Sustaining supercooled mixed phase via resonant oscillations of the order parameter

We investigate the dynamics of a first order transition when the order parameter field undergoes resonant oscillations, driven by a periodically varying parameter of the free energy. This parameter could be a background oscillating field as in models of pre-heating after inflation. In the context of condensed matter systems, it could be temperature $T$, or pressure, external electric/magnetic field etc. We show that with suitable driving frequency and amplitude, the system remains in a type of mixed phase, without ever completing transition to the stable phase, even when the oscillating parameter of the free energy remains below the corresponding critical value (for example, with oscillating temperature, $T$ always remains below the critical temperature $T_c$). This phenomenon may have important implications. In cosmology, it will imply prolonged mixed phase in a first order transition due to coupling with background oscillating fields. In condensed matter systems, it will imply that using oscillating temperature (or, more appropriately, pressure waves) one may be able to sustain liquids in a mixed phase indefinitely at low temperatures, without making transition to the frozen phase.Comment: 17 pages, 7 figures, Expanded version with more detail

Coping with Macular Degeneration: Three Case Studies

Educational Objectives 1. Learn about the diagnosis and available treatments for Age Related Macular Degeneration (AMD). 2. Explain the differences between Dry and Wet AMD. 3. Understand the impact of vision loss on the lives of older adults

EXTRACTION, BIOACTIVITIES, PHYTOCHEMICAL INVESTIGATION AND IN-VIVO TOXICITY STUDIES OF MESUA FERREA L. STAMENS

Objective: To investigate in-vitro antibacterial and free radical scavenging potentials of Mesua ferrea L. stamens which are used in traditional medicinal preparations along with their phytochemical investigation and in-vivo toxicity studiesMethods: Various extracts of M. ferrea stamens were prepared by kinetic maceration method using four organic solvents. Potent antibacterial n-hexane extract of stamens was selected in the preliminary screening for antibacterial activity which was performed by an agar diffusion method for further studies. Quantification of antibacterial activity of n-hexane extract was carried out using broth microdilution method as per CLSI guidelines. Phytochemical investigations of the same extract were performed using qualitative tests for the detection of various phytochemical groups and Libermann-Burchard colorimetric assay for determination of total terpenoid content. In-vivo safety of the extract was determined by acute oral toxicity studies in mice as per OECD guidelines test no.420.Results: n-hexane extract of M. ferrea stamens was found most potent amongst other extracts studied for antibacterial activity; moreover it exhibited bactericidal activity against selected bacterial pathogens. The same extract exhibited good free radical scavenging activity in DPPH assay (IC50 value = 66.3 µg/ml). Phytochemical investigation of extract revealed presence of sterols, terpenoids and volatile oil components and the total terpenoid content was estimated as 102.8 mg/ml of dried extract (in terms of lupeol equivalents). The extract was found safe in mice in acute oral toxicity studies.Conclusion: M. ferrea stamens exhibited broad spectrum antibacterial activity along with good free radical scavenging potential and in-vivo safety which encourage further studies in the area.Â

The Role of Silicon Content on Environmental Degradations of T91 Steels

T91 grade steels showed a gradual enhancement in tensile ductility at ambient temperature due to an increase in Si content from 0.5 to 2.0 weight percent (wt.%). However, the ultimate tensile strength was reduced only above 1.5 wt.% Si. The corrosion potential became more active in an acidic solution with increasing temperature. The cracking susceptibility in a similar environment under a slow-strain-rate (SSR) condition was enhanced at higher temperatures showing reduced ductility, time to failure, and true failure stress. Cathodic potentials applied to the test specimens in SSR testing caused an enhanced cracking tendency at 30 and 60°C, suggesting hydrogen embrittlement as a possible mechanism of failure. Cracking of precracked and wedge-loaded double-cantilever-beam specimens was enhanced at higher initial stress intensity factors. In general, steels with 2.0 wt.% Si showed inferior corrosion resistance. A combination of cleavage and intergranular brittle failure was seen in the tested specimens depending on the type of testing

Fiction contract: its importance in simulation-based medical education

Simulation-based education has become an integral part of education and training in high-risk professions and disciplines such as aviation, aerospace, military, nuclear power plants, medicine and healthcare. In the last decade, medical simulation has globally emerged as a powerful instructional technique across various specialties and disciplines. Despite its increasing popularity and various advantages, simulation-based medical education (SBME) poses a unique challenge, that is, realism. This is where the concept of fiction contract or suspension of disbelief comes into the picture. In this article we provide an overview of fiction contract in SBME including how can it be effectively addressed during training

A Review of Clustering Algorithms for Clustering Uncertain Data

Clustering is an important task in the Data Mining. Clustering on uncertain data is a challenging in both modeling similarity between objects of uncertain data and developing efficient computational method. The most of the previous method for clustering uncertain data extends partitioning clustering methods and Density based clustering methods, which are based on geometrical distance between two objects. Such method cannot handle uncertain objects that are cannot distinguishable by using geometric properties and Distribution regarding to object itself is not considered. Probability distribution is an important characteristic is not considered during measuring similarity between two uncertain objects. The well known technique Kullbak-Leibler divergence used to measures the similarity between two uncertain objects. The goal of this paper is to provide detailed review about clustering uncertain data by using different methods & showing effectiveness of each algorithm

Boron Nitride Nanotubes for Space Radiation Shielding

Soon after Armstrong`s left foot touched the surface of the moon in July 21, 1969, Mars seemed to be the next target for any future human space explorations. Although during these forty five years, advances in different fields of science like materials, electronics and space resulted in regular presence of satellites, space explorers and even human in space stations but any long travel including mission to the Mars has been limited by space radiation due to its effect on materials, electronics and astronauts