Final Testimony on LR 141: Status of Nebraska Forest Service

Good morning, Chairman Wehrbein and members of the Appropriations Committee. I am John Owens, and I serve as Vice - President and Vice Chancellor of the Institute of Agriculture and Natural Resources at the University of Nebraska. Thank you for allowing me the opportunity to speak with you regarding Legislative Resolution 141 on the Nebraska Forest Service.

Molecular modeling of EPON 862-DETDA polymer

EPON 862 is an epoxy resin which is cured with the hardening agent DETDA to form a crosslinked epoxy polymer and is used as a component in modern aircraft structures. These crosslinked polymers are often exposed to prolonged periods of temperatures below glass transition range which cause physical aging to occur. Because physical aging can compromise the performance of epoxies and their composites and because experimental techniques cannot provide all of the necessary physical insight that is needed to fully understand physical aging, efficient computational approaches to predict the effects of physical aging on thermo-mechanical properties are needed. In this study, Molecular Dynamics and Molecular Minimization simulations are being used to establish well-equilibrated, validated molecular models of the EPON 862-DETDA epoxy system with a range of crosslink densities using a united-atom force field. These simulations are subsequently used to predict the glass transition temperature, thermal expansion coefficients, and elastic properties of each of the crosslinked systems for validation of the modeling techniques. The results indicate that glass transition temperature and elastic properties increase with increasing levels of crosslink density and the thermal expansion coefficient decreases with crosslink density, both above and below the glass transition temperature. The results also indicate that there may be an upper limit to crosslink density that can be realistically achieved in epoxy systems. After evaluation of the thermo-mechanical properties, a method is developed to efficiently establish molecular models of epoxy resins that represent the corresponding real molecular structure at specific aging times. Although this approach does not model the physical aging process, it is useful in establishing a molecular model that resembles the physically-aged state for further use in predicting thermo-mechanical properties as a function of aging time. An equation has been predicted based on the results which directly correlate aging time to aged volume of the molecular model. This equation can be helpful for modelers who want to study properties of epoxy resins at different levels of aging but have little information about volume shrinkage occurring during physical aging.

Experimental study of physical aging effects on properties of EPON 862-DETDA

Epoxies find variety of applications and during these applications they get exposed to different conditions like elevated temperatures, hydrothermal, chemical, etc. It has been observed that properties of epoxies do get affected substantially if exposed to these conditions for extended period of time and because of the variety of applications, researchers found it necessary to study their effects on the thermal, mechanical, physical and chemical properties. However in this report the focus is on studying effects of physical aging on mechanical properties of EPON 862 with DETDA as its curing agent, where physical aging is aging is the condition which occurs due to exposure to elevated temperatures. A fair amount of computational work has been performed on EPON 862- DETDA to study the effects of physical aging, however very little known work has been done experimentally to study these effects. Young’s modulus, hardness, failure strength, strain to failure, density and glass transition are the properties which have been obtained using various experimental methods - tensile testing, nanoindentation and differential scanning calorimetry. Experimental work on other epoxies have shown no increase or very slight increase in the Young’s modulus and hardness with increased aging time, also decrease in failure strength and strain to failure and through this work on EPON 862- DETDA we can observe similar trends.

Ms. hebr. oct. 141 - Shaʹare tsedeḳ

Vorbesitzer: Abraham Merzbacher

Ms. Barth. 141 - Apologetica. De contractibus. Bartolus de Saxoferrato

Vorbesitzer: Johannes Oppeler de Butzbach; Bartholomaeusstift Frankfurt am Main

Ms. lat. qu. 141 - Peul de Liptako. Vocabulaires recueilli à Dori. Vocabulaire des langues parlées dans le Cercle de Dori

Alte Signatur: Wq 535; Akzessionsnummer: 61727710

Ms. Praed. 141 - Casus summarii super Decretales

Vorbesitzer: Heinrich Brinzel (Brunsel); Johannes Usungen; Johannes Styrne; Dominikanerkloster Frankfurt am Main

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 862 - Wiederaufnahme des Kontakts nach langer Schreibpause

u.a. Heinrich von Lowtzow;

