Schichtbildung beim Feuerverzinken zwischen 435°C und 620°C in konventionellen Zink‐Schmelzen – eine ganzheitliche Darstellung

Layer formation by hot dip galvanizing between 435°C and 620°C in conventional zinc melts – a general presentation For four typical constructional steels with different Si‐content and enamelling steel the layer growth and the structure of the forming coats is examined as a function of the dipping duration, the melt temperature and the thermal pretreatment. The results are discussed with regard to the experimentally determined hydrogen effusion of the steel. For the temperature range from 435°C to 620°C a pattern is presented, which is applicable for the daily work in the normal and high temperature range.     

Neuronal activity in MST and STPp, but not MT changes systematically with stimulus-independent decisions

Recurrent infection with hepatitis C virus (HCV) is almost universal following orthotopic liver transplantation although clinical severity varies. Data on 135 patients who underwent transplantation for hepatitis C cirrhosis were reviewed. We describe a progressive, severe cholestatic form of hepatitis occurring in a subgroup of patients with recurrent hepatitis C. Ten patients with severe recurrent hepatitis C were identified; 1 has died, 1 awaits retransplantation, and 8 have undergone retransplantation. All 10 developed severe progressive cholestatic hepatitis, with a mean rise in bilirubin to 24.7 mg/dL at the time of retransplantation. Histology at initial recurrence was of mild hepatitis without evidence of rejection. The failed grafts showed either cirrhosis or confluent hepatic necrosis. The onset of cholestasis preceded retransplantation by less than 5 months. Our study suggests that a minority of patients with recurrent hepatitis C after undergoing liver transplantation develop a severe progressive cholestatic hepatitis and liver failure.     

An approach to cyclic plasticity and deformation-induced structure changes of electrodeposited nickel

Bulk nickel samples, produced by electrodeposition, resulting in different initial structure properties, were experimentally studied by X-ray diffraction, as well as by scanning and transmission electron microscopy. Attempts are made to correlate the mechanical behaviour during cyclic plastic deformation with the response of the microstructure. A special effort is made to examine the influence of grain size and internal stresses on the deformation processes.     

Lower extremity manifestations of vascular disease

All podiatrists are required to know the anatomy and pathophysiology of vascular pathology because it is the leading cause of morbidity and mortality in the western world and a frequent complaint of podiatry patients. Podiatrists have a unique opportunity to reduce the risk of lower extremity vascular pathology, specifically PVD, by encouraging proper diet and exercise in the podiatric patient. Because the next century will bring a population explosion of older people, particular attention must be paid to the multiple and complex disorders that impair functional independence and compromise quality of life--one of the most important disorders being vascular disease. Successful treatment depends on recognition of lower extremity pathology (whether it be arterial, venous, or lymphatic) and the possible suprastructural causes and timely referrals to a vascular specialist when indicated.     

Polymers containing formamidine groups

Summary Aliphatic polyformamidines have been synthesized by reaction of aliphatic diamines with triethyl orthoformate in presence of catalytic amounts of acetic acid. The reaction has been carried out in DMSO at 180°C. The polymer structure has been confirmed by IR and NMR spectroscopy. For determination of molecular weights ¹H NMR end group signals have been used.     

Tribomechanische und -chemische Vorgänge an dem Wälzlagerstahl 100 Cr 6

Tribological Processes of the Ball Bearing Steel 100 Cr 6 . Tribomechanical and tribochemical processes of the ball bearing steel 100 Cr 6 were investigated under the influence of ultra high vacuum and different gases by the pin/ring method. The conditions for adhesive wear indicated by prow formation were optimal in ultra high vacuum. Pressures of oxygen, nitrogen and air greater than 10^?6 Pa increase the lubrication by formation of thin films, measured by ellipsometry. Increasing nitrogen pressure produces a surface hardening, which can be observed by nitrided wear particles. The presence of pure oxygen creates permanently oxide films with a thickness of 10 nm. This causes abrasive wear.     

Analysis and design of TEM-line antennas

A novel antenna, the TEM-line antenna, is discussed and analyzed. The TEM-line antenna in its present principal form consists of small half-loops mounted perpendicular to a ground plane and interconnected with transmission lines. Adjusting the dimensions of the half-loops and/or the transmission line lengths provides considerable flexibility in design for a wide range of applications, primarily at VHF frequencies and above. The present geometrical form of the TEM-line antenna is the result of several years' investigation of various evolutionary forms of the TEM line. Most of this past work has heretofore been unavailable in the open literature and, therefore, is summarized in this paper. An exact analysis based on the principle of reaction is presented and applied to three-element coplanar configurations. The analysis includes the effects of cable and conductor losses and readily provides for the calculation of antenna efficiency. Numerous design data have been obtained subject to the constraint that the antenna performance be optimum with respect to both the gain in a specified direction and the VSWR. These design data have been tabulated and are presented in a form that should be useful to the antenna designer.