Diode laser spectroscopy of the ν3 band region of four isotopic forms of CS2

The diole laser spectrum of a natural sample of the linear molecule, CS₂, has been measured in the region 1450–1550 cm^?1. An absolute frequency calibration of approximately 0.001 cm^?1 was achieved by measuring CS₂ absorption lines relative to those of H₂O and HDO and using the absolute wave numbers of Guelachvili [J. Opt. Soc. Amer., 73, 137–150 (1983)]. Band constants were determined for the following: C³²S₂; (0, 0, 1) ← (0, 0, 0), (0, 1¹, 1) ← (0, 1¹, 0), (0, 2^0,2, 1) ← (0, 2^0,2, 0), (1, 0, 1) ← (1, 0, 0); ³⁴SC³²S; (0, 0, 1) ← (0, 0, 0): ³³SC³²S; (0, 0, 1) ← (0, 0, 0): ¹³C³²S₂; (0, 0, 1) ← (0, 0, 0).     

Metrizably fibered generalized ordered spaces

In this paper we characterize generalized ordered spaces that are metrizably fibered in terms of certain quotient spaces and in terms of the existence of special open covers. We apply our results to give a new characterization of perfect generalized ordered spaces that have a σ-closed-discrete dense subset and to give examples of GO-spaces that are, or are not, metrizably fibered.     

Magnetic resonance imaging and computed tomography in Pelizaeus-Merzbacher disease

Six patients with the classical form of Pelizaeus-Merzbacher disease (PMD) were studied with computed tomography (CT) and magnetic resonance imaging (MRI) of the brain. While final diagnosis of PMD should be made on the basis of histopathologic findings in the brain, findings in this group support the fact that MRI can be used for tentative early diagnosis when computer tomographic examination is normal or nondiagnostic. All patients had MRI findings reflecting a pattern of diffuse white matter disease that can be considered characteristic in the appropriate clinical setting.     

Diels-alder reactivity of vinylsulfoxyallenes

Vinylsulfoxyallenes 3a-c are prepared from propargylic alcohols in 47-65% yield. Vinylsulfoxyallenes undergo facile [4 + 2] cycloadditions with methyl triazolidenedione (MTAD) and singlet oxygen to afford phenylsulfinylpyridazines and spirocyclic phenylsulfinyl-2H-pyran-3(6H)-ones in excellent yields (60-90%). Spirocyclic phenylsulfinyl-2H-pyran-3(6H)-ones are oxidized to the corresponding phenylsulfones with peracid or can be epoxidized with basic hydrogen peroxide. Spirocyclic pyranone formation is thought to proceed via the rearrangement of a labile cyclic peroxide intermediate 14.     

A transportation problem formulation for the MAC Airlift Planning problem

The Military Airlift Command (MAC) is responsible for planning the allocation of airlift resources for the movement of cargo and passengers. A heuristic algorithm, the Airlift Planning Algorithm (APA), has recently been developed under subcontract to the Oak Ridge National Laboratory to assist MAC in scheduling airlift resources. In this paper, we present a transportation problem formulation which can be used as a preprocessor to the APA or as an estimator for the APA. This paper examines the robustness and sensitivity of the transportation problem formulation. In particular, the performance of the APA improves by approximately 10% when the transportation problem is used as a preprocessor for two hypothetical problems and improves by up to 50% for derived airlift constrained problems.     

A finite concave minimization algorithm using branch and bound and neighbor generation

In this article we present a new finite algorithm for globally minimizing a concave function over a compact polyhedron. The algorithm combines a branch and bound search with a new process called neighbor generation. It is guaranteed to find an exact, extreme point optimal solution, does not require the objective function to be separable or even analytically defined, requires no nonlinear computations, and requires no determinations of convex envelopes or underestimating functions. Linear programs are solved in the branch and bound search which do not grow in size and differ from one another in only one column of data. Some preliminary computational experience is also presented.     

Plant antitumour agents-XV: Isolation and x-ray crystal structure of a new antileukaemic quassinoid undulatone from Hannoa undulata

The structure of Undulatone, a new antileukaemic quassinoid from Hannoa undulata was determined by spectral means and confirmed by single crystal X-ray analysis of the methanol solvate.