bluuebunny/crossref_metadata_2025_split huggingface dataset:
Handoff optimization and load balancing in wireless LANs using association control
Authors: Sun Quan , Huang Liusheng , Zhang Haoran , Xu Hongli 
Published: November 2013

SummaryAs users move around in wireless local area networks, they associate with different access points in succession to maintain connectivity. Without the carefully designed association control policy, it may lead to frequent handoffs and imbalanced load, which can potentially incur unacceptable delays and poor throughput. While existing works to this issue mainly focus on minimizing the number of handoffs over time, in this paper, we propose a new association control scheme with the goal of reducing the frequency of handoffs and balancing load among access points. The defined problem, handoff optimization and load balancing (HOLB,) is mathematically described as a minimum–maximum programming. Since the HOLB problem is a nondeterministic polynomial‐time hard, two constant approximation algorithms are presented to resolve it. First, we propose an α‐approximation() centralized algorithm CHOLB. CHOLB employs a novel method to simplify the original problem to the minimum‐cost maximum‐flow problem, which is solved in polynomial time. On the sis of CHOLB, we then put forward a β‐approximation () distributed algorithm DHOLB for the purpose of scalability and lightweight. DHOLB partitions the network into clusters and uses CHOLB as its local centralized algorithm within each cluster. Extensive evaluations show that the proposed algorithms outperform the existing schemes in terms of the handoff frequency and traffic load. Copyright © 2013 John Wiley & Sons, Ltd.
The Challenge of Environmental Governance In The Network Society: The Case of The Baltic Sea
Authors: Tynkkynen Nina 
Published: November 2013

ABSTRACTThe Baltic Sea region has in recent years become known as a pioneer of new modes of governance, reflecting the dynamic development of the network society. At the same time, the Baltic Sea is considered one of the world's most polluted seas, especially in terms of eutrophication, the accelerated enrichment of nutrients in the water. Overall, there is a contrast between the formally successful governance system and the actual state of the Baltic Sea. This paper describes the existing Baltic Sea environmental governance system, from the regional regime to non‐governmental actors, noting that highly institutionalized inter‐state and transnational environmental cooperation adds a greater element of hierarchy for environmental governance in the region. Supporting democratic development is a special requirement for governance in the post‐Cold War context. The paper explicates governance challenges posed by the emerging network society, on the one hand, and the problem of eutrophication, on the other, and makes suggestions on how to develop the governance system in order to meet the challenges. As a conclusion, a general lesson for the management of international water bodies is given. Institutional diversity with many different scale preoccupations is key, but so is the need for leaders to overcome the challenges of polycentric governance: that is, to reduce opacity of governing and to increase the power of stakeholders to define the problem and its solutions in the first place. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Responsible Procurement, Complex Product Chains and the Integration of Vertical and Horizontal Governance
Authors: Boström Magnus , Karlsson Mikael 
Published: November 2013

ABSTRACTThe management of environmental and health risks associated with products from global product chains is a pressing task for contemporary society, a task that involves public and private actors and poses great governance challenges. This article explores how governance arrangements relate to these challenges by focusing on how public and private procuring organizations interpret, use, develop and combine mandatory and voluntary policy instruments. This is theorized in terms of responsible governance of transnational supply chains (RGSC) as well as regarding the combination of vertical and horizontal governance (VG and HG). The article focuses on chemical risks in the textile sector, and is based on findings from case studies of Swedish public and private procuring organizations, with additional interviews with actors engaged in developing various policy instruments. The article shows how mandatory and voluntary policy instruments can – in various ways and combinations – assist in chemical risk management, but also highlights the existence of considerable limitations and gaps, which users need to develop a reflective awareness about. The article reveals different conditions for public and private procurers, and the conclusion includes suggestions on how to bridge the gap between private and public actors. Finally, we conclude by emphasizing that combinations of HG and VG arrangements promote constructive and feasible pathways towards RGSC, but which needs reflective and constructive efforts among actors with insight, willingness and capabilities to create governance linkages. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.
Michael Reaction with Nitroform and Related Syntheses
Authors: Strumza J. , Altschuler Shaloma 
Published: November 2013

