scholarly journals Main trends in intensification of rotor-screw processing of parts

2018 ◽  
Vol 226 ◽  
pp. 01008 ◽  
Author(s):  
Valeriy A. Lebedev ◽  
Georgy V. Serga ◽  
Irina V. Davydova ◽  
Tatiana V. Atoyan ◽  
Irina G. Koshlyakova ◽  
...  
Keyword(s):  
Structural Changes ◽  
Movement Speed ◽  
Processing Application ◽  
Screw Machine ◽  
Working Element ◽  
Productivity Increase ◽  
Screw Rotor ◽  
Production Organization ◽  
Screw Rotors

The ways of productivity increase in details finishing-strengthening processing executed in rotor-screw technological systems are presented. It is shown that the use of rotor-screw machines makes it possible to combine the parts machining using a vibrating field with a large amplitude of oscillations and their transportation in a streamlined form of production organization. Two main directions of rotor-helical processing stimulation are identified: on the basis of structural changes in the screw rotor, as the main working element of the rotor-screw machine and by equipping the screw rotor with activation elements of the process. The classification of screw rotors is presented, which allows purposeful search for the most effective designs of screw rotors and the mechanism is revealed of their influence on the process of parts finishing-hardening processing. Dependence is established for determining the longitudinal movement speed of the parts being processed in the screw rotor. The constructive-technological scheme of the rotor-screw machine is proposed, which allows increase of the productivity of the process and simplification of the design of machines for their implementation, by dismembering the complex screw propulsion of the load mass, which takes place in the screw rotors, into relatively simple in kinematic sense motions. The technological possibilities of rotor-screw processing application for finishing-strengthening operations are presented.

Technological scheme of fi nishing and strengthening of parts in screw working elements machines and rationale for their drive power

2020 ◽  
pp. 400-403
Author(s):  
M.M. Chaava ◽  
G.V. Serga ◽  
Al Obaydi Luai Mohammed Rajab
Keyword(s):  
Rotation Axis ◽  
Technological Scheme ◽  
Drive Power ◽  
Asymmetric Loading ◽  
Working Medium ◽  
Working Element ◽  
Screw Rotor ◽  
Screw Rotors ◽  
Tetrahedral Voids ◽  
Load Mass

Typical technological scheme of the machine for finishing and cleaning and strengthening treatment with working elements in the form of screw rotors mounted from tetrahedral voids is presented. Method for calculating of the drive of these machines is proposed, taking into account the load mass, the working element mass and the load mass located asymmetrically in the working element of the rotation axis, which allows you to calculate the power of the electric motors of machines for finishing, cleaning and strengthening treatment taking into account the actions of symmetrical and asymmetric loading processed parts and particles of the working medium relative to the rotation axis of the screw rotor.

scholarly journals Processing Equipment on the Basis of Operative Parts in the Form of Screw Rotors With Profiled Perimeter

2019 ◽  
Vol 297 ◽  
pp. 02004 ◽  
Author(s):  
Valery Lebedev ◽  
Georgy Serga ◽  
Lidianna Chunakhova ◽  
Mikhail Selemenev
Keyword(s):  
Machine Tools ◽  
Internal Cavity ◽  
Geometrical Shape ◽  
Technological Equipment ◽  
Processing Equipment ◽  
Continuous Rotation ◽  
Screw Rotor ◽  
Working Bodies ◽  
Screw Rotors

The main working body of technological equipment of screw rotor technological systems are screw rotors which present spatial objects with an original geometrical shape of working body perimeter in which component parts and granules of the processing environment carry out simultaneously continuous rotation around the axis of working body and progressive motion, constantly moving along a horizontal axis of working body rotation. This article gives a classification of perimeter forms of working bodies, such as screw rotors, which let to expand technological possibilities of technological equipment and to provide the increase of effectiveness of the production process by means of increase of its amplitude-frequency characteristics. The peculiarity of working bodies in the form of screw rotors is the fact that internal cavity of a rotor has a wavy shape, formed by the sides of a semicircular form. The paper covers on a construction and the principle of operation of machine-tools on the basis of working bodies in the form of screw rotors with a shaped surface on perimeter. The suggested design solutions of processing equipment allow creating highly effective machine-tools for the finishing and strengthening processing.

