CCD Camera System Research Articles

Increase of Process Stability of Sheet Metal Hydroforming due to Feed Back Control

Sheet metal hydroforming of single sheets is a deep drawing process. In contrast to deep drawing with rigid tools, an active fluid medium performs the forming operation. The process is chiefly influenced by the control of the clamping force against the increasing fluid pressure. Although the optimum force-pressure progression is close to the sealing line, it is initially unknown and dependent on different system parameters. To perform the process at the ideal curve, the system parameters need to be detected online and led back to the feed back control unit. An optical system is used for the detection of the sealing state. The detection system is a CCD-camera system that allows for the continuous recording of occurring leakages. Acquired data permit the application of different strategies to control the forming process along the sealing line. This paper provides an overview of this developed technology, advantages and problems with regard to the process stability and performance, the parts quality, and recent results comparing control strategies.

Measurement of contaminant removal from skin using a portable fluorescence scanning system

The residence time of particulate contamination on the human body is a factor that has an important impact on the accuracy of exposure assessment in the aftermath of an accidental release of radionuclides to the atmosphere. Measurements of particle clearance from human skin were made using an illumination system to excite fluorescence in labelled silica particles and a CCD camera and image processing system to detect this fluorescence. The illumination system consists of high-intensity light emitting diodes (LEDS) of suitable wavelengths arranged on a portable stand. The physically small size of the LEDs allows them to be positioned close to the fluorescing surface, thus maximising the fluorescent signal that can be obtained. The limit of detection was found to be 50 μg of tracer particle per cm 2. Experiments were carried out to determine the clearance rates of 10 μm and 3 μm particles from the skin. Results show that, in the absence of any mechanical rubbing of the skin, the clearance of particles from the skin followed an approximately exponential decay with a half-time of 1.5–7.8 h. Skin hairiness and degree of human movement were found, in addition to particle size, to have an important influence on particle fall-off rate.

Performance validation of an improved Xenon-arc lamp-based CCD camera system for multispectral imaging in proteomics

Advances in gel-based nonradioactive protein expression and PTM detection using fluorophores has served as the impetus for developing analytical instrumentation with improved imaging capabilities. We describe a CCD camera-based imaging instrument, equipped with both a high-pressure Xenon arc lamp and a UV transilluminator, which provides broad-band wavelength coverage (380-700 nm and UV). With six-position filter wheels, both excitation and emission wavelengths may be selected, providing optimal measurement and quantitation of virtually any dye and allowing excellent spectral resolution among different fluorophores. While spatial resolution of conventional fixed CCD camera imaging systems is typically inferior to laser scanners, this problem is circumvented with the new instrument by mechanically scanning the CCD camera over the sample and collecting multiple images that are subsequently automatically reconstructed into a complete high-resolution image. By acquiring images in succession, as many as four different fluorophores may be evaluated from a gel. The imaging platform is suitable for analysis of the wide range of dyes and tags commonly encountered in proteomics investigations. The instrument is unique in its capabilities of scanning large areas at high resolution and providing accurate selectable illumination over the UV/visible spectral range, thus maximizing the efficiency of dye multiplexing protocols.

HIGH-CONTRAST NEUTRON IMAGING TO OBSERVE WATER DISTRIBUTION IN INTACT PLANTS

Low energy neutron radiography has good contrast with respect to water concentration when tested with a several plant materials. Therefore, this method is suitable for detection of small changes in water distribution in intact plants. In this study, low energy neutron beams of cold neutron (CN) and very cold neutron (VCN) ports at Kyoto University Reactor (KUR), and the VCN port at Institute of Laue-Langevin (ILL) reactor were used respectively. Low energy neutron radiography images were obtained with a cooled CCD camera system and an imaging plate. Using low energy beams at the ILL reactor, relatively small water changes in thin leaves during rehydration were observed. The transmission thickness was limited because of the low energy. From the computed tomographic (CT) images of cut carnation flowers obtained using beams from the VCN port at KUR it was observed that the calyx diameter was about 10mm. The total time to construct a CT image composed of 180 2D images was 3.5 h.

