2018 9th International Renewable Energy Congress (IREC), 2018
DC current offset severally affects the distribution system components such as; isolation transfo... more DC current offset severally affects the distribution system components such as; isolation transformers, measurement units and protective relays. Various DC current offset compensation techniques hypothetically are suitable to compensate DC current injected by grid connected inverters This paper presents a technique to stifle DC current injection into the AC grid which can be applied to medium-scale solar farms or any gathering of lattice connected inverters restricted to a moderately little zone. The importance of this system is that it does not depend on high current measurement devices and does not utilize any type of complex transformers. Also, it permits an operation without transformer for all inverters inside the solar farm and there must be at least one inverter to perform DC offset compensation in addition to its essential function of active power interfacing into the AC grid. This inverter is needed to substitute all DC offsets that can be found in the solar farm current before reaching the main interfacing transformer, therefore we can avoid the hazard of transformer saturation.
International Journal of Innovative Research in Science, Engineering and Technology, 2015
This paper presents evaluation of effect of in-wheel electric motors mass on the performance of a... more This paper presents evaluation of effect of in-wheel electric motors mass on the performance of active suspension system by using one of more common control methods which is Linear Quadratic Regulator (LQR).Unsprung mass is one of the important parameters which effects on road holding and ride comfort behaviors in the vehicles, this effect obtained in this work by comparing the performance of the system using standard tire and tire with In-Wheel Electric Motor. Also,modeling and simulation of quarter car model completed to construct the Simulink model of the system using MATLAB software. The study summarized bad effect of increasing the weight of tires by add In-Wheel Motors to the system on the road traction and the vehicles drivers comfort, at the same time the suspension system with in-wheel motor needs high actuator force to work compared to the same system without inwheel motor
Introduction: This Study has was carried out to measure and detect the natural occurred radionuc... more Introduction: This Study has was carried out to measure and detect the natural occurred radionuclide content including 226Ra, 232Th and 40K in the Nile River sediments at various locations in Upper Egypt, from Aswan to El-Minya. Additionally, we determine the absorbed dose rate, the annual effective dose equivalent, and excess lifetime cancer risk also has been calculated. Material and Methods: The gamma ray measurements were performed with a high resolution High-Purity Germanium detector, low background, and Personal Computer multichannel analyzer. Results: In Aswan Governorate, the mean specific activities of radionuclide's (226Ra,232Th and 40K) 14.86, 13.78 and 175.4 in Bq/kg respectively. In Qena Governorate, the mean specific activities of mentioned radionuclides were 14.44 Bq/kg, 15.02 Bq/kg and 197.57 Bq/kg, respectively. These values were18.53 Bq/kg, 11.3 Bq/kg and 184.73 Bq/kg in Sohag Governorate, respectively. In Asyut Governorate the mean specific activities of t...
This paper presents a Li-ion battery storage system provided with a supercapacitor as a backup mi... more This paper presents a Li-ion battery storage system provided with a supercapacitor as a backup micro-fuel interface scheme to AC/DC power system that can be utilized during maximum demand circumstances. Distributed flexible AC transmission system (D-FACTS) based–switched filter compensator (SFC) scheme is proposed to ensure energy efficient of battery charging scheme. A dynamic multi-level error-driven control strategy is proposed to guarantee better power quality performance in terms of fast charging of the battery storage system, voltage enhancement and stabilization of the DC and AC buses, improvement of power factor of AC buses, inrush current minimization and harmonic current distortion reduction. The proposed SFC is controlled by means of a multi-level functional error-driven intercoupled weighted modified proportional-integralderivative (WM-PID) controller. Grey wolf optimization is employed for tuning PID controller gains in terms of change at state of charge (SOC) and to re...
A glaucoma is a group of eye conditions that damage the optic nerve, which is vital to good visio... more A glaucoma is a group of eye conditions that damage the optic nerve, which is vital to good vision and if not detected early eventually leads to irreversible blindness. Primary open-angle glaucoma the most common type of glaucoma which occurs due to an imbalance of the eye liquid drainage and production. Although, Primary open-angle glaucoma's optic neuropathic nature which features retinal ganglionic cell loss representing the most prevalent form of glaucoma, its exact a etiology and pathogenesis are unknown. Numerous studies have reported the genetic factor that contributes to the progression of POAG including molecular changes in the trabecular meshwork causing stiffness eventually leading to increased intraocular pressure. Therefore, studying the genetic factors and other causes of POAG could help lead to early diagnosis and eventually slow the progression of the disease. However, to this very day, several gene mutations have been described and established to be the causative factors of POAG with some genetic analyses including genomewide association studies. In this review, we will be focusing on the factors that contribute to the pathology of POAG and the damages that occur to the visual cortex.
IEEE Open Journal of Antennas and Propagation, 2020
The design of a low-profile wideband shared-aperture dual-polarized antenna is proposed. The prop... more The design of a low-profile wideband shared-aperture dual-polarized antenna is proposed. The proposed antenna consists of a cavity-backed slot antenna to produce vertical polarization and a slot-backed monopole antenna for horizontal polarization. The slot operates as a radiator for vertical polarization and at the same time, it works as a reflector for horizontal polarization. Two antenna prototypes are designed and simulated. The initial design has a profile of 0.28λ max , where λ max is the free space wavelength at the lowest frequency. The vertical and horizontal polarized antennas exhibit 36.1% and 39.7% bandwidths, respectively. By adding a notch in the slot, the current path increases, which reduces the operating frequency band; hence, the low-profile design is accomplished. The new version features a profile of 0.17λ max with 28.2% and 36% bandwidths for vertical and horizontal polarizations, respectively. The low-profile prototype is fabricated and measured. The measured S-parameters are consistent with the simulated one. The measured realized gain varies from 1 to 4.2 dBi for vertical polarization, while it varies from 1 to 2.5 dBi for horizontal polarization. The total efficiency of the proposed antenna is above 85% within the operating band for both polarizations. The far-field radiation pattern is measured, and a good agreement is achieved with the simulated one.
