scholarly journals Effects Of The Combined Heat And Cryogenic Treatment On The Stability Of Austenite In A High Co-Ni Steel

2015 ◽  
Vol 60 (3) ◽  
pp. 2131-2137 ◽  
Author(s):  
M. Gruber ◽  
S. Ploberger ◽  
G. Ressel ◽  
M. Wiessner ◽  
M. Hausbauer ◽  
...  
Keyword(s):  
Phase Distribution ◽  
Cryogenic Treatment ◽  
Tempering Temperature ◽  
Factors Affecting ◽  
Transmission Electron ◽  
Reverted Austenite ◽  
Before And After ◽  
Different Temperatures ◽  
The Stability ◽  
The Impact

Abstract The stability of austenite is one of the most dominant factors affecting the toughness properties of high Co-Ni steels such as Aermet 100 and AF1410. Thus, the aim of this work was to get a deeper understanding on the impact of combined heat and cryogenic treatment on the stability of retained and reverted austenite. In order to characterize the evolution of the phase fraction of austenite during tempering at different temperatures and times, X-ray diffraction analyses were carried out. The stability of austenite, which was formed during tempering, was analyzed with dilatometric investigations by studying the transformation behavior of the austenite during cooling from tempering temperature down to −100°C. Additionally, transmission electron microscopy investigations were performed to characterize the chemical composition and phase distribution of austenite and martensite before and after tempering.

scholarly journals Effects of equal channel angular pressing and heat treatments on the microstructures and mechanical properties of selective laser melted and cast AlSi10Mg alloys

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Przemysław Snopiński ◽  
Mariusz Król ◽  
Marek Pagáč ◽  
Jana Petrů ◽  
Jiří Hajnyš ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Heat Treatments ◽  
Electron Backscattered Diffraction ◽  
Angular Pressing ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Before And After ◽  
The Impact

AbstractThis study investigated the impact of the equal channel angular pressing (ECAP) combined with heat treatments on the microstructure and mechanical properties of AlSi10Mg alloys fabricated via selective laser melting (SLM) and gravity casting. Special attention was directed towards determining the effect of post-fabrication heat treatments on the microstructural evolution of AlSi10Mg alloy fabricated using two different routes. Three initial alloy conditions were considered prior to ECAP deformation: (1) as-cast in solution treated (T4) condition, (2) SLM in T4 condition, (3) SLM subjected to low-temperature annealing. Light microscopy, transmission electron microscopy, X-ray diffraction line broadening analysis, and electron backscattered diffraction analysis were used to characterize the microstructures before and after ECAP. The results indicated that SLM followed by low-temperature annealing led to superior mechanical properties, relative to the two other conditions. Microscopic analyses revealed that the partial-cellular structure contributed to strong work hardening. This behavior enhanced the material’s strength because of the enhanced accumulation of geometrically necessary dislocations during ECAP deformation.

Factors affecting the amplitude of the τ angle in proteins: a revisitation

2017 ◽  
Vol 73 (7) ◽  
pp. 618-625 ◽  
Author(s):  
Nicole Balasco ◽  
Luciana Esposito ◽  
Luigi Vitagliano
Keyword(s):  
Protein Structures ◽  
Factors Affecting ◽  
X Ray ◽  
Backbone Conformation ◽  
Potential Factors ◽  
The Stability ◽  
Major Factors ◽  
The Impact ◽  
Open Issues

The protein folded state is the result of the fine balance of a variety of different forces. Even minor structural perturbations may have a significant impact on the stability of these macromolecules. Studies carried out in recent decades have led to the convergent view that proteins are endowed with a flexible spine. One of the open issues related to protein local backbone geometry is the identification of the factors that influence the amplitude of the τ (N—Cα—C) angle. Here, statistical analyses performed on an updated ensemble of X-ray protein structures by dissecting the contribution of the major factors that can potentially influence the local backbone geometry of proteins are reported. The data clearly indicate that the local backbone conformation has a prominent impact on the modulation of the τ angle. Therefore, a proper assessment of the impact of the other potential factors can only be appropriately evaluated when small (φ, ψ) regions are considered. Here, it is shown that when the contribution of the backbone conformation is removed by considering small (φ, ψ) areas, an impact of secondary structure, as defined byDSSP, and/or the residue type on τ is still detectable, although to a limited extent. Indeed, distinct τ-value distributions are detected for Pro/Gly and β-branched (Ile/Val) residues. The key role of the local backbone conformation highlighted here supports the use of variable local backbone geometry in protein refinement protocols.

