bluuebunny/crossref_metadata_2025 huggingface dataset:
Selecting the Project Teams’ Members. A Challenging Human Resources Management Process for Laboratory Research
Authors: Markaki Evangelia N. , Sakas Damianos P. , Chadjipantelis Theodoros
Published: November 2011

The aim of our paper is to focus on the way a project manager chooses the appropriate members of his team in order to develop hi - technological project for a laboratory research in different sectors (business, hi-technological, financial, societal, political). Our aim is to focus on the differences and the challenges that hi - technological project team members have in laboratory research.
Low Frequency Measurements in Amorphous Wire for Studying GMI Effect
Authors: Vourna Polykseni
Published: November 2011

When a soft ferromagnetic material is flown by an ac current and a magnetic field is applied at the same time, a major change of its impedance is occurred. The aim of this paper is to investigate the influence of low frequency (1KHz-12KHz) ac current and the applied magnetic field on an amorphous magnetic wire (Co68Fe4.35Si12.5B15) without glass coating. For this purpose an experimental configuration has been setup, based on a Wheatstone bridge which receives an ac input signal from a frequency generator. The output is connected to the amorphous wire wrapped with a coil supplied by a dc voltage for the generation of the magnetic field. The output voltage pulse is measured for two cases a) The value of ac frequency is changing while the value of dc voltage applied to the coil remains constant (the magnetic field remains unchanged) and b) the magnetic field is changing while the ac frequency remains constant to a predefined value. Experimental results of the first scenario showed that when the frequency is altered a non-linear increase of the ac signal is observed at the output which shows an increase of the GMI effect and is related to the non-linearity of the wire’s permeability. For the second scenario the results showed an increase of the output signal offset (voltage) which also indicates an increase of the GMI effect.
Correlation of Structural Characteristics of Low Carbon Ferritic Steel with Magnetic Properties
Authors: Mpalliou A.
Published: November 2011

The surface magnetic properties, namely Barkhausen noise and surface dc B-H loops and the microstructure of low carbon steel, namely electron back scattering diffraction, have been correlated in this paper, showing a good monotonic behavior.
Correlation of Microstructure to Macroscopic Magnetic Measurements on Electrical Steels
Authors: Vourna Polykseni , Ktena Aphrodite
Published: November 2011

Results of an experimental study of electrical steel annealed at 500, 600, 700 °C and subsequently cooled via quenching or air, are presented. The samples have been characterized with respect to their magnetic properties using Magnetic Barkhausen Noise (MBN) and major and minor loop (B-H) measurements. MBN increases slightly with the annealing temperature especially in the quenched samples. The B-H loops suggest that the prevalent magnetization reversal mechanism in the air cooled samples is domain wall propagation, while in the quenched samples non 180odomain rotation seems to be significant approaching the high induction region. Scanning Electron Microscopy studies show a more homogeneous texture after annealing which in the case of the quenched samples is accompanied by not fully formed grain boundaries and orientation along he easy axis
Investigation of Strain Sensing Capabilities of Amorphous Magnetostrictive Wires Embedded in Epoxy Resin
Authors: Christopoulos A.C. , Koulalis I. , Tsamasphyros G.J. , Kanderakis G.
Published: November 2011

The development of fibers and adhesive systems with high durability has recently led to the creation of a new repair method of metallic structures, by the use of reinforcing patches made of composite materials. This technique is generally reported as "Composite patch repair" and provides very important advantages compared to the conventional methods of repairs. On the other hand, the technology of induction heating constitutes an innovative approach to achieve the supply of energy for the curing of resins or for the manufacturing of composite materials. In the case of resins, a ferromagnetic material must be imported into the resin, to produce the required heat. This may be achieved by importing a metallic grid in the resin. Moreover, this metallic grid, which remains inside the resin after the curing, may serve as sensor by analyzing its electrostatic properties, thus providing useful information about the structural integrity of the area (e.g. potential increase of the crack below a bonded composite repair). In this paper we present results concerning the strain sensing capabilities of amorphous magnetostrictive wires embedded in epoxy resin. The inverse magnetostrictive effect leads to a change of permeability of wires so that applied stress can change the impedance of the amorphous wires due to the skin effect with alternating current excitation. Two different types of sensing were used, contact sensing (attachment of the wire “gauge” to a sensing devise) and induction sensing (eddy current sensing probe).
Fabrication of Carbon Nanotube/Low Density Polyethylene Composites for Strain Sensing
Authors: Chafy Radwa R. Abdel , Arafa Mustafa H. , Esawi Amal M. K.
Published: November 2011

Carbon Nanotubes (CNTs) have shown remarkable electrical, piezoresistive properties as well as other physical properties. The aim of this study is to investigate the potential of CNT-polymer composites in strain sensing using low density polyethylene (LDPE) polymer. Different CNT loadings were used (0, 1, 2, 3.5, 5, 6.5 and 8 weight %). CNT/LDPE composite films of 1mm thickness were fabricated using compression molding. The electrical resistance at no load condition was measured and the percolation behavior was obtained. The percolation threshold was found to be in the range of (2-5) wt%, where a decrease in resistivity by 5 orders of magnitude was observed. The sensitivity (gauge factor – GF) of the films was evaluated by correlating the strain applied with the simultaneously measured resistance. For a strain range of up to 320 µε, a gauge factor of 200 was achieved at a CNT loading of 5 wt%.
Fabrication of Porous Layer on the Nondoped Amorphous SiC Thin Film by Anodic Etching Method in HF/H2O/H2O2
Authors: Cao D. T. , Tuan-Anh C. , Quynh-Ngan L. T. , Anh N. H. , Nga Pham Thu
Published: November 2011

