causing significant damage.

Keywords: diethylsulfoxide, dimethylsulfoxide, cryoprotectant, properties

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Authors: Mohamed A. Deyab, Ahmed E. Awadallah

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Under various conditions, we present a promising method for producing pure hydrogen energy from the electrochemical reaction of Mg metal in waste oilfield water (WOW). Mg metal and WOW are primarily consumed in this process. The results show that the hydrogen gas output is highly dependent on temperature and solution pH. The best conditions for hydrogen production were found to be a low pH (2.5) and a high temperature (338 K). For the first time, the Allyl methylimidazolium bis-trifluoromethyl sulfonyl imide) (IL) ionic liquid is used to regulate the rate of hydrogen generation. It has been confirmed that increasing the solution temperature and decreasing the solution pH accelerates Mg dissolution and produces more hydrogen per unit of time. The adsorption of IL on the active sites of the Mg surface is unrestricted by mixing physical and chemical orientation. Inspections using scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and FT-IR spectroscopy were used to identify and characterise surface corrosion of Mg in WOW. This process is also completely safe and can create energy on demand.

Keywords: hydrogen production, Mg, wastewater, ionic liquid

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Authors: Jean-Francois Feller

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The analysis of the volatolome emitted by the human body with a sensor array (e-nose) is a method for clinical applications full of promises to make an olfactive fingerprint characteristic of people's health state. But the amount of volatile organic compounds (VOC) to detect, being in the range of parts per billion (ppb), and their diversity (several hundred) justifies developing ever more sensitive and selective vapor sensors to improve the discrimination ability of the e-nose, is still of interest. Quantum resistive vapour sensors (vQRS) made with nanostructured conductive polymer nanocomposite transducers have shown a great versatility in both their fabrication and operation to detect volatiles of interest such as cancer biomarkers. However, it has been shown that their chemo-resistive response was highly dependent on the quality of the inter-particular junctions in the percolated architecture. The present work investigates the effectiveness of poly(hedral oligomeric silsesquioxane) acting as a nanospacer to amplify the disconnectability of the conducting network and thus maximize the vQRS's sensitivity to VOC.

Keywords: volatolome, quantum resistive vapour sensor, nanostructured conductive polymer nanocomposites, olfactive diagnosis

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Authors: Faiza Mnasri, Kamilia Abahri, Mohammed El Ganaoui, Slimane Gabsi

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Most of the building materials are considered porous, and composed of solid matrix and pores. In the pores, the moisture can be existed in two phases: liquid and vapor. Thus, the mass balance equation is comprised of various moisture driving potentials that translate the movement of the different existing phases occupying pores and the hygroscopic behavior of a porous construction material. This study suggests to resolve a hygrothermal mathematical model of heat and mass transfers in different porous building materials by a numerical investigation. Thereby, the evolution of temperature and moisture content fields has been processed. So, numerous series of hygrothermal calculation on several cases of wall are exposed. Firstly, a case of monolayer wall of massive wood has been treated. In this part, we have compared the numerical solution of the model on one and two dimensions and the effect of dimensional space has been evaluated. In the second case, three building materials (concrete, wood fiberboard and wooden insulation) are tested separately with the same boundary conditions and their hygrothermal behavior are compared. The evaluation of the exchange of heat and air at the interface between the wall and the interior ambiance is carried.

Keywords: building materials, heat transfer, moisture diffusion, numerical solution

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Authors: Vanessa R. Ralph, Leah J. Scharlott, Megan Y. Deshaye, Ryan L. Stowe

