An investigation of volcanic gases and dust (aerosols) in the stratosphere

There are no author-identified significant results in this report

Calorimetry, activity, and micro-FTIR analysis of CO chemisorption, titration, and oxidation on supported Pt

The value of in situ analysis on CO chemisorption, titration and oxidation over supported Pt catalysts using calorimetry, catalytic and micro-FTIR methods is illustrated using silica- and titania-supported samples. Isothermal CO-O and O2-CO titrations have not been widely used on metal surfaces and may be complicated if some oxide supports are reduced by CO titrant. However, they can illuminate the kinetics of CO oxidation on metal/oxide catalysts since during such titrations all O and CO coverages are scanned as a function of time. There are clear advantages in following the rates of the catalyzed CO oxidation via calorimetry and gc-ms simultaneously. At lower temperatures the evidence they provide is complementary. CO oxidation and its catalysis of CO oxidation have been extensively studied with hysteresis and oscillations apparent, and the present results suggest the benefits of a combined approach. Silica support porosity may be important in defining activity-temperature hysteresis. FTIR microspectroscopy reveals the chemical heterogeneity of the catalytic surfaces used; it is interesting that the evidence with regard to the dominant CO surface species and their reactivities with regard to surface oxygen for present oxide-supported Pt are different from those seen on graphite-supported Pt

On the design of an energy-efficient low-latency integrated protocol for distributed mobile sensor networks

Self organizing, wireless sensors networks are an emergent and challenging technology that is attracting large attention in the sensing and monitoring community. Impressive progress has been done in recent years even if we need to assume that an optimal protocol for every kind of sensor network applications can not exist. As a result it is necessary to optimize the protocol for certain scenarios. In many applications for instance latency is a crucial factor in addition to energy consumption. MERLIN performs its best in such WSNs where there is the need to reduce the latency while ensuring that energy consumption is kept to a minimum. By means of that, the low latency characteristic of MERLIN can be used as a trade off to extend node lifetimes. The performance in terms of energy consumption and latency is optimized by acting on the slot length. MERLIN is designed specifically to integrate routing, MAC and localization protocols together. Furthermore it can support data queries which is a typical application for WSNs. The MERLIN protocol eliminates the necessity to have any explicit handshake mechanism among nodes. Furthermore, the reliability is improved using multiple path message propagation in combination with an overhearing mechanism. The protocol divides the network into subsets where nodes are grouped in time zones. As a result MERLIN also shows a good scalability by utilizing an appropriate scheduling mechanism in combination with a contention period

Report of the panel on volcanology, section 4

Two primary goals are identified as focal to NASA's research efforts in volcanology during the 1990s: to understand the eruption of lavas, gases, and aerosols from volcanoes, the dispersal of these materials on the Earth's surface and through the atmosphere, and the effects of these eruptions on the climate and environment; and to understand the physical processes that lead to the initiation of volcanic activity, that influence the styles of volcanic eruptions, and that dictate the morphology and evolution of volcanic landforms. Strategy and data requirements as well as research efforts are discussed

Ichthyofaunal Assemblages in Three Approximate but Ecologically Diverse Streams in Clark County, Arkansas

Three tributaries to the Ouachita River in eastern Clark County, Arkansas, empty into the river within a collective distance of about 9 km. The streams drain basins derived from the Wilcox formation, partially overlain by terrace and alluvial deposits. Despite their proximity, the streams are very different: L\u27Eau Frais has a gravel substrate and was recognized by the French as a cool water stream, Tupelo Creek is a bottomland stream from which numerous Water Tupelo (Nyssa aquatica) emerge, and Saline Bayou was named due to its marked salinity. We studied the assemblages of fishes in these 3 very different drainages to evaluate the occurrence of species and the degree of similarity of the ichthyofaunas. L\u27Eau Frais differed from the other streams in a greater occurrence of lampreys (Petromyzontidae), including a disjunct population of Lampetra appendix, and suckers (Catostomidae), including the relatively uncommon Blacktail Redhorse (Moxostoma poecilurum). Tupelo Creek had an assemblage of species characteristic of a bottomland stream, and Saline Bayou had the least diverse fish fauna

A Home Device for Vestibular Stimulation

The goal of this project, which was presented to the team by Kevin Maher (President of Advanced Therapeutic devices), was to develop a product prototype for safe, vestibular stimulation for children with developmental disabilities. Vestibular stimulation is a form of therapy that increases muscle coordination. It works by stimulating the canals and sacs within the inner ear that detect accelerations. The project targeted children from ages two to seven years old, under 48 inches tall, and less than 100 lbs. The production device also sought to differ from stimulation devices found in hospitals in a few respects: it would cost under $5000, reside in a patient’s home, be hand-powered, and be controlled by an average person. The final device needed to support a 200 lb. load at the edge of the structure and adjust for the center of gravities for the range of children. After sessions of brainstorming, the team produced three workable layouts, only one was adequate. The final setup had a structure of ¼ in. aluminum structural pipe similar to a football field goal. This structure mounted on a single bearing housing and steel shaft. The final design had two bars to mount weights in order to adjust the center of gravity. The prototype, however, used a swinging bar, lock, and a sliding weight. The final prototype had an adjustable footrest and a five-point restraint harness. The final cost and weight was$1700 and no more than 500 lb. The design met all of the requirements and had adequate safety for any child’s needs, but the team thought the design needed significant changes before it became a final product