Side Window Research Articles

Research on Temporal–Spatial Partition Control Strategies for Luminous and Thermal Environment in High Space of Gymnasiums

The lighting design of large-space buildings in gymnasiums can impact the indoor luminous and thermal environment, resulting in an uneven light and thermal distribution. This paper investigates the luminous and thermal environment control strategies for high spaces in gymnasiums, by simulating the luminous and thermal environment under different lighting forms and establishing a comprehensive evaluation model. The results show that the weights of the indoor luminous environment, thermal environment, and comprehensive energy consumption change with season and time under different lighting forms, which provides a basis for developing a temporal–spatial partition control strategy. The temporal–spatial partition control strategy is proposed for summer and winter, including the shading angle control under the lighting forms of south-facing side windows, west-facing side windows, and top skylights. Under summer conditions, the south-facing side windows have no shading from 8:00 to 10:00 and 14:00 to 16:00, and the shading angle is 0° from 10:00 to 14:00; the west-facing side windows have no shading from 8:00 to 14:00, the shading angle is 0° from 14:00 to 15:00, and the shading angle is 15° from 15:00 to 16:00; and the top skylight has a shade angle of 15° from 8:00 to 9:00, 30° from 9:00 to 11:00, 45° from 11:00 to 13:00, and no shade from 13:00 to 16:00. Under winter conditions, the south-facing side windows have no shading all day; the west-facing side windows have no shading from 8:00 to 14:00, and the shading angle is 30° from 14:00 to 16:00; and the top skylight has no shading from 8:00 to 13:00, a shading angle of 45° from 13:00 to 15:00, and a shading angle of 75° from 15:00 to 16:00. This paper provides a set of scientific and reasonable luminous and thermal environment regulation strategies for large-space buildings, which can help optimize the building energy consumption and improve the indoor environment quality.

Viewing angle controller using two parallel alignment liquid crystal cells for automotive systems.

We proposed a viewing angle controller (VAC) for car co-driver displays (CDDs). This VAC, integrated with the co-driver display, provides necessary information to the co-driver while minimizing driver distraction. It comprises two parallel alignment liquid crystal cells and two negative C films. It maintains a wide viewing angle without an applied voltage, and it can achieve an anti-peeping angle of 35° (simulation) and 30° (experiment) under an appropriate voltage, effectively blocking the driver's direct-view light intensity from CDD and reflect-view light intensity from the side window, which can reduce the driver's attention. This VAC maintains excellent light transmittance at a normal direction and symmetrical brightness in both privacy and share modes, making it suitable for various in-vehicle displays. Those results indicate that this VAC can be broadly applied in automotive displays to enhance driving safety and improve co-driver entertainment.

Visualization experimental study on the boiling characteristics of vapor chamber evaporator surface with different heat sources

The effective functioning of vapor chambers depends on the phase change of the working fluid at the wick surface. Given the prevalent role of vapor chambers in thermal management in the electronics industry, it is critical to study the boiling characteristics and thermal performance of vapor chambers, as well as the effect of heat source conditions. In this work, to observe phase change at the wick surface, the visualization confined chamber with wick (VCCW) is proposed and fabricated, which features a side window and a 2 mm thick wick sintered with aluminum powders. The working fluid used is acetone. The heat source is designed in three different sizes to heat the VCCW in either the middle or right position. The experimental results show that the boiling curve is divided into four stages. In the stage Ⅰ, the boiling curve is linear, and the visualization results reveal that the phase change phenomenon on the wick surface is evaporation. The Ⅱ stage is defined as ONB (Onset of Nucleate Boiling) for the vapor chamber evaporator surface. The boiling curve shows a turning, and bubbles were observed to appear and spread by visualization. In the Ⅲ and Ⅳ stages, the boiling curve remains linear. The stable nucleate boiling and intermittent local dryout is observed before and after the DNB (Departure from Nucleate Boiling). The slope of the boiling curve increases as the size of the heat source enlarges, which contributes to greater superheat and evaporation of the working fluid at smaller heat fluxes. Moreover, the position and size of the heat sources affect the ONB and DNB due to heat diffusion and capillary-driven supply of fluid.

