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Thermal protective performance of protective clothing is greatly affected by structural parameters of fabric, air gap, and orientation of testing. This paper used Box-Behnken design experimental design to see the influence of pick density of shell (outer) layer, air gap, and orientation of test on thermal protective performance in terms of protection time. The testing was done at constant radiant heat flux. Thermal protective performance was measured in terms of second degree burn time using Stoll's curve. The model showed F value of 72.98 and p-value 0.0001 which shows that model was significant. It was also found that there was significant effect of pick density, air gap, and orientation angle on thermal protective performance. There was positive effect of pick density and air gap but negative effect of orientation angle. This was also observed that effect of pick density was more when air gap increases. The study can help in development of thermal protective clothing for different parts of body. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to determine the effect of clothing fabrics, sizes and air ventilation rate on the volume and thickness of the air gap under the air ventilation garments (AVGs). Design/methodology/approach: The geometric models of the human body and clothing were obtained by using a 3D body scanner. Then the distribution of the volume and thickness of the air gap for four clothing fabrics and three air ventilation rates (0L/S, 12L/S and 20L/S) were calculated by Geomagic software. Finally, a more suitable fabric was selected from the analysis to compare the distribution of the air gap entrapped for four clothing sizes (S, M, L and XL) and the three air ventilation rates. Findings: The results show that the influence of air ventilation rate on the air gap volume and thickness is more obvious than that of the clothing fabrics and sizes. The higher is the air ventilation rate, the thicker is the air gap entrapped, and more evenly distributed is the air gap. It can be seen that the thickness of the air gap in the chest does not change significantly with the changes of the air ventilation rates, clothing fabrics and sizes, while the air gap in the waist is affected significantly. Originality/value: This research provides a better understanding of the distribution of the air gap entrapped in ventilated garments, which can help in designing the optimal air gap dimensions and thus provide a basis and a reference for the design of the AVGs. [ABSTRACT FROM AUTHOR]

Standard log transmission protocols do not offer a robust way of segregating the log network from potential threats. A secure log transmission system and the realization of a data diode using affordable components are proposed. Unidirectional data flow prevents unauthorized access and eavesdropping, ensuring the integrity and confidentiality of sensitive log data. The system uses an encryption protocol that requires that the upstream and the downstream of the data diode are perfectly synchronized, mitigating replay attacks. It has been shown that message amplification can mitigate UDP packet loss, but this is only required when the data diode traffic is congested. The implementation of the encryption algorithm is suitable for resource-constrained devices and it has been shown to produce random-looking output even on a reduced number of rounds when compared to the parent cipher. Several improvements have been made to the original encryption algorithm for which an actual implementation was missing. Free software and datasets have been made available to reproduce the results. The complete solution is easy to reproduce in order to secure the segregation of a log network inside any scenario where logging is required by the law and log tampering must be prevented. [ABSTRACT FROM AUTHOR]

• Numerical modeling of an integrated refrigerated container. • Different cargo pallet arrangements and cargo packaging boxes are tested. • Airflow short-circuiting has both positive and negative effects on cargo cooling. • Improving vertical airflow in cargo pallets enhances cargo cooling than air gaps. Improving the performance of a refrigerated container is crucial in effectively preserving thermal-sensitive cargo. The combined effect of vertical airflow resistance and airflow short-circuiting in air gaps play a vital role in cargo cooling. This study numerically investigates the effects of cargo vertical airflow resistance and air gaps between cargo pallets using two commonly used apple packaging boxes, each stacked in six different cargo pallet arrangements. A heat transfer enhanced refrigerated container design and a numerical model developed from the present authors' previous studies are used. The numerical model uses the porous medium model to incorporate the refrigeration unit and cargo within the refrigerated container. Additionally, the numerical domain includes the T-bar floor in the refrigerated container. Initially, the airflow characteristics based on vertical airflow resistance and air gaps are discussed. Then, the corresponding effects on cargo cooling are addressed. Results show that the air gaps between the cargo pallets have positive and negative effects on cargo cooling. In cargos with lower vertical airflow resistance, an increase in air gaps leads to reduced cargo cooling and elevated temperature non-uniformity. Conversely, cargos with higher vertical airflow resistance experience increased cooling rates and reduced temperature non-uniformity with the increase in air gaps. However, avoiding airflow short-circuiting through the air gaps between the cargo pallets and improving the vertical airflow inside the cargo pallets can provide better cargo cooling, which outweighs the positive cooling effect of the air gap. [ABSTRACT FROM AUTHOR]

