Інтерактивний контроль при формоутворенні багатогабаритних деталей

Physical phenomenon of warping (springing) can be observed as a technological heritage after large-dimensional articles forming or curing and consequent cooling of composite articles. This phenomenon can be seen as gaps between ready article contour and forming jig contour. Deviation degree of ready article surface from theoretical contour and article dimensions has to be controlled during manufacturing. Application of auxiliary controlling jig leads to expenses and labor-manufacturability increasing. Possibility of application forming jig with inserted jet gages is considered for articles shape controlling. Such gages and realization of acoustic methods allow to control not only final article shape but also geometry on intermediate stages of manufacturing.Після формоутворення багатогабаритних листових деталей з листових механічних заготовок або полімеризації і охолодження деталей з композитних матеріалів проявляється технологічна спадковість у вигляді викривлення (пружнення). Це спостерігається у вигляді неприлягання готової деталі до формозадаючої поверхні технологічного оснащення. При контролі якості формозміни необхідно вимірювати ступінь порушення форми і розмірів. Застосування контрольної оснастки дорого і складно. Розглянуто можливість використання для контролю формозадаючої оснастки з встановленими в ній повітряними струминними датчиками. Такі датчики і застосування акустичних методів дозволяють контролювати не тільки кінцеву форму заготовки, а й форму заготовки на попередваріантних етапах формозміни

A multi-agent planning support system for assessing the role of transportation and environmental objectives in urban planning

This paper analyzes 12 city plans that were developed based on environmental-sustainability indicators using a multi-agent model. The plans are based on three city forms and four types of city scenarios, each representing a different planning concept. The environmental indicators concern pollution from transportation, while the sustainability aspects relate to accessibility to facilities. The model supports planners in identifying the best city form considering the selected performance criteria. In this case study, a compact city form, coupled with mixed land-uses, performed best. © 2014 Rachel Katoshevski-Cavari, David Katoshevski, Theo Arentze, and Harry Timmermans

A study of processes that govern the maintenance of aerosols in the marine boundary layer

We systematically evaluate the relative influence of sources and sinks of particles in the remote marine boundary layer (MBL) to elucidate the principal factors that govern MBL aerosol behavior. Processes considered include: (1) surface flux of dimethyl sulfide (DMS); (2) gas-phase oxidation of DMS to SO2; (3) gas-phase oxidation of SO2 to H2SO4; (4) mass transfer of SO2 and H2SO4 to pre-existing particles; (5) humogenous nucleation of H2SO4/H2O; (6) entrainment of air from the free troposphere; (7) deposition to the sea surface; (8) cycling of air through clouds and rain scavenging; (9) oxidation of SO2 in sea salt aerosols and cloud droplets; and (10) sea-salt particle production at sea surface. The average aerosol number concentration is found to be quite sensitive to the rate of entrainment of aerosol-containing air from the free troposphere. The path that leads to the greatest accumulation of non-sea-salt (nss) sulfate involves SO2 (rather than H2SO4) absorption into existing particles. Because of scavenging of SO2 and H2SO4 by sea-salt aerosol, a considerable fraction of nss-sulfate is internally mixed with sea-salt aerosol. Under the conditions assumed in this study, MBL aerosol number concentration is dominated by free tropospheric aerosol under virtually all conditions, 89% in the base case, and even 69% at a 17 ms-1 wind speed. Aerosol mass, on the other hand, is dominated by sea-salt particles, 62% in the base case and 98% at a wind speed of 17 m s-1. Evaporation of cloud droplets provides 4.6% of the particle number in the base case, but 28% of the particle mass. At the high nucleation rate case considered here, there is notably little change in the overall contributions to aerosol number and mass from the base case; only about 5% of the total particle number is provided by nucleation events. Variation in precipitation frequency also has only a minor effect on the overall contributions. One concludes that the MBL aerosol is remarkably robust in the face of ever-changing conditions. Free tropospheric aerosol entrainment tends to sustain particle number concentrations, and sea salt emissions maintain most of the aerosol mass. Cloud processing, while not a major contributor to aerosol number, does provide, except under high wind conditions, the order of 20% of the aerosol mass. Although nucleation occurs only infrequently and does not contribute appreciably to long-term average aerosol number or mass, nucleation is, nonetheless, the mechanism that replenishes aerosol number in brief, intense episodes when aerosol surface area levels are substantially reduced by precipitation. The relative influence of particle sources and sinks in the remote marine boundary layer (MBL) is evaluated to elucidate the principal factors governing MBL aerosol behavior. Processes considered include: dimethyl sulfide (DMS) surface flux; gas phase DMS oxidation to SO2; gas phase SO2 oxidation to H2SO4; SO2 and H2SO4 mass transfer to preexisting particles; H2SO4/H2O nucleation; air entrainment from the free troposphere; deposition to the sea surface; air through clouds cycling and rain scavenging; SO2 oxidation in sea salt aerosols and cloud droplets; and sea-salt particle production at sea surface. These processes combined result in a remarkably robust MBL aerosol in the face of ever-changing conditions