Transformation studies and mechanical properties of melt-quenched amorphous titanium-silicon alloys

The formation, stability and decomposition characteristics of the amorphous phase in binary titanium-silicon alloys rapidly quenched from the molten state have been investigated. Electron microscopy and diffraction coupled with X-ray diffraction techniques suggested that the amorphous phase could be obtained in alloys containing 15 to 20 at% silicon. The transformation of the amorphous phase to the equilibrium phases took place in two stages. A metastable b c c titanium solid solution, containing silicon in excess of the equilibrium value, formed initially, followed by the precipitation of the Ti₅Si₃ intermetallic compound. Microstructural features at various stages of decomposition have been described and interpreted in terms of the constitution of the alloys. Mechanical properties of the amorphous alloys have also been investigated.     

Expression of Pax5 gene in human haematopoietic cells and tissues: comparison with immunodeficient donors

We have studied the effects of moguisteine, a new non-narcotic, peripherally acting antitussive compound, on tracheobronchial rapidly adapting irritant receptors (RARs). Experiments were carried out on dogs anaesthetized with a mixture of urethane and alpha-chloralose, paralysed with gallamine, vagotomized and artificially ventilated. Single unit action potentials identified as originating from tracheobronchial RARs were recorded from the peripheral cut end of the right vagus nerve. The activity of these receptors was recorded together with oesophageal pressure and arterial blood pressure. Fourteen RARs were challenged with moguisteine (200 microg x kg[-1] i.v.) in 0.4% dimethylsulphoxide (DMSO) or 0.4% DMSO alone (vehicle). Receptor activity was recorded before (control) and at 2, 5, 10, 15, 20, 30 and 45 min after administration of the challenging compounds. When the results at intervals of 2, 5, 10, 15 and 20 min were averaged for each dog, it was found that moguisteine decreased the mean activity of the 14 receptors to 75% of the control value (p<0.05); the greatest inhibition occurred 10-20 min after moguisteine administration. DMSO did not significantly affect the activity of these endings. Oesophageal pressure, arterial blood pressure and cardiac frequency were not altered during the experimental procedures. The overall results indicate the presence of an inhibitory effect of moguisteine on rapidly adapting irritant receptors that could account for the antitussigenic effect of this compound.     

The effect of aluminium on mechanical properties and thermal stability of (Fe,Co, Ni)-Al-B ternary amorphous alloys

Amorphous phase formation has been found in a wide range of Fe-Al-B, Co-Al-B and Ni-Al-B ternary systems by a melt-quenching technique. The aluminium content of these amorphous alloys is in the range 0 to 60 at % for Fe- and Co-Al-B systems and 0 to 26 at % for the Ni-Al-B system, but the formation of ductile amorphous phase is limited to less than 20 at % Al. Crystallization temperature and Vickers hardness increase with increasing aluminium and boron content and maximum values are attained at 887 K and 880 diamond pyramid number (DPN). Their fracture strengths are about 2140 to 2680 MPa. The effectiveness of aluminium on the increase in crystallization temperature and hardness is greater in the case of other metal elements such as chromium, manganese, iron, cobalt and nickel, but is less than the metalloid elements such as silicon and boron. This could be reasonably explained by the assumption that aluminium may also possess a weak metalloid character.     

Emission current regulator for ion cyclotron resonance spectrometers using an optical coupler. II

An emission current control circuit for ion cyclotron resonance spectrometers has been constructed which maintains a constant beam current in the range 10(-11)-10(-6) A with pulsed grid modulation. It regulates emission currents by automatically adjusting grid bias voltages with reference to a feedback signal. A solid state optical coupler is employed to transmit the feedback signal to a grid biasing circuit having a floating common voltage to accelerate electrons. Control to better than 0.1%/h is possible at any emission current between 10(-10) and 10(-6) A, and control to 0.3%/h at 10(-11) A.     

Computer-aided protective system hazard analysis

Based on a fault tree for a plant and on two fault trees for its protective system, the computer code, PROTECT, produces time profiles of expected numbers of normal trips, spurious trips, and destructive hazards. Input parameters to PROTECT are (1) minimal cut sets of the fault trees; (2) mean time to failures of basic components; (3) failure characteristics of operators; (4) scheduled maintenance intervals for plant and protective system; and (5) repair times from normal and spurious trips. Using the code, we can design the protective systems and maintenance policies, keeping both destructive hazards and spurious trips below acceptable levels.     

