oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2018 ( 2 )

2017 ( 745 )

2016 ( 1207 )

2015 ( 17007 )

自定义范围…

匹配条件: “M. K. Chaubey” ,找到相关结果约492463条。
列表显示的所有文章,均可免费获取
第1页/共492463条
每页显示
Acute, Lethal and Synergistic Effects of Some Terpenes Against Tribolium castaneum Herbst (Coleoptera: Tenebrionidae)
M. K. Chaubey
Ecologia Balkanica , 2012,
Abstract: Terpenes are found in abundance in all plant essential oils. In the present study two pure volatile compounds of terpene group, α-pinene and β-caryophyllene have been evaluated for their repellent, acute toxicity and developmental inhibitory activities alone and in binary combination against red flour beetle Tribolium castaneum. In repellency assay, α-pinene and β-caryophyllene repelled T. castaneum adults significantly even at 0.025% concentrations. Fumigation of larvae and adults of T. castaneum with these two compounds caused lethality in them. Median lethal concentrations (LC50) of α-pinene and β-caryophyllene against adults were 0.998 and 1.624 μl/cm3 and against larvae were 1.379 and 1.949 μl/cm3 respectively. In binary combination, the LC50 values against adults and larvae were found 1.277 and 1.438 μl/cm3 respectively. Fumigation with two sublethal concentrations viz. 40 and 80% of 24-h LC50 of these two compunds alone and in binary combination significantly reduced oviposition potential of adults and inhibited pupation and adult emergence in larvae. All the responses were found concentration-dependent. From the present study, it can be concluded that α-pinene is more active than β-caryophyllene and these two volatile compounds in binary combination shows synergism and thus, can used as efficient insecticidal tool against T. castaneum as fumigant either alone or in combination.
Fumigant Toxicity of Essential Oils Against Rice Weevil Sitophilus oryzae L.(Coleoptera: Curculionidae)
M.K. Chaubey
Journal of Biological Sciences , 2011,
Abstract: Essential oils being natural products, biodegradable and ecologically safe are emerging candidates as replacement of synthetic pesticides in pest management programme. In the present study, essential oils were isolated by hydrodistillating dried fruits of Cuminum cyminum (Apiaceae) and Piper nigrum (Piperaceae) and its repellant, fumigant toxicity and effect on acetylcholinesterase enzyme (AChE) activity was determined against rice weevil, Sitophilus oryzae. C. cyminum and P. nigrum essential oils showed significant (p<0.05) repellant activity and caused fumigant toxicity in S. oryzae adults with median lethal concentrations (LC50) 0.67 and 0.58 L cm-3 air, respectively. Fumigation of S. oryzae adults with sublethal concentrations of C. cyminum and P. nigrum essential oils significantly (p<0.05) inhibited AChE activity. Reduction in AChE activity was 77.38 and 50.0 and 75.0 and 53.57% of the control after 24 h of fumigation with 40 and 80% of 24-h LC50 of C. cyminum and P. nigrum essential oils, respectively. In conclusion, these essential oils probably induce toxicity in insects by inhibiting AChE activity.
Relative Determination of Micronutrients of Different Species of Teff (Eragrestis) Seeds of Ethiopia Origin by Calibration Free Laser Induced Breakdown Spectroscopy Techniques
M. Dilbetigle Assefa,A.K. Chaubey,Awoke Taddess,A.Yihunie Hibstie
Advance Journal of Food Science and Technology , 2013,
Abstract: The laser-induced breakdown spectroscopy techniques has been used to analysis the multi-component of three different species of Teff seeds (Red, White and Sirgegna) of Ethiopia origin using a second harmonic (532 nm) of a nanosecond Q-switched Nd: YAG laser focused on the surface of the pelletized powder of Teff seeds. Based on the idea of the plasma is homogeneous. The seven essential micronutrients in three species of Teff seeds are identified carbon as a matrix element. Electron density and plasma temperature are calculated applying Saha-Boltzmann equation and Boltzmann plot method. And making use of the semi-quantitative method the three species relative concentrations of (Ca, Mg, Al, Si, Mn, Fe and K) are obtained using Calibration Free Laser Induced Breakdown Spectroscopy (CF-LIBS) technique. The result demonstrated that the relative concentrations of the some elements in the species are different. In Red Teff species Ca is more, but Mg is least. On the contrary Mg is high in Sirgegna and White Teff as compared to Red Teff And High content of Calcium, Magnesium and Iron micronutrients are found in the three species.
