Sustainable agriculture and the production of biomass for energy use     

Adrian Muller 《Climatic change》2009,94(3-4):319-331

Modern bioenergy is seen as a promising option to curb greenhouse gas emissions. There is, however, a potential competition for land and water between bioenergy and food crops. Another question is whether biomass for energy use can be produced in a sustainable manner given the current conventional agricultural production practices. Other than the land and water competition, this question is often neglected in scenarios to meet a significant part of global energy demand with bioenergy. In the following, I address this question. There are sustainable alternatives, for example organic agriculture, to avoid the negative environmental effects of conventional agriculture. Yet, meeting a significant part of global energy demand with biomass grown sustainably may not be possible, as burning significant quantities of organic matter—inherent in bioenergy use—is likely to be incompatible with the principles of such alternatives, which often rely on biomass input for nutrient balance. There may therefore be a trade-off between policies and practices to increase bioenergy and those to increase sustainability in agriculture via practices such as organic farming. This is not a general critique of bioenergy but it points to additional potential dangers of modern bioenergy as a strategy to meet significant parts of world energy demand.  相似文献   

Crustal structure of the Southwest Indian Ridge at 66°E: seismic constraints   总被引：1，自引：0，他引：1  

T. A. Minshull  M. R. Muller  R. S. White 《Geophysical Journal International》2006,166(1):135-147

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Spectroradiometric requirements for the reflective module of the airborne spectrometer ARES     

Muller  A. Richter  R. Habermeyer  M. Dech  S. Segl  K. Kaufmann  H. 《Geoscience and Remote Sensing Letters, IEEE》2005,2(3):329-332

The Airborne Reflective/Emissive Spectrometer is specified as a whisk-broom imaging spectrometer for remote sensing of land surfaces covering the wavelength regions 0.47-2.45 /spl mu/m and 8-12 /spl mu/m with 160 spectral bands. The instrument is being built by Integrated Spectronics, financed by the German Aerospace Agency (DLR) and the GeoResearch Centre Potsdam (GFZ) and will be available to the scientific community from end 2005 on. The spectroradiometric design is based on scientific requirements derived from three main application scenarios comprising vegetation, soil, and mineral sciences. Two of these are described in this letter. Measured or modeled reflectance spectra are input to a simulation model that calculates at-sensor radiance spectra, resamples them with the channel-specific response functions, adds different amounts of noise in the radiance domain, and performs a retrieval to get the corresponding noisy surface reflectance spectra. The retrieval results as a function of the sensor noise level are compared with the accuracy requirements imposed by the different application fields taking into account the technical boundary conditions. The final specifications account for the most demanding requirements of the three application fields: a spectral sampling distance of 13-14 nm in the 470-1800 nm region, and 12 nm in the 2000-2450-nm region. The required noise-equivalent radiances are 5, 3, and 2 nW/spl middot/cm/sup -2//spl middot/sr/sup -1//spl middot/nm/sup -1/ for the spectral regions 470-1000, 1000-1800, and 2000-2450 nm, respectively.  相似文献   

The variation of the mean size of the photospheric granules close to and away from a sunspot     

C. Macris  Th. Prokakis  D. Dialetis  R. Muller 《Solar physics》1989,122(2):209-213

We study the mean size of granules as a function of distance from the boundaries of the sunspot penumbra. We use for the determination of the mean size two different methods, a visual and a photometric. In all cases the mean diameter of the granules away from the spot was greater than the mean diameter of the granules in the neighbourhood of the penumbra. Our study is based on an excellent sequence of photos, taken at the Pic-du-Midi Observatory on May 11, 1979.  相似文献   

GEOGRAPHIC SERIATION REVISITED*     

Jean-Claude Muller 《The Professional geographer》1983,35(2):196-202

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QUALITY ASSESSMENT OF DIGITAL ELEVATION MODELS PRODUCED BY AUTOMATIC STEREOMATCHERS FROM SPOT IMAGE PAIRS     

