5,143 research outputs found

    Wake up and smell the coffee, or find the technoserf dead

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    This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.CLW_2011_Report_China_wake_up.pdf: 59 downloads, before Oct. 1, 2020

    Solid state lasers for use in non-contact temperature measurements

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    The last decade has seen a series of dramatic developments in solid state laser technology. Prominent among these has been the emergence of high power semiconductor laser diode arrays and a deepening understanding of the dynamics of solid state lasers. Taken in tandem these two developments enable the design of laser diode pumped solid state lasers. Pumping solid state lasers with semiconductor diodes relieves the need for cumbersome and inefficient flashlamps and results in an efficient and stable laser with the compactness and reliability. It provides a laser source that can be reliably used in space. These new coherent sources are incorporated into the non-contact measurement of temperature. The primary focus is the development and characterization of new optical materials for use in active remote sensors of the atmosphere. In the course of this effort several new materials and new concepts were studied which can be used for other sensor applications. The general approach to the problem of new non-contact temperature measurements has had two components. The first component centers on passive sensors using optical fibers; an optical fiber temperature sensor for the drop tube was designed and tested at the Marshall Space Flight Center. Work on this problem has given insight into the use of optical fibers, especially new IR fibers, in thermal metrology. The second component of the effort is to utilize the experience gained in the study of passive sensors to examine new active sensor concepts. By active sensor are defined as a sensing device or mechanism which is interrogated in some way be radiation, usually from a laser. The status of solid state lasers as sources for active non-contact temperature sensors are summarized. Some specific electro-optic techniques are described which are applicable to the sensor problems at hand. Work on some of these ideas is in progress while other concepts are still being worked out

    Who Should Bear the Cost of China’s Carbon Emissions Embodied in Goods for Exports?

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    China’s capital-intensive, export-oriented, spectacular economic growth since launching its open-door policy and economic reforms in late 1978 not only has created jobs and has lifted millions of the Chinese people out of poverty, but also has given rise to unprecedented environmental pollution and CO2 emissions. While estimates of the embedded CO2 emissions in China’s trade differ, both single country studies for China and global studies show a hefty chunk of China’s CO2 emissions embedded in trade. This portion of CO2 emissions had helped to turn China into the world’s largest carbon emitter, and is further widening its gap with the second largest emitter. This raises the issue of who should be responsible for this portion of emissions and bearing the carbon cost of exports. China certainly wants importers to cover some, if not all, of those costs. While China’s stance is understandable, this paper has argued from a broad and balanced perspective that if this is pushed too far, it will not help to find solutions to this issue. On the contrary it can be to China’s disadvantage for a number of reasons. However, aligning this responsibility with China does not necessarily suggest the sole reliance on domestic actions. In that context, the paper recommends specific actions that need to be taken internationally as well as domestically in order to effectively control the embedded CO2 emissions in China’s trade.Emissions Embodied In Trade, Consumption-Based Accounting, Production-Based Accounting, Processing Trade; Carbon Tariffs, Energy Policy

    Silicone elastomers filled with rare earth oxides

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    Silicones which possess, amongst others, remarkable mechanical properties, thermal stability over a wide range of temperatures and processability, and rare earth oxides(REO), known for their unique optic, magnetic and catalytic properties can be coupled into multifunctional composite materials(SREOs). In addition, the intrinsic hydrophobicity of REO and polysiloxanes makes them easily compatible without the need for surface treatments of the former. Thus, europium oxide (Eu2O3), gadolinium oxide (Gd2O3) and dysprosium oxide (Dy2O3)in amounts of 20 pph are incorporated as fillers into silicone matrices, followed by processing mixture as thin films and crosslinking at room temperature. The analysis of the obtained films reveals the changes induced by these fillers in the thermal, mechanical, dielectric and optical properties, as well as the hydrophobicity of the silicones. The luminescence properties of S-REO composites were investigated by fluorescence spectra and lifetime - resolved measurements with a multiemission peaks from blue to greenish register. The thermogravimetrical analysis indicates an increasing of thermal stability of the composites that contain REO, compared to pure silicone. As expected, the dielectric permittivity significantly increased due to nature of the fillers, while the dielectric loss values are relatively low for all samples, indicating a minimal conversion of electrical energy in the form of heat within bulk composites. The presence of rare earth oxides into the silicone matrix facilitates the motions of long-range charge carriers through the network resulting in higher values of conductivity of the composite films. The stress-strain measurements revealed the reinforcing effect of the rare earth metal oxides on a silicone matrix, leading to a significant increase of Young modulus. The known hydrophobicity of silicones is further enhanced by the presence of REO

    Integrated micro X-ray fluorescence and chemometric analysis for printed circuit boards recycling

