bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Engineered Porous Silicon-based Nanostructures for Cancer Therapy
Authors: Tzur-Balter Adi , Massad-Ivanir Naama , Segal Ester
Published: November 2012

In this work, nanostructured porous silicon (PSi) hosts, synthesized by electrochemical etching of Si, are designed to carry and release the anti cancer drug, mitoxantrone dihydrochloride (MTX). We study the effect of surface chemistry of the Si scaffold on its properties as a drug carrier. The freshly-etched PSi is modified by surface alkylation using thermal hydrosilylation with 1-dodecene. Fourier-transform infrared spectroscopy and nitrogen adsorption-desorption measurements are employed to characterize the PSi carriers after chemical modification. Both, drug loading efficiency and release kinetics are found to be significantly affected by surface chemistry of the PSi.In vitrocytotoxicity studies on human breast carcinoma (MDA-MB-231) cells show that the MTX released from the PSi hosts maintains its cytotoxic functionality.
Young’s Modulus of Cortical and P19 Derived Neurons Measured by Atomic Force Microscopy
Authors: Spedden Elise , White James D. , Kaplan David , Staii Cristian
Published: November 2012

In this paper we use the Atomic Force Microscope to measure the Young’s modulus for two types of neuronal cell bodies: cortical neurons obtained from rat embryos and neurons derived from P19 mouse embryonic carcinoma stem cells. The neurons are plated on different substrates coated with two types of protein growth factors, poly-D-lysine and laminin. We report on the Young’s modulus of each type of neuron as well as the variation of modulus between cells plated on different protein substrates. We compare these results to various individual cell and bulk tissue measurements reported in literature. We additionally report on an observed change in the Young’s modulus of cortical neurons when subjected to a short-term reduction in ambient temperature.
The variation in elastic properties of limpet teeth
Authors: Lu Dun , Hang Fei , Barber Asa H.
Published: November 2012

Limpet teeth are an example of a biological short fiber reinforced composite material used for a mechanical function. The local micro-scale elastic properties of limpet teeth were examined by bending FIB fabricated beams of the limpet tooth material using atomic force microscopy (AFM). The elastic modulus values for the limpet tooth material varied from 140 GPa at the tooth posterior edge, through 90 GPa at the tooth core to 120 GPa at the tooth anterior edge. This variation in the elastic modulus of limpet tooth material at the posterior, interior and core regions of the tooth is indicative of a mechanically graded structure and is expected to enhance the durability of limpet teeth during rasping over rock surfaces during feeding.
Hierarchical Structure of Porosity in Cortical and Trabecular Bones
Authors: Novitskaya Ekaterina , Hamed Elham , Li Jun , Manilay Zherrina , Jasiuk Iwona , McKittrick Joanna
Published: November 2012

In this paper the amount and morphology of cortical and trabecular bone porosities were estimated using optical microscopy and micro-computed tomography technique. The hierarchical structure of porosity at different structural scales spanning from a single lacuna (sub-microscale) to trabecular or cortical bone levels (mesoscale) was characterized and described. This study was conducted by using samples of untreated, deproteinized and demineralized bones, to obtain better insight into the bone structure and porosities. The motivation of this work is that the porosity in bone has a major effect on its mechanical response, yet it is often neglected in bone models. Investigations of the mechanical properties of bone and its main components (collagen and mineral phases), complemented by modeling, are of importance in orthopedics.
Hydrophobicity of Teflon Coated Well-Ordered Silver Nanorod Arrays
Authors: Alagoz Arif S. , Khudhayer Wisam J. , Karabacak Tansel
Published: November 2012

From wings of flies to plant leafs, hydrophobic surfaces are well-common in nature. Many of these surfaces have micro and nano hierarchical structures coated with low surface energy layer. In this work, we mimicked similar structure by fabricating Teflon coated periodic and well-ordered silver nanorod arrays and investigated the effect of nanorod separation on water contact angle (WCA). The silver nanorod arrays were deposited on patterned and flat silicon substrates using glancing angle deposition (GLAD) technique. Then a thin layer of Teflon was deposited on the silver nanorods by small angle deposition (SAD) technique. A systematic increase in water contact angle was observed with increasing nanorod separation which is attributed to the decreased area fraction of solid-liquid interface.
Formation and Applications of Hierarchically Porous Carbon, Metals and Metal Oxides Formed by Nanocasting
Authors: Sayler Franchessa M. , Grano Amy J. , Scogin William , Sanders Pasha , Smått Jan-Henrik , Shaughnessy Kevin H. , Bakker Martin G.
Published: November 2012

Hierarchically porous materials are of interest in a wide range of applications. If the materials are electronic or ionic conductors such materials are of interest as electrodes for use in fuel cells, flow batteries, electrocatalysis, and pseudo/supercapacitors. We have demonstrated the synthesis of hierarchically porous carbon, metal and metal oxide monoliths. Hierarchically porous silica with porosity at three length scales: 0.5-30 micrometer, 200-500 nm, and 3-8 nm, is used as a template to form these materials. The porosity of the silica template is produced by spinodal decomposition (0.5-30 micrometer), particle agglomeration (200-500 nm) and addition of surfactant or block copolymer (3-8 nm). Nanocasting: replication of all or part of the structure via one of a number of chemical replication techniques has been used to produce the carbon, metal oxide and metal replicas. The final surface areas of the materials can be as high as 1200 m2/g for carbon replicas, and >300 m2/g for metals and metal oxides. The use of the nanocasting technique allows for formation of materials that are compositionally or spatially heterogeneous.

