Area Ratio Research Articles

Prophylactic and therapeutic effects of EsV3 on atherosclerotic lesions in ApoE−/− mice

BackgroundAtherosclerosis (AS) is a major contributor to vascular disorders and represents a significant risk to human health. Currently, first-line pharmacotherapies are associated with substantial side effects, and the development of atherosclerosis is closely linked to dietary factors. This study evaluated the effects of a dietary supplement, EsV3, on AS in apolipoprotein E (ApoE) −/− model mice.MethodsThe study utilized a high-fat diet-induced ApoE−/− hyperlipidemic mouse model. EsV3 was administered in prophylactic (P-EsV3) and therapeutic regimens for 16 and 12 weeks, respectively, with distinct high- and low-dose groups (0.36 and 1.8 g/kg/day). Serum lipid levels were measured and monitored for body weight and food consumption alterations in murine models. Aortic oil red O staining was conducted to assess plaque formation and calculate the plaque-to-vessel area ratio. Liver tissue changes were examined via HE staining. Moreover, serum oxidative stress markers (MDA, GSH, SOD) were measured to evaluate oxidative damage and lipid metabolism.ResultsBoth atorvastatin and P-EsV3 treatments significantly lowered TC, TG, and LDL-C levels, with P-EsV3-H enhancing HDL-C levels (P < 0.05). Prophylactic EsV3 administration was more effective than therapeutic administration in regulating TG and LDL-C levels and had comparable effects to atorvastatin on TC and HDL-C. All treatment groups exhibited reduced body weight compared to the model group, with no significant differences in food intake. Additionally, EsV3 administration significantly reduced the aortic plaque area and liver lipid droplets compared to the model group, while mitigating oxidative stress, as evidenced by decreased MDA levels and increased SOD and GSH levels, with outcomes comparable to those observed with atorvastatin.ConclusionsIn ApoE−/− hyperlipidemic mice, EsV3 improved lipid profiles and reduced aortic plaque formation. EsV3's effects, attributed partly to its antioxidant properties, were comparable to atorvastatin, suggesting its potential as a preventive and therapeutic agent for hyperlipidemia and atherosclerosis.

GDF11 restores the impaired function of EPCs-MA by promoting autophagy: GDF11 ameliorates endothelial progenitor cell aging by promoting autophagy

Abstract Objective Our study aimed to assess the effects of Growth and differentiation factor 11 (GDF11) on the function of endothelial progenitor cells in middle-age individuals (EPCs-MA) isolated from mouse bone marrow and to explore the mechanistic relationship between GDF11 and age-related ALP impairment. Methods Bone marrow-derived EPCs were isolated, culture and GDF11 treatment. In vivo, the mice model of myocardial ischemia (MI) was induced by permanent ligation of the left anterior descending coronary artery (LAD) and mice were randomly divided into MI group and EPCs transplantation group (EPCs-Y, EPCs-MA, EPCs-MA/GDF11). The positive effect of GDF11 treatment of EPCs-MA on MI was verified by echocardiography and the average ratio of fibrotic area to left ventricular (LV) area. In vitro, the effect of GDF11 on ameliorating EPCs aging by promoting autophagy was confirmed by transwell assay, immunofluorescence staining, characterization of EPCs ultrastructure through transmission electron microscope (TEM), lysosome imaging and Western blot. Result Our findings demonstrate that GDF11 enhances the migration capacity of EPCs-MA and improves recovery of impaired cardiac function after myocardial infarction (MI) in mice, with EPCs isolated from young mice (EPCs-Y) as controls. Moreover, GDF11 restored functional phenotypes of EPCs-MA to levels akin to EPCs-Y, promoting the expression of CD31, endogenous NO synthase, and the restoration of von Willebrand factor (vWF) and CDH5 expression patterns, as well as the formation of Weibel-Palade bodies—key organelles for storage and secretion in endothelial cells and EPCs. Furthermore, GDF11 significantly enhanced the autophagic clearance capability of EPCs-MA by promoting ALP. Conclusions Our results suggest that GDF11 ameliorates cardiac function impairment by restoring the activities of EPCs from aging mice through enhanced ALP. These findings suggest that GDF11 may hold therapeutic potential for improving aging-related conditions associated with declined autophagy.

