We calculate light-curves for Gamma-Ray Burst afterglows when material ejected in the explosion is confined to a jet which propagates in a medium with a power-law density profile. The observed light-curve decay steepens by a factor of Γ when an observer sees the edge of the jet. In a uniform density medium the increase in the power-law index (β) of the light-curve as a result of this edge effec...

The log-log plot of the cumulative numbers of infected and deceased cases through the progress of the 2009 H1N1 pandemic gave a relation given by the equation logY = klogX – klogN0, where Y is the cumulative number of infected cases, X the cumulative number of deaths, k the coefficient representing the slope of the curve, and N0 the value of X when the curve crosses the X axis (1). The analysis...

Mori’s “bend and break” argument was originally introduced in 1979 in order to prove Hartshorne’s conjecture, showing that (at least in characteristic 0) one can recognize projective spaces as precisely the smooth projective varieties with ample tangent bundles (here for a vector bundle E to be ample means that if P(E) is the associated projective bundle, OP(E)(1) is ample). He then applied the...

∼= P, where g(x, y, z) = 0 is a homogeneous equation of the curve Z and (λ, μ) ∈ P. Then a general curve in P is birational to an elliptic curve. Remark 1.1. The construction of pencil P can be generalized to the case when C has at most ordinary double points and the points P1, · · · , P9 are not necessarily distinct (see [3]). The pencil P is called a standard Halphen pencil. Definition 1.2. A...

Topoisomerases are ubiquitous proteins found in all three domains of life. They change the topology of DNA via transient breaks on either one or two of the DNA strands to allow passage of another single or double DNA strand through the break. Topoisomerases are classified into two types: type I enzymes cleave one DNA strand and pass either one or two DNA strands through the break before reseali...

Phenol removal from wastewater is very widely studied area of research. The practical approach for phenol removal by adsorption involves study of batch adsorption and more importantly the fixed bed operation. In the present study, various aspects of fixed bed adsorption for phenol have been discussed. The review of research carried out on this topic is presented. The phenol removal in fixed bed...

Introduction: Passage of ionizing radiation through the organs of living creatures develops clusters of damaged nucleotides inside the DNA rounds. 192Ir Gamma source is one of the most widely used sources in brachytherapy of cervical and prostate cancer. Thus, in this research, we investigated the flux of photons and its resulting secondary electrons, the single-strand break (S...