This paper developed a method for more accurate permittivity extraction of high-loss materials using the waveguide method to reduce the effect of the air gap. This method improves the Baker-Jarvis algorithm. It makes the errors of S-parameters caused by the air gap compensated by a correction factor β of the form: (S21 + S12) + β(S11 + S22). In our study, the correction results of β for materials on different frequencies and air gap sizes are quantitatively investigated. Furthermore, we propose a method to obtain an optimal frequency-independent β for different materials. A typical high-loss BeO-SiC ceramic commonly used in vacuum electron tubes is analyzed and discussed in detail. It shows that compared to traditionally utilizing only S21 (β = 0), adopting an optimal β can reduce the average errors of the complex permittivity from 17.7% to 7.9% with a 0.10 mm air gap. The proposed method is verified by measurements of unshaved and shaved samples. [ABSTRACT FROM AUTHOR]

This research investigates the performance of ABS P400 parts under compressive loading. These ABS P400 parts are fabricated by fused deposition modeling (FDM) process using omnidirectional printing. The effects of three critical parameters, raster angle (A), air gap (B), and raster width (C), each at three different levels, were analyzed on three different performance measures, i.e. total deformation up to failure (TD) measured in %, maximum energy (ME) in MJ/m3 and break energy (BE) in MJ/m3. Results of experimentations were analyzed using analysis of variance (ANOVA), perturbation curve and 3D surface plots. The research established the anisotropic nature, durability and less brittleness of the FDM fabricated ABSP400 part, which leads to lower strength and also influence the energy absorbing behavior while deformation under compression. Complex relationships were exhibited between the chosen parameters and studied measures. It was also observed that TD is noticeable due to less brittleness of ABS P400 however, TD and BE vary in a contradictory fashion with changes in process parameters. The models were validated using normality plots. Multi-objective optimization was done using the desirability approach to determine the optimal combination of FDM process parameters for optimum responses. The desirability result showed that the optimized input parameter is A=60∘,B=0.002mm, and C=0.477mm which yield maximized optimum responses as TD=47.94%, ME=1.6×106MJ/m3, and BE=2.13×107MJ/m3. The work not only reflects the effect of three FDM parameters on the total deformation up to failure (TD in %) but, in addition, energy absorption behavior of FDM parts under compression is also investigated. The study on the behavior of energy at ultimate stress or ultimate load and breaking stress or breaking load were rarely investigated in earlier research which reflects the novelty of our research. [ABSTRACT FROM AUTHOR]

The building sector represents a significant proportion of the world's energy consumption and greenhouse gas emissions. One of the possible contributions to reducing this problem is to improve the energy performance of buildings by acting on their envelope and systems. Consequently, the aim of this work is to develop an experimental and numerical methods for characterizing the thermal performance of a concrete masonry hollow wall, in order to propose a new configuration that can be used to improve its thermal performance. First, this study focuses on the thermal performance of different wall configurations. Then, each case studied at wall scale, was modeled, and simulated in 3D using COMSOL Multiphysics® software under the same conditions, properties and dimensions as the one tested experimentally. Finally, this analysis was applied to a real building in Lebanon, consisting of hollow concrete masonry walls, to study its energy and thermal requirements. The conclusions showed that the numerical and experimental results proposed for the hollow masonry block wall confirm a good match. This validates the value of this method in the construction sector by proposing new methods for improving its thermal and energy performance. [ABSTRACT FROM AUTHOR]

In the paper proposed half-differential capacitive sensor for measuring the air gap between the stator core boring and the rotor poles in a powerful hydro-generator. The main parts of the sensor are a variable working capacitor and a constant working capacitor, the electrode geometry of which is similar to the ge-ometry of the electrodes of the variable capacitor. Sensor construction is a multilayer printed circuit board with conductive and dielectric insulating layers. The variable capacitor and the constant capacitor are formed by systems of strip parallel coplanar high-potential and low-potential electrodes of equal width, between which the grounded electrodes are placed. The ratio between the width of the high-potential, low-potential and grounded electrodes in the working capacitors is chosen depending on the value of the measured nominal air gap. The length of the high-potential and low-potential electrodes of the perma-nent capacitor is determined by the size of the gap in the dielectric layer, which determines the capacity of the specified capacitor. The electric capacity is measured between the system of parallel-connected high-potential electrodes and the system of parallel-connected low-potential electrodes of the working variable capacitor, which functionally depends on the size of the air gap. The electrical capacity between the sys-tem of parallel-connected high-potential electrodes and the system of parallel-connected low-potential electrodes of a constant capacitor is measured, which functionally depends on the size of the air gap, which is determined by the thickness of the dielectric layer with a cutout in the printed circuit board. To eliminate the influence of the external environment, the ratio of the capacities of the constant and varia-ble capacitor used to determine the informative parameter. Analytical and graphical dependences for the conversion function of the sensor intended for use on a capsule hydrogen generator of the SGK538/160-70M type have been determined. Compared to analogues, the sensor has a higher measurement accuracy due to half-differential measurement scheme used, which eliminates the influence of the external envi-ronment. A sensor or a system of sensors can be used as a separate meter or as a component of monitor-ing and diagnostic systems. Ref. 14. Fig. 4. [ABSTRACT FROM AUTHOR]

