• The Korean Journal of Nuclear Medicine
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• v.33 no.1
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• pp.100-109
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• 1999

Purpose: Preamplifier and amplifier are very important parts for developing a portable counting or imaging gamma probe. They can be used for analyzing pulses containing energy and position information for the emitted radiations. The commercial Nuclear Instrument Modules (NIMs) can be used for processing these pulses. However, it may be improper to use NIMs in developing a portable gamma probe, because of its size and high price. The purpose of this study was to develop both preamplifier and amplifier and measure their performance characteristics. Materials and Methods: The preamplifier and amplifier were designed as a charge sensitive device and a capacitor resistor-resistor capacitor (CR-RC) electronic circuit, respectively, and they were mounted on a print circuit board (PCB). We acquired and analyzed energy spectra for Tc-99m and Cs-137 using both PCB and NIMs. Multichannel analyzer (Accuspec/A, Canberra Industries Inc., Meriden Connecticut, U.S.A) and scintillation detectors (EP-047(Bicron Saint-Gobain/Norton Industrial EP-047 (Ceramics Co., Ohio, U.S.A) with $2"{\times}2"$ NaI(T1) crystal and R1535 (Hamamatsu Photonics K.K., Electron Tube Center, Shizuoka-ken, Japan) with $1"{\times}1"$ NaI(T1) crystal were used for acquiring the energy spectra. Results: Using PCB, energy resolutions of EP-047 detectors for Tc-99m and Cs-137 were 12.92% and 5.01%, respectively, whereas R1535 showed 13.75% and 5.19% of energy resolution. Using the NIM devices, energy resolutions of EP-047 detector for Tc-99m and Cs-137 were measured as 14.6% and 7.58%, respectively. However, reliable energy spectrum of R1535 detector could not be acquired, since its photomultiplier tube (PMT) requires a specific type of preamplifier. Conclusion: We developed a special preamplifier and amplifier suitable for a small sized gamma probe that showed good energy resolutions independent of PMT types. The results indicate that the PCB can be used in developing both counting and imaging gamma probe.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.1014-1018
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• 2001

Pigs respond to extreme temperature (very cold or hot) by physiological and nutritional adjustments. Yet little is known about the effects of different environmental temperature (thermoneutral in the highland area, and hot temperature in the coastal area) where pigs are maintained on the performance of the pigs. Ten pigs each (10 pairs of littermates) were assigned to two treatments (2 locations): highland area (control=CA) or coastal area (hot/heat stress=HS). Experimental design was Paired 't' test. HS pigs had higher average daily water intake (p<0.05) compared to CA pigs (6,05 vs 3.89 kg/d), CA pigs had higher feed intake compared to HS pigs (2.9 vs 1.95 kg/d, p<0,05). CA pigs had higher daily gain compared to HS pigs (0.72 vs 0.58 kg/d, p<0.05). Feed conversion was not significantly different between CA pigs and HS pigs. The digestibility of dry matter, N, Na, K, Mg, CI, Ca and P was not significantly affected by the treatments. High environmental temperature in the coastal area (heat stress) increased water intake, decreased voluntary feed intake and daily gain of the pigs. The results demonstrate that different environmental temperature in the coastal area (heat stress) and highland area (control) had no pronounced effect on digestibility of nutrients.

• Journal of environmental and Sanitary engineering
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• v.8 no.1
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• pp.81-91
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• 1993

This paper was carried out to isolate and identify Aeromonas caviae which can degrade Sodium Dodecyl Benzene Sulfonate(SDBS) effectively. And the affecting factors for the ability of bacterial degradation were also studied. Frm October 1991 to February 1992, two hundred samples from sweage in Taegu area and Nakdong river waters in Talsung Gun area were tested. Minimal salt medium which contain SDBS only as a carbon source was used as a culture medium. The isolated new strain was identified as Aeromonas caviae Kim & Kweon. The optimal pH for SDBS degradation were 7.0 and temperature, $32^{\circ}C.$ It was taken 24 hours to degrade SDBS of 20mg/l completely under the optimal pH and temperature. And in the case of 30 mg/l of SDBS, it was taken 36 hours. The nitrogen sources were added to the minimal salt media containing 20mg/l of SDBS, and they were incubated at $32^{\circ}C$ for 14 hours. 86.9% SDBS were degraded after addition of 0.03% peptone as a organic nitrogen source. And 70.5% SDBS after addition of 0.05% ammonium sulfate as a inorganic nitrogen source. In the case of metal compounds(0.015%), the degradation rate for SDBS were 3.5 fold increased in the media containing magnesium chloride and calcium chloride than in the media that were not containing these metal compounds. And where the media containing magnesium chloride was 0.05%, the degradation rate was 65.8%. And above 0.3% NaCI, the degradation rate was decreased slowly.

• Analytical Science and Technology
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• v.11 no.2
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• pp.125-129
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• 1998

The purpose of this study was to give a quantitative analysis for assessing the tarnish resistance of alloys at the artificial saliva, 0.9% NaCI solution and Ringer's solution. In light of development in low-nobility alloys, it is important that tarnish test is standardized to analyse the tarnish properties of the compositions. There are concerns with the long term chemical stability of these alloys and the resistance to tarnish. Chemical stability is a complex problem involving alloy composition, nobility, microstructure and environment.

