bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gas chromatographic retention times prediction for components of petroleum condensate fraction
Authors: Moustafa Nagy 
Published: August 2009

AbstractA new and simple quantitative structure-retention relationship (QSRR) was tested as a predictive model for adjusted retention times in complex petroleum condensate fractions. This relationship adopted the form of a non-linear collective retention-variables model. The adjusted retention times were correlated with the components molecular descriptors, e.g. total path counts and boiling temperatures, by multi-linear regression analysis. The obtained two QSRR models show an acceptable predictive accuracy with R 2 of 0.9949 and 0.9856, respectively. Stability and validity of the models were tested by comparing the calculated and the experimental retention indices.
Aqueous foam stabilized by polyoxyethylene dodecyl ether
Authors: Li Xi-An , Peng Jian-Bing , Yan Yong-Li 
Published: August 2009

AbstractFoaming properties of aqueous solutions of the nonionic surfactant polyoxyethylene dodecyl ether (C12EOn) were studied at 298 K. Four different EO chain lengths, namely C12EO3, C12EO5, C12EO7, and C12EO9, were considered. The foams obtained from C12EO3 or C12EO5 were extraordinary stable retaining a constant volume for more than 20 h. The presence of lamellar liquid crystalline phases was mainly responsible for the super-stable aqueous foams.
Characterization of mechanochemically synthesized lead selenide
Authors: Achimovičová Marcela , Daneu Nina , Rečnik Aleksander , Ďurišin Juraj , Peter Baláž , Fabián Martin , Kováč Jaroslav , Šatka Alexander 
Published: August 2009

AbstractMechanochemical synthesis of lead selenide PbSe nanocrystals was performed by high-energy milling of lead and selenium powders in a planetary ball mill. The structure properties of synthesized lead selenide were characterized by XRD analysis that confirmed crystalline nature of PbSe nanocrystals. Calculated average size of PbSe crystallites was 37 nm. The methods of particle size distribution analysis, specific surface area measurement, SEM and TEM were used for the characterization of surface and morphology of PbSe nanocrystals. SEM analysis revealed agglomerates of PbSe particles. However, HRTEM analysis confirmed perfect stoichiometric PbSe cubes with NaCl structure as well. UV-VIS-NIR spectrophotometry was used to confirm the blue shift of the small particles occurring in the powder product obtained by the mechanochemical synthesis.
Corrosion resistance of zinc electrodeposited from acidic and alkaline electrolytes using pulse current
Authors: Zemanová Matilda 
Published: August 2009

AbstractCorrosion resistance of zinc coatings was investigated in an accelerated corrosion test in a condensation chamber. Zinc was electrodeposited from alkaline and acidic electrolytes using direct current (DC) or pulse current (PC). The zinc coating was subsequently protected against corrosion with a chrome (III) layer. Morphology and structure of the coatings was investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD) before and after the corrosion test. Corrosion resistance of alkaline zinc coatings electrodeposited with DC and PC under test conditions was found to be comparable. The corrosion resistance of zinc coatings deposited from acidic electrolytes by PC was lower in comparison with corrosion resistance of zinc coatings deposited using DC.
Reactivation of a palladium catalyst during glucose oxidation by molecular oxygen
Authors: Gogová Zuzana , Hanika Jiří 
Published: August 2009

AbstractKinetic data of glucose oxidation in aqueous solution catalyzed by heterogeneous palladium catalyst are presented under conditions of the catalyst reversible deactivation by oxygen. Measurements were run in a semi-continuous stirred tank reactor at 30°C and atmospheric pressure in kinetic regime. Effect of the reaction mixture composition on the reaction rate is presented. The catalyst activation/reactivation technique is discussed and optimized. Relation between optimal activation time and glucose concentration was defined.
Application of gas chromatography-mass spectrometry in research of traditional Chinese medicine
Authors: Ye Jiesheng 
Published: August 2009

