• Journal of Korean Society of Environmental Engineers
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• v.32 no.8
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• pp.739-746
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• 2010

The purposes of this study are 1) to develop an advanced chamber system within ${\pm}10%$ of air velocity at the particulate matter (PM) collection area, 2) to research theoretical characteristics of PM10 and PM2.5 samplers, 3) to assess the performance characteristics of PM10 and PM2.5 samplers through chamber experiments. The total six one-hour experiments were conducted using the cornstarch with an mass median aerodynamic diameter (MMAD) of $20\;{\mu}m$ and an geometric standard deviation of 2.0 at the two different air velocity conditions of 0.67 m/s and 2.15 m/s in the chamber. The aerosol samplers used in the present study are one APM PM10 and one PM2.5 samplers accordance with the US federal reference methods and specially designed three mini-volume aerosol samplers (two for PM10 and one for PM2.5). The overall results indicate that PM10 and PM2.5 mini-volume samplers need correction factors of 0.25 and 0.39 respectively when APM PM samplers considered as reference samplers and there is significant difference between two mini-volume aerosol samplers when a two-way analysis of variance is tested using the measured PM10 mass concentrations. The PM10 and PM2.5 samplers with the cutpoints and slopes (PM10: $10{\pm}0.5\;{\mu}m$ and $1.5{\pm}0.1$, PM2.5: $2.5{\pm}0.2\;{\mu}m$ and $1.3{\pm}0.03$) theoretically collect the ranges of 86~114% and 64~152% considering the cornstarch characteristics used in this research. Furthermore, the calculated mass concentrations of PM samplers are higher than the ideal mass concentrations when the airborne MMADs for the cornstarch used are smaller than the cutpoints of PM samplers and the PM samplers collected less PM in another case. The chamber experiment also showed that PM10 and PM2.5 samplers had the bigger collection ranges of 37~158% and 55~149% than the theocratical calculated mass concentration ranges and the relatively similar mass concentration ranges were measured at the air velocity of 2.15 m/s comparing with the 0.67 m/s.

• Journal of Dairy Science and Biotechnology
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• v.29 no.2
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• pp.25-35
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• 2011

The objectives of this study were to evaluate the sensory characteristic quality of commercial milk brands selling in the market under the preservation at the temperature of $7^{\circ}C$ and $10^{\circ}C$ stored during the period of shelf-life. Quantitative descriptive analysis after developing of descriptive terms and cluster characterization by PCA analysis over a total of 128 LTLT, HTST, UHT and UHT-ESL milks, were conducted by 8 trained panelists. A total of fourteen attributes; three aroma attributes (grassy, milky, cultured milk aroma) and seven flavor/taste attributes (sweet, salty, sour, milk, cooked, cheesy, paper board) and one aftertaste attributes (rancid flavor) and one texture attributes (viscous), were developed as descriptive terms. Significant differences (P<0.01) in the sensory attributes; sweet, milky, cheesy etc. in UHT milk and sour, cheesy, paper board, rancid etc. in UHT-ESL milk were also found between the two different temperatures within the shelf life, but both type of pasteurized milk samples (LTLT and HTST) showed significant differences (P<0.01) in the attributes, such as cultured milk aroma, salty, sour, cheesy, rancid in LTLT milk and grassy, milky, salty in HTST milk and difference (P<0.05) in cultured milk aroma for HTST milk. Therefore, from the viewpoint of not only hygienic quality but also sensory characteristics, it is required for the better acceptance of milk consumers to amendment on the regulation in relation to the preservation standard of pasteurized milk as well as UHT milk to lower than $7^{\circ}C$.

• Analytical Science and Technology
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• v.25 no.2
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• pp.121-126
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• 2012

