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Some laboratory tests showed rather strange hysteresis loops in strain–temperature space, where the strains were measured with a strain gauge on the surface of a wet cubic rock sample under a subzero temperature cycle. This report gives introductory remarks and the first result on a new project launched by the present authors. The project is intended to make clear the major mechanisms responsible for the unexpected hysteresis loops in the strain–temperature diagram, in which an abrupt increase in strains appeared at a halfway point of the cooling process at higher cooling rates. The hysteresis loops suggest that various thermal and mechanical (or physical) phenomena take place within the rock sample; some possible candidates of causes behind the phenomena are discussed and a hypothesis associated with them is proposed. Furthermore, to separate an unexpected part of the hysteresis loop from its “regular” part, thermal strains on the surface of a spherical sample under a temperature cycle are calculated wit...

Kinetics of dissolution of quartz, its solubility and a heavy phase formation in Na2CO3 and NaOH solution under temperature 100°C, 200°C and 320°C and filling of autoclaves at 76% and 79% were studied. The etching surface of quartz bars after the runs is characterized. For the evaluation of entrapped solid inclusions and water-bearing nonstructural contaminations against the growth rate of quartz crystals, the accelerated method was developed.

The growth simulations of synthetic quartz crystals grown on seeds with industrialized sizes and orientations were shown on the procedure by means of the setting of virtual lengths between the seed center and principal crystal faces to be grown. The virtual lengths needed for simulations are calculated on the given sizes and shapes of seeds, X-bar, Y-bar and rectangular Z-plate. The simulations of growth processes are executed as a function of growth time under the model values of growth rates on principal crystal faces, m, R, r, Z, and the so-called S. By the comparison of geometrical sizes of as-grown crystal faces with simulated faces, the growth rates of principal faces are quantitatively evaluated in the commercially produced quartz crystals grown from the rectangular Z-plate seeds. The growth rates of R- and r-faces at the upper and lower sides of grown crystals show somewhat different values which may be due to the direction of convection flow in autoclave.

The fundamental solutions were obtained for step-like point forces acting in three orthogonal directions and an instantaneous fluid point source in a fluid-saturated, porous, infinite solid of transversely isotropic elasticity and permeability. After expressing the governing equations in the form of matrix in the Laplace space, we employed Kupradze's method together with the triple Fourier transforms. This method reduces the simultaneous partial differential equations with respect to three displacement components and a pore fluid pressure to a differential equation in terms of only one potential scalar function, which can be operationally solved in the transformed space. After the Laplace inversion of the potential, the residue theorem was applied to its Fourier inverse transform with respect to one of the transformation variables. The Fourier transforms with respect to two other variables were rewritten into the Hankel transforms. Copyright © 2002 John Wiley & Sons, Ltd.

To elucidate the genotypic and phenotypic characteristics of autosomal dominant polycystic kidney disease (ADPKD) in Japanese populations, we performed a comprehensive search for mutations in PKD1 and PKD2 in 180 Japanese ADPKD patients from 161 unrelated families. We identified 112 (89 PKD1 and 23 PKD2) mutations within 135 families. Patients with PKD2 mutations account for 23.6% of all Japanese ADPKD families in this study. Seventy-five out of the 112 mutations have not been reported previously. The estimated glomerular filtration rate (eGFR) decline was significantly faster in patients with PKD1 mutations than in those with PKD2 mutations (-3.25 and -2.08 ml min(-1) year(-1) for PKD1 and PKD2, respectively, p 0.01). These results indicate that mutations within PKD1 and PKD2 can be linked to most of the cases of Japanese ADPKD, and the renal function decline was faster in patients with PKD1 mutations than in those with PKD2 mutations also in the Japanese ADPKD. We also found that PKD2 mutations were more frequent in Japanese ADPKD than that in European or American ADPKD.

We have identified two genes coding for chloroplast ribosomal protein L12 encoded in the nuclear genome of rice (Oryza sativa). These genes were designated rpl12-1 and rpl12-2 (rpl12, ribosomal protein L12). Northern analysis with specific probes revealed that both genes are transcribed. The expression of each gene seems to have a different regulatory machinery. It is also suggested that the expression of rpl12-1 is controlled in an organ-specific manner. The deduced amino-acid sequences of the mature peptide parts are more conserved than those of the transit peptide parts in both monocotyledonous and dicotyledonous plants. A phylogenetic tree was constructed using the nucleotide sequences of the transit peptide region of the rpl12s of reported plant. The tree includes estimates of when the transit peptides were acquired, and when the genes were duplicated, in the course of evolution. According to our hypothesis, the nuclear-translocated chloroplast ribosomal protein L12 gene obtained its transit peptide after the divergence of monocots and dicots, then gene duplications occurred independently in monocots and dicots, and subsequently rice and rye branched apart.

