Om Prakash   Babita Belal   Jyotsna Dhanik   Anil Verma   Hem C Joshi   and Vivekanand   

The main aim of this study is to determine the changes occurred in the antioxidant capacity and UV-protection capacity of rutin with a different redox-potential metal cation. The complexes were characterized by UV-Visible and IR spectroscopy. Rutin belongs to the flavonols and it is a glycoside form of quercetin. Chelate formation is a result of interaction of rutin with metal ions. The chelation of metals can be crucial in the prevention of radical generation, which damages target biomolecules. The interactions between flavonoids and transition metal ions to form complexes that prevent the participation of metal ions in free radical generating processes, thus exhibit an anti-oxidant behavior, metal-flavonoid complexes various biological and pharmacological activities. The coordination of Rutin (Rut) with Rut-Zr, Rut-Mo, Rut-Zn, Rut-Cu, Rut-Ni, Rut-Fe, Cit-Zn, Cit-Mo, Cit-Zr, Cit-Cu, Cit-Fe, and Cit-Ni may simulate the catalyzed centre of the hyperoxide dismutase in the metal coordinate structure, thus displayed the DPPH, hydroxyl radical scavenging activity, metal chelating, and nitric oxide (NO) and superoxide dismutase (SOD) radical scavenging. Therefore, the metal flavonoid complexes are very helpful in discovery and development of new drugs.

Shannon G. Lieb   and Paula LeBlanc   

The doubly hydrogen-bonded dimer of pyrrolidinone (γ-lactam) is used as a benchmark for the effect of conjugation on the strength and extent of hydrogen-bonding of the compounds Oxindole and Isoxindole. The experimental portion of this project consists of collecting the FTIR spectrum of γ-lactam, Oxindole and Isoxindole in CCl₄. The concentrations and temperatures were varied to determine the thermodynamic properties of ΔH_d, ΔS_d and K_d. In addition, the spectroscopic parameters of the difference of the monomer and dimer N-H stretching frequencies (Δν) and the ratio of the molar extinction coefficients of the dimer and monomer (ε_d/ε_m) are experimentally determined. The values of ΔH_d, ΔS_d, Δν and ε_d/ε_m are computed using MP2 and B3LYP methods with 6-31G** and 6-31+G** basis sets. The experimental values are best described by B3LYP/6-31G**with the incorporation of the dielectric effect (PCM) of CCl₄. The experimental and computational results support the results of increased or decreased hydrogen-bond strength due to conjugation effects on the polarization of the monomers in forming dimers.

Veronika Poltavets   Viktor F. Vargalyuk   and Lyudmila Shevchenko   

Oxidation catalysis of organic substances has attracted special attention in recent years due to of their high industrial significance in green and energy chemistry. The implementation of a transition metal-based catalyst in combination with oxygen is an alternative to the traditional procedures. This study justifies the application of amperometric response 'in situ' for estimation of the electrocatalytic activity of metal oxide films, which are known to be promising for oxygen transfer processes. The reaction of electrooxidation of Mn²⁺ ions may be termed as a 'marker' for oxygen transfer reactions due to its kinetic features, such as proportionality between the current density and the surface concentration of •OH-radicals. The relative parameter, k_ox, has been offered for estimation of the oxidizing capacity of an anode material toward oxygen transfer reaction in reference to platinum oxidizing capacity. k_ox value is automatically calculated exactly during electroplating of MnO_x as a ratio of the current density of Mn²⁺ + 2H₂O – 2e→MnO₂+4H⁺ reaction on the tested surface to the current density of this reaction on Pt surface. The developed method was tested during the investigation of catalytic activity of MnO_x films for electrooxidation of glucose. The parameter k_ox was calculated for other anode materials and was analyzed. The application of the new method allows estimating and comparing the catalytic performance toward oxygen transfer reactions of anode materials or of the same material in different modifications, such as nano particles, composites, different compositions etc. The pre-test reduces manifold the time spent for determination of oxidizing capacity of oxides.

T. Gaza   and J. Kugara   

Air pollution is a problem in both developed and developing countries. As a corrective measure, constant air monitoring is usually performed by conventional techniques which are costly and time consuming hence the need for cheaper methods. Recently, biomonitoring has emerged as an effective alternative method. The aim of this study was to investigate heavy metal air pollution in the environment using Mosses. Mosses are lower plants that can provide a surrogate and time-integrated means of measuring elemental depositions from the atmosphere to terrestrial systems. Atmospheric deposition of heavy metals Chromium (Cr), Copper (Cu), lead (Pb), and Zinc (Zn) was studied at the University of Zimbabwe. Moss samples were hung on sites selected by a systematic grid sampling method, during the summer of 2016. The concentrations of heavy metals were determined by Atomic Absorption Spectroscopy (AAS). The concentrations were expressed as Relative Accumulation Factors (RAFs) and the means for Cr, Cu, Pb and Zn were 14.38; 18.17; 9.63 and 10.78 respectively. The results showed the concentration order of deposition was Cu > Cr > Zn >Pb and that Zn deposited uniformly as evidenced by its low sample variance which was more than 17 and 56 times smaller than that of Pb and Cr-Cu respectively. Although the distribution patterns of Cr and Cu were similar, Pb and Zn had their own patterns. The results suggested that the source of heavy metal could be from traffic related air pollutants.

Ifeanacho, M.O.   Agomuo E.N.   and Amadi, P.U.   

This study was carried out to assess the levels of the metabolites of Aspergillus flavus; aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2) in various food samples. Corn (24.00 µg/kg), millet (4.13 µg/kg), and cassava (3.88 µg/kg) contained the highest AFB1, while AFB2, AFG1, and AFG2 occurred highest in corn and yam. After processing, cassava and yam recorded the highest percentage of AFB1 and AFB2 reduction respectively, while the decontamination of AFG1 was jointly most effective after wheat and millet processing, and AFG2 reduced most after wheat, cassava, and millet processing. The occurrence of AFB1 in the legumes, followed the order; beans > breadfruit > groundnut > melon > oil bean and for AFB2 and AFG2 levels, breadfruit > melon > oil beans > beans, while AFG1 occurred highest in breadfruit, groundnut and oil beans. Ugba (6.26 µg/kg), Ogiri (10 µg/kg), and beans flour (14.62 µg/kg) had the least total aflatoxin contents of the legumes evaluated. Egusi, beans and oil bean recorded over 80% AFB1 and AFG1 reduction, while processing of groundnut and breadfruit, and breadfruit and melon produced the highest percentage of AFB2 and AFG2 respectively. The result for the vegetables showed least contamination of AFB1 in nchuanwu and bitter leaf, while the occurrence of AFB2, AFG1, and AFG2 in nchuanwu and bitter leaf occurred below detection levels. Blanched nchuanwu and bitter leaves had 100% AFB1 reduction, while the percentage reductions of AFB2 in oha and curry leaves, AFG1 in oha, and AFG2 in pumpkin leaves were 100%. This study has shown the presence of aflatoxins in the foods beyond permissible limits, as well as the effectiveness of milling, fermentation and blanching in reducing aflatoxins from carbohydrate rich foods, proteins, and vegetables respectively.

Pushpavathi Itte   M.K. Amshumali   and Mussavir Pasha, K.M   

The molecular modeling, geometry optimization and characterization of bimetallic complexes derived from 4, 8-dimethyl-2, 6-diphenyl-1, 5-dihydro-s-indacene has been performed using semi empirical method. The three bimetallic complexes containing transition metals Fe, Ni and Fe-Ni were investigated. Namely, (Cp*Fe)₂Ic', (Cp*Ni)₂Ic', (Cp*Fe)Ic'(Cp*Ni). (Where Cp*=Pentamethyl-ƞ⁵-cyclopentadienyl, Ic'=2, 6 diphenyl-4, 8-dimethyl-s- Indacene.) In these study geometrical parameters, vibrational frequencies, dipole moment and total energies were calculated by PM6, parametric method. The theoretical electronic (UV-Vis) spectrum calculated using TD-SCF (RPM6) in gas phase. The frontier orbital analyses measure the values of HOMO, LUMO energies and their energy gap. The calculated HOMO-LUMO energy gap show that charge transfer occurs within the molecule.

