Showing papers by "Government College published in 1999"

Some observations on endemic fluorosis in domestic animals in Southern Rajasthan (India).

Abstract: Chronic fluoride toxicity in the form of osteo-dental fluorosis was observed in cattle, buffaloes, sheep and goats from 21 villages of Banswara, Dungarpur and Udaipur districts of Southern Rajasthan where the mean fluoride concentration in drinking water varied from 1.5 to 4.0 ppm. The prevalence of dental fluorosis in calves ( 7 years age) at 2.8 ppm fluoride or more in the water. None of the fluorotic animals exhibited any apparent evidence of hypothyroidism, stunted growth or low milk production. There was no correlation between gender and the prevalence of fluorosis, but the prevalence and severity of skeletal fluorosis increased with increasing fluoride concentration and age. Possible factors causing variation in fluorosis in the cattle and buffaloes in villages with identical fluoride concentrations are discussed.

Chronic fluoride intoxication (fluorosis) in tribes and their domestic animals

Abstract: A chronic fluoride intoxication in the form of dental and skeletal fluorosis has been observed in tribal subjects and domestic animals (cattle and buffalo) of twelve villages; Badoda, Bhavanpura, Devala, Dhunda, Ghanta, Katisor, Khalil, Bhagela, Masona, Munged, Pindawal and Ramgarh of Dungarpur district of Rajasthan (India), where mean fluoride concentration in drinking water sources varied between 1.5 to 5.0 mg/L. The greatest prevalence of dental fluorosis in children and adult subjects was found at 3.5 and 3.7 mg/L fluoride concentration, whereas in calves and mature animals at 2.9 and 3.5 mg/L, respectively. The highest prevalence of skeletal fluorosis, 57.0% in tribes and 58.6% in animals, has been observed at 5.0 and 4.8 mg/L fluoride concentrations, respectively. Some observations pertaining to other deformities and radiological in fluorotic cases have also been focussed.

1,2-Diarylimidazoles as inhibitors of cyclooxygenase-2: a quantitative structure-activity relationship study.

Abstract: The cyclooxygenase-2 (COX-2) enzyme inhibition activity of derivatives of 1,2-diarylimidazole is analysed through Fujita-Ban and Hansch approaches. The analyses have helped to ascertain the role of different substituents in explaining the observed inhibitory potency of these analogues. From both approaches it is revealed that the more hydrophobic X-substitutions that are present at the 3- and 4-positions of the aryl ring and are also non-hydrogen acceptor in character improve inhibitory action of a compound. The smaller substituent either H or F is preferred at the 2-X position as it is involved in steric interaction. Likewise, the substituent-NH2 instead of Me at R is advantageous. Further, for a data set of 35 congeners, the selectivity ratio related to the constitutive COX-I isozyme is also analysed through the Fujita-Ban approach. The derived contributions of parent moiety and various substituents have helped to predict the substitution pattern in the design of more effective compounds that we...

Effect of mean-square amplitude of atomic vibrations on the creep behaviour of cubic crystals

Abstract: Correlation between the activation energyQ of high-temperature creep and the Debye-Waller thermal parameterB, which is proportional to the mean-square amplitude of atomic vibrations, has been examined in the case of 17 faced-centred cubic, body-centred cubic and diamond-structure cubic elements. It is observed thatQ is a function ofB, irrespective of the crystal structure;Q decreases asB increases. The correlation is governed by the power-lawQ=Q0(B/B0)M0, whereQ0=0.095eV andM0=−0.62 are numerical constants determined by least-squares fit method, and the constantB0=1 nm2.

Effect of Natural Ageing on the Strain-Rate Sensitivity of Flow Stress in High-Purity Aluminium Polycrystals

Abstract: Strain-rate-cycling experiments between 4.6 × 10 -3 s -1 and 4.6 × 10 -4 s -1 were performed with 99.996% aluminium polycrystals of mean grain-diameter 0.25, 0.36, and 0.47 mm, which had been annealed at 500°C and aged for six months at room temperature prior to deformation. Similar studies were also carried out with 500 °C annealed but unaged aluminium specimens of the same purity and grain size for comparison. It is observed that yield stress, ultimate tensile stress, fracture stress, and strain-rate sensitivity Δσ of a given flow stress σ in the range 30 to 70 MPa are not influenced by the grain size in both aged and unaged aluminium. However, natural ageing significantly enhances the yield stress as well as the strain-rate sensitivity Δσ of a given flow stress σ by 30% while ultimate tensile stress and fracture stress remain unaffected. Migration of point defects, e.g. vacancies, residual gaseous and metallic impurity atorns etc., to the cores of edge dislocations during ageing seems to be responsible for the increase in yield stress and strain-rate sensitivity of the flow stress. The analysis of the Δσ/σ data in terms of Feltham's single barrier model of plastic flow shows that the intrinsic height of the thermally activable energy barrier (3.4 eV) evaluated for aged aluminium is comparable with that (4.2 eV) for unaged aluminium, and dislocation-dislocation intersection is the rate process of plastic flow.

Loss of stress equivalence in the strain-rate sensitivity of flow stress in fine-grain polycrystalline copper

Abstract: The strain-rate sensitivity of flow stress (3.7 × 10 -3 s -1 ⇄ 3.7 × 10 -4 s -1 ) in fine-grain polycrystalline copper has been studied over the entire stress-strain curve at room temperature. It is observed that the yield stress varies with mean grain diameter (32 to 59 μm) in accord with the Hall-Petch relation, whereas ultimate tensile stress and fracture stress are independent of the grain size. The strain-rate sensitivity Δσ of a given flow stress σ depends on the grain size; it increases as grain size is increased from 32 to 59 μm. For a given grain size, the Cottrell-Stokes ratio Δσ/σ and the product of flow stress σ and associated activation volume V σ remain constant in the entire stress range 50 to 210 MPa studied. Values of both Δσ/σ and V σ σ depend on the grain size. The observations have been accounted for within the framework of Feltham's single barrier model of plastic flow.

Antifungal Effect of Five Plant Extracts on the Variants of Trichophyton rubrum

Abstract: The synthetic drugs developed against dermatophytic infections caused by Trichophyton rubrum are not altogether free of side effects. The therapeutic measures sometimes become toxic to humans. With that in view, extracts from five plants, plentifully available in India, were tested under in vitro conditions upon the variants of T. rubrum causing cutaneous and superficial skin infections at Rourkela, Orissa, India. It was observed that oils of Azadirachta indica, Pongamia glabra and extracts from the rhizomes of Curcuma longa were highly effective in inhibiting the growth of the fungal variants in this part of the world. In this paper, the in vitro minimal inhibiting concentration of these plant extracts were determined against 4 variants of T. rubrum.

Synthesis and characterization of la2ca3cu4oy

Abstract: Synthesis and characterization of La2Ca3Cu4Oy compound is reported here. The powder X-ray diffraction analysis shows that the system belongs to an orthorhombic structure and the lattice parameters are a = 3.814(4)A, b = 3.930(5)A and c = 34.772(3)A.