AbstractIt is well known that traditional Chinese medicine (TCM) plays a more and more important role in modern pharmaceutical industry. It has been used in the therapy of many diseases for several thousand years because of its high pharmacological activity, low toxicity and rare side effects. In TCM, as an important group of secondary metabolites, essential oils have attracted a great deal of attention in recent years. Gas chromatography-mass spectrometry (GC-MS) is the most commonly used technique for the analysis of liposoluble constituents, especially volatile/semi-volatile compounds, and their metabolites in biological fluids due to its high resolution, selectivity and sensitivity. This review briefly describes the applications of GC-MS for the isolation and characterization of volatile compounds from TCM. In addition, GC-MS methods adopted in the metabolic profiling of volatile compounds in biological matrices are also described.
Investigation of DNA cleavage activities of new oxime-type ligand complexes and molecular modeling of complex-DNA interactions
Authors: Colak Ahmet , Cekirge Ender , Karaböcek Serdar , Küçükdumlu Aslıgül , Ertunga Nagihan , Col Melek , Abbasoğlu Rza 
Published: August 2009

AbstractNucleolytic activities of some new oxime-type ligand complexes were investigated by neutral agarose gel electrophoresis. Analysis of the cleavage products in agarose gel indicated that all complexes used converted supercoiled pUC18 plasmid DNA to its nicked or linear form. It was found that nucleolytic activities of the complexes depend on the complex concentration, reaction time and the presence of a cooxidant (magnesium monoperoxyphthalate, MMPP) in the reaction mixture. However, the complexes cleaved pUC18 plasmid DNA at all investigated pH values. Nucleolytic activities of complexes were investigated for different complex concentrations (0.1–100 μmol L−1), pH values (6.0–10.0) and reaction times (0–60 min). Molecular modeling studies performed by the Hyperchem Software together with DNA-binding studies showed that planar sites of the complexes intercalated into double stranded DNA. It can be concluded that all oxime-type ligand complexes used can be evaluated as nuclease mimics.
Hydroxyapatite modified with silica used for sorption of copper(II)
Authors: Bogya Erzsébet-Sára , Barabás Réka , Csavdári Alexandra , Dejeu Valentina , Bâldea Ioan 
Published: August 2009

AbstractThis paper aims to increase the sorption capacity of hydroxyapatite and to find the best apatite-based material for metal ions sorption. The sorption process of copper ions from water solutions by HAP and structurally modified HAP was carried out in this work. Structural modifications of HAP were realized in the preparation phase by an addition of sodium silica into the reaction medium. The prepared materials were characterized by physical-chemical methods: IR, electron-microscopy and X-ray diffraction. The composites characterized were tested in kinetic studies regarding ion exchange and adsorption of Cu2+. It was revealed that the silica content, particle size and initial copper ion concentration influence the process rate.
Comparative DFT study on the α-glycosidic bond in reactive species of galactosyl diphosphates
Authors: Kóňa Juraj , Tvaroška Igor 
Published: August 2009

AbstractCorrect prediction of the structure and energetics along the reaction pathway of the formation or dissociation of the glycosidic bond in sugar phosphates is crucial for the understanding of catalytic mechanism and for the determination of transition state structures of sugar-phosphate processing enzymes. The performance of seven density functional theory (DFT) methods (BLYP, B3LYP, MPW1PW91, MPW1K, MPWB1K, M05 and M05-2X) and two wave function methods (HF and MP2) was tested using four structural models with the activated sugar-phosphate α-glycosidic linkage. The models were chosen based on the crystal structure of the retaining glycosyltransferase LgtC complex with methyl α-d-galactopyranose diphosphate and its 2-fluoro derivative. Results of the MP2 method were used as a benchmark for the other methods. Two structural trends were observed in the calculations: predicted length of the activated C1-O1 glycosidic bond of 1.49–1.63 Å was significantly larger than values of a standard C1-O1 glycosidic bond in crystal structures of carbohydrates (1.39–1.48 Å), and the calculated value depended on the DFT method used. The MPW1K, M05 and M05-2X functionals provided results in closest agreement with those from the MP2 method, the difference being less than 0.02 Å in the calculated glycosidic bond lengths. On the contrary, the BLYP and B3LYP functionals failed to predict sugar diphosphate in the (-sc) conformation as a stable structure. Instead, the only stationary points localized along the C1-O1 dissociation coordinate were oxocarbenium ions at the distance of approximately 2.8 Å. The M05-2X, MPW1K and MPWB1K functionals gave the most reasonable prediction of the thermochemical kinetic parameters, where the formation of the oxocarbenium ion has a slightly endothermic character (0.4–1.7 kJ mol−1) with an activation barrier of 7.9–9.2 kJ mol−1.
Clean fuel-oriented investigation of thiophene oxidation by hydrogen peroxide using polyoxometalate as catalyst
Authors: Zhang Gao , Wang Rui , Yu Feng , Zhao Hai 
Published: August 2009

