bluuebunny/crossref_metadata_2025 huggingface dataset:
Neural network reconstruction of density and velocity fields from the 2MASS Redshift Survey
Authors: Lilow Robert , Ganeshaiah Veena Punyakoti , Nusser Adi
Published: July 2024

Aims. Our aim is to reconstruct the 3D matter density and peculiar velocity fields in the local Universe up to a distance of 200 h−1 Mpc from the Two-Micron All-Sky Redshift Survey (2MRS) using a neural network (NN).

Methods. We employed an NN with a U-net autoencoder architecture and a weighted mean squared error loss function trained separately to output either the density or velocity field for a given input grid of galaxy number counts. The NN was trained on mocks derived from the Quijote N-body simulations, incorporating redshift-space distortions (RSDs), galaxy bias, and selection effects closely mimicking the characteristics of 2MRS. The trained NN was benchmarked against a standard Wiener filter (WF) on a validation set of mocks before applying it to 2MRS.

Results. The NN reconstructions effectively approximate the mean posterior estimate of the true density and velocity fields conditioned on the observations. They consistently outperform the WF in terms of reconstruction accuracy and effectively capture the nonlinear relation between velocity and density. The NN-reconstructed bulk flow of the total survey volume exhibits a significant correlation with the true mock bulk flow, demonstrating that the NN is sensitive to information on “super-survey” scales encoded in the RSDs. When applied to 2MRS, the NN successfully recovers the main known clusters, some of which are partially in the Zone of Avoidance. The reconstructed bulk flows in spheres of different radii less than 100 h−1 Mpc are in good agreement with a previous 2MRS analysis that required an additional external bulk flow component inferred from directly observed peculiar velocities. The NN-reconstructed peculiar velocity of the Local Group closely matches the observed Cosmic Microwave Background dipole in amplitude and Galactic latitude, and only deviates by 18° in longitude. The NN-reconstructed fields are publicly available.
Emergence hour-by-hour of r-process features in the kilonova AT2017gfo
Authors: Sneppen Albert , Watson Darach , Damgaard Rasmus , Heintz Kasper E. , Vieira Nicholas , Väisänen Petri , Mahoro Antoine
Published: July 2024

The spectral features in the optical/near-infrared counterparts of neutron star mergers (kilonovae, KNe) evolve dramatically on hourly timescales. To examine the spectral evolution, we compiled a temporal series that was complete at all observed epochs from 0.5 to 9.4 days of the best optical/near-infrared (NIR) spectra of the gravitational-wave detected kilonova AT2017gfo. Using our analysis of this spectral series, we show that the emergence times of spectral features place strong constraints on line identifications and ejecta properties, while their subsequent evolution probes the structure of the ejecta. We find that the most prominent spectral feature, the 1 μm P Cygni line, appears suddenly, with the earliest detection at 1.17 days. We find evidence in this earliest feature for the fastest yet discovered kilonova ejecta component at 0.40–0.45c. Across the observed epochs and wavelengths, the velocities of the line-forming regions span nearly an order of magnitude, down to as low as 0.04–0.07c. The time of emergence closely follows the predictions for Sr II because Sr III combines rapidly under local thermal equilibrium (LTE) conditions. The transition time between the doubly and singly ionised states provides the first direct measurement of the ionisation temperature. This temperature is highly consistent with the temperature of the emitted blackbody radiation field at a level of a few percent. Furthermore, we find the KN to be isotropic in temperature, that is, the polar and equatorial ejecta differ by less than a few hundred Kelvin or ≲5%, in the first few days post-merger based on measurements of the reverberation time-delay effect. This suggests that a model with very simple assumptions, with single-temperature LTE conditions, reproduces the early kilonova properties surprisingly well.
Evolutionary pathways of disk galaxies with different sizes
Authors: Ma Hong-Chuan , Du Min , Ho Luis C. , Sheng Ming-Jie , Liao Shihong
Published: July 2024

Aims. This work delves into the complex interaction between disk galaxies and their host dark matter halos. It specifically focuses on scenarios with minimal external (“nurture”) influences such as mergers and substantial tidal interactions. The study uncovers the varied evolutionary paths of disk galaxies of different sizes, shaped by the initial conditions of their parent dark matter halos and subsequent internal processes. Thus, we can explore the “nature” of these galaxies.

Methods. From the TNG50 simulation, a sample of 836 central disk galaxies with tiny stellar halos is chosen to study the inherent evolution of galaxies driven by nature. These galaxies are classified as compact, normal, or extended by referencing their locations on the mass-size (M⋆ − R½) diagram. Scaling relations were then established to measure the correlations driven by internal mechanisms.

Results. This research demonstrates the distinctive evolutionary pathways of galaxies with different sizes in IllustrisTNG simulations, primarily driven by their nature. It is confirmed that disk galaxies inherit the angular momentum of their parent dark matter halos. More compact galaxies form earlier within halos that exhibit a lower specific angular momentum through heightened star formation during the early phase at redshifts above 2. During the later phase, the size of extended galaxies experiences more pronounced growth by accreting gas with a high angular momentum. Additionally, we reveal that many key characteristics of galaxies are linked to their mass and size: (1) compact galaxies tend to exhibit higher metal content, proportional to the potential well, M⋆/R½; (2) compact galaxies host more massive bulges and black holes, along with a higher central concentration. Furthermore, our analysis indicates that galaxies of all types continue to actively engage in star formation, with no evident signs of quenching attributed to their varying sizes and angular momenta.
The chemical composition of CO-rich comet C/2023 H2 (Lemmon)
Authors: Lippi M. , Ferellec L. , Opitom C. , Faggi S. , Mumma M. J. , Villanueva G. L.
Published: July 2024

Aims. We report on the composition of comet C/2023 H2 (Lemmon) (hereafter C/2023 H2) as measured with CRIRES+ at VLT/ESO, under the Director Discretionary Time program: 2112.C-5015.

Methods. We observed C/2023 H2 between November 24 and 27, 2023, after perihelion and during its close approach to Earth. We used three settings sampling the spectral region from ≈2.5 to 5 µm, to search for fluorescence emission lines of H2O, HCN, C2H2, NH3, C2H6, H2CO, CH3OH, CH4, and CO.

Results. C/2023 H2 spectra are dominated by signatures from hyper-volatile species, namely CO, C2H6, and CH4, while it is particularly difficult to identify lines from less volatile species such as water or methanol. When compared to other comets, C/2023 H2 has an overall typical-to-enriched composition, with CO showing one of the highest infrared values reported so far in Solar System comets within 2 au from the Sun. In this respect, C/2023 H2 shares many similarities with C/2013 R1 (Lovejoy), C/2009 P1 (Garrad), and C/1999 T1 (McNaught-Hartley), although still being rather unique. Results from the analysis of optical spectra (≈300–650 nm) obtained on November 16, 2023, using the Intermediate Dispersion Spectrograph at the Isaac Newton Telescopes are consistent with the infrared ones.

Conclusions. Assuming that the composition of C/2023 H2 is original, this comet most likely formed in a region of the disc where CO was particularly enriched, or it could have been captured from other planetary systems forming in the Sun’s birth cluster. Similarities with a few other comets suggest the existence of a sub-class of CO-enriched comets, which may be currently under-sampled. Alternatively, water sublimation may have been ineffective due to the presence of a thick dust mantle covering the nucleus surface.
The maximum black hole mass at solar metallicity
Authors: Vink Jorick S. , Sabhahit Gautham N. , Higgins Erin R.
Published: July 2024

We analyse the current knowledge and uncertainties in detailed stellar evolution and wind modelling to evaluate the mass of the most massive stellar black hole (BH) at solar metallicity. Contrary to common expectations that it is the most massive stars that produce the most massive BHs, we find that the maximum MBHMax ≃ 30 ± 10 M⊙ is found in the canonical intermediate range between MZAMS ≃ 30 and 50 M⊙ instead. The prime reason for this seemingly counter-intuitive finding is that very massive stars (VMS) have increasingly high mass-loss rates that lead to substantial mass evaporation before they expire as stars and end as lighter BHs than their canonical O-star counterparts.
Rotational state-to-state transition rate coefficients for H2O + H2O collisions at nonequilibrium conditions
Authors: Mandal Bikramaditya , Zoltowski Michal , Cordiner Martin , Lique Francois , Babikov Dmitri
Published: July 2024

Aims. The goal is to develop a database of rate coefficients for rotational state-to-state transitions in H2O + H2O collisions that is suitable for the modeling of energy transfer in nonequilibrium conditions, in which the distribution of rotational states of H2O deviates from local thermodynamic equilibrium.

Methods. A two-temperature model was employed that assumed that although there is no equilibrium between all possible degrees of freedom in the system, the translational and rotational degrees of freedom can be expected to achieve their own equilibria independently, and that they can be approximately characterized by Boltzmann distributions at two different temperatures, Tkin and Trot.

Results. Upon introducing our new parameterization of the collisional rates, taking into account their dependence on both Tkin and Trot, we find a change of up to 20% in the H2O rotational level populations for both ortho and para-H2O for the part of the cometary coma where the nonequilibrium regime occurs.
MUSE spectroscopy of the high abundance discrepancy planetary nebula NGC 6153
Authors: Gómez-Llanos V. , García-Rojas J. , Morisset C. , Monteiro H. , Jones D. , Wesson R. , Boffin H. M. J. , Corradi R. L M.
Published: July 2024

Context. The abundance discrepancy problem in planetary nebulae (PNe) has long puzzled astronomers. NGC 6153, with its high abundance discrepancy factor (ADF ~ 10), provides a unique opportunity to study the chemical structure and ionisation processes within these objects.

Aims. We aim to understand the chemical structure and ionisation processes in this high-ADF nebula by constructing detailed emission line maps and examining variations in electron temperature and density. This study also explores the discrepancies between ionic abundances derived from collisional and recombination lines, shedding light on the presence of multiple plasma components.

Methods. We used the MUSE spectrograph to acquire IFU data covering the wavelength range 4600–9300 Å with a spatial sampling of 0.2 arcsec and spectral resolutions ranging from R = 1609 to R = 3506. We created emission line maps for 60 lines and two continuum regions. We developed a tailored methodology for the analysis of the data, including correction for recombination contributions to auroral lines and the contributions of different plasma phases.

