48 research outputs found
Mechanical And Thermal Properties Of Thermally Conductive Fillers Filled Polypropylene Composites
The current study was carried out to investigate the effect of various fillers for example (such as) carbon nanotube (MWNT), synthetic diamond (SD), boron nitride (BN) and copper (Cu) on the properties of polypropylene (PP) composites. This composite was compounded using two roll mill mixing method and the filler content was loaded from 1 to 4 volume %. It was observed that the PP/SD, PP/BN and PP/Cu exhibited maximum tensile strength at 2 volume % and a reduction trend can be observed after 2
volume %. Scanning electron microscopy (SEM) was used to examine the fractured structure of the composites, and it was observed that agglomeration increased as the
filler loading increased. Thermal conductivity, thermal stability, coefficient of thermalexpansion (CTE) and storage modulus of the composites were improved by addition of fillers in PP. Among these four fillers, MWNT showed greater potential in improving thermal properties of PP composites. In the second series, the effects of hybrid filler (MWNT/SD and MWNT/BN) in PP composites were studied. The results showed that the thermal conductivity, thermal stability, coefficient of thermal expansion and storage modulus of the hybrid composites were improved if compared to single fillers composites. However, the tensile and flexural properties of hybrid composites were noted to be lower than the single composites. In the third series, the improvements in
the compounding were carried out by using two compounding methods; planetary ball mill and two roll mill. Enhancement in strength, stiffness, thermal conductivity and storage modulus of the composites has been observed in this system. Nevertheless, the thermal stability was found to be reduced as the two compounding methods were used in the fabrication process
Synthesis of A Novel Carrier Compound Thiazoethyl Methyl Eugenoxyacetate from Eugenol and Its Use in the Bulk Liquid Membrane Technique
Research into the synthesis and use of a novel carrier compound, thiazoethyl methyl eugenoxyacetic acid
(TMEAA) for selective transport of Cu(II), Cd(II) and Cr(III) metal ions in the bulk liquid membrane (BLM) technique
was conducted. TMEAA was synthesized from eugenol by acidification into eugenoxyacetic acid and subsequently
esterified using 4-methyl-5-thiazoethanol. Analysis of the result was performed using GC-MS and FTIR. The TMEAA
obtained was liquid, viscous, blackish-brown and fragrant, with a yield of 88%. This compound was soluble in
benzene and chloroform but insoluble in methanol. The GC-MS analysis showed the presence of a single peak, with
a retention time of 26.5 min, while the disappearance of vibration mode at 1727 cm-1 was attributed to acid
absorption and the FTIR spectrum indicated that formation of an ester group had occurred. TMEAA was used as a
carrier compound in the BLM technique to transport Cu(II), Cd(II) and Cr(III), using chloroform as a solvent. The
results showed that TMEAA was more selective for Cu(II) and Cd(II) than Cr(III). Moreover, the research proved that
N and S groups of TMEAA were selective for Cu (II) and Cd (II)
Determination of the color temperature in laser-produced shocks
Experimental results on the determination of the color temperature in shock waves produced with lasers are presented. The method is based on imaging the target rear side in two different spectral windows and on using phased zone plates to produce high-quality shocks. The shock velocity is also measured, allowing, with the use of the equation of state, the real shock temperature to be deduced and compared with the measured color temperature
Electric Field Characteristics of HDPE-NR Biocomposite Under Breakdown Condition
It is critical to develop new insulating materials that can improve the performance of next generation high voltage cables for creating future electrical networks. The high electric field reduces the resistance of solid insulation and produces partial discharge through imperfections in a dielectric, causing the dielectric to age and eventually fail. Thus, this project seeks to analyse the electric field intensity of High Density Polyethylene (HDPE) in breakdown condition when added with 10g, 20g and 30g of different types of bio-filler such as coconut coir fibre, pineapple leaves fibre, and oil palm empty fruit bunch. This can be achieved by creating a two-dimensional (2D) axisymmetric electrostatic model by using the Finite Element Method Magnetics (FEMM) 4.2 software. The results showed that the unfilled HDPE biocomposites have a higher electric field intensity than 10g, 20g, and 30g biocomposite. This indicates that the maximum electric field intensity changes according to the permittivity and voltage of the bio-filler under breakdown conditions. As a result, the maximum electric field intensity was much lower for HDPE added with a 20g of the pineapple leaves fibre. Hence, pineapple leaves fibre was the best composition as it tends to improve the dielectric properties since it has a lower electric field intensity at the top electrode as compared to other compositions
Electric Field Characteristics of HDPE-NR Biocomposite Under Breakdown Condition
It is critical to develop new insulating materials that can improve the performance of next generation high voltage cables for creating future electrical networks. The high electric field reduces the resistance of solid insulation and produces partial discharge through imperfections in a dielectric, causing the dielectric to age and eventually fail. Thus, this project seeks to analyse the electric field intensity of High Density Polyethylene (HDPE) in breakdown condition when added with 10g, 20g and 30g of different types of bio-filler such as coconut coir fibre, pineapple leaves fibre, and oil palm empty fruit bunch. This can be achieved by creating a two-dimensional (2D) axisymmetric electrostatic model by using the Finite Element Method Magnetics (FEMM) 4.2 software. The results showed that the unfilled HDPE biocomposites have a higher electric field intensity than 10g, 20g, and 30g biocomposite. This indicates that the maximum electric field intensity changes according to the permittivity and voltage of the bio-filler under breakdown conditions. As a result, the maximum electric field intensity was much lower for HDPE added with a 20g of the pineapple leaves fibre. Hence, pineapple leaves fibre was the best composition as it tends to improve the dielectric properties since it has a lower electric field intensity at the top electrode as compared to other compositions
