This paper presents the rheological behaviour of supercritical CO2 （sCO2） foam at reser- voir conditions of I 500 psi and 80 ℃. Different commercial surfactants were screened and utilized in or- der to generate a f...This paper presents the rheological behaviour of supercritical CO2 （sCO2） foam at reser- voir conditions of I 500 psi and 80 ℃. Different commercial surfactants were screened and utilized in or- der to generate a fairly stable CO2 foam. Mixed surfactant system was also introduced to generate strong foam. Foam rheology was studied for some specific foam qualities using a high pressure high tempera- ture （HPHT） foam loop rheometer. A typical shear thinning behaviour of the foam was observed and a significant increase in the foam viscosity was noticed with the increase of foam quality until 85%. A de- sired high apparent viscosity with coarse texture was found at 85% foam quality. Foam visualization above 85% showed an unstable foam due to extremely thin lamella which collapsed and totally disap- peared in the loop rheometer. Below 52%, a non-homogenous and unstable foam was found having low viscosity with some liquid accumulation at the bottom of the circulation loop. This research has demon- strated rheology of sCO2 foams at different qualities at HPHT to obtain optimal foam quality region for immiscible CO2 foam co-injection process.展开更多
Landmines continue to pose an ongoing threat in various regions around the world,with countless buried landmines affecting numerous human lives.The detonation of these landmines results in thousands of casualties repo...Landmines continue to pose an ongoing threat in various regions around the world,with countless buried landmines affecting numerous human lives.The detonation of these landmines results in thousands of casualties reported worldwide annually.Therefore,there is a pressing need to employ diverse landmine detection techniques for their removal.One effective approach for landmine detection is UAV(Unmanned Aerial Vehicle)based AirborneMagnetometry,which identifies magnetic anomalies in the local terrestrial magnetic field.It can generate a contour plot or heat map that visually represents the magnetic field strength.Despite the effectiveness of this approach,landmine removal remains a challenging and resource-intensive task,fraughtwith risks.Edge computing,on the other hand,can play a crucial role in critical drone monitoring applications like landmine detection.By processing data locally on a nearby edge server,edge computing can reduce communication latency and bandwidth requirements,allowing real-time analysis of magnetic field data.It enables faster decision-making and more efficient landmine detection,potentially saving lives and minimizing the risks involved in the process.Furthermore,edge computing can provide enhanced security and privacy by keeping sensitive data close to the source,reducing the chances of data exposure during transmission.This paper introduces the MAGnetometry Imaging based Classification System(MAGICS),a fully automated UAV-based system designed for landmine and buried object detection and localization.We have developed an efficient deep learning-based strategy for automatic image classification using magnetometry dataset traces.By simulating the proposal in various network scenarios,we have successfully detected landmine signatures present in themagnetometry images.The trained models exhibit significant performance improvements,achieving a maximum mean average precision value of 97.8%.展开更多
In this review article, various preferences in breast plastic surgery particularly after breast cancer will be discussed in view of the diverse indications for the different construction procedures. The various condit...In this review article, various preferences in breast plastic surgery particularly after breast cancer will be discussed in view of the diverse indications for the different construction procedures. The various conditions that necessitate the need for reconstruction are appraised, the important reconstructive procedures are discussed. The most important indications procedures discussed in this review include;Prophylactic subcutaneous mastectomy, Lumpectomy and Radiation, Modified Mastectomy with Axillary Sampling, Nipple reconstruction, and the contralateral breast. These procedures are discussed in view of plastic surgeon practice and patients acceptability in Saudi Arabia. Data from Saudi Arabia in particular was identified through searches of the EMBASE, and MEDLINE database, using the keywords: Saudi Arabia, breast plastic Surgery, breast reconstruction, autologous breast reconstruction, breast augmentation. Advances in prosthetic technologies and modifications in autologous flap techniques, and the development of novel tissue alternatives have allowed for sustained developments in breast reconstruction results. A variety of attitudes has been accessible for addressing the difficulties that endure after resection of breast cancer in Saudi Arabia. Patients should be educated to accept different process in this context.展开更多
<strong>Introduction:</strong> Paranasal sinuses mucoceles are benign, epithelial lined, mucus filled lesions, causing destruction of the adjacent sinus walls, and with further gradual extension to adjacen...<strong>Introduction:</strong> Paranasal sinuses mucoceles are benign, epithelial lined, mucus filled lesions, causing destruction of the adjacent sinus walls, and with further gradual extension to adjacent structures, serious morbidities and mortalities may occur. <strong>Objective:</strong> To emphasize on the efficacy of endonasal endoscopic marsupialization in the treatment of paranasal sinus mucoceles. <strong>Method:</strong> Retrospective descriptive study on paranasal sinus mucocele cases operated on endoscopically by the author (AAM), in the 10-year-period from to 2009-2019. <strong>Result:</strong> Total of 23 cases were included, 16 were males and 7 females, age ranging between 14 - 76 years, with a mean age of 45 years Location of mucoceles varied between: Frontal 7 cases (30%), Fronto-ethmoidal 6 cases (26%), Isolated Ethmoidal accounted for 3 cases (13%), sphenoidal 4 cases (17%), maxillary were 3 cases (13%) all of the 23 cases underwent endonasal endoscopic complete marsupialization, none of them required combination with external approach in-spite of different locations and complications, with no recurrence in a mean follow up period of 2.4 years. <strong>Conclusion:</strong> Endonasal endoscopic approach is a safe, efficient approach in the treatment of most paranasal sinus mucocele case in their different presentations and locations.展开更多
