bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of rake face surface of cutting tool on tool crater wear
Authors: Fatima Anis , Wasif Muhammad , Ahmed Aqeel , Yaqoob Saima
Published: October 2023

Tool wear is complex to predict due to the intricate environment of a machining process. However, there are a confrontational effect of tool wear on the machining process in terms of deprived surface finish, reduced dimensional accuracy and increased power consumption. In this study an attempt is made to examine the effect of rake face surface of the cutting tool on tool crater wear. For this, three different types; uncoated, coated and structured rake face cutting tools were used and cutting test were performed of plain carbon steel (AISI/SAE 4140). The cutting speed of 283 m/min, feed rate of 0.1 mm/min and depth of cut of 0.1 were used. Results show, structured rake face of the cutting tool benefitted most in supressing the tool crater wear. Energy-Dispersive X-Ray analysis (EDXA) analysis confirms reduction in iron transfer on tool rake face in case of coated and structured cutting tool. Micro − hardness test was also performed and the values in case of coated and structured cutting tool was found to be suffice. This study can be a benefit for cutting difficult to cut material where crater wear formation is unavoidable.
Kognitiv-verhaltenstherapeutische Ansätze bei
Wahnüberzeugungen
Authors: Korff Samya , Lincoln Tania
Published: October 2023

Wahnüberzeugungen können das Leben massiv einschränken.
Sie sind oft mit starken negativen Emotionen verbunden, erschweren
zwischenmenschliche Kontakte und können die Betroffenen dazu bringen,
ihren Alltag ganz nach ihnen auszurichten. In den letzten Jahren haben sich
psychotherapeutische Ansätze als wesentliche Bausteine der Behandlung
erwiesen. Dieser Beitrag gibt einen Überblick über die
kognitiv-verhaltenstherapeutische Behandlung von Wahn.
Association Between Circulating Resistin Level and Preeclampsia: A
Meta-Analysis
Authors: Xu Xiangyu , Du Yi , Wang Ni
Published: October 2023

Resistin, a diminutive secretory adipokine, has been linked to obesity and its
related ailments. A growing body of evidence suggests that resistin may also be
related to the pathogenesis preeclampsia. However, results of previous studies
were not consistent. We performed a systematic review and meta-analysis to
evaluate the level of circulating resistin in women with PE. A systematic search
of Medline, Web of Science, and Embase databases from inception to April 28,
2023, was conducted to identify studies that compared blood resistin levels in
pregnant women with and without PE. A random-effects model was utilized to pool
the results, accounting for heterogeneity. The present study analyzed eighteen
datasets from sixteen observational studies. The results of the meta-analysis
demonstrated a statistically significant increase in blood resistin levels among
women with PE compared to the control group. (standardized mean
difference=0.35, 95% confidence interval: 0.16 to 0.54,
p<0.001; I2=74%). The findings of the subgroup analysis
indicate that various study characteristics, including study design, timing, and
methods for measuring resistin, matching of body mass index between cases and
controls, and study quality scores did not exert a significant impact on the
outcomes. Nonetheless, it is noteworthy that the diagnostic criteria for PE
employed in the studies included in the analysis may have influenced the results
(p for subgroup difference=0.001). Women with preeclampsia exhibit a
greater concentration of resistin in circulation when compared to healthy
pregnant controls.
Assessment of endoscope reprocessing at World Gastroenterology Organisation training centers using adenosine triphosphate testing
Authors: Visrodia Kavel , Jones Dianne , Jennings Melissa , Conway Catherine , Burgos Herbert , Malani Jioji , Ogutu Elly , Pausawasdi Nonthalee , Sabbagh Luis , Leddin Desmond , Kassmeyer Blake , Lennon Ryan J. , Topazian Mark D.
Published: October 2023

Background and study aims Adequacy of endoscope disinfection in resource-limited settings is unknown. Adenosine triphosphate (ATP) testing is useful for evaluation of endoscope reprocessing, and ATP <200 relative light units (RLUs) after manual endoscope cleaning has been associated with adequacy of endoscope disinfection.

Methods Consecutive endoscopes undergoing reprocessing at five World Gastroenterology Organisation (WGO) training centers underwent ATP testing before and after an on-site educational intervention designed to optimize reprocessing practices.

Results A total of 343 reprocessing cycles of 65 endoscopes were studied. Mean endoscope age was 5.3 years (range 1–13 years). Educational interventions, based on direct observation of endoscope reprocessing practices at each site, included refinements in pre-cleaning, manual cleaning, high-level disinfection, and endoscope drying and storage. The percentage of reprocessing cycles with post-manual cleaning ATP ≧200 decreased from 21.4% prior to educational intervention to 14.8% post-intervention (P=0.11). In multivariable logistic modelling, gastroscopes were significantly less likely (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.01–0.19; P<0.001) than colonoscopes to achieve post-manual cleaning ATP < 200. No other factor (educational intervention, study site, endoscope age) was significantly associated with improved outcomes. Endoscope ID was not significantly associated with ATP values, and sites that performed manual versus automated HLD did not have significantly different likelihood of post-manual cleaning ATP <200 (OR 1.18, 95% CI 0.56–2.50; P=0.67).

