Effectiveness of habitat management for improving grey partridge populations: a BACI experimental assessment

We assessed the impact of field division (4 m bare ground strips within wheat fields) and food supplementation (supplied through grain feeders) on grey partridge Perdix perdix L. populations using six–year ‘before–after’/'control–impact’ (BACI) experiments. We did not detect any convincing positive effects of either of these two schemes on partridge pair density and reproductive success. Increases in pair densities were similar on managed and control areas, and contrasting results were found between some sites. No consistent pattern was observed between reproductive success and feeding intensity. Our studies highlight the need for field experiments at farm–scale to test the effectiveness of management measures. We conclude that, in the context in which they are applied, management techniques directed towards increasing partridge density do not systematically provide the desired outcome. We develop our point of view about management in the Discussion

Electromagnetic wave scattering by a superconductor

The interaction between radiation and superconductors is explored in this paper. In particular, the calculation of a plane standing wave scattered by an infinite cylindrical superconductor is performed by solving the Helmholtz equation in cylindrical coordinates. Numerical results computed up to $\mathcal{O}(77)$ of Bessel functions are presented for different wavelengths showing the appearance of a diffraction pattern.Comment: 3 pages, 3 figure

The ALTCRISS project on board the International Space Station

The Altcriss project aims to perform a long term survey of the radiation environment on board the International Space Station. Measurements are being performed with active and passive devices in different locations and orientations of the Russian segment of the station. The goal is to perform a detailed evaluation of the differences in particle fluence and nuclear composition due to different shielding material and attitude of the station. The Sileye-3/Alteino detector is used to identify nuclei up to Iron in the energy range above 60 MeV/n. Several passive dosimeters (TLDs, CR39) are also placed in the same location of Sileye-3 detector. Polyethylene shielding is periodically interposed in front of the detectors to evaluate the effectiveness of shielding on the nuclear component of the cosmic radiation. The project was submitted to ESA in reply to the AO in the Life and Physical Science of 2004 and data taking began in December 2005. Dosimeters and data cards are rotated every six months: up to now three launches of dosimeters and data cards have been performed and have been returned with the end of expedition 12 and 13.Comment: Accepted for publication on Advances in Space Research http://dx.doi.org/10.1016/j.asr.2007.04.03

Optical interface created by laser-cooled atoms trapped in the evanescent field surrounding an optical nanofiber

Trapping and optically interfacing laser-cooled neutral atoms is an essential requirement for their use in advanced quantum technologies. Here we simultaneously realize both of these tasks with cesium atoms interacting with a multi-color evanescent field surrounding an optical nanofiber. The atoms are localized in a one-dimensional optical lattice about 200 nm above the nanofiber surface and can be efficiently interrogated with a resonant light field sent through the nanofiber. Our technique opens the route towards the direct integration of laser-cooled atomic ensembles within fiber networks, an important prerequisite for large scale quantum communication schemes. Moreover, it is ideally suited to the realization of hybrid quantum systems that combine atoms with, e.g., solid state quantum devices

Investigating the chemical basis of functionality differences between beet and cane sugar sources in model egg white foams and other products

