scholarly journals Comparison of Compressive and Tensile Strengths of Dry-Cast Concrete with Ordinary Portland and Portland Pozzolana Cements

2018 ◽  
Vol 4 (8) ◽  
pp. 1760 ◽  
Author(s):  
Rasyiid Lathiif Amhudo ◽  
Tavio Tavio ◽  
I Gusti Putu Raka
Keyword(s):  
Ordinary Portland Cement ◽  
Precast Concrete ◽  
Construction Material ◽  
Health And Safety ◽  
The Past ◽  
Splitting Test ◽  
The World ◽  
Cast Concrete ◽  
Concrete Placement ◽  
Portland Pozzolana Cement

Concrete is the most widely used construction material in the world. Along with the increasing economic needs in the development of construction, precast technology has become a primary solution that leads to the industrialization. The use of precast concrete system offers several advantages, such as rapid erection, higher product quality, lower project cost, better sustainability, and improved occupational health and safety. In general, there are two casting methods used in concrete placement, namely wet- and dry-castings. The dry-cast concrete has also been used for its advantages particularly in precast concrete industries, e.g. its rapid hardening time for fast mold removal (it significantly increases the plant productivity). The use of Portland Pozzolana Cement (PPC) as a replacement to Ordinary Portland Cement (OPC) has become increasingly popular for the past decade. Hence, its application in dry-cast method needs to be further investigated for its mechanical properties such as its compressive and splitting tensile strengths. An experimental work was carried out to examine the properties of dry-cast concrete using both types of cements (PPC and OPC). The development of its compressive strength was also monitored at 1, 7, 14, 21, 28, and 56 days of age. The splitting test was conducted to describe the tensile strength of dry-cast concrete. The observation of crack and failure behaviour of all concrete specimens were also carried out.

Application and Development of Materials for ‘Green’ Concrete

2013 ◽  
Vol 848 ◽  
pp. 135-138
Author(s):  
Jia Zi Shi ◽  
Xing Dang
Keyword(s):  
Environmental Impact ◽  
Construction Material ◽  
Recycled Aggregates ◽  
Mineral Admixtures ◽  
Environmental Damage ◽  
New Materials ◽  
Green Concrete ◽  
The Past ◽  
Concrete Production ◽  
The World

Concrete is the most commonly used construction material in the world over the past decades. But the increase in concrete production leads to an increase in greenhouse gases emission and environmental damage. With the current focus on sustainability, it is necessary to evaluate concretes environmental impact and develop new materials for green concrete. Green recycled aggregates and mineral admixtures are important component materials for green concrete. In this paper, the development of green concrete industry is introduced, and the application of materials for green concrete such as green recycled aggregates and mineral admixtures are discussed.

scholarly journals Evaluation of the Mechanical Behavior of Local Brick Masonry in Pakistan

2019 ◽  
Vol 9 (3) ◽  
pp. 4298-4300
Author(s):  
T. M. Shah ◽  
A. Kumar ◽  
S. N. R. Shah ◽  
A. A. Jhatial ◽  
M. H. Janwery
Keyword(s):  
Mechanical Behavior ◽  
Construction Material ◽  
Brick Masonry ◽  
Thickness Ratio ◽  
Masonry Structures ◽  
Crushing Strength ◽  
Load Bearing ◽  
The Past ◽  
The World ◽  
Considerable Damage

Masonry is the oldest form of construction in the world [1]. Research shows that it is the most widely used construction material in Pakistan and it has remained as such for more than the past hundred years. The majority of buildings in Pakistan are load-bearing burnt-brick masonry structures. Unfortunately, the brick masonry structures in Pakistan are not designed with respect to any regulatory code, because none exist. Consequently, these structures are not constructed according to a safe design and thus become hazardous and often face considerable damage and sometimes prove to be fatal. This study aims to study the behavior of local brick masonry under normal, shear and thermally challenging conditions and to model its behavior by relating the crushing strength (f’m) to the height-to-thickness ratio and temperature.

