scholarly journals Modeling and Research of Resistance Characteristics of an Interlocking Side Milling Cutter with a Constructive Radial Feed When Processing Extended RK-profile Shafts

2020 ◽  
Vol 24 (1) ◽  
pp. 23-34
Author(s):  
V. V. Kuts ◽  
V. V. Ponomaryov

Purpose of research. The study is devoted to improving the resistance characteristics of an interlocking side milling cutter with a constructive radial feed when processing extended RK profile shafts while maintaining the required quality of surface treatment.Methods. Forming of RK profiles by milling with a disk cutter with a constructive radial feed allows you to obtain the required surface quality with high processing productivity. Due to the fact that the processing conditions for each cutting insert are different, it is necessary to study the resistance of interchangeable polyhedral inserts (IPI) and to search for structural solutions to reduce the range of change in resistance, while maintaining the quality of surface treatment of the PK profile. The influence of the use of an uneven pitch of location both on the quality of processing and on the resistance of each individual insert is studied.Results. The paper presents a method for calculating the resistance of an IPI of a interlocking side milling cutter during processing of an extended RK profile of a shaft, taking into account the individual conditions of their operation, namely: cutting speed, feed to the tooth, milling width and the diametrical position of the IPIConclusion. The analysis of the influence of the structural parameters of the cutter on changing the range of values of the resistance of IPI is made, and recommendations for its reduction are proposed. The main design parameters that affect the change in the resistance range are also identified.

2012 ◽  
Vol 523-524 ◽  
pp. 64-69
Author(s):  
Yoshio Mizugaki ◽  
Kazuki Takafuji ◽  
Koichi Kikkawa ◽  
Teppei Kuroda ◽  
Taro Kimura

This paper presents the experimental results of cutting performance and tool wear of a milling cutter in dry side milling of aluminum alloy A2017. The milling cutter consists of Co-bonded High-Speed-Steel matrix with Diamond-Like-Carbon coating (abbrev. DLC-coated HSS-Co cutter). The machining experiments were carried out under cutting speed of 63 to 189 [m•min-1] and feed of 0.08 [mm/tooth/rev], and the criterion of tool life was the generation of gauge and/or scratch on a machined surface. The experimental results support that the DLC-coated cutter in up cutting has good performance among four types of combination by the presence or absence of coating and the up/down cutting manner. They also showed that the tool life of DLC-coated cutter in up cutting under cutting speed of 157 [m•min-1] was corresponding to the cutting distance of 80 [m] with average width of flank wear 102 [μm] and that in down cutting was 60 [m] with 85 [μm]. In the range of cutting distance up to 100 [m], the resultant cutting force with the DLC-coated cutter was smaller than that with a non-coating cutter. In case of the DLC-coated cutter in up cutting under the cutting speed of 189 [m•min-1], a chatter vibration occurred during the initial cutting distance. In case of the radial depth of cut of 1.5 [mm], it lasted up to the cutting distance of 10 [m] and more.


Author(s):  
Sinan Kesriklioglu ◽  
Frank E. Pfefferkorn

Abstract The goal of this work is to predict the tool-chip interface temperature during cryogenic machining and determine the effectiveness of this cooling strategy. Knowledge of the tool-chip interface temperature is needed to conduct process planning: choosing a tool cooling geometry, cutting speed, and cryogen flow rate as well as predicting tool life and achievable material removal rate. A detailed explanation of the analytical heat transfer model is presented, which is a modified form of Loewen and Shaw's orthogonal cutting model, where a thermal resistance network is applied to represent the heat transfer mechanisms in, and out of, the cutting tool. An in-depth discussion of the temperature rise at the tool-chip interface during orthogonal machining of titanium alloy Ti–6Al–4V is presented. The effect of cutting speed, cryogen flow rate and quality, and cooling strategy are explored. The model is used to compare the effect of internal cryogenic cooling with external flood cooling using a water-based metalworking fluid or liquid nitrogen. A sensitivity analysis of the model is conducted and ranks the relative importance of various design parameters. The thermal conductivity of the cutting insert has the greatest influence on the predicted interface temperature. The low boiling temperature and phase change are what make internal cooling of a cutting insert with liquid nitrogen effective at reducing the tool-chip interface temperature. If the heat flowing into the tool, from the tool-chip interface, does not exceed the available latent heat in the cryogen, then this method is more effective than external flood cooling.


