FLUKA-LIVE—an embedded framework, for enabling a computer to execute FLUKA under the control of a Linux OS

This paper describes a Linux-based OS framework for integrating the FLUKA Monte Carlo software (currently distributed only for Linux) into a CD-ROM, resulting in a complete environment for a scientist to edit, link and run FLUKA routines—without the need to install a UNIX/Linux operating system. The building process includes generating from scratch a complete operating system distribution which will, when operative, build all necessary components for successful operation of FLUKA software and libraries.Various source packages, as well as the latest kernel sources, are freely available from the Internet. These sources are used to create a functioning Linux system that integrates several core utilities in line with the main idea—enabling FLUKA to act as if it was running under a popular Linux distribution or even a proprietary UNIX workstation.On boot-up a file system will be created and the contents from the CD will be uncompressed and completely loaded into RAM—after which the presence of the CD is no longer necessary, and could be removed for use on a second computer. The system can operate on any i386 PC as long as it can boot from a CD.     

Spectrophotometric Studies of the Energy Consumed During Oxidative Degradation of D-Fructose

ABSTRACT

Mechanistic investigation of the oxidative degradation of d-fructose (D-Fruc) has been studied by spectrophotometric technique. Molecular mechanics (MM +) calculations suggest that the potential energy (PE/kcal mol^?1) of the d-fruc (opening structure) is at least three (3.71) times more stable than the PE of the cycling structure of the same matrix. The oxidation constant (K _ox) of the anionic form of the d-Fruc (Fruc-NaOH) is about seven times greater than that of the protonated form (Fruc-H₂SO₄). Therefore, the anionic form is more highly oxidizable than is the cationic form of this matrix. The limit of detection can be as low as 18 ppm (mg L^?1) of d-Fruc. This is about 60 times lower than the blood sugar level (BSL) or 100 times lower than that reported previously. The proposed procedure was applied successfully for the oxidation of D-Fruc in uni-fructose powder. The anionic form of D-Fruc (Fruc-NaOH) has the ability to store energy about 744.72 kJ g^?1 h at 608 nm in a condensed lightweight form. Kinetic parameters of the oxidative degradation of the anionic form of D-Fruc at different concentration were deduced. A number of models were used to evaluate the kinetic parameters. The mechanism of the degradation of D-Fruc is explained on the basis of kinetic parameters.     

Functionalization of multiwalled carbon nanotubes for reinforcing of poly(l-lactide-co--caprolactone) biodegradable copolymers

Up to now, synthetic polymers and biomacromolecules have been grafted or assembled onto the convex surface of carbon nanotubes (CNTs) via covalent bonds or chemisorptions. In this research, poly(l-lactide-co--caprolactone)-functionalized multiwalled carbon nanotubes (MWCNT-OH-g-PCLA)s are synthesized by in situ ring-opening copolymerization of l-lactide (LA) and -caprolactone (CL) using stannous octanoate and hydroxylated MWCNTs (MWCNT-OHs) as the initiating system. The pristine MWCNTs are modified to possess carboxyl groups and then hydroxyl groups. MWCNT-OHs are used as coinitiators to polymerize LA and CL by the surface-initiated ring-opening polymerization. The FT-IR spectra, SEM and TEM micrographs revealed that the PCLA grafted form the sidewall of MWCNTs strongly. The TGA analysis indicates that about 75 wt% of functionalized MWCNTs with PCLA belongs to grafted PCLA and the remaining 25 wt% to the initial MWCNT-OH.     

Cycloaddition of 2′-azidoethyl glycosides to fullerene[C60] under ultrasonic irradiation

The reactions of fullerene[C₆₀] with 2′-azidoethyl 2,3,4,6-tetra-O-acetyl-α-d-mannopyranoside (2a) and 2′-azidoethyl 2,3,4,6-tetra-O-acetyl-β-d-galactopyranoside (2b) under ultrasonic irradiation cause the cycloaddition of 2′-azidoethyl glycosides to fullerene[C₆₀] and lead to d-glycosyl fullerene[C₆₀] derivatives 3a and 3b, respectively. The glycosyl fullerene[C₆₀] derivatives were characterized by ¹H and ¹³C NMR, UV–vis, FAB-MS, FT-IR spectra and were a 1:1 glycoside fullerene [C₆₀]-adduct.     

