Electron diffraction has revealed changes in the cation ordering and new long-range orders in cyc... more Electron diffraction has revealed changes in the cation ordering and new long-range orders in cycled Li x Ni0. 5Mn0. 5O2. Li, Ni, and vacancies are not randomly distributed and they may order in the tetrahedral sites of the Li layer in a 2 a Hex.× 2 a Hex.× c Hex. supercell ...
ABSTRACT Li/LiNi0.5Mn0.5O2 cells were cycled galvanostatically to 4.5 and 5.3 V at different curr... more ABSTRACT Li/LiNi0.5Mn0.5O2 cells were cycled galvanostatically to 4.5 and 5.3 V at different current densities. Cycling to 5.3 V was shown to not only improve the reversible capacities and rate capability upon subsequent cycling in the voltage range of 4.5 and 2.0 V, but also to lead to the appearance of a reversible process at 4.3 V. LixNi0.5Mn0.5O2 electrodes exposed initially to 5.3 V were found to exhibit stable, reversible capacities of similar to 190 mAh/g upon subsequent cycling to 4.5 V, which were considerably higher than those of electrodes (similar to 170 mAh/g) cycled only to 4.5 V for the identical number of cycles. The changes in the crystal structure of layered O3 LixNi0.5Mn0.5O2 were investigated by synchrotron X-ray powder diffraction and electron diffraction studies. Rietveld refinement analyses of X-ray diffraction data showed that octahedral nickel migrated from the lithium layer to transition metal layer, and to tetrahedral sites occurred upon cycling to 4.5 V. Increasing the charging voltage to 5.3 V appeared to remove all of the tetrahedral nickel and further increased the occupancy of octahedral nickel in the transition metal layer. The formation of O1 [ ]Ni0.5Mn0.5O2 having hexagonal close-packed oxygen array was revealed in the electrode charged to 5.3 V by X-ray and electron diffraction. The changes in the cation arrangements of the LixNi0.5Mn0.5O2 structure are discussed with respect to lithium reactivity, reversible capacities, and lithium mobility. (c) 2007 The Electrochemical Society.
A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calcula... more A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calculations have been used to determine and rationalize the structural changes that occur during cycling of the layered material Li x (Ni0. 5Mn0. 5) O2 (x= 1), synthesized via the ...
ABSTRACT Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat ... more ABSTRACT Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat (Triticum aestivum L. em. Thell), resulting in significant yield losses, sometimes up to 40% worldwide. In this study we investigated slow rusting resistance at pathological and molecular level. Fifteen (15) wheat genotypes which also included multiple crosses with the aim to characterize pyramid resistance genes, including slow rusting genes like Lr46 and Lr50 were evaluated for disease severity percent, latent period and incubation period under field conditions. Detached leaf assay was also performed with three virulent pathotypes viz., 21R55 (104-2), 121R63-1 (77-5) and 29R45 (12-5), under controlled laboratory conditions. Genotypes, KIRITATAI//HUW234+LR34/PRINIA, WAXWING*2/TUKURU, WBLLI*2/KIRITATI, KAMBI*2/-BRAMBLING and KAMBI*2/KIRITATI were very close to near immunity and showed comparatively higher level of resistance against all the three pathotypes. Disease severity in resistant genotypes was traced type 5 to 6% in both years, while it was 60 to 80% in the case of susceptible genotypes, that is, 'Agra Local' (S1). Similar pattern was observed for AUDPC, that is, <250.0 in the resistant genotypes, while it was beyond 1000.0 in 'Agra Local'. The shorter mean latent (7.67) and incubation period (6.0) was observed in susceptible genotypes, that is, 'Agra Local' to all the resistant genotypes, that is, LP (10 to 12) and IP (9 to 10); while testing against all the three different pathotypes. Linked microsatellite markers were used to confirm the presence of different rust resistance genes required to achieve near immunity. Out of 10 primers, nine produced gene specific bands with all genotypes except the control, that is, Agra Local. Genotypes which showed slow rusting, had longer latent period and incubation period as well as reduced percent disease severity and confirmed the presence of four to five resistance genes including slow rusting genes, that is, Lr46 and Lr50. This indicates that these genotypes have potential durable resistance and can be used as parental lines in the development of more durable rust resistance.
