Low Utilization Rate Research Articles

Evaluation of Self-vision Assessment Charts in Schools of Eastern Nepal: A Multi Method Study

Introduction: Globally, over two billion people suffer from vision impairment, almost half preventable. In Nepal, the Eastern Regional Eye Care Program introduced self-vision assessment charts in 137 schools for early eye issue detection. This study assessed the charts' use and perceived impact.Methods: A multi-method study was conducted to evaluate the use of self-vision assessment charts in schools in Eastern Nepal. Ethical approval was obtained from Institutional Review Board (Refrence number: 72-079-040). Quantitative data were collected through a questionnaire survey. Quantitative data were analyzed using descriptive statistics, while qualitative data were analyzed using framework analysis. Both methods were integrated to enhance understanding of participants' experiences.Results: In this study, 400 students participated in questionnaire survey, 180 in self vision assessment, and 16 teachers in in-depth interviews. Among the participants, 198 (49.50%) of students used the chart, 125 (65.78%) expressed satisfaction, 241 (60.25%) found it useful, 276 (69%) as beneficial, and 253 (63.25%) stated improved health. There were 93 (23.25%) students who felt knowledgeable about its use, with 18 (10%) using it correctly. In 162 (90%) of schools there were adequate chart placement, 23 (12.77%) provided clear signage for viewing points. Teachers recognized the chart's benefits and encouraged its use, but students lacked awareness. Regular use was viewed as beneficial for early detection of eye issues, though challenges included a need for more awareness among students and teachers and reliance on home remedies.Conclusions: Most students and teachers acknowledged self-vision assessment charts’ benefits but had low utilization and accuracy rates. Strategic interventions such as regular informational sessions, teacher motivation, and engagement with eye health experts are essential.

Optimal Configuration of Electricity-Heat Integrated Energy Storage Supplier and Multi-Microgrid System Scheduling Strategy Considering Demand Response

Shared energy storage system provides an attractive solution to the high configuration cost and low utilization rate of multi-microgrid energy storage system. In this paper, an electricity-heat integrated energy storage supplier (EHIESS) containing electricity and heat storage devices is proposed to provide shared energy storage services for multi-microgrid system in order to realize mutual profits for different subjects. To this end, electric boiler (EB) is introduced into EHIESS to realize the electricity-heat coupling of EHIESS and improve the energy utilization rate of electricity and heat storage equipment. Secondly, due to the problem of the uncertainty in user-side operation of multi-microgrid system, a price-based demand response (DR) mechanism is proposed to further optimize the resource allocation of shared electricity and heat energy storage devices. On this basis, a bi-level optimization model considering the capacity configuration of EHIESS and the optimal scheduling of multi-microgrid system is proposed, with the objectives of maximizing the profits of energy storage suppliers in upper-level and minimizing the operation costs of the multi-microgrid system in lower-level, and solved based on the Karush-Kuhn-Tucker (KKT) condition and Big-M method. The simulation results show that in case of demand response, the total operation cost of multi-microgrid system and the total operation profit of EHIESS are 51,687.73 and 11,983.88 CNY, respectively; and the corresponding electricity storage unit capacity is 9730.80 kWh. The proposed model realizes the mutual profits of EHIESS and multi-microgrid system.

Design and Testing of an Offset Straw-Returning Machine for Green Manures in Orchards

In order to solve the problems of traditional orchard-specific green manure crushing and returning machines, such as the single operation effect, root system damage, unsustainable green manure growth, and low utilization rate, an offset crushing–furrowing–burying–straw-returning machine was designed for green manures in orchards. Based on quadratic regression combination experiments, the Discrete Element Method (EDEM) was used to construct a discrete element model simulating the deep furrowing and burying processes of the furrowing and soil-covering device, where the advance speed, plow-shaped furrowing blade rotation speed, and furrowing depth were considered as experimental factors and the coverage rate was taken as an evaluation index, and then simulation analyses were carried out to obtain experimental data; Design-Expert was used to perform ANOVA and RSM analyses, thus finding that its optimal working parameter portfolio consists of the advance speed of 42 m/min, the furrowing blade rotation speed of 300 r/min, and the furrowing depth of 190 mm, and that the coverage rate is 95.82% when this parameter portfolio is applied. Field experiments were conducted to validate the optimal parameter portfolio. The experimental results show that with an average coverage rate of 90.87% (4.95% away from the optimal value based on the simulation experiments on average), an average crushing length qualification rate of 91.24%, and an average root system damage rate of 5.6%, this device is applicable for its operation conditions. The development of this machine and the construction of its parameter model can provide a certain reference value for developing and optimizing related machines including green manure-returning machines.

