Metamaterial analysis for microwave frequencies is a common practice. However, adopting a multi-l... more Metamaterial analysis for microwave frequencies is a common practice. However, adopting a multi-layered design is unique in the concept of miniaturisation, thus requiring extensive research for optimal performance. This study focuses on a multi-layered symmetric metamaterial design for C- and X-band applications. All simulation analyses were performed analytically using Computer Simulation Technology Studio Suite 2019. The performances of the proposed metamaterial design were analysed through several parametric studies. Based on the observation, the proposed metamaterial unit cell design manifested resonant frequencies at 7.63 GHz (C-band) and 9.56 GHz (X-band). Moreover, the analysis of effective medium parameters was also included in this study. High-Frequency Simulation 15.0 and Advanced Design System 2020 software validated the transmission coefficient results. Simultaneously, the proposed multi-layered metamaterial design with Rogers RO3006 substrate material exhibited a unique...
A commercially viable metal–dielectric–metal configured triple-band metamaterial absorber is offe... more A commercially viable metal–dielectric–metal configured triple-band metamaterial absorber is offered in this paper. It is an aggregation of four compact symmetric circles, with a swastika-shaped metal structure, which are bonded by two split-ring resonators (SRRs). Copper (annealed) of electrical conductivity 5.8 × 107 Sm−1 is used for the ground plate and resonator portion of the top layer and an FR 4 dielectric of permittivity 4.3 is used as a substrate. The structural parameters of the unit cell were determined by a trial and error method. FIT-based 3D simulation software (CST microwave studio, 2019 version was used to characterize the proposed perfect metamaterial absorber (PMA). Three resonance peaks were observed at frequencies 3.03, 5.83 and 7.23 GHz with an absorbance of 99.84%, 99.03% and 98.26%, respectively. The numerical result has been validated by some authentic validation methods. Finally, a microwave network analyzer (PNA) of Agilent N5227 with waveguide ports were d...
A split-ring resonator (SRR)-based power tiller wheel-shaped quad-band ℇ-negative metamaterial is... more A split-ring resonator (SRR)-based power tiller wheel-shaped quad-band ℇ-negative metamaterial is presented in this research article. This is a new compact metamaterial with a high effective medium ratio (EMR) designed with three modified octagonal split-ring resonators (OSRRs). The electrical dimension of the proposed metamaterial (MM) unit cell is 0.086λ × 0.086λ, where λ is the wavelength calculated at the lowest resonance frequency of 2.35 GHz. Dielectric RT6002 materials of standard thickness (1.524 mm) were used as a substrate. Computer simulation technology (CST) Microwave Studio simulator shows four resonance peaks at 2.35, 7.72, 9.23 and 10.68 GHz with magnitudes of −43.23 dB −31.05 dB, −44.58 dB and −31.71 dB, respectively. Moreover, negative permittivity (ℇ) is observed in the frequency ranges of 2.35–3.01 GHz, 7.72–8.03 GHz, 9.23–10.02 GHz and 10.69–11.81 GHz. Additionally, a negative refractive index is observed in the frequency ranges of 2.36–3.19 GHz, 7.74–7.87 GHz, 9...
In this article, we present the use of a metamaterial-incorporated microwave-based sensor with a ... more In this article, we present the use of a metamaterial-incorporated microwave-based sensor with a single port network for material characterization. The proposed sensor consists of a microstrip patch layer enclosed with a dual-square-shaped metamaterial split-ring. This structure has the dimensions of 20 × 20 × 1.524 mm3 and a copper metallic layer is placed on a Rogers RT 6002 with a partial back layer as a ground. Two resonant frequencies are exhibited for applied electromagnetic interaction using a transmission line. The dual split rings increase the compactness and accumulation of the electromagnetic field on the surface of the conducting layer to improve the sensitivity of the sensor. The numerical studies are carried out using a CST high-frequency microwave simulator. The validation of the proposed sensor is performed with an equivalent circuit model in ADS and numerical high-frequency simulator HFSS. The material under test placed on the proposed sensor shows good agreement wi...
