bluuebunny/crossref_metadata_2025 huggingface dataset:
Laparoscopy-Assisted Transgastric ERCP: A Challenging Technique for Biliary Clearance Post Roux-en-Y Gastric Bypass
Authors: Garg Hitendra Kumar , Singh Pankaj , Peters Atul N. C. , Agarwal Shalabh , Gautam Yogesh , Mishra Dhruv Kant
Published: February 2022

Biliary complications after Roux-en-Y gastric bypass (RYGB) are not uncommon. Managing choledocholithiasis in this subset of patients is challenging as conventional endoscopic retrograde cholangiopancreatography (ERCP) is not possible due to lack of peroral access to the second part of duodenum. Enteroscopic approach, however, theoretically feasible is difficult and cumbersome, often resulting in failed procedure. Small series has reported higher success with a novel technique of laparoscopic transgastric access for ERCP. Laparoscopy-assisted ERCP (LA-ERCP) is now increasingly being recognized as a safe and reliable technique for biliary clearance with a low complication rate, making it a preferred approach for managing biliopancreatic disease in these groups of patients. Here we report a case of a young patient with gallstone disease and choledocholithiasis presenting with obstructive jaundice post RYGB who was successfully managed by LA-ERCP followed by laparoscopic cholecystectomy in the same session.
The Quality of Online Information on Cosmetic Injectable Fillers: Current Status
Authors: Shamil Eamon , North Alexander S. , Fan Ka Siu , D'Souza Hanna , Kaladjiska Maja , D'Souza Alwyn
Published: February 2022

Web-based health information plays an increasingly vital role in spreading health information. Many patients interested in aesthetic surgery study the procedure on the Internet. This study aims to evaluate the quality of online health information on injectable fillers using the modified “Ensuring Quality Information for Patients” (EQIP) tool. Nine different search terms, including “fillers,” “fuller cheeks,” “wrinkle removal,” and “antiwrinkle treatment” were identified and queried on Google. Unique links from the first three pages of each search term were identified and evaluated if the contents were in English language and were for general non-medical public use. A total of 172 websites were analyzed, with a median EQIP score of 20. In total 129 websites belonged to aesthetic practitioners, of which 81 were operated by medical doctors. Eighty-three percent of websites disclosed some forms of postoperative complications, most commonly edema (74%) and bruising (73%). Blindness and tissue necrosis were only mentioned by 12 and 10% of the websites, respectively. The current health information available on injectable fillers is of poor quality. While many do provide some information on risks, the majority of websites fail to disclose severe complications and quantifying risks. This poses a barrier against informed decision-making and may lead to unrealistic expectations. Patient satisfaction and expectations may be improved by developing better online education resources on fillers.
Rheologic and Physicochemical Characteristics of Hyaluronic Acid Fillers: Overview and Relationship to Product Performance
Authors: de la Guardia Carola , Virno Ada , Musumeci Maria , Bernardin Aude , Silberberg Michael B.
Published: February 2022

Injections with hyaluronic acid (HA) fillers for facial rejuvenation and soft-tissue augmentation are among the most popular aesthetic procedures worldwide. Many HA fillers are available with unique manufacturing processes and distinct in vitro physicochemical and rheologic properties, which result in important differences in the fillers' clinical performance. The aim of this paper is to provide an overview of the properties most widely used to characterize HA fillers and to report their rheologic and physicochemical values obtained using standardized methodology to allow scientifically based comparisons. Understanding rheologic and physicochemical properties will guide clinicians in aligning HA characteristics to the facial area being treated for optimal clinical performance.
Neuropsychiatric Treatments for Parkinson's Disease: Nonpharmacological Approaches
Authors: Mathur Neha , Bhatt Haseel , Lidstone Sarah C.
Published: February 2022

Although diagnosed by characteristic motor features, Parkinson's disease and other movement disorders are frequently accompanied by a wide range of neuropsychiatric symptoms that require a multidisciplinary approach for treatment. Neuropsychiatric symptoms such as depression, anxiety and cognitive symptoms strongly influence quality of life, motor symptoms, and non-motor bodily symptoms. This review summarizes our current understanding of the neuropsychiatric symptoms in movement disorders and discusses the evidence base for treatments focusing on rehabilitation and nonpharmacological approaches. A practical approach is then proposed for patient selection for specific treatments based on disease stage. The article focuses mostly on Parkinson's disease as a prototypical movement disorder with the largest evidence base but the principles discussed herein are applicable to a range of other movement disorders.
Under-represented, cautious, and modest: the gender gap at European Union Politics
Authors: Bettecken Julia , Klöckner Ann-Cathrin , Kurch Charlotte , Schneider Gerald
Published: February 2022

The gender gap pervades many core aspects of political science. This article reports that females continue to be under-represented as authors and reviewers in European Union Politics and that these differences have only diminished slightly since the second half of the 2000s. We also report that females use more cautious and modest language in their correspondence with the editorial office, but do not find evidence that this under-studied aspect of the gender gap affects the outcome of the reviewing process. The authors discuss some measures European Union Politics and other journals might take to address the imbalance.
Capillary suction predictions in granular materials subjected to 1D compression and triaxial loading with emphasis on projectile penetration
Authors: Thakur Mohmad Mohsin , Penumadu Dayakar
Published: February 2022

