Structures of energy spectrum and persistent currents in mesoscopic rings with radial potential barrier in magnetic field

The energy spectrum and the persistent currents are calculated for finite-width mesoscopic annular structures with radial potential barrier in the presence of a magnetic field. The introduction of the tunneling barrier leads to the creation of extra edge states around the barrier and the occurrence of oscillatory structures superimposed on the bulk Landau level plateaus in the energy spectrum. We found that the Fermi energy E-F increases with the number of electrons N emerging many kinks. The single eigenstate persistent current exhibits complicated structures with vortex-like texture, ''bifurcation'', and multiple ''furcation'' patterns as N is increased. The total currents versus N display wild fluctuations.

The mechanism of energy loss and transition in a flow with submerged vegetation

The mechanism of energy balance in an open-channel flow with submerged vegetation was investigated. The energy borrowed from the local flow, energy spending caused by vegetation drag and flow resistance, and energy transition along the water depth were calculated on the basis of the computational results of velocity and Reynolds stress. Further analysis showed that the energy spending in a cross-section was a maximum around the top of the vegetation, and its value decreased progressively until reaching zero at the flume bed or water surface. The energy borrowed from the local flow in the vegetated region could not provide for spending; therefore, surplus borrowed energy in the non-vegetated region was transmitted to the vegetated region. In addition, the total energy transition in the cross-section was zero; therefore, the total energy borrowed from the flow balanced the energy loss in the whole cross-section. At the same time, we found that there were three effects of vegetation on the flow: turbulence restriction due to vegetation, turbulence source due to vegetation and energy transference due to vegetation, where the second effect was the strongest one. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved.

NEW METHODOLOGY FOR THE ESTIMATION OF ENERGY CONSUMPTION IN A DOUBLE-TUBE-SOCKET (DTS (R)) PNEUMATIC CONVEYING

A new methodology based on the use of CFD is proposed to estimate the energy consumptions in a DTS (DOUBLE-TUBE-SOCKET) pneumatic conveying. A simple computational program based on this methodology is developed. It can directly give the lowest energy consumption and the compatible gas consumption by only input the distance of conveying and the conveying tonnage. This computational program has been validated through our experimental work.

Barycenter of energy of lanthanide 4f(N)-(1)5d configuration in inorganic crystals

A semiempirical method for the evaluation of the barycenter of energy of 4f(N-1)5d configurations is presented. The environmental factors affecting the barycenter are given to be the bond volume polarization, fractional covalence of the chemical bond between the central ion and the nearest anion, and presented charge of the nearest anion in the chemical bonds. The barycenter energies of 4f(N-1)5d configurations of Eu2+ and Ce3+ are calculated in various crystals, and the results are in good agreement with the experimental values. A relationship is found between the barycenter of energy of the 4f(N-1)5d configuration on Eu2+ method offers the advantage of applicability to a broad class of luminescence materials and initiates a link between macroscopic properties and microscopic structure.

Study of energy transfer between rare earth ions in CaS host by photoluminescence spectra

When CaS:Sm3+, Eu2+ is excited at 476.5 nm (Ar+), the emission spectra taken at room temperature and at 77 K are different, indicating that there are two competitive energy transfer processes-Sm3+ --> Eu2+ and Eu2+ --> Sm3+ with phonon participation. So, the luminescence intensity of Sm3+ increases first, and then decreases as the concentration of Eu2+ is increasing. (C) 2001 Elsevier Science Ltd. All rights reserved.

Study of energy transfer in KMgF3 : Eu-X (X = Gd, Cr, Ce) by the decay model of P-6(7/2) exited state of Eu2+

Energy transfer processes between Eu2+ and Gd3+, Cr3+, Ce3+ ions in KMgF3, which are difficult to study spectroscopically, have been investigated by using the proposed four-level decay model of the P-6(7/2) excited state of the Eu2+ ion. Gd3+ and Ce3+ transfer its energy to the vibronic transition of the P-6(7/2) --> S-8(7/2) transition of Eu2+, whereas Cr3+ receive energy from Eu2+ via the d-d interaction. The energy transfer from the Eu2+ 4f(6)5d level to the Ce3+ 4f5d state is observed spectroscopically, and the energy transfer mechanism is discussed. (C) 2001 Elsevier Science B.V. All rights reserved.

Comparative studies on the efficiency of energy transfer of two R-phycoerythrin-C-phycocyanin conjugates constructed from sodium periodate and glutaraldehyde respectively

The C-phycocyanin and the R-phycoerythrin were purified from the blue-green alga Spirulina platensis and red alga Polysiphonia urceolata respectively. Both sodium periodate and glutaraldehyde are effective coupling agents being capable of constructing the R-phycoerythrin-C-phycocyanin conjugate, which was also called phycobiliproteins energy transfer model. The two artificial conjugates constructed with different methods were purified by Sephadex G-200 chromatography respectively. Spectra analysis indicated that energy transfer occurred in the two conjugates. The conjugate with sodium periodate had the higher efficiency of energy transfer than that with glutaraldehyde conjugate.

