bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Type of Metals on Site Selective Dehydrogenation of Stearic Acid
Authors: Karasuta Chayakorn , Sirimittagoon Supakorn , Chantanuson Ratchanon , Pavarajarn Varong
Published: January 2021

Short-chain fatty acids (SCFAs) have been used as raw materials in wide range of chemical and medical applications. One technique to produce SCFAs is oxidative cleavage of long-chain fatty acids (LCFAs). However, unless the LCFAs are unsaturated, the yield of SCFAs is often very low because the carboxylic group of the fatty acid is more active than other part of the molecule. This work explores the idea of introducing a double bond into saturated LCFA, i.e., stearic acid, via selective dehydrogenation using commercial heterogeneous catalysts. However, cracking of the LCFA is also catalysed. Different type of metals was therefore investigated to study the effect of metals on the cracking and dehydrogenation. The experiments were conducted in an autoclave reactor under inert atmosphere. The temperature was in the range of 250–350°C. The products were analysed by gas chromatography equipped with mass spectroscopy (GC/MS). The results reveal that the introduction of double bond in the aliphatic chain of the stearic acid is possible although the yields of the unsaturated LCFAs are low. Effects of various parameters, such as temperature, pressure, and reaction time, were also investigated and reported.
Improvement of Prediction Errors Based on Standardized Infrared Spectra for a Calibration-free Approach
Authors: Shibayama Shojiro , Funatsu Kimito
Published: January 2021

Continuous manufacturing (CM) in the pharmaceutical industry has been paid attention to, because it is expected to reduce the costs of manufacturing. One of technical hurdles in CM is establishment and maintenance of predictive models for process monitoring. Conventionally, calibration models with optic spectra such as infrared or Raman spectra have been used as the predictive models for process monitoring. The calibrated models predict product qualities such as active pharmaceutical ingredient’s content, moisture content, particle size, and so on. However, any changes in rots, ratio of ingredients, or operation conditions may affect the relationship between sensor information and the product qualities, which results in deterioration of predictive models. Operators must update calibration models to assure predictive accuracy; however, calibration always requires data acquisition. Thus, the use of calibration models intrinsically increases economical costs. To tackle this problem, the authors have been attempting to propose a calibration-free approach with infrared spectra, which employs an equation in physics. To apply the calibration-free approach to real processes, it is important that a model provides accurate and reliable prediction. In this study, we propose a method to improve predictive accuracy of a calibration-free approach after assessing predictive errors using a rational indicator. We verified that the post-processing method succeeded in non-ideal binary mixtures.
Simulation of Dry Reforming of Methane to Form Synthesis Gas as Feed Stock for Acetic Acid Production
Authors: Sophiana Intan Clarissa , Adhi Tri Partono , Budhi Yogi Wibisono
Published: January 2021

The Natuna gas field is one of the largest natural gas reserves in Indonesia with estimated natural gas reserves of 222 TCF. However, until now, the use of Natuna gas is still hampered because of the very high CO2 content reaching 71%, while the methane content is around 28%. The dry reforming of methane (DRM) process is one of the potential ways to be applied for solving these problems to convert CH4 and CO2 to synthesis gas containing CO and H2 as a raw material that can be applied to manufacture as intermediate products or end products in the petrochemical industry such as acetic acid. The simulation of the acetic acid production was conducted by using ASPEN HYSYS v.10, considering mass and heat balances. The PengRobinson was applied for dry reforming of methane process. In order to produce 496.8 kmol/h of the acetic acid, the 500 kmol/h for each CH4 and CO2 were used as feed gas. The total energy required is 4.7 MMBtu per ton of acetic acid. The acetic acid has a purity of 99.4% with a concentration of 500 ppm methanol, and moisture content of 5,700 ppm.
The Performance of Adaptive Approach in Lean and Green Operations
Authors: Leong Wei Dong , Lam Hon Loong , Tan Chee Pin , Ponnambalam Sg
Published: January 2021

In recent years, the manufacturing sector has been pressured with global warming and resource scarcity. This issue has triggered the industry to seek for solutions to improve the sustainability of their production. Based on literature study, the main components of an organisation consists of manpower, machine, money, material and environment. Thus, the fundamentals need to be addressed to improve the production performance. In this study, an adaptive lean and green approach is presented to identify the priority areas that can improve the organisation performance. Backpropagation algorithm is incorporated into the adaptive model to analyse the dynamic performance of the organisation. However, the input of industry expert is required to prioritise the initial input of the main components. This is relatively important as prioritisation of main components defer from sectors. A case study will be illustrated with the adaptive lean and green model. Operation improvements shall be observed through the implementation of the proposed method.
Targeted Knock-in of Transgenes into the CHO Cell Genome Using CRISPR-mediated Integration Systems
Authors: Iwao Ryusei , Kawabe Yoshinori , Murakami Mai , Ito Akira , Kamihira Masamichi
Published: January 2021

