scholarly journals Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4014
Author(s):  
Karol Prałat ◽  
Andżelika Krupińska ◽  
Marek Ochowiak ◽  
Sylwia Włodarczak ◽  
Magdalena Matuszak ◽  
...  
Keyword(s):  
Construction Material ◽  
Construction Materials ◽  
Optical Microscope ◽  
Passive Layer ◽  
Initial State ◽  
Time Intervals ◽  
Significant Deterioration ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Steel Heat

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

TEMPERATURE DEPENDENCE OF RELAXATION IN AlGaN/GaN HETEROSTRUCTURES

2007 ◽  
Vol 14 (04) ◽  
pp. 837-840
Author(s):  
Z. S. JIANG ◽  
W. ZHANG ◽  
Q. JI ◽  
J. XU ◽  
D. J. CHEN ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Tensile Strain ◽  
Lattice Strain ◽  
Passive Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
The Difference ◽  
Increasing Temperature

Effects of Si 3 N 4 passivation layer on the lattice strain of Al 0.22 Ga 0.78 N layer with the thickness of 100 nm has been studied by in situ X-ray diffraction by the temperature range of 25°C–550°C. Results show that the temperature dependence of the strain relaxations can be separated into three linear regions. After passivation, an additional in-plane tensile strain is observed. The residual tensile strain increases with increasing temperature at low temperature, while at higher temperature the residual tensile strain decreases slightly. There is clear influence when a passive layer is deposited on the surface of the heterostructures. The linear regions in the temperature dependence of strain vary after the passive layer deposited on the heterostructure. These results indicate that the variation of the lattice strain relates to the difference in thermal stability between the epitaxy layer and the substrate.

Effect on Cs removal of solid-phase metal oxidation in metal ferrocyanides

2017 ◽  
Vol 105 (12) ◽  
Author(s):  
Keun-Young Lee ◽  
Jimin Kim ◽  
Maengkyo Oh ◽  
Eil-Hee Lee ◽  
Kwang-Wook Kim ◽  
...  
Keyword(s):  
Treatment Process ◽  
Solid Phase ◽  
Storage Conditions ◽  
Radioactive Cesium ◽  
Metal Oxidation ◽  
Aging Period ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
And Storage ◽  
Cobalt And Nickel

AbstractMetal ferrocyanides (MFCs) have been studied for many years and are regarded as efficient adsorbents for the selective removal of radioactive cesium (Cs) from contaminated aqueous solutions. Although their efficiency has been demonstrated, various investigations on the physicochemical, thermal, and radiological stability of the solids of MFCs are required to enhance the applicability of MFCs in the treatment process. We observed that the Cs adsorption efficiencies of cobalt and nickel ferrocyanides decreased as their aging period increased, while the Cs adsorption efficiencies of copper and zinc ferrocyanides did not decrease. The tendencies of these ferrocyanides were accelerated by exposure of the solids at a higher temperature for a longer time. Our comprehensive analyses demonstrated that only the oxidizable metals in the MFCs can be oxidized by aging time and increasing temperature; also, this affects the Cs removal efficiency by decreasing the exchangeable sites in the solids. The chemical stability of MFCs is very important for the optimization of the synthesis and storage conditions.

EFFECT OF YELLOW LOESS ON ODOROUS GAS ADSORPTION AND ECOTOXICITY TEST USING DAPHNIA MAGNA

2021 ◽  
Vol 16 (1) ◽  
pp. 103-114
Author(s):  
Hongseok Jang ◽  
Boram Lee ◽  
Seungyoung So
Keyword(s):  
Daphnia Magna ◽  
Cement Mortar ◽  
Construction Material ◽  
Objective Assessment ◽  
Test Chamber ◽  
Construction Materials ◽  
Ecotoxicity Test ◽  
Lamellar Crystal ◽  
Exposure Test ◽  
Natural Materials

ABSTRACT To minimize damage caused by harmful substances released from artificial construction materials, there has been increasing interest in eco-friendly houses constructed with natural materials. Among natural materials, yellow loess is South Korea’s most representative eco-friendly construction material, with high purification performance for indoor use. However, there has been no objective assessment of yellow loess’s performance at purifying indoor air. In this study, internal pores were found in yellow loess that were of a lamellar crystal structure consisting of bonds of silica and alumina plates, and there was a high negative charge on the loess surface; these might have contributed to the excellent performance of yellow loess in adsorbing odorous gas. There was also an exposure test using Daphnia magna to determine the eco-friendliness of yellow loess compared with that of cement mortar. Results showed the survival of Daphnia magna was longer in the indoor environment of a test chamber with higher concentration of ammonia wherein yellow loess was placed. EC50 (median effective concentration, the concentration that caused death of 50% of bio-specimens) value of 19 ml of ammonia (0.1% solution), which was three times more than EC50 value of 6 ml of ammonia of the same area of cement mortar.

