bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimised separation procedures for the simultaneous assay of three plant hormones in liquid biofertilisers
Authors: Tansupo Panadda , Suwannasom Pirom , Luthria Devanand L. , Chanthai Saksit , Ruangviriyachai Chalerm 
Published: October 2009

AbstractIntroduction – The overuse of petrochemical‐based synthetic fertilisers has caused detrimental effects to soil, water supplies, foods and animal health. This, in addition to increased awareness of organic farming, has generated considerable interest in the evaluation of renewable biofertilisers.Objective – The three objectives of the current research were: (1) to evaluate and optimise a solid phase extraction procedure for extraction of three plant hormones, IAA, GA3 and ABA from two model biofertilisers produced from coconut shells and pineapple peels; (2) to develop an HPLC analysis procedure for the simultaneous separation and quantification of three plant hormones (IAA, GA3 and ABA); and (3) to evaluate the changes in three plant hormones levels at four different fermentation time periods and varying number of general bacteria, lactic acid bacteria and yeast.Result – An optimised procedure for sample preparation, separation and simultaneous analysis of three plant hormones [indole‐3‐acetic acid (IAA), gibberellic acid (GA3) and abscisic acid (ABA)] produced in liquid biofertilisers was developed. This method involves sample cleanup using a Sep‐pack Oasis®MAX cartridge containing mixed‐mode anion‐exchange and reverse‐phase sorbents that provided optimum recovery of 85.6, 91.9 and 94.3%, respectively, for the three hormones, IAA, GA3, and ABA. Baseline separation of three hormones was achieved using mobile phase consisting of 1% acetic acid and acetonitrile (75:25, v/v) at pH 4.0. The amounts of hormones produced in liquid biofertilisers were influenced by fruit types, fermentation time and total number of general bacteria, lactic acid bacteria and yeasts. The quantities of three plant hormones produced during fermentation correlated well with the total number of microorganisms present in the liquid biofertilisers.Conclusion – A simple and rapid sample preparation procedure followed by RP‐HPLC with UV detection was optimised and developed for simultaneous quantification and identification of three plant hormones namely, IAA, GA3 and ABA in the liquid biofertilisers. This procedure allows quantification of the three plant hormones in their natural states without any prior derivatisation step. The results presented illustrate that the contents of the three plant hormones depended on the type of fruit wastes, fermentation time and the number of microorganisms found in liquid biofertilisers. This method can be extended to determine the quantity of three hormones in other matrices. This assay procedure will aid in the development of liquid biofertilisers, a valuable alternative fertilisers to promote plant growth. This process will help farmers to reduce production cost and pollution problems. Copyright © 2009 John Wiley & Sons, Ltd.
Comprehensive two‐dimensional gas chromatography–mass spectrometry analysis of volatile constituents in Thai vetiver root oils obtained by using different extraction methods
Authors: Pripdeevech Patcharee , Wongpornchai Sugunya , Marriott Philip J. 
Published: October 2009

AbstractIntroduction – Vetiver root oil is known as one of the finest fixatives used in perfumery. This highly complex oil contains more than 200 components, which are mainly sesquiterpene hydrocarbons and their oxygenated derivatives. Since conventional GC‐MS has limitation in terms of separation efficiency, the comprehensive two‐dimensional GC‐MS (GC × GC‐MS) was proposed in this study as an alternative technique for the analysis of vetiver oil constituents.Objective – To evaluate efficiency of the hyphenated GC × GC‐MS technique in terms of separation power and sensitivity prior to identification and quantitation of the volatile constituents in a variety of vetiver root oil samples.Methodology – Dried roots of Vetiveria zizanioides were subjected to extraction using various conditions of four different methods; simultaneous steam distillation, supercritical fluid, microwave‐assisted, and Soxhlet extraction. Volatile components in all vetiver root oil samples were separated and identified by GC‐MS and GC × GC‐MS. The relative contents of volatile constituents in each vetiver oil sample were calculated using the peak volume normalization method.Results – Different techniques of extraction had diverse effects on yield, physical and chemical properties of the vetiver root oils obtained. Overall, 64 volatile constituents were identified by GC‐MS. Among the 245 well‐resolved individual components obtained by GC × GC‐MS, the additional identification of 43 more volatiles was achieved.Conclusion – In comparison with GC‐MS, GC × GC‐MS showed greater ability to differentiate the quality of essential oils obtained from diverse extraction conditions in terms of their volatile compositions and contents. Copyright © 2009 John Wiley & Sons, Ltd.
Limited prescription privileges for psychologists: Review and implications for the practice of psychology in the schools
Authors: Ball Carrie R. , Kratochwill Thomas R. , Johnston Hugh F. , Fruehling J. Jay 
Published: October 2009

