Electron Cloud Buildup Characterization Using Shielded Pickup Measurements and Custom Modeling Code at CESRTA

The Cornell Electron Storage Ring Test Accelerator experimental program includes investigations into electron cloud buildup, applying various mitigation techniques in custom vacuum chambers. Among these are two 1.1-m-long sections located symmetrically in the east and west arc regions. These chambers are equipped with pickup detectors shielded against the direct beam-induced signal. They detect cloud electrons migrating through an 18-mm-diameter pattern of small holes in the top of the chamber. A digitizing oscilloscope is used to record the signals, providing time-resolved information on cloud development. Carbon-coated, TiN-coated and uncoated aluminum chambers have been tested. Electron and positron beams of 2.1, 4.0 and 5.3 GeV with a variety of bunch populations and spacings in steps of 4 and 14 ns have been used. Here we report on results from the ECLOUD modeling code which highlight the sensitivity of these measurements to the physical phenomena determining cloud buildup such as the photoelectron production azimuthal and energy distributions, and the secondary yield parameters including the true secondary, re-diffused, and elastic yield values.Comment: Presented at ECLOUD'12: Joint INFN-CERN-EuCARD-AccNet Workshop on Electron-Cloud Effects, La Biodola, Isola d'Elba, Italy, 5-9 June 2012; CERN-2013-002, pp. 241-25

Modeling of activated carbon and coal gasification char absorbents in single-solute and bisolute systems

A mathematical model of fixed-bed adsorption was used to predict the bed response to a sustained step change in influent concentration. The model was employed to compare the performance of different adsorbents in the removal of organics from water and to analyze factors that affect desorption owing to a decrease in influent concentration and to competitive adsorption. Model equations, which considered that film transfer and surface diffusion controlled the adsorption rate, were solved with the technique of orthogonal collocation. Three species, 3,5-dimethylphenol (DMP), 3,5-dichlorophenol (DCP) and rhodamine 6G (R6G), were the single solutes studied, and the two phenols were also examined as a mixture. Four activated carbons and a coal gasification char were the adsorbents studied. The model was used to compare the adsorbents in the removal of DMP, R6G and the bisolute mixtures and equilibrium capacity was found to have a greater influence than kinetics on fixed-bed performance. It was observed that, under conditions approximating a drinking water plant, the time during which the effluent concentration of a desorbed species was higher than the influent concentration was significant (on the order of weeks) whether a reduced influent concentration or competition was responsible for the desorption.U.S. Department of the InteriorU.S. Geological SurveyOpe

Task Encoding across the Multiple Demand Cortex Is Consistent with a Frontoparietal and Cingulo-Opercular Dual Networks Distinction.

UNLABELLED: Multiple-demand (MD) regions of the human brain show coactivation during many different kinds of task performance. Previous work based on resting-state functional magnetic resonance imaging (fMRI) has shown that MD regions may be divided into two closely coupled subnetworks centered around the lateral frontoparietal (FP) and cingulo-opercular cortex. Here, we used on-task fMRI to test whether this division is apparent during the performance of an executive task. Furthermore, we investigated whether there is a difference in the encoding of task between the two subnetworks. Using connectivity methods, we found that activity across the entire MD cortex is correlated during task performance. Meanwhile, however, there was significantly stronger connectivity within each of the subnetworks than between them. Using multivoxel pattern analysis, we also found that, although we were able to decode task-relevant information from all regions of the MD cortex, classification accuracy scores were significantly higher in the FP subnetwork. These results suggest a nested picture with MD regions as a whole showing coactivation and broad rule representation, but with significant functional distinctions between component subnetworks. SIGNIFICANCE STATEMENT: Multiple-demand (MD) regions of frontal and parietal cortex appear essential for the orchestration of goal-directed behavior and problem solving. Understanding the relative specialization of regions within the MD cortex is crucial to understanding how we can coordinate and execute complex action plans. By examining functional connectivity during task performance, we extend previous findings suggesting that the MD cortex can be divided into two subnetworks centered around the frontoparietal (FP) and cingulo-opercular (CO) cortex. Furthermore, using multivoxel pattern analysis, we show that, compared with the CO subnetwork, the FP subnetwork manifests more differentiated coding of specific task events