Optimization Strategy for Thermal Comfort in Railway Stations above Ground Level in Beijing

Urban rail transit, a convenient and fast public transportation mode with rapid construction and development, occupies fewer land resources and accommodates large passenger volumes. However, thermal comfort should be given more attention. Stations above ground level experience poor thermal comfort on the platforms, especially in hot summers. This study combines field research with a simulation analysis to propose a strategy for improving thermal comfort on above-ground urban rail transit platforms. This study analyzed the effects of the skylight opening rate, side window opening rate, design of transparent maintenance structure shading, and the platform profile shape on the thermal comfort of above-ground stations using field research, comparative experiments, and a simulation analysis with the PHOENICS (Command Prompt) software. The results indicate that adding longitudinal sunshade louvers to the skylight of the station platform is a cost-effective method to reduce the average temperature and PMV value, thereby improving thermal comfort. Increasing the skylight opening rate can result in a temperature rise. Adjusting the opening rate of the side windows to 20% and adding sun-shading louvers can also significantly enhance the station’s thermal comfort. Taking Wudaokou Station on Beijing Line 13 as an example, the simultaneous installation of additional longitudinal skylight shading and side window shading and increasing the side window opening rate to 20% on the platform resulted in a 2.6 °C decrease in the average temperature, a 4.7% increase in the average wind speed, and a 0.62 decrease in the PMV value, significantly enhancing thermal comfort for passengers. This study confirms that optimizing shading and ventilation systems can significantly reduce the platform temperature and improve passengers’ thermal comfort. This study provides theoretical support and innovative methods for optimizing thermal environments in similar environments.

Integrating aboveground and underground environments to enhance underground natural ventilation in the tropics: Case studies in Singapore

Ventilation is the primary solution for addressing elevated temperatures, humidity, and pollution with underground environments. Underground natural ventilation stands as a historical and promising strategy to reduce energy consumption and diminish reliance on mechanical ventilation. This study integrates aboveground and underground environments to enhance underground natural ventilation in the tropics. Initially, the study employed field measurements and computational fluid dynamics simulations to compare the natural wind environments and architectural designs of enclosed and detached condominiums in Singapore. The results demonstrate a strong correlation between the aboveground and underground wind environments in the enclosed condominium, revealing distinctive airflow patterns conducive to ample ventilation. Conversely, the basement of the detached condominium lacked natural ventilation and had tenuous connections to aboveground wind environments despite incorporating numerous skylights and side windows. Subsequently, the study proposes optimising architectural designs for row buildings through cross ventilation, sunshade, and greenery inspired by the architectural design of the enclosed condominium. Moreover, this study suggests some design strategies applicable to the tropics in hot and humid climates. These findings help architects and engineers create sustainable, natural, airy underground spaces.

Daylighting Evaluation of Perforated Screen Façade with Light Shelf in the Tropics

The use of large glass facades in buildings without external shading devices leads to a high daylight level, uneven daylight distribution, and glare. A perforated screen facade (PSF) is one of the shading systems that can provide daylight and view and prevent direct solar radiation into a building. More research is needed about the daylight performance of PSF in integration with daylighting systems in the tropics. A combination of PSF and light shelf (LS), a daylighting system that can redirect daylight to the ceiling and enhance daylight distribution, is proposed to improve daylight levels and reduce glare. The research aims to evaluate the daylight performance of PSF and LS in the tropics. The research method is experimental with simulation utilizing IES-VE Radiance IES. Average Daylight Factor (DFavg), Useful Daylight Illuminance (UDI), and Daylight Glare Probability (DGP) of a room with a side window were compared with a room with PSF and LS. The results showed that implementing PSF and LS improved daylight performance by lowering the DFavg by 55%, increasing the UDI, and reducing the DGP.

P‐132: Effect of Pre‐Alert Method for Visually Reduced Motion Dizziness for Vehicle Displays

Using displays such as smartphones, in‐car TVs or even fusion information on the side windows of a moving vehicle may cause motion sickness. A visual based pre‐alert method is presented to address the issue and a MSSQ method is applied to assess the sickness degree. A Human factors experiment has been conducted to demonstrate the effectiveness of the proposed method.

