710 research outputs found
Thermodynamics of Chaplygin gas
We clarify thermodynamics of the Chaplygin gas by introducing the
integrability condition. All thermal quantities are derived as functions of
either volume or temperature. Importantly, we find a new general equation of
state, describing the Chaplygin gas completely. We confirm that the Chaplygin
gas could show a unified picture of dark matter and energy which cools down
through the universe expansion without any critical point (phase transition).Comment: 5 pages, 4 figures, version "Accepted for publication in Astrophysics
& Space Science
Entropic force and its cosmological implications
We investigate a possibility of realizing the entropic force into the
cosmology. A main issue is how the holographic screen is implemented in the
Newtonian cosmology. Contrary to the relativistic realization of Friedmann
equations, we do not clarify the connection between Newtonian cosmology and
entropic force because there is no way of implementing the holographic screen
in the Newtonian cosmology.Comment: 16 pages, no figures, version "Accepted for publication in
Astrophysics & Space Science
Effects of various additives to enhance growth performance, blood profiles, and reduce malodour emissions in growing pigs
Experiment 1 was a feeding trial in which 75 (Landrace ⅹ Yorkshire) ⅹ Duroc pigs with average initial bodyweight (BW) of 26 ± 1 kg were used. It was assigned to three pigs/pen and five pens/treatment. Experiment 2 was a metabolic trial in which 25 (LandraceⅹYorkshire)ⅹDuroc pigs with average initial bodyweight (BW) of 36 ± 1 kg were used. The basal diet consisted of maize (57.71 %), soybean meal (32.45 %), and wheat bran (5 %). Treatments consisted of i) CON (control diet); ii) OE (organic acid + essential oils) (Aviplus-S®), that is, CON + 0.05 % OE; iii) OC (organic charcoal) (Olga Black®), that is, CON + 0.1 % OC; iv) AE (anise extracts) (RESQ®), that is, CON + 0.015 % AE; and v) PB (probiotics) (Bonvital®), that is, CON + 0.1 % PB. Average daily gain (ADG) and gain/feed ratio (G : F) were significantly higher in the OE and AE groups than in the others. Average daily feed intake (ADFI) for OE, OC, and AE treatments was significantly higher than that for CON and PB treatments. Dry matter (DM) digestibility was significantly higher in AE than CON. Crude protein (CP) was significantly higher in OE, AE, and PB than CON. CON and other treatments did not cause significant differences in blood l-density lipoprotein (LDL), and glucose. NH3 emissions were significantly lower in all treated groups than in CON. Among the treatments, NH3 emissions were lowest in OE and AE. H2S emissions were significantly lower in OE, AE, and PB than in CON. Among the treatments, OE and AE were most effective at reducing H2S emissions. The emissions of volatile fatty acids (VFAs) showed no significant difference between treatments and CON. In conclusion, this experiment was shown to be more effective on growth performance, malodour emission, blood profiles, and nutrient digestibility in OE and AE than other additives.Keywords: Digestibility, feed, influence, odour, supplementation, swin
Onset of rigidty in glasses: from random to self-organized networks
We review in this paper the signatures of a new elastic phase that is found
in glasses with selected compositions. It is shown that in contrast with random
networks, where rigidity percolates at a single threshold, networks that are
able to self-organize to avoid stress will remain in an almost stress- free
state during a compositional interval, an intermediate phase, that is bounded
by a flexible phase and a stressed rigid phase. We report the experimental
signatures and describe the theoretical efforts that have been accomplished to
characterize the intermediate phase. We illustrate one of the methods used in
more detail with the example of Group III chalcogenides and finally suggest
further possible experimental signatures of self-organization.Comment: 27 pages, 6 figures, Proceedings of the Conference on Non-Crystalline
Materials 10, to appear in Journal of Non-Crystalline Solid
Rings and rigidity transitions in network glasses
Three elastic phases of covalent networks, (I) floppy, (II) isostatically
rigid and (III) stressed-rigid have now been identified in glasses at specific
degrees of cross-linking (or chemical composition) both in theory and
experiments. Here we use size-increasing cluster combinatorics and constraint
counting algorithms to study analytically possible consequences of
self-organization. In the presence of small rings that can be locally I, II or
III, we obtain two transitions instead of the previously reported single
percolative transition at the mean coordination number , one from a
floppy to an isostatic rigid phase, and a second one from an isostatic to a
stressed rigid phase. The width of the intermediate phase and the
order of the phase transitions depend on the nature of medium range order
(relative ring fractions). We compare the results to the Group IV
chalcogenides, such as Ge-Se and Si-Se, for which evidence of an intermediate
phase has been obtained, and for which estimates of ring fractions can be made
from structures of high T crystalline phases.Comment: 29 pages, revtex, 7 eps figure
A New Upper Limit for the Tau-Neutrino Magnetic Moment
Using a prompt neutrino beam in which a nu_tau component was identified for
the first time, the nu_tau magnetic moment was measured based on a search for
an anomalous increase in the number of neutrino-electron interactions. One such
event was observed when 2.3 were expected from background processes, giving an
upper 90% confidence limit of 3.9x10^-7 Bohr magnetons.Comment: 9 pages; 1 figur
An analysis of the FIR/RADIO Continuum Correlation in the Small Magellanic Cloud
The local correlation between far-infrared (FIR) emission and radio-continuum
(RC) emission for the Small Magellanic Cloud (SMC) is investigated over scales
from 3 kpc to 0.01 kpc. Here, we report good FIR/RC correlation down to ~15 pc.
