Explore the vast range of titles available.

Divertor detachment offers a promising solution to the challenge of plasma-wall interactions for steady-state operation of fusion reactors. Here, we demonstrate the excellent compatibility of actively controlled full divertor detachment with a high-performance ( β N ~ 3, H 98 ~ 1.5) core plasma, using high-β p (poloidal beta, β p  > 2) scenario characterized by a sustained core internal transport barrier (ITB) and a modest edge transport barrier (ETB) in DIII-D tokamak. The high- β p high-confinement scenario facilitates divertor detachment which, in turn, promotes the development of an even stronger ITB at large radius with a weaker ETB. This self-organized synergy between ITB and ETB, leads to a net gain in energy confinement, in contrast to the net confinement loss caused by divertor detachment in standard H-modes. These results show the potential of integrating excellent core plasma performance with an efficient divertor solution, an essential step towards steady-state operation of reactor-grade plasmas. Plasma fusion devices like tokamaks are important for energy generation but there are many challenges for their steady state operation. Here, the authors show that full divertor detachment is compatible with high-confinement high-poloidal-beta core plasmas and this prevents the damage to the divertor target plates and the first wall.

Four experiments were conducted to evaluate the effectiveness of a computer-controlled simulated digestion system (CCSDS) for predicting apparent metabolizable energy (AME) and true metabolizable energy (TME) using in vitro digestible energy (IVDE) content of feeds for roosters. In Exp. 1, the repeatability of the IVDE assay was tested in corn, wheat, rapeseed meal, and cottonseed meal with 3 assays of each sample and each with 5 replicates of the same sample. In Exp. 2, the additivity of IVDE concentration in corn, soybean meal, and cottonseed meal was tested by comparing determined IVDE values of the complete diet with values predicted from measurements on individual ingredients. In Exp. 3, linear models to predict AME and TME based on IVDE were developed with 16 calibration samples. In Exp. 4, the accuracy of prediction models was tested by the differences between predicted and determined values for AME or TME of 6 ingredients and 4 diets. In Exp. 1, the mean CV of IVDE was 0.88% (range = 0.20 to 2.14%) for corn, wheat, rapeseed meal, and cottonseed meal. No difference in IVDE was observed between 3 assays of an ingredient, indicating that the IVDE assay is repeatable under these conditions. In Exp. 2, minimal differences (<21 kcal/kg) were observed between determined and calculated IVDE of 3 complete diets formulated with corn, soybean meal, and cottonseed meal, demonstrating that the IVDE values are additive in a complete diet. In Exp. 3, linear relationships between AME and IVDE and between TME and IVDE were observed in 16 calibration samples: AME = 1.062 × IVDE - 530 (R(2) = 0.97, residual standard deviation [RSD] = 146 kcal/kg, P < 0.001) and TME = 1.050 × IVDE - 16 (R(2) = 0.97, RSD = 148 kcal/kg, P < 0.001). Differences of less than 100 kcal/kg were observed between determined and predicted values in 10 and 9 of the 16 calibration samples for AME and TME, respectively. In Exp. 4, differences of less than 100 kcal/kg between determined and predicted values were observed in 3 and 4 of the 6 ingredient samples for AME and TME, respectively, and all 4 diets showed the differences of less than 25 kcal/kg between determined and predicted AME or TME. Our results indicate that the CCSDS is repeatable and additive. This system accurately predicted AME or TME on 17 of the 26 samples and may be a promising method to predict the energetic values of feed for poultry.