Due to the inertness of the intrinsic (nondoped) amorphous SiC (i-aSiC) material to the chemical impact, for making it porous by the electrochemical etching method, one must use the electrolyte solution with an appropriate composition. For this purpose we have found that besides the use of solutions containing surface activation agent (Triton X-100 for example), one can use also solutions containing oxidation agent. In this report we present the results obtained with electrolyte solution in which H2O2 plays the role of oxidation agent. Results showed that with appropriate ratio of components in the HF/H2O/H2O2 solution, we can manufacture a porous layer in the i-aSiC thin film with the porosity similar to the porosity of the porous layer obtained by etching in the HF/H2O/Triton X-100 solution with optimal composition. Thin film of i-aSiC material with porous surface layer can be used in different types of sensors.
Optical Electronic Nose Based on Fe (III) Complex of Porphyrins Films for Detection of Volatile Compounds
Authors: Umar Akrajas Ali , Salleh Muhamad Mat , Yahaya Muhammad
Published: November 2011

Electronic nose is a device that attempts to mimic the living being smell system for detection of particular gases or volatile compounds. This paper reports the development of an optical electronic nose using Fe (III) based metalloporphyrins Langmuir-Blodgett thin films as sensing elements for discriminating four volatiles, 2-propanol, acetone, cyclohexane and ethanol. A multilayer feed forward neural network was developed to classify the input vectors from these two sensors. After the network being trained 100 times and introduced to blind samples, it was found that there are three fault decision for propanol, two for acetone, five for cyclohexane and one four ethanol, during 50 times being recognized to the samples.
Detection of Formaldehyde Using Plasmonic Properties of Gold Nanoparticles
Authors: Nengsih Sri , Umar Akrajas Ali , Salleh Muhamad Mat , Yahaya Muhammad
Published: November 2011

This paper reports a study on plasmonic properties of gold nanoparticles to detect the presence of formaldehyde solution in water. Gold nanoparticles were grown on substrates by the seed mediated growth method. A sensor system was setup, comprises a light source, a dual arm fibre optic probe, a spectrometer and sensor chamber. The detection of formaldehyde was done by comparing the Localized Surface Plasmon Resonance (LSPR) spectra of gold nanoparticles samples immersed in the deionised water and formaldehyde solution. It was observed that the peak position LSPR spectra of nanogold samples and their intensity were change by the presence formaldehyde. The difference between resonance peak intensity of LSPR spectra gold nanoparticles sample in formaldehyde solution and water can be used as sensing sensitivity parameter of the sensor. It was found that the sensing sensitivity is increase with the size of nanoparticles until it reach the optimum particles size.
Map Building System for Unmanned Ground Vehicle
Authors: Typiak Andrzej , Gnatowski Michał
Published: November 2011

A typical unmanned and remotely operated vehicle is usually equipped with cameras which give insufficient information about the nearest environment and an operator has difficulties in driving such a vehicle in unknown environment. In this paper, we consider a problem of the vehicle nearest area map building based on additional devices. The vehicle is equipped with SICK LMS lasers, inclinometer and radars. Combining information from the devices allows to build a map which helps an operator to drive the vehicle more efficiently. We tested the system on a few military vehicles and the results show that our system really improves remotely driving.
Application of the Maggi Equations to Mathematical Modeling of a Robotic Underwater Vehicle as an Object with Superimposed Non-Holonomic Constraints Treated as Control Laws
Authors: Ladyżyńska-Kozdraś Edyta
Published: November 2011

Based on torpedoes, a universal mathematical model of a robotic underwater vehicle comprising coupling dynamics of a controlled object with superimposed guidance has been built. Using control laws as kinematic correlation of deviation from pre-defined parameters of ideal control, the control laws have been tied to the dynamic equations of motion.
Data Dimension Reduction and Visualization with Application to Multi-Dimensional Gearbox Diagnostics Data: Comparison of Several Methods
Authors: Bartkowiak Anna , Zimroz Radoslaw
Published: November 2011

In recent years we face the growing interest in building automated diagnosis systems detecting ‘normal’ or ‘abnormal’ functioning of a system. But little is known about the distribution and shape of the data describing 'normal' functioning. The shape of the data is of paramount importance in determining the mathematical model of the data serving for the diagnosis. We got real industrial data by gathering vibration signals of a gearbox working in a mine excavator operating in time-varying conditions. The main considered problems are: what is the shape of the recorded 15-dimensional data and what kind of outliers may be found there? We have used for this purpose pseudo grand tour, PCA and simple auto-associative neural network. The methods used proved to be very effective in answering our questions.
Conception and Practical Application of a Measuring Device for Energetic Parameters Measurement of a Mechatronic Object
Authors: Cwalina Aleksy , Zacharewicz Marcin
Published: November 2011

In the article assumptions of the developed non-invasive method of evaluation technical condition of selected structural elements of the ship's diesel-electric set at limited monitoring susceptibility, when the engine is not equipped with indicator valves, are discussed. The method is based on simultaneous measurements of phase-to-phase voltage of the synchronous generator, exhaust gas pressures in the exhaust manifold, and vibration accelerations of some parts of the set. To the purpose of the accomplishment all measurements of energetic parameters at the same time, it turned out to be necessary to design and construct the measured quantity converter. In the paper requirements in relation to such a converter, technical project, and representative results of measurements conducted on a real object – diesel-electric set type ZE400/52 – are presented.
Modelling of the Toothed Gear Operations with the Application of the Analysis of the Gear Sliding Mesh Velocity Changes
Authors: Dziurdź Jacek
Published: November 2011

