scholarly journals Hardened Steels and Their Machining

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 182
Author(s):  
Karel Osička ◽  
Josef Chladil
Keyword(s):  
Cubic Boron Nitride ◽  
Tool Material ◽  
Hardened Steel ◽  
Engineering Industry ◽  
Technical Equipment ◽  
Correct Operation ◽  
Assembly Unit ◽  
The Subject ◽  
Bearing Rings

This article discusses the issue of hardened steel machining. Many components in the engineering industry use hardening as the final heat treatment. These components usually occupy a significant position in a given assembly unit. They guarantee the correct operation of the entire technical equipment in total cooperation with other components. The quality of these components depends on the integrity of their surface. The production of these parts is usually carried out by traditional technological procedures. Clearly, an example of such a technology is grinding. However, this article discusses the application of other finishing technologies using a tool material made of cubic boron nitride (CBN). The technology used is finishing turning with subsequent tumbling technology. The subject of the evaluation is the integrity of the surface. In this part of the experiments, there are mainly individual parameters of surface roughness. Compared components are bearing rings, in this case the inner surface of the housing ring.

The production of a plane surface, as illustrated by specula from some early Newtonian telescopes

1983 ◽  
Vol 37 (2) ◽  
pp. 147-166 ◽  
Keyword(s):  
Cast Iron ◽  
Plane Surface ◽  
Hardened Steel ◽  
Precision Engineering ◽  
Flat Surfaces ◽  
Optical Instruments ◽  
Secondary Mirror ◽  
The Subject ◽  
Definition Of

THE construction of accurate paraboloidal mirrors for reflecting telescopes has been the subject of much attention from physicists, practical opticians, and historians of science. However, the paraboloidal primary must be combined with a secondary mirror to give any form of working telescope other than the Herschelian design, and the quality of this secondary is every bit as important to the definition of the final image. In the Newtonian reflector the secondary mirror takes the form of a plane surface of elliptical outline. Historical specula therefore provide a practical record of attempts to achieve a perfectly flat solid surface— an undertaking which has often proved more difficult than making mirrors of a curved figure. Plane surfaces were subsequently required in many optical instruments besides telescopes, such as prisms and diffraction gratings. Then, in the early decades of the nineteenth century, another field of application was created when Maudslay, Whitworth and others realized the need for accurately flat surfaces in precision engineering and toolmaking. To test their products and ensure interchangeability they had to produce plane surfaces upon cast iron ‘surface plates’ and the hardened steel anvils of screw micrometers.

scholarly journals Cutting Force When Machining Hardened Steels

2021 ◽  
Author(s):  
Karel Osička ◽  
Josef Chladil ◽  
Petra Sliwková ◽  
Jan Zouhar
Keyword(s):  
Cutting Force ◽  
Surface Quality ◽  
Structural Equation ◽  
Cubic Boron Nitride ◽  
Technical Equipment ◽  
Hardened Steels ◽  
Thrust Bearings ◽  
Rolling Elements ◽  
Hardened State

This article deals primarily with the problem of determining the cutting force when machining hardened steels. Secondary issues are focused on the evaluation of surface quality on machined samples and the recommendation of cutting conditions. A wide variety of components are used in engineering, the final heat treatment of which is hardening. These components are usually critical in a particular product. The quality of these components determines the correct functioning of the entire technical equipment and ultimately its service life. In our case, these are the core parts of thrust bearings, specifically the rolling elements. The subject of the experiment is machining these components in the hardened state with cubic boron nitride tools and continuous measurement of the cutting force using a dynamometer. The following evaluation assesses the surface quality by both touch and non-touch methods. A structural equation with appropriate constant and exponents was then constructed from the data obtained using the dynamometer.

Research of Technology of Cutting Hardened Steel in HSM

2011 ◽  
Vol 338 ◽  
pp. 701-705
Author(s):  
Xiao Jun Zhu ◽  
Wen Sheng Xia
Keyword(s):  
High Speed ◽  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Tool Material ◽  
Main Tool ◽  
Hardened Steel ◽  
Detection Methods ◽  
Tool Geometry ◽  
High Speed Milling ◽  
Coated Cemented Carbide

The key technology of the cutter that cutting hardened steel was researched by high speed milling machining method. At first ,three cutting elements of high speed milling machining was narratived, and we can obtain the principle of selection of parameters of cutting velocity, feed per tooth, longitudinal cutting depth and cutting width of axial, etc. With HSM ,we discussed the performance and selection points of tool material of coated cemented carbide, ceramic, cubic boron nitride , synthetic diamond and so on, and obtained the effect of the main tool geometry for the cutting process in HSM. The second, it analysised type and reason of damage of high speed cutting tools, and introduced three detection methods of tools. Finally, it was summarized and concluded.