On synthetic quartz crystals, quantitative evaluation about the correlation between peaked cobbles and dislocations with screw component was investigated. This correlation provides capability of nondestructive evaluation for dislocation density by cobble density. The authors developed a system to observe the cobbles effectively. It can be used for industrial field.

Quantitative evaluation of correlation between cobble structure and linear defect density was investigated. The linear defect means dislocation and etch channel in this report. Rough estimation of linear defect density is obtained by measuring peaked large cobble density. The possibility of non-destructive evaluation of linear defect density in synthetic quartz crystals is discussed.

Lattice defects in synthetic quartz crystals grown from various rotated Y-cut seed plates are studied. Dislocation density, OH/sup -/ concentration (alpha value), Al and Na concentrations, and other information are discussed in this paper. The states of these lattice defects included in each grown crystal are changed by their seed orientation.

The authors studied the measurement method of alpha values on synthetic quartz, to solve the discrepancy of grade evaluation between different wavenumbers that is involved in IEC 60758 second edition 1993-04, and to minimize alpha value difference between different measuring instruments. The solution is proposed in this paper. Those are proper instrument calibration, standard samples and the values, and new alpha grade table. The result can be applied to Fourier Transform Infrared Spectrometer (FTIR).

Laminated fibre-reinforced composites are widely used for various structural components. From impact of a rather small body, the laminates often suffer such damages as delamination and transverse cracking, resulting in a considerable decrease in their stiffness and residual strength. What is worse in practical situations, these damages are usually invisible from the side of impacted surface.

Sixty-eight patients with myasthenia gravis underwent thymic surgery in our department. Among of 68 cases, twenty patients with thymoma were followed and their prognosis were investigated. Sixteen cases received a extended thymectomy with thymomectomy, six cases received local irradiation, and 16 cases received a chemotherapy. Among of 16 cases, 13 cases received corticosteroid only, and 3 cases received CHOP (CPA+ADM+VCR+PSL). Survival rates for thymoma of 20 cases were 94.7%, 88.9%, 78.6%, and 54.5% at 1, 3, 5 and 7 years, respectively. Survival rates for thymoma at 5 years were 83.3%, 50.0%, 100%, and 100% in stage I (complete encapsulation of 8), II (invasion into pericapsular fatty tissue of 7), III (invasion into surrounding organ of 3), and IV a (pleural dissemination of 2), respectively. Survival rate for extended thymectomy with thymomectomy of 16 cases was 81.8% at 5 years. Among of 18 total resection cases of thymoma, a recurrence occurred (5.6%). Causes of 6 death after surgery were crises of myasthenia gravis (3), other diseases (2), and recurrence of thymoma (1).

In this report, the distribution of thymic tissue in the mediastinal adipose tissue was examined histologically in 54 patients with myasthenia gravis underwent extended thymectomy. In fourty-seven of 54 patients, the mediastinal adipose tissues were removed from 6 different parts adjacent to the thymus, i.e., right upper, right middle, right lower, left upper, left middle, and left lower, respectively. Upper area means of around the upper pole of thymus, middle area means of around hilum and lower area means of around from lower pole of thymus to diaphragma. In the mediastinal adipose tissue, thymic tissue was found outside the thymus lobes in 41 (75.9%) of 54 patients. The each prevalence (percent of occurrence) of 6 areas were as follows: 15.0% in the right upper area, 21.4% in the right middle area, 19.0% in the right lower area, 17.5% in the left upper area, 66.7% in the left middle area and 33.3% in the left lower area. There was significant differences in the prevalence of the left middle area according to the other 5 areas (p0.01). There were no significant differences in the prevalences among sex, Osserman type, duration of the disease, pre-operative treatment and histological findings or removal thymus. There were significant differences in the prevalence of all according to the proportion of thymic tissue in the thymus (0.01P0.05). In conclusion, it is suggested that for the removal of all thymic tissue, the sufficient procedure required utmost care especially to the left middle area around thymus.(ABSTRACT TRUNCATED AT 250 WORDS)

