Effective Width Research Articles

Channel engineering for optimizing the electro‐thermal characteristics in p‐type GAA nanosheet transistors

AbstractIn this paper, we report simulation results for capacitance–voltage characteristics and temperature distribution in the cross‐section of p‐type gate‐all‐around nanosheet channel using an in‐house developed numerical simulator. The effects of material, channel width, and crystallographic orientation on electrical and thermal properties of p‐type nanosheet transistor are comprehensively investigated. The effect of channel engineering is analyzed, by evaluating density‐of‐states, hole density, current densities as well as distributions of temperature in the channel cross‐section. Finally, the thermal reliability of the device is addressed in terms of thermal resistance. The density‐of‐states and the hole density distribution at the oxide/channel interface can well explain the effective intrinsic capacitance obtained from the simulation. The better uniformity of the hole density distribution across the cross‐section of (110)/[001] channel, shows good promise for less performance fluctuation in terms of the thermal reliability issue.

Influence of Deck Butt Weld Seams on Fatigue Life of Steel Bridge Decks Pavement: Parameter Optimization

Abstract The butt weld at the connection between orthotropic steel bridge decks (OSBDs) can potentially pose a hazard to the fatigue endurance of the steel bridge deck pavement. This study aims to optimize the parameters of the butt weld seam using finite element (FE) analysis. The optimized parameters will provide valuable guidance for the design of pavements with a focus on antifatigue properties. Initially, the dynamic modulus of the epoxy asphalt mixture (EAM) was determined through laboratory experimentation at various frequencies and temperatures. These material parameters were then used to compute the pavement’s fatigue life. Additionally, a well-established FE model was employed to analyze the deformation and fatigue life of the pavement structure. The validity of the model was verified by the theoretical calculation results. Various factors were considered, including vehicle velocities, pavement temperatures, and weld seam misalignments as well as weld seam dimensions such as height and width. The analysis was conducted using a three-dimensional steel bridge model. The results showed that decreasing pavement temperature, weld seam height, and misalignment led to an increase in pavement fatigue life. Conversely, reducing the weld seam width resulted in a decrease in fatigue life. Furthermore, the study investigated the coupling effect of different weld seam heights and widths on the fatigue life of the pavement. Contour figures were used to establish the parameter relationship formula for weld seam height and width. These findings are significant for pavement and deck designers because they enhance the understanding of the sensitivity of weld seams as design variables affecting the fatigue characteristics of pavement structures. Moreover, special attention should be given to the impact of welding parameters on the fatigue design of steel bridge deck pavement under high-temperature conditions of pavement structures.

The Road’s Level of Service at Kawi Road, Malang Regency

A region’s ability to expand and flourish depends heavily on its road system. Roads that are smooth and effective facilitate communication between different locations, the movement of people, and the transit of commodities. Thus, people movement within a region is greatly impacted by the quality of road service. One of the principal thoroughfares in Malang Regency is Kawi Road, which has two two-way lanes without a median and an effective road width of eight meters. It is a primary collector hierarchy (2/2 UD). There is a lot of traffic on Kawi Road since it connects two local activity hubs, Blitar and Lumajang, and acts as a national road. This study’s main objective is to characterize Kawi Road in Kepanjen District, Malang Regency, with regard to its attractiveness and generation of land use, performance, and modeling. In compliance with the 2014 Indonesian Road Capacity Guidelines, the following research methodologies were used: road capacity analysis, saturation degree analysis, multiple linear regression analysis, and road service level analysis. The research makes use of field observation data. According to calculations, Kawi Road can handle 2826.63 passenger car units per hour. Its peak performance was reached between 15:00 and 16:00, or 0.87 (LOS E).

