The Electric Power System (EPS) and attitude control system (ACS) are the essential components of any satellite. EPS and ACS efficiency and compactness are substantial for the proper operation and performance of the satellite’s entire mission life. So, realizing the significance of EPS and ACS subsystems for any satellite, they have been assimilated and developed in modular forms focusing on efficiency and compactness. The EPS is comprised of three modules called the solar panel module (SPM), power conditioning module (PCM), and power distribution module (PDM) while the ACS has an embedded magnetorquer coil. For compactness and miniaturization purposes, the magnetorquer coil is embedded inside the SPM. The components used are commercial off-the-shelf (COTS) components emphasizing on their power efficiency, small dimensions, and weight. Latch-up protection systems have been designed and analyzed for CMOS-based COTS components, in order to make them suitable for space radioactive environment. The main design features are modularity, redundancy, power efficiency, and to avoid single component failure. The modular development of the EPS and ACS helps to reuse them for future missions, and as a result, the overall budget, development, and testing time and cost are reduced. A specific satellite mission can be achieved by reassembling the required subsystems.
Although short tandem repeat (STR) analysis is available as a reliable method for the determination of the genetic origin of cell lines, the occurrence of misauthenticated cell lines remains an important issue. Reasons include the cost, effort and time associated with STR analysis. Moreover, there are currently no methods for the discrimination between isogenic cell lines (cell lines of the same genetic origin, e.g. different cell lines derived from the same organism, clonal sublines, sublines adapted to grow under certain conditions). Hence, additional complementary, ideally low-cost and low-effort methods are required that enable (1) the monitoring of cell line identity as part of the daily laboratory routine and 2) the authentication of isogenic cell lines. In this research, we automate the process of cell line identification by image-based analysis using deep convolutional neural networks. Two different convolutional neural networks models (MobileNet and InceptionResNet V2) were trained to automatically identify four parental cancer cell line (COLO 704, EFO-21, EFO-27 and UKF-NB-3) and their sublines adapted to the anti-cancer drugs cisplatin (COLO-704rCDDP1000, EFO-21rCDDP2000, EFO-27rCDDP2000) or oxaliplatin (UKF-NB-3rOXALI2000), hence resulting in an eight-class problem. Our best performing model, InceptionResNet V2, achieved an average of 0.91 F1-score on tenfold cross validation with an average area under the curve (AUC) of 0.95, for the 8-class problem. Our best model also achieved an average F1-score of 0.94 and 0.96 on the authentication through a classification process of the four parental cell lines and the respective drug-adapted cells, respectively, on a four-class problem separately. These findings provide the basis for further development of the application of deep learning for the automation of cell line authentication into a readily available easy-to-use methodology that enables routine monitoring of the identity of cell lines including isogenic cell lines. It should be noted that, this is just a proof of principal that, images can also be used as a method for authentication of cancer cell lines and not a replacement for the STR method.
This paper discusses designing and implementation of an efficient Electric Power Supply System (EPS) for a Micro Satellite. Design and analysis of satellite different subsystems such as power generation, distribution and management, power storage, modules protection, bus voltage regulation and battery charging for micro-satellite have been discussed in detail. To perform all these duties whole EPS is divided into three units i.e. Solar Power Unit, Power Conditioning Unit and Power Distribution Unit. Each unit is an isolated system, has a local controller and standard inputs/outputs, connected with the Satellite main computer through standard buses (CAN buses) and can be attached/detached from the Satellite as separate unit. All the subsystems are based on Commercial off the Shelf (COTS) Components which were selected on the bases of small dimensions, low power consumption and lesser weight. Different techniques have been utilized for overall system size miniaturization and efficiency improvement i.e. the design solar panel converter is MPPT based. The main design criteria is modularity, redundancy, power efficient and scalability, simple as possible, avoid single component failure and maximum utilization of the existing heritage.
