Hydrides Effect on the SCC Initiation on Zircaloy-4 Claddings

2007 ◽  
Vol 23 ◽  
pp. 249-252
Author(s):  
Alice Dinu ◽  
M. Radulescu ◽  
D. Ionescu ◽  
Silviu Florea
Keyword(s):  
Radial Direction ◽  
Zirconium Hydride ◽  
Simultaneous Action ◽  
Thermal Treatments ◽  
Corrosive Environment ◽  
Metallographic Method ◽  
Before And After ◽  
Cause Of Failure ◽  
Different Content ◽  
Type Fuel

The main cause of failure of CANDU-type fuel bundles during their operation is the Stress Corrosion Cracking (SCC). This mechanism appears in presence of the simultaneous action of a corrosive agent and of mechanical stress. The presence of precipitated zirconium hydride platelets can affect the propagation of the SCC cracks. For this reason, we studied the influence of content of hydrogen on the initiation and the propagation of SCC crack. To do this study, some Crings samples with different content of hydrogen (100-500ppm) were exposed in a corrosive environment containing iodine (10-4g/cm2) at 320°C. The stress state, the concentration of the corrosive environment and the temperature were maintained constant. For comparison, in the same conditions some as-received samples were exposed. To relieve the morphology of the precipitates of the zirconium hydride the samples were been investigated using metallographic method, before and after thermal treatments. While before the experiment a circumferential orientation of the hydrides precipitates was observed, after the thermal treatments a reorientation of hydrides in a radial direction was been remarked. Investigation by SEM method revealed the propagation modes of cracks in the case of the as-received samples and it was put in evidence the existence of the microcracks on the inner surface of tested samples.

Application of Thermo-Frictional and Chemical-Thermal Methods Treatments for Surface Strengthening of Materials

2021 ◽  
Vol 1038 ◽  
pp. 93-99
Author(s):  
Alexander Levterov ◽  
Julia Nechitailo ◽  
Tatyana Plugina ◽  
Oleg Volkov
Keyword(s):  
Cross Sections ◽  
Experimental Studies ◽  
Metallographic Analysis ◽  
Thermal Treatments ◽  
Strengthening Effect ◽  
Thermal Methods ◽  
Surface Strengthening ◽  
Before And After ◽  
The Cross

In the article, the issues of using the methods of thermo-frictional and chemical-thermal treatments for surface strengthening of steel tools were disclosed. 65G steel and U8A steel were considered. A flat graver and a cylindrical root roller were considered to be tools in need of hardening. The nature of the jewellery work using such a tool has been described. Hardening techniques, experimental studies and macro photographs of the samples were presented in this article. A detailed metallographic analysis and measurement of the microhardness of the cross-sections of the prototypes after their strengthening using various methods was carried out. The metallographic nature of the reinforcement with the formation of surface "white layers" was shown. Comparison of the properties of the samples before and after strengthening was carried out. Conclusions about the strengthening effect of the thermo-frictional and chemical-thermal methods of strengthening were made.

scholarly journals Laser Irradiation of a Bio-Waste Derived Carbon Unlocks Performance Enhancement in Secondary Lithium Batteries

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3183
Author(s):  
Mariangela Curcio ◽  
Sergio Brutti ◽  
Lorenzo Caripoti ◽  
Angela De Bonis ◽  
Roberto Teghil
Keyword(s):  
Laser Irradiation ◽  
Performance Enhancement ◽  
Laser Source ◽  
Thermal Treatments ◽  
Carbon Particles ◽  
Nanosecond Pulsed Laser ◽  
Negative Electrodes ◽  
Before And After ◽  
Hazelnut Shell ◽  
Compositional Changes

Pyrolyzed carbons from bio-waste sources are renewable nanomaterials for sustainable negative electrodes in Li- and Na-ion batteries. Here, carbon derived from a hazelnut shell has been obtained by hydrothermal processing of the bio-waste followed by thermal treatments and laser irradiation in liquid. A non-focused nanosecond pulsed laser source has been used to irradiate pyrolyzed carbon particles suspended in acetonitrile to modify the surface and morphology. Morphological, structural, and compositional changes have been investigated by microscopy, spectroscopy, and diffraction to compare the materials properties after thermal treatments as well as before and after the irradiation. Laser irradiation in acetonitrile induces remarkable alteration in the nanomorphology, increase in the surface area and nitrogen enrichment of the carbon surfaces. These materials alterations are beneficial for the electrochemical performance in lithium half cells as proved by galvanostatic cycling at room temperature.

