bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive online quality control for injection‐molding by monitoring and controlling mold separation
Authors: Chen Zhongbao , Turng Lih‐Sheng , Wang Kuo‐King
Published: March 2006

This paper presents a unique method that makes use of a small signal (of the magnitude of microns) measured by a precision linear displacement transducer mounted on the outside of mold plates to monitor the momentary separation of the core and cavity plates. The maximum value of the separation is found to be highly correlated with part weight, one of the important quality indices. The whole profile of the mold separation (MS) is monitored and used in order to control the process adaptively and to keep the part quality consistent. Adaptive algorithms are developed to control the switchover point from filling to packing in terms of hydraulic pressure from shot to shot. Within a shot, the hydraulic pressure during the holding stage is manipulated to control the MS profile. The experimental results with different resins and mold geometries show that the variation of part weight is reduced significantly as compared to the conventional hydraulic pressure control. POLYM. ENG. SCI. 46:569–580, 2006. © 2006 Society of Plastics Engineers
Effect of multi‐walled carbon nanotubes dispersity on the light transmittancy of multi‐walled carbon nanotubes/epoxy composites
Authors: Wang Jianguo , Fang Zhengping , Gu Aijuan
Published: March 2006

Two types of multi‐walled carbon nanotubes (MWCNTs), chemically modified and unmodified, were dispersed in epoxy resin with ultrasonication. The light transmittance characteristics of epoxy composites with different ratios of MWCNTs to epoxy resin were measured at wavelengths ranging from 200 to 1100 nm. Results showed that composites with modified MWCNTs had a much higher light transmittance than those with unmodified MWCNTs. This was presumably due to a more uniform dispersion of modified MWCNTs in the epoxy matrix, as indicated by both transmission electron microscopy and optic microscopy. The wavelength dependency of light transmittance of the composites was expressed empirically as a function of weight fraction (fw) of MWCNTs and the light wavelength (λ). POLYM. ENG. SCI. 46:635–642, 2006. © 2006 Society of Plastics Engineers.
Solubilities of sub‐ and supercritical carbon dioxide in polyester resins
Authors: Nalawade Sameer P. , Picchioni Francesco , Janssen Leon P.B.M. , Patil Vishal E. , Keurentjes Jos. T.F. , Staudt Reiner
Published: March 2006

In supercritical carbon dioxide (CO2) assisted polymer processes the solubility of CO2 in a polymer plays a vital role. The higher the amount of CO2 dissolved in a polymer the higher is the viscosity reduction of the polymer. Solubilities of CO2 in polyester resins based on propoxylated bisphenol (PPB) and ethoxylated bisphenol (PEB) have been measured using a magnetic suspension balance at temperatures ranging from 333 to 420 K and pressures up to 30 MPa. An optical cell has been used to independently determine the swelling of the polymers, which has been incorporated in the buoyancy correction. In both polyester resins, the solubility of CO2 increases with increasing pressure and decreasing temperature as a result of variations in CO2 density. The experimental solubility has been correlated to the Sanchez–Lacombe equation of state. POLYM. ENG. SCI. 46:643–649, 2006. © 2006 Society of Plastics Engineers
Strain and strain‐rate formulation for flow‐induced crystallization
Authors: Dai Shao‐Cong , Qi Fuzhong , Tanner Roger I.
Published: March 2006

It has been suggested that isothermal flow‐induced crystallization is jointly linked to strain and strain rate. Here we test this idea further by studying some results of Bove and Nobile on isotactic poly (1‐butene). We also present some new experimental results on polypropylene in finite amplitude sinusoidal oscillation. The ranges of strain amplitude and frequency are from 0.1% to 10% and from 0.1 to 30 Hz, respectively. The experimental data are compared with the results calculated by using a multimode PTT model with a suspension‐based theory; both strain and strain rate are involved in the flow‐induced crystallization. A fairly good agreement between experiments and calculations has been observed. We conclude that a simple strain plus strain‐rate function gives a reasonable description of flow‐induced crystallization at low shear rates. POLYM. ENG. SCI. 46:659–669, 2006. © 2006 Society of Plastics Engineers
Effect of mixing protocol on compatibilized polymer blend morphology
Authors: Lin Bin , Sundararaj Uttandaraman , Guegan Philippe
Published: March 2006

We investigated the effect of mixing protocol on the morphology of compatibilized polymer blends made with premade compatibilizer and reactively formed in‐situ compatibilizer in a custom‐built miniature mixer Alberta Polymer Asymmetric Minimixer (APAM). The compatibilized blends show a finer morphology than uncompatibilized blends if the polymers are mixed together in the dry state and then fed into the mixer. It is found that premelting one polymer, and premixing polymers and compatibilizer, both greatly affect the compatibilized blends' morphology. The effects are complex since the dispersed phase particle size and distribution of the compatibilized blends may be smaller or larger when compared with the uncompatibilized system, depending on the material's physical and chemical properties; for example, diblock molecular weight or the preference of copolymer to migrate to a particular phase can change the final morphology. Good mobility of the copolymer to reach the interface is crucial to obtain a finer morphology. Micelles are observed when a high molecular weight diblock copolymer P(S‐b‐MMA) is used for a PS/PMMA blend. Because of its enhanced mobility, no micelles are found for a low molecular weight diblock copolymer P(S‐b‐MMA) in a PS/PMMA blend. For PS/PE/P(S‐b‐E) blends, finer morphology is obtained when P(S‐b‐E) is first precompounded with PS. Because the block copolymer prefers the PE phase, if the P(S‐b‐E) block copolymer is compounded with PE first, some remains inside the PE phase and does not compatibilize the interface. In the case of reactive blend PSOX/PEMA, premelting and holding the polymers at high temperature for 5 min decreases final dispersed phase particle size; however, premelting and holding for 10 min coarsens the morphology. POLYM. ENG. SCI. 46:691–702, 2006. © 2006 Society of Plastics Engineers.
Preparation and properties of waterborne polyurethaneurea consisting of fluorinated siloxane units
Authors: Su Teng , Wang Gui You , Xu Xu Dong , Hu Chun Pu
Published: March 2006

