Spectral Analysis Research Articles

Chemical assessment of three octahedral Ni(II) complexes with heterocyclic acylpyrazolone ligand: Crystal structure, DFT-NBO analysis, Hirshfeld and Magnetic study

We have synthesized three novel mononuclear Nickel(II) coordination complexes [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] and [Ni(PCBPTMP)2(DMSO)2] with σ-donating acylpyarazolone ligands. All the complexes have been comprehensively characterized via FTIR, UV–Vis, TGA, and Magnetic study. Additionally, single crystal X-ray diffraction analysis was successfully used to characterize the three complexes. The findings showed that the geometry around Ni(II) is slightly distorted octahedral in [Ni(DMBPTMP)2(EtOH)2], [Ni(PCBPMP)2(DMF)(H2O)] complexes and also in the centrosymmetric [Ni(PCBPTMP)2(DMSO)2] complex. In all the complexes the metal is bischelated by two pyrazolone molecules via carbonyl and benzoyl carbonyl oxygen donors, but with a different configuration of ligands. In addition to the experimental studies and spectroscopic characteristics, DFT computational analysis and Natural bonding orbital (NBO) analysis have been performed using a B3LYP/LANL2DZ basis set for the optimization. All three Ni(II) complexes give three distinct absorption transitions which has been proved by Electronic spectral analysis. A paramagnetic nature of the complex is confirmed through magnetic study. Utilising Hirshfeld surface analysis, intermolecular interactions of complexes were evaluated.

Characterization of bearing health in a noisy environment using vibroacoustic approach

The bearing fault detection localized at outer race on a rotating machine operating in the same environment with another machine (whose wind tunnel generates a different noise) is investigated using acoustic and vibration analysis. The impact of increased acoustic and vibratory background noise on outer race defect detection is studied through spectral kurtogram representation and envelope analysis. The spectral power densities of these two types of noise clearly show that the nature of their associated radiation (airborne or solid-borne) has a different impact. The presence of a strongly amplified background noise demonstrates that the acoustic modality can detect the outer race defect peak at higher levels than the vibratory modality.

Compact staring-type underwater spectral imaging system utilizing k-Nearest neighbor-based interpolation for spectral reconstruction

Besides the challenges posed by the complex optical properties of water, underwater spectral imaging face significant issues, including system bulkiness, optical complexity, and high spectral resolution requirement. This study introduces a compact staring-type underwater spectral imaging system designed to overcome these limitations. Featuring a 6-channel rotary spectral camera, the system is optimized for optical simplicity, and spectral efficiency. It employs a k-Nearest Neighbor (KNN)-based spectral reconstruction method to substantially enhance spectral resolution. Auto-focusing and image registration techniques, utilizing the Tenengrad function and Scale-Invariant Feature Transform (SIFT) feature points, ensure sharp and aligned multi-channel imagery. Experimental validation demonstrates the system’s capability to accurately reconstruct spectral reflectance data across the 400 nm to 700 nm band, significantly increasing spectral resolution from 6 to 31 channels. The spectral reflectance reconstruction results, achieving an average Root Mean Square Error (RMSE) of 0.0651 and Goodness of Fit Coefficient (GFC) of 0.9871, highlight the system’s efficiency in precise spectral analysis. This advancement in spectral resolution and adaptability to diverse underwater applications marks a significant leap forward in underwater observation and monitoring through spectral imaging.

Sound quality characteristics of reciprocating hermetic refrigeration compressors

In recent years, sound quality (SQ) has become an increasingly important factor in the home appliance industry, enhancing the customer experience and comfort. Manufacturers that prioritize SQ in their designs can gain a competitive advantage in the market and increase customer satisfaction. The compressor is one of the main sources of noise in a refrigerator. While manufacturers typically provide refrigerator sound quality and noise labels, research that specifically evaluates the compressor sound quality metrics at a component level is not common. Therefore, this study aims to isolate the compressor from the refrigerator to investigate SQ metrics for hermetic refrigeration compressors. To achieve this, compressors with different capacities are operated and recorded at different working speeds for different thermal conditions. Objective parameters are calculated and tested using time domain signals and analyzed with spectral analysis methods. In addition to the objective parameters, subjective results are obtained through jury tests consisting of 75 people of different genders and age ranges. By considering objective parameters of sound quality as input and sound quality evaluation values as output, a regression model is established. It is found that Loudness, Sharpness, and Degree of Modulation play an important role in compressor sound quality evaluations consider.