AbstractIn this article, we present a balanced view of the prescriptive authority debate in relation to five major issues and within the context of the practice of psychology in the schools: (a) appropriate training, (b) quality of care, (c) access to services, (d) continuity of care, and (e) professional identity. We also provide an analysis of the quality and relevance of each issue within the school practice context. Despite the increasing momentum of the prescriptive authority initiative at the state level, it seems unlikely that prescription privileges will be extended to psychologists working in school‐based practice settings. Nevertheless, informed school psychologists have the opportunity to become involved in this issue at both the national and state levels. These efforts may take the form of supporting or opposing the initiative or of lobbying for extension of prescriptive authority into some school settings. At the individual level, informed school psychologists will have the opportunity to develop strong working relationships with prescribing psychologists in their communities and to exercise appropriate professional judgments when referring students or families for services in the community. © 2009 Wiley Periodicals, Inc.
Current medications for the treatment of Attention‐Deficit/Hyperactivity Disorder
Authors: Vaughan Brigette S. , Roberts Holly J. , Needelman Howard 
Published: October 2009

AbstractAttention‐Deficit/Hyperactivity Disorder (ADHD) is common among children. Fortunately, ADHD is highly treatable with medication. The purpose of this article is to serve as a primer on medication treatment for ADHD for school psychologists. The article discusses the available stimulant and nonstimulant medication for the treatment of ADHD. Additionally, this article discusses educational implications of medication treatment in the schools. Psychosocial interventions will also be highlighted in this article given their efficacy when paired with stimulant medications for children with ADHD. © 2009 Wiley Periodicals, Inc.
Electro‐optical and cathodoluminescence properties of low temperature grown ZnO nanorods/p‐GaN white light emitting diodes
Authors: Kishwar S. , Hasan K. ul , Tzamalis G. , Nur O. , Willander M. , Kwack H. S. , Dang D. Le Si 
Published: October 2009

AbstractVertically aligned ZnO nanorods (NRs) with a diameter in the range of 160–200 nm were grown on p‐GaN/sapphire substrates by aqueous chemical growth technique and white light emitting diodes (LEDs) are fabricated. The properties of this LED were investigated by parameter analyzer, cathodoluminescnce (CL), electroluminescence (EL), and photoluminescence (PL). The I–V characteristics of the fabricated ZnO/GaN heterojunction revealed rectifying behavior and the LED emits visible EL when bias is applied. From the CL it was confirmed that both the ZnO NRs and the p‐GaN are contributing to the observed peaks. The observed EL measurements showed two emission bands centered at 450 nm and a second broad deep level defect related emission centered at 630 nm and extending from 500 nm and up to over 700 nm. Moreover, the room temperature PL spectrum of the ZnO NRs/p‐GaN reveals an extra peak at the green color wavelength centered at 550 nm. Comparison of the PL, CL, and EL data suggest that the blue and near red emissions in the EL spectra are originating from Mg acceptor levels in the p‐GaN and from the deep levels defects present in the ZnO NRs, respectively. The mixture of high and low energy colors, i.e., blue, green, and red, has led to the white observed luminescence.
Dielectric spectroscopy of CuBiP2S6 crystals
Authors: Dziaugys Andrius , Banys Juras , Macutkevic Jan , Samulionis Vytautas , Vysochanskii Yulian 
Published: October 2009

