Health management design considerations for an all electric aircraft

This paper explains the On-board IVHM system for a State-Of-the-Art “All electric aircraft” and explores implementing practices for analysis based design, illustrations and development of IVHM capabilities. On implementing the system as an on board system will carry out fault detection and isolation, recommend maintenance action, provides prognostic capabilities to highest possible problems before these became critical. The vehicle Condition Based Maintenance (CBM) and adaptive control algorithm development based on an open architecture system which allow “Plug in and Plug off” various systems in a more efficient and flexible way. The scope of the IVHM design included consideration of data collection and communication from the continuous monitoring of aircraft systems, observation of current system states, and processing of this data to support proper maintenance and repair actions. Legacy commercial platforms and HM applications for various subsystems of these aircraft were identified. The list of possible applications was down-selected to a reduced number that offer the highest value using a QFD matrix based on the cost benefit analysis. Requirements, designs and system architectures were developed for these applications. The application areas considered included engine, tires and brakes, pneumatics and air conditioning, generator, and structures. IVHM design program included identification of application sensors, functions and interfaces; IVHM system architecture, descriptions of certification requirements and approaches; the results of a cost/benefit analyses and recommended standards and technology gaps. The work concluded with observations on nature of HM, the technologies, and the approaches and challenges to its integration into the current avionics, support system and business infrastructure. The IVHM design for All Electric Hybrid Wing Body (HWB) Aircraft has a challenging task of addressing and resolving the shortfalls in the legacy IVHM framework. The challenges like sensor battery maintenance, handling big data from SHM, On-Ground Data transfer by light, Extraction of required features at sensor nodes/RDCUs, ECAM/EICAS Interfaces, issues of certification of wireless SHM network has been addressed in this paper. Automatic Deployable Flight Data recorders are used in the design of HWB aircraft in which critical flight parameters are recorded. The component selection of IVHM system including software and hardware have been based on the COTS technology. The design emphasis on high levels of reliability and maintainability. The above systems are employed using IMA and integrated on AFDX data bus. The design activities has to pass through design reviews on systematic basis and the overall approach has been to make system highly lighter, effective “All weather” compatible and modular. It is concluded from the study of advancement in IVHM capabilities and new service offerings that IVHM technology is emerging as well as challenging. With the inclusion of adaptive control, vehicle condition based maintenance and pilot fatigue monitoring, IVHM evolved as a more proactively involved on-board system

Composition and Structure Based GGA Bandgap Prediction Using Machine Learning Approach

This study focuses on developing precise machine learning (ML) regression models for predicting energy bandgap values based on chemical compositions and crystal structures. The primary aim is to match the accuracy of predictions derived from GGA-PBE calculations and validate them through density functional theory (DFT)-based band structure calculations. We assessed eight standalone ML regression models, including AdaBoost, Bagging, CatBoost, LGBM, RF, DT, GB, and XGB. These models were analyzed for their ability to predict GGA-PBE bandgap values across diverse material structures and compositions, using a dataset containing bandgap values for 106,113 compounds. Additionally, we constructed four ensemble models using the stacking method and seven using the bagging method. These ensemble models incorporated RidgeCV and LassoCV to explore if ensemble techniques could enhance prediction accuracy. The dataset was divided into subsets of varying sizes: 10,000, 25,000, 50,000, and 100,000 entries. We determined feature importance through permutation techniques and established a correlation coefficient matrix using the Pearson correlation method. The Random Forest (RF) model emerged as the top performer among standalone models, achieving an R2 value of 0.943 and an RMSE value of 0.504 eV. Bagging regression demonstrated improved performance across different dataset sizes with streamlined feature selection. Ensemble models, particularly bagging, consistently outperformed standalone models, achieving the best R2 value of 0.948 and an RMSE value of 0.479 eV in the test dataset. Using the best-performing model, we predicted bandgap values for new half-Heusler compounds with 18 valence electron counts. These predictions were successfully validated using accurate DFT calculations. DFT calculations indicated that the newly predicted compounds are narrow bandgap semiconductors with dynamic stability.Comment: 17 pages, 17 figures, Research pape

Tunneling Study of the Charge-Ordering Gap on the Surface of La0.350_{0.350}Pr0.275_{0.275}Ca0.375_{0.375}MnO3_3 Thin Films

Variable temperature scanning tunneling microscopy/spectroscopy studies on (110) oriented epitaxial thin films of La$_{0.350}$Pr$_{0.275}$Ca$_{0.375}$MnO$_3$ are reported in the temperature range of 77 to 340 K. The films, grown on lattice matched NdGaO$_3$ substrates, show a hysteretic metal-insulator transition in resistivity at 170 K. The topographic STM images show step-terrace morphology while the conductance images display a nearly homogeneous surface. The normalized conductance spectra at low temperatures (T$<$150 K) show an energy gap of 0.5 eV while for T$\geq$180 K a gap of 0.16 eV is found from the activated behavior of the zero bias conductance. The presence of energy gap and the absence of phase separation on the surface over more than 2 $\mu$m$\times$2 $\mu$m area contradicts the metallic behavior seen in resistivity measurements at low temperatures. We discuss the measured energy gap in terms of the stabilization of the insulating CO phase at the film surface.Comment: 5 pages, 5 figures To appear in Phys. Rev.