Ndayambaje Jean Bernard   Ingabire Ange Sabine   and Mutuyimana Jean Marie Vianey   

Mycotoxins are toxins produced by aspergillus, a type of fungus that can be found virtually everywhere and their toxicity occurs at very low concentrations. For good storage condition of the post-harvest grains, the sensitive and reliable methods for detecting mycotoxins are required for long-term sustainability of animals ingesting excessive amounts of the toxin from chronic health problem to death. The aspergillus grows rapidly in the air with high relative humidity contrast to the air with low relative humidity. In this study, the samples of maize were randomly collected in three sectors: Nyamata, Gakenke and Mahembe. Using selective media and biochemical tests, the three strains; A. flavus, capable of producing both B- and G-type aflatoxin and A. pseudotamarii which has not previously detected in our region and A. parasiticus, isolated from the collected maize and the total aflatoxin (AFT) in maize flour was evaluated by Reveal Q+; the mean concentrations of AFT were 52.3±3.93 CFU/ml for Mahembe sector, 49.5±0.98 CFU/ml for Gakenke sector and 43.7±2.15 CFU/ml for Nyamata sector. The level of AFT contamination in a, b, c sectors was higher than the maximum tolerable limit of aflatoxins recommended by the United States Food and Drug Administration guidelines for aflatoxin in animal feeds and human foods at 20 parts per billion (20 ppb).

Girish Kumar Sinha   Akanksha Priya   Sonal Priya   and Satyendra Narayan   

An innovative protocol to the synthesis of this material emerged on exploring the potential of the various form of N-aminophthalimides on its reaction with a number of aromatic aldehydes. New series of biologically active substituted Schiff bases with general formula, R1N=CHR2 where R1 = 3-nitro-N-aminophthalimide, 3-bromo-N-aminophthalimide, 4-nitro-N-aminophthalimide, 4-bromo-N-aminophthalimide, R2 =2, 6-dichlorobenzaldehyde, o-anisaldehyde and o-vanillin were synthesized by the reaction of substituted N-aminophthalimides and substituted aldehydes in ethanol. Moreover N-aminophthalimides (50-70% yield) were synthesized by reactions of corresponding phthalimides and hydrazine hydrate. Such compounds were characterized by different physico-chemical techniques like, melting point, elemental analysis, multinuclear NMR (1H, 13C).The synthesized compounds were screened for antibacterial and antifungal activities. The explorations of the biological properties of the compounds are mentioned in this paper.

Sara García-Salgado   Rosa Dominguéz Gómez   and Rosario Torralba Marco   

There is a concern among professionals and teachers of scientific and technological Degrees for the lack of vocations for this type of study. In order to mitigate this problem to some extent, Technical University of Madrid (UPM) and some Educational Innovation Groups, formed by Chemistry teachers, have been worked for some years on the organization of several activities to promote the relation among different educational levels, mainly early High School and University. On the other hand, different teaching materials have been developed in order to encourage the motivation and ease the learning of the basic subjects of the first-year of university studies by the students of UPM, with tools or resources such as Punto de Inicio, OpenCourseWare (OCW), Puesta a Punto, at an institutional level. Furthermore, some Educational Innovation Groups have created audiovisual materials (lab practice videos) and virtual lab practices for the learning of Chemistry, as well as games such as Math-Trivial, Physic-Trivial, Drawing-Trivial and Chemical-Trivial. These tools are available on the Internet, as free access web spaces.

Jiří Kolena   Gabriela Šťávová   Pavel Morávek   and Kamil Štěpánek   

A process of Ni/Al₂O₃ eggshell type catalyst preparation has been developed in laboratory scale. Active catalysts with high Ni content, in which the active metal is concentrated in a very thin layer below the particle surface, were prepared by this process. Wet impregnation of carrier particles with a solution of inorganic Ni salt in organic solvent, in particular ethanol and acetone, was the basic principle of the preparation method. Catalysts with a maximum Ni content of 20.9 mass %, concentrated into a layer of thickness of 770 μm were prepared when ethanol was used as the solvent, while 15.4 % Ni maximum concentration and 622 μm layer thickness were achieved when acetone was used as the solvent. The catalysts prepared were characterized by following analytical methods: XRD, BET, Raman spectroscopy and EDS. The catalysts activities were tested in the gas phase C₅ olefins hydrogenation. Despite the lower Ni content, the catalyst impregnated by Ni nitrate, dissolved in acetone was characterized by higher activity in comparison with the catalyst impregnated by ethanol solution.

Bülent Topcuoğlu   

A study was carried out in intensive greenhouse areas of Kaş district, Antalya to determine the relation among soil properties and metal characteristics, ground water properties and metal contents and greenhouse plant metal contents. Additional to routine water and soil analysis, a sequential extraction procedure was used to estimate the availability of heavy metals (Zn, Cd, Ni and Pb) in greenhouse soils and several environmental pollution indexes were used to evaluate the size of pollution and risks. Groundwaters of greenhouse area have high conductivity and nitrate content, but heavy metal contents were below the permissible levels. Average total Cd, Ni, Pb and As contents of groundwaters were below the pollutant limits, but Zn concentrations were exceeded. However, the average heavy metal evaluation index (HEI) values for all metals in groundwaters were below the critical value. The concentrations of heavy metals with the exception of Ni in soils of greenhouses were generally below the referenced limits. Soil metal speciation showed that the greatest percentage of all metals was present in the residual form, and the mobility of metals declined in the following order: As>Zn>Cd>Pb>Ni. Single factor and composite pollution coefficient values of all metals with the exception of Ni were not exceeded critical limit. Anthropogenic and enrichment factor indexes of greenhouse soils indicate that both two parameters showed similar trends and 1 to 9 fold metal enrichments by anthropogenic inputs compared to uncontaminated soil. Potential ecological risk indexes of soil metals except Ni were found below the threshold value that indicates these metals have a low risk to surrounding environment. All heavy metal concentrations with the exception of Cd in tomato fruits were found below the permissible heavy metal limits. Although soil Ni concentration was excessed the pollutant limits, possibly due to low soil mobility factor of Ni, concentration of Ni in tomato fruit was found very low. However, target hazard quotient (THQ) of tomato fruits was found below the critical value and thus it can be presumable no health risk for Cd metal in short or medium terms. In a comprehensive manner, in addition to total concentrations referenced, environmental risk evaluation methods and soil speciation studies may provide useful information for assessing metal bioavailability and environmental risks.

Vanessa Mota Vieira   and Clédola Cássia Oliveira de Tello   

The Brazilian repository is being planned to be a near-surface one. In Brazil the low and intermediate level radioactive wastes are immobilized using cement and bitumen for Angra 1 and Angra 2 NPP, respectively. The major problems due to the disposal of bituminized wastes in repositories are swelling of the waste products and their degradation in the long term. To accommodate the swelling of the bituminized wastes, the drums are filled up to 70 - 90% of their volume, which reduces the structural repository stability and the disposal availability. Countries, which use bitumen in the solidification of NPP's radioactive waste and have near-surface repositories, need to immobilize this bituminized waste within other drums containing cement pastes or mortars to dispose them. This study aims to evaluate the properties of cement pastes and mortars to be used in the encapsulation of bituminized wastes. The formulations of two pastes and two mortars were selected for the pilot scale tests. The laboratory and pilot scales results were very similar, indicating that any of these formulations could be used. However the better formulation will be chosen after the leaching test results, because it is an essential parameter in the long-term repository performance.

Tulenin S.S.   Tretyakov A.V.   Shaidarov L.V.   Maskaeva L.N.   Maraeva E.V.   and Markov V.F.   

In₂S₃ thin films were grown by means chemical bath deposition from acid solution. Calculation of ionic equilibrium with using of thermodynamic constants for systems defines boundary conditions of formation In₂S₃. Films were characterized by means of XRD, SEM, EDX and XPS methods. According to X-ray analysis In₂S₃ thin films has a cubic structure. XPS method was shown that the surface of In₂S₃ thin film includes oxygen and carbon contained impurities. SEM confirmed nanosized nature of thin films. Optical band gap of indium(III) sulfide equal to 2.3 eV.