Despite their widespread use for performing advanced electromagnetic properties, metamaterial suf... more Despite their widespread use for performing advanced electromagnetic properties, metamaterial suffers from several restrictions in this technological era. Generally, technology affects the way individuals communicate, learn, think and plays an important role in society today. For this reason, there has been a surge of interest in a coding metamaterial field that possesses the ability to manipulate electromagnetic waves and realize different functionalities. This research work investigates circular-shaped coding metamaterial for microwave frequency applications through several analyses. First, the 1-bit coding metamaterial that is made up of only "0" and "1" elements with 0 and π phase responses by adopting two types of unit cells such as square-shaped Rogers RT6002 substrate material with and without metamaterial structure were analysed in this work. The proposed element '1' successfully manifests several more than 180○ phase responses at several frequency ranges, for instance, 7.35 to 9.48 GHz, 12.87 to 14.25 GHz and 17.49 to 18 GHz (C, X, and Ku-bands), respectively. Besides that, three types of coding sequences were proposed and the radar cross-section (RCS) reduction values of the designs were numerically calculated by utilising Computer Simulation Technology (CST) software. Meanwhile, the single-layered coding metamaterial with 6 lattices was compared with double and triple-layered metamaterial structures. At 2 GHz, the triple-layered structure exhibit reduced RCS values with near to − 30 dBm 2 for all coding sequences. Therefore, the transmission coefficient results of the triple-layered coding metamaterial sequences were numerically calculated. Several advanced coding metamaterial designs were constructed and the properties were discussed in terms of RCS values and scattering patterns. Meanwhile, the scattering and effective medium parameters of the unit cell metamaterial structure were also analysed in this work. In a nutshell, the 1-bit coding metamaterial in a controlled sequence can control electromagnetic waves and realize different functionalities. Research investigations regarding metamaterial have become familiar among the scientific community in the past few decades. Potential applications of metamaterial are diverse and include electromagnetic absorption reduction, sensor, terahertz frequency application, metamaterial filter, metamaterial absorption, etc. are successfully adapted metamaterial design structures to gain unique results 1-5. Generally, the metamaterial design structure has its unique way of light interacting when compared to conventional materials. Conventional material can be easier found in nature but lacks in producing extraordinary electromagnetic properties. For instance, left-handed behaviour is very possible in man-made design structures instead of conventional materials. However, the current advanced technology is required beyond normal metamaterial structure design to optimise the performance to utilise in many application fields. Moreover, for specific applications likely metamaterial antenna, the conventional material is difficult to manufacture in large quantities. Meanwhile, the metamaterial absorption commonly has a very low narrow absorption band and shows a dispersion phenomenon outstandingly in the far-infrared domain. Therefore, many new concepts and ideas are developed in recent years such as metasurface, mechanical metamaterial, photonic metamaterial, acoustic metamaterial, plasmonic metamaterial, etc.
In this research work, the development of the metamaterial unit cell is used to investigate multi... more In this research work, the development of the metamaterial unit cell is used to investigate multifunctional characteristics, exhibit preferable and capable adjustability, reconfigurable by changing the phase response of applied electromagnetic wave. This proposed metamaterial unit cell is analysed by modifying the geometric design of the metallic structure which mitigates the design to reduce the cost for the commercialisation. The resonant frequencies are located from 1.87, 2.55, 4.32, 5.46 GHz. The interaction with the electric field and magnetic field exhibit the polarisation in both planes which enhances the left handed characteristics. The field distribution of electric, magnetic, and surface current is presented with vector fields in different planes to observe the polarisation state. Different thicknesses of dielectric material are utilised to observe the impact of time varying electric and magnetic fields through the proposed metamaterial. The different substrate materials a...
Introduccion: El desarrollo pulmonar, proceso complejo y altamente organizado, constituye una a... more Introduccion: El desarrollo pulmonar, proceso complejo y altamente organizado, constituye una atractiva y dinamica area de investigacion constante. Metodologia: estudio descriptivo, transversal y correlacional realizado en nueve embriones humanos de semana ocho, pertenecientes a la Embrioteca de la facultad de Medicina de Villa Clara. Los especimenes se procesaron histologicamente por tecnica de parafina, procedentes de interrupcion del embarazo por Misoprostol, digitalizados sus cortes y medidos las secciones seriadas de los pulmones mediante las opciones de area y distancia del software Escopephoto 3.0; para el calculo del volumen se empleo el espesor del corte multiplicado por la sumatoria de areas parciales. Se utilizo la prueba de Mann-Whitney para la comparacion de volumenes. Resultados: la semana estudiada encontramos que los pulmones tuvieron predominio longitudinal y en el mismo eje hicieron sus mayores incrementos, el pulmon izquierdo incremento menos su eje lateral con...
