The Landau Distribution for Charged Particles Traversing Thin Films

The Landau distribution as well as its first and second momenta are well suited for describing the energy loss of charged particles traversing a thin layer of matter. At present, just rational approximations and asymptotic expressions for these functions were obtained. In this paper we present a direct calculation of the integral representation of these functions obtaining perturbative and nonperturvative solutions expressed in terms of fast convergent series. We also provide a simple numerical algorithm which allows to control speed and precision of the results. The testing runs have provided, in reasonable computing times, correct results up to 13-14 significant digits on the density and distribution functions and 9-10 on the first and second momenta. If necessary, this accuracy could be improved by adding more coefficients to the algorithm.Comment: 29 pages, 4 Table

AOC reduction by biologically active filtration

L'objectif de ce projet était de fournir un guide pratique de l'application des techniques de traitement biologique aux opérations de traitement actuel des eaux. Les études furent centrées sur la production d'une eau biologiquement équilibrée, sur la stabilité (l'équilibre) des désinfectants, et sur la formation moins importante de sous-produits désinfectants. Notamment, l'étude a montré que les procéssus biologiques peuvent satisfaire les besoins de la pratique aussi bien que les exigences régulatrices de l'industrie de l'eau.Le système de surveillance et de contrôle des niveaux du carbone organique assimilable (COA) des éffluents de la "Swimming River Treatment Plant" a montré que des données >100 µq/L pourraient expliquer d'une part, l'apparition des bactéries conformes dans le système de distribution et d'autre part la transgression potentielle des règlements récemment révisés de la "Limite Maximum de Contaminants de Coliformes" des Etats-Unis. L'optimum du traitement a été établi à 100 µg/L could be related to the occurrence of coliform bacteria in the distribution system. A treatment goal of <100 µg/L was established for biologically active treatment processes. Granular activated carbon (GAC) filters were found to support a larger bacterial population, and thus, provide better biological removal of AOC and total organic carton (TOC). All biologically active filters showed good performance relative to effluent turbidity levels, and headloss development. Preozonation of raw water increased AOC levels an average of 2.3 fold, and always increased filter effluent AOC levels relative to nonozonated water. Application of free chlorine to GAC filters did not inhibit biological activity. Application of chloramines to GAC filters showed a slight inhibitory affect relative to free chlorine. Effluent AOC levels averaged 82 µg/L at an EBCT of 5 min, and decreased to an average of 57 µg/L at 20 min EBCT. EBCT did affect TOC removals, with efficiencies averaging 29, 33, 42, and 51 % removal at EBCTs of 5, 10, 15 and 20 min, respectively. Trihalomethane formation potentials (THMFP) were related to TOC levels. Processes Chat decreased TOC levels also decreased THMFP. A preozonated GAC/sand filter (EBCT 10 min) achieved an annual average 54 % removal of THMFP precursors. Post disinfection of biologically treated effluents reduced HPC bacterial counts by 2-2.5log10. Post chlorination or chloramination of prechlorinated GAC/sand effluents resulted in a 20 %, or a 44 % (respectively) increase in AOC levels. Post disinfection of preozonated water resulted in small (<8%) AOC increases. Despite increases in AOC levels, prechlorinated water had lower AOC levels than preozonated water, even after post disinfection

2006 progress report on acoustic and visual monitoring for cetaceans along the outer Washington Coast

An acoustic and visual monitoring effort for cetaceans was initiated within the boundaries of the proposed expansion area for the Quinault Underwater Tracking Range in July 2004. Acoustic data collection consisted of recordings at a site on the continental shelf to the west of Cape Elizabeth and another in deep water within Quinault Canyon. An analysis plan for acoustic data is included. Results for 32 visual surveys are presented as tables and charts for pinnipeds, dolphins, porpoises, and whales. Time series of vocalizations detected in acoustic recordings are presented for killer whales, white-sided dolphins, Risso's dolphins, unclassified dolphins, humpback whales, and sperm whales. Visual sightings show clear differences in locations, reflecting preferred habitats as well as providing information on seasonal occurrence of some species. Preliminary comparison of acoustic and visual data sets reveals interesting patterns. For example, humpback whales are most commonly seen in summer and fall throughout the visual survey region, yet song and feeding calls of these whales are heard almost exclusively in fall and winter. First steps in the development of a predictive habitat model for cetaceans are described. Continued visual and acoustic data collection is recommended. Brief summaries of papers given at four scientific meetings are included

Infrared Spectroscopic Study of Vibrational Modes across the Orthorhombic Tetragonal Phase Transition in Methylammonium Lead Halide Single Crystals

