scholarly journals Experiment and simulation of layered bioretention system for hydrological performance

2019 ◽  
Vol 9 (3) ◽  
pp. 319-329
Author(s):  
Chunbo Jiang ◽  
Jiake Li ◽  
Huaien Li ◽  
Yajiao Li
Keyword(s):  
Peak Flow ◽  
Reduction Rate ◽  
Infiltration Rate ◽  
Volume Reduction ◽  
Water Volume ◽  
Peak Time ◽  
Least Squares Regression ◽  
Storm Events ◽  
Infiltration Capacity ◽  
Submerged Area

Abstract Bioretention can reduce surface runoff, slow down peak flow, and delay peak time by increasing the infiltration capacity of the underlying surface. The media structure directly affects the performance of bioretention systems. Four pilot tanks with different media configuration were built, and hydraulics and water volume reduction were studied though intermittent, simulated storm events. The results showed that water volume and peak flow reduction rate were the most stable and efficient for #1 (fly ash mixing sand, 1:1 by volume) than other systems, which were 58.6–67.9% and 72.0–86.4%, respectively. Partial least squares regression (PLS) was used to build a model for the relation between water volume reduction rate and its influencing factors (R2 = 0.76), and the factors that influence bioretention water volume reduction were ranked from strongest to weakest as follows: infiltration rate (IR) > submerged area height (SAH) > inflow volume (IV) > antecedent dry time (ADT). In addition, volume reduction rate exhibited a positive correlation with ADT and SAH, and a negative correlation with IR and IV. Three water transfer simulations with different infiltration rates were conducted using HYDRUS-1D under designed inflow conditions, and the minimum relative error is obtained for #1.

Bioelectrical Impedance Analysis of Water Reduction in Lower-Limb Lymphedema by Lymphaticovenular Anastomosis

2018 ◽  
Vol 35 (04) ◽  
pp. 306-314 ◽  
Author(s):  
Yoshichika Yasunaga ◽  
Daisuke Yanagisawa ◽  
Erika Ohata ◽  
Kiyoshi Matsuo ◽  
Shunsuke Yuzuriha
Keyword(s):  
Lower Limb ◽  
Bioelectrical Impedance Analysis ◽  
Linear Regression Analysis ◽  
Reduction Rate ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Body Water ◽  
Volume Reduction ◽  
Water Volume ◽  
The Mean

Background Although lymphedema is fundamentally abnormal accumulation of excess water in the extracellular space, previous studies have evaluated the efficacy of physiological bypass surgery (lymphaticovenular anastomosis [LVA]) for lymphedema without measuring water volume. This study clarified the water reductive effect of LVA using bioelectrical impedance analysis (BIA). Methods The efficacy of LVA for unilateral lower-limb lymphedema was evaluated using BIA in a retrospective cohort. The water volume of affected and unaffected legs was measured using multifrequency BIA before and after LVA. Preoperative measurements were undertaken after compression therapy for at least 3 months. The follow-up period after LVA was a minimum of 6 months. Results Thirty consecutive patients with unilateral lower-limb lymphedema were enrolled. The mean water volume reduction of the affected leg by LVA (ΔLBW) was 0.86 L (standard deviation [SD]: 0.86, median: 0.65) with a mean number of 3.3 anastomoses (SD: 1.7). The mean reduction rate of edema was 45.1% (SD: 36.3). Multiple linear regression analysis revealed water volume difference between the affected and unaffected legs before LVA (excess LBW) as the strongest predictor of ΔLBW (R 2 = 0.759, p < 0.01; β = 0.500, p < 0.01). Conclusion The LVA reduces the volume of accumulated body water in lower-limb lymphedema. As excess LBW most strongly predicted the amount of water volume reduction by LVA, body water volume measurement by BIA before LVA might identify patients with low excess LBW not expected to benefit from LVA, regardless of apparent differences in limb circumference.

Water Reductive Effect of Lymphaticovenular Anastomosis on Upper-Limb Lymphedema: Bioelectrical Impedance Analysis and Comparison with Lower-Limb Lymphedema

2020 ◽  
Vol 36 (09) ◽  
pp. 660-666 ◽  
Author(s):  
Yoshichika Yasunaga ◽  
Daisuke Yanagisawa ◽  
Yuta Nakajima ◽  
Shinei Mimura ◽  
Miharu Kobayashi ◽  
...  
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Bioelectrical Impedance Analysis ◽  
Reduction Rate ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Volume Reduction ◽  
Water Volume ◽  
Arm Lymphedema ◽  
The Mean

