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Influence of thyroid volume reduction on absorbed dose in ^(131)I therapy studied by using Geant4 monte Carlo simulation

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Chinese Physics C 2014年第5期38卷 62-68页

作者： Ziaur Rahman Sikander m mirza Waheed Arshed nasir m mirza Waheed Ahmed Health Physics Division Pakistan Institute of Nuclear Science and Technology Department of Physics and Applied mathematics Pakistan Institute of Engineering and Applied Sciences

A simulation study has been performed to quantify the effect of volume reduction on the thyroid absorbed dose per decay and to investigate the variation of energy deposition per decay due to β- and γ-activity of 131I with volume/mass of thyroid, for water, ICRP- and ICRU-soft tissue taken as thyroid material. A monte Carlo model of the thyroid, in the Geant4 radiation transport simulation toolkit was constructed to compute the β- and γ-absorbed dose in the simulated thyroid phantom for various values of its volume. The effect of the size and shape of the thyroid on energy deposition per decay has also been studied by using spherical, ellipsoidal and cylindrical models for the thyroid and varying its volume in 1-25 cm3 range. The relative differences of Geant4 results for different models with each other and mCNP results lie well below 1.870%. The maximum relative difference among the Geant4 estimated results for water with ICRP and ICRU soft tissues is not more than 0.225%. S-values for ellipsoidal, spherical and cylindrical thyroid models were estimated and the relative difference with published results lies within 3.095%. The absorbed fraction values for beta particles show a good agreement with published values within 2.105% deviation. The Geant4 based simulation results of absorbed fractions for gammas again show a good agreement with the corresponding mCNP and EGS4 results （±6.667%） but have 29.032% higher values than that of mIRD calculated values. Consistent with previous studies, the reduction of the thyroid volume is found to have a substantial effect on the absorbed dose. Geant4 simulations confirm dose dependence on the volume/mass of thyroid in agreement with mCNP and EGS4 computed values but are substantially different from mIRD8 data. Therefore, inclusion of size/mass dependence is indicated for 131I radiotherapy of the thyroid.

关键词： mean absorbed dose rate Geant4 monte Carlo simulation and 131I therapy

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Absorbed dose estimations of ^(131)I for critical organs using the GEANT4 monte Carlo simulation code

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Chinese Physics C 2012年第11期36卷 1150-1156页

作者： Ziaur Rahman Shakeel ur Rehman Waheed Arshed nasir m mirza Abdul Rashid Jahan Zeb Health Physics Division Pakistan Institute of Nuclear Science & TechnologyNiloreIslamabad 45650Pakistan Department of Physics & Applied mathematics Pakistan Institute of Engineering & Applied SciencesNiloreIslamabad 45650Pakistan

The aim of this study is to compare the absorbed doses of critical organs of 131I using the mIRD （medical Internal Radiation Dose） with the corresponding predictions made by GEANT4 simulations. S- values （mean absorbed dose rate per unit activity） and energy deposition per decay for critical organs of 131I for various ages, using standard cylindrical phantom comprising water and ICRP soft-tissue material, have also been estimated. In this study the effect of volume reduction of thyroid, during radiation therapy, on the calculation of absorbed dose is also being estimated using GEANT4. Photon specific energy deposition in the other organs of the neck, due to 131I decay in the thyroid organ, has also been estimated. The maximum relative difference of mIRD with the GEANT4 simulated results is 5.64% for an adult＇s critical organs of 131I. Excellent agreement was found between the results of water and ICRP soft tissue using the cylindrical model. S-values are tabulated for critical organs of 131I, using 1, 5, 10, 15 and 18 years （adults） individuals. S-values for a cylindrical thyroid of different sizes, having 3.07% relative differences of GEANT4 with Siegel ＆ Stabin results. Comparison of the experimentally measured values at 0.5 and 1 m away from neck of the ionization chamber with GEANT4 based monte Carlo simulations results show good agreement. This study shows that GEANT4 code is an important tool for the internal dosimetry calculations.