A basic introduction to image processing using NIH-Image as a model

1994 ◽  
Vol 52 ◽  
pp. 392-393
Author(s):  
John Mansfield
Keyword(s):  
Image Processing ◽  
Digital Image ◽  
Image Acquisition ◽  
Digital Instrument ◽  
Novice User ◽  
Nih Image ◽  
The Past ◽  
Digital World ◽  
The World ◽  
Instrument Control

Advances in camera technology and digital instrument control have meant that in modern microscopy, the image that was, in the past, typically recorded on a piece of film is now recorded directly into a computer. The transfer of the analog image seen in the microscope to the digitized picture in the computer does not mean, however, that the problems associated with recording images, analyzing them, and preparing them for publication, have all miraculously been solved. The steps involved in the recording an image to film remain largely intact in the digital world. The image is recorded, prepared for measurement in some way, analyzed, and then prepared for presentation.Digital image acquisition schemes are largely the realm of the microscope manufacturers, however, there are also a multitude of “homemade” acquisition systems in microscope laboratories around the world. It is not the mission of this tutorial to deal with the various acquisition systems, but rather to introduce the novice user to rudimentary image processing and measurement.

Regulatory and sustainability initiatives lead to improved polyaminopolyamide epichlorohydrin (PAE) wet-strength resins and paper products

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle
Keyword(s):  
Health And Safety ◽  
Cost Effective ◽  
Worker Safety ◽  
Regulatory Requirements ◽  
Wet Strength ◽  
The Past ◽  
Consumer Safety ◽  
Federal Institute ◽  
Sustainability Initiatives ◽  
The Impact

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).

On the Symbolism of Rain in A Farewell to Arms

2018 ◽  
Keyword(s):  
Research Tool ◽  
The Past ◽  
The World ◽  
Farewell To Arms

This paper critically analyzes the symbolic use of rain in A Farewell to Arms (1929). The researcher has applied the Sapir-Whorf Hypothesis as a research tool for the analysis of the text. This hypothesis argues that the languages spoken by a person determine how one observes this world and that the peculiarities encoded in each language are all different from one another. It affirms that speakers of different languages reflect the world in pretty different ways. Hemingway’s symbolic use of rain in A Farewell to Arms (1929) is denotative, connotative, and ironical. The narrator and protagonist, Frederick Henry symbolically embodies his own perceptions about the world around him. He time and again talks about rain when something embarrassing is about to ensue like disease, injury, arrest, retreat, defeat, escape, and even death. Secondly, Hemingway has connotatively used rain as a cleansing agent for washing the past memories out of his mind. Finally, the author has ironically used rain as a symbol when Henry insists on his love with Catherine Barkley while the latter being afraid of the rain finds herself dead in it.

Profilometry. Using Corneo-scleral topography for scleral lens fitting

The Eye ◽  
2019 ◽  
Vol 21 (128) ◽  
pp. 19-22
Author(s):  
Gregory DeNaeyer
Keyword(s):  
Ocular Surface ◽  
World Wide ◽  
Contact Lenses ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Way

The world-wide use of scleral contact lenses has dramatically increased over the past 10 year and has changed the way that we manage patients with corneal irregularity. Successfully fitting them can be challenging especially for eyes that have significant asymmetries of the cornea or sclera. The future of scleral lens fitting is utilizing corneo-scleral topography to accurately measure the anterior ocular surface and then using software to design lenses that identically match the scleral surface and evenly vault the cornea. This process allows the practitioner to efficiently fit a customized scleral lens that successfully provides the patient with comfortable wear and improved vision.