scholarly journals Značajke tehničke opremljenosti grada Zadra

Geoadria ◽  
2016 ◽  
Vol 21 (2) ◽  
pp. 237
Author(s):  
Silvija Šiljeg ◽  
Fran Domazetović ◽  
Ana Pejdo
Keyword(s):  
Inner City ◽  
Historical Development ◽  
Road Transport ◽  
Transport Infrastructure ◽  
Technical Equipment ◽  
City Development ◽  
Level Of Satisfaction ◽  
The Subject ◽  
The City

The subject of the research is the satisfaction of inhabitants with the quality of technical equipment in the City of Zadar based on ten representative variables. Satisfaction level was examined using subjective methods at the level of statistical circles in the City of Zadar. An overview of the historical development of the city transport infrastructure is given in the theoretical part of the paper. A special emphasis was placed on road transport as the most commonly used form of inner city transport and the transport outside the city. In this research the problem infrastructural points was determined, and statistical circles that stand out for the highest and lowest satisfaction with transport infrastructure were highlighted. High and low values of satisfaction were determined as possible future guidelines for the city development. Based on all relevant data it was concluded that the level of satisfaction in general is rather high even though there are significant differences between statistical circles.

Measuring Service Quality in The Context of Higher Education in Vietnam

2013 ◽  
pp. 77-90
Author(s):  
Yen Nguyen Thi Hoang
Keyword(s):  
Higher Education ◽  
Service Quality ◽  
Exploratory Study ◽  
Measurement Scale ◽  
Education Service ◽  
The Subject

This paper focuses on the understanding of service quality in the context of Vietnamese universities. It proposes an approach for measuring the quality of the higher education service provided by universities in Vietnam. Firstly, an exploratory study was conducted. Then, the set of items which were generated became the subject of a questionnaire that was then administered to 675 students of a Vietnamese university to determine the dimensions of higher education service quality in this context. The obtained results permit us to appropriate a measurement scale which is slightly different from the SERVQUAL scale widely known as the standard for measuring service quality. The results also show that tangible elements, responsiveness and assurance seem to be three specific dimensions of the higher education service of Vietnamese universities.

Thomas More’s Correspondence in a Spanish Ambiance

Moreana ◽  
2002 ◽  
Vol 39 (Number 149) (1) ◽  
pp. 41-60 ◽  
Author(s):  
Eugenio M. Olivares Merino
Keyword(s):  
The Subject ◽  
Selection Of

The recent reprinting of Álvaro de Silva’s 1998 edition of a selection of More’s letters prompts the author to examine the subject of Spanish translations of More, and of de Silva’s general commentary on More’s correspondence and on his relationship to other humanists. The author reflects on aspects of More’s personality as exposed in his letters and uses what he finds as a corrective to several biographical misconceptions. He points out the strengths and weaknesses of de Silva’s work and compares it with that of other translators, particularly Elizabeth Rogers, and notes the particularly Spanish quality of de Silva’s edition.

From the Synergy to the Discrimination - Analysis of Attitudes and Decisions of the Prison Staff Towards Muslim Prisoners in the Context of Multicultural Education

2016 ◽  
Vol 2 (2) ◽  
pp. 81
Author(s):  
Arkadiusz Urbanek
Keyword(s):  
Multicultural Education ◽  
Social Relations ◽  
Ethnically Diverse ◽  
Prison Staff ◽  
Professional Activities ◽  
Personal Attitudes ◽  
The Subject ◽  
Pragmatic Aspects ◽  
Diverse Groups

The aspiration to keep the synergy in relations between majorities and minorities repeatedly emerges as the cause of conflicts in social relations. It is also a subject of the interest of the multicultural education, particularly in countries of Eastern Europe, building contacts with the culturally and ethnically diverse groups to a wider scale. Relations in culturally, religiously and ethnic diverse societies, are becoming more and more related to the personal attitudes and a given policy. These issues acquire in the prison circumstances even greater significance, as given moods and personal attitudes of the prison staff create the pragmatic aspects of the professional activities addressed to the sentenced. Additionally, the key role is played by the quality of the penitentiary policy and the legal culture. The article presents the comparative analysis of the research carried out in 2016 amongst the prison staff in Poland. The subject of the research concerned attitudes that influence the decisive processes. The personal relations have been analyzed in the context of the relation with the sentenced Muslims. The aim of the research was not only to reveal the quality of the decisions concerning the sentenced Muslims, but also the sources of such decisions. The latter, in consequence, may shift, as the research results prove, towards synergy or discrimination. The diversification of the discrimination was one of the intriguing aspects, disclosed at various levels that not always explicitly concerned the discrimination of the minority.

