bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of drought on optimum temperature of carbon fluxes in temperate grasslands
Authors: Su Tiancheng , Wang Yanbing , You Cuihai , Han Xingguo , Chen Shiping 
Published: November 2024

Abstract
Ecosystem carbon flux components, including ecosystem gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem productivity (NEP), are the most direct indicators of ecosystem production capacity, carbon sequestration, and climate regulation strength. Nevertheless, little is known about how water availability affects the temperature responses of carbon flux components in water-limited ecosystems. Based on a long-term eddy observation dataset of temperate grasslands in northern China, we analyzed the effects of drought on the optimum temperature of carbon flux components (

T

opt

flux

) in temperate grassland ecosystems and clarified the relative contributions of vegetation and climate factors to

T

opt

flux

. We found that the optimum temperatures of carbon flux components were widespread across different grassland types, with a significant lower optimum temperature of NEP (

T

opt

NEP

, 17.32 ± 3.21 °C) than that of GPP (

T

opt

GPP

, 18.67 ± 2.53 °C) and ER (

T

opt

ER

, 19.30 ± 1.94 °C). Drought significantly reduced

T

opt

NEP

, but had no significant effects on

T

opt

GPP

and

T

opt

ER

. Obvious shifts of occurrence date of

T

opt

flux

were also observed in the years with different precipitation regimes. That is,

T

opt

GPP

and

T

opt

NEP

occurred significantly earlier than seasonal maximum temperature (

T

max

) in the dry years, while

T

opt

flux

significantly lagged behind the occurrence of

T

max

in the wet years. Water availability and vegetation factors co-regulated the spatiotemporal variations of

T

opt

flux

. In the dry years, precipitation and soil water content predominated the changes in

T

opt

GPP

and

T

opt

ER

, whereas vegetation structure (leaf area index) and physiological characteristics played a more important role in the wet years. Our study not only provided the first evidence for the widespread existence of

T

opt

flux

of different carbon fluxes, but also addressed the remarkable impacts of drought on

T

opt

flux

and their occurrence date in the water-limited grasslands. Therefore, incorporating the unimodality of these observed temperature responses of ecosystem carbon fluxes into land carbon models is necessary for improving the accuracy of carbon sequestration predictions.
Lack of evidence for alternative stable states in Northern Hemisphere forests during the past 8 ka
Authors: Schild Laura , Hébert Raphaël , Herzschuh Ulrike , Laepple Thomas 
Published: November 2024

Abstract
With increased pressure from anthropogenic climate change, boreal forests are suspected to be approaching tipping points which could cause large-scale changes in tree cover and affect global climatic feedback. However, evidence for this proposed tipping is sparse and relies heavily on observations on short time scales from remote sensing data and space-for-time substitutions. Here we make use of an extensive pollen data set including 239 records of large lakes to investigate the existence of alternative stable forest cover states in the boreal forest and its adjacent biomes during the last 8000 years. By using a multimodality measure on time series of reconstructed tree cover we find very little multimodality in pollen data. To test whether this lack of multimodality is caused by limitations in the paleo data set we perform surrogate experiments. Surrogate data with alternative stable states based on the paleo vegetation–climate relationship were generated and significant multimodality was found more often than for the pollen-based tree cover (24.7% and 5.3% respectively). The response of tree cover to climate may, therefore, be more gradual and not as abrupt as would be expected from remote sensing analyses on stability. The apparent alternative stability hypothesized in the analyses of climate–vegetation relationships could be due to the strong spatial heterogeneity of environmental factors and vegetation responses as an artifact of space-for-time substitutions. Even though current and upcoming shifts in the boreal forest are indisputable and a reason for strong concern, these changes could happen gradually without going through large-scale tipping between alternative stable states. To aid adaptation and conservation measures, more knowledge is needed about boreal forest drivers and their spatial heterogeneity.
Explaining decision structures and data value for neural networks in crop yield prediction
Authors: von Bloh Malte , Seiler Benjamin , van der Smagt Patrick , Asseng Senthold 
Published: November 2024