We report here results on the synthesis and characterization of hierarchically porous monoliths of carbon and, nickel and the use of some of these monoliths in catalysis and electrochemical capacitors.
Light Splitting Function of Branched Chains of Microspheres Fabricated by Self-Assembly Process
Authors: Mitsui Tadashi , Wakayama Yutaka , Onodera Tsunenobu , Hayashi Takeru , Ikeda Naoki , Sugimoto Yoshimasa , Takamasu Tadashi , Oikawa Hidetoshi
Published: November 2012

Using a self-assembly process, we fabricated ordered chains of transparent polystyrene microspheres that have 30°- and 60°-branched structures and that act as coupled-resonator optical waveguides (CROWs). We then observed the optical properties of propagation light through the CROWs. The light spectra were directly measured by guide-collection-mode near-field scanning optical microscopy (NSOM) techniques. The spectrum of light propagating to the 60°-branch shows some sharp peaks, which seem to be associated with whispering gallery modes (WGMs). On the other hand, the spectrum of light propagating to the 30°-branch shows rather broad peaks. Moreover, we observed the detailed structures of the CROWs by high-resolution scanning electron microscopy (HR-SEM), and performed a finite-difference time-domain (FDTD) simulation to explain the NSOM spectra. The results suggest that the microspheres’ branching chains themselves have a light-splitting function, which is a kind of wavelength-selective filter.
Strong Multimode Photonic Microresonator and Nanoparticle Interactions
Authors: Ostrowski M. , Pignalosa P. , Yi Y.
Published: November 2012

We have demonstrated strong multimode photonic microresonator and nanoparticle interactions by using an integrated micro disk resonator from through port of the laser coupling bus waveguide. In addition to the fundamental resonance mode, disk resonator has higher order resonance modes. The excited higher order mode has a node at the position where the electromagnetic energy of the fundamental mode is close to a maximum. Here we report that a self referencing mechanism can be achieved by simultaneous excitation of both fundamental and 2nd order micro disk optical resonance modes. Additionally, we are able to measure the area around the maximum of the fundamental resonance mode and the node of the higher order mode, which have overlaps in the disk. In this work, we used on chip disk microresonator as the example, as a variety of types of optical microresonators have been investigated; we used nanoparticle to interact with the two optical resonance modes excited by the coupling bus waveguide, where the nanoparticle can be either dielectric materials or metallic materials. The strong photonic microresonator and nanoparticle interactions have variety of applications for optical switches, waveguides and detection. The self-referencing characteristics of the two optical resonance modes have potential to achieve photonic functions independent of external perturbation, such as temperature change.
Application of 3-D Hierarchically Porous Silver, Cobalt Oxide and Zinc Oxide Monoliths to Chromatographic Separations
Authors: Sayler Franchessa M. , Grano Amy , Wiedmer Susan , Smått Jan-Henrik , Bakker Martin G.
Published: November 2012

Hierarchically porous silica monoliths were introduced into liquid phase chromatography at the beginning of the last decade. The high surface area, high void volume and bicontinuous nature of the porosity of the materials are significant advantages over existing chromatographic supports and have resulted in rapid acceptance of these materials into the chromatography market.

We report here on the synthesis of 3-D porous silver, cobalt oxide and zinc oxide monoliths, their materials characterization, fabrication as liquid chromatographic columns and initial chromatographic characterization. The, as prepared, columns gave very low back pressure, consistent with the bicontinuous nature of the columns. Cobalt oxide and zinc oxide both demonstrated retention of a number of nitrogen heterocycles, providing the basis for molecular separation.
Low-temperature Phosphorus Doping To Silicon Using Phosphorus-related Radicals
Authors: Hayakawa Taro , Nakashima Yuuki , Koyama Koichi , Ohdaira Keisuke , Matsumura Hideki
Published: November 2012

Phosphorus (P) doped ultra thin n+-layer is formed on crystalline silicon (c-Si) at low substrate temperatures of 80 – 350 °C using radicals generated by the catalytic reaction of phosphine (PH3) with a tungsten catalyzer heated at 1300 °C. The sheet carrier concentration obtained by Hall effect is in the range between 3×1012cm-2 and 8×1012cm-2. The distribution of P atoms obtained by secondary ion mass spectrometry (SIMS) indicates that P atoms locate within the depth of 4 nm from surface and the profile has almost the same distribution independent of any doping conditions such as substrate temperature or radical exposure time. The sheet carrier concentration is 1.15 – 2.12% of the amount of P atoms incorporated through the radical doping. The ratio of activated donors increases with substrate temperature during the radical doping, suggesting that P-related species bonded on the c-Si surface require thermal energy for their activation. Using the n+-layer formed by radical doping, the reduction of surface recombination velocity for n-type c-Si wafer is attempted. The effective minority carrier lifetime of the n-type c-Si sample covered with 6-nm-thick intrinsic amorphous Si (i-a-Si) layers on both side increases from 32 μs to1576 μs by the radical doping of P atoms to n-type c-Si surface, suggesting that the radical doping can be utilized for the formation of passivation layers on a-Si/ n-c-Si hetero-interface.
Fabrication of Organic Polymer Solar Cells by a Novel Solution-Based Vapor-like Mist Deposition Method
Authors: Ikenoue Takumi , Fujita Shizuo
Published: November 2012