scholarly journals The Role of Non-Rubber Components on Molecular Network of Natural Rubber during Accelerated Storage

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2880
Author(s):  
Huifeng Zhang ◽  
Lu Zhang ◽  
Xu Chen ◽  
Yueqiong Wang ◽  
Fuchun Zhao ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Network Formation ◽  
Crosslinking Density ◽  
Factors Affecting ◽  
Hardening Mechanism ◽  
Accelerated Storage ◽  
Before And After ◽  
The Impact ◽  
Vital Factor

Though the non-rubber components have long been recognized to be a vital factor affecting the network of natural rubber (NR), the authentic role of non-rubber components on the network during accelerated storage has not been fully illuminated. This work attempts to clarify the impact of non-rubber components on the network for NR during accelerated storage. A natural network model for NR was proposed based on the gel content, crosslinking density, and the non-rubber components distribution for NR before and after centrifugation. Furthermore, the effect of non-rubber components on the network was investigated during accelerated storage. The results show that terminal crosslinking induced by non-rubber components and entanglements are primary factors affecting the network formation during accelerated storage. By applying the tube model to analyze the stress-strain curves of NR, we found that the contribution of the entanglements to the network formation is larger than that of terminal crosslinking during accelerated storage. The work highlights the role of non-rubber components on the network during accelerated storage, which is essential for understanding the storage hardening mechanism of NR.

Experimental Research on Deep Cryogenic Treatment Process of YT30 Cemented Carbide Inserts

2010 ◽  
Vol 139-141 ◽  
pp. 702-705 ◽  
Author(s):  
Hong Juan Yan ◽  
Hong Hai Xu ◽  
Xin Min Li
Keyword(s):  
Orthogonal Experiment ◽  
Cryogenic Treatment ◽  
Cemented Carbide ◽  
Deep Cryogenic Treatment ◽  
Tempering Temperature ◽  
Before And After ◽  
Orthogonal Experiment Method ◽  
Enhance Wear Resistance ◽  
Carbide Inserts ◽  
Cemented Carbide Inserts

Deep Cryogenic treatment (DCT) is a one time permanent process, carried out in such a way that the material is slowly cooled down to the cryogenic temperature, after which it is held at that temperature for a specified period of time and is heated back to room temperature at slow rate followed by low temperature tempering. In this study, the orthogonal experiment method was used to study the DCT process of YT30 cemented carbide inserts. The primary relation of the different factors of DCT was analyzed. TH300 sclerometer was used to measure the hardness of inserts. The microscopes were used to observe the wearing profiles of inserts and microstructures before and after DCT. The orthogonal experiment results show that the effect of soaking temperature on the properties of inserts is the first factor, the soaking time is second one, the cooling rate is third one, and the last one is the tempering temperature. DCT improves the multi-type martensite transformation of Co. Therefore DCT increases hardness and enhance wear resistance of the cemented carbide inserts.

scholarly journals Anthocyanins: Factors Affecting Their Stability and Degradation

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1967
Author(s):  
Bianca Enaru ◽  
Georgiana Drețcanu ◽  
Teodora Daria Pop ◽  
Andreea Stǎnilǎ ◽  
Zorița Diaconeasa
Keyword(s):  
Antimicrobial Properties ◽  
Point Of View ◽  
Water Soluble ◽  
Factors Affecting ◽  
Color Palette ◽  
Number Of Factors ◽  
Major Disadvantage ◽  
Phenolic Group ◽  
The Stability ◽  
The Impact

Anthocyanins are secondary metabolites and water-soluble pigments belonging to the phenolic group, with important functions in nature such as seed dispersal, pollination and development of plant organs. In addition to these important roles in plant life, anthocyanins are also used as natural pigments in various industries, due to the color palette they can produce from red to blue and purple. In addition, recent research has reported that anthocyanins have important antioxidant, anticancer, anti-inflammatory and antimicrobial properties, which can be used in the chemoprevention of various diseases such as diabetes, obesity and even cancer. However, anthocyanins have a major disadvantage, namely their low stability. Thus, their stability is influenced by a number of factors such as pH, light, temperature, co-pigmentation, sulfites, ascorbic acid, oxygen and enzymes. As such, this review aims at summarizing the effects of these factors on the stability of anthocyanins and their degradation. From this point of view, it is very important to be precisely aware of the impact that each parameter has on the stability of anthocyanins, in order to minimize their negative action and subsequently potentiate their beneficial health effects.

scholarly journals The Impact of Coating Ingredients on the Aging Resistance of Topcoat Paints by Model Trees

2020 ◽  
Author(s):  
Tzu-Tsung Wong ◽  
Shih-Hsuan Hung
Keyword(s):  
Linear Regression ◽  
Regression Models ◽  
Prediction Method ◽  
Linear Regression Models ◽  
Key Factors ◽  
Model Trees ◽  
Factors Affecting ◽  
Aging Resistance ◽  
Before And After ◽  
The Impact

Topcoat paint is mainly composed of resin and pigment and hence its quality highly depends on the type and proportion of these two ingredients. This study aims at testing the formula of the topcoat paint for finding one that can achieve better quality for anti-aging. Various formulas of paint are applied on boards that will be put into ultraviolet accelerated test machines to simulate weathering tests. The gloss and color, before and after the tests, are collected and numerical prediction method M5P is used to grow model trees for discovering the key factors affecting aging. Based on the structure and the linear regression models in the trees, a better topcoat paint should be composed of a high proportion of resin and generally a low proportion of pigment. Good types of resin and pigment are also identified for keeping color and gloss.

Investigation of TiW Contacts to 4H-SiC Bipolar Junction Devices

2006 ◽  
Vol 527-529 ◽  
pp. 887-890
Author(s):  
Hyung Seok Lee ◽  
Martin Domeij ◽  
Carl Mikael Zetterling ◽  
Mikael Östling ◽  
Jun Lu
Keyword(s):  
Ohmic Contacts ◽  
Carbide Formation ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Transmission Line Method ◽  
Before And After ◽  
Different Temperatures ◽  
Important Challenge ◽  
Junction Transistor ◽  
P Type

One important challenge in SiC Bipolar Junction Transistor (BJT) fabrication is to form good ohmic contacts to both n-type and p-type SiC. In this paper, we have examined contact study in a SiC BJT process with sputter deposition of titanium tungsten contacts to both n-type and p-type regions followed by annealing at different temperatures between 750 oC and 950 oC. The contacts were characterized using linear transmission line method (LTLM) structures. To see the formation of compound phases, X-ray Diffraction (XRD) θ-2θ scans were performed before and after annealing. The results indicate that 5 minutes annealing at 950 oC of the n+ contact is sufficient whereas the p+ contacts remain non-ohmic after 30 minutes annealing. The n+ emitter structure contact resistivity after 5 min annealing with 750 oC and 950 oC was 1.08 × 10-3 5cm2 and 4.08 × 10-4 5cm2, respectively. Small amorphous regions of silicon and carbon as well as titanium tungsten carbide regions were observed by high-resolution transmission electron microscopy (HRTEM), whereas less carbide formation and no amorphous regions were found in a sample with unsuccessful formation of TiW ohmic contacts.

scholarly journals Stability issues in presence variable distributed generation into radial distribution network

2018 ◽  
Vol 218 ◽  
pp. 01005 ◽  
Author(s):  
Rahman Yuli Asmi ◽  
Agus Siswanto ◽  
Irwan Mahmudi
Keyword(s):  
Distributed Generation ◽  
Voltage Stability ◽  
Reactive Power ◽  
Load Condition ◽  
Stability Index ◽  
Before And After ◽  
Voltage Deviation ◽  
Bus Voltage ◽  
The Stability ◽  
The Impact