AbstractAfter catalyst screening for oxidative desulfurization of fuel oil within several polyoxometalates, H3PW6Mo6O40 was confirmed for the first time to be an effective and recoverable catalyst for the oxidative removal of thiophene, being also effective for the desulfurization of real diesel and gasoline.
Non-timber forest products from community forestry practices, problems and prospects for livelihood strategy in Jumla
Authors: Paudel Mohan 
Published: August 2009

Jumla is highly rich in its vast and valuable Non-Timber Forest Products (NTFP) including different kinds of valuable medicinal and aromatic plants. However, in recent years, a significant decrease in availability of commercially traded NTFP species has been experienced. Nevertheless, some important initiatives have also been started to manage NTFPs in a sustainable basis. Community Forestry (CF) is one of these. This study aims to suggest practical and sustainable NTFPs management approach in Jumla analyzing existing roles in livelihood strategy. Study covers CFUGs in Eastern part of the district comprising about 70% CF area and contributes more than 60% of exported NTFPs. PRA and RRA tools were used for data collection in the field. NTFPs were found an integral part of the livelihood strategy in the district. More than 90% food deficit people (57%) were having income from NTFPs as a second source of food arrangement to sustain their livelihood. The average annual income from NTFPs per HH was 18,565. No significant correlation was observed between different social groups and income from NTFPs. But, male were found mostly involved in NTFPs collection comparing female. Beside some promising efforts towards control harvesting of NTFPs, no significant impact of CF was observed. Awareness level of the users and governance aspect of CFUGs were found very poor. There was huge gap between management objectives and management prescriptions of most of the community forests. Key words: NTFPs, Livelihood, management, CFUGs doi: 10.3126/banko.v17i2.2155 Banko Janakari, Vol. 17, No. 2, 45-54
Potential role of sacred grove of Lumbini in biodiversity conservation in Nepal
Authors: Bhattarai Khem Raj , Baral Sushim R 
Published: August 2009

This study was conducted in the sacred grove of Lumbini to elucidate its potential role in biodiversity conservation in Nepal. Lumbini Development Trust enumerated tree species of the grove. We have assessed taxonomic validity by identifying the species. A total of 65 tree species, 39 are indigenous to Nepal, were found in the grove. Most of the species were tropical/subtropical elements that are found to be distributed in Nepal from 100 to 2400m asl. Among total indigenous trees, 64 % trees have their distribution in the whole Nepal, whereas 19 %, 14 % and 3 % are limited to central, eastern, and both central and western part of Nepal respectively. The indigenous species found in the grove accounts for 11 % of total tree diversity of Nepal. Of these tree species, five are of threatened, vulnerable and endangered categories. The forest formation of the grove conforms to Dalbergia sisoo-Acacia catechu type's forest of Nepal. However, majority of the trees in the grove were produced by plantation so it has contributed to ex-situ conservation of trees, and hence this reflects the importance of sacred grove. Key words: conservation, distribution, indigenous trees, Lumbini, Sacred grove, sacred plants, tree species. doi: 10.3126/banko.v18i1.2163 Banko Janakari, Vol. 18, No. 1, 25-31
Simple coppice management options for the sal (<i>Shorea robusta</i> Gaertn. f.) forests in the Terai of Nepal
Authors: Ojha SK , Acharya KP , Acharya B , Regmi R 
Published: August 2009

The paper examines simple coppice management options for sal (Shorea robusta Gaertn. f.) forest that maximizes total biomass production. The study is based on the data obtained from two non-replicated research blocks located at Butwal and Dharan, which were established in 1988 and 1989 respectively by the Department of Forest Research and Survey. Out of four blocks in each site, one block was of simple coppice management option. Simple coppice management option had four treatments, i.e. 1) 3 s/s, 2) 1 s/s, 3) 3-2-1 s/s, and 4) Control, which were designed for fodder and fuelwood production in a short rotation of four years. The analysis was done to estimate the productivity of the treatments for the four successive rotations. In on average, it was found that treatment 3- 2-1 s/s was the best to produce maximum biomass in short rotations. Both treatments 1 s/s and 3-2-1 s/s were found best for foliage production. Local community user groups benefit from the result to choose appropriate simple coppice management option in their sal forests, if fodder and fuelwood production in short rotations is the main objectives of the forest management. Key words: biomass, coppice, Nepal, regeneration, Sal forests. doi: 10.3126/banko.v18i1.2164 Banko Janakari, Vol. 18, No. 1, 32-41
Community forest management practices in far-western lowlands of Nepal
Authors: Shrestha B 
Published: August 2009

