• Title/Summary/Keyword: total rejection

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Performance of fouled NF membrane as used for textile dyeing wastewater

  • Abdel-Fatah, Mona A.;Khater, E.M.H.;Hafez, A.I.;Shaaban, A.F.
    • Membrane and Water Treatment
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    • v.11 no.2
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    • pp.111-121
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    • 2020
  • The fouling of Nanofiltration membrane (NF) was examined using wastewater containing reactive black dye RB5 of 1500 Pt/Co color concentrations with 16890 mg/l TDS collected from El-alamia Company for Dying and Weaving in Egypt. The NF-unit was operated at constant pressure of 10 bars, temperature of 25℃, and flowrate of 420 L/min. SEM, EDX, and FTIR were used for fouling characterization. Using the ROIFA-4 program, the total inorganic fouling load was 1.07 mM/kg present as 49.3% Carbonates, 10.1% Sulfates, 37.2% Silicates, 37.2% Phosphates, and 0.93% Iron oxides. The permeate flux, recovery, salt rejection and mass transfer coefficients of the dye molecules were reduced significantly after fouling. The results clearly demonstrate that the fouling had detrimental effect on membrane performance in dye removal, as indicated by a sharp decrease in permeate flux and dye recovery 68%. The dye mass transfer coefficient was dropped dramatically by 34%, and the salt permeability increased by 14%. In this study, all the properties of the membrane used and the fouling that caused its poor condition are identified. Another study was conducted to regeneration fouled membrane again by chemical methods in another article (Abdel-Fatah et al. 2017).

Characteristic of Induction Motor Drives Fed by Three Leg and Five Leg Inverters

  • Talib, Md. Hairul Nizam;Ibrahim, Zulkifilie;Rahim, Nasrudin Abd.;Hasim, Ahmad Shukri Abu
    • Journal of Power Electronics
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    • v.13 no.5
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    • pp.806-813
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    • 2013
  • This paper aims to compare the performance of three phase induction motor drives using Five Leg Inverter (FLI) and Three Leg Inverter (TLI) configurations. An Indirect Field Oriented Control (IFOC) method using a TLI is well established and incorporated for high performance speed drives in various industries. The FLI dual motor drive system on the other hand shows good workability in the independent control of two induction motor drives simultaneously. In this experiment, the IFOC method is utilized for both drive systems, and Space Vector Pulse Width Modulation (SVPWM) is used to generate pulses for both inverters. For the FLI, the Double Zero Sequence (DZS) Injection technique is used to generate the modulation signal. The complete experiment setup is done by using a DSpace 1103 controller board. The individual motor performances are analyzed using similar schemes, equipment setups and controller parameter values. The results show similar speed performance response capability between the single motor operation using a TLI system and the two motor operation using a FLI system based on the variable speed range either in forward or reverse operation. They also show similar load rejection abilities. However, the single motor with a TLI has a better power quality aspect such as ripple current and total harmonics distortion (THD).

A Survey of Actual Guides for Children to Take the Oriental Medicine in the Oriental Clinics & the Oriental Hospitals (한의원과 한방병원에서 행해지고 있는 소아에 대한 한약복약지도 현황 조사 연구)

  • Lee, Su Jeong;Lee, Seung Yeon;Yu, Sun Ae
    • The Journal of Pediatrics of Korean Medicine
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    • v.27 no.3
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    • pp.12-19
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    • 2013
  • Objectives Children's unique taste bud often gives them difficult time to take oriental medicines. To overcome, survey was conducted focusing on useful and practical tips on how to take them. Methods The survey was carried out by posting mail questionnaire. Target clinics for the survey were selected by the internet search engine, Google, Daum, and Naver, and typing in "oriental treatment + pediatrics", "pediatrics + oriental medicine", "pediatric oriental clinic". 24 clinics were searched, but they were further narrowed down to the specialized pediatric oriental clinics. Also, total of 38 inquiry leaflets were distributed to 14 University Oriental Hospitals. Results If children refuse to take the medicine, mixture with sweeteners can be prescribed for them. Among them, oligosaccharide is the most recommended followed by sugar and honey. To avoid rejection to medication, use of different formulation, such as distillation medicine, soft X-Section, granulated medicine, and character printing can be used. Conclusions The most effective method is to investigate the mixture first, and then the alternative formulations.

