Search results for: ethanol vapor

Authors: Lucia Gharwalova, Irena Kolouchova, Jan Masak

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A large amount of waste products is generated throughout the whole winemaking process as well as during work in the vineyard. This waste is as a source of phenolic compounds, such as resveratrol and polydatin, which possess a strong antioxidant capacity. Changes in the amounts of phenols were compared depending on the growing conditions and wine variety. Wastes (grape stems, marc and shoots) from two wineries in the Czech Republic were analyzed. Phenols from these samples were extracted by 40% ethanol. The amount of polyphenols in these extracts was determined by HPLC and their antioxidant capacity by DPPH. We compared changes in the amounts of phenols depending on the type of waste and the wine variety. The most significant source of stilbenoids was waste from pruning (shoots). These results show that winery waste could be further reused thanks to their antioxidant content.

Keywords: antioxidants, polyphenols, resveratrol, winery waste

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Authors: Wanting Zeng, Hsunling Bai

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Silica was extracted from agriculture waste rice husk ash (RHA) and was used as the silica source for synthesis of RMCM-48 and RSBA-16. An alkali fusion process was utilized to separate silicate supernatant and the sediment effectively. The CTAB/Si and F127/Si molar ratio was employed to control the structure properties of the obtained RMCM-48 and RSBA-16 materials. The N2 adsorption-desorption results showed the micro-mesoporous RSBA-16 possessed high specific surface areas (662-1001 m2/g). All the obtained RSBA-16 materials were applied as the adsorbents for acetone adsorption. And the breakthrough tests clearly revealed that the RSBA-16(0.004) materials could achieve the highest acetone adsorption capacity of 186 mg/g under 1000 ppmv acetone vapor concentration at 25oC, which was also superior to ZSM-5 (71mg/g) and MCM-41 (157mg/g) under same test conditions. This can help to reduce the solid waste and the high adsorption performance of the obtained materials could consider as potential adsorbents for acetone adsorption.

Keywords: acetone, adsorption, micro-mesoporous material, rice husk ash (RHA), RSBA-16

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Authors: Sperisa Distantina, Fadilah Fadilah, Mujtahid Kaavessina

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Hydrogel films were prepared from kappa carrageenan by crosslinking with glutaraldehyde. Carrageenan films extracted from Kappaphycus alvarezii seaweed were immersed in glutaraldehyde solution for 2 min and then cured at 110 °C for 25 min. The obtained crosslinked films were washed with ethanol to remove the unreacted glutaraldehyde and then air dried to constant weights. The aim of this research was to study the swelling degree behaviour of the hydrogel film to neutral salts solution, namely NaCl, KCl, and CaCl₂. The results showed that swelling degree of crosslinked films varied non-monotonically with salinity of NaCl. Swelling degree decreased with the increasing of KCl concentration. Swelling degree of crosslinked film in CaCl₂ solution was lower than that in NaCl and in KCl solutions.

Keywords: carrageenan, hydrogel, glutaraldehyde, salt, swelling

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Authors: Yasin Akgul, Fazil Husem, Memis Isik

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In this study, effect of content of chromium (III) oxide on production of Al/Cr203 alloys were investigated. Experimental procedure was started with mixturing of powders in the presence of absolute ethanol, vacuum distillation technique was used for evaporation, by ultrasonic bath and mechanic stirrer. Pressing procedure was achieved by hydrolic press that has 100 tons forcing for production of 25 mm diameter compact green billets. Green bodies were sintered at 600 °C in argon atmosphere. Scanning electron microscope (SEM) analysis for characterization of microstructure, compression test for determination of strength and Vickers test for measuring of hardness of sintered billets were done. End of the study is concluded that, enhancement of physical and mechanical properties is observed by increasing content of chromium (III) oxide.

Keywords: aluminium, chromium (III) oxide, powder metallurgy, sintering

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Authors: Gulshan Sachdeva, Vaibhav Jain, S. S. Kachhwaha

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Cascade refrigeration systems employ series of single stage vapor compression units which are thermally coupled with evaporator/condenser cascades. Different refrigerants are used in each of the circuit depending on the optimum characteristics shown by the refrigerant for a particular application. In the present research study, a steady state thermodynamic model is developed which simulates the working of an actual cascade system. The model provides COP and all other system parameters like total compressor work, temperature, pressure, enthalpy and entropy at different state points. The working fluid in Low Temperature Circuit (LTC) is CO2 (R744) while ammonia (R717), propane (R290), propylene (R1270), R404A and R12 are the refrigerants in High Temperature Circuit (HTC). The performance curves of ammonia, propane, propylene, and R404A are compared with R12 to find its nearest substitute. Results show that ammonia is the best substitute of R12.

