bluuebunny/crossref_metadata_2025 huggingface dataset:
Higher fees and out-of-pocket costs in radiotherapy point to a need for funding reform
Authors: van Gool Kees , Hall Jane , Haywood Philip , Liu Dan , Yu Serena , Webster Samuel B. G. , Moradi Bahare , Aranda Sanchia
Published: May 2023

Objective To elucidate the policy implications of recent trends in the funding of radiotherapy services between 2009–10 and 2021–22. Method We use national aggregate claims data to determine time trends in the fees, benefits and out-of-pocket (OOP) costs of radiotherapy and nuclear therapeutic medicine claims funded through the Medicare Benefits Schedule (MBS) program. All dollar figures are expressed in constant 2021 Australian dollars. Results Radiotherapy and nuclear therapeutic medicine MBS claims increased by 78% whereas MBS funding increased by 137% between 2009–10 and 2021–22. The main driver of Medicare funding growth has been the Extended Medicare Safety Net, which has increased by 404%. Over the 13 year observation period, the percentage of bulk-billed claims peaked in 2017–18 at 76.1% but fell to 69.8% in 2021–22. For non-bulk billed services, average OOP costs per claim increased from $20.40 in 2009–10 to $69.78 in 2021–22. Conclusion Despite increased Medicare funding, patients face increasing financial barriers to access radiation oncology services. Policies with regard to funding radiotherapy services should be reviewed to ensure that services are easily accessible and affordable for all those needing treatment and at a reasonable cost to Government.
Repression of CENP-A assembly in metaphase requires HJURP phosphorylation and inhibition by M18BP1
Authors: Flores Servin Julio C. , Brown Rachel R. , Straight Aaron F.
Published: May 2023

Centromeres are the foundation for mitotic kinetochore assembly and thus are essential for chromosome segregation. Centromeres are epigenetically defined by nucleosomes containing the histone H3 variant CENP-A. CENP-A nucleosome assembly is uncoupled from replication and occurs in G1, but how cells control this timing is incompletely understood. The formation of CENP-A nucleosomes in vertebrates requires CENP-C and the Mis18 complex which recruit the CENP-A chaperone HJURP to centromeres. Using a cell-free system for centromere assembly in X. laevis egg extracts, we discover two activities that inhibit CENP-A assembly in metaphase. HJURP phosphorylation prevents the interaction between HJURP and CENP-C in metaphase, blocking the delivery of soluble CENP-A to centromeres. Non-phosphorylatable mutants of HJURP constitutively bind CENP-C in metaphase but are not sufficient for new CENP-A assembly. We find that the M18BP1.S subunit of the Mis18 complex also binds to CENP-C to competitively inhibit HJURP’s access to centromeres. Removal of these two inhibitory activities causes CENP-A assembly in metaphase.
Identifying molecules with high electrical strength
Authors: Wang Chunlin , Cooper Bridgette , Tennyson Jonathan
Published: May 2023

A search is conducted for possible gases with high electrical strength which could replace the widely used SF6 which has high global warming potential (GWP). The possible electrical strength of a molecule is assessed on the basis of low-energy electron collisions with low-energy resonances or weakly bound states taken as a possible indicator of high electrical strength. At the same time the energy of the highest occupied molecular orbital (HOMO) is used to assess the molecules’ GWP. A total of 62 small flourocarbon molecules are considered allowing the influence of different molecular structures (double bonded, triple bonded and cyclic) and the inclusion of different elements (hydrogen, nitrogen and oxygen) on the electrical strength to be assessed. Eight molecules show low-energy resonance and a further four have negative R-matrix poles implying that they support an anionic state. Our calculations suggest that molecules with double bonded structures, especially involving C = N, should have the best electrical strength, followed by cyclic and then triple bonded structures. Calculation on the C3F6−n
H
n
(n = 0, 6) series suggest that introducing H atoms in selected positions can decrease GWP while retaining the electrical strength of pure fluorocarbon gases like C3F6.
Optical solitons and exact solutions of the (2+1) dimensional conformal time fractional Kundu-Mukherjee-Naskar equation via novel extended techniques
Authors: Gupta Rajesh Kumar , Yadav Poonam
Published: May 2023

The current work uses a (2+1) dimensional conformal time fractional Kundu-Mukherjee-Naskar (KMN) model to investigate optical soliton transmission across an optical fiber that maintains polarization. Three constructive techniques, namely, the extended power series solution, the new generalized method, and the extended sinh-Gordon expansion method are utilized to find the exact soliton solutions of this model. The invariant analysis has been performed on the (2+1) dimensional time fractional KMN model by using the conformal time fractional derivative. The symmetries obtained using conformal fractional derivative are compared with the symmetries obtained for integer order KMN model because symmetries using Riemann Liouville fractional derivative turned out to be trivial. The given system of fractional PDEs has been reduced by using differential invariants obtained from various linear combinations of vector fields associated with the infinitesimal generator of symmetry transformations. These reduced systems of equations are then investigated for their exact solutions.
Automated assembly of high-density carbon fiber electrode arrays for single unit electrophysiological recordings
Authors: Dong Tianshu , Chen Lei , Patel Paras R , Richie Julianna M , Chestek Cynthia A , Shih Albert J
Published: May 2023

