• Title/Summary/Keyword: concentration response functions

Search Result 66, Processing Time 0.011 seconds

Application of Box Wilson experimental design method for removal of acid red 95 using ultrafiltration membrane

  • Akdemir, Ezgi Oktav
    • Membrane and Water Treatment
    • /
    • v.9 no.5
    • /
    • pp.309-315
    • /
    • 2018
  • The applicability of the ultrafiltration process for color removal from dye-containing water has been examined in this study. The optimization of major process variables, such as dye concentration, chitosan concentration and transmembrane pressure on permeate flux and color removal efficiency was investigated. To find the most appropriate results for the experiment, the Box-Wilson experimental design method was employed. The results were correlated by a response function and the coefficients were determined by regression analysis. Permeate flux variation and color removal efficiency determined from the response functions were in good agreement with the experimental results. The optimum conditions of chitosan concentration, dye concentration and pressure were 50 mg/l, 50 mg/l and 3 bars, respectively for the highest permeate flux. On the other hand, optimum conditions for color removal efficiency were determined as 50 mg/l of dye concentration, 50 mg/l of chitosan concentration and 1 bar of pressure.

Concentration Response Functions for Particulate Matter related Health Risk Assessment in South Korea (입자상 대기오염물질의 건강 위해성 평가를 위한 국내 농도반응함수 도출)

  • Ha, Jongsik
    • Journal of Environmental Health Sciences
    • /
    • v.43 no.3
    • /
    • pp.202-213
    • /
    • 2017
  • Objectives: HRA (Health Risk Assessment) is an important tool for measuring the health impacts of air pollution. HRA is already being used widely as an important reference for crafting air pollution policies. However, the absence of a domestic CRF (Concentration Response Function) standard, which is a main component for HRA, could cause confusion amongst policy-makers. The purpose of this study is to tabulate a domestic CRF standard for a PM (Particulate Matter)-related HRA. Methods: This study suggested a domestic CRF standard for HRA thorough a literature review. The literature review for meta-analysis was limited to the English language for epidemiological studies published from January 1980 to March 2016. This meta-analysis was conducted by assuming both fixed- and random-effects of CRF. In addition, studies that reported HRA of air pollution for WHO (World Health Organization), the EC (European Commission), and the EPA (Environmental Protection Agency) were reviewed to compare the CRFs of South Korea to the recommended CRFs of WHO, the EC, or the EPA. Additionally, a domestic CRF standard was supplemented by these. Results: Nineteen studies were selected for the CRF for South Korea. Fifty-three CRFs were derived for meta-analysis. CRFs with a standard for PM-related HRA were divided according to the following four criteria: air pollution, exposure characteristics, type of health impact, and age group. Finally, a domestic CRF standard was created comprised of 21 CRFs. Among these, six CRFs were derived from the results of foreign HRA studies. Conclusions: This study is important in that a domestic CRF standard is first suggested. In addition, this study suggests a further area of study for using HRA as a policy tool and a direction of epidemiological study.

Combinatorial continuous non-stationary critical excitation in M.D.O.F structures using multi-peak envelope functions

  • Ghasemi, S. Hooman;Ashtari, P.
    • Earthquakes and Structures
    • /
    • v.7 no.6
    • /
    • pp.895-908
    • /
    • 2014
  • The main objective of critical excitation methods is to reveal the worst possible response of structures. This goal is accomplished by considering the uncertainties of ground motion, which is subjected to the appropriate constraints, such as earthquake power and intensity limit. The concentration of this current study is on the theoretical optimization aspect, as is the case with the majority of conventional critical excitation methods. However, these previous studies on critical excitation lead to a discontinuous power spectral density (PSD). This paper introduces some critical excitations which contain proper continuity in frequency domain. The main idea for generating such continuous excitations stems from the combination of two continuous functions. On the other hand, in order to provide a non-stationary model, this paper attempts to present an appropriate envelope function, which unlike the previous envelope functions, can properly cover the natural earthquakes' accelerograms based on multi-peak conditions. Finally, the proposed method is developed into the multiple-degree-of-freedom (M.D.O.F) structures.

The influence of obesity on the effects of spirulina supplementation in the human metabolic response of Korean elderly

  • Park, Hee-Jung;Lee, Hyun-Sook
    • Nutrition Research and Practice
    • /
    • v.10 no.4
    • /
    • pp.418-423
    • /
    • 2016
  • BACKGROUND/OBJECTIVES: Spirulina, a blue-green alga, is widely produced and commercialized as a dietary supplement with bio- and immune-modulatory functions. We have previously shown that spirulina had favorable effects on lipid profiles, immune functions, and antioxidant capacity in healthy Korean elderly. Despite favorable effect of spirulina supplementation, some sub-populations have shown a poor response to supplementation. Obesity is a factor related to poor-response. Therefore, the purpose of this study was to determine the immuno-modulation, antioxidant capacity, and lipid-lowering effect of spirulina in obese and non-obese Korean elderly. SUBJECTS/METHODS: The subjects were 78 elderly aged 60-87 years. In a randomized double blind, placebo-controlled study, subjects were fed either placebo or spirulina daily, at 8 g for 12 weeks. Subjects were divided into the non-obese group and the obese group based on body mass index (BMI) criteria for Asians suggested by the International Obesity Task Force: $BMI<25kg/m^2$ (non-obese) and $BMI{\geq}25kg/m^2$ (obese). RESULTS: In the non-obese group, spirulina supplementation showed a significant lowering effect on plasma concentration of total cholesterol and LDL-cholesterol, a significant increase in interleukin (IL)-2 concentration (P < 0.01) and a significant increment (P < 0.05) in IL-2/IL-6 ratio, and a significant increase in total antioxidant status level and a significant decrease in thiobarbituric acid reactive substances level. However, these effects were not observed in the obese group. CONCLUSION: These results demonstrated that blood lipid lowering and immune and antioxidant improving response for spirulina supplement was affected by obesity in Korean elderly.

