A Simple Optical Method for the Measurement of Glass Wool Fiber Diameter

An optical method for measuring glass wool fiber diameter has been proposed and discussed from the viewpoint of practical use. The method is based on both light scattering and light reflection on the glass wool. The method can measure the mean fiber diameter, d, in the area illuminated by laser light in realtime. The accuracy of the method, i.e., the dimensional resolution, was found to be about 0.7μm within the diameter range of d≤7.0μm

An optical system for monitoring torsion in a power transmission shaft in realtime

An optical system has been proposed and verified experimentally for monitoring the torsion of a power transmission shaft in realtime. The system consists of a pair of lasers, mirrors and light receivers as a sensor head, and logic circuit, high-frequency oscillator, and computer as a data processing system. The smallest measurable angle of torsion can be expressed by ω/ƒ, where ω is the rotational frequency of the power transmission shaft and ƒ is the frequency of the oscillator. The experimental error was found to be a few percentage points

Cloth Weft Densitometer Using a CCD Camera

A cloth weft densitometer has been proposed and its propriety verified by a preliminary experiment. The method is based on the counting of cloth wefts by a CCD camera with a shutter speed of 1 ms. The experiment shows that the densitometer can be used perfectly for many types of cloth if the cloth speed of less than approximately 10 m/min. The accuracy of the cloth-weft counting is above 99%, provided that the image contrast of the weft on the CCD camera is sufficiently high. Only 2-step digitations by the A/D converter is needed for 99% accuracy

Cloth Weft Densitometer Using a CCD Camera

A cloth weft densitometer has been proposed and its propriety verified by a preliminary experiment. The method is based on the counting of cloth wefts by a CCD camera with a shutter speed of 1 ms. The experiment shows that the densitometer can be used perfectly for many types of cloth if the cloth speed of less than approximately 10 m/min. The accuracy of the cloth-weft counting is above 99%, provided that the image contrast of the weft on the CCD camera is sufficiently high. Only 2-step digitations by the A/D converter is needed for 99% accuracy

Systemic dexmedetomidine augments inhibitory synaptic transmission in the superficial dorsal horn through activation of descending noradrenergic control:An in vivo patch-clamp analysis of analgesic mechanisms

α(2)-adrenoceptors are widely distributed throughout the central nervous system (CNS) and the systemic administration of α(2)-agonists such as dexmedetomidine produces clinically useful, centrally-mediated sedation and analgesia; however, these same actions also limit the utility of these agents (ie unwanted sedative actions). Despite a wealth of data on cellular and synaptic actions of α(2)-agonists in vitro, it is not known which neuronal circuits are modulated in vivo to produce the analgesic effect. To address this issue, we made in vivo recordings of membrane currents and synaptic activities in superficial spinal dorsal horn neurons and examined their responses to systemic dexmedetomidine. We found that dexmedetomidine at doses that produce analgesia (<10 μg/kg) enhanced inhibitory postsynaptic transmission within the superficial dorsal horn without altering excitatory synaptic transmission or evoking direct postsynaptic membrane currents. In contrast, higher doses of dexmedetomidine (>10 μg/kg) induced outward currents by a direct postsynaptic action. The dexmedetomidine-mediated inhibitory postsynaptic current (IPSC) facilitation was not mimicked by spinal application of dexmedetomidine and was absent in spinalized rats, suggesting it acts at a supraspinal site. Further it was inhibited by spinal application of the α(1)-antagonist prazosin. In the brain stem, low doses of systemic dexmedetomidine produced an excitation of locus coeruleus neurons. These results suggest that systemic α(2)-adrenoceptor stimulation may facilitate inhibitory synaptic responses in the superficial dorsal horn to produce analgesia mediated by activation of the pontospinal noradrenergic inhibitory system. This novel mechanism may provide new targets for intervention perhaps allowing analgesic actions to be dissociated from excessive sedation

Conception dates of Sika deer on the Boso Peninsula, central Japan

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Complete mode identification for resonance ultrasound spectroscopy

This study is devoted to deducing exact elastic constants of an anisotropic solid material without using any advance information on the elastic constants by incorporating a displacement-distribution measurement into resonant ultrasound spectroscopy (RUS). The usual RUS method measures free-vibration resonance frequencies of a solid and compares them with calculations to find the most suitable set of elastic constants by an inverse calculation.- This comparison requires mode identification for the measured resonance frequencies, which has been difficult and never been free from ambiguity. This study then adopts a laser-Doppler interferometer to measure the displacement-distribution patterns on a surface of the vibrating specimen mounted on pinducers; comparison of the measured displacement distributions with those computed permits us to correctly identify the measured resonance frequencies, leading to unmistakable determination of elastic constants. Because the displacement patterns are hardly affected by the elastic constants, an exact answer is surely obtained even when unreasonable elastic constants are used as initial guesses at the beginning of the inverse calculation. The usefulness of the present technique is demonstrated with an aluminum alloy and a langasite crystal.Hirotsugu Ogi, Keiji Sato, Takeyasu Asada, and Masahiko Hirao. Complete mode identification for resonance ultrasound spectroscopy. Journal of the Acoustical Society of America, 2002, 112(6), 2553. https://doi.org/10.1121/1.1512700

Hindered Diffusion of Asphaltenes at Elevated Temperature and Pressure Progress Report

During this past six months we continued our ongoing studies of the diffusion controlled uptake of coal and petroleum asphaltenes into a porous carbon catalyst. Toluene was used as the solvent for experiments at 20 C and 75 C while 1-methylnaphthalene was the solvent for the higher temperature experiments at 100 C, 150 C and 250 C. All runs were made at a pressure of 250 psi (inert He gas). Experiments were performed at 20 C and 75 C, for the petroleum asphaltene/toluene system. For the coal asphaltene/toluene system, experiments were performed at 75 C. Experiments were performed at 100 C, 150 C and 250 C for the coal asphaltene/1-methylnaphthalene system. A comparison between the experimental data and model simulated data showed that the mathematical model satisfactorily fitted the adsorptive diffusion of both the coal and petroleum asphaltenes onto a porous activated carbon. The adsorption constant decreases with an increase in temperature for both, the coal asphaltene/1-methylnaphthalene system as well as the petroleum asphaltene/toluene system. It was found that the adsorption constant for the coal asphaltene/toluene system at 75 C was much higher than that of the petroleum asphaltene/toluene system at the same temperature providing evidence of the greater affinity of the coal asphaltenes for the carbon surface. This could be due to the presence of more functional heteroatomic groups in the coal asphaltenes compared to their petroleum counterparts. Also during this time period, a new carbon catalyst support was prepared in our laboratory which will be used in adsorption experiments during the next phase of work