Keywords: cascade system, refrigerants, thermodynamic model, production engineering

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Authors: Hyung T. Kwak, Jun Gao, Yao An, Alfred Kleinhammes, Yue Wu

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Surface wettability is a crucial factor in oil recovery. In oil industry, the rock wettability involves the interplay between water, oil, and solid surface. Therefore, studying the interplay between adsorptions of water and hydrocarbon molecules on solid surface would be very informative for understanding rock wettability. Here we use the in-situ Nuclear Magnetic Resonance (NMR) gas isotherm technique to study competitive adsorptions of water and isopropanol, an intermediate step from hydrocarbons. This in-situ NMR technique obtains information on thermodynamic properties such as the isotherm, molecular dynamics via spin relaxation measurements, and adsorption kinetics such as how fast the system can reach thermal equilibrium after changes of vapor pressures. Using surfaces of silica glass beads, which can be modified from hydrophilic to hydrophobic, we obtained information on the influence of surface hydrophilicity on the state of surface water via obtained thermodynamic and dynamic properties.

Keywords: Wettability, NMR, Gas Isotherm, Hydrophilicity, adsorption

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Authors: Rouzbeh Ramezani, Renzo Di Felice

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Nowadays, removal of CO₂ as one of the major contributors to global warming using alternative solvents with high CO₂ absorption efficiency, is an important industrial operation. In this study, three amines, including 2-methylpiperazine, potassium sarcosinate and potassium lysinate as potential additives, were added to the potassium carbonate solution as a base solvent for CO₂ capture. In order to study the absorption performance of CO₂ in terms of loading capacity of CO₂ and absorption rate, the absorption experiments in a blend of additives with potassium carbonate were carried out using the vapor-liquid equilibrium apparatus at a temperature of 313.15 K, CO₂ partial pressures ranging from 0 to 50 kPa and at mole fractions 0.2, 0.3, and 0.4. Furthermore, the performance of CO₂ absorption in these blend solutions was compared with pure monoethanolamine and with pure potassium carbonate. Finally, a correlation with good accuracy was developed using the nonlinear regression analysis in order to predict CO₂ loading capacity.

Keywords: absorption rate, carbon dioxide, CO2 capture, global warming, loading capacity

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Authors: Nikhil V. Nayak

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In this paper, the influence of air cooling intake on the gas turbine performance is presented. A comparison among different cooling systems, i.e., evaporative and cooling coil, is performed. A computer simulation model for the employed systems is developed in order to evaluate the performance of the studied gas turbine unit, at Marka Power Station, Amman, Bangalore. The performance characteristics are examined for a set of actual operational parameters including ambient temperature, relative humidity, turbine inlet temperature, pressure ratio, etc. The obtained results showed that the evaporative cooling system is capable of boosting the power and enhancing the efficiency of the studied gas turbine unit in a way much cheaper than cooling coil system due to its high power consumption required to run the vapor-compression refrigeration unit. Nevertheless, it provides full control on the temperature inlet conditions regardless of the relative humidity ratio.

Keywords: power augmentation, temperature control, evaporative cooling, cooling coil, gas turbine

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Authors: Roya Moradifar, Naser Agharezaee

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In this paper corrosion in the liquid sulphur storage tank at South pars gas complex phases 2&3 is presented. This full hot insulated field-erected storage tanks are used for the temporary storage of 1800m3 of molten sulphur. Sever corrosion inside the tank roof was observed during over haul inspections, in the direction of roof gradient. Investigation shown, in spite of other parts of tank there was no insulation around these manholes. Internal steam coils do not maintain a sufficiently high tank roof temperature in the vapor space. Sulphur and formation of liquid water at cool metal surface, this combination leads to the formation of iron sulfide. By employing a distributed external heating system, the temperatures of any point of the tank roof should be based on ambient dew point and the liquid storage solidification point. Also other construction and operation of tank is more important. This paper will review potential corrosion mechanism and operational case study which illustrate the importance of heating systems.

Keywords: tank, steam, corrosion, sulphur

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Authors: Sanchita Baitalik, Nijhuma Kayal, Omprakash Chakrabarti