Biopharmaceutical proteins are usually produced by culturing recombinant Chinese hamster ovary (CHO) cells. High producer cell lines are screened from transfected cells with random integration of target genes. Since transgene expression is susceptible to the surrounding environment of the integrated genomic locus, producer cell lines should be selected from a large number of recombinant cells with heterogeneous transgene insertion. In contrast, targeted integration into a characterized genomic locus allows for predictable transgene expression and less clonal variability, and thus stable production of target proteins can be expected. Genome editing technology based on programmable nucleases has recently emerged as a versatile tool for precise editing of target locus in the cell genome. Here, we demonstrated targeted knock-in of transgenes into the hypoxanthine phosphoribosyltransferase (hprt) locus of CHO cells using CRISPR/Cas9 and CRISPR-mediated precise integration into target chromosome (PITCh) systems. We also generated knock-in CHO cells based on the homology-independent targeted integration (HITI) system. We evaluated the knock-in efficiency of transgenes into the hprt locus using these systems.
Retrotransposon-mediated Gene Transfer for Animal Cells
Authors: Zheng Feiyang , Kawabe Yoshinori , Murakami Mai , Takahashi Mamika , Yoshida Shoichiro , Ito Akira , Kamihira Masamichi
Published: January 2021

Gene delivery methods for animal cells are one of the most important tools in biotechnology fields such as pharmaceutical protein production, generation of transgenic animals and gene therapy. Because retrotransposons can move their own sequences to new genomic locations by a “copy-and-paste” process known as retrotransposition, we attempted to develop a novel gene transfer system based on retrotransposon. A full-length long interspersed element-1 (LINE-1) contains a 5’ untranslated region (5’UTR), two non-overlapping open reading frames (ORFs) separated by a short inter-ORF sequence, and a 3’UTR terminating in an adenosine-rich tract. We constructed a LINE-1 vector plasmid including components necessary for retrotransposition. An intron-disruptedNeoreporter gene and a scFv-Fc expression unit under the control of CMV promoter were added into 3’UTR in order to evaluate retrotransposition and express scFv-Fc. CHO-K1 cells transfected with the plasmids were screened with G418. The established cell clones produced scFv-Fc proteins in the culture medium. To control retrotransposition steadily, we also established retrotransposon systems that supply ORF2 or ORF1–2 separately. Genomic PCR analysis revealed that transgene sequences derived from the LINE-1 vector were positive in all clones. All the clones tested produced scFv-Fc in the culture medium.
Preparation of Microporous Hydrogel Sponges for 3D Perfusion Culture of Mammalian Cells
Authors: Hori Aruto , Utoh Rie , Yamada Masumi , Seki Minoru
Published: January 2021

Three-dimensional (3D) perfusable organ models, primarily composed of liver cells, are expected as an efficient tool for in vitro cell-based drug screening and development. Various types of hydrogel-based 3D cell culture systems have been developed, but the lack in proper techniques to form vasculature networks in the hydrogel matrices results in inefficient supply of oxygen and nutrition to the cells. Here we propose a facile strategy to creating a perfusable hydrogel-based liver cell culture system. We utilized a bicontinuous dispersion of an aqueous two-phase system, which was composed of polyethylene glycol (PEG)-rich and gelatin methacrylate (GelMA)-rich phases, to produce cell-encapsulating microporous GelMA-based hydrogels. We successfully encapsulated HepG2 cells in the hydrogel matrix with a high cell viability, and confirmed that the spongious hydrogel was superior to homogeneous hydrogels for 3D cell culture. We performed perfusion culture for the cells encapsulated in the hydrogel sponge, to verify the usability and versatility of the presented hydrogel material for perfusion culture. The presented approach would be useful as a unique tool for developing organs-on-a-chip systems.
Potato Arabinogalactan Acts as Prebiotics by A Simple Extraction
Authors: Saito Masahiro , Konishi Masaaki
Published: January 2021

The effect of the extracting procedures for potato pulp arabinogalactan were investigated on the growth of gut-microflora by in vitro experiments. Crude saccharides (CS) were prepared by 50 g dried potato pulp suspended in 1 L of pure water. The suspensions were autoclaved at 1211C for 2 h, and filtered by a filter paper. The filtrate were concentrated around 1/4 by a rotary evaporator, and aggregated by 4× volume of ethanol. Dialyzed saccharides (DS) were prepared to dialyzed CS by a dialysis membrane (cut off MW < 10,000). Enzyme-treated saccharides (ES) were prepared to digest CS by a crude amylase, Gruku-Gin (Amano Enzyme) and dialyzed. All saccharides were lyophilized or heat-dried to store. According to size-exclusion chromatography, the molecular distribution of CS were between 400 and 200,000. A peak of oligosaccharides was observed around MW 800. The peak were disappeared in charts of DS and ES. Glucan were occupied 50% in the total amount of glycan in CS and DS, and decreased to approx. 5% in ES. When thirteen strains of gut microbes were cultivated in GAM broth including the saccharides instead of glucose, CP and EP selectively stimulated several non-pathogenic Bifidobacterium and Clostridium, but not pathogenic Enterobacteriaceae.
Oil Extraction from Rice Bran Using Expanded Liquid Hexane with CO2
Authors: Thi Le , Ly Thien , Okajima Idzumi , Yi Kong Chang , Sako Takeshi
Published: January 2021