Aglossia: A case report
Kumar Prashant,Chaubey K
Journal of the Indian Society of Pedodontics and Preventive Dentistry , 2007,
Abstract: A female child of 4 years with congenital absence of tongue has been described. This anomaly is usually associated with other congenital defects particularly limb and other cranio-facial defects. But in this case, the child enjoys the normal life, the unusual absence of tongue; she used to go to school play around with her friends and had a comparable I.Q.
A Novel Packet Switch Node Architecture for Contention Resolution in Synchronous Optical Packet Switched Networks  [PDF]
Virendra Singh SHEKHAWAT, Dinesh Kumar TYAGI, V. K. CHAUBEY
Int'l J. of Communications, Network and System Sciences (IJCNS) , 2009, DOI: 10.4236/ijcns.2009.26062
Abstract: Packet contention is a key issue in optical packet switch (OPS) networks and finds a viable solution by including optical buffering techniques incorporating fiber delay lines (FDLs) in the switch architecture. The present paper proposes a novel switch architecture for packet contention resolution in synchronous OPS network employing the packet circulation in FDLs in a synchronized manner. A mathematical model for the proposed switch architecture is developed employing packet queuing control to estimate the blocking probability for the incoming traffic. The switch performance is analyzed with a suitable contention resolution al-gorithm through the computer simulation. The simulation results substantiate the proposed model for the switch architecture.
Black Carbon Aerosol over a High Altitude (~ 4.52 km) Station in Western Indian Himalayas
Jai Prakash Chaubey,S Suresh Babu,Mukunda M Gogoi,Sobhan Kumar Kompalli,V Sreekanth,K Krishna Moorthy,Tushar P Prabhu
Journal of the Institute of Engineering , 2011, DOI: 10.3126/jie.v8i3.5930
Abstract: Continuous measurements of mass concentration of Black Carbon (BC) aerosols, measured from a high altitude (~ 4.5 km above msl) location, Hanle (32.78°N, 78.95°E) in the western Himalayas, during August 2009 to July 2010 have been examined. The day-to-day variations in BC mass concentration (MB) were rather subdued in winter months while quite conspicuous during the spring months. It showed a well defined annual cycle with a maximum (109 ± 78 ng m-3) during spring and minimum during the winter (66 ± 62 ng m-3) season with an annual average MB of 78 ± 64 ng m-3. Examining the frequency distribution, it was found that 64 % of the values were below annual mean MB showing a rather pristine nature for this near free tropospheric region. Trajectory clustering and concentration weighted trajectory (CWT) analysis indicated that, most of the year, the site is influenced from the advection from west and south west Asian locations and only for a small period from the Indo-Gangetic Plains (IGP). The observations are compared with other high altitude measurements, over the globe in general and around the Himalayan region.
Columnar Aerosol Extinction Characteristics: Measurements from a Free-Tropospheric Observatory in Western-Himalayas
Mukunda M Gogoi,Jai Prakash Chaubey,V Sreekanth,Sobhan Kumar Kompalli,S Suresh Babu,Tushar P Prabhu,K Krishna Moorthy
Journal of the Institute of Engineering , 2011, DOI: 10.3126/jie.v8i3.5931
Abstract: Continuous measurements of spectral aerosol optical depths (AOD) were made over a very high altitude aerosol observatory at Hanle (32.76°N, 78.95°E, 4520 m amsl), during the summer and autumn of 2009 and 2010, by using a 10-channel multi-wavelength radiometer (MWR). The results depicted very low values of AOD (with a mean for the measurement period as ~ 0.071 ± 0.003 at 500 nm), but with a spectral dependence that changed with the months from ~ 0.8 to 1.3, with a mean value of ~ 1.01 ± 0.06. The AODs though were in general comparable to those seen over pristine Antarctic environments, are quite significant when we consider the altitude of the station. The details are presented.