The role of partial saturation in penetration resistance of projectiles in granular materials is not clear due to experimental constraints imposed by high cost and special considerations in equipment design. In this work, granular material near the tip and far-field of the projectile is numerically simulated based on 1D compression and triaxial stress paths, respectively, using the finite discrete element method. The crushing of grains in 1D compression simulations is implemented by pre-inserting cohesive interface elements in regular finite element mesh. The capillary suction is numerically predicted by extracting the deformed granular assembly microstructure at different loading steps as an input to the pore morphology method. The results demonstrate the development of high capillary suction in 1D compression loading due to the significant crushing of grains. The evolution of capillary suction is negligible during triaxial loading compared to the 1D compression loading. This suggests that future simulations related to projectile penetration in partially saturated granular materials should account for coupled hydromechanical effects near the tip whereas the far-field can be approximated as a dry material. Finally, the capillary suction corresponding to extreme comminution near the projectile tip is estimated from a 3D assembly of spherical grains with a mean grain size of 1 µm.
Layered phase composition and microstructure of κ-Ga2O3-dominant heteroepitaxial films grown via MOCVD
Authors: Jiang Kunyao , Tang Jingyu , Cabral Matthew J. , Park Anna , Gu Liuxin , Davis Robert F. , Porter Lisa M.
Published: February 2022

Phase and microstructural evolution of gallium oxide (Ga2O3) films grown on vicinal (0001) sapphire substrates was investigated using a suite of analytical tools. High-resolution transmission electron microscopy and scanning transmission electron microscopy of a film grown at 530 °C revealed the initial pseudomorphic growth of three to four monolayers of α-Ga2O3, a 20–60 nm transition layer that contained both β- and γ-Ga2O3, and a top ∼700 nm-thick layer of phase-pure κ-Ga2O3. Explanations for the occurrence of these phases and their sequence of formation are presented. Additional growths of Ga2O3 films in tandem with x-ray diffraction and scanning electron microscopy investigations revealed that the top layer varied in phase composition between ∼100% κ-Ga2O3 and ∼100% β-Ga2O3; the surface microstructure ranged from poorly coalesced to completely coalesced grains as a function of growth temperature, growth rate, or diluent gas flow rate. In general, it was found that the κ-phase is favored at lower growth temperatures and higher triethylgallium flow rates (low VI/III ratios). The growth of nominally single-phase κ-Ga2O3 within the top layer was observed in a temperature range between 500 and 530 °C. Below 470 °C, only amorphous Ga2O3 was obtained; above 570 °C, only the β-phase was deposited.
Self-sputtering of the Lennard–Jones crystal
Authors: Mauchamp Nicolas A. , Ikuse Kazumasa , Isobe Michiro , Hamaguchi Satoshi
Published: February 2022

The self-sputtering yield of the (100) face-centered cubic crystal surface consisting of particles interacting with the Lennard–Jones (LJ) potential is presented as a function of the normalized incident particle kinetic energy for normal incidence. Because the self-sputtering yield depends only on the normalized incident energy, the yield curve presented here is the universal curve, independent of the Lennard–Jones parameters, and therefore serves as the fundamental reference data for the LJ system. The self-sputtering yield data are also compared with experimentally obtained self-sputtering yields of some metals, which shows reasonable agreement at relatively low ion incident energy where mostly deposition occurs. At higher ion energy, the self-sputtering of such an LJ material does not represent those of real solids. This is because the repulsive interactions of the LJ potential do not represent those of actual atoms at short distances. The angle dependence of the self-sputtering yield is also presented for some selected normalized energies.
In situ de-wetting of liquid–solid interface to fabricate spherical Ag@Ni immiscible alloys
Authors: Zhou Cheng , Lei Chenglong , Qian Jin , Ge Chuannan , Tang Shaolong , Du Youwei
Published: February 2022

Spherical Ag@Ni immiscible alloy powders were successfully fabricated combining in situ de-wetting of metal droplets from a metalloid solid medium with phase separation of immiscible alloys. The effects of atom ratio and temperature on morphology, structure, and phase separation were investigated. The spherical morphology of alloy powders confirmed the de-wetting of the liquid–solid interface between the liquid Ni–Ag immiscible alloy and the solid alumina powder medium. The Ni-rich phase was scattered in the Ag-rich phase matrix at 1673 K while the spherical Ni-core at the center was surrounded by a ring-shaped shell of Ag at the outer layer with an egg-type structure at 1753 K. The egg-type microstructure of the Ni–Ag particle resulted from the liquid–liquid immiscible phase separation. Such spherical Ag@Ni alloy powders with an egg-type microstructure have a good combination of a high strength Ni-rich phase core and a high electric and thermal conductivity Ag-rich phase shell with many potential advanced applications in electronic packaging.
Vibrational treatment of hydroxylamine in valence coordinates
Authors: Richter Falk , Carbonnière P.
Published: February 2022

