bluuebunny/crossref_metadata_2025 huggingface dataset:
The Characteristic Curve Method in Adsorption
Authors: Tolmachev A.M.
Published: July 2017

The application of the characteristic curve method (CCM) for the calculation of adsorption equilibria is discussed. It is shown that in the case of microporous adsorbents the CCM enables a priori calculations of adsorption equilibria in one- and multi-component systems over a wide range of temperature and equilibrium phase compositions employing only very limited ‘basic’ experimental information.
Chemical Activation of a South African Coal using Phosphoric Acid
Authors: Botha François D. , Mcenaney Brian
Published: July 2017

The potential of a South African coal, Bosjesspruit, as a precursor for a phosphoric acid-activated carbon has been assessed using the adsorption of nitrogen at 77 K and mercury porosimetry. Column cleaning of the coal by froth flotation reduced the ash content from 22 to 12 wt.% and caused maceral separtion, resulting in an intertinite-rich product. Reaction of the column-cleaned coal with phosphoric acid in the range 450–550°C produced an activated carbon which was dominantly microporous. The notional BET surface area of the coal reached a maximum of 600 m2/g at a reaction temperature of 550°C.
Pore Structure Alteration of a Carbon Molecular Sieve for the Separation of Hydrogen Sulfide from Methane by Adsorption
Authors: Pan Z.J. , Chen S.G. , Tang J. , Yang R.T.
Published: July 2017

The equilibrium adsorption of H2S is substantially stronger than that of CH4 on carbons, including carbon molecular sieve (CMS). A carbon molecular sieve with a proper pore structure can provide a kinetic selectivity for H2S over CH4, thus further enhancing the overall selectivity (equilibrium plus kinetic) for H2S and providing the basis of natural gas desulfurization by adsorption. Kinetic selectivity requires a unique pore structure due to the small difference in the molecular dimensions of H2S and CH4 (~0.2 Å). Equilibrium and diffusion rate data for CH4 and H2S at 25°C have been measured in three commercial carbon molecular sieves: Bergbau Forschung CMS, Takeda CMS 3A and Takeda CMS 5A. The pores are either too small (in the two former carbons) or too large (in CMS 5A) for H2S/CH4 separation. Alterations to the pore structure either by controlled oxidation or carbon deposition by pyrolysis have been studied. Optimal results were obtained by pyrolysis of propylene on CMS 5A under the following conditions: 0.05 atm, 700°C, 5 min, weight gain of 0.67%. The resulting carbon molecular sieve retained the high equilibrium adsorption capacities while yielding a diffusion time constant ratio for H2S/CH4 of 8.2. This carbon is suitable for natural gas desulfurization by adsorption processes such as pressure swing adsorption. Temperature was the most important variable in pore structure alteration by carbon deposition. Under the optimal pyrolysis conditions, carbon was only deposited near the pore entrances.
Adsorption Properties and Structure of Some Active Carbons
Authors: Bardina I.A. , Kalashnikova E.V. , Kovaleva N.V. , Rudnitskaya T.A. , Shonya N.K.
Published: July 2017

Gas chromatography has been used to determine the initial low-coverage heats of adsorption of C2–C6 hydrocarbons and their derivatives on active carbon and graphitized carbon black. The porous structure of the active carbon has been determined from the adsorption isotherms of benzene measured at 25°C by a vacuum static method. The isotherms have been analyzed with the help of the BET and Dubinin–Radushkevich theories.
An Investigation of the Possibility of Diameter Reduction for Polystyrene and Styrene-Divinylbenzene Copolymer Granules Obtained by Suspension Polymerization
Authors: Markovska R.P. , Ostapovich B.B. , Elagin J.I.
Published: July 2017

The reduction in the mean diameter of polystyrene and styrene-divinylbenzene copolymer granules, brought about by suspension polymerization, has been investigated. For this purpose, emulsifiers containing hydrophilic polyethylene glycol fragments were added to a stabilizer [starch, poly(vinyl alcohol) or polymethacrylic acid with 10 mol% methylmethacrylate units]. The emulsifiers investigated such as ‘Stearox’ (20s-oxyethylated stearic acid), ‘Phenoxol’ (15s-oxyethylated phenol) and ‘APhO’ (10s-oxyethylated alkylphenol) were found to reduce the mean diameters of granules by a factor of 10 or more. The same tendency was observed when benzoyl peroxide was replaced by the surface-active oligomeric peroxide of sebacinic acid whose surface activity is due to the polymeric chain ends.
Studies of the Adsorption of SO2, H2 and O2 on a Cr2O3 Surface by an Electrical Conductivity Technique
Authors: Khader Mahmoud M. , Saleh Mahmoud M. , Mohammad Ahmad M.
Published: July 2017

Electrical conductivity measurements have been used to detect extremely small changes in the oxygen content of oxide semiconductors in contact with reducing or oxidizing gases. In continuation of previous studies, the oxygen loss of chromium oxide in H2 and SO2 flows, as well as the oxygen gain in an oxygen atmosphere, were studied. In SO2, the conductivity dropped instantaneously to minimum values due to its adsorption on adsorbed oxygen sites. The treatment of Cr2O3 in SO2 led to the elimination of chemisorbed oxygen and the covering of the surface with polymeric SO2. In contrast, in an H2 flow, the conductivity of Cr2O3 initially exhibited an induction period during which the value was constant. At the end of the induction period, the conductivity increased rapidly to a maximum value and then dropped sharply to a minimum. The induction period may be regarded as the time necessary to create an oxygen vacancy, the activation energy for such a process being 21.1 kJ/mol. A hydrogen molecule is then adsorbed on to the oxygen vacancy possibly as a hydride ion, and leading to the initial increase in the conductivity. The hydride ion then migrated to a chemisorbed oxygen site, where it formed a surface hydroxy group and caused a consequent decrease in the electrical conductivity. The surface then dehydroxylated due to the interaction of surface hydroxy groups with gaseous hydrogen, leaving coordinatively unsaturated surface chromium ions behind.

