Relationship between Molecular Orientation Relaxation during Physical Aging and Heat Resistance of Polystyrene Injection Moldings

2021 ◽  
Vol 36 (5) ◽  
pp. 577-585
Author(s):  
K. Tao ◽  
K. Yamada ◽  
S. Higashi ◽  
K. Kago ◽  
H. Takeshita ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Heat Resistance ◽  
Molecular Orientation ◽  
Physical Aging ◽  
Core Layer ◽  
Heating Process ◽  
The Core ◽  
Heat Distortion Temperature ◽  
Orientation Relaxation ◽  
The Relationship

Abstract This work examined the relationship between changes in molecular orientation and the heat resistance (heat distortion temperature) of polystyrene injection moldings following heat treatment below the glass transition temperature. Molecular orientation around the core layer of the injection moldings was found to be relaxed by the heat treatment. Also, in the untreated specimen, the molecular orientation around the core layer was relaxed from 60°C during the heating process. Since loss tangent (tanδ) also increased from 60°C during the heating process in the untreated specimen, it was considered that the increase in tanδ occurred with the molecular motion due to the relaxation of molecular orientation from 60°C. After the heat treatment, because of the relaxation of molecular orientation around the core layer by the heat treatment, the relaxation of molecular orientation from 60 °C did not occur during the subsequent heating process, and the tanδ of the polymer between 60 and 90 °C was decreased. Because this decrease in the tanδ over this temperature range improved the heat resistance of the material, the enhanced heat resistance by the heat treatment was attributed to the suppression of the relaxation of molecular orientation from 60°C during the heating process. Furthermore, relaxation of molecular orientation and enthalpy relaxation were related to improvement in the heat resistance.

scholarly journals Systematic Assessment of Nonproteolytic Clostridium botulinum Spores for Heat Resistance

2016 ◽  
Vol 82 (19) ◽  
pp. 6019-6029 ◽  
Author(s):  
Ewelina Wachnicka ◽  
Sandra C. Stringer ◽  
Gary C. Barker ◽  
Michael W. Peck
Keyword(s):  
Heat Treatment ◽  
Heat Resistance ◽  
Heating Process ◽  
Quantitative Microbial Risk Assessment ◽  
Spore Concentration ◽  
Data Set ◽  
Content Type ◽  
Microbial Risk Assessment ◽  
Systematic Assessment ◽  
Value Determination

ABSTRACTHeat treatment is an important controlling factor that, in combination with other hurdles (e.g., pH, aw), is used to reduce numbers and prevent the growth of and associated neurotoxin formation by nonproteolyticC. botulinumin chilled foods. It is generally agreed that a heating process that reduces the spore concentration by a factor of 106is an acceptable barrier in relation to this hazard. The purposes of the present study were to review the available data relating to heat resistance properties of nonproteolyticC. botulinumspores and to obtain an appropriate representation of parameter values suitable for use in quantitative microbial risk assessment. In total, 753Dvalues and 436zvalues were extracted from the literature and reveal significant differences in spore heat resistance properties, particularly those corresponding to recovery in the presence or absence of lysozyme. A total of 503Dand 338zvalues collected for heating temperatures at or below 83°C were used to obtain a probability distribution representing variability in spore heat resistance for strains recovered in media that did not contain lysozyme.IMPORTANCEIn total, 753Dvalues and 436zvalues extracted from literature sources reveal significant differences in spore heat resistance properties. On the basis of collected data, twozvalues have been identified,z= 7°C andz= 9°C, for spores recovered without and with lysozyme, respectively. The findings support the use of heat treatment at 90°C for 10 min to reduce the spore concentration by a factor of 106, providing that lysozyme is not present during recovery. This study indicates that greater heat treatment is required for food products containing lysozyme, and this might require consideration of alternative recommendation/guidance. In addition, the data set has been used to test hypotheses regarding the dependence of spore heat resistance on the toxin type and strain, on the heating technique used, and on the method ofDvalue determination used.

scholarly journals The Relationship between the Change in Dynamic Viscoelasticity by Heat Treatment and Heat Resistance in Polystyrene Moldings

2021 ◽  
Vol 70 (1) ◽  
pp. 11-16
Author(s):  
Kousaku TAO ◽  
Koji YAMADA ◽  
Seiji HIGASHI ◽  
Hiroki TAKESHITA ◽  
Katsuhisa TOKUMITSU
Keyword(s):  
Heat Treatment ◽  
Heat Resistance ◽  
Dynamic Viscoelasticity ◽  
The Relationship

