The Impact of Composition and Sintering Temperature for Stainless Steel Foams (SS316L) Fabricated by Space Holder Method with Urea as Space Holder

2017 ◽  
Vol 888 ◽  
pp. 413-417 ◽  
Author(s):  
Zulaikha Abdullah ◽  
Sufizar Ahmad ◽  
Musfirah Ramli
Keyword(s):  
Stainless Steel ◽  
Biomedical Application ◽  
Metal Foams ◽  
Morphological Properties ◽  
Solid Matrix ◽  
Morphological Observation ◽  
Second Phase ◽  
Space Holder ◽  
Closed Cell ◽  
The Impact

Metal foams are a cellular structure that has a solid matrix made of metal and has pores in their structure. Metal foams offer excellent combination of properties which led researchers interested in investigation in recent years. Closed-cell stainless steel (SS316L) foams for biomedical application were prepared by space holder method and the physical and morphological properties of SS316L foams were studied. Stainless steel (SS316L) powders as metallic material, polyethylene glycol (PEG) as a binder and Urea as a space holder material were mixed homogenously to avoid the particle wrecked. This mixture was compacted using uniaxial pressing machine and pressurized to 8 tons to formed the green body. By using tube furnace, the SS316L foams was two-stage sintered, the first phase at 600°C for 2 hours to decompose the urea, and the second phase at 1000°C, 1100°C, and 1200°C respectively to sinter the steel. The porosity and density test was carried out by applying Archimedean principles, while morphological observation was done by using Field Emission Scanning Electron (FESEM). The samples with 40wt.% SS316L composition and sintered at temperature of 1100°C, leads to porosities of about 44.539% and show the potential as the best metal foams.

scholarly journals Study on Concrete Pier Impact Performance after Implementing Equal Cross-Section Stainless Steel with Protection from Closed-Cell Aluminum Foam

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiwu Zhou ◽  
Honglong Zhang ◽  
Wenchao Zhang ◽  
Guoxue Zhang
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
Aluminum Foam ◽  
Bridge Piers ◽  
Concrete Bridge ◽  
Reinforced Concrete Bridge ◽  
Impact Forces ◽  
Closed Cell ◽  
Steel Bars ◽  
The Impact

In the present study, in order to examine the impact performances of ordinary reinforced concrete bridge piers which have been replaced by stainless-steel bars of equal cross-sections under the protective condition of anticollision material, the impact dynamic responses of the ordinary reinforced concrete bridge piers, with replacements under the protection of closed-cell aluminum foam, were compared and analyzed using an ultrahigh drop hammer impact test system. The results showed that when the impact velocity was small (for example, less than 1.42 M/s), after the implementation of equal cross-sectional replacements, the closed-cell aluminum foam had been in an elastic or yield stage. During that stage, the impact forces of the stainless-steel reinforced concrete piers were larger than those of the ordinary reinforced concrete piers, and the relative ratios were stable at approximately 28 to 34%. In addition, the relative ratios of the displacements at the tops of the components were also found to be stable at approximately 22%, and the change rates of the concrete ultrasonic damages were approximately the same. However, when the impact forces had increased (for example, more than 1.67 m/s), the closed-cell aluminum foam entered a densification stage, and the peak impact force ratios decreased sharply. It was also observed that the relative peak displacement ratios at the tops of the components displayed increasing trends, and the change rates of the concrete ultrasonic damages had displayed major flux. Therefore, the replacement of the ordinary piers with stainless-steel bars had increased the possibility of shear failures.

Polypropylene hybrid composites: Effect of reinforcement of sisal and carbon fibre on mechanical, thermal and morphological properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jyoti Agarwal ◽  
Smita Mohanty ◽  
Sanjay K Nayak
Keyword(s):  
Carbon Fibre ◽  
Mechanical Performance ◽  
Hybrid Composites ◽  
Mechanical Tests ◽  
Critical Stress Intensity Factor ◽  
Morphological Properties ◽  
Morphological Observation ◽  
Sisal Fibre ◽  
Variable Weight ◽  
The Impact

