Browsing by Author "A.K. Jha"

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Aqueous extract of Neem leaves in treatment of psoriasis vulgaris
(1994) S.S. Pandey; A.K. Jha; V. Kaur
A double blind clinical drug trial was conducted to see the efficacy of an indigenous drug made up of aqueous extract of Neem leaves in 50 cases of uncomplicated psoriasis taking conventional coal tar regime. Patients taking drug in addition to coal tar had shown a quicker and better response in comparison to placebo group. No any untoward effect was noticed during the period of trial. Probable mode of action is discussed.
Changes with time in soil biomass C, N and P of mine spoils in a dry tropical environment
(1989) S.C. Srivastava; A.K. Jha; J.S. Singh
The data suggest that microbial biomass can be taken as a functional index of soil redevelopment. -from Authors
Closed die axisymmetric forging of sintered aluminium preforms
(Elsevier BV, 1997) G. Sutradhar; Abdulla A. Bashashwan; A.K. Jha; S. Kumar
The present work deals with an investigation into the closed-die forging of Aluminium powder preforms that have been compacted and sintered from very fine aluminium powder. The sintered preforms, of the same diameter but of different lengths, have been pressed in the cold condition. It is seen that the resistance to flow of the metal into the flash gap can be expressed in terms of the normal stress developed at the junction of the flash and the body of the forging. It appears that there exists a direct relationship between the normal stress and the flash thickness. © 1997 Elsevier Science S.A.
Compatibility of sintered materials during cold forging
(Inderscience Enterprises Ltd, 1994) A.K. Jha; S. Kumar
The present paper reports on the compatibility characteristics of sintered materials under axisymmetric and plane strain cold sinter-forging conditions. Experiments were conducted using different sintered preforms in the form of discs and rectangular strips, and measurements were made for stain variations at the free surface. The theoretical and experimental results obtained are analysed and discussed critically to explain the compatibility characteristics of sintered materials during cold forging, and there results presented graphically.
Curcumin-mediated reversal of p15 gene promoter methylation: Implication in anti-neoplastic action against acute lymphoid leukaemia cell line
(Charles University, 2015) V. Sharma; A.K. Jha; A. Kumar; A. Bhatnagar; G. Narayan; J. Kaur
Curcumin has been documented to exert anticancer effects by interacting with altered proliferative and apoptotic pathways in cancer models. In this study, we evaluated the potential of curcumin to reverse promoter methylation of the p15 gene in Raji cells and its ability to induce apoptosis and genomic instability. Anti-neoplastic action of curcumin showed an augmentation in reactive oxygen species (ROS) and cell cycle arrest in G1 phase. Subsequently, curcumin-exposed Raji cells showed structural abnormalities in chromosomes. These observations suggest that curcumin also causes ROS-mediated apoptosis and genomic instability. The treatment of Raji cell line with 10 μM curcumin caused hypomethylation of the p15 promoter after six days. Hypomethylation of p15 was further found to be favoured by down-regulation of DNA methyltransferase 1 after 10 μM curcumin treatment for six days. Methylation-specific PCR suggested demethylation of the p15 promoter. Demethylation was further validated by DNA sequencing. Reverse-transcription PCR demonstrated that treatment with curcumin (10 μM) for six days led to the up-regulation of p15 and down-regulation of DNA methyltransferase 1. Furthermore, curcumin-mediated reversal of p15 promoter methylation might be potentiated by down-regulation of DNA methyltransferase 1 expression, which was supported by cell cycle analysis. Furthermore, curcumin acts as a double-pronged agent, as it caused apoptosis and promoter hypomethylation in Raji cells. © 2015, Charles University. All rights reserved.
Effect of nutrient enrichment on native tropical trees planted on Singrauli Coalfields, India
(2000) Arvind Singh; A.K. Jha; J.S. Singh
Growth performance of nine native tropical tree species planted on mine spoil under two levels of NPK treatment was studied by measuring height and diameter. Of the nine species, four were leguminous. All the tree species responded positively to NPK fertilization; however, the impact on leguminous species was little compared to non-leguminous species. In general, the height/diameter ratio decreased from control to full-dose NPK treatment, suggesting that nutrient enrichment influenced the resource allocation pattern such that the diameter growth was favored. The log-transformed height-diameter relationships were significant for the three treatments in all the tree species. The slopes (β) obtained were compared with three different models of tree growth (i.e., elastic similarity, geometric similarity, and constant stress). Acacia catechu, Dalbergia sissoo, Gmelina arborea, and Azadirachta indica fitted the elastic similarity model, whereas Pongamia pinnata and Phyllanthus emblica followed the constant stress model. Tectona grandis was the only species that followed the geometric similarity model. In Albizia lebbeck and Terminalia bellirica, the β values were considerably lower (i.e., below 0.5) and these two species did not fit any of the three models of tree growth. In several cases the β values were considerably influenced by nutrient enrichment.
