bluuebunny/crossref_metadata_2025 huggingface dataset:
Influences of Laser Remelting on Microstructure and Thermal Shock Resistance of Al2O3-13wt.%TiO2 Coatings Deposited by Plasma Spraying
Authors: Wang Dongsheng
Published: August 2019

Al2O3-13wt.%TiO2 composite ceramic coatings were prepared by plasma spraying and laser remelting. Morphology, microstructure and phase composition were analyzed by scanning electron microscope (SEM) and X-ray diffractometer (XRD). Meanwhile, effects of laser remelting on thermal shock resistance of plasma-sprayed coatings were investigated and the thermal shock failure mechanism of coatings were discussed. Results demonstrate that after laser remelting, particles on the ceramic coating are refined and the lamellar structure disappears, thus increasing density and getting a remelting coating basically without defects like cracks. Laser remelting metastable phase γ-Al2O3 is transformed into a stable phase α-Al2O3. Due to low heat conductivity coefficient of ceramic materials, it is impossible to remelt the whole ceramic coating at laser remelting. An isometric crystal remelted zone with small grains, a sintered zone and a lamellar remained plasma-sprayed zone are formed on the remelting ceramic coating. Compared with plasma-sprayed coating, the laser-remelted coating has better thermal shock resistance. The thermal shock failure form of ceramic coating deposited by plasma spraying is basically corner peeling, while the thermal shock failure forms of laser-remelted ceramic coating includes both corner peeling and considerable local peelings in the center. Influences of laser remelting on thermal shock resistance of coating are mainly manifested as reduced initial failure resistance of coatings, decelerated crack propagation on coatings and changing failure mode of coatings.
Toughening Study of Epoxy Structural Reinforcement Adhesive in Concrete at Room Temperature
Authors: Liu Lin , Chen Yiyi
Published: August 2019

This paper selects liquid bisphenol A epoxy resin with different types of room temperature curing agent and different types of room temperature toughener. Comparing the energy per unit area combined with the tensile test, bending strength, compressive strength and steel-steel tensile shear strength, combination of the 10% amount of A2364 toughener and polyamide A350A curing agent shows best performance in various tests. Its bending strength is 96.9 MPa, shear strength is 23.2 MPa, and Tg is 74.6 °C. The characteristic temperature of the epoxy strengthening system is calculated through DSC. The average apparent activation energy E = 63.79J/mol and the reaction order number n=0.93. The kinetic equation of the toughened epoxy curing system is obtained, which provided theoretical support for practical application.
Application of Hyperelastic Materials in a Composite Hollow Brick for Assessing the Reduction of Dynamic Loads - Numerical Analysis
Authors: Major I , Major M
Published: August 2019

The article addresses the use of hyperelastic materials to evaluate the redistribution of stresses in a composite structural hollow brick by means of numerical analysis. Both rubber and concrete were modelled as hyperelastic materials with appropriate energy potential. The concrete was modelled on the Murnaghan potential, while the rubber was modelled on the Zahorski potential. The analysed prefabricated hollow brick was loaded with a force impulse. As a result, redistribution of effective stress was observed, which was important for the evaluation of the operation of the analysed prefabricated product. The presented numerical analysis was carried out using the ADINA program.
Fabrication of Super-hydrophobic Surfaces and Studies of Water Flow in Super-hydrophobic Micro-tubes
Authors: Yu Zhijia , Liu Xinghua , Huo Subin , Song Shanpeng , Wang Baohe , Kuang Guozhu
Published: August 2019

Hierarchical alveolate structures of micro-nano scale were prepared on stainless steel substrates with chemical etching. Fine papillae stand on protuberances are found. After fluorination treatments, the surfaces exhibit super-hydrophobic properties, with water contact angles of 163°. Stainless-steel micro-tubes with super-hydrophilic and super-hydrophobic surface were fabricated with chemical etching and chemical etching-fluorination treatment respectively. The effect of surface wettability on the fluid flow in micro-tubes was investigated with water as the working fluid. The experimental setup was designed in such a way that the investigation of the pressure drop and friction factor was possible. It is found that friction factor in super-hydrophilic micro-tube is in good agreement with Hagen-Poiseuille theory at low Reynolds number (Re<600), while higher than classical values at higher Reynolds number. The pressure drop of water flowing in super-hydrophobic micro-tube decreases compared with that in super-hydrophilic micro-tube, with the maximal decrease of 39%, which indicates the prospective utilization in process industry.
Preparation and Study of High Reflectance Color Solar Heat-reflective Insulation Coatings
Authors: Lu Guozhong , He Jintai , Zhang Jiayang , Wang Haiwang , Zhang Yajing
Published: August 2019

Based on the existing preparation process of common thermal insulation coatings, a kind of high reflectance color solar heat-reflective insulation coatings was developed by improving the thermal insulation coatings. The effects of hollow glass beads, titanium dioxide and other factors on the properties of the coatings were discussed, and the thermal insulation properties of the coatings were characterized by solar reflectance ratio. The results show that the water-based color solar heat-reflective insulation coatings with high solar reflectance, high weathering resistance and high stain resistance can be prepared by using pure acrylic emulsion and silicone acrylic emulsion as the film-forming base material, using the rutile type titanium dioxide, calcined kaolin, precipitated barium sulphate and hollow glass beads as the insulated function pigments and fillers, and using the auxiliaries for coatings.
Flame Retardancy of Thermoplastic Polyurethane Using Phosphorus-containing Flame Retardants
Authors: Yu Guomin , Song Meng , Jiao Shuyan , Jia Xu , Li Yinghua
Published: August 2019

