Human impact on the quality of the surface waters of the Claromecó Creek mid-basin, Argentina

Los cursos fluviales de la cuenca media del Arroyo Claromecó en su recorrido atraviesan la localidad de Tres Arroyos con más de 59 000 habitantes. El objetivo de este trabajo es analizar la calidad de agua de los cursos superficiales de la cuenca media para estudiar el impacto humano en este sector del sistema fluvial. Se seleccionaron 5 estaciones de muestreo para la concentración de metales pesados en el sedimento de los cauces y en cuatro de ellas se obtuvieron valores de nutrientes en agua. Estas mediciones se realizaron durante agosto del 2007 y se repitieron durante agosto del 2009. La determinación de nutrientes se realizó mediante el uso de un autoanalizador Technicon AutoAnalyzer II secuencial y por espectrofotometría se analizó la Materia Orgánica Particulada. Los valores de nutrientes hallados presentaron mayor variabilidad entre los años 2007 y 2009. Los máximos se observaron durante el primer año de medición, mientras que el máximo de amonio se observó en el colector principal para el año 2009. Se detectaron variables superiores a los niveles guía de protección de la vida acuática, como el caso de nitratos y fosfatos en el Arroyo Claromecó, tendencia que se mantuvo en casi todos los parámetros químicos, lo que se correspondería con descargas cloacales y secundariamente industriales de las plantas procesadoras por las que atraviesa este curso fluvial en el área urbana y periurbana de la localidad de Tres Arroyos. Los sedimentos fluviales analizados presentaron valores de metales pesados bajos-intermedios. El análisis de las variables físicas y químicas del agua reflejan para los afluentes del Arroyo Claromecó las características de sustrato y la influencia del uso agrícola ganadero circundante. El curso principal presenta un predominio del uso urbano e industrial a partir del mayor aporte de nutrientes a sus aguas, provenientes de descargas domésticas directas sin tratamiento.The creeks of the middle basin of the Arroyo Claromecó cross the town of Tres Arroyos with over 59 000 inhabitants, where an industrial plant and a wastewater treatment plant city is located. The aim of this paper is to analyze the quality of surface water courses of the basin to study human impact on this sector of the river system. We selected 5 sampling stations for the concentration of heavy metals in the sediment of rivers. In four of them values of nutrients in the water were obtained. These measurements were conducted during August 2007 and repeated in August 2009. The determination of nutrients was performed using a sequential Technicon Autoanalyzer II and the Particulate OrganicMatter was analyzed by spectrophotometry. The nutrient values showed greater variability between 2007 and 2009. The maxima were observed during the first year of measurement, while the maximum of ammonium was observed in the main sewer in 2009. Variables were detected above guideline levels for the protection of aquatic life, as the case of nitrates and phosphates in the Arroyo Claromecó. This trend was maintained for almost all the chemical parameters, which would correspond to secondary sewage and industrial discharges from plants processing by the river that runs through this course in peri-urban areas of the town of Tres Arroyos. The analyzed river sediments showed low to intermediate values of heavy metals. For the tributaries of the Arroyo Claromecó, the analysis of the physical and chemical variables of water reflects substrate characteristics and the influence of surrounding agricultural livestock. The main course presents a predominance of urban and industrial use from the increased supply of nutrients to the water, that come directly from untreated domestic dischargesFil: Carbone, Maria Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: García Martínez, B.. Universidad de Sevilla. Facultad de Geografía e Historia; EspañaFil: Marcovecchio, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Piccolo, Maria Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); ArgentinaFil: Perillo, Gerardo Miguel E.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Instituto Argentino de Oceanografía (i); Argentin