Organic solar cells with PEDOT:PSS hole transport layer or P3HT:PCBM active layer deposited by a novel solution-based mist deposition technique were fabricated and demonstrated. The device with mist-deposited PEDOT:PSS layer showed higher short circuit current density and power conversion efficiency than those of the one with spin-coated PEDOT:PSS layers. The device with mist-deposited P3HT:PCBM layer also performed with higher power conversion efficiency. The results encourage the promising potential of the mist deposition method for device fabrication.
Doping Effect on Chloroindium Phthalocyanine (ClInPc)/C60 Solar Cells
Authors: Wang Weining , Armstrong Neal
Published: November 2012

For inorganic semiconductor solar cells, controlled doping is important because it can cause Fermi level shift of the inorganic semiconductor and achieve ohmic contact at the metal-semiconductor interface. In this paper we show that doping can also be used to shift Fermi level in organic semiconductors and cause changes in solar cell performance. We have made chloroindium phthalocyanine (ClInPc)/C60 heterojunction solar cells, where tetrafluoro-teracyano-quinodimethane (F4-TCNQ) is used to dope ClInPc layer. Ultraviolet photoemission spectroscopy (UPS) is used to investigate the ITO/ClInPc interfaces. The result shows that doping causes a Fermi level shift at the ITO/ClInPc interface as it does for inorganic semiconductors. As the doping increases, dark saturation current J0 of the solar cell increases, while open-circuit voltage Voc, short-circuit current Jsc and fill factor decreases. As a result, the efficiency of the solar cell decreases as doping increases. More UPS studies on ClInPc (doped with F4TCNQ)/C60 junction are needed to correlate the energy band diagram of the whole solar cell structure with the J-V characteristics.
Electrochemical studies and Thermodynamic Parameters of tris(2,2’-bipyridyl) ruthenium (II) in nonaqueous Solutions
Authors: Bolormaa Gendensuren , Battulga Munkhbat , Naranbileg Batjargal , Battsengel Baatar , Ganzorig Chimed
Published: November 2012

In this study Ruthenium (II) tris (2, 2’-bipyridyl) complex in nonaqueous solution was studied by cyclic voltammetry and also its kinetic parameters were calculated. The redox reaction of ruthenium (II) trisbipyridyl complex is totally quasi-reversible and it can be described as a diffusion-controlled process. As a result of the redox reaction, the kinetic parameters of the electrode process such as diffusion coefficient (D), and heterogeneous rate constant (ks) were calculated. In addition, the different thermodynamic parameters such as standard free energy (ΔG#), enthalpy change (∆H#), and entropy change (∆S#) were determined and enthalpy change revealed the exothermic behavior of the electrode reaction. Both oxidation and reduction onset potentials of the ruthenium (II) trisbipyridyl complex was determined under the same experimental conditions to estimate the low ionization potential and electron affinity. The electrochemical and optical band gaps of the ruthenium (II) complex were compared.
Radioactive Waste and Spent Fuel Management in Argentina
Authors: Maset Elvira Rosa
Published: November 2012

Since its creation in 1950, the Argentine Atomic Energy Commission (CNEA), has worked on the development of applications for the peaceful use of nuclear energy. They include, among others, research and development activities in basic and nuclear technology areas, the operation of important facilities for the production of radioisotopes and the performance of tasks in connection with the nuclear fuel cycle, mining and uranium processing activities, manufacturing of fuel elements, production of heavy water and the operation of two nuclear power plants. Also demonstrating reprocessing programs have been developed.

As a result of the above mentioned activities performed in the nuclear field by private and public entities, various types of radioactive waste have been and are produced during operation and maintenance of facilities and plants, and will be produced in their future decommissioning. CNEA is also responsible for the environmental remediation of the closed uranium mining and milling facilities and for the management of disused sealed sources from medical and industrial applications.

Activities concerning radioactive waste management are carried on according not only to Nuclear Regulatory Authority requirements and International Atomic Energy Agency recommendations, but also to the national legal framework.

The Law Nº 25.018, "Radioactive Waste Management Regime“(1998), created the National Program for Radioactive Waste Management (PNGRR), as part of CNEA organization.
The Role of Performance Assessment through the Multiple Phases of a Nuclear Waste Management Program
Authors: Bonano E.J. , Freeze G.A. , Appel G.
Published: November 2012

In many countries, regulations for the management of nuclear waste require a performance (safety/risk) assessment to demonstrate the safety asserted to be provided by the sites/facilities proposed for handling, storing, and disposing of the wastes. However performance assessment can play a bigger role than solely demonstration of compliance with applicable safety standards in support of a regulatory decision (i.e., licensing of a waste management facility). Performance assessment can be an effective management tool during all phases of a waste management program: from development of national nuclear waste management policies; to programmatic environmental impact assessments associated with design and siting evaluations, site selection, and site characterization; to licensing and operation of facilities.

International experience has demonstrated that nuclear waste management programs are long-term efforts, lasting at least two to three decades from initial policy development to licensing and commencement of waste management and disposal operations. This experience has also demonstrated that consistent attention to, and integration of, initial component studies are necessary to provide a comprehensive total system analysis for programmatic environmental impact assessments and for licensing.

For nearly 40 years, Sandia National Laboratories has developed and applied a performance assessment methodology in numerous national and international nuclear waste management programs. These applications range from development and feasibility testing of environmental health standards to preliminary evaluation of waste disposal sites; to establishing the basis for demonstration of compliance; to informing licensing (compliance demonstration) decisions. In many of these applications the performance assessment methodology has also served as a management tool for confirming the added value of research and development investments.