A new phosphorus-containing polymer was synthesized and applied as a flame retardant in the polyether thermoplastic polyurethane (TPU). This flame retardant combined with two commercial flame retardants of melamine pyrophosphate (MPP) and melamine cyanurate (MCA) were also used in TPU. Their flame retardancy, thermal degradation and structural feature were investigated by limiting oxygen index (LOI), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The experimental data showed that the presence of phosphorus-containing flame retardant improve the limiting oxygen index, thermal stability and fire behavior. The LOI value of TPU including 20 wt% synthesized phosphorus-containing flame retardant and 20 wt% MCA was increased to 25.8. The thermal stability of TPU was also excellently improved comparing with the neat TPU. A maximum char residue was obtained when 20 wt% synthetic flame retardant and 20 wt% MPP were added into the TPU which the char yields were 18.7%. The combustion heat results showed that the value of neat TPU is highest than other TPUs by adding the different flame retardants. The SEM results showed that a dense char layer was obtained by adding the synthetic phosphorus-containing flame retardant and MCA with 20 wt % respectively into the TPU system.
Preparation and Photocatalytic Activity of BiOBr with High Exposure {102} Crystalline Surface
Authors: Yuan Chunhua , Bao Hongling , Ren Yongqing
Published: August 2019

Flake BiOBr was prepared by one-step hydrothermal method using NaBr and Bi(NO3)3•5H2O as raw materials. The structure of the samples was characterized by means of XRD, SEM, UV-VIS. The photocatalytic activity of BiOBr was studied with methylene blue as probe. The results show that BiOBr with high exposure {102} can be obtained when the hydrothermal temperature of the product is 160°C and the hydrothermal time is 24 h. Under visible light, the degradation rate of methylene blue was over 98%. When the catalyst was reused three times, the degradation rate could still reach 80%.
Study on Increasing Vulcanization Rate of Ethylene-propylene Rubber
Authors: Zhou Kun
Published: August 2019

The effects of several commonly used an ultra on the vulcanization properties of EPDM vulcanized with sulfur and the vulcanization properties and physical properties of EPDM vulcanized with peroxide were studied. The results showed that BZ and lseg-4 vulcanization rate was fast and frost spraying was not easy. Peroxide tx29-40 can be used to vulcanize EPDM. The activation energy and vulcanization speed of tx29-40 are higher than DCP/TAIC and double 2,5 which can be used for high temperature and rapid vulcanization of peroxide in EPDM.
Construction of the Photonic Crystal Structural Colors with High Colorfastness Using the Novel Synthesis Adhesive
Authors: Zheng Hongliang , Liu Xinhua , Fang Yinchun , Ding Jiang
Published: August 2019

Phtoonic crystal Structural color has received more and more attentions in recent years. However, there are also some drawbacks of these structural colors, such as the cracking and low colorfastness. In this research, the novel adhesive of P(GMA-co-HFBMA)-g-PEGMA which contians the epoxy group and the hydrophobic fluorocarbon chain was synthesized. The chemical sturcture of the P(GMA-co-HFBMA)-g-PEGMA was charactrized by FTIR and EDS spectra. The results of FTIR and EDS spectra revealed that P(GMA-co-HFBMA)-g-PEGMA was successfully synthesized and used as the adhesive for the improvment of the colorfastness. The results revealed that the novel adhesive will be beneficial for the improvement of the rubbing and washing colorfastness of the photonic crystal structural colors. When the usage of 1% P(GMA-co-HFBMA)-g-PEGMA was 0.5 mL, the brightness of the structrual color will incease. While the usage was higher than the 1 mL, the brightness of the structural colors will decrease with the increasing of the usage. Therefore, the the suitable usage of the 1% P(GMA-co-HFBMA)-g-PEGMA was less than 1 mL. This research will provide the novel method for the development of the photonic crystal structural color with high colorfastness.
Analysis on Emergency Management of Coal Mine Safety Production in China
Authors: Cheng Genyin , Zhang Changchang
Published: August 2019

The working environment of coal mines is special and there are many dangerous sources, resulting in frequent accidents. As the demand for coal in the society increases, the depth of coal mining continues to deepen, and deep mining faces more security problems. This paper analyzes the relevant literatures of coal mine emergency management in recent years, clarifies the current situation of emergency management in China’s coal mines, points out the problems existing in China’s coal mine emergency management and suggestions for improving the overall level of coal mine emergency management, and provides reference for promoting the better development of coal mine safety production in China. Prevent more emergencies, reduce casualties and financial losses, and realize the transition from high-risk industries to the security industry at an early date.
Improvement of Mechanical Strength, Thermal Stability, Swelling, Moisture Content of Triple Network Hydrogels by Carbon Nanotubes
Authors: Jiang Bing , Li Qingshan , Hong Wei , Wu Shu , Yan Dawei , Gao Le
Published: August 2019