In an oxygen flow at 400°C and above, either SO2 or H2 treatments led to a sharp increase in conductivity due to oxygen adsorption. In contrast, at temperatures less than 350°C, oxygen adsorption was retarded after an SO2 flow, possibly due to the strong adsorption of a polymeric film of SO2. Correspondingly, after H2 treatments, oxygen was adsorbed instantaneously at temperatures as low as 200°C, presumably because of the weak sorption of H2 on the surface chromium ions.

After discontinuing the hydrogen flow, further oxygenation caused a subsequent decrease in the conductivity, possibly due to surface hydroxylation. Hydrogen trapped in the bulk of the Cr2O3 could spill over the surface and cause such a hydroxylation process.
Co-Adsorption of Mixed Cationic/Non-Ionic Surfactants on a Quartz Surface
Authors: Nikoorazm Mohsen , Nagarkar Jayashree , Dixit Sharad
Published: July 2017

The co-adsorption of binary mixtures of tetradecyltrimethylammonium bromide (TTAB) and nonyl phenyl ethoxylates (NP-n series) from their aqueous solutions on to quartz has been studied. None of the ethoxylates adsorbed on to the quartz when alone, but considerable adsorption took place from the mixture with cationic TTAB. The adsorption of TTAB was increased in the presence of ethoxylates below its CMC due to chain–chain interaction between the cationic/non-ionic surfactants. FT-IR spectroscopic studies indicated that micelle-like aggregate structures formed on the quartz surface even below the CMC. Zeta potential measurements were carried out in order to understand the adsorption behaviour.
Ion-Exchange Properties of Transcarpathian Natural Zeolites
Authors: Gomonaj V. , Szekeresh K. , Gomonaj P. , Golub N.
Published: July 2017

The adsorption of ammonium ions, radionuclide ions (Sr2+ and Cs+) and heavy metal ions (Ni2+, Cr3+, Fe3+ and Hg2+) on natural Sokyrnytsky clinoptilolite has been investigated. Effective cation exchange of heavy metal ions and radioactive elements was observed with samples of the clinoptilolite which had been pretreated with ammonium chloride solutions. The adsorption isotherms for such cations from solutions of 0.5–1.0 mg/l ion content were studied under static conditions for adsorbent particle size fractions of 1.5–2.5 mm. Solid phases and solution aliquots were analyzed by X-ray fluorescence methods for Sr2+ ions while the concentrations of other ions were analyzed by spectrophotometric methods.
Surface Properties and Catalytic Activity of Ni/Al2O3–AlPO4 Catalysts
Authors: El-Hakam S.A. , El-Khouly A.A. , Khder A.S.
Published: July 2017

A series of Ni/Al2O3–AlPO4 catalysts has been prepared, thereby allowing the effect of nickel content and calcination temperature on the structural and catalytic activity of such solids to be investigated. The textural parameters of all the prepared samples were determined from nitrogen adsorption studies conducted at −196°C, while thermal analysis methods (DTA, TGA and DrTGA) and X-ray diffraction techniques were used to elucidate their structures. Their surface acidities were measured by the amine titration method, while the conversion of isopropanol on the prepared catalysts was investigated using a pulse microcatalytic reactor.

Significant changes in the structure, texture, surface acidity and catalytic activity of the prepared solids were observed as a result of varying their nickel content and calcination temperatures. Thus, XRD studies demonstrated the presence of nickel metal, nickel aluminate spinel, γ-alumina and tridymite phases while both the surface areas and the porous structures were found to depend on the metal content and calcination temperatures. The catalytic selectivity for isopropanol conversion was found to depend on the number of surface acid sites present.
Adsorption Studies of CuII from Aqueous/Acidic Solutions on to Bentonite
Authors: Rauf N. , Ikram M. , Tahir S.S.
Published: July 2017

The ability of bentonite to remove CuII from aqueous and acidic solutions at different pH values has been studied for different adsorbate concentrations by varying the amount of adsorbent, temperature and shaking time. The maximum (85%) adsorption of CuII was achieved from aqueous solution at pH 3.8. The influence of different anions and cations in the 0–1000 μg/ml concentration range on the adsorption of copper under optimized conditions has been examined. A flame atomic absorption spectrometer was used for measuring the copper concentration before and after adsorption. Isotherm analysis of the adsorption data obtained at 25°C, 30°C, 40°C and 50°C showed that the adsorption of copper(II) on bentonite could be described by both the Langmuir and the Freundlich isotherms. Values of ΔH0 and ΔS0 were calculated from the slope and intercept of the ln KD versus l/T plots.
Translating nature: river restoration as nature-culture
Authors: Eden Sally , Tunstall Sylvia M , Tapsell Susan M
Published: July 2017

