Transboundary diagnostic analysis. Vol. 1. Issues, proximate and root causes

The Transboundary Diagnostic Analysis(TDA) quantifies and ranks water-related environmental transboundary issues and their causes according to the severity of environmental and/or socio-economic impacts. The three main issues in BOBLME are; overexploitation of marine living resources; degradation of mangroves, coral reefs and seagrasses; pollution and water quality. Volume 1 describes the transboundary issues in BOBLME and their proximate and underlying root causes. These will be used to develop a Strategic Action Plan (SAP)

Transboundary diagnostic analysis. Vol. 2. Background and environmental assessment

The Transboundary Diagnosis Analysis(TDA) quantifies and ranks water-related environmental transboundary issues and their causes according to the severity of environmental and/or socio-economic impacts. The three main issues in BOBLME are; overexploitation of marine living resources; degradation of mangroves, coral reefs and seagrasses; pollution and water quality. Volume 2 contains background material that sets out the bio-physical and socio-economic characteristics of the BOBLME; an analysis of the legal,policy and administrative context; and an assessment of the status of marine living resources and marine environment in coastal areas

Extraction, purification and analysis of conotoxin of Conus textile captured from Persian Gulf and the investigation of analgesic effects of conotoxins in an animal model

Identification of venomous species of Persian Gulf cone snails and characterization of venom composition and their features is so important from the point of medical importance. Marine cone snails from the genus Conus are estimated to consist of up to 700 species. The venom of cone snails has yielded a rich source of novel neuroactive peptides or conotoxins. The present study was aimed to study the analgesic effect of Persian Gulf Conus textile and its comparison with morphine in mouse model. The specimens of Conus textile were collected of Larak Island from depth of 7 m. The collected samples were transferred to laboratory alive and were stored at -700 c. he veno s ducts were separated and ho ogenized with deionized water he ixture centrifuged at rp for inutes upernatant was considered as extracted veno and stored at - C after lyophylization. The protein profile of venom determined by using SDS-PAGE and HPLC used to investigate the extracted venom and to evaluate the analgesic activity, formalin test was carried out. SDS-PAGE indicated several bands ranged between 6 and 250 kDa. Chromatogram of the venom demonstrated more than 44 large and small fractions. The amount of 10 ng of Conus crude venom and analgesic peptide showed the best anti-pain activity in formalin test. No death observed up to 100 mg/kg, which is 250,000 times higher than the effective dose.Venom characterization of Persian Gulf Conus textile may be of medical importance and potential for new pharmaceutical drugs as well.

Transboundary diagnostic analysis: executive summary

The Transboundary Diagnosis Analysis(TDA) quantifies and ranks water-related environmental transboundary issues and their causes according to the severity of environmental and/or socio-economic impacts. The three main issues in BOBLME are; overexploitation of marine living resources; degradation of mangroves, coral reefs and seagrasses; pollution and water quality.

An analysis of the 1970 commercial fish catch in three areas of the Kafue Floodplain

The commercial landings of fish in three areas of the Kafue Floodplain were examined in regard to thhing technique used, catch per unit effort, and species composition and length size. Gillnets were used throughout the year although predominantly in the wet season, and drawnets (similar to beach seines) were used at periods of low water level. Fishermen used a varying number of gillnets in each area, and the catehes also varied according to month. Principal species caught on the floodplain were clarias gariepinus and Tilapia andersoni. There are indications that, whereas the catch per gillnet in the year's 1965-1970 may be lower than in the 1950s. The drawnet calch per unit of effort of these later years is higher than in the 1950s.

