Design, Characteristics and Performance of Diamond Pad Conditioners

2010 ◽  
Vol 1249 ◽  
Author(s):  
Douglas J. Pysher ◽  
Brian Goers ◽  
John Zabasajja

AbstractA wide range of diamond pad conditioner (disk) designs have been characterized and key performance metrics have been collected. Relationships between design characteristics including diamond size and shape, spatial density, and tip height distribution and polishing pad wear rates and pad surface textures have been established for a variety of pads.Estimation of the depth-of-penetration of working diamonds, from used disk analyses, allows meaningful topographic assessments of alternative conditioner designs and predictions of relative performance. An example of an improved conditioner that illustrates this design methodology is given.Conditioner aggressiveness and its decay in various slurries have been measured to assess disk lifetime in Chemical Mechanical Planarization (CMP) processes environments. Key factors affecting disk lifetime are discussed and an improved-lifetime conditioner for use in aggressive slurries will be reviewed.

2012 ◽  
Vol 69 (11) ◽  
pp. 1806-1816 ◽  
Author(s):  
Alessandro Lucchetti ◽  
Antonello Sala

An innovative approach with side-scan sonar was implemented to observe directly during towing operations the behaviour and the performance of hydraulic dredge, Rapido trawl, and two types of Mediterranean bottom trawls. The innovative aspect of the current paper is that a side-scan sonar was used alongside fishing operations when towing was in progress. Based on available literature, the type and level of the physical impact assessed were used to infer biological and ecological consequences caused by the fishing gear. The sonar used in real time can be applied to a wide range of research and management issues, such as the fishing gear impact on benthic ecosystems and the in situ fishing gear performance. We demonstrated that gear type and rigging, together with environmental conditions, are the main factors affecting the disturbance caused by fishing. Hydraulic dredges scrape the surface of the substratum and dig into it by resuspending large amounts of sediment. Rapido trawls used in muddy areas for common sole (Solea solea) dig deeper into the sediment, making furrows up to 10–13 cm deep. The most evident physical effects of trawling were the furrows produced by the otterboards, while other parts of the trawl created only faint marks.


Author(s):  
Yousef O. Sharrab ◽  
Mohammad Alsmirat ◽  
Bilal Hawashin ◽  
Nabil Sarhan

Advancement of the prediction models used in a variety of fields is a result of the contribution of machine learning approaches. Utilizing such modeling in feature engineering is exceptionally imperative and required. In this research, we show how to utilize machine learning to save time in research experiments, where we save more than five thousand hours of measuring the energy consumption of encoding recordings. Since measuring the energy consumption has got to be done by humans and since we require more than eleven thousand experiments to cover all the combinations of video sequences, video bit_rate, and video encoding settings, we utilize machine learning to model the energy consumption utilizing linear regression. VP8 codec has been offered by Google as an open video encoder in an effort to replace the popular MPEG-4 Part 10, known as H.264/AVC video encoder standard. This research model energy consumption and describes the major differences between H.264/AVC and VP8 encoders in terms of energy consumption and performance through experiments that are based on machine learning modeling. Twenty-nine raw video sequences are used, offering a wide range of resolutions and contents, with the frame sizes ranging from QCIF(176x144) to 2160p(3840x2160). For fairness in comparison analysis, we use seven settings in VP8 encoder and fifteen types of tuning in H.264/AVC. The settings cover various video qualities. The performance metrics include video qualities, encoding time, and encoding energy consumption.


2021 ◽  
Vol 71 (5) ◽  
pp. 1693-99
Author(s):  
Ahsan Malik ◽  
Faiza Kiran ◽  
Fareeha Farooq

Objective: To assess students’ perceptions of feedback, regarding its understanding, and practices in a traditional undergraduate dental curriculum in Pakistan, where feedback was not part of a formal curriculum as a structured entity. Study Design: Qualitative-phenomenology. Place and Duration of Study: Rawal Institute of Health Sciences, Islamabad from Dec 2017 to May 2018. Methodology: Purposive sampling was done, and data was gathered using semi-structured, group interview of 16 BDS students. Data was organized using qualitative software package Atlas.ti 8.0 and analyzed using thematic framework analysis. Results: Feedback, though, being practiced by faculty, was not identify as feedback by students. They did not appreciate it as an essential skillset for learning and performance. Though, conceptions of students regarding this phenomenon varied, five emergent themes displayed the essence of the phenomenon in this learning environment: 1) understanding ‘feedback’ through participants’ response, 2) highly variant experiences of information exchange, 3) modes and forms of feedback, 4) factors affecting feedback and 5) methods achieving learning progression. Conclusion: Our students were devoid of formally instituted feedback practices, so they were unable to identify it as ‘feedback’. Wide range of contradictory and many negative experiences of participants indicated that formal training in feedback and its systematic use might improve students’ experiences.Keywords: , , , , ,  .


