bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermodynamic properties and enhancement of diamagnetism in nitrogen doped lutetium hydride synthesized at high pressure
Authors: Han Yifeng , Ou Yunbo , Sun Hualei , Kopaczek Jan , Leonel Gerson J. , Guo Xin , Brugman Benjamin L. , Leinenweber Kurt , Xu Hongwu , Wang Meng , Tongay Sefaattin , Navrotsky Alexandra
Published: March 2024

Nitrogen doped lutetium hydride has drawn global attention in the pursuit of room-temperature superconductivity near ambient pressure and temperature. However, variable synthesis techniques and uncertainty surrounding nitrogen concentration have contributed to extensive debate within the scientific community about this material and its properties. We used a solid-state approach to synthesize nitrogen doped lutetium hydride at high pressure and temperature (HPT) and analyzed the residual starting materials to determine its nitrogen content. High temperature oxide melt solution calorimetry determined the formation enthalpy of LuH
1.96
N
0.02
(LHN) from LuH
2
and LuN to be −28.4 ± 11.4 kJ/mol. Magnetic measurements indicated diamagnetism which increased with nitrogen content. Ambient pressure conductivity measurements observed metallic behavior from 5 to 350 K, and the constant and parabolic magnetoresistance changed with increasing temperature. High pressure conductivity measurements revealed that LHN does not exhibit superconductivity up to 26.6 GPa. We compressed LHN in a diamond anvil cell to 13.7 GPa and measured the Raman signal at each step, with no evidence of any phase transition. Despite the absence of superconductivity, a color change from blue to purple to red was observed with increasing pressure. Thus, our findings confirm the thermodynamic stability of LHN, do not support superconductivity, and provide insights into the origins of its diamagnetism.
A note on no-hair properties of static black holes in four and higher dimensional spacetimes with cosmological constant
Authors: Ishibashi Akihiro , Matsumoto Satoshi , Yoneo Yuichiro
Published: March 2024

We study no-hair properties of static black holes in four and higher dimensional spacetimes with a cosmological constant. For the vanishing cosmological constant case, we show a no-hair theorem and also a no-short-hair theorem under certain conditions for the energy-momentum of matter fields. For the positive cosmological constant case, we discuss conditions for hairy static black holes to exist in terms of the energy density of matter fields evaluated at the black hole horizon and the cosmological horizon. For the negative cosmological constant case, we study conditions for hairy black holes by presenting a no-hair theorem in which the asymptotic structure is assumed to be determined by the true cosmological constant.
Estimation of total forces of jets on liquid interfaces using image processing methods
Authors: Guo Ying , Guo Xuanying , Xu Shaofeng , Shi Jianjun
Published: March 2024

Optical imaging is a fundamental method for detecting plasma phenomena, such as plasma bubbles, plasma streamers, and self-organized plasma patterns. Therefore, data mining of images is crucial in plasma diagnostics. This work presents image processing methods for extracting substructures in plasma bubbles, streamers, and patterns. In our experiment, plasma–liquid interfaces between atmospheric pressure argon-plasma jets and NaCl solutions are quantitatively captured. After extracting accurate plasma–liquid interfaces, traditional analytic functions and machine learning approaches are used to fit curves of interfaces. Regression of machine learning method based on Gaussian process reveals many details of interfaces, but neural networks present smooth and accurate regressions. The gravitational and surface tension forces are calculated using experimental plasma–liquid interfaces. The plasma forces are estimated to be several tens of Pa. However, they increased to several hundred Pa around the inflection points of interfaces. This study extends the application of image processing to plasma diagnostics and provides target data of gas–liquid interfaces for numerical simulations.
Hybrid density functional theory simulation of sodium impurity and impurity–vacancy defect complexes in germanium: perspectives of defect engineering for activation of shallow donors
Authors: Petrenko T L , Bryksa V P , Dyka I V
Published: March 2024

At present, germanium (Ge) as a high-mobility material is considered as a possible replacement for Si in microelectronics. The main obstacle in the method is the large vacancy concentration obtained after the implantation of shallow donors. This prevents the formation of

n

+

regions and has a negative impact on device performance. One way to eliminate the detrimental effects of such defects is through the codoping approach. In this study, the behavior of Na impurities in germanium together with the formation of defect complexes with vacancies, divacancies and shallow donors (P and As) were investigated using hybrid density functional theory calculations. The site preference, diffusion barriers, charge states and binding energies of various complexes, as well as the activation of donor–vacancy complexes with both F and Na codoping were investigated. For this purpose, two extreme cases were considered. Firstly, we calculate the concentrations of substitutional and interstitial Na together with monovacancies in the case of quasi-equilibrium conditions realized for doping from melt. Another extreme case is Na codoping during ion implantation. Our calculations show that Na passivates vacancies, divacancies and donor–vacancy complexes (E-centers) with a large energy gain, which prevents rapid donor diffusion similar to the case of doping with fluorine. We have shown that the passivation of E-centers with both F and Na impurities leads to the back transformation of such complexes into shallow donors. This means that codoping with Na may neutralize the harmful effects of vacancies and is a perspective for defect engineering.
Investigation on the mechanism and a universal structural design method for resistive switching devices
Authors: Yang Bowen , Ma Guokun , Wan Xinyu , Rao Yiheng , Tao Li , Duan Jinxia , Lv Lin , Zhang Jun , Shen Liangping , Wang Hanbin , Wang Hao
Published: March 2024