In this study, we prepared a novel carbon nanotubes reinforced three network hydrogels composed of carbon nanotubes, polyacrylic acid(PAA), agar and polyvinyl alcohol(PVA), consisting of an agar gel as the first physical network, a PAA-Fe3+ gel as the second physical network and a polyvinyl alcohol as the third physical network. The surface modification of MWCNTs was carried out by oxyfluorination to introduce the functional groups on the hydrophobic MWCNTs. Agar/PAA-Fe3+/PVA/MWCNTs hydrogels with high tensile and compression strength(σf of 1.5 Mpa, Ɛf of 14.24 mm/mm) and (σf of 1.69 Mpa, the deformation of 80%), thermal stability, low-swelling, high moisture content properties were successfully prepared by a simple three-step method. The addition of carbon nanotubes has significantly improved the thermal stability of the gels, its thermogravimetric curve drops obviously until 387°C. Under the joint action of hydrogen bonding and ion coordination interaction, the gel achieves a perfect balance of swelling and moisture content. The research provide a new method to improve mechanical, swelling, thermal stability, moisture content ability by adjusting the compositions and interactions in the gels.
Study on the Biocompatibility of Mg-4.0Zn-1.0Sr-0.4Ca Alloy with Phosphating Treatment after Implantation in Rats
Authors: Cui Tong , Liu Yan , Chen Suiyuan , Qin Haiming , Song Fulin
Published: August 2019

The phosphating treatment coating is prepared on Mg-4.0Zn-1.0Sr-0.4Ca alloy surface, and the phosphating coating is consisted with HA and a small amount of calcium hydrogen phosphate hydrate. The hemolysis rate of both phosphated coating and uncoated samples is less than 5 %, showing that both have good hemolytic resistance which meet the requirements of use. It is found through the pathological studies that after implantation Mg-4.0Zn-1.0Sr-0.4Ca alloy for 30 days, for the leg muscle tissue, kidney tissue, liver tissue and bone tissues of rat the inflammation phenomenon is gradually recovered or completely recovered being passed the corrosion peak, while for the rat implanted the phosphating treatment alloy was in the acute stage of inflammation. After implantation Mg-4.0Zn-1.0Sr-0.4Ca alloy and the phosphating treatment alloy for 30 days, all of the brain tissue, myocardial tissue, lung tissue, intestinal tissue are unaffected.
Empirical Econometric Research on the Influencing Factors of Maoming Agricultural Development
Authors: Xu Yanli , Lin Yuhua , Eugene Stanley H.
Published: August 2019

Agriculture is a very important industry in a country or region. In order to promote the development of agricultural production in Maoming City, this paper uses the econometric method to conduct quantitative empirical analysis of Maoming City’s agricultural development. The results show that Maoming City’s planting, forestry, animal husbandry and fishery have promoted the agricultural development of Maoming City. Therefore, it can be concluded that in order to accelerate the development of agriculture in Maoming City, investment in planting, forestry, animal husbandry and fishery should be increased.
Analysis of Military-Civil Interaction in Emergency Management based on C2 Model
Authors: Cheng Genyin , Liu Hongwei
Published: August 2019

In recent years, with the frequent occurrence of emergencies in China, more urgent requirements have been put forward for the improvement of emergency management system. As one of the important forms of emergency management, military-civilian joint action plays an important role in emergency rescue. However, in the past cases, there are still many problems in the process of local and military participation in emergency rescue, resulting in poor rescue effect. Command and Control (C2) model is a classical model in military command and control. It can analyze the military-civilian linkage system intuitively and systematically, and summarize the characteristics of each maturity level of C2 model to form a table. Based on this, the maturity of the military-civilian linkage accident rescue process is evaluated and the existing problems are analyzed, and the needle is put forward. The measures for sexual improvement and further optimization of the military-civilian linkage system provide experience support for the improvement of emergency management system in China.
Numerical Simulation on Dynamic Behavior of High-speed Railway Cutting Bedding in Expansive Soil Area
Authors: Hu Min , Yang Guolin
Published: August 2019

The cutting bedding defect of expansive soli is one of the most difficult problems in railway constructions. Based on analysis results of the character and mechanism of subgrade disease, semi-rigid waterproof and drainage structure layer is researched, fully-enclosed subgrade is designed. Based on work of predecessors, the article simplify the train load equation and study the dynamic characters of new cutting and bedding. The results show that laying waterproof and drainage structure can increase the speed of decay of dynamic stress in the bedding, decrease the dynamic displacement of bedding surface substantially, and make the standard of high speed railway.
Lower Explosion Limits Measurements and Prediction for Binary Liquid Mixtures
Authors: Cao Jiakai , Ding Li , Pan Yong , Zhao Jianping
Published: August 2019

