• Title/Summary/Keyword: cumulative duration

Search Result 194, Processing Time 0.02 seconds

Physiological Responses and Phytoextraction Potential of Pinus thunbergii on Cd-contaminated Soil

  • Han, Sim-Hee;Kim, Du-Hyun;Ultra, Venecio U. Jr.;Lee, Jae-Cheon
    • Journal of Korean Society of Forest Science
    • /
    • v.99 no.5
    • /
    • pp.711-719
    • /
    • 2010
  • We investigated physiological responses and phytoextraction ability of Pinus thunbergii in cadmium contaminated soil as part of our efforts in identifying plant materials for the restoration and revegetation of forest soil contaminated by heavy metals. Thirty seedlings (ten per treatment) were assigned to three treatments (control, 0.3 and 0.6 mM $CdSO_4$ solution) at first year experiment. At second year, ten seedlings per treatment treated with Cd during the first year experiment were divided by two groups (no Cd-treated and consecutive Cd-treated group). At first experiment, photosynthetic pigment content, and superoxide dismutase (SOD) and glutathione reductase (GR) activities have significantly reduced by Cd application, and the reduction rate was increased much higher as the rate of Cd application increased. On the other hand, thiol and malondialdehyde (MDA) content were significantly increased at the application of 0.6 mM of Cd. At the second year experiment, a general increase in chlorophyll and carotenoid content was observed with Cd treatment while SOD and GR activities showed a relative reduction compared to the control. Similar to the first year measurement, thiol and MDA contents also increased considerably due to Cd treatment. At harvest, dry matter was significantly reduced by Cd treatment especially at the rate of 0.6 mM Cd, but dry yield of P. thunbergii treated with 0.3 mM Cd was less affected and it was comparable with the control seedling. Cadmium concentration in seedling tissues increased with increasing Cd application rate while Cd uptake was higher in seedlings supplied with 0.3 mM Cd, which could be ascribed to their high dry matter. Overall, our study has demonstrated the unique physiological response of P. thunbergii to Cd-prolonged exposure by showing that the changes in photosynthetic pigment content and antioxidative enzyme activities were dependent on the concentration and duration of treatment. In addition, our results have demonstrated the potential of P. thunbergii to withstand up to 0.3 mM Cd (equivalent to cumulative Cd concentration of 134.4 to 268 mg $kg^{-1}$) without showing growth reduction, hence it might be used for phytoremediation of Cd contaminated areas.

Secular change of physical growth in Korean children and youth between 1999 and 2005 (아동 및 청소년 신체발육의 단기적 시대변화)

  • Kim, Myung;Kim, Hye-Kyeong;Matsuura, Yoshiyuki
    • Korean Journal of Health Education and Promotion
    • /
    • v.24 no.5
    • /
    • pp.69-85
    • /
    • 2007
  • Purpose: The purpose of this study is to clarify the traits of differences supposed as secular differences in physical growth between samples of children and youth in 1999 and 2005, and to identify the need of children and youth for health promotion. Methods: Two samples of different cohort were selected. The first one was consisted of 231 boys and 346 girls in 1999. And the other was consisted of 171 boys and 400 girls in 2005. Then the longitudinal growth distance data were collected from their cumulative health examination records. Results: The 2005 were larger in growth distances of stature, body weight, sitting height, and chest girth a at all ages from 6 to 16 in both boys and girls, so it could be concluded that a certain positive shift in growth process appeared in such a short duration. The 2005 were larger in growth velocity before peak age and also after peak age in body weight, but only in the term after peak age significant secular differences were found in stature for both sexes. As far as the growth distance concerned, the 2005 boys were ahead of the 1999 boys from 0.28-1.02 years and the 2005 girls from 0.32 to 0.81 years. In growth distance. Only in peak velocity, significant secular change was recognized in both sexes, any positive evidences of appearance of secular change were not found in peal age. In such derived physical indices as BMI, body weight index, sitting height index, and chest girth index, obvious evidences of secular change appearance were found.

