scholarly journals Time-Mean Helicity Distribution in Turbulent Swirling Jets

10.14311/776 ◽  
2005 ◽  
Vol 45 (6) ◽  
Author(s):  
V. Tesař

Helicity offers an alternative approach to investigations of the structure of turbulent flows. Knowledge of the spatial distribution of the time-mean component of helicity is the starting point. Yet very little is known even about basic cases in which Helicity plays important role, such as the case of a swirling jet. This is the subject of the present investigations, based mainly on numerical flowfield computations. The region of significantly large time-mean helicity density is found only in a rather small region reaching to several nozzle diameters downstream from the exit. The most important result is the similarity of the helicity density profiles. 

2018 ◽  
Vol 39 ◽  
pp. 43-65

Electoral Geography as part of political geography has not been significantly represented as a subject of research in Croatia and neighboring countries, and there is, in particular, a shortage of papers that deal with the in depth analysis of the spatial components of elections. Therefore, the subject of this paper is an analysis of certain demographic indicators or factors and their impact on the spatial distribution of votes in US presidential elections, in the period from 2004 until the last elections in 2016. The selected include racial structure, emphasized in this paper, age-gender structure and urban-rural differences. Analysis has shown that some of the mentioned factors have a greater impact on spatial distribution of votes, having in mind that the racial structure is the starting point for observing spatial distribution of votes and is hierarchically superior to the other observed factors. People of the same racial origin generally have similar voting preferences, and the other factors mostly depend on that factor.


2020 ◽  
Vol 75 (1) ◽  
pp. 1-27
Author(s):  
Alex Bliss

The advent of the Portable Antiquities Scheme (PAS) has added a great deal to our understanding of prehistoric metal artefacts in England and Wales, namely in expanding enormously the corpuses of objects previously thought to be quite scarce. One such artefact type is the miniature socketed 'votive' axe, most of which are found in Wiltshire and Hampshire. As a direct result of developing such recording initiatives, reporting of these artefacts as detector finds from the early 2000s onwards has virtually trebled the number originally published by Paul Robinson in his 1995 analysis. Through extensive data-collection, synthesising examples recorded via the PAS with those from published excavations, the broad aims of this paper (in brief) are as follows: firstly, produce a solid typology for these artefacts; secondly, investigate their spatial distribution across England and Wales. As a more indirect third aim, this paper also seeks to redress the imbalance of focus and academic study specifically applying to Hampshire finds of this object type, which despite producing a significant proportion of the currently known corpus have never been the subject of detailed analysis.


Author(s):  
رضوان جمال الأطرش ◽  
نجوى نايف شكوكاني

        الملخّص      هدف هذا البحث إبراز إمكانية التأثر العملي بأسلوب التعليل في القرآن الكريم، ومحاولة البحث في تطبيقاته في واقع العملية التعليمية من العالم والمتعلم، بحيث لم يقتصر على الدراسة اللغوية أو الأصولية النظرية؛ وخصوصاً بعد التعريف بهذا الأسلوب وأدواته وأهميته وبيان اللوازم الخاصة للعالم والمتعلم للتأثر به، وقد تم ذلك من خلال استخدام المنهج الاستقرائي بتتبع أعمال العلماء في ذلك وتم رصد أقوال المفسرين فيما يتعلق بالأساليب البيانية وآيات التعليل ووجوه الإعجاز القرآني، ومن ثم استُخدم المنهج التحليلي لإثبات ذلك الأثر وإثبات وجود إشارات وأدلة على مظاهر التأثر؛ واستنتاج حقيقة إمكانية استمرارية البحث في كل أدوات وآيات ومواضيع ذلك الأسلوب بنفس الطريقة التي تمّ طرحُها، مما يثري هذا المجال، ويفتح العقول ويدفعها للنظر والتدبر والبحث في آي القرآن، وفي كل المناحي، منطلقةً من فكر التجديد، والإفادة من مستجدات العصر وعلومه ضمن ضوابط العقيدة الغراء والشرع الحنيف. الكلمات المفتاحية: أسلوب التعليل، أدوات أسلوب التعليل، التدبر، التعليم التقليدي، أثر.  Abstract This study intends to highlight the possible practical impact of the principles of argumentation found in the Qur’an. The study attempts to apply the principles on the actual education process of the scholars and students without limiting it to linguistic studies or theoretical principles. This was done after introducing the principles of reasoning, its tools, its importance, and disclosing the special requirements for the scholars and students in order to be influenced by the latter principles.  The work used inductive method to track the works of the scholars on the subject and observe the opinions of the Qur’an-commentators in relation to principles of explanation, verses of argument, and aspects of Qur’anic Inimitability. Analytical method was used to establish the impacts of the Qur’anic arguments; to prove the presence of signs and evidences for the manifestation of the impacts; and to make the continuity of this research possible in all the tools, verses and topics related to the principles of Qur’anic argument. Among those things that enrich this work is that it opens the minds, and pushes it to ponder and study the verses of the Qur’an. For every direction it becomes the starting point for the innovative thinking, and benefit for the new age and its sciences while maintaining the harmony with the principles of creed and the true SharÊ‘ah. Keywords: Principles of Argumentation, Tools of Argumentation Principles, Thinking, Traditional Education, Effect.


