scholarly journals Transient Evolution of Inclusions during Al and Ti Additions in Fe-20 Mass pct Cr Alloy

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 702
Author(s):  
Xuefeng Bai ◽  
Yanhui Sun ◽  
Yimin Zhang
Keyword(s):  
Cross Sections ◽  
Ostwald Ripening ◽  
Particle Agglomeration ◽  
Electrolytic Extraction ◽  
Factors Affecting ◽  
Titanium Wire ◽  
Al Addition ◽  
Major Factors ◽  
Ti Addition ◽  
Local Supersaturation

The transient evolution of inclusions during Al and Ti additions in a Fe-20 mass pct Cr alloy was investigated using polished cross sections and electrolytic extraction. After Al addition, the evolution of Al2O3-based inclusions based upon the area and particle size passed through the following three main stages with time: Particle agglomeration, inclusion floating, and a slow decrease of the remaining Al2O3-based inclusions. Titanium wire was fed into the steel at the end of the floating stage after Al addition when the Ostwald ripening process was finished. Immediately after Ti addition, the transient phase of Ti oxide was readily generated on the existing Al2O3-based inclusion and disappeared due to Al reduction as time progressed. The formation of the transient TiOx phase was affected by the low disregistry between Al2O3 and TiOx and the local Ti supersaturation, which cannot be predicted by the equilibrium relations of Ti–O–N or Ti–Al–O in the high-Cr-containing melt. Because of the local supersaturation of dissolved [%Ti] and [%N] shortly after Ti addition, TiN associated with existing inclusions and three types of individual TiN including single cubes, twinned inclusions, and clusters were identified. In order to minimize the Ti loss caused by the formation of Ti-rich zones during the transient stages, the removal of large Al2O3-based particles including aggregates, clusters, and flower-shaped inclusions should be promoted by stirring before Ti addition. After Ti addition, Brownian and turbulent were the major factors affecting the collision of particles smaller than the threshold of 2.7 μm. The agglomeration of inclusions larger than this threshold was mainly dominated by turbulent and Stokes’ collisions.

scholarly journals Relationship between Land Use Mix and Walking Choice in High-Density Cities: A Review of Walking in Seoul, South Korea

2021 ◽  
Vol 13 (2) ◽  
pp. 810
Author(s):  
Eun Yeong Seong ◽  
Nam Hwi Lee ◽  
Chang Gyu Choi
Keyword(s):  
Land Use ◽  
Neighborhood Environment ◽  
Single Family ◽  
Housing Type ◽  
General Belief ◽  
Factors Affecting ◽  
Land Use Mix ◽  
Family Housing ◽  
Mixed Land Use ◽  
Major Factors

This study confirmed the general belief of urban planners that mixed land use promotes walking in Seoul, a metropolis in East Asia, by analyzing the effect of mixed land use on the travel mode choice of housewives and unemployed people who make non-commuting trips on weekdays. Using binomial logistic regression of commuting data, it was found that the more mixed a neighborhood environment’s uses are, the more the pedestrians prefer to walk rather than drive. The nonlinear relationship between the land use mix index and the choice to walk was also confirmed. Although mixed land use in neighborhoods increased the probability of residents choosing walking over using cars, when the degree of complexity increased above a certain level, the opposite effect was observed. As the density of commercial areas increased, the probability of selecting walking increased. In addition to locational characteristics, income and housing type were also major factors affecting the choice to walk; i.e., when the residents’ neighborhood environment was controlled for higher income and living in an apartment rather than multi-family or single-family housing, they were more likely to choose driving over walking.

scholarly journals Is it possible to estimate the need for surgical management in patients with a tubo-ovarian abscess at admission? A retrospective long-term analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Murat Gözüküçük ◽  
Esra Gülen Yıldız
Keyword(s):  
Surgical Treatment ◽  
Antibiotic Therapy ◽  
Treatment Failure ◽  
Medical Treatment ◽  
Length Of Hospital Stay ◽  
Treatment Modalities ◽  
Laboratory Findings ◽  
Factors Affecting ◽  
Laboratory Infection ◽  
Major Factors

