Optical Interferometers with Reduced Sensitivity to Thermal Noise

A fundamental limit to the sensitivity of optical interferometry is thermal noise that drives fluctuations in the positions of the surfaces of the interferometer's mirrors, and thereby in the phase of the intracavity field. Schemes for reducing this thermally driven phase noise are presented in which phase shifts from concomitant strains at the surface and in the bulk of the substrate compensate the phase shift due to the displacement of the surface. Although the position of the physical surface fluctuates, the optical phase upon reflection can have reduced sensitivity to this motion.Comment: 5 pages, 3 figure

Frequency stabilization of a monolithic Nd:YAG ring laser by controlling the power of the laser-diode pump source

The frequency of a 700mW monolithic non-planar Nd:YAG ring laser (NPRO) depends with a large coupling coefficient (some MHz/mW) on the power of its laser-diode pump source. Using this effect we demonstrate the frequency stabilization of an NPRO to a frequency reference by feeding back to the current of its pump diodes. We achieved an error point frequency noise smaller than 1mHz/sqrt(Hz), and simultaneously a reduction of the power noise of the NPRO by 10dB without an additional power stabilization feed-back system.Comment: accepted for publication by Optics Letter

Transfer Pricing Rules in the BRICS World: A Shifting Balance in Global Taxation Governance?

The rise of the BRICS (Brazil, Russia, India, China and South Africa) as major emerging powers has challenged existing important structures in the global economy. For this reason, there is an expectation that this restructuring may also occur in the international tax regime. In this respect, transfer pricing is one potential area for cooperation between the BRICS, which have faced challenges in applying the existing international standard – the traditional arm’s length approach as established by the OECD – in practice. Therefore, this thesis investigates the differences between the transfer pricing regulations of the BRICS and those of the OECD, examining the potential for cooperation between these countries and their impact on the international tax debate. The author concludes that the substantial differences among the BRICS prevent them from developing a unified and cohesive transfer pricing policy. However, the BRICS have demonstrated an ability to individually influence the international transfer pricing regime

Escalation Clauses in Washington Child Support Awards

This comment analyzes the Washington courts\u27 interpretation of the statutes providing for making and modifying child support awards and the policies these statutes are designed to effect. It concludes that the use of escalation clauses is consistent with the statutes and policies on which the Washington support system is based, and that the use of such clauses is a more effective means of promoting the state\u27s policy of providing adequate child support than the traditional approach of awarding support in fixed amounts subject to court modification. Finally, the comment suggests one possible escalation device that seeks to accurately predict future increases in child support needs

Optimization of operating conditions of an internal combustion engine used as chemical reactor for methane reforming using ozone as an additive

Internal combustion engines can be used as chemical reactors exploiting the high temperature and pressure as well as short residence time for chemical conversion. For instance, methane and CO$_{2}$ can be efficiently converted to H$_{2}$ and CO (syngas). The process can be boosted by additives such as dimethyl ether (DME). In this paper, the focus is on optimizing the operating conditions for the use of ozone, O$_{3}$, as an alternative fuel additive for dry reforming of methane. Furthermore, methane can be converted to C$_{2}$ hydrocarbons, which is also studied numerically to find optimized operating conditions, again using O$_{3}$ as an additive. The engine is modelled as a single-zone batch reactor under ideal gas assumptions with a variable volume profile. An elementary-step reaction mechanism consisting of 749 reactions among 132 species and including O$_{3}$ chemistry was used for the simulations. CO$_{2}$ conversion of over 70% is possible using O$_{3}$ as an additive, whereas the maximum achievable using DME was around 50%. The optimized yield of C$_{2}$H$_{4}$ is higher with O$_{3}$ as an additive as compared to DME, at all the inlet gas temperatures, whereas it is lower for CH$_{2}$O and comparable for C$_{6}$H$_{6}$ and CH$_{3}$OH

Observation of squeezed light with 10dB quantum noise reduction

Squeezing of light's quantum noise requires temporal rearranging of photons. This again corresponds to creation of quantum correlations between individual photons. Squeezed light is a non-classical manifestation of light with great potential in high-precision quantum measurements, for example in the detection of gravitational waves. Equally promising applications have been proposed in quantum communication. However, after 20 years of intensive research doubts arose whether strong squeezing can ever be realized as required for eminent applications. Here we show experimentally that strong squeezing of light's quantum noise is possible. We reached a benchmark squeezing factor of 10 in power (10dB). Thorough analysis reveals that even higher squeezing factors will be feasible in our setup.Comment: 10 pages, 4 figure

Context-dependent functional divergence of the notch ligands DLL1 and DLL4 In Vivo

