1,052 research outputs found

    Design and Simulation of Worldwide Interoperability for Microwave Access Computer Network for 3×3 Km Universal Sample of Building Campus

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    The aim of this study to design a wireless computer network of a particular network as a large-scale company or university to improve mobility and to let the teachers and students of the university, for example, stay interacted and connected at any time in any campus location or site. Therefore, This study needed to cover the overall area of this campus with efficient wireless coverage that exceeds the university boundaries to maintain wireless signal strength. To do that, the researchers thought that it is very significant to design a Worldwide Interoperability for Microwave Access (WiMax) computer network with the most powerful and advanced hardware component capabilities to full fit teachers’ and students’ requirements of fast net browsing and files’ download. After designing the university campus of computer network, simulation has done by OPNET 14 Modular to determine the WiMax network design parameters. The purpose of the current research is to find if the design of the campus network is efficient or not and also to determine the performance of theimplemented network

    Development and Validation of a Kinetic Model for Enzymatic Hydrolysis Using \u3ci\u3eCandida rugosa\u3c/i\u3e Lipase

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    Biochemical processing involving enzymatic catalysis of hydrolysis reactions of oils and fats must overcome significant technological barriers before the full benefits of the technology can be realized. Owing to their selectivity and mild reaction conditions, lipases are becoming increasingly important as biocatalysts provided that their kinetics and optimum reaction conditions are well-understood. In this study we report on the development and validation of a kinetic model for the degradation of oils using Candida rugosa lipase, from which a better understanding of the influence of different reaction conditions on hydrolysis kinetics is elucidated. Variations of reaction temperature, mixing speed, enzyme loading and substrate concentrations yielded a maximum lipase activity of 25.67 lipase units (LU), and an activation energy of 4.32 Kcal/gmol. Significantly higher enzyme loading at 0.7 mg/ml was achieved, a 169% increase over most recently reported loading by other investigators. Optimum operating ranges for medium pH and substrate concentration were established to be 7.5 to 8.5, and 30 to 55%, respectively. Reported findings mark a significant improvements over previously reported much narrower ranges of 8.0 for pH and 30 to 43% for the substrate concentration under similar experimental conditions. Developed kinetics model closely predicted and matched experimental results, rendering it suitable for biochemical engineering design application

    COMPLEXITY REDUCTION OF CYCLOSTATIONARY SENSING TECHNIQUE USING IMPROVED HYBRID SENSING METHOD

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    In cognitive radio system, the spectrum sensing has a major challenge in needing a sensing method, which has a high detection capability with reduced complexity. In this paper, a low-cost hybrid spectrum sensing method with an optimized detection performance based on energy and cyclostationary detectors is proposed. The method is designed such that at high signal-to-noise ratio SNR values, energy detector is used alone to perform the detection. At low SNR values, cyclostationary detector with reduced complexity may be employed to support the accurate detection. The complexity reduction is done in two ways: through reducing the number of sensing samples used in the autocorrelation process in the time domain and through using the Sliding Discrete Fourier Transform (SDFT) instead of the Fast Fourier Transform (FFT). To evaluate the performance, two versions of the proposed hybrid method are implemented, one with the FFT and the other with the SDFT. The proposed method is simulated for cooperative and non-cooperative scenarios and investigated under a multipath fading channel. Obtained results are evaluated by comparing them with other methods including: cyclostationary feature detection (CFD), energy detector and traditional hybrid. The simulation results show that the proposed method with the FFT and the SDFT successfully reduced the complexity by 20% and 40% respectively, when 60 sensing samples are used with an acceptable degradation in the detection performance. For instance, when Eb/N0 is 0 dB , the probability of the detection of Pd is decreased by 20 % and 10% by the proposed method with the FFT and the SDFT respectively, as compared with the hybrid method existing in the literature

    Relationship between biomarkers of muscle damage and redox status in response to a weightlifting training session: effect of time-of-day

