A New Method for Etching Surfaces of Bearings and Other Machine Elements

1980 ◽  
Vol 102 (3) ◽  
pp. 395-400 ◽  
Author(s):  
G. G. Hirs ◽  
J. IJ. Sonneveld
Keyword(s):  
Flow Velocity ◽  
Etching Rate ◽  
Theoretical Work ◽  
New Method ◽  
Curved Surfaces ◽  
Sliding Bearings ◽  
Photochemical Etching ◽  
Machine Elements ◽  
Template Design ◽  
Made In

The method relates to the production of shallow recesses in surfaces by etching. Recesses in metal surfaces are particularly suitable for use in sliding bearings for rotating components and in some other machine elements. Frequently, such recesses have a depth of 10 microns or more and are made in the form of intricate groove patterns on curved surfaces. According to the new method, etching fluid is caused to flow by means of a flow guiding template onto areas determined by this template along the surface to be etched. The etching rate on the areas to be etched is controlled by adjustment of the flow velocity of the etching fluid and the slit height of the flow guiding template. The recesses or grooves are deeper when the flow velocity of the etching fluid and the slit height are both higher. The paper gives a brief description of the new etching method and a comparison with other fabrication methods such as photochemical etching and electro-chemical machining. The new method appears to be preferable to others for large series production. The paper concludes with theoretical work in which the etching process is explained in terms of mass transfer by connective diffusion and with some experimental results using a simplified flow guiding template design.

scholarly journals Polyadic Cantor Fractal Ultrasonic Lenses: Design and Characterization

2018 ◽  
Vol 8 (8) ◽  
pp. 1389 ◽  
Author(s):  
Sergio Castiñeira-Ibáñez ◽  
Daniel Tarrazó-Serrano ◽  
Jose Fuster ◽  
Pilar Candelas ◽  
Constanza Rubio
Keyword(s):  
Thermal Ablation ◽  
Dynamic Control ◽  
Design Parameters ◽  
Medical Applications ◽  
Curved Surfaces ◽  
Ultrasonic Beam ◽  
Acoustic Lens ◽  
Acoustic Profile ◽  
Made In

Traditional acoustic lenses modulate the ultrasonic beam due to their curved surfaces and the refractive material of which they are made. In this work, a different type of acoustic lens, based on Polyadic Cantor Fractals (PCF), is presented and thoroughly analyzed. These new Polyadic Cantor Fractal Lenses (PCFLs) are completely flat and easy to build, and they present interesting modulation capabilities over the acoustic profile. The dependence of the focusing profile on the PCFL design parameters is fully characterized, and it is shown that certain design parameters provide a dynamic control, which is critical in many medical applications such as thermal ablation of tumors.

The Research of a New Method for Manipulating Magnetic Beads through Multi-Layered Flat Micro-Coils Coupled with Permanent Magnet

2013 ◽  
Vol 753-755 ◽  
pp. 1571-1575
Author(s):  
Zhi Hua Liu ◽  
Yu Feng Huang ◽  
Jian Peng Li ◽  
Xin Wei Xu
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Flow Velocity ◽  
Magnetic Beads ◽  
Magnetic Bead ◽  
New Method ◽  
Viscous Resistance ◽  
Main Factors ◽  
The Magnetic Field

Magnetic bead droplet's non-contacted manipulation can be realized in Electromagnetic MEMS, but how to achieve magnetic beads manipulation is the major problem. A new method of multi-layered flat coils coupled with permanent magnet was proposed. Firstly, the theory of magnetic bead manipulation was analyzed and the main factors affected the magnetic beads manipulation was identified; then the magnetic field of multi-layered flat coils and Stokes viscous resistance of magnetic beads were analyzed and simulated quantificationally; finally the magnetic bead capture area was got under different flow velocity. Consequently the feasibility and correctness of this method was verified.

scholarly journals Extracorporal modified ascitic fluid reinfusion in treatment of resistant ascites in liver cirrhosis

