Buckling Eigenvalues for a Clamped Plate Embedded in an Elastic Medium and Related Questions

This paper considers the dependence of the sum of the first m eigenvalues of three classical problems from linear elasticity on a physical parameter in the equation. The paper also considers eigenvalues $\gamma _i (a)$ of a clamped plate under compression, depending on a lateral loading parameter $a;\Lambda i(a)$, the Dirichlet eigenvalues of the elliptic system describing linear elasticity depending on a combination a of the Lame constants, and eigenvalues $\Gamma _i (a)$ of a clamped vibrating plate under tension, depending on the ratio a of tension and flexural rigidity. In all three cases $a \in [0,\infty )$. The analysis of these eigenvalues and their dependence on a gives rise to some general considerations on singularly perturbed variational problems

Investigation of passive flow control techniques to enhance the stall characteristics of a microlight aircraft

This report investigates the enhancement of aerodynamic stall characteristics of a Skyranger microlight aircraft by the use of passive flow control techniques, namely vortex generators and turbulators. Each flow control device is designed and scaled to application conditions. Force balance measurements and surface oil flow visualisation are carried out on a half-model of the microlight to further investigate the nature of the flow on the aircraft with and without the flow control devices. The results indicate a clear advantage to the use of turbulators compared with vortex generators. Turbulators increased the maximum lift coefficient by 2.8%, delayed the onset of stall by increasing the critical angle by 17.6% and reduced the drag penalty at both lower (pre-stall) and higher angles of attack by 8% compared to vortex generators. With vortex generators applied, the results indicated a delayed stall with an increase in the critical angle by 2% and a reduced drag penalty at higher angles of attack

Brief Amici Curiae Legal Scholars of Sex and Gender In Support of Plaintiff-Appellant

This amicus brief was filed in Griffith v. El Paso County, Colorado, case no. 23-1135 (10th Circuit) in support of appellant Darlene Griffith. Amici curiae are legal scholars of sex and gender. They offerexpertise in their personal capacities to assist the Court of Appeals for the Tenth Circuit in assessing whether the El Paso County Sheriff officials violated Ms. Griffith’s Fourteenth Amendment right to equal protection when they refused to house Ms. Griffith, a transgender woman, in the women\u27s unit of the El Paso County Jail as a pretrial detainee

Multichannel read-out for arrays of metallic magnetic calorimeters

Metallic magnetic micro-calorimeters (MMCs) operated at millikelvin temperature offer the possibility to achieve eV-scale energy resolution with high stopping power for X-rays and massive particles in an energy range up to several tens of keV. This motivates their use in a wide range of applications in fields as particle physics, atomic and molecular physics. Present detector systems consist of MMC arrays read out by 32 two-stage SQUID read-out channels. In contrast to the design of the detector array and consequently the design of the front-end SQUIDs, which need to be optimised for the physics case and the particles to be detected in a given experiment, the read-out chain can be standardised. We present our new standardised 32-channel parallel read-out for the operation of MMC arrays to be operated in a dilution refrigerator. The read-out system consists of a detector module, whose design depends on the particular application, an amplifier module, ribbon cables from room temperature to the millikelvin platform and a data acquisition system. In particular, we describe the realisation of the read-out system prepared for the ECHo-1k experiment for the operation of two 64-pixel arrays. The same read-out concept is also used for the maXs detector systems, developed for the study of the de-excitation of highly charged heavy ions by X-rays, as well as for the MOCCA system, developed for the energy and position sensitive detection of neutral molecular fragments for the study of fragmentation when molecular ions recombine with electrons. The choice of standard modular components for the operation of 32-channel MMC arrays offer the flexibility to upgrade detector modules without the need of any changes in the read-out system and the possibility to individually exchange parts in case of damages or failures

Hybrid cloud computing architecture based on open source technology

The advance of technologies such as distributed computing, Internetand grid computing, have enabled Cloud Computing to become part of a new model of computing and business. Cloud Computing is transforming the traditional ways in which companies use and acquire Information Technology (IT) resources. After an initial boom in Public Cloud, companies begun to mount hybrid Clouds that offer the advantages of Cloud Computing in addition to the privacy of data they consider strategic. A hybrid Cloud solution allows the integration of both systems. Leading companies in cloud solutions have understood this evolution and begun to offer hybrid solutions. Moreover, many of these companies are taking the next step by offering solutions based on open source standards that allow a high degree of interoperability and portability

High-resolution and low-background 163^{163}Ho spectrum: interpretation of the resonance tails

The determination of the effective electron neutrino mass via kinematic analysis of beta and electron capture spectra is considered to be model-independent since it relies on energy and momentum conservation. At the same time the precise description of the expected spectrum goes beyond the simple phase space term. In particular for electron capture processes, many-body electron-electron interactions lead to additional structures besides the main resonances in calorimetrically measured spectra. A precise description of the $^{163}$Ho spectrum is fundamental for understanding the impact of low intensity structures at the endpoint region where a finite neutrino mass affects the shape most strongly. We present a low-background and high-energy resolution measurement of the $^{163}$Ho spectrum obtained in the framework of the ECHo experiment. We study the line shape of the main resonances and multiplets with intensities spanning three orders of magnitude. We discuss the need to introduce an asymmetric line shape contribution due to Auger–Meitner decay of states above the auto-ionisation threshold. With this we determine an enhancement of count rate at the endpoint region of about a factor of 2, which in turn leads to an equal reduction in the required exposure of the experiment to achieve a given sensitivity on the effective electron neutrino mass