642 research outputs found

    Clinico-Pathological Measures and Management of Mucinous Ovarian Cancer: Single Institutional Study

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    Background: Mucinous ovarian cancer is less common and less aggressive epithelial ovarian cancer, which represents 3% of epithelial ovarian cancer. Patient and methods: A retrospective descriptive analysis involving all patients with mucinous ovarian cancer who underwent surgical management or referred to National Cancer Institute (NCI), Cairo University (CU), from January 2010 to January 2020. Of 46 cases reviewed. 16 cases were excluded (10 cases had metastatic and 6 cases had incomplete data). Results: forty-six cases reviewed with median age of 48.3±18.1 years. Half of patients were in premenopausal status. Patients presented with distention with or without pain were 70% of cases, 10% of patients with abdominal mass and 6.7% of patients with bleeding. Most of cases 63.30% were diagnosed at late stages (1C and beyond). Patients had unilateral disease were 70% of cases and had elevated tumor markers were 53.3 % of cases. The most commonly elevated tumor marker was CA 125 (26.7%). Patients had comorbidities were 30% of cases. Surgery was the main line of management. Total abdominal hysterectomy and bilateral salpingo-oophorectomy plus infracolic omentectomy were done in 73.3% of patients, 6.7% underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy, 3.3% underwent cytoreductive surgery and 3.3% underwent cytoreductive surgery and 13% of patients underwent fertility sparing surgery. The role of pelvic lymphadenectomy was limited (13.3% underwent pelvic lymphadenectomy and only one patient had positive lymph node metastasis). Conclusion: The most important prognostic factors were disease stage, laterality, tumor markers and performance status

    Impacts of symmetrical and asymmetrical voltage sags on DFIG-based wind turbines considering phase-angle jump, voltage recovery, and sag parameters

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    This paper presents a new analysis into the impacts of various symmetrical and asymmetrical voltage sags on doubly fed induction generator (DFIG)-based wind turbines. Fault ride-through requirements are usually defined by the grid codes at the point of common coupling (PCC) of wind farms to the power network. However, depending on the network characteristics and constraints, the voltage sag conditions experienced at the wind generator terminals can be significantly different from the conditions at the PCC. Therefore, it is very important to identify the voltage sags that can practically affect the operation of wind generators. Extensive simulation studies are carried out in MATLAB/Simulink to investigate the transient overshoots and ripples that appear in the rotor current and dc-link voltage when the DFIG is subjected to various types of (a)symmetrical faults. For the first time, the impacts of phase-angle jump and operational constraints of circuit breakers are examined. Furthermore, the influences of sag parameters including type, initial point-on-wave instant, depth, and impedance angle are investigated. Complementary theoretical analyses are also presented to support the validity of observations made in the simulation studies

    Machine Learning in Model-Based Forest Height Inversion

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    Model-based (PM) forest height inversion from Polarimetric Interferometric Synthetic Aperture Radar (Pol-InSAR) measurements is today an established application demonstrated and validated at large scales for a wide variety of boreal and tropical forest sites at different frequencies (from X- down to P- band) ​[1], [2]​. Although the estimation performance obtained may depend on the individual observation spaces in each case, it is generally (very) convincing. However, as with any model-based inversion approach, there are inherent limitations that can restrict expected performance depending on the individual case ​[3]​

    Magnetic localization and control of helical robots for clearing superficial blood clots

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    This work presents an approach for the localization and control of helical robots during removal of superficial blood clots inside in vitro and ex vivo models. The position of the helical robot is estimated using an array of Hall-effect sensors and precalculated magnetic field map of two synchronized rotating dipole fields. The estimated position is used to implement closed-loop motion control of the helical robot using the rotating dipole fields. We validate the localization accuracy by visual feedback and feature tracking inside the in vitro model. The experimental results show that the magnetic localization of a helical robot with diameter of 1 mm can achieve a mean absolute position error of 2.35 ± 0.4 mm (n = 20). The simultaneous localization and motion control of the helical robot enables propulsion toward a blood clot and clearing at an average removal rate of 0.67 ± 0.47 mm3/min. This method is used to localize the helical robot inside a rabbit aorta (ex vivo model), and the localization accuracy is validated using ultrasound feedback with a mean absolute position error of 2.6 mm

    Airport service performance at Abu Dhabi International Airport

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    To acquire a significant footing in today’s competitive airport environments, enhancing airport service performance for passengers is essential. This study aims to investigate the relationship between queuing time, prime services, security screening, and service performance at Abu Dhabi International Airport in the United Arab Emirates (UAE). A quantitative methodology was employed. The sample size for the PLS-SEM analysis and the passengers’ airport service performance was determined to be 230 respondents. The results revealed a significant relationship between queuing time, prime services, security screening, and airport service performance. The findings also demonstrated a significant positive relationship between queuing time and airport service performance (β = 0.193, t = 3.564, p ≤ 0.000), a significant positive relationship between prime services and airport service performance (β = 0.478, t = 9.225, p ≤ 0.000), and a significant positive relationship between security screening and airport service performance (β= 0.227, t = 4.196, p ≤ 0.000). The outcomes are anticipated to support Abu Dhabi International Airport management in making efficient processes to augment airport service accomplishment for passengers from UAE and different countries

    Assessment of uncertainties in projected temperature and precipitation over the Arabian Peninsula using three categories of CMIP5 multimodel ensembles