The Nanostructured Origami {trade mark, serif} process is a novel fabrication and assembly method... more The Nanostructured Origami {trade mark, serif} process is a novel fabrication and assembly method that is ideal for creating nanostructured devices with a three-dimensional (3D) geometry. In this paper, we describe the application of this new technique to the ...
cells were cycled galvanostatically to 4.5 and at different current densities. Cycling to was sho... more cells were cycled galvanostatically to 4.5 and at different current densities. Cycling to was shown to not only improve the reversible capacities and rate capability upon subsequent cycling in the voltage range of 4.5 and, but also to lead to the appearance of a reversible ...
A study was undertaken to examine the main source of inoculum of Bipolaris sorokiniana responsibl... more A study was undertaken to examine the main source of inoculum of Bipolaris sorokiniana responsible for its reappearance in rice–wheat cropping regions of eastern India. Soil samples were collected at monthly intervals during April–October in the years 2000 and 2001 from fields having rice–wheat cropping. Bipolaris sorokiniana conidia were isolated and their viability was found to decline sharply with the
ABSTRACT Drought tolerance was investigated in ‘C306’, one of the most drought tolerant wheat cul... more ABSTRACT Drought tolerance was investigated in ‘C306’, one of the most drought tolerant wheat cultivars bred in India in the 1960’s. An intervarietal mapping population of recombinant inbred lines of the cross ‘C306’ × ‘HUW206’ was evaluated for drought tolerance components, namely potential quantum efficiency of photosystem (PS) II (Fv/Fm), chlorophyll content (Chl), flag leaf temperature (Lt), and grain yield per plant (Gyp) under stress. Three independent experiments were conducted under well-watered and water-stressed conditions in greenhouses and growth chambers at Kansas State University (USA). Five hundred and sixty microsatellite markers covering the entire genome were screened for polymorphism between the parents. A QTL (QLt.ksu-1D) for Lt (low flag leaf temperature under stress) on the short arm of chromosome 1D between markers Xbarc271 and Xgwm337 at LOD 3.5 explained 37% of the phenotypic variation. A QTL for Fv/Fm (QF v /F m .ksu-3B) and Chl (QChl.ksu-3B) controlling quantum efficiency of PS II and chlorophyll content under stress were co-localized on chromosome 3B in the marker interval Xbarc68–Xbarc101 and explained 35–40% of the phenotypic variation for each trait. A QTL (QGyp.ksu-4A) for Gyp on chromosome 4A at a LOD value of 3.2 explained 16.3% of the phenotypic variation. Inconsistent QTLs were observed for Fv/Fm on chromosomes 3A, 6A, 2B, 4B, and 4D; for Chl on 3A, 6A, 2B and 4B; and for Lt on 1A, 3A 6A, 3B and 5B. The identified QTLs give a first glimpse of the genetics of drought tolerance in C306 and need to be validated in field experiments using the marker-phenotype linkages reported here.
Conductivity hysteresis and room temperature ionic conductivities> 10− 3S/cm were recently... more Conductivity hysteresis and room temperature ionic conductivities> 10− 3S/cm were recently reported for electrolytes prepared from blends of an amphiphilic comb copolymer, poly [2, 5, 8, 11, 14-pentaoxapentadecamethylene (5-hexadecyloxy-1, 3-phenylene)](polymer I), and ...
One hundred fifty-five isolates of Bipolaris sorokiniana of wheat were studied for their morphopa... more One hundred fifty-five isolates of Bipolaris sorokiniana of wheat were studied for their morphopathological characterization. These isolates were grouped in five categories--black, brown/dull black, gray cottony growth, dull white/greenish black, and white--on the basis of their growth pattern. The frequency of the black suppressed type was maximum (45.63%), whereas the white isolate displayed lowest frequency (6.96%) in the natural population. Twenty RAPD (random amplified polymorphic DNA) primers were used to observe the variability among the identified groups of B. sorokininana. From each group, eight random isolates were investigated. A total of 143 bands were amplified, out of which 107 (74.83%) were polymorphic and 36 (25.17%) were monomorphic. On an average, the total numbers of bands generated per primer were 7.15, of which 5.35 and 1.80 were polymorphic and monomorphic, respectively. Dendrograms based on molecular polymorphism unveiled a considerable amount of diversity among the isolates. Specific DNA bands were identified for selected isolates. The distinct markers appeared to be potential enough to be employed as genetic fingerprints for future strain identification and classification. The study indicated that the RAPD primers provide an easy, rapid, and simple technique for the preliminary assessment of genetic diversity among the fungal isolates.
