3,258 research outputs found
Semiclassical reaction rate constant calculations: investigation of anharmonicity and quantum effects
No full textSemiclassical transition state theory (SCTST) is a relatively simple method for the computation from first principles of reactive rate constants, including quantum effects while accounting for anharmonicity and the coupling between reactive and bound modes.[1-3] In this talk, I will illustrate how we have developed this technique for practical applications[4-7] involving the study of phenomena like kinetic isotope effects, heavy atom tunneling, and elusive conformer lifetimes.[5,6,8]
While many approximate reaction rate theories reduce to the parabolic barrier estimate for the tunneling correction at high temperatures, SCTST, which is based on vibrational perturbation theory (VPT2), gives the exact limit when one considers the leading order term in an expansion of powers of ħ2 of the tunneling transmission coefficient.[9-11] Our investigation of molecular reactive systems assesses the importance of the non-linear corrections to the parabolic barrier estimate of the transmission coefficient. When the reaction barrier is significantly anharmonic, it is mandatory to account for non-linear corrections; otherwise, the transmission coefficient overlooks a high-temperature regime which may be dominated by quantum reflection.[12] These results highlight the importance of having a theory such as SCTST that includes the correct high-temperature limit.
[1] W.H. Miller Faraday Discuss. Chem. Soc. 62, 40 (1977).
[2] W.H. Miller J. Chem. Phys. 62, 1899 (1975)
[3] R. Hernandez et al., Chem. Phys. Lett. 214, 129 (1993).
[4] C. Aieta, F. Gabas, M. Ceotto, J. Phys. Chem. A 120, 4853 (2016).
[5] C. Aieta F. Gabas, M. Ceotto, J. Chem. Theory Comput. 15, 2142 (2019).
[6] G. Mandelli, C. Aieta, M. Ceotto J. Chem. Theory Comput. 18, 623 (2022).
[7] J.R. Barker, MultiWell-2023 software suite; University of Michigan: Ann Arbor, Michigan, USA, 2023; http://clasp-research.engin.umich.edu/multiwell/
[8] G. Mandelli, L. Corneo, C. Aieta J. Phys. Chem. Lett. 14, 9996 (2023).
[9] E. Pollak, J. Cao, Phys. Rev. A, 107, 022203 (2023).
[10] E. Pollak, S Upadhyayula J. Chem. Phys. 160, (2024).
[11] E. Pollak J. Chem. Phys. 160, 150902 (2024).
[12] C. Aieta, M. Ceotto, E. Pollak, in preparation
A ritual of building. An experimentation into non-conventional geometry made of recycled material
No full textIs it possible to build geometrically complex architecture using waste? This is the question our research team posed to a small group of students within an experimental workshop. Their answer has been a self-built pavilion with a tensile roof made of recycled cardboard.
The design purpose was to provide a temporary structure that could act as a multi-religious building and host for one week several rituals and cultural activities. This building has been inaugurated, used and dismantled during the summer 2008.
Besides providing a material answer to a multifaceted and not yet clearly expressed need, the design process has been seen as an experiment on how to conciliate simple techniques with complex geometries. Apparently a contrast
International Legal Protection of Sovereign Bonds as Investments in International Investment Law
No full textDržavne obveznice so dolžniški vrednostni papirji, s katerimi se država zaveže, da bo imetniku tega vrednostnega papirja ob zapadlosti izplačala periodične donose in povrnila glavnico. Obveznice predstavljajo največji vir financiranja držav in s tem prevladujočo obliko javnega dolga. Naraščanje nevzdržnih dolžniških obveznosti držav lahko povzroči težave z odplačevanjem, kar za imetnike obveznic predstavlja tveganje, da država ne bo poravnala svojih obveznosti, in da bo prišlo do prestrukturiranja javnega dolga. Magistrsko diplomsko delo naslovi vprašanje, ali mednarodno investicijsko pravo imetnikom državnih obveznic s položajem investitorja omogoča uveljavljanje zahtevkov proti državi pred mednarodno investicijsko arbitražo. Arbitražna praksa je pokazala, da jedro problematike v tovrstnih primerih predstavlja vprašanje, ali so državne obveznice zajete s pojmom investicije po mednarodnem investicijskem pravu. To je v prvi vrsti odvisno od definicije investicije, ki jo vsebuje mednarodni investicijski sporazum. Praksa tribunalov pa je pokazala, da tudi v primeru široke definicije investicije ni mogoče z zagotovostjo trditi, da so državne obveznice z njo zajete. Neusklajeni pa so tudi pristopi tribunalov k presoji obstoja investicije po ICSID Konvenciji, čemur lahko deloma pripišemo različne odločitve, deloma pa se te razhajajo zaradi nasprotujočih si stališč o enovitosti transakcij primarnega in sekundarnega trga državnih obveznic. Magistrsko