Bio-oil is often extracted from biomass using liquid solvent or supercritical carbon dioxide. However, extraction using these methods has several disadvantages. In this study, expanded hexane with carbon dioxide is examined as a new extraction solvent. The objective of this study is to develop a new technique for the extraction of bio-oil from biomass using expanded hexane with carbon dioxide; rice bran is used as the raw biomass. The extraction was carried out at 25— 27°C, 5.0—5.3 MPa, and 0.78—0.94 mole fraction of carbon dioxide in expanded hexane. At 26°C, 5.1 MPa, 0.87 of mole fraction of carbon dioxide, the oil yield was 1.6 times greater than that with normal liquid hexane because of the low viscosity and high permeability of expanded hexane. Furthermore, the phosphorus concentration in the extracted oil was 9.5 ppm. This was very low, compared with that in rice bran,in which it is approximately 350 ppm. This was because the solvent power of expanded hexane to extract neutral lipid decreased slightly while that to extract polar components decreased significantly. As a result, expanded hexane with carbon dioxide could extract the phosphorus-free bio-oil in high yield under mild conditions.
Low Temperature Power Cycle Using Amine – CO2 Fluid
Authors: Ogawa Takashi , Mawatari Takashi , Itoh Akira , Yamamoto Yasushi
Published: January 2021

Low temperature heat below 473K is produced massively. Kalina cycle using NH3 and Organic Rankine cycle using HFC-245fa can generate electricity from the low temperature heat. However, the former is toxic and corrosive and the latter has a high GWP value, which is required to reduce by the Kigali amendment to the Montreal Protocol and the Regulation (EU) No 517/2014. The thermodynamic simulation shows the maximum power of the low temperature cycle using 30 mass% MDEA-H2O solution (CO2/MDEA mole ratio: 0.15) is equal to that of the Organic Rankine cycle using HFC245fa. The experimental results suggest the low temperature cycle using the MDEA-based solution containing carbon dioxide is available as a low temperature cycle.
Synthesis and Characterization of a Novel Heteropoly Acid/Hydrogel Composite
Authors: Zhu Junjie , Gotoh Takehiko , Nakai Satoshi , Sadakane Masahiro
Published: January 2021

Catalysis by Heteropoly acids (HPAs) and polyoxometalates (POMs) having a higher demand worldwide, as it can be designed to accelerate complex reactions and be more environmentally friendly. However, recycling of water-soluble solid catalysts remains a problem. The synthesis of a recyclable composite with catalytic properties is the key to better use of HPAs and POMs. Many researches have mentioned the method of synthesis by immersing a porous carrier in a supported solution. However, the catalytic stabilities of the previously studied composites after multiple uses have rarely been mentioned. In this research, a novel idea is proposed to synthesize a heteropoly acid supported composite. A complex hydrogel with catalytic properties was synthesized by mixing an anionic monomer with a heteropoly acid. The heteropoly acid particles were inserted inside the hydrogel by the interaction forces between the anions. Thus, preventing the water-soluble heteropoly acid from being lost during the catalytic reaction. The complex hydrogel is consisted of the anionic monomer 2-acrylamide-2methylpropanesulfonic acid (AMPS) as a carrier, N,N’-Methylenebisacrylamide (MBAA) as crosslinkers and the typical Keggin-type HPA: H3PW12O40. At last, a composite with (NH4)3PW12O40 particles was synthesized.
Simultaneous Adsorption of Cation and Anion by Thermosensitive Hydrogels
Authors: Suharto Toni , Goto Takehiko , Nakai Satoshi
Published: January 2021

Simultaneous usage of cationic and anionic thermosensitive hydrogels was shown to positively contribute to adsorption of heavy metal ions. The potential capacity for recovering heavy metal ions from an aqueous solution was enhanced by incorporating relatively hydrophobic moiety to the hydrogels, which was ascribed to the increase in the desorption on elevating the temperature over the lower critical swelling temperature (LCST). N-tert-butylacrilamide was added into the hydrogels to increase its desorption potential. The addition of N-tert-butylacrylamide does not significantly affect hydrogels’ adsorption ability. Moreover, the adsorption-desorption cycle was not diminished by repeating the temperature swing above the critical temperature at which the volume phase transition was induced.
Evaluation Method of Emulsion Using Chemical Oxygen Demand
Authors: Amagu Kaiki , Okajima Riho , Shimizu Moe , Nishimoto Makoto , Nagayama Kazuhito , Hata Takashi , Nishiuchi Yusuke , Tada Kaori
Published: January 2021

The “gas–liquid two-phases mixed flow” mechanism that fine bubble generation uses rapidly swirling water, which shear gas and making small bubbles in water. Based on this mechanism, sending liquid such as oil into the swirling water instead of gas and it able to be emulsified. At present, evaluation methods for emulsions are using particle size distribution and dispersion stability. However, the emulsion with bad separation behavior has a problem to catch only some dispersed oil particles and use them as a whole evaluation. In this study we examined emulsion evaluated by chemical oxygen demand (COD) to express numerical evaluation including the oil particles that cannot be dispersed. Using three emulsions of only one oil, an anionic and a nonionic emulsifier were mixed and added to the oil, an anionic and another kind of the nonionic emulsifier were mixed and added to the oil. It was confirmed that COD decreased and type of only one oil was the most evaporate. These results lead to the conclusion that the performance of the emulsion could be expressed numerically, including the oil particles which could not be dispersed. We also directly analyzed evaporate components and compared them with COD results.
Design and Optimisation of Wastewater Treatment Plant for the Poultry Industry
Authors: Ma Rui , Chong Chien Hwa , Foo Dominic C. Y.
Published: January 2021