Near-complete transuranic waste incineration in a thorium fuelled pressurised water reactor

The production of long-lived transuranic (TRU) waste is a major disadvantage of fission-based nuclear power. Incineration, and virtual elimination, of waste stockpiles is possible in a thorium (Th) fuelled critical or subcritical fast reactor. Fuel cycles producing a net decrease in TRUs are possible in conventional pressurised water reactors (PWRs). However, minor actinides (MAs) have a detrimental effect on reactivity and stability, ultimately limiting the quality and quantity of waste that can be incinerated. In this paper, we propose using a thorium-retained-actinides fuel cycle in PWRs, where the reactor is fuelled with a mixture of thorium and TRU waste, and after discharge all actinides are reprocessed and returned to the reactor. To investigate the feasibility and performance of this fuel cycle an assembly-level analysis for a one-batch reloading strategy was completed over 125 years of operation using WIMS 9. This one-batch analysis was performed for simplicity, but allowed an indicative assessment of the performance of a four-batch fuel management strategy. The build-up of 233U in the reactor allowed continued reactive and stable operation, until all significant actinide populations had reached pseudo-equilibrium in the reactor. It was therefore possible to achieve near-complete transuranic waste incineration, even for fuels with significant MA content. The average incineration rate was initially around 330 kg per GW th year and tended towards 250 kg per GW th year over several decades: a performance comparable to that achieved in a fast reactor. Using multiple batch fuel management, competitive or improved end-of-cycle burn-up appears achievable. The void coefficient (VC), moderator temperature coefficient (MTC) and Doppler coefficient remained negative. The quantity of soluble boron required for a fixed fuel cycle length was comparable to that for enriched uranium fuel, and acceptable amounts can be added without causing a positive VC or MTC. This analysis is limited by the consideration of a single fuel assembly, and it will be necessary to perform a full core coupled neutronic-thermal-hydraulic analysis to determine if the design in its current form is feasible. In particular, the potential for positive VCs if the core is highly or locally voided is a cause for concern. However, these results provide a compelling case for further work on concept feasibility and fuel management, which is in progress. © 2011 Elsevier Ltd. All rights reserved.

Analysis of the energies of the triple base triplets

Sixty-four sets of three-dimensional models of DNA triplex base triplets (TBT) were built up based on codons by homologous modeling method and their energies were minimized. According to sequence of TBT and orientation of the third ODN strand third, the energies of monomers and water-K+-TBT ternary complexes of TBT were analyzed. The results showed: (i) The energies of the symmetric parallel monomers are generally lower than those of the symmetric anti-parallel monomers of TBT, but the energies of the symmetric parallel ternary complexes are higher than those of the symmetric anti-parallel ternary complexes of TBT. (ii) No matter TBTs are monomers or ternary complexes, the energies of asymmetric parallel TBTs are generally lower than those of the asymmetric anti-parallel ones. (iii) Although the energies of the parallel TBTs are correlated with those of the anti-parallel ones, the energy differences are significant between them. The results here suggest the sequences of TBTs and the orientations of the third ODN strands are two of the key factors that can influence the formation and stability of TBT. (C) 2002 Elsevier Science B.V. All rights reserved.

Study of the turbulence in the air-side and water-side boundary layers in experimental laboratory wind induced surface waves

This study detailed the structure of turbulence in the air-side and water-side boundary layers in wind-induced surface waves. Inside the air boundary layer, the kurtosis is always greater than 3 (the value for normal distribution) for both horizontal and vertical velocity fluctuations. The skewness for the horizontal velocity is negative, but the skewness for the vertical velocity is always positive. On the water side, the kurtosis is always greater than 3, and the skewness is slightly negative for the horizontal velocity and slightly positive for the vertical velocity. The statistics of the angle between the instantaneous vertical fluctuation and the instantaneous horizontal velocity in the air is similar to those obtained over solid walls. Measurements in water show a large variance, and the peak is biased towards negative angles. In the quadrant analysis, the contribution of quadrants Q2 and Q4 is dominant on both the air side and the water side. The non-dimensional relative contributions and the concentration match fairly well near the interface. Sweeps in the air side (belonging to quadrant Q4) act directly on the interface and exert pressure fluctuations, which, in addition to the tangential stress and form drag, lead to the growth of the waves. The water drops detached from the crest and accelerated by the wind can play a major role in transferring momentum and in enhancing the turbulence level in the water side.On the air side, the Reynolds stress tensor's principal axes are not collinear with the strain rate tensor, and show an angle α σ≈=-20°to-25°. On the water side, the angle is α σ≈=-40°to-45°. The ratio between the maximum and the minimum principal stresses is σ a/σ b=3to4 on the air side, and σ a/σ b=1.5to3 on the water side. In this respect, the air-side flow behaves like a classical boundary layer on a solid wall, while the water-side flow resembles a wake. The frequency of bursting on the water side increases significantly along the flow, which can be attributed to micro-breaking effects - expected to be more frequent at larger fetches. © 2012 Elsevier B.V.

Structural and thermodynamic properties of different phases of supercooled liquid water.

Computer simulation results are reported for a realistic polarizable potential model of water in the supercooled region. Three states, corresponding to the low density amorphous ice, high density amorphous ice, and very high density amorphous ice phases are chosen for the analyses. These states are located close to the liquid-liquid coexistence lines already shown to exist for the considered model. Thermodynamic and structural quantities are calculated, in order to characterize the properties of the three phases. The results point out the increasing relevance of the interstitial neighbors, which clearly appear in going from the low to the very high density amorphous phases. The interstitial neighbors are found to be, at the same time, also distant neighbors along the hydrogen bonded network of the molecules. The role of these interstitial neighbors has been discussed in connection with the interpretation of recent neutron scattering measurements. The structural properties of the systems are characterized by looking at the angular distribution of neighboring molecules, volume and face area distribution of the Voronoi polyhedra, and order parameters. The cumulative analysis of all the corresponding results confirms the assumption that a close similarity between the structural arrangement of molecules in the three explored amorphous phases and that of the ice polymorphs I(h), III, and VI exists.

Visualising a stochastic model of California Water Resources Using Sankey Diagrams

This paper describes a novel approach to the analysis of supply and demand of water in California. A stochastic model is developed to assess the future supply of and demand for water resources in California. The results are presented in the form of a Sankey diagram where present and stochastically-varying future fluxes of water in California and its sub-regions are traced from source to services by mapping the various transformations of water from when it is first made available for use, through its treatment, recycling and reuse, to its eventual loss in a variety of sinks. This helps to highlight the connections of water with energy and land resources, including the amount of energy used to pump and treat water, the amount of water used for energy production, and the land resources that create a water demand to produce crops for food. By mapping water in this way, policy-makers can more easily understand the competing uses of water, through the identification of the services it delivers (e.g. sanitation, food production, landscaping), the potential opportunities for improving themanagement of the resource and the connections with other resources which are often overlooked in a traditional sector-based management strategy. This paper focuses on a Sankey diagram for water, but the ultimate aim is the visualisation of linked resource futures through inter-connected Sankey diagrams for energy, land and water, tracking changes from the basic resources for all three, their transformations, and the final services they provide.

Fertile-free fuels in pressurized water reactors: Design challenges and solutions

This paper investigates the basic feasibility of using reactor-grade Pu in fertile-free fuel (FFF) matrix in pressurized water reactors (PWRs). Several important issues were investigated in this work: the Pu loading required to achieve a specific interrefueling interval, the impact of inert matrix composition on reactivity constrained length of cycle, and the potential of utilizing burnable poisons (BPs) to alleviate degradation of the reactivity control mechanism and temperature coefficients. Although the subject was addressed in the past, no systematic approach for assessment of BP utilization in FFF cores was published. In this work, we examine all commercially available BP materials in all geometrical arrangements currently used by the nuclear industry with regards to their potential to alleviate the problems associated with the use of FFF in PWRs. The recently proposed MgO-ZrO2 solid-state solution fuel matrix, which appears to be very promising in terms of thermal properties and radiation damage resistance, was used as a reference matrix material in this work. The neutronic impact of the relative amounts of MgO and ZrO2 in the matrix were also studied. The analysis was performed with a neutron transport and fuel assembly burnup code BOXER. A modified linear reactivity model was applied to the two-dimensional single fuel assembly results to approximate the full core characteristics. Based on the results of the performed analyses, the Pu-loaded FFF core demonstrated potential feasibility to be used in existing PWRs. Major FFF core design problems may be significantly mitigated through the correct choice of BP design. It was found that a combination of BP materials and geometries may be required to meet all FFF design goals. The use of enriched (in most effective isotope) BPs, such as 167Er and 157Gd, may further improve the BP effectiveness and reduce the fuel cycle length penalty associated with their use.