Suez Canal Veterinary Medicine Journal. SCVMJ, 2016
A total number of 77 marine fishes of 3 species represented as 23 Abu Sabib (), 24 kosher Abu L... more A total number of 77 marine fishes of 3 species represented as 23 Abu Sabib (), 24 kosher Abu Lolo (Epinephelus fasciatus) and 30 Sigan (Siganusluridus) were collected seasonally between May 2014 and the end of April 2015 from coral reef sites along the shore of the National Institute of Oceanography and Fisheries (NIOF) at Hurghada's Red sea. They were investigated for detection of parasitic copepods. It was revealed that 31.16% of the examined marine fishes were infested. The detected species were belong to Genus Hatschekia Poche1902 from with a prevalence78.26%, and from Siganus luridus with prevalence 20% while not detected in Epinephelus fasciatus. The total and seasonal prevalence of infestation in each fish species in relation to body weights and lengths were recorded. Besides, the histopathological alterations were studied and discussed.
Thermal neutron detectors, which are based on semiconductor material such as silicon coated with ... more Thermal neutron detectors, which are based on semiconductor material such as silicon coated with neutron reactive material like 6 LiF have been discussed for many decades. The performance of the thermal neutron detector system, GAMBE (GAMma Blind neutron Efficient), which is based on two silicon sensors in a sandwich configuration is investigated. This detector is able to achieve a total and a coincidence detection efficiency of 4% and ∼1% respectively. The thermal neutron detection efficiency of the detector is enhanced by using a stacked detector configuration and high-density polyethylene (HDPE) sheets, as neutron moderators and reflectors. The GAMBE detector is positioned inside a box of HDPE with a lead window in the direction of the neutron flux for neutron moderation and a reduction of the effect of gamma-rays on the detector. The experimental layout was modeled in MCNP4C to investigate the contribution of HDPE to the thermal neutron flux (n/s/cm 2). In this research a stack of 4 silicon semiconductor sensors with (2.6±0.6) and (2.9±0.6) mg/cm 2 thick 6 LiF film in a configuration of two sandwiches is shown to achieve a total and a coincidence detection efficiency of 27% and 4% respectively. This represents a significant improvement compared to a single detector. The effect of these stacked detectors for the development of a handheld thermal neutron detector, using 4 coated Si detectors is shown to have a 22% efficiency. This information is used to inform the optimised design of the handheld detector. The results based on geant4 and MCNP simulations indicate that the total detection efficiency of this portable detector with a stack of 7 sandwich detectors will increase up to 52% by using an optimal thickness of 6 LiF of 3.95 mg/cm 2 .
As fundamental importance to SEM observation of specimen surface, secondary electron generation a... more As fundamental importance to SEM observation of specimen surface, secondary electron generation and emission processes have been studied by a Monte Carlo method. The simulation is based on a discrete description of cascade secondary electron production. The Monte Carlo model combines the use of Mott's cross section for electron elastic scattering and of Penn's dielectric function for electron inelastic scattering. Two models of dielectric function, i.e. the single pole approximation and the full Penn algorithm, are shown to give energy distribution and yield of secondary electrons in agreement with experimental results for non-free electron materials and free electron metals, respectively. We use a constructive solid geometry modeling to describe sample 3D geometry and a Gaussian function to describe random surface roughness. The technique is efficient and powerful in a simulation of SEM images of secondary electrons and backscattered electrons for a quite complex geometry of nanostructures. Finally we present the depth distribution functions for secondary electron generation and emission. Their dependences on primary energy and atomic numbers are analyzed. Furthermore, we shall also discuss a general issue of depth distribution function for rough surfaces.
The International Conference on Chemical and Environmental Engineering, 2012
The changes of optical and electrical properties of aniline hydrochloride/polyvinyl alcohol films... more The changes of optical and electrical properties of aniline hydrochloride/polyvinyl alcohol films (AN/PVA) influenced by gamma radiation for the purpose of gamma dosimetry are presented in this work. Optically, by exposing films to doses of gamma radiation from 0 to 10 kGy, films showed visually apparent gradual change in color from violet to yellow green with increase of absorbance at 424 nm. Electrical, conductivity also was increased regularly in the same dose range. It can be suggested that aniline hydrochloride in the AN/PVA form may be used for dosimetry for the mentioned dose range.
The International Conference on Chemical and Environmental Engineering, 2010
In this study, Tartarzine aqueous solution was investigated as a simple low-dose dosimeter in the... more In this study, Tartarzine aqueous solution was investigated as a simple low-dose dosimeter in the range of 20-500 Gy for the high ionizing radiation, gamma ray. Gradual bleaching of Tartarzine solution was observed with dose by measuring the absorbance of Tartarzine-solutions at specified wavelength, λ max = 430 nm. Tartarzine concentration (10-4 , 5 ×10-4 and 10-3 M) and solution-initial pH value (5, 7 and 9) were considered as factors affecting degree of bleaching. It was found that Tartarzinesolution color was diminished gradually with selected dose range. The rate of bleaching increases with the increase of solution-initial pH. Increase of Tartarzineconcentration causes widening of range to which solution is susceptible. The postirradiated effect (24 hours) was found to cause more bleaching. The sensitivity of Tartarzine solution is not regular with the Tartarzine-concentration and regular with pH.
