Studies Concerning the Corrosion Behaviour of the Cast Stainless Steel Used for Chemical Industry

2013 ◽  
Vol 371 ◽  
pp. 338-342
Author(s):  
Gheorghe Simionescu ◽  
Mirela Gheorghian
Keyword(s):  
Chemical Industry ◽  
Room Temperature ◽  
Corrosion Behaviour ◽  
Research Work ◽  
Experimental Tests ◽  
Hot Environment ◽  
Chemical Agents ◽  
The Subject ◽  
Materials Used ◽  
Cast Stainless Steel

The current work deals with experimental tests concerning the behaviour of different materials used in chemical industry when are exposed to diverse corrosions environments. During the research work four different metals have been tested, namely T15NiCr180, T15MoNiCr180, W4027 and W4059. The presented work is trying to classify the tested materials function to different chemical environment, different concentration of the environment, different temperature of the environment, and different expose time. Some of the substances which were considered as corrosion environment are: HNO3, H3PO4, NaCl, NH4Cl, C2H5OH, Petrol, NH4NO3, KNO3, K2CO3, Na2CO3, KMnO4, KOH and Ca (OH)2. The concentration of the corrosion solutions varies between 1% and 96%. Tests have been done at room temperature and hot environment of 100°C. Time is playing an important role on evolution of the corrosion. For this reason the samples have been analyzed after 48, 336, 720 and 2160 hours of exposes to chemical agents. To understand the comportment of the subject metals when are used in industry, samples have been tested for longer period of time, respectively 1, 3, 6 and 12 months. After each selected period of time the metallic samples were analyzed and measured to quantify the effect of the environment on the corrosion speed.

scholarly journals Comparative Study on the Corrosion Behaviour of welded and un-welded Mild Steel in Agitated Media of Distilled Water 0.5mol, 0.3mol of Sodium Sulphate (Na2SO4) Solution

2020 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Comparative Study ◽  
Mild Steel ◽  
Corrosion Behaviour ◽  
Research Work ◽  
Sodium Sulphate ◽  
General Corrosion ◽  
Distilled Water ◽  
Experimental Conditions ◽  
Analytical Instruments ◽  
Materials Used

The research work was based on the comparative study of the corrosion bebaviour of the mild steel using agitated distilled water with 0.5 mol and 0.3 mol of Na2SO4 solution. The materials used for the research work are welded and un-welded mild steel. The mild steel materials were obtained at the Foundry shop of the Ajaokuta Steel Company Limited. The mild steel materials were analyzed using the SPECTRO Analytical Instruments at the Foundry shop of the company. These experiments were performed using 0.5mol and 0.3mol of Na2SO4 in different agitated media of distilled water .The samples used for general corrosion studies were 10mm and 4mm mild steel thickness. These materials were cut into specimen sizes to 2cm by 2cm). Twenty -eight (28) specimens each were prepared for the 10mm and 4mm mild steel materials the samples were ground and polished on the emery papers which removed rust particles on the test materials. The specimens were exposed for days for over fifty –four (54) days, with an interval of 3days. It was observed that welded materials have higher corrosion rate than the un-welded materials when subjected to experimental conditions. The corrosion rates values were used to plot graphs against time of exposure.

Plastic deformation of θ ' in Al-4%Cu alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 576-577
Author(s):  
Shrikant P. Bhat
Keyword(s):  
Deformation Behavior ◽  
Room Temperature ◽  
Electron Microscopic Observation ◽  
Bulk Alloy ◽  
Electron Microscopic ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Orowan Mechanism ◽  
The Subject ◽  
Cyclic Straining

deformation behavior of Al-Cu alloys aged to contain θ ' has been the subject of many investigations (e.g., Ref. 1-5). Since θ ' is strong and hard, dislocations bypass θ ' plates (Orowan mechanism) at low strains. However, at high strains the partially coherent θ ' plates are probably sheared, although the mechanism is complex, depending on the form of deformation. Particularly, the cyclic straining of the bulk alloy is known to produce gross bends and twists of θ '. However, no detailed investigation of the deformation of θ ' has yet been reported; moreover, Calabrese and Laird interpreted the deformation of θ ' as largely being elastic.During an investigation of high temperature cyclic deformation, the detailed electron-microscopic observation revealed that, under reversed straining conditions, θ ' particles are severely distorted--bent and twisted depending on the local matrix constraint. A typical electronmicrograph, showing the twist is shown in Fig. 1. In order to establish whether the deformation is elastic or plastic, a sample from a specimen cycled at room temperature was heated inside the microscope and the results are presented in a series of micrographs (Fig. 2a-e).

