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The efficiency paradox of discharge masking head loss in run-of-river hydropower generation
Abstract While climate impacts on hydropower output are well-documented, plant efficiency, the critical ratio of electrical energy generated to hydraulic energy input, remains an underexplored metric, particularly in data-limited regions. This study analyzes the efficiency dynamics of the Ruzizi I plant (29.8 MW) from 2000 to 2023 to unravel the interplay between hydrological drivers and operational constraints. Building on the established context of a hydraulic trade-off between water volume and head, we employed machine learning (Multiple Linear Regression, Random Forest, Gradient Boosting) and operational analysis to diagnose efficiency drivers. Results reveal that plant efficiency increased significantly (+ 3.6%-points/decade) and is overwhelmingly governed by discharge ( r = 0.998), with machine learning models confirming the negligible role of head and seasonality. This indicates that efficiency gains are almost entirely flow-dependent, masking the potential negative impact of head loss. The system exhibits strong buffering from Lake Kivu, with efficiency remaining stable during drought but surging by 17–18% during wet years. Crucially, operational analysis identified an optimal load factor range (78–82%) that could improve efficiency by ~ 4% points compared to historical operation. However, a concurrent decline in available capacity factor (− 5.5%/decade) signals emerging non-hydrological constraints. These findings underscore that while water volume currently dominates efficiency gains, long-term sustainability requires managing sediment-induced head loss and optimizing operations within the identified optimal range to mitigate the underlying vulnerabilities in the energy conversion process.
AI and nuclear energy feature strongly in agenda-setting technologies for 2026
A prospective study of intravenous iron effectiveness on quality of life and functional outcomes in patients with cancer
Upregulated miR-204-5p inhibits oral squamous cell carcinoma progression via inducing autophagy-promoted apoptosis by targeting PIK3CB
Community participatory Jingchu folk pattern generation platform construction and user co-creation mechanism analysis
Feed intake, digestibility and passage kinetics in grazing horses
Abstract Feed intake and digestibility are important indicators for sufficient nutrient supply, but they can be assessed only to a limited extent in horses on pasture. In horses, feed intake is embedded in a complex behavioural pattern of searching, selecting, chewing and almost constant movement called foraging. The objectives of this study were to estimate organic matter intake (OMI) and organic matter digestibility (OMD) in six horses, 24 h/day on pasture, based on plant alkanes and synthetic n -hexatriacontane (C 36 ) excretion. A multi-compartmental model was fitted to the marker excretion and the C 36 mean retention time (MRT) was estimated. The travelling activity influences the intestinal passage and digestion of the forage. For this reason, the travelled distances were tracked during the daylight hours (i.e., 13 h/day) by the global positioning system (GPS). The C 36 MRT was 17.5 h based on an excretion curve, in which all horses were considered. Fitting individual excretion curves was less successful due to limited data points available for each horse. Depending on the plant marker, an OMI of 1.4 to 2.8% of body weight (BW)/day was estimated, which is analogous to a dry matter intake (DMI) of 1.5 to 3.1% of BW/day. The estimated OMD ranged from 0.45 to 0.68, dry matter digestibility (DMD) analogously from 0.39 to 0.65. The estimates obtained using n -nonacosane (C 29 ), followed by those obtained using n -hentriacontane (C 31 ), seemed to be the most plausible compared to the literature. Using C 29 , a feed intake of 2.5% of BW/day (group) or 2.1% of BW/day (individuals) was estimated on organic matter basis, which was 2.7% of BW/day or 2.3% of BW/day on dry matter basis. An OMD of 0.64 and a DMD of 0.61 was estimated using C 29 . Individually travelled distances ranged from 0.09 to 4.64 km in 1 h with differences detected among the days ( p < 0.01), but not among the hours monitored within a day. Despite clear limitations, the methods seemed to be reliable to assess feed intake on pasture and to track movement activity. In modern husbandry systems, foraging should be as much unrestricted as possible to satisfy natural behavioural needs.