A study on the response of Indian dip and low latitude ionospheric regions to a limb centred X9.0 class solar flare

In this paper, we present how Indian dip equatorial and low latitude ionospheric system responded to a limb centred X9.0 class of solar flare event using GPS-TEC, Ionosonde and magnetometer measurements. The limb centred X9.0 solar flare was materialise on 05 December 2006 at the heliography coordinate S07E68 and NOAA 10930 active region, started at 10:18 UT (15:48 IST), peaked at 10:35 UT (16:05 IST), and decayed by 10:45 UT (16:15 IST). The measurements of the total electron content (TEC) of 30 s time resolutions from a series of GPS receivers installed near the dip and low latitude regions does not show TEC enhancement during peak flare hours, 10:35 UT (16:05 IST). An appreciable enhancement in the TEC units (∼5 TEC units) is noticeable during post flare hours, 13:00 UT (18:30 IST) which is high at dip equatorial compare to low latitude regions. The Ionosonde measurement of 15 min time resolution at dip equatorial station shows an increase in the plasma density at the F-region while the E-region did not show any impact during peak flare hours, 10:35 UT (16:05 IST). The analysis of horizontal component of geomagnetic field (H) of 1 min time resolution data obtained from the INTERMAGNET shows sudden rise in electron density in the E-region of the ionosphere and intensification in the ionospheric current system in eastward direction at the dip equatorial and reverse in direction at low latitude regions at 10:35 UT (16:05 IST). Present analyses contribute our understanding about plasma dynamics during flare and post flare hours in the E and F-regions of Indian dip and low latitude Ionosphere

Accelerating Discovery of Vacancy Ordered 18-Valence Electron Half-Heusler Compounds: A Synergistic Approach of Machine Learning and Density Functional Theory

In this study, we attempted to model vacancy ordered half Heusler compounds with 18 valence electron count (VHH) derived from 19 VEC compounds such as TiNiSb such that the compositions will be Ti0.75NiSb, Zr0.75NiSb and Hf0.75NiSb with semiconducting behavior. The main motivation is that such a vacancy-ordered phase not only introduces semi conductivity but also it disrupts the phonon conducting path in HH alloys and thus reduces the thermal conductivity and as a consequence enhances the thermoelectric figure of merit. In order to predict the formation energy ({\Delta}Hf) from composition and crystal structure we have used 4684 compounds for their {\Delta}Hf values are available in the material project database and trained a machine learning model with R2 value of 0.943. Using this trained model, we have predicted the {\Delta}Hf of a list of VHH. From the predicted database of VHH we have selected Zr0.75NiSb and Hf0.75NiSb to validate the machine learning prediction using accurate DFT calculation. The calculated {\Delta}Hf for these two compounds from DFT calculation are found to be comparable with our ML prediction. The calculated electronic and lattice dynamics properties show that these materials are narrow band gap semiconductors and are dynamically stable as their all-phonon dispersion curves are having positive frequencies. The calculated Seebeck coefficient, electrical conductivity as well as thermal conductivity, power factor and thermoelectric figure of merit are analyzed.Comment: 5 pages, 2 figures, conferenc

Gluon distributions in the proton in a light-front spectator model

We formulate a light-front spectator model for the proton incorporating the gluonic degree of freedom. In this model, at high energy scattering of the proton, the active parton is a gluon and the rest is viewed as a spin-$\frac{1}{2}$ spectator with an effective mass. The light front wave functions of the proton are constructed using a soft wall AdS/QCD prediction and parameterized by fitting the unpolarized gluon distribution function to the NNPDF3.0nlo data set. We investigate the helicity distribution of gluon in this model. We find that our prediction for the gluon helicity asymmetry agrees well with existing experimental data and satisfies the perturbative QCD constraints at small and large longitudinal momentum regions. We also present the transverse momentum dependent distributions (TMDs) for gluon in this model. We further show that the model-independent Mulders-Rodrigues inequalities are obeyed by the TMDs computed in our model.Comment: 14 pages, 7 figure

SCOPUS citation analysis of publications from Saudi dental colleges

Purpose: Citation analysis is frequently employed to assess the research output of individuals, departments, and institutions. Intra-country institutional analysis of bibliometric analysis is needed to formulate appropriate research policies. To assess the research output of dental colleges in Saudi Arabia Research design: An observational study was conducted for publications from Dental Colleges in Saudi Arabia using the SCOPUS database. The data for the years 2016-18 were retrieved for 18 dental colleges of the Kingdom of Saudi Arabia (KSA). Key findings: The highest publication productivity was reported for King Abdulaziz University- Faculty of Dentistry (Jeddah). The highest number of publications in the years 2016-18 was from Jazan University- Faculty of Dentistry. The highest h index for 2016-18 was 8 for Imam Abdulrahman Bin Faisal University- College of Dentistry. The journal in which the most articles were published was the Journal of Contemporary Dental Practice. Conclusions/Implications: Jazan University- Faculty of Dentistry, King Abdulaziz University- Faculty of Dentistry (Jeddah) and Imam Abdulrahman Bin Faisal University- College of Dentistry are the leading dental institutions in the KSA regarding the number of papers published, the number of citations and the h index. The increased focus on research in institutions in Saudi Arabia is evidenced by the steady rise in their number of publications

