bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Investigation into the Origins of Time-Dependent Variation in Penetration Rates with Charnley Acetabular Cups—Wear, Creep or Degradation?
Authors: Isaac G H , Dowson D , Wroblewski B M 
Published: February 2007

The total penetration of femoral heads into acetabular cups is achieved by a combination of long-term wear and early non-recoverable deformation or creep. The former is important in determining the total rate of production of polyethylene wear debris, recently implicated in the development of osteolysis and loosening, while the latter contributes to the overall penetration and the possibility of neck impingement in some designs of implants. Attention is drawn to the need to evaluate and to separate out these two physical processes in the assessment of clinical penetration rates. This is particularly important with more recent designs and combinations of materials, which are capable of operating with much reduced wear rates. Measurements of the penetrations of metallic femoral heads into polyethylene acetabular cups in 87 explanted Charnley hip arthroplasties from 85 patients are reported and assessed. The vast majority of the acetabular cups had been sterilized by gamma irradiation and the established shadowgraph technique was used to determine the penetrations. The average implantation time was 8.75 years, with a range from 0.2–18.6 years and the average age was 55 years, covering the span 19–73 years. The influence of sterilization procedure, implantation time and patient age are considered. Assessments of the relative magnitudes of wear and non-recoverable deformation are made by different statistical techniques and compared with previously reported data from clinical and laboratory studies.
Auto-Tuning of Low-Order Controllers by Direct Manipulation of Closed-Loop Time Domain Measures
Authors: Lawrence A J , Harris C J 
Published: February 2007

Many controller tuners are based on linear models of both the controller and process. Desired performance is often predetermined or adjusted in a manner that is not directly related to the desired response. All physical processes contain non-linearities, commonly of the actuator saturating type, and many controllers contain heuristics for implementation in real systems, such as anti-integral wind-up in PID (proportional integral differential) controllers. For different processes a range of closed-loop response shapes are desired, often described by features of the response such as rise time, overshoot and settling time. This paper investigates the possibility of basing controller tuning on closed-loop system response data such that desired performance is incorporated directly in terms of familiar time domain features or labels, thus eliminating the need for a mathematical process model and repeated tuning reformulations to achieve the desired performance. A controller tuning method named label-based neuro-tuning (LBNT) is developed and analysed by application to PID controller tuning for process models indicative of real process behaviour. Simulations and numerical investigation indicate that LBNT is a viable technique for the tuning of low-order SISO (single-input-single- output) controllers. Tuning is straightforward, flexible and copes well with process parametric changes and performance specification reformulation. The drawbacks are a complicated pretune phase, a limited selection of suitable labels and a difficulty in defining general classes of tuning problems for its application. The technique is not based on the assumption of process linearity, but due to the inability to characterize classes of input signals and operating points the types of process non-linearity are restricted. The controller may be non-linear, but must be structurally predetermined, and an input/output process model of arbitrary structure is required.
Non-Linear Robust Control Designs for a Remotely Operated Underwater Vehicle Depth Control System
Authors: Trebi-Ollennu A , White B A 
Published: February 2007

This paper describes the heave and pitch control of a non-linear longitudinal model of a remotely operated vehicle (ROV) using three robust non-linear control techniques. The techniques are based on input-output (I/O) linearization, comprising basic I/O linearization control, I/O linearization with sliding mode control and I/O linearization with adaptive fuzzy systems. Robustness of the designs is investigated by examining the closed-loop zero dynamics, which are shown to be bounded. The robustness of each control scheme is also investigated by varying the ROV hydrodynamic coefficients by 50 per cent. Simulation results are presented to compare the control schemes.
Single-Axial Groove Journal Bearings: Static Characteristics and a Temperature Prediction Technique
Authors: Pliakas P , Parkins D W 
Published: February 2007

This paper describes measured data for the static characteristics of a plain hydrodynamic journal bearing with a single-axial oil supply groove located in the direction of the load vector. The journal centre static locus was measured for a variety of speed/load combinations with three values of length-diameter ratio. Full descriptions of the experimental procedures are given. Comparison is made with corresponding data from the appropriate ESDU data item. An extensive set of oil-film temperatures were also taken at each test condition. Empirical equations were established from these measured temperature profiles. These were shown to reliably predict the complete temperature field, together with the maximum and its location, over the entire experimental range. Equations are formulated in a manner that is usable by the designer.
The Effect of Engine Operating Temperature on Valve Train Wear: Mechanistic Understanding Through Used Oil Analysis
Authors: Shannon I , Bell J C , Cadu J 
Published: February 2007