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Phosphate glasses with compositions (70-x) P2O530ZnOxCuO (where x= 10, 15 and 20 in mol%) have be... more Phosphate glasses with compositions (70-x) P2O530ZnOxCuO (where x= 10, 15 and 20 in mol%) have been prepared by melt-quenching Procedure. Effect of CuO percentage on the density of prepared samples has been studied. It was found that density decreases from 2.923 to 2.653 gmcm -3 when CuO increases from 10 to 20 mol%. The values of molar volume (Vm), oxygen packing density (O. P. d), oxygen molar volume (VO), optical energy gap (Eopt) and glass transition temperature (Tg) of prepared glasses ware estimated. Moreover the UV-Vis-NIR spectroscopic study has been done and the optical properties of the prepared glasses were estimated. The optical band gap energy (Eopt) has been calculated, it was observed that Eopt increases from 3.33 eV to 3.43 eV with increasing CuO content from 10 to 20 mol%. Herein the glass system 60 P2O530ZnO10CuO has two cut off wavelengths firstly at 420 nm and secondly at 1665 nm while the glasses modified by 15 and 20 mol% of CuO have only one cutoff wavelength...
This study aims to determine the activity concentrations of naturally occurring, technically-enha... more This study aims to determine the activity concentrations of naturally occurring, technically-enhanced levels of radiation and the gamma absorbed dose rates in soil samples collected across the land scape of historical area which discovered in east of Saudi Arabia at 2009 G, Called AL- RAKKAH. By using an HPGe detector gamma-ray spectrometer, the activity concentrations of 226Ra 232Th and 40K were found in surface soil samples ranged from 17. 4 ± 1.2 Bq/kg to 28.3 ± 2.3 Bq/kg with an average value of 23 ± 1.6 Bq/kg, ranging from 1.1 ± 1.8 Bq/kg to 81.0 ± 1.7 Bq/kg with the average value 20 ± 1.4 Bq/kg and from 218 ± 11 Bq/kg to 255 ± 18 Bq/kg, with the mean value of 233 ± 12 Bq/kg respectively. The mean radium equivalent (Raeq) and outdoor radiation hazard index (Hex) for the area under study were determined as 69.52 Bq/kg and 0.16 respectively. The total absorbed dose rate due to three primordial radionuclides lies in the range of 17.74 - 72.24 nGy·h-1 with a mean of 32.69 nGy·h-1, ...
Advances in Physics Theories and Applications, 2015
The aim of the study is to develop tissue equivalent CVD diamond based dosimeters with a carbon b... more The aim of the study is to develop tissue equivalent CVD diamond based dosimeters with a carbon based electrodes. We have initially studied the dependence of induced X-ray photocurrent amplitude and time response as a function of electrode area under broad beam X-ray irradiation. For this purpose, we have fabricated circular electrode sandwich tested structures based on thermal grade polycrystalline CVD diamond with different 3 diameters. The X-ray photocurrent increases with increasing dose rate sub linearly. Although the photocurrent increases with increasing electrode diameter, the increase in current is less than expected from the increase in active area. To further investigate, a small detector based upon 4 separate circular pad was tested for sensitivity with respect to detector area, applied bias voltage and incident x-ray doserate. Additionally the rise time of these detectors was evaluated with respect to the same criteria from these tests there was a non-linear relationshi...
Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 2021
Copper-67 (T1/2 = 61.83 h, Eβ-mean=141 keV, Iβ-total=100%; Eγ = 184.577 keV, Iγ = 48.7%) is a pro... more Copper-67 (T1/2 = 61.83 h, Eβ-mean=141 keV, Iβ-total=100%; Eγ = 184.577 keV, Iγ = 48.7%) is a promising radionuclide for theranostic applications especially in radio immunotherapy. However, one of the main drawbacks for its application is related to its limited availability. Various nuclear reaction routes investigated in the last years can result in 67Cu production, although the use of proton beams is the method of choice taken into account in this work. The goal of this work is a revision of the cross-sections aimed at 67Cu yield, which were evaluated for the 68Zn(p,2p)67Cu reaction route up to 80 MeV proton energy. A well-defined statistical procedure, i.e., the Simultaneous Evaluation on KALMAN (SOK), combined with the least-squares concept, was used to obtain the evaluated data together with the covariance matrix. The obtained evaluated data were also compared to predictions provided by the nuclear reaction model codes TALYS and EMPIRE, and a partial agreement among them has be...
