Characteristics Of Layer Research Articles

Investigation on the influence of mesoscale geometric features on the surface white layer characteristics in titanium alloy milling using ball end mills

A white layer will be generated on the machined surface when milling titanium alloy. Its existence will make the surface of the workpiece more brittle, and it is easy to produce cracks during the machining process, which greatly harms machining. Aiming at this problem, this paper takes the ball-end milling cutter with mesoscopic geometric characteristics as the research object, establishes the theoretical model of the white layer thickness of the workpiece under the micro-texture and cutting edge factors, analyzes the single factor of micro-texture parameters and cutting edge parameters, and the interaction between them and cutting parameters on the milling force-thermal characteristics and the white layer of the workpiece. The influence law reveals its mechanism from the macro and micro perspectives. It uses the white layer thickness as the evaluation index to optimize the mesoscopic geometric characteristic parameters by using the simulated annealing algorithm. The results demonstrate that the mesoscopic geometric feature of the ball-end milling cutter effectively reduces the thickness of the white layer, achieving a 38% reduction compared to that observed with a non-textured milling cutter. The thickness of the white layer exhibits a positive correlation with the distance L from the blade and a negative correlation with the edge radius R. The interaction between the cutting edge radius R and the cutting depth a p influences the milling force and heat, alters the micro-texture of the workpiece surface, induces the α + β phase transformation, and affects the white layer thickness. Based on the predictive model for white layer thickness, the optimization results for comprehensive milling performance are as follows: R is 59.39 μm, L is 110.01 μm, D is 58.68 μm, L1 is 130.59 μm, a p is 0.30 mm, V is 147.39 mm/min, f is 0.08 mm/z.

Artificial synapses based on HfOx/TiOy memristor devices for neuromorphic applications

As a result of enormous progress in nanoscale electronics, interest in artificial intelligence (AI) supported systems has also increased greatly. These systems are typically designed to process computationally intensive data. Parallel processing neural network architectures are particularly noteworthy for their ability to process dense data at high speeds, making them suitable candidates for AI algorithms. Due to their ability to combine processing and memory functions in a single device, memristors offer a significant advantage over other electronic platforms in terms of area scaling efficiency and energy savings. In this study, single-layer and bilayer metal-oxide HfOxand TiOymemristor devices inspired by biological synapses were fabricated by pulsed laser and magnetron sputtering deposition techniques in high vacuum with different oxide thicknesses. The structural and electrical properties of the fabricated devices were analysed using x-ray reflectivity, x-ray photoelectron spectroscopy, and standard two-probe electrical characterization measurements. The stoichiometry and degree of oxidation of the elements in the oxide material for each thin film were determined. Moreover, the switching characteristics of the metal oxide upper layer in bilayer devices indicated its potential as a selective layer for synapse. The devices successfully maintained the previous conductivity values, and the conductivity increased after each pulse and reached its maximum value. Furthermore, the study successfully observed synaptic behaviours with long-term potentiation, long-term depression (LTD), paired-pulse facilitation, and spike-timing-dependent plasticity, showcasing potential of the devices for neuromorphic computing applications.

Effect of Dual Shot Peening on Microstructure and Wear Performance of CNT/Al-Cu-Mg Composites.

This work systematically investigated the effect of dual shot peening (DSP) and conventional shot peening (CSP) on the microstructure, residual stress and wear performance of the CNT/Al-Cu-Mg composites. The results indicated that compared with CSP, DSP effectively reduced surface roughness (Rz) from 31.30 to 12.04 μm. In parallel, DSP introduced a smaller domain size (33.1 nm) and more dislocations, higher levels compressive residual stress and a stiffer deformation layer with deeper affected zones. Moreover, DSP effectively improved the uniformity of the surface layer's microstructure and residual stress distribution. The improvement is mainly due to secondary impact deformation by microshots and fine grain strengthening. In addition, the transformation of the hard second phases such as Al4C3 and CNT and its effects on improving the surface strength and deformation uniformity were discussed. Significantly, DSP improved the wear resistance by 31.8% under the load of 6 N, which is attributed to the synergistic influence of factors including hardness, compressive residual stress, surface roughness, and grain size. In summary, it can be concluded that DSP is an effective strategy to promote the surface layer characteristics for CNT/Al-Cu-Mg composites.

