Microstructure of Unburned Clay and its Shrinkage during Drying

2016 ◽  
Vol 837 ◽  
pp. 109-112 ◽  
Author(s):  
Tereza Otcovska ◽  
Pavel Padevět
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Building Material ◽  
Basic Problem ◽  
Volume Changes ◽  
Material Characteristics ◽  
Increasing Demand ◽  
Building Practice ◽  
Civil Engineers

Unburned clay was used for the traditional engineering works for thousands years. Its qualities have not been too appreciated in the last few decades. Because of that, its material characteristics were never researched very rigorously. In last years, we could see increasing demand for use of this building material in building practice and research. The basic problem that should be mitigated by civil engineers handling unburned clay is its considerable shrinkage during drying. The degree of shrinkage depends on the amount of mixture water and on the amount and type of clay minerals. In the unburned clay, like in the cement, clay minerals play role of the binder. The problem is that clay minerals are causing volume changes. This paper is focused on the degree of shrinkage and its dependence on the species and quantity of clay mineral.

Dependence of Tensile Bending Strength of Rammed Earth on Used Clay Composition and Amount of Mixture Water

2017 ◽  
Vol 1144 ◽  
pp. 48-53
Author(s):  
Tereza Otcovska ◽  
Pavel Padevět
Keyword(s):  
Mechanical Properties ◽  
Clay Minerals ◽  
Bending Strength ◽  
Construction Material ◽  
Rammed Earth ◽  
Small Test ◽  
Proper Material ◽  
Traditional Construction ◽  
Building Practice

Clay is a traditional construction material which has got to background with introduction of modern materials to building practice. There is not proper material available for clay constructions design due to a lack of proper examination of its mechanical properties. This article focuses on tensile bending strength of rammed earth. The mechanical properties depend on the amount of mixture water and on the amount and type of clay minerals. The clay minerals play role of the binder similarly like a cement in concrete. This paper is focused on the tensile bending strength and its dependence on the composition and quantity of clay mineral and its dependence on the amount of mixture water. Five earth mixtures were tested. Mechanical properties were examined on small test bodies made of these mixtures. The mechanical properties of the five mixtures are compared at the end of the paper.

scholarly journals Titania-Clay Mineral Composites for Environmental Catalysis and Photocatalysis

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1087
Author(s):  
Ewa M. Serwicka
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Photocatalytic Performance ◽  
Functional Materials ◽  
Building Blocks ◽  
Titania Nanoparticles ◽  
Environmental Catalysis ◽  
Physical And Chemical ◽  
Rich History

The use of titania-based composite materials in the field of heterogeneous catalysis and photocatalysis has a long and rich history. Hybrid structures combining titania nanoparticles with clay minerals have been extensively investigated for nearly four decades. The attractiveness of clay minerals as components of functional materials stems primarily from their compositional versatility and the possibility of using silicate lamellae as prefabricated building blocks ready to be fitted into the desired nanoconstruction. This review focuses on the evolution over the years of synthetic strategies employed for the manufacturing of titania–clay mineral composites with particular attention to the role of the adopted preparative approach in shaping the physical and chemical characteristics of the materials and enabling, ultimately, tuning of their catalytic and/or photocatalytic performance.

scholarly journals DFT Study of Electronic Structure and Optical Properties of Kaolinite, Muscovite, and Montmorillonite

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 618
Author(s):  
Layla Shafei ◽  
Puja Adhikari ◽  
Wai-Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Electronic Structure ◽  
Hydrogen Bonds ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Bond Order ◽  
Deep Understanding ◽  
Pharmaceutical Applications ◽  
Structure Properties

Clay mineral materials have attracted attention due to their many properties and applications. The applications of clay minerals are closely linked to their structure and composition. In this paper, we studied the electronic structure properties of kaolinite, muscovite, and montmorillonite crystals, which are classified as clay minerals, by using DFT-based ab initio packages VASP and the OLCAO. The aim of this work is to have a deep understanding of clay mineral materials, including electronic structure, bond strength, mechanical properties, and optical properties. It is worth mentioning that understanding these properties may help continually result in new and innovative clay products in several applications, such as in pharmaceutical applications using kaolinite for their potential in cancer treatment, muscovite used as insulators in electrical appliances, and engineering applications that use montmorillonite as a sealant. In addition, our results show that the role played by hydrogen bonds in O-H bonds has an impact on the hydration in these crystals. Based on calculated total bond order density, it is concluded that kaolinite is slightly more cohesive than montmorillonite, which is consistent with the calculated mechanical properties.

