Search Results (44)

Drip irrigation system performance is largely governed by emitter hydraulic characteristics. This study systematically compares the hydraulic performance of a novel cylindrical asteroid-shaped channel emitter against a conventional toothed labyrinth design. Standardized specimens were produced using precision molds and integrated into drip tapes at 300 mm spacing. To comprehensively analyze flow behavior, pressure–discharge relationships, flow indices, and internal flow fields, a combination of physical experiments and CFD simulations was employed. Experimental results showed that across 20–200 kPa, the cylindrical asteroid-shaped emitter delivered flow rates 24–28% higher than the labyrinth type while maintaining a lower flow index, demonstrating enhanced hydraulic stability. Flow field analysis at 100 kPa revealed that the divergent asteroid geometry generates more intense and sustained turbulent kinetic energy throughout the channel units, resulting in superior energy dissipation. The cylindrical asteroid-shaped unit achieved a pressure drop of 17.5 kPa, exceeding the 15.3 kPa observed in the labyrinth channel, with outlet velocities of 1.6 m/s versus 1.76 m/s. Additionally, the flow pattern promotes comprehensive wall scouring through large-scale vortices, indicating improved resistance to clogging. These findings validate the design superiority of the cylindrical asteroid-shaped emitter and offer a theoretical reference for developing high-uniformity, water-saving irrigation devices. Full article

Long-term operation of drip emitters under sediment-laden water conditions readily induces particle deposition and clogging, leading to discharge reduction and deterioration of irrigation uniformity. To clarify the temporal evolution and spatial distribution of clogging and to support structure-oriented anti-clogging improvement, three integrated drip tape emitters with different labyrinth-channel geometries were tested at sediment concentrations of 1, 2, and 3 g·L⁻¹ under a constant pressure of 100 kPa. The average relative discharge ratio (Dra) and Christiansen’s uniformity coefficient (CU) were continuously monitored, and cross-sectional observation and numerical simulation were combined to identify dominant deposition hotspot regions within the labyrinth channel. The results showed that increasing sediment concentration significantly accelerated clogging development and shortened operating lifetime. At 1 g·L⁻¹, the times required for the three emitter types to reach the clogging criterion of Dra < 75% were 120, 81, and 107 h, respectively, whereas at 3 g·L⁻¹ these values decreased to 39, 42, and 39 h. CU continuously declined with operating time and, in some treatments, responded earlier than Dra to system deterioration. Sediment deposition was mainly concentrated in the inlet section and bend regions, indicating that these locations were the dominant hotspots for clogging initiation and propagation. These findings demonstrate that clogging in drip emitters is jointly regulated by sediment load and labyrinth-channel geometry, and that hotspot-based structural optimization provides an effective basis for improving anti-clogging performance under sediment-laden water conditions. Full article

Congenital umbilicobiliary fistula is a rare disease reported in humans and dogs. A 2-month-old, intact, male French Bulldog presented with a greenish-yellow discharge dripping from the umbilicus since birth. Complete blood count and serum biochemistry were within normal limits, but serum alkaline phosphatase activity was mildly elevated. A positive contrast cystogram was performed to rule out a patent urachus and confirmed the presence of a vesicourachal diverticula, a type of urachal anomalies. An abdominal ultrasound and computed tomography fistulogram demonstrated a communication between the umbilicus and common bile duct, which suggested an umbilicobiliary fistula. Surgical correction of the umbilicobiliary fistula and vesicourachal diverticula was successfully performed with an uneventful recovery. Histological analysis of the fistulous tract demonstrated a cuboidal/columnar lining epithelium that transitioned to squamous epithelium near the umbilicus. Agenesis of the gallbladder was noted. The application of multiple imaging techniques in the diagnosis and surgical correction of these congenital abnormalities (umbilicobiliary fistula, gallbladder agenesis, and vesicourachal diverticula) was beneficial for treatment planning and outcome. Full article

