The Low-Cost Autogyro

1963 ◽  
Vol 67 (626) ◽  
pp. 111-118
Author(s):  
K. H. Wallis

Autogyro principles and theory are well known and only the practical aspects of design and construction of the smallest of autogyro aircraft will be considered on this occasion. Also, at this stage, it would be inappropriate to be specific about prices of such aircraft owing to the difficulty of estimating production costs. Tare weights, however, may provide some clues as to costs.In the “thirties” the autogyro had been brought to quite a high standard of performance, mainly through the pioneering and development efforts of one man, Senor Juan de la Cierva.During those years many ideas, which would today be regarded as novel, had been tried. Jump-start, pusher engines and tricycle undercarriages are not new.

2010 ◽  
Vol 174 ◽  
pp. 127-131
Author(s):  
Chun Hui Feng ◽  
Quan Xiang Liu

Special printing material and special techniques are used for the purpose of fighting against the piracy of the presswork. But these methods require high standard technology and high production costs. Using digital watermark can guarantee a strong and low cost protection for the presswork. Existing digital watermark algorithms for halftone images are mostly applied to FM (Frequency Modulation) screening and these algorithms usually complete the embedding process by modulating the coefficients of the frequency domain. Such algorithms are relatively complex, and they are easy to lose information so that it will make a lower detection probability. Moreover, in the actual printing process, AM (Amplitude Modulation) screening is the more mature and more widely used method compared with FM screening. The subject of this article is monochrome presswork generated by AM screening. The structure of this article is as follows: The first section uses the principle of HVS (Human Visual System) model to select the area in which the watermark will be embedded. The second section uses different screening threshold matrixes to create the printing dots in the selected area. In this way, a texture of certain direction is formed. The last section uses Fourier Power Spectrum method to detect the texture features of the screened image to complete the detection of the watermark. The result of the experiment shows that this algorithm can generate a digital watermark of good transparency and high detection effectiveness. It combines a unique AM screening approach to complete the embedding process. All the processes do not require any additional equipment, and the embedding and detection process are quite simple.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrea Crosino ◽  
Elisa Moscato ◽  
Marco Blangetti ◽  
Gennaro Carotenuto ◽  
Federica Spina ◽  
...  

AbstractShort chain chitooligosaccharides (COs) are chitin derivative molecules involved in plant-fungus signaling during arbuscular mycorrhizal (AM) interactions. In host plants, COs activate a symbiotic signalling pathway that regulates AM-related gene expression. Furthermore, exogenous CO application was shown to promote AM establishment, with a major interest for agricultural applications of AM fungi as biofertilizers. Currently, the main source of commercial COs is from the shrimp processing industry, but purification costs and environmental concerns limit the convenience of this approach. In an attempt to find a low cost and low impact alternative, this work aimed to isolate, characterize and test the bioactivity of COs from selected strains of phylogenetically distant filamentous fungi: Pleurotus ostreatus, Cunninghamella bertholletiae and Trichoderma viride. Our optimized protocol successfully isolated short chain COs from lyophilized fungal biomass. Fungal COs were more acetylated and displayed a higher biological activity compared to shrimp-derived COs, a feature that—alongside low production costs—opens promising perspectives for the large scale use of COs in agriculture.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2436
Author(s):  
Abubakar Sadiq Mohammed ◽  
Martina Meincken

Low-cost wood–plastic composites (WPCs) were developed from invasive trees and recycled low-density polyethylene. The aim was to produce affordable building materials for low-cost social housing in South Africa. Both raw materials are regarded as waste materials, and the subsequent product development adds value to the resources, while simultaneously reducing the waste stream. The production costs were minimised by utilising the entire biomass of Acacia saligna salvaged from clearing operations without any prior processing, and low-grade recycled low-density polyethylene to make WPCs without any additives. Different biomass/plastic ratios, particle sizes, and press settings were evaluated to determine the optimum processing parameters to obtain WPCs with adequate properties. The water absorption, dimensional stability, modulus of rupture, modulus of elasticity, tensile strength, and tensile moduli were improved at longer press times and higher temperatures for all blending ratios. This has been attributed to the crystallisation of the lignocellulose and thermally induced cross-linking in the polyethylene. An increased biomass ratio and particle size were positively correlated with water absorption and thickness swelling and inversely related with MOR, tensile strength, and density due to an incomplete encapsulation of the biomass by the plastic matrix. This study demonstrates the feasibility of utilising low-grade recycled polyethylene and the whole-tree biomass of A. saligna, without the need for pre-processing and the addition of expensive modifiers, to produce WPCs with properties that satisfy the minimum requirements for interior cladding or ceiling material.


Author(s):  
Chandrasekhar Karra ◽  
Thomas A. Phelps

Abstract The success of any industry in today’s highly competitive market is largely dependent on its ability to produce quality products, quickly and at low cost. Evaluating the effect of a product design on its manufacture is crucial in developing efficient designs. Any potential manufacturing problems detected at this stage can be corrected by modifying the design, leading to shorter product development cycles and lower production costs. This paper presents an algorithm to determine feasible tool approach directions. The algorithm is based on detecting if any part of the object obstructs the tool path. The basis for the algorithm is determining feasible approach directions and clearances around a planar polygonal face. The algorithm is applicable to both protrusions and depressions. The information is useful in performing manufacturability analysis of designs and develop process plans.


1970 ◽  
Vol 185 (1) ◽  
pp. 95-107
Author(s):  
B. H. Croft

The requirements of the modern automotive petrol engine in relation to higher specific power outputs while retaining good driveability and satisfying the impending exhaust emission control regulations, motivated an investigation into the potential of petrol injection. Consideration of the control requirements and accuracy necessary led, at an early stage, to the selection of electronic control on the basis of control capability, long term reliability, relatively low cost and the potential for future development. The fuel system was designed round the electronic control, manifold injection being used instead of direct injection on the basis of simplicity, lower cost and greater installation flexibility. The original system concept has changed only in detail, development effort being applied to the refinement of the system components to achieve a high standard of performance and the facility to apply the system with minimal modification to a wide range of engine types. The system is described in some detail and typical examples of the system performance on vehicles are presented.


2016 ◽  
Vol 7 (2) ◽  
pp. 42
Author(s):  
Aparecida De Fátima Oliveira Silva ◽  
Leila Maria Girondi ◽  
Suellen Jensen Klososki ◽  
Tatiana Colombo Pimentel ◽  
Carlos Eduardo Barão

Cassava bagasse, regarded as an agricultural residue can be used as raw material in the development of new products. Cereal bars are foods that have increasingly gained consumers because of the practical use. The objective of this study was to evaluate the effect of adding cassava bagasse (0, 8 and 25%) on the chemical composition and sensory acceptance of coconut cereal bars with Brazil nuts. Cereal bars with cassava bagasse had higher moisture, protein and carbohydrates (fiber) contents than cereal bars without bagasse, lower ash contents and similar fat content. The addition of cassava bagasse caused a decrease in the acceptance of the cereal bars only in the concentration of 25%, however, the products had hedonic values greater than 7 in a 9-point hedonic scale and acceptability indices higher than 80%, indicating that consumers moderately liked them. It can be concluded that the use of up to 25% cassava bagasse in the cereal bar formulation yields products with improved nutritional value and appropriated consumer acceptance. The addition of cassava bagasse to food products is a good alternative in the use of this byproduct, due to the sensory characteristics of the obtained products and the reduction of production costs, because the cassava bagasse has low cost and increases the production yield.


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