Theoretical Insights (theoretical + insight)

Distribution by Scientific Domains


Selected Abstracts


A Theoretical Insight into the Mechanism of the Silver-Catalysed Transsiliranation Reaction

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 7 2010
José Antonio Mayoral
Abstract DFT calculations on a silver-catalysed transsiliranation reaction (silylene transfer from a silirane to an alkene) have shown the key role of a silylenesilver ion in the catalyticcycle. Although the corresponding triflate-bound species has previously been detected by NMR and IR spectroscopy, no significant silylene-transfer activity is predicted for such a nonionised structure. Several experimental results can be explained by this new reaction mechanism. [source]


Titelbild: Fast Prediction of Selectivity in Heterogeneous Catalysis from Extended Brønsted,Evans,Polanyi Relations: A Theoretical Insight (Angew. Chem.

ANGEWANDTE CHEMIE, Issue 47 2009
47/2009)
Brønsted-Evans-Polanyi-Beziehungen sind im Bereich der heterogenen Katalyse bekannt für die schnelle Vorhersage von Aktivierungsbarrieren allein mit Kenntnis der Reaktionsenthalpien. Dieses Modell wurde nun von D. Loffreda et,al. auf die Hydrierung ungesättigter Aldehyde an Platin erweitert. In ihrer Zuschrift auf S.,9140,ff. finden die Autoren auf Grundlage von Dichtefunktionalrechnungen eine lineare Beziehung zwischen der Aktivierungsbarriere und der Stabilität des Vorstufenzustands. [source]


Fast Prediction of Selectivity in Heterogeneous Catalysis from Extended Brønsted,Evans,Polanyi Relations: A Theoretical Insight,

ANGEWANDTE CHEMIE, Issue 47 2009
David Loffreda Dr.
Lineare Beziehungen werden beobachtet, wenn man für die Hydrierung ungesättigter Aldehyde an Platinoberflächen die Energien der Übergangszustände () gegen die Energien der Vorstufenzustände () aufträgt (siehe Bild; FS=Endzustand). Mithilfe dieser Beziehung können die Energiebarrieren substituierter Derivate schnell und genau ermittelt werden, sobald die Reaktivität der Stammverbindung bekannt ist. [source]


Structural and Theoretical Insights into Metal,Scorpionate Ligand Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2007
Matthias Schwalbe
Abstract The syntheses of the complexes [M(TmMe)(CO)2(NO)] (M = Mo, W) by reaction of NOBF4 with [M(TmMe)(CO)3], are reported and their spectroscopic characterisation and crystal structures are described. The analogous Cr complex could not be prepared by this methodology. The complexes adopt the expected pseudo-octahedral geometry. Complexes [M(L)(CO)2(NO)] (M = Cr, Mo, W; L = Cp, Tp and TmMe) together with the hypothetical [Mo(CO)2(NO)]+ cation were subjected to DFT calculations. Geometry-optimised structures closely parallel the crystallographic determinations and indicate that the complex [Cr(TmMe)(CO)2(NO)] is not inherently unstable. The DFT calculations allow the assignment of the C,O and N,O stretches in the IR spectrum and give insight into both the M,NO bonding and the metal to tripodal ligand bonding. The electron-donor strengths are confirmed to lie in the order TmMe > Tp > Cp. A side reaction of the B,H moiety of the TmMe anion with NO+ results in the isolation of the dimethylformamide adduct of (trismethimazolyl)borane, providing further evidence that the reaction pathways of the TmR ligands are more varied and less passive than in the chemistry of the nitrogen-based scorpionates.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


Simulating Seepage into Mine Shafts and Tunnels with MODFLOW

GROUND WATER, Issue 3 2010
Jacob Zaidel
In cases when an equivalent porous medium assumption is suitable for simulating groundwater flow in bedrock aquifers, estimation of seepage into underground mine workings (UMWs) can be achieved by specifying MODFLOW drain nodes at the contact between water bearing rock and dewatered mine openings. However, this approach results in significant numerical problems when applied to simulate seepage into an extensive network of UMWs, which often exist at the mine sites. Numerical simulations conducted for individual UMWs, such as a vertical shaft or a horizontal drift, showed that accurate prediction of seepage rates can be achieved by either applying grid spacing that is much finer than the diameter/width of the simulated openings (explicit modeling) or using coarser grid with cell sizes exceeding the characteristic width of shafts or drifts by a factor of 3. Theoretical insight into this phenomenon is presented, based on the so-called well-index theory. It is demonstrated that applying this theory allows to minimize numerical errors associated with MODFLOW simulation of seepage into UMWs on a relatively coarse Cartesian grid. Presented examples include simulated steady-state groundwater flow from homogeneous, heterogeneous, and/or anisotropic rock into a vertical shaft, a horizontal drift/cross-cut, a ramp, two parallel drifts, and a combined system of a vertical shaft connected to a horizontal drift. [source]


