The Development of Biomimetic Spherical Hydroxyapatite/Polyamide 66 Biocomposites as Bone Repair Materials

A novel biomedical material composed of spherical hydroxyapatite (s-HA) and polyamide 66 (PA) biocomposite (s-HA/PA) was prepared, and its composition, mechanical properties, and cytocompatibility were characterized and evaluated. The results showed that HA distributed uniformly in the s-HA/PA matrix. Strong molecule interactions and chemical bonds were presented between the s-HA and PA in the composites confirmed by IR and XRD. The composite had excellent compressive strength in the range between 95 and 132 MPa, close to that of natural bone. In vitro experiments showed the s-HA/PA composite could improve cell growth, proliferation, and differentiation. Therefore, the developed s-HA/PA composites in this study might be used for tissue engineering and bone repair

Prediction Of Single Proppant Terminal Settling Velocity In High Viscosity Friction Reducers By Using Artificial Neural Networks And XGBoost

High viscosity friction reducers (HVFRs) have been recently gaining more attention and increasing in use, not only as friction-reducing agents but also as proppant carriers. The settling velocity of the proppant is one of the key outputs to describe their proppant transport capability. However, it is influenced by many factors such as fluid properties, proppant properties, and fracture properties. Many empirical/physics-based models and correlations to predict particle settling velocity have been developed. However, they are usually based on certain assumptions and have applicable limits. In contrast, machine learning models can be considered as a black box. The objective of this study is to use machine learning models to find the relationship between the multiple factors mentioned above and particle settling velocity in order to correctly predict it. Two of the most popular and powerful machine learning algorithms, Artificial neural networks (ANN) and XGBoost, were comparatively investigated with standard data processing and training procedures. Mean Absolute Errors (MAEs) for ANNs and XGBoost were 0.010379 and 0.004253 respectively. The XGBoost learning algorithm had overall better prediction performance than the ANN model in terms of the data sets used for this study and had the potential to properly handle missing values by itself

Flame image segmentation using multiscale color and wavelet-based texture features

Accurate and reliable segmentation of flame images are crucial in vision based monitoring and characterization of flames. It is, however, difficult to maintain the segmentation accuracy while achieving fast processing time due to the impact of the background noise in the images and the variation of operation conditions. To improve the quality of the image segmentation, a flame image segmentation method is proposed based on Multiscale Color and Wavelet-based Textures?MCWT? of the images. By combining the color and texture features, a characteristic matrix is built and then compressed using a local mean method. The outer contour of the flame image under the compressed scale is detected by a cluster technique. Subsequently, the flame edge region under the original scale is determined, following that, the characteristic matrix of the edge region is constructed and classified, and finally, the flame image segmentation is achieved. Flame images captured from an industrial-scale coal-firedtest rig under different operation conditions are segmented to evaluate the proposed method. The test results demonstrate that the performance of segmenting flame images of the proposed method is superior to other traditional methods. It also has been found that the proposed method performs more effectively in segmenting the flame images with Gaussian and pepper and salt noise

Fractal Characteristics of Thin Thermal Mixing Layers in Coal-Fired Flame

The images of turbulent flame were acquired by using a digital imaging system on an industry-scale pulverized coal-fired test rig?The fractal dimensions of thin thermal mixing layers in flame were computed through morphology-based flame image processing techniques?The effects of the ratios of primary air and secondary/tertiary air on fractal dimensions were characterized?The results presented in this work show that the variations of fractal dimension are closely related to the ratio changes of primary air and secondary/tertiary air. Therefore?the fractal dimensions of flame thin thermal mixing layers can be used as an important indicator for the control and optimization of a combustion process

Measurement of Coal Particle Combustion Behaviors in A Drop Tube Furnace Through High-speed Imaging and Image Processing

This paper presents the measurement and characterization of single coal particles in a drop tube furnace through high speed imaging and image processing. A high speed camera coupling with a long distance microscope is employed to acquire the images of the particle during its residence time in the furnace. A set of physical quantities of the particle, including size, shape and boundary roughness, are defined and computed based on the images obtained, which are then used describe the combustion behaviors of the particle. Experimental results show that the combined high speed imaging and image processing technique has provided an effective means for measuring and quantifying the characteristics of single coal particles during combustion

Ten-year changes in the prevalence of overweight, obesity and central obesity among the Chinese adults in urban Shanghai, 1998–2007 — comparison of two cross-sectional surveys

