Shutter Type Research Articles

Application of thermotropic ferroelectric liquid crystals in electrical vehicle

This intermediate phase between solid and liquid enables liquid crystal engineers for various interesting yet fascinating thermo-optical applications. One such application of exploited for electric vehicle safety is optical shutter realized using thermotropic liquid crystals. Optical shutters are essential components in various optical systems, in providing control over the transmission of visible light. These shutters are categorized into various types of mechanical shutters, electro-optical shutters, liquid crystal optical shutters (LCOS) etc. liquid crystal cells and polarizing elements to quickly change the transmittance of light, making them ultimate for applications such as imaging and precision illumination. In this work, we explored the experimental techniques, key specifications, features, and applications of an optical shutter developed using liquid crystalline material LCOS.

Preparation of a double-layer liquid crystal optical shutter with fluorescent properties and its ultraviolet shielding screening properties

ABSTRACT Polymer dispersed liquid crystal (PDLC) films and polymer-stabilised cholesteric liquid crystals (PSCLC) films have been widely applied in smart optoelectronics due to electrical switching properties. In this study, fluorescent dyes were introduced into PDLC films and combined with PSCLC films to invent a new type of optical shutter, and the optimal formulations of each of liquid crystal structural layers were investigated. Then, PDLC anti-counterfeit optical device doped with fluorescent materials were fabricated by UV curing method using polymerisation-induced phase separation. The novel optical shutter could be driven layer by layer at room temperature according to different voltages to realise the switching of three states, namely, off state, PDLC layer-driven, and full-driven (open state). Samples under optimal conditions showed that the new optical shutter could achieve 96.5% UV shielding in the off state and had a long lifetime. The results demonstrate the attractive potential of the new optical shutter for optoelectronic devices and smart curtain applications.

Thermal hydraulic performance of a tubular heat exchanger with in‐line perforated baffle with shutter type saw tooth turbulator

AbstractThis experimental investigation aimed to analyze the impact of a unique design of swirl generator airflow on the performance of a tubular heat exchanger operating with axial flow. To conduct the experiment, we utilized a custom‐built apparatus containing eight sawtooth air deflectors with differing space height ratios (e/h). These deflectors were oriented in a uniform manner (shutter type) and positioned at various inclination angles. Circular baffle plates, housing these deflectors, were equidistantly spaced at different pitch ratios. The arrangement of tubes within the heat exchanger remained constant throughout the study, while the Reynolds number ranged from 16,000 to 30,000. In addition, a consistent heat flux condition was maintained on the surface of the tubes. The research outcomes indicated that incorporating a deflector baffle plate with an inclination angle of 30°, an e/h ratio of 0.4, and a pitch ratio of 1.2 led to an average increase of 1.36 in the thermal enhancement factor when compared to a heat exchanger lacking a baffle plate, tested under similar conditions.

The effect of triangular shutter type flow deflector perforated baffle plate on the thermofluid performance of a heat exchanger

AbstractThe study aimed to investigate the heat transfer (HT) properties of a tubular heat exchanger (HX) by using innovative baffle plate arrangements. The newly designed baffle plate was circular with triangular openings and adjustable triangular flow deflectors. These deflectors were strategically placed at the inlet of the HX to create a swirling flow downstream. Three baffle plates were installed along the flow direction with different length‐to‐diameter ratios (pitch ratios) to assess their impact on HT, pressure drop, and thermal enhancement factor. The study compared these results with a smooth channel under varying Reynolds numbers (16,500–29,500). The findings revealed that both the pitch ratio (0.6–1.2) and the inclination angle of the deflectors (30⁰–50⁰) significantly affected the HX's performance. Notably, the baffle plate with a deflector inclination angle of 30° and a pitch ratio of 1 showed a remarkable average improvement of 36.5% compared to other angles and ratios.

Optimising UAV Data Acquisition and Processing for Photogrammetry: A Review

Unmanned aerial vehicles (UAVs) are used to acquire measurement data for an increasing number of applications. Photogrammetric studies based on UAV data, thanks to the significant development of computer vision techniques, photogrammetry, and equipment miniaturization, allow sufficient accuracy for many engineering and non-engineering applications to be achieved. In addition to accuracy, development time and cost of data acquisition and processing are also important issues. The aim of this paper is to present potential limitations in the use of UAVs to acquire measurement data and to present measurement and processing techniques affecting the optimisation of work both in terms of accuracy and economy. Issues related to the type of drones used (multi-rotor, fixed-wing), type of shutter in the camera (rolling shutter, global shutter ), camera calibration method (pre-calibration, self-calibration), georeferencing method (direct, indirect), technique of measuring the external images orientation parameters (RTK, PPK, PPP), flight design methods and the type of software used were analysed.