This paper presents examples to illustrate how performance assessment has been used as an effective management tool through multiple phases of a nuclear waste management program.
Main results of the French program on Partitioning and Transmutation of Minor Actinides
Authors: Poinssot Ch. , Boullis B , Rostaing C. , Warin D.
Published: November 2012

In the framework of the successive 1991 and 2006 Waste Management Act, French government supported a very significant R&D program on partitioning and transmutation of minor actinides (MA). This program aims to study potential solutions for still minimizing the quantity and the hazardousness of final waste, by MA recycling. Indeed, MA recycling can reduce the heat load and the half-life of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste.

Within this framework, this paper aims to present the most recent progress obtained in CEA on the development of innovative actinide partitioning hydrometallurgical processes in support of their recycling, either in an homogeneous mode (MA are recycled at low concentration in all the standard reactor fuel) or in an heterogeneous mode (MA are recycled at higher concentration in specific targets, at the periphery of the reactor core). Recovery performances obtained on recent tests in high active conditions of the so-called GANEX and DIAMEX-SANEX process will be presented and discussed in light of the potential P&T scenarios. Finally, recent developments regarding the recycling of the sole Am will be presented as well as the results obtained on highly active solutions for this so-called EXAM process.

This set of results gives to the French government a portfolio of potential recycling processes which could be separately and progressively implemented if decided.
Assessing the role of spent fuel surfaces during leaching in presence of hydrogen by using Cr(VI) as a redox marker
Authors: Puranen A. , Ekeroth E. , Granfors M. , Low J. , Spahiu K.
Published: November 2012

In many deep repository concepts spent nuclear fuel (SNF) will be disposed in canisters containing large amounts of iron. Intrusion of groundwater in a failed canister may occur under the presence of hydrogen, expected to be produced by the anoxic corrosion of iron. Compelling evidence now exists that hydrogen inhibits oxidative dissolution of SNF, the mechanism is however not fully understood. Hydrogen generally requires a catalyst in order to operate as a reductant. The metallic inclusions (ε-particles) present in SNF are a likely catalyst for this process due to their noble metal content. There is also evidence that the SNF UO2 matrix or doping of the UO2 with fission products can activate hydrogen. In most spent fuel experiments carried out under hydrogen, a decrease in concentration of all redox sensitive nuclides originating from a pre-oxidized layer is observed. Given their low concentrations and abundance in the fuel, it has however been difficult to detect any reductive precipitation on the fuel surfaces.

In this study, Cr(VI) oxyanions were employed as a redox sensitive marker, as Cr(VI) is expected to precipitate as Cr(III) oxide on the catalyst that activates hydrogen.

In the experiments PWR spent fuel (43 MWd/kgU) was leached in simulated groundwater (10 mM NaCl, 2 mM NaHCO3) at 25 and 70 ◦C under 5 MPa of hydrogen and dissolved Cr(VI). Dark green, Cr(III)-oxide was found to precipitate; mapping by electron microscopy (SEM-WDS) evidenced a Cr rich layer covering the fuel, suggesting that the whole fuel surface is catalyzing the reduction of chromium.
Development of Surface Marker System for the Observation of Microstructural Changes in Nuclear Graphite using Micro X-ray Tomography
Authors: Holmes Rosemary A. , Jones Abbie N. , McDermott Lorraine , Marsden Barry
Published: November 2012

Current energy demands and future energy needs are a growing industry which at present attracts a large amount of research and investment of which nuclear energy is an integral part. Eight new nuclear stations are proposed to be developed in the UK over the next ten years to meet this demand. In order for nuclear energy to sustain growth and development, nuclear decommissioning of first and second generation power stations needs to be addressed in the U.K. and worldwide. Presently the UK has 36 graphite moderated reactors as a result of the UK military and civil programs, which over the next twenty years will close. This will result in ∼99’000 tonnes of irradiated graphite waste for which no current national decommissioning strategy exists. The main issues associated with this waste are the large volume and activation products associated. By far the greatest inventory is from 3H and 14C. An EU Euroatom FP7 Program; CARBOWASTE was established in 2008 with the aim of developing treatment and disposal options for graphite.

This research is based within CARBOWASTE, the main objectives are to understand the mechanisms involved in the production, location and removal of radioisotopes from nuclear graphite. Computed X-ray Tomography (CT) will be used in order to quantify the initial porosity in conjunction with thermal treatment (ex situ) in order to eventually identify the location of 14C within the matrix of irradiated graphite, through the preferential chemically controlled oxidation of graphite. Unirradiated Pile Grade A graphite samples have been laser and manually marked in order align the samples prior to and post thermal treatment to determine the degree of porosity changes and weight loss under a range of thermal oxidation parameters.
Modeling the Production of Tritium, Carbon-14 and Cobalt-60 in Irradiated Graphite from a UK Magnox Reactor
Authors: Black Greg , Jones A. N. , McDermott Lorraine , Marsden B. J.
Published: November 2012

