• Title/Summary/Keyword: Chemical factors

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Critical factors in sol-gel transition of silicon metal alkoxide solutions (Silicon metal alkoxide 용액의 sol-gel 전이에서 중요인자)

  • ;;Hiromitsu Kozuka;Sumio Sakka
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.4
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    • pp.332-342
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    • 1995
  • The important factors of reaction conditions in sol-gel transition of silicon alkoxide solution have been reviewed and discussed on the basis of Raman study. Various factors such as type of catalyst, alkoxide, solvent, drying control chemical additive and water content affect the conversion mechanism in sol-gel process.

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The effects of Ultrasound on the Platelet of Rats (초음파가 생쥐의 혈소판에 미치는 영향)

  • Cho, Kwang-Ho;Park, Sang-Ock;Park, Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.13 no.1
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    • pp.139-149
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    • 2001
  • We found out that there exists threshold dose for the decreased platelet count when we apply change of the platelet count to the defense of the ultrasound experiment. Those diminution is definite effects from the defense of the ultrasound. The number of the platelet count is decreased when we are exposed to ultrasound simultaneously. This should not be occurred. It is easy to use the number of the platelet count in the measurement of the biological dosage and intensity in high dosage relatively due to definite quantative relationship. The biological index to understand synergic effects. which are present when two harmful environmental factors are operating at the same time is functionally assending and antagonistic. There are scattered many factors as physical, Chemical, or physiochemically elements which are harmful to human body in the environment in consideration of ultrasound and the other factors. This experiment is demonstrating that we can use the change of the platelet as an index representing synergic effects of ultrasound.

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A Study on the Prediction of Parturient Syndrome in Holstein Cows (젖소에서의 산욕기질병 발생예견에 관한 연구)

  • Youn Hwa-Young;Choi Hee-In
    • Journal of Veterinary Clinics
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    • v.2 no.1
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    • pp.133-141
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    • 1985
  • In order to establish a method predicting susceptible cows to the parturient syndrome, various serum chemical parameters (calcium, phosphorus, Ca/P, magnesium, cholesterol, total protein, albumin, globulin, A/G, total lipid, non-esterified fatty acid(NEFA) and aspartate aminotransferase(AST)) were measured during late pregnancy and their relationships with periparturient diseases were investigated during puerpural period. The results obtained were as follows : 1. The factors affecting the prediction of susceptible cows to parturient syndrome were calcium, magnesium, total protein, globulin, A/G ratio and total lipid at 30 day antepartum and the diagnosability was 70.7%. 2. In the experimental cows producing more than 21kg of milk per day, the factors affecting the prediction of susceptible cows to parturient syndrome were calcium, NEFA and A/G ratio at 30 day antepartum and the diagnosability was 66.7%. 3. In the experimental cows calved more than 3 times, the factors affecting the perdiction of susceptible cows to parturient syndrome were calcium, total protein, albumin and NEFA at 30 day antepartum and the diagnosability was 83.3%.

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Analysis of Factors Impacting Atmospheric Pressure Plasma Polishing

  • Zhang, Ju-Fan;Wang, Bo;Dong, Shen
    • International Journal of Precision Engineering and Manufacturing
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    • v.9 no.2
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    • pp.39-43
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    • 2008
  • Atmospheric pressure plasma polishing (APPP) is a noncontact precision machining technology that uses low temperature plasma chemical reactions to perform atom-scale material removal. APPP is a complicated process, which is affected by many factors. Through a preliminary theoretical analysis and simulation, we confirmed that some of the key factors are the radio frequency (RF) power, the working distance, and the gas ratio. We studied the influence of the RF power and gas ratio on the removal rate using atomic emission spectroscopy, and determined the removal profiles in actual operation using a commercial form talysurf. The experimental results agreed closely with the theoretical simulations and confirmed the effect of the working distance. Finally, we determined the element compositions of the machined surfaces under different gas ratios using X-ray photoelectron spectroscopy to study the influence of the gas ratio in more detail. We achieved a surface roughness of Ra 0.6 nm on silicon wafers with a peak removal rate of approximately 32 $mm^{3}$/min.

Performance Experiment of Electron Beam Convergence Instrument (Finishing 용 전자빔 집속 장치의 성능 실험)

  • Lim, Sun Jong
    • Laser Solutions
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    • v.18 no.3
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    • pp.6-8
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    • 2015
  • Finishing process includes deburring, polishing and edge radiusing. It improves the surface profile of specimen and eliminates the alien substance on surface. Deburring is the elimination process for debris of edges. Polishing lubricates surfaces by rubbing or chemical treatment. There are two types for electron finishing. The one is using pulse beam. The other is using the convergent and scanning electron beam. Pulse type device appropriates the large area process. But it does not control the beam dosage. Scanning type device has advantages for dosage control and edge deburring. We design the convergence and scan type. It has magnetic lenses for convergence and scan device for scanning beam. Magnetic lenses consist of convergent and objective lens. The lenses are designed by the specification(beam size and working distance). In this paper, we evaluate the convergence performance by pattern process. Also, we analysis the results and important factors for process. The important factors for process are beam size, pressure, stage speed and vacuum. These results will be utilized into systematizing pattern shape and the factors.

