• Title/Summary/Keyword: weak acid

Search Result 465, Processing Time 0.02 seconds

The PWM Control Which used Microprocessor for Intensity Control of Acid Ion Water (산성이온수 농도제어를 위한 Microprocessor를 이용한 PWM 제어)

  • Kwon, Yunjung;Nam, Sangyep
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.50 no.7
    • /
    • pp.269-274
    • /
    • 2013
  • We are used with the alkaline ion water which an application field does to object for drinking water compare with the alkaline ion water which asked ion acid electrolysis so as to be very different. This is used with sterilization disinfection use by residual chlorine in case of strong acidity according to ph intensity, and in case of middle acidity use by washing and face washing, and mix with meal materials in case of weak acidity widely usable in cooking. Acid ion water generates as we electrolyze water. Chlorine gas and sodium hydroxide etc. was generated at electrolysis process, and we have toward sterilizing power. Derelicts such as chlorine, phosphorus, sulfur etc. are gathered from a negative ion, and we make acid ion water to + electrode direction in electrolysis. We used a diaphragm in order to disconnect too acid water and alkaline water. We implemented so that the acid water which it came down to three kinds of PWM voltage to PWM (pulse width modulation) control, and implementation method of ph intensity change authorized ph intensity between weak acidity to electrode in strong acidity as we used Microprocessor, and intensity was adjusted successively by PWM control was generated.

Nonlinear self-tuning regulator for neutralization of weak acid streams by a strong base

  • Lee, Sang-Deuk;Lee, Ji-Tae;Park, Sun-Won
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1989.10a
    • /
    • pp.786-789
    • /
    • 1989
  • A nonlinear self-tuning regulator for a neutralization process of a weak acid and strong base system is proposed. Rearranging the state equation of the process model, we first obtain equations which are linear for a manipulated variable or unknown parameters. Then to these equations we apply the standard procedure used in designing linear self-tuning regulators. Simulation results show that the regulator provides very good performances for various realistic situations and traces variations of the unknown parameters. Since computations are simple and additional measurements except the effluent pH value are only flow rates of influent streams, it can be easily applied to real processes such as a waste water treatment process.

  • PDF

Effect of Particle Pre-Treatment on Properties of Jatropha Fruit Hulls Particleboard

  • Iswanto, Apri Heri;Febrianto, Fauzi;Hadi, Yusuf Sudo;Ruhendi, Surdiding;Hermawan, Dede;Fatriasari, Widya
    • Journal of the Korean Wood Science and Technology
    • /
    • v.46 no.2
    • /
    • pp.155-165
    • /
    • 2018
  • The objective of the research was to evaluate the effect of particle pre-treatment on physical, mechanical, and durability of jatropha fruit hulls (JFH) particleboard. The pre-treatments included were immersing in cold water, hot water, and acetic acid solution. After each treatment, the particles were dried up to 3% moisture content. Urea-formaldehyde (UF) resin was used to fabricate particleboards with board size, thickness and density target of 25 cm by 25 cm, 0.80 cm, and $0.70g/cm^3$, respectively. Board pressed at $130^{\circ}C$ for 10 minutes, and $25kg/cm^2$ pressure. The evaluation of particleboard followed the JIS A 5908-2003. Whilist their resistance to subterranean termite test (mass loss, mortality, antifeedant value and feeding rate) refers to the Indonesian standard (SNI 01.7207-2006). The physical and mechanical properties of particleboards showed that all pre-treatments decreased the pH of particles. Overall, all particle immersing treatments resulted of better physical and mechanical properties of particleboard than those of untreated ones. The acetic acid treatment resulted the best physical and mechanical properties of particleboard. Based on the mass loss of JFH particleboard, hot water and acetic acid treated particleboards were classified into weak resistance to subterranean attack. The other two treatments were classified into very weak resistance. Hot water treated particleboard provided the highest mortality and antifeedant as much as 87.40% and 34.20%, respectively. Based on antifeedant classification, hot water treated particleboards were classified into moderately strong resistance, while other treatments were categorized into weak resistance. The lowest feeding rate value ($45.30{\mu}g/termite/day$) was attained by hot water treatment.