Abstract Background This study aimed to determine the possible prognostic factors correlated with the treatment modalities of tubo-ovarian abscesses (TOAs) and thus to assess whether the need for surgery was predictable at the time of initial admission. Materials and methods Between January 2012 and December 2019, patients who were hospitalized with a TOA in our clinic were retrospectively recruited. The age of the patients, clinical and sonographic presentation, pelvic inflammatory risk factors, antibiotic therapy, applied surgical treatment, laboratory infection parameters, and length of hospital stay were recorded. Results The records of 115 patients hospitalized with a prediagnosis of TOA were reviewed for the current study. After hospitalization, TOA was ruled out in 19 patients, and data regarding 96 patients was included for analysis. Twenty-eight (29.2%) patients underwent surgical treatment due to failed antibiotic therapy. Sixty-eight (70.8%) were successfully treated with parenteral antibiotics. Medical treatment failure and need for surgery were more common in patients with a large abscess (volume, > 40 cm3, or diameter, > 5 cm). The group treated by surgical intervention was statistically older than the patients receiving medical treatment (p < 0.05). Conclusions Although the treatment in TOA may vary according to clinical, sonographic, and laboratory findings; age of patients, the abscess size, and volume were seen as the major factors affecting medical treatment failure. Moreover, TOA treatment should be planned on a more individual basis.

scholarly journals Progress in Research on Carbon Nanotubes Reinforced Cementitious Composites

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Qinghua Li ◽  
Jintao Liu ◽  
Shilang Xu
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
High Strength ◽  
Cementitious Composites ◽  
Scale Production ◽  
Multiwalled Carbon ◽  
Factors Affecting ◽  
Environment And Health ◽  
Research Activities ◽  
Major Factors

As one-dimensional (1D) nanofiber, carbon nanotubes (CNTs) have been widely used to improve the performance of nanocomposites due to their high strength, small dimensions, and remarkable physical properties. Progress in the field of CNTs presents a potential opportunity to enhance cementitious composites at the nanoscale. In this review, current research activities and key advances on multiwalled carbon nanotubes (MWCNTs) reinforced cementitious composites are summarized, including the effect of MWCNTs on modulus of elasticity, porosity, fracture, and mechanical and microstructure properties of cement-based composites. The issues about the improvement mechanisms, MWCNTs dispersion methods, and the major factors affecting the mechanical properties of composites are discussed. In addition, large-scale production methods of MWCNTs and the effects of CNTs on environment and health are also summarized.

Evaluation of Si Coating on Ferritic Steels by CVD-FBR Technology in Steam Oxidation

2009 ◽  
Vol 289-292 ◽  
pp. 413-420 ◽  
Author(s):  
F.J. Bolívar ◽  
L. Sánchez ◽  
M.P. Hierro ◽  
F.J. Pérez
Keyword(s):  
Power Plants ◽  
Protective Coatings ◽  
Steam Oxidation ◽  
Steam Turbines ◽  
X Ray Diffraction ◽  
Steam Power ◽  
Factors Affecting ◽  
Steam Power Plants ◽  
Temperature And Pressure ◽  
Major Factors

The development of new power generation plants firing fossil fuel is aiming at achieving higher thermal efficiencies of the energy conversion process. The major factors affecting the efficiency of the conventional steam power plants are the temperature and, to a lesser extent, the pressure of the steam entering the turbine. The increased operating temperature and pressure require new materials that have major oxidation resistance. Due to this problem, in the last years numerous studies have been conducted in order to develop new coatings to enhance the resistance of steels with chromium contents between 9 and 12% wt against steam oxidation in order to allow operation of steam turbines at 650 0C. In this study, Si protective coatings were deposited by CVD-FBR on ferritic steel P-91. These type of coatings have shown to be protective at 650 0C under steam for at least 3000 hours of laboratory steam exposure under atmospheric pressure. Morphology and composition of coatings were characterized by different techniques, such as scanning electron microscopy (SEM), electron probe microanalysis, and X-ray diffraction (XRD). The results show a substantial increase of steam oxidation protection afforded by Si coating by CVD-FBR process.

