Design and Analysis of Propellant Tanks Support Structure for an Advanced Spacecraft

This paper proposes a new type of configuration to support the propellant tanks in large size spacecrafts. Research in space industry over the last decade is focused on reducing the launch cost of the spacecraft. The main objective of this project work is to develop new concept of propellant tanks support structure for 6 ton class spacecraft. This configuration has four propellant tanks (2 oxygen tanks & 2 fuel tanks) which are mounted in polar form outside the central thrust cylinder and are supported by a flat rigid panel and two struts at fixed end and flat deck at free end. The stiffness requirements of advanced spacecraft are \u3e 8Hz, \u3e27Hz and \u3e30Hz for global lateral mode of the spacecraft, oxygen tanks axial mode and fuel tanks axial mode respectively. For support structure various configurations, were worked out to meet stiffness requirements. The configurations considered are Honeycomb Sandwich panel, Honeycomb Sandwich panel embedded with doublers at tank attachment zone, Honeycomb sandwich panel embedded with rectangle beam at tank attachment zone and Honeycomb sandwich panel with circular struts at tank attachment zone. Design iterations were carried out for above four configurations and suitable configuration was finalized. Static analysis was also carried out for the given load cases to determine strain, Hoffmann failure index, SR and MOS for the composite central thrust cylinder. The geometric modeling of the propellant tanks support structure and main parts of the advanced spacecraft for all the four configurations were modeled by using UNIGRAPHICS-Nx6® and analysis carried out using MSC/PATRAN®, MSC/NASTRAN®

Clinic epidemiological evaluation of co morbidities in patients with psoriasis in a tertiary care hospital

Background: Psoriasis is a common disease presented to the dermatology clinics. There are several reports concerning co morbidities in patients with psoriasis. Some of them include diabetes mellitus, hypertension, dyslipidemia, obesity, IHD, ulcerative colitis. Hence, we in the present study tried to evaluate the existing comorbidities in patients diagnosed with psoriasis in presenting to our hospital. Methods: This study was conducted in the Department of Dermatology, Venereology, and Leprosy, Prathima Institute of Medical Sciences, Karimnagar. This case-control study evaluated the prevalence of diabetes mellitus, hypertension, obesity, dyslipidemia and metabolic syndrome in patients with psoriasis. The existence of hypertension, diabetes mellitus, dyslipidemia, obesity was determined by standard criteria. The data was recorded and analyzed using SPSS version 17 for p values. Results: BSL (Blood Sugar Level) derangement as increased fasting BSL was observed in 23 (23%) cases compared to 8(8%) controls. There was a statistically significant difference between psoriatic cases and controls. The total number of male patients with raised waist circumference was 24 (33.8%) compared to 9(13.2%) controls. There was a statistically significant association of raised waist circumference in psoriasis cases compared to controls, the p-value was <0.004. The existence of metabolic syndrome was 27% in the study group and 8% in the control group the p values were <0.004 and significant. Conclusion: The results of the present shows that there is a significant prevalence of psoriasis in males as compared to females. There is a significant association of metabolic syndrome in patients with psoriasis. Hence all the patients with psoriasis need to be evaluated for metabolic syndrome which may be a risk factor for systemic disease

On Optimality of Long Document Classification using Deep Learning

Document classification is effective with elegant models of word numerical distributions. The word embeddings are one of the categories of numerical distributions of words from the WordNet. The modern machine learning algorithms yearn on classifying documents based on the categorical data. The context of interest on the categorical data is posed with weights and the sense and quality of the sentences is estimated for sensible classification of documents. The focus of the current work is on legal and criminal documents extracted from the popular news channels, particularly on classification of long length legal and criminal documents. Optimization is the essential instrument to bring the quality inputs to the document classification model. The existing models are studied and a feasible model for the efficient document classification is proposed. The experiments are carried out with meticulous filtering and extraction of legal and criminal records from the popular news web sites and preprocessed with WordNet and Text Processing contingencies for efficient inward for the learning framework

Design & Simulation of 11-level Cascaded H-bridge Grid-tied Inverter for the application of Solar Panels

This paper presents, the design and simulation of 11-level Cascaded H-bridge DC-AC Grid-tied Inverter for the application of solar panels. A 200w solar panel connected to each inverter bridge. OPALRT lab was used as the hardware in the loop (HIL) real-time control system platform where a Maximum Power Point Tracking (MPPT) algorithm was implemented based on the inverter output power to assure optimal operation of the inverter when connected to the power grid as well as a Phase Locked Loop (PLL) for phase and frequency match. A novel SPWM scheme is proposed in this paper to be used with the solar panels that can account for voltage profile fluctuations among the panels during the day. The experiment is clearly verified with simulation results

