scholarly journals In Vitro Corrosion of Quaternery Magnesium Alloy Foam by Addition of Zinc

2020 ◽  
Vol 2 (3) ◽  
pp. 86-92
Author(s):  
Franciska Pramuji Lestari ◽  
Sofia Marta ◽  
Aprilia Erryan ◽  
Inti Mulyati ◽  
Ika Kartika
Keyword(s):  
Corrosion Rate ◽  
Raw Materials ◽  
Galvanic Corrosion ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Direct Observations ◽  
Powder Metallurgy Process ◽  
Electron Dispersion ◽  
Hank’S Solution

Magnesium alloys have been intensively studied as possible resorbable material with adequate mechanical properties similar to natural bones but very poor corrosion properties. In this analysis, the addition of Zn element to quaternary Mg-Ca-Zn alloy foam was evaluated with TiH2 as a foaming agent and manufactured with high-purity raw materials the powder metallurgy process. In Hank's solution, the rate of corrosion of specimens by direct observations with Scanning Electron Microscopy ( SEM), Electron Dispersion Spectrometry (EDS), static immersion studies, potentiodynamic evaluations, and X-Ray Diffraction (XRD). The specimens post-immersion characteristics and the corresponding Hank's solutions were examined at 2, 4, 6, 24, 48, and 72 hours of immersion. The findings show that the microstructure of alloy morphology, such as pores, pitting corrosion, needle shapes, and galvanic corrosion has the main corrosion products Mg(OH)2 and Ca10(PO4)6(OH)2. The addition of less than 6 percent wt Zn will minimize the corrosion rate but increase with 10 percent wt Zn. From this study, Mg-Zn-Ca alloy at 6 percent wt Zn has the lowest corrosion rate with slow pH changes in the process.

scholarly journals Study of Biodegradation of Pure Magnesium

2007 ◽  
Vol 342-343 ◽  
pp. 601-604 ◽  
Author(s):  
Yi Bin Ren ◽  
Hao Wang ◽  
Jing Jing Huang ◽  
Bing Chun Zhang ◽  
Ke Yang
Keyword(s):  
Corrosion Rate ◽  
Ph Value ◽  
Pure Magnesium ◽  
Hydrogen Release ◽  
Corrosion Properties ◽  
Production Of Hydrogen ◽  
New Type ◽  
Time Test ◽  
Hank’S Solution

Magnesium and its alloys are possible to develop new type of biodegradable medical magnesium alloys by using their active corrosion potential. The bio-corrosion properties of the high pure magnesium in the Hank’s solution were investigated in this paper, the results showed that high pure magnesium had a low corrosion rate and hydrogen release in Hank’s solution, when the pH value of solution was controlled at 7.5, the corrosion rate was under 0.2mm/year, the production of hydrogen was about 0.15ml/cm2, and if the solution wasn’t controlled on pH value, the corrosion rate was about 0.02 mm/year, production of hydrogen was about 0.1ml/cm2 . Result of in vitro Kinetic clotting time test and animal implant prep-test showed that High pure magnesium had good thromboresistant property and tissue compatibility, pure magnesium can biodegrade lowly in animal body and formed surface apatite, which proportion of Ca/P was similar with bone tissue.

Preparation and Properties of Chitosan-Tranexamic Acid Salts

2019 ◽  
Vol 943 ◽  
pp. 129-134 ◽  
Author(s):  
Zhang Hu ◽  
Ya Qi Qin ◽  
Si Tong Lu ◽  
Chu Ru Huang ◽  
Ze Kun Chen
Keyword(s):  
Tranexamic Acid ◽  
Water Solubility ◽  
Raw Materials ◽  
Test Tube ◽  
X Ray Diffraction ◽  
Crystallinity Degree ◽  
Protonation Reaction ◽  
Coagulant Activity ◽  
Acid Salts

The solid chitosan-tranexamic acid salts were successfully prepared by the method of half-wet grinding with chitosan and tranexamic acid as raw materials. The physical properties including water solubility and stability of the prepared samples were tested, and their structures were characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). In addition, the in vitro pro-coagulant activity was evaluated by the test tube method. The results showed that the prepared chitosan-tranexamic acid salts could be dissolved in weak acidic, neutral and weak alkaline aqueous solutions, expanding the dissolution range. The characterization results indicated that the protonation reaction of the chitosan amino group was achieved without solvent and the crystallinity degree of chitosan-tranexamic acid salts decreased by comparison with chitosan. The hemostasis evaluation showed that chitosan-tranexamic acid salts with different mass ratios had pro-coagulant activities in vitro. In particular, the clotting time of chitosan acid salt with mass ratio of 1:2 was shorter than that of Yunnan Baiyao. This effort laid the foundation for the development of the promising chitosan-based hemostatic materials.