Though often used interchangeably, researchers have identified differences in functionality between beet and cane sugar sources in some food products. For example, previous research reported sensory differences between meringue cookies made with beet and cane sugar. Beet sugar meringue cookies were more marshmallow-like than cane meringue cookies. However, these sensory differences have not been instrumentally quantified and the underlying cause has not been determined. Thus, the objective of this research was to instrumentally quantify and investigate the chemical basis for the sensory differences between beet and cane meringue cookies. To instrumentally quantify differences between beet and cane meringue cookies, moisture content and water activity was obtained for unbaked meringues and meringue cookies. Additionally, texture profile analysis, three point break analysis, and differential scanning calorimetry was carried out on beet and cane meringue cookies. To gain insight into factors causing differences between beet and cane meringue cookies, heat denatured sugar-egg gel texture, unbaked foam stability, and water loss during simulated baking were obtained. No meaningful difference was found between beet and cane meringues in moisture content, water activity, and foam stability prior to baking. After baking, however, beet meringue cookies where shown to have higher moisture content, water activity, and cohesiveness values, and lower hardness and force to break values. During simulated baking, cane meringues were shown to lose water notable faster than beet meringues, causing moisture and textural differences after baking. These differences during and after baking are likely associated with higher amounts of sulfite in beet sugar compared to cane sugar. Sulfite has been shown to inhibit browning and cleave disulfide bonds, which may causes functional differences egg white proteins during the baking of meringues. To account for differences between beet and cane sugar functionality, a longer baking time for beet sugar meringue cookies is required, though this may lead to undesirable browning and loss of foam volume. Additionally, functional differences between beet and cane sugar were explored in rock candy, crème brûlée, and angel food cakes. This work highlights differences in functionality between beet and cane sugar sources, and raises issues regarding sugar source choice, in addition to market price

How to be causal: time, spacetime, and spectra

I explain a simple definition of causality in widespread use, and indicate how it links to the Kramers Kronig relations. The specification of causality in terms of temporal differential eqations then shows us the way to write down dynamical models so that their causal nature /in the sense used here/ should be obvious to all. To extend existing treatments of causality that work only in the frequency domain, I derive a reformulation of the long-standing Kramers Kronig relations applicable not only to just temporal causality, but also to spacetime "light-cone" causality based on signals carried by waves. I also apply this causal reasoning to Maxwell's equations, which is an instructive example since their casual properties are sometimes debated.Comment: v4 - add Appdx A, "discrete" picture (not in EJP); v5 - add Appdx B, cause classification/frames (not in EJP); v7 - unusual model case; v8 add reference

Synthesis gas as a fuel for internal combustion engines in transportation

© 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).The adverse environmental impact of fossil fuel combustion in engines has motivated research towards using alternative low-carbon fuels. In recent years, there has been an increased interest in studying the combustion of fuel mixtures consisting mainly of hydrogen and carbon monoxide, referred to as syngas, which can be considered as a promising fuel toward cleaner combustion technologies for power generation. This paper provides an extensive review of syngas production and application in internal combustion (IC) engines as the primary or secondary fuel. First, a brief overview of syngas as a fuel is presented, introducing the various methods for its production, focusing on its historical use and summarizing the merits and drawbacks of using syngas as a fuel. Then its physicochemical properties relevant to IC engines are reviewed, highlighting studies on the fundamental combustion characteristics, such as ignition delay time and laminar and turbulent flame speeds. The main body of the paper is devoted to reviewing the effect of syngas utilization on performance and emissions characteristics of spark ignition (SI), compression ignition (CI), homogeneous charge compression ignition (HCCI), and advanced dual-fuel engines such as reactivity-controlled compression ignition (RCCI) engines. Finally, various on-board fuel reforming techniques for syngas production and use in vehicles are reviewed as a potential route towards further increases in efficiency and decreases in emissions of IC engines. These are then related to the research reported on the behavior of syngas and its blends in IC engines. It was found that the selection of the syngas production method, choice of the base fuel for reforming, its physicochemical properties, combustion strategy, and engine combustion system and operating conditions play critical roles in dictating the potential advantages of syngas use in IC engines. The discussion of the present review paper provides valuable insights for future research on syngas as a possible fuel for IC engines for transport.Peer reviewe

Effects of geometric anisotropy on local field distribution: Ewald-Kornfeld formulation

We have applied the Ewald-Kornfeld formulation to a tetragonal lattice of point dipoles, in an attempt to examine the effects of geometric anisotropy on the local field distribution. The various problems encountered in the computation of the conditionally convergent summation of the near field are addressed and the methods of overcoming them are discussed. The results show that the geometric anisotropy has a significant impact on the local field distribution. The change in the local field can lead to a generalized Clausius-Mossotti equation for the anisotropic case.Comment: Accepted for publications, Journal of Physics: Condensed Matte