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Recently SiC ceramics have been a focus of interest in the field of porous materials due to their unique combination of properties and hence they are considered as an ideal candidate for catalyst supports, thermal insulators, high-temperature structural materials, hot gas particulate separation systems etc. in different industrial processes. Several processing methods are followed for fabrication of porous SiC at low temperatures but all these methods are associated with several disadvantages. Therefore processing of porous SiC ceramics at low temperatures is still challenging. Concerning that of incorporation of secondary bond phase additives by an infiltration technique should result in a homogenous distribution of bond phase in the final ceramics. Present work is aimed to synthesis cordierite (2MgO.2Al2O3.5SiO2) bonded porous SiC ceramics following incorporation of sol-gel bond phase precursor into powder compacts of SiC and heat treating the infiltrated body at 1400 °C. In this paper the primary aim was to study the effect of infiltration of a precursor sol of cordierite into a porous SiC powder compact prepared with pore former of different particle sizes on the porosity, pore size, microstructure and the mechanical properties of the porous SiC ceramics. Cordierite sol was prepared by mixing a solution of magnesium nitrate hexahydrate and aluminium nitrate nonahydrate in 2:4 molar ratio in ethanol another solution containing tetra-ethyl orthosilicate and ethanol in 1:3 molar ratio followed by stirring for several hours. Powders of SiC (α-SiC; d50 =22.5 μm) and 10 wt. % polymer microbead of two sizes 8 and 50µm as the pore former were mixed in a suitable liquid medium, dried and pressed in the form of bars (50×20×16 mm3) at 23 MPa pressure. The well-dried bars were heat treated at 1100° C for 4 h with a hold at 750 °C for 2 h to remove the pore former. Bars were evacuated for 2 hr upto 0.3 mm Hg pressure into a vacuum chamber and infiltrated with cordierite precursor sol. The infiltrated samples were dried and the infiltration process was repeated until the weight gain became constant. Finally the infiltrated samples were sintered at 1400 °C to prepare cordierite bonded porous SiC ceramics. Porous ceramics prepared with 8 and 50 µm sized microbead exhibited lower oxidation degrees of respectively 7.8 and 4.8 % than the sample (23 %) prepared with no microbead. Depending on the size of pore former, the porosity of the final ceramic varied in the range of 36 to 40 vol. % with a variation of flexural strength from 33.7 to 24.6 MPa. XRD analysis showed major crystalline phases of the ceramics as SiC, SiO2 and cordierite. Two forms of cordierite, α-(hexagonal) and µ-(cubic), were detected by the XRD analysis. The SiC particles were observed to be bonded both by cristobalite with fish scale morphology and cordierite with rod shape morphology and thereby formed a porous network. The material and mechanical properties of cordierite bonded porous SiC ceramics are good in agreement to carry out further studies like thermal shock, corrosion resistance etc.

Keywords: cordierite, infiltration technique, porous ceramics, sol-gel

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Authors: M. A. Akhavan-Behabadi, M. Najafi, A. Abbasi

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An empirical investigation was performed in order to study the heat transfer characteristics of R600a flow boiling inside horizontal flattened tubes and the simultaneous effect of nanoparticles on boiling heat transfer in flattened channel. Round copper tubes of 8.7 mm I.D. were deformed into flattened shapes with different inside heights of 6.9, 5.5, and 3.4 mm as test areas. The effect of different parameters such as mass flux, vapor quality and inside height on heat transfer coefficient was studied. Flattening the tube caused significant enhancement in heat transfer performance so that the maximum augmentation ratio of 163% was obtained in flattened channel with lowest internal height. A new correlation was developed based on the present experimental data to predict the heat transfer coefficient in flattened tubes. This correlation estimated 90% of the entire database within ±20%.

Keywords: nano particles, flattend tube, R600a, CuO

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Authors: Abdu Zakari, Sai’d Jibril, Adoum A. Omar

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The leaves of Combretum molle was selected on the basis of its uses in folk medicine as insecticides. The leave extracts of Combretum molle was tested against the larvae of Artemia salina, i.e. Brine Shrimp Lethality Test (BST), Culex quinquefasciatus Say (Filaria disease vector) i.e. Larvicidal Test, using crude ethanol, n-hexane, chloroform, ethyl acetate, and methanol extracts. The methanolic extract proved to be the most effective in inducing complete lethality at minimum doses both in the BST and the Larvicidal activity test. The LC50¬ values obtained are 24.85 µg/ml and 0.4µg/ml respectively. The bioactivity-guided column chromatography afforded the pure compound ACM–3. ACM-3 was not active in the BST with LC50 value >1000µg/ml, but was active in the Larvicidal activity test with LC50 value 4.0µg/ml. ACM-3 was proposed to have the structure I, (Cholesta-β-D-Glucopyranoside).

Keywords: toxicity, larvicidal, Combretum molle, Artemia salina, Culex quinquefasciatus Say.

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Authors: I. L. Ibrahim, A. Mann, B. M. Abdullahi

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Infectious diseases are prevalent in developing countries and plant extracts are known to contained bioactive compounds that can be used in the management of these diseases. The entire plant of Chrysanthellum indicum (Linn) was air-dried and pulverized into fine powder and then percolated to give ethanol and aqueous extracts. These extracts were phytochemically screened for metabolites and evaluated antibacterial activity against some pathogenic organisms Klebsilla, pneumonia, Bacillus subtilis, and Pseudomonas aeruginosa using agar dilution method. It was found that crude extracts of C. indicum revealed the presence of saponins, tannins, alkaloids, steroidal nucleus, cardiac glycosides, and coumarin while flavonoids and anthraquinones were absent. The Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) of the active extract of C. indicum shows that the extract could be a potential source of antibacterial agents.

Keywords: antibacterial activity, Chrysanthellum indicum, infectious diseases, phytochemical screening

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Authors: Jeff Letcher, Dennis Tierney, Haider Raad

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Antennas are devices for transmitting and/or receiving signals which make them a necessary component of any wireless system. In this paper, a thermal deposition technique is utilized as a method to fabricate antenna structures on substrates. Thin-film deposition is achieved by evaporating a source material (metals in our case) in a vacuum which allows vapor particles to travel directly to the target substrate which is encased with a mask that outlines the desired structure. The material then condenses back to solid state. This method is used in comparison to screen printing, chemical etching, and ink jet printing to indicate advantages and disadvantages to the method. The antenna created undergoes various testing of frequency ranges, conductivity, and a series of flexing to indicate the effectiveness of the thermal deposition technique. A single band antenna that is operated at 2.45 GHz intended for wearable and flexible applications was successfully fabricated through this method and tested. It is concluded that thermal deposition presents a feasible technique of producing such antennas.

