Mohamed Nayel

• PhD
• Professor at Assiut University

Mycobacterium bovis is the causative agent of bovine tuberculosis (bTB), primarily in bovines; it has a wide host range and zoonotic features. In this report, we aimed to detect the antibodies specific against M. bovis in large ruminants using P22 ELISA, the geographical distribution of bTB-infected cattle and buffalo cases, found positive by GOVs...

Vaccination remains the main control practice for foot-and-mouth disease (FMD), particularly in endemic regions like Egypt, where three FMD virus (FMDV) serotypes (A, O, and SAT2) circulate. This study aimed to compare the immunogenicity of three commonly used FMD vaccines in Egypt by evaluating neutralizing antibody responses against three FMDV se...

The voltage-sag is one of the crucial measures of power quality of electric distribution networks. Among the causes of voltage sag is simultaneously starting of water-pumping motors (WPMs). The key contributions of the present study are optimal sizing and control parameters of the supercapacitor energy storage (SCES) scheme to mitigate the voltage-...

Numerous infections are accountable for abortion in small ruminants, resulting in significant economic repercussions, as well as possessing the potential risk for humans. The current study was undertaken to assess the identification of different risk factors as well as the seroprevalence associated with sheep abortion in Neospora caninum, Toxoplasm...

A method is proposed for calculating the I-V and P–V curves of a PV array composed of series-, parallel- and series–parallel connected-cells or modules or strings exposed to uniform and non-uniform radiation with and without bypass diodes (BpDs). The P–V curve of the array exposed to uniform radiation has one power peak irrespective of the presence...

Currently, the whole world is facing energy shortage and water crisis. Management of water and energy usage in irrigation is essential to overcome the current crisis. This research introduces a techno-economic study to achieve simultaneous optimization of cost, active power loss and water quantity without violating the crop water requirement. Four...

Among the important influences on grounding systems are soil resistivities, as well as climatic changes such as temperature and humidity. Previous scientific research in soil enhancement materials is constantly improving to reduce soil resistance, and then improve the grounding systems to ensure safety of people and public facilities against the ri...

The grounding scheme is one of the main elements for protection system to mitigate the effect of unwanted lightning strikes or operational failures due to faults in generation, transmission and distribution systems. Desert sand soil has a very low electric conductivity, causing weakness in grounding system. To mitigate problems, the soil is support...

One of the most important aspects of power quality for a distribution network's operation is the voltage sag issue. Simultaneous starting of irrigation motors fed from a distribution network leads to a voltage drop, which degrades the network's power quality. Mitigation of the voltage sag was carried out before by using superconducting magnetic ene...

This paper is aimed at assessing by theory and experiment the current–voltage and power-voltage characteristics of a PV module as influenced by dust accumulation. A method is proposed in a computer code to follow-up an incident solar radiation through the module layers considering the reflection and transmission of radiation at the interfaces betwe...

This article presents a roadmap for distribution grid µPMU hardware and software design consideration and implantation to ensure high performance within limited computational time of sampling frequency 512 samples/cycle. A proposed 12 channels, multi-voltage level µPMU hardware and rules of voltage and current transducer, analog filter, analog-to-d...

Background and Objective: The RVF virus cause diseases in newborn puppies, kittens, sheep, goats, cattle, camels, buffaloes and also humans. The RVF disease was first detected among livestock by veterinary officers. The disease causes abortions in animals. The goal of this study was to evaluate the immune response and the haematological profile ass...

Due to the growth of distributed energy resources (DER) and new customer devices, there is currently a two-way energy flow in electric distribution grids. As a result, there is increasing tendency in full observation tools for grid protection and management. Micro Phasor Measurement Unit (μPMU) measures highly precise time-synchronized current and...

It has been more than one year since the first case of the coronaviruses was infected by COVID-19 in China. The world witnessed three waves of the corona virus till now, and more upcoming is expected, whereas several challenges are presented. Empirical data displayed that the features of the virus effects do vary between the three periods. The seve...

Power quality remains one of the most important aspects of the operation of electrical distribution systems. Starting of induction motors causes a voltage sag which negatively affects the power quality. In the present research, the effect of simultaneous energization of water pumping motors on the operation of Karot distribution line is studied. Tr...

Background Haemonchosis is a serious disease affecting ruminants’ productivity worldwide. Medicinal plants are deemed one of the most natural bio-products safely used as alternatives to the synthetic anthelmintics. In the present study, comparative efficacy of crude ethanolic extracts (CEEs) of Artemisia herba-alba ( A. herba-alba ), Balanites aegy...

