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See detailGreen Energy and Technology
Machrafi, Hatim ULg

Book published by Bentham Science Publishers (2012)

This new book presents recent developments, state-of-the-art and progresses in the field of energy where efforts are done in order to improve the usability of energy systems, reducing their environmental ... [more ▼]

This new book presents recent developments, state-of-the-art and progresses in the field of energy where efforts are done in order to improve the usability of energy systems, reducing their environmental impact. The book aims at providing researchers, academics, engineers and advanced students information and points of discussion, a platform for future improvements in green energy. Both theoretical and applied aspects are treated in this book. Many illustrations and mathematical equations as well as practical on-the-field applications are incorporated. This book aims at contributing to the increasing interest in reducing the environmental impact of energy as well as its further development. Three parts are considered. The first part treats different energy applications and the efforts that are done in order to improve their impact on the environment. It deals with bio-energy, well-to-wheel analyses and heavy oils. Concerning bioenergy, the costs are evaluated under strict regulations imposed by a climate stabilization target, where a certain case is taken as example. The well-to-wheel energy analyses take into consideration a comprehensive study on greenhouse gases and certain criteria that concern the emissions in the case of hydrogen based fuel-cells. The second part deals with different kinds of renewable energy sources. The chapters discuss bioenergy, wind energy and solar energy. The use of biofuels is critically discussed. A real application and evaluation of wind energy is presented, by means of designing and optimalizing a wind power system. A detailed discussion about the generation of electricity by means of different kinds of solar energy is performed. The third part puts emphasis on alternative energy processes for transport utilities. In this part, is discussed, amongst others, the Homogeneous Charge Compression Ignition combustion mode. Advantages and inconveniences are proposed. Wide and comprehensive studies on this combustion mode are presented. Both a large synthesis of available work and experimental results are used in an effort to discuss these advantages and inconveniences in order to propose possible solutions. Some examples are treated elaborately. Hydrogen-based combustion is discussed and its efficiency evaluated in detail. Elaborate studies and examples give a rather complete vision of the probable use of hydrogen in internal combustion engines and the different aspects that are to be examined are treated in detail. The commercialization of fuel-cells are investigated, giving trends and possible developments that can be envisaged. Finally, a philosophy of controlling the auto-ignition in an HCCI engine is presented. This philosophy is somewhat general and the outlines can also be used for the abovementioned transportation modes. A rather general overview is given in this book, starting from different visions on reducing the impact of energy on the environment (green energy) and continuing on how this can be achieved (green technology). The different results and the available literature that is treated in various chapters in this book show that many researchers are investigating the efficient use of energy whilst looking for ways to decrease its impact on the environment. This shows the importance of such research and the work that remains to be done. [less ▲]

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See detailGreen first ! ORBi, le choix d’une politique
Thirion, Paul ULg

Conference (2012, November 16)

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See detailThe green lacewings in Belgium (Neuroptera : Chrysopidae)
Bozsik, Andras; Mignon, Jacques ULg; Gaspar, Charles

in Acta Zoologica Academiae Scientiarum Hungaricae (2002), 48(Suppl. 2), 53-59

There are merely three published sources of information on the green lacewings in Belgium. The first two were written by a Belgian and a Catalan author at the beginning of the 20th century and the third ... [more ▼]

There are merely three published sources of information on the green lacewings in Belgium. The first two were written by a Belgian and a Catalan author at the beginning of the 20th century and the third was published in 1980. Interestingly, the most recent study reported the fewest species (11), the most previous contained 12 and the second one showed 17 species, This confused situation and the paucity of data initiated the authors to identify the green lacewing collection of the Gembloux University of Agricultural Sciences, where lacewings from different parts of Belgium were preserved, and also to collect chrysopids regularly, Summarising the species reported in the literature and caught during sampling, 18 green lacewing species have been verified in Belgium: Nothochrysa fulviceps, Nothochrysa capitata, Hypochrysa elegans, Nineta flava, Nineta vittata, Nineta pallida, Chrysotropia ciliata, Chrysopa perla, Chrysopa dorsalis, Chrysopa abbreviata, Chrysopa formosa, Chrysopa phlyllochroma, Chrysopa pallens, Dichochrysa flavifrons, Dichochrysa prasina, Dichochrysa ventralis, Chrysoperla carnea, Cunctochrysa albolineata. Considering the known references, one species, Nineta pallida proved to be new for the Belgian fauna. [less ▲]