Langmuir-temkin-pyzhev rate models for ammonia decomposition reaction

Existing rate data of ammonia decomposition were correlated using the Langmuir-Temkin-Pyzhev models and the applicability of those models was examined. Conventional statistical tests indicated that the Langmuir-Temkin-Pyzhev model was adequate, but the physico-chemical examination of parameter estimates showed that the model was not feasible. The Temkin-Pyzhev model was also employed to describe the decomposition data and discussed.     

A Source for Multiply-Charged Ions and Acceleration of C, N and O Ions by IPCR Cyclotron

The design and performance of the ion source which is now used in the IPCR variable energy cyclotron are described. The source is of the electron-bombarded hot cathode type having two cylindrical cathodes of tungsten and a water-cooled copper anode containing a replaceable molybdenum slit plate. The arc discharge is established continuously but not pulsed. The source is usually operated very stably under an arc power of 1.5 to 3kW with a gas flow rate of 1 to 2 cc/min. The lifetime of the source is mainly limited by the erosion of the upper tungsten cathode at about 24 hours. At present, C4+, N4+, O4+, N5+ and O5+ ions are accelerated up to 48~100, 56~1100, 70~95, 56~125 and 70~125 MeV respectively, and a few micro-amperes of these ions are extracted from the cyclotron. The vacuum obtainable in the accelerating chamber is usually 2 ~ 4 × 10-6 mHg, and the loss of ion beam by the charge exchange effect is comparatively small. Extracted ion beams are used in several experiments for about 1900 hours in a year.     

Separate and/or simultaneous generations of non-linear functions inherent in non-ohmic resistivities

In this paper, it is described that a multiple-function generator can be realized without employing any separate function-generating units and selector-logics. According to this proposal, a uniformly continuous non-linearity o f a non-ohmic resistance is first expressed by a linear combination of several interesting non-linear functions with respect to the same input variable. Then, the desired functions can be obtained by summing up algebraically the linearly independent non-linear currents passing through every non-ohmic resistance with their proper weights. It is noticeable that an adjustment of the weights will permit different non-linear functions separately and/or simultaneously. Details of this system will be furnished with quantitative investigations and experimental results.     

Studies on the TRH test on the patients with Graves' disease during the treatment with antithyroid drug (author's transl)

A study was performed to observe serum TSH response following TRH injection (TRH test) in 79 cases of Graves' disease (male 23, female 56, aged 16-70 years old), before and during treatment by antithyroid drug, in a total of 244 occasions. Treatment was mostly the daily administration of methyl-mercaptoimidazole (MMI), and in one case of propylthiouracil (PTU). TRH test was conducted by i.v. administration of 500 mug synthetic TRH, and subsequent 6 blood drawing until 2 hours. Serum TSH was measured by radioimmunoassay in each serum, and serum T4, T3, RT3U and cholestrol were measured in the serum before TRH injection. In some cases, the results of TRH test were compared with those of T3 131I thyroidal uptake suppression test, using the 131I uptake values at 20 min. and 24 hours. Results were obtained as follows: 1) Some cases showed positive TRH test at the early stage of treatment when the patients were in eumetabolic states, while many patients showed no TSH response in spite of their long maintenance at eumetabolic states. 2) When both serum T4 and T3 were high, all cases showed no response of TSH. When serum T4 alone was high, all cases except one case showed no response;whereas when serum T3 alone was high, 5 cases showed normal response. When both serum T4 and T3 were below normal, 2 cases showed no response. When serum T4 was low, all cases showed response; whereas when serum T3 alone was low, 6 cases showed no response. Thus, there was no positive correlation between TSH reactivity and serum concentrations of thyroid hormones. 3) No correlation was observed between TSH reactivity and the period after the onset of hyperthyroidism. 4) In 57 cases of Graves' disease, who were under treatment and in eumetabolic states, a comparison was made between TSH reactivity and the results of T3 suppression test. In T3 suppressed group, 19 showed response, and 3 showed no response; whereas in T3 non-suppressed group, 18 showed response and 17 showed no response. In the group of T3 non-suppression as well as in the group of T3 non-suppression plus TRH no response, there was a significant elevation of serum T3 compared with the control group. 5) TRH test does not appear to be an appropriate test as a predictive method to know the permanent remission of Graves' disease.