Abstract Polypropylene (PP)/sisal fibre (SF)/carbon fibre (CF) hybrid composites were prepared by melt blending process at a variable weight percentage (wt%) of carbon: sisal fibre loading (20:10, 15:15, 10:20, and 5:25). MA-g-PP (MgP) as a compatibiliser was used to improve the dispersion of the fibres within the PP matrix. The composites were subjected to mechanical tests to optimize the fibre content of CF: SF. Incorporation of 20 wt% of CF and 10 wt% of SF with 5 wt% MgP resulted in higher mechanical performance of about 67.02 and 112% over that of PP/SF composite. Similarly, the impact strength was found to be optimum which enhanced to the tune of 39.62% as compared with PP/SF composites. Halpin Tsai model was used to compare the theoretical tensile modulus of PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites with experimental evaluated values. Fracture toughness parameters such as K IC (critical stress intensity factor) and G IC (critical strain energy release rate) are determined for PP/SF/MgP composites and PP/SF/CF/MgP hybrid composites and compared by using single edge notch test. DSC study showed higher melting temperature (T m ) of PP/SF/CF/MgP composites as compared to PP revealing the enhancement in thermal stability. TGA/DTG study revealed the synergistic effect of the hybrid composite thus confirming the hybridisation effect of the system. DMA study showed that the hybridisation of CF and SF within the matrix polymer contributes to an increase in the storage modulus (Eʹ). Morphological observation by SEM confirmed that the carbon fibres and sisal fibres are well uniformly dispersed within the PP matrix, in the presence of MgP.

scholarly journals Study on the Influence of Closed-Cell Aluminum Foam on the Impact Performance of Concrete Pier after Equal Replacement with Stainless Steel Reinforcement

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xiwu Zhou ◽  
Honglong Zhang ◽  
Wenchao Zhang ◽  
Guoxue Zhang
Keyword(s):  
Stainless Steel ◽  
Aluminum Foam ◽  
Impact Test ◽  
Impact Force ◽  
Steel Reinforcement ◽  
Change Rate ◽  
Damage Rate ◽  
Closed Cell ◽  
Ultrasonic Damage ◽  
The Impact

In this study, the impact test of two groups of reinforced concrete piers protected by closed-cell aluminum foam is carried out by using the ultrahigh drop hammer impact test system. The purpose of this study is to explore the impact resistance and protective performance of closed-cell aluminum foam under the impact load on the concrete bridge pier after replacing the ordinary reinforcement with stainless steel reinforcement. The study results show that the impact force is related to the overall stiffness of the specimen, as well as to the failure mode. When the impact velocity is less than 1.42 m/s, the closed-cell aluminum foam is in an elastic or yielding stage. The change rate of impact force (231 and 97.5, respectively), tip displacement (33.5 and 18, respectively), and ultrasonic damage rate of the concrete in the two groups of specimen is relatively small, while the change rate of the two groups of specimen remains approximately consistent. In addition, when the impact is greater than 1.42 m/s and the closed-cell aluminum foam is in the densification stage, the change rate of the impact force (increase from 231 to 819 and from 97.5 to 984.5), the tip displacement (increase from 33.5 to 67 and from 18 to 62), and ultrasonic damage rate of concrete are larger, which results in an increase in the dynamic response of the structure.

INFLUENCE OF THE DIFFERENT SOIL PREPARATION METHODS ON THE PEA YIELD

2018 ◽  
pp. 16-20
Author(s):  
А. М. Grebennikov ◽  
А. S. Frid ◽  
V. P. Belobrov ◽  
V. А. Isaev ◽  
V. М. Garmashоv ◽  
...  
Keyword(s):  
Field Experiments ◽  
Morphological Properties ◽  
Mineral Fertilizers ◽  
First Year ◽  
Zero Tillage ◽  
Preparation Methods ◽  
Soil Preparation ◽  
Multifactor Analysis ◽  
The Impact ◽  
Central Chernozem

The article assesses the relationships between the morphological properties of agrochernozems and yield of peas on the plots, experience with different methods of basic treatment (moldboard plowing at the depth of 20 - 22, 25 - 27 and 14 - 16 cm, moldboard plowing to a depth of 14 - 16 cm, combined midwater moldboard, mid-water subsurface, surface to a depth of 6 - 8 cm and zero tillage) is inherent in V.V. Dokuchaev Research Institute of Agriculture of the Central Black Earth strip, in the fall of 2014. The research was conducted in 2015 - 2016, with the application of mineral fertilizers (N60Р60К60) and unfertilized background. The highest pea yields in the fertilized as the background, and without the use of fertilizers was observed in dumping plowing and especially in the variant with deep moldboard plowing, which creates in comparison with other ways of handling the best conditions for the growth and development of peas. The lowest yield of pea was obtained with zero processing. Apparently legalistic migrational-mizelial agrochernozems the Central Chernozem zone of minimum tillage in the cultivation of peas are not effective, what is evident already in the first year after the laying of experience with different basic treatments. As shown by the results of applying multifactor analysis of variance studied the mapping properties of the soil can have the same significant impact on the yield of agricultural crops, as options for the field experiments aimed at assessing the impact of various treatments on yield.

