One day ahead demand forecasting in the utility industries: Two case studies

This paper describes two case studies of short-term demand forecasting for the utilities, water and gas, linked to earlier research in similar contexts. In both cases the forecast of demand has important consequences for the operations and control of productive capacity. It is shown that in these two cases extrapolative methods based on the past data history alone are outperformed by more complex multivariate approaches that include information on the effects of weather. The paper concludes with a discussion of how an organization with an important short-term forecasting problem should go about selecting an appropriate forecasting method.     

Self-Regulating Polycondensations. III. NMR Analysis of Oligomers Derived from Terephthaloyl Chloride and p-Aminobenzhydrazide

A novel method based on NMR for the characterization of oligomers formed by the reaction of terephthaloyl chloride with excess p-aminobenzhydrazide is presented. These studies have provided significant insight to the “ordering process” or “self-regulation” involved in corresponding polymerization reactions.     

Friction at the mesoscale

The organization of structures at the mesoscale is assumed to be the most important mechanism for the majority of friction types. Evidence is provided for the hypothesis that defect organization is fundamental to both tribological and internal friction.     

New insights into astrophysical jets with the atacama large millimeter array and the Karl G. Jansky very large array

Observations using the Atacama Large Millimeter Array (ALMA) and the Karl G. Jansky Very Large Array (VLA) will address gaps in our understanding of astrophysical disks, jets and outflows from young stellar objects, evolved stars and black holes. ALMA & the VLA will achieve high resolution to map small-scale structure in jets and accretion disks allowing us to explore how material is lifted off the disk and collimated into ionized jets. ALMA will also recover even the most extended emission in large-scale out-flowing molecular material, allowing a detailed study of hydrodynamic mixing and dust formation. This paper highlights those features of the ALMA & VLA telescopes that will contribute to our understanding of astrophysical jets and disks and presents new observations that demonstrate the power of these instruments.     

Effect of varying the oil phase on the behavior of pH-responsive latex-based emulsifiers: demulsification versus transitional phase inversion

Sterically stabilized polystyrene latexes (previously described by Amalvy, J. I.; et al. Chem. Commun. 2003, 1826) were evaluated as pH-responsive particulate emulsifiers for the preparation of both oil-in-water and water-in-oil emulsions. The steric stabilizer was a well-defined AB diblock copolymer where A is poly(2-(dimethylamino)ethyl methacrylate) and B is poly(methyl methacrylate). Several parameters were varied during the emulsion preparation, including the polarity of the oil phase, the latex concentration, surface concentration of copolymer stabilizer, and solution pH. Nonpolar oils such as n-dodecane gave oil-in-water emulsions, and polar oils such as 1-undecanol produced water-in-oil emulsions. In both cases, these emulsions proved to be stimulus-responsive: demulsification occurred rapidly on adjusting the solution pH. Oils of intermediate polarity such as methyl myristate or cineole led to emulsions that underwent transitional inversion on adjusting the solution pH. All emulsions were polydisperse and typically ranged from 40 to 400 microm diameter, as judged by optical microscopy and Malvern Mastersizer measurements. Critical point drying of the emulsion droplets, followed by scanning electron microscopy studies, confirmed that the latex particles were adsorbed as a single monolayer at the oil/water interface, as anticipated.     

The synthesis of 3,5-dimethylpyrazol-1-yl-vl-v-triazolo[4,5-d]pyridazines and substituted 3,5-dimethylpyrazol-1 -ylimidazo[4,5-d]pyridazines

The synthesis of 4-(3,5-dimethylpyrazol-1-yl)-v-triazolo[4,5-d]pyridazine, 4-(3,5-dimethylpyrazol-1-yl)imid-azo[4,5-d]pyridazine and several S-substituted derivatives of 4-(3,5-dimethylpyrazol-1-yl)imidazo[4,5-d]pyrid-azine-2-thiol is reported. These syntheses were carried out to provide a variety of interesting compounds for biological screening.     

Boundary effects of molecular diffusion in nanoporous materials: a pulsed field gradient nuclear magnetic resonance study

The boundary conditions of intraparticle diffusion in nanoporous materials may be chosen to approach the limiting cases of either absorbing or reflecting boundaries, depending on the host-guest system under study and the temperature of measurement. Pulsed field gradient nuclear magnetic resonance is applied to monitor molecular diffusion of n-hexane and of an n-hexane-tetrafluoromethane mixture adsorbed in zeolite crystallites of type NaX under either of these limiting conditions. Taking advantage of the thus-established peculiarities of mass transfer at the interface between the zeolite bulk phase and the surrounding atmosphere, three independent routes for probing the crystal size are compared. These techniques are based on (i) the measurement of the effective diffusivity under complete confinement, (ii) the application of the so-called NMR tracer desorption technique, and (iii) an analysis of the time dependence of the effective diffusivity in the short-time limit where, by an appropriate variation of the adsorbate and the measuring conditions, the limiting cases of reflecting and adsorbing boundaries could be considered. All these techniques are found to yield coinciding results, which are in excellent agreement with the crystal sizes determined by microscopy.