Groove wick micro heat pipes are characterized by light weight, fast thermal response and high permeability which are in line with the current trend of lightweight electronic devices. As an efficient heat transfer device, flat micro heat pipes (FMHP) have been widely used for thermal management of electronic devices because of their excellent thermal performance and high reliability. In this paper, FMHP with microgrooves wick was processed on the copper substrate by 1064nm pulsed fiber laser. The influence of various laser processing parameters including pulse duration, scanning speed, scanning interval and the number of scanning cycles on the size and morphology of groove structures have been studied. The grooves with different aspect ratio are obtained by changing the number of scanning cycles, and the effects of aspect ratio on the droplet flow velocity are investigated respectively. Experimental results indicate that grooves with larger aspect ratio exhibits greater capillary pressure which leads to a faster droplet flow velocity. Groove wick with the aspect ratio of 2.5 whose average groove depth of 125 um and groove width of 50 urn is fabricated successfully, and the FMHP with the groove wick of this type have the best heat transfer property. Keywords: pulsed fiber laser; copper; groove structure; surface morphology; processing parameters

Four experiments were conducted to evaluate the effectiveness of a computer-controlled simulated digestion system (CCSDS) for predicting apparent metabolizable energy (AME) and true metabolizable energy (TME) using in vitro digestible energy (IVDE) content of feeds for roosters. In Exp. 1, the repeatability of the IVDE assay was tested in corn, wheat, rapeseed meal, and cottonseed meal with 3 assays of each sample and each with 5 replicates of the same sample. In Exp. 2, the additivity of IVDE concentration in corn, soybean meal, and cottonseed meal was tested by comparing determined IVDE values of the complete diet with values predicted from measurements on individual ingredients. In Exp. 3, linear models to predict AME and TME based on IVDE were developed with 16 calibration samples. In Exp. 4, the accuracy of prediction models was tested by the differences between predicted and determined values for AME or TME of 6 ingredients and 4 diets. In Exp. 1, the mean CV of IVDE was 0.88% (range = 0.20 to 2.14%) for corn, wheat, rapeseed meal, and cottonseed meal. No difference in IVDE was observed between 3 assays of an ingredient, indicating that the IVDE assay is repeatable under these conditions. In Exp. 2, minimal differences (<21 kcal/ kg) were observed between determined and calculated IVDE of 3 complete diets formulated with corn, soybean meal, and cottonseed meal, demonstrating that the IVDE values are additive in a complete diet. In Exp. 3, linear relationships between AME and IVDE and between TME and IVDE were observed in 16 calibration samples: AME = 1.062 x IVDE - 530 (R^sup 2^ = 0.97, residual standard deviation [RSD] = 146 kcal/kg, P < 0.001) and TME = 1.050 x IVDE - 16 (R^sup 2^ = 0.97, RSD = 148 kcal/kg, P < 0.001). Differences of less than 100 kcal/kg were observed between determined and predicted values in 10 and 9 of the 16 calibration samples for AME and TME, respectively. In Exp. 4, differences of less than 100 kcal/kg between determined and predicted values were observed in 3 and 4 of the 6 ingredient samples for AME and TME, respectively, and all 4 diets showed the differences of less than 25 kcal/kg between determined and predicted AME or TME. Our results indicate that the CCSDS is repeatable and additive. This system accurately predicted AME or TME on 17 of the 26 samples and may be a promising method to predict the energetic values of feed for poultry.

In a cold roll forming process, the sheet is progressively formed into a three-dimensional surface. In order to reduce forming defects and trial production cost, computer simulation technology is employed in cold roll forming. Based on the updated Lagrange method in deformation mechanics, a theoretical model of elastic-plastic large deformation spline finite strip method is presented in this paper. The method has been employed to analyse the progressive roll forming process of the deformed strip, and the three dimensional displacement, strain, and stress fields between two stands during the multiple cold rolls forming process. The calculation results prove that the outer edge and the corner part of the deformed strip are submitted to larger deformation. The transverse deformation is principal, and the longitudinal deformation is small. This program, written in C language, can also be used to analyse other simple cross-sectional profiles.

Sapphire is an important material for LED substrates. Because of its unique physical property, sapphire is strongly resistant to wet and dry chemical etching. Laser-based scribing techniques have a good prospect on sapphire scribing application. During the laser scribing, the assisting gas significantly affects the scribing depth, width and quality. A pulsed laser with a wavelength of 532 nm is used to scribe the sapphire substrate by twin assisting gas impinging both in co-axis and off-axis. This process is simulated by a computational fluid dynamics code, FLUENT. During the simulation, inlet pressure of co-axial nozzle and off-axial nozzle are varied at different intersection angle. By analyzing the static pressure and flow velocity at different inlet pressure and intersection angle, optimal laser processing parameters are obtained to improve the groove quality and reduce the groove width. Experiments are carried out to testify the simulation result. The result of both the simulation and experiment show that when laser pulse energy is 150µJ with co-axial inlet pressure 2 bar, off-axial inlet pressure 2~3 bar and intersection angle 70°, a better groove quality and an optimal groove size can be obtained.

