Latex Maturation Studies by Low Angle Light Scattering Photometry

1973 ◽  
Vol 46 (2) ◽  
pp. 464-469 ◽  
Author(s):  
M. E. Myers ◽  
A. M. Wims ◽  
W. R. Lee
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Optimum Process ◽  
Basic Information ◽  
Size Change ◽  
Physical Chemical ◽  
Processing Variables ◽  
Volume Swelling ◽  
The Individual ◽  
The Relationship

Abstract Basic information on the relationship between processing variables and the physical chemical changes occurring during the “precure” of latex blends is required for optimum process control. To obtain this type of information, the particle size and particle size distribution of a latex blend undergoing a maturation or precure treatment were monitored by low angle light scattering techniques. The absence of any measurable particle size change during precure indicates that the process is simply an initiation of crosslinking within the individual latex particles which is caused by penetration of molecular sulfur and other activators and accelerators. Volume swelling measurements were performed at intervals to determine the degree of precure attained by the blend.

Particle Size Characterisation of Tin Oxide (SnO2) Precipitated by Various Techniques: Consistency of Data

2007 ◽  
Vol 561-565 ◽  
pp. 2155-2158
Author(s):  
H. Taib ◽  
Charles C. Sorrell
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Tin Oxide ◽  
Spherical Shape ◽  
Particle Sizes ◽  
Size Distributions ◽  
Particle Size Distributions ◽  
Oxide Powders ◽  
Spherical Agglomerates ◽  
The Individual

The particle size distributions of tin oxide powders produced from the calcining of precipitated tin oxalate were determined by four methods, these being two static and two dynamic light scattering techniques. Although the individual particle sizes were ~ 75 nm, all of the powders were heavily agglomerated as plates. The non-spherical shape resulted in the following interpretational problems: • None of the measurements was in agreement with any others. • There were very significant disagreements between the two light scattering methods. • The particle size distributions were multimodal. • The main peaks in the distribution curves, which were used to calculate the averages and standard deviations, were not Gaussian. The main uncertainty with these data is associated with the non-spherical agglomerates, which result in the multimodal size distributions. These probably were caused by variable-sized but large platy agglomerates.

scholarly journals Quality Identification of Sauce-Flavor Liquor Based on the Tyndall Phenomenon

2021 ◽  
Vol 12 (1) ◽  
pp. 53
Author(s):  
Huizi Liu ◽  
Xuezhou Yang ◽  
Xiaofeng Su ◽  
Shuzhi Li ◽  
Qiyuan Du ◽  
...  
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Storage Time ◽  
Time Cost ◽  
Brewing Process ◽  
Size Uniformity ◽  
Important Quality ◽  
The Relationship ◽  
Long Storage

There is an obvious colloid state in sauce-flavor liquor due to its unique brewing process and long storage time, which is an important quality feature of sauce-flavor. Aiming at the problems of time, cost, and the strong professionalism of the traditional quality identification method, we proposed a method to identify the quality of sauce-flavored liquor based on the Tyndall phenomenon. The influence of different wavelengths of light on the light scattering in liquor was explored, and it was concluded that the ultraviolet and blue light bands have a certain efficiency in the identification of liquor. Additionally, we analyzed the relationship between the particle size uniformity of liquor colloids and liquor quality according to the Tyndall phenomenon. We found that higher quality liquor has a brighter and lighter Tyndall path and a smaller light flooding angle due to the uniformity of the particles in it. This method can be used to achieve qualitative identification and is suitable for the identification of sauce-flavored liquor.

Angle-dependent effects in Dynamic Light Scattering measurements of polydisperse particles

2021 ◽  
Author(s):  
Lin Jin ◽  
Curtis W Jarand ◽  
Mark L Brader ◽  
Wayne F Reed
Keyword(s):  
Particle Size ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Laser Wavelength ◽  
Recent Emergence ◽  
Large Particles ◽  
Average Diffusion ◽  
Biological Polymers ◽  
Average Size ◽  
The Relationship