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    The aims of the present study were to: (1) investigate the effect of a weightlifting training session and time-of-day (TOD) upon biological parameters (i.e., oral temperature, hematological, C-reactive protein (CRP), and oxidative stress) and (2) assess their possible link with muscle damage responses. Nine weightlifters (21 ± 0.5 years) performed, in a randomized order, three Olympic-Weightlifting sessions (i.e., at 08:00, 14:00, and 18:00). Blood samples were collected at rest, 3 min and 48 h after each training session. Between pre- and post-training session, ANOVA showed significant increases in oxidative stress markers at the three TODs (p < 0.01) and significant increases for creatine kinase (CK) and lactate dehydrogenase (LDH) only at 08:00 and 18:00 (p < 0.05). At rest, the results showed a significant diurnal variation for the majority of the selected parameters except for malondialdehyde (MDA), total bilirubin, and CRP with higher values observed at 18:00 (p < 0.05). After the training session, given the higher rate of increase during the morning session, these diurnal variations persisted for temperature and WBC (p < 0.01) and were suppressed for CK, LDH, uric acid (UA), catalase, and glutathione peroxidase. The main significant correlations (p < 0.001) were observed between: (1) CK and MDA (r = 0.6) and CK and UA (r = 0.66 and r = 0.82) during the morning and evening training sessions; (2) CK and CRP only during the morning session (r = 0.5); and (3) CRP and WBC during the three training sessions (r = 0.8). In conclusion, the present findings: (1) confirm that the muscle damage responses could be induced by a high level of oxidative stress and (2) suggest to avoid scheduling training sessions in the morning given the higher muscle damage, inflammatory, and oxidative responses at this TOD

    An Experimental Investigation of Mechanical Properties of The Ultra-High Performance Fiber Reinforced Concrete (UHPFRC)

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    Ultra-high performance concrete (UHPC) is a novel relatively construction material exhibiting enhanced mechanical and durability properties, which can lead to economical construction through reducing the cross-sections of structural. A study has been made through this investigation to understand the behavior of Ultra-High-Performance Concrete members with steel and polypropylene fibers. The research included the use of a cement, quartz sand, silica fume , steel fibers, polypropylene, superplasticizers and without using any type of aggregates other than the quartz sand Results show that it is possible to produce UHPFRC using materials that are available at the local markets if they are carefully selected and will achieve a minimum compressive strength of (170.32) MPa and The flexural strengths of (23.54 ) MPa and splitting tensile of( 19.1) MPa at the age of 28 days. This can be seen the experimental results showed a significant improvement in the residual mechanical properties of the concretes which contain the mix of fibers compared to concrete mixes without fibers. Keywords: Polypropylene  Fibers; Steel Fibers; Ultra High Performance Concrete DOI: 10.7176/CER/11-12-01 Publication date: December 31st 201

    Elevation of serum soluble E-selectin and VCAM-1 in severe asthma.

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    OBJECTIVE: To investigate the significance of circulating adhesion molecules associated with leucocyte-endothelial cell interactions in asthma, serum levels of soluble E (sE)-selectin, soluble P (sP)-selectin, soluble L (sL)-selectin, and soluble vascular cell adhesion molecule-1 (sVCAM-1) were measured in mild, moderate and severe asthma. METHOD: Serum levels of sE-selectin, sP-selectin, sL-selectin, and sVCAM-1 were measured in 32 women with asthma and 30 healthy donors using an enzyme-linked immunosorbent assay method. Twenty patients were suffering from severe asthma, and 12 from mild/moderate asthma. RESULTS: Serum sE-selectin and sVCAM-1 levels from patients with asthma were significantly higher than those observed in healthy donors (p < 0.01). The levels of sP-selectin were the same as those of controls. The level of sE-selectin exhibited an important increase in the severe asthmatic patients compared with mild/moderate asthma (p < 0.01). The sVCAM-1 level was increased in severe asthma when compared with healthy controls. There was no correlation between the levels of soluble selectins and the age of the patients. A significant correlation was found between sE-selectin and sVCAM-1 levels. CONCLUSION: These data indicate that circulating soluble forms of the selectins may have different kinetics during the clinical course of asthma, suggesting that they may reflect different inflammatory pathways in severe asthma. Both sVCAM-1 and sE-selectin may be useful immunological markers for monitoring disease activity in asthma

    Diverse auto-curriculum is critical for successful real-world multiagent learning systems

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    Multiagent reinforcement learning (MARL) has achieved a remarkable amount of success in solving various types of video games. A cornerstone of this success is the auto-curriculum framework, which shapes the learning process by continually creating new challenging tasks for agents to adapt to, thereby facilitating the acquisition of new skills. In order to extend MARL methods to real-world domains outside of video games, we envision in this blue sky paper that maintaining a diversity-aware auto-curriculum is critical for successful MARL applications. Specifically, we argue that behavioural diversity is a pivotal, yet under-explored, component for real-world multiagent learning systems, and that significant work remains in understanding how to design a diversity-aware auto-curriculum. We list four open challenges for auto-curriculum techniques, which we believe deserve more attention from this community. Towards validating our vision, we recommend modelling realistic interactive behaviours in autonomous driving as an important test bed, and recommend the SMARTS/ULTRA benchmark
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