bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature-dependent effect of modulation in graphene-supported metamaterials
Authors: Morozov Yevhenii M , Lapchuk Anatoliy S , Protsak Iryna S , Kryuchyn Andriy A , Nevirkovets Ivan P 
Published: March 2022

Abstract
We report on a novel effect of temperature-dependent modulation in graphene-supported metamaterials. The effect was observed during the theoretical analysis of a model graphene-supported electro-optical modulator having silicon dioxide (SiO2) or hafnium dioxide (HfO2) as a buffer dielectric layer. Comparative analysis of the two materials showed that they provide approximately the same maximum values for transmission and reflection modulation depths. However, in the case of a HfO2 buffer layer, a lower chemical potential of the graphene is required to achieve the maximum value. Moreover, theoretical calculations revealed that a lower gate voltage (up to 6.4 times) is required to be applied in the case of a HfO2 layer to achieve the same graphene chemical potential. The graphene layer was found to possesses high absorption (due to the additional resonance excitation) for some values of chemical potential and this effect is extremely temperature dependent. The discovered modulation effect was demonstrated to further increase the transmission modulation depth for the simple model structure up to 2.7 times (from 18.4% to 50.1%), while for the reflection modulation depth, this enhancement was equal to 2.2 times (from 24.4% to 52.8%). The novel modulation effect could easily be adopted and applied over a wide range of metadevices which would serve as a quick booster for the development of related research areas.
Topological nodal line semimetal in an all-sp
2 monoclinic carbon
Authors: Khan Muhammad Rizwan , Bu Kun , Wang Jian-Tao 
Published: March 2022

Abstract
Topological nodal line semimetal is an exotic class of quantum materials featuring the continuous line of nodes inside the first Brillouin zone. Here we identify by systematical ab initio calculations a new all-sp
2 hybridized carbon allotrope with monoclinic C2/c

(

C

2
h

6

)

symmetry which is termed as bcm-C16. Total energy calculations show that our proposed bcm-C16 carbon is energetically comparable to or stable than the previously proposed bco-C16, bct-C16, and oP16 carbon. Its dynamical stability has been confirmed by phonon mode calculations. Detailed analysis of the electronic properties show that bcm-C16 carbon is a topological nodal line semimetal with a single closed nodal ring around the Γ high symmetric point, protected by spatial inversion

(

P

)

and time-reversal

(

T

)

symmetry. When the nodal ring is projected onto the (001) surface, a topologically protected drumhead-like surface state can be seen inside or outside the nodal ring depending on the different surface terminations. Moreover, we also examined the tensile-strain robustness of the electronic properties of bcm-C16 carbon. The nodal ring is robust under a tensile-strain along the crystalline x- and z-directions up to 20%. In addition, the simulated x-ray diffraction pattern (XRD) of bcm-C16 carbon matches with the experimental pattern found in the detonation and chimney soot experiment. The present proposal has enriched the family of carbon allotropes with topological nodal lines, and pave the way for further theoretical and experimental studies.
Studying the potential of QQq at finite temperature in a holographic model *
Authors: Chen Xun , Yu Bo , Chu Peng-Cheng , Li Xiao-hua 
Published: March 2022

Abstract
Using gauge/gravity duality, we investigate the string breaking and dissolution of two heavy quarks coupled to a light quark at finite temperature. It is found that three configurations of QQqexist with the increase in separation distance for heavy quarks in the confined phase. Furthermore, string breaking occurs at the distance

(

) for the decay mode

. In the deconfined phase, QQq melts at a certain distance and then becomes free quarks. Finally, we compare the potential of QQq with that of

, and it is found that

is more stable than QQqat high temperatures.
A data-driven methodological routine to identify key indicators for social-ecological system archetype mapping
Authors: Pacheco-Romero Manuel , Vallejos María , Paruelo José M , Alcaraz-Segura Domingo , Torres-García M Trinidad , Salinas-Bonillo María J. , Cabello Javier 
Published: March 2022

