Combustion Research and Flow Technology (United States)

The current study is the first to analyse long-term costs following both available percutaneous arteriovenous fistula (pAVF) devices and the surgical comparator (sAVF), based on prospectively collected data from a single vascular access centre in Germany. A decision-analytic model tracked reinterventions and costs by index modalities, with total cumulative reintervention burden derived from underlying Kaplan-Meier event rates of all consecutive reinterventions (including AVF-failure) reported over a 5-year analysis horizon. Strategy-specific costs per reintervention event were informed by claims data and number of reinterventions by follow-up year. Costs for initial AVF-creation were not accounted for. Study outcomes were the cumulative reintervention burden and costs. A total of 375 AVFs (217 pAVFs and 158 sAVFs) were followed. 212/375 patients underwent reinterventions without significant differences in the mean number of secondary procedures, as previously reported (0.60, 0.61 and 0.69 reinterventions per-patient-year for sAVF, WavelinQ pAVF and Ellipsys pAVF groups, respectively (p = 0.98)). Costs per reintervention varied depending on reintervention approach and complexity between €2016 and €11,554. The projected total number of reinterventions at 5 years was somewhat higher with the pAVF modalities (1.97 and 1.94 events at 5 years with Ellipsys and WavelinQ-pAVF, respectively, compared to 1.69 events with sAVF). Projected cumulative follow-on costs were however numerically lowest for Ellipsys-pAVF (€5780), followed by sAVF (€6036) and WavelinQ-pAVF (€6711) based on the different types of reinterventions and lower rates of access abandonment. Long-term maintenance costs are substantial for both sAVFs and pAVFs and do not seem to differ materially between percutaneous and surgical AVFs, despite some observed differences in procedure complexity that might benefit percutaneous AVF. Further study and future developments in pAVF technology including a further reduced reintervention burden and lower-cost pAVF-devices are warranted to increase the application of pAVF technology in haemodialysis patients.

Amandemen UUD 1945 membawa perubahan signifikan dalam sistem ketatanegaraan Indonesia, dari sentralistik menuju desentralistik melalui penerapan otonomi daerah. Meskipun demikian, berhubung pemerintahan daerah adalah bagian dari pemerintah pusat, kewenangan pembentukan Peraturan Daerah (Perda) tetap diawasi oleh pemerintah pusat melalui mekanisme fasilitasi dan harmonisasi. Sejalan dengan perkembangan teknologi, Pasal 97B UU No. 15 Tahun 2022 membuka ruang digitalisasi dalam proses pembentukan peraturan perundang-undangan. Dalam konteks ini, pemerintah mengembangkan dua platform digital, yaitu e-Harmonisasi dan e-Perda. E-Harmonisasi digunakan oleh Kementerian Hukum untuk mendukung administrasi proses harmonisasi di tingkat pusat, sedangkan e-Perda dikelola oleh Kementerian Dalam Negeri untuk mempercepat fasilitasi pembentukan Perda secara digital. Kedua sistem ini telah meningkatkan efisiensi, ketertiban dokumentasi, dan komunikasi antarpemerintah. Namun, masih terdapat keterbatasan, seperti akses terbatas ke aplikasi, tantangan aksesibilitas dari daerah terpencil ke pusat, serta belum optimalnya fitur analisis substansi norma, terutama dalam mendeteksi konflik atau duplikasi peraturan. Oleh karena itu, tulisan ini akan membahas kewenangan pembentukan peraturan daerah dalam kerangka negara kesatuan, pemanfaatan teknologi dalam proses harmonisasi dan fasilitasi peraturan daerah, dan rancang bangun pelaksanaan pengawasan pembentukan peraturan daerah yang berbasis teknologi.

This study presents experimental shock tube laser absorption spectroscopy data to validate high-pressure and high-temperature chemical kinetic mechanisms for mixtures of H2/air, NH3/air, and H2/CO/NO2/air diluted in argon (95-98%) at high pressures (5, 10, 25 bar) and high temperatures (1000 to 2150 K). The mixtures were at equivalence ratios of 0.5, 1.0, and 1.5 to cover the range of possible conditions experienced throughout practical combustors. Laser absorption spectroscopy data was measured for NH3, H2O, CO, and NO using a novel multi-species setup. Chemical kinetic mechanisms contain the fundamental chemistry used in reactive computational fluid dynamic (CFD) modeling of propulsion systems. Validation of these mechanisms through fundamental combustion chemistry experiments is essential to ensure the accuracy and efficiency of CFD simulations. The current chemical kinetic mechanisms regarding the combustion of H2, NH3, and syngas have not been extensively validated at the high-temperature and high-pressure conditions commonly experienced in combustors. Thus, speciation data was collected on the consumption of NH3 and formation of H2O for the NH3/air mixtures, the formation of H2O for the H2/air mixtures, and the formation of H2O and NO and consumption of CO for the H2/CO/NO2/air mixtures. This study provides data for mechanism validation through the collection of experimental shock tube laser absorption spectroscopy data.

