Signal Penetration into Thick Clouds Studied by Multi-Layer Data Observed with a Micro-Pulse Lidar

Lidar return signals are studied for a micro-pulse lidar under sky conditions with multi-layer clouds. From theoretical considerations on the lidar signal-to-noise ratio, it is estimated that the maximum cloud optical thickness detectable is about 3.7. This result reasonably agrees with the actual multi-layer cloud data obtained from observations in Sukhothai, Thailand. Deviations from theoretical prediction, however, are found for a geometrically thin but dense cloud, and for a moderately concentrated but geometrically thick cloud. The effect of multiple scattering is also discussed.     

The second‐order upwind finite difference fractional steps method for moving boundary value problem of oil‐water percolation

The research of the three‐dimensional (3D) compressible miscible (oil and water) displacement problem with moving boundary values is of great value to the history of oil‐gas transport and accumulation in basin evolution, as well as to the rational evaluation in prospecting and exploiting oil‐gas resources, and numerical simulation of seawater intrusion. The mathematical model can be described as a 3D‐coupled system of nonlinear partial differential equations with moving boundary values. For a generic case of 3D‐bounded region, a kind of second‐order upwind finite difference fractional steps schemes applicable to parallel arithmetic is put forward. Some techniques, such as the change of variables, calculus of variations, and the theory of a priori estimates, are adopted. Optimal order estimates in l² norm are derived for the errors in approximate solutions. The research is important both theoretically and practically for model analysis in the field, for model numerical method and for software development. Thus, the well‐known problem has been solved.Copyright © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 1103–1129, 2014     

Real‐time SAXS and WAXS study of the multiple melting behavior of poly(ε‐caprolactone)

The multiple melting behavior of poly(ε‐caprolactone) (PCL) was investigated by real‐time small angle X‐ray scattering (SAXS) and wide angle X‐ray scattering (WAXS) measurements coupling with differential scanning calorimetry (DSC). Semicrystalline specimens prepared by a continuous cooling process showed lengthening of the Bragg period during the progress of double melting. A model of variable thickness of lamella was proposed to fit to the SAXS patterns and revealed that both the crystalline lamella and the amorphous layer contributed to the increase in Bragg period while the later dominated the contribution. The model of variable thickness although satisfied the SAXS data was unable to compromise the data from other probing tools. A modification of the model proposed that each lamella piling up to construct the stacks in the crystallites was itself nonuniform in thickness. The modification with the parallel occurrence of the mechanism of surface melting and crystallization successfully compromised the observations from SAXS, DSC, and optical microscopy and provided a new perspective for the explanation to lengthening of the Bragg period related to multiple melting behavior. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1777–1785, 2010     

Single-mode fiber-optic directional couplers

A new design of Y-type end-fused single-mode fiber directional couplers has been suggested and its optimum parameters to obtain losses of 0,5–1 dB have been determined. A technique has been developed for fabricating such couplers by electric arc fusion of single-mode fibers with thin claddings. Excess loss in these couplers splitting into two channels is 1—3 dB and the value is in good agreement with calculations. Cross-talk attenuation between reverse channels exceeds 60 dB, which is an indication of high directivity of the couplers. It has been found by experiments that the developed couplers maintain the state of polarization of the propagating radiation.     

THE EXISTENCE OF MULTIPLE POSITIVE SOLUTION OF NONLINEAR NEUTRAL DIFFERENCE EQUATION

1IntroductionRecently,anumber0fmeth0dswereempl0yedf0r0btainingp0sitivesolu-tionstodifferenceequations,includingc0mparis0nprinciples,Schaudertypefixedp0inttheorem,Banach'scontractionprinciple,methods0fsuper-andlower-s0luti0ns,themethods0fpositive0perators,andso0n[1-4].Inthispa-per,wewillutilizethefixedpointindextheoryt00btainanexistencecriteriafOrmu1tiplep0sitivesolutionsofn0nlinearneutraldifferenceequationwheren,bi(15z5m1)andry(15j5m2)arep0sitiveinteger,{ci(k)}7=,(l5i5ml)and{pj(k)}7=,(15j5m2)…     

Neurodegeneration in Multiple Sclerosis: Symptoms of Silent Progression,Biomarkers and Neuroprotective Therapy—Kynurenines Are Important Players

Neurodegeneration is one of the driving forces behind the pathogenesis of multiple sclerosis (MS). Progression without activity, pathopsychological disturbances (cognitive impairment, depression, fatigue) and even optic neuropathy seems to be mainly routed in this mechanism. In this article, we aim to give a comprehensive review of the clinical aspects and symptomology, radiological and molecular markers and potential therapeutic targets of neurodegeneration in connection with MS. As the kynurenine pathway (KP) was evidenced to play an important role in the pathogenesis of other neurodegenerative conditions (even implied to have a causative role in some of these diseases) and more and more recent evidence suggest the same central role in the neurodegenerative processes of MS as well, we pay special attention to the KP. Metabolites of the pathway are researched as biomarkers of the disease and new, promising data arising from clinical evaluations show the possible therapeutic capability of KP metabolites as neuroprotective drugs in MS. Our conclusion is that the kynurenine pathway is a highly important route of research both for diagnostic and for therapeutic values and is expected to yield concrete results for everyday medicine in the future.     

Effects of digital processing on repeatability assessment of a multiple reaction monitoring liquid chromatography–tandem mass spectrometry system by ISO 11843-7

ISO 11843 part 7 (ISO 11843-7) can provide a standard deviation (SD) of area measurements of a target peak through the stochastic behaviors of instrumental noises. The purpose of this study is to demonstrate that ISO 11843-7 can be applied to assess repeatability in an isocratic liquid chromatography–tandem mass spectrometry (LC–MS/MS) system without repetitive measurements. The relative standard deviation (RSD) of the peak area of ergosterol picolinyl ester, which was used as an example, on a multiple reaction monitoring (MRM) chromatogram was determined by ISO 11843-7. The RSD by ISO 11843-7 (N = 1) was within a 95% confidence band of the RSD by repetitive measurements (N = 6). Moreover, the effects of digital smoothing, such as moving average, were also examined on the repeatability assessment in LC–MS/MS by ISO 11843-7. From the results of the comparisons of the RSDs obtained by ISO 11843-7 and the repetitive measurements, it was shown that suitable RSDs of the peak area were obtained from the smoothed MRM chromatograms by the moving average for narrow data point windows (e.g., one-sixth of the peak width). In conclusion, the utility of repeatability assessment based on ISO 11843-7 has been expanded for the validation of an LC–MS/MS system.     

Multiple Integral Inequalities for Schur Convex Functions on Symmetric and Convex Bodies

In this paper, by making use of Divergence theorem for multiple integrals, we establish some integral inequalities for Schur convex functions defined on bodies $B⊂\mathbb{R}^n$ that are symmetric, convex and have nonempty interiors. Examples for three dimensional balls are also provided.