Groundwater Management: The Movement Toward Local, Communityh-Based, Voluntary Programs

Worldwide, groundwater aquifers are under stress. Conflicts abound.The U.S. Geological Survey (USGS) reports this to be true in the United States as well. For decades, American state governments facing the problem have attempted through legislation4 and administrative action5 to reduce the rate of depletion of groundwater aquifers. Some areas in Kansas have been closed down completely to the issuance of new groundwater pumping permits. The judiciary has been active as well. A court or administrative agency may force reduced pumping by some pumpers in a defined aquifer in an attempt to slow down groundwater mining. Or, a court may order a single well owner to reduce or curtail pumping altogether because of impairment of another well. This article treats various methods in which this problem is being addressed in the United States and the ways they have evolved over the last few decades. Water professionals commonly call the general approach to the problem "groundwater management." Some dictionary definitions of "manage" include the following: "handle or address with a degree of skill" and "treat with care,"' "control .. .something,"" "succeed in accomplishing,' and "control the use or exploitation of."' Any person's answer to the question of whether any of these various methods are working "may depend ... in part on the person's background, biases, perspective, and perhaps even present employment.

Bactericidal – Bacteriostatic Foam Filters for Air Treatment

A highly loaded porous polyimide (PI) foam type air filter has been fabricated by incorporating antimicrobial active metals to prevent microbial growth and kill microbes, and so to provide health benefits for people in enclosed spaces. PI foams containing antibacterial agents, such as PCu80 (PI (20 wt %)/copper (80 wt %)), PNi80 (PI (20 wt %)/nickel (80 wt %)), and copper-nickel composites, were synthesized and tested against model bacterium, Erwinia carotovora (Gram negative) to determine the antibacterial efficacy of the air filter. Scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) confirmed the distribution of copper and nickel throughout PCu80 and PNi80, where concentrations between 70% and 75% were detected. The copper: nickel ratio was consistent throughout the foam for PCu64Ni16 (PI (20 wt %)/copper (64 wt %)/nickel (16 wt %)). PCu80 displayed a high log reduction value (LRV) of 99.996% and, thus, exhibited a bactericidal effect. PNi80 displayed a lower LRV of 99.4%. However, a higher LRV value was observed compared to the control, 95.5% (PI foam without antibacterial agent), and thus, demonstrated a bacteriostatic effect. PCu64Ni16 exhibited and sustained exceptional microbe removal efficiencies of 99.9997% for 24 h at high humidity levels and demonstrated the highest zone of inhibition (ZOI) value of 33.90 ± 0.16 mm compared to PCu80 (27.5 ± 1.1 mm). Nickel strongly inhibited the proliferation of bacteria, while copper destroyed the bacteria on the foam filters. Therefore, such functionalized filters can potentially overcome the inherent limitation in conventional filters and imply their superiority for controlling indoor air quality.</p

Method and apparatus for destroying organic compounds in fluid

An apparatus for the photocatalytic oxidation of organic contaminants in fluid includes a reactor and a photocatalyst affixed to support material. Preferably, the outer wall of the reactor is constructed of material transmissive of ultraviolet radiation. The support material preferably is transmissive of ultraviolet radiation. The support material can also be an adsorbent material. Also, a method for photocatalytic oxidation of organic contaminants in fluid. Also, a method for preparation of a supported photocatalyst. Also, a supported photocatalyst adapted for the photocatalytic oxidation of organic contaminants in fluid. Also, a method for preparing a photocatalyst adapted for the photocatalytic oxidation of organic contaminants in fluid.https://digitalcommons.mtu.edu/patents/1071/thumbnail.jp

Regeneration of adsorbents using advanced oxidation

The present invention is a method of purifying fluid having organic material. The method comprises two operational steps. The first step includes passing the fluid through an adsorbent such that the organic material is substantially adsorbed by the adsorbent and the fluid is substantially purified. The second step includes destroying the adsorbed organic material on the adsorbent and regenerating the adsorbent in a form substantially free of adsorbed organic material.https://digitalcommons.mtu.edu/patents/1115/thumbnail.jp