scholarly journals Simulation and Analysis of Induced Current of HV Parallel Reactor Disconnector for 500kV Double Circuit Line on the Same Tower

2020 ◽  
Vol 185 ◽  
pp. 01043
Author(s):  
Haisheng Li ◽  
Jianquan Zhang ◽  
Boyi Fang ◽  
Bin Liu ◽  
Bin Feng
Keyword(s):  
Operation Mode ◽  
Induced Current ◽  
Ice Melting ◽  
Related Factors ◽  
Type Selection ◽  
Cold Standby ◽  
Double Circuit Line ◽  
B Lines ◽  
Parallel Reactor

The 500 kV double circuit line with HV parallel reactors has a long outage time in ice melting operation.In this paper, we discussed the possibility of directly switching HV parallel reactor disconnector under the cold standby state,in order to further optimize the operation mode of DC ice melting line.We calculated the induced current of the HV parallel reactors disconnector in the 500kV LG A and B lines, and analyzed the related factors. We also calculate the overvoltage level of the HV parallel reactor disconnector, and put forward the parameter requirements, which provides reference for the type selection.

scholarly journals Assessment of the risk of cardiovascular diseases among the staff members of law enforcement body who work in counter-terrorist operation mode and live in the Republic of Dagestan

2018 ◽  
Vol 99 (3) ◽  
pp. 432-438
Author(s):  
A Kh Omarova ◽  
G V Arkad'eva
Keyword(s):  
Risk Factors ◽  
Cardiovascular Diseases ◽  
Law Enforcement ◽  
Arterial Hypertension ◽  
Blood Pressure Monitoring ◽  
Operation Mode ◽  
Excess Body Weight ◽  
Related Factors ◽  
Staff Members ◽  
The Republic

Aim. Early identification of risk factors of cardiovascular diseases in staff members of law enforcement body working in counter-terrorist operation mode in the Republic of Dagestan and evaluation of their overall cardiovascular risk. Methods. 62 employees (males, average age 35.2±4.1 years) were the object of study. The follow-up period was 3.7±0.7 years. The examination included laboratory studies, electrocardiography, echocardiography, 24-hour blood pressure monitoring, duplex study of brachiocephalic arteries, examination of the vessels of the fundus. Results. The following risk factors were identified: arterial hypertension, dyslipidemia, excess body weight, smoking. Conclusion. Law enforcement officers are exposed to a range of unfavorable work-related factors (severity and labor intensity) in the course of labor activity, which are associated with operational activity of the Ministry of Internal Affairs employees and enable formation of risk factors of cardiovascular pathology (such as arterial hypertension, overweight, smoking).

Numerical simulation of the fire emergency evacuation for a metro platform accident

SIMULATION ◽  
2020 ◽  
Vol 97 (1) ◽  
pp. 19-32
Author(s):  
Jiabin Xie ◽  
Kecheng Chen ◽  
Trevor Hocksun Kwan ◽  
Qinghe Yao
Keyword(s):  
Operation Mode ◽  
Coupled Model ◽  
Emergency Evacuation ◽  
Coupled Analysis ◽  
Escape Time ◽  
Evacuation Simulation ◽  
Related Factors ◽  
Crowd Density ◽  
Fire Evacuation ◽  
Fire Location

A coupled analysis of agent behavior and Computational Fluid Dynamics (CFD) model is applied to investigate the fire evacuation effectiveness in a popular metro station in Guangzhou, China. Due to the high density and complexity of traffic, the concept of Required Safe Escape Time and Available Safe Escape Time (RSET/ASET), which is more flexible and adaptable than the “6 minutes” principle, is applied in the safety assessment of fire evacuation. To pursue a stable simulation of the coupled model, the standard Critical Radiant Flux is used to deter the tenability criteria for exposure to fire and heat. Various related factors, including the fire location, the Heat Release Rate (HRR) of fire, the crowd density, and the operation mode of escalators, are analyzed through a series of simulations. Results indicate that the interaction between fire and humans should not be neglected in the evacuation simulation. Both the fire location and the crowd density have a significant effect on the evacuation, while the HRR of fire has a minor impact. When the accident happens at the entrance of an escalator, RSET is 58.3% longer than that when the accident occurs in the middle of the platform. RSET grows with the increase of the crowd density linearly. Besides, the evacuation efficiency could be partly improved by changing escalators that usually operate in the descending mode into ascending mode.

scholarly journals Summary of  perioperative calcium regulation therapy and analysis of related factors in the treatment of secondary hyperparathyroidism

2020 ◽  
Author(s):  
XinSheng Zhang ◽  
weibin zhang ◽  
Jia Dong ◽  
YunFei Wu ◽  
Bin Zheng ◽  
...  
Keyword(s):  
Secondary Hyperparathyroidism ◽  
Clinical Data ◽  
Operation Mode ◽  
Calcium Regulation ◽  
Control Group ◽  
Observation Group ◽  
Related Factors ◽  
Blood Calcium ◽  
Regulation Scheme ◽  
Significant Difference

Abstract Background：Retrospectively register the clinical data of secondary hyperparathyroidism（SHPT）patients who received surgical treatment, summarize the postoperative calcium regulation scheme in details and analyze statistically related factors for guiding clinical early intervention and evaluating prognosis.Methods: Review the clinical data of 136 patients with chronic renal failure in uremic stage from Jinzhou Central Hospital and the Second Affiliated Hospital of Dalian Medical University, who received dialysis treatment for a long time and finally diagnosed as secondary hyperparathyroidism, from Jan 2017 to Dec 2019, were accepted different operations to treat hyperparathyroidism, were given corresponding calcium regulation therapy to avoid serious complicationswere, and were divided into the observation group and the control group according to the postoperative calcium regulation time of ≤7days and > 7days, which is defined as the time from the day of operation until the day when the patients have stable blood calcium levels and no obvious discomfort symptoms.Results: The difference between the two groups was statistically significant (P<0.001); Compared with the control group, the observation group were elder(54.01±9.215; P<0.01), shorter preoperative dialysis time (5.05±2.855; P<0.01); significant difference in operation mode (P=0.026); positive preoperative oral calcium(c2=9.941, P=0.002), higher preoperative calcium value (t=4.795; P<0.001), lower preoperative Parathyroid Hormone(PTH) value (t=6.327; P<0.001), lower preoperative Alkaline phosphatase(ALP) value (t=3.527; P=0.001); Multivariate analysis showed that age, preoperative calcium value, preoperative PTH value and preoperative ALP value were independent risk factors for postoperative calcium regulation therapy. Those factors, Gender, preoperative dialysis mode, complications, preoperative Hemoglobin(HB) value, were not related to postoperative calcium regulation. There was no significant difference between the two groups (P>0.05).Conclusion: Effective postoperative calcium regulation can maintain a stable level of blood calcium in the patients with secondary hyperparathyroidism, so as to avoid the occurrence of severe hypocalcemia.

scholarly journals Recurrence characteristics and clinicopathological results of borderline ovarian tumors

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lina Niu ◽  
Huihui Tian ◽  
Yongjun Xu ◽  
Jieqiong Cao ◽  
Xu Zhang ◽  
...  
Keyword(s):  
Operation Mode ◽  
Clinical Manifestations ◽  
Figo Stage ◽  
Ovarian Tumors ◽  
Recurrence Rates ◽  
Related Factors ◽  
Carbohydrate Antigen 125 ◽  
Borderline Ovarian Tumors ◽  
Gynecology And Obstetrics

Abstract Background This study aimed to investigate the clinical and pathological characteristics, and the recurrence and prognostic factors of borderline ovarian tumors (BOTs). Methods The data of 286 patients admitted to hospital and followed up for more than ten months were analyzed retrospectively to study the clinicopathological characteristics and related factors of recurrence. Results The median age of the patients was 42.06 ± 14.97 years, and the duration of the follow-up ranged from 10–109 months. During the follow-up period, 40 patients had a recurrence. Of these patients, 36 were ≤ 40 years, and patients with premenopausal recurrence accounted for 20.5% (36/176). In patients undergoing conservative treatment or radical operations, the recurrence rates were 21.3% and 1.8%, respectively, and they were 13.4% (36/268) in patients at Federation International of Gynecology and Obstetrics (FIGO) stage I, and 22.2% (4/18) in patients at an advanced stage. Postoperative pathology revealed that 40 patients had micropapillary tumors, among whom ten patients (25%) had a recurrence, and 19 patients had complications with interstitial infiltration. Of these 19 patients, six had a recurrence (31.5%). Another 22 patients had complications with calcified sand bodies; among these, eight patients (36.4%) had a recurrence. All the differences were statistically significant (P < 0.05). There were four cancer-related deaths during the follow-up period. Late FIGO stage, conservative operation, and a high level of carbohydrate antigen 125 (CA125) were independent risk factors for the recurrence of BOTs. Conclusion BOTs usually occur in women under 40 years, have an occult onset, and half of the patients have no obvious clinical manifestations. Serum CA125 level can be used as a tumor marker to detect BOTs and the risk of its recurrence. Operation mode and FIGO stage are important independent factors for the recurrence of BOTs.