A Practical Comparison of Beam Shuttering Technologies for Pulsed Laser Micromachining Applications.

In this report we investigate the performance of various beam shutter technologies when applied to femtosecond laser micromachining. Three different shutter options are considered: a mechanical blade shutter, a bistable rotary solenoid shutter, and an electro-optic modulator (EOM) shutter. We analyzed the behavior of each shutter type during repeated open/close commands (period of 10 ≤ T ≤ 200 ms) using both high-speed videography and practical micromachining experiments. To quantify the performance at varying cycle periods, we introduce a new variable called the compliance that characterizes the average state of the shutter with respect to its intended position. We found that the solenoid shutter responds poorly to sequential commands. The mechanical shutter provides reliable performance for cycled commands as short as T = 40 ms, but begins to lag significantly behind the control signal for T ≤ 20 ms. The EOM shutter provides the most precise and reliable performance, with an opening time of only 0.6 ms and a high compliance with the signal commands, even when cycled very quickly (T = 10 ms). Overall, this study acts as an extensive practical guide for other laser users when considering different shutter options for their laser system and desired application.

Early Age Properties of High-Performance Concrete

High Performance Concrete is used to not only minimize the environmental footprint of the cement and concrete industry, but also to enable the design and rapid construction of taller and more slender structures. Despite the significant change in concrete property requirements, the properties of concrete as used during design of concrete structures are mostly still based on 28-day water cured compressive strength, stiffness, long term drying shrinkage and creep. The relevance of these measured properties on the actual behaviour of the structure should be questioned as high strength concrete is known to have low water/cement ratios resulting in significant early age shrinkage, which is currently not taken into account by designers. This paper is based on a study where the early age properties of concrete was investigated, with specific focus on the first 24 hours after casting. The effect of factors such as low water/cement ratio, admixtures, ambient and material temperatures, shutter type and cast volume on properties such as setting time, early age shrinkage, strength development and stiffness was studied and observed trends discussed in this paper.

Semiconductor quantum well based shutters for NIR laser mode-locking with ∼ GHz repetition rate

Fast semiconductor shutters based on coupled wells were designed in the search for reliable, compact and cheap key element of GHz repetition rate NIR lasers passive mode-locking. Stable 0.98 GHz repetition rate 200-fs Yb:KYW laser pulses were demonstrated for SESAM including semiconductor reflector and a layer of quantum wells. The damage threshold estimate for the SESAM is ∼ 8.87 mJ/cm2. Other type of shutter – DSAM – was developed with dielectric reflector and the layer of quantum wells transferred over reflector. The measured recovery time was about 2-3 ps for both types of saturable absorbers. The efficiency relative to the incident pump power was 57% for the SESAM and 19% for the DSAM. Average output power of 2.54 W for the all-semiconductor shutter (SESAM) and of 0.92 W for the dielectric mirror with a saturable absorber (DSAM) were obtained. Actual state of the art for the shutters design is considered.

High-Conversion Efficiency Pulse Compression by Stimulated Raman Scattering and Laser Induced Breakdown in Water

A novel temporal pulse compression technique, combining stimulated Raman scattering (SRS) and laser induced breakdown (LIB) principles was presented in this work, which employing an energy controllable dual-cell setup. As a novel type of plasma shutter, the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> cell was used to transmit the high-power peak at the leading pulse edge and successfully block its low-power tail. The effect resulted in a 7 ns pulse duration from a Nd: YAG laser compressed into 330 ps, the pulse compression ratio was about 21×. The magnified optical power of the leading edge diminished the threshold of SRS and improved the beam quality of the output pulse. In addition, the output energy of Stokes was approximately 2 times than that of the 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> cell process, and the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> cell process increased the energy conversion efficiency from 4.2% to 15.8%. Thus, the 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> -order Stokes SRS was greatly improved, and the 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nd</sup> -order Stokes SRS was more easily generated. The method provided a simple but convenient way to generate a short pulse with a high energy conversion efficiency Raman laser.

Determining optimal photogrammetric adjustment of images obtained from a fixed‐wing UAV

AbstractPhotogrammetry with unmanned aerial vehicles (UAVs) has become a source of data with extensive applications. The accuracy is of utmost significance, yet the intention is also to find the best possible solutions for data acquisition in economic terms. The objective of the research was the analysis of various variants of the bundle block adjustment. The analysis concerns data which is diversified with respect to the type of shutter (rolling/global), the measurement of external orientation elements, the overlap and the number of ground control points (GCPs).