Analysis of used oils from a series of Peugeot TU-3 engine tests has been performed to investigate the effect of engine operating temperature on valve train wear in this engine. Iron content of intermediate and end-of-test used oil samples has been used as a monitor of valve train wear during the test and has indicated that a significant proportion of the wear occurs during the initial low-temperature phase of the test. Analysis of used oils using 31phosphorus nuclear magnetic resonance spectroscopy (3lP NMR) suggests that this is associated with low rates of zinc dialkyldithiophosphate (ZDTP) degradation during low-temperature operation, resulting in levels of extreme-pressure (e.p.)/anti-wear materials which are insufficient to provide the necessary wear protection. Modification of the TU-3 test procedure, such that the high operating temperature phase precedes the low-temperature phase, results in very much lower observed levels of valve train wear.31 P NMR analysis indicates that this is associated with a much more rapid buildup of active ZDTP degradation products during initial high-temperature operation, which can then provide the necessary anti-wear protection during subsequent low-temperature operation.
Development of a resource protection and waste strategy for water use by the agricultural sector
Authors: Ligthelm M.E. , Ranwedzi R. , Morokane M. , Senne M. 
Published: February 2007

The South African Department of Water Affairs and Forestry (DWAF) has started developing a strategy to regulate activities and water uses by the agricultural sector that could impact on the water resource quality. The aim would not be to over-regulate the sector, but to protect the water resource where necessary. Most of these activities constitute diffuse sources of potential pollution. The strategic process will start with investigative discussions with major stakeholders and determining the strategic context and current situation. The latter will consist of a detailed literature and stakeholder survey, and an evaluation of existing agricultural activities. The next steps of determining a vision and the setting of strategic objectives will be done with active participation by the major players. An action plan will be developed to achieve the set objectives.
Important components of the strategy will be to: classify activities according to their risk to the water resource, taking into account the sensitivity of the water resource; set regulatory measures in accordance with the risk posed by the activity (measures could include the promulgation of regulations, general authorisations and/or issuing of licenses); harmonise and link the process with existing relevant processes and guidelines within DWAF and other government departments; review existing guidelines; sign agreements with relevant government departments and the agricultural sector; and provide training, built capacity and raise awareness during and after the process.
Phase Segregation in Thin Films of Conjugated Polyrotaxane– Poly(ethylene oxide) Blends: A Scanning Force Microscopy Study
Authors: Sardone L. , Williams C. C. , Anderson H. L. , Marletta G. , Cacialli F. , Samorì P. 
Published: February 2007

AbstractScanning force microscopy (SFM) is used to study the surface morphology of spin‐coated thin films of the ion‐transport polymer poly(ethylene oxide) (PEO) blended with either cyclodextrin (CD)‐threaded conjugated polyrotaxanes based on poly(4,4′‐diphenylene‐vinylene) (PDV), β‐CD–PDV, or their uninsulated PDV analogues. Both the polyrotaxanes and their blends with PEO are of interest as active materials in light‐emitting devices. The SFM analysis of the blended films supported on mica and on indium tin oxide (ITO) reveals in both cases a morphology that reflects the substrate topography on the (sub‐)micrometer scale and is characterized by an absence of the surface structure that is usually associated with phase segregation. This observation confirms a good miscibility of the two hydrophilic components, when deposited by using spin‐coating, as suggested by the luminescence data on devices and thin films. Clear evidence of phase segregation is instead found when blending PEO with a new organic‐soluble conjugated polymer such as a silylated poly(fluorene)‐alt‐poly(para‐phenylene) based polyrotaxane (THS–β‐CD–PF–PPP). The results obtained are relevant to the understanding of the factors influencing the interfacial and the intermolecular interactions with a view to optimizing the performance of light‐emitting diodes, and light‐emitting electrochemical cells based on supramolecularly engineered organic polymers.
Copper/Polyimide Heterojunctions: Controlling Interfacial Structures Through an Additive‐Based, All‐Wet Chemical Process Using Ion‐Doped Precursors
Authors: Ikeda S. , Yanagimoto H. , Akamatsu K. , Nawafune H. 
Published: February 2007