Industrial internet of things (IIoT) is the usage of internet of things(IoT) devices and applications for the purpose of sensing, processing andcommunicating real-time events in the industrial system to reduce the unn...Industrial internet of things (IIoT) is the usage of internet of things(IoT) devices and applications for the purpose of sensing, processing andcommunicating real-time events in the industrial system to reduce the unnecessary operational cost and enhance manufacturing and other industrial-relatedprocesses to attain more profits. However, such IoT based smart industriesneed internet connectivity and interoperability which makes them susceptibleto numerous cyber-attacks due to the scarcity of computational resourcesof IoT devices and communication over insecure wireless channels. Therefore, this necessitates the design of an efficient security mechanism for IIoTenvironment. In this paper, we propose a hyperelliptic curve cryptography(HECC) based IIoT Certificateless Signcryption (IIoT-CS) scheme, with theaim of improving security while lowering computational and communicationoverhead in IIoT environment. HECC with 80-bit smaller key and parameterssizes offers similar security as elliptic curve cryptography (ECC) with 160-bitlong key and parameters sizes. We assessed the IIoT-CS scheme security byapplying formal and informal security evaluation techniques. We used Realor Random (RoR) model and the widely used automated validation of internet security protocols and applications (AVISPA) simulation tool for formalsecurity analysis and proved that the IIoT-CS scheme provides resistance tovarious attacks. Our proposed IIoT-CS scheme is relatively less expensivecompared to the current state-of-the-art in terms of computational cost andcommunication overhead. Furthermore, the IIoT-CS scheme is 31.25% and 51.31% more efficient in computational cost and communication overhead,respectively, compared to the most recent protocol.展开更多
Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to ident...Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.展开更多
In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC c...In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.展开更多
Background: Increasing awareness level and health education can reduce the burden of Chronic Kidney Disease (CKD) at community base. Therefore, the aim of the present study was to assess the level of knowledge towards...Background: Increasing awareness level and health education can reduce the burden of Chronic Kidney Disease (CKD) at community base. Therefore, the aim of the present study was to assess the level of knowledge towards CKD manifestations in Saudi Arabia. Methodology: This is a descriptive prospective study including 900 apparently health Saudi volunteers, their ages ranging from 18 to 65 years old with a mean age of 34 years. A purposeful questionnaire was deliberated and used for obtaining data about the CKD. Results: Out of 900 contributors, 268 (29.8%) were males and 632 (70.2%) were females, giving males:females ratio of 1.00:2.36. About 102/900 (11.3%) of the participants (all of them were females) were found to believe that CKD has no specific symptoms. Conclusion: The awareness towards CKD manifestation is relatively low, which necessitates the important of community based intervention including health educational programs.展开更多
Background: The risk of CKD is high in Saudi Arabia due to increasingly growing prevalence of its risk factors, such as diabetes, hypertension and obesity. Therefore, the objective of this study was to assess the leve...Background: The risk of CKD is high in Saudi Arabia due to increasingly growing prevalence of its risk factors, such as diabetes, hypertension and obesity. Therefore, the objective of this study was to assess the level of awareness of Saudi population towards CKD risk factors in order to generate platform for future planning. Methodology: This study included 940 apparently healthy Saudi volunteers, their ages ranging from 17 to 65 years old with a mean age of 35 years. A purposeful questionnaire was designed and used for obtaining data about the CKD risk factors. Results: Out of 940 participants, 293 (31.2%) were males and 647 (68.8%) were females, giving males “females” ratio of 1.00:2.21. About 62.3% of the participants were found to believe that DM is one of the main risk factors for CKD, of whom, 74% were males and 57% were females. Approximately 60% of the participants were found believing that hypertension is one of the main risk factors for CKD, of whom 79.5% were males and 51.6% were females. Conclusion: There is an increasing in the prevalence of CKD risk factors among Saudi population. Although, the levels of awareness toward some CKD risk factors are relatively increasing, but more health education efforts are deemed importance.展开更多
In this paper, we theoretically study the quantum size effects on the electronic transmission and current density of the electrons in GaAs/AlGaAs resonant tunneling diodes by solving the coupled equations Schrodinger-...In this paper, we theoretically study the quantum size effects on the electronic transmission and current density of the electrons in GaAs/AlGaAs resonant tunneling diodes by solving the coupled equations Schrodinger-Poisson self-consistently. It is found that the resonant peaks of the trans-mission coefficients shift towards the lower energy regions as the applied bias voltage increases. Our results indicate that the transmission coefficient depends strongly on the variation of the thickness of collector and emitter. We also study the effect of the doping concentration located in the emitter and collector regions on the transmission and current density. We found that the dop-ing concentration can greatly affect the transmission coefficient and the current density;in partic-ular it increases the peak of the current density and displaces the position of the maxima of the current dependence on the applied bias voltage.展开更多
Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-d...Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-domain link is also crucial for the stability of the entire network on the data plane layer.More than one inter-domain connection enhances the scalability of the data plane layer.However,it faces a reachability problem with the principal root,which causes forwarding loops and packet drops in the network,thereby degrading network performance.The proposed solution is a multiple controller architecture;however,this approach increases the complexity and affects network performance.Thus,in this study,we propose a framework that avoids forwarding loops and packet drops without the synchronization of multiple-domain controllers in the network using an avoid loop with test packet scheme.Moreover,we collect the link status for improved routing and load balancing for the upcoming flow across inter-domain links to prevent congestion and increase throughput in real time.Our proposed methodology can significantly reduce the controller workload against multiple controller architecture,minimize flow setup latency,and improve throughput.展开更多
Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications.A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scal...Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications.A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scale is soaking them in lower alcohols,such as methanol and ethanol.However,this procedure does not seem applicable at industrial level,and other strategies must be investigated.In this work,a regeneration method with alcohol vapors(ethanol or methanol)was developed to recover permeability of aged PIM-1 membranes,in comparison with the conventional soaking-in-liquid approach.The gas permeability and separation performance,before and post the regeneration methods,were assessed using a binary mixture of CO_(2) and CH_(4)(1:1,v:v).Our results show that an 8-hour methanol vapor treatment was sufficient to recover the original gas permeability,reaching a CO_(2) permeability>7000 barrer.展开更多
In the framework of effective mass approximation, we theoretically investigate the electronic structure of the Si δ-doped InAIN/GaN single quantum well by solving numerically the coupled equations Schrodinger-Poisson...In the framework of effective mass approximation, we theoretically investigate the electronic structure of the Si δ-doped InAIN/GaN single quantum well by solving numerically the coupled equations Schrodinger-Poisson self-consistently. The linear, nonlinear optical absorption coefficients and relative refractive index changes are calculated as functions of the doping concentration and its thickness. The obtained results show that the position and the amplitude of the linear and total optical absorption coefficients and the refractive index changes can be modified by varying the doping concentration and its thickness. In addition, it is found that the maximum of the optical absorption can be red-shifted or blue-shifted by varying the doping concentration. The obtained results are important for the design of various electronic components such as high-power FETs and infrared photonic devices.展开更多
In this work,the electronic properties of resonant tunneling diodes（RTDs） based on GaN-AlxGa（1-x）N double barriers are investigated by using the non-equilibrium Green functions formalism（NEG）.These materials eac...In this work,the electronic properties of resonant tunneling diodes（RTDs） based on GaN-AlxGa（1-x）N double barriers are investigated by using the non-equilibrium Green functions formalism（NEG）.These materials each present a wide conduction band discontinuity and a strong internal piezoelectric field,which greatly affect the electronic transport properties.The electronic density,the transmission coefficient,and the current–voltage characteristics are computed with considering the spontaneous and piezoelectric polarizations.The influence of the quantum size on the transmission coefficient is analyzed by varying GaN quantum well thickness,AlxGa1-xN width,and the aluminum concentration xAl.The results show that the transmission coefficient more strongly depends on the thickness of the quantum well than the barrier;it exhibits a series of resonant peaks and valleys as the quantum well width increases.In addition,it is found that the negative differential resistance（NDR） in the current–voltage（I–V） characteristic strongly depends on aluminum concentration xAl.It is shown that the peak-to-valley ratio（PVR） increases with xAlvalue decreasing.These findings open the door for developing vertical transport nitrides-based ISB devices such as THz lasers and detectors.展开更多
Background/Aims: The aim of this study was to evaluate and assess the knowledge and attitude to dose and associated risks caused by Ionizing Radiation (IR) procedures among patients. Methods: This was a cross-sectiona...Background/Aims: The aim of this study was to evaluate and assess the knowledge and attitude to dose and associated risks caused by Ionizing Radiation (IR) procedures among patients. Methods: This was a cross-sectional study involving 375 consecutive patients, conducted over a period of 4 months from at the radiology unit of King Khalid Hospital in Najran for IR procedures using self-administered questionnaires that was developed and distributed with consents and instructions to the participants. Results: About three-quarter (60%) of the patients reported not being worried to undergo radiological tests. The same proportion of the patients also would not have radiological tests if they can tolerate the disease. About half (50%) of the respondents stated that they would not be satisfied if no further radiological tests were required and 52% did not think that radiological procedures can cause hazards and side effects to the body. Also, over half (53%) of the patients reported not knowing that radiological tests can cause cancer;48% would not repeat the radiological tests within six months;and about 69% did not know the importance of Radiology for diagnosis. Conclusion: There is relatively low knowledge and awareness of the risks associated with Ionizing Radiation among patients in the study population. Therefore, there is a need for educating the public and not only medical personnel, about radiation exposure and associated risks.展开更多
