Foliated Lie systems: Theory and applications

A $\mathcal{F}$- foliated Lie system is a first-order system of ordinary differential equations whose particular solutions are contained in the leaves of the foliation $\mathcal{F}$ and all particular solutions within any leaf can be written as a certain function, a so-called foliated superposition rule, of a family of particular solutions of the system within the same leaf and several parameters. We analyse the properties of such systems and we illustrate our results by studying Lax pairs and a class of $t$-dependent Hamiltonian systems. We finally study foliated Lie systems through Poisson structures and $r$-matrices.Comment: 24 page

When Buying Fresh Apples and Tomatoes Will Consumers Pay Extra to Have Country of Origin Labeling?

Consumer/Household Economics,

COOL and Consumers' Willingness to Pay in the Fresh Produce Industry - Some Initial Impressions from the Field

The debate about Country-of-Origin labeling (COOL) has centered on the projected benefits and costs of its implementation. This study uses data from a Vickery auction (n=320) to estimate willingness to pay for COOL. Preliminary findings suggest, on average, consumers value COOL, are not homogenous, and prefer fresh produce grown in the U.S.Food Consumption/Nutrition/Food Safety, International Relations/Trade,

COOL AND CONSUMERS' WILLINGNESS TO PAY IN THE FRESH PRODUCE INDUSTRY - SOME INITIAL IMPRESSIONS FROM THE FIELD

The debate about Country-of-Origin labeling (COOL) has centered on the projected benefits and costs of its implementation. This study uses data from a Vickery auction (n=200) to estimate willingness to pay for COOL. Preliminary findings suggest, on average, consumers value COOL, are not homogeneous, and prefer fresh produce grown in the U.S.Consumer/Household Economics,

Stratified lie systems: theory and applications

A stratified Lie system is a nonautonomous system of first-order ordinary differential equations on a manifold M described by a t-dependent vector field $X={\sum }_{\alpha =1}^{r}{g}_{\alpha }{X}_{\alpha }$, where X1, ..., Xr are vector fields on M spanning an r-dimensional Lie algebra that are tangent to the strata of a stratification $\mathcal{F}$ of M while ${g}_{1},\dots ,{g}_{r}:\mathbb{R}\times M\to \mathbb{R}$ are functions depending on t that are constant along integral curves of X1, ..., Xr for each fixed t. We analyse the particular solutions of stratified Lie systems and how their properties can be obtained as generalisations of those of Lie systems. We illustrate our results by studying Lax pairs and a class of t-dependent Hamiltonian systems. We study stratified Lie systems with compatible geometric structures. In particular, a class of stratified Lie systems on Lie algebras are studied via Poisson structures induced by r-matrices

Plasma gate switch experiment on Pegasus II

The plasma gate switch is a novel technique for producing a long conduction time vacuum opening switch. The switch consists of an aluminum foil which connects the cathode to the anode in a coaxial geometry. The foil is designed so that the maximum axial acceleration is in the center of the foil and that at the appropriate time, the center opens up and magnetic flux is carried down the gun to the load region. The switch is designed to minimize the amount of mass transported into the load region. We have completed the first experimental test of this design and present results from the test. These results indicate there were some asymmetry problems in the construction of the switch but that otherwise the switch performed as expected

Dynamics of lane formation in driven binary complex plasmas

The dynamical onset of lane formation is studied in experiments with binary complex plasmas under microgravity conditions. Small microparticles are driven and penetrate into a cloud of big particles, revealing a strong tendency towards lane formation. The observed time-resolved lane formation process is in good agreement with computer simulations of a binary Yukawa model with Langevin dynamics. The laning is quantified in terms of the anisotropic scaling index, leading to a universal order parameter for driven systems.Comment: 4 pages, 3 figures, movies available at http://www.mpe.mpg.de/pke/lane-formation

The use of mesh in acute hernia: frequency and outcome in 99 cases

Background: Incarceration of inguinal, umbilical and cicatricial hernias is a frequent problem. However, little is known about the relationship between the use of mesh and outcome after surgery. The goal of this study was to describe the relationship between the use of mesh in incarcerated hernia and the clinical outcome. Patients and methods: Correspondence, operation reports and patient files between January 1995 and December 2005 of patients presented at one academic and one teaching hospital in Rotterdam were searched for the following keywords: incarceration, strangulation and hernia. The patient characteristics, clinical presentation, pre-operative findings and clinical course were scored and analysed. Results: A total of 203 patients could be identified: 76 inguinal, 52 umbilical, 39 incisional, 14 epigastric, 14 femoral, five trocar and three spigelian hernias. In the statistical analysis, epigastric, femoral, trocar and spigelian hernias were pooled, due to their small group sizes. One patient was excluded from the analysis because the hernia was not corrected during operation. In total, 99 hernias were repaired using mesh versus 103 primary suture repairs. Twenty-five wound infections were registered (12.3%). One mesh was removed during a reintervention for anastomotic leakage, although no signs of wound infection were present. Nine patients died, none of them due to wound-related problems [one cardiovascular, one ruptured aneurysm, two anastomotic leakage, two sepsis e causa incognita (e.c.i.), three pulmonary complications]. Univariate analysis showed that female patients (P = 0.007), adipose patients (P = 0.016), patients with an umbilical hernia (P = 0.01) and patients who underwent a bowel resection (P = 0.015) had a significantly higher rate of wound infections. The type of repair (e.g. primary suture or mesh), use of antibiotic prophylaxis, gender, ASA class and age showed no significant relation with post-operative wound infection. After logistic regression analysis, only bowel resection (P = 0.020) showed a significant relation with post-operative wound infection. Conclusions: Wound infection rates are high after the correction of acute hernia, but clinical consequences are relatively low. Mesh correction of an acute hernia seems to be safe and should be considered in every incarcerated hernia

Lightning Pin Injection Testing on MOSFETS

Lightning transients were pin-injected into metal-oxide-semiconductor field-effect transistors (MOSFETs) to induce fault modes. This report documents the test process and results, and provides a basis for subsequent lightning tests. MOSFETs may be present in DC-DC power supplies and electromechanical actuator circuits that may be used on board aircraft. Results show that unprotected MOSFET Gates are susceptible to failure, even when installed in systems in well-shielded and partial-shielded locations. MOSFET Drains and Sources are significantly less susceptible. Device impedance decreased (current increased) after every failure. Such a failure mode may lead to cascading failures, as the damaged MOSFET may allow excessive current to flow through other circuitry. Preliminary assessments on a MOSFET subjected to 20-stroke pin-injection testing demonstrate that Breakdown Voltage, Leakage Current and Threshold Voltage characteristics show damage, while the device continues to meet manufacturer performance specifications. The purpose of this research is to develop validated tools, technologies, and techniques for automated detection, diagnosis and prognosis that enable mitigation of adverse events during flight, such as from lightning transients; and to understand the interplay between lightning-induced surges and aging (i.e. humidity, vibration thermal stress, etc.) on component degradation