Practical Importance of Spatial Resolution and Analytical Sensitivity in AEM X-ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 432-433
Author(s):  
J. Zhang ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Spatial Resolution ◽  
Practical Importance ◽  
Beam Current ◽  
Specimen Thickness ◽  
Analytical Sensitivity ◽  
Related Factors ◽  
X Ray ◽  
Probe Size ◽  
Excitation Volume ◽  
Two Parameters

Analytical sensitivity and spatial resolution are important and closely related factors in x-ray microanalysis using the AEM. Analytical sensitivity is the ability to distinguish, for a given element under given conditions, between two concentrations that are nearly equal. The analytical sensitivity is directly related to the number of x-ray counts collected and, therefore, to the probe current, specimen thickness and counting time. The spatial resolution in AEM analysis is determined by the probe size and beam broadening in the specimen. A finer probe and a thinner specimen give a higher spatial resolution. However, the resulting lower beam current and smaller X-ray excitation volume degrade analytical sensitivity. A compromise must be made between high spatial resolution and an acceptable analytical sensitivity. In this paper, we show the necessity of evaluating these two parameters in order to determine the low temperature Fe-Ni phase diagram.A Phillips EM400T AEM with an EDAX/TN2000 EDS/MCA system and a VG HB501 FEG STEM with a LINK AN10 EDS/MCA system were used.

Electron beam induced current study of thin silicon layers on insulator substrate

1990 ◽  
Vol 48 (4) ◽  
pp. 618-619
Author(s):  
A. Buczkowski ◽  
Z. J. Radzimski ◽  
J. C. Russ ◽  
G. A. Rozgonyi
Keyword(s):  
Electron Beam ◽  
Energy Loss ◽  
Beam Energy ◽  
Collection Efficiency ◽  
Silicon Layer ◽  
Depletion Layer ◽  
Incident Electron Energy ◽  
Induced Current ◽  
Electron Hole ◽  
Electron Beam Induced Current

If a thickness of a semiconductor is smaller than the penetration depth of the electron beam, e.g. in silicon on insulator (SOI) structures, only a small portion of incident electrons energy , which is lost in a superficial silicon layer separated by the oxide from the substrate, contributes to the electron beam induced current (EBIC). Because the energy loss distribution of primary beam is not uniform and varies with beam energy, it is not straightforward to predict the optimum conditions for using this technique. Moreover, the energy losses in an ohmic or Schottky contact complicate this prediction. None of the existing theories, which are based on an assumption of a point-like region of electron beam generation, can be used satisfactorily on SOI structures. We have used a Monte Carlo technique which provide a simulation of the electron beam interactions with thin multilayer structures. The EBIC current was calculated using a simple one dimensional geometry, i.e. depletion layer separating electron- hole pairs spreads out to infinity in x- and y-direction. A point-type generation function with location being an actual location of an incident electron energy loss event has been assumed. A collection efficiency of electron-hole pairs was assumed to be 100% for carriers generated within the depletion layer, and inversely proportional to the exponential function of depth with the effective diffusion length as a parameter outside this layer. A series of simulations were performed for various thicknesses of superficial silicon layer. The geometries used for simulations were chosen to match the "real" samples used in the experimental part of this work. The theoretical data presented in Fig. 1 show how significandy the gain decreases with a decrease in superficial layer thickness in comparison with bulk material. Moreover, there is an optimum beam energy at which the gain reaches its maximum value for particular silicon thickness.

Voice Therapy With Seniors: Attendance, Outcomes, and Associated Patient Characteristics

2019 ◽  
Vol 4 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Bonnie E. Smith ◽  
Ruth Huntley Bahr ◽  
Hector N. Hernandez
Keyword(s):  
Outcome Data ◽  
Voice Therapy ◽  
Similar Data ◽  
Success Rates ◽  
Reflux Symptom Index ◽  
Voice Change ◽  
Related Factors ◽  
Symptom Index ◽  
Younger Patients ◽  
Unsuccessful Treatment

Purpose The purpose of this study was to determine the attendance and success rates for seniors in voice therapy, identify any contributing patient-related factors, and compare results to existing findings for younger patients. Method This retrospective study included information from the voice records of 50 seniors seen by the same speech-language pathologist in a private practice. Analysis of attendance and outcome data divided participants into 6 groups. Outcomes for Groups 1–3 (64% of patients) were considered successful (positive voice change), while outcomes for Groups 4–6 (36% of patients) were considered unsuccessful. These data were compared to similar data collected for younger adults in a previous study. Results The attendance and success rates for seniors in this study were higher than those previously reported for younger patients. Further consideration of patient factors revealed that reports of increased stress, Reflux Symptom Index scores > 13, and higher Voice Handicap Index functional subscale scores were significant in distinguishing between patients in the successful and unsuccessful treatment outcome groups. Conclusions The relatively high attendance and success rates among this sample of seniors suggest the desire to achieve voice improvement does not diminish with age, and chances for success in voice therapy among nonfrail seniors may be greater than for younger patients.

Obstacles to Claiming Permanence and Injury-Relatedness for “Posttraumatic” Headache

2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth
Keyword(s):  
Complete Recovery ◽  
World Health ◽  
Related Factors ◽  
Posttraumatic Headache ◽  
Sixth Edition ◽  
Causative Relationship ◽  
Short Period ◽  
The One ◽  
Health Organization ◽  
Subjective Reports

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.

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