Liver cell hydration and integrin signaling

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Michele Bonus ◽  
Dieter Häussinger ◽  
Holger Gohlke
Keyword(s):  
Cell Volume ◽  
Liver Cell ◽  
Cell Function ◽  
The Other ◽  
Signaling Cascades ◽  
Integrin Signaling ◽  
Volume Changes ◽  
The One ◽  
And Oxidative Stress

Abstract Liver cell hydration (cell volume) is dynamic and can change within minutes under the influence of hormones, nutrients, and oxidative stress. Such volume changes were identified as a novel and important modulator of cell function. It provides an early example for the interaction between a physical parameter (cell volume) on the one hand and metabolism, transport, and gene expression on the other. Such events involve mechanotransduction (osmosensing) which triggers signaling cascades towards liver function (osmosignaling). This article reviews our own work on this topic with emphasis on the role of β1 integrins as (osmo-)mechanosensors in the liver, but also on their role in bile acid signaling.

scholarly journals Investigating collaborative and mobility networks: reflections on the core missions of universities

2021 ◽  
Author(s):  
Zsolt Tibor Kosztyán ◽  
Beáta Fehérvölgyi ◽  
Tibor Csizmadia ◽  
Kinga Kerekes
Keyword(s):  
Social Progress ◽  
Industry Funding ◽  
Multilayer Network ◽  
The Core ◽  
Funding Agencies ◽  
Valid Assessment ◽  
Increasing Demand ◽  
Public Money ◽  
University Performance

AbstractGiven the significant role of universities in economic growth and social progress as well as the increasing demand for greater transparency regarding the use of public money, a valid assessment of university performance has become crucial for various stakeholders, including government, industry, funding agencies, and society at large. Contemporary assessments still focus solely on universities’ properties, thereby failing to capture their network relations. To overcome this limitation, this paper proposes a multilayer network-based method to measure the embeddedness of universities in collaboration and mobility networks. This method has several advantages: first, it is relevant for HEIs’ core missions, introducing a new dimension complementary to the existing rankings; second, it is size invariant; and last but not least, it is fully transparent. The proposed multilayer network approach enables the integration of further networks, which creates opportunities for a more comprehensive assessment of universities’ performance in achieving their core missions.

Herbs and phytogenic feed additives in poultry nutrition

2023 ◽  
Vol 77 (11) ◽  
pp. 6589-2023
Author(s):  
HALINA MAKAŁA
Keyword(s):  
Animal Welfare ◽  
Feed Additives ◽  
Poultry Meat ◽  
High Demand ◽  
Rearing Conditions ◽  
Poultry Nutrition ◽  
Increasing Demand ◽  
Herbal Mixtures

The aim of the study was to review the results of scientific research on the effect of herbs and phytogenic feed additives used in poultry nutrition on animal welfare, breeding conditions, and the quality of meat. The article explains the importance of feed additives used in poultry nutrition. It discusses the role of herbs and phytogenic feed additives in nutrition in the context of the increasing demand for and consumption of poultry meat. The article also analyzes the influence of herbs and phytogenic feed additives on animal welfare, rearing conditions, and meat quality. The results of research on the effect of herbs and phytogenic feed additives used in poultry nutrition are not unequivocal. In view of the high demand for poultry meat, there is need for continued research on the optimal composition of herbal mixtures in nutrition to obtain good breeding conditions and high quality meat.

