The aim of this study was to evaluate the associations between chronic smoking and insulin resistance and beta-cell function in Chinese men without diabetes. A total of 1,568 participants were ...recruited by multistage sampling. Using homeostatic model assessment (HOMA), geometric means of insulin resistance (HOMA-IR) and beta-cell function (HOMA-beta) with 95% confidence interval (CI) were calculated by general linear model. Odds ratios (ORs) with 95% CI were estimated to evaluate the associations between smoking status and insulin resistance and beta-cell deficiency under a logistic regression model. Current smokers had higher levels of 2h glucose (6.66 versus 6.48 mmol/L) for oral glucose tolerance test and lower levels of fasting insulin (5.68 versus 6.03 mU/L) than never smokers. The adjusted means for HOMA-beta (%) were 54.86 in current smokers and 58.81 in never smokers (P = 0.0257). Current smoking was associated with beta-cell deficiency (OR 1.29,95% CI 1.01-1.64) compared to never smoking. The beta-cell function gradually decreased with increasing smoking intensity (P.sub.trend = 0.0026), and the differences were statistically significant when the pack-year of smoking was 20 or above. No association was observed between smoking status and HOMA-IR. Our study suggested that chronic smoking may dose-dependently suppress insulin secretion in Chinese men.
Testing of asphalt concrete samples was conducted by using the asphalt pavement analyzer test, the SuperpaveRG shear tester (SST) frequency sweep test, and the SST repeat shear at constant height ...test to determine the rutting susceptibility that might be expected from samples that have different levels of segregation. Previous research had divided segregation into four levels: none, light, medium, and high. Test results suggest that samples with different segregation levels might show similar rutting susceptibility. Therefore, performance-related models were established in which segregation was divided into three levels: good, fair, and unacceptable. The performance-related models were applied to field data, and examination indicates that the modified models are capable of assessing segregation in field projects. Examination also found that fine segregation was present. Fine segregation can be predicted by extrapolating the developed model from the coarse part to the fine part. However, more data should be investigated to develop acceptable criteria for fine segregation. A methodology was developed to improve pavement quality by controlling aggregate segregation and poor compaction in placed mats. With the models and the proposed methodology, realistic construction uniformity could be assessed by agencies and contractors, which is the first step in obtaining pavements with high performance and longer service life.
Testing of asphalt concrete samples was conducted by using the asphalt pavement analyzer test, the Superpave® shear tester (SST) frequency sweep test, and the SST repeat shear at constant height test ...to determine the rutting susceptibility that might be expected from samples that have different levels of segregation. Previous research had divided segregation into four levels: none, light, medium, and high. Test results suggest that samples with different segregation levels might show similar rutting susceptibility. Therefore, performance-related models were established in which segregation was divided into three levels: good, fair, and unacceptable. The performance-related models were applied to field data, and examination indicates that the modified models are capable of assessing segregation in field projects. Examination also found that fine segregation was present. Fine segregation can be predicted by extrapolating the developed model from the coarse part to the fine part. However, more data should be investigated to develop acceptable criteria for fine segregation. A methodology was developed to improve pavement quality by controlling aggregate segregation and poor compaction in placed mats. With the models and the proposed methodology, realistic construction uniformity could be assessed by agencies and contractors, which is the first step in obtaining pavements with high performance and longer service life.
To study vertical sag requirements and factors affecting the stretched wire alignment method, the vertical sag equation is first derived theoretically. Subsequently, the influencing factors,such as ...the hanging weight or tension, span length, temperature change, elastic deformation, and the Earths rotation, of the vertical sag are summarized, and their validity is verified through actual measurements. Finally, the essential factors affecting vertical sag, the specific strength and length, are discussed. It is believed that the vertical sag of a stretched wire is proportional to the square of the length and inversely proportional to the specific strength of the material.
Non-uniformity is a serious problem in hot-mix asphalt pavements. Minimizing non-uniformity is essential to improve pavement performance and reduce maintenance and rehabilitation cost. However, ...standard quality control/quality assurance procedures which randomly define sampling locations have a low probability of capturing non-uniformity of the in-placed asphalt mixture. This research seeks to develop a technique to quantify non-uniformity in HMA pavements. Multivariate statistical technologies were adopted to develop models for aggregate segregation, the main type of non-uniformity. Segregation was simulated in the laboratory; performance of the simulated specimens was evaluated with the Asphalt Pavement Analyzer test, the Repeated Shear at Constant Height test, and the Frequency Sweep at Constant Height test. Analysis of the test results indicated that segregation could be classified into three levels. New models with segregation levels, good, fair, and unacceptable, were established for aggregate segregation. Based on laboratory and field investigation, a methodology to assess non-uniformity is proposed. In this method, density variations are measured across a pavement in real time. Non-uniformity was evaluated by combining non-destructive density measurements and destructive core analysis. It is recommended that agencies and contractors consider implementing the initial methodology in their construction practices to promote uniformly placed, non-segregated pavements.
Beam energy is a key property to determine the accelerator performance. A real-time and non-destructive method should be used for the energy measurement. In this paper, an energy measurement system ...based on Experimental physics and industrial control systems (EIPCS) is designed and developed for a proton LINAC. The original signals are from beam position monitor, which give us the beam phase information through its electronics. An algorithm from beam energy to phase is deduced. Based on EPICS, the client completes the data acquisition, the IOC achieves beam energy measurement algorithms, and last a whole energy measurement OPI performed by CSS.
Laser fusion brazing welding was proposed.Galvanized steel/AA6061 lapped joint was obtained by laser fusion brazing welding technique using the laser-induced aluminium molten pool spreading and ...wetting the solid steel surface.Wide joint interface was formed using the rectangular laser beam coupled with the synchronous powder feeding.The result showed that the tiny structure with the composition of a-Al and Al–Si eutectic was formed in the weld close to the Al side.And close to the steel side,a layer of compact Fe–Al–Si intermetallics,including the Al-rich FeAl3,Fe2Al5 phases and Al–Fe–Si s1 phase,was generated with the thickness of about 10–20 lm.Transverse tensile shows the brittlefractured characteristic along to the seam/steel interface with the maximum yield strength of 152.5 MPa due to the existence of hardening phases s1 and Al–Fe intermetallics.
Conventionally, high dynamic-range （HDR） imaging is based on taking two or more pictures of the same scene with different exposure. However, due to a high-speed relative motion between the camera and ...the scene, it is hard for this technique to be applied to push-broom remote sensing cameras. For the sake of HDR imaging in push-broom remote sensing applications, the present paper proposes an innovative method which can generate HDR images without redundant image sensors or optical components. Specifically, this paper adopts an area array CMOS （complementary metal oxide semiconductor） with the digital domain time-delay-integration （DTDI） technology for imaging, instead of adopting more than one row of image sensors, thereby taking more than one picture with different exposure. And then a new HDR image by fusing two original images with a simple algorithm can be achieved. By conducting the experiment, the dynamic range （DR） of the image increases by 26.02dB. The proposed method is proved to be effective and has potential in other imaging applications where there is a relative motion between the cameras and scenes.
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