Abstract Background We previously examined the water reductive effect of lymphaticovenular anastomosis (LVA) using bioelectrical impedance analysis (BIA) measurement on lower-limb lymphedema and revealed mean water volume reduction and edema reduction rate by leg LVA to be 0.86 L and 45.1%, respectively. This study aimed to clarify the water reductive effect of LVA on arm lymphedema and compare its results with those for leg lymphedema. Patients and Methods The efficacy of LVA for unilateral arm lymphedema was evaluated using BIA in a retrospective cohort. Limb circumference and arm body water volume (ABW) of the affected and unaffected arms were measured before and after LVA. Mean water volume reduction (ΔABW) and edema reduction rate by arm LVA were compared with values for leg LVA cited from our previous report as a historical control. Results Nineteen consecutive patients were enrolled. The mean ΔABW and edema reduction rate by BIA were 0.267 L and 46.0%, respectively. The decreasing rate of ABW by BIA was significantly larger than those of the upper extremity lymphedema index and sum of 5 circumferences measurement methods. ΔABW could be predicted by a regression line based on the preoperative water volume difference between affected and unaffected limbs. The mean edema reduction rates for arm and leg LVA were comparable. Conclusion The water reductive effect of LVA on upper-limb lymphedema was demonstrated by BIA assessment. BIA can reflect the effect of LVA more sensitively than conventional objective measurements and may facilitate the interpretation of LVA results. Although water volume reduction by arm LVA was less than that by leg LVA, the edema reduction rates were comparable.

scholarly journals Hillslope Contribution to the Clark Instantaneous Unit Hydrograph: Application to the Seolmacheon Basin, Korea

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1707
Author(s):  
Chulsang Yoo ◽  
Huy Phuong Doan ◽  
Changhyun Jun ◽  
Wooyoung Na
Keyword(s):  
Peak Flow ◽  
Peak Time ◽  
Rainfall Runoff ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Storage Coefficient ◽  
Channel Velocity ◽  
Linear Reservoir ◽  
Mountainous Basin

In this study, the time–area curve of an ellipse is analytically derived by considering flow velocities within both channel and hillslope. The Clark IUH is also derived analytically by solving the continuity equation with the input of the derived time–area curve to the linear reservoir. The derived Clark IUH is then evaluated by application to the Seolmacheon basin, a small mountainous basin in Korea. The findings in this study are summarized as follows. (1) The time–area curve of a basin can more realistically be derived by considering both the channel and hillslope velocities. The role of the hillslope velocity can also be easily confirmed by analyzing the derived time–area curve. (2) The analytically derived Clark IUH shows the relative roles of the hillslope velocity and the storage coefficient. Under the condition that the channel velocity remains unchanged, the hillslope velocity controls the runoff peak flow and the concentration time. On the other hand, the effect of the storage coefficient can be found in the runoff peak flow and peak time, as well as in the falling limb of the runoff hydrograph. These findings are also confirmed in the analysis of rainfall–runoff events of the Seolmacheon basin. (3) The effect of the hillslope velocity varies considerably depending on the rainfall events, which is also found to be mostly dependent upon the maximum rainfall intensity.

Traffic and residue cover effects on infiltration

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 239 ◽  
Author(s):  
Yuxia Li ◽  
J. N. Tullberg ◽  
D. M. Freebairn
Keyword(s):  
Conservation Tillage ◽  
Infiltration Rate ◽  
Farming System ◽  
Infiltration Capacity ◽  
Plant Available Water ◽  
The Impact ◽  
Reduced Time ◽  
Factor Governing ◽  
Controlled Traffic

Wheel traffic can lead to compaction and degradation of soil physical properties. This study, as part of a study of controlled traffic farming, assessed the impact of compaction from wheel traffic on soil that had not been trafficked for 5 years. A tractor of 40 kN rear axle weight was used to apply traffic at varying wheelslip on a clay soil with varying residue cover to simulate effects of traffic typical of grain production operations in the northern Australian grain belt. A rainfall simulator was used to determine infiltration characteristics. Wheel traffic significantly reduced time to ponding, steady infiltration rate, and total infiltration compared with non-wheeled soil, with or without residue cover. Non-wheeled soil had 4—5 times greater steady infiltration rate than wheeled soil, irrespective of residue cover. Wheelslip greater than 10% further reduced steady infiltration rate and total infiltration compared with that measured for self-propulsion wheeling (3% wheelslip) under residue-protected conditions. Where there was no compaction from wheel traffic, residue cover had a greater effect on infiltration capacity, with steady infiltration rate increasing proportionally with residue cover (R 2 = 0.98). Residue cover, however, had much less effect on inf iltration when wheeling was imposed. These results demonstrated that the infiltration rate for the non-wheeled soil under a controlled traffic zero-till system was similar to that of virgin soil. However, when the soil was wheeled by a medium tractor wheel, infiltration rate was reduced to that of long-term cropped soil. These results suggest that wheel traffic, rather than tillage and cropping, might be the major factor governing infiltration. The exclusion of wheel traffic under a controlled traffic farming system, combined with conservation tillage, provides a way to enhance the sustainability of cropping this soil for improved infiltration, increased plant-available water, and reduced runoff-driven soil erosion.

