Nanosecond channel-switching exact optical frequency synthesizer using an optical injection phase-locked loop (OIPLL)

Experimental results are reported on an optical frequency synthesizer for use in dynamic dense wavelength-division-multiplexing networks, based on a tuneable laser in an optical injection phase-locked loop for rapid wavelength locking. The source combines high stability (50 dB), narrow linewidth (10 MHz), and fast wavelength switching (<10 ns)

Calvyn oor die verskynsel van demonologie

Scripture teaches an increased occurrence of demonology at the end of time (cf. 1 Tim. 4:1; Rev. 16:13, 14). This truth can already be observed in increasing occultism, witchcraft and other forms of demonology in Europe and in Africa, where traditional African culture plays a decisive role. In order to combat demonology from a Reformed point of view, it is important to note John Calvin’s opinion and approach. Not only was he one of the greatest Reformed theologians, but he also lived and worked in the “devil’s golden age”. Calvin’s hermeneutical principles and his interpretation of Scripture are still essentially important

Modeling magnetic nanopolymer flow with induction and nanoparticle solid volume fraction effects : solar magnetic nanopolymer fabrication simulation

A mathematical model is presented for the nonlinear steady, forced convection, hydromagnetic flow of electro-conductive magnetic nano-polymer with magnetic induction effects included. The transformed two-parameter, non-dimensional governing partial differential equations for mass, momentum, magnetic induction and heat conservation are solved with the local non-similarity method (LNM) subject to appropriate boundary conditions. Keller’s implicit finite difference “box” method (KBM) is used to validate solutions. Computations for four different nanoparticles and three different base fluids are included. Silver nanoparticles in combination with various base fluids enhance temperatures and induced magnetic field and accelerate the flow. An elevation in magnetic body force number decelerates the flow whereas an increase in magnetic Prandtl number elevates the magnetic induction. Furthermore, increasing nanoparticle solid volume fraction is found to substantially boost temperatures. Applications of the study arise in advanced magnetic solar nano-materials (fluids) processing technologies

Contribution à la régulation de la température au sein d’un digesteur de type batch utilisant un système de chauffage de type solaire

Ce travail s’est penché sur la régulation de la température dans un digesteur de type batch alimenté thermiquement par un système solaire, dans le but de réduire le temps de production de biogaz et ainsi d’augmenter le volume du biogaz produit et la quantité de déchets traitée. Ce digesteur a été modélisé avec le modèle AM2 qui a été implémenté dans le logiciel LabVIEW. Pour utiliser la température comme entrée de ce modèle, nous avons remplacé dans la formule de croissance bactérienne de Monod, le taux de croissance maximal par la formule de croissance bactérienne de Ratkowsky qui est en fonction de la température. On a ensuite ajouté le modèle de la variation de la température dans le digesteur. Les résultats ont montré que le temps de séjour des matières organiques dans le digesteur est bien réduit en comparaison avec celui obtenu dans le cas du modèle sans la régulation. Le processus de la dégradation a donc bien été accéléré.Mots-clés: digestion anaérobie, modélisation du digesteur, régulation de la température. Contribution to the control of temperature in a batch digestor fed thermically by a solar systemThis work considered the temperature control in a digester of the batch type fed thermically by a solar system, with an aim of reducing the time of production of biogas and thus of increasing the volume of produced biogas. To model this digester we chose the model AM2 to which one added the model of the variation in the temperature in the digester. The results of simulations showed that the residence time of the organic matter in the digester is well reduced in comparison with that obtained in the case of the model without the regulation. The process of degradation was thus indeed accelerated.Keywords: anaerobic digestion, modeling of the digester, temperature control

Alternative uses of sorghum and pearl millet in Asia: proceedings of the Expert Meeting, ICRISAT, Patancheru, Andhra Pradesh, India, 1-4 July 2003

Both sorghum and pearl millet are staple food crops for the poor people in the semi-arid tropics (SAT). However, during the last two decades both crops are becoming less important as staple foods in SAT countries. Demand for coarse cereals (such as sorghum and pearl millet) as human food is decreasing in many countries, due to increased production and availability of preferred cereals (such as rice and wheat) at subsidized prices. The poor farmers in rainfed SAT cannot grow other crops, and are economically impacted negatively, as they do not get reasonable price for their produce. However, possibilities of alternative uses of sorghum and pearl millet are creating new opportunities that have potential to increase market demand and income to farmers. An Expert Meeting on "Alternative Uses of Sorghum and Pearl Millet in Asia" was organized to: (i) synthesize the available information and assess the future outlook for increasing the demand and expanding market opportunities for alternative uses of sorghum and pearl millet wi t h special reference to alternative novel food products, livestock feed, starch and brewing/distilling industries; (ii) assess existing and improved sorghum and pearl millet cultivars for suitability of alternative uses mentioned above; and (iii) identify potential players and opportunities for stimulating the institutional alliances among public, private, industry and NGO sectors to enhance alternative uses and market demand. Sixty participants from China, India, Indonesia, Pakistan, Thailand, USA and ICRISAT discussed the various aspects (mentioned above) to enhance the utilization of sorghum and pearl millet that would lead to sustained market demand for these crops. This, in turn, would ensure increased income and better livelihoods for the resource-poor sorghum and pearl millet farmers in the SAT countries. The proceedings document the 22 papers presented at the expert meeting to serve as a valuable reference book on alternative uses of sorghum and pearl millet