The Severe Acute Respiratory Syndrome-related Coronavirus 2 (COVID-19 or SARS-CoV-2) epidemic is professed as world disaster producing a worrying increasing mortality, particularly amongst vulnerable humans worldwide. Whether COVID-19 has a strong ability for acceptable genetic flexibility that amended for breaking immune responses quickly, it is c...

Background and aim: Mycoplasma infection in small ruminants is a serious problem in sheep and goat herds around the world. It is responsible for high economic losses and decreased animal productivity. This study aimed to highlight the clinical, histopathological, minimum inhibitory concentration (MIC), and molecular characterization of Mycoplasma...

Integration oflarge-scale renewable energy (RE) sources in particular, photovoltaic (PV) sources into the electric grid introduces current and voltage harmonics due to power electronics devices as well as inverter connected into the RE sources. Ensuring adequate harmonics in the line currents of RE integrated power system is one of the biggest chal...

Internet of Things (IoT) has been widely used in recent years to solve a specific problem or perform an advanced function. In this paper, the IoT is used to build a distributed large-scale smart irrigation system that also aims to improve the load profile and the power quality of the system. Smart irrigation panels with built-in fuzzy logic control...

Monitoring, control, and protection system depending on how the power system has been observed. In order to achieve accurate control and protection functions, fast and accurate estimation of the system state is required. In this paper, an observation strategy for 95-Redial Bus Tie Switch Distribution is presented. The 18 feeders of the distribution...

At present there is a two-ways energy flw in electric distribution grids due to the growth of distributed energy resources (DER) and new customer devices. So, there is growing interest in full observation tools for grid control, protection, etc. Micro Phasor Measurement Unit (µPMU) measures highly accurate time-synchronized samples of current and v...

The aim of this study is to evaluate and improve student thermal sensation in the open spaces of the Faculty of Engineering, Assiut University, Egypt using different shading strategies. Firstly, the thermal conditions of outdoor spaces were evaluated based on field measurements in different locations of shaded outdoor spaces between educational bui...

Although equine herpesvirus-1 (EHV-1) infection occurs throughout the world; causing various health problems within horse population such as respiratory disease, abortion and myeloencephalopathy, there is information shortage concerning the epidemiological situation of EHVs in Egypt. This paper is the first study of EHV-1 prevalence rate in Monufia...

The smart distribution grids monitoring process refers to consistently collect data related to all distributed resources conditions. The dynamic nature of distribution grid systems makes the monitoring tools to be essential in utilizing different types of distributed resources and providing smart services to users. This paper gives a general overvi...

Today’s electric power distribution systems with development of distributed energy resources introduce variability, uncertainty, and opportunities to recruit diverse resources for grid services. Multiple resources on each feeder have more complex impacts on the circuit behavior that can be observed with voltage and current phase angle variations. M...

The study was intended to determine types of Clostridium perfringens and their toxins in diseased sheep with suspected enterotoxaemia, apparently healthy in contact sheep and soil in three Egyptian provinces (one year study). A total of 800 sheep were visited regularly over a period of one year to record cases of enterotoxaemia and collection of sa...

Thoroughbred horse racing is a worldwide sport and industry involving the racing of Thoroughbred horses. It is governed by different national bodies. There are two forms of the sport: flat racing and jump racing. So the study the clinical, hematological and biochemical biomarkers are most useful information that make the race horse such a super ath...

The present experiment was conducted to investigate the effects of copper deficiency in goats on, DNA and chromosomesaberrations. A total number of 16 male goats of 12 months to 1.5 years old were used in the present experiment for 24 weeks. The male goats were randomly divided into two groups. The first group consisted of six animals and was kept...

Soil structure effects grounding systems designed to guarantee safe operation of electric power systems. This work investigated effects of the presence of two/three vertical adjacent mediums on measured apparent soil resistivity. The Wenner method was used to measure the apparent soil resistivity in the vertical-layer soil. Different vertical-layer...

The lightning shielding of different 500 kV HVAC-TL high voltage AC transmission lines was analyzed. The studied transmission lines were horizontal flat single circuit and double circuit transmission lines. The lightning attractive areas were drawn around power conductors and shielding wires. To draw the attractive areas of the high voltage transmi...

Bovine tuberculosis represents one of the very important infectious diseases in Egypt and the world. It has zoonotic importance and causes severe economic losses. Accurate and rapid diagnosis considered as the milestone for control of the disease. In this study ELISA technique was used for confirmation of positive reactors cows that tested with sin...

