Empty nose syndrome : case report

Empty Nose Syndrome (ENS) is a term first introduced by Kern and Moore which is used to describe a rare spectrum of various symptoms suffered by patients who had had previous radical turbinate surgery with a CT scan appearance of the paranasal sinuses after gross tissue loss. The most common symptom is so- called ‘‘paradoxical’’ nasal obstruction, reported by the patient despite objectively permeable cavities on clinical examination with no obstacle found on imaging or rhinomanometry and acoustic rhinometry.1 In most cases, the inferior turbinate (IT) has been resected radically even though middle turbinate (MT) resection has also been implicated.2 Incidence is unknown, as there have been no specific studies published. The estimated rate of ENS following inferior turbinate resection is 20%, which induces simple dry nose.peer-reviewe

A Positive and Entropy-Satisfying Finite Volume Scheme for the Baer-Nunziato Model

We present a relaxation scheme for approximating the entropy dissipating weak solutions of the Baer-Nunziato two-phase flow model. This relaxation scheme is straightforwardly obtained as an extension of the relaxation scheme designed in [16] for the isentropic Baer-Nunziato model and consequently inherits its main properties. To our knowledge, this is the only existing scheme for which the approximated phase fractions, phase densities and phase internal energies are proven to remain positive without any restrictive condition other than a classical fully computable CFL condition. For ideal gas and stiffened gas equations of state, real values of the phasic speeds of sound are also proven to be maintained by the numerical scheme. It is also the only scheme for which a discrete entropy inequality is proven, under a CFL condition derived from the natural sub-characteristic condition associated with the relaxation approximation. This last property, which ensures the non-linear stability of the numerical method, is satisfied for any admissible equation of state. We provide a numerical study for the convergence of the approximate solutions towards some exact Riemann solutions. The numerical simulations show that the relaxation scheme compares well with two of the most popular existing schemes available for the Baer-Nunziato model, namely Schwendeman-Wahle-Kapila's Godunov-type scheme [39] and Toro-Tokareva's HLLC scheme [42]. The relaxation scheme also shows a higher precision and a lower computational cost (for comparable accuracy) than a standard numerical scheme used in the nuclear industry, namely Rusanov's scheme. Finally, we assess the good behavior of the scheme when approximating vanishing phase solutions

ONLINE APPROXIMATION ASSISTED MULTIOBJECTIVE OPTIMIZATION WITH HEAT EXCHANGER DESIGN APPLICATIONS

Computer simulations can be intensive as is the case in Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA). The computational cost can become prohibitive when using these simulations with multiobjective design optimization. One way to address this issue is to replace a computationally intensive simulation by an approximation which allows for a quick evaluation of a large number of design alternatives as needed by an optimizer. This dissertation proposes an approach for multiobjective design optimization when combined with computationally expensive simulations for heat exchanger design problems. The research is performed along four research directions. These are: (1) a new Online Approximation Assisted Multiobjective Optimization (OAAMO) approach with a focus on the expected optimum region, (2) a new approximation assisted multiobjective optimization with global and local metamodeling that always produces feasible solutions, (3) a framework that integrates OAAMO with multiscale simulations (OAAMOMS) for design of heat exchangers at the segment and heat exchanger levels, and (4) applications of OAAMO combined with CFD for shape design of a header for a new generation of heat exchangers using Non-Uniform Rational B-Splines (NURBS). The approaches developed in this thesis are also applied to optimize a coldplate used in electronic cooling devices and different types of plate heat exchangers. In addition many numerical test problems are solved by the proposed methods. The results of these studies show that the proposed online approximation assisted multiobjective optimization is an efficient approach that can be used to predict optimum solutions for a wide class of problems including heat exchanger design problems while reducing significantly the computational cost when compared with existing methods

E-training Implementation in Saudi Arabia: An Exploratory Study in Private Sector in Jeddah

This paper explores the justification for implementing, the benefits and barriers of e-training from training managers working in private sector in Jeddah. The questionnaire was used to gather the data from training managers. Total 150 questionnaires were distributed, out of that 63 questionnaires were used in the analysis. The results showed that the implantation of e-training is growing rapidly in private sector in Jeddah. In addition the results demonstrate that the main drivers for e-training investment were linked to improved delivery and flexibility, increased access, reduced costs, and better administration for implementing training from managers’ perspective. However, the most important challenges identified by mangers were related to absence of a professional online training center in Arabic and the lack of expertise in E-training inside the company. Based on the results, a number of recommendations and future research areas were discussed. Keywords: E-training, E-learning, Implementation, Corporate training, Employee training

Integrated Land Use Change Analysis For Soil Ersion Study In Ulu Kinta Catchment [S623. B354 2006 f rb].