diplomsko delo obravnava tudi vprašanje, ali lahko za državne obveznice štejemo, da se nahajajo na ozemlju države gostiteljice in kakšen zahtevek mora investitor uveljavljati, da tribunal o njem lahko odloča. Opredeli tudi možne kršitve investicijskih standardov, do katerih lahko pride v primeru neplačila ali prestrukturiranja javnega dolga.Sovereign bonds are financial instruments which acknowledge the indebtedness and promise a repayment of principal and interest at the maturity to the holder of the security. Bonds are the largest source of financing for governments and thus the predominant category of sovereign debt. The growth of unsustainable debt obligations of States can lead to repayment problems, which pose a risk to bondholders that a State will default on its obligations and that the sovereign debt will be restructured. The thesis addresses the question as to whether international investment law allows holders of sovereign bonds with investor status to pursue claims against the State in international investment arbitration. The arbitral practice has shown that the fundamental question is whether sovereign bonds constitute a protected foreign investment under international investment law. This depends primarily on the definition of investment contained in the international investment treaty. However, it has been established that even in the case of a non-exhaustive list of assets falling within the definition of investment, the tribunals may still conclude that government bonds cannot be considered as a protected investment. Additionally, tribunals have taken different approaches to the consideration of whether sovereign bonds correspond to the inherent meaning of investment as contemplated by the ICSID Convention. Divergent decisions of the tribunals can be attributed to the difference of approaches and conflicting views of the tribunals on the unity of the economic operation at the primary and secondary market. The thesis also addresses the question of localisation of sovereign bonds in host state and the jurisdictional issue of contract and treaty claims. It also identifies possible violations of investment standards that may arise in the event of default or sovereign debt restructuring
Michael Pollak : eine soziologische Biographie
No full textDer folgende Text befasst sich mit der wissenschaftlichen Karriere und der Person Michael Pollaks. Es ist der Lebenslauf Pollaks, welcher in Episoden und Schwerpunkten dargestellt wird und es zum Ziel hat, einen Überblick zu erhalten, welcher in manchen Bereichen in wissenschaftliche und persönliche Details übergeht. Es ist ein Beitrag zur Geschichte der österreichischen, aber auch darüber hinaus in andere Länder reichenden Soziologie, welcher seinen Ursprung Anfang der 1970er Jahre nimmt und bis zum Ableben Pollaks und darüber hinaus reicht. Pierre Bourdieu liefert mit seiner Stellungnahme zu „einer Soziologie der Soziologen“ die Antwort, weshalb es von Interesse ist, sich mit der Geschichte der Soziologie und seiner Proponenten zu befassen. Denn es ist oft das als selbstverständlich wahrgenommen Detail, welches zusätzliches Interesse wecken sollte. Das Offensichtliche wird demnach eher zu Interesse führen, als es das Verborgene tut. Daher liegt das Interesse, neben ausgewählten Hauptwerken, vor allem Personen zur Sprache kommen zu lassen, die mit Michael Pollak auf persönlicher und/oder akademischer Ebene zu tun hatten. Diese liefern Ergebnisse die in einem Überblick an Hand der Kapitalsorten nach Bourdieu dargestellt werden. Die Verknüpfung der Inhalte der fünf Gespräche und ausgewählten Texten von und über Michael Pollak, geschieht in einer Gegenüberstellung der verschiedenen Sichtweisen in dieser übergeordneten Struktur. Das Ergebnis präsentiert sich in einem Netzwerk Pollaks, welches an Hand seiner Publikationen dargestellt wird. Weiter zeigt sich eine Ausgangshypothese, nämlich die Randstellung Pollaks in der österreichischen Soziologie, als eine Frage des Blickwinkels. Dieser hat maßgeblich Einfluss darauf, ob von einer Randstellung gesprochen werden kann oder nicht. Die dargestellten Nachrufe und Interviews zeigen nur einen Teil des Ganzen. Im Gegensatz dazu zeigt sich die Tragweite seiner Arbeiten und Leistungen, welche bis heute, in vor allem methodischer Hinsicht, immer noch Geltung haben. Außerdem wird der ständige Austausch zwischen Michael Pollak mit seinem privaten und wissenschaftlichen Umfeld dargestellt und auch die Zielstrebigkeit bzw. das Engagement vor Augen geführt, mit welcher Pollak die inspiratorische Kraft, die sein Soziologieverständnis und seine Persönlichkeit bis heute noch in Teilen der Disziplin und in seinem privaten Umfeld hinterlassen hat.This thesis explores the scientific career