STABILITY TEST OF SRC II DISTILLATES BY ESR

ABSTRACT

The stability of distillates derived from the SRC II coal liquefaction process has been investigated by means of electron spin resonance (e.s.r.). The samples were prepared by storing at room temperature for 8 days in air or in vacuo. The lighter fraction of distillate deteriorated more easily via oxidation than the heavier fraction.     

Tank模型及其在边坡水位预测中的应用

 Tank模型可以模拟非线性的降雨–地下水运移过程,并且能迅速得到解答。基于现有的单列tank模型,提出新的复合水箱模型。由于新模型参数超过20个,应用传统优化算法难以快速找到最优解,一种新的启发式自搜索算法(变维数搜索算法)被引入并改进后用于模型最优解的寻找。变维数搜索算法能够根据搜索进程的变化自动改变搜索维数并且快速找到最优解。27个参数的复合tank模型被应用于日本国道九号线的一个边坡,计算结果表明：变维数搜索算法能够在10 min左右找到合适的最优解;降雨过程复合tank模型计算的地下水位变化和观测值非常接近。最后通过和有限单元法计算结果的比较表明,有限单元法的计算结果受地质渗透特性的影响很大,而复合tank模型不存在这种问题。工程实例计算表明,该方法和监测结果比较一致,但其适应性更强,特别适用于没有进行足够地质结构探查的边坡。它能够快速反映降雨过程中地下水位的运移过程,可以推广使用。     

T1ρ study of pitch softening

Proton rotating frame spin-lattice relaxation time (T_1ρ) measurements have been made in 10 samples of pitch from room temperature to 673 K to obtain information about the mechanisms of pitch softening. The T_1ρ minimum of pitch was found to occur at approximately the same temperature as the softening point. This result suggests that the softening phenomenon of pitch can be detected at the molecular level by T_1ρ measurements. Laboratory frame spin-lattice relaxation time (T₁) measurements were also made on pitches to obtain information about the molecular motion of pitch in the high frequency ranges.     

Fano factor in gaseous argon measured by the proportional scintillation method

It is found that the apparent Fano factor in argon obtained by using 5.90 keV X-rays with the proportional scintillation method depends on the gas pressure and that the true Fano factor can be obtained by extrapolating the linear relation between the apparent Fano factor and the reciprocal of the gas pressure. The Fano factor thus obtained gives good agreement, within experimental errors, with the value recently obtained by using a gridded ionization chamber.     

PWM Inverter Using High-Gain Pulse-Triggered Power Transistors and a New PWM Control Method

Rugged PWM transistor inverters are expected to be put into practical use for providing high reliability under adverse operating conditions. The bipolar power transistors are more common compared with MOSFET's power transistors in balance between power-handling capability and switching speed. High over current capability, low switching loss, high-speed switching, and high-current gain are requisite functions in the PWM inverter employing bipolar power transistors. These functions are of great concern in the power electronics field. A new PWM transistor inverter which can meet these requirements is presented in this paper. For this purpose, a concept of high-gain pulse-triggered power transistor (PTPT) with amorphous saturable current transformer (CT) is introduced.     

Acid hydrolysis behaviour of microbial cellulose II

A mutant strain of Acetobacter xylinum produces cellulose of anomalous band-like form (‘native band’), and this material has been found to be cellulose II, presumably having a folded-chain structure (according to recent work by Kuga et al.). In addition to the previous results of electron diffraction, X-ray analysis showed that this band material was composed of virtually pure cellulose II. We have studied the acid hydrolysis behaviour of this material to obtain additional evidence for the proposed structure. When hydrolysed with 1 N hydrochloric acid at 100°C, the degree of polymerization (DP) of the material decreased rapidly from 322 ( ) to 18.3 ( ). The latter value (levelling-off DP) corresponds to the observed width (10 nm) of strand-like constituents of the band material. The sample dissolved in and regenerated from 8.75% aqueous sodium hydroxide lost its original characteristic morphology and became irregular-shaped agglomerates. The leveling-off DP of this regenerated sample was 55.2 ( ), a typical value for common regenerated celluloses. These findings as a whole strongly suggest that the cellulose molecules in the native band are selectively cleaved at sharply folded parts by acid, producing fragments of the length of folding periodicity.     

