Macroscopic viscosity and the dielectric relaxation of some substituted benzenes

1976 ◽  
Vol 54 (9) ◽  
pp. 1418-1424 ◽  
Author(s):  
S. C. Srivastava ◽  
J. Crossley
Keyword(s):  
Relaxation Times ◽  
Dielectric Constants ◽  
The Other ◽  
Relaxation Processes ◽  
Substituted Benzenes ◽  
Microwave Dielectric ◽  
Paraffin Oil ◽  
Oil Mixtures ◽  
Insight Into ◽  
Dielectric Results

Microwave dielectric constants and losses, and viscosities (η) have been obtained for acetophenone, anisole, bromobenzene, and p-dimethoxybenzene in n-heptane, n-hexadecane, paraffin oil, and three n-heptane + paraffin oil mixtures between 15 and 60 °C. The dielectric results have been analyzed for mean relaxation times (τ0). Plots of ln τ0T against ln η for bromobenzene are compared with those for the other solutes in an attempt to determine the effect of contributions from intramolecular relaxation processes. The results suggest that measurements employing several solvents at one temperature provide a better insight into mechanisms of dipole reorientation than those with one solvent at several temperatures.

MOLECULAR MECHANISMS OF HIGHLY POLAR LIQUID CRYSTAL DIELECTRIC POLARIZATION

2021 ◽  
Vol 7 (1) ◽  
pp. 44-59
Author(s):  
Umardjon M. Mallaboev ◽  
Victor I. Novoselov ◽  
Olga S. Zaitseva
Keyword(s):  
Dielectric Constant ◽  
Liquid Crystal ◽  
Electric Field ◽  
Molecular Mechanisms ◽  
Relaxation Times ◽  
Dielectric Constants ◽  
Polar Liquid ◽  
Isotropic Phase ◽  
Relaxation Processes ◽  
Dielectric Polarization

This article studies the dielectric constants of the nematic ε, ε, and isotropic εis phases of a highly polar liquid crystal of 4-cyanophenyl ether of 4′-n-octyloxybenzoic acid in the megahertz range of electric field frequencies (105-108) Hz, as well as the anisotropy of the dielectric constant Δε = ε − ε. The authors have revealed the relaxation processes and mechanisms responsible for them. In addition, they calculated the relaxation times, dipole polarization activation energy, and deceleration parameters in the nematic phase. The design of a measuring cell is presented, which allows studying the dielectric constant of the liquid crystal at various orientations of the director (provided by the magnetic field) relative to an alternating electric field with small volumes of matter. The results show that the dispersion of the dielectric constant in the investigated frequency range of the electric field is characterized by two relaxation processes with τ ~3 ∙ 10−8 s and (τ)в ~ 1,5 ∙ 10−9 s. The dispersion mechanisms are due to the rotation of polar molecules about their short and long axes respectively. The dispersion of the dielectric constant corresponds to the spectrum of relaxation times. The dispersion mechanisms are associated with two relaxation processes: the precession of molecules along a cone within the spatial angle allowed by the value of the order parameter of the liquid crystal S < 1, and the rotation of molecules around the longitudinal axes. The relaxation times corresponding to these mechanisms are commensurate with each other. The dispersion of the dielectric constant in the isotropic phase is characterized by a relaxation process with τis ~ 6 ∙ 10−9 s. The dispersion mechanism is due to the rotation of molecules around short axes.