In this paper we examine the process of river restoration at the river Cole in southern England. We argue that analysing such environmental transformations as actor-network translations or ‘nature-cultures’ can provide an integrative perspective on the process of restoration and its intertwining of natural and human actors and help to avoid the traps of defining ‘nature’ and separating it from society; traps which open up before environmental philosophy when examining restoration. However, a translation perspective is less helpful in evaluating or prescribing restoration as environmental management.
An Experimental Study of Impregnation Conditions on Glass Fiber Reinforced Thermoplastic Polyester Elastomer Composites
Authors: Shonaike G. O. , Matsuo T.
Published: July 2017

A study was conducted on the effects of variables such as impregnation and cooling conditions on bending properties of glass fiber reinforced thermoplastic elastomer composites. The impregnation time was varied between 5 and 30 minutes and samples were cooled under rapid and gradual cooling conditions. A bending test was carried out on samples with different fiber orientations. Detailed evaluations on thermal properties and morphology were obtained using a differential scanning calorimeter (DSC), a scanning electron microscope (SEM) and an optical microscope. Impregnation of matrix resin into glass fiber was completed before 30 minutes impregnation time. Bending properties were found to increase with increasing impregnation time. SEM micrographs revealed poor adhesion between the matrix resin and glass fiber. This was attributed to the structure of the thermoplastic polyester elastomer. Thermal properties such as melting and glass transition temperatures were not affected by the cooling conditions. The degree of crystallinity by rapid cooling was less than by gradual cooling.
Hybrid Effect in the Mechanical Properties of Short Sisal/Glass Hybrid Fiber Reinforced Low Density Polyethylene Composites
Authors: Kalaprasad G. , Thomas Sabu , Pavithran C. , Neelakantan N. R. , Balakrishnan S.
Published: July 2017

Hybrid composites of low density polyethylene (LDPE) reinforced with intimately mixed short sisal and glass fibers were prepared by solution mixing technique. The mechanical properties of these composites have been investigated with reference to the effects of orientation and composition of fibers in them. It has been observed that the composites contining longitudinally oriented fibers exhibit better mechanical properties than those with randomly oriented ones. Also it is seen that the mechanical properties increase with increase in the volume fraction of glass fibers in the hybrid composites. The effict of chemical modification of sisal fibers on the properties of 50:50 sisal/glass fiber composites has also been studied. The hybrid effect was calculated by the additive rule of hybrid mixtures using the mechanical properties of individual composites. A positive hybrid effect was echibited by the composites for all the mechanical properties except for elongation at break.
Study on the Polypropylene/High Density Polyethylene/Styrene-Butadiene-Styrene Block Copolymer Ternary Blends: I-Composition, Morphology and Properties of Polypropylene/High Density Polyethylene/Styrene-Butadiene-Styrene Block Copolymer Blends
Authors: Chiu D. S. , Zhang Z. , Siu G. G.
Published: July 2017

Thermoplastic elastomers, e.g., EPR, EPDM etc., are commonly used as modifiers of the ductility of PP, PE, HDPE or other general purpose thermoplastics. The objective of this study is to develop a high performance PP/HDPE/SBS polymer blend which possesses excellent toughness and strength equivalent to those of more expensive high-grade engineering plastics and to investigate the change of ratio of PP, HDPE and SBS with morphology and mechanical properties of the blend. It was found that the introduction of HDPE into the mixture of PP/SBS gives rise ternary blends possessing not only super high ductility and impact strength (over 700 J/m), but also balanced mechanical properties (high tensile strength and flexural strength), as well as excellent thermal resistance and processing properties. It was also found that the morphology of the PP/HDPE/SBS ternary blends is a multiphase system. It appears that the resulted complex morphology renders the high performance of the ternary blends.
Notes on the Modeling of Preform Compaction: I -Micromechanics at the Fiber Bundle Level
Authors: Simacek Pavel , Karbhari Vistasp M.
Published: July 2017

Resin Transfer Molding (RTM) can be described as a two step process: fiber preforming followed by resin infusion and cure. In the first stage, the fabric form making up the preform element is placed in the tool and is compacted due to the pressure from tool closure. During this process, the microstructure, and the resultant properties, change considerably since compaction flattents the weft yarn bundles from the initial configuration into flat ellipsoids of higher aspect ratio, while simultaneously reorienting and flattening the bundles in the warp direction. The movement also results in nesting and inter-layer packing yielding a higher localized fiber volume fraction.

An aspect unique to RTM and other allied resin infusion processes is the compaction of fibers in the dry (unlubricated) form. This gives rise to rather unique behavior at the fiber tow level, which in turn affects the compaction of the fabric form itself. It is thus essential that any model constructed for the specific purpose of investigating the compaction stage in RTM (or allied processes that involve the compaction of a dry preform) be able to reflect that the tow is dry, usually untwisted and when compressed in bulk it has frictional resistance to the shear mode of deformation. In this paper we focus on the possible tow behavior, rather than the behavior of the fabric structure, with the motivation being that of developing a simple, yet comprehensive model at that level which can then be intregrated into a fabric level model at a later stage.
Nondestructive Characterization/ Evaluation of Functional Sandwich and Hybrid Carbon-Carbon Composites
Authors: Vaidya U. K. , Mahfuz H. , Jeelani S.
Published: July 2017