Conclusions In resource-limited settings, approximately 20% of endoscope reprocessing cycles may result in inadequate disinfection. This was not significantly improved by a comprehensive educational intervention. Alternative approaches to endoscope reprocessing are needed.
Cold snare resection for non-ampullary sporadic duodenal adenomas: systematic review and meta-analysis
Authors: Ciocirlan Mihai , Opri Diana Lavinia , Bilous Dana Maria , Leucuta Daniel-Corneliu , Tianu Elena , Vladut Catalina
Published: October 2023

Background and study aims The role of cold snare polypectomy
(CSP) in curative resection of non-ampullary sporadic duodenal adenomas (NASDA) is debated. We
conducted a systematic review and meta-analysis to investigate the efficacy and safety of CSP
for NASDA.

Patients and methods In this systematic review and meta-analysis,
we identified published series of patients with CSP for NASDA by searching PubMed and Google
Scholar, which resulted in six papers (205 lesions). The main outcome was the rate of local
remission after repeated CSP, the secondary outcomes were rates of local remission at first
control and rates for delayed bleeding and immediate perforations. We computed the weighted
summary proportions under the fixed and random effects model.

Results The pooled proportion of local remission after repeated
CSP was 88% (95% confidence interval [CI] 57%-100%). The pooled proportion of local remission
at first control was 81% (95% CI 55%-98%), the pooled proportion of delayed bleeding was 1%
(95% CI 0%-4%) and the pooled proportion of immediate perforation was 0% (95% CI
0%-2%).

Conclusions Our meta-analysis suggests that CSP should be
considered as the first-line therapy for NASDA.
Nonlinear optical feature generator for machine learning
Authors: Yildirim Mustafa , Oguz Ilker , Kaufmann Fabian , Escalé Marc Reig , Grange Rachel , Psaltis Demetri , Moser Christophe
Published: October 2023

Modern machine learning models use an ever-increasing number of parameters to train (175 × 109 parameters for GPT-3) with large datasets to achieve better performance. Optical computing has been rediscovered as a potential solution for large-scale data processing, taking advantage of linear optical accelerators that perform operations at lower power consumption. However, to achieve efficient computing with light, it remains a challenge to create and control nonlinearity optically rather than electronically. In this study, a reservoir computing approach (RC) is investigated using a 14-mm waveguide in LiNbO3 on an insulator as an optical processor to validate the benefit of optical nonlinearity. Data are encoded on the spectrum of a femtosecond pulse, which is launched into the waveguide. The output of the waveguide is a nonlinear transform of the input, enabled by optical nonlinearities. We show experimentally that a simple digital linear classifier using the output spectrum of the waveguide increases the classification accuracy of several databases by ∼10% compared to untransformed data. In comparison, a digital neural network (NN) with tens of thousands of parameters was required to achieve similar accuracy. With the ability to reduce the number of parameters by a factor of at least 20, an integrated optical RC approach can attain a performance on a par with a digital NN.
ManyHF-based full-dimensional potential energy surface development and quasi-classical dynamics for the Cl + CH3NH2 reaction
Authors: Szűcs Tímea , Czakó Gábor
Published: October 2023

A full-dimensional spin–orbit (SO)-corrected potential energy surface (PES) is developed for the Cl + CH3NH2 multi-channel system. Using the new PES, a comprehensive reaction dynamics investigation is performed for the most reactive hydrogen-abstraction reactions forming HCl + CH2NH2/CH3NH. Hartree–Fock (HF) convergence problems in the reactant region are handled by the ManyHF method, which finds the lowest-energy HF solution considering several different initial guess orbitals. The PES development is carried out with the Robosurfer program package, which iteratively improves the surface. Energy points are computed at the ManyHF-UCCSD(T)-F12a/cc-pVDZ-F12 level of theory combined with basis set (ManyHF-RMP2-F12/cc-pVTZ-F12 – ManyHF-RMP2-F12/cc-pVDZ-F12) and SO (MRCI+Q/aug-cc-pwCVDZ) corrections. Quasi-classical trajectory simulations show that the CH3-side hydrogen abstraction occurs more frequently in contrast to the NH2-side reaction. In both cases, the integral cross sections decrease with increasing collision energy (Ecoll). A reaction mechanism shifting from indirect to direct stripping can be observed from the opacity functions, scattering angle, and translation energy distributions as Ecoll increases. Initial attack angle distributions reveal that chlorine prefers to abstract hydrogen from the approached functional group. The collision-energy dependence of the product energy distributions shows that the initial translational energy mainly transfers to product recoil. The HCl vibrational and rotational energy values are comparable and nearly independent of collision energy, while the CH2NH2 and CH3NH co-products’ vibrational energy values are higher than the rotational energy values with more significant Ecoll dependence. The HCl(v = 0) rotational distributions are compared with experiment, setting the direction for future investigations.
Power unit Burr-XII distribution: Statistical inference with applications
Authors: Yıldırım Elif , Ilıkkan Eda Selin , Gemeay Ahmed M. , Makumi Nicholas , Bakr M. E. , Balogun Oluwafemi Samson
Published: October 2023

