Conserving Nature; Preserving Identity

Fundamental approaches to environmental ethics currently seem polarized between two broad varieties: the “conservationist” approach on which we should conserve the environment when it is in our interest to do so and the “preservationist” approach on which we should preserve the environment even when it is not in our interest to do so. The first approach obviously has a broader potential audience and is invoked even by preservationists when they seek to marshal the broadest possible support for environmental protection. For preservationists, however, the conservationist approach has obvious limitations. It permits damage to the environment whenever required by the balance of human interests. It does not express the real reasons we must protect nonhuman animals, streams, or forests. Preservationists believe that harm to sentient beings, to teleological centers of life, and even to ecological communities should be prevented independently of whether of not it also harms our interests. To conservationists, the idea that the environment ought to be preserved even when it is not in our interest to preserve it often appears inscrutable or flaky. They believe that nature is a precious resource that we should use wisely but when it is not in our interest to conserve nature they do not believe we must do so. Preservationists would object that consideration of human interests does not amount to due consideration of everything that has value. But, it is unclear what preservationists can say to change conservationists’ minds on the matter. In this essay we deploy a third approach to dealing with environmental problems “relationalism.” Like conservationism, this approach tells us to conserve nature when doing so is necessary to respect people in the right way. Unlike conservationism, it does not so prescribe on the basis of a cost-benefit analysis of what would best satisfy our current interests. Like preservationism this approach tells us to preserve nature even when it is not necessary to do so to protect human interests. Relationalism, rather, tells us to preserve nature as part of what makes us who we are or could be. Relationalism starts from a relational conception of human identity. The basic idea is that the nonhuman world may enter into who we are, just as other human beings and communities may enter into who we are. If we, as persons, have value, whatever is bound up with us in positive ways ought also be valued and this gives us reason to conserve or preserve nature. After setting out the relationalist account, we argue that it can explain key preservationist and conservationist intuitions, though its policy recommendations in particular cases may coincide with neither

Investigation of Mn and Fe Substitution Effects on the Characteristics of High-Voltage LiCo1–xMxPO4 (x=0.1, 0.4) Cathodes Prepared by Sol–gel Route

Herein, we provide a fundamental study revealing the substantial changes promoted by manganese and iron substitution for cobalt in a high-voltage LiCoPO4 olivine cathode. Therefore, LiCoPO4, LiCo0.9Fe0.1PO4, LiCo0.6Fe0.4PO4, LiCo0.9Mn0.1PO4, and LiCo0.6Mn0.4PO4 are synthesized by a sol–gel pathway and comparatively investigated in terms of structure, morphology, and electrochemical features in lithium battery. Besides the observed effects on structure, particle size, and metals distribution, the work reveals a gradually enhancing electrode reaction by increasing the Fe content in LiCo0.9Fe0.1PO4 and LiCo0.6Fe0.4PO4, with Co3+/Co2+ and Fe3+/Fe2+ signatures at 4.8 and 3.5 V vs Li+/Li, respectively. On the other hand, the introduction of Mn leads to a progressive electrode deactivation in LiCo0.9Mn0.1PO4 and LiCo0.6Mn0.4PO4 due to an intrinsic hindering of the Mn3+/Mn2+ process at 4.1 V vs Li+/Li. The reasons accounting for such an intriguing behavior are investigated in detail using electrochemical impedance spectroscopy within the potential range of the redox processes. The study reveals that manganese and iron substitutions in the high-voltage olivine have opposite effects on the charge transfer resistance, i.e., detrimental for the former while beneficial for the latter, with remarkable enhancement of the reversible capacity, the Coulombic efficiency, and the cycle life. Such results provide to the scientific community useful information on possible strategies to enhance the emerging LiCoPO4 high-voltage electrode by transition metal substitution

Characteristics of a gold-doped electrode for application in high-performance lithium-sulfur battery