Searching for effective diagnostic methods of basic elements of driving systems is still the actual problem. The most often the vibroacoustic diagnostics based on the analysis of vibrations and noises generated by the working system is applied. Driving systems of vehicles are rather complicated. They consist, among others, of various types of toothed gears. Within the vibroacoustic signals recorded during their operation not only harmonic components – being the effect of these gears operations - are present, but also components generated by other elements. Due to this, there is a necessity of the development of models of the vibroacoustic signals generation by the main elements of the driving system. Such models will allow to identify – within the recorded signals – the harmonic components related to processes occurring during the gear operation. These models should be relatively simple due to the possibility of their application in diagnostic devices operating in the ‘on line’ mode. Modelling of the single-stage toothed gear, with the application of the analysis of the gear sliding mesh velocity changes, is presented in the hereby paper.
Identification of Destructive Processes Affecting Hydraulic Servomechanisms of the Aircraft Control Assist System
Authors: Ułanowicz Leszek
Published: November 2011

The paper presents identification of destructive processes that affect hydraulic servomechanisms of the aircraft control assist system and influence of these processes onto values of parameters that characterize structures and operation of these systems. Particular attention is paid to the description of essential properties attributable to operation of the distributing device within a hydraulic servomechanism with a spotlight to physical background of the process when friction equilibrium of a sliding hydraulic pair is disturbed, which leads to its destruction. More specifically the issue associated with violation of friction stability in a cylindrical, sliding hydraulic pair due to the impact of an unbalanced radial hydrostatic force as well as material contamination and a hydrodynamic axial force. Qualitative assessment of unbalanced radial forces are carried out for the case when cylindrical slider is placed inside a guiding sleeve with consideration of various positions of the slider against the sleeve. Consequently, a set of parameters was found out with the aim to characterize operation quality (dependability) of a hydraulic servomechanism. Finally, characteristics of a hydraulic servomechanism with a linear distributing slider or a rotary slider have been developed as a function of their lifetime.
Modelling and the Elements of Controlled Dynamics of the Anti-Aircraft Missile Launcher Based Onboard the Warship
Authors: Dziopa Zbigniew , Koruba Zbigniew
Published: November 2011

The paper presents a physical and mathematical model of the controlled anti-aircraft launcher based onboard the ship, whose aim is to fight low-flying air targets. Selected tests results of the computer simulation are presented in a graphic form.
The Optimal and Safe Ship Trajectories for Different Forms of Neural State Constraints
Authors: Lisowski Józef
Published: November 2011

The paper introduced the dynamic programming algorithm of own ship optimal and safe trajectory in situation a many of encountered objects. The moving domains of met objects are introduced as neural state constraints in the form of circle, parable, ellipse and hexagon. Finally the computer simulation of multistage own ship control in real navigational situations at sea is presented.
Study of Infrared Imaging System Based on Liquid-Crystal Thermo-Optic Effect
Authors: Zhang Ya , Cai Chang Long , Niu Xiao Ling , Liu Wei Guo
Published: November 2011

In this paper, based on the optical rotation property of cholesteric liquid crystals, a new system for studying the optical readout infrared imaging was designed. The profile of hot object is imaged on the surface of liquid crystal cell through the infrared lens, as the uneven heating, the optical rotation is different in various parts of the cholesteric liquid crystals, especially in the imaging area and non-imaging area, the difference is larger. Through the optical system, the optical rotation signal is translated into the corresponding light intensity signal, then the light intensity signal is collected by the visible CCD, and the image of the hot object will be displayed on the screen.
Synthesis and Property of Liquid Crystal Polymers Containing Photosensitive Groups
Authors: Li Ji Lei , Zhang Wei Min , Zhao Yu Lei , Pu Jia Ling
Published: November 2011

The synthesis and free-radical polymerization of the acrylates monomer containing photosensitive chalcone group and the acrylates monomer containing mesogenic group are described in this paper. The monomers and polymers were characterized by FT-IR and 1 H NMR spectra. The thermal properties of polymers were measured by DSC and the liquid crystalline texture was measured by POM. And the results indicated that the polymers showed typical nematic phase and liquid crystal temperature range was 74 °C-103 °C.
Synthesis and Mesophases Study on 2-(8-bromooctanoic acid ester)-3,6,7,10,11-penta-pentyloxytriphenylene
Authors: Zhang Ming Xia , Zhang Chun Xiu , Pu Jia Ling , Wu Hao , Fang Gui Sen
Published: November 2011

A novel triphenylene-based discotic liquid crystal compound 2-(8-bromooctanoic acid ester)-3,6,7,10,11-penta-pentyloxytriphenylene was synthesized in this study.The chemical structure of the compound was characterized by1HNMR spectra, FT-IR spectra and we confirmed its structure. The mesophases were investigated by using different scanning calorimetry DSC and polarizing optical microscopy POM, the results showed that the target product had Liquid crystal properties and the temperature range of 90-101 °C, and showed a clear columnar phase. The carrier transport mobility was measured using time-of-flight TOF method, μ=1.09*10-2cm2V-1s-1.
One-Step Synthesis of a Liquid Crystal TB4A at Room Temperature
Authors: Ma Qing Lan , Zhai Bao Gai , Huang Yuan Ming
Published: November 2011

