Advanced flaw production method for in-service inspection qualification mock-ups

One of the key issues in in-service inspection qualification is the representativeness of the defects used in qualification specimens. The best representativeness is achieved with realistic defects. However, present specimen production techniques have some significant weaknesses, such as unrealistic defects or additional alterations induced in the surrounding material. Specimens manufactured, for example, by weld implantation or with weld solidification defects always result in one or more extra weld interfaces. These interfaces can be detected by NDT. To overcome problems with the current specimens, a new defect manufacturing technique was developed. The new technique produces natural, representative defects without introducing additional weld metal or other unwanted alterations to the specimen.The new method enables artificial production of single, separate fatigue cracks by thermal loading. The method is based on a natural thermal fatigue damage mechanism and enables production of real cracks directly into the samples. Cracks are produced without welding or machining and without any preliminary surface treatment or artificial initiator such as a notch or a precrack. Single crack or a network of cracks can be induced into the base material, welded areas, HAZ, weld claddings, threaded areas, T-joints, etc. The location, orientation and size of produced cracks can be accurately controlled. Produced cracks can be used to simulate different types of service-induced cracks such as thermal fatigue, mechanical fatigue and stress corrosion cracks. It is shown that artificially produced thermal fatigue cracks correspond well with the real, service-induced cracks and overcome the problems of traditional qualification specimen manufacturing techniques.     

The pedophilic offender with antisocial character

The purpose of the study was to clarify how pedophilic offenders with antisocial character (psychopathy) differ from "ordinary" pedophilic offenders, among whom there are many persons with immaturity and contact difficulties. For this purpose all pedophilia cases subjected to mental examination during a period of 25 years were investigated. Of these 81 cases, 38 could be regarded as antisocial characters on the basis of the current diagnostic criteria. The others were regarded as controls. The criminals with antisocial character had also been involved in other kinds of crimes and had had hyperactivity problems more often than controls. The controls were often immature, had a low intelligence, and were less able to have relations with adult people than were antisocial characters. However, according to the present results, these features might also make criminals with antisocial character more susceptible to pedophilia.     

Dual origins of Finns revealed by Y chromosome haplotype variation

The objective of this study was to determine effects of photoperiod and age on the circulating concentrations of LH, testosterone (T), thyroxine (T4), and semen production in male turkeys. Male turkeys from 10 or 12 wk of age were maintained under either a long-day (LD) photoperiod of 16L:8D up to 35 wk (LL), or a short-day (SD) photoperiod of 6L:18D to 29 wk and then an LD photoperiod of 16L:8D up to 35 wk of age (SL). Plasma concentrations of both LH and T increased by 17 or 18 wk of age under both photoperiods, but higher levels were attained in the LL group prior to 29 wk of age. Both LH and T levels increased significantly within days in the SL group after the group was switched to LD at 29 wk of age. Higher levels of T4 were present in the LL group prior to sexual maturation. No differences were observed in T4 concentration between lighting treatments after sexual maturation. The LL group first produced semen at 20-22 wk of age, which was about 1 wk earlier than first semen production in the SL group. A significantly larger volume of semen was produced in the LL group at most ages. No further increase in semen production was observed in the first 6 wk after the SL group was switched to the LD photoperiod at 29 wk of age. Pulsatile patterns of LH and T were characterized by serial blood sampling at 13, 23, and 35 wk of age under both the LL and SL photoperiods. The baseline levels of both LH and T in male turkeys were influenced by age and photoperiod. However, pulse characteristics (numbers, duration, and amplitude) of LH did not change with age or lighting treatment, while pulse characteristics of T did change with age. We conclude that exposing male turkeys to an LD photoperiod from 10 or 12 wk of age advanced the age of sexual maturation and induced earlier increased concentrations of LH and T.     

Linkage of antisocial alcoholism to the serotonin 5-HT1B receptor gene in 2 populations

We examined the effects of repeated administration of (S)-alpha-fluoromethylhistidine (FMH), a specific inhibitor of histidine decarboxylase (HDC), on radial maze performance and brain contents of histamine and amino acids in rats. By daily subcutaneous (s.c.) administration of FMH (100 mg/kg), rats showed significant enhancement of a radial maze performance without changes in locomotion. Six days after FMH treatment, the histamine levels both in the cerebral cortex and diencephalon decreased significantly. However, the glutamate and glycine levels significantly increased in the cerebral cortex and hippocampus. These results suggest that FMH enhances the acquisition phase of radial maze study with the increases in glutamate and glycine levels in the cerebral cortex and hippocampus of rats.     