Dielectric studies. Part XVII. Relaxation processes and corresponding enthalpies of activation of some mono-substituted benzenes

1968 ◽  
Vol 46 (6) ◽  
pp. 841-845 ◽  
Author(s):  
J. Crossley ◽  
S. Walker
Keyword(s):  
Relaxation Times ◽  
Molecular Size ◽  
Relaxation Processes ◽  
Dielectric Studies ◽  
Molecular Reorientation ◽  
Substituted Benzenes ◽  
Microwave Frequencies ◽  
Dielectric Absorption ◽  
Expected Increase ◽  
Xylene Solution

The dielectric absorption at several microwave frequencies of liquid ethylbenzene, isopropylbenzene, and phenyltrimethylsilane at 15, 37.5, and 50 °C and cyclohexane solutions of t-butylbenzene and benzotrichloride at 15, 37.5, 45, and 50 °C has been examined. Benzotrichloride has also been studied in cyclohexane and p-xylene solution at 25 °C. Only molecular reorientation can be detected for benzotrichloride, whereas the remainder are all characterized by an absorption that may be analyzed into two relaxation times, one associated with molecular reorientation (τ1) and a shorter relaxation time (τ2) which appears to be attributable to an intermolecular process. The enthalpies of activation of the τ1 process show the expected increase with increasing molecular size, while no temperature dependence is detectable for the shorter relaxation process.

Dielectric Relaxation and Intramolecular Rotation in Aliphatic Ketones

1973 ◽  
Vol 51 (16) ◽  
pp. 2671-2675 ◽  
Author(s):  
John Crossley
Keyword(s):  
Dielectric Relaxation ◽  
Relaxation Times ◽  
Dielectric Constants ◽  
Aromatic Ketones ◽  
Paraffin Oil ◽  
Aliphatic Ketones ◽  
Intramolecular Rotation ◽  
Static Dielectric Constants ◽  
Viscosity Dependence

Dielectric constants and losses have been obtained for a number of aliphatic and aromatic ketones in cycloexane, n-hexadecane, decalin and paraffin oil – cyclohexane mixtures at up to ten frequencies between 1 and 145 GHz at 25 °C. Static dielectric constants have also been measured at 2 MHz. The results for each system have been analyzed in terms of a Cole–Cole distribution. The relaxation times and their viscosity dependence are discussed in terms of dipole reorientation by intramolecular and whole molecule rotations.

A Bird in the Hand Isn’t Good for Long

2018 ◽  
Vol 65 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Stefan Scherbaum ◽  
Simon Frisch ◽  
Maja Dshemuchadse
Keyword(s):  
Decision Making ◽  
Cognitive Control ◽  
The Other ◽  
Decision Task ◽  
Short Term ◽  
Additional Time ◽  
Control Processes ◽  
Folk Wisdom ◽  
Study Participants ◽  
Insight Into

Abstract. Folk wisdom tells us that additional time to make a decision helps us to refrain from the first impulse to take the bird in the hand. However, the question why the time to decide plays an important role is still unanswered. Here we distinguish two explanations, one based on a bias in value accumulation that has to be overcome with time, the other based on cognitive control processes that need time to set in. In an intertemporal decision task, we use mouse tracking to study participants’ responses to options’ values and delays which were presented sequentially. We find that the information about options’ delays does indeed lead to an immediate bias that is controlled afterwards, matching the prediction of control processes needed to counter initial impulses. Hence, by using a dynamic measure, we provide insight into the processes underlying short-term oriented choices in intertemporal decision making.

Correlational Methods for Analysis of Dance Movements

2011 ◽  
Vol 29 (supplement) ◽  
pp. 283-304 ◽  
Author(s):  
Timothy R. Brick ◽  
Steven M. Boker
Keyword(s):  
Motion Capture ◽  
Mirror Symmetry ◽  
Cross Correlation ◽  
The Other ◽  
Free Form ◽  
Motion Capture Data ◽  
Complex Interactions ◽  
Dance Movements ◽  
Time Lagged ◽  
Insight Into

Among the qualities that distinguish dance from other types of human behavior and interaction are the creation and breaking of synchrony and symmetry. The combination of symmetry and synchrony can provide complex interactions. For example, two dancers might make very different movements, slowing each time the other sped up: a mirror symmetry of velocity. Examining patterns of synchrony and symmetry can provide insight into both the artistic nature of the dance, and the nature of the perceptions and responses of the dancers. However, such complex symmetries are often difficult to quantify. This paper presents three methods – Generalized Local Linear Approximation, Time-lagged Autocorrelation, and Windowed Cross-correlation – for the exploration of symmetry and synchrony in motion-capture data as is it applied to dance and illustrate these with examples from a study of free-form dance. Combined, these techniques provide powerful tools for the examination of the structure of symmetry and synchrony in dance.