The Tritium, Carbon-14 and Cobalt-60 content of a trepanned sample from one of the Wylfa Magnox reactor have been experimentally determined using beta liquid scintillation counting and gamma spectroscopy. The WIMS9a reactor code and FISPACT-2007 neutron activation software have also been used to calculate this inventory for the sample, considering only a model which is isolated from the reactor circuit. Comparison between experimental and calculated results has shown that the calculated values for 14C are within 26%, 60Co within 24% and 3H 120%. These results show that the original impurity levels are sufficient to explain the experimentally determined end of life activity, without additional consideration of contamination from other materials in the reactor circuit, in this type of simulation. Additionally the calculations show that the production of 14C from 14N is approximately equal to that produced from 13C. These results are only applicable to the isolated system models developed here, and do not explicitly model existing reactor conditions, where external operating conditions may interact with the graphite and the core environment
Instant Release Fractions from Corrosion Studies with High Burnup LWR Fuel.
Authors: Ekeroth Ella , Cui Daqing , Low Jeanett , Granfors Michael , Zwicky Hans-Urs , Spahiu Kastriot , Zetterström Evins Lena
Published: November 2012

During irradiation in the reactor, a fraction of the fission product inventory will have segregated either to the gap between the fuel and the cladding or to the grain boundaries in the fuel. Of these nuclides, the behavior of the fission gases is best known. The part of the inventory that is rapidly released upon contact with water is designated the instant release fraction (IRF). Previous studies have shown that IRF and fission gas release (FGR) seem to be correlated. Studies of the instant release fraction from high burnup fuel is of interest for the assessment of the safety of a geological repository.

The instant release fractions of129I and137Cs from five different light water reactor (LWR) fuel rods with a burnup range of 43 to 75 MWd/kgU and a fission gas release range from 0.9 to 5.0 % were studied. Four types of fuel samples (pellet, fragment, powder and fuel rodlet) have been used in the experiments. The results show that the fuel sample preparation method has a significant impact on the release from high burnup fuel samples over the time period covered by this study. Leaching of high burnup fuel samples with fuel detached from the cladding shows the highest release. The fractional129I release from such fragment samples is similar to the FGR in the corresponding rod. On the other hand, corresponding fractional release of137Cs is lower.
Spent fuel dissolution in Belgian Supercontainer conditions: source term and compatibility
Authors: Lemmens K. , Mennecart Th. , Cachoir C.
Published: November 2012

In the frame of the Safety and Feasibility Case 1 development, the Belgian agency for radioactive waste (ONDRAF/NIRAS) has to demonstrate that the geological disposal of spent nuclear fuel in the Boom Clay host rock following the Supercontainer design provides sufficient radiological safety in the long term. This safety relies on the containment of the radionuclides by the overpack, the limitation of radionuclide release from the waste matrix, the diffusion controlled transport of the radionuclides, and their low solubility and sorption on the Boom Clay host rock. This paper presents an evaluation of the main processes considered for the limitation of radionuclide release by the Spent Fuel in Supercontainer conditions, characterized by the presence of a concrete buffer and hyperalkaline pore water. We present a description of the main expected processes with their potential impact on the fuel alteration mechanisms, and potential reference fuel matrix alteration rates and effective fuel surface areas for use in safety and performance assessment models.
Very Long-Term Dry Storage Systems for Spent Nuclear Fuel: Effect of Canister Weld Corrosion on System Integrity
Authors: Di Bella Carlos A. W. , Duquette David J. , Rigby Douglas B.
Published: November 2012

Termination of the Yucca Mountain repository program implies that U.S. spent nuclear fuel (SNF) and high-level radioactive waste may be stored for very long periods, i.e., more than 100 years. Many of the storage systems for commercial SNF are large, cylindrical, welded, stainless-steel canisters containing 24-80 SNF assemblies in an inert gas (helium) environment. Each canister is contained in a massive reinforced concrete structure for shielding, safety, and security reasons. Airflow in the annular space between the canister and the concrete structure removes SNF decay heat by natural convection.

Undetected defects in the canister-lid welds and stress corrosion cracking (SCC) in the canister-lid weld area may combine to form pathways for slow escape of the inert fill gas from the canister. SCC may not occur until many decades after SNF is loaded into the canister because SNF decay heat initially would keep the canister surface temperatures above the temperature where liquid water, a prerequisite for SCC, could condense. The period required for inert gas to escape from the canister once pathways have formed and for air subsequently to enter the canister may also be measured in decades, depending on the size and shape of the pathways.

In this paper, the authors explore the limits of weld-flaw detectability; when necessary conditions for SCC could occur in the canister-lid weld area; the period for loss of inert fill gas if through-weld cracks occur; and the possible consequences of fill gas loss. The authors also develop a list of research and study needs to address the possibility of SCC resulting in the loss of fill gas.
The making of a Yugoslav popular music industry
Authors: Vuletic Dean
Published: November 2012

In the late 1950s and early 1960s, Yugoslavia’s popular music industry experienced rapid growth as a result of the cultural and economic policies of the League of Communists of Yugoslavia (LCY), which ruled the state from 1945 to 1990. These policies provided for investments in the expansion of the popular music industry through festivals, record companies and radio and television services, with the models for these usually being taken from the West. The LCY considered the development of the popular music industry to be important as an expression of the cultural openness that marked its nonaligned foreign policy, a symbol of the party’s achievements in economic growth and modernization, and a factor that would contribute to the construction of cultural bonds among Yugoslavia’s multinational citizenry.
From dance bands to radio and records
Authors: Nathaus Klaus
Published: November 2012