Echocardiography and intra-cardiac dimensions have not previously been reported in adult egyptian zarabi goats despite its potential application for medical purpose. The chests of 11 adult male goats were examined at 3th - 6th intercostal space on both sides of the thorax using 2.6-6 MHz convex transducer. All chambers of the heart were clearly vis...

A building energy audit was developed through a case study on the science building at Xi'an Jiaotong-Liverpool University (XJTLU). The annual energy consumption of the building was surveyed over a two year period. The building energy consumption characteristics were displayed and the corresponding energy saving potential was analyzed. Additionally,...

Currently, the electricity infrastructure has remained for a long time, while the demand of electricity is increasing. Smart systems could be employed to improve the performance of electric power grid and reduce the . Especially, the communication technology and optimization technology of smart systems are able to enhance the reliability, stabiliza...

Jiangsu is one of the most prosperous provinces in China with the highest population density but a shortage of fossil fuel. However, wind energy is recognized as a sustainable resource which is abundant in Jiangsu Province. Even so, the fluctuation of wind power, offshore and non-grid-connected wind power systems are required to manage this fluctua...

Four-electrode method is one of the well-known methods in measuring ground resistivity. But, most faults currents and lightning currents have high frequencies components. It is proposed to develop this method to study ground frequency characteristics. A step like current was injected into ground to measure the ground impedance. The ground impedance...

This paper studies the effect of frequencies and penetration depth on ground impedance, resisitivity and permittivity. The effect of injected a step like current in the four electrode method for ground resistivity and permittivity measurements are investigated. The ground impedance is obtained from measured voltage and current wave forms. A balance...

In this work the well-known Particle Swarm Optimization (PSO) algorithm is applied to some Dynamic Optimization Problems (DOPs). The PSO algorithm is improved by simplification instead of introducing additional strategies into the algorithm as done by many other researchers in the aim of improving an algorithm. Several parameters (w, V max , V min...

Fusidic acid known to has antibacterial, antifungal, and antimalarial activities. Fusidic acid blocks translation elongation factor G gene in Plasmodium falciparum. In the present study, the inhibitory effects of fusidic acid on the in vitro growth of bovine and equine Babesia parasites were evaluated. The inhibitory effect of fusidic acid on the i...

This paper studies penetration depth and wave propagation in multi-layer ground. A relation between a wave propagation domain frequency, penetration dpeth and multi-layer ground parameters is estimated. An experimental setup is constructed to study the transient characteristics of spherical grounding electrode embedded into ground. The ground is an...

In this study 205 dairy cattle were monitored to determine the clinical and subclinical mastitis prevalence of the major intramammary pathogens, The most prevalent isolated pathogen were Staphylococcus aureus representing 19.47%, followed by E.coli (17.37%), Other bacterial isolates were streptococcus agalactia, Streptococcus dysglactia, Aspergillu...

This study was carried out on ten puppies which subjected to experimental nephrotoxicity by gentamycine. The clinical examination of puppies were dullness, restlessness, polyuria, polydipsia, vomiting, severe salivation and dehydration. Sonographic examination of the affected kidneys in puppies was changed to show greater echogenicity of the renal...

This paper studies and estimates soil resistivity parameters of two-layer vertical soil as a one of the practical soil models. Wenner method is used to measure the apparent soil resistivity. To achieve this study, the image method is proposed to consider the presence of vertical layer soil and four electrodes of the Wenner method. A general apparen...

Bovine ephemeral fever (BEF) is an arthropode borne rhabdovirus, which causes a disabling febrile infection of cattle and water buffalo. A sever outbreak was recorded in Egypt during 2000 and 2001. Using RT-PCR, a primer designed to amplify 438 nucleotide fragments from the glycoprotein G gene allowed specific amplification of BEFV-cell culture iso...

The Candida albicans infection is of minor veterinary significance, however, during the last years a considerable concern has been focused on the illness caused by these yeast. The use of ELISA has been introduced as a new diagnostic tool to evaluate the immune response in case of various diseases including the fungal infections via measuring the l...

This paper proposes a modification to the electrogeometric model. By using Eriksson equation multiplied by a proposed voltage coefficient, electrogeometric models of an unshielded horizontal conductor and a shielded conductor are constructed to study the lightning striking rates at different heights, lightning current and when it is stressed by AC...

This paper studies those parameters affecting the lightning stroke to Lightning rod. The downward lightning leader is modeled by using discrete line charges to consider the exponential distribution of charges through the downward lightning leader. The voltage condition used by Rizk is used and modified to investigate the inception of the upward lig...

