scholarly journals The Effects of Magnetic Nanoparticles Incorporated in Polyelectrolyte Capsules

2017 ◽  
Vol 54 (4) ◽  
pp. 645-647
Author(s):  
Corneliu Druga ◽  
Radu Necula ◽  
Diana Cotoros ◽  
Roxana Miclaus ◽  
Angela Repanovici ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Blood Circulation ◽  
Experimental Tests ◽  
Polymerization Reaction ◽  
Bone Cements ◽  
Relaxation Techniques ◽  
Health Issues ◽  
Monitoring Method ◽  
Different Types ◽  
Insertion Area

Most studies and experimental tests performed upon orthopaedic bone cements are related to their use in everyday conditions when usual wears are due to compression and fatigue. The present paper deals with some special situations occurred during the patient�s recovery after the surgery. The recovery activities and motions may induce different types of loads, like tensile, during stretching and relaxation techniques, especially in the joint insertion area. These situations are insufficiently researched, but they represent one of the main concerns of the medical staff involved in recovery and rehabilitation. Besides the study of mechanical properties for these special situations the paper proposes also a thermal analysis during preparation of the polymethylmethacrylate(PMMA) as it can be the trigger of serious health issues (necrosis, blood circulation problems, BCIS, etc.) due to the exothermic polymerization reaction. The monitoring method proposed for the temperatures developed during the polymerization may avoid the aforementioned issues.

scholarly journals Synthesis of Geopolymer Based Class-F Fly Ash Aggregates and its Composite Properties in Concrete

2014 ◽  
Vol 60 (1) ◽  
pp. 55-75 ◽  
Author(s):  
P. Gomathi ◽  
A. Sivakumar
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
Polymerization Reaction ◽  
Hardened Concrete ◽  
Different Types ◽  
Class F Fly Ash ◽  
Ash Aggregates ◽  
Class F

Abstract This study explores the influence of alkali activators on the initiation of polymerization reaction of alumino-silicate minerals present in class-F fly ash material. Different types of fly ash aggregates were produced with silicate rich binders (bentonite and metakaolin) and the effect of alkali activators on the strength gain properties were analyzed. A comprehensive examination on its physical and mechanical properties of the various artificial fly ash aggregates has been carried out systematically. A pelletizer machine was fabricated in this study to produce aggregate pellets from fly ash. The efficiency and strength of pellets was improved by mixing fly ash with different binder materials such as ground granulated blast furnace slag (GGBS), metakaolin and bentonite. Further, the activation of fl y ash binders was done using sodium hydroxide for improving its binding properties. Concrete mixes were designed and prepared with the different fly ash based aggregates containing different ingredients. Hardened concrete specimens after sufficient curing was tested for assessing the mechanical properties of different types concrete mixes. Test results indicated that fly ash -GGBS aggregates (30S2-100) with alkali activator at 10M exhibited highest crushing strength containing of 22.81 MPa. Similarly, the concrete mix with 20% fly ash-GGBS based aggregate reported a highest compressive strength of 31.98 MPa. The fly ash based aggregates containing different binders was found to possess adequate engineering properties which can be suggested for moderate construction works.

Mechanical Behavior of Glued Laminated Pressed Bamboo Guadua Using Different Adhesives and Environmental Conditions

2014 ◽  
Vol 600 ◽  
pp. 57-68 ◽  
Author(s):  
Patricia Luna ◽  
Caori Takeuchi ◽  
Edwar Cordón
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Environmental Conditions ◽  
Urea Formaldehyde ◽  
Experimental Tests ◽  
Mechanical Tests ◽  
Different Types ◽  
Humidity Chamber ◽  
Flexural Tests ◽  
The One

This paper presents the mechanical properties measured on glued laminated pressed guadua samples. Experimental tests like shear parallel to fiber, tensile and shear perpendicular to fiber and flexural tests were carried out using three different types of adhesives: European Melamine Urea Formaldehyde, Colombian Melamine Urea Formaldehyde, and Polivinil Acetate humidity resistant. In order to study the behavior of the material in aggressive environmental conditions, half of the samples used in the mechanical tests were introduced in a temperature and humidity chamber for 45 days set to 45°C of temperature and 95% of relative humidity, usual environmental conditions in Chocó Colombia.The results showed that the highest values of mechanical strength were obtained for samples made with European Melamine Urea Formaldehyde. In addition, it was found that this adhesive was the one with better behavior under the aggressive environmental conditions simulated.

