Analysis of Turnability for a Three Terminal Microwave Network

Three-terminal microwave networks can be shown to exhibit qualities that would make them desirable to be used as multiple terminal devices. Using microwave theory, where instantaneous voltage is a function of position on the line, this situation will be examined. These devices use the interference principle of propagating waves as the basis of their characteristics. This investigation will probe a three- terminal microwave network with one input and two output. This configuration acts similar to a splitter where the outputs may be controlled. These three terminals, plus manipulation of the lengths of each side, actually makes this a four terminal device, much like a transistor with one source, one gate, and two drains. The three terminal network will be examined in a situation such that the lengths of two of the sides will be varied and the wavelength will be held constant. The power of the signal at each of the output terminals, along with reflected power will be recorded. By using a case where the total length of the ring is an integer number of wavelengths, two cases of behavior arise. One case exhibits qualities much like the Aharanov-Bohm effect. The other case has tendencies to reflect most of the incoming signal, except near equal length sides

Soft interactions in Herwig++

We describe the recent developments to extend the multi-parton interaction model of underlying events in Herwig++ into the soft, non-perturbative, regime. This allows the program to describe also minimum bias collisions in which there is no hard interaction, for the first time. It is publicly available from versions 2.3 onwards and describes the Tevatron underlying event and minimum bias data. The extrapolations to the LHC nevertheless suffer considerable ambiguity, as we discuss.Comment: 10 pages, talk given by Manuel Bahr at First International Workshop on Multiple Partonic Interactions at the LHC, "MPI@LHC'08", Perugia, Italy, October 27-31 200

Statistical analysis of nanoindentation hardness and pop-in behavior: variation as a characterization tool

Accurate determination of nanomechanical materials properties is required for successful nanoscale materials characterization and subsequent design. Advancements in indentation science have been made in recent decades; however, widely varying nanoindentation hardness and elastic moduli are still currently reported in the literature on nominally similar samples, particularly at small depths or when only a few tests can be carried out in a limited sample volume. The study explores changes in the variation of hardness of platinum tested at five different depths between 50 and 300 nm for three different dislocation densities. Analysis of nearly 1500 indents showed that the coefficient of variation in hardness increases with decreasing dislocation density and sampling volume. Dislocation density plays a critical role in the variation, beyond solely instrumentation uncertainty, and supports a defect-based explanation for the stochastic behavior. The elasto-plastic transition has also been studied from a statistical standpoint. There is substantial research on the first so-called pop-in, however there has been little research concerning muliple pop-in events. Software has been developed for detecting first and subsequent pop-ins from indentation load-depth curves. The analysis of many indentation tests, combined with well-accepted models of deformation evolution allows nanoindentation to be used as a tool for characterizing dislocation density in crystalline materials. Heavily worked materials containing many preexisting dislocations exhibit little or no initial pop-in and no subsequent pop-ins. Alternatively, after annealing to reduce the dislocation content, larger and later pop-ins are exhibited. Other microstructural features such as impurities may be detected. This study additionally explores the transition from staircase yielding to bulk plasticity

Exploiting plume structure to decode gas source distance using metal-oxide gas sensors

Estimating the distance of a gas source is important in many applications of chemical sensing, like e.g. environmental monitoring, or chemically-guided robot navigation. If an estimation of the gas concentration at the source is available, source proximity can be estimated from the time-averaged gas concentration at the sensing site. However, in turbulent environments, where fast concentration fluctuations dominate, comparably long measurements are required to obtain a reliable estimate. A lesser known feature that can be exploited for distance estimation in a turbulent environment lies in the relationship between source proximity and the temporal variance of the local gas concentration – the farther the source, the more intermittent are gas encounters. However, exploiting this feature requires measurement of changes in gas concentration on a comparably fast time scale, that have up to now only been achieved using photo-ionisation detectors. Here, we demonstrate that by appropriate signal processing, off-theshelf metal-oxide sensors are capable of extracting rapidly fluctuating features of gas plumes that strongly correlate with source distance. We show that with a straightforward analysis method it is possible to decode events of large, consistent changes in the measured signal, so-called ‘bouts’. The frequency of these bouts predicts the distance of a gas source in wind-tunnel experiments with good accuracy. In addition, we found that the variance of bout counts indicates cross-wind offset to the centreline of the gas plume. Our results offer an alternative approach to estimating gas source proximity that is largely independent of gas concentration, using off-the-shelf metal-oxide sensors. The analysis method we employ demands very few computational resources and is suitable for low-power microcontrollers

A model of non-perturbative gluon emission in an initial state parton shower

We consider a model of transverse momentum production in which non-perturbative smearing takes place throughout the perturbative evolution, by a simple modification to an initial state parton shower algorithm. Using this as the important non-perturbative ingredient, we get a good fit to data over a wide range of energy. Combining it with the non-perturbative masses and cutoffs that are a feature of conventional parton showers also leads to a reasonable fit. We discuss the extrapolation to the LHC.Comment: 14 pages, 6 figures; version accepted by JHE