Bulk sulfur incorporating 3 wt% gold nano-powder is investigated as possible candidate to maximize the fraction of active material in the Li-S battery cathode. The material is prepared via simple mixing of gold with molten sulfur at 120 °C, quenching at room temperature, and grinding. Our comprehensive study reports relevant electrochemical data, advanced X-ray computed tomography (CT) imaging of the positive and negative electrodes, and a thorough structural and morphological characterization of the S:Au 97:3 w/w composite. This cathode exhibits high rate capability within the range from C/10 to 1C, a maximum capacity above 1300 mAh gS−1, and capacity retention between 85% and 91% after 100 cycles at 1C and C/3 rates. The novel formulation enables a sulfur fraction in the composite cathode film as high as 78 wt%, an active material loading of 5.7 mg cm−2, and an electrolyte/sulfur (E/S) ratio of 5 μL mg−1, which lead to a maximum areal capacity of 5.4 mAh cm−2. X-ray CT at the micro- and nanoscale reveals the microstructural features of the positive electrode that favor fast conversion kinetics in the battery. Quantitative analysis of sulfur distribution in the porous cathode displays that electrodeposition during the initial cycle may trigger an activation process in the cell leading to improved performance. Furthermore, the tomography study reveals the characteristics of the lithium anode and the cell separator upon a galvanostatic test prolonged over 300 cycles at a 2C rate

Degradation of Layered Oxide Cathode in a Sodium Battery: A Detailed Investigation by X-Ray Tomography at the Nanoscale

The degradation mechanism in a sodium cell of a layered Na0.48Al0.03Co0.18Ni0.18Mn0.47O2 (NCAM) cathode with P3/P2 structure is investigated by revealing the changes in microstructure and composition upon cycling. The work aims to rationalize the gradual performance decay and the alteration of the electrochemical response in terms of polarization, voltage signature, and capacity loss. Spatial reconstructions of the electrode by X-ray computed tomography at the nanoscale supported by quantitative and qualitative analyses show fractures and deformations in the cycled layered metal-oxide particles, as well as inorganic side compounds deposited on the material. These irreversible morphological modifications reflect structural heterogeneities across the cathode particles due to formation of various domains with different Na+ intercalation degrees. Besides, X-ray photoelectron spectroscopy data suggest that the latter inorganic species in the cycled electrode are mainly composed of NaF, Na2O, and NaCO3 formed by parasitic electrolyte decomposition. The precipitation of these insulating compounds at the electrode/electrolyte interphase and the related structural stresses induced in the material lead to a decrease in cathode particle size and partial loss of electrochemical activity. The retention of the NCAM phase after cycling suggests that electrolyte upgrade may improve the performance of the cathode to achieve practical application for sustainable energy storage

The role of synthesis pathway on the microstructural characteristics of sulfur-carbon composites: X-ray imaging and electrochemistry in lithium battery

Two synthesis pathways are adopted to tune the microstructural characteristics of sulfur-carbon (S-C) composites for application in lithium-sulfur (Li-S) batteries. Both methods include intimate mixing of either carbon black or multiwalled carbon nanotubes with elemental sulfur, molten according to the first approach while dispersed in alcohol and heated according to the second one. Nano- and micro-scale X-ray computed tomography supported by X-ray diffraction and electron microscopy shows materials consisting of crystalline sulfur clusters (70 wt%) with size ranging from about 5 to 50 μm, surrounded by carbon. The sulfur cluster size appears limited by direct mixing of molten sulfur and carbons, in particular when carbon black is employed, whilst it is increased by exploiting the alcohol dispersion. Electrochemistry reveals that small sulfur particles lead to an improved rate capability in Li-S cells, whereas large active material domains may favor the capacity retention. The composites using carbon black nanoparticles exhibit the highest reversible capacity, with a maximum value exceeding 1500 mAh gS−1, whereas the composites involving multiwalled carbon nanotubes show the best capacity retention, with values approaching 70% over 150 cycles. Our multi-disciplinary approach will shed light on significant aspects aiming to enhance the Li-S battery and favor a practical application

Making Free Trade Fair

Philosophers have done very little work on what makes trade fair. Perhaps the most extensive discussion is Malgorzata Kurjanska and Mathias Risse’s article, “Fairness in Trade II: export subsidies and the fair trade movement.”2 In their article, Kurjanska and Risse consider the case for trade subsidies and the Fair Trade movement. They suggest that it is not permissible for developed countries to give their producers subsidies because doing so does not strike an appropriate balance between meeting the needs of the global poor and protecting domestic workers (Kurjanska and Risse, 2008: 34). Kurjanska and Risse also argue that the case for Fair Trade hinges, primarily, on whether or not it is part of the best development strategy for poor countries. They do not think Fair Trade is part of the best development strategy and, so, they believe purchasing Fair Trade certified goods is only acceptable because doing so does not constitute a large share of the market in traded goods. This chapter argues that the case against subsidies and Fair Trade Kurjanska and Risse present is much weaker than they make out. To the contrary, it argues that giving some subsidies and purchasing some Fair Trade certified goods may even be necessary to make trade fair. Section 11.2 starts by saying a few words about the normative framework Kurjanska and Risse adopt

