77,425 research outputs found
Two-phase coexistence in Fe–Ni alloys synthesized by ball milling
We used mechanical alloying with a Spex 8000 mixer/mill to synthesize a series of Fe100–xNix alloys from x=0 to x=49. The Spex mill was modified so that it could also operate at a reduced milling intensity, and we compared the alloys synthesized after long times with the normal and reduced milling intensities. X-ray diffractometry and Mössbauer spectrometry were used to measure the volume fractions of the bcc and fcc phases in the alloys, and to determine the chemical compositions of the individual phases. We found that the composition ranges of the bcc and fcc single phase regions were extended well beyond their equilibrium ranges. At the higher milling intensity, we found that the bcc phase was destabilized with respect to the fcc phase, and the two-phase region shifted to lower Ni concentrations. For those alloys with coexisting bcc and fcc phases, we present evidence that the chemical compositions of the two phases are nearly the same. We explain the destabilization of the bcc with milling intensity as originating with a higher defect density in the bcc alloys than in the fcc alloys. We argue that this defect density is not homogeneous throughout the alloy, however, and the distribution of defect enthalpies can explain the two-phase coexistence in the as-milled alloys
Entanglement entropy on a fuzzy sphere with a UV cutoff
We introduce a UV cutoff into free scalar field theory on the noncommutative
(fuzzy) two-sphere. Due to the IR-UV connection, varying the UV cutoff allows
us to control the effective nonlocality scale of the theory. In the resulting
fuzzy geometry, we establish which degrees of freedom lie within a specific
geometric subregion and compute the associated vacuum entanglement entropy.
Entanglement entropy for regions smaller than the effective nonlocality scale
is extensive, while entanglement entropy for regions larger than the effective
nonlocality scale follows the area law. This reproduces features previously
obtained in the strong coupling regime through holography. We also show that
mutual information is unaffected by the UV cutoff.Comment: Significantly revised with improved methodology, 16 pages, 8 figure
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Quantification of Dehydroepiandrosterone, 17β-Estradiol, Testosterone, and Their Sulfates in Mouse Tissues by LC-MS/MS.
We report a high-performance, liquid chromatography/tandem mass spectrometry (HPLC-MS/MS) assay to quantify without derivatizaton dehyroepiandrosterone (DHEA), 17β-estradiol (E2), testosterone (T), and their sulfates in serum and tissues. This assay functions well with multiple adipose depots, a previously unattained analysis. To delipidate and facilitate recovery, tissues were homogenized in acetonitrile, and the homogenate was frozen. The supernatant was evaporated, resuspended in an aqueous acetate buffer, and extracted with hexane to separate free (unconjugated) from sulfated steroids. Sulfated steroids in the aqueous medium were then hydrolyzed with sulfatase and extracted with hexane. Each extract was analyzed separately. HPLC resolution combined with the sensitivity and specificity of MS/MS allowed quantification of DHEA, E2, and T with 10, 10, and 5 fmol lower limits of quantification and linear ranges to 1 pmol. Application of the method to mouse serum and tissues reveals ranges of DHEA, E2, and T and their sulfates, and tissue-specific differences in steroid profile, especially white versus brown adipose. In addition, marginal decreases of T in all tissues and considerable increases in DHEA in male iWAT and eWAT in response to a high-fat diet further strengthen the inference regarding the role of steroid metabolism in adipogenesis. This assay permits detailed studies of interactions between adiposity and sex steroids in serum and tissues, including adipose
A Lexicalized Tree-Adjoining Grammar for Vietnamese
In this paper, we present the first sizable grammar built for Vietnamese using LTAG, developed over the past two years, named vnLTAG. This grammar aims at modelling written language and is general enough to be both application- and domain-independent. It can be used for the morpho-syntactic tagging and syntactic parsing of Vietnamese texts, as well as text generation. We then present a robust parsing scheme using vnLTAG and a parser for the grammar. We finish with an evaluation using a test suite
Changes of Physico–Chemical Properties of Pig Slurry During Storage
This study was aimed to determine changes of the characteristics of raw pig slurry as liquid organic fertilizer at various storage times. A completely randomized design was used in this research. The treatments were storage times, i.e.: 0, 15, 30, 45, and 60 days. Variables observed were loss of the slurry, degree of acidity (pH), electrical conductivity (EC), total solid (TS), volatile solid (VS), total chemical oxygen demand (tCOD), soluble chemical oxygen demand (sCOD), total nitrogen (TN), ammonia-nitrogen (NH3-N), nitrate-nitrogen (NO3-N), total phosphate (TP), and dissolve reactive phosphate (DRP). The results showed that storage time significantly affected all the observed variables, except the concentration of NO3-N and total phosphate content. The pH, TS, VS, DRP, and losses of slurry lost during storage times increased, while EC, TN, NH3-N, tCOD, and sCOD decreased. Physico-chemical properties of slurry during storage times changed, as a result of organic matter breakdown
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