Evaluation of clinical outcomes of implants placed into the maxillary sinus with a perforated sinus membrane: a retrospective study

  • Kim, Gwang-Seok;Lee, Jae-Wang;Chong, Jong-Hyon;Han, Jeong Joon;Jung, Seunggon;Kook, Min-Suk;Park, Hong-Ju;Ryu, Sun-Youl;Oh, Hee-Kyun
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.38
    • /
    • pp.50.1-50.6
    • /
    • 2016
  • Background: The aim of this study was to evaluate the clinical outcomes of implants that were placed within the maxillary sinus that has a perforated sinus membrane by the lateral window approach. Methods: We examined the medical records of the patients who had implants placed within the maxillary sinus that has a perforated sinus membrane by the lateral approach at the Department of Oral and Maxillofacial Surgery of Chonnam National University Dental Hospital from January 2009 to December 2015. There were 41 patients (male:female = 28:13). The mean age of patients was $57.2{\pm}7.2years$ at the time of operation (range, 20-76 years). The mean follow-up duration was 2.1 years (range, 0.5-5 years) after implant placement. Regarding the method of sinus elevation, only the lateral approach was included in this study. Results: Ninety-nine implants were placed in 41 patients whose sinus membranes were perforated during lateral approach. The perforated sinus membranes were repaired with a resorbable collagen membrane. Simultaneous implant placements with sinus bone grafting were performed in 37 patients, whereas delayed placements were done in four patients. The average residual bone height was $3.4{\pm}2.0mm$ in cases of simultaneous implant placement and $0.6{\pm}0.9mm$ in cases of delayed placement. Maxillary bone graft with implant placement, performed on the patients with a perforated maxillary sinus membrane did not fail, and the cumulative implant survival rate was 100%. Conclusions: In patients with perforations of the sinus mucosa, sinus elevation and implant placement are possible regardless of the location and size of membrane perforation. Repair using resorbable collagen membrane is a predictable and reliable technique.

A Method of Estimating the Volume of Exploitable Groundwater Considering Minimum Desirable Streamflow (최소하천유출량을 고려한 지하수 개발가능량 산정방안)

  • Chung, Il-Moon;Lee, Jeongwoo
    • The Journal of Engineering Geology
    • /
    • v.23 no.4
    • /
    • pp.375-380
    • /
    • 2013
  • The concept of safe yield places an emphasis on balancing groundwater withdrawal with groundwater recharge but ignores naturally occurring groundwater discharge. Because streams and their alluvial aquifers are closely linked in terms of water supply and water quality, to be properly understood and managed they must be considered together. Therefore, some districts in Kansas have reevaluated their safe-yield policies to account for natural groundwater discharge and stream-aquifer interactions by amending their safe-yield regulations to include a portion of baseflow as the minimum desirable streamflow (MDS). This study proposes a modified safe-yield policy in which the drought flow is chosen as the MDS. Baseflow separation was conducted from streamflow hydrograph and the results are presented as a flow-duration curve. The exploitable groundwater can be determined by subtracting MDS from the cumulative baseflow. This method was tested in the Musimcheon watershed, which was validated for streamflow using the SWAT-K model. The annually averaged exploitable groundwater in the whole watershed was estimated to be 86 mm. The exploitable groundwater amounts were also estimated for each subwatershed in the Musimcheon watershed.

Calculation of Rainfall Triggering Index (RTI) to Predict the Occurrence of Debris Flow (토석류 발생 예측을 위한 강우경보지수 산정)

  • Nam, Dong-Ho;Lee, Suk-Ho;Kim, Man-Il;Kim, Byung-Sik
    • The Journal of Engineering Geology
    • /
    • v.28 no.1
    • /
    • pp.47-59
    • /
    • 2018
  • At present, there has been a wide range of studies on debris flow in Korea, more specifically, on rainfall characteristics that trigger debris flow including rainfall intensity, rainfall duration, and preceding rainfall. the prediction of landslide / debris flow relies on the criteria for landslide watch and warning by the Korea Forest Service (KFS, 2012). Despite this, it has been found that most incidents of debris flow were caused by rainfall above the level of landslide watch, maximum hourly rainfall, extensive damage was caused even under the watch level. Under these circumstances, we calculated a rainfall triggering index (RTI) using the main factors that trigger debris flow-rainfall, rainfall intensity, and cumulative rainfall-to design a more sophisticated watch / warning criteria than those by the KFS. The RTI was classified into attention, caution, alert, and evacuation, and was assessed through the application of two debris flow incidents that occurred in Umyeon Mountain, Seoul, and Cheongju, Inje, causing serious damage and casualties. Moreover, we reviewed the feasibility of the RTI by comparing it with the KFS's landslide watch / warning criteria (KFS, 2012).