Transcatheter vs. surgical aortic valve replacement in patients with aortic stenosis and cardiogenic shock.

Patients with aortic stenosis (AS) and cardiogenic shock (CS) are an extremely high-risk population with a poor prognosis in the absence of definitive therapy. We aimed to compare the outcomes of transcatheter aortic valve replacement (TAVR) with those of surgical aortic valve replacement (SAVR) in patients with AS-CS. We queried the Nationwide Readmission Database (2016-21) to identify patients hospitalized for AS-CS who underwent isolated TAVR or SAVR. In-hospital outcomes of TAVR vs. SAVR were compared using multivariable regression and propensity-matching analyses. Ninety-day readmissions were compared using a Cox proportional hazards regression model. A total of 16 161 patients were hospitalized for AS-CS, of whom 6470 (40.0%) underwent isolated TAVR and 9691 (60.0%) underwent isolated SAVR. From 2016 through 2021, the proportion of TAVR increased from 29.5 to 46.5% and the proportion of SAVR correspondingly decreased in AS-CS (Ptrend < 0.01). After adjustment for baseline characteristics, TAVR was associated with lower odds of stroke [adjusted odds ratio (aOR) 0.63, 95% confidence interval (CI) 0.47-0.84], acute kidney injury (aOR 0.80, 95% CI 0.69-0.93), and major bleeding (aOR 0.54, 95% CI 0.40-0.71) and higher odds of vascular complications (aOR 1.56, 95% CI 1.23-1.97) compared with SAVR. In-hospital mortality, myocardial infarction, permanent pacemaker placement, and 90-day all-cause and heart failure readmissions showed similar rates between TAVR and SAVR. However, hospital length of stay was shorter and total costs and non-home discharges were lower with TAVR than with SAVR. This nationwide observational analysis showed that TAVR is increasingly performed in patients with AS-CS and is associated with similar rates of in-hospital mortality and 90-day readmissions but lower rates of in-hospital complications and resource utilization compared with SAVR.

Longitudinal analyses (2018-2022) of the COVID-19 impact on Swiss pediatric healthcare utilization

Abstract Background The impact of COVID-19 on healthcare utilization in the early pandemic is well documented. However, studies on changes in both primary and tertiary pediatric healthcare utilization that considered data beyond the first pandemic year is lacking. Methods National health insurance data (primary care) and pediatric emergency department data (tertiary care) from Jan. 2018 - June 2022 and on 0-18-year-olds were analyzed with interrupted time series. The first lockdown was used to differentiate between pre-pandemic and pandemic periods. Results Several healthcare services yielded significantly lower average utilization rates during the pandemic vs. the pre-pandemic period, particularly in the youngest age groups. In primary care, the relative utilization, compared to the pre-pandemic mean, dropped in regards to regular (0-5y: 0.760 [0.644-0.896]; 6-10y: 0.850 [0.742-0.974]), well-child (0-5y: 0.871 [0.765-0.992]), and urgent visits (0-5y: 0.638 [0.500-0.813]; 6-10y: 0.810 [0.665-0.985]), and for the vaccination against measles/mumps/rubella (MMR; 0-5y: 0.841 [0.729-0.971]). Similarly, in tertiary care, this pattern emerged for non-urgent (Zurich: 0.55 [0.482-0.627]; Geneva: 0.526 [0.435-0.636]; Ticino: 0.502 [0.436-0.578]) and urgent visits (Zurich: 0.573 [0.498-0.659]; Geneva: 0.487 [0.375-0.632]; Ticino: 0.676 [0.57-0.802]). The utilization rates of most services dropped markedly after the lockdown and recovered to some extent over the pandemic phase. However, no recovery was found for the MMR-vaccination. In primary care, higher average utilization rates during the pandemic were identified for telephone consultations (0-5y: 1.394 [1.218-1.594]; 6-10y: 1.547 [1.387-1.726]; 11-15y: 1.578 [1.430-1.741]; 16-18y: 1.831 [1.614-2.076]). Conclusions The pandemic’s effect on utilization seemed to have occurred temporarily, but it cannot be ruled out that some children have not fully caught up on preventative measures (well-child visits and MMR-vaccinations). Key messages • Pediatric healthcare utilization dropped considerably immediately after the lockdown, with the most pronounced decrease observed in the youngest children. • The heterogenous recovery over the pandemic period points to the necessity to continue to monitor utilization rates, catch-up visits, and vaccination statistics.

