Pressure-Composition-Isotherm Behavior of Partially Remelted Magnesium Alloys

2006 ◽  
Vol 116-117 ◽  
pp. 263-266
Author(s):  
Tae Whan Hong

Partially Remelted Mg alloys focused only to aspect of semi liquid forming until now. In presents study, for the purpose of proposition as economic lightweight hydrogen absorbing materials, the hydrogenation properties of pressure-composition-isotherm (PCI) apparatus. According to the results of experiments, globules (Mg rich solid phase) were regarded the storage system as a hydrogen absorption/desorption and eutectic/liquid droplets (quenched liquid phase) were considered the catalytic system as an improving factor of hydrogenation kinetics. Especially, the hydrogenation properties were depended on properties of globules and liquid fraction.

1998 ◽  
Vol 22 ◽  
pp. 306-308
Author(s):  
M. D. Carro ◽  
E. L. Miller

The estimation of rumen microbial protein synthesis is one of the main points in the nitrogen (N)-rationing systems for ruminants, as microbial protein provides proportionately 0.4 to 0.9 of amino acids entering the small intestine in ruminants receiving conventional diets (Russell et al., 1992). Methods of estimating microbial protein synthesis rely on marker techniques in which a particular microbial constituent is related to the microbial N content. Marker : N values have generally been established in mixed bacteria isolated from the liquid fraction of rumen digesta and it has been assumed that the same relationship holds in the total population leaving the rumen (Merry and McAllan, 1983). However, several studies have demonstrated differences in composition between solid-associated (SAB) and fluid-associated bacteria in vivo (Legay-Carmier and Bauchart, 1989) and in vitro (Molina Alcaide et al, 1996), as well in marker : N values (Pérez et al., 1996). This problem could be more pronounced in the in vitro semi-continuous culture system RUSITEC, in which there are three well defined components (a free liquid phase, a liquid phase associated with the solid phase and a solid phase), each one having associated microbial populations.The objective of this experiment was to investigate the effect of using different bacterial isolates (BI) on the estimation of microbial production of four different diets in RUSITEC (Czerkawski and Breckenridge, 1977), using (15NH4)2 SO4 as microbial marker, and to assess what effects any differences would have on the comparison of microbial protein synthesis between diets.This study was conducted in conjunction with an in vitro experiment described by Carro and Miller (1997). Two 14-day incubation trials were carried out with the rumen simulation technique RUSITEC (Czerkawski and Breckenridge, 1977). The general incubation procedure was the one described by Czerkawski and Breckenridge (1977) and more details about the procedures of this experiment are given elsewhere (Carro and Miller, 1997).


Author(s):  
Sang-Gyun Kang ◽  
Zhuang Zhuang Han ◽  
Nathalie Daude ◽  
Emily McNamara ◽  
Serene Wohlgemuth ◽  
...  

AbstractRecent studies show that a single MAPT gene mutation can promote alternative tau misfolding pathways engendering divergent forms of frontotemporal dementia and that under conditions of molecular crowding, the repertoire of tau forms can include liquid-liquid phase separation (LLPS). We show here that following pathogenic seeding, tau condenses on the nuclear envelope (NE) and disrupts nuclear-cytoplasmic transport (NCT). Interestingly, NE fluorescent tau signals and small fluorescent inclusions behaved as demixed liquid droplets in living cells. Thioflavin S-positive intracellular aggregates were prevalent in tau-derived inclusions with a size bigger than 3 μm2, indicating that a threshold of critical mass in the liquid state condensation may drive liquid-solid phase transitions. Our findings indicate that tau undergoing LLPS is more toxic amongst a spectrum of alternative conformers; LLPS droplets on the NE that disrupt NCT serve to trigger cell death and can act as nurseries for fibrillar structures abundantly detected in end-stage disease.


1996 ◽  
Vol 75 (3) ◽  
pp. 339-351 ◽  
Author(s):  
Helle N Johansen ◽  
K. E.Bach Knudsen ◽  
Brittmarie Sandström ◽  
F. Skjøth

AbstractFour pigs fitted with a gastric cannula were fed on a wheat-flour-based diet (WF) and three oat-based diets, consisting mainly of oat flour (OF), rolled oats (RO) or oat bran (OB), for 1 week each. The stomach contents were collected quantitatively daily at 0·5, 1, 2, 3 or 5 h after feeding. The viscosity (mPa. s) of the liquid fraction of stomach contents 1 h after feeding was 1·7 with diet WF, 15 with diet OF, 30 with diet RO and approximately 400 with diet OB. The viscosity and the concentration of β-glucan in the liquid phase was to some extent determined by the dietary level of β-glucan in the diet. However, there was a trend towards a lower viscosity after longer exposure to the gastric juices. The correlation between logarithmic values for viscosity and concentration of β-glucan in the liquid phase of digesta was r 0·45. On centrifugation of digesta there was a higher proportion present in the sediment phase when the pigs were fed on diets with a higher content of soluble dietary fibre (DF), suggesting that the digesta was more coherent. This possibility was supported by the higher water-holding capacity (WHC) of the sediment. Feeding diets with oats containing a higher soluble DF content led to lower recoveries of digesta, PEG 4000 (liquid-phase marker), and the DF components β-glucan and arabinoxylan in the first hour after feeding. No effect related to the DF content of the diet was seen in the gastric emptying of starch and Cr2O3(solid-phase marker). In conclusion, soluble DF from oatsincreased the viscosity of stomach contents and increased the ability of the dry matter to retain water. Higher levels of soluble DF led to higher recoveries of digesta, the liquid phase and DF itself in the initial stage of gastric emptying, whereas no effect was seen on the gastric emptying of starch.