APiS (AI powered intelligence spectrum analyser): hyperspectral imaging machine learning analyser app for mineral processing

ABSTRACT Hyperspectral data, encompassing hundreds of spectral wavelengths, is a powerful tool for mineral processing, as minerals display unique reflection spectra. Machine learning can identify mineral species from hyperspectral data, but its high dimensionality poses challenges for ordinary users. To address this, we developed APiS (AI Powered intelligence Spectrum Analyser), an interactive hyperspectral analysis application requiring no coding. APiS offers a user-friendly interface for data visualisation, learning data generation, advanced machine learning analysis, and model evaluation. This App surpasses previous script-based methods, enabling diverse users in geometallurgy to conduct sophisticated hyperspectral data analysis and fostering creativity in their work.

Unveiling the origin of XMM-Newton soft proton flares. I. Design and validation of a response matrix for proton spectral analysis

Low-energy ($<$ 300 keV) protons entering the field of view of XMM-Newton can scatter with the X-ray mirror surface and reach the focal plane. They are observed in the form of a sudden increase in the background level, the so-called soft proton flares, affecting up to 40<!PCT!> of the mission observing time. Soft protons can hardly be disentangled from true X-ray events and cannot be rejected on board. All future high throughput grazing incidence X-ray telescopes operating outside the radiation belts are potentially affected by soft proton-induced contamination that must be foreseen and limited since the design phase. In-flight XMM-Newton 's observations of soft protons represent a unique laboratory to validate and improve our understanding of their interaction with the mirror, optical filters, and X-ray instruments. At the same time, such models would link the observed background flares to the primary proton population encountered by the telescope, converting XMM-Newton into a monitor for soft protons. We built a Geant4 simulation of XMM-Newton including a verified mass model of the X-ray mirror, the focal plane assembly, and the EPIC MOS and pn-CCDs. Analytical computations and, when available, laboratory measurements collected from literature were used to verify the correct modelling of the proton scattering and transmission to the detection plane. Similarly to the instrument X-ray response, we encoded the energy redistribution and proton transmission efficiency into a redistribution matrix file (RMF), mapping the probability that a proton from 2 to 300 keV is detected in a certain detector channel, and an auxiliary response file (ARF), storing the grasp towards protons. Both files were formatted according to the standard NASA calibration database and any compliant X-ray data analysis tool can be used to simulate or analyse soft proton-induced background spectra. An overall systematic uncertainty of 30<!PCT!> was assumed on the basis of the estimated accuracy of the mirror geometry and transmission models. For the validation, three averaged soft proton spectra, one for each filter configuration, were extracted from a collection of 13 years of MOS observations of the focused non X-ray background and analysed with Xspec . A similar power-law distribution is found for the three filter configurations, plus black-body-like emission below tens of keV used as a correction factor, based on the dedicated spectral analysis of 55 in-flight proton flares presented in Paper II. The best-fit model is in agreement with the power-law distribution predicted from independent measurements for the XMM-Newton orbit, spent mostly in the magnetosheath and nearby regions. For the first time we are able to link detected soft proton flares with the proton radiation environment in the Earth's magnetosphere, while proving the validity of the simulation chain in predicting the background of future missions. Benefiting from this work and contributions from the Athena instrument consortia, we also present the response files for the Athena mission and updated estimates for its focused charged background.