Objective. Carbon fiber (CF) is good for chronic neural recording due to the small diameter (7 µm), high Young’s modulus, and low electrical resistance, but most high-density carbon fiber (HDCF) arrays are manually assembled with labor-intensive procedures and limited by the accuracy and repeatability of the operator handling. A machine to automate the assembly is desired. Approach. The HDCF array assembly machine contains: (1) a roller-based CF extruder, (2) a motion system with three linear and one rotary stages, (3) an imaging system with two digital microscope cameras, and (4) a laser cutter. The roller-based extruder automatically feeds single CF as raw material. The motion system aligns the CF with the array backend then places it. The imaging system observes the relative position between the CF and the backend. The laser cutter cuts off the CF. Two image processing algorithms are implemented to align the CF with the support shanks and circuit connection pads. Main results. The machine was capable of precisely handling 6.8 μm carbon fiber electrodes (CFEs). Each electrode was placed into a 12 μm wide trenches in a silicon support shank. Two HDCF arrays with 16 CFEs populated on 3 mm shanks (with 80 μm pitch) were fully assembled. Impedance measurements were found to be in good agreement with manual assembled arrays. One HDCF array was implanted in the motor cortex in an anesthetized rat and was able to detect single unit activity. Significance. This machine can eliminate the manual labor-intensive handling, alignment and placement of single CF during assembly, providing a proof-of-concepts towards fully automated HDCF array assembly and batch production.
Effects of disorder on deformation and failure of brittle porous materials
Authors: Ritter Jonas , Shegufta Shucheta , Zaiser Michael
Published: May 2023

The mechanical behavior of porous materials depends strongly on porosity and pore geometry, but also on morphological parameters characterizing the spatial arrangement of pores. Here we use bond-based peridynamics to study effects of disorder on the deformation and failure behavior of brittle porous solids both in the quasi-static limit and in case of dynamic loading scenarios. We show that structural disorder, which has a strong influence on stiffness, strength and toughness in the quasi-static limit, becomes less relevant under dynamic loading conditions.
Phase transitions for countable state 1D SOS model with external field
Authors: Khakimov Otabek
Published: May 2023

We consider a 1D solid-on-solid (SOS) model with external field in which the single-spin space is the set of all integers. Then, we construct a Gibbs specification for the model and get a functional equation such that every positive solution defines an infinite volume Gibbs measure. We show that there exist infinitely many Gibbs measures for the 1D SOS model with external field for some values of parameters θ and θ
1 (the last one is responsible to the external field). Moreover, by the main theorem, we conclude that a phase transition occurs for the 1D SOS model with external field and there is no Gibbs measure for the 1D SOS model without an external field.
Symmetric exclusion process under stochastic power-law resetting
Authors: Mishra Seemant , Basu Urna
Published: May 2023

We study the behaviour of a symmetric exclusion process in the presence of non-Markovian stochastic resetting, where the configuration of the system is reset to a step-like profile at power-law waiting times with an exponent α. We find that the power-law resetting leads to a rich behaviour for the currents, as well as density profile. We show that, for any finite system, for α < 1, the density profile eventually becomes uniform while for α > 1, an eventual non-trivial stationary profile is reached. We also find that, in the limit of thermodynamic system size, at late times, the average diffusive current grows

∼

t
θ

with

θ
=
1

/

2

for

α
⩽
1
/
2

,

θ
=
α

for

1

/

2
<
α
⩽
1

and θ = 1 for α > 1. We also analytically characterize the distribution of the diffusive current in the short-time regime using a trajectory-based perturbative approach. Using numerical simulations, we show that in the long-time regime, the diffusive current distribution follows a scaling form with an

α
−

dependent scaling function. We also characterise the behaviour of the total current using renewal approach. We find that the average total current also grows algebraically

∼

t

ϕ

where

ϕ
=
1

/

2

for

α
⩽
1

,

ϕ
=
3

/

2
−
α

for

1
<
α
⩽
3

/

2

, while for

α
>
3

/

2

the average total current reaches a stationary value, which we compute exactly. The standard deviation of the total current also shows an algebraic growth with an exponent

Δ
=

1
2

for

α
⩽
1

, and

Δ
=
1
−

α
2

for

1
<
α
⩽
2

, whereas it approaches a constant value for α > 2. The total current distribution remains non-stationary for α < 1, while, for α > 1, it reaches a non-trivial and strongly non-Gaussian stationary distribution, which we also compute using the renewal approach.
Numerical optimization of billet diameter in the wide-spread and split extrusion process
Authors: Wang Ruilong , Lei Tongfei , He Xinxin , Jin Weiwen
Published: May 2023

The research object was the wide-spread shunt extrusion production of large-diameter thick-walled AZ31 magnesium alloy pipe with 360mm outer diameter and 10mm wall thickness. Based on the DEFORM-3D finite element software platform, the simulation study on the influence of billet diameter on extrusion pressure was carried out to provide theoretical support for the reasonable selection of equipment tonnage. The results show that the peak extrusion pressure increases with the increase of billet diameter, and the increasing speed is accelerated. By reducing the billet diameter, the peak extrusion pressure can be gradually reduced from 4800 tons to 2200 tons, and the maximum extrusion cargo can be saved by more than 50%. If 3600 tons extruder is used, the billet diameter should be less than 325mm; If 2500 tons extruder is used, the billet diameter should be less than 285mm.
Aerodynamic parameter calculation and ballistic stability research of special projectile
Authors: Jiang Bin’an , Zhang Hang
Published: May 2023