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    A novel approach, based on micro X-ray fluorescence (μXRF), was developed to define an efficient and fast automatic recognition procedure finalized to detect and topologically assess the presence of the different elements in waste electrical and electronic equipment (WEEE). More specifically, selected end-of-life (EOL) iPhone printed circuit boards (PCB) were investigated, whose technological improvement during time, can dramatically influence the recycling strategies (i.e. presence of different electronic components, in terms of size, shape, disposition and related elemental content). The implemented μXRF-based techniques allow to preliminary set up simple and fast quality control strategies based on the full recognition and characterization of precious and rare earth elements as detected inside the electronic boards. Furthermore, the proposed approach allows to identify the presence and the physical-chemical attributes of the other materials (i.e. mainly polymers), influencing the further physical-mechanical processing steps addressed to realize a pre-concentration of the valuable elements inside the PCB milled fractions, before the final chemical recovery

    China, The World Trade Organization, And The Market For Rare Earth Minerals

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    Rare earth elements (also referred to as rare earth minerals, rare earth metals, green elements, rare earths or simply REEs) are comprised of 17 elements of the periodic table. The metals are often found combined together in ores and must be separated into its individual elements. On the supply side of the market, China is currently the largest producer of rare earth elements in the world, mining at least 90% of total world production. Consequently, many countries around the world rely on imports of these REEs to facilitate production of the various systems and products that are dependent on the rare earth metals as raw materials. With one supplier effectively monopolizing the rare earth industry, this imposes severe supply-chain risks to the producers of products that rely on rare earth minerals. After several actions that have restricted the supply, the United States, the European Union, and Japan have challenged China for violating provisions of its membership in the World Trade Organization. This paper will examine the rare earth industry, China’s near-monopoly, global supply-chain risks, and strategies to reduce dependence on China, including the invocation of the WTO’s dispute resolution process

    Rare Metals Extraction from Non-ferrous Resources in India: Present Status and Prospects of R&D

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    Rare metals comprise of those naturally occurring elements with relatively lesser abundance in the earth 's crust which are difficult to extract by normal metallurgical processes. The present paper summarizes the ore / mineral resource base including the secondary resources, current usage and extraction technology of rare metals in India. The R&D in India has resulted in the exploitation of such processes or poised for gainful utilization. As the tech-nologies for extraction of rare metals follow a different methodology than those applicable to the normal base metals and were not readily available at the early stage of development during 1950-1990s, indigenous developments matured and were put to use; a few such technologies are described. Mention may be made of the applications of special processing options such as: halide metallurgy, strong acid / alkali treatment for breaking down the refractory minerals FIF/ alkali fusion ; solvent extra-ction/ ion exchange for metal separation, and vacuum melting/ electron beam melting/ refining etc for melting/ refining, to meet the stringent specifications of the rare metals . In most cases, extraction is carried out using primary resources , but for metals not present in a substantial quantity in natural ores or in diffused state, secondary resources are exploited. Secondary resources are particularly criticalfor Ga, V, Mo, W, Se, Te etc. Possi- bilities for further research are indicated to ensure secured supply ofthese metals in future

    A chemical model for lunar non-mare rocks

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    Nearly all rocks returned from the moon are readily divided into three broad categories on the basis of their chemical compositions: (1) mare basalts, (2) non-mare rocks of basaltic composition (KREEP, VHA), and (3) anorthositic rocks. Only mare basalts may unambiguously be considered to have original igneous textures and are widely understood to have an igneous origin. Nearly all other lunar rocks have lost their original textures during metamorphic and impact processes. It is shown that for these rocks one must work primarily with chemical data in order to recognize and define rock groups and their possible modes of origin. Non-mare rocks of basaltic composition have chemical compositions consistent with an origin by partial melting of the lunar interior. The simplest origin for rocks of anorthositic chemical composition is the crystallization and removal of ferromagnesian minerals. It is proposed that the rock groups of anorthositic and non-mare basaltic chemical composition could have been generated from a single series of original but not necessarily primitive lunar materials

    A chemical model for lunar non-mare rocks

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    Nearly all rocks returned from the moon are readily divided into three broad categories on the basis of their chemical compositions: (1) mare basalts, (2) non-mare rocks of basaltic composition (KREEP, VHA), and (3) anorthositic rocks. Only mare basalts may unambiguously be considered to have original igneous textures and are widely understood to have an igneous origin. Nearly all other lunar rocks have lost their original textures during metamorphic and impact processes. For these rocks one must work primarily with chemical data in order to recognize and define rock groups and their possible modes of origin. Non-mare rocks of basaltic composition have chemical compositions consistent with an origin by partial melting of the lunar interior. The simplest origin for rocks of anorthositic chemical composition is the crystallization and removal of ferromagnesian minerals. It is proposed that the rock groups of anorthositic and non-mare basaltic chemical composition could have been generated from a single series of original, but not necessarily primitive, lunar materials
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