Granular bainite or granular ferrite? A preliminary TEM investigation of an HSLA-100 steel

1991 ◽  
Vol 49 ◽  
pp. 584-585
Author(s):  
R. Varughese ◽  
S. W. Thompson ◽  
P. R. Howell
Keyword(s):  
Room Temperature ◽  
Transformation Products ◽  
Accurate Description ◽  
Granular Bainite ◽  
Preliminary Results ◽  
The Past ◽  
Light Micrograph ◽  
Multiphase Reaction ◽  
Detailed Nature

Ever since Habraken and Economopoulos first employed the term granular bainite to classify certain unconventional transformation products in continuously cooled steels, the term has been widely accepted and used, despite the lack of a clear consensus as to the detailed nature of the transformation products which constitute granular bainite. This paper presents the preliminary results of a TEM investigation of an 0.04 wt% C, copper-containing steel (designated HSLA-100). It is suggested that the term granular ferrite rather than granular bainite is a more accurate description of this multiphase reaction product.Figure 1 is a light micrograph of a sample which had been air-cooled from 900°C to room temperature. The microstructure is typical of that which has been termed granular bainite in the past and appears to consist of equiaxed ferritic grains together with other minor transformation products. In order to examine these structures in more detail, both continuously cooled and isothermally transformed and quenched materials have been examined with TEM. Granular bainite has been found in virtually all samples.

Organophotoredox-Catalyzed C–H Alkylation of Imidazoheterocycles with Malonates: Total Synthesis of Zolpidem

Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity
Keyword(s):  
Total Synthesis ◽  
Room Temperature ◽  
Drug Molecule ◽  
Bond Functionalization ◽  
First Report ◽  
Mild Conditions ◽  
The Past ◽  
Hypnotic Drug ◽  
Free Environment

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.

Increase in Cell Number as a Factor in the Growth of the Organs and Tissues of the Young Male Rat

Development ◽  
1962 ◽  
Vol 10 (4) ◽  
pp. 530-562
Author(s):  
M. Enesco ◽  
C. P. Leblond
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Room Temperature ◽  
Young Male ◽  
Cell Number ◽  
The Body ◽  
Male Rat ◽  
The Past ◽  
Old Rats ◽  
Young Rat

While the organs and tissues of the young rat are known to increase in size with age (Donaldson, 1924), little is known of the role played by the component cells in this increase. There is evidence that cells enlarge (Levi, 1906; Plenk, 1911) and new cells are added (Strasburger, 1893), but we do not know to what extent the enlargement and proliferation of the cells cause the growth of organs and tissues. The present work is an attempt to clarify this problem. In the past, the growth of organs and tissues has often been measured by weight gain (Donaldson, 1924). However, this approach might be misleading, since the body-weight may increase in the absence of growth, for instance as a result of fat-storage in old rats, of pregnancy in females, and even of changes in room temperature.

Feasibility Study of a New Fabrication Method for the Li4SiO4 Pebbles

2018 ◽  
Author(s):  
R. Lo Frano ◽  
M. Puccini ◽  
E. Stefanelli ◽  
M. Luppichini ◽  
C. Grima ◽  
...  
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Power Reactor ◽  
Fabrication Method ◽  
Fusion Power ◽  
Spray Process ◽  
The Past ◽  
Experimental Apparatus ◽  
Standard Solution ◽  
Lithium Orthosilicate

In the past decades many R&D efforts have been spent in the development of a suitable Li4SiO4 fabrication method (e.g., melt spray process, graphite bed method, capillary-based microfluidic wet method etc.), nevertheless we are still far from an “industrial standard solution”. The aim of the paper is to develop a new fabrication method capable to produce stable and well-sized pebbles of lithium orthosilicate (Li4SiO4) based on the drip casting. This method is mainly based on the dripping at room temperature, which is novel in the framework of available fabrication processes requiring high temperature: this latter is demonstrated to affect the final product characteristics. It is worthy to remark that the Li4SiO4 is a candidate material for the breeding blanket material of the fusion power reactor. In the paper we will describe the experimental apparatus, designed and built at DICI - University of Pisa with the collaboration of Bitossi Industries, and the procedure adopted in order to produce pebbles of Li4SiO4.

