Scattering error corrections for in situ absorption and attenuation measurements

Monte Carlo simulations are used to establish a weighting function that describes the collection of angular scattering for the WETLabs AC-9 reflecting tube absorption meter. The equivalent weighting function for the AC-9 attenuation sensor is found to be well approximated by a binary step function with photons scattered between zero and the collection half-width angle contributing to the scattering error and photons scattered at larger angles making zero contribution. A new scattering error correction procedure is developed that accounts for scattering collection artifacts in both absorption and attenuation measurements. The new correction method does not assume zero absorption in the near infrared (NIR), does not assume a wavelength independent scattering phase function, but does require simultaneous measurements of spectrally matched particulate backscattering. The new method is based on an iterative approach that assumes that the scattering phase function can be adequately modeled from estimates of particulate backscattering ratio and Fournier-Forand phase functions. It is applied to sets of in situ data representative of clear ocean water, moderately turbid coastal water and highly turbid coastal water. Initial results suggest significantly higher levels of attenuation and absorption than those obtained using previously published scattering error correction procedures. Scattering signals from each correction procedure have similar magnitudes but significant differences in spectral distribution are observed

Asymptotic light field in the presence of a bubble-layer

We report that the submerged microbubbles are an efficient source of diffuse radiance and may contribute to a rapid transition to the diffuse asymptotic regime. In this asymptotic regime an average cosine is easily predictable and measurable.Comment: 4 pages, 3 Postscript figures, opex2.sty (enclosed), also available from the Optical Society of America htpp://epubs.osa.org/oearchive/pdf/11948.pd

The compatibility of positive psychology and the Ludic strategy in foreign language education

The Ludic strategy, an approach to foreign language teaching (FLT), popularised by the present author since the 1990’s which acknowledges the value of a humanistic approach, yet also emphasises an emergence of positive feelings, while engaging in the ludic tasks for FLT purposes, is in line with the claims of positive psychology. For the analysis the most popular model of the well-being theory, Seligman’s PERMA model will be used. Referring to research in FLT on language competence, I will analyse the benefits of applying LS in the FL classroom, and by using the PERMA model I will show that LS can be treated as a useful tool for FLT congruent with the claims of positive psychology, and that the model can be used in planning FLT research

Longitudinal shear of bi-material with interfacial crack considering friction

Побудовано точний розв’язок антиплоскої задачі для біматеріалу з міжфазною тріщиною, навантаженого неоднорідним нормальним стиском та циклічним навантаженням у поздовжньому напрямку. Методом функцій стрибка задача зведена до системи сингулярних інтегральних рівнянь для стрибків зміщень і напружень у зонах проковзування з тертям. Проаналізовано вплив параметрів навантажування і тертя на розміри цих зон та дисипацію енергії.The present paper investigates the anti-plane problem for a semi-homogeneous bi-material with the closed interface crack considering sliding friction. Solid is exposed to the combined cyclic loading in the longitudinal direction and arbitrary normal load required to prevent loss of contact between the sliding surfaces of the cracks. It is assumed that the load on each step of loading increases from zero to its maximum monotonically and slowly enough not to consider the effect of inertia. Using jump function method the problem is reduced to the solution of singular integral equations with a Cauchy-type kernel for the jumps of displacements and stresses in areas with sliding friction. This solution allows us to obtain explicit expressions for displacements, stress intensity factors and energy dissipation. Analyzing of the elasticity problem involving friction under the variable (cyclic) loading requires consideration of the history of loading. No incremental formulation is necessary for solving of this problem on each local step because of quasi-statically way of the step loading. To take account of cyclical loading multistep method of solution is proposed. The basis of this technique is the idea of consideration at every step of loading previous step stresses and displacements as the residual. Correctness of the obtained solution is justified. Evolution of the slip zone in matrix is considered at different stages of loading. Critical load values for determining the onset of slip are investigated. Available size of slip zone with an increase in loading is determined from the condition of equality to zero the stress intensity factor. Upon reaching the second critical value of the load, when the slip zone size matches the size of the crack, there are singular stresses in the crack threshold and non-zero values of stress intensity factors. We numerically analyze the effect of friction and loading parameters on the size of slip zone and stress intensity factors. It is discovered that the slip zone appears and grows fastest when it pressing normal stresses are minimal. Growth rate of slip zone also promotes increasing the distance of application points of concentrated power factors from her. The growth coefficient of friction significantly reduces the intensity of the stresses in the vicinity of the ends of the crack. Energy dissipation for all examined cases of loading was calculated

