scholarly journals Impact of cutting face profile angle upon shear deformation degree

Author(s):  
Александр Ямников ◽  
Aleksandr Yamnikov ◽  
Дмитрий Волков ◽  
Dmitry Volkov

It is established that cutting with gear-cutting and thread-cutting tools is not free that results in the increase of loading upon tool tips and their quick wear. The layers of metal cut are subjected to considerable shear deformation and also to other kinds of deformation. In this connection the wear character of a tool and its properties will change. There is considered a process of chip removal by trapezoidal and triangular cutters (as in case of metal cutting off with teeth of a hob may be used not three but two tool tips) and the impact of a cutting face profile angle upon a shear deformation degree is also considered. There are shown analytical dependences for the definition of angles of a chip flow, a relative shear, a deformation degree of a shear and a value of tangential stresses in the cutting area taking into account the influence of the strength of material machined, width and thickness of a layer cut and a friction factor. The dependences are checked up at cutting with a trapezoidal cutter.

2021 ◽  
Vol 887 ◽  
pp. 383-388
Author(s):  
E.A. Petrovsky ◽  
K.A. Bashmur ◽  
Vadim S. Tynchenko

The present study describes the impact of cutting speed and various lubricant-cooling process agents on the temperature of alloy turning. The research was conducted for NiCr20TiAl and N07750 nickel alloys with the help of HG30 and HS123 carbide-tipped cutting tools. New lubricant-cooling process agents with nanodispersed diamond graphite additives are studied. The optimal composition of the diamond graphite additives is revealed when cutting these alloys. It is demonstrated on the basis of tests the positive effect of diamond graphite agents on the quantitative changes in measured cutting temperatures. In doing so, the cutting speed and the lubricant-cooling agents applied to the cutting zone have little impact on the nature of temperature patterns.


2006 ◽  
Vol 113 ◽  
pp. 559-564 ◽  
Author(s):  
Alexander S. Chaus ◽  
J. Chovanec ◽  
M. Legerská

As-cast high-speed steels heat-treated have completely much lower impact toughness than that of the steels of a similar chemical composition but undergone hot working – rolling or forging. That is attributed to the influence of eutectic carbides, which especially being coarse, provide easily brittle intergrain fracture sites under low stress intensity factor levels. This is especially real for cast cutting tools. In order to exhibit good all-round performance the impact toughness enhancement of as-cast high-speed steels is obligatorily needed. In this connection it is expedient to turn from high-speed steels of conventional ledeburitic origin to high-speed steels of hypereutectoid and ferritic-carbidic ones with considerably lower carbide heterogeneity resulting in enhanced impact toughness. In the present work special features of the structure, phase composition and properties of such high-speed steels designed for cast tool are studied. In order to substitute tungsten by chromium in as-cast high-speed steel a special alloying system has also been developed.


EDUKASI ◽  
2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Hendra Karianga

Sources of revenue and expenditure of APBD (regional budget) can be allocated to finance the compulsory affairs and optional affairs in the form of programs and activities related to the improvement of public services, job creation, poverty alleviation, improvement of environmental quality, and regional economic growth. The implications of these policies is the need for funds to finance the implementation of the functions, that have become regional authority, is also increasing. In practice, regional financial management still poses a complicated issue because the regional head are reluctant to release pro-people regional budget policy, even implication of regional autonomy is likely to give birth to little kings in region causing losses to state finance and most end up in legal proceedings. This paper discusses the loss of state finance and forms of liability for losses to the state finance. The result of the study can be concluded firstly,  there are still many differences in giving meaning and definition of the loss of state finace and no standard definition of state losses, can cause difficulties. The difficulty there is in an effort to determine the amount of the state finance losses. The calculation of state/regions losses that occur today is simply assessing the suitability of the size of the budget and expenditure without considering profits earned by the community and the impact of the use of budget to the community. Secondly, the liability for losses to the state finance is the fulfillment of the consequences for a person to give or to do something in the regional financial management by giving birth to three forms of liability, namely the Criminal liability, Civil liability, and Administrative liability.Keywords: state finance losses, liability, regional finance.


2017 ◽  
Vol 3 (2) ◽  
pp. 7
Author(s):  
Saida Parvin

Women’s empowerment has been at the centre of research focus for many decades. Extant literature examined the process, outcome and various challenges. Some claimed substantial success, while others contradicted with evidence of failure. But the success remains a matter of debate due to lack of empirical evidence of actual empowerment of women around the world. The current study aimed to address this gap by taking a case study method. The study critically evaluates 20 cases carefully sampled to include representatives from the entire country of Bangladesh. The study demonstrates popular beliefs about microfinance often misguide even the borrowers and they start living in a fabricated feeling of empowerment, facing real challenges to achieve true empowerment in their lives. The impact of this finding is twofold; firstly there is a theoretical contribution, where the definition of women’s empowerment is proposed to be revisited considering findings from these cases. And lastly, the policy makers at governmental and non-governmental organisations, and multinational donor agencies need to revise their assessment tools for funding.