Based on the aerodynamic layout of special projectiles, a targeted aerodynamic parameter solution algorithm is built by a mechanical analysis model. The simulation software is used to analyze the ballistic stability. The results show that the aerodynamic layout with the center of gravity moving down is helpful to overcome the rolling interference in uncontrolled flight.
First-Principles Study on IMC Formation and Interface Failure of Electronic Packaging Solder Joints
Authors: Fu Ruyi , Huang Wei , Pan Kailin , Pi Jinzhi , Zhang Jian
Published: May 2023

At present, Sn-3.0Ag-0.5Cu (SAC305) solder is one of the commonly used lead-free solders, and copper-clad laminate is the commonly used PCB substrate. SAC solder and copper substrate mainly generate two intermetallic compounds (IMCs) of Cu6Sn5 and Cu3Sn during the soldering process. Based on the first principles, this paper analyzes the formation difficulty of the two kinds of IMCs generated in the soldering, and the failure mechanism of the Sn/IMC and IMC/Cu interfaces. Firstly, based on the density functional theory (DFT), the “CASTEP” module in Material Studio (MS) is used to analyze the formation difficulty of the two IMCs from the point of the density of states, population analysis, and energy. The results show that Cu6Sn5 is easier to generate, which also explains the reason for the first generation of Cu6Sn5 in the initial stage of soldering. Then, Sn / IMC and IMC / Cu interfaces were established in MS, and the reason why solder joint failure mainly occurred at the Sn / IMC interface was explained by energy analysis.
State of health estimation for lithium-ion battery based on improved support vector regression
Authors: Cao Chenghu , Xu Xiaohong , Ma Qiuxiang , Yang Zehua , Zheng Weiguang
Published: May 2023

The lithium-ion battery has grown to be one of the most popular types of energy storage because of its many great qualities. However, the state of health (SOH) of the lithium-ion battery decreases as the number of cycles increases, resulting in reduced performance or even failure of the device, so an accurate SOH is essential for the safe operation of the device. To solve the issue of existing estimate methods' low estimation accuracy, a SOH estimation approach based on improved support vector regression is proposed. Firstly, the changes in battery characteristics during charging and discharging are analyzed and the health factors characterizing the SOH degradation are extracted. Pearson and Spearman correlation coefficients are used to quantitatively analyze the correlation between SOH and health factors. In addition, by optimizing the kernel function parameters of the SVR model by IALO, the improved ant lion optimization and support vector regression (IALO-SVR) based SOH estimation technique was developed. The IALO-SVR method was validated with the NASA battery dataset, and the experimental results showed that the method can estimate SOH more accurately compared with Back Propagation Neural Network (BP) and ALO-SVR methods, with an estimation error of no more than 1.8% at most.
Algorithm design and optimization of profile cutting problem based on 0-1 knapsack algorithm
Authors: Zhao Qing , Ren Xiaolong
Published: May 2023

According to a one-dimensional multi-objective profile cutting machine tool and based on the principle of 0-1 knapsack algorithm and MATLAB software programming, the length of the two kinds of type and a limited number of profiles are processed to solve the maximum utilization of the profile cutting scheme, and optimize the programming algorithm for solving profile maximum cutting length, from two aspects of time complexity and space complexity analysis and comparison. Firstly, the principle of the 0-1 knapsack algorithm is used to design the algorithm to get the maximum cutting length of the corresponding two lengths. Secondly, according to the number of profiles, cutting margin and other parameters are used to select the length type of profiles. Then, the cutting size sequence of each selected profile is introduced, and the length type, quantity, cutting size sequence group, total cutting margin, profile utilization rate, and other parameters are calculated when the processing contract is completed. Finally, based on the recursive formula of jump point sequence, the algorithm is optimized to eliminate the restriction of 0-1 knapsack algorithm by integer constraints, reduce the time and space complexity of the algorithm, reduce the calculation amount and storage space of the algorithm, and improve the efficiency of the programming algorithm.
Design of high quantum efficiency SPAD single-photon detector based on metasurface
Authors: Xu Liangqiang , Feng Guilan , Huang Shanyan , Pan Jinlv , Zhao Tianqi
Published: May 2023

This work discusses several metasurface structure types, their manufacturing processes, and the design and simulation of nanopyramid arrays, square slot arrays, and funnel arrays to improve absorption. In particular, a silicon-based continuous thin gold film-covered deep grooved thin metal structure was constructed and examined. It surpasses the silicon materials’ absorption thresholds, considerably expanding the NIR’s absorption range to 2000 nanometers. More information is provided regarding the impact of trench depth on cavity pattern and near-infrared absorption. Its preparation process is detailed, and its compatibility with SPAD single-photon detectors is confirmed. This information is likely to encourage the use of SPAD in domains such as near-infrared optical communication and other low-light detecting technologies.
Design and simulation analysis of electric needleless syringe
Authors: Cheng Simian
Published: May 2023

