scholarly journals Prediction Methods and Experimental Techniques for Chatter Avoidance in Turning Systems: A Review

2019 ◽  
Vol 9 (21) ◽  
pp. 4718 ◽  
Author(s):  
Gorka Urbikain ◽  
Daniel Olvera ◽  
Luis Norberto López de Lacalle ◽  
Aitor Beranoagirre ◽  
Alex Elías-Zuñiga
Keyword(s):  
Scientific Literature ◽  
General Trend ◽  
Stability Prediction ◽  
Chatter Detection ◽  
Machining Processes ◽  
Current State ◽  
Chatter Vibrations ◽  
State Of Research ◽  
And Control ◽  
Chip Volume

The general trend towards lightweight components and stronger but difficult to machine materials leads to a higher probability of vibrations in machining systems. Amongst them, chatter vibrations are an old enemy for machinists with the most dramatic cases resulting in machine-tool failure, accelerated tool wear and tool breakage or part rejection due to unacceptable surface finish. To avoid vibrations, process designers tend to command conservative parameters limiting productivity. Among the different machining processes, turning is responsible of a great amount of the chip volume removed worldwide. This paper reports some of the main efforts from the scientific literature to predict stability and to avoid chatter with special emphasis on turning systems. There are different techniques and approaches to reduce and to avoid chatter effects. The objective of the paper is to summarize the current state of research in this hot topic, particularly (1) the mechanistic, analytical, and numerical methods for stability prediction in turning; (2) the available techniques for chatter detection and control; (3) the main active and passive techniques.

scholarly journals The complexity of the gene and the precision of CRISPR

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Esha Shah ◽  
David Ludwig ◽  
Phil Macnaghten
Keyword(s):  
Gene Editing ◽  
Genetically Modified Organisms ◽  
Scientific Literature ◽  
Rapid Development ◽  
Public Support ◽  
Unintended Consequences ◽  
Current State ◽  
Technological Control ◽  
The Status ◽  
State Of Research

The rapid development of CRISPR-based gene editing has been accompanied by a polarized governance debate about the status of CRISPR-edited crops as genetically modified organisms. This article argues that the polarization around the governance of gene editing partly reflects a failure of public engagement with the current state of research in genomics and postgenomics. CRISPR-based gene-editing technology has become embedded in a narrow narrative about the ease and precision of the technique that presents the gene as a stable object under technological control. By tracing the considerably destabilized scientific understanding of the gene in genomics and postgenomics, this article highlights that this publicly mediated ontology strategically avoids positioning the “ease of CRISPR-based editing” in the wider context of the “complexity of the gene.” While this strategic narrowness of CRISPR narratives aims to create public support for gene-editing technologies, we argue that it stands in the way of socially desirable anticipatory governance and open public dialogue about societal promises and the unintended consequences of gene editing. In addressing the polarization surrounding CRISPR-based editing technology, the article emphasizes the need for engagement with the complex state of postgenomic science that avoids strategic simplifications of the scientific literature in promoting or opposing the commercial use of the gene-editing technology.

Dynamics and Control of a Portable DMFC System

2009 ◽  
Author(s):  
Federico Zenith ◽  
Ulrike Krewer
Keyword(s):  
Environmental Conditions ◽  
Direct Methanol Fuel Cells ◽  
Control Analysis ◽  
Control Loops ◽  
Current State ◽  
Current Implementation ◽  
Direct Methanol ◽  
Dynamics And Control ◽  
State Of Research ◽  
And Control

The current state of research on direct methanol fuel cells focuses heavily on the cell itself, with only a small minority of published articles about the management of the complete DMFC system. It is of particular importance to learn about the dynamics and control of such systems in order to provide autonomous and robust operation in spite of changing environmental conditions. We simulate and analyse a reference DMFC system consisting of, besides a model of the fuel cell, a mixer, coolers, separators, pumps and a fuel tank. A control analysis of a DMFC system is presented, to understand which variables are to be controlled by what means, and what constraints the system sets on the control loops. Some apparently negative phenomena can be beneficial to control performance: methanol cross-over stabilises the concentration dynamics and allows the usage of simple feedforward controllers. A portable DMFC system may be used in various environments, with very different environmental conditions. It is therefore explored how these conditions influence the system’s operation and control strategy, especially in regard to environmental temperature and humidity. The current implementation of the model has been designed to study the long-term transients, such as overall anode-loop water and energy holdups, assuming pseudo-steady state for most units.

