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121.
A Modified Method for the Determination of N‐Nitrosodiethanolamine in Coconut Diethanolamide Using HPLC with Dual‐Wavelength UV–Vis Detector 下载免费PDF全文
Ramin Mostafalu Abbas Banaei Mohammad Hadi Riazi Fatemeh Ghorbani 《Journal of surfactants and detergents》2016,19(2):431-435
A simple and novel method based on high‐performance liquid chromatography with dual‐wavelength ultraviolet detection at 234 and 254 nm has been developed for the determination of underivatized N‐nitrosodiethanolamine in coconut diethanolamide. The correlation coefficient obtained shows that the method is correct. 相似文献
122.
Oxidative solution polymerization of aniline hydrochloride onto electrospun nanofibers mats of polylactic acid: Preparation method and characterization 下载免费PDF全文
Mazen Al‐Jallad Yomen Atassi Eskandar Mounif Matthieu Aressy Abbas Tcharkhtchi 《应用聚合物科学杂志》2015,132(11)
In this work, we present the preparation of polylactic acid (PLLA)/polyaniline (PANI) conductive composite nanofibers mats. They are prepared by bulk oxidative solution polymerization of PANI onto electrospun non‐woven fibers mats of PLLA. The PANI ratio in the composite is about 70%w/w. Scanning electron microscopy (SEM) shows that PLLA nanofibers are randomly oriented, beads free with diameters of 186 ± 85 nm, The PLLA/PANI composite nanofibers diameter values are 518 ± 128 nm with a good adherence between PANI and PLLA nanofibers. DSC and XRD measurements reveal an amorphous structure of the electrospun PLLA fibers due to the rapid evaporization of the solvent. FTIR and UV–vis spectra reflect good mutual interactions between PANI and PLLA chains. The DC‐conductivities ( ) far better than other published ones for similar composites prepared by bulk oxidative solution polymerization of PANI onto other electrospun nanofiber mats or with electrospun nanofibers from a solution mixture of PLLA and PANI. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41618. 相似文献
123.
Mohammed Sid Ahmed Houari Samir Benyoucef Ismail Mechab El Abbas Adda Bedia 《热应力杂志》2013,36(4):315-334
The thermoelastic bending analysis of functionally graded sandwich plates using the two-variable refined plate theory is presented in this paper. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variationally consistent, has strong similarity with classical plate theory in many aspects, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. The sandwich plate faces are assumed to have isotropic, two-constituent material distribution through the thickness, and the modulus of elasticity, Poisson's ratio of the faces, and thermal expansion coefficients are assumed to vary according to a power law distribution in terms of the volume fractions of the constituents. The core layer is still homogeneous and made of an isotropic ceramic material. Several kinds of sandwich plates are used taking into account the symmetry of the plate and the thickness of each layer. The influences played by the transverse shear deformation, thermal load, plate aspect ratio, and volume fraction distribution are studied. Numerical results for deflections and stresses of functionally graded metal–ceramic plates are investigated. It can be concluded that the proposed theory is accurate and simple in solving the thermoelastic bending behavior of functionally graded plates. 相似文献
124.
Naveed Abbas Tanzila Saba Amjad Rehman Zahid Mehmood Nadeem Javaid Muhammad Tahir Naseer Ullah Khan Khawaja Tehseen Ahmed Roaider Shah 《Microscopy research and technique》2019,82(7):1198-1214
Malaria is a serious worldwide disease, caused by a bite of a female Anopheles mosquito. The parasite transferred into complex life round in which it is grown and reproduces into the human body. The detection and recognition of Plasmodium species are possible and efficient through a process called staining (Giemsa). The staining process slightly colorizes the red blood cells (RBCs) but highlights Plasmodium parasites, white blood cells and artifacts. Giemsa stains nuclei, chromatin in blue tone and RBCs in pink color. It has been reported in numerous studies that manual microscopy is not a trustworthy screening technique when performed by nonexperts. Malaria parasites host in RBCs when it enters the bloodstream. This paper presents segmentation of Plasmodium parasite from the thin blood smear points on region growing and dynamic convolution based filtering algorithm. After segmentation, malaria parasite classified into four Plasmodium species: Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax, and Plasmodium malaria. The random forest and K‐nearest neighbor are used for classification base on local binary pattern and hue saturation value features. The sensitivity for malaria parasitemia (MP) is 96.75% on training and testing of the proposed approach while specificity is 94.59%. Beside these, the comparisons of the two features are added to the proposed work for classification having sensitivity is 83.60% while having specificity is 94.90% through random forest classifier based on local binary pattern feature. 相似文献
125.
Correct Prediction of the Vibration Behavior of a High Power Ultrasonic Transducer by FEM Simulation
Amir Abdullah Abbas Pak 《The International Journal of Advanced Manufacturing Technology》2008,39(1-2):21-28
This paper presents a study on three types of finite element analyses of high power ultrasonic transducer by using the finite element commercial software called ANSYS. The transducer geometry was treated as a 2D axi- symmetric model, 3D quart and full 3D model. For all of the simulations the modeled transducer was used in modal analysis and harmonic solutions to understand its mechanical behavior and its natural frequency. A comparison was made between each type of modeling and experimental results. This comparison allows the parameters of FEM models to be iteratively adjusted and optimized and also leads to selection of the best modeling type. The achieved FEM results exhibited a remarkably high predictive potential of ANSYS in modeling and simulation and allowed control on the design and on the vibration behavior of the high power ultrasonic transducer. 相似文献
126.