Results. Our analysis confirmed the presence of a low-temperature plasma component in NGC 6153. We find that electron temperatures derived from recombination line and continuum diagnostics are significantly lower than those derived from collisionally excited line diagnostics. Ionic chemical abundance maps were constructed, considering the weight of the cold plasma phase in the H I emission. Adopting this approach we found ionic abundances that could be up to 0.2 dex lower for those derived from CELs and up to 1.1 dex higher for those derived from RLs than in the case of a homogeneous H I emission. The abundance contrast factor (ACF) between both plasma components was defined, with values, on average, 0.9 dex higher than the ADF. Different methods for calculating ionisation correction factors (ICFs), including state-of-the-art literature ICFs and machine learning techniques, yielded consistent results.

Conclusions. Our findings emphasise that accurate chemical abundance determinations in high-ADF PNe must account for multiple plasma phases. Future research should focus on expanding this methodology to a broader sample of PNe, with spectra deep enough to gather physical condition information of both plasma components, which will enhance our understanding of their chemical compositions and the underlying physical processes in these complex objects.
Gaia DR3 asteroid reflectance spectra: L-type families, memberships, and ages
Authors: Balossi R. , Tanga P. , Sergeyev A. , Cellino A. , Spoto F.
Published: July 2024

Context. The Gaia Data Release 3 (DR3) contains reflectance spectra at visible wavelengths for 60 518 asteroids over the range between 374–1034 nm, representing a large sample that is well suited to studies of asteroid families.

Aims. We want to assess the potential of Gaia spectra in identifying asteroid family members. Here, we focus on two L-type families, namely Tirela/Klumpkea and Watsonia. These families are known for their connection to Barbarian asteroids, which are potentially abundant in calcium-aluminum rich inclusions (CAIs).

Methods. Our method is based (1) on a color taxonomy specifically built on Gaia data and (2) the similarity of spectra of candidate members with the template spectrum of a specific family.

Results. We identified objects in the halo of Tirela/Klumpkea, along with possible interlopers. We also found an independent group of eight asteroids erroneously linked to the family by the hierarchical clustering method (HCM). Consequently, the knowledge of the size distribution of the family has been significantly improved, with a more consistent shape at the larger end. The Watsonia family is a more intricate case, mainly due to its smaller size and the less marked difference between the spectral types of the background and of the family members. However, the spectral selection helps identify objects that were not seen by HCM, including a cluster separated from the family core by a resonance.

Conclusions. For both families, the V-shape is better defined, leading to a revised age estimation based on the memberships established mainly from spectral properties. Our work demonstrates the advantage of combining the classical HCM approach to spectral properties obtained by Gaia for the study of asteroid families. Future data releases are expected to further expand the capabilities in this domain.
New numerical models of atomic diffusion in the atmospheres of cool Ap stars, including ambipolar diffusion of hydrogen
Authors: Alecian G. , Stift M. J.
Published: July 2024

Context. Ambipolar diffusion of hydrogen gives an additional upward thrust to metals that diffuse in the atmosphere of Ap stars. Its quantitative effect on the build-up of abundance stratification due to atomic diffusion that produces the observed abundance anomalies in Ap stars has not been evaluated so far.

Aims. The purpose of this work is to quantify this effect throughout the stratification process of metals inside the atmosphere.

Methods. We used our code CARATMOTION to compute the time-dependent atomic diffusion of four metals (Mg, Ca, Si, and Fe) in the atmosphere of a main-sequence star with an effective temperature of 8500 K, which is a typical temperature of Ap stars. The results, including ambipolar diffusion of H, are compared to results obtained without this process.

Results. Our main result is that ambipolar diffusion must be included in any calculation of atomic diffusion in Ap star atmospheres, at least for stars with Teff ≲ 10 000 K. We show that this concerns all metals, even those that are well supported by the radiation field, such as Fe. The crucial role of the stellar mass-loss rate is confirmed; it remains a determining parameter that is constrained, but still free in our calculations. We also present 3D calculations of Ca distributions in magnetic atmospheres. Questioning the interest of systematic searches for stationary solutions (which can often only be reached after a long evolutionary process), we note that remarkable behaviour can occur during the transient phases of the stratification build-up.
Tracking Advanced Planetary Systems (TAPAS) with HARPS-N
Authors: Maciejewski G. , Niedzielski A. , Goździewski K. , Wolszczan A. , Villaver E. , Fernández M. , Adamów M. , Sierzputowska J.
Published: July 2024

Aims. The star HD 118203, classified as a K0 subgiant, was known to harbour a transiting hot Jupiter planet on a 6.1-day eccentric orbit. Previous studies also revealed a linear trend in the radial velocity (RV) domain, indicative of a companion on a wide orbit. Such a hierarchical orbital architecture could be helpful in studies of the origins of hot Jupiters.

Methods. We acquired precise RV measurements over 17 yr using the 9.2 m Hobby-Eberly Telescope and the 3.6 m Telescopio Nazionale Galileo. Combining these observations with space-born photometric time series from the Transiting Exoplanet Survey Satellite, we constructed a two-planetary model for the system. Astrometric observations from HIPPARCOS and Gaia were used to constrain the orbital inclination of the wide-orbit companion and its mass. Numerical simulations were used to investigate the dynamics of the system. The photometric data were searched for additional transit-like flux drops.

