bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure dependence of photoluminescence spectra of self‐assembled InAs/GaAs quantum dots
Authors: Manjón F.J. , Goñi A.R. , Syassen K. , Heinrichsdorff F. , Thomsen C.
Published: February 2003

Photoluminescence (PL) measurements have been performed in InAs/GaAs self‐assembled quantum dots (QDs) under high excitation conditions at low temperatures and under high hydrostatic pressures up to 10 GPa. Mechanically polished samples for high pressure experiments exhibited PL emission from the QD ground state but not from the excited states. Instead, a new broad band is observed in the energy range of the first excited state, which is tentatively attributed to emission from smaller dots formed during the mechanical thinning of the sample. With increasing pressure we found a similar blue shift for the PL maxima of the QD ground state (65 meV/GPa) and of the new broad band (69 meV/GPa). These pressure coefficients are 20% and 40% lower than those reported for dots of less than half the height as in our case and for the wetting layer, respectively. Our results point to a systematic reduction of the pressure coefficient of the InAs QDs with the increase of the dot height.
Raman scattering under pressure and the phase transition in ε‐GaSe
Authors: Kulibekov A. M. , Olijnyk H. P. , Jephcoat A. P. , Salaeva Z. Y. , Onari S. , Allakhverdiev K. R.
Published: February 2003

Raman scattering in ε‐GaSe has been investigated at room temperature in a diamond anvil cell by using helium gas as a pressure transmitting medium. The first observation of the solid–solid phase transition under pressure from a hexagonal structure at ambient pressure to a NaCl‐type at around 29.2 GPa is reported. A photoinduced change in the pressurised crystal was observed. The transition under pressure was found to be irreversible at room temperature. It was shown that the pressurised form of ε‐GaSe at ambient conditions most probably belongs to the γ‐type as characterised by an increased intensity of the Raman modes at 234 cm–1 and 250 cm–1.
Pressure induced phase transitions of BNs
Authors: Shirai K. , Fujita H. , Katayama‐Yoshida H.
Published: February 2003

Phase stability and phase transitions of boron nitride polymorphoic modifications have been re‐examined by using a first‐principles pseudopotential method based on the local‐density approximation. In order to study systematically, the graphite–diamond transition is also examined. The present result again confirms that the dense form is more stable than the layered form. However, this might not be conclusive, because the accuracy of the used exchange‐correlation functionals has yet been established.
Electrical resistivity of Cu doped As–Se glasses at high pressure
Authors: Ramesh K. , Ramesh Rao N. , Sangunni K. S. , Gopal E. S. R.
Published: February 2003

Electrical resistivity measurements have been performed on CuxAs40Se60–x glasses with x between 0 and 28 at% of Cu. The resistivity of these glasses continuously decreases and saturates at higher quasi‐hydrostatic pressures. The pressure derivative of the electrical resistivity shows distinct changes as a function of composition; a large change for the initial addition of Cu (≤ 10 at% Cu) and levelling off for higher content of Cu. To understand this, Differential Scanning Calorimetric (DSC) and thermal crystallization studies have been carried out on all these glasses. Thermal crystallization of As–Se glasses with 5 and 10 at% Cu results in crystalline Cu3AsSe4 and As2Se3 phases, whereas glasses with 15 and 20 at% of Cu crystallize into Cu3AsSe4 phase only. Glasses with 25 and 28 at% of Cu yield a new binary Cu2As3 and the ternary Cu3AsSe4 phase. These structural differences arising as a function of composition are reflected in the pressure derivative of the resistivity of the glasses.
High‐pressure studies of the recombination processes, threshold currents, and lasing wavelengths in InAs/GaInAs quantum dot lasers
Authors: Marko I.P. , Andreev A.D. , Adams A.R. , Krebs R. , Reithmaier J.P. , Forchel A.
Published: February 2003

The threshold current of broad area GRINSCH InAs quantum dot (QD) lasers has been measured as a function of hydrostatic pressure in the range of 0–12 kbar. The laser emission photon energy, Elaser, increases linearly with pressure, p, at 10.1 meV/kbar and 8.3 meV/kbar for 980 nm and 1.3 μm QD lasers, respectively. For the 980 nm QD lasers the threshold current increases with pressure at a rate proportional to the square of the photon energy, E2laser. However, the threshold current of the 1.3 μm QD laser decreases by 26% over a 12 kbar pressure range, demonstrating the importance of the Auger recombination in 1.3 μm QD lasers. The results are discussed in the framework of a theoretical model based on the electronic structure and radiative recombination calculations carried out using an 8 × 8 k · p Hamiltonian.
Proceedings of the Tenth International Conference on High Pressure Semiconductor Physics (HPSP‐X)
Authors: Murdin Ben
Published: February 2003

The Tenth International Conference on High Pressure Semiconductor Physics (HPSP‐X) was held as a satellite meeting of the International Conference on the Physics of Semiconductors in Guildford from 5 to 8 August 2002. It brought together scientists and engineers who use high pressure to study the science and technology of semiconductors. The HPSP‐X conference reviewed the latest issues and developments in the physics of both bulk and low‐dimensional semiconductor materials and devices under pressure. It covered all aspects of fundamental and applied high‐pressure semiconductor research, including experimental and theoretical investigations under isotropic or anisotropic stress conditions. Topics such as electronic structures, vibrational and optical properties, transport phenomena, defect states, phase transitions, and novel materials or structures are included in this issue.