Curricular Planning along the Fault Line between Instrumental and Academic Agendas: A Response to the Report of the Modern Language Association on Foreign Languages and Higher Education: New Structures for a Changed World,

DIE UNTERRICHTSPRAXIS/TEACHING GERMAN, Issue 2 2009
Ingeborg Walther
In calling for new governance structures and unified curricula, the MLA Report distinguishes between instrumental and constitutive views of language that characterize our often schizophrenic agendas of language acquisition on the one hand, and disciplinary knowledge on the other. This paper explores some common theoretical insights from the fields of language acquisition and cultural studies that interrogate these views, providing a basis for sustained collaboration around curricula among faculty on both sides of the divide. While these have already yielded the kinds of curricular innovations recommended by the Report, a case is made for more radical changes in hiring practices, distribution of teaching and service, reward structures, and graduate education , changes which have the capacity to transform the institutional values upon which they will also depend. [source]


The Economist as Engineer: Game Theory, Experimentation, and Computation as Tools for Design Economics

ECONOMETRICA, Issue 4 2002
Alvin E. Roth
Economists have lately been called upon not only to analyze markets, but to design them. Market design involves a responsibility for detail, a need to deal with all of a market's complications, not just its principle features. Designers therefore cannot work only with the simple conceptual models used for theoretical insights into the general working of markets. Instead, market design calls for an engineering approach. Drawing primarily on the design of the entry level labor market for American doctors (the National Resident Matching Program), and of the auctions of radio spectrum conducted by the Federal Communications Commission, this paper makes the case that experimental and computational economics are natural complements to game theory in the work of design. The paper also argues that some of the challenges facing both markets involve dealing with related kinds of complementarities, and that this suggests an agenda for future theoretical research. [source]


Moving Beyond Postdevelopment: Facilitating Indigenous Alternatives for "Development"

ECONOMIC GEOGRAPHY, Issue 4 2003
George N. Curry
Using the example of smallholder oil-palm production in Papua New Guinea, this article illustrates how elements of a market economy and modernity become enmeshed and partly transformed by local place-based nonmarket practices. The persistence, even efflorescence, of indigenous gift exchange, in tandem with greater participation in the market economy, challenges conventional notions about the structures and meanings of development. The introduced market economy can be inflected to serve indigenous sociocultural and economic goals by place-based processes that transform market relations and practices into nonmarket social relationships. These kinds of inflections of the market economy are common and widespread and therefore worthy of consideration for their theoretical insights into processes of social and economic change and the meanings of development. The article concludes by outlining some preliminary thoughts on how development practice could be modified to provide more scope for this process of inflection, so that development strategies accord better with indigenous sociocultural meanings of development. [source]


How Theories of Financial Intermediation and Corporate Risk-Management Influence Bank Risk-Taking Behavior

FINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 5 2001
Michael S. Pagano
This paper examines the rationales for risk-taking and risk-management behavior from both a corporate finance and a banking perspective. After combining the theoretical insights from the corporate finance and banking literatures related to hedging and risk-taking, the paper reviews empirical tests based on these theories to determine which of these theories are best supported by the data. Managerial incentives are the most consistently supported rationale for describing how banks manage risk. In particular, moderate/high levels of equity ownership reduce bank risk while positive amounts of stock option grants increase bank risk-taking behavior. The review of empirical tests in the banking literature also suggests that financial intermediaries coordinate different aspects of risk (e.g., credit and interest rate risk) in order to maintain a certain level of total risk. The empirical results indicate hedgeable risks such as interest rate risk represent only one dimension of the risk-management problem. This implies empirical tests of the theories of corporate risk-management need to consider individual sub-components of total risk and the bank's ability to trade these risks in a competitive financial market. This finding is consistent with the reality that banks have non-zero expected financial distress costs and bank managers cannot fully diversify their bank-related personal investments. [source]


