scholarly journals Studying of 2D Titanium Carbide Structure by Raman Spectroscopy after Heat Treatment in Argon and Hydrogen Atmospheres

2017 ◽  
Vol 19 (2) ◽  
pp. 181 ◽  
Author(s):  
Olzhas Kaipoldayev ◽  
Ye. Mukhametkarimov ◽  
Renata Nemkaeva ◽  
G. Baigarinova ◽  
Madi Aitzhanov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Titanium Carbide ◽  
Functional Groups ◽  
Optimal Regime ◽  
Heat Treated ◽  
Initial Oxygen Content ◽  
Initial Oxygen ◽  
Tio2 Rutile ◽  
Total Disappearance

Herein we show the effect of heat treatment of two dimensional layered titanium carbide structure (Ti3C2Tx), so called MXene. As prepared MXene has functional groups -OH, -F, -Cl. In order to remove the functional groups we heat treated the MXene in Ar (with 0.01% O2) and H2 (with 0.01% H2O) atmospheres. We discovered the significant decrease in the amount of functional groups (-F and -Cl) and increase in the -O content, which refers to the oxidation of the material. Also we determined the optimal regime for Raman spectroscopy in order to avoid any changes in the structure of the material. We revealed that titanium carbide changes its structure at 700 °C and 900 °C into two different titanium dioxide modifications like rutile and anatase in Ar (with 0.01% O2) atmosphere. Also there are small changes occurred in Ti3C2Tx structure and formation of amorphous carbon after 700 °C treatment in H2 (with 0.01% H2O) atmosphere and formation of TiO2 (rutile) at 900 °C. Energydispersive X-ray spectroscopy (EDX) revealed the reduction of functional groups at 700 °C in both atmospheres and total disappearance of –F and –Cl and increasing the oxygen at 900 °C. The huge increase of oxygen by atomic percent, can be explained by the initial oxygen content in argon and hydrogen gases.

Study of Raman Spectroscopy on Graphene Phase from Heat Treatment of Coconut (Cocus nucifera) Shell

2015 ◽  
Vol 827 ◽  
pp. 290-293 ◽  
Author(s):  
Fandi Angga Prasetya ◽  
Muhammad Nasrullah ◽  
Ananda Yogi Nugraheni ◽  
Darminto
Keyword(s):  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Atmospheric Condition ◽  
Peak Position ◽  
Special Treatment ◽  
Distilled Water ◽  
X Ray ◽  
Heat Treated ◽  
Reduced Graphene ◽  
Two Samples

Coconut (Cocus Nucifera) shell as the main ingredient in this research has been heat-treated at temperature of 1000°C in atmospheric condition aiming to obtain the expected phase of graphene. After heat treatment, an additional special treatment was given, where sample was then rinsed with distilled water. Furthermore, the heated coconut shell was characterized by Raman Spectroscopy (785 nm) and X-ray diffractometry. Based on the treatment and characterization conducted, all samples were likely to contain reduced graphene oxide (RGO) phase.The XRD data have supported the existence of RGO with the diffraction peak position (2q) at 25o and 45o. Evidence is also given by the result of Raman Spectroscopy which produces peaks (denoted by D and G bands) located at wave numbers of 1300 cm-1 and 1590 cm-1. The value of the ratio ID/IG of the two samples in the figures are 2.6 and 2.51 (matched with ratio ID/IG of RGO). The ID/IG ratio of sample which was rinsed by distilled water is higher that those without rinsing treatment.

Platinum-TiO2 (Rutile) Substrate Interaction During Cyclic Oxidation-Reduction Heat-Treatment

1981 ◽  
Vol 39 ◽  
pp. 72-73
Author(s):  
S. Shinozaki ◽  
W. T. Donlon ◽  
A. H. Meitzler
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Treatment Procedure ◽  
Substrate Interaction ◽  
Reducing Atmosphere ◽  
Oxidation Reduction ◽  
Heat Treated ◽  
Pt Electrodes ◽  
The Matrix ◽  
Tio2 Rutile

When polycrystalline TiO2 (rutile) pellets (∼1mm in thickness and ∼3 mm in diameter), dispersed with Pt particles to act as a catalyst, were heat-treated under certain conditions involving an applied electric field, new unusual microstructures were formed. The heat-treatment procedure was, as follows: 1) apply 1 volt dc field between two Pt electrodes inbedded into the pellet, 2) heat the sample to 750°C and begin cycling the sample between oxydizing (4% O2 in N2) and reducing (2% CO in N2) atmospheres at a rate of several cycles per hour, 3) lower the temperature to 600°C while continually cycling (200 cycle), and, 4) cool the sample to room temperature under the reducing atmosphere (1). The pellet was ion milled to a proper electron transparency and examined by means of a Siemens EM102 and a Philips EM400 TEM-STEM microscope.Some TiO2 grains in this sample exhibited no resolvable defect structure, except that the matrix appeared to be strained due to small defects (Fig. la).