Carbon/carbon (C/C) composites were developed on a conceptual basis with a goal of developing low cost functional composites. The current approach in chooing a precursor material system deviates from conventional C/C systems in that nonwoven carbon mat reinforcement is used in conjunction with continuous fabric. C/C composite systems considered in this study are classified into two categories; hybrid and sandwich. These composites were fabricated from continuous woven carbon fabric in plain, eight harness satin (8HS) and stretch broken weave architectures along with nonwoven carbon mat reinforcement. In sandwich composites, the nonwoven mat is sandwiched between continuous fabric reinforcement; while in hybrid composites, the nonwoven mat is alternated with continuous reinforcement. Ultrasonic and vibration based nondestructive evaluation/characterization (NDE/C) was conducted at three processing stages, namely; as-cured, after first carbonization and after first densification. Ultrasonic velocity measurements in the in-plane and through-the-thickness directions were found to be influenced by the evolving material microstructure and fabric architecture. Vibration damping of sandwich and hybrid composites was found to be an order of magnitude higher than conventional woven C/C composites. Acoustic emission (AE) signatures from the two composite systems were correlated to matrix cracking, fiber filament and bundle fracture, onset and occurrence of delamination and failure of the nonwoven layer(s). With regard to processing, the incorporation of nonwoven carbon mat in conjunction with continuous reinforcement enabled rapid infiltration during densification stage of sandwich and hybrid C/C composites.
Analysis of Impact Thresold Energy for Carbon Fibre and Fabric Reinforced Composites
Authors: Ying Yan
Published: July 2017

Damage resistance ofthree different carbon fibre and fabric reinforced composites are evaluated after drop-weight impact damage. Finite element analysis coupled with failure criteria developed to predict the impact threshold energy of the laminates. The predicted impact threshold energy agreed reasonably well with the analytical values based on experimental data. An analytical method for predictions of maximum contact force and radius of contact region at different impact energy were presented in order to provide necessary information for finite element analysis.
A Scientific Approach to Screw Design
Authors: Chung Chan I.
Published: July 2017

Screw design technology is considered to be empirical and secretive. The production rate of single-screw extruders is often limited by the melting capacity. The melting capacity of a screw depends on the polymer properties, the processing conditions and the particular geometry of the screw. Once the melting capacity is predicted, the screw can be designed to match the melting capacity. This paper presents a scientific approach to screw design based on an analytical melting model, with an example.
Cutting Behavior of Composite Prepregs
Authors: Wang Yuan , Hoa Suong V. , Osman M. O. M.
Published: July 2017

Two types of composite prepregs were selected to conduct experimental study on cutting. Both were cut in different conditions to investigate the fiber deflection of prepregs due to cutting. Also, the effect of cutting parameters on the strength of laminates made of cut prepregs was investigated. For unidirectional prepreg cutting, factors such as primary knife angle a, knife sharpness and relative orientation between cutting direction and fiber direction 6 have significant effect on fiber deflection. The firmness of backing plates is not an important factor. The fiber deflection of unidirectional prepreg due to cutting is not large enough to have significant effect on the strength of coupons made from these prepregs. For woven prepreg cutting, the fiber deflection is large and has some effect on the strength of coupons.
Buckling of Vertically Loaded Fiber-Reinforced Polymer Piles
Authors: Han Jie , Frost J. David
Published: July 2017

Fiber-Reinforced Polymer (FRP) composites are considered to be a potentially promising material for use as pile foundations in harsh environments such as industrial or matine conditions. As with piles made of other materials, FRP piles may buckle under extreme loading situations during their installation by driving orjacking into soils or when they are subjected to permanent superstructure loads. Since FRP composites generally have anisotropic properties, relatively low moduli, and relatively high elastic to shear modulus ratios compared to steel, for example, the shear deformation effect plays a more important role in dictating the buckling loads of FRP piles. In this paper, the Timoshenko beam theory is adopted to derive solutions which include the shear deformation effect for buckling loads of vertically loaded transversely isotropic FRP piles with five different boundary conditions. Parametric studies show that the buckling loads for the cases where the shear defonnation effect is considered are always lower than when the shear deformation effect is ignored.
Tension in Multilayer Film Casting of Polymer Melts
Authors: Bian Baigui , Co Albert
Published: July 2017

Measurement of tension in molten films can be used to control the quality of film products. It is also critical to the analysis and the modeling of the film casting process. In this work, the film tension of three-layer film consisting of LDPE and LLDPE were measured using a non-contacting air nozzle system. The dependence of film tension on draw ratio and film thickness fraction was related to the rheological properties of the polymer melts. Oscillation of film tension was observed when draw resonance occurred. The frequency of thickness oscillation in the solidified film was found to be similar to that of the tension oscillation in the molten film.
Ultrasound: A Virtual Instrument Approach for Monitoring of Polymer Melt Variables
Authors: Brown E. C. , Collins T. L. D. , Dawson A. J. , Olley P. , Coates P. D.
Published: July 2017

Non-invasive ultrasound measurements are not currently widely used, due to limitations in high temperature transducer technology and signal processing. These have been addressed in the ultrasound program in our laboratory, where high frequency sampling using our own high temperature probes is now available. The need for high frequency sampling of the ultrasound signal to resolve measurements of transit time (and amplitude) to the required accuracy requires handling of large amounts of data, and in the case of actual polymer processing such as extrusion, data processing needs to be real time. A computer controlled system for the acquisition of such data is described here, with examples of the sensitivity of the measurements to a range of polymer melt process variables, including polymer composition and fillers, for extrusion and injection moulding processing.
Residual Stresses Reduction in Filament Wound Composite Tubes
Authors: Binienda W. K. , Wang Y.
Published: July 2017

