Masood Alam

Corrosion in titanium dental implants: literature review

The corrosion of dental biomaterials is a pertinent clinical issue. In spite of the recent innovative metallurgical and technological advances and remarkable progress in the design and development of surgical and dental materials, failures do occur. The present article describes the problem of corrosion in titanium dental implants. The clinical significance of the dental implant corrosion is highlighted and the most common form of corrosion i.e. galvanic corrosion is emphasized both in vitro and in vivo conditions. The article is presented keeping in view of carrying out different studies for indigenous titanium dental implant and indigenous alloys. The Department of Dental Research at Institute of Nuclear Medicine & Allied Sciences has developed indigenous Titanium Dental Implants and Base metal Alloys. The studies carried out have proven their biocompatibility and suitability to be used for oral defects. The aim of the study is to evaluate galvanic corrosion current around indigenously developed Titanium Dental Implant when coupled to a Base metal Alloy.

Hydrochemical investigation and quality assessment of ground water in rural areas of Delhi, India

The suitability of groundwater quality for drinking and agricultural purposes was assessed in the rural areas of Delhi based on the various water quality parameters. A total of 50 ground water samples were collected randomly from different sources viz. hand pump, tube well, boring and analyzed for major ion chemistry to understand the operating mechanism of geochemical processes for ground water quality. The quality analysis is performed through the estimation of pH, EC, TDS, total hardness, total alkalinity, Na, K, Cl, NO3, SO4, DO, BOD, Cu, Cr, Cd, Ni, Zn and Pb. Hydrochemical facies were identified using Piper, Durov and Chadha diagram. Chemical data were also used for mathematical calculations (SAR, %Na, RSC, PI, KI, and chloroalkaline indices) for better understanding the suitability of ground water for irrigation purposes. The results of saturation index shows that all the water samples were supersaturated to undersaturated with respect to carbonate minerals and undersaturated with respect to sulphate and chloride minerals. According to USSL diagram, most of the samples fall in the field of C3S1, indicating medium salinity and low sodium water which can be used for almost all types of soil with little danger of exchangeable sodium. Assessment of water samples from various methods indicated that majority of the ground water in the study area is chemically suitable for drinking and agricultural uses.

Assessment of Real World On-Road Vehicle Emissions under Dynamic Urban Traffic Conditions in Delhi

Urban transport plays an important role in city development and is one of the major sources of environmental pollution. With a view to understand the relationship between the vehicle emissions and traffic control measures, this paper intends to evaluate the relationship between traffic flow and vehicle emissions using the advanced portable emission measurement system, OEM-2100. Real world on-road data collection of emissions for NOx HC, CO and C02 along with engine parameters such as speed was collected and evaluated during acceleration, deceleration, cruising, and idling under dynamic urban traffic conditions in Delhi. The relationship between vehicle emissions and a commonly used traffic measure, control delay, was investigated. Results showed that emissions were episodic in nature and high emissions rates occurred during acceleration, while vehicle emissions were low when the vehicle was idling. Further emission rates of NOx, HC, CO, and CO2 during delay events were significantly higher than during non-delay events.

Adsorption of Hg(II) from Aqueous Solution Using Adulsa (Justicia adhatoda) Leaves Powder: Kinetic and Equilibrium Studies

The ability of Adulsa leaves powder (ALP) to adsorb Hg(II) from aqueous solutions has been investigated through batch experiments. The ALP biomass was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The experimental parameters that were investigated in this study included pH, adsorbent dosage, and effect of contact time along with initial metal ion concentration. The adsorption process was relatively fast, and equilibrium was achieved after 40 min of contact time. The maximum removal of Hg(II), 97.5% was observed at pH 6. The adsorption data were correlated with Langmuir, Freundlich, and Temkin isotherms. Isotherms results were amply fitted by the Langmuir model determining a monolayer maximum adsorption capacity () of ALP biomass equal to 107.5 mg g−1 and suggesting a functional group-limited sorption process. The kinetic process of Hg(II) adsorption onto ALP biomass was tested by applying pseudofirst-order, pseudosecond-order, Elovich, and intraparticle-diffusion models to correlate the experimental data and to determine the kinetic parameters. It was found that the pseudosecond order kinetic model for Hg(II) adsorption fitted very well. The rate determining step is described by intraparticle diffusion model. These studies considered the possibility of using Adulsa plant leaves biomass as an inexpensive, efficient, and environmentally safe adsorbent for the treatment of Hg(II) contaminated wastewaters.