A rod-like liquid crystal (LC) N,N-(terephthalylidene) bis (4-n-butylaniline) (TB4A) was synthesized by one step at room temperature. The synthesized TB4A were investigated with nuclear magnetic resonance, fourier transform infrared spectrometer and ultraviolet-visible spectrophotometry, differential scanning calorimetry and polarizing optical microscopy. Our results demonstrated that the TB4A can form nematic, smectic A, smectic C, smectic F and smectic G LC phases.
Synthesis and Characterization of Poly (L-Lactic acid) Containing the Azobenzene Mesogens
Authors: Dong Run Tao , Xue Qing Bin , Sun Ling Min , Zhang Quan Xuan
Published: November 2011

A series of azobenzene containing group Poly (L-lactic acid) (PLLA) were synthesized by Ring-Opening Polymerization of L-lactide (L-LA) catalysted by Sn (Oct)2initiated by alcohol-OH containing the azobenzene chromophores. Their molecular weights were well controlled by the feed ratio as characterized by Gel Permeation Chromatography (GPC) and1H NMR Spectrometry and agreed well with theoretical values. The thermal properties and liquid crystal phases were investigated by Differential Scanning Calorimetry (DSC), polarized optical microscopy (POM) and X-ray Diffraction (XRS) measurements. Cis-trans photoisomerization behavior of the polymers in the solutions and the films were studied with UV irradiation. By the Circular Dichroism Spectroscopy (CD) characterization of the solutions and films of the polymer, the PLLA segments show huge optical rotation power in helical structure.
Phase Diagram of Thermotropic Liquid Crystal Including Negative Pressure Region Generated in Metal Berthelot Tube
Authors: Hiro Kazuki , Wada Tadahiro
Published: November 2011

Phase diagrams including absolute negative pressure regions of thermotropic liquid crystals give useful information on science and technology. A phase diagram was depicted for ca. 40mg of a thermotropic liquid crystal in a pressure vs. temperature (P-T) plane by the Berthelot method using a metal tube. N-I phase transitions occurred even under-10MPa, and a polymorphism of the crystalline phase was observed.
Digital High Resolution Small Pixel LCOS Technology
Authors: Cheng Dennis , Fung Dixon , Guttag Karl
Published: November 2011

The progress in digital high resolution, small pixel liquid crystal on silicon (LCOS) microdisplays will be discussed and how it will lead to HD displays in very small form factors. The first generation of this technology is enabling very small yet high resolution projection engines devices that can be embedded in cell phones, cameras, head-mount displays, and set-top boxes and the next generation will bring HD resolution. As lasers become more affordable we see this LCOS display technology fundamentally changing the power consumption, cost, and size of pico-projectors and other display devices. One of the most interesting conclusions is that by using LCOS technology in combination with lasers, it should soon be possible to build an “ultra-green” television that would consume less than 1/8th the power of equivalent size LCD flat panel TV.
Synthesis and Electrochromic Properties Based on Star-Shaped Oligothiophene Derivatives with Phenyl Core
Authors: Guan Li , Zhao Xue Quan , Zhong Yi Ping , Liu Ping , Deng Wen Ji
Published: November 2011

For the purpose of developing novel electrochromic materials, star-shaped oligothiophene derivatives with phenyl core, 1,3,5-tris (2′-thienyl) benzene (3TB) and 1,3,5-tris (5′-(2,2′- bithienyl)) benzene (3BTTB) were synthesized, and their electrochromic properties were investigated. It was found that 3TB and 3BTTB as solid films showed reversible, clear color changes on electrochemical doping and dedoping. The two oligothiophene derivatives with phenyl core constitute a new class of potential electrochromic materials.
Effect of Photo-Isomerization of Azo Dyes on the Photonic Bandgap in Chiral Nematics
Authors: Statman David , Jockers Andrew , Brennan Daniel
Published: November 2011

Chiral nematic liquid crystals prepared with Grandjean texture demonstrate a photonic bandgap whose central wavelength is proportional to the pitch length, P, of the liquid crystal and whose width is given by (ne – no)P. We show that methyl red doped chiral nematics undergo a shift in the photonic bandgap upon photo-isomerization. This shift is a result of (1) photo-induced change in anchoring energy on the nematic surface, and (2) change in the natural pitch length from the photo-isomerization of the azo dye.
Tunable Optical Filter with Variable Bandwidth Based on Cholesteric Liquid Crystal
Authors: Zhang Shi Chao , Huang Yu Hua
Published: November 2011

An optical tunable filter with variable bandwidth has been demonstrated using two cholesteric liquid crystals. The incident light was first reflected by the first cholesteric liquid crystal and then by the second one. By rotating the two cholesteric liquid crystals simultaneously, the central wavelength can be tuned. By fixing one of the cholesteric liquid crystals and rotating the other one, the bandwidth of the tunable filter can be varied. The central wavelength of the tunable optical filter can be tuned from 513.4 nm to 576.8 nm and the bandwidth is varied from 10 nm to 80 nm. This property will allow it to be widely used in many fields, including optical communications and multispectral and hyperspectral imaging systems.
Structure and Magnetic Properties of Co2.73Fe0.27O4 Synthesized by the Heat-Decomposition Method
Authors: Gan Zhang Hua , Guo Jun Bo , Liu Jing , Lu Zhi Hong
Published: November 2011