This article introduces a new statistical distribution called the power unit Burr-XII distribution, which is an extension of the Burr XII distribution obtained through a power transform. This paper investigates several statistical properties of this new model, including mode, moments, moment generating and characteristic functions, entropy, and Bonferroni and Lorenz curves. In addition, various classical estimators for the parameters of the power unit Burr-XII distribution are evaluated, including maximum likelihood estimates, ordinary least squares estimates, maximum product of interval estimates, Anderson–Darling, right and left tail Anderson–Darling, and Cramer–von Mises estimators. This study provides tables and graphs to illustrate the performance of these methods under different scenarios and sample sizes. The results of the proposed distribution in different fields of application are shown using the mortality rates of COVID-19 patients in Spain and flood data from 20 observations. As a result of both applications, it was observed that the proposed distribution gave better results compared to other well-known distributions, such as the beta distribution, transformed gamma distribution, log-weighted power distribution, transmuted power distribution, Kumaraswamy distribution, Topp–Leone distribution, exponentiated reduce Kies distribution, and exponentiated Topp–Leone distribution.
Spatiotemporal flow evolution in a rocket-based combined-cycle inlet during ejector-to-ramjet mode transition
Authors: Yang Xue , Yang Yiyan , Tian Zhaoyang , Zhang Junhua , Shi Lei
Published: October 2023

The spatiotemporal distribution characteristics and flow stability of a rocket-based combined-cycle (RBCC) inlet during the ejector-to-ramjet mode transition are investigated numerically. The operational pressure of the embedded rocket is adjusted to three different levels, and the time-sequences of the rocket and back pressure regulation are varied. The pressure in feature sections is monitored to reveal the coupling relationship and stability of the internal flowfield. The inlet is more adaptable to severe disturbances under the “throttle-maintaining” regulation and is susceptible under the “direct-shutdown” regulation. The severe fluctuation period is relatively short within “medium throttle-maintaining,” while is lengthy within the “high throttle-maintaining.” The severe fluctuation under the direct-shutdown develops with the propagation of the regulation and decays with its establishment. The ultimate flowfields driven by different time-sequences reach unanimity with the same adjustable parameters of embedded rocket and back pressure; however, the dynamic evolutions show distinct characteristics. During the mode transition, pressure “valleys” are formed in any selected sections with the rocket regulations, and “peaks” are developed in many sections due to the propagation of back pressure or the instability of the rocket jet. For the medium throttle-maintaining regulation, the effect of time-sequence on the flowfield is relatively weak. For the high throttle-maintaining regulation, the pressure disturbance rises abruptly under the rocket priority regulation, with a most severe amplitude of 100.7%. For the direct-shutdown regulation, the maximum pressure disturbance of 125% is observed within the rocket priority regulation, and the minimum disturbance occurs within the back pressure priority regulation.
Investigation of defect characterization, formation mechanism, and effect in distributed feedback lasers
Authors: Liu Lijie , An Junming , Wu Yuanda , Huang Yongguang , Zhang Ruikang , Wang Baojun , Chu Kunkun , Zhang Xiaoguang
Published: October 2023

InP, which exhibits attractive physical characteristics, such as high electron mobility, high conductivity, and high bandgap width, has always been fanatically pursued in high frequency and high speed devices in recent years. However, the inherent high density defects hinder the quality of the epitaxial layer and, even worse, impede the device’s life. Here, we found a kind of defect in the distributed feedback laser layers on an InP based substrate. A focused ion beam was employed in order to dissect the defect. The formation process was characterized using a transmission electron microscope and a high-resolution transmission electron microscope. Closer analysis reveals that defects form a subsurface damage layer between the substrate and the epitaxial layer. The subsurface damage layer already has a potentially destructive lattice, including lots of dislocations and lattice distortions, which leads to anisotropy in the interface layer. As the epitaxial film thickness increases, so does this strain relax, and dislocations form.
Task-specific motivation and development of the Spanish L2 self during domestic immersion
Authors: Jarrett Dylan , Gurzynski-Weiss Laura
Published: October 2023

The present study considers global (Dörnyei’s 2005 L2 selves) and
micro (task-specific) measures of motivation in a unique task-based context: a two-week, domestic Spanish immersion program for
high schoolers in the United States (Gurzynski-Weiss, in revision).

Data was collected from eight students via task-specific questionnaires (given after 30 tasks), L2 self
questionnaires (given at the beginning and end of a two-week program), and 12 daily reflective journals. Results indicated overall
high L2 self-constructs with little change over two weeks of instruction, and all task domains were rated moderately to very high
for task motivation. It was found that higher L2 self ratings regularly patterned with higher task-specific motivation, although
participant individual differences and characteristics unique to a domestic immersion program also influenced task-specific
motivation.
Sintering, microstructure, and mechanical properties of ZrO2-doped Al2O3
Authors: Baruah Biswajit , Anand Rahul , Behera Shantanu K.
Published: October 2023