Related to environmental issues resulting from the use of traditional energy sources, drive usage of renewable energy is increasing. Changes in the structure of the network will certainly affect the changes in voltage stability. In this paper, discuss the impact of the stability after distributed generation penetration whose its output intermittent relatively. The simulation based PSAT software and tested into IEEE 30 bus system. Observation of voltage deviation and SVSI-index on some load buses in conditions before and after integration of wind generation. Load condition is a very determining factor of bus voltage stability index. This relates to the active power and reactive power needs that must be injected by DG penetration.

scholarly journals Optimization of GOPS-Based Functionalization Process and Impact of Aptamer Grafting on the Si Nanonet FET Electrical Properties as First Steps towards Thrombin Electrical Detection

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1842
Author(s):  
Monica Vallejo-Perez ◽  
Céline Ternon ◽  
Nicolas Spinelli ◽  
Fanny Morisot ◽  
Christoforos Theodorou ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Field Effect Transistors ◽  
Time Dependent ◽  
Epifluorescence Microscopy ◽  
Electrical Detection ◽  
Si Nanowires ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Before And After ◽  
The Impact

Field effect transistors (FETs) based on networks of randomly oriented Si nanowires (Si nanonets or Si NNs) were biomodified using Thrombin Binding Aptamer (TBA–15) probe with the final objective to sense thrombin by electrical detection. In this work, the impact of the biomodification on the electrical properties of the Si NN–FETs was studied. First, the results that were obtained for the optimization of the (3-Glycidyloxypropyl)trimethoxysilane (GOPS)-based biofunctionalization process by using UV radiation are reported. The biofunctionalized devices were analyzed by atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM), proving that TBA–15 probes were properly grafted on the surface of the devices, and by means of epifluorescence microscopy it was possible to demonstrate that the UV-assisted GOPS-based functionalization notably improves the homogeneity of the surface DNA distribution. Later, the electrical characteristics of 80 devices were analyzed before and after the biofunctionalization process, indicating that the results are highly dependent on the experimental protocol. We found that the TBA–15 hybridization capacity with its complementary strand is time dependent and that the transfer characteristics of the Si NN–FETs obtained after the TBA–15 probe grafting are also time dependent. These results help to elucidate and define the experimental precautions that must be taken into account to fabricate reproducible devices.

scholarly journals Pace and stability of embryonic development affect telomere dynamics: an experimental study in a precocial bird model

2020 ◽  
Vol 287 (1933) ◽  
pp. 20201378 ◽  
Author(s):  
Antoine Stier ◽  
Neil B. Metcalfe ◽  
Pat Monaghan
Keyword(s):  
Embryonic Development ◽  
Telomere Length ◽  
Incubation Temperature ◽  
Key Factors ◽  
Factors Affecting ◽  
Adult Disease ◽  
Potential Contributor ◽  
The Stability ◽  
The Impact ◽  
Telomere Dynamics

Prenatal effects on telomere length are increasingly recognized as a potential contributor to the developmental origin of health and adult disease. While it is becoming clear that telomere length is influenced by prenatal conditions, the factors affecting telomere dynamics during embryogenesis remain poorly understood. We manipulated both the pace and stability of embryonic development through varying incubation temperature and its stability in Japanese quail. We investigated the impact on telomere dynamics from embryogenesis to adulthood, together with three potential drivers of telomere shortening, growth rate, oxidative damage and prenatal glucocorticoid levels. Telomere length was not affected by our prenatal manipulation for the first 75% of embryogenesis, but was reduced at hatching in groups experiencing faster (i.e. high temperature) or less stable embryonic development. These early life differences in telomere length persisted until adulthood. The effect of developmental instability on telomere length at hatching was potentially mediated by an increased secretion of glucocorticoid hormones during development. Both the pace and the stability of embryo development appear to be key factors determining telomere length and dynamics into adulthood, with fast and less stable development leading to shorter telomeres, with the potential for adverse associated outcomes in terms of reduced longevity.

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