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Given the traditions of chemistry teaching, one may not question whether chemical phenomena play a prominent role. Yet, the role of chemical phenomena in an introductory chemistry course may define the extent to which the course is introductory, chemistry, and equitable. Picture, for example, the classic Ideal Gas Law problem. If one envisions a prompt wherein students are tasked with calculating a missing variable, then one envisions a prompt that relies on chemical phenomena as a context rather than as a model to understand the natural world. Consider a prompt wherein students are tasked with applying molecular models of gases to explain why the vapor pressure of a gaseous solution of water differs from that of carbon dioxide. Here, the chemical phenomenon is not only the context but also the subject of the prompt. Deliveries of general and organic chemistry were identified as ranging wildly in the integration of chemical phenomena. The more incorporated the phenomena, the more equitable the assessment task was for students of varying access to pre-college math and science preparation. How chemical phenomena are integrated may very well define whether courses are chemistry, are introductory, and are equitable. Educators of chemistry are invited colleagues to discuss the role of chemical phenomena in their courses and consider the long-lasting impacts of replicating tradition for tradition’s sake.

Keywords: equitable educational practices, chemistry curriculum, content organization, assessment design

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Authors: Christina Jery, R. K. Anjana, D. N. Arnepalli, R. Sobha

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Modern landfills employ a composite liner consisting of a geomembrane overlying a compacted clay liner (CCL) or a geosynthetic clay liner (GCL) as a barrier system. The primary function of a barrier system is to control the contaminant transport from the leachate (dissolved phase) and landfill gas (vapour phase) out of the landfill thereby minimizing the environmental impact. This study is undertaken to investigate the diffusive migration of VOCs through composite liners. VOCs are known hazardous air pollutants were often existing in both the vapour phase and dissolved phase. These compounds are known to diffuse readily through the polymeric geomembranes. The objective of the research is to develop a comprehensive data set of diffusive parameters involved in the diffusion of VOCs in the composite liner (1.5 mm HDPE geomembrane overlying a 30mm compacted clay layer). For this purpose, the study aims to develop a new experimental setup for determining the diffusion characteristics. The key parameters of diffusion (partitioning, diffusion and permeation coefficients) are examined. The diffusion tests are carried out both in aqueous and vapor phase. Finally, an attempt is also made to study the effect of low temperature on the diffusion characteristics.

Keywords: diffusion, sorption, organic compounds, composite liners, geomembrane

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Authors: Amthal Al-Gailani, Olujide Sanni, Thibaut Charpentier, Anne Neville

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Formation of inorganic scale on heat transfer surfaces is a serious problem encountered in industrial, commercial, and domestic heat exchangers and systems. Several industries use potable/groundwater sources such as rivers, lakes, and oceans to use water as a working fluid in heat exchangers and steamers. As potable/surface water contains diverse salt ionic species, the scaling kinetics and deposit morphology are expected to be different from those found in artificially hardened solutions. In this work, scale formation on the heat transfer surfaces from potable water has been studied using a once-through open flow cell under atmospheric pressure. The surface scaling mechanism and deposit morphology are investigated at high surface temperature. Thus the water evaporation process has to be considered. The effect of surface temperature, flow rate, and inhibitor deployment on the thermal resistance and morphology of the scale have been investigated. The study findings show how an increase in surface temperature enhances the crystallization reaction kinetics on the surface. There is an increase in the amount of scale and the resistance to heat transfer. The fluid flow rate also increases the fouling resistance and the thickness of the scale layer.

Keywords: fouling, heat exchanger, thermal resistance, crystallization, potable water

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Authors: A. Guerrero, A. Leon, S. Munoz, M. Sandoval

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The addition of solvent to cyclic steam stimulation is done in order to reduce the solvent-vapor ratio at late stages of the process, the moment in which this relationship increases significantly. The study of the use of naphtha in addition to the cyclic steam stimulation has been mainly oriented to the effect it achieves on the incremental recovery compared to the application of steam only. However, the effect of naphtha on the reactivity of crude oil components under conditions of cyclic steam stimulation or if its effect is the only dilution has not yet been considered, to author’s best knowledge. The present study aims to evaluate and understand the effect of naphtha and the conditions of cyclic steam stimulation, on the remaining composition of the improved oil, as well as the main mechanisms present in the heavy crude - naphtha interaction. Tests were carried out with the system solvent (naphtha)-oil (12.5° API, 4216 cP @ 40° C)- steam, in a batch micro-reactor, under conditions of cyclic steam stimulation (250-300 °C, 400 psi). The characterization of the samples obtained was carried out by MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) and NMR (Nuclear Magnetic Resonance) techniques. The results indicate that there is a rearrangement of the microstructure of asphaltenes, resulting in a decrease in these and an increase in lighter components such as resins.