ABSTRACT Spot blotch, caused by Bipolaris sorokiniana (Sacc.) Shoem. syn. Drechslera sorokiniana ... more ABSTRACT Spot blotch, caused by Bipolaris sorokiniana (Sacc.) Shoem. syn. Drechslera sorokiniana (Sacc.) Subrm and Jain (syn. Helminthosporium sativum, teleomorph Cochliobolus sativus), is an important disease of wheat (Triticum aestivum L.) in warmer and humid regions of the world. To date, no morphological marker is known to be associated with resistance to this disease. The purpose of this study was to find out the association of leaf tip necrosis (Ltn) with resistance to spot blotch disease. A total of 1407 spring wheat genotypes that originated from the Indian and CIMMYT wheat breeding programs were evaluated for Ltn and resistance to spot blotch for three seasons (1994-1995, 1995-1996, and 1996-1997) under field conditions. Disease severity was recorded at six growth stages under artificially created epidemics. About 75% of the genotypes showing Ltn (Ltn+) were resistant or moderately resistant, whereas 82% not showing it (Ltn-) were moderately susceptible or susceptible. Mean spot blotch rating of the Ltn+ genotypes was significantly lower than the Ltn- genotypes at all growth stages and the genotype x environment interaction was nonsignificant. To confirm the association of Ltn with resistance, individual F2-derived F3, F4, F5, and F6 progenies from the cross of the 'HUW234' near-isogenic pair for Ltn were evaluated for spot blotch severity. In each generation, the Ltn+ homozygons progenies had significantly less disease than those homozygous Ltn-. These results confirm that leaf tip necrosis is associated with moderate resistance to spot blotch and can be used as a morphological marker to facilitate selection for resistance.
Electron diffraction has revealed changes in the cation ordering and new long-range orders in cyc... more Electron diffraction has revealed changes in the cation ordering and new long-range orders in cycled Li x Ni0. 5Mn0. 5O2. Li, Ni, and vacancies are not randomly distributed and they may order in the tetrahedral sites of the Li layer in a 2 a Hex.× 2 a Hex.× c Hex. supercell ...
A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calcula... more A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calculations have been used to determine and rationalize the structural changes that occur during cycling of the layered material Li x (Ni0. 5Mn0. 5) O2 (x= 1), synthesized via the ...
Electron diffraction has revealed changes in the cation ordering and new long-range orders in cyc... more Electron diffraction has revealed changes in the cation ordering and new long-range orders in cycled Li x Ni0. 5Mn0. 5O2. Li, Ni, and vacancies are not randomly distributed and they may order in the tetrahedral sites of the Li layer in a 2 a Hex.× 2 a Hex.× c Hex. supercell ...
ABSTRACT Li/LiNi0.5Mn0.5O2 cells were cycled galvanostatically to 4.5 and 5.3 V at different curr... more ABSTRACT Li/LiNi0.5Mn0.5O2 cells were cycled galvanostatically to 4.5 and 5.3 V at different current densities. Cycling to 5.3 V was shown to not only improve the reversible capacities and rate capability upon subsequent cycling in the voltage range of 4.5 and 2.0 V, but also to lead to the appearance of a reversible process at 4.3 V. LixNi0.5Mn0.5O2 electrodes exposed initially to 5.3 V were found to exhibit stable, reversible capacities of similar to 190 mAh/g upon subsequent cycling to 4.5 V, which were considerably higher than those of electrodes (similar to 170 mAh/g) cycled only to 4.5 V for the identical number of cycles. The changes in the crystal structure of layered O3 LixNi0.5Mn0.5O2 were investigated by synchrotron X-ray powder diffraction and electron diffraction studies. Rietveld refinement analyses of X-ray diffraction data showed that octahedral nickel migrated from the lithium layer to transition metal layer, and to tetrahedral sites occurred upon cycling to 4.5 V. Increasing the charging voltage to 5.3 V appeared to remove all of the tetrahedral nickel and further increased the occupancy of octahedral nickel in the transition metal layer. The formation of O1 [ ]Ni0.5Mn0.5O2 having hexagonal close-packed oxygen array was revealed in the electrode charged to 5.3 V by X-ray and electron diffraction. The changes in the cation arrangements of the LixNi0.5Mn0.5O2 structure are discussed with respect to lithium reactivity, reversible capacities, and lithium mobility. (c) 2007 The Electrochemical Society.
A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calcula... more A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calculations have been used to determine and rationalize the structural changes that occur during cycling of the layered material Li x (Ni0. 5Mn0. 5) O2 (x= 1), synthesized via the ...