Comprehensive Characterization and Impact Analysis of Interlayers on CO2 Flooding in Low-Permeability Sandstone Reservoirs

In low-permeability sandstone reservoirs (LPSR), impermeable interlayers significantly challenge carbon capture, utilization, and storage (CCUS) and enhance oil recovery (CO2-EOR) processes by creating complex, discontinuous flow units. This study aims to address these challenges through a comprehensive multi-faceted approach integrating geological and microscopic analyses, including core analysis, reservoir petrography, field emission-scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and well-logging response analysis, and utilizing three-dimensional (3D) geological modeling. The current comprehensive investigation systematically characterizes interlayer types, petrophysical properties, thickness, connectivity, and their spatial distribution in the reservoir unit. Numerical simulations were conducted to assess the sealing efficiency and the impact of various interlayer materials on CO2 flooding over a 10-year period. Results indicate the presence of petrophysical and argillaceous interlayers, with optimal sealing occurring in petrophysical barriers ≥ 4 m and argillaceous barriers ≥ 1.5 m thick. CO2 leakage occurs through preferential pathways that emerge in a side-to-middle and bottom-to-top direction in interbeds, with multidirectional pathways showing greater leakage at the bottom compared to the upper side within barriers. Increased interlayer thickness constraints CO2 breakthrough but reduces vertical flooding area and production ratio compared to homogeneous reservoirs. Augmented interbed thickness and area mitigate CO2 breakthrough time while constraining gravity override and dispersion effects, enhancing horizontal oil displacement. These novel findings provide crucial insights for optimizing CCUS-EOR strategies in LPSR, offering a robust theoretical foundation for future applications and serving as a key reference for CO2 utilization in challenging geological settings of LPSR worldwide.

Lubrication and wear characteristics of bionic composite texture on friction pair under seawater condition

Abstract To improve the lubrication bearing capacity of the slipper pair of axial piston pump under seawater lubrication, a bionic composite texture (ball pit-ball convex) was designed based on the non-smooth surface structure of dung beetle, and friction and wear experiments were carried out with CF/PEEK and 316L stainless steel. Thirteen groups of experiments with different parameters and structure sizes were designed and studied. The surface morphology of materials under different structural sizes and test parameters were observed, and the lubrication and wear characteristics were analyzed. The results show that the cavitation effect can increase the total compressive capacity of the bionic composite texture by 51.2% and reduce the friction coefficient by 53.3%, and the diameter and area ratio of the ball pit have the most obvious influence on the bearing performance. It is also found that the bionic composite texture has better anti-friction performance than the single texture because it has the function of storing wear chips.

Prolonged Impact of Bisphosphonates and Glucocorticoids on Bone Mechanical Properties

Background: This study aimed at investigating the prolonged effects of glucocorticoids and bisphosphonates on bone. Methods: Six-to-eight-month-old skeletally mature male Sprague Dawley rats were randomized to receive a cancer therapy combination of zoledronic acid (ZA = 0.13 mg/kg) and dexamethasone (DX = 3.8 mg/kg) (treatment group, n = 10) or sterile phosphate buffer saline solution (control group, n = 10). The rats received weekly intraperitoneal injections for 8 weeks, which were stopped 6 weeks before euthanasia. Mineralized bone samples were characterized by three-point bending tests, micro-CT imaging, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Bone collagen was assessed using tensile tests on the demineralized bones and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy on mineralized and demineralized bones. Results: The samples in the treatment group showed increased tibial cortical thickness, mineral crystal size, and toughness. Analyses of demineralized tibiae revealed decreased collagen tensile strength in the experimental group. The spectroscopic and TGA/DSC analyses showed that the ZA + DX treatment increased the collagen amide I 1660/1690 cm−1 area ratio and collagen denaturalization temperature, indicating a higher level of collagen cross-linking. Conclusions: Bisphosphonates and glucocorticoids led to prolonged changes in the mechanical properties of bone as a result of increased cortical thickness, increased crystal size, and the deterioration of collagen quality.

