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Effects of the mass and volume shrinkage of ground chip and pellet particles on drying rates

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Particuology 2018年第3期16卷 1-9页

作者： Hamid Rezaei Shahab Sokhansaj c. Jim Lim Anthony lau Xiaotao Bi chemical and Biological Engineering Department University of British Columbia Vancouver BC V6T 1Z3 Canada Environmental Science Division Oak Ridge National Laboratory Oak Ridge TN 37381 USA

The effects of varying the mass and volume of ground chip and pellet particles on the particle drying rate were analyzed. Samples of whole pellets and chips were hammer milled using a 3.2 mm screen and the ground chip and pellet particles were found to have similar size distributions, although the pellet particles were denser and more spherical than the chip particles. Prior to drying, water was added to the particles to obtain 0.10, 0.30, 0.50, 0.70, and 0.90 moisture contents （on a dry mass basis）. The moistened particles were subsequently dried in a constant temperature thin layer dryer set at 50,100, 150, or 200 ~c under dry pure nitrogen, dry compressed air, or atmospheric air. The chip and pellet particles exhibited similar degrees of shrinkage, but the pellet particles underwent a greater reduction in their bulk volume during drying. It appears that the more spherical pellet particles are prone to shrinkage in more than one direction, whereas the needle-like chip particle shrink only in one direction. A variable radius first order drying model was found to fit the experimental data better than a fixed radius model.

关键词： Moisture loss Particle density Ground chip Ground pellet Particle shrinkage Bulk shrinkage

A variational energy approach for electromechanical analysis of thick piezoelectric beam

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2005年第9期6卷 962-966页

作者： lau c.w.H. LIM c.w. LEUNG A.Y.T Department of Building and construction City University of Hong KongDepartment of Building and Construction City University of Hong Kong Hong Kong ChinaDepartment of Building and Construction City University of Hong Kong Hong Kong China Hong Kong China Department of construction Institute of Vocational Education (Tsing Yi) Hong Kong China

A new two dimensional coupled electromechanical model for a thick, laminated beam with piezoelectric and isotropic lamina subjected to static external electric loading is developed. The model combined the first order shear deformation theory for the relatively thick elastic core and linear piezoelectric theory for the piezoelectric lamina. The actuation response is induced through the application of external electric voltage. Rayleigh-Ritz method is adopted to model the displacement and potential fields of the beam and governing equations were finally derived from the variational energy principle. The model allows the piezoelectric lamina to be formulated via a two-dimensional model because of the strong electro-mechanical coupling and the presence of a two-dimensional electric field. Numerical examples of piezoelectric laminated beam are presented. It is shown in this paper that a one-dimensional model for the piezoelectric beam-like layer is inadequate.

关键词： Energy Electromechanical Linear piezoelectricity Ritz method Thick beam

Zinc-oxide/PDMS-clad tapered fiber saturable absorber for passively mode-locked erbium-doped fiber laser

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chinese Physics B 2021年第5期30卷 384-389页

作者： F D Muhammad S A S Husin E K Ng K Y lau c A c Abdullah M A Mahdi Department of Physics Faculty of ScienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia wireless and Photonics Networks Research centre Faculty of EngineeringUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Department of Electronics and Nanoengineering Tietotie 3Aalto University02150 EspooFinland

we propose and demonstrate a passively mode-locked erbium-doped fiber laser(EDFL)based on zinc-oxide/polydimethylsiloxane(ZnO/PDMS)saturable absorber(SA)that evanescently interacts with the light on a tapered *** ZnO/PDMS composite is coated on the whole surface of the tapered fiber to guarantee the maximum efficiency of the SA device,with a measured insertion loss of 0.87 dB and a modulation depth of 6.4%.The proposed laser can generate soliton mode-locking operation at a threshold power of 33.07 *** generated output pulse yields a repetition rate and pulse width of 9.77 MHz and 1.03 ps,*** results indicate that the proposed ZnO/PDMS-clad tapered fiber could be useful as an efficient,compatible,and low.cost SA device for ultrafast laser applications.