Dynamic imaging with a triggered and intensified CCD camera system in a high-intensity neutron beam

When time-dependent processes within metallic structures should be inspected and visualized, neutrons are well suited due to their high penetration through Al, Ag, Ti or even steel. Then it becomes possible to inspect the propagation, distribution and evaporation of organic liquids as lubricants, fuel or water. The principle set-up of a suited real-time system was implemented and tested at the radiography facility NEUTRA of PSI. The highest beam intensity there is 2 × 1 0 7 cm - 2 s - 1 , which enables to observe sequences in a reasonable time and quality. The heart of the detection system is the MCP intensified CCD camera PI-Max with a Peltier cooled chip (1300×1340 pixels). The intensifier was used for both gating and image enhancement, where as the information was accumulated over many single frames on the chip before readout. Although, a 16-bit dynamic range is advertised by the camera manufacturers, it must be less due to the inherent noise level from the intensifier. The obtained result should be seen as the starting point to go ahead to fit the different requirements of car producers in respect to fuel injection, lubricant distribution, mechanical stability and operation control. Similar inspections will be possible for all devices with repetitive operation principle. Here, we report about two measurements dealing with the lubricant distribution in a running motorcycle motor turning at 1200 rpm. We were monitoring the periodic stationary movements of piston, valves and camshaft with a micro-channel plate intensified CCD camera system (PI-Max 1300RB, Princeton Instruments) triggered at exactly chosen time points.

Analysis of Mitotic and Expression Properties of Human Neocentromere-based Transchromosomes in Mice

Human neocentromeres are functional centromeres that are devoid of the typical human centromeric alpha-satellite DNA. We have transferred a 60-Mb chromosome 10-derived neocentric marker chromosome, mardel(10), and its truncated 3.5-Mb derivative, NC-MiC1, into mouse embryonic stem cell and have demonstrated a relatively high structural and mitotic stability of the transchromosomes in a heterologous genetic background. We have also produced chimeric mice carrying mardel(10) or NC-MiC1. Both transchromosomes were detected as intact episomal entities in a variety of adult chimeric mouse tissues including hemopoietic stem cells. Genes residing on these transchromosomes were expressed in the different tissues tested. Meiotic transmission of both transchromosomes in the chimeric mice was evident from the detection of DNA from these chromosomes in sperm samples. In particular, germ line transmission of NC-MiC1 was demonstrated in the F1 embryos of the chimeric mice. Variable (low in mardel(10)- or NC-MiC1-containing embryonic stem cells and chimeric mouse tissues and relatively high in NC-MiC1-containing F1 embryos) levels of missegregation of these transchromosomes were detected, suggesting that they are not optimally predisposed to full mitotic regulation in the mouse background, particularly during early embryogenesis. These results provide promising data in support of the potential use of neocentromere-based human marker chromosomes and minichromosomes as a tool for the study of centromere, neocentromere, and chromosome biology and for gene therapy studies in a mouse model system. They also highlight the need to further understand and overcome the factors that are responsible for the definable rates of instability of these transchromosomes in a mouse model.

1116 エバネッセント光を用いた表面近傍におけるコロイド粒子の濃度測定(要旨講演,マイクロメカトロニクス)

This study aims at visualization of the bio-molecules dissolved in the solution near the surface using evanescent wave light. A system was developed for the visualization, which consists of total reflection fluorescent microscopy, Intensified CCD camera and PIV image processing system. Brownian motion of particle with diameter of 100nm and the concentration near the wall was evaluated. Furthermore, to evaluate the effects of the wall, surfaces with hydrophilic and hydrophobic wettability are prepared. The results show that the wall effects on the average displacement of Brownian motion and concentration profile of the particles. It is suggested that interaction between surface and particles are effective for the Brownian particles. The technique is applicable for bio-molecules analysis.

Modeling and Testing the Fracture Process of Impregnated Carbon-fiber Roving Specimens During Bending: Part II – Experimental Studies

Unidirectional carbon fiber–epoxy composite specimens were produced and three-point bending tests were carried out at spans of 10 and 80 mm. During the tests images were taken using a CCD camera system and the type of damage was studied. The fracture process of unidirectional composite beams were modeled during the 3P bending test considering the beam built up of elementary embedded-fiber layers considered as E-type fiber bundle cells using the formulae developed in the first part of this paper. The fracture processes obtained by measurements were compared to the modeled expected value processes completed with deviation field or confidence interval.