The main goal of the research was to mesure the Radon (222Rn) concentration at indoor workplaces ... more The main goal of the research was to mesure the Radon (222Rn) concentration at indoor workplaces in different Colleges of Princess Nourah Bint Abdualrahman University (PNU), North of Riyadh, KSA, to estimate the effective dose to the worker from 222Rn and its progeny. Measuerments were carried out for 105 workplaces by using a passive integrating ionization system with an E-perm® Electret ion champer technique. Radon concentrations measured in ground, first and second floors of workplaces. Also, the measurements have done in Winter and Summer seasons. For all measurements, Radon concentrations followed a log-normal distribution with an arithmetic mean of 27.86 ± 4.39 Bq/m3 . The effective dose rates from inhalation of radon and its decay products were estimated with a mean of 0.19 mSv/y. There was some variation found between Summer and Winter measuerments, however, radon concentrations measured in Ground floors were significantly higher than those measured in the first and second f...
Abstract We establish baseline measurements for radioactivity concentration in the soil samples c... more Abstract We establish baseline measurements for radioactivity concentration in the soil samples collected from the Qatarian peninsula. The work focused on the naturally occurring and technically enhanced levels of radiation associated with 235,8 U and 232 Th natural decay chains and the long-lived naturally occurring radionuclide 40 K in 129 soil samples collected across the landscape of the State of Qatar. Three radiological distribution maps showing the activity concentrations of 226 Ra, 232 Th and 40 K were constructed. Two soil samples were found to be elevated to the favour of 226 Ra concentration and significantly above the average and global values. Notably, these samples were collected from an area within an oil field (NW Dukhan). The mean values of activity concentrations of 226 Ra, 232 Th and 40 K for the full cohort of samples were found to be 17.2±1.6, 6.38±0.26 and 169±5 Bq/kg, respectively. These values lie within the expected range relative to the world average values in soil samples of 30, 35 and 400 Bq/kg, respectively.
Abstract With interest in establishing baseline concentrations of 137 Cs in soil from the Qataria... more Abstract With interest in establishing baseline concentrations of 137 Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.
Cars of a variety of brands are usually parked at a fixed but increasing distance in the peripher... more Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of ...
Cars of a variety of brands are usually parked at a fixed but increasing distance in the peripher... more Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of ...
While the consumption of seaweed and seaweed-based products is very common amongst East Asian nat... more While the consumption of seaweed and seaweed-based products is very common amongst East Asian nations, forming a notable component of the daily diet, relatively very few studies have concerned the concentrations of heavy metals in these together with potential effects on human health. The present study analyses the concentrations of 17 elements in locally resourced seaweed, also assessing potential noncarcinogenic and carcinogenic risks. The samples were ground, homogenized, and quantified using the ICP-OES technique. It has been found that the essential elements K, Ca, Mg, Zn, and Na typically show concentrations somewhat greater than a number of potentially toxic metals, in particular, Cd, Pb, Ag, and As, with exceptions being Ni, Cr-VI, and Si. Statistical analysis indicates all of the latter to have similar origin, with increased concentration of these metals within the marine ecosystem. While the daily estimated intake of most metals is seen to be within the daily dietary allow...
Background Among the different cancers found in women, breast cancer is the most common. Breast c... more Background Among the different cancers found in women, breast cancer is the most common. Breast cancer-related lymphedema is a serious health complication affecting the quality of life and sleep quality. This study evaluates the quality of life and sleep quality among Saudi women with different stages of lymphedema following the treatment of breast cancer. Methods This cross-sectional correlational study included 163 Saudi women with breast cancer-related lymphedema (Stages I-III), aged 28 to 56 years. From the patients identified for this study, women who suffered from mental and psychological dysfunctions or other malignant disorders were excluded. Copies of structured questionnaires were given to each participant during their visits to outpatient physiotherapy clinics. Quality of life was assessed using a valid questionnaire (EORTC QLQ-C30), while sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The differences between the different lymphedema stages ha...
Metamaterial analysis for microwave frequencies is a common practice. However, adopting a multi-l... more Metamaterial analysis for microwave frequencies is a common practice. However, adopting a multi-layered design is unique in the concept of miniaturisation, thus requiring extensive research for optimal performance. This study focuses on a multi-layered symmetric metamaterial design for C- and X-band applications. All simulation analyses were performed analytically using Computer Simulation Technology Studio Suite 2019. The performances of the proposed metamaterial design were analysed through several parametric studies. Based on the observation, the proposed metamaterial unit cell design manifested resonant frequencies at 7.63 GHz (C-band) and 9.56 GHz (X-band). Moreover, the analysis of effective medium parameters was also included in this study. High-Frequency Simulation 15.0 and Advanced Design System 2020 software validated the transmission coefficient results. Simultaneously, the proposed multi-layered metamaterial design with Rogers RO3006 substrate material exhibited a unique...
