• Journal of Power System Engineering
• /
• v.16 no.4
• /
• pp.5-11
• /
• 2012

There were some papers for diesel engine performance tests using BDF, but few article deals with the temperature and soot concentration of Bio diesel flame. Since the flame temperature of diesel engines is so high and change rapidly, an optical method for measurement of flame temperature is known as the most effective one. The two-color method regarding the visible wavelength radiation for the soot particles in flame was applied on Bio diesel flame in order to measure flame temperature and soot concentration in a diesel engine. Photo detecting device was newly designed and employed TSL250R, photo-diode, to pick-up the light information emitted from the combustion flame. As a result, real flame temperature T, as a flame brightness temperature, through Ta1, Ta2, were obtained and finally the characteristics of KL value as a soot concentration reveal the difference of combustion information between diesel fuel, blending oil and Bio diesel fuel oil.

• Proceedings of the KSRS Conference
• /
• 2003.11a
• /
• pp.351-353
• /
• 2003

We present a retrieval scheme for the remote sensing of evapotranspiration (ET) over rice paddy. To perform the retrieval, high-resolution airborne imagery of multi-spectral visible and thermal infrared data, and ground-based meteorological measurements are utilized. Our ET retrieval scheme is based on the basic principal of surface energy budget, which is a result of balance in longwave and shortwave radiation, latent heat, sensible heat, and energy flux into the ground. To partition the latent and sensible heat fluxes of interest from the energy balance equation, three basic parameters are of most concern, including albedo, surface temperature, and normalized difference vegetation index (NDVI). The NDVI and albedo can be easily derived from the visible and near infrared spectral data, while the surface tem-perature can be determined through the analysis of the infrared data with the Stefan Boltzmann law. From the airborne imagery taken on 28 April 2003, we observe very good dry and wet pixels that can be easily corre-sponded to the radiation and evaporation controlled crite-ria, respectively, and, hence, for the further use in defin-ing the evaporative fraction needed to partition sensible and latent heat fluxes from the net energy flux. The de-rived ET is compared with the in situ measurements.

• Journal of the Korean Society of Mechanical Technology
• /
• v.20 no.6
• /
• pp.770-775
• /
• 2018

In this study, the characteristics of muscle relaxation were analyzed by the experimental and numerical method. A skin tissue was produced by imitational biological tissue using the agar powder, saline solution and sugar. The tissue was exposed to three types of wavelength-blue visible radiation(410 nm), red visible radiation(635 nm), and infrared ray(830 nm). The temperature results along the depth of tissue were measured according to the variation of light wavelength and irradiation time. The temperature change of the tissue shown up similar pattern regardless of the light wavelength kinds. The wavelength of infrared ray penetrated strongly into tissue between 3.2 mm and 11.4 mm. Also, the temperature change with the irradiation time was small, and the temperature value of the infrared ray was the largest. As a result, the muscle relaxation will occur mainly at the infrared wavelength.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.1031-1033
• /
• 2013

Radiation protection, as well as finding the location of the radiation source, such as the Fukushima radiation leak accident, it is important for the early and safe disposal of nuclear accident. The three-dimensional position of the radiation source detection distance of the radiation source can provide additional information to the existing radiation detectors radiation of a two-dimensional position detection function and then it can play a decisive role in the radiation contaminant removal and decontamination work. In this research, three-dimensional semiconductor sensor based on dual radiation detectors radiation source device visible part of the research and development of efficient radiation sensor unit on the design of the shielding structure.The lightweight, high-efficiency radiation source locator implementation was attempted for the structure and thickness of the shielding and collimator to perform the simulation of the radiation shielding for the various parameters of the shape model through design the optimal structure of the MCNP-based heavy-duty tungsten shielding, lead shielding The results of this study, is a compact, lightweight three-dimensional radiation source detection and future of silicon - based sensors will be used in the study.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.2
• /
• pp.37-45
• /
• 2007

We have measured the spectral transmittances of UV blocking soft contact lenses, regular soft contact lenses and regular RGP lenses using the method suggested in ANSI Z80.20 standard. In order to evaluate visible light transmitting and UV blocking characteristics, we have calculated transmittances by integrating over the specific spectral ranges, i.e., visible light, UVA, UVB and UVC. We found that mean transmittances of visible light for all three categories were over 90.0 % which could be considered as within acceptable range for a contact lens. The transmittance of the UVA and UVB radiation for the UV blocking soft lenses except some cases was within UVR (Ultraviolet radiation) transmittance standard. The UV blocking ability of regular soft and RGP lenses was poor as rather expected. These results will be expected to assist clinical opticians and practitioners in utilizing the transmittance characteristics about the contact lens.