Following the meetings HPSP‐VII in Schwäbisch Gmünd, phys. stat. sol. (b) 198, No. 1 (1996); HPSP‐VIII in Thessaloniki, phys. stat. sol. (b) 211, No. 1 (1998), and HPSP‐IX in Sapporo, phys. stat. sol. (b) 223, No. 1/2 (2001), the proceedings of this successful conference series are published in physica status solidi for the fourth time.
Theoretical Prediction of the Phenoxyl Radical Formation Capacity and Cyclooxygenase Inhibition Relationships by Phenolic Compounds
Authors: Ruiz Juan , Pouplana Ramon
Published: February 2003

Due to the importance of the O‐H bond dissociation in the antioxidant mechanism of anti‐inflammatory phenols, we studied the biradical process Ph‐OH→PhO.+H. for 25 phenolic compounds using ab initio calculations. Enthalpies of reaction (ΔHr), changes in the electron density at the O‐H bond critical point (ρOH) and total atomic charges of ortho and para carbon atoms strongly correlate with the in vitro inhibition of cyclooxygenase activity by phenols. The most active compounds have large values of the electron density at the O‐H bond (ρOH), thus favouring the O‐H bond dissociation. In contrast, inactive compounds have small values of the electron density at the O‐H bond (ρOH), thus reducing the hydrogen donation ability. These results are also supported by the representation of the molecular electrostatic potentials maps. The prediction of the cyclooxygenase inhibitory activity of the proposed QSAR equations is analysed using the multilineal (MLR) method. Finally, the differences in biological activity are examined by analysing the binding interactions of active compounds in the pocket site of human COX‐2 enzyme structure derived from crystallographic X ‐ray data.
Mechanistic Study on N‐Demethylation Catalyzed with P450 by Quantitative Structure Activity Relationship using Electronic Properties of 4‐Substituted N,N‐Dimethylaniline
Authors: Nanbo Asuka , Nanbo Toshio
Published: February 2003

The mechanism of N‐demethylation by P‐450 was investigated using MO calculation of 4‐substituted N,N‐dimethylaniline. The reactivities of the compounds and their intermediates were examined using the energies of HOMO and SOMO, and frontier electron densities. QSAR analysis using these electronic parameters indicated that one‐electron first transfers from nitrogen to P‐450 and the resultant cation radical forms α‐amino radical, followed by hydroxylation and N‐demethylation.
Reliability of estimation of recombination energies of molecular radical cations by charge exchange and a test of the exoergicity rule
Authors: Youn Yeu Young , Choe Joong Chul , Kim Myung Soo
Published: February 2003

Charge exchange occurring in a collision cell of a mass spectrometer was used previously to find the very long‐lived excited electronic states of molecular cations generated by electron ionization. The underlying criterion in the method, called the exoergicity rule, was that only electronically exoergic and resonant processes have large cross sections at low collision energy. The validity of this rule has been checked in this work by estimating the recombination energies of some molecular ions based on the presence/absence of charge‐exchange signals from gases with different ionization energies, and comparing these estimates with the literature values. It is concluded that a recombination energy can be estimated to within an upper limit uncertainty of 0.1 eV with this technique, which validates the exoergicity rule proposed previously. Copyright © 2003 John Wiley & Sons, Ltd.
In vivo biotransformation of 17α‐methyltestosterone in the horse revisited: identification of 17‐hydroxymethyl metabolites in equine urine by capillary gas chromatography/mass spectrometry
Authors: Dumasia M. C.
Published: February 2003

The in vivo phase I biotransformation of 17α‐methyltestosterone in the horse leads to the formation of a complex mixture of regio‐ and stereoisomeric C20O2, C20O3 and C20O4 metabolites, excreted in urine as glucuronide and sulphate phase II conjugates. The major pathways of in vivo metabolism are the reduction of the A‐ring (di‐ and tetrahydro), epimerisation at C‐17 and oxidations mainly at C‐6 and C‐16. Some phase I metabolites have been identified previously by positive ion electron ionisation capillary gas chromatography/mass spectrometry (GC/EI + MS) mainly from the characteristic fragmentation patterns of their methyloxime‐trimethylsilyl ether (MO‐TMS), enol‐TMS or TMS ether derivatives. Following oral administration of 17α‐methyltestosterone to two castrated thoroughbred male horses, the glucuronic acid conjugates excreted in post‐administration urine samples were selectively hydrolysed by E. coli β‐glucuronidase enzymes. Unconjugated metabolites and the steroid aglycones obtained after enzymatic deconjugation were isolated from urine by solid‐phase extraction, derivatised as MO‐TMS ethers and analysed by GC/EI + MS. In addition to some of the known metabolites previously identified from the characteristic mass spectral fragmentation patterns of 17α‐methyl steroids, some isobaric compounds exhibiting a diagnostic loss of 103 mass units from the molecular ions with subsequent losses of trimethylsilanol or methoxy groups and an absence of the classical D‐ring fragment ion were detected. From an interpretation of their mass spectra, these compounds were identified as 17‐hydroxymethyl metabolites, formed in vivo in the horse by oxidation of the 17‐methyl moiety of 17α‐methyltestosterone. This study reports on the GC/EI + MS identification of these novel 17‐hydroxymethyl C20O3 and C20O4 metabolites of 17α‐methyltestosterone excreted in thoroughbred horse urine. Copyright © 2003 John Wiley & Sons, Ltd.
Lacidipine, a potential peroxynitrite scavenger: investigation of activity by liquid chromatography and mass spectrometry
Authors: Garzotti Marco
Published: February 2003

Inflamed tissues are often characterised by the production of .NO and O2− radicals, which are known to react at an extremely fast rate to produce peroxynitrite (ONOO−). This highly oxidising entity reacts with protein‐bound tyrosine to give 3‐nitrotyrosine, which is considered a biochemical marker of peroxynitrite‐induced damage. Lacidipine is a calcium antagonist indicated for the treatment of mild to moderate hypertension. In the present work, electrospray mass spectrometry with and without liquid chromatography was used to evaluate the capability of lacidipine and two other related molecules as ONOO− scavengers. This capability is compared with that associated with a number of commercial polyphenols described in the literature as efficient scavengers of this cytotoxic agent. The use of mass spectrometry provided rapid quantitative assessment of both the nitration and its reduction, and showed that lacidipine possesses a reasonable capability for reducing in vitro nitration of superoxide dismutase. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of silsesquioxanes by size‐exclusion chromatography and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Falkenhagen Jana , Jancke Harald , Krüger Ralph‐Peter , Rikowski Eckhard , Schulz Günter
Published: February 2003