The clinical characteristics and prognosis of patients with acute ST-segment elevation myocardial infarction complicated with impaired activity daily living

Abstract Background Previous studies have indicated that activities of daily living (ADL) can influence the prognosis of patients with acute myocardial infarction. The purpose of this study is to delineate the clinical characteristics, treatment regimens, and prognosis of patients with acute ST-segment elevation myocardial infarction (STEMI) who have impaired ADL. Methods The data for this study were derived from a Health and Medical Big Data Superplatform, comprising a retrospective cohort of patients admitted to and discharged from 72 secondary and tertiary hospitals from 2010 to 2023. The inclusion criteria encompassed patients with a discharge diagnosis of STEMI.ADL prior to STEMI was evaluated using the Barthel index(BI),a widely used assessment tool for evaluating ADL.The patients' BI were obtained from their resident health records.Patients were categorized into two groups: ADL normal group and ADL impaired group. A comparative analysis was conducted between the two groups regarding clinical characteristics, treatment regimens, and prognosis. Results This study included 24,906 STEMI patients with normal ADL and 1,002 STEMI patients with impaired ADL. Baseline data revealed that patients in the ADL impaired group had a higher proportion of females (43.0% vs. 37.8%, p=0.001), were older (74.0[64.0,81.0] vs. 69.0[65.0,75.0], p&amp;lt;0.001), and had a higher proportion of Killip III and above (24.30% vs. 14.10%, p&amp;lt;0.001). Additionally, the ADL impaired group had a higher prevalence of comorbidities. In terms of treatment, the ADL impaired group had lower proportions of patients undergoing percutaneous coronary intervention (PCI) (43.8% vs. 65.3%, p&amp;lt;0.001) and primary PCI (PPCI) (36.4% vs. 55.1%, p&amp;lt;0.001). Additionally, the ADL impaired group exhibited lower utilization rates of antiplatelet drugs, ACEI/ARB, beta-blockers, ARNI, and statins, but higher rates of diuretics and cardiac glycosides. Regarding prognosis, the ADL impaired group had a higher in-hospital mortality rate (5.69% vs. 2.89%, p&amp;lt;0.001). The median follow-up time was 1,220 days. In the ADL impaired group, the rates of all-cause mortality (52.0% vs. 24.7%, p&amp;lt;0.001), cardiovascular mortality (37.3% vs. 17.3%, p&amp;lt;0.001), recurrent non-fatal myocardial infarction (11.1% vs. 8.30%, p=0.002), and recurrent stroke (11.9% vs. 8.66%, p=0.001) were higher. However, the rate of revascularization was lower in the ADL impaired group (6.69% vs. 9.20%, p=0.008), and the risk of cerebral hemorrhage showed no significant difference (1.00% vs. 0.81%, p=0.631). In a multivariate Cox regression analysis adjusting for age, gender, Killip, medical history, and treatment strategies, impaired ADL remained an independent risk factor for increased all-cause mortality (aHR 1.309, 95% CI: 1.195-1.434, p&amp;lt;0.001). Conclusions Impairment of ADL is associated with adverse clinical outcomes in patients with STEMI.Baseline characteristics of patientsMedications of patients

The clinical characteristics and prognosis of patients with acute non-ST-segment elevation myocardial infarction complicated with impaired activity daily living

