scholarly journals Comprehensive study of sodium, copper, and silver clusters over a wide range of sizes 2≤N≤75

2009 ◽  
Vol 131 (17) ◽  
pp. 174510 ◽  
Author(s):  
Masahiro Itoh ◽  
Vijay Kumar ◽  
Tadafumi Adschiri ◽  
Yoshiyuki Kawazoe
Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 715
Author(s):  
Alexander Schäfer ◽  
Gerd Reis ◽  
Didier Stricker

Virtual Reality (VR) technology offers users the possibility to immerse and freely navigate through virtual worlds. An important component for achieving a high degree of immersion in VR is locomotion. Often discussed in the literature, a natural and effective way of controlling locomotion is still a general problem which needs to be solved. Recently, VR headset manufacturers have been integrating more sensors, allowing hand or eye tracking without any additional required equipment. This enables a wide range of application scenarios with natural freehand interaction techniques where no additional hardware is required. This paper focuses on techniques to control teleportation-based locomotion with hand gestures, where users are able to move around in VR using their hands only. With the help of a comprehensive study involving 21 participants, four different techniques are evaluated. The effectiveness and efficiency as well as user preferences of the presented techniques are determined. Two two-handed and two one-handed techniques are evaluated, revealing that it is possible to move comfortable and effectively through virtual worlds with a single hand only.


2013 ◽  
Vol 25 (1) ◽  
pp. 1-22
Author(s):  
J. Anitha ◽  
R. Krishnaveni

Literature has shown that various studies have dealt with different professional features of teaching and they have focused on one or few professional characteristics of educators. In spite of the immense amount of literature on educator characteristics, a comprehensive study that would encompass the vital professional characteristics of an educator in total is lacking. This has instigated the researcher to take up the study to identify the professional characteristics of an educator. An attempt was made in identifying the educators' characteristics using student outcome as a boundary criterion to select the characteristics from among several that are available in the literature. Therefore, a new model of professional characteristics of educators was proposed. This paper discusses in detail, the characteristics of a profession in general and the wide range of educator’s characteristics as studied in previous researches. The paper presents a wide scope for the models developed to be studied in depth to appreciate and investigate more about the professional characteristics identified through this review of literature. The models may also be tested empirically for further accumulation of knowledge in the field.


Author(s):  
Hashem Ashrafiuon ◽  
Nabih M. Alem ◽  
B. Joseph McEntire

Abstract A comprehensive study of the effect of Head-Supported Devices (HSDs) on the neck loading during helicopter accidents is presented. The new Articulated Total Body (ATB) model which treats the neck as a deformable segment was used for crash simulation. Different categories of human and manikin subjects were considered under several crash scenarios. Simulations were theoretically designed to include a wide range of HSDs by changing their weights and C. G. (center of gravity) locations relative to the head and studying the effects of these changes. HSDs were only included as added weight and inertia to the head and their possible detachment has not been modeled in the study. Hence, two typical detachable devices were modeled and selected simulations were repeated and compared not only to provide a theoretical measure of accuracy for the original results but also to see the effect of separation of these devices from the helmet.


The Tennessee Valley Authority, under sponsorship of the Public Health Service, National Air Pollution Control Administration, initiated a comprehensive study titled ‘ Full scale study of plume rise at large electric generating stations’ in 1963. The variability of plant sizes, stack heights, and stack configurations accommodated full scale assessment of plume rise over a wide range of meteorological and operational conditions.


Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1075 ◽  
Author(s):  
Venkatesh Vijayaraghavan ◽  
Liangchi Zhang

The discovery of hybrid boron nitride–carbon (BN–C) nanostructures has triggered enormous research interest in the design and fabrication of new generation nanocomposites. The robust design of these nanocomposites for target applications requires their mechanical strength to be characterized with a wide range of factors. This article presents a comprehensive study, with the aid of molecular dynamics analysis, of the tensile loading mechanics of BN–C nanosheet reinforced polyethylene (PE) nanocomposites. It is observed that the geometry and lattice arrangement of the BN–C nanosheet influences the tensile loading characteristics of the nanocomposites. Furthermore, defects in the nanosheet can severely impact the tensile loading resistance, the extent of which is determined by the defect’s location. This study also found that the tensile loading resistance of nanocomposites tends to weaken at elevated temperatures. The interfacial mechanics of the BN–C nanocomposites are also investigated. This analysis revealed a strong dependency with the carbon concentration in the BN–C nanosheet.


Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 34 ◽  
Author(s):  
Ileana Andreea Ratiu ◽  
Hossam Al-Suod ◽  
Małgorzata Bukowska ◽  
Magdalena Ligor ◽  
Bogusław Buszewski

Honey is a natural sweetener, with an osmotic effect on microorganisms due to the increased sugar content and low amount of water. Cyclitols are minor constituents of honey. They play a defensive role in plants against unfavorable environmental conditions. Honey’s physicochemical properties can vary, resulting in a wide range of colors, flavors, scents, antioxidant activity, dissimilar values of pH, acidity, electrical conductivity, etc. Some literature regarding correlation between honey types is already available, but a comprehensive study displaying an ample evaluation of multifarious aspects is still needed. This study focuses on the correlation between 18 honey types, originating from 10 countries, collected during four years, summarizing a total of 38 samples. A total of 6 physicochemical properties and 18 target components (sugars and cyclitols) were considered as variables. A correlation analysis is presented between the investigated parameters and between honey types, together with the statistical analysis which allowed for observation of the clusters’ distribution according with the investigated variables.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniela Tabuani ◽  
Walter Granelli ◽  
Giovanni Camino ◽  
Michael Claes

AbstractIn the field of polymer nanocomposite materials, carbon nanotubes have attracted lots of research interests in the recent past for their potentialities in improving a wide range of polymer properties. We present here a comprehensive study on polypropylene/carbon nanotube composites evaluating the morphology as well as the thermal behaviour of the prepared systems. Pristine as well as -COOH functionalised carbon nanotubes were taken into account and melt mixed at different weight fractions with PP; the crystallisation characteristics of the material were evaluated by means of DSC and XRD and the thermal behaviour was assessed through TGA analyses. The nanotubes appear to affect significantly the properties of the matrix in a way notably dependent on the functionalization and on the filler amount.


2019 ◽  
Vol 20 (2) ◽  
pp. 522-534
Author(s):  
T. Balinyan ◽  
L. Derecha ◽  
Yu. Nosatenko

The article considers the need for a comprehensive study of biological damage to fibrous materials by scanning electron microscopy. The main types and characteristics of fibers and fibrous materials, their types of damage, in particular, biological, and the mechanism of their formation are described. It is shown that with modern methods for studying morphological characteristics, the most effective is the method of scanning electron microscopy, which makes it possible to directly study the object in a wide range of magnifications. The use of scanning electron microscopy makes it possible to identify qualitatively new volumetric microsigns when conducting studies of fibrous materials. Biological damage agents (biofactors) are considered — microbiological (bacteria, microbes, fungi, blue-green algae), phytological (mosses, lichens, higher plants, algae), zoological (insects, birds, mammals). Attention is focused on the study of injuries caused by mold caused by moths, dogs, etc. Conducting a comprehensive study of various types of damage to materials of various fibrous nature allows us to obtain an information database, the possibility of differentiating chemical, mechanical, thermal and biological damage, identifying microsigns that individualize one or another object (factor) of action, influence, increasing the potential for obtaining trace information about the actual data and circumstances of the event in those cases when only by external morphological features of the diagnosis It is not possible to repair damage. The data obtained indicate the effectiveness of the chosen research area. The results of the studies are positive for creating the optimal research scheme, methods of microscopic studies of damage to materials of fibrous nature in order to solve diagnostic, identification and situational tasks of forensic examination.


