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Net buoyant force is a crucial factor affecting the functional performance of clothing for water safety. This study aims to develop an alternative method for measuring the net buoyant force of various buoyant materials such as buoyant fabrics, on a small scale in a more accurate and efficient way than the existing method.

The net buoyant forces of buoyant materials with different thicknesses and forms were determined and compared using three methods. In Method 1, the traditional method involving mathematical calculations was used; Method 2 involved using the buoyancy-measuring device from the study of Jin et al. (2018) and Method 3 involved using an alternative buoyancy-measuring system that simulates the actual situation of using buoyant swimwear by measuring the force needed to submerge the buoyant material in water at a standard depth. The net buoyant forces of 22 buoyant materials were measured and compared to test these three methods. The accuracy, reproducibility, sensitivity and validity of these methods were then statistically compared.

The results obtained with the alternative buoyancy-measuring system had higher accuracy, reproducibility and validity than the results obtained through mathematical calculations. The sensitivity of the buoyancy-measuring system (Methods 2 and 3) was higher than that of the traditional method involving calculations (Method 1).

An alternative method is proposed to measure the net buoyant force of buoyant materials on a small scale with higher accuracy, reproducibility and sensitivity.

The paper presents the results of extensive studies on circuit board solderability comparing wetting balance and IPC test methods through performance in vapour phase and wave soldering operations. The effects on solderability of key parameters are examined and compared with storage times of one year, and accelerated ageing using damp heat, dry heat and steam oxygen. An evaluation is made of tin‐lead alloys from 40/60 to 70/30 in solder coating thicknesses from 0·1 to 1·0 mil.

Reviews a number of contributions to migration analysis. Discusses some of the rudiments of migration modelling before turning attention to specific applications. Pays particular attention to articles which have modelled the interaction between labour and housing markets.

This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by.

The design code of aerostat involving structure, aerostatics, aerodynamics and stability has been developed using MATLAB®. The design code is used to obtain the baseline configuration for a tactical aerostat mission by using the statistical values of the hull fineness ratio and the fin parameters of in-service aerostats. The effect of the design variables that include the hull fineness ratio, fin area and fin position on the aerostat mass and blow-by is determined through sensitivity analysis. The aerostat is optimized with an objective function of minimization of mass for the bounded values of design variables and taking blow-by limit as a constraint.

This study reveals that the simultaneous optimization of the aerostat hull fineness ratio, fin area and fin position results in an improvement in the design. The aerostat design with optimum values of these parameters helps in a reduction in its size and mass without compromising the blow-by limits.

This study has been conducted by keeping the hull shape constant by selecting standard National Physics Laboratory envelope shape. The aerodynamic model used in the design code is based on empirical relationships that can be improved in future studies that can use high fidelity aerodynamic models using CFD based surrogate models.

The previous studies on optimization of aerostats are limited to hull envelope shape only, whereas this paper presents the optimization of the hull and fin together. The optimized configuration obtained has a reduced mass and can operate within the specified blow-by limits.

Aim of the present monograph is the economic analysis of the role of MNEs regarding globalisation and digital economy and in parallel there is a reference and examination of some legal aspects concerning MNEs, cyberspace and e‐commerce as the means of expression of the digital economy. The whole effort of the author is focused on the examination of various aspects of MNEs and their impact upon globalisation and vice versa and how and if we are moving towards a global digital economy.

The current study aims to address the interaction between participating media radiation with thermo-gravitational convection of an electrically conducting fluid enclosed within a tilted enclosure under an externally imposed time-independent uniform magnetic field.

The differentially heated boundaries of the tilted enclosure are considered to be diffuse, gray and the enclosed fluid is assumed to be absorbing, emitting and isotropically scattering. The Navier-Stokes equations, meant for magneto convection are solved using modified MAC method. Gradient dependent consistent hybrid upwind scheme of second order is used for discretization of the convective terms. Discrete ordinate method, with S8 approximation, is used to model radiative transport equation in the presence of radiatively active medium.

Effect of uniform magnetic field with different magnitudes and orientations of cavity has been numerically simulated. The effect of participating media radiation has been investigated for different optical thicknesses, emissivities, scattering albedos and Planks number. The results are provided in both graphical and tabular forms. The flow lines, isotherms bring clarity in the understanding of flow behaviour and heat transfer characteristics.

Despite the idealized nature, the present study is quite essential to understand the cumbersome physics of realistic problem.

Realistic data bank of aerodynamic and stability derivatives is still missing for hybrid buoyant aerial vehicles. Such vehicles take-off and land similar to an aircraft with their partial weight balanced by the aerostatic lift. The purpose of this paper is to use wind tunnel testing for a better understanding of the aerodynamic and static stability behavior of such vehicles.

The effect of wing on the aerodynamic and static stability characteristics of a clean configuration hybrid buoyant is analyzed. The free stream velocity is 20 m/s, and ranges of angle of attack and side slip angle are from −8° to 12° and ±16°, respectively. Data are corrected to account for the effect of strut interference and zero load condition. The maximum blockage of the model with respect to the cross-section area of the test section is about 2.7 per cent.

A hybrid model manufactured by using wood and metal is an optimum solution with less number of parts. The vehicle is statically, longitudinally and directionally stable. Wings designed to fulfill the partial requirement of lift contribute significantly to counter the huge moment generated by the voluminous hull for centre of gravity location ahead of the leading edge of the wing.

There are number of manufacturing constraints for scaling down a model of a hybrid buoyant aerial vehicle configuration. Specially, the thickness of the wing limits the testing envelop of angle of attack and free stream velocity.

The data presented here are a preliminary guide for further work on larger size models. The data may also be used to build and perform flight tests on small full-scale instrumented models and to obtain flight dynamics data.

The estimated aerodynamic and stability derivatives and slopes can be utilized in future for multidisciplinary design.

A number of factors ranging from economic conditions to managerial self‐interest have contributed to today's unprecedented merger boom. But the tide may be turning as the public policy debate over mergers heats up. Most scenarios show a long‐range drop in merger activity. However, the need for an informed, rational national policy on mergers remains.