Abstract Background Impaired activities of daily living (ADL) have been identified as an independent risk factor for cardiovascular diseases. This study aims to describe the clinical characteristics, treatment modalities, and prognosis of acute non-ST-segment elevation myocardial infarction (NSTEMI) patients with impaired ADL. Methods The data for this study were derived from a Health and Medical Big Data Superplatform, comprising a retrospective cohort of patients admitted to and discharged from 72 secondary and tertiary hospitals from 2010 to 2023. The inclusion criteria encompassed patients with a discharge diagnosis of NSTEMI.ADL prior to NSTEMI was evaluated using the Barthel index(BI),a widely used assessment tool for evaluating ADL.The patients' BI were obtained from patients’ resident health records, and patients were categorized into two groups: ADL normal and ADL impaired group. A comparative analysis was conducted between the two groups regarding clinical characteristics, treatment regimens, and prognosis. Results The study included 28,227 NSTEMI patients with normal ADL and 1,576 NSTEMI patients with impaired ADL. Baseline data revealed that the ADL impaired group had a higher proportion of females (49.4% vs. 43.2%, p &amp;lt; 0.001), older age (77.0 [69.0, 83.0] vs. 71.0 [66.0, 78.0], p &amp;lt; 0.001), and a higher proportion of patients with KILLIP III and above (25.86% vs. 17.44%, p &amp;lt; 0.001). Additionally, the ADL impaired group had a greater number of pre-existing comorbidities. Regarding treatment, the proportion of patients undergoing percutaneous coronary intervention (PCI) was significantly lower in the ADL impaired group (16.5% vs. 65.3%, p &amp;lt; 0.001). Moreover, the ADL impaired group showed lower utilization rates of antiplatelet agents, ACEI/ARBs, beta-blockers, ARNI, statins, and nitrates, while the utilization rates of diuretics and cardiac glycosides were higher. In terms of prognosis, the ADL impaired group exhibited a higher in-hospital mortality rate (6.03% vs. 3.35%, p &amp;lt; 0.001). During a median follow-up period of 876 days, the ADL impaired group had significantly higher rates of all-cause mortality (61.2% vs. 35.9%, p &amp;lt; 0.001) and cardiovascular mortality (41.8% vs. 24.8%, p &amp;lt; 0.001), while the rate of revascularization (6.69% vs. 9.20%, p = 0.008) was lower. There were no significant differences in the risks of recurrent non-fatal myocardial infarction (10.7% vs. 10.8%, p = 0.935), recurrent stroke (10.90% vs. 9.48%, p = 0.08), and hemorrhagic stroke (0.82% vs. 0.74%, p = 0.806). Following adjustment for age, gender, KILLIP classification, medical history, and treatment strategies in a multivariable Cox regression analysis, impaired ADL remained an independent risk factor for increased all-cause mortality (aHR 1.167, 95%CI: 1.091-1.249, p &amp;lt; 0.001). Conclusions The decline in ADL is significantly associated with adverse clinical outcomes among NSTEMI patients.Baseline characteristics of patientsMedications of patients

Effect of cannabis use history on postoperative opioid utilization in lumbar fusion patients: an American retrospective study.

A retrospective cohort study. To examine the effect of cannabis use history on postoperative opioid utilization in patients undergoing one- to three-level lumbar fusion for degenerative spine disease. Strategies to minimize dosing and chronic opioid use are needed for spine surgery given their widespread prescription for postsurgical pain management. In this database study, medical coding was used to identify patients who had undergone one- to three-level lumbar fusions between 2012 and 2021. Propensity score matching was used to create two equal cohorts with respect to cannabis use history. Opioid utilization rates (morphine milligram equivalents [MME]/day) and overuse rates at 6 months post-index procedure were assessed. All pvalues <0.05 were considered statistically significant. Following examination of 153,500 patient records, 1,216 patients were matched into cannabis user and non-cannabis user cohorts. Cannabis users had lower rates of opioid utilization compared to non-cannabis users as early as 2 months after fusion (47.7% vs. 41.1%, p <0.05), a relationship which persisted at 6 months (46.2% vs. 37.7%, p <0.01). Additionally, cannabis users had lower rates of high-dose opioid utilization (≥100 MME per day) during the initial 14-30 days following surgery (6.91% vs. 3.79%, p <0.05). Patients with a history of cannabis use were less likely to be using opioids as early as 2 months postoperatively and had lower rates of high-dose opioid utilization in the immediate postoperative period. Physicians operating on these patients should consider their cannabis use patterns to provide appropriate titration of pain medication over time.