Long-Term Greenness Effects of Urban Forests to Reduce PM10 Concentration: Does the Impact Benefit the Population Vulnerable to Asthma?

This study investigates the effect of urban forests in reducing particulate matter (PM) concentrations and its subsequent impact on the number of asthma care visits. Understanding the mechanisms behind the relationship between the greenness of blocking forests and the reduction in PM is crucial for assessing the associated human health benefits. This study analyzed the influencing factors for reducing long-term PM10 concentrations, utilizing the vegetation index and meteorological variables. Results showed that the reduction in PM10 began in 2011, five years after the establishment of the blocking forest. The annual mean PM10 concentrations decreased significantly, driven primarily by summer wind speed and summer Enhanced Vegetation Index (EVI), explaining approximately 62% of the variation. A decrease in the number of asthma care visits was observed, similar to the trend of PM10 reduction in the residential area and the increase in the greenness of the blocking forest. The influx of PM into the city, primarily driven by prevailing northwesterly winds, may have been mitigated by the growing blocking forest, contributing to a reduction in asthma-related medical visits among urban residents. In particular, since the onset of the COVID-19 pandemic in 2020, the increase in the PM2.5/PM10 ratio in residential areas has become more closely linked to the increase in asthma-related medical visits. It suggests another PM2.5 emission source in the residential area. The number of asthma care visits among children (under 11) and the elderly (over 65) exhibited a strong positive correlation with PM10 levels and a negative correlation with the Normalized Difference Vegetation Index (NDVI). This suggests a link between air quality improvement from the greenness of blocking forests with their capacity to capture PM and respiratory health outcomes, especially for the vulnerable groups to asthma. These findings highlight the need to manage pollutant sources such as transportation and the heating system in residential areas beyond industrial emissions as the point pollution source. The management policies have to focus on protecting vulnerable populations, such as children and the elderly, by implementing small-sized urban forests to adsorb the PM2.5 within the city and establishing blocking forests to prevent PM10 near the industrial complex.

Data-driven optimisation of process parameters for reducing developed surface area ratio in laser powder bed fusion

Abstract Optimising process parameters is a key category of approaches to improve the surface quality of laser powder bed fusion parts. So far, many optimisation methods have been presented, which provide effective ideas and approaches for improving surface quality. However, these methods all focus on the improvement of $$R_a$$ R a , $$S_a$$ S a , $$R_{sk}$$ R sk , or $$R_{\Delta q}$$ R Δ q . These parameters are sufficient for most applications. They are however not suitable for applications where functional performance is linked with surface area. To quantify the quality of surfaces for these applications, the developed surface area ratio ( $$S_{dr}$$ S dr ) is a more appropriate parameter as it can be used to quantitatively express the exposed functional surface area. In this paper, a data-driven method for optimising five process parameters, namely layer thickness, laser power, hatch spacing, point distance, and exposure time, to reduce the developed surface area ratio of laser powder bed fusion parts is proposed. Firstly, experiments are designed, and actual build and measurement experiments are conducted to acquire a fixed amount of data. A Bayesian ridge regression model for predicting a developed surface area ratio from the five process parameters is then trained and tested and compared with several other machine learning models using the acquired data. After that, optimisation of the five process parameters to reduce developed surface area ratio is carried out using the genetic algorithm, in which the objective function values (developed surface area ratios) are predicted using the established Bayesian ridge regression model. Finally, an additional actual build and measurement experiment is conducted to validate the optimisation. The testing results show that the Bayesian ridge regression model can obtain an average R $$^2$$ 2 score of 0.77 and an average mean absolute error of 8.48 on the testing dataset. The validation results suggest that the developed surface area ratios generated by the optimisation are relatively small, and on average, they are 52.11% smaller than the developed surface area ratio under the process parameters recommended by the used laser powder bed fusion system.

