1,530 research outputs found
Carbon storage and sequestration potential of selected tree species in India
No full textCO2FIX, Eucalyptus, Teak, Poplar, Sal, Forest simulation model, Thinning, Rotation length,
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Early Buddhist architecture of Bengal: morphological study on the vihāra of c. 3rd to 8th centuries
No full textThis dissertation examines the evolution of early Buddhist architectural forms of Bengal, specifically its vihāra and shrine structures. In general, this research explores Gupta and post-Gupta (c. third to eighth centuries AD) vihāra architecture of Bengal, where the primary focus is on the Buddhist shrine architecture constructed during this period. There is a preconception amongst historians that the period between the Gupta and the Pāla periods was characterized by disorder and chaos, commonly known as the period of Matsyanyayam. This is the reason why discussions on the architectural history of Bengal have generally commenced from the Pāla period (c. 750 AD onwards). Analyzing extant and new evidences this study argues that the Buddhist architecture of Bengal thrived during the intervening period, albeit under the patronage of local kings and rulers. In the field of art and sculpture it is accepted that Buddhist Pāla art was a continuation of previous Gupta art forms, where post-Gupta period acted as the transition or a bridge. Following this general pattern, as this thesis argues, the rectangular Gupta shrine plan takes a mature cruciform shape during the Pāla period through a complex morphological development. The nature of Buddhist shrine architecture in Bengal during the early Gupta, later Gupta, and post-Gupta periods is described in the light of analyzed archaeological findings and architectural trends
Effects of the pyrethroid insecticide gamma-cyhalothrin on aquatic invertebrates in laboratory and outdoor microcosm tests
No full textThe sensitivity of a range of freshwater lentic invertebrates to gamma-cyhalothrin (GCH), a single enantiomer of the synthetic pyrethroid lambda-cyhalothrin, was assessed in single species laboratory tests and an outdoor multi-species ecosystem test. The most sensitive species in the laboratory single species tests with GCH was Chaoborus obscuripes (96 h EC50: 3.8 ng/l). The species sensitivity distribution curve, based on the laboratory 96 h EC50 acute toxicity data for eight species, gave a median HC5 value for GCH of 2.12 ng/l. The NOECcommunity derived from the multi-species ecosystem test was 5 ng/l, and the insects Chaoborus sp. and Caenis sp. were identified as the most sensitive species. The results indicate that the median HC5, based on eight species selected to include those known to be sensitive to pyrethroids, provided a good estimation of the NOECcommunity for GCH. Furthermore, the results for GCH indicated that the endpoints typically used in higher-tier risk assessments for pesticides in Europe (HC5 and NOECcommunity) were consistent with expectations when compared to the equivalent endpoints for the racemate LC
Molecular evidence supports simultaneous association of the achlorophyllous orchid Chamaegastrodia inverta with ectomycorrhizal Ceratobasidiaceae and Russulaceae
No full textBackground: Achlorophyllous orchids are mycoheterotrophic plants, which lack photosynthetic ability and associate with fungi to acquire carbon from different environmental sources. In tropical latitudes, achlorophyllous forest orchids show a preference to establish mycorrhizal relationships with saprotrophic fungi. However, a few of them have been recently found to associate with ectomycorrhizal fungi and there is still much to be learned about the identity of fungi associated with tropical orchids. The present study focused on mycorrhizal diversity in the achlorophyllous orchid C. inverta, an endangered species, which is endemic to southern China. The aim of this work was to identify the main mycorrhizal partners of C. inverta in different plant life stages, by means of morphological and molecular methods. Results: Microscopy showed that the roots of analysed C. inverta samples were extensively colonized by fungal hyphae forming pelotons in root cortical cells. Fungal ITS regions were amplified by polymerase chain reaction, from DNA extracted from fungal mycelia isolated from orchid root samples, as well as from total root DNA. Molecular sequencing and phylogenetic analyses showed that the investigated orchid primarily associated with ectomycorrhizal fungi belonging to a narrow clade within the family Ceratobasidiaceae, which was previously detected in a few fully mycoheterotrophic orchids and was also found to show ectomycorrhizal capability on trees and shrubs. Russulaceae fungal symbionts, showing high similarity with members of the ectomycorrhizal genus Russula, were also identified from the roots of C. inverta, at young seedling stage. Ascomycetous fungi including
Chaetomium, Diaporthe, Leptodontidium, and Phomopsis genera, and zygomycetes in the genus Mortierella were
obtained from orchid root isolated strains with unclear functional role. This study represents the first assessment of root fungal diversity in the rare, cryptic and narrowly distributed Chinese orchid C. inverta. Our results provide new insights on the spectrum of orchid-fungus symbiosis suggesting an unprecedented mixed association between the studied achlorophyllous forest orchid and ectomycorrhizal fungi belonging to Ceratobasidiaceae and Russulaceae. Ceratobasidioid fungi as dominant associates in the roots of C. inverta represent a new record of the rare association between the identified fungal group and fully mycoheterotrophic orchids in nature
Traffic monitoring using handheld GSM phones. Part B: Simulation study
No full textRevised version of LVV rapport, VK 2001.004. This report contains the description of a novel map-matching algorithm, and the results of a simulation study into the feasibility of traffic monitoring using handheld mobile phones.Transport & PlanningCivil Engineering and Geoscience