Background: The incidence of breast cancer is increasing in Saudi Arabia, chiefly in distant provinces with cases assigning advanced stages of the disease. This study aimed to evaluate the level of knowledge towards e...Background: The incidence of breast cancer is increasing in Saudi Arabia, chiefly in distant provinces with cases assigning advanced stages of the disease. This study aimed to evaluate the level of knowledge towards external exposure related to breast cancer risk factors in Qurayyat, Northern Saudi Arabia. Methodology: This descriptive study included 724 Saudi volunteers living in the city of Qurayyat, Northern Saudi Arabia. For females, only those agreeing to participate in the breast self-examination workshop were included and were further investigated for the presence of breast lumps. Results: In comparison of females vs. males, as for the point “Do you know food increases or decreases the risk of BC”, 92 (15%) women stated “Yes (Some prevented BC)” vs. 24 (24%) of the men;78 (12.5%) women stated “Yes (Some caused BC)” vs. 25 (25%) of the men. Referring to the socket “Overweight or obesity increases the risk of BC”, 290 (46.5%) women stated “Yes” vs. 53 (53%) of the men. As for the inquiry “Viruses can increase the risk of BC”, 370 (60%) women stated “Yes” vs. 49 (49%) of the men. Conclusion: There is a lack of breast cancer awareness in Northern Saudi Arabia with the existence of many women with undetected breast lumps. BSE is cost-effective, and it can be implemented in such inaccessible areas.展开更多
Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfact...Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smooth-ly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.展开更多
Background:Clostridium perfringens-induced chicken necrotic enteritis(NE)is responsible for substantial economic losses worldwide annually.Recently,as a result of antibiotic growth promoter prohibition,the prevalence ...Background:Clostridium perfringens-induced chicken necrotic enteritis(NE)is responsible for substantial economic losses worldwide annually.Recently,as a result of antibiotic growth promoter prohibition,the prevalence of NE in chickens has reemerged.This study was aimed to reduce NE through titrating dietary deoxycholic acid(DCA)as an effective antimicrobial alternative.Materials and methods:Day-old broiler chicks were assigned to six groups and fed diets supplemented with 0(basal diet),0.8,1.0 and 1.5 g/kg(on top of basal diet)DCA.The birds were challenged with Eimeria maxima(20,000 oocysts/bird)at d 18 and C.perfringens(109 CFU/bird per day)at d 23,24,and 25 to induce NE.The birds were sacrificed at d 26 when ileal tissue and digesta were collected for analyzing histopathology,mRNA accumulation and C.perfringens colonization by real-time PCR,targeted metabolomics of bile acids,fluorescence in situ hybridization(FISH),or terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assay.Results:At the cellular level,birds infected with E.maxima and C.perfringens developed subclinical NE and showed shortening villi,crypt hyperplasia and immune cell infiltration in ileum.Dietary DCA alleviated the NE-induced ileal inflammation in a dose-dependent manner compared to NE control birds.Consistent with the increased histopathological scores,subclinical NE birds suffered body weight gain reduction compared to the uninfected birds,an effect attenuated with increased doses of dietary DCA.At the molecular level,the highest dose of DCA at 1.5 g/kg reduced C.perfringens luminal colonization compared to NE birds using PCR and FISH.Furthermore,the dietary DCA reduced subclinical NE-induced intestinal inflammatory gene expression and cell apoptosis using PCR and TUNEL assays.Upon further examining ileal bile acid pool through targeted metabolomics,subclinical NE reduced the total bile acid level in ileal digesta compared to uninfected birds.Notably,dietary DCA increased total bile acid and DCA levels in a dose-dependent ma展开更多
An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of qui...An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of quinoline proceeded smoothly under mild reaction conditions(low H2 pressure and temperature)to yield 1,2,3,4‐tetrahydroquinolines(py‐THQs)in satisfactory to excellent yields.Various synthetically useful functional groups,such as halogen,hydroxyl,formyl,ethoxycarbonyl,and aminocarbonyl groups,remained intact during the quinoline hydrogenation.No palladium was leached from PdNPore during the hydrogenation reaction.Moreover,the catalyst was easily recovered and reused without any loss of catalytic activity.The results of kinetic,deuterium‐hydrogen exchange,and deuterium‐labeling experiments indicated that the present hydrogenation involves heterolytic H2 splitting on the surface of the catalyst.展开更多
基金financial support by Universiti Teknologi PETRONAS (No. YUTP-0153AA-E70)
文摘This paper presents the rheological behaviour of supercritical CO2 （sCO2） foam at reser- voir conditions of I 500 psi and 80 ℃. Different commercial surfactants were screened and utilized in or- der to generate a fairly stable CO2 foam. Mixed surfactant system was also introduced to generate strong foam. Foam rheology was studied for some specific foam qualities using a high pressure high tempera- ture （HPHT） foam loop rheometer. A typical shear thinning behaviour of the foam was observed and a significant increase in the foam viscosity was noticed with the increase of foam quality until 85%. A de- sired high apparent viscosity with coarse texture was found at 85% foam quality. Foam visualization above 85% showed an unstable foam due to extremely thin lamella which collapsed and totally disap- peared in the loop rheometer. Below 52%, a non-homogenous and unstable foam was found having low viscosity with some liquid accumulation at the bottom of the circulation loop. This research has demon- strated rheology of sCO2 foams at different qualities at HPHT to obtain optimal foam quality region for immiscible CO2 foam co-injection process.
基金funded by Institutional Fund Projects under Grant No(IFPNC-001-611-2020).