Modeling the Growth of Salmonella in Cut Red Round Tomatoes as a Function of Temperature

2010 ◽  
Vol 73 (8) ◽  
pp. 1502-1505 ◽  
Author(s):  
WENJING PAN ◽  
DONALD W. SCHAFFNER
Keyword(s):  
Mathematical Model ◽  
Growth Rates ◽  
Low Temperatures ◽  
Safety Concern ◽  
Time Intervals ◽  
Salmonella Serotypes ◽  
Increasing Temperature ◽  
Incubation Temperatures ◽  
Raw Poultry ◽  
The Relationship

Tomato-associated Salmonella outbreaks have recently become a significant food safety concern. Temperature abuse of cut tomatoes may have played a role in some of these outbreaks. The purpose of this study was to develop a mathematical model to describe the growth of Salmonella on cut tomatoes at various temperatures. Four Salmonella serotypes (Typhimurium, Newport, Javiana, and Braenderup) obtained from previous tomato-linked cases of salmonellosis were used in this study. These four serotypes were cultured separately, combined into a cocktail, and inoculated onto whole red round tomatoes and allowed to dry overnight. The tomatoes were then cut into pieces and incubated at a predetermined range of temperatures (10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, and 35°C). Salmonella concentration was measured at specified time intervals to determine the growth curve for Salmonella on cut tomatoes at each temperature. The growth rates were calculated using DMFit and used to build a mathematical model to illustrate the relationship between the growth rates of Salmonella on tomatoes and incubation temperatures from 10 to 35°C. The resulting model compared favorably with a Salmonella growth model for raw poultry developed by our laboratory. The Pathogen Modeling Program underpredicted growth at low temperatures and overpredicted growth at high temperatures. ComBase predicted consistently slower growth rates than were observed in tomatoes but showed parallel increases in growth rate with increasing temperature.

Study of the Effect of PP and LDPE Thermoplastic Binder Addition on the Mechanical Properties and Physical Properties of Particulate Composites for Building Material Application

2019 ◽  
Vol 964 ◽  
pp. 115-123
Author(s):  
Sigit Tri Wicaksono ◽  
Hosta Ardhyananta ◽  
Amaliya Rasyida ◽  
Feisha Fadila Rifki
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Building Materials ◽  
Construction Material ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Waste Recycling ◽  
Plastic Waste ◽  
Particulate Composites ◽  
Water Absorbability

Plastic waste is majority an organic material that cannot easily decomposed by bacteria, so it needs to be recycled. One of the utilization of plastic waste recycling is become a mixture in the manufacture of building materials such as concrete, paving block, tiles, roof. This experiment purpose to find out the effect of addition of variation of LDPE and PP thermoplastic binder to physical and mechanical properties of LDPE/PP/Sand composite for construction material application. In this experiment are using many tests, such are SEM, FTIR, compression strength, density, water absorbability, and hardness. the result after the test are the best composition of composite PP/LDPE/sand is 70/0/30 because its have compression strength 14,2 MPa, while density value was 1.30 g/cm3, for the water absorbability is 0.073%, and for the highest hardness is 62.3 hardness of shore D. From the results obtained, composite material can be classified into construction materials for mortar application S type with average compression strength is 12.4 MPa.

New Lightweight Construction Material: Cellular Mat Using Recycled Plastic

2013 ◽  
Vol 594-595 ◽  
pp. 503-510
Author(s):  
T.I.T. Noor Hasanah ◽  
D.C. Wijeyesekera ◽  
Ismail bin Bakar ◽  
Wahab Saidin
Keyword(s):  
Cellular Structure ◽  
Construction Material ◽  
Construction Materials ◽  
Base Material ◽  
Social Benefit ◽  
The Body ◽  
Lightweight Construction ◽  
Ground Condition ◽  
Application Specific ◽  
Design And Construction

Applications of lightweight construction materials enable the design and construction in challenging, difficult and demanding scenarios. Construction materials with enhanced stiffness as in sandwich panels, large portable structures and floating foundations are examples of such materials. The advent of cellular structure technology has actively introduced innovation and enabled design and construction, meeting engineering requirements such as in the construction of the body of air crafts. Cellular mat structures present in the minimum, triple benefits in being lightweight, load sharing and minimising non-uniform deformation. This paper further explores the use of recycled plastic waste as the base material for an innovative geomaterial. The combination of cellular structure, mat structure and use of recycled waste material is a desirable development in manufacturing. Paper also outlines the techno social benefit of adopting such material in construction. Other application-specific benefits related to cellular mats are those like noise reduction, energy absorption, thermal insulation, mechanical damping. This paper specifically presents the development of a new multifunctional lightweight material is been proposed as an invective innovation for highway construction on challenging ground condition.

