Multivariate Design of Experiments for Engineering Dimensional Analysis

We consider the design of dimensional analysis experiments when there is more than a single response. We first give a brief overview of dimensional analysis experiments and the dimensional analysis (DA) procedure. The validity of the DA method for univariate responses was established by the Buckingham $\Pi$-Theorem in the early 20th century. We extend the theorem to the multivariate case, develop basic criteria for multivariate design of DA and give guidelines for design construction. Finally, we illustrate the construction of designs for DA experiments for an example involving the design of a heat exchanger

Fatigue testing a plurality of test specimens and method

Described is a fatigue testing apparatus for simultaneously subjecting a plurality of material test specimens to cyclical tension loading to determine the fatigue strength of the material. The fatigue testing apparatus includes a pulling head having cylinders defined therein which carry reciprocating pistons. The reciprocation of the pistons is determined by cyclical supplies of pressurized fluid to the cylinders. Piston rods extend from the pistons through the pulling head and are attachable to one end of the test specimens, the other end of the test specimens being attachable to a fixed base, causing test specimens attached between the piston rods and the base to be subjected to cyclical tension loading. Because all the cylinders share a common pressurized fluid supply, the breaking of a test specimen does not substantially affect the pressure of the fluid supplied to the other cylinders nor the tension applied to the other test specimens

What to Consider When Evaluating Staff Development

District leaders must look deeper than students\u27 achievement scores and use a multifacted approach to assess the quality of their staff development efforts

A guide to nestling development and aging in altricial passerines

Nestling growth and development studies have been a topic of interest for a greater part of the last century (Sutton 1935, Walkinshaw 1948) and continue to be of interest today. This is not surprising since studies on nestling growth can provide a wealth of biological information that has larger implications for avian management and conservation. Despite this history of studying nestling development, basic information is still limited or absent for many species. Many questions remain unanswered, and contradictory conclusions are often found in the literature (Starck and Ricklefs 1998a). Therefore, much information on aging and development can still be gained from studying the development patterns of similar species and from comparative studies, across avian orders (Minea et al. 1982, Saunders and Hansen 1989, Carsson and Hörnfeldt 1993). Additionally, nestling growth studies can yield insight into the effects of different nesting strategies on productivity (O’Connor 1978), as well as the impacts of parental effort and environmental variables on fitness (Ross 1980, Ricklefs and Peters 1981, Magrath 1991). Since low reproductive success may play a significant role in the declines of many North American passerines (Sherry and Holmes 1992, Ballard et al. 2003), a better understanding of the factors that influence reproductive success is a vital component of avian conservation (Martin 1992). Data on nestling aging can be used to improve nest survival estimates (Dinsmore 2002, Nur et al. 2004), providing information that can be used to more precisely age nests (Pinkowski 1975, Podlesack and Blem 2002), (Jones and Geupel 2007). Indeed, the relatively short time period young spend developing in the nest is a critical part of a bird’s life cycle and a nestling’s developmental path can affect its survival to independence, its survival as an adult, and its future reproductive success

Agricultural Biotechnology as an Intangible Asset: Incentives for Transnational Vertical Integration in Agribusiness

Exact date of working paper unknown.An emerging global phenomenon is the application of biotechnology to food and agricultural production. How individual firms will relate to biotechnological advances and the decisions made regarding the commercialization of biotechnology will influence the structure of the industrial landscape in global markets and international trade. The scope of biotechnology in the United States and Europe and the economic incentives for transnational vertical integration of biotechnological products or processes is examined. An economic model is used to assess the nature of incentives for the transnational vertical integration of biotechnology. The analysis argues that rights to commercial biotechnology products or processes are intangible assets which may provide incentives for vertical foreign direct investment by the firms holding such rights. The transnational character of intellectual property as an intangible asset is explored briefly. Implications are drawn from the analysis concerning transnational vertical integration of biotechnology