Abstract
The spatial mapping of social-ecological system (SES) archetypes constitutes a fundamental tool to operationalize the SES concept in empirical research. Approaches to detect, map, and characterize SES archetypes have evolved over the last decade towards more integrative and comparable perspectives guided by SES conceptual frameworks and reference lists of variables. However, hardly any studies have investigated how to empirically identify the most relevant set of indicators to map the diversity of SESs. In this study, we propose a data-driven methodological routine based on multivariate statistical analysis to identify the most relevant indicators for mapping and characterizing SES archetypes in a particular region. Taking Andalusia (Spain) as a case study, we applied this methodological routine to 86 indicators representing multiple variables and dimensions of the SES. Additionally, we assessed how the empirical relevance of these indicators contributes to previous expert and empirical knowledge on key variables for characterizing SESs. We identified 29 key indicators that allowed us to map 15 SES archetypes encompassing natural, mosaic, agricultural, and urban systems, which uncovered contrasting land sharing and land sparing patterns throughout the territory. We found synergies but also disagreements between empirical and expert knowledge on the relevance of variables: agreement on their widespread relevance (32.7% of the variables, e.g. crop and livestock production, net primary productivity, population density); relevance conditioned by the context or the scale (16.3%, e.g. land protection, educational level); lack of agreement (20.4%, e.g. economic level, land tenure); need of further assessments due to the lack of expert or empirical knowledge (30.6%). Overall, our data-driven approach can contribute to more objective selection of relevant indicators for SES mapping, which may help to produce comparable and generalizable empirical knowledge on key variables for characterizing SESs, as well as to derive more representative descriptions and causal factor configurations in SES archetype analysis.
Theophylline extended-release monolithic matrix comprising natural rubber latex as binder
Authors: Chaiya P , Phaechamud T 
Published: March 2022

Abstract
A major component of polymer in natural rubber latex (NRL) obtained from Hevea brasiliensis consists of poly-cis-1,4-isoprene. Poly-cis-1,4-isoprene exhibited interesting physical properties suitable for possible use as a binder in pharmaceutical solid dosage forms such as monolithic matrix tablet. The aim of this study was to study the feasibility of using NRL as the binder in theophylline anhydrous (THE)-incorporated monolithic matrix tablet in comparison with polyvinyl pyrrolidone K-30 (PVP-30). Physical properties of granules and tablets fabricated with wet granulation and tableting process, in vitro drug release test and release kinetic model were investigated and compared with those prepared using PVP-K30 as a binder. THE-incorporated monolithic matrix tablet was successfully fabricated with wet granulation and tableting process using NRL or PVP-K30 as binder. Granules and tablets of monolithic matrix tablet using NRL as a binder exhibited similar physical properties to those of tablet prepared using PVP-K30 as a binder. In addition, the controlled THE release with diffusion mechanism were presented in both formulations. Surprisingly, the addition of sodium bicarbonate in THE monolithic matrix tablets employing NRL as a binder could also prolong the drug release.
Prediction of crosslink density of prevulcanised latex using NIR Spectroscopy based on combination of fractional order derivative (FOD) and variable selection methods
Authors: Lim C H , Posom J , Sirisomboon P 
Published: March 2022

Abstract
Rapid method in measurement of crosslink density is required in factory. The objective of this study was to develop the prediction model of crosslink densities based on near infrared (NIR) spectroscopy method. The prediction models were developed using partial least squares regression (PLSR) with spectral pre-treatment of fractional order derivatives (FOD) and variable selection methods including successive project algorithm (SPA) and genetic algorithm (GA). The result demonstrated that prevulcanised (PV) latex model had higher accuracy than that of PV50 latex model. Effective model in predicting crosslink densities of PV and PV50 latices could be pre-processed with FOD=1 and 0.75, respectively. The prediction model generated with full wavelength had the standard error of cross validation (SECV) of 3.21% and 3.52%, respectively. The model performance of PV latex could improve with variable selection method of GA which reduced the SECV from 3.21% to 3.17% and number of wavelengths reduced from 1059 to 937. The model performance of PV50 could not reduce by using the variable selection method. However, the GA could reduce the number of wavelengths from 1059 to 216.
Deciphering the discoloration in the manufacturing of natural rubber
Authors: Sakdapipanich J 
Published: March 2022