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See detailGreen leaf area decline of the last three leaves of wheat. Determination of the relationships with remote sensing green land cover.
Mackels, Christophe; Tychon, Bernard ULg

in Italian Journal of Agronomy [=IJA] = Rivista di Agronomia (2008), 3(3), 671-672

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See detailGreen leaf area decline of wheat top three leaves in Belgium and G-D of Luxembourg from 2003 to 2005 : the relationships with grain yield.
Martin, B.; El Jarroudi, Moussa ULg; Tychon, Bernard ULg

in Bibliotheca fragmenta agronomica - Book of proceedings (2006), 11(1), 167-168

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See detailGreen leaf area decline of wheat top three leaves in Belgium and G-D of Luxembourg from 2003 to 2006 : the relationships with grain yield.
Martin, B.; Tychon, Bernard ULg; El Jarroudi, Moussa ULg et al

Conference (2006, October)

The modified Gompertz model developed by Gooding et al. (2000) was used to describe the decline in green area of wheat top three leaves in field experiments where green leaf area at time t = 100*exp[-exp ... [more ▼]

The modified Gompertz model developed by Gooding et al. (2000) was used to describe the decline in green area of wheat top three leaves in field experiments where green leaf area at time t = 100*exp[-exp(-k*(t-m))]. In the absence of fungicide, green leaf area decline was associated with drought or infection with a number of foliar pathogens including Septoria tritici (sexual stage Mycospherella graminicola) and Puccinia recondita f.sp. tritici and Erysiphe graminis. On the whole experiments and cultivars there was no effect of fungicide on k but it was highly significant on m (P<0.001). When main effects are considered, fungicide delayed green leaf area decline rather than reduced its rate of progress once started. Fungicide had variable effects on grain yield, largely reflecting variation in disease infection pressures in the different years and susceptibility of the different cultivars. If no correlation was observed between k values and grain yields, m was at the contrary very closely associated with grain yields. This study supports the view of Gooding (2000) and Gaunt (1995) that, for many diseases, effects on green area duration give an adequate estimate of host yield reduction. Therefore we have use the close relationship between the parameter m of the Gompertz model and grain yield to improve the Belgium-Crop Growth Monitoring System (B-CGMS) by recalibrating LAI evolution simulated by B-CGMS according to the evolution of LAI derived from the Gompertz model. The system includes indeed a component allowing taking into account senescence in the evolution of LAI during the growing season. Recalibration has been realized through the modification of one of the parameters influencing the leaf senescence, the SPAN parameter. Modifying the SPAN parameter comes down to modify the lifespan of leaves. Considering that parasitic pressure reduces leaves lifespan and therefore the photosynthetic capacity, this approach makes it possible to take into account the influence of this pressure on yield predictions in the Belgian Crop Growth Monitoring System. [less ▲]

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See detailGreen Roofs in Cairo: A Holistic Approach for Healthy Productive Cities
Attia, Shady ULg; Mahmoud, A.

in Proceedings of 7th Annual Greening Rooftops for Sustainable Communities (2009, June)

In Cairo, the amount of green space per inhabitant is roughly equivalent to 0.33 square meters per person (3.5 square feet), one of the lowest proportions in the world. Green roofs are presented in this ... [more ▼]

In Cairo, the amount of green space per inhabitant is roughly equivalent to 0.33 square meters per person (3.5 square feet), one of the lowest proportions in the world. Green roofs are presented in this study mainly as an urban landscape for healthy and productive cities. This paper describes the idea of green roofs as platform for urban faming that is considered as a holistic approach to solve environmental, spatial, social and economic problems in large cities in the developing countries. The first part of the study, presents the theoretical framework for roof farming. Potentials and problems of green roofs are analyzed and mapped in a multilayered method. The goal is to find out what the maximum potentials of productive green rooftops and determine the best techniques for maintaining them. As a result, the research presents a set of design principles, guidelines and tools that can assist in transforming existing roofs into productive roof farms. The second part of the study examines successful case studies in Cairo, including schools and residential units and introduces a broader function of roof gardens, as well as the barriers for successful implementation. The final result, point to the importance of considering green roofs as creative development opportunity for urban open spaces, responsive support for bio and food security, in addition to the climatic, environmental and aesthetical benefits. Finally, the paper presents the more interesting results and explains why this approach is successful and how the results can be extended to other cities. [less ▲]