International Conference on Aerospace Sciences and Aviation Technology, 2015
In the present work, aniline doped aluminum oxide films were prepared by the Sol-Gel technique fo... more In the present work, aniline doped aluminum oxide films were prepared by the Sol-Gel technique for gamma radiation dosimetry. Aniline (AN) was suggested to enhance the electrical conductivity of films. Measured conductivity due to gamma radiation was studied in the 0-10 kGy dose range. Conductivity was enhanced with AN doping. Conductivity and sensitivity values up to 150 (µΩ-1 .cm-1) and 3.75 (mA.cm ــ 2ــ .kGy ــ 1ــ) respectively were achieved at 0.25 g AN content and 25 V bias.
Pregnancy failure and placenta mediated pregnancy complications affect >25% of pregnancies. Al... more Pregnancy failure and placenta mediated pregnancy complications affect >25% of pregnancies. Although there is biological plausibility for a procoagulant mechanism underlying some of these events, antithrombotic intervention trials demonstrate limited benefit, possibly through lack of stratification in heterogeneous patient groups. The ANXA5 M2 haplotype is a possible procoagulant biomarker and was tested pragmatically to determine whether this screening and LMWH treatment normalized the outcome for ANXA5 M2 positive couples. This was a pragmatic study that aimed to measure the effectiveness of a testing (for the M2 haplotype) and treatment (LMWH) pathway in routine clinical practice where there is variation between patients. Such a study in couples with fertility problems can inform choices between treatments; it is then the management protocol which is the subject of the investigation, not the individual treatments. Couples (N=77) with one or both partners ANXA5 M2 positive demo...
BackgroundMinimally invasive plate osteosynthesis (MIPO) becomes popular for treating distal tibi... more BackgroundMinimally invasive plate osteosynthesis (MIPO) becomes popular for treating distal tibia fractures. Intra-articular extension was accused for result deterioration and was considered as an indication for open reduction and internal fixation (ORIF). Our hypothesis was that the simple intra-articular extension can be successfully treated percutaneously, MIPO can be successfully applied, and ORIF is not mandatory. We wanted to determine whether the presence of simple articular extension would change the reported excellent results of MIPO after 5 years follow-up.Patients and methodsAs extensive articular affection has different treatment strategies, the inclusion criteria for this prospective clinical series included distal tibia fractures with only simple intra-articular extension (AO/OTA 43-B1, B2, C1, and C2). From 43 patients we treated with MIPO using the AO medial distal tibia anatomical locked plate, 13 patients were excluded as they did not complete the follow-up, and only 30 patients were reported. Only seven fractures were open. The minimum follow-up period was 5 years. The outcome measurements included fracture healing, alignment, nonunion, infection, ankle range of motion (ROM), implant removal, ankle osteoarthritis (OA), unemployment, failure to return to daily activities or sports, and functional assessment as per the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale.ResultsAll the fractures united, but with delay in two patients. No articular step-off more than 2 mm could be detected in any patient. At the metaphysis, three patients (10 %) had angular deformities less than 5°, uni-planar in two patients and bi-planar in one patient. Three patients (10 %) developed a superficial infection. These three patients had their implants removed and had reduced ankle ROM. Twenty-eight patients (93.33) returned to their original job. Twenty-four patients (80 %) had returned to their pre-injury daily activity and sports. At the end of follow-up, no patient developed ankle osteoarthritis or had deterioration of his earlier satisfactory clinical and functional results. The mean AOFAS score was 90.8 ± 6 at the end of follow-up.ConclusionsAfter 5 years follow-up, MIPO was an excellent option for the challenging distal tibia fractures even with simple articular extension. With absence of OA, high percentage of the patients could keep excellent functional results, job, and activity.
Introduction: In spite of introduction of intermediate-acting neuromuscular blocking drugs (NMBDs... more Introduction: In spite of introduction of intermediate-acting neuromuscular blocking drugs (NMBDs), incidence of postoperative residual muscle weakness is still high. The aim of this trial is to study the effect of systemic lidocaine infusion on intraoperative consumption of rocuronium and TOF ratios at extubation and on arrival to postanesthesia care unit (PACU). Methods: Forty-six ASA I-III patients aged 16-60 yr were randomly allocated into two groups: lidocaine (L) group (n = 23) and control (C) group (n = 23). After induction of standard endotracheal general anesthesia with fentanyl, propofol and rocuronium, patients of group L were given i.v. lidocaine bolus (1.5 mg kg À1) followed by continuous infusion (1.5 mg kg À1 h À1) till time of endotracheal extubation while patients in group C were given equal volumes of normal saline. Rocuronium was titrated based on clinical signs. On conclusion of surgery, neostigmine was given to reverse the effects of rocuronium if TOF count was two or more. Immediately before extubation, TOF ratio was measured and recorded and considered the primary outcome. Results: There were no significant differences between the two study groups regarding intraoperative fentanyl doses or core temperature at the end of surgery. End-tidal sevoflurane concentrations were significantly lower in group L than in group P (P < 0.01). The dose of rocuronium was significantly less in group L than in group C (P = 0.001). Train-of four ratios were significantly higher in group L than in group C either before extubation (P < 0.001) or on arrival to PACU (P = 0.001). Conclusion: The current study shows that intraoperative use of i.v. lidocaine infusion in generally anesthetized patients can result in higher TOF ratios at time of extubation and on arrival to PACU when rocuronium was given based on clinical signs.