scholarly journals Kinetics of Germination of Wet-Heat-Treated Individual Spores of Bacillus Species, Monitored by Raman Spectroscopy and Differential Interference Contrast Microscopy

2011 ◽  
Vol 77 (10) ◽  
pp. 3368-3379 ◽  
Author(s):  
Guiwen Wang ◽  
Pengfei Zhang ◽  
Peter Setlow ◽  
Yong-qing Li
Keyword(s):  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Spore Germination ◽  
Great Majority ◽  
Lytic Enzyme ◽  
Differential Interference Contrast ◽  
Content Type ◽  
Heat Treated ◽  
Wet Heat ◽  
Kinetics Of

ABSTRACTRaman spectroscopy and differential interference contrast (DIC) microscopy were used to monitor the kinetics of nutrient and nonnutrient germination of multiple individual untreated and wet-heat-treated spores ofBacillus cereusandBacillus megaterium, as well as of several isogenicBacillus subtilisstrains. Major conclusions from this work were as follows. (i) More than 90% of these spores were nonculturable but retained their 1:1 chelate of Ca2+and dipicolinic acid (CaDPA) when incubated in water at 80 to 95°C for 5 to 30 min. (ii) Wet-heat treatment significantly increased the time,Tlag, at which spores began release of the great majority of their CaDPA during the germination ofB. subtilisspores with different nutrient germinants and also increased the variability ofTlagvalues. (iii) The time period, ΔTrelease, betweenTlagand the time,Trelease, at which a spore germinating with nutrients completed the release of the great majority of its CaDPA, was also increased in wet-heat-treated spores. (iv) Wet-heat-treated spores germinating with nutrients had higher values ofIrelease, the intensity of a spore's DIC image atTrelease, than did untreated spores and had much longer time periods, ΔTlys, for the reduction inIreleaseintensities to the basal value due to hydrolysis of the spore's peptidoglycan cortex, probably due at least in part to damage to the cortex-lytic enzyme CwlJ. (v) Increases inTlagand ΔTreleasewere also observed when wet-heat-treatedB. subtilisspores were germinated with the nonnutrient dodecylamine, while the change inIreleasewas less significant. (vi) The effects of wet-heat treatment on nutrient germination ofB. cereusandB. megateriumspores were generally similar to those onB. subtilisspores. These results indicate that (i) some proteins important in spore germination are damaged by wet-heat treatment, (ii) the cortex-lytic enzyme CwlJ is one germination protein damaged by wet heat, and (iii) the CaDPA release process itself seems likely to be the target of wet-heat damage which has the greatest effect on spore germination.

The Behavior of Oxygen and Defects in Si-Based Semiconductor Studied by Positron Annihilation Techniques

2008 ◽  
Vol 607 ◽  
pp. 131-133
Author(s):  
Wen Deng ◽  
Le Huang ◽  
Qi Tao Zhu ◽  
Ya Qin Wei ◽  
Yu Yang Huang
Keyword(s):  
Heat Treatment ◽  
Structural Changes ◽  
Positron Beam ◽  
Sio2 Film ◽  
Doppler Broadening ◽  
Slow Positron ◽  
Initial Oxygen Content ◽  
Initial Oxygen ◽  
One Step ◽  
Induced Defects

Slow positron beam and coincidence Doppler broadening techniques have been used to follow temperature-induced defects and structural changes in Cz-Si with an initial oxygen content of 1.1×1018 cm-3. Oxygen is recognized as a peak at about 11.85×10-3m0c on the ratio curves. For Cz-Si annealed at 480 oC/15h or 600 oC/15h, the ratio curves show the presence of vacancy-like defects, but they are not associated with oxygen. For Cz-Si annealed at 480 oC/15h, then followed by a 600 oC/15h heat treatment, the ratio curves show the signal of O atom. The ratio curves of Cz-Si, thermally treated by a two-step (480oC/15h + 600oC/15h) pre-annealing, followed by a one-step annealing under different hydrostatic argon pressures and annealed temperatures, also show a peak at 11.85×10-3m0c. The height of the peak varies with different samples. Experimental results indicate that the SiO2 film will form on the surface of Cz-Si after the heat treatment.