Keywords: composition change, cyclic steam stimulation, interaction mechanism, naphtha

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Authors: T. Mahesh, M. K. Samanta

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Antibody dug conjugate (ADC’s) concept is a less explored and more trustable for the treatment of Type 1 diabetes (T1D). T1D is thought to arise from selective immunologically mediated destruction of the insulin- producing β-cells in the pancreatic islets of Langerhans with consequent insulin deficiency. It is evident that type 1 diabetes can be conquered, by 1) to stop immune destruction of βcells, 2) to replace or regenerate β-cells, and 3) to preserve β-cell function and mass. Many studies found that the regulatory T cells (Tregs) are crucial for the maintenance of immunological tolerance. Immune tolerance is liable for the activation of the Th1 response. The important role of Th1 response in pathology of T1D entails the depletion of CD4+ T cells, which initiated the use of anti-CD4 monoclonal antibodies (mAbs) against CD4+ T cells to interfere with induction of T1D.Insulin is regulated by Glucagon-Like Peptide-1 hormone (GLP-1) which also stimulates β-cells proliferation as the half-life of GLP-1 harmone is less due to rapid degradation by DPP-IV enzyme an alternative DPP-IV-inhibitors can increase the half-life of GLP-1 through which it conquers the replacement and reserve β-cells mass. Thus in the present study Anti-CD4 mAb was conjugated with Sitagliptin which is a DPP-IV inhibitor Drug loaded in Nanoparticles through Sulfo-MBS cross-linkers. The above study can be an effective approach for treatment to overcome the Passive subcutaneous insulin therapy.

Keywords: antibody drug conjugates, anti-CD4 Mab, DPP IV inhibitors, GLP-1

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Authors: Ken Ninez Nurpramesti Prinindya, Yuli Setiyorini

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Crown enclosure high temperature flares damaged and reduced dimensions crown. Generally crown on EHTF could have a life time up to twenty years. Therefore, this study aims to increase the value of thermal resistance with the effect post treatment on NiCr coated arc spray method. The variation of post treatment temperature, was at 650°C, 750°C, and 850°C. Morphology on the surface and the adhesion strength was analyzed by SEM-EDX, Surface Roughness and Pull - off test. XRD testing was conducted to determine the contained in NiCr coated. Thermal stability of NiCr coated was tested by DSC-TGA. The most optimal results was owned by NiCr coating with post treated at 850°C. It has good thermal stability until 1000°C because of Cr2O3 formation in coated specimen. The higher temperature of post treatment coating was showed better result on porosity and roughness surface value.

Keywords: Arc spray process, NiCr wire, post-treatment coating, high temperature-corrosion resistance

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

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Aluminum and its alloys are versatile materials which are widely used in industrial and engineering applications due to their good and useful properties e.g. high strength to weight ratio, high thermal and electrical conductivities and good resistance to corrosion. However, against these favorable properties they have the disadvantage they solidifying large grain columnar structure which negatively affects their mechanical properties and surface quality. Aluminum alloys are normally grain refined by some alloying elements, such as Ti, Ti-B or Zr. In this paper, the effect of zirconium addition to Al grain refined by Ti after extrusion on its wear resistance is investigated under different loads and sliding speeds namely at 5,10 and 20 N loads and sliding speeds ranging from m/min. and m/min. the results are presented in three-dimensional wear mode. To the best the authors' knowledge, the wear of aluminum in 3-dimensions has never been tackled before. In this work, the wear resistance of by presenting the results of wear are presented and discussed on the time, load and speed plots.

