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.

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

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

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

Study of B-→D**0π-(D**0→D(*)+π-) decays

journal articl

Security Mechanism for user access to Single SSID WLAN

Wireless local area network (WLAN) technology is widely used in various enterprises and institutions. In order to facilitate the use of users, they often provide a single ssid access point, resulting in different identities of users authenticated and authorized can connect to the wireless network anytime, anywhere as needed and obtain the same accessible network resources such as bandwidth, access control (ACL) and so on. Multiple ssid can solve the problem but it will be confused to users who don't know which ssid can be connected. Although we could prevent visitors from accessing intranet resources by isolating the wireless network from the internal network, this would make it impossible for users to use the wireless network for internal office work. In this paper, we propose an access control sysytem that grouping users according to the different identities and users authenticated and authorized can access different network resources because a wireless access point dynamically maps an ssid provided by a mobile station to a BSSID based on a VLAN assignment. The deployment experiment of the solution proves that users of different identities accessing the same wireless network can set different access policies, which effectively improves the security of the wireless network and simplifies the management of the wireless network

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 Cr­(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^–1 to 10^–3 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

Efficient Cross-Coupling of Aryl Chlorides with Arylzinc Reagents Catalyzed by Amido Pincer Complexes of Nickel

The nickel-catalyzed Negishi cross-coupling reaction of aryl chlorides with arylzinc compounds was investigated. The nickel complexes with the amido pincer type of ligands exhibited high catalytic activity and good functional group tolerance

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⁺PI^– 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