This book provides students and researchers in fluid engineering with an up-to-date overview of turbulent flow research in the areas of simulation and modeling. A key element of the book is the systematic, rational development of turbulence closure models and related aspects of modern turbulent flow theory and prediction. Starting with a review of the spectral dynamics of homogenous and inhomogeneous turbulent flows, succeeding chapters deal with numerical simulation techniques, renormalization group methods and turbulent closure modeling. Each chapter is authored by recognized leaders in their respective fields, and each provides a thorough and cohesive treatment of the subject.


1982 ◽  
Vol 18 ◽  
pp. 309-317 ◽  
Author(s):  
Anthony Fletcher

Their sense of national identity is not something that men have been in the habit of directly recording. Its strength or weakness, in relation to commitment to international causes or to localist sentiment, can often only be inferred by examining political and religious attitudes and personal behaviour. So far as the early modern period is concerned, the subject is hazardous because groups and individuals must have varied enormously in the extent to which national identity meant something to them or influenced their lives. The temptation to generalise must be resisted. It is all too easy to suppose that national identity became well established in England in the Tudor century, when a national culture, based on widespread literacy among gentry, yeomen and townsmen, flowered as it had never done before, when the bible was first generally available in English, when John Foxe produced his celebrated Acts and Monuments, better known as the Book of Martyrs. Recent work reassessing the significance of Foxe’s account of the English reformation and other Elizabethan polemical writings provdes a convenient starting point for this brief investigation of some of the connections between religious zeal and national consciousness between 1558 and 1642.


1982 ◽  
Vol 19 (A) ◽  
pp. 359-365 ◽  
Author(s):  
David Pollard

The theory of weak convergence has developed into an extensive and useful, but technical, subject. One of its most important applications is in the study of empirical distribution functions: the explication of the asymptotic behavior of the Kolmogorov goodness-of-fit statistic is one of its greatest successes. In this article a simple method for understanding this aspect of the subject is sketched. The starting point is Doob's heuristic approach to the Kolmogorov-Smirnov theorems, and the rigorous justification of that approach offered by Donsker. The ideas can be carried over to other applications of weak convergence theory.


2014 ◽  
Vol 15 (3) ◽  
pp. 577-598
Author(s):  
Abul Quasem Al-Amin ◽  
Abdul Hamid Jaafar

Within a process of modeling exercise, this study aimed to understand appropriate selection criteria to identify key industries. There are many key sector identification linkage measures in the subject matter and sensitivity issue among them can be tricky because many of these measures differ only slightly but can result in outcomes that are quite dissimilar. With this background, we proposed an alternate approach that helps to resolve this issue. The proposed approach utilizes in this study by five sub-methods and high degree of the frequency of their occurrences in sub-methods to determine the key sectors. The study approach is applied to Malaysia as the public sector investment remains a large share in the national economy, like other developing countries, and the correct identification is still a challenge for sectoral planning. The experiences from this study can be used to guide appropriate public investment in Malaysia and elsewhere with similar economic forms.