Morphology control in PVDF membranes using PEG/PVP additives and mixed solvents

  • Rajabi, Shima;Khodadadi, Foroogh;Mohammadi, Toraj;Tavakolmoghadam, Maryam;Rekabdar, Fatemeh
    • Membrane and Water Treatment
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    • v.11 no.4
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    • pp.237-245
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    • 2020
  • The effects of the mixed two solvents, Dimethylacetamide (DMAc) and Dimethylformamide (DMF), and Polyethylene glycol (PEG) and Polyvinylpyrrolidone (PVP) as additives on performance of Polyvinylidene fluoride (PVDF) membranes were studied. Initially, PEG200 was used as a primary additive at fixed percentage of 5% wt. PVP was then blended with PEG200 in different concentrations. PVDF and DMAc were used as polymer and solvent in the casting solutions, respectively. To control the diffusion rate of PVP in the presence of PEG200 and PVP blend, mixtures of DMAc and DMF were used as the mixed solvent in the casting solutions. Asymmetric PVDF membranes were prepared via phase inversion process in a water bath and the effects of two additives and two solvents on the membrane morphology, pure water flux (PWF), hydrophilicity and rejection (R) were investigated. Attenuated Total Reflection Fourier Transform Infrared Spectra (ATR-FTIR) analysis was used to show the residual PVP on the surface of the membranes. Atomic Force Microscopy (AFM) was utilized to determine roughness of membrane surface. The use of mixed solvents in the casting solution resulted in reduction of PVP diffusion rate and increment of PEG diffusion rate. Eventually, PWF and R values reduced, while porosity and hydrophilicity increased.

The Effects of Mothers' Depression and Parenting Behavior on Preschoolers' Externalizing Problem Behaviors (어머니의 우울과 양육행동이 유아의 외현화 문제행동에 미치는 영향)

  • Doh, Hyun-Sim;Shin, Nana;Park, Bo-Kyung;Kim, Min-Jung;Kim, Hye-In
    • Korean Journal of Child Studies
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    • v.35 no.4
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    • pp.179-198
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    • 2014
  • The main purpose of this study was to examine direct and indirect effects of mothers' depression on preschoolers' externalizing problem behaviors. A total of 155 mothers with preschoolers aged 3 and 4 years (83 boys and 72 girls) living in Seoul participated in this study. Mothers completed questionnaires on mothers' depression, parenting behavior, and preschoolers' externalizing problem behaviors. Direct and indirect pathways from mothers' depression to preschoolers' externalizing problem behaviors were analyzed using Structural Equation Modeling (SEM). First, it was revealed that mothers' depression did not directly affect preschoolers' externalizing problem behaviors. Second, mothers' depression indirectly influenced preschoolers' externalizing problem behaviors through mothers' parenting behavior. Mothers who reported higher levels of depression showed less warmth/acceptance and more rejection/restriction towards their children, which led to higher levels of preschoolers' externalizing problem behaviors. These findings emphasize the importance of positive parenting by mothers in reducing preschoolers' problem behaviors.

Job Burnout of Restaurant Employees in Daegu City - With a Focus on 'Family-Work Conflict', 'Work-Family Conflict', Job Satisfaction, and Individual Job Performance - (대구 외식업 종사원의 직무소진에 관한 연구 - '가족-일 갈등', '일-가족 갈등', 직무만족 및 개인직무성과를 중심으로 -)

  • Ha, Dong-Hyun
    • Journal of the Korean Society of Food Culture
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    • v.26 no.3
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    • pp.261-270
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    • 2011
  • The purpose of this study was to investigate the relationship between 'family-work conflict/work-family conflict', job burnout, job satisfaction, and individual job performance in the employees at the restaurants in Daegu City. The sample of this study consisted of employees at the restaurants in Daegu City who visited the 2010 Daegu Food Tour Expo between October 7 and October 10. A total of 302 questionnaires were analyzed using statistical methods of factor analysis, reliability test, and covariance structural analysis. The research findings were as follows; firstly, work-family conflict was positively related to job burnout, secondly, job burnout was negatively related to job satisfaction and individual job performance and thirdly, job satisfaction was positively related to individual job performance. However, there was no relationship between family-work conflict and job burnout. The reason for rejection of the relationship between family-work conflict and job burnout was that family-related affairs were not important enough to affect job burnout among restaurant employees in Korea. This phenomenon happened differently in the US. Therefore, currently, restaurant managers in Daegu City should pay much attention to work-related affairs so as to mitigate job burnout as much as possible among their employees.

