Normal Inflow Research Articles

Water use optimization of Benel Reservoir in Jembrana Regency, Bali Province

Benel Reservoir has a storage capacity of 1.71 million cubic meters (MCM) and has been supplying water for irrigation purposes. In line with population growth, the Benel Reservoir is projected to be capable of meeting the domestic water demand in the Jembrana Regency. As a result, this research aimed to determine the optimal water use in the Benel Reservoir for irrigation and domestic uses. The irrigation water requirements are necessary for an area of 1,047.3 hectares, while the domestic water demands are 64 l/s. F.J Mock Method of rainfall-runoff model is used to calculate water availability using 10 years of daily rainfall data and has been calibrated using observed discharged data from the Benel water level gauge station. The optimization model is formulated using linear programming. During wet years, the optimization result for water utilization with inflow discharge yields a cropping intensity value of 300%. The cropping intensity value of 287.50% in the scenario of normal inflow discharge. Furthermore, the cropping intensity value is 275% in the case of dry-year inflow discharge. Irrigation and domestic water demand met the minimum value limit of 0.70 and 0.85 for the k-factor. The reliability in supplying irrigation and domestic water reached 100%.

Prediction of water inflow and analysis of surrounding rock stability in unfavorable geological mountain tunnel

During the construction of a mountain tunnel, water inflow and rock instability are common occurrences due to unfavorable geological conditions, posing serious threats to construction safety. This study focuses on a proposed mountain tunnel and employs multiple formulas to predict potential water inflow during excavation. Based on the amount of water inflow and deformation of surrounding rocks, comprehensive determinations are made for the thickness of grouting rings and permeability coefficients. The results demonstrate that: 1) Different formulas yield slightly varied outcomes but overall trends remain consistent; considering various calculations, the normal water inflow for this tunnel is approximately 115.5908×103 m3/d with a maximum at 210.9100×103 m3/d 2) Increasing grouting ring thickness or decreasing permeability coefficient can effectively reduce water inflow, but the reduction range is gradually narrowed. 3) Pre-grouting curtains have an evident effect in enhancing stability; however, their effectiveness decreases with increased thickness. 4) Taking into account both safety and economic factors, it is recommended that the grouting ring thickness be set at 8 m with a permeability coefficient equaling one 100th that of surrounding rocks for this tunnel project.

Microbial-derived Urolithin A Targets GLS1 to Inhibit Glutaminolysis and Attenuate Cirrhotic Portal Hypertension

Background and AimsCirrhotic portal hypertension (CPH) is the leading cause of mortality in patients with cirrhosis. Over 50% patients with CPH treated with current clinical pharmacotherapy still present variceal bleeding or sometimes death owing to insufficient reduction in portal pressure. Elevated intrahepatic vascular resistance (IHVR) plays a fundamental role in increasing portal pressure. Because of its potent effect in reducing portal pressure and maintaining normal portal inflow to preserve liver function, lowering the IHVR is acknowledged as an optimal anti-CPH strategy but without clinical drugs. We aimed to investigate the protective effect of microbial-derived Urolithin A (UroA) in IHVR and CPH. MethodsCCl4 or BDL surgery was administered to mice to induce liver fibrosis and CPH. 16S rRNA gene sequencing was used for microbial analysis. Transcriptomics and metabolomics analyses were employed to study the host and cell responses. ResultsUroA was remarkably deficient in patients with CPH and was negatively correlated with disease severity. UroA deficiency was also confirmed in CPH mice and was associated with a reduced abundance of UroA-producing bacterial strain (Lactobacillus murinus, L. murinus). Glutaminolysis of hepatic stellate cells (HSCs) was identified as a previously unrecognized target of UroA. UroA inhibited the activity of glutaminase1 to suppress glutaminolysis, which counteracted fibrogenesis and contraction of HSCs and ameliorated CPH by relieving IHVR. Supplementation with UroA or L. murinus effectively ameliorated CPH in mice. ConclusionsWe for the first time identify the deficiency of gut microbial metabolite UroA as an important cause of CPH. We demonstrate that UroA exerts an excellent anti-CPH effect by suppressing HSC glutaminolysis to lower the IHVR, which highlighted its great potential as a novel therapeutic agent for CPH.

