Third Interger Resonance Slow Extraction Using RFKO at High Space Charge

A proposal to search for direct {\mu}-->e conversion at Fermilab requires slow, resonant extraction of an intense proton beam. Large space charge forces will present challenges, partly due to the substantial betatron tune spread. The main challenges will be maintaining a uniform spill profile and moderate losses at the septum. We propose to use "radio frequency knockout" (RFKO) for fine tuning the extraction. Strategies for the use of the RFKO method will be discussed here in the context of the Mu2e experiment. The feasibility of this method has been demonstrated in simulations.Comment: 3 pp. 2nd International Particle Accelerator Conference: IPAC 2011. 4-9 Sep 2011. San Sebastian, Spai

Modeling of Biorefinery Supply Chain Economic Performance with Discrete Event Simulation

As competition for fossil fuels accelerates, alternative sources of chemicals, fuels, and energy production become more appealing to researchers and the layman. Among the candidates to fill this growing niche is lignocellulosic biomass. Many researchers have examined supply chain design and optimization for biofuel and bioenergy production throughout the years. However, these models often fail to capture the variability and uncertainty inherent to the biomass supply chain. Multiple factors with high degrees of stochasticity can have major impacts on the performance of a biorefinery: weather, biomass quality, feedstock availability, and market demand for products are just a few. To begin to address this issue, a discrete event simulation model has been developed to examine the economic performance of a region specific, multifeedstock biorefinery supply chain. Probability distributions developed for product demand and feedstock supply begin to address the random nature of the supply chain. Model development is discussed in the context of a multidisciplinary framework for biorefinery supply chain design. A case study, sensitivity analysis, and scenario analysis, are utilized to examine the capabilities of the model

Should Twins Share An Elementary School Classroom?

In any child’s educational experience, there are positive and negative aspects. However, when jealousy and competition, identity and dependence, separation anxiety, and a host of other emotionally charged aspects of school life, are added to the situation, the elementary classroom becomes a minefield for all involved, especially for twins. It is this minefield that parents, states, and educational professionals walk students through, all while seeking each child’s best interest. However, there are conflicting opinions, research, and practices that mark the historical landscape of whether to educate twins in a shared elementary school classroom. The historical trend within the greater United States of America has been that the Principal and other educational professionals shall decide whether twins are placed together or separate. The scarcity of quantitative research has left many professionals with an “old school” view of automatically assigning twin pairs to separate classrooms. Entering the school environment is usually the first time parents, teachers, and other educational professionals determine whether to separate twin children or place them together in the same classroom. This decision is based upon the twin relationship, parents’ views, state laws, and professional educators’ opinions. By researching and gathering data from the past and present, a conclusion may be put forth for discussion by parents, and professionals to allow for the most student support possible. Should twins share an elementary school classroom

The impact of land use change on C turnover in soils

Measurements of CO2 flux, soil temperature, and moisture content of selected natural and disturbed soils in central California were made on a monthly basis from August 1994 to October 1995 in an attempt to detect the effects of temperature, moisture, and land use change on CO2 production in soils. Soil CO2 flux displayed a strong negative correlation with soil temperature and a positive correlation with soil moisture at the natural site. However, at the disturbed site, the linear correlation between CO2 flux and temperature/moisture was insignificant. The negative correlation between soil CO2 flux and soil temperature is in contrast to what has been observed in other ecosystems but is typical for Mediterranean ecosystems in which grasses are biologically active only during cool months. Comparison of carbon (C) inventories of paired natural and disturbed soils indicates that both cultivation and logging have resulted in a significant decrease in total soil C content. The reduction in soil C storage is about 26% for the cultivated soil and around 30% for the logged soil. Most of the C loss is from the upper horizons. Radiocarbon (C-14) measurements of both recent and archived soil samples demonstrate large differences in C input rate and turnover time between natural and disturbed soils. The average turnover times of organic matter are longer in disturbed soils than in the corresponding natural soils as a result of preferential loss of C from "active" soil C pools. In both natural and disturbed soils, the average turnover times of organic matter increase with depth from decades or less in shallow horizons to hundreds of years or even thousands of years in deeper horizons. Our results show that land use change can have significant impact on soil C cycle and that shallow soil horizons are most susceptible to disturbance because of shorter turnover times of organic C in these horizons

Phase separation transition in liquids and polymers induced by electric field gradients

Spatially uniform electric fields have been used to induce instabilities in liquids and polymers, and to orient and deform ordered phases of block-copolymers. Here we discuss the demixing phase transition occurring in liquid mixtures when they are subject to spatially nonuniform fields. Above the critical value of potential, a phase-separation transition occurs, and two coexisting phases appear separated by a sharp interface. Analytical and numerical composition profiles are given, and the interface location as a function of charge or voltage is found. The possible influence of demixing on the stability of suspensions and on inter-colloid interaction is discussed.Comment: 7 pages, 3 figures. Special issue of the J. Phys. Soc. Ja