Understanding the effect of galvanic corrosion on the sulfide stress corrosion cracking of X80/Inconel 625 weld overlay

Purpose This study aims to investigate the effect of galvanic corrosion on the sulfide stress corrosion cracking (SSCC) of X80/Inconel 625 weld overlay by altering the cathode/anode area ratios, Na2S2O3 concentrations and temperatures. Design/methodology/approach The effects of galvanic corrosion on X80/Inconel 625 weld overlay SSCC were investigated by immersion test, galvanic corrosion current test, electrochemical measurement, four-point bending experiment, hydrogen permeation experiment and scanning electron microscopy. Findings The anodic dissolution of the fusion boundary was enhanced as the cathode/anode area ratio increased, which is necessary for the SSCC of the X80/Inconel 625 weld overlay. However, severe galvanic corrosion reduced the SSCC susceptibility. The SSCC susceptibility showed a linear increase with Na2S2O3 concentration in the range of 10−4 ∼ 10−2 mol/L. However, further increasing the Na2S2O3 concentration to 10−1 mol/L resulted in the disappearance of SSCC. This is likely because sufficient hydrogen was required for SSCC initiation even under severe anodic dissolution conditions, which was further supported by the reduced SSCC susceptivity at elevated temperatures. Originality/value Limited studies aim to establish the relationship between the galvanic corrosion and SSCC of welded joints through altering the cathode/anode area ratios, Na2S2O3 concentrations and temperatures. This work will pave the way for understanding the effect of galvanic corrosion on the SSCC of dissimilar weld joints.

Residential areas, travel burdens, and children with cancer: Analysis of mobility and mortality ratios using data from Japan's national population-based cancer registry

Objectives Although childhood cancer treatment has recently become centralized at specialized hospitals worldwide, the relationship between mortality ratios and living in rural areas or traveling long distances for treatment remains controversial. In the present study, we examined whether regional differences in patient mobility and mortality ratios exist in Japan.Methods We investigated 10,713 patients with cancer aged ≤18 years, diagnosed between 2016 and 2019, registered in the national cancer registry data. The patients were divided into two categories based on their residence at diagnosis: urban and rural. Urban areas were defined as metropolitan or urban areas according to the 2015 census or as prefectural cities; all other areas were defined as rural. Additionally, we divided the patients into two groups based on the one-way travel time to the treatment hospital (≤1 h or >1 h), as estimated from location information at the community level using route-planner web services. Next, we calculated the percentage of patients who received treatment within their residences in both areas and for each treatment type. We compared the percentage of distant metastasis in all cancers and each diagnosis group between the two areas using the chi-square test. We finally applied Cox proportional hazard models to obtain adjusted mortality hazard ratios for urban versus rural areas and travel times of ≤1 h versus >1 h.Results Overall, 77% of the patients were classified as urban residents. The percentages of patients receiving treatment within their residency, secondary medical care area, prefecture, and regional block levels were 22-46%, 80-87%, and 95-99%, respectively. Only central nervous system tumors (III) showed a significant difference in the percentage of distant metastases, which were more common in urban areas (6% vs. 3%). The adjusted mortality hazard ratios were not significantly different between urban and rural areas for all cancers or each diagnosis group. The travel time comparison yielded significant differences of 1.17 for all cancers and 2.57 for lymphomas (II).Conclusion Approximately 80% of the patients received treatment within their prefecture, although a few traveled long distances across regional blocks. We observed no differences in the mortality ratio between urban and rural areas, although significant differences were found in all cancers and one cancer in the travel burden comparison. These results highlight the need for continued evaluation of the increasing trend in patient travel burden and its impact on survival, as childhood cancer treatment has become centralized in Japan.

The evolution and morphodynamic characteristics of shoals and troughs in Lingdingyang Bay of the Pearl River Estuary