The lower explosion limit (LEL) is an important physicochemical parameter for characterizing the flammable and explosive hazard potential of chemicals. In this study, the LEL values of 21 groups of binary liquid mixtures with different compositions and ratios were tested, and the change law of LEL with compositions and ratios were revealed. Then four different physicochemical parameters were employed as the input parameters for the LEL prediction of mixtures. Both the multiple linear regression (MLR) and multiple nonlinear regression (MNR) methods were employed to model the possible quantitative relationships between these parameters and the LEL of binary mixtures. The resulted models showed satisfactory prediction ability, with the average absolute error being 0.188% for the MLR model and 0.196% for the MNR model, respectively. Model validations were also performed to check the stability and predictivity of the presented models, and the results showed that both models were valid and predictive requiring only some common physicochemical parameters of the pure components. This study can provide a simple, yet accurate way for engineering to predict the LELs of binary liquid mixtures as applied in the assessment of fire and explosion hazards and the development of inherently safer designs for chemical processes.
Soil Moisture Inversion with Sparse Vegetation Coverage Areas and Analysis of Spatial Characteristics Based on RADARSAT-2
Authors: Kong Hui
Published: August 2019

Backscatter coefficient of radar imagery is mainly affected by the surface soil moisture and roughness. This paper was based on the RADARSAT-2 polarimetric SAR image data, field measured soil moisture data, surface roughness, soil particle composition and soil bulk density data. The soil moisture from SAR was retrieved by using Oh2004 semi empirical model inversion method, Oh2004 semi empirical model LUT method, AIEM theory model which is based on the effective correlation length and AIEM theory model on account of the effective RMS height. After soil moisture retrieval of the study area sampling points at 0-6cm depth, this study analyzed the corresponding to the four kinds of methods of the optimal filtering window size, made a comparative analysis of the four methods and determined the optimum inversion model of the study area soil moisture microwave remote sensing at 0-6cm depth. This article used the best model for retrieving soil moisture in depth of 0-6cm, made the distribution map of soil moisture at 0-6cm depth, and analyzed spatial distribution characteristics.
Study on the Distribution of Heavy Metals in Atmospheric Dustfall in the Area around Linyi University
Authors: Qiu Jicai , Liang Renjun , Ren Liying , Qin Pengfei , Ma Hongqing
Published: August 2019

This paper analyses the atmospheric dust in Linyi City about the content and the form distribution of heavy metals. The main research focuses on the eight kinds of heavy metal elements, including As, Cd, Cr, Cu, Hg, Mn, Pb, Zn. The research results show that the formation distribution of heavy metal element is differ, the morphology of Mn and Cu detection rate of 100%, with five kinds of form exist; Cu, Zn, Mn, Pb, Cd in the exchangeable ions and carbonate combined states accounted for 20% of the proportion of high proportion. Cr, Cd, heavy metal forms with exchangeable ions state, carbonate state, iron, manganese oxide combination state, which accounts for 80% to 95% of the total, unstable state 20% has some impact on the environment and the human body.
Research on Sequence Stratigraphy of Nantun Formation in Bayanhushu Depression of Hailar Basin and Favorable Target Prediction
Authors: Zou Yue
Published: August 2019

Exploration in Bayanhushu depression has been published from time to time, showing great exploration potential, but the degree is low at present. We devided Nantun formation into two third sequences through comprehensive analysis and studied on the types and distribution of sedimentary facies. The conclusion shows that Nantun formation is mainly comprised of fan delta, braid delta and lacustrine facies. The fan delta sedimentary facies mainly distribute in the western steep slope zone, while the braided river delta develops in the eastern gentle slope zone, and the lacustrine facies mainly develops in the middle trough zone and the edge of the fan delta. The sedimentary pattern has the characteristics of “east-west zoning”. From the steep slope to the gentle slope, the types of sedimentary facies gradually change from fan delta to shore-shallow lake, semi-deep lake to deep lake and then to braided river delta. The study of source-reservoir-cap assemblages and accumulation conditions shows that fan delta front and braided delta front have good physical properties and are close to high grade source. So it is easy to form inversion structural reservoirs in the steep slope break zone, while fault-lithologic reservoirs in gentle slope zone, a lithologic reservoirs near trough areas.
Design of Microgrid Simulation System
Authors: Du Haohao , Li Yongjun , Li Tingting
Published: August 2019

For reasonable deal with the relationship between the public power grid and distributed generation, this design by micro grid simulation system as an object, mainly studies the design method of grid inverter, completed the grid inverter hardware system and control system design, and on the basis of the above work, the micro grid simulation system is designed by simulation analysis and experimental verification. Simulation and experimental results show that the designed system can simulate island operation and grid-connected operation, and has complete functional indexes and higher performance indexes, which verify the correctness and rationality of the designed system.
Material Analysis and Design of Air Purifier
Authors: Fang Jiani , Zhu Zhiwei
Published: August 2019

With the development of economy, the damage to the environment caused by industrial development is becoming more and more obvious. When people pursue material and spiritual matters, it is inevitable to consider the improvement of air quality that is closely related to our life. In order to improve the air, appeared on the market many air purifier, hoping to improve air quality in a certain space. Air purifiers have attracted people’s attention once they are on the market, and businesses are constantly improving air purifiers to meet people’s different needs and improve the competitiveness of products. With the aim to study the air purifier, the shape size, molding materials, processing technology and so on has carried on the thorough analysis, it is concluded that the link between design and material molding and processing technology.
Preliminary Study on the Characteristics of Laser Underwater Proximity Transmission
Authors: Shen Na , Yang Yuyue , Dai Wei , Hu Xin
Published: August 2019

