Focus Issue on Male Infertility

Male infertility problems can occur when sperms are limited in number or function. In this paper, we describe the clinical evaluation of male infertility. A detailed history, physical examination, and basic semen analysis are required. In addition, ultrasound, karyotyping, and hormonal studies are needed to determine specific causes of infertility. In addition, the World Health Organization (WHO, 2009) has developed a manual to provide guidance in performing a comprehensive semen analysis. Among the possible reasons for male infertility, nonobstructive azoospermia is the least treatable, because few or no mature sperm may be produced. In many cases, men with nonobstructive azoospermia typically have small-volume testes and elevated FSH. Although treatment may not completely restore the quality of semen from men with subnormal fertility, in some cases a successful pregnancy can still be achieved through assisted reproductive technology

Sub-Boundaries in Aluminium Single Crystals

Single crystals of aluminium 99.97 per cent pure were made by the Bridgman method under various conditions, and the Laue spots were precisely studied with specimens which, on being etched, showed no macroscopic inhomogeneity. It was found that some spots were frequently splitted, whereas those diffracted from certain lattice planes were of the usual form, and that these special planes were {113} or planes lying close to them. From these results it was concluded that the splitting of Laue spots was due to a small angle interface of a bicrystal grown along the maximum temperature gradient, and that this boundary could be formed by the relative rotation of the crystals around [112] about one degree. Such boundary was explained by the mechanism of polygon wall in the the theory of dislocation

Relation between Deformation and Integrated Intensity of X-Ray in Aluminium Single Crystals

The relation between the deformation and the integrated intensity of X-ray was investigated with aluminium single crystals, and it was found that with increasing slip deformation the reflected intensity first increased rapidly, and then gradually reached a saturation at about 2 per cent elongation, irrespective of the tensile direction relative to the crystal orientation. The preferential deformation at the surface layer was deduced from the change in integrated intensity of X-ray reflected from specimen of various thicknesses prestrained by a few per cent. It was seen that the region giving a maximum reflected intensity was not the outermost surface of crystal but the inner layer about 10μ from the surface, and that with increasing deformation this region extended into the crystal. Further, the orientation dependence of the reflecting power in a plastically bent state was examined on (111) reflection by a Geiger counter diffractometer, and it was seen that the change in the reflected intensity related to the crystallographical relation of stress direction

X-Ray Study of the Effect of Solute Atoms on Deformation Stacking Faults in Face-Centred Cubic Solid Solutions

X-ray study of copper-nickel alloys pulverized by a ball mill and a stamp mill was carried out. Line peak shifts due to deformation stacking faults were observed by a Geiger counter spectrometer, and the stacking fault probability was calculated. The density of dislocation was estimated from the line broadening. From these experiments it was seen that the peak shift (or stacking fault probability) and the density of dislocation increased with the increase in solute content, reaching a maximum at 50～50 composition. The stacking fault energies of copper-nickel alloys were estimated from the equation proposed by Cottrell as a function of the solute content, which showed a downward concave curve ; for example, the stacking fault energies of copper, copper 30 per cent-nickel and nickel were 30, 50 and 100 erg/cm^2 respectively. In order to investigate on the segregation of solute atoms around the boundaries of stacking faults, small angle scattering experiments were carried out with copper-aluminium alloys severely cold-rolled at room temperature. And some observations on line profiles of the diffraction patterns were also made with powder samples of copper-aluminium, copper-nickel and copper-zinc alloys in order to see the effect of segregation of solute atoms on the diffractions. After all, it was concluded that in face-centred cubic solid solutions the solute atoms concentrated around faulted layers even at room temperature

Scratch Hardness. II : X-Ray Investigation of Structural Change

The structural change due to scratching or indenting aluminium and silver was studied by X-ray analysis, and it was seen that it was a reasonable interpretation that the scratch hardness of a metal is related to the annealed state, which is contrary to Tammann\u27s view

X-Ray Study of Cold-Worked Metal Single Crystals

The change in the reflected intensity of X-ray due to the deformation of metal single crystals of aluminium and zinc was examined with microphotometer by using Cu-K_α radiation. In aluminium single crystals, a large change in the relative intensity of {111}-reflections was observed with an increase of the deformation, and almost saturated at a few per cent elongation. The increasing rate of the relative intensity reflected from the active slip plane was larger than that from the latent slip planes. Similar results were obtained with zinc single crystals. The increase in the integrated intensity was explained as caused by the reduction in the extinction due to the fragmentation of crystallite blocks, from which it was concluded that the distortion after slip deformation was larger in the active slip plane than in the latent slip planes. In other words, the strain-hardening is larger in the active slip plane than in the latent slip planes. Further, the recovery of the relative intensities was examined, and it was seen that in aluminium crystal it was incomplete even after long-time annealing at high temperature, whereas in zinc crystal it was almost perfect at short-time annealing

Study of Cold-Working by Microfocussing X-Ray. I : Fine Structure of Laue Spot

By giving cold-working and annealing successively to aluminium single crystals made from the melt, the changes in Laue spots were observed by the ordinary and microfocussing X-rays. It was found that with the repetition of working and annealing the fine structure of the Laue spots from the operative slip plane grew complicated, depending on the temperature of annealing. In the case of low temperature annealing, the lamellar structure of the spot remained stable, while in the case of high temperature annealing it changed into an irregular, complicated structure incapable of being resolved with the present apparatus

Defect Structure and Density Decrease in Neutron-Irradiated Quartz

Lattice defects in quartz induced by fast neutron irradiation were studied by combined methods of x-ray diffraction and transmission electron microscopy. The developed defect structure is characterized by clusters of interstitials enriched in ruptured silicon atoms. The size and density of the defect clusters increase with increasing dose until mutual interaction occurs, resulting in the formation of a stable, hexagonal-like structure resistant to prolonged annealing at 500℃. In thin crystals the size and volume fraction of the defect clusters are dependent on crystal orientation, being related to the open screw channels of the quartz structure. A relationship was established between the total volume fraction of defect clusters and fractional decrease in density induced by neutron irradiation, accounting satisfactorily for the hydrostatic density measurements reported in the literature