Factors to Consider in Research on Prevention of Relapse in Cigarette Smoking

1987 ◽  
Vol 60 (3) ◽  
pp. 967-974 ◽  
Author(s):  
David W. Hall
Keyword(s):  
Cigarette Smoking ◽  
Group Treatment ◽  
Significant Others ◽  
Current State ◽  
Number Of Factors ◽  
State Of Research ◽  
And Control ◽  
Prevention Of Relapse

The current state of research on prevention of relapse in cigarette smoking is reviewed and a number of factors relevant to research on such prevention discussed. Issues related to timing of the program, criterion for inclusion in the program, individual vs group treatment, and control of the influences of smoking by significant others are discussed.

Current State of Research on Bio-Source Composite

2016 ◽  
Vol 822 ◽  
pp. 381-388
Author(s):  
Alin Ilie Haloiu ◽  
Stefan Tabacu
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Scientific Literature ◽  
Reinforced Polymers ◽  
Flax Fibers ◽  
Current State ◽  
State Of Research

This paper is a review of the current research on bio-source composite and especially flax fibers reinforced polymers. Fabrication methods and fiber treatments are presented.The mechanical properties found in the scientific literature are discussed.Experimental results from traction tests are presented for a bio-source composite: epoxy resin reinforced with flax fibers.

Culturally Responsive Pedagogy in Mathematics

2020 ◽  
Vol 2 ◽  
pp. 145-158
Author(s):  
Kenta Nagasawa
Keyword(s):  
Professional Development ◽  
Teacher Education ◽  
Culturally Responsive ◽  
Latino Students ◽  
Culturally Responsive Pedagogy ◽  
Mathematics Teacher Education ◽  
Development Program ◽  
Current State ◽  
Responsive Pedagogy ◽  
State Of Research

Purpose: This paper is a thematic literature review to examine the current state of research about Culturally Responsive Pedagogy in mathematics. The main themes are students’ perception, teacher education for pre-service teacher and professional development for teachers. Research methods/ approach: Literature was collected from Eric, which is a research engine of the education field. Also, Google Scholar is used to find articles of major scholars introduced by Dr. Rich Milner, who is the instructor of this course. Findings: Students faced microaggressions in mathematics class, which discouraged them to learn mathematics. The effect of teacher education was inconsistent in terms of the awareness of culturally responsive pedagogy and lesson plans. Research of professional development mentioned that mathematics was cultural. Implications for research and practice: It is more interesting to conduct long term or follow-up research to find the teacher’s practice after a taking professional development program. Also, it is critical to expand research scope besides African American and Latino students. Finally, evidence-based research is needed to change the political situation. Keywords: culturally responsive teaching, mathematics, teacher education, professional development, student’s perception

Editorial

2013 ◽  
Vol 1 (2) ◽  
pp. 1-3
Author(s):  
João José Pinto Ferreira ◽  
Anne-Laure Mention ◽  
Marko Torkkeli
Keyword(s):  
Economic Development ◽  
Education Research ◽  
Research And Development ◽  
Research Integrity ◽  
Academic Community ◽  
Human Knowledge ◽  
Academic Institutions ◽  
Current State ◽  
State Of Research ◽  
Successive Generations

The expansion of human knowledge in all areas is largely the outcome of the activity of academic institutions and the result of their mission to contribute to the cultural, intellectual and economic development of the society, involving education, research and university extension activities. For many years, the academic community has been organizing itself in all different ways to respond to current and future needs, ensuring research integrity and recognition, and building on successive generations of peers to validate and support the launching and development of novel research streams. We owe the current state of research and development of our society to generations of scholars and scientists that have brought all of us here.(...)