scholarly journals Different Techniques to Mitigate Partial Shading in Photovoltaic Panels

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3863
Author(s):  
Tiago Alves ◽  
João Paulo N. Torres ◽  
Ricardo A. Marques Lameirinhas ◽  
Carlos A. F. Fernandes
Keyword(s):  
Cell Model ◽  
Research Work ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Pv System ◽  
Partial Shading ◽  
System Architectures ◽  
Pv Systems ◽  
Advantages And Disadvantages ◽  
Pv Panel

The effect of partial shading in photovoltaic (PV) panels is one of the biggest problems regarding power losses in PV systems. When the irradiance pattern throughout a PV panel is inequal, some cells with the possibility of higher power production will produce less and start to deteriorate. The objective of this research work is to present, test and discuss different techniques to help mitigate partial shading in PV panels, observing and commenting the advantages and disadvantages for different PV technologies under different operating conditions. The motivation is to contribute with research, simulation, and experimental work. Several state-of-the-artsolutions to the problem will be presented: different topologies in the interconnection of the panels; different PV system architectures, and also introducing new solution hypotheses, such as different cell interconnections topologies. Alongside, benefits and limitations will be discussed. To obtain actual results, the simulation work was conducted by creating MATLAB/Simulink models for each different technique tested, all centered around the 1M5P PV cell model. The several techniques tested will also take into account different patterns and sizes of partial shading, different PV panel technologies, different values of source irradiation, and different PV array sizes. The results will be discussed and validated by experimental tests.

scholarly journals Experimental tests of PVD AlCrN-coated planer knives on planing Scots pine (Pinus sylvestris L.) under industrial conditions

2021 ◽  
Author(s):  
Krzysztof Nadolny ◽  
Wojciech Kapłonek ◽  
Marzena Sutowska ◽  
Paweł Sutowski ◽  
Piotr Myśliński ◽  
...  
Keyword(s):  
Research Work ◽  
Experimental Tests ◽  
Technical Condition ◽  
Cutting Edge ◽  
Raw Material ◽  
Edge Condition ◽  
Wear Area ◽  
Pine Wood ◽  
Wood Processing ◽  
Machining Operations

AbstractRaw pine wood processing and especially its mechanical processing constitute a significant share among technological operations leading to obtaining a finished product. Stable implementation of machining operations, ensuring long-term repeatable processing results depends on many factors, such as quality and invariability of raw material, technical condition of technological equipment, adopted parameters of work, qualifications and experience of operators, as well as preparation and properties of the machining tools used. It seems that the greatest potential in the search for opportunities to increase the efficiency of machining operations has the modification of machining tools used in it. This paper presents the results of research work aimed at determining how the life of cutting tools used in planing operations of wet pine wood is affected by the application of chromium aluminum nitride (AlCrN) coating to planar industrial planing knives in the process of physical vapour deposition. For this purpose operational tests were carried out under production conditions in a medium-sized wood processing company. The study compares the effective working time, rounding radius, the profile along the knife (size of worn edge displacement, wear area of the cutting edge), selected texture parameters of the planar industrial planing knife rake face and visual analyses of cutting edge condition of AlCrN-coated planar knives and unmodified ones. The obtained experimental results showed the possibility of increasing the life of AlCrN-coated knives up to 154% compared to the results obtained with uncoated ones. The proposed modification of the operational features of the knives does not involve any changes in the technological process of planing, does not require any interference with the machining station nor its parameters, therefore enabling rapid and easy implementation into industrial practice.

scholarly journals Thermal, Viscoelastic, Mechanical and Wear Behaviour of Nanoparticle Filled Polytetrafluoroethylene: A Comparison

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1940 ◽  
Author(s):  
Levente Ferenc Tóth ◽  
Patrick De Baets ◽  
Gábor Szebényi
Keyword(s):  
Room Temperature ◽  
Filler Content ◽  
Research Work ◽  
Tensile Modulus ◽  
Al2o3 Content ◽  
Wear Behaviour ◽  
X Ray ◽  
Mechanical Stirring ◽  
Wear Analysis ◽  
Sintering Method