scholarly journals A Compact Weighing Lysimeter to Estimate the Water Infiltration Rate in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 180
Author(s):  
Laura Ávila-Dávila ◽  
Manuel Soler-Méndez ◽  
Carlos Francisco Bautista-Capetillo ◽  
Julián González-Trinidad ◽  
Hugo Enrique Júnez-Ferreira ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Field Capacity ◽  
Mass Conservation ◽  
Infiltration Rate ◽  
Vertical Movement ◽  
Water Infiltration ◽  
Infiltration Capacity ◽  
Silty Loam ◽  
Rain Events ◽  
Weighing Lysimeter

Infiltration estimation is made by tests such as concentric cylinders, which are prone to errors, such as the lateral movement under the ring. Several possibilities have been developed over the last decades to compensate these errors, which are based on physical, electronic, and mathematical principles. In this research, two approaches are proposed to measure the water infiltration rate in a silty loam soil by means of the mass values of a lysimeter weighing under rainfall conditions and different moisture contents. Based on the fact that with the lysimeter it is possible to determine acting soil flows very precisely, then with the help of mass conservation and assuming a downward vertical movement, 12 rain events were analyzed. In addition, it was possible to monitor the behavior of soil moisture and to establish the content at field capacity from the values of the weighing lysimeter, from which both approach are based. The infiltration rate of these events showed a variable rate at the beginning of the rainfall until reaching a maximum, to descend to a stable or basic rate. This basic infiltration rate was 1.49 ± 0.36 mm/h, and this is because soils with fine textures have reported low infiltration capacity. Four empirical or semi-empirical models of infiltration were calibrated with the values obtained with our approaches, showing a better fit with the Horton’s model.

scholarly journals Tumor Volume Reduction Rate to Induction Chemotherapy Is a Prognostic Factor for Locally Advanced Head and Neck Squamous Cell Carcinoma: a Retrospective Cohort Study

2021 ◽  
Author(s):  
Chi-hsien Huang ◽  
Ting-Chun Lin ◽  
Ming-Yu Lien ◽  
Fu-Ming Cheng ◽  
Kai-Chiun Li ◽  
...  
Keyword(s):  
Tumor Volume ◽  
Cox Regression ◽  
Reduction Rate ◽  
Volume Reduction ◽  
Cancer Site ◽  
Rank Test ◽  
Primary Cancer ◽  
Cox Regression Analysis ◽  
Log Rank Test ◽  
Tumor Volume Reduction

Abstract BackgroundAim of this study was to evaluate the prognostic of tumor volume reduction rate (TVRR) status post induction chemotherapy (IC) in LA-HNSCC.MethodsPatients with newly diagnosed LA-HNSCC from year 2007 to 2016 at a single center were included in this retrospective study. All patients had received IC as TPF (taxotere, platinum, fluorouracil) followed by daily definitive intensity-modulated radiotherapy (IMRT) for 70 Gy in 35 fractions concurrent with or without cisplatin-based chemotherapy. Tumor volume reduction rate of the primary tumor (TVRR-T) and lymph node (TVRR-N) was measured and calculated by contrast-enhanced CT images at diagnosis, and one month after final IC cycle, and analyzed though a univariate and multivariate Cox regression model.ResultsNinety patients of the primary cancer sites at hypopharynx (31/90, 34.4%), oropharynx (29/90, 32.2%), oral cavity (19/90, 21.1%) and larynx (11/90, 12.2%) were included in this study, with a median follow-up time interval of 3.9 years. In univariate Cox regression analysis, the TVRR-T as the only variable showed a significant difference for disease-free survival (DFS) (hazard ratio [HR] 0.77, 95% confidence interval (CI) 0.63 to 0.96; P = 0.02), aside from cancer site, RECIST, age and IC dose. In multivariate Cox regression analysis, The TVRR-T was also an independently significant prognostic factor for DFS (HR 0.77, 95% CI 0.62 to 0.97; P = 0.02). At a cutoff value using TVRR-T of 50% in Kaplan-Meier survival analysis, the DFS was significant higher with TVRR-T ≥ 50% group (log-rank test, p = 0.024), and also a trend of improved OS. (log-rank test, p = 0.069).ConclusionsTVRR-T was related to improved DFS and trend of improved OS. Other factors including patient’s age at diagnosis, the primary cancer site, and RECIST, were not significantly related to DFS.

scholarly journals Dependence Between Extreme Rainfall Events and the Seasonality and Bivariate Properties of Floods. A Continuous Distributed Physically-Based Approach