The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is carried on the CALIPSO satellite... more The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is carried on the CALIPSO satellite and has acquired global aerosol profiles since June 2006. CALIPSO is flown in formation with the Aqua satellite as part of the A-train satellite constellation, so that a large number of coincident aerosol observations are available from CALIOP and the MODIS-Aqua instrument. This study compares column aerosol optical depth at 0.532 µm derived from CALIOP aerosol profiles with MODIS-Aqua 0.55 µm aerosol optical depth over the period June 2006 through August 2008. The study is based on the CALIOP Version 2 Aerosol Layer Product and MODIS Collection 5. While CALIOP is first and foremost a profiling instrument, this comparison of column aerosol optical depth provides insight into quality of CALIOP aerosol data. It is found that daytime aerosol optical depth from the CALIOP Version 2 product has a small global mean bias relative to MODIS Collection 5. Regional biases, of both signs, are larger and biases are seen to vary somewhat with season. In northern mid-latitudes, aerosol optical depth from CALIOP is lower, on average, than from MODIS. This may be partly due to a latitude-dependent calibration error in Version 2 CALIOP Level 1 daytime 0.532 µm profiles. This comparison of CALIOP and MODIS also provides insight into possible biases in the MODIS aerosol optical depth product due to cloud masking and errors in modeling land surface reflectance.
Introduction: Systemic administration of lidocaine significantly decreased propofol requirements ... more Introduction: Systemic administration of lidocaine significantly decreased propofol requirements when compared to patients receiving placebo. Several studies conducted on animals have proved that systemic local anesthetics reduced minimum alveolar concentration (MAC) of inhalational anesthetics. The aim of this investigation is to study the effect of intravenous administration of lidocaine on the minimum alveolar concentration of sevoflurane required to keep BIS between 40 and 60 during maintenance of anesthesia in humans. Methods: Twenty-eight ASA I-II adults planned to undergo laparoscopic procedures expected to last <2 h under general anesthesia were randomly assigned to 2 groups. After standardized induction of general anesthesia, patients were given IV lidocaine bolus (1.5 mg kg À1) followed by 2 mg kg À1 h À1 infusion (group L, n = 14) or equal volumes of saline (group C, n = 14). Primary outcome of the study was end-tidal sevoflurane at bispectral index (BIS) values of 40-60. Secondary outcomes included doses of opioids, BIS values, and extubation time. Results: The median doses of intraoperative fentanyl (range) in group C were similar to group L (P = 0.08). There were no significant differences between the 2 groups regarding BIS at any time point. End-tidal sevoflurane concentrations were significantly higher in group C than in group L at all intraoperative time points (P < 0.05). Extubation time was longer in group L than in group C (P = 0.04).
To determine whether peripheral diabetic retinopathy (DR) lesions identified on ultrawide field (... more To determine whether peripheral diabetic retinopathy (DR) lesions identified on ultrawide field (UWF) imaging are associated with increased DR progression. Prospective, longitudinal cohort. Two hundred eyes of 100 participants previously enrolled in a comparative instrument validation study. Baseline mydriatic 7-standard field Early Treatment Diabetic Retinopathy Study (ETDRS) photographs and UWF images were obtained. On UWF images, DR lesions with a greater extent outside versus inside standard ETDRS fields were defined as predominantly peripheral lesions (PPLs). Follow-up ETDRS photographs were obtained 4.2±0.3 years after baseline. Baseline and follow-up DR severity were graded from ETDRS photographs. Rates of 2-step or more progression and progression to proliferative DR (PDR) in eyes with PPLs compared with eyes without PPLs identified on UWF imaging at baseline. In eyes without PDR (n = 109) at baseline, 56 (51%) had at least 1 field with PPLs and 43 (39%) had DR progression. ...
Background: This study was designed to compare magnesium sulphate with dexmedetomidine, regarding... more Background: This study was designed to compare magnesium sulphate with dexmedetomidine, regarding their efficiency in inducing deliberate hypotension and providing a better surgical field exposure during middle ear surgery. It also compared the influence of their use on postoperative pain and recovery time. Methods: Eighty-eight adult patients undergoing middle ear surgery were included. Patients were randomly divided into two equal groups. Patients were assigned to receive either magnesium sulphate (M group) or dexmedetomidine (D group). Anaesthesia was induced by propofol 2 mg/kg iv and fentanyl 1 lg/kg. Patients in the M group received an iv bolus of magnesium sulphate 50 mg/kg in a total of 100 ml saline over 10 min followed by infusion of 15 mg/kg/h until the end of surgery. Similarly, patients in the D group received dexmedetomidine 1 lg/kg over 10 min followed by 0.4-0.8 lg/kg/h until the end of operation. The target MAP during operation was
Background: Use of adjuncts to local anesthetics is believed to enhance the quality and duration ... more Background: Use of adjuncts to local anesthetics is believed to enhance the quality and duration of the peripheral nerve blocks. We tested the hypothesis that addition of ketamine or tramadol to bupivacaine 0.5% in PVB for patients undergoing modified radical mastectomy would enhance postoperative analgesia. Methods: We prospectively randomized 60 ASA I-III women into three groups: group B (n = 20) who received PVB using plain bupivacaine 0.5% (control group), group K (n = 21) who received ketamine (0.5 mg kg À1) added to bupivacaine 0.5%, and group T (n = 19) who received tramadol (1.5 mg kg À1) added to bupivacaine 0.5%. All the patients were then given a standardized general anesthesia. Primary outcome was the cumulative fentanyl dose given through patient-controlled analgesia (PCA) device in the first 24 h after surgery. Secondary outcomes included dose of fentanyl in the postanesthesia care unit (PACU), time to first dose of fentanyl, and visual analogue scale (VAS) pain scores in PACU and ward.