• Journal of the Korean Society of Radiology
• /
• v.12 no.3
• /
• pp.381-387
• /
• 2018

A Effect on physiological metabolism of microorganism which irradiated by visible light of non-ionization radiation(12,000 Lux) was investigated. The microorganism used in this experiment was a Rhodospirillum rubrum KS-301 of chemosynthetic microorganism. Batch fermentation of glucose were implement, and based on the data resulted from the fermentation. First, physiological characteristic of microorganism which was not irradiated was investigated. As a result, the decrease of the residual quantity of the substance(5.03 g/L - 2.17 g/L) was increased with the quantity of the bacteria(1.08 g/L - 3.14 g/L)and the quantity of the hydrogenous production(0.186 g - 0.3 g) respectively. Second, physiological characteristic of microorganism which was irradiated was investigated. As a result, the decrease of the residual quantity of the substance(13.17 g/L - 5.2 g/L) was increased with the quantity of the bacteria(4.7 g/L - 10.57 g/L)and the quantity of the hydrogenous production(0.186 g - 0.3 g) respectively. As the physiological characteristic of microorganism which was irradiated by visible light of non-ionization radiation(12,000 Lux) was active with its life, but the cell damages irradiated by with gamma-ray, X-ray, electron-ray in ionization radiation were appeared at cell.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.390-392
• /
• 2005

The digital radiation detectors are used clinically by diagnostic apparatus. However the digital radiation detector are some problem like high operating voltage, light blurring, low conversion efficiency, low fill factor, etc. Thus we propose a new radiation detector that the photoconductor layer and liquid crystal layer are coupled in sandwich structure. X-ray absorption in the photoconductor layer controls the state of the liquid crystal via creation of charge carrier and the light modulation of liquid crystal make image formation. The advantage of the new radiation detector is that high resolution image is acquired and the signal amplification is possible by external visible light source. In this study, we study the optical properties and electrical properties of the new radiation detector to irradiate X-ray. The Mercury Iodide($HgI_2$) was used by photoconductor material, and the aluminum is used by reflective layer. The thickness of Mercury Iodide is about $200{\mu}m$, the operating voltage of the liquid crystal is 1.5~5V. The electrical properties of Mercury Iodide was measured, and the transmission efficiency of liquid crystal was measured by modulation potential.

• Proceedings of the KSRS Conference
• /
• v.1
• /
• pp.430-431
• /
• 2006

KOMPSAT-2 was successively launched on July 28,06. She carries Fine Spatial Resolution Sensor with three channels. It is 4m monochromatic and 1m panchromatic. The main purposes would derive fine urban map and digital elevation model(DEM).Therefore we extend to coastal environment monitoring using the adjacent effect of radiation due to an interaction of radiation between heterogeneous surface and atmosphere. With data analysis of ASTER on TERA, which is 15m resolution in visible and near infrared wavelengths, we found atmospheric aerosols were always large. Note that data analysis was limited in Nagoya bay, Lake Tahoe, California & La Pozuelos, La Picasa, Argentina. Thus this time we expect data analyses around isolated island and peninsula in west and south coast of Korea.

• Fire Protection Technology
• /
• s.29
• /
• pp.39-45
• /
• 2000

All objects emit thermal radiation and this radiation is the basis of the techniques used to detect flames. The usual phenomena occurring in the initial stage of a fire are generally invisible products of a combustion and visible smoke. Liquid or gaseous materials do not undergo a smoldering stage such fires develop very rapidly. Also, the heat generated by the initial flames is usually not sufficient to active a heat detector. In this case the most effective criterion for automatic fire detection is the flame. In fire regulation of korea, the compulsory standard provided that a flame detector shall be installed a place of the attachment hight of detector is higher than 20 m, chemical plants, hangar, refinery, etc.. The result of the research and development are discriminated between a flame and other radiant emitters, developed PZT pyroelectric element is based on the use of photo-voltanic cell, developed IR band-pass filter that only allow a 4.3 radiation wavelength to reach the sensors and developed IR flame detector.

• Journal of the Korean Society of Radiology
• /
• v.13 no.3
• /
• pp.333-338
• /
• 2019

In the field of radiotherapy, the Quality Assurance(QA) procedure to verify the safety of treatment is considered to be very important. However, due to various problems of the conventional dosimeters used for the QA, researches on these dosimeters have been actively carried out to replace them. In this study, to maximize the sensitivity by visible light(VL) emitted from phosphors, blended hybrid sensors were fabricated by blending various weight percent(wt%) of $Gd_2O_2S:Tb$ which is a phosphor with excellent fluorescence efficiency into $PbI_2$. Then, the electrical properties to high energy radiation from the blended sensors and the pure $PbI_2$ sensor were compared and evaluated. As a result of the sensitivity evaluation, the sensor of 3wt% showed the highest value with more than 40% difference from the other sensors, and gradual decreasing in sensitivity was observed with increasing wt% except for the sensor of 3wt%. Also, in the reproducibility evaluation, the pure $PbI_2$ sensor exhibited a large variation in coefficient of variation(CV)>0.015, while all the blended sensors showed CV<0.015.