Image Intensified CCD Camera Research Articles

5.2: Invited Paper: Observation of the Spatiotemporal Variation of Wall Charge Distribution in an ac PDP Cell

AbstractWe measured the spatiotemporal wall charge distributions on sustain and address electrodes in an ac PDP cell using the longitudinal electro‐optic amplitude modulation method. The measured wall charge distributions are used together with the discharge images obtained using high speed, image intensified CCD camera to have a better understanding on the sustain as well as the address discharge occurring in a three electrodes, coplanar sustain discharge type ac PDP cell.

Photoelectron track image of capillary gas proportional counter

The segmented pixel gas detector has been developed with an optical imaging capillary gas proportional counter (CGPC) to obtain an image of an X-ray photoelectron track. The pixel signal is read out with an image-intensified CCD camera combined with the CGPC through the optical system of mirrors. Using the optical imaging CGPC with a penning gas mixture of Ar+8% CH4+2% TMA at 1atm, we have successfully detected clear images of photoelectron tracks for 22keV X-rays. The detection efficiency of the photoelectron track was approximately 95% for the images. The evaluated range of 5.2mm for 22keV X-ray photoelectron was consistent to the published ranges. The optical imaging CGPC with the high-resolution capability is available for an imaging type of X-ray polarimeter and for the field of medical science.

2-D Imaging of Soot Formation Process in a Transient Spray Flame by Laser-induced Fluorescence and Incandescence Techniques.

In order to inventigate the soot formation process in a diesel spray flame, simultaneous imaging of soot precursor and soot particles in a transient spray flame achieved in a rapid compression machine was conducted by laser-induced fluorescence (LIF) and incandescence (LII) techniques. 3rd harmonic (355nm) and fundamental (1064nm) laser pulses from single Nd : YAG laser, between which a delay of 44ns was imposed by 13.3m of optical path difference, were used to excite LIF due to soot precursor and LII due to soot particles separately in the spray flame. The LIF and the LII were separately imaged by two imageintensified CCD cameras with identical detection wavelength of 400nm and bandwidth of 80nm. The LIF due to soot precursor was mainly located in the central region of the spray flame between 40 and 55mm (270 to 370 times nozzle orifice diameter d0) downstream from the nozzle orifice. The LII due to soot particles was observed to surround the soot precursor LIF region and to extend downstream. First appearance of the LIF due to soot precursor in the spray flame preceded the appearance of the LII due to soot particles. The intensity of the LIF due to soot precursor reached its maximum immediately after rich premixed combustion. In contrast, the intensity of the LII due to soot particles increased gradually and reached its maximum after the end of injection. Measured LIF spectrum of the soot precursor in the spray flame was very broad and showed no apparent spectral structure.

Electrophoretic quantitation of nucleic acids without amplification by single-molecule imaging.

We have developed a novel high-performance quantitative assay for unamplified nucleic acids that is based on single-molecule imaging. The apparatus is a simple but highly sensitive single-molecule detection system that uses a normal CCD camera instead of an image-intensified CCD camera. After the DNA molecules in a sample were labeled with YOYO-1, they were induced to migrate electrophoretically in a polymer solution and imaged. No chemical or biochemical amplification was required. Direct quantitation of the sample by counting molecules was possible, because the number counted over the measurement period was directly proportional to the concentration of DNA molecules in the sample. Nonspecifically labeled impurities that would degrade the sensitivity of the assay were successfully reduced and discriminated from the DNA molecules by differences in electrophoretic mobility. By using beta-actin DNA (838 bp) as a model sample, we demonstrate that this protocol was fast (10-min measurement period), highly sensitive (limit of quantitation: approximately 10(3) copies/sample, or 3 x 10(-16) M), quantitative, and covered a wide linear dynamic range (approximately 10(4)). This high-performance assay promises to be a powerful technology for the quantitation of specific varieties of mRNA in the study of gene functions and diseases and in the clinical detection of mutant cells.