Abstract Dynamic light scattering (DLS) is widely used for analyzing biological polymers and colloids. Its application to nanoparticles in medicine is becoming increasingly important with the recent emergence of prominent lipid nanoparticle-(LNP)based products, such as the SARS-CoV-2 vaccines from Pfizer, Inc.-BioNTech (BNT162b2) and Moderna, Inc. (mRNA-1273). DLS plays an important role in the characterization and quality control of nanoparticle-based therapeutics and vaccines. However, most DLS instruments have a single detection angle ,and the amplitude of the scattering vector, q, varies among them according to the relationship q=(n/sin(/2) where 0 is the laser wavelength. Results for identical, polydisperse samples among instruments of varying q yield different hydrodynamic diameters, because, as particles become larger they scatter less light at higher angles, so that higher-q instruments will under-sample large particles in polydisperse populations, and report higher z-average diffusion coefficients, and hence smaller effective hydrodynamic diameters than lower-q instruments. As particle size reaches the Mie regime the scattering envelope manifests angular maxima and minima, and the monotonic decrease of average size versus q is lost. This work examines results for different q-value instruments, using mixtures of monodisperse latex sphere standards, for which experimental measurements agree well with computations, and also polydisperse solutions of LNP, for which results follow expected trends. Mie effects on broad unimodal populations are also considered. There is no way to predict results between two instruments with different q for samples of unknown particle size distributions.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

Investigating the Relationship Between Self-Esteem and Stigma Among Young Adults With History of Suicide Attempts

Crisis ◽  
2016 ◽  
Vol 37 (4) ◽  
pp. 265-270 ◽  
Author(s):  
Meshan Lehmann ◽  
Matthew R. Hilimire ◽  
Lawrence H. Yang ◽  
Bruce G. Link ◽  
Jordan E. DeVylder
Keyword(s):  
Young Adults ◽  
Suicide Attempts ◽  
Self Esteem ◽  
High Risk Population ◽  
High Functioning ◽  
People With Mental Illness ◽  
History Of ◽  
The Individual ◽  
The Impact ◽  
The Relationship

Abstract. Background: Self-esteem is a major contributor to risk for repeated suicide attempts. Prior research has shown that awareness of stigma is associated with reduced self-esteem among people with mental illness. No prior studies have examined the association between self-esteem and stereotype awareness among individuals with past suicide attempts. Aims: To understand the relationship between stereotype awareness and self-esteem among young adults who have and have not attempted suicide. Method: Computerized surveys were administered to college students (N = 637). Linear regression analyses were used to test associations between self-esteem and stereotype awareness, attempt history, and their interaction. Results: There was a significant stereotype awareness by attempt interaction (β = –.74, p = .006) in the regression analysis. The interaction was explained by a stronger negative association between stereotype awareness and self-esteem among individuals with past suicide attempts (β = –.50, p = .013) compared with those without attempts (β = –.09, p = .037). Conclusion: Stigma is associated with lower self-esteem within this high-functioning sample of young adults with histories of suicide attempts. Alleviating the impact of stigma at the individual (clinical) or community (public health) levels may improve self-esteem among this high-risk population, which could potentially influence subsequent suicide risk.

Virginia Woolf and Being-in-the-world

2017 ◽  
Author(s):  
Emma Simone
Keyword(s):  
Virginia Woolf ◽  
Historical Context ◽  
The Political ◽  
Cartesian Dualism ◽  
Self And Other ◽  
The World ◽  
Binary Oppositions ◽  
The Individual ◽  
The Relationship ◽  
Existential Perspective

Virginia Woolf and Being-in-the-world: A Heideggerian Study explores Woolf’s treatment of the relationship between self and world from a phenomenological-existential perspective. This study presents a timely and compelling interpretation of Virginia Woolf’s textual treatment of the relationship between self and world from the perspective of the philosophy of Martin Heidegger. Drawing on Woolf’s novels, essays, reviews, letters, diary entries, short stories, and memoirs, the book explores the political and the ontological, as the individual’s connection to the world comes to be defined by an involvement and engagement that is always already situated within a particular physical, societal, and historical context. Emma Simone argues that at the heart of what it means to be an individual making his or her way in the world, the perspectives of Woolf and Heidegger are founded upon certain shared concerns, including the sustained critique of Cartesian dualism, particularly the resultant binary oppositions of subject and object, and self and Other; the understanding that the individual is a temporal being; an emphasis upon intersubjective relations insofar as Being-in-the-world is defined by Being-with-Others; and a consistent emphasis upon average everydayness as both determinative and representative of the individual’s relationship to and with the world.

