Study of capability of microorganisms to develop on construction materials used in space objects.

2006 ◽  
Author(s):  
Mrs. Yulia Svistunova
Keyword(s):  
Construction Materials ◽  
Space Objects ◽  
Materials Used

AMS Dating of Potentially the Oldest Wooden Sculptures in Japan from a Shinto Shrine in Akita

Radiocarbon ◽  
2019 ◽  
Vol 61 (5) ◽  
pp. 1221-1228
Author(s):  
Naoto Fukuyo ◽  
Yusuke Yokoyama ◽  
Yosuke Miyairi ◽  
Yusuke Igarashi
Keyword(s):  
Tree Rings ◽  
Age Determination ◽  
Construction Materials ◽  
Historical Documents ◽  
Matching Method ◽  
Historical Objects ◽  
Ams Dating ◽  
Akita Prefecture ◽  
Materials Used ◽  
Matching Techniques

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calendar ages of wood, as well as provide some supportive information for the periods when there are no reliable historical documents.

scholarly journals Optimum Thickness of Thermal Insulation with Both Economic and Ecological Costs of Heating and Cooling

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3835
Author(s):  
Robert Dylewski ◽  
Janusz Adamczyk
Keyword(s):  
Thermal Insulation ◽  
Construction Materials ◽  
Optimum Thickness ◽  
Degree Days ◽  
Transfer Coefficients ◽  
Cooling Period ◽  
Heating And Cooling ◽  
Optimum Heat ◽  
Materials Used ◽  
Building Walls

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.

scholarly journals Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati
Keyword(s):  
Numerical Model ◽  
Construction Materials ◽  
Building Codes ◽  
Construction Technique ◽  
Infill Walls ◽  
Mortar Strength ◽  
Materials Used ◽  
Seismic Response Of Buildings

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.

scholarly journals Environmental Performance Enters Construction Materials

MRS Bulletin ◽  
2008 ◽  
Vol 33 (4) ◽  
pp. 454-456 ◽  
Author(s):  
Peter Bonfield
Keyword(s):  
United Kingdom ◽  
Environmental Sustainability ◽  
Construction Materials ◽  
Energy Performance ◽  
The European Union ◽  
The United Kingdom ◽  
Legal Term ◽  
Chain Of Custody ◽  
Materials Used ◽  
Impact Cost

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).

scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

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.

scholarly journals Application of erosion-control materials and spontaneous vegetation in the protection of reservoirs in southern and eastern Serbia

2009 ◽  
Vol 61 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Vjaceslava Matic ◽  
Gordana Djukanovic
Keyword(s):  
Construction Materials ◽  
Erosion Control ◽  
Entire Study ◽  
Control Structures ◽  
Erosion Processes ◽  
Field Investigations ◽  
Spontaneous Vegetation ◽  
Accredited Laboratories ◽  
Materials Used ◽  
Stone Concrete

The quality and stability of erosion-control materials in protection of reservoirs in Southern and Eastern Serbia have been examined both in the field and in accredited laboratories in our country. Field investigations have been carried out over a period of 15 years in Eastern Serbia and for up to 30 years in Southern Serbia, and they are still being conducted by monitoring the state and possible damage of consolidation-retention check dams, walls, and other erosion-control structures. The materials used in protection of the Selova and Grliste Reservoirs are typical construction materials, such as resistant natural stone, concrete of the BI group, i.e., MB 20, aggregate, synthetic elements, etc. Long-term monitoring of their state and minor deformations has shown that the materials were well-chosen and stable, and that there has been no significant damage, except for some minor crumbling and smaller cracks due to negligible scouring. This is all the result of prior thorough empirical and laboratory testing of applied materials, which helped to achieve stability and functionality of structures erected to prevent silting-up of the reservoir. Such a state has contributed to stabilization of erosion processes and reduction of sediment quantities, improvement of water quality, and advancement of the autochthonous vegetation (Salix L., Cornus L., Quercus L.). Vegetation has further mitigated erosion, decreased floods, and consolidated the structures, thereby improving the ecological quality of the catchments as well as the entire study area.

scholarly journals A Scale Model of Tension Structures in Road Tunnels to Optimize the Use of Solar Light for Energy Saving

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Antonio Peña-García ◽  
Luisa-María Gil-Martín ◽  
Roberto Escribano ◽  
Antonio Espín-Estrella
Keyword(s):  
Energy Savings ◽  
Construction Materials ◽  
Electricity Consumption ◽  
Scale Model ◽  
Major Influence ◽  
Road Tunnels ◽  
Tension Structures ◽  
Materials Used ◽  
Set Up ◽  
New Equation

Shifting the threshold zone of road tunnels with semitransparent tension structures has shown itself to be an effective way of saving energy in regards to electricity consumption, maintenance, and construction materials used in the electrical lighting, thus lessening negative environmental impacts. Even though the shape of the tension structure has a major influence on energy savings, the optimal type of structure for each tunnel is often difficult to determine, because experiments using real tunnels are extremely expensive. It is thus necessary to find methods of doing this that are both reliable as well as economical. In this research study, three candidate structures were set up at the portal of a scale model of a real tunnel. The energy savings in each case were analyzed and compared. As a result, it was possible to formulate a new equation that calculates the energy savings in the threshold zone.