BACKGROUND: In China, obesity is expected to increase rapidly in both urban and rural areas. However, there have been no comprehensive reports on secular trends in obesity prevalence among Chinese adults in urban Shanghai, which is the largest city in southern China. METHODS: In 1998–2001 and again in 2007–2008, two independent population-based cross-sectional surveys were conducted in Shanghai to investigate the prevalence of metabolic disorders. These surveys obtained height, waist circumference (WC), and weight measurements for Chinese adults aged between 20 and 74 years who lived in urban communities. From the 1998–2001 survey, 4,894 participants (2,081 men and 2,813 women, mean age: 48.9 years) were recruited, and 4,395 participants (1,599 men and 2,796 women, mean age: 49.8 years) were recruited from the 2007–2008 survey. Using the World Health Organization criteria, overweight was defined as 25 kg/m(2) ≤ BMI < 30 kg/m(2) and obesity as BMI ≥ 30 kg/m(2). Central obesity was defined as WC ≥ 90 cm in men or ≥85 cm in women. The differences in prevalence of obesity, central obesity and overweight between the two surveys were tested using multivariable logistic regression analyses. RESULTS: Compared to the 1998–2001 survey, in the 2007–2008 survey the BMI distribution for men and the WC distribution for both genders is shifted significantly to the right along the x-axis (all p < 0.001). Over the ten years, the prevalence of combined overweight and obesity increased 24% (from 31.5% to 39.1%, p < 0.001) in men, but decreased 8% (from 27.3% to 25.0%; p < 0.01) in women. The prevalence of central obesity increased 40% in men (from 19.5% to 27.3%; p < 0.01), but the increase was not significant in women (15.0% to 17.1%; p = 0.051). In the total population, only central obesity showed a significant change between the populations in the two surveys, increasing 29% (from 17.3% to 22.4%; p < 0.001). CONCLUSIONS: Over this 10 year period, central obesity increased significantly in the Shanghai adult population. However, the prevalence of combined overweight and obesity was significantly increased in men but not in women

Evaluation of the Ecological Quality of the Taishan Region Based on Landsat Series of Satellite Images

The deterioration of ecological environment has seriously restricted regional sustainable development. Taishan region is one of the ecological protection and restoration of life community of mountains-rivers-forests-farmlands-lakes-grasslands in China. Its ecological quality changes are directly related to the overall layout of ecological restoration and protection projects. In this study, the Taishan region of China was taken as study area, and the grade change, spatial distribution, and spatial temporal fluctuation of the ecological environment quality were quantified. Based on the ENVI platform, the Landsat series of three images of the Taishan region in 2005, 2013, and 2017 serve as the data source, and the remote sensing ecological index model (RSEI) was used. According to the change characteristics of land use types, the driving factors of ecological environmental quality change were analyzed. The results showed that: (1) The area ratio of the ecological environment quality above the middle level was in order from large to small: 2005 (97.37%) > 2017 (91.46%) > 2013 (84.64%). (2) The overall quality of the ecological environment declined during the period of 2005-2013. (3) The overall change ranges from 2013 to 2017 are smaller than those from 2005 to 2013. The area of the deteriorating area decreased by 44.90%, and the area of the constant area and the area of the area that improved increased by 16.17% and 28.72%, respectively. During 2013-2017, the general trend is getting better and better. The improved areas were mainly concentrated in the main urban areas (Taishan District, Daiyue District), eastern Ningyang County, and western Xintai City. The research results can provide a scientific basis for the scientific evaluation of the ecological environment quality during the development and construction of the region, and have important value in the design and application of the ecological environment quality optimization path

Effect of adjunctive ranitidine for antipsychotic-induced weight gain: A systematic review of randomized placebo-controlled trials

This study was a meta-analysis of randomized controlled trials (RCTs) of ranitidine as an adjunct for antipsychotic-induced weight gain in patients with schizophrenia. RCTs reporting weight gain or metabolic side effects in patients with schizophrenia were included. Case reports/series, nonrandomized or observational studies, reviews, and meta-analyses were excluded. The primary outcome measures were body mass index (BMI) (kg/m2) and body weight (kg). Four RCTs with five study arms were identified and analyzed. Compared with the control group, adjunctive ranitidine was associated with marginally significant reductions in BMI and body weight. After removing an outlier study for BMI, the effect of ranitidine remained significant. Adjunctive ranitidine outperformed the placebo in the negative symptom score of the Positive and Negative Syndrome Scale. Although ranitidine was associated with less frequent drowsiness, other adverse events were similar between the two groups. Adjunctive ranitidine appears to be an effective an