Effective Action for Cosmological Scalar Fields at Finite Temperature

Scalar fields appear in many theories beyond the Standard Model of particle physics. In the early universe, they are exposed to extreme conditions, including high temperature and rapid cosmic expansion. Understanding their behavior in this environment is crucial to understand the implications for cosmology. We calculate the finite temperature effective action for the field expectation value in two particularly important cases, for damped oscillations near the ground state and for scalar fields with a flat potential. We find that the behavior in both cases can in good approximation be described by a complex valued effective potential that yields Markovian equations of motion. Near the potential minimum, we recover the solution to the well-known Langevin equation. For large field values we find a very different behavior, and our result for the damping coefficient differs from the expressions frequently used in the literature. We illustrate our results in a simple scalar model, for which we give analytic approximations for the effective potential and damping coefficient. We also provide various expressions for loop integrals at finite temperature that are useful for future calculations in other models.Comment: 34 pages plus appendix, 17 figures: minor corrections, modifications of discussions, added references, version published in JHE

Human microglial cells synthesize albumin in brain

Albumin has been implicated in Alzheimer's disease since it can bind to and transport amyloid beta, the causative agent; albumin is also a potent inhibitor of amyloid beta polymerization. In a pilot phase study of Human Brain Proteome Project, we found evidence that albumin may be synthesized in immortalized human microglial cells, human primary microglial cells, and human fetal and adult brain tissues. We also found the synthesis and secretion is enhanced upon microglial activation by Amyloid [beta]~1-42~, lipopolysaccharide treatment or human Alzheimer's brain

Experimental study on the removal of sulfur compounds and siloxanes from biogas

Biogas is a renewable energy source, which can be produced by anaerobic digestion with anaerobic organisms from agriculture waste, manure, municipal waste, sewage, food waste, etc. The biogas consists primarily of methane and carbon dioxide, but also smaller amounts of nitrogen, oxygen, hydrogen and volatile organic compounds including sulfur compounds, halogenated compounds and organic silicon compounds may be present. Here, methane which is the main component in the biogas may be used as a fuel in many applications such as heating, combined heat and power systems, fuel cells, etc. For the implementation of methane, therefore, the biogas needs purification to improve its quality in most cases by removing impurities from the biogas, resulting in no corrosion and scaling problems in the applications. In the present work, a hybrid biogas purification process, consisting of a physicochemical process with an adsorption for the removal of sulfur compounds and siloxanes and a membrane separation process for the removal of carbon dioxide, has been proposed. The main focus of this study is to examine the physical properties and adsorption characteristics of adsorbents being used to remove sulfur compounds and siloxanes from the biogas. Indeed, recent studies are on the desulfurization and siloxane removal process using an activated carbon and impregnated activated carbon. However, there are many different types of sulfur compounds and siloxanes in the biogas and each may have a different reaction rate and adsorption capacity. In this study, therefore, several commercially-available adsorbents are selected to analyze their removal capacities for the main components (methane) and major impurities in the biogas. The main impurities considered in this work are hydrogen sulfide (H2S), carbonyl sulfide (COS), carbon disulfide (CS2), Octamethylcyclotetrasiloxane (D4) and Decamethylcyclopentasiloxane (D5), based on the measurements from the on-site sewage treatment plant in Incheon, Korea. In the bench-scale adsorption experiments, iron oxide, activated carbon, impregnated activated carbon and inorganic adsorbents such as zeolite and silica gel are used as adsorbents for the removal of impurities from synthetic biogas and their physical properties are analyzed with XRF, SEM and BET analyses. The experimental results show that the adsorption capacity of hydrogen sulfide in the iron oxide (IO) is superior to those of the activated carbon (AC) and impregnated activated carbon (IAC) with a relatively good adsorption capacity (Figure 1). In addition, the removal efficiency of carbonyl sulfide and carbon disulfide with the activated carbon is more effective than using the iron oxide having a very poor adsorption capacity (Figure 2). It is also shown that both activated carbon and zeolite exhibit a high adsorption capacity of siloxanes D4 and D5. Especially, in case of siloxane D5, the zeolite has a better adsorption capacity than the activated carbon (Figure 3). More detailed results will be presented at the conference. Please click Additional Files below to see the full abstract

Novel Diagnostic Model for the Deficient and Excess Pulse Qualities

The deficient and excess pulse qualities (DEPs) are the two representatives of the deficiency and excess syndromes, respectively. Despite its importance in the objectification of pulse diagnosis, a reliable classification model for the DEPs has not been reported to date. In this work, we propose a classification method for the DEPs based on a clinical study. First, through factor analysis and Fisher's discriminant analysis, we show that all the pulse amplitudes obtained at various applied pressures at Chon, Gwan, and Cheok contribute on equal orders of magnitude in the determination of the DEPs. Then, we discuss that the pulse pressure or the average pulse amplitude is appropriate for describing the collective behaviors of the pulse amplitudes and a simple and reliable classification can be constructed from either quantity. Finally, we propose an enhanced classification model that combines the two complementary variables sequentially

Novel Diagnostic Algorithm for the Floating and Sunken Pulse Qualities and Its Clinical Test

We propose a novel classification algorithm for the floating pulse and the sunken pulse using a newly defined coefficient (Cfs). To examine the validity of the proposed algorithm, we carried out a clinical test in which 12 oriental medical doctors made pairwise diagnoses on the pulses of volunteering subjects. 169 subjects were simultaneously diagnosed by paired doctors, and the diagnoses in 121 subjects were concordant, yielding an accuracy of 72% and a Matthews correlation coefficient of 0.42, which indicates reasonable agreement between doctors. Two sample T-tests showed that subjects in the sunken pulse group had significantly higher BMI and Cfs (P < .05) than those in the floating pulse group. The pulse classification by the algorithm converged with the diagnoses of paired doctors with an accuracy up to 69%. With these results, we confirm the validity of the novel classification algorithm for the floating and sunken pulses

Comments on AdS2 solutions of D=11 Supergravity

We study the supersymmetric solutions of 11-dimensional supergravity with a factor of $AdS_2$ made of M2-branes. Such solutions can provide gravity duals of superconformal quantum mechanics, or through double Wick rotation, the generic bubbling geometry of M-theory which are 1/16-BPS. We show that, when the internal manifold is compact, it should take the form of a warped U(1)-fibration over an 8-dimensional Kahler space.Comment: 11 pages, no figure, JHEP3.cl

Observation of Scarred Modes in Asymmetrically Deformed Microcylinder Lasers

We report observation of lasing in the scarred modes in an asymmetrically deformed microcavity made of liquid jet. The observed scarred modes correspond to morphology-dependent resonance of radial mode order 3 with their Q values in the range of 10^6. Emission directionality is also observed, corresponding to a hexagonal unstable periodic orbit.Comment: 4 pages, 6 figure