ABSTRACT Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat ... more ABSTRACT Leaf rust caused by Puccinia triticina, is a globally important fungal disease of wheat (Triticum aestivum L. em. Thell), resulting in significant yield losses, sometimes up to 40% worldwide. In this study we investigated slow rusting resistance at pathological and molecular level. Fifteen (15) wheat genotypes which also included multiple crosses with the aim to characterize pyramid resistance genes, including slow rusting genes like Lr46 and Lr50 were evaluated for disease severity percent, latent period and incubation period under field conditions. Detached leaf assay was also performed with three virulent pathotypes viz., 21R55 (104-2), 121R63-1 (77-5) and 29R45 (12-5), under controlled laboratory conditions. Genotypes, KIRITATAI//HUW234+LR34/PRINIA, WAXWING*2/TUKURU, WBLLI*2/KIRITATI, KAMBI*2/-BRAMBLING and KAMBI*2/KIRITATI were very close to near immunity and showed comparatively higher level of resistance against all the three pathotypes. Disease severity in resistant genotypes was traced type 5 to 6% in both years, while it was 60 to 80% in the case of susceptible genotypes, that is, 'Agra Local' (S1). Similar pattern was observed for AUDPC, that is, <250.0 in the resistant genotypes, while it was beyond 1000.0 in 'Agra Local'. The shorter mean latent (7.67) and incubation period (6.0) was observed in susceptible genotypes, that is, 'Agra Local' to all the resistant genotypes, that is, LP (10 to 12) and IP (9 to 10); while testing against all the three different pathotypes. Linked microsatellite markers were used to confirm the presence of different rust resistance genes required to achieve near immunity. Out of 10 primers, nine produced gene specific bands with all genotypes except the control, that is, Agra Local. Genotypes which showed slow rusting, had longer latent period and incubation period as well as reduced percent disease severity and confirmed the presence of four to five resistance genes including slow rusting genes, that is, Lr46 and Lr50. This indicates that these genotypes have potential durable resistance and can be used as parental lines in the development of more durable rust resistance.
The Nanostructured Origami {trade mark, serif} process is a novel fabrication and assembly method... more The Nanostructured Origami {trade mark, serif} process is a novel fabrication and assembly method that is ideal for creating nanostructured devices with a three-dimensional (3D) geometry. In this paper, we describe the application of this new technique to the ...
cells were cycled galvanostatically to 4.5 and at different current densities. Cycling to was sho... more cells were cycled galvanostatically to 4.5 and at different current densities. Cycling to was shown to not only improve the reversible capacities and rate capability upon subsequent cycling in the voltage range of 4.5 and, but also to lead to the appearance of a reversible ...
A study was undertaken to examine the main source of inoculum of Bipolaris sorokiniana responsibl... more A study was undertaken to examine the main source of inoculum of Bipolaris sorokiniana responsible for its reappearance in rice–wheat cropping regions of eastern India. Soil samples were collected at monthly intervals during April–October in the years 2000 and 2001 from fields having rice–wheat cropping. Bipolaris sorokiniana conidia were isolated and their viability was found to decline sharply with the
ABSTRACT Drought tolerance was investigated in ‘C306’, one of the most drought tolerant wheat cul... more ABSTRACT Drought tolerance was investigated in ‘C306’, one of the most drought tolerant wheat cultivars bred in India in the 1960’s. An intervarietal mapping population of recombinant inbred lines of the cross ‘C306’ × ‘HUW206’ was evaluated for drought tolerance components, namely potential quantum efficiency of photosystem (PS) II (Fv/Fm), chlorophyll content (Chl), flag leaf temperature (Lt), and grain yield per plant (Gyp) under stress. Three independent experiments were conducted under well-watered and water-stressed conditions in greenhouses and growth chambers at Kansas State University (USA). Five hundred and sixty microsatellite markers covering the entire genome were screened for polymorphism between the parents. A QTL (QLt.ksu-1D) for Lt (low flag leaf temperature under stress) on the short arm of chromosome 1D between markers Xbarc271 and Xgwm337 at LOD 3.5 explained 37% of the phenotypic variation. A QTL for Fv/Fm (QF v /F m .ksu-3B) and Chl (QChl.ksu-3B) controlling quantum efficiency of PS II and chlorophyll content under stress were co-localized on chromosome 3B in the marker interval Xbarc68–Xbarc101 and explained 35–40% of the phenotypic variation for each trait. A QTL (QGyp.ksu-4A) for Gyp on chromosome 4A at a LOD value of 3.2 explained 16.3% of the phenotypic variation. Inconsistent QTLs were observed for Fv/Fm on chromosomes 3A, 6A, 2B, 4B, and 4D; for Chl on 3A, 6A, 2B and 4B; and for Lt on 1A, 3A 6A, 3B and 5B. The identified QTLs give a first glimpse of the genetics of drought tolerance in C306 and need to be validated in field experiments using the marker-phenotype linkages reported here.