Flow over a radiating multi-filamentous structure with various opening angles: From disk-like to cone-like shape

Flow over a radiating multi-filamentous structure with various opening angles has been investigated numerically at low and moderate Reynolds numbers. The opening angle, as the major geometric parameter for investigation, varies from 180° to 40° and the overall shape changes from disk-like to cone-like. The overall model drag decreases monotonously as the magnitude of the opening angle decreases. The opening angle effects on the drag-enhancement are then investigated in terms of the velocity distributions, the structures of the recirculation region, and the pressure distributions. As the Reynolds number increases, the wake structure loses its steadiness and the optimal opening angle is found to be approximately 60° when the critical Reynolds number for a steady recirculation structure becomes maximum. The opening angle effects on the wake steadiness in terms of the intensity of the shear layer are investigated as well. On the one hand, the exit velocity—a quantitative indication of the rate of the base bleed—decreases with the decreasing of the opening angle, which promotes wake unsteadiness. This phenomenon can be attributed to the effective gap width between adjacent filaments and the intensity of the virtual barrier from both macro- and micro-perspectives. On the other hand, a small opening angle decreases the thickness of shear layer and thus the unsteadiness is suppressed. These two effects compete and the balance is reached when the opening angle is near 60°.

ONE-WAY SLABS IN TRANSITION BETWEEN ONE-WAY SHEAR AND PUNCHING: EXPERIMENTS AND RECENT INSIGHTS FOR EVALUATION

Bridge deck slabs are members on which one-way reinforced concrete slabs are found frequently loaded by concentrated loads. Although the one-way shear failure mechanism has gathered more attention in the past years, both one-way shear and two-way shear mechanisms may be critical for such loading conditions. This paper addressed the ultimate capacity of thin one-way reinforced concrete slabs subjected to concentrated loads and yielding of the flexural reinforcement. In practice, the test setup studied was devised to represent short-span rural bridges frequently found in Brazil. The experimental program included 12 tests performed on 6 slabs applying the concentrated loads at varied positions. All tests started to fail by punching shear. Nevertheless, both one-way shear and punching shear cracks were observed at ultimate states after shear redistribution. The reinforcement yielding followed by excessive flexural cracking hampered the arching action activation for loads closer to the support. The comparison of experimental and calculated resistances using standard code-based expressions suggests that improvements in unitary shear capacity could be supported as a result of slabs' transverse load distribution capacity. Alternatively, increasing the effective shear width can help estimate one-way shear capacity for loads near to the support.

Justification the surface mining system parameters of amber pits with semi-mobile beneficiation plants

Research is aimed at establishing the dependence of the semi-mobile beneficiation plant productivity on the face width of the excavator at the developing amber deposits. Analytical research methods were used at the development of the methodology to determine the working time of excavator, taking into account the time for moving the enrichment plant. Appropriate calculation methods are relevant for determining the required amount of technical equipment that ensures the mining operation. The efficient parameters of the face width during the excavation of mining mass have been established, depending on the parameters of the excavator boom, taking into account its replacement. It was determined that the duration of the working cycle of working out the block with the corresponding face width of the pit is based on the time of loading and moving the semi-mobile beneficiation plant, as well as the time for reexcavation. The effective width of the working pit face was calculated with the appropriate choice of the excavator boom. The established parameters of the face width of the pit on the mining bench with the loading of mining mass to the semi-mobile concentrator were implemented in the pit at the development of the Galbin-24 amber deposit.

Coil Parameter Analysis for Inductively Coupled Wireless Charging for Electric Vehicles

Wireless charging (WC) has gained popularity for the charging of electric vehicles in recent years of research, particularly dynamic wireless charging systems (DWCSs). Among the different topologies of DWCSs, this paper focuses on an inductively coupled wireless charging system (ICWCS). In this ICWCS, double-D (DD) coils create horizontal and vertical flux components between different pad configurations, which show optimal features in contrast to circular pad coils. In this work, the three-dimensional (3D) finite element technique (FEM) is used to establish the proposed design to observe the coupling coefficient, while the system design’s performance is evaluated using a circuit simulator. In the simulation, the proposed DD coil configuration is used for both the transmitter and receiver sides. It provides the maximum coupling coefficient and efficiency at perfect alignment when using an in-between air gap of 166 mm and six I-type ferrite bars on the transmitter side and five I-type ferrite bars on the receiver side. The coupling coefficient and system parameters, such as power and efficiency, are considered for different misalignments in the proposed configuration. The results of this work satisfy the Society of Automotive Engineers (SAE) J2954 Class 3 criteria. The best results obtained are on account of optimizing the ferrite core, which is achieved by varying its length and width. While varying the ferrite core’s dimensions, 0.2451, as the optimal k value, is obtained at the effective width and length of 57.5 mm and 400 mm, respectively. The simulation results of the Ansys Maxwell 3D software prove the feasibility of the proposed structure.