A series of polyurethaneurea (PUU) aqueous dispersions were prepared via a prepolymer process from polyester polyol, α,ω‐dihydroxypoly[(3,3,3‐trifluoropropyl) methylsiloxane] (PTFPMS), dimethylolpropionic acid, isophorone diisocyanate, and ethylenediamine. These anionic‐type aqueous dispersions were stable at the ambient temperature for more than 6 months, with particle sizes ranging from 69 to 127 nm. For these aqueous dispersions, the surface tension decreased with increasing PTFPMS content, but the particle size increased with a maximum value. The film prepared from the PUU aqueous dispersion consisting of 5 wt % PTFPMS (APU‐FS‐5) exhibited excellent waterproof performance. Furthermore, the tensile strength of the APU‐FS‐5 film increased nearly 3 times compared with that of the PUU film without PTFPMS, whereas the elongation at break only decreased a little; this indicated that the water‐resistant and mechanical properties could be enhanced markedly and simultaneously for the PUU films containing both silicon and fluorine groups. The experimental results showed a high degree of hydrogen bonding for urea groups and an increased microphase‐separation degree between the hard and soft segments in the PTFPMS‐modified system, which resulted in the excellent mechanical properties of these films. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3365–3373, 2006
Olefin polymerization catalyzed by amide vanadium(IV) complexes: The stereo‐ and regiochemistry of propylene insertion
Authors: Cuomo Cinzia , Milione Stefano , Grassi Alfonso
Published: March 2006

The reaction of VCl3(THF)3 with 1 equiv of the lithium salt of ligand ArNH(Me2SiCH2CH2SiMe2)NHAr or ArNH(SiMe3) (Ar = 2,6‐Me2C6H3) afforded the corresponding V(IV) amide complexes, [1,2‐CH2CH2(Me2SiNAr)2]VCl2 (3) and (Me3SiNAr)2VCl2 (4). The activation of 3 and 4 with the alkyl aluminum compound Al2Et3Cl3 or AlEt2Cl produced active ethylene polymerization catalysts exhibiting productivity values among the highest reported for vanadium amide based catalysts. Moreover, syndiotactic specific propylene polymerization was successfully conducted at −40 °C in the presence of 3/Al2Et3Cl3 and 4/Al2Et3Cl3. Syndiotactic polypropylenes with moderate stereoregularity ([rr] = 0.66) and a concentration of regioirregular propylene of 6.9 mol % were obtained. Monomodal molecular weight distributions and polydispersity indices lower than 2 were observed in the polymerization runs carried out in heptane solutions. Thus, ethylene–propylene copolymers with propylene concentrations up to 45 mol % were synthesized and characterized by 13C NMR and thermal analysis. Good alternation and random distribution of the two monomers were actually obtained. Samples with elevated concentrations of propylene were completely amorphous, with a glass‐transition temperature of −50 °C. The properties and structure of the copolymers produced with amide vanadium catalysts 3 and 4 were similar to those reported for ethylene–propylenes produced with industrial vanadium‐based catalysts, suggesting the presence of the same active catalyst species. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3279–3289, 2006
Synthesis and characterization of core–shell‐type polymeric micelles from diblock copolymers via reversible addition–fragmentation chain transfer
Authors: Zhang Ping , Liu Qunfeng , Qing Aixiang , Shi Jianbo , Lu Mangeng
Published: March 2006

A method was developed to enable the formation of nanoparticles by reversible addition–fragmentation chain transfer polymerization. The thermoresponsive behavior of polymeric micelles was modified by means of micellar inner cores and an outer shell. Polymeric micelles comprising AB block copolymers of poly(N‐isopropylacrylamide) (PIPAAm) and poly(2‐hydroxyethylacrylate) (PHEA) or polystyrene (PSt) were prepared. PIPAAm‐b‐PHEA and PIPAAm‐b‐PSt block copolymers formed a core–shell micellar structure after the dialysis of the block copolymer solutions in organic solvents against water at 20 °C. Upon heating above the lower critical solution temperature (LCST), PIPAAm‐b‐PHEA micelles exhibited an abrupt increase in polarity and an abrupt decrease in rigidity sensed by pyrene. In contrast, PIPAAm‐b‐PSt micelles maintained constant values with lower polarity and higher rigidity than those of PIPAAm‐b‐PHEA micelles over the temperature range of 20–40 °C. Structural deformations produced by the change in the outer polymer shell with temperature cycles through the LCST were proposed for the PHEA core, which possessed a lower glass‐transition temperature (ca. 20 °C) than the LCST of the PIPAAm outer shell (ca. 32.5 °C), whereas the PSt core with a much higher glass‐transition temperature (ca. 100 °C) retained its structure. The nature of the hydrophobic segments composing the micelle inner core offered an important control point for thermoresponsive drug release and the drug activity of the thermoresponsive polymeric micelles. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3312–3320, 2006
Synthesis of amphiphilic star block copolymers via diethyldithiocarbamate‐mediated living radical polymerization
Authors: Ishizu Koji , Katsuhara Hideya , Itoya Kazuo
Published: March 2006