2017 ◽  
Vol 176 (3) ◽  
pp. 32-37
Author(s):  
I. E. Onnintsev ◽  
S. Ya. Ivanusa ◽  
A. V. Khokhlov ◽  
A. A. Sokolov ◽  
A. V. Yankovskiy
Keyword(s):  
Liver Cirrhosis ◽  
Portal Hypertension ◽  
Blood Plasma ◽  
Ascitic Fluid ◽  
Intravenous Infusion ◽  
Sodium Excretion ◽  
Albumin Level ◽  
New Method ◽  
Diuretic Resistance ◽  
Made In

OBJECTIVE. The aim of the study was to estimate the efficacy of new method of reinfusion of extracorporeal modified ascitic fluid in therapy of diuretic resistance ascites in patients with liver cirrhosis and portal hypertension syndrome. MATERIAL AND METHODS. An analysis of treatment was made in 83 patients, who underwent laparocentesis and ascitic fluid evacuation. The patients were divided into two groups. Laparocentesis and fractional evacuation of ascitic fluid were carried out for the patients of the first group (n=40). This procedure was followed by intravenous infusion of 25 % albumin (10 g of albumin on each 2 litres of removed fluid) in order to make up losses of protein. Laparocentesis and ascitic fluid evacuation with following extracorporal processing and reinfusion were performed for the second group of patients (n=43). RESULTS. There was noted an increase of day diuresis from (620,0 ± 110,0) ml to (2,2 ± 0,4) l compared with the first group from (780 ± 80) ml to (1,2 ± 0,5) l and rise of sodium excretion (132 ± 7) mmol/l compared with the first group - (120 ± 6) mmol/l. An average molecular peptide concentration was decreased in blood plasma to (0,254 ± 0,098) units in the second group and it counted (0,298 ± 0,045) units in the first group. CONCLUSIONS. Reinfusion of extracorporeal modified ascitic fluid was more effective than conventional correction of albumin level and electrolytes disturbances against a background of ascitic fluid evacuation.

scholarly journals Task-evoked pupil responses reflect internal belief states

2018 ◽  
Author(s):  
O. Colizoli ◽  
J.W. de Gee ◽  
A.E. Urai ◽  
T.H. Donner
Keyword(s):  
Pupil Diameter ◽  
Theoretical Work ◽  
Prediction Errors ◽  
Decision Confidence ◽  
Uncertain Evidence ◽  
Recent Theoretical Work ◽  
The Face ◽  
Belief States ◽  
State Of The Environment ◽  
Made In

AbstractPerceptual decisions about the state of the environment are often made in the face of uncertain evidence. Internal uncertainty signals are considered important regulators of learning and decision-making. A growing body of work has implicated the brain’s arousal systems in uncertainty signaling. Here, we found that two specific computational variables, postulated by recent theoretical work, evoke boosts of arousal at different times during a perceptual decision: decision confidence (the observer’s internally estimated probability that a choice was correct given the evidence) before feedback, and prediction errors (deviations from expected reward) after feedback. We monitored pupil diameter, a peripheral marker of central arousal state, while subjects performed a challenging perceptual choice task with a delayed monetary reward. We quantified evoked pupil responses during decision formation and after reward-linked feedback. During both intervals, decision difficulty and accuracy had interacting effects on pupil responses. Pupil responses negatively scaled with decision confidence prior to feedback and scaled with uncertainty-dependent prediction errors after feedback. This pattern of pupil responses during both intervals was in line with a model using the observer’s graded belief about choice accuracy to anticipate rewards and compute prediction errors. We conclude that pupil-linked arousal systems are modulated by internal belief states.

