scholarly journals Estimation of load capture ratio for evaluating LID facilities performance in Korea

2020 ◽  
Vol 20 (8) ◽  
pp. 3464-3477
Author(s):  
Jeonghyeon Choi ◽  
Sangdan Kim

Abstract Accurate performance evaluation is required for efficient design or installation of Low Impact Development (LID) facilities. However, the existing evaluation method in Korea needs to be improved since it has been derived for non-point reduction facilities. The purpose of this study is to propose a new design formula for three types of LID facilities. Through the long-term continuous simulation of EPA SWMM, the Load Capture Ratio (LCR) for LID facilities such as bio-retentions, infiltration trenches, and vegetative swales was estimated. As a result of the sensitivity analysis to verify the newly derived LCR formula, it can be seen that not only the regional rainfall characteristics but also the infiltration capacity of the native soil play an important role in the accuracy of the proposed LCR formula.

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1588 ◽  
Author(s):  
Kirti Sehgal ◽  
Jennifer Drake ◽  
Tim Seters ◽  
William Vander Linden

Permeable Interlocking Concrete Pavements (PICP) are a Low Impact Development (LID) technology that reduce the total volume of stormwater discharge and peak flows from urban hardscapes. Over time, particulates accumulate in the PICP joints, decreasing the pavement’s surface infiltration capacity and negatively affecting its overall functionality. Maintenance with two surface treatment technologies, a hand-held power brush and pressure washer-used in combination with vacuum street sweepers were compared to maintenance with vacuum street sweepers alone at four PICP parking lots. Both surface treatments along with vacuum street sweeping significantly improved the restoration of infiltration capacity for the young (i.e., <4 years) PICP section. Pressure washing in combination with vacuum sweeping was effective for PICP sections with larger (13–14 mm) joint openings. Power brushing, however, provided inconsistent results between the PICP sections. The effect of surface treatments was not significant for older (i.e., >6 years) installations with small (3–4 mm) joint openings. Though surface treatment resulted in significant improvement with a pressure washer and vacuum street sweeper combination, usage intensity of the parking lot was deemed as an important factor in restoring infiltration capacity. These findings re-emphasize that regular maintenance is essential to ensure long-term hydraulic functionality of PICP.


Author(s):  
Hao Xu ◽  
Liuxin Chen ◽  
Qiongfang Li ◽  
Jianchao Yang

Due to the continuous changes of political environment, consumption habits, technological progress and other factors, the external environment of enterprises is full of uncertainty. The turbulence of external environment is not conducive to the long-term operation and development of enterprises, but also brings great challenges to the selection of suppliers. This makes the competition of enterprises focus on how to choose long-term cooperation suppliers in the uncertain external environment. In addition, due to the deterioration of the global environment, governments pay more and more attention to environmental pollution, and consumers are more and more inclined to green consumption, which makes many companies pay more and more attention to environmental indicators when selecting suppliers. In the case of external environment turbulence and serious environmental pollution, the evaluation and selection of green suppliers in uncertain environment is particularly important for the long-term development of enterprises. What’s more, when the supplier’s capability gap is small, the decision-maker often hesitates among several suppliers. In this paper, the hesitant fuzzy is used to describe the hesitant psychology of decision-makers in selecting suppliers, the variance fluctuation is used to describe the characteristics of hesitant fuzzy numbers, and the probability is used to measure the uncertainty of the environment. A green supplier evaluation model under the uncertainty environment is proposed, which comprehensively evaluates the green suppliers under the uncertain environment. Furthermore, it is compared with other methods that do not consider the uncertainty and the adaptability of evaluation method and right confirmation method, so as to reflect the influence of uncertainty to green supplier evaluation and the importance of adaptability of evaluation method and right confirmation method.


2021 ◽  
Vol 13 (7) ◽  
pp. 1247
Author(s):  
Bowen Zhu ◽  
Xianhong Xie ◽  
Chuiyu Lu ◽  
Tianjie Lei ◽  
Yibing Wang ◽  
...  