Alternative uses of sorghum and pearl millet in Asia: proceedings of the Expert Meeting

Both sorghum and pearl millet are staple food crops for the poor people in the semi-arid tropics (SAT). However, during the last two decades both crops are becoming less important as staple foods in SAT countries. Demand for coarse cereals (such as sorghum and pearl millet) as human food is decreasing in many countries, due to increased production and availability of preferred cereals (such as rice and wheat) at subsidized prices. The poor farmers in rainfed SAT cannot grow other crops, and are economically impacted negatively, as they do not get reasonable price for their produce. However, possibilities of alternative uses of sorghum and pearl millet are creating new opportunities that have potential to increase market demand and income to farmers. An Expert Meeting on "Alternative Uses of Sorghum and Pearl Millet in Asia" was organized to: (i) synthesize the available information and assess the future outlook for increasing the demand and expanding market opportunities for alternative uses of sorghum and pearl millet wi t h special reference to alternative novel food products, livestock feed, starch and brewing/distilling industries; (ii) assess existing and improved sorghum and pearl millet cultivars for suitability of alternative uses mentioned above; and (iii) identify potential players and opportunities for stimulating the institutional alliances among public, private, industry and NGO sectors to enhance alternative uses and market demand. Sixty participants from China, India, Indonesia, Pakistan, Thailand, USA and ICRISAT discussed the various aspects (mentioned above) to enhance the utilization of sorghum and pearl millet that would lead to sustained market demand for these crops. This, in turn, would ensure increased income and better livelihoods for the resource-poor sorghum and pearl millet farmers in the SAT countries. The proceedings document the 22 papers presented at the expert meeting to serve as a valuable reference book on alternative uses of sorghum and pearl millet

Production of a rhamnolipid-type biosurfactant by Pseudomonas aeruginosa LBM10 grown on glycerol

The work herewith investigated the effect of the culture medium composition on rhamnolipid production by Pseudomonas aeruginosa LBM10, previously isolated from an estuarine environment in Southern Brazil. Experimental design and surface response methodology were used in order to improve biosurfactant production using glycerol, a renewable carbon source. The assays were carried out in a rotary shaker at 30°C and 180 rpm for 120 h and the parameters studied were glycerol concentration, C/N (carbon/nitrogen) and C/P (carbon/phosphorus) ratios. Low glycerol concentration and a phosphorus-limiting condition were favorable for rhamnolipid production. Contour plots constructed by predictive polynomial equations led to a glycerol concentration of 13.2 g/l, a C/N ratio of 12.8 and a C/P ratio of 40 in order to maximize rhamnolipid concentration (4.15 g/l) associated with a high emulsification index (61%).Keywords: Biosurfactant, surface-active compounds, experimental design, phosphorus limitatio

Pre-screening of filamentous fungi isolated from a contaminated site in Southern Brazil for bioaugmentation purposes

Four Aspergillus sp. strains were isolated from contaminated soil in Rio Grande, Southern Brazil. The biodegradation potential of these strains was evaluated using a simple method involving the determination of colony growth rates on plates containing a specific hydrocarbon or petroleumderivative as the only carbon source. The LEBM1 strain presented a high tolerance level to BTX. It was the only strain capable of growth on all the media, with growth rates varying from 1.3 to 2.2 mm/day. The LEBM2 strain presented the potential for phenol degradation, while the LEBM3 strain could be used for gasoline, diesel oil, hexane and chlorobenzene

Solidarities at a distance: extending Fairtrade gold to East Africa

This article examines how Fairtrade is transforming artisanal and small-scale gold mining. Focusing on the “Extending Fairtrade Gold to Africa” project in East Africa, it demonstrates how Fairtrade is becoming embedded within local formalization contexts and organizational dynamics. The Project is at an early stage; therefore, findings consider emerging issues. By probing what solidarities at a distance imply for gold mining, the article elaborates on how artisanal and small-scale miner organisations are developing to produce gold for Fairtrade markets. Whilst recognising that Fairtrade is not targeting the most marginalised, unlicensed miners, those groups incorporated into Fairtrade are heterogeneous and have significant development needs. With the ‘unfinished business’ of certification and supply of Fairtrade gold to international markets only starting to be realised, time is needed to tell whether an equitable distribution of benefits from Fairtrade will be realised amongst miners and within mining communities

Exact, agile, optical frequency synthesis using an optical comb generator and optical injection phase lock loop

A novel optical source for use in agile dense wavelength division multiplexing (DWDM) networks is described. This source combines reference limited stability, wide tuning range, high spectral purity, narrow line width and fast wavelength switching