(AB)f star block copolymers were synthesized by the radical polymerization of a poly(t‐butyl acrylate)‐block‐poly(methyl methacrylate) diblock macroinitiator with ethylene glycol dimethacrylate in methanol under UV irradiation. Diblock macroinitiators were prepared by diethyldithiocarbamate‐mediated sequential living radical copolymerization initiated by (4‐cyano‐4‐diethyldithiocarbamyl)pentanoic acid under UV irradiation. The arm number (f) was controlled by the variation of the initial concentration of the diblock initiator. It was found from light scattering data that such star block copolymers (f ≥ 344) not only took a spherical shape but also formed a single molecule in solution. Subsequently, we derived amphiphilic [arm: poly(acrylic acid)‐block‐poly(methyl methacrylate)] star block copolymers by the hydrolysis of poly(t‐butyl acrylate) blocks. These amphiphilic star block copolymers were soluble in water because the external blocks were composed of hydrophilic poly(acrylic acid) chains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3321–3327, 2006
Synthesis of metal (Fe or Pd)/alloy (Fe–Pd)‐nanoparticles‐embedded multiwall carbon nanotube/sulfonated polyaniline composites by γ irradiation
Authors: Reddy Kakarla Raghava , Lee Kwang‐Pill , Gopalan Anantha Iyengar , Kim Min Seok , Showkat Ali Md , Nho Young Chang
Published: March 2006

Composites of multiwall carbon nanotubes (MWCNTs) and sulfonated polyaniline (SPAN) were prepared through the oxidative polymerization of a mixture of aniline, 2,5‐diaminobenzene sulfonic acid, and MWCNTs. Fe, Pd, or Fe–Pd alloy nanoparticles were embedded into the MWCNT–SPAN matrix by the reduction of Fe, Pd, or a mixture of Fe and Pd ions with γ radiation. Sulfonic acid groups and the emeraldine form of backbone units in SPAN served as the source for the reduction of the metal ions in the presence of γ radiation. The existence of metallic/alloy particles in the MWCNT–SPAN matrix was further ascertained through characterization by high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, thermogravimetric analysis, and conductivity measurements. HRTEM pictures clearly revealed the existence of Fe, Pd, and Fe–Pd nanoparticles of various sizes in the MWCNT–SPAN matrices. There were changes in the electronic properties of the MWCNT–SPAN–M composites due to the interaction between the metal nanoparticles and MWCNT–SPAN. Metal‐nanoparticle‐loaded MWCNT–SPAN composites (MWCNT–SPAN–M; M = Fe, Pd, or Fe–Pd alloy) showed better thermal stability than the pristine polymers. The conductivity of the MWCNT–SPAN–M composites was approximately 1.5 S cm−1, which was much higher than that of SPAN (2.46 × 10−4 S cm−1). Metal/alloy‐nanoparticle‐embedded, MWCNT‐based composite materials are expected to find applications in molecular electronics and other fields. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3355–3364, 2006
Quantification of branching in disordered materials
Authors: Kulkarni A. S. , Beaucage G.
Published: March 2006

The phenomenon of structural branching is ubiquitous in a wide array of materials: polymers, ceramic aggregates, polymeric networks, and gels. Branching has a strong influence on the structure–property relationships of these materials. Despite the interdisciplinary importance and decades of effort, the analytical description and quantification of branching are weak. Existing techniques for polymers based on size exclusion chromatography and rheology are, at best, qualitative, and quantitative characterization techniques such as nuclear magnetic resonance spectroscopy and transmission electron microscopy (for ceramic aggregates) have limitations in providing routine quantification. For ceramic aggregates, theoretical work has dominated, and only a few publications on analytical studies exist to support the theory. Small‐angle scattering of X‐rays and neutrons can be used to quantify the branch content through application of concepts native to fractal geometry. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1395–1405, 2006
Pyrotechnic and Thermal Studies on the Magnesium‐Strontium Nitrate Pyrotechnic System
Authors: Tuukkanen Irmeli M. , Charsley Edward L. , Laye Peter G. , Rooney James J. , Griffiths Trevor T. , Lemmetyinen Helge
Published: March 2006

The pyrotechnic and thermal properties of a range of binary magnesium‐strontium nitrate compositions containing from 10% to 90% by mass of magnesium have been determined. The burning rate and light output were measured after consolidating the compositions into cardboard tubes. The exothermicity, temperature of ignition and time to ignition of the compositions were also determined and the products of combustion were characterized.
Redefining ‘doing something’: health professionals' views on their role in the care of stroke patients
Authors: Pound Pandora , Ebrahim Shah
Published: March 2006