Application of Superfinishing to Curved Surfaces

2013 ◽  
Vol 581 ◽  
pp. 241-246 ◽  
Author(s):  
Kohichi Miura ◽  
Takazo Yamada ◽  
Masayuki Takahashi ◽  
Hwa Soo Lee
Keyword(s):  
Surface Finishing ◽  
Curved Surfaces ◽  
Application Method ◽  
High Efficient ◽  
Machine Elements ◽  
Grinding Stones ◽  
Cylindrical Geometries ◽  
Precise Machine ◽  
Short Time

It is well known that the superfinishing is a high efficient surface finishing method to cylindrical workpieces. In this method, grinding stones are pressed to the outside of cylindrical surfaces. Rotating cylindrical workpieces and making relative vibrations between grinding stones and ground surfaces in the directions of the center lines of workpiece rotations, the cylindrical surfaces are ground and mirror surfaces are realized relatively in short time. Therefore, this finishing method is widely applied to the finishing of precise machine elements. However, this method cannot be applied in case of that the workpiece which is not simple cylindrical geometries so far. In this study, a new application method of superfinishing to the cylindrical workpieces having curved parts is proposed and its performance is discussed experimentally.

scholarly journals Spectral analysis of flow velocity in the contralateral artery during coronary angioplasty: A new method for assessing collateral flow

1993 ◽  
Vol 21 (7) ◽  
pp. 1574-1582 ◽  
Author(s):  
Jan J. Piek ◽  
Jacques J. Koolen ◽  
Alexander C.Metting van Rijn ◽  
Hans Bot ◽  
Gerard Hoedemaker ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Flow Velocity ◽  
Coronary Angioplasty ◽  
New Method ◽  
Collateral Flow

Some Methodological Modifications of the Technicon "SMA 12/60 AutoAnalyzer" System

1972 ◽  
Vol 18 (7) ◽  
pp. 630-642 ◽  
Author(s):  
Tevfik K Bigat ◽  
Abraham Saifer
Keyword(s):  
Alkaline Phosphatase ◽  
Glucose Oxidase ◽  
Aspartate Aminotransferase ◽  
Inorganic Phosphate ◽  
New Method ◽  
Green Method ◽  
Bromcresol Green ◽  
Made In

Abstract Methodological modifications have been made in our "SMA 12/60 AutoAnalyzer" system, to improve the reproducibility and accuracy of six commonly performed procedures. These include glucose with the glucose oxidase method, albumin with the bromcresol green method, and alkaline phosphatase with the sodium thymolphthalein monophosphate method. We have also modified the composition of the reagents used in the determination of protein, inorganic phosphate, and aspartate aminotransferase. A general approach that is useful for adapting a new method to a multichannel AutoAnalyzer system is discussed.

Parallel synthesis of meso-substituted corroles and meso-substituted [22]pentaphyrins(1.1.1.0.0) from diacyl-dipyrromethanes

2003 ◽  
Vol 07 (04) ◽  
pp. 239-248 ◽  
Author(s):  
Daniel T. Gryko ◽  
Mariusz Tasior ◽  
Beata Koszarna
Keyword(s):  
Functional Groups ◽  
Parallel Synthesis ◽  
New Method ◽  
Large Excess ◽  
Tertiary Amides ◽  
Moderate Yield ◽  
Made In

A new method was devised for the synthesis of 1,9-diacyldipyrromethanes - crucial intermediates in the synthesis of meso-substituted corroles and porphyrins with different substituents. The diacylodipyrromethanes formation involves acylation of dipyrromethanes with salts made in situ from POCl 3 and tertiary amides. This modified Vilsmeier approach gives higher yields and no concomitant formation of monoacyldipyrromethanes as compared with the Grignard route. Moreover, compounds possessing groups previously inaccessible ( CN , NO 2 etc.) can be synthesized. During optimization of the transformation of diacyldipyrromethanes into meso-substituted corroles it was found that if macrocyclization reaction mediated by DDQ is performed in the presence of large excess of pyrrole, meso-substituted [22]pentaphyrins(1.1.1.0.0) can be obtained in moderate yield. The currently described procedure constitutes a new method for the synthesis of these valuable porphyrinoids. Corroles possessing interesting, easy to transform, functional groups were obtained in 3-40% yield.

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