Per-Olof Westlund   

Ganglioside GM1 (G_M1) micelles have been studied by means of water proton T₁ NMRD experiment. The field dependent spin-lattice relaxation rates were measured for Larmor frequencies ranging from 0.1 to 40 MHz and for two micelle concentrations at three temperatures (T=10,15,20℃). The proton T₁ NMRD-profiles are well described by assuming two proton pools are responsible for the dispersion curves. The proton pools are characterized by an effective correlation time and a proton fraction. The largest correlation time, T_c,1 ≈ 130-160 ns, is determined by the low field part of the NMRD profile. The second correlation time, T_c,2 ≈12 ns, is determined by the high field part of the NMRD profile. The radius of the ganglioside micelles has previously been determined as about 54 using fluorescence experiments and with Stoke-Einstein relation the reorientation correlation time becomes T_R= 120-165 ns depending on the temperature dependence of the water viscosity. It is thus plausible to identify one pool of waterprotons, characterized by the largest effective correlation time, as corresponding to waters residing in the headgroup with an order parameter S≠0 and T_c,1 ≈ T_R or corresponding to labile protons with a T_c,1 as the mean life time. The proton NMRD profile reveal a second Lorenzian which also can either be labile and exchanging Ganglioside protons or water molecules residing in the head group with a mean life time as approximately 12 ns. The proton NMRD experiment cannot discriminate between these two cases.

Odhiambo J   Yusuf A   and Onyatta J.   

The discharge of industrial effluents into the environment poses a threat to human health and is of environmental concern to both plants and animals. Over the last several years there has been a great deal of pollution caused by sewerage treatment works and industrial plants discharging effluents into the environment. This has been caused to a large extent by rapid population increase in the cities and towns, which has led to a strain on the plants' capacities. The industrial effluents from selected industries in Nairobi's Industrial area, Kenya were analyzed to determine the physico-chemical properties which were then compared to the guidelines of the National Environment Management Authority (NEMA). The effluents were collected from four different industrial sites namely General Plastics Industries Ltd., Bhachu Industries Ltd., Chloride Industries and Sameer Africa. pH, color, temperature, chemical oxygen demand (COD), total suspended solids (TSS), total dissolved solids (TDS) and oil and grease were analyzed using standard analytical methods. The results in range form for the four sites were as follows: pH 7.4-8.7; colour 26-44 Hazen units; temperature 20.5-27.7℃; COD 22.22-96.30 mg/L; TSS 25.00-26.37 mg/L; TDS 1080.7-1225.3 mg/L; Oil and Grease 5.71-12.52 mg/L. pH, colour, and oil and grease for effluent outside Sameer Industries were above NEMA guideline values for discharge into the environment. General Plastic Industries had colour, total dissolved solids and oil and grease all above NEMA guideline values. Colour, total dissolved solids and chemical oxygen demand outside Bhachu Industries were also higher. At Chloride Industries only colour was above the guideline value. There is therefore need to use appropriate treatment methods to lower these values.

K. Mariselvam   and R. Arun Kumar   

The development of borate based glasses for luminescence applications are reviewed. The present work covers various aspects including the search and synthesis of new materials, the formation of glasses, the structural and optical properties of absorption, excitation and luminescence on the prepared glasses, Information on the Judd-Ofelt intensity parameters as calculated from absorption spectra and the studies on the emission properties. CIE colour coordinates are helpful to analyze the potentiality of the glasses for white light emission. We aim to provide a comprehensive review of borate glass materials for LED and screen display applications etc.

Oleksandr Vasylyev   Mykola Brychevskyi   and Yehor Brodnikovskyi   

The paper addresses questions concerning the structural optimization of ceramic fuel cells (CFC) aiming to increase the ionic conductivity realized at long term operation of zirconia electrolyte in the very structure of CFC applying scandia as the stabilizer of zirconia cubic phase and electron beam physical vapor deposition as the production method of the CFC's electrolyte film. Its chemical composition would be optimized in a course of a few iteration processes of a substance transfer from virgin powders into the electrolyte phase of CFC laminated composite, which is changed by diffusion processes between CFC electrolyte and its electrode layers during CFC production and long-term operation. The final, optimized, chemical composition and structure of entire CFC would be tuned by taking into account the structural altering occurring during both production and operation.

Qiang Sun   Yongzhen Liu   Aixian Liu   Xuqiang Guo   and Lanying Yang   

The separation of CO₂ from flue gas by alcohol amine method was investigated in this paper. We conducted the absorption and desorption experiments using different alcohol amines: monoethanolamine (MEA), diethanolamine (DEA), methyl diethanolamine (MDEA), triethanolamine (TEA), piperazine (PZ), and their binary mixtures. Relevant absorption rate and desorption rate of CO₂ were obtained and reported. Aspen Plus was applied to simulate the process of recovering CO₂ from flue gas via absorption of PZ-MEA solution. The influences of the lean liquid CO₂ load, lean liquid temperature and desorber pressure on the reboiler duty were investigated, and the optimal operating parameters were obtained on the basis of the minimum reboiler duty.

Mirsaidov U.M.   Gafurov B.A.   Mirsaidov I.U.   and Badalov A.   

Thermodynamic characteristics of lanthanides' borohydrides are defined by tensimetric, calorimetric and semiempirical methods. Lanthanides' borohydride crystal energy lattice is defined by compiled Born-Haber cycle and their change regularity within the whole lanthanide's row is determined.

A. Sadki   M.L.Hattali   M. A. Bradai   R. Younes   and N.Mesrati   

This work focuses on the experimental characterization and mechanical behavior modeling of aeronautical alloy based composite to simulate tension test by finite element method and experimental test. The numerical finite element simulation allowed us to understand and manage a number of phenomena encountered during the mechanical behavior of our composites. Tensile tests applied have shown large changes in mechanical properties of the base alloy after coating, which are possibly related to the very different nature of the assembled materials and conditions of application. We note a strong decrease of the elastic limit of AG3 coated compared to AU4G. The high ductility of this alloy is the cause which engenders during the gritting process a large penetration of the granule particles in the substrate and the creation of plastic zones. Thus, a radial compression is exerted on the section which causes a plastification process. The decrease of the average section of the substrate after sandblasting, the stress concentration at the cavity and / or the compressive residual stress created when sandblasting are responsible for the decrease in breaking strength of the AU4G compared to the AG3. The material becomes hard and fragile. The experimental results obtained during our study are consistent with those of the simulation. Indeed, it was noted that the concentration of stresses during the tensile tests was located at the ends of the useful length of the test specimen.

Vanessa Mota Vieira   and Clédola Cássia Oliveira de Tello   

Cementation is a very useful process to solidify radioactive wastes. Depending on the waste it can be necessary to use of chemical additives (admixtures) to improve the cementation process and its product. Admixtures are materials, other than cement, aggregate and water, that are added either before or during the mixing to alter some properties, such as workability, curing temperature range, and setting time. However there are a large variety of these materials that are frequently changed or taken out of the market. In this changeable scenario, it is essential to know the commercially available materials and their characteristics for use in the cementing of radioactive waste. In this research the effects of chemical admixtures in the solidification process has been studied. For the tests, it was prepared a solution simulating the evaporator concentrate waste, cemented by two different formulations, and three chemical admixtures from two manufacturers. The tested admixtures were accelerators, set retarders and superplasticizers. The experiments were organized by a planning factorial 2³ to quantify the effects of formulations, of the admixtures, its quantity and manufacturer in properties of the paste and products. The measured parameters included the density, the viscosity and the setting time of the paste, and the product compressive strength. As future work the leaching test will be performed. The parameter evaluated in this study was the compressive strength for a curing time of 28 days, is considered essential security issues relating to the handling, transport and storage of cemented waste product. The results showed that the addition of accelerators improved the compressive strength of the cemented products.