The need for fresh water production is especially high in hot dry climates without any sources of drinking water but with an abundance of sea and underground water. The solution is water desalination with efficient solar-powered water treatment plants. This article proposes a new modification of a basin made of thin-finned corrugation with 43°-angle-inclined sides, equal to the region’s latitude, which provide strong heating. The experiments were carried out in the hot climate of Aktau city (43°49′ N, 51°1′ E). The study’s outcomes can be useful for regions with drinking water scarcity. To define the level of the corrugated basin’s efficiency, two versions (SS-1, SS-2) of experiments were carried out on a two-slope distiller, complete with two basins. In SS-1, basin-2 was heated by air. By 15:00, basin-2 had heated up to 98.5 °C, and the acrylic cover above had heated up to 101.6 °C, which led to its “deformation”. By 12.00 p.m., the temperature differentials between the glass (40.7 °C), the air–water mixture (57.3 °C), and basin-1 (61.1 °C) were 16.6 °C and 20.4 °C. This resulted from the wind speed increasing up to 5.9 m/s. The large temperature differential contributed to the condensate yield increasing from 0.128 kg at 11 o’clock to 0.293 kg at 12 o’clock. The throughput capability of basin-1 per day was equal to 2.094 kg. Basin-2’s input to the performance in SS-1 was only the thermal effect. In SS-2, basin-2 was used as a regular basin. The plexiglass temperature was lower than the temperatures of the water and basin-2. The temperature differential between the glass and air–water mixture at 10:00 a.m. was 20 °C; at 12:00 p.m. it was 30.6 °C; and a value of 30.6 °C was recorded at 3:00 p.m. The thermal differential between the glass and the air-water mixture provided the highest condensate yield of 1.114 kg at 3.00 p.m. The condensate yield from the basins in SS-2 was 8.72 kg, including 3.5 kg from basin-1, which is 1.7 times more than from basin-1 in SS-1. The experimental results are consistent with the equations coming from the models of Clark J.A. and Dunkle R.V. Tcondensation ≠ Tevaporation is an irreversible process. When the basins are heated, the heat is consumed; when the glass cools down, the heat is given off. Heat losses are minimized due to the “gap” and positive energy is provided. The still’s throughput capability can be made larger by increasing the basin’s area, reducing the water layer thickness, and regulating the flowrate of the desalinated water.

Permanent Magnet Synchronous Motor (PMSM) applications include electric vehicles, industrial pumps, wind turbines, aerospace technology, and many others. In this study, cogging torque is the central aspect of the discussion, which is the motor model, the thickness of the permanent magnet rotor, and the air gap in the electric motor influence. The Taguchi method uses parameter levels on the motor, which are divided into 16 types of orthogonal arrays, where the process is carried out twice in iterations. The first stage of simulation testing was to produce the primary model where number 4 (A1B4 series) was obtained as the most optimal motor model with a cogging torque of 1.56 Nm and an air gap flux density of 768 mTesla (mili tesla). Then the second test was to modify several parts of the motor with the following 16 orthogonal array types, which produced number 8 (A2B4 series) with a cogging torque of 1.08 Nm and an air gap flux density of 733 mTesla. One of the parameters apart from the cogging torque must be maintained is the air gap flux density. This variable affects the permeability of the motor so that later it will affect the amount of material used and the production costs of electric motors. The final result is a model that produces the lowest cogging torque while maintaining other parameters on the motor.

Anti-plane shear wave propagation in a functionally graded piezoelectric substrate and a piezoelectric substrate guided by a slit is analyzed theoretically. The equations of motion are taken from the linear theory of piezoelectricity for polarized ceramics. The dispersion relation is obtained by applying appropriate boundary conditions on the derived solutions. PZT-5 and ZnO are taken as numerical examples to manifest the effect of different material parameters (gradient factor, slit width etc.) graphically on the phase and group velocity of the considered wave. $ \textrm{LiI}{\textrm{O}_\textrm{3}} $ LiI O 3 and $ \textrm{BaTi}{\textrm{O}_\textrm{3}} $ BaTi O 3 materials are taken separately to compare the results. Also, graphs are plotted for different modes of the wave as well as for different frequency ranges and for the case when slit is absent. As a special case, it is remarked that the present study has resemblance with one of the existing works. The highlights of the study are to characterize the anti-plane wave propagation within a functionally graded piezoelectric substrate/gap/piezoelectric substrate coupled structure, to show the effect of different parameters, modes, frequency, etc. on the velocity profile of the considered wave and to show the effect of gap layer. The outcomes of this study may be used to enhance the sensitivity of acoustic wave devices and sensors. [ABSTRACT FROM AUTHOR]