The objective of this study is to optimise the wastewater treatment plant of poultry industry. The optimisation of simulation model was done using the SuperPRO designer as simulator. The performance of the wastewater treatment plant for the poultry industry has improved significantly at the minimum cost. The COD value reduced from 133 mg/L to 0.05 mg/L at the discharge stream 1 and 73.7 mg/L for discharge stream 2. In addition, the BOD5 value reduced from 66.7 mg/L to 0.03 mg/L at the discharge stream 1 and 47.1 mg/L at the discharge stream 2. Further to this, the TTS reduced from 33.3 mg/L to 0.0 mg/L at the discharge stream 1 and 1.69 mg/L at the discharge stream 2. Oil and grease also reduced from 3.3 mg/L to 0.024 mg/L at the discharge stream 1 and 18.7 mg/L at the discharge stream 2. The existing model and system can improve the wastewater treatment plant of poultry industry.
Reusability of Ni2Fe3 Metal Catalyst for Upgrading Pyrolyzed Bio-Oil from Cellulose
Authors: Li Siyi , Cross Jeffrey S.
Published: January 2021

Recyclable catalysts are desperately needed for upgrading pyrolyzed bio-oil which is produced from biomass conversion in order to reduce cost and protect the environment. However, most catalysts used for producing bio-oil from the pyrolysis of biomass cannot be recycled, leading to costly catalyst regeneration or waste if disposed of. In this study, Ni2Fe3 has been chosen as the model catalyst to test the recyclable property of the metal cluster catalyst system. Cellulose is used as the biomass model reactant. The results from pyrolysis experiments and GC-MS show that the catalytic property of Ni2Fe3 remains constant even after repeated experiments. From the analysis of bio-oil by GC-MS, the catalyst even shows slightly better performance with repeated use due to the pyrolytic interaction with cellulose during the experiment.
Development of Test Equipment for the Performance Evaluation of a Dust Monitor Used in Soot and Smoke Generating Facilities
Authors: Wada Masashi , Tsuji Masashi , Kayahara Fujio , Averdieck William
Published: January 2021

A dust monitor is a device that measures dust concentration continuously in a flue gas. In Europe, a certification system has been established by TÜV and MCERT, and if formal certification is obtained by those system, it will be legally recognized as a continuous monitoring system of dust concentration from the facilities. In Japan, emission regulations have been introduced under the Air Pollution Control Act to monitor the emission of dust from facilities. Although the Act does not currently permit the use of dust monitors for dust concentration measurements, the related JIS standards have promoted above method’s introduction. In this work, flue test equipment aiming at the construction of a performance evaluation system of various dust monitors was developed to secure accurate dust concentration measurements for dust monitor management. As a result, increase in the diameter of the flue, optimization of rectification and dust generation, and improvement of the evaluation component made it possible to respond to the evaluation of dust monitors. The device was equipped to generate gas containing dust with any concentration in a constant velocity flow. It could evaluate the correlation between the analysis values of JIS Z 8808: 2013 and those of various dust monitors.
Simulation for All-Solid State Batteries with Multi-Element Network Model
Authors: Hirate Ryusei , Mashioka Hiroki , Yano Shinichiro , Tsuge Yoshifumi , Inoue Gen
Published: January 2021

In order to increase energy density and enhance safety, all-solid-sate lithium-ion batteries have been developed as a storage battery for electric vehicle (EV). Further performance improvement of all-solid-sate lithium-ion batteries requires optimization of the electrode structure. In this paper, we constructed a phase interface model focusing on the microstructure of the porous electrode, and examined the reaction of the electrode layer structure.
Experimental analysis of process parameters in drilling nimonic C263 alloy under nano fluid mixed MQL environment
Authors: Ezilarasan Chakaravarthy , Nagaraj Meenaskshi Sundaram , Kumar A. John Presin , Velayudham A. , Betala Rishab
Published: January 2021

Nimonic C263 is a super alloy and it is difficult to cut. As this alloy possess high proportion of chromium, cobalt, and molybdenum, which fortify the material by solution hardening, which inhibits the dislocation movement, resulting in higher plastic deformation. In this research, an attempt has been made to model, analysis and investigate the machining characteristics such as thrust force, temperature at drill cutting edge, flank wear and surface finish during drilling of this alloy using silver nano fluid mixed Minimum Quantity Lubrication (MQL) environment. Residual stress at various combinations of process parameters was also observed and discussed. RSM based empirical models of the process parameters and optimization of multi response was developed. Thrust force, Temperature at drill cutting edge, surface roughness and tool wear affected by feed rate (percentage of contribution-60%), spindle speed (percentage of contribution-88.63%), spindle speed (percentage of contribution-71.42%) and feed rate (percentage of contribution-67.76%) respectively followed by other parameters.
Very low prevalence of Opisthorchis viverrini s.l. cercariae in Bithynia siamensis siamensis snails from the canal network system in the Bangkok Metropolitan Region, Thailand
Authors: Rachprakhon Phuphitchan , Purivirojkul Watchariya
Published: January 2021

