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Acceptable Results (acceptable + result)
Selected AbstractsEconomic aspects of diabetic foot care in a multidisciplinary setting: a reviewDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 5 2007Giovanni A. Matricali Abstract Background To evaluate the economic aspects of diabetic foot care in a multidisciplinary setting. Method A review of the English language literature, published from 1966 to November 2005. Results The results of available studies on the cost-of-illness of diabetic foot problems are difficult to compare. Nevertheless trends concerning excess of costs, protraction in time of costs, positive correlation to severity of ulcer and/or peripheral vascular disease, contribution of in-hospital stay and length of stay, and the patient's own contribution to total costs, are obvious. Only a few cost-effectiveness and cost-utility studies are available. Most use a Markov based model to predict outcome and show an acceptable result on long-term. Conclusions Diabetic foot problems are frequent and are associated with high costs. A multidisciplinary approach to diabetic foot problems has proved to be cost saving with regard to cost of treatment itself. Nevertheless, it remained unclear if these savings could offset the overall costs involved in implementing this kind of approach. The few studies that address this issue specifically all show an acceptable cost-effectiveness, but often the profit will be evident after some years only, because long-term costs are involved. Based on these data, policymakers should foresee sufficient reimbursement for preventive and early curative measures, and not only for ,salvage manoeuvres'. Copyright © 2007 John Wiley & Sons, Ltd. [source] A case of small-cell gastric carcinoma with an adenocarcinoma component and hepatic metastases: treatment with systemic and intra-hepatic chemotherapyEUROPEAN JOURNAL OF CANCER CARE, Issue 5 2007T. CIOPPA md Primary small-cell carcinoma (SmCC) of the stomach is a rare neoplasm with a poor prognosis and unclear histogenesis: to date, only 50 cases, including ours, have been reported in the literature. In the World Health Organization gastrointestinal tumours' classification, SmCC of the stomach has been recognized as an ,independent entity affecting the stomach'. In this paper, the authors present a clinical case and the surgical treatment of an adult with a SmCC of the stomach associated with gastric adenocarcinoma. After laparotomy, a large neoplasm with locoregional extension and multiple liver metastases were found. A palliative resection, subtotal gastrectomy, was performed, followed by systemic and intra-hepatic chemotherapy: computed tomography scan demonstrated a marked response, but the patient died 15 months after the operation. A review of the literature showed that the diagnosis of gastric SmCC is based on immunohistochemical findings. Our experience confirmed the high aggressiveness of this neoplasm, which is generally diagnosed in advanced stage and is unresponsive to chemotherapy, but the combined use of systemic and intra-hepatic chemotherapy shows an acceptable result in a palliative care perspective. [source] Use of sweet sorghum juice for lactic acid fermentation: preliminary steps in a process optimizationJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2010Kata Hetényi Abstract BACKGROUND: Lactic acid has many applications in the chemical industries and it can be produced economically by microorganisms using biomass raw materials of different origins. Sweet sorghum juice is a high sugar content raw material with potential for lactic acid production because after hydrolysis of its sucrose content the remaining glucose and fructose can supply the carbon demand of most lactic acid bacteria. However, satisfying the nitrogen and B-vitamin needs of the bacteria by supplementation with yeast extract and/or other alternative nitrogen-containing supplements can make the process too expensive. RESULTS: Using a statistical optimization process much of the yeast extract can be replaced by a cheaper alternative nitrogen source, namely wheat gluten. This resulted in a fermentation with 99% lactic acid yield and 3.04 g L,1 h,1 volumetric productivity. CONCLUSION: Using response surface methodology (RSM) media optimization was performed for lactic acid fermentation with an industrially acceptable result, reducing the costs of raw materials by half, replacing yeast extract by an alternative nitrogen source and applying yeast extract only as a source of micro-elements (vitamins, salts, etc.) Copyright © 2010 Society of Chemical Industry [source] Using Opaquers under Direct Composite Resin Veneers: An Illustrated Review of the TechniqueJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 6 2003LUÍS ANTÔNIO