• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.2
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• pp.97-103
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• 2010

The four combustion stages in a diesel engine have close correlation among them. Especially, the ignition delay period has significant effect on the following combustion stage. And the period is also one of inevitable combustion processes in the diesel engine. For example, the diesel knocking is a well-known phenomenon due to the long ignition delay period. The interval of the ignition delay period is affected by the mixture formation process in the cylinder. However, in the case of the D.I. diesel engine, the available duration to make the mixture formation of air-fuel is very short. In addition, the means of the mixture formation mainly depends on the injection characteristics and properties of the fuel. It is difficult to make complete mixture. Therefore, an early stage of combustion is violent, which leads to the weakness of noise and vibration. In this study, using the visible engine, we measured the ignition delay period by photo sensor which detect occurrence of flame and presented the factors of the injection characteristics such as kinds of injection system, the injection pressure and the injection timing. The relation between the ignition delay period and cylinder pressure diagram which was concurrently obtained was also estimated.

• Journal of Veterinary Clinics
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• v.8 no.1
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• pp.11-26
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• 1991

The effects of intra-articula. sodium hyaluronate(SH) and polysulfated glycosaminoglycan(PSGAG) on degenerative joint disease of the carpus were compared each other In 20 racehorses. Ten horses were dosed with intra-articula. injection of 20mg SH(2 times/2 weeks interval) and ten horses were dosed with intra-articular injection of 250mg of PSGAG(4 times/1 week into.val). Synovial fluid analysis and clinical examination were made to evaluate the effects of the drugs on degenerative joint disease at before injection and 2 weeks after the last injection, respectively. Appearance and mucinous precipitate quality oi synovial fluids of the group injected with 58 and PSGAG were improved by 40～50% and 60～80%, respectively. The chemical values of alkaline phosphatase, lactic dehydrogenase, aspartate aminotransferase, total protein, A/G ratio and glucose of synovial fluid in the group injected with PSGAG were more clearly returned to the normal values than those of the group injected with SH. Relative viscosity and total white blood cells of synovial fluid were returned to the normal walues after the treatments in both groups. Clinical symptoms(swelling, heat and pain on carpal joint, and lameness) of the horses in the group injected with SH and PSGAG were disappeard by 56～67% and 67～80%, respectivelty. Conclusively, the PSGAG was superior to SH in the effects on treatment of the degenerative joint disease in the horses.

• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.61-64
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• 1995

The present study was conducted to examine the effect of recombinant bovine somatotrpin(${\gamma}$BST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided cows were divided into two groups: 1) control cows received neither ${\gamma}$bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500 mg ${\gamma}$bST each cow byj after lst injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after lst injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection). Milk bST concentration was measured by the radioimmunoassay method. There was no statistical difference(p<0.05) in milk bST levels between two groups showing bST levels in the range of 1.8 ng/m/ to 3.1 ng/m/. That is, ${\gamma}$bST administration did not increase bST levels in milk.

• The Korean Journal of Pain
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• v.23 no.4
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• pp.254-257
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• 2010

Background: Epidural steroid injection is an established treatment modality for intervertebral disc prolapse to radiculopathy. In cases where two levels of radiculopathy are present, two separate injections are warranted. Herein, we present our experience of management of such cases with a single epidural injection of local anaesthetic, tramadol and methylprednisolone, and table tilt for management of both radiculopathies. Methods: 50 patients of either sex aged between 35-65 years presenting with features of cervical and lumbar radiculopathic pain were included and were subjected to single lumbar epidural injection of local anaesthetic, tramadol and methylprednisolone, in the lateral position. The table was then tilted in the trendelberg position with a tilt of 25 degrees, and patients were maintained for 10 minuted before being turned supine. All patients were administered 3 such injections with an interval of 2 weeks between subsequent injections, and pain relief was assessed with a visual analogue scale. Immediate complications after the block were assessed. Results: Immediate and post procedural complications observed were nausea and vomiting (20%), painful injection site (4%), hypotension (10%) and high block (4%). Pain relief was assessed after the three injections by three grades: 37 (74%) had complete resolution of symptoms; 18% had partial relief and 8% did not benefit from the procedure. Conclusions: This technique may be used as an alternative technique for pain relief in patients with unilateral cervical and lumbar radiculopathies.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.28-36
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• 2000

Spray characteristics of diesel fuel injection is one of the most important factors in diesel combustion and pollutant emissions especially in HSDI (High Speed Direct Injection) diesel engines where the interval between the onset of combustion and the evaporation of atomized fuel is relatively short, An investigation into various spray characteristics from different holes of VCO(Valve Covered Orifice) nozzles was performed and its results were compared to standard sac nozzle. The global characteristics of spray, including spray angle, spray tip penetration, and spray pattern were measured from the spray images which were frozen by an instantaneous photography with a spark light source. For better understanding of spray behavior, SMD of the fuel sprays from multi hole nozzles were measured with back light imaging while the sprays from the other holes are covered by a purpose-built nozzle cap. The investigation manifestly reveals the different spray patterns at the beginning of injection produced by VCO nozzles can be identified as three distinct types with their own macroscopic and microscopic characteristics, while macroscopic non-uniformity disappears at 0.9∼1.0ms from the start of injection.