The need for fresh water production is especially high in hot dry climates without any sources of drinking water but with an abundance of sea and underground water. The solution is water desalination with efficient solar-powered water treatment plants. This article proposes a new modification of a basin made of thin-finned corrugation with 43°-angle-inclined sides, equal to the region's latitude, which provide strong heating. The experiments were carried out in the hot climate of Aktau city (43°49′ N, 51°1′ E). The study's outcomes can be useful for regions with drinking water scarcity. To define the level of the corrugated basin's efficiency, two versions (SS-1, SS-2) of experiments were carried out on a two-slope distiller, complete with two basins. In SS-1, basin-2 was heated by air. By 15:00, basin-2 had heated up to 98.5 °C, and the acrylic cover above had heated up to 101.6 °C, which led to its "deformation". By 12.00 p.m., the temperature differentials between the glass (40.7 °C), the air–water mixture (57.3 °C), and basin-1 (61.1 °C) were 16.6 °C and 20.4 °C. This resulted from the wind speed increasing up to 5.9 m/s. The large temperature differential contributed to the condensate yield increasing from 0.128 kg at 11 o'clock to 0.293 kg at 12 o'clock. The throughput capability of basin-1 per day was equal to 2.094 kg. Basin-2's input to the performance in SS-1 was only the thermal effect. In SS-2, basin-2 was used as a regular basin. The plexiglass temperature was lower than the temperatures of the water and basin-2. The temperature differential between the glass and air–water mixture at 10:00 a.m. was 20 °C; at 12:00 p.m. it was 30.6 °C; and a value of 30.6 °C was recorded at 3:00 p.m. The thermal differential between the glass and the air-water mixture provided the highest condensate yield of 1.114 kg at 3.00 p.m. The condensate yield from the basins in SS-2 was 8.72 kg, including 3.5 kg from basin-1, which is 1.7 times more than from basin-1 in SS-1. The experimental results are consistent with the equations coming from the models of Clark J.A. and Dunkle R.V. Tcondensation ≠ Tevaporation is an irreversible process. When the basins are heated, the heat is consumed; when the glass cools down, the heat is given off. Heat losses are minimized due to the "gap" and positive energy is provided. The still's throughput capability can be made larger by increasing the basin's area, reducing the water layer thickness, and regulating the flowrate of the desalinated water. [ABSTRACT FROM AUTHOR]

Objectives. The purpose of this study was to calculate the dynamic air gap thickness between the human body and the turnout gear. Relationships between the air gap thickness and joint range of motion (ROM) were also explored. Methods. The air gap thickness and joint ROM of 12 male firefighters walking in a control condition with no self-contained breathing apparatus (SCBA) and three varying-strapped SCBAs were measured using three-dimensional (3D) body scanning and 3D inertial motion capture. The interpolation technique was employed to predict the air gap thickness curve during walking. The dynamic air gap thickness was compared with the joint ROM to see how they relate to the location and percentage of movement restriction. Results. During the walking, the air gap fluctuated as a sine curve. Carrying SCBA reduced the air gap thickness at the trunk most (F = 11.17, p < 0.001, η2 = 0.63), and adjusting the shoulder strap length altered the air gap distribution at the trunk. The reduced air gap at the pelvis caused an incremental restriction on pelvis rotation. Conclusions. A compatibility design of the shoulder strap and hip belt in SCBA with the turnout jacket is suggested. [ABSTRACT FROM AUTHOR]

In the automotive industry, there has been considerable focus on developing various sensors for engine oil monitoring. However, when it comes to monitoring the condition of brake fluid, which is crucial for ensuring safety, there has been a lack of a secure online method for this monitoring. This study addresses this gap by developing a hybrid silica nanofiber mat, or an aerogel integrated with an optical fiber sensor, to monitor brake fluid condition. The incorporation of silica nanofibers in this hybrid enhances the sensitivity of the optical fiber glass surface by at least 3.75 times. Furthermore, creating an air gap between the glass surface of the optical fiber and the nanofibers boosts sensitivity by at least 5 times, achieving a better correlation coefficient (R2 = 0.98). In the case of silica aerogel, the sensitivity is enhanced by 10 times, but this enhancement relies on the presence of the established air gap. The air gap was adjusted to range from 0.5 mm to 1 mm, without any significant change in the measurement within this range. The response time of the developed sensor is a minimum of 15 min. The sensing material is irreversible and has a diameter of 2.5 mm, making it easily replaceable. Overall, the sensor demonstrates strong repeatability, with approximately 90% consistency, and maintains uncertainty levels below 5% across specific ranges: from 3% to 6% for silica aerogel and from 5% to 6% for silica nanofibers in the presence of an air gap. These findings hold promise for integrating such an optical fiber sensor into a car's electronic system, enabling the direct online monitoring of brake fluid quality. Additionally, the study elucidates the effect of water absorption on the refractive index of brake fluid, as well as on the silica nanomaterials. [ABSTRACT FROM AUTHOR]

