Total Discharge Research Articles

Capturing Seismic Signals From Karst Aquifer Injection Experiments and a Natural Recharge Event

AbstractVariations in subsurface flow processes through a karst aquifer that feeds Bear Spring in southeastern Minnesota were captured on a temporary seismic network during injection experiments and a natural recharge event. Each experiment involved injecting ∼13,000 L of water into an overflow spring, and the natural event was triggered by a large rainstorm of ∼70 min in duration. During the injection experiments, the largest amplitude signals in the ground velocity seismograms occurred as the water first fell onto the rock at the overflow spring and as the large slug of water reached a sump or water‐filled passage. During the natural rainstorm event, the overflow spring began flowing and total spring discharge (perennial emanation points and the overflow spring) increased from ∼100 to 300 L/s. Seismic signals during and following the rain event include broadband noise from raindrops impacting the ground, as well as large amplitude signals while water levels rose; the latter occurred over a 5‐s period, producing multiple pulses of ground motion up to ∼0.5 mm/s. Based on seismic array analysis, high frequency signals during the natural recharge event and one of the injection experiments are largely sourced from south of the array, where a sump exists and the conduit orientation changes, but additional modeling is required to further understand which of a set of possible mechanisms is mostly likely the cause of these seismic signals.

A comparative technical study for estimating seeped water from irrigation canals in the Middle Egypt (Case study: El-Sont branch canal network)

Integrating with the national project of irrigation canal lining in the Egyptian countryside, the present study is introduced. The study presents a technical comparison of differential equations that are usually used for estimating the seeped water from the earthen irrigation canals. The quantities of irrigation water that are lost due to seepage are great enough to decrease the wide gap between the needed and available water quantities that Egypt seriously suffers from. So, the accurate estimation of the seeped water quantities is very important. The study aims to select the suitable seepage equations for the Egyptian soil, climate, and the currently used distributed irrigation system. It is also to assess the understudy network by estimating the lost water quantities due to seepage by using the designed water sections’ dimensions and comparing the results with those obtained using the existing field dimensions. In addition, to determining the agricultural area that can be added to the current served area after preserving such great quantities. From the Assiut countryside, the El-Sont canal and its network were chosen to be a case study. After a careful technical reading of the seepage equations that researchers introduced previously, the closest relationships to the case study were used. Results indicated that using the suggested relationship by Nazir Ahmed and the Indian equation, gave the maximum seepage quantities for the entire El-Sont canal network with about 21.5% of the total canal head discharge. Most of this lost water can be saved due to the implementation of the national project for irrigation canal lining. This large amount of preserved water can be used to irrigate 15% of the currently served area.

Analisis Karakteristik Aliran Irigasi Perforasi Pada Lahan Datar

Perforation irrigation is a unidirectional beam irrigation system that can be used for crop irrigation on dry land, due to the efficient use of water and the ability to wet land with a limited area. Therefore, the perforation irrigation system needs to be studied further in relation to the area of land that can be irrigated and the distribution of discharge to each perforated pipe. By testing several variations of the water level, the perforation irrigation emission capability will be obtained in the form of irrigation distribution, uniformity, emission capability and discharge amount used in irrigation on flat land. This study aims to determine the perforation irrigation capacity on flat land, the distribution of irrigation and the amount of discharge required. The test was carried out on three perforated pipes made of ½” PVC as lateral pipes, three transmission pipe length variations, such as 0.8m, 1m, and 1.2m with a distance between the perforations of 60 cm. The source of irrigation water comes from a 3 m tall tower with a capacity of ± 200 𝑙𝑖𝑡𝑒𝑟. The test uses three variations of head height, namely h1 350 cm, h2 360 cm, h3 370 cm and h4 380 cm. The results showed that the perforation irrigation jet length was around 100cm -120 cm, the uniformity of CU irrigation was above 97% with a total discharge on h1 QT = 0.689 lt/s, h2 QT = 0.690 lt/s , h3 QT = 0.695 lt/s and on h4 QT = 0.701 lt/s. While the range of flow rates for perforation 1 pipe Q1 (0.42 lt/s – 0.429 lt/s), perforation 2, Q2 (0.13 -0.145 lt/s) and perforation 3, Q3 (0.129 - 0.135 lt/s)

Incorporating experimentally derived streamflow contributions into model parameterization to improve discharge prediction

