RECUPERACIÓN DE PERCLORETILENO EN INDUCALSA

A recovery system for perchlorine ethylene from hazardous liquid waste (Ministry Agreement 026 MAE) which stems from shoe making polyurethane sole washing has been designed (Brito H. / Rodríguez B., 2014). Such waste is directly disposed into the environment, causing losses in flora and fauna (GUARIN, O. / RUEDA, G. / PEREZ, H. 2010). Besides contributing with environmental liabilities, the recovered perchlorine ethylene complies the requirements of the DIRSA safety card, because of what it is reutilized in the manufacture process, which contributes to the decrease of production costs and the conservation of the ecosystem. This hazardous waste should be delivered to an environmental manager before paying for its transportation and final disposal (90 USD per kg of waste). For this reason, INDUCALSA along with ESPOCH researchers carried out a scaling of the recovery system by working with 20 samples of perchlorine ethylene – silicone during a lapse of four weeks. An initial characterization was followed by in – lab recovery to measure the variables (temperature, time, input and output flow) with whom the process was scaled for 45,73 Kg/h of waste. The pH, density, viscosity and IR spectrum of the obtained product were analyzed. They showed the purity of the solvent (Disolventes Reunidas, S.A., 2003), which is acceptable because of its high economic value in the market as well as the contribution to the change of the productive matrix in Ecuador (SENPLADES, 2012)

Using a Floating-Gate MOS Transistor as a Transducer in a MEMS Gas Sensing System

Floating-gate MOS transistors have been widely used in diverse analog and digital applications. One of these is as a charge sensitive device in sensors for pH measurement in solutions or using gates with metals like Pd or Pt for hydrogen sensing. Efforts are being made to monolithically integrate sensors together with controlling and signal processing electronics using standard technologies. This can be achieved with the demonstrated compatibility between available CMOS technology and MEMS technology. In this paper an in-depth analysis is done regarding the reliability of floating-gate MOS transistors when charge produced by a chemical reaction between metallic oxide thin films with either reducing or oxidizing gases is present. These chemical reactions need temperatures around 200 °C or higher to take place, so thermal insulation of the sensing area must be assured for appropriate operation of the electronics at room temperature. The operation principle of the proposal here presented is confirmed by connecting the gate of a conventional MOS transistor in series with a Fe2O3 layer. It is shown that an electrochemical potential is present on the ferrite layer when reacting with propane

PARASITOFAUNA DE PARANTHIAS COLONUS (VALENCIENNES, 1846) EN EL SARGENTO, BAJA CALIFORNIA SUR, MÉXICO

Paranthias colonus(Valenciennes, 1846) is used as fish bait replacing first class fish that have been overfished in the Gulf of California. Due to its recent commercial importance, the parasite fauna of P. colonusfrom of El Sargento, Baja California Sur, Mexico is characterized to define its role in the life cycle of its parasites. 30 fishes were fixed in 4% formaldehyde for later examination. Helminths and copepods were treated with conventional techniques specific to each kind of parasite. P. colonushad 100% prevalence and 46.5 mean intensity of parasites. Adults of Pseudorhabdosynochus sp., Prodistomum orientalis, Brachyphallus sp., Lecithochirium sp., Spinitectus sp., Caligus sp., Pandaridae, and Hatschekia sp. and larevae of Tetragonocephalidae, Scolex pleuronectis and Anisakis sp. were found. There was evidence of host specificity of Pseudorhabdosynochussp. and Hatschekiasp. by serranid fish. P. orientalisis reported for the second time. Hemiuridae are generalists so Paranthiashas added to this host range. The presence of the metacestodes S. pleuronectisand Tetragonocephalidae indicates their role in Paranthiasas intermediate or paratenic hosts because they are found in adult elasmobranches. Anisakissp. and Caligussp. are of wide geographic distribution and host range. Anisakissp. is the only worm that poses a potential danger to public health because it causes anisakidosis. Members of the family Pandaridae are almost exclusive parasites in elasmobranchians and Paranthiasis widely spread in its hosts. This work reports the first world record of hosts and localities of the studied materials.Paranthias colonus (Valenciennes, 1846) es un pez usado como carnada que ha sustituido a los peces de primera clase que se han sobreexplotado en el Golfo de California. Debido a su reciente importancia comercial en este trabajo se caracterizó la parasitofauna de P. colonusen la localidad de El Sargento, Baja California Sur, México, para definir el papel que tiene en el ciclo biológico de sus parásitos. Se adquirieron 30 ejemplares se fijaron en formaldehído al 4% para su posterior revisión. Los helmintos y copépodos se trataron con las técnicas convencionales propias de cada clase de parásito. Se tuvo un 100% de prevalencia y 46,5 de intensidad media de parasitismo general. Pseudorhabdosynochus sp., Prodistomum orientalis, Brachyphallus sp., Lecithochirium sp., Spinitectus sp., Caligus sp., Pandaridae y Hatschekia sp. son adultos y Tetragonocephalidae, Scolex pleuronectis y Anisakis sp. son formas larvarias. Se evidencia la especificidad hospedatoria de Pseudorhabdosynochus sp. y Hatschekia sp. por peces Serránidos. P. orientalisen el presente trabajo representa el segundo registro. Los hemiúridos son generalistas por lo que Paranthiasse agrega a este rango de hospederos. La presencia de metacéstodos de Tetragonocephalidae y S. pleuronectisen Paranthiasindica su papel como hospedero intermediario o paraténico, debido a que en etapa adulta se encuentran en elasmobranquios. Anisakis sp. y Caligus sp. son de amplia distribución geográfica y rango de hospederos. Anisakissp. es el único helminto que representa un peligro potencial para la salud pública por ser causante de Anisakidosis. Los miembros de la familia Pandaridae son parásitos casi exclusivos de elasmobranquios y Paranthiasdiversifica su rango hospedatorio. Finalmente, la parasitofauna del hospedero y localidad de este trabajo representan el primer registro a nivel mundial

