Improved photovoltaic performance of CdSe/CdS/PbS quantum dot sensitized ZnO nanorod array solar cell

Single crystalline zinc oxide (ZnO) nanorod array has been used for the fabrication of CdSe/CdS/PbS/ZnO quantum dot sensitized solar cell (QDSSC). The ZnO nanorod array photoanodes are sensitized with consecutive layer of PbS, CdS and CdSe quantum dots by employing simple successive ion layer adsorption and reaction (SILAR) and chemical bath deposition (CBD) techniques. The performances of the QDSSCs are examined in detail using polysulfide electrolyte with copper sulfide (CuS) counter electrode. The combination of two successive layers of PbS with CdSe/CdS/ZnO shows an improved short circuit current density (12.223 mA cm(-2)) with a maximum power to conversion efficiency of 2.352% under 1 sun illumination. This enhancement is mainly attributed due to the better light harvesting ability of the PbS quantum dots and make large accumulation of photo-injected electrons in the conduction band of ZnO, and CdSe/CdS layers lower the recombination of photo-injected electrons with the electrolyte, these are well evidenced with the photovoltaic studies and electrochemical impedance spectroscopy. (C) 2013 Elsevier B.V. All rights reserved.

Synthesis of self-light-scattering wrinkle structured ZnO photoanode by sol-gel method for dye-sensitized solar cells

A special morphological zinc oxide (ZnO) photoanode for dye-sensitized solar cell was fabricated by simple sol-gel drop casting technique. This film shows a wrinkled structure resembling the roots of banyan tree, which acts as an effective self scattering layer for harvesting more visible light and offers an easy transport path for photo-injected electrons. These ZnO electrode of low thickness (similar to 5 mu m) gained an enhanced short-circuit current density of 6.15 mA/cm(2), open-circuit voltage of 0.67 V, fill factor of 0.47 and overall conversion efficiency of 1.97 % under 1 sun illumination. This shows a high conversion efficiency and a superior performance than that of ZnO nanoparticle-based photoanode (eta similar to 1.13 %) of high thickness (similar to 8 mu m).

Boron doped defective graphene as a potential anode material for Li-ion batteries

Graphene with large surface area and robust structure has been proposed as a high storage capacity anode material for Li ion batteries. While the inertness of pristine graphene leads to better Li kinetics, poor adsorption leads to Li clustering, significantly affecting the performance of the battery. Here, we show the role of defects and doping in achieving enhanced adsorption without compromising on the high diffusivity of Li. Using first principles density functional theory (DFT) calculations, we carry out a comprehensive study of diffusion kinetics of Li over the plane of the defective structures and calculate the change in the number of Li atoms in the vicinity of defects, with respect to pristine graphene. Our results show that the Li-C interaction, storage capacity and the energy barriers depend sensitively on the type of defects. The un-doped and boron doped mono-vacancy, doped di-vacancy up to two boron, one nitrogen doped di-vacancy, and Stone-Wales defects show low energy barriers that are comparable to pristine graphene. Furthermore, boron doping at mono-vacancy enhances the adsorption of Li. In particular, the two boron doped mono-vacancy graphene shows both a low energy barrier of 0.31 eV and better adsorption, and hence can be considered as a potential candidate for anode material.

Pressure induced manifold enhancement of Li-kinetics in FCC fullerene

The reduction of the diffusion energy barrier for Li in electrodes is one of the required criteria to achieve better performances in Li ion batteries. Using density functional theory based calculations, we report a pressure induced manifold enhancement of Li-kinetics in bulk FCC fullerene. Scanning of the potential energy surface reveals a diffusion path with a low energy barrier of 0.62 eV, which reduces further under the application of hydrostatic pressure. The pressure induced reduction in the diffusion barrier continues till a uniform volume strain of 17.7% is reached. Further enhancement of strain increases the barrier due to the repulsion caused by C-C bond formation between two neighbouring fullerenes. The decrease in the barrier is attributed to the combined effect of charge transfer triggered by the enhanced interaction of Li with the fullerene as well as the change in profile of the local potential, which becomes more attractive for Li. The lowering of the barrier leads to an enhancement of two orders of magnitude in Li diffusivity at room temperature making pressurized bulk fullerene a promising artificial solid electrolyte interface (SEI) for a faster rechargeable battery.