Non-used cryopreserved sperm among oncological patients: extra-long-term follow-up and analysis.

To investigate factors influencing long-term utilization and disposal patterns of cryopreserved semen straws in oncological patients. This retrospective study included all men who cryopreserved semen due to cancer between October 1993 and December 2021. To assess non-used cryopreserved sperm straws, we investigated the following parameters: cryopreserved semen and usage for fertility treatments versus disposal, summarized by total non-used cases. A Kaplan-Meier curve was used to describe last usage and disposal requests over a 15-year analysis. A Log-rank test was applied to compare between age and paternal status categories. The cohort consisted of 445 patients. Of these, 55 patients utilized thawed semen for fertility treatments, and 65 opted for disposals, leaving 325 patients who neither used nor disposed of their cryopreserved straws. Our findings revealed a distinct pattern based on age, with the youngest age group (< 25 years) exhibiting significantly lower utilization and disposal rates compared to older patient groups. Additionally, men without children exhibited significantly fewer disposal requests compared to fathers. The median cryopreserved straws were 10 (interquartile range, 6 to 17), while the median used straws were only 2 (interquartile range, 2 to 6). Our study brings attention to the additional and needless burden of preservation from both patient and preserved straw perspectives. Implementing a policy based on a cost-effective approach, incorporating time and straw limits, and considering demographic characteristics, could enhance efficiency and necessitate patient consent before preservation.

Synergetic construction of color and multifunction for sustainable lyocell fabric by Coptis chinensis and BTCA

In the context of escalating standards of living, the demand for healthy and multifunctional textiles is increasing. As a kind of cellulose macromolecular-based material, lyocell fiber has low carbon, is environmentally friendly, and demonstrates superb performance. The utilization of some Chinese herb dyes solves the pollution problem in the color and functionality construction of lyocell fabric by synthetic dyes and finishing agents. However, problems such as low dye utilization rate, light apparent color, and weak functionality of dyed fabrics remain, thus limiting the further application of the powerful combination of lyocell fabric and Chinese herb dyes. Here, a color and multifunction construction method of lyocell fabric with Coptis chinensis and 1,2,3,4-butanetetracarboxylic acid was proposed. Under the optimal color construction condition, the color depth increased remarkably, and the dye exhaustion rate of the modified fabric enhanced by 332.3 % compared with the unmodified one. The multifunction construction imparted outstanding fuzz and pilling inhibition, fibrillation resistance, and antiwrinkle performance for lyocell fabrics. Moreover, the dyed lyocell fabric exhibited considerable UV protective activity and antibacterial property against Staphylococcus aureus. This work provided an efficient color and multifunction construction technology for lyocell fabric with high value added.

BIF-Net: Boundary information fusion network for abdominal aortic aneurysm segmentation

The accurate abdominal aortic aneurysm (AAA) segmentation is significant for assisting clinicians in diagnosis and treatment planning. However, existing segmentation methods exhibit a low utilization rate for the semantic information of vessel boundaries, which is disadvantageous for segmenting AAA with significant scale variability of vessel diameter (diameter ranges from 4 mm to 85 mm). To tackle this problem, we introduce a boundary information fusion network (BIF-Net) specially designed for AAA segmentation. BIF-Net initially constructs convolutional kernel functions based on Gabor and Sobel operators, enriching the global semantic features and localization information through the Gabor and Sobel dilated convolution (GSDC) module. Additionally, BIF-Net supplements lost boundary feature information during the sampling process through the guided filtering feature supplementation (GFFS) module and the channel-spatial attention module (CSAM), enhancing the ability to capture targets with shape diversity and boundary features. Finally, we introduce a boundary feature loss function to alleviate the impact of the imbalance between positive and negative samples. The results demonstrate that BIF-Net outperforms current state-of-the-art methods across multiple evaluation metrics, achieving the highest Dice similarity coefficient (DSC) accuracies of 93.29 % and 91.01 % on the preoperative and postoperative datasets, respectively. Compared to the state-of-the-art methods, BIF-Net improves DSC by 6.86 % and 3.85 %. Due to the powerful boundary feature extraction ability, the proposed BIF-Net is a competitive AAA segmentation method exhibiting significant potential for application in diagnosis and treatment processes of AAA.