The liver fluke Opisthorchis viverrini s.l. is associated with a long-term public health problem in Thailand. However, O. viverrini s.l. infection in Bithynia snails in the canal network system (CNS) in the Bangkok Metropolitan Region (BMR) has never been assessed. This study aimed to investigate the occurrence of B. siamensis siamensis and the prevalence of O. viverrini s.l. infection in this snail in the CNS in BMR along with morphological examination and molecular analyses on O. viverrini s.l. cercariae. The snails were randomly sampled from the CNS in all BMR areas from January 2018 to July 2019. Snail specimens were identified and examined for digenean infection by shedding and dissection. The cercariae were identified using morphology and molecular methods, including PCR with a species-specific primer and a Bayesian phylogenetic analysis of ITS2 sequences. Bithynia siamensis siamensis was found in almost all sampling localities, with different quantities and detected frequencies. From a total of 7473 B. s. siamensis specimens, O. viverrini s.l. infections were detected in the Northern Bangkok, Muang Nakhon Pathom, Krathum Baen, and Lam Luk Ka areas with an overall prevalence of 0.05% (4/7473) and prevalence of 0.22% (1/455), 0.21% (1/469), 0.40% (1/253), and 0.16% (1/614) in individual localities with positive snails, respectively. This study is the first investigation of digenean infection in the canal network system-type habitat in Thailand and revealed extremely low O. viverrini s.l. prevalence.
Intraosseous schwannoma of the glenoid: case report and literature review
Authors: Reyniers Pieter , Wafa Hazem , Sinnaeve Friedl , Debeer Philippe , Sciot Raf
Published: January 2021

Intraosseous schwannomas represent an extremely rare subgroup of schwannomas, accounting for <1% of all primary bone tumors. They mostly occur in the mandible, the maxilla, the sacrum, and they are also seen in long bones. We herein report a rare presentation of an intraosseous schwannoma in the glenoid of a 49-year-old patient. She complained of shoulder pain and was referred to the orthopaedic oncologist after detection of a suspicious lesion on imaging. Biopsy revealed benign spindle cells and immunohistochemistry was positive for S100. Because of the rarity of these intraosseous schwannomas it is important to recognize their radiological and histological features and make a differential diagnosis with other lytic tumors. Only if these characteristics are recognized, correct treatment can be given with definite curettage and bone grafting and correct follow-up with avoidance of unnecessary adjuvant therapy.
La danse thérapie pour développer les dimensions perceptives chez les patients obèses
Authors: Muller-Pinget Solange , Golay Alain
Published: January 2021

Introduction : Les patients obèses sont enfermés dans une perception d’eux-mêmes amoindrie par le poids de leurs souffrances. Objectifs : Le but de cette étude est d’observer les effets de la danse thérapie sur l’auto-perception et la qualité de vies des patients obèses et ceux ayant bénéficié d’une chirurgie bariatrique. Méthodes : Quatre groupes, similaires en poids et en âge, ont bénéficié de danse thérapie. Un programme de 36 semaines sans groupe contrôle, un de 16 semaines avec groupe contrôle et un groupe post bypass pendant 18 semaines. L’estime de soi, l’estime corporelle, la qualité de vie, la conscience corporelle, les représentations mentales et la représentation de la corpulence ont été mesurés avant et après la danse thérapie dans chaque groupe. Résultats : La danse thérapie améliore tous ces éléments dans les trois programmes sauf la représentation de la corpulence qui reste inadéquate dans les quatre groupes. Le groupe contrôle n’améliore pas la qualité de vie ni l’estime de soi. Conclusion : Les séances de danse thérapie sur une longue ou courte période engagent une transformation de la perception de la personne qui lui permet une amélioration de sa qualité de vie.
Predicting attractor characteristics using Lyapunov exponents in a laser with injected signal
Authors: Bandy D. K. , Burton E. K. T. , Hall J. R. , Chapman D. M. , Elrod J. T.
Published: January 2021

Coexisting attractors are studied in a single-mode coherent model of a laser with an injected signal. We report that every attractor has a unique Lyapunov exponent (LE) pattern that is choreographed by the subtle variations in the attractor's dynamics and circumscribed by a common Lyapunov spectral pattern that begins and ends with two-zero LEs. Lyapunov spectra form symmetric-like and asymmetric bubbles; the former foreshadows an attractor's proximity to the cusp of an eminent change in dynamics and the latter indicates the presence of a bifurcation. We show that the peak values of the asymmetric bubbles are always associated with two-zero LEs; in fact, they are allied inseparably in forecasting period-doubling episodes. The two-zero LEs’ predictor of torus dynamics is refined to include the convergence of three LEs to a triplet of zeros as a precursor to the two-zero spectra. We report that the long-standing two-zero LEs’ signature is a necessary but not sufficient condition for predicting attractors and their dynamic conditions. The evolution of the attractor volume as a function of the injected signal is compared to the spectral formation of the attractor; we report slope changes and points of inflections in the volume trajectory where spectral changes indicate dynamic changes. Attractor viability is tested preliminarily by including random low-level noise in the frequency of the injected signal.
Active control of resistive wall mode via modification of external tearing index
Authors: He Yuling , Liu Yueqiang , Yang Xu , Xia Guoliang , Li Li
Published: January 2021