Aerosol Number Size Distribution Measurements at Hanle, a Free Tropospheric High-Altitude Site in Western Himalayas
Sobhan Kumar Kompalli,V Sreekanth,Jai Prakash Chaubey,Mukunda M Gogoi,S Suresh Babu,Tushar P Prabhu,K Krishna Moorthy
Journal of the Institute of Engineering , 2011, DOI: 10.3126/jie.v8i3.5940
Abstract: Aerosol characteristics over the high altitude stations, akin to pristine and free conditions are important to understand the background aerosol features against which polluted and urban environments could be compared. In addition it is also important to monitor the changes brought about by the large-scale processes, which result in lofting and transporting of aerosols from different source regions to higher altitude levels. Moreover, these aerosols have a significant role in modifying clouds especially cold clouds. The availability of significant amount of solar UV radiation at these altitudes, along with water vapour and OH, if present, makes these regions conducive for formation of new particles from gas phase reaction products involving precursors of natural or anthropogenic origin. Such processes play a significant role in modulating the size distribution of free tropospheric aerosols and hence their radiative impacts. In this work, aerosol number size distribution measurements carried out from a high altitude free tropospheric Himalayan location, Hanle (32.78°N, 78.96°E, 4530 m amsl) during the period from May through December 2010 are examined. The monthly mean total number concentration (Nt) increased from May (614 ± 188 cm-3) to October (1498 ± 792 cm-3) and decreased slightly through December (1158 ± 470 cm-3). Fine mode aerosols (size < 100nm) contributed mostly to the total number concentration. The fractional contribution of the fine mode aerosols to the total number concentration, showed a clear increasing trend from May (~ 0.57) to December (~ 0.81). The number size distribution, which remained unimodal in May, June months with a mode in accumulation size range (around 100nm), changed to a bimodal distribution subsequently with a mode in the nucleation size range (< 25nm), indicating the possibility of new particle formation. The results are discussed in light of the possible association between the variation of the aerosol number concentration to long-range transport and thermally driven mesoscale processes such as mountain/valley winds.
Hypersurfaces of a Projective Randers conformal change
V. K. Chaubey,Pradeep Kumar
Mathematics , 2015,
Abstract: In the year 1984 Shibata investigated the theory of a change which is called a $ \beta $-change of a Finsler metric. On the other hand in 1985 a systematic study of geometry of hypersurfaces in Finsler spaces was given by Matsumoto. In the present paper is to devoted to the study of a condition for a Randers conformal change to be projective and find out when a totally geodesic hypersurface $ F^{n-1} $ remains to be a totally geodesic hypersurface $ F^{n-1} $ under the projective Randers conformal change. Further obatined the condition under which a Finslerian hypersurfaces given by the projective Randers conformal change are projectively flat.
Bianchi Type- III and Kantowski-Sachs Universes with wet Dark Fluid  [PDF]
Raghavendra Chaubey
International Journal of Astronomy and Astrophysics (IJAA) , 2011, DOI: 10.4236/ijaa.2011.12005
Abstract: The Bianchi type- III and Kantowski-Sachs (KS) Universes filled with dark energy from a wet dark fluid has been considered. A new equation of state for the dark energy component of the universe has been used. It is modeled on the equation of state ρ=γ(ρ -ρ *) , which can describe a liquid, for example water. The exact solutions to the corresponding field equations are obtained in quadrature form. The solution for constant deceleration parameter have been studied in detail for power-law and exponential forms both. The case γ = 0,γ =1,and γ =1/3have been also analysed.
第1页/共492463条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.