Influence of the method and degree of milling on the rate of milling and leaching of industrial alumina

Conclusions An investigation was made of the influence of the method and degree of milling on the time required to obtain a given mean particle size, and on the leaching of refired industrial alumina.It was found that much more time is required for milling of alumina in a ball mill than in a vibrational mill, the more so, the higher the temperature of the preliminary firing of the alumina. At the same time, the mean surface diameter of the powder increases, together with the content of grains of radius greater than 5, while the content of grains of radius less than 2, which is important to ensure good properties of the fired ceramic, decreases.During milling in a ball mill, the amount of ground iron is increased considerably compared with the amount during vibrational milling to the same particle size of the alumina.Leaching of alumina after milling in a ball mill is less satisfactory than after milling in a vibrational mill. As a result, the Al₂O₃ content in the washed material is decreased and the amount of Na₂O, Fe₂O₃, and other impurities is increased.Translated from Ogneupory, No. 1, pp. 43–50, January, 1969.     

Surveillance of Drinking Water Quality for Safe Water Supply—A Case Study from Shillong,India

To ascertain the quality of drinking water being supplied and maintained, it is necessary to conduct water quality surveillance for evolving suitable strategy for future planning. In the present investigation, water quality was monitored in treatment plants, service reservoirs, and at consumer ends in three seasons to assess the baseline water quality status at Shillong in Meghalaya. There are three water treatment plants at Shillong namely Umkhen, Mawlai and GSWS with design capacities of 1.5, 3.4 and 34 Million liter per day (MLD) respectively. Each treatment plant is having rapid sand filtration followed by disinfection. The study reveals that the physico-chemical parameters of water quality at consumer end meets Indian drinking water quality standards (BIS 1991) after conventional treatment followed by disinfection, whereas the bacteriological parameters for raw water sources exceed the permissible limit indicating the treatment need for drinking purposes. Throughout year the average feacal coliform contamination at service reservoir and to consumer end were found as 44 to 156 CFU/100 ml which may be attributed to the general management practices for maintenance of service reservoirs and the possibility of en route contamination.     

A comparative study on the metaheuristic-based optimization of skew composite laminates

Engineering with Computers - Plate structures are the integral parts of any maritime engineering platform. With the recent focus on composite structures, the need for optimizing their design and...     

Design and Uncertainty Evaluation of a Strain Measurement System

Strain measurement is very important in various industrial applications as well as different disciplines of science and technology for direct and indirect observations of certain parameters. Designing signal conditioning circuit is always a challenging and important task for satisfactory and reliable performance of a sensor as well as the system. The design and implementation details of a signal conditioning circuit of resistive sensor (strain gauge) for strain measurement are presented in this paper. Also the important aspects in designing a signal conditioning circuit for resistive sensor are presented and a novel method for the measurement of strain is discussed. Quarter bridge configuration with AC voltage excitation is used for the measurement along with the necessary circuitry to get a suitable and measurable output DC voltage. The measurement system is calibrated using a cantilever of stainless steel and the details of calibration are presented in the paper. The uncertainty associated with the measurement system is evaluated.     

Creation of TiN paths on titanium alloy OT4-1 by the use of a laser beam

TiN paths have been created on the surface of the titanium alloy OT4-1 by the use of a laser beam. The results of investigations of structure, phase composition, microhardness and surface roughness of the created TiN paths are given in the paper. The paths created in the work are inhomogenous two-phase mixtures of TiN and -Ti, in which the TiN phase with strong (2 0 0) texture is predominant over the other phase and presents a dendritic structure. © 1998 Chapman & Hall     

Evaluation of Optimal River Training Work Using GA Based Linked Simulation-Optimization Approach

Use of structural measures for controlling a river to minimize its devastating effect and to utilize it for the benefit of mankind is a common practice all over the world. Because of high investment, such measures require prior investigation through model study. As lab based physical model study is very expensive and time consuming, mathematical modeling is generally used for investigating different alternatives of river training works. In this study, a new approach is proposed for deciding appropriate river training measure in a particular reach of a river or channel. In this methodology, an optimization model is linked with the hydrodynamic model for obtaining cost effective combination of groynes which will maintain a user defined flow speed in a pre-decided portion of a river reach. The optimization model is developed using binary coded Genetic Algorithm (GA) and the flow simulation model uses the Beam and Warming scheme for solving the two dimensional (2D) hydrodynamic equations of unsteady flow. The performance of the model is tested by applying the methodology in a rectangular channel for attaining different target speed values at a pre-defined portion of the channel and logical results have been obtained for all the tested scenarios.     