FTIR-ATR investigations of an α-helix to β-sheet conformational transition in poly(l-lysine)

A promising application of the multivariate curve resolution based on alternating least squares (MCR-ALS) method is reported for the analysis of the temperature-dependent conformational changes in poly(l-lysine) (PLL). The MCR-ALS approach has enabled detection of three structural components developed during the melting experiment. Most important is an infrared signature of the intermediate component described as a mixture of native α-helical conformation and its extended forms.     

Molecular Structure and Dimerization of d-Cycloserine in the Solid State

d-cycloserine (CS) is transformed into cis-3, 6-bis(aminooxymethyl)-2, 5-piperazinedione (CS-dimer) in the solid state under a humid atmosphere. This dimerization process was followed by measuring the IR bands characteristic of CS and CS-dimer. The reaction was accelerated by the presence of increased water vapor. The X-ray analysis of CS monohydrate (CS · H₂O) revealed that the CS molecules exist as a zwitter ion where the α-amino N atom is protonated and the amide N atom is deprotonated in the crystal. Participation of water molecules was suggested in the dimerization of CS.     

Effective λN-interaction and spectroscopy of low-lying states of 1p-shell hyernuclei

A new set of the shell-model two-particle potential parameters,S ,S _N andT forp-shell hypernuclei is proposed. The set is consistent with the available data on the excited levels of ⁷ Li, ⁹ Be, ¹⁰ B, ¹² B and ^p O. The classification of low lying states and-transitions in the 1p-shell hypernuclei is discussed in terms of the {s ⁴ p ⁿ*s :JT} configurations. The feasibility for the excited bound states and for the-transitions to be observed in the spin-flip and non spin-flip single-nucleon reactions is examined in detail.The authors are indebted to R.E. Chrien for information on the experimental results [21] before publication.     

Isotope effects in the tyrosinase catalysed hydroxylation of l-tyrosine methyl derivatives

To investigate isotope effects in the hydroxylation of [3′,5′-²H₂]-α-methyl- and [3′,5′-²H₂]-N-methyl-l-tyrosine, they were synthesised using acid catalysed isotope exchange at high temperature. The kinetic and solvent deuterium isotope effects on V_max and V_max/K_m parameters of tyrosinase in its action on methylated derivatives of l-tyrosine were determined using the non-competitive spectrophotometric method. Lineweaver–Burk plots were used to consider the inhibition type of O-methyl-l-tyrosine, revealing that it is an uncompetitive inhibitor of tyrosinase.     

Isotopic dependence of electron screening in fusion reactions

The fusion reactions⁶Li(p, )³He,⁶Li(d, )⁴He, and⁷Li(p, )⁴He have been studied over the c.m. energy rangeE=10 to 1450 keV. Each reaction involved the use of hydrogen projectiles and LiF solid targets as well as Li projectiles and hydrogen molecular gas targets. In all cases the effects of electron screening on the low-energy fusion cross sections (exponential enhancement) have been observed; the effects are somewhat stronger in the case of atomicp ord projectiles compared to the case of molecularH ₂ orD ₂ gas targets. If isotopic effects on electron screening are negligible, all three reactions should exhibit the same enhancements for each set of experimental techniques. The measurements confirmed this expectation to a large extent.Supported in part by the Landesamt Nordrhein-Westfalen (IVA5-10600387), the Deutsche Forschungsgemeinschaft (Ro429/ 18-2 and Ro429/21-1), and the Comision Interministerial de Ciencia y Tecnologia (AEN90-0932)     

Hadron production inpBe interactions at 14.6 GeV/c

Invariant cross sections for the production of ^±,K ^±,p, andd inpBe interactions at 14.6 GeV/c are well reproduced by calculations carried out in the framework of the Rossendorf collision model.Communicated by: F. Lenz     