Shoals and troughs are the fundamental geomorphological units of estuarine systems. However, their definition and morphodynamic characteristics, influenced by the complex dynamic environment, remain a critical challenge. This work introduces a depth–area spatial function as a quantitative criterion for the definition of shoals and troughs, while simultaneously elucidating their geodynamic implications. The Lingdingyang Bay (LDB) of the Pearl River Estuary serves as a case study. From 1901 to 2018, the LDB consisted of the West Shoal, Middle Shoal, and East Shoal and the West Trough and East Trough. The threshold depth of the LDB shifted from −5.75 m in 1901 to −4.75 m between 1964 and 2018. The depth–area distribution curve of the LDB exhibits two dominant peak depths (approximately 0 m and −2 m) within the shoal stable state, which categorizes shallow areas into high, medium and low tidal flats. The shoal–trough area ratio in the LDB, relative to the threshold depths, increased from 1901 to 1998, followed by a decline between 2008 and 2018, and culminated in a restoration to the level seen in 1901 (65% shoals and 35% troughs). Regional variations in dominant forces influencing shoal formation and evolution were observed by the vertical classification of the shoal state. The West Shoal is river dominated, the East Shoal is tide dominated, and the Middle Shoal reflects an interaction between riverine inflows and tides. Stabilized curves observed between 2008 and 2018 indicate that this estuary is progressively achieving new equilibrium states. The depth–area spatial function is useful for identifying shoals and troughs within various estuaries, which also provides a geomorphological framework for understanding the estuarine evolution and sediment dynamics.

Effect of Food Intake or Coadministration With an Acid-Reducing Agent on Lenacapavir Pharmacokinetics Following Oral Administration.

Lenacapavir is a potent, long-acting HIV-1 capsid inhibitor used in combination with other antiretrovirals to treat HIV-1 infection. The pharmacokinetics of orally administered drugs may be affected by food intake or coadministration of acid-reducing agents (ARA). Two Phase 1 studies were conducted on healthy participants to evaluate the effect of food and the impact of the histamine H2-receptor antagonist famotidine in parallel cohorts. In Study 1, oral lenacapavir (300mg) was administered under fasting conditions, after a standardized high-fat meal, and after a low-fat meal (n=8/cohort). In Study 2, lenacapavir 300mg was administered alone (n=27) and 2 hours after famotidine (40mg; n=25), each under fasting conditions. For the high-fat meal versus fasted comparison, the percentage geometric least-squares mean (%GLSM) ratios for the lenacapavir area under the curve to infinity (AUCinf) and maximum concentration (Cmax) were 115.2 and 145.2, respectively. For the low-fat meal, the %GLSM ratios for lenacapavir AUCinfand Cmax were 98.6 and 115.8, respectively, versus the fasted state. In the famotidine study, the %GLSM ratio for lenacapavir AUC from time zero to the last quantifiable concentration was 137.4, and for Cmax was 100.6. Based on available clinical safety data, the exposure increases observed in these studies were not expected to be clinically relevant. Overall, these data support the dosing of oral lenacapavir without regard to food intake or coadministration with ARAs.

Study on the Effect of Air Velocity and Duct Area on the Heat Dissipation of Lithium-Ion Batteries

With the growing adoption of lithium-ion batteries, the risk of battery thermal runaway is increasing, so effective temperature regulation for battery systems is essential. The air cooling system for battery thermal management offers advantages such as a simple structure and low cost, making it a promising solution for electric aircraft, electric vehicles, and other applications. In this work, the influence of inlet air velocity, inlet size, and inlet/outlet area ratio on the maximum temperature and maximum temperature difference in the battery pack was simulatively studied. When the inlet air velocity was 4 m/s, inlet size was 73 mm × 25 mm, and inlet/outlet area ratio was 1.25, the heat dissipation effect of battery pack was excellent, and the maximum temperature was 324.8 K. This research offers a crucial foundation for designing and setting the operational parameters of air cooling thermal management systems in lithium-ion battery packs.

Risk factors for new vertebral fractures after percutaneous vertebroplasty or percutaneous kyphoplasty in the treatment of osteoporotic vertebral compression fractures

