Pull-in control due to Casimir forces using external magnetic fields

We present a theoretical calculation of the pull-in control in capacitive micro switches actuated by Casimir forces, using external magnetic fields. The external magnetic fields induces an optical anisotropy due to the excitation of magneto plasmons, that reduces the Casimir force. The calculations are performed in the Voigt configuration, and the results show that as the magnetic field increases the system becomes more stable. The detachment length for a cantilever is also calculated for a cantilever, showing that it increases with increasing magnetic field. At the pull-in separation, the stiffness of the system decreases with increasing magnetic field.Comment: accepted for publication in App. Phys. Let

Scaling Laws of Stress and Strain in Brittle Fracture

A numerical realization of an elastic beam lattice is used to obtain scaling exponents relevant to the extent of damage within the controlled, catastrophic and total regimes of mode-I brittle fracture. The relative fraction of damage at the onset of catastrophic rupture approaches a fixed value in the continuum limit. This enables disorder in a real material to be quantified through its relationship with random samples generated on the computer.Comment: 4 pages and 6 figure

Strategies in Software Development Effort Estimation

Software development effort estimating has notoriously been the Achilles heel of the software planning process. Accurately evaluating the effort required to accomplish a software change continues to be problematic, especially in Agile software development. IT organizations and project managers depend on estimation accuracy for planning software deliveries and cost determination. The purpose of this multiple case qualitative study was to identify strategies used by software development professionals in providing accurate effort estimations to stakeholders. The planning fallacy served as the studyâs conceptual framework. The participants were 10 software development professionals who were actively engaged in delivering estimates of effort on software development requests in South Texas in the United States. Data were collected from 10 software development professionals in 5 different organizations. Additionally, 23 organizational documents were gathered and reviewed. Thematic analysis was used to identify codes and themes. Prominent themes were (a) defining and decomposing requirements, (b) referencing historical data, (c) identifying risks and unknowns, and (d) fostering communication, collaboration, and a consensus. A key recommendation is for software developers to ensure requirements are defined and decomposed by evaluating the request and breaking the request into manageable pieces to understand the effort required to complete the task. Implications for positive social change include improving morale, work-life balance, alignment of expectations, and software quality

Laboratory evaluation of stable isotope labeling of Culicoides (Diptera: Ceratopogonidae) for adult dispersal studies.

BackgroundStable isotope labeling is a promising method for use in insect mark-capture and dispersal studies. Culicoides biting midges, which transmit several important animal pathogens, including bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), are small flies that develop in various semi-aquatic habitats. Previous Culicoides dispersal studies have suffered from the limitations of other labeling techniques, and an inability to definitively connect collected adult midges to specific immature development sites.ResultsAdult C. sonorensis were successfully labeled with 13C and 15N stable isotopes as larvae developing in a semi-aquatic mud substrate in the laboratory. High and low-dose isotope treatments for both elements significantly enriched midges above the background isotope levels of unenriched controls. Enrichment had no effect on C. sonorensis survival, though a slight (~ 5 day) delay in emergence was observed, and there was no significant effect of pool size on 13C or 15N enrichment levels.ConclusionsStable isotope labeling is life-long, and does not interfere with natural insect behaviors. Stable isotope enrichment using 13C or 15N shows promise for Culicoides dispersal studies in the field. This method can be used to identify adult dispersal from larval source habitat where a midge developed. It may be possible to detect a single enriched midge in a pool of unenriched individuals, though further testing is needed to confirm the sensitivity of this method

Improved Name-Recognition with Meta-data Dependent Name Networks

A transcription system that requires accurate general name transcription is faced with the problem of covering the large number of names it may encounter. Without any prior knowledge, this requires a large increase in the size and complexity of the system due to the expansion of the lexicon. Furthermore, this increase will adversely affect the system performance due to the increased confusability. Here we propose a method that uses meta-data, available at runtime to ensure better name coverage without significantly increasing the system complexity. We tested this approach on a voicemail transcription task and assumed meta-data to be available in the form of a caller ID string (as it would show up on a caller ID enabled phone) and the name of the mailbox owner. Networks representing possible spoken realization of those names are generated at runtime and included in network of the decoder. The decoder network is built at training time using a class-dependent language model, with caller and mailbox name instances modeled as class tokens. The class tokens are replaced at test time with the name networks built from the meta-data. The proposed algorithm showed a reduction in the error rate of name tokens of 22.1%

Advanced Hydrogen Transport Membranes for Vision 21 Fossil Fuel Plants

The objective of this project was to develop an environmentally benign, inexpensive, and efficient method for separating hydrogen from gas mixtures produced during industrial processes, such as coal gasification. A family of hydrogen separation membranes was developed including single phase mixed conducting ceramics, ceramic/ceramic composites, cermet membranes, cermet membranes containing a hydrogen permeable metal, and intermediate temperature composite layered membranes. Each membrane type had different operating parameters, advantages, and disadvantages that were documented over the course of the project. Research on these membranes progressed from ceramics to cermets to intermediate temperature composite layered membranes. During this progression performance was increased from 0.01 mL x min{sup -1} x cm{sup -2} up to 423 mL x min{sup -1} x cm{sup -2}. Eltron and team membranes not only developed each membrane type, but also membrane surface catalysis and impurity tolerance, creation of thin film membranes, alternative applications such as membrane promoted alkane dehydrogenation, demonstration of scale-up testing, and complete engineering documentation including process and mechanical considerations necessary for inclusion of Eltron membranes in a full scale integrated gasification combined cycle power plant. The results of this project directly led to a new $15 million program funded by the Department of Energy. This new project will focus exclusively on scale-up of this technology as part of the FutureGen initiative

Methodological precision of in situ and in vitro algal density measurements in the model cnidarian, Exaiptasia diaphana

In cnidarian symbiosis research, studying algal uptake, maintenance, and expulsion typically requires quantification of algal density in host tissue. Multiple methods are used to measure algal density including in vitro cell counts of holobiont homogenate and in situ cell counts of tentacle clippings. The relative precision of both types of measurement has not previously been reported for the model cnidarian Exaiptasia diaphana in the fully symbiotic state. The objective of this study was to evaluate the precision of in vitro and in situ algal density measurement protocols using light, fluorescent, and confocal microscopy and an automated cell counter. In situ algal density was quantified as algal area fraction (%) using confocal images of tentacle clippings mounted on two types of slides. In vitro algal density of holobiont homogenate was quantified as algal cells/µl of holobiont homogenate using an automated cell counter and a hemocytometer viewed using light and fluorescent microscopy. Triplicate measurements of each method for ten anemones were collected and the coefficient of variation was calculated and compared across the ten anemones within each method. The algal density measurements were equally precise when they were obtained by quantifying in vitro cell counts using a hemocytometer and when they were obtained by quantifying in situ cell counts. While both light and fluorescent microscopy yielded similar measurement precision of in vitro cell counts, use of a fluorescent microscope was more efficient and convenient than use of a light microscope, and both methods required terminal sampling. Conversely, in situ methods required more sophisticated equipment (namely a confocal microscope) but involved non-terminal sampling. An automated cell counter was ineffective for in vitro quantification of algal density, although the potential utility of this technology warrants future attempts using a more robust algal cell purification process that could include filtering homogenate prior to analysis. This study demonstrated that in vitro and in situ methods yield estimates of algal density with comparable precision, which is information that researchers can use for future studies when making decisions about methodology