AbstractHeterojunctions comprising copper thin films and polyimide underlayers are exploited as an important system for generating flexible microelectronic circuit elements. A fully additive‐based chemical method that allows metallization of polyimide films with copper by the in situ reduction of copper ions doped in surface‐modified polyimide precursors is reported. It is shown that dimethylamine borane is a good reducing agent for copper ions initially complexed with carboxylate anions in the hydrolyzed polyimide layers. This reduction allows diffusion of copper ions towards the film surface to form copper thin films, and simultaneously controls the fabrication of interfacial microstructures between the copper and underlying polyimide. The formation of copper thin films and composite layers is elucidated by glow‐discharge optical emission spectrometry depth profiling, scanning electron microscopy, and cross‐sectional transmission electron microscopy studies, and it is shown that the final microstructure at the copper/polyimide interface is dependent upon experimental variables: a larger amount of copper ions incorporated into the modified layers and a higher reduction rate result in the formation of a granular layer containing smaller copper nanoparticles near the film surface. The granular layers thus formed are found to play a critical role in achieving strong adhesion between metal thin films and the substrate, owing to the increased contact area and hence the increased work of adhesion between them. These results have important implications for realizing a novel adhesion scheme between deposited metals and underlying dielectrics based on nanoscale interlocking through metal nanoparticles.
Streaming potential characterization of LBL membranes on porous ceramic supports
Authors: Chen Yiwei , Xiangli Fenjuan , Jin Wanqin , Xu Nanping 
Published: February 2007

AbstractAn in‐situ characterization of the growth of the self‐assembled polyelectrolyte membranes on the porous support was conducted by applying transmembrane streaming potential measurement via surface charge monitoring. The membranes were prepared by layer‐by‐layer alternative deposition of poly (allylamine hydrochloride) and poly (styrenesulfonate) on porous ceramic supports. The surface charge variations of membranes as functions of different top‐assembled materials and numbers of deposited cycles were investigated. Different top‐assembled materials make isoelectric points of the as‐prepared membranes drift in opposite directions and also lead to symmetrical signal changes of zeta‐potential in salt solutions at the isoelectric points of the supports. Ex‐situ characterizations, including scanning electron microscopy, atomic force microscopy, and energy dispersive X‐ray spectroscopy, also confirm the alternative deposition of polyelectrolytes. It is demonstrated that the transmembrane streaming potential measurement is effective in studying the growth of layer‐by‐layer membranes on porous support. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Health-related quality of life after gastric banding
Authors: Mathus-Vliegen E M H , de Wit L T 
Published: February 2007

Abstract

Background
Bariatric surgery ameliorates obesity-associated diseases, resulting in psychological and social benefits. Long-term studies of its effects on quality of life (QOL) assessed with well established instruments are lacking. This prospective study investigated the long-term effects of gastric banding on health-related QOL using an obesity-specific validated measure.

Methods
The Health Related Quality of Life (HRQL) questionnaire was completed by 50 severely obese patients before surgery and at 1, 2·5 and 5 years after gastric banding. Ninety-eight subjects with normal weight, matched for age, sex and education, also completed the HRQL questionnaire as controls.

Results
Surgery was successful in all patients. Mean excess weight loss after 1, 2·5 and 5 years was 42·1, 42·2 and 41·6 per cent respectively. General wellbeing, health distress, depression, perceived attractiveness and self-worth improved significantly over the 5 years and, except for general wellbeing, were still improving after 5 years. There were increases in physical activity and work productivity. Successful weight loss was the main determinant of general wellbeing and health distress, and these were adversely affected by band-related complications. In subjects with a body mass index below 30 kg/m2, scores improved to values for subjects of normal weight.