New design for the high-performance drive system for DC brushless motor

The dc brushless motor, permanent magnet-type synchronous motor (PM motor), has been used widely in industrial robots, the machine tools for factory, and factory automations. Therefore, it is more desirable to improve the performance of the PM motor variable speed control system. Although only the torque component current is adjusted as the control method for the PM motor, so-called Vector Control, it is expected that the developed characteristics will be added to the PM motor. In this paper, new driving methods for the PM motor and a new design method for the variable speed control system are presented. The new motor driving methods which bring to the PM motor a new driving performance, e.g., a quick transient response or high-efficiency motor driving, can be implemented by controlling not only the torque component current, but also the magnetizing component current. A developed optimal control theory, i.e., the error system technique, is employed for designing the control system. The control law is endowed with a steady robustness against the variation of the system parameters and the ability of compensating the delay time due to the control processing. The effectiveness of the proposed method is confirmed by simulations and experiments.     

Contrasting effects of an aminobisphosphonate, a potent inhibitor of bone resorption, on lipopolysaccharide-induced production of interleukin-1 and tumour necrosis factor alpha in mice

PURPOSE: To evaluate whether transient androgen deprivation improves outcome in patients irradiated after radical prostatectomy for locally advanced disease, persistent or rising postoperative prostate specific antigen (PSA), or local recurrence. METHODS AND MATERIALS: Records of 105 consecutive patients who were treated with pelvic irradiation after radical retropubic prostatectomy between August 1985 and December 1995 were reviewed. Seventy-four patients received radiation alone (mean follow up: 4.6 years), and 31 received transient androgen blockade with a gonadotropin-releasing hormone agonist (4) androgen receptor blocker (1) or both (24) beginning 2 months prior to irradiation (mean follow-up 3.0 years) for a mean duration of 6 months. Two of these patients were excluded from further analysis because they received hormonal therapy for more than 1 year. Patients received a prostatic fossa dose of 60-70 Gy at 2 Gy per fraction; 48 patients also received pelvic nodal irradiation to a median dose of 50 Gy. Survival, freedom from clinical relapse (FFCR), and freedom from biochemical relapse (FFBR) were evaluated by the Kaplan-Meier method. Biochemical relapse was defined as two consecutive PSA measurements exceeding 0.07 ng/ml. RESULTS: At 5 years after irradiation, actuarial survival for all patients was 92%, FFCR was 77%, and FFBR was 34%. FFBR was significantly better among patients who received transient androgen blockade before and during radiotherapy than among those treated with radiation alone (56 vs. 27% at 5 years, p = 0.004). FFCR was also superior for the combined treatment group (100 vs. 70% at 5 years, p = 0.014). Potential clinical prognostic factors before irradiation did not differ significantly between treatment groups, including tumor stage, summed Gleason histologic score, lymph node status, indication for treatment, and PSA levels before surgery or subsequent treatment. Multivariate analysis revealed that transient androgen deprivation was the only significant predictor for biochemical failure. CONCLUSION: This retrospective study of irradiation after radical prostatectomy suggests that transient androgen blockade and irradiation may improve freedom from early biochemical and clinically evident relapse compared to radiotherapy alone, although more prolonged follow-up will be needed to assess durability of impact upon clinical recurrence and survival rates.     

Requirements for intelligent network service operations

A service operation architecture and operation system platform are proposed that separate commonly used information from operations functions, and that use access control functions. This enables new applications to be developed more easily and increases operating efficiency. The operation system platform is related to several surrounding platforms, and requires standardized reference points such as CMIS/P and managed objects. A managed object methodology is a suitable approach for accessing the operation system platform, and managed object classes and methods are proposed for intelligent network service operations. This architecture and platform will allow telecommunication to meet the demands created by intelligent networks for enhanced customer services, more reliable operation systems, and lower development costs. On the basis of proposed platform, service surveillance prototype systems for free-phone services have already been developed, and the next versions of the service operations systems for virtual private networks services are being developed.