Wider discussions are held as to the contribution of community forestry program in Nepal to improve the forest condition and meeting the forest product requirements. This paper presents findings from a study of six Community Forest User Groups in far-western lowlands of Kailali and Kanchanpur in Nepal. The groups with natural and plantation forests have varied experiences in forest conservation and distribution of products. Some groups are resourceful in terms of availability of forest products from the natural forests. Others with plantation forests are product scarce from their own and depend on government managed forest and other sources to meet their demands. The role of concerned government authorities and federation of groups would be instrumental to analyse demand and supply, and make provisions for distribution of forest products within and outside groups and district. Key words: Community forest management, forest products, distribution, far-western low land doi: 10.3126/banko.v18i2.2170 Banko Janakari, Vol. 18, No. 2, 25-34
Medicinal plants of Nepal: Distribution pattern along an elevational gradient and effectiveness of existing protected areas for their conservation
Authors: Acharya KP , Chaudhary RP , Vetaas OR 
Published: August 2009

This study explores patterns of medicinal plant species richness along an elevational gradient in Nepal and the effectiveness of existing protected areas for their conservation. We used published data on the distribution of medicinal plants. The number of medicinal plants and the number of protected areas present in each 100 m elevation band were collated by interpolation. We tested the number of protected areas and the number of species as the response variables against elevation as a predictor variable. To explain the relationship between the total medicinal plant richness and their different life forms with elevation and protected areas, we used generalized additive models (GAMs) and scatter plots. The elevational distribution of medicinal plants as a whole and disaggregated into different life forms revealed hump-shaped patterns. The maximum richness of medicinal plants was found at an elevation of 1100 m a.s.l. but the maximum numbers of protected areas were found at elevations between 3000-3500 m a.s.l. There was negative correlation between the altitudinal distribution of protected areas and medicinal plants in Nepal. This study suggests that the protected areas of Nepal were less concentrated where medicinal plants diversity was rich. Key words: Elevation gradient, generalized additive model, medicinal plants, species richness doi: 10.3126/banko.v19i1.2178 Banko Janakari, Vol. 19, No. 1, 16-22
Depredation and deteriorating condition of <i>Shorea robusta</i> and <i>Terminalia alata</i> in Bardia National Park: an imperative to address park biodiversity sustainably
Authors: Acharya GR , Bhatta B , Gyawali AR 
Published: August 2009

The paradigm shift in park management from a fortress mentality to the participatory concept is represented as a major transformation in the conservation discourse in Nepal. The involvement of local people in the management of resources in national parks has been significantly effective in attaining the conservation goals of conserving wildlife without compromising the basic forest resource needs of the local people. Nevertheless, some economically important species have not been afforded due consideration during such management. This study investigates the species composition and regeneration status of Shorea robusta (Sal) and Terminalia alata (Saj) in 4 Buffer Zone community Forests of Bardia National Park in Thakurdwara VDC in 1999/2000, 2002/2003 and 2005. The results reveal that Shorea robusta (Sal) and Terminalia alata (Saj) both constituted a large proportion of species diversity but that their regeneration from seedlings to established stages were low, suggesting vulnerability of this forest and their sustainability at risk due to their dwindling conditions. Immediate management concern of these economically important forest tree species is warranted. Keywords: Biodiversity, national park, shorea robusta, sustainability, terminalia alata doi: 10.3126/banko.v19i1.2181Banko Janakari, Vol. 19, No. 1, 37-40
Synthesis and Characterization of Ferroferriborate (Fe3BO5) Nanorods
Authors: Liu Yi , Peng Sheng , Ding Yong , Rong Chuanbing , Kim Jaemin , Liu J. Ping , Wang Zhong Lin , Sun Shouheng 
Published: August 2009