The Effect of Dihydrocholanic Acid on Choleretic Action (Dihydroxycholanic Acid 류의 이담작용에 관한 연구)

  • 홍사욱;조석준;조태순
    • YAKHAK HOEJI
    • /
    • v.22 no.4
    • /
    • pp.193-200
    • /
    • 1978
  • Cholic, ursodesoxycholic, chenodesoxycholic, desoxycholic and hydesoxycholic acids were dissolved in the propylene glycol to make solution and then above solution of cholanic acids on bile secretion was investigated by injection those solutions into small intestine of rabbits and albino rats. The cholates in bile juice from rabbits injected with cholic acid were remarkably increased and therefore it exhibited a typical choleretic action. In view of pharmacological point, desoxycholic acid is considered as superior hydrocholeretic agent, and ursodesoxycholic and chenodesoxycholic acids have similar effect in decreasing order. However, the effect of bile secretion by hyodesoxycholic acid was almost negligible as that by propylene glycol administered. The cholate content in the bile juice from albino rat was increased by cholic and desoxycholic acids in decreasing order: i.e., they exhibited choleretic action. In the case of ursodesoxycholic and chenodesoxycholic acids, the concentration of cholate was slightly increased in bile juice from the rat, so that these cholates showed a weak choleretic action. While total output of bilirubin was increased by chenodesoxycholic acid, the other cholanic acid showed no effect in the rabbit.

  • PDF

Discoloration of Woods (2) - 36 Commercial Hardwoods Grown in Korea - (목재(木材)의 오염(汚染)에 의한 변색(變色) (2) - 한국산(韓國産) 활엽수재(闊葉樹材)의 화학적(化學的) 변색(變色) -)

  • Ahn, Kyung-Mo;Kong, Young-To;Jo, Jae-Myeong
    • Journal of the Korean Wood Science and Technology
    • /
    • v.14 no.1
    • /
    • pp.55-60
    • /
    • 1986
  • Discoloration sensitivities of woods grown in this country haven't reported yet. Therefore we examined discoloration sensitivities of domestic wood specimens to iron (0.1 %, $FeCl_3.6H_2O$), alkali (pH 12.0, NaOH). acid (pH 1.0, $C_2H_2O_4$) and exposing to sunlight (40 hrs), Thirty-six hardwood species were collected and examined. All specimens were prepared from heartwoods of the collected species. But the specimens of 4 Betula species were divided into sapwoods and heartwoods. By iron stain, the color differences (${\Delta}E$) of 21 wood specimens including one Betula sapwood showed above 12.0, which means strong discoloration sensitivities, and of 3 specimens including one Betula sapwood showed below 2.5, which means weak discolorations. The most strong iron discoloration species was Jungkukgulpi-namu (Pterocarya stenoptera). By alkali stain, the color differences (${\Delta}E$) of 3 wood specimens showed above 9.0, which means strong discoloration sensitivities, and of 18 wood specimens including 4 Berula sapwoods showed below 2.5, which means weak discolorations. By acid stain, the color differences (${\Delta}E$) of 6 wood specimens showed above 10.0 which means strong discoloration sensitivities, and of 12 wood specimens including one Betula sapwoods showed below 2.5, which means weak discolorations. By exposing to sunlight, the color differences (${\Delta}E$) of 31 wood specimens including one Betula sapwoods showed below 6.5, which means, strong discoloration sensitivities, and of only one specimens showed below 2.5, which means weak discoloration. The most strong discoloration species by exposing to sunlight was Guirung-namu (Prunus padus). In general, it was shown that hardwoods grown in Korea were most subject to change of color by exposing to sunlight and next were by iron stain. Domestic hardwoods showed some differences in discoloration sensitivities from domestic softwoods previously reported.

  • PDF

A STUDY ON THE ANTIBACTERIAL EFFECT OF IRRIGATION SOLUTIONS TO STREPTOCOCCI (수종 근관 세척액의 연쇄구균에 대한 항균효과)

  • Shim, Jae-Han;Im, Mi-Kyung;Han, Du-Seok
    • Restorative Dentistry and Endodontics
    • /
    • v.17 no.1
    • /
    • pp.115-125
    • /
    • 1992
  • It is advisable to use irrigation solutions which have strong antibacterial effect and weak cytotoxic effect on treating root infections. Streptococci are ones of the most frequently isolated microorganisms in infected root canals. The antibacterial effect of ten irrigation solutions were investigated on S. mutans (19449), S. sanguis. )10556) and 4 streptococci isolated from saliva of healthy persons. These streptococci were exposured to irrigation solutions during 10 sec, 30 sec,. 1 min, 3 min, 5 min, 10 min, 30 min and 2hrs respectively. Four irrigation solutions which showed strong antibacterial activity were diluted to 1 : 1 to 1 : 10,000. Then they were subcultured on blood agar plate an observed after 1 day. 5.25% NaOC1 had the strongest antibacterial effect. 30% urea and normal saline showed no antibacterial effect. 50 % citric acid and 3% $H_2O_2$ showed relatively weak antibacterial effect. 15 % EDTA had very weak antibacterial effect.

