scholarly journals MODERN METHODS OF GEAR MILLING OF HARDENED LARGE-MODULE GEARS

10.23856/4340 ◽  
2021 ◽  
Vol 43 (6) ◽  
pp. 312-323
Author(s):  
Kateryna Kamchatna-Stepanova ◽  
Oleksandr Klochko
Keyword(s):  
High Speed ◽  
Technical Problem ◽  
High Hardness ◽  
Labor Costs ◽  
Gear Grinding ◽  
Modern Methods ◽  
Low Performance ◽  
Grinding Operations ◽  
Technological Methods

The latest developments of modern methods of high-speed gear milling of large-module cylindrical gears, both for preliminary grinding of teeth and for final blade processing of gears, are considered. For high-speed blade gear processing, promising designs of worm carbide cutters have been developed, manufactured and implemented. The technological regulations of blade gear processing for the operation of each of the design solutions of worm carbide cutters have been developed. The design of a special double-body worm cutter for double-sided cutting has been developed. It is shown that the carbide cutting elements of the milling cutters, which are placed only along the lines of the machine engagement of the tool and the workpiece, make it more economical compared to the known designs of similar tools. The application of the developed technological methods of pre-blade processing of the teeth of hardened wheels with carbide cutters reduces the labor intensity of low-performance gear grinding operations, depending on the wheel module, by 3-4 times by reducing the allowance from 1.5–2.5 mm on the tooth side to 0.3–0.5 mm, and also allows you to ensure the gear processing process is economical by reducing the consumption of carbide plates. The developed technological studies of ensuring the quality of gear processing of large-module cylindrical wheels allow us to solve the scientific and technical problem associated with the production of large-module gears with high-hardness teeth while improving the quality of their manufacture, reducing labor costs and reducing material consumption.

Pembuatan Pilot Project Pengolahan Air Limbah Industri Rambut Palsu dengan Sistem Lumpur Aktif

2016 ◽  
Vol 8 (15) ◽  
pp. 37-47
Author(s):  
Sri Moertinah ◽  
Misbachul Moenir
Keyword(s):  
Activated Sludge ◽  
Biological Treatment ◽  
Operating Cost ◽  
Pilot Project ◽  
Labor Costs ◽  
Industrial Waste Water ◽  
Microbial Adaptation ◽  
Central Java ◽  
Electricity Costs

This study aims to create a pilot project for wastewater treatment wig industry with biological activated sludge technology to applied in the industry. Design criteria for the pilot project are the influent COD ≤ 900 mg/l, MLSS = 3,000 mg/l, 30-hours residence time. DO ≥ 2 mg/l and flow 10 m3/day. Implementation of a pilot project initiated by seeding aerobic microbes and microbial adaptation to proceed with wastewater to be treated. The trial results showed that the pilot project % COD reduction ranged from 73.2% - 91% and the result is not much different from the results of laboratory-scale research about 89.7% and the quality  of the effluent is already fullfill the standard of industrial waste water wig required by the Central Java Provincial Regulation No. 5 of 2012. The calculation of operating cost of activated sludge biological treatment which includes labor costs, electricity costs, equipment maintenance costs, expenses and other nutrients obtained the price of  Rp. 2972/m3 or Rp. 742.99/wig.ABSTRAKPenelitian ini bertujuan untuk membuat pilot project pengolahan air limbah industri rambut palsu dengan sistem lumpur aktif yang diterapkan di industri. Kriteria desain pilot project tersebut adalah COD influen ≤ 900 mg/l, MLSS = 3.000 mg/l, waktu tinggal 30 jam DO≥2 mg/l  dan debit air limbah 10 m3/hari. Pelaksanaan pilot project dimulai dengan seeding mikroba aerob dan dilanjutkan dengan adaptasi mikroba dengan air limbah yang akan diolah. Hasil uji coba pilot project menunjukkan bahwa % penurunan COD berkisar antara 73,2% - 91% dan hasil ini tidak berbeda jauh dengan hasil penelitian skala laboratorium sekitar 89,7% dan kualitas air limbah hasil pengolahan sudah memenuhi baku mutu air limbah industri rambut palsu yang dipersyaratkan oleh Peraturan Daerah Provinsi Jawa Tengah No 5 tahun 2012. Dari hasil perhitungan biaya operasional pengolahan biologis lumpur aktif yang meliputi biaya tenaga kerja, biaya listrik, biaya perawatan peralatan, biaya nutrien dan lainnya diperoleh harga sebesar Rp. 2972/m3  atau Rp. 742,99/wig.   Kata kunci : air limbah industri rambut palsu, pilot project, sistem lumpur aktif