During a sixteen-year period, 51 patients with myasthenia gravis underwent trans-sternal thymectomy including extended resection of the adipose tissue around thymus. Using the criteria of risk factors described by Leventhal and Kimura, a predictive score was assessed for our 51 patients. Leventhal's scoring system achieved an accuracy of 54.3%, a sensitivity of 20.0% and a specificity of 63.9%. And, Kimura's scoring system achieved an accuracy of 75.0%, a sensitivity of 81.8% and a specificity of 73.0%. From this study it was concluded that Kimura's scoring system is statistically more adaptive for Japanese than Leventhal's scoring system, and the Leventhal's accuracy may have increased by adding "bulbar symptoms" and "preoperative crisis" as other risk factors and by decreasing "points" for "duration of myasthenia" and "pyridoxamine dosage", and the "Kimura's " accuracy may have increased by decreasing "7 points" for preoperative crisis. Consequently, patients who received postoperative ventilation were compared with the group who did not, with respect to the 19 factors. Evidence is that Osserman's type, bulbar symptoms, preoperative crisis and preoperative % VC were influenced to require the postoperative ventilation, but sex, age, thymic histology, duration of myasthenia and pyridoxamine dosage were not any influenced to require the postoperative ventilation.

The value of astaxanthin, a carotenoid pigment, in the treatment of oxidative injury is assessed. Astaxanthin protects the mitochondria of vitamin E-deficient rats from damage by Fe2(+)-catalyzed lipid peroxidation both in vivo and in vitro. The inhibitory effect of astaxanthin on mitochondrial lipid peroxidation is stronger than that of alpha-tocopherol. Thin layer chromatographic analysis shows that the change in phospholipid components of erythrocytes from vitamin E-deficient rats induced by Fe2+ and Fe3(+)-xanthine/xanthine oxidase system was significantly suppressed by astaxanthin. Carrageenan-induced inflammation of the paw is also significantly inhibited by administration of astaxanthin. These data indicate that astaxanthin functions as a potent antioxidant both in vivo and in vitro.

In order to examine the long-term effects of sternal splitting extended thymectomy in myasthenia gravis 42 patients were evaluated on an annual basis, beginning 12 months after surgery. The effects of surgery on the patients' myasthenic symptoms were as follows: 21.4% of the patients achieved complete remission, 61.9% showed improvement; in total 83.3% had palliation. There were no significant correlation among age, sex, Osserman type, pre-operative treatment and histological findings. Patients with long duration of the disease showed a statistically lower percentage of remission; the patients with complication after operation showed a lower percentage of palliation. The annual transition of the remission rate and the palliation rate were as follows: 11.8% of patients were in remission at 12 months after surgery; 16.1% at 24 months; and 17.4% at 36 months. Moreover 91.2% of the patients were palliated at 12 months after surgery; 90.3% at 24 months; 87.0% at 36 months; and 83.3% at 48 months. There was no significant difference in annual transition rates by age, Osserman type, pre-operative treatment and histology by scattering matric analysis. There was significant differences in annual transition rates according to dyspnea, duration of the disease, sex and post-operative complication.

Y-bar synthetic quartz which is grown on Y-bar seed, has four growth-regions usually called +X, -X, Z and S-regions. The behaviors of each growth region depend on the structure and the distribution of the defects in their existing growth regions.This paper describes the observation results of the characteristic defects in each growth-region and their effects on the vibrational characteristics as a quartz resonator.Dominant defects are classified into following three types; point defects, extended point defects and line defects, such as impurities, inclusions and dislocations. Aluminium, lithium, sodium and hydrogen are dominant impurities found in synthetic quartz. Substitutional aluminium with a monovalent alkali ion is detected by electron spin resonance after γ-ray irradiation, while hydrogen is detected as OH-bond by infrared absorption. Inclusions observed under an optical microscope are believed to be aggregations of small crystals such as acmite (NaFeSi2O6) or more complex alkali iron silicate. Lin...

A continuum theory of finite deformations of an area-preserving material is proposed. The material is assumed to deform preserving both volume and the area on the surfaces defined by unit normal vector field in the material; that is, the material has the internal constraints of incompressibility and “inexpansibility”. After a brief discussion of plane deformations, basic equations for axisymmetric deformations of rotationally symmetric bodies are derived; deformation gradients are explicitly expressed, and compatibility conditions and equilibrium equations are obtained. To illustrate the calculation of deformation and stress, a simple problem of forming a spherical cap from a circular disc is solved.