It is essential to evaluate the quality of Hanji record paper without damaging the record paper by previous destructive methods. The samples were Hanji record paper produced in the 1900s. Near-infrared (NIR) spectrometer was used as a non destructive method for evaluating the quality of record papers. Fourier transform (FT) spectrometer was used with 12,500 to 4,000 $cm^{-1}$ wavenumber range for quantitative analysis and it has high accuracy and good signal-to-noise ratio. The acidity and moisture content of Hanji record paper were measured by integrating sphere as diffuse reflectance type. The acidity (pH) of chemical factors as a quality evaluated factor of Hanji was correlated to NIR spectrum. The NIR spectrum was pretreated to obtain the coefficients of optimum correlation. Multiplicative scatter correction (MSC) and First derivative of Savitzky-Golay were used as pretreated methods. The coefficients of optimum correlation were calculated by PLSR (partial least square regression). The correlation coefficients ($R^2$) of acidity had 0.92 on NIR spectra without pretreatment. Also the standard error of prediction (SEP) of pH was 0.24. And then the NIR spectra with pretreatment would have better correlation coefficient ($R^2$ = 0.98) and 0.19 as SEP on pH. For moisture contents, the linearity correlation without pretreatment was higher than the case with pretreatment (MSC, $1^{st}$ derivative). As the best result, the $R^2$ was 0.99 and SEP was 0.45. This indicates that it is highly proper to evaluate the quality of Hanji record papers speedily with integrated sphere and FT NIR analyzer as a non-destructive method.

• Analytical Science and Technology
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• v.26 no.3
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• pp.165-173
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• 2013

To establishment of PT Program for Indoor air quality field that manufacture of confidential development PTMs (proficiency testing materials) and examined of proficiency testing evaluation included sampling process whether or not that is valid. Confirmation of homogeneity and stability of PTMs prepared. PTMs were confirmed to be homogeneous enough to be used as proficiency testing materials since withinbottle homogeneities of the RMs were lower than 0.3 times of targeted standard deviation of proficiency testing. The result of this study showed that the Robust RSD of proficiency testing for VOCs (volatile organic compounds) appeared 23~43% in concentration of 50~320 ${\mu}g/m^3$ for Method A(Distribution by adsorption in Tenax-tube of VOCs), but less 13~42% in concentration of 200~1200 ${\mu}g/m^3$, 16~31% in concentration of 100~450 ${\mu}g/m^3$ for Method B (distribution by VOCs of gas phase in 10L Tedalr bag), C (directly sampling of cylinder with high pressure) respectively. The result of this study showed that method C with sampling is most adequate to the proficiency testing for VOCs in indoor air.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.105-110
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• 2005

Background/Aim : Common bile duct (CBD) stones may cause jaundice, cholangitis, or pancreatitis. Extracorporeal shock wave lithotripsy (ESWL) may be needed whenever endoscopic procedure are failed to extract common bile duct stones. The aim of this study is to provide the standard for patient's best choice on ESWL for treatment of CBD stones resistant to endoscopic extraction. Materials and Methods : Fourty-six patients failed in endoscopic stone extraction including mechanical lithotripsy were treated by ESWL. In all patients, endoscopic sphincterotomy and nasobiliary drainage tube was done before ESWL using the ultrasonography for stone localization with a spark-gap type lithotriptor. Patients were sedated with an intravenous injection of 50 mg of Demerol. None were treated under general anesthesia. Results : Overall complete clearance rate of CBD stone was 89.1% (41/46). In 82.6% of the patients, the stones were extracted endoscopically after ESWL, and spontaneous passage was observed in 6.5%. In the clearance rate after ESWL, there were no noticeable differences with regard to number (single: 82.8%, two or three: 100%, more than three: 100%) and size of the stone (less than 33mm: 92.9%, 33 mm or larger: 83.3%), whereas there were significant differences with regard to the ratio of sum of long-axis length of the all stones to sum of long-axis length of the CBD excluding stone (1:2.4, 1:2.1) and diameter of the largest stone to diameter of CBD excluding stone (1:0.9, 1:0.4) for patients with complete clearance compared with those without. Conclusion : We propose that stones without the fragments are travelable sufficient space in CBD or extractable sufficient diameter of CBD regardless of stone size and number should be treated by other technique to prevent time and cost consuming, such as percutaneous transhepatic cholangioscopylithotomy.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.97-103
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• 2005