DC-DC Energy Conversion with Novel loaded Resonant Converter

This paper presents the direct current (dc)-to-dc energy conversion with novel loaded-resonant converter. Energy shortages and increasing oil prices have created the demand for a high energy conversion efficiency and performance. The growing electronic product market has increased the demand for high energy conversion efficiency and high power density of dc-to-dc energy power converters. The soft switching scheme is the most attractive dc-to-dc energy conversion topology in recent years. The soft-switching method can reduce switching losses and EMI of the switch-mode converter. Among the many advantages that resonant power conversion has over conventionally adopted pulse-width modulation include a low electromagnetic interference, low switching losses, small volume, and light weight of components due to a high switching frequency, high efficiency, and low reverse recovery losses in diodes owing to a low di/dt at switching instant. The proposed topology comprises a half-bridge inductor-capacitor inductor (L-C-L) resonant inverter and a bridge rectifier. Output stage of the proposed loaded-resonant converter is filtered by a low-pass filter. A prototype dc-to-dc energy converter circuit with the novel loaded-resonant converter designed for a load is developed and tested to verify its analytical predictions. The measured energy conversion efficiency of the proposed novel loaded-resonant topology reaches up to 88.3%. Moreover, test results demonstrate a satisfactory performance of the proposed topology. Furthermore, the proposed topology is highly promising for applications of switching power supplies, battery chargers, uninterruptible power systems, renewable energy generation systems, and telecom power supplies. The experimental results are clearly verified by simulation results

Sensorless Speed Control Scheme for Induction Motor Drive Using DC link Measurements

The controlled induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, the information on the rotor speed is extracted from measured stator voltages and currents at the motor terminals. Vector controlled drives requires estimating the magnitude and spatial orientation of the fundamental magnetic flux waves in the stator or in the rotor. Open loop estimators or closed loop observers are used for this purpose. They differ with respect to accuracy, robustness and sensitivity against model parameter variations. This paper presents a new control strategy for three-phase induction motor which includes independent speed &amp;torque control loops and the current regulation thereby overcoming the limitation (i.e. sluggish response) of volts per hertz controlled industrial drives. For closed-loop control, the feedback signals including the rotor speed, flux and torque are not measured directly but are estimated by means of an algorithm. The inputs to this algorithm are the reconstructed waveforms of stator currents and voltages obtained from the dc link and not measured directly on stator side. The proposed drive thus requires only one sensor in the dc link to implement the close-loop speed and torque control of a three-phase induction motor

Power Quality Improvement in Utility Grid using Single Phase Micro Sources, DSTATCOM and Distributed Generators

This paper proposes to improve the power quality in autility connected grid by using converter based singlephase micro sources. T he voltage unbalance can besevere if single-phase rooftop mounted PVs aredistributed randomly between the households.Moreover, there can also be single-phase nonlinearloads present in the system. The cumulative effect ofall these will cause power quality problem at theutility side. To counteract this problem, we haveproposed t wo different schemes. In this firstscheme a distribution static compensator (DSTATCOM) is connected at the utility bus toimprove the power quality. The DSTATCOM onlysupplies reactive power and no real power. In thesecond scheme, a larger three-phase convertercontrolled DG is placed that not only supplies thereactive power but also provides active power. Theefficacies of the  controllers have been validatedthrough simulation for  various operatingconditions using MATLAB/SIMULINK

Renewable Energy System with High performance Hybrid Cascaded Inverter

In this paper, Renewal energy system with high performance Hybrid cascaded inverter is proposed. It is based on two kinds of power devices those are MOSFET and IGBT and also the cascaded inverter consists of three H-bridges. The DC voltage of each H-bridge meets the proportional relationship of 1:2:4 and the three modules are connected in series at the AC side. The low voltage bridge is composed of MOSFETs, while the medium and high voltage bridges are composed of IGBTs. This hybrid cascaded inverter can output at most 15 voltage levels at the AC side with rather low switching frequency. At the same time, it can fully exhibit the advantages of different power devices and make the inverter operation flexible. Voltage gradational and PWM carrier modulation methods are adopted in this paper. With different combination of switching states, the distribution of input active power in each H-bridge can be adjusted. As a result, for renewable energy system, larger control freedom is provided and the need of power balance is satisfied. The inverter system is verified with simulation results

Structural Properties of Co2+ Ion Doped Calcium Cadmium Phosphate Hydrate Nanophosphor