Modelling of VK column reactors for manufacturing nylon-6
No full text117-127<span style="font-size:11.0pt;line-height:115%;
font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:calibri;mso-bidi-theme-font:minor-latin;="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">A
stagewise model based on tanks in series approach has been proposed to
elucidate the effects of backmixing in the two-phase zone of VK (Vereinfacht
Kontinuerlich) column reactors. A recycle stream between tanks has been used to
represent backmixing due to the vapour stream rising counter currently to the
liquid stream. The model has been used to calculate the monomer conversion,
number average degree of polymerization and the polydispersity index at the end
of the reactor. It has been found that increased backmixing increases the water
holding capacity of the stream and, therefore, increases the conversion at the
end of the two-phase zone. As water also lowers the degree of polymerization,
it has been found that at the end of the reactor where equilibrium is reached,
the degree of polymerization decreases with increased backmixing in the top
portion of the reactor. The polydispersity index remains relatively unaffected
as equilibrium is attained at the end of the reactor. H too high temperatures
are used at the beginning of the reactor, the streams would contain less water
and this would lead to higher degrees of polymerization but to lower rates.</span
Microbial glycoside hydrolases for biomass utilization in biofuels application
No full textRenewable biomass is predicted to have the potential to meet at least a quarter of the world demand for transportation fuel, but to do so both terrestrial lignocellulosic as well as marine algal resources need to be efficiently utilized. In the processes where these biomasses are converted to different types of energy-carriers (for example fuel alcohols e.g. ethanol or butanol) microbial glycoside hydrolases have a role in the saccharification process. During saccharification polymeric carbohydrate resources (e.g. starch, cellulose or hemicellulose) are hydrolysed into mono and oligosaccharides that can be utilized by the organism selected to ferment these carbohydrates into the desired energy-carrier. This chapter aims to shed light on different processing alternatives for the conversion of lignocellulose or algal starch into mono or oligosaccharides, and what roles the microbial glycoside hydrolases have as processing aids in these conversions
Geomorphologic approach to synthesis of direct runoff hydrograph from the Upper Tiber River basin, Italy
No full textThe effective rainfall-direct runoff relationship was investigated for forty events on tour large basins by using a geomorphologic representation of the instantaneous unit hydrograph (IUH) proposed by Gupta et al. (1980). These basins are a part of the Upper Tiber River basin located in Central Italy and range in area from 934 km2 to 4,147 km2. For each event the volume of direct runoff was obtained by hydrograph separation. The effective rainfall hyetograph was then determined by using the two-term Philip infiltration equation in conjunction with a volume balance analysis. The geomorphologic parameters required by the IUH were extracted from a topographic map of each basin with the map scale of 1:200,000. It was found that the dimensionless form of the IUH remained practically Constant from one basin to another. By convoluting the geomorphologic IUH, derived for each basin, with the effective rainfall, the direct runoff hydrograph was synthesized for each event. The model results compare reasonably well with observations of each basin. The maximum and mean errors in computing peak flow were 33% and 15% respectively. Furthermore, the magnitudes of these errors did not depend upon the basin area. A sensitivity analysis of the model structure revealed that its order of geomorphologic representation could be reduced by at least one without a significant loss of accuracy. This small reduction in order amounted to a considerable reduction in geomorphologic complexity and computational effort. The model results were quite sensitive to basin lag and sorptivity parameter of the infiltration equation. A 10% variation in basin lag resulted in approximately 10% variation of computed peak discharge. However, a 10% variation in sorptivity produced an approximately 20% mean variation in computed peak discharge
Micropropagation and in vitro culture of Pyrethrum [Chrysanthemum cinerariifolium (Trev.) Vis.]
No full textPyrethrum (Chrysanthemum cinerariifolium (Trev.) Vis. = Tanacetum cineariaefolium (Trev.) Schultz-Bip.) is a perennial herbaceous plant belonging to the family Asteraceae, native to Albania and the area of former Yugoslavia. It is the only species in the genus Tanacetum having an agronomic importance, although the genus consists of several species producing similar types of bioactive metabolites. The species is grown in order to obtain the insecticidal compounds collectively termed pyrethrins, which are found primarily in the flower heads.
In this work we discuss the results found from a worldwide literature review about the micropropagation techniques followed on Pyrethrum, the in vitro culture conditions, and the ex vitro establishment trials under Mediterranean environmental conditions. Many technical problems concerning the propagation of the species seem to have been solved, and detailed protocols are available for an easy and fast propagation by seeds, vegetative splits, stem cuttings (rooted under mist or not), and tissue culture. The first attempts to introduce its cultivation into the semi-arid Mediterranean environments have brought to satisfactory results, and the species may be suggested as a valuable opportunity for the development strategies in new Mediterranean farming systems
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