关键词： zinc-oxide saturable absorber tapered fiber mode-locked fiber laser

Development and controversies of adjuvant therapy for pancreatic cancer

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Hepatobiliary & Pancreatic Diseases International 2008年第2期7卷 121-125页

作者： wan-Yee lau Eric c.H.Lai Faculty of Medicine the Chinese University of Hong Kong Prince of Wales Hospital Shatin New TerritoriesHong Kong SAR China

BAcKGROUND: Pancreatic cancer is an aggressive malignancy with a dismal prognosis. Radical surgery provides the only chance for a cure with a 5-year survival rate of 7%-25%. An effective adjuvant therapy is urgently needed to improve the surgical outcome. This review describes the current status of adjuvant therapy for pancreatic cancer, and highlights its controversies. DATA SOURcES: A Medline database search was performed to identify relevant articles using the keywords 'pancreatic neoplasm', and 'adjuvant therapy'. Additional papers were identified by a manual search of the references from the key articles. RESULTS: Eight prospective randomized controlled trials (RcTs) on the use of adjuvant chemotherapy and chemoradiation for pancreatic cancer could be identified. The results for adjuvant regimens based on systemic 5-fluorouracil with or without external radiotherapy were conflicting. The recent two RcTs on gemcitabine based regimen gave promising results. cONcLUSIONS: Based on the available data, no standard adjuvant therapy for pancreatic cancer can be established yet. The best adjuvant regimen remains to be determined in large-scale RcTs. Future trials should use a gemcitabine based regimen.

关键词： pancreatic neoplasm pancreatectomy adjuvant therapy radiotherapy chemotherapy

classification of iatrogenic bile duct injury

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Hepatobiliary & Pancreatic Diseases International 2007年第5期6卷 459-463页

作者： wan-Yee lau Eric c.H.Lai Department of Surgery the Chinese University of Hong KongShatinNew TerritoriesHong Kong SARChina

BAcKGROUND: Iatrogenic bile duct injury continues to be an important clinical problem, resulting in serious morbidity, and occasional mortality, to patients. The ease of management, operative risk, and outcome of bile duct injuries vary considerably, and are highly dependent on the type of injury and its location. This article reviews the various classification systems of bile duct injury. DATA SOURcES: A Medline, PubMed database search was performed to identify relevant articles using the keywords 'bile duct injury', 'cholecystectomy', and 'classification'. Additional papers were identified by a manual search of the references from the key articles. RESULTS: Traditionally, biliary injuries have been classified using the Bismuth's classification. This classification, which originated from the era of open surgery, is intended to help the surgeons to choose the appropriate technique for the repair, and it has a good correlation with the final outcome after surgical repair. However, the Bismuth's classification does not encompass the whole spectrum of injuries that are possible. Bile duct injury during laparoscopic cholecystectomy tends to be more severe than those with open cholecystectomy. Strasberg's classification made Bismuth's classification much more comprehensive by including various other types of extrahepatic bile duct injuries. Our group, Bergman et al, Neuhaus et al, csendes et al, and Stewart et al have also proposed other classification systems to complement the Bismuth's classification. cONcLUSIONS: None of the classification system is universally accepted as each has its own limitation. Hopefully, a universally accepted comprehensive classification system will be published in the near future.

关键词： laparoscopic cholecystectomy bile duct injury bile duct stricture bile leak classification

Hepatocellular carcinoma: current management and recent advances

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Hepatobiliary & Pancreatic Diseases International 2008年第3期7卷 237-257页

作者： wan-Yee lau Eric c. H. Lai Faculty of Medicine The Chinese University of Hong Kong Prince of Wales Hospital Shatin New Territories Hong Kong SAR China

BAcKGROUND: Hepatocellular carcinoma (Hcc) is a major health problem worldwide. It is the fifth most common cancer in the world, and the third most common cause of cancer-related death. without specific treatment, the prognosis is very poor. The goal of management is 'cancer control'-a reduction in its incidence and mortality as well as an improvement in the quality of life of patients with Hcc and their families. This article aims to review the current management of Hcc and its recent advances. DATA SOURcES: A MEDLINE database search was performed to identify relevant article using the keywords 'hepatocellular carcinoma', 'hepatectomy', 'liver transplantation', and 'local ablative therapy'. Additional papers and book chapters were identified by a manual search of the references from the key articles. RESULTS: Liver resection and liver transplantation remain the options that give the best chance of a cure. Recent evidence suggests that local ablative therapy may offer comparable survival results in patients with small Hcc, and preserved liver function. Transarterial chemoembolization (TAcE) is the most promising palliative modality for unresectable Hcc, but other techniques, such as transarterial radioembolization (TARE), and local ablative therapy, have also shown comparable results. cONcLUSIONS: Early diagnosis of Hcc remains a key goal in improving the prognosis of patients. During the last two decades, operative mortality and surgical outcome of liver resection and liver transplantation for Hcc have improved. Progress also has been made in multi-modality therapy which can increase the chance of survival and improve the quality of life for patients with advanced Hcc.

