1,477 research outputs found
Effects of niobium on phase transformations from austenite to ferrite in low carbon steels
Niobium is a widely used microalloying element in many steel products, e.g. plates,
strip, sections and linepipe. Niobium has important effects on transformation
behaviour, grain size refinement and precipitation strengthening during hot rolling
and subsequent cooling, with even a low content of niobium having a strong effect
on the transformation rate from austenite to ferrite. The purpose of this research was
to accurately characterise and quantify the effects of solute niobium atoms and
niobium carbo-nitride precipitates on phase transformations from austenite and
ferrite, and to incorporate these effects into metallurgical models to predict the
transformation behaviour and microstructure of niobium containing steels, which can
benefit industry through their use of the models to optimise processing conditions. [Continues.
Modelling of Nb influence on phase transformation behaviours from austenite to ferrite in low carbon steels
In this paper, a new model has been developed to predict the phase transformation
behaviours from austenite to ferrite in Nb-containing low carbon steels. The
new model is based on some previous work and incorporates the effects of
Nb on phase transformation behaviours, in order to make it applicable for
Nb-containing steels. Dissolved Nb atoms segregated at prior austenite grain
boundaries increase the critical energy for ferrite nucleation, and thus the
ferrite nucleation rate is decreased. Dissolved Nb atoms also apply a solute
drag effect to the moving transformation interface, and the ferrite grain growth
rate is also decreased. The overall transformation kinetics is then calculated
according to the classic Johnson–Mehl–Avrami–Kolmogorov (JMAK) theory.
The new model predictions are quite consistent with experimental results for
various steels during isothermal transformations or continuous cooling
Analysis Efficiency Marketing System of Fresh Layang Fish (Decapterus Russeli) on Pelabuhan Fish Auction Place in Tegal City
Marketing is an important aspect in running fishing business because it is an economic activity that influences the fluctuation of fishermen\u27s income. The production can be useless if the price is low, thus, marketing has to be good and efficient. This research is about the efficiency of the marketing system of fresh fish layang (Decapterus russeli) in the fish auction place. Specifically, this research is to know : 1) the marketing system of fresh fish layang in Tegal City. 2) the marketing margin of fresh fish layang in Tegal City. 3) the distribution flow of fresh fish layang in Tegal City. 4) the reason fishermen sell their products in the Fish Auction Place. The method use in this research is descriptive analysis method, The registration data and literature study. Based on the analysis, it is known that the marketing system of fresh in the Fish Auction Place, seen from the marketing cost calculation, purchasing price, selling price and profit is < 1, which means efficient. And if seen from the marketing margin, the most efficient flow is channel 4 (the 4th channel). Meanwhile, the reason why fishermen sell their Fish Auction Place is because of the guarantee that their product will be sold. Fish is a product that is easily broken and rotten. Therefore, the guarantee that the product will be sold, can minimize loss risk for fisherman
Verstärkung und Vernetzung von SBR mit silanisierter gefällter Kieselsäure
Amorpher Kieselsäure-Nanofüllstoff wurde für die Verstärkung und Vernetzung von
Styrol-Butadien-Kautschuk verwendet. Die Oberflächen der Kieselsäure war vorher
mit Bis[3-triethoxysilylpropyl-)tetrasulfid (TESPT), einem difunktionellen Organosilan
vorbehandelt. TESPT vermittelt die Haftung von Kieselsäure zum Kautschuk,
außerdem verhindert es, dass die Kieselsäure mit der Reaktion der Schwefelvulkanisation interferiert. Die Kieselsäureteilchen wurden vollkommen im Kautschuk dispergiert, der in erster Linie durch Schwefel aus dem TESPT, oder auch durch die Zugabe
von elementarem Schwefel zu dem Vernetzungssystem vernetzt wurde. Die Vernetzung wurde auch durch die Zugabe von verschiedenen Beschleunigern und Aktivatoren in die Kautschukmischung optimiert. Diese Untersuchung zeigte, dass die
Kieselsäure sowohl zur Vernetzung, als auch zur Verstärkung des Kautschuks verwendet werden können.