Results. We found that the additional companion is an 11-Jupiter mass planet orbiting HD 118203 on a 14-yr moderately eccentric orbit, constituting a hierarchical planetary system with the hot Jupiter. Both planets were found to be dynamically decoupled mainly due to the general relativistic apsidal precession of the inner planet, marginalising secular interactions. The orbits of both planets might have a relatively low mutual inclination unless the longitudes of the ascending node differ substantially. This configuration favours the coplanar high-eccentricity migration as a path to the present-day orbital configuration. No other transiting planets with radii down to 2 Earth radii and orbital periods less than 100 days were found in the system.
Size matters: are we witnessing super-Eddington accretion in high-redshift black holes from JWST?
Authors: Lupi Alessandro , Trinca Alessandro , Volonteri Marta , Dotti Massimo , Mazzucchelli Chiara
Published: July 2024

Observations by the James Webb Space Telescope of the Universe at z ≳ 4 have shown that massive black holes (MBHs) appear to be extremely overmassive compared to the local correlation for active galactic nuclei. In some cases, these objects might even reach half the stellar mass inferred for the galaxy. It has become a great challenging for theoretical models to understand how these objects formed and grew to these masses. Different ideas range from heavy seed to super-Eddington accretion phases. We take a different approach and try to infer how accurate these MBH mass estimates are and whether we really need to revise our physical models. By considering how the emerging spectrum (both the continuum and the broad lines) of an accreting MBH changes close to and above the Eddington limit, we infer a much larger uncertainty in the MBH mass estimates relative to that of local counterparts. The uncertainty is up to an order of magnitude. We also infer a potential preference for lower masses and higher accretion rates, which i) moves accreting MBHs closer to the local correlations, and ii) might indicate that we witness a widespread phase of very rapid accretion for the first time.
Searching for the grand tack in exoplanetary data
Authors: Cridland A. J.
Published: July 2024

The grand tack model, more generally called the Masset and Snellgrove mechanism, is a planetary migration model whereby two giant planets via interactions with their natal disk migrated to larger orbital radii. While its relevance in our own Solar System remains in question, the fact that the Masset and Snellgrove mechanism is a general hydrodynamical effect implies that it may have occurred in another planetary system. In this study I searched through exoplanet data for evidence of the Masset and Snellgrove mechanism, which requires that (1) the inner of the two planets is more massive than the outer planet; (2) the planets are sufficiently massive that their gravity-induced gap overlaps; and (3) they orbit at sufficiently close radii that their co-rotation regions also overlap. The last two requirements are met when the planets orbit with a 3:2 mean motion resonance. I do not find conclusive evidence for a grand tack-like system, but find some evidence for planet formation at the edge of a planet-induced protoplanetary disk gap in three systems.
Exploring the Impact of Sustainable Stir Casting Process Parameters on the Tensile Strength of AA2017-AlNp Composites: A Taguchi Technique Approach
Authors: Rajasekaran Senthil , Mohanavel Vinayagam
Published: July 2024

By integrating sustainable materials and practices into the fabrication process of the AA2017/AlN composites, you can enhance their environmental performance and contribute to a more sustainable future for materials engineering.An attempt was made to investigate the impact of stir casting parameters on the tensile strength (TS) of AlN particles reinforced AA2017 matrix composites. The composites containing 0, 5, 10 and 15 wt.% AlN incorporated AA2017 matrix developed via stir casting route. Taguchi’s L16 orthogonal design layout consisting of four input parameters and four levels were chosen to fabricate the composites. The selected process parameters were stirring time (min), stirring speed (rpm), reinforcement (wt.%) and melting temperature (oC). Similarly, the output response was considered as tensile strength (TS) and the test was performed by universal testing machine (UTM). Taguchi approach was engaged to predict the finest setting of casting parameters to achieve the superior TS of the proposed AA2017/AlN composites. The statistical results revealed that the maximum TS was produced by stirring time of 8 min, stirring speed of 500 rpm, reinforcement content of 15 wt.% and melting temperature of 700oC. ANOVA results found that reinforcement (53.95%) was the notable factor for affecting the TS, next by stirring time (37.20%). By leveraging sustainable materials and manufacturing practices, this study contributes to the advancement of environmentally friendly materials engineering practices, paving the way for a more sustainable future in the field.
Sustainability in magnetic metal-carbon nanocomposites: A comprehensive review of manufacturing, characterization, and applications
Authors: Sharma Mukul , Purohit Yash , Deshwal Dhruv , Owhal Ayush , Pingale Ajay D. , Belgamwar Sachin U.
Published: July 2024

Magnetic metal-carbon nanocomposites (MMCN) are emerging as sustainable materials, consisting of magnetic metals or alloys and carbon-based materials like CNT, graphene (Gr), carbon fiber (CF), and activated carbon. These materials possess unique magnetic properties that depend on various factors, such as preparation conditions, metal content, and phase composition. Incorporating carbon-based materials into magnetic metals has been observed to enhance their magnetic properties, including magnetic strength and moment. Researchers employ a range of tests to characterize these materials, such as FTIR, XRD, FESEM, TEM, BET, and VSM. Carbon-based materials such as CNT, graphene, etc., have been used as filler materials to reinforce the metal matrix because of their sustainability, tendency to integrate, and low cost. Further, they enhance the tribological performance and mechanical strength, provide corrosion resistance and improve electrical and thermal properties. Additionally, the addition of filler magnetic material in single or hybrid form into the carbon matrix increases the scope of application of MMCN. These composites are widely used in the application of biomedical, semiconductors, tribology, fuel cells, etc. In the present study, a comprehensive review has been carried out to provide a view of the fabrication aspect of the MMNC and to understand the role of the reinforcement method used to fabricate the composites. Finally, it covers different uses of the MMCN, which can lead to an eco-friendly environment.
Experimental Material Characterization and Formability studies on Aluminium Alloy (AA 8011)
Authors: Ratna Babu Kuraku , Prashanth Sattenapelli , Ganesh Kethe , Kiran Kumar Gone
Published: July 2024

Operations for sheet metal shaping are essential to the production of many different kinds of goods. But there is still a problem with plastic fragility in this industry, which frequently results in faulty goods. To solve this problem during production, it’s critical to take into account a number of factors, including the Forming Limit Diagram (FLD). In this work, the formability of the Aluminum Alloy (AA8011) at strain rates of 0.01 mm/s at ambient temperature, 100 °C, and 150 °C has been investigated. The Nakajima test was used to execute stretch forming in order to achieve the study’s results. The material’s restricting stresses increased as temperatures increased, according to the outcomes, which were examined utilizing fractography investigations carried out under a scanning electron microscope and simulations carried out with LS-dyna software. This work will help create more productive and successful sheet metal-forming techniques by offering insightful information on the formability of AA 8011 sheet at extreme temperatures.
Experimental Analysis on Turning of Super Duplex UNS 32750 Steel Using Minimum Quantity Lubrication Process
Authors: Kolli Murahari , Sankara Babu Chinka Siva , Vinjarapu Sankararao , Satyanarayana Kosaraju , Kalpana K. , Ihsan Muhamed
Published: July 2024

Current production trends necessitate extensive use of cutting fluids, resulting in adverse climatic changes and increasing industry expenses. Modern manufacturing businesses are looking for new ways to meet the demands for faster machining rates, less waste, and improved product quality while also lowering manufacturing costs. Material removal rate (MRR) and surface roughness (SR) of the work piece machined with coated tools are all evaluated. Cutting speed (CS), pressure flow (PF), and depth of cut(DOC), are the input parameters. An aerosol mixture of air and oil was used to give the least amount of lubrication. To assess the relative performance tuning with the MQL setup, an investigation was conducted. When compared to dry turning, the MQL system for turning super duplex stainless steel UNS 32750 has shown to be more effective. The MQL technique significantly improves cutting performance in terms of increasing tool life and improving machined component quality.
Effect of aging time on the sustainability of microstructure, corrosion, and mechanical of Al6061
Authors: Damilare Baruwa Akinsanya , Elizabeth Makhatha Mamookho
Published: July 2024

The high corrosion resistance of Al 6061 has made the material for wide applications. However, for its sustainability in applications, the mechanical properties and corrosion resistance have to be improved through modifications such as heat treatment. Therefore, the study investigates the influence of the aging time on the corrosion resistance, mechanical properties, and microstructure of the material after heat treatment. Al 6061 will be investigated at T0, T4, and T6- for 30 mins, 60 mins and 90 mins using water as the cooling media. The microstructure was observed using light microscope, the corrosion rate was determined by potentiostat using seawater as the electrolyte, and hardness was measured through Brinell’s scale and the tensile test machine to investigate its UTS and elongation. It was discovered that the samples quenched before aging had improved properties compared to the samples that were normalized. The colling method shows a greater impact on the properties of the material.
Manufacturing and Evaluation of jute fiber with gypsum and walnut shell powder Composite with Epoxy Resin
Authors: Laxmikath Bhakkad Raj , Sri Charan Sirigamalla , Buddi Tanya , Obad S.
Published: July 2024

The purpose of this study is to examine the mechanical and physical characteristics of jute fibre composites reinforced with different sizes of gypsum and walnut shell powder in an epoxy resin matrix using hand layup technique. Using a 3x3 orthogonal array that encompasses three parameters at three levels each, composites were created based on a Taguchi design technique. Tensile, flexural, and impact strength tests were performed on the composites, along with thickness swelling and water absorption testing and ANOVA analysis was performed for each test using Minitab. The results show that temperature, size, and composition of the walnut shell powder all improved flexural strength, but composition, size of the walnut shell powder declines the tensile strength upon increasing them, and higher temperatures of jute fiber increased tensile strength. The impact strength was constant in all combinations. Higher temperature produced composites showed better rates of water absorption, especially those with more powdered walnut shell. Notably, the composite with 0% walnut shell powder (size <1mm) produced at ambient temperature showed the maximum tensile strength, whereas the composite heated to 80°C with 5% walnut shell powder (size <4mm) showed the highest flexural strength. The mechanical characteristics and water absorption behaviour of jute fiber-walnut shell powder composites can be optimised for a variety of applications with the help of these results.
Comparative Study of Destructive Method and Non-destructive with Ultra-Sonic Pulse Velocity Method
Authors: Katare Shivam , Kundil Abhilash Pideka , Helena Raj Vijilius , Arora Deepika , Gupta Manish , Alhussainy Ali K. , Reddy M. Venkateswar
Published: July 2024