A commercially viable metal–dielectric–metal configured triple-band metamaterial absorber is offe... more A commercially viable metal–dielectric–metal configured triple-band metamaterial absorber is offered in this paper. It is an aggregation of four compact symmetric circles, with a swastika-shaped metal structure, which are bonded by two split-ring resonators (SRRs). Copper (annealed) of electrical conductivity 5.8 × 107 Sm−1 is used for the ground plate and resonator portion of the top layer and an FR 4 dielectric of permittivity 4.3 is used as a substrate. The structural parameters of the unit cell were determined by a trial and error method. FIT-based 3D simulation software (CST microwave studio, 2019 version was used to characterize the proposed perfect metamaterial absorber (PMA). Three resonance peaks were observed at frequencies 3.03, 5.83 and 7.23 GHz with an absorbance of 99.84%, 99.03% and 98.26%, respectively. The numerical result has been validated by some authentic validation methods. Finally, a microwave network analyzer (PNA) of Agilent N5227 with waveguide ports were d...
A split-ring resonator (SRR)-based power tiller wheel-shaped quad-band ℇ-negative metamaterial is... more A split-ring resonator (SRR)-based power tiller wheel-shaped quad-band ℇ-negative metamaterial is presented in this research article. This is a new compact metamaterial with a high effective medium ratio (EMR) designed with three modified octagonal split-ring resonators (OSRRs). The electrical dimension of the proposed metamaterial (MM) unit cell is 0.086λ × 0.086λ, where λ is the wavelength calculated at the lowest resonance frequency of 2.35 GHz. Dielectric RT6002 materials of standard thickness (1.524 mm) were used as a substrate. Computer simulation technology (CST) Microwave Studio simulator shows four resonance peaks at 2.35, 7.72, 9.23 and 10.68 GHz with magnitudes of −43.23 dB −31.05 dB, −44.58 dB and −31.71 dB, respectively. Moreover, negative permittivity (ℇ) is observed in the frequency ranges of 2.35–3.01 GHz, 7.72–8.03 GHz, 9.23–10.02 GHz and 10.69–11.81 GHz. Additionally, a negative refractive index is observed in the frequency ranges of 2.36–3.19 GHz, 7.74–7.87 GHz, 9...
In this article, we present the use of a metamaterial-incorporated microwave-based sensor with a ... more In this article, we present the use of a metamaterial-incorporated microwave-based sensor with a single port network for material characterization. The proposed sensor consists of a microstrip patch layer enclosed with a dual-square-shaped metamaterial split-ring. This structure has the dimensions of 20 × 20 × 1.524 mm3 and a copper metallic layer is placed on a Rogers RT 6002 with a partial back layer as a ground. Two resonant frequencies are exhibited for applied electromagnetic interaction using a transmission line. The dual split rings increase the compactness and accumulation of the electromagnetic field on the surface of the conducting layer to improve the sensitivity of the sensor. The numerical studies are carried out using a CST high-frequency microwave simulator. The validation of the proposed sensor is performed with an equivalent circuit model in ADS and numerical high-frequency simulator HFSS. The material under test placed on the proposed sensor shows good agreement wi...