scholarly journals Application of Wall and Insulation Materials on Green Building: A Review

2018 ◽  
Vol 10 (9) ◽  
pp. 3331 ◽  
Author(s):  
Hao Wang ◽  
Pen-Chi Chiang ◽  
Yanpeng Cai ◽  
Chunhui Li ◽  
Xuan Wang ◽  
...  
Keyword(s):  
Thermal Insulation ◽  
Construction Material ◽  
Construction Materials ◽  
Green Building ◽  
Development Trend ◽  
Plant Fibers ◽  
Sustainable Resources ◽  
Insulation Materials ◽  
Green Construction ◽  
Wall Materials

The construction materials utilized in the building sector have accounted for a large amount of natural resource and energy consumption. Green building, which has developed over three decades, can be regarded as a management and technical approach for building and construction sectors to achieve resource and energy sustainability in building sectors. Therefore, the development and deployment of green construction materials play an important role in the green building field due to the contribution of sustainable resources and energy. To realize the barriers of energy and resources utilization on green building, the development trend, application, and some case studies on wall materials and thermal insulation materials are described. A summary of plant fibers, recycled wastes, and photochromic glass is developed to show applications of green construction materials, which contributes to sustainable development. The challenges and barriers from business, technical, and policy aspects are also reviewed. Finally, perspectives and prospects of green construction material life-cycle framework are illustrated. This paper presents a snapshot review of the importance of wall materials and thermal insulation materials from the point of view of energy and resources consumption.

scholarly journals A Prototype Expert System for the Selection of Road Construction Materials

2007 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
S. Hassim ◽  
K.T. Teh ◽  
R. Muniandy ◽  
H. Omar ◽  
A. Hassan
Keyword(s):  
Expert System ◽  
Knowledge Base ◽  
Material Selection ◽  
Construction Material ◽  
Construction Materials ◽  
Road Construction ◽  
Statistical Testing ◽  
Factors Affecting ◽  
Microsoft Access ◽  
Programming Tool

A prototype for an expert system in road construction material selection system, which is based on the outcomes of Friedman and multiple comparisons statistical methods was developed. The outcomes were acquired through questionnaires from selected pavement experts. The factors affecting pavement materials under each particular site condition were incorporated into the specific rules of the system. The system knowledge-base was extracted from the statistical testing outcomes and then rearranged and compiled prior to the development of the system. Visual Basic 6.0 was adopted as the programming tool for development of the system, while the knowledge-base of the separate system was kept in Microsoft Access 2000. The prototype expert system can be used to emulate part of the professional reasoning capabilities based on the knowledge of a pavement expert or a specialist to solve problems on materials selection. The system can help road designers to improve their professional ability to evaluate all available materials even before carrying out any laboratory tests.

scholarly journals Probability distributions of COVID-19 tweet posted trends use a nonhomogeneous Poisson process

2020 ◽  
Vol 1 (4) ◽  
pp. 229-238
Author(s):  
Devi Munandar ◽  
Sudradjat Supian ◽  
Subiyanto Subiyanto
Keyword(s):  
Social Media ◽  
Poisson Process ◽  
Exponential Distribution ◽  
Probability Distributions ◽  
Nonhomogeneous Poisson Process ◽  
Time Interval ◽  
Initial State ◽  
Time Intervals ◽  
Time Parameters ◽  
Parameter Values

The influence of social media in disseminating information, especially during the COVID-19 pandemic, can be observed with time interval, so that the probability of number of tweets discussed by netizens on social media can be observed. The nonhomogeneous Poisson process (NHPP) is a Poisson process dependent on time parameters and the exponential distribution having unequal parameter values and, independently of each other. The probability of no occurrence an event in the initial state is one and the probability of an event in initial state is zero. Using of non-homogeneous Poisson in this paper aims to predict and count the number of tweet posts with the keyword coronavirus, COVID-19 with set time intervals every day. Posting of tweets from one time each day to the next do not affect each other and the number of tweets is not the same. The dataset used in this study is crawling of COVID-19 tweets three times a day with duration of 20 minutes each crawled for 13 days or 39 time intervals. The result of this study obtained predictions and calculated for the probability of the number of tweets for the tendency of netizens to post on the situation of the COVID-19 pandemic.

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