Extreme hydrologic events are getting more frequent under a changing climate, and a reliable hydrological modeling framework is important to understand their mechanism. However, existing hydrological modeling frameworks are mostly constrained to a relatively coarse resolution, unrealistic input information, and insufficient evaluations, especially for the large domain, and they are, therefore, unable to address and reconstruct many of the water-related issues (e.g., flooding and drought). In this study, a 0.0625-degree (~6 km) resolution variable infiltration capacity (VIC) model developed for China from 1970 to 2016 was extensively evaluated against remote sensing and ground-based observations. A unique feature in this modeling framework is the incorporation of new remotely sensed vegetation and soil parameter dataset. To our knowledge, this constitutes the first application of VIC with such a long-term and fine resolution over a large domain, and more importantly, with a holistic system-evaluation leveraging the best available earth data. The evaluations using in-situ observations of streamflow, evapotranspiration (ET), and soil moisture (SM) indicate a great improvement. The simulations are also consistent with satellite remote sensing products of ET and SM, because the mean differences between the VIC ET and the remote sensing ET range from −2 to 2 mm/day, and the differences for SM of the top thin layer range from −2 to 3 mm. Therefore, this continental-scale hydrological modeling framework is reliable and accurate, which can be used for various applications including extreme hydrological event detections.


Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 239 ◽  
Author(s):  
Yuxia Li ◽  
J. N. Tullberg ◽  
D. M. Freebairn

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.


2014 ◽  
Vol 14 (5) ◽  
pp. 1283-1298 ◽  
Author(s):  
D. Lawrence ◽  
E. Paquet ◽  
J. Gailhard ◽  
A. K. Fleig

Abstract. Simulation methods for extreme flood estimation represent an important complement to statistical flood frequency analysis because a spectrum of catchment conditions potentially leading to extreme flows can be assessed. In this paper, stochastic, semi-continuous simulation is used to estimate extreme floods in three catchments located in Norway, all of which are characterised by flood regimes in which snowmelt often has a significant role. The simulations are based on SCHADEX, which couples a precipitation probabilistic model with a hydrological simulation such that an exhaustive set of catchment conditions and responses is simulated. The precipitation probabilistic model is conditioned by regional weather patterns, and a bottom–up classification procedure was used to define a set of weather patterns producing extreme precipitation in Norway. SCHADEX estimates for the 1000-year (Q1000) discharge are compared with those of several standard methods, including event-based and long-term simulations which use a single extreme precipitation sequence as input to a hydrological model, statistical flood frequency analysis based on the annual maximum series, and the GRADEX method. The comparison suggests that the combination of a precipitation probabilistic model with a long-term simulation of catchment conditions, including snowmelt, produces estimates for given return periods which are more in line with those based on statistical flood frequency analysis, as compared with the standard simulation methods, in two of the catchments. In the third case, the SCHADEX method gives higher estimates than statistical flood frequency analysis and further suggests that the seasonality of the most likely Q1000 events differs from that of the annual maximum flows. The semi-continuous stochastic simulation method highlights the importance of considering the joint probability of extreme precipitation, snowmelt rates and catchment saturation states when assigning return periods to floods estimated by precipitation-runoff methods. The SCHADEX methodology, as applied here, is dependent on observed discharge data for calibration of a hydrological model, and further study to extend its application to ungauged catchments would significantly enhance its versatility.


2021 ◽  
Vol 236 ◽  
pp. 02002
Author(s):  
Bingqi Jiao ◽  
Zhicheng Xu ◽  
Kuan Zheng ◽  
Xiaoqing Yan ◽  
Junshu Feng

In response to the climate change, it has been becoming the consensus of most countries in the world to accelerate the development of a high proportion of clean energy. The power grid is the core to support the development of a high proportion of clean energy, and the key is to accelerate the construction of clean power grids. This paper focuses on the main characteristics of clean power grid construction, and proposes a set of clean power grid development evaluation indicators including 5 first-level indicators and 19 second-level indicators and an analysis method based on radar charts. Taking China Power Grid as an example, this paper analyzes in detail the characteristics of the medium and long-term development mode of clean power grids and the relative change trends of specific indicators, and discusses the key links and potential problems that need attention in the development of clean power grids.


2021 ◽  
pp. 15-17
Author(s):  
Елена Анатольевна Юрова ◽  
Татьяна Викторовна Кобзева