Keywords: thermal deposition, wearable antennas, bluetooth technology, flexible electronics

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Authors: Hikmet Cicek

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Transition metal nitrides are widely used as protective coatings on machine parts and cutting tools to protect the surfaces from abrasion and corrosion for decades. In this study, the ternary TiNbVN thin coatings were produced with closed field unbalanced magnetron sputtering system and their structural, mechanical and fatigue-like (multi-pass scratch test) properties were investigated. Two different substrates (M2 and H13 steels) were used to explore substrates effects. X-Ray diffractometer, scanning electron microscope, and energy dispersive spectroscopy were used for the structural and chemical analysis of the coatings. Nanohardness tests were proceed for mechanical properties. The fatigue-like properties of the coatings obtained from the multi-scratch test under three different cycle passes. The results showed that TiNbVN films have excellent fatigue resistance and the coatings deposited on M2 steel substrate have higher hardness and better fatigue resistance.

Keywords: physical vapor deposition, fatigue, metal nitride, multipass scratch test

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Authors: Dalila Hocine, Mohammed Said Belkaid, Abderahmane Moussi

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In this study, pure rutile TiO2 thin films were directly synthesized on silicon substrates by Atmospheric Pressure Chemical Vapor Deposition technique (APCVD) using TiCl4 as precursor. We studied the physicochemical properties and the optical properties of the produced coatings by means of standard characterization techniques of Fourier Transform Infrared Spectroscopy (FTIR) combined with UV-Vis Reflectance Spectrophotometry. The absorption peaks at 423 cm-1 and 610 cm-1 were observed for the rutile TiO2 thin films, by FTIR measurements. The absorption peak at 739 cm-1 due to the vibration of the Ti-O bonds, was also detected. UV-Vis Reflectance Spectrophotometry is employed for measuring the optical band gap from the measurements of the TiO2 films reflectance. The optical band gap was then extracted from the reflectance data for the TiO2 sample. It was estimated to be 3.05 eV which agrees with the band gap of commercial rutile TiO2 sample.

Keywords: titanium dioxide, physicochemical properties, APCVD, FTIR, band gap

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Authors: S. Tunmee, P. Wongpanya, I. Toda, X. L. Zhou, Y. Nakaya, N. Konkhunthot, S. Arakawa, H. Saitoh

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The hydrogenated amorphous carbon films (a-C:H) were deposited on p-type Si (100) substrates at different thicknesses by radio frequency plasma enhanced chemical vapor deposition technique (rf-PECVD). Raman spectra display asymmetric diamond-like peaks, representative of the a-C:H films. The decrease of intensity ID/IG ratios revealed the sp3 content arise at different thicknesses of the a-C:H films. In terms of mechanical properties, the high hardness and elastic modulus values show the elastic and plastic deformation behaviors related to sp3 content in amorphous carbon films. Electro chemical properties showed that the a-C:H films exhibited excellent corrosion resistance in air-saturated 3.5 wt% NaCl solution for pH 2 at room temperature. Thickness increasing affected the small sp2 clusters in matrix, restricting the velocity transfer and exchange of electrons. The deposited a-C:H films exhibited excellent mechanical properties and corrosion resistance.

Keywords: thickness, mechanical properties, electrochemical corrosion properties, a-C:H film

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Authors: Ana Maria Muț, Georgeta Coneac, Ioana Olariu, Ștefana Avram, Ioana Zinuca Pavel, Ionela Daliana Minda, Lavinia Vlaia, Cristina Adriana Dehelean, Corina Danciu

