Selected experiments in laminar flow: An annotated bibliography

Since the 1930s, there have been attempts to reduce drag on airplanes by delaying laminar to turbulent boundary layer transition. Experiments conducted during the 1940's, while successful in delaying transition, were discouraging because of the careful surface preparation necessary to meet roughness and waviness requirements. The resulting lull in research lasted nearly 30 years. By the late 1970s, airframe construction techniques had advanced sufficiently that the high surface quality required for natural laminar flow (NLF) and laminar flow control (LFC) appeared possible on production aircraft. As a result, NLF and LFC research became widespread. This report is an overview of that research. The experiments summarized herein were selected for their applicability to small transonic aircraft. Both flight and wind tunnel tests are included. The description of each experiment is followed by corresponding references. Part One summarizes NLF experiments; Part Two deals with LFC and hybrid laminar flow control (HLFC) experiments

The History, Present Condition, and Future of the Molluscan Fisheries of North and Central America and Europe: Volume 2, Pacific Coast and Supplemental Topics

Over 100 molluscan species are landed in Mexico. About 30% are harvested on the Pacific coast and 70% on the Atlantic coast. Clams, scallops, and squid predominate on the Pacific coast (abalone, limpets, and mussels are landed there exclusively). Conchs and oysters predominate on the Atlantic coast. In 1988, some 95,000 metric tons (t) of mollusks were landed, with a value of $33 million. Mollusks were used extensively in prehispanic Mexico as food, tools, and jewelry. Their use as food and jewelry continues. Except in the States of Baja California and Baja California Sur, where abalone, clams, and scallops provide fishermen with year-round employment, mollusk fishing is done part time. On both the Pacific and Atlantic coasts, many fishermen are nomads, harvesting mollusks wherever they find abundant stocks. Upon finding such beds, they build camps, begin harvesting, and continue until the mollusks become so scarce that it no longer pays to continue. They then look for productive beds in other areas and rebuild their camps. Fishermen harvest abalones, mussels, scallops, and clams by free-diving and using scuba and hooka. Landings of clams and cockles have been growing, and 22,000 t were landed in 1988. Fishermen harvest intertidal clams by hand at wading depths, finding them with their feet. In waters up to 5 m, they harvest them by free-diving. In deeper water, they use scuba and hooka. Many species of gastropods have commercial importance on both coasts. All species with a large detachable muscle are sold as scallops. On the Pacific coast, hatchery culture of oysters prevails. Oyster culture in Atlantic coast lagoons began in the 1950's, when beds were enhanced by spreading shells as cultch for spat. (PDF file contains 228 pages.

The History, Present Condition, and Future of the Molluscan Fisheries of North and Central American and Europe: Volume 1, Atlantic and Gulf Coasts

This three-volume monograph represents the first major attempt in over a century to provide, on regional bases, broad surveys of the history, present condition, and future of the important shellfisheries of North and Central America and Europe. It was about 100 years ago that Ernest Ingersoll wrote extensively about several molluscan fisheries of North America (1881, 1887) and about 100 years ago that Bashford Dean wrote comprehensively about methods of oyster culture in Europe (1893). Since those were published, several reports, books, and pamphlets have been written about the biology and management of individual species or groups ofclosely related mollusk species (Galtsoff, 1964; Korringa, 1976 a, b, c; Lutz, 1980; Manzi and Castagna, 1989; Shumway, 1991). However, nothing has been written during the past century that is comparable to the approach used by Ingersoll in describing the molluscan fisheries as they existed in his day in North America or, for that matter, in Europe. (PDF file contains 224 pages.

The History, Present Condition, and Future of the Molluscan Fisheries of North and Central America and Europe: Volume 3, Europe

(PDF file contains 248 pages.

Development and evaluation of a prototype in-flight instrument flight rules (IFR) procedures trainer

An in-flight instrument flight rules (IFR) procedures trainer capable of providing simulated indications of instrument flight in a typical general aviation aircraft independent of ground based navigation aids was developed. The IFR navaid related instruments and circuits from an ATC 610J table top simulator were installed in a Cessna 172 aircraft and connected to its electrical power and pitot static systems. The benefits expected from this hybridization concept include increased safety by reducing the number of general aviation aircraft conducting IFR training flights in congested terminal areas, and reduced fuel use and instruction costs by lessening the need to fly to and from navaid equipped airports and by increased efficiency of the required in-flight training. Technical feasibility was demonstrated and the operational feasibility of the concept was evaluated. Results indicated that the in-flight simulator is an effective training device for teaching IFR procedural skills

Assessment of Public Sector Service Quality: Gauging Experiences and Perceptions of Racial Profiling

The absence of a culturally competent public sector workforce has led to increased public scrutiny and heightened levels of distrust. In the field of public safety, this is particularly important due to the sensitive nature of the task performed and the historically strained relationships that exist between racial minorities and law enforcement. Using national survey data to gauge the prevalence of citizen’s experiences and perceptions of racial profiling, this research reveals significant discrepancies amongst minorities and their white counterparts. In response, this research encourages public officials and agencies to eliminate inconsistencies in their interactions with the citizenry as a whole. Furthermore, it appeals to public administration scholars to address these issues in their classrooms as well as in their future research. Combined, these efforts can bring awareness and help mitigate the disparate delivery and administering of public-sector services