The method of high-speed milling has many advantages than conventional milling. Very often, high-speed milling is considered simply a way to increase productivity due to a higher cutting speed than commonly used. It is rarely emphasized that quality of the product can be improved by improving accuracy and improving the surface quality of the cutter.


Author(s):  
B. Carragher ◽  
M. Whittaker

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.


2010 ◽  
Vol 39 (2) ◽  
pp. 34-36
Author(s):  
Vaia Touna

This paper argues that the rise of what is commonly termed "personal religion" during the Classic-Hellenistic period is not the result of an inner need or even quality of the self, as often argued by those who see in ancient Greece foreshadowing of Christianity, but rather was the result of social, economic, and political conditions that made it possible for Hellenistic Greeks to redefine the perception of the individual and its relationship to others.


2017 ◽  
Vol 3 (1) ◽  
pp. 112-126 ◽  
Author(s):  
Ilaria Cristofaro

From a phenomenological perspective, the reflective quality of water has a visually dramatic impact, especially when combined with the light of celestial phenomena. However, the possible presence of water as a means for reflecting the sky is often undervalued when interpreting archaeoastronomical sites. From artificial water spaces, such as ditches, huacas and wells to natural ones such as rivers, lakes and puddles, water spaces add a layer of interacting reflections to landscapes. In the cosmological understanding of skyscapes and waterscapes, a cross-cultural metaphorical association between water spaces and the underworld is often revealed. In this research, water-skyscapes are explored through the practice of auto-ethnography and reflexive phenomenology. The mirroring of the sky in water opens up themes such as the continuity, delimitation and manipulation of sky phenomena on land: water spaces act as a continuation of the sky on earth; depending on water spaces’ spatial extension, selected celestial phenomena can be periodically reflected within architectures, so as to make the heavenly dimension easily accessible and a possible object of manipulation. Water-skyscapes appear as specular worlds, where water spaces are assumed to be doorways to the inner reality of the unconscious. The fluid properties of water have the visual effect of dissipating borders, of merging shapes, and, therefore, of dissolving identities; in the inner landscape, this process may represent symbolic death experiences and rituals of initiation, where the annihilation of the individual allows the creative process of a new life cycle. These contextually generalisable results aim to inspire new perspectives on sky-and-water related case studies and give value to the practice of reflexive phenomenology as crucial method of research.


2020 ◽  
Author(s):  
Emmanuel Kiiza Mwesiga ◽  
Noeline Nakasujja ◽  
Lawrence Nankaba ◽  
Juliet Nakku ◽  
Seggane Musisi

Introduction: Individual and group level interventions have the largest effect on outcomes in patients with the first episode of psychosis. The quality of these individual and group level interventions provided to first-episode psychosis patients in Uganda is unclear.Methods: The study was performed at Butabika National Psychiatric Teaching and referral hospital in Uganda. A retrospective chart review of recently discharged adult in-patients with the first episode of psychosis was first performed to determine the proportion of participants who received the different essential components for individual and group level interventions. From the different proportions, the quality of the services across the individual and group interventions was determined using the first-Episode Psychosis Services Fidelity Scale (FEPS-FS). The FEPS-FS assigns a grade of 1-5 on a Likert scale depending on the proportion of patients received the different components of the intervention. Results: The final sample included 156 first-episode psychosis patients. The median age was 27 years [IOR (24-36)] with 55% of participants of the female gender. 13 essential components across the individual and group interventions were assessed and their quality quantified. All 13 essential components had poor quality with the range of scores on the FEPS-FS of 1-3. Only one essential component assessed (use of single antipsychotics) had moderate quality.Discussion: Among current services at the National psychiatric hospital of Uganda, the essential for individual and group level interventions for psychotic disorders are of low quality. Further studies are required on how the quality of these interventions can be improved.