The pumping characteristics of screw rotors. I. The theory of calculation of the pumping capacity of screw rotors

1987 ◽  
Vol 52 (2) ◽  
pp. 357-371 ◽  
Author(s):  
František Rieger
Keyword(s):  
Present State ◽  
Flow Rate ◽  
Volumetric Flow Rate ◽  
Screw Rotor ◽  
Screw Rotors

This paper summarizes the present state of the theory of calculation of the pumping capacity of screw rotors. The calculation starts from the equation for the volumetric flow rate of the flow between two unconfined plates modified by correction coefficients obtained from the relationships for the flow rate in simpler geometrical configurations to which the screw rotor may be, under certain circumstances, reduced.

scholarly journals FINISH-STRENGTHENING EFFECTIVENESS INCREASE BASED ON USE OF SCREW ROTORS WITH WAVE SURFACE ON PERIMETER

2019 ◽  
Vol 2019 (7) ◽  
pp. 4-10 ◽  
Author(s):  
Валерий Лебедев ◽  
Valeriy Lebedev ◽  
Георгий Серга ◽  
Georgiy Serga
Keyword(s):  
Symmetry Axis ◽  
Rotation Axis ◽  
Acute Angle ◽  
Operating Principle ◽  
Descriptive Geometry ◽  
Wave Surface ◽  
Program Complex ◽  
Engineering Graphics ◽  
Screw Rotors

The paper reports the results of investigations on finish-strengthening improvement. There are offered labor bodies in the form of screw rotors with a wave surface on the perimeter of combined screw rotors in which a rotation axis is located at an acute angle to a symmetry axis. The search of designs of screw rotors with a wave surface on the perimeter was carried out through the methods of descriptive geometry and engineering graphics with the aid of “Compass-3D” program complex. The design and operating principle of machines based on labor bodies in the form of combined screw rotors with a wave surface on a perimeter are shown by the example of the finish-strengthening machine. In the developed classification of machine labor bodies there are presented various forms of their surface on the perimeter.

scholarly journals Implementation of lean in health care environments: an update of systematic reviews

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rui M. Lima ◽  
José Dinis-Carvalho ◽  
Thiago A. Souza ◽  
Elisa Vieira ◽  
Bruno Gonçalves
Keyword(s):  
Health Care ◽  
Cultural Change ◽  
Structural Changes ◽  
Great Majority ◽  
Content Type ◽  
Strategic Objectives ◽  
Starting Point ◽  
Lean Tools ◽  
New Perspective ◽  
Production Organization

Purpose Even though the implementation of lean in health care environments is relatively recent, it has been receiving a lot of attention in recent years. Partly because of the fact that it is a recent field of practise and research and partly because the number of works developed in this field has grown rapidly, it is important to frequently update the perspectives on this field of investigation. Thus, this study aims to review the implementation of lean tools and techniques applied to hospital organizational areas in a five-year period, between 2014 and 2018, complementing some of the most relevant reviews already published. The most important criteria such as tools, methods and principles, hospital areas intervened, improvements and difficulties were assessed and quantified. Design/methodology/approach As starting point for this systematic literature review (SLR), a set of selected pre-existing review publications was used to support the current study and as the ground base for the expansion of the studies about lean health care. The current study contemplated 114 articles from a five-year period between 2014 and 2018. A subset of 58 of these articles was critically assessed to understand the application of lean tools and methods in different hospital areas. Findings The thorough analysis of selected articles show a lack of works in continuous improvement approaches when compared to the application of production organization methods, visual management and diagnosing and problem-solving tools. The reported improvement results demonstrate alignment with the principles and foundations of lean philosophy, but such results are presented in isolated initiatives and without robust evidence of long-term maintenance. Moreover, this study shows an evolution in the number of articles referring to lean implementation in hospital areas, but in its great majority, such articles report isolated implementations in different areas, not spreading those for the global organization. Thus, some of the main recommendations are the need to implement studies on complete flows of patients, drugs and materials, instead of isolated initiatives and strive to promote the cultural change of hospitals through structural changes, following new visions and strategic objectives, supported by real models of continuous structural and sustained improvement. Originality/value The current study develops a new perspective of the articles published under the thematic of lean health care, published in a recent period of five years, which are not completely covered by other works. Additionally, it explicitly applied, in an innovative way, an approach that used a set of previous reviews as the starting point for this SLR. In this way, it integrates approaches and categories from different SLRs, creating a framework of analysis that can be used by future researchers. Finally, it shows the most recent implementations of lean health care, exposing the current trends, improvements and also the main gaps.

Rapid detection and initial characterization of genetic variants of human serum albumin

1991 ◽  
Vol 37 (7) ◽  
pp. 1221-1224 ◽  
Author(s):  
J Merle Sheat ◽  
Robert J Peach ◽  
Peter M George
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Genetic Variants ◽  
Gel Electrophoresis ◽  
Structural Changes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl

Abstract We have studied the detection and classification of genetic variants of human serum albumin by electrophoresis. Samples from 10 patients who were heterozygous for eight different albumin variants were studied by two methods. In agarose gel electrophoresis, each of these variants has an abnormal mobility and can be classified on the basis that structural changes at the N-terminus abolish 63Ni binding. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole serum, glycosylated variants are easily detected because of their greater apparent molecular mass.

scholarly journals Vibration-Based Structural Health Monitoring Using Piezoelectric Transducers and Parametric t-SNE

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1716
Author(s):  
David Agis ◽  
Francesc Pozo
Keyword(s):  
Structural Health Monitoring ◽  
Health Monitoring ◽  
Structural Changes ◽  
Computational Cost ◽  
Principal Component ◽  
Piezoelectric Transducers ◽  
Majority Voting ◽  
Structural Health