A valence coordinate H2NOH ground state potential energy surface accurate for all levels up to 6000 cm−1 relative to trans zero point energy has been generated at the coupled-cluster single double triple-F12/aug-cc-pVTZ level encompassing the trans and cis as well as the N–H2 permutational conformers. All cis and trans fundamentals and a complete set of eigenfunctions up to about 3100 cm−1 have been calculated and assigned using the improved relaxation method of the Heidelberg multi-configuration time-dependent Hartree package and an exact expression for the kinetic energy in valence coordinates generated by the TANA program. The average and maximal error to all observed transitions is about 6.3 and 14.6 cm−1, respectively. Local cis eigenfunctions exist with up to two quanta in the isomerization mode ν9. Although no significant inversion splittings have been found up to the considered 3100 cm−1, they are expected within the fundamental energy range in view of the calculated 4261 cm−1 H2 permutation/inversion barrier height. The cis-NH2 symmetric stretch fundamental shows a Fermi resonance with a splitting of about 10 cm−1.
Radio-tracking wildlife with drones: a viewshed analysis quantifying survey coverage across diverse landscapes
Authors: Saunders Debbie , Nguyen Huyen , Cowen Saul , Magrath Michael , Marsh Karen , Bell Sarah , Bobruk Josh
Published: February 2022

Radio-tracking tagged wildlife remains a critical research technique for understanding the movements, behaviours and survival of many species. However, traditional hand-held tracking techniques on the ground are labour intensive and time consuming. Therefore, researchers are increasingly seeking new technologies to address these challenges, including drone radio-tracking receivers. Following the implementation of drone radio-tracking techniques for five different threatened species projects within different habitat and landscape types, we identified the need to quantify the relative spatial extent of surveys using both drone and hand-held techniques for each project. This was undertaken using viewshed analyses. These analyses demonstrated that survey coverage with drone-based radio-tracking was substantially greater than that of hand-held radio-tracking for all species and landscapes examined. Within mountainous landscapes, drone radio-tracking covered up to four times the area of hand-held tracking, whereas in flat to undulating landscapes, drone surveys covered up to 11.3 times the area that could be surveyed using hand-held techniques from the same locations on the ground. The viewshed analyses were also found to be a valuable visualisation tool for identifying areas for targeted surveys to reduce the risk of ‘losing’ tagged animals, which has traditionally been one of the biggest radio-tracking challenges.
The Social Practice of Care Hotel Vacations
Authors: Bargeman Bertine , Richards Greg , Charante-Stoffelen Marleen
Published: February 2022

Due to the increase in the number of elderly and people seeking medical care, the hotel market with a blend of care and leisure experiences is expected to grow in the future (
Han, 2013
;
Karuppan & Karuppan, 2010
;
Laesser, 2011
). The role of care hotels as an intersection between the care and the tourism sectors makes a vacation in a care hotel an interesting social practice to study. In this contribution a social practices approach (
Spaargaren, 1997
) is applied to investigate how demand and supply interact during a care hotel vacation. Semi-structured interviews are used to identify successful and less successful interactions or practices between senior guests and personnel in five Dutch care hotels. These interactions are related to materials (care and leisure facilities), competences (skills and empathy of the personnel) and meanings (motivations and aspirations of guests) in the care hotel practice (see
Shove et al., 2012
). The results show that a social practice approach combined with a qualitative research method may be more suited to analysing the complex encounters between guests and personnel during care hotel vacations than more traditional theories from service or experience quality studies. Simultaneously, this study makes clear that we need to develop alternative qualitative (and/or quantitative) research methods to study more privacy-related or intimate practices or rituals as in the case of care hotels.

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© Bertine Bargeman, Greg Richards and Marleen van Charante-Stoffelen 2018
Homology conditions for RT surfaces in double holography
Authors: Neuenfeld Dominik
Published: February 2022

Recently, a novel formula for computing entropy in theories coupled to semi-classical gravity has been devised. Using this so-called island formula the entropy of semi-classical black holes follows a Page curve. Here, we study the relation between this novel entropy and semi-classical entropy in the context of doubly-holographic models. Double holography allows for two different d-dimensional descriptions of a black hole coupled to a non-gravitational bath, both of which allow a holographic computation of von Neumann entropy in bath subregions. We argue that the correct homology constraint for Ryu–Takayanagi surfaces depends on which of those d-dimensional perspectives is taken. As a consequence the von Neumann entropies of a fixed subregion in both descriptions can disagree. We discuss how the von Neumann entropies in both descriptions are related to the entropy computed by the island formula and coarse grained entropy. Moreover, we argue that the way operators transform between the two descriptions depends on their complexity. A simple toy model is introduced to demonstrate that a sufficiently complicated map between two descriptions of the system can give rise to an island formula and wormholes. Lastly, we speculate about the relation between double-holography and black hole complementarity.
The representation of women in Irish Leaving Certificate Physics textbooks
Authors: Pillion Karen , Bergin Shane D
Published: February 2022

This paper examines the representation of women in Irish Leaving Certificate Physics textbooks. Findings show that women are significantly underrepresented, both in terms of scientific characters (historic and current) described within the textbooks, and also in terms of more general non-scientific characters within the books. Furthermore, analysis suggests that the language used to describe characters mentioned in the books may compound gender inequalities. Relevant policies (curricular, governmental, etc) are examined and suggestions are made to improve gender balance in future textbooks.
Simple physics behind the flight of a drone
Authors: Monteiro Martín , Stari Cecilia , Cabeza Cecilia , Martí Arturo C
Published: February 2022

