Thermodynamic Assessment of the Sn-Ti System

Summary.: The knowledge of phase equilibria and thermodynamic properties in the ternary Cu-Sn-Ti system is of technical importance for active brazing filler metals. Thermodynamic descriptions of the binary systems Cu-Ti and Cu-Sn are well established. In this work a self-consistent thermodynamic description of the Sn-Ti binary system has been obtained by fitting critically reviewed thermochemical and phase diagram data. The newest and most consistent lattice stability has been used, and all the intermetallic phases and recent experimental information have been taken into account. The equilibrium measurement on the Sn-rich side and more experimental thermodynamic properties are required for a better thermodynamic description of this system. The evaluated thermodynamic description of the Sn-Ti binary system will serve as part of the thermodynamic database for Cu-Sn-Ti brazing alloy

Women’s Word Use in Pregnancy: Associations With Maternal Characteristics, Prenatal Stress, and Neonatal Birth Outcome

Background: Experiencing high levels of stress during pregnancy can impair maternal well-being and fetal development. Consequently, unbiased assessment of maternal psychological state is crucial. Self-report measures are vulnerable to social desirability effects. Thus, implicit measures, such as word choice analysis, may offer an alternative.Methods: In this longitudinal online-study, 427 pregnant women described their emotional experiences in writing and additionally responded to self-report questionnaires assessing symptoms of prenatal stress and depression. The written texts were analyzed with a computerized text analysis program. After birth, 253 women provided information on birth outcome.Results: Word use differed significantly depending on maternal socioeconomic (e.g., marital status) and pregnancy-related characteristics (e.g., parity). Prenatal stress and depressive symptoms were associated with more frequent use of negative emotion words and words of anxiety, as well as with less first-person plural, but not singular pronoun use. Negative emotion and cognitive mechanism words predicted birth outcome, while self-report measures did not.Conclusion: In addition to self-report measures, word choice may serve as a useful screening tool for symptoms of depression and stress in pregnant women. The findings on pronoun use may reflect women’s changing experience of self-identity during the transition to motherhood

Structural and chemical characterization of the hardening phase in biodegradable Fe-Mn-Pd maraging steels

Fe-Mn-Pd alloys are promising candidates as biodegradable material for use in temporary implant applications. In this study, the hardening phase of Fe-rich martensitic alloys containing 1, 3, and 6 wt.% Pd and a fixed Mn content of 10 wt.% was investigated. All of these alloys show considerable age-hardening upon isothermal aging at 500 °C, exhibiting a behavior characteristic of maraging steels. Atom probe tomography (APT) and x-ray diffraction (XRD) measurements were performed to characterize the composition and crystallography of nanometer-sized precipitates forming in the overaged region of the Fe-Mn-Pd alloys. The precipitates consist mainly of Mn and Pd and the peaks of the intermetallic particles observed in the XRD spectra can be ascribed to the face-centered tetragonal β1-MnPd phase. The precipitation sequence for Fe-Mn-Pd is revealed to be similar to that reported for Fe-Mn-Ni and Fe-Mn-Pt maraging steel

Технологические решения для строительства эксплуатационной наклонно-направленной скважины глубиной 3035 метров на нефтяном месторождении Томской области

Целью данной работы – проектирование эксплуатационной скважины на нефтяном месторождении Томской области. В процессе работы был разработан проект на строительство эксплуатационной нефтяной скважины Урманского месторождении Томской области глубиной 3035 метров. В работе рассмотрен вопрос анализ возможности использования различных сочетаний материалов для рабочей пары ВЗД.The purpose of this work is the design of a production well in an oil field in the Tomsk Region. In the course of work, a project was developed for the construction of an operational oil well at the Urmanskoye field in the Tomsk Region, 3035 meters deep. The paper discusses the possibility of using different combinations of materials for a working pair of PDMs

Corrosion and stress corrosion cracking of ultra-high-purity Mg5Zn

This paper reports on the measurement of the corrosion rate, and the stress corrosion cracking threshold stress, for ultra-high-purity Mg-5Zn. The corrosion rate was higher than the intrinsic corrosion rate of ultra-high-purity Mg, attributed to the quality of the corrosion product film. The threshold stress for stress corrosion cracking, at an applied stress rate of 0.00016 MPa s(-1), was equal to 0.7 times the yield stress in air. The ductility of the cracking indicated that the stress corrosion cracking mechanism was probably hydrogen enhanced localized plasticity. (C) 2015 Elsevier Ltd. All rights reserved