Liquid chromatography in combination with spectroscopic methods like matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS) or nuclear magnetic resonance (NMR) spectroscopy is a powerful method to characterize silsesquioxanes and silsesquioxane mixtures. As new examples, the formation of silsesquioxyl‐substituted silsesquioxanes [(n‐octyl)7(SiO1.5)8]2O and [(n‐octyl)7(SiO1.5)8O]2[(n‐octyl)6(SiO1.5)8] as well as the cage rearrangement of octa‐[(n‐heptyl)silsesquioxane] to larger structur es [(n‐heptyl)SiO1.5)]n up to n=28 are shown. Copyright © 2003 John Wiley & Sons, Ltd.
McLafferty‐type rearrangement in the collision‐induced dissociation of Li+, Na+ and Ag+ cationized esters of N‐acetylated peptides
Authors: Anbalagan V. , Patel J. N. , Niyakorn G. , Van Stipdonk M. J.
Published: February 2003

In this study we investigated the multi‐stage collision‐induced dissociation (CID) of N‐terminally acetylated di‐, tri‐ and tetrapeptides in the form of C‐terminal ethyl, n‐propyl, isopropyl, n‐butyl and tert‐butyl esters and cationized by the attachment of Li+, Na+ and Ag+. While methyl ester versions of the metal cationized peptides primarily eliminate H2O following collisional activation and dissociation, the ethyl, propyl and butyl ester versions of the peptides exhibit a dissociation pathway consistent with γ‐hydrogen transfer to the C‐terminal carbonyl group, with associated elimination of an alkene, in a McLafferty‐type rearrangement. The rearrangement leaves a metal cationized, free‐acid form of the peptide, as confirmed by comparing the multi‐stage CID of rearrangement products generated from peptide esters with the CID of corresponding metal cationized free‐acid peptides. The transfer of a γ‐hydrogen in the rearrangement reaction was confirmed by investigating the CID of ethyl esters for which the terminal methyl group was labeled with deuterium. We found that the rearrangement product was significantly more abundant, relative to other product ions, when derived from isopropyl and tert‐butyl esters than from ethyl, n‐propyl or n‐butyl ester analogues. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of Tripamide in human urine by high‐performance liquid chromatography and high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry
Authors: Kim Yunje , Hwang Joungboon , Kim Myungsoo , Lee Won
Published: February 2003

Tripamide is a drug widely used in clinical practice for the treatment of hypertension and edema. This work evaluated a screening method for Tripamide and its urinary metabolites in human urine, using high‐performance liquid chromatography diode‐array detection (HPLC/DAD). Identification of these metabolites was investigated by high‐performance liquid chromatography/electrospray ionization tandem mass spectrometry (HPLC/ESI‐MS/MS) after dosing with 15 mg Tripamide. Acid hydrolysis showed that Tripamide is conjugated in the body. Two suspected metabolites were detected by HPLC/DAD. HPLC/ESI‐MS/MS analysis suggested that these metabolites were probably hydroxylated together with loss of the ‐NH2 group and dehydrogenation. These results will be useful in confirmation methods for Tripamide in doping control. Copyright © 2003 John Wiley & Sons, Ltd.
Exploring the ester‐exchange reactions of diester‐diterpenoid alkaloids in the aconite decoction process by electrospray ionization tandem mass spectrometry
Authors: Wang Yong , Shi Lei , Song Fengrui , Liu Zhiqiang , Liu Shuying
Published: February 2003

The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work electrospray ionization tandem mass spectrometry was used to explore the ester‐exchange reactions for aconitine‐type diester‐diterpenoid alkaloids occurring during the process of decocting aconite root. The aconitines were screened in a diverse range of samples, including crude aconite, decoction of crude aconite, residues from decoction of crude aconite, prepared aconite, decoction of prepared aconite, decoction of prepared aconite with added palmitic acid, and decoction of a mixture of mesaconitine and hypaconitine standards with liquorice root. It was found that diester‐diterpenoid aconitines were converted into lipo‐alkaloids as well as monoester alkaloids by the decoction of aconite. Copyright © 2003 John Wiley & Sons, Ltd.
Quantitative assay of plasma homocysteine thiolactone by gas chromatography/mass spectrometry
Authors: Daneshvar Parham , Yazdanpanah Mehrdad , Cuthbert Carla , Cole David E. C.
Published: February 2003

Enzymatic cyclization of homocysteine forms a reactive thiolactone that may play an important role in its cardiovascular toxicity, but reliable quantitation of the free thiolactone metabolite in physiological fluids has not been reported. We have therefore used a highly selective gas chromatography/mass spectrometry (GC/MS) technique combined with the sensitivity of negative chemical ionization (NCI) to develop a quantitative method for the detection of homocysteine thiolactone (HcyTL) in plasma. To improve accutacy the deuterated isomer d4‐HcyTL was synthesized and added to plasma as internal standard. The plasma was then treated with silica solid‐phase extraction and derivatized with heptafluorobutyric anhydride. The derivative was analyzed by GC/MS in NCI mode with methane as the reagent gas and quantified by analyzing for the HcyTL ion [M− HF] and its d4‐HcyTL counterpart in single‐ion monitoring mode. The calibration curve showed a dynamic linear range up to 40 nmol/L. Within‐day precision (n = 20, nominal concentration 5.2 nmol/L) was 0.96% and between‐day precision was 3.9%, with a detection limit of 1.7 nmol/L and quantification limit of 5.2 nmol/L. Two human plasma samples had HcyTL concentrations of 18 and 25 nmol/L. This facile method for quantitation of homocysteine thiolactone opens the way for more detailed clinical studies of its potential role in homocysteine‐induced arteriosclerosis and vaso‐occlusive disease. Copyright © 2003 John Wiley & Sons, Ltd.
Liquid chromatography/tandem mass spectrometric determination of inhibition of human cytochrome P450 isozymes by resveratrol and resveratrol‐3‐sulfate
Authors: Yu Chongwoo , Shin Young Geun , Kosmeder Jerome W. , Pezzuto John M. , van Breemen Richard B.
Published: February 2003