2018 9th International Renewable Energy Congress (IREC), 2018
DC current offset severally affects the distribution system components such as; isolation transfo... more DC current offset severally affects the distribution system components such as; isolation transformers, measurement units and protective relays. Various DC current offset compensation techniques hypothetically are suitable to compensate DC current injected by grid connected inverters This paper presents a technique to stifle DC current injection into the AC grid which can be applied to medium-scale solar farms or any gathering of lattice connected inverters restricted to a moderately little zone. The importance of this system is that it does not depend on high current measurement devices and does not utilize any type of complex transformers. Also, it permits an operation without transformer for all inverters inside the solar farm and there must be at least one inverter to perform DC offset compensation in addition to its essential function of active power interfacing into the AC grid. This inverter is needed to substitute all DC offsets that can be found in the solar farm current before reaching the main interfacing transformer, therefore we can avoid the hazard of transformer saturation.
International Journal of Innovative Research in Science, Engineering and Technology, 2015
This paper presents evaluation of effect of in-wheel electric motors mass on the performance of a... more This paper presents evaluation of effect of in-wheel electric motors mass on the performance of active suspension system by using one of more common control methods which is Linear Quadratic Regulator (LQR).Unsprung mass is one of the important parameters which effects on road holding and ride comfort behaviors in the vehicles, this effect obtained in this work by comparing the performance of the system using standard tire and tire with In-Wheel Electric Motor. Also,modeling and simulation of quarter car model completed to construct the Simulink model of the system using MATLAB software. The study summarized bad effect of increasing the weight of tires by add In-Wheel Motors to the system on the road traction and the vehicles drivers comfort, at the same time the suspension system with in-wheel motor needs high actuator force to work compared to the same system without inwheel motor
Introduction: This Study has was carried out to measure and detect the natural occurred radionuc... more Introduction: This Study has was carried out to measure and detect the natural occurred radionuclide content including 226Ra, 232Th and 40K in the Nile River sediments at various locations in Upper Egypt, from Aswan to El-Minya. Additionally, we determine the absorbed dose rate, the annual effective dose equivalent, and excess lifetime cancer risk also has been calculated. Material and Methods: The gamma ray measurements were performed with a high resolution High-Purity Germanium detector, low background, and Personal Computer multichannel analyzer. Results: In Aswan Governorate, the mean specific activities of radionuclide's (226Ra,232Th and 40K) 14.86, 13.78 and 175.4 in Bq/kg respectively. In Qena Governorate, the mean specific activities of mentioned radionuclides were 14.44 Bq/kg, 15.02 Bq/kg and 197.57 Bq/kg, respectively. These values were18.53 Bq/kg, 11.3 Bq/kg and 184.73 Bq/kg in Sohag Governorate, respectively. In Asyut Governorate the mean specific activities of t...
This paper presents a Li-ion battery storage system provided with a supercapacitor as a backup mi... more This paper presents a Li-ion battery storage system provided with a supercapacitor as a backup micro-fuel interface scheme to AC/DC power system that can be utilized during maximum demand circumstances. Distributed flexible AC transmission system (D-FACTS) based–switched filter compensator (SFC) scheme is proposed to ensure energy efficient of battery charging scheme. A dynamic multi-level error-driven control strategy is proposed to guarantee better power quality performance in terms of fast charging of the battery storage system, voltage enhancement and stabilization of the DC and AC buses, improvement of power factor of AC buses, inrush current minimization and harmonic current distortion reduction. The proposed SFC is controlled by means of a multi-level functional error-driven intercoupled weighted modified proportional-integralderivative (WM-PID) controller. Grey wolf optimization is employed for tuning PID controller gains in terms of change at state of charge (SOC) and to re...
A glaucoma is a group of eye conditions that damage the optic nerve, which is vital to good visio... more A glaucoma is a group of eye conditions that damage the optic nerve, which is vital to good vision and if not detected early eventually leads to irreversible blindness. Primary open-angle glaucoma the most common type of glaucoma which occurs due to an imbalance of the eye liquid drainage and production. Although, Primary open-angle glaucoma's optic neuropathic nature which features retinal ganglionic cell loss representing the most prevalent form of glaucoma, its exact a etiology and pathogenesis are unknown. Numerous studies have reported the genetic factor that contributes to the progression of POAG including molecular changes in the trabecular meshwork causing stiffness eventually leading to increased intraocular pressure. Therefore, studying the genetic factors and other causes of POAG could help lead to early diagnosis and eventually slow the progression of the disease. However, to this very day, several gene mutations have been described and established to be the causative factors of POAG with some genetic analyses including genomewide association studies. In this review, we will be focusing on the factors that contribute to the pathology of POAG and the damages that occur to the visual cortex.
IEEE Open Journal of Antennas and Propagation, 2020
The design of a low-profile wideband shared-aperture dual-polarized antenna is proposed. The prop... more The design of a low-profile wideband shared-aperture dual-polarized antenna is proposed. The proposed antenna consists of a cavity-backed slot antenna to produce vertical polarization and a slot-backed monopole antenna for horizontal polarization. The slot operates as a radiator for vertical polarization and at the same time, it works as a reflector for horizontal polarization. Two antenna prototypes are designed and simulated. The initial design has a profile of 0.28λ max , where λ max is the free space wavelength at the lowest frequency. The vertical and horizontal polarized antennas exhibit 36.1% and 39.7% bandwidths, respectively. By adding a notch in the slot, the current path increases, which reduces the operating frequency band; hence, the low-profile design is accomplished. The new version features a profile of 0.17λ max with 28.2% and 36% bandwidths for vertical and horizontal polarizations, respectively. The low-profile prototype is fabricated and measured. The measured S-parameters are consistent with the simulated one. The measured realized gain varies from 1 to 4.2 dBi for vertical polarization, while it varies from 1 to 2.5 dBi for horizontal polarization. The total efficiency of the proposed antenna is above 85% within the operating band for both polarizations. The far-field radiation pattern is measured, and a good agreement is achieved with the simulated one.