Exploring the lived experience of endoscopy trainees and their perceptions of nurse endoscopists as trainers

2021 ◽  
Vol 19 (Sup8) ◽  
pp. S14-S21
Author(s):  
Leigh Donnelly ◽  
Alison Steven
Keyword(s):  
Lived Experience ◽  
Emotional Impact ◽  
Training Experience ◽  
Endoscopy Training ◽  
Constructive Feedback ◽  
Self Confidence ◽  
Therapeutic Procedures ◽  
Emerging Themes ◽  
Increasing Demand

Background UK endoscopy services face considerable workforce pressures from an increasing demand for procedures. To meet this need, health services have introduced the role of nurse endoscopist (also known as clinical, non-medical or non-physician endoscopist). These roles have grown and developed to include performing many complex diagnostic and therapeutic procedures, as well as the provision of endoscopy training. Aims This study examines the lived experiences of (nurse and medical) endoscopy trainees, especially regarding being trained by nurse endoscopists. Methods The study employed interpretive phenomenological analysis (IPA). Data were collected through semi-structured in-depth interviews of 10 participants, who were selected from a sample of trainees attending a basic colonoscopy skills course. Interviews were preceded by observations to gain contextual insights into the training experience. The data were analysed in stages through a process of reading and re-reading the transcripts, making initial descriptive observations and then annotating with discursive, linguistic and conceptual comments. Findings Four emerging themes were identified. A lack self-confidence was a barrier to progression, compounded by the emotional impact of making mistakes without comprehensible constructive feedback. Attitudes of trainers and other endoscopy staff, as well as their relationships with trainees, had an impact on self-confidence and educational experience. Pressure on endoscopy units to perform procedures led to a tendency to treat training like a burden, although training was seen as an important investment. Trainees sought to differentiate nurse endoscopist and medical endoscopist roles and justify their skills and value, with comparisons between different nurse and medical trainers. Conclusion The emerging themes illustrate the requirement for a collegiate approach to endoscopy training.

Volcanogenic clays in Jurassic and Cretaceous strata of England and the North Sea Basin

Clay Minerals ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 25-55 ◽  
Author(s):  
C. V. Jeans ◽  
D. S. Wray ◽  
R. J. Merriman ◽  
M. J. Fisher
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
North Sea ◽  
Volcanic Ash ◽  
Hydrothermal Fluids ◽  
Mineral Deposits ◽  
The North ◽  
Clay Deposits ◽  
The North Sea ◽  
Thermal Doming

AbstractThe nature and origin of authigenic clay minerals and silicate cements in the Jurassic and Cretaceous sediments of England and the North Sea are discussed in relation to penecontemporaneous volcanism in and around the North Sea Basin. Evidence, including new REE data, suggests that the authigenic clay minerals represent the argillization of volcanic ash under varying diagenetic conditions, and that volcanic ash is a likely source for at least the early silicate cements in many sandstones. The nature and origin of smectite-rich, glauconite-rich, berthierine-rich and kaolin-rich volcanogenic clay mineral deposits are discussed. Two patterns of volcanogenic clay minerals facies are described. Pattern A is related to ash argillization in the non-marine and marine environments. Pattern B is developed by the argillization of ash concentrated in the sand and silt facies belts in the seas bordering ash-covered islands and massifs. It is associated with regression/ transgression cycles which may be related to thermal doming and associated volcanism, including the submarine release of hydrothermal fluids rich in Fe. The apparent paucity of volcanogenic clay deposits in the Jurasssic and Early Cretaceous sediments of the North Sea is discussed.

scholarly journals Lost in Transition? Directions for an Economic Geography of Urban Sustainability Transitions

2018 ◽  
Vol 10 (7) ◽  
pp. 2434 ◽  
Author(s):  
Sebastian Fastenrath ◽  
Boris Braun
Keyword(s):  
Economic Geography ◽  
Urban Sustainability ◽  
Research Field ◽  
Decision Makers ◽  
Sustainability Transitions ◽  
Political Processes ◽  
Production And Consumption ◽  
Increasing Demand ◽  
The City

Socio-technical transitions towards more sustainable modes of production and consumption are receiving increasing attention in the academic world and also from political and economic decision-makers. There is increasing demand for resource-efficient technologies and institutional innovations, particularly at the city level. However, it is widely unclear how processes of change evolve and develop and how they are embedded in different socio-spatial contexts. While numerous scholars have contributed to the vibrant research field around sustainability transitions, the geographical expertise largely has been ignored. The lack of knowledge about the role of spatial contexts, learning processes, and the co-evolution of technological, economical, and socio-political processes has been prominently addressed. Bridging approaches from Transition Studies and perspectives of Economic Geography, the paper presents conceptual ideas for an evolutionary and relational understanding of urban sustainability transitions. The paper introduces new perspectives on sustainability transitions towards a better understanding of socio-spatial contexts.

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