Radiative Neutralino Decay in Supersymmetric Models

The radiative decay Z2-> Z1 gamma proceeds at the one-loop level in the MSSM. It can be the dominant decay mode for the second lightest neutralino Z2 in certain regions of parameter space of supersymmetric models, where either a dynamical and/or kinematic enhancement of the branching fraction occurs. We perform an updated numerical study of this decay mode in both the minimal supergravity model (mSUGRA) and in the more general MSSM framework. In mSUGRA, the largest rates are found in the ``focus point'' region, where the mu parameter becomes small, and the lightest neutralinos become higgsino-like; in this case, radiative branching fraction can reach the 1% level. Our MSSM analysis includes a scan over independent positive and negative gaugino masses. We show branching fractions can reach the 10-100% level even for large values of the parameter tan(beta). These regions of parameter space are realized in supergravity models with non-universal gaugino masses. Measurement of the radiative neutralino branching fraction may help pin down underlying parameters of the fundamental supersymmetric model.Comment: 19 page JHEP file with 8 PS figures; previous version contained figure misplacemen

Environmental Effects on Pregnancy Rate in Beef Cattle

Ten years of calving records were examined from Bos taurus crossbred cows (mean of 182 cows/ yr) to quantify the effects of environmental conditions during the breeding season on pregnancy rate. Estimated breeding dates were determined by subtracting 283 d from the calving date. Relationships were determined between the proportion of cows bred during the periods from the beginning of the breeding season until d 21, 42, and 60 of the breeding season and the corresponding environmental variables. Weather data were compiled from a weather station located approximately 20 km from the research site. Average daily temperature and relative humidity were used to calculate daily temperature-humidity index (THI). Daily averages for each environmental variable were averaged for each period. Minimum temperature (MNTP) and THI for the first 21 and 42 d of the breeding season were negatively associated (P \u3c 0.001) with pregnancy rate. For the 0- to 21-d, 0- to 42-d, and 0- to 60-d breeding periods, respective r2 for average temperatures were 0.32, 0.37, and 0.11, whereas r2 for MNTP were 0.45, 0.40, and 0.10 and r2 for THI were 0.38, 0.41, and 0.11, respectively, for the same breeding periods. The negative associations of temperature and THI with pregnancy rate are most pronounced during the first 21 d of the breeding season, with a −3.79 and −2.06% change in pregnancy rate for each unit of change in MNTP and THI, respectively. A combination of environmental variables increased the R2 to 0.67. In this analysis, windspeed was found to be positively associated with pregnancy rate in all equations and increased the R2 in all breeding periods. Optimum MNTP for the 0- to 21-d, 0- to 42-d, and 0- to 60- d breeding periods was 12.6, 13.5, and 14.9°C, respectively. For the 0- to 60-d breeding period, optimum THI was 68.0, whereas the THI threshold, the calculated level at which cattle will adapt, was found to be 72.9. Reductions in pregnancy rate are likely when the average MNTP and THI equal or exceed 16.7°C and 72.9, respectively, and for Bos Taurus beef cows that are pasture bred during a 60-d spring-summer period

Tracking icebergs with time-lapse photography and sparse optical flow, LeConte Bay, Alaska, 2016–2017

We present a workflow to track icebergs in proglacial fjords using oblique time-lapse photos and the Lucas-Kanade optical flow algorithm. We employ the workflow at LeConte Bay, Alaska, where we ran five time-lapse cameras between April 2016 and September 2017, capturing more than 400 000 photos at frame rates of 0.5–4.0 min−1. Hourly to daily average velocity fields in map coordinates illustrate dynamic currents in the bay, with dominant downfjord velocities (exceeding 0.5 m s−1 intermittently) and several eddies. Comparisons with simultaneous Acoustic Doppler Current Profiler (ADCP) measurements yield best agreement for the uppermost ADCP levels (∼ 12 m and above), in line with prevalent small icebergs that trace near-surface currents. Tracking results from multiple cameras compare favorably, although cameras with lower frame rates (0.5 min−1) tend to underestimate high flow speeds. Tests to determine requisite temporal and spatial image resolution confirm the importance of high image frame rates, while spatial resolution is of secondary importance. Application of our procedure to other fjords will be successful if iceberg concentrations are high enough and if the camera frame rates are sufficiently rapid (at least 1 min−1 for conditions similar to LeConte Bay).This work was funded by the U.S. National Science Foundation (OPP-1503910, OPP-1504288, OPP-1504521 and OPP-1504191).Ye