PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Metallurgy”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1978

[Energy expenditure on basic work-posts in metallurgy].

The paper presents results of measurements of the whole energetic cost on the work-posts recognized by the management as basic. Altogether 121 determinations of energetic cost were performed on 18 different work-posts in two basic divisions of the steelworks. The results revealed that despite a considerable technical progress there is a significant number of work-posts, on which energetic cost exceeds 2600 kcal/8 hr. On these work-posts apart from the great energetic load, other loads, connected with material work environment on character of work, occur. This means that additional factors frequently increase their harmful effects on organism. The magnitude of energetic expenditure on a given work-post establishes the hierarchy of modernizational requirements for the plant's technical services.

Energy Metabolism↗
PubMed1976

Physical properties of a nickel-base alloy prepared by isostatic pressing and sintering of the powdered metal.

The physical and mechanical properties of samples of a nickel-base alloy fabricated by powder metallurgy were determined. The particle sizes of the powders used to make the samples varied from -80/ +200 mesh to -325 mesh. The compaction pressure varied from 138 to 414 MN/m2 and the sintering temperature varied from 1150 to 1250 degrees C. The shrinkage during processing, the porosity, tensile strength, yield strength, elongation, and elastic modulus were used to characterize the samples. The strength of the samples generally increased with decreasing particle size of the powder and increasing compaction pressure and sintering temperatures. The porosity and strength, therefore, could be varied over a wide range by controlling the various parameters. The properties of the samples prepared by powder metallurgy were compared with those of the cast alloy and compact bone. Conditions can be selected that will yield equivalent or better properties by powder metallurgy than by casting.

Bone and Bones↗
PubMed1979

[The supply of wild ruminants with major and trace elements. 1. The cadmium content of winter grazing and the cadmium status of red deer, fallow deer, roes and moulons].

The Cd-determination of 10 different winter grazings for wild ruminants in seven different biotopes showed significant differences of the habitats resulting from the previous Cd-emission of metallurgy smelting non-ferrous metals. The winter grazing of the Tharandt Forest and the Harz mountains contained significantly more Cd than that of the Lower Flaming hills, the western Erzgebirge and the northern agrarian areas. The bark and the tips of conifer twigs, twigs of oak and mountain ash, bilberry and heather plants, i. e. perennial plants resp. parts of plants proved to be particularly rich in Cd. On an average, wild ruminants consume more Cd than domesticated ruminants, which do not consume parts of perennial plants. The rumen contents of all wild ruminants contained, with 0.20 to 0.25 mg/kg dry matter more Cd than could be expected from the content of the grazing. In the Cd-contaminated areas the amount of Cd in the rumen contents too showed the Cd-load. The kidneys, livers and the covering hair of a total of 172 head red deer, roes and mouflons reflected the Cd-load and the dependence of the Cd-level on the age. The Cd-concentration ascertained in the organs of the wild ruminants was compared with that of sheep and cattle. The, on an average, higher Cd-load of the wild ruminants was confirmed. The kidneys of wild ruminants older than five years should, as a general principle, not be eaten and neither should the livers of animals from Cd-contaminated biotopes. The limb defects of mouflons from Cd-contaminated areas are discussed in connection with Cd-induced secondary Cu-deficiency resp. Mn- and Zn-deficiency. A reference is made to further works.

Animal Nutritional Physiological Phenomena↗
PubMed1977

Titanium as a metal for implantation. Part 1: physical properties.

The scientific basis for the use of titanium and its alloys in implant surgery is reviewed, including the structural metallurgy, mechanical properties, corrosion resistance and biocompatibility. The clinical application are discussed in relation to orthopaedic, oral, plastic and reconstructive and cardiovascular surgery.

Corrosion↗
PubMed1979

The porous-surfaced electrode: a new concept in pacemaker lead design.

Three major problems which may be encountered with endocardial pacemaker electrodes are a lack of stable position, a chronic increase in stimulation threshold, and a diminishing magnitude of the sensed endocardial signal. These problems are particularly manifest in the atrium. Having previously shown that porous metal surfaces can support stable tissue ingrowth in both bloodstream and soft tissue environments, we set out todetermine the performance of porous-surfaced endocardial pacing electrodes in the atrial position. In two groups of six dogs each, J-shaped atrial leads with Elgiloy electrode tips (2.3 mm. in diameter, 2.3 mm. in length), having either conventional smooth surfaces (control) or porous surfaces (20 to 50 micron particle size) produced by powder metallurgy techniques, were positioned in the right atrial a-pendage. Stimulation thresholds and P-wave amplitude were repeatedly measured until the dogs were put to death 30 w-eks following implantation. The presence or absence of electrode fixation was observed and the atrial tissue reaction was examined grossly and by both light and scanning electron microscopy (SEM). The porous-surfaced electrodes demonstrated superior long-term stimulation thresholds which, at 30 weeks, averaged less then one third of those in the control group. In addition, the porous group showed a small but significant improvement in the amplitude of the sensed P wave. None of the smooth-surfaced electrodes showed fixation, and the tissue reaction consisted of a thick layer of granulation and fibrous tissue on the underlying endocardium, widely separating the electrode from the myocardium. In contrast, all of the porous-surfaced electrodes were fexed to the endocardium by fibrous tissue ingrowth into the surface pores. This tissue fixation of the electrode tip in close proximity to underlying myocytes explains their superior performance.

Animals↗
PubMed1979

[Double-contrast arthrography in chondropathia patellae--clinical and experimental study on pathogenesis and diagnosis (author's transl)].

This study is based on the evaluation of 250 arthrographies of the patellofemoral joint ("défilé" arthrographs in Ficat's terminology) which were performed because of clinical suspicion of chondropathia patellae and which could be controlled intraoperatively in 30 cases, as well as on examinations employing an etching paste as used in metallurgy and performed on 20 knee-joints of corpses. 46% of the arthrographies showed a ridge-shaped cartilaginous thickening which was not pre-modelled in the osseous structure and which separated the medial facette into a paramedian and a marginal segment and correlated with chondromalacia to a greater degree than patellar dysplasias or secondary osseous changes. This variant, which could not be detected by plain roentgenography, must be considered as a pre-arthrotic deformity on account of the high point-shaped pressure load on the ridge. The findings were fully confirmed by macroscopic examination of the postmortem material.

Adolescent↗
PubMed1979

Solution treatment behavior of Co-Cr-Mo alloy.

Current practice in the manufacture of Co-Cr-Mo alloy total hip prostheses is the use of a solution treatment to increase the ductility of the as-cast alloy. This study is concerned with the reactions encountered during solution treatment at temperatures between 1165-1270 degrees C. These reactions, including incipient melting, a carbide transformation from M23C6 to M6C and sigma-phase formation, have been examined using both qualitative and quantitative metallographic techniques, and are shown to influence the production of a single phase microstructure. As a result, an optimum temperature for solution treatment of 1220 degrees C has been determined. It is further proposed that a reduction in the carbon content of this alloy would improve its solution treatment behavior.

Carbon↗