FTIR, 1H-/13C-NMR spectral characterization, antimicrobial, anticancer, antioxidant, anti-inflammatory, PASS, SAR, and in silico properties of methyl α-D-glucopyranoside derivatives

A novel series of biologically active derivatives based on methyl α-D-glucopyranoside (MGP) has been developed, comprising 6-O-monosubstituted MGP derivatives obtained from methyl α-D-glucopyranoside. These derivatives were transformed into 2,3,4-tri-O-acyl MGP derivatives, incorporating diverse functionalities within a single molecular framework, aimed at producing new products for antimicrobial studies. All synthesized compounds were identified through spectral analyses (FTIR, 1H-NMR, and 13C-NMR) and elemental analysis. Antimicrobial in vitro testing revealed that these MGP derivatives have notable efficacy against various pathogenic microorganisms, along with the prediction of activity spectra for substances (PASS). Compounds 2 and 7 exhibited the highest inhibitory activity against Bacillus subtilis and Escherichia coli, with minimum inhibitory concentration (MIC) values ranging from 0.25 to 64.0 µg/mL and minimum bactericidal concentration (MBC) values ranging from 8.0 to 128.0 µg/mL. Moreover, these compounds demonstrated significant antioxidant properties compared with those of standard antioxidants according to the results of the DPPH free radical scavenging assay. An evaluation of the growth and proliferation of Ehrlich ascites carcinoma (EAC) cells revealed moderate cell growth inhibition by compounds 5 and 6, with IC50 values of 5958.54 and 5437.17 µg/mL, respectively, as determined via an MTT colorimetric assay. An analysis of the structure-activity relationship (SAR) revealed that the combination of the (p-CH3.C6H4CO-) and halo-aromatic [3-Cl.C6H4CO-] chains with sugar had the highest efficiency in pathogens. Molecular docking studies using AutoDock Vina highlighted compound 7 as a promising inhibitor of the carbapenemase, OmpF, and HmoB proteins, with binding energies of -11.53 kcal/mol, -2.26 kcal/mol, and -30.75 kcal/mol, respectively. A 100-ns molecular dynamics simulation study demonstrated the validity of stable conformation and binding patterns in a stimulating environment. Pharmacokinetic characterization and ADMET predictions indicated favorable drug-like properties. These substantial in vitro and in silico studies demonstrate the importance of additional investigations to confirm the efficacy of MGP derivatives as antimicrobial agents.

Mercury’s plasma environment after BepiColombo’s third flyby

Understanding Mercury’s magnetosphere is crucial for advancing our comprehension of how the solar wind interacts with the planetary magnetospheres. Despite previous missions, several gaps remain in our knowledge of Mercury’s plasma environment. Here, we present findings from BepiColombo’s third flyby, offering a synoptic view of the large scale structure and composition of Mercury’s magnetosphere. The Mass Spectrum Analyzer (MSA), Mass Ion Analyzer (MIA), and Mass Electron Analyzer (MEA) on the magnetospheric orbiter reveal insights, including the identification of trapped energetic hydrogen (H+) with energies around 20 keV e−1 evidencing a ring current, and a cold ion plasma with energies below 50 eV e−1. Additionally, we observe a Low-Latitude Boundary Layer (LLBL), which is a region of turbulent plasma at the edge of the magnetosphere, characterized by bursty ion enhancements, indicating an ongoing injection process in the duskside magnetosphere flank. These observations during cruise phase provide a tantalizing glimpse of future discoveries expected from the Mercury Plasma Particle Experiment (MPPE) instruments after orbit insertion, promising broader impacts on our understanding of planetary magnetospheres.

Calibrating tumor growth and invasion parameters with spectral spatial analysis of cancer biopsy tissues

The reaction-diffusion equation is widely used in mathematical models of cancer. The calibration of model parameters based on limited clinical data is critical to using reaction-diffusion equation simulations for reliable predictions on a per-patient basis. Here, we focus on cell-level data as routinely available from tissue biopsies used for clinical cancer diagnosis. We analyze the spatial architecture in biopsy tissues stained with multiplex immunofluorescence. We derive a two-point correlation function and the corresponding spatial power spectral distribution. We show that this data-deduced power spectral distribution can fit the power spectrum of the solution of reaction-diffusion equations that can then identify patient-specific tumor growth and invasion rates. This approach allows the measurement of patient-specific critical tumor dynamical properties from routinely available biopsy material at a single snapshot in time.