Agriculture faces growing pressure to optimize water use, particularly in woody perennial crops where irrigation systems are installed once and seldom redesigned despite changes in canopy structure, soil conditions, or plant mortality. Such static layouts may accumulate inefficiencies over time. This study introduces a decision support system (DSS) that evaluates the hydraulic adequacy of existing irrigation systems using two new concepts: the Resource Overutilization Ratio (ROR) and the Irrigation Ecolabel. The ROR quantifies the deviation between the actual discharge of an installed irrigation network and the theoretical discharge required from crop water needs and user-defined scheduling assumptions, while the ecolabel translates this value into an intuitive A+++–D scale inspired by EU energy labels. Crop water demand was estimated using the FAO-56 Penman–Monteith method and adjusted using canopy cover derived from UAV-based canopy height models. A vineyard case study in Galicia (Spain) serves an example to illustrate the potential of the DSS. Firstly, using a fixed canopy cover, the FAO-based workflow indicated moderate oversizing, whereas secondly, UAV-derived canopy measurements revealed substantially higher oversizing, highlighting the limitations of non-spatial or user-estimated canopy inputs. This contrast (A+ vs. D rating) illustrates the diagnostic value of integrating high-resolution geospatial information when canopy variability is present. The DSS, released as open-source software, provides a transparent and reproducible framework to help farmers, irrigation managers, and policymakers assess whether existing drip systems are hydraulically oversized and to benchmark system performance across fields or management scenarios. Rather than serving as an irrigation scheduler, the DSS functions as a standardized diagnostic tool for identifying oversizing and supporting more efficient use of water, energy, and materials in perennial cropping systems. Full article

Background: Acute aortic occlusion (AAO) is a rare but life-threatening condition which can present with a spectrum of symptoms, ranging from mild cramping pain in the lower extremities (with or without sensory loss) to more dramatic motor loss and paraplegia. Once a diagnosis has been established, the treatment remains ambiguous, especially in a resource-limited setting. Treatment ranges from direct vascular intervention to systemic or directed thrombolysis—however, there is a lack of published literature on systemic thrombolysis, and thereby, consensus guidelines are nonexistent. Additionally, systemic thrombolysis bears a risk of hemorrhagic complications; however, the risk of death due to AAO is up to 57 times greater than the risk of intracerebral hemorrhage from systemic thrombolysis. Methods: This case report explores the prompt diagnosis of an acute aortic occlusion causing bilateral acute lower extremity ischemia in a sixty-three-year-old female patient treated with systemic thrombolysis. Results: The patient received 100 mg of tPA (without a bolus dose, over a two-hour period) in the Emergency Department (similar to that which is administered for the full-dose pulmonary embolism protocol). One hour after administration, the patient had restored flow to the bilateral lower extremities verified using bedside color-flow Doppler, with a drastic improvement in her symptoms. Two days after systemic thrombolysis, a repeat CTA showed evidence of complete resolution of her aortic clot. Her condition was complicated by a brief episode of retroperitoneal bleeding (presenting with flank pain) while on a heparin drip after admission (day two), which was resolved through discontinuation of the heparin drip and a two-unit blood transfusion. Conclusion: The patient was discharged with full function of the lower extremities on day six without anticoagulation. At her 2-week follow-up appointment, she was noted to be ambulatory without any neurodeficit, with a persistently restored arterial flow to the lower extremity. The application of systemic tPA could be paramount in the treatment of AAO in the setting of ischemic limb pathology, particularly at rural hospitals and healthcare centers where urgent direct vascular intervention may not be possible. Full article

To optimize water–nitrogen management for mulched drip-irrigated peanuts in Xinjiang, a three-season field experiment was conducted to assess the impacts of drip irrigation rates and water–nitrogen coupling on peanut growth, yield, quality, and water–nitrogen use efficiency. Two irrigation accounts (30 and 37.5 mm, denoted as W1 and W2), three nitrogen application levels (half nitrogen application and conventional nitrogen application, denoted as N1 and N2), and a control treatment (CK) without nitrogen application, and two drip discharge rates (3.0 and 6.0 L h⁻¹, denoted as Q1 and Q2) were utilized for a total of five treatments per year, and the experiment was repeated three times. The results demonstrated that the irrigation and fertilization parameters of the W2N1Q2 treatment could significantly improve peanut growth, yield, quality, and water–nitrogen use efficiency, achieving optimal values for all measured indicators. Compared with the control (W2N0Q1), the main stem height increased by 9.59% and 13.13%, the aboveground biomass increased by 6.32% and 34.67%, the yield increased by 26.69% and 20.97% (p < 0.01), the water use efficiency increased by 27.08% and 16.33%, the nitrogen partial factor productivity values were 47.39 and 77.00 kg kg⁻¹, the protein content increased by 3.99% and 4.63%, and the oil content increased by 1.68% and 8.53%, respectively. A PCA was performed using five key performance indicators (yield, protein content, oil content, water use efficiency, and nitrogen partial factor productivity) to evaluate different treatment combinations. The W2N1Q2 treatment obtained the highest composite score, indicating its overall superior performance among all treatments. Therefore, under the conditions of this experiment, the irrigation and nitrogen application parameters for achieving both a high yield and quality of peanuts under mulched drip irrigation in Xinjiang were determined to be W2N1Q2 treatment (irrigation account of 37.5 mm, nitrogen application of 118 kg ha⁻¹, and drip discharge of 6.0 L h⁻¹). This optimized combination brings three key advantages to water-scarce regions: (1) maximizing yield water use efficiency through precise irrigation scheduling; (2) balanced nutrient management to prevent nitrogen wastage; and (3) providing a key technological reference for agricultural production in Xinjiang and other similar ecological zones. Full article