Wei Ge   Yu Chen   Liang Wang   and Ronghua Zhang   

β-carotene, one of the carotenoids, was photodegraded under visible light irradiation by using pure TiO₂ and M-TiO₂ (M= metal; Ag, Fe, Ru). The photocatalysts were prepared by a sol-gel method and incipient wetness impregnation method, and investigated by means of X-ray diffraction and scanning electron microscopy for characterization. The effects of photocatalyst and oxygen content were investigated, which was based on the absorbance at 450 nm of photodegradation of β-carotene as the main index. The study of photocatalytic activity indicated that Ag-doped TiO₂ showed higher photocatalytic activity than other photocatalysts. And also a quick decrease of β-carotene in the presence of oxygen was observed. β-cyclocitral, 5,6-epoxy-β-ionone and dihydroactinidiolide, the main photocatalytic degradation products of β-carotene were confirmed by gas chromatograph-mass spectrometer (GC-MS) analysis. All these degradation products can be used for fragrance and flavoring agents, such as cigarette flavoring ingredients.

Ravan Mammadov   

The following article deals with the useful, new, creative forms of integrative teaching of Chemistry in secondary schools and Lyceums creating connections between Chemistry and other school subjects. The samples from work experience are given in this article.

Gija Geme   Christina Dobson-Jones   Brittany Hagenhoff   and Scott McKay   

Conversion of biomass to fuel is quickly gaining popularity due to its carbon neutral status and the cost volatility of the traditional fossil fuel resources. Biomass feedstocks, such as switchgrass, require minimal fertilizers, labor, and land management. For sustainable switchgrass production to occur, we must understand environmental effects associated with switchgrass, such as any changes soil is undergoing during the growth of switchgrass. This particular study focuses on concentrations of potassium, phosphorus, and nitrogen in soil. Numerous soil samples were taken from four different species of switchgrass in areas with different amounts of nitrogen fertilization. This study found that there was not an overall trend amongst all the soil and switchgrass plots, however there were some similarities within the individual soils and grasses. The soil samples showed that there tends to be an overall decrease in phosphorus, potassium and nitrogen but some of the soil samples showed an increase in phosphorus, potassium and nitrogen content in 2009. Average nitrogen concentrations observed in soil ranged from 2.11-8.99 g N/kg soil and in switchgrass ranged from 3.38-7.67 g N/kg grass. The amounts of phosphorus in soil ranged from 30.7-179 mg P/kg soil and in switchgrass ranged from 14.5-52.7 g of P/kg grass. The amounts of potassium in soil ranged from 162-337 mg K/kg soil.

Paul Sabila   

A new study reports on the use of low concentrations of metathesis catalysts (~ 0.009 mol. %) in the cross-metathesis of styrene to afford relatively good yields (87%) of trans-stilbene (the cross-metathesis homodimer product). The reaction was carried out under aerobic conditions after 3-5 h reflux. Also, a theoretical prediction of the cross-metathesis product at ultra-low concentrations is presented.

João Brandão   Wenli Wang   and Carolina M. A. Rio   

The O + H₂ reaction is a particular example to alert the importance of a clear definition of the quantum state of an atom when referring to a chemical reaction. In its ground state, O (³P), the oxygen atom reacts with H₂ through an energy barrier with small rate constant. In contrast, when the oxygen atom is in its first excited state, O (¹D), the reaction O + H₂ occurs without energy barrier and the rate constant is seven orders of magnitude higher. The dynamic behaviour of this reaction depends also on the quantum state of the oxygen atom.

Sushil Kumar Sharma   and D. D Agarwal   

A facile, simplistic, highly efficient, environmentally safe, regioselective, controllable and economical method for the bromination of organic compounds using aqueous AlBr₃-Br₂ reagent system.

Eric R. Taylor   

The concept of time travel captures the imagination of scientists and nonscientists alike. Though theoretical mathematical treatment of the issue in the realm of physics has offered potential means, albeit, wormholes requiring some rather strange conditions such as negative energy, what does thermodynamics suggest for the potential of time travel? Examination of the thermodynamic state functions of enthalpy and entropy from the Gibbs free energy relationship suggest that the final enthalpy after travel will be greater than the initial enthalpy before travel. The final entropy after travel will be greater than the initial entropy before travel. Transfer of mass from one multiverse to another would seem to violate various mass energy conservation laws, as well as strictures on the Second Law of Thermodynamics for the originating and a target multiverse.

Viktor F. Vargalyuk   Vladimir A. Polonskyy   Larissa V. Borshchevych   and Oksana V. Demchyshyna   

On the basis of quantum-chemical cluster calculations [Ni^z+ (H₂O) _nL](H₂O)_5-n in the interval z = +2, +1, 0 and n = 0, 1-5 the mechanism of electroreduction of complexes of Ni²⁺ and acrylic acid (HAk) has been proved. It has been demonstrated that the initial reactant is the [Ni²⁺(H₂O)₅Ak^–], the intermediate is the [Ni⁺ (H₂O)₂Ak^–] and the end product exists in various forms among which the most stable is [Ni⁰(H₂O)₂(π-��А��)��.

Shiraz M. Mammadov   Rena F. Khankisiyeva   Jovdat S. Mammadov   Adil A. Garibov   and Revan N. Mehdiyeva   

The increase of irradiation temperature by gamma-rays of emulsion isoprene nitrile elastomer in the range of 298-423 K is accompanied by the significant increase of crosslinking rate and strength deterioration of unfilled cures at the same time. By the method of sol-gel analysis, the output dependences of the mesh chains (1/Mc), cross-linked molecules (1/Mƞt) and crosslinks (nc) for isoprene nitrile elastomer are determined between 298 and 423 K. The influence of acrylonitrile content of elastomer group during the process of irradiation and temperature on density change of curing grid using Fourier spectroscopy is established. It also studied the molecular structure of isoprene nitrile elastomer and unsaturation at irradiation and temperature (423K, 500 kGy).

A. M. Alice Margret   A. Amal Raj   T. Citarasu   and C. Nirmala Louis   

A systematic study has been carried out to explore physico-chemical parameters of drinking water from bore holes and shallow wells in five different stations (sites) of Agasteeswaram and Kalkulam Taluks in Kanyakumari District of South India. Water samples from bore holes and shallow wells in five stations were collected and analyzed for temperature, pH, turbidity, alkalinity, hardness, salinity, fluoride, chloride, total dissolved solids, dissolved oxygen, BOD, electrical conductivity, total nitrogen, nitrate, sulphate, ammonia, phosphate, total phosphorus, sodium, potassium and oxidation & reduction potential. Comparative studies of parameters in different stations and in different Taluks were also carried out. The physico-chemical parameters were analyzed and the results were compared with water quality standards described by WHO. Statistical techniques, calculation of basic statistics, Correlation matrix, Hierarchical Cluster analysis were simultaneously applied to the physico-chemical parameters of water samples taken from in different stations and in different Taluks. The above study will be useful to know the water quality and their fitness for drinking purposes at various stations undertaken. Overall water quality was found satisfactory for drinking purpose without prior treatment.

Purujit N. Gurjar   Aron P. Bercz   Thi N. Nguyen   Anish K. Vadukoot   and Vladislav A. Litosh   

Over expression of cysteine proteases in human body causes neurodegenerative diseases, destruction of cartilage tissue, and bone atrophy, and some of them are implicated in destructive role of malignant tumors and cancer metastasis. Several non-human cysteine proteases play a key role in life cycles of certain foreign invasive organisms. Therefore, inhibition of cysteine proteases represents an important venue for finding potential therapeutic agents against Alzheimer's disease, multiple sclerosis, ischemic stroke, myocardial infarcts, carcinoma progression, as well as some parasital and viral infections. Affinity labeling agents used as inhibitors of cysteine proteases normally bear an electrophilic “warhead”, a reactive group that covalently binds the active site cysteine residue thereby inactivating the enzyme, but achieving both high activity and selectivity remains challenging. We are developing cyclopropene derivatives that show selective binding of thiol residues of cysteine. Several derivatives of cyclopropenes have been synthesized and evaluated as potential cysteine-binding “warheads”. Their stability in aqueous media and reactivity toward cysteine and other amino acid chemical probes was examined. We have found that 1,2-cyclopropene moiety irreversibly binds the thiol group of cysteine, leaving other amino acid residues unaffected, which has the advantage for targeting enzymes expressed in foreign organisms or promoting carcinoma progression.