A new design of a needleless syringe based on a moving-coil electromagnetic linear actuator drive is proposed to address the problems of the uncontrollable driving force and bulky structure commonly found in current commercial needleless syringes. The structural parameters of the moving-coil electromagnetic linear actuator with the electromagnetic driving force at different current strengths are obtained using the finite element analysis method. The results of jet stagnation pressure and jet velocity were obtained by MATLAB numerical calculation and CFD jet simulation. The process of 0.1 ml drug diffusion under the skin at a current size of 40 A was simulated. The results show that the jet stagnation pressure at the nozzle is 32 MPa, the jet velocity is 246 m/s, and the jet diffusion depth reaches 15 mm under the maximum driving force condition. The output electromagnetic force of the moving-coil electromagnetic linear actuator in this scheme is proportional to the current’s magnitude, and the actuator’s small size allows it to be used as a driving component of a hand-held needleless syringe.
Simulation and Optimization of Five-axis NC Machining of Integral Impeller Based on Improved Particle Swarm Optimization
Authors: Duan Xiangmin , Zhang Chun , You Si kai
Published: May 2023

The traditional impeller processing generally adopts the method of casting and polishing, which makes the impeller die manufacturing complicated. The blade precision is difficult to guarantee, the dynamic balance performance is poor, and the production cycle is long. Five-axis machining technology makes full use of the best cutting point of the tool or further optimizes the pose angle of the tool and workpiece to cut, so as to obtain higher cutting efficiency and better-machined surface quality. In the simulation experiment, it can be concluded that the proposed method can achieve convergence after 110 iterations. The substructure coupling method and response surface method converge after 150 iterations and 140 iterations respectively. Compared with the analysis results, this method can be applied to the optimization of NC machining parameters, because it adopts the adaptive decreasing method of inertia weight to improve PSO(Particle swarm optimization), which has a fast convergence speed and can quickly obtain the global optimal solution. Through the improved PSO, the optimal solution of the objective function of NC machining parameters is obtained, the optimization of NC machining parameters is realized, and the superiority and feasibility of the optimization of NC machining parameters are improved.
Characterization of AlN thin film piezoelectric coefficient d31 using Piezoelectric Micromachined Ultrasonic Transducers (PMUTs)
Authors: Zhang Zhenghu , Zhang Linwei , Wu Zhipeng , Gao Mingze , Lou Liang
Published: May 2023

The transverse piezoelectric coefficients d
31 of piezoelectric membranes is fundamental to the design, simulation, optimization, and applications of piezoelectric devices using Aluminum Nitride (AlN). In this work, a method based on the inverse piezoelectric effect is proposed to characterize d
31. Based on the piezoelectric equation and the thin film vibration equation, the central displacement of the Piezoelectric Micromachined Ultrasonic Transducers (PMUTs) is linearly related to the DC voltages when the PMUTs are in the linear operating region. The central displacement of PMUTs is measured by 3D Measuring Laser Microscope at various DC voltages. The finite element method (FEM) is combined with change of d
31 to approximate the relationship between displacement and voltage. Then, The proposed method is verified for its accuracy through the use of the cantilever technique where the cantilever is fabricated on the same wafer as the above PMUTs. The d
31 of the AlN thin film obtained by the proposed method and the cantilever method are -1.58pC/N and -1.60pC/N. The error of the two methods is within 2%. Ultimately, the extraction and measurement of d
31 can be achieved by the proposed method.
The record-breaking 2022 long-lasting marine heatwaves in the East China Sea
Authors: Oh Hyoeun , Kim Go-Un , Chu Jung-Eun , Lee Keunjong , Jeong Jin-Yong
Published: May 2023

In 2022, record-breaking long-lasting marine heatwaves (MHWs) occurred in the East China Sea (ECS), which persisted for 62 d during boreal summer. This exceeded the average MHWs duration of 10 d by a factor of 6. In addition, 2022 was also recorded as a year of many extreme events throughout Asia, such as summer floods in China and Pakistan, droughts and extreme heat in Europe, raising the question of whether they were caused by a ‘triple-dip’ La Niña, which has persisted since September 2020. Here we examine the key local and remote processes that led to the 2022 MHWs in the ECS using mixed-layer heat budget analysis. During the onset of the MHWs, a salinity-stratified shallow mixed-layer due to the large river discharge from the Yangtze–Huaihe River floods in June created favorable conditions for warm ocean temperature in the ECS. Simultaneously, an anomalous anticyclone maintained by the stationary Rossby wave, which is generated by vorticity forcings in mid-latitudes and thermal forcing in Pakistan, settled in the corresponding region and led to the long-lasting MHWs until Typhoon Hinnamnor began to dissipate the wave in early September. This study improves our understanding of the physical mechanism of flood-related MHWs that have increased with recent climate change.
Global drivers of local water stresses and global responses to local water policies in the United States
Authors: Haqiqi Iman , Bowling Laura , Jame Sadia , Baldos Uris , Liu Jing , Hertel Thomas
Published: May 2023