A robust and accurate feature matching method for multi-modal geographic images spatial registration

ABSTRACT While the current research has achieved satisfactory results for the registration of single mode data, there has always been a significant challenge in the registration of multi-modal images due to the obvious nonlinear radiation differences caused by different imaging mechanisms and imaging time. For example, multi-temporal visible, visible-synthetic aperture radar, visible-near infrared, near infrared-short wave infrared, visible-MAP, etc. To address this problem, we propose a Robust and Accurate Feature Matching Method for Multi-modal Geographic Images Spatial Registration (RAMMR) to fully extract common key points between images, weaken the radiation difference between data, and finally accurately match more inliers to realize multi-modal image registration. Considering the influence of noise and edge information on key point extraction, RAMMR first constructs a new scale space by introducing the Side Window Filter (SWF); Then, we improve Harris algorithm to extract key points based on the SWF scale space; After that, we propose an enhanced log-polar descriptor based on the gradient angles and gradient amplitudes of the scale space, which effectively improves the quality of the descriptor and avoids the mismatch of key points; Based on the standard Euclidean distance, we design a re-match strategy to obtain the initial matching results, and Random Sample Consensus (RANSAC) is used to eliminate outliers. Finally, the affine transformation parameters are calculated based on inliers, and multi-modal image registration is realized. RAMMR is evaluated on different multi-modal datasets and compared with some state-of-art methods. The experimental results show that RAMMR accurately registers multi-modal geographic images and obtains comparative results compared with benchmark methods. Our source datasets are publicly available at https://github.com/RSmfmr/multimodal-dataset.

Parametric optimization of rearview mirror structure based on a multi-island genetic algorithm

To quickly find the structural parameters of a particular mirror that produces the least amount of aerodynamic noise, the rearview mirror of a passenger car is taken as the research object and an optimization platform is established based on Isight software in this paper. The mirror structure is parameterized in Sculptor, and several sample models are constructed using the optimal Latin hypercube design (OLHD). Then, by simulating each sample model, the sound pressure level of the Curle source at the side window surface monitoring point was obtained. The relationship between the mirror structure and the wind noise at the point is fitted using the Kriging approximation model after the calculation is completed. Finally, the values at each point decreased when the changes at positions 1, 2, 3, and 4 were 2.5 mm, 3.91 mm, 4.5 mm, and 3.6 mm, and the sound pressure level at monitoring point 4 decreased the most, with a reduction of 3.76 dB in wind noise compared with the original model.

TECHNOLOGY OF VACUUM TIGHT SEALING OF MICROBOLOMETER PACKAGE

The features of the design of micro bolometer packages are considered, the choice of preform material for sealing the package with a soldered seam is made. The characteristics of getter films and the advantages of applying them to the reverse side of a germanium window are presented. A technique for vacuum-tight sealing of micro bolometer packages with germanium windows has been developed.

CFD Analysis and Optimization of a Plastic Greenhouse with a Semi-Open Roof in a Tropical Area

A numerical simulation model of a natural ventilation greenhouse is helpful for improving the production and quality of greenhouse crops in tropical areas. Field experiments show that the mean coefficient of variation of indoor light intensity in four seasons was lower than 10.0%. The highest indoor temperature reached 39.3 °C during summer, while the average indoor temperature ranged from 24 °C to 26 °C in the other three seasons. The average relative humidity in the greenhouse ranged from 76% to 87% annually, which was higher and more stable than that in the external environment. A three-dimensional steady-state numerical model of the greenhouse was established based on computational fluid dynamics. Under natural ventilation conditions, the maximum error between the simulated value and the measured value of the temperature in each measuring point was 5.90%. And the average relative error between the simulated and measured values was 3.0% in the range of 0.7−1.5 m of crop cultivation height. Finally, a numerical simulation of adding side windows and expanding the vents was carried out. The results show that these methods can homogenize the airflow distribution in the greenhouse and improve the utilization efficiency of natural ventilation without more mechanical system operations.