2001 ◽  
Vol 69 (1) ◽  
pp. 111-123
Author(s):  
Nadia Wassef

In the light of postmodern debates in anthropology, ethnography offers anthropologists new ways of representing their objects of study. The politics involved in the production and consumption by feminist scholars and activists of women's representations in the Arab world, and Egypt specifically, provides the starting point of this article. Using an ethnographic text examining manifestations of ‘Islamic Feminism’ in Egypt, I explore problems in addressing the subject of veiling – a continuous favourite among researchers. Grappling with stereotypes, assumptions and pre-interpretations based on what we read before going to the field and the questions we formulate in our minds, I look towards strategies of engagement with research subjects where anthropologists can express their commitments to them. Research ethics and reflexivity offer no formulaic guarantees of better representations, but pave the way towards understanding one's motivations and urges ethnographers to examine the impact of their work, both on the immediate community, and with regard to larger power politics. Given the fluid nature of identities and the relative fixedness of representations, solutions do not appear in abundance. Working outside of unnecessary dichotomies and searching for incongruities presents interesting possibilities for future ethnographic research.


KronoScope ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 7-27
Author(s):  
Carl Humphries

Abstract “Being is said in many ways,” claimed Aristotle, initiating a discussion about existential commitment that continues today. Might there not be reasons to say something similar about “having been,” or “having happened,” where these expressions denote something’s being located in the past? Moreover, if history – construed not only as an object of inquiry (actual events, etc.) but also as a way of casting light on certain matters – is primarily concerned with “things past,” then the question just posed also seems relevant to the question of what historical understanding amounts to. While the idea that ‘being’ may mean different things in different contexts has indisputable importance, the implications of other, past-temporal expressions are elusive. In what might any differences of substantive meaning encountered there consist? One starting point for responding – the one that provides the subject matter explored here – is furnished by the question of whether or not a certain way of addressing matters relating to the past permits or precludes forms of intelligibility that could be said to be ‘radically historical.’ After arguing that the existing options for addressing this issue remain unsatisfactory, I set out an alternative view of what it could mean to endorse or reject such an idea. This involves drawing distinctions and analogies connected with notions of temporal situatedness, human practicality and historicality, which are then linked to a further contrast between two ways of understanding the referential significance of what is involved when we self-ascribe a relation to a current situation in a manner construable as implying that we take ourselves to occupy a unique, yet circumstantially defined, perspective on that situation. As regards the latter, on one reading, the specific kind of indexically referring language we use – commonly labelled “de se” – is something whose rationale is exhausted by its practical utility as a communicative tool. On the other, it is viewed as capturing something of substantive importance about how we can be thought of as standing in relation to reality. I claim that this second reading, together with the line of thinking about self-identification and self-reference it helps foreground, can shed light on what it would mean to affirm or deny the possibility of radically historical forms of intelligibility – and thus also on what it could mean to ascribe a plurality of meanings to talk concerning things being ‘in the past.’


2021 ◽  
Vol 9 (1) ◽  
pp. 28-35
Author(s):  
Mariya Podshivalova ◽  
S. Almrshed

The starting point of research on assessing the innovative capacity of an enterprise is the question of definitions. In this regard, authors initially turned to review of scientific literature on the subject of definitions variety for the term "enterprise innovative capacity". These data show that the wording of this term by both foreign and Russian researchers differs significantly. Authors propose a systematization of approaches to the definition and a corresponding graphical classification model, which highlights the evolutionary, resource, functional and process approaches. Further, a critical analysis of approaches to assessing enterprise innovative capacity is carried out. At the first stage, the content of modern assessment methods was studied, and at the second stage, the mathematical tools used were studied. Authors have formed a graphical representation of critical analysis results and based on it, they have concluded that among the approaches to assessing enterprise innovative capacity, the evolutionary approach should be recognized as promising, and among the methods of quantitative assessment – tools of economic statistics.


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