Construction Materials for Adhesive Bonding in Present-Day Industry

This chapter presents the characteristics of selected construction materials used in the modern industry, with particular attention paid to the engineering industry. These materials have a diverse chemical structure and related properties. In this context, steels, selected light alloys, plastics, wood, glass, and ceramics were described. Since the materials for production are supplied in various forms, the methods of shaping the semi-finished products of the presented materials were outlined. Special attention was given to the condition of the surface and the shape due to the possible bonding operations in the technological process. Additionally, a description of composites was given, as these materials have already replaced a number of materials used so far. Composites are characterized by having favorable features and are produced with the use epoxy resins, among others. This chapter also outlines the characteristics of adhesives in the context of their selection options for the glued materials.

2021 ◽  
Vol 2 (1) ◽  
pp. 100-109
Author(s):  
Jailson de Araújo Santos ◽  
Daniel Barbosa Liarte ◽  
Alessandra Braga Ribeiro ◽  
Marcia dos Santos Rizzo ◽  
Marcília Pinheiro da Costa ◽  
...  

Bacterial transformation and gene transfection can be understood as being the results of introducing specific genetic material into cells, resulting in gene expression, and adding a new genetic trait to the host cell. Many studies have been carried out to investigate different types of lipids and cationic polymers as promising nonviral vectors for DNA transfer. The present study aimed to carry out a systematic review on the use of biopolymeric materials as nonviral vectors. The methodology was carried out based on searches of scientific articles and applications for patents published or deposited from 2006 to 2020 in different databases for patents (EPO, USPTO, and INPI) and articles (Scopus, Web of Science, and Scielo). The results showed that there are some deposits of patents regarding the use of chitosan as a gene carrier. The 16 analyzed articles allowed us to infer that the use of biopolymers as nonviral vectors is limited due to the low diversity of biopolymers used for these purposes. It was also observed that the use of different materials as nonviral vectors is based on chemical structure modifications of the material, mainly by the addition of cationic groups. Thus, the use of biopolymers as nonviral vectors is still limited to only a few polysaccharide types, emphasizing the need for further studies involving the use of different biopolymers in processes of gene transfer.


Radiocarbon ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1221-1228
Author(s):  
Naoto Fukuyo ◽  
Yusuke Yokoyama ◽  
Yosuke Miyairi ◽  
Yusuke Igarashi

ABSTRACTWe analyzed rare wooden Komainu found at Akagami Shrine in Akita prefecture, Japan. The formation of historical objects is often thoroughly recorded in documents, although the formation age of this particular Komainu sculpture is still unknown due to its antiquity. Thus, age determination exercises have been conducted using radiocarbon (14C)-wiggle-matching techniques. Although only a limited quantity was available for sampling, we have successfully measured 14C samples in the sculptures along with several sets of tree rings. We interpret the Komainu sculptures age considering the age of the trees and the result obtained from the wooden construction materials used for the Akagami shrine. The results obtained from Komainu show a range from 550 CE to 1020 CE, which is consistent with the dates of the shrine’s formation. Thus, the multiple 14C-wiggle-matching method can determine precise calendar ages of wood, as well as provide some supportive information for the periods when there are no reliable historical documents.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3835
Author(s):  
Robert Dylewski ◽  
Janusz Adamczyk

The energy efficiency of the construction sector should be determined by the cleanliness of the environment and, thus, the health of society. The scientific aim of this article was to develop a methodology for determining the optimum thickness of thermal insulation, taking into account both economic and ecological aspects and considering both heating and cooling costs. The method takes into account the number of degree days of the heating period, as well as the number of degree days of the cooling period. Variants in terms of different types of thermal insulation, various types of construction materials for building walls, climatic zones and heat sources, were taken into consideration. In order to find the optimum thicknesses of thermal insulation, both in economic and ecological terms, a metacriterion was used. The optimum thicknesses of thermal insulation with the use of the metacriterion were obtained in the range of 0.11–0.55 m. It was observed that the values of the optimum heat transfer coefficients for economic and ecological reasons do not depend on the type of construction materials used for vertical walls. The type of applied heat source is of the greatest importance for the size of the economic and ecological benefits. The proposed mathematical model for determining the optimum thickness of thermal insulation with the use of a metacriterion is a kind of generalization of earlier models from the literature.


Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.


MRS Bulletin ◽  
2008 ◽  
Vol 33 (4) ◽  
pp. 454-456 ◽  
Author(s):  
Peter Bonfield

The environmental sustainability of materials used in construction applications is driving a requirement for the quanti-fcation of performance attributes of such materials. For example, the European Union (EU) Energy Performance in Buildings Directive will give commercial buildings an energy rating when rented or sold. The Code for Sustainable Homes launched by the U.K. Government's Department for Communities and Local Government (CLG) in January 2007 sets out the requirement for all new homes to be carbonneutral by 2016. In addition, homes in the United Kingdom will need to signifcantly reduce water consumption from today's average 160 liters (1) per person per day to less than 801 per person per day. Similarly stringent targets are required for waste, materials, and other factors. Such environmental and energy standards are complementing characteristics such as strength, stiffness, durability, impact, cost, and expected life with factors such as “environmental profle,” “ecopoints” (a single unit measurement of environmental impact arising from a product throughout its lifecycle that is used in the United Kingdom), “carbon footprint” (amount of CO2 produced for the lifecycle of the item), “recycled content,” and “chain of custody” (a legal term that refers to the ability to guarantee the identity and integrity of a specimen from collection through to reporting of test results).


2020 ◽  
pp. 1-24
Author(s):  
Sonia Santos Gómez

Tempera painting on canvas has played multiple functions throughout the history of painting. They were used to cover altars in Lent, to make canopies and ceilings for beds, to act as organ doors, etc. In the 19th century and in the earlier 20th century, they were used as adornment on walls of palaces and theatres, as well as sceneries in the latter ones. Generally, this kind of tempera painting shows large proportions, which demanded a specific methodology of execution. Treatises of the epoch display how the painter, provided with paintbrushes of long handles, as brooms, walked on the canvases while the execution lasted. At that time, pigments derived from the activity of modern industry were already in use, in combination with other materials traditionally used in the previous centuries. This article presents the working methodology and materials used in tempera painting on canvas, mainly during the 19th century, providing a knowledge base for this subject.


2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.


Sign in / Sign up

Export Citation Format

Share Document