Development of Optical Frequency Modulated Fiber Optic Interferometric Sensor (광주파수 변조 광섬유 간섭형 센서의 개발)

  • Kwon, Il-Bum;Kim, Chi-Yeop;Kim, Min-Soo;Lee, Wang-Joo
    • Journal of Sensor Science and Technology
    • /
    • v.9 no.3
    • /
    • pp.163-170
    • /
    • 2000
  • Optical frequency modulated fiber optic interferometric sensor was developed to sense the mechanical quantities, such as displacement, strain, force etc. It has been difficult to distinguish whether the increase of the mechanical quantities or the decrease of the quantities measured by the conventional fiber optic interferometric sensors because their signals only have a sinusoidal wave pattern related to the change of mechanical quantities. In this study, in order to measure the mechanical quantifies with the distinction of the changing direction of the quantities, the fiber of optic Michelson interferometric sensor was simply constructed by the laser light modulated with saw tooth wave pattern. The output signal of the sensor was controlled as the sinusoidal wave. The signal processing was based on the counting of the wave number of the output signal during constant time duration. The strain was determined by the cumulative value of the wave number producted by the gage factor. In order to verify the strain measurement capability of this sensor, the strain increase-decrease test was performed by universal testing machine installed with the aluminum specimen bonded with the fiber optic sensor and electrical strain gage. In the result of the test, the strain from the fiber optic sensor had a good agreement with the values from the electrical strain gage.

  • PDF

The Durability of Geotextiles for Outdoor Exposure during the Construction of Solid Waste Landfill (폐기물 매립지 건설시 옥외 노출된 Geotextiles의 내구성에 관한 연구)

  • 고재학;이재영;전한용
    • Journal of Korea Soil Environment Society
    • /
    • v.5 no.1
    • /
    • pp.75-83
    • /
    • 2000
  • Recently, many landfills are constructed by using geosynthetics with earth materials. Geotextiles in geosynthetics are applied for the various purposes such as filters of the leachate collection and removal system and protectors of geomembrane liner. However geotextiles can be exposed to direct sunlight during the construction of landfill for several months. As you know the exposure of polymers to sunlight can be a major source of degradation of them. This study is to suggest a criteria on the installation of heavy weight geotextiles at the landfill. For this purpose, several different geotextiles were evaluated by outdoor exposure at two different locations and under the different seasons for one and half years. As the results of outdoor exposure, polypropylene geotextiles with 500g/$m^2$ and 700g/$\textrm{m}^2$were maintained around 40% of the initial strength during for one and half years. However, the polypropylene geotextile of 1000g/$\textrm{m}^2$showed 65% of the retained strength for the same duration of exposure. The retained strength of all polypropylene geotextile reduced dramatically with the cumulative sunshine radiation on a horizontal surface of around 1500MJ/$\textrm{m}^2$.

  • PDF

Numerical Study on Operating Factors Affecting Performance of Surfactant-Enhanced Aquifer Remediation Process (계면활성제 증진 대수층 복원 프로세스에 영향을 미치는 운영 인자들에 대한 수치 연구)