The linearized theory of viscous-fluid-saturated poro-elastic material proposed by Crochet and Naghdi is summarized and applied to the problem of steady fluid flow through a “twisted pore” elastic cylinder. The cylinder is encased in and bonded to an impermeable rigid tube. Deformations and stresses of the cylinder due to the flow are considered. The results of the mathematical analysis and some numerical computations cast light on the “twisted pore” effect.

The infiltration of a fluid into a dry poro-elastic body, of infinite extent, from its cylindrical or spherical cavity and the resulting mechanical behaviors are investigated. Since the problem is a moving boundary problem, and therefore, an essentially nonlinear one, the finite-difference scheme with the aid of the boundary fixing method is applied to obtain the solution. The results thus obtained for sandstone are compared with those for a porous rigid body as well as with those in a situation where a fluid pervades the whole body from the outset. These comparisons show that the extent of the infiltration front into the body is adequately predicted by the rigid skeleton model and that the actual stress distribution is remarkably different from that which exists if fluid pervades the whole body from the outset.

A study is made of the radial propagation of axial shear waves in an incompressible elastic solid under finite radial deformation. Basic equations are derived on the basis of Biot’s mechanics of incremental deformations, and analysis is made by the method of characteristics. Numerical examples are given by specializing the initial deformation to two cases: (a) an infinite solid with a cylindrical bore is inflated by all-around tension, and (b) a cuboid is rounded into a ring and its ends are bonded to each other. The influence of the inhomogeneities of such deformations upon the laws of shear wave propagation is presented in the form of curves.

Following the derivation of the relations of incremental stresses and strains for an idealized fiber-reinforced isotropic elastic material, the instability problem stated in the title is analyzed on the basis of Biot’s mechanics of incremental deformations. The analysis indicates that the slab reinforced by fibers along the direction of its thickness under axial loads becomes unstable in a manner different from the case of an unreinforced slab. In the course of the analysis the material was specified as the so-called Blatz-Ko rubber, solid and foam. It was found that the slab of solid rubber buckled only under compression, while that of foam rubber became unstable under tension as well as under compression. There exist two types of buckling for foam rubber under tension: a shear buckling and an internal buckling. However, the latter does not manifest itself physically since the former always occurs first.

The amplitude and frequency dependences of sharp peaks in internal friction versus temperature curves in silver chloride crystals are studied. For a peak at higher temperatures, the amplitude and frequency dependences are abnormal; the peak temperature is higher for larger amplitudes and for lower frequencies. This phenomenon is explained by the fine structure of each pinning point in the dense row of large colloids. This idea is incorporated in the previous model of simultaneous liberation of dense pinning points on dislocations resulting in sharp peaks. For a peak at lower temperatures, no amplitude and frequency dependences are observed unless the frequency is very high, this phenomenon is also explained by the same theory.

After obtaining the relations between incremental stresses and incremental strains, we analyzed the instability problem stated in the title on the basis of Biot’s mechanics of incremental deformations. The slab, made of a hypothetical transversely isotropic compressible elastic material, is assumed to be stronger in its transverse direction than in its axial direction. The analysis shows that, no matter what the anisotropy strength of the slab is or its thickness is, it can become unstable under tension as well as under compression. The critical load is higher for the stronger anisotropy in the compressive case, while it is lower for the stronger anisotropy in the tensile case. In other words, the reinforcement in the “wrong” direction weakens the slab under tension with respect to its stability. Furthermore, the weakly anisotropic slab can become unstable only after the axial resultant force reaches its maximum, while the strongly anisotropic slab can lose its stability before the force reaches its maximum.

An attempt was made to estimate the compressive strength of fiber-reinforced materials in terms of the fiber-volume-fraction by the theory of continua with internal kinematical constraints of inextensibility. The dependence of the compressive strength on the volume-fraction as well as on the fiber-buckling wave-length is presented by curves.