Resistive random-access memories have attracted significant attention in memory applications, while the physical mechanism behind their resistive switching behavior is still unclear. As a key issue, the migration of oxygen vacancies (VO) directly influences the performance of devices in the formation and rupture of conductive filaments (CFs). In this work, the distance of VO migration is performed as electric field dependent and affects the performance of the device. Sufficient distance of VO migration is essential for formation and rupture of CF completely, leading to, ideally, SET/RESET transition of the device. Based on this mechanism, an enhanced electric field is designed that optimizes the stability of the device significantly, which is demonstrated to be a promising approach to optimize the properties of the device. The investigation is helpful for guiding the design of device structures.
Improving the specific impulse of Hall thrusters using a wide channel design
Authors: Liu Xingyu , Li Hong , Jiang Zhongyu , Ding Yongjie , Wei Liqiu , Yu Daren , Mao Wei
Published: March 2024

This paper proposes increasing the width of the discharge channel to improve the specific impulse of Hall thrusters. In our study, we significantly increased the achievable channel width by optimizing the magnetic circuit topology, and the design freedom of the Hall thruster was improved. A prototype of a wide-channel high-specific-impulse Hall thruster was designed and experimentally verified. The effects of channel width on the discharge process and the characteristics of an aft-loaded magnetic field Hall thruster were investigated. The high-intensity luminous region did not diffuse radially with an increase in the channel width, and the plasma was always concentrated near the channel centerline. A wider channel is more conducive for improving the propellant utilization efficiency, thereby effectively improving the specific impulse of the Hall thruster. By optimizing the discharge channel width, the upper limit of the discharge voltage was increased, and the maximum specific impulse was increased from 3170 to 3794 s, a relative improvement of 20%. The effect of the specific impulse improvement at the same discharge voltage was analyzed and discussed. The results of this study are significant for the design of high-specific-impulse Hall thrusters.
Nanosecond pulsed discharge with plasma-functionalized TiO2 for the high efficiency degradation of tetracycline
Authors: Wang Sen , Wei Xiaoyang , Chen Pengju , Zhou Renwu , Fang Zhi
Published: March 2024

Non-thermal plasma coupling with photocatalyst is recognized as a promising technology for the degradation of antibiotics, and improving the photocatalyst performance is one of the most significant strategies to improve the efficiency of plasma-catalytic systems. This study employed a nanosecond pulsed gas–liquid discharge coupled with plasma-functionalized TiO2 to achieve a high efficiency of tetracycline degradation and clarify the synergistic mechanism of nanosecond pulse discharge coupling with functionalized TiO2. Results showed that the degradation efficiency with functionalized TiO2 increased by 20% compared to the untreated TiO2 for 4 min-plasma treatment. It is also suggested that the effect of photogenerated holes and electrons can be promoted in the functionalized TiO2, as evidenced by the radical quenching experiments. The plasma-modified TiO2 catalysts were proven to have a good stability and recyclability. This study provides a new sustainable approach to enhance the performance of photocatalysts in the plasma system for environmental remediation.
The strain regulated physical properties of PbI2/g-C3N4 for potential optoelectronic device
Authors: Chen Xiunan , Huang Yuhong , Deng Zunyi , Zhao Haili , Ma Fei , Zhang Jianmin , Wei Xiumei
Published: March 2024

The van der Waals (vdW) heterostructures of Z-scheme PbI2/g-C3N4 with an indirect bandgap have gained much attention in recent years due to their unique properties and potential applications in various fields. However, the optoelectronic characteristics and strain-modulated effects are not yet fully understood. By considering this, six stacking models of PbI2/g-C3N4 are proposed and the stablest structure is selected for further investigation. The uniaxial and biaxial strains (−10%–10%) regulated band arrangement, charge distribution, optical absorption in the framework of density functional theory are systematically explored. The compressive uniaxial strain of −8.55% changes the band type from II→I, and the biaxial strains of −7.12%, −5.25%, 8.91% change the band type in a way of II→I→II→I, acting like the ‘band-pass filter’. The uniaxial strains except −10% compressive strain, and the −6%, −4%, 2%, 4%, 10% biaxial strains will enhance the light absorption of PbI2/g-C3N4. The exerted strains on PbI2/g-C3N4 generate different power conversion efficiency (

η

PCE

) values ranging from 3.64% to 25.61%, and the maximum

η

PCE

is generated by −6% biaxial strain. The results of this study will pave the way for the development of new electronic and optoelectronic materials with customized properties in photocatalytic field and optoelectronic devices.
Design, preparation, and property analysis of metal/dielectric multilayer film with wavelength selectivity
Authors: Wu Jiang-Yuan , An Bao-Lin , Dong Wei , Yang Zhen , Duan Yuan-Yuan
Published: March 2024

