324 research outputs found
EffectĀ ofĀ CeramicĀ PropertiesĀ andĀ Depth-of-penetration TestĀ ParametersĀ onĀ theĀ Ballistic PerformanceĀ ofĀ Armour CeramicsĀ
Through an analysis on the relationship among ceramic properties, the depth of penetration (DOP) test parameters and the ballistic performance of armour ceramics based on literatures, the effects of ceramic type, tile thickness and projectile velocity on the ballistic performance of different kinds of ceramics were investigated systematically. The results show that the ballistic performance of different armour ceramics mainly depends on its density, and by using thin ceramic tiles or under high velocity impact, the ceramic composite armour could not provide effective ballistic protection. Furthermore, the differences in the ballistic performance of armour ceramic are found due to the different ballistic performance criteria and DOP test conditions. Additionally, the slope of the depth of penetration (not include tile thickness) (Pa) versus tile thickness has negative correlation with flexural strength of ceramics, indicating the flexural strength can be one of the criteria to evaluate the performance of armour ceramics
"LIVING HIGH-TRAINING LOW" ALTITUDE TRAINING ON IMPROVEMENT OF SEA LEVEL HEMOGLOBIN/HEMATOCRIC IN MALE AND FEMALE ELITE SWIMMERS
This study investigated the effect of "living high-training low" altitude on improvement of sea level hemoglobin and hematocric in male and female elite swimmers. A total of ten elite swimmers at the international and national level was recruited and randomly divided into two groups, altitude training group and control group. The athletes in altitude training group lived high condition while training at sea level for three weeks. The altitude was set at 2,800m. The all subjects in both groups accepted same training in the intensity, frequency and duration. Hemoglobin and hematocric were measured at sea level on seven occasions, the day before starting the experiment, during the period of experiment and the day completing the experiment. The results showed that the hemoglobin and hematocric in altitude training group increased 8.6% and had significant difference compared with those before the experiment. While the level of hemoglobin and hematocric in control group did not show any obvious change. "Living high-training low" altitude training can significantly improve the level of hemoglobin and hematocric
Development of an UAS for Earthquake Emergency Response and Its Application in Two Disastrous Earthquakes
To support humanitarian action after a disaster, we require reliable data like high-resolution satellite images for analyses aimed to define the damages of facilities and/or infrastructures. However, we cannot obtain satellite images in few days after an event. Thus, in situ surveys are preferred. Advances in unmanned aircraft system (UAS) have promoted them to become precious tools for capturing and assessing the extents and volume of damages. Safety, flexibility, low cost, and ease of operation make UAS suitable for disaster assessment. In this chapter, we developed an example of UAS for swiftly acquiring disaster information. With the selected fixed-wing UAS, we successfully performed data acquisition at specified scales. For the image analysis, we applied a photogrammetric workflow to deal with the very high resolution of the images obtained without ground control points. The results obtained from two destructive earthquakes demonstrated that the presented system plays a key role on the processes of investigating and gathering information about a disaster in the earthquake epicentral areas, like road detection, structural damage survey, secondary disaster investigation, and quick disaster assessment. It can effectively provide disaster information in hardly entered areas to salvation headquarters for rapidly developing the relief measures
Multi-band remote sensing based retrieval model and 3D analysis of water depth in Hulun Lake, China
Hulun Lake, a large lake located on the cold and arid Hulunbeir grassland in the Inner
Mongolia Autonomous Region, is the fifth largest in China and the largest in the north of
the country. However, the information on the lakeās characteristics (e.g., water depth versus
surface area) is scarce in literature. Based on the lakeās physiographic features, this study
developed and used a model that merges the sunlight reflection band with the thermal
infrared radiation band to simulate the lakeās characteristics. The model verification and
error analysis indicated an optimal model structure of logarithm. Thus, this logarithmic