ObjectThis study aims to conduct a prospective analysis of patients with osteoporotic vertebral compression fractures (OVCF) who underwent percutaneous vertebroplasty (PVP) or percutaneous kyphoplasty (PKP), and further analyze the risk factors for new vertebral fracture following treatment.MethodsA prospective study was conducted from November 2020 to March 2022 at the First Hospital of Longyan City to select patients with OVCF who underwent treatment in the Department of Spinal Surgery. Data collection during the follow-up period focused on various factors that could potentially be associated with new vertebral fractures after PVP/PKP procedures. Patients were divided into two groups based on whether they experienced new vertebral fractures within two years after discharge: the new fracture group (n = 186) and the non-fracture group (n = 64), and statistical analysis was conducted accordingly.ResultsAll cases were followed up for 12 to 24 months, with an average of 14.7 months. Differential analysis revealed that age, diabetes, hemoglobin (HB), total protein (TP), serum albumin (ALB), b-C-terminal telopeptide of type I collage (β-CTX), 25-hydroxyvitamin D (25-OH-D3), number of fractured vertebrae, bone mineral density (BMD), regular exercise after discharge, anti-osteoporosis treatment after discharge, cross-sectional area (CSA), and fatty degeneration ratio (FDR) were associated with new vertebral fractures (all P &amp;lt; 0.05). Multivariate analysis showed that age (OR = 1.519, P = 0.032), diabetes (OR = 3.273, P = 0.048), and FDR (OR = 1.571, P = 0.027) were positively associated with the occurrence of new vertebral fractures, while bone mineral density (OR = 0.108, P = 0.044), 25-OH-D3 (OR = 0.871, P = 0.032), CSA (OR = 0.564, P = 0.009), regular postoperative exercise (OR = 0.259, P = 0.025), and osteoporosis treatment (OR = 0.291, P = 0.045) were negatively associated with the occurrence of new vertebral fractures.ConclusionPatients with osteoporosis fractures who are older, have poor glycemic control, lower bone mineral density, lower levels of 25-OH-D3, weaker paraspinal muscles, and higher fat infiltration are at increased risk of new vertebral fractures after undergoing PKP/PVP. On the other hand, maintaining regular physical activity and adhering to osteoporosis treatment can help prevent new vertebral fractures.

The value of quantitative susceptibility mapping and morphometry in the differential diagnosis of Parkinsonism.

Differentiating Parkinson's Disease (PD) from Atypical Parkinsonism Syndrome (APS), including Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP), is challenging, and there is no gold standard. Integrating quantitative susceptibility mapping (QSM) and morphometry can help differentiate PD from APS and improve the internal diagnosis of APS. In this retrospective study, we enrolled 55 patients with PD, 17 with MSA-parkinsonian type (MSA-P), 15 with MSA-cerebellar type (MSA-C), and 14 with PSP. Thirty-three age-matched healthy subjects served as controls. All subjects underwent QSM imaging and 3D T1WI with manual quantification of regions of interest (ROI) and morphometry. ROIs were selected in the basal ganglia and brainstem nuclei, such as the putamen (Pu), globus pallidus (GP), and red nucleus (RN). Morphometry included magnetic resonance Parkinson's disease index (MRPI), the midbrain area-pons area ratio (M/P), and the ratio of vertical line of the long axis of the midbrain and pons (Ratio). Differential variables between groups were extracted and a binary logistic regression was established to differentiate the differential diagnosis between PD and APS and between diseases within APS. The diagnostic value was assessed using the area under the curve (AUC), sensitivity, and specificity. The combination of Pu and GP performed best when used to distinguish PD from MSA-P, with an AUC of 0.800 (95% CI 0.664-0.936). The AUC was optimal when MRPI and M/P were combined to distinguish PD from MSA-C at 0.823 (95% CI 0.686-0.960). Ratio alone performed best in differentiating PD from PSP, with an AUC of 0.848 (95% CI 0.711-0.985). The AUC for Ratio alone in distinguishing MSA-P from PSP was 0.871 (95% CI 0.738-1.0). The AUC when using only M/P to distinguish MSA-C from PSP was 0.931 (95% CI 0.845-1.0). QSM and morphometry each offer distinct advantages in the differential diagnosis among the aforementioned groups. The combination of QSM and morphometry provided the highest diagnostic value in differentiating PD from APS, highlighting the significance of integrating these two imaging techniques for enhanced diagnostic precision in clinical practice. The best indicators described above showed equally high differential diagnostic values in patients with a disease duration of ≤ 3 years. QSM and morphometry will improve the differential diagnosis between PD and APS, as well as improve the internal diagnosis of APS. PD = Parkinson's Disease; MSA = Multiple System Atrophy; MSA-P = Multiple System Atrophy parkinsonian subtype; MSA-C = Multiple System Atrophy cerebellar subtype; PSP =Progressive Supranuclear Palsy; QSM = quantitative susceptibility mapping; Pu = Putamen; GP = Globus Pallidus; RN = Red Nucleus; MRPI = magnetic resonance parkinsonism index; M/P = midbrain area-pons area ratio; Ratio = the ratio of vertical line of the long axis of the midbrain and pons; AUC =area under the curve.