Active galactic nuclei feedback in an elliptical galaxy (III): the impacts and fate of cosmological inflow

ABSTRACT The cosmological inflow of a galaxy is speculated to be able to enter the galaxy and enhance the star formation rate (SFR) and black hole accretion rate (BHAR). In this paper, by performing high-resolution hydrodynamic simulations in the framework of macer, we investigate the fate of the inflow and its impacts on the evolution of a massive elliptical galaxy. The inflow properties are adopted from the cosmological simulation IllustrisTNG. We find that the inflow gas hardly enters but is blocked beyond ∼20 kpc from the central galaxy and becomes part of the circumgalactic medium (CGM). The gas pressure gradient, mainly contributed by the thermalized stellar wind and subdominant contributed by the energy input from the active galactic nuclei (AGNs), balances gravity and prevents the inflow from entering the galaxy. The SFR and BHAR are almost not affected by the normal inflow. However, if the rate of cosmological inflow were increased by a factor of 3, a small fraction of the inflow would enter the galaxy and contribute about 10 per cent of the gas in the galaxy. In this case, the gas density in the galaxy would increase by a factor of $\gtrsim$20. This increase is not because of the additional gas supply by the inflow but due to the increase of gas density and pressure in the CGM caused by the inflow. Consequently, the SFR and BHAR would increase by a factor of ∼5 and ∼1000, respectively. Finally, AGN feedback can perturb the motion of the inflow and heat the CGM through its intermittent outbursts.

Effect of the leading-edge protuberances on the aeroacoustic and aerodynamic performances of the wind turbine airfoil

Based on the restraining effect of the leading-edge protuberances (LEPs) on flow separation, this work focuses analyzing the aeroacoustic and aerodynamic performances for the wind turbine airfoil with LEPs near the outboard region of the blades, by using the experimental testing and numerical calculation methods. The associated flow patterns for the aeroacoustic and aerodynamic performances are revealed within the pre-stall and post-stall regions. The shedding of the separation vortices enhances the instability of the laminar boundary layer, generating the aerodynamic noise from the wind turbine airfoil. The LEPs suppress the generation of the tonal noise in pre-stall region by changing the distribution and reducing the intensity of the trailing edge shedding vortices. Moreover, LEPs can improve the aerodynamic performance of the wind turbine airfoil greatly by inhibiting the flow separation at a high inflow angle of attack. As a flow control method for the wind turbine blades, LEPs will help to improve the aeroacoustic performance of the blades under normal inflow wind conditions, and the aerodynamic performance under extreme wind situations where the inflow wind changes on a large scale frequently.

A normal pattern of mitral inflow predicts a better prognosis following cardiovascular events in early advanced-age patients

Although a mitral inflow pattern usually changes from a normal pattern to an abnormal relaxation pattern as part of the aging process in healthy people, some early advanced-age individuals maintain a normal pattern. We investigated whether a normal pattern of mitral inflow predicts a better prognosis following cardiovascular (CV) events in early advanced-age patients. We enrolled 425 patients aged 60–65 years with 0.6 < E/A < 1.5. Patients were divided according to their mitral inflow pattern, i.e., a normal pattern group (E/A ≥ 1.0, n = 77) and an abnormal relaxation pattern group (E/A < 1, n = 348), and were evaluated the relationship with CV events. Multivariate regression analysis found that the normal inflow pattern was associated with odds ratios of 0.859 for body mass index (BMI; 95% confidence interval [CI]: 0.778–0.937), 0.529 for hypertension (0.303–0.924), and 0.325 for heart rate (0.228–0.463). During the follow-up period (4.9 ± 1.8 years), the adjusted-hazard ratio was significantly lower in the normal pattern group (HR: 0.119, 95% CI 0.016–0.910). Kaplan–Meier curves showed a higher event-free rate for the normal pattern group than for the abnormal relaxation pattern group (p = 0.0292). Normal inflow pattern in early advanced-age patients predicts a better prognosis following CV events.

