Parametric study of beam refraction problems across laser anemometer windows

The experimenter is often required to view flows through a window with a different index of refraction than either the medium being observed or the medium that the laser anemometer is immersed in. The refraction that occurs at the window surfaces may lead to undesirable changes in probe volume position or beam crossing angle and can lead to partial or complete beam uncrossing. This report describes the results of a parametric study of this problem using a ray tracing technique to predict these changes. The windows studied were a flat plate and a simple cyclinder. For the flat-plate study: (1) surface thickness, (2) beam crossing angle, (3) bisecting line - surface normal angle, and (4) incoming beam plane surface orientation were varied. For the cylindrical window additional parameters were also varied: (1) probe volume immersion, (2) probe volume off-radial position, and (3) probe volume position out of the R-theta plane of the lens. A number of empirical correlations were deduced to aid the interested reader in determining the movement, uncrossing, and change in crossing angle for a particular situation

Effects of Herbicide-Resistant Technology Fees on the Plant Population Decision for Cotton Production

This study evaluated effects on cotton net revenues of four herbicide-resistant technology policies used since 1996 by Monsanto. Results indicate that farmers may have an incentive to switch from narrow-row to wide-row cotton and to use a lower plant density when the technology fee is tied to the seeding rate.Farm Management,

Performance of a tandem-rotor/tandem-stator conical-flow compressor designed for a pressure ratio of 3

A conical-flow compressor stage with a large radius change through the rotor was tested at three values of rotor tip clearance. The stage had a tandem rotor and a tandem stator. Peak efficiency at design speed was 0.774 at a pressure ratio of 2.613. The rotor was tested without the stator, and detailed survey data were obtained for each rotor blade row. Overall peak rotor efficiency was 0.871 at a pressure ratio of 2.952

OPTIMAL PLANT POPULATION FOR ULTRA-NARROW-ROW COTTON PRODUCTION AS INFLUENCED BY LINT AND TRANSGENIC SEED PRICES

Farmers are concerned about the high costs of transgenic seed and technology fees associated with the large plant population densities recommended for ultra-narrow row cotton. This study evaluated the effects of alternative plant population density decision criteria on net revenues under different lint price and transgenic seed cost scenarios. Results indicate that farmers may be able to maximize profits by seeding for a target plant population density of approximately 15.5 plants m-2.Crop Production/Industries,

Digital computer simulation of inductor-energy-storage dc-to-dc converters with closed-loop regulators

The simulation of converter-controller combinations by means of a flexible digital computer program which produces output to a graphic display is discussed. The procedure is an alternative to mathematical analysis of converter systems. The types of computer programming involved in the simulation are described. Schematic diagrams, state equations, and output equations are displayed for four basic forms of inductor-energy-storage dc to dc converters. Mathematical models are developed to show the relationship of the parameters

Is Targeting Formal Childcare the Best Way to Meet the Needs of Families in Britain?

The overall aim of this paper is to examine the types and combinations of childcare being used by parents in Britain, and to compare how this childcare usage may vary between families, in order to critically examine parental childcare needs. The three specific research questions were: 1) ‘What types and combinations of childcare are being used by families?’, 2) ‘What are the socio-demographic comparisons between families using and not using childcare?’ And 3) ‘How do types of childcare vary between families?. These questions were addressed by carrying out a secondary analysis of large-scale nationally representative datasets which provide information about patterns of childcare usage in the UK. Two main datasets were used: the Family Resources Survey and the Childcare and Early Years Survey of Parents, with analysis carried out for the years 2008 to 2013. The analysis carried out comes from a wider study seeking to examine the provision and use of preschool childcare in Britain. The findings show that despite policies to increase the use of formal childcare, parents continue to be reliant on informal care, especially grandparents, to supplement their childcare needs. Furthermore, childcare use is not equally distributed, but is related to family circumstances. For example formal care is used more by employed, higher income families, whilst informal care is used more by mothers who are not employed, less well educated and by younger mothers. The results overall suggest that formal and informal childcare in combination will better support maternal employment. Future government policy needs to address supporting this mixed provision. The data however says nothing about parental childcare preferences which are needed to unpack the observed patterns of childcare usage in the UK

How Much Longer Will it Take? A Ten-year Review of the Implementation of United Nations General Assembly Resolutions 61/105, 64/72 and 66/68 on the Management of Bottom Fisheries in Areas Beyond National Jurisdiction

The United Nations General Assembly (UNGA) in 2002 adopted the first in a series of resolutions regarding the conservation of biodiversity in the deep sea. Prompted by seriousconcerns raised by scientists, non-governmental organizations (NGOs) and numerous States,these resolutions progressively committed States to act both individually and through regional fishery management organizations (RFMOs) to either manage bottom fisheries in areas beyond national jurisdiction to prevent significant adverse impacts on deep-sea species, ecosystems and biodiversity or else prohibit bottom fishing from taking place.Ten years have passed since the adoption of resolution 61/105 in 2006, calling on States to take a set of specific actions to manage bottom fisheries in areas beyond national jurisdiction to protect vulnerable marine ecosystems (VMEs) from the adverse impacts of bottom fishing and ensure the sustainability of deep-sea fish stocks. Despite the considerable progress by some RFMOs, there remain significant gaps in the implementation of key elements and commitments in the resolutions. The Deep Sea Conservation Coalition (DSCC) has prepared this report to assist the UNGA in its review in 2016 and to address the following question: How effectively have the resolutions been implemented