Abstract
Neural networks are powerful machine learning models, but their reliability and trust are often criticized due to the unclear nature of their internal learned relationships. We explored neural network learning behavior in wheat yield prediction using game theory-based methods (SHapley Additive exPlanations, Shapley-like, cohort Owen), examined data impact on model performance and show optimization approaches. By identifying and removing harmful data samples, we demonstrated a significant improvement in prediction accuracy. We show that neural networks can learn decision patterns that often align with agronomic causal relationships. Building on these insights we propose a novel approach using an autoencoder to detect statistical implausible decisions, allowing us to flag and correct potential ‘misjudgements’, resulting in an 11% reduction in global model error. The proposed explainability methods can optimize the neural network training process through improved data acquisition and revising the internal learning process. This enhancement presents neural networks as trustworthy simulation agents for agricultural research, capable of supporting new scientific discoveries and assisting in real-world applications.
Dual-band circular dichroism in chiral metamaterial absorber based on vanadium dioxide
Authors: Zhenglan Zhou , Junwen Zhu 
Published: November 2024

Abstract
Chiral metamaterial absorbers are instrumental in a wide array of applications, encompassing multifaceted optoelectronic devices, information-encrypting metamaterials, and thermal-controlled imaging and detection systems. In this study, we showcase a Ꞩ-shaped chiral metamaterial integrated with a vanadium dioxide substrate, which enables dynamic tuning of terahertz (THz) dual-band circular dichroism (CD). This absorber boasts spin-selective absorption, stemming from the selective excitation of the plasmon polaron mode on its horizontal microrod. Notably, right-handed circularly polarized light (CPL) experiences near-perfect absorption at resonance, whereas left-handed circular polarization is absorbed to a much lesser degree, yielding pronounced CD. This exceptional chiral selectivity facilitates dual-band CD effects, with peak values reaching 0.814 and 0.784. Furthermore, by manipulating the conductivity of vanadium dioxide, we can dynamically adjust both the CD and absorption peaks of the chiral metamaterial. The maximum modulation depth of the CD response can attain values as high as 0.807 and 0.776. Our work presents a novel design strategy for the active control and modulation of CPL, thereby expanding the horizons of metamaterial absorber applications within the THz spectrum.
The channel capacity of the free space communication link based on Bessel-like beams
Authors: Litvin Igor A , Munar-Vallespir Pere , Nötzel Janis 
Published: November 2024

Abstract
This study investigates the information channel capacity of free-space communication links based on Bessel-like beams (BLBs) and compares it to that of conventional Gaussian beams (GBs). We examine optical communication links employing amplitude coding for beams with BLB spatial field distribution and orbital angular momentum (OAM)-based coding for single-photon optical communication. Our study explores both unperturbed and perturbed propagation scenarios, considering random phase fluctuations caused by atmospheric turbulence and amplitude attenuation due to absorbing obstacles. Our results show that BLBs provide higher channel capacity than GBs at short distances (within a few kilometers of propagation distance), but GBs outperform BLBs at longer distances. In turbulent environments, BLBs experience more significant capacity degradation than GBs, though they maintain higher capacity in OAM-based single-photon links for distances under 1–2 km.
Proposal for superconducting photodiode
Authors: Parafilo A V , Sun M , Sonowal K , Kovalev V M , Savenko I G 
Published: November 2024

Abstract
We propose a concept of a superconducting (SC) photodiode—a device that transforms the energy and ‘spin’ of an external electromagnetic (EM) field into the rectified steady-state supercurrent and develop a microscopic theory describing its properties. For this, we consider a two-dimensional thin film cooled down below the temperature of SC transition with the injected dc supercurrent and exposed to an external EM field with a frequency smaller than the SC gap. As a result, we predict the emergence of a photoexcited quasiparticle current, and, as a consequence, oppositely oriented stationary flow of Cooper pairs. The strength and direction of this photoinduced supercurrent depend on (i) such material properties as the effective impurity scattering time and the nonequilibrium quasiparticles’ energy relaxation time and (ii) such EM field properties as its frequency and polarization.
Effect of welding layers and interlayer temperature on welding residual stress and deformation of Q345/316L dissimilar steel
Authors: Zhu Yongyou , Zheng Jianneng , Li Houbin , Liu Yuping , Huang Bensheng , Li Tianning , Tang Peng 
Published: November 2024