ORGANOPHOSPHORUS NEUROTOXINS

2020 ◽  
Author(s):  
Mariya Andriyanova ◽  
Aslanli Aslanli ◽  
Nataliya Basova ◽  
Viktor Bykov ◽  
Sergey Varfolomeev ◽  
...  
Keyword(s):  
Crop Protection ◽  
Chemical Warfare Agents ◽  
Agricultural Crop ◽  
Current State ◽  
Physicochemical Biology ◽  
Chemical Agents ◽  
Warfare Agents ◽  
History Of ◽  
Physicochemical Methods ◽  
State Of Research

The collective monograph is devoted to discussing the history of creation, studying the properties, neutralizing and using organophosphorus neurotoxins, which include chemical warfare agents, agricultural crop protection chemical agents (herbicides and insecticides) and medicines. The monograph summarizes the results of current scientific research and new prospects for the development of this field of knowledge in the 21st century, including the use of modern physicochemical methods for experimental study and theoretical analysis of biocatalysis and its mechanisms based on molecular modeling with supercomputer power. The book is intended for specialists who are interested in the current state of research in the field of organophosphorus neurotoxins. The monograph will be useful for students, graduate students, researchers specializing in the field of physical chemistry, physicochemical biology, chemical enzymology, toxicology, biochemistry, molecular biology and genetics, biotechnology, nanotechnology and biomedicine.

DEVELOPMENT OF COMPUTERIZED MONITORING AND CONTROL SYSTEM OF THE MOBILE ROBOT’S POSITIONING ON LARGE FERROMAGNETIC SURFACES BASED ON INTELLIGENT TECHNIQUES. COMPLEX OF TASKS OF MONITORING AND AUTOMATIC CONTROL OF MOBILE

2019 ◽  
pp. 37-47
Author(s):  
Yao Yueqin ◽  
Oleksiy Kozlov ◽  
Oleksandr Gerasin ◽  
Galyna Kondratenko
Keyword(s):  
Automatic Control ◽  
Point Of View ◽  
Monitoring And Control ◽  
Large Area ◽  
Monitoring And Control System ◽  
Technical Parameters ◽  
Automatic Control Systems ◽  
Current State ◽  
Computerized Monitoring ◽  
And Control

Analysis and formalization of the monitoring and automatic control tasks of the MR for the movement and execution of various types of technological operations on inclined and vertical ferromagnetic surfaces are obtained. Generalized structure of mobile robotic complex is shown with main subsystems consideration. Critical analysis of the current state of the problem of development of universal structures of mobile robots (MRs) for the various types of technological operations execution and elaborations of computerized systems for monitoring and control of MR movement is done. In particular, wheeled, walked and crawler type MRs with pneumatic, vacuum-propeller, magnetic and magnetically operated clamping devices to grip with vertical and ceiling surfaces are reviewed. The constructive features of the crawler MR with magnetic clamping devices capable of moving along sloping ferromagnetic surfaces are considered. The basic technical parameters of the MR are shown for the further synthesis of computerized monitoring and automatic control systems. Formalization of the tasks of monitoring and control of the MR positioning at the processing of large area ferromagnetic surfaces is considered from the point of view of control theory.

Short Review and opinion: New matter properties and applications based on Hybrids Graphene based Metamaterials

2020 ◽  
Vol 04 ◽  
Author(s):  
A. Guillermo Bracamonte
Keyword(s):  
Short Review ◽  
New Materials ◽  
Design And Synthesis ◽  
Chemical Structures ◽  
Current State ◽  
Potential Applications ◽  
Fundamental Research ◽  
Miniaturized Instrumentation ◽  
And Control ◽  
Conductive Properties

: Graphene as Organic material showed special attention due to their electronic and conductive properties. Moreover, its highly conjugated chemical structures and relative easy modification permitted varied design and control of targeted properties and applications. In addition, this Nanomaterial accompanied with pseudo Electromagnetic fields permitted photonics, electronics and Quantum interactions with their surrounding that generated new materials properties. In this context, this short Review, intends to discuss many of these studies related with new materials based on graphene for light and electronic interactions, conductions, and new modes of non-classical light generation. It should be highlighted that these new materials and metamaterials are currently in progress. For this reason it was showed and discussed some representative examples from Fundamental Research with Potential Applications as well as for their incorporations to real Advanced devices and miniaturized instrumentation. In this way, it was proposed this Special issue entitled “Design and synthesis of Hybrids Graphene based Metamaterials”, in order to open and share the knowledge of the Current State of the Art in this Multidisciplinary field.

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