Exploring the Design of Pay-Per-Use Objects in the Construction Domain

Equipment used in the construction domain is often hired in order to reduce cost and maintenance overhead. The cost of hire is dependent on the time period involved and does not take into account the actual use equipment has received. This paper presents our initial investigation into how physical objects augmented with sensing and communication technologies can measure use in order to enable new pay-per-use payment models for equipment hire. We also explore user interaction with pay-per-use objects via mobile devices. The user interactions that take place within our prototype scenario range from simple information access to transactions involving multiple users. This paper presents the design, implementation and evaluation of a prototype pay-per-use system motivated by a real world equipment hire scenario. We also provide insights into the various challenges introduced by supporting a pay-per-use model, including data storage and data security in addition to user interaction issues

Nonperturbative contributions to the QCD pressure

We summarize the most important arguments why a perturbative description of finite-temperature QCD is unlikely to be possible and review various well-established approaches to deal with this problem. Then, using a recently proposed method, we investigate nonperturbative contributions to the QCD pressure and other observables (like energy, anomaly and bulk viscosity) obtained by imposing a functional cutoff at the Gribov horizon. Finally, we discuss how such contributions fit into the picture of consecutive effective theories, as proposed by Braaten and Nieto, and give an outline of the next steps necessary to improve this type of calculation.Comment: 15 pages, 13 figures, uses xcolor.sty; in v2 quality of some figures has been improved, discussion of other approaches has been extende

Prospects for a precise equation of state measurement from Advanced LIGO and Cosmic Explorer

Gravitational-wave observations of neutron star mergers can probe the nuclear equation of state by measuring the imprint of the neutron star's tidal deformability on the signal. We investigate the ability of future gravitational-wave observations to produce a precise measurement of the equation of state from binary neutron star inspirals. Since measurability of the tidal effect depends on the equation of state, we explore several equations of state that span current observational constraints. We generate a population of binary neutron stars as seen by a simulated Advanced LIGO-Virgo network, as well as by a planned Cosmic Explorer observatory. We perform Bayesian inference to measure the parameters of each signal, and we combine measurements across each population to determine $R_{1.4}$, the radius of a $1.4M_{\odot}$ neutron star. We find that with 321 signals the LIGO-Virgo network is able to measure $R_{1.4}$ to better than 2% precision for all equations of state we consider, however we find that achieving this precision could take decades of observation, depending on the equation of state and the merger rate. On the other hand we find that with one year of observation, Cosmic Explorer will measure $R_{1.4}$ to better than 0.6% precision. In both cases we find that systematic biases, such as from an incorrect mass prior, can significantly impact measurement accuracy and efforts will be required to mitigate these effects.Comment: 11 pages, 6 figure

Adaptive Variable Bias Magnetic Bearing Control

Most magnetic bearing control schemes use a bias current with a superimposed control current to linearize the relationship between the control current and the force it delivers. With the existence of the bias current, even in no load conditions, there is always some power consumption. In aerospace applications, power consumption becomes an important concern. In response to this concern, an alternative magnetic bearing control method, called Adaptive Variable Bias Control (AVBC), has been developed and its performance examined. The AVBC operates primarily as a proportional-derivative controller with a relatively slow, bias current dependent, time-varying gain. The AVBC is shown to reduce electrical power loss, be nominally stable, and provide control performance similar to conventional bias control. Analytical, computer simulation, and experimental results are presented in this paper

Lethal Mutagenesis of Poliovirus Mediated by a Mutagenic Pyrimidine Analogue

Lethal mutagenesis is the mechanism of action of ribavirin against poliovirus (PV) and numerous other RNA viruses. However, there is still considerable debate regarding the mechanism of action of ribavirin against a variety of RNA viruses. Here we show by using T7 RNA polymerase mediated production of PV genomic RNA, PV polymerase-catalyzed primer extension and cell-free PV synthesis that a pyrimidine ribonucleoside triphosphate analogue (rPTP) with ambiguous basepairing capacity is an efficient mutagen of the PV genome. The in vitro incorporation properties of rPTP are superior to ribavirin triphosphate. We observed a log-linear relationship between virus titer reduction and the number of rPMP molecules incorporated. A PV genome encoding a high-fidelity polymerase was more sensitive to rPMP incorporation, consistent with diminished mutational robustness of high-fidelity PV. The nucleoside (rP) did not exhibit antiviral activity in cell culture owing to the inability of rP to be converted to rPMP by cellular nucleotide kinases. rP was also a poor substrate for herpes simplex virus thymidine kinase. The block to nucleoside phosphorylation could be bypassed by treatment with the P nucleobase, which exhibited both antiviral activity and mutagenesis, presumably a reflection of rP nucleotide formation by a nucleotide salvage pathway. These studies provide additional support for lethal mutagenesis as an antiviral strategy, suggest that rPMP prodrugs may be highly efficacious antiviral agents, and provide a new tool to determine the sensitivity of RNA virus genomes to mutagenesis as well as interrogation of the impact of mutational load on the population dynamics of these viruses