Production of Stainless Cast Iron Base Deposits with Dispersed Titanium Carbide Particles by Plasma Spraying

2010 ◽  
Vol 654-656 ◽  
pp. 1888-1891 ◽  
Author(s):  
Yasuhiro Hoshiyama ◽  
Tsutomu Miyazaki ◽  
Hidekazu Miyake
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Titanium Carbide ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Iron Base ◽  
Heat Treated ◽  
Plasma Sprayed ◽  
Carbide Particles

Fe-C-Ti-Cr-Ni alloy powder in diameter of 32-53 μm made by argon atomization is low-pressure plasma sprayed to produce stainless cast iron base deposits with finely dispersed titanium carbide particles. The as-sprayed deposit formed on a water-cooled substrate consists of γFe, αFe, TiC and Cr3C2. Heat treatment of the as-sprayed deposit above 873 K results in the formation of Cr7C3. The fine precipitates of approximately 0.2 μm in the as-sprayed deposit formed on a water-cooled substrate are carbide. The as-sprayed deposit produced on a non-cooled substrate and deposits which are obtained by heat treatment of the as-sprayed deposit are composed of γFe, αFe, TiC, Cr3C2 and Cr7C3. As heat treatment temperature increases, carbide precipitates coarsen. The hardness of deposit decreases with increasing heat treatment temperature. The wear resistance of as-sprayed deposit formed on a non-cooled substrate was higher than that of the deposit heat-treated at 1273 K. The as-sprayed deposit and deposit heat-treated at 1273 K have higher wear resistance than a commercial stainless steel.

Effect of Thermal Treatment on Bioactivity of Experimental Dental Cement

2017 ◽  
Author(s):  
Svitlana Fialkova ◽  
Jair Flores ◽  
Sergey Yarmolenko ◽  
Jagannathan Sankar ◽  
Geoffrey Ndungu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Dwell Time ◽  
Dental Cement ◽  
X Ray ◽  
Micro Raman Spectroscopy ◽  
Heat Treated

Objective. The purpose of this study was to characterize and to evaluate the effect of thermal treatment on properties and bioactivity of experimental dental cement. Methods. Specimens of the dental cement (pellets 13 mm in diameter × 3 mm thick) were prepared by cold pressing of micronized powder of set Alborg White Portland cement. The thermo-gravimetric analysis and differential scanning calorimetry (TGA/DSC) were used to analyze the phase composition and determine the transition temperatures for sintering process. The effect of heat rate and dwell time on density, crystal morphologies, crystalline phases and elemental composition of cement was evaluated by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and micro-Raman spectroscopy. The bioactivity of set and heat-treated cements was evaluated by ability produce the hydroxyapatite (HA) layer on a surface of specimen immersed in a simulated body fluid (Dulbecco’s Phosphate-Buffered Saline (DPBS). The formation of hydroxyapatite was confirmed by SEM, X-ray energy dispersive spectroscopy (EDS), XRD and and micro-Raman spectroscopy. The amount of produced HA was measured by weight method after 1, 3, 7, and 14 days of immersion. Results. The set of samples were sintered from experimental dental cement at various heating rate and dwell time. The highest density was obtained at slower heating rate and longer dwell time. The heat treatment changes the hydration phases without changing elemental composition. The heat treatment significantly improves biological performance of dental cement. The heat-treated cement produces 10 times more HA with immersion into simulated body fluid.

Effects of Ingredients and Post-Heat Treatment on Phase Transformation and Structure of Bioactive Composite Coatings

2007 ◽  
Vol 280-283 ◽  
pp. 1619-1622
Author(s):  
Mu Qin Li ◽  
Da Shan Shang ◽  
Chen Ma ◽  
Shi Qin Yang
Keyword(s):  
Heat Treatment ◽  
Phase Transformation ◽  
Phase Composition ◽  
Composite Coatings ◽  
Thermal Spraying ◽  
Post Heat Treatment ◽  
Working Layer ◽  
Structure Changes ◽  
Heat Treated ◽  
Tio2 Rutile

Bioactive composite coatings containing sub-layer and working-layer with different ingredients were prepared using subsonic thermal spraying technology and then heat-treated at 700°C for 1h. Two types of bioglasses, named BG1 and BG2, and Y2O3 were used as additives of the sublayer and working layer respectively. Phase transformation and structure changes of the coatings were investigated with XRD, DSC and SEM. Results showed that the phases of as-sprayed Ti/BG1 sub-layer were TiN, TiO2 (rutile and anatase), etc. Post-heat treatment changed the phase composition. TiN and anatase transformed into rutile and some new phases generated, which often enriched at pores and cracks. In the working-layer, part of nano-hydroxyapatite powders decomposed during coating preparation. Y2O3 impaired the decomposition to some extent and BG2 enhanced greatly. Post-heat treatment increased the crystallinity of all coatings effectively. The analysis of TG-DSC showed that BG2 added in working-layer crystallized at 700°

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3077-3089
Author(s):  
Alexeis Sánchez ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
I. Mejía
Keyword(s):  
Heat Treatment ◽  
Abrasive Wear ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Wear Behaviour ◽  
White Iron ◽  
Heat Treated ◽  
Bulk Hardness ◽  
Abrasive Wear Behavior ◽  
Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

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