Spectrometric measurements in laryngeal cancer

Objectives: Direct and indirect autofluorescence endoscopy of the larynx have proven to facilitate the detection and delineation of precancerous lesions, carcinoma in situ and cancer. The aim of the study is to evaluate spectrometric changes during autofluorescence examination in laryngeal dysplasia and cancer. Methods: In a prospective study, 42 patients with suspected precancerous or cancerous lesions were investigated during microlaryngoscopy. Autofluorescence was induced by filtered blue light (375–440 nm) of a xenon short arc lamp and processed by a CCD camera system (D-light-AF-system). Autofluorescecne images were gathered in a contact mode. For spectrometric measurements, an optical multi channel analyzer (AVS-USB200) was applied. Results were compared to pathohistological findings. Results: Autofluorescence spectra of normal laryngeal mucosa demonstrated peaks at 475, 510, 550, 600, and 630 nm. Highest intensity was observed in the green spectrum resulting in green autofluorescence images. In precancerous and cancerous alterations of the mucosa the autofluorescence signal changed from green fluorescence to a reddish-violet color. Highest loss of intensity was observed at 510 nm. Conclusions: According to our results, the autofluorescence spectroscopy of the larynx seems to be a promising diagnostic tool for the early detection of laryngeal cancer and its precursor lesions. A difference between precancerous and cancerous laryngeal mucosa could not be detected. Scarring, marked hyperkeratosis and inflammation can limit the predictive value of the method.

Biophoton detection as a novel technique for cancer imaging.

Biophoton emission is defined as extremely weak light that is radiated from any living system due to its metabolic activities, without excitation or enhancement. We measured biophoton images of tumors transplanted in mice with a highly sensitive and ultra-low noise CCD camera system. Cell lines employed for this study were AH109A, TE4 and TE9. Biophoton images of each tumor were measured 1 week after carcinoma cell transplantation to estimate the tumor size at week 1 and the biophoton intensity. Some were also measured at 2 and 3 weeks to compare the biophoton distribution with histological findings. We achieved sequential biophoton imaging during tumor growth for the first time. Comparison of microscopic findings and biophoton intensity suggested that the intensity of biophoton emission reflects the viability of the tumor tissue. The size at week 1 differed between cell lines, and the biophoton intensity of the tumor was correlated with the tumor size at week 1 (correlation coefficient 0.73). This non-invasive and simple technique has the potential to be used as an optical biopsy to detect tumor viability.

The drying process of concrete: a neutron radiography study

The natural drying process of concrete, which has a significant effect on its characteristics, for example durability, was studied at the neutron radiography facility at SAFARI-1 nuclear research reactor, operated by Necsa. Monitoring of the movement of the water in concrete samples, which were wet cured for one day and covered on all the sides but one, was done by means of a CCD camera system. In this paper the methodology in observing the drying process will be described together with results obtained from this investigation. The measured water content and porosity results were quantified and compared reasonably well with conventional gravimetrical measurements.

High-energy and thermal-neutron imaging and modeling with an amorphous silicon flat-panel detector

The Los Alamos Neutron Science Center (LANSCE) operates two spallation neutron sources dedicated to research in materials science, condensed-matter physics, and fundamental and applied nuclear physics. Prior to 1995, all thermal neutron radiography at Los Alamos was done on a beam port attached to the Omega West reactor, a small 8 MW research reactor used primarily for radioisotope production and prompt and delayed neutron activation analysis. After the closure of this facility, two largely independent radiography development efforts were begun at LANSCE using moderated cold and thermal neutrons from the Target-1 source and high-energy neutrons from the Target-4 source. Investigations with cold and thermal neutrons employed a neutron converter and film, a scintillation screen and CCD camera system, and a new high-resolution amorphous silicon (a-Si) flat-panel detector system. Recent work with high-energy neutrons ( E n>1 MeV) has involved storage-phosphor image plates. Some comparison high-energy images were obtained with both image plates and the a-Si panel and showed equivalent image quality for approximately equal exposure times.

Fluorescence imaging in vivo: raster scanned point-source imaging provides more accurate quantification than broad beam geometries.