High‐efficiency solar selective absorber: Using the high‐entropy nitride MoTaTiCrN nanoceramics as a perspective strategy

AbstractHigh‐entropy materials have sparked significant interest in varied applications, particularly in solar‐thermal technologies such as solar‐driven desalination and concentrating solar power (CSP) systems. In this context, high‐entropy nitrides, as novel solar selective absorbers (SSAs) materials, play a crucial role in these applications, demonstrating excellent spectral selectivity and strong thermal and chemical stability at high temperatures and in harsh environments. However, the underlying sunlight absorption mechanisms, atomic‐level structures, and programmatic design route of these SSAs still need further investigation. Herein, a high‐entropy alloy (MoTaTiCr) target was used to construct gradient high‐entropy nitride films via magnetron sputtering in the nitrogen atmosphere. The atomic‐level microstructure study revealed the crystal structure characteristics in the MoTaTiCrN layer. Computer simulations and density functional theory calculations aided in the design and understanding of the possible solar absorption mechanisms. The as‐deposited SSA exhibited impressive optical properties (α = 95.2%; ε = 6.8%) and demonstrated excellent thermal robustness, maintaining performance after long‐term annealing at 600°C for 300 h. Its photothermal conversion efficiency reached 87.9% at 600°C under 100 suns. As a proof‐of‐concept demonstration, the SSA, used in a solar‐powered photothermal desalination unit, showed a high evaporation efficiency since the excellent optical performance as well as the thermal management.

Effect of Fluid Paraffin on the Formulation Properties of Pressure Sensitive Adhesive Formulations Containing Diclofenac Sodium.

Understanding the relationship between the release characteristics of the active ingredient in the tape formulation and the pharmaceutical characteristics of the adhesive layer can optimize therapeutic efficacy and improve patient adherence. This study aimed to clarify the effect of liquid paraffine (LP)/styrene-isoprene-styrene (SIS) triblock copolymer ratio on pressure-sensitive adhesive (PSA) formulation properties, such as adhesive properties and drug release, with a certain amount of diclofenac sodium (DFS) and tackifier. The effects of changes in PSA composition in DFS-containing tape formulations on adhesive and drug release properties were evaluated. The viscoelasticity results showed rigid gel-like behavior at low angular frequencies regardless of the LP/SIS ratio, and deformable gel-like behavior at high angular frequencies, with a maximum plasticizing effect of LP up to an LP/SIS ratio of 3.7. The peel adhesion test results showed that peel adhesion was not affected, but indicated a decreasing trend by increasing the LP/SIS ratio in the presence of DFS. Drug release test results showed that DFS release increased up to 24h for LP/SIS ratios of up to 3.7, but decreased when the LP/SIS ratio was 6. The results of the drug permeation tests were similar to those of the drug release tests. In conclusion, it is possible to change the drug release properties by changing the amount of LP in the tape formulation; however, no definitive correlation was found between the adhesive and drug release properties.

Insight into the 2021 Semeru volcano eruption from rapid monitoring of its pyroclastic deposits using Google Earth Engine and multi-sensor data