In the present work, the effect of Zr-doping on the sintering, microstructure development, and mechanical properties of polycrystalline Al2O3 was studied. Dopant concentrations of 830 and 2070ppm cationic ratio of Zr in Al2O3 corresponding to 2000 and 5000 wt. ppm of ZrO2 in Al2O3, respectively, were used. The sintering schedule of undoped as well as Zr-doped Al2O3 samples was optimised following a series of precoarsening experiments. The Zr-doped Al2O3 ceramics exhibited controlled grain size and improved density. Upon increasing the Zr-dopant concentration from 830 cat. ppm to 2070 cat. ppm. Zr-doped Al2O3 ceramics having a refined microstructure with a homogeneous distribution of controllably grown ZrO2 in Al2O3 matrix was obtained. Microhardness of the Zr-doped samples showed negligible dependence with Zr-doping, whereas mechanical strength was found to improve with it. The improvement in strength was attributed to the combined effect of improved sinter density, microstructural refinement, and grain-boundary strengthening.
A simple electrode insulation and channel fabrication technique for high-electric field microfluidics
Authors: Anand Gaurav , Safaripour Samira , Tercovich Jaynie , Capozzi Jenna , Griffin Mark , Schin Nathan , Mirra Nicholas , Snoeyink Craig
Published: October 2023

A simple and robust electrode insulation technique that can withstand a voltage as high as

1000
V

, which is equivalent to an electric field strength of

∼

1

 MV m−1 across a

10
μ

m

channel filled with an electrolyte of conductivity

∼

0.1

 S m−1, i.e. higher than sea water’s conductivity, is introduced. A multi-dielectric layers approach is adopted to fabricate the blocked electrodes, which helps reduce the number of material defects. Dielectric insulation with an exceptional breakdown electric field strength for an electrolyte confined between electrodes can have a wide range of applications in microfluidics, like high electric field strength-based dielectrophoresis. The voltage-current characteristics are studied for various concentrations of sodium chloride solution to estimate the insulation strength of the proposed materials, and the breakdown strength is calculated at the point where the electrical insulation failed. A detailed adhesion technique is also demonstrated, which will reduce the ambiguity around the fabrication of a sealed channel using SU-8.
Electronic Kapitza conductance and related kinetic coefficients at an interface between n-type semiconductors
Authors: Meilakhs A P
Published: October 2023

We calculate the Kapitza conductance, which is the proportionality coefficient between heat flux and temperature jump at the interface, for the case of two conducting solids separated by the interface. We show that for conducting solids in a non-equilibrium state, there should also arise the electrochemical potential jump at the interface. Hence to describe linear transport at the interface we need three kinetic coefficients: interfacial analogs of electric and heat conductances and interfacial analog of the Seebeck coefficient. We calculate these coefficients for the case of an interface between n-type semiconductors. We perform calculations in the framework of Boltzmann transport theory. We have found out that the interfacial analog of the Seebeck coefficient for some range of parameters of the considered semiconductors, has a high value of about 10−3 V K−1. Thus this effect has the potential to be used for the synthesis of effective thermoelectric materials.
Covalently bridged bond assembly of MoS2 lamellae onto a graphene sheet: an outstanding electrode for high rate and long-life lithium/sodium-ion batteries
Authors: Guo Mengyuan , Zhang Huipei , Qi Luyao , Zhang Shan , Qin Yanmin , Deng Binglu
Published: October 2023

The practical application of Molybdenum sulphide (MoS2) electrodes has been hindered by its structural instability, and poor electrical conductivity. To enhance the cycle stability and rate performance of MoS2 in lithium/sodium-ion batteries (LIBs/SIBs), we synthesized a graphene-supported MoS2 composite (MoS2@rGO) with affluent covalent bridged bonds through a facile and scalable hydrothermal and annealing process. The covalent bridged bonds of Mo–S–C, Mo–O–C and C–O–S provide an effective charge transfer path between MoS2 and graphene, facilitating fast charge hopping and improving rate performance. As anode materials for LIBs, the MoS2@rGO exhibited exceptional long-term cycle life (906 mAh g−1 at 1.0 A g−1 after 400 cycles) and outstanding rate capability (1267.7/314.7 mAh g−1 at 0.1/6.5 A g−1). Additionally, the MoS2@rGO electrode demonstrated a stable reversible capacity of 521.7 mAh g−1 at 1.0 A g−1 after 700 cycles and excellent rate capabilities of 665.1 and 326.3 mAh g−1 at 0.1 and 10.0 A g−1 in SIBs. The edge Mo of MoS2 is directly coupled with the oxygen of the functional group on rGO, achieved by adjusting the pH value of the solution to tune the surface charge feature, can effectively enhance the structural stability of electrode even under higher current density.
Current–voltage characteristics of focused ion beam fabricated superconducting tungsten meanders
Authors: Kumar Abhishek , Husale Sudhir , Saravanan M P , Gajar Bikash , Yousuf Majid , Saini Abhilasha , Yadav Mahesh Gaurav , Aloysius R P
Published: October 2023

We report on the superconducting properties and intermediate resistive steps (IRS) observed in the current–voltage characteristics (IVC) of tungsten meander (MW) structures fabricated using focused ion beam (FIB) technique. Three number of MWs were studied with individual wire widths of 240 nm, 640 nm and 850 nm with superconducting transition temperatures (

T

C

) of 4.5 K, 4.55 K and 4.60 K respectively. The measured normal state resistance values at 8 K for these wires are of ∼182 kΩ, ∼49 kΩ and ∼32 kΩ, respectively as a function of increasing wire widths; are higher than the quantum of resistance (

h

/

4

e

2

=
6.45
k
Ω
,

h

is a Planck constant and

e

is electronic charge) indicating extreme disorder nature of the fabricated samples. The variation of resistance with respect to temperature (for