Copyright: © 2015 Preuße et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNotch signalling is a fundamental pathway that shapes the developing embryo and sustains adult tissues by direct communication between ligand and receptor molecules on adjacent cells. Among the ligands are two Delta paralogues, DLL1 and DLL4, that are conserved in mammals and share a similar structure and sequence. They activate the Notch receptor partly in overlapping expression domains where they fulfil redundant functions in some processes (e.g. maintenance of the crypt cell progenitor pool). In other processes, however, they appear to act differently (e.g. maintenance of foetal arterial identity) raising the questions of how similar DLL1 and DLL4 really are and which mechanism causes the apparent context-dependent divergence. By analysing mice that conditionally overexpress DLL1 or DLL4 from the same genomic locus (Hprt) and mice that express DLL4 instead of DLL1 from the endogenous Dll1 locus (Dll1Dll4ki), we found functional differences that are tissue-specific: while DLL1 and DLL4 act redundantly during the maintenance of retinal progenitors, their function varies in the presomitic mesoderm (PSM) where somites form in a Notch-dependent process. In the anterior PSM, every cell expresses both Notch receptors and ligands, and DLL1 is the only activator of Notch while DLL4 is not endogenously expressed. Transgenic DLL4 cannot replace DLL1 during somitogenesis and in heterozygous Dll1Dll4ki/+ mice, the Dll1Dll4ki allele causes a dominant segmentation phenotype. Testing several aspects of the complex Notch signalling system in vitro, we found that both ligands have a similar trans-activation potential but that only DLL4 is an efficient cis-inhibitor of Notch signalling, causing a reduced net activation of Notch. These differential cis-inhibitory properties are likely to contribute to the functional divergence of DLL1 and DLL4.Funding: This work was supported by grant GO 449/13-1 from the Deutsche Forschungsgemeinschaft (http://www.dfg.de) to AG, by funding of the Cluster of Excellence “From Regenerative Biology to Reconstructive Therapy” to AG (http://www.mh-hannover.de/rebirth.html) and by grant PTDC/SAU-BID/121846/2010 of the Fundação para a Ciência e a Tecnologia (http://www.fct.pt/index.phtml.en) to DH.info:eu-repo/semantics/publishedVersio

Applying the Delphi method to determine best practices for outsourcing logistics in disaster relief

Purpose: The purpose of this paper is to determine best practices of aid agencies for outsourcing logistics tocommercial logistics service providers (LSPs) in disaster relief. Moreover, it evaluates the application of the Delphi method for research in humanitarian logistics. Design/methodology/approach: The paper is based on a two-round Delphi study with 31 experts from aid agencies and a complementary full-day focus group with 12 experts from aid agencies and LSPs. Findings: The study revealed 12 best practices for outsourcing logistics in disaster relief and a compilation of more than 100 activities for putting these practices into action. Experts consider a proper balance between efficiency and compliance, a detailed contract and a detailed service request most important. Additionally, the Delphi method was found to be a promising technique for research on humanitarian logistics. Research limitations/implications: By critically examining the Delphi method, this study establishes the basis for a wider application of the technique in the field of humanitarian logistics. Furthermore, it can help to prioritize future research as the ranking of practices reflects the priorities of practitioners. Practical implications: The paper provides guidance to practitioners at aid agencies in charge ofoutsourcing logistics. Originality/value: This research is one of the first in the field of humanitarian logistics to apply the Delphi method. Moreover, it addresses the lack of literature dealing with approaches for building successful cross-sectoral partnerships

How to increase the impact of disaster relief: A study of transportation rates, framework agreements and product distribution

Due to restricted budgets of relief organizations, costs of hiring transportation service providers steer distribution decisions and limit the impact of disaster relief. To improve the success of future humanitarian operations, it is of paramount importance to understand this relationship in detail and to identify mitigation actions, always considering the interdependencies between multiple independent actors in humanitarian logistics. In this paper, we develop a game-theoretic model in order to investigate the influence of transportation costs on distribution decisions in long-term relief operations and to evaluate measures for improving the fulfillment of beneficiary needs. The equilibrium of the model is a Generalized Nash Equilibrium, which has had few applications in the supply chain context to date. We formulate it, utilizing the construct of a Variational Equilibrium, as a Variational Inequality and perform numerical simulations in order to study the effects of three interventions: an increase in carrier competition, a reduction of transportation costs and an extension of framework agreements. The results yield important implications for policy makers and humanitarian organizations (HOs). Increasing the number of preselected carriers strengthens the bargaining power of HOs and improves impact up to a certain limit. The limit is reached when carriers set framework rates equal to transportation unit costs. Reductions of transportation costs have a consistently positive, but decreasing marginal benefit without any upper bound. They provide the highest benefit when the bargaining power of HOs is weak. On the contrary, extending framework agreements enables most improvements when the bargaining power of HOs is strong