Optimum Power in a Multi-Span DWDM System Limited by Non-Linear Effects

Limitations imposed by Four-Wave Mixing (FWM), Amplified Spontaneous Emission (ASE), dispersion and Stimulated Raman Scattering (SRS) on a multi-spam DWDM system are theoretically studied. In this work, expression for the linear dispersion parameter D has been defined as a function of number of channels in order to separate FWM and SRS effects and calculates both maximum fibre length and optimum power. Additionally, our simulation results consider the effect of ASE noise from Erbium Doped Fibre Amplifiers (EDFAs). This theoretical analysis yields a set of design criteria from optimized multi-span DWDM systems

Thermal Diffusion and Specular Reflection, Monte Carlo-based Study on Human Skin via Pulsed Fiber Laser Energy

The aim of traditional Chinese medicine (TCM) in acupuncture is sometimes to restore and regulate energy balance by stimulating specific points along the specific meridians traced on the human body via different techniques such as mechanical pressure, moxibustion and others. Hence, physicians have struggled to improve treatment for common diseases such as migraine and headaches. Heat stimulation and some pharmacological effects from moxa have been attributed to the therapeutic efficacy of such techniques. As heat can diffuse through the tissue, skins temperature will rise in the surrounding tissue. In this work, heat diffusion on a simple, 5-layer model of human skin is presented. Based on this, and by using Monte Carlo techniques, a photon or a photon package is launched into the tissue for mimicking the propagation of such photons at two different wavelengths through the tissue. The method generally describes the scholastic nature of radiation interactions. Most of the laser energy is deposited within a volume which cross-sectional area is the size of the beam itself. As could be seen, in the epidermis layer of the model, the heat does not go deep and nearly all the heat diffusion occurs on the edges of the beam, causing losses. Heat dissipation occurs faster and goes down to 2°C in the adipose tissue since there is low water content in this region. On the contrary, there is a fast heat increase in the muscle layer, up to 6°C at the most superficial layer. Since melanin is the most important epidermal chromophore, it can be noted that light shows strong absorption via melanin, at 690nm laser wavelength. In the papillary dermis the heat decreases and spreads out to the surrounding tissue. Once it reaches the adipose tissue, the heat is not absorbed enough; therefore, it is transmitted into the muscle, where the temperature rise is higher and reaches nearly 40 °C. Finally, photodynamics in a simple 5-layer skin model were explored at two laser wavelengths: 690nm and 1069nm, where no thermal damage would be expected, given the energy level of the employed pulses. Such pulsed laser energy levels remain to be tested in living tissue

ASE Noise Characterization of an All-Fiber Sagnac Interferometer via LAN for Remote Sensing

The spectral noise characteristic and relative intensity noise of an all-fibre Sagnac interferometer consisting of pump source, a WDM, a piece of Er-doped fibre, a fibre Bragg grating (FBG), an optical circulator and a 50/50 coupler, were studied over a 75C-degree range. At the probing end, a high-birefringence piece of fibre and a Peltier were employed for temperature variation. Spectral and temperature response of the noise reduction due to temperature variation was performed remotely using an Arduino micro-controller and a DS18B20 digital sensor and fed into a local area network. Optical and thermal characterization of the system has also been undertaken

Optimizing the yield and physico-chemical properties of pine cone cellulose nanocrystals by different hydrolysis time