Effect of desorbed gas on microwave breakdown on vacuum side of dielectric window

The gas desorbed from the dielectric surface has a great influence on the characteristics of microwave breakdown on the vacuum side of the dielectric window. In this paper, the dielectric surface breakdown is described by using the electromagnetic particle-in-cell-Monte Carlo collision (PIC-MCC) model. The process of desorption of gas and its influence on the breakdown characteristics are studied. The simulation results show that, due to the accumulation of desorbed gas, the pressure near the dielectric surface increases in time, and the breakdown mechanism transitions from secondary electron multipactor to collision ionization. More and more electrons generated by collision ionization drift to the dielectric surface, so that the amplitude of self-organized normal electric field increases in time and sometimes points to the dielectric surface. Nevertheless, the number of secondary electrons emitted in each microwave cycle is approximately equal to the number of primary electrons. In the early and middle stages of breakdown, the attenuation of the microwave electric field near the dielectric surface is very small. However, the collision ionization causes a sharp increase in the number density of electrons, and the microwave electric field decays rapidly in the later stage of breakdown. Compared with the electromagnetic PIC-MCC simulation results, the mean energy and number of electrons obtained by the electrostatic PIC-MCC model are overestimated in the later stage of breakdown because it does not take into account the attenuation of microwave electric field. The pressure of the desorbed gas predicted by the electromagnetic PIC-MCC model is close to the measured value, when the number of gas atoms desorbed by an incident electron is taken as 0.4.

An indirect Z-scheme heterostructure of nano-gold layer immobilized Cu-Al-doped SrTiO3 and CoOx-WO3 for photocatalytic CO2 reduction

Perovskite oxides have emerged as promising photocatalysts for CO2 reduction to valuable chemicals and fuels. However, conventional perovskite oxide photocatalysts often suffer from inefficient charge separation and bulk charge recombination, negatively impacting overall photoactivity. In this work, we present a novel immobilized perovskite oxide-based photocatalyst sheet featuring an indirect Z-scheme heterostructure composed of Cu-loaded Al-doped SrTiO3 (Cu-ASTO) and CoOx-loaded WO3 (CoOx-WO3) with an ultrathin (20 nm) gold interlayer serving as a conductive bridge. We tested this photocatalyst sheet in a sealed reactor containing a CO2-saturated aqueous solution of 0.1 M NaHCO3 and a side window to allow irradiation. Under irradiation with a 300 W Xe lamp, the Cu-ASTO/Au/CoOx-WO3 immobilized photocatalyst sheet produced methane (CH4) at a rate of 2.676 µmol cm-2 h−1 and methanol (CH3OH) at 0.517 µmol cm-2 h−1. We attribute the superior activity of this catalyst to the all-solid-state indirect Z-scheme heterostructure that greatly extends the lifespan of photoinduced charge carriers and enhances the CO2 photoconversion reaction. In experiments conducted outside, we demonstrated the immobilized photocatalyst's performance under natural sunlight, producing CH4 at 0.307 µmol cm-2 h−1 and CH3OH at 0.069 µmol cm-2 h−1. This work provides design ideas for developing robust immobilized photocatalyst systems for the scalable operation of the CO2 photoreduction process and broadening the scope of applications for perovskite heterostructure photocatalysts.

Ultrasonographic Evaluation of Gastro-intestinal Dysfunction in Rescued Olive Ridley Sea Turtles (Lepidochelys olivacea)