FELIPPE DDS ABSTRACT In restorative dentistry direct composite resin materials can be used to conservatively resolve many esthetic problems. Opaque resins are often necessary to mask discolorations and/or dark backgrounds when restoring anterior teeth. This article presents a direct composite resin veneer technique using opaquers. Potential problems with the tone of restorations after the use of opaquers are discussed. Advantages, limitations, and the clinical technique are presented. Training, as well as attention to the technique, contributes to an acceptable result. CLINICAL SIGNIFICANCE Resinous opaquers can be used as a valid adjunct to the direct composite resin veneer technique when conservatively restoring dark teeth. [source] Interlaboratory Comparison of Cytomegalovirus Viral Load AssaysAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009X. L. Pang To assess interlaboratory variability in qualitative and quantitative cytomegalovirus (CMV) viral load (VL) testing, we distributed a panel of samples to 33 laboratories in the USA, Canada and Europe who performed testing using commercial reagents (n = 17) or laboratory-developed assays (n = 18). The panel included two negatives, seven samples constructed from purified CMV nucleocapsids in plasma (2.0,6.0 log10 copies/mL) and three clinical plasma samples. Interlaboratory variation was observed in both actual (range, 2.0,4.0 log10 copies/mL) and self-reported lower limits of detection (range, 1.0,4.0 log10 copies/mL). Variation observed in reported results for individual samples ranged from 2.0 log10 (minimum) to 4.3 log10 (maximum). Variation was greatest at low VLs. Assuming ± 0.5 log10 relative to the expected result represents an acceptable result, 57.6% of results fell within this range. Use of commercially available reagents and procedures was associated with less variability compared with laboratory-developed assays. Interlaboratory variability on replicate samples was significantly greater than intralaboratory variability (p < 0.0001). The significant interlaboratory variability in CMV VL observed may be impacting patient care and limiting interinstitutional comparisons. The creation of an international reference standard for CMV VL assay calibration would be an important step in quality improvement of this laboratory tool. [source] Fast Volume Rendering and Data Classification Using Multiresolution in Min-Max OctreesCOMPUTER GRAPHICS FORUM, Issue 3 2000Feng Dong Large-sized volume datasets have recently become commonplace and users are now demanding that volume-rendering techniques to visualise such data provide acceptable results on relatively modest computing platforms. The widespread use of the Internet for the transmission and/or rendering of volume data is also exerting increasing demands on software providers. Multiresolution can address these issues in an elegant way. One of the fastest volume-rendering alrogithms is that proposed by Lacroute & Levoy 1 , which is based on shear-warp factorisation and min-max octrees (MMOs). Unfortunately, since an MMO captures only a single resolution of a volume dataset, this method is unsuitable for rendering datasets in a multiresolution form. This paper adapts the above algorithm to multiresolution volume rendering to enable near-real-time interaction to take place on a standard PC. It also permits the user to modify classification functions and/or resolution during rendering with no significant loss of rendering speed. A newly-developed data structure based on the MMO is employed, the multiresolution min-max octree, M 3 O, which captures the spatial coherence for datasets at all resolutions. Speed is enhanced by the use of multiresolution opacity transfer functions for rapidly determining and discarding transparent dataset regions. Some experimental results on sample volume datasets are presented. [source] A simple method using climatic variables to estimate canopy temperature, sensible and latent heat fluxes in a winter wheat field on the North China PlainHYDROLOGICAL PROCESSES, Issue 5 2009L. Li Abstract Estimation of evapotranspiration from a crop field is of great importance for detecting crop water status and proper irrigation scheduling. The Penman,Monteith equation is widely viewed as the best method to estimate evapotranspiration but it requires canopy resistance, which is very difficult to determine in practice. This paper presents a simple method simplified from the Penman,Monteith equation for estimating canopy temperature (Tc). The proposed method is a biophysically-sound extended version of that proposed by Todorovic. The estimated canopy temperature is used to calculate sensible heat flux, and then latent heat flux is calculated as the residual of the surface energy balance. An eddy covariance (EC) system and an infrared