Due to the special circumstances of underwater channel environment, laser underwater communication technology is facing challenges. The characteristics of underwater channel have been simulated and tested in this paper. Firstly, the scattering model and Monte-Carlo simulation method based on Mie scattering are established. Secondly, the simulation test on the influence of laser transmission under different parameter conditions is carried out. Finally, the design of the laser signal receiving system and the laser underwater transmission experiment are designed. The method of reducing the signal to noise ratio is analyzed and put forward. The experimental research is also carried out to verify the correctness of the simulation results. The experimental results show that with the increase of transmission distance, the diameter and density of scattering particles, the time domain broadening, space broadening and energy absorption of the laser will reduce the received light energy transfer signal, the sine wave will be distorted and the transmission will be affected effectiveness.
Design and Implementation of Flight Monitoring Simulation Training System
Authors: Pan Gaofeng , Su Yan , Liu Sifang , Li Pei
Published: August 2019

The calibration flight is an important technical means to verify the performance and accuracy of the TT&C equipment. In the flying, the equipment is power-on/power-off and the transponder mode is switched according to the needs. The transponder is a borrower. In the case of giving-back, it is especially important to recurring maintenance for the attachment. Through the system design, the original monitoring standby machine, the analog power supply chassis and the analogue controllers state of the transponder state, and three Bosch card and one serial server are used to fully simulate the on-board application environment. The industrial tablet application software adopts C# design to realize effective information interaction with the monitoring standby machine through serial port and network communication. The characteristics of the system are the continuous assessment of the power-on maintenance of spare parts, personnel training and actual system software, which is of great significance to the actual work.
Phased-array Surface Monitoring Method Based on Compensation Correction Technique
Authors: Xie Yong , Liu Sifang , Ding Ran , Li Pei
Published: August 2019

Phased-array radar has a huge array of microwave feeding network and antenna lobe performance depends on the array amplitude and phase errors. Therefore, it is necessary to monitor the array surface to ensure the performance of the array. In the traditional test method, there is a bad test precision and slow speed. In this paper, a monitoring method based on compensation correction technique is proposed. The inside and outside of the measurement method, two kinds of tests complement each other, can cover the unit level, ensure the favorable array amplitude and phase characteristics, to provide important support for high precision tracking.
Rotational Speed Analysis of Shipboard Turbo-generator Considering Efficiency Change after Sudden Load
Authors: Zhu Yongxin , Zhang Xiaofeng , Huang Jing
Published: August 2019

Based on classical analytical process of cylinder efficiency, the mechanism of efficiency change during turbo-generator power adjustment is revealed, and the influence of cylinder efficiency change on calculation of generator loading limit is studied and tested by using PSCAD software. The result indicates that, efficiency deviation caused by sudden load is helpful for the recovery of system power balance, and that the negligence of power deviation caused by efficiency decrease under overload circumstances may reverse the analytical result. Reliable control of power station is the key to stable operation of shipboard power grid. The research between cylinder efficiency and generator power adjustment can provide reference for further operation design and coordinated control.
Application of Center Approximation Ideal Point Method in Evaluation of Well Pattern Encryption Effect
Authors: Li Meifang , Jia Shihua
Published: August 2019

Since 1996 the research of well pattern infilling technology has been developed in seventy three blocks of Daqing peripheral oilfields. In order to evaluate the development effect of infilling blocks, this paper improved the normalized method and computational method of the distance between every filling plan and the positive ideal plan in the TOPSIS with interval-valued weight. The indexes which can evaluate development effect of infilling blocks were given in this paper, and part of the infilling blocks of Chaoyanggou oilfield were evaluated by the integrated approach of ideal point solution. The integrated approach of ideal point solution is not only a new quantitative method but also the theoretical foundation and technical support to evaluate the development effect of infilling blocks.
Study on Spontaneous Combustion Law of Goaf in 31301 Working Face of Chahasu Coal Mine
Authors: Cheng Genyin , Wang Yuhuai , Liu Jian
Published: August 2019

Aiming at the serious problem of spontaneous combustion of coal seam in 31301 working face of ChahaSu Mine. Firstly, the industrial analysis of coal samples in the working face shows that the coal quality of the working face belongs to non-caking coal, which has the characteristics of low ignition point, high moisture content and no caking. By testing the marked gases of spontaneous combustion of coal samples, it is concluded that CO and C2H4 can be used as the representative gas of spontaneous combustion of coal oxidation to judge the spontaneous combustion of coal seams. According to the field monitoring data, the three-zone distribution of spontaneous combustion is calculated, and compared with the three-zone distribution of spontaneous combustion under the condition of fully closed simulation, the factors affecting the three-zone distribution of spontaneous combustion are obtained. Combining with the results of experimental analysis, the law of spontaneous combustion is studied and the reasonable advancing speed of working face is determined, which provides theoretical support for the formulation of enterprise fire prevention and extinguishing measures.
Tomato’s Mechanical Properties Measurement Aiming for Auto-harvesting
Authors: Feng Qingchun , Wang Guohua , Wang Shuai , Wang Xiu
Published: August 2019