Metal/dielectric multilayer films have important applications in energy-saving glass, stealth materials, solar energy utilization and other fields. In the current study, the thickness of each layer of TiO2/Ag/TiO2/Ag/TiO2 film is optimized. The effects of the number of metal/dielectric multilayer films and the incident light angle on their optical properties were investigated. The TiO2/Ag/TiO2/Ag/TiO2 film was prepared by electron beam evaporation coating technology, and their reflectance and transmittance were measured. The measurement results show that the visible light transmittance (380–780 nm) of the film can achieve 68.7%, and the infrared reflectance (780–2500 nm) can reach 95.9%. Compared with the traditional dielectric/metal/dielectric three-layer film, the visible light transmittance of the film is higher, and the solar infrared reflectance is greatly improved. In the solar radiation band (280–2500 nm), the average error between the experimental reflectance and transmittance and the theoretical prediction results is less than 0.03. The distribution of electric and magnetic fields inside the film was simulated by finite-difference time-domain method. The simulation results show that the high visible light transmittance is due to the interference resonance of electromagnetic waves inside the film. Taking Shanghai as an example, under our calculation conditions, compared with ordinary SiO2 glass, TiO2/Ag/TiO2/Ag/TiO2 film can reduce the total energy consumption of buildings by 14.3% and refrigeration energy consumption by 17.2%.
An online color and shape integrated detection method for flexible packaging surface defects
Authors: Sun Yi , Wei Jiahong , Li Jinhua , Wei Qin , Ye Weiwei
Published: March 2024

It is difficult for the spectrophotometer to meet the requirement of real-time color defect detection for flexible packaging prints. The false of shape defect detection is caused by artifact interference and insufficient classification accuracy of defect classification network. A color defect detection method for flexible packaging is proposed, which realizes the adaptive adjustment of the correction parameters of the Commission Internationale de l´Eclairage Delta E 2000 (CIEDE2000) equations with the detection object. It improves the speed and accuracy of the color defect detection for flexible packaging. An quadratic difference strategy is designed for template matching subtraction method to remove artifact interference. A method for enhancing shape defect data set of flexible packaging is proposed. Using discrete images of defects as network input, self-attention mechanism and spectral normalization methods are added to the deep convolutional generative adversarial networks (DCGAN) to enhance the effective dataset for the training of defect classification network. The accuracy of color detection for flexible packaging prints is improved by 38.7% based on optimized CIEDE2000. The average structure similarity index measure (SSIM) value of the improved DCGAN for defect detection is 0.845, and the Fréchet inception distance (FID) is 121.463. It takes 83.63 ms for the color and shape integrated detection method to detect shape defects on flexible packaging surfaces with an accuracy of 98.3%. The online color and shape integrated detection method can be applied to automated flexible packaging workshops to achieve real-time defect detection.
Cathodoluminescence investigations of dark-line defects in platelet-based InGaN nano-LED structures
Authors: Gustafsson Anders , Persson Axel R , Persson Per O Å , Darakchieva Vanya , Bi Zhaoxia , Samuelson Lars
Published: March 2024

We have investigated the optical properties of heterostructured InGaN platelets aiming at red emission, intended for use as nano-scaled light-emitting diodes. The focus is on the presence of non-radiative emission in the form of dark line defects. We have performed the study using hyperspectral cathodoluminescence imaging. The platelets were grown on a template consisting of InGaN pyramids, flattened by chemical mechanical polishing. These templates are defect free, whereas the dark line defects are introduced in the lower barrier and tend to propagate through all the subsequent layers, as revealed by the imaging of different layers in the structure. We conclude that the dark line defects are caused by stacking mismatch boundaries introduced by multiple seeding and step bunching at the edges of the as-polished, dome shaped templates. To avoid these defects, we suggest that the starting material must be flat rather than dome shaped.
Hard congestion limit of the dissipative Aw–Rascle system
Authors: Chaudhuri N , Navoret L , Perrin C , Zatorska E
Published: March 2024

In this study, we analyse the famous Aw–Rascle system in which the difference between the actual and the desired velocities (the offset function) is a gradient of a singular function of the density. This leads to a dissipation in the momentum equation which vanishes when the density is zero. The resulting system of PDEs can be used to model traffic or suspension flows in one dimension with the maximal packing constraint taken into account. After proving the global existence of smooth solutions, we study the so-called ‘hard congestion limit’, and show the convergence of a subsequence of solutions towards a weak solution of a hybrid free-congested system. This is also illustrated numerically using a numerical scheme proposed for the model studied. In the context of suspension flows, this limit can be seen as the transition from a suspension regime, driven by lubrication forces, towards a granular regime, driven by the contacts between the grains.
Critical transitions for scalar nonautonomous systems with concave nonlinearities: some rigorous estimates
Authors: Longo Iacopo P , Núñez Carmen , Obaya Rafael
Published: March 2024