2021 ◽  
pp. 101053952110260
Author(s):  
Mairead Connolly ◽  
Laura Phung ◽  
Elise Farrington ◽  
Michelle J. L. Scoullar ◽  
Alyce N. Wilson ◽  
...  

Preterm birth and stillbirth are important global perinatal health indicators. Definitions of these indicators can differ between countries, affecting comparability of preterm birth and stillbirth rates across countries. This study aimed to document national-level adherence to World Health Organization (WHO) definitions of preterm birth and stillbirth in the WHO Western Pacific region. A systematic search of government health websites and 4 electronic databases was conducted. Any official report or published study describing the national definition of preterm birth or stillbirth published between 2000 and 2020 was eligible for inclusion. A total of 58 data sources from 21 countries were identified. There was considerable variation in how preterm birth and stillbirth was defined across the region. The most frequently used lower gestational age threshold for viability of preterm birth was 28 weeks gestation (range 20-28 weeks), and stillbirth was most frequently classified from 20 weeks gestation (range 12-28 weeks). High-income countries more frequently used earlier gestational ages for preterm birth and stillbirth compared with low- to middle-income countries. The findings highlight the importance of clear, standardized, internationally comparable definitions for perinatal indicators. Further research is needed to determine the impact on regional preterm birth and stillbirth rates.


Author(s):  
Nadine T. Hillock ◽  
Tracy L. Merlin ◽  
Jonathan Karnon ◽  
John Turnidge ◽  
Jaklin Eliott

Abstract Background The frameworks used by Health Technology Assessment (HTA) agencies for value assessment of medicines aim to optimize healthcare resource allocation. However, they may not be effective at capturing the value of antimicrobial drugs. Objectives To analyze stakeholder perceptions regarding how antimicrobials are assessed for value for reimbursement purposes and how the Australian HTA framework accommodates the unique attributes of antimicrobials in cost-effectiveness evaluation. Methods Eighteen individuals representing the pharmaceutical industry or policy-makers were interviewed. Interviews were transcribed verbatim, coded, and thematically analyzed. Results Key emergent themes were that reimbursement decision-making should consider the antibiotic spectrum when assessing value, risk of shortages, the impact of procurement processes on low-priced comparators, and the need for methodological transparency when antimicrobials are incorporated into the economic evaluation of other treatments. Conclusions Participants agreed that the current HTA framework for antimicrobial value assessment is inadequate to properly inform funding decisions, as the contemporary definition of cost-effectiveness fails to explicitly incorporate the risk of future resistance. Policy-makers were uncertain about how to incorporate future resistance into economic evaluations without a systematic method to capture costs avoided due to good stewardship. Lacking financial reward for the benefits of narrower-spectrum antimicrobials, companies will likely focus on developing broad-spectrum agents with wider potential use. The perceived risks of shortages have influenced the funding of generic antimicrobials in Australia, with policy-makers suggesting a willingness to pay more for assured supply. Although antibiotics often underpin the effectiveness of other medicines, it is unclear how this is incorporated into economic models.


2020 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Orlando Durán ◽  
Javier Aguilar ◽  
Andrea Capaldo ◽  
Adolfo Arata

Resilience is an intrinsic characteristic of systems. Through it, the capacity of a system to react to the existence of disruptive events is expressed. A series of metrics to represent systems’ resilience have been proposed, however, only one indicator relates the availability of the system to this characteristic. With such a metric, it is possible to relate the topological aspects of a system and the resources available in order to be able to promptly respond to the loss of performance as a result of unexpected events. This work proposes the adaptation and application of such a resilience index to assess the influence of different maintenance strategies and topologies in fleets’ resilience. In addition, an application study considering an actual mining fleet is provided. A set of critical assets was identified and represented using reliability block diagrams. Monte Carlo simulation experiments were conducted and the system availability data were extracted. Resilience indexes were obtained in order to carry out the definition of the best maintenance policies in critical equipment and the assessment of the impact of modifying system redundancies. The main results of this work lead to the overall conclusion that redundancy is an important system attribute in order to improve resiliency along time.


2021 ◽  
Vol 129 ◽  
pp. 107941
Author(s):  
Erica Vassoney ◽  
Andrea Mammoliti Mochet ◽  
Maria Bozzo ◽  
Roberto Maddalena ◽  
Donatella Martinet ◽  
...  

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