The objective of this study is to map the pyroclastic deposits resulting from the Semeru eruption in 2021 and to analyse the process of pyroclastic deposit formation, including the tephra and lithification phases, using multi-sensor data. The distribution of pyroclastic deposits was mapped using machine learning algorithms, Sentinel 2 and Sentinel 1 imagery on Google Earth Engine. Data acquisition in the Semeru volcano area was conducted both prior to and following the 2021 eruption. Additionally, field investigations were conducted to analyse the distribution of pyroclastic deposits, including the characteristics of individual layers, the lithification process of pyroclastic layers, and their relationship with the characteristics of the eruption. The results demonstrate that pyroclastic deposits in the proximal facies are composed of lithic, lapilli tuff, lava and tuff. The mapping results also indicate the presence of volcanic ash deposits in the central facies or summit area of Semeru, exhibiting distinctive characteristics associated with volcanic ash. The 2021 eruption has also resulted in rapid changes to river morphometry, as evidenced by notable shifts in a significant decrease in pixel values for NDVI (−0.0781-0.0625), a significant increase in pixel frequency of EVI (1800–6000), and MNDWI (1700–3000), respectively. The change of pyroclastic fall into consolidated tephra occurred from December 2021 to May 2023, where in May 2023 volcanic ash had changed into tuff and lapilli had changed into lapilli tuff. Furthermore, data from Sentinel-1 indicated that pyroclastic flows could be identified using both vertical and horizontal polarization. It can therefore be concluded that the 2021 eruption of Semeru exhibited distinctive characteristics of pyroclastic deposits, where some of the characteristics of the pyroclastic distribution can be monitored rapidly with Google Earth Engine. Therefore, the use of Google Earth Engine with integration of radar and optical data can be recommended to mapping pyroclastic deposits rapidly.

Evaluation of Boundary Layer Characteristics at Mount Si’e Based on UAV and Lidar Data

The atmospheric boundary layer is a crucial transitional region connecting the surface with the free atmosphere, playing a bridging role in land-sea-air interactions and the interactions between different atmospheric layers. This study utilizes rotary-wing UAVs, high-resolution lidar, and WRF simulation data to analyze the vertical distribution characteristics of temperature, humidity, wind speed, and wind direction boundary layer over the Mount Si’e region in 4–6 April 2024. The results indicate that the boundary layer temperature decreases with increasing altitude, reaching up to 18°C, while humidity decreases with height, dropping to as low as 35%. Daytime wind speeds range from 4 to 8 m/s, decreasing to 2 to 4 m/s at night. The boundary layer height can reach up to 900 m during the day and drops to 100–200 m at night, showing distinct diurnal variation characteristics. UAV observations are in good agreement with lidar and WRF simulation results, highlighting the application value of UAVs in high temporal and spatial resolution boundary layer studies. The study also reveals the significant impact of complex terrain on boundary layer characteristics, providing scientific insights into the dynamic and thermal processes of the boundary layer and offering reference value for improving regional weather forecasting and numerical simulations.

Capsaicin attenuates the effect of inflammatory cytokines in a HaCaT cell model for basal keratinocytes.

The resolution of the skin's inflammatory response is only possible if its barrier function is restored. TRPV1 channel activation plays an important role during inflammation but the effect of this activation on the skin barrier under inflammatory conditions has not been clarified. We hypothesize that it could potentially aid the keratinocyte barrier by reducing inflammatory cytokine release and promoting tight junction development. To explore the role of TRPV1 activation in inflammation, we designed and optimized an in vitro model of keratinocytes with basal epidermal layer characteristics using HaCaT cells and TNFα to induce inflammation. TNFα increased the gene expression of tight junction protein claudin 1 (CLDN1) by at least 2.60 ± 0.16-fold, in a concentration-dependent manner, over a 48h period. The administration of a capsaicin pre-treatment reduced the CLDN1 expression to 1.51 ± 0.16-fold during the first 6h after TNFα induction, whereas IL-8 cytokine release was reduced 0.64 ± 0.17-fold. After 48h, CLDN1 protein levels increased by a factor of 6.57 ± 1.39 compared to cells only treated with TNFα. These results suggest that activation of TRPV1 by capsaicin can potentiate the increase in CLDN1 expression and CLDN1 protein synthesis induced by TNFα in cultured keratinocytes, while reducing the release of IL-8.

