Wind tunnel calibration, corrections and experimental validation for fixed-wing micro air vehicles measurements

The increase in the number of Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs), which are used in a variety of applications has led to a surge in low Reynolds number aerodynamics research. Flow around fixedwing MAVs has an unusual behavior due to its low aspect ratio and operates at low Reynolds number, which demanded to upgrade the used wind tunnel for this study. This upgrade enables measuring the small aerodynamics forces and moment of fixed-wing MAVs. The wind tunnel used in this work is upgraded with a state of art data acquisition system to deal with the different sensors signals in the wind tunnel. For accurate measurements, the sting balance, angle sensor, and airspeed sensor are calibrated. For validation purposes, an experiment is made on a low aspect ratio flat plate wing at low Reynolds number, and the measured data are corrected and compared with published results. The procedure presented in this paper for the first time gave a detailed and complete guide for upgrading and calibrating old wind tunnel, all the required corrections to correct the measured data was presented, the turbulence level correction new technique presented in this paper could be used to estimate the flow turbulence effect on the measured data and correct the measured data against published data. First published online 17 February 202

Biocontrol of Bacillus cereus by Lactobacillus plantarum in Kareish cheese and yogurt

This study aims to biocontrol of Bacillus cereus by Lactobacillus plantarum in Kareish cheese and yogurts. The minimum inhibitory concentrations (MICs), antioxidant potentials, total flavonoids content (TFC) and total phenolic content (TPC) of L. plantarum were also estimated. Results showed that incidence of B. cereus in Kareish cheese and yogurt was 16 and 4%, respectively. Four virulence genes were investigated by PCR in B. cereus isolates (n = 10). Two toxin producing genes, cytotoxin K (cytK), and phosphatidylcholine-hydrolyzing phospholipase C (Pc-plc), were detected in all B. cereus, whereas enterotoxigenic (nhe) and hemolysin BL (hbl) genes were detected in 90 and 50%, respectively. All isolates were vulnerable to erythromycin and gentamicin (100%) with intermediate sensitivity to ciprofloxacin and complete resistance to tetracycline (100%). L. plantarum showed antibacterial power against B. cereus EMCC1006 reference strain with MIC at 3.1 mg/mL. From the different concentrations (1.5, 3.1, 6.25, 12.5, 25.0, 50.0, 100.0 mg/mL) of L. plantarum which mixed with Kareish cheese and yogurt samples, the minimum concentrations displayed the excellent sensory parameters. TPC and TFC of L. plantarum CFS were 18.5 (μg GAE/g) and 2.67 (μg QE/g), respectively. Regarding antioxidant activity, IC50 of L. plantarum was 53.84 μg/mL, while IC50 of ascorbic acid was 26.36 μg/mL. In sum, L. plantarum could be used as a promising antibacterial and antioxidant agent for biocontrol of B. cereus to ensure dairy safe without negative impact on sensorial attributes.Universidade de Vigo/CISU

Rituximab efficacy in pediatric patients with refractory nephrotic syndrome

Background: Nephrotic syndrome (NS) in children is a disease of glomerular filtration barrier failure, manifesting with severe proteinuria leading to hypoalbuminemia, hypercholesterolemia, and generalized edema. it could be primary or secondary. In primary NS, also known as idiopathic NS, the histological findings of Primary NS include minimal change disease which mainly respond to steroids (steroid sensitive NS), focal segmental glomerulosclerosis which are usually steroid resistant or membranous nephropathy. Rituximab has been shown to be effective for patients with complicated FRNS/SDNS and refractory SRNS. While the incidence of nephrotic syndrome (NS) is increasing, the morbidity of difficult-to-treat NS is significant.Methods: This is a retrospective cohort study that took place in King Abdulaziz University Hospital from 2012 to 2016. Patients included: Any patient under 18 years, and diagnosed with steroid resistant and dependent nephrotic syndrome. Patients excluded: Any patient above 18 years, and known to have secondary Nephrotic Syndrome.Results: Present study consists of 24 children with nephrotic syndrome (NS) were recruited in the study. In the population 8 patients (33.33 %) were diagnosed with SDNS, while the other 16 patients (66.67%) were diagnosed SRNS. Also, patients who were treated with Rituximab we found that (the mean) number of relapses per year before rituximab was about 2.67±1.49 (standard deviation 1.49), while patient who relapsed after rituximab was about 1.09±1.38 (standard deviation 1.38).Conclusions: Rituximab is a biological agent that started to be widely used in difficult nephrotic syndrome cases. The effectiveness of rituximab is most observed in steroid depended nephrotic syndrome patients since it decreases the frequency of relapses and steroid dependency. However, it has been shown that it is less effective in steroid resistant nephrotic syndrome cases and was associated with significant numbers of relapses

Improved finite samples resampling for unbiased wide-band direction of arrival estimation,’’ submitted to Acoust. Sci