In the present study, an attempt has been made to analyse the protection performance of fire-protective clothing. Various exposures to the same fabric in different configurations result in different protection performances. Box-Behnken experiment design was used to optimize the process parameters such as pick density (P), heat flux (Q), and air gap (D). Through surface methodology response, the relationship among the process parameters such as pick density (P), heat flux (Q), and air gap (D) was established. The experimental multi-parametric equation for calculating the radiant protection time (RT) and flame protection time (FT) was acquired. The fabric used was developed with 2/40 Ne Nomex IIIA yarns. The pick density (P) ranged from 40 to 64 picks per inch, heat flux (Q) ranged from 0.5 to 1.5 cal/cm2/sec, and air gap (D) ranged from 0 to 25 mm. To experimentally determine the level of protection, Stoll criteria were used. The experimental and predicted protection time values show a high correlation coefficient value (R2 = 0.985 for radiant and 0.978 for flame). The maximum improvement in protection was obtained at a high level of air gap (25 mm), low level of heat flux (0.5 cal/cm2/sec) and low level of pick density (40 picks per inch). Obtained results, calculations and equations will help researchers explore the empirical equation of the Box-Behnken model and other surface response curves. The values of protection time, in the specified range of the process parameters, by a single calculation could be possible to obtain.

Metal particle and air gap defects on the surface of insulators can induce localized electric field distortions and exacerbate charge accumulation, subsequently triggering surface flashover. In this study, we first enhanced traditional capacitive probes to improve stability and effectively suppress charge leakage. The modified probes achieved a charge leakage time constant exceeding 5600 s, with a leakage amount of only 4.9% over a single data acquisition period (210 s). Based on this improvement, we developed a system for measuring surface charges on insulators, investigating the characteristics and influencing factors of surface charge accumulation under metal micro-particles and air gap defects. The results demonstrate that metal micro-particles adhering to the insulator surface accumulate charges of opposite polarity at different locations under applied voltage. These charges tend to diffuse over time and with increased voltage. The presence of air gap defect accelerates charge accumulation in its vicinity, with charge polarity and location being closely related. When the air gap is near the high-voltage electrode, the insulator surface predominantly accumulates positive charges. Conversely, when the air gap is near the ground electrode, negative charges accumulate at both the high-voltage and ground electrodes, with positive charge accumulating in the central region. Both the amplitude and duration of the applied voltage affect the charge accumulation on the air gap surface. Interestingly, with prolonged voltage application, the surface positive charge density in the air gap decreases. Different defect models exhibit charge inversion phenomena occur as the voltage amplitude increases.

The rapid simulation of the dynamic performance of electromechanical devices such as solenoid valves and relays is important for product development and design. A magnetic circuit model of the non-saturated direct-acting electromechanical motion device is improved, and then coupled with the motion equation of the mechanism to realize the rapid simulation of the electromechanical motion device. In contrast to the ideal magnetic resistance in the conventional magnetic circuit model, the non-saturated total magnetic resistance is expressed by a cubic polynomial of the movement displacement of mechanism. The four undetermined coefficients of the polynomial are calibrated by the simulation values of static magnetic force and inductance at the upper and lower motion limits. The improved magnetic circuit model can more accurately predict the changes of magnetic attraction force and inductance with the motion displacement. Furthermore, coupled with the motion equation of the electromechanical motion device, the improved model establishes an improved magnetic circuit-motion coupled model and realizes fast second-level simulation of an electromagnetic brake and valve in the Simulink system, which can greatly reduce the finite element simulation time while maintaining simulation accuracy.

Standard log transmission protocols do not offer a robust way of segregating the log network from potential threats. A secure log transmission system and the realization of a data diode using affordable components are proposed. Unidirectional data flow prevents unauthorized access and eavesdropping, ensuring the integrity and confidentiality of sensitive log data. The system uses an encryption protocol that requires that the upstream and the downstream of the data diode are perfectly synchronized, mitigating replay attacks. It has been shown that message amplification can mitigate UDP packet loss, but this is only required when the data diode traffic is congested. The implementation of the encryption algorithm is suitable for resource-constrained devices and it has been shown to produce random-looking output even on a reduced number of rounds when compared to the parent cipher. Several improvements have been made to the original encryption algorithm for which an actual implementation was missing. Free software and datasets have been made available to reproduce the results. The complete solution is easy to reproduce in order to secure the segregation of a log network inside any scenario where logging is required by the law and log tampering must be prevented.