Large deformation of variable thickness woven composite preforms considering interlayer difference. Application: Forming simulation of a blade preform

The main objective of this work was to investigate the interlayer difference of 3D orthogonal woven fabrics (3DOWFs) during deformation. Tensile, shear, and compression tests were performed on two types of 3DOWFs with different layer numbers. To determine the variations in the deformation behavior within the fabric, a layer decomposition method was developed. This process involved the decomposition of the fabric into two layers, the inner layer and the outer layer, depending on the difference in structural features of the yarn. Then the deformation characteristics of the inner layer and outer layer were derived based on their series or parallel relationship in the load path. The results indicate that there are noticeable variations in the deformation characteristics among the layers of 3DOWF, which are associated with the interwoven structure of the yarns. In particular, in compression deformation, the difference in yarn structure causes the initial stage (Compressive strain <0.2) of fabric compression deformation to be mostly attributed to the compression of the outer layer. Subsequently, the deformations of the inner layer and outer layer gradually tend to balance. Based on a simple anisotropic hyperelasticity model, the interlayer differences were considered in the blade preform simulation. The simulation result shows a good agreement with the preforming results. The results show that the interlayer difference has a significant impact on the deformation of the blade preform, particularly in the posterior edge region, which is not strongly compressed.

Scale dependence of local shearing motion in decaying turbulence generated by multiple-jet interaction

Scale dependence of local shearing motion is investigated experimentally in decaying homogeneous isotropic turbulence generated through multiple-jet interaction. The turbulent Reynolds number, based on the Taylor microscale, is between approximately 900 and 400. Velocity fields, measured using particle image velocimetry, are analysed through the triple decomposition of a low-pass filtered velocity gradient tensor, which quantifies the intensities of shear and rigid-body rotation at a given scale. These motions manifest predominantly as layer and tubular vortical structures, respectively. The scale dependence of the moments of velocity increments, associated with shear and rigid-body rotation, exhibits power-law behaviours. The scaling exponents for shear are in quantitative alignment with the anomalous scaling of the velocity structure functions, suggesting that velocity increments are influenced predominantly by shearing motion. In contrast, the exponents for rigid-body rotation are markedly smaller than those predicted by Kolmogorov scaling, reflecting the high intermittency of rigid-body rotation. The mean flow structure associated with shear at intermediate scales is investigated with conditional averages around locally intense shear regions in the filtered velocity field. The averaged flow field exhibits a shear layer structure with aspect ratio approximately 4.5, surrounded by rotating motion. The analysis at different scales reveals the existence of self-similar structures of shearing motion across various scales. The mean velocity jump across the shear layer increases with the layer thickness. This relationship is well predicted by Kolmogorov's second similarity hypothesis, which is useful in predicting the mean characteristics of shear layers across a wide range of scales.

Study of surface layer characteristics in the presence of suspended snow particles using observational data and Large-Eddy Simulation

The snowdrift is a two-phase flow consisting of air and suspended particles. In the presence of snow particles in the air, additional stability appears in the surface layer due to the density gradient. The density gradient reduces turbulence and affects the properties of the surface layer. Therefore, to describe the properties of the flow with included snow particles, additional clarifications are required. A description of the surface layer parameterization with the presence of suspended snow particles is presented in this paper. The formulation of the effect of snow particles consists in reformulation of the Obukhov turbulent length scale. The novel surface layer parameterization allows to take into account the effect of snow particles on turbulent flow and may improve the estimates of friction velocity and boundary-layer height.The parameterization was successfully tested on the observational data. Description of snow particles influence was included in the Large-Eddy Simulation (LES) model. The numerical experiments confirmed an increase in the stability of the surface layer. Mechanism of suspended particles influence on the surface layer is analogous to a thermal stabilization of the turbulent flow, in which negative buoyancy acts to reduce the turbulent kinetic energy.

The discovery of a fossil whitefly from Lower Lusatia (Germany) presents a challenge to current ideas about Baltic amber