Atomic Force And Scanning Electron Microscopy Of Corrosion And Fatigue Of An Aluminum-Copper Alloy

1995 ◽  
Vol 409 ◽  
Author(s):  
K. Kowal ◽  
J. DeLuccia ◽  
J.Y. Josefowicz ◽  
C. Laird ◽  
G.C. Farrington
Keyword(s):  
Fatigue Life ◽  
Crack Nucleation ◽  
Mechanical Deformation ◽  
Simultaneous Action ◽  
Second Phase ◽  
Corrosive Environment ◽  
Intergranular Cracking ◽  
Early Stages ◽  
Atomic Force ◽  
Persistent Slip Bands

AbstractThe morphological features of 2024-T3 aluminum alloy were delineated using atomic force microscopy (AFM) during separate and combined actions of corrosion and fatigue.In-situ AFM corrosion studies in hydrochloric acid environments without mechanical deformation showed accelerated dissolution in the vicinity of second phase precipitates leading to intergranular corrosion. During fatigue in air, AFM images revealed steps along grain boundaries, as well as parallel extrusions and intrusions during the early stages of fatigue life. At later stages of mechanical deformation persistent slip bands (PSBs) were observed on the sample's surface. Cracks were observed to nucleate and propagate along PSBs. For experiments where samples were subjected to the simultaneous action of a corrosive environment and mechanical deformation, intergranular cracking was observed during the early stages of fatigue life. The corrosive environment was observed to accelerate the crack nucleation process.

scholarly journals Effect of thermosonication on enzymatic oxidation and physicochemical properties of soursop (Annona muricata) pulp

2021 ◽  
Vol 53 (2) ◽  
pp. 252-260
Author(s):  
Victor Manuel Gelvez Ordóñez ◽  
Ivan Daniel López Castilla ◽  
Luis Eduardo Ordoñez-Santos
Keyword(s):  
Vitamin C ◽  
Physicochemical Properties ◽  
Soluble Solids ◽  
Enzymatic Oxidation ◽  
Thermal Treatments ◽  
Tropical Fruit ◽  
The Us ◽  
Before And After ◽  
Partial Inactivation ◽  
Internal Consumption

Soursop is an exotic tropical fruit, highly perishable, presents losses around 30% in postharvest, has marked commercial importance especially for internal consumption and a maximum shelf life. The objective of the present work was to study the effect of thermosonication (TS) on some physicochemical properties and the enzymatic oxidation of soursop pulp. The thermosonication treatments used on the samples were at 40 kHz, in a temperature range between 20-60 ºC, for 25 minutes. The soluble solids, pH, vitamin C concentration, inactivation of peroxidase (POD) and polyphenoloxidase (PPO) in the soursop pulp were evaluated before and after the treatments. The results indicate a loss of vitamin C was observed in a 2.63; 13.16 and 28.95% for temperatures at 20, 40 and 60 ºC, respectively. On the other hand, a partial inactivation of the enzymes, POD, in 48.41; 69.83 and 74.24% and for PPO in 56.38; 74.47 and 81.91% was achieved at temperatures at 20, 40 and 60 ºC respectively. Finally, it was demonstrated that the US combined with heat (TS) inactivates in a large percentage the POD and PPO enzymes in the soursop pulp needing less heat, which could make it more efficient in comparison with the thermal treatments. Highlights Ultrasound combined with heat (TS) can inactivate POD and PPO enzymes in the soursop pulp, achieving considerable retention of vitamin C. Peroxidase (POD) and Polyphenoloxidase (PPO) trigger enzymatic processes affecting product natural color. Soursop is an exotic fruit with high levels of bioactive compounds, and great agro-industrial potential given its high recovery yields and excellent sensory characteristics. A vitamin C retention level of 71.05- to 86.84% was achieved in soursop pulps that have undergone thermosonification.

Effect of the Type of Adhesives on the Properties of Multilayer Packaging Material Based on PET/AlOx Film with Acrylic Coating before and after the Sterilization Process

2021 ◽  
Vol 899 ◽  
pp. 104-109
Author(s):  
Iskander Muratov ◽  
Ruslan Garipov ◽  
Anna Efremova
Keyword(s):  
Chemical Nature ◽  
Packaging Material ◽  
Packaging Materials ◽  
Acrylic Coating ◽  
Adhesive Compositions ◽  
Before And After ◽  
Reactive Groups ◽  
Sterilization Process ◽  
Seal Strength ◽  
Different Content

In this work the properties of multilayer packaging materials based on PET/AlOx film with acrylic coating were studied. Multilayer packaging materials were produced on industrial laminators using three different adhesive compositions with different content of reactive groups. It is shown that the peculiarity of the chemical nature of adhesive components affects the bond strength and the seal strength of multilayer packaging materials.