Standard calculation of the torque transmitted by a magnetic end coupling is considered for a coupling that consists of two highly coercive permanent magnets (thickness 4.5 mm) made of samarium–cobalt alloy. The air gap between the magnets in the half-couplings is 5–20 mm. A correction factor is obtained for use in calculating the torque transmitted by a coupling based on paired thin magnets. [ABSTRACT FROM AUTHOR]

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An air gap in thermal protective clothing (TPC) plays an important role in determining heat transfer, but it may also increase the amount of stored thermal energy that would discharge to the skin after exposure, especially when the TPC suffers compression. To investigate the effect of air gap and compression on the dual thermal protective performance (TPP), thermal hazardous performance (THP) and overall thermal protective performance (OTPP) of TPC, nine air gap configurations with different sizes and positions and five compression levels were designed in this study. Regression models were established to explore the relationships among air gap size, compression and THP for different air gap positions. The results demonstrate that increasing the air gap size without exceeding 12 mm not only significantly enhances the TPP by impeding heat transfer from the heat source to the fabric system during exposure but also decreases the THP by reducing heat discharge from the fabric system to the sensor even when compression is applied. Although an inner air gap contributes more to increasing the TPP during exposure than an outer air gap, it may also bring about severe stored energy discharge when compression is applied. It suggests that a larger air gap size should be divided into individually separate air gaps within different fabric layers to reduce the heat transfer during exposure as well as lower the stored thermal energy discharge after exposure. [ABSTRACT FROM AUTHOR]

Objective To analyze the efficacy of the 3D printing compensation film in the postoperation radiotherapy for breast cancer patients after immediate breast reconstruction. Methods A total of 11 patients who underwent immediate breast reconstruction after modified radical mastectomy in Hunan Cancer Hospital from November 2021 to May 2022 were selected. The same sequence was used to perform CT positioning scanning after covering the 3D printing compensation film and the commercial compensation film, and the air gap, target area and organs at risk were delineated. Two intensity modulated radiation therapy (IMRT) plans were designed with the same parameters (Plan A: 3D printing compensation film; Plan B: commercial compensation film). The differences between the two plans were analyzed with respect to air gap, homogeneity index (HI), new conformity index (nCI), the mean dose (Dmean), V5, V20, V30 of the lung on the affected side lung, the cardiac dose V30 and the healthy side breast Dmean. Results The air gap volume of Plan A was smaller than that of Plan B［(8.029±2.542) cm3 vs (20.048±4.372) cm3, t=-5.300, P<0.001］. Compared with those of Plan B, the HI［(0.134±0.008) % vs (0.161±0.016) %, t=-2.246, P=0.049］, the healthy breast Dmean［(159.909±17.925) cGy vs (173.364±19.248) cGy, t=-2.343, P=0.041］and the lung on the affected side lung V20［(25.782±0.876) % vs (26.373±0.836) %, t=-2.334, P=0.042) of Plan A were decreased, and the nCI was increased［0.79% (IQR: 0.77%-0.83%) vs 0.78% (IQR: 0.75%-0.81%), Z=-2.316, P=0.021］, but there was no significant difference in cardiac dose V30, and the affected side lung Dmean, V5 and V30 (all P>0.05). Conclusions In patients with immediate breast reconstruction after radiotherapy for breast cancer, the 3D printing compensation film has advantages over the commercial compensation film with respect to fitness to skin, dose distribution and uniformity in the target area, improving the epidermal dose while reducing the dose of exposure to organs at risk, and has certain potential value in clinical application. [ABSTRACT FROM AUTHOR]

An experimental injection molding setup was designed and fabricated. The purpose of the setup is to cast polymer components and estimate the polymer/mold interfacial heat flux transients during injection molding. The mold plate is instrumented with K‐type thermocouples to record its thermal history continuously during the cyclic process. Experiments were performed at a melt injection temperature of 280°C. Velocity and shear rate profiles were determined to assess the flow behavior of the melt. The spatiotemporal heat flux transients at the interface and the mold surface temperature were estimated using measured temperature data inside the mold as input to an inverse heat conduction problem. The estimated boundary heat flux transients were used to numerically simulate the polymer melt's cooling behavior. From the estimated heat flux and surface temperatures, heat transfer coefficients (HTC) were determined. The peak value of the HTC was 5775 W/m2K and occurred at a mold surface temperature of 35.7°C and polymer surface temperature of 47.4°C. The evolution of the air gap at the interface was quantified using an exponential fit. The estimated air gap width corresponding to peak HTC was about 4 μm and increased to about 100 μm towards the end of the solidification. While the peak heat flux is associated with the start of the formation of polymer skin on the mold surface, the peak HTC corresponds to the onset of nucleation of the air gap or a nonconforming contact. Highlights: An experimental setup to study heat transfer during injection molding.Spatiotemporal heat flux transients (q) were estimated during injection molding.Polymer temperatures were simulated using q, and HTC was determined.The peak HTC indicated the onset of nucleation of an air gap.Evolution of air gap at the interface was modeled using an exponential fit. [ABSTRACT FROM AUTHOR]