First-principles study of the phosphorous-vacancy pair in silicon

Using first-principles simulations, we investigate the structure and the energetics of the phosphorous-vacancy pair in silicon. Symmetry-unrestricted optimization of the atomic positrons gives an inward relaxation combined with a pairing component for both neutral and negatively charged defects. We find a small outward relaxation in the charge state transition from the negative to the neutral phosphorous-vacancy pair. We calculate the defect formation energies and the binding energy of the phosphorous atom to the silicon vacancy, and the heat of solution of phosphorous to silicon. The activation ] energy for phosphorous diffusion is discussed.     

Creasability testing by inclined rules — a base for standardized specification of paperboard

In die cutting manufacture of paperboard it is necessary to apply the correct creasing conditions, e.g. neither too small nor too big a rule height, in order to achieve sufficiently low folding resistance without any cracks along the folding lines. The most appropriate rule height for a given paperboard is usually determined by trying different rule heights in a series of very time consuming and costly trial and error tests. And, in practice, this procedure must be repeated for each major change in board quality. This report shows that an inclined crease rule, i.e. a rule having a gradually increasing rule height, can be used advantageously to rationalize such tests and to achieve much greater reliability. A folding line produced by such an inclined rule contains both the upper limit for the rule height, i.e. where cracks start to appear, and the lower limit, i.e. where the rule height is obviously too small, and the technical range for achieving a good creasing result is thus clarified in one single test. Illustrative data for two types of paperboard are given as well as some theoretical aspects of the concept of creasability. Considering that the described method not only rationalizes the testing work but also enables more reliable observations to be made than have been possible in the past, the method opens new potentials for effective research and development in the fields of converting, convertibility, die form design, etc. © 1997 John Wiley & Sons, Ltd.     

Thermodynamic assessment of ZnO-SiO2 system

ZnO-containing slags are common in pyrometallurgical processing of the base metals and steel. This caused the interest to the thermodynamics of the ZnO-SiO₂ system. A complete literature survey, critical evaluation of the available experimental data and a thermodynamic optimization of the phase equilibria and thermodynamic properties of the system ZnO-SiO₂ at 1.013×10⁵ Pa are presented. The molten oxide was described as an associate solution. The properties of liquid were reassessed and enthalpy term of the Gibbs energy of solid Zn₂SiO₄ was re-fitted to be compatible with the new data in the willemite primary phase field. The thermodynamic data set agrees well with the recent experimental observations. It can be used for predicting, e.g., the thermodynamic properties and the domains of the phase diagram, like critical point of the liquid miscibility gap, with a better accuracy than using the previous assessments. A set of optimized model parameters were obtained, reproducing the reliable thermodynamic and phase equilibrium data within their experimental errors from 298 K to liquidus temperatures, over the entire composition range. The created database can be used in a Gibbs energy minimization software to calculate the thermodynamic properties and the phase diagram sections of interest.     

高速新概念成形——低定量双层箱纸板,变不可能为可能

介绍了一种全新的、已获专利保护的、用单台混合成形单元生产容器用轻量双层箱纸板的成本效益型的概念。新概念将三个独特的部件和技术结合为一体：新型ValFloPro双层流浆箱、VacuBalence真空辅助成形板和ValFormer靴刮刀混合成形器技术。这个具备分层技术的混合成形新概念将纸机运行速度提高到1400m/min,是生产一流质量轻量箱纸板的一种切实可行的替代方案。     

Tacticity distribution of isotactic polypropylene prepared with heterogeneous Ziegler-Natta catalyst. 2. Application and analysis of SSA data for polypropylene

Accurate characterisation of the tacticity distribution in isotactic polypropylene is important for obtaining better structure property correlations and for the indirect investigation of the active sites in heterogeneous Ziegler-Natta catalysts. In this work, successive self-nucleation and annealing (SSA) DSC measurement is applied for the study of tacticity distribution in polypropylene fractions with varying isotacticity. The results are compared with ¹³C NMR and temperature rising elution fractionation (TREF). Analysis of the lamellar thicknesses and average meso sequence lengths (MSL) revealed that the fractions could be classified into three main groups according to the lamellar structure generated in SSA. The fractions with relatively low isotacticity crystallise mainly by the longest crystallisable sequence of the chain. In more isotactic fractions, the lamellar thicknesses are close to the average crystallisable sequence lengths of the chains. For the highest isotacticity fractions correlation was not found. Because of these differences the correlation between the melting temperature and isotacticity (meso diad-%) was non-linear. Good correspondence between the SSA melting curves and the TREF fractograms was observed.