Stress-Strain Behavior and Strength Development of High-Amount Phosphogypsum-Based Sustainable Cementitious Materials.

Phosphogypsum is a common industrial solid waste that faces the challenges of high stockpiling and low utilization rates. This study focuses on the mechanical properties and internal characteristics of cementitious materials with a high phosphogypsum content. Specifically, we examined the effects of varying amounts of ground granulated blast furnace slag (5-28%), fly ash (5-20%), and hydrated lime (0.5-2%) on the stress-strain curve, unconfined uniaxial compressive strength, and elastic modulus (E50) of these materials. The test results indicate that increasing the ground granulated blast furnace slag content can significantly enhance the mechanical properties of phosphogypsum-based cementitious materials. Additionally, increasing the fly ash content can have a similar beneficial effect with an appropriate amount of hydrated lime. Furthermore, microscopic analysis of the cementitious materials using a scanning electron microscope revealed that the high sulfate content in phosphogypsum leads to the formation of calcium aluminate as the main product. Concurrently, a continuous reaction of the raw materials contributes to the strength development of the cementitious materials over time. The results could provide a novel method for improving the reusing phosphogypsum amount in civil engineering materials.

Life cycle environmental and economic assessment of Phosphogypsum utilization in China

Phosphogypsum (PG), a byproduct of the phosphate fertilizer industry, poses significant environmental challenges due to its huge production and complex composition. Efficient and large-scale utilization of PG remains a global issue. China, as the world's largest producer and discharger of PG, faces a relatively low utilization rate and urgently needs effective management strategies. This study evaluates the environmental and economic performance of the main PG treatment pathways in China using life cycle assessment (LCA). The results reveal notable benefits for all three utilization technologies, with sulfuric acid co-production cement (PSC) offering the greatest environmental advantages and β-building gypsum (PBG) providing the highest economic benefits. Scenario analysis suggests PSC as the most effective strategy for achieving dual environmental and economic gains, making it a strong candidate for large-scale implementation. These findings provide critical insights for future PG management strategies in China.

Oil-based drilling cutting pyrolysis residues- phosphogypsum foamed ceramics: Basic properties, microsintering mechanism and heavy metals solidification

Oil-based drilling cutting pyrolysis residues(ODPR) and phosphogypsum(PG) are typical types of industrial solid waste in China, characterized by low utilization rate and high output. The large amount of untreated accumulation will release heavy metals(HMs) and other pollutants, posing risks to the environment. Therefore, there is an urgent need to develop a high value-added building material product that can reduce environmental hazards while improving utilization rate. Based on this background, this study uses ODPR and PG as raw materials to explore their potential applications in the field of foamed ceramics. Research has shown that different sintering processes have a significant impact on the appearance and performance of products. By adjusting the preparation process, foamed ceramic products with excellent performance can be prepared. When the sintering temperature is 925℃, the foaming agent dosage is 3 %, and the raw material ratio ODPR:PG:Borax=35:45:20, a foamed ceramic product with a porosity of 60.95 %, water absorption rate of 3.4 %, compressive strength of 4.8 MPa, thermal conductivity of 0.8016 W/(m·k), and acid and alkali resistance of 98.57 % and 99.44 % can be prepared. The product meets the relevant requirements of “Fired heat preservation brick and block (GB/T 26538)” and “ General Specification for porous ceramic products (GB/T 16533)”. The HMs content test showed that the Ni and Pb contents in the pre-sintered blanks were the highest, at 0.6308 mg/kg and 0.3182 mg/kg, respectively. However, after high-temperature calcination, the solidification rate of HMs could reach up to 98.93 %, and the leaching amount was significantly reduced. The three further evaluation methods indicate that HMs in the pre-sintered blanks and foamed ceramic products do not pose significant ecological risks. The research results provide a green inorganic insulation material in the field of solid waste control and building materials.

