Multiphase microstructure in steel bars produced by dieless drawing

In the dieless drawing technology the drawing dies are replaced by a heating device, generally by an induction coil. Bars of different cross-sections, round or even rectangular, with varying dimensions along the length can be produced. By using a cooling box in connection with the heating device this deformation process may also be employed for a thermomechanical treatment of steels. The special cooling strategy with low cooling rates at high temperatures (during ferrite formation) and higher cooling rates at lower temperatures favours the formation of multiphase microstructures (ferrite - bainite/martensite) with a low yield strength but a strong work hardening effect. The experiments were carried out on rods with a diameter of 16 mm of a plain low carbon steel (0.1%C, 0.7%Mn). The specimens were locally heated up to the maximum temperature ?_max that initiates the dieless drawing process, and subsequently cooled with different coolants. The change in yield strength and tensile strength and the corresponding change in the ratio of both could be achieved by variation of ?_max and the cooling conditions. The multiphase microstructure with desired mechanical properties was produced at a strain of about more than 0.45 within the region of ?_max ≈ 900–1000°C and a finale cooling rate of about 20 K/s.     

Flax fibers as a raw material: How to bleach efficiently a non-woody plant to obtain high-quality pulp

Fiber crops constitute a good alternative to wood fiber for manufacturing pulp and paper. In fact, fiber plants like flax surpass wood fiber in some technical respects and also in the environmental benignity of their processing. In this work, flax fiber was subjected to environmentally friendly bleaching sequences in order to obtain a high-quality pulp. The totally chlorine-free sequences (TCF) used for this purpose (LE and LRE) included an enzyme treatment with laccase in the presence of HBT as mediator (L stage), an alkaline extraction (E stage) and a reductive treatment with NaBH₄ (R stage). The operating conditions for the L stage (laccase and HBT doses, reaction time and oxygen pressure) were optimised by using a sequential statistical plan to assess their influence on pulp properties after the E stage.Mathematical models accurately predicting brightness and kappa number in terms of the previous four variables were developed based on which the most influential factors were the laccase and HBT rates, and treatment time. By contrast, oxygen pressures of 0.2–0.6 MPa in the reactor had no effect on brightness or kappa number. The flax pulp obtained contained some oxidized cellulose that was partially degraded in the alkaline extraction step and reduced viscosity as a result. The viscosity loss associated with the presence of oxidized cellulose in the control and enzyme-treated pulp samples was efficiently recovered by using a reductive stage with sodium borohydride. Effluent was also analysed in order to assess the environmental impact of the process.     

科马格街区空间改造

与其他历史悠久的城市一样，丹麦首都哥本哈根市是有序和随意的规划设计共同作用的结果，它不仅继承了城市的人文建筑遗产，还体现了城市有机发展的过程。本项目位于哥本哈根市中心，紧挨着斯特罗里耶步行街。我们的设计力求在历史与现代、本地化与国际化以及动态与静止之间寻找平衡。黑白相间的石材铺装，营造出视觉上的美学连贯性。     

科马格街区空间改造KфBMAGERGADE

与其他历史悠久的城市一样,丹麦首都哥本哈根市是有序和随意的规划设计共同作用的结果,它不仅继承了城市的人文建筑遗产,还体现了城市有机发展的过程.本项目位于哥本哈根市中心,紧挨着斯特罗里耶步行街.     

Welcoming them home: Supporting service members and their families in navigating the tasks of reintegration.

To date, more than 1.3 million service members have served in the Global War on Terrorism. These men and women and their families face a range of stressful situations and must navigate many important tasks after a deployment. This article outlines four of the tasks of reintegration: redefining roles, expectations, and division of labor; managing strong emotions; abandoning emotional constriction and creating intimacy in relationships; and creating shared meaning. For each task, potential challenges are discussed and suggestions for how psychologists can support families are described. In addition, potential red flags and indicators that more intensive services may be warranted are reviewed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transoral metal implant removal after ventral C2/C3 spondylodesis in pharyngo-vertebral fistula

A 26-year-old man sustained a C2 arc fracture. Ventral spondylodesis using an H-plate was performed. The patient developed a pharyngovertebral fistula which remained undetected for 1 year. Spontaneous fusion of C3/C4 and osteolysis of the cortical block occurred. The fistula was demonstrated intraoperatively and the implant was transorally removed. No further problems occurred after this unusual method of treatment. The anatomy of the cervical spine, special problems of intensive care patients and the use of proper instrumentation are discussed.     

Study of Deformation Phenomena in TRIP/TWIP Steels by Acoustic Emission and Scanning Electron Microscopy

Modern metastable steels with TRIP/TWIP effects have a unique set of physical-mechanical properties. They combine both high-strength and high-plasticity characteristics, which is governed by processes activated during deformation, namely, twinning, the formation of stacking faults, and martensitic transformations. To study the behavior of these phenomena in CrMnNi TRIP/TWIP steels and stainless CrNiMo steel, which does not have these effects in the temperature range under study, we used the method of acoustic emission and modern methods of signal processing, including the cluster analysis of spectral-density functions. The results of this study have been compared with a detailed microstructural analysis performed with a scanning electron microscope using electron backscatter diffraction (EBSD).