The whiteflies (Hemiptera: Aleyrodidae) are small sternorrhynchan insects, which have the potential to cause significant economic damage to agricultural crops. There is a paucity of knowledge regarding the diversity, disparity, and evolutionary history of these insects, with classification based on the immatures, called puparia. The fossil record of whiteflies is sparse and incomplete, with the majority of fossils representing imaginal forms preserved as inclusions in fossilized resins. In this study, we present the first inclusion in succinite associated with the layers of Lower/Middle Miocene 2nd Lusatian Lignite Seam of Wanninchen in Brandenburg, Germany. The objective of the present study is to elaborate this fossil, and as a consequence, a new fossil genus and species, Pudrica christianottoi gen. et sp. nov., is described. This fossil is a representative of the subfamily Aleyrodinae, and it is the third fossil genus of this whitefly subfamily to be described. The discovery of the fossil inclusion in the succinite from the lignite deposits of Lower Lusatia challenges the current understanding of the character and conditions of formation and deposition of central and east European Paleogene fossil resins. Succinite is a fossil resin that occurs in the Eocene deposits of the Gulf of Gdańsk, belonging to the Prussian Formation, containing a glauconite-rich horizon known as the ‘Blue Earth’. Similarly, glauconite-rich deposits are present in the Lublin area of Poland, where they are associated with the occurrence of succinite. Additionally, succinite has been found in deposits in the Rovno-Zhitomir area of Ukraine, which are alluvial deposits containing glauconite and lignite layers. Succinite was also identified in Eocene strata of Spitsbergen and in Axel Heiberg Island in the Canadian Arctic. Succinite has also been discovered in early Miocene deposits in Bitterfeld, Germany, where it occurs alongside lignite deposits (the deposit actually encompasses different fossil resins, so potentially originating from different source plants). Furthermore, it has been identified in younger (Pleistocene) deposits across Europe. The autochthonous (parautochthonous) character of the lignite deposits in Lower Lusatia raises questions regarding the time range of the succinite-producing gymnosperm trees and the autochthonous or allochthonous character of the lignite layers associated fossilized resins.

Insights into the microstructure and load-dependent wear characteristics of the boride layer on Inconel 718 alloy

Dense compact boride layer was developed on the Inconel 718 alloy by powder pack-boriding process. The microstructure and load-dependent wear characteristics of the boride layers were systematically investigated. It is found that the boride layer on Inconel 718 alloy consists of a ∼2.0 μm thick nickel-rich top layer, a ∼11.3 μm thick compound layer with nanocrystalline (Ni,Fe)23B6 and (Cr,Fe)B grains, and a ∼10.9 μm thick diffusion layer with dendritic Cr2B precipitation within the matrix. The phase evolution of the boronizing layer are explainable by thermodynamic modeling of Ni-Cr-B system and the phase stability for metastable Ni-B compounds is confirmed by DFT simulation. The boride layer on Inconel 718 alloy displays good wear resistance against Si3N4 ceramic balls both at room temperature and 500 ℃. Specifically, the wear rate at room temperature is in the order of 10-6 mm3·N-1 m-1 and the wear mechanism is combined adhesive/abrasive wear and oxidation wear. A higher loading is found to promote the formation of boron oxide tribolayer on the friction ball surface, which mitigates the wear loss effectively. At elevated temperature, the wear rate is in the order of 10-4 mm3·N-1 m-1 and the wear mechanism is severe abrasion wear and oxidative wear. The employment of higher loads is beneficial to suppressing the formation of nickel oxide debris, which participates the friction process as third body and enhances wear loss.

Performance optimization of FASnI3 based perovskite solar cell through SCAPS-1D simulation

The article provides a detailed look at the fabrication of a high-performance structure for FASnI3-based perovskite solar cells (PSCs). The FTO/CeO2/FASnI3/CuI/Au structure is designed using the Solar Cell Capacitance Simulator in One Dimension (SCAPS-1D) to investigate the fabricated PSC's performance. This investigation's main objective is to improve PSCs performance by using non-traditional Hole transport layer (HTL) and Electron transport layer (ETL) materials, such as CeO2 and CuI, which have both been the subject of limited research. Moreover, the investigation seeks to determine the impact of several perovskite layer characteristics, including bandgap (Eg), electron affinity (χ), acceptor density (NA), thickness (t), and defect density (Nt). Additionally, this study also investigates the effect of various back contact work functions. Significant improvements in solar cell parameters, such as power conversion efficiency (PCE) from 22.06% to 24.87% and current density (Jsc) from 26.0274 to 30.675 mA/cm2, were observed by optimizing the device's parameters. In contrast, the fill factor (FF) and open circuit voltage (Voc) decreased their values from 86.13% to 87.10% and 0.9843 to 0.9308 V, respectively. These findings show that our designed solar cell structure performs better than those with conventionally used HTLs and ETLs. Consequently, this study highlights the potential benefits of lead-free PSCs and presents fresh opportunities for their development and use in various solar applications.