关键词： mean absorbed dose rate GEANT4 monte Carlo simulation and 131I critical organs

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Evaluation of Corrosion Product Activity in a Typical PWR with Extended Cycles and Flow Rate Perturbations

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World Journal of Nuclear Science and Technology 2017年第1期7卷 24-34页

作者： Rubina nasir Sikander m. mirza nasir m. mirza Department of Physics Air University Islamabad Pakistan Department of Physics & Applied mathematics Pakistan Institute of Engineering & Applied Sciences Islamabad Pakistan

Effect of flow rate perturbations has been studied using the modified computer program CPAIR-P for time dependent corrosion rates in Pressurized Water Reactors (PWRs) having extended cycles. In these simulations, a decrease in the corresponding saturation values of corrosion product activity (CPA) is observed for higher pH values. Comparison of CPA’s behavior has been done for constant flow-rate case as well as for transients with elevated 10B levels (~40%) in dissolved boric acid in coolant in two operating cycles. When the flow rate is decreased in the first cycle, the saturation value of CPA attains new higher values. Also, in the second operating cycle, the saturation values are about 12% higher when compared with the values in the first cycle.

关键词： PWRs Corrosion Products Enriched Boric Acid Extended Cycles Flow Rate Perturbations

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Tuning structural,electrical,dielectric and magnetic properties of mg-Cu-Co ferrites via dysprosium(Dy^(3+))doping

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Journal of Rare Earths 2024年第1期42卷 137-146,I0005页

作者： maria Akhtar m.S.Hasan nasir Amin N.A.morley muhammad Imran Arshad Department of Physics Government College UniversityFaisalabad38000Pakistan Department of Physics The University of Lahore53700Pakistan Department of materials Science and Engineering The University of SheffieldS13JDUK Department of Physics&Astronomy University College LondonUK

In current research work,Dy3+substituted mg0.5Cu0.25Co0.25Fe2-xDyxO4(0.0≤x≤0.04 with the step interval of 0.01)soft ferrites were synthesized by the sol-gel auto combustion *** prepared samples were characterized by the techniques using X-ray diffraction(XRD),scanning electron microscopy(SEm),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared(FTIR)spectroscopy,curre nt-voltage(Ⅰ-Ⅴ)measurement,LCR meter,vibrating sample magnetometer(VSm)and *** data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x=*** non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX *** DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in ***,the high resistivity is observed with the order of 1010Ω·cm,and the activation energy is 0.944 eV for samples x=*** dielectric parameters including dielectric constant,dielectric losses,and impedance gradually decrease with the increase in frequency from 8 Hz to 8 *** minimum dielectric loss at high frequency is found for sample x=*** coercivity(Hc)and saturation magnetization(ms)are found in the ranges of 520.82-544.02 Oe and 20.5841-21.1473 emu/g,*** observations confirm that dysprosium(x=0.03)doped mCC-soft ferrites may be applicable in transformer cores,microwave absorbance,and telecommunication devices.

关键词： Soft ferrites DC resistivity Dielectric loss Impedance Coercivity Rare earths

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mixed convectional and chemical reactive flow of nanofluid with slanted mHD on moving permeable stretching/shrinking sheet through nonlinear radiation,energy omission

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Chinese Physics B 2024年第5期33卷 193-202页

作者： Saleem nasir Sekson Sirisubtawee Pongpol Juntharee Taza Gul Department of mathematics Faculty of Applied ScienceKing Mongkut's University of Technology North BangkokBangkok 10800Thailand Department of mathematics City University of Science and Information TechnologyPeshawarPakistan

Hybrid nanofluids are remarkable functioning liquids that are intended to reduce the energy loss while maximizing the heat *** the involvement of suction and nonlinear thermal radiation effects,this study attempted to explore the energy transmission features of the inclined magnetohydrodynamic(mHD)stagnation flow of CNTs-hybrid nanofluid across the nonlinear permeable stretching or shrinking *** work also included some noteworthy features like chemical reactions,variable molecular diffusivity,quadratic convection,viscous dissipation,velocity slip and heat omission *** appropriate similarity components,the model equations were modified to ODEs and computed by using the HAm *** impact of various relevant flow characteristics on movement,heat and concentration profiles was investigated and plotted on a *** various model factors,the significance of drag friction,heat and mass transfer rate were also computed in tabular and graphical *** leads to the conclusion that such factors have a considerable impact on the dynamics of fluid as well as other engineering measurements of ***,viscous forces are dominated by increasing the values ofλ_(p),δ_(m)andδ_(q),and as a result,F(ξ)accelerates while the opposite trend is observed for m andφ.The drag friction is boosted by the augmentation m,λ_(p)andφ,but the rate of heat transfer *** to our findings,hybrid nanoliquid effects dominate that of ordinary nanofluid in terms of F(ξ),Θ(ξ)andφ(ξ)*** HAm and the numerical technique(shooting method)were found to be in good agreement.

