The effect of flow coefficient on the design of miniature centrifugal impeller

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.A systematic and simple design methodology of miniature centrifugal impeller is proposed. In the design of miniature centrifugal impeller, the flow coefficient ϕ1 plays a significant role. Theoretically, the geometric parameters, including inner radius, blade angles and blade height can be expressed as functions of the flow coefficient. Accordingly, the theoretical head and energy losses are also influenced by the flow coefficient. To investigate the effect of flow coefficient, a series of miniature impellers are designed for different flow coefficients, and CFD simulations are conducted. Both theoretical analysis and CFD simulations show similar trends. Initially, the pressure generated increases with increasing flow coefficient. Upon reaching a maximum, it will subsequently decrease with increasing flow coefficient. Hence, an optimal flow coefficient should be chosen to achieve the best performance. From the theoretical results, the maximum pressure generated occurs when the flow coefficient is approximately 2.8, while for CFD, it is approximately 1.3. The difference between the theoretical analysis and CFD simulation shows that the theoretical model should be further improved to enhance its accuracy

A regimen of systematic periodontal care after removal of impacted mandibular third molars manages periodontal pockets associated with the mandibular second molars

Aim: This randomized, single-blinded control trial investigated the local effects of periodontal care on the mandibular second molar delivered during and after impacted third molar surgical extraction. Method: Thirty subjects (50% male, 32.1 ± 7.8 years) out of 35 enrolled, with a mesio-angular impacted mandibular third molar, having probing pocket depth (PPD) > 5 mm at adjacent second molar distal, and crestal radio-lucency between the two teeth, completed the study. Oral hygiene instruction, scaling and caries stabilization were performed before surgery. Controls (n = 16) had their third molar extracted followed by standard socket debridement. Test group subjects (n = 14) received the same treatment, except that before wound closure the operator was informed of the group allocation and ultrasonic root debridement on the second molar was performed, followed by a three-visit plaque control programme. Results: Six months post-extraction, statistically significantly (p < 0.007) better plaque control and shallower probing depths were observed at test second molars' distal (%plaque = 21; PPD = 3.2 ± 1.2 mm) than at control second molars (%plaque = 88; PPD = 5.2 ± 0.7 mm). Conclusions: The periodontal interventions investigated prevented residual pockets on periodontally involved second molars 6 months after ipsilateral impacted mandibular third molar removal. Copyright © Blackwell Munksgaard 2005.postprin

Helicobacter pylori associated gastric intestinal metaplasia: Treatment and surveillance

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Self-tuning neurofuzzy control for nonlinear systems with offset

A self-tuning neurofuzzy controller with an ability to remove offsets is derived in this paper based on the self-tuning integrating controller derived for the local linear model. The training target for the proposed controllers is derived, and they can be trained by the simplified recursive least squares (RLS) method with a computing time that is linear instead of geometric in the number of weights in the network. Further, the simplified RLS method not only has the same convergence property as the RLS method, it also has a better ability in tracking varying parameters. The performance of the self-tuning neurofuzzy controller is illustrated by examples involving both linear and nonlinear systems.published_or_final_versio

New high-definition narrow band imaging versus conventional high-definition white light colonoscopy for detection of colorectal adenomas: a randomised controlled trial with tandem colonoscopy

This journal suppl. entitled: 19th Medical Research Conference; Department of Medicine, The University of Hong Kong, Queen Mary Hospital, Hong KongPoster PresentationINTRODUCTION: Adenoma detection is important in colonoscopy as polypectomy has been shown to reduce the subsequent incidence and mortality of colorectal cancer. Narrow band imaging (NBI), an image-enhanced imaging system of the endoscopy, is developed to improve the diagnostic performance of the endoscopy. We tested whether the new generation of NBI colonoscopy would improve detection of colorectal adenoma when compared with high-definition white light (HD-WL) in a randomised tandem colonoscopy study ...postprin

A hybrid algorithm for spatial and wavelet domain image restoration

The recent algorithm ForWaRD based on the two steps: (i) the Fourier domain deblurring and (ii) wavelet domain denoising, shows better restoration results than those using traditional image restoration methods. In this paper, we study other deblurring schemes in ForWaRD and demonstrate such two-step approach is effective for image restoration.published_or_final_versionS P I E Conference on Visual Communications and Image Processing 2005, Beijing, China, 12-15 July 2005. In Proceedings Of Spie - The International Society For Optical Engineering, 2005, v. 5960 n. 4, p. 59605V-1 - 59605V-

Dimension reduction based on canonical correlation

Dimension reduction is helpful and often necessary in exploring nonlinear or nonparametric regression structures with a large number of predictors. We consider using the canonical variables from the design space whose correlations with a spline basis in the response space are significant. The method can be viewed as a variant of sliced inverse regression (SIR) with simple slicing replaced by B-spline basis functions. The asymptotic distribution theory we develop extends to weakly dependent stationary sequences and enables us to consider asymptotic tests that are useful in determining the number of significant dimensions for modeling. We compare several tests for dimensionality and make specific recommendations for dimension selection based on our theoretical and empirical studies. These tests apply to any form of SIR. The methodology and some of the practical issues are illustrated through a tuition study of American colleges.published_or_final_versio

Population Factors Affecting Initial Diffusion Patterns of H1N1

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Effects of geographic scale on population factors in acute disease diffusion analysis

Objective To explore socio-demographic data of the population as proxies for risk factors in disease transmission modeling at different geographic scales. Methods Patient records of confirmed H1N1 influenza were analyzed at three geographic aggregation levels together with population census statistics. Results The study confirmed that four population factors were related in different degrees to disease incidence, but the results varied according to spatial resolution. The degree of association actually decreased when data of a higher spatial resolution were used. Conclusions We concluded that variables at suitable spatial resolution may be useful in improving the predictive powers of models for disease outbreaks.published_or_final_versio

Prevalence of antibiotic-resistant intestinal flora in patients undergoing transrectal ultrasonography-guided prostate biopsy (TRUS-Bx) and its implication for clinical practice: preliminary results

Oral (Free Paper) Session I - Prostate Cancer: Diagnosis to Treatment: OP.1-2香港泌尿外科學會OBJECTIVE: An important factor determining the choice of antibiotic for TRUS-Bx prophylaxis and treatment of post-biopsy infection is the prevalence of quinolone-resistant and ESBL-producing organisms in the rectum of patients undergoing this procedure. We aim to determine these prevalence values in patients undergoing TRUS-Bx and to study their correlation with the microbiological data of patients ...published_or_final_versionThe 17th Annual Scientific Meeting of the Hong Kong Urological Association, Hong Kong, 6 November 2011. In Program Book, 2011, p. 3