The flight of a quadcopter drone, readily available as a toy, is analyzed using simple physics concepts. A smartphone with built-in accelerometer and gyroscope was attached to the drone to register the accelerations and angular velocities along the three spatial axis while the drone is taking off, landing or rotating. The vertical speed, the height and one of the angular coordinates are obtained through numerical integration of the acceleration values and compared with information provided by the manufacturer. The analysis of these quantities provides an opportunity to gain insight into important physics concepts involving Newton laws and conservation principles in a stimulating environment.
A portable fan-based device for evaluating lung function in horses by the forced oscillation technique
Authors: Bizzotto Davide , Paganini Stefano , Stucchi Luca , Avallone Matteo Palmisano , Ramirez Esther Millares , Pompilio Pasquale P , Ferrucci Francesco , Lavoie Jean-Pierre , Dellacà Raffaele L
Published: February 2022

Objective. The assessment of lung mechanics in horses is nowadays based on invasive methods that may require sedation. The forced oscillation technique (FOT) allows the non-invasive assessment of respiratory mechanics during spontaneous breathing, but current devices are complex, cumbersome, expensive, and difficult to be applied in horses.Approach. We developed a portable FOT device based on a novel approach in which the pressure waveforms are generated by a servo-controlled ducted fan. This new approach allows the design of devices that are more sturdy, compact, and portable compared to already existing approaches. The prototype includes 1) a small microcontroller-based electronic board for controlling the fan and measuring flow and pressure and 2) an optimized data processing algorithm.Main results. This device provides a maximum error of 0.06 cmH2O·s/L and 0.15 cmH2O·s/L in measuring respiratory resistance and reactance duringin-vitrovalidation. A pilot study was also performed on three healthy horses and three horses with severe equine asthma (SEA) and it demonstrated good tolerability and feasibility of the new device. Total respiratory system resistance (Rrs) and reactance (Xrs) significantly differed (p< 0.05) between groups. At 5 Hz,Rrswas 0.66 ± 0.02 cmH2O·s/L and 0.94 ± 0.07 cmH2O·s/L in healthy and in SEA, respectively.Xrs0.38 ± 0.02 cmH2O·s/L and −0.27 ± 0.05 cmH2O·s/L.Significance. This novel approach for applying FOT allowed the development of a small, affordable, and portable device for the non-invasive evaluation of respiratory mechanics in spontaneously breathing horses, providing a useful new tool for improving veterinary respiratory medicine. Moreover, our results provide supporting evidence of the value of this novel approach for developing portable FOT devices also for applications in humans.
Vortex shaking study with use of linear voltage–current law
Authors: Fazilleau Philippe , Dilasser Guillaume
Published: February 2022

Experiments show that the application of an AC magnetic field parallel to a thin superconductor tape can reduce the magnetization caused by screening currents. A theory has been developed by Sakamoto and Brandt stating that a DC electric field is generated during the application of the AC magnetic field and leads to the decay of the screening currents through the homogenization of the current density within the tape. The DC electrical field has the same direction as the current lines and is linear with the current density magnitude. First, we perform numerical simulations via a finite difference method in MATLAB to compute the effects of such a DC electrical field and its linear law and compare it with the widely used power law on two different cases an infinitely long thin tape and a single tape solenoid. We then study the effects of vortex-shaking computed with both laws on a coil made of several turns.
Water ice-cooled MgB2 coil made by wind and react process
Authors: Kováč P , Kopera L , Melišek T , Búran M , Hušek I , Berek D , Kováč J
Published: February 2022

A wind and react (W&R) coil of inner diameter 53 mm has been made from multi-core MgB2/Nb/CuNi wire manufactured by the internal magnesium diffusion (IMD) process. The W&R coil is wound from non-insulated rectangular wire of 1 mm2 with only 5 µm thick stainless steel foil used for interlayer insulation. The transport current performance of the coil and short wire samples was measured in a liquid He bath at external magnetic fields of 4.5–8.5 T and also in self-field conditions in sub-cooled water ice at temperatures between 33 K and 38 K. The presented MgB2 coil exhibits stable behavior at water ice cooling, and its high space factor allows a high current density of winding in comparison to the data from the already published MgB2 coils. The presented results demonstrate that MgB2 windings can be used safely in He-free conditions inside sub-cooled water ice, and this technique can be further optimized and used for future MgB2 coils.
Photon BEC with thermo-optic interaction at dimensional crossover
Authors: Stein Enrico , Pelster Axel
Published: February 2022

Since the advent of experiments with photon Bose–Einstein condensates (phBECs) in dye-filled microcavities in 2010, many investigations have focussed upon the emerging effective photon–photon interaction. Despite its smallness, it can be identified to stem from two physically distinct mechanisms. On the one hand, a Kerr nonlinearity of the dye medium yields a photon–photon contact interaction. On the other hand, a heating of the dye medium leads to an additional thermo-optic interaction, which is both delayed and non-local. The latter turns out to represent the leading contribution to the effective interaction for the current 2D experiments. Here we analyse theoretically how the effective photon–photon interaction increases when the system dimension is reduced from 2D to 1D. To this end, we consider an anisotropic harmonic trapping potential and determine via a variational approach how the properties of the phBEC in general, and both aforementioned interaction mechanisms in particular, change with increasing anisotropy. We find that the thermo-optic interaction strength increases at first linearly with the trap aspect ratio and later on saturates at a certain value of the trap aspect ratio. Furthermore, in the strong 1D limit the roles of both interactions get reversed as the thermo-optic interaction remains saturated and the contact Kerr interaction becomes the leading interaction mechanism. Finally, we discuss how the predicted effects can be measured experimentally.
Search for cosmological time dilation from gamma-ray bursts — a 2021 status update
Authors: Singh Amitesh , Desai Shantanu
Published: February 2022