The appropriate percentages of cement, fine aggregates, coarse aggregates, and water are utilized to make concrete. Due to its relatively low price and widespread availability, it is a ubiquitous building material. Concrete in its fresh state can also be molded into any desired shape and size. Strength and durability are two of concrete’s most important characteristics (particularly when used for structural purposes). Verify the concrete’s compressive strength before placing it under the expected loads. NDT methods, both destructive and non-destructive, can be used to assess the compressive strength of hardened concrete. A non- destructive test does not harm the concrete specimen, whereas a destructive test (DT) crushes the cast specimen until it breaks. In non-destructive testing, materials, components or assemblies are inspected, tested or evaluated without destroying their serviceability. This study compares the compressive strength of concrete utilising an ultrasonic pulse velocity approach, which is both destructive and non-destructive. Concrete cubes measuring 150 mm by 150 mm by 150 mm were created using the concrete mix grades 25N/mm2 and 30N/mm2, and they were allowed to cure for 28 days. There were 12 cubes produced and used for the study. The determine compressive strength between destructive and non -destructive (ultra-sonic pulse velocity) test method.
Advanced Interdisciplinary Approach in Construction Industry: Internet of Things (IOT)
Authors: Srivastava Shashank , Asha V. , B Navajyoth , Nijhawan Ginni , Krishna P.V.V.S.S.R. , Al-Saady Fouad A. , Rao K. Nishanth
Published: July 2024

Promoting construction, enhancing safety and multiple functions of IoT. Since the beginning of Fourth Industrial Revolution, digitalization becomes a fundamental function of all the construction project and bring all the project to a brand new practical and efficient world. IoT (Internet of Things), which refers to a large network of connected sensors and devices capable of autonomously exchanging and analysing data in real-time, belongs to a major facilitator of this function. To have an idea of the importance of this technology in the construction field, one must think about it as an instrument to decrease labour cost, reduce project repair time, and save material cost by automating and networking process. Among these could be automated assessment of a construction site to alert about hazards that might affect workers’ lives. IoT alarms and delivered insights reduce risks and keep the working place of the construction workers safe. Overall, it is claimed in the paper that IoT has a significant number of applications in the construction sector- starting from the project management to the quality testing of work. These are just some of the applications of IoT and as the field evolves, more benefits and value-added services would be seen arising. In this regard, IoT will also have a key role in communication and coordination between many stakeholders involved, hence creating collaboration and cooperation for a healthy conductive environment with openness among all. Its integration with latest technologies like digitization of data, data analytics, AI, facilitate predictive maintenance decisions and end up making less mistakes. Although there is a huge potential for IoT to develop in the construction industry, so far, it is not utilised in a large scale. There are some limitations to be reduced like the cybersecurity, interoperability, and workforce readiness among others that need to be addressed or enhanced in due time. Industry participants must join hands to overcome these issues. It would be an understatement to say that IoT has the ability to completely revolutionize the construction industry. In article it illustrates how the Internet of Things is transforming the building sector and offers guidance on how interested parties can take advantage of this technology to raise project sustainability, output, and safety. By adopting innovation and digitization, those involved in the construction industry can take advantage of new moves for efficacy and efficiency in systems performance.
Parametric Optimization of Circular Elevated Water Tanks Under Various Capacities and Seismic Conditions
Authors: Kumar Kalagatoori Archakam Jayasheel , Nagpal Amandeep , Polepaka Sanjeeva , Kumar Chandra Pradeep , Saeed Hazim Y. , Pahwa Shilpa , Murali Krishna Chintala
Published: July 2024

The elevated water tank comprises important structural elements which includes slabs, beams, columns, and footings, facilitating the transfer of loads amongst these contributors and subsequently to the subgrade of the soil. This paper goals is to comprehensively analyze the structural behaviours exhibited by elevated water tanks underneath various loading conditions. The behaviours of multiplied water tanks variety underneath various styles of loadings, inclusive of dead, live, and seismic loads, that are comprehensively analyzed. This paper primarily aims to conduct a hydrostatic evaluation of circular water tanks and emphasizes the necessity of a parametric study. To obtain this goal, 2, 2.5, and 3 lakh litters of tanks are being considered for the analysis which are all examined underneath area III seismic situations whilst keeping a normal height and varying diameters during the simulation. The examination focuses on carrying out a comparative evaluation of critical structural parameters, such as moment, maximum displacement, and maximum base shear. By means of analysing those parameters across various tank capacities, precious insights into the structural reaction of circular elevated water tanks under seismic loading conditions are gained. Those findings contribute to enhancing the design and overall performance of such structures, enhancing their resilience and protection in earthquake-susceptible regions.
Study on UPQC Integration Benefits in a Hybrid Solar Wind Energy System
Authors: Baswaraju Swathi , Siva Prasada Raju V. , Sobti Rajeev , Kumar Ashwani , Raed Rawya , Paul Surovi , Karthik N.
Published: July 2024