  • Lee, Kun-Sang
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.32 no.7
    • /
    • pp.690-698
    • /
    • 2010
  • Contamination of groundwater resources by organic chemicals has become an issue of increasing environmental concern. Surfactant-enhanced aquifer remediation (SEAR) is widely recognized as one of the most promising techniques to remediate organic contaminations in-situ. Solutions of surfactant or surfactant with polymer are used to dramatically expedite the process, which in turn, may reduce the treatment time of a site compared to use of water alone. In the design of surfactant-based technologies for remediation of organic contaminated aquifers, it is very important to have a considerable analysis using extensive numerical simulations prior to full-scale implementation. This study investigated the formation and flow of microemulsions during SEAR of organic-contaminated aquifer using the finite difference model UTCHEM, a three-dimensional, multicomponent, multiphase, compositional model. The remediation process variables considered in this study were the sequence of injection fluids, the injection and extraction rate, the concentrations of polymer in surfactant slug and chase water, and the duration of surfactant injection. For each variable, temporal changes in injection and production wells and spatial distributions of relative saturations in the organic phase were compared. Cleanup time and cumulative organic recovery were also quantified. The study would provide useful information to design strategies for the remediation of nonaqueous phase liquid-contaminated aquifers.

Development of Integrated Management System of Stormwater Retention and Treatment in Waterside Land for Urban Stream Environment (도시 하천 환경 관리를 위한 제외지 초기 강우 처리 및 저류 시설 종합 관리 시스템 개발)

  • Yin, Zhenhao;Koo, Youngmin;Lee, Eunhyoung;Seo, Dongil
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.37 no.2
    • /
    • pp.126-135
    • /
    • 2015
  • Increase of delivery effect of pollutant loads and surface runoff due to urbanization of catchment area results in serious environmental problems in receiving urban streams. This study aims to develop integrated stormwater management system to assist efficient urban stream flow and water quality control using information from the Storm Water Management Model (SWMM), real time water level and quality monitoring system and remote or automatic treatment facility control system. Based on field observations in the study site, most of the pollutant loads are flushed within 4 hours of the rainfall event. SWMM simulation results indicates that the treatment system can store up to 6 mm of cumulative rainfall in the study catchment area, and this means any type of normal rainfall situation can be treated using the system. Relationship between rainfall amount and fill time were developed for various rainfall duration for operation of stormwater treatment system in this study. This study can further provide inputs of river water quality model and thus can effectively assist integrated water resources management in urban catchment and streams.

Determinants of Opioid Efficiency in Cancer Pain: a Comprehensive Multivariate Analysis from a Tertiary Cancer Centre

  • Goksu, Sema Sezgin;Bozcuk, Hakan;Uysal, Mukremin;Ulukal, Ece;Ay, Seren;Karasu, Gaye;Soydas, Turker;Coskun, Hasan Senol;Ozdogan, Mustafa;Savas, Burhan
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.21
    • /
    • pp.9301-9305
    • /
    • 2014
  • Background: Pain is one of the most terrifying symptoms for cancer patients. Although most patients with cancer pain need opioids, complete relief of pain is hard to achieve. This study investigated the factors influencing persistent pain-free survival (PPFS) and opioid efficiency. Materials and Methods: A prospective study was conducted on 100 patients with cancer pain, hospitalized at the medical oncology clinic of Akdeniz University. Patient records were collected including patient demographics, the disease, treatment characteristics, and details of opioid usage. Pain intensity was measured using a patient self-reported visual analogue scale (VAS). The area under the curve (AUC) reflecting the pain load was calculated from daily VAS tables. PPFS, the primary measure of opioid efficacy, was described as the duration for which a patient reported a greater than or equal to two-point decline in their VAS for pain. Predictors of opioid efficacy were analysed using a multivariate analysis. Results: In the multivariate analysis, PPFS was associated with the AUC for pain (Exp (B)=0.39 (0.23-0.67), P=0.001), the cumulative opioid dosage used during hospitalisation (Exp (B)=1.00(0.99-1.00), P=0.003) and changes in the opioid dosage (Exp (B)=1.01 (1.00-1.01), P=0.016). The change in VAS score over the standard dosage of opioids was strongly associated with current cancer treatment (chemotherapy vs. others) (${\beta}=-0.31$, T=-2.81, P=0.007) and the VAS for pain at the time of hospitalisation (${\beta}=-0.34$, T=-3.07, P= 0.003). Conclusions: The pain load, opioid dosage, concurrent usage of chemotherapy and initial pain intensity correlate with the benefit received from opioids in cancer patients.