Hyper-Rayleigh scattering in centrosymmetric systems

Hyper-Rayleigh scattering (HRS) is an incoherent mechanism for optical second harmonic generation. The frequency-doubled light that emerges from this mechanism is not emitted in a laser-like manner, in the forward direction; it is scattered in all directions. The underlying theory for this effect involves terms that are quadratic in the incident field and involves an even-order optical susceptibility (for a molecule, its associated hyperpolarizability). In consequence, HRS is often regarded as formally forbidden in centrosymmetric media. However, for the fundamental three-photon interaction, theory based on the standard electric dipole approximation, representable as E13, does not account for all experimental observations. The relevant results emerge upon extending the theory to include E12M1 and E12E2 contributions, incorporating one magnetic dipolar or electric quadrupolar interaction, respectively, to a consistent level of multipolar expansion. Both additional interactions require the deployment of higher orders in the multipole expansion, with the E12E2 interaction analogous in rank and parity to a four-wave susceptibility. To elicit the correct form of response from fluid or disordered media invites a tensor representation which does not oversimplify the molecular components, yet which can produce results to facilitate the interpretation of experimental observations. The detailed derivation in this work leads to results which are summarized for the following: perpendicular detection of polarization components both parallel and perpendicular to the pump radiation, leading to distinct polarization ratio results, as well as a reversal ratio for forward scattered circular polarizations. The results provide a route to handling data with direct physical interpretation, to enable the more sophisticated design of molecules with sought nonlinear optical properties

Assessment of bioavailability of some potential toxic metals in mining-affected soils using EDTA extraction and principle component analysis (PCA) approach, Derbyshire, UK

The current study area has long mining history for copper, lead, and zinc. As a result, these metals may have elevated levels and pose a potential risk to the surrounding area. This area is currently being used for agriculture and sheep rearing, therefore, the bioavailable fraction of some selected heavy metals namely (Cu, Pb, Zn, Mn, Cr, Ni, and V) has been evaluated using 0.01 M EDTA procedure, as this would help for better understanding of the risk that these heavy metals can pose to living organisms. A total of 51 samples of topsoils, floodplain soils, and stream sediment soils were collected and analysed for their total concentrations using ICP (Inductively Coupled Plasma) optical emission spectroscopy. Results show that, depending on the bioavailable ratio, soil samples have the biggest EDTA extractable amount for all studied metals, except for Mn and Cr for which highest levels were found in the floodplain samples. However, based on national bioavailable mean amount in England and Wales, the amount of EDTA metal extractable for all selected metals from soil samples are exceeded the national average amounts of England and Wales, except for Mn and Ni, whereas in floodplain and stream sediment samples, all EDTA metals extractions are lower than the national mean levels, except Cu and Zn for flood plan samples. Principal component analysis (PCA) technique was performed to investigate how the bioavailable fractions of studied metals and factors namely (organic matter contents, soil pH, and different granulometric ranges) are correlated. Results show that both organic matter amounts and fine fractions (clay and silt) were the master factors controlling the bioavailable portion in all soil types

Kinetic study of metal ion adsorption from wastewater onto coal industry by-products

Se llevó a cabo un estudio comparativo sobre el uso de cenizas volantes y clinker natural como adsorbentes de metales pesados de agua contaminada a partir de experimentos de adsorción a temperatura ambiente. Las concentraciones de metales pesados en los filtrados se determinaron por espectrometría de emisión atómica por plasma inductivamente acoplado. En los estudios de adsorción en batch, la retención aumento con el aumento del tiempo de contacto, la cantidad de adsorbente y el pH de la solución. La adsorción de los metales a partir de la solución contaminada artificialmente fue Cr>Cu>Pb>Ni>Zn, mientras que a partir de drenaje ácido de mina fue Pb>Zn>As>Fe>Cr>Cu>Ni. Las constantes de primer orden de Lagergren se calcularon para concentraciones iniciales de iones metálicos específicas, dando un excelente ajuste como lo indica el coeficiente de correlación (R2), con valores próximos o iguales a 1 para el tratamiento de la solución contaminada artificialmente y de 0.25 a 0.99 para el tratamiento del drenaje ácido de mina. Los datos de este estudio revelan que los cationes metálicos en solución acuosa pueden ser adsorbidos exitosamente en cantidades significativas por los adsorbentes usados