Ulu Kinta catchment has experienced rapid changes in land use and land cover from 1991 to 2004. These changes have resulted in increased upland erosion and higher concentrations of suspended sediment within the catchment. The goal of this research was to investigate the application of integrated satellite remote sensing and Geographic Information Systems (GIS) techniques to assess land cover changes and the estimation of soil erosion in the water catchment. Kawasan tadahan Ulu Kinta telah mengalami perubahan yang ketara di dalam penggunaan tanah dan liputan tanah dari tahun 1991 hingga 2004. Perubahan ini telah meningkatkan hakisan tanah dan meninggikan kepekatan bahan asing yang terampai di dalam kawasan tadahan. Tujuan kajian ini adalah untuk mengkaji penggunaan bersama teknik penderiaan jauh satelit dan Sistem Maklumat Geografi (GIS) untuk menilai perubahan litupan bumi dan anggaran penghakisan tanah untuk kawasan tadahan air

Profiling of propolis samples from UK, Indonesia and sub-Saharan Africa and isolation of some pure components

Propolis is a resinous material collected by bees as part of the defensive system of the bee hive. It has a wide range of biological activities including anti-protozoal and [sic] and microbial activity. Samples of propolis from different parts of the UK, Africa and Indonesia were extracted and profiled by liquid chromatography-high resolution mass spectrometry. The data were aligned and features were extracted into 0.02 amu windows. In order to establish a platform for comparison of the samples the top features by peak intensity, after excluding abundant dimer peaks, were further characterized by MS2. Putative identities were deduced from accurate masses which were within 3 ppm deviations from the exact mass of the proposed elemental compositions. For the UK propolis samples, over 90% of the peaks could be assigned identities with some level of confidence. The compounds identified fell into the major categories: flavonoid esters and possibly some ethers, phenyl propanoid esters, glycerol esters, flavonoid glycosides and hydroxylated fatty acids. Pinobanksin was the most abundant compound in the samples. The flavonoids pinocembrin, pinobanksin, galangin and chrysin showed a relatively low degree of variation across the nine samples whereas flavonoid esters and glycerol esters were more variable in their response across the nine samples. The propolis samples from hives in three different areas of Scotland yielded hundreds of components, many of which were not identified. In the Aberdeenshire samples principal components analysis (PCA) followed by hierarchical cluster analysis (HCA) grouped nine samples into six groups according to the abundance of their components. The Aberdeenshire samples were abundant in glycerol esters. Five samples from Fort William could be divided into four groups. These samples had quite a different composition from the Aberdeenshire samples containing an abundance of compounds putatively identified as being sesquiterpene acids. Three samples from Dunblane were different again but had more similarity in composition to the Aberdeenshire samples than the Fort William samples. The propolis sample from Indonesia yielded predominantly phenolic compounds. Although standards were not available to determine the identities and actual amounts of the compounds in the samples, preparative chromatographic separation enabled the identification of some of the compounds by NMR spectroscopy (1D and 2D) and mass spectra as pinobanksin, apigenin, lupeol, gallic acid and quercetin. The role of propolis in warding off infections in the bee hive which is yet established was addressed in this study and the approach provides a potential method for correlating hive health with the composition of the propolis gathered by the bees. Thus this study also confirms local and regional variations in propolis composition over a relatively small areas and over wide geographical regions.Propolis is a resinous material collected by bees as part of the defensive system of the bee hive. It has a wide range of biological activities including anti-protozoal and [sic] and microbial activity. Samples of propolis from different parts of the UK, Africa and Indonesia were extracted and profiled by liquid chromatography-high resolution mass spectrometry. The data were aligned and features were extracted into 0.02 amu windows. In order to establish a platform for comparison of the samples the top features by peak intensity, after excluding abundant dimer peaks, were further characterized by MS2. Putative identities were deduced from accurate masses which were within 3 ppm deviations from the exact mass of the proposed elemental compositions. For the UK propolis samples, over 90% of the peaks could be assigned identities with some level of confidence. The compounds identified fell into the major categories: flavonoid esters and possibly some ethers, phenyl propanoid esters, glycerol esters, flavonoid glycosides and hydroxylated fatty acids. Pinobanksin was the most abundant compound in the samples. The flavonoids pinocembrin, pinobanksin, galangin and chrysin showed a relatively low degree of variation across the nine samples whereas flavonoid esters and glycerol esters were more variable in their response across the nine samples. The propolis samples from hives in three different areas of Scotland yielded hundreds of components, many of which were not identified. In the Aberdeenshire samples principal components analysis (PCA) followed by hierarchical cluster analysis (HCA) grouped nine samples into six groups according to the abundance of their components. The Aberdeenshire samples were abundant in glycerol esters. Five samples from Fort William could be divided into four groups. These samples had quite a different composition from the Aberdeenshire samples containing an abundance of compounds putatively identified as being sesquiterpene acids. Three samples from Dunblane were different again but had more similarity in composition to the Aberdeenshire samples than the Fort William samples. The propolis sample from Indonesia yielded predominantly phenolic compounds. Although standards were not available to determine the identities and actual amounts of the compounds in the samples, preparative chromatographic separation enabled the identification of some of the compounds by NMR spectroscopy (1D and 2D) and mass spectra as pinobanksin, apigenin, lupeol, gallic acid and quercetin. The role of propolis in warding off infections in the bee hive which is yet established was addressed in this study and the approach provides a potential method for correlating hive health with the composition of the propolis gathered by the bees. Thus this study also confirms local and regional variations in propolis composition over a relatively small areas and over wide geographical regions