• The Journal of Internal Korean Medicine
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• v.35 no.3
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• pp.343-353
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• 2014

Objectives: To discuss the application of the acupuncture therapy for the HIV-associated distal sensory neuropathy. Methods: We searched papers using KTKP, Oasis, CNKI, PubMed, Science Direct, CINAHL, J-STAGE, and CiNii with the keywords "HIV", "Peripheral neuropathy" and "acupuncture". The search range included randomized controlled trials (RCTs) and clinical case series. Reviews and animal experiments were not included. Not matched with inclusion criteria were excluded. Results: A total 675 studies were found. 670 were excluded by scanning titles and abstracts and finally 5 articles were selected. One of the five articles noted that acupuncture was not effective in HIV-SN, but two articles reanalyzing the former, pointed out the statistical errors and noted acupuncture significantly reduced pain, attrition and mortality. Other RCT and the other case series concluded acupuncture had a beneficial effect in HIV-SN. Conclusions: Acupuncture seems to be effective to improve HIV-SN symptoms, however further large-scale RCTs are warranted.

• The Journal of Engineering Geology
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• v.13 no.3
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• pp.281-292
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• 2003

We setup a continuous measurement system for electrical conductivity of fluid in a model borehole and verified the basic environments in electrical conductivity measurement for estimating hydraulic constants. The experiment was made by monitoring the conductivity change within the hole using NaCI solution of different salinities and incoming formation fluid using distilled water. The experiment was made under the state of constant flow rate by maintaining balance between inflow and outflow. Conductivity variation features were observed by controlling salinity contrasts and temperature differences between fluid within the hole and incoming formation fluid. flow rate and the location of inlet and outlet. The results of the experiment show well the role of each affecting factor on the conductivity distribution. and suggest appropriate environments for conductivity measurements. It is considered that the basis of the conductivity measurement for henceforward laboratory model and/or in-situ borehole experiment has been prepared.

• Environmental Engineering Research
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• v.22 no.3
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• pp.312-319
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• 2017

The treatment of dyeing wastewater is not easy because dyes are mainly aromatic, heterocyclic compounds. The most effective technologies and methods to treat dyeing wastewater are costly and involve materials that are difficult to regenerate after use. Therefore, it is necessary to develop cost-effective, eco-friendly technologies to treat dyeing wastewater. The aim of this study was to investigate the removal of sulfur blue 11 (CI 53235) anionic dye using methyl esterified sericite (ME-sericite) adsorbents in an aqueous solution. The results are discussed in terms of the ME-sericite particle size, temperature, pH value and initial sorption rate according to the initial sulfur blue concentration. In addition, we analyzed the adsorption kinetics using a Pseudo-second-order model with the desorption and reusability. The methyl esterification caused a considerable increase in the specific surface area from 4.45 to $17.62m^2/g$. The ME-sericite adsorbents successfully removed > 98% of the sulfur dye in the aqueous solution. For the adsorption of 1 mg of sulfur dye, approximately 4.6 to 6.6 g/L ME-sericite were required. The desorption process was carried out by mixing a NaOH eluent to desorb 90.56% of the sulfur dye with 2 h of contact time. Thus, the ME-sericite is a promising adsorbent to treat dyeing wastewater due to its low dose requirement, high removal efficiency and inexpensive material.

• Transactions of Materials Processing
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• v.22 no.2
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• pp.74-79
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• 2013

The ultra-precision polishing method using MR fluid has come into the spotlight for polishing metals and optical materials. The MR fluid jet polishing process can be controlled using a change of viscosity by an imposed magnetic field. The MR fluid used for polishing process is a mixture of CI particles, DI water, $Na_2CO_3$ and glycerin. The efficiency of polishing depends on parameters such as polishing time, magnetic field, stand-off distance, pressure, etc. In this paper, the MR fluid jet polishing was used to polish nickel and brass mold materials, which is used to fabricate backlight units for 3-D optical devices in mobile display industries. In MR jet polishing, ferromagnetic materials like nickel can decrease the polishing efficiency by interaction with the cohesiveness of the MR fluid more than non-ferromagnetic materials like copper. A series of tests with different polishing times showed that the surface roughness of brass (Ra=1.84 nm) was lower than that of nickel (Ra=2.31 nm) after polishing for 20 minutes.

• Journal of Environmental Science International
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• v.14 no.1
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• pp.97-103
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• 2005

Because of the toxicity of hexavelant chromium ion, treatments of metallic surface with chromate compounds to retard corrosion are undesirable for safety control in industrial uses and protection of environment. In this study, we investigated several compounds such as inorganic, organic, and polymer materials in order to sub­stitute the chromate conversion treatment on steel sheet. The corrosion property was investigated in a salt spray tester with 3.5 $wt.{\%}\;NaCI\;at\;35^{\circ}C.$ The results showed that the zirconium/silane/polymer triple coatings on the galvanized steel exhibited a significant retardation of corrosion. Although the multicoating system needs a com­plexed processing, we can confirm a possibility of development of a chromate-free chemical conversion treat­ment for galvanized steel sheet.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.5
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• pp.2323-2328
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• 2014

Background: Epidemiological findings are controversial relating to the relationship between dietary folate intake and the risk of breast cancer. We therefore conducted a meta-analysis of prospective cohort studies to clarify this association. Materials and Methods: PUBMED, EMBASE, and MEDLINE databases were searched for all relevant literature published in English from January 1, 1966 to August 2013. Summary relative risk (RR) and 95% confidence intervals (CIs) were calculated using a fixed or random effects model. Results: Dietary folate intake was not significantly associated with the risk of breast cancer. The combined RR with 95%CI for the highest vs. lowest category dietary intake of folate [fifteen studies; 1,836,566 participants and 24,083 patients with breast cancer] was 0.98 (0.90-1.05). Among subgroup analysis by menstrual status, hormonal status and the consumption of alcohol, methionine and vitamin B12, no significant association was observed for the dietary intake of folate and the risk of breast cancer. Dose-response analysis showed that a 220 ${\mu}g/day$ increment in dietary folate intake was not associated with the risk of breast cancer. Conclusions: Our findings indicate that dietary folate intake has no significant effect on the risk of breast cancer.