276 research outputs found
Thermography for Performance Optimisation of Spark-ignition Engine due to Soot Formation in Exhaust Pipe
The usage of thermography as an effective condition monitoring tool for performance evaluation on spark-ignition engine has been discussed. The technique allows for the monitoring of temperatures and thermal patterns while the equipment are running under loaded condition. The experiments have been conducted on petrol engine to acquire thermographs of the exhaust pipe under different loads with different diameters of the exhaust pipe to provide condition for soot formation. The heat transfer analysis was carried out using properties of CO2 for three different flow areas by inserting metallic tubes of known thickness in the exhaust pipe. The paper emphasises that soot formation will reduce the flow area which will result in increase in the surface temperature and the thickness of soot layer can be further correlated with the running performance of the engine.Defence Science Journal, 2011, 61(1), pp.12-18, DOI:http://dx.doi.org/10.14429/dsj.61.16
Remote Raman Spectroscopy of Minerals at Elevated Temperature Relevant to Venus Exploration
We have used a remote time-resolved telescopic Raman system equipped with 532 nm pulsed laser excitation and a gated intensified CCD (ICCD) detector for measuring Raman spectra of a number of minerals at high temperature to 970 K. Remote Raman measurements were made with samples at 9-meter in side a high-temperature furnace by gating the ICCD detector with 2 micro-sec gate to minimize interference from blackbody emission from mineral surfaces at high temperature as well as interference from ambient light. A comparison of Raman spectra of gypsum (CaSO4.2H2O), dolomite (CaMg(CO3)2), and olivine (Mg2Fe2-xSiO4), as a function of temperature shows that the Raman lines remains sharp and well defined even in the high-temperature spectra. In the case of gypsum, Raman spectral fingerprints of CaSO4.H2O at 518 K were observed due to dehydration of gypsum. In the case of dolomite, partial mineral dissociation was observed at 973 K at ambient pressure indicating that some of the dolomite might survive on Venus surface that is at approximately 750 K and 92 atmospheric pressure. Time-resolved Raman spectra of low clino-enstatite (MgSiO3) measured at 75 mm from the sample in side the high-temperature furnace also show that the Raman lines remains sharp and well defined in the high temperature spectra. These high-temperature remote Raman spectra of minerals show that time-resolved Raman spectroscopy can be used as a potential tool for exploring Venus surface mineralogy at shorter (75 mm) and long (9 m) distances from the samples both during daytime and nighttime. The remote Raman system could also be used for measuring profiles of molecular species in the dense Venus atmosphere during descent as well as on the surface
Efficient adaptive switch design for charge pumps in micro-scale energy harvesting
The performance of Micro-scale energy harvesting unit depends on the efficient design of charge-pump. Optimization of the dimension of MOSFET switches in charge pump is one of the techniques to improve the efficiency. In this work, a new optimization technique for transistor sizing and a concept of reconfigurable adaptive switches has been introduced to maximize the extracted power. A control unit is designed for adaptive reconfiguration of the switches. These proposed techniques are validated for linear charge-pump topology in UMC 180nm technology. Combined effect of size optimization of switch along with reconfigurable switch offers an improvement up to 23.5% in the net harvested power with 6% less silicon area
Filamentous Soil Fungi from Ny-Ålesund, Spitsbergen, and Screening for Extracellular Enzymes
Soil filamentous fungi from Ny-Ålesund, Spitsbergen, were studied. A total of 30 fungal isolates were identified by morpho-taxonomy, and the identity of some morpho-taxonomically complex isolates was authenticated by ITS1-5.8S and ITS2 rDNA domain sequence similarity. The isolates belonged to 19 species under 14 genera (Acremonium, Arthrinium, Aspergillus, Cladosporium, Corynespora, Emericella, Geomyces, Mortierella, Mucor, Myrothecium, Penicillium, Phialophora, Preussia, Xylaria). To the best of our knowledge, Acremonium roseolum, Aspergillus aculeatus, Emericella nidulans, and Preussia sp. are the first northernmost records from Arctic soils. The viable fungal count in different soil samples varied from 0.5 • 104 to 2.0 • 105 g-1. Species richness in different soil samples was also calculated. Mortierella was one of the most dominant genera in Arctic soils. A temperature tolerance study was carried out for all the isolates, and representative species were screened for their extracellular enzyme activity (amylase, cellulase, phosphatase, and pectinase) at 4˚C and 20˚C. Among the 30 isolates, seven showed cellulolytic activity, two were phosphate solubilizers, three had amylolytic activity, and only one showed pectinolytic activity on solid media. CMCase (β1, 4-endoglucanase) activity was quantified in seven isolates that exhibited positive activity during preliminary screening. The records of enzyme activity for amylases, pectinases, and cellulases are the first from