• Membrane and Water Treatment
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• v.9 no.6
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• pp.385-392
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• 2018

Poly vinyl chloride (PVC) was chemically modified, and used for ultrafiltration to analyze the performance. Non-solvent induced phase separation (NIPS) method was used to prepare membranes. The neat PVC membrane was casted and used as a control membrane. Modified membrane was prepared by reacting PVC with ethanolamine (EA) in the casting solution (labeled as CM-PVC). Pure water permeability (PWP) was evaluated by measuring pure water flux. Humic acid was used as model foulant solute to analyze flux and rejection ability of membranes. Flux and rejection data of neat and modified membranes were compared to prove the improvement in the filtration performance. The experimental results showed that for PVC and CM-PVC, PWP was calculated to be ~64 and ${\sim}143L/m^2{\cdot}h$, respectively, and the rejection of humic acid was found to be 98% and 100%, respectively. TGA was carried out to analyze the effect of chemical modification on the thermal stability of polymer. FT-IR analysis was another characterization technique used for the comparative study.

• KSBB Journal
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• v.21 no.5
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• pp.401-404
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• 2006

Macroporous Poly(Methacrylic acid-co-Ethylene Glycol Dimethacrylate) Rods were in situ thermal initialized within a empty column($3.9{\times}150mm$) by free radical polymerization. The polymerization mixture was consisted of monomer, cross-linking monomer, porogenic solvent, initiator and control the ratio of these materials, column efficiency could be developed. Caffeine and tryptophan as separation substances and the retention mechanism of this kind of monolithic column was mainly hydrogen bond function.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.171-178
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• 2015

3GPP long-term evolution(LTE) band 2.3~2.4 GHz is adjacent to 2.4~2.5 GHz band for WLAN, and therefore compatibility study of the two systems is desirable. We propose a dynamic system simulation methodology to investigate the effect of WLAN interference on LTE systems. As capturing space/time/frequency changes in system parameters, the dynamic system simulation can exactly predict real system performance. Using the proposed methodology, we obtain LTE downlink throughput loss for the frequency separation between the two systems. Throughput loss under 1 % is obtained from guard band over 11 MHz(single channel allocation) or 10 MHz(three channel allocation).

• Clinics in Shoulder and Elbow
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• v.5 no.2
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• pp.73-80
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• 2002

Purpose: Weight lifting is a good training to control body weight, to correct body shape and to relieve stress. How-ever if the training is continued by inadequate training method and technique, the risks of the shoulder injuries are relatively high. Main Subject: The rotator cuff injury is the most common disorder to wright lifters and often results from the train- ing program of upright row, military press and pectoral deck. The chances of subacromial impingement in these postures are high because the shoulder rotates under the acromion at 90 abduction state. Shoulder instability in weight lifters can develop due to various causes. aepeated microtrauma and excessive abduction and external rotation may result in laxity of the anterior capsular structure, ligament and muscles. Behind the neck and bench press are high risk training postures. Other than those injuries, idiopathic osteolysis of distal clavicle, acromioclavicular separation, pectoralis major muscle rupture, and triceps muscle rupture nay develop. Conclusion: The best treatment option of the shoulder injury to weight lifters is to eliminate the possible risk elements for the weight lifters in training program and to provide proper and prompt treatment as soon as possible.

• Analytical Science and Technology
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• v.11 no.2
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• pp.96-104
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• 1998

A photodiode array multichannel detector system for capillary electrophoresis was developed. The photodiode array detector for capillary electrophoresis (CE-PDA) has 1024 photodetectors and can analyze sample by measuring UV/VIS absorption spectrum in 275~675 nm wavelength range. The CE-PDA instrument can get a spectrum in 30 ms during sample separation and can be programmed by a PC to control various experimental conditions required for sample analysis. The performance of the multichannel CE-PDA instrument was tested using L-ascorbic acid and alizarin yellow GG mixture. The reproducibility test of the CE-PDA system showed 5.6% RSD.

• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.117-124
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• 1997

A simple, rapid and simultaneous analytical method is described for the detection of Sulfonamide and Tetracycline residues, i.e., Sulfamerazine (SMR), Sulfamethazine (SMT), Sulfamonomethoxine (SMM), Sulfadimethoxine (SDM), Sulfaquinoxaline (SQN), Oxytetracycline (OXY), Tetracycline (TC), Chlortetracycline (CTC). Blank control and sulfonamide and tetracycline fortified fish muscle samples (0.5 f) were blended with octadecylsilyl (C18, 40 ${\mu}{\textrm}{m}$, 21% load, 60$\AA$) derivatized silica packing material (2 g). Blended fish samples were washed with hexane, then, benzene and dichloromethace were used for the elution of tetracycline and sulfonamide were analyzed by HPLC. Correlation coefficients of standard curves for individual sulfonamide and tetracycline isolated from fortified samples were linear (0.9993$\pm$0.0003~0.9997$\pm$0.0003, 0.9493$\pm$0.078~0.9753$\pm$0.036), respectively. The average percentage recoveries of sulfonamide and tetracycline ranged as 80.86~96.52% to 85.88~92.23%, and 30.01~37.12% to 65.89~73.40%, for the concentration range (0.1~1.0 ppm) examined, respectively. Limit of detection for sulfonamide was 0.0012 ppm for SMR in Paralichthys Olivacleus and 0.0020 ppm for SMR, 0.015 ppm for SMM in Cyprinus Carpio. The applicability of this procedure is demonstrated by separation and detection of incurred tetracycline and sulfonamide residues in fish muscle tissue.