A novel Mg-Sn-Zn-Al-Mn magnesium alloy with superior corrosion properties

2021 ◽  
Vol 118 (5) ◽  
pp. 504
Author(s):  
Ali Ercetin
Keyword(s):  
Protective Layer ◽  
Xrd Analysis ◽  
Production Method ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Alloying Element ◽  
Corrosion Properties ◽  
Corrosion Behaviors ◽  
Element Addition ◽  
Hank’S Solution

The corrosion behaviors of the hot-pressed Mg-Sn-Zn-Al-Mn magnesium alloys with the addition of Al in different proportions have been investigated. Paraffin coating technique was applied to Mg powders before production. After debinding at 300 °C, the sintering process was applied at 610 °C under 50 MPa pressure for 70 min. All of the alloys were immersed in Hank’s solution for 10-days. The results indicated that the corrosion properties of the alloys were affected by the production method (hot pressing) and alloying element addition. After immersion, magnesium hydroxide (Mg(OH)2), hydroxyapatite (HA), and Mg-Al hydrotalcite structures were determined by the X-ray diffraction (XRD) analysis on the surfaces of Mg-Sn-Zn-Al-Mn alloys. The Mg-Al hydrotalcite protective layer was effective in preventing corrosion. Superior corrosion properties (weight loss: 1.2%, total volume of evolved H2 gas: 4 ml/cm2, corrosion rate: 0.39 mm/year) were obtained from TZAM5420 alloy (5 wt.%Sn, 4 wt.%Zn, 2 wt.%Al, 0.2 wt.%Mn).

scholarly journals Corrosion Behavior of L245N Standard Steel in CO2 Saturated Brine under Flow Condition

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 880
Author(s):  
Ying Hu ◽  
Long Xin ◽  
Tingguang Liu ◽  
Yonghao Lu
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Galvanic Corrosion ◽  
Morphological Characteristics ◽  
X Ray Diffraction ◽  
Slow Increase ◽  
Corrosion Scale ◽  
The One ◽  
Standard Steel

The corrosion behavior of oilfield used L245N standard steel was tested in simulated oilfield solution by dynamic high-temperature autoclave. The corrosion products were characterized by using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Electrochemical impedance spectroscopy (EIS) respectively. In addition, the corrosion rates and surface morphological characteristics of the steels after different exposure times were studied. The results showed that the corrosion rate decreased sharply and then increased with time in the high salinity flow solution, which was related to the formation of corrosion scale and the remaining cementite within it. At the beginning of the exposure time, the formed corrosion scale became thicker, resulting in a significant decrease of the corrosion rate. While with increasing time, on the one hand, the increased remaining cementite within corrosion scale facilitated the corrosion by the galvanic corrosion between the remaining cementite and the ferrite within the metal. On the other hand, the protective effect of corrosion scale formed on the remaining cementite skeleton declined due to the formation of large amounts of FexCa1−xCO3, which also promoted the corrosion rate of the steels, both these ways contributed to a slow increase of corrosion rate.

scholarly journals Tribological performance and corrosion behavior of CoCrMo alloy

2021 ◽  
Vol 16 (59) ◽  
pp. 129-140
Author(s):  
Hadda Rezzag ◽  
Latifa Kahloul ◽  
Hacène Chadli ◽  
Alima Mebrek ◽  
Adel Saoudi
Keyword(s):  
Corrosion Behavior ◽  
Positive Impact ◽  
X Ray Diffraction ◽  
Cocrmo Alloy ◽  
Electrochemical Tests ◽  
Powder Metallurgy Process ◽  
Lower Corrosion Rate ◽  
Hank’S Solution ◽  
Metallurgy Process ◽  
Cocrmo Alloys

The present work focuses on the Tribological properties and corrosion behavior evaluation of sintered CoCrMo alloy. The CoCrMo alloy was elaborated by Powder metallurgy process at various sintering temperatures (1200°C, 1250°C and 1300°C). The structural properties were characterized by X-ray diffraction and scanning electron microscopy. The tribological characteristics were measured using a dry disc-ball tribometer. The corrosion behavior of the samples was studied using different electrochemical tests in a simulated physiological environment (Hank’s solution). The obtained results show that higher sintering temperatures have a positive impact on the tribological behavior as well as the corrosion resistance of CoCrMo alloys. The sintered samples at 1300°C showed a better resistance to friction wear and a lower corrosion rate.

The native structure of the eukaryotic ribosome

1983 ◽  
Vol 41 ◽  
pp. 432-433
Author(s):  
R.A. Milligan ◽  
P.N.T. Unwin
Keyword(s):  
Ribosomal Proteins ◽  
Crystal Form ◽  
Native Structure ◽  
X Ray Diffraction ◽  
Eukaryotic Ribosome ◽  
Vitro Analysis ◽  
In Vitro Analysis ◽  
Resolution Structure ◽  
Stable Unit

A detailed understanding of the mechanism of protein synthesis will ultimately depend on knowledge of the native structure of the ribosome. Towards this end we have investigated the low resolution structure of the eukaryotic ribosome embedded in frozen buffer, making use of a system in which the ribosomes crystallize naturally.The ribosomes in the cells of early chicken embryos form crystalline arrays when the embryos are cooled at 4°C. We have developed methods to isolate the stable unit of these arrays, the ribosome tetramer, and have determined conditions for the growth of two-dimensional crystals in vitro, Analysis of the proteins in the crystals by 2-D gel electrophoresis demonstrates the presence of all ribosomal proteins normally found in polysomes. There are in addition, four proteins which may facilitate crystallization. The crystals are built from two oppositely facing P4 layers and the predominant crystal form, accounting for >80% of the crystals, has the tetragonal space group P4212, X-ray diffraction of crystal pellets demonstrates that crystalline order extends to ~ 60Å.

