XPS and AFM study of interaction of organosilane and sizing with e-glass fibre surface

Organosilanes are often used in commercial sizings for glass fibres to provide wettability with the resin and promote strong interfacial adhesion to the matrix in a fibre reinforced polymer composite. The silane treatment is introduced as part of a complex deposition from an aqueous emulsion immediately at the spinaret and determines the optimum properties of the cured composite. To understand the interaction of organosilanes contained in sizings for glass surfaces, XPS was used to investigate the adsorption of γ-aminopropyltriethoxysilane (APS) from a simple sizing system containing a polyurethane (PU) film former. It has been found that both APS and the sizing (containing APS and PU) deposits on E-glass fibre surfaces contained components of differing hydrolytic stability. The differences observed in the AFM images of APS coated E-glass fibres before and after water extraction also confirmed that the APS deposit contained components with different water solubility

Effects of weight, temperature and behaviour on the circadian rhythm of salivary cortisol in growing pigs

In farm animals, salivary cortisol has become a widely used parameter for measuring stress responses. However, only few studies have dealt with basal levels of concentration of cortisol in pigs and its circadian rhythm. The aim of this study was to examine the effects of ambient temperature and thermoregulatory behaviour on the circadian rhythm of salivary cortisol levels in fattening pigs. Subjects were 30 fattening pigs of different weight (60 to 100 kg), kept in six groups in an uninsulated building in pens with partly slatted floors. Saliva samples were taken every 2 h over periods of 24 h at different ambient temperatures at two times in winter and four times in summer. Thermoregulatory behaviour was recorded in the same 24-h time periods. The effect of time of day, body weight, ambient temperature and behaviour on the cortisol level was analysed using a mixed-effects model. Two peaks of cortisol levels per day were found. This circadian pattern became more pronounced with increasing weight and on days where thermoregulatory behaviour was shown. Mean cortisol levels per day were affected by weight but not by thermoregulatory behaviour. From our data, we conclude that long-term variations in cortisol concentration may be influenced by increasing age and weight more than by the respective experimental situation. In assessing animal welfare, it seems more reliable to consider the circadian pattern of cortisol concentration instead of only one value per da

An operational satellite scatterometer for wind vector measurements over the ocean

Performance requirements and design characteristics of a microwave scatterometer wind sensor for measuring surface winds over the oceans on a global basis are described. Scatterometer specifications are developed from user requirements of wind vector measurement range and accuracy, swath width, resolution cell size and measurement grid spacing. A detailed analysis is performed for a baseline fan-beam scatterometer design, and its performance capabilities for meeting the SeaSat-A user requirements. Various modes of operation are discussed which will allow the resolution of questions concerning the effects of sea state on the scatterometer wind sensing ability and to verify design boundaries of the instrument

Generation of Requirements for Simulant Measurements

This TM presents a formal, logical explanation of the parameters selected for the figure of merit (FoM) algorithm. The FoM algorithm is used to evaluate lunar regolith simulant. The objectives, requirements, assumptions, and analysis behind the parameters are provided. A requirement is derived to verify and validate simulant performance versus lunar regolith from NASA s objectives for lunar simulants. This requirement leads to a specification that comparative measurements be taken the same way on the regolith and the simulant. In turn, this leads to a set of nine criteria with which to evaluate comparative measurements. Many of the potential measurements of interest are not defensible under these criteria. For example, many geotechnical properties of interest were not explicitly measured during Apollo and they can only be measured in situ on the Moon. A 2005 workshop identified 32 properties of major interest to users. Virtually all of the properties are tightly constrained, though not predictable, if just four parameters are controlled. Three parameters (composition, size, and shape) are recognized as being definable at the particle level. The fourth parameter (density) is a bulk property. In recent work, a fifth parameter (spectroscopy) has been identified, which will need to be added to future releases of the FoM

An FPGA-Based System for Tracking Digital Information Transmitted Via Peer-to-Peer Protocols

This paper presents a Field Programmable Gate Array (FPGA)-based tool designed to process file transfers using the BitTorrent Peer-to-Peer (P2P) protocol and VoIP phone calls made using the Session Initiation Protocol (SIP). The tool searches selected control messages in real time and compares the unique identifier of the shared file or phone number against a list of known contraband files or phone numbers. Results show the FPGA tool processes P2P packets of interest 92% faster than a software-only configuration and is 97.6% accurate at capturing and processing messages at a traffic load of 89.6 Mbps

A temperature and magnetic field dependence Mössbauer study of ɛ-Fe2O3

ɛ-Fe2O3 was synthesized as nanoparticles by a pre-vacuum heat treatment of yttrium iron garnet (Y3Fe5O12) in a silica matrix at 300-C followed by sintering in air at 1,000-C for up to 10 h. It displays complex magnetic properties that are characterized by two transitions, one at 480 K from a paramagnet (P) to canted antiferromagnet (CAF1) and the second at ca. 120 K from the canted antiferromagnet (CAF1) to another canted antiferromagnet (CAF2). CAF2 has a smaller resultant magnetic moment (i.e. smaller canting angle) than CAF1. Analysis of the zero-field Mossbauer spectra at different temperatures shows an associated discontinuity of the hyperfine field around 120 K. In an applied field, the different magnetic sublattices were identified and the directions of their moments were assigned. The moments of the two sublattices are antiparallel and collinear at 160 K but are at right angle to each other at 4.2 K

Positronic lithium, an electronically stable Li-e+^+ ground state

Calculations of the positron-Li system were performed using the Stochastic Variational Method and yielded a minimum energy of -7.53208 Hartree for the L=0 ground state. Unlike previous calculations of this system, the system was found to be stable against dissociation into the Ps + Li$^+$ channel with a binding energy of 0.00217 Hartree and is therefore electronically stable. This is the first instance of a rigorous calculation predicting that it is possible to combine a positron with a neutral atom and form an electronically stable bound state.Comment: 11 pages, 2 tables. To be published in Phys.Rev.Let

Natural Toxins for Use in Pest Management

Natural toxins are a source of new chemical classes of pesticides, as well as environmentally and toxicologically safer molecules than many of the currently used pesticides. Furthermore, they often have molecular target sites that are not exploited by currently marketed pesticides. There are highly successful products based on natural compounds in the major pesticide classes. These include the herbicide glufosinate (synthetic phosphinothricin), the spinosad insecticides, and the strobilurin fungicides. These and other examples of currently marketed natural product-based pesticides, as well as natural toxins that show promise as pesticides from our own research are discussed

Notes on Lithology, Mineralogy, and Production for Lunar Simulants

The creation of lunar simulants requires a very broad range of specialized knowledge and information. This document covers several topic areas relevant to lithology, mineralogy, and processing of feedstock materials that are necessary components of the NASA lunar simulant effort. The naming schemes used for both terrestrial and lunar igneous rocks are discussed. The conflict between the International Union of Geological Sciences standard and lunar geology is noted. The rock types known as impactites are introduced. The discussion of lithology is followed by a brief synopsis of pyroxene, plagioclase, and olivine, which are the major mineral constituents of the lunar crust. The remainder of the text addresses processing of materials, particularly the need for separation of feedstock minerals. To illustrate this need, the text includes descriptions of two norite feedstocks for lunar simulants: the Stillwater Complex in Montana, United States, and the Bushveld Complex in South Africa. Magnetic mineral separations, completed by Hazen Research, Inc. and Eriez Manufacturing Co. for the simulant task, are discussed