The design of a hardening process that can achieve the desired level of hardening quality is paramount for spur gear teeth, as a poorly executed process may result in a variety of defect schemes. The mobile induction hardening technique has emerged as a promising and cost-effective method for large spur gears. However, achieving the desired output quality remains challenging. This study aims to comprehensively evaluate the results of gear tooth hardening using the tooth-to-tooth mobile induction hardening process. The evaluation process focuses on the tooth flank, which is the area most prone to failure. The study investigates the effects and interactions of crucial process parameters, such as flank length, scanning speed, and air gap, on the hardening results. Numerical and experimental measurements are used to characterize the hardening results. The study's results demonstrate high accuracy in the modeled numerical simulation, with prediction errors ranging from 3.02 to 4.05% across different experiment-numerical validation scenarios. The induction heating and spray cooling design employed in the study generates sufficient heating energy to achieve an average austenite distribution of 97.13% in the heat-affected zones and an average martensite phase of 82.21% during the quenching process. A tempering process is then carried out as a standard procedure to enhance the material's ductility, resulting in a decrease in material hardness from a maximum of 64.77 HRC initially to a maximum of 61.98 HRC. Multivariable non-linear regression analysis confirms the significant influence of the studied process parameters on flank hardening quality, with the scanning speed parameter having the most substantial impact. The quantitative results indicate that reducing the scanning speed, air gap, and flank length leads to better hardening quality in terms of longer hardened flank, deeper hardening depth, and smaller edge effects. Insights provided in this study are very beneficial to build intuitions in obtaining desired hardening quality of tooth flank using mobile induction hardening. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, a generalized torque estimation method is proposed for synchronous motors, including surface permanent magnet synchronous motors (SPMSMs), synchronous reluctance motors (SynRMs), and interior permanent magnet synchronous motors (IPMSMs) for building the analytical motor model. The average motor torque is estimated using the Lorentz force by the generated flux density in the air gap to determine the relationships among torque, flux density, and injected current. In the proposed method, the generated flux density is derived step by step by considering the effects of magnetic flux saturation, the stator slot, the rotor barrier, and permanent magnets (PMs) to ensure that the generated average torque complies with the operating condition of the motor. To verify the proposed method, the output torque of finite element analysis (FEA), Maxwell 2D, is compared to the proposed method in a SPMSM. Moreover, a phasor diagram is plotted to determine the mechanism through which torque is generated in SynRMs and IPMSMs. A SynRM and an IPMSM with ferrites PMs are analyzed using the proposed method, FEA, and the experimental results of this study indicate the effectiveness. [ABSTRACT FROM AUTHOR]

The rotor of a high-power water-filled submersible motor rotates at high speed in liquid during operation. while working motor internal air gap fluid flow in complicated cases, fluid flow characteristics is not only directly affect the water of the rotor friction loss, also affect the submersible motor cooling effect. In this paper, the fluid field in the inner cavity of submersible motor is deeply studied. The air-gap fluid grid model was established according to computational fluid dynamics, and the influence of air-gap on fluid velocity of submersible motor was studied based on ANSYS and FLUENT software. The results show that the pressure decreases linearly after the cooling water enters the motor air gap, the maximum pressure is located at the air gap inlet and the minimum at the air gap outlet; the outlet and inlet pressure of the air gap fluid grows with the increase of the air gap inlet fluid flow rate, and the growth rate tends to decrease in different degrees. The research results provide a basis for the design of submersible motor and the determination of the reasonable flow of fluid in the motor. [ABSTRACT FROM AUTHOR]

Polyether sulfone hollow fiber membrane was prepared via nonsolvent‐induced phase separation process using dimethylacetamide (DMAc) as a solvent, Polyvinylpyrrolidone (PVP‐K30) and water as additives. The mechanism of air gap environment in the membrane structure formation was studied. The scanning electron microscope microstructure morphology revealed that the air gap environment induced the microstructure formation of membranes. The low humidity air gap environment was not conducive to the surface pore formation and hard to obtain surface pores until lowering the dope solution temperature. The high humidity can easily induce the formation of large out surface pore structure along with the decreases of the surface pore uniformity. As air gap humidity and distance increased, the membrane cross section structure near the outer surface tends to be looser and that near the inner surface became denser, while the proportion of finger‐like pores in the cross section initially increased and stabilized. At 100 RH, the average outer surface pore size increased from 0.192 μm at an air gap distance of 20 cm to 0.351 μm at 50 cm, the corresponding pore density decreased from 2.66 to 1.13 pores/μm2, and the percentage of the inner skin layer thickness increased from 3.26% to 7.69%. [ABSTRACT FROM AUTHOR]

The article proposes an approach to determining the uneven air gap of a synchronous machine with prismatic magnets on the rotor, in which the distribution of the normal component of magnetic induction along the inner circumference of the stator core has a shape close to sinusoidal. The calculation of the magnetic field of an electric machine model with the specified geometric dimensions and properties of the element materials is performed in the FEMM program. To solve the optimization problem, the Hook-Jeeves method is used, restrictions are taken into account by the method of penalty functions. As a result of modeling the magnetic field of an electric machine with a calculated optimal uneven air gap, a distribution curve of the normal component of magnetic induction along the inner circumference of the stator is obtained, the average deviation of which from the sinusoidal curve is 4,8 %.