Stroke has traditionally been considered, both by lay people and by many people working within the health services, to be a tragic yet essentially uninteresting condition, possibly because of its associations with old age, chronicity and the widespread perception that very little can be done about it. This study explored health professionals' views about their role in caring for people with stroke, and about what they gained from and contributed to this work. Questionnaires were distributed to staff working on an elderly care unit, a general medical ward and a stroke unit. Nurses and physiotherapists were positive and reported that they had much to offer people with stroke, and many rewards to gain from their work. Occupational therapists reported that in theory they had much to contribute to people with stroke, but in practice lack of resources and staff shortages prevented them from fulfilling their potential. Speech therapists also complained of scarce resources, and of a lack of recognition of their specialty, but felt able to contribute to improving peoples' quality of life. Both psychologists reported that their work with people with stroke was satisfying and stimulating. However, with the exception of the consultant on the stroke unit, doctors reported feeling they had little to offer, and little to gain from working with people with stroke. Therapists on the elderly care unit, and speech therapists in all settings reported difficulties within the multidisciplinary team. Although each profession had different concerns and priorities, the majority seemed to have a positive approach to their work with people with stroke. Similarly, the majority reported that the best thing about their work was when people recovered, although professions defined recovery differently. Copyright © 1997 Whurr Publishers Ltd.
The assessment of functional ability in patients with Parkinson's disease: The PLM‐test and three clinical tests
Authors: Kokko Satu‐Mari , Paltamaa Jaana , Ahola Erja , Mälkiä Esko
Published: March 2006

This study assesses functional ability of Parkinson's disease (PD) patients by means of an objective movement analysis (the PLM‐test) and three clinical tests. The correlation between the tests was also studied. The main object of this study was to detect and measure relevant disabilities in Parkinson's disease to obtain a clinical test battery. Copyright © 1997 Whurr Publishers Ltd.
Admission interviews: questions of utility and cost in masters of physical therapy programs in the United States
Authors: Gabard Donald L , Porzio Rochelle , Oxford Toni , Braun Robert
Published: March 2006

Purpose

The purpose of this research was twofold. The first purpose was to assess the predictive validity of the interview process in student completion of entry level Masters of Physical Therapy programs on the conventional schedule for the university. The second was to provide a descriptive study of interview formats currently used by these institutions and the cost to the institution, estimated by hours of labor used exclusively for the interview process.

Method

A questionnaire was mailed to the Director of Admissions of 63 accredited Masters of Physical Therapy programs in the United States. Forty‐three responded to the questionnaire for a response rate of 68.3%. Twenty‐eight programs (65.1%) performed interviews and fifteen (34.9%) programs did not.

Results

A two‐tailed t‐test revealed that no significant difference existed between programs that interview and those that did not with regards to the attrition rate of students. There was great diversity between the programs in interview content and structure. The cost to the institutions in terms of hours averaged 261 hours per school for faculty and support staff combined.

Conclusion

The schools of physical therapy that award the Masters of Physical Therapy degree vary markedly in the interview content and format both between schools and with recommendations known to enhance validity and reliability. Since, no difference exists in attrition of students between schools that interview and those that do not, the expense and time invested by both the institution and the students are important considerations. The findings of this study indicate the need for continued investigation of the effectiveness of the interview process and alternative methods of valid and reliable student selection. Copyright © 1997 Whurr Publishers Ltd.
Respiratory muscle activity and pulmonary function during acutely induced airways obstruction
Authors: van der Schans Cees P , de Jong Wietze , de Vries Gerrie , Postma Dirkje S , Koëter Gerard H , van der Mark Thomas W
Published: March 2006

Background

Patients with airway obstruction may spontaneously breathe with a positive expiratory pressure by pursing their lips during expiration, especially in case of dyspnea. Dyspnea seems to be related to increased activity of the respiratory muscles. A potential explanation for the use of pursed lips breathing (PLB) is that this type of breathing leads to a reduction of respiratory muscle activity. The purpose of this study was to assess the effect of breathing with a positive expiratory pressure of 5cm H2O, simulating pursed lips breathing (SPLB), on respiratory muscle activity and pulmonary function during induced airway obstruction.

Methods

In twelve asthmatic patients, tonic and phasic electromyographic (EMG) activity of the following muscles was obtained: scalene muscle, parasternal muscle, and abdominal muscles. Pulmonary function and EMG measurements were performed before and after propranolol induced airway obstruction.

Results

Simulated pursed lips breathing resulted in a significant increase of functional residual capacity and tidal volume both at baseline and during airway obstruction. Phasic respiratory muscle activity during PEP breathing increased especially at baseline. We conclude that beneficial effects of breathing with a positive expiratory pressure of 5cm H2O, which is similar to pursed lips breathing, cannot be explained by changes in respiratory muscle activity or pulmonary function. Copyright © 1997 Whurr Publishers Ltd.
Deep defect related photoluminescence in heavily doped CuGaTe2 crystals
Authors: Jagomägi Andri , Krustok Jüri , Grossberg Maarja , Danilson Mati , Raudoja Jaan
Published: March 2006

CuGaTe2 samples very often exhibit optical and electrical properties of heavily doped semiconductors. This paper investigates the low temperature photoluminescence properties of polycrystalline CuGaTe2 samples. The photoluminescence spectra of “heavily doped” semiconductors are usually characterized by the broadening of the photoluminescence bands that is caused by the fluctuations of the forbidden band edges. The deep photoluminescence region observed (0.8–1.3 eV) consists of two peaks. One of them is located at 0.955 eV and has been reported before. Another, totally new band was discovered at 1.14 eV. The low‐temperature j‐shift of both bands was detected. Also, rather significant blue shift with the increasing temperature was noticed. It is proposed that both bands consist of two recombination channels. At low temperatures tail‐to‐impurity recombination dominates. As the temperature increases, the tail‐to‐impurity recombination transforms into band‐to‐impurity recombination. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sapphire‐etched vertical‐electrode nitride‐based semiconductor light‐emitting diode (SEVENS LED) fabricated by the wet etching technique
Authors: Kim Seong‐Jin
Published: March 2006