Predicting Tunnel Groundwater Inflow by Geological Investigation Using Horizontal Directional Drilling Technology

To improve the prediction accuracy of tunnel excavation groundwater inflow, a prediction method based on a horizontal directional drilling geological survey is proposed. It relies on the monitoring and statistical analysis of groundwater inflow into a horizontal directional drilling survey borehole. Moreover, it is based on Goodman’s empirical back‐calculation for the surrounding rock penetration coefficient and uses the groundwater dynamics method to predict the amount of inflow into the tunnel excavation. On the basis of an analysis of the Tianshan Shengli Tunnel, the following conclusions were obtained: the tunnel excavation groundwater inflow prediction method based on a horizontal directional drilling geological survey borehole can be used to obtain the permeability coefficient value of the surrounding rock, which can be used in the groundwater dynamics method to improve the prediction accuracy; the groundwater runoff modulus method and the atmospheric precipitation infiltration method underestimate the prediction results for tunnel groundwater inflow; and the groundwater dynamics calculation results based on the horizontal survey hole prediction method are more reliable. Goodman’s empirical formula was used to predict normal groundwater inflow within the 2,271 m length from the tunnel entrance: the normal groundwater inflow into the right tunnel was approximately 6,441 m3/d, and the maximum groundwater inflow was approximately 19,323 m3/d. When the tunnel crosses the fault zone, the groundwater inflow increases significantly. The normal groundwater inflow per unit footage is approximately 7.30 m3/(d·m), and the portion of the tunnel that crosses the fault zone is a medium to strong water‐rich section.

B-PO01-024 MECHANICAL AV SYNCHRONY PROVIDED BY A LEADLESS PACEMAKER SUCCESSFULLY TIMES VENTRICULAR ACTIVATION TO THE COMPLETION OF ATRIAL CONTRACTION

Current leadless ventricular pacemakers have the ability to provide AV synchronous (AVS) pacing by tracking late phase right ventricular filling from atrial mechanical contraction. How this accelerometer-based approach translates into appropriate left ventricular filling times is incompletely understood. To characterize left ventricular filling with accelerometer-based AVS pacing among patients with 3rd degree AVB in the MARVEL 2 study. Trans-mitral valve flow was collected on echo during AVS pacing for 6 beats. Each AVS beat was assessed for A-wave truncation. The time from end of A-wave to mitral valve closure was assessed (A-MV) as positive if the A-wave ended prior to MV closure and negative if A-wave truncation occurred. Echo data was available in 37 patients with 3rd degree AVB and AVS > 70%. The mean of each patient’s median peak p-wave to ventricular pace (P-V) time was 153±28 ms (range: 97 - 244 ms). The mean A-wave end to MV closure time was -7.6± 25.2 ms (min. = -46.5 and max. = 58.2), indicating minimal A-wave truncation that was not associated with P-V interval (R2<0.01, P=0.67, Figure). Among patients with a prolonged P-V time (n=6), the mean A-MV time was -9.0± 31.2 ms, suggesting that the accelerometer-based AV pacing may adapt to the patient’s electromechanical delay. Mechanical AV times by the leadless pacemaker are different from TV pacemakers. In patients with normal and prolonged P-V times, the mechanical AV timing algorithm facilitated normal mitral valve inflow patterns that might not be expected from empirically timed AV delays in traditional transvenous pacemakers.

Lake Inflow Simulation Using the Coupled Water Balance Method and Xin’anjiang Model in an Ungauged Stream of Chaohu Lake Basin, China

Water resources are crucial for maintaining daily life and a healthy ecological environment. In order to gain a harmonious development among water resources and economic development in Lake Watershed, it is urgent to quantify the lake inflow. However, the calculation of inflow simulations is severely limited by the lack of information regarding river runoff. This paper attempts calculated inflow in an ungauged stream through use of the coupling water balance method and the Xin’anjiang model, applying it to calculate the inflow in the Chaohu Lake Basin, China. Results show that the coupled model has been proved to be robust in determining inflow in an ungauged stream. The error of daily inflow calculated by the water balance method is between 1.4 and −19.5%, which is within the standard error range (±20%). The calibration and verification results of the coupled model suggest that the simulation results are best in the high inflow year (2016), followed by the normal inflow year (2007) and the low inflow year (1978). The Nash-Sutcliffe efficiencies for high inflow year, normal inflow year, and low inflow year are 0.82, 0.72, and 0.63, respectively, all of which have reached a satisfactory level. Further, the annual lake inflow simulation in the normal inflow year is 19.4 × 108 m3, while the annual average land surface runoff of the study area is 18.9 × 108 m3, and the relative error is −2.6% by the two ways. These results of the coupled model offer a new way to calculate the inflow in lake/reservoir basins.

Characterization of Vortex Flow in a Mouse Model of Ventricular Dyssynchrony by Plane-Wave Ultrasound Using Hexplex Processing.