Marx, Silk Poems, and the Pretext of Qualities

2020 ◽  
Vol 151 (1) ◽  
pp. 96-126
Author(s):  
Kathryn Crim
Keyword(s):  
The Other ◽  
Use Value ◽  
Working Day ◽  
The One ◽  
Insight Into

Karl Marx’s comments on silk manufacture in “The Working Day” chapter of Capital, volume 1, demonstrate how “quality”—usually associated with “use value”—has been mobilized by capital to naturalize industrialized labor. Putting his insight into conversation with a recent multimedia poetic project, Jen Bervin’s Silk Poems (2016–17), this essay examines the homology between, on the one hand, poetry’s avowed task of fitting form to content and, on the other, the ideology of labor that fits specific bodies to certain materials and tasks.

Spiritualism in Raymond Carver’s Work

2015 ◽  
Vol 3 (1) ◽  
pp. 214
Author(s):  
Viola Kita
Keyword(s):  
The Other ◽  
Good Thing ◽  
Raymond Carver ◽  
The Bible ◽  
Other Hand ◽  
Christian Writer ◽  
Spiritual Reading ◽  
Insight Into

Raymond Carver’s work provides the opportunity for a spiritual reading. The article that offers the greatest insight into spirituality is William Stull’s “Beyond Hopelessville: Another Side of Raymond Carver.” In it we can notice the darkness which is dominant in Carver’s early works with the optimism that is an essential part of Carver’s work “Cathedral”. A careful reading of “A Small Good Thing” and “The Bath” can give the idea that they are based on the allegory of spiritual rebirth which can be interpreted as a “symbol of Resurrection”. Despite Stull’s insisting in Carver’s stories allusions based on the Bible, it cannot be proved that the writer has made use of Christian imagery. Therefore, it can be concluded that spirituality in Carver’s work is one of the most confusing topics so far in the literary world because on one hand literary critics find a lot of biblical elements and on the other hand Carver himself refuses to be analyzed as a Christian writer.

Intimacy as Transgression and the Problem of Freedom

2018 ◽  
Vol 1 (1) ◽  
pp. 18
Author(s):  
Kym Maclaren
Keyword(s):  
Intimate Relationships ◽  
Critical Analysis ◽  
Mutual Recognition ◽  
Public Institutions ◽  
The Other ◽  
Social Forces ◽  
Critical Insight ◽  
Insight Into ◽  
What Matters

“To consent to love or be loved,” said Merleau-Ponty, “is to consent also to influence someone else, to decide to a certain extent on behalf of the other.” This essay explicates that idea through a meditation on intimacy. I propose, first, that, on Merleau-Ponty’s account, we are always transgressing into each other’s experience, whether we are strangers or familiars; I call this “ontological intimacy.” Concrete experiences of intimacy are based upon this ontological intimacy, and can take place at two levels: (1) at-this-moment (such that we can experience intimacy even with strangers, by sharing a momentary but extra-ordinary mutual recognition) and (2) in shared interpersonal institutions, or habitual, enduring, and co-enacted visions of who we are, how to live, and what matters. Through particular examples of dynamics within these layers of intimacy (drawing upon work by Berne and by Russon), I claim that we are always, inevitably, imposing an “unfreedom” upon our intimate others. Freedom, then, can only develop from within and by virtue of this “unfreedom.” Thus, what distinguishes empowering or emancipating relationships from oppressive ones is not the removal of transgressive normative social forces; it is rather the particular character of those transgressive forces. Some transgressions upon others’ experience—some forms of “unfreedom”—will tend to promote freedom; others will tend to hinder it. This amounts to a call for promoting agency and freedom not only through critical analysis of public institutions, practices and discourses, but also through critical insight into and transformation of our most private and intimate relationships.