Sources of residual stresses in composite materials and methods of their reductions are discussed and analyzed rigorously for one dimensional micro-mechanical model and numerically for axisymmetric filament wound composite tube model using finite element analysis (FEA). The incorporation of mechanical preload to the fabrication process is discussed and two designs of an expandable mandrel are proposed. Two processes, conventional and with preload, are numerically simulated for residual stresses.
Simulations and Applications of Injection-Compression Molding
Authors: Chen Shia-Chung , Chen Yung-Chung , Cheng Nien-Tien , Huang Ming-Shyan
Published: July 2017

A numerical algorithm is developed to simulate the injection-compression molding (ICM) process and to predict melt front advancement, the distributions of pressure, temperature and flow velocity. Processing characteristics were understood by changing processing parameters including compression speed, switch time from injection to compression, compression stroke, as well as initial cavity thickness and part thickness. The simulated molding pressures were also compared with those required by conventional injection molding (CIM). It was found that the compression speed and compression stroke are the two factors affecting the molding pressure most significantly. Switch time also shows apparent effect on the pressure profiles. Using lower switch time, lower compression speed and higher compression stroke will result in lower cavity pressures. The percentage reduction in molding pressure is higher if part becomes thinner when using ICM. The melt velocity far from the gate was found to be higher than that near the gate during the compression stage contrary to that of CIM resulting in different part residual stress and melt temperature distribution. The simulated pressures for both ICM and CIM show good coincidence with those obtained from cavity pressure measurements.
Effect of Ply Thickness and Fibre Orientation on Delamination Initiation in Broken Ply Composite Laminates
Authors: Chakraborty Debabrata , Pradhan B.
Published: July 2017

The present study examines the delamination initiation at the interface of broken and continuous plies in case of GR/E and GL/E laminates with broken central plies. A full 3D FE analysis has been performed with each layer of the laminate modelled as homogenous and orthotropic. The interface between the broken and continuous plies has been modelled with a thin resin rich layer. Eight-noded isoparametric layered elements have been used to model the laminate specimen. Also, 3D contact elements are used to prevent the interpenetration of delaminated faces at the interface. Based on the results of 3D FE analysis, GI, GI, and GI,, have been calculated at the delamination front using Irwin's Crack Closer Integral. It has been observed that the delamination initiation is a mixed mode phenomenon even in the case of uniaxial loading. Brewer and Lagace's Quadratic Stress Criterion has been used in conjunction with Linear Elastic Fracture Mechanics (LEFM) to calculate the delamination initiation strain and the critical strain energy release rate (Gc). The effects of various factors such as ply thickness, fiber orientation, resin stiffness on Gc have been studied for GR/E and GL/E laminates having broken central plies.
Synthesis and Characterization of p-Borono-Phenylalanine-Branched Polypeptide-Monoclonal Antibody Ternary Systems for Potential Use in Boron Neutron Capture Therapy (BNCT)
Authors: Mezö Gábor , Hudecz Ferenc , Szekerke Mária , Kajtár Judit , Sármay Gabriella , Gergely János , Nagy Zsuzsa , Clegg J. A.
Published: July 2017

The application of the 10B ( n,α) 7Li capture reaction to cancer radiotherapy (Boron Neutron Capture Therapy) was studied to avoid the inherent disadvantages of conventional radiation therapy. p-Borono-phenylalanine (Bph) was used as the 10B source and mAb produced against HCMB melanoma cells was applied as targeting device. Since extensive direct boronation of mAb led diminished recognition of antigens, an intermediate carrier was used. Nontoxic, biocompatible, biodegradable and weakly immunogenic branched polypeptides with a polylysine backbone was used to carry a high number of 10B. Protected 10B-Bph was coupled by four different methods to polycationic branched polypeptides. The coupling efficiency varied according to the experimental conditions, with a maximum of 90%. The chiroptical properties of the conjugates indicated an ordered conformation which increased with the number of coupled Bph. The whole body survival (WBS) and tissue distribution profile of mAb (8/6 IgG2a) were markedly altered after conjugation with Bph-branched polypeptide. Decreased WBS and intermediate-carrier-dependent accumulation in the spleen, liver and kidney was observed 24 h after iv. administration. After joining only a few chains of the highly loaded Bph-AK conjugate to mAb, the binding activity of the mAb in the ternary system was preserved compared to control.
Sustained Release of Cisplatin in Dogs from an Injectable Implant Delivery System
Authors: Dunn R. L. , Yewey G. L. , Fujita S. M. , Josephs K. R. , Whitman S. L. , Southard G. L. , Dernell W. S. , Straw R. C. , Withrow S. J. , Powers B. E.
Published: July 2017