The Implementation of Learning Materials Based on Local Wisdom of Agricultural in Binjai to Improve the Students Problem Solving Abilities

2019 ◽  
Author(s):  
Nur Tsalits Fahman Mughni
Keyword(s):  
Problem Solving ◽  
Control Group ◽  
School Grade ◽  
Teaching Materials ◽  
Quasi Experimental ◽  
Equivalent Control ◽  
The Subject ◽  
And Control ◽  
Experimental Group

Teaching materials by integrating local culture makes easier for students to understand the subject matter in the learning process. The aims of the study is to measure the effectiveness of teaching materials based on local wisdom of agriculture in Binjai in improving the students problem solving abilities. The research method was a quasi experimental which use non equivalent control group in the pretest posttest design. The sample of study were students of Senior High School grade X in Binjai that consisted of experiment group which used teaching materials based on local wisdom of agriculture in Binjai and control group that used student handbooks. Teaching materials are tested by material experts and technology experts to ensure the quality of teaching materials. Data collection was conducted through test. The results showed that the teaching materials based on local wisdom of agriculture in Binjai effective in improving students problem solving abilities in the experimental group students based on the results of N gain value was 0.67 which has medium criteria. It means teaching materials based on agricultural local wisdom of agriculture in Binjai can be used as one of the teaching materials in learning activities.

UPAYA MENINGKATKAN KOMPETENSI GURU DALAM MENYUSUN RENCANA PELAKSANAAN PEMBELAJARAN MELALUI BIMBINGAN BERKELANJUTAN DI SD NEGERI 017 KUNTO DARUSSALAM TAHUN 2017

2020 ◽  
Author(s):  
Sri Winarsih
Keyword(s):  
Learning Strategies ◽  
Learning Process ◽  
School Principal ◽  
Initial Condition ◽  
Research Subjects ◽  
Analysis Techniques ◽  
Pedagogical Competence ◽  
Treatment Data ◽  
The Subject

This study aims to determine the appropriate steps in carrying out academic supervision so as to be able to improve the pedagogical competence of teachers, especially in the learning process which in turn will affect the improvement of the quality of education.The study was conducted in two cycles. Each cycle has different planning, implementation, observation and reflection. Research subjects of the principal and teacher. The school principal with his academic supervision measures, while the Kunto Darussalam Elementary School 017 teacher as an object as well as the subject in providing academic supervision treatment. Data collection techniques through class supervision with stages of supervising teachers in the learning process and observation of classroom learning, to record important events related to research, especially at the time of the processlearning takes place.Data analysis techniques that guide data processing using a percentage (%) of achievement with 100 constants. And to see the interpertation using score interpertation criteria to strengthen the interpretation in conclusions as follows: 80% - 100% (Very Good), 66% - 79 % (Good), 56% - 65% (Enough), and 40% - 55% (Less).The results showed that the ability of teachers in the implementation of the learning process experienced an increase in the percentage at each stage, from the first cycle reached an average of 63% (sufficient) and in the second cycle reached an average of 68% (good). There is an increase in teacher's ability by 5% from cycle I. In detail there is a significant increase in the initial condition of the school when compared to the final condition in the second cycle. The accuracy of teachers entering the class increased by 48%, the use of learning media increased by 32%, varied methods increased by 31%, and learning strategies increased by 36%.

An Ayurvedic Visual Rehabilitation In Lebers Congenital Amaurosis - Prospective Case Study

2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Dr. Vidhyasri M ◽  
Dr. S. M. Pasha
Keyword(s):  
Marked Improvement ◽  
Clinical Case ◽  
Treatment Plan ◽  
Visual Disability ◽  
Visual Rehabilitation ◽  
Potential Risks ◽  
The Subject ◽  
Slow Frequency

Introduction: This is the case report of child who was diagnosed with LCA reported with complaints of large-amplitude, slow-frequency, roving nystagmus, frequent tendency to press on his eyes, enopthalmos, with completely normal ophthalmoscopic examination with normal appearing optic nerve and retina and has a non recordable ERG; considering this condition under the lines of Vataja Nanatmaja Vyadhi treatment was structured to render effective visual rehabilitation which showed marked results. Methods: 4 years old male child who was diagnosed with lebers congenital amaurosis was brought by his parents to Eye OPD, GAMC, Bengaluru. The presentation of this case includes bibliographic review of the subject, presentation of a clinical case and description of the importance of Ayurvedic prespective of handling of these patients. Results: The child showed improvement in fixing for light and also nystagmus showed marked improvement and there were considerable behavioural changes observed. Discussion: It is important to deepen the environment of the disease to know the possible implications in Ayurvedic management, recognize the magnitude of visual disability that our patient presents for the establishment of the treatment plan and provide an integral care of excellence in an interdisciplinary way in favor of visual rehabilitation of our patients and also help to restore quality of life with no potential risks of side effects.

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