Growth characteristics of the mean shear layer in pipe bends with and without a guide vane

The growth characteristics of two identical pipe bends with and without a guide vane are investigated by means of large eddy simulation. The two pipe bends, with a radius of curvature slightly above the separation threshold, are subjected to two fully developed upstream flow conditions, with a corresponding Reynolds number of 11 700 and 24 000. A precursor computation method is employed to provide the fully developed turbulence inflow conditions for all cases. The growth of the mean shear layer in this work is characterized by the local momentum thickness, which measures the extent of momentum deficit confined under the mean shear layer. For both pipe bends, the initial growth of momentum thickness is observed in the first quarter of the bend. The onset location is almost independent of the Reynolds numbers. However, a clear Reynolds number dependence is observed in the onset magnitude, which strongly defines the growth rate thereafter. By examining the mean momentum balance in the bend section, the results show that rather than the adverse pressure gradient, the overall growth characteristics of the mean shear layer, which include the onset location and the growth rate, are better described by the balance between the centrifugal force and the radial pressure gradient. This balance manifests itself as a change in the swirling intensity of the secondary flow. The presence of guide vane significantly suppresses the swirling intensity in the bend section, leading to a noticeable reduction in the overall momentum thickness growth and the production of turbulence in the flow downstream of the bend. Further inspection also indicates that the initial mechanism leading to the suppression of separation at the inner bend is linked to the increasing dominance of the small vortices at the near-wall vicinity relative to the local adverse pressure gradient. Certain aspects pertaining to the turbulent statistics are also discussed.

Numerical reconstruction of atmospheric boundary layer seasonal turbulent wind field over a complex forest terrain

The wind characteristics of the atmospheric boundary layer (ABL) over complex forest terrains are inherently intricate, influenced by the interplay of rugged topography, seasonal climatic fluctuations, and periodic vegetation dynamics. These effects are especially evident in the near-ground wind field, which exhibits substantial seasonal variability. Conventional wind characterization methods, as outlined in current standards, often fail to accurately capture these seasonal variations, thereby complicating the reconstruction of the near-ground ABL turbulent wind field in complex forest terrains. Accordingly, we employ the narrow band synthetic random flow generation (NSRFG) technique within large eddy simulation (LES) to generate inflow turbulence representing the growing and baldness seasons in a complex forest terrain by adjusting parameter equations for seasonal adaptation and introducing new empirical equations for the turbulent spectrum. Subsequently, we verified the seasonal turbulent flow's statistical characteristics and flow structure to assess its feasibility and validity, ultimately establishing a ‘seasonal numerical wind field’ model. Finally, the seasonally modified LES-NSRFG method was applied to the numerical simulation of turbulent flow around the Commonwealth Advisory Aeronautical Research Council (CAARC) standard high-rise building model. A comprehensive comparison of wind effects was conducted for the CAARC model under varying incoming flow conditions. The results indicate that seasonal winds in a complex forest terrain significantly affect the building's vortex wake, increasing the irregularity and complexity of the structural wind pressure and base moment coefficients. Thus, the seasonal wind effect must be considered when designing wind-resistant engineering structures in forest regions moving forward.

