Interplay between multiple scattering, emission, and absorption of light in the phosphor of a white light-emitting diode

We study light transport in phosphor plates of white light-emitting diodes (LEDs). We measure the broadband diffuse transmission through phosphor plates of varying YAG:Ce$^{3+}$ density. We distinguish the spectral ranges where absorption, scattering, and re-emission dominate. Using diffusion theory, we derive the transport and absorption mean free paths from first principles. We find that both transport and absorption mean free paths are on the order of the plate thickness. This means that phosphors in commercial LEDs operate well within an intriguing albedo range around 0.7. We discuss how salient parameters that can be derived from first principles control the optical properties of a white LED.Comment: 14 pages, 9 figure

Applying consumer responsibility principle in evaluating environmental load of carbon emissions

There is a need for a proper indicator in order to assess the environmental impact of international trade, therefore using the carbon footprint as an indicator can be relevant and useful. The aim of this study is to show from a methodological perspective how the carbon footprint, combined with input- output models can be used for analysing the impacts of international trade on the sustainable use of national resources in a country. The use of the input-output approach has the essential advantage of being able to track the transformation of goods through the economy. The study examines the environmental impact of consumption related to international trade, using the consumer responsibility principle. In this study the use of the carbon footprint and input-output methodology is shown on the example of the Hungarian consumption and the impact of international trade. Moving from a production- based approach in climate policy to a consumption-perspective principle and allocation, would also help to increase the efficiency of emission reduction targets and the evaluation of the ecological impacts of international trade

Provincial and sector-level material footprints in China

High-income countries often outsource material demands to poorer countries along with the associated environmental damage. This phenomenon can also occur within (large) countries, such as China, which was responsible for 24 to 30% of the global material footprint (MF) between 2007 and 2010. Understanding the distribution and development of China’s MF is hence critical for resource efficiency and circular economy ambitions globally. Here we present a comprehensive analysis of China’s MF at the provincial and sectoral levels. We combine provincial-level input–output data with sector- and province-specific trade data, detailed material extraction data, and the global input–output database EXIOBASE. We find that some provinces have MFs equivalent to medium-sized, high-income countries and limited evidence of material decoupling. Lower-income regions with high levels of material extraction can have an MF per capita as large as developed provinces due to much higher material intensities. The higher-income south-coastal provinces have lower MF per capita than equally developed provinces. This finding relates partly to differences in economic structure but indicates the potential for improvement across provinces. Investment via capital formation is up to 4 times more resource-intensive than consumption and drives 49 to 86% of provincial-level MFs (the Organisation for Economic Co-operation and Development average is 37%). Resource-efficient production, efficient use of capital goods/infrastructure, and circular design are essential for reductions in China’s MF. Policy efforts to shift to a high-quality development model may reduce material intensities, preferably while avoiding the further outsourcing of high-intensity activities to other provinces or lower-income countries

Moving from a Product-Based Economy to a Service-Based Economy for a More Sustainable Future

Traditionally, economic growth and prosperity have been linked with the availability, production and distribution of tangible goods as well as the ability of consumers to acquire such goods. Early evidence regarding this connection dates back to Adam Smith's Wealth of Nations (1776), in which any activity not resulting in the production of a tangible good is characterized as unproductive of any value." Since then, this coupling of economic value and material production has been prevalent in both developed and developing economies throughout the world. One unintended consequence of this coupling has been the exponential increase in the amount of solid waste being generated. The reason is that any production and consumption of material goods eventually generates the equivalent amount of (or even more) waste. Exacerbating this problem is the fact that, with today's manufacturing and supply chain management technologies, it has become cheaper to dispose and replace most products rather than to repair and reuse them. This has given rise to what some call a disposable society." To put things in perspective: In 2012 households in the U.K. generated approximately 22 thousand tons of waste, which amounted to 411 kg of waste generated per person (Department for Environment, Food & Rural Affairs, 2015). During the same time period, households in the U.S. generated 251 million tons of waste, which is equivalent to a person generating approximately 2 kg of waste every day (U.S. Environmental Protection Agency, 2012). Out of these 251 million tons of total waste generated, approximately 20% of the discarded items were categorized as durable goods. The disposal of durable goods is particularly worrisome because they are typically produced using material from non- renewable resources such as iron, minerals, and petroleum-based raw materials

The manufacturer's value chain as a service - the case of remanufacturing

Manufacturing enterprises globally have already largely adopted the product-service strategy into their operations. However, due to gradual commoditization of services, manufacturing enterprises will have to further extend this strategy. One possibility is for manufacturers to servitize, not only their final products, but also a part of their value chain, with the aim of increasing their long-term competitive advantage. In this article, the application of servitization to remanufacturing, as a set of operational and business competences and processes, is conceptualized. By offering remanufacturing as a service, manufacturers will create an additional revenue stream. The synergies created from integrating remanufacturing into an enterprise with a product-service system are scrutinized. The impact of offering remanufacturing as a service (servitizing) is then assessed from the perspective of the competitive advantage of both, the provider and the consumer of the service. Three main sets of implications are identified. The first is that the integration of remanufacturing into a product-service system could increase customer satisfaction through a larger service scope and higher service quality, while decreasing operational costs. Furthermore, it is shown that the higher the level of servitization, the stronger is the positive impact of remanufacturing. The second set of results shows that servitizing remanufacturing can substantially increase the competitive advantage of both the provider and the consumer. While the first two sets of results have industrially oriented implications, the third set constitutes a theoretical contribution through the proposal and conceptual validation of extension of the application of servitization theory. Finally, while the reasoning is of a conceptual nature, it is based on established theories and includes remanufacturing-related industrial cases as a basis for assessment

The legacy environmental footprints of manufactured capital

Industrial Ecolog