Models of Disordered Media and Predictions of Associated Hydraulic Conductivity

In the late 20th century there was a spill of Technetium in eastern Washington State at the US Department of Energy Hanford site. Resulting contamination of water supplies would raise serious health issues for local residents. Therefore, the ability to predict how these contaminants move through the soil is of great interest. The main contribution to contaminant transport arises from being carried along by flowing water. An important control on the movement of the water through the medium is the hydraulic conductivity, K, which defines the ease of water flow for a given pressure difference (analogous to the electrical conductivity). The overall goal of research in this area is to develop a technique which accurately predicts the hydraulic conductivity as well as its distribution, both in the horizontal and the vertical directions, for media representative of the Hanford subsurface. The Hanford subsurface is a disordered sequence of ice-age flood deposits. It is known that concepts from percolation theory are well-suited to addressing transport problems in disordered media. The objective of this thesis was two-fold: (a) to implement techniques using critical path analysis from percolation theory for calculating the distribution of K values for soils with known characteristics, (b) to apply this technique to 53 sets of particle-size data and water retention characteristics taken from soils which represent the area in which the Technetium spill occurred. The research performed should be applicable to other contaminated sites under DOE supervision as well as being relevant for agriculture, climate models, mining and elsewhere

The Effect of the Spray and Stretch Technique on the Silent Period Duration of the Masseter Muscle

The purpose of this study was to evaluate the effectiveness of Fluori-Methane vapocoolant spray, as used in the spray and stretch technique, on decreasing a prolonged silent period duration in the masseter muscle. Ten subjects were selected, all of whom were identified as having masseter muscle dysfunction and/or spasm. The population consisted of two males and eight females, whose ages ranged from 24-58. The silent period duration of the masseter was measured following elicitation of the jaw-jerk reflex. Five readings were taken and the mean silent period duration was calculated. All means longer than 35 milliseconds were considered prolonged. An EDX 1000 electromyograph and Beckman standard size silver surface electrodes were used in recording the data. The amount of mandibular depression available was also measured. Once these measurements were completed, each subject was treated using Fluori-Methane vapocoolant spray, as used in the spray and stretch technique. The silent period duration and amount of mandibular depression were then remeasured in the same manner as was done prior to treatment. The pre and post-treatment data was then analyzed using the t-test for related measures. The effectiveness of Fluroi-Methane on decreasing a prolonged masseter silent period duration was significant at the .005 level of significance for directional tests. The effectiveness of Fluori-Methane on increasing mandibular opening was significant at the .0005 level of significance for directional tests. These results are consistent with the expected outcome and reinforce previous studies that have found Fluori-Methane to be effective in reducing muscle spasms. This study also provides a means for objectively measuring the progress of a patient with masseter spasms who is undergoing physical therapy management

Sowing Seeds of Tradition! Applying Traditional Family Values and Adaptive Reuse to Resurrect a Community.

There are problems in every community, including South Memphis, Tennessee. Issues that need to be addressed include teen pregnancies, school drop-outs, crime, childhood obesity, and lack of parental guidance. Traditional family characteristics such as spiritual life, caring and appreciation, commitment, flexibilty and openness to change were once guiding forces that have been lost in our current culture. The response has been to provide community centers, which have often failed because they do not teach the basic skills necessary for a productive life. One solution is to convert the Turner Dairy Warehouse on South Bellevue into a facility that will provide education, enrichment, and encouragement. The Family Educational Exchange & Development Center (F.E.E.D) will be an educational facility instilling family values, teaching integrated life skills, and giving back to the community. The skills taught will include horticulture, home-economics, parenting, and general education. This facility will bring life to a dying community

Comparison of acoustic travel-time measurement of solar meridional circulation from SDO/HMI and SOHO/MDI

Time-distance helioseismology is one of the primary tools for studying the solar meridional circulation. However, travel-time measurements of the subsurface meridional flow suffer from a variety of systematic errors, such as a center-to-limb variation and an offset due to the P-angle uncertainty of solar images. Here we apply the time-distance technique to contemporaneous medium-degree Dopplergrams produced by SOHO/MDI and SDO/HMI to obtain the travel-time difference caused by meridional circulation throughout the solar convection zone. The P-angle offset in MDI images is measured by cross-correlating MDI and HMI images. The travel-time measurements in the south-north and east-west directions are averaged over the same observation period for the two data sets and then compared to examine the consistency of MDI and HMI travel times after correcting the systematic errors. The offsets in the south-north travel-time difference from MDI data induced by the P-angle error gradually diminish with increasing travel distance. However, these offsets become noisy for travel distances corresponding to waves that reach the base of the convection zone. This suggests that a careful treatment of the P-angle problem is required when studying a deep meridional flow. After correcting the P-angle and the removal of the center-to-limb effect, the travel-time measurements from MDI and HMI are consistent within the error bars for meridional circulation covering the entire convection zone. The fluctuations observed in both data sets are highly correlated and thus indicate their solar origin rather than an instrumental origin. Although our results demonstrate that the ad hoc correction is capable of reducing the wide discrepancy in the travel-time measurements from MDI and HMI, we cannot exclude the possibility that there exist other systematic effects acting on the two data sets in the same way.Comment: accepted for publication in A&