Abstract. Environmental tracers have been used to separate streamflow components for many years. They allow us to quantify the contribution of water originating from different sources, such as direct runoff from precipitation, subsurface storm flow, or groundwater to total streamflow at variable flow conditions. Although previous studies have explored the value of incorporating experimentally derived fractions of event and pre-event water into hydrological models, a thorough analysis of the value of incorporating hydrograph-separation-derived information on multiple streamflow components at varying flow conditions into model parameter estimation has not yet been performed. This study explores the value of such information to achieve more realistic simulations of catchment discharge. We use a modified version of the process-oriented HBV model that simulates catchment discharge through the interplay of hillslope, riparian-zone discharge, and groundwater discharge at a small forested catchment which is located in the mountainous north of South Korea, subject to a monsoon season between June and August. Applying a Monte-Carlo-based parameter estimation scheme and the Kling–Gupta efficiency (KGE) to compare discharge observations and simulations across two seasons (2013 and 2014), we show that the model is able to provide accurate simulations of catchment discharge (KGE ≥ 0.8) but fails to provide robust predictions and realistic estimates of the contribution of the different streamflow components. Using a simple framework that compares simulated and observed contributions of hillslope, riparian zone, and groundwater to total discharge during two sub-periods, we show that the precision of simulated streamflow components can be increased, while remaining with accurate discharge simulations. We further show that the additional information increases the identifiability of all model parameters and results in more robust predictions. Our study shows how tracer-derived information on streamflow contributions can be used to improve the simulation and predictions of streamflow at the catchment scale without adding additional complexity to the model. The complementary use of temporally resolved observations of streamflow components and modeling provides a promising direction to improve discharge prediction by representing model internal dynamics more realistically.

3D Numerical Analysis of a Phase Change Material Solidification Process Applied to a Latent Thermal Energy Storage System

The techniques for releasing thermal energy accumulated in periods of high availability to meet the demand in periods of low energy supply contribute to the continuity of the cycles involved in thermodynamic processes. In this context, phase change materials are capable of absorbing and releasing large amounts of energy in relatively short periods of time and under specific operating conditions. However, phase change materials have low thermal conductivity and need to be coupled with high-thermal-conductivity materials so that the heat flux can be intensified and the energy absorption and release times can be controlled. This work aims to numerically study the solidification process of a phase change material inserted into a triplex tube heat exchanger with finned copper walls to intensify the thermal exchange between the phase change material and the cooling heat transfer fluid, water, that will receive the energy accumulated in the material. This work proposes the 3D numerical modeling of the triplex tube heat exchanger with finned walls and meets the need for numerical models that allow for the analysis of the full geometry of the latent heat thermal energy storage system and the thermal and fluid dynamic phenomena that are influenced by this geometry. Results of the temperature, liquid fractions and velocity fields during phase transformations are presented, analyzed and validated with experimental data, presenting average errors of below 5%. The total material discharge time was approximately 168 min, necessary for the complete solidification of the phase change material, with water injected into the triplex tube heat exchanger at a flow rate of 8.3 L/min and a temperature of 68 °C. The solidification process occurred more slowly in the same direction as the length of the triplex tube heat exchanger, and from 80% of the material in the solid state, the difference between the solidification time for z = 0 and z = 480 mm was 30 min. The fluid dynamic conditions developed in the latent heat thermal energy storage system promoted a maximum negative heat flux of −6423 w/m2 to the annular internal surface and −742 w/m2 to the annular external surface, representing a heat removal process nine times less intense on the external surface. The total energy released to the cooling heat transfer fluid was 239.56 kJ/kg.

Estimation of potential nutrient fluxes from the Wadi Gaza catchment into the Mediterranean Sea with emphasis on flooding events

AbstractThe coastal catchment of Wadi Gaza is the main surface water basin that flows downstream to Gaza's coastal plain zone and drains into the Mediterranean Sea. The model-based assessment of the Wadi Gaza hydrological system is an essential endeavor for more efficient management of water resources and ensuring water security in terms of climate changes and anthropogenic processes. The hydrological simulation of the basin was performed using the SWAT model between 1984 and 2020. The outputs of the simulation predicted an average discharge that varies between zero in the summer months and about 15 m3/s in the winter with a maximum recorded discharge of about 130 m3/s. The model predicted average sediment and nutrient discharge to the sea as 3673, 177, and 62 tons per month of sediments, total nitrogen (TN), and total phosphorus (TP), respectively. The average dissolved inorganic nitrogen discharges were predicted to be 4, 13, and 1 tons per month for Nitrate (NO3), Ammonium (NH4), and Nitrogen dioxide (NO2), respectively during the rainy season. The constructed model is used to predict flood volumes and associated TN and TP for return periods (T) of 2, 25, 50, and 100 years. These return periods corresponded to total water discharges of 18, 91, 105, and 127 m3/s, respectively, accounting for 1,142, 5,773, 6,915, and 8,059 tons of TN, and 414, 2,092, 2,505, and 2,919 tons, of TP respectively.