In this paper, we evaluate the performance of the so-called parametric t-distributed stochastic neighbor embedding (P-t-SNE), comparing it to the performance of the t-SNE, the non-parametric version. The methodology used in this study is introduced for the detection and classification of structural changes in the field of structural health monitoring. This method is based on the combination of principal component analysis (PCA) and P-t-SNE, and it is applied to an experimental case study of an aluminum plate with four piezoelectric transducers. The basic steps of the detection and classification process are: (i) the raw data are scaled using mean-centered group scaling and then PCA is applied to reduce its dimensionality; (ii) P-t-SNE is applied to represent the scaled and reduced data as 2-dimensional points, defining a cluster for each structural state; and (iii) the current structure to be diagnosed is associated with a cluster employing two strategies: (a) majority voting; and (b) the sum of the inverse distances. The results in the frequency domain manifest the strong performance of P-t-SNE, which is comparable to the performance of t-SNE but outperforms t-SNE in terms of computational cost and runtime. When the method is based on P-t-SNE, the overall accuracy fluctuates between 99.5% and 99.75%.

scholarly journals Automatic Identification of Algal Community from Microscopic Images

2013 ◽  
Vol 7 ◽  
pp. BBI.S12844 ◽  
Author(s):  
Natchimuthu Santhi ◽  
Chinnaraj Pradeepa ◽  
Parthasarathy Subashini ◽  
Senthil Kalaiselvi
Keyword(s):  
Image Processing ◽  
Machine Learning Algorithms ◽  
Algal Community ◽  
Automatic Identification ◽  
Object Boundary ◽  
Algal Communities ◽  
Processing Application ◽  
Segmentation Methods ◽  
Processing Techniques

A good understanding of the population dynamics of algal communities is crucial in several ecological and pollution studies of freshwater and oceanic systems. This paper reviews the subsequent introduction to the automatic identification of the algal communities using image processing techniques from microscope images. The diverse techniques of image preprocessing, segmentation, feature extraction and recognition are considered one by one and their parameters are summarized. Automatic identification and classification of algal community are very difficult due to various factors such as change in size and shape with climatic changes, various growth periods, and the presence of other microbes. Therefore, the significance, uniqueness, and various approaches are discussed and the analyses in image processing methods are evaluated. Algal identification and associated problems in water organisms have been projected as challenges in image processing application. Various image processing approaches based on textures, shapes, and an object boundary, as well as some segmentation methods like, edge detection and color segmentations, are highlighted. Finally, artificial neural networks and some machine learning algorithms were used to classify and identifying the algae. Further, some of the benefits and drawbacks of schemes are examined.

scholarly journals Classification of glomerular pathological findings using deep learning and nephrologist–AI collective intelligence approach

2020 ◽  
Author(s):  
Eiichiro Uchino ◽  
Kanata Suzuki ◽  
Noriaki Sato ◽  
Ryosuke Kojima ◽  
Yoshinori Tamada ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Deep Learning ◽  
Diagnostic Performance ◽  
Structural Changes ◽  
Periodic Acid ◽  
Fine Tuning ◽  
Pathological Findings ◽  
Glomerular Cell ◽  
Majority Decision

AbstractBackgroundAutomated classification of glomerular pathological findings is potentially beneficial in establishing an efficient and objective diagnosis in renal pathology. While previous studies have verified the artificial intelligence (AI) models for the classification of global sclerosis and glomerular cell proliferation, there are several other glomerular pathological findings required for diagnosis, and the comprehensive models for the classification of these major findings have not yet been reported. Whether the cooperation between these AI models and clinicians improves diagnostic performance also remains unknown. Here, we developed AI models to classify glomerular images for major findings required for pathological diagnosis and investigated whether those models could improve the diagnostic performance of nephrologists.MethodsWe used a dataset of 283 kidney biopsy cases comprising 15888 glomerular images that were annotated by a total of 25 nephrologists. AI models to classify seven pathological findings: global sclerosis, segmental sclerosis, endocapillary proliferation, mesangial matrix accumulation, mesangial cell proliferation, crescent, and basement membrane structural changes, were constructed using deep learning by fine-tuning of InceptionV3 convolutional neural network. Subsequently, we compared the agreement to truth labels between majority decision among nephrologists with or without the AI model as a voter.ResultsOur model for global sclerosis showed high performance (area under the curve: periodic acid-Schiff, 0.986; periodic acid methenamine silver, 0.983); the models for the other findings also showed performance close to those of nephrologists. By adding the AI model output to majority decision among nephrologists, the sensitivity and specificity were significantly improved in 9 of 14 constructed models compared to those of nephrologists alone.ConclusionOur study showed a proof-of-concept for the classification of multiple glomerular findings in a comprehensive method of deep learning and suggested its potential effectiveness in improving diagnostic accuracy of clinicians.

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