关键词： hybrid nanofluid(SWCNT+mWCNT/H_(2)O) velocity slip conditions nonlinear thermal radiation exponential stretching/shrinking sheet inclined magnetohydrodynamic(mHD)stagnation flow

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Cervical Cancer Prediction Empowered with Federated machine Learning

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Computers, materials & Continua 2024年第4期79卷 963-981页

作者： muhammad Umar nasir Omar Kassem Khalil Karamath Ateeq Bassam SaleemAllah Almogadwy m.A.Khan Khan muhammad Adnan Department of Computer Sciences Bahria University Lahore CampusLahore54000Pakistan Faculty of Information Technology Liwa CollegeAbu Dhabi20009UAE Department of Computing Skyline University CollegeSharjah999041UAE Department of Computer Science Taibah UniversityMedina42315Saudi Arabia Riphah School of Computing and Innovation Faculty of ComputingRiphah International UniversityLahore54000Pakistan Department of Software Faculty of Artificial Intelligence and SoftwareGachon UniversitySeongnam13120Korea

Cervical cancer is an intrusive cancer that imitates various women around the world. Cervical cancer ranks in thefourth position because of the leading death cause in its premature stages. The cervix which is the lower end of thevagina that connects the uterus and vagina forms a cancerous tumor very slowly. This pre-mature cancerous tumorin the cervix is deadly if it cannot be detected in the early stages. So, in this delineated study, the proposed approachuses federated machine learning with numerous machine learning solvers for the prediction of cervical cancer totrain the weights with varying neurons empowered fuzzed techniques to align the neurons, Internet of medicalThings (IomT) to fetch data and blockchain technology for data privacy and models protection from hazardousattacks. The proposed approach achieves the highest cervical cancer prediction accuracy of 99.26% and a 0.74%misprediction rate. So, the proposed approach shows the best prediction results of cervical cancer in its early stageswith the help of patient clinical records, and all medical professionals will get beneficial diagnosing approachesfrom this study and detect cervical cancer in its early stages which reduce the overall death ratio of women due tocervical cancer.

关键词： Cervical cancer federated machine learning neurons blockchain technology

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Corrosion and Scaling Threat in Upstream Oil Operation

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World Journal of Engineering and Technology 2024年第2期12卷 426-437页

作者： nasir Ullattumpoyil Talal m. Al-Ghamdi Nasser R. Al-Hajri Southern Area Technical Support Department Saudi Aramco Dhahran KSA

Corrosiveness or scaling is an inherent threat to oil operations. The primary cause for this threat is the presence of water having complex geochemical matrix. Unanticipated water production, particularly if it contains unwanted impurities, can significantly impact hydrocarbon production. The current paper discusses the degree of threat posed to oil operation facilities based on the water characteristics. methodology involved the collection and analysis of water samples from major sources in oil industry such as groundwater, wellheads and seawater. The parameters tested include geochemical, microbiological and pollutants. The lab data was used to develop scaling and corrosion prediction indices such as Langelier Saturation Index (LSI), Ryznar Stability Index (RSI) and Puckorius Scaling Index (PSI). The study indicated varying water chemistry for different sources. mixing of those waters may lead to ionic saturation and scaling in different facilities. Presence of the SRB and GAB in some water sources also posed threat to water system by forming fouling and corrosion. Seawater used for offshore oilfields water injection to maintain reservoir pressure and improve oil recovery showed scaling tendency, whereas under different reservoir pressure, it can cause corrosion. Some of the samples also had corrosion residuals such as iron, which indicated active corrosion. Current study showed higher alkalinity with high sulfate for one groundwater sample with presence of active corrosion residuals such as dissolved iron and manganese. The study showed positive value for LSI which indicated supersaturation of the water samples with respect to calcium carbonate (CaCO3) and scale forming. Similarly, for RSI and PSI, the value was below six which confirmed the scaling potential for all the samples. Even though the index value was pointing towards scaling potential, the geochemistry, microbiology and presence of other impurities indicated corrosion threat to the oil and g