Aftershocks

2017 ◽  
Author(s):  
Seva Gunitsky
Keyword(s):  
Twentieth Century ◽  
Regime Change ◽  
International System ◽  
Political Legitimacy ◽  
Great Powers ◽  
Past Century ◽  
The Past ◽  
Sudden Rise ◽  
The World ◽  
National Borders

Over the past century, democracy spread around the world in turbulent bursts of change, sweeping across national borders in dramatic cascades of revolution and reform. This book offers a new global-oriented explanation for this wavelike spread and retreat—not only of democracy but also of its twentieth-century rivals, fascism, and communism. The book argues that waves of regime change are driven by the aftermath of cataclysmic disruptions to the international system. These hegemonic shocks, marked by the sudden rise and fall of great powers, have been essential and often-neglected drivers of domestic transformations. Though rare and fleeting, they not only repeatedly alter the global hierarchy of powerful states but also create unique and powerful opportunities for sweeping national reforms—by triggering military impositions, swiftly changing the incentives of domestic actors, or transforming the basis of political legitimacy itself. As a result, the evolution of modern regimes cannot be fully understood without examining the consequences of clashes between great powers, which repeatedly—and often unsuccessfully—sought to cajole, inspire, and intimidate other states into joining their camps.

The Tyranny of the Ideal

2018 ◽  
Author(s):  
Gerald Gaus
Keyword(s):  
Political Philosophy ◽  
Moral Life ◽  
Moral Inquiry ◽  
Open Society ◽  
The Past ◽  
Theories Of Justice ◽  
The World ◽  
Diverse Society ◽  
Just Society ◽  
The Ideal

This book lays out a vision for how we should theorize about justice in a diverse society. It shows how free and equal people, faced with intractable struggles and irreconcilable conflicts, might share a common moral life shaped by a just framework. The book argues that if we are to take diversity seriously and if moral inquiry is sincere about shaping the world, then the pursuit of idealized and perfect theories of justice—essentially, the entire production of theories of justice that has dominated political philosophy for the past forty years—needs to change. Drawing on recent work in social science and philosophy, the book points to an important paradox: only those in a heterogeneous society—with its various religious, moral, and political perspectives—have a reasonable hope of understanding what an ideally just society would be like. However, due to its very nature, this world could never be collectively devoted to any single ideal. The book defends the moral constitution of this pluralistic, open society, where the very clash and disagreement of ideals spurs all to better understand what their personal ideals of justice happen to be. Presenting an original framework for how we should think about morality, this book rigorously analyzes a theory of ideal justice more suitable for contemporary times.

History of Tour de France from the Geographical Point of View

2013 ◽  
Vol 22 (3-4) ◽  
pp. 255-277 ◽  
Author(s):  
Vladimír Bačík ◽  
Michal Klobučník
Keyword(s):  
Point Of View ◽  
The Past ◽  
Advanced Technologies ◽  
The World ◽  
Spatial Dimensions ◽  
Tour De France ◽  
Wide Circle ◽  
History Of ◽  
Expert Community ◽  
Geographical Point

Abstract The Tour de France, a three week bicycle race has a unique place in the world of sports. The 100th edition of the event took place in 2013. In the past of 110 years of its history, people noticed unique stories and duels in particular periods, celebrities that became legends that the world of sports will never forget. Also many places where the races unfolded made history in the Tour de France. In this article we tried to point out the spatial context of this event using advanced technologies for distribution of historical facts over the Internet. The Introduction briefly displays the attendance of a particular stage based on a regional point of view. The main topic deals with selected historical aspects of difficult ascents which every year decide the winner of Tour de France, and also attract fans from all over the world. In the final stage of the research, the distribution of results on the website available to a wide circle of fans of this sports event played a very significant part (www.tdfrance.eu). Using advanced methods and procedures we have tried to capture the historical and spatial dimensions of Tour de France in its general form and thus offering a new view of this unique sports event not only to the expert community, but for the general public as well.

Variable oil and argumentative conflict in the Middle East

2020 ◽  
pp. 824
Author(s):  
Malik Daham Mata’ab
Keyword(s):  
Middle East ◽  
Past Century ◽  
Large Area ◽  
The Past ◽  
The World

Oil has formed since its discovery so far one of the main causes of global conflict, has occupied this energy map a large area of conflict the world over the past century, and certainly this matter will continue for the next period in our century..

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