Electron energy loss and induced photon emission in photonic crystals

The interaction of a fast electron with a photonic crystal is investigated by solving the Maxwell equations exactly for the external field provided by the electron in the presence of the crystal. The energy loss is obtained from the retarding force exerted on the electron by the induced electric field. The features of the energy loss spectra are shown to be related to the photonic band structure of the crystal. Two different regimes are discussed: for small lattice constants $a$ relative to the wavelength of the associated electron excitations $\lambda$, an effective medium theory can be used to describe the material; however, for $a\sim\lambda$ the photonic band structure plays an important role. Special attention is paid to the frequency gap regions in the latter case.Comment: 12 pages, 7 figure

The Palomar Testbed Interferometer Calibrator Catalog

The Palomar Testbed Interferometer (PTI) archive of observations between 1998 and 2005 is examined for objects appropriate for calibration of optical long-baseline interferometer observations - stars that are predictably point-like and single. Approximately 1,400 nights of data on 1,800 objects were examined for this investigation. We compare those observations to an intensively studied object that is a suitable calibrator, HD217014, and statistically compare each candidate calibrator to that object by computing both a Mahalanobis distance and a Principal Component Analysis. Our hypothesis is that the frequency distribution of visibility data associated with calibrator stars differs from non-calibrator stars such as binary stars. Spectroscopic binaries resolved by PTI, objects known to be unsuitable for calibrator use, are similarly tested to establish detection limits of this approach. From this investigation, we find more than 350 observed stars suitable for use as calibrators (with an additional $\approx 140$ being rejected), corresponding to $\gtrsim 95$ sky coverage for PTI. This approach is noteworthy in that it rigorously establishes calibration sources through a traceable, empirical methodology, leveraging the predictions of spectral energy distribution modeling but also verifying it with the rich body of PTI's on-sky observations.Comment: 100 pages, 7 figures, 7 tables; to appear in the May 2008ApJS, v176n

Focal and non-focal epilepsy localization: a review

The focal and non-focal epilepsy is seen to be a chronic neurological brain disorder, which has affected ≈ 60 million people in the world. Hence, an early detection of the focal epileptic seizures can be carried out using the EEG signals, which act as a helpful tool for early diagnosis of epilepsy. Several EEG-based approaches have been proposed and developed to understand the underlying characteristics of the epileptic seizures. Despite the fact that the early results were positive, the proposed techniques cannot generate reproducible results and lack a statistical validation, which has led to doubts regarding the presence of the pre-ictal state. Various methodical and algorithmic studies have indicated that the transition to an ictal state is not a random process, and the build-up can lead to epileptic seizures. This study reviews many recently-proposed algorithms for detecting the focal epileptic seizures. Generally, the techniques developed for detecting the epileptic seizures were based on tensors, entropy, empirical mode decomposition, wavelet transform and dynamic analysis. The existing algorithms were compared and the need for implementing a practical and reliable new algorithm is highlighted. The research regarding the epileptic seizure detection research is more focused on the development of precise and non-invasive techniques for rapid and reliable diagnosis. Finally, the researchers noted that all the methods that were developed for epileptic seizure detection lacks standardization, which hinders the homogeneous comparison of the detector performance

The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.Comment: 15 pages, 4 figures, version to be published in PR

VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro