Search for substructure in pp total cross section in the 2200 MeV mass region

The $\text{p}$p total cross section was measured from 2130 to 2250 MeV with mass resolution 2.25 MeV (FW). No fine structure was found with σΓ above the statistical limit of 7 MeV mb. A spin J particle coupled to the $\text{p}$p system must have partial width less than $\text{1.8}\text{(2J+1)}$ MeV.     

A total energy trigger at large angles used in a calorimetric study of 150 GeV and 300 GeV pion and proton interactions on hydrogen

Hard hadronic scattering was studied by selecting 150 GeV and 300 GeV π^?p and pp events with large energy in a 240 cell calorimeter covering 452 to 1352 in the c.m.s. polar angle and the full 2π azimuth. A downstream calorimeter measured the remaining energy flow at smaller angles. For large energy deposited in the segmented calorimeter the proton induced cross section drops below the pion induced cross section, as expected in a constituent scattering picture. However, neither a simple energy scaling of the cross section nor a dominant jet structure of the events is observed. No evidence was found for recently proposed higher-twist mechanisms leading to events     

Annihilation and topological cross sections forpp and\bar p p interactions at 200 GeV/c

The results of an analysis of streamer chamber data from the NA5 experiment are presented. Topological cross sections forpp and \(\bar p\) p interactions and strange neutral particle production at 200 GeV/c have been measured and ( \(\bar p\) p?pp) difference cross sections have been determined. Multiplicity moments were calculated.     

Model-based near-wall reconstructions for immersed-boundary methods

In immersed-boundary methods, the cost of resolving the thin boundary layers on a solid boundary at high Reynolds numbers is prohibitive. In the present work, we propose a new model-based, near-wall reconstruction to account for the lack of resolution and provide the correct wall shear stress and hydrodynamic forces. The models are analytical versions of a generalized version of the two-layer model developed by Balaras et al. (AIAA J 34:1111–1119, 1996) for large-eddy simulations. We will present the results for the flow around a cylinder and a sphere, where we use Cartesian and cylindrical coordinate grids. We will demonstrate that the proposed treatment reproduces very accurately the wall stress on grids, which are one order of magnitude coarser compared to well-resolved simulations.     

A study of high transverse energy interactions of 150 and 300 GeV pions and protons on a hydrogen target using a large acceptance calorimeter

Interactions of 150 GeV pions and 300 GeV pions and protons on hydrogen which result in final states with large transverse energy in the central rapidity region ?0.88 < y < 0.67 were studied with a calorimeter trigger. The dependence of the cross section on the azimuthal acceptance of the trigger, on the beam energy and on the incident particle type and the jet properties of the events were investigated. No dominant two-jet structure was found. Nevertheless, the parton spectrum in the colliding hadrons appears to be relevant for large transverse energy reactions.     

Interactions between selected bile salts and Triton X-100 or sodium lauryl ether sulfate

Background

Sequential injection chromatography (SIC) is a new alternative separation technology. It has some advantages over high performance liquid chromatography (HPLC) regarding simplicity, inexpensiveness, portability, ease of use, maintenance requirement and operation time. In contrast, SIC has had suffered from some limitations.

Results

The current work involves four achievements. (a) One of the limitations of SIC has been overcome. A higher pressure resistant selection valve with additional ports was installed in an SIC system. This development allows propelling solution without showing solution leakage. (b) A new inexpensive rapid and green method for the separation and quantification of propranolol (PRP) and hydrochlorothiazide (HTZ) in their formulations was optimized and validated. (c) A miniaturized multi-channel fiber optic detector was coupled with the newly developed SIC system to detect PRP and HTZ at 270 and 290 nm, respectively. This issue enhanced the sensitivity rather than using a single-channel detector. (d) A comparative study on the efficiency of the SIC method with that of previous HPLC methods was conducted.

Conclusions

Besides the benefits of the instrumentation of SIC, the proposed method is rapider and more reagent-saving than previous HPLC methods. The total volume of consumed reagents and sample was 4.04 mL. The sample frequency was 22 samples/h. Other such analytical characters of the SIC method as resolution, peak symmetry, numbers of theoretical plates, linearity range, accuracy, precision and limits of detection and quantification recorded comparable results.     

Solubilization of fullerene C60 in micellar solutions of different solubilizers

Fullerene (C₆₀), the third carbon allotrope, is a classical engineered material with the potential application in biomedicine. However, extremely high hydrophobicity of fullerene hampers its direct biomedical evaluation and application. In this work, we investigated the solubilization of fullerene using 9 different solubility enhancers: Tween 20, Tween 60, Tween 80, Triton X-100, PVP, polyoxyethylene (10) lauryl ether, n-dodecyl trimethylammonium chloride, myristyl trimethylammonium bromide and sodium dodecyl sulphate and evaluated its antioxidant activity in biorelevant media. The presence of C₆₀ entrapped in surfactant micelles was confirmed by UV/VIS spectrometry. The efficacy of each modifier was evaluated by chemometric analysis using experimental data for investigating the relationship between solubilization and particle size distribution. Hierarchical clustering and principal component analysis was applied and showed that non-ionic surfactants provide better solubilization efficacy (>85%). A correlation was established (r = 0.975) between the degree of solubilization and the surfactant structure. This correlation may be used for prediction of C₆₀ solubilization with non-tested solubility modifiers. Since the main potential biomedical applications of fullerene are based on its free radical quenching ability, we tested the antioxidant potential of fullerene micellar solutions. Lipid peroxidation tests showed that the micellar solutions of fullerene with Triton and polyoxyethylene lauryl ether kept high radical scavenging activity, comparable to that of aqueous suspension of fullerene and BHT. The results of this work provide a platform for further solubilization and testing of pristine fullerene and its hydrophobic derivatives in a biological benign environment.