• Title/Summary/Keyword: De-concentration

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Nanofiltration of multi-ionic solutions: prediction of ions transport using the SEDE model

  • Cavaco Morao, A.I.;Szymczyk, A.;Fievet, P.;Brites Alves, A.M.
    • Membrane and Water Treatment
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    • v.1 no.2
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    • pp.139-158
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    • 2010
  • This work focuses on the application of nanofiltration (NF) to the concentration of a pharmaceutical product, Clavulanate ($CA^-$), from clarified fermentation broths, which show a complex composition with six main identified ions ($K^+$, $Cl^-$, ${NH_4}^+$, $H_2{PO_4}^-$, ${SO_4}^{2-}$ and $CA^-$), glucose and glycerol. The solutes transport through the NF membrane pores was investigated using the SEDE (Steric, Electric and Dielectric Exclusion) model. This model was applied to predict the rejection rates of the initial feed solution and the final concentrated solution (10-fold concentrated solution). The best results were achieved with a single fitted parameter, ${\varepsilon}_p$ (the dielectric constant of the solution inside pores) and considering that the membrane selectivity is governed by steric, electric (Donnan) and Born dielectric exclusion mechanisms. While the predicted intrinsic rejections of solutions comprising up to six ions and uncharged solutes were in good agreement with the experimental values, the deviations were much larger for the 10-fold concentrated solution.

Effect of tapered-end shape of FRP sheets on stress concentration in strengthened beams

  • Belakhdar, Khalil;Tounsi, Abdelouahed;Adda Bedia, El Abbes;Redha, Yeghnem
    • Steel and Composite Structures
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    • v.11 no.6
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    • pp.435-454
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    • 2011
  • Bonding composite materials to structural members for strengthening purpose has received a considerable attention in recent years. The major problem when using bonded FRP or steel plates to strengthen existing structures is the high interfacial stresses that may be built up near the plate ends which lead to premature failure of the structure. As a result, many researchers have developed several analytical methods to predict the interface performance of bonded repairs. In this paper, a numerical solution using finite - difference method is used to calculate the interfacial stress distribution in beams strengthened with FRP plate having a tapered ends with different thinning profiles. These latter, can significantly reduce the stress concentration. In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both beam and bonded plate. Numerical results from the present analysis are presented to demonstrate the advantages of use the tapers in design of strengthened beams.

Estimation of Service Life for Expressway Bridge Subjected to Chloride Ingress from De-icer (동절기 제설제 사용에 대한 고속도로 교량의 내구수명 평가)

  • Lee, Honam;Jeon, Chanki;Kim, Juho;Shim, Jaeyeong;Jeon, Inkyu
    • Journal of the Society of Disaster Information
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    • v.11 no.4
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    • pp.548-555
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    • 2015
  • This paper aims to estimate the service life of the target bridge structures subjected to chloride ingress from de-icer, which is used for safety of vehicles in winter, by investigating the chloride ingress into concrete. In this study, the 10-year-old bridge structures were investigated by measuring the chloride along the depth from the exposed surface to derive the surface chloride concentration and the diffusion coefficient for the prediction of service life. The service life of each measured point on the structures were estimated with the surface chloride concentration and the diffusion coefficient by using Life-365 software. As a result, it was estimated for all measured points to have over 100-year service life. Furthermore, the diffusion coefficient and the service life from the measured data were compared to another method calculated with the concrete mix, considering the time dependency of diffusion coefficient.

Production system influences color stability and lipid oxidation in gluteus medius muscle

  • Ana Paula Amaral de Alcantara Salim;Micheli da Silva Ferreira;Maria Lucia Guerra Monteiro;Loise Caroline Santos de Lima;Isabelle Trezze Marins Magalhaes;Carlos Adam Conte-Junior;Sergio Borges Mano
    • Animal Bioscience
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    • v.36 no.5
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    • pp.785-796
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    • 2023
  • Objective: We aimed to evaluate the color and oxidative stability of beef gluteus medius (GM) from cattle raised in organic and non-organic production systems. Methods: The GM samples (n = 10) were obtained from organic (ORG; n = 5) or nonorganic (NORG; n = 5) beef samples, sliced into 2.54-cm steaks, packaged in aerobic conditions, and stored for nine days at 4℃. ORG and NORG steaks were compared regarding myoglobin concentration, pH, instrumental color, delta E (ΔE), metmyoglobin reducing activity (MRA), and lipid oxidation on days 0, 5, and 9. Results: Feeding system did not influence (p>0.05) the myoglobin concentration. ORG steaks exhibited greater (p<0.05) meat pH, yellowness, and MRA, whereas NORG steaks exhibited greater (p<0.05) redness, chroma, R630/580, delta E, and lipid oxidation. ORG and NORG steaks exhibited similar (p>0.05) lightness and hue angle. During storage, ORG and NORG exhibited an increase in muscle pH, hue angle, and lipid oxidation; and a decrease (p<0.05) in redness, yellowness, chroma, and color stability (R630/580). Both samples exhibited a stable (p>0.05) pattern for lightness and MRA. Conclusion: Therefore, the production system can affect beef color and lipid stability during storage.