Co2.73Fe0.27O4 nanoparticles were synthesized using the heat-decomposition method followed by annealing treatment. X-ray diffraction (XRD) analysis shows that most of the peaks are close to the data for antiferromagnetic Co3O4, while weak peaks of CoFe2O4 are also detected. It indicates that the prepared particles can be reckoned as a composite with a small size of the FM particles embed in a large thickness of the AFM matrix. The magnetic hysteresis loops of Co2.73Fe0.27O4 powders were measured at 10 K by using the zero-field cooling (ZFC) and field cooling (FC) procedures and show negative and downward shifts, and the shifts finally disappear when temperature increases to 200 K. We suggest that exchange bias effect in Co2.73Fe0.27O4 is mainly related with the exchange interactions at the interfaces between the FM CoFe2O4 nanoparticles and the frozen spins around them.
Electron Mobility Model of Strained Si1-xGex(001)
Authors: Hu Hui Yong , Lei Shuai , Zhang He Ming , Xuan Rong Xi , Shu Bin
Published: November 2011

Solving the Schrödinger equation with strain Hamiltonian and combining with KP theory, we obtained the conductivity effective mass and density of states effective mass of strained Si1-xGex(001) in this paper. On the basis of conductivity effective mass and density of states effective mass, considered of Fermi golden rule and Boltzman collision term approximation theory, scattering rate model was established in strained Si1-xGex(001). Based on the conductivity effective mass and scattering rate models we discussed the dependence of electron mobility on stress and doping concentration in strained Si1-xGex(001), it shows that electron mobility decrease with the increasing of stress and doping concentration. This result can provide valuable references to the research of electron mobility of strained Si1-xGexmaterials and the design of devices.
Crystal Structure and Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Pr3+ Substitution at A-Site
Authors: Xiong Gang
Published: November 2011

Crystal structure and microwave dielectric properties of (Ca1-xPrx) [(Li1/3Nb2/3)0.95Zr0.15]3+δ (0.0≤x≤0.2, CPLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x=0.0~0.08. With an increase of Pr3+ content, the quality factor value firstly increased, and then began to decrease at x=0.06 due to a decrease of the degree of B-site 1:2 ordering. The variation of τf with tolerance factor was discussed. When x=0.06, the optimum microwave dielectric properties: the permittivity is 33.2, the quality factor is 17120 GHz，and the temperature coefficient of resonator frequency is −5.7×10−6/°C.
Phase Morphology and Rheology Behaviors of PTT/POE/OMMT Nanocomposites
Authors: Run Ming Tao , Qi Zi Yu , Yao Meng , Zhou Wen , Xing Bing Tao
Published: November 2011

The phase morphology and dynamic rheology of poly (trimethylene terephthalate)/maleinized poly (octene-ethylene)/organo-montmorillonite nanocomposites were investigated by using transmission electron microscopy (TEM) and rotational rheometer. The results suggest that some of the OMMT are peeled off and the nanosheets are dispersed evenly in the polymer matrix. When the OMMT content is more than 4%, they are tended to form the aggregates in nanocomposites. The nanocomposites’ melt are pseudo-plastic fluid, and both complex viscosity and shear storage modulus increase with increasing OMMT content due to the interaction between the OMMT and polymers. The nanocomposites’ melt show more elasticity behavior with more OMMT content especially at low shear frequencies.
Study of Blue-Phase III–Isotropic Phase Transition
Authors: Wang Ru Zheng , Liu Jian Jun , Li Hui Li
Published: November 2011

In this paper, using the theories of Bogolyubov-Hellman-Feynman (BHF) and mean-spherical approximation, we get the system free energy within the four-order self-consistent cumulant expansion. According to the conditions of equilibrium state and self-consistent equation, we obtain the relation between reduced temperature and inverse correlation length and disscuss that the cubic invariant item is important in explaining BPIII to isotropic transition.
OPTIMIZACIJA IZBORA KONCEPCIJE POSTROJENJA MALE HIDROELEKTRANE NA UNAPRIJED UTVRĐENOJ MAKROLOKACIJI METODOM VIŠEKRITERIJALNOG RANGIRANJA - Teoretske osnove
Authors: Milovanović Zdravko , Knežević Darko , Milašinović Aleksandar , Dumonjić-Milovanović Svetlana
Published: November 2011

U radu se razmatra problem definisanja optimalne koncepcije realizacije objekta MHE sa aspekta izbora varijante u okviru već definisanog prostora. Za izabrane kvalitativne i kvantitativne karakteristike određuju se relativni težinski koeficijenti kombinacijom AHP (Analitical Hierarchial Process), Saatyeve skale i primarno defininisanih vrijednosti parametara. U konkretnom problemu razmatra se više alternativa, koje su definisane kvalitativnim kriterijumima i sa nepreciznim vrijednostima što navodi na ideju da se postojeće višekriterijalne metode prilagode rješavanju takvih problema rangiranja alternativnih rješenja u smislu postepenog smanjenja polaznih više kriterijuma. Prvi dio rada predstavlja kratki pregled teoretskih osnova
IZVORIŠTE PRIRODNE IZVORSKE VODE „NEVRA“, DEŽEVICE KOD KREŠEVA
Authors: Skopljak Ferid
Published: November 2011