Derivation of an intrinsic brain activity biomarker for the earliest prediction of cognitive decline
Correction: Chitosan and carboxymethyl chitosan nanocarriers enhance mango seed extract stability and antimicrobial activity to improve strawberry postharvest quality
Mechanical performance of sustainable concrete containing industrial waste admixtures of SF, FA, CCI, and crushed quartz at different water–binder ratios
Abstract The present study examined the mechanical performance of sustainable concrete with silica fume (SF), fly ash (FA), cooled cast iron (CCI), and crushed quartz powder (CQ) used as partial cement replacements at three water-to-binder ratios (0.36, 0.41, and 0.46). Fifteen concrete mixtures were cast and tested for compressive, splitting tensile, and flexural strengths at 7, 28, and 90 days. Results indicated that the lowest water–binder ratio of 0.36 produced the highest strengths, consistent with values of 78 MPa compressive strength at 28 days and 87.8 MPa at 90 days, which were better than those obtained from mixes having the other two ratios by up to 34% in early ages and by up to 33% in later ages. The partial replacement of SF by FA lowered the early-age strength, but very significant long-term gains were recorded; replacing three-quarters of SF with FA increased the 90-day compressive strength by 5.9%, 30.4%, and 30.1% for groups 0.36, 0.41, and 0.46, respectively, compared to their corresponding mixes with SF only. Incorporating CQ led to reductions in strength at 28 days of 9.3–13.4%; however, reductions at 90 days remained modest, 8.1–13.6%, indicating improved long-term pozzolanic contributions. It is noted that tensile-to-compressive strength ratios for all mixtures ranged from 9.8 to 12.2%, and flexural-to-compressive ratios ranged from 13.6 to 14.7%, which are better than the ACI318 predictive correlations for concretes using industrial by-products. The results confirm that optimized SCM blending higher fly-ash proportions at lower water–binder ratios enhances long-term mechanical performance while enabling significant cement reduction, supporting more environmentally sustainable high-strength concrete.
Symmetry, microscopy and spectroscopy signatures of altermagnetism
Spatial pattern separation deficits in early Alzheimer’s disease are comparable in humans and animal models
Abstract Spatial pattern separation (SPS) is a memory process that enables the discrimination of similar spatial locations. This process is vulnerable to pathophysiological changes in the early stages of Alzheimer’s disease (AD), but the translational potential of its testing remains unclear. This study aimed to evaluate the potential of SPS testing as a translational cognitive marker for identifying early AD and enabling direct comparisons of cognitive outcomes in animals and humans. We used a validated SPS task to examine biomarker-defined participants with amnestic mild cognitive impairment due to AD (AD aMCI; n = 56) and cognitively normal (CN) participants ( n = 60). An animal version of this task, based on a modified Morris Water Maze task, was used to test six-month-old transgenic TgF344-AD rats ( n = 38) and wild-type (WT) rats ( n = 36). AD aMCI participants performed worse than CN participants, with performance declining as distance decreased. These results remained unchanged when adjusted for memory performance. TgF344-AD rats performed worse than WT rats in a probe trial with a 90° SPS design, but not in probe trials with an 180° SPS design or no SPS demands. The discriminatory power of the task was similar in the human and animal experiments. The findings demonstrate comparable SPS deficits in the early stages of AD in both humans and rodent models, which are not attributable to general memory impairment. SPS testing enables direct comparisons to be made between the cognitive performance of rats and humans, making it a promising approach for translational AD research.
Sociodemographic determinants of willingness to adopt surveillance technology and mosquito control training for dengue in Malaysia
An examination of the impact of carbon emissions trading on corporate green technology innovation from the perspective of supply chain integration
Lesion-remote astrocytes govern microglia-mediated white matter repair
iHALT unlocks liver functionality as a surrogate secondary lymphoid organ
Deep learning with fourier features for regressive flow field reconstruction from sparse sensor measurements
Large-scale dynamos driven by shear-flow-induced jets
Prospective randomized trial of triple port laparoscopic cholecystectomy combined with choledochoscopic common bile duct exploration and primary closure for acute abdominal pain
Abstract To evaluate the clinical efficacy of laparoscopic common bile duct exploration (LCBDE) combined with choledochoscopy and primary closure without T-tube drainage in managing acute abdominal pain caused by choledocholithiasis (common bile duct stones, CBDS) and cholecystolithiasis with acute cholecystitis. A single-center prospective study was conducted at the Department of General Surgery, Beijing Fengtai Youanmen Hospital, from April 2024 to February 2025. Sixty-one patients with acute abdominal pain due to CBDS and cholecystolithiasis with acute cholecystitis were randomized into two groups: T-tube-free group (n = 35), Triple-port laparoscopic cholecystectomy (LC) + LCBDE with primary closure; T-tube group (n = 26), Four-port LC + LCBDE with T-tube drainage. Perioperative outcomes were compared between the groups. Baseline characteristics were comparable (all P > 0.05). The T-tube-free group demonstrated superior outcomes in operative time, intraoperative blood loss, postoperative pain, duration of abdominal drainage, and hospital stay (all P < 0.05). Each group had one case of biliary leakage, both resolved conservatively. No mortality, pancreatitis, conversion to open surgery, residual stones, biliary hemorrhage, or strictures occurred in either group. Triple-port LC combined with LCBDE and primary closure without T-tube drainage is safe and feasible for acute abdominal pain. Compared to T-tube drainage, this approach better aligns with the principles of enhanced recovery after surgery (ERAS).