New Evaluation of $$T-T_{2000}$$ from 0.02 K to 1 K by Independent Thermodynamic Methods

This paper reports on the results achieved within the European Metrology Research Programme project “Implementing the new kelvin—InK” in the low-temperature range below 1 K. One of the main objectives of the InK project was the determination of new thermodynamic temperature data for comparison with the Provisional Low Temperature Scale 2000 (PLTS-2000), to provide reliable \(T-T_{2000}\) values. To this end, we have investigated three different types of primary thermometers: the current sensing noise thermometer, the primary magnetic field fluctuation thermometer and the Coulomb blockade thermometer. Based on a thorough investigation of the thermometers, detailed uncertainty budgets were established for the measurement of thermodynamic temperatures. Direct comparison measurements between all thermometers demonstrate the agreement of temperature measurements within less than 1 %. Our new \(T-T_{2000}\) data confirm the correctness of the PLTS-2000 in the temperature range from 20 mK up to about 700 mK with relative combined standard uncertainties better than 0.62 %.     

The effect of frictional force amplitude on the degradation of SiC abrasive papers

The degradation of 600 and 100 grade SiC abrasive papers by unidirectional and reciprocating frictional contact was studied. The mechanism of deterioration is basically different for each grit size. Detachment of grits from the resin base and the volume of metal removed depend on the type of friction. The rate of detachment of blunt grits is higher for reciprocating frictional contact than for unidirectional frictional contact. This can be explained in terms of the fatigue strength of the cementing resin base under completely reversed stress and pulsating stress caused by the rubbing action.     

Cladinose analogues of sixteen-membered macrolide antibiotics. VI. Synthesis of metabolically programmed, highly potent analogues of sixteen-membered macrolide antibiotics

Five novel 3-hydroxyl derivatives of sixteen-membered macrolide possessing 4-O-acyl-alpha-L-cladinose as a neutral sugar moiety were synthesized by using a combination of structurally stable silyl acetal protection and selective hydrogenolysis of a 3"-methylthiomethyl ether to a 3"-OMe group. Several derivatives having n-butyryl, i-butyryl and n-valeryl substituent at the 4"-OH group exhibited significant antibacterial activity in vitro. One of them, 4"-O-n-butyryl-3"-O-methylleucomycin V, showed improved therapeutic effect in mice.     

Retinal pigment epithelial cell-based gene therapy against hemoglobin toxicity

The aim of this pilot study in 54 patients was to improve the visualization of the anatomy and postoperative changes in the pelvic topography after bilateral ureteroileal urethrostomy, using surface rendering of electron beam CT (EBCT) data for the 3D display. Fifty-four patients (39 men and 15 women) were scanned with an EBCT unit between 3 and 110 months after performing orthotopic ureteroileal urethrostomy ("Hemi-Kock") or ureteroileal rectosigmoidostomy. Various parameters and spatial viewing points were used in the 3D reconstruction, which was performed interactively on external workstations with commercially available software. The anti-reflux nipple was visualized as a distinct structure in all patients. In 8 patients with an interval of more than 12 months between surgery and CT, the pouch had developed an ovoid shape almost indistinguishable from the original bladder. The segmented data sets were partly animated to display the anatomy as virtual endoscopy. Three-dimensional depiction and virtual endoscopy of the neobladder using EBCT are a new way of imaging the postoperative anatomy. Its clinical efficacy in the diagnosis of inconclusive postoperative morbidity, especially voiding problems, and planning of necessary therapy have to be the subject of further evaluation.     

TOF-SIMS analysis of perfluoropolyether lubricant smear transferred from disk surface following laser heating

Microsystem Technologies - The structural and molecular weight changes of perfluoropolyether lubricant picked up following laser heating in heat-assisted magnetic recording (HAMR) were analyzed...     

Highly efficient damage-free correction of thickness distribution of quartz crystal wafers by atmospheric pressure plasma etching - [letters]

A new finishing method was developed to correct the thickness distribution of a quartz crystal wafer by the numerically controlled scanning of a localized atmospheric pressure plasma. The thickness uniformity level of a commercially available AT-cut quartz crystal wafer was improved to less than 50 nm without any subsurface damage by applying one correction process. Furthermore, applying a pulse-modulated plasma markedly decreased the correction time of the thickness distribution without breaking the quartz crystal wafer by thermal stress.     

