Subspace intersection method of high resolution bearing estimation in shallow ocean using acoustic vector sensors

Abstract Plane-wave DOA estimation techniques yield biased estimates of source bearing angles in the ocean due to the multimode nature of acoustic propagation in an oceanic waveguide. Bearing estimation using matched ÿeld processing requires either a computationally expensive three-dimensional search or a priori knowledge of the source ranges and depths. A new subspace-based high-resolution bearing estimation technique which does not have any of these drawbacks is presented in this paper. ? 2004 Elsevier B.V. All rights reserved

Development of Eco-Sustainable Silica-Reinforced Natural Hybrid Polymer Composites for Automotive Applications

The increasing demand for eco-friendly materials and technology has made the industry focus on bio-compatible composites. This made the researchers explore the potential of eco-friendly, bio-degradable, and inexpensive banana fibre for automotive applications. This work reports the preparation and testing of banana fibre natural hybrid composite fibres randomly oriented with and without adding silica filler (5–15 wt.%) through a hand lay-up process. The mechanical properties such as tensile modulus, flexural modulus, hardness, impact strength, and water absorption capacity were measured. Composite specimens having a fibre length of 30 mm (15 wt.% of silica) exhibited better mechanical properties. The hardness, tensile, flexural, and impact strength measured were 46.74 HV, 54.71 MPa, 127.94 MPa, and 15.19 kJ/m2. The results showed significant improvement in mechanical properties in silica-reinforced hybrid composite compared to composites without silica filler. The wt.% of banana fibre increases, and the number of free hydroxyls (-OH) groups increases in cellulose, increasing moisture absorption. The pattern in which the composite absorbs the moisture at room temperature is called “Fickian behaviour.” Furthermore, scanning electron microscope (SEM) characterisation studied the interaction between fibre matrix and the distribution of silica reinforcement. This research concludes that bio-composites that exhibit improved mechanical properties are eco-friendly and are found to be suitable for automotive applications that meet present-day requirements

An Experimental and Theoretical Study of the Kinetics of the Reaction between 3-Hydroxy-3-Methyl-2-Butanone and OH radicals

International audienc

Doubled haploid production in onion (Allium cepa L.): from gynogenesis to chromosome doubling

Bulb onion (Allium cepa L.) is an allogamous diploid (2n = 16) important for its culinary uses, nutritional value, and medicinal benefits. Despite its economic importance, onion yields and bulb quality are declining, emphasizing the need for new and improved strategies for maintaining and enhancing overall crop quality. Development of inbred lines in onion through traditional breeding is often difficult due to its biennial life cycle, inbreeding depression, and comparatively high heterozygosities. Moreover, genetic research in onion has been hampered by large nuclear genome size. In this regard, gynogenic doubled haploids promise several advantages over inbred lines in support of onion breeding programs and genetic studies. These include complete homozygosity in doubled haploid lines, reduced DNA methylation, elimination of deleterious alleles, and amenability to genetic analysis. This review focuses on the application of in vitro gynogenesis for producing doubled haploids in onion. Factors influencing haploid induction, methods for inducing chromosome doubling and ploidy assessment, evaluation of haploid progenies and doubled haploid lines, and features of doubled haploids potentially useful in crop improvement and genetic studies, are discussed. We identify four major limitations to the success and efficiency of in vitro gynogenesis in onion and discuss strategies for mitigating the negative impacts they pose. This review may be useful to research programs producing doubled haploids in onion or other Allium species using in vitro gynogenesis