Rajeev Kumar   

The 'living' species selenide anion Se₂^2-, generated in situ by the reduction of 1,2-bis(bis(4-chlorophenyl)methyl)diselane with sodium borohydride, was treated with various organic halides to afford synthetically important organoselenium compounds including α,ω-diselenoethers and selenides bearing ester functionality, under mild and neutral conditions. These compounds have been characterized analytically with the help of various spectroscopic techniques viz., IR, multinuclear NMR (¹H, ¹³C, ⁷⁷Se) and mass spectrometry.

Ayaana Umar Karim   Yaa Ntiamoa-Baidu   Joseph Addo Ampofo   and Robert Kingsford-Adaboh   

The aim of this study was to assess nitrate, chloride and calcium contamination in hand-dug well water as a result of effluent infiltration from household pit-latrine. The study also compared wet and dry season effluent contamination levels. The results were compared to the natural background levels, Ghana Standard Board (GSB) and World Health Organization (WHO) guideline limits for drinking water. Generally, the result of the study indicated a 100% contamination of water with nitrate (NO₃^-), chloride (Cl^-) and Calcium (Ca²⁺) beyond the natural background of 0.23 mg/l, 7.8 mg/l and 12 mg/l respectively for safe drinking water. In addition, 21.7% and 8.3% of the samples analysed for nitrate and chloride respectively, were contaminated at levels that could pose serious health hazards. This could be attributed to the effluent leachate infiltration from the household pit-latrine through the soil into nearby hand-dug well water. Nitrate cannot be retained by soil and is easily washed out of the soil by percolating water. Sodium chloride, a common ingredient in the diet of most Ghanaians, is a strong electrolyte and passes through the digestive system unchanged. Chloride is therefore used as a measure of the extent of sewage discharge into water bodies. Analysis of variance at 95% confidence interval showed that calcium significantly differed in temporal variation (p = 0.00), chloride significantly differed in spatial variation while nitrate was significantly different in both spatial and temporal variations. It is recommended that the West Akim Municipal Assembly and Ghana Health Service should conduct regular inspections and monitor the construction of pit-latrines in the various households.

Atef M.Amer   Amira A. Ghoneim   Mohamed H. Sherif   and Wael Farouk   

Diamino 3a and 3b derivatives which obtained by Michael reaction were coupled with aldoses in the presence of acetic acid and I2 with stirring at room temperature gave 4, 5 and 6 respectively. Acetylation of compound 4 and 5 gave compound 7 and 8 respectively. Coupling of fructose with 3a and 3b in the presence or not of Con HCl gave compound 9 and 11 respectively. Acetylation of compound 9 with acetic anhydride and Pyridine gave compound 10. Some of the synthesized compounds have been screened as antibacterial and antifungal. The structures of the synthesized compounds have been deduced from their elemental analysis and spectral (IR, 1H-NMR) data.

Viktor I. Korobov   Lina V. Petrenko   and Veronika V. Poltavets   

The influence of phase composition on the anodic behavior of electrolytic zinc-based alloys in alkaline solutions was investigated. The following materials were studied: Zn-Sn alloys consisting solely of Zn and Sn crystallites in a mechanical mixture, Zn-Fe, Zn-Co, and Zn-Ni alloys consisting of both solid solutions and intermetallic compounds. The anodic behavior of low-alloy solid solutions is similar to that of pure Zn. Solid-solution alloys consisting of an-phase had a distinctive feature: the descent of the anode current prior to the complete passivation takes place at more positive potentials compared to pure zinc and its mechanical mixtures. The same sequence of anodic dissolution and passivation of zinc alloys as for the pure zinc anode polarization were observed during anodic polarization of both solid solutions and intermetallic phases of zinc alloys. Alloying led to a change in the thermodynamic and kinetic characteristics of anodic processes. Typical peaks of anodic behavior of Zn and Sn were observed on the voltammetry curves of a broad range of heterogeneous Zn-Sn alloys. Peak currents depended on the alloy composition. The dependence between the alloy phase composition and the corresponding electrochemical behavior can be used in determination of the phase composition.

Prithwiraj Byabartta   

Reaction of [Au₂(dppa)Cl₂] with AgOTf in dichloromethane medium followed ligand addition leads to [Au2(dppa)(RaaiR/)](OTf) [RaaiR/ = p-R-C₆H₄-N=N-C₃H₂-NN-1-R/, (1-3), abbreviated as N,N/-chelator, where N(imidazole) and N(azo) represent N and N/, respectively; R = H (a), Me (b), Cl (c) and R/ = Me (1), CH₂CH₃ (2), CH2Ph (3), OSO₂CF₃ is the triflate anion, dppa is diphenylphosphinoammine ring]. The maximum molecular peak of the corresponding molecule ¬ is observed in the ESI mass spectrum. Ir spectra of the complexes show -C=N- and -N=N- stretching near at 1590 and 1370 cm^-1. The 1H NMR spectral measurements suggest methylene, –CH₂–, in RaaiEt gives a complex AB type multiplet while in RaaiCH₂Ph it shows AB type quartets with coupling constant of av. 6.2 Hz. Considering all the moitie there are a lot of different carbon atoms in the molecule which gives a lot of different peaks in the ¹³C NMR spectrum. In the ¹H-¹H COSY spectrum of the present complexes and contour peaks in the ¹H-¹³C HMQC spectrum in the present complexes, assign the solution structure and stereoretentive transformation in each step.

Desissa Yadata   

Physical environments such as rivers can be affected by the massive movement of chemicals from different human activities through run off system. Therefore the metals concentration can be fluctuated and can exceed level of tolerance and even become toxic. The objective of the work is to determine the concentration of metal ions. Water samples were obtained from two sites located around Teppi town namely Achane River and Shay River. From each river six replicate samples were obtained. The acidified plastic bottles were used for sample collection to avoid fluctuation in acidity because of different environmental factors. The standard solution used for calibration purpose is prepared by mixing the standard solution of Na⁺¹ and K⁺¹ metal ion. After standards are aspirated the concentration of potassium and sodium metal ions has been determined in unknown using flame photometry and Fe⁺² determined by using Uv-visible spectroscopy. The concentration determined is in the range of 0ppm-10ppm. Hence the mean concentration of potassium is 2ppm and 1.33ppm in Achane and Shay River respectively. Concentration of sodium is 2.895ppm and 6.9ppm in Achane and Shay River respectively. Iron is determined to be 1.1ppm and 1.6ppm in Achane and Shay River respectively. The concentration of sodium and iron in Achane River is less than that of Shay River and potassium is higher slightly in Achane than Shay and finally the concentration of sodium in both rivers is greater than that of potassium and iron ion. No significant influence can be stated on health because of such detection; since it can be tolerated and of course improvement is needed.

Atef M. Amer   Amira A. Ghoneim   Mohamed H. Sherif   and Wael Farouk   

A series of novel N-glycoside phenyl pyrazole derivatives 5-9 were synthesized by initial reactions of Acetophenone semicarbazone with phosphorus oxychloride to give 3-phenyl-1H-pyrazole-4-carbaldehyde 2 which was reacted with glucose to give N-glycoside. Some of the synthesized compounds have been screened as antibacterial and antifungal. The structures of the synthesized compounds have been deduced from their elemental analysis and spectral (IR, ¹H-NMR) data.

G V R Sharma   M. Veerraghava Reddy   G. Omprakash   and K. Tatendra Reddy   

The epoxides undergo ring-opening reaction smoothly with various amines in an ionic liquid namely 1-butyl-3-methylimidazolium tetrafluoroborate (bmim BF₄) under mild reaction conditions. All the reactions were carried out at ambient temperature to afford the corresponding β–aminoalcohols in excellent yields. The ionic liquid was recovered and reused in further reactions with very good efficiency.