Background: The olive ridley sea turtle is a common inhabitant of primarily in the Pacific and Indian Oceans. Sea turtles show poor clinical signs and due to the existence of carapace and plastron, physical examination requires complementary diagnostic methodology to provide valuable information for clinical diagnosis. Methods: This work describes the normal ultrasonographic appearance of cervical structures and gastro-intestinal organs of seven olive ridley sea turtles that were stranded during September 2017 to April 2018 along with rescued sea turtle by Trust for Environmental and Education (TREE) foundation, Vettuvankeni, Chennai, Tamil Nadu. Ultrasound examination was performed with multi frequency Probe (3.5 MHz to 7.5 MHz) transducer. Ten soft-tissue areas of integument were used as acoustic windows. Result: On ultrasonographic examination of the cervical-ventral acoustic window, the esophagus was imaged. The stomach was more frequently seen through the left axillary acoustic window. The liver could be imaged through both sides of the axillary window and the right axillary acoustic window was the most indicated to visualize the gallbladder. The large and small intestines could be seen in the prefemoral and post femoral acoustic window on the both the sides. The ultrasonographic measurement of various organs was done furthermore gastrointestinal dysfunctions were recorded. This study on ultrasound indices was found to be a useful diagnostic tool for evaluation of coelomic organs in olive ridley.

Outer Sphere Electron Transfer Enabling High-Voltage Aqueous Electrolytes.

Aqueous electrolytes with a low voltage window (1.23 V) and prone side reactions, such as hydrogen evolution reaction and cathode dissolution, compromise the advantages of high safety and low cost of aqueous metal-ion batteries. Herein, introducing catechol (CAT) into the aqueous electrolyte, an outer sphere electron transfer mechanism is initiated to inhibit the water reactivity, achieving an electrochemical window of 3.24 V. In a typical Zn-ion battery, the outer sphere electrons jump from CAT to Zn2+-H2O at a geometrically favorable situation and between the solvation molecules without breaking or forming chemical bonds as that of the inner sphere electron transfers. The excited state π-π stacking further leads to the outer sphere electron transfer occurring at the electrolyte/electrode interface. This high-voltage electrolyte allows achieving an operating voltage two times higher than that of the usual aqueous electrolytes and provides almost the highest energy density and power density for the V2O5-based aqueous Zn-ion full batteries. The Zn//Zn symmetric battery delivers a 4000 h lifespan, and the Zn//V2O5 full battery achieves a ∼380 W h kg-1 energy density and a 92% capacity retention after 3000 cycles at 1 A g-1 and a 2.4 V output voltage. This outer sphere electron transfer strategy paves the way for designing high-voltage aqueous electrolytes.

Lightweight and Real-Time Infrared Image Processor Based on FPGA.

This paper presents an FPGA-based lightweight and real-time infrared image processor based on a series of hardware-oriented lightweight algorithms. The two-point correction algorithm based on blackbody radiation is introduced to calibrate the non-uniformity of the sensor. With precomputed gain and offset matrices, the design can achieve real-time non-uniformity correction with a resolution of 640×480. The blind pixel detection algorithm employs the first-level approximation to simplify multiple iterative computations. The blind pixel compensation algorithm in our design is constructed on the side-window-filtering method. The results of eight convolution kernels for side windows are computed simultaneously to improve the processing speed. Due to the proposed side-window-filtering-based blind pixel compensation algorithm, blind pixels can be effectively compensated while details in the image are preserved. Before image output, we also incorporated lightweight histogram equalization to make the processed image more easily observable to the human eyes. The proposed lightweight infrared image processor is implemented on Xilinx XC7A100T-2. Our proposed lightweight infrared image processor costs 10,894 LUTs, 9367 FFs, 4 BRAMs, and 5 DSP48. Under a 50 MHz clock, the processor achieves a speed of 30 frames per second at the cost of 1800 mW. The maximum operating frequency of our proposed processor can reach 186 MHz. Compared with existing similar works, our proposed infrared image processor incurs minimal resource overhead and has lower power consumption.

