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- Garcia-Rojas, L. M., et al.
(author)
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Rendimiento de los productos de la descomposición térmica De la madera de eucalyptus saligna smith a diferentes alturas del fuste comercial
- 2009
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In: Revista Chapingo, Serie Ciencias Forestales y del Ambiente. - 0186-3231. ; 15:2, s. 147-154
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Journal article (peer-reviewed)abstract
- In this work the qualitative and quantitative results of the thermal pyrolysis of Eucalyptus Saligna Smith is presented, to different heights of the commercial wooden log. The wood was collected from Pinar del Rio, Cuba. The need to use this wood like energy source in the region led to the research at laboratory scale. The used trees were 20 and 22 years old, from which 20 cm disks were cut at 25; 55 and 85 % height of the log, milled to chips and air dried. The chemical composition was determined and was carried out the previous analysis of the samples, as well as the thermal decomposition in micro scale. The study of products from the pyrolysis (coal and tar), it was made in a reactor of fixed channel. The caloric value of the biomass and its charcoal was determined. The influence of the height of the log in the product yields from the pyrolysis was studied.As significant differences was observed as for the chemical composition of the studied wood: cellulose, hemicelulose and lignine, being observed an apparent increase of the lignine percentage with the height of the tree. The previous analysis belongs together with the chemical composition of the studied biomass. A small decrease was observed in the yield of the coal and of the percentage of tars with the height of the tree, this belongs together with the variation of the chemical composition according to the height of the tree. The biggest yield of coal and caloric value was achieved at the lowest height of the tree. The contribution to gas goes increasing with the height.
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| 3. |
- Kassler, Andreas, et al.
(author)
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Supporting Multicast in Ad-Hoc networks in a Hotspot Context
- 2005
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Conference paper (peer-reviewed)abstract
- This paper discusses the usage of Ad-Hoc technologies as hotspot extension mechanisms. We propose a hybrid network where 802.16 links are used for providing high-bandwidth access, and local distribution is performed by Ad-Hoc network nodes (based on 802.11 technologies), thus covering arbitrary areas around the 802.16 stations, which might be connected to the Internet. We evaluate the performance of the system and its efficiency in providing QoS in multicast connections. For providing multicasting services, we propose two extensions of the ODMRP and MAODV routing algorithms by augmenting them with a zone routing behavior, thus producing two new hybrid multicast routing algorithms, named ZODMRP and ZMAODV. The simulation results show that ZODMRP provides the highest packet delivery ratio and lowest delay without introducing large overhead, being then able to provide predictable QoS for packet delivery in multicast sessions
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| 4. |
- Sugiharto, A. B., et al.
(author)
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Generation and application of high power femtosecond pulses in the vibrational fingerprint region
- 2008
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In: Applied physics. B, Lasers and optics (Print). - : Springer Science and Business Media LLC. - 0946-2171 .- 1432-0649. ; 91:2, s. 315-318
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Journal article (peer-reviewed)abstract
- We present a novel high power femtosecond infrared laser source, based on a three-stage chirped-pulse amplification scheme. Owing to the high power output of the Ti:sapphire amplifiers, it becomes routinely possible to produce femtosecond infrared laser pulses in the wavelength region of 2.6-20 mu m with minimum pulse energies of 15 mu J, to our knowledge roughly an improvement of an order of magnitude. With such pulses we have performed femtosecond second-order nonlinear optical surface spectroscopy in the fingerprint region. We have probed the skeletal modes of the first few monolayers of a polymer/air interface in a femtosecond vibrational sum frequency generation experiment. This development opens up new possibilities to investigate surface structures and dynamics of, e.g., organo-metallic compounds, proteins, and peptides.
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