• Design & Manufacturing
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• v.2 no.1
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• pp.39-43
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• 2008

There occur not only many problems in the injection process but also low quality productivity due to the injection conditions of various injection factors. Injection molding process factors such as molding temperature, injection pressure, flow rate and flow velocity, must be controlled properly in filling and packing phases in the injection molding process. In this study, effects of these factors on the injection molding were investigated through the flow analysis for the holding pressure affecting cooling time. Results of this study would be helpful to setting of holding pressure for optimization of forming condition in order to reduce cooling time in injection molding.

• The Korean Journal of Pain
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• v.28 no.2
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• pp.122-128
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• 2015

Background: Caudal epidural injections have been commonly performed in patients with low back pain and radiculopathy. Although caudal injection has generally been accepted as a safe procedure, serious complications such as inadvertent intravascular injection and dural puncture can occur. The present prospective study was designed to investigate the influence of the depth of the inserted needle on the success rate of caudal epidural blocks. Methods: A total of 49 adults scheduled to receive caudal epidural injections were randomly divided into 2 groups: Group 1 to receive the caudal injection through a conventional method, i.e., caudal injection after advancement of the needle 1 cm into the sacral canal (n = 25), and Group 2 to receive the injection through a new method, i.e., injection right after penetrating the sacrococcygeal ligament (n = 24). Ultrasound was used to identify the sacral hiatus and to achieve accurate needle placement according to the allocated groups. Contrast dyed fluoroscopy was obtained to evaluate the epidural spread of injected materials and to monitor the possible complications. Results: The success rates of the caudal injections were 68.0% in Group 1 and 95.8% in Group 2 (P = 0.023). The incidences of intravascular injections were 24.0% in Group 1 and 0% in Group 2 (P = 0.022). No intrathecal injection was found in either of the two groups. Conclusions: The new caudal epidural injection technique tested in this study is a reliable alternative, with a higher success rate and lower risk of accidental intravascular injection than the conventional technique.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.104-109
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• 2011

The removal efficiencies of 2-methylisoborneol (MIB) and geosmin were investigated to reveal removal characteristics of typical organic compounds causing disagreeable taste and odor at the conventional water treatment plant installed with pulsator clarifier patented by the French company $Degr{\acute{e}}mont$. The injection rate of Powdered Activated Carbon (PAC) into water was changed step wisely as we conducted jar tests in the laboratory and water treatment in the actual plant. 2-MIB concentration decreased linearly while geosmin did exponentially along with the injection rate of PAC at our jar tests. The removal efficiency of geosmin by PAC injection was considerably higher than that of 2-MIB. In the real pulsator clarifier, 2-MIB concentration started decreasing as the injection rate reached up to 10 mg/L of PAC. On the other hand, the concentration of geosmin in water decreased proportional to the injection rate of PAC. In the sand filtration, removal efficiencies of 2-MIB and geosmin on July were much higher than those on March. It was carefully suggested beforehand and found afterwards that general microorganisms notably existed in the sand filter with no chlorine in filter influent and backwash water and the sand filter biologically activated removed much more odor compounds. It was considered as the reason why the removal efficiency of 2-MIB and geosmin was increased. The microbial activity maybe increased in summer with water temperature rising and low filtration rate possibly increased contact time between odor compounds and general microorganisms.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.36.3-37
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• 2009

This is an attempt to improve a formula to predict variations of geomagnetic storm indices (Dst) from solar wind parameters. A formula which is most widely accepted was given by Burton et al. (1975) over 30 years ago. Their formula is: dDst*/dt = Q(t) - Dst*(t)/$\tau$, where Q(t) is the Dst injection rate given by the convolution of dawn-to-dusk electric field generated by southward solar wind magnetic field and some response function. However, they did not clearly specify the response function. As a result, misunderstanding seems to be prevailing that the injection rate is proportional to the dawn-to-dusk electric field. In this study we tried to determine the response function by examining 12 intense geomagnetic storms with minimum Dst < -200 nT for which solar wind data are available. The method is as follows. First we assume the form of response function that is specified by several time constants, so that we can calculate the injection rate Q1(t) from the solar wind data. On the other hand, Burton et al. expression provide the observed injection rate Q2(t) = dDst*/dt + Dst*(t)/$\tau$. Thus, it is possible to determine the time constants of response function by a least-squares method to minimize the difference between Q1(t) and Q2(t). We have found this simple method successful enough to reproduce the observed Dst variations from the corresponding solar wind data. The present result provides a scheme to predict the development of Dst 30 minutes to 1 hour in advance by using the real time solar wind data from the ACE spacecraft.