This article traces key developments in the production and promotion of popular music in West Germany during the twenty years after the Second World War. Starting from the observation that performance royalties were a relatively important source of revenue from music, the article first describes how, around 1950, dance bands became the principal gatekeepers, before looking at the impact of radio and records on the musical production system. It shows that this structural change led to a marked concentration of the music business and argues that the immediate effect on the popular repertoire was moderate. The most consequential change was a widespread condemnation of Schlager and a growing sense of detachment from this genre among songwriters, which set the path for the further decline of this musical style in subsequent decades.
Adopting the rights-based model
Authors: Bakker Gerben
Published: November 2012

This article identifies four economic tendencies that shaped the development of the international recorded music industry since 1945: the importance of endogenous sunk costs led to a quality race; the fact that marginal revenue equalled marginal profit led to extreme vertical integration; the quasi-public good character of music its non-diminishability but partial excludability led to a sharply unequal income distribution among stars and the pioneering of new business models to transform consumer into producer surplus; and finally, the project based character of music production led to decentralized agglomeration. What can be characterized as rights-based multinationals emerged as a response to these forces. They married extreme vertical integration and a portfolio of A&R labels having limited economies of scale and scope, with a global distribution and marketing machine. This article tries to explain how they emerged and how they can explain increasing industrial concentration in the face of sharp growth of the market and of musical diversity.
Trocas gasosas e balanço de carboidratos em plantas de cana-de-açúcar sob condições de estresses radiculares
Authors: Sales Cristina Rodrigues Gabriel , Ribeiro Rafael Vasconcelos , Machado Daniela Favero São Pedro , Machado Ricardo Silverio , Dovis Verónica Lorena , Lagôa Ana Maria Magalhães Andrade
Published: November 2012

Embora a resposta da fotossíntese de plantas de cana-de-açúcar a estresses ambientais seja conhecida, o acúmulo de fitomassa e a dinâmica de carboidratos de reserva diante da exposição simultânea ao frio e à seca são pouco conhecidos. Este trabalho objetiva investigar o efeito do déficit hídrico e da baixa temperatura radicular, isolados e simultaneamente, no genótipo de cana-de-açúcar IACSP94-2094, considerado tolerante à seca. Como hipótese, consideramos que este genótipo também é tolerante à baixa temperatura radicular, já que baixas temperaturas e déficit hídrico ocorrem simultaneamente no campo. A imposição da restrição hídrica de forma isolada ou simultaneamente à baixa temperatura radicular causou redução do potencial da água na folha e da assimilação de CO2, o que não foi observado nas plantas submetidas apenas à baixa temperatura do substrato. Os teores foliares de carboidratos não estruturais, de sacarose e de amido aumentaram nas plantas sob frio radicular. Nos tratamentos com déficit hídrico, apenas o teor de amido foliar diminuiu. Os estresses radiculares causaram aumento nos teores de açúcares solúveis totais e diminuição no teor de amido nas raízes. Como o acúmulo de fitomassa das plantas não foi afetado, mesmo com a restrição no crescimento radicular nos tratamentos com baixa temperatura do substrato, conclui-se que o genótipo de cana-de-açúcar IACSP94-2094 contém indícios de tolerância à baixa temperatura radicular. A manutenção do crescimento da planta deve estar associada à degradação das reservas de amido foliares e radiculares.
Caracterização de novos isolados de Bacillus thuringiensis para o controle de importantes insetos-praga da agricultura
Authors: Campanini Emeline Boni , Davolos Camila Chiaradia , Alves Eliane Cristina da Cunha , Lemos Manoel Victor Franco
Published: November 2012

A bactéria Bacillus thuringiensis Berliner produz um corpo de inclusão paraesporal (cristal) de natureza proteica, formado durante a esporulação, que atua de forma eficiente no controle de insetos-praga de culturas economicamente importantes. Esse cristal é constituído de proteínas Cry, que são codificadas pelos genes cry; um isolado pode ser caracterizado pelo conteúdo de genes cry que apresenta. Visando caracterizar novos isolados no combate de insetos-praga pertencentes às ordens Lepidoptera e Coleoptera, 76 isolados bacterianos foram analisados molecularmente e tiveram seu potencial de controle avaliado por meio de bioensaios com larvas de Spodoptera frugiperda (J.E. Smith), Sphenophorus levis Vaurie e Tenebrio molitor Linnaeus. As análises moleculares indicaram 11 isolados (14,5% da coleção), contendo genes lepidóptero-específicos e 17 (22,37%) com genes coleóptero-específicos. As análises de patogenicidade revelaram dois isolados com alto potencial de controle para lagartas de S. frugiperda, um para larvas de S. levis e seis prejudiciais ao desenvolvimento das larvas de T. molitor. Esses isolados de B. thuringiensis podem ser promissores no controle biológico das referidas pragas.
Shelf life of minimally processed pineapples treated with ascorbic and citric acids
Authors: Antoniolli Lucimara Rogéria , Benedetti Benedito Carlos , Souza Filho Men de Sá Moreira de , Garruti Deborah dos Santos , Borges Maria de Fátima
Published: November 2012