A 5-year Retrospective Study of Burn Injury at Tarakan Regional General Hospital Jakarta

Introduction: Burn patients deserve more attention because of their high morbidity and mortality rates. According to the World Health Organization, approximately 180.000 deaths per year are associated with burns. We aim to obtain the characteristics of burn patients at Tarakan Regional General Hospital Jakarta as a type A referral center hospital from 2018 to 2022 to examine patient trends, provide appropriate services for burn patients, and reduce the rate of poor quality of life caused by disability and death. Methods: A cross-sectional method with descriptive study was used. Medical records of patients with burns admitted to Tarakan regional general hospital Jakarta between January 2018 and September 2022 were evaluated. 191 burn patients were reviewed based on age, sex, total burn surface area, burn degrees, etiology, intervention, and discharge status. Results: The total number of burn patients at the Tarakan hospital Jakarta from 2018 - 2022 was 191, with an increase of 248% from 2018 to 2022. With a gender ratio of 1.03:1, 97 subjects were male, and 94 were female. Most patients have dominated with adults as much as 80.1%. The highest incidence of burns is due to gas explosions, with a total area of burn injury at 21-30% TBSA occurring at 40.84%, and most burns ensue in the second degree as much as 59.69%. In the age group under 18 years, 73,05% of the common cause of burns is scald. The most extensive burns occur on 10-20% of the body surface area, and 73.68% of subjects suffer from second-degree burns. Debridement and wound dressing were done in the operating room on average four times per patient. The mortality rate in Tarakan Regional Hospital is 2.6% due to > 40% TBSA burns. Conclusion: Burn injury patients at Tarakan regional hospital Jakarta from 2018 to 2022 have increased, with gas explosions being the most common cause in the adult age group while in the children group by scald. Third-degree burns cause most deaths. According to these results, the proper facilities and infrastructure at hospitals in Jakarta may also improve the quality of treatment for burn patients.

Study on current-sharing characteristic of multi-pillar parallel arresters for DC transfer switch

Ultra high voltage direct current (UHVDC) system is the key support of power grid, which has an important impact on the development of China’s power grid. Direct current (DC) transfer switch is an indispensable component for UHVDC system, and its research is conducive to the development of the UHV DC transmission system. DC transfer switch is composed of breaking circuit, oscillation circuit and energy absorbing circuit. The energy absorbing circuit of DC transfer switch can absorb lots of energy by using arresters when DC is turn off, it can avoid the failure of DC breaking due to arc reburning. In order to meet the requirement of absorbing a large amount of energy, the arresters in the energy absorbing circuit generally adopts a multi pillars parallel structure. When multiple columns are connected in parallel, the uniform distribution of energy between different arresters columns becomes a very important problem. If the energy distribution difference is large, the arresters will overheat, aging and even explode. Thus, it is necessary to study the current-sharing characteristics. In this paper, the simulation and experiment are carried out in combination with the actual converter station. On the premise of total discharge energy in station, it is concluded that: The greater the deviation of volt–ampere characteristic curve from standard curve, the greater the non-uniformity coefficient and the greater the energy absorbed by single pillar arrester. The maximum energy absorbed by single arrester is 8.77 MJ, the non-standard curve by single pillar arrester should deviate from the standard curve by no more than 4%.

Evaluation of physicochemical and microbiological parameters, and their correlation in Himalayan Spring Water Systems: A case study of District Kulgam of Kashmir Valley, India, Western Himalaya.

Total coliforms, E. coli, and fecal streptococci are the important indicators linked to the human health. This study investigated presence of these indicator bacteria in the Himalayan springs at various locations in the district Kulgam of Kashmir valley. A total of 30 spring water samples were collected from rural, urban, and forest areas during post-melting season 2021 and pre-melting season 2022. The springs in the area originate from the alluvium deposit, Karewa, and hard rock formations. The physicochemical parameters were found within the acceptable limits. However, nitrate and phosphate were found above the permissible limit at few sites, thus indicating the presence of anthropogenic activities in the area. Majority of the samples during both the seasons were found highly loaded with total coliforms with maximum limit of greater than 180 MPN/100ml. E. coli and fecal streptococci were found in the range of less than 1 to more than 180 MPN/100ml. The results of Pearson correlation of physicochemical parameters with indicator bacteria showed that chemical oxygen demand, rainfall, spring discharge, nitrate, and phosphate are the main factors affecting the concentration of indicator bacteria in the spring water at each site. Principal component analysis showed the most influencing factors of water quality in most of the spring sites are total coliforms, E. coli, fecal streptococci, rainfall, discharge, and chemical oxygen demand. The results of this study showed that the spring water is unfit for drinking purpose because of high concentration of fecal indicator bacteria.

Substance flow analysis of arsenic and its discharge reduction in the steelworks

Although certain emission standards have been implemented to reduce the air pollution from the steel industry, heavy metal pollution associated with steel production in China has not been well addressed yet. Arsenic is a metalloid element, commonly present in various compounds in many minerals. When it presents in steelworks, it not only affects the quality of steel products, but also causes environmental consequences such as soil degradation, water contamination, air pollution and associated biodiversity loss and public health risks. At present, most of the studies on arsenic were limited to its removal in a certain process, while there has not been a thorough analysis of the flow path of arsenic in steelworks that can facilitate a more efficient removal from its lifecycle. To achieve this, we established a model to depict arsenic flows in steelworks for the first time using adapted substance flow analysis. Then, we further analyzed arsenic flows in the steelworks using a case study in China. Finally, input-output analysis was applied to study the arsenic flow network and explore the reduction potential of arsenic-containing wastes in steelworks. The results show that: 1) the arsenic in the steelworks comes from inputs of iron ore concentrate (55.31 %), coal (12.71 %) and steel scrap (18.67 %), while the outputs were hot rolled coil (65.93 %) and slag (33.03 %). 2) The input, circulation, and final product content of arsenic are 96.120, 32.510, and 66.946 g/t-CS, respectively, and the recycling rate of arsenic was 48.28 %, in the steelworks. 3) The total arsenic discharge from the steelworks is 34.826 g/t-CS. 97.33 % of arsenic is discharged in the form of solid waste. 4) The reduction potential of arsenic in wastes is 14.31 % in the steelworks by adopting low-arsenic raw materials and removing arsenic from processes.

A review of Open Channel Design for Mine Dewatering System Based on Environmental Observations

The purpose of mine dewatering system is to control runoff water that enters mine openings so that the mining process is not disturbed. The rainfall discharge (Q) is 0.0951 m³/second and the runoff discharge (Q) is 0.69 m³/second, making the total mining discharge entering the location 0.781 m³/second. The open channel design has dimensions of Channel wall slope (α) = 60°, Water depth (h) = 0.73 m, Channel depth (d) = 0.83 m, Channel base width (B) = 0.73 m, Surface width (b) = 1.57 m, Wet cross-sectional area of channel (A) = 0.92 m², and Channel wall length (a) = 0.97 m. The sedimentation pond has the following dimensions and compartments: Total length (l) = 104 m; width (b) = 8 m; depth (H) = 4 m; partition width = 4 m; partition depth = 4 m; partition length = 7 m. It consists of 3 compartments: conditioning compartment, separation between solids and mine water, and flow with an area of 277 m² per compartment. The sedimentation pond volume is 3094 m³ with a total area of 830 m². The results of the study obtained information that to control runoff water entering mine openings, a pond capacity as a settling site was needed of more than 3094 m³ with a maximum dredging time of settling pond particles that can be done once every 10 months.

