International Journal of New Chemistry

271-282

Authors: Sheida Hosseini; Hossein Salmani; Hamid Sarlak

Various processes have been presented to sweeten natural gas so far. In this study carbon dioxide solubility in diethyl ethanolamine (DEEA) solvent with and without the presence of calcium carbonate nanoparticles at concentrations of 10, 15 and 20 wt% solvent in the pressure range of 5, 10 and 15 bar and titanium oxide, respectively. At concentrations of 0.05 and 0.1 wt% were measured at ambient temperature. The results show that at constant pressure (10 bar) and without the presence of nanoparticles, the solubility for the concentration of 10 to 15 wt% of the solvent increases from 25.8 v/v* to 42.4 v/v*. Increasing the pressure also increases the solubility. For a constant concentration (15 wt% of the solvent), the solubility increases from 31.6 v/v* to 36.7 v/v* by increasing the pressure from 10 to 15 times. However, increasing the concentration of nanoparticles has little effect on increasing solubility. So that for the constant concentration of solvent (10%) and constant pressure (15 bar) the solubility of carbon dioxide for the nanoparticles increases from 0 to 0.1 wt% from 32.6 v/v* to 36.7 v/v*.

296-302

Authors: Mohammad Norouzi; Ehsan Darouneh; Tahereh Pirhoushyaran

The production of adhesive from sugar cane bagasse was performed in this study. The goal of this investigation was optimization of wallpaper adhesive production from sugar cane bagasse cellulose by experiments which were designed by full factorial method and carried out in a lab scale reactor with variations in reaction condition such as temperature, catalyst and feed concentration. The analysis of the results showed that the amount and quality of produced wallpaper adhesive is related to reaction condition. The investigation results showed that the optimum condition for removal of lignin from sugar cane bagasse is occurred at ammonia solution concentration of 30 percent and temperature of 150 centigrade. Production of water soluble carbohydrate was carried out by hydrolysis of deligninificated sugarcane in sulfuric acid solution at concentrations of 72 up to 68 percent and controlled temperatures from 20 to 25 centigrade. The results of quality investigations showed that the optimum glue formulation is occurred at carbohydrate concentration of 3 percent and borax concentration of 0.2 percent.

318-335

Authors: Patrice Berthod; Jean-Paul Gomis; Synthia Annick Ozouaki Wora

Manganese is a rather abundant element on earth and alloys based on it may be unexpensive. Alloyed with chromium for corrosion resistance and with carbon and a strong carbide-former element Mn can be the base of new metallic materials with interesting properties. In this work it is aimed to try elaborating Mn-based alloys by foundry and, in case of successful results, to explore the obtained microstructures. Two series were considered, a first one of the Mn – 25wt.%Cr basis with increasing amount in carbon, and a second one with addition of both carbon and tantalum addition. These seven alloys were synthesized by high frequency induction melting and their microstructures were examined using electron microscopy. Thermodynamic calculations were carried out to better understand the microstructure formation. Results show that a double-phased matrix composed of two intermetallic compounds was obtained for all alloys, as well as chromium or tantalum carbides as soon as the carbon content was high enough. Cutting was hard and led to microcracks revealing lacks in toughness. The hardness is very high. It is concluded that the elaboration of such alloys by foundry pose some problems which must be solved, but is possible. The high hardness can be interesting for some applications but the toughness is to be improved. Outlooks of this work are the characterization of the corrosion behavior of these alloys and of their mechanical properties.

184-194

Authors: S. Sepehr Uroomiye; Neda Hajizadeh; Helen Aazh

In this research, IR and frontier molecular orbital computations were employed for investigating the influence of B12N12 on the energetic and thermodynamic parameters of TATB. The Computed enthalpy changes and Gibbs free energy variations showed TATB interaction with this nanostructure is exothermic, spontaneous and experimentally possible. The specific heat capacity values (CV) revealed the heat sensitivity of TATB has improved sharply after its interaction with BN nanocage. Some structural features like bandgap, chemical hardness, chemical potential, electrophilicity and maximum transferred charge capacity were also computed and the results indicated that the reactivity, conductance and electrophilicity of TATB enhances substantially after its reaction with B12N12. All of the computation were done by density functional theory in the B3LYP/6-31G(d) level of theory.