The purpose of this research was to determine the shelf life of minimally processed (MP) 'Pérola' pineapples treated with ascorbic acid (AA) and citric acid (CA) based on physical, chemical, sensorial and microbiological attributes. Slices were dipped into drinking water (control) or combined solutions of AA:CA (%) (1.0:0.5 and 1.0:1.0) with sodium hypochlorite (NaClO 20 mg L-1) for 30 seconds. The samples were conditioned in polyethylene terephtalate packages and stored at 4±1 °C per 13 days. The low peroxidase activity in the slices treated with antioxidant combinations was related to low pH values observed in these samples. The treatments 1.0:0.5 and 1.0:1.0 (AA:CA, %) favored maintenance of the initial a* values and avoided the pulp browning. The ascorbic acid increased more than double on the 2nd day in the treated slices. By the 4th day the CO2 values suggested a higher respiratory activity in the slices treated with anti-browning compounds. The antioxidant treatments did not produce detectable residual flavors in the MP pineapple. Regardless of microbiological safety during the 13 days of cold storage, the control slices can be kept by 6 days, afterwards the color and dehydration become strong enough to affect the appearance. On the other hand, MP 'Pérola' pineapples treated with 1.0:0.5 (AA:CA, %) and NaClO (20 mg L-1) can be stored for 8 days at 4±1 ºC, which represents the extension of the shelf life in 2 days. After this period the overripe odor starts to develop.
Evapotranspiração e estimativa da água consumida em perímetro irrigado do Semiárido brasileiro por sensoriamento remoto
Authors: Silva Bernardo Barbosa da , Braga Alexandra Chaves , Braga Célia Campos , Oliveira Leidjane Maria Maciel de , Galvíncio Josiclêda Domiciano , Montenegro Suzana Maria Gico Lima
Published: November 2012

O objetivo deste trabalho foi mapear a evapotranspiração real (ETr) e determinar o volume de água utilizado no projeto de irrigação de São Gonçalo, PB, no Semiárido brasileiro, com auxílio do sensoriamento remoto. Foram adquiridas imagens TM/Landsat 5 da área em estudo, em 2008, que foram utilizadas na obtenção dos mapas temáticos da ETr diária. Selecionaram-se dois pomares de coqueiro‑anão para validação dos resultados da evapotranspiração obtida com o "surface energy balance algorithm for land" (ET Sebal) e com o método FAO‑56 (ET FAO). Para determinação da ET FAO, utilizou-se o produto entre o coeficiente de cultura, o coeficiente de ajuste e a evapotranspiração de referência. As diferenças obtidas, com uso das duas técnicas, resultaram em raiz do erro quadrado médio, erro relativo médio e erro absoluto médio iguais a 0,53 mm, 9,46% e 0,43 mm, respectivamente. Nas áreas irrigadas, a ETr representou 85% do saldo de radiação e, nas de sequeiro, apenas 12,5%. O mapeamento da ETr delimitou claramente as áreas irrigadas das de sequeiro, bem como as diferenças existentes no interior do perímetro irrigado do projeto em investigação. O volume de água empregado no projeto de irrigação representa, somente no período de julho a dezembro, mais de 60% da capacidade do açude de São Gonçalo.
Técnicas de geoinformação para estimativa do balanço hídrico em eucalipto
Authors: Facco Alexandro Gomes , Ribeiro Aristides , Pruski Fernando Falco , Monteiro Welliam Chaves , Leite Fernando Palha , Andrade Ricardo Guimarães , Menezes Sady Júnior Martins da Costa de
Published: November 2012

O objetivo deste trabalho foi avaliar a influência da topografia no balanço de radiação e na disponibilidade hídrica em microbacia hidrográfica com plantio de eucalipto, bem como verificar os efeitos dos plantios de eucalipto na regularização do escoamento da água. Foram monitorados os componentes do balanço hídrico em uma microbacia hidrográfica localizada na região Leste do Estado de Minas Gerais. Os componentes do balanço hídrico foram computados pontual e espacialmente, em escala horária, para a camada útil do solo. Os resultados foram comparados com os valores medidos a partir da lâmina escoada pelo curso d'água. Nos meses em que houve disponibilidade de água no solo, os valores médios da transpiração real, estimada a partir do método espacial, foram maiores que os estimados pelo método pontual. A estimativa do balanço hídrico é mais eficiente quando considera os efeitos do relevo. As florestas de eucalipto regulam o escoamento de água em microbacias hidrográficas.
Cropland area estimates using Modis NDVI time series in the state of Mato Grosso, Brazil
Authors: Victoria Daniel de Castro , Paz Adriano Rolim da , Coutinho Alexandre Camargo , Kastens Jude , Brown J. Christopher
Published: November 2012

The objective of this work was to evaluate a simple, semi‑automated methodology for mapping cropland areas in the state of Mato Grosso, Brazil. A Fourier transform was applied over a time series of vegetation index products from the moderate resolution imaging spectroradiometer (Modis) sensor. This procedure allows for the evaluation of the amplitude of the periodic changes in vegetation response through time and the identification of areas with strong seasonal variation related to crop production. Annual cropland masks from 2006 to 2009 were generated and municipal cropland areas were estimated through remote sensing. We observed good agreement with official statistics on planted area, especially for municipalities with more than 10% of cropland cover (R² = 0.89), but poor agreement in municipalities with less than 5% crop cover (R² = 0.41). The assessed methodology can be used for annual cropland mapping over large production areas in Brazil.
Imagens multipolarizadas do sensor Palsar/Alos na discriminação das fases fenológicas da cana‑de‑açúcar
Authors: Picoli Michelle Cristina Araujo , Lamparelli Rubens Augusto , Sano Edson Eyji , Rocha Jansle Vieira
Published: November 2012