The global dynamics of a nonautonomous Carathéodory scalar ordinary differential equationx′=f(t,x), given by a functionfwhich is concave inx, is determined by the existence or absence of an attractor-repeller pair of hyperbolic solutions. This property, here extended to a very general setting, is the key point to classify the dynamics of an equation which is a transition between two nonautonomous asymptotic limiting equations, both with an attractor-repeller pair. The main focus of the paper is to get rigorous criteria guaranteeing tracking (i.e. connection between the attractors of the past and the future) or tipping (absence of connection) for the particular case of equationsx′=f(t,x−Γ(t)), where Γ is asymptotically constant. Some computer simulations show the accuracy of the obtained estimates, which provide a powerful way to determine the occurrence of critical transitions without relying on a numerical approximation of the (always existing) locally pullback attractor.
Bounce of a rubber ball on a slippery surface: answer
Authors: Cross Rod
Published: March 2024

Video film of a rubber ball bouncing on three different surfaces shows that wet surfaces can be very slippery.
Comment on ‘Acceleration of a car from rest: friction, power and forces’
Authors: Cross Rod
Published: March 2024

The work done by static friction on the wheels of a car is zero, despite the fact that the friction force is directly responsible for its acceleration. The problem can be resolved by considering the torque generated by the friction force.
Evaluation of monolithic crystal detector with dual-ended readout utilizing multiplexing method
Authors: Zeng Xiangtao , Zhang Zhiming , Li Daowu , Huang Xianchao , Wang Zhuoran , Wang Yingjie , Zhou Wei , Wang Peilin , Zhu Meiling , Wei Qing , Gong Huixing , Wei Long
Published: March 2024

Objective. Monolithic crystal detectors are increasingly being applied in positron emission tomography (PET) devices owing to their excellent depth-of-interaction (DOI) resolution capabilities and high detection efficiency. In this study, we constructed and evaluated a dual-ended readout monolithic crystal detector based on a multiplexing method. Approach. We employed two 12 × 12 silicon photomultiplier (SiPM) arrays for readout, and the signals from the 12 × 12 array were merged into 12 X and 12 Y channels using channel multiplexing. In 2D reconstruction, three methods based on the centre of gravity (COG) were compared, and the concept of thresholds was introduced. Furthermore, a light convolutional neural network (CNN) was employed for testing. To enhance depth localization resolution, we proposed a method by utilizing the mutual information from both ends of the SiPMs. The source width and collimation effect were simulated using GEANT4, and the intrinsic spatial resolution was separated from the measured values. Main results. At an operational voltage of 29 V for the SiPM, an energy resolution of approximately 12.5 % was achieved. By subtracting a 0.8 % threshold from the total energy in every channel, a 2D spatial resolution of approximately 0.90 mm full width at half maximum (FWHM) can be obtained. Furthermore, a higher level of resolution, approximately 0.80 mm FWHM, was achieved using a CNN, with some alleviation of edge effects. With the proposed DOI method, a significant 1.36 mm FWHM average DOI resolution can be achieved. Additionally, it was found that polishing and black coating on the crystal surface yielded smaller edge effects compared to a rough surface with a black coating. Significance. The introduction of a threshold in COG method and a dual-ended readout scheme can lead to excellent spatial resolution for monolithic crystal detectors, which can help to develop PET systems with both high sensitivity and high spatial resolution.
Anomalies-Rich Floquet superconductivities induced by joint modulation of dynamic driving and static parameters
Authors: Wang Donghao , Cen Cong , Lu Liangliang , Li Mengyao , Ding Zixuan , Tao Yongchun , Hu Jingguo
Published: March 2024

Current theoretical and experimental endeavors to realize an anomalous Floquet chiral topological superconductor (TSC), which is characterized by chiral Majorana edge modes independent of the Chern number, remain insufficient. Herein, we propose a new scheme that involves jointly tuning dynamic driving and static parameters within a magnetic topological insulator-superconductor sandwich structure to achieve this goal. The Josephson phase modulation induced by an applied bias voltage across the structure is utilized as a Floquet periodic drive. It is found that the interplay between the two kinds of tunings can bring about a lot more exotic Floquet TSC phases than those caused by only tuning the dynamic driving parameter (frequency ω or period τ). More importantly, just tuning static parameters (the chemical potential µ, Zeeman field gz
, and proximity-induced superconducting energy gap

Δ
b

) also can induce a series of novel topological phase transitions. Particularly, the features in the context of the three tunings are different from each other, originating from the combination of intrinsic and different extrinsic mechanisms. In addition, jointly tuning τ and µ (gz
) can have its own unique TSC phases. The proposed scheme should be readily accessible in experiments, and thus the family of anomalous Floquet TSC phases may be considerably enriched.
Mass spectrum of hexaquarks in the Gürsey-Radicati mass formula
Authors: Shiri N , Tazimi N
Published: March 2024

It is conventionally claimed that hexaquarks are exotic particles, most of which we know have not yet been experimentally detected. In this work, we attempt to extend a simple phenomenological model based on the Gürsey-Radicati mass model for hadrons, including charm and bottom baryons, and predict the mass of dibaryon states. To illustrate our goal, we perform a numerical tuning of this model, which consists of five sets, each containing six or seven free parameters for baryons and dibaryons. In the long run, other predicted values for the mass of the extra hexaquarks may turn out to be consistent with the forthcoming experimental results. As we have claimed, the results of this work give us a deeper insight into the structural properties of six-quark particles. Finally, we have also included other available data from other works and compared them with ours.
An algorithm based on 6D fractional order hyperchaotic system and knight tour algorithm to encrypt image
Authors: He Chenchen , Chen Zhong , Wang Lujie , Wu Ximei , Liu Tongzhe , Long Bofeng
Published: March 2024

