Time dependent upward frequency shifts in the Orbitron MASER

In our experiments with the pulsed Oribtron MASER, we have noted that there is an upward chirp in frequency even though the anode voltage is decreasing. We have found theoretically that this is a natural consequence of the negative-mass instability and the chirp rate can be predicted from this theory. Experimental data we have obtained is also in good agreement with these predictions.     

Experiments on Pore Closure During Hot Isostatic Pressing and Forging

The effect of stress on pore closure was studied by hot isostatic pressing and hot forging of sintered Al₂O₃, cubic ZrO₂, and finer-grained Al₂O₃/ZrO₂ (cubic) composite materials containing pores remnant of monosized plastic spheres. For the temperature-time conditions explored, plastic deformation was the dominant mechanism for pore shape change and closure. Namely, only pores in the highly deformable two-phase material were observed to either change shape (under uniaxial forging) or shrink (during hot isostatic pressing). Large plastic strains (0.3 to 0.6, dependent on location) were required to produce pore closure under forging conditions. At temperatures where the two-phase materials were sufficiently deformable to affect pore closure, pores close to the surface would puncture as the thin web of material separating the pore from the surface was deformed into the pore. These results are discussed in terms of the common practice of finishing by hot isostatic pressing of sintered materials.     

The Organization of Product Development

This paper develops a critical perspective on the theory underlyingcontemporary product development practice. It contrasts whatis today the dominant approach to design and product development,an approach that is analytical and problem-oriented, with analternative approach that is interpretative and process-oriented.The interpretative approach views product development as enteringinto an ongoing process in which people are already engaged.It sees the interactions between the different communities involvedin product development as a set of ongoing conversations. Itsuggests the need for a set of conceptual tools for managingthis process which are quite distinct from those associatedwith the analytical approach.     

Effect of ZrO2 Inclusions on the Sinterability of Al2O3

The sinterability of Al₂O₃/ZrO₂ composite powder compacts containing 2 and 10 vol% ZrO₂ was compared to the sinterability of their single-phase constituents through constant-heating-rate experiments. The ZrO₂ inclusion phase delayed the initiation of bulk shrinkage and the temperature of maximum strain rate by 100°C. The ZrO₂ inclusion phase also significantly inhibited grain growth. These results, discussed with regard to the thermodynamics of pore disappearance, suggest that phenomena inhibiting grain growth may also inhibit densification.     

Model for Ion-Exchanged Waveguides in Glass

An analytical model describing refractive index profiles in ion-exchanged glass waveguides is presented. Polarizability, volume, and stress-state changes are accounted for. Index distribution is given in terms of known or measurable physical parameters. Model predictions compare favorably with experimental results of field-assisted ion-exchanged waveguides fabricated in 7740 borosilicate glass. Experimental characterization of the index changes includes prism coupling, microprobe, and photoelastic measurements.     

EFFECT OF PBAN ON PHEROMONE PRODUCTION BY MATED <Emphasis Type="Italic">Heliothis virescens</Emphasis> AND <Emphasis Type="Italic">Heliothis subflexa</Emphasis> FEMALES

Mated female Heliothis virescens and H. subflexa were induced to produce sex pheromone during the photophase by injection of pheromone biosynthesis activating neuropeptide (PBAN). When injected with 1 pmol Hez-PBAN, the total amount of pheromone that could be extracted from glands of mated females during the photophase was similar to that extracted from virgin females in the scotophase. The PBAN-induced profile of pheromone components was compared between mated, PBAN-injected females and virgin females during spring and fall. Virgin females exhibited some differences in the relative composition of the pheromone blend between spring and fall, but no such temporal differences were detected in PBAN-injected, mated females. Because the temporal variation in pheromone blend composition was greater for virgin females than for PBAN-injected females, PBAN can be used to determine a females native pheromone phenotype. This procedure has the advantages that pheromone glands can be extracted during the photophase, from mated females that have already oviposited.     

PERSONALITY AND TIME ATTITUDES.

ADMINISTERED SETS OF PERSONALITY AND TIME-ATTITUDE ITEMS TO 100 HOSPITALIZED PSYCHIATRIC PATIENTS, 100 PSYCHIATRIC PATIENTS IN A MENTAL HYGIENE CLINIC AND 116 COLLEGE MALES AND 192 FEMALES. THE SETS WERE SEPARATELY FACTOR ANALYZED IN THE TOTAL SAMPLE, AND THE DATA FACTOR SCORED. SUBSTANTIAL RELATIONSHIPS WERE FOUND BETWEEN PERSONALITY AND TIME-ATTITUDE FACTOR SCORES WITHIN SAMPLES, AND MODERATE RELATIONSHIPS OF BOTH KINDS WITH DIAGNOSTIC AND DEMOGRAPHIC VARIABLES. RESULTS EMPIRICALLY SUPPORT THE CONJECTURE THAT ATTITUDES TOWARD TIME REFLECT BASIC FEATURES OF THE INDIVIDUAL PERSONALITY. (24 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

OPTIMAL OPERATION OF MULTIQUALITY WATER SUPPLY SYSTEMS-III: THE Q-C-H MODEL

A new technique for optimal operation of multiquality water supply systems is proposed. The technique, which is known as a Q-C-H (flow-quality-head) model, combines previously developed Sow-quality (Q-C) and flow-head (Q-H) models for optimal operation of water supply systems. The decision variables in the model are the operation of treatment plants, pumps and valves. The model minimizes the cost of water at sources, treatment, energy, and loss of agricultural yield when water quality is low. The model uses an iterative modified projected gradient method combined with the Complex method. As in the Q-C and Q-H models, the solution method is based on decomposition, dis-aggregation/aggregation approach, involving internal and external optimization. The decision variables of the external model are the flows in the loops of the network and the removal ratios at the treatment plants. The operation of the pumps and valves are the decision variables of the internal model. The method is demonstrated by application to an example problem.