A three-dimensional visualization technique applied to flow around a delta wing

The visualization of flows in two dimensions by using planar laser light sheets is a commonly used technique. We extend this technique to three dimensions by rapidly scanning the laser light sheet to obtain a set of slices of the flow around a full span delta wing. The leading edge vortices, which are marked with smoke, are unburst by tangential blowing around the leading edges at angles of attack in excess of 25°. Since the measurement period is on the order of the smallest convective time scale, we obtain a virtually instantaneous set of planar cross sections of the flow. Software based on the marching cubes algorithm is used to stack the slices and reconstruct a three-dimensional surface of the smoke-seeded fluid. This surface, which corresponds to the vortices, clearly shows the qualitative effects of blowing on the delta wing flow.     

Characterisation and quantification of liposome-type nanoparticles in a beverage matrix using hydrodynamic chromatography and MALDI–TOF mass spectrometry

This paper describes the characterisation of liposome-type nanoparticles (NPs) dispersed in a beverage matrix. Characterisation is based on a two-step procedure: first, liposomes are separated on the basis of size in the nanometre range by use of hydrodynamic chromatography (HDC); second, chemical characterisation is performed by use of MALDI–TOF mass spectrometry (MS). Characterisation of three types of Coatsome liposome, a commercially available type of empty liposome, was investigated. All three liposome types, Coatsome A?=?anionic, N?=?neutral, and C?=?cationic, gave single peaks in HDC, reflecting diameters of 153, 187, and 205 nm, respectively. Subsequent MALDI–TOF MS in positive mode furnished major signals at m/z?=?734.5 ([M?+?H]⁺ adduct) and m/z?=?756.6 ([M?+?Na]⁺ adduct) of l-(α)-dipalmitoylphosphatidylcholine (DPPC) monomer and dimeric adducts at m/z?=?1468.1 and m/z?=?1490.1, respectively. MALDI–TOF MS in negative mode gave a signal at m/z?=?721.3 ([M???H]^? adduct) of l-(α)-dipalmitoylphosphatidylglycerol (DPPG), except for Coatsome C which lacks this phospholipid. After HDC separation of Coatsome A NPs the major DPPC and DPPG signals can be detected in the expected fractions by use of MALDI–TOF MS in positive and negative modes, respectively. Validation of the analytical strategy revealed linearity (R ²?>?0.99), repeatability (relative standard deviation <10 %), and reproducibility (relative standard deviation between days <10 %) were good, recovery was 61?±?5 %, and the limit of quantification was 1 mg?mL^?1 in this matrix. With 4 mg Coatsome A mL^?1 20 out of 20 samples furnished the 734.5 and 756.6 signals typical of DPPC in MALDI–TOF MS characterisation.     

Spectroscopy of two coincident charged particles emitted following bound pion absorption in 12C, 59Co and 197Au

Energy spectra and angular distributions of two coincident charged particles emitted following stopped negative pion absorption in ¹²C, ⁵⁹Co and ¹⁹⁷Au were measured. Most of the data can be understood within the framework of a pair absorption model including final-state interactions. Ground-state transitions in the missing mass spectra of ⁴H and ⁴He deduced from the αα and tα spectra of ¹²C, respectively, show that reactions involving a large part of the nucleus also occur.     

Measurement of neutron energy spectra and neutron-gamma angular correlations for the muon capture process 16O(μ−, νμxn)14, 15N

Neutron-gamma coincidence spectra have been measured for muon capture in ¹⁶O. The γ-spectrum is dominated by the ground state transitions from the $\text{3}\text{2}{}^{\mathrm{?}}\text{(6.32}\text{MeV}\text{)}\text{and}\text{1}\text{2}{}^{\mathrm{+}}\text{+}\text{5}\text{2}{}^{\mathrm{+}}\text{(5.3}\text{MeV}\text{)}$ states of ¹⁵N that are populated after the emission of one neutron. The neutron energy spectra and the neutron energy dependence of the ny angular correlation coefficient A₂ for these final states are presented. The observed transitions in ¹⁴N and the associated neutron spectra give direct evidence for the emission of two correlated neutrons. The data are discussed in terms of direct neutron emission plus emission via giant resonance intermediate states of ¹⁶N. The large yield for the emission of one and two fast neutrons is explained by a capture mechanism involving short-range nucleon-nucleon correlations.     

Proton-hole states in 115In observed in the 116Sn(d, 3He) reaction

The ¹¹⁶Sn(d, ³He)¹¹⁵In reaction has been investigated at E_d = 50 MeV. Thirteen transitions to states up to 3 MeV excitation energy were studied. The measured angular distributions were compared with DWBA calculations and transferred angular momenta and spectroscopic factors were deduced. Levels at 1.04, 2.23 and 2.52 MeV were found to be excited most likely by l = 3 angular momentum transfer in contrast to previous investigations at lower incident energies in which no l = 3 transitions have been observed.