Against the backdrop of the steady advancement of the national rural revitalization strategy and the dual-carbon goals, the low-carbon transformation of rural energy systems is of critical importance. This study first proposes a comprehensive architecture for rural energy supply systems, incorporating four key dimensions: investment, system configuration, user demand, and policy support. Leveraging the abundant wind, solar, and biomass resources available in rural areas, a low-carbon optimization model for rural energy system operation is developed. The model accounts for diverse load characteristics and the integration of elevated water towers, which serve both energy storage and agricultural functions. The optimization framework targets the multi-energy demands of rural production and daily life—including electricity, heating, cooling, and gas—and incorporates the stochastic nature of wind and solar generation. To address renewable energy uncertainty, the Fisher optimal segmentation method is employed to extract representative scenarios. A representative rural region in China is used as the case study, and the system’s performance is evaluated across multiple scenarios using the Gurobi solver. The objective functions include maximizing clean energy benefits and minimizing carbon emissions. Within the system, flexible resources participate in demand response based on their specific response characteristics, thereby enhancing the overall decarbonization level. The energy storage aggregator improves renewable energy utilization and gains economic returns by charging and discharging surplus wind and solar power. The elevated water tower contributes to renewable energy absorption by storing and releasing water, while also supporting irrigation via a drip system. The simulation results demonstrate that the proposed clean energy system and its associated operational strategy significantly enhance the low-carbon performance of rural energy consumption while improving the economic efficiency of the energy system. Full article

High-voltage transmission and substation projects at high altitudes are pivotal in realizing the objective of universal electricity access. However, the reduced air density at elevated heights facilitates the formation and propagation of discharges, posing more stringent challenges to the external insulation of these projects compared to their counterparts in plains areas. Furthermore, considering the influence of meteorological conditions such as rainfall, it is imperative to conduct comprehensive experimental studies on the insulation properties of air gaps to inform the design and maintenance of engineered external insulation. This paper presents the results of rod–plane gap discharge tests conducted under dripping conditions at an actual high-altitude location of 2500 m. The employed test methodology effectively simulates the impact of rainfall on the insulation characteristics of the gap. Based on the experimental findings, a detailed analysis is conducted on the effects of gap distance, dripping flow rate, and conductivity on the gap breakdown voltage. Additionally, the discharge paths and underlying mechanisms under water-dripping conditions on rod electrodes are briefly discussed. The acquired data and conclusions contribute to a deeper understanding of the mechanisms governing rainfall effects on gap discharges and provide valuable insights for the design of external insulation in high-altitude HVDC transmission projects. Full article

This study focused on evaluating the performance of the drip irrigation systems installed in 18 different nectarines (Prunus persica var. nucipersica) orchards in the Tarsus Plain in the Mediterranean region from 2017 through 2018. The performance of the drip systems was evaluated based on parameters like average emitter discharge (Qavg), Christiansen uniformity coefficient (CU), distribution uniformity (DU), emission uniformity (EU), and system application efficiency (Ea). The results indicated that the CU varied between 81 and 98%; DU changed from 82 to 97%; EU 61–92%; absolute emission uniformity (EUa) ranged between 93 and 98%; statistical uniformity (Us) changed from 85 to 97%; application efficiency of low-quarter (AELQ) varied between 45 and 97%; potential application efficiency of low-quarter (PELQ) ranged between 55 and 83%; system application efficiency (Ea) changed from 56 to 96%; storage efficiency (Es) fluctuated between 45 and 97%; and pressure variation (Pv) 17–81% and emitter flow variations (qv) of 2–36% were determined. Although the CU, DU, and EU values were acceptable, the variations in emitter flow rates and pressures were not acceptable. The results revealed that the lower performances might be attributed to physical clogging and/or lack of system design and application practices by the farmers. It is recommended that the farmers receive appropriate training on the operation and management of drip irrigation systems. Full article