AbstractInvestigation results of broadband dielectric (20 Hz–1 MHz) properties of layered CuBiP2S6 crystals are presented. At higher temperatures the dielectric properties are strongly influenced by high electrical conductivity. The DC conductivity and conductivity relaxation time exhibit an anomaly close to the phase transition temperature Tc=220 K. Activation energies of both parameters are very similar, this suggests that the conductivity mechanism is single Cu ions hopping, and phase transition is of superionic type. Close to the phase transition temperature the dielectric relaxation appears, and its origin is discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐field electron mobility in InGaAs quantum wells
Authors: Požela Juras , Požela Karolis , Shkolnik Alexey , Sužiedėlis Algirdas , Jucienė Vida , Mikhrin Sergey , Mikhrin Vladimir 
Published: October 2009

AbstractA new approach to design the electron–optical phonon scattering rate in a quantum well (QW), based on the dependence of interface phonon frequency upon QW interface composition, is suggested. Possibilities to regulate a scattering rate of electrons by interface phonons in the InGaAs QW by selecting QW barrier materials are considered. It is shown that the electron–interface phonon scattering rate in the In0.2Ga0.8As QW can be changed by several times by choosing content x in the Alx Ga1–x As QW barriers and in the inserted Inx Al1–x As barrier in the QW centre. It is observed experimentally that the low‐field mobility decreases and the high‐field saturated drift velocity increases with the increase of the Iny Ga1–y As/ Inx Al1–x As interface phonon energy. It is shown that the electron drift velocity saturates at the electric field F > 4 kV/cm and achieves values of 1.3–1.5 × 107 cm/s. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Peculiarities of ionic transport in LLTO solid electrolytes
Authors: Šalkus Tomas , Bohnke Odile , Macutkevic Jan , Orliukas Antanas Feliksas , Greičius Simonas , Kezionis Algimantas , Krotkus Arūnas , Suzanovičienė Rasa , Adomavičius Ramūnas 
Published: October 2009

AbstractThe Li3xLa2/3–xTiO3 (LLTO) (x = 0.1 Li+) ionic conductor was investigated by microwave spectrometer set‐up in the 106–109 Hz frequency range and by time‐domain transmission terahertz spectrometer in the 2·1011–3·1012 Hz frequency range. A relaxation dispersion of $ \tilde \sigma $ and $ \tilde \epsilon $ of LLTO ceramics was found in the microwave region and was attributed to the Li+ relaxation in bulk. The resonance dispersion of $ \tilde \sigma $ and $ \tilde \epsilon $ was found in the terahertz region with resonance frequency ω0. The value of ω0 correlates well with the value of attempt frequency f0, found from the Arrhenius plot of the relaxation frequency fR. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electroreflectance diagnostics of InGaN/AlGaN/GaN based LEDs structures
Authors: Avakyants Lev , Bokov Pavel , Chervyakov Anatoly , Chuas Alexey , Yunovich Alexander , Vasileva Elena , Yavich Boris 
Published: October 2009

AbstractThe LEDs InGaN/AlGaN/GaN heterostructures have been studied by means of electroreflectance spectroscopy. The interference fringes were observed in the electroreflectance spectra in the range of 460 – 1000 nm. Analysis of the period of the fringes shows that they are connected with the interference in the layers of the heterostructure with thicknesses of 240 nm, 720 nm and 4.9 μm. The interference signal from the region between multiple quantum wells and reflective mirror is connected with the changing of the reflection coefficient from the multiple quantum wells due to modulation of the electric field in the pn‐junction and was used to determine the position of the multiple quantum wells in the heterostructures. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric properties of MWCNT based polymer composites close and below percolation threshold
Authors: Macutkevic Jan , Seliuta Dalius , Valusis Gintaras , Banys Juras , Kuzhir Polina , Maksimenko Sergey , Kuznetsov Vladimir , Moseenkov Sergey , Usolseva Anna , Mazov Ilya , Ischenko Arcady , Lambin Philippe 
Published: October 2009

