342 research outputs found

    An investigation into the enhancement of fingermarks in blood on paper with genipin and lawsone

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    The abilities of two natural products, genipin and lawsone, to enhance blood contaminated fingermarks on papers of various porosities and colour were investigated and compared to the routinely used amino acid reagents, ninhydrin and 1,8-diazafluoren-9-one (DFO).Fingermarks in blood were deposited as a split depletion series on various paper types and colours for ageing periods of 6 weeks, 4 weeks, 2 weeks and 1 week before enhancement. The developed marks were observed under different lighting conditions, recorded and graded by way of attributing quantitative data to each series.Results indicated that while genipin showed some potential as a reagent for the enhancement of latent fingermarks, it displayed no suitability for the enhancement of fingermarks in blood on paper. Lawsone also failed to successfully enhance either type of fingermark. Upon comparison of the results with those of ninhydrin and DFO it was found that ninhydrin displayed the highest success rate of development of these marks

    Interdisciplinary assessment of the skate fishery in the Gulf of Alaska

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    Thesis (Ph.D.) University of Alaska Fairbanks, 2017Skates are common bottom-dwelling fishes and valuable non-target species in Gulf of Alaska fisheries. Although there is little demand for skates in the United States, markets in Europe and Asia are fueling desires for additional fishing opportunities on skates in Alaska. Management agencies, however, have been hesitant to allow increased harvests due to the lack of information on the ecology and population dynamics of skates, and the bioeconomics of skate fisheries. Specifically focusing on the two most commonly landedskate species in the Gulf of Alaska (GOA), the big skate (Beringraja binoculata) and the longnose skate (Raja rhina), I conducted an interdisciplinary project to address these knowledge gaps. First, I advanced our understanding of the movement patterns and habitat use of skates by satellite tagging big skates in the GOA. The results show that big skates can, and likely frequently do, travel long distances, cross management boundaries within the GOA, and spend more time in deeper waters than previously thought. Second, I used the insights from the movement study to develop the first stock assessment models for skates in the GOA. This represents an important improvement in modeling, laying the groundwork for the North Pacific Fishery Management Council to move from Tier 5 (more data limited) to Tier 3 (less data limited) harvest control rules, which should lead to increased confidence with which the total allowable catch (TAC) for skates is set. Finally, I used the sustainable harvest estimates from the stock assessment models to develop a model that examined the impacts of management decisions on the profitability of skate fishing. My research provides essential information about these understudied fishes, helping to improve the sustainability and profitability of skate harvests. Incorporation of best available science regarding skate ecology, population dynamics, and bioeconomics into fishery management fosters more responsible development of skate fisheries, sustainable fishery revenues, and employment, and reduces the risk of overfishing, stock collapse, and prolonged fishery closures. It is my hope that fishery management agencies and the fishing industry make use of the new information and insights presented in this dissertation to work collaboratively towards the responsible development of skate fisheries

    On the multispacecraft determination of periodic surface wave phase speeds and wavelengths

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    Observations of surface waves on the magnetopause indicate a wide range of phase velocities and wavelengths. Their multispacecraft analysis allows a more precise determination of wave characteristics than ever before and reveal shortcomings of approximations to the phase speed that take a predetermined fraction of the magnetosheath speed or the average flow velocity in the boundary layer. We show that time lags between two or more spacecraft can give a qualitative upper estimate, and we confirm the unreliability of flow approximations often used by analyzing a few cases. Using two‐point distant magnetic field observations and spectral analysis of the tailward magnetic field component, we propose an alternative method to estimate the wavelength and phase speed at a single spacecraft from a statistical fit to the data at the other site

    6-Chloro-3,4-di­hydro-9H-carbazol-1(2H)-one

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    The carbazole unit of the title mol­ecule, C12H10ClNO, is not planar. The dihedral angle between the benzene and pyrrole rings is 1.35 (10)°. The cyclo­hexene ring adopts an envelope conformation. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds form centrosymmetric dimers

    4-Methyl-7,8,9,10-tetra­hydro­cyclo­hepta­[b]indol-6(5H)-one

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    In the title compound, C14H15NO, the seven-membered ring exhibits a slightly distorted twist-boat conformation. The pyrrole ring forms a dihedral angle of 1.44 (10)° with the fused benzene ring. N—H⋯O hydrogen bonds form a centrosymmetric dimer and weak C—H⋯π inter­actions are also found in the crystal structure