Основной задачей для обеспечения качества функциональных продуктов длительного хранения является наличие методов оценки срока годности, применение которых позволит оценить не только качество продукта, но и его функциональные свойства на протяжении всего срока годности продукта. В настоящее время установлена возможность разработки методики ускоренного хранения для функциональных продуктов на молочной основе длительного хранения с применением метода ASLT и математического моделирования, исходя из имеющихся наработанных статистических данных по показателям окислительной порчи, содержанию свободных аминокислот и параметрам оценки продуктов гидролиза белка. В данной работе приведена оценка роли органолептического анализа при подтверждении срока годности продукции, рассмотрены основные процессы, влияющие на изменение органолептических характеристик при хранении. По результатам выполненной работы даны рекомендации по использованию метода органолептической оценки применительно к функциональным продуктам на молочной основе при использовании методики ускоренного хранения. The main task for ensuring the quality of functional shelf-stable products is the availability of methods for assessing the shelf life, the use of which will allow not only assessing the quality of the product, but also its functional properties throughout the entire shelf life of the product. Currently, the possibility of developing a method of accelerated storage for functional milk-based products for long-term storage using the ASLT method and mathematical modeling has been established, based on the available accumulated statistical data on indicators of oxidative spoilage, the content of free amino acids and parameters for evaluating protein hydrolysis products. This work evaluates the role of organoleptic analysis in confirming the shelf life of products, considers the main processes that affect the change in organoleptic characteristics during storage. Based on the results of the work performed, recommendations were given on the use of the method of organoleptic assessment in relation to functional milk-based products when using the accelerated storage method.


Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012618
Author(s):  
Grayson Beecher ◽  
Shahar Shelly ◽  
P. James B. Dyck ◽  
Michelle L. Mauermann ◽  
Jennifer M Martinez-Thompson ◽  
...  

Objectives:To longitudinally investigate patients with multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy, quantifying timing and location of sensory involvements in motor-onset patients, along with clinico-histopathological and electrophysiological findings to ascertain differences in patients with and without monoclonal gammopathy of uncertain significance (MGUS).Methods:Patients with MADSAM neuropathy seen at Mayo Clinic and tested for monoclonal gammopathy and ganglioside antibodies, were retrospectively reviewed (January 1st, 2007-December 31st, 2018).Results:Of 76 patients with MADSAM, 53% had pure motor, 16% pure sensory, 30% sensorimotor and 1% cranial nerve onsets. Motor-onset patients were initially diagnosed as multifocal motor neuropathy (MMN). MGUS occurred in 25% (89% IgM subtype), associating with ganglioside autoantibodies (p<0.001) and higher IgM titers (p<0.04). Median time to sensory involvements (confirmed by electrophysiology) in motor-onset patients was 18 months (range: 6-180). Compared to initial motor nerve involvements, subsequent sensory findings were within the same territory 35% (14/40), outside 20% (8/40), or both 45% (18/40). Brachial and lumbosacral plexus MRI was abnormal in 87% (34/39) and 84% (21/25), respectively, identifying hypertrophy and increased T2 signal predominantly in brachial plexus trunks (64%), divisions (69%), and cords (69%), and intrapelvic sciatic (64%) and femoral (44%) nerves. Proximal fascicular nerve biopsies (n=9) more frequently demonstrated onion-bulb pathology (p=0.001) and endoneurial inflammation (p=0.01) than distal biopsies (n=17). MRI and biopsy findings were similar amongst patient subgroups. Initial Inflammatory Neuropathy Cause and Treatment (INCAT) disability scores were higher in patients with MGUS relative to without (p=0.02). Long-term treatment responsiveness by INCAT score reduction ≥1 or motor Neuropathy Impairment Score (mNIS) >8 point reduction occurred in 75% (49/65) irrespective of MGUS or motor-onsets. Most required ongoing immunotherapy (86%). Patients with MGUS more commonly required dual-agent immunotherapy for stability (p=0.02).Discussion:Pure motor-onsets are the most common MADSAM presentation. Long-term follow-up, repeat electrophysiology and nerve pathology help distinguish motor-onset MADSAM from MMN. Better long-term immunotherapy responsiveness occurs in motor-onset MADSAM compared to MMN reports. Patients having MGUS commonly require dual immunotherapy.Classification of Evidence:This study provides Class II evidence that most clinical, electrophysiological, and histopathological findings were similar between patients with MADSAM with and without monoclonal gammopathy of unknown significance.


Author(s):  
Saurabh Dixit ◽  
Himanshu Katiyar ◽  
Arun Kumar Singh

There has been a paradigm shift in the field of mobile communication, with an overwhelming increase in data usage. As more and more users are migrating to smartphones, the amount of data being transmitted has increased. However, huge amounts of data and signal propagation are bound to be detrimental to the ecological balance. Long-term evolution (LTE), due to its flexibility and backward compatibility, has emerged as the network of choice for 4G and beyond. In this chapter, the significance of core technologies for LTE network is highlighted, along with the inherent advantage of reducing the energy consumption of cellular network. An energy-efficient design of LTE is proposed that blends the technologies proposed by 3GPP such as adaptive OFDMA with that of MU-MIMO.


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