AbstractFe3BO5 nanorods with diameters from 4 nm to 16 nm and length from 43 nm to 60 nm are synthesized by a facile thermal decomposition of iron acetylacetonate and t‐butylamine borane (TBAB). TBAB is used to control the 1D growth and the aspect ratio of the nanorods. These Fe3BO5 nanorods are antiferromagnetic with TN = 174 K, which is higher than that of bulk Fe3BO5 (114 K).
Highly Selective Cobalt‐Catalyzed Hydrovinylation of Styrene
Authors: Grutters Michiel M. P. , van der Vlugt Jarl Ivar , Pei Yuxin , Mills Allison M. , Lutz Martin , Spek Anthony L. , Müller Christian , Moberg Christina , Vogt Dieter 
Published: August 2009

AbstractPhosphine complexes of cobalt halide salts activated by diethylaluminum chloride are shown to yield highly active catalysts in the hydrovinylation of styrene, with unprecedented high selectivity to the desired product 3‐phenyl‐1‐butene (3P1B). Double‐bond isomerization, a common problem in codimerization reactions, only occurs after full conversion with these catalyst systems, even at elevated temperature. The most active catalysts are based on cobalt halide species combined with either C1‐ or C2‐bridged diphosphines, heterodonor P,N or P,O ligands, flexible bidentate phosphine ligands or monodentate phosphine ligands. Kinetic investigations show an order >1 in catalyst, which indicates either the involvement of dinuclear species in the catalytic cycle or partial catalyst decomposition via a bimolecular pathway.
A depth filtration model of straining within the void networks of stainless steel filters
Authors: Price John C. , Matthews Graham Peter , Quinlan Kevin , Sexton John , de G. Matthews Alexander G. 
Published: August 2009

AbstractA depth filtration model has been developed, based on the three‐dimensional void network model Pore‐Cor. The geometry of the void network is fitted, by means of an eight‐dimensional Boltzmann annealed amoeboid simplex, to the porosity and percolation characteristics of stainless steel sintered filters measured by mercury porosimetry. Preferential and critical flow paths through the network are calculated. Particles from an experimental size distribution are fed along these flow‐biased paths, and when straining occurs, the flow paths are re‐calculated. We show that the model usefully reproduces experimental filtration efficiencies as a function of pressure drop, measured by single pass tests. We also offer a critique of current measurements of filtration efficiency, suggesting the use of a new “alpha efficiency” rather than the standard beta efficiency. The model is currently being adapted to accept porometry as well as porosimetry data, hence avoiding the use of mercury. © 2009 American Institute of Chemical Engineers AIChE J, 2009
Impact of deposit ageing on thermal fouling: Lumped parameter model
Authors: Ishiyama Edward. M. , Coletti Francesco , Macchietto Sandro , Paterson W.R. , Wilson D. I. 
Published: August 2009

AbstractThe thermal and hydraulic performance of heat exchangers can be seriously impaired by the formation of fouling deposits on the heat transfer surfaces. The thermal effect of fouling can be complicated when the deposit is subject to ageing, represented here as a change in deposit thermal conductivity (but not thickness) over time. In this article, we revisit the ageing concept for crude oil fouling proposed by Nelson (Refiner Nat Gas Manufacturer. 1934;13:271–276, 292–298), using a numerical model incorporating first order kinetics to generate quantitative comparisons of different ageing rates. Results are reported for lumped parameter systems (which also simulate point measurement methods commonly used in laboratory testing) that demonstrate that ageing can have a substantial influence on the rate of heat transfer and hence on the surface temperature and rate of fouling. Rapid ageing (compared with the rate of deposition) does not pose problems, but slow ageing, or the use of constant heat fluxes in experiments, can lead to modified thermal fouling behavior. It is concluded that deposit ageing dynamics should be considered alongside deposition rate dynamics when interpreting experimental fouling data and when modeling fouling behavior in support of heat exchanger design or operation. © 2009 American Institute of Chemical Engineers AIChE J, 2010
Relationship between the size of mist droplets and ethanol condensation efficiency at ultrasonic atomization on ethanol–water mixtures
Authors: Kobara Hitomi , Tamiya Makiko , Wakisaka Akihiro , Fukazu Tetsuo , Matsuura Kazuo 
Published: August 2009

AbstractHigh‐frequency (2.4 MHz) ultrasonic irradiation to an ethanol–water mixture can induce the generation of ethanol‐rich mist droplets at lower temperatures. Two groups of droplets in micrometer‐ and nanometer‐sized were observed in the mist generated by the ultrasonic atomization. Nanosized droplets were considered to be ethanol‐rich droplets which cause ethanol condensation. © 2009 American Institute of Chemical Engineers AIChE J, 2010