The importance and significance of gene polymorphisms in preeclampsia

2016 ◽  
pp. 45-49
Author(s):  
P.N. Veropotvelyan ◽  
◽  
I.S. Tsehmistrenko ◽  
N.P. Veropotvelyan ◽  
N.S. Rusak ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Systematic Review ◽  
Early Diagnosis ◽  
Gene Polymorphisms ◽  
Individual Risk ◽  
Extended Study ◽  
Stress Genes ◽  
Detoxification System ◽  
The Individual ◽  
The Relationship

Was to conduct a systematic review of data on the relationship between polymorphisms genes of detoxification system and development of preeclampsia (РЕ). Рresents the main genes of detoxification system (GSTPI, GSTМI, GSTТI, GРХI, ЕРНХI, SOD-2, SOD-3, CYPIAL, MTHЕR, MTR) and their functions. Of interest is the possibility of calculating the individual risk of PE based on the results about the presence of a combination of different polymorphisms in the genotype of the female. Question about early diagnosis of РЕ remains controversial and not fully understood. It is necessary to conduct further in-depth, extended study of this problem. Key words: preeclampsia, oxidative stress, genes of the detoxification system.

Co-creating the Psychological “White Picket Fence”: Three Gay Couples’ Relationship Reconfiguration

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Prevan Moodley ◽  
Francois Rabie
Keyword(s):  
Grounded Theory ◽  
South African ◽  
Gay Couples ◽  
Core Category ◽  
Picket Fence ◽  
Open Relationship ◽  
The Individual ◽  
The Relationship ◽  
Porous Boundaries

Many gay couples engage in nonmonogamous relationships. Ideas about nonmonogamy have historically been theorised as individual pathology and indicating relational distress. Unlike mixed-sex couples, boundaries for gay couples are often not determined by sexual exclusivity. These relationships are built along a continuum of open and closed, and sexual exclusivity agreements are not restricted to binaries, thus requiring innovation and re-evaluation. Three white South African gay couples were each jointly interviewed about their open relationship, specifically about how this is negotiated. In contrast to research that uses the individual to investigate this topic, this study recruited dyads. The couples recalled the initial endorsement of heteronormative romantic constructions, after which they shifted to psychological restructuring. The dyad, domesticated through the stock image of a white picket fence, moved to a renewed arrangement, protected by “rules” and imperatives. Abbreviated grounded theory strategies led to a core category, “co-creating porous boundaries”, and two themes. First, the couple jointly made heteronormative ideals porous and, second, they reconfigured the relationship through dyadic protection. The overall relationship ideology associated with the white picket fence remained intact despite the micro-innovations through which the original heteronormative patterning was reconfigured.

The (Mis) Education of Immigrant Children in Today’s America

2019 ◽  
Vol 5 (2) ◽  
pp. 32
Author(s):  
Gabriela E. Gui
Keyword(s):  
General Education ◽  
Immigrant Students ◽  
Geographical Location ◽  
Personal Characteristics ◽  
Immigrant Children ◽  
Playing Field ◽  
Survey Interviews ◽  
The Individual ◽  
The Relationship ◽  
General Education Classrooms

In today’s America, not every child starts on a level playing field, and very few children move ahead based solely on hard work or talent. Generational poverty and a lack of cultural capital hold many students back, robbing them of the opportunity to move up professionally and socially. Children of immigrants are especially at-risk because, in addition to facing poverty, race, geographical location or economic disadvantages, they are also confronted with failure due to their limited or non-existent English proficiency. This study focuses on the degree to which teachers in a mid-sized urban school district take into consideration the individual needs of immigrant children in the process of their education. The study also examines the preparation teachers have had to equip them with knowledge of best practices in teaching immigrant children, and the relationship between teachers’ practices, beliefs, and their demographic and personal characteristics (age, gender, years of experience, level of education, etc.). Quantitative data was collected via a survey. Interviews with teachers and one central office administrator provided data for the qualitative section of the study. The findings revealed that teachers, in general, appeared to lack knowledge of specific policies for mainstreaming immigrant students into general education classrooms; their use of effective teaching practices for working with immigrant children were limited; and most of the teachers had not participated actively in professional development that focused on teaching immigrant children.

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