Cisplatin was incorporated into an in-situ forming biodegradable implant delivery system (ATRIGELO) consisting of a biodegradable polymer dissolved in a pharmaceutically acceptable solvent. The polymer solution with the suspended cisplatin was injected subcutaneously into the flank or shoulder of six healthy beagle dogs where the water-insoluble polymer precipitated upon contact with body fluids and formed a solid implant for the controlled release of the drug. Each dog received four injections, spaced thirty days apart, of a formulation containing either poly(DL-lactide-co-caprolactone) (PLC) or pely(DL-lactide-co-glycolide) (PLGA) dissolved in dimethyl sulfoxide (DM8O) and loaded with 8% by weight cisplatin. Dosage levels of 70, 105, and 157.5 mg/m2 were used to determine dosage escalation effects. Injections of the same formulations without the drug served as controls. Samples of blood were taken at appropriate times over the four months of treatment and analyzed for platinum concentration by atomic absorption spectroscopy. Local tissue and systemic toxicities were also determined. Both formulations exhibited sustained release of cisplatin with peak serum concentrations of platinum being attained in about two days followed by gradually decreasing platinum levels to day thirty. Consistent drug release profiles were observed for each of the four thirty-day treatment periods. The dosage escalation results exhibited an approximate 50% increase in peak platinum levels and area-under-the-curve (AUC) values for each 50% increase in drug dose. Local tissue toxicity to the cisplatin-containing implants was variable and appeared to be unrelated to dose level or direction number. Tissue reaction to the implants without drug was minimal indicating a role of cisplatin in the tissue reactions. Systemic toxicity, as judged by clinical parameters and clinicopathologic evaluation, was not noted at any dose level or injection time.
Production of K5 Polysaccharides of Different Molecular Weight by Escherichia Coli
Authors: Manzoni Matilde , Bergomi Silvia , Cavazzoni Valeria
Published: July 2017

An investigation was made of the molecular weight of the Escherichia coli antigenic K5 polysaccharide. Two components with molecular weights of 16,000 and 1,500 were observed. The ratio of these two components depended on a lyase produced by the same E. coli. This lyase acts by a β-elimination mechanism to depolymerize the K5. At the end of the fermentation the thermally treated (to inactivate the lyase) and untreated twenty-four-hour-old cultures each contained two K5 components of different Mw, in different ratios. The two components were monitored over a fermentation time-course. "3C-NMR spectrometry was employed to verify the lyase mechanism of action.
Water Transport in Hyaluronic Acid Esters
Authors: Netti P. A. , Del Nobile M. A. , Ambrosio L. , Mensitieri G. , Nicolais L.
Published: July 2017

Hyaluronic acid esters belong to a new class of polymers which have been developed in order to overcome water sensitivity displayed by hyaluronic acid. In this paper the effects of the substituting group on the water vapor transport properties were investigated. In particular, water sorption isotherms and kinetics for three types of hyaluronic acid esters (ethyl, dodecyl and benzyl esters) were determined. The type of substituent group has been found to affect polymer hydrophilicity and, consequently, the water swelling properties.
α,β-Poly(N-Hydroxyethyl)-DL-Aspartamide Hydrogels as Drug Delivery Devices
Authors: Pitarresi Giovanna , Tomarchio Vincenzo , Cavallaro Gennara , Giammona Gaetano , Castelli Francesco
Published: July 2017

α,β-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) was exposed to gamma radiation to obtain micromatrices able to swell in an aqueous medium. Crosslinked PHEA was loaded with an anti-inflammatory drug, 4-biphenylacetic acid (BPAA) and the drug dispersion in the network was investigated by X-ray analysis. The BPAA loaded PHEA microparticles were also characterized by dimensional analysis, which showed the presence of quasispherical shapes. The drug release from PHEA hydrogel was studied in vitro in a pH 1.1 (simulated gastric juice) and in a pH 7.4 buffer solution, respectively. The experimental data indicate that an anomalous delivery occurs, but Fickian diffusion through swollen PHEA hydrogel seems to be the predominant release mechanism. The interactions between PHEA microparticles and dimyristoil-phosphatidylcholine (DMPC) liposomes, chosen as biomembrane model, were studied by a differential scanning calorimetry (DSC) technique. The calorimetric results show that the cross-linked PHEA network does not interact with the DMPC liposomes.
The Environment and the Role of Gas
Authors: Cornot-Gandolphe Sylvie
Published: July 2017

The combustion of fossil fuels causes the emission of greenhouse gases such as C02, methane and NOx. The use of natural gas in place of oil and coal can help indeed to reduce greenhouse gases emission because natural gas is the cleanest of fossil fuels. Its non-pollutant character offers it extremely favourable prospects. World consumption is bound to increase rapidly, from 2120 Bern in 1991 to 3100-3500 Bern in 2010. Expanding world output will not raise any problems of resources because natural gas is an abundant energy source. However, gas production and transport costs are going to rise due to increasing distances between main gas reserves and consumer markets. The financial constraints will be the major factor limiting the growth in natural gas trade. And new solutions would have to be found in order to implement today the projects required in the long-term.
Using the Capex Model for Environmental Policy (An Israeli Case Study)
Authors: Brovender Shlomo , Soloveitchik David
Published: July 2017

The purpose of this * and the following paper is to demonstrate the methodology for examining alternatives for reduction of air pollution subject to different environmental policies. The methodology presented in this paper is based on the optimization computer package CAPEX ** . The results obtained are based on data of the Israeli power generating system.
Examining Alternatives for Reduction of Air Pollution
Authors: Ben-Aderet Nissim , Soloveitchik David
Published: July 2017

The present paper attempts to present a medium and long-term solution for the choice of technology. The short-term solution, the use of low-sulphur fuel oil, has been in effect for about three years in Israel and its quantity has gradually increased. The time has now come to consider the long-term solutions. The results obtained indicate the existence of several alternatives that are more effective than the system in use today.