Radiation‐induced conduction in polyethylene‐terephthalate under high electric field (1×106 to 1.6×108 V/m) has been studied. At field strengths below 1×108 V/m, the induced current reaches its initial steady‐state value (primary component) soon after irradiation is initiated, then monotonically decreases with time thereafter. This decrease of current is due to a ’’polarization’’ effect. Above 1×108 V/m, the induced current decreases for a while then increases again to reach the equilibrium value (secondary component). This secondary component is due to the electron injection, enhanced by the fixed positive space‐charge accumulation near the cathode. The radiation‐induced conductivity of the primary component increases with electric field strength between 1×106 and 1×108 V/m and then shows a saturation tendency above 1×108 V/m. This may be due to geminate recombination in the carrier generation process. The primary component in the 50‐μm‐thick specimen is deduced to be dominated by a deep‐trapping‐limited process. The primary component of the induced current in a 6‐μm‐thick specimen is demonstrated to attain saturation above 1.2×108 V/m.

Using the theory of ideal fiber-reinforced composite materials, an equilibrium solution was obtained for the finite three-point bending of a beam which has a central step on its bottom surface. The beam is axially reinforced by fibers and simply supported by fixed roller fulcrums. It was found that the exact solution reached by the rule of trial and error is statically and kinematically admissible only for a linear elastic (or quasielastic) shear response. The equilibrium condition of the portion of the beam corresponding to the step edge is reduced to a Fredholm type integral equation of the second kind with respect to the curvature radius of the uppermost fiber.

An equilibrium solution was obtained for the finite shear-band buckling of a fiberreinforced slab under axial compression, using the idealized theory of continua with the kinematical constraints of incompressibility and inextensibility. It was found that the critical buckling load wasGH, the infinitesimal shear modulusG times the thicknessH of the slab. The solution, involving discontinuities in deformation gradients at the shear-band edges, was proven to conform of the dissipation inequality (under a certain restriction on the material response), which implies the energetical admissibility of the solution obtained. Furthermore, compression tests of beechwood blocks proved that their buckling patterns of shear band type were similar to the theoretical ones. The experimental and theoretical load-shear curves showed good agreement.

The transient response of a fluid-saturated poroelastic layer resting on a very porous rigid foundation and subjected to a sudden fluid pressure rise on its upper surface is analyzed on the basis of Biot’s theory of poroelasticity. Compaction of the layer and fluid outflux from its bottom surface are calculated for five typical poroelastic materials: alundum and Ohio sandstone saturated with water, compact bone, and Albany felt and polyurethane foam filled with silicone fluid. For each of these materials, the numerical results are compared with those estimated by the “incompressible model” as well as the “rigid skeleton model” in order to examine the validity of these models.

Conventional HDTV cameras lack sensitivity, so the iris must be opened two to three stops wider compared with practical cameras working within existing TV standards. This narrows the depth of focus, sacrificing picture quality. A more sensitive HDTV camera tube that combines a new high-gain avalanche rushing amorphous photoconductor {HARP) target and 2/3-in. high-performance magnetic-focus electrostatic-deflection (MS) electron optics is proposed. The combination results in a super-sensitive camera tube (10 times as sensitive as the Saticon) with an amplitude response of 36% at 800 TV lines (aspect ratio 4:3). This was achieved with no sacrifice in picture quality and no deterioration in resolution, lag, spectral response, or noise characteristics. After-image is negligible.

A study is made of the radial propagation of rotary shear waves in an incompressible elastic solid under finite radial deformations. Basic equations are derived on the basis of Biot's mechanics of incremental deformations, and analysis is made by specializing the initial deformations to two cases: (a) an infinite solid with a cylindrical bore is inflated by all-around tension, and (b) a cuboid is rounded into a ring and its ends are bonded to each other. The influence of the inhomogeneities of such deformations upon the laws of shear wave propagation is presented in the form of curves.

This paper concerns shear-band bifurcations from the homogeneous finite plane deformation of an isotropic compressible hyperelastic solid. The governing equations for the incremental plane deformation superposed on the initial finite deformation are derived and then the equilibrium equations in terms of incremental displacements are classified into the elliptic type, parabolic type, etc. From this classification follows a restriction which should be placed on the strain-energy function in order that the equilibrium equations may be either elliptic or parabolic for all principal stretches. For the hyperelastic solid complying with this restriction, the condition for the shear-band bifurcation is obtained. Finally, the incremental displacement field of an infinite series of shear bands in a slab sandwiched between slippery rigid layers is established.