An accurate estimation of a soil wetting front is important for improving water-use efficiency under drip irrigation. This study is aimed at determining the wetting front of sandy soil under drip irrigation using the existing and modified empirical equations and optimizing the input parameters using the response surface methodology (RSM). This study was conducted during the dry season in sandy soil containing a hard pan at a soil depth of about 30 cm. The soil wetting front was measured using measuring tape at two emitter discharges under a point-source drip irrigation system type. An evaluation of the models for the wetting fronts during calibration and validation showed that the coefficient determination (r²) ranged between 77–98% and 79–99% for the empirical and modified models, respectively. The normalized root mean square error (NRMSE) was less than 20% and greater than 20% for the modified and existing equations, respectively, thus emphasizing that the modified model produced a better result. Using the RSM approach, the linear + interaction produced the best result, and the optimization result revealed an optimum irrigation time and volume of 75 min and 225 cm³, corresponding to a maximum wetting depth and width of 26.8 and 21.7 cm, respectively. Full article

Drip irrigation with a fertilizer application could effectively alleviate the soil pollution caused by excessive phosphorus fertilizer. Phosphate fertilizer was dissolved in water and produced a chemical reaction with the ions in irrigation water. The new precipitates were generated, which caused more severe and complex blockage of drip irrigation emitters. Songhua River water was selected as the irrigation water. The experiment investigated the effects of three types of phosphorus fertilizers (urea phosphate, UP; potassium dihydrogen phosphate, PDP; ammonium polyphosphate, APP) and the concentrations (0.2, 0.3, and 0.4 g/L) on the blockage of drip irrigation emitter. The results showed that three types of phosphorus fertilizers intensified the degree of blockage compared with no fertilization, the order from small to large being UP < PDP < APP. The degree of blockage was directly proportional to the concentration of phosphate fertilizer. The system discharge variation ratio (Dra) under UP, PDP, and APP treatments decreased by an average of 6.2~27.7%, 13.8~33.8%, and 21.5~44.6%, respectively. The Christiansen coefficient of uniformity (CU) decreased by an average of 5.9~23.5%, 10.3~27.9%, and 19.1~38.2%. The UP was superior to PDP and APP from the perspective of drip irrigation evaluation indicators. The main reason was that UP reduced the pH value of the water source and inhibited the generation of carbonates. The APP was unable to lower the pH value and had the most serious blockage. The APP was coupled with three concentrations of Mn²⁺ (1, 2, and 3 mg/L) for drip irrigation, which could optimize the blockage problem and explore the efficacy of Mn²⁺. The 2 mg/L Mn²⁺ could maximize the drip irrigation efficiency of the APP. The average increase in Dra and CU was 24.57% and 18.54% macroscopically. Mn²⁺ could alter the lattice parameters of carbonates and had a certain impact on their size and morphological distribution on a microscopic level. The results showed that fertilization with UP at a concentration of 0.2 g/L did not significantly exacerbate clogging. The drip irrigation effect of Songhua River water combined with 0.2 g/L concentration UP was the best. Moreover, 2 mg/L of Mn²⁺ was proposed to alleviate the clogging characteristics of APP4. This study could provide reference for improving the efficiency of the Songhua River drip irrigation system. Full article

Accurate numerical simulation of turbulent flow within the milli-channels of drip irrigation emitters has long been a significant challenge. This paper presents a comprehensive Reynolds-Averaged Navier–Stokes (RANS) modeling-based analysis of the flow dynamics within the labyrinth milli-channel of a tooth-shaped emitter, with partial experimental validation. The objective was to assess the performances of four RANS turbulence models: RNG k-ε (RNG), Realizable k-ε (RKE), SST k-ω (SST), and baseline k-ω (BSL), alongside three near-wall treatments: scalable wall function (SWF), enhanced wall treatment (EWT), and y⁺-insensitive wall treatment (YIWT) for emitter flow analysis. The results showed that the RNG and RKE, coupled with EWT, are preferred options for predicting the flow rate—pressure loss relationship of the emitter, with relative errors of 2.08% and 1.02% in the discharge exponent and 5.66% and 7.58% in the flow rate coefficient, respectively. Although both RNG and RKE using SWF are viable for hydraulic performance prediction under high-flow rate conditions, the deviation of predicted flow rate reaches up to 25.46% under low-flow rate conditions. The SST and BSL models, which employ IYPT, captured induced vortices at channel corners; however, they underestimated emitter flow rates. Furthermore, computations using SWF failed to capture the asymptotic characteristics of flow parameters in the near-wall region, resulting in an overestimation of turbulent kinetic energy and turbulence intensity. Additionally, the magnitude of wall shear stress in the channel corners fell below the threshold required for self-cleaning, underscoring the necessity for optimizing channel structures to enhance the anti-clogging performance of the emitter. Full article