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Oregano essential oil is obtained from different parts of the plant Origanum vulgare (fam. Lamiaceae) and carvacrol and thymol are primary components, widely recognized for their antimicrobial activity, as well as their antiviral and antifungal properties. Poloxamers are triblock copolymers (Pluronic®), formed of three non-ionic blocks with a hydrophobic polyoxypropylene central chain flanked by two polyoxyethylene hydrophilic chains. They are known for their biocompatibility, sensitivity to temperature changes (sol-to-gel transition of aqueous solution with temperature increase), but also for their amphiphilic and surface active nature determining the formation of micelles, useful for solubilization of different hydrophobic compounds such as the terpenes and terpenoids contained in essential oils. Thus, these polymers, listed in European and US Pharmacopoeia and approved by FDA, are widely used as solubilizers and gelling agents for various pharmaceutical preparations, including topical hydrogels. The aim of this study was to investigate the posibility of solubilizing oregano essential oil (OEO) in polymeric micelles using polyoxypropylene (PPO)-polyoxyethylene (PEO)-polyoxypropylene (PPO) triblock polymers to obtain semisolid systems suitable for topical application. A formulation screening was performed, using Pluronic® F-127 in concentration of 20%, Pluronic® L-31, Pluronic® L-61 and Pluronic® L-62 in concentration of 0.5%, 0.8% respectively 1% to obtain the polymeric micelles-based systems. Then, to each selected system, with or without 10% absolute ethanol, 5% or 8% OEO was added. The obtained transparent poloxamer-based hydrogels containing solubilized OEO were further evaluated for pH, rheological characteristics (flow behaviour, viscosity, consistency and spreadability), using consacrated techniques like potentiometric titration, stationary shear flow test, penetrometric method and parallel plate method. Also, in vitro release and permeation of carvacrol from the hydrogels was carried out, using vertical diffusion cells and synthetic hydrophilic membrane and porcine skin respectively. The pH values and rheological features of all tested formulations were in accordance with official requirements for semisolid cutaneous preparations. But, the formulation containing 0.8% Pluronic® L-31, 10% absolute ethanol, 8% OEO and water and the formulation with 1% Pluronic® L-31, 5% OEO and water, produced the highest cumulative amounts of carvacrol released/permeated through the membrane. The present study demonstrated that oregano essential oil can be successfully solubilized in the investigated poloxamer-based hydrogels. These systems can be further investigated as potential topical therapy for cutaneous papillomas. Funding: This research was funded by Project PN-III-P1-1.1-TE2019-0130, Contract number TE47, Romania.

Keywords: oregano essential oil, carvacrol, poloxamer, topical hydrogels

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Authors: Katarína Koňariková, Georgios A. Perdikaris, Lucia Andrezálová, Zdeňka Ďuračková, Lucia Laubertová, Helena Gbelcová, Ingrid Žitňanová

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Introduction: The continuous demand for new anti-cancer drugs has stimulated chemotherapeutic research based on the use of essential metalloelements with the aim to develop potential drugs with lower toxicity and higher antiproliferative activity against tumors. Copper(II) and its complexes play an important role as suitable species for antiproliferative tests. Objectives: The central objective of the current study was to investigate the potential in vitro anti-proliferative effects of N-salicylidene-L-glutamato copper (II) complexes and molecular mechanism of apoptosis induced by tested complexes. In our project we tested N-salicylidene-L-glutamato copper (II) complexes ZK1 - [Cu(N-salicylidene-L-glutamato)(H2O)2].H2O; MK0 - ([Cu2(N-sal-D,L-glu)2(isoquinoline)2].2H2O); MK1 - [Cu(N-salicylidene-5-methyl-L-glutamato)(H2O)].H2O; MK3 - transbis(ethanol)tetrakis(imidazol)Cu(II)(2+)bis(N-salicylidene-D,L-glutamato-N,O)-KO:KO´-(imidazol); MK5 - [Cu(N-salicylidene-D,L- glutamato)(2-methylimidazol] at concentration range 0.001-100 µmol/L against human colon carcinoma cell line HT-29 and human breast carcinoma cell line MCF-7. Methods: Viability was assessed by direct counting of 0.4% trypan blue dye-excluding cells after 24, 48 and 72 hour cultivations with or without copper complex and by MTT assay. To analyze the type of cell death and its mechanism induced by our copper complex we used different methods. To distinguish apoptosis from necrosis we used electrophoretic analysis, to study the activity of caspases 8 and 9 – luminometric analysis and caspase activity 3 colorimetric assay. Results: The observed anti-proliferative effect of the copper complexes appeared to be dose-, time- and cell line- dependent. Human colon carcinoma cells HT-29 appeared to be more sensitive to the complex MK0 ([Cu2(N-sal-D,L-glu)2(isoquinoline)2].2H2O) than to ZK1 ([Cu(N-salicylidene-L-glutamato)(H2O)2].H2O) and MK1 ([Cu(N-salicylidene-5-methyl-L-glutamato)(H2O)].H2O)). Human colon carcinoma cells HT-29 appeared to be more sensitive to the complex than human breast carcinoma cells MCF-7. IC50 decreased with time of incubation (24, 48 and 72h) for HT-29, but increased for MCF-7. By electrophoresis we found apoptotic cell death induced by our copper complexes in HT-29 at concentrations 1, 10, 50 and 100 µmol/L after 48h (ZK1) and 72h (MK0, MK1) and in MCF-7 we did not find apoptosis. We also studied molecular mechanism of apoptosis in HT-29 induced by copper complexes. We found active caspase 9 in HT-29 after ZK1 ([Cu(N-salicylidene-L-glutamato)(H2O)2].H2O) and MK1 ([Cu(N-salicylidene-5-methyl-L-glutamato)(H2O)].H2O)) influence and active caspase 8 after MK0 ([Cu2(N-sal-D,L-glu)2(isoquinoline)2].2H2O) influence. Conclusion: Our copper complexes showed cytotoxic activities against human colon carcinoma cells HT-29 and breast cancer cell line MCF-7 in vitro. Apoptosis was activated by mitochondrial pathway (intrinsic pathway) in case of ZK1 [Cu(N-salicylidene-L-glutamato)(H2O)2].H2O; MK1 [Cu(N-salicylidene-5-methyl-L-glutamato)(H2O)].H2O; MK3 - transbis(ethanol)tetrakis(imidazol)Cu(II)(2+)bis(N-salicylidene-D,L-glutamato-N,O)-KO:KO´-(imidazol) and MK5 - [Cu(N-salicylidene-D,L- glutamato)(2-methylimidazol] copper complexes and by death receptors (extrinsic pathway) in case of MK0 [Cu2(N-sal-D,L-glu)2(isoquinoline)2].2H2O copper complex in HT-29.