Despite their widespread use for performing advanced electromagnetic properties, metamaterial suf... more Despite their widespread use for performing advanced electromagnetic properties, metamaterial suffers from several restrictions in this technological era. Generally, technology affects the way individuals communicate, learn, think and plays an important role in society today. For this reason, there has been a surge of interest in a coding metamaterial field that possesses the ability to manipulate electromagnetic waves and realize different functionalities. This research work investigates circular-shaped coding metamaterial for microwave frequency applications through several analyses. First, the 1-bit coding metamaterial that is made up of only "0" and "1" elements with 0 and π phase responses by adopting two types of unit cells such as square-shaped Rogers RT6002 substrate material with and without metamaterial structure were analysed in this work. The proposed element '1' successfully manifests several more than 180○ phase responses at several frequency ranges, for instance, 7.35 to 9.48 GHz, 12.87 to 14.25 GHz and 17.49 to 18 GHz (C, X, and Ku-bands), respectively. Besides that, three types of coding sequences were proposed and the radar cross-section (RCS) reduction values of the designs were numerically calculated by utilising Computer Simulation Technology (CST) software. Meanwhile, the single-layered coding metamaterial with 6 lattices was compared with double and triple-layered metamaterial structures. At 2 GHz, the triple-layered structure exhibit reduced RCS values with near to − 30 dBm 2 for all coding sequences. Therefore, the transmission coefficient results of the triple-layered coding metamaterial sequences were numerically calculated. Several advanced coding metamaterial designs were constructed and the properties were discussed in terms of RCS values and scattering patterns. Meanwhile, the scattering and effective medium parameters of the unit cell metamaterial structure were also analysed in this work. In a nutshell, the 1-bit coding metamaterial in a controlled sequence can control electromagnetic waves and realize different functionalities. Research investigations regarding metamaterial have become familiar among the scientific community in the past few decades. Potential applications of metamaterial are diverse and include electromagnetic absorption reduction, sensor, terahertz frequency application, metamaterial filter, metamaterial absorption, etc. are successfully adapted metamaterial design structures to gain unique results 1-5. Generally, the metamaterial design structure has its unique way of light interacting when compared to conventional materials. Conventional material can be easier found in nature but lacks in producing extraordinary electromagnetic properties. For instance, left-handed behaviour is very possible in man-made design structures instead of conventional materials. However, the current advanced technology is required beyond normal metamaterial structure design to optimise the performance to utilise in many application fields. Moreover, for specific applications likely metamaterial antenna, the conventional material is difficult to manufacture in large quantities. Meanwhile, the metamaterial absorption commonly has a very low narrow absorption band and shows a dispersion phenomenon outstandingly in the far-infrared domain. Therefore, many new concepts and ideas are developed in recent years such as metasurface, mechanical metamaterial, photonic metamaterial, acoustic metamaterial, plasmonic metamaterial, etc.
In this research work, the development of the metamaterial unit cell is used to investigate multi... more In this research work, the development of the metamaterial unit cell is used to investigate multifunctional characteristics, exhibit preferable and capable adjustability, reconfigurable by changing the phase response of applied electromagnetic wave. This proposed metamaterial unit cell is analysed by modifying the geometric design of the metallic structure which mitigates the design to reduce the cost for the commercialisation. The resonant frequencies are located from 1.87, 2.55, 4.32, 5.46 GHz. The interaction with the electric field and magnetic field exhibit the polarisation in both planes which enhances the left handed characteristics. The field distribution of electric, magnetic, and surface current is presented with vector fields in different planes to observe the polarisation state. Different thicknesses of dielectric material are utilised to observe the impact of time varying electric and magnetic fields through the proposed metamaterial. The different substrate materials a...
Introduccion: El desarrollo pulmonar, proceso complejo y altamente organizado, constituye una a... more Introduccion: El desarrollo pulmonar, proceso complejo y altamente organizado, constituye una atractiva y dinamica area de investigacion constante. Metodologia: estudio descriptivo, transversal y correlacional realizado en nueve embriones humanos de semana ocho, pertenecientes a la Embrioteca de la facultad de Medicina de Villa Clara. Los especimenes se procesaron histologicamente por tecnica de parafina, procedentes de interrupcion del embarazo por Misoprostol, digitalizados sus cortes y medidos las secciones seriadas de los pulmones mediante las opciones de area y distancia del software Escopephoto 3.0; para el calculo del volumen se empleo el espesor del corte multiplicado por la sumatoria de areas parciales. Se utilizo la prueba de Mann-Whitney para la comparacion de volumenes. Resultados: la semana estudiada encontramos que los pulmones tuvieron predominio longitudinal y en el mismo eje hicieron sus mayores incrementos, el pulmon izquierdo incremento menos su eje lateral con...