We carry out a search for signatures of cosmological time dilation in the light curves of Gamma Ray Bursts (GRBs), detected by the Neil Gehrels Swift Observatory. For this purpose, we calculate two different durations (T
50 and T
90) for a sample of 247 GRBs in the fixed rest frame energy interval of 140–350 keV, similar to a previous work [1]. We then carry out a power law-based regression analysis between the durations and redshifts. This search is done using both the unbinned as well as the binned data, where both the weighted mean and the geometric mean was used.
For each analysis, we also calculate the intrinsic scatter to determine the tightness of the relation. We find that the weighted mean-based binned data for long GRBs and the geometric mean-based binned data is consistent with the cosmological time dilation signature, whereas the analyses using unbinned durations show a very large scatter. We also make our analysis codes and the procedure for obtaining the light curves and estimation of T
50/T
90 publicly available.
Characterizing spatio-temporal aspects of chirped pulse amplification laser micro-cone target interaction
Authors: Ionel Laura
Published: February 2022

A numerical study of spatio-temporal distortions effect on the output chirped pulse amplification (CPA) laser beam at the interaction with a micro-cone target was developed. For this, several laser configurations based on CPA technique have been designed and complex study for spatio-temporal distortions compensation has been elaborated using a raytracing model from Optica module of Mathematica in order to determine the optimum conditions to streamline the laser field intensification in the vicinity of laser–conical target interaction point. This numerical model offers an effective solution to fine tune the output CPA beam pulse duration or to control or mitigate the current beam pointing fluctuations caused by specific internal processes during experiments in high-power regimes.
Bio-based resin/cellulose composites for UV-assisted 3D printed orthopedic casts
Authors: Sakunphokesup Kittinon , Aumnate Chuanchom , Potiyaraj Pranut
Published: February 2022

An orthopedic cast is a device used for stabilizing bone fracture. To date, the conventional plaster casts do not have reasonable control over the functional characteristics of comfort, lightweight, and return in patients’ everyday life during the healing process. Three-dimensional (3D) printing is a rapidly growing and impressive technology with plentiful possibilities for customized rehabilitation tools, particularly the orthopedic cast. However, the 3D-printing materials are still limited, especially in terms of their printability and mechanical strength. In this work, bio-based resin/cellulose composites are developed as alternative materials to enhance mechanical performance for DLP (Digital Light Processing) 3D printing, which could further potentially fabricate 3D-printed cast. Triacetin, polypropylene glycol (PPG) and PEGDA are used to improve the distribution and dispersion of cellulose in bio-based resin. The results indicated that the mechanical properties improved with appropriate printed direction. The 90° printing direction gave the higher flexural strength than that of the 46.62° printing direction, which are 2650 MPa and 2487 MPa, respectively. Also, more printing accuracy was found for the 90° printing direction. SEM images revealed well dispersion of cellulose in bio-based PLA resin composite with PEGDA. However, the interfacial adhesion needs to be further improved to enhance the mechanical performance.
Optimization of Printing Parameters for Printing of Ordinary Portland Cement using a Custom-made 3D Printer
Authors: Chaiyotha D , Pinitsoontorn S , Chindaprasirt P , Payakaniti P
Published: February 2022

3D printing techniques have recently received a lot of attention as a new technique for forming construction materials, due to benefits over the traditional cast. In this research, ordinary Portland cement (OPC) paste was formed using a 3D extruder. Optimized mixture and printing parameters were determined. Compressive strengths of the printed and the traditionally casted OPC paste were measured after the specimens were cured in saturated limewater for 7, 14 and 28 days, respectively. The result led to the conclusion that the most suitable mixture for printing was achieved at the water to cement ratio of 0.35 with water reducing and retarding admixture added. The optimum printing parameters were the printing speed of 60 mm/min and the feed rate of 120 ml/s. Compressive strength of the 5 x 5 x 5 cm3 hollowed and filled cubic printed specimens, were compared with casted cement paste. The strengths of both the printed and the casted specimens were higher with longer curing durations. The highest levels of strength were achieved at 12.36 MPa on the printed specimens and 80.88 MPa when testing the casted samples.
Effect of adding carboxymethyl cellulose, zeolite and microcrystalline cellulose on the optical and mechanical properties of latex composite films
Authors: Chindawong Chakkresit , Setthaya Naruemon , Mekrattanachai Pagasukon , Damrongwiriyanupap Nattapong , Pimraksa Kedsarin , Johannsmann Diethelm
Published: February 2022