The rodent heart is frequently used to study human cardiovascular disease (CVD). Although advanced cardiovascular ultrasound imaging methods are available for human clinical practice, application of these techniques to small animals remains limited due to the temporal and spatial-resolution demands. Here, an ultrasound vector-flow workflow is demonstrated that enables visualization and quantification of the complex hemodynamics within the mouse heart. Wild type (WT) and fibroblast growth factor homologous factor 2 (FHF2)-deficient mice (Fhf2 KO/Y ), which present with hyperthermia-induced ECG abnormalities highly reminiscent of Brugada syndrome, were used as a mouse model of human CVD. An 18-MHz linear array was used to acquire high-speed (30 kHz), plane-wave data of the left ventricle (LV) while increasing core body temperature up to 41.5 °C. Hexplex (i.e., six output) processing of the raw data sets produced the output of vector-flow estimates (magnitude and phase); B-mode and color-Doppler images; Doppler spectrograms; and local time histories of vorticity and pericardium motion. Fhf2 WT/Y mice had repeatable beat-to-beat cardiac function, including vortex formation during diastole, at all temperatures. In contrast, Fhf2 KO/Y mice displayed dyssynchronous contractile motion that disrupted normal inflow vortex formation and impaired LV filling as temperature rose. The hexplex processing approach demonstrates the ability to visualize and quantify the interplay between hemodynamic and mechanical function in a mouse model of human CVD.

The role of hydrological processes in ecosystem conservation: Comprehensive water management for a wetland in an arid climate

AbstractWater agreements between Mexico and the United States have been crucial to preserving and restoring the Colorado River Delta's wetlands. Nowadays, increased water demand and climate change in the Colorado River Basin could threaten the conservation of the Ciénega de Santa Clara, a 4709 ha coastal wetland at the Sonoran Desert's edge. The international Ramsar convention recognizes the Ciénega de Santa Clara ecosystem for providing vital ecological services, including habitat for endemic, endangered, and migratory species. The hydrology of this wetland has not been completely understood since the 2010–2011 trial run of the Yuma Desalting Plant. Therefore, this study was conducted to identify and quantify the hydrological elements essential for the conservation of this wetland, under three scenarios: (a) normal inflow conditions of the water source – the Wellton‐Mohawk canal; (b) inflow reductions, and; (c) an increase of temperature due to global warming. Water and mass balances estimates were conducted every month during 2014–2015; in situ measurements of inflows were carried out on Southern International Boundary in Wellton‐Mohawk canal, the Riíto Drain, groundwater, and precipitation: evapotranspiration outputs were estimated using local weather stations and Penman‐Monteith formulations. Temperature increases were based on the Intergovernmental Panel on Climate Change projections for the next 100 years. Results showed disconnection in the surface flow of water from the wetland to the adjacent Gulf of California. This behaviour was observed mainly in the summer months in the three scenarios. The disconnections reduced the wetland area and water storage. The hydrological functionality of the Ciénega de Santa Clara wetland depends on the water supply from the Wellton‐Mohawk canal, with a minimum continuous discharge of 5.10 m3 s−1 during the summer months.

Using a hydrological model to determine the cause of the water supply crisis for the town of Pernik in Bulgaria

In 2019 the Studena reservoir, the only water supply source for the town of Pernik in Bulgaria, accumulated less than half of its normal annual inflow. This factor, together with an inadequate and delayed response by the water resource managers caused a severe water supply crisis in the fall and winter of that year. As this situation was unprecedented, investigations were undertaken to determine the cause of the low inflow to the reservoir using the model CLM3 and available climatic and spatial data, and data that were collected in the watershed for the reservoir. The study was conducted by simulating the hydrological processes that take place in the watershed, and the monthly inflows to the reservoir for the period 2017–2019. It was found that hydrological parameters produced in the calibrated model were similar to those measured in the field and by another model. The achieved agreement was considered to be satisfactory given the complexity of their nature and assessment methods. The result of the study convincingly confirmed that the main reason for the poor inflow to the reservoir in 2019 was the low precipitation in this year and, above all, the scarce snowfall in the winter months. Although the total annual precipitation falling in the region during the period 2017–2019 has not changed significantly, but the seasonal distribution of precipitation has changed. In particular, the amount of precipitation that falls in snowfalls has declined and reached a minimum in 2019. These decreases are due to the increase in the average air temperature of 1 °C which causes the observed decreases in the runoff.