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See detailGreen synthesis and antioxidant activity of new PEGylated ferulic acids
Nicks, Francois ULg; Richel, Aurore ULg; Richard, Gaetan ULg et al

in Tetrahedron Letters (2012), 53(19), 2402-2405

PEGylation of ferulic acid is described through a green esterification process involving poly(ethylene glycol) (PEG) with three different average molecular weights (200, 400 and 1000 g/mol) as both ... [more ▼]

PEGylation of ferulic acid is described through a green esterification process involving poly(ethylene glycol) (PEG) with three different average molecular weights (200, 400 and 1000 g/mol) as both reactive and solvent. Esterification with PEG400 and PEG1000 leads to original compounds soluble in all proportions in water. These new compounds display an antioxidant activity similar to that of ferulic acid. [less ▲]

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See detailGreening the Common Agricultural Policy (CAP). The Analysis of Developments
Habran, Maxime ULg

in Punctul Critic, Quarterly social, political and cultural diagnostic (2012), 6

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See detailGreenland [in "State of the Climate in 2008"]
Box, J.; Bai, L.; Benson, R. et al

in Bulletin of the American Meteorological Society (BAMS) (2009), 90

An abnormally cold winter across the southern half of Greenland led to substantially higher west coast sea ice thickness and concentration. Even so, record-setting summer temperatures around Greenland ... [more ▼]

An abnormally cold winter across the southern half of Greenland led to substantially higher west coast sea ice thickness and concentration. Even so, record-setting summer temperatures around Greenland, combined with an intense melt season (particularly across the northern ice sheet), led the 2008 Greenland climate to be marked by continued ice sheet mass deficit and floating ice disintegration. [less ▲]

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See detailGreenland [in "State of the Climate in 2009"]
Box, J.; Bhattacharya, I.; Cappelen, J. et al

in Bulletin of the American Meteorological Society [= BAMS] (2010), 91(6), 121-124

The summer minimum ice extent in the Arctic was the third-lowest recorded since 1979. The 2008/09 boreal snow cover season marked a continuation of relatively shorter snow seasons, due primarily to an ... [more ▼]

The summer minimum ice extent in the Arctic was the third-lowest recorded since 1979. The 2008/09 boreal snow cover season marked a continuation of relatively shorter snow seasons, due primarily to an early disappearance of snow cover in spring. Preliminary data indicate a high probability that 2009 will be the 19th consecutive year that glaciers have lost mass. Below normal precipitation led the 34 widest marine terminating glaciers in Greenland to lose 101 km2 ice area in 2009, within an annual loss rate of 106 km2 over the past decade. Observations show a general increase in permafrost temperatures during the last several decades in Alaska, northwest Canada, Siberia, and Northern Europe. Changes in the timing of tundra green-up and senescence are also occurring, with earlier green-up in the High Arctic and a shift to a longer green season in fall in the Low Arctic. [less ▲]

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See detailGreenland [in "State of the Climate in 2010"]
Box, J. E.; Ahlstrøm, A.; Cappelen, J. et al

in Bulletin of the American Meteorological Society [= BAMS] (2011), 92(6), 161-171

Record warm air temperatures were observed over Greenland in 2010. This included the warmest year on record for Greenland's capital, Nuuk, in at least 138 years. The duration of the melt period on ... [more ▼]

Record warm air temperatures were observed over Greenland in 2010. This included the warmest year on record for Greenland's capital, Nuuk, in at least 138 years. The duration of the melt period on Greenland’s inland ice sheet was exceptional, being 1 month longer than the average over the past 30 years, and led to an extended period of amplified summer melt. All of the additional melt water very likely contributing to a faster rate of crevasse widening. Glacier loss along the Greenland margins was also exceptional in 2010, with the largest single glacier area loss (110 square miles, at Petermann glacier) equivalent to an area four times that of Manhattan Island. There is now no doubt that Greenland ice losses have not just increased above past decades, but have accelerated. The implication is that sea level rise projections will again need to be revised upward. [less ▲]