This paper studies those parameters affecting the shielding angle of the lightning rod (Franklin Rod) above very tall buildings. It is recommended that the shielding angle of the lightning rod is about 45° ~ 60°. The downward lightning leader is modeled by using discrete line charge to consider the exponential distribution of charges through the do...

This paper studies different parameters affecting a lightning stroke to a horizontal conductor. An electromagnetic model has been constructed to consider the influences of different lightning and horizontal conductor parameters and ambient conditions on the lateral striking distance. The results show that lightning leader parameters, horizontal con...

This paper studies the influence of different parameters on the shielding failure of high voltage direct current (HVDC) transmission lines. A numerical of analysis model considering the developing process of the downward lightning leader based on electromagnetic field theory is used to estimate the lateral striking distance to the transmission line...

This article studies attractive areas around high-voltage direct current transmission lines due to downward lightning leader presence. The lightning-attractive areas are drawn for power conductors and shielding wires separately to distinguish the shielding failure area. An electromagnetic model is constructed to draw the attractive areas of the hig...

This article presents laboratory scale models developed to study the performance of grounding systems in uniform soil. Two parallel grids are investigated and correlated with a same mass grid having the same conductor material and extending over the same area at a depth equal to that of the upper grid. The experimental results demonstrate how the p...

This paper models an anti earthquake building during lightning stroke to the building. The transient voltages due to lightning of modeled building at the connection point between the building and ground base are investigated to study the effect of the connection wire between the building and grounding base of the building. Lightning current was inj...

This paper aims to analysis of the transient characteristics of Long electrode. Field measurements of wave propagation on an underground naked conductor had carried out. Base on the analysis results of wave propagation in the ground the electrode parameters have been detected. Each part of electrode parameters has been calculated. The analysis of e...

An electromagnetic model was constructed to study lightning leader striking distance to horizontal conductors. Two kind of horizontal conductors were investigated, which are horizontal conductor connected to ground and free standing horizontal conductor. A comparison had been done between these two cases. A case of the horizontal conductor stressed...

This paper aims to calculate step and touch voltages around transmission line tower foot due to lightning strike to the transmission line tower top and injecting the lightning current into resistive/capacitive ground. The transmission tower foot is modeled as hemisphere electrode impeded in the ground with specific conductivity and permittivity. Th...

This paper presents the effect of zero reference used in measurements of a grounding electrode transient characteristics. Experimental measurements of many cases of Zero reference have been carried out. Different lengths (20 m, 40 m and 60 m) of the zero reference wire in same and right angel directions to the lead wire direction are examined to ob...

This paper investigates induced voltage between two identical finite horizontal electrodes in same plan (horizontal and vertical). Various arrangements of horizontal electrodes were tested to study the lower and higher induced voltages. Injected voltage and current and induced voltage waveforms were measured to obtain peak voltage and mutual resist...

This paper has experimentally investigated transient voltages on floors in an intelligent building due to lightning with special reference to grounding of a lightning rod, the building and the floors by using an 1/10 scaled-down building model. It has been found that the floor voltages are the smallest in the case of the floors bonded to the buildi...

Fundamental characteristics of a 34-m long horizontal conductor buried at a depth of 1m have been studied with an FDTD method. An equivalent radius of a buried thin wire is shown to be 0.23 times the side of cells employed, which is the same as that of an aerial thin wire. The rate of current dissipating from each section of the buried conductor to...

Self and mutual impedances of grounding electrodes are experimentally investigated for various grounding arrangements and electrode shapes. A transient induced voltage to an electrode is observed to be similar to transient voltages of the electrode and the inducing one when a step-like current is applied individually. Correspondingly, the frequency...

This paper has carried out field measurements of wave propagation characteristics on an underground naked conductor. It has been found that the propagation velocity decreases significantly as the wave travels along the conductor. The propagation velocity and the attenuation of a current are noticeably different from those of a voltage. This has sug...

The present paper has carried out field measurements of surge propagation characteristics on a single straight counterpoise and on a cross-shaped counterpoise composed of two straight counterpoises. It has been found that the attenuation of a current is greater and its propagation velocity is smaller than those of a voltage on the straight counterp...

The present work aims at developing a method--for the first time--for assessing the electric field around a charged conductor positioned in air (of zero conductivity) at a given height above a two-layer earth. The method is based on the complex successive imaging technique, being a quasi-static approximation for estimating the potential due to a li...

The present work is aimed at calculating the magnetic field around a current-carrying conductor positioned in air at a given height above a two-layer ground. The method is based on the successive imaging technique. A three-phase transmission model was constructed to simulate three-phase transmission line above a two-layer ground. The measured magne...