Search results for " shock"
showing 10 items of 691 documents
Currents Distribution During a Fault in an MV Network: Methods and Measurements
2016
When a single line to ground fault happens on the MV side of a HV/MV system, only a small portion of the fault current is injected into the ground by the ground-grid of the faulty substation. In fact the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real single line to ground fault was made and fault currents were measured in the faulty substation and in four neighboring substations. In this paper the problem of fault current distribution is introduced, the tes…
A Simple Method for Evaluating Ground-Fault Current Transfer at the Transition Station of a Combined Overhead-Cable Line
2008
When a substation is fed by a combined overhead-cable transmission line, a significant part of the ground fault current flows through cable sheaths and is discharged into the soil at the transition station where cables are connected to the overhead line. Such a phenomenon, known as ldquofault application transfer,rdquo may result in high ground potentials at the transition station which may cause shocks and equipment damage. The scope of this paper is to present new analytic formulas which can be used for the direct calculation of the fault current transferred at the transition station and its ground potential rise as well as the substation earth current. The proposed formulas allow evaluat…
Effects of double ground faults in Wind Farms collector cables
2015
Medium Voltage collector cables of Wind Farms have metal shields connected to the grounding systems of the towers and of the connection station. Thanks to this bonding, when a ground fault occurs, the fault current splits itself among all the grounding systems of the wind farm, this causing a reduction of the ground potential rise at the fault location. Nevertheless, in presence of double ground faults, very high ground potential rises occur at the two fault locations and safety against electric shock is not always assured. In order to study this issue, the paper presents a model for simulating in a simple way the effects of double ground faults occurring in Medium Voltage collectors of ext…
Current and Voltage Behaviour During a Fault in a HV/MV System: Methods and Measurements
2015
When a single line to ground fault happens on the MV side of a HV/MV system, only a small portion of the fault current is injected into the ground by the ground-grid of the faulty substation. In fact the fault current is distributed between grounding electrodes and MV cables sheaths. In systems with isolated neutral or with resonant earthing this may be sufficient to provide safety from electric shock. Experimental measurements were performed on a real MV distribution network: a real single line to ground fault was made and fault currents were measured in the faulty substation and in four neighbouring substations. In this paper the problem of fault current distribution is introduced, the te…
The Effect of Systemic Banking Crises on Entrepreneurship
2014
Economic crises have mixed effects on entrepreneurship. Through demand shocks, credit constraints, and unemployment, systemic banking crises affect the rate of start-up business creation, although the extent of their impact varies. Consequently, previous studies on the effect of crises on Entrepreneurship are inconclusive. The surge of global demand coupled with low credit availability reduces the prospects for new businesses. On the other hand, job losses caused by an economic crisis might lead many entrepreneurs to undertake new projects. These inconsistent conclusions highlight the need for more studies that explore the effect of systemic banking crises on entrepreneurship. This article …
Small heat shock proteins and the cytoskeleton: an essential interplay for cell integrity?
2012
Abstract The cytoskeleton is a highly complex network of three major intracellular filaments, microfilaments (MFs), microtubules (MTs) and intermediate filaments (IFs). This network plays a key role in the control of cell shape, division, functions and interactions in animal organs and tissues. Dysregulation of the network can contribute to numerous human diseases. Although small HSPs (sHSPs) and in particular HSP27 (HSPB1) or αB-crystallin (HSPB5) display a wide range of cellular properties, they are mostly known for their ability to protect cells under stress conditions. Mutations in some sHSPs have been found to affect their ability to interact with cytoskeleton proteins, leading to IF a…
Is it possible to change of the duration of consolidation period in the distraction osteogenesis with the repetition of extracorporeal shock waves?
2016
Background In this study we examined the effects of two different repeated Extracorporeal Shock Waves (ESW) on the consolidation period of the distraction osteogenesis (DO) of the rabbit mandible using stereological, radiological and immunohistochemical methods. Material and Methods DO was performed unilaterally in the mandible of 18 New Zealand rabbits (six months old, weighing between 2.5-3 kg). In the consolidation period, rabbits were divided into three groups randomly after the distraction period. The distraction zone of the mandible was received no treatment as controls (E0*2). Group 2 (E 500*2) received ESWT (twice 500 impulses at 14 kV and 0.19 mJ/mm2 energy) in the first and fourth…
Extracorporeal Shock Waves Increase Markers of Cellular Proliferation in Bronchial Epithelium and in Primary Bronchial Fibroblasts of COPD Patients
2020
Chronic obstructive pulmonary disease (COPD) is due to structural changes and narrowing of small airways and parenchymal destruction (loss of the alveolar attachment as a result of pulmonary emphysema), which all lead to airflow limitation. Extracorporeal shock waves (ESW) increase cell proliferation and differentiation of connective tissue fibroblasts. To date no studies are available on ESW treatment of human bronchial fibroblasts and epithelial cells from COPD and control subjects. We obtained primary bronchial fibroblasts from bronchial biopsies of 3 patients with mild/moderate COPD and 3 control smokers with normal lung function. 16HBE cells were also studied. Cells were treated with a…
Exposure to radial extracorporeal shockwaves induces muscle regeneration after muscle injury in a surgical rat model
2019
The leading cause of training interruption in sport is a muscle injury, for which the standard treatment is nonsteroidal anti-inflammatory drugs (NSAIDs). To find alternative treatments, we investigated whether the radial extracorporeal shockwave application (rESWT) could stimulate muscle regeneration. A lesion with complete rupture (grade III muscle tear) was set in the musculus rectus femoris of 12-week-old Wistar rats, and the NSAID diclofenac, rESWT, or a combined therapy were applied on day 0, 3, and 5 directly following the surgery. Rats were euthanized at 2, 4, and 7 days after surgery and the area of muscle lesion was excised for histological and gene expression analysis to determin…
Urology Residency Training in Italy: Results of the First National Survey
2018
Background: Numerous surveys have been performed to determine the competence and the confidence of residents. However, there is no data available on the condition of Italian residents in urology. Objective: To investigate the status of training among Italian residents in urology regarding scientific activity and surgical exposure. Design, setting, and participants: A web-based survey that included 445 residents from all of the 25 Italian Residency Programmes was conducted between September 2015 and November 2015. Outcome measurements and statistical analysis: The main outcomes were represented by scientific activity, involvement in surgical procedures, and overall satisfaction. Results and …