Modification of the external tearing index, Δext′, by magnetic feedback is analytically investigated for the purpose of controlling the resistive plasma resistive wall mode (RP-RWM). The matching method is pursued by deriving expressions for the close-loop Δext′ and by linking it to the counterpart from the inner layer. Various feedback coil configurations are found to generally reduce Δext′ and stabilize the RWM, with either proportional or derivative control. Feedback modification of Δext′ is found to be generally independent of the inner layer resistive interchange index DR, confirming that feedback action primarily modifies the solution in the outer ideal region for the RP-RWM. Exception occurs when either the inner layer favorable curvature effect becomes sufficiently large or the feedback action is sufficiently strong to introduce a rotating RP-RWM in the static plasma, leading to complex-valued close-loop Δext′. The perturbed magnetic energy dissipation in the outer region, associated with the eddy current in the resistive wall, is identified as the key physics reason for feedback induced complex Δext′. Similar results are also obtained for active control of the external kink instability, whose open-loop growth rate is significantly reduced by inclusion of the plasma resistivity. Within the single poloidal harmonic approximation, which is most suitable for the matching approach, external active coils combined with poloidal sensors are often found to be more efficient for feedback stabilization of the mode at large proportional gain values. This counter-intuitive result is explained as the lack of (non-resonant) poloidal harmonics for proper description of the feedback coil geometry.
Annealing studies combined with low temperature emission Mössbauer spectroscopy of short-lived parent isotopes: Determination of local Debye–Waller factors
Authors: Gunnlaugsson H. P. , Masenda H. , Mølholt T. E. , Bharuth-Ram K. , Ólafsson S. , Johnston K. , Schell J. , Gislason H. P. , Krastev P. B. , Mantovan R. , Naidoo D. , Qi B. , Unzueta I.
Published: January 2021

An extension of the online implantation chamber used for emission Mössbauer Spectroscopy (eMS) at ISOLDE/CERN that allows for quick removal of samples for offline low temperature studies is briefly described. We demonstrate how online eMS data obtained during implantation at temperatures between 300 K and 650 K of short-lived parent isotopes combined with rapid cooling and offline eMS measurements during the decay of the parent isotope can give detailed information on the binding properties of the Mössbauer probe in the lattice. This approach has been applied to study the properties of Sn impurities in ZnO following implantation of 119In (T½ = 2.4 min). Sn in the 4+ and 2+ charge states is observed. Above T > 600 K, Sn2+ is observed and is ascribed to Sn on regular Zn sites, while Sn2+ detected at T < 600 K is due to Sn in local amorphous regions. A new annealing stage is reported at T ≈ 550 K, characterized by changes in the Sn4+ emission profile, and is attributed to the annihilation of close Frenkel pairs.
Reconfigurable locally resonant surface acoustic demultiplexing behavior in ZnO-based phononic crystal
Authors: Taleb F. , Darbari S. , Khelif A.
Published: January 2021

We present the design and numerical investigation of a reconfigurable and miniature locally resonant surface acoustic wave demultiplexer based on a ZnO pillar phononic crystal, for the first time. Hollow cylinder line defects are used as waveguides, due to their good structural controllability over the local resonant waveguiding frequency and bandwidth. Two local resonant surface acoustic waveguides are designed and simulated as the output channels of the demultiplexer, and the shear-horizontal wave transmission spectra are calculated for each channel individually. The designed radio frequency demultiplexing output channels support frequencies of 4.14 GHz and 4.28 GHz, with respective bandwidths of 40 MHz and 60 MHz, while their spatial separation is just about 800 nm. In order to achieve a reconfigurable output characteristic, the effect of acoustoelectric interaction in piezoelectric semiconductors is numerically simulated in this study. The acoustoelectric interaction causes an additional stiffness in ZnO that can be released by adding extra charge carriers, i.e., increasing conductivity, thus changing the effective elasticity of the ZnO structures and the guiding frequencies of the output channels. Two output frequencies show red shifts of about 100 MHz and 150 MHz by extremely increasing the conductivity of ZnO structures from 0.01 S/m to 100 S/m.
Improvement in the spatial resolution of heavy ion beam probe measurements through application of ion optics
Authors: Crowley T. P. , Demers D. R. , Fimognari P. J.
Published: January 2021

A technique for more accurately modeling and improving the spatial resolution of heavy ion beam probe measurements is described. We use a set of particle trajectories to numerically determine the focusing properties of a complicated three-dimensional magnetic field and characterize these properties with a transfer matrix. We then modify the transfer matrix approach of traditional ion optics to include a parameter that describes the ionization location of the detected ions. The ion optics model calculated using this technique enables a more accurate description of the particle trajectories than previously feasible. The model also allows one to easily determine an initial beam focus that could be used during experimental operation to optimize the spatial resolution of measurements. The technique has been applied to the design of a heavy ion beam probe diagnostic for the Wendelstein 7-X stellarator, and improvements in the modeled spatial resolution by a factor of about 2 over previous estimates are possible. The improved spatial resolution will enable measurements of plasma fluctuations with smaller wavelengths than would otherwise be possible.
Ordering behavior and electric response of a ferroelectric nano-doped liquid crystal with ion impurity effects
Authors: Shoarinejad Saeedeh , Mohammadi Siahboomi Roshanak
Published: January 2021