Inorganic nanophosphor materials have captivated the worldwide attention into the field of solid-state lighting emission displays, plasma display panels, light-emitting diodes, IR quantum counters, scintillation, etc. Nanotechnology is the foremost superior in the development of phosphors with definite size and shape. Alkali and alkaline earth phosphates are promising candidates for the inorganic phosphor materials. Manufacturing of nano-inorganic materials gained much interest due to their advance lighting applications. In this work, novel Co2+ doped Calcium Cadmium Phosphate hydrate nanophosphor (CaCdPH: Co2+) was synthesized by a traditional solid-state reaction technique. The synthesized sample was characterized by Powder XRD, SEM equipped with EDX and FTIR techniques. The hexagonal phase of the prepared CaCdPH: Co2+sample was confirmed by X-ray diffraction results, and the average crystallite size was evaluated. FTIR demonstrated the formation of vibrational modes ascribed to phosphate molecules and other hydroxyl groups. The morphologies of the CaCdPH: Co2+ nanophosphor was investigated by scanning electron microscopy. © 2020 Author(s).One of the authors, T. Rajyalakshmi is thankful to JNTU Kakinada, DIC for financial assistance in the MHRD project. Authors express their special thanks to UGC-DRS, DST-FIST - New Delhi for providing financial assistance to the Dept. of Physics, Acharya Nagarjuna University. And also acknowledge the service render by scientific officers of Kerala University and Yogi Vemana University for their help providing XRD and SEM instruments for sample recordings

Diagnostic Accuracy of Integrating Ultrasound and Shear Wave Elastography in Assessing Carpal Tunnel Syndrome Severity: a Prospective Observational Study

Ahmed Mohamed El-Maghraby,1 Yassir Edrees Almalki,2 Mohammad Abd Alkhalik Basha,1 Mohamad Gamal Nada,1 Fatma El Ahwany,1 Sharifa Khalid Alduraibi,3 Shaker Hassan S Alshehri,4 Asim S Aldhilan,3 Ziyad A Almushayti,3 Alaa K Alduraibi,3 Mervat Aboualkheir,5 Osama Attia,6 Mona M Amer,7 Ahmed M Abdelkhalik Basha,8 Ibrahim M Eladl1 1Department of Diagnostic Radiology, Faculty of Human Medicine, Zagazig University, Zagazig, 44519, Egypt; 2Division of Radiology, Department of Internal Medicine, Medical College, Najran University, Najran, 61441, Kingdom of Saudi Arabia; 3Department of Radiology, College of Medicine, Qassim University, Buraidah, 52571, Kingdom of Saudi Arabia; 4Department of Orthopedic Surgery, College of Medicine, King Khalid University, Abha, 61421, Kingdom of Saudi Arabia; 5Department of Internal Medicine, College of Medicine, Taibah University, Madinah, 42361 Kingdom of Saudi Arabia; 6Department of Internal Medicine, Faculty of Human Medicine, Zagazig University, Zagazig, 44519, Egypt; 7Department of Neurology, Faculty of Human Medicine, Zagazig University, Zagazig, 44519, Egypt; 8Faculty of General Medicine, Saint Petersburg State University, Egypt Branch, Cairo, 11646, EgyptCorrespondence: Yassir Edrees Almalki, Email [email protected]: Carpal tunnel syndrome (CTS) is a common condition characterized by compression of the median nerve (MN) within the carpal tunnel. Accurate diagnosis and assessment of CTS severity are crucial for appropriate management decisions. This study aimed to investigate the combined diagnostic utility of B-mode ultrasound (US) and shear wave elastography (SWE) for assessing the severity of CTS in comparison to electrodiagnostic tests (EDT).Materials and Methods: This prospective observational study was conducted over 9-month periods at a tertiary care hospital. A total of 48 patients (36 females, 12 males; mean age 44 ± 10.9 years; age range 28– 57 years) with clinically suspected CTS were enrolled. All patients underwent EDT, US, and SWE. Based on the EDT results, CTS cases were categorized into four groups: mild, moderate, severe, and negative. The cross-sectional area (CSA) and elasticity (E) of the MN were measured at the tunnel inlet (CSAu and Eu) and pronator quadratus region (CSAo and Eo). The differences (CSAu-CSAo and Eu-Eo) were calculated. The primary outcomes were the diagnostic performance of CSAu, CSAu-CSAo, Eu, and Eu-Eo in differentiating moderate/severe from mild/negative CTS compared to EDT findings. Secondary outcomes included a correlation of US/SWE parameters with EDT grades and between each other. ANOVA, correlation, regression, and receiver operating characteristic (ROC) curve analyses were performed.Results: CSAu and CSAu–CSAo increased progressively with worsening CTS severity. E measurements were significantly higher in moderate-to-severe CTS compared to mild or negative cases. The combined metric of CSAu-CSAo at a 5 mm threshold exhibited enhanced performance, with a higher sensitivity (83.3%), specificity (100%), and area under the curve (AUC) (0.98), surpassing the results of CSAu when used independently. Similarly, the SWE measurements indicated that Eu-Eo at a 56.1kPa cutoff achieved an AUC of 0.95, with a sensitivity of 93.3% and specificity of 94.4%, outperforming the metrics for Eu when used alone, which had an AUC of 0.93, with identical sensitivity and specificity values (93.3% and 94.4%, respectively).Conclusion: The integration of ultrasound, shear wave elastography, and electrodiagnostic tests provides a comprehensive approach to evaluate anatomical and neurological changes and guide management decisions for CTS.Keywords: carpal tunnel syndrome, median never, ultrasound, shear wave elastograph