• Journal of ILASS-Korea
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• v.5 no.4
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• pp.33-39
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• 2000

The behavior of the 2-stage spray was studied by using the schlieren method with the high pressure common-rail injection system. The spray injected 2 times with the interval of $0.3ms{\sim}1.5ms$ between the 1st and the 2nd spray in a modeled combustion chamber of constant volume bomb. In this case, the quantity of injected fuel of 1st and 2nd also changed. The schlieren photograph shows that the 2nd spray goes further away than the 1st spray when the quantity of the 1st spray is less than that of the 2nd spray. The dispersion of the vapour to the combustion chamber is not affect in a 10% of 1st spray quantity. When the 1st spray quantity is more than the 2nd spray, the vapour scattering of spray is good.

• Journal of Power System Engineering
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• v.6 no.2
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• pp.54-59
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• 2002

The principle of the FDM(fused deposition modeling) process is based on the layer by layer manufacturing technology, like other RP(rapid prototyping) process. In the FDM process, each layer may have different shape. Therefore, the built model may have stairs shape on its surface. This stairs shape is one of the serious problems in the FDM process. Thus in this study, cube models and spherical models were fabricated by FDM process to investigate the influence of injection amount on surface roughness. Models with various road width were also built to investigate the influence of road width on surface roughness. Surface roughness of the models was measured and analyzed. The result obtained in this study are expected to help selecting the part build orientation for optimum surface roughness.

• Journal of Drive and Control
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• v.13 no.2
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• pp.51-58
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• 2016

The present study deals with the issue of clamping force control of an injection molding machine using 2-way cartridge valve based logic circuit. The operating principle for the cartridge valve is described with its construction and static opening behavior. Basic module circuits are designed first and analysed according to the basic functions. Then they are combined with a virtual design model for the clamping mechanism to simulate the control performance of the overall system. The backlash inherent in the mechanism is considered while evaluating the time-delay in the process of clamping force build-up. The effects of a couple of design parameters in backlash, i.e., interval and stiffness have been demonstrated in the time-domain.

• Journal of Veterinary Clinics
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• v.16 no.1
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• pp.155-162
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• 1999

This study was performed to assess that clinco-therapeutic effect of natural Italian honeybee (Apis mellifera) venom in adjuvant-induced arthritic rat. Ninety Sprague- Dawley rats of male were injected with complete Freund's adjuvant (CFA). Adjuvant arthritis was produced by a single subcutaneous injection of 1 mg Mycobacterium butyricum suspended in 0.1 ml paraffin oil into the right hindpaw. Righting reflex was uniformly lost and considered to be the point of arthritis development on day 14 after CFA injection. Experimental groups were divided into three groups. When arthritis was developed in the rat hind-paw, tested groups were administrated with prednisolone (10 mg/kg, p.o) and honeybee venom (one bee, s.c) at an interval of two days. Control group was subcutaneously injected with 0.1 ml of physiological saline solution in the rat at an interval of two days. Clinical findings, hematological values and histopathological findings were observed during or after the drugs administration. In tested groups, the development of inflammatory edema and polyarthritis on day 14 after treatment was suppressed. No significant differences of hindpaw edema volume and lameness score between prednisolone and honeybee venom groups were observed during or after therapeutic drugs treatment. WBC counts of prednisolone and honeybee venom treatment groups as compared with the control group were getting remarkably decreased during or after the therapeutic drugs administration(p＜0.01). Erosions of articular cartilage and inflammatory cell infiltrations during or after the therapeutic drugs treatment was effectively suppressed in natural honey venom.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.117-122
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• 2013

This study is aimed to develop LNT(Lean NOx Trap) aftertreatment system for DME engine. Modified DME engine, which was changed from diesel to current DME engine, is used for this research and is equipped with common rail type injector and fuel supplying system. LNT system has reductant injector. DME is also used as reduction agent. For this research, reduction agent injection time width and interval were varied. And also, swirler was used to improve homogeneity of reducing agent in exhaust pipe. The reduction rate of NOx by LNT was increased by longer injection width, short interval and swirler. The maximum diminution of NOx by LNT was over 85%.