SCOPUS citation analysis of publications from Saudi dental colleges

Purpose: Citation analysis is frequently employed to assess the research output of individuals, departments, and institutions. Intra-country institutional analysis of bibliometric analysis is needed to formulate appropriate research policies. To assess the research output of dental colleges in Saudi Arabia Research design: An observational study was conducted for publications from Dental Colleges in Saudi Arabia using the SCOPUS database. The data for the years 2016-18 were retrieved for 18 dental colleges of the Kingdom of Saudi Arabia (KSA). Key findings: The highest publication productivity was reported for King Abdulaziz University- Faculty of Dentistry (Jeddah). The highest number of publications in the years 2016-18 was from Jazan University- Faculty of Dentistry. The highest h index for 2016-18 was 8 for Imam Abdulrahman Bin Faisal University- College of Dentistry. The journal in which the most articles were published was the Journal of Contemporary Dental Practice. Conclusions/Implications: Jazan University- Faculty of Dentistry, King Abdulaziz University- Faculty of Dentistry (Jeddah) and Imam Abdulrahman Bin Faisal University- College of Dentistry are the leading dental institutions in the KSA regarding the number of papers published, the number of citations and the h index. The increased focus on research in institutions in Saudi Arabia is evidenced by the steady rise in their number of publications

Tick Salivary Gland Extract Induces Alpha-Gal Syndrome In Alpha-Gal Deficient Mice

Introduction: Alpha-gal syndrome (AGS) is characterized by delayed hypersensitivity to non-primate mammalian meat in people having specific immunoglobulin E (sIgE) to the oligosaccharide galactose-alpha-1,3-galactose. AGS has been linked to tick bites from Amblyomma americanum (Aa) in the U.S. A small animal model of meat allergy is needed to study the mechanism of alpha-gal sensitization, the effector phase leading to delayed allergic responses and potential therapeutics to treat AGS. Methods: Eight- to ten-weeks old mice with a targeted inactivation of alpha-1,3-galactosyltransferase (AGKO) were injected intradermally with 50 μg of Aa tick salivary gland extract (TSGE) on days 0, 7, 21, 28, 42, and 49. Total IgE and alpha-gal sIgE were quantitated on Day 56 by enzyme-linked immunosorbent assay. Mice were challenged orally with 400 mg of cooked pork kidney homogenate or pork fat. Reaction severity was assessed by measuring a drop in core body temperature and scoring allergic signs. Results: Compared to control animals, mice treated with TSGE had 190-fold higher total IgE on Day 56 (0.60 ± 0.12 ng/ml vs. 113.2 ± 24.77 ng/ml; p \u3c 0.001). Alpha-gal sIgE was also produced in AGKO mice following TSGE sensitization (undetected vs. 158.4 ± 72.43 pg/ml). Further, sensitized mice displayed moderate clinical allergic signs along with a drop in core body temperature of ≥2°C as an objective measure of a systemic allergic reaction. Interestingly, female mice had higher total IgE responses to TSGE treatment but male mice had larger declines in mean body temperature. Conclusion: TSGE-sensitized AGKO mice generate sIgE to alpha-gal and demonstrate characteristic allergic responses to pork fat and pork kidney. In keeping with the AGS responses documented in humans, mice reacted more rapidly to organ meat than to high fat pork challenge. This mouse model establishes the central role of tick bites in the development of AGS and provides a small animal model to mechanistically study mammalian meat allergy

A clinical study of foreign bodies in air passages

Background: Foreign body in the airways is a serious event and fatal if not managed properly in time. Accident resulting from the inhalation of the foreign body continues to take formidable toll of lives every year.Objecti ve: This study was undertaken to find out the incidence of foreign bodies in air passages in this part of the country and types of foreign bodies, to establish the role of radiological investigations, and to find out the effective measures which are valuable in decreasing the post endoscopic complications and morbidity. Methods: This retrospective study was conducted in all suspected cases of foreign body in the air passages attending as well as referred to the Department of Otolaryngology of a Medical College of Rajasthan from January 2014 to December 2015. In each case, a procedure like direct laryngoscopy or bronchoscopy was done depending on the site of the foreign body. Results: Out of 100 cases, 58 were males and 42 were females. 88% of the patients were children below the age of 12 years. The most common foreign body extracted was betel nut in 47% of the cases. Commonest sign observed was decreased air entry in the lung (83%). Commonest radiological finding was obstructive collapse (37%). 48% of the total foreign bodies were present in right bronchus while 32% were lodged in the left bronchus and 3% at the carina. Conclusion: A diagnostic bronchoscopy should always be done in refractory cases of chronic respiratory infection, allergy or pneumonia. A negative radiological examination does not exclude a foreign body