Liquid immersion apparatus for minute articles

Apparatus is disclosed for immersing minute integrated circuit chips in an etching solution in manufacturing integrated circuits during research and development. The apparatus includes a holder, having a handle and basket support for carrying a removable unitary basket and lid structure where fluid flow-through passages are formed, and wherein graduated openings in the handle provide for adjustably supporting the basket in a breaker at a desired level

I Will Try

https://digitalcommons.library.umaine.edu/mmb-vp/1725/thumbnail.jp

Laboratory observation of a nonlinear interaction between shear Alfv\'{e}n waves

An experimental investigation of nonlinear interactions between shear Alfv\'{e}n waves in a laboratory plasma is presented. Two Alfv\'{e}n waves, generated by a resonant cavity, are observed to beat together, driving a low frequency nonlinear psuedo-mode at the beat frequency. The psuedo-mode then scatters the Alfv\'{e}n waves, generating a series of sidebands. The observed interaction is very strong, with the normalized amplitude of the driven psuedo-mode comparable to the normalized magnetic field amplitude ($\delta B/B$) of the interacting Alfv\'{e}n waves.Comment: 10 pages, 4 figures, submitted to Phys. Rev. Let

Analyses of shocked quartz at the global K-P boundary indicate an origin from a single, high-angle, oblique impact at Chicxulub

Accepted versio

The District Role in Instructional Improvement

Are changing conditions affecting the capacity of districts to provide focus, to coordinate support, and to scale up successful reforms? From a study of the roles played by central office staff members in shaping and supporting instructional reforms in three large urban districts, the authors derive an answer

Evaluation results of a 3D virtual environment for internet-accessible physics experiments

In the science of physics the interrelation of physical theory, model and experiement is hard to comprehend, therefore group learning becomes more important. This fact, combined with the opportunity to work on practical experiences over distance in a collaboratively way, has raised worldwide the interest of creating new learning environments based on 3D virtual worlds.This paper outlines an evaluation that was performed to determine whether the addition of collaborative virtual learning environment (CVLE) to an internet-accessible physics experiment (iLab) would improve learning experience. We wanted to assess if the developed CLVE helps participants to achieve a better understanding of physics phenomena. Within this CLVE avatars represent learners and they are able to communicate and collaborate in a way similar to real life in order to perform physics experiments using the TEAL simulation toolkit. One of the major findings of this evaluation indicates that the reconsideration of design and additional items at the 3D visualization could further improve the learning process in the CLVE in a more effective way

Environmental incomes and rural livelihoods : a global-comparative assessment

Various case studies have suggested that environmental incomes from forests and other vegetation types are important for rural households in developing countries. However, in most large-scale household surveys these income sources are either underreported or ignored, hence there has been a lack of evidence to support the wider applicability of that claim. This paper reports data from the Poverty Environment Network (PEN), which has gathered comparable income data from about 8,000 households in 360 villages and 58 sites, spread over 24 developing countries. The data collection involved a careful, quarterly recording of all forest and environmental uses, as well as other major income sources over one full year. We find that forest income on average constitutes about one fifth of total household income, while adding other environmental income brings the share to more than one fourth – about the same as incomes from growing crops. Environmental resources and agricultural crops are the two main sources of livelihoods in the survey sites. As expected, forest reliance (share of forest income in total household income) is higher for the poorer income quintiles, but the differences are less pronounced than what was found in most previous studies. We also find that safety net and seasonal gap-filling functions may be less important that often assumed. Ignoring environmental incomes in income surveys and in rural development planning would in quantitative terms amount to ignoring that farmers grow crops. Agricultural area expansion into forests and other vegetation types may well come to increase household incomes, but corresponding income losses from losing forest cover and forest degradation could be larger than previously assumed. Depriving poor people of access to forest product extraction, for instance through highly exclusionary conservation policies, could jeopardize the livelihoods of people depending on these resources

Boundary-layer friction in midlatitude cyclone

Results from an idealized three-dimensional baroclinic life-cycle model are interpreted in a potential vorticity (PV) framework to identify the physical mechanisms by which frictional processes acting in the atmospheric boundary layer modify and reduce the baroclinic development of a midlatitude storm. Considering a life cycle where the only non-conservative process acting is boundary-layer friction, the rate of change of depth-averaged PV within the boundary layer is governed by frictional generation of PV and the flux of PV into the free troposphere. Frictional generation of PV has two contributions: Ekman generation, which is directly analogous to the well-known Ekman-pumping mechanism for barotropic vortices, and baroclinic generation, which depends on the turning of the wind in the boundary layer and low-level horizontal temperature gradients. It is usually assumed, at least implicitly, that an Ekman process of negative PV generation is the mechanism whereby friction reduces the strength and growth rates of baroclinic systems. Although there is evidence for this mechanism, it is shown that baroclinic generation of PV dominates, producing positive PV anomalies downstream of the low centre, close to developing warm and cold fronts. These PV anomalies are advected by the large-scale warm conveyor belt flow upwards and polewards, fluxed into the troposphere near the warm front, and then advected westwards relative to the system. The result is a thin band of positive PV in the lower troposphere above the surface low centre. This PV is shown to be associated with a positive static stability anomaly, which Rossby edge wave theory suggests reduces the strength of the coupling between the upper- and lower-level PV anomalies, thereby reducing the rate of baroclinic development. This mechanism, which is a result of the baroclinic dynamics in the frontal regions, is in marked contrast with simple barotropic spin-down ideas. Finally we note the implications of these frictionally generated PV anomalies for cyclone forecasting