Estimating the Role of Bank Flow to Stream Discharge Using a Combination of Baseflow Separation and Geochemistry

This study investigated the role of bank return flow to two medium size rivers in southeast Queensland using a combination of hydrograph separation techniques and geochemical baseflow separations. The main aims were to provide a case study to demonstrate spatial and temporal variability in groundwater contributions to two river systems in Southeast Victoria; the Avon River and the Mitchell River. The two rivers show large spatial and temporal variations in groundwater contributions with higher percentages during low flow periods and more surface runoff during wet years. At the end of the Australian millennium drought, groundwater discharge accounted for 60% of the total flow for the Avon River and 42% for the Michell River, whereas groundwater discharge only had a minor component to the total discharge in wetter years, ∼15% for the Avon River and only 3% for the Mitchell River. Radon and chloride were used for the geochemical baseflow separation and provide a means to separate regional groundwater discharge to the rivers from bank return flow. Bank return flow accounts for 2 to 5 times higher fluxes in certain areas. Geochemistry in combination with physical hydrogeology enhances the overall understanding of groundwater connected river systems over the river length.

Optimization for aerodynamic performance of double serpentine nozzles with spanwise offsets using Taguchi-based CFD analysis

Serpentine nozzles are widely used in combat aircraft to realize strong stealth characteristics. Based on the layout characteristics within a confined space, a series of double serpentine nozzles with spanwise offsets are established. Using computational fluid dynamics and Taguchi method, the influence mechanisms of the Distribution of Area (DA), Distributions of Centerline for the first and second ‘S’ sections in the Vertical direction (DCV1 and DCV2), and Distribution of Centerline in the Spanwise direction (DCS) are analyzed. The impact of these factors on the total pressure recovery coefficient can be ranked as DA > DCV2 > DCS > DCV1, whereas their impacts on the discharge coefficient and axial thrust coefficient can be ranked as DCV2 > DCS > DA > DCV1. Considering the statistical significance of these factors, a nozzle in which DA changes rapidly at the exit and DCV1, DCV2, and DCS change rapidly at the entrance gives the best aerodynamic performance. Compared to the worst configuration, the total pressure recovery coefficient, discharge coefficient, and axial thrust coefficient are improved by 1.6%,3.5% and 3.6%, respectively. DA influences the gas flow acceleration in the entire serpentine channel, resulting in different wall shear stress and friction losses. The various centerline distributions influence the gas flow acceleration effects and form complex wave structures in the constant-area extension section, resulting in different local and friction losses.

Synoptic and Seasonal Variability of Small River Plumes in the Northeastern Part of the Black Sea

Small river plumes are typical features at many coastal regions in the World Ocean. These water masses have relatively small areas and volumes; however, due to their energetic dynamics localized in a thin surface layer, they strongly affect coastal circulation, water quality, and ocean-atmosphere interaction. In this study, we investigate external factors, which govern synoptic and seasonal variability of small river plumes, and, therefore, affect land-ocean fluxes of fluvial water and biogeochemically important material. We use numerical modeling to simulate small river plumes at the northeastern part of the Black Sea. We describe the response time of small river plumes to changes in river discharge and wind forcing conditions, which determines variability of river plumes at different time scales. We reveal that the influence of river plumes on coastal processes depends not only on total annual river discharge volume, but also on temporal distribution of high-discharge and low-discharge periods. Seasonal and synoptic features of local atmospheric circulation could strongly modify the relation between river plume characteristics and river discharge rate. The results obtained in this study are important for better assessment of delivery and fate of river-borne suspended and dissolved matter, as well as floating litter in coastal areas.

Glacier contribution to lowland streamflow: A multi-year, daily geochemical hydrograph separation study in subarctic Alaska

Glacier melt water is a critical fresh water contribution of stream discharge for many regions and in high latitudes glacier extent is decreasing with climate warming. However, characteristics of glacierized contributions to subarctic watershed-scale geochemistry and runoff have attracted limited attention. Tracer studies of glacier dominated watersheds are also commonly limited to a few days. We conducted a six-year geochemical hydrograph separation study of melt season daily streamflow in a glacierized watershed in Interior Alaska to estimate glacier, rain, snow, and baseflow contributions. Bulk streamflow water samples were collected daily from the lowlands of Jarvis Creek (634 km2, 3.3% glacier cover) throughout the flow season (late April through September) during 2011–2016. Synoptic sampling of source waters included rain, snow, headwater late-winter streamflow and late-summer glacier terminus discharge. All 1227 source water and bulk streamflow samples were analyzed for stable water isotopes (δ18O and δD) and dissolved ion concentrations (SO42−:Cl− ratio). Bulk streamflow water samples exhibited large seasonal and inter-annual geochemical variation. Considerable inter-annual differences in stable water isotopes within each source water (δ18O values of −15.8 to −20.9‰ for rain, for example) emphasize the importance of informing the mixing model with source waters sampled during the same season as bulk streamflow collection. We estimated glacier discharge to be the largest seasonal contributor to total warm season lowland streamflow (average 35%, ranging from 20% in year 2016 to 44% in 2012) with daily variability from 2 (June 2, 2011) to 80% (September 10, 2013). If the glacier contribution were to cease completely, total warm season bulk stream discharge would be reduced by between 22 and 48% during an above or below average total seasonal rainfall, respectively, with up to an 80% reduction in peak flows. Results from this study suggest that high variability in source contribution of glacierized watersheds, extending across intra- and interannual timescales, challenge any generalization of hydrologic function derived from short-term studies.