We present a theoretical study of the simultaneous effects of ferroelectric nanoparticles and ion impurities on the order parameter of liquid crystals. We have focused on the effect of ion impurities on the ordering behavior and electrical response of a ferroelectric nano-doped liquid crystal near the nematic-isotropic phase transition. In this study, a statistical theory based on the orientational distribution of the nanoparticle dopants is used. We have performed the calculations using the Poisson–Boltzmann equation and a modified Landau-De Gennes model. The total density of free energy of the system is obtained within the framework of this theory, and the changes in the concentration of mobile ions due to the presence of ferroelectric nanoparticles are investigated. It is shown that the screening effect of the ion impurities plays a dominant role in the ordering behavior and electrical response of a ferroelectric nano-doped liquid crystal. The ion generation and the consequent changes are also described in some physical properties of a nano-doped system under an applied electric field.
Hybrid printed three-dimensionally integrated micro-supercapacitors for compact on-chip application
Authors: Hu Jingzhi , Luo Jun , Xu Zhaohua , Xie Keyu , Yu Haoran , Wang Hanming , Shen Chao , Qi Le-hua , Wei Bingqing
Published: January 2021

The emerging internet of things requires autonomous and ubiquitous on-chip devices with wireless interconnectivity. On-chip power is required to meet the miniaturization requirement, and an integrated on-chip micro-supercapacitor has enormous potential to meet this requirement owing to its high-power density and long cycle life. However, the two-dimensional expansion of the current co-planer design paradigm of micro-supercapacitors, such as the interdigital layout, hinders the on-chip integration density, resulting in a significant consumption of precious chip footprint and an insufficient energy density. This article reports on the use of a three-dimensional framework along with a hybrid printing strategy to fabricate devices entirely without any post-processing, and highly integrated three-dimensional micro-supercapacitors were printed as proof of concept. The micro-supercapacitors exhibit more than 25 times areal capacitance than the interdigital ones (76 mF/cm2 vs 2.9 mF/cm2) due to their three-dimensional feature. Moreover, it can provide new functions to achieve adjustable voltage and capacitance flexibility within one device's footprint area. This approach can also enable devices on different substrates. An ultraviolet sensor was integrated with and powered by the three-dimensional micro-supercapacitors on polyimide to demonstrate the compact on-chip application. The three-dimensional framework offers a general solution to the on-chip integration challenges of micro-supercapacitors. Moreover, it can be extended to new materials or even other electronics units, highlighting the promise of further miniaturized and powerful micro-electronics.
Temperature dependence of the energy barrier in X/1X nm shape-anisotropy magnetic tunnel junctions
Authors: Igarashi Junta , Jinnai Butsurin , Desbuis Valentin , Mangin Stéphane , Fukami Shunsuke , Ohno Hideo
Published: January 2021

Shape-anisotropy magnetic tunnel junctions (MTJs) are attracting much attention as a high-performance nonvolatile spintronic device in the X/1X nm regime. In this study, we investigate an energy barrier relevant to the retention property in CoFeB/MgO-based shape-anisotropy MTJs with various diameters at high temperatures and compare it with that in conventional interfacial-anisotropy MTJs. We find that the scaling relationship between the energy barrier and the spontaneous magnetization in shape-anisotropy MTJs is well described by a model assuming the dominant contribution of shape anisotropy to the energy barrier. Also, the scaling exponent is much smaller than that for the interfacial-anisotropy MTJs, indicating that the properties of shape-anisotropy MTJs are less sensitive to the temperature. Using the experimentally determined scaling relationship, we discuss the design window of the MTJ dimensions to achieve data retention of 10 years at various temperatures. This study demonstrates that the shape-anisotropy MTJ holds promise of scaling beyond 20 nm for high-temperature applications.
Response of CR-39 nuclear track detectors to protons with non-normal incidence
Authors: Przybocki R. , Johnson M. Gatu , Sutcliffe G. , Lahmann B. , Seguin F. H. , Frenje J. , Adrian P. , Johnson T. M. , Pearcy J. , Kabadi N. V. , Birkel A. , Petrasso R. D.
Published: January 2021

This paper presents data from experiments with protons at non-normal incidence to CR-39 nuclear track detectors, analyzing the properties of detection efficiency, proton track diameter, track contrast, and track eccentricity. Understanding the CR-39 response to protons incident at an angle is important for designing charged particle detectors for inertial confinement fusion (ICF) applications. This study considers protons with incident energies less than 3 MeV. In this regime, an incident angle of 10° has no effect on CR-39 detection efficiency, and >85% detection efficiency is preserved up through 25° in the range of 1.0 MeV–2.1 MeV. For ICF applications, incident angles above 30° are deemed impractical for detector design due to significant drops in proton detection at all energies. We observe significant reductions in detection efficiency compared to theoretical predictions, particularly at low energies where proton tracks are etched away. The proton track diameter measured by the scan system is observed to decrease with higher incident angles. The track diameters are analyzed with two fitting models, and it is shown that the diameter–energy relation can be fit with the existing models at angles up to 30°. The optical contrast of the tracks tends to increase with the angle, meaning that the tracks are fainter, and a larger increase is observed for higher energies. Eccentricity, a measure of how elongated proton tracks are, increases with the incident angle and drops after the critical angle. The lowest energy tracks remain nearly circular even at higher angles.
A new excitation mechanism of He+ band electromagnetic ion cyclotron wave: Hybrid simulation study
Authors: Yao Jiansheng , Zhao Yingkui , Li Yi , Chai Lihui , Sun Jicheng
Published: January 2021