and personality of Michael Pollak. In his biography, I focus on episodes and key aspects of his academic and personal life aiming to give an overview and explore his personal circumstances why he studied HIV research. This thesis contributes to Austrian sociology, however Michael Pollak’s research need to be addressed in a European and international context due to his multilingualism approach. In this present thesis, I studied Pollak’s scientific career starting in the beginnings of the 1970s until 1992 and other contributions beyond his death. Beside his most well known works on HIV/ Aids and the Holocaust, I explored Bourdieu´s question “why it is necessary to study sociology of sociologist”. Therefore, I interviewed Pollak’s family members and academic colleagues who gave insights in his academic and personal life using Pierre Bourdieu´s capital theory. The content of the interviews, main research – articles and books written by and about Michael Pollak – was structured and compared according to Bourdieu´s capitals aiming to connect different point of views. The findings show a dynamic network of Michael Pollak that is displayed in his publications. Further, the hypothesis that Michael Pollak has been marginalised in the Austrian sociology cannot be rejected. However, Pollak’s impact on current research, especially related to his method of oral history, still remains. The lively exchange about Pollak’s academic career and research exists nowadays mostly in his private environment. Michael Pollak’s understanding of sociology and society as driving force inspired me to conduct this thesis and should be considered in future research
L’apporto italiano nella ricostruzione post-terremoto in Perù.
No full textPerché investigare il costruire in terra cruda in un epoca in cui la tecnologia ci propone materiali e lavorazioni industriali sempre più sofisticati?In alcune realtà, è la carenza di alternative ad imporre l’uso della terra cruda come materiale da costruzione. Per progettisti e utenti ne scaturisce una responsabilità di utilizzare al meglio le risorse disponibili e migliorare le tecniche esistenti per aumentare sicurezza, prestazioni climatiche e qualità spaziale.Con la migliore conoscenza del materiale e delle possibilità d’impiego che offre, notevolmente aumentata negli ultimi anni grazie a ricerche e sperimentazioni specifiche, questo materiale si sta imponendo sempre di più anche nei paesi più industrializzati, non ultimo per via delle sue favorevoli prestazioni ambientali.Quali possibilità tecniche, costruttive ed espressive abbiamo e come possiamo generare architetture e trasformazioni spaziali appropriate in contesti culturali, geografici e socioeconomici molti diversi in Asia, Africa, Europa e America Latina? Ne discutono Raquel Barrionuevo, Anna Paola Conti, Luis Jimenez, Aldo Mantovani, Gernot Minke, Stefan Pollak, Eike Roswag, Julio Vargas Neuman, Andrea Vidotto, Claudia Walker e Michele Zampilli
Geometrical indeterminacy as a way to structural and architectural performance
No full textStructural systems with complex geometries are generally applied to very prestigious works of architecture and realized with sophisticated technologies.
The design process presented here aimed at investigating the possibility of building geometrically complex architecture using simple techniques and very cheap materials, yet achieving a meaningful structural and architectural performance.
Within an experimental workshop a team of 5 students supervised by the 2 authors built a real scale artefact, a temporary multi-religious pavilion with a tensile roof made of recycled cardboard
A counting proof of the Graham-Pollak Theorem
No full textWe give a counting based proof of the Graham-Pollak Theorem. (C) 2013 Published by Elsevier B.V
From Eggs to the Stars
No full textJane Pollak is a Westport, Connecticut, artist who started her career as a high school art teacher. She has now branched out into public speaking, is the author of two books, and embraces the life of entrepreneur as a sole proprietor of her rapidly expanding business of decorating eggs. For Jane, her life path has been one of hope and unexpected personal and business achievements.</jats:p
From Eggs to the Stars
No full textInterview of artist Jane Pollak by Shawn Blau and Laurence Weinstein.
Jane Pollak is a Westport, Connecticut, artist who started her career as a high school art teacher. She has now branched out into public speaking, is the author of two books, and embraces the life of entrepreneur as a sole proprietor of her rapidly expanding business of decorating eggs. For Jane, her life path has been one of hope and unexpected personal and business achievements
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