Calibration of Timing Parameters of Still Image Cameras and Video Cameras by a Two Dimensional LED Array

This paper presents a t wo-dimensional 10 x 10 LED array system developed in-house at t he Standards and Calibration Laboratory (SCL) for the calibration of timing parameters of still image cameras and video cameras. In this paper, the circuit design and the calibration methods for cameras of different shutter types (rolling shutter or global shutter) are presented. This LED array may also be used to verify the shutter type of cameras. The frequency of the clock signal applied in the calibration is traceable to the SI through the cesium beam frequency standard maintained at SCL.

50.2: Invited Paper: Characterization of Co‐Fabricated Silicon TFT and MEMS Shutter Display

Active matrix shutter type displays consisting of thin film transistors and pre‐stressed micro‐electro‐mechanical elements that were co‐fabricated in simple and robust four or five mask processes exhibit a unique combination of attractive features such as excellent optical characteristics, fast switching time and outstanding operating temperature range.

Falling behavior and control effect on temperature rise under heating condition concerning water film flow on steel shutter surface

Falling behavior and control effect on temperature rise under heating condition concerning water film flow on steel shutter surface

Robust estimation of simulated urinary volume from camera images under bathroom illumination.

General uroflowmetry method involves the risk of nosocomial infections or time and effort of the recording. Medical institutions, therefore, need to measure voided volume simply and hygienically. Multiple cylindrical model that can estimate the fluid flow rate from the photographed image using camera has been proposed in an earlier study. This study implemented a flow rate estimation by using a general-purpose camera system (Raspberry Pi Camera Module) and the multiple cylindrical model. However, large amounts of noise in extracting liquid region are generated by the variation of the illumination when performing measurements in the bathroom. So the estimation error gets very large. In other words, the specifications of the previous study's camera setup regarding the shutter type and the frame rate was too strict. In this study, we relax the specifications to achieve a flow rate estimation using a general-purpose camera. In order to determine the appropriate approximate curve, we propose a binarizing method using background subtraction at each scanning row and a curve approximation method using RANSAC. Finally, by evaluating the estimation accuracy of our experiment and by comparing it with the earlier study's results, we show the effectiveness of our proposed method for flow rate estimation.

P-209L:Late-News Poster: Pseudo Gate Doubling Method for Increasing Charging Time in High Resolution Shutter Type Stereoscopic 3D LCD TVs

P-209L:<i>Late-News Poster</i>: Pseudo Gate Doubling Method for Increasing Charging Time in High Resolution Shutter Type Stereoscopic 3D LCD TVs

Gas phase ion chemistry of an ion mobility spectrometry based explosive trace detector elucidated by tandem mass spectrometry

The gas phase ion chemistry for an ion mobility spectrometer (IMS) based explosive detector has been elucidated using tandem mass spectrometry. The IMS system, which is operated with hexachloroethane and isobutyramide reagent gases and an ion shutter type gating scheme, is connected to the atmospheric pressure interface of a triple quadrupole mass spectrometer (MS/MS). Product ion masses, daughter ion masses, and reduced mobility values for a collection of nitro, nitrate, and peroxide explosives measured with the IMS/MS/MS instrument are reported. The mass and mobility data together with targeted isotopic labeling experiments and information about sample composition and reaction environment are leveraged to propose molecular formulas, structures, and ionization pathways for the various product ions. The major product ions are identified as [DNT–H]− for DNT, [TNT–H]− for TNT, [RDX+Cl]− and [RDX+NO2]− for RDX, [HMX+Cl]− and [HMX+NO2]− for HMX, [NO3]− for EGDN, [NG+Cl]− and [NG+NO3]− for NG, [PETN+Cl]− and [PETN+NO3]− for PETN, [HNO3+NO3]− for NH4NO3, [NO2]− for DMNB, [HMTD–NC3H6O3+H+Cl]− and [HMTD+H–CH2O–H2O2]+ for HMTD, and [(CH3)3CO2]+ for TATP. In general, the product ions identified for the IMS system studied here are consistent with the product ions reported previously for an ion trap mobility spectrometer (ITMS) based explosive trace detector, which is operated with dichloromethane and ammonia reagent gases and an ion trap type gating scheme. Differences between the explosive trace detectors include the [NG+Cl]− and [PETN+Cl]− product ions being major ions in the IMS system compared to minor ions in the ITMS system as well as the major product ion for TATP being [(CH3)3CO2]+ for the IMS system and [(CH3)2CNH2]+ for the ITMS system.