Author(s):  
Holikova Natalia

Background. One of the main issues of linguistics of the XX – early XXI century is a comprehensive study of the concept of discourse, which reflects a variety of real manifestations of human language communication in certain social spheres of its communicative space. The actualization of this concept in various scientific fields, the representatives of which study the essence and mechanisms of interaction of constants of such linguistic and philosophical dichotomies as “language and society”, “language and man”, has led to the need for its clear definition and typology of discourses etc. Despite the fact that linguists use a number of methods of discursive analysis of linguistic units, there is currently no single approach to their study within the theory of discourse.The purpose of the article is to identify and substantiate the features of the literary text in terms of modern discourse. The main objectives of the article: to determine the typological and categorical features of artistic discourse, to establish and describe the most important aspects of the study of artistic texts of different genres within discourse.Methods. The paper uses general scientific methods of observation, analysis, synthesis, comparison; linguistic methods, including the descriptive method – to interpret the discursive status of the literary text; the method of integrative analysis, which is the basis of a comprehensive study of a set of different aspects used in the study of the literary text as the embodiment of individualauthorial communicative intentions; the contextual-interpretive method – to identify probable reading strategies of reception of the literary text and its components.Results. The concept of discourse in the broadest sense is associated with all manifestations of communication. Discourse is a consequence of modeling knowledge structures that provide strategic planning, flow and control of communication, the operation of mechanisms of communicative competence, regulation of interactivity processes and more. An important communicative-semantic segment of the holistic nature of the analyzed concept is its interaction with various factors that reflect the essence of communication, in particular with the concept of the text. The linguistic tradition still has a great influence on the development of theoretical principles of categorization and typology of the concept of discourse, because until recently the discourse was often identified with the text as a complex linguistic sign that arises as a result of the process of language formation. Currently, researchers outline the structural and semantic parameters of the text with a number of features that also appear relevant and objective for the discourse: completeness; coherence; integrity; lexical, grammatical, logical, stylistic, semantic coherence; compositional completeness; communicative and pragmatic orientation, etc. Differentiation of discourses is one of the most important issues of modern discourse, which is currently a problem that researchers, based on a wide range of different socio-linguistic manifestations of communication, solve differently. To establish a typology of discourses, as well as texts, it is necessary to develop common criteria for their classification and determine the main categories of text and discourse. Artistic discourse, in contrast to other discourses, involves indirect communication of the author (sender) with numerous readers (addressees). When creating a text, the writer predicts the expected reaction to its content from readers, instead of “translating” the literary text into the discourse, the recipients carry out in their own way, based on their own knowledge, experience, feelings and emotions. The interaction of the addressee author with numerous addressees is devoid of real communicative factors, in particular temporal and local fixation. Despite the lack of direct contact, the writer's communicative influence on readers is obviously effective: if the artist has a deep knowledge of the language, individualizes and emphasizes linguistic means, it evokes a certain attitude to his literary texts and their evaluation by readers.Discussion. At the present stage of development of texts of any styles and genres requires discursive analysis, because in the language of fiction recorded authorial intentions that should “decipher” speakers in the process of dynamic cognition of semantic and semantic depths of a text, involving their own practical experience and knowledge during its decoding. We see prospects for further research of this topical problem in the study of features of artistic discourses of classic writers and famous contemporary artists, whose language creation is organically connected with the development of the Ukrainian literary word as an important component of the linguistic and cultural universe.


2017 ◽  
Vol 7 (1) ◽  
pp. 211-218
Author(s):  
Посметьев ◽  
Valeriy Posmetev ◽  
Никонов ◽  
Vadim Nikonov ◽  
Посметьев ◽  
...  

Currently in Russia there is a wide range of hauling vehicles of domestic and foreign production for hauling forest. Despite the perfection of modern hauling cars constructions, they have several disadvantages, unnecessarily reducing their effectiveness. In recent years in our country and abroad, the intensive research is held on the development of promising technologies for the transport of forest based on the use of logging vehicles operated automatically, remotely and using combination of these methods. The developers, based on accumulated experience of the creation of "autopilot" to work in the quarries, roads, and tractor units in agricultural production and in other industries, are faced with the difficulties of adapting such machines for the conditions of their movement on forest roads. The main problem of the implementation and effective use of "autopilot" hauling vehicles is the absence or underdevelopment of the technical means of ensuring information and communication technologies of transport network in the vast territories of the forest fund within the scope of activities of logging companies and their remoteness from the end consumer. With the aim of studying the possibility of using remote control for logging vehicles, the authors propose a concept design of a timber truck with remote control, mounted on the chassis of serial trucks 63501-996 with the wheel formula 8 × 8 and equipped with manipulator SF-85C.For a full justification of working and design parameters of the proposed design of the timber truck with remote control, tasks for a comprehensive study of the machine are set, taking into account domestic and foreign experience and specific features of operation in terms of timber production.


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