Livestock grazing, plateau pikas and the conservation of avian biodiversity on the Tibetan plateau

On the Qinghai-Tibet plateau increased livestock numbers have resulted in degradation of the grasslands with potential impacts on native biodiversity. Concurrently, perceived increases in populations of native small mammals such as plateau pikas (Ochotona curzoniae) have led to poisoning programs, with uncertain impacts on species such as ground-nesting birds. We explored the relationships between the local seasonal abundance of small birds and (1) the density of pika burrows; (2) livestock grazing practices; and (3) local poisoning of pikas. Around Naqu prefecture, central Tibet, we used a nested experimental design to collect data from areas rested from grazing over summer, nearby areas with year-round grazing and areas subjected to pika poisoning. Additional data were collected from a site where grazing had not occurred for at least 4 years prior to the study. Poisoning pikas in spring had no detectable effect on the local abundance of birds the following autumn. However, two ground-nesting species, white-rumped and rufous-necked snowfinches, showed positive associations with the density of pika burrows, indicating that long-term 'pika poisoning could reduce the density of these species by reducing the density of pika burrows. Rufous-necked snowfinches and non ground-nesting species including horned larks and common hoopoes showed positive responses to reduced grazing pressure from livestock, particularly in the long-rested site, indicating current grazing levels could be having a negative impact on these species. Conservation of small passerine biodiversity in this system will require changed management practices for livestock and pikas that consider the complex three-way interaction between livestock grazing, pikas and small birds. (C) 2008 Elsevier Ltd. All rights reserved.

Bottom-up modelling of energy demand and technical energy savings potential in the Irish residential sector

The International Energy Agency has repeatedly identified increased end-use energy efficiency as the quickest, least costly method of green house gas mitigation, most recently in the 2012 World Energy Outlook, and urges all governing bodies to increase efforts to promote energy efficiency policies and technologies. The residential sector is recognised as a major potential source of cost effective energy efficiency gains. Within the EU this relative importance can be seen from a review of the National Energy Efficiency Action Plans (NEEAP) submitted by member states, which in all cases place a large emphasis on the residential sector. This is particularly true for Ireland whose residential sector has historically had higher energy consumption and CO2 emissions than the EU average and whose first NEEAP targeted 44% of the energy savings to be achieved in 2020 from this sector. This thesis develops a bottom-up engineering archetype modelling approach to analyse the Irish residential sector and to estimate the technical energy savings potential of a number of policy measures. First, a model of space and water heating energy demand for new dwellings is built and used to estimate the technical energy savings potential due to the introduction of the 2008 and 2010 changes to part L of the building regulations governing energy efficiency in new dwellings. Next, the author makes use of a valuable new dataset of Building Energy Rating (BER) survey results to first characterise the highly heterogeneous stock of existing dwellings, and then to estimate the technical energy savings potential of an ambitious national retrofit programme targeting up to 1 million residential dwellings. This thesis also presents work carried out by the author as part of a collaboration to produce a bottom-up, multi-sector LEAP model for Ireland. Overall this work highlights the challenges faced in successfully implementing both sets of policy measures. It points to the wide potential range of final savings possible from particular policy measures and the resulting high degree of uncertainty as to whether particular targets will be met and identifies the key factors on which the success of these policies will depend. It makes recommendations on further modelling work and on the improvements necessary in the data available to researchers and policy makers alike in order to develop increasingly sophisticated residential energy demand models and better inform policy.

ANALYSIS AND SIMULATION OF ENERGY USE AND COST AT A MUNICIPAL WASTEWATER TREATMENT PLANT

The cost of electricity, a major operating cost of municipal wastewater treatment plants, is related to influent flow rate, power price, and power load. With knowledge of inflow and price patterns, plant operators can manage processes to reduce electricity costs. Records of influent flow, power price, and load are evaluated for Blue Plains Advanced Wastewater Treatment Plant. Diurnal and seasonal trends are analyzed. Power usage is broken down among treatment processes. A simulation model of influent pumping, a large power user, is developed. It predicts pump discharge and power usage based on wet-well level. Individual pump characteristics are tested in the plant. The model accurately simulates plant inflow and power use for two pumping stations [R2 = 0.68, 0.93 (inflow), R2 =0.94, 0.91(power)]. Wet-well stage-storage relationship is estimated from data. Time-varying wet-well level is added to the model. A synthetic example demonstrates application in managing pumps to reduce electricity cost.

The future of energy: are competitive markets and nuclear power the answer?

The inaugural lecture of Professor Stephen Thomas at the University of Greenwich, 4th February 2010. It examines whether further pursuit of competition in energy markets and expansion in the role of nuclear power can be the main elements in a policy to meet goals of security, sustainability and affordability.

Aerobic Metabolism Octopine Production And Phosphoarginine As Sources Of Energy In The Phasic And Catch Adductor Muscles Of The Giant Scallop Placopecten-Magellanicus During Swimming And The Subsequent Recovery Period

1. The energy contributions of aerobic metabolism, phosphoarginine, ATP and octopine in the adductor muscles of P. magellanicus were examined during swimming and recovery. 2. A linear relationship was observed between the size of the phosphoarginine pool and the number of valve snaps. A linear increase in arginine occurred during the same period. 3. 3. Octopine was formed during the first few hours of recovery, particularly in the phasic muscle. 4. The restoration of the phosphoarginine pool appeared to be by aerobic metabolism. 5. It is concluded that the role of octopine formation is to supply energy when the tissues are anoxic and to operate at such a rate as to maintain the basal rate of energy production.