Investigation on transition characteristics of hydrofoil boundary layer based on algebraic local-correlation-based transition modeling model

Hydrofoil shapes are used for the marine turbine blades to capture kinetic energy from water currents effectively. Predicting transitions is a critical concern when studying the hydrofoil boundary layer. This paper analyzed the transitional behavior of the boundary layer in the National Advisory Committee of Aeronautics (NACA) hydrofoil, NACA0009, with a blunt trailing edge using the Algebraic Local-Correlation-based Transition Modeling (Algebraic LCTM) model. First, through sensitivity analysis, the effects of the maximum y+ (the dimensionless distance y to the wall), grid expansion ratio, number of normal and streamlined grids, and timescale on transition prediction were studied. The results indicate that finer y+ value and appropriate grid expansion ratios can improve the accuracy of transition prediction, while the influence of timescale on the prediction results is relatively small within the range of Courant number theory values. Second, further analysis was conducted on the transition prediction performance under different Reynolds numbers. It was found that the model predictions were consistent with experimental values at low Reynolds numbers, but the predicted transition position was advanced at high Reynolds numbers, mainly because of the significant disparity in eddy viscosity coefficients within the free flow field. In the study of leading-edge roughness bands' impact on boundary layer transition for hydrofoil, the introduction of roughness significantly expedited the transition process. The Algebraic LCTM model outperformed the gamma (γ) transition model, reducing prediction errors by 5–40% for boundary layer parameters and maintaining errors between 0.005 and 4% for wake vortex shedding frequency, as opposed to the γ model's 0–23%. The results of this study provide a theoretical basis for hydrofoil design.

Effect of friction layer thickness on energy conversion efficiency of traveling wave rotary ultrasonic motor

Abstract Due to its compact size and resistance to electromagnetic interference. Applications for traveling wave rotary ultrasonic motors (TRUM) include robotic joint drives and aerospace.The motor’s energy conversion efficiency is impacted by the characteristics of the friction layer, yet the underlying mechanism influencing the efficiency remains unreported. Using the previously created finite element model, the mechanism via which the amount of thickness within the friction layer influences the motor output characteristics is examined.Analysis is done on the variations in motor loss, energy conversion efficiency, and input-output characteristics. The computation results show that when the friction layer is less than 0.4 mm, the machine’s output speed increases as the friction layer’s thickness decreases.The results of the calculation indicate that when the friction layer thickness is between 0.05 and 0.4 mm, the motor’s output torque and speed would drop. The findings indicate that the output torque and motor torque decrease as the friction layer thickness increases when it is between 0.05 and 0.4 mm. Both the viscoelastic losses and the motor’s energy conversion efficiency rise.Research shows that the friction layer thickness has a huge impact on the motor and cannot be ignored, providing a reference for the application of motors in industries such as robot joints.

Methods for Studying the Electrical Characteristics of the Epitaxial Layers of n/p-InxGa1 – xAs Solid Solutions for Large-Area Device Structures

Methods for Studying the Electrical Characteristics of the Epitaxial Layers of n/p-InxGa1 – xAs Solid Solutions for Large-Area Device Structures

Field Application of Evaluation Model for Development Effect on Horizontal Waterflooding in Thin Low-permeability Carbonate Reservoirs

Abstract Low-permeability carbonate reservoirs with layered characteristics generally exist in Middle East district. The reservoirs achieved low recovery efficiency using vertical well by depletion mode in the early stage, and low horizontal and vertical sweep efficiency by vertical waterflooding due to high permeability streak and interlayer. Some oilfields in the district has successively implemented horizontal waterflooding technology and achieved good development results. Feasible and effective report has not been provided yet on the problem that the range of recoverable reserves and recovery efficiency can be increased by horizontal waterflooding. Considering some oilfields accomplished horizontal waterflooding in quick succession and some oilfields were just developed by horizontal waterflooding, practical resolution should be recommended such as the corresponding evaluation model for enhancing recovery efficiency range of the technology. The paper put forward an evaluation model for enhancing recovery reserves and recovery efficiency of horizontal waterflooding based on production decline model and waterflooding curve model. The resolution can also provide an evaluation basis of enhancing recovery efficiency for optimization and adjustment of horizontal water flooding. Applications of these concepts are illustrated with D oilfield in Oman. Results indicated that recovery efficiency by horizontal waterflooding after natural depletion development may be increased around 25% and about 4% by the optimization and adjustment process. The evaluation model will be used effectively to predict IOR effect of the similar reservoirs in Middle East oilfields.