For an axisymmetric problem under incremental deformation theory for neo-Hookean solid, a basic equation to be satisfied by a displacement function is obtained and the components of incremental displacement, strain and stress are expressed by the displacement function. Using the basic equation and expressions, the distribution of incremental stress in the neighbourhood of a circular crack with internal pressure in an infinite body under an initial finite deformation owing to all-around compression is investigated, and the influence of initial stress upon the distribution of incremental stress is presented in the form of curves. Im Rahmen einer Theorie infinitesimaler zusatzlicher Deformationen (incremental deformation) neo-Hooke-scher Korper wird fur ein achsensymmetrisches Problem eine Grundgleichung hergeleitet, der die Verschiebungsfunktion zu genugen hat, und es werden Spannung und Verformung durch die Verschiebungsfunktion ausgedruckt. Auf dieser Grundlage wird in einem unendlichen Korper, der unter der Wirkung eines allseitigen Druckes eine endliche Verformung erlitten hat, die Verteilung des Spannungszuwachses in der Nachbarschaft eines kreisformigen Risses mit innerer Druckbeanspruchung untersucht, und es wird der Einflus der Anfangsspannung auf die Verteilung des Spannungszuwachses in Diagrammen dargestellt.

The present paper deals with the propagation of unattenuated axisymmetric waves of small amplitude guided by a cylindrical bore through a neo-Hookean solid of infinite extent, which is finitely deformed by an all-around tension at infinity. The basic equations for the axisymmetric case are derived on the basis of Biot’s mechanics of incremental deformations, and applied to the problem by using Galerkin’s method. The influence of nonhomogeneous initial stresses upon the phase velocity of shear waves is presented in the form of curves.

The incidence of serum hepatitis after the transfusion of blood cells was clinically studied. The results obtained were as follows:1) 28 operative cases were divided in two groups, so that one pare of cases was similar in the operative risk and the operative procedure. On the other hand 400cc whole blood of a donor was divided in two bottles. The one was transfused as the whole blood to a case in the first series and the another transfused as the sedimented blood cells to a cases of the second series. The result showed that in the 1/3-1/4 of the cases of the whole blood transfusion series an elevation of SGOT and SGPT was obserbed usually at the 3rd or 6th month in the posttransfusion periode, in the cases a latent hepatitis was suspected. The changes in the cases of the sedimented blood cells series were rare and slighter.2) The incidence of posttransfusion jaundice in our clinic (operative cases from July 1963 to February 1964) was as TABLE.These results show that the sedimented blood cells transfusion is benefisial to prevention of serum hepatits than the whole blood transfusion.3) Our method of the preparation and the preservation of blood cells was discussed. As the centrifugation of whole blood and the preservation of blood cells as a “Suspended blood cells” shorten the preservable periode, we use favorably the method “Natural sedimentation of blood cells”, preservation of cells alone, not in a form of suspention and transfusion mixed with a suitable medium (plasma expander etc.) on bed side.

The problem of the deflection and moment distribution resulting from a uniform temperature difference between upper and lower faces of a circular plate containing a ring of equally spaced circular holes is solved within the framework of the Poisson-Kirchhoff space theory of plates. A general boundary condition is applied at the outer rim of the plate to make the solution valid for a range of conditions from the simply supported case to the clamped case. The edge of the perforations are free. Numerical results in the form of curves are given for typical cases.

Radiation‐induced conduction in polyethylene‐terephthalate (PET) has been measured under high electric field (1.0×106 to 1.6×108 V/m). In a 6‐μm‐thick PET film, saturation of the radiation‐induced current occurs at field strengths above 1.2×108 V/m. This has been demonstrated by the thickness and dose rate dependence of the induced current. Radiation‐induced conductivity increases monotonically with field strength, then shows a saturation tendency. This may be explained by geminate recombination. Above 1×108 V/m, slowly increasing radiation‐induced current appears. This may be caused by electron injection from the cathode, enhanced by the accumulation of the hetero space charges near it.

The γ‐ray‐induced conduction of polystyrene and poly‐monochloro‐para‐xylylene at high electric fields exhibits a slowly increasing component whose magnitude depends upon the nature of the metal used for the anode, but not that used for the cathode. This phenomenon is interpreted as hole‐injection current, enhanced by the accumulation of negative space charges during the irradiation.

In order to develop extremely compact camera tubes which feature low power consumption comparable to solid-state imagers, we have developed an all-electrostatic camera tube based on electron optics characterized by a single-and-positive lens system composed of disk and cylinder electrodes. The new system was found to be very useful in producing compact high-performance camera tubes, due to its simple configuration and lack of negative lens component.