In this research work, unfilled and mono-filled polytetrafluoroethylene (PTFE) materials were developed and characterised by physical, thermal, viscoelastic, mechanical, and wear analysis. The applied fillers were graphene, alumina (Al2O3), boehmite alumina (BA80), and hydrotalcite (MG70) in 0.25/1/4/8 and 16 wt % filler content. All samples were produced by room temperature pressing–free sintering method. All of the fillers were blended with PTFE by intensive dry mechanical stirring; the efficiency of the blending was analysed by Energy-dispersive X-ray spectroscopy (EDS) method. Compared to neat PTFE, graphene in 4/8/16 wt % improved the thermal conductivity by ~29%/~84%/~157%, respectively. All fillers increased the storage, shear and tensile modulus and decreased the ductility. PTFE with 4 wt % Al2O3 content reached the lowest wear rate; the reduction was more than two orders of magnitude compared to the neat PTFE.

SELECTION OF CONTROLLABLE PARAMETERS OF THE BINARY DATA ARRAY DETECTION ALGORITHM IN THE INTEGRATED MANAGEMENT SYSTEM

2021 ◽  
Vol 4 (3) ◽  
pp. 11-18
Author(s):  
Khakimjon Zaynidinov ◽  
◽  
Odilbek Askaraliyev
Keyword(s):  
Management System ◽  
Binary Data ◽  
Integrated Management ◽  
Research Work ◽  
Hash Functions ◽  
Experimental Tests ◽  
Detection Algorithm ◽  
Identification Algorithm ◽  
Solution Algorithms ◽  
Selection Of

The article discusses the selection of parameters for the algorithm for determining binary data arrays included in the control system, developed by the authors using independent substitution methods. Based on the analysis of the algorithms of non-cryptographic hash functions, the hash function based on the linear matching method was selected as the basis for independent substitution methods. Simplified schemes of algorithms developed for creating and comparing identifiers using a set of basic hash functions are given. An array of binary data was selected and based on the appropriate values for the size of the divisible blocks and the number of basic hashfunctions used for independent substitutions. The selection of binary data arrays in information systems integrated into the management system was done for the purpose of intellectual processing of incoming data. The properties of the array of data entering integrated systems are studied. The authors conducted experimental tests in the selected direction and presented the results of similarity assessment measurements for various parameters of the identification algorithm. In addition, the article conductedexperiments on the object of study using the selected mathematical model, based on the analytical conclusions. Initiator elements are studied and analyzed using a set of hash functions. An algorithm for comparison of selected identifiers has been developed. A generation algorithm has been developed to demonstrate and test the proposed solution. Algorithms based on analysis and experiments, and methods for selecting binary data arrays using the ash function have been experimentally tested. Based on the results, the indicators are shown. Based on the results obtained, the analytical conclusions and problem solutions of the research work were recognized

Structures and phase transitions in barium sodium niobate tungsten bronze (BNN)

2021 ◽  
Vol 77 (6) ◽  
Author(s):  
Thomas A. Whittle ◽  
Christopher J. Howard ◽  
Siegbert Schmid
Keyword(s):  
Phase Transitions ◽  
Room Temperature ◽  
Tungsten Bronze ◽  
Standard Setting ◽  
Experimental Results ◽  
Temperature Structure ◽  
Sodium Niobate ◽  
Tetragonal Tungsten Bronze ◽  
Space Group ◽  
The Subject

The room-temperature structure of the filled tetragonal tungsten bronze, Ba2NaNb5O15 (BNN), has been the subject of a number of studies, and these studies have given an almost corresponding number of different results. From a group theoretical examination of the different possibilities and a review of the published experimental results we conclude that the room-temperature structure is that proposed by Labbé et al. [J. Phys. Condens. Matter (1989), 2, 25–43] in the space group Bbm2 (Ama2 in standard setting) on a 2\sqrt{2}a × \sqrt{2}a × 2c cell. Upon heating, the structure remains ferroelectric but becomes tetragonal (space group P4bm) at 550 K, then paraelectric (space group P4/mbm) at and above 860 K.