Conclusion
Bariatric surgery resulted in sustained improvement in health-related QOL even though not all excess weight was lost. Normalization of health-related QOL may necessitate greater weight losses.
Secophnane‐Type Alkaloids from Daphniphyllum oldhami
Authors: Mu Shu‐Zhen , Yang Xian‐Wen , Di Ying‐Tong , He Hong‐Ping , Wang Ye , Wang Yue‐Hu , Li Ling , Hao Xiao‐Jiang 
Published: February 2007

AbstractFour new alkaloids, daphnioldhanins D–G (1–4, resp.), together with five known alkaloids, daphmacropodine (5), secodaphniphylline (6), deoxycalyciphylline B (7), deoxyisocalyciphylline B (8), and daphmanidin A (9), were isolated from the roots of Daphniphyllum oldhami. Their structures were elucidated on the basis of spectroscopic data and chemical methods. Compound 1 at 2.0 μM showed potent antioxidant activity against H2O2‐induced impairment in PC12 cells.
Selective Synthesis and Reactivity of η5‐Arylcyclohexadienyliron Complexes
Authors: Owen David A. , Malkov Andrei V. , Palotai Ian M. , Roe Caroline , Sandoe Elizabeth J. , Stephenson G. Richard 
Published: February 2007

AbstractA series of aryl‐substituted cyclohexadienyliron complexes have been prepared by a general procedure that determines regioselectivity by correctly positioning leaving groups in the precursor complexes. The aryl groups at 1‐C or 2‐C have been shown to be ω directing by the study of reactions with a representative range of nucleophiles, and these regioselectivity properties have been related to the spectroscopic properties of the cationic cyclohexadienyliron complexes. A high level of electron‐donating substituents on the arene, or switching between the [Fe(CO)3] and [Fe(CO)2PPh3] series, reduces the minor ipso pathway, improving regiocontrol. Placing opposed directing groups in the arylcyclohexadienyliron complexes reverts reactivity to the ipso pathway with stabilised enolate nucleophiles, and when the additional directing group reinforces the effect of the aryl group, the ipso pathway is stopped.
2,4,5‐Trinitroimidazole‐Based Energetic Salts
Authors: Gao Haixiang , Ye Chengfeng , Gupta Om D. , Xiao Ji‐Chang , Hiskey Michael A. , Twamley Brendan , Shreeve Jean'ne M. 
Published: February 2007

Abstract2,4,5‐Trinitroimidazolate (TNI) salts with “high‐nitrogen” cations tend to be highly hydrogen bonded and have heats of formation ranging up to 616 kJ mol−1. Density, oxygen balance, and thermostability are enhanced by the presence of TNI. Based on theoretical calculations, all of the new salts are potential propellants.
Impact of a 21‐gene RT‐PCR assay on treatment decisions in early‐stage breast cancer
Authors: Lyman Gary H. , Cosler Leon E. , Kuderer Nicole M. , Hornberger John 
Published: February 2007

AbstractBACKGROUNDThe prognostic accuracy for distant recurrence‐free survival using a 21‐gene reverse‐transcriptase polymerase chain reaction (RT‐PCR) assay underwent validation in 668 lymph node‐negative, estrogen receptor‐positive women with early‐stage breast cancer receiving tamoxifen on National Surgical Adjuvant Breast Program (NSABP) B‐14. The predictive accuracy for treatment efficacy also underwent validation in 651 patients randomized on NSABP B‐20 and 645 patients on NSABP B‐14.METHODSPatients were classified as high (recurrence score [RS] ≥ 31), intermediate (RS 18–30), or low (RS < 18) risk for distant recurrence at 10 years. Cost‐effectiveness ratios were estimated for RS‐guided treatment compared with either tamoxifen alone or the combined chemotherapy and tamoxifen.RESULTSDistant recurrence was reported in RS low‐risk, intermediate‐risk, and high‐risk patients at 10 years in 3.7%, 17.8%, and 38.3% receiving tamoxifen alone and 5.0%, 10.1%, and 11.1% receiving the chemotherapy and tamoxifen. RS‐guided therapy is associated with a gain in individual life expectancy of 2.2 years compared with tamoxifen alone, whereas it is associated with similar life expectancy to that seen with the chemotherapy and tamoxifen strategy. RS‐guided therapy is estimated to provide a net cost savings of $2256 compared with chemotherapy and tamoxifen with an incremental cost‐effectiveness ratio of $1944 per life year saved compared with tamoxifen alone.CONCLUSIONSTreatment decisions based on RS‐guided therapy compared with tamoxifen alone are associated with greater efficacy with acceptable cost‐effectiveness ratios, and associated with similar efficacy and lower cost compared with chemotherapy and tamoxifen for patients with lymph node‐negative, estrogen receptor‐positive early‐stage breast cancer. Cancer 2007 © 2007 American Cancer Society.
Mutagenesis studies in transgenic Xenopus intermediate pituitary cells reveal structural elements necessary for correct prion protein biosynthesis
Authors: van Rosmalen Jos W.G. , Martens Gerard J.M. 
Published: February 2007