trans‐Resveratrol, a phenolic phytoalexin occurring in grapes, wine, peanuts, and cranberries, has been reported to both have anticarcinogenic, antioxidative, phytoestrogenic, and cardioprotective activities, and to be a weak inhibitor of cytochrome P450 (CYP)3A4, which might have significance for drug–drug interactions. Since trans‐resveratrol is rapidly converted in vivo to primarily trans‐resveratrol‐3‐sulfate, a rapid, selective, and sensitive method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed to investigate human cytochrome P450 inhibition by trans‐resveratrol‐3‐sulfate. Effects of trans‐resveratrol and trans‐resveratrol‐3‐sulfate on the metabolism of selective cytochrome P450 substrates (CYP1A2/ethoxyresorufin, CYP2C9/diclofenac, CYP2C19/(S)‐mephenytoin, CYP2D6/bufuralol, CYP3A4/testosterone) were monitored using cDNA‐expressed human recombinant isozymes. For method validation, LC/MS/MS was used to measure the inhibition of various cytochrome P450 isozymes by different concentrations (0–50 μM) of known selective inhibitors. IC50 values of 3.2, 1.4, 8.9, 0.2, and 0.3 μM were obtained for the standard isozyme inhibitors CYP1A2/furafylline, CYP2C9/sulfaphenazole, CYP2C19/tranylcypromine, CYP2D6/quinidine, and CYP3A4/ketoconazole, respectively, which were in good agreement with literature values. trans‐Resveratrol showed IC50 values of 11.6 μM for CYP2C19 and 1.1 μM for CYP3A4, but the IC50 values exceeded 50 μM for all the other CYP isozymes, which indicated no inhibition. No enzyme inhibition was observed for trans‐resveratrol‐3‐sulfate. Our results indicate that trans‐resveratrol is a marginal inhibitor of CYP3A4 and a weak inhibitor of CYP2C19, but its major metabolite trans‐resveratrol‐3‐sulfate is not an inhibitor of any of the cytochrome P450 isozymes investigated. Copyright © 2003 John Wiley & Sons, Ltd.
Stereochemical analysis of 3,4‐methylenedioxymethamphetamine and its main metabolites by gas chromatography/mass spectrometry
Authors: Pizarro Nieves , Llebaria Amadeu , Cano Silvia , Joglar Jesús , Farré Magí , Segura Jordi , Torre Rafael de la
Published: February 2003

3,4‐Methylenedioxymethamphetamine (MDMA, ecstasy) is consumed as the racemate but some metabolic steps are enantioselective. In addition, chiral properties are preserved during MDMA biotransformation. A quantitative analytical methodology using gas chromatography/mass spectrometry (GC/MS) to determine enantioselective disposition in the body of MDMA and its main metabolites including 3,4‐methylenedioxyamphetamine (MDA), 4‐hydroxy‐3‐methoxymethamphetamine (HMMA), and 4‐hydroxy‐3‐methoxyamphetamine (HMA) was developed. Plasma and urine samples were collected from a male volunteer. The analysis of MDMA, MDA, and 4‐hydroxy‐3‐methoxy metabolites by GC/MS required a two‐step derivatization procedure. The first step consisted of derivatization of the amine with enantiomerically pure Mosher's reagent ((R)‐MTPCl). Triethylamine was used as a base to neutralize hydrochloric acid formed during the reaction allowing quantitative derivatization, which resulted in a substantial improvement in the sensitivity of the method compared with other previously described techniques. Further treatment with ammonium hydroxide was required since both amine and hydroxyl groups underwent derivatization in the reaction. Ammonium hydroxide breaks bonds formed with hydroxyl groups without affecting amine derivatives. The second derivatization step using hexamethyldisilazane was needed for metabolites containing phenol residues. This derivatization method permitted the stereochemically specific study of MDMA and its main monohydroxylated metabolites by GC/MS. A detailed study of the chemical reactions involved in the derivatization steps was indispensable to develop a straightforward, sensitive, and reproducible method for the analysis of the parent drug compound and its metabolites. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of micromachined hollow tips for two‐dimensional nanoelectrospray mass spectrometry
Authors: Sjödahl Johan , Melin Jessica , Griss Patrick , Emmer Åsa , Stemme Göran , Roeraade Johan
Published: February 2003

In this work an improved design of chip‐based nanoelectrospray nozzles is reported. Two‐dimensional matrices of out‐of‐plane 10 μm i.d. silicon dioxide tips with a tapered shape were manufactured using deep reactive ion etching technology. Using a peptide sample, six micromachined tips and six commercially pulled silica capillary tips were compared employing an ion trap mass spectrometer. At a flow rate of 100 nL/min, the detectability obtained was approximately the same for the two types of tips. The relative standard deviation of the signal‐to‐noise ratio for the peptides between six different tips was on average 22% for the micromachined tips and 45% for the pulled capillary tips. The usefulness of the micromachined tips for analysis of non‐covalent protein‐ligand complexes was demonstrated by the analysis of a sample of RNase A and cytidine 2′‐monophosphate. In another test, analyzing a tryptic digest of 1 pmol/μL cytochrome C, 18 peptides corresponding to a 82% sequence coverage were detected. Using MS/MS, the whole sequence of an 11 amino acid cytochrome C fragment was obtained. Computer simulations were performed on the shape and magnitude of the electrical field around micromachined and pulled capillary tips. To reach the threshold electric field density at the tip apex required to initiate an electrospray, a higher electrospray voltage was needed for the chip‐based tips compared with pulled capillary tips. This is due to the influence of the chip base. Copyright © 2003 John Wiley & Sons, Ltd.
Identification of Software Process Knowledge Management
Authors: Meehan Bridget , Richardson Ita
Published: February 2003