Preliminary analysis of the cellulose-based battery separator

The worldwide energy demand is increasing due to the development of advanced technologies in various industries. Therefore, alternative and safe energy sources should be implemented in order to keep the environment clean and sustainable. Aluminum-air batteries have been recognized as a potential energy storage system candidate for the post lithium era. Unfortunately, serious corrosion of the anode in the aqueous aluminum-air battery will reduce the energy density. In this work, a novel idea of using cellulose-based separators for the Al-air battery is proposed to achieve a greener and cheaper battery. It was constructed by applying aluminum plate as an anode, activated carbon as an air–cathode, manganese oxide as electrocatalyst and sea water as the electrolyte. The performance of the self-fabricated water hyacinth cellulose nanofibrils separator is compared with the filter paper. The results showed that the performance of the water hyacinth cellulose nanofibrils separator with polyethylene glycol 400 binder in the ratio of 85 wt%:15 wt% is better than that of the commercial filter paper. The total discharge time is about 307.85 min using 10 mA of discharge current. The cellulose separator can be optimized to make a better aluminum-air battery.

Abstract WMP33: Cognitive Outcomes In Patients With A Prior History Of Stroke Participating In Inpatient Rehabilitation

Introduction: We sought to investigate the impact of prior stroke on cognitive improvement in stroke patients participating in inpatient rehabilitation. Methods: This was a retrospective review of clinical data from inpatient stroke rehabilitation (ISR) units collected from 09/2017- 08/2019. Age at onset, stroke type (ischemic or intracerebral hemorrhage (ICH)), therapy days, sex, and past medical history of stroke, diabetes, hypertension (HTN) were extracted as predictors of outcome in ISR. The baseline level of disability upon admission to acute stroke care was accounted for with pre-morbid modified Rankin scale (mRS) score and initial NIH Stroke Scale (NIHSS). The outcome variable of interest was total discharge cognitive functional independence measure (TDC-FIM) from ISR. FIM admission to ISR was controlled for in the model. Results: The data of 681 patients were used in a Lasso regression analysis (Figure 1), and of these patients there were 202 patients with a history of prior stroke. Univariate analysis showed a significant difference between prior stroke and first-time stroke groups with respect to pre-morbid mRS (p<0.001), initial NIHSS (p = 0.003), HTN (p=0.004), and stroke type (p=0.023). Lasso regression indicated that patients with diabetes had a 0.58 point decrease in TDC-FIM while those with HTN had a 0.38 point decrease as compared to patients who did not have these vascular risk factors. Patients with ischemic stroke type had a 0.73 point decrease in the TDC-FIM as compared to those who had an ICH. Prior stroke and the patient’s sex had no effect on TDC-FIM. The R-squared of the model was 0.74. Conclusion: By controlling for vascular risk factors, our findings show no difference in TDC-FIM with respect to prior stroke. This is different from prior studies that found prior stroke was associated with worse cognitive outcomes at discharge from ISR. Our results indicate that managing HTN and diabetes is imperative for post-stroke cognitive rehabilitation

Perencanaan Kebutuhan Pompa Untuk Sistem Dewatering Tambang Emas Desa Bakan Kabupaten Bolaang Mongondow