Impedance measurements and simulations on the TCT and TDI LHC collimators

The LHC collimation system is a critical element for the safe operation of the LHC machine and it is subject to continuous performance monitoring, hardware upgrade and optimization. In this work we will address the impact on impedance of the upgrades performed on the injection protection target dump (TDI), where the absorber material has been changed to mitigate the device heating observed in machine operation, and on selected secondary (TCS) and tertiary (TCT) collimators, where beam position monitors (BPM) have been embedded for faster jaw alignment. Con- cerning the TDI, we will present the RF measurements per- formed before and after the upgrade, comparing the result to heating and tune shift beam measurements. For the TCTs, we will study how the higher order modes (HOM) intro- duced by the BPM addition have been cured by means of ferrite placement in the device. The impedance mitigation campaign has been supported by RF measurements whose results are in good agreement with GdfidL and CST simula- tions. The presence of undamped low frequency modes is proved not to be detrimental to the safe LHC operation

Design of a high power production target for the Beam Dump Facility at CERN

The Beam Dump Facility (BDF) project is a proposed general-purpose facility at CERN, dedicated to beam dump and fixed target experiments. In its initial phase, the facility is foreseen to be exploited by the Search for Hidden Particles (SHiP) experiment. Physics requirements call for a pulsed 400 GeV/c proton beam as well as the highest possible number of protons on target (POT) each year of operation, in order to search for feebly interacting particles. The target/dump assembly lies at the heart of the facility, with the aim of safely absorbing the full high intensity Super Proton Synchrotron (SPS) beam, while maximizing the production of charmed and beauty mesons. High-Z materials are required for the target/dump, in order to have the shortest possible absorber and reduce muon background for the downstream experiment. The high average power deposited on target (305 kW) creates a challenge for heat removal. During the BDF facility Comprehensive Design Study (CDS), launched by CERN in 2016, extensive studies have been carried out in order to define and assess the target assembly design. These studies are described in the present contribution, which details the proposed design of the BDF production target, as well as the material selection process and the optimization of the target configuration and beam dilution. One of the specific challenges and novelty of this work is the need to consider new target materials, such as a molybdenum alloy (TZM) as core absorbing material and Ta2.5W as cladding. Thermo-structural and fluid dynamics calculations have been performed to evaluate the reliability of the target and its cooling system under beam operation. In the framework of the target comprehensive design, a preliminary mechanical design of the full target assembly has also been carried out, assessing the feasibility of the whole target system.Comment: 17 pages, 18 figure

Searches for Stable Strangelets in Ordinary Matter: Overview and a Recent Example

Our knowledge on the possible existence in nature of stable exotic particles depends solely upon experimental observation. Guided by this general principle and motivated by theoretical hypotheses on the existence of stable particles of strange quark matter, a variety of experimental searches have been performed. We provide an introduction to the theoretical hypotheses, an overview of the past searches, and a more detailed description of a recent search for helium-like strangelets in the Earth's atmosphere using a sensitive laser spectroscopy method

Peace-and-Order Power of an Ohio Municipal Corporation

Ohio Const. Art. XVIII, Sec. 3 endows the municipalities with those powers of local self-government .. .as are not in con-flict with general laws. The courts have unanimously interpreted the general laws to be those laws which have been enactedy the General Assembly. A question of conflict arises (1) wherehe state and the municipality each have prohibited the same act and where each seeks to enforce, independent of the other; (2) where the municipality seeks to prohibit that which the state permits, or seeks to permit that which the state prohibits;and (3) where the municipality provides a penalty in excess of that authorized by the state

Peace-and-Order Power of an Ohio Municipal Corporation

Ohio Const. Art. XVIII, Sec. 3 endows the municipalities with those powers of local self-government .. .as are not in con-flict with general laws. The courts have unanimously interpreted the general laws to be those laws which have been enactedy the General Assembly. A question of conflict arises (1) wherehe state and the municipality each have prohibited the same act and where each seeks to enforce, independent of the other; (2) where the municipality seeks to prohibit that which the state permits, or seeks to permit that which the state prohibits;and (3) where the municipality provides a penalty in excess of that authorized by the state

Mechanism of retinoic acid-induced transcription: histone code, DNA oxidation and formation of chromatin loops