A new excitation mechanism of the He+ band electromagnetic ion cyclotron (EMIC) wave is proposed in this paper. Through 1D hybrid simulation, we find that the frequency of the H+ band EMIC wave triggered by anisotropic hot H+ drops quickly in the initial stage, and then, a narrow He+ band EMIC wave is excited. Meanwhile, the temperature of ions also changes significantly. Using the linear kinetic theory, we have proved that the temperature variance cannot stimulate the He+ band EMIC wave. Hybrid simulation results show that the distribution of He+ is changed to be X-type during this process. Further investigation confirms that X-type distributed He+ may be caused via the pitch angle scattering by the H+ band EMIC wave, which stimulates the He+ band EMIC wave. Beyond that, further research shows that the free energy to excite the He+ band EMIC wave comes from higher energy He+ with a butterfly wing shaped part of X type distribution.
Inertial self-propelled particles
Authors: Caprini Lorenzo , Marini Bettolo Marconi Umberto
Published: January 2021

We study how inertia affects the behavior of self-propelled particles moving through a viscous solvent by employing the underdamped version of the active Ornstein–Uhlenbeck model. We consider both potential-free and harmonically confined underdamped active particles and investigate how the single-particle trajectories change as the drag coefficient is varied. In both cases, we obtain the matrix of correlations between the position, velocity, and self-propulsion and the explicit form of the steady-state probability distribution function. Our results reveal the existence of marked equal-time correlations between velocity and active force in the non-equilibrium steady state. Inertia also affects the time-dependent properties of the active particles and leads to non-monotonic decay of the two-time correlation functions of particle positions and velocities. We also study how the virial pressure of particles confined to harmonic traps changes as one goes from the overdamped to the underdamped regime. Finally, the study of the correlations in the underdamped regime is extended to the case of a chain of active particles interacting via harmonic springs.
Magnetic-field generation and its effect on ablative Rayleigh–Taylor instability in diffusive ablation fronts
Authors: García-Rubio F. , Betti R. , Sanz J. , Aluie H.
Published: January 2021

The effects of self-generated magnetic fields on the ablative Rayleigh–Taylor (RT) instability are investigated in the linear regime. The main governing parameters are the Froude number (Fr), which stands for the ratio between ablative convection and acceleration of the target, and the Mach number at the ablation front (Ma), assumed to be small (isobaricity). During the development of the RT instability, magnetic fields are generated due to misalignment between pressure and density gradients (Biermann-battery effect). They accumulate at the section of the ablation front where the Nernst and the plasma velocities cancel each other. The magnetic field modifies the dynamics of the instability through the Righi–Leduc term, which acts as a heat source in the energy equation. It is found that the B fields affect perturbations with short wavelengths up to the most unstable wave in the spectrum. The B field plays a destabilizing role for moderate Froude numbers and becomes stabilizing for large Froude numbers. For plastic ablators, the Fr threshold is found to be Fr=5.
Experimental validation of the Active Shielding Particle Pusher code
Authors: Stegeman L. , Pal Chowdhury R. , Fry D. , Lund M. L. , Madzunkov S. , Belousov A. , Bahadori A. A.
Published: January 2021

Passive radiation shielding alone is insufficient for protecting astronauts from galactic cosmic ray exposure. Active shields, utilizing electromagnetic fields to deflect heavy charged ions in space, could be used to supplement conventional passive shielding. Due to experimental limitations, simulation capability is crucial for designing effective active shields. The purpose of this work is to validate the Active Shielding Particle Pusher (ASPP) code, used to characterize active shielding efficacy, using beamline measurements conducted at the Brookhaven National Laboratory. Emphasis is placed on (1) comparing shielding efficacy as a function of a scaled dimensionless parameter among various electric dipole sphere sizes and center-to-center distances, (2) comparing shielding efficacy as a function of dipole rotation angle as the voltage applied to each sphere is varied independently, and (3) comparing shielding efficacy observed in measurements and simulations to broaden the validation domain of ASPP. Simulated and measured shielding efficacy data are shown to agree within a factor of 1.10 on average. The results of this work demonstrate that dimensionless scaling of parameters characteristic of the active shield and incident radiation can be used to create scaling laws for a range of ion species relevant for protecting astronauts from galactic cosmic ray exposure at beamline energies.
High-order gas kinetic flux solver for simulation of two dimensional incompressible flows
Authors: Yang L. M. , Shu C. , Chen Z. , Liu Y. Y. , Wang Y. , Shen X.
Published: January 2021

Within the framework of the high-order finite volume (FV) method, a high-order gas kinetic flux solver (GKFS) is developed in this work for simulation of two-dimensional incompressible flows. Generally, in the conventional high-order FV method, the inviscid and viscous fluxes are treated separately. However, different from the conventional high-order FV method, the high-order GKFS evaluates the inviscid and viscous fluxes simultaneously from the local asymptotic solution to the Boltzmann equation, which consists of the equilibrium distribution function and its substantial derivative at the cell interface. By introducing a difference scheme with the high-order accuracy in space to discretize the substantial derivative, a high-order accurate local asymptotic solution to the Boltzmann equation can be obtained. The numerical flux of the Navier–Stokes equations can then be calculated by the moments of the local asymptotic solution. Since this local asymptotic solution is relatively simple, the numerical fluxes of the Navier–Stokes equations can be given explicitly for the high-order GKFS, which is the function of the left and the right states and their first-order derivatives. Numerical results showed that the developed solver can achieve the desired accuracy on both the quadrilateral mesh and the triangular mesh and its efficiency is higher than the second-order counterpart when achieving comparable accuracy of solution.