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    Background: Projections of temperature and precipitation with low uncertainties are key parameters to climate change related studies. Purpose: The projected temperature and precipitation and their uncertainties over the Arabian Peninsula for the 21st century for three CMIP5 multimodel ensembles under RCP4.5 and RCP8.5 are examined in this paper. Methods: Analyzing the performance of 30 CMIP5 model individually, they are categorized into three groups for the present climate (1976–2005). By applying simple model averaging ensemble method, three multimodel ensemble means, namely: (i) all CMIP5 models ensemble (AME), (ii) selected CMIP5 models ensemble (SME), and (iii) best-performing CMIP5 models ensemble (BME) are developed. Results Over the Arabian Peninsula, a continuous rise in temperature is obtained in all three ensembles (i.e., AME, SME, and BME) in the 21st century. The BME shows enhanced changes in temperature at the end of 21st century as compared to AME and SME. Moreover, the BME shows a remarkable reduction in uncertainties for the projected temperature. The AME, SME, and BME show strong inter-annual variability for the projected precipitation over the peninsula. Compared to AME and SME, the BME revealed enhanced positive change in the annual mean precipitation by the end of 21st century. Conclusions: Regionally, southern/northwestern areas of the peninsula receive enhanced/reduced future precipitation as compared to the present climate. The diferences in the projected precipitation and temperature signals increase largely between the three ensembles towards the end of 21st century. Therefore, it is concluded that selecting the best-performing models may lead a better planning by the policy makers and stakeholder for the region

    Assessment of uncertainties in projected temperature and precipitation over the Arabian Peninsula a comparison between different categories of CMIP3 models

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    Background: This paper examined the level of uncertainties in precipitation and temperature simulations by Coupled Model Intercomparison Project Phase 3 (CMIP3) over the Arabian Peninsula. Purpose: Different techniques are employed to assess the ranges of uncertainties in projected temperature and precipitation over the Arabian Peninsula. Methods: For the present climate (1970–1999), the 22 CMIP3 models are grouped into four out of which two main categories, i) all models ensemble and ii) best performing models ensemble, are used to assess the uncertainties in the future temperature and precipitation over the Arabian Peninsula. Results: The CMIP3 ensemble projections for the above two main categories revealed a continuous increase in temperature over the peninsula during the 21st century. For the period 2070–2099, the all (best performing) models ensemble revealed an increase in temperature by 2.32 ± 2.45 (3.85 ± 1.54), 3.49 ± 2.49 (4.91 ± 1.61), and 3.28 ± 1.47 (5.36 ± 1.47) C, relative to the present climate, under the B1, A1B, and A2 scenario, respectively, while the intermodel ranges are projected to be from -3.36 to 6.08 (0.84 to 5.96), -2.26 to 7.68 (1.94 to 7.29), and -1.79 to 7.40 (2.75 to 7.10) C, respectively. Meanwhile, for the same period, the annual precipitation is projected to increase by 5.16 ± 30 (3.2 ± 25), 10.48 ± 34 (1.82 ± 28), and 15.29 ± 43 (5.3 ± 32)%, relative to the present climate under the B1, A1B, and A2 scenario, while the intermodel ranges are projected to be from -94 to 265 (-71 to 175), -95 to 322 (-74 to 205), and -95 to 375 (-75 to 235)%, respectively, for all (best performing) models ensemble. Conclusion The uncertainty of projected temperature and precipitation is reduced in the best performing models ensemble compared to the all models. At annual scale, surplus (deficit) precipitation pattern is projected across southern and southwestern (northern and northwestern) parts of the peninsula. The above results indicate that a better choice of models from the CMIP3 database could reduce the uncertainty range associated with future projections over the Arabian Peninsula

    Identification of Aerosol Pollution Hotspots in Jiangsu Province of China

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    Aerosol optical depth (AOD) is an important atmospheric parameter for climate change assessment, human health, and for total ecological situation studies both regionally and globally. This study used 21-year (2000–2020) high-resolution (1 km) Multiangle Implementation of Atmospheric Correction (MAIAC) algorithm-based AOD from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the Terra and Aqua satellites. MAIAC AOD was evaluated against Aerosol Robotic Network (AERONET) data across three sites (Xuzhou-CUMT, NUIST, and Taihu) located in Jiangsu Province. The study also investigated the spatiotemporal distributions and variations in AOD, with associated trends, and measured the impact of meteorology on AOD in the 13 cities of Jiangsu Province. The evaluation results demonstrated a high correlation (r = 0.867~0.929) between MAIAC AOD and AERONET data, with lower root mean squared error (RMSE = 0.130~0.287) and mean absolute error (MAE = 0.091~0.198). In addition, the spatial distribution of AOD was higher (>0.60) in most cities except the southeast of Nantong City (AOD 0.70) than in spring, autumn, and winter, whereas monthly AOD peaked in June (>0.9) and had a minimum in December (<0.4) for all the cities. Frequencies of 0.3 ≤ AOD < 0.4 and 0.4 ≤ AOD < 0.5 were relatively common, indicating a turbid atmosphere, which may be associated with anthropogenic activities, increased emissions, and changes in meteorological circumstances. Trend analysis showed significant increases in AOD during 2000–2009 for all the cities, perhaps reflecting a booming economy and industrial development, with significant emissions of sulfur dioxide (SO2), and primary aerosols. China’s strict air pollution control policies and control of vehicular emissions helped to decrease AOD from 2010 to 2019, enhancing air quality throughout the study area. A notably similar pattern was observed for AOD and meteorological parameters (LST: land surface temperature, WV: water vapor, and P: precipitation), signifying that meteorology plays a role in terms of increasing and decreasing AOD
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