Transparent Acrylic Plate Research Articles

Improvisation of an Optical Pressure Sensor Based Dynamic Foot Pressure Measurement System

Dynamic foot pressure measurement is necessary particularly for diabetic patients to prevent ulcers, eventually leading to gangrene and amputation. The present work reports a low cost optical sensing system for the above, suitable for the Third World. It uses a horizontally placed transparent Acrylic plate with a webcam placed below facing upwards. A white paper, backed by a black adhesive plastic sheet, covered the whole plate on the top. Light from a tubular fluorescent lamp entered the acrylic plate from a side and traversed the thickness through total internal reflection. At points of pressure applied from the top, the air between the paper and the acrylic plate got displaced and caused breakdown of total internal reflection. The scattered light rays from the white sheet were recorded by the webcam. Computer software on Java platform was developed to grab and analyse video data to display dynamic pressure distribution in artificial colour contours. Approximate pressure calibration was obtained using static and dynamic values obtained from subjects with normal and abnormal foot pressures. Time graphs of pressure at user chosen points were also provided. The developed system worked with satisfaction and is being used for clinical assessment regularly. DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14687 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 51-58

Vision-Based Tactile Sensing and Shape Estimation Using a Fluid-Type Touchpad

In this paper, we propose a new method to estimate the shape and irregularity of objects by a vision-based tactile sensor, which consists of a CCD camera, LED lights, transparent acrylic plate, and a touchpad which consists of an elastic membrane filled with translucent red water. Intensities of red, green and blue bands of the traveling light in the touchpad are analyzed in this study to estimate the shape/irregularity of the object. The LED light traveling in the touchpad is scattered and absorbed by the red pigment in the fluid. The depth of the touchpad is estimated by using the intensity of the light obtained from the red-green-blue (RGB) values of the image, in consideration of the scattering and reflection effects. The reflection coefficient that depends on the shape of the membrane, was decoupled in the proposed formulation. The intensity of the traveling light is represented with the geometrical parameters of the touchpad surface. In order to reduce the approximation error caused by unmodeled factors, we compensate the error by using a function of the deformation of the membrane. The validation of the proposed method is confirmed through experimental results.

SU-E-J-164: Verification of Commercial Respiratory Tracking System Using Scintillation Screen.

The accuracy of the tracking system is critical for the result of four-dimensional radiation therapy. The objective of this study is to propose the method of verifying the accuracy of respiratory tracking system. The scintillation screen and the light marker between the transparent acrylic plates were designed to move according to the prerecorded respiratory organ motion of volunteers. A vertical circle photon beam with 3 cm diameters from the cyberknife unit was planned to track the motion of the scintillation screen with the plates. In dark room, the CCD camera outside of the phantom captured the scintillation from the screen and the light marker in 30 frames per second when the photon beam was incident. The pictures were captured by the CCD camera were analyzed frame by frame, and the discrepancy between the scintillating circle on the scintillation screen and the light marker depending on the time was measured. The discrepancy of the motions of the delivered photon beam and the light marker was analyzed. In the preliminary study, the maximum discrepancy was measured less than 1.5 mm in normal breathing pattern as the manufacturer specified it. As the speed of the motion was increased, the discrepancy between the position of the beam and internal marker increased. However, the error was clinically acceptable. The further study will be performed for the irregular respiratory motion patterns. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (20110004848).

522 黒色漆の透明感評価

This paper describes about an appearance evaluation of black color. A high-quality black color has depth. However, it is still not clear why we feel the depth of black color. Moreover, a measurement method of the depth of black color is not established yet. A black rhus lacquer is a Japanese traditional black color. And that is known as a high-quality black color. We suppose that a transparency of the rhus lacquer is higher than that of the chemical paint. It may be a reason why we feel depth when see a rhus lacquer finish. Therefore we chose the black lacquer as the object of the study. We made the sample which painted with the black rhus lacquer on a transparent acrylic plate, and checked transparency and translucency of the sample. As a result, it was shown that a light penetrated the black rhus lacquer. The light that had a long wavelength was easy to penetrate the sample, and transmitted light looked like red color. In the case of a CCD camera for the near infrared light, the diffusion light from a background of the sample was detected. The long wavelength light is extremely feeble, but this light is possibly related to a visual quality of the black rhus lacquer.