文摘Landmines continue to pose an ongoing threat in various regions around the world,with countless buried landmines affecting numerous human lives.The detonation of these landmines results in thousands of casualties reported worldwide annually.Therefore,there is a pressing need to employ diverse landmine detection techniques for their removal.One effective approach for landmine detection is UAV(Unmanned Aerial Vehicle)based AirborneMagnetometry,which identifies magnetic anomalies in the local terrestrial magnetic field.It can generate a contour plot or heat map that visually represents the magnetic field strength.Despite the effectiveness of this approach,landmine removal remains a challenging and resource-intensive task,fraughtwith risks.Edge computing,on the other hand,can play a crucial role in critical drone monitoring applications like landmine detection.By processing data locally on a nearby edge server,edge computing can reduce communication latency and bandwidth requirements,allowing real-time analysis of magnetic field data.It enables faster decision-making and more efficient landmine detection,potentially saving lives and minimizing the risks involved in the process.Furthermore,edge computing can provide enhanced security and privacy by keeping sensitive data close to the source,reducing the chances of data exposure during transmission.This paper introduces the MAGnetometry Imaging based Classification System(MAGICS),a fully automated UAV-based system designed for landmine and buried object detection and localization.We have developed an efficient deep learning-based strategy for automatic image classification using magnetometry dataset traces.By simulating the proposal in various network scenarios,we have successfully detected landmine signatures present in themagnetometry images.The trained models exhibit significant performance improvements,achieving a maximum mean average precision value of 97.8%.
文摘In this review article, various preferences in breast plastic surgery particularly after breast cancer will be discussed in view of the diverse indications for the different construction procedures. The various conditions that necessitate the need for reconstruction are appraised, the important reconstructive procedures are discussed. The most important indications procedures discussed in this review include;Prophylactic subcutaneous mastectomy, Lumpectomy and Radiation, Modified Mastectomy with Axillary Sampling, Nipple reconstruction, and the contralateral breast. These procedures are discussed in view of plastic surgeon practice and patients acceptability in Saudi Arabia. Data from Saudi Arabia in particular was identified through searches of the EMBASE, and MEDLINE database, using the keywords: Saudi Arabia, breast plastic Surgery, breast reconstruction, autologous breast reconstruction, breast augmentation. Advances in prosthetic technologies and modifications in autologous flap techniques, and the development of novel tissue alternatives have allowed for sustained developments in breast reconstruction results. A variety of attitudes has been accessible for addressing the difficulties that endure after resection of breast cancer in Saudi Arabia. Patients should be educated to accept different process in this context.
文摘<strong>Introduction:</strong> Paranasal sinuses mucoceles are benign, epithelial lined, mucus filled lesions, causing destruction of the adjacent sinus walls, and with further gradual extension to adjacent structures, serious morbidities and mortalities may occur. <strong>Objective:</strong> To emphasize on the efficacy of endonasal endoscopic marsupialization in the treatment of paranasal sinus mucoceles. <strong>Method:</strong> Retrospective descriptive study on paranasal sinus mucocele cases operated on endoscopically by the author (AAM), in the 10-year-period from to 2009-2019. <strong>Result:</strong> Total of 23 cases were included, 16 were males and 7 females, age ranging between 14 - 76 years, with a mean age of 45 years Location of mucoceles varied between: Frontal 7 cases (30%), Fronto-ethmoidal 6 cases (26%), Isolated Ethmoidal accounted for 3 cases (13%), sphenoidal 4 cases (17%), maxillary were 3 cases (13%) all of the 23 cases underwent endonasal endoscopic complete marsupialization, none of them required combination with external approach in-spite of different locations and complications, with no recurrence in a mean follow up period of 2.4 years. <strong>Conclusion:</strong> Endonasal endoscopic approach is a safe, efficient approach in the treatment of most paranasal sinus mucocele case in their different presentations and locations.
基金This work is supported by the University of Malaya IIRG Grant(IIRG008A-19IISSN),Ministry of Education FRGS Grant(FP055-2019A)This work was also supported by Grant System of University of Zilina No.1/2020.(Project No.7962)partially supported by the Slovak Grant Agency for Science(VEGA)under Grant Number 1/0157/21.The authors are grateful to the Taif University Researchers Supporting Project(Number TURSP-2020/36),Taif University,Taif,Saudi Arabia.
文摘Industrial internet of things (IIoT) is the usage of internet of things(IoT) devices and applications for the purpose of sensing, processing andcommunicating real-time events in the industrial system to reduce the unnecessary operational cost and enhance manufacturing and other industrial-relatedprocesses to attain more profits. However, such IoT based smart industriesneed internet connectivity and interoperability which makes them susceptibleto numerous cyber-attacks due to the scarcity of computational resourcesof IoT devices and communication over insecure wireless channels. Therefore, this necessitates the design of an efficient security mechanism for IIoTenvironment. In this paper, we propose a hyperelliptic curve cryptography(HECC) based IIoT Certificateless Signcryption (IIoT-CS) scheme, with theaim of improving security while lowering computational and communicationoverhead in IIoT environment. HECC with 80-bit smaller key and parameterssizes offers similar security as elliptic curve cryptography (ECC) with 160-bitlong key and parameters sizes. We assessed the IIoT-CS scheme security byapplying formal and informal security evaluation techniques. We used Realor Random (RoR) model and the widely used automated validation of internet security protocols and applications (AVISPA) simulation tool for formalsecurity analysis and proved that the IIoT-CS scheme provides resistance tovarious attacks. Our proposed IIoT-CS scheme is relatively less expensivecompared to the current state-of-the-art in terms of computational cost andcommunication overhead. Furthermore, the IIoT-CS scheme is 31.25% and 51.31% more efficient in computational cost and communication overhead,respectively, compared to the most recent protocol.