Izvorište prirodne izvorske vode „Nevra“ se nalazi na padinama Bitovnje planine koja zajedno sa drugim visokim planinama Vranice pripada „srednjebosanskom škriljavom gorju“ u središnjim Dinaridima Bosne i Hercegovine. U ovim planinama sa alpskom klimom i visinama preko 2.000 metara sudaraju se hladne sjeverne i tople mediteranske struje što omogućava obaranje izuzetno velike količine padavina, i uz povoljne hidrogeološke karakteristike terena uzrokuje formiranje veoma vodoobilnih akumulacija podzemnih voda, pojavu velikog broja izvora i održivost vodnog potencijala u ovom području. U geološkoj građi ovih terena učestvuju nepropusne metamorfne i magmatske stijene starijeg paleozoika, te krečnjaci i dolomiti devona u kojima je formiran akvifer koji se prazni na izvoru „Nevra“. Kvalitet vode izvora „Nevra“ je besprijekoran i konstantan tokom cijele hidrološke godine, kako u kemijskom tako i bakteriološkom pogledu, izdašnosti 20 l/s. Mineralizacija vode od oko 160 mg/l i temperatura vode na izvoru od 6 oC „Nevru“ uvrštava u red najprestižnijih voda koje nalazimo na svjetskim tržištima. Imajući u vidu kvalitet i kapacitet izvorišta „Nevra“ bespotrebno je da Bosna i Hercegovina uvozi, velike količine flaširane vode iz inostranstva, pri čemu se odlivaju značajna finansijska sredstva, destabilizira ekonomski prosperitet naše zemlje, te ograničavaju investicije, istraživanja i razvoj u sektoru voda, kada se raspolaže velikim bogatstvom ovako kvalitetnih podzemnih voda.
Fluorinated Zinc Phthalocyanine as Donor for Efficient Vacuum‐Deposited Organic Solar Cells
Authors: Meiss Jan , Merten Andre , Hein Moritz , Schuenemann Christoph , Schäfer Stefan , Tietze Max , Uhrich Christian , Pfeiffer Martin , Leo Karl , Riede Moritz
Published: November 2011

Efficient single bulk heterojunction organic solar cells based on blends of a fluorinated zinc phthalocyanine as electron donor and fullerene C60 as electron acceptor are reported. In comparison to the commonly used absorber zinc phthalocyanine, the fluorination of the molecule to F4ZnPc leads to an increase in ionisation potential and subsequently to an improvement of about 170 mV in the open circuit voltage of organic solar cells, while the short circuit current density and fill factor remain nearly unchanged. Similar to ZnPc:C60‐based devices, the device characteristics of F4ZnPc:C60 solar cells can be further enhanced by improving the blend layer morphology by substrate heating during deposition. F4ZnPc is an efficient donor material that can achieve a 4.6% power conversion efficiency in single heterojunction organic solar cells.
Mechanical Properties of Poly(vinylidene fluoride) Nanofiber Filaments Prepared by Electrospinning and Twisting
Authors: Nakashima Ryu , Watanabe Kei , Lee Yujin , Kim Byoung‐Suhk , Kim Ick‐Soo
Published: November 2011

In this study, we propose a novel method for preparing a continuous filament using electrospinning and twisting methods to improve the mechanical properties of nonwoven poly(vinylidene fluoride) (PVDF) nanofibers. The morphologies of the nonwoven nanofiber membranes and the corresponding nanofiber filaments were investigated by scanning electron microscopy. The mechanical properties and crystal structure of both the nanofiber membranes and the nanofiber filaments were investigated by using a universal testing machine and wide‐angle X‐ray diffraction (WAXD), respectively. We found that the tensile strength and Young's modulus of nanofiber filaments were dramatically improved by increasing either the number of twists of the nanofibers or the width of nanofiber membranes, compared with nonwoven PVDF nanofibers. WAXD analysis indicated that the crystalline transformation from β‐phase to α‐phase occurred by the shear force driven by repeated twisting. It was concluded that both the crystalline structures of fibers and the fiber morphologies played a crucial role in the mechanical properties of the resultant nanofiber filaments. © 2011 Wiley Periodicals, Inc. Adv Polym Techn 32: E44–E52, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20268
Ähnlichkeiten und Unterschiede innerhalb der “relativistischen” Triade Gold, Platin und Quecksilber in der Katalyse
Authors: Leyva‐Pérez Antonio , Corma Avelino
Published: November 2011

Relativistische Effekte in der Valenzschale der chemischen Elemente treten innerhalb der Triade Pt–Au–Hg am stärksten hervor, und sie bestimmen die katalytische Aktivität von Komplexen dieser Elemente in organischen Reaktionen. Wir vergleichen in diesem Aufsatz die katalytische Aktivität von Pt‐, Au‐ und Hg‐Verbindungen in repräsentativen Reaktionen und diskutieren die jeweiligen Vor‐ und Nachteile, auch mit Blick auf Eigenschaften wie Giftigkeit, Preis und Verfügbarkeit. In den betrachteten Reaktionen sind Gold‐Katalysatoren im Allgemeinen aktiver als Quecksilber‐ oder Platin‐Katalysatoren.
Identification of novel neutralizing single‐chain antibodies against vascular endothelial growth factor receptor 2
Authors: Erdag Berrin , Koray Balcioglu B. , Ozdemir Bahadir Aylin , Serhatli Muge , Kacar Omer , Bahar Aydin , Seker Urartu O. S. , Akgun Emel , Ozkan Abdulkadir , Kilic Turker , Tamerler Candan , Baysal Kemal
Published: November 2011

