bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of H–π and CH–O structures of the 1:1 methanol-benzene complex using matrix isolation infrared spectroscopy
Authors: Amicangelo Jay C. , Romano Natalie C. , Demay Geoffrey R. , Campbell Ian E. , Wilkins Joshua D.
Published: September 2024

Matrix isolation infrared spectroscopy was used to characterize a 1:1 complex of methanol (CH3OH) and benzene (C6H6). Co-deposition experiments with CH3OH and C6H6 were performed at 17–20 K using nitrogen and argon as the matrix gases. Several new infrared peaks in the co-deposition spectra were observed near the fundamental absorptions of the CH3OH and C6H6 parent molecules and these new peaks have been attributed to CH3OH–C6H6 complexe. Experiments were also performed with isotopic CD3OD and C6D6 and the corresponding infrared peaks of the isotopologue complexes have also been observed. Theoretical calculations were performed for the CH3OH–C6H6 complex using the M06-2X, ωB97X-D, MP2, and CCSD(T) methods with the aug-cc-pVDZ and aug-cc-pVTZ basis sets. Full geometry optimizations followed by vibrational frequency calculations were performed for several initial starting geometries and three stable minima were found for the CH3OH–C6H6 complex. The first has the CH3OH above the C6H6 ring with the OH hydrogen interacting with the π cloud of the ring (H–π complex), the second has the CH3OH above the C6H6 ring with the OH oxygen interacting with one or two of the C–H bonds of the ring (CH–O 1 complex), and the third has the CH3OH towards the side of the C6H6 ring with the OH oxygen interacting with two of the C–H bonds of the ring (CH–O 2 complex). The H–π complex structure is predicted to be the lower energy structure by ∼8 kJ/mol compared to the two CH–O structures. Comparing the theoretically predicted infrared spectra for the optimized CH3OH–C6H6 complex structures to the experimentally observed infrared peaks in argon and nitrogen matrices, it is concluded that in the argon matrices only the H–π complex structure is being observed, whereas in the nitrogen matrices the H–π complex and CH–O 1 complex structures are being observed.
Size distribution of helium droplets in the condensation regime of a pulsed beam
Authors: Iguchi A. , Hirota A. , Menk S. , Yamaguchi T. , Tanuma H. , Harries J. R. , Kuma S. , Azuma T.
Published: September 2024

We determined the size distribution of helium droplets produced in a pulsed beam in the condensation regime from the gas phase. Following electron-impact ionization, the mass-to-charge ratios of the positively charged droplets were determined by measuring their kinetic energies and velocities using an electrostatic cylindrical deflector setup. Over a range of different source conditions, we observed bimodal velocity distributions and log-normal size distributions. Our results are similar to those reported for continuous beams, but with mean sizes larger by a factor of around 100. The log-normal size distributions reported here differ strongly from the exponential distributions recently reported for a pulsed beam produced using a different nozzle design.
High-resolution electronic spectroscopy of buffer-gas-cooled metal-phthalocyanines
Authors: Miyamoto Yuki , Baba Masaaki , Enomoto Katsunari , Hiramoto Ayami , Iwakuni Kana , Kuma Susumu
Published: September 2024

High-resolution absorption spectra of the S1←S0000 transition of buffer-gas-cooled magnesium-phthalocyanine, zinc-phthalocyanine, and chloroaluminum-phthalocyanine are presented. The low temperature achieved through buffer gas cooling allowed the observation of a partially resolved rotational structure in each spectrum. We compare these structures with the previously observed high-resolution spectrum of free-base phthalocyanine. Despite the similar molecular structures of these molecules, the spectral characteristics of the rotational envelope vary depending on the individual molecular structures.
A robust time-delay selection criterion applied to convergent cross mapping
Authors: Martin R. S. , Greve C. M. , Huerta C. E. , Wong A. S. , Koo J. W. , Eckhardt D. Q.
Published: September 2024

This work presents a heuristic for the selection of a time delay based on optimizing the global maximum of mutual information in orthonormal coordinates for embedding a dynamical system. This criterion is demonstrated to be more robust compared to methods that utilize a local minimum, as the global maximum is guaranteed to exist in the proposed coordinate system for any dynamical system. By contrast, methods using local minima can be ill-posed as a local minimum can be difficult to identify in the presence of noise or may simply not exist. The performance of the global maximum and local minimum methods are compared in the context of causality detection using convergent cross mapping using both a noisy Lorenz system and experimental data from an oscillating plasma source. The proposed heuristic for time lag selection is shown to be more consistent in the presence of noise and closer to an optimal uniform time lag selection.
Design of a Thomson scattering diagnostic for the SMall Aspect Ratio Tokamak (SMART)
Authors: Kaur M. , Diallo A. , LeBlanc B. , Segado-Fernandez J. , Viezzer E. , Huxford R. B. , Mancini A. , Cruz-Zabala D. J. , Podesta M. , Berkery J. W. , Garcia-Muñoz M.
Published: September 2024