Learners’ personal narratives on their way to EFL competence: The impact of teachers on learners’ development

In this paper, the authors present an analysis of students’ narratives on their way to becoming competent English as a foreign language (EFL) users. Before presenting our study we refer to the ecological perspective on language learning/teaching, which may show the important impact of the learners’ environment for EFL development. We refer to studies which point to the importance of the environment for language learning and which used various methods of research. In our study, we apply a narrative approach. The collected corpus of narratives is analysed following the grounded theory within the psychological model of wellbeing, i.e. the PERMA model. Eventually, we decided to concentrate on the impact teachers have on learners’ emotions, engagement, meaning, relationships and accomplishment

POLEMIKA Z MARCJONIZMEM W ORYGENESA KOMENTARZU DO „LISTU ŚWIĘTEGO PAWŁA DO RZYMIAN”

The Polemic with Marcionism in Origenes’ Commentary to the „Letter of St. Paul to the Romans”The article discusses the references to Marcion of Pont as well as to Marcionites contained in Origenes’ commentary to St. Paul’s Letter to the Romans. It was particularly those places where the commentator mentions the heresiarch by name that were taken into consideration; on this basis the views ascribed to the Marcianites are analyzed. Moreover, the author quotes those fragments of the text which though do not mention Marcion directly, yet which contain remarks directed against certain unspecified heresies; the latter may also be regarded as part of Marcion’s teaching. The analyzed fragments of  the commentary point out, above all, to the most important element of Marcion’s heresy , in Origenes’ view, namely to his insistence on the literal interpretation of the Holy Scripture which had led this preacher from Pont to a rejection of the whole of the Old and a considerable part of the New Testament. Also the interpretation of those writings of St. Paul’s which Marcion regards as inspired turns out to be erroneous precisely due to the author’s failure to use an allegorical exegesis. In the conclusions, the author points out that although Origenes presents Marcion’s views, he does not devote a lot of attention to refuting them. Nevertheless, he points out emphatically that in order to assure the correct theological interpretation of the Holy Scripture, one needs to recognize both the literal and the allegorical sense of it

Signal of single scattering albedo in water leaving polarization

The purpose of this article is to examine whether the change in single scattering albedo in the surface layer of the sea will cause significantchanges in the polarization of light emerging from the sea. The results of a polarization resolving Monte Carlo radiative transfer calculationsare presented. Bubble clouds of different bubble concentrations are used to achieve a wide range of single scattering albedo variability. Thevariability of the polarization signal is largest in the direction looking towards the sun which is unfortunate due to sun reflection. Howeverthe variability is also significant at direction perpendicular to solar azimuth angle which should it make possible to use this signal in remotesensing. The polarization degree of water leaving radiation, together with reflectance can be used to determine the backscattering ratio ofthe observed sea water

Evaluation and improvement of an iterative scattering correction scheme for in situ absorption and attenuation measurements

The performance of several scattering correction schemes for reflecting-tube absorption and beam attenuation measurements is evaluated with data collected in European shelf seas. Standard scattering correction procedures for absorption measurements perform poorly because of nonzero absorption in the near infrared and wavelength-dependent scattering phase functions. A previously described iterative correction procedure based on Monte Carlo simulations of the Western Environmental Technologies Laboratories (WET Labs) ac-9 and independent estimates of particle backscattering initially performs poorly, but is greatly improved when realistic losses at flow-tube walls are incorporated into the model. The updated Monte Carlo scattering correction provides excellent agreement with independent absorption and attenuation measurements made with a point-source integrating-cavity absorption meter (PSICAM) and a Laser In Situ Scattering and Transmissometer (LISST, Sequoia Scientific), respectively. Implications for historic datasets and requirements for application to future datasets are discussed