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Author(s):  
O. M. Dyakonov ◽  
V. Yu. Sereda

The process of inorganic and organic components temperature transformation of metal waste into solid and gaseous products in a continuous hot briquetting muffle furnace has been studied. The composition of the hydrocarbon atmosphere formed in the muffle under conditions of limited access to the oxidizer has been determined. It is shown that the thermal destruction of the coolant oil phase proceeds according to a complex mechanism of consecutive reactions, including polycondensation, polymerization, and deep compaction with a constant decrease in the hydrogen content and ends with the formation of a coke‑like carbon residue on the surface of metal particles and an air suspension of finely dispersed carbon particles (smoke). When it is heated to hot briquetting temperatures of 750–850 °C, chemically active dispersions of ferrous metals are protected from oxidation first by a hydrocarbon gas with a density of 9.0–13.5 kg/m3, then by a pyrocarbon coating with a thickness of 0.1–0.3 mm up to the completion of the processes of pressing and cooling the briquette.


Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1345
Author(s):  
Sun-Woo Nam ◽  
Sang-Min Park ◽  
Mohammad Zarar Rasheed ◽  
Myung-Suk Song ◽  
Do-Hyang Kim ◽  
...  

During the liquid metal extraction reaction between a Nd-Dy-Fe-B magnet and liquid Mg, Nd rapidly diffuses out of the magnet, whereas Dy is not extracted due to the reaction with the matrix and the formation of Dy2Fe17 phase. In addition, theDy2O3 phase exists at the grain boundaries. Until now, only the effect of the Dy2O3 phase on the extraction of Dy has been reported. In this study, the effect of the Dy2Fe17 phase on the extraction of Dy from the Nd-Dy-Fe-B magnet was investigated in liquid Mg. The formation of the Dy2Fe17 phase during the reaction between Mg and matrix (RE2Fe14B) was first examined using a thermodynamical approach and confirmed by microstructural analysis. It was observed that Dy extraction was dominated by Dy2Fe17 phase decomposition from 3 h to 24 h, followed by Dy2O3 phase dominant reaction with Mg. Comparing the activities of the Dy2Fe17 phase and the Dy2O3 phase, the reaction of Dy2Fe17 is dominant, as compared to the Dy2O3 phase. Finally, at 48 h, the high Dy extraction percentage of 93% was achieved. As a result, in was concluded that the Dy2Fe17 phase acts as an obstacle in the extraction of Dy. In the future, if research to control the Dy2Fe17 phase proceeds, it will be of great importance to advance the recycling of Dy.


2018 ◽  
Author(s):  
Lu Liu ◽  
Yue Zhang ◽  
Jingjing Zhang ◽  
Jian-Hua Wang ◽  
Qinhong Cao ◽  
...  

AbstractThe core of the eukaryotic helicase MCM is loaded as an inactive double hexamer (DH). How it is assembled into two active Cdc45-MCM-GINS (CMG) helicases remains elusive. Here, we report that at the onset of S phase, both Cdc45 and GINS are loaded as dimers onto MCM DH, resulting in formation of double CMG (d-CMG). As S phase proceeds, d-CMGs gradually mature into two single CMG-centered replisome progression complexes (RPCs). Mass spectra reveal that RPA and DNA Pol α/primase co-purify exclusively with RPCs, but not with d-CMGs. Consistently, d-CMGs are not able to catalyze either the unwinding or de novo DNA synthesis, while RPCs can do both. Using single-particle electron microscopy, we have obtained 2D class averages of d-CMGs. Compared to MCM DHs, they display heterogeneous, flexibly orientated and partially loosened conformations with changed interfaces. The dumbbell-shaped d-CMGs are mediated by Ctf4, while other types of d-CMGs are independent of Ctf4. These data suggest CMG dimers as bona fide intermediates during MCM maturation, providing an additional quality control for symmetric origin activation and bidirectional replication.


2016 ◽  
Vol 18 (34) ◽  
pp. 23910-23915 ◽  
Author(s):  
Jozef Lengyel ◽  
Christian van der Linde ◽  
Michal Fárník ◽  
Martin K. Beyer

The reaction of dichlorodifluoromethane (CF2Cl2) with hydrated electrons (H2O)n− (n = 30–86) in the gas phase proceeds via dissociative electron transfer, resulting in the formation of a chloride ion.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 9548-9548 ◽  
Author(s):  
Di Sun ◽  
Allison Kaeding ◽  
Daniel Magoon ◽  
Tamekia Jones ◽  
Meenakshi Devidas ◽  
...  

9548 Background: MLL-r infant ALL overexpresses activated FLT3. Lestaurtinib potentiates chemotherapy(chemo)-induced cytotoxicity in MLL-r ALL. AALL0631 therapy is stratified based on age and MLL status: high risk (HR) <90 days, MLL-r; intermediate risk (IR) ≥ 90 days, MLL-r; standard risk any age, not MLL-r. IR and HR patients (pts) get intensive chemo and are eligible for lestaurtinib. A safety/activity (S/A) phase to determine a safe and biologically active dose of lestaurtinib is followed by an efficacy phase randomizing MLL-r patients to chemo +/- lestaurtinib. The S/A phase proceeds independently for IR & HR pts, as optimal lestaurtinib dosing may differ between neonates and older infants. We previously reported successful completion of the S/A phase for IR pts; here, we report results of the S/A phase for HR pts. Methods: Lestaurtinib-related dose limiting toxicities (DLTs) were defined as grade ≥ 3 non-heme toxicities excluding those expected with chemo alone (e.g., F&N/infection); a dose of lestaurtinib was “safe” if 0 or 1 DLTs were seen in 5 evaluable pts. FLT3 inhibition was assessed using a plasma inhibitory activity (PIA) assay that measures % inhibition of phospho-FLT3 at 5 trough time points relative to pre-treatment baseline. A dose of lestaurtinib was “biologically active” if PIA was > 90% for the majority (≥3 of 5) of troughs in at least 3 of 5 pts. Results: 11 eligible HR pts received lestaurtinib, 6 at dose level 1 (DL1, 3.5 mg/kg/day) and 5 at DL2 (4.25 mg/kg/day). There were no DLTs in 5 evaluable pts at DL1. The inevaluable pt discontinued lestaurtinib due to parental refusal, not toxicity. There was 1 DLT in 5 evaluable pts at DL2. The DLT was grade 4 intestinal perforation secondary to severe typhlitis during neutropenia following reinduction, possibly related to lestaurtinib. The pt was taken off protocol and chemo and died of progressive disease. By PIA assay, 2 of 5 pts treated at DL1, and 4 of 5 at DL2 demonstrated FLT3 inhibitory biologic activity. Conclusions: DL2 is safe and biologically active in HR pts. The efficacy phase of AALL0631 is expanding such that HR pts will join IR pts in being randomized (1:1) post-induction to chemo +/- lestaurtinib at DL2.