Objective : The aim of this study was to compare the knee joint displaying between the anteroposterior weight bearing(AP-WB) View and the metatarsophalangeal(MTP) view for assessing joint space narrowing(JSN) and osteophytes in osteoarthritis patients. Subjects and Materials : Two hundreds of twenty patients(38 men) who came rheumatoid caused by knee pain, had both AP-WB and MTP views taken on a day. Radiographs were evaluated independently by 13 experienced observers(3 orthopedics surgeon, 2 rheumatogist, 3 radiologist, 5 radiological technologist) They assessed JSN and osteophytes using by PACS monitor JSN was scored by the optic evaluation to the nearest at the narrowest point in medial compartments of the tibiofemoral joint in both knees. Osteophytes were graded 0 to 3(bad 0, not bad 1, good 2 and very good 3) according to a standard atlas. All exam was using by Philips(Buckey Diagnostic-TH) X-ray material. Exposure condition was 60 kv, 8 mAs and 100 cm focus to film distance. Results : JSN was scored $1.32{\pm}0.050$ in AP-WB view, $2.51{\pm}0.046$ in MTP view. MTP view of JSN score is higher to AP-WB view significantly(p<0.05). Osteophytes scored $2.14{\pm}0.054$ in AP-WB view, $2.10{\pm}0.054$ in MTP view. There was no difference(p<0.05) between MTP view and AP-WB view in osteophytes. But MTP view was more reproducible than AP-WB view Conclusions : Joint space narrowing is most important factor to diagnosis with knee joint Osteoarthritis patients. This study was summarized as follows; In comparision of JSN, MTP view was more widely displayed than AP-WB view. In comparision of Osteophytes, there was no difference between MTP view and AP-WB view. It was concluded MTP view was more useful method to diagnosis of knee joint Osteoarthritis patients.

• Journal of radiological science and technology
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• v.29 no.2
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• pp.75-81
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• 2006

In the past, most patient of breast cancer suffered side effects due to the useless removement of Axillary Lymph Node, but there is no need to remove it because of the result in this study. The purpose of this study is to save surgery time and side effects after surgical operation for patients with breast cancer by making decisions of operation range for metastasis in first Stenosis Lymph Node using the $^{99m}Tc-Tincolloid$ Scintigraphy and the Micro Probe for radioisotope. As a result of this study, 15 among 20 patients became objects of this study could reduced side effects for operation because there were no axillary lymph node operations. However there is no standard for method of this treatment. It should be standardize where inject point is, how much $^{99m}Tc-Tincolloid$ should be injected(radioactivity value), and the need of massage and Lymph Scintigraphy. Nevertheless I think that this result of study is useful to reduce suffering and side effects from breast cancer and also we should try to do that continuously. The objects for this study were 20 patients diagnosed as breast cancer by Ultrasonography, Mammography & Biopsy. The average of patient age was 45.4 years and its range was between 31 and 71 years. In case of clinical period there were 9 patients of Period I and II patients of Period III. The equipment for this study were $^{99m}Tc-Tincolloid$ describing the Stenosis Lymph Node as a tracer, Micro Probe : Neoprobe 2000(the rest is Gamma Probe) tracing the location, and MS-II Gamma Camera : SIEMENS(the rest is MS-II Gamma Camera) describing the images. There were 3 methods for this study, after selecting one of those methods all 20 patients were performed Stenosis Lymph Node diagnosis & Gamma Probe in operation room. The result was that I imaged all the 20 patients, and seek the Stenosis Lymph Node by using Gamma Probe. Metastasis in Stenosis Lymph Node was 5 and Metastasis in Axillary Lymph Node was 3 between Metastasis in Stenosis Lymph Node cases. Finally 15 patients were also proved that Axillary Lymph Node was Positive and that means there was no Metastasis in Axillary Lymph Node.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.1-10
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• 2013

IEC publications have applied in many countries all over the world such as Europe or Japan and these also have been published as in dustrial standards (KS) and notifications of Korea Food and Drug Administration (KFDA) in Korea. As the general standard of IEC 60601 series for medical electric (ME) equipment was revised as $3^{rd}$ edition in 2005, additional and particular standards have been revised or established newly. Under these circumstances, it is importance for manufacturing and assembling companies or authorized testing companies to understand the trend for revisions of IEC publications. Therefore in this study, the latest version of 3 IEC standards related to medical X-ray equipment : IEC 60601-2-44 for X-ray equipment for computed tomography (CT), IEC 60601-2-45 for mammographic X-ray equipment and IEC 60601-2-54 for X-ray equipment for radiography or radioscopy were covered and analyzed for trends and features accompanied by revision based on IEC 60601-1 $3^{rd}$ Ed. As KFDA notifications in force have referred to the particular standards based on 2nd edition of IEC 60601-1, those revised version of 3 particular standards were compared to KFDA notifications in force. The features of the latest standards applying IEC 60601-1 $3^{rd}$ Ed were shown as following: 1) Requirements for mechanical hazards, especially (motorized) moving parts were emphasized. 2) Indication and recording of patient dose were required. 3) Risk management process was introduced and enabled to monitor potential risks systematically. 4) DR system (digital radiography system) as well as analogue system (film-screen system) was included in the scope. Presently, KFDA will revise the notifications applying the particular standards based on IEC 60601-1 $3^{rd}$ Ed in a few years. Therefore the features of particular standards applying IEC 60601-1 $3^{rd}$ Ed was expected to help manufacturers, assemblers or testing companies of medical electric equipment understand IEC publications or KFDA notifications slated to be published.