Raman scattering mediated by neighboring molecules

Raman scattering is most commonly associated with a change in vibrational state within individual molecules, the corresponding frequency shift in the scattered light affording a key way of identifying material structures. In theories where both matter and light are treated quantum mechanically, the fundamental scattering process is represented as the concurrent annihilation of a photon from one radiation mode and creation of another in a different mode. Developing this quantum electrodynamical formulation, the focus of the present work is on the spectroscopic consequences of electrodynamic coupling between neighboring molecules or other kinds of optical center. To encompass these nanoscale interactions, through which the molecular states evolve under the dual influence of the input light and local fields, this work identifies and determines two major mechanisms for each of which different selection rules apply. The constituent optical centers are considered to be chemically different and held in a fixed orientation with respect to each other, either as two components of a larger molecule or a molecular assembly that can undergo free rotation in a fluid medium or as parts of a larger, solid material. The two centers are considered to be separated beyond wavefunction overlap but close enough together to fall within an optical near-field limit, which leads to high inverse power dependences on their local separation. In this investigation, individual centers undergo a Stokes transition, whilst each neighbor of a different species remains in its original electronic and vibrational state. Analogous principles are applicable for the anti-Stokes case. The analysis concludes by considering the experimental consequences of applying this spectroscopic interpretation to fluid media; explicitly, the selection rules and the impact of pressure on the radiant intensity of this process

Mapping Low-Density Intergalactic Gas: a Third Helium Lyman-alpha Forest

We present a new HST/STIS spectrum of the z=3.18 quasar PKS 1935-692 and summarize the spectral features shortwards of 304A in the rest frame likely to be caused by foreground HeII Lyman-alpha absorption. In accord with previous results on two other quasars at similar redshifts, we demonstrate a correlation with the HI Lyman-alpha forest absorption, and show that much of the helium absorption is caused by a comparable quantity of more diffuse gas with Omega~0.01, that is not detected in HI. The helium ionization zone around the quasar is detected as well as a void seen in both HI and HeII. The properties of the absorption are in broad agreement with those of the other quasars and with models of the protogalactic gas distribution and ionization at this redshift.Comment: 17 pages including 5 figures. As accepted for publication in The Astronomical Journal (minor revisions

2014-2015 Illinois Trapper Report: Harvest, Effort, and Marketing Practices

Wesampled1,200 purchasersof2014resident Illinois trapping licensesfrom the Illinois Department of Natural Resources licensing database.Licensees were mailed a 4-page questionnaire, and we received 710 (58%) questionnaires.Trapping license sales increased 7%from 2013 (7,782licenses)to 2014 (8,303).Trappers set an average of 16.1traps for an average of 23.1days or nights during the 2014-2015season,and harvested an estimated179,978furbearers (down28% from the 251,178harvested in 2013-2014).An estimated 101,035raccoons (Procyon lotor) were trapped during the 2014-2015Illinois trapping season, adecreaseof33%from the estimated 151,367trapped during the 2013-2014 season.Muskrat(Ondatra zibethicus) harvest was the next highest at33,860muskrats(4% increasefrom the previous year).IDNRDivision of Wildlife U.S. Fish & Wildlife ServiceFederal Aid Project Number W-112-R-24unpublishednot peer reviewe

2017-2018 Illinois waterfowl hunter report: harvest, youth hunts, and zone option preferences