The security guarantee of data transmission is becoming more crucial as the frequency of information interchange rises. Ensuring the security of images is essential since they serve as a vital transmission medium. This research suggests an image encryption method that combines the knight tour algorithm with a 6D fractional order hyperchaotic system. First, chaotic sequences are produced using a fractional order hyperchaotic system, which is then utilized to index order and jumble the entire image. To retrieve the image after the second scrambling, choose the knight tour beginning point and run ten rounds of knight tour algorithms on the scrambled image. Thirdly, to maximize the efficiency of picture encryption, employ diffusion methods. The outcomes of the imaging experiment were lastly tested and assessed. The security of the image can be successfully guaranteed by a high-dimensional fractional order hyperchaotic system. This is because its high dimensionality gives it a larger key space than the low dimensional system. This is why it can resist attacks more effectively. After a series of evaluation experiments, it is obvious that this encryption scheme has good encryption performance.
Thermodynamical analysis with extended phase transition of AdS hairy black hole in gravitational decoupling theory
Authors: Abbas G , Ali R H , Mustafa G
Published: March 2024

This article explores various thermodynamical aspects and the extended phase space of the AdS hairy black hole within the context of gravitational decoupling. This study focused on thermodynamic properties such as geometrical mass, Hawking temperature, entropy, specific heat, Gibbs free energy (both locally and globally) and P-V criticality at the horizon radius. The thermodynamic stability of the AdS hairy black hole has been established based on its positive heat capacity. The analysis of Gibbs free energy is utilized to investigate the behavior of the first-order phase transition. Thermodynamic pressure, denoted by P, is related to the cosmological constant by the formula

P
=
−

Λ

8
π

. In addition, a numerical investigation has been carried out to examine the equation of the state parameter and its critical values.
A δ-free approach to quantization of transmission lines connected to lumped circuits
Authors: Forestiere Carlo , Miano Giovanni
Published: March 2024

The quantization of systems composed of transmission lines connected to lumped circuits poses significant challenges, arising from the interaction between continuous and discrete degrees of freedom. A widely adopted strategy, based on the pioneering work of Yurke and Denker, entails representing the lumped circuit contributions using Lagrangian densities that incorporate Dirac δ-functions. However, this approach introduces complications, as highlighted in the recent literature, including divergent momentum densities, necessitating the use of regularization techniques. In this work, we introduce a δ-free Lagrangian formulation for a transmission line capacitively coupled to a lumped circuit without the need for a discretization of the transmission line or mode expansions. This is achieved by explicitly enforcing boundary conditions at the line ends in the principle of least action. In this framework, the quantization and the derivation of the Heisenberg equations of the network are straightforward. We obtain a reduced model for the lumped circuit in the quantum Langevin form, which is valid for any coupling strength between the line and the lumped circuit. We apply our approach to an analytically solvable network consisting of a semi-infinite transmission line capacitively coupled to an LC circuit and study the behavior of the network as the coupling strength varies.
The essentials of the finite element method to solve differential equations: an illustrative case in physics
Authors: Chávez-Páez Martín , González-Tovar Enrique , Guerrero-García Guillermo Iván , Guevara-Zapata Guillermo , Padrón-Zamora José Marcelo
Published: March 2024

Here we review the basic steps of the modern and accurate finite element method in its application to solve ordinary differential equations in physics. To exemplify this well-in-vogue numerical technique, we have chosen the second order Poisson-Boltzmann equation, which is a classic equation of colloid science. Aiming to formulate a viable, but didactic, implementation of the finite element technique, we have combined a linear basis of functions, the Galerkin weighted residuals method, the Swartz-Wendroff approximation and the Picard iteration algorithm. In summary, the finite element method transforms a differential equation into a simpler system of algebraic equations for the coefficients of the approximate solution in terms of a set of basis functions. We describe the full computational realisation of the finite element procedure and, also, we examine the corresponding Poisson-Boltzmann numerical predictions for various representative conditions.
Imprint of inflationary gravitational waves and WIMP dark matter in pulsar timing array data
Authors: Borah Debasish , Das Suruj Jyoti , Samanta Rome
Published: March 2024

Motivated by the recent release of new results from five different pulsar timing array (PTA) experiments claiming to have found compelling evidence for primordial gravitational waves (GW) at nano-Hz frequencies, we consider the prospects of generating such a signal from inflationary blue-tilted tensor power spectrum in a specific dark matter (DM) scenario dubbed as Miracle-less WIMP. While Miracle-less WIMP, due to insufficient interaction rate with the Standard Model (SM) bath gets thermally overproduced, inflationary blue-tilted gravitational waves (BGW) in compliance with PTA data, conflict cosmological observations if reheat temperature after inflation is sufficiently high. Both these issues are circumvented with late entropy dilution, bringing DM abundance within observational limits and creating a doubly-peaked feature in the BGW spectrum consistent with cosmological observations. The blue-tilted tail of the low-frequency peak can fit NANOGrav 15 yr data, while other parts of the spectrum are within reach of present and future GW experiments.
Multi-tracer power spectra and bispectra: formalism
Authors: Karagiannis Dionysios , Maartens Roy , Fonseca José , Camera Stefano , Clarkson Chris
Published: March 2024

