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51.
MH Saidi 《Canadian Metallurgical Quarterly》1997,176(2):492-493
Successful treatment of a severe haemoptysis with microcoil embolization in an en block double-lung transplanted patient is described. A 53 year old woman with advanced bronchiolitis obliterans syndrome experienced severe haemoptysis 26 months after an en bloc double-lung transplantation with direct bronchial artery revascularization using the left internal mammary artery. Bronchoscopy showed that the haemoptysis originated from the lingula. Only two months after the transplant, left internal mammary arteriograms revealed proliferation and enlargement of the bronchial arteries in the lingula. The early occurrence of the vascular malformation indicated a pre-existing bronchiectasis in the donor lung, possibly due to tobacco smoking. After uncomplicated microcoil embolization of the left internal mammary artery, the patient experienced no further episodes of haemoptysis. Microcoil embolization can be used successfully to treat massive haemoptysis related to proliferated and enlarged bronchial arteries in transplanted lungs with bronchial artery revascularization. 相似文献
52.
E Matasha T Ntembelea P Mayaud W Saidi J Todd B Mujaya L Tendo-Wambua 《Canadian Metallurgical Quarterly》1998,10(5):571-582
A cross-sectional questionnaire survey was conducted among 892 randomly selected pupils, aged 12 and above, attending 18 primary schools (PS) and five secondary schools (SS) in four communities of Mwanza Region in Tanzania. The goals were to assess the level of knowledge adolescents have about sexual and reproductive health (SRH), to assess the magnitude of SRH problems and to help design appropriate interventions. Median age of respondents was 15 years (range 12-20 years) and 14 years (range 12-19 years) for PS boys and girls, respectively, and 19 years (range 16-24 years) and 17 years (range 14-19 years) for SS boys and girls. Eighty per cent of PS boys and 68% of PS girls were already sexually active; the corresponding figures were 89% for SS boys and 48% for SS girls. Vaginal sex was the most common first sexual act reported by SS pupils, but 40% of PS pupils reported orogenital sex and 9% of PS pupils reported anal sex as their first sexual act. Almost half of PS girls have had sex with adults, including teachers and relatives. 'Forced sex' was reported by nearly half of PS and SS girls. Fourteen per cent of PS girls had already been pregnant, and over half of these pregnancies ended in illegally induced abortions. Despite a rather high (30%) lifetime rate of condom use, 33% and 25% of PS boys and girls, respectively, reported past experience of sexually transmitted diseases (STDs). STD rates were lower among SS pupils who had a better knowledge of STDs/HIV and fertility issues and reported higher condom use. The survey demonstrated the great vulnerability of school-going adolescents of Mwanza Region to consequences of sexual intercourse. The response should urgently come in the from of comprehensive adolescent SRH programmes. 相似文献
53.
Norshahirah Mohamad Saidi Hong Ming Ng Fatin Saiha Omar Shahid Bashir K. Ramesh S. Ramesh 《应用聚合物科学杂志》2019,136(32):47810
New gel polymer electrolytes (GPEs) were prepared via the blending of a polyacrylonitrile polymer and a poly(1-vinyl pyrrolidone-co-vinyl acetate) copolymer. The sodium iodide (NaI) salt concentration was varied for each GPE sample. From ionic conductivity (σ) studies, we observed that the sample with a 40 wt % NaI salt content (N40) showed the highest σ of 3.54 × 10−3 ± 0.05 S/cm at room temperature, and all of the GPE samples obeyed Arrhenius behavior. The dielectric properties of the GPE samples were also analyzed to study the electrical polarization of the materials. The developed GPE samples were also characterized with X-ray diffraction and Fourier transform infrared spectroscopy. We also then used the developed GPE samples for the fabrication of dye-sensitized solar cells by sandwiching them between a photoanode and Pt counter electrode for photovoltaic studies. The highest photovoltaic performance was achieved by N40, with an efficiency of 3.04%. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47810. 相似文献
54.
Hamza Saidi Walid Aloui Abdelaziz Bouazizi 《Journal of Materials Science: Materials in Electronics》2018,29(21):18051-18058
The electrical proprieties of poly (3-hexylthiophene): Silicon nanowires (P3HT: SiNWs) nanocomposite was investigated by impedance spectroscopy technique. The effect of bias voltage under and without illumination was discussed. Indeed, the imaginary part of the impedance shows a high relaxation frequency related to Maxwell–Wagner–Sillars (MWS) polarization. The relaxation time was found in the range of ms and it was shifted towards high frequency with increasing the bias voltage especially at 0.6 V At bias voltage equal to Vth and under illumination, the conductivity increases because the trapped charges acquire the necessary energy to escape from the interface and the hopping time found was reduced. This indicates a change of the conduction mechanism. The Cole–Cole diagram was excellently fitted through an equivalent circuit including a chemical capacitance Cµ, a contact electrical resistance Rs and recombination resistance Rp. 相似文献
55.