Effect of Impingement Angle on Flame Stability in a Non-Premixed Methane/Oxygen Diffusion Flame Burner

ABSTRACT The focus of this research was understanding the effect of varying the secondary flow impingement angle of a single coaxial injector in an experimental non-premixed flame burner on flame stability. The burner was a horizontally mounted, rectangular combustion chamber with retractable spark plug for ignition. Reactants were gaseous oxygen and methane as the primary and secondary flow, respectively. Three injectors were designed and fabricated with exit impingement angles of 15, 30, and 45 degrees with the primary flow. The diffusion flame behavior and flame standoff distance length was observed through optical chamber side windows parallel to the axis of the flame. Stability maps of the diffusion flame behavior based upon equivalence ratio, reactant Reynolds numbers, and injector impingement angle were created. It was observed that the 15 degree impingement angle generated the most stable, anchored diffusion flames for high equivalence ratios and low Reynolds numbers. As impingement angle increased, stable, anchored flames transitioned from existing at fuel-lean highly turbulent primary flows to fuel-rich, highly turbulent flows as well as from fuel-rich, low primary flows to no ignition under the same conditions. Therefore, secondary flow impingement angle can drastically influence the location and range of stable, anchored methane/oxygen diffusion flames.

Optimization of single-channel active noise control performance in a plenum window using the surface impedance approach.

The use of active noise control (ANC) implementation in plenum window design is investigated in this study. Various simulated configuration of a single-channel ANC is performed using the surface impedance approach (SIA) in order to optimize ANC performance. Based on a systematic search procedure, the optimal control source placement is found for a control source localized at the central bottom and central depth of the plenum window, near the window's inlet from which primary noise is impinging. The optimized ANC configuration provides an average attenuation benefit of 9.2 dB between 200 and 630 Hz. Error sensor location in the plenum window cavity is not crucial for the ANC system and does not need to be rigid. A dual-channel ANC system with control sources at both sides of the plenum window can extend the frequency of control to ∼800 Hz with an average attenuation of 7.6 dB. Additionally, an experimental case study using a real-time ANC system is conducted with a built-to-scale plenum window in an apartment informed by findings from the SIA simulation, demonstrating the usefulness of the SIA in ANC optimization process.

Deep learning-based wind noise prediction study for automotive clay model

Analyzing and mitigating wind noise in automobiles is a significant issue within the realm of noise, vibration, and harshness. Due to the intricate nature of aeroacoustic generation mechanisms, current conventional methods for wind noise prediction exhibit limitations. Hence, deep learning methods are introduced to investigate wind noise in the side window area of an automotive clay model. During aeroacoustic wind tunnel experiments, side window vibration data and noise data from the driver were collected at experimental wind speeds of 100 km h−1, 120 km h−1, and 140 km h−1, respectively. These data samples were obtained to be used for training and validation of the wind noise model. Convolutional neural network (CNN), residual neural network (ResNet) and long short-term memory neural network (LSTM) algorithms were separately employed to reveal the complex nonlinear relationship between wind noise and its influencing factors, leading to the establishment of a wind noise prediction model. Simultaneously, these deep learning methods were compared with backpropagation neural network (BPNN), extreme learning machine (ELM), and support vector regression (SVR) methods. Conclusion indicates that the LSTM wind noise prediction model not merely exhibits higher accuracy, but furthermore demonstrates superior generalization capabilities, thereby substantiating the superiority of this method.

Design and Development of a Heating System to Control Windshield Fog

Road visibility in passenger vehicle is of major concern for the car manufacturers and safety design engineers. Water film (Fog) that forms on the windshield during winter times would reduce and disturb the driver’s visibility. Extreme weather condition can make a difference while driving. One may experience the wide range of challenges during driving. The factors which mostly affected the visibility can be rain, fog, ice, snow, dust, etc. Due to such factors, it becomes very tough for driver to have a clear view of front side. Rear view is possible with the help of left and right view mirror fitted outside the front doors. Visibility of rear view mirror depends upon the visibility of the front side window glasses. Driving through rain, produces more challenging situation when water droplets on outsides surface of front window glass obstruct the vision. This problem becomes more dangerous when light gets scattered through water droplets and obstruct the vision during rainy night. The main objective of this work is to find the possible solution for removing the fog from a specific area of front and rear windshield to have a clear view to avoid the accidents. In the present work, hot water and silicon fluid utilized to impinge on the front and rear glasses with the help of converging nozzle and fluid inside the two windshields. The various combination of outlet water and silicon temperature is used for obtaining maximum clearing area. Computer simulated results are verified with the experimental results.