220-231

Authors: Mohamed Elbagerma; wafa Hamoda; Ezaldin Ben-Hmida; Howell Edwards

The quality of cement is one of the important factors which materially contribute to the strength and durability of structural concrete. Different brands of Portland cement are used in Libya by local contractors for various construction work. However, no comparative study has been made undertaken hitherto to investigate the mechanical and physical properties of the various brands of cement. This study investigates the fineness, soundness, setting time and compressive strength of Libyan cement manufactured by the national Libda, Al-Koms, Al-mergeb and Al- borg plants and also some imported cements sold in the Libyan market. All brands of cement tested have normal and acceptable consistencies. The soundness values for all the brands tested fall below the maximum allowable value of 10 mm. Fineness values for all the brands tested fall within the standard specification limit (2500 cm2 /g <). Based on the results of compressive strengths alone , all the cements could be acceptable for normal construction work.

247-255

Authors: Kamal Bikash Chakma; Ajoy Kumer; Unesco Chakma; Debashis Howlader; Md. Tawhidul Islam

The Mg(BiO2)2 is the orthorhombic crystal system acting as semiconductor in electric devices. To evaluate electronic band structures, the total density of state (TDOS) and the partial density of state (PDOS), Generalized Gradient Approximation (GGA) based on the Perdew–Burke–Ernzerhof (PBE0) was used for Mg(BiO2)2. The band gap was recorded at 0.959 eV, which is supported by a good semiconductor. The density of states and partial density of states were simulated for evaluating the nature of 5s, 4d for Mg, 6s, 4f, 5d, 6p for Bi and 2s, 2p for O atom for Mg(BiO2)2 to explain the transition of the electron due to hybridization. From the PDOS, it was illustrated that the d orbital of Bi atom responses for conducting the electronic holes.

101-110

Authors: Vahid Amani

The new complex of [H2en][Cu(pydc)2].2H2O (1) (where H2en and pydc are ethylenediammonium and 2,6-pyridinedicarboxylate, respectively) was synthesized by the reaction of a mixture of ethylenediamine (en) and 2,6-pyridinedicarboxylic acid (H2pydc) in a mixture of CH3OH/H2O as solvent. This complex was fully characterized by elemental analysis, IR, UV–Vis spectroscopy as well as single-crystal X-ray diffraction method. The crystallographic analysis revealed that the complex of 1 consists of discrete [Cu(pydc)2]2- anion, two bis(protonated) ethylenediamine cation and two crystal water molecules. In the anionic part of this complex, the copper(II) cation is coordinated by two tridentate pydc anionic ligands through the two oxygen atoms of two carboxylate groups and one nitrogen atom of pyridine ring. Also, in this complex, intermolecular C-H…O, N-H…O and O-H…O hydrogen bonds and the strong π…π interactions between the pyridine rings are effective on the stabilization of the crystal packing.

125-136

Authors: K. Peer Mohamed; A. Maajitha Begam; P KandasamyPrabakar; C. Christobher

Nature has been a wellspring of therapeutic operators for a huge number of years and an exceptional number of present day drugs have been secluded from common sources. Higher plants, as wellsprings of restorative mixes, have kept on assuming a prevailing part in the support of human wellbeing since old circumstances. More than half of all cutting edge clinical medications are of characteristic item starting point and assume a critical part in tranquilize advancement programs in the pharmaceutical business. Blepharis is an Afro-asiatic class including 129 species, having a place with the family Acanthaceae, broadly circulated in bone-dry and semi-dry natural surroundings. A portion of the animal varieties incorporate B. attenuata Napper, Blepharis edulis, B. sindica, and B. maderaspatensis. Blepharis maderaspatensis (L.) Heyne ex Roth is utilized for treatment of various illnesses like dysuria, cerebral pain, and maladies of sensory system, diuretic and love potion. These plants show an extensive variety of pharmacological exercises including cell reinforcement, mitigating, hostile to joint, antimicrobial, antifungal, against ulcer and cytotoxic exercises. Some settled pharmacological exercises of these plants have been talked about in this article. Wide varieties of the plants and their dynamic standards have been assessed for pharmacological properties. The plant species being generally conveyed can be utilized as another option to the customary medications. Subsequently, there is a need to know the plausibility of utilizing removes and bioactive mixes got from such plants for the control of perpetual infections as asserted by customary healers.

