bluuebunny/crossref_metadata_2025 huggingface dataset:
The influence of nanosized iron particles on morphological parameters of blood and reproductive ability of sows in the third trimester of gestation
Authors: Kashirina Lydia , Kulakov Vitaly , Saitkhanov Elman , Denikin Sergey
Published: July 2021

The article presents the results of experimental studies on the use of nanosized iron powder in the third trimester of gestation on the reproduction processes of sows. The studies were carried out in the conditions of the farm. The physiological state of pregnant sows was determined by hematological parameters. It was found that iron NRP contributed to an increase in the number of red blood cells and hemoglobin in the blood of sows, compared with the control 20 days before farrowing, the content of red blood cells in the blood of experimental sows was 6.3% significantly higher compared to the control, and hemoglobin by 3.8 %. For 10 days, before farrowing, respectively, by 6.9 % and 5.2% higher. The indicators that characterize the reproductive ability of sows are: multiplicity, large fertility, the number of piglets in the nest and their average live weight. The use of ultrafine iron powder in the diets of pregnant sows in the third trimester of gestation contributed to the improvement of the overall physiological state, confirmed by the improvement of hematological parameters and had a positive effect on reproductive ability. The weight of the nest in the experimental group of sows on the day of farrowing was 4.1 % higher, the large-fruiting rate was 3.1 %, compared to the control animals.
Using the microflora of grapes for the production of young sparkling wines
Authors: Lutkov Igor
Published: July 2021

In order to meet the growing demand for ecological products, it is necessary to conduct research on the impact of technological methods of organic winemaking on the quality of finished products. The possibility of preparing high-quality young sparkling wines using wild microflora of Cabernet Sauvignon grapes grown in the conditions of the southern coast of the Crimea without the use of pesticides was studied. The analysis of physical and chemical parameters of sparkling wines was carried out with the help of generally accepted in enochemistry and modified methods of analysis. The use of wild microflora contributes to a greater accumulation of glycerol (by 12-19%), amine nitrogen (by 18%), polyphenols (by 14-17%), the formation of combined forms of carbon dioxide (by 1.2%), better foaming (by 4-8%) and sparkling properties (by 2-3 times) in finished sparkling wines than in control samples. However, fermentation on wild microflora may do not go to the end, which leads to the appearance of undesirable sauerkraut tones. Control samples prepared using pure yeast culture “Odessa black SD13” had a pure varietal aroma and harmonious taste. To improve the bouquet and taste of young sparkling wines produced using wild microflora, it is necessary to select promising strains of wild yeast Saccharomyces cerevisiae, suitable for champagnization. The technology under study can be applied in small enterprises without the use of complex technological equipment. The introduction of this technology will help to increase the total output of sparkling wines.
The influence of the moisture weight ratio and the activity of the invertase enzyme on the crystallization rate of natural honey
Authors: Murashova E. A. , Karelina O. A. , Serebryakova O. V.
Published: July 2021

The article presents studies on the dependence of the crystallization rate of natural honey on the moisture weight ratio, the activity of the invertase enzyme. Based on the results presented, preliminary conclusions can be drawn, which indicate that the higher the activity of the invertase enzyme, the sooner the crystallization of the honey begins.
Researching the Possibility of Using Sediments in Forest Reclamation of Disturbed Lands
Authors: Gordeeva T. Kh. , Malyuta O. V. , Yatmanova N. M. , Labatorina O. S. , Ibadullayev Meyrbek Uskenbay ugli
Published: July 2021

The research of the physico-chemical, biological and toxicological parameters of sediments and soils reclaimed by them, as well as the analysis of the growth of Scots pine seedlings, suggests that the use of sediments as a soil ameliorant at forest reclamation sites is advisable.
Analysis of technical and operational indicators of machines for planting seedlings
Authors: Vinevskiy Yevgeniy I. , Lopatin Vladislav S.
Published: July 2021

The purpose of the analysis of machines for planting seedlings produced by various manufacturers was to determine the best ratio of balance prices and labor costs for machine planting of seedlings. It was established that the highest competitiveness coefficient was obtained for a 4-row planting machine with a carousel planting apparatus.
Search for rational ratio of maximum speed and minimum fuel consumption of the vehicle
Authors: Sidorov Maxim , Eliseev Igor , Sidorov Vladimir , Golubina Svetlana
Published: July 2021

The gear ratio of the final drive and the distribution of the vehicle mass along the axles has a great influence on the technical and operational parameters of the vehicle. The article discusses the use of mathematical modelling in the MATLAB Simulink and the planning of the experiment to identify the optimal values of the final drive ratio and the mass distribution along the axles when driving a vehicle on a horizontal reference surface. A computational model for determining the moment of resistance on the wheels is developed when the vehicle moves along a supporting surface without slopes. The roughness and unevenness of the surface were not taken into account in the above model. The response function is obtained by studying the dependence of change in two parameters: the speed and fuel consumption of the car from two factors of variation: the final drive ratio and the mass distribution along the axles. The steep ascent method is used to determine the optimal parameters of the vehicle design, which allow achieving maximum speed with minimum fuel consumption when the vehicle is moving on a horizontal supporting surface.
Calculation of engine power for a tractor of traction class 1.4 with a technological module
Authors: Sidorov Maksim , Lavrov Alexander , Voronin Victor , Sidorova Anastasia
Published: July 2021