AbstractResults of broadband (20 Hz‐1 MHz) dielectric spectroscopy of multi‐wall carbon nanotubes/polymethylmethacrylate composites with low loading of the carbon fillers (up to 0.5 wt%) are reported. The temperature behaviour of complex dielectric permittivity of MWCNT/PMMA composites with 0.25 wt% is similar to the pure PMMA polymer. However, the dielectric permittivity and electric conductivity of composites with 0.5 wt% are very high and both parameters are almost temperature independent. The high complex dielectric permittivity of these composites indicates the onset of percolation threshold. The relaxation time of β relaxation is shorter in MWCNT/PMMA composites than in pure PMMA. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Terahertz imaging using high electron mobility transistors as plasma wave detectors
Authors: Nadar S. , Coquillat D. , Sakowicz M. , Videlier H. , Teppe F. , Dyakonova N. , Knap W. , Peiris J.‐M. , Lyonnet J. , Seliuta D. , Kasalynas I. , Valušis G. , Madjour K. , Théron D. , Gaquière C. , Poisson M.‐A. 
Published: October 2009

AbstractTwo experiments demonstrate that high electron mobility transistors (HEMTs) are well suited for terahertz (THz) imaging. We have shown that HEMTs can be effectively used as plasma wave detectors in a THz imaging system at frequencies higher than 1 THz at room temperature and this device are sensitive to the polarization direction of THz radiation. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dielectric investigation of lead‐free perovskite strontium titanate with 25% bismuth ceramics
Authors: Grigalaitis Robertas , Banys Juras , Bagdzevicius Sarunas , Sternberg Andris , Bormanis Karlis 
Published: October 2009

AbstractIn this work lead‐free 0.75SrTiO3‐0.25BiTiO3 ceramics have been investigated in broad frequency range. Obtained results showed pronounced dispersion below room temperature typical for the dipolar glasses. The calculated relaxation time distribution function broadens toward longest relaxation times part on cooling. The obtained most probable relaxation time diverges according to the Vogel‐Fulcher relationship with the following parameters: dipole activation energy EA=2123 K, glassy state temperature T0=52.7 K, shortest relaxation time, referring to dipole relaxations at very high temperatures, τ0=2.1·10–14 s. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sol‐gel synthesis and XPS study of vanadium‐hydroquinone oxide bronze films
Authors: Bondarenka V. , Tvardauskas H. , Grebinskij S. , Senulis M. , Pašiškevičius A. , Volkov V. , Zakharova G. 
Published: October 2009

AbstractA vanadium – hydroquinone oxide bronze has been synthesized by using a sol gel technology. The V2O5 powder, hydrogen peroxide, and hydroquinone C6H4(OH)2 were used as the starting materials to produce the bronze. At first the vanadium gel was made by the dissolving of vanadium pentoxide powder in hydrogen peroxide at 273 K. Then the solution was heated up to 350 K for the dissociation of peroxide complexes. An aqueous solution of hydroquinone was mixed with the formed gel in molar ratio 0.33:1. In this way the V2O5±δ·nH2O/HQ (HQ‐hydroquinone) gel was synthesized. These gels are applied on the Ni pad and dried in an air (wet gel synthesis) or heated up to 580 K in air for 1 h for the water removal from gel (bronze production). The wet gel, as well as a bronze, was investigated by means of XPS method. Analysis of V‐O region of XPS spectra shows that vanadium in both cases (wet gel and bronze) is in stable V5+ state. Oxygen in wet gel can be associated with V ions, hydroxide group and water. In bronze oxygen is connected with V and hydrogen (hydroxide). (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence of ZnO crystals under surface and bulk excitation regimes
Authors: Serevičius Tomas , Miasojedovas Saulius , Gavryushin Vladimir , Juršėnas Saulius 
Published: October 2009

AbstractLuminescence properties of vapor phase grown ZnO single crystals with different content of deep traps were explored under one‐photon and two‐photon excitation. Room‐temperature near bandgap emission of highly excited ZnO crystals was originated by inelastic exciton scattering. Under surface excitation regime, luminescence decay profile was governed by exciton diffusion and bimolecular recombination. At higher excitation, exciton recombination transients were significantly altered by stimulated emission. Two‐photon bulk‐like excitation revealed exciton recombination dynamics related to defect states. Correlation between the luminescence decay rate and the density of deep trap states of variously annealed crystals was observed. Results on crystal optical quality were in line with estimated values of stimulated emission threshold. The largest value of the average luminescence decay time τlu = 1.5 ns and the lowest value of the stimulated emission threshold Iexc = 0.6 mJ/cm2 were obtained for ZnO crystal annealed in vacuum. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An easterly tip jet off Cape Farewell, Greenland. I: Aircraft observations
Authors: Renfrew I. A. , Outten S. D. , Moore G. W. K. 
Published: October 2009