Biogenic synthesis and characterization of antimicrobial, antioxidant, and antihemolytic zinc oxide nanoparticles from Desertifilum sp. TN-15 cell extract

Cyanobacteria, being a prominent category of phototrophic organism, exhibit substantial potential as a valuable source of bioactive compounds and phytonutrients, including liposomes, amino derivatives, proteins, and carotenoids. In this investigation, a polyphasic approach was employed to isolate and characterize a newly discovered cyanobacterial strain from a rice field in the Garh Moor district of Jhang. Desertifilum sp. TN-15, a unique and less explored cyanobacterial strain, holds significant promise as a novel candidate for the synthesis of nanoparticles. This noticeable research gap underscores the novelty and untapped potential of Desertifilum sp. TN-15 in the field of nanomedicine. The characterization of the biogenically synthesized ZnO–NPs involved the application of diverse analytical techniques. Ultraviolet–visible spectroscopy revealed a surface plasmon resonance peak at 298 nm. Fourier transform infrared spectral analysis was utilized to confirm the involvement of biomolecules in the biogenic synthesis and stability. Scanning electron microscopy was employed to probe the surface morphology of the biogenic ZnO–NPs unveiling their size of 94.80 nm and star-shaped. Furthermore, X-ray diffraction analysis substantiated the crystalline nature of ZnO–NPs, with a crystalline size measuring 46 nm. To assess the physical stability of ZnO–NPs, zeta potential and dynamic light scattering measurements were conducted, yielding values of + 31.6 mV, and 94.80 nm, respectively, indicative of favorable stability. The antibacterial capabilities of Desertifilum sp. TN-15 are attributed to its abundance of bioactive components, including proteins, liposomes, amino derivatives, and carotenoids. Through the synthesis of zinc oxide nanoparticles (ZnO–NPs) with this strain, we have effectively used these chemicals to generate nanoparticles that exhibit noteworthy antibacterial activity against Staphylococcus aureus (MIC: 30.05 ± 0.003 µg/ml). Additionally, the ZnO–NPs displayed potent antifungal activity and antioxidant properties, as well as significant antihemolytic effects on red blood cells (IC50: 4.8 µg/ml). Cytotoxicity assessment using brine shrimps revealed an IC50 value of 3.1 µg/ml. The multifaceted actions of the biogenically synthesized ZnO–NPs underscore their potential applications in pharmacological and therapeutic fields. This study proposes a novel method for ZnO–NPs production utilizing the recently identified cyanobacterial strain Desertifilum sp. TN-15, highlighting the growing significance of biological systems in the environmentally friendly fabrication of metallic oxide nanomaterials.

B-240 Multi-omic blood test for early detection of cancer and pre-cancer

Abstract Background The earlier diagnosis of cancer is vital to improve patient survival. Many liquid biopsy technologies are focused on single tumor-derived biomarkers, which limits test sensitivity, especially for early-stage cancers that do not shed sufficient genetic material into the bloodstream. The Dxcover liquid biopsy employs Multi-Omic Spectral Analysis (MOSA) that interrogates a blood sample with Infrared (IR) radiation and produces a distinctive signature that represents the whole biomolecular profile of the sample. This multi-omic blood test analyzes the full complement of tumor and immune-derived markers present within blood derivatives and could facilitate the earlier detection of cancer. The technology can be tuned for high sensitivity (rule out) or high specificity (rule in) depending on the desired application, clinical priorities and international healthcare markets. Methods Three clinical studies have been completed, assessing the technology for the detection of: (1) brain cancer, (2) multiple cancers, and (3) colorectal cancer (CRC) and pre-cancerous lesions. In the first study, we recruited 988 patients prospectively with non-specific symptoms associated with a brain tumor. Secondly, we carried out a large-scale multi-cancer evaluation (n = 2092 patients), targeting eight different cancers. Moreover, the CREATE (ColoREctal cancer & Adenoma Test Evaluation) feasibility study (3) examined 100 CRC, 92 adenoma samples and 104 colonoscopy screening control patients. Results In study 1, the brain cancer algorithm detected 96% of the patients with brain cancer, and 100% of glioblastomas, the most aggressive primary brain tumor. In the multi-cancer study (2), area under the receiver operating characteristic curve values were calculated for the eight cancer types versus symptomatic non-cancer controls: brain (0.90), breast (0.76), colorectal (0.91), kidney (0.91), lung (0.91), ovarian (0.86), pancreatic (0.84) and prostate (0.86). We also assessed the test performance when all eight cancer types were pooled to classify ‘any cancer’ against non-cancer patients. The cancer versus asymptomatic non-cancer classification detected 64% of stage I cancers when specificity was 99% (overall sensitivity 57%). When tuned for higher sensitivity, this model identified 99% of Stage I cancers (with specificity 59%). In the CREATE study, the test reported promising results for pre-cancer detection; at 90% specificity, the test reported sensitivities of 80% for CRC and 59% for advanced adenomas. Conclusions A rapid liquid biopsy that is sensitive to pre-cancerous lesions and early-stage cancer could substantially improve patient outcomes. There is a low barrier to integrating this blood test into existing diagnostic pathways as the technology is rapid, simple to use, and sample preparation is minimal. In addition, the spectroscopic liquid biopsy has the potential to be combined with other orthogonal tests, such as cell-free DNA, which could provide an efficient route to diagnosis. Cancer treatment can be more effective when given earlier, and this low-cost strategy has the potential to improve patient prognosis.

