Chimie și Știința Materialelor
Five recipes based on poly-3(hydroxybutyrate) (PHB), wood fiber (WF) and epoxidated soy-bean oil (LSA) were prepared by Brabender Plastograf, at 170 0C. It was found that with increasing wood fibers content in the PHB matrix, the tensile strength and the melting temperature decrease, due to the poor compatibility betwe…
picture_as_pdfText integral (PDF)We disclose the synthesis of some organometallic polymers containing arene- tricarbonyl-chromium complexes. Several approaches were used for this purpose, such as ligand exchange and grafting by electrophilic aromatic substitution with benzylic carbocations stabilized by tricarbonylchromium groups. These polymers can b…
picture_as_pdfText integral (PDF)The demand for new ecological technology lately enhanced, due to the strict environmental regulations introduced. Textile processes are characterized by high pollution, generated by the large amount of waste waters with acid or alkaline pH. Thus, the application of enzymatic work-up procedures seems of great interest. …
picture_as_pdfText integral (PDF)This work is devoted to the electrochemical study of ethyl 3-(4-methylbenzoyl) indolizine-1-carboxylate and ethyl 3-[(2-ethylphenyl)carbamoyl] indolizine-1-carboxylate by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). There are established the number and characteristics of the redox processes for eac…
picture_as_pdfText integral (PDF)Citric acid is traditionally produced using the filamentous fungus Aspergillus Niger. One advantage of Aspergillus Niger is its ability of fermenting substrates which come as waste products from other process. The use of whey as carbon source is very attractive because this raw material is cheap. In this work is presen…
picture_as_pdfText integral (PDF)2-Chlorovinylarsine dichloride (Lewisite 1) identification by gas chromatography is not a simple analysis, because it requires high concentration levels in sample (several mg/ml), very clean systems with new columns, a specially prepared injection port liner and on-column injection. Moreover, derivatization is highly d…
picture_as_pdfText integral (PDF)In this paper, based on the experimental data of surface tension of rubber solutions and contact angle, the values of some parameters involved in adhesion process, as solid-liquid surface tension, work of wetting, work of adhesion, superficial concentration and surface area occupied by an elastomer macromolecule were c…
picture_as_pdfText integral (PDF)The paper presents a comparative investigation on the microstructure of different partially hydrolysed polyvinyl alcohols used in PVC-S technology. Average acetate-containing sequence length and their distribution in partially hydrolyzed polyvinyl alcohols as well as their “blockiness” have been investigated via 1H-NMR…
picture_as_pdfText integral (PDF)The paper studies the hydrodynamic of the gas/solid fluidization in a transverse magnetic field of ferromagnetic particles (commercial steel). The influence of solid (magnetic and non-magnetic particles) characteristics, and the magnetic field intensity (in the range of 0-12000 A.m-1), on the pressure drop and porosity…
picture_as_pdfText integral (PDF)Sludge and waste waters carrying chromium compounds are embarrassing environmental burdens for the both tanning and leather processing industries, as well as for many other manufacture branches involving extraction and use of the chromium chemicals. This paper approaches the chromium removal from waste waters and sludg…
picture_as_pdfText integral (PDF)This paper presents our experimental results on the bio-functionalization of silicon nanoparticles (SiNP) with a polymer, chitosan. The procedure consists of two steps and it was developed in order to bind efficiently and effectively chitosan biopolymer to the silicon nanoparticles surface. Using triethoxsilylbutyralde…
picture_as_pdfText integral (PDF)The recycle and purge ratios are responsible for the two of the main time scales of the wastewater treatment facility, the residence time of the biological reactors, and the doubling time of the microorganisms accountable for the biodegradation of substrates. The effects of threshold imposed to the recirculation and pu…
picture_as_pdfText integral (PDF)The nitrogen fixing bacteria have stimulating effect on the plant, they are able to fix the nitrogen in symbiosis with leguminous plants using the nitrogenase enzyme complex14. The isolation of the strains was made from the soil on selective media, and the strains were characterised through colony morphology analysis (…
picture_as_pdfText integral (PDF)Forensic chemistry performs qualitative and quantitative analysis of chemicals found on people, various objects, or in solutions. The final result of the forensic scientist’s work, the expert report, has a direct influence on the fate of given individuals. This burden implies a high responsibility that determines the w…
picture_as_pdfText integral (PDF)Functionalization of multiwalled carbon nanotubes (MWNTs) may improve the thermal and mechanical properties of the epoxy composites in which they are embedded as reinforcing agents. Amine groups were chosen to functionalize the carboxylated MWNTs due to their potential to form bonds with the epoxy resin used as polymer…
picture_as_pdfText integral (PDF)In this study, we are concerned with the prediction of adsorbed amount of phosphate and the sorption rate on soil particles in a chernozem from agricultural zone. Artificial Neural Networks (ANNs) have been used for modeling the behavior of phosphate (P) pollutant. The findings of numerous research studies also exhibit…
picture_as_pdfText integral (PDF)The paper presents experimental research results on a new concept of oxidation in aqueous medium (solution of sodium carbonate) of copper sulphide concentrate in autoclave under air pressure in the temperature range 100 to 135 oC for 5 h, partial air pressure 5 atm in the presence of 30% excess of sodium carbonate more…
picture_as_pdfText integral (PDF)Equal Channel Angular Pressing (ECAP) is a very interesting method for modifying microstructure in producing ultra fine grained materials (UFG) and nanomaterials (NM). It consists of pressing test samples through a die containing two channels, equal in cross section and intersecting at an angle and a corner angle . …
picture_as_pdfText integral (PDF)The present paper presents the results concerning the morphology by electron microscopy and the way in which temperature and impurities contents may influence the nucleation and growth of the Sn. Tin is a metal with polymorphic phenomenon, with great difference between two allotropic structure and .. The polymorph…
picture_as_pdfText integral (PDF)Nanoparticles such as silica have been widely used for reinforcing polymer systems. Incorporation of nanoparticles in the manufacture of nanocomposite polymer matrix provides a method for obtaining hybrid materials that integrate the characteristics of each component in the final material obtained. The mixture of organ…
picture_as_pdfText integral (PDF)The paper discusses the possibility to apply a treatment to the liquid metallic materials and their crystallization under the influence of mechanical vibrations. To demonstrate the existence of the effect of the mechanic vibrations we tried to make them evident by solving two problems: 1 - by designing and implementing…
picture_as_pdfText integral (PDF)The paper presents the results obtained in the selective recovery of gold from hydrochloric solutions using Amberlite XAD-7 ion-exchange resin. Experimental tests were conducted on real solutions obtained following selective leaching of gold from different metallurgical wastes, through wet chlorination. It was noticed …
picture_as_pdfText integral (PDF)The present paper presents the data obtained as a result of the determination of the soluble/insoluble part of Ca and Al and the study of Al and Ca inclusions in aircraft steel samples When analyzing the samples, I used the Spark-Dat method and I analyzed the inclusion with the help of the 21 NEOPHOT Metallographic Mic…
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