Comparative analytical study of Ashuddha Karaveera and Shuddha Karaveera

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Apeksha D. Patil ◽  
Dhiraj B. Patil
Keyword(s):  
Stainless Steel ◽  
Analytical Study ◽  
Warm Water ◽  
Foreign Matter ◽  
Steel Vessel ◽  
Mild Heat ◽  
Stainless Steel Vessel ◽  
The Impact

Karaveera (Cerebra thevetia Linn.) is reported under Upavisha Dravya in classical ayurvedic pharmacopeias. It is observed that Shodhana (purification procedures) of the mool should be carried out before its internal administration. There are different Shodhana methods mentioned in Ayurveda. In this study Godugdha was used as media. The impact of Shodhana was evaluated by physico analytical study. It clearly proves physico analytical changes during Shodhana. Ashuddha Karaveera was taken on white clean cloth and they dumped in Pottali with Godugdha. Pottali was tied to middle of wooden rod dipped in Godugdha in stainless steel vessel and mild heat given to pottali in Dolayantra. Shuddha Karaveera was obtained and then washed with leuk warm water and dried. Ashuddha Karaveera contains toxin in it which was removed after Shodhana process. So that foreign matter, loss on drying was less in Shuddha Karaveera and due to Shodhan process with Godugdha total ash, acid insoluble ash was more than that of Ashuddha Karaveera.

scholarly journals X-ray Shielding, Mechanical, Physical, and Water Absorption Properties of Wood/PVC Composites Containing Bismuth Oxide

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Attenuation Coefficient ◽  
Bismuth Oxide ◽  
Morphological Properties ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
Equivalent Thickness ◽  
X Ray ◽  
The Impact

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.

scholarly journals Does Multidisciplinary Team Simulation-Based Training Improve Obstetric Emergencies Skills?

Healthcare ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 170
Author(s):  
Encarna Hernández ◽  
Marcos Camacho ◽  
César Leal-Costa ◽  
María Ruzafa-Martínez ◽  
Antonio Jesús Ramos-Morcillo ◽  
...  
Keyword(s):  
Health Professionals ◽  
Multidisciplinary Team ◽  
Simulation Training ◽  
Observer Agreement ◽  
Second Phase ◽  
High Fidelity ◽  
Breech Delivery ◽  
Obstetric Emergencies ◽  
Quasi Experimental ◽  
The Impact

Clinical simulation in obstetrics has turned out to be a tool that can reduce the rate of perinatal morbidity and mortality. The objective of this study was to analyze the impact and evaluate the effects of training with high-fidelity simulation of obstetric emergencies on a multidisciplinary group. The quasi-experimental research study was structured in three phases: a first phase where the most important obstetric emergencies were determined, a second phase of design and development of the selected cases for simulation training, and a third and final phase where the abilities and satisfaction of the multidisciplinary team were analyzed. Three scenarios and their respective evaluation tools of obstetric emergencies were selected for simulation training: postpartum hemorrhage, shoulder dystocia, and breech delivery. The health professionals significantly improved their skills after training, and were highly satisfied with the simulation experience (p < 0.05). An inter-observer agreement between good and excellent reliability was obtained. Regarding conclusions, we can state that high-fidelity obstetric emergency simulation training improved the competencies of the health professionals.

scholarly journals Impact of Solidification on Inclusion Morphology in ESR and PESR Remelted Martensitic Stainless Steel Ingots

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 408
Author(s):  
Ewa Sjöqvist Persson ◽  
Sofia Brorson ◽  
Alec Mitchell ◽  
Pär G. Jönsson
Keyword(s):  
Stainless Steel ◽  
Martensitic Stainless Steel ◽  
Dendritic Structure ◽  
Steel Grade ◽  
Solidification Structure ◽  
Production Scale ◽  
Steel Grades ◽  
Steel Ingots ◽  
Columnar Dendritic Structure ◽  
The Impact