We describe the design of a Thomson scattering (TS) diagnostic to be used on the SMall Aspect Ratio Tokamak (SMART). SMART is a spherical tokamak being commissioned in Spain that aims to explore positive triangularity and negative triangularity plasma scenarios at a low aspect ratio. The SMART TS diagnostic is designed to operate at high spatial resolution, 6 mm scattering length in the low-field side and 9 mm in the high-field side regions, and a wide dynamic range, electron temperature from 1 eV to 1 keV and density from 5×1018m−3 to 1×1020m−3, to resolve large gradients formed at the plasma edge and in the scrape-off layer (SOL) under different triangularities and low aspect ratios. A 2 J @1064 nm laser will be used that is capable of operating in the burst mode at 1, 2, and 4 kHz to investigate fast phenomena and at 30 Hz to study 1 s (or more) long discharges. The scattered light will be collected over an angular range of 60° – 120° from 28 spatial points in the midplane covering the entire plasma width and the outer midplane SOL. Each scattering signal will be spectrally resolved on five wavelength channels of a polychromator to obtain the electron temperature measurement. We will also present a method to monitor in situ laser alignment in the core during calibrations and plasma operations.
Damped perturbations in inviscid shear flows: Non-resonant Landau damping in stable inflectional flows
Authors: Polyachenko E. V. , Shukhman I. G.
Published: September 2024

We analyze the dynamics of small two-dimensional disturbances in stable plane-parallel inviscid shear flows under linear theory. Using a velocity profile Vx=U(y) with an inflection point but stable according to Fjørtoft's theorem, we illustrate that the continuum spectrum of van Kampen modes, possessing real phase velocities c=ω/k, aggregates into Landau damping solutions or “quasi-modes,” which exhibit exponential decay. It was found that the real part of the complex phase velocity cL(k) of these solutions may lie outside the allowable range for van Kampen modes, suggesting a non-resonant damping mechanism for these quasi-modes. This conclusion was reached by solving the eigenvalue problem and observing the evolution of initial perturbations, calculated by directly solving the evolutionary equation for vorticity as well as by decomposing the initial disturbance into van Kampen modes. Landau damping of the total vorticity across the channel emerges as an intermediate stage before transitioning to power-law damping.
Influence of operating parameters on interphase forces in a spiral-vane-type multiphase pump
Authors: Wen Haigang , Wu Jiayi , Shi Guangtai , Qin Hao , Tao Sijia , Zeng Jie
Published: September 2024

To explore the gas–liquid interaction processes in a spiral-vane-type multiphase pump, the influence of the operating parameters on the interaction forces between the two flow phases was studied. The results show that the gas–liquid interaction forces in the impeller domain of the spiral-vane-type pump are significantly stronger than those in the diffuser domain. Specifically, the drag is four orders of magnitude greater than the lift and the virtual-mass force, and the turbulent dispersion force is the smallest. The inlet gas volume fraction (IGVF) of the multiphase pump was found to have little effect on the drag near the hub, and the effect is greater near the shroud. Increasing the IGVF was found to increase the proportions of lift and virtual-mass force in the multiphase pump to varying degrees, while the turbulent dispersion force remained almost unaffected. The influence of the rotational speed on the gas–liquid interphase forces in the multiphase pump mainly occurs in the impeller domain, and the specific performance of each force varies greatly with the axial position.
Design and implementation of a new apparatus for astrochemistry: Kinetic measurements of the CH + OCS reaction and frequency comb spectroscopy in a cold uniform supersonic flow
Authors: Lucas Daniel I. , Guillaume Théo , Heard Dwayne E. , Lehman Julia H.
Published: September 2024

We present the development of a new astrochemical research tool, HILTRAC, the Highly Instrumented Low Temperature ReAction Chamber. The instrument is based on a pulsed form of the CRESU (Cinétique de Réaction en Écoulement Supersonique Uniforme, meaning reaction kinetics in a uniform supersonic flow) apparatus, with the aim of collecting kinetics and spectroscopic information on gas phase chemical reactions important in interstellar space or planetary atmospheres. We discuss the apparatus design and its flexibility, the implementation of pulsed laser photolysis followed by laser induced fluorescence, and the first implementation of direct infrared frequency comb spectroscopy (DFCS) coupled to the uniform supersonic flow. Achievable flow temperatures range from 32(3) to 111(9) K, characterizing a total of five Laval nozzles for use with N2 and Ar buffer gases by impact pressure measurements. These results were further validated using LIF and direct frequency comb spectroscopy measurements of the CH radical and OCS, respectively. Spectroscopic constants and linelists for OCS are reported for the 1001 band near 2890–2940 cm−1 for both OC32S and OC34S, measured using DFCS. Additional peaks in the spectrum are tentatively assigned to the OCS-Ar complex. The first reaction rate coefficients for the CH + OCS reaction measured between 32(3) and 58(5) K are reported. The reaction rate coefficient at 32(3) K was measured to be 3.9(4) × 10−10 cm3 molecule−1 s−1 and the reaction was found to exhibit no observable temperature dependence over this low temperature range.
Trapping and detrapping of electrons in a typical DC glow discharge plasma under double layer condition
Authors: Singh Thangjam Rishikanta , Kommuguri Sneha Latha , Sinha Suraj Kumar
Published: September 2024