Effect of SiCp addition on age-hardening of aluminium composite and closed cell aluminium composite foam
(2007) V. Rajput; D.P. Mondal; S. Das; N. Ramakrishnan; A.K. Jha
The age hardening behavior of solid Al-alloy-SiCp composite and closed cell Al-alloy-SiCp composite cellular materials has been examined and compared. The peak aging period of these materials were also compared with that of the solid unreinforced alloy. The effect of SiCp content on the peak aging time has been examined. It was found that the composite aged faster than the alloy irrespective of SiCp content, wherein peak aging time was invariant to SiCp content. On the other hand, while the closed cell composite foam reached a peak aged condition faster than the alloy when SiCp content was less than 10 wt%, further increases in SiCp content delayed the age-hardening kinetics. © Springer Science+Business Media, LLC 2007.
Evaluation of direct seeding of tree species as a means of revegetation of coal mine spoils
(2000) A.K. Jha; Arvind Singh; A.N. Singh; J.S. Singh
[No abstract available]
Influence of a developing tree canopy on the yield of Pennisetum pedicellatum sown on a mine spoil
(Wiley-Blackwell, 1997) Arvind Singh; A.K. Jha; J.S. Singh
Shoot and root biomass yield of a sown grass, Pennisetum pedicellatum, were measured at below-canopy, canopy edge and open locations in young monoculture stands of eight tree species planted on a coalmine spoil. Incident light as percentage of full sunlight decreased from open to canopy edge to below-canopy locations. The shoot and root weights of Pennisetum in different tree stands for each of the three locations were significantly different and were significantly related to each other, and to percentage sunlight across all tree species plots and locations. The gradient of incident light was the principal factor governing the gradient of grass biomass under developing canopies of tree plantations on the mine spoil.
Influence of microsites on redevelopment of vegetation on coalmine spoils in a dry tropical environment
(1992) A.K. Jha; J.S. Singh
An age series of mine spoils (5, 10, 12, 16 and 20 years old) in a dry tropical environment was studied to assess the impact of different microsites (substrate conditions) on physico-chemical and biological characteristics of spoils, and on species composition and plant biomass levels. Impact of microsites, even after 20 years of soil and vegetation redevelopment, remained important. Undulating surface and flat surface microsites showed more or less a similar behaviour after 20 years of succession and were better habitats than slope and coalpatch margin microsites for plant growth. The present study indicated that microsite conditions should be taken into consideration in any revegetation programme and desired natural colonizing species of even higher successional order may be used to accelerate the natural revegetation process according to the post-mining land use objectives. © 1992 Academic Press Limited.
Influence of microsites on redevelopment of vegetation on coalmine spoils in a dry tropical environment
(1993) A.K. Jha; J.S. Singh
An age series of mine spoils (5, 10, 12, 16 and 20 years old) in a dry tropical environment was studied to assess the impact of different microsites (substrate conditions) on physico-chemical and biological characteristics of spoils, and on species composition and plant biomass levels. Impact of microsites, even after 20 years of soil and vegetation redevelopment, remained important. Undulating surface and flat surface microsites showed more or less a similar behaviour after 20 years of succession and were better habitats than slope and coalpatch margin microsites for plant growth. The present study indicated that microsite conditions should be taken into consideration in any revegetation programme and desired natural colonizing species of even higher successional order may be used to accelerate the natural revegetation process according to the post-mining land use objectives.
Influence of mulching on plant growth performance in young plantation plots on coal mine spoil
(2001) A.K. Jha; Arvind Singh; A.N. Singh; J.S. Singh
Plantation of Dendrocalamus strictus was raised on coal mine spoil at Jayant project, NCL, Singrauli in June 1993. Half and full dose of NPK fertilizer was applied. Full dose of NPK fertilizer was nitrogen as urea (60 kg ha-1), phosphorus as single superphosphate (30 kg ha-1) and potash as muriate of potash (40 kg ha-1). Half dose of NPK treatment increased the height growth more whereas full dose of NPK treatment enhanced markedly the number of culms/ clump and diameter growth of D. strictus.
Influence of NPK fertilization on biomass production of Pennisetum pedicellatum seeded on coal mine spoil
(1996) A. Singh; A.K. Jha; J.S. Singh
[No abstract available]
Investigation of free convection flow around near horizontal surfaces using particle image velocimetry
(American Institute of Physics Inc., 2023) A.K. Jha; P. Shukla; Pradyumna Ghosh
In this work, an analysis of free convection fluid flow characteristics around a flat heated surface, slightly inclined to the horizontal, has been carried out with the help of particle image velocimetry technique. Experiments were performed on a plate immersed in water and subjected to a uniform heat flux. The influence of different inclinations of the plate and heat fluxes on the flow characteristics has been analyzed. Based on the flow characteristics, different regimes -attached, transition, and buoyant plume regime -have been identified. It is observed that the onset of transition increases with the inclination angle and decreases with the heat flux. On the other hand, the length of the transition regime increases with an increase in the inclination angle and heat flux. The plume width or plume regime is found to first decrease due to necking and then increase in the vertical direction due to horizontal diffusion. Also, an increase in heat flux and inclination angle causes an increase in plume width at a particular height from the plate. It is observed that the inner velocity boundary layer thickness decreases in the laminar regime and increases in the transition regime along the length of the plate. © 2023 Author(s).