The prediction of voluntary intake of grazing dairy cows

1986 ◽  
Vol 107 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Lindsey Caird ◽  
W. Holmes
Keyword(s):  
Organic Matter ◽  
Measurement Techniques ◽  
Live Weight ◽  
Simple Equation ◽  
Factors Affecting ◽  
Farm Planning ◽  
Sward Height ◽  
The Mean ◽  
Major Factors ◽  
Grazing Dairy Cows

SUMMARYInformation on the total organic matter intake, concentrates supplied (C), live weight (LW), week of lactation (WL), milk yield (MY), herbage organic matter digestibility (HOMD), herbage mass, sward height (SHT) or herbage allowance (HAL) measured individually for 357 cows at one of three sites was assembled. Observed intake was compared with intakes predicted by existing intake equations and new prediction equations based on regression models or regression and least-squares constants were developed. Major factors affecting intake were MY, LW, WL, C and HAL or SHT. Although HOMD was correlated with intake, better predictions were obtained when HOMD was omitted. There were differences between sites possibly associated with differences in measurement techniques.The predictive value of some existing equations and new equations were tested against independent sets of data. A simple equation (A) based on MY and LW (Ministry of Agriculture, Fisheries and Food, 1975) gave satisfactory average predictions but the mean square prediction error (MSPE) was high. The equations of Vadiveloo & Holmes (1979) adjusted for bias gave a relatively low MSPE. The preferred new equations for grazing cattle included MY, LW, WL, C and HAL or SHT, and their MSPE were similar to or lower than for indoor equations.The discussion indicates that a simple equation (A) would give adequate predictions for farm planning. The more detailed equations illustrate the inter-relations of animal with sward conditions and concentrate allowances. Predicted intakes may deviate from actual intakes because of short-term changes in body reserves.

scholarly journals Improved In Situ Hybridization Efficiency with Locked-Nucleic-Acid-Incorporated DNA Probes

2006 ◽  
Vol 72 (8) ◽  
pp. 5311-5317 ◽  
Author(s):  
Kengo Kubota ◽  
Akiyoshi Ohashi ◽  
Hiroyuki Imachi ◽  
Hideki Harada
Keyword(s):  
In Situ Hybridization ◽  
Nucleic Acid ◽  
Fluorescence Intensity ◽  
Dna Probes ◽  
Locked Nucleic Acid ◽  
Factors Affecting ◽  
Hybridization Efficiency ◽  
Probe Hybridization ◽  
Major Factors

ABSTRACT Low signal intensity due to poor probe hybridization efficiency is one of the major drawbacks of rRNA-targeted in situ hybridization. There are two major factors affecting the hybridization efficiency: probe accessibility and affinity to the targeted rRNA molecules. In this study, we demonstrate remarkable improvement in in situ hybridization efficiency by applying locked-nucleic-acid (LNA)-incorporated oligodeoxynucleotide probes (LNA/DNA probes) without compromising specificity. Fluorescently labeled LNA/DNA probes with two to four LNA substitutions exhibited strong fluorescence intensities equal to or greater than that of probe Eub338, although these probes did not show bright signals when they were synthesized as DNA probes; for example, the fluorescence intensity of probe Eco468 increased by 22-fold after three LNA bases were substituted for DNA bases. Dissociation profiles of the probes revealed that the dissociation temperature was directly related to the number of LNA substitutions and the fluorescence intensity. These results suggest that the introduction of LNA residues in DNA probes will be a useful approach for effectively enhancing probe hybridization efficiency.

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.

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