Characterisation of the corrosion of iron using a smartphone camera

Smartphone technology provides bountiful opportunities for greater participation in scientific and technological research and monitoring. Digital camera image sensors have been used for the detection, measurement and monitoring of rust, this research extends that capability to the smartphone. It has been observed that as rust content increases in a clean iron sample, red responses decrease proportionally. Green and blue responses quantifiably decrease faster, matching the observed overall reddening as rust proportion increased. Potential noise sources due to the variable texture of the rusted samples had a negligible effect on the results. The effectiveness of this method for the characterisation of a smartphone image sensor response to the amount of iron corrosion is reflected in the congruent validation tests and errors never exceeding 5%. These results demonstrate that the smartphone can be used as a low cost and efficient means of evaluating the percentage of surface rust content

Students as toolmakers: refining the results in the accuracy and precision of a trigonometric activity

Smartphones used as tools provides opportunities for the teaching of the concepts of accuracy and precision and the mathematical concept of arctan. The accuracy and precision of a trigonometric experiment using entirely mechanical tools is compared to one using electronic tools, such as a smartphone clinometer application and a laser pointer. This research has demonstrated how two classroom activities based on tool making can enhance student measurement and application of accuracy and precision considerations through a trigonometric activity investigating arctan

Characterization of cloud cover with a smartphone camera

A smartphone sky camera and associated image analysis algorithm has been developed and validated for the determination of the percentage of cloud cover. This provides the total cloud cover and the percentage of thick and thin cloud in the image. The system has been validated and tested using supervised image classification for a range of cloud types and cloud cover ranging from 4% to 98% and solar zenith angles between 6o and 49o. Additionally, this system provides the percentage of total cloud and thick and thin cloud in proximity to the solar disc. The size of the errors is comparable to those associated with the cloud fractions determined with commercial sky camera systems. The benefits of increasing the availability of cloud fraction measurements through the system described include the potential to develop improved local ultraviolet index and weather forecasts and contribute toward better understanding of local trends in cloud patterns that is required to be considered in the generation of solar energy

Transonic Aerodynamic Loading Characteristics of a Wing-Body-Tail Combination Having a 52.5 deg. Sweptback Wing of Aspect Ratio 3 With Conical Wing Camber and Body Indentation for a Design Mach Number of Square Root of 2

An investigation has been made of the effects of conical wing camber and body indentation according to the supersonic area rule on the aerodynamic wing loading characteristics of a wing-body-tail configuration at transonic speeds. The wing aspect ratio was 3, taper ratio was 0.1, and quarter-chord-line sweepback was 52.5 deg. with 3-percent-thick airfoil sections. The tests were conducted in the Langley 16-foot transonic tunnel at Mach numbers from 0.80 to 1.05 and at angles of attack from 0 deg. to 14 deg., with Reynolds numbers based on mean aerodynamic chord varying from 7 x 10(exp 6) to 8 x 10(exp 6). Conical camber delayed wing-tip stall and reduced the severity of the accompanying longitudinal instability but did not appreciably affect the spanwise load distribution at angles of attack below tip stall. Body indentation reduced the transonic chordwise center-of-pressure travel from about 8 percent to 5 percent of the mean aerodynamic chord

Broadband direct UVA irradiance measurement for clear skies evaluated using a smartphone

UVA wavelengths (320-400 nm) have been implicated in recent studies to contribute to melanoma induction and skin photoaging in humans and damage to plants. The use of smartphones in UVA observations are a way to supplement measurements made by traditional radiometric and spectroradiometric technology. Although the smartphone image sensor is not capable of determining broadband UVA irradiances, these can be reconstructed from narrowband irradiances, which the smartphone, with narrowband and neutral density filters, can quantify with discrepancies not exceeding 5%. Three models that reconstruct direct broadband clear sky UVA were developed from narrowband irradiances derived from smartphone image sensor pixel data with coefficients of determination of between 0.97 and 0.99. Reasonable accuracy and precision in determining the direct broadband UVA was maintained for observations made with solar zenith angles as high as 70°. The developed method has the potential to increase the uptake of the measurement of broadband UVA irradiances

Description of 0.186-scale model of high-speed duct of national transonic facility

The National Transonic Facility (NTF) is a pressurized cryogenic wind tunnel with a 2.5 m square test section. A 0.186-scale model of the NTF was used to simulate the aerodynamic performance of the components of the high-speed duct of the NTF. These components consist of a wide-angle diffuser, settling chamber, contraction section, test section, model support section, and high-speed diffuser. The geometry of the model tunnel, referred to as the diffuser flow apparatus is described, and some of its operating characteristics are presented

Solar current output as a function of sun elevation: students as toolmakers

Solar current is an increasingly important aspect of modern life and will be even more so crucial in the students’ future. Encouraging students to be the ‘toolmakers’ allows students to take ownership of scientific investigations, as well as forcing them to refine their research questions and hypothesis the design and refinement of their tools. The modern day has seen an unprecedented opportunity for toolmaking, in the form of adapting and programming apps that use the micro-electro-mechanical sensors that are an intrinsic part of smartphone technology. A sample in-class experiment and an experimental investigation are presented; these represent an increase in toolmaking and student ownership with a corresponding decrease in teacher guidance. Toolmaking progresses from the construction of a physical sunspotter, using a hand lens and cut-off tube, using apps, to future considerations such as programming, adapting pre-existing code samples to be able to manipulate the smartphone sensors

Towards a synthesized critique of neoliberal biodiversity conservation

During the last three decades, the arena of biodiversity conservation has largely aligned itself with the globally dominant political ideology of neoliberalism and associated governmentalities. Schemes such as payments for ecological services are promoted to reach the multiple ‘wins’ so desired: improved biodiversity conservation, economic development, (international) cooperation and poverty alleviation, amongst others. While critical scholarship with respect to understanding the linkages between neoliberalism, capitalism and the environment has a long tradition, a synthesized critique of neoliberal conservation - the ideology (and related practices) that the salvation of nature requires capitalist expansion - remains lacking. This paper aims to provide such a critique. We commence with the assertion that there has been a conflation between ‘economics’ and neoliberal ideology in conservation thinking and implementation. As a result, we argue, it becomes easier to distinguish the main problems that neoliberal win-win models pose for biodiversity conservation. These are framed around three points: the stimulation of contradictions; appropriation and misrepresentation and the disciplining of dissent. Inspired by Bruno Latour’s recent ‘compositionist manifesto’, the conclusion outlines some ideas for moving beyond critique

Ground characterisation for PISA pile testing and analysis

This paper is the first of a set of linked publications on the PISA Joint Industry Research Project, which was concerned with the development of improved design methods for monopile foundations in offshore wind applications. PISA involved large-scale pile tests in overconsolidated glacial till at Cowden, north-east England, and in dense, normally consolidated marine sand at Dunkirk, northern France. The paper presents the characterisation of the two sites, which was crucial to the design of the field experiments and advanced numerical modelling of the pile–soil interactions. The studies described, which had to be completed at an early stage of the PISA project, added new laboratory and field campaigns to historic investigations at both sites. They enabled an accurate description of soil behaviour from small strains to ultimate states to be derived, allowing analyses to be undertaken that captured both the serviceability and limit state behaviour of the test monopiles