The effective and explicit management of knowledge has been presented as a key factor in the survival of companies in current business environments. The software development business is no different. The authors of this paper investigated two software processes in three small software development companies to identify the explicit and tacit knowledge management in these processes. They examine their findings under the four knowledge management categories of creation, storing, sharing and leverage. In many cases, while the knowledge exists, it is not made explicit within the organization. Making the knowledge explicit should make the software processes more effective. Therefore, the authors make recommendations for the small software development company as to how to do this. Whether this approach can ultimately help the small software development company to move to higher levels of maturity is a research question which needs to be further explored. Copyright © 2003 John Wiley & Sons, Ltd.
The Holon Framework and Software Process Improvement: A Radiotherapy Project Case Study
Authors: Bell G. A. , Cooper M. A. , Qureshi S.
Published: February 2003

This paper discusses the Holon Framework, which aims to control and improve the software development process. It is an interdisciplinary approach that is derived from software engineering and the systems movement. We outline key characteristics of software process control and improvement. Criticisms of the orthodox algorithmic cost models are identified to justify the use of alternative mathematical techniques such as system dynamics. We argue that mathematical techniques used in planning can be linked with hard systems thinking. Therefore, the essence of hard systems thinking is highlighted, and a serious weakness identified, to explain the development of soft methodologies and soft systems thinking. A significant limitation of soft systems methodology is highlighted to substantiate the need to combine it with the goal/question/metrics methodology. We justify the case study approach given the nature of the investigation. An overview of the Holon Framework is provided. The soft part of the framework, which is linked to improvement, is employed to identify relevant problems and generates a baseline metrics programme. The research design of the case study is used to evaluate our findings. Finally, we outline future work in employing the hard part of the framework, which is linked to control; this will complete the full cycle of the approach. Copyright © 2003 John Wiley & Sons, Ltd.
Learning from Failures
Authors: Dalcher Darren , Tully Colin
Published: February 2003

This paper addresses the topic of failures in computer‐based systems. It does so in three stages: first it describes failure cases in a single domain, that of computer‐based ambulance despatch systems; then it discusses some of the features of those cases; finally it considers the importance of reporting and analysing failures, in order to discover their causes and to learn lessons that will help eliminate those causes of failure in the future. Failure, it is argued, provides a valuable learning opportunity that may lead, when recognized, to better practice and future success. Copyright © 2003 John Wiley & Sons, Ltd.
Formation of Amylose‐Lipid Complexes and Effects of Temperature Treatment. Part 1. Monoglycerides
Authors: Tufvesson Fredrik , Wahlgren Marie , Eliasson Ann‐Charlotte
Published: February 2003

The formation of amylose‐lipid complexes of form I (amorphous structure) and form II (crystalline structure) during heating was studied by differential scanning calorimetry (DSC) for a range of monoglycerides and for monoglyceride mixtures. The temperature treatment applied to amylose‐monoglyceride‐mixtures were either the first scan in DSC (10 °C/min, 15‐144 °C) or a prolonged heat treatment where the samples were kept at 100 °C for 24 h before being analysed in DSC. The temperature treatment influenced which type of complex was formed, and how much, whereas the thermal stability (as judged from the transition peak temperature) was only marginally influenced. It is shown in this study that all the investigated monoglycerides were able to give complex form I as well as complex form II, although the conditions for the formation differed between the monoglycerides. It was found that a simple DSC‐scan was enough for formation of complex form II for the shortest monoglycerides (glycerol monocaprin, glycerol monolaurin and glycerol monomyristin), whereas in case of the longer monoglycerides and monoglyceride mixtures the prolonged heat treatment was required for formation of complex form II. Moreover, the monoglyceride mixtures gave only form II at conditions where the individual components in the mixtures gave both form I and form II.
Influence of Pine Nut (Pinus koraiensis) Oil Fractions on Physicochemical Properties of Rice Starch Solutions
Authors: Lee Seog‐Won , Rhee Chul
Published: February 2003

The physicochemical properties of rice starch suspensions effected by interactions with pine nut oil fractions were investigated. Oil fractions (crude pine nut oil, glycolipid, nonpolar lipid, gums, and degummed oil) from pine nut (Pinus koraiensis) were prepared by solvent extraction and addition of boiling water. The influence of the fractions on the physicochemical properties of rice amylose solution (5%, w/w) was determined by measuring the complexing index, absorbance ratio (630/520 nm), colour, rheological characteristics, and microscopic structure at various concentrations. Their effect on rice starch swelling power was also determined. The glycolipid fraction had the highest complexing index with rice amylose. Rice amylose solutions containing the glycolipid fraction exhibited greater pseudoplastic fluid (n<0.7) behaviour, higher colour difference values, and lower absorption ratios (1.64‐1.48) than did those containing other fractions. Hydrated oil fraction (gums) complexed with amylose only poorly, if at all, but amylose solutions containing them had rheological properties similar to those containing the glycolipid fraction. The addition of oil fractions increased the swelling power value compared to the control.
In vitro Starch Digestibility and Nutritionally Important Starch Fractions in Cereals and Their Mixtures
Authors: Aarathi Amruthmahal , Urooj Asna , Puttaraj Shashikala
Published: February 2003

