The Subcolonization and Buildup of \u3ci\u3eTetrastichus Julis,\u3c/i\u3e (Hymenoptera: Eulophidae) a Larval Parasitoid of the Cereal Leaf Beetle, (Coleoptera: Chrysomelidae) in the Lower Peninsula of Michigan

Following initial establishment of the parasitoid, Tetrastichus julis (Walker), at a carefully managed field nursery, releases of parasitized Oulema melanopus larvae were made by Michigan county agents at preselected sites throughout the lower peninsula during 1970-74. A follow-up recovery program during 1971-75 revealed continued dispersion and population increase for T. julis. An independent census verified the increasing rates of parasitism

Creep of plasma sprayed zirconia

Specimens of plasma-sprayed zirconia thermal barrier coatings with three different porosities and different initial particle sizes were deformed in compression at initial loads of 1000, 2000, and 3500 psi and temperatures of 1100 C, 1250 C, and 1400 C. The coatings were stabilized with lime, magnesia, and two different concentrations of yttria. Creep began as soon as the load was applied and continued at a constantly decreasing rate until the load was removed. Temperature and stabilization had a pronounced effect on creep rate. The creep rate for 20% Y2O3-80% ZrO2 was 1/3 to 1/2 that of 8% Y2O3-92% ZrO2. Both magnesia and calcia stabilized ZrO2 crept at a rate 5 to 10 times that of the 20% Y2O3 material. A near proportionality between creep rate and applied stress was observed. The rate controlling process appeared to be thermally activated, with an activation energy of approximately 100 cal/gm mole K. Creep deformation was due to cracking and particle sliding

Caution fatigue: group identification and disgust provide protection in the COVID-19 pandemic

The current Coronavirus pandemic has yielded an abundance of concerns regarding the psychological effects of isolating a highly social species through widespread lockdowns and enhanced social distancing. Research show that many are suffering from mental health crises, while also refusing to isolate (Brooks et al., 2020; Czeiler, et al., 2020). These behaviors combine to increase risk of viral infection. An emerging term to explain this paradox is “Caution Fatigue”. Yet, there is no research that outlines its specific underlying mechanisms. The goal of this paper is to propose a series of models that delineate caution fatigue through the effects a) uncertainty b) the stereotype content model (Fiske et al., 2002) and c) group identification have on predicting the inhibition of risk perception through disgust. While caution fatigue is not ultimately observed, the conditions which one is willing to engage or mitigate risk are discussed. Unmasked faces are found to be viewed in a more negative affective state than masked faces which lends to increased feelings of group identification alongside uncertainty to promote feelings of disgust and risk. The findings presented here lack to perfectly encapsulate caution fatigue, but there is evidence of xenophobia against members of Asian heritage. Observations and implications are explained further

La Puerta Park

The thesis at hand analyzed ecological corridors, biophilic design, and native planting as individual design entities, and eventually combined them through the creation of a comprehensive park proposal called La Puerta Park. The park was located in the urban matrix of Claremont, CA on a 10-acre parcel of land. The land was recently purchased by Trumark Housing, and a housing development plan was put forth. This project creates a superior alternative to the high levels of impervious surfaces, loss of biodiversity, and lack of community that would ensue after the housing plan implementation. The design process was fluid, as each of the three theories informed one another, producing a cohesive final park proposal. The culminating design offered a precedent for park-making in urban contexts through establishing an interconnected green space hospitable for humans, flora, and fauna

Effect of laser frequency noise on fiber-optic frequency reference distribution

The effect of the linewidth of a single longitude-mode laser on the frequency stability of a frequency reference transmitted over a single-mode optical fiber is analyzed. The interaction of the random laser frequency deviations with the dispersion of the optical fiber is considered to determine theoretically the effect on the Allan deviation (square root of the Allan variance) of the transmitted frequency reference. It is shown that the magnitude of this effect may determine the limit of the ultimate stability possible for frequency reference transmission on optical fiber, but is not a serious limitation to present system performance

A General Theory of Geodesics with Applications to Hyperbolic Geometry

In this thesis, the geometry of curved surfaces is studied using the methods of differential geometry. The introduction of manifolds assists in the study of classical two-dimensional surfaces. To study the geometry of a surface a metric, or way to measure, is needed. By changing the metric on a surface, a new geometric surface can be obtained. On any surface, curves called geodesics play the role of straight lines in Euclidean space. These curves minimize distance locally but not necessarily globally. The curvature of a surface at each point p affects the behavior of geodesics and the construction of geometric objects such as circles and triangles. These fundamental ideas of manifolds, geodesics, and curvature are developed and applied to classical surfaces in Euclidean space as well as models of non-Euclidean geometry, specifically, two-dimensional hyperbolic space

Microwave analog fiber-optic link for use in the deep space network

A novel fiber-optic system with dynamic range of up to 150 dB-Hz for transmission of microwave analog signals is described. The design, analysis, and laboratory evaluations of this system are reported, and potential applications in the NASA/JPL Deep Space Network are discussed

State-of-the-art all-silicon sub-bandgap photodetectors at telecom and datacom wavelengths

Silicon-based technologies provide an ideal platform for the monolithic integration of photonics and microelectronics. In this context, a variety of passive and active silicon photonic devices have been developed to operate at telecom and datacom wavelengths, at which silicon has minimal optical absorption - due to its bandgap of 1.12 eV. Although in principle this transparency window limits the use of silicon for optical detection at wavelengths above 1.1 μm, in recent years tremendous advances have been made in the field of all-silicon sub-bandgap photodetectors at telecom and datacom wavelengths. By taking advantage of emerging materials and novel structures, these devices are becoming competitive with the more well-established technologies, and are opening new and intriguing perspectives. In this paper, a review of the state-of-the-art is presented. Devices based on defect-mediated absorption, two-photon absorption and the internal photoemission effect are reported, their working principles are elucidated and their performance discussed and compared