Keywords: aluminum grain refined, addition of titanium, wear resistance, titanium

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Authors: Marta Malo, Carlota Soto, Carmen García-Rosales, Teresa Hernández

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SiC based composites are candidates for possible use as structural and functional materials in the future fusion reactors, the main role is intended for the blanket modules. In the blanket, the neutrons produced in the fusion reaction slow down and their energy is transformed into heat in order to finally generate electrical power. In the blanket design named Dual Coolant Lead Lithium (DCLL), a PbLi alloy for power conversion and tritium breeding circulates inside hollow channels called Flow Channel Inserts (FCIs). These FCI must protect the steel structures against the highly corrosive PbLi liquid and the high temperatures, but also provide electrical insulation in order to minimize magnetohydrodynamic interactions of the flowing liquid metal with the high magnetic field present in a magnetically confined fusion environment. Due to their nominally high temperature and radiation stability as well as corrosion resistance, SiC is the main choice for the flow channel inserts. The significantly lower manufacturing cost presents porous SiC (dense coating is required in order to assure protection against corrosion and as a tritium barrier) as a firm alternative to SiC/SiC composites for this purpose. This application requires the materials to be exposed to high radiation levels and extreme temperatures, conditions for which previous studies have shown noticeable changes in both the microstructure and the electrical properties of different types of silicon carbide. Both initial properties and radiation/temperature induced damage strongly depend on the crystal structure, polytype, impurities/additives that are determined by the fabrication process, so the development of a suitable material requires full control of these variables. For this work, several SiC samples with different percentage of porosity and sintering additives have been manufactured by the so-called sacrificial template method at the Ceit-IK4 Technology Center (San Sebastián, Spain), and characterized at Ciemat (Madrid, Spain). Electrical conductivity was measured as a function of temperature before and after irradiation with 1.8 MeV electrons in the Ciemat HVEC Van de Graaff accelerator up to 140 MGy (~ 2·10 -5 dpa). Radiation-induced conductivity (RIC) was also examined during irradiation at 550 ºC for different dose rates (from 0.5 to 5 kGy/s). Although no significant RIC was found in general for any of the samples, electrical conductivity increase with irradiation dose was observed to occur for some compositions with a linear tendency. However, first results indicate enhanced radiation resistance for coated samples. Preliminary thermogravimetric tests of selected samples, together with posterior XRD analysis allowed interpret radiation-induced modification of the electrical conductivity in terms of changes in the SiC crystalline structure. Further analysis is needed in order to confirm this.

Keywords: DCLL blanket, electrical conductivity, flow channel insert, porous SiC, radiation damage, thermal stability

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Authors: Feng Xu, Zhaozhi Liu, Junhua Xu, Xiaolong Tang, Dunwen Zuo

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Chemical vapor deposition (CVD) diamond coated cutting tool has excellent cutting performance, it is the most ideal tool for the processing of nonferrous metals and alloys, composites, nonmetallic materials and other difficult-to-machine materials efficiently and accurately. Depositing CVD diamond coating on the cemented carbide with high cobalt content can improve its toughness and strength, therefore, it is very important to research on the preparation technology and cutting properties of CVD diamond coated cemented carbide cutting tool with high cobalt content. The preparation technology of boron-doped diamond (BDD) coating has been studied and the coated drills were prepared. BDD coating were deposited on the drills by using the optimized parameters and the SEM results show that there are no cracks or collapses in the coating. Cutting tests with the prepared drills against the silumin and aluminum base printed circuit board (PCB) have been studied. The results show that the wear amount of the coated drill is small and the machined surface has a better precision. The coating does not come off during the test, which shows good adhesion and cutting performance of the drill.