Synthetic precipitated amorphous white silica nanofiller was used to reinforce and
crosslink styrene-butadiene rubber (SBR). The silica surfaces were pre-treated with
bis[3-triethoxysilylpropyl-)tetrasulfide (TESPT) bifunctional organosilane. TESPT
chemically adheres silica to rubber and also prevents silica from interfering with the
reaction mechanism of Schwefel-cure. The silica particles were fully dispersed in the
rubber, which was cured primarily by using Schwefel in TESPT, or, by adding elemental
Schwefel to the cure system. The cure was also optimized by incorporating different
accelerators and activators in the rubber. This study showed that the silica particles
could be used both as crosslinking and reinforcing filler in the rubber
I. Selim Bey’in ikinci kısım Amerika hatıraları
I. Selim Bey'in Haftalık Mecmua'da tefrika edilen I. Selim Bey’in İkinci Kısım Amerika Hatıraları adlı roman
Illite Spatial Distribution Patterns Dictate Cr(VI) Sorption Macrocapacity and Macrokinetics
This work examines the largely unexplored
role of illite spatial
distribution patterns in dictating the sorption of CrÂ(VI), a ubiquitously
occurring contaminant. Flow-through experiments were carried out at
0.6, 3.0, and 15.0 m/day using columns packed with the same illite
and quartz mass however with different spatial patterns and permeability
contrasts. Column-scale sorption macrocapacity and macrorates were
found to decrease with transport connectivity, a quantitative measure
of heterogeneity characteristics. At 0.6 and 3.0 m/day, well-connected
low permeability illite zones oriented in the flow-parallel direction
lead to diffusion-controlled mass transport limitation for accessing
sorption sites. This results in up to 1.4 order of magnitude lower
macrocapacity and macrorates compared to those in minimally connected
columns with well-mixed illite and quartz. At 15.0 m/day, effects
of spatial heterogeneities are less significant (up to a factor of
2.8) owing to the close to chemical kinetics-controlled condition.
Although the column-scale macrocapacity can reach full sorption capacity
under low flow conditions, the macrorates are 10<sup>–1</sup> to 10<sup>–3</sup> of the microrates measured in well-mixed
reactors. Insights gained here bridge gaps between laboratory observations
and field applications and advance predictive understanding of reactive
transport processes in the naturally heterogeneous subsurface
S-wave permeability of Navajo sandstone and Berea sandstone
Ultrasonic S-wave is used to determine S-wave permeability of Navajo sandstone and Berea sandstone.</p
miR-24 inhibits CHOP-induced Bim overexpression in ER mediated apoptosis pathway.
<p>(A) Validation of knockdown efficiency using siRNA against <i>ATF6, CHOP, JNK</i> and <i>XBP1</i> by qPCR. (B) miR-24 expression level was not altered upon knockdown of Caspase 3, Caspase 8, Caspase 9, Caspase 12, ATF6, CHOP, JNK or XBP1. (C) Knockdown of CHOP but not other factors in the ER stress pathway partially rescued increased apoptosis caused by miR-24 inhibition. *, p<0.05. Data were analyzed by unpaired Student's t test. (D) PCR for <i>Bim</i> showing decreased <i>Bim</i> expression upon CHOP knockdown. *, p<0.05. Data were analyzed by unpaired Student's t test. (E) Western for Bim showing decreased Bim protein level when CHOP siRNA was transfected into primary CMs. GAPDH serves as a loading control.</p
miR-24 inhibits the intrinsic apoptosis pathway.
<p>(A) FACS analysis on AnnexinV<sup>+</sup>PI<sup>–</sup> - apoptotic cells treated with Camp with (middle panel) or without miR-24 mimic (right panel). The control group is shown in the left panel. Camp., Camptothecin (B) Quantification on AnnexinV<sup>+</sup>PI<sup>–</sup> cells treated with Fas or Camp with or without miR-24 mimic. (C) Inhibition of Caspase 9, Caspase 12 or Caspase 3, but not caspase 8, rescued the miR-24 loss-of-function phenotype. Cells were incubated with Z-IETD-FMK, Z-LEHD-FMK, Z-ATAD-FMK or Z-VAD-FMK for assessment of caspase-8, -9, -12 and pan caspases activity, respectively. (D) Knockdown of <i>Caspase 9, Caspase 12</i> or <i>Caspase 3</i>, but not <i>Caspase 8</i>, rescued the increased apoptosis caused by inhibition of miR-24. *, p<0.05; **, p<0.01. Data were analyzed by unpaired Student's t test. (E) Validation of knockdown efficiency using siRNA cocktail against <i>Caspase 3, 8, 9</i> and <i>12</i> by qPCR. RQ, Relative Quantification. Error bars represent SEM.</p
miR-24 modulates ER-mediated apoptosis pathway.
<p>(A) miR-24 attenuates thapsigargin and tunicamycin induced cell death through ER-mediated apoptosis pathway. Mouse cardiomyocytes with or without overexpression of miR-24 were cultured with thapsigargin or tunicamycin for six hours. Cells were stained with FITC-conjugated Annexin V and PI for flow cytometry. Tha, thapsigargin; Tun, tunicamycin. (B) Percentage of AnnexinV<sup>+</sup>PI<sup>–</sup> cells in Fig. 2A shown as mean ± SEM. These data are representative of three independent experiments. *, p<0.05. Data were analyzed by unpaired Student's t test. (C) Western blot for Caspase 12 and Bim from primary CMs transfected with miR-24 mimic, inhibitor, or corresponding controls. GAPDH serves as a loading control.</p
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