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TO facilitate airscrew performance calculations an entirely new series of charts have been developed embodying wider use than hitherto of the term solidity ratio. These charts are applicable to airscrews with any number of blades. Whilst the number of blades is incorporated in the solidity ratio no further inclusion has been made of their tip speed effect on the interference velocity through the actuator disc. This effect has been investigated by Lock in conjunction with tip speed losses, but it was felt that its inclusion did not justify the added complication to the charts. In fact it makes their simple presentation impossible. The effect, however, can be incorporated with a correction factor to the power input to the airscrew. This factor is not dealt with in detail in this article and would form the subject‐matter of a separate work.

In recent years little has been published on the mathematical theory of vertical flight, though more intelligent work is being done on the subject by various engineers than, probably, at any previous time. In this and a following article, to be published next month, one of the leading exponents of the helicopter, in a specialised and highly ingenious form, covers the whole field of sustentation, ascent, descent and the thorny problem of stability more completely than has ever hitherto been attempted

A small wind turbine blade was designed and optimized in this research paper. The blade plays an important role, because it is the most important part of the energy absorption system. Consequently, the blade has to be designed carefully to enable to absorb energy with its greatest efficiency. The main objective of this paper is to optimized blade number and selection of tip speed ratio corresponding to the solidity. The power performance of small horizontal axis wind turbines was simulated in detail using blade element momentum methods (BEM). In this paper for wind blade design various factors such as tip loss, hub loss, drag coefficient, and wake were considered. The design process includes the selection of the wind turbine type and the determination of the blade airfoil, twist angle distribution along the radius, and chord length distribution along the radius. A parametric study that will determine if the optimized values of blade twist angle and chord length create the most efficient blade geometry. The 3-bladed, 5-bladed and 7-bladed rotor achieved maximum values of Cp 0.46, 0.5 and 0.48 at the tip speed ratio 7, 5 and 4 respectively. It was observed that using BEM theory, maximum Cp varied with strongly solidity and weakly with the blade number. The studies showed that the power coefficient increases upto blade number B = 5, while the blade number if increased above 5 then the power coefficient decreases at operating pitch angle equal to 3°. Highest Cp would have solidity between 4% to 6% for number of blade 3 and design point tip speed ratio of about "7". Highest Cp would have solidity ranging from 5% to 10% for number of blade 5 and 7 and design point tip speed ratio of about 5 and 4 respectively.

SUMMARY Schlichting's cascade functions are expressed as power series in terms of the blade solidity, which makes it possible to derive analytical expressions for the lift coefficient and velocity distribution of an arbitrary cascade of thin aerofoils for solidities of less than unity under smooth air inlet conditions. It is shown that, within the scope of the assumptions made, the angle of attack for shock‐free inlet conditions must be zero, irrespective of the cascade configuration, and that a symmetrical camber line will then yield the maximum lift coefficient. Expressions for this lift coefficient and for the corresponding velocity distribution are derived in terms of the maximum camber and cascade configuration. The analysis is based on Schlichting's cascade theory, and is intended primarily for application to fan blade design.

The purpose of this paper is to find out whether the financial predictors of failure differ for exporting and non-exporting firms.

The study is based on two samples of French manufacturing micro firms from Amadeus database. Samples of 468 exporting and 1,148 non-exporting firms were divided equally to survived and bankrupted firms. Logistic regression method was used with five financial ratios portraying liquidity, solidity, cash flow sufficiency, profitability and productivity.

The findings suggest that cash flow sufficiency and solidity were important predictors in both firm groups, although the latter was more important in case of exporters. Liquidity was important in case of non-exporters, while profitability in case of exporters. Productivity was not a significant predictor. With these variables, failure of exporters was predicted with a higher accuracy.

This paper contributes to an under-researched area in the failure prediction and international business literature, namely, it outlines whether failure predictors are the same for similar exporting and non-exporting firms. The results indicate that some predictors differ and similar ones can have different importance for exporters and non-exporters.

IN all cases, the estimation of airscrew‐engine performance must start with a clear specification of the primary condition for which the airscrew is to be designed. In the majority of cases up to date this primary design condition has been that the airscrew is to absorb the maximum b.h.p. of the engine at maximum permissible r.p.m. at maximum boost height and maximum aircraft speed. (The aircraft speed is obviously an estimate only, but we may assume for the time being that it is reliable.) Under these conditions the airscrew efficiency is required to be the maximum possible.

THE increase in aeroplane speed, brought about by improved aerodynamic design and higher engine powers, together with the design restriction on airscrew tip speed resulting from efficiency considerations, has reacted on the airscrew performance during take‐off, and has made the take‐off more difficult.

DURING the past five years of accelerated development of the helicopter, the following principal problems have become apparent. The order of their importance is as yet a matter of controversy.

The personality impressions evoked by service environments play a key role in attracting and retaining customers. This paper explores the interior design of service and retail environments, and links the designer perspective with the consumer perspective to assist managers in creating and managing interiors for achieving desired responses.

The authors propose and test a conceptual model that relates types of interior design to consumer impressions of that environment's personality. Two studies establish holistic types of interiors based on design elements and factors with a sample of professionals, and then link those types to generic impressions evoked with consumers.

Store personality relates systematically to five holistic types of interiors. Minimal‐shell interiors score high on unpleasantness, complex‐shell designs score high on enthusiasm, genuineness, and solidity, moderate‐shell interiors generate below‐average impressions of sophistication, genuineness, and solidity, low‐content interiors score high on enthusiasm and sophistication, and high‐content designs score low on enthusiasm, and high on unpleasantness.

This research is limited to wine tasting rooms as an example category. Implications for interior design in general can be drawn from the holistic types of interiors identified and from basic relations to generic dimensions of consumer responses.

The findings reported in this research assist managers in more confidently using interior design for positioning and differentiating servicescapes.

Integrating the designer perspective with the customer perspective is a unique approach yielding taxonomy for servicescape interiors, and a holistic perspective on their links with personality impressions.

Blood cold chain (BCC) represents a system for preserving the blood during its journey from the donor to the ultimate transfusion site. Existing BCCs have many drawbacks related to information transparency and information security. Secured and real-time information sharing in BCC can bring several benefits. The purpose of this paper is to summarise the issues in typical BCCs and to explore the scope of blockchain in the management of BCCs.

Issues in the existing BCCs are identified through a narrative review. To explain the potential of blockchain in mitigating these issues, a blockchain-based traceability solution is demonstrated with respect to a particular BCC scenario. The BCC management system discussed in this study makes use of the Ethereum blockchain’s smart contract feature and internet of things (IoT) technology. The smart contract is written in the solidity programming language and tested and validated using the Remix integrated development environment.

BCCs are concerned with several issues both from technical and non-technical perspectives. Blockchain technology is capable of troubleshooting the issues in the existing BCCs. Combining blockchain and IoT technology enables real-time information sharing among the entities. The demonstration presented in this work depicts how the blockchain-based smart contract can support operations in a typical BCC.

This paper explores the scope of blockchain in BCCs through a demonstration. To get insights into its technical and economical feasibilities, further investigations are needed.

Blockchain-based traceability system presented in this work can be adopted in BCCs to ensure the quality of blood or blood products. Blockchain-based smart contracts can aid the BCCs to achieve a proper balance between blood shortage and outdating.