基金CM.and B.S.gratefully acknowledge financial support from the NASA Spce Tochnology Gaduate Research Opportunites Felowship(Grants:8ONSSC19K1164 and 8ONSSC17K0084,SD.and T.MP.gratefully acknowiedge fnanchl support from the Natonal Sclonce Found ation Uward 1984641)patt of the HDR IDEAS Insatute.The authors additonally thank Aaron Engel for the suggeston for this project and Dr Neal Brodnik for an Introduction to tSNE。
文摘Damage mechanism identification has scientific and practical ramifications for the structural health monitoring,design,and application of composite systems.Recent advances in machine learning uncover pathways to identify the waveform-damage mechanism relationship in higher-dimensional spaces for a comprehensive understanding of damage evolution.This review evaluates the state of the field,beginning with a physics-based understanding of acoustic emission waveform feature extraction,followed by a detailed overview of waveform clustering,labeling,and error analysis strategies.Fundamental requirements for damage mechanism identification in any machine learning framework,including those currently in use,under development,and yet to be explored,are discussed.
基金C.M.and B.S.gratefully acknowledge financial support from the NASA Space Technology Research Grant Program(Grants:80NSSC19K1164 and 80NSSC17K0084)S.D.and T.M.P.gratefully acknowledge financial support from the National Science Foundation(Award:1934641)as part of the HDR IDEAS2 Institute.The authors thank Abed Musaffar for creating the CAD schematic in Fig.1a and thank Dr.Neal Brodnik for a detailed introduction to t-SNE.
文摘In this work,we demonstrate that damage mechanism identification from acoustic emission(AE)signals generated in minicomposites with elastically similar constituents is possible.AE waveforms were generated by SiC/SiC ceramic matrix minicomposites(CMCs)loaded under uniaxial tension and recorded by four sensors(two models with each model placed at two ends).Signals were encoded with a modified partial power scheme and subsequently partitioned through spectral clustering.Matrix cracking and fiber failure were identified based on the frequency information contained in the AE event they produced,despite the similar constituent elastic properties of the matrix and fiber.Importantly,the resultant identification of AE events closely followed CMC damage chronology,wherein early matrix cracking is later followed by fiber breaks,even though the approach is fully domain-knowledge agnostic.Additionally,the partitions were highly precise across both the model and location of the sensors,and the partitioning was repeatable.The presented approach is promising for CMCs and other composite systems with elastically similar constituents.
文摘Background: Increasing awareness level and health education can reduce the burden of Chronic Kidney Disease (CKD) at community base. Therefore, the aim of the present study was to assess the level of knowledge towards CKD manifestations in Saudi Arabia. Methodology: This is a descriptive prospective study including 900 apparently health Saudi volunteers, their ages ranging from 18 to 65 years old with a mean age of 34 years. A purposeful questionnaire was deliberated and used for obtaining data about the CKD. Results: Out of 900 contributors, 268 (29.8%) were males and 632 (70.2%) were females, giving males:females ratio of 1.00:2.36. About 102/900 (11.3%) of the participants (all of them were females) were found to believe that CKD has no specific symptoms. Conclusion: The awareness towards CKD manifestation is relatively low, which necessitates the important of community based intervention including health educational programs.
文摘Background: The risk of CKD is high in Saudi Arabia due to increasingly growing prevalence of its risk factors, such as diabetes, hypertension and obesity. Therefore, the objective of this study was to assess the level of awareness of Saudi population towards CKD risk factors in order to generate platform for future planning. Methodology: This study included 940 apparently healthy Saudi volunteers, their ages ranging from 17 to 65 years old with a mean age of 35 years. A purposeful questionnaire was designed and used for obtaining data about the CKD risk factors. Results: Out of 940 participants, 293 (31.2%) were males and 647 (68.8%) were females, giving males “females” ratio of 1.00:2.21. About 62.3% of the participants were found to believe that DM is one of the main risk factors for CKD, of whom, 74% were males and 57% were females. Approximately 60% of the participants were found believing that hypertension is one of the main risk factors for CKD, of whom 79.5% were males and 51.6% were females. Conclusion: There is an increasing in the prevalence of CKD risk factors among Saudi population. Although, the levels of awareness toward some CKD risk factors are relatively increasing, but more health education efforts are deemed importance.