Unilateral biportal endoscopic decompression for degenerative lumbar canal stenosis.

Unilateral biportal endoscopic (UBE) decompression is a minimally invasive (MI) approach to treat degenerative lumbar canal stenosis (DLCS). Decompression can be performed in a clear and magnified surgical field with proper control of normal saline inflow and outflow. Clinical and radiographic data of 81 consecutive patients of DLCS treated between July 2018 and Feb 2019 using UBE techniques were reviewed. They were 38 males and 43 females with an average age of 70.2. Sixty-nine had pure canal stenosis and 12 patients had associated spondylolisthesis. Bilateral decompression via unilateral laminotomy was performed from the side on patients with more severe neurological symptoms. This is a retrospective study from chart review and image analysis. Therefore, we don't have formal ethical information for this study, and it is not mandatory in our hospital. At the final follow-up, the mean VAS for low back pain was improved from 4.3±3.0 to 1.2±1.0 and the VAS for leg symptoms was improved from 7.3±2.2 to 0.9±0.7. The mean JOA score and ODI was significantly improved from 13.3±7.9 to 25.3±5.0 and from 54.6±16.9 to 14.6±12.6, respectively. Modified Macnab criteria were excellent in 47 patients (58.0%), good in 29 (35.8%), fair in 5 (6.2%). The average hospital stay was 3.6±2.4 days. MRI before and after the operation showed the cross-sectional dural area (CSDA) was significantly increased from 71.4±36.5 to 177.3±59.2 mm2, corresponding to a 201.9%±188.0% increase. The percentage of facet joint preservation was 84.2% on the approach side and 92.9% on the contralateral side. Complications included 4 dural tears, 1 transient motor weakness, 1 inadequate decompression, and 1 epidural hematoma. With UBE techniques, decompression for DLCS can be performed safely and effectively. The soft tissue and facet joint destruction are minimized; therefore, it is possible to avoid spinal fusion as well as to preserve the segmental stability.

Financial connectivity and excessive liquidity: Benefit or risk?

This paper explores the structure of cross-border lending market by using network analysis and examines the relationship between financial connectivity and probability of systemic crises during normal, credit boom and capital inflow upsurge periods, controlling for macroeconomic variables. A country-level panel data set for bank-to-bank and bank-to-non-bank cross-border lending markets of 13 advanced economies is used in the analysis for the 1978–2016 period. We find that a rise in financial connectivity reduces the probability of systemic crises. However, this effect is found to be mitigated or completely eliminated in credit boom and capital inflow upsurge periods in both markets. The findings suggest that bank-to-non-bank lending market is more stable in terms of both the number and the amount of lending relationships and recovered faster than bank-to-bank lending market following the recent global financial crisis.

Study on Technology of Surface Pre-grouting for Vertical Shaft in Broken and Water-rich Granite Strata of Gaoligong Mountain Tunnel of Dali-Ruili Railway

The Gaoligong Mountain Tunnel of Dali-Ruili Railway is located between the Nujiang River and the Longling County Town in the southeastern section of the Hengduan Mountains, China. In geological history, this area was affected by multiple tectonic movements, and the faulted structures are extremely developed. During the drilling inspection hole of No.2 vertical shaft, boring tool stuck and the hole collapse once happened. Its depth was 643.12 m, the outcropped strata were all granite or weathered granite (fracture zones). 7 fracture zones with thickness > 10 m were uncovered, the maximum thickness of which was 112.95 m; and 7 water bearing strata were uncovered, of which the buried depth of groundwater table was all less than 34m, the permeability coefficients(k) were 0.005∼0.158 m/d. It was estimated that the water inflow of ④ ∼ ⑦ aquifers of the main shaft and the auxiliary shaft of No. 2 shaft were all greater than 120 m3/d (5 m3/h), that normal water inflow of main shaft and auxiliary shaft of No.2 vertical shaft would be 125.92 m3/h and 90.08 m3/h respectively. In order to avoid water inrush and wall caving accidents during the construction of the two shafts, it was decided to adopt the surface pre-grouting method in the construction of the shafts to block off and reinforce the ④ aquifer and the strata under the aquifer. The “S” shaped directional drilling technology was used; the two sequences, segmented downward, multiple-times grouting mode was adopted; clay-cement slurry was selected as the grouting material. After grouting, pump yield water tests were carried out in two grouting holes of main shaft and auxiliary shaft. The remaining water inflow in grouting sections of two shafts was 5.02 m3/h and 5.70 m3/h respectively, and the rates of water blocking were all over 93%. The grouting effect was remarkable. The successful implementation of the surface pre-grouting project of No.2 vertical shaft in Gaoligong Mountain Tunnel of Dali-Ruili Railway has important guiding significance for the design and construction of tunnel and mine shafts in broken water-rich granite stratum.