Human vascular endothelial growth factor (VEGF) and its receptor (VEGFR‐2/kinase domain receptor [KDR]) play a crucial role in angiogenesis, which makes the VEGFR‐2 signaling pathway a major target for therapeutic applications. In this study, a single‐chain antibody phage display library was constructed from spleen cells of mice immunized with recombinant human soluble extracellular VEGFR‐2/KDR consisting of all seven extracellular domains (sKDR D1–7) to obtain antibodies that block VEGF binding to VEGFR‐2. Two specific single‐chain antibodies (KDR1.3 and KDR2.6) that recognized human VEGFR‐2 were selected; diversity analysis of the clones was performed by BstNI fingerprinting and nucleotide sequencing. The single‐chain variable fragments (scFvs) were expressed in soluble form and specificity of interactions between affinity purified scFvs and VEGFR‐2 was confirmed by ELISA. Binding of the recombinant antibodies for VEGFR‐2 receptors was investigated by surface plasmon resonance spectroscopy. In vitro cell culture assays showed that KDR1.3 and KDR2.6 scFvs significantly suppressed the mitogenic response of human umbilical vein endothelial cells to recombinant human VEGF165 in a dose‐dependent manner, and reduced VEGF‐dependent cell proliferation by 60% and 40%, respectively. In vivo analysis of these recombinant antibodies in a rat cornea angiogenesis model revealed that both antibodies suppressed the development of new corneal vessels (p < 0.05). Overall, in vitro and in vivo results disclose strong interactions of KDR1.3 and KDR2.6 scFvs with VEGFR‐2. These findings indicate that KDR1.3 and KDR2.6 scFvs are promising antiangiogenic therapeutic agents.
Medication‐assisted Treatment Research with Criminal Justice Populations: Challenges of Implementation
Authors: Gordon Michael S. , Kinlock Timothy W. , Miller Patrice M.
Published: November 2011

Creating, implementing and evaluating substance abuse interventions, especially medication‐assisted treatments, for prisoners, parolees, and probationers with histories of heroin addiction is an especially challenging endeavor because of the difficulty in coordinating and achieving cooperation among diverse criminal justice, substance abuse treatment, research, and social service agencies, each with its own priorities and agenda. In addition, there are special rules that must be followed when conducting research with criminal justice‐involved populations, particularly prisoners. The following case studies will explore the authors' experience of over 10 years conducting pharmacotherapy research using methadone, buprenorphine, and naltrexone with criminal justice populations. The major obstacles and how they were overcome are presented. Finally, recommendations are provided with regard to implementing and conducting research with criminal justice populations. Copyright © 2011 John Wiley & Sons, Ltd.
Multilayer thin films of colloidal gold and silica nanoparticles: Effect of polyelectrolyte coating
Authors: Khan Zaheer Abbas , Kumar Rachana , Dutta Joydeep
Published: November 2011

The use of oppositely charged colloidal nanoparticles to build multilayered structures is an approach in thin film science. In this work, uniform spherical nano‐dispersions of gold (ca. 20 nm) and silica (ca. 30 nm) were synthesised with specific volume concentration to achieve colloidal stability. Exploiting the use of self‐assembly, multilayers of these oppositely charged nanoparticles were built using alternate coating with chitosan. Gold nanoparticles have strong optical absorption in visible region of electromagnetic spectrum resulting from its surface plasmon resonance. Silica nanoparticles have low refractive index and absorb light mostly in the ultraviolet (UV) region. The optical absorption band of the fabricated thin films extends from UV to visible region of the electromagnetic spectrum. The spectral characteristics of these thin‐film assemblies are a combination of thickness and the order of the layers in a stack. These films have potential applications as optical elements and in optoelectronics. © 2011 Canadian Society for Chemical Engineering
Prolonged impact of chemotherapy on fatigue in breast cancer survivors
Authors: Goedendorp Martine M. , Andrykowski Michael A. , Donovan Kristine A. , Jim Heather S. , Phillips Kristin M. , Small Brent J. , Laronga Christine , Jacobsen Paul B.
Published: November 2011

BACKGROUND:

In this study, the authors examined the influence of prior treatment on the course of fatigue in breast cancer survivors. Patients who received chemotherapy were expected to have greater fatigue than patients who received radiotherapy and noncancer controls 6 months after the completion of treatment, but they were expected to recover to levels similar to those of the other 2 groups 3 years later.

METHODS:

Patients with stage 0 through II breast cancer completed the Fatigue Symptom Inventory (FSI) and the Profile of Mood States Fatigue Scale (POMS‐FAT) 6 months (T1) and 42 months (T2) after completing chemotherapy with or without radiotherapy (the CT group; n = 103) or radiotherapy only (the RT group; n = 102). An age‐matched group of women with no history of cancer (the NC group; n = 193) was assessed over a similar interval.

RESULTS:

A significant (P = .041) group × time effect for FSI severity scores revealed that fatigue worsened over time in the CT group but remained stable and lower in the RT and NC groups. There also were significant group effects for FSI days (P < .001) and POMS‐FAT (P = .010) scores, indicating that fatigue was significantly greater across time in the CT group than in the NC group (POMS‐FAT) or the RT and NC groups (FSI days).

CONCLUSIONS:

Contrary to expectations, fatigue did not diminish over time in patients with breast cancer who received chemotherapy. This finding has important implications for patient education and for fatigue monitoring during follow‐up. The authors concluded that future research should seek to examine possible mechanisms to explain the apparent prolonged impact of chemotherapy on fatigue in breast cancer survivors. Cancer 2012. © 2011 American Cancer Society.
Mechanisms of resistance to vascular endothelial growth factor blockade
Authors: Abdullah Shaad E. , Perez‐Soler Roman
Published: November 2011