Assessments of the Combined Effect of Installation Damage and Creep on the Long-Term Design Strength of Geogrid for Railroad Reinforcement (철도노반 보강용 지오그리드의 크리프 및 손상이 장기 인장강도에 미치는 영향평가)

  • Lee Do-Hee;Park Tae-Soon;Cho Sam-Deok;Lee Kwang-Wu
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1156-1161
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    • 2004
  • The factors affecting the long-term design strength of geogrid for railroad reinforcement can be classified into factors on creep deformation, installation damage, temperature, chemical degradation, biological degradation. Especially, creep deformation and installation damage are considered as main factors to determine the long-term design strength of geogrid. This paper describes the results of a series of experimental study, which are carried out to assess the combined effect of installation damage and creep deformation for the long-term design strength of geogrid reinforcement. In this study, a series of field tests are carried out to assess installation damage of a various geogrids according to different fill materials, and then creep tests are conducted to assess the creep properties of both undamaged and damaged geogrids.

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Microbial Distribution in Jinhae-bay (I) (진해만의 미생물분포 I)

  • 최영길
    • Korean Journal of Microbiology
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    • v.19 no.2
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    • pp.45-51
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    • 1981
  • The physico-chemical and biological factors of coastal sea water were measured bimonthly from 1976 to 1979 for elucidating the relationship between microbial distribution and environmental factors at Masan and Jinhae bay. The experimental results are summarized as followings : 1) The polulation size of bactriz in sea water were increasing as the water temperature increased, and that was higher at station 2 and 3 than at station 1. The number of fungi showed the highest value on July on bottom. The population size of yeast showed no seasonal variation and also showed a relation with the geographic distance. 2) The correlationship between microbial distribution and environmental factors showed little coefficiency in surface water. And the other hand, at bottom water, between general bacteria and water temperature and dissolved oxygen, and between yeast and salinity, there were relatively high coefficiecy.

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A Study on the Design Concept for NBC Clothing (화생방보호의 설계 개념 연구)

  • Kang, Jae-Sung;Seo, Hyeon-Kwan;Park, Hyen-Bae;Ryu, Sam-Gon;Park, Sang-Hoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.2
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    • pp.193-200
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    • 2012
  • The selection factors of the protective clothing against the NBC agents are the protection(chemical, biological, TIMs), duration, weight/comfort, dexterity/mobility, size, visibility, cleaning and unit cost, etc. To develop the NBC protective clothing, we should need to review about the design concepts of the protective materials(shell and liner fabric) and form. This paper identify an important factors for the protective materials and form, and presents design strategies for important factors based on the evaluation results of the materials and the form.

Synthesis and Optical Properties of Novel Chemosensor Based on Rhodamine 6G

  • Kim, Hyungjoo;Son, Young-A
    • Textile Coloration and Finishing
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    • v.24 no.4
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    • pp.233-238
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    • 2012
  • The opto-functional materials have been developed as a promising research topic toward the end uses for optical materials and applications. The attractive area in this part was the design of sensor molecules for detecting harmful environmental factors. These harmful factors impart undesired effects on wide range of chemical and biological phenomenon. In this context, many researchers have studied luminescence chemosensor materials. These sensor molecules showed optical signals such as color or fluorescence change by detecting harmful environmental factors. In this study, the novel fluorescence chemosensor 1 has been designed and synthesized through reaction of rhodamine 6g hydrazide and 2-hydroxy-1-naphthaldehyde. The chemosensor 1 had been analyzed by UV-Vis and fluorescence spectrophotometer. We found that this chemosensor 1 has 'off-on' and dual type sensing properties toward $Cu^{2+}$ and $Mg^{2+}$.

Farm evaluation program on swine health management to control piglets' diarrhea (돼지 설사병 방제 양돈장 위생관리 프로그램 개발)

  • Park, Jong-myung;Hwang, Eui-kyung;Kim, In-cheon;Rhee, Jae-chin;Chung, Hyun-kyu;Kang, Ku-hwan
    • Korean Journal of Veterinary Research
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    • v.38 no.1
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    • pp.201-208
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    • 1998
  • Piglets' diarrhea is one of the major causes of economic loss in Korean swine industry. To prevent this serious and persistant problem, we have developed systemic farm evaluation and analysis program. The program consists of the checklist and the computerized program. The items of the checklist are selected on the basis of various causative factors related with the piglets' diarrhea including sanitational status, nutritional management, or farm environment. The checklist is composed of 30 items including 6 factors on facility, 8 factors on environment, 6 factors on nutrition and 10 factors on sanitation, respectively. Minimum 1 to maximum 10 points was assigned to each item depending on level or status of farm. The scores calculated by sum of points obtained from each item could find out the problems which the farm was confronted with. To investigate the applicability of a program 150 swine farms raising over 500 heads were selected from 7 provinces throughout the country and surveyed. There were significant correlations between the piglets' diarrhea and the scores of the checklist. Based on above results we revised the checklist which consisted of 22 items including 5 factors on facility, 7 factors on environment, 3 factors on nutrition and 7 factors on sanitation. After that we composed a computerized diagram out of each point of an item which showed and indicated weak factors to be improved promptly. Our present study suggested that this newly established swine farm evaluation program would be a very efficient way to find out the problems and support the systemic control program of the piglets' diarrhea for swine farms.

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