thermometer (IRT) were installed in an irrigated winter wheat field on the North China Plain in 2004 and 2005, to measure Tc, and sensible and latent heat fluxes were used to test the modified Todorovic model (MTD). The results indicate that the original Todorovic model (TD) severely underestimates Tc and sensible heat flux, and hence severely overestimates the latent heat flux. However, the MTD model has good capability for estimating Tc, and gives acceptable results for latent heat flux at both half-hourly and daily scales. The MTD model results also agreed well with the evapotranspiration calculated from the measured Tc. Copyright © 2008 John Wiley & Sons, Ltd. [source] Assessing the impact of the hydraulic properties of a crusted soil on overland flow modelling at the field scaleHYDROLOGICAL PROCESSES, Issue 8 2006Nanée Chahinian Abstract Soil surface crusts are widely reported to favour Hortonian runoff, but are not explicitly represented in most rainfall-runoff models. The aim of this paper is to assess the impact of soil surface crusts on infiltration and runoff modelling at two spatial scales, i.e. the local scale and the plot scale. At the local scale, two separate single ring infiltration experiments are undertaken. The first is performed on the undisturbed soil, whereas the second is done after removal of the soil surface crust. The HYDRUS 2D two-dimensional vertical infiltration model is then used in an inverse modelling approach, first to estimate the soil hydraulic properties of the crust and the subsoil, and then the effective hydraulic properties of the soil represented as a single uniform layer. The results show that the crust hydraulic conductivity is 10 times lower than that of the subsoil, thus illustrating the limiting role the crust has on infiltration. Moving up to the plot scale, a rainfall-runoff model coupling the Richards equation to a transfer function is used to simulate Hortonian overland flow hydrographs. The previously calculated hydraulic properties are used, and a comparison is undertaken between a single-layer and a double-layer representation of the crusted soil. The results of the rainfall-runoff model show that the soil hydraulic properties calculated at the local scale give acceptable results when used to model runoff at the plot scale directly, without any numerical calibration. Also, at the plot scale, no clear improvement of the results can be seen when using a double-layer representation of the soil in comparison with a single homogeneous layer. This is due to the hydrological characteristics of Hortonian runoff, which is triggered by a rainfall intensity exceeding the saturated hydraulic conductivity of the soil surface. Consequently, the rainfall-runoff model is more sensitive to rainfall than to the subsoil's hydrodynamic properties. Therefore, the use of a double-layer soil model to represent runoff on a crusted soil does not seem necessary, as the increase of precision in the soil discretization is not justified by a better performance of the model. Copyright © 2005 John Wiley & Sons, Ltd. [source] Solvent effects on kinetics of an aromatic nucleophilic substitution reaction in mixtures of an ionic liquid with molecular solvents and prediction using artificial neural networksINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 3 2009Aziz Habibi-Yangjeh Kinetics of the reaction between 1-chloro-2,4-dinitrobenzene and aniline was studied in mixtures of 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) with methanol, chloroform, and dimethylsulfoxide at 25°C. Single-parameter correlations of log kA versus normalized polarity parameter (ENT), hydrogen-bond acceptor basicity (,), hydrogen-bond donor acidity (,), and dipolarity/polarizability (,*) of media do not give acceptable results. Multiparameter linear regression (MLR) of log kA versus the solvatochromic parameters demonstrates that the reaction rate constant increases with ENT, ,*, and , and decreases with , parameter. To predict accurately solvent effects on the rate constant, optimized artificial neural network with three inputs (including ,, ,*, and , parameters) was applied for prediction of the log kA values in the prediction set. It was found that properly selected and trained neural network could fairly represent the dependence of the reaction rate constant on solvatochromic parameters. Mean percent deviation of 5.023 for the prediction set by the MLR model should be compared with the value of 0.343 by the artificial neural network model. These improvements are due to the fact that the reaction rate constant shows nonlinear correlations with the solvatochromic parameters. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 153,159, 2009 [source] An analytical and experimental analysis of a very fast thermal transientINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2001C. Aprea Abstract According to some international standards, some products, developed for use under heavy thermal conditions, have to be tested by subjecting them for a short time to a particular heating and cooling thermal stress to allow them an acceptable future operative life. It is possible to obtain these fast thermal gradients in confined environments, called climatic chambers where the air is heated by an electrical resistance and is cooled with a finned evaporator which is linked to a vapour compression system subjected to a particular control system of the refrigerating power. In particular, in this paper the air and object tested thermal transients are studied from an analytical and experimental point of view. The study of the mathematical model is realized assuming simplified hypotheses about the air, the object and the air cooled evaporator temperature. The most complex circumstances are related to a very fast temperature decrease because under this working condition the mathematical model is characterized by a nonlinear differential system. The nonlinear term is represented by the refrigerating power that varies in a definite range with the evaporator temperature according to a sinusoid trend. For this power a suitable analytical expression, derived by the control system performance and by the compressor characteristic, has been found. The analytical,experimental comparison during a cooling thermal stress of typical products subjected to international standard tests as the electronic boards, has been carried out showing acceptable results. The model presented is useful to foresee the climatic chamber performances in the presence of a specific refrigerating power trend; this is the start-point for the design of the vapour compression plant and its control system. Copyright © 2001 John Wiley & Sons, Ltd. [source] Hypomineralized molars and incisors of unknown origin: treatment outcome at age 18 yearsINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2005I. MEJÀRE Summary. Objective., To assess the outcome of treatment of hypomineralized molars and incisors of unknown aetiology (MIH) in 18-year-olds. Design., A follow-up study including clinical examination, panoramic radiography and intraoral photos. Sample and method., Seventy-six individuals treated at the Eastman Dental Institute in Stockholm during 1978,2001 with the diagnosis MIH. Severity of enamel defects in molars and incisors, prevalence and distribution of extracted molars, type, quality and median duration of restorations, periradicular condition of affected molars, dental occlusion and space closure in cases of extraction, as well as the individual's satisfaction with the treatment, were assessed. Results., Severe defects with enamel surface breakdown in all four molars occurred in 42% of the individuals and 29% had at least one incisor with yellow/brown opacity in the enamel. At follow up, 42% of the individuals had at least one molar extracted; 18% had all four molars extracted. The median duration of the molar restorations (n = 153) was 5 years. Of the individuals with restored molars, 48% had at least one unacceptable restoration. Periradicular pathology was observed in three molars. The sagittal relations did not differ between individuals with and without extraction of molars. Space closure was acceptable in 87% of the individuals with extracted molars. Eighty percent were satisfied with the treatment. Conclusions., Extraction of molars with severe enamel defects gave good or acceptable results in a majority of the patients while conservative restorative treatment resulted in a need for additional treatment in approximately half of the patients. [source] The De-Escalating Aggressive Behaviour Scale: development and psychometric testingJOURNAL OF ADVANCED NURSING, Issue 9 2009Johannes Nau Abstract Title.,The De-Escalating Aggressive Behaviour Scale: development and psychometric testing. Aim., This paper is a report of a study to develop and test the psychometric properties of a scale measuring nursing students' performance in de-escalation of aggressive behaviour. Background., Successful training should lead not merely to more knowledge and amended attitudes but also to improved performance. However, the quality of de-escalation performance is difficult to assess. Method., Based on a qualitative investigation, seven topics pertaining to de-escalating behaviour were identified and the wording of items tested. The properties of the items and the scale were investigated quantitatively. A total of 1748 performance evaluations by students (rater group 1) from a skills laboratory were used to check distribution and conduct a factor analysis. Likewise, 456 completed evaluations by de-escalation experts (rater group 2) of