Badis Bendjemil   Abdelaziz Lankar  Djelloul Messadi  and Dominique Vrel  

Combustion synthesis in electrothermal explosion mode can be regarded as an efficient method to obtain new nanomaterials. Different starting mixtures of magnesium powder with various carbonates (Li₂CO₃, Na₂CO₃, CaCO₃, FeCO₃, (NH₄)₂CO₃) were tried and the self-thermal reactions were carried out under both reactive (air) and neutral atmosphere (argon) with an initial pressure of 10 atm to yield novel nanomaterials. Fe, Co, Ni, Pd, Nd, Ta, Ti, Nb, W and NiO powders were used as catalysts and their synthesis and purification have been optimized. Under the applied conditions the presence of crystalline MgO and NaO₂ in products confirmed by XRD analysis, even for the reaction under neutral atmosphere, points to the deep conversion of carbonates. For producing fibrous products the Na₂CO₃ system proved to be the most promising one. FESEM images show the morphology of the products with some 1-D nanostructures resembling carbon nanotubes and nanosized metal/carbon composite (carbon-encapsulated metal-based iron nanoparticles with a core-shell structure with interesting magnetic properties by combustion was obtained. Different magnetic metals (Fe, Ni, and Co) that can be encapsulated by the carbon shell, graphite layers and nanofibers. After purification procedure, we will only obtain core-shell or graphite layers encapsulated by metal magnetic nanoparticles without impurity like noncoated iron or carbides and amorphous carbon. The characterization techniques include the chemical analysis, HRTEM, XRD and FESEM. The obtained novel pharmacological molecular nanostructure will be injected in the cancer tumor cell (prostate) after sterilization. The nanocontainer will be heated by microwave at the Laboratory Central of Anatomie and Cytology Pathology of the CHU Annaba. The reaction will be observed in the HRTEM.

Kazem Karami   Zohreh Karami Moghadama   and Mahboubeh Hosseini Kharata   

A dimeric NC-palladacycle of 2-phenylaniline was applied in the Suzuki reaction of aryl halides and the Heck reaction of methyl acrylate and styrene with phenylboronic acid. This palladacycle was found to be effective catalyst for the Suzuki and Heck cross-coupling reactions which could be carried out in the undried solvent under air.

Shipra Baluja   and Kapil Bhesaniya   

Some new Schiff bases have been synthesized from 4- amino benzoic acid and their thermal analysis have been carried out by TG technique. TG data of decomposition have been analysed for the kinetic parameters using Freeman-Carroll method. From the observed curves, various kinetic parameters such as order of degradation (n), energy of activation (E), frequency factor (A) and entropy change (∆S) have been evaluated. Further, thermal stability of Schiff bases have been determined, which is found to depend on the type of substituent present in the compounds.

Kolsum Safartalab  Fatemeh Dadashian  and Farzaneh Vahabzadeh  

The main effort of this study was to enhance the enzymatic hydrolysis yields of cotton and viscose waste fibers via fed batch enzymatic hydrolysis. To do so, enzymes fed into slurries at two steps in fed batch mode. Also, the batch mode with the same amount of enzymes was implemented in order to be compared with the fed batch mode. The results showed that the released sugar contents from fed batch hydrolysis of cotton and viscose waste fibers were 29.0 and 32.3 g/l, respectively, but batch process released 25.0 and 30.3 g/l from cotton and viscose waste fibers, respectively, which confirms the increasing effect of fed batch process on the hydrolysis of both waste fibers. In addition, the morphological studies and enzymatic hydrolysis yields from pretreated cotton and untreated viscose waste fibers showed that alkali pretreatment for viscose waste fibers is not necessary, but has significant effect on enzymatic hydrolysis of cotton waste fibers; also, the differences in microcrystalline structures of viscose and cotton waste fibers have resulted in more enzymatic hydrolysis and then fermentation yields of viscose waste fibers. The amount of ethanol produced from cotton and viscose waste fibers were 6.9 and 8.1g/l, respectively.

Moses Wekesa   Md. Jamal Uddin   Pablo Conde   and Preet Singh   

During scheduled shut downs of Kraft evaporator and digester, acid cleaning is required to remove scales that precipitate from chemical species present in liquors. Acid cleaning can affect the base metal of the Kraft equipment leading to significant localized corrosion, which can lead to unexpected failures. Burkeite was deposited on the carbon steel coupons and the x-ray diffractometer pattern of the scale was taken. 20% sulfamic acid solution with 0.5% inhibitor B was found to be effective in scale removal at either 25℃ or 50℃.The rate of scale removal increased by either increasing the temperature or the rate of stirring (flow rate). Also changing the scale morphology was another way of enhancing its removal.

Salameh Azimi   and Mohammadreza Sadeghi Moghaddam  

Synthesis, characterization, spectrophotometric studies of three mercury (II) complexes of 1-(2-ethoxyphenyl)-3-(4-nitrophenyl) triazene (ENT) are reported in this article and it was characterized by means of NMR, FT-IR, UV spectroscopy and CHN analysis, then determination of Hg(II) was performed by spectrophotometric determination using chemo metric techniques and new triazen ligand which was prepared by us. The calibration graphs of individual components were linear in the ranges of 1 -5.25 mg•L^-1. The root means square errors of prediction (RMSEP) were 4.4 х10^-3 The proposed method are simple, fast, inexpensive and do not need to any separation or preparation method.

Ho Soonmin   Anuar Kassim   and Tan Weetee   

In this study, the chemical bath deposition technique was used to produce tin sulfide thin films. The SnS films have been prepared using stannous chloride as a tin ion source and sodium thiosulphate as a sulfur ion source. Ethylenediaminetetraacetic acid disodium salt-2-hydrate was used as complexing agent in the chemical bath deposition process. The crystallographic analysis and film thickness were characterized using X-ray diffraction and profilometer, respectively.There were many deposition parameters which influenced the deposition of SnS films. Each deposition parameter influenced all the others. Based on the experimental results, the thickest films were obtained from a solution of pH 12, deposition time of 3 hours,bath temperature of 50℃, 0.15M of SnCl₂ and 0.5 M of Na₂S₂O₃ solution.

Yongdan Hou   Koichi Jeremiah Aoki   and Jingyuan Chen, Toyohiko Nishiumi   

This paper aims at evaluating the dependence of double-layer capacitance at a platinum wire electrode both on concentrations of four kinds of halide ions and the dc potential in the double-layer region (from 0.0 to 0.4 V vs. Ag|AgCl) from a viewpoint of frequency-dispersion of the capacitance. Attention was paid to shape of the double layer capacitance vs. dc-potential curves. The equivalent circuit used for analysing the double-layer impedance was a parallel combination of a double layer capacitance and an apparent resistance. The latter is caused by the time-derivative of the capacitance, which belongs to an in-phase component. It was inversely proportional to the frequency and the electrode area, but unaffected by the potential and the variation of concentrations of halide ions. On the other hand, the parallel capacitance decreased linearly with logarithm of the frequency, and was proportional to the electrode area. It showed almost a value common to concentrations from 1 mM to 2 M (= mol∙dm^-3) and four halide ions. Variations of the capacitance with the dc-potential in 0.1 M KF, KCl and KBr solutions are ca. 10 %. Therefore, the capacitance has negligible influence on the localization of ions by the Gouy-Chapman theory.

Michael M. Silaev   

Five reaction schemes are suggested for the initiated nonbranched-chain addition of free radicals to the multiple bonds of the unsaturated compounds. The proposed schemes include the reaction competing with chain propagation reactions through a reactive free radical. The chain evolution stage in these schemes involves three or four types of free radicals. One of them is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the suggested schemes, nine rate equations (containing one to three parameters to be determined directly) are deduced using quasi-steady-state treatment. These equations provide good fits for the nonmonotonic (peaking) dependences of the formation rates of the molecular products (1:1 adducts) on the concentration of the unsaturated component in binary systems consisting of a saturated component (hydrocarbon, alcohol, etc.) and an unsaturated component (olefin, allyl alcohol, formaldehyde, or dioxygen). The unsaturated compound in these systems is both a reactant and an autoinhibitor generating low-reactive free radicals. A similar kinetic description is applicable to the nonbranched-chain process of the free-radical hydrogen oxidation, in which the oxygen with the increase of its concentration begins to act as an oxidation autoingibitor (or an antioxidant). The energetics of the key radical-molecule reactions is considered.

