Numerical Simulation of the Hydrodynamical Combustion to Strange Quark Matter

We present results from a numerical solution to the burning of neutron matter inside a cold neutron star into stable (u,d,s) quark matter. Our method solves hydrodynamical flow equations in 1D with neutrino emission from weak equilibrating reactions, and strange quark diffusion across the burning front. We also include entropy change due to heat released in forming the stable quark phase. Our numerical results suggest burning front laminar speeds of 0.002-0.04 times the speed of light, much faster than previous estimates derived using only a reactive-diffusive description. Analytic solutions to hydrodynamical jump conditions with a temperature dependent equation of state agree very well with our numerical findings for fluid velocities. The most important effect of neutrino cooling is that the conversion front stalls at lower density (below approximately 2 times saturation density). In a 2-dimensional setting, such rapid speeds and neutrino cooling may allow for a flame wrinkle instability to develop, possibly leading to detonation.Comment: 5 pages, 3 figures (animations online at http://www.capca.ucalgary.ca/~bniebergal/webPHP/research.php

The Strange Star Surface: A Crust with Nuggets

We reexamine the surface composition of strange stars. Strange quark stars are hypothetical compact stars which could exist if strange quark matter was absolutely stable. It is widely accepted that they are characterized by an enormous density gradient ($~10^{26}$ g/cm$^4$) and large electric fields at surface. By investigating the possibility of realizing a heterogeneous crust, comprised of nuggets of strange quark matter embedded in an uniform electron background, we find that the strange star surface has a much reduced density gradient and negligible electric field. We comment on how our findings will impact various proposed observable signatures for strange stars.Comment: 4 pages, 2 figure

Measurement of the β\beta-asymmetry parameter of 67^{67}Cu in search for tensor type currents in the weak interaction

Precision measurements at low energy search for physics beyond the Standard Model in a way complementary to searches for new particles at colliders. In the weak sector the most general $\beta$ decay Hamiltonian contains, besides vector and axial-vector terms, also scalar, tensor and pseudoscalar terms. Current limits on the scalar and tensor coupling constants from neutron and nuclear $\beta$ decay are on the level of several percent. The goal of this paper is extracting new information on tensor coupling constants by measuring the $\beta$-asymmetry parameter in the pure Gamow-Teller decay of $^{67}$Cu, thereby testing the V-A structure of the weak interaction. An iron sample foil into which the radioactive nuclei were implanted was cooled down to milliKelvin temperatures in a $^3$He-$^4$He dilution refrigerator. An external magnetic field of 0.1 T, in combination with the internal hyperfine magnetic field, oriented the nuclei. The anisotropic $\beta$ radiation was observed with planar high purity germanium detectors operating at a temperature of about 10\,K. An on-line measurement of the $\beta$ asymmetry of $^{68}$Cu was performed as well for normalization purposes. Systematic effects were investigated using Geant4 simulations. The experimental value, $\tilde{A}$ = 0.587(14), is in agreement with the Standard Model value of 0.5991(2) and is interpreted in terms of physics beyond the Standard Model. The limits obtained on possible tensor type charged currents in the weak interaction hamiltonian are -0.045 $< (C_T+C'_T)/C_A <$ 0.159 (90\% C.L.). The obtained limits are comparable to limits from other correlation measurements in nuclear $\beta$ decay and contribute to further constraining tensor coupling constants

Direct Urca neutrino rate in colour superconducting quark matter

If deconfined quark matter exists inside compact stars, the primary cooling mechanism is neutrino radiation via the direct Urca processes d->u+e+antinu_e and u+e->d+nu_e. Below a critical temperature, T_c, quark matter forms a colour superconductor, one possible manifestation of which is a condensate of quark Cooper pairs in an electric-charge neutralising background of electrons. We compute the neutrino emission rate from such a phase, including charged pair-breaking and recombination effects, and find that on a material temperature domain below T_c the pairing-induced suppression of the neutrino emission rate is not uniformly exponential. If gapless modes are present in the condensed phase, the emissivity at low temperatures is moderately enhanced above that of completely unpaired matter. The importance of charged current pair-breaking processes for neutrino emission both in the fully gapped and partially gapped regimes is emphasised.Comment: 5 pages, 2 figures; to appear in Phys. Rev. C (Rapid Comm.