Effect of working-fluid filling ratio and cooling-water flow rate on the performance of solar collector with closed-loop oscillating heat pipe

This study experimentally investigated the effect of the working-fluid filling ratio (FR) and the cooling-water flow rate (CWFR) on the top heat loss and the performance of a solar collector equipped with a closed-loop oscillating heat pipe (CLOHP). The CLOHP was composed of a heating section, a cooling section, and an adiabatic section; it had a 0.002-m internal diameter and eight turns. The heating section was attached to a copper plate coated with black chrome, which absorbed energy from a solar simulator that had 12 halogen lamps and was controlled by a voltage regulator. The cooling section was inserted into the collector’s cooling box, which was made of a transparent acrylic plate. The FR of the working fluid ranged from 30% to 80% with a 10% interval, and the CWFRs were 0.15 l/min, 0.30 l/min, and 0.45 l/min. The experimental results show that the solar collector equipped with the CLOHP has good performance at working-fluid FRs of 60% and 70% with low flow rates of 0.15 l/min and 0.30 l/min.

Miyake-Apple view of inner side of sclerotomy during microincision vitrectomy surgery

To examine the inner surface of the sclerotomy during microincision vitrectomy surgery by Miyake-Apple view. The anterior half of porcine eyes was attached to a transparent acrylic plate with cyanoacrylate glue. Then, either a 23-gauge or a 25-gauge trocar-cannula was inserted through the sclera obliquely. The inner surface of the entrance site was observed posteriorly by Miyake-Apple view. These images were compared with the endoscopic view of two patients who underwent vitreous surgery for an epiretinal membrane. When the trocar-cannula was inserted obliquely, the Miyake-Apple view showed that the ciliary epithelium at the sclerotomy site was stretched. When the trocar-cannula was inserted vertically, the ciliary epithelium was folded, and the folds remained even after the trocar was removed. Vitreous strands were seen incarcerated into the sclerotomy site. In human eyes, a folding of the ciliary epithelium was not clearly seen with the endoscopic view but the incarcerated vitreous was seen. The Miyake-Apple view provided a precise, in vivo, observation of the inner surface of the entry site. It disclosed the morphological stress on the ciliary epithelium by the sclerotomy.

Compressive characteristics of foam-filled composite egg-box sandwich panels as energy absorbing structures

This paper describes compressive tests on foam-filled composite egg-box panels which were carried out to assess their performance as energy absorbers. Material type, number of plies and stacking angle were varied. Stacking sequences of CFRP [0] n T, CFRP [45] n T ( n = 3, 4) and GFRP [0/90] S , [±45] S were used for foam-filled egg-box cores. Fracture modes of representative composite egg-box cores without foam, including crack initiation and propagation, were observed and analysed by multiply-interrupted compressive tests using transparent acrylic face plates on both sides of the egg-box core. The concept of premature buckling of the foam-filled egg-box panels is used to explain the small initial stress peak. Finally, the collapse curve of the core was used to estimate energy absorption capacity. It was found that the foam-filled composite egg-box sandwich panels had a good energy absorption capacity with a stable collapse response resembling the ideal energy absorber.

Titanium Oxide Film Deposition on Acrylic Resin by Atmospheric TPCVD

A dye-sensitized solar cell (DSC) is a solar cell that uses an anatase film as a photovoltaic device. Since the anatase film and dye play the roles of electron carrier and electron generator, respectively, in the DSC, porous anatase films are desirable. In this paper, in order to develop a low-cost fabrication process for the photovoltaic device of the DSC, photocatalytic titanium oxide film deposition was carried out by atmospheric thermal plasma CVD. Ar gas, which served as the working gas for the plasma jet and substrate, and a 20 × 40 × 3 mm transparent acrylic resin plate were used. Titanium tetra iso butoxide was used as feedstock. Consequently, by cooling the substrate, an anatase-dominant film could be deposited at 773 K in deposition temperature without meltdown of the substrate on the condition of 100 mm in deposition distance, even in the case of acrylic resin substrate use. By wettability and methylene-blue decoloration tests, it was confirmed that the film showed hydrophilic and decolored methylene blue perfectly by 8-h UV irradiation. Furthermore, the DSC in which the titanium oxide film deposited by this technique was included as a photovoltaic device generated a photoelectromotive force of 25 mV. From these results, these thermal plasma processes were found to have high potential for DSC fabrication.

Simulations of an Optical Tactile Sensor Based on Computer Tomography

In order to create a robotic tactile sensor of thin shape, a new optical tactile sensor is developed by applying a CT (Computer Tomography) algorithm. The present tactile sensor is comprised of infrared emitting diode arrays, receiving phototransistor arrays and a transparent acrylic plate and a black rubber sheet with projections. Infrared rays emitted from the diode array are directed into one end of the plate and their intensity distribution is measured by the phototransistor array mounted on the other end. If the CT algorithm is directly applied to the tactile sensor, there are two shortcomings: the shape of the sensing area is limited to a circular region and there is a long calculation time. Thus, a new CT algorithm oriented to tactile sensing is proposed for overcoming these problems. In the present algorithm, a square sensing area is divided into an N-by-N array and algebraic equations are derived from the relationship between the input and output light intensities on the assumed light projections. Several reconstruction methods are considered for obtaining pressure values caused in the squares. In the present study, the ART (Algebraic Reconstruction Technique) and LU decomposition methods were employed, and these methods were compared to select the best reconstruction method. In a series of simulations, it was found that the LU decomposition method held an advantage for the present type of tactile sensor because of its robustness against disturbance and short calculation time.

Carbon Balance and Flower Quality of Bud-Cut Carnations during Flower Bud Opening under Elevated Photosynthetic Photon Flux Density

Carbon balance and flower quality of post-harvest flower bud opening (FBO) were studied in cut shoots of the standard red carnation ‘Francesco’. For each FBO treatment, six ‘tight bud’ - cut carnations were placed in a ventilated transparent cylindrical container, separated into two compartments (flower heads, 25±1°C, 85±5% RH and leaves/stems, 23±1°C, 95±5% RH) by a transparent acrylic plate under continuous light with a PPFD of 30 (P30), 90 (P90) or 150 (P150) μmol m-2 s-1 with the cut ends in flower opening solution (25 mg L-1 AgNO3, 200mg L-1 8-hydroxyquinoline citrate, and 30g L-1 sucrose) . The time required for FBO was reduced for higher PPFD for Experiment A (8.0 d in P30, 7.0 d in P90, and 6.0 d in P150, respectively) and Experiment B (6.0 d in P30, 5.0 d in P90, and 5.0 d in P150, respectively) . The mean flower quality scores of opened carnations after FBO closely correlated with total carbon uptake (TCU) with correlation coefficients of 0.94 and 0.98 during 10-d flower quality evaluation for Experiments A and B. Carbon from net CO2 exchange per stem (CNCE) and carbon from gross photosynthesis (CGP) of leaves/stems in P150 was greater than those in P90 and P30.

습식 마늘박피 시스템 개발 (I) - 고압 플런저 펌프와 부채꼴 분사노즐을 이용한 박피 실험 -

This research was conducted to test the feasibility of utilizing high-pressure water jets of over 1.0㎫ as a means of breaking and peeling garlic bulbs. High-pressure plunger pumps and flat-spray nozzles of varying orifice diameters and spray angles were utilized to supply water jets into a prototype peeling chamber made of transparent acrylic plates. Water jets were discharged from a total of six nozzles installed in such a way that three parallel nozzles face the other three. The cross-sectional area of the peeling chamber and the installation angle of the nozzles had critical effects on peeling performance. Small cross-sectional area was required so that total impact force of water jets on garlic could be increased. The optimum installation angles were around 4, 8, and 16<TEX>$^{\circ}$</TEX> for the nozzles having 15, 40, and 65<TEX>$^{\circ}$</TEX> spray angles, respectively. Best performance with 61.4% of completely-peeled garlics was obtained at a pressure of 1.94㎫ and a flow rate of 9.07 <TEX>$\ell$</TEX>/min for each nozzle. The peeling efficiency of the system was generally unsatisfactory due to the limited flow rate of the plunger pumps utilized. For better performance, it is recommended to increase flow rate while reducing operating pressure by utilizing other type of pumps.

A Root Box Method to Estimate Virulence of Helicobasidium mompa Using Carrots and Its Comparison with the Conventional Method Using Apple Stocks

A root box method with carrots was developed to estimate virulence of the violet root rot fungus, Helicobasidium mompa, to facilitate short-term screening of many isolates during a year. The root box consisted of two transparent acrylic plates and a plastic bag of vermiculite in which two taproots of carrot were growing and inoculated with the fungus growing on fragments of mulberry twigs. The boxes were kept in a greenhouse at 25°C, and the surface of carrots was observed weekly up to 14 weeks. The virulence of each isolate was determined based on the number of weeks after inoculation required for the fungus to develop infection cushions on the surface of carrots. Results were compared with those from the conventional inoculation method using apple stocks. Two-year-old 456 apple stocks were planted with or without fungal inoculum in 30-cm diam. plastic pots containing commercial soil and placed outdoors in April 1999. Symptoms on plant tops were observed weekly, and the first stocks were killed 14 weeks after inoculation. At the end of trial 1 (6 months) and trial 2 (14 months), apple stocks were dug up to rate disease index (DI) based on hyphal growth and infection cushion formation on the stem base. There was variability in disease severity among replicates as well as isolate variability ; however, the results were similar in both trails. The level of virulence estimated by both methods was almost parallel for a total of 23 isolates from five plant species, except for two isolates from sweet potato that formed no obvious infection cushion on apple roots but on carrot were the most virulent.

1401 噴霧液滴群の衝突に関する研究(GS-7・8・9 動力エネルギーシステム(1))

It is difficult to catch the small water-droplets less than about φ20μm by using the inertia force type air-water separators, e.g. wire-mesh demister, eliminator. Therefore, it is important for entering water-droplets to be made larger for improving the separation performance. This paper describes the effect of spray-spray impingement, whether being changed more large droplets or more minute ones. The horizontal duct with a cross-section of 200mm×200mm and length of 1,600mm are made larger, maximum 1.4 times, as compared with the larger ones, used here is made of the transparent acrylic plate and in this duct the water-droplets sprayed from the two air-atomizing nozzles impinge each others. The experimental parameters are the atomizing pressure, the atomizing distance and the impingement angle. As a result of this experiment, especially the small water-droplets less than φ10μm are made larger, maximum 1.4 times, as compared with the larger ones.

Genotypic Variations in Response of Lateral Root Development to Fluctuating Soil Moisture in Rice

Developmental plasticity in lateral roots may be one of the key traits for the growth of rice plants under soil moisture fluctuations. We aimed to examine responses in seminal root system development to changing soil moisture for diverse rice cultivars. Special attention was paid to the two different types of lateral roots ; the generally long, thick L type capable of branching into higher orders, and the non-branching S type. Plants were grown in half-split polyvinyl chloride tubes fixed with transparent acrylic plate for root observation under glasshouse conditions. When plants were grown first under drought conditions, then rewatered, the seminal root system development in terms of dry weight and total length was promoted as compared with plants grown under continuously well-watered conditions in IR AT 109 and Dular, drought tolerant cultivars. Promoted production of L type lateral roots mainly contributed to the development of the longer seminal root system. Plants exposed to soil submergence before they were grown under drought conditions did not show such promoted responses in these two cultivars. However, in KDML 105, a drought tolerant cultivar, the production of especially L type laterals was substantially promoted under drought and rewatered conditions. Honenwase was characterized by the shallow root system and great reduction in root system length when soil moisture becomes limited. These facts show that genotypic variations exist in the plastic response of rice seminal root system and that the L type lateral root plays a key role in manifestation of this plasticity.