Suez Canal Veterinary Medicine Journal. SCVMJ, 2016
A total number of 77 marine fishes of 3 species represented as 23 Abu Sabib (), 24 kosher Abu L... more A total number of 77 marine fishes of 3 species represented as 23 Abu Sabib (), 24 kosher Abu Lolo (Epinephelus fasciatus) and 30 Sigan (Siganusluridus) were collected seasonally between May 2014 and the end of April 2015 from coral reef sites along the shore of the National Institute of Oceanography and Fisheries (NIOF) at Hurghada's Red sea. They were investigated for detection of parasitic copepods. It was revealed that 31.16% of the examined marine fishes were infested. The detected species were belong to Genus Hatschekia Poche1902 from with a prevalence78.26%, and from Siganus luridus with prevalence 20% while not detected in Epinephelus fasciatus. The total and seasonal prevalence of infestation in each fish species in relation to body weights and lengths were recorded. Besides, the histopathological alterations were studied and discussed.
Thermal neutron detectors, which are based on semiconductor material such as silicon coated with ... more Thermal neutron detectors, which are based on semiconductor material such as silicon coated with neutron reactive material like 6 LiF have been discussed for many decades. The performance of the thermal neutron detector system, GAMBE (GAMma Blind neutron Efficient), which is based on two silicon sensors in a sandwich configuration is investigated. This detector is able to achieve a total and a coincidence detection efficiency of 4% and ∼1% respectively. The thermal neutron detection efficiency of the detector is enhanced by using a stacked detector configuration and high-density polyethylene (HDPE) sheets, as neutron moderators and reflectors. The GAMBE detector is positioned inside a box of HDPE with a lead window in the direction of the neutron flux for neutron moderation and a reduction of the effect of gamma-rays on the detector. The experimental layout was modeled in MCNP4C to investigate the contribution of HDPE to the thermal neutron flux (n/s/cm 2). In this research a stack of 4 silicon semiconductor sensors with (2.6±0.6) and (2.9±0.6) mg/cm 2 thick 6 LiF film in a configuration of two sandwiches is shown to achieve a total and a coincidence detection efficiency of 27% and 4% respectively. This represents a significant improvement compared to a single detector. The effect of these stacked detectors for the development of a handheld thermal neutron detector, using 4 coated Si detectors is shown to have a 22% efficiency. This information is used to inform the optimised design of the handheld detector. The results based on geant4 and MCNP simulations indicate that the total detection efficiency of this portable detector with a stack of 7 sandwich detectors will increase up to 52% by using an optimal thickness of 6 LiF of 3.95 mg/cm 2 .
As fundamental importance to SEM observation of specimen surface, secondary electron generation a... more As fundamental importance to SEM observation of specimen surface, secondary electron generation and emission processes have been studied by a Monte Carlo method. The simulation is based on a discrete description of cascade secondary electron production. The Monte Carlo model combines the use of Mott's cross section for electron elastic scattering and of Penn's dielectric function for electron inelastic scattering. Two models of dielectric function, i.e. the single pole approximation and the full Penn algorithm, are shown to give energy distribution and yield of secondary electrons in agreement with experimental results for non-free electron materials and free electron metals, respectively. We use a constructive solid geometry modeling to describe sample 3D geometry and a Gaussian function to describe random surface roughness. The technique is efficient and powerful in a simulation of SEM images of secondary electrons and backscattered electrons for a quite complex geometry of nanostructures. Finally we present the depth distribution functions for secondary electron generation and emission. Their dependences on primary energy and atomic numbers are analyzed. Furthermore, we shall also discuss a general issue of depth distribution function for rough surfaces.
The International Conference on Chemical and Environmental Engineering, 2012
The changes of optical and electrical properties of aniline hydrochloride/polyvinyl alcohol films... more The changes of optical and electrical properties of aniline hydrochloride/polyvinyl alcohol films (AN/PVA) influenced by gamma radiation for the purpose of gamma dosimetry are presented in this work. Optically, by exposing films to doses of gamma radiation from 0 to 10 kGy, films showed visually apparent gradual change in color from violet to yellow green with increase of absorbance at 424 nm. Electrical, conductivity also was increased regularly in the same dose range. It can be suggested that aniline hydrochloride in the AN/PVA form may be used for dosimetry for the mentioned dose range.
The International Conference on Chemical and Environmental Engineering, 2010
In this study, Tartarzine aqueous solution was investigated as a simple low-dose dosimeter in the... more In this study, Tartarzine aqueous solution was investigated as a simple low-dose dosimeter in the range of 20-500 Gy for the high ionizing radiation, gamma ray. Gradual bleaching of Tartarzine solution was observed with dose by measuring the absorbance of Tartarzine-solutions at specified wavelength, λ max = 430 nm. Tartarzine concentration (10-4 , 5 ×10-4 and 10-3 M) and solution-initial pH value (5, 7 and 9) were considered as factors affecting degree of bleaching. It was found that Tartarzinesolution color was diminished gradually with selected dose range. The rate of bleaching increases with the increase of solution-initial pH. Increase of Tartarzineconcentration causes widening of range to which solution is susceptible. The postirradiated effect (24 hours) was found to cause more bleaching. The sensitivity of Tartarzine solution is not regular with the Tartarzine-concentration and regular with pH.
International Conference on Aerospace Sciences and Aviation Technology, 2015
In the present work, aniline doped aluminum oxide films were prepared by the Sol-Gel technique fo... more In the present work, aniline doped aluminum oxide films were prepared by the Sol-Gel technique for gamma radiation dosimetry. Aniline (AN) was suggested to enhance the electrical conductivity of films. Measured conductivity due to gamma radiation was studied in the 0-10 kGy dose range. Conductivity was enhanced with AN doping. Conductivity and sensitivity values up to 150 (µΩ-1 .cm-1) and 3.75 (mA.cm ــ 2ــ .kGy ــ 1ــ) respectively were achieved at 0.25 g AN content and 25 V bias.
Pregnancy failure and placenta mediated pregnancy complications affect >25% of pregnancies. Al... more Pregnancy failure and placenta mediated pregnancy complications affect >25% of pregnancies. Although there is biological plausibility for a procoagulant mechanism underlying some of these events, antithrombotic intervention trials demonstrate limited benefit, possibly through lack of stratification in heterogeneous patient groups. The ANXA5 M2 haplotype is a possible procoagulant biomarker and was tested pragmatically to determine whether this screening and LMWH treatment normalized the outcome for ANXA5 M2 positive couples. This was a pragmatic study that aimed to measure the effectiveness of a testing (for the M2 haplotype) and treatment (LMWH) pathway in routine clinical practice where there is variation between patients. Such a study in couples with fertility problems can inform choices between treatments; it is then the management protocol which is the subject of the investigation, not the individual treatments. Couples (N=77) with one or both partners ANXA5 M2 positive demo...
BackgroundMinimally invasive plate osteosynthesis (MIPO) becomes popular for treating distal tibi... more BackgroundMinimally invasive plate osteosynthesis (MIPO) becomes popular for treating distal tibia fractures. Intra-articular extension was accused for result deterioration and was considered as an indication for open reduction and internal fixation (ORIF). Our hypothesis was that the simple intra-articular extension can be successfully treated percutaneously, MIPO can be successfully applied, and ORIF is not mandatory. We wanted to determine whether the presence of simple articular extension would change the reported excellent results of MIPO after 5 years follow-up.Patients and methodsAs extensive articular affection has different treatment strategies, the inclusion criteria for this prospective clinical series included distal tibia fractures with only simple intra-articular extension (AO/OTA 43-B1, B2, C1, and C2). From 43 patients we treated with MIPO using the AO medial distal tibia anatomical locked plate, 13 patients were excluded as they did not complete the follow-up, and only 30 patients were reported. Only seven fractures were open. The minimum follow-up period was 5 years. The outcome measurements included fracture healing, alignment, nonunion, infection, ankle range of motion (ROM), implant removal, ankle osteoarthritis (OA), unemployment, failure to return to daily activities or sports, and functional assessment as per the American Orthopedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale.ResultsAll the fractures united, but with delay in two patients. No articular step-off more than 2 mm could be detected in any patient. At the metaphysis, three patients (10 %) had angular deformities less than 5°, uni-planar in two patients and bi-planar in one patient. Three patients (10 %) developed a superficial infection. These three patients had their implants removed and had reduced ankle ROM. Twenty-eight patients (93.33) returned to their original job. Twenty-four patients (80 %) had returned to their pre-injury daily activity and sports. At the end of follow-up, no patient developed ankle osteoarthritis or had deterioration of his earlier satisfactory clinical and functional results. The mean AOFAS score was 90.8 ± 6 at the end of follow-up.ConclusionsAfter 5 years follow-up, MIPO was an excellent option for the challenging distal tibia fractures even with simple articular extension. With absence of OA, high percentage of the patients could keep excellent functional results, job, and activity.
Introduction: In spite of introduction of intermediate-acting neuromuscular blocking drugs (NMBDs... more Introduction: In spite of introduction of intermediate-acting neuromuscular blocking drugs (NMBDs), incidence of postoperative residual muscle weakness is still high. The aim of this trial is to study the effect of systemic lidocaine infusion on intraoperative consumption of rocuronium and TOF ratios at extubation and on arrival to postanesthesia care unit (PACU). Methods: Forty-six ASA I-III patients aged 16-60 yr were randomly allocated into two groups: lidocaine (L) group (n = 23) and control (C) group (n = 23). After induction of standard endotracheal general anesthesia with fentanyl, propofol and rocuronium, patients of group L were given i.v. lidocaine bolus (1.5 mg kg À1) followed by continuous infusion (1.5 mg kg À1 h À1) till time of endotracheal extubation while patients in group C were given equal volumes of normal saline. Rocuronium was titrated based on clinical signs. On conclusion of surgery, neostigmine was given to reverse the effects of rocuronium if TOF count was two or more. Immediately before extubation, TOF ratio was measured and recorded and considered the primary outcome. Results: There were no significant differences between the two study groups regarding intraoperative fentanyl doses or core temperature at the end of surgery. End-tidal sevoflurane concentrations were significantly lower in group L than in group P (P < 0.01). The dose of rocuronium was significantly less in group L than in group C (P = 0.001). Train-of four ratios were significantly higher in group L than in group C either before extubation (P < 0.001) or on arrival to PACU (P = 0.001). Conclusion: The current study shows that intraoperative use of i.v. lidocaine infusion in generally anesthetized patients can result in higher TOF ratios at time of extubation and on arrival to PACU when rocuronium was given based on clinical signs.