Optimization of laser-induced forward transfer process of metal thin films

The optimization of laser-induced forward transfer (LIFT) process using laser ablation of thin film and the evaluation of the dependence in laser spot size on the resolution of deposited material are reported. Ni thin film of several hundred of nanometer thickness, which is deposited on fused silica substrate, was irradiated by single pulse of KrF excimer laser (wavelength: 248 nm, pulse width: 30 ns), and transferred to a Si acceptor substrate. Images of the plume, which were photographed using image intensified CCD camera, indicated the cause of transfer of particles. The deposited material with clear contour was obtained under the condition that thin film was in contact with an acceptor substrate to inhibit the transfer of particles which were generated by laser irradiation. The resolution of a deposited material tended to be improved as the size of laser spot became smaller.

Laser-induced fluorescence imaging of the ocean bottom

A hyperspectral imaging system has been developed to im- age the laser-induced fluorescence of objects on the ocean floor to dis- criminate between man-made and natural materials. The information captured with this sensor allows one to examine the reflectance of the ocean floor, Raman scattering from water molecules, and laser-induced fluorescence from suspended chlorophyll and yellow matter in the ocean water and from objects on the ocean floor. The excitation laser is a Q-switched, diode-pumped, frequency-doubled Nd:YAG laser. The re- ceiver is a time-gated image intensified CCD camera with wide field-of- view optics designed for high radiometric throughput. A grating prism or GRISM placed before the receiver is used to spectrally disperse the returned light. The complete system forms a hyperspectral image of the laser-illuminated ocean floor. © 2001 Society of Photo-Optical Instrumentation En- gineers. (DOI: 10.1117/1.1385510) Subject terms: ocean imaging; laser-induced fluorescence; hyperspectral imag- ing.

1111 レーザ誘起蛍光法を用いた液滴火炎内OHラジカルの非接触計測(GS-6 燃焼(計測))

The planar laser Induced Fluorescence (PLIF) method was applied to visualize OH radical concentration distribution in a droplet flame. An Nd:YAG laser-pumped pulsed dye laser with frequency doubling was used to form a sheet of UV laser light, which excited the OH X^2Π→A^2Σ transition. The wavelength of the UV light was adjusted to 283.65nm. Fluorescence images of OH radical were taken by an image-intensified CCD camera. The OH radical was observed both inside the blue-flame zone formed below the droplet and outside the luminous zone of the droplet flame formed above the droplet.

Optical Analysis of Pulse Combustion Using Shadowgraph and Planar CH-LIF Imaging Technique

Planar imaging of laser-induced fluorescence of CH radical is made to examine combustion processes in a valveless pulse combustor. An excimer-pumped dye laser tuned to a wavelength of 387 nm is used to excite the R1N″=6 line of (0,0) band of the B2Σ−−X2Π system of CH radical, and an image-intensified CCD camera system is used to detect the (0,1) band emission at around 435 nm. According to the CH-LIF images, it is found that the progress in combustion during a pulsation period is expressed by the enlargement and breakup of the earlobe-shaped flame front along the outline of a pair of large-scale eddies of fresh mixture.

Development and performance characteristics of laser-induced fluorescence imaging lidar for forestry applications

A laser-induced fluorescence (LIF) imaging lidar was developed to monitor and measure the chemical activities and status of trees and forests. A unique feature of the lidar system was the usage and combination of a nano-second pulse laser and a gated image intensified CCD camera as an imaging detector. The system performance was checked using a ginkgo tree located at a distance of 60 m from the system. By operating the high sensitivity image intensifier with a short time duration of 100 ns, the LIF images of the tree were successfully obtained not only at night but also during the day. The ratio of the LIF image at 740 nm to that at 685 nm could be effective to estimate the chlorophyll concentration inside the leaves. It was shown that the system has the potential for macroscale monitoring of trees remotely and nondestructively.