New Directions in Natural Resource Management The Offer of Actor-Network Theory

IDS BULLETIN, Issue 4 2001
Nathalie A. Steins
Summaries The article offers theoretical insights from Actor-Network Theory (ANT) as to how natural resource management (NRM) perspectives might be enhanced. ANT asks us to abolish the conventional sociological practice of studying phenomena in terms of predefined categories and principles, as they hinder our analysis of how the stakeholders involved construct resource management processes and the way these constructions are used. In this analytical process, any (uncertain) outcome of NRM is regarded as an effect of the interplay amongst the different stakes in the resource and the way stakeholders continuously mobilise social and material resources in order to achieve their goals. Only by analysing how certain outcomes have been achieved can we develop our understanding of the dynamics and uncertainties involved in NRM. The article uses empirical examples from coastal management scenarios to illustrate these theoretical points. [source]


Internet-based information systems use in organizations: an information studies perspective

INFORMATION SYSTEMS JOURNAL, Issue 2 2003
Brian Detlor
Abstract. This case study investigates various ways in which different internet-based information systems (IS) are used by organizational participants. Borrowing theoretical insights on information behaviour accumulated over 50 years of information studies research, a conceptual framework is presented to help understand and assess the social and organizational impacts of internet-based IS. The framework describes the use of internet-based IS as a dynamic cycle of information needs,seeking,use activity situated in the context of a firm's information environment. Research questions pertain to the process of how individuals in organizations seek and use information from internet-based IS to satisfy information needs. In terms of information needs, this involves understanding the problem situations that lead participants to use internet-based IS, as well as the characteristics of those problems beyond subject matter. With respect to information seeking, this involves analysing how information from internet-based systems is displayed and formatted to signal their potential usefulness. In terms of information use, this involves how information obtained from internet-based systems is used in practice to resolve or redefine problems. Both quantitative and qualitative research methods are used. Data collection involves web tracking to identify significant episodes of internet-based IS activity, as well as one-on-one interviews to explore the context behind these episodes. Results suggest that it is possible and valuable to identify scenarios of internet-based IS use dominant in an organizational work setting. Doing so can help to identify ways to improve the situated use of internet-based IS that ameliorate the information needs,seeking,use cycle in firms. [source]


Employability enhancement through formal and informal learning: an empirical study among Dutch non-academic university staff members

INTERNATIONAL JOURNAL OF TRAINING AND DEVELOPMENT, Issue 1 2009
Beatrice Van Der Heijden
Although learning is generally perceived as a way to improve employees' current job performance, so far, no research has been conducted to explore the possible relationships between formal and informal learning, on the one hand, and employability, on the other. Though contemporary views stress the importance of the job as a powerful learning site, considerable research evidence underpinning these views is lacking. This paper goes into the impact of formal and informal learning upon employability. The influence of employee characteristics and organizational factors is also taken into account. An e-questionnaire was used to collect data among 215 Dutch non-academic university staff members. Our findings emphasize the necessity of Human Resource Development strategies that encompass a mix of formal and informal learning opportunities. In particular, participation in networks appears to be an important predictor for employability. With the outcomes of this study, we aim to contribute to the further development of theoretical insights regarding employability enhancement through learning possibilities embedded in the workplace. It seems that strategies that focus exclusively on enhancing informal on-the-job learning should not be encouraged. Our study is limited to one context and further research is required to investigate the generalizability of the findings to other occupations and/or countries. [source]


Perpetual Imagining: Nationhood in a Global Era

INTERNATIONAL STUDIES REVIEW, Issue 1 2003
Sheila L. Croucher
At the turn of the millennium, nations and nationalism persist in spite of scholarship that has both anticipated and proclaimed their demise. This article assesses the empirical reality and the state of scholarly analysis on nationhood in the context of globalization beginning with an overview and update of the definitional dilemma that surrounds the concept of the nation. Subsequent sections review competing conceptualizations of nation as either premodern, modern, or postmodern and synthesize existing theoretical insights, leading to the conclusion that even though nations are, indeed, constructed, nothing suggests that their construction was, is, or will be restricted to the modern era. [source]


Gender, class, work-related stress and health: toward a power-centred approach

JOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 2 2001
Ann-Sylvia Brooker
Abstract The purpose of this paper is to consider how gender, class and power have been addressed in the work stress literature and to propose an alternative approach that highlights the role of power in the development of work-related stress. We begin with a discussion and critique of prominent work-related stress models. The models' conceptualizations of work-related stress and their relationships to issues of class and gender are used as focal points for discussion. We show that explanations for gender or class differences in stress vary markedly by disciplinary perspective. Some models emphasize individual coping mechanisms, while other models focus on individual-level exposures or the work environment, in the production of work-related stress. Notions of power or control are often invoked in these models, but they tend to be narrowly conceptualized. Often the research presents a series of empirical findings rather than an integrated conceptual model which clearly specifies the pathways by which individual work experiences are linked to health and to the broader social context. Drawing on empirical findings and theoretical insights from a broad range of disciplinary perspectives, we build a conceptual framework relating power to work-related stress. This model can provide us with a deeper understanding of the determinants of stress, the relationships between stress and the broader social context, and the relationships between stress and social factors such as class and gender. Specifically, we suggest that power can influence work-related stress through the distribution of stressors in the workplace and via meaning. Copyright © 2001 John Wiley & Sons, Ltd. [source]


,Modern language' or ,spin'?