Abstract
Dissimilar steel welding is widely used in machinery, chemical industry, electric power and other fields. Due to the different welding materials, the distribution of residual stress and deformation of welded joints is complex. In order to study the influencing factors and variation rules of residual stress and deformation distribution of dissimilar steel joints, considering the nonlinear physical and mechanical properties of welding materials and the latent heat of phase change during welding, based on the SYSWELD platform, taking Q345 carbon steel and 316L stainless steel as the research objects, the double ellipsoid heat source model was used to study the effects of welding layers and interlayer temperature on the residual stress and deformation of joints. The results show that the increase of the number of welding layers is beneficial to expand the distribution of residual stress, and has no obvious effect on the residual stress of the weld, but it will reduce the residual stress of the base metal near the weld. However, the increase of the number of layers will also aggravate the deformation of the weld. Therefore, it is necessary to consider the design of the number of welding layers considering the thickness of the component. At the same time, the study also found that the interlayer temperature has a certain influence on the residual stress and deformation of the joint. The increase of the interlayer temperature will reduce the welding angle deformation, and has little effect on the transverse shrinkage and the residual stress of the joint. Therefore, a lower interlayer temperature should be selected for multi-layer and multi-pass welding of dissimilar steel to ensure the quality of the welded joint.
Performance characteristics of self-compacting concrete containing lateritic fine aggregate as a partial replacement to natural river sand
Authors: Bhat P Kiran , C Rajasekaran , Das B B 
Published: November 2024

Abstract
This study identifies the use of processed lateritic fine aggregate (LFA) as a sustainable material for the replacement of natural fine aggregate (NFA) in self-compacting concrete (SCC). Cubes were cast with LFA replacements from 10% to 80% with an interval of 10% for checking the compressive strength development at 28 and 90 days. The findings demonstrate that the replacement of 30% NFA with LFA leads to the optimum performance, resulting in compressive strengths of 45.5 MPa and 53 MPa after 28 and 90 days of curing. Similar trends are also noted with the specimens cast for splitting tensile and flexural strengths as per IS 516: 2021. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Thermogravimetric analysis (TGA), and Fourier Transform Infrared Spectroscopy (FTIR) were performed to understand the surface morphology, material characterization, and composition differences between the control mix (C30F) and optimized lateritic SCC (C30F30L). SEM and EDX analysis demonstrated the contribution of the introduced fly ash particles to the strengthening of concrete. TGA with DTA has shown the more complicated denser structure of the C30F mix, and FTIR has confirmed the presence and formation of the C–S–H gel. Si–O–Si asymmetric stretching band has extra peaks, and with FTIR, O–C–O asymmetrical bending and stretching wave band have a lower intensity than the C30F mix due to the partial replacement of LFA. In addition, it is also observed from the durability studies that C30F30L showed an increase in pore volume and capillary pore network compared to C30F mix.
Carbon based materials in conducting tissue engineering
Authors: Sancar Elif , Oktay Büşra , Ahlatcıoğlu Özerol Esma 
Published: November 2024

Abstract
Conducting materials based on carbon have been widely investigated in conducting tissue engineering applications due to their outstanding physical, chemical, thermal, and electric properties in recent years. Carbon based conductive materials can generate or respond to electrical signals, allowing them to provide controlled electrical stimulation to cells or tissues. Conductive tissue engineering (CTE) holds great promise for a wide range of applications, including nerve regeneration, cardiac tissue engineering, muscle tissue engineering and neural interfaces. In this review, recent progress in conducting tissue engineering applications by using these carbon-based materials in conducting tissue engineering including nerve tissue engineering, cardiac tissue engineering, muscle tissue engineering application were given in detail.
Biocompatibility of Bi2Se3 regarding primary mixed retinal cells
Authors: Nguyen Diep , Forster Valérie , Potey Anaïs , Alviset Agathe , Picaud Serge , Politano Antonio 
Published: November 2024