Charring Properties of Korean Larch Structural Glue-Laminated Timber Beams Based on Cross-Sectional Area Ratios

Charring Properties of Korean Larch Structural Glue-Laminated Timber Beams Based on Cross-Sectional Area Ratios

Ecological Management Zoning Identification by Coupling Blue-Green and Gray Infrastructure Networks: A Case Study of Guizhou Province, China

Ecological management zoning is crucial for maintaining regional ecological security and realizing differentiated urban ecological governance. However, the existing zoning methods are overly focused on ecological functional attributes and fail to adequately consider the impacts of human activities, resulting in an insufficiently rational allocation of resources. Taking Guizhou Province as an example, using multi-source data and spatial analysis tools, this study proposed an ecological management zoning framework based on the coupling analysis of the blue-green infrastructure (BGI) network and gray infrastructure (GI) network. The results indicated that (1) the BGI network in the study area included 179 sources, with a total area of 54,228.80 km2, and 232 corridors. (2) There were 53 sources in the GI network, totaling 709.19 km2, and the corridors of the first, second, and third levels were 11,469.31 km, 6703.54 km, and 5341.30 km, respectively. (3) There were 606 barrier points identified, mainly distributed in the central part of the study area, and the total area of the disturbance zone was 1132.50 km2, which had the largest distribution in Qiandongnan, followed by Qiannan. (4) At the county scale, five ecological management zones were identified in the study area based on four indicators, namely, the source area ratio of BGI network, corridor density of BGI network disturbance zone area ratio, and density of barrier point. Then, we proposed targeted optimizations and restorations for each zone. This study organically linked ecological functional attributes and anthropogenic impacts to identify ecological management zones, which will provide new perspectives on synergies between ecological protection and economic development.

Structural evaluation of selected reinforced concrete buildings within the scope of urban renewal in Izmir province

In this study, 160 reinforced concrete buildings located in Izmir, with different numbers of floors and construction years, within the scope of urban renewal between 2013 and 2018, were examined, and their risk status was determined according to the Principles for Identification of Risky Buildings 2013 (RYTEIE 2013). Reinforced concrete buildings were evaluated in detail considering characteristic properties such as concrete compressive strengths, column longitudinal reinforcement ratios, floor weights, ratio of column sectional areas to floor areas, natural vibration periods, ratio of column axial stresses to existing concrete compressive strength, and failure ratios. The structures examined within the scope of the paper were also grouped into two main categories: before and after 1998. In addition, all these buildings were evaluated in terms of Life Safety (LS) performance level with the linear elastic calculation method given in Specification for Structures to be Built in Disaster Areas 2007 (DBYBHY 2007), which was also in force between 2013 and 2018. It is observed that 72% of reinforced concrete buildings were determined as risky buildings according to RYTEIE 2013 and couldn’t provide the LS performance level according to DBYBHY 2007.

Ultrasonic backscattering model of lamellar duplex phase microstructures in polycrystalline materials.

Carbon steel and low alloy steel are pearlitic heat-resistant steels with a lamellar microstructure. There are good mechanical properties and are widely used in crucial components of high-temperature pressure. However, long-term service in high-temperature environments can easily lead to material degradation, including spheroidization, graphitization, and thermal aging. This study proposes a theoretical model of ultrasonic backscattering with a lamellar structure in pearlite areas. It analyzes the effects of different pearlite area ratios and interlamellar spacing on ultrasonic backscattering signals. A Voronoi diagram is used to constructs a two-dimensional finite element (FE) model of the lamellar structure, and the effects of different pearlite area ratio and interlamellar spacing on the backscattering signals are analyzed to verify the correctness of the theoretical model. By preparing spheroidization samples of various grades, the change values of pearlite area ratio and interlamellar spacing are measured. The backscattering signals of different spheroidization samples are collected through the ultrasonic testing experimental platform, and the root-mean-square (RMS) maximum values of the ultrasonic backscattering are extracted. The observed trend is consistent with the theoretical model, finite element method (FEM), and experimental. Compared with the experimental results, the model results have some errors, but can be used to evaluate the performance degradation of metallic materials with lamellar pearlite structure.