关键词： Formation Water Petroleum Reservoirs Groundwater Saturation Indices Corrosiveness

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A hyperspectral unmixing approach for ink mismatch detection in unbalanced clusters

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Journal of Information and Intelligence 2024年第2期2卷 177-190页

作者： Faryal Aurooj nasir Salman Liaquat Khurram Khurshid Nor muzlifah mahyuddin Department of Electrical Engineering Institute of Space TechnologyIslamabad 44000Pakistan School of Electrical and Electronic Engineering Universiti Sains MalaysiaPenang 14300Malaysia

With the rapid development of location-based services and online social networks,POI recommendation services considering geographic and social factors have received extensive ***,the vigorous development of cloud computing has prompted service providers to outsource data to the cloud to provide POI recommendation ***,there is a degree of distrust of the cloud by service *** protect digital assets,service providers encrypt data before outsourcing ***,encryption reduces data availability,making it more challenging to provide POI recommendation services in outsourcing *** privacy-preserving schemes for geo-social-based POI recommendation have been presented,but they have some limitations in supporting group query,considering both geographic and social factors,and query accuracy,making these schemes *** solve this issue,we propose two practical and privacy-preserving geo-social-based POI recommendation schemes for single user and group users,which are named GSPR-S and ***,we first utilize the quad tree to organize geographic data and the minHash method to index social ***,we apply BGV fully homomorphic encryption to design some private algorithms,including a private max/min operation algorithm,a private rectangular set operation algorithm,and a private rectangular overlapping detection *** that,we use these algorithms as building blocks in our schemes for efficiency *** to security analysis,our schemes are proven to be secure against the honest-but-curious cloud servers,and experimental results show that our schemes have good performance.

关键词： k-means clustering Gaussian mixture model(Gmm) Hyper spectral imaging(HSI) iVision handwritten hyperspectral images dataset(HHID) Document forensics

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Short Communication: Enhancing the Drying Process of microbial-Based Products with a Dehumidifier

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Advances in microbiology 2024年第6期14卷 333-339页

作者： Nor Hidayah Bohari Elya masya mohd Fishal Ili Bazilah Abd Razak muhammad Ashraf Arif mohd nasir Cik mohd Rizuan Zainal Abidin Crop Protection and Biosolutions Department FGV R&D Sdn Bhd Bandar Enstek Malaysia

The development of microbial-based products requires certain criteria for them to be successfully commercialized. The product must meet the following desirable criteria: effectiveness, contamination free, stability, cost-effectiveness, and a prolonged shelf life. Controlling the drying process is crucial for ensuring the stability and durability of the product. The traditional approach, which involved mechanical and natural drying, led to decreased productivity and quality. The objective of this research endeavour was to achieve a dry process enhancement while preserving the microbial quality of Trichoderma asperellum (m103). The temperature and relative humidity during the drying period were monitored under two conditions: with and without a dehumidifier. The results demonstrate that the dehumidifier increases drying period efficiency by up to 63%.

关键词： Dehumidifier Drying Relative Humidity microbial-Based Product

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Effects of f(R) model on Dynamics of Axial Shear-Free Dissipative Fluids

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Communications in Theoretical Physics 2016年第4期65卷 483-491页

作者： m.Sharif Zunaira nasir Department of mathematics University of the Punjab

We present a general analysis on non-static axial system with dissipative shear-free anisotropic fluid using polynomial inflationary f(R) *** study the effects of dissipation on the dynamics of geodesic matter *** leads the system either to rotation-free or expansion-free but not both simultaneously under geodesic *** is found that the system preserves its symmetry in both *** the rotation-free case,when there is no dissipation and Ricci scalar is constant,the axial system reduces to FRW universe *** is exactly the same result obtained in general relativity.

关键词： f(R) gravity dissipative systems self-gravitating systems

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