CPM REX 25

Alloy Digest ◽  
1980 ◽  
Vol 29 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
High Speed ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
High Speeds ◽  
Aisi Type ◽  
Tool Performance ◽  
End Mills ◽  
Machining Operations

Abstract CPM REX 25 is a super high-speed steel made without cobalt. It is comparable to AISI Type T15 cobalt-containing high-speed steel in response to heat treatment, properties, and tool performance. CPM REX 25 is recommended for machining operations requiring heavy cuts, high speeds and feeds, and difficult-to-machine materials of high hardness and abrasion resistance. Typical applications are boring tools, drills, gear cutters, punches, form tools, end mills and broaches. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-365. Producer or source: Crucible Materials Corporation.

TATMO V-N

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
High Speed ◽  
Cutting Tool ◽  
High Speed Steel ◽  
High Hardness ◽  
Heat Treating ◽  
Nitrogen Addition ◽  
Aisi Type ◽  
End Mills ◽  
Red Hardness ◽  
Edge Toughness

Abstract TATMO V-N is an AISI Type M7 high-speed steel modified by alloy balancing and a nitrogen addition to develop superior hardness response in heat treatment. It is an excellent grade for many cutting-tool applications requiring an optimum balance of red hardness, edge toughness and wear resistance, such as drills, taps, end mills, reamers and milling cutters. Its combination of outstanding properties and high hardness makes Tatmo V-N a logical alternate for cobalt high-speed steels in many cutting-tool applications. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-452. Producer or source: Latrobe Steel Company.

Research on High-Speed Cutting of Cr12MoV Hardened Steel - A Review

2020 ◽  
Vol 15 ◽  
Author(s):  
Fei Sun ◽  
Guohe Li ◽  
Qi Zhang ◽  
Meng Liu
Keyword(s):  
High Speed ◽  
Cutting Temperature ◽  
High Hardness ◽  
High Strength ◽  
Hardened Steel ◽  
Parameters Optimization ◽  
Future Research ◽  
High Speed Machining ◽  
Machined Surface ◽  
Stamping Die

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.

Resilient Factors in Students with Disabilities

2018 ◽  
Vol 5 (2) ◽  
pp. 23 ◽  
Author(s):  
Gustavo Rafael Escobar Delgado ◽  
Anicia Katherine Tarazona Meza ◽  
Andy Einstein García García
Keyword(s):  
Academic Performance ◽  
Students With Disabilities ◽  
Latin American ◽  
Descriptive Study ◽  
The Other ◽  
Disabled Students ◽  
Low Performance ◽  
The Relationship ◽  
Latin American Population

The research analyzes the relationship between factors of resilience and academic performance in disabled students studying at the Technical University of Manabí. It is a correlational descriptive study conducted with a population of 88 disabled students, of which two groups were selected, one with high academic performance and the other with low performance. A questionnaire was designed and applied to determine the level of quality of life and risk factors of adolescents. Resilience was measured with the SV-RES scale created for the Latin American population.

scholarly journals Not all biases are bad: equitable and inequitable biases in machine learning and radiology

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mirjam Pot ◽  
Nathalie Kieusseyan ◽  
Barbara Prainsack
Keyword(s):  
Machine Learning ◽  
Human Error ◽  
Technical Problem ◽  
Social Dimension ◽  
Patient Treatment ◽  
Technical Solution ◽  
Negative Effects ◽  
Different Types ◽  
Human Decision

AbstractThe application of machine learning (ML) technologies in medicine generally but also in radiology more specifically is hoped to improve clinical processes and the provision of healthcare. A central motivation in this regard is to advance patient treatment by reducing human error and increasing the accuracy of prognosis, diagnosis and therapy decisions. There is, however, also increasing awareness about bias in ML technologies and its potentially harmful consequences. Biases refer to systematic distortions of datasets, algorithms, or human decision making. These systematic distortions are understood to have negative effects on the quality of an outcome in terms of accuracy, fairness, or transparency. But biases are not only a technical problem that requires a technical solution. Because they often also have a social dimension, the ‘distorted’ outcomes they yield often have implications for equity. This paper assesses different types of biases that can emerge within applications of ML in radiology, and discusses in what cases such biases are problematic. Drawing upon theories of equity in healthcare, we argue that while some biases are harmful and should be acted upon, others might be unproblematic and even desirable—exactly because they can contribute to overcome inequities.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

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