The Effect of Thermal Treatment Modes on the Structure and Corrosion Resistance of Plasma Coatings Made of Alloys Based on Nickel and Iron

Protection of Metals and Physical Chemistry of Surfaces - The structural state and corrosion resistance of the plasma coatings based on iron (FBKh6-2 alloy) and nickel (RW 12496 alloy from Castolin...     

Biobased hyperbranched shape‐memory polyurethanes: Effect of different vegetable oils

Hyperbranched polyurethanes were synthesized from poly(ε‐caprolactone) diol as a macroglycol, butanediol as a chain extender, a monoglyceride of a vegetable oil (Mesua ferrea, castor, and sunflower oils separately) as a biobased chain extender, triethanolamine as a multifunctional moiety, and toluene diisocyanate by a prepolymerization technique with the A₂ + B₃ approach. The structure of the synthesized hyperbranched polyurethanes was characterized by ¹H‐NMR and X‐ray diffraction studies. M. ferrea L. seed‐oil‐based polyurethane showed the highest thermal stability, whereas the castor‐oil‐based one showed the lowest. However, the castor‐oil‐based polyurethane exhibited the highest tensile strength compared to the other vegetable‐oil‐based polyurethanes. All of the vegetable‐oil‐based polyurethanes showed good shape fixity, although the castor‐oil‐based polyurethane showed the highest shape recovery. Thus, the characteristics of the vegetable oil had a prominent role in the control of the ultimate properties, including the shape‐memory behaviors, of the hyperbranched polyurethanes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39579.     

The eventuality of diffusiophoresis and chemical reaction in a flow with variable fluid properties through an upright channel

The quintessence of this article encompasses the effect of diffusiophoresis, chemical reaction, and varying viscosity as well as thermal conductivity on a fully developed dissipative flow through an upright channel. The fluid is electrically conducting undergoing mixed convection. The governing equations, after transfiguring into dimensionless formation, are solved through a numerical procedure for boundary value problems incorporating MATLAB solver. Imperative scrutiny is made to visualize associative impacts of flow parameters, namely, magnetic parameter, the Brinkmann number, the Schmidt number, variable viscosity parameter, variable thermal conductivity parameter, chemical reaction parameter, diffusiophoretic parameter, and particle diffusion parameter, on the flow. The velocity field, the temperature field, the solute concentration field, the particle concentration field, the skin friction, the Nusselt number, the Sherwood number, and the particle concentration gradient are assessed in view of alteration of the aforesaid parameters with the help of visual illustrations in graphical form and tabular form. Solute mass transposition and colloidal particle locomotion are the fresh inclusions to the scrutiny of upright channel flow in light of solving scheme of bvp4c. Chemical reaction engulfs both solute and particle concentration. Growing viscosity hinders the fluid velocity and heats up the flow encouraging interlayer friction.     

Method of grinding as a factor in the rheological and technological properties of alumina suspensions

Conclusions Suspensions of alumina wet-ground and dry-ground in a ball mill are characterized by viscosity changes typical for firm systems with static {ie365-01} and dynamic (Bingham) {ie365-02} fluidity limits.These suspensions are thixotropic; the viscositygh _m of their fully broken up structure is higher and their zeta potential lower than for suspensions of vibro-ground alumina, the explanation being the considerably longer grinding time in a ball mill and the fact that in wet grinding a vigorous interaction proceeds between the solid and liquid phases directly in the grinding process.Alumina wet-ground in a ball mill contains more impurities after washing than alumina dry-ground in a vibro mill. The suspension of the former gives a faster rate of casting but the density and strength of the product are lower.Fired commercial alumina to be used for the production of high-quality dense-sintered refractory corundum ceramics should be dry-ground in a vibratory mill.Translated from Ogneupory, No. 6, pp. 44–51, June, 1977.