Studies on Anti-Mcirobial and Anti-Cancer Functions of Polysaccharide Extracted from Ganoderma lucidum (영지버섯 다당체의 항미생물작용 및 항암작용에 관한 연구)

  • 김성환
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.27 no.6
    • /
    • pp.1183-1188
    • /
    • 1998
  • This study was carried out to elucidate the immunomodulating activity of protein bound polysac charide extracted from Ganoderma lucidum(PSG). Macrophage drived reactive radicals were known as an effector for antimicrobial and anticancer functions. The promising immune response molecule, reactive oxygen intermediates(ROIs), was determined in TIB 71 cells with PSG at various experimental conditions. Treatment with 0.5mg PSG significantly increased the production of ROIs, superoxide anion as well as hydrogen peroxide, from TIB 71 cells(p<0.001). Under the same concentration, con siderable results were obtained from 24 hour cultivation with 106 cells at 5% CO2 incubator. The cells were trigged with PMA(5.3 M) after primed BCG(100 M) or IFN (100U) alone could not induce the production of ROIs, but it had a significant potentiating effect on ROIs secretion when the cells were treated with PSG.

  • PDF

The Polymer Membrane Electrode by Surfactants for Measuring Continuously Thiocyanate Ion in Wastewater (폐수중 티오시안산이온을 측정하기 위한 계면활성제를 이용한 고분자 막전극)

  • 최종석;안형환;강안수;우인성;황명환
    • Journal of the Korean Society of Safety
    • /
    • v.6 no.4
    • /
    • pp.13-20
    • /
    • 1991
  • Ion-selective electrode responsive to the thiocynate ion prepared by using the quaternary ammonium salts as a active material and PVC as a membrane matrix. The effect of chemical structure and composition of active material, and the membrane thickness on the linear response. the detection limit, and Nernstian slope of the electrode studied. Under the above optimum conditions of membrane, the effect of pH and the selectivity coefficients to various interfering anions were compared and investigated. It was concluded that the functions of thiocynate ion-selective electrode(ISE) were closely related to the chemical structure of the quaternary ammonium salts. The linear response, and the detection limit of the electrode potential increased with the increase of the carbon chain length of the alkyl group in the quaternary ammonium salts in the ascending order of Aliquat 336T, TOAT, TDAT, and TDDAT. The optimum membrane thickness was 0.3mm. The electrode characteristics was better with the decrease of the concentration of active material, and the best concentration was 3 weight percent. The membrane potential was independent of the pH variation in the region from pH 2 to 12. The order of the selectivity coefficients is as follows:Cl $O_4$$^{[-10]}$$I^{[-10]}$ >N $O_3$$^{[-10]}$ >B $r^{[-10]}$$F^{[-10]}$ >C $l^{[-10]}$ >O $A_{c}$ $^{[-10]}$ 〓S $O_4$$^{2-}$.

  • PDF

Immunosuppressive Characteristics of Oligomycin Derivatives Produced by Streptomyces lydicus MCY-524

  • Lee, Sang-Yong;Han, Sang-Bae;Kim, Hang-Sub;Kim, Young-Ho;Kim, Hwan-Mook;Kim, Chang-Jin;Hong, Soon-Duck;Lee, Jung-Joon
    • Journal of Microbiology and Biotechnology
    • /
    • v.7 no.1
    • /
    • pp.56-61
    • /
    • 1997
  • A strain producing immunosuppressive substances was isolated from a soil in Cheju island. By morphological, cultural, and physiological studies, the strain was identified as Streptomyces lydicus MCY-524. Cultured broth was purified by silica gel, sephadex LH-20 and preparative HPLC and gave two immunosuppressive compounds, MCH-22 and MCH-32. They dramatically suppressed the B cell activation with lipopolysaccharide, T cell activation by mixed lymphocyte response, and primary T-dependent antibody response at a final concentration of 1 ${\mu}g$/ml. They also markedly suppressed the proliferation of lymphocytes induced by lipopolysaccharide, pokeweed mitogen, and concanavaline A at the same concentration. Their suppressive activities, which were comparable to those of cyclosporin A, suggested that they were potent and broad immunotoxic agents on the immune functions of murine lymphocytes.

