• 제목/요약/키워드: Retention loss

검색결과 328건 처리시간 0.027초

호기성 침지형 생물막법을 이용한 Polyester 감량폐수의 처리 (Treatment of Polyester Weight Loss Wastewater by Aerated Submerged Biofilm Process)

  • 박종웅;김대희
    • 한국환경보건학회지
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    • 제23권3호
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    • pp.85-90
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    • 1997
  • The objective of this study was to investigate biodegradation of TPA(terephthalic acid) and EG (ethylene glycol), treatment efficiency of polyester weight loss wastewater and microbial characteristics by aerated submerged biolfilm(ASB) p.rocess. In a batch reactor, pH increased from 7.0 to 8. 5 in the biodegradation of TPA. Whereas, in case of EG, decreased from 7.0 to 5.2. COD concentration rapidly decreased within 24hr in the biodegradation of TPA and EG. COD removal velocity constant(k) were 0.065-0.088 hr$^{-1}$. The biodegradation velocity of TPA was 1.4 times faster than that of EG. The ratio of suspended biomass to the total biomass in the reactor was 18.3-33.3%, increased as a high ratio of EG content. Biofilm thickness, biofilm dry density and attached biomass were 346-432 $\mu$m, 41.8-61.9 mg/cm$^3$, 1.45-2.67 mg/cm$^2$, respectively. There values increased as a high ratio of TPA content. In the hydraulic retention time of 36 hr, organic loading rate of 4 kgCOD/m$^3\cdot$ day and packing ratio of 70%, the effluent concentrations of TCOD, SCOD in a continuous flow reator were 1,388 mg/l, 147 mg/l and removal efficiencies were 77%, 97.6%, respectively.

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효과적인 토양유실 방지대책 수립을 위한 유사평가툴 (Enhanced Sediment Assessment Tool for Effective Erosion Control)

  • 임경재;;최예환;최중대;김기성;신용철;허성구;류창원
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.632-636
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    • 2005
  • Accelerated soil erosion is a worldwide problem because of its economic and environmental impacts. To effectively estimate soil erosion and to establish soil erosion management plans, many computer models have been developed and used. The Revised Universal Soil Loss Equation (RUSLE) has been used in many countries, and input parameter data for RUSLE have been well established over the years. However, the RUSLE cannot be used to estimate the sediment yield for a watershed. Thus, the GIS-based Sediment Assessment Tool for Effective Erosion Control (SATEEC) was developed to estimate soil loss and sediment yield for any location within a watershed using the RUSLE and a spatially distributed sediment delivery ratio. SATEEC was enhanced in this study by developing new modules to:1) simulate the effects of sediment retention basins on the receiving water bodies, 2) prepare input parameters for the Web-based sediment decision support system using a GIS interface. This easy-to-operate SATEEC system can be used to identify areas vulnerable to soil loss and to develop efficient soil erosion management plans.

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Effects of In Vitro Degradation on the Weight Loss and Tensile Properties of PLA/LPCL/HPCL Blend Fibers

  • Yoon Cheol Soo;Ji Dong Sun
    • Fibers and Polymers
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    • 제6권1호
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    • pp.13-18
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    • 2005
  • PLA/LPCL/HPCL blend fibers composed of poly (lactic acid) (PLA), low molecular weight poly ($\varepsilon$-caprolactone) (LPCL), and high molecular weight poly ($\varepsilon$-caprolactone) (HPCL) were prepared by melt blending and spinning for bioab­sorbable filament sutures. The effects of blending time and blend composition on the X-ray diffraction patterns and tensile properties of PLA/LPCL/HPCL blend fibers were characterized by WAXD and UTM. In addition, the effect of in vitro degra­dation on the weight loss and tensile properties of the blend fibers hydrolyzed during immersion in a phosphate buffer solu­tion at pH 7.4 and 37$^{\circ}C$ for 1-8 weeks was investigated. The peak intensities of PLA/LPCL/HPCL blend fibers in X-ray diffraction patterns decreased with an increase of blending time and LPCL contents in the blend fibers. The weight loss of PLA/LPCL/HPCL blend fibers increased with an increase of blending time, LPCL contents, and hydrolysis time while the tensile strength and modulus of the blend fibers decreased. The tensile strength and modulus of the blend fibers were also found to be increased with an increase of HPCL contents in the blend fibers. The optimum conditions to prepare PLA/LPCL/HPCL blend fibers for bioabsorbable sutures are LPCL contents of $5 wt\%, HPCL contents of $35 wt\%, and blending time of 30 min. The strength retention of the PLA/LPCL/HPCL blend fiber prepared under optimum conditions was about $93.5\% even at hydrolysis time of 2 weeks.