O objetivo deste trabalho foi avaliar o potencial das imagens multipolarizadas do sensor‑radar Palsar/Alos em diferenciar as fases fenológicas da cana‑de‑açúcar. Valores digitais de quatro imagens do sensor, dos meses de fevereiro, maio, agosto e outubro de 2008, com polarizações HH (emissão e recebimento de onda na polarização horizontal) e HV (emissão de onda na polarização horizontal e recebimento na vertical), foram convertidos para coeficientes de retroespalhamento (σ°), para a análise de dados de cana‑de‑açúcar, cultivadas em talhões na região nordeste do Estado de São Paulo. Foram selecionadas três variedades, em diferentes estágios fenológicos: RB85‑5156, seis talhões; RB86‑7515, dez talhões; e RB92‑5345, dez talhões. As diferenças entre as fases fenológicas foram avaliadas para cada uma das variedades e, também, entre as variedades. A utilização simultânea ou não dos dados do sensor Palsar/Alos, obtidos em duas polarizações, foi capaz de discriminar as diferentes fases de crescimento da cana‑de‑açúcar, com exceção da fase de crescimento dos colmos e a fase de maturação, em que não foi observada diferença significativa.
Obstrução do horizonte calculada a partir de modelo digital de elevação
Authors: Weber Eliseu José , Fontana Denise Cibys
Published: November 2012

O objetivo deste trabalho foi avaliar a exatidão do cálculo da obstrução do horizonte, a partir de um modelo digital de elevação (MDE), em diferentes situações topográficas. O material utilizado incluiu um MDE disponível para a região da Serra Gaúcha, RS, receptores GPS, câmera digital, lente grande‑angular e os programas Idrisi, Arcview/ArcGIS e Solar Analyst. Foram adquiridas fotografias hemisféricas, e coletadas as coordenadas de 16 locais na área de estudo. As coordenadas e o MDE foram utilizados para calcular a obstrução do horizonte com uso do algoritmo Solar Analyst. Foram comparadas a fração aberta do céu calculada e a obtida pelas fotografias hemisféricas. O coeficiente de determinação foi de 0,8428, tendo-se observado superestimativa média de 5,53% da fração aberta do céu. Os erros são atribuídos principalmente à obstrução pela vegetação, que não pode ser identificada pelo MDE. A obstrução do horizonte, causada pelo relevo na Serra Gaúcha, pode ser calculada satisfatoriamente pelo Solar Analyst, a partir de um MDE interpolado de cartas topográficas na escala 1:50.000.
Séries temporais de NDVI do sensor SPOT Vegetation e algoritmo SAM aplicados ao mapeamento de cana‑de‑açúcar
Authors: Vicente Luiz Eduardo , Gomes Daniel , Victoria Daniel de Castro , Garçon Edlene Aparecida Monteiro , Bolfe Édson Luis , Andrade Ricardo Guimarães , Silva Gustavo Bayma Siqueira da
Published: November 2012

O objetivo deste trabalho foi avaliar o mapeamento de área de cana‑de‑açúcar por meio de série temporal, de seis anos de dados do índice de vegetação por diferença normalizada (NDVI), oriundos do sensor Vegetation, a bordo do satélite "système pour l'observation de la Terre" (SPOT). Três classes de cobertura do solo (cana‑de‑açúcar, pasto e floresta), do Estado de São Paulo, foram selecionadas como assinaturas espectro‑temporais de referência, que serviram como membros extremos ("endmembers") para classificação com o algoritmo "spectral angle mapper" (SAM). A partir desta classificação, o mapeamento da área de cana‑de‑açúcar foi realizado com uso de limiares na imagem-regra do SAM, gerados a partir dos valores dos espectros de referência. Os resultados mostram que o algoritmo SAM pode ser aplicado a séries de dados multitemporais de resolução moderada, o que permite eficiente mapeamento de alvo agrícola em escala mesorregional. Dados oficiais de áreas de cana‑de‑açúcar, para as microrregiões paulistas, apresentam boa correlação (r² = 0,8) com os dados obtidos pelo método avaliado. A aplicação do algoritmo SAM mostrou ser útil em análises temporais. As séries temporais de NDVI do sensor SPOT Vegetation podem ser utilizadas para mapeamento da área de cana‑de‑açúcar em baixa resolução.
Análise espacial dos fatores da equação universal de perda de solo em área de nascentes
Authors: Miqueloni Daniela Popim , Bueno Célia Regina Paes , Ferraudo Antonio Sergio
Published: November 2012

O objetivo deste trabalho foi avaliar a perda de solo de área de nascentes da Microbacia do Córrego do Tijuco, SP. Foi utilizada a análise espacial dos fatores da equação universal da perda de solo (EUPS), em integração com análise de componentes principais e geoestatística. A perda de solo média, estimada para a área, foi de 118,5 Mg ha‑1 por ano, considerada alta. Próximo à zona urbana, houve alta interação dos fatores erosividade da chuva e práticas conservacionistas, o que evidencia grande perda de solo, em razão da concentração da água proveniente da camada impermeabilizada urbana, com alta velocidade de escoamento. Nos divisores de águas, a atuação da erodibilidade foi proeminente, em contraste com o fator topográfico. Foram observadas áreas com atuação conjunta destes fatores, inclusive em locais de inclinação suave, porém com alto potencial natural de erosão. A interação das análises multivariadas e geoestatística permite a estratificação da área, identifica locais com propriedades específicas quanto à perda de solo, e espacializa os fatores do processo erosivo e suas interações ao longo do relevo.