A sapphire‐etched vertical‐electrode nitride‐based semiconductor (SEVENS) light‐emitting diode (LED) has been fabricated by a selective wet etching technique. The light output power of the SEVENS LED is substantially enhanced compared with a conventional NiAu lateral‐electrode (LE) GaN‐based LED formed on a sapphire substrate. The light output power of the SEVENS LED is not saturated up to as high as 300 mA junction current, being a notable improvement over that (250 mA junction current) of the LE LED. The 250 mA light output power of the SEVENS LED with an entire sapphire‐removed surface is 4.3 times larger than that of the LE LED. The variations of peak wavelength and full width at half maximum are less for the SEVENS LED compared to the LE LED. This performance improvement is attributed to the transfer of the sapphire substrate to a silicon substrate and the microroughened surface self‐formed by wet etching of the sapphire substrate. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of III–V nano‐ and microtubes using MOVPE grown materials
Authors: Paetzelt H. , Gottschalch V. , Bauer J. , Herrnberger H. , Wagner G.
Published: March 2006

In this issue's Editor's Choice [1], Paetzelt et al. present a novel class of nano‐ and micro‐dimensional sized objects formed by releasing thin strained multi‐layers from their substrate by selective etching of a sacrificial layer after growth by metal‐organic vapor‐phase epitaxy (MOVPE).

The cover picture is an SEM image of a multi‐layer tube rolled in 〈110〉 direction with a diameter of around 6 µm. This tube was fabricated from the layer system: GaAs buffer/AlAs sacrificial layer/In0.37Ga0.63As strained layer/Al0.35Ga0.65As bottom barrier/GaAs quantum well and Al0.35Ga0.65As top barrier.

The first author, Hendrik Paetzelt, is current a Ph.D. student at the Institute of Inorganic Chemistry of the University of Leipzig. He investigates the growth of highly strained thin films and selective wetchemical etching techniques for the fabrication and the subsequent characterization of nano‐ and microtubes from multi‐layer systems. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of magnetic field on off‐axis donor binding energy in a nanotube
Authors: Orozco E. A. , Gonzalez J. D. , Duarte O. S. , Mikhailov I. D.
Published: March 2006

We analyze the effect of the mixing of the low‐lying s and px ,y subbands on the ground‐state binding energy of the off‐axis donors in cylindrical nanotubes in the presence of a magnetic field parallel to the axis. We express the wave function as a product of combinations of s and p subband wave functions and an envelope function that depends only on the electron–ion separation. By using the variational principle we derive a differential equation for the envelope function, which we solve numerically. The curves for the dependence of the ground‐state binding energies on the donor distance from the axis are presented and it is shown that the effect of the subband mixing for off‐axis donors in nanotubes is considerable. It is found that the magnetic field enhances the binding energies of donors located close to the axis whereas for donors located far from the axis the effect of the magnetic field on the binding energy is the opposite. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Study of the electronic structures of sheelite and sheelite‐like PbWO4
Authors: Yi Zhijun , Liu Tingyu , Zhang Qiren , Sun Yuanyuan
Published: March 2006

The electronic structures of different types of PbWO4 (PWO) crystal have been studied within the framework of the fully relativistic self‐consistent Dirac–Slater theory, using a numerically discrete variational (DV‐Xα) method. In the calculation, the lattice relaxation of sheelite‐like PWO (Pb7.5W8O32) is considered. The densities of states and joint densities of states for sheelite and sheelite‐like PWO clusters are obtained. The calculated results indicate that the electronic structures of sheelite and sheelite‐like PWO clusters embedded in themselves are very similar. However, when the sheelite and sheelite‐like PWO clusters are embedded in each other the electronic structures change significantly; for example, peaks for density of states become undistinguishable, and some states even become forbidden. The calculated results show that stolzite‐type PWO may be the most stable structure and the physical properties of the PWO crystal are sensitive to its structure. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations of the optical and EPR spectra of V3+ ions in C(NH2)3Al(SO4)2 · 6H2O crystal
Authors: Feng Wen‐Lin , Wu Xiao‐Xuan , Zheng Wen‐Chen
Published: March 2006

By means of the diagonalization of the complete energy matrix of 3d2/d8 ions in trigonal symmetry and in consideration of the covalency reduction effect, the optical and EPR spectra of V3+ ions in C(NH2)3Al(SO4)2 · 6H2O crystal are calculated. The results are in agreement with the observed values. The difficulty about the too‐large spin–orbit coupling parameter in the explanation of EPR parameters from the Abragam and Pryce model is removed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic properties of ThSiO4 polymorphs (thorite and huttonite) from first principles calculations
Authors: Shein I. R. , Shein K. I. , Medvedeva N. I. , Ivanovskii A. L.
Published: March 2006

The full‐potential linearized augmented plane wave method with the generalized gradient approximation for the exchange and correlation potential (FLAPW‐GGA) is used to understand the electronic properties of the tetragonal (thorite) and monoclinic (huttonite) polymorphs of thorium orthosilicate ThSiO4. Electronic bands, total and partial density of states and charge density were obtained for the first time and applied to describe the chemical bonding. Both ThSiO4 phases are insulating; the Th 5f states are itinerant and overlap with O 2p bands, the chemical bonding in the both phases is a combination of covalent and ionic types. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Note on the calculation of analytical Hessians in the zeroth‐order regular approximation (ZORA)
Authors: van Lenthe J. H. , van Lingen J. N. J.
Published: March 2006

The previously proposed atomic zeroth‐order regular approximation (ZORA) approach, which was shown to eliminate the gauge dependent effect on gradients and to be remarkably accurate for geometry optimizations, is tested for the calculation of analytical second derivatives. It is shown that the resulting analytic second derivatives are indeed exact within this approximation. The method proves to yield frequencies that are remarkably close to the experimental frequency for uranium hexafluoride but less satisfactory for the gold dimer. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
A conversation with Dr David Reilly
Authors: Reilly David
Published: March 2006

David Reilly, FRCP, MRCGP, FFHom, is a doctor, active in caring for people. He is a Consultant Physician at the Centre for Integrative Care, Glasgow Homoeopathic Hospital; Honorary Senior Lecturer at Glasgow University; Visiting Professor of Medicine in Maryland and faculty member at Harvard Medical School, USA. Trained in orthodox medicine (as a physician and as a GP), complementary medicine (mainly homoeopathy and acupuncture) and mind–body medicine, he has sought fresh ways of approaching medicine and human caring, emphasizing the innate healing capacity in people, the factors that modify this, and their interaction with therapeutic process –especially in the therapeutic encounter. His ideas were recently used as core elements in the Fifth Wave document on future public health development (www.scottishcouncilfoundation.org). A published scientist, a teacher and a broadcaster, he is also a musician and poet and explores the synthesis of art and science (which he nicknamed ‘artience’). He is currently Scotland's Dynamic Place Award ‘Person of the Year’ –for achieving a new standard in healing environment created at Glasgow Homoeopathic Hospital (www.ghh.info). At a personal level he says, ‘I am now old enough to have made major mistakes and young enough to learn from them. Fortunately, I am not as old as I used to be.’ Copyright © 2004 Whurr Publishers Ltd.
Narratives of hope: Keisha's story
Authors: Turner de Sales
Published: March 2006

In this paper, a case study exemplar is discussed to illustrate how the phenomenon of hope was explicated for one Australian youth. A total of 10 youths between the ages of 15 and 24 participated in this study. Data were collected using photographs taken by the participants and in‐depth interviews. Gadamerian hermeneutic phenomenology was used to conduct this study and, to become immersed in the data, the researcher devised a unique method of analysis consistent with the study's philosophical underpinnings. The findings illuminate the phenomenon of hope, attesting to its importance to the study participants. Copyright © 2004 Whurr Publishers Ltd.
An exploration into the continuity of consciousness
Authors: B'Hahn Carmella
Published: March 2006

Can we explain the wisdom we perceive in the eyes of newborn babies? Is the simple answer that they are incredibly wise? Is birth perhaps the death of an expanded consciousness, a state to which we are reborn with immense relief at the moment of physical death? Most eastern philosophy has long held this belief, but the body of evidence to support this hypothesis is also now burgeoning in the West. This paper examines some of that evidence, looking at what informs us of the existence of consciousness before birth and after death. It also addresses the importance of this knowledge reaching healthcare professionals, particularly those who work closely with birth, death and dying, and the grieving process. Copyright © 2004 Whurr Publishers Ltd.
Photoluminescence of cerium–europium co‐doped SiO2 phosphor prepared by a sol–gel process
Authors: Ntwaeaborwa O. M. , Swart H. C. , Kroon R. E. , Holloway P. H. , Botha J. R.
Published: March 2006

Ce3+ and Eu3+ ions were simultaneously incorporated into a SiO2 matrix by a sol–gel process, resulting in a phosphor that could be used in applications such as fluorescent lamps, solid state lasers, optical waveguides and field emission displays. Variation between blue and red emissions was obtained when co‐doped SiO2:Ce,Eu powders with concentrations ranging from 0 to 5 mol% were exposed to ultraviolet light. An enhanced photoluminescence (PL) intensity from Ce3+, probably due to energy transfer from Eu3+, was observed for activator concentrations ranging from 0 to 1 mol%. Comparatively low PL intensities, especially from Ce3+, associated with concentration‐quenching were observed for activator concentrations in the range of 2–5 mol%. Copyright © 2006 John Wiley & Sons, Ltd.
A novel sample pretreatment method using supercritical fluids for the analysis of atmospheric environmental samples by means of time‐of‐flight secondary ion mass spectrometry
Authors: Sakamoto Tetsuo , Yamamoto Azusa , Owari Masanori , Nihei Yoshimasa
Published: March 2006

A novel sample pretreatment method was developed for time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) analysis of organic matter in environmental particles. This method employs the supercritical fluid extraction (SFE) technique. In SFE, the extraction efficiencies of aliphatic and aromatic compounds are largely different from each other at a certain fluid condition, e.g. pressure and temperature. Two‐step SFE (two fluid conditions) of diesel exhaust particles (DEPs) showed that n‐alkanes and polycyclic aromatic hydrocarbons (PAHs) can be separately extracted by changing both the fluid pressure and temperature from low to high. This selective extraction was applied to the sample preparation of TOF‐SIMS analysis, where n‐alkanes are ‘unwanted’ constituents if PAHs are the analytical targets. The obtained TOF‐SIMS spectrum of the particles after SFE was simplified and the mass peaks of PAHs were easily assigned, because n‐alkanes were selectively removed in the SFE pretreatment. Copyright © 2006 John Wiley & Sons, Ltd.
Fabrication of epitaxial MIM structures on NiAl(110) studied by XPS and low energy electron diffraction
Authors: Yoshitake Michiko , Song Weijie
Published: March 2006