산욕 초기 산모의 체중 및 체성분 변화에 대한 연구 (A Study about Change of Body Weight and Body Composition during Early Puerperium)

  • 박장경;김동일
    • 대한한방부인과학회지
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    • 제23권4호
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    • pp.95-108
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    • 2010
  • Purpose: This study was to investigate the correlation among body weight, body composition, delivery method, parity, weight gain during pregnancy and obesity before pregnancy of patients who received postpartum care in one oriental medicine hospital. Mothods: From September 1, 2009 to August 31, 2008, we included 34 postpartum patients who had body composition analysis when admission and discharge among 47 postpartum patients who were hospitalized and received postpartum care in $\bigcirc\bigcirc$ University $\bigcirc\bigcirc$ Hospital. We used SPSS 14.0 for window to test for statistical significance. Results: After postpartum care, body weight and BMI of mothers was significantly decreased and the weight loss was almost body water. Mothers who had cesarean section had relatively severe edema and mothers who had been overweight before pregnancy had high BMI, body fat and abdominal fat. After delivery, body fat percentage was increased highly and body weight retention lasted long in mothers who had gained over 12.5kg during pregnancy. Conclusion: Living habits including diet has a significant effect on weight change of mothers during early puerperium, therefore it is required to teach mothers about breast-feeding, diet, and exercise to help their weight return to normal.

A COMPARATIVE STUDY OF THE PROTECTION OF DHAINCHA (Sesbania aculeata) SEED MEAL AND FISH MEAL FROM RUMEN DEGRADATION USING NYLON BAG TECHNIQUE

  • Hussain, M.;Chowdhury, B.;Siddiqua, A.;Routh, C.K.;Saadullah, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제6권2호
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    • pp.197-203
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    • 1993
  • The protection of dry matter and nitrogen from rumen degradation of dhaincha seed (Sesbania aculeate) meal was studied using nylon bag technique. The dhaincha seed meal was subjected to various heat treatments that included oven drying, autoclaving and boiling. Similar experiment was conducted with fish meal as reference for comparison. The oven-dried dhaincha meal was found to retain more dry matter and nitrogen than was found boiled or autoclaved meal. While autoclaving appeared to improve nitrogen and dry matter retention to some extent, boiling seemed to cause more loss of dry matter from nylon bag. Heat treatment caused high retention of nitrogen by fish meal. The calculated effective protein degradation was 80.4% and 83.2% for the oven dried fish meal and dhaincha seed meal whereas same values were 74.2% and 86.7% for autoclaved fish and dhaincha seed meal respectively at the outflow rate of 4.4% per hour. The in vitro study revealed higher digestibility for heat treated samples by pepsin. The dry matter, nitrogen and ash content of dhaincha seed meal were 85.93%, 5.93% and 7.31% respectively.

The Stability of Color and Antioxidant Compounds in Paprika (Capsicum annuum L.) Powder During the Drying and Storing Process

  • Park, Jae-Hee;Kim, Chang-Soon
    • Food Science and Biotechnology
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    • 제16권2호
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    • pp.187-192
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    • 2007
  • The objectives of this study were to examine changes in the color and antioxidant compounds of paprika powder under various conditions, as well as to establish the suitable conditions for drying and storage. Paprika was dried using the following methods: freeze-drying, vacuum drying, far infrared-ray drying, and hot-air drying. Measurements of the moisture content, color pigments, and antioxidant compounds (total carotenoids, capsanthin, ascorbic acid, and total polyphenols) were completed during 120 days of storage at 4 and $30^{\circ}C$. We found that drying methods, storage temperatures, and packaging materials affected the American Spice Trade Association (ASTA) and Hunter color values, as well as the antioxidant content of paprika powder. There was a high correlation (r=0.87, p<0.01) between the ASTA color and the $a^*/b^*$ value. The loss of red color was closely related to the reduction of moisture content (r=0.81, p<0.01) during storage. Drying paprika with a low temperature in the absence of air resulted in better retention of the carotenoids and ascorbic acid. Also, as the retention of the carotenoids and ascorbic acid increased, the stability of the red pigment increased. Freeze-drying was found to be the most suitable drying method for the stability of the antioxidant compounds and red pigment.

Implant overdenture using a locator bar system by drill and tapping technique in a mandible edentulous patient: a case report

  • Kim, Min-Su;Yoon, Mi-Jung;Huh, Jung-Bo;Jeon, Young-Chan;Jeong, Chang-Mo
    • The Journal of Advanced Prosthodontics
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    • 제4권2호
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    • pp.116-120
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    • 2012
  • Various options have been introduced for the selection of implant overdenture attachments. Attachment wear due to the repeated insertion and removal of dentures has caused problems such as decreased retention and the requirement for suprastructure remanufacturing. In these cases, a Locator bar system was applied using the drill and tapping technique to achieve total retrievability. In a 55-year-old female patient who showed three degrees of mobility in most of her teeth due to severe alveolar bone loss, a complete denture in the maxilla and an implant supported type overdenture in the mandible were planned after extracting all the remaining teeth. Six implants were placed from canine region to the distal molar region, and the locator was connected to the milled bar using the drill and tapping technique. For a 61-year-old female edentulous patient who complained of poor retention with old denture, a complete denture in the maxilla and an implant-tissue supported type overdenture in the mandible were planned. Four implants were placed in front of mental foramen, and the Locator was also connected to the Hader bar using the drill and tapping technique. With this technique, female parts can be easily replaced, and retention can be continuously maintained.