Numerical study of transient supercooling performance and thermal stress analysis of segmented annular thermoelectric cooler

A multiphysics-coupled numerical simulation of a segmental annular thermoelectric cooler (SATEC) was performed using a three-dimensional finite element method. A coupling model of the temperature, stress, and electric fields was established based on the three-dimensional transient states. Moreover, the effects of different pulse width (τ), pulse current amplitude (Pa), pulse current shape parameter (m), heat transfer coefficient (h), angle (θ), and length (H) of the thermoelectric leg on the SATEC transient properties and von Mises stress were studied. The results show that τ and Pa are the key influencing factors of SATEC. The larger the h, the more optimized the heat transfer effect of the SATEC hot end. However, when h increased to a certain value, the changes in the transient performance were insignificant. The optimal pulse can be achieved when the input pulse current Iop = 6.47 A and pulse width τ = 20 s. When the length of the thermoelectric leg H4 was 3 mm and the thermoelectric leg angle θ2 was 7°, the performance of SATEC was optimal, with Tc,min being 249.57 K, Tc,max being 279.50 K, thold being 5.5 s, and the maximum von Mises stress being 37.48 MPa. The results show that different supercooling indices and von Mises stresses could be obtained for different pulse current shapes. Geometric optimization of SATEC can improve the cooling performance and reduce the von Mises stress, thereby providing a theoretical reference for practical engineering applications and thermoelectric cooling research.

High-Power Mid-Infrared Quantum Cascade Laser with Large Emitter Width

High-power quantum cascade lasers (QCLs) have a wide application prospect. In this paper, a high-power high-beam-quality device with a large ridge width is demonstrated. The effect of different ridge widths on mode loss was studied, and the results showed that the mode loss decreased as the ridge width increased. Furthermore, as the width of the ridge increased, the temperature of the active region rose. In the experiment, the wafers were grown by metal–organic chemical vapor deposition (MOCVD), and the ridge width of the device was controlled by wet etching. A laser with a ridge width of 15 µm and a length of 5 mm achieved an output of 2.2 W under 288 K continuous wave (CW) operation, with a maximum slow-axis divergence angle of 27.2° and a device wavelength of 5 μm. The research results of this article promote the industrial production of base transverse mode QCL.

Development of a foam-filled steel web sandwich panel for the rehabilitation of timber floors

Lightweight sandwich panels offer a prominent solution for the rehabilitation of timber floors. This paper addresses the development of a solution capable of continuous production for a foam-filled steel web sandwich panel for floor rehabilitation. The newly designed flooring solution is tested in full-scale quasi-static flexural campaigns. The tests validate the analytical design's compliance with Ultimate limit state (ULS) and Serviceability limit state (SLS) requirements. Furthermore, the flexural behaviour is compared with analytical predictions for thin-walled members according to the effective width method, described in Eurocode 3. Different effective cross-section design assumptions are assessed to allow an accurate prediction of the panel's response.

Optimizing non-Newtonian fluids for impact protection of laminates

Non-Newtonian fluids can be used for the protection of flexible laminates. Understanding the coupling between the flow of the protecting fluid and the deformation of the protected solids is necessary in order to optimize this functionality. We present a scaling analysis of the problem based on a single coupling variable, the effective width of a squeeze flow between flat rigid plates, and predict that impact protection for laminates is optimized by using shear-thinning, and not shear-thickening, fluids. The prediction is verified experimentally by measuring the velocity and pressure in impact experiments. Our scaling analysis should be generically applicable for non-Newtonian fluid-solid interactions in diverse applications.

Development of Capacity Estimation Models for Multi-lane Roads under Heterogeneous Traffic Conditions