504 非接触測定法を利用した燃料液滴に関する研究(GS-6 粒子・燃焼・流動解析)

Planer Laser Induced Fluorescence (PLIF) method was applied to visualize OH radical concentration distribution in the flame. A Nd:YAG laser-pumped pulsed dye laser with frequency doubling was used to from a sheet of laser light which excited the OH X^2Π→A^2Σ transition. The exited wavelength was 283.65nm. Fluorescence images and chemiluminescence images of OH radical were taken by a image-intensified CCD camera. The result showed that the OH radical was observed out of the outer edge in the premixed flame, the diffusion flame and droplet flame of n-hexadecane.

微弱スペクトルの高S/N比計測のための高効率2次元光子計数処理

An efficient two-dimensional photon counting procedure is described for high-S/N measurements of weak spectra using an image-intensified CCD camera. By using a procedure which utilizes the signal intensities of more than one pixel in judging a single photon detection, the photon detection efficeincy was increased by _??_40% in comparison with the method where a photon detection is based on the indensity of one pixel.

102高速回転している細菌べん毛のらせんピッチの観測

Many kind of bacteria swim in aqueous solution by rotating their helical flagellar filaments. Each filament is driven by a rotary motor (flagellar motor) embedded in the cytoplasmic membrane and can rotate very fast. The rotation speed reaches from 100 to more than 1000 r/sec. The possible deformation of such fast rotating flagellar filaments has not yet been observed because of difficulties mainly caused by their extremely small size. We tried to observe the deformation of the flagellar helices of swimming Vibrio alginolyticus cells with laser dark-field microscope. The laser dark-field image was recorded by using an image intensified CCD camera equipped with the electrical shutter. The change in the helical pitch was observed to be rather small, around 10%.

Ca2+ waves during triggered propagated contractions in intact trabeculae. Determinants of the velocity of propagation.

During triggered propagated contractions, Ca2+ waves travel along cardiac trabeculae with a constant velocity (Vprop) ranging from 0. 34 to 5.47 mm/s. To explore the determinants of Vprop, we studied (1) the relationship between [Ca2+]i and Vprop and (2) the effect of low concentrations of caffeine on Vprop. Trabeculae were dissected from the right ventricle of rat hearts. [Ca2+]i was measured using electrophoretically injected fura-2 and an image-intensified CCD camera. Force was measured using a silicon strain gauge, and sarcomere length was measured using laser diffraction techniques. After induction of reproducible Ca2+ waves by trains of electrical stimuli (2.5 Hz) at 21.9+/-0.2 degrees C, the number of stimuli or [Ca2+]o was varied in 9 trabeculae. In 5 trabeculae, the effects of caffeine (0.1 to 1.0 mmol/L) at [Ca2+]o of 2.2+/-0.3 mmol/L were determined. All images were recorded under stable conditions of wave propagation. The increment in [Ca2+]i during the last electrically stimulated transient (DeltaCaT) and [Ca2+]i just before onset of the Ca2+ waves (CaD) were used to estimate the Ca2+ loading of the sarcoplasmic reticulum (SR) and the myoplasm, respectively. The ratio (DeltaCaW/DeltaCaT) of the [Ca2+]i increment during the waves (DeltaCaW) to DeltaCaT was used to estimate the probability of opening of the SR-Ca2+ release channel during wave propagation. As a result of an increase of the number of stimuli or [Ca2+]o, Vprop increased in proportion to (1) DeltaCaT (r=0.82); (2) CaD (r=0.88); (3) DeltaCaW (r=0.85); and (4) DeltaCaW/DeltaCaT (r=0.74). The addition of caffeine (</=0.3 mmol/L) increased Vprop for any DeltaCaT and any DeltaCaW, revealing an increased sensitivity of Vprop to DeltaCaT and DeltaCaW. In contrast, caffeine had little effect on the relationship between Vprop and CaD and no effect on that between Vprop and DeltaCaW/DeltaCaT. These results suggest that both the cellular Ca2+ loading and open probability of the SR-Ca2+ release channels determine the velocity of propagation of Ca2+ waves.