패류 가공에 관한 연구 -3. 개량조개 박편건제품의 제조 및 저장중의 색소 잔존율과 흡수율에 대하여- (Studies on the Shellfish Processing -3. The Pigment Retention and the Water Absorbing Capacity of Dehydrated Mashed Surf Clam Meat Flakes during Dehydration and Storage-)

  • 이응호;한봉호;허종화
    • 한국식품과학회지
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    • 제3권1호
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    • pp.48-51
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    • 1971
  • 토사질을 제거한 생 개량조개 육을 BHA, EDTA 또는 $NaHSO_3$를 각각 처리한 다음 갈아서 박편으로 열풍건조한 박편건제품의 제조 및 저장중에 있어서 이들의 처리가 박편건제품의 색소 소실 및 흡수율에 미치는 영향을 검토한 결과를 요약하면 다음과 같다. 1) 생개량조개를 갈아서 조개의 형태를 바꾸어 엷게 열풍건조 하므로서 조개의 원형 그대로 건조하는 것 보다 건조시간을 약1/2로 단축할 수 있었다. 2) BHA를 처리하여 박편으로 건조한 것은 다른 처리구와 비교할 때 박편건제품 제조 및 저장중에 색소 소실이 가장 적었다. 3) 박편건제품은 조개 형태 그대로 말린 제품 보다 흡수율이 약2배 높았다. 4) 박편건제품을 암실에 저장한 것은 햇빛이 닿는 곳에 저장한 것 보다 색소 소실도 적고 흡수율도 좋았다.

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Chemical Treatment of Short Fiber Fraction of OCC for Retention and Drainage

  • Youn, Hye-Jung;Chin, Seong-Min;Choi, Ik-Sun;Cho, Hui;Seo, Yung-Bum;Sohn, Chang-Man
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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    • pp.99-103
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    • 2006
  • Use of recycled fibers in papermaking has been increased for economical and environmental reasons. Recycled panels are major liber resources for brown grades and newsprints. Since the recycled fibers have disadvantageous properties as raw materials for papermaking it is of great importance to optimize the use of these recycled fibers. OCC (Old Corrugated Containers) is the major fiber source for linerboards and corrugating mediums that require diverse specification in strength properties. Many studies have been focused to overcome the problems of strength reduction of brown grades when recycled fibers are used as raw materials. The problem of strength loss for papers made from recycled fibers is closely associated with the increased amount of fines in recycled fibers and hornification of fibers. Fines contained in the recycled fiber resources cause problems not only in paper properties but also in process runnability. This shows that the optimal management and proper use of fines in recycling papermaking system are critical to get most benefits of using recycled fibers. In this study some approaches for optimal use of fiber fines in recycled paper mill have been investigated. Stock samples, prepared in the laboratory and obtained from a recycling plant were used. Fractionation of these samples was made using Sweco screen. And the effect of the addition of polyelectrolytes including cationic PAM and PEI on drainage and retention was evaluated. Different methods of polymer addition were compared to find the most effective ways of treating recycled fiber stocks with polyelectrolytes. Addition of polyelectrolytes to the short fiber fraction was most effective in retention and drainage. The influence of the charge and molecular weight of these two polymers has been examined and discussed.

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PLZT(10/y/z) 박막에서 Zr/Ti 농도에 따른 피로와 리텐션 특성 (Fatigue and Retention Characteristics of PLZT(10/y/z) Thin films with Various Zr/Ti Concentrations Ratio)

  • 정양희;강성준
    • 한국정보통신학회논문지
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    • 제9권3호
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    • pp.609-615
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    • 2005
  • Sol-gel 법을 이용하여 La를 $10mo1\%$로 고정시킨 PLZT(10/y/z) 박막을 제작하여 Zr/Ti 조성비에 따른 전기적 특성을 조사하였다. Zr/Ti 조성비에서 Ti 함유량이 증가함에 따라, 10kHz에서 비유전률은 550에서 400으로 감소된 반면, 유전손실은 0.028에서 0.053로 증가되었으며, 170kV/cm에서 누설전류밀도는 $1.64\times10^{-6}$에서 $1.26\times10^{-7}\;A/cm^2$으로 감소되었다. PLZT 박막의 이력곡선을 $\pm170kV/cm$에서 측정한 결과, Zr/Ti 조성비가 40/60에서 0/100로 변화함에 따라 PLZT 박막의 잔류분극과 항전계는 6.62에서 $12.86{\mu}C/cm^2$, 32.15에서 56.45kV/cm로 각각 증가되었다. $\pm5V$의 사각펄스를 $10^9$회 인가하여 피로특성을 측정한 결과, PLZT(10/40/60) 박막의 잔류분극은 초기분극 값으로부터 $50\%$ 감소된 반면, PLZT(10/0/100) 박막은 $28\%$ 감소되었다. 또, $10^5$초의 retention 측정 결과에서 PLZT(10/0/100) 박막은 초기분극 값에서 오직 $10\%$만이 감소된 반면, PLZT(10/40/60) 박막은 $40\%$ 감소되었다.