Susceptibility of Mice to Trypanosoma evansi Treated with Human Plasma Containing Different Concentrations of Apolipoprotein L-1

  • Da Silva, Aleksandro S.;Fanfa, Vinicius R.;Otto, Mateus A.;Gressler, Lucas T.;Tavares, Kaio C.S.;Lazarotto, Cicera R.;Tonin, Alexandre A.;Miletti, Luiz C.;Duarte, Marta M.M.F.;Monteiro, Silvia G.
    • Parasites, Hosts and Diseases
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    • v.49 no.4
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    • pp.427-430
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    • 2011
  • The aim of this study was to test the susceptibility of mice to Trypanosoma evansi treated with human plasma containing different concentrations of apolipoprotein L-1 (APOL1). For this experiment, a strain of T. evansi and human plasma (plasmas 1, 2, and 3) from 3 adult males clinically healthy were used. In vivo test used 50 mice divided in 5 groups (A to E) with 10 animals in each group. Animals of groups B to E were infected, and then treated with 0.2 ml of human plasma in the following outline: negative control (A), positive control (B), treatment with plasma 1 (C), treatment with plasma 2(D), and treatment with plasma 3 (E). Mice treated with human plasma showed an increase in longevity of $40.9{\pm}0.3$ (C), $20{\pm}9.0$ (D) and $35.6{\pm}9.3$ (E) days compared to the control group (B) which was $4.3{\pm}0.5$ days. The number of surviving mice and free of the parasite (blood smear and PCR negative) at the end of the experiment was 90%, 0%, and 60% for groups C, D, and E, respectively. The quantification of APOL1 was performed due to the large difference in the treatments that differed in the source plasma. In plasmas 1, 2, and 3 was detected the concentration of 194, 99, and 115 mg/dl of APOL1, respectively. However, we believe that this difference in the treatment efficiency is related to the level of APOL1 in plasmas.

Seasonal Variations of De-icing Salt Ions Harvested from Soils and Plants according to the Salt Damage of Pinus densiflora f. multicaulis on Roadsides (가로변 반송 염해정도에 따른 토양 및 식물체 내 염류이온의 계절별 변화)

  • Lee, Jae-Man;Park, Sun-Young;Yoon, Yong-Han;Ju, Jin-Hee
    • Journal of Environmental Science International
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    • v.29 no.4
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    • pp.395-402
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    • 2020
  • This study was conducted to analyze seasonal variations of de-icing salt ions harvested from soils and plants according to salt damage of Pinus densiflora f. multicaulis, a evergreen conifer, on roadsides. Pinus densiflora f. multicaulis was divided into three groups referred to SD, ND, and WD (serious salt damage (SD) = 71-100%, normal salt damage (ND) = 31-70%, and weak salt damage (WD) = 0-30%) based on the degree of visible foliage damage, and measured acidity (pH), electrical conductivity(EC), and de-icing salt ions (K+, Ca2+, Na+, and Mg2+) harvested from soils and plants. The results indicated that acidity, electrical conductivity, and de-icing salt ions of soils and plants were significantly affected by seasonal variation and salt damage. In addition, a strong positive liner relationship was observed in plants between the concentration of de-icing salts and salt damage in spring, while the relationship among seasonal variation and salt damage in soil were not significant. The results from this study has important implications for the management of conifer species in relation to salinity and roadsides maintenance.

Prediction of Non-Genotoxic Carcinogenicity Based on Genetic Profiles of Short Term Exposure Assays

  • Perez, Luis Orlando;Gonzalez-Jose, Rolando;Garcia, Pilar Peral
    • Toxicological Research
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    • v.32 no.4
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    • pp.289-300
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    • 2016
  • Non-genotoxic carcinogens are substances that induce tumorigenesis by non-mutagenic mechanisms and long term rodent bioassays are required to identify them. Recent studies have shown that transcription profiling can be applied to develop early identifiers for long term phenotypes. In this study, we used rat liver expression profiles from the NTP (National Toxicology Program, Research Triangle Park, USA) DrugMatrix Database to construct a gene classifier that can distinguish between non-genotoxic carcinogens and other chemicals. The model was based on short term exposure assays (3 days) and the training was limited to oxidative stressors, peroxisome proliferators and hormone modulators. Validation of the predictor was performed on independent toxicogenomic data (TG-GATEs, Toxicogenomics Project-Genomics Assisted Toxicity Evaluation System, Osaka, Japan). To build our model we performed Random Forests together with a recursive elimination algorithm (VarSelRF). Gene set enrichment analysis was employed for functional interpretation. A total of 770 microarrays comprising 96 different compounds were analyzed and a predictor of 54 genes was built. Prediction accuracy was 0.85 in the training set, 0.87 in the test set and increased with increasing concentration in the validation set: 0.6 at low dose, 0.7 at medium doses and 0.81 at high doses. Pathway analysis revealed gene prominence of cellular respiration, energy production and lipoprotein metabolism. The biggest target of toxicogenomics is accurately predict the toxicity of unknown drugs. In this analysis, we presented a classifier that can predict non-genotoxic carcinogenicity by using short term exposure assays. In this approach, dose level is critical when evaluating chemicals at early time points.