2020 ◽  
Vol 1 (10(79)) ◽  
pp. 12-18
Author(s):  
G. Bubyreva

The existing legislation determines the education as "an integral and focused process of teaching and upbringing, which represents a socially important value and shall be implemented so as to meet the interests of the individual, the family, the society and the state". However, even in this part, the meaning of the notion ‘socially significant benefit is not specified and allows for a wide range of interpretation [2]. Yet the more inconcrete is the answer to the question – "who and how should determine the interests of the individual, the family and even the state?" The national doctrine of education in the Russian Federation, which determined the goals of teaching and upbringing, the ways to attain them by means of the state policy regulating the field of education, the target achievements of the development of the educational system for the period up to 2025, approved by the Decree of the Government of the Russian Federation of October 4, 2000 #751, was abrogated by the Decree of the Government of the Russian Federation of March 29, 2014 #245 [7]. The new doctrine has not been developed so far. The RAE Academician A.B. Khutorsky believes that the absence of the national doctrine of education presents a threat to national security and a violation of the right of citizens to quality education. Accordingly, the teacher has to solve the problem of achieving the harmony of interests of the individual, the family, the society and the government on their own, which, however, judging by the officially published results, is the task that exceeds the abilities of the participants of the educational process.  The particular concern about the results of the patriotic upbringing served as a basis for the legislative initiative of the RF President V. V. Putin, who introduced the project of an amendment to the Law of RF "About Education of the Russian Federation" to the State Duma in 2020, regarding the quality of patriotic upbringing [3]. Patriotism, considered by the President of RF V. V. Putin as the only possible idea to unite the nation is "THE FEELING OF LOVE OF THE MOTHERLAND" and the readiness for every sacrifice and heroic deed for the sake of the interests of your Motherland. However, the practicing educators experience shortfalls in efficient methodologies of patriotic upbringing, which should let them bring up citizens, loving their Motherland more than themselves. The article is dedicated to solution to this problem based on the Value-sense paradigm of upbringing educational dynasty of the Kurbatovs [15].


2019 ◽  
Vol 1 (7) ◽  
pp. 10-13
Author(s):  
D. Yu. Ershov ◽  
I. N. Lukyanenko ◽  
E. E. Aman

The article shows the need to develop diagnostic methods for monitoring the quality of lubrication systems, which makes it possible to study the dynamic processes of contacting elements of the friction systems of instrument mechanisms, taking into account roughness parameters, the presence of local surface defects of elements and the bearing capacity of a lubricant. In the present article, a modern diagnostic model has been developed to control the quality of the processes of production and operation of friction systems of instrument assemblies. With the help of the developed model, it becomes possible to establish the relationship of diagnostic and design parameters of the mechanical system, as well as the appearance of possible local defects and lubricant state, which characterize the quality of friction systems used in many mechanical assemblies of the mechanisms of devices. The research results are shown in the form of nomograms to assess the defects of the elements of friction mechanisms of the mechanisms of the devices.


AI Magazine ◽  
2012 ◽  
Vol 34 (1) ◽  
pp. 10 ◽  
Author(s):  
Steve Kelling ◽  
Jeff Gerbracht ◽  
Daniel Fink ◽  
Carl Lagoze ◽  
Weng-Keen Wong ◽  
...  

In this paper we describe eBird, a citizen-science project that takes advantage of the human observational capacity to identify birds to species, which is then used to accurately represent patterns of bird occurrences across broad spatial and temporal extents. eBird employs artificial intelligence techniques such as machine learning to improve data quality by taking advantage of the synergies between human computation and mechanical computation. We call this a Human-Computer Learning Network, whose core is an active learning feedback loop between humans and machines that dramatically improves the quality of both, and thereby continually improves the effectiveness of the network as a whole. In this paper we explore how Human-Computer Learning Networks can leverage the contributions of a broad recruitment of human observers and processes their contributed data with Artificial Intelligence algorithms leading to a computational power that far exceeds the sum of the individual parts.


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