Exploring the Potential of the Hyperspectral Remote Sensing Data China Orbita Zhuhai-1 in Land Cover Classification

Responding to the shortcomings of China's civil remote sensing data in land cover classification, such as the difficulty of data acquisition and the low utilization rate, we used Landsat-8, China Orbita Zhuhai-1 hyperspectral remote sensing (OHS) data, and Landsat-8 + OHS data combined with band (red, green, and blue) and vegetation index features to classify land cover using maximum likelihood (ML), Mahalanobis distance (MD), and support vector machine (SVM). The results show that Landsat-8 + OHS data have the highest classification accuracy in SVM, with an overall accuracy of 83.52% and a kappa coefficient of 0.71, and this result is higher than that of Landsat-8 images and OHS images separately. In addition, the classification accuracy of OHS images was higher than that of Landsat-8 images. The results of the study provide a reference for the use of civil satellite remote sensing data in China.

Fair Competition Review System and cross-regional capital flow: Evidence from China

Breaking local protectionism and market segmentation to promote the free flow of production factors between regions is crucial for building a unified national market in China. Introduced in 2016, the Fair Competition Review System (FCRS) restricts local governments’ abuse of administrative power to limit competition. The system corrects market failures and weakens regional barriers, establishing market competition by evaluating policies and regulations for anti-competitive practices. This study investigated the impact of the FCRS on cross-regional capital flow through subsidiaries in different regions. Using data from Chinese-listed companies between 2011 and 2022, this empirical study found that capital flow significantly increased after the system's implementation. Cross-regional flow was stronger in areas with higher reduced administrative barriers, lower tax burdens, and lower capacity utilization rates. This suggests that the primary mechanisms driving capital flow were expansion and cost-efficiency improvements. Heterogeneity tests indicate that the system exhibited a stronger impact on promoting cross-regional capital flow for private enterprises and those with low investment efficiency and weaker profitability. These findings suggest that the FCRS effectively regulates administrative monopolies, reduces regional barriers, and facilitates freer capital flow between regions, contributing to a unified national market in China.

Deployment of Public Charging Stations for BEVs Using an Agent-Based Modeling Approach

A low utilization rate of public chargers and unmatched deployment of public charging stations (CSs) are partly attributed to inappropriate modeling of charging behavior and biased charging demand estimation. This study proposes an optimization methodology for public CS deployment, considering real charging behavior and interactions between battery electric vehicle (BEV) users and CSs. Realistic charging choice behavior is modeled based on surveys, and a dynamic charging decision chain is simulated, allowing interactions between BEV users and CSs through an agent-based modeling (ABM) approach. The charging-related activities are triggered by state of charge (SOC) levels randomly generated from distributions derived from real BEV operating data, including the random SOC levels at the start of a trip, the SOC level that prompts the user to charge the BEV, and the SOC level at which the user stops charging the BEV. A bi-level programming model is proposed to optimize the deployment schemes for building new CSs considering the existing CSs, to determine the location and the capacity of new CSs. The objective is to minimize the total time cost per BEV user, including travel time, charging time and waiting time in the queue. An application is conducted, for the deployment of fast CSs in Washington State, USA. The results show that our method could provide effective guidance for allocating new CSs that are good supplements to the existing heavy-load CSs to share their charging load and relieve their serious queuing problems. The optimized deployment scheme can efficiently alleviate long waiting times at existing CSs and leads to a more balanced utilization among CSs. The proposed approach is expected to contribute to better planning and deployment of public CSs, satisfaction of the booming charging demand and increased utilization of public CSs.