Conductivity hysteresis and room temperature ionic conductivities> 10− 3S/cm were recently... more Conductivity hysteresis and room temperature ionic conductivities> 10− 3S/cm were recently reported for electrolytes prepared from blends of an amphiphilic comb copolymer, poly [2, 5, 8, 11, 14-pentaoxapentadecamethylene (5-hexadecyloxy-1, 3-phenylene)](polymer I), and ...
One hundred fifty-five isolates of Bipolaris sorokiniana of wheat were studied for their morphopa... more One hundred fifty-five isolates of Bipolaris sorokiniana of wheat were studied for their morphopathological characterization. These isolates were grouped in five categories--black, brown/dull black, gray cottony growth, dull white/greenish black, and white--on the basis of their growth pattern. The frequency of the black suppressed type was maximum (45.63%), whereas the white isolate displayed lowest frequency (6.96%) in the natural population. Twenty RAPD (random amplified polymorphic DNA) primers were used to observe the variability among the identified groups of B. sorokininana. From each group, eight random isolates were investigated. A total of 143 bands were amplified, out of which 107 (74.83%) were polymorphic and 36 (25.17%) were monomorphic. On an average, the total numbers of bands generated per primer were 7.15, of which 5.35 and 1.80 were polymorphic and monomorphic, respectively. Dendrograms based on molecular polymorphism unveiled a considerable amount of diversity among the isolates. Specific DNA bands were identified for selected isolates. The distinct markers appeared to be potential enough to be employed as genetic fingerprints for future strain identification and classification. The study indicated that the RAPD primers provide an easy, rapid, and simple technique for the preliminary assessment of genetic diversity among the fungal isolates.
ABSTRACT Spot blotch, caused by Bipolaris sorokiniana (Sacc.) Shoem. syn. Drechslera sorokiniana ... more ABSTRACT Spot blotch, caused by Bipolaris sorokiniana (Sacc.) Shoem. syn. Drechslera sorokiniana (Sacc.) Subrm and Jain (syn. Helminthosporium sativum, teleomorph Cochliobolus sativus), is an important disease of wheat (Triticum aestivum L.) in warmer and humid regions of the world. To date, no morphological marker is known to be associated with resistance to this disease. The purpose of this study was to find out the association of leaf tip necrosis (Ltn) with resistance to spot blotch disease. A total of 1407 spring wheat genotypes that originated from the Indian and CIMMYT wheat breeding programs were evaluated for Ltn and resistance to spot blotch for three seasons (1994-1995, 1995-1996, and 1996-1997) under field conditions. Disease severity was recorded at six growth stages under artificially created epidemics. About 75% of the genotypes showing Ltn (Ltn+) were resistant or moderately resistant, whereas 82% not showing it (Ltn-) were moderately susceptible or susceptible. Mean spot blotch rating of the Ltn+ genotypes was significantly lower than the Ltn- genotypes at all growth stages and the genotype x environment interaction was nonsignificant. To confirm the association of Ltn with resistance, individual F2-derived F3, F4, F5, and F6 progenies from the cross of the 'HUW234' near-isogenic pair for Ltn were evaluated for spot blotch severity. In each generation, the Ltn+ homozygons progenies had significantly less disease than those homozygous Ltn-. These results confirm that leaf tip necrosis is associated with moderate resistance to spot blotch and can be used as a morphological marker to facilitate selection for resistance.
Electron diffraction has revealed changes in the cation ordering and new long-range orders in cyc... more Electron diffraction has revealed changes in the cation ordering and new long-range orders in cycled Li x Ni0. 5Mn0. 5O2. Li, Ni, and vacancies are not randomly distributed and they may order in the tetrahedral sites of the Li layer in a 2 a Hex.× 2 a Hex.× c Hex. supercell ...
A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calcula... more A combination of neutron diffraction, 6Li MAS NMR, electrochemistry, and first principles calculations have been used to determine and rationalize the structural changes that occur during cycling of the layered material Li x (Ni0. 5Mn0. 5) O2 (x= 1), synthesized via the ...
Uploads
Papers by Sundeep Kumar