model was selected to analyze the spectral data. The results indicated that the model did a
good job in reproducing observed water depths and accurately predicted the depths on 24
September 2007. This showed that this model can be reliably applied to the cold and arid
region. Subsequently, the results were used to generate a triangular irregular network (TIN)
model, which in turn was used to compute the functional relations between water level,
surface area, and volume. The correlation between water level and volume is superior to
that between water level and area. The regression equation developed in this study can be
used to estimate the volume when water elevation is knowninfo:eu-repo/semantics/publishedVersio
Disease Burden of Chronic Kidney Disease Due to Hypertension From 1990 to 2019: A Global Analysis
Background: Although it is widely known that hypertension is an important cause of chronic kidney disease (CKD), little detailed quantitative research exists on the burden of CKD due to hypertension.Objective: The objective of the study is to estimate the global disease burden of CKD due to hypertension and to evaluate the association between the socioeconomic factors and country-level disease burden of CKD due to hypertension.Methods: We extracted the disability-adjusted life-year (DALY) numbers, rates, and age-standardized rates of CKD due to hypertension from the Global Burden of Disease Study 2019 database to investigate the time trends of the burden of CKD due to hypertension from 1990 to 2019. Stepwise multiple linear regression analysis was performed to evaluate the correlations between the age-standardized DALY rate and socioeconomic factors and other related factors obtained from open databases.Results: Globally, from 1990 to 2019, DALY numbers caused by CKD due to hypertension increased by 125.2% [95% confidential interval (CI), 124.6 to 125.7%]. The DALY rate increased by 55.7% (55.3 to 56.0%) to 128.8 (110.9 to 149.2) per 100,000 population, while the age-standardized DALYs per 100,000 population increased by 10.9% (10.3 to 11.5%). In general, males and elderly people tended to have a higher disease burden. The distribution disparity in the burden of CKD due to hypertension varies greatly among countries. In the stepwise multiple linear regression model, inequality-adjusted human development index (IHDI) [Ī² = ā161.1 (95% CI ā238.1 to ā84.2), P < 0.001] and number of physicians per 10,000 people [Ī² = ā2.91 (95% CI ā4.02 to ā1.80), P < 0.001] were significantly negatively correlated with age-standardized DALY rate when adjusted for IHDI, health access and quality (HAQ), number of physicians per 10,000 people, and population with at least some secondary education.Conclusion: Improving the average achievements and equality of distribution in health, education, and income, as well as increasing the number of physicians per 10,000 people could help to reduce the burden of CKD due to hypertension. These findings may provide relevant information toward efforts to optimize health policies aimed at reducing the burden of CKD due to hypertension
Recommended from our members
Study of the corrosion rate behavior of ion implanted Fe-based alloys
We report on some studies we have made of the time evolution of the corrosion behavior of ion implanted samples of pure iron, medium carbon steel, and 18-8 Cr-Ni stainless steel. Ti, Cr, Ni, Cu, Mo and Yb were implanted at mean ion energies near 100 keV and at doses up to 1 {times} 10{sup 17} cm{sup {minus}2} using a Mevva metal ion implantation facility. A novel feature of this experiment was the simultaneous implantation with several different implanted species. The implanted samples were immersed in sulfuric acid solution at 40{degrees}C and the corrosion monitored as a function of time. The loss in mass was accurately measured using atomic absorption spectroscopy. The functional dependence of the corrosion behavior was established for all samples. The cumulative mass loss Q is given as a function of time t by Q = At{sup N}, where A and N are parameters; thus the corrosion rate V is given by V = ANt{sup N-1}. A is dominated by the initial mass loss and N reflects the long-time corrosion behavior. The values of the parameters A and N were obtained by a least-squares regression for all the samples investigated. We determined that for the samples investigated here, N > 1 always and V increases with time throughout the experimental duration. In this paper we summarize the experimental results and discuss the effect of A and N on corrosion rate and the relationship between the corrosion current density and the parameters A and N. 11 refs., 4 figs
- ā¦