Introduction: Tight glycemic control is essential for optimal outcomes after coronary artery bypass graft (CABG) surgery, regardless of pre-operative diabetes status. The ideal timing for transitioning from intravenous (IV) to subcutaneous (SC) insulin remains unclear. This study addresses this knowledge gap by comparing the effects of early transition (postoperative day 1, POD1) versus delayed transition on glycemic control and patient outcomes after CABG surgery. Methods: We analyzed data from a single tertiary medical center focusing on patients receiving insulin during their CABG hospitalization between 1 and 31 October 2022. We divided patients into two groups based on their transition timing: (1) Delayed Transition Group, patients transitioned from IV insulin infusion to SC insulin after POD1; and (2) Early Transition Group, patients transitioned on POD1. The primary outcome was the incidence of euglycemia on POD1. Secondary outcomes included rates of maintaining euglycemia from POD1 until POD10 or hospital discharge, hospital length of stay (LOS), ICU LOS, mean glucose levels, rates of hyperglycemia (blood glucose > 180 mg/dL) and hypoglycemia (blood glucose < 70 mg/dL), and rate of restarting IV insulin. Statistical analysis adjusted for BMI and diabetes diagnosis. Results: A total of 394 patients were enrolled, with 68 patients (17.3%) in the delayed-transition group and 326 patients (82.7%) in the early-transition group. Majority of the patients were males (74%), with an average age of 67 ± 9 years. Mean HbA1C and creatinine levels were comparable between the two groups. Patients in the early-transition group experienced a shorter ICU and hospital length of stay compared to the delayed-transition group, without a higher risk of restarting IV insulin. Conclusions: Early transition from IV insulin drip to SC insulin on POD1 of CABG surgery reduces ICU and hospital LOS without increasing the risk of transitioning back to IV insulin. Full article

The hydrochemical characteristics of watersheds are influenced by many factors, with chemical weathering and human activities exerting the most substantial influence. Performing a quantitative evaluation of the factors contributing to the chemical weathering of rocks is of significant scientific importance. This research zeroes in on the Qingtang River basin to elaborate on the hydrochemical characteristic, explore the origins of ions, and quantify the influence of anthropogenic discharges amidst cation interferences, thus improving the accuracy of chemical weathering rate estimations. The samples encompassed surface water, groundwater, and water from dripping in karst caves. The findings indicate that human-induced alterations significantly influence hydrogeochemical dynamics, although chemical weathering of rocks in their natural state is the controlling factor. The mean contributions of cations from atmospheric deposition, human inputs, carbonate weathering, and silicate weathering were 17.56%, 21.05%, 51.77%, and 9.54%, respectively. The chemical weathering rate for carbonate rocks was 62.4 t·km⁻²·a⁻¹, which increased by 27.87% due to the influence of exogenous acids. The anthropogenic impact is predominantly evident in two aspects: (1) the alteration of hydrochemical processes within the watershed through direct input of ions, and (2) the acceleration of rock weathering rates in the watershed due to the exogenous acids. Full article

Salt accumulation in bare strips under film-mulched drip irrigation is a global concern as it adversely affects soil quality and hinders sustainable agricultural development in arid and semi-arid regions. This study aims to investigate the spatial distribution of soil moisture and salt under various planting patterns and assess the lateral salt accumulation effect in bare strips. Seven treatments were implemented based on the local cotton planting pattern, including the local classical planting pattern (LTP), mulch width of 220 cm (WFM-220), spacing of 90 cm (SFM-90), mulch width of 40 cm (WFM-40), spacing of 10 cm (SFM-10), ridge tillage (TFM-RT), and ditching (TFM-D), varying in mulch width, spacing, and tillage method in bare strips. Additionally, the performance of the HYDRUS-2D model was evaluated by comparing simulated and observed values using field data. The results revealed that (I) the WFM-220 cm treatment exhibited the best water content retention under mulched film, with lower salt accumulation in the surface bare strip (0–20 cm soil layer); (II) all treatments with narrow rows showed desalination effects in the 0–40 cm soil layer, with salt content reductions ranging from approximately 13% to 38% compared to the initial values; (III) under the LTP treatment, the lateral salt discharge effect in the bare strip of the 0–40 cm soil layer was the best, regardless of mulch width and spacing, with a salt accumulation rate up to three times higher than the initial value, and even up to four times higher in the 0–10 cm layer; (IV) the TFM-RT treatment exhibited the best salt accumulation ability on the surface bare strip; and (V) the HYDRUS-2D model proved to be an effective tool for studying the dynamic regulation mechanism of water and salt with root mean square error values ranging from 0.079 to 0.106 cm³·cm⁻³ for soil water content and from 0.044 to 0.079 dS·m⁻¹ for electrical conductivity, indicating good agreement between simulations and observations. Full article