Keywords: cemented carbide with high cobalt content, CVD boron-doped diamond, cutting test, drill

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Authors: Ritesh Joshi, Kishan Fuse, Gopal Zinzala, Nishit Nirmal

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Ti-6Al-4V is a titanium alloy having high strength, low weight and corrosion resistant which is a required characteristic for a material to be used in aerospace industry. Titanium, being a hard alloy is difficult to the machine via conventional methods, so it is a call to use non-conventional processes. In present work, the effects on Ti-6Al-4V by drilling a hole of Ø 6 mm using copper (99%) electrode in Electric Discharge Machining (EDM) process is analyzed. Effect of various input parameters like peak current, pulse-on time and pulse-off time on output parameters viz material removal rate (MRR) and electrode wear rate (EWR) is studied. Multi-objective optimization technique Grey relational analysis is used for process optimization. Experiments are designed using an L9 orthogonal array. ANOVA is used for finding most contributing parameter followed by confirmation tests for validating the results. Improvement of 7.45% in gray relational grade is observed.

Keywords: ANOVA, electric discharge machining, grey relational analysis, Ti-6Al-4V

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Authors: Ilma Robo, Saimir Heta, Edona Hasanaj, Vera Ostreni

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The hybrid layer, the way it is created and how it is protected against degradation over time, is the key to the clinical success of a composite restoration. The composite supports the dentinal structure exactly with the realized surface of microretension. Thus, this surface is in direct proportion to its size versus the duration of clinical use of composite dental restoration. Micro-retention occurs between dentin or acidified enamel and adhesive resin extensions versus pre-prepared spaces, such as hollow dentinal tubules. The way the adhesive resin binds to the acidified dentinal structure depends on the physical or chemical factors of this interrelationship between two structures with very different characteristics. During the acidification process, a precursor to the placement of the adhesive resin layer, activation of metaloproteinases of dental origin occurs, enzymes which are responsible for the degradation of the hybrid layer. These enzymes have expressed activity depending on the presence of Zn2 + or Ca2 + ions. There are several ways to inhibit these enzymes, and consequently, there are several ways to inhibit the degradation process of the hybrid layer. The study aims to evaluate chlorhexidine as a solution element, inhibitor of dentin activated metalloproteinases, as a result of the application of acidification. This study aims to look at this solution in advantage or contraindication theories, already published in the literature.

Keywords: hybrid layer, chlorhexidine, degradation, application

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Authors: Silviya Todorova, Anton Naydenov, Ralitsa Velinova, Alexander Larin

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Catalytic combustion of methane has been extensively investigated for emission control and power generation during the last decades. The alumina-supported palladium catalyst is widely accepted as the most active catalysts for catalytic combustion of methane. The activity of Pd/Al₂O₃ decreases during the time on stream, especially underwater vapor. The following order of activity in the reaction of complete oxidation of methane was established: Co₃O₄> CuO>NiO> Mn₂O₃> Cr₂O₃. It may be expected that the combination between Pd and these oxides could lead to the promising catalysts in the reaction of complete methane. In the present work, we investigate the activity of Pd/Al₂O₃ catalysts promoted with other metal oxides (MOx; M= Ni, Co, Ce). The Pd-based catalysts modified by metal oxide were prepared by sequential impregnation of Al₂O₃ with aqueous solutions of Me(NO₃)₂.6H₂O and Pd(NO₃)₂H₂O. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). An improvement of activity was observed after modification with different oxides. The results demonstrate that the Pd/Al₂O₃ catalysts modified with Co and Ce by impregnation with a common solution of respective salts, exhibit the most promising catalytic activity for methane oxidation. Most probably, the presence of Co₃O₄ and CeO₂ on catalytic surface increases surface oxygen and therefore leads to the better reactivity in methane combustion.