2011 ◽  
Vol 64 (10) ◽  
pp. 2029-2037 ◽  
Author(s):  
Elena Ficara ◽  
Francesca Malpei

A laboratory experimental campaign was carried out in order to assess the optimal configuration for the anaerobic digestion of a mixture of sweet corn and ensiled maize. Batch hydrolysis tests were conducted at 35 and 55 °C and at four different particle sizes (2, 5, 20 and 50 mm) obtained by manual chopping and sieving. Chemical pre-treatment by 24 h incubation at various acid and alkaline pH was also considered for its potential to increase the maize methane yield. Results suggest that the hydrolytic phase proceeds significantly faster under thermophilic conditions. Significant differences in the solubilization rate were also observed when comparing coarse (20–50 mm) with fine (2–5 mm) particles, while 2 and 5 mm particles were solubilized at similar rates. No advantages from the chemical pre-treatment, in terms of solubilization efficiency and biomethanization potential were observed. According to these preliminary results, a two-stage semi-continuous laboratory plant consisting of a thermophilic hydrolytic reactor followed by a mesophilic methanogenic reactor was operated for 110 days. Steady state loading parameters were: influent concentration (maize mixture diluted in tap water) of 46 g VS/L, hydraulic retention time of 31 d, organic loading rate of 1.5 g VS/L/d. Alkalinity was dosed to the methanogenic reactor to avoid pH drops. Collected data allowed the average biodegradation efficiency to be estimated at around 60–65%.


Author(s):  
G. Chiatti ◽  
O. Chiavola ◽  
G. Falcucci

During the last years, emission standards for diesel engines have got more and more severe not only for light- and heavy-duty road application, but also in the nonroad, locomotive and stationary fields. In this paper, the results of a Lumped Parameter (LP) model for Diesel Particulate Filter (DPF) management in stationary diesel engines are presented. The developed LP model allows to predict the pressure drop and soot layer growth in time along the trap channel. In the model, the equations are tuned by means of a complete CFD analysis of the gas flux through a wall-flow DPF. The difference in flow field due to the radial distance from the filter axis and its effects on the soot growth inside the channel are taken into account as the loading phase proceeds. The temperature evolution during the regeneration process of the device is predicted, too, thus permitting a complete management of the filter in control applications.


2002 ◽  
Vol 67 (2) ◽  
pp. 111-113 ◽  
Author(s):  
Alexei Pankratov ◽  
Inna Uchaeva

By means of the PM3 method it has been shown that the protonation of 2-, 3 4-methoxyanilines, 4-methylthioaniline, 2-, 3-, 4-aminobenzoic acids, 2 3-, 4-nitroanilines in the gaseous phase proceeds via the amine nitrogen atom. The same result, attributed to the aqueous medium, was obtained for 4-methoxyaniline, 4-aminobenzoic acid and 4-nitroaniline.


1998 ◽  
Vol 553 ◽  
Author(s):  
Nicholas A. Spurr ◽  
Patrick J. Pinhero ◽  
Daniel J. Sordelet ◽  
Kurt R. Hebert ◽  
Patricia A. Thiel

AbstractWe report the electrochemical potentials at which localized pitting and repassivation occur on icosahedral Al-Cu-Fe, and on a series of related alloys and elemental metals. The electrochemistry occurs in a buffered NaCI solution, pH 8.4. Under these conditions, pitting and repassivation appear to be controlled mainly by the chemical composition of the alloy, although the quasicrystalline phase displays an anomalous resistance to repassivation. Corrosion of this phase proceeds by dissolution of Al and Fe, leaving behind pits which are Cu-enriched.


1996 ◽  
Vol 452 ◽  
Author(s):  
A. V. Kadavanich ◽  
A. Mews ◽  
S. H. Tolbert ◽  
X. Peng ◽  
M. C. Schlamp ◽  
...  

AbstractWe use High Resolution Transmission Microscopy (HRTEM) to study CdSe, CdS/HgS/CdS quantum-dot quantum well (QDQW), and CdSe/CdS core-shell nanocrystals, grown by wet-chemical techniques. The nanocrystals have faceted Wulff polyhedron shapes.In addition to HRTEM, we employ multi-wavelength anomalous dispersion (MAD) x-ray diffraction. We use computer modeling to help interpret the experimental data.Growth of a heterogeneous phase proceeds epitaxially preserving the overall shape and point-group symmetry of the original seed nanocrystals, both for wurtzite (CdSe/CdS) and zincblende (CdS/HgS/CdS) type structures.Recently prepared InAs nanocrystals also show evidence of faceting as observed by HRTEM and may lend themselves equally well to epitaxy.


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