Good roll pass design is the key to successful roll forming. To reduce forming defects and trial production costs, computer aided simulation of cold roll forming is employed. In this paper, a theoretical model, based on the updated Lagrange method of deformation mechanics and using the elastic-plastic large deformation B-spline finite strip method, is presented. The model is applied to analyse progressive roll forming of a channel section: the three-dimensional displacement field, strain field, and stress field between two stands during multiple cold roll forming are calculated. The results indicate that deformation is greatest in the leg and corner regions of the channel section. The principal deformation is in the transverse direction, the longitudinal deformation being small. The program, written in C language, can also be used to analyse other simple cross-sectional profiles.

Abstract The electro-osmotic flow near an earthworm body surface is a basic electrokinetic phenomenon that takes place when the earthworm moves in moist soil. The flow within a microthin liquid layer near earthworm's body surface is induced by the electric double layer (EDL) interaction. Such a microscale electro-osmotic flow plays a role of lubrication between the earthworm's body surface and the surrounding medium of moist soil and reduces surface adhesion. In the current paper, the electro-osmotic flow near earthworm surface is numerically simulated to further understand the mechanism of antisoil adhesion. A lattice Poisson method is first employed to solve electric potential and charge distributions in the EDL along an earthworm surface; the external electric field is then obtained by solving the Laplace equation. The motion of electro-osmotic flow controlled by Navier-Stokes equations is simulated by the lattice Boltzmann method. Typically, the simulation of electro-osmotic flow shows that moving vortices, which likely contribute to antisoil adhesion, can be formed near the earthworm body surface by the non-uniform and variational electrical force.

Purpose - The main objective of this work is to develop a boundary treatment in lattice Boltzmann method (LBM) for curved and moving boundaries and using this treatment to study numerically the flow around a rotating isothermal circular cylinder with without heat transfer.Design methodology approach - A multi-distribution function thermal LBM model is used to simulate the flow and heat transfer around a rotating circular cylinder. To deal with the calculations on the surface of cylinder, a novel boundary treatment is developed.Findings - The results of simulation for flow and heat transfer around a rotating cylinder including the evolution with time of velocity field, and the lift and drag coefficients are compared with those of previous theoretical, experimental and numerical studies. Excellent agreements show that present LBM including boundary treatment can achieve accurate results of flow and heat transfer. In addition, the effects of the peripheral-to-translating-speed ratio, Reynolds number and Prandtl number on evolution of velocity and temperature fields around the cylinder are tested.Practical implications - There is a large class of industrial processes which involve the motion of fluid passing rotating isothermal circular cylinders with without heat transfer. Operations ranging from paper and textile making machines to glass and plastics processes are a few examples.Originality value - A strategy for LBM to treat curved and moving boundary with the second-order accuracy for both velocity and temperature fields is presented. This kind of boundary treatment is very easy to implement and costs less in computational time.

Bamboo is a typical natural composite material, and its special structure and excellent properties provide important information for the biomimetic design of composites. To strengthen the fiber content of bamboo distributed in a gradient, a bimimetic nano-Al2O3 composite coating was designed and prepared on the surface of metal parts using a nanocomposite electrodeposition method. The optimal technology parameters were obtained, such as current density, PH value, nano-Al2O3 content in electrolyte, and style of stirring etc after the experiments. The microstructure of the biomimetic nanocomposite gradient coating was very dense, and the contents of nano-Al2O3 were distributed in the gradient. The microhardness of the composite coating changed from the surface to the inside in the gradient also. Moreover, the wetting angle between water and composite coating obviously increased and reached 97°at room temperature.