T
<
T

C

) follows the theoretical simulation of weak-link induced thermally activated phase slip (WL-TAPS) for the MW wire of width ∼240 nm, while for other samples the convergence between WL-TAPS and the experimental data are not so satisfactory. Though the IRS features are present in all the samples with varying degree of prominence, an external magnetic field causes its evolution demarcating different boundary lines with respect to temperatures. Herein, we believe that the occurrence of IRS is due to phase slip (PS) mechanism which further proliferates through phase slip centers or phase slip lines in IVC either with respect to temperature or magnetic field. As per our knowledge, such IRS features are not being reported for W-meander wires fabricated using FIB technique. The observation of PS (IRS) features is promising for the use of FIB fabricated W nanowires for various quantum applications including single photon detector, bolometers.
Stochastic energetics of a colloidal particle trapped in a viscoelastic bath
Authors: Darabi Farshad , Ferrer Brandon R , Gomez-Solano Juan Ruben
Published: October 2023

We investigate the statistics of the fluctuations of the energy transfer between an overdamped Brownian particle, whose motion is confined by a stationary harmonic potential, and a surrounding viscoelastic fluid at constant temperature. We derive an analytical expression for the probability density function of the energy exchanged with the fluid over a finite time interval, which implicitly involves the friction memory kernel that encodes the coupling with such a non-Markovian environment, and reduces to the well known expression for the heat distribution in a viscous fluid. We show that, while the odd moments of this distribution are zero, the even moments can be explicitly expressed in terms of the autocorrelation function of the particle position, which generally exhibits a non-mono-exponential decay when the fluid bath is viscoelastic. Our results are verified by experimental measurements for an optically-trapped colloidal bead in semidilute micellar and polymer solutions, finding and excellent agreement for all time intervals over which the energy exchange takes place.
Rule switching mechanisms in the Game of Life with synchronous and asynchronous updating policy
Authors: Miszczak Jarosław Adam
Published: October 2023

The emergence of complex structures in the systems governed by a simple set of rules is among the most fascinating aspects of Nature. The particularly powerful and versatile model suitable for investigating this phenomenon is provided by cellular automata, with the Game of Life being one of the most prominent examples. However, this simplified model can be too limiting in providing a tool for modelling real systems. To address this, we introduce and study an extended version of the Game of Life, with the dynamical process governing the rule selection at each step. We show that the introduced modification significantly alters the behaviour of the game. We also demonstrate that the choice of the synchronization policy can be used to control the trade-off between the stability and the growth in the system.
A highly birefringent photonic crystal fiber based on a central trielliptic structure: FEM analysis
Authors: Liu Zihan , Wen Jialin , Zhou Zhengyong , Dong Yuming , Yang Tianyu
Published: October 2023

In this study, a highly birefringent photonic crystal fiber (PCF) with a simple center trielliptic is presented. The finite element method is applied in this study to analyze PCF. By adjusting the ellipticity and other parameters, the fiber performances can be optimized. As the parameters of the PCF are finalized, i.e., the number of cladding N = 4, lattice constant Λ = 1.6 μm, and ellipticity η = 2, a high birefringence of 3.56 × 10−2 can be obtained at the wavelength λ = 1.55 μm . Moreover, the dispersions of the X- and Y-polarized modes are relatively flat in the range of 1 μm to 1.55 μm along with a confinement loss as low as 9.63 × 10−6 dB m−1. Besides, this structure has demonstrated remarkable robustness, maintaining its superior performance even when subjected to significant displacements or rotations. Due to the characteristics of the high birefringence and low confinement loss, this PCF can be used for long distance optical fiber communication, fiber sensing, dispersion compensation, and supercontinuum generation.
Optical solitons of the (2+1)-dimensional nonlinear Schrödinger equation with spatio-temporal dispersion in quadratic-cubic media
Authors: Zhao Ya-nan , Guo Li-feng
Published: October 2023

The major objective of this paper is to study the perturbed nonlinear Schrödinger equation with spatio-temporal dispersion in (2+1)-dimensional by using the complete discrimination system for polynomial. This paper discusses the propagation patterns in nonlinear fibers with quadratic-cubic nonlinearity. Additionally, a host of optical wave solutions are obtained, where solitary wave patterns and elliptic functions double periodic patterns are newly received. Besides, some two dimensional figures of solutions are illustrated in parameter space. All these solutions and figures are available to investigate the propagation dynamics of optical solitons in optical fibers.
A first-principles assessment of the thermoelectric properties in half-heusler compound NbIrSn
Authors: Khatri Prakash , Adhikari Narayan Prasad
Published: October 2023