The power spectrum and bispectrum of dark matter tracers are key and complementary probes of the Universe. Next-generation surveys will deliver good measurements of the bispectrum, opening the door to improved cosmological constraints and the breaking of parameter degeneracies, from the combination of the power spectrum and bispectrum. Multi-tracer power spectra have been used to suppress cosmic variance and mitigate the effects of nuisance parameters and systematics. We present a bispectrum multi-tracer formalism that can be applied to next-generation survey data. Then we perform a simple Fisher analysis to illustrate qualitatively the improved precision on primordial non-Gaussianity that is expected to come from the bispectrum multi-tracer. In addition, we investigate the parametric dependence of conditional errors from multi-tracer power spectra and multi-tracer bispectra, on the differences between the biases and the number densities of two tracers. Our results suggest that optimal constraints arise from maximising the ratio of number densities, the difference between the linear biases, the difference between the quadratic biases, and the difference between the products b
1
b
Φ for each tracer, where b
Φ is the bias for the primordial potential.
The phytochemical constituent and antioxidant activity of Sea Weed Euchaema Cottonii
Authors: Widiawati Y , Widodo S , Herliatika A , Shiddieqy M I , Rohaeni E S , Rakhmani S I W , Rofiq M N , Asmairicen S , Bansi H , Widaringsih W , Andreas E M W
Published: March 2024

This study aimed to determine the phytochemical content and antioxidant activity of the red sea weed Euchaema cottonii. The phytochemical component of this seaweed can be used as an agent for enteric methane mitigation. The antioxidant can be used to reduce the reaction of free radicals when the animals are in heat stress conditions. The study presented used fresh and oven-dried E. cottonii. The methods of study started with the extracting process of two seaweed samples (fresh and sundried) using 3 types of solutions, namely water, hexane, and dichloromethane (DCM). The phytochemical content was analyzed using spektro-tanat, while antioxidant activity was determined using the DPPH test (1,1-diphenyl-2-picrilhidrazil). The result showed that the extract seaweed E. cottonii contained alkaloid, flavonoid, saponin, and steroid/triterpenoid. The seaweed did not contain tannin. The seaweed contains 0.249 to 2.430 mg TAE/gram of total phenolic. Based on the results of the antioxidant activity test using DPPH obtained extract seaweed E. cottonii is active as an antioxidant. The highest phytochemical and phenolic content resulted when the dried seaweed was extracted using the DCM. It is concluded that sea weed E. cottonii contains some phytochemicals and has an antioxidant activity.
Study of interception, throughfall, and stemflow on seven types of Syzygium sp. tree collected by Purwodadi Botanical Garden
Authors: Rahmania F N , Prahardika B A , Irawanto R
Published: March 2024

Syzygium genus is one of the abundant and naturally growing collections of Purwodadi Botanical Garden (KRP) with characteristics of strong and deep rooting with branching and complex crowns. So it has the potential to support water and soil conservation by reducing erosion and kinetic energy of rainwater to the ground. This study aims to determine the value of interception, throughfall, and stemflow in seven types of Syzygium sp. trees in the KRP collection. The research was conducted from January to February 2023 with the method of measuring tree physical factors, collecting, and calculating rainfall data, throughfall, stemflow, and interception values. The results of the study during 25 rainy days on seven types of Syzygium sp. trees showed that the value of throughfall ranged from 10.86 - 15.30 mm with the highest on Syzygium malaccense trees with dangling branching. The stemflow value ranges from 0.04 - 0.91 mm with the highest in Syzygium acuminatisimum trees whose stems grow upright. The interception value ranged from 2.3 - 5.8 mm with the highest in Syzygium polycephalum trees whose branching away from the ground surface. The variation values obtained are influenced by the characteristics of the branching crown of each tree.
Effect of pH variation on chemical components and antifungal activity of ketepeng cina (Cassia alata L.) leaves extract
Authors: Masyita R N , Barokah Z A , Anggraeni Y , Soleha M , Angelina M
Published: March 2024

Ketepeng cina (Cassia alata, L.) has been widely used as a traditional medicine, one of which is as an antifungal. Previous research showed problems with the storage of ketepeng cina leaves extract, which reported changes in pH and color over time. This study explored the effect on concentration of chemical components and antifungal activity under varying pH. Antifungal activity against Candida albicans was tested using microdilution and well diffusion methods. HPTLC technique was measured the chemical components of the extract represented by aloe-emodin and kaempferol concentration. The extract with pH 4.5 had the highest aloeemodin content and antifungal activity. The result of our research were the pH variation significant influence on anti fungal activity against C.albicans, where the best results are at pH 5.5 (p<0.05). The level of active components in the extract is influenced by the pH conditions (p<0.05). Specifically, the levels of kaempferol and aloe-emodin are maximum at a pH of 5.5. It can be concluded that pH can affect the levels of chemical components and antifungal activity in ethanol extracts of ketepeng cina (Cassia alata, L.) leaves.
Biopriming of cayenne seed (Capsicum frutescens L.) using Indole Acetic Acid (IAA) - producing fluorescent pseudomonads to increase germination and growth of seeds
Authors: Advinda L , Chatri M , Handayani D , Suwarni L
Published: March 2024