Forcing of self-excited round jet diffusion flames

In this experimental and numerical study, two types of round jet are examined under acoustic forcing. The first is a non-reacting low density jet (density ratio 0.14). The second is a buoyant jet diffusion flame at a Reynolds number of 1100 (density ratio of unburnt fluids 0.5). Both jets have regions of strong absolute instability at their base and this causes them to exhibit strong self-excited bulging oscillations at welldefined natural frequencies. This study particularly focuses on the heat release of the jet diffusion flame, which oscillates at the same natural frequency as the bulging mode, due to the absolutely unstable shear layer just outside the flame. The jets are forced at several amplitudes around their natural frequencies. In the non-reacting jet, the frequency of the bulging oscillation locks into the forcing frequency relatively easily. In the jet diffusion flame, however, very large forcing amplitudes are required to make the heat release lock into the forcing frequency. Even at these high forcing amplitudes, the natural mode takes over again from the forced mode in the downstream region of the flow, where the perturbation is beginning to saturate non-linearly and where the heat release is high. This raises the possibility that, in a flame with large regions of absolute instability, the strong natural mode could saturate before the forced mode, weakening the coupling between heat release and incident pressure perturbations, hence weakening the feedback loop that causes combustion instability. © 2009 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

FTT-MA: A Flexible Time-Triggered Middleware Architecture for Time Sensitive, Resource-Aware AmI Systems

There is an increasing number of Ambient Intelligence (AmI) systems that are time-sensitive and resource-aware. From healthcare to building and even home/office automation, it is now common to find systems combining interactive and sensing multimedia traffic with relatively simple sensors and actuators (door locks, presence detectors, RFIDs, HVAC, information panels, etc.). Many of these are today known as Cyber-Physical Systems (CPS). Quite frequently, these systems must be capable of (1) prioritizing different traffic flows (process data, alarms, non-critical data, etc.), (2) synchronizing actions in several distributed devices and, to certain degree, (3) easing resource management (e.g., detecting faulty nodes, managing battery levels, handling overloads, etc.). This work presents FTT-MA, a high-level middleware architecture aimed at easing the design, deployment and operation of such AmI systems. FTT-MA ensures that both functional and non-functional aspects of the applications are met even during reconfiguration stages. The paper also proposes a methodology, together with a design tool, to create this kind of systems. Finally, a sample case study is presented that illustrates the use of the middleware and the methodology proposed in the paper.

Strong Strain Hardening in Nanocrystalline Nickel

Low strain hardening has hitherto been considered an intrinsic behavior for most nanocrystalline (NC) metals, due to their perceived inability to accumulate dislocations. In this Letter, we show strong strain hardening in NC nickel with a grain size of 20 nm under large plastic strains. Contrary to common belief, we have observed significant dislocation accumulation in the grain interior. This is enabled primarily by Lomer-Cottrell locks, which pin the lock-forming dislocations and obstruct islocation. motion. These observations may help with developing strong and ductile NC metals and alloys.

Chesapeake and Delaware Canal Affects Environmental: presented at American Society of Civil Engineers National Water Resources Engineering Meeting, Phoenix, Arizona, 14 January 1971

The Chesapeake and Delaware Canal is a man-made waterway connecting the upper Chesapeake Bay with the Delaware Bay. It started in 1829 as a private barge canal with locks, two at the Delaware end, and one at the Chesapeake end. For the most part, natural tidal and non-tidal waterways were connected by short dredged sections to form the original canal. In 1927, the C and D Canal was converted to a sea-level canal, with a controlling depth of 14 feet, and a width of 150 feet. In 1938 the canal was deepened to 27 feet, with a channel width of 250 feet. Channel side slopes were dredged at 2.5:1, thus making the total width of the waterway at least 385 feet in those segments representing new cuts or having shore spoil area dykes rising above sea level. In 1954 Congress authorized a further enlargement of the Canal to a depth of 35 feet and a channel width of 450 feet. (pdf contains 27 pages)

Behavior of spherical particles at low Reynolds numbers in a fluctuating translational flow

The behavior of spheres in non-steady translational flow has been studied experimentally for values of Reynolds number from 0.2 to 3000. The aim of the work was to improve our qualitative understanding of particle transport in turbulent gaseous media, a process of extreme importance in power plants and energy transfer mechanisms.

Particles, subjected to sinusoidal oscillations parallel to the direction of steady translation, were found to have changes in average drag coefficient depending upon their translational Reynolds number, the density ratio, and the dimensionless frequency and amplitude of the oscillations. When the Reynolds number based on sphere diameter was less than 200, the oscillation had negligible effect on the average particle drag.

