Uncertainty in Measurements and Chemical Analysis

Standard documents introducing the notion of uncertainty in measurements into the common practice of assessing the results of chemical analysis are considered and criticized.     

Brueckner calculations in harmonic oscillator basis

The binding energy (b.e.), r.m.s. radius and charge form factor of the⁴He nucleus are calculated for the Hamada-Johnston potential using the method developed in part I of this study. The single-particle spectrum is derived from that of a harmonic oscillator by means of an overall shiftC and state-dependent shifts _h of occupied levels. The's are chosen self-consistently and the dependence of results onC and oscillator frequency is examined. Third-order diagrams in the BG expansion for energy are explicitly calculated (except those belonging to the three-particle cluster) and their importance for getting a weak dependence of the b.e. onC is demonstrated. Dependence on remains rather strong; arguments are given in favour of the choice of that minimizes second-order diagrams. Effects due to the motion of the centre of mass of the nucleus are eliminated by subtracting T _CM calculated up to the second order, the usual zero-order approximation of T _CM being shown to overestimate the b.e. by 3–5 MeV. The computed b.e. and r.m.s. radius represent about 50% and 110% of experimental values respectively. The form factorF _ch(q) was computed for 0q ²20 fm^–2; the first-order approximation is a good fit to experimental data, while in the second order diagrams appear that worsen the fit forq ² > >10 fm^–2.The author thanks Professor I. Úlehla for stimulating discussions. The help of dr. J.Hoejí, who calculated a part of higher order diagrams, is gratefully acknowledged.     

Canady Cold Helios Plasma Reduces Soft Tissue Sarcoma Viability by Inhibiting Proliferation,Disrupting Cell Cycle,and Inducing Apoptosis: A Preliminary Report

Soft tissue sarcomas (STS) are a rare and highly heterogeneous group of solid tumors, originating from various types of connective tissue. Complete removal of STS by surgery is challenging due to the anatomical location of the tumor, which results in tumor recurrence. Additionally, current polychemotherapeutic regimens are highly toxic with no rational survival benefit. Cold atmospheric plasma (CAP) is a novel technology that has demonstrated immense cancer therapeutic potential. Canady Cold Helios Plasma (CHCP) is a device that sprays CAP along the surgical margins to eradicate residual cancer cells after tumor resection. This preliminary study was conducted in vitro prior to in vivo testing in a humanitarian compassionate use case study and an FDA-approved phase 1 clinical trial (IDE G190165). In this study, the authors evaluate the efficacy of CHCP across multiple STS cell lines. CHCP treatment reduced the viability of four different STS cell lines (i.e., fibrosarcoma, synovial sarcoma, rhabdomyosarcoma, and liposarcoma) in a dose-dependent manner by inhibiting proliferation, disrupting cell cycle, and inducing apoptosis-like cell death.     

Implications in the use of sputtering for layer removal: the system Au on Si

Au films deposited on Si substrates have been sputtered by 20 and 100 keV Ar bombardment, respectively. Bombardment-induced intermixing of Au and Si was observed at film thicknesses considerably larger than the projectile range. Due to radiation-enhanced diffusion, the partial sputtering yield of Au from Si-Au alloys decreases with increasing fluence. Complete removal of Au from Si is impossible if Ar ions are used for sputtering.     

On the tensor product of supersingleton representations ofosp(1, 2n)

The tensor product of two supersingleton representations _n of the Lie superalgebraosp (1, 2n) is studied forn2. The main results are as follows: (a) anticommutators and commutators of the odd generators in _{n n} form a skew-symmetric representation of the Lie algebrau(n, n); (b) simple explicit form of all irreducible components of _{n n}, which are labelled by a single parameterJ=0, 1, ..., has been found. Each of them is a^*-representation ofosp (1, 2n) for which assertion (a) is valid. The dimension of its vacuum subspace equals , i.e., the nondegenerate vacuum occurs for J=0 only. Basic property of this family of irreducible^*-representations of osp(1, 2n) are analogous to those of massless representations of osp(1, 4).Dedicated to Academician Václav Votruba on the occasion of his eightieth birthday.     

Precise half-life measurements for 38Ca and 39Ca

The half-lives of ³⁸Ca and ³⁹Ca have been measured at ISOLDE of CERN. The REXTRAP facility was used to prepare ultra-clean samples of radioactive nuclei for precision decay spectroscopy. ³⁸Ca is one of the T _z = - 1 , 0⁺ $ \rightarrow$ 0⁺ $ \beta$ -emitting nuclides used to determine the vector coupling constant of the weak interaction and the V_ud quark-mixing matrix element. The result obtained, T _1/2 = 443.8(19) ms, is four times more precise than the average of previous measurements. For ³⁹Ca , a half-life of T _1/2 = 860.7(10) ms is obtained, a result in agreement with the average value from the literature.     

Breather Solutions in Periodic Media

For nonlinear wave equations existence proofs for breathers are very rare. In the spatially homogeneous case up to rescaling the sine-Gordon equation \({\partial^2_t u = \partial^2_x u - \sin (u)}\) is the only nonlinear wave equation which is known to possess breather solutions. For nonlinear wave equations in periodic media no examples of breather solutions have been known so far. Using spatial dynamics, center manifold theory and bifurcation theory for periodic systems we construct for the first time such time periodic solutions of finite energy for a nonlinear wave equation

$ s(x) \partial^2_t u(x,t) = \partial^2_x u(x,t) - q(x) u(x,t)+ r(x)u(x,t)^3, $

with spatially periodic coefficients s, q, and r on the real axis. Such breather solutions play an important role in theoretical scenarios where photonic crystals are used as optical storage.

     

Marginal singularities,almost invariant sets,and small perturbations of chaotic dynamical systems

For a class of piecewise monotone locally noncontracting maps f:X-->X with small "traps" Y( varepsilon ) subset, dbl equals X (diam(Y( varepsilon )) infinity conditional probabilities that f(n+1)x in X\Y( varepsilon ) if x,fx,.,f(nx) in X\Y( varepsilon ) and the point x is chosen at random. Also proven is the convergence of &mgr;( varepsilon ) to smooth f-invariant measures as varepsilon -->0. By means of this construction, the numerical phenomenon of the convergence of histograms of trajectories of maps with marginal singularities to densities of nonfinite smooth invariant measures in the computer modeling was investigated.     

Study of 19Na at SPIRAL

The excitation function for the elastic-scattering reaction p( ¹⁸Ne, p) ¹⁸Ne was measured with the first radioactive beam from the SPIRAL facility at the GANIL laboratory and with a solid cryogenic hydrogen target. Several broad resonances have been observed, corresponding to new excited states in the unbound nucleus ¹⁹Na. In addition, two-proton emission events have been identified and are discussed.