Dietary carbohydrates are characterized with respect to both chemical composition and likely site, rate and extent of digestion. Starch is divided into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS). The present investigation aimed at evaluating the effect of starch source on nutritionally important starch fractions and the extent of in vitro starch digestion in four processed cereals, namely rice, ragi (Eleusine coracona), wheat, jowar (Sorghum vulgare) and their mixtures in varying proportions, using controlled enzymatic hydrolysis with pancreatin and amyloglucosidase. Rapidly available glucose (RAG) was also measured to derive a starch digestion index (SDI). The total starch and amylose content in the raw cereals ranged from 21 — 26.6 and 12.6 — 20.7 g/100 g, respectively. Among the four basic cereals, roti (flat, unleavened pancake, diameter 12 cm) produced from ragi had highest total starch, RDS and SDI. However, in mixtures containing two or more cereals RDS and SDI were lower than those observed in single cereals. Significant correlations were observed between RAG and SDI, or RDS, respectively (r=0.91, r=0.96, p<0.01). An inverse relation between amylose content and SDI (r= ‐0.78, p<0.01) indicates the influence of amylose on the extent of starch digestion. The results highlight the importance of starch source in determining the starch fractions of processed cereals and their mixtures. The simple in vitro measurement of starch fractions could serve as a tool for characterizing dietary carbohydrates with respect to their digestion in the gut.
EuCN2 — The First, but Not Quite Unexpected Ternary Rare Earth Metal Cyanamide
Authors: Reckeweg Olaf , DiSalvo Francis J.
Published: February 2003

Red‐orange, transparent single crystals of EuCN2 (Pnma (62), a = 1232.41(9), b = 395.26(3) and c = 539.43(4) pm, Z = 4) are obtained by the reaction of EuN, C and NaN3 in arc‐welded Ta ampoules at 1300 K. The first ternary rare earth metal cyanamide is isotypic to α‐SrCN2 and shows the characteristic frequencies for the CN22— unit in the optical spectra (νs = 1244; νas = 1969 and 2087; δ = 655 / 666 cm—1).
Synthesis and Structures of Potassium Bisdithiocarbamate Salts
Authors: Cook David A. , Coles Simon J. , Hursthouse Michael B. , Price Daniel J.
Published: February 2003

Two structurally related dipotassium bisdithiocarbamate salts: K2[(S2CNRCH2)2](EtOH)2; R = Me, i‐Pr, were synthesised from the corresponding diamines. X‐ray structure determinations were performed on single crystals grown from ethanolic solutions. The different alkyl substituents have a profound affect upon the solid‐state structures, with the methyl derivative possessing a complex a 3‐D network and the isopropyl derivative a 2‐D lamellar structure.
Correlation between Solution and the Solid State: The pH Dependent Composition in the Ternary System [Co(H2O)6]2+ or [Ni(H2O)6]2+/Piperazine/Phosphate
Authors: Craven Emma , Abu‐Shandi Khalid , Janiak Christoph
Published: February 2003

The protolytic equilibria of piperazine (C4H10N2) and phosphate have been investigated in the presence of cobalt or nickel chloride or nitrate by potentiometric titrations between pH 2 and 8. Potentiometric titrations suggest the presence of [M2+(H2O)5(C4H11N2+)]3+ and [M2+(H2O)5(C4H10N2)]2+ in solution with stability constants logK of 3.1 and 3.8 for M = Co and 3.1 and 3.6 for M = Ni, respectively. Crystallization experiments were then conducted at selected pH values to isolate desired species from the known solution composition. Crystallization afforded [M(H2O)6]2+(C4H12N22+)(HPO42—)2 at pH 3.5 and 6.2 (M = Co, Ni), and Co3(PO4)2·8H2O at pH 10.5. No crystals with the dihydrogenphosphate anion or a metal‐bound piperazine ligand could be isolated under the reaction conditions. The solid‐state assembly in the isomorphous structures of [M(H2O)6](C4H12N2)(HPO4)2 with M = Co and Ni is based on an extended hydrogen bonded network between the three ionic building blocks.
Spectral and Structural Studies of the Copper(II) Complexes of 3, 4‐Hexanedione Bis(3‐azacyclothiosemicarbazones)
Authors: Jasinski Jerry P. , Bianchani Jason R. , Cueva Juan , El‐Saied Fathy A. , El‐Asmy Ahmed A. , West Douglas X.
Published: February 2003

Copper(II) complexes of 3, 4‐hexanedione bis(piperidyl‐ and bis(hexamethyleneiminylthiosemicarbazone), H2Hxpip and H2Hxhexim, respectively, have been prepared and studied spectroscopically. The bis(thiosemicarbazones) have been characterized by their melting points, as well as IR, electronic and 1H NMR spectra. Upon formation of their copper(II) complexes, loss of the hydrazinic hydrogen atoms occurs, and the ligands coordinate as dianionic, tetradentate N2S2 ligands. The crystal structures of H2Hxpip, its 4‐coordinate copper(II) complex, [Cu(Hxpip)], and the related [Cu(Hxhexim)] have been determined by single crystal x‐ray diffraction. The nature of the four‐coordinate copper(II) complexes have also been characterized by ESR, IR, and electronic spectroscopy, as well as magnetic moments and elemental analyses.
Synthesis and Structural Characterization of Zinc Complexes with Sulfonamides containing 8‐Aminoquinoleine
Authors: Macías Benigno , García Isabel , Villa María V. , Borrás Joaquín , Castiñeiras Alfonso , Sanz Francisca
Published: February 2003

Sulfonamides obtained by reaction of 8‐aminoquinoline with benzenesulfonyl, toluene‐4‐sulfonyl and naphthalene‐2‐sulfonyl chlorides have been used to synthetize coordination compounds with ZnII with a ZnL2 composition. Determination of the crystal structures for the resulting complexes by X‐ray diffraction shows a distorted tetrahedral environment for the Zn2+ ions, sulfonamides acting as bidentate ligands through the nitrogen atoms from the sulfonamidate and quinoline groups. FT‐IR, 1H and 13C NMR and mass spectra of these compounds are also discussed.
Metal Complexes with a New Tetrapyridyl Pendant Armed Macrocyclic Ligand. X‐ray Crystal Structures of CuII and NiII Complexes
Authors: Valencia Laura , Bastida Rufina , López‐Deber Montserrat , Macías Alejandro , Rodríguez Adolfo , Vicente Manuel
Published: February 2003

A new pendant‐armed macrocyclic ligand, L1, bearing four pyridyl pendant groups has been synthesized by N‐alkylation of the tetraazamacrocyclic precursor L with 2‐picolyl chloride hydrochloride. Metal complexes of L1 have been synthesized and characterized by microanalysis, MS‐FAB, conductivity measurements, IR, UV‐Vis, 1H and 13C NMR spectroscopy and magnetic studies. Crystal structures of the ligand L1 as well as of the complexes [Ni2L1](ClO4)4·5CH3CN and [Cu2L1](ClO4)4·4.5CH3CN have been determined by single crystal X‐ray crystallography. The X ray studies show the presence of two metal atoms within the macrocyclic ligand in both metal complexes showing five coordination arrangement for the metal ions.
Different Coordinative (N, N) and (N, O) Bidentate Behaviour of N‐2‐Pyridyl‐Sulfonamides. Electrochemical Synthesis and Characterization of Cadmium(II) Complexes
Authors: Beloso Inmaculada , Castro Jesús , García—Vázquez José A. , Pérez—Lourido Paulo , Romero Jaime , Sousa Antonio
Published: February 2003

Electrochemical oxidation of cadmium in an acetonitrile solution of N‐2‐pyridyl‐sulfonamides (HL) afforded cadmium coordination compounds of composition [CdL2]. Heteroleptic complexes of composition [CdL2L′] (L′ = 2, 2′‐bipyridine or 1, 10‐phenanthroline) were obtained when the coligand L′ was added to the electrolytic phase. The crystal structures of several compounds have been determined by X‐ray diffraction. In all cases the cadmium atom is hexacoordinated, but the coordinative behaviour of the N‐2‐pyridyl‐sulfonamide ligand depends on the location of the substituents in the pyridyl ring. When the substituent is in position 3, the ligands act as N, O‐donors. In all other cases, the ligands act as N, N′‐bidentate systems.
Synthesis, Structure and Reactivity of [1, 2‐Bis(diphenylphosphinite)ethane]bromotricarbonylmanganese(I) with Reactions of Phosphites, Phosphonites. and Phosphinites
Authors: Bravo Jorge , Castro Jesús , García‐Fontán Soledad , Lamas Elvira M. , Rodríguez‐Seoane Pilar
Published: February 2003

The manganese carbonyl complex [MnBr(CO)3L] (1), where L = Ph2POCH2CH2OPPh2, was prepared by reacting [MnBr(CO)5] with the bidentate ligand 1, 2‐Bis(diphenylphosphinite)ethane. From this compound and the appropriate phosphite, phosphinite or phosphonite ligands were synthesized the complexes [MnBr(CO)2LL′], where L′ = P(OMe)3 (2) or P(OEt)3 (3) and [MnBr(CO)3L′2], where L′ =PPh(OEt)2 (4) or PPh2(OEt) (5).

The obtained compounds have been characterized by elemental analysis, mass spectrometry, IR and NMR (1H, 13C and 31P) spectroscopies and X‐ray diffractometry for the complexes 1, 4 and 5.
Die Kristallstrukturen der Monohydrate von Lithiumchlorid und Lithiumbromid
Authors: Hönnerscheid Andreas , Nuss Jürgen , Mühle Claus , Jansen Martin
Published: February 2003

Mit Hilfe von Einkristall‐ und Pulverdaten wurden die Kristallstrukturen der Monohydrate von Lithiumchlorid und Lithiumbromid aufgeklärt. Die Verbindungen kristallisieren isotyp in der Raumgruppe Cmcm (LiCl·H2O: Einkristallstrukturanalyse; T = 100 K; a = 758, 35(2); b = 768, 07(2); c = 762, 35(2) pm; Z = 8; 1179 unabhängige Reflexe; R1 = 0, 0196. LiBr·H2O: Rietveld‐Verfeinerung; T = 220 K; a = 806, 15(1); b = 799, 44(1); c = 794, 61(1) pm; Z = 8; 157 unabhängige Reflexe; Rp = 0, 0922; Rwp = 0, 0979;Rexp = 0, 0657). Die Struktur lässt sich gemäß X(H2O)Li□2 (X = Cl, Br) von der Perowskitstruktur ableiten. Dabei sind weder die Wassermoleküle noch die Li‐Kationen fehlgeordnet. Die Orientierung der Wassermoleküle ist eindeutig an die Verteilung der Li‐Kationen gekoppelt und umgekehrt. Die hohe Li‐Ionenleitfähigkeit in der kubischen Hochtemperaturphase von LiBr·H2O wird erklärt mit der einsetzenden Rotationsbewegung der Wassermoleküle beim Phasenübergang, die einen Platzwechsel der Li‐Kationen bzw. das Aufschmelzen der Li‐Teilstruktur begünstigen.
Die Kristallstrukturen der Hydroxyhalogenide Li4(OH)3Br und Li4(OH)3I
Authors: Hönnerscheid Andreas , Nuss Jürgen , Mühle Claus , Jansen Martin
Published: February 2003

Mit Hilfe von Einkristall‐ und Röntgenpulverdaten wurden die Kristallstrukturen der Hydroxyhalogenide Li4(OH)3Br und Li4(OH)3I aufgeklärt. Li4(OH)3Br kristallisiert in der Raumgruppe P21/m und ist isotyp zum leichteren Homologen Li4(OH)3Cl (Rietveld‐Verfeinerung; T = 293 K; a = 545, 41(1); b = 758, 13(1); c = 650, 20(1) pm; β = 93, 82(1)°; Z = 2; 300 unabhängige Reflexe; Rp = 0, 106; Rwp = 0, 109; Rexp = 0, 081).