The researchers are focusing on harnessing the electricity form the renewable energy resources by overcoming the challenges faced by them due its variable nature. This study discusses the developing significance of renewable energy sources (RES), in particular wind and solar electricity, in meeting future electricity demands. India’s geographical length is highlighted as beneficial for integrating variable renewable energy outputs into its grid. The paper also addresses Power-quality (PQ) issues springing up from integrating renewable energy sources, proposing solutions including single and Unified active power filter (SUAPF) and distributed Static Compensators (DSTATCOM). The work examines power quality issues associated with grid-related solar PV systems and the combination of Unified Power Quality Conditioners (UPQCs) in hybrid solar-wind systems. The analysis of the UPQC integration with the solar wind energy based hybris system concludes the enhancement in the power quality issues such as total harmonic distortions along with balancing the reactive power in the line.
Expand or not? trade-offs of the remanufacturer on recycling channels
Authors: Qi Xin , Zhang Tao
Published: July 2024

The integration of online trading has emerged as a crucial driver of operational efficiency in the reverse supply chain. This study expands the recycling model to include three distinct scenarios: basic-offline recycling (BR), single-platform recycling (SR), and dual-platform recycling (DR). The research delves into the implications of varying platform numbers, profit-sharing contracts, consumer recycling preferences, and recycling price adjustment speeds on supply chain stability within a multi-period decision-making framework. Findings reveal that the SR model is not always yield higher profits for remanufacturers through lower revenue allocation proportions to platforms, in stark contrast to the DR model. Furthermore, rapid decision adjustments do not consistently enhance the stability of the recycling system across multiple decision cycles. Remanufacturers’ expansion strategies are significantly impacted by the costs associated with acquiring e-waste from individual recyclers. Importantly, an excess of platforms does not always result in favorable outcomes. Conversely, the SR model proves superior to the DR model in practical contexts that may arise. These insights offer valuable guidance to remanufacturers seeking to develop viable expansion strategies that foster mutually beneficial relationships among individual recyclers, remanufacturers, and platforms.
Sterbewünsche im Kontext stationärer Altenpflegeeinrichtungen – Belastungen und Bedürfnisse von Pflegenden sowie Aspekte für eine einrichtungsinterne Diskussion und Positionsfindung
Authors: Jentschke Elisabeth , Rabe Antonia , Armbrecht Helena , Lang Frieder R. , Heckel Maria
Published: July 2024

Hintergrund Pflegende in der stationären Altenhilfe werden aufgrund ihrer engen Interaktion mit den Sterbewünschen der pflegebedürftigen Personen konfrontiert, welche den Wunsch nach dem assistierten Suizid umfassen können. Die geschäftsmäßige Förderung der Selbsttötung ist seit der Nichtigkeitserklärung von §217 StGB in Deutschland nicht mehr untersagt. Wenige Studien untersuchen bisher die Belastungen und Unterstützungsbedürfnisse von Pflegenden. Des Weiteren fehlen Anhaltspunkte entlang derer einrichtungsinterne Positionen zu diesem Themenkomplex erarbeitet werden können.

Ziele Erfassung von Belastungen und Bedürfnissen der Pflegenden in der stationären Altenpflege am Beispiel der Diakonie im Zusammenhang mit Sterbewünschen und dem assistierten Suizid sowie Identifikation relevanter Aspekte für eine einrichtungsinterne Positionierung.

Methode Befragung von Pflegenden mittels eines selbstentwickelten, nicht-validierten Fragebogens. Anschließende Durchführung von semistrukturierten Interviews mit im Pflegekontext ausgewiesenen Fachpersonen zu ausgewählten Fragebogenergebnissen und Praxislösungen zum Umgang mit Sterbewünschen und dem assistierten Suizid in der stationären Altenhilfe. Die Daten wurden deskriptiv sowie mit der fokussierten Inhaltsanalyse nach Kuckartz analysiert.

Ergebnisse Die Daten von 434 Pflegenden und 8 Fachpersonen wurden ausgewertet. 98% (n=423) der Pflegenden gaben in der Befragung an, Erfahrungen mit der Äußerung von Sterbewünschen gemacht zu haben, während 93% (n=403) verneinten, dass es in ihrer Einrichtung schon einmal einen assistierten Suizid gegeben habe. Zudem wünschten sich zwei Drittel (n=299) der Befragten im Umgang mit Sterbewünschen und Wünschen nach dem assistierten Suizid Unterstützung durch Supervision, Fortbildungen und klare Handlungsanweisungen. Aus den Interviews mit fachlich erfahrenen Personen (n=8) ließen sich eine angemessene Qualifizierung der Pflegenden, das Vorhandensein eines Netzwerks, die Teamkultur sowie die zeitlichen Ressourcen als relevante Faktoren erkennen, anhand derer die Positionen verschiedener Interessengruppen zum Umgang mit dem assistierten Suizid beschrieben werden können.