For Reynolds numbers exceeding 300, the coefficient of the mean drag was increased significantly in a particular frequency range. For example, at a Reynolds number of 3000, a 25 per cent increase in drag coefficient can be produced with an amplitude of oscillation of only 2 per cent of the sphere diameter, providing the frequency is near the frequency at which vortices would be shed in a steady flow at the mean speed. Flow visualization shows that over a wide range of frequencies, the vortex shedding frequency locks in to the oscillation frequency. Maximum effect at the natural frequency and lock-in show that a non-linear interaction between wake vortex shedding and the oscillation is responsible for the increase in drag.

Summary document of the work being done in 1992-1993 regarding the migratory salmonid fisheries of the River Ribble catchment

This document lists the work on salmonid fisheries in the River Ribble catchment in the north west of England which was done in 1992-93. The document includes the following: analysis of historical catch data from the River Ribble covering 1937-1991; Ribble and Hodder stock assessment surveys 1992-93 including Swanside Beck; Ribble catch data from game angling log books 1993; results of salmon scale sampling 1993; results of microtagging programme in Hodder and Ribble 1993; Waddow Weir dish counter data 1993; Winkley Hall (Hodder), Locks Weir and Waddow Hall (Ribble) fish counter data 1993; number of fish and ova from Witcherwell Hatchery 1993.

South Lancashire Fisheries Advisory Committee 19th October, 1977

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 19th October, 1977. It covers fisheries income and expenditure, licence duties, fishing regulations, and information on the pollution of Stock Beck. It also comments on the report by the area fisheries officer on fisheries activities which includes information on fish movement and angling for salmon, sea trout, brown trout and coarse fish. Included in this report is also the numbers of fish passing through counting stations from January to August 1977 at Waddow Weir, Winckley Hall and Locks Weir, poaching, fish mortalities, stock numbers and an update on Holmwrangle hatchery. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South Lancashire Fisheries Advisory Committee 11th January, 1978

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 11th January, 1978. It covers information of fisheries income and expenditure, licence duties, regional water resources study, Worthington reservoirs regarding fishery regulations and radioactive discharge in relation to fishery interests. It also includes the report by the area fisheries officer on river conditions and fishing for salmon, sea trout, brown trout and coarse fish, numbers of migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir, and Langcliffe Hatchery. Included in this report is also a brief note on fish disease in salmon in the Ribble and Hodder, and the improvement of Stock Beck after the pollution incident. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South Lancashire Fisheries Advisory Committee 5th April, 1978

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 5th April, 1978. It covers information on fisheries income and expenditure, net licence duties and the concern over the growning population of the feral mink. It also includes the report by the area fisheries officer on river conditions and fishing, and migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir. Included in this report is an update on Langcliffe hatchery, the stocking of brown trout and rainbow trout by the Water Authority and Angling Associations, and fish mortality and fish disease. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South Lancashire Fisheries Advisory Committee 12th January 1977.

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 12th January 1977. The report contains sections on fish mortalities at Henthorn on the 10th July, 1976, fisheries activities, fish stocking, eel fishing on estuarial waters, and infectious Pancreatic Necrosis highlighting its prevention on imports of salmonid fish and ova. The section on fish mortalities looks at fish deaths on the River Ribble caused by a discharge from Clitheroe Sewage Works. The report on fisheries activities includes information on artificial propagation and numbers of fish passing through Waddow Weir, Winckley Hall and Locks Weir between January to November 1976. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

South Lancashire Fisheries Advisory Committee 18th October, 1978

This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 18th October, 1978. It covers information on fisheries income and expenditure, the study of salmon propagation in England and Wales, work on the future programme of fisheries work and keep nets. Other sections include the report on the effects of Barnoldswick STW on Stock Beck and the River Ribble, information on the Leeds/Liverpool Canal transfer of mine water from Bickershaw Colliery and the future fishing policy of Worthington Reservoir. It also covers the report by the area fisheries officer on fishing activities including river conditions and fishing for salmon, sea trout, and coarse fish, and an update on Langcliffe hatchery. The report also looks at migratory fish movements at Waddow Weir, Winckley Hall and Locks Weir, stocking numbers of brown trout, rainbow trout and coarse fish in various rivers, pollution incidents and fish mortalities. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.