A total of 3,190 (44% response rate) Illinois waterfowl hunters returned usable questionnaires to the 2017-18 Illinois Waterfowl Hunter Survey. An estimated 37,215 adult waterfowl hunters spent 1 day or more afield during 2017-18, a decrease of 9.7% from the 41,242 hunters in 2016-17. Waterfowl hunters spent 732,166 days afield, a decrease of 15.9% from the 870,721 days devoted during the 2016-17 license year. Total waterfowl harvest decreased 0.4%, from 490,463 during 2016-17 to 421,384 during 2017-18. Duck harvest estimates for the regular duck season were as follows: 136,381 mallards (Anas platyrhynchos), 29,372 wood ducks (Aix sponsa), and 111,937 other ducks. A total of 15,062 teal (Anas spp.) were harvested during the September teal season. Goose hunters harvested 78,850 Canada geese (Branta canadensis) during the regular Canada goose season, a 2.1% increase from the 77,216 Canada geese harvested during the 2016-17 regular goose season. Hunters harvested 16,155 Canada geese during the September Canada goose season, an 8.8% decrease from the previous year. During the Youth Waterfowl Hunting Season, 4,780 adults took 6,459 youths waterfowl hunting, an 8.7% increase in adult participation and a 9.1% increase in youth participation from the 2016-17 Youth Waterfowl Hunting Season. Hunter preferences for season and zones, and satisfaction with the waterfowl seasons are also discussed.llinois Department of Natural Resources, Division of Wildlife U.S. Fish & Wildlife ServiceFederal Aid in Wildlife Restoration W-112-R-27unpublishednot peer reviewedOpe

2018-2019 Illinois Trapper Report: Harvest, Effort, and Marketing Practices

We sampled 1,200 of 2018 resident Illinois trapping license purchasers from the Illinois Department of Natural Resources licensing database. Licensees were mailed an 8-page questionnaire, and we received 739 (63%) questionnaires. Trapping license sales increased 7.6% from 2017-18 (5,964 licenses) to 2018-19 (6,416). Trappers set an average of 15.8 traps for an average of 26.4 days or nights during the 2018-19 season and harvested an estimated 127,990 furbearers (down 4.8% from the 134,560 harvested in 2017-18). An estimated 63,179 raccoons (Procyon lotor) were trapped during the 2018-19 Illinois trapping season, a decrease of 1.3% from the estimated 64,025 trapped during the 2017-18 season. Opossum (Didelphis virginiana) harvest was the next highest at 17,815 opossum (6.3% increase from the previous year). OBJECTIVEFederal Aid Project Number W-112-R-28unpublishednot peer reviewedOpe

LC–MS/MS determination of carbamathione in microdialysis samples from rat brain and plasma

A selective liquid chromatography–tandem mass spectrometric (LC–MS/MS) method was developed for the determination of S-(N, N-diethylcarbamoyl) glutathione (carbamathione) in microdialysis samples from rat brain and plasma. S-(N, N-Diethylcarbamoyl) glutathione (carbamathione) is a metabolite of disulfiram. This metabolite may be responsible for disulfiram’s effectiveness in the treatment of cocaine dependence. An analytical method using liquid chromatography–tandem mass spectrometric (LC–MS/MS) was developed to determine carbamathione in vivo using microdialysis sampling from rat brain and plasma. Chromatographic separations were carried out on an Alltech Altima C-18 (50 mm long × 2.1 mm i.d., 3 μm particles) analytical column at a flow rate of 0.3 ml/min. Solvent A consisted of 10 mM ammonium formate, methanol, and formic acid (99:1:0.06, v/v/v). Solvent B consisted of methanol, 10 mM ammonium formate and formic acid (99:1:0.06, v/v/v). A 20 min linear gradient from 95% aqueous to 95% organic was used. Tandem mass spectra were acquired on a Micromass Quattro Ultima “triple” quadrupole mass spectrometer equipped with an ESI interface. Quantitative mass spectrometric analysis was conducted in positive ion mode selected reaction monitoring (SRM) mode looking at the transition of m/z 407–100 and 175 for carbamathione and m/z 392–263 for the internal standard S-hexyl glutathione. The simultaneous collection of microdialysate from blood and brain was used to monitor carbamathione concentrations centrally and peripherally. Good linearity was obtained over a concentration range of 0.25–10,000 nM. The lowest limit of quantification (LLOQ) was determined to be 1 nM and the lowest limit of detection (LLOD) was calculated to be 0.25 nM. Intra- and inter-day accuracy and precision were determined and for all the samples evaluated, the variability was less that 10% (R.S.D.)