An Antagonist of cADP-ribose Inhibits Arrhythmogenic Oscillations of Intracellular Ca2+ In Heart Cells

Oscillations of Ca2+ in heart cells are a major underlying cause of important cardiac arrhythmias, and it is known that Ca2+-induced release of Ca2+ from intracellular stores (the sarcoplasmic reticulum) is fundamental to the generation of such oscillations. There is now evidence that cADP-ribose may be an endogenous regulator of the Ca2+ release channel of the sarcoplasmic reticulum (the ryanodine receptor), raising the possibility that cADP-ribose may influence arrhythmogenic mechanisms in the heart. 8-Amino-cADP-ribose, an antagonist of cADP-ribose, suppressed oscillatory activity associated with overloading of intracellular Ca2+ stores in cardiac myocytes exposed to high doses of the beta-adrenoreceptor agonist isoproterenol or the Na+/K+-ATPase inhibitor ouabain. The oscillations suppressed by 8-amino-cADP-ribose included intracellular Ca2+ waves, spontaneous action potentials, after-depolarizations, and transient inward currents. Another antagonist of cADP-ribose, 8-bromo-cADP-ribose, was also effective in suppressing isoproterenol-induced oscillatory activity. Furthermore, in the presence of ouabain under conditions in which there was no arrhythmogenesis, exogenous cADP-ribose was found to be capable of triggering spontaneous contractile and electrical activity. Because enzymatic machinery for regulating the cytosolic cADP-ribose concentration is present within the cell, we propose that 8-amino-cADP-ribose and 8-bromo-cADP-ribose suppress cytosolic Ca2+ oscillations by antagonism of endogenous cADP-ribose, which sensitizes the Ca2+ release channels of the sarcoplasmic reticulum to Ca2+.

A203 放火現場における油性物の可視化

Liquid accelerants including kerosene, motor gasoline, and diesel fuel are often encountered in arson cases. The investigator must discover the presence of accelerants at the fire scene. Methods for their detection have been a subject of forensic interest. Visualization of a liquid accelerant at the fire scene was studied. Excitation and fluorescence spectra of liquid accelerants were measured. Broad fluorescence band in the spectral range between ultraviolet and shorter-wavelength region of visable were obtained when the excitation was performed in the ultraviolet spectral range. It is difficult to detect these fluorescenece by human eyes. An image intensified CCD camera was used to visualize the fluorescence of accelerants. The experimental results show the applicability of new method to detection of liquid accelerants at the fire scene.

Investigation of Local Behavior in a Turbulent Diffusion Flame by Rayleigh Scattering Image Velocimetry and OH Laser Induced Fluorescence.

Instantaneous and simultaneous measurements of two-dimensional temperature, velocity and OH concentration profiles by combining Rayleigh scattering image velocimetry (RIV) with OH laser induced fluorescence method (OH-LIF) were demonstrated in a turbulent nitrogen-diluted hydrogen (H2 30%+N2 70%) diffusion flame. This measuring technique mainly employed one double-pulsed Nd : YAG laser, one Nd : YAG pumped dye laser, and three image-intensified CCD cameras. OH concentration was measured quantitatively based on OH-LIF intensity and the calibration considering the OH-LIF quenching database. The strain rate along the flame surface (reaction zone of OH peak) was estimated by the velocity vectors and OH concentration profiles. The results obtained are as follows. (1) Local temperature and OH concentration depression in the flame tends to occur when the flame inclines toward the centerline and the strain rate becomes positive and high. On the other hand, the flame that has locally high temperature and OH concentration tends not to have positive and high strain rate. (2) When the flame surface is pushed outward by the lateral convection motion, the radial position of OH concentration peak tends to be located prominently outside of the temperature peak. Their profiles are much different from those of the laminar flame. The considerably high OH concentration as compared with the laminar flame was observed where the flame does not have positive and high strain rate.