Electrochemical Oxidation of Phenol using a Flow-through Micro-porous Lead Dioxide/Lead Cell
The electrochemical oxidation of phenol to benzoquinone followed by the reduction to hydroquinone and catechol was demonstrated by constructing a three-dimensional porous micro-flow cell from lead dioxideand lead. The electrodes were made by using the principles of curing and formation of lead oxide material that are common in the construction of the electrodes used in lead-acid batteries. This resulted in highly porous electrodes that can allow the reactant solution to flow through them in series, without the risk of having the products being oxidized again at the anode that usually occurs in a simple undivided cell. In this study, a 50 mM solution of phenol in a 60 % acetonitrile and water mixture was used that contained 2 % sulphuric acid. The reactantsolution would flow through the anode porous material oxidizing the phenol to benzoquinone. The benzoquinone in solution would then flow through the cathode porous material and reduce to catechol and hydroquinone. The study showed that almost all of the phenol could be converted in one continuous flow process in using a relatively low cost electrochemical micro-flow cell that can be easily scaled up to accommodate larger volumes and concentrations by using electrode manufacturing principles used in the lead-acid battery industry.Keywords: Phenol, hydroquinone, catechol, lead dioxide, micro-flow cel
Sorption and Biosorption of Petroleum Pollutants from Water Samples Using Biochar, Hydrocarbon Degrading Microorganisms and Their Combination
Petroleum pollutants and organic waste are both important environmental issues. Biochar is a highly complex and heterogenous material consisting of both organic and inorganic compounds obtained by thermal degradation of organic wastes. Using biochar for removal of petroleum pollutants could decrease the environmental impact of both petroleum pollutants and organic waste. Furthermore, immobilising microorganisms on biochar could increase removal trough the effect of biosorption and eventually biodegradation. The aim of this research was to examine the efficiency of removal of petroleum hydrocarbons using biochar, microbial consortium and their
combination. Microorganisms were isolated from soil polluted with hydrocarbons and enriched on media supplemented with diesel, while two biochar samples (made from wheat straw pellets and sewage sludge) were used as adsorbers and carriers for immobilization of these hydrocarbon degrading microorganisms.
The remediation study was performed on water samples prepared in laboratory condition by adding crude oil and minerals into the distilled water. The period of the remediation was 96 days, while the analysis of the removal and degradation of petroleum pollutants was performed every 32 days for each sample.
Measurement of the removal of total petroleum pollutants was followed gravimetrically measuring fraction of extracted soluble organic matter, separated saturated and aromatic fractions of crude oil that remained in water phase. Furthermore, saturated and aromatic fractions were analysed by GC-MS. From the obtained results it can be seen that more than 99% of crude oil was removed from numerous water samples and that microorganisms primarily degrade n-alkanes over other groups of compounds.
In further studies, if method effectiveness proven successful, should be tested on real samples and it should be scaled up for industrial purposes
Engineered Bioremediation - Technology of Choice for Treatment of Aquifer Contaminated with Oil Pollutants
This paper presents the engineered bioremediation of aquifers contaminated by petroleum hydrocarbons, in the process which lasted for 12 months. The contaminated area was
located near the city of Belgrade (Serbia), on the terrace sediments of the Sava River. This
remediation treatment was performed within the closed bipolar system (one extraction and two
injection wells), with adsorption in the external unit.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5462
Biohydrometallurgical Methods for Cobal and Nickel Recovery from Printed PC Motherboard
E-waste is one of the fastest growing waste. Ewaste contains lots of valuable resources together
with plenty of heavy metals and hazardous materials, which are considered both an attractive
polymetallic secondary source and an environmental contaminant. Therefore, recycle of
valuable metallic from them are necessary and compulsory in many developed/developing
countries.
The aim of our study was to investigate the potential of using the Acidithiobacillus sp. B2, to
recovery Co and Ni from printed PC motherboard.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5460
Белки-нуклеаторы бактериального происхождения. Сообщение III. Регуляция активности и значение в природе и биотехнологии
В обзоре представлены накопленные сведения о регуляции активности бактериальных белков-нуклеаторов, рассмотрены
основные области применения биологических нуклеаторов и кодирующих их генов в биотехнологии.В обзорі наведено накопичені відомості стосовно регуляції активності бактеріальних білків-нуклеаторів, розглянуто основні
галузі застосування біологічних нуклеаторів та генів, які їх кодують, в біотехнології.The information that has been gathered so far on the regulation of bacterial nucleation protein activity is presented in the review;
the main fields of applications of biological nucleators and their encoding genes in biotechnology are discussed