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71.
EG Daoud M Niebauer WH Kou KC Man L Horwood F Morady SA Strickberger 《Canadian Metallurgical Quarterly》1995,130(2):277-280
Coronary revascularization has been suggested as sole therapy for secondary prevention of sudden cardiac arrest associated with ischemia. The use of implantable defibrillators (ICD) in combination with coronary revascularization for this patient population is unclear. Among 412 consecutive patients receiving an ICD, 23 (6%) were identified as sudden cardiac arrest survivors who were noninducible with programmed stimulation and had unstable angina or ischemia on a functional study; they underwent successful coronary revascularization. During a follow-up of 34 +/- 18 months, 10 (43%) of the 23 patients received ICD shocks (8 +/- 8 per patient, range 1 to 22 shocks), and nine of the 10 patients had syncope/presyncope associated with at least one ICD discharge. Patients with ICD discharges were compared with those without ICD discharges, and no clinical characteristics were statistically different between the two groups. In conclusion, revascularization alone may be inadequate therapy for survivors of sudden cardiac arrest associated with ischemia who are noninducible with programmed stimulation, and clinical variables cannot predict which patients are likely to have recurrent malignant ventricular arrhythmias. 相似文献
72.
M. M. El-Zaidia A. A. Higazy M. A. T. Daoud A. M. Abo-Arayis 《Journal of Materials Science》1992,27(2):307-312
Glasses of the system (ZnO)x–(P2O5)1–x
have been prepared by melting ZnO with anhydrous P2O5 in open crucibles. These glasses had compositions ranging from 20 to 70 mol % ZnO (chemically analysed ZnO mol %). Measurements of the thermal conductivity for the present glass system have been made in the temperature range 305 to 630 K. The thermal conductivity of this glass system is mainly due to lattice thermal vibrations. The thermal conductivity data are found to be fairly sensitive to the ZnO mol % content. It is observed from these data that the present glass system can be divided into three compositional regions. This behaviour is qualitatively explained in terms of changes in glass structure. 相似文献
73.
Block devices such as magnetic disks are nonvolatile data storage devices that transfer data in fixed‐size chunks. They are the main nonvolatile memory that holds the file system, and they are also used in virtual memory mechanisms such swapping and page fault handling. Investigating storage performance issues requires a full insight into the operating system internals. Kernel tracing offers an efficient mechanism to gather information about the storage subsystem at runtime. Still, the tracing output is often huge and difficult to analyze manually. In this paper, we introduce a framework to compute meaningful storage performance metrics from low‐level trace events generated by LTTng. A stateful approach is used to model the state of the storage subsystem. Efficient data structures and algorithms are proposed to offer a reasonable response time, allowing the user to navigate throughout the trace and to retrieve metrics from any time range. The framework includes a visualization system that provides different graphical views that represent the collected information in a convenient way. These views are synchronized together, forming a comprehensive perspective that makes storage performance investigation a much more comfortable task. Different use cases are presented to show the usefulness of the framework in real‐world applications. 相似文献
74.
Mohammad Sharif Daoud Aladdin Ayesh Mustafa Al-Fayoumi Adrian A. Hopgood 《Journal of Network and Systems Management》2014,22(1):23-49
In location-based services (LBSs), the service is provided based on the users’ locations through location determination and mobility realization. Most of the current location prediction research is focused on generalized location models, where the geographic extent is divided into regular-shaped cells. These models are not suitable for certain LBSs where the objectives are to compute and present on-road services. Such techniques are the new Markov-based mobility prediction (NMMP) and prediction location model (PLM) that deal with inner cell structure and different levels of prediction, respectively. The NMMP and PLM techniques suffer from complex computation, accuracy rate regression, and insufficient accuracy. In this paper, a novel cell splitting algorithm is proposed. Also, a new prediction technique is introduced. The cell splitting is universal so it can be applied to all types of cells. Meanwhile, this algorithm is implemented to the Micro cell in parallel with the new prediction technique. The prediction technique, compared with two classic prediction techniques and the experimental results, show the effectiveness and robustness of the new splitting algorithm and prediction technique. 相似文献
75.
Alexandre Campos Moraes Daniel Benevides da Costa Michel Daoud Yacoub 《Wireless Personal Communications》2012,64(1):3-19
Wireless communications systems in a frequency reuse environment are subject to cochannel interference. In order to improve
the system performance, diversity techniques are deployed. Among the practical diversity schemes used, Equal-Gain Combining
(EGC) appears as a reasonably simple and effective one. Unfortunately, the exact analysis of the outage probability of EGC
receivers is rather intricate for it involves the evaluation of multifold nested integrals. It becomes mathematically intractable
with the increase of the number of diversity branches and/or interferers. For example, for N
B
diversity branches and N
I
arbitrary independent cochannel interferers, the exact formulation using the convolutional approach requires 2 + N
B
+ (N
B
× N
I
) nested integrals, which, very quickly, and for any practical system, turns out to be mathematically intractable. In this
paper, we propose accurate approximate formulations for this problem, whose results are practically indistinguishable from
the exact solution. In our model, the system is composed by N
B
branches and N
I
interferers so that the desired signals are coherently summed, whereas the interfering signals are incoherently summed at
the EGC receiver. Three sets of fading scenarios, namely α-μ , κ-μ, and η-μ, are investigated. The proposed approach is indeed flexible and accommodates a variety of mixed fading scenarios for desired
and interfering signals. 相似文献
76.