The methodology presented is based on the optimization computer package CAPEX ** .
Lay Perspectives Concerning Global Climate Change In Vienna, Austria
Authors: LÖFstedt Ragnar E.
Published: July 2017

As a part of an international study cordinated by Dr. Willett Kempton and myself, this paper discusses the results of a survey of the Austrian public's attitudes to, and pereptions of, global climate change. Issues that emerged as important in the study are: 1) people's inability to disassociate the greenhouse effect from the ozone hole, 2) the belief that climate change is already occurring, 3) the potential role of various methods available to combat global climate change, and 4) the lay public's environmental values. These issues are identified from twenty person to person interviews which took place in Vienna during June and July of 1991 2 .
Reproductive toxicity and tissue concentrations of 3,3',4,4'-tetrachlorobiphenyl (PCB 77) in male adult rats
Authors: Faqi A S , Dalsenter P R , Mathar W , Heinrich-Hirsch B , Chahoud I
Published: July 2017

1 The aim of this study was to ascertain the reproductive effects of PCB 77 on adult male rats and to determine its concentration in the liver and testis. Adult male rats (n=15/group) were treated subcutaneously with a singledoseof18 mg/kgbw(PC18)orwith60 mg/kg bw (PC60). The substance was dissolved in a 10 ml volume of peanut oil/kg. Control rats received the same volume of the vehicle. The reproductive effects as well as the concentration of PCB 77 in the liver and testis were investigated 1, 4 and 8 weeks after treatment.

2 In both groups, the daily sperm production (DSP; 6106) remained permanently reduced in the PC18 as well as in the PC60 groups throughout the entire investigation period (DSP week 8: control: 31+7; PC18: 22+5; PC60: 20+7). The sperm number (6106) per cauda epididymis was affected only at the 1st and 4th week after treatment (control week 1: 211+67; PC18 week 1: 135+62; PC60 week 1: 142+49). Moreover, a significant increase in the percentage of abnormal sperm was observed 4 weeks following treatment in the PC18 and PC60 groups and 8 weeks after treatment in the PC60 group. Abnormal tails were the most frequent changes observed.

3 The relative testicular and prostata weights (g) were slightly increased in the PC60 group at the 1st and 4th week following treatment (testis weight: control/I: 0.46+0.02; PC60/I: 0.51+0.03).

4 The serum testosterone concentrations and effects on testis morphology were not reported.

5 The maximum concentration of PCB 77 was detected in the liver and testis 1 week after treatment. The concentration declined 4 weeks after treatment in both organs, but still a significant amount of PCB 77 was detectable in the liver as well as in the testis 8 weeks after treatment.

6 The results demonstrate that PCB 77 affects sperm variables when applied to adult rats and that the elimination of PCB 77 in the testis parallels that of the liver.
Differential recovery of acetylcholinesterase in guinea pig muscle and brain regions after soman treatment
Authors: Lintern Maxine C , Wetherell Janet R , Smith Margaret E
Published: July 2017

1 In brain areas of untreated guinea-pigs the highest activity of acetylcholinesterase was seen in the striatum and cerebellum, followed by the midbrain, medulla-pons and cortex, and the lowest in the hippocampus. The activity in diaphragm was sevenfold lower than in the hippocampus.

2 At 1 h after soman (27 mg/kg) administration the activity of the enzyme was dramatically reduced in all tissues studied. In muscle the three major molecular forms (A12, G4 and G1) showed a similar degree of inhibition and a similar rate of recovery and the activity had returned to normal by 7 days.

3 In the brain soman inhibited the G4 form more than the G1 form. The hippocampus, cortex and midbrain showed the greatest reductions in enzyme activity. At 7 days the activity in the cortex, medulla pons and striatum had recovered but in the hippocampus, midbrain and cerebellum it was still inhibited.

4 Thus the effects of soman administration varied in severity and time course in the different tissues studied. However the enzyme activity was still reduced in all tissues at 24 h when the overt signs of poisoning had disappeared.
Acute paraquat poisoning: increased toxicity in one case with high alcohol intake
Authors: Ernouf D , Boussa N , Legras A , Dutertre-Catella H
Published: July 2017

Human paraquat poisoning from accidental or intentional ingestion is very often fatal. According to the amount of paraquat involved, death can occur within hours or weeks following ingestion. The inefficacy of the various treatments undertaken have led to determine prognostic factors based upon the evolution of plasma and urine paraquat concentrations or of usual biochemical parameters. We report one case of acute poisoning which, although the ingested dose of paraquat was not massive (550 mg/kg71) and the severity indices were in favour of a delayed fatal outcome, has ended in an early death. The high blood alcohol level of the patient (3.34 g l71) seems to be the main cause of the precocity of this death (86th hour).
Hepatic injury and disturbed amino acid metabolism in mice following prolonged exposure to organophosphorus pesticides
Authors: Gomes J , Dawodu A H , Lloyd O , Revitt D M , Anilal S V
Published: July 2017

1 Chronic occupational exposure to organophosphorus and carbamate-type pesticides significantly inhibits acetylcholinesterase activity and causes morbidity. This study on mice was designed to evaluate their amino profile and to identify signs of hepatic dysfunction following their chronic exposure to mixtures of organophosphorus pesticides.

2 Laboratory mice were exposed to a formulated mixture of the six organophosphorus pesticides (Dimethoate, Chlorpyrifos, Profenofos, Pirimiphos methyl, Triazophos and Dimethoate) most commonly used in agriculture in this region of the Middle East. Doses (10% of LD50 of the mixture) were given once a week by gavage in corn oil for 7 weeks; the control group was given only corn oil. At the end of the exposure period, mice were culled and blood samples were collected to determine erythrocyte acetylcholinesterase activity, biochemical markers of liver function and concentrations of serum amino acids.