Outcomes of endovascular reconstruction of the inferior vena cava with self-expanding nitinol stents.

Occlusion of the inferior vena cava (IVC) often causes venous claudication, leg swelling, or skin changes. We hypothesized that the outcome of nitinol stents for endovascular reconstruction of the IVC is similar to the outcome reported for steel alloy stents. From the prospective Bern Venous Stent Registry, we investigated technical success, patency rates, and clinical outcome in consecutive patients with endovascular IVC reconstruction. During routine follow-up visits, stent patency was assessed by duplex ultrasound. Clinical outcomes were evaluated using the Bozkaya score, Villalta score, and revised Venous Clinical Severity Score. Of the 62 patients (mean age, 46± 18years), 33 (53%) patients were treated for the post-thrombotic syndrome, 17(27%) for acute thrombosis, and 12 (19%) for nonthrombotic IVC occlusion. Technical success was achieved in 61 (98%) patients, with a mean of 4.5± 1.9 stents (iliac kissing stents in 84%). During follow-up (mean, 21months), 22 (36%) underwent endovascular reintervention for symptomatic stent stenosis (13 [21%] with complete stent occlusion). Primary, primary assisted, and secondary patency rates at 24months were 57% (95% confidence interval [CI], 50%-73%), 76% (95% CI, 65%-86%), and 87% (95% CI, 80%-95%), respectively. None developed new ulcers, and all eight patients with venous ulcers at baseline had complete healing. Twenty-nine (48%) patients showed significant clinical improvement, and another 26 (43%) were free from any symptoms or signs of venous hypertension. Patients with post-thrombotic venographic changes of the femoral veins at baseline or a history of thrombosis were more likely to lose primary patency compared with patients with normal leg inflow veins and no history of thrombosis (19 [48%] vs 3 [16%]; P= .02). The clinical outcome of endovascular reconstruction of the IVC with nitinol stents was favorable. However, approximately one-third of the patients required reintervention to maintain stent patency, most likely because of the impaired venous inflow.

Groundwater Source Discrimination and Proportion Determination of Mine Inflow Using Ion Analyses: A Case Study from the Longmen Coal Mine, Henan Province, China

Complex hydrogeological conditions in China’s coal mines have contributed to frequent mine water disasters. A simple and effective method to determine water inflow sources and paths is therefore essential. The Longmen Mine, located in Henan Province, in central China was used as a case study. A Piper diagram and cluster analysis were used to screen the characteristic values of 18 water samples from potential aquifers. A comprehensive fuzzy evaluation of the groundwater ions was carried out to determine the main source of the total mine inflow. Then, based on conservation of ionic masses, a matrix function was established to calculate the groundwater recharge composition. Finally, using measured water inflows for the Cambrian limestone aquifer, the calculated and observed results were compared. The results showed that the Carboniferous Taiyuan Formation limestone aquifer (the L7 limestone aquifer) accounts for 60.8% of the total mine inflow, while the Cambrian limestone and roof sandstone aquifers account for 34.8 and 4.4% of the inflow, respectively. The normal mine inflow totals about 19,200 m3/day, of which 6,840 m3/day is from the Cambrian limestone aquifer. This agrees well with the calculated value of 6,720 m3/day. Thus, the method is feasible and reliable.