An accurate adjustable applicator for magnetic resonance imaging-based stereotactic procedure using the Leksell G frame.

An applicator system for the Leksell G frame was constructed to enable accurate placement of the frame for stereotactic magnetic resonance imaging (MRI) and successful stereotactic surgery. The applicator prevents inaccurate placement of the fiducial box on the patient's head and prevents contact of the frame holder with the patient's shoulder while in the MRI unit. It also helps to ensure optimal positioning of desired targets within the three-dimensional stereotactic space defined by the frame. The applicator is made of transparent acrylic plates, which simulate the fiducial box that is attached to the frame for the preoperative stereotactic MRI study. An air cuff at the top supports the frame at any desired height and makes minute adjustments possible. Side cuffs help to keep the frame at the desired position from right to left. Indicators attached to the frame for the anterior fiducial plate prevent potential contact of the plate with the anterior posts and help avoid a poor fit caused by bending of the frame from excessive torque on the cranium fixation screws. Indicators for the MRI frame holder on the foot screws predict potential collision of the holder with the patient's shoulder before actually applying the holder on the frame. The applicator shows the range and limits of the Leksell stereotactic arc. This applicator system has been used effectively in more than 89 MRI-based functional stereotactic procedures. These include pallidotomy, thalamotomy, implantation of deep brain stimulators, and implantation of depth electrodes. It has functioned well and has facilitated excellent operative results in these cases. This simple frame applicator eliminates the need for reapplication of the stereotactic frame and additional imaging studies, thus providing successful and appropriate frame placement for stereotactic surgery.

A new method for continuous measurement of regional cerebral blood flow using laser Doppler flowmetry in a conscious rat

We have developed a new system to continuously measure regional cerebral blood blow (rCBF) in the cortex of a conscious animal. For this purpose, we used rats and laser Doppler flowmetry. Under pentobarbital anesthesia, the animal's skull was opened making a small square hole 3 mm × 3 mm in size. A transparent acrylic plate was placed over the hole in the skull. A polyethylene cannula (inner diameter 1.0 mm, length 5.0 mm) was fixed on the plate as a guide for the laser Doppler flowmeter (LDF) probe (outer diameter 1.0 mm, length 5.5 mm). Both the plate and guide cannula were fixed to the skull by dental cement. Every day for the following two weeks after surgery, the conscious animal was placed in a hammock for recording rCBF. A LDF probe was freely attachable to the plate above the cortex via the guide cannula during measurement of rCBF. The rats were kept in a hammock with their legs firmly touching the floor during measurement of rCBF. It was possible to measure rCBF every day for about two weeks, and rCBF responded consistently to inhalation of 7% CO 2 when the responses were expressed as percentages of the prestimulus control rCBF values. This system is recommended for the continuous measurement of rCBF in a conscious animal.

A time-saving thin-layer chromatography plate-scraping system

A system for efficiently scraping thin-layer chromatography plates is described. A height-adjustable rack for holding the thin-layer chromatography plate is constructed of transparent acrylic plate. The base provides a surface on which to slide vial holders and also gives stability to the rack. The plate is scraped with a single-edge razor blade cut to an appropriate width and the scrapings fall into a polypropylene funnel which sits on a vial that is in either a test tube rack or a cassette from a scintillation counter. The plate-scraping system reduces scraping time by more than 60% and increases the accuracy of results.