Polarized microbeam FT-IR analysis of single fibers

1996 ◽  
Vol 54 ◽  
pp. 206-207
Author(s):  
Liling Cho ◽  
David L. Wetzel
Keyword(s):  
Molecular Orientation ◽  
Transition Point ◽  
Polymer Fibers ◽  
Single Fiber ◽  
Wire Grid ◽  
Polyester Fibers ◽  
Ft Ir ◽  
Ir Analysis ◽  
The Relationship ◽  
Wire Grid Polarizer

Polarized infrared microscopy has been used for forensic purposes to differentiate among polymer fibers. Dichroism can be used to compare and discriminate between different polyester fibers, including those composed of polyethylene terephthalate that are frequently encountered during criminal casework. In the fiber manufacturering process, fibers are drawn to develop molecular orientation and crystallinity. Macromolecular chains are oriented with respect to the long axis of the fiber. It is desirable to determine the relationship between the molecular orientation and stretching properties. This is particularly useful on a single fiber basis. Polarized spectroscopic differences observed from a single fiber are proposed to reveal the extent of molecular orientation within that single fiber. In the work presented, we compared the dichroic ratio between unstretched and stretched polyester fibers, and the transition point between the two forms of the same fiber. These techniques were applied to different polyester fibers. A fiber stretching device was fabricated for use on the instrument (IRμs, Spectra-Tech) stage. Tension was applied with a micrometer screw until a “neck” was produced in the stretched fiber. Spectra were obtained from an area of 24×48 μm. A wire-grid polarizer was used between the source and the sample.

In a word, I’ve been there

2019 ◽  
pp. 246-256
Author(s):  
A. K. Zholkovsky
Keyword(s):  
The State ◽  
Female Characters ◽  
Political Situation ◽  
The Core ◽  
The Relationship ◽  
Core Problem ◽  
Typical Solution

In his article, A. Zholkovsky discusses the contemporary detective mini-series Otlichnitsa [A Straight-A Student], which mentions O. Mandelstam’s poem for children A Galosh [Kalosha]: more than a fleeting mention, this poem prompts the characters and viewers alike to solve the mystery of its authorship. According to the show’s plot, the fact that Mandelstam penned the poem surfaces when one of the female characters confesses her involvement in his arrest. Examining this episode, Zholkovsky seeks structural parallels with the show in V. Aksyonov’s Overstocked Packaging Barrels [Zatovarennaya bochkotara] and even in B. Pasternak’s Doctor Zhivago [Doktor Zhivago]: in each of those, a member of the Soviet intelligentsia who has developed a real fascination with some unique but unattainable object is shocked to realize that the establishment have long enjoyed this exotic object without restrictions. We observe, therefore, a typical solution to the core problem of the Soviet, and more broadly, Russian cultural-political situation: the relationship between the intelligentsia and the state, and the resolution is not a confrontation, but reconciliation.

The relationship of magnates and the szlachta of the Great Principality/Grand Duchy of Lithuania with Russia in 1733

2020 ◽  
Author(s):  
А.В. Мацук
Keyword(s):  
Free Choice ◽  
Russian Empire ◽  
The Core ◽  
The Russian Empire ◽  
Grand Duchy Of Lithuania ◽  
Relationship Of ◽  
The Relationship ◽  
Grand Duchy