Li4(OH)3I kristallisiert in der Raumgruppe Pmmn in einer Variante der LiOH Struktur, in der 1/4 der Hydroxid‐ durch Iodid‐Anionen ausgetauscht sind (Einkristallstrukturanalyse; T = 100 K; a = 1029, 5(4); b = 525, 9(2); c = 573, 2(2) pm; Z = 2; 392 unabhängige Reflexe; R1 = 0, 0642).
Single Crystal X‐ray Structure Investigation and Electronic Structure Studies of La‐Deficient Nickel Stannide La4.87Ni12Sn24 Grown from Sn Flux
Authors: Zhuravleva Marina A. , Bilc Daniel , Mahanti S. D. , Kanatzidis Mercouri G.
Published: February 2003

The cubic La4.87Ni12Sn24 was synthesized in reactions involving liquid Sn. The compound crystallizes in the cubic syngony, space group Im3¯, Z = 2, cell parameter a = 11.9662(14) Å, and is related to the Gd3Ni8Sn16 structure type previously refined from powder X‐ray data. The crystal structure of La4.87Ni12Sn24 was solved and refined using single crystal X‐ray data to final R1 = 2.67%, wR2 = 6.92%. The refinement showed no mixed occupancy with Sn for the La(1) site, contrary to what was proposed for Gd3Ni8Sn16. Instead, a partial occupancy of 87% was detected for the La(1) at 2a. Electronic structure calculations show that the system is metallic, and the density of states at the Fermi level falls at a peak with the highest contribution coming from La(1) atoms, if the compound with ideal occupancies La5Ni12Sn24 is assumed. The deficiency of the La(1) site could therefore originate in the lowering of the total energy of the system due to the loss of 0.39 electrons per formula unit. Magnetic measurement data indicates nearly temperature independent Pauli paramagnetism. Theoretical estimation of the magnetic susceptibility after including core diamagnetic corrections agrees well with experiment.
Syntheses, Crystal Structures, and Thermal Behavior of Co(phen)(HL)2 and [Co2(phen)2(H2O)4L2]·H2O with H2L = Pimelic Acid
Authors: Zheng Yue‐Qing , Lin Jian‐Li , Kong Zu‐Ping
Published: February 2003

Two CoII complexes, Co(phen)(HL)2 (1) and [Co2(phen)2(H2O)4L2]·H2O (2) (H2L = HOOC‐(CH2)5‐COOH), were synthesized and structurally characterized on the basis of single crystal X‐ray diffraction data. In complex 1 the Co atoms are tetrahedrally coordinated by two N atoms of one phen ligand and two O atoms of different hydrogenpimelato ligands. Through π—π stacking interactions between carboxyl group and phen ligand, the complex molecules are assembled into 1D columnar chains, which are connected by intermolecular hydrogen bonds. Complex 2 consists of the centrosymmetric dinuclear [Co2(phen)2(H2O)4L2] molecules and hydrogen bonded H2O molecules. The Co atoms are each octahedrally surrounded by two N atoms of one phen ligand and four O atoms from two bis‐monodentate pimelato ligands and two H2O molecules at the trans positions. The results about thermal analyses, which were performed in flowing N2 atmosphere, on both complexes were discussed. Crystal data: (1) C2/c (no. 15), a = 13.491(1)Å, b = 9.828(1)Å, c = 19.392(2)Å, β = 100.648(1)°, U = 2526.9(4)Å3, Z = 4; (2) P1 (no. 2), a = 11.558(1)Å, b = 11.947(3)Å, c = 15.211(1)Å, α = 86.17(1)°, β = 75.55(1)°, γ = 69.95(1)°, U = 1910.3(3)Å3, Z = 2.
Library portals: toward the semantic Web
Authors: Sadeh Tamar , Walker Jenny
Published: February 2003

The semantic Web is an exciting prospect, but not yet a reality, for researchers who are faced with an ever‐increasing range of material – some freely available and some accessible to them only by virtue of their affiliation. This paper introduces the concept of the semantic Web and indicates how, if realized, the semantic Web could be of great benefit to researchers. Some parallel activities now under way are aimed at providing practical solutions to scholars today through the use of agent technology built into library portals; the paper explains, in particular, how one system, MetaLib – the library portal solution from Ex Libris – addresses these issues.
The case for e‐books: an introduction
Authors: Long Sarah Ann
Published: February 2003

This article explores some of the applications of the e‐book in the modern library. With over 30 years of history, recent computing advances have finally made electronic book technology a viable option to both publishers and libraries. The advantages libraries gain from the medium are many, but companies such as NetLibrary and ebrary have shown that the industry still needs to establish a definitive means of making their products successfully usable in the library environment. Library networks and consortia, such as the Golden Gateway Library Network and the Marion County (Indiana) Internet Library, have found practical ways to share e‐book subscriptions with their members; by obtaining subscriptions for the consortium, the individual members can all make use of the same collection. E‐books continue to be a matter of discussion in library discussions, and the benefits and disadvantages are being weighed in libraries across the country.
From individual to team learning: practical perspectives on the learning organisation
Authors: Yeo Roland
Published: February 2003

This paper distils practical perspectives from experienced consultants on an integrative framework on organisational learning and performance. The foundation of this framework is governed by behavioural and cognitive learning theories. Convergent interviewing was the methodology used to verify the practicality of the framework and provide insight for further development. Data derived from four organisational development consultants confirmed the framework’s feasibility, but suggested additional issues to examine organisational learning further. The conclusion drawn is that there are distinct stages of learning but the relationship between them is robust and dynamic. Further, the notion of “triple‐loop learning” is often misconstrued in practical contexts due to its level of abstraction. Effective leadership is regarded as the leitmotif in driving strategic organisational learning initiatives. However, leaders must consider the time factor involved, as such initiatives can only take effect after a period of time rather than immediately.