Keywords: methane combustion, palladium, Co-Ce, Ni-Ce

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Authors: Dalia Jomehpour, Sara Sheikhlary, Esmaeil Heydari, Mohammad Hossien Majles Ara

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In this study, we report fulvic acid-coated iron oxide nanoparticles of 10.7 ± 2.7 nm size, which serve to inhibit amyloid fibrillation formation. Although the effect of fulvic acid on tau fibrils was investigated, to our best knowledge, its inhibitory impacts on amyloid aggregation formation have been assessed neither in-vitro nor in-vivo. On the other hand, iron oxide nanoparticles exhibit anti-amyloid activity on their own. This study investigates the inhibitory effect of fulvic acid coated iron oxide nanoparticles on amyloid aggregations formed from the commonly used in-vitro model, lysozyme from chicken egg white. FESEM, XRD, and FTIR characterization confirmed that fulvic acid was coated onto the surface of the nanoparticles. The inhibitory effects of the fulvic acid coated iron oxide nanoparticles were verified by Thioflavin T assay, circular dichroism (CD), and FESEM analysis. Furthermore, the toxicity of the nanoparticles on the neuroblastoma SH-SY5Y human cell line was assessed through an MTT assay. Our results indicate that fulvic acid coated iron oxide nanoparticles can efficiently inhibit the formation of amyloid aggregations while exhibiting negligible in-vitro toxicity; thus, they can be used as anti-amyloid agents in the development of the potential drug for neurodegenerative diseases.

Keywords: Alzheimer’s disease, fulvic acid coated iron oxide nanoparticles, fulvic acid, amyloid inhibitor, polyphenols

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Authors: Parthiban S. R.

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Spiral heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. An innovative spiral heat exchanger based on polymer materials is designed for waste heat recovery process. Such a design based on polymer film technology provides better corrosion and chemical resistance compared to conventional metal heat exchangers. Due to the smooth surface of polymer film fouling is reduced. A new arrangement for flow of hot flue gas and cold fluid is employed for design, flue gas flows in axial path while the cold fluid flows in a spiral path. Heat load recovery achieved with the presented heat exchanger is in the range of 1.5 kW thermic but potential heat recovery about 3.5 kW might be achievable. To measure the performance of the spiral tube heat exchanger, its model is suitably designed and fabricated so as to perform experimental tests. The paper gives analysis of spiral tube heat exchanger.

Keywords: spiral heat exchanger, polymer based materials, fouling factor, heat load

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Authors: Kourosh Kosari

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This study is engineering the properties of concrete containing natural nano zeolite as supplementary cementitious material in the blended Portland-cement based binder in amounts of 5,7 and 10% by mass. Crashing of clinoptilolite zeolite is performed by means of planetary ball mill. Two types of concrete along with water to cementitious material ratio (W/(C + P)) in 0.45 and 0.4 at the ages of 7, 28 and 90 days and were compared with each other. The effect of these additives on mechanical properties (compressive and tensile strength) and durability has been investigated by Electrical Resistivity (ER) and Rapid Chloride Penetration Test (RCPT) at the ages 28 and 90 days. Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) revealed that nanoparticles of natural clinoptilolite could improve quality of concrete. As a result of the tests, decrease in penetration of chloride ion and increase electrical resistivity significantly that are appropriate option for controlling of corrosion in reinforced concrete structures but increase of mechanical characteristics is not considerable.

Keywords: ball mill, durability, mechanical properties, nano zeolite

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Authors: Ibrahim Musa, Guy Raffin, Marie Hangouet, Nadia Zine, Nicole Jaffrezic-Renault, Abdelhamid Errachid

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Due to its application in different domains, such as fuel cell configuration and adulteration of alcoholic beverages, a miniaturized sensor for methanol detection is urgently required. A conductometric microsensor for measuring volatile organic compounds (VOC) was conceived, based on electrospun composite nanofibers of polyvinyl chloride (PVC) doped with nickel phthalocyanine(NiPc) deposited on interdigitated electrodes (IDEs) used transducers. The nanofiber's shape, structure, percent atomic content and thermal properties were studied using analytical techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), respectively. The methanol sensor showed good sensitivity (505µS/cm(v/v) ⁻¹), low LOD (15 ppm), short response time (13 s), and short recovery time (15 s). The sensor was 4 times more sensitive to methanol than to ethanol and 19 times more sensitive to methanol than to acetone. Furthermore, the sensor response was unaffected by the interfering water vapor, making it more suitable for VOC sensing in the presence of humidity. The sensor was applied for conductometric detection of methanol in rubbing alcohol.