Assessment of homogeneous thorium/uranium fuel for pressurized water reactors

The homogeneous ThO2-UO2 fuel cycle option for a pressurized water reactor (PWR) of current technology is investigated. The fuel cycle assessment was carried out by calculating the main performance parameters: natural uranium and separative work requirements, fuel cycle cost, and proliferation potential of the spent fuel. These performance parameters were compared with a corresponding slightly enriched (all-U) fuel cycle applied to a PWR of current technology. The main conclusion derived from this comparison is that fuel cycle requirements and fuel cycle cost for the mixed Th/U fuel are higher in comparison with those of the all-U fuel. A comparison and analysis of the quantity and isotopic composition of discharged Pu indicate that the Th/U fuel cycle provides only a moderate improvement of the proliferation resistance. Thus, the overall conclusion of the investigation is that there is no economic justification to introduce Th into a light water reactor fuel cycle as a homogeneous ThO2-UO2 mixture.

Use of axially graded burnable boron for hot-spot temperature reduction in a pressurized water reactor core

Shortly after the loading of a pressurized water reactor (PWR) core, the axial power distribution in fresh fuel has already attained the characteristic, almost flat shape, typical of burned fuel. At beginning of cycle (BOC), however, the axial distribution is centrally peaked. In assemblies hosting uniform burnable boron rods, this BOC peaking is even more pronounced. A reduction in the axial peaking is today often achieved by shortening the burnable boron rods by some 30 cm at each edge. It is shown that a two-zone grading of the boron rod leads, in a representative PWR cycle, to a reduction of the hot-spot temperature of approximately 70 °C, compared with the nongraded case. However, with a proper three-zone grading of the boron rod, an additional 20 °C may be cut off the hot-spot temperature. Further, with a slightly skewed application of this three-zone grading, an additional 50 °C may be cut off. The representative PWR cycle studied was cycle 11 of the Indian Point 2 station, with a simplification in the number of fuel types and in the burnup distribution. The analysis was based on a complete three-dimensional burnup calculation. The code system was ELCOS, with BOXER as an assembly code for the generation of burnup-dependent cross sections and SILWER as a three-dimensional core code with thermal-hydraulic feedback.

The dominant role of the solvent-water interface in water droplet templating of polymers

We investigate the formation of microstructured polymer networks known as Breath Figure templated structures created by the presence of water vapour over evaporating polymer solutions. We use a highly controlled experimental approach to examine this dynamic and non-equilibrium process to uniquely compare pure solvent systems with polymer solutions and demonstrate using a combination of optical microscopy, focused ion-beam milling and SEM analysis that the porous polymer microstructure is completely controlled by the interfacial forces that exist between the water droplet and the solvent until a final drying dilation of the imprints. Water droplet contact angles are the same in the presence or absence of polymer and are independent of size for droplets above 5 μm. The polymer acts a spectator that serves to trap water droplets present at the air interface, and to transfer their shape into the polymer film. For the smallest pores, however, there are unexpected variations in the contact angle with pore size that are consistent with a possible contribution from line tension at these smaller dimensions. © The Royal Society of Chemistry.

Numerical analysis of shallow foundations under combined horizontal and torsional loading

Foundations of subsea infrastructure in deep water subjected to asymmetric environmental loads have underscored the importance of combined torsional and horizontal loading effects on the bearing capacity of rectangular shallow foundations. The purpose of this study is to investigate the undrained sliding and torsional bearing capacity of rectangular and square shallow foundations together with the interaction response under combined loading using three-dimensional finite element (3D-FE) analysis. Upper bound plastic limit analysis is employed to establish a reference value for horizontal and torsional bearing capacity, and an interaction relationship for the combined loading condition. Satisfactory agreement of plastic limit analysis (PLA) and 3D-FE results for ultimate capacity and interaction curves ensures that simple PLA solution could be used to evaluate the bearing capacity problem of foundation under combined sliding and torsion.