Basic Concepts and Definitions of Allergology

2019 ◽  
Author(s):  
Zoran Vrucinic
Keyword(s):  
Immune Reaction ◽  
The Body ◽  
The Other ◽  
Specific Response ◽  
Other Hand ◽  
Medical Vocabulary ◽  
The Future ◽  
Basic Concepts ◽  
Basic Insight ◽  
Insight Into

The future of medicine belongs to immunology and alergology. I tried to not be too wide in description, but on the other hand to mention the most important concepts of alergology to make access to these diseases more understandable, logical and more useful for our patients, that without complex pathophysiology and mechanism of immune reaction,we gain some basic insight into immunological principles. The name allergy to medicine was introduced by Pirquet in 1906, and is of Greek origin (allos-other + ergon-act; different reaction), essentially representing the reaction of an organism to a substance that has already been in contact with it, and manifested as a specific response thatmanifests as either a heightened reaction, a hypersensitivity, or as a reduced reaction immunity. Synonyms for hypersensitivity are: altered reactivity, reaction, hypersensitivity. The word sensitization comes from the Latin (sensibilitas, atis, f.), which means sensibility,sensitivity, and has retained that meaning in medical vocabulary, while in immunology and allergology this term implies the creation of hypersensitivity to an antigen. Antigen comes from the Greek words, anti-anti + genos-genus, the opposite, anti-substance substance that causes the body to produce antibodies.

scholarly journals Customisation and Desirable Characteristics of a Standard Method of Measurement for Building Works in Ghana

2012 ◽  
Vol 8 (2) ◽  
pp. 30-40 ◽  
Author(s):  
Gabriel Nani ◽  
Peter Edwards ◽  
Theophilus Adjei-Kumi ◽  
Edward Badu ◽  
Peter Amoah
Keyword(s):  
Construction Industry ◽  
Standard Method ◽  
The Other ◽  
Opinion Survey ◽  
British Standard ◽  
Industry Practice ◽  
Precision Industry ◽  
Method Of Measurement ◽  
Insight Into ◽  
Methods Of Measurement

This paper reports a study that identified andcategorised the modifications to the 5thEdition of the British Standard Method ofMeasurement (SMM5) of building works inGhana. Typical modifications involved ‘costinsignificant items’, ‘minor labour items’,‘custom units of measurement’, ‘methodrelated items’, ‘combinable items’,‘subordinate items’, and ‘items of minorinformative impact’. It was also observed thatthe desirable characteristics/ qualities ofstandard methods of measurement (SMM) ofbuilding work were noteworthy, since theyprovide insight into the nature of a SMMrequired for the construction industry inGhana.The research reviewed available literature,various SMMs and bills of quantities (BQs).The relevance of the modifications andSMM characteristics identified wasconfirmed by a survey of the opinions ofprofessional quantity surveyors conductedthrough a carefully designed questionnaire.Inferences from the opinion survey formedthe basis for grouping both SMMmodifications found and the desired qualitiesof a SMM for Ghana.Survey respondents confirmed all theidentified modifications to the British SMM,except for the elimination of items of minorinformative impact. It was held that allinformation was relevant in measurement.Desirable characteristics of a SMM were ratedin decreasing order of relevance as: easylocation of items; cost significance; simplicity;thoroughness; ease of cost analysis; goodpractice; conciseness; adoptability; precision;industry practice; stakeholders’ opinion;custom classification; regional relevance; andinclusion of jargon. It was noted that therelevance of these characteristics may varyform one region to the other as a result oftechnological, cultural and legal differences.However, the desired SMM characteristicswere recommended as fundamental indeveloping an appropriate SMM for Ghana.

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