[EN] Cellulose nanocrystals (CNCs) were isolated for the first time from pine cones (PC) by alkali and bleaching treatments and subsequent sulfuric acid hydrolysis (64 %) at 45 ºC. The influence of the hydrolytic reaction time (30, 45 and 90 min) on the yield, chemical composition and structure, and thermal stability of CNCs was evaluated. The removal of non-cellulosic constituents during the alkaline and bleaching treatment resulted in high pure cellulosic fibres. The isolation of CNCs from these cellulosic fibres at different reaction times was verified by the nano-dimensions of the individual crystals (< 3 and <335 nm of average diameter and length, respectively). The highest yield (15%) and the optimum CNCs properties in terms of aspect ratio, thermal stability and crystallinity were obtained for an extraction time of 45 min. PC appeared to be a new promising source of cellulose fibres and CNCs with potential to be applied as reinforcement in composites and for food-packaging.This work was supported by the Ministry of Economy and Competitiveness (MINECO) [MAT2014-59242-C2-1-R]. D. García-García wants to thanks the Spanish Ministry of Education, Culture and Sports for their financial support through an FPU Grant [FPU13/06011].Garcia-Garcia, D.; Balart, R.; López-Martínez, J.; Ek, M.; Moriana, R. (2018). Optimizing the yield and physico-chemical properties of pine cone cellulose nanocrystals by different hydrolysis time. Cellulose. 25(5):2925-2938. https://doi.org/10.1007/s10570-018-1760-0S2925293825

Intersectional Gene Expression in Zebrafish Using the Split KalTA4 System

In this study, we describe the adaptation of the split Gal4 system for zebrafish. The Gal4-UAS system is widely used for expression of genes-of-interest by crossing driver lines expressing the transcription factor Gal4 (under the control of the promoter of interest) with reporter lines where upstream activating sequence (UAS) repeats (recognized by Gal4) drive expression of the genes-of-interest. In the Split Gal4 system, hemi-drivers separately encode the DNA-binding domain (DBD) and the activation domain (AD) of Gal4. When encoded under two different promoters, only those cells in the intersection of the promoters' expression pattern and in which both promoters are active reconstitute a functional Gal4 and activate expression from a UAS-driven transgene. We split the zebrafish-optimized version of Gal4, KalTA4, and generated a hemi-driver encoding the KalTA4 DBD and a hemi-driver encoding KalTA4's AD. We show that split KalTA4 domains can assemble in vivo and transactivate a UAS reporter transgene and that each hemi-driver alone cannot transactivate the reporter. Also, transactivation can happen in several cell types, with similar efficiency to intact KalTA4. Finally, in transient mosaic expression assays, we show that when hemi-drivers are preceded by two distinct promoters, they restrict the expression of an UAS-driven reporter from a broader pattern (sox10) to its constituent smaller neuronal pattern. The Split KalTA4 system should be useful for expression of genes-of-interest in an intersectional manner, allowing for more refined manipulations of cell populations in zebrafish

Twisted Bethe equations from a twisted S-matrix

All-loop asymptotic Bethe equations for a 3-parameter deformation of AdS5/CFT4 have been proposed by Beisert and Roiban. We propose a Drinfeld twist of the AdS5/CFT4 S-matrix, together with c-number diagonal twists of the boundary conditions, from which we derive these Bethe equations. Although the undeformed S-matrix factorizes into a product of two su(2|2) factors, the deformed S-matrix cannot be so factored. Diagonalization of the corresponding transfer matrix requires a generalization of the conventional algebraic Bethe ansatz approach, which we first illustrate for the simpler case of the twisted su(2) principal chiral model. We also demonstrate that the same twisted Bethe equations can alternatively be derived using instead untwisted S-matrices and boundary conditions with operatorial twists.Comment: 42 pages; v2: a new appendix on sl(2) grading, 2 additional references, and some minor changes; v3: improved Appendix D, additional references, and further minor changes, to appear in JHE

Happy Moves? Assessing the Link between Life Satisfaction and Emigration Intentions

© 2015 John Wiley & Sons Ltd. It has been shown that higher levels of subjective well-being lead to greater work productivity, better physical health and enhanced social skills. Because of these positive externalities, policymakers across the world should be interested in attracting and retaining happy and life-satisfied migrants. This paper studies the link between life satisfaction and one's intentions to move abroad. Using survey data from 35 European and Central Asian countries, I find a U-shaped association between life satisfaction and emigration intentions: it is the most and the least life-satisfied people who are the most likely to express intentions to emigrate. This result is found in countries with different levels of economic development and institutional quality. The instrumental variable results suggest that higher levels of life satisfaction have a positive effect on the probability of reporting intentions to migrate. The findings of this paper raise concerns about possible 'happiness drain' in migrant-sending countries