In this research, four-types of latex composite films which are carboxymethyl cellulose latex composite film, zeolite latex composite film, microcrystalline cellulose latex composite film and microcrystalline cellulose sodium hydroxide latex composite film were prepared by casting method. Drying time of all films formation is 24 hr. The average thickness of the dry film is 0.10 mm. The transparency of films were measured by UV-Vis spectrophotometer. It was found that the carboxymethyl cellulose latex composite film have more transparency than zeolite latex composite film, microcrystalline cellulose latex composite film and microcrystalline cellulose sodium hydroxide latex composite film respectively. The analysis of functional group of films were measured by ATR-FTIR technique. It was found that all types of films consist of O-H stretching group and C=O group without ether group of cellulose and Si-O-Al group of zeolite. The mechanical property of films were measured by Universal Testing Machine. It was found that the Young’s modulus of microcrystalline cellulose sodium hydroxide latex composite film was higher than microcrystalline cellulose latex composite film, zeolite latex composite film and carboxymethyl cellulose latex composite film respectively. The characteristic of stress-strain curve of films showed that all films were hard and brittle except microcrystalline cellulose latex composite films were hard and tough.
Effect of essential oil on properties of PBAT/PBS for bio-packaging films
Authors: Threepopnatkul Poonsub , Charoendee Nattakit , Wiriyamontree Nattanan , Phodaeng Anuwat
Published: February 2022

This research aimed to study the effect of essential oil on the mechanical and barrier properties of bio-packaging films from a polymer blend between polybutylene adipate-co-terephthalate and polybutylene succinate (PBAT/PBS) using the β-cyclodextrin (βCD) as controlled release for sweet basil essential oil (ES). PBAT grafted with maleic anhydride (PBAT-g-MA) is used as compatibilizer between polymer matrix and β-cyclodextrin. The MA grating content is found to be 2.47% w/w. The preparation of PBAT/PBS blend films with two weight ratios includes 80/20 and 60/40 with varied βCD-ES contents of 0, 0.25, 0.50, 0.75 and 1.00 phr. Tensile strength and elongation at break were increased when β-cyclodextrin with essestial oil decreasing. Considering the ratio of PBAT/PBS, the mechanical properties i.e., tensile strength, Young’ s modulus and elongation at break of PBAT/PBS film at weight ratio of 80/20 incorporated with βCD-ES were higher than the ones at weight ratio of 60/40. For barrier properties, water vapor and oxygen permeability of PBAT/PBS films incorporated with lower essential oils content would be decreased. For antimicrobial test, PBAT/PBS with βCD-ES film packaging could effectively inhibit the mold growth on tomatoes after 40 days.
Cadmium(II) and copper(II) complexes containing benzoate derivatives and 2-aminopyrimidine ligands: Synthesis, crystal structures and antibacterial activity
Authors: Thummatudtho Sudarat , Phadungsak Natthakorn , Chainok Kittipong , Kandiah Mathi , Zheng Alvin Lim Teik , Andou Yoshito , Boonyuen Supakorn
Published: February 2022

The new Cd(II) and Cu(II) complexes namely [Cd2(2-OHbza)4(apm)4] (1), [Cu2(2-OHbza)4(apm)]n•2(2-OHbza) (2) and [Cu2(2-CH3bza)4(apm)]n (3) (2-OHbza = 2-hydroxybenzoate, 2-CH3bza = 2-methylbenzoate and apm = 2-aminopyrimidine) were successfully prepared by using direct one pot synthesis method. All complexes were characterized by using CHN elemental analysis, FT-IR spectroscopy, powder X-ray diffraction and single crystal X-ray diffraction techniques. Compound 1 crystallized in monoclinic space group P21/c, while compound 2 and 3 crystallized in triclinic space group P-1. The dinuclear compound 1 consists of two seven-coordinated Cd(II) centers which are doubly bridged by 2-OHbza bridging ligands, while the rest two 2-OHbza and two apm are terminal ligand. The crystal structure of compound 1 is stabilized by the intermolecular hydrogen bonding and C-H•••π interaction and π•••π interactions. Compounds 2 and 3 present zigzag one-dimensional chainlike-structure which dimer Cu(II) units are linked by apm ligand. The crystal structure of these compounds is stabilized by π•••π and C-H•••π interactions. The photoluminescence properties of compound 1 has been studied comparing to those of 2-OHbza and apm ligands. The solid state PL emission spectrum of compound 1 shows similar intensity of free apm ligand and shape to free 2-OHbza ligand which present a single broad band centered at λem 525 nm (λex = 325 nm), but blue-shift. For solution PL experiment of compound 1 in various solvents, the results showed that compound 1 is selective PL quenching acetone. Electronic spectra for solid state and solution in different solvents of compounds 2 and 3 present the d-d absorption bands centered in the range of 701 – 794 nm. The highest red shifts of λmax are found for compounds 2 and 3 in DMSO. In addition, the antibacterial activity of all compounds are investigated for S.aureus and E.coil by agar diffusion method. The results show that compound 1 exhibits the activity against S.aureus better than E.coil.
Biodiesel production from used palm oil using magnetic solid base catalyst
Authors: Singhanatkaisi Natthakit , Kandiah Mathi , Zheng Alvin Lim Teik , Ando Yoshito , Boonyuen Supakorn
Published: February 2022