Mechanical Properties Evaluation of Render Mortars with Different Waterproof Additive Compositions

2021 ◽  
Vol 880 ◽  
pp. 161-167
Author(s):  
Joaquin Humberto Aquino Rocha ◽  
Fernando Palacios Galarza
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Flexural Strength ◽  
Direct Effect ◽  
Compression Strength ◽  
Negative Impact ◽  
Experimental Tests ◽  
Strength Tests ◽  
Different Types ◽  
The Common

Waterproof additives and bonding agent mixtures are commonly employed in the setting up of render mortars. This practice often shows beneficial results, enhancing the properties of the common mortars. Yet, the use of these additives does not seem to have a direct effect on the mechanical properties of the mortars. This study thus aims to evaluate the influence of the use of waterproof and adhesion additives on the mechanical properties of render mortars. Based on their chemical composition, three different types of mortar admixtures were evaluated, using fourfold additive-mortar weight ratios: 0%, 1.5%, 3%, and 5%. Compressive and flexural strength tests were conducted after 28 days. The results showed a negative impact on the mechanical properties of the mortars. The lowest flexural and compression strength values reported are 1.52 and 4.57 (MPa), respectively. However, all compressive and flexural strength values lied within the limit range recommended by the “Mortars applied on walls and ceilings” construction code (i.e., ABNT NBR 13281). It is compulsory to continue the experimental tests to determine render mortars mechanical properties with higher waterproof additive-mortar weight ratios since higher ratios might produce mortars with non-allowed mechanical properties.

scholarly journals Corrugated Structure Reinforcing Aluminum Foam

2021 ◽  
Author(s):  
Massimo Durante ◽  
Luca Boccarusso ◽  
Antonio Formisano ◽  
Dario De Fazio ◽  
Antonio Viscusi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Tests ◽  
Mechanical Tests ◽  
Compression Tests ◽  
Foaming Agent ◽  
Low Weight ◽  
Optimal Value ◽  
Different Types ◽  
Potential Applications ◽  
Corrugated Structure

Metal foams have a number of established niche market and potential applications under investigation due to their peculiarities including thermal, acoustic and mechanical properties at low weight. In order to produce structures resistant at high temperature and acting as barrier to the fire, metals with closed cells are often required, and one of the most consolidate manufacturing process for their production is the gas releasing particles decomposition in semisolids, by means of which a foam is created by a foaming agent dispersed into a precursor. In previous researches, the authors have investigated the possibility of foaming the aluminum starting by a precursor, placed between two skins consisting of steel grids, in order to obtain a sandwich structure at the same time of the foaming step. In line to continue on this topic and to improve the compression strength of the aluminum-foamed core, in this work the steel grid was used both as skins and as a corrugated skeleton inside the core. Different types of sandwich structures were manufactured, following some experimental tests executed to determine the optimal value of temperature and time to foam the precursor. Then, compression tests were carried out, in order to investigate the effectiveness of the proposed solution on the improvement of this mechanical behavior. The mechanical tests highlighted the increase of mechanical properties using this type of corrugated core.

A Review on Various Methodologies for AC Duct Cleaning

2020 ◽  
Vol 07 (3&4) ◽  
pp. 1-5
Author(s):  
Soyab A Jamadar ◽  
Keyword(s):  
Air Quality ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Health Issues ◽  
Conventional System ◽  
Rectangular Shape ◽  
Inspection Robot ◽  
Different Types ◽  
Robot Systems ◽  
Articulated Robot

Cleaning of the AC ducts is the need because it creates problems such as the bad indoor air quality which results in health issues and it also causes the large maintenance of the system. The uncleaned air ducts become home for fungi, dust and harmful microbial. The causes and effects of this thing are mentioned following. The AC ducts can be cleaned through various methodologies i.e. conventional and by using robots. In the conventional system, there is manual cleaning by using some equipment. Cleaning the ducts by using robots would be a good solution for this. Different types of robot systems i.e. crawling robot, articulated robot and inspection robot are deployed for the application. There are different types of robots and their equipment according to size and type of duct. The cleaning of rectangular shape ducts is quite difficult than others. Finally, it results that cleaning ducts is the most important thing and using robots is the best methodology for it.

A Study on Polymer Particle Flow in a Disk Zone of a Screw-Disk Extruder

2014 ◽  
Vol 35 (1) ◽  
pp. 121-135 ◽  
Author(s):  
Tomasz Rydzkowski ◽  
Iwona Michalska-Pożoga
Keyword(s):  
Mechanical Properties ◽  
Computer Simulations ◽  
Particle Motion ◽  
Polymer Melt ◽  
Experimental Tests ◽  
Polymer Particle ◽  
Particle Flow ◽  
Material Particle ◽  
Motion Trajectories ◽  
Stretching Effect

Abstract The paper presents the summary of research on polymer melt particle motion trajectories in a disc zone of a screw-disk extruder. We analysed two models of its structure, different in levels of taken simplifications. The analysis includes computer simulations of material particle flow and results of experimental tests to determine the properties of the resultant extrudate. Analysis of the results shows that the motion of melt in the disk zone of a screw-disk extruder is a superposition of pressure and dragged streams. The observed trajectories of polymer particles and relations of mechanical properties and elongation of the molecular chain proved the presence of a stretching effect on polymer molecular chains.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

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