Two fluorescence imaging systems were compared for their ability to quantify mean fluorescence intensity from surface-weighted imaging of tissue. A broad beam CCD camera system was compared to a point sampling system that raster scans to create the image. The effects of absorption and scattering in the background tissue volume were shown to be similar in their effect upon the signal, but the effect of the three-dimensional shape of the tissue was shown to be a significant distortion upon the signal. Spherical phantoms with Intralipid and blood for absorber and scatterer were used with a fixed concentration of aluminum phthalocyanine fluorophore to illustrate that the mean intensity observed with the broad beam system increased with size, while the mean intensity observed with the raster scanned system was not as significantly affected. Similar results were observed in vivo with mice injected with the fluorophore and imaged multiple times to observe the pharmacokinetics of the drug. The fluorescence in the tumor observed with the broad beam system was higher than that observed with the raster scanned system. Based upon the phantom and animal observations in this study, it should be concluded that using broad beam fluorescence imaging systems to quantify fluorescence in vivo may be problematic when comparing tissues with different three dimensional characteristics. In particular, the ratio of fluorescence from tumor to normal tissue can yield inaccurate results when the tumor is large. However, similar measurements with a narrow beam system that is raster scanned to create the images are not as significantly affected by the three dimensional shape of the tissue. Raster scanned imaging appears to provide a more uniform and accurate way to quantify fluorescence signals from distributed tissues in vivo.

In vivo Imaging of Biophoton Originating from Malignant Tumor with using a Highly Sentive CCD Camera System

In vivo Imaging of Biophoton Originating from Malignant Tumor with using a Highly Sentive CCD Camera System

Mechanism of apoptotic resistance of human osteosarcoma cell line, HS-Os-1, against irradiation

In our previous study, we examined reactive oxygen species (ROS) formation in T lymphocytes following 5 Gy of irradiation. Using a CCD camera system, we monitored fluorescence in T lymphocytes loaded with the succinimidyl ester of Dichlorodihydrofluorescein diacetate (H2DCFDA), which is non-fluorescent until oxidized by ROS. We found that ROS formation occurred immediately after irradiation, continued for several hours, and resulted in oxidative DNA damage. Therefore, the origin of the hyper-radiosensitivity of T lymphocytes seemed to be the high production of ROS in the mitochondrial DNA following irradiation. In this study, we examined radiation-induced ROS formation, oxidative DNA damage, early apoptotic changes, and mitochondrial membrane dysfunction in the human osteosarcoma cell line HS-Os-1, which was established from an osteoblastic tumor that arose in the left humerus of an 11-year-old girl and was already morphologically characterized in vitro and in vivo. We found that ROS formation and oxidative DNA damage were actually scarcely seen after irradiation of up to 30 Gy in these cells; that mitochondrial membrane potential was preserved; and that apoptotic changes were not demonstrated despite the relatively high-dose irradiation of 30 Gy. Therefore, the origin of the close similarity of radiosensitivity between adult articular chondrocytes and the human osteosarcoma cell line HS-Os-1, is considered to involve the low degree of ROS formation following irradiation; the similarity possibly results from the strong scavenging ability of these two kinds of cells for free radicals including hydroxyl radicals.

Measurement and Modeling of Drop Absorption Time for Various Ink-receiver Systems

An ink jet instrument was used to measure the drop absorption time of various ink-receiver systems. The drop absorption time is defined as the time required for the receiver to completely absorb the impinging ink drop, i.e., the drop totally penetrates into the receiver and disappears from the receiver surface. The instrument consists of a piezo printhead with drive electronics, a stage for receiver support, a strobe light, a CCD camera, imaging optics, and image capture system. The drops ejected from the printhead have a volume of about 25 pL and a velocity of about 5 m/sec. The receivers used in the measurements include both non-porous and porous receivers. Results indicate that nonporous receivers with swellable polymeric coatings have much longer drop absorption time (>30 sec) than those receivers with porous coatings (∼33-100 msec). The difference in drop absorption time between non-porous and porous receivers can be ascribed to the basic difference in the physical mechanisms of ink penetration into the receiver, i.e., diffusion of ink in the polymeric receiver versus capillary flow of ink in the porous receiver. Based on these physical phenomena, simple one-dimensional models have been developed to describe the drop absorption process in the non-porous and porous receivers. The dependence of drop absorption time on the volume of ink drop and physical properties of ink, such as viscosity and surface tension, and receiver, such as diffusion coefficient and porosity, was also derived. Comparison of model results with experimental data are presented and discussed.

Autofluorescence videoendoscopy for photodiagnosis of head and neck squamous cell carcinoma.

