2,721 research outputs found
Determination of the Level of Organophosphorus Pesticides in Tomato Using GC-MS/MS and the Concentration of Some Heavy Metals Using FAAS
No full textThis study was carried out to develop and apply a quick, yet efficient, analytical method for simultaneous determination of the residues of the 86 pesticides repeatedly detected in food commodity in Al-Rass province of Al-Qassim Region, Saudi Arabia. The suggested method is based on QuEChERS extraction procedures based on acetonitrile followed by a dispersive solid-phase extraction (d-SPE) with primary-secondary amine (PSA) and bulk of carbograph for clean-up, was applied prior to GC-MS/MS analysis, focusing in particular on tomato crops. The second aim of the study was to measure the levels of some heavy metals using FAAS technique, particularly, Cu, Cd, Zn, Fe and Pb. The third aim was to evaluate the effectiveness of some common household-type preparations and handling procedures for tomato on reducing the levels of the detected pesticide residues as well as the heavy metals. The current findings could provide that the proper home preparation of tomato samples, in particular, soaking in 2% sodium chloride solution and soaking in commercial 5% acetic acid has led to effective elimination of the pesticide ethion from those samples. However, results have shown that there was no significant effect on the levels of heavy metals in the investigated tomato samples after applying the common types of household treatments
Survey on the Moisture and Ash Contents in Agricultural Commodities in Al-Rass Governorate, Saudi Arabia in 2017
No full textResearchers and governments are paid great interest concerning food safety and quality of food stuff. Determination of moisture and ash contents was ac-complished by using simple, easy and low cost method to establish a database for agricultural commodities.Twenty four types of agricultural commodities were collected from the local market in Al-Rass governorate, Al-Qassim region, Saudi Arabia. The samples were collected in the period from the beginning of January 2017 to the end of July 2017. The survey show that higher values of moisture contents were found in tomato and cucumber (95.79 and 94.65%, respectively)while the higher values of ash content were found in leafy vegetables in particu-lar spinach and watercress of 1.91% and 1.51% respectivel
Evaluating the Cultural Heritage and landscape of Quseir - Qift Road: with a special focus on the gold mines and greywacke quarries
No full textThe study is divided into two parts preceded by an introduction and entailed by a conclusion as follows:
Part I: Archaeological Survey of Quseir – Qift road
This part is divided into two chapters surveying the road and the ports flanking the road between the Nile and the Red Sea.
Chapter I: sheds the light on the hydreumata along the Quseir (Myos Hormos) - Qift (Coptos) road which are:
Bir Nakhil, Dawwi, Bir Sayyala, Bir al Hamara, Al – Zarqa (Maximianon), Bir Fawakhir (Persou II), Bir Hammamat (Persou I), El Muwayh “Krokodilo” and Qusur El Banat.
Chapter II: deals with the ancient port network between the Nile and the Red Sea due to the importance of the Myos Hormos road in the ancient times as the shortest road linking the Nile port of Coptos (Qift) with the Red Sea port of Myos Hormos (Quseir) in addition to the role played by the ancient port of Saww (Mersa Gawasis) from the Pharaonic Perod till the 2nd century AD.
Part II: Cultural Heritage Values of the Quseir - Qift road
This part is divided into three chapters underlining the different heritage values along the Coptos – Myos Hormos road.
Chapter III: underlines the gold mines and the value of gold in Ancient Egypt, the evolution of gold extraction in Bir Umm Fawakhir along the different historical phases from the Pre - dynastic period till the Ptolemaic and Roman – Byzantine era and the impact of this activity on creating the settlement that was once inhabited by the miners.
Chapter IV: studies the greywacke (Bekhen stone) quarries and the development of quarrying techniques through the analysis of the numerous inscriptions left by the members of the various expeditions sent to extract this stone in the greywacke mountain of Wadi Hammamat. These textual evidences helped in rendering the various Quarrying phases starting with the Extraction process upon the arrival to the quarry till the Transportation towards the destination on the Nile valley passing by the Logistics that once regulated the work of large - numbered expeditions in the desert such as the distribution of goods, food and other necessities for the workers and the water supply in addition to the cultic and the religious aspects of the region.
