Retention and application of Skylab experiment experiences to future programs

Problems encountered on Skylab Experiments are listed in order that these experiences and associated recommendations might help to prevent similar problems on future programs. The criteria for selection of the data to be utilized was to identify the problem areas within the Skylab Program which would be of major significance with respect to future programs. Also, the problem had to be unique in that it would help identify to a designer/manufacturer an unforeseen or unanticipated occurrence which could cause failures, delays, or additional cost. Only those unexpected problems that may occur due to the nature of aerospace experiment environmental and operational requirements are included

Infrared scanner Patent

Infrared scanning system for maintaining spacecraft orientation with earth referenc

Analytical results for a Fokker-Planck equation in the small noise limit

We present analytical results for the lowest cumulants of a stochastic process described by a Fokker-Planck equation with nonlinear drift. We show that, in the limit of small fluctuations, the mean, the variance and the covariance of the process can be expressed in compact form with the help of the Lambert W function. As an application, we discuss the interplay of noise and nonlinearity far from equilibrium.Comment: 5 pages, 4 figure

Molecular Clock on a Neutral Network

The number of fixed mutations accumulated in an evolving population often displays a variance that is significantly larger than the mean (the overdispersed molecular clock). By examining a generic evolutionary process on a neutral network of high-fitness genotypes, we establish a formalism for computing all cumulants of the full probability distribution of accumulated mutations in terms of graph properties of the neutral network, and use the formalism to prove overdispersion of the molecular clock. We further show that significant overdispersion arises naturally in evolution when the neutral network is highly sparse, exhibits large global fluctuations in neutrality, and small local fluctuations in neutrality. The results are also relevant for elucidating the topological structure of a neutral network from empirical measurements of the substitution process.Comment: 10 page

Race Redistricting, and the Congressional Black Caucus--Who Needs Em\u27!?: Gauging the Essentiality of African American Congresspersons

In light of the recent controversy surrounding the validity of race conscious redistricting, the practice of creating congressional districts with an African American or Hispanic majority population, an important question arises; are the votes of African American congresspersons even critical to the passage of policy issues salient to the African American populace. This study seeks to prove that the votes of African American congresspersons are crucial to the passage of House policy issues salient to the African American community. To prove this hypothesis this study analyzed the voting cohesion and pivotal voting bloc influence of each Congressional Black Caucus (CBC) member of both the 102nd and 103rd Congress on policy issues deemed salient to the black community per the CBC\u27 Black Agenda . The object is to determine whether the votes of the 102nd and 103rd Caucuses, played an essential role in the passage of policy issues salient to African Americans. Non-CBC Democrat cohesion was also examined pertaining to these issue in order to ascertain the level of support non-CBC Democrats gave in the House passage of the corresponding issues. The finding demonstrate not only are the votes of CBC members necessary, but more African American Congresspersons, who are sensitive to black issues and who are willing to vote cohesively with the CBC, are needed to seriously promote and preserve policy issues of most importance to African Americans

Symmetry Relations for Trajectories of a Brownian Motor

A Brownian Motor is a nanoscale or molecular device that combines the effects of thermal noise, spatial or temporal asymmetry, and directionless input energy to drive directed motion. Because of the input energy, Brownian motors function away from thermodynamic equilibrium and concepts such as linear response theory, fluctuation dissipation relations, and detailed balance do not apply. The {\em generalized} fluctuation-dissipation relation, however, states that even under strongly thermodynamically non-equilibrium conditions the ratio of the probability of a transition to the probability of the time-reverse of that transition is the exponent of the change in the internal energy of the system due to the transition. Here, we derive an extension of the generalized fluctuation dissipation theorem for a Brownian motor for the ratio between the probability for the motor to take a forward step and the probability to take a backward step

Populations of Phaeophyscia leana (Tuck.) Essl. within the Ohio River Basin

Phaeophyscia leana (Tuck.) Essl., an endemic North American lichen species presently known to occur only within the Ohio River basin, is state-endangered in Illinois and a potential candidate for the Federal Endangered Species list. Since it utilizes periodically inundated corticolous substrates associated with river channels, oxbow lakes, and sloughs, this imperiled lichen is sensitive to landuse patterns within river floodplains. Surveys for P. leana were conducted to recensus previously documented populations, thereby assessing their stability, and to identify additional populations within the Ohio River Basin. Watercraft surveys were conducted on the Little Wabash River, from Carmi to New Haven, Illinois, and on the Wabash River from Darwin, Illinois, to the terminus at the Ohio River. Watercraft surveys resulted in the discovery of five new populations of P. leana, two in Illinois and three in Indiana, all of which were located south of Illinois State Route 141. Land-based surveys in Illinois identified new populations within the floodplain formed at the confluence of the Wabash and Ohio Rivers in Gallatin County and within the Black Bottom of Massac County. Nine large oxbow lake communities and backwater slough channels were found to support populations of P. leana within the Gallatin Bottoms which is the population center for P. leana in Illinois. Additions to the Illinois core site list include large populations at Fehrer Lake, Big Lake, and Saline Mines, all within the Gallatin Bottoms floodplain. Watercraft reconnaisance of the Wabash River and Ohio River floodplains (the Big Rivers Region) in Indiana led to the discovery of P. leana populations in Posey, Spencer, Perry, Crawford, and Switzerland County, Indiana, as well as a population in Trimble County, Kentucky. The population located at Vevay, Indiana, in Switzerland County is the closest documented population to the type locality near Cincinnati, Ohio. Land-based surveys conducted in the Hoosier National Forest and the Harrison-Crawford State Forest elucidated the only core site in Indiana, the Mano Point population, near Derby. A population was also discovered in Tennessee at the Hartsville boat launch on the Cumberland River (Old Hickory Lake). Core sites in Tennessee include the Hartsville population as well as populations discovered by Loy R. Phillippe on the Caney Fork River near Hell Bend (downstream from Carthage) and below the Center Hill Dam located on Wolf Island. A total of six core sites were located in this survey and eighty-five positions, where P. leana was observed growing, were recorded with UTM coordinates

Populations of Phaeophyscia leana (Tuck.) Essl. within the Ohio River Basin

Phaeophyscia leana (Tuck.) Essl., an endemic North American lichen species presently known to occur only within the Ohio River basin, is state-endangered in Illinois and a potential candidate for the Federal Endangered Species list. Since it utilizes periodically inundated corticolous substrates associated with river channels, oxbow lakes, and sloughs, this imperiled lichen is sensitive to landuse patterns within river floodplains. Surveys for P. leana were conducted to recensus previously documented populations, thereby assessing their stability, and to identify additional populations within the Ohio River Basin. Watercraft surveys were conducted on the Little Wabash River, from Carmi to New Haven, Illinois, and on the Wabash River from Darwin, Illinois, to the terminus at the Ohio River. Watercraft surveys resulted in the discovery of five new populations of P. leana, two in Illinois and three in Indiana, all of which were located south of Illinois State Route 141. Land-based surveys in Illinois identified new populations within the floodplain formed at the confluence of the Wabash and Ohio Rivers in Gallatin County and within the Black Bottom of Massac County. Nine large oxbow lake communities and backwater slough channels were found to support populations of P. leana within the Gallatin Bottoms which is the population center for P. leana in Illinois. Additions to the Illinois core site list include large populations at Fehrer Lake, Big Lake, and Saline Mines, all within the Gallatin Bottoms floodplain. Watercraft reconnaisance of the Wabash River and Ohio River floodplains (the Big Rivers Region) in Indiana led to the discovery of P. leana populations in Posey, Spencer, Perry, Crawford, and Switzerland County, Indiana, as well as a population in Trimble County, Kentucky. The population located at Vevay, Indiana, in Switzerland County is the closest documented population to the type locality near Cincinnati, Ohio. Land-based surveys conducted in the Hoosier National Forest and the Harrison-Crawford State Forest elucidated the only core site in Indiana, the Mano Point population, near Derby. A population was also discovered in Tennessee at the Hartsville boat launch on the Cumberland River (Old Hickory Lake). Core sites in Tennessee include the Hartsville population as well as populations discovered by Loy R. Phillippe on the Caney Fork River near Hell Bend (downstream from Carthage) and below the Center Hill Dam located on Wolf Island. A total of six core sites were located in this survey and eighty-five positions, where P. leana was observed growing, were recorded with UTM coordinates

Modeling Attitude Variance in Small Unmanned Aerial Systems for Acoustic Signature Simplification Using Experimental Design in a Hardware-in-the-Loop Simulation

The role and use of unmanned aerial systems (UASs) by the Department of Defense has been on the rise over the past decade. The majority of these systems are being utilized in environments where the UAS\u27s acoustic stealth is frequently of greater importance than radio frequency or visual stealth. Additionally, missions involving these types of systems tend to involve dynamic mission planning requirements rather than preplanned routing. Therefore, an acoustic model capable of providing real-time probability of detection information is desired. However, with present-day technology and existing acoustic models, real-time calculation of the complete acoustic signature for a small UAS (SUAS) is not feasible. This research demonstrates that the acoustic signature of the Sig Rascal 110 SUAS can be reduced by greater than 99.3% when a listener point of interest is directly below the aircraft using a methodology to model SUAS attitude variance to reduce the portion of the acoustic signature of concern. This model is developed using designed experiments in a hardware-in-the-loop simulation and uses aircraft flight parameters as factors determining attitude variance