Subthreshold kaon production in Au on Au collisions at 1 GeV/u

Subthreshold kaon production in¹⁹⁷ Au+¹⁹⁷ Au collisions at 1.0 GeV/u has been investigated with the Kaon Spectrometer at SIS. At _lab =44±4 we found aK ⁺/p ratio of>3 · 10^–4 for the momentum range 650 MeV/c to 1150 MeV/c.Dedicated to Prof. Dr. P. Kienle on the occasion of his 60th birthday     

Pion-source geometry deduced from soft-pion interferometry in heavy-ion collisions at 650 A MeV

We report transverse,R _T , and longitudinal,R _L , source sizes extracted from two-pion interferometry analysis in the Au+Au and Nb + Nb interactions at 650 A MeV. For the Nb+Nb interactions, both,R _T andR _L , do not exceed the niobium nucleus radius. In the case of Au+Au collisions, the transverse size is larger than the longitudinal one being about 12 fm for the selection ofP ⁺ < 120=" mev/c.=" we=" also=" corroborate=" the=" existence=" of=" the=" previously=" reported=" specific=" three-pion=">One of us (T.S.) wishes to thank Professor M.I. Podgoretsky and Professor R.M. Weiner for interesting discussions and comments. We also wish to acknowledge remarks of Dr. B. Lörstad.     

2-Amino-4-methylpyrimidine: A simple supramolecular scaffold for carboxylic acid complexes both in solid and solution states

Studies concentrating on hydrogen bonding interactions between 2-amino-4-methylpyrimidine (AMPY) with selected dicarboxylic acids have been investigated in the solid state. Two pyrimidinium-dicarboxylate organic salts with stoichiometry 1:1 [AMPY: maleic acid] and 2:1 [AMPY:d(+)-malic acid] have been prepared and characterized by X-ray crystallographic analysis. Maleic and d(+)-malic acids were found to exhibit unique supramolecular polymeric structures with AMPY involving proton transfer to the specific ring nitrogen of AMPY. As an extension, AMPY has been used to build a receptor structure 1. Receptor 1 shows binding of dicarboxylic acids in CH₃CN and represents a marginal selectivity with d(+)-malic acid. Binding interactions were investigated by UV-vis and fluorescence studies.     

Measurement of the stopping power of Au and MgF2 for slow muons

The spectral flux densityn(T) of ^– emerging from a Au or MgF₂ moderator has been measured at low energiesT using time-of-flight. Fromn(T) the stopping powerS(T) of Au was determined for 2 keVT22 keV, and of MgF₂ for 2 keVT12 keV. For Au,S(T) is smaller than calculated values obtained from proton atomic data practically in the wholeT range (Barkas effect); at lowT S(T) approaches the calculated values. For MgF₂,S(T) agrees fairly with the calculated values above 5 keV and then drops below these values. We ascribe this dropping to the large energy gap of the MgF₂ insulator.We wish to thank H. Angerer, H. Plendl, G. Schmidt, and C.A. Schug for help with the data taking, J. Homolka for computational help, H. Hagn, and H. Weiss for technical assistance and P. Maier-Komor and R. Scherrer for manufacturing the windows and targets. The hospitality of PSI and financial support by the German Bundesministerium für Forschung und Technologie are acknowledged.     