Observation of a dip in plasma density with the rise of ion plasma waves demonstrates the process of detrapping electrons under the double-layer conditions in a DC glow discharge plasma. This study presents an experimental observation of self-excitation and interplay between electron and ion plasma waves when a high positive DC voltage (Vp∼+100 V) is applied to a planar probe immersed in plasma. For lower voltages (Vp∼+5 V), the electron sheath forms on the surface of the probe; however, for sufficiently high applied voltage, plasma could not supply the sufficient number of electrons to shield it from penetrating deep into the plasma. Therefore, the electron-deficient sheath attracts plasma electrons toward the probe, resulting in the excitation of plasma waves and the formation of double layers. Low energy streaming electrons get trapped in the double layers potential step. On ionization of background neutrals, trapped electrons get detrapped. It results in the excitation of ion waves and damping of electron plasma waves. The wavelet analysis of the observed floating potential fluctuations exhibits the interplay between electron and ion plasma waves. The trapping of electrons causes the excitation of electron plasma waves, and detrapping results in the excitation of ion plasma waves as overall electron density dips. It provides new insight into the nonlinear effects of the wave–wave interaction, the onset of Buneman instability, and streaming instability under the double-layer condition.
Influence of arch lattice-shell hood length on micro-pressure waves at portal of a high-speed maglev tunnel
Authors: Zhang Jie , Guo Bingjun , Wang Yuge , Chen Xiaodong , Liu Tanghong
Published: September 2024

The considerable increase in train velocity has intensified mutual aerodynamic effects between a train and a tunnel. How to effectively reduce the micro-pressure wave (MPW) amplitude at the high-speed railway tunnel exit is significantly important and has been recognized as an extremely challenging study, especially for the high-speed maglev tunnel when the train travels through it at 400 km/h or even more. To effectively mitigate the phenomenon of “sound explosion” caused by micro-pressure waves, this study provided a newly novel solution to mitigate the micro-pressure wave amplitude, which breaks up the traditional design idea and introduces a completely new arch lattice-shell structure inside the tunnel hood. In addition, the effect of the arch lattice-shell length on initial compression waves at high-speed maglev tunnel entrance and MPWs at exit were analyzed. The findings indicate that compared to the typical section-expanded tunnel hood, the new section-expanded lattice-shell hoods have a positive effect on the mitigation of micro-pressure waves emitted at the high-speed maglev tunnel exit. As the hood length increases, the alleviating effect is strengthened, resulting in a substantial decrease in the peak of the pressure gradient (Pg) and amplitudes of MPWs. When the section-expanded lattice-shell hoods are 50, 80, and 100 m in length, the pressure gradient peaks (Pg) are decreased by 6.2%, 34.9%, and 41.8%, respectively, while the corresponding amplitudes of MPWs are reduced by 9.4%, 46.8%, and 51.9%, respectively. Therefore, the new arch lattice-shell structure added inside the section-expanded tunnel hood can significantly mitigate the amplitudes of MPWs, which provides a newly novel solution for the tunnel hood design during the high-speed train passing through the tunnel at a higher speed.
Epidemic spreading on mixing group with face-to-face interaction
Authors: Gu Wenbin , Li Wenjie , Gao Feng , Su Sheng , Zhang Zengping , Liu Xiaoyang , Wang Wei
Published: September 2024

The mixing groups gathered in the enclosed space form a complex contact network due to face-to-face interaction, which affects the status and role of different groups in social communication. The intricacies of epidemic spreading in mixing groups are intrinsically complicated. Multiple interactions and transmission add to the difficulties of understanding and forecasting the spread of infectious diseases in mixing groups. Despite the critical relevance of face-to-face interactions in real-world situations, there is a significant lack of comprehensive study addressing the unique issues of mixed groups, particularly those with complex face-to-face interactions. We introduce a novel model employing an agent-based approach to elucidate the nuances of face-to-face interactions within mixing groups. In this paper, we apply a susceptible-infected-susceptible process to mixing groups and integrate a temporal network within a specified time window to distinguish between individual movement patterns and epidemic spreading dynamics. Our findings highlight the significant impact of both the relative size of mixing groups and the groups’ mixing patterns on the trajectory of disease spread within the mixing groups. When group sizes differ significantly, high inter-group contact preference limits disease spread. However, if the minority reduces their intra-group preferences while the majority maintains high inter-group contact, disease spread increases. In balanced group sizes, high intra-group contact preferences can limit transmission, but asymmetrically reducing any group’s intra-group preference can lead to increased spread.
Analytical study of electroosmotically driven shear-thinning flow in a non-uniform wavy microchannel
Authors: Parida Sumanta Kumar , Sutradhar Abhijit , Deb Dipanwita , Dev Apul N.
Published: September 2024

