984 research outputs found
Management of citrus nematode (Tylenchulus semipenetrans) by certain plant species
The effect of five plant species (Tagetes erecta L., Datura stramonium L., Nerium oleander L., Ipomea palmata L. and Santolina chamaecyparissus L.) on severity of Tylenchulus semipenetrans on citrus rootstocks (Citrus sinensis, C. reticulate grafted on C. aurantium and C. sinensis grafted on C. aurantium) was investigated in greenhouse and laboratory conditions. All plant species reduced the larval population of T. semipenetrans and their effect increase as the period increase. I. palmata gave the highest percentage of reduction when intercropped with C.sinensis and C. reticulate grafted on C. aurantium 20.5 and 25% respectively. N. oleander and D. stramonium came next when intercropped with C. reticulate grafted on C. aurantium 13.5 and 11% respectively, While D. stramonium gave the highest percentage of reduction when intercropped with C. sinensisgrafted on C. aurantium. And T. erecta gave the lowest percentage of reduction when intercropped with the three rootstocks
Implementation of Adaptive Neural Networks Controller for NXT SCARA Robot System
Several neural network controllers for robotic manipulators have been developed during the last decades due to their capability to learn the dynamic properties and the improvements in the global stability of the system. In this paper, an adaptive neural controller has been designed with self learning to resolve the problems caused by using a classical controller. A comparison between the improved unsupervised adaptive neural network controller and the P controller for the NXT SCARA robot system is done, and the result shows the improvement of the self learning controller to track the determined trajectory of robotic automated controllers with uncertainties. Implementation and practical results were designed to guarantee online real-time
Breakup of turbulent liquid jets in still gases
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76376/1/AIAA-1999-3759-754.pd
Breakup of Round Nonturbulent Liquid Jets in Gaseous Crossflow
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76074/1/AIAA-3749-644.pd
Stay-at-home myopia among school children during the COVID-19 pandemic
Background: Uncorrected myopia represents a major cause of visual disability in children, especially in low-income and middle-income countries. However, there is still debate about the effect of e-learning and “stay-at-home” guidelines on the refractive status of school children, especially in the absence of long-term follow-up data. This study aimed to assess the impact of stay-at-home enforcement during the COVID-19 pandemic on myopia development or progression in students in the Suez Canal Area, Egypt.
Methods: This longitudinal observational study included 1650 students. All students aged 8–15 years with visual complaints, who had attended routine annual vision checks since 2018, were enrolled and assessed annually for myopia development and progression until 2021. Cycloplegic and noncycloplegic refraction, axial length (AL), corneal curvature, and uncorrected and best-corrected distance visual acuity were measured. The participants were administered a questionnaire that focused mainly on collecting information on their visual habits.
Results: Our study included 3,300 eyes of 1,650 school students with myopia during the 4-year study period from 2018 to 2021. The mean cycloplegic spherical equivalents (CSE) were - 1.02, - 1.52, - 2.00, and - 3.50 diopters (D) in 2018, 2019, 2020, and 2021, respectively. This myopic shift in CSE over time was significant (P < 0.001). The average keratometric reading (Avg K) increased significantly during the follow-up period (P < 0.001). The Avg K measurements were 42.32, 42.62, 43.02, and 44.19 D in 2018, 2019, 2020, and 2021, respectively. The changes in Avg K were significant (P < 0.001). The mean AL measurements were 22.53, 22.59, 22.69, and 22.71 mm in 2018, 2019, 2020, and 2021, respectively. Although statistically significant (P < 0.001), changes in AL were clinically insignificant throughout the study period. The mean durations spent on electronic devices at home were 2.12, 2.46, 3.10, and 6.00 hours in 2018, 2019, 2020, and 2021, respectively. The changes over time were significant (P < 0.001).
Conclusions: During the COVID-19 pandemic, studying at home accelerated the degree of refraction toward myopia in school children in Egypt. Further studies are needed to assess the academic performance of students with progressive myopia
STABILITY-INDICATING LIQUID CHROMATOGRAPHY METHOD FOR THE DETERMINATION OF PENTOXYVERINE CITRATE AND ITS DEGRADANT
Objectives: The objectives of this research were to develop and validate a HPLC method for determination of Pentoxyverine citrate (PNX) and its degradant (DG).
Methods: Forced degradation studies were performed on bulk sample using alkaline (0.1M sodium hydroxide) and acid (1M hydrochloric acid. The proposed method was based on using a 150 x 4.6 mm (i. d.) (Luna, Phenomenex, Torrance, CA, USA) (5 µm particle size) reversed phase C18 column with mobile phase consisting of a mixture of methanol-10 mM sodium dihydrogen phosphate pH 4 in ratio of (60:40, v/v) and UV detection at 230 nm with flow rate of 1 mL min-1.
Results: The linear calibration range was between 10-40 mg ml-1and 10-40 mg ml-1for PNX and DG respectively. The method was found to be accurate with 100.23% and 100.07% recovery for PNX and DG respectively. The limit of detection (LOD) was found to be 3.79 x10-2μg ml-1 and 4.24 x10-2μg ml-1 for PNX and DG respectively, while the limit of quantification (LOQ) was found to be 12.62 x10-2μg ml-1 and 14.12 x10-2μg ml-1 for PNX and DG respectively. PNX was found to be most stable at a pH of 5.7.
Conclusion: The validation study of the proposed method was successfully carried out and the method was found to be suitable and economic for routine determination of PNX in pharmaceutical syrup, without any interference from the excipients, and in the presence of its acidic and alkaline degradation products
An improved Henry gas optimization algorithm for joint mining decision and resource allocation in a MEC-enabled blockchain networks
The Effects of Compound Macroeconomic Variables on Economic Growth, Evidence From North African Countries, Using Pardl and the Pvar Approaches
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