Agricultural Contribution of Nitrate-N to the Des Moines River: 1945 vs. 1980

Recently, intensive water quality monitoring has demonstrated the presence of nitrate (N03-N) in surface and groundwater throughout the Midwestern U.S. (Hallberg, 1989)

Making heads or tails of phospholipids in mitochondria

Mitochondria are dynamic organelles whose functional integrity requires a coordinated supply of proteins and phospholipids. Defined functions of specific phospholipids, like the mitochondrial signature lipid cardiolipin, are emerging in diverse processes, ranging from protein biogenesis and energy production to membrane fusion and apoptosis. The accumulation of phospholipids within mitochondria depends on interorganellar lipid transport between the endoplasmic reticulum (ER) and mitochondria as well as intramitochondrial lipid trafficking. The discovery of proteins that regulate mitochondrial membrane lipid composition and of a multiprotein complex tethering ER to mitochondrial membranes has unveiled novel mechanisms of mitochondrial membrane biogenesis

Short-term studies underestimate 30-generation changes in a butterfly metapopulation

Most studies of rare and endangered species are based on work carried out within one generation, or over one to a few generations of the study organism. We report the results of a study that spans 30 generations (years) of the entire natural range of a butterfly race that is endemic to 35 km2 of north Wales, UK. Short-term studies (surveys in single years and dynamics over 4 years) of this system led to the prediction that the regional distribution would be quite stable, and that colonization and extinction dynamics would be relatively unimportant. However, a longer-term study revealed unexpectedly high levels of population turnover (local extinction and colonization), affecting 18 out of the 20 patches that were occupied at any time during the period. Modelling the system (using the 'incidence function model' (IFM) for metapopulations) also showed higher levels of colonization and extinction with increasing duration of the study. The longer-term dynamics observed in this system can be compared, at a metapopulation level, with the increased levels of variation observed with increasing time that have been observed in single populations. Long-term changes may arise from local changes in the environment that make individual patches more or less suitable for the butterfly, or from unusual colonization or extinction events that take metapopulations into alternative states. One implication is that metapopulation and population viability analyses based on studies that cover only a few animal or plant generations may underestimate extinction threats

Spatial Description and Analysis of Grasshopper Abundances in Colorado Rangeland

Although rangeland grasshopper populations have been studied for more than 120 years, little is known of the spatial patterns in grasshopper numbers between outbreak cycles. This information is necessary to understand how grasshopper outbreaks develop and to correctly design research, monitoring, and modeling projects. We used exploratory data analysis and geostatistics to identify the spatial patterns in grasshopper numbers for 1993 through 1997 in Colorado. The same family of models (spherical) provided the best fit to the sample data for all years, which implies that similar processes influenced grasshopper densities over these years. The parameters of the models differed among years, however, which suggest that the scale of spatial patterning changed over time. Since Colorado grasshopper densities were patterned at scales larger than those reported for other areas of the Great Plains, our results suggest that survey methods for Colorado are not adequate to identify small-scale “hot spots” of high grasshopper numbers, inhibiting prediction of potential outbreak foci in this region

Spatial Description and Analysis of Grasshopper Abundances in Colorado Rangeland

Although rangeland grasshopper populations have been studied for more than 120 years, little is known of the spatial patterns in grasshopper numbers between outbreak cycles. This information is necessary to understand how grasshopper outbreaks develop and to correctly design research, monitoring, and modeling projects. We used exploratory data analysis and geostatistics to identify the spatial patterns in grasshopper numbers for 1993 through 1997 in Colorado. The same family of models (spherical) provided the best fit to the sample data for all years, which implies that similar processes influenced grasshopper densities over these years. The parameters of the models differed among years, however, which suggest that the scale of spatial patterning changed over time. Since Colorado grasshopper densities were patterned at scales larger than those reported for other areas of the Great Plains, our results suggest that survey methods for Colorado are not adequate to identify small-scale “hot spots” of high grasshopper numbers, inhibiting prediction of potential outbreak foci in this region