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Phosphate glasses with compositions (70-x) P2O530ZnOxCuO (where x= 10, 15 and 20 in mol%) have be... more Phosphate glasses with compositions (70-x) P2O530ZnOxCuO (where x= 10, 15 and 20 in mol%) have been prepared by melt-quenching Procedure. Effect of CuO percentage on the density of prepared samples has been studied. It was found that density decreases from 2.923 to 2.653 gmcm -3 when CuO increases from 10 to 20 mol%. The values of molar volume (Vm), oxygen packing density (O. P. d), oxygen molar volume (VO), optical energy gap (Eopt) and glass transition temperature (Tg) of prepared glasses ware estimated. Moreover the UV-Vis-NIR spectroscopic study has been done and the optical properties of the prepared glasses were estimated. The optical band gap energy (Eopt) has been calculated, it was observed that Eopt increases from 3.33 eV to 3.43 eV with increasing CuO content from 10 to 20 mol%. Herein the glass system 60 P2O530ZnO10CuO has two cut off wavelengths firstly at 420 nm and secondly at 1665 nm while the glasses modified by 15 and 20 mol% of CuO have only one cutoff wavelength...
This study aims to determine the activity concentrations of naturally occurring, technically-enha... more This study aims to determine the activity concentrations of naturally occurring, technically-enhanced levels of radiation and the gamma absorbed dose rates in soil samples collected across the land scape of historical area which discovered in east of Saudi Arabia at 2009 G, Called AL- RAKKAH. By using an HPGe detector gamma-ray spectrometer, the activity concentrations of 226Ra 232Th and 40K were found in surface soil samples ranged from 17. 4 ± 1.2 Bq/kg to 28.3 ± 2.3 Bq/kg with an average value of 23 ± 1.6 Bq/kg, ranging from 1.1 ± 1.8 Bq/kg to 81.0 ± 1.7 Bq/kg with the average value 20 ± 1.4 Bq/kg and from 218 ± 11 Bq/kg to 255 ± 18 Bq/kg, with the mean value of 233 ± 12 Bq/kg respectively. The mean radium equivalent (Raeq) and outdoor radiation hazard index (Hex) for the area under study were determined as 69.52 Bq/kg and 0.16 respectively. The total absorbed dose rate due to three primordial radionuclides lies in the range of 17.74 - 72.24 nGy·h-1 with a mean of 32.69 nGy·h-1, ...
Advances in Physics Theories and Applications, 2015
The aim of the study is to develop tissue equivalent CVD diamond based dosimeters with a carbon b... more The aim of the study is to develop tissue equivalent CVD diamond based dosimeters with a carbon based electrodes. We have initially studied the dependence of induced X-ray photocurrent amplitude and time response as a function of electrode area under broad beam X-ray irradiation. For this purpose, we have fabricated circular electrode sandwich tested structures based on thermal grade polycrystalline CVD diamond with different 3 diameters. The X-ray photocurrent increases with increasing dose rate sub linearly. Although the photocurrent increases with increasing electrode diameter, the increase in current is less than expected from the increase in active area. To further investigate, a small detector based upon 4 separate circular pad was tested for sensitivity with respect to detector area, applied bias voltage and incident x-ray doserate. Additionally the rise time of these detectors was evaluated with respect to the same criteria from these tests there was a non-linear relationshi...
Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine, 2021
Copper-67 (T1/2 = 61.83 h, Eβ-mean=141 keV, Iβ-total=100%; Eγ = 184.577 keV, Iγ = 48.7%) is a pro... more Copper-67 (T1/2 = 61.83 h, Eβ-mean=141 keV, Iβ-total=100%; Eγ = 184.577 keV, Iγ = 48.7%) is a promising radionuclide for theranostic applications especially in radio immunotherapy. However, one of the main drawbacks for its application is related to its limited availability. Various nuclear reaction routes investigated in the last years can result in 67Cu production, although the use of proton beams is the method of choice taken into account in this work. The goal of this work is a revision of the cross-sections aimed at 67Cu yield, which were evaluated for the 68Zn(p,2p)67Cu reaction route up to 80 MeV proton energy. A well-defined statistical procedure, i.e., the Simultaneous Evaluation on KALMAN (SOK), combined with the least-squares concept, was used to obtain the evaluated data together with the covariance matrix. The obtained evaluated data were also compared to predictions provided by the nuclear reaction model codes TALYS and EMPIRE, and a partial agreement among them has be...
The main goal of the research was to mesure the Radon (222Rn) concentration at indoor workplaces ... more The main goal of the research was to mesure the Radon (222Rn) concentration at indoor workplaces in different Colleges of Princess Nourah Bint Abdualrahman University (PNU), North of Riyadh, KSA, to estimate the effective dose to the worker from 222Rn and its progeny. Measuerments were carried out for 105 workplaces by using a passive integrating ionization system with an E-perm® Electret ion champer technique. Radon concentrations measured in ground, first and second floors of workplaces. Also, the measurements have done in Winter and Summer seasons. For all measurements, Radon concentrations followed a log-normal distribution with an arithmetic mean of 27.86 ± 4.39 Bq/m3 . The effective dose rates from inhalation of radon and its decay products were estimated with a mean of 0.19 mSv/y. There was some variation found between Summer and Winter measuerments, however, radon concentrations measured in Ground floors were significantly higher than those measured in the first and second f...