• Korean Journal of Agricultural Science
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• v.34 no.1
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• pp.37-46
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• 2007

This study was conducted to investigate the antler induction rate and production by artificial induction of antlerogenesis using $CaCl_2$ injection on both periosteum around area of horn development for the frontal bone of a female elk deer which do not have an antler. The results obtained from eleven deers for verifying effect of the female's antler induction on reproduction are as follows: The antler development induction by $CaCl_2$injection is higher on the treatments of 30 and 50% of $CaCl_2$ injection than those on the treatments of 15 %. The antler production is higher on the 30 % $CaCl_2$ injection than those of 15 and 50 % $CaCl_2$ injection. For 30 % $CaCl_2$ injection, the antler production is higher in 1.5 and 2.0 ml of % $CaCl_2$ injection than the other injection level. After the induction of antler development, the birth rate is not changed as of 75~100 %, while the regeneration rate of the antler which was not constant in approximately 45 % for five among eleven female deer. With these results, we assume that the injection concentration and amount of $CaCl_2$ injection are around 30 % and 1.5 and 2.0 ml level which can be not only most effective conditions for the antler induction rate and production, but also these conditions do not influence the reproduction during the period of the female elk's antler development induction.

• Journal of Acupuncture Research
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• v.27 no.1
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• pp.65-74
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• 2010

Objectives : This study was to investigate the effects of Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi Pharmacopuncture on autonomic nervous system with Heart Rate Variability(HRV). Purpose of the trial was to observe what influence Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi pharmacopuncture have on the autonomic nervous system. Methods : 40 healthy male volunteers were divided into two experimental groups, such as Cervi Pantotrichum Cornu Pharmacopuncture group and Bovis calculus Fel Ursi Pharmacopuncture group. Study design was a randomized, double-blind clinical trial. 20 subjects in one experimental group were injected Cervi Pantotrichum Cornu Pharmacopuncture, 20 subjects in other experimental group were injected hydrolyzed Bovis calculus Fel Ursi Pharmacopuncture at GB21(Kyonjong). We measured HRV 7 times : baseline measurement and every 5 minutes for 30 minutes after injection. The SPSS 15.0 for Windows was used to analyze the data by the paired t-test(in group) and independent sample t-test(between the groups). Results A. Time Domain Analysis 1. Analysis of Mean HRV, SDNN and Complexity After injection of Cervi Pantotrichum Cornu Pharmacopuncture, Mean HRV was significantly decreased all the times after injection. SDNN was significantly increased at immediate and 25 minute after injection. Complexity was significantly decreased only at 15 minute after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, Mean HRV was significantly decreased all the times after injection. Complexity was significantly decreased at 15 minutes after injection. 2. Analysis of HRV index, pNN50 After injection of Cervi Pantotrichum Cornu Pharmacopuncture, HRV index was significantly increased immediately after injection. pNN50 was significantly decreased at immediately, 20 and 25 minutes after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, HRV index was significantly increased immediately after injection. pNN50 was significantly decreased at immediate and 25 minutes after injection. B. Frequency Domain Analysis 1. Analysis of Ln(TP), Ln(HF), Ln(LF), Ln(VLF) After injection of Cervi Pantotrichum Cornu Pharmacopuncture, Ln(TP) was significantly increased at immediate and 25 after injection. Ln(HF) was significantly increased all the times after injection. Ln(LF) was significantly increased at 15, 20 and 25 minutes after injection. Ln(VLF) was significantly increased at immediate and 25 minutes after injection. After injection of Bovis calculus Fel Ursi Pharmacopuncture, Ln(TP) was significantly increased at immediately and 25 after injection. Ln(LF) was significantly increased at 20 and 25 minutes after injection. Ln(VLF) was significantly increased at immediate and 25 minutes after injection. Conclusions : We results suggest that Cervi Pantotrichum Cornu Pharmacopuncture and Bovis calculus Fel Ursi Pharmacopuncture in healthy adult men tend to activate the autonomic nervous system and sympathetic nervous system within normal range.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.89-97
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• 2017