Quantitative assessment of German Holstein dairy cattle colostrum and impact of thermal treatment on quality of colostrum viscosity and immunoglobulins

2020 ◽  
Author(s):  
Abdulwahed Ahmed Hassan ◽  
Sebastian Ganz ◽  
Florian Schneider ◽  
Axel Wehrend ◽  
Izhar U.H. Khan ◽  
...  
Keyword(s):  
Refractive Index ◽  
Dairy Cattle ◽  
Dynamic Viscosity ◽  
Correlation Coefficients ◽  
Thermal Treatments ◽  
Heat Treated ◽  
Before And After ◽  
C 30 ◽  
The Impact

Abstract Objective: This study aimed to determine the color, fat, viscosity, IgG concentration, %Brix and refractive index of fresh postpartum colostrum of German Holstein dairy cattle and assess the impact of different thermal treatments on the visual and dynamic viscosity, in association to IgG concentration, of colostrum that can be used for pasteurization process. Results: Of the total 40 fresh postpartum colostrum, the color of colostrum (white-pale yellow to yellow and dark-yellowish), fat (1.4 - 8.2 100 g-1), IgG (4 - 116 mg mL-1), %Brix (8.5 - 35.4%), refractive index (1.3454 - 1.3905 nD), visual (ranging from watery to liquid and thick) and dynamic (4.9 - 219 cp) viscosity, were recorded. Statistical analysis between visual and dynamic viscosity of fresh colostrum showed significant correlation coefficients (rs = 634). Moreover, a significant correlation between viscosity and three IgG concentrations was observed. Heat-treated colostrum showed dynamic viscosity ranged from 25 to 3066 cP, where dynamic viscosity of colostrum before- and after heat-treatment showed no significant correlation. Treated colostrum containing IgG concentration ≤80 mg mL-1 at 60°C/60 min and ≤68 mg mL-1 at 63.5°C/30 min showed no significant change in the viscosity and can successfully be applied for pasteurization of first postpartum colostrum.

scholarly journals Synthesis of titanium nitride via hybrid nanocomposites based on mesoporous TiO2/acrylonitrile

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Claudiu Locovei ◽  
Anita-Laura Chiriac ◽  
Andreea Miron ◽  
Sorina Iftimie ◽  
Vlad-Andrei Antohe ◽  
...  
Keyword(s):  
Titanium Nitride ◽  
Hybrid Composites ◽  
Nitrogen Atmosphere ◽  
Sem Analysis ◽  
Hybrid Nanocomposites ◽  
Thermal Treatments ◽  
Nitrogen Flow ◽  
Hybrid Nanocomposite ◽  
Xrd Patterns ◽  
Different Content

AbstractIn the present study, the synthesis of titanium nitride (TiN) by carbothermal reduction nitridation (CRN) reaction using nanocomposites made of mesoporous TiO2/acrylonitrile with different content of inorganic phase were explored. The choice of hybrid nanocomposite as precursor for the synthesis of TiN was made due to the possibility of having an intimate interface between the organic and inorganic phases in the mixture that can favours CRN reaction. Subsequently, the hybrid composites have been subjected to four-step thermal treatments at 290 °C, 550 °C, 1000 °C and 1400 °C under nitrogen atmosphere. The XRD results after thermal treatment at 1000 °C under nitrogen flow show the coexistence of two crystalline phases of TiO2, i.e. anatase and rutile, as well as TiN phase, together with the detection of amorphous carbon that proved the initiation of CRN reaction. Furthermore, the observations based on XRD patterns of samples thermally treated at 1400 °C in nitrogen atmosphere were in agreement with SEM analysis, that shows the formation of TiN by CRN reaction via hybrid nanocomposites mesoporous TiO2/acrylonitrile.

scholarly journals Quantitative assessment of German Holstein dairy cattle colostrum and impact of thermal treatment on quality of colostrum viscosity and immunoglobulins

2020 ◽  
Author(s):  
Abdulwahed Ahmed Hassan ◽  
Sebastian Ganz ◽  
Florian Schneider ◽  
Axel Wehrend ◽  
Izhar U.H. Khan ◽  
...  
Keyword(s):  
Refractive Index ◽  
Dairy Cattle ◽  
Dynamic Viscosity ◽  
Correlation Coefficients ◽  
Thermal Treatments ◽  
Heat Treated ◽  
Before And After ◽  
C 30 ◽  
The Impact

