There are several causes of slip and fall accidents, such as floor and outsole surface characteristics, contaminants, environmental and human factors, and cognition. In relation to controllable causes, floor and outsole surface characteristics have been frequently investigated over the past decades. The characteristics of safety footwear outsoles, such as roughness, hardness, and tread pattern, tend to differ from those of casual shoes on the Korean market. The aim of this study is to investigate the slip resistance of safety footwear on the Korean market and determine the major design factors to improve the slip resistance. All friction tests were performed using the Korean Occupational Safety and Health Agency’s newly developed testing machine. Twenty-eight safety shoes were used in this experiment, and all friction tests were conducted under three different contamination conditions, namely water, detergent, and glycerol. The friction measurement results show that the hardness, material, and patterns of outsoles had a major effect on the slip resistance, but the effects were not statistically significant for some safety footwear. In general, safety footwear that had a number of small extruded blocks shows good slip resistance. Safety footwear patterns that have many small raised blocks on the heel have a higher friction coefficient than the others. A lower outsole hardness also gives a higher coefficient of friction.
최근 화학 산업이 발전함에 따라 고압설비가 널리 이용되고 있다. 이러한 고압 설비는 편리성과 함께 많은 위험을 내포하고 있다. 파열판 안전장치는 고압설비의 안전사고로부터 설비와 생명을 보호하는 장치이다. 파열판 안전장치는 홀더, 파열판, 버큠서포트로 구성되어져 있으며, 다양한 환경 조건에서 부식되거나 파괴되는 단점이 있다. 본 논문에서는 부식저항성이 우수하여 파열판 안전장치의 소재로 많이 사용되고 있는 STS 316L stainless steel 소재를 이용해서 제작한 파열판 안전장치를 CATIA V5를 이용하여 3차원 모델링을 수행하고, 유한요소해석을 통하여 소재의 두께와 높이에 따라 파열판 안전장치의 파열에 영향을 미치는 요인을 분석하였다.Abstract - High pressure devices are used widely. Interest in rupture disc to people is the increases in protect of facilities and people. A rupture disc consists of mainly three parts: holder, plate and vacuum support. Rupture discs are rusted or destroyed by diverse environments. Rupture discs are made from STS 316L stainless steel because of its high corrosion resistance and yield strength. In this study, modeling of a rupture disc by CATIA V5 and finite element analysis by ANSYS were carried out. The finite element analysis results executed to predict properties of the rupture disc with thickness and height.Key words : high pressure device, rupture disc, safety relief valve, finite element analysis
Pasture management and utilization for beef production, and botanical composition of the pasture on 81 cooperate village farms in Cheju-Do were surveyed through questionnaires and site visits. The study period was 28 days from October 2 to October 30, 1985. The pasture consisted of 45% improved grassland, in which 24.3% of grass species were imported. The improved pastures were fertilized once a year 100-150㎏ urea/㏊. Grazing period of the pastures was about 5 months, beginning late April or early May (60.5% of the pastures) and ending early-or mid-November (80.3%). Distribution of types of vegetation was, in order of magnitude, native pasture (38.7%), improved pasture (24.3%), shrub(10.0%), unfavorable weeds (8.3%). Species found with the highest percentage was Zoysia japonica (73.9%) in the native pasture, Festuca arundinacea (40.3%) in the improved pasture and Pterfdium aquilium (54.4%) among unfavorable weeds.
Preservation of the spleen in distal pancreatectomy has recently attracted considerable attention. Our current study aimed in the first instance to define the safety of lap-WT in relation to the capacity of this technique to achieve preservation of the spleen and secondly to investigate the effectiveness of a planned lap-WT procedure or early conversion to lap-WT in selected patients with a large tumor attached to the splenic vessels.Among 1056 patients who underwent a laparoscopic distal pancreatectomy between January 2005 and December 2014 at our hospital, 122 (24.6 %) underwent lap-WT which were analyzed. The 122 patients were categorized into two groups chronologically (early group: 2005-2012, late group: 2013-2014).The median follow-up was 35 months, and the median operation time was 181 min. The median postoperative hospital stay was 7 days, and the median estimated blood loss was 316 ml. Postoperative complications occurred in 9 patients (7.3 %), including 4 patients (3.2 %) with major pancreatic fistula (ISGPF grade B, C). A reoperation to address postoperative bleeding was needed in one patient. During a median follow-up of 35 months, there were no clinical significant splenic infarctions or gastric varices in any case. All patients were observed conservatively. In patients in the late group who underwent the lap-WT, the mean operating time (171 vs. 205 min, p = 0.001) and mean estimated blood loss (232.1 vs. 370.0 ml, p = 0.017) were significantly less than the early group cases who received lap-WT.A lap-WT is a safe treatment strategy in select cases when used as a way of preserving the spleen. When splenic vessel preservation is technically challenging, for example when the tumor is enlarged or is attached to the splenic vessels, planned lap-WT or early conversion to lap-WT may be a feasible option.
The connecting rod is one of the most important parts of an engine system. It fits in between the crosshead and the crankshaft and converts the piston’s reciprocating motion to rotary motion with the crankshaft. The connecting rod is subjected to a complex state of loading. High compressive loads and high tensile loads are due to combustion and connecting rod’s mass of inertia, respectively. This is why the connecting rod is the most stressed part of an engine system. If the engine is operating, connecting rod fails, this could cause a critical situation. Therefore, the connecting rod should be able to withstand tremendous load and transmit a great deal of power smoothly. In general, the failure occurs at the big end of connecting rod. Hence, the connecting rod’s big end corner radius was taken as a design variable. Also, three dimensional finite element analyses were performed. From these results, the stress distribution was estimated and the value of the corner radius was optimized.
Immunoglobulin (Ig) G4-related sclerosing disease is a newly defined clinicopathological entity characterized by lymphoplasmacytic infiltration of IgG4-positive plasma cells and varying degrees of fibrosis within affected tissues. Patients usually exhibit multisystem involvement and often respond well to steroid and immunosuppressive therapy. This report presents a case of IgG4-related sclerosing disease involving the ureter and kidney. We hope to bring IgG4-related sclerosing disease to the attention of urologists, because it is an uncommon disease that commonly responds to systemic corticosteroids.