DeNOx Characteristics of Hybrid SNCR-SCR Process in a Pilot Scale Flow Reactor (파일럿 규모 반응기에서 Hybrid SNCR-SCR 공정의 질소산화물 저감 특성)

  • Eom, Won-Hyun;Yoo, Kyung-Seun;Kim, Sung-June
    • Korean Chemical Engineering Research
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    • v.49 no.1
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    • pp.89-94
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    • 2011
  • DeNOx characteristics of hybrid SNCR-SCR process have been investigated in a pilot scale flow reactor. DeNOx efficiency of SNCR reaction was about 80% at $970^{\circ}C$ and hybrid SNCR-SCR process showed 92% at $940^{\circ}C$ with NSR = 2.0. Compared to SNCR process alone, hybrid SNCR-SCR process was more effective at cool side, which is lower than $940{^{\circ}C}$. It should be also noted that ammonia slip from hybrid SNCR-SCR process was below 1ppm at the condition of higher space velocity and the required catalyst volume can be decreased to 2/3 of SCR process. Key factors for DeNOx efficiency of hybrid SNCR-SCR process were found to be $NH_3$ concentration and NOx selectivity of urea injected in SNCR process.

A Study on DeNOx Characteristics of Corona/Catalyst Hybrid System (코로나/촉매 일체형 시스템의 탈질특성에 관한 연구)

  • Chang, Hong-Ki;Choi, Chang-Sik;Shin, Jung-Uk;Ji, Young-Yeon;Hong, Min-Sun;Chung, Yoon-Jin
    • Journal of Korean Society for Atmospheric Environment
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    • v.23 no.6
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    • pp.699-707
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    • 2007
  • This study was carried out to investigate the reaction characteristics of corona/catalyst hybrid $DeNO_x$ process. The experiments were performed by using the multi-staged pin-to-hole type corona reactor which is enable to control the pin-to-hole gap and to insert the catalyst. Also, used for this study, were catalysts which commercially used Pt, Pd and $TiO_2$, and oxygen and hydrocarbon ($C_2H_4$) as reagents. In the syn-gas test, at high temperatures in the range of $100{\sim}200^{\circ}C$, the corona-only $DeNO_x$ process did not reduce the $NO_x$ concentration effectively. However in the presence of ethylene and oxygen as reagents, the $NO_x$ removal efficiency was better at these high temperatures than corona-only $DeNO_x$ process. In addition, coronal catalyst hybrid process with $TiO_2$ showed more efficiency of $NO_x$ removal than Pt and Pd catalyst, because the $TiO_2$ catalyst was more active than Pt and Pd catalyst to converse the $NO_2$ to $HNO_3$. Furthermore, at the condition of real diesel exhaust gas, the $DeNO_x$ efficiency of corona/catalyst hybrid process was not good at higher reaction temperature and plasma density.

Anti-inflammatory Effects of $1{\beta}$,$6{\alpha}$-Dihydroxyeudesm-4(15)-ene Isolated from Myrrh on LPS-induced Neuroinflammation in BV2 cells (몰약으로부터 분리된 $1{\beta}$,$6{\alpha}$-dihydroxyeudesm-4(15)-ene의 LPS로 유도된 BV2 미세아교세포에서의 항염증효과)

  • Kim, Dong-Cheol;Yoon, Chi-Su;Ko, Wonmin;Lee, Dong-Sung;Kim, Dae-Sung;Cho, Hyoung-Kwon;Seo, Jungwon;Kim, Sung Yeon;Oh, Hyuncheol;Kim, Youn-Chul
    • Korean Journal of Pharmacognosy
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    • v.46 no.1
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    • pp.12-16
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    • 2015
  • Myrrh is a resinous substance obtained from Commiphora trees, which has long been used as an antiseptic agent. A sesquiterpene, $1{\beta}$, $6{\alpha}$-dihydroxyeudesm-4(15)-ene (DE), was isolated from the hot water extract of Myrrh. In the present study, we found that DE attenuates the lipopolysaccharide (LPS)-induced inflammation in BV2 microglial cells. DE significantly inhibited LPS-induced production of pro-inflammatory mediators such as nitric oxide (NO) and prostaglandin $E_2$ ($PGE_2$) in BV2 microglia in a concentration-dependent manner without cytotoxic effect. Furthermore, DE dose-dependently suppressed the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). These results suggest that DE may be a good candidate to regulate LPS-induced inflammatory response.