Silicon (Si)-based materials are sought in different engineering applications including Civil, Mechanical, Chemical, Materials, Energy and Minerals engineering. Silicon and Silicon dioxide are processed extensively in the industries in granular form, for example to develop durable concrete, shock and fracture resistant materials, biological, optical, mechanical and electronic devices which offer significant advantages over existing technologies. Here we focus on the constitutive behaviour of Si-based granular materials under mechanical shearing. In the recent times, it is widely recognised in the literature that the microscopic origin of shear strength in granular assemblies are associated with their ability to establish anisotropic networks (fabrics) comprising strong-force transmitting inter-particle contacts under shear loading. Strong contacts pertain to the relatively small number of contacts carrying greater than the average normal contact force. However, information on how such fabrics evolve in Si-based assemblies under mechanical loading, and their link to bulk shear strength of such assemblies are scarce in the literature. Using discrete element method (DEM), here we present results on how Si-based granular assemblies develop shear strength and their internal fabric structures under bi-axial quasi-static compression loading. Based on the analysis, a simple constitutive relation is presented for the bulk shear strength of the Si-based assemblies relating with their internal fabric anisotropy of the heavily loaded contacts. These findings could help to develop structure-processing property relations of Si-based materials in future, which originate at the microscale.
In this work gold nanoparticles (AuNPs), were prepared. Chemical method (Seed-Growth) was used to prepare it, then doping AuNPs with porous silicon (PS), used silicon wafer p-type to produce (PS) the processes doping achieved by electrochemical etching, the solution etching consist of HF, ethanol and AuNPs suspension, the result UV-visible absorption for AuNPs suspension showed the single peak located at ~(530 – 521) nm that related to SPR, the single peak is confirmed that the NPs present in the suspension is spherical shape and non-aggregated. X-ray diffraction analysis indicated growth AuNPs with PS. compare the PS layer without AuNPs and with AuNPs doped for electrical properties and sensitivity properties we found AuNPs:PS is more
... Show MoreABSTRACT Porous silicon has been produced in this work by photochemical etching process (PC). The irradiation has been achieved using ordinary light source (150250 W) power and (875 nm) wavelength. The influence of various irradiation times and HF concentration on porosity of PSi material was investigated by depending on gravimetric measurements. The I-V and C-V characteristics for CdS/PSi structure have been investigated in this work too.
The research problem identified to impose question followingDoes the abstract style role in the backs of visual attraction in modern textile designs?The research aims to reveal the role of the external design in modern women's textile designs printed, design and develop foundations for practical purposes to achieve visual attraction through abstract style used in the design of modern women's fabricsIn regard to the second quarter, which contained the theoretical framework and previous studies, it was included in the board three sections, the first section included the concept of abstraction, while the second section included in place of attraction and infrastructure design, In regard to the third topic was concerned with the concept of m
... Show MoreThe design of fabrics and fashion is manifested by aesthetic advantages betting with the movement of society in its quest to develop as an independent art in itself that is linked to the values and aesthetic concepts of other arts and what appears in them of intellectual systems calling for renewal and modernity. Which brought about a wide change in public taste, as well as a desire for innovation . Which made fashion an interesting aesthetic phenomenon and taste is always subject to change constantly to comply with the social variables that occur in human life, as the fashion that appears in a certain era of time and takes a great distance from spreading as something new and out of the ordinary is in fact the fruit of the development of
... Show MoreThe Arabic calligraphy, in the early days of Islam, was used for the purpose of decorating the walls of mosques from inside and outside. Hence, this decorative art must be actively involved in enriching the designs of Islamic fabrics and costumes because it has a highly qualified and aesthetically pleasing look and expresses the originality of the Arab spirit. The research is divided into two section: the first section included the following topics: First "A historical overview of the art of decoration in Islamic Arab thought". Second "linear formations of decorative designs, and the subject of intellectual aesthetic taste of the art of decorating. This section tackles two subsections: first "the beauty of thought between the function an
... Show MoreIn this paper, we investigate two stress-strength models (Bounded and Series) in systems reliability based on Generalized Inverse Rayleigh distribution. To obtain some estimates of shrinkage estimators, Bayesian methods under informative and non-informative assumptions are used. For comparison of the presented methods, Monte Carlo simulations based on the Mean squared Error criteria are applied.
This research studies the influence of water source on the compressive strength of high strength concrete. Four types of water source were adopted in both mixing and curing process these are river, tap, well and drainage water (all from Iraq-Diyala governorate). Chemical analysis was carried out for all types of the used water including (pH, total dissolved solids (TDS), Turbidity, chloride, total suspended solid (TSS), and sulfates). Depending on the chemical analysis results, it was found that for all adopted sources the chemical compositions was within the ASTM C 1602/C 1602M-04 limits and can be satisfactorily used in concrete mixtures. Mixture of high strength concrete for compressive strength of (60 MPa) was designed and checked using
... Show MoreA metal-assisted chemical etching process employing p-type silicon wafers with varied etching durations is used to produce silicon nanowires. Silver nanoparticles prepared by chemical deposition are utilized as a catalyst in the formation of silicon nanowires. Images from field emission scanning electron microscopy confirmed that the diameter of SiNWs grows when the etching duration is increased. The photoelectrochemical cell's characteristics were investigated using p-type silicon nanowires as working electrodes. Linear sweep voltammetry (J-V) measurements on p-SiNWs confirmed that photocurrent density rose from 0.20 mA cm-2 to 0.92 mA cm-2 as the etching duration of prepared SiNWs increased from 15 to 30 min. The
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