Numerical and experimental investigation on the operating characteristics of fan-shaped pulse detonation combustor

The internal flow channel of a turbine engine is typically annular. When circular pulse detonation combustors (PDCs) are installed in this channel, there is a problem with low section utilization rates. To solve this problem, a single-tube fan-shaped PDC test system was developed. The effects of ignition distance on the operating characteristics of the fan-shaped PDC using air and gasoline under different frequencies were studied through both experiment and 3-D numerical simulation. Numerical simulation was also used to investigate the formation and propagation characteristics of detonation waves. The results show that the fan-shaped PDC can operate stably at frequencies ranging from 5 to 25 Hz when the ignition distance is either 2.30 or 2.70 times the equivalent circle diameter from the thrust wall, and it is found to be better to ignite at a distance of 2.30 times the equivalent circle diameter. The blockage ratio of the lower arc surface is larger than that of the other surfaces. This results in more intense collision and reflection. A larger local high pressure area forms near the lower arc surface, which is conducive to the formation of detonation waves. However, the larger blockage ratio makes the flow loss larger, which weakens the intensity of the pressure waves near the lower arc surface. The detonation waves in the fan-shaped PDC travel closer to the upper arc surfaces.

Design and Testing of a Fruit Tree Variable Spray System Based on ExG-AABB

This paper addresses the issue of pesticide waste and low utilization rates resulting from traditional plant protection via spraying operations, which apply equal dosages to different targets or to different parts of the same target. To tackle this problem, we designed a variable fruit tree spraying system based on the ExG-AABB (excess green and axis-aligned bounding box) algorithm. We used a Kinect depth camera to capture information about the fruit tree canopy and constructed a spray flow model using pulse width modulation and variable spray control technology. Variable multi-nozzle spraying was guided by combining this canopy data. We evaluated the accuracy of each model in calculating canopy volume by comparing the coefficient of determination (R2) and root mean square error (RMSE) of the ExG-AABB with the slice convex hull method, voxel method, three-dimensional alpha-shape method, and QuickHull method. The ExG-AABB algorithm had the highest R2 value (0.9334) and the lowest RMSE value (0.0353 m3) among the five models, indicating that it most accurately reflects the true volume of the fruit tree canopy. This validates the effectiveness of the ExG-AABB algorithm in calculating canopy volume. We established a correlation model between canopy volume and spray volume, designed a canopy-adaptive layering method based on point cloud processing, and achieved precise calculation of nozzle flow. Comparative field experiments were conducted to analyze the spray coverage rate and observed flow, thereby evaluating the spraying effect of this variable spraying system. The experimental results showed that compared to conventional continuous spraying, this variable spraying system not only achieves more uniform spray coverage but also significantly reduces pesticide usage by 48.1%. Furthermore, through system optimization, the average coverage rate of the middle layer of the canopy decreased by 17.53%, effectively reducing the phenomenon of overlapping spraying from multiple nozzles and improving spraying efficiency.

Rapid investment casting: a techno-economic analysis for evaluating VAT photopolymerisation processes

Adopting additive manufacturing in investment casting, known as rapid investment casting, can significantly reduce lead time and cost. Despite many publications on these technologies, no quantitative techno-economic analyses refer to rapid investment casting. The paper provides helpful insights and a decision-making approach for replacing conventional production technologies (i.e. wax injection) with additive manufacturing technologies. The study is based on a techno-economic analysis framework. It allows assessing key performance indicators (e.g. crossover points and payback periods) for stakeholders to decide the suitable VAT photopolymerisation processes (i.e. stereolithography, digital light processing, and material jetting) according to specific production scenarios (i.e. load factors). Analytical cost models were developed in the frame of this work to assess the time and cost of the overall manufacturing process of the resin model for investment casting, considering the post-processing stages for each of the technologies investigated. The cost models were used to assess the benefits introduced by additive manufacturing in rapid investment casting. A sensitivity analysis evaluated the impact of energy, material, and labour costs for both key performance indicators (crossover points and payback periods). The techno-economic analysis yielded the following results: (i) crossover points in terms of production costs vary, ranging from thousands of units for small components in the jewellery or fashion industries to a few dozen units for larger parts in the mechanical industry, and (ii) crossover points in terms of time are lower than those related to cost. Additionally, digital light processing is regarded as the most promising technology, offering the best crossover points and payback periods across various scenarios, mainly when 3D printers are used at a low utilisation rate.