AbstractAn easterly tip jet event off Cape Farewell, Greenland, is described and analysed in considerable detail. In Part I of this study (this paper) comprehensive aircraft‐based observations are described, while in Part II of this study numerical simulations and a dynamical analysis are presented. The easterly tip jet of 21 February 2007 took place during the Greenland Flow Distortion experiment. It resulted through the interaction of a barotropic synoptic‐scale low pressure system in the central North Atlantic and the high topography of southern Greenland.In situobservations reveal a jet core at the coast with peak winds of almost 50 m s−1, about 600–800 m above the sea surface, and of 30 m s−1at 10 m. The depth of the jet increased with wind speed from ∼1500 m to ∼2500 m as the peak winds increased from 30 to 50 m s−1. The jet accelerated and curved anticyclonically as it reached Cape Farewell and the end of the barrier. The easterly tip jet was associated with a tongue of cold and dry air along the coast of southeast Greenland, general cloud cover to the east, and cloud streets to the south of Cape Farewell. Precipitation was observed during the low‐level components of the flight. The very high wind speeds generated a highly turbulent atmospheric boundary layer and resulted in some of the highest surface wind stresses ever observed over the ocean. Copyright © 2009 Royal Meteorological Society
Bond‐dissociation using hybrid DFT
Authors: Siegbahn Per E. M. , Blomberg Margareta R. A. 
Published: October 2009

AbstractThe calculation of potential curves and potential surfaces is the main approach for quantum chemical studies of reaction mechanisms. For a sufficient accuracy, qualitatively correct descriptions of bond cleavages and bond formations are required. When large models are used, such as for systems of biological interest, in practice the only available method is DFT. The most common variant is hybrid DFT with the B3LYP functional. In the present study, two cases of bond dissociation using B3LYP are discussed, one for the single O–O bond in hydrogen peroxide, the other one for the hextuple bond in the chromium dimer. Quite accurate results are obtained in both cases. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
The second largest component in the supercritical 2D Hamming graph
Authors: van der Hofstad Remco , Luczak Malwina J. , Spencer Joel 
Published: October 2009

AbstractThe two‐dimensional Hamming graph H(2,n) consists of the n2 vertices (i,j), 1 ≤ i,j ≤ n, two vertices being adjacent when they share a common coordinate. We examine random subgraphs of H(2,n) in percolation with edge probability p, in such a way that the average degree satisfies 2(n − 1)p = 1 + ε. Previous work [8] has shown that in the barely supercritical region n−2/3 ln1/3n ≪ ε ≪ 1, the largest component satisfies a law of large numbers with mean 2εn. Here we show that the second largest component has, with high probability, size bounded by 28ε−2 log(n2ε3), so that the dominant component has emerged. This result also suggests that a discrete duality principle holds, where, after removing the largest connected component in the supercritical regime, the remaining random subgraphs behave as in the subcritical regime. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010
The effect of induced subgraphs on quasi‐randomness
Authors: Shapira Asaf , Yuster Raphael 
Published: October 2009

AbstractOne of the main questions that arise when studying random and quasi‐random structures is which properties
$ \cal P$
are such that any object that satisfies $ \cal P$
“behaves” like a truly random one. In the context of graphs, Chung, Graham, and Wilson (Combinatorica 9 (1989), 345–362) call a graph p‐quasi‐random if it satisfies a long list of the properties that hold in G(n,p) with high probability, such as edge distribution, spectral gap, cut size, and so on.Our main result here is that the following holds for any fixed graph H: if the distribution of induced copies of H in a graph G is close (in a well defined way) to the distribution we would expect to have in G(n,p), then G is either p‐quasi‐random or p̄‐quasi‐random, where p̄ is the unique nontrivial solution of the polynomial equation xδ(1 − x)1−δ = pδ(1 − p)1−δ, with δ being the edge density of H. We thus infer that having the correct distribution of induced copies of any single graph H is enough to guarantee that a graph has the properties of a random one. The proof techniques we develop here, which combine probabilistic, algebraic, and combinatorial tools, may be of independent interest to the study of quasi‐random structures. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2010