  • PDF

Effect of Acid Drainage and Countermeasure about Road Cut Slope Environment (도로절개면 환경에 관한 산성배수의 영향과 대책)

  • 김진환;이종현;구호본;박미선
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2003.03a
    • /
    • pp.481-484
    • /
    • 2003
  • Sulfide minerals contacted with air and water in coal seam cause oxidation reactions. This oxidation reactions make low pH of groundwater and surface water(Acid Drainage). The reddish brown precipitate collected from the cut slope of the study area was estimated using the X-Ray Diffractometer(XRD). XRD results show that the cut slope was affected by Acid Drainage. The cut slope exposured to Acid Drainage become weak about chemical weathering and defile the appearance of the road. Drainage facilities are very important in Cut Slope under Acid Drainage influence. Reactions between Coal seam and water cause chemical weathering and environmental problem. Therefore It is important to control the transfer paths of groundwater and surface water and to install water collecting facilities

  • PDF

Effects of Acid Fog and CaCl2 on the Corrosion Fatigue Strength of Structural Steel (구조용 강재의 부식피로 강도에 미치는 산성안개 및 염화칼슘의 영향)

  • Kim, Min-Gun;Kim, Myoung-Sub
    • Journal of Industrial Technology
    • /
    • v.21 no.A
    • /
    • pp.17-26
    • /
    • 2001
  • The fatigue strength of SM55C has significantly decreased by 83% compared with atmosphere where distilled exists due to strong erosive action of acid fog. The reason is inferred in a way that strong acid erosive material such as acid fog act and give rise to multi-site crack on the surface. Several fatigue clacks occurred under the acid fog repeat the process of division and unification on the surface and form a long non-propagating crack throughout the circumference of experimented steel. However, in the depth, many parts do not show much trace of unification, and the depth is not as big as the one of normal crack shape. 10% of $CaCl_2$ causes strong erosive reaction to material. Then eventually make the life of fatigue shooter. On the other hand, 20% of $CaCl_2$ beings about oxidized material organic crack closing due to weak erosive reaction.

  • PDF

Effects of Oleic Acid on the Autoxidation of Rice Bran Oil (미강유의 자동산화에 미치는 Oleic Acid의 첨가 효과)

  • 이성호;신영순
    • The Korean Journal of Food And Nutrition
    • /
    • v.6 no.1
    • /
    • pp.47-52
    • /
    • 1993
  • In the present study, an attempt was made to investigate the effect of oleic acid on the autoxidation of the commercial rice bran oil. Rice bran oil samples with oleic acid at 0.1, 0.3 and 0.5% level were kept at 45 $\pm$ 0.3$^{\circ}C$ for 40 days. The rate of autoxidation of each samples was estimated regularly on the basis of the changes of peroxide value, acid value, anisidine value and the fatty acid composition. The per oxide, acid and anisidine values of the rice bran oil with the oleic acid increased as compared with that of the rice bran oil without the oleic acid during the autoxidation. The induction period of the rice bran oil without the oleic acid, control was 19.8 days, while those of the rice bran oil with oleic acid at 0.1, 0.3 and 0.5% levels were 18.3 days, 16.8 days, and 15.5 days, respectively. In conclusion, it seemed that oleic acid acted as weak prooxidant when added at 0.1, 0.3 and 0.5% levels to the commercial rice bran oil.

  • PDF

Effects of Stearic Acid on the Autoxidation of Rice Bran Oil (미강유의 자동산화에 미치는 Stearic Acid의 첨가 효과)

  • 이성호;신영순
    • The Korean Journal of Food And Nutrition
    • /
    • v.4 no.2
    • /
    • pp.167-174
    • /
    • 1991
  • In the present study, an attempt was made to Investigate the effect of stearic acid on the autoxidation of the commercial rice bran oil, Rice bran oil samples with stearic acid at 0.1, 0.3 and 0.5oh level were kept at 45$\pm$0.3$^{\circ}C$ for 40 days. The rate of autoxidation of each samples was estimated regularly on the basis of the changes of peroxide value, acid value, anisidine value and the fatty acid composition. The results were as follows : The peroxide, acid and anisidine values of the rice bran oil with the stearic acid at 0.1, 0.3 and 0.591 levels during the autoxidation Increased as compared with that of the rice bran oil without the stearic acid. The induction period of the rice bran oil without the stearic acid, control was 19.0days, while those of the bran oil with stearic acid at 0.1, 0.3 and 0.5% levels varied 19.0 days, 17.7days and 14.2 days, respectively. In conclusion, it seemed that stearic acid acted as weak prooxidant when added at 0.1, 0.3 and 0.5% levels to the commercial rice bran oil. The prooxidant activity of the stearic acid appeared to depend on the oxidative mechanism and their concentration.

  • PDF