Keywords: apoptosis, copper complex, cancer, carcinoma cell line

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Authors: Marina Stramarkou, Sofia Papadaki, Konstantina Kyriakopoulou, Magdalini Krokida

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Nowadays, microalgae represent the diverse branch of microorganism that is used not only in fish farming, but also in food, cosmetics, pharmaceuticals and biofuel production as they can produce a wide range of unique functional ingredients. In the present work, a remarkable microalga Chlorella vulgaris (CV) was selected as a raw material for the recovery of multifunctional extracts. First of all, the drying of raw biomass was examined with freeze-drying showing the best behavior. Ultrasonic-assisted extraction (UAE) using different solvents was applied under the specific optimized conditions. In case of raw biomass, ethanol was the suitable solvent, whereas on dried samples water performed better. The total carotenoid, β-carotene, chlorophyll and protein content in the raw materials, extracts and extraction residues was determined using UV-Vis spectrometry. The microalgae biomass and the extracts were evaluated regarding their antiradical activity using the DPPH method.

Keywords: antioxidant activity, pigments, proteins, ultrasound assisted extraction

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Authors: M. Simchi, M. Amiri, E. Rezvani, I. Mirzaei, M. Berahman, A. Simchi, M. Fardmanesh

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Graphene is a single-atomic two-dimensional crystal of carbon atoms that has considerable properties due to its unique structure and physics with applications in different fields. Graphene has sensitive electrical properties due to its atomic-thin structure. Along with the substrate materials and their influence on the transport properties in graphene, design and fabrication of graphene-based devices for biomedical and biosensor applications are challenging. In this work, large-area high-quality graphene nanosheets were prepared by low pressure chemical vapor deposition using methane gas as carbon source on copper foil and transferred on the biocompatible substrates. Through deposition of titanium and gold contacts, current-voltage response of the transferred graphene on four biocompatible substrates, including PDMS, SU-8, Nitrocellulose, and Kapton (Fig. 2) were experimentally determined. The considerable effect of the substrate type on the electrical properties of graphene is shown. The sheet resistance of graphene is changed from 0.34 to 14.5 kΩ/sq, depending on the substrate.

Keywords: biocompatible substrates, electrical properties, graphene, sheet resistance

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Authors: Abdelaziz Nasr

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This work conducted numerical simulations to examine the impact of the static electric field on a falling-film evaporation system. A constant electric field can alter the dynamics of a liquid film by modifying the heat and mass transfer properties of the system. The geometry problem consists of two parallel plates in a vertical channel, with the left plate experiencing a constant heat flux and the liquid flowing downward over it, while the right plate remains dry and maintains a constant temperature. The gaseous component consists of dry air and water vapor, whilst the liquid component comprises a thin coating of water. The results suggest that the electric field's impact on heat and mass transport, as well as the evaporation of the liquid sheet, is minimal. Experimental evidence demonstrates that the electric field exerts a minor influence on heat, mass transport, and liquid film evaporation at elevated electric field intensities.

Keywords: electric field, evaporation, liquid film, heat and mass transfer

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Authors: Ene Rosemary Ndidiamaka, Nwangwu Florence Chinyere

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The physiochemical properties of the melon seed oil was studied to determine its potentials as viable feed stock for biodisel production. The melon seed was extracted by solvent extraction using n-hexane as the extracting solvent. In this research, methanol was the alcohol used in the production of biodiesel, although alcohols like ethanol, propanol may also be used. Sodium hydroxide was employed for the catalysis. The melon seed oil was characterized for specific gravity, pH, ash content, iodine value, acid value, saponification value, peroxide value, free fatty acid value, flash point, viscosity, and refractive index using standard methods. The melon seed oil had very high oil content. Specific gravity and flash point of the oil is satisfactory. However, moisture content of the oil exceeded the stipulated ASRTM standard for biodiesel production. The overall results indicates that the melon seed oil is suitable for single-stage transesterification process to biodiesel production.