• Journal of radiological science and technology
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• v.40 no.4
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• pp.633-638
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• 2017

The amount of radioactive waste has been rapidly increased with development of radiation treatment in medical field. Recently, it has been a common practice to use I-131 for thyroid cancer, F-18 for PET/CT and Tc-99m for diagnosis of nuclear medicine. All the wastes concerned have been disposed of by means of the self-disposal method, for example incineration, after storage enough to decay less than clearance level. IAEA proposed criteria for clearance level of waste which depends on the individual ($10{\mu}Sv/y$) and collective dose (1 man-Sv/y), and concentration of each nuclide (IAEA Safety Series No 111-P-1.1, 1992 and IAEA RS-G-1.7, 2004). In this study, specific radioactivity of radioactive waste contaminated with Re-186 was measured to confirm whether it meets the clearance level. Re-186 has long half life of 3.8 days relatively and emits beta and gamma radiation, therefore it can be applied in treatment and imaging purposes. The specific radioactivity of contaminated gloves weared by radiation workers was measured by MCA(Multi-channel Analyzer) which was calibrated by reference materials in accordance with the measuring procedure. As a result, comparison evaluation of decay storage period between the half-life which was calculated by attenuation curve based on real measurement and physical half-life was considered, and it is showed that the physical half-life is longer than induced half-life. Therefore, the storage period of radioactive waste for self-disposal may be curtailed in case of application of induced half-life. The result of this study will be proposed as ISO standard.

• Journal of Chest Surgery
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• v.31 no.9
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• pp.827-836
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• 1998

Background: Effective cardiopulmonary resuscitation (CPR) should provide acceptable hemodynamics for the vital organs during cardiac arrest and early restoration of spontaneous circulation that guarantees long-term, neurologically intact survival. CPR using heart-lung bypass has been suggested as an option for that use. This study was designed to determine the effectiveness of standard CPR techniques, closed-vs. open-chest CPR, which could be used in the future study verifying the role of heart-lung bypass CPR. Material and Method: By using adult mongrel dogs, closed-chest CPR (CCCPR, n=4) and open-chest CPR (OCCPR, n=5) were compared with respects to hemodynamics, restoration of spontaneous circulation(ROSC), and survival. Ventricular fibrillation-cardiac arrest (VF-CA) was induced by electrical shock in all animals. After 4 minutes of cardiac arrest, basic life support (BLS) was applied for 15 minutes and followed by advanced life support (ALS). ALS was maintained until achi ving ROSC but not longer than 30 minutes regardless of the recovery. Resuscitation procedures in either group were standardized by adopting the protocol of American Heart Association. Result: Prearrest baseline hemodynamic data was not different between two groups. During resuscitation, substantially higher systolic pressure was maintained in OCCPR group than in CCCPR group (45$\pm$15 vs. 33$\pm$11 mmHg during BLS, 83$\pm$36 vs. 44$\pm$15 mmHg during ALS; p=NS). Mean pulmonary arterial pressure went up to the level of mean systemic arterial pressures in CCCPR group and to half of that in OCCPR group, and had kept higher in CCCPR group throughout CPR (32$\pm$10 vs. 22$\pm$4 mmHg during BLS and 32$\pm$15 vs. 24$\pm$10 mmHg during ALS; p=NS). ROSC was obtained in 4 of 5 dogs receiving open-chest CPR and 2 of 4 closed-chest CPR. Prolonged survival was noted in all dogs in OCCPR group (6 to 1440 hours) but not in CCPR group (p<.05). Conclusion: These findings indicate that open-chest CPR can be more effective t maintain hemodynamics during cardiac arrest and to obtain restoration of spontaneous circulation and survival. Further experiment will be designed to compare heart-lung bypass CPR with open-chest CPR.