Freshly-eating tomato’s auto-harvesting is urgently needed to replace labor-costly manual harvesting. And a feasible picking end-effector is a key part for mechanical harvesting, as the irregular-sized and soft fruits should be reliably separated from the plant. In this paper, the mechanical properties of “Jiali 14” tomato was measured and analysed to support the design of picking end-effector. The methods and devices for measuring a series of force parameters were researched, including fruit/stalk friction coefficient, fruit pressure resistance, stalk cutting force, and abscission-layer breakage force. Through measuring the pressure and maximum static-friction force between the fruit/stalk and the contrast material, the friction coefficients between fruit/stalk and stainless steel, PVC and rubber was calculated. The pressure resistance of fruit also was evaluated by measuring the extreme pressure on the test samples, and the influences from the fruit’s maturity and the pressure direction also were analysed. The stalk cutting force, with the single and double blade, both was measured and compared. The breakage force of the calyx abscission-layer and the tie abscission-layer also was measured, and the force value variation with its anisotropy and the fruit maturity was analysed. The measurement and analysis result in this paper was supposed as a necessary reference for developing the tomato’s auto-harvesting machine.
Back Propagation Artificial Neural Network Modeling and Migration Analysis of Siloxane D5 Migration from Selected Food Contact Materials
Authors: Wang Xiujuan , Thu Aung Myat , Liu Suting , Sheng Anbang , Song Meng
Published: August 2019

The detection and quantification of environmental pollution compounds migration in food contact silicone rubber materials remains a prospective issue to be solved in the consideration of toxicology and safety assessment. In this study, an artificial neural network (ANN) model was established to predict migration property of non-target compound decamethylcyclopentasiloxane (D5) molecule in food contact silicone rubber. The average prediction accuracy of the model was 99.8%. The analysis of ANN indicates that high temperature condition accelerates the migration of D5 from silicone rubber into two typical food simulants, namely H2O and acetic acid. The migration of D5 is more apparent when the silicone rubber is in contact with acetic acid. The combination of experiment and simulation analysis of D5 migration indicates that high temperature and acetic acid food simulant environment threaten the safety of food contact silicone rubber. These fundamental studies can provide a comprehensive understanding of the migration of cyclic organosiloxane oligomer from silicone rubber and guidance for the safety evaluation and early warning mechanisms.
The frustration of being odd: universal area law violation in local systems
Authors: Giampaolo Salvatore Marco , Ramos Flavia Brága , Franchini Fabio
Published: August 2019

At the core of every frustrated system, one can identify the existence of frustrated rings that are usually interpreted in terms of single–particle physics. We check this point of view through a careful analysis of the entanglement entropy of both models that admit an exact single–particle decomposition of their Hilbert space due to integrability and those for which the latter is supposed to hold only as a low energy approximation. In particular, we study generic spin chains made by an odd number of sites with short-range antiferromagnetic interactions and periodic boundary conditions, thus characterized by a weak, i.e. nonextensive, frustration. While for distances of the order of the correlation length the phenomenology of these chains is similar to that of the non-frustrated cases, we find that correlation functions involving a number of sites scaling like the system size follow different rules. We quantify the long-range correlations through the von Neumann entanglement entropy, finding that indeed it violates the area law, while not diverging with the system size. This behavior is well fitted by a universal law that we derive from the conjectured single–particle picture.
Masculinized Male Chest Contouring: Creating the Armor Plate
Authors: Mowlavi Arian , Rashid Waleed , Berri Mariam , Talle Armin
Published: August 2019

Male patients are routinely consulted regarding dislike of their chest appearance. To date, majority of patients have desired elimination of their feminine-appearing breast, termed gynecomastia. These patients have associated their overweight body image, with the femininity of their breasts as presented by fullness and roundedness of their breasts and subsequently have desired maximal flattening of their breast. We present a new set of patients who desire a more muscular-appearing chest than a gynecomastia repair that is interposed on a chiseled abdominal contour. In contrast to the former set of patients, these patients desire bulking of their breasts with a bolder-appearing armor plate look. We present an alternative to traditional gynecomastia repair which involves a novel approach to chest contouring creating a flat, yet bold, pentagonal-shaped breast with linear borders utilizing both fat and gland removal as well as strategic fat grafting back into the chest. We present a novel protocol to create an armor plate male chest appearance as an alternative to traditional gynecomastia contouring. All patients treated to date demonstrate a muscular-appearing chest that is harmonious on an interposed masculine-appearing abdomen.
Knot_pull—python package for biopolymer smoothing and knot detection
Authors: Jarmolinska Aleksandra I , Gambin Anna , Sulkowska Joanna I
Published: August 2019

The biggest hurdle in studying topology in biopolymers is the steep learning curve for actually seeing the knots in structure visualization. Knot_pull is a command line utility designed to simplify this process—it presents the user with a smoothing trajectory for provided structures (any number and length of protein, RNA or chromatin chains in PDB, CIF or XYZ format), and calculates the knot type (including presence of any links, and slipknots when a subchain is specified).

Availability and implementation

Knot_pull works under Python >=2.7 and is system independent. Source code and documentation are available at http://github.com/dzarmola/knot_pull under GNU GPL license and include also a wrapper script for PyMOL for easier visualization. Examples of smoothing trajectories can be found at: https://www.youtube.com/watch?v=IzSGDfc1vAY.