the fungi of Spitsbergen. The present study indicates the dominance in Ny-Ålesund of cellulolytic strains, which may serve as potent decomposers in Arctic tundra. These isolates may be used to facilitate the mineralization of cellulolytic wastes generated by human activities in colder hilly areas across the world, including the Himalayas in India.Nous avons étudié des champignons telluriques filamenteux de Ny-Ålesund, Spitzberg. Grâce à la morpho-taxonomie, nous avons identifié 30 isolats fongiques, et l’identité de certains complexes d’isolats morpho-taxonomiques a été authentifiée au moyen des similarités des séquences de domaines ITS1-5.8S et ITS2 DNAr. Les isolats relevaient de 19 espèces faisant partie de 14 genres (Acremonium, Arthrinium, Aspergillus, Cladosporium, Corynespora, Emericella, Geomyces, Mortierella, Mucor, Myrothecium, Penicillium, Phialophora, Preussia, Xylaria). Au meilleur de nos connaissances, Acremonium roseolum, Aspergillus aculeatus, Emericella nidulans et Preussia sp. constituent les premiers enregistrements aussi nordiques des sols arctiques. Le dénombrement viable de champignons dans différents échantillons de sol variait de 0,5 • 104 à 2,0 • 105 g-1. Nous avons également calculé la diversité des espèces prélevées dans différents échantillons de sol. Le genre Mortierella était l’un des plus dominants des sols arctiques. Nous avons étudié la tolérance à la température de tous les isolats, et des espèces représentatives ont été examinées du point de vue de l’activité enzymatique extracellulaire (amylase, cellulase, phosphatase et pectinase) à 4 ˚C et 20 ˚C. Parmi les 30 isolats, sept présentaient de l’activité cellulolytique, deux étaient des solubilisants du phosphate, trois présentaient de l’activité amylolytique et seulement un présentait de l’activité pectolytique dans le cas des solides. L’activité CMCase (β1, 4-endoglucanase) a été quantifiée dans sept isolats qui affichaient une activité positive au cours de l’examen préliminaire. Il s’agissait de la première fois que de l’activité enzymatique pour les amylases, pectinases et cellulases a été détectée dans les champignons de Spitzberg. Cette étude indique la dominance de souches cellulolytiques à Ny-Ålesund, souches qui peuvent servir de décomposeurs puissants dans la toundra arctique. Ces isolats peuvent servir à faciliter la minéralisation des déchets cellulolytiques émanant des activités humaines dans les régions montagneuses plus froides du monde entier, y compris l’Himalaya, en Inde
Highly Sensitive Electrospun Multiwalled Carbon Nanotubes Embedded Zinc Oxide Nanowire Based Interface for Label Free Biosensing
We demonstrate synthesis of Multiwalled carbon nanotubes (MW
CNTs) embedded highly oriented Zinc Oxide (ZnO) nanowires
targeted towards development of ultrasen
sitive electrochemical nanobiosensors using
electrospinning method. The synthesized
composite nanowires combines advantages of ZnO such as biocompa
tibility, electrostatic affinity towards biomolecules with the
excellent conductivity and surface functi
onalization capabilities of MWCNTs. Calcinatio
n temperature is optimized so as to
ensure MWCNTs are present in their original form and at the same
time highly crystalline ZnO is obtained. The key advantage o f
this process is that there is no separate functionalization pr
ocess is required to create functional groups on MWCNTs.
Furthermore, the electrochemical activity of MWCNTs embedded ZnO nanowires is much higher as compared to pure ZnO
nanowires. We have demonstrated the performance of electrochem
ical nanobiosensor using Biotin
-streptavidin interaction as
model system. The sensor exhibits excellent sensitivity in the range 10 μ gmL
-1
- 0.5 fgmL
-1
of streptavidin with 0.5fgmL
-1
limit
of detection
Successful pregnancy in a patient with Ebstein’s anomaly: a case report and review of literature
Ebstein’s anomaly, a rare congenital heart disease, has an extremely variable natural history, depending on variety of pathological features. We here describe a case of a patient with Ebstein’s anomaly who had an uneventful vaginal delivery of a healthy term baby. The anomaly was diagnosed during childhood, was not associated with other cardiac anomalies, cyanosis or pre-excitation and the echocardiographic degree of severity was low
Effect of rice husk biochar, carpet waste, farm yard manure and plant growth promoting rhizobium on the growth and yield of rice (Oryza sativa)
The present investigation was aimed for improving growth and yield of crop using waste products of differ-ent activities and also useful in ecological stability of soil environment. This objective is not only an economic option for poor farmer but also an effective strategy for increasing yield. The experiment was conducted in the organic farm-ing plot of the Institute of Agricultural Sciences, BHU, Varanasi during kharif season of rice crop in 2014. The field experiment was laid out in randomized block design (RBD) with 10 treatments and three replications. Application of graded level of biochar, carpet waste farm yard manure (FYM) and plant growth promoting rhizobium (PGPR) was found to significantly enhance the grain and straw yield of rice by 57.70% and 56.08% over control, respectively
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