3 Erythrocyte acetylcholinesterase activity and total serum proteins decreased significantly in the exposed group. Serum concentrations of alanine aminotransferase and aspartate aminotransferase, alanine, glutamic acid, glycine, isoleucine, leucine, methionine, ornithine, proline, serine, threonine and valine were significantly increased in the exposed mice, while serum levels of cystine were decreased significantly. There were also non-significant increases in serum alkaline phosphatase, gama-glutamyl transpeptidase and some of the other amino acids.

4 Chronic exposure to mixtures of organophosphorus pesticides is associated with decreased acetylcholinesterase activity, hepatic dysfunction and disturbance of amino acids profile. Biochemical indices of hepatocellular injury and disturbed amino acid metabolism may be of value as markers of chronic exposure to such pesticides.
A comparative study of the repeat dose toxicity of grepafloxacin and a number of other fluoroquinolones in rats
Authors: Takizawa T , Hasimoto K , Itoh N , Yamashita S , Owen K
Published: July 2017

1 Grepafloxacin is a new oral fluoroquinolone with potent activity against community acquired respiratory pathogens, including Streptococcus pneumoniae, and pharmacokinetic properties which allow once daily dosing. As part of its safety evaluation a study of 4 weeks duration was performed to compare the toxicity of grepafloxacin with that of a number of commercially available quinolones in the rat.

2 Groups of eight male Sprague-Dawley rats received either control material or grepafloxacin, enoxacin, lomefloxacin, ofloxacin or ciprofloxacin at an oral dosage of 300 mg/kg/day for 4 consecutive weeks.

3 Effects related to the antibacterial activity of the drugs were seen as increased caecal weight, decreased urinary excretion of sodium, increased water consumption, decreased urine volume, increased urine osmolality, soft stools and suppressed body weight gain.

4 It is well documented that fluoroquinolones can cause lesions in the cartilage of the major diarthrodial joints, and blister formation or erosion on the joint surface was observed in all quinolone-treated groups other than the grepafloxacin group.

5 Some quinolones, have been found to cause crystal-luria, which is often associated with secondary nephropathy in laboratory animals due to the poor solubility of quinolones under the alkaline conditions of the urine. In the present study, needle-like crystals in the urinary sediment were observed in enoxacin and ciprofloxacin treated groups only.

6 In conclusion, grepafloxacin was well tolerated and showed a low potential for joint toxicity and crystalluria compared to other quinolones.
Postmortem digoxin-like immunoreactive substances (DLIS) in patients not treated with digoxin
Authors: Bentur Yedidia , Tsipiniuk Alla , Taitelman Uri
Published: July 2017

1 Endogenous digoxin-like immunoreactive substances (DLIS) cross-react in immunoassays of digoxin. The postmortem rise in digoxin levels in patients treated with the drug may be due to its redistribution. It is unclear what is the contribution of DLIS to this increase and whether DLIS are present postmortem in patients not treated with digoxin.

2 The objectives of this study were to determine whether DLIS are present after death in patients not treated with digoxin, whether a postmortem increase in DLIS is detectable and whether sampling site can affect DLIS concentrations.

3 DLIS (measured as digoxin, TDx Abott) were determined in blood samples drawn antemortem from ICU patients; postmortem samples from femoral artery and cardiac chambers were taken at least 12 h after the death of these same patients.

4 DLIS concentrations ≥0.2 ng/ml were measured in 44 and 40% of patients antemortem and postmortem (femoral), respectively. No difference was found in DLIS levels between antemortem and postmortem femoral and cardiac samples. Age, ICU stay and postmortem sampling time did not affect the postmortem increase in DLIS. None of the levels was in the toxic range.

5 DLIS may be present after death and their concentration does not increase postmortem. The interpretation of postmortem digoxin concentrations that fall in the therapeutic range should be done cautiously; such measurable levels do not necessarily indicate misuse or malicious intent even in patients who had not been treated with the drug.
The selective cytotoxicity of cobra venom factor immunoconjugate on cultured human nasopharyngeal carcinoma cell line
Authors: Wang Xue-Min , Huang Shou-Jian
Published: July 2017

The selective cytotoxicity of a CVF immunoconjugate on human nasopharyngeal carcinoma cell line was reported. Cobra venom factor (CVF), a C3b-like glycoprotein, was linked to BAC5, a murine monoclonal antibody directed against a human nasopharyngeal carcinoma-associated membrane antigen, by a disulfide bond. The high affinity to cultured human nasopharyngeal cells (CNE2) and the complement activating potency retained in CVF immuno-conjugate. Although the equimolar concentration of BAC5 or CVF alone was harmless to CNE2 cells, the CVF immunoconjugate in the presence of fresh human serum exhibited selective cytotoxicity on CNE2 cells in a concentration- (IC50 3.07×10-7 mol/L) and time-dependent manner. No cytotoxicity occurred on either CNE1 (another human nasopharyngeal carcinoma cell line) or MGC-803 (human gastric carcinoma cell line) cells. Furthermore, direct lytic factor (DLF, cardiotoxin) separated from cobra venom, augmented CVF immunoconjugate-induced cytotoxicity significantly. These results indicate that the CVF immunoconjugate has complement-mediated selective cytotoxicity on CNE2 cells, which can be potentiated by DLF.