Abstract
Bismuth chalcogenides have a groundbreaking impact on materials science because of their potential applications in spintronics and optoelectronics, especially for their properties as topological insulators. Investigation of the biocompatibility of the electrode material at the tissue/electrode interface is essential to assess the use of topological insulators in bioelectronics. Here, we addressed the biocompatibility of Bi2Se3 by demonstrating that porcine primary mixed retinal cells can survive on its surface with or without poly-D-lysine/laminin coating. Neuronal and glial cell survival were demonstrated using cell culture and imaging techniques. These results highlight the promising potential of Bi2Se3 for integration into bioelectronic devices, particularly for the development of neural interfaces and other biomedical applications.
Improvement of the nylon (N)-glass fiber (G) reinforced polyester composite properties by varying oxide ceramic particles and stacking sequences of N and G
Authors: Sosiati Harini , Fahrezy Rifqy Ahmad , Fahrudin  , Pamasti Ankas , Hata Satoshi , Gao Hongye 
Published: November 2024

Abstract
This study investigated the mechanical and physical properties of hybrid composites made with nylon fiber mesh (N), woven glass fiber (G), and unsaturated polyester (UPE) resin filled with different oxide ceramic particles (CPs) (ZnO, Al2O3, ZrO2, and TiO2). The influence of the stacking order of N and G (GGNNGG, GNGGNG, NGGGGN, and NNGGGG) on the mechanical properties of the composites was also studied. The goals of this study are to determine the best CP and stacking sequence for enhancing composite properties (flexural and impact properties) and reducing water absorption. The composites were manufactured in two steps using hand lay-up and press molding techniques. The first step involved fabricating N/G/UPE-2%CPs composites with a ratio of 8:14:78 (vol%) and a GNGGNG stacking sequence, referred to as type 1. In the second step, a composite with optimum properties obtained from type 1 was used as a reference and compared to composites with three different stacking sequences of GGNNGG, NGGGGN, and NNGGGG, known as type 2. The three-point bending, Charpy impact, and water absorption tests were conducted. The results revealed that the mechanical properties of N/G/UPE-2Al2O3 and N/G/UPE-2ZnO composites are nearly identical and higher than the others. However, N/G/UPE-2Al2O3′s water absorption is lower than that of N/G/UPE-2ZnO. These results suggest that the N/G/UPE-2Al2O3 composite, with a GGNNGG stacking pattern and a flexural strength of 125.12 MPa, an impact strength of 84.2 kJ m−2, and a low water absorption of 0.56%, could potentially serve as biomaterials.
Blending enzyme immobilization enabled high performance glucose sensor based on an n-channel organic electrochemical transistor
Authors: Shi Cheng , Jiang Xingyu , Wang Qi , Xiang Chuan , Dong Xinyu , Chi Lifeng , Huang Lizhen 
Published: November 2024

Abstract
Organic electrochemical transistors (OECTs) have emerged as an advantageous choice for constructing biosensors due to their remarkable water compatibility, low operating voltage, and inherent amplification capability. However, the current research on bio-sensing based on OECTs predominantly employs p–type material PEDOT:PSS as the channel material. Nevertheless, the utilization of a single material and its depleting characteristics impose significant limitations on device miniaturization and integration applications. We present a high-sensitivity glucose sensor based on n-channel accumulation-type OECT through immobilization the glucose oxidase on Pt gate electrode with an blending approach. The glucose oxidase directly mixed with bovine serum albumin, chitosan and immolizied on the gate electode, demonstrating a stable and sensitive response to the glucose. The modified n-channel organic electrochemical transistor demonstrates a highly sensitive response to glucose across a concentration range from μM to mM, with a quantified stable sensitivity over 2.69 mmol–1 by normalizing the current change with respect to concentration. The device also exhibits selectivity towards glucose (compared with high concentrations of lactic acid, different concentration gradients of ascorbic acid, and uric acid), rendering it suitable for noninvasive glucose detection in body fluid like sweat, saliva etc This flexible and ensitive electrochemical transistor sensor holds immense potential for the development of potable healthcare biosensing.
A combined RSM – FEM analysis of weld quality in laser transmission welding of plastics
Authors: Kumar Nitesh , Chakravarty Soumyabrata , Kumar Nikhil , Sen Rajat Subhra 
Published: November 2024