videotaped performances at pre- and posttest were used to investigate internal consistency, interrater reliability, test,retest reliability, effect size and factor structure. Data were collected in 2007,2008 in German. Findings., Factor analysis showed a unidimensional 7-item scale with factor loadings ranging from 0·55 to 0·81 (rater group 1) and 0·48 to 0·88 (rater group 2). Cronbach's alphas of 0·87 and 0·88 indicated good internal consistency irrespective of rater group. A Pearson's r of 0·80 confirmed acceptable test,retest reliability, and interrater reliability Intraclass Correlation 3 ranging from 0·77 to 0·93 also showed acceptable results. The effect size r of 0·53 plus Cohen's d of 1·25 indicates the capacity of the scale to detect changes in performance. Conclusion., Further research is needed to test the English version of the scale and its validity. [source] Lignin-based polycondensation resins for wood adhesivesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2007N.-E. El Mansouri Abstract Lignin-based wood adhesives are obtained that satisfy the requirements of relevant international standards for the manufacture of exterior-grade wood particleboard. Formulations based on low molecular mass lignin and presenting an increase in the relative proportion of reactive points yield better results than the higher molecular mass lignin used in the past. These lignins allow a higher proportion of hydroxymethylation during preparation of methylolated lignins. These lignin-based adhesives also yield acceptable results at particleboard pressing times that are sufficiently low to be of industrial significance. Lignin-based wood adhesives, in which a nonvolatile nontoxic aldehyde (glyoxal) is substituted for formaldehyde in their preparation, are prepared and tested for application to wood panels such as particleboard. The adhesives yield good internal bond strength results for the panels, which are good enough to comfortably pass relevant international standard specifications for exterior-grade panels. The adhesives also show sufficient reactivity to yield panels in press times comparable to that of formaldehyde-based commercial adhesives. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1690,1699, 2007 [source] IMMEDIATE LOADING OF IMPLANTS IN THE ESTHETIC ZONEJOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2005Saj Jivraj DDS The predictability of dental implants using the traditional Branemark protocol has been well documented. Since its inception, this protocol has been progressively challenged to decrease treatment time, minimize the number of surgical procedures, and maximize esthetic outcomes. Today, in specific clinical situations, implants may be placed and immediately loaded with provisional restorations. Immediate loading in the edentulous mandible has been well documented. There are also good data to show that immediate loading of the edentulous maxilla is also feasible if bone quality is suitable. The focus now has shifted toward immediate loading of implants placed in the esthetic zone. Clinicians have recognized that the challenge of providing anterior tooth replacements is in preserving the hard and soft tissue components that exist around natural teeth. The advantages of immediate restoration are obvious; however, the application of immediate or early load may pose an increased risk of implant failure in single-tooth situations. The prerequisites for achieving and maintaining acceptable results are not fully known. This review examines some of the literature concerning the reliability of early or immediate loading of implants placed in the esthetic zone. [source] Feasibility of k-t BLAST technique for measuring "seven-dimensional" fluid flowJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 2 2006Ian Marshall PhD Abstract Purpose To investigate the feasibility of rapid MR measurement of "seven-dimensional" (three velocity components, three dimensions, and time) fluid flow using the k-t Broad-use Linear Acquisition Speed-Up Technique (BLAST). Materials and Methods Complete k -space data were acquired for pulsatile fluid flow in a model of a stenosed carotid bifurcation. The data was subsampled to simulate "training" and "accelerated acquisition" data for reconstruction using k-t BLAST. Results Flow waveforms estimated from k-t BLAST reconstructions were in good agreement with those measured from the full data set for overall speedup factors up to approximately four times when slice-by-slice undersampling in ky was used. Accuracy was better than 25 mm/second or 7% (root-mean-square error) for individual time frames under these conditions. Flow patterns in the plane of symmetry, near the bifurcation, and in the stenosis were also in good agreement with those reconstructed from the full data set. Improved performance was obtained from undersampling in both ky and kz, when acceleration factors up to 12 times gave acceptable results. Conclusion The k-t BLAST technique can be applied to flow quantification, and may make feasible the acquisition of time-resolved blood flow from extended arterial regions within acceptable examination times. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] On-line solid-phase extraction with a monolithic weak cation-exchange column and simultaneous screening of ,1-adrenergic receptor antagonists in human plasmaJOURNAL OF SEPARATION SCIENCE, JSS, Issue 17 2007Xiaoyi Wei Abstract An on-line SPE,HPLC method, using a monolithic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly(GMA-EDMA)) based weak cation-exchange (WCX) column, was developed for simultaneous determination of ,1-adrenergic receptor antagonists in human plasma. The monolithic WCX column was prepared by an in-situ polymerization protocol and modified stepwise with ethylenediamine and chloroacetic acid. On connecting this column to an injection valve, an on-line SPE protocol could be established for removal of matrices (mainly proteins and lipids) and preconcentration of four ,1-adrenergic receptor antagonists in human plasma. This method was validated and then used for determination of terazosin, alfuzosin, prazosin, and doxazosin in clinical plasma samples. For all analytes, each calibration curve was found to be linear over a range of 0.005,5 ,g/mL (R >0.997), and the limit of detection for each analyte was 0.5 ng/mL. Recovery (> 80%) and precision (RSD <15%) for inter- and intra-day assay were tested at three concentration levels of each analyte and showed acceptable results for quantitative assay. Real samples from hypertensive patients were monitored and results were in agreement with those of the conventional liquid,liquid extraction-HPLC method. Furthermore, due to its good permeability and biocompatibility, the monolithic WCX sorbent could be reused more than 300 times. The proposed method was especially appropriate for multi-analyte monitoring in plasma samples. [source] Rapid techniques for the extraction of vitamin E isomers from Amaranthus caudatus seeds: ultrasonic and supercritical fluid extractionPHYTOCHEMICAL ANALYSIS, Issue 5 2002Renato Bruni Abstract Supercritical fluid extraction (SFE) of seeds of Amaranthus caudatus (Amaranthaceae) and the use of ultrasound as a co-adjuvant in the extraction process were compared with methods traditionally used in the extraction of tocopherols and fatty acids. The use of readily available ultrasound equipment as an adjunct to the classical methods employed for the extraction of tocols provided qualitatively acceptable results more rapidly and more economically. SFE gave quantitatively better yields in shorter times, with solvent-free extracts obtained under conditions that minimised the degradation of thermolabile components. No significant variations were observed in the profile of the fatty acids extracted from amaranth oil by SFE or other methods, thus confirming the qualitative comparability of the faster supercritical extraction with the more time-consuming classical techniques even when processed with the aid of ultrasound. Copyright © 2002 John Wiley & Sons, Ltd. [source] Analysis of estrogenic contaminants in river water using liquid chromatography coupled to ion trap based mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 14 2002Tom Benijts A precise and reliable method, using liquid chromatography combined with ion trap based mass spectrometry, for the determination of three endogenous estrogens, namely, estrone, estradiol, and estriol, and two synthetic estrogens, ethinyl estradiol and diethylstilbestrol, in environmental water samples was developed. Optimization of the parameter settings of the ion source and mass analyzer as well as evaluation of solvent composition were carried out by continuous introduction of standards through a syringe pump. In negative ion mode the electrospray ionization source gave acceptable results. The optimum solvent used consisted of water/acetonitrile, with no volatile bases or buffers added. A simple, off-line, manual solid-phase extraction method was developed for sample preparation of environmental water samples. Recoveries were over 86% for all compounds. The method was validated and found to be linear, selective, and robust. For analysis of a 50-mL sample, the limit of detection (LOD) ranged from 3.2 to 10.6,ng/L for all compounds, and the limit of quantitation (LOQ) from 10.6 to 35.0,ng/L. Within-day (n,=,5) and total (n,=,5) reproducibility were investigated at three different concentration levels and ranged from 6.2 to 9.5% and 9.4 to 12.1%, respectively. Finally, the method was applied to real-world samples. Copyright © 2002 John Wiley & Sons, Ltd. [source] CFD simulation of gas,solid bubbling fluidized bed: A new method for adjusting drag lawTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2009Farshid Vejahati Abstract In computational fluid dynamics modelling of gas,solid two phase flow, drag force is one of the dominant mechanisms for interphase momentum transfer. Despite the profusion of drag models, none of the available drag functions gives accurate results in their own original form. In this work the drag correlations of Syamlal and O'Brien (Syamlal and O'Brien, Int. J. Multiphase Flow. 1988; 14(4):473,481), Gidaspow (Gidaspow, Appl. Mech. Rev. 1986; 39:1,23), Wen and Yu (Wen and Yu, Chem. Eng. Prog. Symp. Ser. 1966; 62(2):100,111), Arastoopour et al. (Arastoopour et al., Powder Technol. 1990; 62(2): 163,170), Gibilaro et al. (Gibilaro et al., Chem. Eng. Sci. 1985; 40:1817,1823), Di Felice (Di Felice, Int. J. Multiphase Flow. 1994; 20(1):153,159), Zhang-Reese (Zhang and Reese, Chem. Eng. Sci. 2003; 58(8):1641,1644) and Hill et al. (Hill et al., J. Fluid Mech. 2001; 448:243,278) are reviewed using a multi-fluid model of FLUENT V6.3.26 (FLUENT, 2007. Fluent 6.3 User's Guide, 23.5 Eulerian Model, Fluent, Inc.) software with the resulting hydrodynamics parameters being compared with experimental data. The main contribution of this work is to propose an easy to implement and efficient method for adjustment of Di Felice drag law which is more efficient compared to the one proposed by Syamlal-O'Brien. The new method adopted in this work showed a quantitative improvement compared to the adjusted drag model of Syamlal-O'Brien. Prediction of bed expansion and pressure drop showed excellent agreement with results of experiments conducted in a Plexiglas fluidized bed. A mesh size sensitivity analysis with varied interval spacing showed that mesh interval spacing with 18 times the particle diameter and using higher order discretization methods produces acceptable results. Dans la modélisation par la dynamique des fluides par ordinateur de l'écoulement diphasique gaz-solide, la force de traînée est l'un des mécanismes dominants dans le transfert de quantité de mouvement interphase. Malgré la profusion des modèles de traînée, aucune des fonctions de traînée disponibles ne donnent de résultats précis dans leur forme originale. Dans cet article, les corrélations de traînée de Syamlal and O'Brien (Syamlal and O'Brien, Int. J. Multiphase Flow. 1988; 14(4):473,481), Gidaspow (Gidaspow, Appl. Mech. Rev. 1986; 39:1,23), Wen and Yu (Wen and Yu, Chem. Eng. Prog. Symp. Ser. 1966; 62(2):100,111), Arastoopour et al. (Arastoopour et al., Powder Technol. 1990; 62(2):163,170), Gibilaro et al. (Gibilaro et al., Chem. Eng. Sci. 1985; 40:1817,1823), Di Felice (Di Felice, Int. J. Multiphase Flow. 1994; 20(1):153,159), Zhang-Reese (Zhang and Reese, Chem. Eng. Sci. 2003; 58(8):1641,1644) et Hill et al. (Hill et al., J. Fluid Mech. 2001; 448:243,278) sont examinées à l'aide du modèle multi-fluides du logiciel FLUENT V6.3.26 (FLUENT, 2007. Fluent 6.3 User's Guide, 23.5 Eulerian Model, Fluent, Inc.), les paramètres hydrodynamiques résultants étant comparés aux données expérimentales. La principale contribution de ce travail est de proposer une méthode efficace et facile à mettre en ,uvre pour l'ajustement de la loi de traînée de Di Felice qui est plus efficace comparativement à celle proposée par Syamlal-O'Brien. La nouvelle méthode adoptée dans ce travail montre une amélioration quantitative par rapport au modèle de traînée ajusté de Syamlal-O'Brien. La prédiction de l'expansion de lit et de la perte de charge montre un excellent accord avec les résultats des expériences menées dans un lit fluidisé en plexiglass. Une analyse de sensibilité de la taille des mailles avec des mailles de taille variable variés montre qu'une taille de maille égale à 18 fois le diamètre des particules et l'utilisation de méthodes de discrétisation d'ordre supérieur donnent des résultats acceptables. [source] How safe is open abdominal aortic aneurysm surgery for octogenarians in New Zealand?ANZ JOURNAL OF SURGERY, Issue 5 2009Ian A. Thomson Abstract Background:, Abdominal aortic aneurysm (AAA) is an important cause of mortality for the aged, a group that has been denied surgery in the past for fear of peri-operative mortality. Is this attitude still justified? Methods:, Analysis of prospectively gathered data from a vascular database. Results:, 10.9% of all open AAA operations were in patients older than 79 years with an 8% mortality cate compared to 3% for younger patients. For fit elderly patients with ASA scores less than 3, mortality was just under 4%. Renal failure and wound dehiscence were more common in the elderly. Conclusion:, When endovascular repair is not possible in a fit elderly patient, open surgery can be performed