Dynamics and stability of radiation-driven double ablation front structures.

The dynamics of double ablation front (DAF) structures is studied for planar targets with moderate atomic number ablators. These structures are obtained in hydrodynamic simulations for various materials and laser intensities and are qualitatively characterized during the acceleration stage of the target. The importance of the radiative transport for the DAF dynamics is then demonstrated. Simulated hydrodynamic profiles are compared with a theoretical model, showing the consistency of the model and the relevant parameters for the dynamics description. The stability of DAF structures with respect to two-dimensional perturbations is studied using two different approaches: one considers the assumptions of the theoretical model and the other one a more complete physics. The numerical simulations performed with both approaches demonstrate good agreement of dispersion curve

Variance Analysis and Autocorrelation Function for 2D Fiber Lap Statistical Analysis

This chapter reports on the statistical analysis of 2D fiber lap using variance analysis and autocorrelation function. It begins with a short overview of the nonwoven processes showing the importance of lap and web formation. It then proceeds to describe the theory of the ideal fiber web. The real defects are taken into account based on random irregularity, periodic irregularity, and compound irregularity. To conclude, the chapter highlights the efficiency of this theoretical approach and its application on 2D fibrous material

Fire performances of a marine bulkhead: numerical evaluation of thermomechanical behavior

The fire performances of marine products are assessed with large scale fire resistance tests following dedicated Standards. However, regarding the conditions of such normative tests, orientation studies for research and development purposes are limited. The aim of the present study is now to develop a numerical model to investigate others configurations. Using the fire performance results of a given bulkhead achieved by fire resistance tests, extrapolation of thicknesses, material properties, joint configuration, etc. can be numerically assessed and used to validate or orientate the final configuration to be tested

PREPARATION OF CELLULOSIC FIBERS FROM SUGARCANE FOR TEXTILE USE

6 pagesInternational audienceThe production of natural fibers is not sufficient to accommodate the textile needs of the growing world population. Therefore, textile research is exploring alternative natural resources to produce fibers. Though typically known for its nutritional use, the sugarcane can also be used for textile production because of its high fiber content.The aim of our study was to extract fibers from sugarcane and to analyze their mechanical behavior. Cane particles were treated with an alkaline solution in order to get cellulosic fibers. Physical and mechanical characterizations were carried out on these fibers: linear density, fineness, tensile properties, and bending rigidity. Their microstructure was analyzed to better understand their behavior. The results showed a strong influence of extraction parameters on the characteristics of fibers. Depending on these parameters, fibers fineness ranged from 8 to 80 tex, length ranged from 19 to 62 mm, and tenacity ranged from 7 and 25 cN/tex

Investigating The Impact of Ict Developments on the Environment in the Digital Economy and Green Economy in Southeast Asia

Purpose:  This study examines information and communication technology's effects on industry revolution 4 on the environment as an effort to develop a digital economy and a green economy in Southeast Asia that is part of the ASEAN organization.   Design/methodology/approach: We use the variables of growth (GDP), green energy, investment in ICT, and the environmental footprint of Southeast Asia in our study. We use secondary data from the Global Footprint Network and the World Bank with a research period from 1990 to 2020. We apply the ARDL technique to determine the relationship between the variables and their direction of causation.   Findings: The impact of ICT on environmental sustainability did not have a significant impact, meaning that the development of information and communication technology is very feasible to be developed to support the green economy as well as the digital economy. Where the use of green energy has a significant negative impact on the ecological footprint which is getting better for environmental sustainability as well as trade openness. Technology shows that technological developments during the research period are increasingly friendly to the environment.   Research, Practical & Social implications:  This research provides an overview of the economy and the environment and how to develop a green economy   Originality/value:  This study investigates three interrelated sectors, namely digital, environment and econom

Citadel: Enclaves with Strong Microarchitectural Isolation and Secure Shared Memory on a Speculative Out-of-Order Processor

We present Citadel, to our knowledge, the first enclave platform with strong microarchitectural isolation to run realistic secure programs on a speculative out-of-order multicore processor. First, we develop a new hardware mechanism to enable secure shared memory while defending against transient execution attacks by blocking speculative accesses to shared memory. Then, we develop an efficient dynamic cache partitioning scheme, improving both enclaves' and unprotected processes' performance. We conduct an in-depth security analysis and a performance evaluation of our new mechanisms. Finally, we build the hardware and software infrastructure required to run our secure enclaves. Our multicore processor runs on an FPGA and boots untrusted Linux from which users can securely launch and interact with enclaves. We open-source our end-to-end hardware and software infrastructure, hoping to spark more research and bridge the gap between conceptual proposals and FPGA prototypes

Study of new systems concepts for a Titan atmospheric probe

Results of a systems concepts study for a Titan Probe were examined. The key tradeoffs performed are described in detail. Mass breakdown of each Probe subsystem or major element were given. The mission analysis performed to determine compliance with the high altitude sampling and descent time requirements are described. The baseline Descent Module design was derived. The element of the Probe System left on the Carrier after separation were described

Impact of the Bijective Relationship between Single and Bundle Cotton Fiber’s in Cotton Breeding Programs

In this chapter, we focus on the relationship between fibers’ mechanical properties and yarns’ ones by studying their relative behavior and the relationship between single and bundle cotton fibers (respectively, dispositions 1 and 2). For this purpose, three different types of cotton fibers were studied. These cottons were chosen from a list of 12 cottons covering a large panel of varieties and physical properties (maturity, fineness, micronaire, length, tenacity, etc.). Classifications per length classes and linear densities were done in order to have more precision and knowledge of cotton fiber behavior. Modeling the creep behavior of single and bundle fibers will help exploring data for the bijective relationship between the two dispositions. Properties evaluated will include elongation, single fibers and bundle tenacities, work of rupture, and so on. Quality of bundle fibers will be a good tool in predicting spinning performances and thus yarn quality