The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is carried on the CALIPSO satellite... more The Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) is carried on the CALIPSO satellite and has acquired global aerosol profiles since June 2006. CALIPSO is flown in formation with the Aqua satellite as part of the A-train satellite constellation, so that a large number of coincident aerosol observations are available from CALIOP and the MODIS-Aqua instrument. This study compares column aerosol optical depth at 0.532 µm derived from CALIOP aerosol profiles with MODIS-Aqua 0.55 µm aerosol optical depth over the period June 2006 through August 2008. The study is based on the CALIOP Version 2 Aerosol Layer Product and MODIS Collection 5. While CALIOP is first and foremost a profiling instrument, this comparison of column aerosol optical depth provides insight into quality of CALIOP aerosol data. It is found that daytime aerosol optical depth from the CALIOP Version 2 product has a small global mean bias relative to MODIS Collection 5. Regional biases, of both signs, are larger and biases are seen to vary somewhat with season. In northern mid-latitudes, aerosol optical depth from CALIOP is lower, on average, than from MODIS. This may be partly due to a latitude-dependent calibration error in Version 2 CALIOP Level 1 daytime 0.532 µm profiles. This comparison of CALIOP and MODIS also provides insight into possible biases in the MODIS aerosol optical depth product due to cloud masking and errors in modeling land surface reflectance.
Introduction: Systemic administration of lidocaine significantly decreased propofol requirements ... more Introduction: Systemic administration of lidocaine significantly decreased propofol requirements when compared to patients receiving placebo. Several studies conducted on animals have proved that systemic local anesthetics reduced minimum alveolar concentration (MAC) of inhalational anesthetics. The aim of this investigation is to study the effect of intravenous administration of lidocaine on the minimum alveolar concentration of sevoflurane required to keep BIS between 40 and 60 during maintenance of anesthesia in humans. Methods: Twenty-eight ASA I-II adults planned to undergo laparoscopic procedures expected to last <2 h under general anesthesia were randomly assigned to 2 groups. After standardized induction of general anesthesia, patients were given IV lidocaine bolus (1.5 mg kg À1) followed by 2 mg kg À1 h À1 infusion (group L, n = 14) or equal volumes of saline (group C, n = 14). Primary outcome of the study was end-tidal sevoflurane at bispectral index (BIS) values of 40-60. Secondary outcomes included doses of opioids, BIS values, and extubation time. Results: The median doses of intraoperative fentanyl (range) in group C were similar to group L (P = 0.08). There were no significant differences between the 2 groups regarding BIS at any time point. End-tidal sevoflurane concentrations were significantly higher in group C than in group L at all intraoperative time points (P < 0.05). Extubation time was longer in group L than in group C (P = 0.04).
To determine whether peripheral diabetic retinopathy (DR) lesions identified on ultrawide field (... more To determine whether peripheral diabetic retinopathy (DR) lesions identified on ultrawide field (UWF) imaging are associated with increased DR progression. Prospective, longitudinal cohort. Two hundred eyes of 100 participants previously enrolled in a comparative instrument validation study. Baseline mydriatic 7-standard field Early Treatment Diabetic Retinopathy Study (ETDRS) photographs and UWF images were obtained. On UWF images, DR lesions with a greater extent outside versus inside standard ETDRS fields were defined as predominantly peripheral lesions (PPLs). Follow-up ETDRS photographs were obtained 4.2±0.3 years after baseline. Baseline and follow-up DR severity were graded from ETDRS photographs. Rates of 2-step or more progression and progression to proliferative DR (PDR) in eyes with PPLs compared with eyes without PPLs identified on UWF imaging at baseline. In eyes without PDR (n = 109) at baseline, 56 (51%) had at least 1 field with PPLs and 43 (39%) had DR progression. ...
Background: This study was designed to compare magnesium sulphate with dexmedetomidine, regarding... more Background: This study was designed to compare magnesium sulphate with dexmedetomidine, regarding their efficiency in inducing deliberate hypotension and providing a better surgical field exposure during middle ear surgery. It also compared the influence of their use on postoperative pain and recovery time. Methods: Eighty-eight adult patients undergoing middle ear surgery were included. Patients were randomly divided into two equal groups. Patients were assigned to receive either magnesium sulphate (M group) or dexmedetomidine (D group). Anaesthesia was induced by propofol 2 mg/kg iv and fentanyl 1 lg/kg. Patients in the M group received an iv bolus of magnesium sulphate 50 mg/kg in a total of 100 ml saline over 10 min followed by infusion of 15 mg/kg/h until the end of surgery. Similarly, patients in the D group received dexmedetomidine 1 lg/kg over 10 min followed by 0.4-0.8 lg/kg/h until the end of operation. The target MAP during operation was
Background: Use of adjuncts to local anesthetics is believed to enhance the quality and duration ... more Background: Use of adjuncts to local anesthetics is believed to enhance the quality and duration of the peripheral nerve blocks. We tested the hypothesis that addition of ketamine or tramadol to bupivacaine 0.5% in PVB for patients undergoing modified radical mastectomy would enhance postoperative analgesia. Methods: We prospectively randomized 60 ASA I-III women into three groups: group B (n = 20) who received PVB using plain bupivacaine 0.5% (control group), group K (n = 21) who received ketamine (0.5 mg kg À1) added to bupivacaine 0.5%, and group T (n = 19) who received tramadol (1.5 mg kg À1) added to bupivacaine 0.5%. All the patients were then given a standardized general anesthesia. Primary outcome was the cumulative fentanyl dose given through patient-controlled analgesia (PCA) device in the first 24 h after surgery. Secondary outcomes included dose of fentanyl in the postanesthesia care unit (PACU), time to first dose of fentanyl, and visual analogue scale (VAS) pain scores in PACU and ward.
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Papers by Ahmed Ali Omar