The rapid depletion of US groundwater resources and rising number of dying wells in the Western US brings attention to the significance of groundwater governance and sustainability restrictions. However, such restrictions on groundwater withdrawals are likely to generate spillover effects causing further environmental stresses in other locations and adding to the complexity of sustainability challenges. The goal of this paper is to improve our understanding of the implications of growing global food demand for local sustainability stresses and the implications of local sustainability policies for local, regional, and global food production, land use, and prices. We employ SIMPLE-G-US (Simplified International Model of agricultural Prices, Land use, and the Environment—Gridded version for the United States) to distangle the significance or remote changes in population and income for irrigation and water resources in the US. Then we examine the local-to-global impacts of potential US groundwater sustainability policies. We find that developments in international markets are significant, as more than half of US sustainability stresses by 2050 are caused by increased commodity demand from abroad. Furthermore, a US sustainable groundwater policy can cause overseas spillovers of US production, thereby potentially contributing to environmental stresses elsewhere, even as groundwater stress in the US is alleviated. These unintended consequences could include deforestation due to cropland expansion, as well as degradation in water quality due to intensification of production in non-targeted areas.
Reaction diffusion systems and extensions of quantum stochastic processes
Authors: Greenman Chris D
Published: May 2023

Reaction diffusion systems describe the behaviour of dynamic, interacting, particulate systems. Quantum stochastic processes generalise Brownian motion and Poisson processes, having operator valued Itô calculus machinery. Here it is shown that the three standard noises of quantum stochastic processes can be extended to model reaction diffusion systems, the methods being exemplified with spatial birth–death processes. The usual approach for these systems are master equations, or Doi-Peliti path integration techniques. The machinery described here provide efficient analyses for many systems of interest, and offer an alternative set of tools to investigate such problems.
Antibacterial coating of corona treated Poly(lactic acid) / Poly(butylene succinate) film with Chitosan and Zinc oxide nanoparticle
Authors: Hongsriphan N , Nualyung J , Yaothaisong N , Patanathabutr P
Published: May 2023

The biodegradable PLA/PBS 90/10 wt% films were extruded and surface treated with corona discharge. Two electrical inputs of the corona treatment were used, 2 or 6 amperes, which the change of the surface tension was evaluated using corona measuring pens. The blend films were coated with the antibacterial mixture between chitosan and zinc oxide nanoparticles (ZnO-NP) in four concentrations: 1.0/0.4, 1.0/0.5, 1.5/0.5, and 1.5/0.5 wt%/wt%. This film could be used to replace transparent disposable packaging in the circular economy. It was found that the surface tension of the blend film was 30 dyne (mN/m) which was much like the neat PLA due to PLA being the main composition. Since the overall coated film thickness was kept constant, there was no significant difference in the coating weight among four coating concentrations. Compared to the uncoated PLA/PBS film, the tensile strength of the coated films tended to be higher with the increase of ZnO-NP content. However, the elongation at break of the coated films decreased significantly, which the stiffer coating layers became the stress concentrators. From SEM, it was seen that the good adhesion between the polymer and the coating layer was achieved. When the coated films were torn apart in the trouser tear testing, the failure was the breakage of the blend film with there was some coating layer delaminated.
Optimization of microwave-assisted biodiesel production using Iron (III) oxide - Calcium oxide / Activated charcoal derived from waste Asian green mussel shell as heterogeneous catalyst
Authors: Loryuenyong V , Kaewmanee S , Rattanawaraporn S , Chimplenapanon N , Buasri A
Published: May 2023

The primary objective of this study was to produce a heterogeneous iron (III) oxide (Fe2O3)-calcium oxide (CaO)/activated charcoal (AC) catalyst from Asian green mussel shell utilizing wet impregnation and calcination processes for biodiesel synthesis. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and the Brunauer-Emmett-Teller (BET) method were used to analyze the novel catalyst. Using a central composite design (CCD)-based response surface methodology (RSM), the process parameters such as catalyst quantity, reaction time, and microwave electrical power were optimized. The optimal reaction conditions were determined to be 1.07 wt.% of Fe2O3-CaO/AC, 6.42 min of reaction time, and 667 W of microwave electrical power. The published results imply that the heterogeneous catalyst has a great potential for the direct conversion of waste frying oil (WFO) to biodiesel, with the ability to reuse without reactivation. The development of Fe2O3-CaO/AC as a novel heterogeneous catalyst would facilitate the manufacture of biodiesel in an eco-friendly manner.
Effects of Lignocellulose Contents in Bamboo Charcoal on Mechanical and Thermal Properties of Polybenzoxazine-based Friction Materials
Authors: Jantapanya N , Jubsilp C , Mora P , Kaewluan S , Srisorrachat S , Rimdusit S
Published: May 2023

The objective of this research is to study mechanical and thermal properties of polybenzoxazine-based friction materials (PFMs) filled with 10 wt% bamboo charcoal particles (BC) containing residual lignocellulose content of 0-10wt% (BC0-10%), 10-20wt% (BC10-20%) and 20-30wt% (BC20-30%). The PFMs filled with synthetic graphite particles was also prepared to compare the properties. The obtained results showed that the mechanical properties, i.e., flexural strength and flexural modulus of the PFMs were improved with an increase of the residual lignocellulose content, and tended to be higher than that of the PFMs filled with synthetic graphite particles. Thermal stability monitored by the degradation temperature at 5% weight loss (Td5) of the PFMs revealed a decrease with an increasing residual lignocellulose content in BC. However, the Td5 of the PFMs filled with BC is still higher than the generated heat during the braking, which has temperatures around 350 °C. The results suggested that the obtained composite material is a promising candidate for car brake pads.
Synthesis and characterization of calcium carbonate/carbon from water lettuce via hydrothermal carbonization process
Authors: Chaiammart N , Thu M M , Srisuk N , Mueanpun N , Panomsuwan G
Published: May 2023