Converting waste heat into electric power using thermoelectric materials could significantly address global energy needs. Half-Heusler compounds exhibit significant promise as thermoelectric materials suitable for high temperatures, thereby offering a potential solution to address the energy crisis. By employing density functional theory (DFT), semi-classical Boltzmann transport theory (BTE), and density functional perturbation theory (DFPT), this study thoroughly examines the structural, electronic, magnetic, phonon, mechanical, and thermoelectric properties of 18 valence electron half Heusler compound NbIrSn. Considering the presence of heavy 5d transition element Ir in our compound, all calculations are carried out with and without spin–orbit coupling (SOC). This material display both dynamic and mechanical stability, and also possess the property of ductility as indicated by Pugh’s ratio and Poisson’s ratio. NbIrSn is identified as non-magnetic semiconductors with indirect band gaps of 0.65 eV and it reduces to 0.63 eV when SOC is included. The different transport parameters are analyzed in relation to the chemical potential and doping concentrations for different temperatures. The lattice thermal conductivity of the material at room temperature is measured to be 13.40 Wm−1K−1 and 14.81 Wm−1K−1without and with SOC respectively. The optimal zT values for NbIrSn at 1200 K are 0.98 with p-type doping and 0.31 with n-type doping. Incorporating SOC leads to a substantial improvement, raising the optimal zT values to 1.33 for p-type doping and 0.47 for n-type doping. In conclusion, incorporating SOC is essential when analyzing the characteristics of the proposed compound. The present study highlights NbIrSn as a potentially a favorable candidate for p-type doping on high-temperature power generation.
Qudit states in noisy quantum channels
Authors: Dutta Supriyo , Banerjee Subhashish , Rani Monika
Published: October 2023

In this work, we analyze a number of noisy quantum channels on a family of qudit states. The channels studied are the dit-flip noise, phase flip noise, dit-phase flip noise, depolarizing noise, non-Markovian Amplitude Damping Channel (ADC), dephasing noise, and depolarization noise. To gauge the effect of noise, the fidelity between the original and the final states is studied. The change of coherence under the action of noisy channels is also studied, both analytically and numerically. Our approach is advantageous as it has an explicit relation to the original approach to the multi-qubit hypergraph states.
Two-dimensional extended Hubbard model: doping, next-nearest neighbor hopping and phase diagrams
Authors: Sherman A
Published: October 2023

Using the strong coupling diagram technique, we investigate the extended Hubbard model on a two-dimensional square lattice. This approach allows for charge and spin fluctuations and a short-range antiferromagnetic order at nonzero temperatures. The model features the first-order phase transition to states with alternating site occupations (SAO) at the intersite repulsion v = v

c
. In this work, we show that doping decreases v

c
. For a nonzero next-nearest neighbor hopping

t
′

, less mobile carriers produce a stronger fall in v

c
. For half-filling and

t
′
=
0

, we consider phase diagrams for a fixed temperature T, on-site U, and intersite repulsions. The diagrams contain regions of SAO, Mott insulator, and several metallic states distinguished by their densities of states. Two of them are characterized by a dip and a peak at the Fermi level. The dip originates from the Slater mechanism for itinerant electrons, while the peak to bound states of electrons with localized magnetic moments. The existence of these two metallic regions in the phase diagram is a manifestation of the Pomeranchuk effect. The boundary between these regions reveals itself as a kink in the curve v

c
(T) and as a maximum in the T dependence of the double occupancy D. Our calculated D for different values of v, U, and T are in semiquantitative agreement with Monte Carlo results.
Effective field theory of intrinsic alignments at one loop order: a comparison to dark matter simulations
Authors: Bakx Thomas , Kurita Toshiki , Elisa Chisari Nora , Vlah Zvonimir , Schmidt Fabian
Published: October 2023

We test the regime of validity of the effective field theory (EFT) of intrinsic alignments (IA) at the one-loop level by comparing with 3D halo shape statistics in N-body simulations. This model is based on the effective field theory of large-scale structure (EFT of LSS) and thus a theoretically well-motivated extension of the familiar non-linear alignment (NLA) model and the tidal-alignment-tidal-torquing (TATT) model. It contains a total of 8 free bias parameters. Specifically, we measure the dark matter halo shape-shape multipolesPEE(0)(k),PEE(2)(k),PBB(0)(k),PBB(2)(k) as well as the matter-shape multipolesPδE(0)(k),PδE(2)(k) from the simulations and perform a joint fit to determine the largest wavenumberkmaxup to which the theory predictions from the EFT of IA are consistent with the measurements. We find that the EFT of IA is able to describe intrinsic alignments of dark matter halos up tokmax= 0.30 h/Mpc atz= 0. This demonstrates a clear improvement over other existing alignment models like NLA and TATT, which are only accurate up tokmax= 0.05 h/Mpc. We examine the posterior distributions of the higher-order bias parameters, and show that their inclusion is necessary to describe intrinsic alignments in the quasi-linear regime. Further, the EFT of IA is able to accurately describe the auto-spectrum of intrinsic alignment B-modes, in contrast to the other alignment models considered.
Energy transport analysis of NSTX plasmas with the TGLF turbulent and NEO neoclassical transport models
Authors: Avdeeva G. , Thome K.E. , Smith S.P. , Battaglia D.J. , Clauser C.F. , Guttenfelder W. , Kaye S.M. , McClenaghan J. , Meneghini O. , Odstrcil T. , Staebler G.
Published: October 2023