Spin dynamics of layered triangular antiferromagnets with uniaxial anisotropy

The spin dynamics of the semiclassical Heisenberg model with uniaxial anisotropy, on the layered triangular lattice with antiferromagnetic coupling for both intralayer nearest neighbor interaction and interlayer interaction is studied both in the ordered phase and in the paramagnetic phase, using the Monte Carlo-molecular dynamics technique. The important quantities calculated are the full dynamic structure function S(q,ω)$S(\mathbf{q},\omega )$, the chiral dynamic structure function _Schi(ω)$S_{\mathrm{chi}}(\omega )$, the static order parameter and some thermodynamic quantities. Our results show the existence of propagating modes corresponding to both S(q,ω)$S(\mathbf{q},\omega )$ and _Schi(ω)$S_{\mathrm{chi}}(\omega )$ in the ordered phase, supporting the recent conjectures. Our results for the static properties show the magnetic ordering in each layer to be of coplanar 3-sublattice type deviating from 120^°${120}^{°}$ structure. In the presence of magnetic trimerization, however, we find the 3-sublattice structure to be weakened along with the tendency towards non-coplanarity of the spins, supporting the experimental conjecture. Our results for the spin dynamics are in qualitative agreement with those from the inelastic neutron scattering experiments performed recently.     

Nuclear moments and the change in the mean square charge radius of neutron deficient thallium isotopes

The hyperfine structure, isotope and isomeric shifts in the atomic transition 6p ² P _3/2–7s ² S _1/2, =535 nm have been measured for theI=7 andI=2 states of^{190, 192, 194, 196}Tl; theI=1/2 andI=9/2 states of¹⁹¹Tl and the I=7 isomer of¹⁸⁸Tl. The thallium isotopes were prepared as fast atomic beams at the GSI on-line mass separator following fusion reactions and — in some cases — subsequent-decay. The nuclear dipole moments, electric quadrupole moments and the change in the nuclear mean square charge radius are evaluated. Theuu-isotopes show an isomeric shift which changes sign between¹⁹²Tl and¹⁹⁴Tl.Dedicated to P. Armbruster on the occasion of his 60th birthday     

Nuclear and electromagnetic fragmentation of 2.25-TeV197Au nuclei

We report the first measurement of the total charge-loss cross section _tot=_em+_nuc and partial cross sections (for Z=1, 2, ..., 9) of 11.4 A GeV¹⁹⁷Au nuclei in various targets. The large Coulomb barrier for Au reduces the electromagnetic contribution _em in a Pb target to only 18% of _nuc, compared with 70% for 14.5 A GeV²⁸Si and 120% for 200 A GeV³²S. With _em taken to be Z _T ^1.8 , _nuc can be fitted with _nuc=(A _P ^1/3 +A _T ^1/3 –b)², with b=0.83 and =59 mb, essentially the same as found at energies of 1 to 2 A GeV. Electromagnetic partial cross sections for Z=1 exceed 40 mb in the Pb, Sn, Cu, and Fe targets and are substantial for larger values ofZ in the heavier targets.We are indebted to D. Beavis and the staff of the Alternating Gradient Synchrotron at Brookhaven National Laboratory for producing the beam of 11.4 A GeV Au ions, to D. Snowden-Ifft for his efforts in developing the automated scanning system, and to S. Hirzebruch for a useful discussion. This work was supported in part by the Office of Energy Research, Office of High Energy and Nuclear Physics, Division of High Energy Physics, of the Department of Energy under contract No. DEAC03-76SF00098.     

Magnetic and electronic properties of Cr- and Mn-doped SnO2: ab initio calculations

The ab initio calculations, based on the Korringa–Kohn–Rostoker (KKR) approximation method combined with the coherent potential approximation (CPA), indicated as KKR–CPA, have been used to study the stability of ferromagnetic and ferrimagnetic states, for systems that are SnO₂ doped and co-doped with two transition metals, that is, chromium and manganese. Our results indicate that the ferromagnetic state is more stable than the spin-glass state for the (Sn_1−xCr_xO₂; x = 0.07, 0.09, 0.12 and 0.15)-doped system, while the spin-glass state is more stable than the ferromagnetic state for the (Sn_1−xMn_xO₂; x = 0.02 and 0.05)-doped system. However, the ferromagnetic and/or the ferrimagnetic states are stable for the (Sn_0.98−xMn_0.02Cr_xO₂; x = 0.05, 0.09 and 0.13)-doped system depending on the Cr concentration. Moreover, we estimated the Curie temperature (T_c) for the Cr-doped tin dioxide (SnO₂), and we explained the origin of magnetic behaviour through the total density of states for different doped and co-doped SnO₂ systems.