The conversion of biomass into value-added products has recently received much attention for a broad range of applications. In this work, water lettuce was converted into calcium carbonate (CaCO3)/carbon via hydrothermal carbonization (HTC) and pyrolysis at 900 °C. The HTC temperature and time varied in the range of 160–200 °C for 6–18 h, respectively. X-ray diffraction analysis indicated that the samples consisted of a mixture of calcite and vaterite phases of CaCO3 and amorphous carbon. The ratio of calcite and vaterite phases varied with HTC time. The Fourier transform infrared spectroscopy (FTIR) result showed the characteristic absorption bands confirming the presence of CaCO3. Scanning electron microscopy (SEM) images revealed the large crystal of CaCO3 and fine carbon particles. From the N2 sorption analysis, the sample prepared from the HTC at 200 °C for 6 h had the highest specific surface area of 95 m2/g due to the development of micropores. The results presented in this work demonstrated that both HTC temperature and time play critical roles in altering the surface area and phase structure of CaCO3/carbon. The CaCO3/carbon derived from water lettuce can potentially be used and adapted for many applications.
Dry Electropolishing of Laser Powder Bed Fusion Manufactured Cobalt-chrome
Authors: Rautio T , Jaskari M , Päkkilä J , Järvenpää A
Published: May 2023

Cobalt-chrome (Co-Cr) has been used extensively in medical applications, gas turbines and dental products for decades now. Laser powder bed fusion (PBF-LB) manufacturing is very suitable for small series and prototyping and in this regard its application to dental products is promising as they are usually unique and high precision is required. One major factor limiting the application of the PBF-LB technique is the surface quality, which is not adequate in as built condition. This work focuses on improving the surface quality of the PBF-LB manufactured Co-Cr with dry electropolishing so that it is suitable for dental bridges. The surface quality is analysed using laser scanning microscopy for surface roughness, surface profile and topography to reveal the surface characteristics after the printing and the effect of dry electropolishing is highlighted. The results showed that dry electropolishing can be used successfully to improve the surface quality for the needs of dental bridges. Final product quality was verified by a dentist, and the dental bridge could be used on a patient.
Preparation and Properties of Carboxymethyl Cellulose / β-Cyclodextrin Hydrogel
Authors: Panyakaew N , Thongpin C , Hemsri S
Published: May 2023

Carboxymethyl cellulose (CMC) based hydrogels provide superabsorbent properties but show low mechanical properties. In order to overcome this problem, β-cyclodextrin (CD) is added to improve the mechanical strength of hydrogels. Moreover, CD-containing hydrogels have the potential to encapsulate antimicrobial essential oils or drugs and give a sustained release for medical applications to treat a variety of bacterial infectious diseases causing destruction to human health. In this work, the CMC/CD hydrogels were prepared by using epichlorohydrin as a chemical crosslinking agent. The objective of this research was to study the effect of the CMC/CD weight ratio at 6:1, 7:1, and 8:1 on morphology, mechanical properties and swelling ratio in water of the CMC/CD hydrogels compared with CMC hydrogel. The weight ratio of epichlorohydrin and CMC/CD was constant at 6:1. The morphology analysis of the CMC/CD hydrogels showed an irregular porous structure with the presence of -like structure. The addition of CD content led to an increase in compressive strength whereas the swelling ratio of the hydrogel decreased. The CMC/CD hydrogel at weight ratio of 7:1 provided the highest compressive strength and also retained swelling ability.
Microwave-assisted green synthesis of silver nanoparticles using extract of mint leaves
Authors: Thanasakonpong A , Ksapabutr B , Panapoy M
Published: May 2023

Silver nanoparticles are widely used in areas such as biosensing, hydrogen production, electronics, photovoltaics, antimicrobials, and biomedical engineering applications. Biological synthesis is regarded as a safe and non-toxic process, but its main disadvantage is the slow processing time. The mint leaf extract can act as both a reducing and stabilizing agent for the biological synthesis of silver nanoparticles. In this work, a rapid and green method for the microwave-assisted biological synthesis of silver nanoparticles was investigated using an aqueous leaf extract of mint as a biosource of cost-effective, non-hazardous reducing and stabilizing agents. The optimum conditions for microwave extraction of mint leaves were 220 s at 800 W and a 5 g/L mint-to-water ratio. Meanwhile, the optimal conditions for the biological synthesis of silver nanoparticles were as follows: concentration of silver nitrate solution = 2 mM, microwave reaction time = 100 s at 800 W, and pH = 8. The silver nanoparticles obtained by the microwave heating process showed a surface plasmon band centered at 420 nm with a higher peak height than those prepared by the conventional heating process. Dynamic light scattering analysis has shown the synthesized silver nanoparticles to have an average diameter of 54 nm.
Effects of fiber surface modification on mechanical properties of short pineapple leaf fiber-carbon black reinforced natural rubber hybrid composites
Authors: Thaiwattananon S , Thanawan S , Amornsakchai T
Published: May 2023

