Impact performance of innovative corrugated polystyrene foam for bicycle helmets

Expanded Polystyrene (EPS) is a common material used to manufacture the inner foam liner of a bicycle helmet due to its outstanding energy absorption characteristics and light-weight property. The current research presents a novel corrugated expanded polystyrene (EPS) foam design concept which is used to enhance the impact dissipation of bicycle helmets from the safety standpoint to reduce head injuries and make them lighter. The baseline comparison study under impact for different foam configurations is compared with a conventional EPS foam sample without corrugation. Corrugated foam designs under current investigation are 12.5–20% lighter and provide up to 10% higher energy absorption. The details of the novel manufacturing concept, CPSC 1203 helmet impact tests, high-speed camera study to understand the differences in the failure mechanisms are deliberated in this paper.

Enhanced energy absorption characteristics of novel integrated hybrid honeycomb/polystyrene foam

Expanded Polystyrene (EPS) is commonly used as an inner liner for a bicycle helmet due to its outstanding energy absorption characteristic and light-weight property. The current investigation presents a novel technique to manufacture hybrid EPS/honeycomb structure foam using an integrated manufacturing approach to further enhance the energy dissipation properties for improved safety against head injuries. Different foam designs were analysed under curb-stone impact tests and the failure mechanisms are deliberated. Integrated EPS-honeycomb hybrid liners have shown up to 20% higher energy absorption, with the additional energy being absorbed in associated densification of foam and the elastic buckling features of the honeycomb.

Ghost classes in $${\mathbb {Q}}$$-rank two orthogonal Shimura varieties

In this article, the existence of ghost classes for the Shimura varieties associated to algebraic groups of orthogonal similitudes of signature (2, n) is investigated. We make use of the study of the weights in the mixed Hodge structures associated to the corresponding cohomology spaces and results on the Eisenstein cohomology of the algebraic group of orthogonal similitudes of signature $$(1, n-1)$$ ( 1 , n - 1 ) . For the values of $$n = 4, 5$$ n = 4 , 5 we prove the non-existence of ghost classes for most of the irreducible representations (including most of those with an irregular highest weight). For the rest of the cases, we prove strong restrictions on the possible weights in the space of ghost classes and, in particular, we show that they satisfy the weak middle weight property.

Mechanical and Morphological Analysis of Aluminum Composite Material

Now a days industry focused on a light weight concept of the material. The light weight material also used in a engineering projects. In the light weight material as more useful in a engineering application. So in the work focused on the light weight materials. In this work Al 6061 B4C and Sic composite material. The material compared to the normal material is light weight. also the in this work focused on the wear behavior of the material. In this work mainly focused on the mechanical and Metallurgical properties of sic composites. The objective of the paper is reduce wear and give light weight material. In this paper mechanical and light weight Property discussed. The mechanical and SEM surface also discussed. in this paper compared the different composition and finally got a result of the better composition

Aplikasi Geofoam Sebagai Material Timbunan di Atas Tanah Lunak

Geofoam is a geosintetik material made of Expanded Polystyrene (EPS) and Xtruded Polystyrene (XPS), which has a low weight property which makes geofoam widely used as a lightweight fill material and has been applied in Europe, especially in Eastern Europe. This is a preliminary research that emphasizes on the use of geofoam as a fill material on soft ground through theoretical analysis using Plaxis program. Supporting data used covers data of basic and fill ground taken from specific locations which are planned for subsequent research as a field test. Based on the Plaxis program results, the use of geofoam as a fill material give a higher safety factor value with a smaller deformation compared to laterite soil. This result indicates that the use of geofoam as a fill material can be considered to be applied in the country.

PRESENTATION OF QUANTUM GENERALIZED SCHUR ALGEBRAS

We obtain the explicit generators of the annihilator ideal for the tensor product of any finite dimensional simple module over quantum group [Formula: see text], by using the weight property of ideals in [Formula: see text] when q is not a root of unity. As an application, we give a presentation of quantum generalized Schur algebra.