    4,4′-Dibromo-2-nitro­biphen­yl

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    The title compound, C12H7Br2NO2, a biphenyl derivative, displays a twisted conformation with the two benzene rings making a dihedral angle of 55.34 (14)°. The dihedral angle between the nitro group and its parent benzene ring is 26.8 (2)°. The crystal structure is stabilized by inter­molecular C—H⋯Br and C—H⋯O inter­actions, which lead to the formation of chains propagating along the c-axis direction

    4,8-Dimethyl­pyrano[2,3-a]carbazol-2(11H)-one

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    The mol­ecule of the title compound, C17H13NO2, is nearly planar, the r.m.s. deviation for all non-H atoms excluding the two methyl C atoms being 0.089 Å. Inter­molecular N—H⋯O and C—H⋯O hydrogen bonds are found in the crystal structure. C—H⋯π inter­actions are also found. The H atoms of the methyl group attached to the benzene ring are disordered equally over two positions

    2,3,6,7-Tetra­bromo-9-butyl-9H-carbazole

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    In he title compound, C16H13Br4N, the carbazole skeleton is nearly planar [maximum deviation = 0.026 (4) Å] and makes a dihedral angle of 73.8 (4)° with the butyl chain. The butyl chain adopts a trans conformation. In the crystal, mol­ecules are linked by π–π stacking inter­actions [centroid–centroid distance = 3.559 (2) Å]

    CME-HSS Interaction and Characteristics Tracked from Sun to Earth

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    In a thorough study, we investigate the origin of a remarkable plasma and magnetic field configuration observed in situ on June 22, 2011, near L1, which appears to be a magnetic ejecta (ME) and a shock signature engulfed by a solar wind high-speed stream (HSS). We identify the signatures as an Earth-directed coronal mass ejection (CME), associated with a C7.7 flare on June 21, 2011, and its interaction with a HSS, which emanates from a coronal hole (CH) close to the launch site of the CME. The results indicate that the major interaction between the CME and the HSS starts at a height of 1.3 R⊙ up to 3 R⊙. Over that distance range, the CME undergoes a strong north-eastward deflection of at least 30∘ due to the open magnetic field configuration of the CH. We perform a comprehensive analysis for the CME–HSS event using multi-viewpoint data (from the Solar TErrestrial RElations Observatories, the Solar and Heliospheric Observatory and the Solar Dynamics Observatory), and combined modeling efforts (nonlinear force-free field modeling, Graduated Cylindrical Shell CME modeling, and the Forecasting a CME’s Altered Trajectory – ForeCAT model). We aim at better understanding its early evolution and interaction process as well as its interplanetary propagation and related in situ signatures, and finally the resulting impact on the Earth’s magnetosphere

    Longitudinal conjunction between MESSENGER and STEREO A: Development of ICME complexity through stream interactions

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    We use data on an interplanetary coronal mass ejection (ICME) seen by MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) and STEREO A starting on 29 December 2011 in a near‐perfect longitudinal conjunction (within 3°) to illustrate changes in its structure via interaction with the solar wind in less than 0.6 AU. From force‐free field modeling we infer that the orientation of the underlying flux rope has undergone a rotation of ∼80° in latitude and ∼65° in longitude. Based on both spacecraft measurements as well as ENLIL model simulations of the steady state solar wind, we find that interaction involving magnetic reconnection with corotating structures in the solar wind dramatically alters the ICME magnetic field. In particular, we observed a highly turbulent region with distinct properties within the flux rope at STEREO A, not observed at MESSENGER, which we attribute to interaction between the ICME and a heliospheric plasma sheet/current sheet during propagation. Our case study is a concrete example of a sequence of events that can increase the complexity of ICMEs with heliocentric distance even in the inner heliosphere. The results highlight the need for large‐scale statistical studies of ICME events observed in conjunction at different heliocentric distances to determine how frequently significant changes in flux rope orientation occur during propagation. These results also have significant implications for space weather forecasting and should serve as a caution on using very distant observations to predict the geoeffectiveness of large interplanetary transients.Key PointsICME complexity increases due to interaction with corotating structures in the solar windMagnetic reconnection between ICME and HPS/HCS alters the magnetic topology of the ICME flux ropeCaution on using distant observations to predict the geoeffectiveness of interplanetary transientsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134123/1/jgra52739.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134123/2/jgra52739_am.pd
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