Emergency Kidney Transplantation in Recipients With Iliocaval Thrombosis Using Splenic Vessel Anastomosis After Splenectomy: A Case Series

BackgroundThe external iliac vein is the standard site used for venous anastomosis in kidney transplantation. When a pre-transplantation diagnosis of iliocaval thrombosis is established, a different and suitable venous drainage for the renal outflow must be identified for successful transplant. MethodsWe report 4 cases of kidney transplantation, performed from 2004 to 2016, in recipients presenting with thrombosis of the inferior vena cava and iliac system needing, because of the lack of access for dialysis, urgent kidney transplantations. The splenic vessels were used in all cases for the graft’s vascular anastomosis after splenectomy. ResultsKidney transplantation after splenectomy, with anastomosis of the renal vessels to the splenic ones, was completed in all 4 patients. All of the cases were technically successful with good renal function on discharge. During the follow-up, no graft losses were registered as due to thrombotic event or inadequate renal venous outflow. A normal vascular inflow and outflow was confirmed by means of follow-up ultrasound. Two grafts were lost at 31 months and 91 months, both to noncompliance with immunosuppressive therapy. The other 2 are currently functioning well. Notably, the kidney’s position in the left upper quadrant has not caused technical difficulties in urologic reconstruction. ConclusionsIn our experience, kidney transplantation using splenic vessels for vascular anastomosis is technically feasible and very useful in the setting of complete iliocaval thrombosis.

Providing a Reliable Water Level Control in Main Canals under Significant Inflow Fluctuations at Drought Periods within Canal Automation

Supplying agricultural water has recently become more challenging due to increase in drought frequency in semi-arid regions. Unreliable supply water resources lead to inflow fluctuations in irrigation districts locating at the downstream part of the rivers. The conventional operation cannot handle the fluctuations effectively; therefore, water delivery to the off-takes is seriously compromised. In this study, the capability of decentralized Proportional-Integral (PI) and centralized Linear Quadratic Regulators (LQR) controllers were investigated to alleviate the effects of severe inflow fluctuations in the main irrigation canals operation. In this regard, the Roodasht North Branch (RNB) main canal, located in the central Iran, consisting of 24 reaches was selected as a test case. Mathematical operational model of the canal was coupled with the designed PI and LQR controllers. The performance of the controllers were evaluated under the normal and severe unpredictable inflow fluctuations scenarios. The results showed that the PI configuration was able to successfully deal with and handle the normal inflow fluctuations. Water delivery to the upstream and middle canal reaches was regulated reasonably well, while the downstream canal reaches were still slightly suffering from the inflow fluctuation. The LQR controller showed an outstanding performance in dealing with both normal and severe inflow fluctuation test scenarios. The controller optimally adjusted the gates accordingly to manage even the sever inflow fluctuation. The results of this study demonstrate capabilities of the control configurations in managing the inflow fluctuations in main canals which can help moving towards the urgent needs for improving the current canal operational performance.

Flexible use of electricity in heat-only district heating plants

European energy systems are in a period of significant transition, with the increasing shares of variable renewable energy (VRE) and less flexible fossil-based generation units as predominant factors. The supply-side changes are expected to cause large short-term electricity price volatility. More frequent periods of low electricity prices may mean that electric use in flexible heating systems will become more profitable, and such flexible heating systems may, in turn, improve the integration of increasing shares of VRE. The objective of this study is to analyze the likely future of Nordic electricity price levels and variations and how the expected prices might affect the use of electricity and thermal storage in heat-only district heating plants. We apply the North European energy market model Balmorel to provide scenarios for future hourly electricity prices in years with normal, high, and low inflow levels to the hydro power system. The simulation tool energyPRO is subsequently applied to quantify how these electricity price scenarios affect the hourly use of thermal storage and individual boilers in heat-only district heating plants located in Norway. The two studied example plants use wood chips or heat pump as base load representing common technologies for district heating in Norway. The Balmorel results show that annual differences in inflow is still a decisive factor for Norwegian and Nordic electricity prices in year 2030 and that short-term (daily) price variability is expected to increase. In the plant-level simulations, we find that tank storage, which is currently installed in only a few district heating plants in Norway, is a profitable flexibility option that will significantly reduce the use of fossil peak load in both biomass and heat-pump-based systems. Installation of an electric boiler in addition to tank storage is profitable in the heat pump system due to the limited capacity of the heat pump. Electricity will hence, to a large extent, replace gas when heat demand exceeds the capacity of the heat pump. For the bio-based plant, we find that an electric boiler in addition to tank storage is not profitable in the normal electricity price scenario. The electric boiler investments are only profitable when electricity prices are as low as in the high inflow scenario. In that case the electric boiler will provide 17% of the heat supply in the example plant. Fuel prices for peak load and electricity grid tariffs are found to be decisive factors for the electricity use – and therefore flexibility options – provided by heat-only district heating plants.