AbstractMichael reactions have been carried out between nitroform (trinitromethane) and fourteen acceptors; the reactions do not require external catalysts.Of special practical interest are the Michael adducts of the acrylates of nitroalcohols and nitrodiols.1,2‐Dibenzoylethyleneand 1,4‐naphthoquinone add nitroform normally, but the adducts spontaneously lose nitrous acid, so that formally dinitromethyl substitution takes place. Mononitroalkanes add normally to these two 2,3‐unsaturated 1,4‐diketones.
The Determination of Microgram Quantities of Indium in High Purity Uranium
Authors: Schoenfeld Irena 
Published: November 2013

AbstractMicrogram quantities of indium were separated from uranium by ion exchange as an anionic complex in hydrochloric acid. The completeness of the separation was established using In114 as tracer. Indium in the water eluate was determined spectrographically by DC‐arc excitation. The coefficient of variation for a single determination is about 25%;the absolute limit of detection 0.01μg of indium.
Kinetic Studies on the Methylation of Thiopurines
Authors: Bergmann F. , Kleiner M. 
Published: November 2013

AbstractBoth 6‐mercaptopurine and 6‐thioxanthine, when treated with methyl iodide in dimethylformamide, undergo a two‐step reaction, i.e. first methylation at the sulphur atom, followed by alkylation at N‐3. Reaction; at the sulphur atom of 3‐methyl‐6‐purinethione proceeds 1350 times faster than in 6‐mercaptopurine.
Synthesis of Compounds Related to Steroids. Reactions of β‐Methyltricarballylic Acid Anhydride with Benzene and Naphthalene
Authors: Harnik M. 
Published: November 2013

Abstractβ‐Methyltricarballylic acid anhydride (I) undergoes an efficient three‐step reaction sequence whereby it is transformed into known intermediates useful in the synthesis of aromatic steroids. Experiments are described in the benzene series leading to the preparation of the tetralone derivative (VIIa), and in the naphthalene series giving the tetrahydrophenanthrene acids (XV) and (XIII).
The Synthesis of Some Mercurial Derivatives of Simple Sugars
Authors: Leftin J. H. , Lichtin N. N. 
Published: November 2013

AbstractA number of organomercurials have been produced by oxymercuration of 3,4,6‐tri‐O‐acetyl‐D‐glucal and 2,3,4,6‐tetra‐O‐acetyl‐2‐hydroxy‐D‐glucal followed by replacement of mercury‐bound acetate with a variety of ions. Data collected in connection with investigating the structure of one of the products suggest that reductive demercuration by NaBH4 may proceed with retention of configuration of the mercury‐bound carbon atom.
Total Synthesis of 3,6‐Dimethoxy‐17β‐Acetyl‐1,3,5(10),6,8‐Estrapentaene
Authors: Harnik M. , Jensen E. V. 
Published: November 2013

AbstractA Friedel‐Crafts reaction of 2,8‐dimethoxynaphthalene with β‐methyltricarballylic acid anhydride (I) gave the ketoacid (IId), which upon catalytic hydrogenation and cyclization with hydrogen fluoride afforded the tricyclic ketone (V). Addition of methyl acrylate yielded the tetracyclic ester (VI), which was dehydrated and then decarboxylated at carbon 15. The reactions could be controlled to produce either the 17α‐ or the 17β epimers (IX) and (X). Their hydrogenation furnished the 14β, 17α‐ and 14α, 17β isomers (XII) and (XIb), respectively. The latter was transformed into the 17β‐acetyl derivative (XIe).
Kinetics of the Nucleophilic Substitution Reaction Between 2,4‐Dinitrochlorobenzene and Azide Ions
Authors: Patai S. , Gotshal Y. 
Published: November 2013

AbstractThe reaction between azide ions and 2,4‐dinitrochlorobenzene was found to be of first order in each of the reactants. The reaction is slower in more polar media, and is completely inhibited by acid. The place of azide ions in the nucleophilicity order of aromatic substituting agents is assigned.
On the Nature of the Cation‐Insensitive Bonds of Myelin
Authors: Wolman M. , Wiener H. , Bubis J.J. 
Published: November 2013