At present, the world is focusing on the circular economy by turning waste into production resources again, reducing waste generation, and making it circulate in the system. This research focuses on using agricultural waste, which is pineapple leaves abundant in Thailand, to be processed into pineapple leaf fibers (PALF) and used to reinforce natural rubber. PALF has relatively high strength when compared to other natural fibers. On the other hand, the challenge of using PALF to reinforce natural rubber is the difference in the polarity of the fibers and rubber matrix. Thus, surface modification of PALF was studied to enhance the adhesion between the fiber surface and the matrix. Four systems were compared, i.e., untreated PALF, alkaline-treated, silane69-treated, and aminosilane-treated PALF. A unidirectional fiber-reinforced natural rubber composites were prepared with fixed fiber and carbon black contents of 10 and 30 phr, respectively. Mechanical properties of the composites were determined by tensile test and morphology was observed by scanning electron microscope (SEM). It was found that silane69-treated and aminosilane-treated PALF could reinforce the rubber matrix over the entire strain. However, silane69-treated and aminosilane-treated PALF had lesser reinforcement effect than alkaline-treated PALF at low strains. Despite a clear change in mechanical behavior, SEM could not tell the difference or changes that occur at the interface. Fiber surface modifications with silane69 and aminosilane have the potential to be further developed to improve properties of natural rubber composites and will, hopefully, increase the value of rubber products for Thailand industry.
Superconductivity in type II layered Weyl semi-metals
Authors: Rosenstein B , Ya Shapiro B
Published: May 2023

Novel ‘quasi 2D’ typically layered (semi)metals offer a unique opportunity to control the density and even the topology of electronic matter. In intercalated MoTe
2 type II Weyl semi-metal the tilt of the dispersion relation cones is so large that topologically the Fermi surface is distinct from a more conventional type I. Superconductivity observed recently in this compound (Zhang et al 2022 2D Mater.
9 045027) demonstrated two puzzling phenomena. The gate voltage has no impact on critical temperature,

T

c

,

in a wide range of density, while it is very sensitive to the inter-layer distance. A phonon theory of pairing in a layered Weyl material including the effects of Coulomb repulsion is constructed, which explains the above two features in MoTe
2. The first feature turns out to be a general one for any type II topological material, while the second reflects properties of the intercalated materials affecting the Coulomb screening.
Confined-state physics and signs of fermionization of moiré excitons in WSe2/MoSe2 heterobilayers
Authors: Lohof F , Michl J , Steinhoff A , Han B , von Helversen M , Tongay S , Watanabe K , Taniguchi T , Höfling S , Reitzenstein S , Anton-Solanas C , Gies C , Schneider C
Published: May 2023

We revisit and extend the standard bosonic interpretation of interlayer excitons (ILX) in the moiré potential of twisted heterostructures of transition-metal dichalcogenides. In our experiments, we probe a high quality MoSe2/WSe2 van der Waals bilayer heterostructure via density-dependent photoluminescence spectroscopy and reveal strongly developed, unconventional spectral shifts of the emergent moiré exciton resonances. The observation of saturating blueshifts of successive exciton resonances allow us to explain their physics in terms of a model utilizing fermionic saturable absorbers. This approach is strongly inspired by established quantum-dot models, which underlines the close analogy of ILX trapped in pockets of the moiré potential, and quantum emitters with discrete eigenstates.
Ultrafast-programmable two-dimensional p–n homojunction for high-performance photovoltaics and optoelectronics
Authors: Wang Hao , Wu Kang , Guo Hui , Gao Hui , Liu Li , Wu Liangmei , Chen Jiancui , Yang Haitao , Bao Lihong , Gao Hong-Jun
Published: May 2023

Two-dimensional (2D) materials are considered to be promising candidates for constructing revolutionary electronic devices. However, difficulties in controlling the polarity, concentration, and spatial distribution of charge carriers in 2D materials make the construction of 2D p–n junctions rather challenging. Here, we report the successful construction of ultrafast-programmable 2D p–n homojunctions with a semi-floating-gate configuration based on a vertically stacked molybdenum disulfide (MoS2)/hexagonal boron nitride/multilayer graphene van der Waals heterostructure. By partially electrostatically doping the MoS2 channel under different control-gate voltage pulses, three types of 2D homojunctions, including p–n, n+–n, and n–n, can be constructed. The 2D p–n homojunction can be programmed at an ultrafast speed of within 160 ns and exhibits a large rectification ratio of ∼104. Based on a modified Shockley equation, an ideality factor of ∼2.05 is extracted, indicating that the recombination process dominated the transport mechanism. The MoS2 2D p–n homojunction shows a maximum electrical power conversion efficiency of up to 2.66% under a weak light power of 0.61 nW and a high photovoltage responsivity of 5.72 × 109 V W−1. These results indicate that the ultrafast-programmable 2D p–n homojunction has great potential for use in high-performance photovoltaics and optoelectronics.
Suppression of hot electron effect in AlGaN/GaN HEMT with multi-grooves barrier-etched structure
Authors: Li Xuanlin , Xu Jie , Liu Weijing
Published: May 2023