Effect of humidity and temperature on polymer electrolyte membrane (Nafion 117) studied by positron annihilation spectroscopy

Polymer electrolyte fuel cells (PEMFC) have emerged as portable power source for future transportation and home based systems. Over the past years perfluorosulfonated cation exchange membranes have been used as solid polymer electrolyte in fuel cells, however, humidity control and water management have remained major issues in the area of stack development. Local drying that results in the changes in the local conductivity behavior and physical failure of the membrane is one of the key issues to be addressed in detail. It is therefore necessary to estimate these changes precisely to evaluate the membrane behavior during the fuel cell operation. Positron annihilation spectroscopy offers a very sensitive probe to the determination of polymer free-volume as well as electronic state of the polymer. In the present study we studied Nafion 117 with varying temperature and humidity using positron annihilation spectroscopy. The ortho-positronium lifetime (o-Ps, i.e., τ₃) which gives the size of the free-volume holes inside the polymer was determined. It was found that the o-Ps lifetime increases for relative humidity between 40% and 60% and thereafter it decreases in the temperature range of 62-95 °C. When the inversion point at which the o-Ps lifetime is the maximum was plotted with actual vapor pressure, it was observed that it has a logarithmic behavior with the ordinate intercept of 1 ns. This indicates that at higher temperature the membrane has larger free-volume holes; and also at higher temperature a larger vapor pressure is essential to saturate the membrane. Above this point the clusters expand and the free-volume hole size decreases. This also indicates the optimum vapor in the cell to be maintained during the fuel cell operation. The studies also indicated that there is a correlation between o-Ps lifetime and the hydrogen crossover current density under the similar temperature and humidity condition.     

Analysis of cesium isotope compositions in environmental samples by thermal ionization mass spectrometry – 1. A preliminary study for source analysis of radioactive contamination in Fukushima prefecture

Cesium was recovered from plant samples obtained from Fukushima prefecture. The isotopic ratios of ¹³⁴Cs/¹³⁷Cs and ¹³⁵Cs/¹³⁷Cs were analyzed by thermal ionization mass spectrometry with a single filament method using a TaO activator. Samples containing 5 Bq of ¹³⁷Cs were analyzed with typical analytical errors of approximately 0.5% for ¹³⁴Cs/¹³⁷Cs and approximately 0.1% for ¹³⁵Cs/¹³⁷Cs. Measurements of both ratios showed profiles that were characteristic of the measurements of among other environmental samples reported in the literature. The results showed the isotopic ratios of ¹³⁴Cs/¹³⁷Cs and ¹³⁵Cs/¹³⁷Cs were applicable for the source analysis of radioactive Cs in Fukushima prefecture.     

Current density redistribution from no current crowding to current crowding in Pb-free solder joints with an extremely thick Cu layer

In order to remove the effect of current crowding on electromigration, thick Cu under-bump metallization has been widely adopted in the electronics industry. Three-dimensional (3-D) integrated circuits, using through Si via Cu column interconnects, is being developed, and it seems that current crowding may not be a reliability issue. However, statistical experiments and 3-D finite element simulation indicate that there is a transition from no current crowding to current crowding, caused by void growth at the cathode. An analysis of the electromigration-induced failure mechanism in solder joints having a very thick Cu layer is presented. It is a unique failure mechanism, different from that in flip chip technology. Moreover, the study of marker displacement shows two different stages of drift velocity, which clearly demonstrates the back-stress effect and the development of compressive stress.     

Characterization of fertilization-blocking monoclonal antibody 1G12 with human sperm-immobilizing activity

A mouse hybridoma (1G12) producing sperm-immobilizing MoAb to human sperm was established and characterized in order to study the antigens relevant to sperm immobilization by antibodies. MoAb 1G12 had strong sperm-immobilizing and agglutinating activities and also showed a fertilization-blocking activity on in vitro fertilization tests. The antibody absorption experiments showed that MoAb 1G12 reacted not only to ejaculated sperm but also human seminal plasma, suggesting that the corresponding antigen might be a sperm coating antigen. The MoAb also reacted with peripheral blood lymphocytes. In histochemical studies, the epithelia of corpus epididymis were most strongly stained. Ejaculated sperm were stained with a granular pattern for their entire surface by immunofluorescence. MoAb 1G12 recognized polymorphic glycoproteins of 15-25 kD in the ejaculated sperm extract in Western blot analysis. After deglycosilation of the sperm extract, only a single staining band of under 15 kD was detected by MoAb 1G12. This suggests that the antigen epitope recognized by MoAb 1G12 might be a peptide of the core portion of the glycoprotein. MoAb 1G12 might be a useful tool for studying the mechanism of egg-sperm interaction, and also be applied to identifying the corresponding antigen by using gene technology.