JOURNAL OF NURSING MANAGEMENT, Issue 5 2004
Nursing, newspeak', organizational culture: new health scriptures
A new managerial language of modernization has accompanied political restructuring of the National Health Service. Corporate goals of efficiency and audit have been integrated with the ideological manifesto of New Labour in stressing citizenship, inclusion and empowerment. Drawing on the theoretical insights of anthropology and sociology, this article critically reviews the relationship between health policy, organizational culture and nursing practise through an exploration of language in terms of ,rhetoric', ,jargon' and ,metaphor'. It is suggested that beyond the bewildering vocabulary of ,buzz words' is a fundamental contradiction between the ethic of caring and the expectations of Government. Finally thought is given to the role of professional education and training where intellectual engagement with the ritual categories of ,newspeak' is a subversive act. [source]


Speaking and Hearing Clearly: Talker and Listener Factors in Speaking Style Changes

LINGUISTICS & LANGUAGE COMPASS (ELECTRONIC), Issue 1 2009
Rajka Smiljani
This article provides an overview of the research concerning the nature of the distinct, listener-oriented speaking style called ,clear speech' and its effect on intelligibility for various listener populations. We review major findings that identify talker, listener and signal characteristics that contribute to the characteristically high intelligibility of clear speech. Understanding the interplay of these factors sheds light on the interaction between higher level cognitive and lower-level sensory and perceptual factors that affect language processing. Clear speech research is, thus, relevant for both its theoretical insights and practical applications. Throughout the review, we highlight open questions and promising future directions. [source]


Some recent contributions to routing and location problems

NETWORKS: AN INTERNATIONAL JOURNAL, Issue 2 2003
A. Corberán
Abstract This report is more than just a summary of some results of the present state of the art in routing and location problems. It summarizes theoretical insights, modeling approaches, and heuristic and exact algorithms for routing and location presented at the CORAL 2003 Workshop held in Tenerife (Spain). © 2003 Wiley Periodicals, Inc. [source]


On the online shortest path problem with limited arc cost dependencies

NETWORKS: AN INTERNATIONAL JOURNAL, Issue 4 2002
S. Travis Waller
Abstract This paper is concerned with the stochastic shortest path problem with recourse when limited forms of spatial and temporal arc cost dependencies are accounted for. Recourse is defined as the opportunity for a decision maker to reevaluate his or her remaining path when en-route information is available. Formulations with recourse typically provide opportunities for corrective actions when information becomes available; information here is modeled as arc cost dependencies, defined as spatial and temporal. System properties are stated and proved and solution algorithms are developed for limited cases of spatial and temporal arc cost dependencies. The numerical results verify some of the theoretical insights and demonstrate the applicability of the introduced algorithms. © 2002 Wiley Periodicals, Inc. [source]


Commercial applications of porous Si: optical filters and components

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2007
V. Kochergin
Abstract It is shown that porous Silicon in various geometries and morphologies can be used for novel optical elements by combining theoretical insights with suitable porous structures and some pre- and post-processing of the Silicon. The paper restricts itself to light propagation in the pore direction. Theoretical and experimental results will be presented for the following novel optical elements: environmentally stable optical components from mesoporous Silicon, long wave pass filters, macroporous Silicon UV Filters, and polarization components for the UV range. Either new components are presented, mostly with first experimental results, or the state-of-the art for previously discussed elements is considerably improved upon. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Perceived Health Needs of Urban African American Church Congregants

PUBLIC HEALTH NURSING, Issue 5 2001
Kathleen A. Baldwin Ph.D.
Theory-based assessment of congregant expectations and needs should be conducted prior to beginning a parish nurse program. However, no such assessments are found in the literature. Using Andersen's Health Access Model as a framework, investigators conducted interviews with 117 randomly selected congregants in five urban African American churches to describe their perceived needs and expectations. Causing most concern were the following: (a) symptoms of illness,high blood pressure (50.4%), dental problems (43.6%), and back pain (41%); and (b) health habits/risks,weight (75%), exercise (63%), and diet (63%). Younger adults were significantly more concerned about all aspects of their health than their older counterparts. Women were significantly more likely to express concern about health habits and health risks than males. No significant relationship was found between perceived need and access to care. Although terming health care services "adequate", congregants expressed many unmet health needs. This seemingly contradictory finding may illuminate a concrete role for the parish nurse, i.e., addressing personal health care concerns not alleviated by the current "adequate" health care delivery system. This study's significance lies not only in providing programming guidance, but also in theoretical insights into the role of the parish nurse. [source]