In Vitro Assessment of Hydroxyapatite Coating on the Surface of Additive Manufactured Ti6Al4V Scaffolds

2016 ◽  
Vol 879 ◽  
pp. 2444-2449 ◽  
Author(s):  
Ekaterina Chudinova ◽  
Maria Surmeneva ◽  
Andrey Koptioug ◽  
Irina V. Savintseva ◽  
Irina Selezneva ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Human Mesenchymal Stem Cells ◽  
Nanocrystalline Structure ◽  
X Ray Diffraction ◽  
Ha Coating ◽  
Magnetron Sputter Deposition ◽  
In Vitro Assessment ◽  
Average Size

Custom orthopedic and dental implants may be fabricated by additive manufacturing (AM), for example using electron beam melting technology. This study is focused on the modification of the surface of Ti6Al4V alloy coin-like scaffolds fabricated via AM technology (EBM®) by radio frequency (RF) magnetron sputter deposition of hydroxyapatite (HA) coating. The scaffolds with HA coating were characterized by Scanning Electron microscopy, X-ray diffraction. HA coating showed a nanocrystalline structure with the crystallites of an average size of 32±9 nm. The ability of the surface to support adhesion and the proliferation of human mesenchymal stem cells was studied using biological short-term tests in vitro. In according to in vitro assessment, thin HA coating stimulated the attachment and proliferation of cells. Human mesenchymal stem cells cultured on the HA-coated scaffold also formed mineralized nodules.

scholarly journals Waste and Solar Energy: An Eco-Friendly Way for Glass Melting

2021 ◽  
Vol 5 (2) ◽  
pp. 16
Author(s):  
Isabel Padilla ◽  
Maximina Romero ◽  
José I. Robla ◽  
Aurora López-Delgado
Keyword(s):  
Solar Energy ◽  
Environmental Sustainability ◽  
Raw Materials ◽  
Glass Melting ◽  
Glass Network ◽  
X Ray Diffraction ◽  
X Ray ◽  
Concentrated Solar Energy ◽  
Calcium Source ◽  
The Aluminum Industry

In this work, concentrated solar energy (CSE) was applied to an energy-intensive process such as the vitrification of waste with the aim of manufacturing glasses. Different types of waste were used as raw materials: a hazardous waste from the aluminum industry as aluminum source; two residues from the food industry (eggshell and mussel shell) and dolomite ore as calcium source; quartz sand was also employed as glass network former. The use of CSE allowed obtaining glasses in the SiO2-Al2O3-CaO system at exposure time as short as 15 min. The raw materials, their mixtures, and the resulting glasses were characterized by means of X-ray fluorescence, X-ray diffraction, and differential thermal analysis. The feasibility of combining a renewable energy, as solar energy and different waste for the manufacture of glasses, would highly contribute to circular economy and environmental sustainability.

scholarly journals Direct observations of shock-induced melting in a porous solid using time-resolved x-ray diffraction

2020 ◽  
Vol 4 (6) ◽  
Author(s):  
A. Mandal ◽  
B. J. Jensen ◽  
M. C. Hudspeth ◽  
S. Root ◽  
R. S. Crum ◽  
...  
Keyword(s):  
Porous Solid ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Direct Observations

scholarly journals Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3474
Author(s):  
Katarzyna Uram ◽  
Milena Leszczyńska ◽  
Aleksander Prociak ◽  
Anna Czajka ◽  
Michał Gloc ◽  
...  
Keyword(s):  
Cross Sections ◽  
Raw Materials ◽  
Polyurethane Foams ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Polyurethane Composite ◽  
Composite Foams ◽  
Closed Cell ◽  
Ft Ir ◽  
The Fourier Transform

Rigid polyurethane foams were obtained using two types of renewable raw materials: bio-polyols and a cellulose filler (ARBOCEL® P 4000 X, JRS Rettenmaier, Rosenberg, Germany). A polyurethane system containing 40 wt.% of rapeseed oil-based polyols was modified with the cellulose filler in amounts of 1, 2, and 3 php (per hundred polyols). The cellulose was incorporated into the polyol premix as filler dispersion in a petrochemical polyol made using calenders. The cellulose filler was examined in terms of the degree of crystallinity using the powder X-ray diffraction PXRD -and the presence of bonds by means of the fourier transform infrared spectroscopy FT-IR. It was found that the addition of the cellulose filler increased the number of cells in the foams in both cross-sections—parallel and perpendicular to the direction of the foam growth—while reducing the sizes of those cells. Additionally, the foams had closed cell contents of more than 90% and initial thermal conductivity coefficients of 24.8 mW/m∙K. The insulation materials were dimensionally stable, especially at temperatures close to 0 °C, which qualifies them for use as insulation at low temperatures.

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