This study focuses on the impact of solidification on the inclusion morphologies in different sizes of production-scale electro-slag remelting (ESR) and electro-slag remelting under a protected pressure-controlled atmosphere, (PESR), ingots, in a common martensitic stainless steel grade. The investigation has been carried out to increase the knowledge of the solidification and change in inclusion morphologies during ESR and PESR remelting. In order to optimize process routes for different steel grades, it is important to define the advantages of different processes. A comparison is made between an electrode, ESR, and PESR ingots with different production-scale ingot sizes, from 400 mm square to 1050 mm in diameter. The electrode and two of the smallest ingots are from the same electrode charge. The samples are taken from both the electrode, ingots, and rolled/forged material. The solidification structure, dendrite arm spacing, chemical analyzes, and inclusion number on ingots and/or forged/rolled material are studied. The results show that the larger the ingot and the further towards the center of the ingot, the larger inclusions are found. As long as an ingot solidifies with a columnar dendritic structure (DS), the increase in inclusion number and size with ingot diameter is approximately linear. However, at the ingot size (1050 mm in diameter in this study) when the center of the ingot converts to solidification in the equiaxial mode (EQ), the increase in number and size of the inclusions is much higher. The transition between a dendritic and an equiaxial solidification in the center of the ingots in this steel grade takes place in the region between the ingot diameters of 800 and 1050 mm.

scholarly journals Strength Enhancement of Superduplex Stainless Steel Using Thermomechanical Processing

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1094
Author(s):  
M. A. Lakhdari ◽  
F. Krajcarz ◽  
J. D. Mithieux ◽  
H. P. Van Landeghem ◽  
M. Veron
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Thermomechanical Processing ◽  
Tensile Tests ◽  
Image Correlation ◽  
Strength Enhancement ◽  
Industrial Material ◽  
Superduplex Stainless Steel ◽  
The Impact ◽  
Strength Improvement

The impact of microstructure evolution on mechanical properties in superduplex stainless steel UNS S32750 (EN 1.4410) was investigated. To this end, different thermomechanical treatments were carried out in order to obtain clearly distinct duplex microstructures. Optical microscopy and scanning electron microscopy, together with texture measurements, were used to characterize the morphology and the preferred orientations of ferrite and austenite in all microstructures. Additionally, the mechanical properties were assessed by tensile tests with digital image correlation. Phase morphology was not found to significantly affect the mechanical properties and neither were phase volume fractions within 13% of the 50/50 ratio. Austenite texture was the same combined Goss/Brass texture regardless of thermomechanical processing, while ferrite texture was mainly described by α-fiber orientations. Ferrite texture and average phase spacing were found to have a notable effect on mechanical properties. One of the original microstructures of superduplex stainless steel obtained here shows a strength improvement by the order of 120 MPa over the industrial material.

scholarly journals Fragility assessment of existing low-rise steel moment-resisting frames with masonry infills under mainshock-aftershock earthquake sequences

2021 ◽  
Vol 19 (6) ◽  
pp. 2483-2504
Author(s):  
Luigi Di Sarno ◽  
Jing-Ren Wu
Keyword(s):  
Seismic Vulnerability ◽  
Steel Frames ◽  
Steel Frame ◽  
Second Phase ◽  
Moment Frames ◽  
Damage Level ◽  
Masonry Infills ◽  
Aftershock Sequences ◽  
The Impact ◽  
Multiple Earthquakes

AbstractThis paper presents the fragility assessment of non-seismically designed steel moment frames with masonry infills. The assessment considered the effects of multiple earthquakes on the damage accumulation of steel frames, which is an essential part of modern performance-based earthquake engineering. Effects of aftershocks are particularly important when examining damaged buildings and making post-quake decisions, such as tagging and retrofit strategy. The procedure proposed in the present work includes two phase assessment, which is based on incremental dynamic analyses of two refined numerical models of the case-study steel frame, i.e. with and without masonry infills, and utilises mainshock-aftershock sequences of natural earthquake records. The first phase focuses on the undamaged structure subjected to single and multiple earthquakes; the effects of masonry infills on the seismic vulnerability of the steel frame were also considered. In the second phase, aftershock fragility curves were derived to investigate the seismic vulnerability of infilled steel frames with post-mainshock damage caused by mainshocks. Comparative analyses were conducted among the mainshock-damaged structures considering three post-mainshock damage levels, including no damage. The impact of aftershocks was then discussed for each mainshock-damage level in terms of the breakpoint that marks the onset of exceeding post-mainshock damage level, as well as the probability of exceeding of superior damage level due to more significant aftershocks. The evaluation of the efficiency of commonly used intensity measures of aftershocks was also carried out as part of the second phase of assessment.

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