文摘In this paper, we theoretically study the quantum size effects on the electronic transmission and current density of the electrons in GaAs/AlGaAs resonant tunneling diodes by solving the coupled equations Schrodinger-Poisson self-consistently. It is found that the resonant peaks of the trans-mission coefficients shift towards the lower energy regions as the applied bias voltage increases. Our results indicate that the transmission coefficient depends strongly on the variation of the thickness of collector and emitter. We also study the effect of the doping concentration located in the emitter and collector regions on the transmission and current density. We found that the dop-ing concentration can greatly affect the transmission coefficient and the current density;in partic-ular it increases the peak of the current density and displaces the position of the maxima of the current dependence on the applied bias voltage.
基金The authors are grateful to the University of Malakand and University ofMalaya for providing fund for this project.The authors are grateful to the Taif University Researchers Supporting Project(number TURSP-2020/36),Taif University,Taif,Saudi ArabiaThis research work was also partially supported by the Faculty of Computer Science and Information Technology,University of Malaya,under Postgraduate Research Grant PG035-2016A.
文摘Software-defined networking(SDN)makes network agile and flexible due to its programmable approach.An extensive network has multiple domains in SDN for the scalability and performance of the network.However,the inter-domain link is also crucial for the stability of the entire network on the data plane layer.More than one inter-domain connection enhances the scalability of the data plane layer.However,it faces a reachability problem with the principal root,which causes forwarding loops and packet drops in the network,thereby degrading network performance.The proposed solution is a multiple controller architecture;however,this approach increases the complexity and affects network performance.Thus,in this study,we propose a framework that avoids forwarding loops and packet drops without the synchronization of multiple-domain controllers in the network using an avoid loop with test packet scheme.Moreover,we collect the link status for improved routing and load balancing for the upcoming flow across inter-domain links to prevent congestion and increase throughput in real time.Our proposed methodology can significantly reduce the controller workload against multiple controller architecture,minimize flow setup latency,and improve throughput.
基金Faiz Almansour is grateful to the Department of Research&Development,Saudi Aramco for funding and supporting his Ph.D.studies.M.Alberto is grateful to EPSRC for funding under the research grant number EP/S032258/1R.Bhavsar to EPSRC under grant number EP/M001342/1.
文摘Physical aging is currently a major obstacle for the commercialization of PIM-1 membranes for gas separation applications.A well-known approach to reversing physical aging effects of PIM-1 membranes at laboratory scale is soaking them in lower alcohols,such as methanol and ethanol.However,this procedure does not seem applicable at industrial level,and other strategies must be investigated.In this work,a regeneration method with alcohol vapors(ethanol or methanol)was developed to recover permeability of aged PIM-1 membranes,in comparison with the conventional soaking-in-liquid approach.The gas permeability and separation performance,before and post the regeneration methods,were assessed using a binary mixture of CO_(2) and CH_(4)(1:1,v:v).Our results show that an 8-hour methanol vapor treatment was sufficient to recover the original gas permeability,reaching a CO_(2) permeability>7000 barrer.
基金Supported by the Deanship of Scientific Research of University of Dammam under Grant No 2015134
文摘In the framework of effective mass approximation, we theoretically investigate the electronic structure of the Si δ-doped InAIN/GaN single quantum well by solving numerically the coupled equations Schrodinger-Poisson self-consistently. The linear, nonlinear optical absorption coefficients and relative refractive index changes are calculated as functions of the doping concentration and its thickness. The obtained results show that the position and the amplitude of the linear and total optical absorption coefficients and the refractive index changes can be modified by varying the doping concentration and its thickness. In addition, it is found that the maximum of the optical absorption can be red-shifted or blue-shifted by varying the doping concentration. The obtained results are important for the design of various electronic components such as high-power FETs and infrared photonic devices.
基金Project supported by the Deanship of Scientific Research of University of Dammam(Grant No.2014137)
文摘In this work,the electronic properties of resonant tunneling diodes（RTDs） based on GaN-AlxGa（1-x）N double barriers are investigated by using the non-equilibrium Green functions formalism（NEG）.These materials each present a wide conduction band discontinuity and a strong internal piezoelectric field,which greatly affect the electronic transport properties.The electronic density,the transmission coefficient,and the current–voltage characteristics are computed with considering the spontaneous and piezoelectric polarizations.The influence of the quantum size on the transmission coefficient is analyzed by varying GaN quantum well thickness,AlxGa1-xN width,and the aluminum concentration xAl.The results show that the transmission coefficient more strongly depends on the thickness of the quantum well than the barrier;it exhibits a series of resonant peaks and valleys as the quantum well width increases.In addition,it is found that the negative differential resistance（NDR） in the current–voltage（I–V） characteristic strongly depends on aluminum concentration xAl.It is shown that the peak-to-valley ratio（PVR） increases with xAlvalue decreasing.These findings open the door for developing vertical transport nitrides-based ISB devices such as THz lasers and detectors.