In this research the biodiesel from palm oil were synthesized by using magnetic solid base catalyst. The magnetic solid base catalyst was prepared by using co-precipitation method and followed by modified Stober’s method and wet impregnation method. CaO-ferrite nanometre magnetic solid base catalysts (CaO@Fe3O4/SiO2) were synthesized by loading CaO on the surface of Fe3O4 core-shell using the polymeric binder, TEOS. Under the optimized condition reactions, the catalysts were synthesized by co-precipitation and incipient wetness impregnation followed by calcination at 700 °C for 5 h. The calcined catalyst was fully characterized. The basic strength of the catalysts (H_) was first assessed using Hammett indicators, which are in range 9.8–15.0. The calcined Ca/ferrite-TEOS showed homogenous spherical shape with an apparent thickness of 92 nm. The FT-IR of CaO observed at 520 cm-1 is attributed to the Ca-O vibrations. The EDX analysis confirmed the presence of Fe, Si and Ca on the catalyst. The optimization conditions for biodiesel production have been measured. The catalyst was used 5.0 % wt. The methanol to oil ratio is 5:1, reaction time is 180 minutes and reaction was produced at 80°C. The catalyst achieved a biodiesel conversion of used palm oil (acid value 1.2) above 92 %. The catalytic activity and recovery rate of CaO@Fe3O4/SiO2 are better as compared to CaO catalyst. The properties of synthesized biodiesel have been studied and meet standard the Department of Energy Business.
Estimation of ethylene/1-butene copolymerization conditions using the autoencoder model
Authors: Amnuaykijvanit O , Anantawaraskul S , Rakthanmanon T
Published: February 2022

Chain microstructures of ethylene/1-butene copolymers produced at specific polymerization conditions can be calculated using the copolymerization kinetic model. However, this kinetic model cannot be solved inversely to estimate polymerization conditions from desired microstructures. In this work, the autoencoder (AE) model, the machine learning techniques based on artificial neural network (ANN) concept, was developed to help estimate polymerization conditions to produce polymers with desired microstructures (e.g., molecular weight distribution (MWD), chemical composition distribution (CCD), and number and weight average molecular weight). Two models were developed in this work: one with only microstructural distributions (MWD and CCD) and the other with additional information on average microstructures and polymer yield. The results showed that the proposed AE models can adequately estimate polymerization conditions from desired microstructures with acceptable mean square error (MSE). More specific microstructures lead to better estimation of polymerization conditions with lower MSE.
Evaluation of alginate-cellulose used in controlled release fertilizer for slow nutrient release and water retention
Authors: Kamolsiriwat N. , Pianpanit T. , Pongkitiwanichakul P. , Boonchui S.
Published: February 2022

Alginate-cellulose is a green material with water retention properties. This research proposed the simulation model of controlled-release fertilizer by using the material with similar properties to Alginate-cellulose. We use the simulation model to investigate polymer-blended fertilizer performance compared to polymer-coated fertilizer and study the controlling factor of controlled releases, such as the shape of fertilizer and roughness of polymer coating. Our simulation result concludes that the fertilizer shape with a higher perimeter to the area for the unit area and roughness on imperfection coating causes the faster nutrient release. Moreover, we discover that polymer-blended fertilizer is acceptable for the alternative method of controlled-release fertilizer and can perform better with increased polymer proportion, especially when the polymer proportion is more than 30 %.
Influence of SFT Content on Physical, Mechanical and Dielectric Properties of BNKT-SFT Binary Ceramic System
Authors: Inthong S , Kruea-In C
Published: February 2022

In this research, the binary solid solution Bi0.5(Na0.84K0.16)0.5TiO3 and Sr(Fe0.5Ta0.5)O3 in the system of (1-x)BNKT-xSFT was synthesized by solid-state reaction technique. The mixed powder and ceramics of (1-x)BNKT-xSFT where x=0.00, 0.01, 0.02, 0.03 and 0.04 were calcined at 900 °C for 2 h and sintered at 1125 °C for 2 h. The sintered ceramic samples were investigated phase formation, densification, mechanical properties, and dielectric constant at room temperature. The XRD analysis of all condition samples shows a pure phase perovskite structure. The maximum of bulk density, HV, HK microhardness, the elastic modulus, fracture toughness, and dielectric constant were found at x= 0.04 condition which the value is 5.877 g/cm3, 6.21 GPa, 5.39 GPa, 181.12 GPa, 0.19 MPa·m1/2 and 1,404, respectively. A small among SFT content shows an improvement of densification, mechanical properties, and dielectric constant in (1-x)BNKT-xSFT ceramics. The relations of these results were discussed and compared to the previously reported.
Fabrication of Natural Rubber Latex Foam Composite Filled with Pineapple-leaf Cellulose Fibres
Authors: Pinrat S , Dittanet P , Seubsai A , Prapainainar P
Published: February 2022

Pineapple leaf (PL) is a renewable agriculture residue which are abundance in Thailand. In this paper, cellulose powder was extracted from PL. Celluloses are typically used as fillers for rubber reinforced composites due to their properties such as high mechanical properties, low cost, low density, and biodegradability. The aim of this study was to optimize the method to prepare natural rubber latex foam (NRLF) with different cellulose loadings from 0 to 7 phr by using Dunlop method. The different steps for adding celluloses in this study were adding in pre-vulcanization process and in foaming process were studied. The tensile properties, density, compression, and microstructural characterization were studied. Morphological and microstructural performed by using scanning electron microscopy (SEM). It was found that adding cellulose in pre-vulcanization step showed well distribution of cellulose while adding cellulose in foaming process showed the settle of cellulose at the bottom of the foam sample. The tensile strength and elongation at break decreased with increasing of cellulose content whereas modulus increased with increasing of cellulose content.
Preparation of cellulose nanofibers from cassava pulp residue by mechanical defibrillation
Authors: Suksri C , Aht-Ong D
Published: February 2022