150-168

Authors: Mohamed S. Nagar

As part of the development of equipment and innovative technology for the process flow-sheet, a study on the selection of good resin for uranium uptake is ongoing. Both static and dynamic column equilibrium testing upon synthetic and Gattar pregnant leach solutions (PLS) were carried out to estimate the change of total capacity and breakthrough capacity of the commercial macroporous anion exchange resin (D201). Applying the static and dynamic methods upon synthetic uranium sulphate solution, the maximum adsorption capacity of uranium (VI) upon D201 resin was evaluated to be 105 and 101.2mgU/g respectively. The macroporous D201 resin has been found to agree with the Langmuir isotherm. Finally, the optimized factors have been carried out for uranium recovery from Gattar pregnant leach solution, under the optimized working conditions, about 93 and 90 % of the resin theoretical capacity was realized using both static and dynamic techniques respectively.

14-29

Authors: Meaza Dejene; Kassim Kedir; Seblework mekonen; Abera Gure

In this study, the level of selected organophosphorus and organochlorine pesticide residues from water samples of Gilgle Gibe (I) hydroelectric dam reservoir and its potential tributaries, Jimma zone, Ethiopia, was determined by gas chromatography-electron capture detector (GC-ECD). Low density based dispersive liquid-liquid microextraction (LD-DLLME) using toluene (as extractant) and acetonitrile (as disperser) was used for extraction of pesticide residues from the samples. Calibration curves constructed at six concentration points have good linearity with coefficient of determination (r2) ranging from 0.995 - 0.999. The limits of detection (LOD) and quantification (LOQ) of the method which were determined as 3 and 10 times the signal-to-noise ratio were ranging from 0.0001 - 2.5810 µg/L and 0.0005 - 8.6050 µg/L, respectively. The efficiency of the method was also evaluated using recovery studies by spiking the water samples with known concentrations of the analytes. The obtained recoveries were ranging from 67 - 105% with relative standard deviations of 0.79 - 12.5%. The findings revealed that the studied water samples contain significant amount of the target pesticides, but endrin was not detected in any of the water sample. Methidathion was also detected only in Nada Qalla and Nada Gudda river water samples. The detected residual concentrations of the target pesticides were above the maximum residue limits, except DDT in acute toxic level. The finding indicated that the studied water samples contain considerable amount of the studied residual pesticides that can influence the health of aquatic organisms and other consumers.

47-59

Authors: Tesfa Bedassa; Medhanit Desalegne

In this paper, Qeera wastewater containing stream, found in Bakkee-Jamaa district of Nekemte town, was assessed for selected metals and physico-chemical properties. The metals were determined by flame atomic absorption spectrophotometry (FAAS). Additional water samples collected from Dangi spring water, which is found about 10 km far away from the town, and Chalalaqi waste water containing stream were also assessed for reference. Analysis of concentration of Pb, Cd, Cr, Ca, and Ni metals were carried out using FAAS. For metal analysis good linearity were obtained with coefficient of determination (R2) 0.998 or better. The LOD for the metals were in the range of 0.003 to 0.018 mg L−1 and LOQ, 0.010 to 0.06 mg L−1. Recovery studies ranged from 92 % to 104 % for the metals. The study shows that Ca, Cd and Ni are quantified in all the three water bodies. Overall, the level of the metals studied is higher in the urban area streams than that of Dangi spring in the rural area. The average concentrations (in mg/L) of Ca, Cd and Ni were found to be 9.56., 0.22 and 0.38, respectively. When compared with international guide lines for the quality of irrigation water, Cd and Ni are above permissible levels and show significant pollution of the water. The data obtained from the study of selected physico-chemical properties (EC, TDS, pH, TSS and Cl¯) of the water samples were found to be within the recommended level except TSS.

