Device for suppressing sound and heat produced by high-velocity exhaust jets Patent

Device for adding water to high velocity exhaust jets to reduce velocity, noise, and temperatur

Acceptance testing lunar and planetary vehicles /a concept/

Concepts of acceptance testing lunar and planetary vehicle

Predicted acoustical performance of the S-IC SOUND suppressor

Scale model acoustical tests for predicting performance of S-IC static test facility sound suppresso

The Victoria Falls, a species boundary for the Zambezi Parrotfish, Cyphomyrus discorhynchus (Peters, 1852), and the resurrection of Cyphomyrus cubangoensis (Pellegrin, 1936) (Mormyridae: Teleostei)

Cyphomyrus discorhynchus occurs in the Zambezi River and in the linked systems of the Kwando and the Okavango. We collected specimens from both above and below the Victoria Falls and recorded Electric Organ Discharges. We found a marked degree of anatomical differentiation among the specimens from the Zambezi delta to the Victoria Falls that represents a subspecific, geographical cline, reflecting the great length (1400 km) and high ecological diversity of that river section (Lower and Middle Zambezi). We confirm that the populations above the Falls (i.e. Upper Zambezi, Kwando and Okavango) are differentiated from those below, possessing fewer dorsal fin rays (a median of 30–31 rather than 33–34). The waveforms of the electric organ discharge pulses have four phases and show geographic variation but were briefer for specimens from below the Falls. We resurrect Cyphomyrus cubangoensis (Pellegrin, 1936) for the Upper Zambezi/Kwando/Okavango system

Research on output feedback control

In designing fixed order compensators, an output feedback formulation has been adopted by suitably augmenting the system description to include the compensator states. However, the minimization of the performance index over the range of possible compensator descriptions was impeded due to the nonuniqueness of the compensator transfer function. A controller canonical form of the compensator was chosen to reduce the number of free parameters to its minimal number in the optimization. In the MIMO case, the controller form requires a prespecified set of ascending controllability indices. This constraint on the compensator structure is rather innocuous in relation to the increase in convergence rate of the optimization. Moreover, the controller form is easily relatable to a unique controller transfer function description. This structure of the compensator does not require penalizing the compensator states for a nonzero or coupled solution, a problem that occurs when following a standard output feedback synthesis formulation

Consequences of Postnatally Elevated Insulin-Like Growth Factor-II in Transgenic Mice: Endocrine Changes and Effects on Body and Organ Growth.

Insulin-like growth factor-II (IGF-II) is an important regulator of embryonic growth and differentiation, but its function in postnatal life is unclear. To address this point, we generated transgenic mice harboring fusion genes in which a human IGF-II complementary DNA is placed under the transcriptional control of the rat phosphoenolpyruvate carboxykinase promoter. Transgene-specific messenger RNA was detected in liver, kidney, and several parts of the gut. Serum IGF-II levels in transgenic mice were 2-3 times higher than those in controls and increased after starvation. Circulating IGF-I correlated negatively and IGF-binding protein-2 (IGFBP-2) positively with IGF-II levels, suggesting that IGF-I is displaced from IGFBPs by IGF-II and that IGFII is a major regulator of IGFBP-2. Serum levels of IGFBP-3 and IGFBP-4 tended to be higher in phosphoenolpyruvate carboxykinase- IGF-II transgenic mice than in controls, as evaluated by ligand blot analysis. Starvation reduced serum IGF-I, but increased IGFBP-2 in transgenic mice more markedly than in controls. Fasting insulin levels were significantly reduced in transgenic mice, whereas glucose levels were not influenced by elevated IGF-II. The body growth of 4- and 12- week-old mice was not significantly influenced by elevated IGF-II, but transgenic mice displayed increased kidney and testis weight at the age of 4 weeks, and increased adrenal weight at the age of 12 weeks. Our results demonstrate that elevated IGF-II in postnatal life has multiple endocrine consequences and subtle time-specific effects on organ growth

Negative differential conductance induced by spin-charge separation

Spin-charge states of correlated electrons in a one-dimensional quantum dot attached to interacting leads are studied in the non-linear transport regime. With non-symmetric tunnel barriers, regions of negative differential conductance induced by spin-charge separation are found. They are due to a correlation-induced trapping of higher-spin states without magnetic field, and associated with a strong increase in the fluctuations of the electron spin.Comment: REVTEX, 4 pages including 3 figures; Accepted for publication on Physical Review Letter

IUPUI Image Collection: A Usability Survey

Purpose: To measure functionality, content, and awareness of an online digital image collection by observing participants in a controlled search for a specific image and evaluating their responses to questions with the objective of improving the site. Methodology: Participants were recruited from among faculty, staff, and students based on interests stated in online profiles or indicated by type of professional work or academic major. Participants were timed while searching for a target photo and interviewed afterward about their search experience and their use of digital images. Findings: Most potential users are not aware of the IUPUI Image Collection and have some difficulty locating it, but when introduced to it find the site attractive and navigable and its content interesting and useful for research, instruction, publication, or class work. Research limitations: There were only 5,100 images uploaded to the collection at the time of the study. The participant group was limited to 70. Practical implications: User data and suggestions help the Archives staff work with CONTENTdm™ to make improvements to the site’s function and metadata; choose photos to scan for the collection; and develop site-marketing plans. Originality/value: This study provides quantitative measurements of user habits and concerns. Observation, sometimes rejected as an obtrusive methodology, is shown here as an important tool to evaluate human-computer interaction for improved understanding of user perspectives on navigability and functionality

Spin and rotational symmetries in unrestricted Hartree Fock states of quantum dots

Ground state energies are obtained using the unrestricted Hartree Fock method for up to four interacting electrons parabolically confined in a quantum dot subject to a magnetic field. Restoring spin and rotational symmetries we recover Hund first rule. With increasing magnetic field, crossovers between ground states with different quantum numbers are found for fixed electron number that are not reproduced by the unrestricted Hartree Fock approximation. These are consistent with the ones obtained with more refined techniques. We confirm the presence of a spin blockade due to a spin mismatch in the ground states of three and four electrons.Comment: 16 Pages, 2 figures, accepted for publication on New Journal of Physic

Localized low-frequency Neumann modes in 2d-systems with rough boundaries

We compute the relative localization volumes of the vibrational eigenmodes in two-dimensional systems with a regular body but irregular boundaries under Dirichlet and under Neumann boundary conditions. We find that localized states are rare under Dirichlet boundary conditions but very common in the Neumann case. In order to explain this difference, we utilize the fact that under Neumann conditions the integral of the amplitudes, carried out over the whole system area is zero. We discuss, how this condition leads to many localized states in the low-frequency regime and show by numerical simulations, how the number of the localized states and their localization volumes vary with the boundary roughness.Comment: 7 pages, 4 figure