Nwadike Isioma   Yahaya Muhammad   O’Donnell Sylvester   Demshemino Innocent   and Okoro Linus   

Biodiesel is a substitute diesel fuel produced from vegetable oils or animal fats by trans-esterification in the presence of a catalyst. Due to its environmental friendliness, its use is becoming necessary in all regions, however, there are problems associated with its fluidity in cold temperatures. This paper examines the cold flow properties as well as the kinematic viscosity of produced biodiesels. The review shows that both properties are affected by the length of the carbon chain and degree of saturation. However, these can be improved by blending either with petro-diesel or less saturated FAME, as well as the use of some additives.

Anastas Dakashev   Stancho Pavlov   and Krasimira Stancheva   

A method of molecular absorption analysis in the visible spectrum has been developed that does not need monochromatic light and measuring the absorbance. Instead, pictures of the test color solution are taken using a digital camera. The digital image data are transferred to a personal computer through a capture card or a cable. Tristimulus values (R, G and B) representing image chromaticity are found. A polynomial regression equation is applied to describe the relation between one of the R, G or B tristimulus values and a concentration of the test solution in order to calculate the unknown concentration. A computer program is specially created to process all necessary operations. Solutions of MnO₄-, Cr₂O₇^2-, Cu²⁺, Fe³⁺ and NH⁴⁺ with low - and high - level concentrations are analyzed with good analytical characteristics.

Mei-Fang Ding Kai-Feng Cheng Ying-Nan Chen and Shaw-Tao Lin 

The electrophilic substitution of 3-aryl-4- phenylsydnones, 3-arylmethylsydnones and 3-phenylethyl- sydnone are studied in order to understand extend of dual nature of the sydnone ring. In the reaction, the nitronium cation is more reactive toward to the aryl ring attached at N(3). The presence of a methyl or methoxyl group on the benzene ring of the arylalkyl group or of methylene between the aryl and the sydnonyl ring causes the phenyl ring to become electrophilic.

Alexey Kharlamov Marina Bondarenko and Ganna Kharlamova 

In contrast to previously known methods of fullerenes and fulleranes producing, firstly the reaction conditions of direct conversion of toluene, xylene and ethanol molecules into molecules of not only fulleranes (C₆₀H₄-C₆₀H₆₀ and C₇₀H₁₀-C₇₀H₄₂), but also into quasi-fulleranes (C_nH_n-6-C_nH_n-2 (n = 20-42)) were created. The substances containing small molecules of carbon C₃-C₁₇ were synthesized from vapors of toluene, xylene and ethanol under the conditions excluding sublimation of carbon. Firstly the volatile products of thermolysis of hydrogenated molecules of carbon are investigated in all an interval of temperatures 50-750℃ by means of mass spectrometric method. It is established, that the evolution of hydrogen from given hydrogenated molecules of carbon with so low (~ 50℃) temperature is starting off. Earlier by anybody yet not synthesized an equiatomic composition fullerane C₆₀H₆₀ was synthesized, the thin structure of its mass spectrum completely coincides with natural isotope distribution in a molecule C₆₀H₆₀. The substances synthesized were characterized by temperature-programmed desorption mass spectrometry, matrix-activated laser desorption/ionization mass spectrometry, IR spectroscopy and chemical analysis.

Barnana Pal and Srinanda Kundu  

The velocity (v) and attenuation constant (α) for ultrasonic waves of frequencies 1MHz and 2MHz propagating through aqueous sodium chloride solution have been measured over the concentration (c) region 0-5.3 mol L^-1 at room temperature (25℃). The velocity (v) shows an overall increase with the increase of concentration indicating comparatively stronger bonding among the ions and water molecules prevailing in the solution. The attenuation constant, besides showing an overall increase with concentration, shows significantly high values at some concentrations. Attempt has been made to understand the behaviour from existing theoretical background.

Zahra Abbasi Mohammad Alikarami  Vahid Moradi  Farzaneh Moradi  and Eshagh Rezaee Nezhad 

The aims of the study were to investigate the effect of Banana peel on adsorption of CO²⁺ and Ni²⁺ by using flame atomic absorption spectroscopy (FAAS) for metal estimation. The effects of CO²⁺ and Ni²⁺ ions concentration, agitation time and temperature on adsorption of heavy metals onto Banana Peel was investigated. The experimental isotherm results were fitted using Langmuir and Freundlich equations. The Langmuir and Freundlich model agrees very well with experimental data. The maximum amounts of CO²⁺ and Ni²⁺⁺ adsorbed (q_m), as evaluated by Langmuir isotherm, were 9.02 mg and 8.91 per gram of powder of Banana peel, respectively. Study concluded that Banana peels, a waste material, have good potential as an adsorbent to remove toxic metals like Co²⁺ and Ni²⁺ from water.

Anatoly I. Kazakov Tatyana N. Rudneva Ludmila S. Kurochkina Valery V. Dubikhin and Nataliya A. Sanina 

The hydrolytic degradation kinetics of a new promising anticancer agent – donor of NO, namely, water-soluble nitrosyl iron complex, [Fe₂(S(CH)₂NH₃)₂(NO)₄]SO₄∙2.5��₂O(1), has been studied by electrochemical and microcalorimetric methods in water-dimethylsulfoxide (DMSO) (1:1) solution. Henry's constant for NO dissolved in water-dimethylsulfoxide (DMSO) (1:1) solution has been measured. The temperature dependence of hydrolytic degradation rate constant of complex 1 has been determined. High enough rates of the hydrolytic degradation of these complexes at high negative entropy of activation can be explained by the low value of activation energy.

A.G. Zakharov 

In the work is investigated the totality of processes when gas filling the pore in solids taking into account the availability of energy fields, which have a decisive influence on the ingress of gas molecules inside the pores. Dependence of filling the pores of the parameters characterizing the energy field is obtained, and shows the presence on it of the extremes, that makes more understandable ways of selecting porous bodies with the desired adsorption capacity in relation to this gas. It is shown that the density of the gas in the pore can be, depending on its radius, smaller and significantly exceeds the density of the gas in the outer scope. Where obtained the isotherms of filling the single pore with gas, taking into account the possibility of condensation in the internal volume, and therefore, having all of the elements, often observed in experimental dependencies. Is studied the influence of the energy field of the pores on the form isotherms filling and parameters of the condensation transition, and shown that it can both facilitate and impede the process of condensation in the pore, i.e. to shift its beginning as in the area of lower and higher external pressures.

M. Abul Kashem Liton A.C. Bhowmick and M. Ashraf Ali 

The MIFs had been applied to a data set of thirty three (33) dioxazole derivatives to generate the 3D-QSAR model at various 3D grid spacing. An excellent cross-validated correlation coefficient q² (0.903) and conventional correlation coefficient r² (0.985) were obtained at a 2.0 Å 3D grid spacing, indicating the statistical significance of this class of compounds. The calculated biological activities showed a high degree of agreement with experimental values.

G. Jency and S. Sutha Kumari 

The electronic band structure, density of states, structural phase transition and super conducting transition temperature of group –IV B element Zirconium (Zr) under normal and high pressure are reported. The normal pressure band structure, density of states and superconducting transition temperature of hcp - Zr agree well with the previous calculations. The high pressure band structure exhibits significant deviations from the normal pressure band structure due to s → d transition. Zirconium undergoes structural phase transition from hexagonal closed packed (hcp) phase to body centered cubic (bcc) phase at 0.32 Mbar. For hcp → bcc transition, our calculated phase transition pressure is good agreement with the experimental result of 0.33Mbar. According to the present calculation, at normal pressure, the superconducting transition of hcp - Zr occurs at 0.53K which is in agreement with the experimental observation of 0.55 K. The density of states at the Fermi level (N(EF)) is decreased as the pressure is further increased, which leads to the increase in the value of Tc (5.807 K at 0.32 Mbar).