Impact of nozzle pressure ratio and convergent-divergent length on the exit Mach number of supersonic jet

PurposeThe purpose of the study is to find the effect of convergent and divergent section length on the exit flow characteristics. Converging-diverging (CD) nozzle design can be difficult because of the necessity for precise geometry and an understanding of compressible fluid flow dynamics. To obtain the ideal supersonic speeds, it is challenging to make sure that the flow chokes at the throat, where the Mach number approaches one and then expands appropriately in the diverging region. The design needs to take into consideration things like the relationship between the area and Mach number, the impact of various pressure ratios and the flow’s isentropic interactions.Design/methodology/approachAn ideal thrust production is achieved through the effective acceleration of exhaust gases through proper nozzle design. This paper numerically investigates impact of convergent, divergent length and nozzle pressure ratio on the exit Mach Number of CD nozzle supersonic jet. Exit Mach Number 1.6 convergent-divergent nozzle was used. In total, five cases were taken as the length of the both the convergent-divergent sections were modified with 50% of increment and decrement in its base length. At four different NPR, the analysis was carried out in over-expanded, correctly expanded and under-expanded conditions. The NPR used were 2, 3.2, 4 and 5.FindingsFrom the results, it is found that the convergent length linearly affects the exit Mach number, while the divergent length variation is not in order. Both the decreased and increased divergent length reduce the supersonic jet exit Mach number. The subsonic region is not majorly affected by the length. There is no rapid change in the flow properties whether the length is reduced or increased. Maximum of 2% to 3% variation is only noticed. On the contrary, a small change in supersonic region or divergent section makes major modification in the flow.Originality/valueTo achieve the desired Mach number, not only the area of the nozzle but also the length affects it. In terms of divergent angle and area ratio, only most of the studies on nozzle have been focused. This study aims to find the impact of convergent length and divergent length on the exit Mach number. This could be used in a wide range of applications, including laser cutting, thermal spraying, gas turbines for power generation, rocket and jet engines, supersonic wind tunnels and turbo chargers in automotive engineering, because of their capacity to accelerate fluids to supersonic speeds.

Rural-Urban Disparities in State-Level Diabetes Prevalence Among US Adults, 2021.

We assessed state-level disparities in diabetes prevalence among adults in rural and urban areas in the United States. We estimated state-specific diabetes prevalence in rural and urban areas in 41 states with applicable data from the 2021 Behavioral Risk Factor Surveillance System. Rural areas were defined based on the 2013 National Center for Health Statistics Urban-Rural Classification Scheme. We estimated diabetes odds ratios (ORs) in rural versus urban areas in each state by using logistic regressions adjusted for sociodemographic characteristics and obesity status. Analyses were conducted in 2023. In rural areas, diabetes prevalence was 14.3%, ranging from 8.4% in Colorado to 21.3% in North Carolina. In urban areas, the prevalence was 11.2%, ranging from 6.9% in Colorado to 15.5% in West Virginia. Unadjusted diabetes ORs in rural versus urban areas were significant (P < .05) and greater than 1 for 19 states. After adjusting for age, sex, race, and ethnicity, the ORs were significant and greater than 1 for 7 states (Florida, Illinois, Kentucky, Maryland, North Carolina, Oregon, and Virginia). With additional adjustment for education, income, and obesity status, diabetes ORs in rural versus urban areas remained significant and greater than 1 for 2 states (North Carolina and Oregon). Our findings reveal significant geographic disparities in diabetes prevalence between rural and urban areas in 19 states. The differences in most states may have been explained by rural-urban differences in sociodemographic characteristics and obesity rates. Our findings could inform decision makers to identify effective ways to reduce rural-urban disparities within states.