Abstract
Many naturally occurring color components, especially non-rubber components, are present in natural rubber (NR) latex, limiting some NR applications, particularly for light-colored NR products in high demand. Non-rubber components, like lipids and proteins, can be removed from NR to reduce its yellow color. This study looked at the factors that influence the yellow index (YI) in NR and NR latex discoloration techniques. Proteins were a crucial factor directly determining the YI of NR. Thus, increasing the number of centrifugation washings, speed, and time was used to remove proteins to minimize the YI of NR. Percentage of total solid content (% TSC) of field NR latex, the blend ratio between cream rubber and skim latex, or bottom fraction from fresh-field NR latex collected from centrifugation process, were also important factors. The addition of sodium metabisulphites as a polyphenol oxidase (PPO)-reducing agent reduced the YI significantly. The oxidative breakdown of endogenous non-rubber components at high temperatures was also confirmed to serve the increase in YI value due to air-drying conditions of NR.
Near infrared spectroscopy and machine learning classifier of crosslink density level of prevulcanized natural rubber latex
Authors: Sirisomboon P , Lim C H , Posom J 
Published: March 2022

Abstract
By toluene swell index for cross link density level of prevulcanized (PV) rubber latex knowledge, toluene swell of PV latex is measured for trading and production management. Therefore, aim of this research is to use the Fourier transform near infrared (FT-NIR) spectroscopy with machine learning to classify different cross link density levels by toluene swell index including, Unvulcanized (U) (> 160%swell), Lightly vulcanized (L) (100-160%swell), Moderately vulcanized (M) (80-100%swell), Fully vulcanized (F) (< 80%swell) of prevulcanized (PV) natural rubber latex of raw PV latex and 50% solids content PV latex (PV50). The result shows that toluene swell index of rubber prevulcanized latex could be 91.8% correct classified into L group and M group using PV50 MSC pretreated spectra with PLS-DA classifier. Unfortunately, sample obtained for this experiment were loss of U and F groups. In future, to develop the robust model, the sample of all crosslink density levels should be collected.
Study of nylon textile-reinforced natural rubber composite
Authors: Choosang N , Smitthipong W 
Published: March 2022

Abstract
This study focuses on the production of nylon-reinforced natural rubber composites. In general, technical textiles serve as reinforcement and strength materials for a wide range of applications in rubber/textile composites. The adhesion between rubber and nylon is the most important factor affecting the assembly process and the strength of the finished product. The results showed that natural rubber reinforced with nylon textiles can be efficiently prepared by splicing a single layer of nylon fabric between two layers of rubber. The nylon textile-reinforced natural rubber composite was characterized by tensile testing machines and rubber curing characteristics, etc. The main result showed that the mechanical properties of rubber/nylon composites were higher than those of pure rubber. From the experimental results, it was found that nylon fabric can strengthen the natural rubber composite material for use with car tires.
Effect of potassium oleate on chemical structure-compression relationship of natural rubber foam
Authors: Kunklang P , Smitthipong W 
Published: March 2022

Abstract
Rubber foam-based products, such as mattresses, pillows, and cushions, are becoming increasingly popular. Rubber foam's formulation is still being developed to improve the properties, because of its wide range of applications. Potassium oleate is a surfactant for producing the rubber foam, although it can be used in different concentrations to prepare the different properties of rubber foam. The Dunlop method was used in this work, due to its simplicity and easy-to-use in the foam preparation. The effect of potassium oleate, which was used as a foaming agent, was investigated in this study by reducing the amount of potassium oleate. The density, compression, and Fourier transform infrared (FTIR) spectroscopy results showed that both density and compression of foam samples with half amounts of potassium oleate are higher than those of control sample with normal amounts of potassium oleate. Moreover, the FTIR result revealed a significant change in spectra with the reductions of potassium oleate contents. Therefore, rubber foam formulations are still developed to provide the optimum properties for suitable applications.
Study of particle size of natural latex/polysaccharide composite
Authors: Wongphul K , Smitthipong W 
Published: March 2022

Abstract
The natural additive especially polysaccharide is interested in polymer composite field because it can be biocompatibility, biodegradability, non-toxic, low cost and easy to find. In addition, it should be used to reinforce the polymer matrix and to reduce the cost of material. This work focused on the comparison of particle size of natural latex with and without polysaccharide. Besides, the particle size of natural latex composite with polysaccharide was also investigated in various concentrations of polysaccharide. The natural latex with 5 wt.% of alginate represented the biggest particle size due to the agglomeration of rubber molecule with polysaccharide. The particle size of polymer latex is an important parameter to better understand the interaction between polymer and filler in the polymer composite.
Evaluation on physicochemical properties and stability of Thanaka bark powder for natural face powder products
Authors: Hnin N Y , Kanlayavattanakul M 
Published: March 2022

