A Proposed Interpretation of Transitional and Turbulent Energy Flow Processes

This paper discusses the consequence of a continuum analysis of turbulence using the Reynolds convention, on the cascade of energy to internal thermal energy. It is observed that there are two distinct dissipative paths or traps that the energy follows, neither of which involves vorticity. It is observed that the so-called Reynolds\u27 Stresses are not involved in these irreversible dissipative paths, but are in the reversible bridge between the mean and fluctuating flows. An effort is made to generate a consistent physical interpretation of all of the terms in the equations used rather than selecting isolated terms for explanation. Some suggestions are made for modeling the dissipative terms and an appendix is included to illustrate how information can be lost in an integration process that results in erroneously ascribing dissipative roles to perfectly reversible terms and equations

Impact of Water and Soils Having High Source-Sink Potentials on Water and Salinity Management Under Irrigation in the Upper Colorado River Basin

Water management in irrigation projects is one potential method for reducing downstream salinity in the Colorado River. An important contribution can be made to developing more effective irrigation water management practices for water conservation and salinity control through identification and better understanding of the soil and water interactions that result in soils behaving as salt sources or as salt sinks. The interactions identified in this study were examined to determine the effects of various management alternatives on the quality and quantity of salt in subsurface return flow from irrigation projects. A soil solution chemistry model was developed to describe the soil-irrigation water interactions. The model includes the effect of cation exchange capacity. The model was calibrated and checked with data obtained from lysimeters. A water management model that contained a soil solution chemistry component was calibrated for the Ashley Valley of Utah and was used to determine the sensitivity of stream flows and salinity to irrigation water management alternatives. The source-sink behavior of soils was found to depent on water quality, residual soil salinity, and water management practices. The key relationships are described. In applying these relationships, site specific conditions must be examined to determine the effectiveness of proposed irrigation management changes that are expected to affect downstream salinity

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transpot project-demonstration act system definition

The 1985 ACT airplane is the Final Active Controls Technology (ACT) Airplane with the addition of three-axis fly by wire. Thus it retains all the efficiency features of the full ACT system plus the weight and cost savings accruing from deletion of the mechanical control system. The control system implements the full IAAC spectrum of active controls except flutter-mode control, judged essentially nonbeneficial, and incorporates new control surfaces called flaperons to make the most of wing-load alleviation. This redundant electronic system is conservatively designed to preserve the extreme reliability required of crucial short-period pitch augmentation, which provides more than half of the fuel savings

Clinical Effects of Electromagnetic Stimulation as an Adjunct to Periodontal Therapy

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141604/1/jper0046.pd

Integrated Application of Active Controls (IAAC) technology to an advanced subsonic transport project: Current and advanced act control system definition study. Volume 2: Appendices

The current status of the Active Controls Technology (ACT) for the advanced subsonic transport project is investigated through analysis of the systems technical data. Control systems technologies under examination include computerized reliability analysis, pitch axis fly by wire actuator, flaperon actuation system design trade study, control law synthesis and analysis, flutter mode control and gust load alleviation analysis, and implementation of alternative ACT systems. Extensive analysis of the computer techniques involved in each system is included

Optimizing crop production through control of water and salinity levels in the soil

Sizable investments have been made and continue to be made throughout the world to develop irrigation potentials. Recent food shortages have heightened the concern for obtaining greater returns to irrigation through improved water management and use. A knowledge of how plant growth cycles relate to moisture and salinity levels in the root zone is prerequisite to developing practical ways of maintaining optimum conditions for maximum production per unit of water concerned. This research further defines the role of irrigation timing and salinity management on crop production, and proposes practical techniques for predicting the crop response to management measures. Some of the advantages and special features of the research program outlined by the report are listed as follows: 1. The experimental design is unique in that a sprinkler line is used as a single source of water. This approach provides large volumes of yield data as influenced by water supplies available to the crop. These data will provide information on the following: a. Accurate evaluation of the basic water requirements of crops. b. The optimal sequencing of deficits during crop growth stages. c. The establishment of yield versus evapotranspiration relationships over the entire range of wter supply from rainfall (dryland) to over-irrigation. d. An evaluation of soil water holding capacities in terms of its contributions to the water needs of the crop. This information provides guidance on how to best utilize the root system of a given crop type as a water gathering tool in terms of time during the growing season. For example, planting date, plant spacing, and fertilizer practices will be influenced by this information. 2. The experimental layout is versatile in that it lends itself to a study of the effects on plant growth of input parameters other than water, such as fertility levels and plant spacing. 3. The design can be readily adapted to accommodate several varieties and/or species in the same experiment. 4. The research results are practical and generally applicable to a wide range of crop, climate, soil, and water supply (non site specific and site specific) conditions. 5. The research provides a clear demonstration (both visual and quantitative) of the beneficial effects of proper management practices on crop production. 6. The research deals with both domestic and international water problems involving crop production, namely, the influence of available soil measure and soil salinity on plant yields. 7. The research techniques are readily adaptable to application in developing countries. a. A sprinkler system for irrigation is not necessary though desireable. b. The research procedures are simple, inexpensive, easy to perform, and yet provide much information. 8. The research involves the join efforts of several institutions and utilizes highly experienced research principal investigators who have a proven record of effectively working together as an integrated team. 9. The validity of the research approach and the viability of the results have been demonstrated by current research. The main tasks remaining are to broaden the crop base and to test and demonstrate the applicability of the results to other areas throughout the world

The Effects of Cleaning on the Kinetics of in vitro Metal Release from Dental Casting Alloys

The kinetics of the release of elements from six dental casting alloys into cell-culture medium was assessed by means of atomic absorption spectroscopy. Alloys were evaluated in the polished and polished-cleaned conditions so that the effects of cleaning could be determined. Auger scanning microscopy was used for analysis of the surfaces of selected alloys before and after exposure to the cell-culture medium. Release patterns for each element were characterized by the shape of the dissolution us. time curve, concentration of the element at 12 h as a percentage of the 72-hour concentration, and the relative slope of the curve from 48 to 72 h. Three patterns of release were observed for elements in these alloys. Type I patterns had logarithmic shapes with relatively large 12-hour concentrations and low 48-72-hour slopes. Type II patterns had logarithmic shapes but with moderate 12-hour concentrations and 48-72-hour slopes. Type III patterns were polynomial in shape, had relatively low 12-hour concentrations, and had large 48-72-hour slopes. Cleaning did not change the pattern of release but did generally significantly decrease the quantities of elements released (p = 0.05). The type of dissolution vs. time curve appeared to be dependent upon the element and the composition of the alloy. When cleaning reduced dissolution, surface analyses showed that the cleaning process increased the abundance of elements such as Au and Pd and reduced the abundance of Ag and Cu. Elements which were released from the alloys were more abundant on the surface than in the bulk in both polished and polished-cleaned conditions. Auger analyses of alloy surfaces after exposure to medium showed the presence of organic films up to 50 nm thick. This study demonstrated the importance of consideration of the cleaning method and kinetic release pattern when in vitro tests which assess the cytotoxicities of these alloys are planned.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67010/2/10.1177_00220345920710071101.pd