Measurement of analyzing power for the reaction \vec p + CH_2 at polarized proton momentum of 7.5 GeV/c (ALPOM2 proposal)

An accurate data base for the analyzing power of thick CH₂ analyzers for high energy protons has been at the basis of several research efforts in a number of laboratories. Starting in the late eighties such data were collected at SATURNE in Saclay, and with the Synchrophasotron in Dubna, and led to an extensive program of study of polarization phenomena in pd interaction, either backward elastic scattering or breakup [1–6]. At about the same time it became evident that measuring polarization observables in elastic ep was going to be the best approach to determine the form factors of the proton, G _Ep and G _Mp , as had been predicted by Akhiezer and Rekalo [7].     

Radioactivity in coral skeletons and marine sediments collected from the St. Martin’s Island of Bangladesh

Journal of Radioanalytical and Nuclear Chemistry - Although the coral island ‘St. Martin’s’ serves as the most attractive place for leisure and tourism, but no data on...     

The presence of radioactive and metal contaminants in wild mushrooms grown in Chattogram hill tracts,Bangladesh

Journal of Radioanalytical and Nuclear Chemistry - Wild mushrooms are considered as bioindicators of environmental pollution. Different species of mushrooms (edible and medicinal), commonly...     

Thermodynamics of Viscous Flow of <Emphasis Type="Italic">tert</Emphasis>-Butanol with Butylamines: UNIFAC–VISCO,Grunberg–Nissan and McAllister Three Body Interaction Models for Viscosity Prediction and Quantum Chemical (DFT) Calculations

Thermodynamic activation parameters, enthalpies (ΔH ^?), entropies (ΔS ^?) and Gibbs energies (ΔG ^?) for viscous flow of the systems tert-butanol (TB)+n-butylamine (NBA), TB+di-n-butylamine (DBA) and TB+tri-n-butylamine (TBA) have been calculated from measured density and viscosity data at temperatures ranging from 303.l5 to 323.15 K over the composition range 0 ≤ x ₂ ≤ 1, where x ₂ is the mole fraction of TB. For all systems, the corresponding excess properties ΔH ^?E, ΔS ^?E and ΔG ^?E have been determined, which are negative in the whole range of composition. The observed negative excess activation properties have been accounted for in terms of dispersive forces and H-bonding. The derived properties are well represented by fourth degree polynomial equations whereas the excess properties could be fitted to third degree Redlich–Kister polynomial equations. Furthermore, the viscosities have been predicted by using the UNIFAC–VISCO model, Grunberg–Nissan model and McAllister three-body interaction model. The UNIFAC–VISCO model and Grunberg–Nissan model do not show good agreement with the experimental data, whereas the McAllister three-body interaction model shows excellent agreement for all three systems, with small average absolute percent deviations (AAD% = 0.6–2.3). The DFT-B3LYP method with the 6-311 G (d, p) basis set has been employed for the optimization of the geometry and calculation of the total energies of the pure compounds and their binary complexes.     

Potential perchlorate exposure from Citrus sp. irrigated with contaminated water

Citrus produced in the southwestern United States is often irrigated with perchlorate-contaminated water. This irrigation water includes Colorado River water which is contaminated with perchlorate from a manufacturing plant previously located near the Las Vegas Wash, and ground water from wells in Riverside and San Bernardino counties of California which are affected by a perchlorate plume associated with an aerospace facility once located near Redlands, California. Studies were conducted to evaluate the uptake and distribution of perchlorate in citrus irrigated with contaminated water, and estimate potential human exposure to perchlorate from the various citrus types including lemon (Citrus limon), grapefruit (Citrus paradise), and orange (Citrus sinensis) produced in the region. Perchlorate concentrations ranged from less than 2-9 μg/L for Colorado River water and from below detection to approximately 18 μg/L for water samples from wells used to irrigate citrus. Destructive sampling of lemon trees produced with Colorado River water show perchlorate concentrations larger in the leaves (1835 μg/kg dry weight (dw)) followed by the fruit (128 μg/kg dw). Mean perchlorate concentrations in roots, trunk, and branches were all less than 30 μg/kg dw. Fruit pulp analyzed in the survey show perchlorate concentrations ranged from below detection limit to 38 μg/kg fresh weight (fw), and were related to the perchlorate concentration of irrigation water. Mean hypothetical exposures (μg/person/day) of children and adults from lemons (0.005 and 0.009), grapefruit (0.03 and 0.24), and oranges (0.51 and 1.20) were estimated. These data show that potential perchlorate exposures from citrus in the southwestern United States are negligible relative to the reference dose recommended by the National Academy of Sciences.     

Measurement of the electric form factor of the neutron through d-->(e-->,e(')n)p at Q2 = 0.5 (GeV/c)(2)

We report the first measurement using a solid polarized target of the neutron electric form factor G(n)(E) via d-->(e-->,e(')n)p. G(n)(E) was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ( 15ND3). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find G(n)(E) = 0.04632+/-0.00616(stat)+/-0.00341(syst) at Q2 = 0.495 (GeV/c)(2).     

Measurement of G(E(p))/G(M(p)) in e(-->)p---> e(-->)p to Q(2) = 5.6 GeV(2)

The ratio of the electric and magnetic form factors of the proton G(E(p))/G(M(p)), which is an image of its charge and magnetization distributions, was measured at the Thomas Jefferson National Accelerator Facility (JLab) using the recoil polarization technique. The ratio of the form factors is directly proportional to the ratio of the transverse to longitudinal components of the polarization of the recoil proton in the elastic e(-->)p---> e(-->)p reaction. The new data presented span the range 3.5< Q(2)< 5.6 GeV(2) and are well described by a linear Q(2) fit. Also, the ratio sqrt[Q(2)] F(2(p))/F(1(p)) reaches a constant value above Q(2) = 2 GeV(2).     

Effect of Attachment Configuration on Impact Vibration Absorbers

This experimental research deals with passive vibration control of a primary mass using an impact vibration absorber (IVA). This paper is on two types of IVAs, namely, a simple IVA and a compound IVA, which have different attachment configurations for the impacting mass. The main contribution of this work was to experimentally analyze the effect of attachment configuration on IVAs. Thus, the primary objective of this research was to compare the absorption characteristics of simple and compound IVAs in case of transient and forced vibration. The secondary objective was to determine the effect of system parameters on the absorption efficiency of a compound IVA for both transient and forced vibration. It was shown that, for forced vibrations, the simple IVA (compared to the compound IVA) has more pronounced inefficient absorption region. On the other hand, the compound IVA hardly has a clear inefficient absorption region. In the respective absorption region, it is noted that the simple IVA has a more prominent vibration absorption level. Practical applications of the results are also discussed. This paper was presented at the IMAC-XXIII: a conference & exposition on structural dynamics, January 31–February 3, 2005, Orlando, Florida.