Fabrication of a metal‐insulator‐metal (MIM) structure of the Au/Pd/Al2O3/NiAl(110) system was investigated in situ using XPS and low energy electron diffraction (LEED). A well‐ordered Al2O3 film thicker than 0.5 nm was grown through the controlled oxidation of NiAl(110) at elevated temperature. Nearly layer‐by‐layer growth of Pd film on a 0.85‐nm thick, well‐ordered Al2O3 was observed by XPS when Pd was slowly deposited at room temperature. Binding energy shifts were not observed for the photoelectron peaks from the alumina or the substrate, but a binding energy shift was observed in the Pd peak during Pd deposition until 1.3 ML. The Pd layer produced hexagonal spots in LEED, suggesting the epitaxial growth of the (111) plane parallel to the surface. The Au layer was deposited on the Pd layer at room temperature under a slow deposition rate and also showed hexagonal spots in LEED. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of hydrogen contained in passivated poly‐Si and microcrystalline‐Si by ERDA technique
Authors: Boldyryeva H. , Honda S. , Mackova A. , Mates T. , Fejfar A. , Kočka J.
Published: March 2006

Polycrystalline Si (poly‐Si) thin films produced by atmospheric pressure chemical vapour deposition (APCVD) were treated by hydrogen passivation in the remote plasma system. Such materials could be potentially used for photovoltaics applications. The purpose of the present study was to investigate the effects of hydrogen passivation on poly‐Si thin film properties, such as hall mobility and photoluminescence. Elastic recoil detection analysis (ERDA) was used to determine the depth distribution and concentration of hydrogen. ERDA was also applied to determine the hydrogen content of amorphous/microcrystalline silicon produced by plasma enhanced chemical vapour deposition (PECVD) with various dilution ratios of the working gases (H2 and SiH4). A dependence of the hydrogen content on the crystallinity was observed. Copyright © 2006 John Wiley & Sons, Ltd.
Characteristics of silica‐coated TiO2 and its UV absorption for sunscreen cosmetic applications
Authors: Jaroenworaluck A. , Sunsaneeyametha W. , Kosachan N. , Stevens R.
Published: March 2006

Nanosized TiO2 is used extensively in sunscreen cosmetics as an inorganic UV absorber that can allow an optically transparent film to be applied to human skin. TiO2 is known to exist in three crystal forms: anatase, brookite and rutile. The rutile phase is generally used as a component in sunscreen cosmetics because of its higher UV absorption. A surface coating can be added to nanosized TiO2 to enhance its UV absorption by a different light diffraction mechanism. Silica‐coated nanosized TiO2 is examined in this study for this purpose. The nanosized TiO2 has been synthesized using hydrolysis of tetra‐isopropylorthotitanate (TIPT) as a precursor. After a calcination process, nanosized TiO2 was formed and subsequently its surface modified by coating with tetraethoxysilane (TEOS) as the source of the silica. The same coating method was applied to nanosized commercial TiO2, to compare the surface characteristics. The resulting powders of coated TiO2 were examined by transmission electron microscopy (TEM) and analyzed by energy dispersive analysis (EDS), respectively. UV‐vis spectroscopy was used to study the differences and effectiveness of the coated and uncoated TiO2. Copyright © 2006 John Wiley & Sons, Ltd.
Auger photoelectron coincidence spectroscopy: simplifying complexity
Authors: van Riessen G. A. , Thurgate S. M.
Published: March 2006

The use of X‐ray photoelectron spectroscopy (XPS) is expanding rapidly with the advent of more convenient, high‐resolution laboratory‐based instruments. The increase in the numbers and distribution of synchrotrons has also fuelled this burgeoning interest. Powell (C. J. Powell, J. Vac. Sci. Technol. A 21 (S42) 2003) has shown that the number of papers published on or using XPS has doubled in the past 10 years. He reports that there are in excess of 3000 papers published using XPS data each year across a wide range of applications, making it the most important technique for the determination of the composition of nano‐scale surface films. Yet XPS and the associated technique of Auger‐electron spectroscopy (AES) are not yet developed to the stage where the data and its interpretation are unambiguous. Auger photoelectron coincidence spectroscopy (APECS) provides a means of simplifying spectra, allowing for the decomposition of these into components that have a common origin. The spectra so produced provide a unique opportunity to test theory. In this paper, we will review recent progress in developing better APECS spectrometers and illustrate the power of APECS with new data acquired by these. Copyright © 2006 John Wiley & Sons, Ltd.
SysML and UML 2 support for activity modeling
Authors: Bock Conrad
Published: March 2006

This article describes activity modeling as specified by the Systems Modeling Language (as specified by the SysML Merge Team, http://doc.omg.org/ad/2006‐02‐01, February 2006) and the finalization of the Unified Modeling Language version 2 (UML 2). It reviews and updates an earlier proposed alignment between Enhanced Functional Flow Block Diagrams (EFFBD), UML 2 Activities, and requirements developed by the International Council on Systems Engineering and Object Management Group. It presents a spectrum of activity modeling techniques, ranging from a widely used systems engineering diagram, the EFFBD, to continuous flow modeling. The techniques include control capabilities, continuous system concepts, and others related to functional decomposition and allocation. The article also describes refinements of activity modeling concepts identified during SysML development. © 2006 Wiley Periodicals, Inc. Syst Eng 9:160–186, 2006
PaladinRM: Graph‐based visualization of requirements organized for team‐based design
Authors: Austin Mark , Mayank Vimal , Shmunis Natalya
Published: March 2006