H. Ferhati A. Bendjerad F. Djeffal A. Benhaya A. Saidi 《Ceramics International》2021,47(11):15703-15709
High-performance multispectral photodetectors (PDs) are highly attractive for the emerging optoelectronic applications. In this work, a new broadband PD based on p-NiO/Ag/n-ITO heterostructure was fabricated by RF magnetron sputtering technique at room temperature. The tri-layered structure offering multispectral detection property was first identified using theoretical calculations based on combined FDTD and Particle Swarm Optimization (PSO) techniques. The crystal structure of the elaborated sensor was analyzed using X-ray diffraction (XRD) method. The device optical properties were investigated by UV–Vis–NIR spectroscopy. The NiO/Ag/ITO heterostructured PD shows a high average absorbance of 63% over a wide spectrum range of [200 nm–1100nm]. Compared with NiO and ITO thin-films, the performances of the heterostructured device are considerably enhanced. It was found that the prepared PD with NiO/Ag/ITO heterostructure merges the benefits of multispectral photodetection with reduced optical losses and efficient transfer of photo-induced carrier. The device demonstrated a high ION/IOFF ratio of 78 dB and an enhanced responsivity under UV, visible and NIR lights (171 mA/W at 365 nm, 67 mA/W at 550 nm and 93 mA/W at 850 nm). The broadband photodetection property enabled by the optimized NiO/Ag/ITO heterostructure opens a new route for the elaboration of low-cost devices that can offer multiple sensing purposes, which are highly suitable for optoelectronic applications. 相似文献
56.
57.
Metidji Nadia Bacha Nacer Eddine Younes Abderrahmane Saidi Djaffar 《Powder Metallurgy and Metal Ceramics》2020,59(3-4):160-170
Powder Metallurgy and Metal Ceramics - Recent research on nanocrystalline FeAl alloys has shown that these alloys are of high importance due to their promising structural and mechanical properties,... 相似文献
58.
Marwa Saidi Olfa Mannai Houcemeddine Hermassi Rhouma Rhouma Safya Belghith 《成像科学杂志》2019,67(5):237-253
In this work, we propose a new adaptive chaotic steganographic method based on the Discrete Cosine Transform (DCT) and a reversible mapping function. The mapping function is used to map the secret bits into their corresponding symbols. This mapping technique has to preserve the same dynamics, properties and distribution of the original DCT coefficients. The novelty of our approach is based on the adaptive selection phase of embedding spots. This selection is established through a blindness condition which is applied over each image of the database. The proposed embedding scheme within the middle DCT coefficients shows lower probability of detection and higher flexibility in extraction. We evaluate the detection of our method using the Ensemble Classifiers and a set of frequency and spatial domain feature extractors such as the Spatial domain Rich Model (SRM) features, Chen et al.'s 486-dimensional both inter- and intra-block Markov-based features and Liu's 216-dimensional adaptive steganography-based features. 相似文献
59.
This paper proposes a genetic algorithms (GA) optimization technique applied to power system stabilizer (PSS) for adapt a robust H2 control based on linear quadratic controller (LQ) and Kalman Filter applied on automatic excitation control of powerful synchronous generators, to improve stability and robustness of power system type single machine connected to an infinite bus system (SMIB). Adaptation technique proposed of the robust H2 control with the various electrical and mechanical parametric variations based on the optimization of the PSS parameters. The genetic algorithms is a search technique based on the mechanisms of natural selection of a genetic and evolution. This optimization technique is more used in the field of control for solve optimal choice problem of regulators parameters. The integration of GA to robust H2 control with robustness test (electrical and mechanical parameters variations of the synchronous machine) show considerable improvements in dynamics performances, robustness stability and good adaptation of the robust H2-PSS parameters under uncertain constraints. This present study was performed using our realized Graphical User Interface (GUI) developed under MATLAB. 相似文献
60.
The simultaneous radiation grafting of styrene onto poly(tetrafluoroethylene‐co‐hexafluoropropylene) (FEP) films was studied at room temperature. The effects of grafting conditions (type of solvent, irradiation dose, dose rate, and monomer concentration) were investigated. The degree of grafting was found to be dependent on the investigated grafting conditions. The dependence of the initial rate of grafting on the dose rate and the monomer concentration was found to be of 0.5 and 1.3 orders, respectively. The results suggest that grafting proceeds by the so‐called front mechanism in which the grafting front starts at the surface of the film and moves internally toward the middle of the film by successive diffusion of styrene through the grafted layers. Some selected properties of the grafted films were evaluated in correlation with the degree of grafting. We found that the grafted FEP films possess good mechanical stability, which encourages their use for the preparation of proton exchange membranes. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 220–227, 2000 相似文献