A high-resolution transmission-type x-ray spectrometer designed for observation of the Kα transitions of highly charged high-Z ions

High-resolution reflection-type crystal spectrometers have been used for x-ray energies up to 13 keV, e.g., the K-shell radiation of heliumlike Kr. In order to extend crystal spectrometer measurements to higher energy x rays from higher-Z elements, we employ the crystal in transmission. The geometry we use is known as DuMond geometry. Using such a transmission-type crystal x-ray spectrometer, we have measured the K-shell radiation of various highly charged high-Z ions. In particular, we present a measurement of the 1s2p 1P1→1s2 1S0 transition in heliumlike xenon, Xe52+. For this transition, we measure a linewidth of 34 eV, which demonstrates that the resolving power we achieved with the new spectrometer is on the order of 100

Potentiometric enzyme channelling immunosensor for proteins

A potentiometric immunosensor for the detection of human IgG has been developed using an asymmetric, ion-selective membrane with immobilized adenosine deaminase and IgG. A protein A-alkaline phosphatase conjugate binds to the immobilized IgG, creating a bienzymatic catalytic layer. In the presence of sample IgG, the conjugate does not bind to the membrane. Instead, the intermediate in the two-step reaction (adenosine) must diffuse to the membrane surface, reducing the rate of product (ammonium) formation within the diffusion layer detected by the membrane. The immunosensor demonstrated is for the determination of IgG. A simplified model is described to predict the maximum rate enhancement for the `channeled' versus `unchanneled' reaction mechanisms.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29631/1/0000720.pd

Disinhibiting neurons in the dorsomedial hypothalamus delays the onset of exertional fatigue and exhaustion in rats exercising in a warm environment

Stimulants cause hyperthermia, in part, by increasing heat generation through exercise. Stimulants also delay the onset of fatigue and exhaustion allowing animals to exercise longer. If used in a warm environment, this combination (increased exercise and decreased fatigue) can cause heat stroke. The dorsomedial hypothalamus (DMH) is involved in mediating locomotion from stimulants. Furthermore, inhibiting the DMH decreases locomotion and prevents hyperthermia in rats given stimulants in a warm environment. Whether the DMH is involved in mediating exercise-induced fatigue and exhaustion is not known. We hypothesized that disinhibiting neurons in the dorsomedial hypothalamus (DMH) would delay the onset of fatigue and exhaustion in animals exercising in a warm environment. To test this hypothesis, we used automated video tracking software to measure fatigue and exhaustion. In rats, using wearable mini-pumps, we demonstrated that disinhibiting the DMH, via bicuculline perfusion (5 µM), increased the duration of exercise in a warm environment as compared to control animals (25 ± 3 min vs 15 ± 2 min). Bicuculline-perfused animals also had higher temperatures at exhaustion (41.4 ± 0.2 °C vs 40.0 ± 0.4 °C). Disinhibiting neurons in the DMH also increased the time to fatigue. Our data show that the same region of the hypothalamus that is involved in mediating locomotion to stimulants, is also involved in controlling exhaustion and fatigue. These findings have implications for understanding the cause and treatment of stimulant-induced-hyperthermia

Shear thickening of cornstarch suspensions

We study the rheology of cornstarch suspensions, a non-Brownian particle system that exhibits discontinuous shear thickening. Using magnetic resonance imaging (MRI), the local properties of the flow are obtained by the determination of local velocity profiles and concentrations in a Couette cell. For low rotational rates, we observe shear localization characteristic of yield stress fluids. When the overall shear rate is increased, the width of the sheared region increases. The discontinuous shear thickening is found to set in at the end of this shear localization regime when all of the fluid is sheared: the existence of a nonflowing region, thus, seems to prevent or delay shear thickening. Macroscopic observations using different measurement geometries show that the smaller the gap of the shear cell, the lower the shear rate at which shear thickening sets in. We, thus, propose that the discontinuous shear thickening of cornstarch suspensions is a consequence of dilatancy: the system under flow attempts to dilate but instead undergoes a jamming transition, because it is confined. This proposition is confirmed by an independent measurement of the dilation of the suspension as a function of the shear rate. It is also explains the MRI observations: when flow is localized, the nonflowing region plays the role of a "dilatancy reservoir" which allows the material to be sheared without jamming.Comment: arXiv admin note: text overlap with arXiv:0709.3171, and with arXiv:1101.2309, arXiv:cond-mat/0406422 by other author