Unfair dismissal in the Mauritius context: a comparative study

2018 ◽  
Vol 60 (6) ◽  
pp. 1299-1312
Author(s):  
Ambareen Beebeejaun
Keyword(s):  
Design Methodology ◽  
Research Work ◽  
Procedural Fairness ◽  
Content Type ◽  
Monetary Compensation ◽  
Unfair Dismissal ◽  
The Subject ◽  
The Law ◽  
Employment Rights ◽  
Practical Recommendations

Purpose The purpose of this study is to critically analyse the concept of unfair dismissal and to assess the extent to which the Employment Rights Act 2008 is affording protection to employees in Mauritius. The purpose of this study is to also demonstrate that as employees form an integral part of their workplace, their employment cannot be terminated without substantive and procedural fairness. The paper will provide some recommendations to cater for loopholes in existing Mauritius employment legislations. Design/Methodology/Approach To critically examine the topic, the black letter approach is adopted to detail legislations and judgments of courts on the subject matter. A comparative analysis with some other jurisdictions’ employment legislations is also carried out to define, explain and examine the concepts of dismissal, substantive causes such as misconduct and procedural fairness. Findings From the methodologies used, it is found that a substantial reason is not sufficient to conclude whether a dismissal is fair. The law of unfair dismissal has introduced some procedural safeguards to protect the employee from being unfairly and unjustifiably dismissed. The procedural requirements act as guidelines to employers and if they are not followed properly, the dismissal will be unfair. Unfair dismissal needs to be accompanied by remedies from employers, and monetary compensation has been found to be the most appropriate remedy. Originality/Value This paper is amongst the first research work conducted in Mauritius that compares the law of unfair dismissal and its implications with the laws of England and South Africa. The study is carried out with a view to provide practical recommendations in this area of employment law to the relevant stakeholders concerned.

scholarly journals Synthesis of Cu and Ce co-doped ZnO nanoparticles: crystallographic, optical, molecular, morphological and magnetic studies

2017 ◽  
Vol 35 (2) ◽  
pp. 427-434 ◽  
Author(s):  
Mohit Rawat ◽  
Jasmeet Singh ◽  
Jagpreet Singh ◽  
Chamkaur Singh ◽  
Amritpal Singh ◽  
...  
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Research Work ◽  
Yellow Emission ◽  
Near Band Edge ◽  
Band Edge Emission ◽  
Ferromagnetic Behavior ◽  
Magnetic Studies ◽  
Transmission Electron Microscopy Analysis ◽  
Co Doped

Abstract In the present research work, crystallographic, optical, molecular, morphological and magnetic properties of Zn1-xCuxO (ZnCu) and Zn1-x-yCeyCuxO (ZnCeCu) nanoparticles have been investigated. Polyvinyl alcohol (PVA) coated ZnCu and ZnCeCu nanoparticles have been synthesized by chemical sol-gel method and thoroughly studied using various characterization techniques. X-ray diffraction pattern indicates the wurtzite structure of the synthesized ZnCu and ZnCeCu particles. Transmission electron microscopy analysis shows that the synthesized ZnCu and ZnCeCu particles are of spherical shape, having average sizes of 27 nm and 23 nm, respectively. The incorporation of Cu and Ce in the ZnO lattice has been confirmed through Fourier transform infrared spectroscopy. Room temperature photoluminescence spectra of the ZnO doped with Cu and co-doped Ce display two emission bands, predominant ultra-violet near-band edge emission at 409.9 nm (3 eV) and a weak green-yellow emission at 432.65 nm (2.27 eV). Room temperature magnetic study confirms the diamagnetic behavior of ZnCu and ferromagnetic behavior of ZnCeCu.

scholarly journals Effects of humid and hot environment on fiber composites in cooling towers

2021 ◽  
pp. 29-29
Author(s):  
Li Qiu ◽  
Yong-Gui Li ◽  
Yan-Ping Xiong ◽  
Xiao-Dong Chen
Keyword(s):  
Glass Fibers ◽  
Fractal Dimensions ◽  
Fiber Composites ◽  
Cooling Towers ◽  
Composite Matrix ◽  
Hot Environment ◽  
Glass Fiber Reinforced ◽  
Low Efficiency ◽  
Materials Used ◽  
Fiber Reinforced Material

Polyvinyl chloride (PVC) materials used in cooling towers always lead to damage and low efficiency due to the hot and humid environment. This paper suggests a glass fiber reinforced material for a better performance. An optimal fractal distribution of glass fibers in the composite matrix is experimentally obtained when the fractal dimensions are between 0.6 and 0.9.

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