Capsicum frutescens L. is one of the horticultural commodities that plays an important role as food and industrial raw materials. The amount of chili consumption continues to increase, so its production requires quality seeds. The physiological quality of seeds can be improved, one of which is by using fluorescent pseudomonads as biopriming. The fluorescent pseudomonads LAHLS1, LAHT1, LAHCS2, and PfPb3 produced Indole Acetic Acid (IAA) with concentrations between 5.37 to 20.31 ppm, and were significantly different. Biopriming of C. frutescens L. seeds using different fluorescent pseudomonad isolates affected the percentage of germination, wet weight and dry weight of C. frutescens L. seedlings. Fluorescent pseudomonads LAHLS1, LAHT1, LAHCS2, and PfPb3 can increase the percentage of C. frutescens L. seed germination up to 100%. The highest seedling wet weight (43.52 mg) was found in seed biopriming using fluorescent pseudomonad LAHLS1 and the lowest was control (12.33 mg). The highest seedling dry weight (4.40 mg) was found in seed biopriming using fluorescent pseudomonad LAHLS1, and the lowest was control (0.93 mg). The results showed the potential use of IAA-producing fluorescent pseudomonads in increasing the percentage of seed germination and influencing the growth of C. frutescens L. seedlings based on observations of wet weight and dry weight of seeds.
The phytochemical composition of medicinal plants in Indonesia and their potential as antibacterial agents against Salmonella typhi ATCC 13311
Authors: Maharani A A , Puspawati N , Rukmana R M
Published: March 2024

Several Indonesian medicinal plants are commonly utilized as antibacterial agents, namely moringa (Moringa oleifera Lamk.), green tea (Camellia sinensis), binahong (Anredera cordifolia (Ten.) Steenis), and green meniran (Phyllanthus niruri L.). This investigation aimed to identify the chemical compounds found in plants and their antibacterial activity against Salmonella typhi. The simplicia was extracted by the maceration technique with a solvent of 70% ethanol. Chemical compounds are identified using various chemical reagents. The antibacterial activity test was conducted using the diffusion method. The data were analyzed using a one-way analysis of variance (ANOVA) test. The phytochemical analysis of plant samples revealed the presence of many bioactive compounds such as flavonoids, saponins, tannins, alkaloids, steroids, and phenolics. The antibacterial activity of plant samples against Salmonella typhi has been shown. The average values of the inhibition zones for moringa leaf extract, green tea, binahong, and green meniran were determined to be 20.33 mm, 18.33 mm, 22.67 mm, and 27.00 mm, respectively. The antibacterial activity of green meniran leaf extract is significantly more potent against Salmonella typhi than other plant.
The palm oil-based chlorophyll removal and the evaluation of antiaging properties on Centella asiatica ethanolic extract
Authors: Haryanti S , Budiarti M , Farida S , Dewi A P K , Supriyati N , Jokopriyambodo W , Wahyono S , Widowati L
Published: March 2024

Centella asiatica is an essential medicinal herb in numerous traditions. The high chlorophyll concentration of C. asiatica makes dosage form formulation challenging. On the other hand, palm oil is feasible to eliminate the chlorophyll from plant-based products. This research aim to analysis the phytochemical profile and in vitro anti-aging effects on chlorophyll removal of C. asiatica extract. The extract was soxhletated in 70% ethanol. The extract was partitioned with 50% ethanol and palm oil to create a dechlorophyllation extract. Asiaticoside was analyzed using TLC-densitometry. The cytoprotective effect of H2O2-induced oxidative stress in Vero cells was assessed using MTT assays. Flow cytometer analysis was used for quantifying the intracellular ROS. The senescence-associated-β-galactosidase assay was used to identify senescent cells. The efficiency of chlorophyll removal by palm oil was 90.94±0.62%. The dechlorophyllation extract (DE) showed a concentration of 1.58±0.02% for asiaticoside, but it was not found in the original extract (OE). DE significantly reduced H2O2-induced cytotoxicity in Vero cells compared to OE. Both DE and OE reduced intracellular ROS and senescent cells. Palm oil-based chlorophyll removal improved the phytochemical content and anti-aging effects of C. asiatica in ethanolic extract.
Early detection of sweet potato weevil (Cylas formicarius) and scab diseases (Sphaceloma batatas) outbreak based on android application
Authors: Bayu M S Y I , Prayogo Y , Indiati S W , Sumartini  , Indriyani F C , Susanto G W A , Yuniar E , Trizelia
Published: March 2024