Abstract We establish baseline measurements for radioactivity concentration in the soil samples c... more Abstract We establish baseline measurements for radioactivity concentration in the soil samples collected from the Qatarian peninsula. The work focused on the naturally occurring and technically enhanced levels of radiation associated with 235,8 U and 232 Th natural decay chains and the long-lived naturally occurring radionuclide 40 K in 129 soil samples collected across the landscape of the State of Qatar. Three radiological distribution maps showing the activity concentrations of 226 Ra, 232 Th and 40 K were constructed. Two soil samples were found to be elevated to the favour of 226 Ra concentration and significantly above the average and global values. Notably, these samples were collected from an area within an oil field (NW Dukhan). The mean values of activity concentrations of 226 Ra, 232 Th and 40 K for the full cohort of samples were found to be 17.2±1.6, 6.38±0.26 and 169±5 Bq/kg, respectively. These values lie within the expected range relative to the world average values in soil samples of 30, 35 and 400 Bq/kg, respectively.
Abstract With interest in establishing baseline concentrations of 137 Cs in soil from the Qataria... more Abstract With interest in establishing baseline concentrations of 137 Cs in soil from the Qatarian peninsula, we focus on determination of the activity concentrations in 129 soil samples collected across the State of Qatar prior to the 2011 Fukushima Dai-ichi nuclear power plant accident. As such, the data provides the basis of a reference map for the detection of releases of this fission product. The activity concentrations were measured via high-resolution gamma-ray spectrometry using a hyper-pure germanium detector enclosed in a copper-lined passive lead shield that was situated in a low-background environment. The activity concentrations ranged from 0.21 to 15.41 Bq/kg, with a median value of 1 Bq/kg, the greatest activity concentration being observed in a sample obtained from northern Qatar. Although it cannot be confirmed, it is expected that this contamination is mainly due to releases from the Chernobyl accident of 26 April 1986, there being a lack of data from Qatar before the accident. The values are typically within but are sometimes lower than the range indicated by data from other countries in the region. The lower values than those of others is suggested to be due to variation in soil characteristics as well as metrological factors at the time of deposition.
Cars of a variety of brands are usually parked at a fixed but increasing distance in the peripher... more Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of ...
Cars of a variety of brands are usually parked at a fixed but increasing distance in the peripher... more Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of ...
While the consumption of seaweed and seaweed-based products is very common amongst East Asian nat... more While the consumption of seaweed and seaweed-based products is very common amongst East Asian nations, forming a notable component of the daily diet, relatively very few studies have concerned the concentrations of heavy metals in these together with potential effects on human health. The present study analyses the concentrations of 17 elements in locally resourced seaweed, also assessing potential noncarcinogenic and carcinogenic risks. The samples were ground, homogenized, and quantified using the ICP-OES technique. It has been found that the essential elements K, Ca, Mg, Zn, and Na typically show concentrations somewhat greater than a number of potentially toxic metals, in particular, Cd, Pb, Ag, and As, with exceptions being Ni, Cr-VI, and Si. Statistical analysis indicates all of the latter to have similar origin, with increased concentration of these metals within the marine ecosystem. While the daily estimated intake of most metals is seen to be within the daily dietary allow...
Background Among the different cancers found in women, breast cancer is the most common. Breast c... more Background Among the different cancers found in women, breast cancer is the most common. Breast cancer-related lymphedema is a serious health complication affecting the quality of life and sleep quality. This study evaluates the quality of life and sleep quality among Saudi women with different stages of lymphedema following the treatment of breast cancer. Methods This cross-sectional correlational study included 163 Saudi women with breast cancer-related lymphedema (Stages I-III), aged 28 to 56 years. From the patients identified for this study, women who suffered from mental and psychological dysfunctions or other malignant disorders were excluded. Copies of structured questionnaires were given to each participant during their visits to outpatient physiotherapy clinics. Quality of life was assessed using a valid questionnaire (EORTC QLQ-C30), while sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). The differences between the different lymphedema stages ha...
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Papers by K.s. Al-mugren