This study presents the design and development of a low-power communication algorithm for optimizing energy consumption in wireless sensor networks (WSNs) deployed in solar-powered streetlights.The system utilizes ESP32 microcontrollers integrated with INA219 sensors and LoRa modules to measure and transmit data from streetlights.A dynamic clustering algorithm elects the node with the highest battery voltage as the cluster head (CH) to aggregate and forward data from other nodes to a central receiver, while the non-cluster head nodes enter deep sleep mode after transmission, reducing redundant communications and conserving energy.The performance of the clusteringbased transmission was compared against direct transmission in terms of energy consumption during data exchange.Results demonstrate a 49.45% reduction in energy consumption using the clustering approach compared to direct transmission, confirming its effectiveness for extending the operational lifespan of WSN nodes in energy-constrained environments.This solution offers an energy-efficient communication strategy for smart streetlight systems.

This study describes the design and optimization of two airfoil geometries intended for low Reynolds number rotary wing applications. The design methodologies used to produce these new airfoil designs are discussed; the first design method involves genetic optimization, while the other uses gradient-based optimization. The aerodynamic performance characteristics of the airfoils were assessed through a series of wind-tunnel experiments. The results indicated that a greater than 80% improvement in endurance factor was achieved for the select blade-integrated design conditions, as compared to a modern benchmark airfoil. The study also compared experimental results with those produced by the flow simulation frameworks used in the design process, such as MSES and OVERFLOW. It was found that OVERFLOW closely matched the experimental data, while MSES overestimated the endurance factor and maximum lift coefficient. The outcome of this study demonstrates that, despite differences in design approach and resulting geometric shape, two independently designed airfoils optimized with the same objective function exhibit consistent maximum endurance factor performance characteristics.

technology is a key renewable energy source worldwide and improving its efficiency is essential. Solar trackers are effective in enhancing this efficiency. This paper discusses the design and prototyping of a solar tracking system for floating solar panel installations, aimed at increasing power output. The system employs an Arduino Uno microcontroller for control, two light-dependent resistors (LDRs) for sunlight detection, a real-time clock (RTC) for day-night detection, an L298n motor driver for motor control, and a linear actuator to adjust panel orientation. Experimental results show that the tracked floating solar panel system boosts power output by up to 28.25% compared to stationary systems. The study highlights the importance of solar tracking in optimizing PV system efficiency and overcoming the limitations of fixed installations. Statistical analysis, with a t-test P-value of 0.03, confirms the significant improvement in power harvest with the tracked system.

This study uses LiDAR derivatives and Landsat 8 OLI/TIRS for yield estimation of major crops in Butuan City, Agusan del Norte, Philippines.Yield estimation is crucial for crop management, food security, and economic impact.Remote sensing techniques and GIS were used for crop yield estimation. eCognition software classified photos, while LiDAR derivatives like Canopy Height Model (CHM), Digital Surface Model (DSM), and Normalized Digital Surface Model (nDSM) were produced.Vegetation objects were classified into High, Medium, and Low Elevation Groups based on LiDAR nDSM heights.Regression analysis developed the allometric equation for yield estimation.The study achieved 94.36% overall accuracy in map classification and yield estimations of 84.5% for banana, 87.9% for coconut, 72.5% for corn, and 86.4% for mango.Average production was 58.414 tons/ha for bananas, 1,001.15tons/ha for coconut, 8.48 tons/ha for corn, and 1.256 tons/ha for mango.

This study describes the design of two airfoil geometries intended for low Reynolds number rotary wing applications. The design methodologies used to produce two new airfoil designs are discussed; the first design method involves genetic optimization, while the other utilizes gradient-based optimization. The resulting airfoils differ significantly in shape, although both feature a high camber design which facilitates higher maximum lift and hence higher design lift coefficient. The aerodynamic characteristics of the airfoils were identified through a series of wind tunnel experiments. The results indicated that a greater than 80% improvement in endurance factor under design conditions was achieved as compared to the benchmark airfoil. The study also compared the experimental results with flow simulation frameworks used in the design process, showing their viability despite limitations in predictive capabilities at certain operating conditions. This research provides useful insights into airfoil design and optimization for rotary wing applications.

BackgroundIn the recent Evolut Low Risk randomized trial, transcatheter aortic valve implantation (TAVI) was shown to be non-inferior to surgery (SAVR) regarding the composite end point of all-cause mortality or disabling stroke at 24 months.AimsTo evaluate the cost-effectiveness of self-expandable TAVI in low-risk patients, using the French healthcare system as the basis for analysis.MethodsMortality, health-related quality of life, and clinical event rates through two-year follow-up were derived from trial data (N = 725 TAVI and N = 678 SAVR; mean age: 73.9 years; mean STS-PROM: 1.9%). Cost inputs were based on real-world data for TAVI and SAVR procedures in the French healthcare system. Costs and effectiveness as quality-adjusted life years (QALYs) were projected to lifetime via a decision-analytic model under assumption of no mortality difference beyond two years. The discounted incremental cost-effectiveness ratio (ICER) was evaluated against a willingness-to-pay threshold of €50,000 per QALY gained. Deterministic and probabilistic sensitivity analyses were conducted, including assumptions about differential long-term survival.ResultsFor the base case, mean survival was 13.69 vs 13.56 (+ 0.13) years for TAVI and SAVR, respectively. Discounted QALYs were 9.34 vs. 9.21 (+ 0.13) and discounted lifetime costs €52,267 vs. €51,433 (+ €833), resulting in a lifetime ICER of €6368 per QALY gained. In probabilistic sensitivity analysis, TAVI was found dominant or cost-effective in 74.4% of samples.ConclusionTAVI in patients at low surgical risk is a cost-effective alternative to SAVR in the French healthcare system. Longer follow-up data will help increase the accuracy of lifetime survival projections.Graphical