AbstractThe cellular prion protein (PrPC) is generally accepted to be involved in the development of prion diseases, but its physiological role is still under debate. To obtain more insight into PrPC functioning, we here used stable Xenopus transgenesis in combination with the proopiomelanocortin (POMC) gene promoter to express mutated forms of Xenopus PrPC fused to the C‐terminus of the green fluorescent protein (GFP) specifically in the neuroendocrine Xenopus intermediate pituitary melanotrope cells. Similar to GFP‐PrPC, the newly synthesized GFP‐PrPCK81A mutant protein was stepwise mono‐ and di‐N‐glycosylated to 48‐ and 51‐kDa forms, respectively, and eventually complex glycosylated to yield a 55‐kDa mature form. Unlike GFP‐PrPC, the mature GFP‐PrPCK81A mutant protein was not cleaved, demonstrating the endoproteolytic processing of Xenopus PrPC at lysine residue 81. Surprisingly, removal of the glycosylphosphatidylinositol (GPI) anchor signal sequence or insertion of an octarepeat still allowed N‐linked glycosylation, but the GFP‐PrPCΔGPI and GFP‐PrPCocta mutant proteins were not complex glycosylated and not cleaved, indicating that the GPI/octa mutants did not reach the mid‐Golgi compartment of the secretory pathway. The transgene expression of the mutant proteins did not affect the ultrastructure of the melanotrope cells nor POMC biosynthesis and processing, or POMC‐derived peptide secretion. Together, our findings reveal the evolutionary conservation of the site of metabolic cleavage and the importance of the presence of the GPI anchor and the absence of the octarepeat in Xenopus PrPC for its correct biosynthesis. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007.
Micropatterning of 2D colloidal crystals using area‐selective immobilization of particles by laser beam irradiation onto azopolymer surface
Authors: Kato Takahiro , Tawata Masahiro , Shimoyama Hiroshi , Ikawa Taiji , Watanabe Osamu 
Published: February 2007

AbstractWe proposed a technique which arranges particles in a regular two‐dimensional array on an azopolymer surface, followed by immobilizing them in an arbitrary pattern on the surface, and studied its prospect. Azopolymer has the two properties of being able “to form a surface relief structure” and “to immobilize particles in the surface” by light irradiation. First, the former characteristic was used to form a periodic two‐dimensional relief pattern template on an azopolymer surface by two‐beam interference exposure, and the particles were arranged on the surface. Then the latter characteristic was used to selectively immobilize particles by light irradiation, and unimmobilized particles were removed by washing. As a result, we demonstrated that particles could be arranged in a regular two‐dimensional array in a square structure and a hexagonal structure, and a two‐dimensional photonic crystal waveguide structure could be easily fabricated by the micropatterning of particles. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(3): 1–8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20307
A force‐reflecting friction‐free bilateral system based on a twin drive control system with torsional vibration suppression
Authors: Ohba Yuzuru , Ohishi Kiyoshi 
Published: February 2007

AbstractThis paper proposes a new friction‐free bilateral system based on twin drive control system considering resonant frequency for bilateral systems. The twin drive system consists of two motors which are coupled by the differential gear. The output torque becomes a different torque of both motors. The nonlinear friction torque of the twin drive system can be easily compensated. However, the resonant frequency and the antiresonant frequency caused by the tensional vibration exist. This paper proposes a new two‐mass model of twin drive system that supresses torsional vibration by state feedback. The proposed control method is applied to the bilateral robot, and the effectiveness of the control method is confirmed by the experimental results. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(1): 72–79, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20355