文摘Background/Aims: The aim of this study was to evaluate and assess the knowledge and attitude to dose and associated risks caused by Ionizing Radiation (IR) procedures among patients. Methods: This was a cross-sectional study involving 375 consecutive patients, conducted over a period of 4 months from at the radiology unit of King Khalid Hospital in Najran for IR procedures using self-administered questionnaires that was developed and distributed with consents and instructions to the participants. Results: About three-quarter (60%) of the patients reported not being worried to undergo radiological tests. The same proportion of the patients also would not have radiological tests if they can tolerate the disease. About half (50%) of the respondents stated that they would not be satisfied if no further radiological tests were required and 52% did not think that radiological procedures can cause hazards and side effects to the body. Also, over half (53%) of the patients reported not knowing that radiological tests can cause cancer;48% would not repeat the radiological tests within six months;and about 69% did not know the importance of Radiology for diagnosis. Conclusion: There is relatively low knowledge and awareness of the risks associated with Ionizing Radiation among patients in the study population. Therefore, there is a need for educating the public and not only medical personnel, about radiation exposure and associated risks.
文摘Background: The incidence of breast cancer is increasing in Saudi Arabia, chiefly in distant provinces with cases assigning advanced stages of the disease. This study aimed to evaluate the level of knowledge towards external exposure related to breast cancer risk factors in Qurayyat, Northern Saudi Arabia. Methodology: This descriptive study included 724 Saudi volunteers living in the city of Qurayyat, Northern Saudi Arabia. For females, only those agreeing to participate in the breast self-examination workshop were included and were further investigated for the presence of breast lumps. Results: In comparison of females vs. males, as for the point “Do you know food increases or decreases the risk of BC”, 92 (15%) women stated “Yes (Some prevented BC)” vs. 24 (24%) of the men;78 (12.5%) women stated “Yes (Some caused BC)” vs. 25 (25%) of the men. Referring to the socket “Overweight or obesity increases the risk of BC”, 290 (46.5%) women stated “Yes” vs. 53 (53%) of the men. As for the inquiry “Viruses can increase the risk of BC”, 370 (60%) women stated “Yes” vs. 49 (49%) of the men. Conclusion: There is a lack of breast cancer awareness in Northern Saudi Arabia with the existence of many women with undetected breast lumps. BSE is cost-effective, and it can be implemented in such inaccessible areas.
文摘Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smooth-ly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.
基金This research was supported grants of Arkansas Biosciences Institute,USDA National Institute of Food and Agriculture(NIFA)Hatch project 1012366USDA NIFA Hatch/Multi State project 1018699,USDA NIFA project 2018–06686 to X.
文摘Background:Clostridium perfringens-induced chicken necrotic enteritis(NE)is responsible for substantial economic losses worldwide annually.Recently,as a result of antibiotic growth promoter prohibition,the prevalence of NE in chickens has reemerged.This study was aimed to reduce NE through titrating dietary deoxycholic acid(DCA)as an effective antimicrobial alternative.Materials and methods:Day-old broiler chicks were assigned to six groups and fed diets supplemented with 0(basal diet),0.8,1.0 and 1.5 g/kg(on top of basal diet)DCA.The birds were challenged with Eimeria maxima(20,000 oocysts/bird)at d 18 and C.perfringens(109 CFU/bird per day)at d 23,24,and 25 to induce NE.The birds were sacrificed at d 26 when ileal tissue and digesta were collected for analyzing histopathology,mRNA accumulation and C.perfringens colonization by real-time PCR,targeted metabolomics of bile acids,fluorescence in situ hybridization(FISH),or terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)assay.Results:At the cellular level,birds infected with E.maxima and C.perfringens developed subclinical NE and showed shortening villi,crypt hyperplasia and immune cell infiltration in ileum.Dietary DCA alleviated the NE-induced ileal inflammation in a dose-dependent manner compared to NE control birds.Consistent with the increased histopathological scores,subclinical NE birds suffered body weight gain reduction compared to the uninfected birds,an effect attenuated with increased doses of dietary DCA.At the molecular level,the highest dose of DCA at 1.5 g/kg reduced C.perfringens luminal colonization compared to NE birds using PCR and FISH.Furthermore,the dietary DCA reduced subclinical NE-induced intestinal inflammatory gene expression and cell apoptosis using PCR and TUNEL assays.Upon further examining ileal bile acid pool through targeted metabolomics,subclinical NE reduced the total bile acid level in ileal digesta compared to uninfected birds.Notably,dietary DCA increased total bile acid and DCA levels in a dose-dependent ma
基金supported by the National Natural Science Foundation of China(21573032,21773021)the Fundamental Research Funds for the Central Universities(DUT17ZD212)the International Scientific Partnership Program ISPP at King Saud University for funding this research work through ISPP#0048~~
文摘An efficient and highly chemoselective heterogeneous catalyst system for quinoline hydrogenation was developed using unsupported nanoporous palladium(PdNPore).The PdNPore‐catalyzed chemoselective hydrogenation of quinoline proceeded smoothly under mild reaction conditions(low H2 pressure and temperature)to yield 1,2,3,4‐tetrahydroquinolines(py‐THQs)in satisfactory to excellent yields.Various synthetically useful functional groups,such as halogen,hydroxyl,formyl,ethoxycarbonyl,and aminocarbonyl groups,remained intact during the quinoline hydrogenation.No palladium was leached from PdNPore during the hydrogenation reaction.Moreover,the catalyst was easily recovered and reused without any loss of catalytic activity.The results of kinetic,deuterium‐hydrogen exchange,and deuterium‐labeling experiments indicated that the present hydrogenation involves heterolytic H2 splitting on the surface of the catalyst.