  • PDF

Optimization of the whole extract of Zarawand Mudaharaj (Aristolochia rotunda L.) root by Response Surface Methodology (RSM)

  • Ansari, MD Zakir;Sofi, Ghulamuddin;Hamiduddin, Hamiduddin;Ahmad, Haqeeq;Basri, Rabia;Alam, Abrar
    • CELLMED
    • /
    • v.11 no.3
    • /
    • pp.15.1-15.9
    • /
    • 2021
  • The chemical constitution of a drug has been accepted as an important basis for pharmacological action in Unani medicine. Various dosage forms have been developed on this concept, such as decoctions (Joshanda), infusions (Khesanda), extract (Rub / Usara), and syrup. Zarawand Mudaharaj (ZM.) / Aristolochia rotunda L. root was subjected to extraction process using Soxhlet's apparatus by using Response Surface Methodology (RSM) to design the number of random runs of the extracts with variation in the factors of temperature, the concentration of ethanol in water, time for extraction, for optimizing and maximizing the yield concentration. The data obtained, was analyzed with regression equation and ANOVA two-way summary to interpret the interaction of the factors for yield maximization. Minitab version 18 was used to design and analyze data. Validation of the optimum conditions for maximum yield of the whole extract of ZM. Root was carried out by re-run of the extract using the optimized conditions. The maximum yield percentage thus obtained using RSM was 20.87% whereas using these optimum conditions 21.35 % yield was obtained thereby validating the method. The association between the response functions and the process variables was identified by a three-factor recorded Box-Behnken design. In the present study RSM is used because itis a cheap and affordable method to optimize maximum yield percentage which may be reliably used by researchers. The study set in the surface conditions for ZM. root extraction by the Soxhlet apparatus for maximizing the yield percentage.

Effects of N-acetylcysteine (NAC) on chemiluminescence response as a non-specific immune parameter in Far Eastern catfish Silurus asotus (항산화물질 N-acetylcysteine (NAC)이 메기에서 비특이적 면역지표인 화학발광 반응에 미치는 영향)

  • Park, Kwan Ha;Lee, Han-Na;An, Jae-Young;Bae, Jun Sung;Lee, Chae Won;Yang, Chan Young;Choi, Sang-Hoon
    • Journal of fish pathology
    • /
    • v.32 no.1
    • /
    • pp.21-28
    • /
    • 2019
  • It has been reported that various anti-oxidant substances stimulate non-specific immune responses in fishes. In this study it was examined whether N-acetylcysteine (NAC), a precusor for anti-oxidant glutathione (GSH) synthesis, can modulate non-specific immune function in Far Eastern catfish Silurus asotus. Immune functions were assessed using the respiratory burst activity monitored by chemiluminescence (CL) responses in isolated leucocyte. NAC stimulated CL responses with doses of 10 or 100 mg/kg, but not with 1 mg/kg after 48 hr injection. It was observed with 10 mg/kg NAC that CL activity continued to elevate from 24 hr through 96 hr post-dosing, and returned to the near preinjection level by 10 days. To understand whether NAC can also activate CL activity in vitro, NAC was directly added to isolated catfish leucocytes. It was observed, however, that NAC can not stimulate CL at reasonable concentration ranges in vitro. As NAC is a precursor for the strong anti-oxidant glutathione (GSH), a putative immune stimulator, it was assessed whether GSH can also stimulate CL responses. Observed results show that GSH activated CL both in vivo and in vitro. The data obtained collectively support the proposition that NAC indirectly stimulates non-specific immune functions in catfish by enhancing GSH biosynthesis, but not by direct action of NAC. Such effects may have beneficial significance in aquaculture for practical utilization.

Effects of Atrial Natriuretic Peptide on Renal and Endocrine Functions in Spontaneously Hypertensive Rats (Spontaneously Hypertensive Rat에 있어서 Atrial Natriuretic Peptide의 신장기능과 몇가지 호르몬 분비에 미치는 영향)

  • Kim, San-Ho;Kim, Suhn-Hee;Seul, Kyung-Hwan;Cho, Kyung-Woo
    • The Korean Journal of Physiology
    • /
    • v.22 no.1
    • /
    • pp.41-53
    • /
    • 1988
  • The present study was undertaken to clarify the involvement of atrial natriuretic peptide in the development of hypertension in spontaneously hypertensive rats. Plasma concentration of immunoreactive atrial natriuretic peptide was higher in spontaneously hypertensive rats than in normotensive Sprague-Dawley and Wistar rats. Plasma renin concentration was lower in SHR than in normotensive rats, as observed in earlier experiments. Hydration-induced increase in urine flow and urinary excretions of sodium and potassium were smaller in SHR than in normotensive control rats. Intraarterial infusion of atrial natriuretic peptide resulted in increases in urine flow, urinary excretions of sodium and potassium in both hypertensive and normotensive rats. Renal response to atrial natriuretic peptide was markedly suppressed in SHR. Plasma renin and aldosterone concentration were suppressed by atrial natriuretic peptide in both SHR and normotensive rats. The responses were not significantly different in both groups. These results suggest that the renal responsiveness to atrial natriuretic peptide may be suppressed in SHR by some mechanisms still remaining obscure.

  • PDF