The objective of this study is to develop capacity models to estimate the traffic carrying capacity of multi-lane roads with heterogeneous traffic flows. Since capacity is an important parameter in traffic engineering studies, it is vital that it is accurately estimated. Most of the current capacity estimation methodologies available are developed based on homogeneous traffic flows and hence not conducive for use in heterogeneous traffic conditions observed in Sri Lanka. Therefore, this study is done to fulfill the requirement of a capacity estimation model for this purpose. Fifty midblock sections were surveyed using manual flow data collection methods and a novel Google Application Program Interface (API) based method for speed data collection. Based on the collected data, capacity values were developed following the fundamentals of traffic flow. Regression models were built to estimate four-lane and six-lane capacity values based on roadway characteristics such as effective lane width, access point density, median type, and built environment condition. Separate models were developed because the impact these characteristics have on four-lane and six-lane roads are different. The models showed good fit with R2 values of 0.81 and 0.86 for four-lane and six-lane roads, respectively. The base capacity value of a four-lane urban road was estimated to be 2044 pcu/h/l and for a six-lane sub-urban road section 2108 pcu/h/l. The outcomes of this study can be used to develop capacity guidelines in countries with heterogeneous traffic conditions for capacity estimation.

Investigating the wave attenuation capabilities of rectangular pile head breakwater: A physical modelling approach

The study provides a comprehensive examination of single row Rectangular Pile Head Breakwaters (RPHB), encompassing both non-perforated and perforated variations. In the non-perforated RPHB category, the investigation delves into the effects of pile head height and width, and wave climate. For perforated RPHB structures, the study analyses the influence of percentage of perforations, perforation size, and depth of water. Further, the research includes a comparative assessment between non-perforated and perforated RPHB structures. Additionally, the research conducts a comparative analysis with similar structures. In the case of non-perforated RPHB, the configuration with relative pile head diameter (D/d) of 2.4 and relative pile head height (Y/Hmax) of 1.5 stood out as the most effective model. Similarly, the perforated RPHB demonstrated its maximum wave attenuation potential with percentage of perforations (P) of 24% with relative size of perforations (S/D) of 0.25. This optimal configuration achieved a minimal wave transmission coefficient (Kt) of 0.53, reflection coefficient (Kr) of 0.33, and energy dissipation coefficient (Kd) of 0.79 at a relative water depth (h/H) 0.865. Notably, the introduction of perforations on the RPHB structure led to an improvement in wave attenuation performance by 4–8%, resulting in lower reflection and higher energy dissipation. Comparatively, the RPHB structure outperformed the Enlarged (cylindrical) Pile Head Breakwater (EPHB) and Conical Pile Head Breakwater (CPHB) structures in terms of wave attenuation, exhibiting higher reflection and superior energy dissipation characteristics. The consistent outcome of these investigations reveals that the RPHB exhibits superior hydrodynamic performance characteristics and design suitability, making it a promising choice for breakwater applications.

Dual External Electron Injection Barrier Layers Enable High‐Performance Near‐Infrared Organic Photodetectors Realizing Real‐Time Heart Rate Monitoring

AbstractNear‐infrared organic photodetectors (NIR‐OPDs) play important roles in medical monitoring, bio‐imaging and night vision, etc. Among them, bulk heterojunction (BHJ)‐based photodiode type NIR‐OPDs exhibit extraordinary characteristics in photoresponse and photosensitivity. However, their dark current density (Jd) often increases severely as the bias voltage increases, which seriously reduces detection sensitivity for NIR light. Here, a novel structure of dual external electron injection barrier layers (DEBLs) composed of “m‐MTDATA/DPEPO:HAT‐CN” is proposed to overcome this challenge. For DEBLs, a barrier is established with high injection barrier and long effective injection barrier width to prevent external electrons injection under bias voltage for suppressing Jd (4.22 × 10−8 A cm−2 better than 1.47 × 10−5 A cm−2 of the traditional device at −2 V). More importantly, photo‐generated carriers have almost no loss through DEBLs. Therefore, high and stable detectivity (D*) over 1013 Jones are realized under 850 nm from 0 V to nearly −1 V and even far over 1012 Jones at −2 V. More strikingly, the structure of DEBLs is proven to be effective and universal in NIR‐OPDs and the device based on it successfully realize the real‐time heart rate monitoring of various human states, which exhibits great potential in human health monitoring.

Layer thickness and path width setting in 3D printing of pre-impregnated continuous carbon, glass fibers and their hybrid composites

3D printing has been successfully applied in the manufacturing of variety continuous fiber and hybrid fiber reinforced composites. The process parameters have a significant impact on the overall performance of the printed parts. This paper investigates the effects of layer thickness and path width on the bending strength and surface roughness of printed pre-impregnated continuous carbon fiber, glass fiber, and their hybrid composites. Additionally, the microstructures of the fracture surfaces of the printed parts were analyzed. The results indicate that the optimal combination of bending strength and surface accuracy for printed single fiber parts is achieved when the printing layer thickness is set to 30%–40% of the fiber filament diameters. Furthermore, finely matched path width settings significantly improve the surface accuracy of printed hybrid carbon/glass fiber composites. Notably, the bending strength of printed interlayer hybrid fiber composite specimens increased by 35% compared to the specimens uniformly set according to the carbon fiber path width.

