Development of Forecasting Model for Prediction of Compressive Strength of Foamed Concrete using Density with W/C ratio and S/C ratio by the Application of ANN

This Artificial neural network study presents the prediction model for a cellular foamed concrete. Foamed Concrete is a cementitious material that should consist of a minimum of 20% of foam, which is mechanically entrained using the mechanical generator of foam. Foamed Concrete possesses a cellular microstructure. By which they become a highly air-entrained system having unusual physical and mechanical properties. It is the perfect mixture of cement, water, sand (fine aggregate), and perforated foam. Published information related to the prediction of foamed concrete is limited, and rational guidelines to evaluate the compressive strength of the concrete are not widely available. This study aims to encourage the strength of foamed concrete economically and predict the strength in the compressive form of concrete. A dataset of 153 instances having an input parameter proportion of Density, W/C ratio, & S/C ratio have been taken to predict compressive strength to elevate and expand the precision and accuracy of the foamed concrete. The data has been trained with the help of ANN, in which we conduct a network analysis to forecast the compound’s performance and stability. The deficiency of strength of foamed concrete is to be sorted out with the help of ANN, and the prominent and reliable equation for the compression power is generated. ANN helps to optimize the compressive strength at the time of physical casting of the concrete.

Improvement of automatic surfacing technique under flux at ship propeller shaft repair

During the operation of surfaces in ship propeller shafts they are worn out intensively. To prolong their life there are used at shipyards an automatic surfacing under flux (ASF) which, besides high efficiency is characterized with a considerable share of a basic metal participation in surfacing worsening properties of a deposited layer. The aim of the paper consists in the technology improvement of ship propeller shafts restoration with the aid of ASF and SBM decrease on the basis of complex mechanization and energization of a technological process. The process energization consists in the transfer character control of electrode metal through an arc by geometry and properties of driven rollers at the expense high-frequency extra-axial oscillations of an electrode (EOE) created by a special mechanical generator. The developed ASF technology ensures pad quality meeting requirements of the Register.

Homokinetic Shaft-Coupling Mechanisms via Double Schoenflies-Motion Generators

The paper begins with introducing the 5-dimensional (5D) double Schoenflies-motion (X-X motion) set employing the group product of two 4D X-motion subgroups of displacements. Two families of primitive X-X motion generators are briefly outlined. Then, the geometric constraints for homokinetic transmission via Lie-group-algebraic properties of the displacement set are established. After that, using the described mechanical generators of X-X motion as the basic building cell, we geometrically generate two major families of homokinetic shaft-coupling mechanisms characterized by a subchain with a mechanical generator of 5D X-X motion set of displacement. The obtained constant-velocity shaft couplings (CVSC) are isoconstrained linkages with two parallel shaft axes, which will be less sensitive to manufacture errors. In addition, by means of the reordering method for displacement group compositions, more CVSC mechanisms can be further obtained. The simple or special findings stemming from the proposed general architectures are presented for the potential applications too.

Modeling of Automatic Power Output Prediction for Wind Mechanical Generator

Due to the instability of the output in wind power, there exists some difficulties on wind power merger to electricity grid. The fast forecasting of output of wind power is in favor of reasonable allocation system and increase the possibility of power merger in a large scale. Based on the actual wind power data, this article utilizes the one order differential method to remove data unsteady and obtains the stable data. In view of the ARMA time series, a numerical prediction model of wind power output is established. The results show that the model has good precision and can be used in the production practice.

New Mechanical Generators of Schoenflies Motion Implementing Bennett Linkages

Based on the Bennett 4R chain, we construct a rotating loop by fixing one R axis to the frame and the fixed R becomes a coaxial double R pair. The R pair opposite to the fixed double R is replaced by a spherical S pair which can be equivalent to a (RRR) open chain with non-coplanar intersecting axes. In the (RRR) sub-chain, we choose special axes and derive R|- R|(R(RRR)R chain moving with 2 DoFs. That moving R becomes a coaxial double R with the addition of another rigid body and the obtained chain with hybrid topology generates a 3-dof motion, which is mathematically modeled by a 3D submanifold of a 4D group of X motions. Because of the product closure in an X-motion group, adding an H pair with any pitch and an axis parallel to the fixed R axis leads to a mechanical generator of a 4D X-motion group. Then, parallel arrangement of two generators of the same X motion gives a new parallel generator of X motion, which can be actuated by four fixed R pairs; the two Hs must have distinct pitches. A special design with four collinear actuated axes is revealed too.

Conversaziones and Reception, 1975

Conversaziones were held this year on 8 May and 26 June. At the first conversazione twenty-five exhibits and two films were shown. Frictionless Stirling-cycle engines were demonstrated by the Electronics and Applied Physics Division, U.K.A.E.A., Harwell. Conventional Stirlingcycle engines running at low power levels are extremely inefficient, owing mainly to the sliding friction associated with the pistons and their coupling mechanisms. Two types of frictionless Stirling-cycle engines have been developed at Harwell. In the thermo-mechanical generator, the output piston of such an engine is replaced by a diaphragm coupled to an electrical generator and the displacer piston is spring mounted, out of contact with the cylinder. The two spring/mass systems are coupled by their common fixing point. This self-starting, frictionless Stirling-cycle engine takes up its own resonance frequency when heat is applied, and has an efficiency of 15% at a 25 W output. An operational prototype generator driving a small television set was shown. Fluidyne is a self-excited, freely oscillating Stirling-cycle engine which needs no solid moving parts and consists simply of two U-tubcs partially filled with liquid; three of the four ends of the U-tubes are connected together through a gas-filled space. The Fluidyne engine has potential applications as a simple pump, e.g. in irrigation systems using solar heat and several versions of the system were shown in operation.