• Biomolecules & Therapeutics
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• v.13 no.2
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• pp.90-94
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• 2005

Prazosin hydrochloride is an antihypertensive drug with selective ${\alpha}_1$-adrenoreceptor blocking effects. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of prazosin in human plasma. A reversed-phase C18 column was used for the separation of prazosin and terazosin (internal standard) with a mobile phase composed of water, acetonitrile and triethylamine(75:25:0.1, V/V;pH5.0) at a flow rate of 1.5 ml/min. the fluorescence detector was set at excitation and emissionwavelengths of 250 and 370 nm, respectively. Intra-and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 0.5 ng/ml. Good recovery (>80%) was seen in plasma. Prazosin was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of a single 2-mg dose as prazosin base to 16 healthy volunteers. The maximum plasma concentration of prazosin was 23.1 ${\pm}$ 16.5 ng/ml at 2.1 h, and the mean area under the curve and elimination half-life were calculated to be 108.4 ${\pm}$ 74.2 ng ${\cdot}$hr/ml and 2.5 ${\pm}$ 0.6 h, respectively.

• Natural Product Sciences
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• v.16 no.4
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• pp.251-258
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• 2010

In this study, quantitative analysis for the quality evaluation of Salviae Miltiorrhizae Radix using HPLC/UV was developed. For quantitative analysis, six major bioactive compounds were determined. The separation conditions employed for HPLC/UV were optimized using ODS $C_{18}$ column ($250{\times}4.6\;mm$, $5\;{\mu}m$) with gradient condition of A (1% formic acid in $H_2O$) and B (acetonitrile : methanol : formic acid = 100 : 75 : 1) as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 280 nm. These methods were fully validated with respect to the linearity, accuracy, precision and recovery. The HPLC/UV method was applied successfully to the quantification of six major compounds in the Salviae Miltiorrhizae Radix. The results indicate that the established HPLC/UV method is suitable for the quantitative analysis.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.4
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• pp.124-131
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• 2003

When a secondary gaseous flow is injected vertically into a supersonic flow through circular nozzle, a complicated structure of flow field is produced around the injection area. The interaction between the two streams produces a strong bow shock wane on the upstream side of the side-jet. The results show that bow shock wave and turbulent boundary layer interaction induces the boundary layer separation in front of the side-jet. This study is to analyze the structure of flow fields and distribution of surface pressure on the flat plate according to total pressure ratio using a supersonic cold-flow system and also to study the control force of affected side-jet. The nozzle of main flow was designed to have Mach 2.88 at the exit. The injector has a sonic nozzle with 4mm diameter at the exit of the side-jet. In experiments, The oil flow visualization using a silicone oil and ink was conducted in order to analyze the structure of flow fields around the side-jet. The flow fields are visualized using the schlieren method. In this study, a computational fluid dynamic solution is also compared with experimental results.

• Health Policy and Management
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• v.4 no.2
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• pp.111-125
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• 1994

In developing total hospital information system, large amount of time and expense are to be spent while its results are likely to lead itself to end-users' dissatisfaction. Some of the main complaints on the part of end-users come from insufficient consideration of end-users environment as well as inappropriate representation of their requirement in the system alalysis and design. This papre addresses some advantages of Essential Logical Modeling Process for better analysis and design, explaining by example the developmental process of the Patent Management and Accounting System for a tertiary care hospital. In the case, the Essential Model, suggested by McMenamin and Palmer, proved to be an effective tool for clear separation of analysis and design phase and for better communication among system developers and with end-users. The modeling process itself contributed to better program modularity as well, shown in a Structured Chart. Difficulties in learning how to identify' essential activities' for the modeling practice were experienced in the beginnins stage, which were, however, overcome by elaborating some heuristic guideling and by rdferring to necessary tools including State Transition Diagram, Control Flow Diagram, and so many. While full evaluation of the Essential Model usag remains to wait till the completion of the case project, its strengt in making clear distinction between analysis and design phase was enough to be attractive to system analysts. The model concepts are open to many further application fields, particularly such areas as business re engineering, process remodeling, office automation, and organizational restructuring.