The diagnosis of head and neck squamous cell carcinoma is usually made by visual identification. Searching for a non-invasive optical diagnostic method with the ability to detect the precancerous lesions or second primary tumors earlier in high-risk populations led to the development of photodiagnosis by autofluorescence (AF) endoscopy. The aim of the present study was to evaluate and discuss the diagnostic potential of autofluorescence videoendoscopy as a complementary visual aid in the routine endoscopic diagnosis of head and neck cancers. In a prospective study, 48 patients underwent white light (WL) videoendoscopy followed by AF technique at the Institute of Gustave-Roussy from November 2001 to August 2002. Of 48 patients, 30 had suspected precancerous or cancerous laryngeal lesions, 7 presented benign laryngeal lesions, while 8 showed pharyngeal and 3 oral tumors. All detected lesions were evaluated by histological examination. AF was induced by filtered blue light of a xenon short arc lamp and processed by a CCD camera system (D-Light AF System; Storz, Tuttlingen, Germany). Normal laryngeal mucosa displayed a typical green fluorescence signal. Moderate and severe epithelial dysplasia, carcinoma in situ and invasive carcinoma showed a diminished green fluorescence and presented a marked reddish-blue color. In case of hyperkeratosis a bright white color was detected. Some benign lesions, such as granulomas, polyps and papillomas also displayed altered green fluorescence. Autofluorescence videoendoscopy for photodiagnosis of head and neck squamous cell carcinomas has proved to be a method of high specificity and good sensitivity. Two additional precancerous lesions that were invisible at the WL examination but detected with the AF technique show its potential role in the regular screening procedure or follow-up examination in a high-risk population. It was a very helpful complementary visual aid for the intraoperative control of the surgical margins after per oral endoscopic resection.

Probing Titan’s lower atmosphere with acousto-optic tuning

Narrow-band images of Titan were obtained in November 1999 with the NASA/GSFC- built acousto-optic imaging spectrometer (AImS) camera. This instrument utilizes a tunable filter element that was used within the 500- to 1050-nm range, coupled to a CCD camera system. The images were taken with the Mount Wilson 2.54-m (100 in.) Hooker telescope, which is equipped with a natural guide star adaptive optics system. We observed Titan at 830 and 890 nm and at a series of wavelengths across the 940-nm window in Titan’s atmosphere where the methane opacity is relatively low. We determined the absolute reflectivity (I/F) of Titan and fit the values at 940 nm to a Minnaert function at Titan’s equator and at −30° latitude (closer to the subsolar point) and obtained average values for the Minnaert limb-darkening slope, k, of 0.661 ± 0.007 and 0.775 ± 0.018, respectively. Comparison with models suggests that the equatorial value of k is consistent with rain removal of haze in the lower atmosphere. The higher value of k at −30° is consistent with the southern hemisphere being brighter than the equator. However, the fits are not unique. The data and models at 890 are consistent with no limb brightening or darkening at this wavelength either at the equator or at −30°.

Optical study of the features of the streamer images in RPC

Optical images of the streamer from a Resistive Plate Chamber (RPC) are observed using a transparent high-voltage electrode in the operation of streamer mode. The optical images are measured using CCD camera system in mixture Ar/C4H10 with and without C2H2F4. Area of typical streamer image is approximately 12mm2 in both gas mixtures with its surrounding halo of 2–4mm in diameter. We also observed the quenching effect of C4H10 and C2H2F4 on the optical image in the chamber.

Comparison of radiation-induced reactive oxygen species formation in adult articular chondrocytes and that in human peripheral T cells: Possible implication in radiosensitivity

Previously, we examined the formation of reactive oxygen species (ROS) in T lymphocytes following 5 Gy of irradiation. Using a CCD camera system, we monitored fluorescence in T lymphocytes loaded with the succinimidyl ester of dichlorodihydrofluorescein diacetate (H2DCFDA), which is non-fluorescent until oxidized by ROS. We found that ROS formation occurred immediately after irradiation, continued for several hours, and resulted in oxidative DNA damage. Therefore, the origin of the hyper-radiosensitivity of T lymphocytes seemed to be the high production of ROS in the mitochondrial DNA following irradiation. In this study, we examined radiation-induced ROS formation in adult articular chondrocytes, which were demonstrated to be highly resistant to apoptosis in our previous study. We found that ROS formation was actually scarcely seen after irradiation of up to 20 Gy in these cells. Therefore, the origin of the great difference of radiosensitivity between T lymphocytes and adult articular chondrocytes is considered to lie in the degree of ROS formation following irradiation, with this difference possibly resulting from the scavenging acuity of these two kinds of normal tissue cells for free radicals including hydroxyl radicals.