AbstractHalf the lipids of myelin which belong to the cation‐insensitive complexes (i. e. 25% of the total lipids) are sensitive to anions and can be extracted by water after treatment with KCNS or Kl. Thin layer chromatography findings indicate that the cation‐insensitive complexes do not differ in lipid‐composition from the cation‐sensitive complexes. Histochemical findings indicate that the highly lyotropic anions inhibit the same enzymatic activities as the feebly lyotropic cation Ca.The implications of these findings on the structure of myelin and of cell membranes is discussed. The data are considered to fit best the concept of a plasma membrane in which one surface contains mainly anionic fixed groups and the other surface cationic groups.
Effect of Sugars on the Stimulus‐Response‐Recovery Cycle
Authors: Dikstein S. , Hamburger A. D. , Tal E. , Sulman F. G. 
Published: November 2013

Abstract(Some, but not all, monosaccharides evoke a “Stimulus” which elicits, a. melanophore reaction; b. contraction of the normal rat ileal smooth muscle and c. contraction of the potassium depolarised rat ileal smooth muscle. Oleate, palmitate. aspartate, glutamate and Krebs cycle intermediates are not stimulants. We propose a working hypothesis, according to which the stimulatory effect of sugars mediates an increased supply of ADP, whilst simultaneously decreasing the glycolysis and thus the supply of cell membrane NADH.
The Direct Determination of Copper and Lead in the HCl Soluble Fraction of Carbonate Rocks
Authors: Yaalon D. H. , Avinur P. , Lipetz‐Herman V. , Barzily I. 
Published: November 2013

AbstractThe U. V. spectra of the chloro‐complexes of copper (I) and lead (II) were studied in various concentrations of calcium and magnesium chloride. Algebraic formulae were developed for the simultaneous and direct determination of trace amounts of copper and lead in the HCl soluble fraction of carbonate rocks. Interference due to background absorbance was reduced by the use of these formulae.
A New Organic Reagent for the Specific Determination of Vanadic Acid
Authors: Ben‐Dor L. , Jungreis E. , Jungreis C. 
Published: November 2013

AbstractThe Schiff base formed from salicylaldehyde and anthranilic acid has been found to be a specific and sensitive reagent for the spectrophotometric determination of vanadium (V). This reagent forms a violet ester with vanadic acid (at pH = 1) extractable with benzene. The determination can be carried out in the presence of many diverse ions, and all but ferric ions do not interfere. Phosphoric acid is used both for masking the iron III and to make the extraction easier. The limit of identification is 10 μg vanadate/1 ml.
Gravimetric Determination of Gold in Alloys
Authors: Avinur P. 
Published: November 2013

AbstractA method is presented for the gravimetric determination of gold in alloys. Based on a known procedure used in metallurgy, it involves the separation of gold from the other elements constituting the alloy, by the aid of the “parting process”, suitably modified. It involves a relatively simple technique with a high degree of accuracy. Gold was successfully determined in the presence of the following metals: Ag, Cd, Cu, Cr, Fe, Mn, Ni, Pd, Sn, Zn.Platinum seriously interferes with the analysis.
6‐Trifluoromethyltryptamines
Authors: Kalir A. , Pelah Z. , Balderman D. 
Published: November 2013

AbstractA series of 6‐trifluoromethyltryptamines has been prepared from 6‐trifluoromethylindole as the starting material. Conversion of the CF3 group to CH3 was observed during the reduction of some of these compounds with lithium aluminum hydride.
Turbidimetric Assay for Pectinase Activity
Authors: Avigad G. , Milner Y. 
Published: November 2013

AbstractA simple procedure for the estimation of polygalacturonic acid and polymethyl‐galacturonic acid hydrolases is described. The method is based on measuring the residual turbidity formed by complexing the acid polysaccharide with quaternary‐ammonium detergents such as cetyl pyridinium bromide. The assay is carried out at pH 4.5 to 5.0 which is optimal for the hydrolase activities.
The Reactions of Aliphatic Aldehydes with Benzamide
Authors: Giger R. , Ben‐Ishai D. 
Published: November 2013

AbstractIsobutyraldehyde, propionaldehyde and acetaldehyde have been found to react with benzamide in the presence of napthalenesulfonic acid to give an enamide, two dimeric enamides and a probably polymeric mixture, respectively. The same products were also obtained from the corresponding alkylidenebisbenzamides (I) under acidic conditions.
The Effect of Sodium Chloride on Catechol Oxidase from Apples
Authors: Sharon Miriam , Mayer A. M. 
Published: November 2013