T. Day  J.-P. A. L. Muller 《The Photogrammetric Record》1988,12(72):797-808

A number of published steromatching algorithms have been implemented and tested on SPOT images of areas for which gridded digital elevation models (DEMs) are available with spacings of 80 m or less, as well as ground control checkpoints. Results are presented for comparison of stereomatched output with the DEMs as well as an analysis of the errors arising and their causes. Results are discussed for planimetrically geocoded and epipolar resampled data. An error budget describing effects due to orientation, feature localisation and matching are discussed and conclusions drawn for future work in this area.  相似文献   

Reliability of Chemical Analyses of Water Samples — The Experience of the UMTRA Project     

George Rice  James Brinkman  Dianna Muller 《Ground Water Monitoring & Remediation》1988,8(3):71-75

Ground water quality investigations require reliable chemical analyses of water samples. Unfortunately, laboratory analytical results are often unreliable. The Uranium Mill Tailings Remedial Action (UMTRA) Project's solution to this problem was to establish a two-phase quality assurance program for the analysis of water samples. In the first phase, eight laboratories analyzed three solutions of known composition. The analytical accuracy of each laboratory was ranked and three laboratories were awarded contracts. The second phase consists of on-going monitoring of the reliability of the selected laboratories.
The following conclusions are based on two years of experience with the UMTRA Project's Quality Assurance Program:
• The reliability of laboratory analyses should not be taken for granted.
• Analytical reliability may be independent of the prices charged by laboratories.
• Quality assurance programs benefit both the customer and the laboratory.  相似文献   

Denitrification and Pesticide Elimination in Drinking Water Treatment with the Biodegradable Polymer Poly(ϵ‐caprolactone) (PCL)     

Angela Boley  Joris Mergaert  Claude Muller  Henning Lebrenz  Margo C. Cnockaert  Wolf‐Rüdiger Müller  Jean Swings 《洁净——土壤、空气、水》2003,31(3):195-203

A combination of denitrification and pesticide sorption with the biodegradable polymer poly(?‐caprolactone) (PCL) was examined. The function of PCL is to act as carbon source and carrier for the bacteria and simultaneously as sorbent for the pesticide endosulfan. In a short‐term examination (1 month) the addition of the pesticide endosulfan to a continuous‐flow fixed‐bed reactor resulted in an inhibition of biomass production without reduction of the denitrification performance. However in a long‐term semi‐batch reactor test (6 months) biomass production and partly denitrification rates were affected. No significant differences in microbial composition between the reactors were observed. Regardless of the type of reactor or presence of endosulfan, Acidovorax facilis was the main constituent.  相似文献   

Impacts « multi-échelle » d'un échange (Mg,Ca)–Pb et ses conséquences sur l'augmentation de la perméabilité d'une bentonite     

Nevila Jozja  Patrick Baillif  Jean-Claude Touray  Charles-Henri Pons  Fabrice Muller  Carole Burgevin 《Comptes Rendus Geoscience》2003,335(9):729-736

The article addresses the structural effects of solutions of lead nitrate on a suspended or compacted bentonite. A permeability increase is observed on compacted clay. Investigating the composition of output solution, using X-Rays Diffusion at Small Angles and Scanning Electron Microscopy, this permeability increase is explained from structural variations at nanometric (reduction of particle size) and micrometric scales (microfissuration of aggregates). To cite this article: N. Jozja et al., C. R. Geoscience 335 (2003).  相似文献   

Irregular wave generation method with given characteristics in experimental tanks     

B. Daoud  J. -M. Kobus 《Ocean Engineering》1995,22(4)

This study presents a practical method of irregular wave generation with given spectral characteristics. The method used is iterative. In order to use this method, a previous knowledge of the wave-paddle transfer function is required. The spectral analysis of the wave obtained by this method is realized by an original technique which allows the investigator to analytically obtain a smooth form of the signal spectrum from its approximated autocorrelation function by complex exponentials.  相似文献