One of the most frequent problems in open pit mining methods is the presence of water puddles in the lowest elevation of the pit. This often causesthe delay of production activities.Therefore, it is a need to design a good drainage system planning to deal with it. In this regard, pumps were needed. The aim of this research was to determine the of needed pumps and the best type of pumps to remove water in the pit effectively. This research used maps of mining sequence planningwhich would be then analysed with software Surpac 6.5.1.This was to identifythe width of catchment area. Furthermore, the rainfall data wasanalysed using polygon Thiessen method. The next process is to determine the rainfall plan with Gumbel method. Next was to determine the rainfall intensity plan by using Mononobe equations. Following this was determine the total discharge using rational method. Finally, the process was ended with the determining of the pumps type and pumps spesification to dry the water puddles in the pit. the result indicated that in the sump of the 3rd quarter 2020 with 100 l / sec pumping flow, pumping time 14 hours, total head 76.26 m, recommended pump type is a Multiflo MFC 385 with a rotation speed of recommendation per minute of 1400-1500, and an efficiency of 60% -65%. For 4th quarter sump 2020 with 105l / sec pumping discharge, 20 hour pumping time, total head 105,91 m, recommended type of pump is Multiflo MFC 385 with rotation speed recommendation permenit 1600-1700, with efficiency 60%. For the 1st quarter sump 2021 with a pumping rate of 102 l/sec, the pumping time is 20 hours, total head is 122.26 m, the recommended type of pump is Multiflo MFC 385 with a rotation speed of recommendation per minute 1700-1800, with 50% -60% efficiency. It can be suggested that it is necessary to add one more pump, Multiflo MFC 385, for the dewatering pit process.

Detection of leakage in the plunge pool area at Xiluodu arch dam with an integrated approach

The Xiluodu arch dam is one of the highest dams in the world. A noticeable leakage having a maximum rate of 192 L/s and accounting for 46 ∼ 75 % of the total discharge at the site has been observed in the plunge pool area since impoundment. For long-term safety of the dam, an integrated approach of groundwater temperature analysis, hydrochemical data clustering, cross-correlation function and inverse modelling is presented to detect the sources and flow paths of the leakage. It is found that the leakage is originated from three major sources, i.e., the confined limestone aquifer (underlain by the unconfined basalt aquifer), the reservoir and the downstream river. The vertical leakage from the limestone aquifer occurs through unplugged boreholes drilled during site investigation. Inverse modelling shows that induced by particle filling, clogging and rock deformation, the effective permeability of the unplugged boreholes follows the same exponential decay with the near-field basalt rocks upstream the impervious system. Consequently, the amount of the vertical leakage decreases annually, which leads to an annual decrease of the discharge in the plunge pool area. The leakage from the reservoir and the downstream river is dynamically stable in magnitude, which occurs through the basalt aquifer by bypassing the grout curtains in the dam and subsidiary dam foundations, respectively. During the past seven years of operation, the proportions of leakage from the above three sources account for, on average, 44 %, 31 % and 25 %, respectively.

Opioid Overdose Risk Following Hospital Discharge Among Individuals Prescribed Long-Term Opioid Therapy: a Risk Interval Analysis.

Individuals prescribed long-term opioid therapy (LTOT) have increased risk of readmission and death after hospital discharge. The risk of opioid overdose during the immediate post-discharge time period is unknown. To examine the association between time since hospital discharge and opioid overdose among individuals prescribed LTOT. Self-controlled risk interval analysis. Adults prescribed LTOT with at least one hospital discharge at a safety-net health system and a non-profit healthcare organization in Colorado. We identified individuals prescribed LTOT who were discharged from January 2006 through June 2019. The outcome was a composite of fatal and non-fatal opioid overdoses during a 90-day post-discharge observation period, identified using electronic health record (EHR) and vital statistics data. Risk intervals included days 0-6 after index and subsequent hospital discharges. Control intervals ranged from days 7 to 89 after index discharge and included all other time during the observation period that did not fall within a risk interval or time readmitted during a subsequent hospitalization, which was excluded. Poisson regression was used to estimate incidence rate ratios (IRR) and 95% confidence intervals (CI) for overdose events during risk in comparison to control intervals. We identified 7695 adults (63.3% over 55 years, 59.4% female, 20.3% Hispanic) who experienced 9499 total discharges during the study period. Twenty-one overdoses occurred during their observation periods (1174 per 100,000 person-years [9 in risk, 12 in control]). Overdose risk was significantly higher during the risk interval in comparison to the control interval (IRR 6.92; 95% CI 2.92-16.43). During the first 7 days after hospital discharge, individuals prescribed LTOT appear to be at elevated risk for opioid overdose. Clarifying mechanisms of overdose risk may help inform in-hospital and post-discharge prevention strategies.