AbstractCatechol oxidase from apple chloroplasts and browning of apple slices are strongly inhibited by the chloride anion. The inhibition is non‐competitive and reversible. Inhibition is pH‐dependent. being observed at pH 5.1 but not at pH 7.3. Activity could be extracted from the particles using CTAB. The extract's activity at the two pH could not be resolved into distinct fractions. The pH‐dependence of inhibition is ascribed to a change in the tertiary structure of the enzyme.
Direct Spectrophotometric Determination of Gold in Alloys as Chloroaurate
Authors: Avinur P. 
Published: November 2013

AbstractA method is presented for a simple and direct determination of gold in alloys, utilizing a preliminary separation of gold from an alloy, and its subsequent conversion to chloroauric acid.The optical density of the chloroaurate ion is measured at two selected wavelengths, calculating the gold content of alloys by using the absorbance difference technique as developed by Glasner and Avinur. A suitable technique enables wide‐range determination in various samples of gold alloys ranging from 0.001% to over 90% gold content. Platinum does not interfere when present in small amounts in the alloy.
The Mixed Compounds of Calcium and Titanium With Tiron. I
Authors: Barzily I. , Yaalon D. H. , Avinur P. 
Published: November 2013

AbstractA pH‐spectrophotometric study of the Ti‐tiron complex in the presence of Ca ions revealed the existence of mixed compounds of Ca‐Ti‐tiron. These could account for the interference of Ca in the determination of Ti by tiron. The formation of these mixed compounds under varying concentrations of components and at varying pH is discussed. The absorbance of the Ti‐tiron was likewise studied in the presence of many colorless salt solutions, but the behavior of Ca was found to be unique. Use was made of the color of the mixed compounds of Ca‐Ti‐tiron to develop a method for the identification of small amounts of Ca in the presence of large quantities of many common salts.
Flash Photolysis of Hydrogen Peroxide I: The Reaction of Ozonide with Hydrogen Peroxide
Authors: Behar D. , Czapski G. 
Published: November 2013

AbstractThe photochemistry of basic aqueous solutions containing hydrogen peroxide and oxygen has been investigated by the flash photolysis method. The decay of O3− was followed at 4300 Å over the pH range 13 – 13.7 as a function of hydrogen peroxide and oxygen concentrations. The decay was found to be of the first order under all conditions −[d(O3)−/dt] = kobs[O3−]. The pseudo first‐order rate constant kobs was found to be dependent on H2O2 and O2 concentrations. A mechanism which is consistent with the experimental results is suggested.
Scavenging Kinetics in the Photochemistry of Some Ions in Aqueous Solution
Authors: Czapski G. , Ottolenghi M. 
Published: November 2013

AbstractGeminate recombination has been previously suggested in the photochemistry of several ions in solution, namely, the halides, phenolate ferrocyanide and thiocyanate. It is demonstrated that in the concentration range studied, the observed dependence of the quantum yield on scavenger concentrations is due to homogeneous competition between the scavenger and a product or rational intermediates, rather than to cage scavenging competing with geminate recombination.
On the Synthesis and Spectral Properties of Iron‐ Cyanoferrates
Authors: Ben‐Bassat A. H. I. 
Published: November 2013

AbstractA new procedure for the synthesis of Prussian Green, using HNO3 or dioxane media, is proposed. Synthesis from aqueous H3Fe(CN)6 is described. I.R. spectra of solids and of colloidal suspensions of Prussian Brown, Prussian Green and Prussian Blue are recorded and discussed. An explanation for the 1960 cm−1 vibration stretching is proposed. The identity between Prussian and Turnbull Blue is questioned owing to I.R. results. A mechanism is proposed for the suggested oxyreduction reaction, based on analytical and mass spectroscopy data. Protonation of the complexed iron plays an important role in these reactions. Explanations for contradictory properties and Mössbauer results cited in literature are given.
Heterometric Titration of Sodium Montmorillonite with Calcium Nitrate
Authors: Lurie D. , Yariv S. 
Published: November 2013

AbstractIn the heterometric titration of sodium montmorillonite with calcium nitrate, a titration curve comprising four stages is obtained. The first stage, attributable to the exchange reaction taking place at the sites of broken bonds, shows no change in transmittance upon addition of the salt. The second stage shows a decrease in transmittance attributable to the exchange reaction taking place in the interlayer space. The third stage demonstrates the completeness of the exchange reaction and the exclusive presence of calcium montmorillonite, since no change in transmittance takes place as the reagent is added. The fourth stage shows an increase in transmittance, but the reaction is obscure. The transition point, obtained by extrapolation of the straight portion of the second and third stages, is defined as the “endpoint” of the titration, and is equivalent to the exchange capacity of the clay.
Particle Interaction and Soil Swelling
Authors: Quirk J. P. 
Published: November 2013