Assessment of the technical condition of mines with mechanical fuses

2021 ◽  
Vol 2021 (1) ◽  
pp. 1-12
Author(s):  
Adam Kubecki ◽  
Cezary Śliwiński ◽  
Janusz Śliwiński ◽  
Ireneusz Lubach ◽  
Leszek Bogdan ◽  
...  
Keyword(s):  
Construction Materials ◽  
Armed Forces ◽  
Operational Reliability ◽  
Strength Properties ◽  
Technical Condition ◽  
Armed Conflicts ◽  
Long Term Storage ◽  
Precise Adjustment ◽  
Main Charge ◽  
Materials Used

Contemporary armed conflicts reveal that the use of effective mine barriers has a significant impact on the course of hostilities. Therefore, the Polish Armed Forces selected reliable and effective explosive ordnance as a priority, both newly-acquired material and those currently in operation. For this reason, among others, strict supervision over the technical condition of mines is exercised, in particular during their long-term storage. The reasons behind the increased mine unreliability may include physical and chemical changes in the construction materials used (corrosion, deformations, loss of strength properties), deterioration of the physicochemical properties of the main charge, booster and primer-detonator, inadequate technical condition of the safety components, or the failure of mine fuse mechanisms. In order to assess the mine's operational reliability, each mine fuse subassembly is examined and then a check of the entire assembled mine is performed. This requires proper planning of the full test cycle and the use of inspected and calibrated measuring devices and test stands enabling the precise adjustment of mechanical and climatic stress parameters.

Revaluation of Ksar El-Haouita in Laghouat, Algeria

2021 ◽  
Author(s):  
Fatiha Imane Mahcar ◽  
Belkacem Takhi
Keyword(s):  
Morphological Analysis ◽  
Construction Materials ◽  
Architectural Heritage ◽  
Theoretical Underpinning ◽  
Great Resistance ◽  
Basic Principles ◽  
Construction Techniques ◽  
Materials Used ◽  
Local Materials

Algeria has a rich urban and architectural heritage, which presents regional specificities. Once the ksour was a symbol of balance and perfect harmony with its environment, unfortunately today they no longer reflect their former function. The Ksourian architecture, including that of Laghouat is a prestigious heritage of high value; it is the testimony of genius knowledge and the capacity of their occupants to adapt to the difficult environment. The housing is considered the essential core of this architecture it represents the entire composition of the ksar, its design is inspired by the immediate environment and respects ancestral social values. It is characterized by a simple architecture and simple construction techniques which are based on the construction in load-bearing walls, the construction materials used are local materials of great resistance and less expensive. This study addresses the theme revaluation of heritage, particularly our case study ksar El-Haouita which has experienced a neglecting and depopulation due to several factors. The ksar El-Haouita is among the most famous ksour located in the south of Algeria and exactly in the region of Laghouat. It is built with simple materials and techniques of construction. The construction materials used are local materials like stones and lime found in the environmental surroundings of the ksar. The aim of this study is to identify the major causes of the degradation of ksar, also to preserve ksar El-Haouita through specific operations and to improve the tourist attractiveness of ksar El-Haouita in order to promote heritage, to convert it back into sustainable Saharan tourism. Our study based in the first place; on a theoretical underpinning which contains the notions that have a relation with our theme, the problematic and the envisaged objective, then a presentation of ksar followed by a morphological analysis accompanied by identification of the problems to identify the phenomena of damage and its disfigurement. The last step is to treat an aspect for the development of ksar, this aspect is devoted to the restitution of the defensive system (doors, ramparts, ramparts of houses and towers) of the ksar, through a diagnostic and several operations like (rehabilitation and reconstruction). The aim result of this study is to show that the revaluation of the ksar is a very vast operation and proposes interventions that allow the preservation of the ksar and also to understand the elements that help the success of interventions and to put some of the parameters considered as reference elements and basic principles for the operations on the ksar and among these operations it is (the case study, which is the restitution of the defensive system of ksar El-Haouita).

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