A new exploration on passive control of transonic flow over a backward-facing step

PurposeThis paper aims to study passive control techniques for transonic flow over a backward-facing step (BFS) using square-lobed trailing edges. The study investigates the efficacy of upward and downward lobe patterns, different lobe widths and deflection angles on flow separation, aiming for a deeper understanding of the flow physics behind the passive flow control system.Design/methodology/approachLarge Eddy Simulation and Reynolds-averaged Navier–Stokes were used to evaluate the results of the study. The research explores the impact of upward and downward patterns of lobes on flow separation through the effects of different lobe widths and deflection angles. Numerical methods are used to analyse the behaviour of transonic flow over BFS and compared it to existing experimental results.FindingsThe square-lobed trailing edges significantly enhance the reduction of mean reattachment length by up to 80%. At Ma = 0.8, the up-downward configuration demonstrates increased effectiveness in reducing the root mean square of pressure fluctuations at a proximity of 5-step height in the wake region, with a reduction of 50%, while the flat-downward configuration proves to be more efficient in reducing the root mean square of pressure fluctuations at a proximity of 1-step height in the near wake region, achieving a reduction of 71%. Furthermore, the study shows that the up-downward configuration triggers early spanwise velocity fluctuations, whereas the standalone flat-downward configuration displays less intense crosswise velocity fluctuations within the wake region.Practical implicationsThe findings demonstrate the effectiveness of square-lobed trailing edges as passive control techniques, showing significant implications for improving efficiency, performance and safety of the design in aerospace and industrial systems.Originality/valueThis paper demonstrates that the square-lobed trailing edges are effective in reducing the mean reattachment length and pressure fluctuations in transonic conditions. The study evaluates the efficacy of different configurations, deflection angles and lobe widths on flow and provides insights into the flow physics of passive flow control systems.

Diagnostic and prognostic value of PCT and RDW in premature infants with septicemia.

It aims to study the diagnostic effect of procalcitonin (PCT) and red blood cell distribution width (RDW) in premature septicemia (PS), and to analyze the prognostic evaluation value of PCT and RDW in PS. Ninety eight septicemia premature infants (SPI) who visited the neonatal intensive care unit of our hospital from June 2019 to July 2021 were selected and met the criteria. Based on the patient's condition and the neonatal shock score, they were separated into a severe group (SG) and a mild group (MG). There were 43 children and 55 children in the 2 groups, respectively. According to the survival status of SPI after 3 days of treatment, they were divided into a death group and a SG. It detected and analyzed the peripheral venous blood of SPI before treatment (BT) and after treatment (AT), and observed the changes of PCT and RDW. The comparison of general data between severe and mild SPI and their mothers did not have statistical significance (P > .05). The PCT of the SG was higher than that of the MG BT, on the 1st day and the 3rd day AT; The PCT BT and AT in both groups ranged from high to low on the 1st day and the 3rd day AT and BT (P < .05). The RDW in the SG were higher than those in the MG, and the RDW BT and AT in both groups were the highest on the 1st day AT; The RDW BT in the MG was higher than on the 3rd day AT, while the RDW BT in the SG was lower than on the 3rd day AT (P < .05). The optimal cutoff values for PCT on the 1st and 3rd day AT were 40.594ng/ml and 64.854ng/ml, respectively, with sensitivity of 100.0% and 100.0%, and specificity of 73.2% and 87.1% (P < .05). The optimal cutoff values for RDW on the 1st and 3rd day AT were 16.649% and 18.449%, respectively, with sensitivity of 100.0% and 100.0%, and specificity of 68.5% and 91.8% (P < .05). Monitoring the changes in PCT and RDW can promote the early diagnosis of PS and their prognosis evaluation.