Quark Matter in Neutron Stars: An apercu

The existence of deconfined quark matter in the superdense interior of neutron stars is a key question that has drawn considerable attention over the past few decades. Quark matter can comprise an arbitrary fraction of the star, from 0 for a pure neutron star to 1 for a pure quark star, depending on the equation of state of matter at high density. From an astrophysical viewpoint, these two extreme cases are generally expected to manifest different observational signatures. An intermediate fraction implies a hybrid star, where the interior consists of mixed or homogeneous phases of quark and nuclear matter, depending on surface and Coulomb energy costs, as well as other finite size and screening effects. In this brief review article, we discuss what we can deduce about quark matter in neutron stars in light of recent exciting developments in neutron star observations. We state the theoretical ideas underlying the equation of state of dense quark matter, including color superconducting quark matter. We also highlight recent advances stemming from re-examination of an old paradigm for the surface structure of quark stars and discuss possible evolutionary scenarios from neutron stars to quark stars, with emphasis on astrophysical observations.Comment: 15 pages, 1 figure. Invited review for Modern Physics Letters

GSM Based Health Assistant for People with Chronic Diseases

A GSM based health assistant for people with chronic diseases proposes and implements a prototype to help people with chronic diseases. The system is composed of two components namely, wearable body area network and a microprocessor unit with GSM and GPS. This project can track certain chronic diseases namely, heart problems, asthma, apart from the chronic diseases can also track blood pressure with sensors namely, electrocardiogram (ECG) sensor, temperature sensor, heart beatsensor and blood pressure sensor. This project keeps track of the readings from the sensors and if there are some abnormalities it would send messages via GSM stored in SIM.The location of the patient can be sent using GPS

Evaluation of pharmacotherapy in neonatal and pediatric intensive care unit of a south Indian tertiary care hospital: a prospective observational study

Background: Evaluating the pharmacotherapy is essential at neonatal intensive care unit (NICU) and pediatric intensive care unit (PICU) to identify and understand pattern and variability in drug use in polypharmacy, also to promote interventions that will improve patient outcomes.Methods: In our study, we audited pharmacotherapy of 300 neonates and 100 pediatric patients admitted to NICU and PICU from November 2018 to February 2019. WHO-CORE prescribing indicators, WHO-ATC system and WHO-ICD 10th version was used to evaluate pharmacotherapy and to understand the pattern and extent of medication use and to systematically classify drugs and diseases respectively.Results: A total of 1207 medications containing 34 unique active ingredients were prescribed for 300 neonates with an average of 4.02 (±2.0) drugs per neonate admitted to NICU and the most prescribed drugs were anti-infectives for systemic use 799. A total of 976 medications containing 69 unique active ingredients were prescribed with an average of 9.76 (±3.81) per pediatric patients admitted to PICU with anti-infectives for systemic use 331 tops the list. More than 75% of drugs was prescribed in generic name with 98% constant availability of key drugs at intensive care unit.Conclusions: This study substantiates the need for reinforcement of institutional antibiotic policies as antibiotics are widely prescribed and there is an increase trend of antibiotic resistance at critical care unit, assessment of WHO core prescribing indicators are reflective of quality care revealing the awareness about strict monitoring of pharmacotherapy

Health Systems Global, the new international society for health systems research

I see starting a new international society for health systems research as a step towards renewing our collective commitment to global health goals; in particular I see the proposed society as marking a commitment to equitable universal health care. From my perspective it is important that we are clear on the values that underpin the development of this new society. In addition, the society needs a clear strategy to help achieve this goal, in particular we need to first identify who is the target audience or constituency for the society; and second, the tools through which the society will work and how the society will engage with its audience.Fil: Kraushaar, D.. No especifíca;Fil: Kieny, M. P.. Organizacion Mundial de la Salud; ArgentinaFil: Lazarus, J. V.. Health Systems Global; Estados UnidosFil: Bermejo, R.. University Of The Philippines; FilipinasFil: Abimbola, S.. National Primary Health Care Development Agency; NigeriaFil: Prashanth, N.. Institute Of Public Health; IndiaFil: Flores, W.. Center For The Study Of Equity And Governance In Health; GuatemalaFil: Freddie Ssengooba. Makerere University School Of Public Health; UgandaFil: Maceira, Daniel Alejandro. Centro de Estudios de Estado y Sociedad; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin