• Energy Research
• Closed Access close
• US close
• AU close
• IN close
• English close

Moral panic, our predisposition to exaggerate threats against our livelihood and start blaming ourselves, is as old as human history. We always feared “others”, people with skin colors or ethnicity other than ours, people coming from other corners of the globe, and the infectious diseases the strangers might bring along. This paper deals with a new version of such moral panics which is arguably even more intense than the previous ones, but which relates to a new dimension of human experience, namely globalization. The health, economic and environmental challenges we are now faced with are posed globally. The moral panic today stems from this triple challenge. Our central thesis is that these three emergencies are interrelated, but there is no simple causal relationship between them. They can only be addressed in a global manner, while we still live in a world which is segmented into sovereign nation-states.

To more accurately treat severe accidents in fast reactors, a program has been set up to investigate new computational models and approaches. The product of this effort is a computer code, the Advanced Fluid Dynamics Model (AFDM). This paper describes some of the basic features of the numerical algorithm used in AFDM. Aspects receiving particular emphasis are the fractional-step method of time integration, the semi-implicit pressure iteration, the virtual mass inertial terms, the use of three velocity fields, higher order differencing, convection of interfacial area with source and sink terms, multicomponent diffusion processes in heat and mass transfer, the SESAME equation of state, and vectorized programming. A calculated comparison with an isothermal tetralin/ammonia experiment is performed. We conclude that significant improvements are possible in reliably calculating the progression of severe accidents with further development.

This paper describes the modeling used in the Advanced Fluid Dynamics Model (AFDM), a computer code to investigate new approaches to simulating severe accidents in fast reactors. The AFDM code has 12 topologies describing what material contacts are possible depending on the presence or absence of a given material in a computational cell, the dominant liquid, and the continuous phase. Single-phase, bubbly, churn-turbulent, cellular, and dispersed flow are permitted for the pool situations modeled. Interfacial areas between the continuous and discontinuous phases are convected to allow some tracking of phenomenological histories. Interfacial areas also are modified by models of nucleation, dynamic forces, turbulence, flashing, coalescence, and mass transfer. Heat transfer generally is treated using engineering correlations. Liquid/vapor phase transitions are handled with a nonequililbrium heat-transfer-limited model, whereas melting and freezing processes are based on equilibrium considerations. The Los Alamos SESAME equation of state (EOS) has been inplemented using densities and temperatures as the independent variables. A summary description of the AFDM numerical algorithm is provided. The AFDM code currently is being debugged and checked out. Two sample three-field calculations also are presented. The first is a three-phase bubble column mixing experiment performed at Argonne National Laboratory; the second is a liquid-liquid mixing experiment performed at Kernforschungszentrum, Karlsruhe, that resulted in rapid vapor production. We conclude that only qualitative comparisons currently are possible for complex multiphase situations. Many further model developments can be pursued, but there are limits because of the lack of a comprehensive theory, the lack of detailed multicomponent experimental data, and the difficulties in keeping the resulting model complexities tractable.

Agriculture, Forestry, and Other Land Use (AFOLU) is unique among the sectors considered in this volume, since the mitigation potential is derived from both an enhancement of removals of greenhouse gases (GHG), as well as reduction of emissions through management of land and livestock (robust evidence; high agreement). The land provides food that feeds the Earth’s human population of ca. 7 billion, fibre for a variety of purposes, livelihoods for billions of people worldwide, and is a critical resource for sustainable development in many regions. Agriculture is frequently central to the livelihoods of many social groups, especially in developing countries where it often accounts for a significant share of production. In addition to food and fibre, the land provides a multitude of ecosystem services; climate change mitigation is just one of many that are vital to human well-being (robust evidence; high agreement). Mitigation options in the AFOLU sector, therefore, need to be assessed, as far as possible, for their potential impact on all other services provided by land. [Section 11.1]

Producing ions from large molecules is of distinguished importance in mass spectrometry. In our present study we survey different laser desorption methods in view of their virtues and drawbacks in volatilization and ion generation. Laser induced thermal desorption and matrix assisted laser desorption are assessed with special emphasis to the recent breakthrough in the field (m/z > 100,000 ions produced by matrix assisted laser desorption). Efforts to understand and describe laser desorption and ionization are also reported. We emphasize the role of restricted energy transfer pathways as a possible explanation to the volatilization of non-degraded large molecules.

Abstract Energy storage is equally important as energy production. The modern human society demands lightweight, flexible, inexpensive and environment friendly energy storage systems. Batteries are the major energy storage devices, but slow charge-discharge rate, short life cycles and bulkiness of battery limit its applications in portable and wearable devices. Lately, supercapacitors have been receiving a great attention as alternative energy storage devices because of their distinctive features such as high power density, light weight, fast charging-discharging rate, secure operation and long life span. Supercapacitors, also called electrochemical capacitors, are already being used in various applications such as hybrid vehicles, power back up, military services and portable electronics like laptops, mobile phones, wrist watches, wearable devices, roll-up displays, electronic papers, etc. The materials utilized in the supercapacitors play a prominent role, because the performance of supercapacitors depends on its properties. Specific capacitance of a supercapacitor depends on the surface area and the pore size distribution of the electrode material used for its fabrication. Compared with the transition metal oxides and conducting polymers, carbon and its different types provide larger surface area. However, this high surface area of carbon is not completely accessible for the electrolyte. In this context, metal oxide nanostructures are considered quite attractive candidates in energy storage applications due to their unique properties. Metal oxide nanostructures based energy storage devices have been shown to exhibit superior electrochemical performance due to their high surface to volume ratio and high mechanical flexibilities. The supercapacitor performance depends on morphology and oxidation state of metal oxide. Metal oxides such as RuO2, MnO2, TiO2, NiO, CoO, CuO, and composite materials are potential candidates for supercapacitor applications. RuO2 and MnO2 are the prominent electrode materials due to higher energy density with higher theoretical capacitance of about 1450 and 1270 F/g, respectively. RuO2 limits its utilization being scarce, extremely expensive (5000/- @1g) and toxic to some extent. At the same time MnO2 has its own benefits like cheap material cost, plentiful availability in the earth’s crust, and environmental friendliness. However, the conductivity of MnO2 is much lower ranging from 10-7 to10-3 S/cm. The main advantage of MnO2 is that it shows much higher specific capacitance with aqueous electrolytes as compared to other gel or solid electrolytes. But associated with this advantage is the problem that MnO2 is soluble in water and cell becomes dead after a few charging and discharging cycles. The previous reported studies suggest that MnO2 electrode supercapacitors (when material is synthesised by hydrothermal method without a surfactant) show low cyclic stability and specific capacitance. Triethanolamine (TEA) is a good surfactant for synthesis of metal oxides but has not been used for synthesis of MnO2. It is possible to synthesise MnO­2 nanostructures with desirable crystalline structures and morphology using TEA as surfactant, which won’t dissolve in water over high number of charge-discharge cycles. The aim of this study is to synthesize the metal oxide based manganese nanostructure material to explore its applicability as the electrode in supercapacitor. For this, b-MnO2 nanostructures have been synthesized via TEA assisted hydrothermal method at different reaction temperatures. Silver doped MnO2 nanocomposite and Carbon-MnO2 composite electrode materials have also been synthesized by hydrothermal method expecting enhanced electrochemical performance of the cell. The structural and crystallite size study of the materials have been carried out using X- ray diffraction (XRD). The morphological studies have been carried out by using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). X-ray Photoelectron Spectroscopy (XPS) analysis is performed for material purity, quantity and binding energy of those elements that are present within the top 1-12 nm of the sample surface. Fourier Transform Infrared Spectroscopy (FTIR) investigation has been undertaken to identify the functional groups in the material. Supercapacitors have been fabricated using the electrodes which are prepared with the various synthesized β-MnO2 and its composite materials. The electrochemical performance has been tested with three different analytical tools including cyclic voltammetry, galvanostatic charge discharge and electrochemical impedance spectroscopy. XRD data of MnO2 samples are in agreement with JCPDS card no. 81-2261, which suggests the formation of β-MnO2 tetragonal planes with lattice parameters a = b = 4.3985 Å and c = 2.8701 Å. The intensity of the diffraction peaks is found to increase as the synthesis temperature is increased from 60℃ to 120. XPS analysis of β-MnO2 sample synthesised at 120℃ reveals the surface oxidation state of manganese with Mn4+ 2P3/2 and Mn4+ 2P1/2 peaks located at 642.1 eV and 652.5 eV. SEM micrographs suggested that the temperature of synthesis affects the surface morphology and nanorods structure of MnO2 and that the high surface area and porous β-MnO2 nanorods are developed by hydrothermal synthesis at the reaction temperature near 100℃. The porosity of the nanostructures assists in better ion transportation in the electrode and improves the contact area for electrolyte ions to perform rapid surface redox reactions. Selected Area Electron Diffraction (SAED) pattern of β-MnO2 showed crystal planes at (110), (101), (210), (220), and (301) with interplanar spacing 3.109 Å, 2.403 Å, 1.959 Å, 1.555 Å, and 1.300 Å, respectively in agreement with the results obtained from XRD. FTIR exhibited the MnO2 vibrational bands at 707.1 and 529.2 cm-1. As expected, the β-MnO2 nanorods analysed as supercapacitor electrode in 1M Na2SO4 liquid electrolyte exhibited high specific capacitance of 89.63, 128.05, 461.59 and 288.72 F/g at a scan rate of 10 mV/s (on a wide potential window of 0-0.8 V) for the sample synthesized at temperatures 60℃, 80℃, 100℃ and 120℃, respectively. The best performance is observed for electrode of the MnO2 synthesised at 100℃, which can be attributed to large surface area (due to larger size nanorods) available for charge-storage and for redox-reactions (pseudocapacitive type of charge-storage). The energy densities recorded are 7.11, 10.55, 38.89 and 30.67 Wh/Kg at a power density of 0.4 kW/Kg. The morphological analysis of Ag doped MnO2 performed by SEM revealed a particle size of about 50 nm. The highest specific capacitance is found to be 523.91 F/g at the scan rate 10 mV/s (on a potential window of 0-0.8 V). Doping of Ag in MnO2 increases the specific capacitance of the supercapacitor as compared to pure MnO2 nanorods. Carbon-MnO2 supercapacitor has given specific capacitance value (560 F/g at scan rate 10 mV/s on a potential window of 0-0.8 V) which is even higher than AgMnO2 electrode based symmetric supercapacitor. The specific capacitance increases as carbon has higher surface area leading to increased adsorption of ions on the surface of electrode. The thesis also suggests various extended research options like different electrolytes, other electrode materials and fabrication of asymmetric supercapacitors aiming at further enhanced and desirable characteristics.

The backscattered electron coefficient is known to be primarily dependent on the atomic number of the sample. If the atomic number increases, the backscattered electron coefficient increases, which results in a higher intensity in the backscattered electron image. The dependence of the primary electron energy is somewhat more complicated. Using photographic material (with composition AgBr-AgI), it is seen that the contrast in the backscattered electron image increases with the primary electron energy. Using three independent methods, based on image analysis techniques, it is shown that the difference between the backscattered electron coefficient of AgBr and AgI increases with the primary electron energy in the range from 40 to 100 keV.

Anthropogenic climate change is predicted to be a major cause of extinctions. Therefore, a major aim of climate change ecology is to understand how species are being impacted and identify which species are most at risk. However, the ability to make these broad generalisations requires large-scale comparative analyses based on appropriate assumptions. This thesis investigates how European birds respond to changes in climate, the validity of several common assumptions, and identifies which species or populations are most at risk based on multiple long-term datasets. Our understanding of how different responses relate and how they affect population persistence is lacking. A conceptual hierarchical framework is introduced in chapter one to better understand and predict when climate-induced trait changes (phenology or physiology) impact demographic rates (survival or reproduction), and subsequently population dynamics. I synthesise the literature to find hypotheses about life-history and ecological characteristics that could predict when population dynamics will likely be affected. An example shows that, although earlier laying with warmer temperatures was associated with improved reproduction, this had no apparent effect on population trends in 35 British birds. Number of broods partly explains which species are most at risk of temperature-induced population declines. It is often assumed that populations within species respond similarly to climate change, and therefore a single value will reflect species-specific responses. Chapter two explores inter- and intra-specific variation in body condition responses to six climatic variables in 46 species over 21 years and 80 sites. Body condition is sensitive to all six variables (primarily in a non-linear way), and declines with warmer temperatures. I find that species signals might not exist as populations of the same species are no more alike than populations of different species. Decreased body condition is typically assumed to have detrimental consequences on species’ vital rates and population dynamics, but this assumption has rarely been tested. Expanding on chapter two, chapter three shows that temperature-induced declines in body condition have no apparent consequences on demography and population dynamics. Instead, temperature has strong effects on reproductive success and population growth rates via unknown traits and demographic rates. Much of the literature investigating climatic impacts assumes that temporal trends accurately reflect responses to climate change, and therefore investigate trait changes over time. In chapter four, I use two long-term datasets to demonstrate that, for four different types of trait responses, trait variation through time cannot be assumed to be due to warming. Non-temperature causal agents are important…

This paper presents some recent results obtained from the COMMIX-1A code for the EBR-II reactor transient No. 10, Phase 2. Both the reactor vessel and the neutron shield assembly and assembly arrangement in the reactor core are shown. The computational grid system used in COMMIX-1A is presented. Reactor flow and power transients are shown. Velocity and temperature distributions at steady state and t (time) = 60 sec are included. Finally, a comparison between the calculated results from COMMIX-1A and experimental measurements are presented for outlet temperatures for driver subassembly of XX08, top-of-core temperature for driver subassembly of XX08, and low-pressure plenum mass flow respectively.