Cassava pulp residue (CPR) is one of the most interesting renewable materials that is widely used as active precursors for many applications. Based on its characteristic, cellulose is a typical component locally found in CPR in which it plays an important role in various potential fileds such as reinforcing fillers, stabilizing agents, and dietary fibers. To prepare cellulose nanofibers (CNFs), mechanical defibrillation by microfluidizer is an effective method commonly employed to reduce the size of cellulose from micro-to nanoscale. In this work, CNFs were successfully prepared from CPR by alkaline treatment, hydrogen peroxide bleaching, and mechanical defibrillation at different times. Physical, thermal, and morphological properties of the resulting fibers were comparatively demonstrated. The results showed that most of the impurities in CPR including residual starch granules, lignin, and hemicellulose were removed significantly after chemical treatments. Additionally, thermal degradation temperatures of the obtained fibers were improved remarkably, while the degree of crystallinity with cellulose type I structure was also increased when comparing to CPR. As observed by FE-SEM analysis, the CNFs revealed a fibrous network structure having a mean diameter in the range of 10-30 nm. The produced CNFs could be utilized as reinforcing fillers, food packaging, and biomedical fields.
Quenches and confinement in a Heisenberg–Ising spin ladder
Authors: Lagnese Gianluca , Surace Federica Maria , Kormos Márton , Calabrese Pasquale
Published: February 2022

We consider the quantum quench dynamics of a Heisenberg–Ising spin ladder which is an archetypal model in which confinement of elementary excitations is triggered by internal interactions rather than an external field. We show that the confinement strongly affects the light cone structure of correlation functions providing signatures of the velocities of the mesons of the model. We also show that the meson masses can be measured from the real time analysis of the evolution of the order parameter.
Synchronization Model of Sea Transport Scheduling of Pioneer Ship and Sea Toll: Case Study at Maluku
Authors: Devintasari Dika Virginia , Yunianto Irwan Tri , Ardhi Eka Wahyu , Rahman Ilham Muliana
Published: February 2022

Sea transportation is the only vessels connected to islands in Indonesia, especially Pioneer Shipping that has an important role to connect the smaller and isolated islands to reduce price disparity. Pioneer shipping becomes a Feeder Vessel from Sea Toll and Pelni Passenger Ship that must be maintained reliability of scheduling accuracy in accordance with ministerial regulation number 37 of 2015. The aim of this research is to create a model of synchronization ship scheduling that considers to the arrival of the main ship (sea toll and pelni passenger ship) with feeder vessel (pioneer shipping) that can determine the impact financially for users (passengers and shipper) and ship operators. Agent-based simulation methods are used in this research to obtain scheduled arrivals and departures of ships using AnyLogic Software 8.7.4 (Personal Learning Edition). Therefore, schedule is considering the synchronization between the departure and arrival of the main ship (sea toll transportation and passenger transport) with the feeder (pioneering transport) ship.
Experimental Evaluation of Structural Hull Damping Coefficient of a Hydro-Elastic Segmented Submarine Model
Authors: Nugroho W H , Purnomo NJH , Priohutomo RK , Suwarni E
Published: February 2022

This paper presents an experimental study of determining structural damping ratio of the hydro-elastic submarine model. The model test of a hydro-elastic submarine model was conducted at the Towing Tank facility of the Indonesian Hydrodynamic Laboratory (BTH-BPPT). To investigate the effect of the wet and dry damping ratio the vibration tests were performed in both air and water. The experiments in wet and dry condition were undertaken to investigate the influences of the damping ratio at zero forward speed. Vibration tests were also conducted in the Towing Tank at speed in calm water to explore the effect of the forward speed on both fixed and free pitch conditions on the damping ratio. From these experiments it has been found the damping ratios of wet condition are greater than the dry one. The damping ratios increased also as the submarine model speeds forward, whereas both the fixed and free pitch showed an increase in the damping ratio with increase forward speed.
Analysis of Wrist Hand Motion for Monitoring of Basic Welder Training using Wearable Sensors
Authors: Pribadi T W , Shinoda T
Published: February 2022

During the training of a welder, either novice or professional, most activities are focused on the acquisition of wrist-hand motion skills. In the basic welding training, trainees initially required hand-on practices to acquire the skills of wrist hand motion to maintain the distance of electrode tip to a base metal such that the welding arc was continuously flaming. Secondly, trainees were practices of manipulating hand motion to follow seam tracking for joining two metals within defined speed & torch height. These practices were then continued for various types of weld joints. The result of acquiring this skill level was then assessed by inspecting the visual appearance of the weldment. In this study, an effort was undertaken to monitor and assess the progress of acquiring wrist-hand motion skills using wearable sensors: accelerometer, gyroscope, and magnetometer. Then, the record of those sensors was plotted as a time series signal compared with those performed by the training instructor. Their achievement of skills grade was analyzed using the Supervised Vector Machine (SVM) Learning Method. The result has indicated that this proposed method can assist in assessing welder trainees’ efforts to improve their skills.