Microbial Quality of Industrial Liquid Egg White: Assumptions on Spoiling Issues in Egg‐Based Chilled Desserts 下载免费PDF全文
Clarisse Techer Amina Daoud Marie‐Noëlle Madec Michel Gautier Sophie Jan Florence Baron 《Journal of food science》2015,80(2):M389-M398
As a 1st step, this study aimed at investigating the microbial quality of liquid egg white in a French egg processing company. Thirty raw and 33 pasteurized liquid egg white samples were analyzed. Pasteurization was globally found efficient on mesophilic contaminants (1.7 ± 1.6 and 0.8 ± 0.9 log CFU/mL in raw and pasteurized samples, respectively), including for the control of Salmonella. However, Gram‐positive enterococci were still detected in the pasteurized samples. As a 2nd step, a representative bacterial collection was built for exploring the spoilage issue in egg‐based chilled desserts. Custard cream was chosen as growth medium since this food is widely used for the production of French chilled desserts. All of the 166 isolates of the bacterial collection were shown to be able to grow and to induce spoilage of the custard cream at refrigeration temperature (10 °C). Several spoilage types were highlighted in the custard cream, on the basis of changes regarding pH, consistency, production of holes or gas. As a 3rd step, bacterial enzymatic activities were explored on custard cream‐based agar media. The bacterial collection was reduced to 43 isolates, based on further selection regarding the genera and the spoilage types previously highlighted. Albeit to different degrees, all these isolates were able to produce proteases. A large part of these isolates also expressed lipolytic and amylolytic activities. This study emphasizes the need to control egg white contamination and especially with Gram‐positive heat‐resistant Enterococi, in order to guarantee the shelf life of egg‐based chilled desserts. 相似文献
77.
78.
This paper describes the physical models behind the various fading distributions applicable in wireless-communications systems, and presents the probability density functions, both for the signal envelope and for the power of the mobile radio signal. It addresses the problem of co-channel interference in terms of its mean value, for macrocellular and microcellular structures, and illustrates how the outage probability is influenced by a series of factors such as reuse pattern, modulation scheme, traffic load, and others 相似文献
79.
Adel Aschi Abdelhafidh Gharbi Mohamed Daoud Roger Douillard Patrick Calmettes 《Polymer International》2007,56(5):606-612
Structures of β‐casein formed in water with various concentrations of guanidine hydrochloride (GdmCl) were studied by small‐angle neutron scattering (SANS). A transition in structure and properties of the protein seems to occur around a GdmCl concentration of 1.2 mol L?1. The data are interpreted assuming that the protein molecules behave like multi‐block copolymers with alternating hydrophilic and hydrophobic sequences. Below the transition, the protein structure is still native and has a fractal dimension larger than that beyond the transition where the β‐casein has the feature of a three‐dimensional excluded‐volume coil. A possible interpretation of these results is that the presence of salt increases the value of the critical micelle concentration. This allows a comparison of the structure of β‐casein and synthetic macromolecules. We find that, although the protein is short, excluded‐volume interactions between monomers are present, and that the structure of β‐casein is very similar to what was found in dilute solutions of linear polymers in a good solvent. Thus, it is reasonable to assume that above the critical salt concentration, the protein is completely isolated, whereas below, some structure remains present. Copyright © 2006 Society of Chemical Industry 相似文献
80.
Virgin olive oil (VOO) production in Tunisia: The commercial potential of the major olive varieties from the arid Tataouine zone 总被引:1,自引:0,他引:1
The commercial potential of olive oils from three consecutive crop years, derived from the main autochthonous olive varieties Chemlali Tataouine, Fakhari Douirat, Zarrazi Douirat and Dhokar Douirat grown in the arid region of Tataounine (Tunisia) was examined with regards to stability and nutrition aspects. Several characteristics such as fatty acid composition, the extremely high phenol-type antioxidant content, and the low levels of green pigments suggested that these oils, the only fat source for the local people, are of promising composition. Efforts to develop commercial products from these varieties could improve antioxidant intake of the local population. The introduction of Good Manufacturing Practices is a prerequisite so that the quality observed for oils obtained by an Abencor system to be achieved also in real life. This can be feasible through appropriate oleoculture, which is often the only viable agricultural activity in remote arid regions such as Tataouine. 相似文献