Keywords: composite, methanol, conductometric sensor, electrospun, nanofiber, nickel phthalocyanine, PVC

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Authors: Naif Al-Jomah, Falah H Al-Mohanna, Abdelilah Aboussekhra

Abstract:

Active breast cancer-associated fibroblasts (CAFs), the most influential cells in breast tumor microenvironment, express/secrete high levels of the proinvasive/metastatic interleukin-6 (IL-6). Therefore, we have tested here the effect of the IL-6 receptor (IL-6R) inhibitor tocilizumab (TCZ; Actemra) on different active breast CAFs. We have shown that TCZ potently and persistently suppresses the expression of various CAF biomarkers, namely α-SMA, SDF-1 as well as the STAT3 pathway and its downstream target AUF1. TCZ also inhibited the proliferation, migration and invasion abilities of active breast CAF cells. Additionally, TCZ repressed the ability of CAF cells in promoting epithelial-to-mesenchymal transition, and enhancing the migratory/invasive and proliferative capacities of breast cancer cells in vitro. Importantly, these findings were confirmed in orthotopic humanized breast tumors in mice. Furthermore, TCZ suppressed the expression of the pro-angiogenic factor VEGF-A and its transactivator HIF-1α in CAF cells, and consequently inhibited the angiogenic-promoting effect of active CAFs both in vitro and in orthotopic tumor xenografts. These results indicate that inhibition of the IL-6/STAT3/AUF1 pathway by TCZ can normalize active breast CAFs and suppress their paracrine pro-carcinogenic effects, which paves the way toward development of specific CAF-targeting therapy, badly needed for more efficient breast cancer treatments.

Keywords: angiogenesis, interleukin-6, paracrine, cancer-associated fibroblasts

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Authors: Zhongyang Sun, Shu Zhang, Manjiang Xie

Abstract:

Emerging evidence indicates that microRNAs (miRNAs) play important roles in modulating osteoblast function and bone formation. However, the influence of miRNA on osteoblast proliferation and the possible mechanisms underlying remain to be defined. In this study, we aimed to investigate whether miR-103 regulates osteoblast proliferation under simulated microgravity condition through regulating Cav1.2, the primary subunit of L-type voltage sensitive calcium channels (LTCCs). We first investigated the effect of simulated microgravity on osteoblast proliferation and the outcomes clearly demonstrated that the mechanical unloading inhibits MC3T3-E1 osteoblast-like cells proliferation. Using quantitative Real-Time PCR (qRT-PCR), we provided data showing that miR-103 was up-regulated in response to simulated microgravity. In addition, we observed that up-regulation of miR-103 inhibited and down-regulation of miR-103 promoted osteoblast proliferation under simulated microgravity condition. Furthermore, knocking-down or over-expressing miR-103, respectively, up- or down-regulated the level of Cav1.2 expression and LTCCs currents, suggesting that miR-103 acts as an endogenous attenuator of Cav1.2 in osteoblasts under the condition of simulated microgravity. More importantly, we showed that the effect of miR-103 on osteoblast proliferation was diminished in simulated microgravity, when co-transfecting miR-103 mimic or inhibitor with Cav1.2 siRNA. Taken together, our data suggest that miR-103 inhibits osteoblast proliferation mainly through suppression of Cav1.2 expression under simulated microgravity condition. This work may provide a novel mechanism of microgravity-induced detrimental effects on osteoblast, identifying miR-103 as a novel possible therapeutic target in bone remodeling disorders in this mechanical unloading.