Sweet potato weevil and scab disease are major pests and diseases that become obstacles for increasing sweet potato production in Indonesia. Recently, the incidence of both pest and disease attacks can be detected earlier by using an android-based mobile application. This study aims to assemble an android-based mobile application for early detection of the outbreak of sweet potato weevil and scab disease. This research was conducted in in Malang Regency, East Java, from September to December 2022. Research was carried out by survey, observation, literature studies, and interview with the leaders of farmer association, sweet potato farmers, and local agricultural extension staff. All basic data and supporting data as a trigger for the occurrence of the weevil and scab disease have been collected from the several sample areas. The information was arranged in clusters according to the priority of each variable then was entered into the android studio. The user must enter the supporting data based on the application program to find out the percentage of sweet potato weevil and scab disease. Understanding the predictive value of the incidence of major pests and diseases is required, so farmers can anticipate earlier and prepare appropriate, effective and efficient control technology. An-android mobile application version 1 for early detection of pest and disease which was successfully assembled was expected to be greatly assist sweet potato farmers for maintain their cultivation from yield losses due to C. formicarius and scab which can reduce the quantity and quality by up to 100%.
Analysis of chemical-mineralogical content of brick waste as a pozzolan substitute material in blended cement
Authors: Aini S A , Amalia S , Muiz A
Published: March 2024

Bricks are building materials that contain compounds that can increase the compressive strength of a building. This research utilized waste bricks as a substitute for pozzolan for cement manufacture. Testing of waste bricks using the reactivity index test method, characterization with XRD and XRF. Cement powder was tested chemically, and determined the value of its compressive strength on the mortar test object. The results of the characterization of XRF instruments are SiO2, Al2O3, Fe2O3 with minor compounds including CaO, ZnO, TiO2, K2O, P2O5, CuO, V2O5, Cr2O3, MnO, SrO, Eu2O3, and Re2O7. Meanwhile, BaO is owned only by the first and third bricks, while PbO is owned by the first. The number of SiO2, Al2O3, and Fe2O3 compounds has met the quality requirements as pozzolanic materials (>70%), namely 84.20% of the first sample, 83.70% of the second sample, and 84.30% of the third sample. The reactivity index test also met the target (>75%), namely 75.60% of the first sample, 75.00% of the second sample, and 77.90% of the third sample. The higher the content and the reactiveness of an oxide compound in the waste bricks are directly proportional to the quality of the cement
Molecular docking of selected steroid compounds from Hydrilla Verticillata on human Ros1 kinase receptor
Authors: Fasya A G , Warsito  , Masruri  , Rollando  , Megawati D S
Published: March 2024

Hydrilla verticillata, an aquatic plant, contains various steroids like stigmasterol, β-sitosterol, fucosterol, cholesterol, and campesterol with potential antioxidant properties. Antioxidants protect cells and tissues from Reactive Oxygen Species (ROS)-induced damage by impeding oxidation reactions and ROS elimination. This study aimed to investigate the molecular docking results of selected steroid compounds from H. verticillata with the human ROS1 kinase receptor. Five selected steroid compounds, collected from the PubChem database. The human ROS1 kinase receptor, PDB ID 3ZBF, was obtained from the RCSB Protein Data Bank. Molecular docking of these selected steroid compounds to human ROS1 Kinase was performed, comparing their binding affinities to crizotinib (native ligand) and ascorbic acid. The docking utilized the PyRx Virtual Screening Tool and visualization via BIOVIA Discovery Studio Visualizer. Results indicated that stigmasterol, β-sitosterol, fucosterol, cholesterol, and campesterol had binding affinities of -8.1, -8.2, -8.6, -8.4, and -8.5 kcal/mol, respectively, to the 3ZBF human ROS1 kinase receptor. While, crizotinib and ascorbic acid exhibited binding affinities of -8.4 kcal/mol and -4.7 kcal/mol. Some H. verticillata steroid compounds displayed stronger binding affinities than crizotinib and ascorbic acid. Furthermore, these compounds complied with Lipinski’s and Veber’s rules and achieved bioavailability score of 0.55, suggesting their potential as antioxidants and anticancers.
Identification of acetic acid levels in ecoenzyme from organic materials of orange peel with acid-base titration method
Authors: Farma S A , Islami A , Putri I L E , Handayani D , Putri D H , Anhar A
Published: March 2024

This study aimed to elucidate the comparison of the levels of acetic acid and the pH of the ecoenzymes from organic matter variations of sweet and sour orange peels. The acetic acid is an organic compound containing a carboxylic acid group which is also widely applied in the health and industrial fields. Preparation of acetic acid from substrate products containing ethanol which can be obtained from fruit ingredients including oranges. One of the uses and management of organic waste, including vegetables and fruit, is by making ecoenzymes from fruit peels with a mixture of water and sugar. Fruit peels that can be used as organic ecoenzyme ingredients vary widely, so the content in ecoenzymes becomes very diverse and tends to be unstable. This type of research is descriptive. This study consisted of three stages, namely the manufacture of ecoenzymes from pasaman orange peel, gunung omeh, kaffir lime and lime in 7 variations (for 100 days), measurement of acetic acid levels and pH in the ecoenyzme samples for 14 days and 100 days. Acetic acid levels were determined using the acid-base titration method. The results of this study showed that the highest levels of acetic acid ecoenzyme in the 100-day fermentation were 5.53% in the sour orange group, while the lowest in the mixed ecoenzyme was 3.32%. The most acidic ecoenzyme pH was at 100 days of fermentation (pH ±3.5).