Author(s):  
C.D. Humphrey ◽  
T.L. Cromeans ◽  
E.H. Cook ◽  
D.W. Bradley

There is a variety of methods available for the rapid detection and identification of viruses by electron microscopy as described in several reviews. The predominant techniques are classified as direct electron microscopy (DEM), immune electron microscopy (IEM), liquid phase immune electron microscopy (LPIEM) and solid phase immune electron microscopy (SPIEM). Each technique has inherent strengths and weaknesses. However, in recent years, the most progress for identifying viruses has been realized by the utilization of SPIEM.


Author(s):  
N. A. Bulychev

In this paper, the plasma discharge in a high-pressure fluid stream in order to produce gaseous hydrogen was studied. Methods and equipment have been developed for the excitation of a plasma discharge in a stream of liquid medium. The fluid flow under excessive pressure is directed to a hydrodynamic emitter located at the reactor inlet where a supersonic two-phase vapor-liquid flow under reduced pressure is formed in the liquid due to the pressure drop and decrease in the flow enthalpy. Electrodes are located in the reactor where an electric field is created using an external power source (the strength of the field exceeds the breakdown threshold of this two-phase medium) leading to theinitiation of a low-temperature glow quasi-stationary plasma discharge.A theoretical estimation of the parameters of this type of discharge has been carried out. It is shown that the lowtemperature plasma initiated under the flow conditions of a liquid-phase medium in the discharge gap between the electrodes can effectively decompose the hydrogen-containing molecules of organic compounds in a liquid with the formation of gaseous products where the content of hydrogen is more than 90%. In the process simulation, theoretical calculations of the voltage and discharge current were also made which are in good agreement with the experimental data. The reaction unit used in the experiments was of a volume of 50 ml and reaction capacity appeared to be about 1.5 liters of hydrogen per minute when using a mixture of oxygen-containing organic compounds as a raw material. During their decomposition in plasma, solid-phase products are also formed in insignificant amounts: carbon nanoparticles and oxide nanoparticles of discharge electrode materials.


Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1014
Author(s):  
Macy L. Sprunger ◽  
Meredith E. Jackrel

Aberrant protein folding underpins many neurodegenerative diseases as well as certain myopathies and cancers. Protein misfolding can be driven by the presence of distinctive prion and prion-like regions within certain proteins. These prion and prion-like regions have also been found to drive liquid-liquid phase separation. Liquid-liquid phase separation is thought to be an important physiological process, but one that is prone to malfunction. Thus, aberrant liquid-to-solid phase transitions may drive protein aggregation and fibrillization, which could give rise to pathological inclusions. Here, we review prions and prion-like proteins, their roles in phase separation and disease, as well as potential therapeutic approaches to counter aberrant phase transitions.


2000 ◽  
Vol 2000 ◽  
pp. 144-144
Author(s):  
A.J. Ayala-Burgos ◽  
F.D.DeB. Hovell ◽  
R.M. Godoy ◽  
Hamana S. Saidén ◽  
R. López ◽  
...  

Cattle in the tropics mostly depend on pastures. During dry periods the forage available is usually mature, constraining both intake and digestion. These constraints need to be understood, for intake and digestibility define productivity. Intake depends on the rumen space made available by fermentation and outflow. Markers such as PEG (liquid phase), and chromium mordanted fibre (solid phase) can be used to measure rumen volume and outflow, but have limitations. The objective of this experiment was to measure intake, digestibility, and rumen kinetics of cattle fed ad libitum forages with very different degradation characteristics, and also to compare rumen volumes measured with markers with those obtained by manual emptying.


2013 ◽  
Vol 45 (3) ◽  
pp. 261-271 ◽  
Author(s):  
B. Randjelovic ◽  
K. Shinagawa ◽  
Z.S. Nikolic

From many experiments with mixtures of small and large grains, it can be concluded that during liquid phase sintering, smaller grains partially dissolve and a solid phase precipitates on the larger grains and grain coarsening occurs. The growth rate can be controlled either by the solid-liquid phase boundary reaction or by diffusion through the liquid phase. The microstructure may change either by larger grains growing during the Ostwald ripening process or by shape accommodation. In this study, two-dimensional mathematical approach for simulation of grain coarsening by grain boundary migration based on a physical and corresponding numerical modeling of liquid phase sintering will be considered. A combined mathematical method of analyzing viscous deformation and solute diffusion in liquid bridge between two grains with different sizes will be proposed. The viscous FE method will be used for calculating meniscus of the liquid bridge, with the interfacial tensions taken into consideration. The FE method for diffusion will be also implemented by using the same mesh as the deformation analysis.


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