Pfannenstiel incision for intact specimen extraction in laparoscopic transperitoneal radical nephrectomy: a longitudinal prospective outcome study

OBJECTIVES: To evaluate the intra- and postoperative outcomes of patients undergoing laparoscopic radical nephrectomy with intact specimen extraction through a Pfannenstiel transverse suprapubic incision. METHODS: Prospective follow-up of 26 laparoscopic transperitoneal radical nephrectomies for suspected renal tumors in which the kidneys were extracted via a Pfannenstiel lower abdominal transverse incision. RESULTS: The mean operating time was 152.3 (80-255) minutes, and the mean blood loss was 90 (20-300) ml. The mean extraction time was 20.4 (12-35) minutes. The mean weight of the removed specimen was 631.5 (190-1505) grams, and the mean longest diameter of the extracted specimen was 17.4 (9-25) cm. The mean extraction incision size was 10.7 (7-16) cm. No open surgical conversions were necessary. Pain control was excellent, with minimal intravenous morphine equivalent narcotic use by patients: 15.7 (0-31) mg in the recovery room, 33.8 (0-127) mg on the first postoperative day and 8.7 (0-60) mg in the first week after discharge. The patients experienced a short duration to full ambulation and normal dietary intake. Postoperative follow-up visits were recorded for at least six months. The patients reported a high cosmetic satisfaction rate of 97.7% (60-100). No late postoperative complications were observed related to the extraction site. CONCLUSIONS: The operative specimen can be extracted via a low transverse Pfannenstiel incision during radical laparoscopic nephrectomy. This incision ensures the extraction of large specimens while preserving the aesthetic and functional advantages of laparoscopy without increasing the cancer risk. The absence of muscle cutting maintains the integrity of the abdominal wall and elicits minimal pain. No postoperative incisional hernias or keloid formations were observed

Protection of Direct-Current Systems

The overwhelming advancement in power electronics converters throughout the past few decades is leading to an increasing interest in the integration of Direct-Current (DC) systems to the existing AC ones on the generation, Low Voltage DC (LVDC), Medium Voltage DC (MVDC), and High Voltage DC (HVDC) levels. The utilization of DC systems offer many benefits over their AC counterparts such as the significant reduction in power losses and costs as well as the minimization of reactive current component. Nevertheless, DC systems still face many challenges among which protection is the most salient. This dissertation investigates and addresses the protection challenges posed by DC faults’ behaviour in five DC systems. On the generation level, it explores the nature of various faults and partial shading conditions in utility-scale Photovoltaic (PV) arrays. The unique PV modules’ voltage behaviour during faults and partial shading conditions is scrutinized to identify distinctive characteristics. These voltage features are utilized to propose a new time-domain voltage-based protection scheme. The proposed scheme’s underlying concepts are analytically proved for generic PV modules, validated using detailed time-domain model of PV panels, and verified experimentally using polycrystalline-silicon panels. On the LVDC level, the dissertation examines the behaviour of low- and high-resistance faults. The analysis are founded upon a detailed time-domain simulation of a meshed LVDC microgrid. The failure of conventional protection methods in the presence of even small amounts of fault resistance are demonstrated. An effective method is proposed to detect such faults by using the resonance frequency generated from passive oscillators installed on the line terminals. The protection of MVDC microgrids is a major challenge as very high fault current magnitudes are attained within a couple of milliseconds. This dissertation reveals unique fault-launched Travelling wave (TW) waveform and polarity properties. These properties are exploited to propose an adequate time-domain TW-based protection scheme that detects, classifies, and locates DC faults in a timely manner. The impediments to reliable protection of hybrid AC/DC microgrids are twofold: (i) the very low AC fault current magnitudes in the AC-side due to the current control capability of inverter-based Distributed Generation (DG)s, and (ii) the very high DC fault current magnitudes attained within few milliseconds in the DC-side due to the uncontrollable discharge of the converters’ DC link capacitors. A unified discriminant function TW-based protection scheme is proposed for hybrid AC/DC microgrids to detect, classify, and locate both AC and DC faults. DC faults in HVDC grids can cause severe damage to the converter stations and large loss of infeed within few milliseconds. Ensuring selectivity and sensitivity of the protection system within a short time window is a major challenge. This dissertation analyze the frequency spectra of the TWs initiated by faults on HVDC grids. Using the spectral content and polarity of the current TWs, a novel frequency-domain TW-based scheme is proposed to detect and locate faults within the required timeframe