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1896 ◽  
Author(s):  
Gabriel-Martin ◽  
Sordo-Ward ◽  
Garrote ◽  
García
Keyword(s):  
Peak Flow ◽  
Total Duration ◽  
Weather Generator ◽  
Return Periods ◽  
Storm Events ◽  
Stochastic Weather Generator ◽  
Rainfall Events ◽  
Annual Peak ◽  
Extreme Flood ◽  
Physically Based

This paper focuses on proposing the minimum number of storms necessary to derive the extreme flood hydrographs accurately through event-based modelling. To do so, we analyzed the results obtained by coupling a continuous stochastic weather generator (the Advanced WEather GENerator) with a continuous distributed physically-based hydrological model (the TIN-based real-time integrated basin simulator), and by simulating 5000 years of hourly flow at the basin outlet. We modelled the outflows in a basin named Peacheater Creek located in Oklahoma, USA. Afterwards, we separated the independent rainfall events within the 5000 years of hourly weather forcing, and obtained the flood event associated to each storm from the continuous hourly flow. We ranked all the rainfall events within each year according to three criteria: Total depth, maximum intensity, and total duration. Finally, we compared the flood events obtained from the continuous simulation to those considering the N highest storm events per year according to the three criteria and by focusing on four different aspects: Magnitude and recurrence of the maximum annual peak-flow and volume, seasonality of floods, dependence among maximum peak-flows and volumes, and bivariate return periods. The main results are: (a) Considering the five largest total depth storms per year generates the maximum annual peak-flow and volume, with a probability of 94% and 99%, respectively and, for return periods higher than 50 years, the probability increases to 99% in both cases; (b) considering the five largest total depth storms per year the seasonality of flood is reproduced with an error of less than 4% and (c) bivariate properties between the peak-flow and volume are preserved, with an error on the estimation of the copula fitted of less than 2%.

scholarly journals Evaluating the performance of low impact development practices in urban runoff mitigation through distributed and combined implementation

2020 ◽  
Vol 22 (6) ◽  
pp. 1506-1520
Author(s):  
Sina Samouei ◽  
Mehmet Özger
Keyword(s):  
Low Impact Development ◽  
Drainage System ◽  
Infiltration Rate ◽  
Hydrologic Response ◽  
Impervious Surfaces ◽  
Storm Events ◽  
Rapid Urbanization ◽  
Urban Flood ◽  
Small Catchment ◽  
Runoff Reduction

Abstract Rapid urbanization and increasing impervious surfaces in cities lead to a serious reduction in infiltration rate of the surface and cause challenges in stormwater management. The Low Impact Development (LID) concept is considered as a potential solution for sustainable urban growth by contributing in urban flood mitigation. However, its effects on hydrologic response of the urbanized catchments, especially in broad scale implementation, are not fully understood and practically examined. In this study a hydrologic-hydraulic model of a small catchment was developed in EPA storm water management model (SWMM) program and calibrated and validated through field measurements. The hydrologic response of the catchment was investigated after replacing proportions of impervious surfaces with combinations of LID practices such as green roof, permeable pavement and bio-retention cell, through four land cover conversion scenarios and under five different designed storm events. The simulation results which are derived by comparison of outflow hydrographs between each scenario and conventional drainage system indicated that implementing 5–20% of LIDs has a noticeable impact on runoff peak flow and volume reduction, especially in storm events with shorter return periods. Also the runoff reduction trends show a linear response due to the increase in LID implementation ratio in the study area.

NIR Spectroscopy and Partial Least Squares Regression for the Determination of Phosphate Content and Viscosity Behaviour of Potato Starch

2001 ◽  
Vol 9 (2) ◽  
pp. 133-139 ◽  
Author(s):  
L.G. Thygesen ◽  
S.B. Engelsen ◽  
M.H. Madsen ◽  
O.B. Sørensen
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Partial Least Squares Regression ◽  
Near Infrared ◽  
Potato Starch ◽  
Nir Spectroscopy ◽  
Peak Time ◽  
Phosphate Content ◽  
Least Squares Regression ◽  
Data Prediction

A set of 97 potato starch samples with a phosphate content corresponding to a phosphorus content between 0.029 and 0.11 g per 100 g dry matter was analysed using a Rapid Visco Analyzer (RVA) and near infrared (NIR) spectroscopy, (700–2498 nm). NIR-based prediction of phosphate content was possible with a root mean square error of cross-validation ( RMSECV) of 0.006% using PLSR (partial least squares regression). However, the NIR/PLSR model relied on weak spectral signals, and was highly sensitive to sample preparation. The best prediction of phosphate content from the RVA viscograms was a linear regression model based on the RVA variable Breakdown, which gave a RMSECV of 0.008%. NIR/PLSR prediction of the RVA variables Peak viscosity and Breakdown was successful, probably because they were highly related to phosphate content in the present data. Prediction of the other RVA variables from NIR/PLSR was mediocre (Through, Final Viscosity) or not possible (Setback, Peak time, Pasting temperature).

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