This work presents a study of plasma transport at low aspect ratio on the National Spherical Torus Experiment tokamak, where the turbulent and neoclassical energy fluxes calculated by the quasilinear Trapped Gyro Landau Fluid (TGLF) model and the multi species drift-kinetic Neoclassical solver (NEO) are validated against experimental data. The turbulent energy transport of two plasma discharges, one in the L-mode confinement regime and another in the H-mode regime, is dominated by electrostatic drift-wave instabilities, while the ion heat transport has a significant neoclassical contribution. The data analysis workflow is described in detail to understand how the variations of mapping and fitting of experimental data affect the power balance solution and subsequent flux-matching plasma profile predictions with the TGYRO solver. On average, the predicted plasma profiles are consistent with experimental data. However, the solutions are sensitive to various input parameters, including boundary conditions, and the electron-ion coupling. Linear gyrokinetic stability analysis demonstrates close agreement of the real frequencies of unstable modes between TGLF and CGYRO gyrokinetic simulations, but higher growth rates are predicted by TGLF, especially for the H-mode case. Estimates of the low-k modes’ contributions to the total flux are consistent with linear stability analysis and the E × B suppression of turbulence in TGLF simulations with the SAT1 saturation model, while the SAT2 saturation model over-predicts the low-k modes’ contribution in the H-mode case. Moreover, the results with SAT1 model are consistent with power balance analysis, which indicates only neoclassical ion energy fluxes inside ρ < 0.4 in the L-mode case and

ρ
⩽
0.7

in the H-mode case. The presence of multi-scale turbulence and ion-scale driven zonal flow mixing effects are also observed in TGLF scans of the electron turbulent heat flux over a range of temperature gradients and the electron-ion temperature ratio, which could explain the strong model sensitivity to variations of input parameters.
A Statistical review of the dates and patterns of volcanic activity of Lewotolo Volcano, East Nusa Tenggara, Indonesia
Authors: Muliawati T , Harbowo D G
Published: October 2023

Lewotolo is a stratovolcano located on the Lembata Island, East Nusa Tenggara (Lesser Sunda Islands), Indonesia. The first geohistory of the Lewotolo volcanic eruption was recorded in 1660 (Volcanic Eruption Index (VEI) 3). Since November 11, 2020, Lewotolo has been included in the list of Indonesian volcanoes with the necessary precautions, comparable to the Anak Krakatau, Merapi, and Semeru volcanoes. We investigated Lewotolo volcanic activity by analyzing the height of the ash column data, maximum seismograph amplitude, and recorded seismic duration from November 29, 2020, to September 23, 2022, which are provided in magma.esdm.go.id. The results showed 191 records of eruption activity data, which formed three clusters for each variable using the Elbow Method in the Non-Hierarchical K-means clustering analysis. These data were plotted on the solar and Hijri lunar calendars. The data plot shows anomalies in the volcanic activity frequency and a significant pattern of activity at specific times. The data plot illustrates that the value of the activity frequency pattern tends to increase at Earth orbital events such as the December-January perihelion (up to 0.124) and June-July aphelion (up to 0.262) and at the new moon phases (up to 0.168). This phenomenon appears as solar and lunar tidal anomalies that commonly occur as gravitational sea tides. Along with the need for more comprehensive data, the results of this study may provide new perspectives for further research on the possible role of gravitational tide phenomena in volcanic activity, at least to explain the volcanic activity in Lewotolo.
Sustainable Engineered Cementitious Composite using Natural Sisal and Coir Fibers
Authors: Sembiring Suranta , Kusumaningrum Patria , Zaki Anwar F
Published: October 2023

Engineered Cementitious Concrete (ECC) or bendable concrete is a high-performance concrete (HPC) with high ductility characteristic. Generally, it has been used to strengthen or retrofit existing structures to increase structural resilience against extreme loadings such as earthquakes or blasts. The constituent materials of ECC are fine aggregates, cement, supplementary cementitious composite (silica fume, fly ash, etc.), superplasticizer, water, and the use of fibers up to 2% volume fraction. With the use of fibers and the elimination of coarse aggregate, ECC has deflection-hardening in bending and exhibits fiber-bridging by multiple cracking. However, the development of ECC has so far been limited to using only synthetic and inorganic fibers, which are scarce yet expensive in Indonesia. As Indonesia boasts the second highest level of biodiversity in the world as the source of natural fibers, in this research, the natural fibers are used to replace synthetic and inorganic fibers in making ECC more sustainable, low cost yet locally available. Not only did the natural fibers are locally available at affordable prices, but the fibers also have distinctive characteristics of sustainable materials with high tensile strength and significant elongation. From the experiments, one may be concluded that natural fibers of sisal and coir can improve the ECC flexural strength up to 39.5% of the non-fiber mix. This highlights its ability to replace synthetic and inorganic fibers in ECC mixture.
The Impact of Environmental, Social, And Economic Factors Due to Anak Krakatau Volcano Tsunami Using Remote Sensing Technology
Authors: Virtriana Riantini , Harto Agung Budi , Rohayani Pitri , Anggraini Tania Septi , Ihsan Kalingga Titon Nur
Published: October 2023