Abstract Objective: This study aimed to determine the color, fat, viscosity, IgG concentration, %Brix and refractive index of fresh postpartum colostrum of German Holstein dairy cattle and assess the impact of different thermal treatments on the visual and dynamic viscosity, in association to IgG concentration, of colostrum that can be used for pasteurization process.Results: Of the total 40 fresh postpartum colostrum, the color of colostrum (white-pale yellow to yellow and dark-yellowish), fat (1.4 - 8.2 100 g-1), IgG (4 - 116 mg mL-1), %Brix (8.5 - 35.4%), refractive index (1.3454 - 1.3905 nD), visual (ranging from watery to liquid and thick) and dynamic (4.9 - 219 cp) viscosity, were recorded. Statistical analysis between visual and dynamic viscosity of fresh colostrum showed significant correlation coefficients (rs = 634). Moreover, a significant correlation between viscosity and three IgG concentrations was observed. Heat-treated colostrum showed dynamic viscosity ranged from 25 to 3066 cP, where dynamic viscosity of colostrum before- and after heat-treatment showed no significant correlation. Treated colostrum containing IgG concentration ≤80 mg mL-1 at 60°C/60 min and ≤68 mg mL-1 at 63.5°C/30 min showed no significant change in the viscosity and can successfully be applied for pasteurization of first postpartum colostrum.

scholarly journals ANALISIS KEBOCORAN & KEBAKARAN TANGKI BLENDING BAHAN BAKAR MIGAS

2021 ◽  
Vol 1 (3) ◽  
pp. 39-47
Author(s):  
Sulistiana Agung Riyanto ◽  
Vidya Rina Wulandari ◽  
Bagas Putra Arfyansyah
Keyword(s):  
Base Metal ◽  
Weld Joint ◽  
Corrosion Products ◽  
Uniform Corrosion ◽  
Tank Wall ◽  
Corrosive Environment ◽  
Joint Area ◽  
Long Time ◽  
Type Fuel

Explosions and fires that occurred in the blending/mixing tanks of fuel with naphtha to produce pertalite type fuel were initiated by a leak in the tank wall. Based on the results of observations, inspections and tests that have been carried out, the leak of the tank which is the cause of the explosion and fire is the result of the reaction of the tank wall in the weld joint area with base metal (HAZ) which is susceptible to corrosion with acidic tank fluid contents (pH- 5) so as to form an acidic and corrosive environment in the tank with the formation of H2S as a corrosion initiator, reinforced by the discovery of corrosion products in the form of MnS, FeS2, and FeS compounds, elements (S), and the appearance of fractography in the form of white dots indicating uniform corrosion if it occurs for a long time can erode the tank wall and form a leak hole.

Corrigendum to: Elastic properties of the forisome

2007 ◽  
Vol 34 (11) ◽  
pp. 1053
Author(s):  
Stephen A. Warmann ◽  
William F. Pickard ◽  
Amy Q. Shen
Keyword(s):  
Mechanical Properties ◽  
Radial Direction ◽  
Mechanical Response ◽  
Viscoelastic Model ◽  
Strain Curve ◽  
Longitudinal Direction ◽  
Tensile Tests ◽  
Before And After

Forisomes are elongate Ca2+-responsive contractile protein bodies and act as flow blocking gates within the phloem of legumes. Because an understanding of their mechanical properties in vitro underpins understanding of their physiology in vivo, we undertook, using a microcantilever method, microscopic tensile tests (incremental stress-relaxation measurements) on forisomes from Canavalia gladiata (Jacq.) DC Akanata Mame and Vicia faba L. Witkiem Major. Viscoelastic properties of forisomes in their longitudinal direction were investigated before and after Ca2+-induced contraction, but in the radial direction only before contraction. Forisomes showed mechanical properties typical of a biological material with a unidirectional fibrous structure, i.e. the modulus of elasticity in the direction of their fibers is much greater than in the radial direction. Creep data were collected in all tensile tests and fit with a three parameter viscoelastic model. The pre-contraction longitudinal elastic moduli of the forisomes were not differentiable between the two species (V. faba, 660���360�kPa; C. gladiata, 600���360�kPa). Both species showed a direction-dependent mechanical response: the elastic modulus was dramatically smaller in the radial direction than in the longitudinal direction, suggesting a weak protein cross-linking amongst longitudinal protein fibers. Activation of forisomes decreased forisome stiffness longitudinally, as evidenced by the loss of toe-region in the stress strain curve, suggesting that the forisome may have dispersed or disordered its protein structure in a controlled fashion. Contractile forces generated by single forisomes undergoing activation were also measured for V. faba (510���390�nN) and C. gladiata (570���310�nN).

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