Viktoria Krainik and Valentina Ushkalova 

Physiological role of copper complexes includes many functions and a special place occupies participation in lipid oxidation of biological membranes. Chain oxidation of ethyl oleate in micellar solution in the presence of copper (II) complexes with α-alanine as a catalyst were decomposed. The results obtained indicated parallel of formation and decomposition of primary and secondary products in catalytic lipid oxidation. We proposed mechanism of catalytic lipid oxidation, based on the results obtained and well-known kinetic scheme. Possibility of participation of copper (I and II) not only in the decomposition of primary hydroperoxides, but secondary oxidation products such as α, β-unsaturated carbonyl compounds are discussed. Activation energies of formation and decay of lipid peroxidation products were calculated. The results obtained were (71±1) and (58±1) kJ/mol, respectively. The assays described herein are similarity to biological systems.

Michael M. Silaev 

New reaction scheme is suggested for the initiated nonbranched-chain addition of free radicals to the multiple bond of the molecular oxygen. The scheme includes the reaction competing with chain propagation reactions through a reactive free radical. The chain evolution stage in this scheme involves a few of free radicals, one of which (tetraoxyl) is relatively low-reactive and inhibits the chain process by shortening of the kinetic chain length. Based on the proposed scheme rate equations (containing one to three parameters to be determined directly) are deduced using quasi-steady-state treatment. The kinetic description with use the obtained rate equations is applied to the γ-induced nonbranched-chain processes of the free-radical oxidation of liquid o-xylene at 373 K and hydrogen dissolved in water containing different amounts of oxygen at 296 K. In these processes the oxygen with the increase of its concentration begins to act as an oxidation autoingibitor (or an antioxidant), and the rate of peroxide formation as a function of the dissolved oxygen concentration has a maximum. The heat effects are compared for the overall reactions of dissociation of simple alkylperoxyl (exothermic) and alkoxyl (endothermic) free radicals in the gas phase. Possible nonchain pathways of the free-radical oxidation of hydrogen and the routes of ozone decay from the energetic standpoint via the reaction with the hydroxyl free radical in the upper atmosphere (including the addition yielding the hydrotetraoxyl free radical, which can be an intermediate in the sequence of conversions of biologically hazardous UV radiation energy) were examined. The energetics of the key radical-molecule reactions is considered.

Kiran M. Khandarkar Manoj Shanti Mudrika Ahmed and Jyotsna S. Meshram 

An effortless and straight forward approach to new substituted coumarin derivatives via Betti’s condensation reaction of quinoline and chromone based aldehydes has been demonstrated successfully under ambient reaction conditions. Physico-chemical parameters, toxicity profiles, drug likeness were studied using various bioinformatical tools like Petra, Osiris and Molinspiration. Good correlations were found between the predicted binding free energies and the experimental inhibitory activities which suggested that the identified binding conformations of these potential inhibitors are reliable. These results viz. the good correlations between the inhibitory activities and the computational values, makes the molecules available for future protein-ligand interaction studies. It further provided useful information in understanding the structural and chemical features of the drug in designing and finding new potential inhibitors.

O. Shmychkova T. Luk'yanenko and A. Velichenko 

Modified PbO₂ anodes doped with bismuth were prepared by means of electrodeposition in methanesulfonate solutions. The influence of bismuth ions on morphological and electrocatalytic properties of obtained coatings was studied. Both XRD patterns and SEM micrographs demonstrated that incorporation of bismuth diminishes the size of crystal particles. It is shown, that oxygen overpotential on micromodified electrodes is sensibly higher than on non-modified PbO₂-electrode. According to obtained results a hypothesis of a mechanism which include transfer of an increased number oxygen radical intermediates to Bi(III) to produce a sensible amount of Bi(IV) and Bi(V) that can participate in the O₂ evolution process was proposed.

Mohammad Taghi Taghizadeh and Narges Sabouri 

Polyvinyl alcohol (PVA) / starch (S) /Carboxy methyl cellulose (CMC) / Montmorillonite (MMT) bionanocomposite films were prepared from PVA, MMT, CMC and soluble starch aqueous suspensions by casting method in the presence of a plasticizer that contained glycerol. The kinetics of thermal degradation of PVA/S/CMC/MMT blends was investigated by thermogravimetry (TGA) and derivative thermogravimetry (DTG). Experiments under non-isothermal conditions were carried out for samples in nitrogen (the inert atmosphere in order to avoid thermoxidative degradation) at heating rates of 7.5, 10 and 150C/min. The Ozawa method was used to calculate the activation energy of thermal degradation for PVA/S/CMC and PVA/S/CMC/MMT blends. The thermal stability of PVA/S/CMC/MMT blends is higher than that of PVA/S/CMC suggesting that the addition of MMT improved the thermal stability of PVA/S/CMC blend. At least four degradation distinct stages were identified in the PVA/S/CMC/MMT blends by means of using TGA, being assigned to the mass loss due to the plasticizer leaching, and to the degradation of the starch, CMC and PVA fractions.

A. M. Zaky and M. A. Al-Khaldi 

The electrochemical behavior of Cu-Ag system was studied in 0.5 M NaOH and sodium perchlorate by means of cyclic voltammetry, potentiodynamic anodic polarization and current/ time transients techniques. SEM and EDX microanalysis were used to examine the changes caused by the electrochemical perturbations. In perchlorate free alkali solution the anodic portion of the voltammogram was characterized by the existence of two potential regions I and II. In the first potential region copper dissolves preferentially and exhibits three anodic peaks A₁, A₂ and A₃. The anodic peak A₁ was related to the formation of Cu₂O while the anodic peaks A₂ and A₃ are related to the oxidation of Cu and Cu₂O, respectively to CuO and Cu(OH)₂. The preferential dissolution of copper was enhanced and the simultaneous dissolution of silver was retarded on increasing the silver content in the alloy. The potential region II was characterized by the appearance of three anodic peaks A₄, A₅ and A₆ which are related o the formation of mono-layer, and multi-layers of Ag₂O, AgO and Ag₂O₃, respectively. The addition of increasing amounts of ClO₄^- increases the heights of the anodic peaks and above a limiting value breakdown the anodic passivity and initiate pitting corrosion. The pitting potential decreases linearly with ClO₄^- concentration but increases with increasing scan rate. The potentiostatic current time transients show that the pitting corrosion can be described in terms of an instantaneous three dimensional grows under diffusion control. X-ray diffraction analysis was used to determine the composition of the corrosion products on the electrode surface. Scanning electron microscope was used to monitor pitting corrosion and to elucidate the effect of constituents on the alloy dissolution.

A. B. Naik and M. L. Narwade 

The stability constants of 1-phenyl-3-(2-hydroxy-4-methylphenyl)-5-methylpyrazole (PHMPMPz) and their complexes with Pr (III) and Sm (III) metal ions have been determined in 70% v/v dioxane-water media at different ionic strength (0.02, 0.04, 0.06, 0.08, 0.1) mol.dm-3 at 300.15K by pH metry method. The pK and logK values decrease with increase in ionic strength of medium, which indicated the opposite charges on reacting species. The values of stability constants for Sm (III) were greater than Pr (III) metal ion. The thermodynamic stability constants at zero ionic strength have also been determined.

Ayman M. Zaky 

The electrochemical behaviour of two copper-nickel alloys is studied in 0.1 M Na₂SO₄ using cyclic voltammetry, potentiodynamic and current time transient techniques. The microstructure of the compounds formed during anodic sweep is characterized using x-ray diffraction analysis. The forward sweep is characterized by the existence of two well-defined potential regions; the selective dissolution and the simultaneous dissolution potential regions. The first potential region consisted in two anodic peaks A₁ and A₂ corresponding to the formation of Ni(OH)₂ and NiO, and Cu₂O, respectively. The second potential region consisted in two anodic peaks A₃ and A₄ corresponding to the formation of CuO and Ni₂O₃, respectively. It is found that the Cu-Ni system in sulphate solution follows the dissolution-redeposition mechanism of the dissolution of metals from the alloys. The X-ray diffraction analysis confirmed the existence Ni₂O₃ and CuO on the electrode surface of nickel rich alloy polarized to potential more noble than the potential of A₄ and the existence of Cu₂O and NiO on the surface of copper-rich alloy polarized to a potential in the A₂ region. Atomic Force microscope images show surface enlargement beyond the critical potential E_crit.