Effects of weight balance on a 3D TV shutter type glasses: Subjective discomfort and physical contact load on the nose

A two-phase experimental study examined the effects of weight balance in 3D TV shutter type glasses by subjective discomfort and physical contact load on the nose. Four 3D glasses with different weight-concentrated locations (Front, Middle, Ear, and Rear) and one Reference glasses were investigated. Subjective discomfort ratings on the overall, nose, and posterior edge of the ear were obtained using a 100 point visual analogue scale, and physical load on the nose was measured by force sensing resistor (FSR) film sensors. The overall and nose discomforts for Front were significantly higher than other conditions; the ear discomfort for Ear was significantly worse than the others. The nose load for Front (0.34 N) was significantly higher than Middle (0.22 N), Ear (0.20 N), Rear (0.16 N), and Reference (<0.05 N). A correlation analysis presented that the overall and nose discomforts were closely related (r > 0.9) to the nose load. Relevance to IndustryEffects of weight balance in 3D TV shutter type glasses were examined in terms of subjective discomfort and physical nose load. Overall discomfort and physical nose load significantly declined while the weigh-concentrated location moved from the front to the rear of temples.

A Comparative Analysis of the Energy Performance of Traditional Wooden Shutters and Contemporary Aluminium Roller Shutters in Istanbul, a Case Study

Windows are one of the most important components of the building envelope from which several high level performance requirements are expected. Some of these performances are contradictory with each other which increase the importance of the design and material selection of windows. Natural lighting and thermal performance are examples for the contradictions in window design. Usually when transparency is increased in windows the thermal conductivity of the system is also increasing which decrease the overall thermal performance of the window. Shutters are the components of a window which is mainly used to control the natural lighting through a window system. Another important benefit from the shutters may be its contribution to overall thermal performance of the window systems. As a Mediterranean country several types of traditional window shutters have evolved in Turkey. Istanbul is the historical and economical capital city of Turkey and wooden vertical pivoted shutters are the most common type of shutters in the traditional wooden Istanbul houses. There is also a growing trend in the usage of vertical PU filled aluminium roller shutters in these kinds of houses. Two houses using each other type of shutters are examined in 2012 for determining the most efficient type of shutters in terms of energy usage. An inventory analysis is introduced, a comparative assessment of embodied and operational CO2 emissions on the two case houses’ windows is realized and the results are presented in this paper.

Technical issues that affect the use of retrofit panel thermal shutters in commercial buildings

Retrofit insulated window shutters are examined. An initial investigation reveals that internal shutters are more viable in this context. Condensation is identified as a potential risk. Extensive investigations using modelling software as well as site and laboratory experiments are described which demonstrate that this risk is low. The thermal effectiveness of internal shutters is modelled and laboratory tested. Practical application: This article results from research into the possibility of creating a retrofit thermal shutter system for existing commercial buildings. Building on earlier research, the paper examines whether this type of shutter is best fixed externally or internally to existing brick clad buildings and concludes that the latter is the best strategy. It then examines whether condensation between existing glazing and the outer shutter face is a problem and finds that this is not a significant issue. The way is clear for the development of this type of system as an alternative to costly triple glazing solutions.

Determination of Optimal Location of Circuit Board and Battery on 3D Glasses by Considering Nose Load and Subjective Discomfort

The current shutter type (SG) 3D glasses in the market are heavy (41 g) and have a poor weight balance due to a battery and a circuit board on the temples of the glasses. Therefore, it causes high pressure on the nose and discomfort for the users. This study determined the optimal location of a circuit board and a battery for SG type 3D glasses. Four 3D glasses with different weight distributions (the battery and the circuit board locations: front, middle, ear, and rear positions) were employed in the experiments. Subjective discomfort ratings (100 point scale) around the nose and the posterior edge of the ear were obtained after wearing the four 3D glasses. Also, at the same time the load on the nose was measured by using FSR (force sensing resistor) film sensors. As a result, the front position showed the highest subjective discomfort rating on the nose. Discomfort ratings on the nose were decreased significantly as the location of the battery and circuit board moved backward on the temples (p = 0.0009). On the other hand, the ear position showed the highest subjective discomfort rating on the posterior edge of the ear, and, as opposed to the nose, the subjective discomfort ratings for the posterior edge of the ear tended to increase as the battery and circuit board moved backward (p = 0.0093). The highest nose load, 0.34 N, was found on the front position, and the load on the nose was decreased significantly as the location of the battery and circuit board moved backward (p &lt; 0.001). Also, the nose loads had a strong correlation with the discomfort ratings on the nose ( Radj2 = 99.1%), but no strong correlation was found with the subjective discomfort ratings on the posterior edge of the ear ( Radj2 = 19.6%). Consequently, the middle position was recommended as the optimal location of the battery and circuit board on the temples of the SG type 3D glasses by considering the above results.