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See detailGreenland [in Arctic Report Card 2010]
Box, J.; Cappelen, J.; Decker, D. et al

Report (2010)

Record warm air temperatures were observed over Greenland in 2010. This included the warmest year on record for Greenland's capital, Nuuk, in at least 138 years. The duration of the melt period on ... [more ▼]

Record warm air temperatures were observed over Greenland in 2010. This included the warmest year on record for Greenland's capital, Nuuk, in at least 138 years. The duration of the melt period on Greenland’s inland ice sheet was exceptional, being 1 month longer than the average over the past 30 years, and led to an extended period of amplified summer melt. All of the additional melt water very likely contributing to a faster rate of crevasse widening. Glacier loss along the Greenland margins was also exceptional in 2010, with the largest single glacier area loss (110 square miles, at Petermann glacier) equivalent to an area four times that of Manhattan Island. There is now no doubt that Greenland ice losses have not just increased above past decades, but have accelerated. The implication is that sea level rise projections will again need to be revised upward. [less ▲]

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See detailGreenland climate change: from the past to the future
Masson‐Delmotte, Valérie; Swingedouw, Didier; Landais, Amaëlle et al

in Wiley Interdisciplinary Reviews. RNA (2012), 3(5), 427-449

Climate archives available from deep sea and marine shelf sediments, glaciers, lakes, and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics ... [more ▼]

Climate archives available from deep sea and marine shelf sediments, glaciers, lakes, and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics, and land surface changes in a broader perspective. We show that, during the last decade (2000s), atmospheric and sea surface temperatures are reaching levels last encountered millennia ago, when northern high latitude summer insolation was higher due to a different orbital configuration. Records from lake sediments in southern Greenland document major environmental and climatic conditions during the last 10,000 years, highlighting the role of soil dynamics in past vegetation changes, and stressing the growing anthropogenic impacts on soil erosion during the recent decades. Furthermore, past and present changes in atmospheric and oceanic heat advection appear to strongly influence both regional climate and ice sheet dynamics. Projections from climate models are investigated to quantify the magnitude and rates of future changes in Greenland temperature, which may be faster than past abrupt events occurring under interglacial conditions. Within one century, in response to increasing greenhouse gas emissions, Greenland may reach temperatures last time encountered during the last interglacial period, approximately 125,000 years ago. We review and discuss whether analogies between the last interglacial and future changes are reasonable, because of the different seasonal impacts of orbital and greenhouse gas forcings. Over several decades to centuries, future Greenland melt may act as a negative feedback, limiting regional warming albeit with global sea level and climatic impacts. [less ▲]

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See detailGreenland Ice Sheet - Arctic Report Card: Update for 2011
Box, J.; Cappelen, J.; Chen, C. et al

Report (2011)

A persistent and strong negative North Atlantic Oscillation (NAO) index was responsible for southerly air flow along the west of Greenland, which caused anomalously warm weather in winter 2010-11 and ... [more ▼]

A persistent and strong negative North Atlantic Oscillation (NAO) index was responsible for southerly air flow along the west of Greenland, which caused anomalously warm weather in winter 2010-11 and summer 2011. The area and duration of melting at the surface of the ice sheet in summer 2011 were the third highest since 1979. The lowest surface albedo observed in 12 years of satellite observations (2000-2011) was a consequence of enhanced surface melting and below normal summer snowfall. The area of marine-terminating glaciers continued to decrease, though at less than half the rate of the previous 10 years. In situ measurements revealed near record-setting mass losses concentrated at higher elevations on the western slope of the ice sheet, and at an isolated glacier in southeastern Greenland. Total ice sheet mass loss in 2011 was 70% larger than the 2003-09 average annual loss rate of -250 Gt y-1. According to satellite gravity data obtained since 2002, ice sheet mass loss is accelerating. [less ▲]

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See detailGreenland Ice Sheet [in Arctic Report Card 2012]
Box, J.; Cappelen, J.; Chen, C. et al

