Algorithms for Greechie Diagrams

We give a new algorithm for generating Greechie diagrams with arbitrary chosennumber of atoms or blocks (with 2, 3, 4, . . . atoms) and provide a computerprogram for generating the diagrams. The results show that the previous algorithmdoes not produce every diagram and that it is atleast 10⁵ times slower. We alsoprovide an algorithm and programs for checking Greechie diagram passage byequations defining varieties of orthomodular lattices and give examples fromHilbert lattices. We also discuss some additional characteristics of Greechiediagrams.     

Measurement of excitation functions in the reactions 197Au(11C, xn)208-xAt using a radioactive 11C beam

A light-element radioactive ion-beam capability has been developed at the LBNL 88-Inch Cyclotron. The system is based on the coupled-cyclotrons method and utilizes short-lived species, e.g., 11C, 14O, 13N produced by (p,n) and (p,alpha) reactions at the LBNL Biomedical Isotope Facility Cyclotron. In a first experiment, 197Au(11C,xn)208-xAt excitation functions have been measured for energies ranging from the Coulomb barrier up to 110 MeV using a beam of 11C with intensities up to (1-2)x10(8) ions/sec on target. The results of this experiment are compared to measurements of 197Au(12C, xn)209-xAt excitation functions.     

Synthesis of 2-Acetoxy-2-Methoxy-4-Acetoxymethyl-3,5-Cyclohexadien-1-One by Lead Tetraacetate Oxidation of Homovanillic Acid

An efficient synthesis of the title compound is achieved when homovanillic acid is reacted with lead tetraacetate.     

Morphing of curved corrugated shells

Thin sheet materials of low bending stiffness but high membrane stiffness are often corrugated in order to achieve improvements of several orders of magnitude in bending stiffness with only minimal increases in weight and cost. If these corrugated sheets are initially curved along the corrugations, much of this stiffness gain is lost. In return, the sheets are then capable of significant elastic changes in shape overall, including large changes in overall Gaussian curvature. These shape changes are described here by non-linear and coupled kinematical relationships, which are verified against experiment and finite-element simulations. It is found that gross simplifications can be made about the large displacement behaviour of such shells without a loss of accuracy.     

Attomole protein analysis by CIEF with LIF detection

We have coupled CIEF with an LIF detector that is based on a post‐column sheath flow cuvette. We employed Chromeo P503 as a fluorogenic reagent to label proteins before analysis. This reagent reacts with the ε‐amine of lysine residues, preserving the cationic nature of the residue; labeled proteins generate extremely sharp peaks in CIEF. A set of four standard proteins generated a linear relationship between migration time and pI. A protein homogenate prepared from a Barrett's esophagus cell line resolved over 100 components in a 40 min separation. Detection limits for Chromeo P503‐labeled β‐lactoglobulin were 5 amol injected into the capillary. Fluorescent impurities present in the ampholytes generated a large background signal that degraded the detection limit by four orders of magnitude compared with other forms of capillary electrophoresis with this detector.     

Diffuse reflection and polarization modulation FT-IR spectrometry of surface species

Summary Two techniques for measuring the infrared spectra of adsorbed species on surfaces of different types are described. Diffuse reflectance spectra of species adsorbed on powdered substrates with a high surface area can be measured with an exceptionally high signal-to-noise ratio. The technique is illustrated by the adsorption of carbon monoxide on rhodium supported on alumina at metal loadings between 0.1 and 10%. Some doubt is cast on previous band assignments for adsorbed CO molecules. Grazing incidence reflection-absorption spectrometry can be used to measure the spectra of molecules on flat metallic substrates of very low surface area. Attempts to develop a technique for observing the intermolecular vibration between the adsorbate and the substrate using a unique triple modulation approach are discussed.

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FT-IR-Spektrometrie mit diffuser Reflexions- und Polari-sations-Modulation von Adsorbaten an Oberflächen

Zusammenfassung Zwei Techniken zur Messung von Infrarot-Spektren von Adsorbaten verschiedener Art werden beschrieben. Diffuse Reflexionsspektren von Adsorbaten an pulverförmigen Substraten mit einer großen Oberfläche können mit einem außerordentlich großen Signal-zu-RauschVerhältnis gemessen werden. Als Beispiel dient die Adsorption von Kohlenstoffmonoxid an Rhodium auf Aluminiumoxid bei Metallgehalten von 0,1 bis 10%. Einige Zweifel an früheren Bandzuweisungen für adsorbierte CO-Moleküle werden geäußert. Reflexions-Absorptions-Spektrometrie mit streifendem Einfall kann zur Messung der Spektren von Molekülen an flachen metallischen Substraten mit sehr geringer Oberfläche benutzt werden. Versuche zur Entwicklung einer Technik für die Beobachtung der intermolekularen Schwingungen zwischen dem Adsorbaten und dem Substrat mittels einer einzigartigen Dreifach-Modulationstechnik werden diskutiert.