Proximate Composition and Quality Characteristics of Bread with Black Rice Flour (흑미가루를 첨가하여 제조한 식빵의 일반성분 및 품질 특성)

  • Kim, Young-Mo
    • The Korean Journal of Food And Nutrition
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    • v.31 no.1
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    • pp.94-103
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    • 2018
  • The quality characteristics of bread with black rice flour were investigated to find the most preferred ratio of black rice flour. Its moisture, ash content, crude protein, crude fat, amino acids, and texture were analyzed. A sensory evaluation was also performed. The moisture and crude fat of bread with black rice flour were decreased in proportion to the added amount of black rice flour, but the crude protein and ash content were increased. The volume of bread decreased as the added amount of black rice flour increased. The pH value of bread increased in proportion to the added amount of black rice flour. The value of brightness and yellowness of the dough were the highest in the control. The added amount of black rice flour was negatively correlated with the brightness and the yellowness of the dough, but was positively correlated with the redness. Total free amino acids were found, and the dough with 5% black rice flour contained the highest amount, followed by 3%, 2%, and 1%. When evaluating the storage days, the springiness and cohesiveness of bread with black rice flour they decreased with time, but the chewiness and brittleness increased. Regarding the taste, preference was given to the bread with 2% black rice flour, which had the lowest rejection rate and was not affected by time in any meaningful sense. The bread with 2% black rice flour won the highest scores in the overall preference measurement.

Effect of Periodic Water-back-flushing Time ad Period in Water Treatment by Tubular Alumina Ceramic Microfiltration

  • Park, Jin-Yong;Lee, A-Reum
    • Korean Membrane Journal
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    • v.10 no.1
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    • pp.33-38
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    • 2008
  • In this study periodic water-back-flushing using permeate water was performed to minimize membrane fouling and to enhance permeate flux in tubular ceramic micro filtration system for Gongji stream water treatment in Chuncheon city. The filtration time (FT) 2 min with periodic 6 sec water-back-flushing showed the highest value of dimensionless permeate flux ($J/J_0$), and the lowest value of resistance of membrane fouling ($R_f$), and we acquired the highest total permeate volume ($V_T$) of 7.44L. Also in the results of BT effect at fixed FT 10 min, BT (back-flushing time) 20 sec showed the lowest value of $R_f$ and the highest value of $J/J_0$, and we could be obtained the highest $V_T$ of 8.04 L. Consequently FT 10 min and BT 20 sec could be the optimal condition in Gongji stream water treatment. Then the average rejection rates of pollutants by our tubular ceramic MF system were 93.8% for Turbidity, 20.7% for $COD_{Mn}$, 39.2% for $NH_3$-N and 31.5% for T-P.

The Relationship between Mother-Toddler Interaction and Its Related Variables (걸음마기 자녀를 둔 어머니의 모-아 상호작용과 관련변인 간의 관계)

  • Chung, Mira;Yee, Bangsil;Kwon, Jeongyoon;Park, Sukyung;Kang, Eunyoung
    • Korean Journal of Human Ecology
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    • v.21 no.4
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    • pp.715-728
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    • 2012
  • This research aims at examining the relationships between mother-toddler interaction and its related variables. A total of 49 toddlers and their mothers were participated and observed in the child lab during free play. The main results of this study are as follows. First, among the mother-toddler interaction, 'involvement' was frequently used in comparison with the 'rejection' was the hardly used in their interaction. Second, the mothers' sensitivity, parenting stress, and the mother-toddler interaction had no significant difference by the mothers' job status or gender of toddlers. However, their parenting stress was lower in working mothers or mothers who have girls. Third, mother-toddler interaction was significantly correlated with the mothers' sensitivity, parenting stress, parenting style, and the temperament of toddlers. On the basis of this results, the implication related to the variables influencing mother-toddler interaction was discussed.

The Role of Geological and Geomorphological Factors in the Delimitation of Maritime Boundaries (해양경계획정에서 지질 및 지형적 요소의 효과에 관한 고찰)

  • Yang, Hee-Cheol;Park, Seong-Wook;Jeong, Hyeon-Su;Yi, Hi-Il
    • Ocean and Polar Research
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    • v.29 no.1
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    • pp.55-67
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    • 2007
  • A reference to natural prolongation appeared for the first time in the North Sea Judgement. Although it was not suggested that the concept of natural prolongation would automatically allow for the fixing of a continental shelf boundary, that concept encouraged States to request international tribunals to determine continental shelf boundaries on the basis of the geological and geomorphological features of the seabed. In the Libya v. Malta Case, however, the rejection of geological and geomorphological factors was total. Especially, Natural prolongation was the then checkmated as a relevant fact in delimitation between coasts situated less than 400 nm. apart. There can be no doubt that, in several disputed cases, prominent geomorphological variations are simply ignored ; nevertheless, there are also a few agreements where geological and geomorphological characteristics come into play and, to a certain extent, affect maritime boundaries. Physical characteristics of sea-bed are generally given serious consideration in the boundary delimitation such as the final negotiated boundary of the Australia-Indonesia Continental Shelf boundary Agreement(Timor and Arafura seas) which follows the continental slope bordering the Timor Trench.