A multi-grooves barrier-etched structure between barrier layer and passivation layer is proposed in this paper to suppress the hot electron effect at the gate edge on the drain side in the p-GaN gate AlGaN/GaN high-electron-mobility transistor. In the TCAD simulations, the groove structure induces extra electric field concentration region and AlGaN/SiN interface area, which can lower the high electric field peak and electron temperature in the channel at the gate edge, leading to the alleviated capture and release of hot electrons. The static I–V characteristic and dynamic switching performance and breakdown characteristic show that the multi-grooves barrier-etched structure improves the current collapse and switching time and breakdown voltage. Our work exhibits the great potential of multi-grooves barrier-etched structure on the stability and reliability of the AlGaN/GaN HEMT.
Effect of isothermal annealing temperature on microstructure and mechanical properties of Cu45Zr45Ag7Al3 amorphous alloy
Authors: Zhang Like , Liu Limei , Zhang Rong , Chen Ding , Ma Guozhi , Ye Chuangen
Published: May 2023

Bulk amorphous alloys, as a material with broad application prospects, are highly expected in many cutting-edge applications. However, its plastic deformation relies on highly localized shear bands, resulting in brittle fracture characteristics of materials with low plastic strain as a whole. Therefore, strengthening and toughening of amorphous alloys is one of the key topics in the research of amorphous applications. In this paper, the effects of different isothermal annealing temperature on the microstructure and uniaxial compression properties of Cu45Zr45Ag7Al3 amorphous alloy were studied by means of differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that Cu10Zr7, AlCu2Zr, Cu8Zr3 and Al2Zr phases precipitated successively from the amorphous alloy matrix with the increase of annealing temperature, and the fracture strength and plastic strain increased first and then decreased; At an isothermal annealing temperature of 741 K, the precipitated nanocrystalline Cu10Zr7 phase can improve the fracture strength of the alloy; when the annealing temperature rises to 746 K, the strength of the alloy decreases slightly, but the plasticity increases; with the continuous increase of annealing temperature, the plasticity of the alloy decreases and the strength continues to increase; As the annealing temperature continues to increase, the fracture strength of the alloy decreases, exhibiting significant brittle fracture characteristics.
A simple approach to determine loss of physiological complexity in heart rate series
Authors: Ozel Hasan Fehmi , Kazdagli Hasan
Published: May 2023

There are several ways to assess complexity, but no method has yet been developed for quantitatively calculating the ‘loss of fractal complexity’ under pathological or physiological states. In this paper, we aimed to quantitatively evaluate fractal complexity loss using a novel approach and new variables developed from Detrended Fluctuation Analysis (DFA) log-log graphics. Three study groups were established to evaluate the new approach: one for normal sinus rhythm (NSR), one for congestive heart failure (CHF), and white noise signal (WNS). ECG recordings of the NSR and CHF groups were obtained from PhysioNET Database and were used for analysis. For all groups Detrended Fluctuation Analysis scaling exponents (DFAα
1, DFAα
2) were determined. Scaling exponents were used to recreate the DFA log-log graph and lines. Then, the relative total logarithmic fluctuations for each sample were identified and new parameters were computed. To do this, we used a standard log-log plane to standardize the DFA log-log curves and calculated the differences between the standardized and expected areas. We quantified the total difference in standardized areas using parameters called dS1, dS2, and TdS. Our results showed that; compared to the NSR group, DFAα
1 was lower in both CHF and WNS groups. However, DFAα
2 was only reduced in the WNSgroup and not in the CHFgroup. Newly derived parameters: dS1, dS2, and TdS were significantly lowerin the NSR group compared to the CHF and WNS groups. The new parameters derived from the DFA log-log graphs are highly distinguishing for congestive heart failure and white noise signal. In addition, it may be concluded that a potential feature of our approach can be beneficial in classifying the severity of cardiac abnormalities.
A computer-aided tool for automatic volume estimation of hematoma using non-contrast brain CT scans
Authors: Nag Manas K , Koley Subhranil , Sadhu Anup K , Dutta Pranab K , Holsouser Barbara , Ashwal Stephen , Ghosh Nirmalya
Published: May 2023

The computation of hematoma volume is the key parameter for treatment planning of Intracerebral hemorrhage (ICH). Non-contrast computed tomography (NCCT) imaging is routinely used for the diagnosis of ICH. Hence, the development of computer-aided tools for three-dimensional (3D) computed tomography (CT) image analysis is essential to estimate the gross volume of hematoma. We propose a methodology for automatic estimation of the hematoma volume from 3D CT volumes. Our approach integrates two different methods, multiple abstract splitting (MAS) and seeded region growing (SRG) to develop a unified hematoma detection pipeline from pre-processed CT volumes. The proposed methodology was tested on 80 cases. The volume was estimated from the delineated hematoma region, validated against the ground-truth volumes, and compared with those obtained from the conventional ABC/2 approach. We also compared our results with the U-Net model (supervised technique) to show the applicability of the proposed method. The volume calculated from manually segmented hematoma was considered the ground truth. The R
2 correlation coefficient between the volume obtained from the proposed algorithm and the ground truth is 0.86, which is equivalent to the R
2 value resulting from the comparison between the volume calculated by ABC/2 and the ground truth. The experimental results of the proposed unsupervised approach are comparable to the deep neural architecture (U-Net models). The average computation time was 132.76 ± 14 seconds. The proposed methodology provides a fast and automatic estimation of hematoma volume, which is similar to the baseline user-guided ABC/2 approach. Implementation of our method does not demand a high-end computational setup. Thus, recommended in clinical practice for computer-assistive volume estimation of hematoma from 3D CT volumes and can be implemented in a simple computer system.