When requirements are organized into levels for team development, graph structures are needed to describe the comply and define relationships among requirements. Present‐day requirements engineering tools employ graph‐based structures for the storage and representation of engineering requirements, but often use a tree‐based model to display relationships among requirements. This strategy of development simplifies the details of implementation for visualization purposes, but unfortunately also causes gaps to appear between the visual representation and the underlying graph‐based data structures. Systems engineers currently use manual procedures to identify and close these gaps. To mitigate the limitations of this slow and error prone process, this paper describes the formulation of algorithms and development of a Java‐based requirements visualization tool called PaladinRM. PaladinRM can read a tree representation of requirements exported from a database, and construct and visualize the block diagram representation with all duplicate nodes removed. The implementation of PaladinRM makes extensive use of Semantic Web technologies. © 2006 Wiley Periodicals, Inc. Syst Eng 9: 129–145, 2006
Effect of cutting height of Napier grass on rumen degradation and in vitro dry matter digestibility
Authors: Zewdu Tessema , Baars RMT
Published: March 2006

Plant height at cutting had a significant inverse effect on rumen organic matter digestibility (OMD), neutral detergent fibre degradability (NDFD) and in vitro dry matter digestibility (IVDMD). There was a positive linear correlation between IVDMD and both OMD and NDFD at 48–120 h. The fertilizer treatments did not yield any significant difference on OMD, NDFD or IVDMD. Copyright © 2003 Whurr Publishers Ltd
Variation in size, protein, cyanide and tannin contents of lima bean (Phaseolus lunatus)
Authors: Offei SK , Asante IK , Danquah EY
Published: March 2006

Thirty one accessions had 100‐seed weight of 23.8 to 71.8 g and protein contents from 20.4 to 30.3%. There was little variation in cyanide content. Tannin contents varied tenfold among the accessions and increased with colour. Copyright © 2003 Whurr Publishers Ltd
Effect of fruit perianth on quality and storability of Gondeila and Barakawi dates
Authors: Abu‐Goukh Abu‐Bakr A , Shattir Adil E , Abdelbagi Azhari O
Published: March 2006

Gondeila and Barakawi dates stored without perianths had 24.0 and 9.8% respectively insect infestation after 6 months. Fruits stored with perianths intact or replaced by wax showed little infestation late during storage. Dates stored without perianths showed significant reduction in total and reducing sugars, proteins and phenolics. There was a positive correlation between insect infestation and reduction in total and reducing sugars, proteins and phenolics during storage. Copyright © 2003 Whurr Publishers Ltd
Effect of silver nitrate on in vitro shoot growth of coffee
Authors: Giridhar P , Indu EP , Vijaya Ramu D , Ravishankar GA
Published: March 2006

Shoots of arabica and robusta coffee showed increased growth when incubated on MS medium containing silver nitrate and indole acetic acid and benzyladenine. Different concentrations of silver nitrate had the greatest effect on the various growth parameters. Copyright © 2003 Whurr Publishers Ltd
Seasonal occurrence, spatial distribution and control of the cocoa stem borer, Eulophonotus myrmeleon, in Ghana
Authors: Adu‐Acheampong R , Ackonor JB , Sarfo JE , Padi B
Published: March 2006

Eulophonotus myrmeleon larvae had population peaks in May and September and this occurred mainly up to 1.5 m above ground level. Adult emergence showed peaks in April and October. Larvae could be controlled by squeezing aluminium phosphide paste into the exit holes or by plugging them with pieces of wood. Copyright © 2005 John Wiley & Sons, Ltd
The response of the forest tree Terminalia superba to weed competition and intercropping in the savanna of Kombé, Congo
Authors: N'zala D , Ikoungou C
Published: March 2006

The weed species occurring with Limba (Terminalia superba) saplings are reported. Weeds affected tree growth only at some stages in the first year and intercropping with groundnut, maize and soyabean had no adverse effect. Copyright © 2003 Whurr Publishers Ltd
Improving maize and cowpea seed quality through seed processing
Authors: Asiedu EA , Danquah OA , Adusei‐Akowuah P , Van Gastel AJG
Published: March 2006

A medium (110‐day) maturing Quality Protein Maize variety and an early (60‐day) cowpea variety, were harvested, shelled/threshed and mechanically cleaned using an air‐screen cleaner, followed by a gravity separator. This gave significant increases in field emergence, laboratory germination, pure seed and 1000‐seed weight of maize and cowpea. Germination and purity of both of the processed seeds far exceeded the Ghanaian minimum standards. Copyright © 2003 Whurr Publishers Ltd
Influence of growth‐promoting substances on sprouting of white yam (Dioscorea rotundata) setts
Authors: Suja G , Nair VM , Saraswathy P , Geetha Kumari VL
Published: March 2006

Sett treatment with 2% thiourea induced early sprouting and longer sprouts that led to a vigorous crop. Potassium nitrate had no pronounced effect. The farmers' practice of dipping the setts in cow dung slurry or smearing with wood ash resulted in poor, slow and staggered sprouting. Indole acetic acid had the least effect on sprouting. Copyright © 2003 Whurr Publishers Ltd
Effect of phosphorus fertilizer on root‐knot nematode disease of soyabean
Authors: Agu CM
Published: March 2006

The highly resistant soyabean cultivar TGx536‐02D became susceptible to Meloidogyne javanica at 1.0–2.5 g/plant of single superphosphate applied. The moderately resistant TGx 813‐6D became more susceptible at 0.5–2.5 g/plant of the fertilizer. The highly susceptible cultivar Samoy‐1 was not affected by 2.5 g/plant. Copyright © 2003 Whurr Publishers Ltd