Keywords: microRNA, osteoblasts, cell proliferation, Cav1.2, simulated microgravity

Procedia PDF Downloads 366

Authors: Alaa A. Ghanem, S. E. M. Desouky

Abstract:

Natural gas (NG) is considered one of the most essential global energy sources. NG fields are often far away from the market, and a long-distance transporting pipeline usually is required. Production of NG with high content of CO₂ leads to severe problems such as equipment corrosion along with the production line until refinery.in addition to a high level of toxicity and decreasing in calorific value of the NG. So it is recommended to remove or decrease the CO₂ percent to meet transport specifications. This can be reached using different removal techniques such as physical and chemical absorption, pressure swing adsorption, membrane separation, or low-temperature separation. Many solvents and chemicals are being used to capture carbon dioxide on a large scale; among them, Ionic liquids have great potential due to their tunable properties; low vapour pressure, low melting point, and sensible thermal stability. In this research, three modifiedimidazolium ionic liquids will be synthesized and characterized using different tools of analysis such as FT-IR, 1H NMR. Thermal stability and surface activity will be studied. The synthesized compounds will be evaluated as selective solvents for CO₂ removal from natural gas using PVT cell.

Keywords: natural gas, CO₂ capture, imidazolium ionic liquid, PVT cell

Procedia PDF Downloads 175

Authors: Y. S. Mohamed, L. A. Ahmed, H. A. Salem, A. M. Agha

Abstract:

Liver Fibrosis is one of the most serious conditions that affect the Egyptian society. In the present study, the effect of nicorandil was investigated in experimentally-induced liver fibrosis by bile duct ligation in rats. Nicorandil (3mg/kg/day) was given orally 24 h after bile duct ligation for 14 days till the end of the experiment. Nicorandil group showed a significant improvement in liver function tests (ALT and ALP) as well as a significant decrease in oxidative stress biomarkers (TBARS and GSH), area of fibrosis and activity of hepatic stellate cells as indicated by decreased expression of alpha smooth muscle actin.Moreover, nicorandil treatment decreased HSCs proliferation due to its inhibitory effects on protein kinase C(PKC) and Platelet derived growth factor (PDGF) . Oral administration of either glibenclamide (10 mg/kg/day)(a KATP channel blocker) or L-NAME (30 mg/kg/day) (an inhibitor of nitric oxide synthase) blocked the protective effects of nicorandil. However, nicorandil and L-NAME treated group showed more or less results similar to that of untreated bile duct ligated group. In conclusion, nicorandil was effective against the development of bile duct ligated-induced liver fibrosis in rats where activation of the NO pathway plays an important role in the protective effect nicorandil.

Keywords: hepatic stellate cells, nicorandil, nitric oxide donor, liver fibrosis

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Authors: S. Yakut, D. Deger, K. Ulutas, D. Bozoglu

Abstract:

Plasma poly(ethylene oxide) (pPEO) thin films were deposited between Aluminum (Al) electrodes on glass substrates by plasma assisted physical vapor deposition (PAPVD). The deposition was operated inside Argon plasma under 10⁻³ Torr and the thicknesses of samples were determined as 20, 100, 250, 500 nm. The plasma was produced at 5 W by magnetron connected to RF power supply. The capacitance C and dielectric loss factor tan δ were measured by Novovontrol Alpha-A high frequency empedance analyzer at freqquency and temperature intervals of 0,1 Hz and 1MHz, 193-353K, respectively. AC conductivity was derived from these values. AC conductivity results exhibited three different conductivity regions except for 20 nm. These regions can be classified as low, mid and high frequency regions. Low frequency region is observed at around 10 Hz and 300 K while mid frequency region is observed at around 1 kHz and 300 K. The last one, high frequency region, is observed at around 1 kHz and 200 K. There are some coinciding definitions for conduction regions, because these regions shift depending on temperature. Low frequency region behaves as DC-like conductivity while mid and high frequency regions show conductivities corresponding to mechanisms such as classical hopping, tunneling, etc. which are observed for amorphous materials. Unlike other thicknesses, for 20 nm sample low frequency region can not be detected in the investigated freuency range. It is thought that this is arised because of the presence of dead layer behavior.

Keywords: plasma polymers, dead layer, dielectric spectroscopy, AC conductivity

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