The Classical Limit of Quantum Mechanics and the Fejer Sum of the Fourier Series Expansion of a Classical Quantity

In quantum mechanics, the expectation value of a quantity on a quantum state, provided that the state itself gives in the classical limit a motion of a particle in a definite path, in classical limit goes over to Fourier series form of the classical quantity. In contrast to this widely accepted point of view, a rigorous calculation shows that the expectation value on such a state in classical limit exactly gives the Fej\'{e}r's arithmetic mean of the partial sums of the Fourier series

New lithium ion batteries exploiting conversion/alloying anode and LiFe₀.₂₅Mn₀.₅Co₀.₂₅PO₄ olivine cathode

New Li-ion cells are formed by combining a LiFe₀.₂₅Mn₀.₅Co₀.₂₅PO₄ olivine cathode either with Sn-Fe₂O₃-C composite anodes. These active materials exhibit electrochemical properties very attractive in view of practical use, including the higher working voltage of the LiFe₀.₂₅Mn₀.₅Co₀.₂₅PO₄ cathode with respect to conventional LiFePO₄, as well as the remarkable capacity and rate capability of Sn-Fe₂O₃-C and Sn-C anodes. The stable electrode/electrolyte interfaces, demonstrated by electrochemical impedance spectroscopy, along with proper mass balancing and anode pre-lithiation, allow stable galvanostatic cycling of the full cells. The two batteries, namely Sn-Fe₂O₃-C/LiFe₀.₂₅Mn₀.₅Co₀.₂₅PO₄ and Sn-C/LiFe₀.₂₅Mn₀.₅Co₀.₂₅PO₄, reversibly operate revealing promising electrochemical features in terms of delivered capacity, working voltage and stability, thus suggesting these electrodes combinations as suitable alternatives for an efficient energy storage

Electrochemical features of LiMnPO₄ olivine prepared by sol-gel pathway

LiMnPO₄ is a potential cathode for lithium-ion battery of high thermal stability, low cost, environmental sustainability and high theoretical energy density. However, this intriguing olivine material suffers from intrinsic sluggish kinetics of lithium (de-)insertion, which limits the reversible reaction in practical lithium cells. Herein we report a careful study of the impedance features of LiMnPO₄ during electrochemical reaction in lithium cell. The LiMnPO₄ material is prepared by sol-gel method and fully characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The material shows suitable galvanostatic cycling with a working voltage of about 4.1 V, which is higher than the 3.5 V value expected from the most common olivine material, i.e., LiFePO₄. Hence, electrochemical impedance spectroscopy (EIS) is used to study the lithium (de-)insertion within the LiMnPO₄ structure. The results indicate an impedance behavior depending on the state of charge and a lithium diffusion coefficient trend slightly decreasing during cell operation within the 10⁻¹⁴ – 10⁻¹³ cm² s⁻¹ range. The electrochemical study in lithium cell reveals remarkable enhancement of the electrode kinetics at 70 °C, which suggests preferred application of LiMnPO₄ materials at the higher temperatures

Analysis of Bidirectional Associative Memory using SCSNA and Statistical Neurodynamics

Bidirectional associative memory (BAM) is a kind of an artificial neural network used to memorize and retrieve heterogeneous pattern pairs. Many efforts have been made to improve BAM from the the viewpoint of computer application, and few theoretical studies have been done. We investigated the theoretical characteristics of BAM using a framework of statistical-mechanical analysis. To investigate the equilibrium state of BAM, we applied self-consistent signal to noise analysis (SCSNA) and obtained a macroscopic parameter equations and relative capacity. Moreover, to investigate not only the equilibrium state but also the retrieval process of reaching the equilibrium state, we applied statistical neurodynamics to the update rule of BAM and obtained evolution equations for the macroscopic parameters. These evolution equations are consistent with the results of SCSNA in the equilibrium state.Comment: 13 pages, 4 figure