Histone methylation changes and formation of chro- matin loops involving enhancers, promoters and 3′ end regions of genes have been variously associ- ated with active transcription in eukaryotes. We have studied the effect of activation of the retinoic A re- ceptor, at the RARE–promoter chromatin of CASP9 and CYP26A1 genes, 15 and 45 min following RA ex- posure, and we found that histone H3 lysines 4 and 9 are demethylated by the lysine-specific demethylase, LSD1 and by the JMJ-domain containing demethy- lase, D2A. The action of the oxidase (LSD1) and a dioxygenase (JMJD2A) in the presence of Fe++ elic- its an oxidation wave that locally modifies the DNA and recruits the enzymes involved in base and nu- cleotide excision repair (BER and NER). These events are essential for the formation of chromatin loop(s) that juxtapose the RARE element with the 5′ tran- scription start site and the 3′ end of the genes. The RARE bound-receptor governs the 5′ and 3′ end se- lection and directs the productive transcription cycle of RNA polymerase. These data mechanistically link chromatin loops, histone methylation changes and localized DNA repair with transcription

Color plasma oscillation in strangelets

The dispersion relation and damping rate of longitudinal color plasmons in finite strange quark matter (strangelets) are evaluated in the limits of weak coupling, low temperature, and long wavelength. The property of the QCD vacuum surrounding a strangelet makes the frequency of the plasmons nearly the same as the color plasma frequency of bulk matter. The plasmons are damped by their coupling with individual excitations of particle-hole pairs of quarks, of which the energy levels are discretized by the boundary. For strangelets of macroscopic size, the lifetime of the plasmons is found to be proportional to the size, as in the case of the usual plasma oscillations in metal nanoparticles.Comment: 9 pages (REVTeX), 2 Postscript figures, to be published in Phys. Rev.

Exclusion limits on the WIMP-nucleon cross-section from the Cryogenic Dark Matter Search

The Cryogenic Dark Matter Search (CDMS) employs low-temperature Ge and Si detectors to search for Weakly Interacting Massive Particles (WIMPs) via their elastic-scattering interactions with nuclei while discriminating against interactions of background particles. For recoil energies above 10 keV, events due to background photons are rejected with >99.9% efficiency, and surface events are rejected with >95% efficiency. The estimate of the background due to neutrons is based primarily on the observation of multiple-scatter events that should all be neutrons. Data selection is determined primarily by examining calibration data and vetoed events. Resulting efficiencies should be accurate to about 10%. Results of CDMS data from 1998 and 1999 with a relaxed fiducial-volume cut (resulting in 15.8 kg-days exposure on Ge) are consistent with an earlier analysis with a more restrictive fiducial-volume cut. Twenty-three WIMP candidate events are observed, but these events are consistent with a background from neutrons in all ways tested. Resulting limits on the spin-independent WIMP-nucleon elastic-scattering cross-section exclude unexplored parameter space for WIMPs with masses between 10-70 GeV c^{-2}. These limits border, but do not exclude, parameter space allowed by supersymmetry models and accelerator constraints. Results are compatible with some regions reported as allowed at 3-sigma by the annual-modulation measurement of the DAMA collaboration. However, under the assumptions of standard WIMP interactions and a standard halo, the results are incompatible with the DAMA most likely value at >99.9% CL, and are incompatible with the model-independent annual-modulation signal of DAMA at 99.99% CL in the asymptotic limit.Comment: 40 pages, 49 figures (4 in color), submitted to Phys. Rev. D; v.2:clarified conclusions, added content and references based on referee's and readers' comments; v.3: clarified introductory sections, added figure based on referee's comment

New Results from the Cryogenic Dark Matter Search Experiment

Using improved Ge and Si detectors, better neutron shielding, and increased counting time, the Cryogenic Dark Matter Search (CDMS) experiment has obtained stricter limits on the cross section of weakly interacting massive particles (WIMPs) elastically scattering from nuclei. Increased discrimination against electromagnetic backgrounds and reduction of neutron flux confirm WIMP-candidate events previously detected by CDMS were consistent with neutrons and give limits on spin-independent WIMP interactions which are >2X lower than previous CDMS results for high WIMP mass, and which exclude new parameter space for WIMPs with mass between 8-20 GeV/c^2.Comment: 4 pages, 4 figure