In next-generation mobile radio systems, multiple access schemes will support a massive number of uncoordinated devices exhibiting sporadic traffic, transmitting short packets to a base station. Grant-free non-orthogonal multiple access (NOMA) has been introduced to provide services to a large number of devices and to reduce the communication overhead in massive machine-type communication (mMTC) scenarios. In grant-free communication, there is no coordination between the device and base station (BS) before the data transmission; therefore, the challenging task of active users detection (AUD) must be carried out at the BS. For NOMA with sparse spreading, we propose a deep neural network (DNN)-based approach for AUD called active users enumeration and identification (AUEI). It consists of two phases: firstly, a DNN is used to estimate the number of active users; then in the second phase, another DNN identifies them. To speed up the training process of the DNNs, we propose a multi-stage transfer learning technique. Our numerical results show a remarkable performance improvement of AUEI in comparison to previously proposed approaches.INDEX TERMS Active user detection, deep neural network, grant-free, massive machine-type communication, non-orthogonal multiple access, transfer learning.
Objective: To determine the etiological pattern, clinical presentation and outcome of patients with proptosis in a tertiary care hospital. Study Design: Cross-sectional study. Place and Duration of Study: Ophthalmology Department, Khyber Teaching Hospital, Peshawar Pakistan, from Jan 2019 to Jun 2020. Methodology: This study was conducted on 60 patients having proptosis. Patients were treated either medically, surgically or both. The demographic profile included age, gender and type of proptosis. The outcome included recovery, re-treatment,referral to the relevant speciality and loss to follow-up, were measured. Results: Out of 60 patients with proptosis, 39 were males, and 21 were female. Fifty-two patients had unilateral, and 8 had bilateral proptosis, with the majority suffering from non-axial proptosis. On aetiology exhibited tumours (45%), infectious (25%), inflammatory (16.6%), vascular (6.66%) and injury (6.66%). The surgical procedure was indicated in 27(45%) patients,while medical treatment was given in 28(46.6%) patients. Five patients (8.4%) received both surgical and medical treatment. Out of 60 patients, 26 patients (46.33%) fully recovered and 11 patients (18.33%) did not recover, 17(28.33%) patients were referred to other specialities for management, and 5(8.3%) patients lost to follow-up. Conclusion: In our study, tumours were the main cause of proptosis, followed by infective and inflammatory causes, with the paediatric age group (<18 years) at more risk.
In this paper, a stand-alone photovoltaic (PV) system based on a Double Ended Forward Converter (DEFC) is presented. The proposed converter is specified for 48 V, 100 W applications as most of the equipment used in telecommunication and aircraft fall in this range. The literature has limited potential application of DEFC in PV systems. The research work deals with an in-depth study of DEFC and proposes an improved DEFC for PV applications with battery backup. Besides, a bi-directional dc-dc converter for the battery is integrated to track the Maximum Power Point (MPP) of the PV generator. The converter is examined under variable irradiance and load conditions, and the analytical analysis of boundary conditions are implemented. The converter's architecture also ensures built-in I-V curve tracing for the identification of MPP of PV generator. It offers low voltage stresses across switches and avoids sinking power supply and core resetting circuits. The topology's behavior is analyzed based on MPP achievement and maintaining output under different conditions of battery backup availability, environmental, and load conditions. The PV system architecture is designed and analyzed theoretically and verified with simulations on the PSIM software.
Grape pomace is a rich source of bioactive compounds and dietary fiber. This study aims to valorize the grape pomace by microwave-vacuum-assisted drying and extraction, which is a novel, green, and clean label technology. The drying and extraction of bioactive compounds from the grape pomace was optimized using response surface methodology. Box-Behnken design was used for three process variables, i.e., time, power, and vacuum levels. The highest drying rate was observed (5.53 g/100 g min after 10 min of drying) at the combination of 80 W and 20 inHg. This combination significantly reduced the drying time (25%) and resulted in the highest yield (64.5%) of bioactive compounds. Equally, changes in moisture ratio behavior were rapid under these processing conditions. Furthermore, Midilli model (R2 = 0.999, RMSE = 0.002, SSE = 3.71 × 10−6) was the best to justify the fitness of experimental values with predicted values. In addition, the diffusion coefficient, activation energy, and extraction yield were increased with increase in power and pressure. The concentration of bioactive components was higher in dried pomace compared to the extract. The extraction was successfully achieved without the use of solvent and the characteristics of extracted phenolics remained unaltered. Based on these findings, the microwave-vacuum-assisted drying and extraction process can be claimed as a sustainable approach.
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