Optimal scalar Lyapunov functions for decentralised stabilisation of interconnected systems

The problem of stabilisation of interconnected linear systems is considered by means of scalar Lyapunov functions and aggregation. A sufficient condition is given for an interconnected system to be stabilised using only local state feedback. The aim is to provide the least restrictive condition possible, which is termed `optimal?, by properly choosing the state-variable weighting matrices for each subsystem.     

The dimensionality of self-esteem: II. Hierarchical facet model for revised measurement scales.

A hierarchical facet model of self-esteem proposed by R. J. Shavelson et al (see record 1978-30429-001) was partially tested in a previous study by J. S. Fleming and W. A. Watts (see record 1981-28061-001). Their 3 factors, which were labeled Self-Regard, Social Confidence, and School Abilities, corresponded to 3 of the 4 dimensions posited by Shavelson et al. Predictions of other individual-difference variables from these factors were also tested by correlational analysis. Improvements to the instrument led to a replication of their 3 factors plus 2 predicted physical factors: Physical Appearance and Physical Abilities. In the present study, with 259 undergraduates, a 2nd-order factor analysis yielded a single, superordinate factor of global self-esteem, supporting the hierarchical interpretation of the facet model. Construct validity was further examined by replication of the correlational findings of Fleming and Watts and by correlations with other measures of personality and adjustment, including a global measure of self-esteem: the Rosenberg Self-Esteem Scale. The facet model as presently operationalized measures dimensions of relevance for the intended population, but these dimensions are not so broadly defined as to be redundant with related constructs. (65 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A century of meat exports from New Zealand

In 1982 New Zealand celebrates the centenary of its frozen meat export industry. The history of refrigeration and its impact on this, New Zealand's largest industry, is outlined.     

Thermal infrared imagery of The Burning Mountain coal fire

This paper describes a study of The Burning Mountain coal fire carried out in 1971-2 using an airborne optical-mechanical-scanner operating in the infrared wavelengths, with supplementary ground temperature studies.     

A far infra-red study of conformational disorder in PTFE

The examination of the 250–350 cm^?1 region of the infra-red spectrum of polytetrafluoroethylene (PTFE) has been extended by studies of thermally degraded and sintered material. We conclude that a band at 277 cm^?1 does not arise from a true mode of the crystal but has its origin in regions where the chain has a bent conformation. Our previous speculation that bands at 292 cm^?1 and 312¹ cm^?1 (Raman active only, for the isolated chain) acquire their weak activity in the infra-red through conformational disorder is confirmed. It is likely that the conformational disorder in question arises from chain folding in the polymer crystal.     

Dihydropyrimidine dehydrogenase activity in cancer patients

Dihydropyrimidine dehydrogenase (DPD) is the major catabolic enzyme of pyrimidines and fluoropyrimidines. The clinical course of 2 patients with suspected DPD deficiency is described. Both patients had significantly delayed clearance of fluorouracil (5-FU), elevated plasma uracil concentrations, and subsequent lethal toxicity. The prevalence of DPD deficiency in the general population is unknown, but given the large number of cancer patients treated with 5-FU, it may be of great clinical significance. Lymphocytes have been previously shown to be a useful marker of systemic DPD activity. Because DPD activity has not been previously reported in a large population of cancer patients using 5-FU as the substrate, we determined DPD activity in lymphocytes from 66 patients with cancer. DPD activity was determined by a sensitive high performance liquid chromatography method. The mean DPD activity (S.D.) in 66 patients with head and neck cancer was 0.189 (0.071) nomol/min/mg protein with wide interpatient variability (range 0.058-0.357). DPD activity was not correlated to age (r = -0.164, P = 0.188). The mean DPD activity in men [0.192 (0.074)] was not significantly different from that in women [0.172 (0.057); t-test P = 0.418]. Likewise, there was no statistical difference in DPD activity in patients who had not received prior chemotherapy [0.195 (0.066)] to patients receiving one or more cycles of chemotherapy [0.186 (0.074); t-test P = 0.638].     

Reactive intermediate in the alkali-carbonate-catalysed gasification of coal char

Based on results from a variety of experimental measurements, a detailed mechanism is postulated for the action of the inorganic catalyst in char gasification. In this mechanism, a catalyst such as potassium carbonate in contact with char undergoes a chemical and physical transformation to form a molten potassium oxide film that covers the char surface. This film serves as an oxygen transfer medium between the gaseous reactant (H₂O or CO₂) and the char. At the catalyst/char interface, an oxidation-reduction reaction occurs and the anions in the catalyst react with the oxidized char to form a phenolate-type functional group that subsequently splits out CO. The anions are replenished by reaction between the oxidizing gas (H₂O or CO₂) and the oxide at the gas/catalyst interface. Net transport of oxygen from gas to char occurs by diffusion of the species in the molten catalyst film.     

Selection of lactic acid bacteria for use in vegetable fermentations

The fermentation of brined vegetables traditionally has depended upon growth of naturally occurring lactic acid bacteria to metabolize the vegetable sugars to organic acids which, together with added salt, results in preservation. Starter cultures have been used only to a limited extent commercially. However, recent efforts to improve fermentation vessels and to develop controlled fermentation methods for fermented vegetables has resulted in an increased interest in developing cultures suitable for application in such methods. Rapid and dominant growth, type and extent of acid production, salt tolerance, temperature range, CO₂ production, cell sedimentation, bacteriophage resistance, nutritional value, and ability to survive as concentrated cultures are factors to consider in developing lactic acid bacterial cultures for use in controlled fermentation of vegetables. Recent examples of efforts to improve cultures include development of nonmalate-decarboxylating strains of lactobacilli for use in cucumber fermentation and isolation of a new species of lactobacillus that produces only the L-isomer of lactic acid from the glucose for use in sauerkraut fermentation. Further improvements in starter cultures for fermented vegetables are likely when suitable genetic transfer systems are developed for selective incorporation or deletion of specific traits.     

Quantitative scanning probe microscope topographies by charge linearization of the vertical actuator

Many forms of scanning probe microscopy require a piezoelectric actuator to vary the probe-sample distance. Examples include constant-force atomic force microscopy and constant-current scanning tunneling microscopy. In such modes, the topography of the sample is reconstructed from the voltage applied to the vertical piezoelectric actuator. However, piezoelectric actuators exhibit significant hysteresis which can produce up to 14% uncertainty in the reproduced topography. In this work, a charge drive is used to linearize the vertical piezoelectric actuator which reduces the error from 14% to 0.65%.