An efficient mathematical model of electroosmotic blood flow in a non-uniform wavy microvessel is investigated. In the present study, the microvessel is considered as an impermeable microchannel in which the Herschel–Bulkley (H–B) model of shear-thinning character is chosen to represent the complex flow of blood. An external electric field is applied along the channel length. Due to the negative charge of the glycocalyx layer located at the inner surface of the microchannel, an electric double layer is formed. As a result, an electric potential developed, which is described by the Poisson–Boltzmann equation. Eventually, the study analytically solves a boundary value problem to determine the axial velocity of H–B fluid flow by employing a long wavelength and low Reynolds number. Additionally, the analysis derives the volumetric flow rate in the microchannel across a single wavelength and stream function for the flow field. Using Mathematica symbolic software, graphs are plotted to visualize the impact of rheological features on the axial velocity, streamlines, and volumetric flow rate concerning various physical parameters such as H–B shear-thinning flow index, plug radius, Debye length, and Helmholtz–Smoluchowski velocity. It is found that the flow of blood becomes smoother as blood behaves more shear-thinning in nature, which is the key innovation of this work. Also, an increment in Debye length helps in increasing the size of fluid bolus remarkably, which adds the novelty of physics to this study. Such a model can have applications in canalicular flow, transport in human skin, fluid dialysis, and separation methods.
The role of environmental factors on beta diversity of periphytic algae in a tropical reservoir
Authors: do Nascimento Filho Silvano Lima , Silva Diniz Anamaria , do Nascimento Moura Ariadne
Published: September 2024

Context Understanding the effects of environmental filters on the beta diversity of periphytic algae is fundamental to understanding the functioning of tropical reservoirs. Aim To investigate how the presence and morphological complexity of macrophytes drives the increase in beta diversity of periphytic algae and whether environmental filters have direct effects on periphytic algae. Methods Periphytic algae were collected from macrophyte stands quarterly in the Jazigo reservoir, north-eastern Brazil. Alpha and beta diversity were measured between the different structural complexities of macrophytes. Key results Alpha and beta diversity, and turnover of periphytic algae were higher in macrophytes of higher complexity (Pontederia crassipes and Ludwigia helminthorrhiza) and nestedness was higher in macrophytes of lower complexity (Cyperus articulatus). Beta diversity was driven primarily by physical and chemical variables. Dissolved inorganic nitrogen, macrophyte complexity, temperature, macroinvertebrates, light and dissolved oxygen explained the beta diversity of periphytic algae. Conclusions These results suggest that environmental filters and the structural complexity of macrophytes are determinants for the increase in alpha and beta diversity of periphytic algae. Macrophytes with greater morphological complexity favour increased availability of niches and microhabitats, and greater diversity of periphytic algae. Implications Habitat simplification is one of the main threats to reducing biodiversity and homogenisation of aquatic communities.
Time-resolved NMR detection of prolyl-hydroxylation in intrinsically disordered region of HIF-1α
Authors: He Wenguang , Gasmi-Seabrook Geneviève M. C. , Ikura Mitsuhiko , Lee Jeffrey E. , Ohh Michael
Published: September 2024

Prolyl-hydroxylation is an oxygen-dependent posttranslational modification (PTM) that is known to regulate fibril formation of collagenous proteins and modulate cellular expression of hypoxia-inducible factor (HIF) α subunits. However, our understanding of this important but relatively rare PTM has remained incomplete due to the lack of biophysical methodologies that can directly measure multiple prolyl-hydroxylation events within intrinsically disordered proteins. Here, we describe a real-time
13
C-direct detection NMR-based assay for studying the hydroxylation of two evolutionarily conserved prolines (P402 and P564) simultaneously in the intrinsically disordered oxygen-dependent degradation domain of hypoxic-inducible factor 1α by exploiting the “proton-less” nature of prolines. We show unambiguously that P564 is rapidly hydroxylated in a time-resolved manner while P402 hydroxylation lags significantly behind that of P564. The differential hydroxylation rate was negligibly influenced by the binding affinity to prolyl-hydroxylase enzyme, but rather by the surrounding amino acid composition, particularly the conserved tyrosine residue at the +1 position to P564. These findings support the unanticipated notion that the evolutionarily conserved P402 seemingly has a minimal impact in normal oxygen-sensing pathway.
A hybrid method for fault diagnosis of rolling bearings
Authors: He Yuchen , Fang Husheng , Luo Jiqing , Pang Pengfei , Yin Qin
Published: September 2024

Traditional diagnostic methods often have insufficient accuracy and noise reduction, which leads to diagnostic errors. To address these issues, this paper proposes an advanced fault diagnosis model that combines the variational mode decomposition (VMD) improved by a Variable-Objective Search Whale Optimization Algorithm (VSWOA) with a Pelican Optimization (PO)-boosted Kernel Extreme Learning Machine (KELM) algorithm. The application of the method is shown here in the fault diagnosis of rolling bearings. The proposed VSWOA enhances the performance of VMD by incorporating a Sobol sequence, nonlinear time-varying factors, a multi-objective initial search strategy, and an elite Cauchy chaos mutation strategy, significantly improving noise reduction in vibration signals. Fault information is precisely extracted using waveform factors, sample entropy, and advanced composite multiscale fuzzy entropy, which enables effective feature screening and dimensionality reduction. The POA fine-tunes the KELM parameters, increasing the classification accuracy. The effectiveness of the model is verified through experimental evaluations using bearing data with injected Gaussian noise (from Case Western Reserve University) and the SpectraQuest datasets, where significant improvements in noise reduction and fault detection accuracy are achieved.
Weightlessness in a bottle
Authors: Hughes Stephen
Published: September 2024

A simple method of demonstrating apparent weightlessness in free fall is described. The Apollo 15 hammer and feather drop experiment can be recreated in the classroom using a book to shield the feather from air resistance. Plastic toys and a feather thrown together in a plastic bottle can be used to recreate an apparent weightless environment close to the surface of the Earth. Since the bottle follows a parabolic trajectory, the objects within also follow a parabolic path and are seen to float as if in a space ship in orbit around the Earth. This demonstration is useful for demonstrating to students that apparent weightlessness is not confined to outer space. The use of toy fish in the experiments makes a connection with the neutral buoyancy training of astronauts. The experiments also exemplify Newton’s second law that force is mass times acceleration.
A simple and rigorous method of modal and nonmodal linear stability analysis of Hagen-Poiseuille laminar flow in pipe
Authors: Macháček Martin
Published: September 2024

This paper describes a simple spectral method of examining both modal and nonmodal stability of the laminar flow in cylindrical pipes. In particular, we present a rigorous method to find whether a perturbation of linearly stable laminar flow is also nonmodally stable, i.e., does not temporarily grow before its final exponential decay. We also discuss possible scenarios of intermittency in nonmodally unstable cases and the reason why stability persists for larger values of Reynolds number

R

if perturbations are very small.

Using an orthonormal basis of eigenfunctions of the Leray projection of Laplace operator we transform the Navier–Stokes equation (NSE) into a simple dynamical system, present a finite analytical expression for the elements of the matrix M of the linear approximation d
Δ
v/dt = M
Δ
v around its laminar solution and show that the physical meaning of these elements corresponds to energy flow to each perturbation mode from other modes and from the laminar flow. All the analytical results presented in this paper are mathematically rigorous consequences of NSE.

In sections 5 and 6 we also discuss some pilot numerical results that are tabulated in full in the supplementary material to this paper. These results support the assumption that the eigenvalues of M have negative real parts, that for large

R

matrix M is strongly nonnormal and that the nonmodal instability occurs for moderate values of

R

. The full numerical results as well as the source program and its detailed documentation are in the supplementary material of this paper.
A Mathematical Aspect of Bloch’s Theorem
Authors: Li Yan , Yang Bin , Zhou Aihui
Published: September 2024

In this paper, by studying a class of 1-D Sturm-Liouville problems with periodic coefficients, we show and classify the solutions of periodic Schrödinger equations in a multidimensional case, which tells that not all the solutions are Bloch solutions. In addition, we also provide several properties of the solutions and quasimomenta and illustrate the relationship between bounded solutions and Bloch solutions.
Hot carrier cooling in lead halide perovskites probed by two-pulse photovoltage correlation spectroscopy
Authors: Huang 黄 Yuqing 玉清 , Guo 郭 Chaoyu 钞宇 , Gao 高 Lei 蕾 , Du 杜 Wenna 文娜 , Zheng 郑 Haotian 浩天 , Wu 吴 Da 达 , Zhao 赵 Zhengpu 正朴 , Zhang 张 Chu-Wei 楚惟 , Wang 王 Qin 钦 , Liu 刘 Xin-Feng 新风 , Yan 严 Qingfeng 清峰 , Jiang 江 Ying 颖
Published: September 2024

The next-generation hot-carrier solar cells, which can overcome the Shockley–Queisser limit by harvesting excess energy from hot carriers, are receiving increasing attention. Lead halide perovskite (LHP) materials are considered as promising candidates due to their exceptional photovoltaic properties, good stability and low cost. The cooling rate of hot carriers is a key parameter influencing the performance of hot-carrier solar cells. In this work, we successfully detected hot carrier dynamics in operando LHP devices using the two-pulse photovoltage correlation technique. To enhance the signal-to-noise ratio, we applied the delay-time modulation method instead of the traditional power modulation. This advancement allowed us to detect the intraband hot carrier cooling time for the organic LHP CH3NH3PbBr3, which is as short as 0.21 ps. In comparison, the inorganic Cs-based LHP CsPbBr3 exhibited a longer cooling time of around 0.59 ps due to different phonon contributions. These results provide us new insights into the optimal design of hot-carrier solar cells and highlight the potential of LHP materials in advancing solar cell technology.
Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates
Authors: Rodrigues Leonarde N. , Inoch Wesley F. , Gomes Marcos L. F. , Couto Jr. Odilon D. D. , Archanjo Bráulio S. , Ferreira Sukarno O.
Published: September 2024

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro- and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV) is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.
Preface: Proceedings of International Conference on Thermofluids and Manufacturing Science 2024
Authors: Sahu Debjyoti , Guha Spandan , Muduli Kamalakanta
Published: September 2024

The comprehensive study of heat transfer, fluid dynamics, thermodynamics, and combustion is known as thermofluids. In the field of thermofluid, researchers, scientists, and engineers are conducting cutting-edge study theoretically and experimentally. This field seeks to create energy from sustainable resources and use it as efficiently as possible in order to make the planet carbon neutral. Apart from energy generation and transportation the manufacturing sector must utilize the resources optimally so that the sustainability is achieved while maintaining progress. Due to recent advancements in manufacturing technology, industry can now produce and transport equipment at a higher volume while emitting less CO2. Different perspectives of sustainable growth must converge in the future in order to improve the living conditions on this planet. KIIT ICTMS 2024 was a platform for showcasing multidisciplinary and interdisciplinary research happening to tackle various challenges faced by the researchers and industry. Throughout these two days, a variety of presentations, lab visits, and demonstrations took place. Industry representatives from COMSOL Multiphysics and LINSEIS Thermal Analysis attended the function.

The Kalinga Institute of Industrial Technology, located in Bhubaneswar, India, hosted the International Conference on Thermofluids and Manufacturing Science (ICTMS 2024) from March 7-8, 2024. Situated in Bhubaneswar, in the Indian state of Odisha, KIIT Deemed to be University is a university aspiring to maintain sustainability by reducing carbon footprint. This esteemed private institution in India enrolls students from 65 different nations. It has received an A++ accreditation from the University Grants Commission of India’s NAAC. The Government of India’s NIRF has KIIT Deemed to be University placed sixteenth. KIIT Mechanical Engineering School was founded in 1997. The school’s R&D projects are funded by a number of corporations and government agencies in India, including ARDB, BRNS, AICTE, and DST. Even this conference is partly sponsored by Anusandhan National Research Foundation (ANRF), Govt. of India by sanction order SSY/2024/000044. Organizers acknowledge the contribution.

List of Organizing Committee members, International Advisory Committee members and National Scientific Committee members are available in this Pdf.
Numerical Investigation on Vortex Tube as a Potential Device for Carbon Dioxide Separation
Authors: Tripathi Aditya , Bej Nilotpala , Bihari Harichandan Atal
Published: September 2024

The exponential industrialization and growing population result constantly increasing the amount of carbon dioxide in the atmosphere. Carbon dioxide is also considered to be a major contributor to rising atmospheric temperatures and pollution in air. This study aims to reduce the amount of carbon dioxide in the environment by utilising gas separation via a vortex tube. Furthermore, gas separation using a vortex tube is still a relatively unexplored and intriguing research area. Throughout the research, we conducted extensive research on the topic using CFD simulations of our self-designed vortex tube. In this study, the plots of the molar concentrations of CO2 and N2 were plotted to verify the separation of CO2 within a vortex tube.
Experimental study: Impact of hydrogen on the operational performance and emission morphology of a mono-cylinder IC-Engine
Authors: Panda Sunita , Kumar Dewangan Akhilesh , Kumar Rout Akshay
Published: September 2024

The escalating impact of fossil fuel emissions on global pollution levels has heightened the imperative to explore alternative solutions. Among numerous alternative fuels, hydrogen has emerged as the most promising option due to its characteristic of producing zero carbon emissions when compared to conventional petroleum-based fuel. The blending of hydrogen with diesel in a compression ignition (CI) engine is a concept that has been explored as a means to improve combustion efficiency, reduce emissions, and potentially enhance the overall performance of internal combustion engines. This combination is often referred to as hydrogen-diesel dual fuel or hydrogen-diesel co-fuel. Hydrogen has a high energy content per unit mass, and its combustion produces only water vapour as a by-product, making it a cleaner fuel compared to traditional hydrocarbons. High flame speed and wide flammability range lead to more efficient combustion when combined with diesel. This advantage positions hydrogen as a frontrunner in mitigating the environmental impact of transportation and energy production, offering a cleaner and more sustainable energy source for the future. In this paper, an experiment study was conducted on a single-cylinder diesel engine to compare the performance and emission parameters of plain diesel with that of diesel & hydrogen blend at a varying hydrogen concentration from 4 L/M to 24 L/M with multiples of four. From the experimental analysis, it is found that brake thermal efficiency increases by 30.825 % at a lower flow rate of hydrogen 4 l/min while the specific fuel consumption decreases as the hydrogen flow rate increases. Similarly, there is a decrease in CO, CO2 and UHC emissions compared to fossil fuel while the NOx emission is found to be increased.
Synthesis, characterization and modification of cost-effective kaolin supported hydrothermally fabricated mesoporous silica membrane
Authors: Chowdhury Zinnia , Samrat Sk , Barma Sanjib
Published: September 2024

Membrane technology has established its noteworthy footsteps in diverse fields due to its better performance efficacy, low space requirement and environment friendly properties. Among several areas of applications, membrane technology has immense application in wastewater treatment. Membrane, more specifically ceramic membrane with the modulation of hydrophilicity may open a key for effective treatment of wastewater at lower cost. Kaolin is one of the cost-effective and effective ceramic materials that can be applied for fabricating lower cost ceramic membrane support. To enhance the hydrophillicity and pore size of kaoline membrane, various researchers has coated the surface of kaoline support with different hydrophilic materials. This paper describes the synthesis and characterization for hydrothermally fabricated mesoporous silica membrane on kaolin support. The membranes were coated multiple times to reduce the surface pore size and characterized by using porosity measurement, and pure water flux analysis. The studies showed that coating was effective in reducing pore size of the membrane.
Improving manufacturing sustainability and productivity in joining thick stainless steel components through activated-TIG welding using SiO2 and TiO2 binary flux
Authors: Saha Suman , Chandra Paul Bashab , Das Santanu
Published: September 2024

Joining thicker components using conventional arc welding processes requires edge preparation and multiple passes for completely filling the root gap. Multiple passes not only increase the overall welding time but also increase the energy expenditure forcing the process to deviate from sustainable one. Multiple arc-heating cycles are also associated with broader heat affected zone (HAZ), severely affected microstructural changes, undesired residual stresses, and higher distortion. Activated TIG (A-TIG) welding process is one variant of conventional TIG welding that can fetch deeper penetration through arc constriction. Accordingly, A-TIG welding has the potential of reducing heating cycles for joining components thicker than 3.0 - 3.5mm. This article investigates the scope of reducing the heating cycles using silica-titania binary flux based A-TIG welding for square-edge butt joining of 10 mm thick stainless steel plates. Regardless of the restriction on accessibility of one face of the components, complete joining of 10 mm thick plates using only conventional TIG welding requires as much as five heating cycles. Application of A-TIG welding can complete the same task within just two heating cycles. Therefore, A-TIG welding is not only a productive process for joining thicker plates but also a sustainable and energy efficient technique.
A review of recent studies on the adoption of electric vehicles to reduce carbon emissions
Authors: Mathew Navin , Varaprasad G
Published: September 2024

Environmental hazards and climate change are serious concerns for humans, animals, and nature at present. Air pollution from the emissions of transport is one of the causes of the present situation. The carbon dioxide (CO2) and other emissions from internal combustion engine vehicles worsen the air quality to a great extent. The automobile sector in India is very crucial because of the large number of vehicles in urban and rural areas. The introduction of electric vehicles (EVs) was one of the possible solutions to controlling air pollution. This study reviews the recent literature on EV adoption in India and identifies the factors affecting the adoption. The recent articles on EV adoption are reviewed from the Web of Science and Scopus databases during 2023-2024. Financial factors, charging infrastructure, environmental concerns, social factors, etc., are the major factors identified. The identification of relevant factors affecting adoption can provide insights to manufacturers and marketers to concentrate their energies on improving adoption.
Laser Beam Welding of Inconel Alloys: A Review
Authors: Prakash Leelasai , Kumar Chandan , Gogai Debashish , Kumar Manjesh , Devi Sangjukta
Published: September 2024

In the current study, the state-of-the-art laser welding process of Inconel alloys are discussed in detail. The review work is mainly focused on the articles that describe the current status, challenges and relationship between the laser welding parameters and related outcomes in laser welding of Inconel alloys in similar and dissimilar configurations. Laser beam welding (LBW) offers precise welding methods, higher speed, and the potential to produce high-quality weld joints with lower deformation and minimal residual stresses in the welded parts. Laser welding is a complicated welding procedure having many controlling variables. But this process is stochastic in nature. Laser parameter is one of the critical variables which controls the weld quality. Inconel alloys belong to the Ni-Cr-based superalloy class acclaimed with remarkable properties such as exceptional strength, excellent fabricability, and corrosion resistance behavior. These alloys are significantly used in many industrial products such as gas turbine blades, aircraft, and marine components. The review highlights laser welding’s advantages over conventional welding technologies like arc and gas-welding. This research paper concludes with a key challenge such as process stability, material characterization, and standardization of the laser welding process for Inconel alloys and their opportunities for future research and development.
Circular Economy Maturity: How Circular are our Construction Products?
Authors: Egerter Amy , Koehler Julia , Oltean Cosmina , Hall Daniel , Thuesen Christian
Published: September 2024

The concept of circular economy (CE) has gained momentum in the construction industry to mitigate the effects of climate change and decouple economic growth from environmental impact. There is a growing body of research related to the circularity of specific construction materials, as well as to the entire building. However, there remains a lack of understanding at the construction product level, and this lack of transparency prevents informed decisions when choosing which products to use in projects and how those products support the CE. A maturity assessment is one methodology that can provide insights for both product decisionmakers and product suppliers. Maturity assessments are a way to evaluate the level of development or progress towards a certain goal, whether at the organization, project, or product level. This paper proposes a conceptual framework to assess construction product system circularity maturity. Through a systematic literature review, the authors analyze existing CE maturity assessments and CE indicators for construction products to develop the framework. The functional unit is defined as a construction product, which is defined as an integrated system with multiple materials (i.e. a prefabricated wall system). This research finds that while there are many CE assessment frameworks for the construction sector, these must be translated into a construction product context, which requires a tailored subset of circularity indicators and maturity levels. The paper proposes construction product maturity levels ranging from “initial” to “optimizing” for key circularity indicators at the construction product level, including, material procurement, manufacturing, product use phase, and end-of-life. This conceptual framework serves as a practical tool for decisionmakers and as an educational tool for suppliers on how to support the CE in construction.
Contract strategy discussions in the front-end of major public investment projects in Norway
Authors: Lædre Ola , Farid Parinaz , Engebø Atle
Published: September 2024

Since 2000, the Norwegian Ministry of Finance has implemented a state project model for large public investment projects, primarily consisting of two stages: Quality Assurance 1 (QA1) and Quality Assurance 2 (QA2). In QA1, consultants review the conceptual appraisal, including the contract strategy; in QA2, they assess the steering base. This study examines how contract strategies are addressed in the early phases of major projects under this state model, analyzing procurement approaches, contract structures, and compensation formats. The database we used contains data from 313 projects of which 229 projects had a QA2 report at the time of the study. The findings suggest that although contract structures and compensation formats are frequently discussed, procurement approaches are less scrutinized. Analysis of QA reports indicates a recurring deficiency in the depth of discussions regarding project-specific influences on contract strategy, which results in overly generic recommendations. The study underscores the need for more tailored discussions on contract strategy and the potential benefits of project-specific market surveys to enhance these strategies.
Cost and schedule performance in large government projects
Authors: Welde Morten , Engebø Atle
Published: September 2024

This paper uses data from 111 large government projects in Norway. We compare their final cost to the formal budget set by the parliament in their formal funding decision. We use standard statistical measures to illustrate their cost performance and whether the projects have been completed within the agreed schedule. We also examine the proportion of projects that have been fully successful from an operational perspective, that is, how many have been completed without either cost overruns or delays. The results are encouraging and better than most reported in the international research literature. On average, Norwegian government projects are completed 5% below budget. Three of four projects experience cost underrun. Schedule performance is weaker as the average completion is ten months after planned completion. Only about a third of the projects can be considered fully successful according to the performance targets for both time and cost. Despite these somewhat positive results, we warn against the implications of large projects currently under construction and which are experiencing challenges concerning costs and schedule.
Investigating on Combining System Dynamics and Machine Learning for Predicting Safety Performance in Construction Projects
Authors: Muntasir Nishat Mirza , Renolen Borkenhagen Ingrid , Sveen Olsen Jenni , Rauzy Antoine
Published: September 2024

This study focuses on an investigative approach to combine system dynamics and machine learning algorithms to develop an early warning system for the safety management of construction projects. As the construction industry is highly accident-prone, developing a decision-support system has always been a challenge for the research community. Therefore, 53 indicators that influence each other and the construction phase were included in the planning phase of the model. The system dynamics model was validated using extreme state and sensitivity tests, which showed reasonable trends in the number of accidents. For each simulated project, all indicator data was stored in one dataset, using two different accident rates: one for serious and one for fatal accidents. Consequently, two separate datasets were generated, one for serious accidents, which was balanced, and one for fatal accidents. Machine learning was applied to both datasets to predict safety performance. The datasets were pre-processed so that the features consisted only of data from the planning phase, with the target feature being occurrence of accident. The study revealed two key findings. First, the study showed the possibility of combining system dynamics and machine learning for safety predictions in cases where real project data is not available. Secondly, the results showed that it is possible to carry out projects with a higher risk of major accidents and provide an early warning of poor safety performance. The data set with serious accidents resulted in lower accuracy but higher recall values. However, the models struggled to identify fatal accidents as the values for the fatal accident dataset were too low. Therefore, it was discussed how other safety measurements could be more appropriate. Thus, the combination of system dynamics and machine learning has the potential to serve as a decision-support tool in construction projects and to disseminate knowledge about safety performance.