Keywords: biodiesel, catalyst, melon seed, transesterification

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Authors: Suraiya Abdul Rahman, Perasna M. Varma, Amrahi Buang, Zhari Ismail, Wan Rosalina W. Rosli, Ahmad Rashidi M. Tahir

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Background: Muslims has the obligation to ensure that everything they consume including medicines should be halal. With the growing demands for halal medicines in October 2012, Malaysia has launched the world's first Halal pharmaceutical standards called Malaysian Standard MS 2424:2012 Halal Pharmaceuticals-General Guidelines to serve as a basic requirement for halal pharmaceuticals in Malaysia. However, the biggest challenge faced by pharmaceutical companies to comply is finding the origin or source of the ingredients and determine their halal status. Aim: This study aims to determine the halal status of the antineoplastic and immunomodulating agents, and nutritional and dietary supplements by analysing the origin of their active pharmaceutical ingredients (API) and excipients to provide an insight on the common source and halal status of pharmaceutical ingredients and an indication on adjustment required in order to be halal compliance. Method: The ingredients of each product available in a government hospital in central of Malaysia and their sources were determined from the product package leaflets, information obtained from manufacturer, reliable websites and standard pharmaceutical references. The ingredients were categorised as halal, musbooh or haram based on the definition set in MS2424. Results: There were 162 medications included in the study where 123 (76%) were under the antineoplastic and immunomodulating agents group, while 39 (24%) were nutritional and dietary supplements. In terms of the medication halal status, the proportion of halal, musbooh and haram were 40.1% (n=65), 58.6% (n=95) and 1.2% (n=2) respectively. With regards to the API, there were 89 (52%) different active ingredient identified for antineoplastic and immunomodulating agents with the proportion of 89.9% (n=80) halal and 10.1% (n=9) were mushbooh. There were 83 (48%) active ingredient from the nutritional and dietary supplements group with proportion of halal and masbooh were 89.2% (n=74) and 10.8% (n=9) respectively. No haram APIs were identified in all therapeutic classes. There were a total of 176 excipients identified from the products ranges. It was found that majority of excipients are halal with the proportion of halal, masbooh and haram were at 82.4% (n=145), 17% (n=30) and 0.6% (n=1) respectively. With regards of the sources of the excipeints, most of masbooh excipients (76.7%, n = 23) were classified as masbooh because they have multiple possible origin which consist of animals, plant or others. The remaining 13.3% and 10% were classified as masbooh due to their ethanol and land animal origin respectively. The one haram excipient was gelatine of bovine-porcine origin. Masbooh ingredients found in this research were glycerol, tallow, lactose, polysorbate, dibasic sodium phosphate, stearic acid and magnesium stearate. Ethanol, gelatine, glycerol and magnesium stearate were the most common ingredients classified as mushbooh. Conclusion: This study shows that most API and excipients are halal. However the majority of the medicines in these products categories are mushbooh due to certain excipients only, which could be replaced with halal alternative excipients. This insight should encourage the pharmaceutical products manufacturers to go for halal certification to meet the increasing demand for Halal certified medications for the benefit of mankind.

Keywords: antineoplastic and immunomodulation agents, halal pharmaceutical, MS2424, nutritional and dietary supplements

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Authors: Chien-Wan Hun, Shao-Fu Chang, Chien-Chon Chen, Ker-Jer Huang

Abstract:

This study presents how to use a high-efficiency process for producing cesium iodide (CsI) crystal columns by rapid heating method. In the past, the heating rate of the resistance wire heating furnace was relatively slow and excessive iodine and CsI vapors were therefore generated during heating. Because much iodine and CsI vapors are produced during heating process, the composition of CsI crystal columns is not correct. In order to enhance the heating rate, making CsI material in the heating process can quickly reach the melting point temperature. This study replaced the traditional type of external resistance heating furnace with halogen-type quartz heater, and then, CsI material can quickly reach the melting point. Eventually, CsI melt can solidify in the anodic aluminum template forming CsI crystal columns.

Keywords: cesium iodide, high efficiency, vapor, rapid heating, crystal column

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Authors: Jie Yin, Jun Zhang

Abstract:

Measuring the growth performance and critical supersaturation of particle group have a high reference value for constructing a supersaturated water vapor environment that can improve the removal efficiency of the high-concentration particle group. The critical supersaturation and the variation of the growth performance with supersaturation for high-concentration particles were measured by a flow cloud chamber. Findings suggest that the influence of particle concentration on the growth performance will reduce with the increase of supersaturation. Reducing residence time and increasing particle concentration have similar effects on the growth performance of the high-concentration particle group. Increasing particle concentration and shortening residence time will increase the critical supersaturation of the particle group. The critical supersaturation required to activate a high-concentration particle group is lower than that of the single-particle when the minimum particle size in the particle group is the same as that of a single particle.

Keywords: sub-micron particles, heterogeneous condensation, critical supersaturation, nucleation

Procedia PDF Downloads 157

Authors: Badrun Taman

Abstract:

This study aims to review the use of the Bengkulu Provincial Government Mess as the location of rukyatul hilal because its determination has not been carried out scientifically. There are three things that will be analyzed, namely geographical-astronomical conditions, the suitability of the location with ideal criteria, and the determination of the location of rukyatul hilal in accordance with regional conditions based on the results of the study. The research method used is qualitative with an astronomical geographical approach. The results showed that the factor that strengthened the disturbance from the weather aspect was the western sky horizon in the form of the Indian Ocean sea level. The potential for geographical disturbances on this horizon is high sea waves, relatively high sea breezes, and more seawater vapor due to sea surface temperatures and high air humidity. This study found new criteria for determining the location of the observation crescent. The criteria is the western horizon is not sea level (especially the Indian Ocean).