Supplementary information

Supplementary data are available at Bioinformatics online.
In-Frame Indel Mutations in the Genome of the Blind Mexican Cavefish, Astyanax mexicanus
Authors: Berning Daniel , Adams Hannah , Luc Heidi , Gross Joshua B
Published: August 2019

Organisms living in the subterranean biome evolve extreme characteristics including vision loss and sensory expansion. Despite prior work linking certain genes to Mendelian traits, the genetic basis for complex cave-associated traits remains unknown. Moreover, it is unclear if certain forms of genetic variation (e.g., indels, copy number variants) are more common in regressive evolution. Progress in this area has been limited by a lack of suitable natural model systems and genomic resources. In recent years, the Mexican tetra, Astyanax mexicanus, has advanced as a model for cave biology and regressive evolution. Here, we present the results of a genome-wide screen for in-frame indels using alignments of RNA-sequencing reads to the draft cavefish genome. Mutations were discovered in three genes associated with blood physiology (mlf1, plg, and wdr1), two genes associated with growth factor signaling (ghrb, rnf126), one gene linked to collagen defects (mia3), and one gene which may have a global epigenetic impact on gene expression (mki67). With one exception, polymorphisms were shared between Pachón and Tinaja cavefish lineages, and different from the surface-dwelling lineage. We confirmed the presence of mutations using direct Sanger sequencing and discovered remarkably similar developmental expression in both morphs despite substantial coding sequence alterations. Further, three mutated genes mapped near previously established quantitative trait loci associated with jaw size, condition factor, lens size, and neuromast variation. This work reveals previously unappreciated traits evolving in this species under environmental pressures (e.g., blood physiology) and provides insight to genetic changes underlying convergence of organisms evolving in complete darkness.
Associations of Body Composition Trajectories with Bone Mineral Density, Muscle Function, Falls, and Fractures in Older Men: The Concord Health and Ageing in Men Project
Authors: Scott David , Seibel Markus J , Cumming Robert , Naganathan Vasi , Blyth Fiona , Le Couteur David G , Handelsman David J , Hsu Benjumin , Waite Louise M , Hirani Vasant
Published: August 2019

Background

Weight loss increases fracture risk in older adults. We aimed to determine associations of 2-year body composition trajectories with subsequent falls and fractures in older men.

Methods

We measured appendicular lean mass (ALM) and total fat mass (FM) by dual-energy X-ray absorptiometry at baseline and Year 2 in 1,326 community-dwelling men aged ≥70 and older. Body composition trajectories were determined from residuals of a linear regression of change in ALM on change in FM (higher values indicate maintenance of ALM over FM), and a categorical variable for change in ALM and FM (did not lose [≥−5% change] versus lost [<−5% change]). Bone mineral density (BMD), hand grip strength, and gait speed were assessed at Years 2 and 5. After Year 2, incident fractures (confirmed by radiographical reports) and falls were recorded for 6.8 years.

Results

Compared with men who did not lose ALM or FM, men who did not lose ALM but lost FM, and men who lost both ALM and FM, had reduced falls (−24% and −34%, respectively; both p < .05). Men who lost ALM but did not lose FM had increased falls (incidence rate ratio = 1.73; 95% CI 1.37–2.18). ALM/FM change residuals were associated with improved lumbar spine BMD (B = 0.007; 95% CI 0.002–0.012 g/cm2 per SD increase) and gait speed (0.015; 0.001–0.029 m/s), and reduced hip fractures (hazard ratio = 0.68; 95% CI 0.47–0.99).

Conclusions

Fracture risk may be increased in older men who lose higher ALM relative to FM. Weight loss interventions for obese older men should target maintenance of lean mass.
Prevalence and Patterns of Multimorbidity in a Nationally Representative Sample of Older Chinese: Results From the China Health and Retirement Longitudinal Study
Authors: Yao Shan-Shan , Cao Gui-Ying , Han Ling , Chen Zi-Shuo , Huang Zi-Ting , Gong Ping , Hu Yonghua , Xu Beibei
Published: August 2019

Background

Multimorbidity has become a prominent problem worldwide; however, few population-based studies have been conducted among older Chinese with multimorbidity. This study aimed to examine the prevalence of multimorbidity and explore its common patterns among a nationally representative sample of older Chinese.

Methods

This study used data from the China Health and Retirement Longitudinal Study and included 19,841 participants aged at least 50 years. The prevalence of individual chronic diseases and multimorbidity during 2011–2015 were evaluated among the entire cohort and according to residential regions and gender. The relationships between participants’ demographic characteristics and multimorbidity were examined using logistic regression model. Patterns of multimorbidity were explored using hierarchical cluster analysis and association rule mining.

Results

Multimorbidity occurred in 42.4% of the participants. The prevalence of multimorbidity was higher among women (odds ratio [OR] = 1.31, 95% confidence interval [CI]: 1.13–1.51) and urban residents (OR = 1.14, 95% CI: 1.02–1.27) than their respective counterparts after accounting for potential confounders of age, education, smoking, and alcohol consumption. Hierarchical cluster analysis revealed four common multimorbidity patterns: the vascular-metabolic cluster, the stomach-arthritis cluster, the cognitive-emotional cluster, and the hepatorenal cluster. Regional differences were found in the distributions of stroke and memory-related disease. Most combinations of conditions and urban–rural difference in multimorbidity patterns from hierarchical cluster analysis were also observed in association rule mining.