Abstract: This paper considers wide-band DOA estimation using the spatial resampling method for coherent averaging. In this paper a rough estimate of the resampling error distribution is obtained. Careful examination of this distribution yields an improved resampling formula suitable for, but not limited to, arrays with finite sensors. It is shown that the proposed formula yields resampling error much less than that of conventional resampling. Moreover it is shown how the resampling error can be more reduced by proper choice of the focusing frequency. Based on the this resampling formula a perfect focusing scheme is then proposed and its performance is evaluated and compared to other wide-band methods through simulations. Simulations showed quite satisfactory and robust performance of the proposed scheme. It was shown that it succeeds in situations where all considered wideband methods fail. In addition it is bias-free and can be implemented quite efficiently. Hence it is quite suitable for reliable real-time DOA estimation in reverberant environments

Allelopathic efficiency of Eruca sativa in controlling two weeds associated with Pisum sativum plants

Allelopathy is a complex phenomenon which depends on allelochemical concentrations. So, two pot experiments were carried out to investigate the allelopathic effect of alcoholic fresh shoot extract of Eruca sativa (foliar spray) and E. sativa shoot powder (mixed with soil) on Pisum sativum plants and two associated weeds, Phalaris minor and Beta vulgaris. The experiments were conducted in the greenhouse of the National Research Centre, Giza, Egypt during two successive winter seasons (2016–2017 and 2017–2018). Ten treatments were applied in this study. Four treatments were applied before sowing, that E. sativa shoot powder was mixed with the soil at rates of 15, 30, 45 and 60 g ⋅ pot–1. The other four treatments of E. sativa alcoholic fresh shoot extract were sprayed twice on both plants and weeds at 5, 10, 15 and 20% (w/v) concentrations. Additionally, two untreated treatments, healthy (P. sativum only) and unweeded (untreated infested P. sativum plants with weeds) were applied for comparison. The results indicated that both alcoholic extracts and powder reduced growth of both weeds. Moreover, there was a direct relationship between concentration and weed reduction. Eruca sativa alcoholic extracts increased yield parameters of P. sativum plants. The maximum yield attributes were recorded by spraying of E. sativa alcoholic extract at 20%. On the other hand, it was clearly noticed that the high powder rates affected negatively P. sativum yield parameters. But the lowest powder rate (15 g ⋅ pot–1) stimulated P. sativum yield parameters as compared to unweeded treatment. Chemical analysis of E. sativa shoot powder ensured that the abundant amount of glucosinolates (9.6 μmol ⋅ g–1) and phenolic compounds (46.5 mg ⋅ g–1) may be responsible for its allelopathic effect. In conclusion, spraying of alcoholic fresh shoot extract of E. sativa at 20% (w/v) and mixing E. sativa shoot powder at 15 g · pot–1can be applied as natural bioherbicides for controlling weeds

Assessing chamomile and marjoram meals as feed additives on growth indices and haematological parameters of Nile tilapia (Oreochromis niloticus) reared under biofloc system

First report on using chamomile (Matricaria chamomilla) flower meal [CFM] and marjoram (Origanum majorana) leaves meal [MLM] as dietary supplements in low-protein fish diets on Nile tilapia (Oreochromis niloticus) reared in a bio-floc system. The experiment consisted of 6 groups in triplicates, where the first (T1) and second (T2) groups were fed diets containing 25 and 20% protein, respectively, without any additives. In contrast, the rest of the groups were fed a 20% protein diet, adding CFM at rates of 1% (T3) and 2% (T4) or MLM at rates of 1% (T5) and 2% (T6). The fish were initially weighed 18.44 g ± 0.38 (S.E.) and randomly stocked in 18 experimental tanks at six fingerlings in a water volume of 40 litres (150 fish/m3). Molasses was used as a carbon source with a carbon-to-nitrogen ratio of 16:1 in the treatments fed 20% protein; 12:1 in the treatments provided 25% protein. Feeding was done twice daily, six days a week, at a rate of 3% of body weight for 42 days. Water quality was within the desirable tilapia growth and health limit regarding temperature (23.20 - 24.70 °C), pH (8.43 - 8.65), dissolved oxygen (5.5 - 6.1 mg/L), and NH3 (0.03–0.051 mg/L). Fish fed on a 20% CP diet containing 1% CFM had the highest values in all growth indicators, followed by 2% CFM and 1% MLM then T1 and T2 groups. Blood analysis showed variation (P ≤ 0.05) among groups, and T3 had the highest levels of hemoglobin (Hb), hematocrit (Hct), and red blood cells (RBCs) followed by T5 then T4, T2, while T6 and T1 were the least. In conclusion, using chamomile or marjoram as a feed supplement maximizes the benefits of using the bio-floc system, especially in a lack of water resources and poor protein feeds. Nile tilapia growth and hematological parameters were the best with a 1% chamomile (M. chamomilla) supplement under a biofloc system