with acceptable results. [source] The diffusion of marketing science in the practitioners' community: opening the black boxAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 4-5 2005Albert C. Bemmaor Abstract This editorial discusses an illustration of the potential hindrances to the diffusion of modern methodologies in the practitioners' (i.e. the buyers of research, not the consultants) community. Taking the example of classical regression analysis based on store-level scanner data, the authors discuss the potential limitations of the classical regression model, with the example of the occurrence of ,wrong' signs and of coefficients with unexpected magnitudes. In an interview with one of the authors, a (randomly picked) Senior Marketing Research Manager at a leading firm of packaged goods reports his/her experience with econometric models. To him/her, econometric models are presented as a ,black box' (his/her written words). In his/her experience, they provided results that were ,quite good' in a ,much focused' context only. There were experimental data obtained with a Latin square design and the analysis included a single brand with only four stock-keeping units (SKUs). The company ,dropped' the more ,ambitious' studies, which analysed the effect of the retail promotions run by all the actors in a market because of a lack of predictive accuracy (his/her written words are in quotes). The authors suggest that Bayesian methodology can help open the black box and obtain more acceptable results than those obtained at present. Copyright © 2005 John Wiley & Sons, Ltd. [source] Performance Decline and Turnaround in Public Organizations: A Theoretical and Empirical Analysis,BRITISH JOURNAL OF MANAGEMENT, Issue 3 2005Pauline Jas Public sector performance is currently a significant issue for management practice and policy, and especially the turnaround of those organizations delivering less than acceptable results. Theories of organizational failure and turnaround derive largely from the business sector and require adaptation to the public service. The performance of public organizations is more complex to measure, is related to institutional norms, and the idea of ,failure' is problematic. Empirical findings from a real-time, longitudinal study of poorly performing English local authorities are used to develop an initial theory of performance failure and turnaround suited to public organizations. The paper argues that the typical performance of public organizations over time is cyclical. Where cognition and leadership capability are absent, organizations fail to self-initiate turnaround. In this situation authoritative external intervention is necessary. The strategies applied are principally concerned with building a leadership capability that engages senior politicians and managers in order to overcome inertia and collective action problems. The theory is presented in the form of seven propositions that provide a basis for further research across the public sector. [source] Comparison between jaw bone augmentation by means of a stiff occlusive titanium membrane or an autologous hip graft: a retrospective clinical assessmentCLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2006Liene Molly Abstract Objectives: Patients in need of bone augmentation procedures can be treated with a traditional hip graft or by neogenesis under a stiff occlusive titanium membrane, custom-fit on the basis of CT-scan data. Material and methods: Eighteen patients treated by means of a hip graft (H) were compared with 11 patients using a full titanium membrane (M) for the rehabilitation of upper jaws. In the H group, 17 patients (62 implants) in the anterior region (Ha) and 14 patients (23 implants) in the posterior region (Hp) were included. In the M group, nine patients (30 implants) in the anterior region (Ma) and seven patients (16 implants) in the posterior region (Mp) were included. Results: In group Ha, the CFR was 13.3% after 14 years compared with group Ma where the CFR was 17.4% after 9 years. In group Hp, the CFR was 22.8% after 16 years compared with group Mp where the CFR was 23.4% after 6 years. The marginal bone loss for group Ha after 20 years was 2.7 mm, for group Ma it was not even 1 mm after 9 years; for group Hp, it was 2.5 mm after 15 years compared with less than 1 mm after 3 years in group Mp. Conclusions: The success rate of alveolar ridge augmentation therapy is lower than in a classical approach. These augmentation procedures, however, show acceptable results. The titanium membrane augmentation leads to less marginal bone loss probably because neo-formed bone has a better chance to adapt its mineralization to occlusal forces encountered. This technique could offer improvement if membrane exposure can be avoided. [source] | |||||||||||||||||||