В статье исследуются события бескоролевья 1733 г. в Речи Посполитой. Согласно «трактату Левенвольде» компромиссным кандидатом на избрание монархом Речи Посполитой был португальский инфант дон Мануэль, которого предложила Австрия. Россия больше склонялась к кандидатуре «пяста». Россия оказалась не подготовленной к началу бескоролевья. Бывшие российские союзники магнаты ВКЛ рассорились с российским послом Фридрихом Казимиром Левенвольде и перешли на сторону Франции. В конце февраля 1733 г. в ВКЛ направили Юрия Ливена, который от имени российской царицы предложил поддержку в получении короны Михаилу Вишневецкому и Павлу Сангушке. Принятое на конвокационном сейме решение об избрании королем «пяста» и католика показало популярность Станислава Лещинского. В результате вслед за Австрией Россия поддержала кандидатом на корону Фридриха Августа. Магнаты ВКЛ до последнего оставались конкурентами о короне. Оппозиция Лещинскому объединилась под лозунгом защиты «вольного выбора» и поэтому в ней остались кандидаты «пясты», которые не могли уступить друг другу, и согласились на компромисс – кандидатуру Фридриха Августа. Для противодействия возможному избранию Лещинского Россия создала в ВКЛ новоградскую конфедерацию. Ее организатором стал новоградский воевода Николай Фаустин Радзивилл. Эта конфедерация становится основой Генеральной Варшавской конфедерации, которая 5 октября 1733 г. избирает королем саксонского курфюрста. The article examines the events of the «kingless» year of 1733 in the Polish-Lithuanian Commonwealth. According to the Levenwolde Treaties the compromise candidate for the Commonwealth’s throne was the Portuguese Infante Don Manuel, who’s candidacy was proposed by Austria. Russia, in turn, leaned towards the «pyasta» candidate. The Russian Empire was clearly unprepared for the start of the kingless period. Russia’s former allies – magnates of the Grand Duchy of Lithuania – came into conflict with the Russian ambassador Frederick Kazimir Levenwolde and sided with France. In late February of 1733, Empress Anna Ioanovna of Russia sent Yuri Liven to the Grand Duchy of Lithuania, who offered official support in the struggle for the crown to Mikhail Vishnevetsky and Pavel Sangushka. The electoral decision made at the Sejm proved the popularity of the «pyast» and Catholic candidates, specifically – Stanislaus Leschinsky. In turn, Russia – following Austria – showed its support for the candidacy of Frederick August. The magnates of the Grand Duchy of Lithuania remained in opposition in the crown issue until the very last. Opposition to Leschinsky was united under the motto of «free choice». For that reason, it was comprised of «pyasta» candidates, who were in a deadlock with one another, and were now ready for the compromise candidacy of Frederick Augustus. In order to counter the possible election of Leschinsky, Russia created the Novograd Confederation in the Grand Duchy of Lithuania. It was organized by the Novograd Voevoda Faustin Radzivill. This confederation became the core of the General Warsaw Confederation that – on October 5th 1733 – elected the Saxon King to the throne of the Polish-Lithuanian Commonwealth.

All Hail to the Archpriest

2019 ◽  
Author(s):  
Peter Lake ◽  
Michael Questier
Keyword(s):  
Seventeenth Century ◽  
Church And State ◽  
Good Deal ◽  
The Core ◽  
Public Argument ◽  
The Relationship ◽  
Public Politics

This volume revisits the debates and disputes known collectively in the literature on late sixteenth- and early seventeenth-century England as the ‘Archpriest Controversy’. We argue that this was an extraordinary instance of the conduct of contemporary public politics and that, in its apparent strangeness, it is in fact a guide to the ways in which contemporaries negotiated the unstable later Reformation settlement in England. The published texts which form the core of the arguments involved in this debate survive, as do several caches of manuscript material generated by the dispute. Together they tell us a good deal about the aspirations of the writers and the networks that they inhabited. They also allow us to retell the progress of the dispute both as a narrative and as an instance of contemporary public argument about topics such as the increasingly imminent royal succession, late Elizabethan puritanism, and the function of episcopacy. Our contention is that, if one takes this material seriously, it is very hard to sustain standard accounts of the accession of James VI in England as part of an almost seamless continuity of royal government, contextualized by a virtually untroubled and consensus-based Protestant account of the relationship between Church and State. Nor is it possible to maintain that by the end of Elizabeth’s reign the fraction of the national Church, separatist and otherwise, which regarded itself or was regarded by others as Catholic had been driven into irrelevance.

A realistic model for transverse shear stiffness prediction of composite corrugated-core sandwich structure with bonding effect

2021 ◽  
pp. 109963622199386
Author(s):  
Tianshu Wang ◽  
Licheng Guo
Keyword(s):  
Present Model ◽  
Shear Stiffness ◽  
Realistic Model ◽  
Torsional Stiffness ◽  
Fem Model ◽  
The Core ◽  
Bonding Effect ◽  
Stiffness Model ◽  
Bonding Area ◽  
The Relationship

In this paper, a shear stiffness model for corrugated-core sandwich structures is proposed. The bonding area is discussed independently. The core is thought to be hinged on the skins with torsional stiffness. The analytical model was verified by FEM solution. Compared with the previous studies, the new model can predict the valley point of the shear stiffness at which the relationship between the shear stiffness and the angle of the core changes from negative correlation to positive correlation. The valley point increases when the core becomes stronger. For the structure with a angle of the core smaller than counterpart for the valley point, the existing analytical formulations may significantly underestimate the shear stiffness of the structure with strong skins. The results obtained by some previous models may be only 10 persent of that of the present model, which is supported by the FEM model.

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