scholarly journals Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
W. H. Haniffah ◽  
S. M. Sapuan ◽  
K. Abdan ◽  
M. Khalid ◽  
M. Hasan ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tensile Properties ◽  
Room Temperature ◽  
Tap Water ◽  
Tensile Modulus ◽  
Polypropylene Composites ◽  
Preliminary Results ◽  
Kenaf Fibre ◽  
The Difference ◽  
Number Of Cycles

This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity). The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

Cartilage Scales Embedded in Fibrin Gel

2017 ◽  
Vol 33 (02) ◽  
pp. 225-232 ◽  
Author(s):  
Milos Kovacevic ◽  
Frank Riedel ◽  
Jochen Wurm ◽  
Gregor Bran
Keyword(s):  
Regenerative Medicine ◽  
Surgical Techniques ◽  
Fibrin Gel ◽  
Platelet Rich Fibrin ◽  
Preliminary Results ◽  
Advantages And Disadvantages ◽  
The Past ◽  
Dorsal Nasal Augmentation ◽  
Diced Cartilage ◽  
Nasal Augmentation

Multiple techniques have been described for dorsal nasal augmentation in rhinoplasty. In this article, we review common surgical techniques for raising the dorsum or eliminating dorsal irregularities, by highlighting inherent advantages and disadvantages of each method. Within the past few years, the use of diced cartilage grafts has become the workhorse in this field of interest. To overcome drawbacks of methods based on diced cartilage, we present a new concept for autologous augmentation, using regenerative medicine protocols. A mix of cartilage scales with cartilage pâté was embedded in platelet-rich fibrin (PRF). Since December 2015, a total of 48 patients were treated with this technique. Based on our preliminary results, cartilage scales in PRF appear to be a promising and reliable alternative to existing procedures for dorsal nasal augmentation.

scholarly journals Chiral Separation of rac-Propylene Oxide on Penicillamine Coated Gold NPs

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1716
Author(s):  
Nisha Shukla ◽  
Zachary Blonder ◽  
Andrew J. Gellman
Keyword(s):  
Propylene Oxide ◽  
Room Temperature ◽  
Adsorption Properties ◽  
Time Dependent ◽  
Prior Work ◽  
Au Nps ◽  
The Past ◽  
Racemic Mixtures ◽  
Enantioselective Adsorption ◽  
Gold Nps

The surfaces of chemically synthesized spherical gold NPs (Au-NPs) have been modified using chiral L- or D-penicillamine (Pen) in order to impart enantioselective adsorption properties. These chiral Au-NPs have been used to demonstrate enantioselective adsorption of racemic propylene oxide (PO) from aqueous solution. In the past we have studied enantioselective adsorption of racemic PO on L- or D-cysteine (Cys)-coated Au-NPs. This prior work suggested that adsorption of PO on Cys-coated Au-NPs equilibrates within an hour. In this work, we have studied the effect of time on the enantioselective adsorption of racemic PO from solution onto chiral Pen/Au-NPs. Enantioselective adsorption of PO on chiral Pen/Au-NPs is time-dependent but reaches a steady state after ~18 h at room temperature. More importantly, L- or D-Pen/Au-NPs are shown to adsorb R- or S-PO enantiospecifically and to separate the two PO enantiomers from racemic mixtures of RS-PO.

scholarly journals Analyses of the LMC Novae

1999 ◽  
Vol 190 ◽  
pp. 391-392
Author(s):  
Karen M. Vanlandingham ◽  
Greg J. Schwarz ◽  
Sumner Starrfield ◽  
Peter H. Hauschildt ◽  
Steven N. Shore ◽  
...  
Keyword(s):  
Stellar Evolution ◽  
Large Magellanic Cloud ◽  
Optical Spectra ◽  
Classical Novae ◽  
Preliminary Results ◽  
Elemental Abundances ◽  
Ultraviolet Spectra ◽  
The Past ◽  
Consistent Manner ◽  
Ism Abundances