Butanol has an ability to improve the ignition quality due to its lower latent heat of vaporization; it has an advantage to reduce a volume of a fuel tank because its energy density is higher than that of ethanol. Also, butanol-diesel oil blending quality is good because butanol has an effect to prevent the phase-separation between two fuels. Even if the blended oil contains water, it can reduce the corrosion of the fuel line. Thus, it is possible to use butanol-diesel oil blended fuel in diesel engine without modification, and it may reduce the environment pollution due to NOx and particulate and the consumption of diesel oil. Therefore, some studies are being advanced whether butanol is adequate as an alternative fuel for diesel engines, and the results of the combustion and exhaust gas emission characteristics are being presented. Though the injection and spray characteristics of butanol are more important in diesel combustion, the has not yet dealt with the matter. In this study, the influence in which differences of physical properties between butanol and diesel oil may affect the injection and spray characteristics such as injection rate, penetration, spray cone angle, spray velocity and process of spray development were examined by using CRDI system, injection rate measuring device and spray visualization system. The results exhibited that the injection and macroscopic spray characteristics of two fuels were nearly the same.

• Journal of Veterinary Clinics
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• v.34 no.5
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• pp.330-334
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• 2017

The aim of this study was to establish an injection protocol of a test bolus and a main bolus of contrast material for computed tomographic pulmonary angiography (CTPA) for visualizing optimal pulmonary arteries in normal beagle dogs. CTPA using a test bolus method from either protocol A or B were performed in each of four normal beagle dogs. In protocol A, CTPA was conducted with a scan duration for around 8 s, setting the contrast enhancement peak of the pulmonary trunk in the middle of the scan duration. The arrival time to the contrast enhancement peak was predicted from a previous dynamic scan using a test bolus (150 mg iodine/kg) injected with the same injection duration using for a main bolus (450 mg iodine/kg). In protocol B, CTPA was started at the predicted appearance time of contrast material in the pulmonary trunk based on a previous dynamic scan using a test bolus injected with the same injection rate as a main bolus. CTPA using protocol A showed the optimal opacification of the pulmonary artery with pulmonary venous contamination. Proper CTPA images in the absence of venous contamination were obtained in protocol B. CTPA with a scan duration for 8 s should be started at the appearance time of contrast enhancement in the pulmonary trunk, which can be identified exactly when a test bolus is injected at the same injection rate used for the main bolus.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.5
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• pp.19-24
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• 2004

Entrainment of ambient gas into a transient diesel spray is a crucial factor affecting the following preparation of combustible mixture. In this study, the entrainment characteristics of ambient gas for a non-evaporating transient diesel were investigated using a common-rail injection system. The effects of ambient gas density and nozzle hole geometry were assessed with entrainment coefficient. Laser Doppler Velocimetry (LDV) technique was introduced to measure the entrainment speed of ambient gas into a spray. There appeared a region where the entrainment coefficients remained almost constant while injection rates were still changing. The effect of common-rail pressure, which altered the slope of injection rate curve, was hardly noticed at this region. Entrainment coefficient increased with ambient gas density, that is, the effect of ambient gas density was greater than that of turbulent jet whose entrainment coefficient remained constant. The non-dimensional distance was defined to reflect the effect of nozzle hole diameter and ambient gas density together. The mean value of entrainment coefficient was found to increase with non-dimensional distance from the nozzle tip, which would be suggested as the guideline for the nozzle design.

• Resources Recycling
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• v.9 no.6
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• pp.23-30
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• 2000

Since most of the waste plastics are incinerated and landfilled for the plastic treatment, the environmental friendly processes must be introduced. The plastic utilization of plastic to the blast furnace as a substitutional fuel was developed as a useful recycling method of waste plastics, and commercialized in several ironmaking company in Europe and Japan. Present study was carried out to understand the effect of plastic injection on blast furnace process continuously by using the foundry blast furnace in POSCO. The coke replacement ratio turned out to be 0.98 with the waste plastic injection up to 13.8 kg/thm of injection rate, and there were no significant effect of the kinds of injection plastics on the replacement ratio in this test operation. The permeability in the furnace became worse and the heat load in the lower part of blast furnace was increased with increasing the injection rate of waste plastics. As the rate of plastic injection were increased, the top gas utilization and shaft efficiency were also decreased from the Rist diagram analysis.