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Hangzhou, China

Zhejiang University of Science and Technology is a public university located in Hangzhou, Zhejiang province, China. Wikipedia.


Sha Y.,Zhejiang University of Science and Technology
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2011

In order to research the performances and internal flow characteristics of vortex pump, the vortex pump suction, head and cavitation principles were illustrated, and the fact that q v-NPSH performance curve is falling parabolic was obtained after experiment on the vortex pump (32WB8-12) prototype and measurement of flow field in chamber with 5-hole spherical probe. Based on the simulation of the three-dimensional internal flow within vortex pump utilizing RNG k-ε turbulence model, the certain fidelity and accuracy of the numerical simulation results were verified by comparing between simulation and experiment. From these results, the conclusion is that the internal flow in vortex pump mainly consists of through flow, and the forced vortex is the main flow characteristics in the impeller region, and the flow in volute is similar to the combined vortex with backflow, circular flow and free vortex, which is non-axisymmetric unsteady flow with quite high turbulence intensity, and all these lead to the relative low efficiency of the vortex pump. Source


Ye Y.,Zhejiang University of Science and Technology
Nonlinear Analysis: Real World Applications | Year: 2013

This paper deals with the initial-boundary value problem for a class of nonlinear higher-order Kirchhoff-type equation with dissipative term u tt+|A1/2u|2pAu+a|ut| q-2ut=b|u|r-2u, x∈Ω,t>0 in a bounded domain, where A=(-Δ)m, m>1 is a positive integer, a,b,p>0 and q,r>2 are constants. We obtain the global existence of solutions by constructing a stable set in H0m(Ω) and show the energy decay estimate by applying a lemma of V. Komornik. © 2013 Elsevier Ltd. All rights reserved. Source


Ge Z.,Zhejiang University of Science and Technology
Chemometrics and Intelligent Laboratory Systems | Year: 2014

In modern industries, the plant-wide process has become more and more popular, which always consists of various operation units, equipments, workshops and even factories. Therefore, it is more difficult to monitor those processes, and the monitoring complexity is also much higher. While the traditional multivariate statistical analysis provides satisfactory monitoring results within a single part, e.g. operation unit, it may fail to catch the detailed cross-information among different parts of the process. In this paper, an improved two-level monitoring system is formulated for plant-wide processes. In the first level, the latent variable information is extracted by the principal component analysis (PCA) model, based on which a global latent variable matrix is generated by combining latent variables from different parts of the process. In order to characterize the cross-data information of the plant-wide process, an efficient support vector data description (SVDD) method is employed for modeling the relationships among the global latent variable matrices. Based on the results of the Tennessee Eastman (TE) process, an enhanced performance is obtained by the improved two-level monitoring system. Compared to the traditional PCA based monitoring strategy, the new method is useful to describe the cross-data information of the plant-wide process, based on which more accurate monitoring results can be obtained. © 2014 Elsevier B.V. Source


Bing-Hua Y.U.,Zhejiang University of Science and Technology
American Journal of Surgery | Year: 2014

Background Shortage of beds in intensive care units (ICUs) is an increasing common phenomenon worldwide. Consequently, many critically ill patients have to be cared for in other hospital areas without specialized staff, such as general wards, emergency department, post anesthesia care unit (PACU). However, boarding critically ill patients in general wards or emergency department has been associated with higher mortality. The purpose of this study was to evaluate if a delay in ICU admission, waiting in PACU and managed by anesthesiologists, affects their ICU outcomes for critically surgical patients. Methods A retrospective cohort of adult critically surgical patients admitted to our ICU between January 2010 and June 2012 were analyzed. ICU admission was classified as either immediate or delayed (waiting in PACU). A general estimation equation was used to examine the relationship of PACU waiting hours before ICU admission with ICU outcomes by adjusting for age, patient sex, comorbidities, surgical categories, end time of operation, operation hours, and clinical conditions. Results A total of 2,279 critically surgical patients were evaluated. Two thousand ninety-four (91.9%) patients were immediately admitted and 185 (8.1%) patients had delayed ICU admission. There was a significant increase in ICU mortality rates with a delay in ICU admission (P <.001). Prolonged waiting hours in PACU (≥6 hours) was associated with higher ICU mortality (adjusted odds ratio 5.32; 95% confidence interval 1.25 to 22.60, P =.024). However, longer PACU waiting times was not associated with mechanical ventilation days, ICU length of stay, and ICU cost. Conclusion Prolonged waiting hours in PACU because of ICU bed shortage was associated with higher ICU mortality for critically surgical patients. © 2014 Elsevier Inc. All rights reserved. Source


To explore the safety and short-term efficacy of the posterior approach of the Dynesys dynamic neutralization system for degenerative disease of the lumbar vertebrae. From March 2008 to March 2010, 32 cases of degenerative lumbar vertebral disease, 19 men and 13 women, (mean age 58 ± 5.2, range, 43-78 years), were treated with posterior laminectomy and Dynesys internal fixation. All patients had a history of over 3 months waist or leg pain that had not been relieved by conservative treatment. There were 10 cases of single lumbar intervertebral disc protrusion, 14 of degenerative lumbar spinal stenosis, 5 of degenerative lumbar isthmic spondylolisthesis, and 3 of recurrent lumbar disc protrusion after surgery. A visual analogue score (VAS) was used for pain assessment, and the Oswestry disability index (ODI) for functional evaluation of clinical outcomes. All patients were followed up for 6-23 months (mean, 16.4 ± 5.5 months). Forty-one segments in 32 patients were stabilized; 23 cases (71.9%) underwent single-segmental stabilization, and 9 (28.1%) two-segmental stabilization. VAS of leg pain, root and low back pain was significantly improved postoperatively. The ODI improved from preoperative 69% ± 12.6% to postoperative 28% ± 15.7% (P < 0.001). On the stabilized segment and adjacent segments above and below, the range of movement showed no statistical difference; no loosening of screws, cord and polyester spacer occurred. The Dynesys dynamic neutralization system combined with decompression can achieve satisfactory short-term clinical results in lumbar degenerative disease. This procedure system not only reduces back and leg pain, but also preserves the mobility of fixed segments, minimizes tissue injury and avoids taking bone for spinal fusion. © 2011 Tianjin Hospital and Blackwell Publishing Asia Pty Ltd. Source

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