Tsunamis often occur in the territory of Indonesia because it is widely traversed by encounters between earth plates under the sea. Thus, if an earthquake occurs, it has the potential to generate a tsunami. The Indonesian region is also located in the ring of the fire area, and is the country with the highest number of active volcanoes with more than 127 events, that can encourage volcanic earthquakes. In addition, when volcanoes erupt offshore, the potential for a tsunami will be even greater because the expulsion of material can generate landslides toward the sea, causing a tsunami. The tsunami that happened in the eruption of Anak Krakatau on December 22, 2018, in the Sunda Strait, resulted in a tsunami in the Lampung and Banten areas. This study tries to compare environmental, social, and economic factors before and after the tsunami in the coastal areas of Lampung and Banten. The integration of remote sensing data will be carried out to determine environmental, social, and economic factors such as Land Cover, NDWI, NDVI, Night Light, and NO2 data. Random Forest Machine Learning will also be involved in shaping land cover models. Random Forest is often used because it has high accuracy. The results show a significant change in land cover in coastal areas and the impact of environmental, social, and economic factors. This study is expected to support the mitigation process in the event of a tsunami in the future. In addition, it is expected to be used by policymakers in planning development after the tsunami disaster.
An Enhanced Earthquake Risk Analysis using H3 Spatial Indexing
Authors: Aini A N , Dewantari O A , Mandala D P A , Bisri M B F
Published: October 2023

Risk assessment is the first step in disaster risk reduction and crucial for types of disasters with potentially significant impacts, such as earthquakes. Besides the direct impact of very devastating shocks, earthquakes can also trigger cascading events that are no less damaging such as landslides, liquefaction, and tsunamis. This study aims to apply the H3 spatial indexing system to improve earthquake risk assessment using Sorong City as a case study, and compare the result of H3-based risk assessment with the normative risk assessment in Indonesia as defined by relevant Perka BNPB (Badan Nasional Penanggulangan Bencana/National Disaster Management Authority) 2/2012. H3 is an open-source geospatial indexing system developed by Uber, which utilizes a hierarchical hexagonal grid for indexing, calculations, and visualization. The hexagonal cells in the grid have equidistant neighbors and possess the property of expanding neighboring rings, approximating circles and optimizing space filling. The H3 spatial index finds extensive applications in earthquake hazard, vulnerability, capacity, and risk assessment systems. The value of each parameter is entered into each hexagon so that in the end each hexagon has its risk index value. The study shows that the use of H3 in earthquake risk assessment can provide a more detailed level of analysis and indirectly does not depend on regional administrative boundaries. Technically, this advantage provides a more efficient calculation method and is also easier to modify partially both spatially and in terms of the parameters used. Based on the performance evaluation results on the spatial join aspect, H3 provides much faster performance compared to traditional indexing systems. Hence, the H3 spatial index will be very useful to meet the need for an earthquake risk assessment on a larger scale with a higher level of resolution.
The risk of ignorance of DEM Height Reference System on coastal inundation modeling (the case of Jakarta)
Authors: Andreas Heri , Juliandri Firman , Pradipta Dhota , Sarsito Dina A. , Abidin Hasanuddin Z.
Published: October 2023

As a result of continuing land subsidence which is also followed by sea level rise, some lowland coastal areas will experience coastal inundation. The lowlands will gradually become lower than sea level at high tide and even during normal conditions. Some areas where even it is not high tide would experience coastal inundation permanently in certain time. Coastal inundation modeling is important to create, so that we can map potential hazards and disaster risks. With coastal conditions that are usually inhabited by many people, become economic centers and others, then when coastal inundation occurs, material losses will certainly occur. To create a coastal inundation model, parameters are needed including the DEM. The coastal lowlands are represented from the DEM. From the corrected DEM for land subsidence, sea level rise and tidal hydraulic models, with some calculation we will get a coastal inundation model. The most important thing related to this model is the accuracy of the DEM and the height of the reference system. If we do not use an accurate DEM, and do not use the height reference system correctly then we will not get a reliable coastal inundation model. The impact is that we will not be get a correct map the hazards and disaster risks due to the coastal inundation. This paper will demonstrate the risk when we ignore the height reference system, so that we get a miss leading in the dangers and risks of coastal inundation in Jakarta as a case study area. As a result of investigation we can see with incorrect height reference system we found underestimate and or overestimate model and disputed the risk.
Cianjur M5.6 Earthquake Aftershock Survey (CEAS) Using ITB Temporary Seismographs
Authors: Azhari M F , Nugraha A D , Zulfakriza Z , Ry RV , Lesmana A , Putra A S , Muttaqy F , Heryandoko N , Saputra A , Mawadah A , Putri D A , Saputra H S
Published: October 2023

Western Java, part of the Sunda Arc, is an active tectonic region with high seismicity. The tectonic activity has produced active faults which are located near densely populated areas. On November 21, 2022, a significant earthquake rocked the Cianjur region, West Java, causing severe damage and loss of life. In this study we acquired aftershock data which was generated from the Cianjur M5.6 earthquake. Twenty stations consisting of 19 Smartsolo IGU-16HR 3C 5 Hz Seismometer (short-period type) and 1 Guralp 6TD 30s to 100 Hz Seismometer (broadband type) were deployed to monitor aftershocks from 22 November to 23 December 2022. The seismograph stations were deployed covering the earthquake source area and tectonic features in the Cianjur region. The results show that the aftershock events is clearly recorded at 20 stations with an average difference between the arrival times of the S waves and P waves (Ts-Tp) of 2 seconds. A total of ±500 earthquake events were obtained consisting of ±4000 P wave phases and ±3000 S wave phases with a Vp/Vs ratio value of 1.72 and RMS error less than 0.1 second. The Cianjur M5.6 earthquake was classified as a shallow crustal seismicity with a strike slip fault mechanism, hypocenters were generally distributed at a depth of 3-10 km.