AbstractParticle interaction discussed in this paper may be limited, in which contiguous interacting plate shaped particles are within 10 Å of each other, or extensive, in which surface separations exceed 40 Å. Extensive swelling is caused by the interaction of Gouy‐Chapman diffuse double layers and the conditions under which diffuse double layer theory can be used to describe extensive swelling are re‐viewed. The essential feature of extensive swelling is its dependence on electrolyte concentration.X‐ray studies of the variation of d(001) spacings for montmorillonite and vermiculite when saturated with divalent and large monovalent ions have been discussed as examples of limited swelling. This behaviour is contrasted with sodium montmorillonite which exhibits extensive crystalline swelling for concentrations less than 0.3 M NaCl.The similarity of the swelling behaviour of a montmorillonite crystal and of a parallel assemblage of crystals constituting a domain has been noted and presented as an argument for domains being regarded as particulate entities in calcium saturated clay materials.The limited crystalline swelling of calcium montmorillonite and domain swelling of calcium saturated clays is little affected by electrolyte concentrations less than molar. The inter‐crystalline swelling which occurs in soils and clay materials is triggered off by the adsorption of two layers of water; the adsorption of the two layers of water at areas of crystal overlap release mechanical energy stored as a result of crystal bending and packing on the drying cycle. This release of mechanical energy creates pores in which liquid is held by surface tension forces as distinct from water held at the clay solution interface by hydration and osmotic forces.The use of chloride exclusion measurements to provide information on the nature of particle interaction is discussed. The information presented on domain structure and ion distribution at interfaces, as deduced from chloride exclusion measurements, reveals that diffuse double theory is completely inadequate for describing swelling of calcium clay systems and for predicting the pore solution composition.
Ferrous‐Ferric Ratio and CEC Changes on Deferration of Weathered Micaceous Vermiculite
Authors: Roth C. B. , Jackson M.L , Lotse E. G. , Syers J. K. 
Published: November 2013

AbstractFerrous iron in the layers increased 2‐fold or more on deferration of coarser fractions of micaceous vermiculite naturally weathered from biotite (Colorado and Transvaal sources). The ferric iron content of the layers was decreased by the deferration treatment but the original content was restored by subsequent H2O2 treatment. Sesquioxide coatings on micaceous vermiculite from Colorado, examined electron microscopically, were composed predominantly of Fe2O3 (80 to 85 percent), along with Al2O2 and SiO2. The CEC increased from 64 to 95 meq per 100 g in the fraction coarser than 1000 microns and 50 to 64 meq per 100 g in the fraction 2–0.2, microns in diameter, as a result of removal by deferration of positively charged sesquioxide coating which had originally blocked a portion of the CEC. Although treatment with H2O2 after deferration restored the Fe3+ content to approximately the original value, the CEC was not affected probably because of deprotonation OH− → O2− + H+ occurring simultaneous with Fe2+ → Fe3+.
Effect of Various Treatments on the Optical Properties of Montmorillonite Suspensions
Authors: Lahav N. , Banin A. 
Published: November 2013

AbstractThe light absorption spectra of Na, K, Ca and Ba‐montmorillonite suspensions were studied in relation to the procedure of sample preparation. These procedures included different sequences of transformations from one homoionic form into another, as well as a drying stage during the preparation.The optical density was usually influenced by the method of preparation, indicating hysteresis effects in the transformation process. The data were interpreted in terms of tactoid formation and size.Transformation of monovalent into divalent clay suspensions resulted in small tactoids. Air drying of the clay before the transformation resulted in larger tactoids in both mono‐ and divalent clays. Negative adsorption of chloride in Ca‐bentonite from two different preparations (which differed in their tactoid size) were in agreement with the light absorption measurements: the higher surface area was found in the suspension with the smaller tactoids.The data available in the literature on negative absorption of chloride on montmorillonite are discussed. It is suggested that the discrepancies in the experimental results of different investigators could be, at least partially, explained by the differences in the preparation procedure of the clay suspensions.