Flare-accelerated Electrons in the Kappa Distribution from X-Ray Spectra with the Warm-target Model

Abstract X-ray observations provide important and valuable insights into the acceleration and propagation of nonthermal electrons during solar flares. Improved X-ray spectral analysis requires a deeper understanding of the dynamics of energetic electrons. Previous studies have demonstrated that the dynamics of accelerated electrons with a few thermal speeds are more complex than those with significantly higher speeds. To better describe the energetic electrons after injection, a model considering energy diffusion and thermalization effects in flare conditions (the warm-target model) has recently been developed for spectral analysis of hard X-rays. This model has demonstrated how the low-energy cutoff, which can hardly be constrained in cold-target modeling, can be determined. However, the power-law form may not be the most suitable representation of injected electrons. The kappa distribution, which is proposed as a physical consequence of electron acceleration, has been applied successfully in RHESSI spectral analysis. In this study, we employ the kappa-form injected electrons in the warm-target model to analyze two M-class flares, observed by RHESSI and the Spectrometer/Telescope for Imaging X-rays, respectively. The best-fit results show that the kappa-form energetic electron spectrum generates lower nonthermal energy than the power-law form when producing a similar photon spectrum in the fit range. We also demonstrated that the fit parameters associated with the kappa-form electron spectrum can be well determined with small uncertainty. Further, the kappa distribution, which covers the entire electron energy range, enables the determination of key electron properties such as total electron number density and average energy at the flare site, providing valuable information on electron acceleration processes.

A fast-filament eruption observed in the Hα spectral line

Context. Solar filament eruptions usually appear to occur in association with the sudden explosive release of magnetic energy accumulated in long-lived arched magnetic structures. The released energy occasionally drives fast-filament eruptions that can be the source regions of coronal mass ejections. A quantitative analysis of high-speed filament eruptions is thus essential to help elucidate the formation and early acceleration of coronal mass ejections. Aims. The goal of this paper is to investigate the dynamic processes of a fast-filament eruption by using unprecedented high-resolution full-disk Hα imaging spectroscopy observations. Methods. The whole process of the eruption was captured in a wide spectral window of the Hα line (±9.0 Å), which allowed for the detection of highly Doppler-shifted plasma. By applying the “cloud model” and obtaining two-dimensional optical thickness spectra, we derived the Doppler velocity; the true eruption profiles (height, velocity, and acceleration); and the trajectory of the filament eruption in 3D space. Results. The Doppler velocity maps show that the filament was predominantly blueshifted. During the main and final process of the eruption, strongly blueshifted materials manifest, traveling with velocities exceeding 250 km s−1. The spectral analysis further revealed that the erupting filament is made of multiple components, some of which were Doppler-shifted approximately to −300 km s−1. We found that the filament eruption attains a maximum true velocity and acceleration of about 600 km s−1 and 2.5 km s−2, respectively, and its propagation direction deviates from the radial direction. On the other hand, downflows manifested as redshifted plasma close to the footpoints of the erupting filament move with velocities of 45–125 km s−1. We interpret these redshifted signatures as draining material and therefore as mass loss of the filament, which has implications for the dynamic and the acceleration process of the eruption. Furthermore, we have estimated the total mass of the Hα filament, resulting in ∼5.4 × 1015 g.

An X-ray fluorescence experimental method for photon-counting detector in computed tomography system

The X-ray fluorescence (XRF) spectrum of specific elements can be utilized in energy calibration, energy resolution measurement, and analysis of energy response functions for photon-counting detectors (PCDs). The applications can be beneficial for PCD threshold accuracy, performance verification, and optimizing image quality. In previous literature, the experimental configuration for the XRF spectrum typically employed a vertical configuration to avoid the influence of the primary X-ray beam. However, such an experimental configuration is constrained by the fixed position of the X-ray source and detector in the computed tomography (CT) system. Hence, the purpose of this study is to investigate a horizontal configuration for XRF measurements and compare the differences in XRF spectrum with vertical configuration. The results indicate that the spectral characteristics of the horizontal and vertical configurations are similar, suggesting that the horizontal configuration could be applied for energy calibration and spectral analysis in PCD-CT systems.

Effects of sound on bluff body aerodynamic characteristics in separated and reattaching flows

The coupling effects between sound and flow on the aerodynamic characteristics of bluff bodies are commonly encountered in engineering practices, such as wind turbine blades and heat exchanger compressors. This study experimentally investigates the effects of sound over a broad range of frequencies (0–400 Hz) and sound pressure levels (80–105 dB) on the streamwise wind pressures on a flat plate in both smooth and turbulent flows. Spectral analysis and proper orthogonal decomposition (POD) are employed to explore the effects of sound on the aerodynamic forces acting on the flat plate. The results show that the effects of sound on wind pressure distributions and separation bubble behaviors over the flat plate depend on both sound frequency and sound pressure level. Furthermore, the findings highlight the role of acoustic resonance, which can increase the fluctuating wind pressure on the plate surface by over 400%. These effects can also be influenced by sound pressure levels. Additionally, the results demonstrate varying degrees and forms of attenuation of sound effects in turbulent flows, depending on the wind flow characteristics.

Gravity and Magnetic Study of the Xitle Volcanic Field, Basin of Mexico – Inferences on the Pre-Eruptive Topography

Results of a gravity and magnetic study over a lava field in the southern Basin of Mexico are used to investigate on lava emplacement and pre-eruptive topography. The characteristics of lava flows depend on multiple factors, including the lava composition, effusion rate, rheology,fluid content and underlying terrain. The ∼2000 years old volcanic field, formed by seven flow units emplaced by the Xitle eruption, covers an extensive area >80 km2 characterized by topographic relief on the Ajusco volcano flank and surrounding plain. The study is conducted on the northern end of the volcanic field. The gravity and magnetic study is based on regional-residual separation, vertical and horizontal derivatives, reduced to the pole, analytical signal, spectral analysis and forward modeling. The regional gravity field shows two anomaly lows in the central sector, with the residual field showing trends of gravity highs. The residual magnetic anomaly is characterized by trends of magnetic highs associated to the lava field. Depths estimated from spectral analysis of gravity and magnetic anomalies show shallow sources at ∼22 m and ∼46 m, and deep sources at ∼469 m and ∼268 m, respectively. The underground sequence is modeled as a volcanoclastic succession of varying thickness. The first vertical derivatives, gradients and analytical signal enhance the anomalies associated to lava thickness variations. Joint gravity and magnetic analysis constraints the deep/shallow anomaly sources in the volcanic field and relations to pre-eruptive structure.

Unraveling the Hybrid Origins of the X-Ray Nonthermal Emission from IGR J17091–3624

We present a comprehensive study based on multiwavelength observations from the NuSTAR, NICER, Swift, Fermi, NEOWISE, and ATCA telescopes during the 2022 outburst of the black-hole X-ray binary IGR J17091–3624. Our investigation concentrates on the heartbeat-like variability in the X-ray emission, with the aim of using it as a tool to unravel the origin of the nonthermal emission during the heartbeat state. Through X-ray timing and spectral analysis, we observe that the heartbeat-like variability correlates with changes in the disk temperature, supporting the disk radiation pressure instability scenario. Moreover, in addition to a Comptonization component, our time-averaged and phase-resolved spectroscopy reveal the presence of a power-law component that varies independently from the disk component. Combined with the radio–X-ray spectral energy distribution fitting, our results suggest that the power-law component could originate from synchrotron self-Compton radiation in the jet, which requires a strong magnetic field of about B = (0.3–3.5) × 106 G. Additionally, assuming that IGR J17091-3624 and GRS 1915 + 105 share the same radio–X-ray correlation coefficient during both the hard and the heartbeat states, we obtain a distance of 13.7 ± 2.3 kpc for IGR J17091–3624.

Computational investigation into the structure, effect of band gap energies, charge transfer, reactivity, thermal energies and NADPH inhibitory activity of a benzimidazole derivative

This work contains computational investigations of a benzimidazole derivative consisting of density functional theory, electronic structure and biological evaluation of a benzimidazole derivative. Density functional theory evaluation were conducted, starting from geometry optimisation, followed by the molecular electrostatic potential, spectral analyses, polarizability studies and thermodynamic analyses via the frequency calculations. Solvent frontier molecular orbital analyses, impact on the properties of the molecule were modelled with the IEFPCM model of solvation. Topological analyses helped to ascertain the molecule’s electronic structure. Biological assessment included pharmacokinetic property evaluation and molecular docking. Pharmacokinetic descriptors were generated using online tools and the molecule was assessed for its efficacy as a drug molecule by comparing with the rules concerning drug-likeness and analysing the descriptors relating to absorption, distribution, metabolism, excretion and toxicity of the molecule. Docking of the molecule with the two targets, 7D3E and 3A1F, yielded a good binding energy of −7.39 and −5.81 kcal/mol respectively.

Spectroscopy of eclipsing compact hierarchical triples

Context. Eclipsing compact hierarchical triples (CHTs) are systems in which a tertiary star orbits an eclipsing binary (EB) in an orbit of fewer than 1000 days. In a CHT, all three stars exist in a space that is less than 5 AU in radius. A low-mass CHT is an interesting case through which we can understand the formation of multiple stars and planets at such small scales. Aims. In this study, we combine spectroscopy and photometry to estimate the orbital, stellar, and atmospheric parameters of stars in a sample of CHTs. Using the complete set of parameters, we aim to constrain the metallicity and age of the systems. Methods. We used time-series spectroscopy to obtain radial velocities (RVs) and disentangled spectra. Using RV modelling, EB light curve modelling, and spectral analysis, we estimated the metallicities and temperatures. Using isochrone fitting, we constrained the ages of the system. We then combined observations of masses, outer eccentricities (e2), orbital periods, and age estimates of the systems from the literature. We compared the distributions of e2, and the tertiary mass ratio, q3 = M3/(M1 + M2), for three different metallicity ranges and two age ranges. Results. We have estimated the masses, radii, temperatures, metallicities, and ages of 12 stars in four CHTs. The CHT CD-32 6459 shows signs of von Zeipel-Lidov-Kozai oscillations, while CD-62 1257 can evolve to form a triple common envelope. The rest of the CHTs are old and have an M-dwarf tertiary. We find that the q3 distribution for CHTs with sub-solar metallicity has a uniform distribution but the systems with solar and above-solar metallicity peak between 0.5 and 1. When dividing them according to their ages, we find the q3 of old systems to be around 0.5. The eccentricity, e2, favours a value of around 0.3 irrespective of metallicity or age. The distributions of q3 and e2 resemble the distributions of the mass ratio and eccentricity of close field binaries.

Adaptive Jamming Mitigation in Single-Antenna Receivers With Spectral Analysis and Switchable Filtering

Adaptive Jamming Mitigation in Single-Antenna Receivers With Spectral Analysis and Switchable Filtering