In the past 10 years, 6 classical novae have been observed in the Large Magellanic Cloud (LMC). We have begun a study of these objects using ultraviolet spectra obtained by IUE and optical spectra from nova surveys. We are using the results of this study to further our understanding of novae and stellar evolution.Our study includes analysis of both the early, optically thick spectra using model atmospheres (Hauschildt et al. 1992), and the later nebular spectra using optimization of photoionization codes (Ferland 1996; James & Roos 1993). By analysing all the LMC novae in a consistent manner, we can compare their individual results and use their combined properties to calibrate Galactic novae. In addition, our studies can be used to determine the elemental abundances of the nova ejecta, the amount of mass ejected, and the contribution of novae to the ISM abundances. To date we have analysed Nova LMC 1988#1 (Schwarz et al. 1998) and Nova LMC 1990#1 (Vanlandingham et al. 1999), and have obtained preliminary results for Nova LMC 1991. The results of this work are presented in this poster.

scholarly journals Approach of Serial Crystallography

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 854
Author(s):  
Ki Hyun Nam
Keyword(s):  
Radiation Damage ◽  
Room Temperature ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Past ◽  
Wide Range ◽  
Experimental Limitation ◽  
Serial Crystallography ◽  
Collection Strategies

Radiation damage and cryogenic sample environment are an experimental limitation observed in the traditional X-ray crystallography technique. However, the serial crystallography (SX) technique not only helps to determine structures at room temperature with minimal radiation damage, but it is also a useful tool for profound understanding of macromolecules. Moreover, it is a new tool for time-resolved studies. Over the past 10 years, various sample delivery techniques and data collection strategies have been developed in the SX field. It also has a wide range of applications in instruments ranging from the X-ray free electron laser (XFEL) facility to synchrotrons. The importance of the various approaches in terms of the experimental techniques and a brief review of the research carried out in the field of SX has been highlighted in this editorial.

scholarly journals Twinning in MAPbI3 at room temperature uncovered through Laue neutron diffraction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joachim Breternitz ◽  
Michael Tovar ◽  
Susan Schorr
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Neutron Diffraction ◽  
Room Temperature ◽  
Point Of View ◽  
Temperature Structure ◽  
Theoretical Point ◽  
Laue Diffraction ◽  
The Past ◽  
Halide Perovskites

Abstract The crystal structure of MAPbI3, the signature compound of the hybrid halide perovskites, at room temperature has been a reason for debate and confusion in the past. Part of this confusion may be due to twinning as the material bears a phase transition just above room temperature, which follows a direct group–subgroup relationship and is prone to twinning. Using neutron Laue diffraction, we illustrate the nature of twinning in the room temperature structure of MAPbI3 and explain its origins from a group-theoretical point-of-view.

Effect of Potassium Carbonate Additive on CO2 Absorption in Lithium Zirconate Powder

1998 ◽  
Vol 547 ◽  
Author(s):  
T. Ohashi ◽  
K. Nakagawa
Keyword(s):  
Potassium Carbonate ◽  
Room Temperature ◽  
Absorption Rate ◽  
Co2 Absorption ◽  
The Past ◽  
Lithium Zirconate ◽  
Kinetics Of

AbstractLithium zirconate, which reacts with CO2 reversibly at temperatures over 500°C, is expected to find wider application than conventional CO2 absorbents, as the latter can be used only at room temperature. We examined the effect of potassium carbonate, which had usually been added to facilitate the formation of lithium zirconate in the past, on the kinetics of CO2 absorption reaction. The result shows that the CO2 absorption rate of lithium zirconate powder is extremely accelerated by the potassium carbonate additive. We conclude that this acceleration results from the formation of a eutectic carbonate composed of Li2CO3 and K2CO3.

Sign in / Sign up

Export Citation Format

Share Document