Reservoir operation rules are intended to help an operator so that water releases and storage capacities are in the best interests
of the system objectives. In multi-reservoir systems, a large number of feasible operation policies may exist. System engineering
and optimization techniques can assist in identifying the most desirable of those feasible operation policies. This paper
presents and tests a set of operation rules for a multi-reservoir system, employing a multi-swarm version of particle swarm
optimization (MSPSO) in connection with the well-known HEC-ResPRM simulation model in a parameterization–simulation–optimization
(parameterization SO) approach. To improve the performance of the standard particle swarm optimization algorithm, this paper
incorporates a new strategic mechanism called multi-swarm into the algorithm. Parameters of the rule are estimated by employing a parameterization–simulation–optimization approach,
in which a full-scale simulation model evaluates the objective function value for each trial set of parameter values proposed
with an efficient version of the particle swarm optimization algorithm. The usefulness of the MSPSO in developing reservoir
operation policies is examined by using the existing three-reservoir system of Mica, Libby, and Grand Coulee as part of the
Columbia River Basin development. Results of the rule-based reservoir operation are compared with those of HEC-ResPRM. It
is shown that the real-time operation of the three reservoir system with the proposed approach may significantly outperform
the common implicit stochastic optimization approach. 相似文献
127.
Sobia Noreen Sara Hasan Shazia Akram Ghumman Syed Nasir Abbas Bukhari Bushra Ijaz Huma Hameed Huma Iqbal Afeefa Aslam Mervat Abdelaziz Mohamed Elsherif Shazia Noureen Hasan Ejaz 《International journal of molecular sciences》2022,23(5)
The rapid progression in biomaterial nanotechnology apprehends the potential of non-toxic and potent polysaccharide delivery modules to overcome oral chemotherapeutic challenges. The present study is aimed to design, fabricate and characterize polysaccharide nanoparticles for methotrexate (MTX) delivery. The nanoparticles (NPs) were prepared by Abelmoschus esculentus mucilage (AEM) and chitosan (CS) by the modified coacervation method, followed by ultra-sonification. The NPs showed much better pharmaceutical properties with a spherical shape and smooth surface of 213.4–254.2 nm with PDI ranging between 0.279–0.485 size with entrapment efficiency varying from 42.08 ± 1.2 to 72.23 ± 2.0. The results revealed NPs to possess positive zeta potential and a low polydispersity index (PDI). The in-vitro drug release showed a sustained release of the drug up to 32 h with pH-dependence. Blank AEM -CS NPs showed no in-vivo toxicity for a time duration of 14 days, accompanied by high cytotoxic effects of optimized MTX loaded NPs against MCF-7 and MD-MBA231 cells by MTT assay. In conclusion, the findings advocated the therapeutic potential of AEM/CS NPs as an efficacious tool, offering a new perspective for pH-responsive routing of anticancer drugs with tumor cells as a target. 相似文献
128.
In vitro digestibility of starch from tepary bean, Phaseolus acutifolius var. latifolius, was determined in comparison with tepary bean flour and maize starch. The extent of sample hydrolysis by α-amylase was measured as mg reducing sugar (maltose) released per 100 mg substrate. After 2 h incubation at 37°C, values obtained for tepary starch, tepary flour and maize starch treated in various ways were as follows: raw 8.0, 8.6 and 25.6; freeze dried 2.6, 3.2 and 17.8; autoclaved 7.4, 5.7 and 27.7; cooked (15 min) 81.7, 23.1 and 87.8; resp. Raw tepary starch was more resistant to hydrolysis than maize starch due, perhaps, to differences in granule structure and amylose content. Freeze-drying and autoclaving slightly decreased digestibility of both tepary starch and flour. Cooking greatly increased susceptibility to hydrolysis for each substrate. The rate of increase was reduced after 15 min exposure to enzymes, and no appreciable difference was found between cooked tepary and maize starches. 相似文献
129.
Microarray technology has made it possible to investigate expression levels, and more recently methylation signatures, of thousands of genes simultaneously, in a biological sample. Since more and more data from different biological systems or technological platforms are being generated at an incredible rate, there is an increasing need to develop statistical methods that are applicable to multiple data types and platforms. Motivated by such a need, a flexible finite mixture model that is applicable to methylation, gene expression, and potentially data from other biological systems, is proposed. Two major thrusts of this approach are to allow for a variable number of components in the mixture to capture non-biological variation and small biases, and to use a robust procedure for parameter estimation and probe classification. The method was applied to the analysis of methylation signatures of three breast cancer cell lines. It was also tested on three sets of expression microarray data to study its power and type I error rates. Comparison with a number of existing methods in the literature yielded very encouraging results; lower type I error rates and comparable/better power were achieved based on the limited study. Furthermore, the method also leads to more biologically interpretable results for the three breast cancer cell lines. 相似文献
130.
Maryam Mehrnezhad Abbas Ghaemi Bafghi Ahad Harati Ehsan Toreini 《International Journal of Information Security》2017,16(2):133-149
This paper introduces pictorial intelligent system for human identification (PiSHi), an image-based captcha which uses three human cognitive abilities to distinguish humans from machines. The first is the human ability to easily recognise the image’s upright orientation. The second is the human brain’s ability in recognising a picture’s content when it is only partially visible. And the third is the human ability in unconscious decision making when encountering pictorial challenges. This work models such complicated human patterns in problem solving for the first time. In order to extract these behavioural patterns and save them in a pattern database, we have implemented our own captcha and performed a series of experiments. PiSHi’s interface presents the user with a set of distorted pictures and asks her to click on the upright orientation of all the pictures in any preferred order. Next, it captures the user’s interaction patterns, compares them with the ones saved in the pattern database, and grants her a corresponding credit. Based on this credit, the user either passes or fails the test, and participates in updating the picture database. Our experiments indicate that human users can solve our proposed captcha effectively—with an accuracy of 99.44 %. Besides, our proposed system is secure against several types of attacks including random guessing and reverse image search engines. The results offer the possibility of utilising the identified human behavioural models in practical captchas. 相似文献