Keywords: criteria, location, Rukyatul Hilal, tropics, Indian ocean

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Authors: Ahmad Kayvani Fard, Yehia Manawi

Abstract:

Qatar’s primary source of fresh water is through seawater desalination. Amongst the major processes that are commercially available on the market, the most common large scale techniques are Multi-Stage Flash distillation (MSF), Multi Effect distillation (MED), and Reverse Osmosis (RO). Although commonly used, these three processes are highly expensive down to high energy input requirements and high operating costs allied with maintenance and stress induced on the systems in harsh alkaline media. Beside that cost, environmental footprint of these desalination techniques are significant; from damaging marine eco-system, to huge land use, to discharge of tons of GHG and huge carbon footprint. Other less energy consuming techniques based on membrane separation are being sought to reduce both the carbon footprint and operating costs is membrane distillation (MD). Emerged in 1960s, MD is an alternative technology for water desalination attracting more attention since 1980s. MD process involves the evaporation of a hot feed, typically below boiling point of brine at standard conditions, by creating a water vapor pressure difference across the porous, hydrophobic membrane. Main advantages of MD compared to other commercially available technologies (MSF and MED) and specially RO are reduction of membrane and module stress due to absence of trans-membrane pressure, less impact of contaminant fouling on distillate due to transfer of only water vapor, utilization of low grade or waste heat from oil and gas industries to heat up the feed up to required temperature difference across the membrane, superior water quality, and relatively lower capital and operating cost. To achieve the objective of this study, state of the art flat-sheet cross-flow DCMD bench scale unit was designed, commissioned, and tested. The objective of this study is to analyze the characteristics and morphology of the membrane suitable for DCMD through SEM imaging and contact angle measurement and to study the water quality of distillate produced by DCMD bench scale unit. Comparison with available literature data is undertaken where appropriate and laboratory data is used to compare a DCMD distillate quality with that of other desalination techniques and standards. Membrane SEM analysis showed that the PTFE membrane used for the study has contact angle of 127º with highly porous surface supported with less porous and bigger pore size PP membrane. Study on the effect of feed solution (salinity) and temperature on water quality of distillate produced from ICP and IC analysis showed that with any salinity and different feed temperature (up to 70ºC) the electric conductivity of distillate is less than 5 μS/cm with 99.99% salt rejection and proved to be feasible and effective process capable of consistently producing high quality distillate from very high feed salinity solution (i.e. 100000 mg/L TDS) even with substantial quality difference compared to other desalination methods such as RO and MSF.

Keywords: membrane distillation, waste heat, seawater desalination, membrane, freshwater, direct contact membrane distillation

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Authors: Mustafa Ümi̇t Ünal, Nafi̇z Çeli̇ktaş, Aysun Şener, Sara Betül Dolgun, Duygu Keser

Abstract:

The aim of this study was to compare acid and base pretreatment of switchgrass for bioethanol production. Switchgrass was pretreated with sulfuric acid and sodium hydroxide at 0.5, 1.0 and 1.5% (v/v) at 120, 140, 180 °C for 10, 60 and 90. Optimization of enzymatic hydrolysis of the pretreated switchgrass samples were carried out using three different enzyme mixtures (22.5 mg cellulase and 75 mg cellobiase /g biomass; 45 mg cellulase and 150 mg cellobiase /g biomass; 90 mg cellulase and 300 mg cellobiase /g biomass). Samples were removed at 24-h interval for fermentable sugar analyses with HPLC. The results showed that use of 90 mg cellulase and 300 mg cellobiase/g biomass resulted in the highest fermentable sugar formation. Furthermore, the highest fermentable sugar yield was obtained by pretreatment at 120 °C for 10 min using 1.0 % sodium hydroxide.

Keywords: switchgrass, acid pretreatment, enzymatic hydrolysis, base pretreatment, ethanol production

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Authors: Sina Aghili, Ali Arasteh Nodeh

Abstract:

Tamarisk usage as a new group of lignocelluloses material to produce fermentable sugars in bio-ethanol process was studied. The overall aim of this work was to establish the optimum condition for acid hydrolysis of this new material and a mathematical model predicting glucose release as a function of operation variable. Sulfuric acid concentration in the range of 20 to 60%(w/w), process temperature between 60 to 95oC, hydrolysis time from 120 to 240 min and solid content 5,10,15%(w/w) were used as hydrolysis conditions. HPLC was used to analysis of the product. This analysis indicated that glucose was the main fermentable sugar and was increased with time, temperature and solid content and acid concentration was a parabola influence in glucose production.The process was modeled by a quadratic equation. Curve study and model were found that 42% acid concentration, 15 % solid content and 90oC were in optimum condition.

Keywords: fermentable sugar, saccharification, wood, hydrolysis

Procedia PDF Downloads 335