Na 50 Nachlass Arthur Schopenhauer - 'Schopenhauer-Archiv', 141 - Darstellung des hohen Stellenwerts Schopenhauers für die Philosophie

u.a.: Pantheismus; Übersendung "nassauischer Programme"; Kritik an so genannte Kathederphilosophen; Julius Frauenstädt;

Ms.Ff.F.Stoltze 3. 141 - Brief von Karl Friedrich Holbach an Félicie Louise Schalck de la Faverie

Ernst Schalck soll aus dem Nassauischen zurückgeholt werden, da er dort wegen des preußischen Urteils gegen die Latern-Redakteure in Verhaftungsgefahr schwebt

Na 1 Nachlass Max Horkheimer, 674 - Forschungsprojekte über Antisemitismus, Vorurteil, Autorität: Einzeluntersuchungen (p. IX 141.1-24- IX 142.1-6)

Bettelheim, Bruno; Janowitz, Morris: "A Study on Anxiety and Social Aggression Among Different Groups of War Veterans", 1945-1947; Über die Anfälligkeit der Veteranen für antisemitische Propaganda, Typoskript, englisch, 1 Blatt; "Preliminary Study on the Evaluation of Intolerance Propaganda". Typoskript, 29 Blatt; "Isolationg the Patterns of Intolerance". Typoskript, 30 Blatt; "Distribution of Ethic Intolerance". Typsokript, 18 Blatt; "The Social Characteristics of the Intolerant". Typoskript, 22 Blatt; "Addendum to Social Characteristics of the Intolerant". Typoskript, 16 Blatt; "Impact of War Experiences". Typoskript, 26 Blatt; "Pattern on Sterepotypes". Typoskript, 14 Blatt; "Appendix No. 1: Schedule of Questions Employed in Interview". Typoskript, 6 Blatt; "Appendix No. 2: The Verteran´s Comment on the Interview Situation". Typoskript, 7 Blatt; "Preliminary Report of the Evaluation of Tolerance Propaganda". Typoskript, 19 Blatt; Einleitung zur Beschreibung des Forschungsprojekts, Typoskript, englisch, 1 Blatt; "Instructions for Interviewers". Typoskript, 2 Blat; "Questionaire". Typoskrip, 10 Blatt; "Prupose of the Investigation". Typoskript, 4 Blatt; "Schedule for Interviewers". Typoskript, 6 Blatt; "Appendix: Chicago Veterans Project". Typoskript, 3 Blatt; Memodanden zu Sitzungen mit Bruno Bettelheim, Edward Shils und Theodor W. Adorno; Memorandum 03.04.1945, Typoskript, 2 Blatt; Memorandum 15.03.1945; a) Typoskript, 3 Blatt; b) Typoskript, 4 Blatt; Memorandum 07.03.1945; a) Typoskript, 5 Blatt; b) Typoskript, 6 Blatt; University of Chicago: 1 Brief an Max Horkheimer, Chicago, 29.10.1945; University of Chicago, 1 Brief an Edward Shils undBruno Bettelheim, Chicago, 05.07.1945; Fine, Benjamin: "For Education against Intolerance and Prejudice"; Sonderdruck aus: The Menorah Journal, 1944, Vol. XXXII, No. 2, S. 161-180; Drucksachen, Materialien, 10 Blatt; Ackerman, Nathan W.: zum 'Psychoanalyst Project', 1945-1946; "Towards a Dynamic definition of Anti-Semitism". Typoskript, 13 Blatt; "The Use of Psychoanalytic Case Histories for the Study of Anti-Semitism". Typoskript, 14 Blatt; "Case Material Summary", Tabelle, 5 Blatt; "From for the Collection of Clinical Data on Anti-Minority and Anti-Semitic Attitudes". Als Typoskript vervielfältigt, 5 Blatt; "Case 2". Typoskript, 5 Blatt; "Case 24". Typoskript, 8 Blatt;

Ms. lat. oct. 141 - In Thomae de Aquino Summam theologiae, P. I (Qu. 1 - 64)

Bei der Foliierung wurde ein Blatt übergangen, jetzt foliiert als 134a, die Blattzählung 105 wurde nicht vergeben.