Abstract
Thanaka (Hesperethusa crenulata Roem.) has been traditionally applied as cosmetics in Myanmar and the northern of Thailand [1] and exhibited anti-oxidant, anti-inflammatory, anti-microbial, skin lightening, and sun protection properties [1-4]. Thanaka’s specifications for cosmetic development are sparse to be presented, although its flowability was reported [1]. Of which, the bark was more suitable than the stem for solid dosage form development [1]. Thus, this study was aimed to assess the physicochemical properties and stability of Thanaka bark powder. The yellowish light brown powder (L* = 75.63 ± 0.01, a* = 5.58 ± 0.02 and b* = 23.45 ± 0.02) (Figure 1A) with bulk and tapped densities of 0.25 ± 0.00 and 0.29 ± 0.00 g/mL, was able to absorb water and oil (17.31 ± 0.77% and 13.39 ± 0.29%). The powder was ICP-MS proved to be uncontaminated with heavy metals prohibited for cosmetics. The powder morphology was plate-like crystals with fractured as SEM observed (Figure 1B). Thermal properties examined by DSC resulted in glass transition, crystallization and melting temperatures of 66.43, 70.25 and 73.39°C, with 51.32 ± 4.13% of crystallinity by XRD. The color (ΔE ≤ 1.43 ± 0.04), morphology, thermal properties, water absorption capacity and oil absorption capacity slightly shifted following to 3-month storage under ambient temperature and 45°C.
Utilization of lignin extracted from Thai ago-waste as UV-blocking agent for BG-lignin/PLA composite films
Authors: Wijaranakul P , Hararak B , Winotapun C , Wannid P , Chotirotsukon C , Laosiripojana W 
Published: March 2022

Abstract
The improving properties of poly(lactic acid), PLA, by utilizing natural resources attracted great intrigue to make such a green composite material that can be used as a commercial product in human life [1]. Lignin is one of biopolymer that can be used as bio-based filler and multifunctional bio-additive in a polymer composite. The most exciting properties of lignin that can be provided in a polymer composite is UV absorption and anti-oxidation [2]. In this current study, organosolv lignin extracted from sugarcane bagasse (BG-lignin) was utilized as multifunctional bio-additive in PLA for improving the UV absorption. The physicochemical and thermal properties of BG-lignin were determined using several techniques including SEM, GPC, quantitative 31P NMR, and DSC. BG-lignin at different loading contents (0.1, 0.2, 0.5, and 1 wt.%) was mixed with PLA via melt-extrusion. The attained compounds were converted to composite films via blown film extrusion. With the 0.5 wt.% loading content, the PLA composite films (0.5BG-lignin/PLA) absorbed almost all UV radiation which exhibits almost 70% blocking of UVB. The onset oxidation temperature of the PLA/0.5BG composite film increased by 34% as compared to that of the neat PLA film. Adding of BG-lignin enhanced tensile strength and Young’s modulus but did not favour to elongation at break.
The validation HPLC method for determination of gambogic acid in gamboge resin
Authors: Khaing E M , Jitrangsri K , Mahadlek J , Sukonpan C , Phaechamud T 
Published: March 2022

Abstract
Gambogic acid obtained from plant resin of Garcinia species has anticancer properties. This study focuses on the development and validation of the high-performance liquid chromatography (HPLC) method for the quantification of gambogic acid (GA) content in the gamboge raw sample. The chromatographic system was performed on C18 column (150 × 4.6 mm, 5 μm). The system consisted of acetonitrile and 0.1% orthophosphoric acid (85:15 v/v) as mobile phase with a flow rate of 1.5 mL/min. The detection was carried out at a wavelength of 360 nm and the retention time of GA was evident at 9 min. The method was validated according to ICH guidelines. The obtained calibration plot exhibited good linearity in the range of 5 to 120 μg/mL (r2 > 0.999). The percentage recovery GA spiked in the gamboge sample ranged from 98.87% to 102.92%. The LOD and LOQ were shown to be 2.069 and 6.271 μg/mL, respectively. The validation study demonstrated that this method was simple, specific, and applicable for quantitative analysis of GA in gamboge resin.
Wood plastic composites (WPCs) from multilayer packaging wastes and rHDPE as pallets for green industry
Authors: Boonsri T , Rukchonlatee S , Jangchud I 
Published: March 2022

