Properties of unbound high-spin states in27Al

Selectively excited high-spin states in²⁷Al have been located by the reaction¹²C(¹⁶O,p)²⁷Al. The excitation functions of these states have been measured at incident energiesE _cm=18.7 to 30.1 MeV at intervals of 150 keV. They exhibit maxima of presumably non-statistical origin. At four different energies the subsequent decay of the²⁷Al states has been studied by detecting the final heavy recoils with the Munich recoil spectrometer in coincidence with the proton emitted in the first stage of the reaction. Using this new method branching ratios of theγ-, α-, andn-decay have been measured. Based on angular correlation arguments spins up to 27/2? have been determined within the experimental accuracy of 1–2?. The observations suggest a superdeformed shape of²⁷Al at least in some of the states.     

Quark-antiquark recombination in the fragmentation region

Meson production at low transverse momentum in the fragmentation region (x>0.5) in pp collisions is considered in the context of the parton model. It is shown that the quark decay process is unimportant compared to the quark-antiquark recombination process. The calculated results of the model agree very well with the experimental data on the longitudinal momentum distributions of π^± and K^± in both the shapes and the normalizations.     

Computer readable analytical chemical data - comments on a critical need

Do academics, journal editors and research funding agencies place too little emphasis on the compilation of high quality data collections? Stephen Heller and Rudolph Potenzone think so, and contrast this situation with that found in industry, where large databanks abound.     

Two nonisomorphicK-automorphisms all of whose powers beyond one are isomorphic

As in the earlier example of two nonisomorphicK-automorphisms with isomorphic square by building an appropriate skew product of aK-automorphism that is not Bernoulli with an algebraic fiber, we get all powers beyond one of the two nonisomorphic transformations to be isomorphic. Furthermore, all the isomorphism maps are finite codings of the constructed partition names.     

Biodegradable,implantable sustained release systems based on glutamic acid copolymers

Polymer pellets that contain drugs and may be implanted under the skin offer effective means for providing sustained, controlled drug therapy to humans and animals. Among the most useful drug delivery systems are those based on biodegradable polymers that ultimately are absorbed by the body — eliminating the need for their surgical removal. Copolymers of L-glutamic acid and γ-ethyl L-glutamate biodegrade to L-glutamic acid and ethanol, at rates that are determined by the initial copolymer composition. The materials are permeable to a wide range of drugs, including steroids, narcotic antagonists, peptide hormones, antimalarials, and anticancer agents. When fabricated into matrix rods or capsules, the copolymers have been used to release drugs in animals at constant rates for prolonged periods of time. p]In this study, rods composed of a blend of drug and copolymer were found to be useful for the long-term release (i.e., 6 to 24 months) of drugs having low aqueous solubility, such as progesterone and levonorgestrel. Capsules, composed of a copolymer sheath surrounding the drug, were better suited for shorter durations of release (i.e., up to 6 months) of drugs having higher aqueous solubility, such as luteinizing hormone-releasing hormone and naltrexone. The physical dimensions and copolymer compositions of either dosage form were readily varied to meet specific delivery rate and duration objectives while satisfying equally important degradation requirements.     

Calculation of light pulses with chirp in passively mode-locked lasers taking into account the phase memory of absorber and amplifier

Starting from the complete set of Maxwell's equations and density matrix equations for the atomic systems, the change of amplitude and phase of light pulses in passing through absorbing and amplifying samples has been calculated by using certain approximations. It is shown that the phase modulation originates from saturation and phase memory in off-resonance interaction. The use of the simple rate-equation approximations.is only justified if saturation dominates. The full cavity round-trip equation has been established and solved for steady-state pulses under different conditions. For the case of pulses being outside resonance with the media we take into account a linear optical element for intracavity chirp compensation in order to describe the regime, where in experiment the shortest pulses have been found.