Development of a platform expression system using targeted integration in Chinese Hamster Ovary cells

In recent years the biomanufacturing industry has seen significant improvements in recombinant protein production titers due to advancements in protein expression technologies as well as media, feed and manufacturing process development. However, the standard methods of recombinant cell line development have remained relatively unchanged. The majority of the biopharma industry introduces transgenes into Chinese Hamster Ovary (CHO) cells using mechanical or chemical transfection processes followed by metabolic or antibiotic selection of stable recombinant pools. Through this process, the transgene(s) are randomly integrated into the genome, often times resulting in significant heterogeneity within the stable pools. Individual recombinant CHO cells within the pools can vary greatly in their growth and productivity profiles, product quality attributes, and genetic stability. To isolate and identify the best performers, the time and resource consuming process of single cell clone generation and characterization is used, commonly requiring hundreds to thousands of clones to be characterized to find those suitable for manufacturing processes. In contrast, the use of targeted gene integration in cell line development programs will shorten timelines and reduce the burden of clone screening and characterization. The ability to integrate transgenes at a well-characterized and stable site will decrease heterogeneity in stable pools and lead to more consistent clone performance and product quality. Targeted Integration can also enable researchers to perform specific modifications of glycosylation and metabolic pathways but this abstract will focus more on improving cell line development and manufacturing applications. In this abstract we describe our strategy for developing a CHO expression platform that enables targeted and site specific integration of transgenes. We have generated clonal cell lines in which a landing pad has been randomly integrated into the CHOZN® genome at a low copy number. The landing pad contains a recombinant IgG expression cassette enabling us to screen for clones that support high and stable recombinant protein expression. Following this approach, we have identified and characterized several high expressing landing pad clones with performance characteristics suitable for commercial manufacturing processes. To bring these clones to the CHO industry we must first remove our IgG cassette from the landing pad and exchange it with a regulatory friendly and easy to screen GFP reporter. The landing pad was designed with Lox sites flanking the IgG cassette so that it could be excised using Cre Recombinase Mediated Cassette Exchange (RMCE). The landing pad itself remains integrated in the genome and acts as a placeholder for future site specific integration. Following another round of single cell cloning and characterization we can ensure that the original IgG cassette was cleared from the CHO genome and only the GFP reporter is expressed at the landing pad site. Our team is currently testing all of the top clones that have been derived from this process to select a single clone that will be taken forward for commercialization. We are hoping that upstream biopharma teams will soon be able to integrate their clinical molecules into a landing pad site available in our CHO cell line. The ability to integrate a transgene at a single genomic locus should decrease off target effects and increase the homogeneity of the resulting pools, thus reducing the burden and time required for clone screening and stability studies. Biopharma teams using such a platform expression system will be able to generate more high producing clones with fewer resources and get pipeline molecules to clinic more quickly

The Nolan House

As a precedent, The Green Team analyzed the history of glass architecture, literature, and culture. Based on our research, we found that glass is often depicted as breakable, delicate, and a way to expose or display aspects that would otherwise be hidden. We challenged ourselves to incorporate safety and privacy into our glass house as a way to combat the pre-existing notions of glass in architecture

Phase Noise of SAW Delay Line Magnetic Field Sensors

Surface acoustic wave (SAW) sensors for the detection of magnetic fields are currently being studied scientifically in many ways, especially since both their sensitivity as well as their detectivity could be significantly improved by the utilization of shear horizontal surface acoustic waves, i.e., Love waves, instead of Rayleigh waves. By now, low-frequency limits of detection (LOD) below 100 pT/Hz can be achieved. However, the LOD can only be further improved by gaining a deep understanding of the existing sensor-intrinsic noise sources and their impact on the sensor's overall performance. This paper reports on a comprehensive study of the inherent noise of SAW delay line magnetic field sensors. In addition to the noise, however, the sensitivity is of importance, since both quantities are equally important for the LOD. Following the necessary explanations of the electrical and magnetic sensor properties, a further focus is on the losses within the sensor, since these are closely linked to the noise. The considered parameters are in particular the ambient magnetic bias field and the input power of the sensor. Depending on the sensor's operating point, various noise mechanisms contribute to f0 white phase noise, f-1 flicker phase noise, and f-2 random walk of phase. Flicker phase noise due to magnetic hysteresis losses, i.e. random fluctuations of the magnetization, is usually dominant under typical operating conditions. Noise characteristics are related to the overall magnetic and magnetic domain behavior. Both calculations and measurements show that the LOD cannot be further improved by increasing the sensitivity. Instead, the losses occurring in the magnetic material need to be decreased