Conclusion

The prevalence and patterns of multimorbidity vary by gender and residential regions among older Chinese. Women and urban residents are more vulnerable to multimorbidity. Future studies are needed to understand the mechanisms underlying the identified multimorbidity patterns and their policy and interventional implications.
Seasonal Declines in Cry1Ac and Cry2Ab Concentration in Maturing Cotton Favor Faster Evolution of Resistance to Pyramided Bt Cotton in Helicoverpa zea (Lepidoptera: Noctuidae)
Authors: Carrière Yves , Degain Ben , Unnithan Gopalan C , Harpold Virginia S , Li Xianchun , Tabashnik Bruce E
Published: August 2019

Under ideal conditions, widely adopted transgenic crop pyramids producing two or more distinct insecticidal proteins from Bacillus thuringiensis (Bt) that kill the same pest can substantially delay evolution of resistance by pests. However, deviations from ideal conditions diminish the advantages of such pyramids. Here, we tested the hypothesis that changes in maturing cotton producing Cry1Ac and Cry2Ab affect evolution of resistance in Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), a pest with low inherent susceptibility to both toxins. In terminal leaves of field-grown Bt cotton, the concentration of both toxins was significantly higher for young, squaring plants than for old, fruiting plants. We used laboratory bioassays with plant material from field-grown cotton to test H. zea larvae from a strain selected for resistance to Cry1Ac in the laboratory, its more susceptible parent strain, and their F1 progeny. On young Bt cotton, no individuals survived to pupation. On old Bt cotton, survival to pupation was significantly higher for the lab-selected strain and the F1 progeny relative to the unselected parent strain, indicating dominant inheritance of resistance. Redundant killing, the extent to which insects resistant to one toxin are killed by another toxin in a pyramid, was complete on young Bt cotton, but not on old Bt cotton. No significant fitness costs associated with resistance were detected on young or old non-Bt cotton. Incorporation of empirical data into simulations indicates the observed increased selection for resistance on old Bt cotton could accelerate evolution of resistance to cotton producing Cry1Ac and Cry2Ab in H. zea.
Amyand hernia: scrotal pyocele, associated with perforated vermiform appendix and complicated by testicular ischemia in neonate
Authors: Omran Ammar , Gawrieh Bardisan Sleman , Abdo Aras , Ali Deeb Mohammad , Khalil Mohammad Almahmod , Shater Waseem
Published: August 2019

The presence of vermiform appendix in an inguinal hernia sac is known as Amyand’s hernia. This research paper examines the case of a 28-day-old Syrian male presented with a history of an infected right-sided hydrocele from the age of 14 days. Upon admission, ultrasonography was reported as a right testicular torsion. Accordingly, emergency surgical exploration was performed, and by exposing the spermatic cord fascia, 7 mL of pus was drained, revealing the cecum and perforated appendix lying beside the right testis, which showed evidence of ischemia and bluish discoloration.
Incidence of laboratory-confirmed Zika in Israeli travelers to Thailand: 2016–2019
Authors: Leshem Eyal , Lustig Yaniv , Brosh-Nissimov Tal , Paran Yael , Schwartz Eli
Published: August 2019

To estimate the incidence of Zika infection in Israeli travelers who visited Thailand during 2016-2019, we extracted laboratory confirmed cases and used annual number of Israeli entries as Denominator. The risk for laboratory confirmed Zika in travelers was 0.97 per 100000 entries with an increased incidence during early 2019.
A Longitudinal Study of S. aureus Infection in a National Cohort of Surgical Patients
Authors: O’brien William J , Gupta Kalpana , Itani Kamal M F
Published: August 2019

Background

Postoperative infections are a common and often preventable complication of surgery. Staphylococcus aureus is a prevalent organism cultured in these infections and is associated with morbidity, mortality, and increased health care utilization. However, the long-term burden of S. aureus infection in surgical patients is not well studied. The purpose of this retrospective observational study was to assess the incidence, time trend, and burden of S. aureus infection up to 1 year after surgery.

Methods

We obtained manually reviewed data from the VA Surgical Quality Improvement Program (VASQIP) to identify surgeries in all major specialties. These were combined with laboratory microbiology and pharmacy data to identify pneumonia and infections of the urinary tract, surgical site, and blood.

Results

In the study population of 559 550 patients, S. aureus incidence decreased each year, from 2.1% in 2008 to 1.1% in 2015. Among these, incidence of methicillin-resistant S. aureus infection decreased from 0.7% to 0.4%, and methicillin-susceptible S. aureus decreased from 1.4% to 0.7%. S. aureus infection was associated with increased length of stay, emergency department utilization, inpatient admissions, and a 4-fold increase in mortality.

Conclusions

This is one of the largest studies describing the long-term incidence of S. aureus in the surgical population of a national integrated health care system. We conclude that the burden of S. aureus infection extends well beyond the conventional 30-day postoperative window, and late infection should be included in assessing the effects of interventions.