Angiogenesis is essential for the growth of primary tumors and for their metastasis. This process is induced by factors, such as vascular endothelial growth factors (VEGFs), that bind to transmembrane VEGF receptors (VEGFRs). VEGF‐A is the primary factor involved with angiogenesis; it binds to both VEGFR‐1 and VEGFR‐2. The inhibition of angiogenesis by obstructing VEGF‐A signaling has been investigated as a method to treat solid tumors, but the development of resistance to this blockade has complicated treatment. The major mechanisms of this resistance to VEGF‐A blockade include signaling by redundant receptors, such as the fibroblast growth factors, angiopoietin‐1, ephrins, and other forms of VEGF. Other major mechanisms of resistance are increased metastasis of hypoxia‐resistant tumor cells, recruitment of cell types capable of promoting VEGF‐independent angiogenesis, and increased circulation of nontumor proangiogenic factors. Additional mechanisms of resistance to VEGF‐A blockade include heterogeneity of responsiveness among tumor cells, use of anti‐VEGF‐A agents at insufficient doses or for insufficient duration, altered sensitivity to anti‐VEGF‐A agents by mutations in endothelial cells or vascular remodeling, maintenance of vascular sleeves that allow for easy regrowth of tumor vasculature upon discontinuation of therapy, vascular cooption, and intussusceptive angiogenesis. An understanding of these mechanisms may lead to the development of targeted therapies that overcome this resistance. Some of these approaches include the combined inhibition of redundant angiogenic pathways, proper patient selection for various therapies based on gene expression profiles, blockade of cellular migration by inhibition of colony‐stimulating factor, or the use of agents to disrupt vascular architecture. Cancer 2012;3455–3467. © 2011 American Cancer Society.
Risk assessment models for cancer‐associated venous thromboembolism
Authors: Dutia Mrinal , White Richard H. , Wun Ted
Published: November 2011

Venous thromboembolism (VTE) is common in cancer patients, and is associated with significant morbidity and mortality. Several factors, including procoagulant agents secreted by tumor cells, immobilization, surgery, indwelling catheters, and systemic treatment (including chemotherapy), contribute to an increased risk of VTE in cancer patients. There is growing interest in instituting primary prophylaxis in high‐risk patients to prevent incident (first‐time) VTE events. The identification of patients at sufficiently high risk of VTE to warrant primary thromboprophylaxis is essential, as anticoagulation may be associated with a higher risk of bleeding. Current guidelines recommend the use of pharmacological thromboprophylaxis in postoperative and hospitalized cancer patients, as well as ambulatory cancer patients receiving thalidomide or lenalidomide in combination with high‐dose dexamethasone or chemotherapy, in the absence of contraindications to anticoagulation. However, the majority of cancer patients are ambulatory, and currently primary thromboprophylaxis is not recommended for these patients, even those considered at very high risk. In this concise review, the authors discuss risk stratification models that have been specifically developed to identify cancer patients at high risk for VTE, and thus might be useful in future studies designed to determine the potential benefit of primary thromboprophylaxis. Cancer 2012;3468–3476. © 2011 American Cancer Society.
Summary of ‘Interventions for treating scabies’
Authors: Editorial Office Evidence‐Based Child Health
Published: November 2011

This is a summary of Cochrane review, published in this issue of EBCH, first published as: Strong M, Johnstone P. Interventions for treating scabies. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD000320. DOI: 10.1002/14651858.CD000320.pub2 Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
Summary of ‘Different powered toothbrushes for plaque control and gingival health’
Authors: Editorial Office Evidence‐Based Child Health
Published: November 2011

This is a summary of Cochrane review, published in this issue of EBCH, first published as: Deacon SA, Glenny AM, Deery C, Robinson PG, Heanue M, Walmsley AD, Shaw WC. Different powered toothbrushes for plaque control and gingival health. Cochrane Database of Systematic Reviews 2010, Issue 12. Art. No.: CD004971. DOI: 10.1002/14651858.CD004971.pub2. Copyright © 2011 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration
Wet air oxidation of oily sludge using Ni2+ catalyst
Authors: Jing Guolin , Luan Mingming , Chen Tingting
Published: November 2011

This work studied the feasibility of treating oily sludge by means of wet air oxidation (WAO) at high temperatures. The effect of the operating conditions on COD removal of the oily sludge, including temperature, the initial COD of the oily sludge, residence time, concentration of catalyst, and O2 excess (OE), was studied. WAO has been proved to be a very efficient technology for the treatment of those residual currents, resulting in destruction efficiencies of greater than 80% of initial COD. Adding a catalyst significantly improved the COD removal. Homogenous catalyst, Ni2+, showed effective removal for pollutants. COD removal was 97.8% in the catalytic wet air oxidation (CWAO) over Ni2+ catalyst. The results proved that the CWAO was an effective pretreatment method for the oily sludge. © 2011 American Institute of Chemical Engineers Environ Prog, 32: 99–102, 2013.
ARE ANCHORING VIGNETTES RATINGS SENSITIVE TO VIGNETTE AGE AND SEX?
Authors: Jürges Hendrik , Winter Joachim
Published: November 2011

Anchoring vignettes are commonly used to study and correct for differential item functioning and response bias in subjective survey questions. Self‐assessed health status is a leading example. A crucial assumption of the vignette methodology is ‘vignette equivalence’: The health status of the person described in the vignette must be perceived by all respondents in the same way. We use data from a survey experiment conducted with a sample of almost 5000 older Americans to validate this assumption. We find weak evidence that respondents' vignette ratings may be sensitive to the sex and, for older respondents, also to the age (implied by the first name) of the person described in the vignette. Our findings suggest that vignette equivalence may not hold, at least if the potentially subtle connotations of vignette persons' names are not fully controlled. Copyright © 2011 John Wiley & Sons, Ltd.