Report (2013)

- The duration of melting at the surface of the ice sheet in summer 2012 was the longest since satellite observations began in 1979, and a rare, near-ice sheet-wide surface melt event was recorded by ... [more ▼]

- The duration of melting at the surface of the ice sheet in summer 2012 was the longest since satellite observations began in 1979, and a rare, near-ice sheet-wide surface melt event was recorded by satellites for the first time. - The lowest surface albedo observed in 13 years of satellite observations (2000-2012) was a consequence of a persistent and compounding feedback of enhanced surface melting and below normal summer snowfall. - Field measurements along a transect (the K-Transect) on the western slope of the ice sheet revealed record-setting mass losses at high elevations. - A persistent and strong negative North Atlantic Oscillation (NAO) index caused southerly air flow into western Greenland, anomalously warm weather and the spatially and temporally extensive melting, low albedo and mass losses observed in summer 2012. [less ▲]

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See detailGreenland ice sheet albedo feedback: thermodynamics and atmospheric drivers
Box, J.; Fettweis, Xavier ULg; Stroeve, J. et al

in Cryosphere (The) (2012), 6

In this study, snowpack scenarios are modelled across the French Alps using dynamically downscaled variables from the ALADIN Regional Climate Model (RCM) for the control period (1961–1990) and three ... [more ▼]

In this study, snowpack scenarios are modelled across the French Alps using dynamically downscaled variables from the ALADIN Regional Climate Model (RCM) for the control period (1961–1990) and three emission scenarios (SRES B1, A1B and A2) for the mid- and late 21st century (2021–2050 and 2071–2100). These variables are statistically adapted to the different elevations, aspects and slopes of the Alpine massifs. For this purpose, we use a simple analogue criterion with ERA40 series as well as an existing detailed climatology of the French Alps (Durand et al., 2009a) that provides complete meteorological fields from the SAFRAN analysis model. The resulting scenarios of precipitation, temperature, wind, cloudiness, longwave and shortwave radiation, and humidity are used to run the physical snow model CROCUS and simulate snowpack evolution over the massifs studied. The seasonal and regional characteristics of the simulated climate and snow cover changes are explored, as is the influence of the scenarios on these changes. Preliminary results suggest that the snow water equivalent (SWE) of the snowpack will decrease dramatically in the next century, especially in the Southern and Extreme Southern parts of the Alps. This decrease seems to result primarily from a general warming throughout the year, and possibly a deficit of precipitation in the autumn. The magnitude of the snow cover decline follows a marked altitudinal gradient, with the highest altitudes being less exposed to climate change. Scenario A2, with its high concentrations of greenhouse gases, results in a SWE reduction roughly twice as large as in the low-emission scenario B1 by the end of the century. This study needs to be completed using simulations from other RCMs, since a multi-model approach is essential for uncertainty analysis. [less ▲]

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See detailGreenland ice sheet melt: intercomparison between SSM/I and a regional climate model
Fettweis, Xavier ULg

Conference (2004, April 27)

The daily melt extent on the Greenland ice sheet can easily be retrieved from satellite observations and therefore is a very useful index to study the surface mass balance (SMB) evolution of the last ... [more ▼]

The daily melt extent on the Greenland ice sheet can easily be retrieved from satellite observations and therefore is a very useful index to study the surface mass balance (SMB) evolution of the last years. It is also particularly helpful for the validation of a model because there is little in-situ observations on the Greenland ice sheet. The remote sensing melt-detection algorithms use the changes in microwave brightness temperatures during snowmelt. The most used one on Greenland is the cross-polarized gradient ratio (XPGR) method from Abdalati and Steffen (1997)*. It was found from a comparison with simulations made by the regional climate model MAR (Modèle Atmosphérique Régional) that the rainfall on the ice sheet in summer perturbs the melt signal detected by XPGR via the 37-Ghz vertical channel. An improved XPGR algorithm was developed. We present here our motivation to modify the XPGR. An intercomparaison between the SSM/I derived observations and the MAR is performed. The aim is to validate our model, in order to study the SMB for future climate. The simulated extent and time evolution of the wet snow zone compares better with satellite derived data when the modified XPGR method is used. [less ▲]

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