The world today runs on data, every minuscule task to the large one requires data. All the data is stored in the various technologies that we use. And to keep data safe, air gaps are introduced. Air gaps are a network security measure where secure computer networks are physically isolated from unsecured networks. Yet, different methods to hack the air gap have come forth. The paper analyzes the problem of hacking an air gap via screen brightness modulations. The proposed solution is a software program used to alert the user of a change in the brightness level of the screen. The concept of Windows Management Instrumentation (WMI) has been used to put forth the software. Applied to an air-gapped computer, the program displays an alert box immediately, as the screen brightness changes. The solution is an easy and efficient way to counter the attack. The program can be further implemented in different testing environments and the WMI concept can be applied to various other cyber hacks.

Disposal canisters and buffer materials are main components in an engineered barrier system designed for high-level radioactive waste disposal. The design temperature of the buffer material is below 100 °C in most countries, and many studies have been conducted to increase the design temperature of the buffer material to increase the disposal density of the repository. A 1-cm air gap exists between the canister and buffer material that can cause several variations in the thermal–hydraulic–mechanical performance of the compacted bentonite buffer material. Therefore, considering the air-gap effect under high-temperature conditions is necessary because high temperatures can cause pressure variations in the air gap and compacted bentonites. Therefore, an experimental system was developed to measure the pressure variations in a confined cell, which contained air and compacted bentonites from room temperature to 150 °C. The pressure of the confined cell increased with increasing water content of the compacted bentonite, and the pressure changes were similar up to 100 °C irrespective of the presence of the 1-cm air gaps. Moreover, the pressure values at 150 °C were 10–15% higher in samples without gaps.

Radiation therapy for treating shallow tumors is challenging, necessitating the use of boluses. This study introduces the first application of the life-casting method to fabricate patient-specific bolus molds from gypsum sheets, comparing them with commercial boluses. Our developed boluses reduced the air gap between the skin and bolus by 77.62% compared to that of commercial boluses. In vivo dosimetry using the patient-specific bolus demonstrated better results compared to using a commercial bolus. When using the commercial bolus, the mean %Diff and max %Diff were 1.10 ± 0.61%, respectively, and 2.00% for three-dimensional conformal radiation therapy (3D-CRT) and 7.19 ± 1.90% and 10.14% for volumetric modulated arc therapy (VMAT), respectively. Contrastingly, our developed bolus demonstrated more accurate dose delivery with a mean %Diff and max %Diff of 0.82 ± 0.61% and 1.69% for 3D-CRT and 3.42 ± 1.01% and 5.03% for VMAT, respectively. Furthermore, the standard deviation between the measurements was more than 50% lower when using a patient-specific bolus than when using a commercial bolus. These results show that our bolus reduces air gaps, improves the accuracy of bolus positioning, and enhances the precision of dose delivery compared with the performance of commercial boluses. Therefore, the developed bolus is expected to be valuable in clinical applications. [ABSTRACT FROM AUTHOR]

Asymmetry of the air gap in electrical machines impairs the output characteristics of both motors and generators. This asymmetry affects the magnetic induction at the poles and hence the pulsations of the electromotive force, current, and torque. The unidirectional attractive force of the rotor due to the asymmetry results in premature bearing failure and loss of the machine's reliability. The causes and consequences of the rotor's unidirectional attractive force are investigated, and analytical formulas are given for the asymmetry of the field and the magnetic attractive force. [ABSTRACT FROM AUTHOR]

In recent years, numerical simulations have been playing an increasingly important role in the process of casting optimization. The reliability and validity of numerical simulation results are significantly determined by the accuracy setting of the interfacial heat transfer coefficient (IHTC). In this paper, the change law of IHTC between ring type castings and cores under different conditions is systematically investigated by using the Beck inverse algorithm, numerical simulation method and temperature field measurement data with AISI1045 steel as casting material and no-bake furan resin bonded sand as core material. The results show that the change of IHTC with time is in the form of "bimodal" after the cavity is poured, and the value increases rapidly to the maximum after pouring, and then decreases gradually to the minimum, followed by a slow increase and slow decrease process. The accuracy of the calculated IHTC was verified by using Procast software. [ABSTRACT FROM AUTHOR]