The reciprocal slope of the FIR/RC emission correlation (RC/FIR) in the SMC is
shown to be greatest in the most active star forming regions with a power law
slope of ~1.14 indicating that the RC emission increases faster than the FIR
emission. The slope of the other regions and the SMC are much flatter and in
the range of 0.63-0.85. The slopes tend to follow the thermal fractions of the
regions which range from 0.5 to 0.95. The thermal fraction of the RC emission
alone can provide the expected FIR/RC correlation. The results are consistent
with a common source for ultraviolet (UV) photons heating dust and Cosmic Ray
electrons (CRe-s) diffusing away from the star forming regions. Since the CRe-s
appear to escape the SMC so readily, the results here may not provide support
for coupling between the local gas density and the magnetic field intensity.Comment: 19 pages, 7 Figure
Detection and classification of turn fault and high-resistance connection fault in inverter-fed permanent magnet machines based on high-frequency signals
Winding turn fault and high-resistance connection (HRC) fault will lead to different consequences and require different mitigation actions. In this study, the differentiating features between a turn fault and HRC fault are analysed and compared in a three-phase surface-mounted permanent magnet machine fed by the inverter with pulse-width-modulation voltages. The resultant high-frequency components in both voltages and currents are utilised for the fault detection and classification based on the high-frequency impedance and ripple current, without requiring modifications to the machine or interface design. Extensive simulations show that this method is capable of fault detection and classification in both transient and steady-state operations
Prospects for Constraining Cosmology with the Extragalactic Cosmic Microwave Background Temperature
Observers have demonstrated that it is now feasible to measure the cosmic
microwave background (CMB) temperature at high redshifts. We explore the
possible constraints on cosmology which might ultimately be derived from such
measurements. Besides providing a consistency check on standard and alternative
cosmologies, possibilities include: constraints on the inhomogeneity and
anisotropy of the universe at intermediate redshift ; an
independent probe of peculiar motions with respect to the Hubble flow; and
constraining the epoch of reionization. We argue that the best possibility is
as a probe of peculiar motions. We show, however, that the current measurement
uncertainty (K) in the local present absolute CMB
temperature imposes intrinsic limits on the use of such CMB temperature
measurements as a cosmological probe. At best, anisotropies at intermediate
redshift could only be constrained at a level of and peculiar
motions could only be determined to an uncertainty of km
s. If the high CMB temperature can only be measured with a precision
comparable to the uncertainty of the local interstellar CMB temperature, then
peculiar motions could be determined to an uncertainty of .Comment: 8 pages 2 Figures, PRD Submitte
Screening for Prediabetes and Type 2 Diabetes: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force
Importance: Type 2 diabetes is common and is a leading cause of morbidity and disability. Objective: To review the evidence on screening for prediabetes and diabetes to inform the US Preventive Services Task Force (USPSTF). Data Sources: PubMed/MEDLINE, Cochrane Library, and trial registries through September 2019; references; and experts; literature surveillance through May 21, 2021. Study Selection: English-language controlled studies evaluating screening or interventions for prediabetes or diabetes that was screen detected or recently diagnosed. Data Extraction and Synthesis: Dual review of abstracts, full-text articles, and study quality; qualitative synthesis of findings; meta-analyses conducted when at least 3 similar studies were available. Main Outcomes and Measures: Mortality, cardiovascular morbidity, diabetes-related morbidity, development of diabetes, quality of life, and harms. Results: The review included 89 publications (N = 68882). Two randomized clinical trials (RCTs) (25120 participants) found no significant difference between screening and control groups for all-cause or cause-specific mortality at 10 years. For harms (eg, anxiety or worry), the trials reported no significant differences between screening and control groups. For recently diagnosed (not screen-detected) diabetes, 5 RCTs (5138 participants) were included. In the UK Prospective Diabetes Study, health outcomes were improved with intensive glucose control with sulfonylureas or insulin. For example, for all-cause mortality the relative risk (RR) was 0.87 (95% CI, 0.79 to 0.96) over 20 years (10-year posttrial assessment). For overweight persons, intensive glucose control with metformin improved health outcomes at the 10-year follow-up (eg, all-cause mortality: RR, 0.64 [95% CI, 0.45 to 0.91]), and benefits were maintained longer term. Lifestyle interventions (most involving >360 minutes) for obese or overweight persons with prediabetes were associated with reductions in the incidence of diabetes (23 RCTs; pooled RR, 0.78 [95% CI, 0.69 to 0.88]). Lifestyle interventions were also associated with improved intermediate outcomes, such as reduced weight, body mass index, systolic blood pressure, and diastolic blood pressure (pooled weighted mean difference, -1.7 mm Hg [95% CI, -2.6 to -0.8] and -1.2 mm Hg [95% CI, -2.0 to -0.4], respectively). Metformin was associated with a significant reduction in diabetes incidence (pooled RR, 0.73 [95% CI, 0.64 to 0.83]) and reduction in weight and body mass index. Conclusions and Relevance: Trials of screening for diabetes found no significant mortality benefit but had insufficient data to assess other health outcomes; evidence on harms of screening was limited. For persons with recently diagnosed (not screen-detected) diabetes, interventions improved health outcomes; for obese or overweight persons with prediabetes, interventions were associated with reduced incidence of diabetes and improvement in other intermediate outcomes
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