Chapter V: represents the valorization of the heritage value of Coptos – Myos Hormos road through elaborating a number of arguments related to the life of the road that forms a pass towards the realization of a desert road archaeology study. This part of the study includes some proposed ideas towards the ideal use of the potentials of the surveyed areas from the tourism point of view promoting new itineraries and developing projects that may participate as a possible a solution due to the recent status of tourism in Egypt
Data for: Does Bitcoin add value to global industry portfolios? _CRC2019
No full textSpillover Approach Cod
Financial stress dynamics in the MENA region: evidence from the ArabSpring
No full textIn this paperwe analyse the impact of instability caused by the Arab Spring on the co-movements and volatility spillovers of aggregated Financial Stress Indices for eight MENA countries. Using a dynamic frequency connectedness framework,we conclude that stress transmission between markets is higher at low frequencies than at high frequencies, which implies that MENA markets are slow in adjusting to the information they receive. The Global Financial Crisis generated stronger spillover effects between MENA markets than the political turmoil of the Arab Spring. These results are useful for investors with different investment horizons, and have policy implications for the maintenance of financial stability in this region
Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics
No full textZidan, Islam Mohammad, El-Saiedy, Elsayed Mohamed Ahmed K., Abou-Elella, Gomaa Mohamed, Hassan, Mourad Fahmy (2022): Predatory mites, a green pesticide, and an entomopathogenic compound: A proposed IPM tactic based on pest species diversity indices and population dynamics. Persian Journal of Acarology 11 (4): 731-752, DOI: 10.22073/pja.v11i4.7621
HandMECH—Mechanical hand prosthesis: Conceptual design of a two degrees-of-freedom compliant wrist
No full textA compliant wrist joint is important for positioning the hand in different positions to perform various daily tasks. It is also important that the wrist is able to achieve sufficient range of motion (RoM). The RoM is determined by classifying the daily activities and the most critical applications. This study presents kinematical, structural and kinetic analyses of the conceptual design of a wrist joint in mechanical hand prosthesis: HandMECH. Kinematic and kinetic analyses are carried out to determine the design parameters of the wrist to handle daily activities. Structural analyses is performed to evaluate the stress distributed over the critical part of the wrist and show that the design with a mass of 50 g satisfies the applied boundary condition
Volatility and return connectedness of cryptocurrency, gold, and uncertainty: Evidence from the cryptocurrency uncertainty indices
No full textThis paper examines the dynamic connectedness of return- and volatility spillovers among cryptocurrency index (CRIX), Gold, and uncertainty measures. Apart from traditional uncertainty measures, we also consider two novel uncertainty measures: Cryptocurrency Policy Uncertainty and Cryptocurrency Price Uncertainty indices. We observe that cryptocurrency policy uncertainty is the main transmitter of the return spillovers to other variables. In addition, Gold is a net receiver of both the return and the volatility spillovers. These results are valid under bearish, bullish, and normal market conditions. Our findings contribute to the literature considering the spillover effect between cryptocurrencies and other assets and their determinants
Fuzzy sliding mode control for cart Inverted Pendulum system / Belal Ahmed Abdelaziz Elsayed
No full textCart Inverted Pendulum (CIP) is a benchmark problem in nonlinear automatic control which has numerous applications, such as two wheeled mobile robot and under actuated robots. The objective of this study is to design a swinging-up controller with a robust sliding mode stabilization controller for CIP, and to apply the proposed controller on a real CIP. Two third-order differential equations were derived to create a combining model for the cart-pendulum with its DC motor dynamics, where the motor voltage is considered as the system input. The friction force between the cart and rail was included in the system equations through a nonlinear friction model. A Fuzzy Swinging-up controller was designed to swing the pendulum toward the upright position, with consideration of the cart rail limits. Once the pendulum reaches the upward position, Sliding Mode Controller (SMC) is activated, to balance the system. For comparison purposes, a Linear Quadratic Regulator Controller (LQRC) was design and compared with proposed SMC. Simulation and experimental results have shown a significant improvement of the proposed SMC over LQRC where, the pendulum angle oscillations were decreased by 80% in the real implementation
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