ESDA2004-58427 MODELING AND ANALYSIS OF AN ULTRA LIGHT SLOW FLYER WITH VARIABLE SHAPE CONTROL SURFACES USING SHAPE MEMORY ALLOY ACTUATORS

ABSTRACT Applying flexible variable shape control surfaces (wing and elevator) structures is a way to increase efficiency and maneuverability of the planes, which is recently under research. In this paper, modeling of the flight of an unmanned ultra light plane is discussed. The modeling is done based on a real ultra light plane presented recently. To increase maneuverability of the plane, flexible variable shape structures are designed for the wing and the elevator. In design procedure, having an ultra light plane is considered. The elevator and the wing are used as control surfaces for longitudinal and lateral maneuvers respectively. Shape memory alloys (SMA) are used for reshaping the flexible structures of the wing and the elevator. Because of its high power and low weight and nearly unlimited resolution, SMA is best suited as the actuator of the reshaping wing and elevator structures. In flight dynamic modeling of an ultra light plane with variable shape wing, aerodynamic coefficients are needed. Coefficients are computed using computational fluid dynamics (CFD). To determine the reshaped structures, finite element models of structures are constructed in ANSY

Saturation in cascaded optical amplifier free-space optical communication systems

The performance of a free-space optical (FSO) communication system in a turbulent atmosphere employing an optical amplifier (OA) cascade to extend reach is investigated. Analysis of both single and cascaded OA FSO communication links is given and the implications of using both adaptive (to channel state) and non-adaptive decision threshold schemes are analysed. The benefits of amplifier saturation, for example in the form of effective scintillation reduction when a non-adaptive decision threshold scheme is utilised at the receiver for different atmospheric turbulence regimes, are presented. Monte Carlo simulation techniques are used to model the probability distributions of the optical signal power, noise and the average bit error rate due to scintillation for the cascade. The performance of an adaptive decision threshold is superior to a non-adaptive decision threshold for both saturated and fixed gain preamplified receivers and the ability of a saturated gain OA to suppress scintillation is only meaningful for system performance when a non-adaptive decision threshold is used at the receiver. An OA cascade can be successfully used to extend reach in FSO communication systems and specific system implementations are presented. The optimal cascade scheme with a non-adaptive receiver would use frequent low gain saturated amplification

Performance evaluation of turbulence-accentuated interchannel crosstalk for hybrid fibre and free-space optical wavelength-division-multiplexing systems using digital pulse-position modulation

A hybrid fibre and free-space optical communication link using digital pulse-position modulation (DPPM) in a wavelength-division-multiplexing system is proposed. Such a system, which could provide a power efficient, robust and flexible solution to high-speed access networks, is a contender for a passive optical network solution and could readily be deployed in areas with restrictions in optical fibre installation, or alternatively as a disaster recovery network. Interchannel crosstalk and atmospheric turbulence are major impairments in such a system and could combine in some cases to degrade the system. Both impairments are investigated here and the results are presented in the form of bit error probability, required optical transmission power and power penalties. Depending on the position of the interferer relative to the desired user, power penalties of about 0.2–3.0 dB for weak turbulence and above 20 dB for strong turbulence regimes are reported for bit error rate of 10−6. DPPM scheme with a coding level of 2 show about 2 dB improvements over on–off-keying scheme

Sex determination using mandibular anthropometric parameters in subadult Iranian samples

Introduction: Sex determination is the first step in the identification of corpses and skeletal remains. The mandible is the largest and strongest bone of the face and has high durability. It is known that skeletal features vary by population, thus the need to establish population-specific standards. In this study, for the first time, we investigated mandibular anthropometric parameters for sex determination in subadult Iranian cadavers. Methods: Eight mandibular anthropometric parameters were measured in 45 Iranian cadavers below the age of 20 (23 males and 22 females corpses), and the relationships of these variables with gender were determined. Collected data were analyzed using descriptive analysis, ROC curve, cross tabulation and discriminant analysis in SPSS 13. Results: No significant statistical difference was seen in the mandibular anthropometric values between the two genders in samples below the age of 12. In the 12-19 age group, accuracy of symphysial height and bigonial breadth in differentiation of gender was 69 and 86.2 respectively. Conclusion: Although mandibular anthropometric parameters are not helpful in sex determination below the age of 12, if for some reasons such as explosions, air disasters and other accidents, only the mandible is available, symphysial height and mandibular bigonial breadth could be used to determine the gender with high accuracy. (C) 2013 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved

Nonisothermal pore diffusion model for a kinetically controlled pressure swing adsorption process

10.1021/ie3004539Industrial and Engineering Chemistry Research513210659-10670IECR

Evaluating the efficacy of probiotic on treatment in patients with small intestinal bacterial overgrowth (SIBO) - A pilot study

Background & objectives: Small intestinal bacterial overgrowth (SIBO) leads to several gastrointestinal (GI) problems and complications leading to malabsorption. The effectiveness of probiotics in the treatment of SIBO syndrome has not been well studied. This pilot study was aimed to assess the efficacy of a probiotic consisting of lactobacilli in the treatment of SIBO. Methods: In this study, 30 cases suffering from chronic abdominal pain or diarrhoea and with a positive hydrogen breath test were randomized in a double-blind manner into two groups: probiotic drug user and control group. After an initial 3-week aggressive therapy with broad-spectrum antibiotics, a 15-day maintenance antibiotic therapy with lactol was administered for the study group and the same regimen without lactol for the control group. After six months the HBT result and the GI symptoms were analyzed and compared between the two groups. Results: The result of hydrogen breath test and the clinical symptoms in patients receiving the maintenance regimen with lactol probiotic showed a better response. The hydrogen breath test turned negative in 93.3 per cent of those receiving lactol compared to 66.7 per cent of the controls. In all the cases receiving lactol, the abdominal pain disappeared completely ( p =0.002). In addition, other GI problems including flatulence, belching and diarrhoea significantly improved in the study group ( p <0.05). Interpretation & conclusions: Based on the preliminary data it seems that adding lactol probiotic to the maintenance therapy of small intestinal bacterial overgrowth patients on routine antibiotic therapy will be beneficial in preventing the complications of this syndrome

Optimizing the PSA process of propylene/propane using Neuro-Fuzzy modeling

10.1016/B978-0-444-59506-5.50098-5Computer Aided Chemical Engineering311336-134

A positive effect of egg consumption on macular pigment and healthy vision: a systematic review and meta-analysis of clinical trials

Increasing macular pigment optical density (MPOD) as a result of increased macular concentration of lutein and zeaxanthin may reduce the risk of age-related macular degeneration (AMD). The aim of the present study was to determine whether the consumption of eggs, a rich source of dietary lutein and zeaxanthin, influences MPOD and serum lutein. In this systematic review and meta-analysis we searched PubMed, Scopus, and ISI Web of Science up to July 2020, for relevant randomized clinical trials. Using a random-effects model, pooled weighted mean differences, and standard deviations (SDs) for each outcome were obtained. The quality of the eligible studies was assessed by the Cochrane Collaboration's tool. A meta-analysis of five trials (296 participants) revealed that egg consumption significantly increased MPOD (weighted mean differences (WMD): +0.037; 95 CI: 0.004, 0.069; P = 0.027) and serum lutein (WMD: +0.150 μmol L�-1; 95 CI: 0.037, 0.263; P = 0.009). Subgroup analyses showed that egg consumption: (a) had a larger effect on MPOD in studies with a parallel design; and (b) increased serum lutein to a greater extent in a healthy population. We did not detect any heterogeneity between studies. Daily egg consumption has beneficial effects on MPOD and serum lutein is inversely associated with reduced AMD progression. Further clinical trials are required to confirm the results of this study. © 2021 Society of Chemical Industry. © 2021 Society of Chemical Industr