Single crystals of the methylammonium MA lead halides MAPbI3, MAPbBr3, and MAPbCl3 have been investigated using infrared spectroscopy with the aim of analyzing structural and dynamical aspects of processes that enable the ordering of the MA molecule in the orthorhombic crystal structure of these hybrid perovskites. Our temperature dependent studies were focused on the analysis of the CH NH rocking, C N stretching, and CH NH bending modes of the MA molecule in the 800 1750 cm 1 frequency range. They deliver a direct comparison of the behaviors of the three halides on crossing the orthorhombic tetragonal phase transition in MA lead halide single crystals. Drastic changes of all vibrational modes close to the phase transition were clearly observed. Additional spectral features that were not discussed previously are pointed out. The transformation of the two dimensional orthorhombic hydrogen bond layers into a more three dimensional arrangement in the tetragonal phase seems to be an important feature providing deeper insights into the mechanisms that lead to a free rotating MA molecule in the inorganic host structure. The change of the molecule site symmetry in the tetragonal crystal structure seems to be an important feature of the orthorhombic tetragonal phase transition. For low temperatures, it can be stated that the iodide is stronger influenced by hydrogen bonding than the bromide and the chlorid

Corrosion Control in Industry

The economic development of any region, state or country, depends not only on its natural reâ sources and productive activities, but also on the infrastructure that account for the exploitaâ tion, processing and marketing of goods. Irrigation systems, roads, bridges, airports, maritime, land and air transport, school buildings, offices and housing, industrial installations are affectâ ed by corrosion and therefore susceptible to deterioration and degradation processes

The use of anomalous x ray diffraction as a tool for the analysis of compound semiconductors

We provide a review about the current and previous use of anomalous diffraction of x rays in the analysis of compound semiconductors. Among the large number of available techniques, those that have been used in successful experiments on this class of compounds are identified. An exhaustive overview of the compound semiconductor systems that have been studied successfully is provided and the kind of results derived from experiments is discusse

Uncovering cation disorder in ternary Zn1+xGe1−x(N1−xOx)2 and its effect on the optoelectronic properties

Ternary nitride materials, such as ZnGeN2, have been considered as hopeful optoelectronic materials with an emphasis on sustainability. Their nature as ternary materials has been ground to speculation of cation order/disorder as a mechanism to tune their bandgap. We herein studied the model system Zn1+xGe1−x(N1−xOx)2 including oxygen – which is often a contaminant in nitride materials – using a combination of X-ray and neutron diffraction combined with elemental analyses to provide direct experimental evidence for the existence of cation swapping in this class of materials. In addition, we combine our results with UV-VIS spectroscopy to highlight the influence of disorder on the optical bandgap

Movements and spatial use of odontocetes in the western main Hawaiian Islands: results from satellite-tagging and photo-identification off Kaua‘i and Ni‘ihau in July/August 2011

Although considerable information is available on residency patterns and spatial use of odontocetes in the eastern half of the Hawai‘i Range Complex (HRC), much less is known about odontocetes in the western half of the HRC. In the second year of a three-year effort in the western main Hawaiian Islands we undertook surveys off Kaua‘i and Ni‘ihau in July/August 2011, to examine spatial use and residency patterns using satellite tags, to provide visual verification of acoustically-detected odontocetes on the Pacific Missile Range Facility (PMRF), and to obtain individual identification photographs and biopsy samples for assessment of population identity and structure. During 18 days of field effort we covered 1,972 km of trackline and had 65 encounters with five species of odontocetes. Twenty-four of the encounters, of three species, were cued by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system, thus providing species verifications for future use of the M3R system on the PMRF range. During the 65 encounters we obtained 22,645 photos for individual and species identification, and collected 48 biopsy samples for genetic analyses. One encounter with a group of four killer whales was only the second encounter with this species in 12 years of directed field surveys in Hawaiian waters. Photos from that encounter were compared to our photo-identification catalog but no matches were found, further suggesting that there is no population of this species resident to the Hawaiian Islands. There were three encounters with a lone pantropical spotted dolphin, each time in association with a group of spinner dolphins. Photos of this individual matched to a spotted dolphin identified off Kaua‘i in 2004 and in 2005, both times with spinner dolphins, suggesting this individual may be part of a long-term association with spinner dolphins. Four satellite tags were deployed; three on rough-toothed dolphins and one on a bottlenose dolphin. These are the first tag deployments on either species in Hawaiian waters and the first deployments of satellite tags on free-ranging rough-toothed dolphins anywhere in the world. Rough-toothed dolphin tag data were obtained over periods from 7.6 to 18.5 days. Over these periods the three rough-toothed dolphins moved cumulative horizontal distances ranging from 573 to 1,295 km, yet remained an average distance from the tagging locations of from 10.4 to 13.9 km. Median depths used by the three rough-toothed dolphins ranged from 816 to 1,107 m, with median distance from shore ranging from 11.6 to 12.2 km. Two of the three individuals had been previously photo-identified off Kaua‘i (in 2007 or 2008), and all link by association with the resident population from Kaua‘i and Ni‘ihau. Movement and habitat use data were obtained over a 34-day period for the satellite-tagged bottlenose dolphin. During this time the individual remained associated with the island of Kaua‘i using waters with a median depth of 82 m. Although this individual had not been previously photo-identified, others from the group it was in had been previously documented off Kaua‘i and/or Ni‘ihau in 2003-2005, suggesting it is part of the island-resident population. Overall these efforts provide the first unbiased movement and habitat use data for both species in Hawaiian waters.Grant No. N00244-10-1-004