Schlussfolgerung Der Umgang mit Sterbewünschen und Wünschen nach dem assistierten Suizid ist für Pflegende der stationären Altenhilfe von praktischer Relevanz. Die Generalisierbarkeit der Ergebnisse ist aufgrund des diakonischen Kontextes beschränkt und ist für andere Settings zu prüfen. Auf Basis der Studienergebnisse wurde von 3 Fachverbänden der Diakonie Bayern eine Arbeitshilfe zur Unterstützung einer gemeinschaftlichen einrichtungsinternen Positionierung für alle Mitarbeitenden erstellt.
Oral Colonization by Different Candida Species: First Comparative Study between Denture and Nondenture Wearers in Tunisia
Authors: Benyounes Oussama , Bekri Sana , Belgacem Sameh , Labidi Amel , Khemis Mehdi , Mansour Lamia
Published: July 2024

Objective This study aimed to compare different Candida species present in patients with and without removable dentures to identify alterations in biofilm composition following denture wear within a Tunisian population.

Materials and Methods A cross-sectional study was conducted, comprising a group of patients wearing removable dentures (test group) and a control group without dentures. In the test group, two mycological samples were obtained: one from the prosthetic intaglio and another from the osteomucosal area bearing the denture. For the control group, mycological samples were collected from the oral mucosa. The collected swabs were cultured on CHROMagar Candida medium, and yeast counts were quantified as colony forming units (CFUs). Candida species were identified through chromogenic analysis.

Statistical Analysis The normality of quantitative variables was evaluated using the Kolmogorov–Smirnov's test. To compare means and ranks between the test and control groups, the independent samples t-test and the Mann–Whitney's U test were employed, respectively. Qualitative variables were compared using Fisher's exact test. Statistical significance was determined at a critical uncertainty value of p < 0.05.

Results A total of 150 participants were involved in this study, with 75 patients in each group. Wearing an acrylic removable denture was found to increase the number of detected Candida species (p < 0.001) and significantly increases the overall growth of Candida spp. (p = 0.001). Specifically, the numbers of CFUs of Candida tropicalis and Candida glabrata were elevated in denture wearers (p < 0.001).

Conclusion Findings stemming from this study indicate that removable dentures promote the growth of Candida species. This can be a predisposing factor for Candida-associated denture stomatitis in cases of poor oral hygiene or compromised immunity. Therefore, it is imperative to emphasize the fabrication of high-quality dentures and the implementation of rigorous postdenture maintenance protocols to prevent or limit Candida infection.
Analyzing Cell-free Genomic DNA in Spent Culture Media: Noninvasive Insight into the Blastocysts
Authors: Layek Siddhartha Shankar , Kanani Shrushti , Doultani Shilpa , Gohil Tejas , Patil Sanket , Sudhakar Ananthasayanam , Raval Kathan Banubhai , Kuppusamy Karuppanasamy , Gorani Sanjay , Raj Sudharson , Sangameshwari Rafiya , Jadeja Himali , P. Mini Mol
Published: July 2024

A commonly accepted standard protocol for noninvasive techniques for the genetic evaluation of an embryo remains elusive due to inconclusiveness regarding the volume of spent media to be acquired and the possibility of acquiring the same for subsequent analysis. Single embryo culture is imperative for standardizing noninvasive preimplantation testing using cell-free DNA (cf-DNA) released by individual developing embryos. This study aims to compare the development dynamics of single-drop embryonic culture against with group embryonic culture to establish a standardized protocol for noninvasive Preimplantation Genetic Testing (PGT) in bovine. A total of 239 cumulus–oocyte complexes were aspirated and subjected to in vitro maturation and fertilization. Among these, 120 embryos of day 3 were transferred to single-drop culture until the blastocyst stage. The single-drop culture drops were prepared using microdrops of 30 μL. At the blastocyst stage, spent media from all single-drop embryos were utilized for extracting cell-free genomic DNA to standardize the protocol. The blastocyst rate indicates no significant difference between the two culture methods, suggesting that single-drop culture is suitable for the process. Additionally, the extracted spent media yielded sufficient quantities of cf-DNA, supporting its potential use for PGT (p < 0.05). These findings support the hypothesis that single-drop embryo culture is a viable method for cf-DNA extraction and confirm the potential of using DNA fragments from spent media as a reliable source for noninvasive PGT.
Artificial Intelligence, the Production of Scientific Texts, and the Implications for Sleep Science: Exploring Emerging Paradigms and Perspectives
Authors: Cavalcante-Silva Vanessa , D'Almeida Vânia , Tufik Sergio , Andersen Monica L.
Published: July 2024

The emergence of artificial intelligence (AI) has revolutionized many fields, including natural language processing, and marks a potential paradigm shift in the way we evaluate knowledge. One significant innovation in this area is ChatGPT, a large language model based on the GPT-3.5 architecture created by OpenAI, with one of its main aims being to aid in general text writing, including scientific texts. Here, we highlight the challenges and opportunities related to using generative AI and discuss both the benefits of its use, such as saving time by streamlining the writing process and reducing the amount of time spent on mundane tasks, and the potential drawbacks, including concerns regarding the accuracy and reliability of the information generated and its ethical use. In respect of both education and the writing of scientific texts, clear rules and objectives and institutional principles must be established for the use of AI. We also consider the positive and negative effects of the use of AI technologies on interpersonal interactions and behavior, and, as sleep scientists, its potential impacts on sleep. Striking a balance between the benefits and potential drawbacks of integrating AI into society demands ongoing research by experts, the wide dissemination of the scientific results, as well as continued public discourse on the subject.