Drones ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 43 ◽  
Author(s):  
Dhwanil Shukla ◽  
Narayanan Komerath

Aerodynamic interactions between rotors are important factors affecting the performance of in-plane multirotor Unmanned Air Vehicles (UAVs) or drones, which are the majority of small size UAVs (or mini-drones). Optimal design requires knowledge of the flow features. The low Reynolds number of many UAV rotors raises the question of how these features differ from those expected by traditional analytical methods for rotorcraft. Aerodynamics of a set of side-by-side rotors in hover over a range of rotor separation and Reynolds number is studied using high-speed Stereo Particle Image Velocimetry (SPIV) and performance measurements. The instantaneous and time-averaged SPIV data presented here indicate an increase in inter-rotor wake interactions with decrease in rotor spacing and Reynolds number. A dip in rotor efficiency at small rotor spacing at low Reynolds number is observed through thrust and torque measurements. The basic components of in-plane multirotor wake and velocity profiles are identified and discussed to help generalize the findings to a wide range of drones. However, the data provide confidence in traditional analysis tools, with small modifications.


2020 ◽  
Vol 99 (4) ◽  
pp. 405-411
Author(s):  
Elena Ju. Gorbatkova

Introduction. The important factors affecting health and performance of young people are the conditions of education, in particular, a comfortable microclimate in the classrooms of higher educational institutions. Materials and methods. In view of the urgency of this problem, an analysis was made of the microclimate parameters of educational organizations of different profiles (Ufa city, the Republic of Bashkortostan). 294 classrooms were studied in 22 buildings of 4 leading universities in Ufa. A total of 3,822 measurements were taken to determine the parameters of the microclimate. The analysis of ionizing radiation in the aerial environment of classrooms. There was performed determination of radon and its affiliated products content. In order to assess the conditions and lifestyle of students of 4 higher educational institutions of the city of Ufa, we conducted an anonymous survey of 1,820 students of I and IV years of education. Results. The average temperature in the classrooms of all universities studied was 23.9±0.09 C. The average relative humidity in all classrooms was 34.2 ± 0.42%. Analysis of ionizing radiation (radon and its daughter products decay) in the aerial environment of the classrooms and sports halls located in the basement determined that the average annual equivalent equilibrium volumetric activity of the radon daughter products (EROA ± Δ222Rn) ranged from 28 ± 14 to 69 ± 34.5 meter, which meets the requirements established by SanPiN. Conclusion. The hygienic assessment of the microclimate parameters of educational institutions of various profile revealed a number of deviations from the regulated norms. The results indicate the need to control the parameters of the microclimate, both from the administration of universities, and from the professors. According to the results of the study, recommendations were prepared for the management of higher educational institutions in Ufa.


2012 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Hueyling Tan

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.


2018 ◽  
Author(s):  
V.M. Alakin ◽  
G.S. Nikitin

Приведены результаты исследований экспериментального картофелекопателя с ротационной сепарирующей поверхностью. Особое внимание уделяется обоснованию конструктивных параметров и определению рабочих характеристик нового сепарирующего устройства. На основе анализа результатов экспериментальных исследований определены наиболее оптимальные режимы работы экспериментального картофелекопателя.Research results of an experimental potato digger with rotational separating web are published in this article. Special attention is paid to definition of design characteristics and performance data of the new separating device. Admissible operating modes are defined on the basis of the analysis of results of pilot studies of the experimental potato digger.


1993 ◽  
Vol 32 (2) ◽  
pp. 226-228
Author(s):  
Zakir Hussain

The book; under review provides a valuable account of the issues and factors in managing the irrigation system, and presents a lucid and thorough discussion on the performance of the irrigation bureaucracies. It comprises two parts: the first outlines the factors affecting irrigation performance under a wide range of topics in the first five chapters. In Chapter One, the authors have attempted to assess the performance of the irrigation bureaucracies, conceptualise irrigation management issues, and build an empirical base for analysis while drawing upon the experience of ten country cases in Asia, Africa, and Latin America. The Second Chapter focuses on the variations in the management structures identified and the types of irrigation systems; and it defines the variables of the management structures. The activities and objectives of irrigation management are discussed in Chapter Three. The objectives include: greater production and productivity of irrigation projects; improved water distribution; reduction in conflicts; greater resource mobilisation and a sustained system performance. The authors also highlight the performance criterion in this chapter. They identify about six contextual factors which affect the objectives and the performance of irrigation, which are discussed in detail in Chapter Four. In Chapter Five, some organisational variables, which would lead to improvements in irrigation, are examined.


2020 ◽  
Vol 26 (1) ◽  
pp. 86-93
Author(s):  
D. V. Slivinsky ◽  
I. A. Fomina ◽  
D. G. Menshikh

The presented study determines the role of business aviation in the modern economy and examines the specific features of its development in Russia.Aim. The study aims to analyze the development of business aviation in Russia and its correlation with economic development in general.Tasks. The authors determine the benefits of business aviation as a business tool, examine the specific features of the Russian business aviation market and problems of its development, and identify factors that affect the development of business aviation in Russia.Methods. This study uses the methods of comparative and retrospective analysis, cross-country comparison, systems approach, and expert analytics.Results. Business aviation is a new segment of civil aviation for Russia. Therefore, it is advisable to rely on foreign practices in the management of its development. In many countries, business aviation is a separate industry that specializes in providing transport services to a wide range of corporate clients and/or individuals. The development of this industry is associated with the economic growth rate and the development level of the national economy, and also depends on the national institutional specifics. This study describes the specific features of development of business aviation in Russia and problems arising in the organization and management of this type of business.Conclusions. The authors develop a system of factors affecting the development of business aviation in Russia, describe the major problems of this industry, and propose solutions. The results of this study can be used in the development (adjustment) of business aviation development strategies in Russia both at the industrial and corporate level, and in the implementation of the national policy in this field.


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