Moral Hazard and Other-Regarding Preferences

THE JAPANESE ECONOMIC REVIEW, Issue 1 2004
Hideshi Itoh
The paper aims at obtaining new theoretical insights by combining the standard moral hazard models of principal,agent relationships with theories of other-regarding preferences, in particular inequity aversion theory. The principal is in general worse off, as the agent cares more about the wellbeing of the principal. When there are multiple symmetric agents who care about each other's wellbeing, the principal can optimally exploit their other-regarding nature by designing an appropriate interdependent contract such as a "fair" team contract or a relative performance contract. The approach taken in this paper can shed light on issues on endogenous preferences within organizations. [source]


The Cultures of Capitalism: Glasgow and the Monopoly of Culture

ANTIPODE, Issue 1 2009
Eliot M. Tretter
Abstract:, While many have recognized since the 1970s the strong relationship between culture and urban renewal, particularly as cities began to use cultural amenities to change their images and lure potential investors, little has been written about how and why cultural assets may be valued investments in their own right. There is at least one notable exception, in the work of David Harvey, and this approach takes as its starting point the importance of the monopoly aspects of culture, particularly for rents, competition and fixed capital. In part, I bring Harvey's theoretical insights on the political economy of culture to bear on the case of Glasgow, Scotland, in the 1980s, and particularly its nomination as the European City of Culture, with particular attention paid to how the economics of culture is related to local politics. [source]


Looking Forward by Looking Back: May Day Protests in London and the Strategic Significance of the Urban

ANTIPODE, Issue 4 2004
Justus Uitermark
This paper deals with the question of how oppositional movements can adapt their protest strategies to meet recent socio-spatial transformations. The work of Lefebvre provides several clues as to how an alternative discourse and appropriation of space could be incorporated in such protest strategies. One of the central themes in Lefebvre's work is that the appearances, forms and functions of urban space are constitutive elements of contemporary capitalism and thus that an alternative narrative of urban space can challenge or undermine dominant modes of thinking. What exactly constitutes the "right" kind of alternative discourse or narrative is a matter of both theoretical and practical consideration. The paper analyses one case: the May Day protests in London in 2001, in which a protest group, the Wombles, managed to integrate theoretical insights into their discourse and practice in a highly innovative manner. Since cities, and global cities in particular, play an ever more important role in maintaining the consumption as well as production practices of global capitalism; they potentially constitute local sites where global processes can be identified and criticised. It is shown that the Wombles effectively made use of these possibilities and appropriated the symbolic resources concentrated in London to exercise a "lived critique" of global capitalism. Since the Wombles capitalised on trends that have not yet ended, their strategies show a way forward for future anti-capitalist protests. [source]


Examining understanding, acceptance, and support for the biorefinery concept among EU policy-makers

BIOFUELS, BIOPRODUCTS AND BIOREFINING, Issue 3 2009
Philip Peck
Abstract This paper outlines how an understanding of the processes of building cognitive and sociopolitical legitimacy is relevant to the formation of a biorefining sector. First we describe a number of theoretical insights into challenges faced by emerging industries and how these can relate to the formation of a biorefining sector. Second, we present the conduct and results of an initial exploration of understanding, acceptance, and support for the biorefinery concept among a sample of actors in the EU policy community. General conclusions of this study are then provided in these two areas. Addressing theory versus evidence from the fi eld, it is found that many phenomena predicted by theory indeed appear in the empirical results and seem immediately relevant to the formative biorefining industry. Analysis of the perceptions of members of the policy community toward biorefinery-related environmental, social, policy, reputational and policy issues reveals that there are a number of areas where prompt action from the political and scientifi c communities could yield signifi cant benefi ts. We conclude that theories enfolding the concepts of cognitive and sociopolitical legitimacy are relevant to discussions of biofuels, bioproducts and biorefining. Importantly, proponents of the biorefinery concept can draw upon a broad body of knowledge generated in both related and non-related industries, to support their work reducing barriers to the emergence of commercial biorefineries. A key area in this regard will be improved communication of biorefinery contributions to sustainable development. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd [source]