关键词： hepatocellular carcinoma hepatectomy liver transplantation local ablative therapy

Epidemiological, Diagnostic, Therapeutic and Progressive Aspects of Arterial Hypertension in children at the University Hospital center of Bouaké (côte d’Ivoire)

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Open Journal of Pediatrics 2024年第2期14卷 379-390页

作者： Richard Azagoh-Kouadio Yao Kossonou Roland Yeboua Kouassi christian Yao John patrick Yenan Iburaima Alamun Akanji Kouadio Vincent Assé Pediatric Department of Angré University Hospital Abidjan Ivory Coast Pediatric Department of Bouaké University Hospital Bouaké Ivory Coast

Introduction: Arterial hypertension (AH) in children is under-diagnosed and often has a poor prognosis. The aim of this study was to describe the epidemiological, diagnostic, therapeutic and evolutionary aspects of hypertension in children at the University Hospital of Bouaké, with a view to improving the prognosis. Methods: This was a cross-sectional, analytical study carried out in the paediatrics department of Bouaké University Hospital. It concerned the medical records of children aged 4 to 15 hospitalised from 1 January 2017 to 31 December 2020 for hypertension. Diagnosis was based on the simplified blood pressure guidelines of the Expert consensus of the French Society of Hypertension. The variables studied were epidemiological, diagnostic, therapeutic and evolutionary. Quantitative variables were compared at the significance level p ≤ 0.05. Results: The hospital incidence of hypertension was 0.32% (69/21,642). The sex ratio was 0.72. 97.1% of the children were over five years of age. Oedema (49.3%) and breathing difficulties (20.2%) were the main reasons for consultation. Hypertension was classified as threatening (56.5%), confirmed (31.9%) and borderline (11.6%). The cause was renal in 66.7%, dominated by impure nephrotic syndrome (24.6%). Treatment for hypertension consisted mainly of a diuretic (79.7%) and a calcium channel blocker (47.8%). Outcome was favourable in 50.7% of cases. Mortality was 20.3%. No factor was significantly associated with death. conclusion: Hypertension in children at Bouaké University Hospital is serious. The aetiology is mainly renal. Early diagnosis and management are key to improving prognosis.

关键词： Hypertension children Renal Pathologies Prognosis côte d’Ivoire

Development and Validation of an Instrument to Measure STEM Undergraduate Students’ comprehensive Educational Process

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Frontiers of Education in china 2019年第4期14卷 575-611页

作者： ZHUANG Tengteng cHEUNG Alan c.K. lau wilfred w.F. TANG Yipeng Department of Educational Administration&Policy Faculty of EducationThe Chinese University of Hong KongHong KongChina Department of curriculum and Instruction Faculty of EducationThe Chinese University of Hong KongHong KongChina college of Education Capital Normal UniversityBeijing 100089China

This study reports the development and validation of an instrument,“Undergraduate STEM Educational Process Questionnaire”(USEPQ)to assess the learning experiences of STEM(science,technology,engineering and mathematics)-major undergraduates from the perspective of a conceptualized comprehensive STEM educational process framework that consists of key essentials such as course learning and instruction,educational environment,assessment methods,and unique STEM *** Factor Analysis and confirmatory Factor Analysis performed on independent samples indicate that the finalized 9-factor,41-item USEPQ possesses a stable factor structure and sound psychometric *** factors of the validated scale are classroom Instruction of courses,Support from Faculty Members,Alternative Assessment Methods,cooperative Learning,Resources and Service,Academic competition,cross-discipline Features of Program courses,connectedness of Program courses,and Examination Difficulty.

关键词： higher education educational process STEM program,measurement instrument development and validation

Impact of vasculature damage on the outcome of spinal cord injury:a novel collagenase-induced model may give new insights into the mechanisms involved

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Neural Regeneration Research 2014年第20期9卷 1783-1786页

作者： patrick Losey Daniel c.Anthony Experimental Neuropathology Department of PharmacologyUniversity of OxfordOxfordUK

The deleterious effect of vasculature damage on the outcome of spinal cord injury has long been recognized, and numerous clinical studies have shown that the presence of hemorrhage into the spinal cord is directly associated with a poorer neurological outcome. Vascular damage leads to de- creased blood flow to the cord and the release of potentially toxic blood-borne components. Here we consider the mechanisms that may be contributing to hemorrhage-induced damage and discuss the utility of a new model of spinal cord hemorrhage, which was urgently required as most of our current understanding has been extrapolated from intracerebral hemorrhage studies.

关键词： spinal cord injury vasculature hemorrhage animal model collagenase stereotaxic microinjection