Analysis of He‐Xe Discharge Kinetics in an AC PDP Cell

AbstractWe measured the time variation of 147nm VUV Xe*(3P1) resonance emission as well as the continuum from the He‐Xe discharge in a single surface discharge type AC PDP cell using an image intensified CCD camera. A detailed measurement of the resonance radiation exhibits a strong pressure broadening, fast rising to its peak and decay with multiple time constant. The decay time constants, relative intensities of resonance and dimer radiation change with the total gas pressure as well as the Xe content which implies that the collisional excitation, deexcitation and interlevel transition play important role in determining the VUV emission characteristics. We solved the He‐Xe discharge reaction equations together with the 2‐dimensional multi‐fluid equations for electron and ions to explain the experimental results and elucidate the dominant kinetic pathways which lead to the VUV emission in the AC PDP cells.

Imaging spectroscopy of the nonequilibrium shock front radiation in air

The nonequilibrium radiation of shock fronts in air is experimentally investigated by means of the imaging spectroscopy technique. Shock velocity ranges from 9.7 to 11.6 km/s and initial pressure from 13.3 to 41.6 Pa. The spectral diagnostic system consists of an imaging spectrograph, a streak camera, a gated image-intensified CCD camera and a personal computer for data acquisition/processing. This spectral diagnostic system is capable of simultaneous wavelength-, intensity- and time-resolved spectroscopic measurements in the nanosecond order. The image processing of the streak images includes a combined smoothing/deconvolution process in the time direction to diminish experimental noise effects and the temporal broadening due to the streak camera entrance slit. Wavelength range is chosen to investigate the first negative band of \( N_{2}^{+}\). “Large” and “slim” streak image types are observed. In the “large” streak images greater contribution from \(N_{2}^{+}\)(1-)(1,0) behind the radiation peak is observed. Experimental data are compared with a streak image numerically simulated. The numerical simulation agrees better with the “slim” streak image.

Laser-induced fluorescence studies of the biodistribution of carotenoporphyrins in mice.

The biodistribution of two recently developed tumour markers, trimethylated (CP(Me)3) and trimethoxylated (CP(OMe)3) carotenoporphyrin, was investigated by means of laser-induced fluorescence (LIF) after i.v. injection into 38 tumour-bearing (MS-2 fibrosarcoma) female Balb/c mice. At 3, 24, 48 or 96 h after administration, the carotenoporphyrin fluorescence was measured in tumoral and peritumoral tissue, as well as in the abdominal, thoracic and cranial cavities. The fluorescence was induced by a nitrogen laser-pumped dye laser, emitting light at 425 nm, and analysed by a polychromator equipped with an image-intensified CCD camera. The fluorescence was evaluated at 490, 655 and 720 nm: the second and third wavelengths represent the carotenoporphyrin (CP)-related peaks, whereas the first one is close to the peak of the tissue autofluorescence. The tumour and the liver were the two tissue types showing the strongest carotenoporphyrin-related fluorescence, whereas the cerebral cortex and muscle consistently exhibited weak substance-related fluorescence. In most tissue types, the fluorescence intensities decreased over time. A few exceptions were observed, notably the liver, in which the intensity remained remarkably constant over the time period investigated.

Toroidal transport studies in TEXTOR using lithium laser blow-off injection

The toroidal spread of laser blow-off injected lithium is studied. The temporal variation of the toroidal and radial distributions of the first two ionization stages of cross-field-injected lithium is measured around the injection location by a gated, image-intensified CCD camera. Broad atomic distribution and deep radial penetration of the injected beam is observed. The toroidal delay of the arrival of the Li+ ions is investigated by detecting the intensity of their line radiation at different toroidal positions away from the injection port. Possible explanations for the observations and the possible mechanism for the toroidal spread are discussed in detail. A comparison of the detected distribution of Li ions with a 1D simulation is presented.