Abstract
People are becoming more aware of plastic pollution. Consumers, researchers, and manufacturers are seeking ways to reduce their contribution to the problem. Management of plastic wastes has still been severely environmental problems, especially those with multilayer or multicomponent structures due to the difficulty in recycling process. According to the concept of circular economy, this research aimed to overcome these problems by recycling the multilayer plastic film wastes after use from consumers (classified as post-consumer recycled resin, PCR) and transforming those into high-value products. In this work, Wood Plastic Composites (WPCs) made from mixtures of multilayer packaging wastes (PCRs), recycled high density polyethylene (rHDPE) and wood powders were studied in order to be used as pallets in green industry. Studied factors affecting WPC properties included PCR types (linear low density polyethylene (LLDPE), multilayered oriented polyamide (OPA)/PE and polyethylene terephthalate (PET)/PE films) and rHDPE:PCR weight ratios (40:5, 35:10, 30:15 and 25:20). WPC samples were compounded by a two-roll mill and then shaped into samples by a compression molding machine. Morphological, mechanical and thermal properties of WPCs were examined. From SEM study, it was revealed that wood powders and fibers were well distributed and randomly oriented in WPCs. Both PCRs (OPA/PE and PET/PE) were partially melted because the processing temperatures were below the crystalline melting temperatures of OPA and PET. PCR orientation in WPCs was aligned with the compression direction. Mechanical properties of WPCs from OPA/PE were similar to those of WPCs from PET/PE. WPCs from rHDPE:PCR weight ratios of 40:5 and 35:10 had good mechanical properties which passed the industrial target values. Optimum formulas were then used to form WPC samples by extrusion technique and fabricated into WPC pallets. It was found that the WPC pallets from wastes showed promising properties with high potential to replace conventional pallets in warehouses and industrial transport for green industry.
Properties of hydroxyapatite-based geopolymer synthesized from calcined kaolin
Authors: Poolkwan K , Asavapisit S , Piyapanuwat R 
Published: March 2022

Abstract
This research synthesized the geopolymer from calcined kaolin (600°C for 2 h in a muffle furnace) using sodium hydroxide (NaOH) and potassium hydroxide (KOH) as alkali activators. Calcium phosphate (CP) and heat treatment were introduced to study their effects on the unconfined compressive strength (USC) and crystalline phases formation of kaolin-based geopolymer. Results showed that the highest USC strength at 28 days of geopolymer was obtained from 0.4 moles of Na2O/SiO2 and K2O/SiO2 and gave strength of 12.95 and 11.56 MPa, respectively. The USC of geopolymer was observed to decrease with the addition of CP. The amounts of 5 wt.% of CP gave a 28-day strength of kaolin-based geopolymer containing NaOH and KOH activators at 9.95 and 8.88 MPa, respectively. The CP-doped geopolymers were then heated at temperatures of 500, 600, and 700°C for 2 h Results indicated that heat treatment at 600°C gave the highest USC of CP-doped geopolymer containing NaOH and KOH equal to 7.61 and 4.61 MPa, respectively with the appearance of hydroxyapatite, muscovite, and quartz in the XRD diffractograms.
Current generation from graphene vibrations
Authors: Charoenpakdee J , Mongkolsawat T , Suntijitrungruang O , Boonchui S 
Published: March 2022

Abstract
The application of electrical conductivity, extremely flexible graphene membranes, to capture energy from ambient vibrations has promising potential. We study the physics of self-energy from the vibrations and how current is created in graphene for theoretical research. We demonstrate the effects of lattice distortions on the electrical current, such as isotropic tensile strain ∈is, shear strain ∈ss, uniaxial armchair strain ∈as, and zigzag strain ∈zs. We show how this movement might cause an electrical current to flow in a neighbouring circuit.