The effect of flower-like tatania towards characteristics and performance of polysulfone mixed matrix membrane

For ages, the polymeric membrane such as PSf is widely used in liquid separation for various application as the polymer itself offer versatile and attractive properties. However, due to strong hydrophobic nature of PSf property that create serious fouling problem to most of the separation process, thus modification of membrane by integrating strong hydrophilic particles is always practically used among industries and researchers. In this research, the effect of FLT as an additive in the PSf membrane was investigated. With consideration of the FLT that offer larger specific surface area as compared to ST that able to generate better performances and properties of polymer MMM. In this work, the polymer MMM of PSf/FLT and PSf/ST membranes were prepared via phase inversion method at five different concentrations of additive. Membrane characterization involved several observations such as cross-section area, particle distribution, surface roughness, hydrophilicity property, mean pore size, mechanical strength and porosity. Meanwhile, membrane performances were evaluated in terms of HA rejection, PWF, antifouling, antibacterial activity and photocatalytic properties based on self-cleaning antifouling efficiency. From the result, the addition of FLT was strongly influenced overall structure and characteristics of the membrane compared to ST. With a larger surface area of FLT and homogenous distribution inside membrane structure have resulted in better hydrophilicity effect thus improved the membrane performances. The PWF result was increased from 61.33 L/m2h to 137.81 L/m2h for PSf/ST and 155.46 L/m2h for PSf/FLT as increased additive to 3 wt%. Same results were obtained by rejection analysis where the PSf/FLT membrane able to reject more than 96% of HA and improved antifouling and self-cleaning efficiency. It is clearly shown that the present of higher specific surface area of FLT has improved overall characteristics and performances of the membrane compared to ST especially at 3 wt% of concentration

A Comparison of CDMA and Frequency Hopping in a Cellular Environment

This paper compares the performances of direct sequence code division multiple access (CDMA) and frequency hopping (FH) schemes in a cellular multiuser environment. The multiuser channel model incorporates the effects of propagation, frequency selective fading, and interference among users in the presence of a constrained system bandwidth. This channel model is applicable for cellular mobile communications, as well as other forms of personal communications. The CDMA and FH systems are compared using BPSK modulation. The main point of contrast between these systems is that the orthogonal hopping patterns in a FH system result in a decreased additive interference power, however the frequency spreading nature of CDMA results in the ability to combat fading. An information theoretic analysis is presented, which shows that system capacities are far above the performances achieved using simple coding scheme

Semi-parametric regression: Efficiency gains from modeling the nonparametric part

It is widely admitted that structured nonparametric modeling that circumvents the curse of dimensionality is important in nonparametric estimation. In this paper we show that the same holds for semi-parametric estimation. We argue that estimation of the parametric component of a semi-parametric model can be improved essentially when more structure is put into the nonparametric part of the model. We illustrate this for the partially linear model, and investigate efficiency gains when the nonparametric part of the model has an additive structure. We present the semi-parametric Fisher information bound for estimating the parametric part of the partially linear additive model and provide semi-parametric efficient estimators for which we use a smooth backfitting technique to deal with the additive nonparametric part. We also present the finite sample performances of the proposed estimators and analyze Boston housing data as an illustration.Comment: Published in at http://dx.doi.org/10.3150/10-BEJ296 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

Fretting Corrosion Behavior of Additive Manufactured and Cryogenic-Machined Ti6Al4V for Biomedical Applications

Metal ion release, caused by synergistic effect of wear and corrosion, is one of the major concerns related to the prostheses lifetime. In this work, samples of additive manufactured Ti6Al4V are machined under dry cutting and cryogenic cooling conditions and their performances in terms of corrosion and fretting corrosion response are investigated. A wet and temperature-controlled apparatus equipped with an electro-chemical cell is designed and set-up in order to evaluate the fretting corrosion effect acting at the interfaces. The obtained results show that the cryogenic machining improves the corrosion and fretting corrosion behavior of the investigated additive manufactured Ti6Al4V

Process operating mode monitoring : switching online the right controller

This paper presents a structure which deals with process operating mode monitoring and allows the control law reconfiguration by switching online the right controller. After a short review of the advances in switching based control systems during the last decade, we introduce our approach based on the definition of operating modes of a plant. The control reconfiguration strategy is achieved by online selection of an adequate controller, in a case of active accommodation. The main contribution lies in settling up the design steps of the multicontroller structure and its accurate integration in the operating mode detection and accommodation loop. Simulation results show the effectiveness of the operating mode detection and accommodation (OMDA) structure for which the design steps propose a method to study the asymptotic stability, switching performances improvement, and the tuning of the multimodel based detector

Development of a multifunctional panel for aerospace use through SLM additive manufacturing

Lattice materials can overcome the need of light and stiff structures in the aerospace industry. The wing leading edge is one of the most critical parts for both on-board subsystem and structure features: it must withstand to the aerodynamic loads and bird-strike, integrating also the anti-ice system functions. Nowadays, this part is made by different components bonded together such as external skin, internal passageways, and feeding tubes. In the present work, a single-piece multifunctional panel made by additive manufacturing will be developed. Optimal design and manufacturing are discussed according to technological constraints, aeronautical performances and sustainability

A statistical reduced-reference method for color image quality assessment

Although color is a fundamental feature of human visual perception, it has been largely unexplored in the reduced-reference (RR) image quality assessment (IQA) schemes. In this paper, we propose a natural scene statistic (NSS) method, which efficiently uses this information. It is based on the statistical deviation between the steerable pyramid coefficients of the reference color image and the degraded one. We propose and analyze the multivariate generalized Gaussian distribution (MGGD) to model the underlying statistics. In order to quantify the degradation, we develop and evaluate two measures based respectively on the Geodesic distance between two MGGDs and on the closed-form of the Kullback Leibler divergence. We performed an extensive evaluation of both metrics in various color spaces (RGB, HSV, CIELAB and YCrCb) using the TID 2008 benchmark and the FRTV Phase I validation process. Experimental results demonstrate the effectiveness of the proposed framework to achieve a good consistency with human visual perception. Furthermore, the best configuration is obtained with CIELAB color space associated to KLD deviation measure

Methodology for the Diagnosis of Hydromechanical Actuation Loops in Aircraft Engines

This document provides a method for on-board monitoring and on-ground diagnosis of a hydromechanical actuation loop such as those found in aircraft engines. First, a complete system analysis is performed to understand its behaviour and determine the main degradation modes. Then, system health indicators are defined and a method for their real time on-board extraction is addressed. Diagnosis is performed on-ground through classification of degradation signatures. To parameterize on-ground treatment, both a reference healthy state of indicators and degradations signatures are needed. The healthy distribution of indicators is obtained from data and a physics-based model is used to simulate degradations, quantify indicators sensibility and construct the signatures database. At last, algorithms are deployed and a statistical validation of the performances is conducted