Abstract
This study explores through transmission laser welding of dissimilar, optically transparent polymers, acrylic and polycarbonates using a novel hybrid approach that integrates Response Surface Methodology (RSM) and Finite Element Method (FEM). Quantitative analysis involved a 3 factor, 3 level central composite design with process inputs of laser power, frequency and scanning speed. The resulting weld qualities, such as weld width, Heat Affected Zone (HAZ), ware measured, showing weld width ranges from 112.65 μm to 302.64 μm and HAZ between 20.85 μm to 105 μm. The thermal modelling provided predictions for depth of penetration, with values spanning from 106.25 μm to 228.65 μm. validated against experimental data, demonstrating an average error of 8.09%. Qualitatively, the investigation indicatees that laser power and scanning speed substantially effect the weld quality, with higher power leading to broader weld widths and greater HAZ. The FEM simulations confirmed these trends and provided insights into temperature distributions. The investigation contributes to the existing knowledge pool that would be beneficial to the academia and industries.
Mechanical, thermal, and morphological characterization of polylactic acid composites reinforced with coconut shell activated carbon
Authors: B Rajadurai , J Chandradass 
Published: November 2024

Abstract
Plastic containers are typically produced from non-biodegradable, petroleum-based plastics such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET), which pose considerable environmental issues due to their durability. A process for fabricating composite materials was studied that used the compression molding method to incorporate chemically untreated coconut shell activated carbon (1.5%, 3%, 6%, and 10%) as the reinforcing ingredient within a PLA matrix to evaluate its effect on the mechanical, morphological, thermal, and wettability characteristics. The introduction of AC decreased both tensile and impact strengths, while marginally raising the tensile modulus slightly from 1135.4 MPa to 1138.15 MPa. The addition of an AC filler with PLA matrix did not affect the hardness test. SEM images showed that the higher AC content led to the formation of agglomeration and voids, which reduced the mechanical strength of the material. The DSC analysis revealed an increase in the melting point; however, the TGA data demonstrated a decrease in degradation and an increase in residue at 600 °C, particularly with a higher AC concentration. The FTIR study verified that there were no chemical interactions observed between PLA and AC. The wettability tests showed that AC functions as a barrier, especially at concentrations of 3% and 6%, resulting in decreased water absorption in comparison to pure PLA. The findings indicated that PLA-AC composites improved some PLA characteristics for packaging as they can improve barrier qualities and degrade the PLA material earlier.
Feasibility study on the suitability of dielectric barrier discharge plasma treatment of desert sand for concrete production purposes
Authors: FENNER Yorick , BELLMANN Martin , TÜMMEL Andreas , GERHARD Christoph 
Published: November 2024

Abstract
Due to the continuously increasing building and construction industry, sand has become one of the most questioned raw materials worldwide. However, the available amount of sand suitable for concrete production is orders of magnitude lower that the demand and consumption. Even though desert sand is sufficiently available, it is not usable for realizing stable concrete due to its surface shape. Against this background, the suitability of energy-efficient ‘cold’ dielectric barrier discharge plasma operated at atmospheric pressure for improving the properties of concrete produced from desert sand was investigated in this contribution. It is shown that such plasma treatment allows for a certain roughening and re-shaping of sand grains. As a result, the mass flow of treated sand is decreased due to an improved wedging of sand grains. This leads to a certain increase in compressive strength of concrete samples. Even though this increase is marginal, the suitability of the applied type of plasma for modification of the geometry and surface chemistry of sand grains was proven, showing its basic potential for the treatment and preconditioning of sand used for concrete, mortar or plastering.