Detection of Atrazine and Simazine in Ground Water of Delhi using High Performance Liquid Chromatography with Ultraviolet Detector

Herbicide usage has increased dramatically during the last two decades coinciding with the change in farming practices and increasingly intensive agriculture. This study thus assesses herbicide occurrence in the ground water of Delhi i.e. Atrazine and Simazine herbicide. Liquid-liquid extraction with dichloromethane and methanol as extracting solvents were used. These extracted herbicides were separated and quantified by High Performance Liquid Chromatography (HPLC) with ultraviolet detector. The excellent results were achieved with spiked recoveries of 96.8% and 84.6 % for atrazine and simazine respectively. Analysis shows that the concentration of simazine was higher as compared to atrazine. The results obtained were compared with WHO limit of 0.002 mg/l and USEPA limit of 0.003 mg/l for Atrazine and 0.004 mg/l for Simazine. Highest concentration of atrazine was recorded in the north region of Delhi. Sample from the central Delhi did not reveal contamination from any of the herbicides being monitored. The results indicate that there is need for further work to identify sources and fate of herbicide contaminations. The findings of our investigation contribute to the knowledge of the extent of pollution in the groundwater of Delhi.

Hydro-chemical Survey of Groundwater of Delhi, India

The physicochemical parameters and trace metal contents of water samples from Delhi were assessed. A total of 20 water samples were collected from boring, tube well and hand pump and analyzed for the various physicochemical parameters like pH, conductivity, total dissolved solid, total alkalinity, Ca2

Effect of length and diameter on stress distribution pattern of INDIDENT dental implants by finite element analysis

Context: Dental implants are subjected to a variety of loads when placed in function. The implant dimensions influence the magnitude and profile of stresses within the bone. The greater the magnitude of stress applied to a dental implant system the greater the difference in strain between the implant material and bone. An optimum stress profile is required in order to maintain a strong and healthy bone. Materials and Methods: The design efficacy of the Indigenous titanium Dental implant INDIDENT developed by INMAS was studied using finite element stress analysis. Abacus software has been chosen for the analysis and the models are constructed as three-dimensional Solid models. The boundary conditions for each case are same. The amount of load applied is equal for all the cases as 100 N. The study involved the modeling of mandible and the dental implant meshed together. The stress generated was calculated by Finite element method using Abacus software. The different parameters used in this study for FEA simulation were stresses developed due to variation in length and diameter variation. Results and conclusion: The results indicated that the stress concentration and distribution was not effected by the length variation of the Implants. Stress concentration was same at the neck of hole and which can be reduced after suitable chamfering of the hole. The stress distribution on the effect of diameter variation indicates that if the diameter of implant was increased the contact surface also increases and simultaneously stress pattern was reduced.

A Novel Ion-Selective Electrode of Polythiophene Based on Surfactant-Assisted Dilute Polymerization Method

Polythiophene (PTh) nanoparticles were synthesized by cationic surfactant assisted dilute polymerization method using FeCl3 as oxidant in an anhydrous medium. The physical characterizations of the synthesized PTh nanoparticles were studied by FT-IR and UV-Visible spectroscopy, XRD, SEM and EDX. The synthesized PTh nanoparticles were used for the first time to fabricate ion-selective membrane electrode. The experimental results herein concern a novel ion-selective electrode manufactured with an inner solid contact based on PTh nanoparticles. The electrode exhibited a good Nernstian response of 30.2 mV/decade of Mn2+ concentration over an ample concentration range (1.0×10−6−1.0×10−1 mol L−1 , with a detection limit of 1.0×10−6 mol L−1. The membrane electrode showed a very fast response time of 45 s and could be operated well in the pH range 3–7. The selectivity coefficients were determined by the mixed-solution method which revealed that the electrode was selective in the presence of interfering cations. The material was used as electroactive component for the construction of an ion-selective membrane electrode. The membrane electrode was mechanically stable, having wide dynamic range, with quick response time and could be operated for at least 5 months without any considerable divergence in the potential response characteristics. The electrode was used satisfactorily act as indicator electrode during the potentiometric titration of Mn2+ ions with EDTA.

Physico-chemical characteristics of Borewells water of Kolar road area of Bhopal city

Physico-chemical parameters affect directly or indirectly the water quality of bore-wells. Analysis of groundwater was done in monsoon season for one year 2004-05. Two readings of samples observed and analysed to assess the water quality with parameters like temperature, pH, electrical conductivity, Free CO 2 , chloride, total alkalinity, total hardness, Ca-H, Mg-H, D.O., B.O.D., C.O.D., nitrate, sulphate and MPN (Most probable number of bacteria) were analysed during 2004-05. Most of the parameters are found well within the permissible limits as prescribed by WHO (1978). The study is very important and significant for hygienic point of view.