Otorhinolaryngological studies in diabetics
(Association of Otolaryngologists of India, 1998) M.K. Agarwal; A.K. Jha; S.K. Singh
A total of 50 patients with diabetes mellitus were the subject matter of this study. Of these, 13 patients had diabetic neuropathy on clinical evaluation. Amongst the group of patients without diabetic neuropathy, 64.86% had sensorineural hearing loss and 21.6% patients had conductive deafness as compared to patients with diabetic neuropathy having sensorineural hearing loss in 69.2% and conductive deafness in 23% cases. The hearing threshold were found to be within normal limits in diabetics with or without neuropathy at lower frequencies but it was significantly increased at higher frequencies (4000 Hz and 8000 Hz) in patients with diabetic neuropathy when compared with diabetic patients without neuropathy. The hearing threshold were increased at higher frequencies in uncontrolled diabetics. This was significant when compared with diabetics with normal fasting plasma glucose. The values of these tests as diagnostic and prognostic tools presently remains of no avail. However, it is hoped that with better precision and sophistication they may be utilised to detect finer sensorineural loss in diabetics, much before the development of long term complication inflicting the nervous system. This study also underlies the importance of looking for the hearing defects in diabetics which may be insignificant to the patient in face of apprehension for the disease itself.
Pretibial epidermolysis bullosa with intraepidermal split
(1991) S. Singh; A.K. Jha; M. Kumar; S.S. Pandey
[No abstract available]
Production of sinter-forged components
(1994) G. Sutradhar; A.K. Jha; S. Kumar
The forging of sintered metal-powder preforms is currently arousing interest in many parts of the world as an economic method of producing components from metal powders. This paper reports on an investigation into the various technological aspects of the cold forging of sintered powder preforms. The influence of the powder particle size, the compacting pressure, the sintering temperature and other forging parameters on the relative density of the preform discs of atomised iron powder at room temperature under axisymmetric conditions. hallow discs of atomised iron powder at room temperature under axisymmetric conditions. Measurements were made on the development of barrelling and strain variations at the free surface. Crack formation at the free surface was observed. The deformation characteristics and fracture mechanisms are discussed critically, to illustrate the interaction of the various parameters involved, and the results are presented graphically. Powder preform design and techno-economic advantages are discussed briefly also. © 1994.
Punch grafting in vitiligo
(1992) A.K. Jha; S.S. Pandey; V.K. Shukla
[No abstract available]
Spoil characteristics and vegetation development of an age series of mine spoils in a dry tropical environment
(Kluwer Academic Publishers, 1991) A.K. Jha; J.S. Singh
A series of coal mine spoils (5, 10, 12, 16 and 20-yr old) in a dry tropical environment was sampled to assess the changes with time in spoil characteristics, species composition and plant biomass. Coarse fragments (>2 mm) decreased with age of mine spoil while the proportion of 0.2-0.1 mm particles increased. Total soil N, mineral N, NaHCO3-extractable Pi, and exchangeable K increased with age of mine spoil and these parameters were lower in mine spoils than native forest soil even after 20 years of succession. Exchangeable Na decreased with age of mine spoil and in 20-yr old spoil it was higher than native forest soil. Plant community composition changed with age. Only a few species participated in community formation. Species richness increased with age, while evenness and species diversity declined from 5-yr old to 16-yr old community with an increase in the 20-yr old community. A reverse trend occurred for concentration of dominance. Area-weighted shoot and root biomass of other species increased with the age of the mine spoil while that of Xanthium strumarium patches declined with age. Data collected on spoil features, microbial C, N and P, and shoot and root biomass when subjected to Discriminant Analysis indicated a continued profound effect of age. 10 and 12-yr old mine spoils were closer to each other, and 5 and 20-yr old spoils were farthest apart. © 1991 Kluwer Academic Publishers.
Study of deafness in diabetics with special reference to neuropathy
(2001) A.K. Jha; M.K. Agarwal; S.K. Singh
A total of 50 patients with diabetes mellitus were studied. Out of these, 13 patients had diabetic neuropathy on clinical evaluation. Amongst the group of patients without diabetic neuropathy, 64.86% had sensorineural hearing loss and 21.6% patients had conductive deafness. Patients with diabetic neuropathy had sensorineural hearing loss in 69.2% cases and conductive deafness in 23% patients. The hearing threshold were found to be within normal limit in diabetics with or without neuropathy at lower frequencies but it was significantly increased at higher frequencies (4000 HZ and 8000 HZ) in patients with diabetic neuropathy when compared with diabetic patients without neuropathy. The hearing threshold was increased at higher frequencies in uncontrolled diabetics. This was significant when compared with diabetics with normal fasting plasma glucose.