74-86

Authors: Sheila Kumer; Maryam Ebrahimikia; Mohammad Yari

In this study 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) interaction with carbon nanocone(NC) and nanocone Sheet (NCS) was evaluated by density functional theory. The calculated thermodynamic parameters including Gibbs free energy changes and Enthalpy alterations showed the interaction of TATB with the both nanostructures are exothermic, spontaneous, experimentally possible and irreversible. The specific heat capacity values proved the heat sensitivity of TATB decline after its adsorption on the surface of carbon nanocone and nanocone sheet. The effect of temperature on this process was also investigated and the results indicated 300 K is the optimum temperature for the interaction of TATB with the nanostructures. The frontier molecular orbital analysis was also employed and the findings indicated the reactivity and energetic traits of TATB have enhanced significantly after its interaction with carbon nanocone and nanocone sheet. Indeed, both of the nanostructures cause a substantial improvement in energetic features and a tangible decrease in the heat sensitivity.

184-194

Authors: S. Sepehr Uroomiye, Neda Hajizadeh, Helen Aazh

In this research, IR and frontier molecular orbital computations were employed for investigating the influence of B12N12 on the energetic and thermodynamic parameters of TATB. The Computed enthalpy changes and Gibbs free energy variations showed TATB interaction with this nanostructure is exothermic, spontaneous and experimentally possible. The specific heat capacity values (CV) revealed the heat sensitivity of TATB has improved sharply after its interaction with BN nanocage. Some structural features like bandgap, chemical hardness, chemical potential, electrophilicity and maximum transferred charge capacity were also computed and the results indicated that the reactivity, conductance and electrophilicity of TATB enhances substantially after its reaction with B12N12. All of the computation were done by density functional theory in the B3LYP/6-31G(d) level of theory.

220-231

Authors: Mohamed Elbagerma, wafa Hamoda, Ezaldin Ben-Hmida, Howell Edwards

The quality of cement is one of the important factors which materially contribute to the strength and durability of structural concrete. Different brands of Portland cement are used in Libya by local contractors for various construction work. However, no comparative study has been made undertaken hitherto to investigate the mechanical and physical properties of the various brands of cement. This study investigates the fineness, soundness, setting time and compressive strength of Libyan cement manufactured by the national Libda, Al-Koms, Al-mergeb and Al- borg plants and also some imported cements sold in the Libyan market. All brands of cement tested have normal and acceptable consistencies. The soundness values for all the brands tested fall below the maximum allowable value of 10 mm. Fineness values for all the brands tested fall within the standard specification limit (2500 cm2 /g <). Based on the results of compressive strengths alone , all the cements could be acceptable for normal construction work.

247-255

Authors: Kamal Bikash Chakma, Ajoy Kumer , Unesco Chakma, Debashis Howlader, Md. Tawhidul Islam

The Mg(BiO2)2 is the orthorhombic crystal system acting as semiconductor in electric devices. To evaluate electronic band structures, the total density of state (TDOS) and the partial density of state (PDOS), Generalized Gradient Approximation (GGA) based on the Perdew–Burke–Ernzerhof (PBE0) was used for Mg(BiO2)2. The band gap was recorded at 0.959 eV, which is supported by a good semiconductor. The density of states and partial density of states were simulated for evaluating the nature of 5s, 4d for Mg, 6s, 4f, 5d, 6p for Bi and 2s, 2p for O atom for Mg(BiO2)2 to explain the transition of the electron due to hybridization. From the PDOS, it was illustrated that the d orbital of Bi atom responses for conducting the electronic holes.