Effect of width and slope of large cross-section tunnel on ceiling smoke temperature under natural ventilation

ABSTRACT When a fire occurs in a large cross-section tunnel with slope, the distribution characteristic of ceiling smoke temperature illustrates special laws under the effect of chimney effect, the thermal radiation feedback, and the air entrance limit from walls. A series of numerical simulations are conducted through FDS simulation software based on the actual size of highway tunnel. The influence of large cross-section tunnel width and slope on ceiling smoke temperature when fire occurs are discussed. The research results show that (1) as the tunnel slope increases from 5° to 20°, the distance between the maximum ceiling smoke temperature point and the fire source is 0.5 m, 1 m, 1.7 m, 2.4 m, respectively, and the distance between the ceiling impact point and the fire source is 1 m, 1.8 m, 2.3 m, 3 m, respectively. As the tunnel width increases from 10 m to 20 m, the distance between maximum ceiling smoke temperature point and fire source increases 0.9 m, 1.1 m, 1.3 m, 1.8 m, 2.5 m, and 2.6 m. (2) The prediction formula of maximum ceiling smoke temperature is modified, and a dimensionless relationship among the maximum ceiling smoke temperature and tunnel slope and tunnel width is established. (3) The formula of longitudinal ceiling smoke temperature distribution is modified, and the relationship among tunnel slope, tunnel width, tunnel height, and longitudinal ceiling smoke temperature distribution is established. The research conclusions can provide a theoretical basis for fire prevention design, smoke control and evacuation of this kind of large cross-section tunnel fire.

Ion transport through short nanopores modulated by charged exterior surfaces.

Short nanopores find extensive applications, capitalizing on their high throughput and detection resolution. Ionic behaviors through long nanopores are mainly determined by charged inner-pore walls. When pore lengths decrease to sub-200nm, charged exterior surfaces provide considerable modulation to ion current. We find that the charge status of inner-pore walls affects the modulation of ion current from charged exterior surfaces. For 50-nm-long nanopores with neutral inner-pore walls, the charged exterior surfaces on the voltage (surfaceV) and ground (surfaceG) sides enhance and inhibit the ion transport by forming ion enrichment and depletion zones inside nanopores, respectively. For nanopores with both charged inner-pore and exterior surfaces, continuous electric double layers enhance the ion transport through nanopores significantly. The charged surfaceV results in higher ion current by simultaneously weakening the ion depletion at pore entrances and enhancing the intra-pore ion enrichment. The charged surfaceG expedites the exit of ions from nanopores, resulting in a decrease in ion enrichment at pore exits. Through adjustment in the width of charged-ring regions near pore boundaries, the effective charged width of the charged exterior is explored at ∼20nm. Our results may provide a theoretical guide for further optimizing the performance of nanopore-based applications, such as seawater desalination, biosensing, and osmotic energy conversion.

Band gap characteristics of new composite multiple locally resonant phononic crystal metamaterial

Locally resonant phononic crystal (LRPC) exhibit elastic wave band gap characteristics within a specific low-frequency range, but their band gap width is relatively narrow, which has certain limitations in practical engineering applications. In order to open a lower frequency band gap and broaden the band gap range, this paper proposes a new composite multiple locally resonant phononic crystal (CMLRPC). Firstly, the band structure of the CMLRPC is calculated by using the finite element method, and then the formation mechanism of the band gap of the CMLRPC is studied by analyzing its vibration mode, and the band gap width is expanded by adjusting the size of the single primitive cell in the supercell model of the CMLRPC. Secondly, an equivalent mass-spring system model for CMLRPC is established to calculate the starting frequency and cut-off frequency of the band gap, and the calculated results are in good agreement with the finite element calculation. Finally, the frequency response function of the CMLRPC is calculated and its attenuation characteristics are analyzed. Within the band gap frequency range, the attenuation values of the CMLRPC are mostly above 20 dB, indicating a good attenuation effect. Compared with traditional LRPC, this new CMLRPC opens multiple band gaps in the frequency range of 200 Hz, with a wider band gap width and better attenuation effect. In addition, considering both the contact between single primitive cell and the adjustment of their spacing in the supercell model of the CMLRPC, lower and wider band gap can be obtained. The research results of this paper provide a new design idea and method for obtaining low-frequency band gap in LRPC, and can provide reference for the design of vibration reduction and isolation structures in the field of low-frequency vibration control.