The technological provision of peasant farms is characterized by a deficit in their fleet of tractors of classes 2, 3. As a promising direction for solving this problem, it is proposed to develop a technological module that allows increasing the versatility of class 1.4 tractors by transferring them to a higher traction class. To calculate the rated power of the engine of a tractor of class 1.4, when operating it with a technological module, a method is proposed that takes into account the design features of the modular construction of a machine-tractor unit.
Development automated capture device for picking apples
Authors: Khort Dmitriy , Kutyrev Alexey , Smirnov Igor , Pupin Daniil
Published: July 2021

In the system of the mechanized process of cultivation of fruit crops, harvesting is an important final stage, which requires the development of new, convenient, including those that do not damage the fruit, automated technical devices. As a result of a series of experiments, the operability of the developed automated fruit picking device was confirmed, it gently captures the fruit and reliably holds it. The operating modes of the automated device for picking fruits have been established. The following characteristics of the device for picking fruits were revealed: the time for a complete capture of the apple is from 1.5 seconds to 2 seconds, depending on their size, the maximum size of the captured apple is 85x80 mm, the maximum weight of the captured apple is 400 g. The permissible pressure of the paws of the device on the fruit is determined ... It was found that with the force of the linear stepper motor on the pusher in 8N, the safety of the apple is ensured with minimal damage, while the apple is securely fixed in the capture paws.
Analitical definition of the law of change in the traction resistance of the plowshare and justification of its model
Authors: Tsybulevsky V. V. , Rudnev S. G. , Poluektov A. A.
Published: July 2021

An analytical definition of the law of change in the traction resistance of the plowshare is proposed, and its mathematical model is justified. To confirm these theoretical studies, experiments were conducted in the soil channel of the North-Caucasus Research Institute of Horticulture and Viticulture. According to a specially developed program, solutions in numerical form were carried out on a PC. To solve this problem, we used the Fourier, Sturm-Liouville equations, transformed from the polar system to the Cartesian system. The results obtained for the first eight harmonics were processed by the spline-approximation program, and then a regression analysis was performed. The pair correlation coefficient was calculated. Based on the obtained values, a graph of the dependence of the soil layer’s movement in the transverse plane on the forward movement was constructed.
Determination of Rolling Mill Roller Load during Procurement Transportation
Authors: Androsenko Mariya , Savelyeva Irina , Krayniy Ivan , Demidov Ivan , Deeva Irina
Published: July 2021

The paper shows how to calculate the loads on conveyor rollers at different positions of the conveyed billet. It also contains the diagrams of conveyors with different types of drives and loading diagrams as well.
Modelling episode of Saharan dust transfer over the Black Sea according to the WRF model and MODIS satellite data
Authors: Papkova Anna , Papkova Yulia , Shukalo Dmitrii
Published: July 2021

A high dust load from the Sahara Desert is recorded annually over the Black Sea region. To make a reliable forecast for the level of dust, many external factors such as the wind energy, the soil content in the moisture are to be considered. The physical characteristics of the aerosol particles in the atmosphere are also very important. This study focuses on the prediction of dust content for the Black Sea region by using the WRFdust model. Prolonged dust transport over the Black Sea was recorded during the period from September 25 to September 30, 2020. On these days, MODIS satellite images, return trajectories of AERONET and optical parameters of the atmosphere were analyzed.
Effect of Amino and Carboxyl Functionalization on the Photoluminescence Properties of Rice Husk-Derived Carbon Quantum Dots (RH-CQDs)
Authors: Hui Khee Chung , Zainal Abidin Nur Hafizah , Sambudi Nonni Soraya
Published: July 2021

In this work, carbon quantum dots (CQDs) are synthesized using rice husk as a natural precursor. The effect of amino and carboxyl functionalization is studied by adjusting the amount of ethylenediamine (EDA) as the amino source and ascorbic acid as the carboxyl source. HRTEM analysis show the formation of spherical carbon quantum dots. FTIR analysis confirms the presence of OH and CO bonding, indicating formation of CQDs. The addition of EDA and ascorbic acid quenches the fluorescence and shifts the emission wavelength from blue region (450-485 nm) to green region (500-565 nm). Based on the results, N-RHCQDs (0.6 ml) and C-RHCQDs (2.5ml) are chosen as the best samples as they give the highest quantum yield of 0.37% and 3.26% respectively. This implies that the fluorescence intensity is higher at a more basic and less acidic condition. This study suggests that the addition of different functionalization agents can tune the photoluminescence properties of CQDs that will be beneficial for its application.
Screening of gallate-based metal-organic frameworks for single-component CO2 and CH4 gas
Authors: Ismail Marhaina , Bustam Mohamad Azmi , Kari Nor Ernie Fatriyah
Published: July 2021

Adsorption using porous adsorbents is widely applied in carbon dioxide (CO2) capture due to its potential energy saving with low operating cost. Metal-organic frameworks (MOFs) are preferable over conventional adsorbents as MOFs have tunable structure properties. Organic linkers from phytochemical-based give a new idea in forming MOFs. Gallic acid is classified under phytochemicals can act as an alternative organic linker in a new family of hybrid framework materials due to low cost, low toxicity, easy availability and naturally abundant. Due to unique property of MOFs that can be tailored, screening using systematic tool is very important. Molecular modeling is proven to play a crucial role in providing an estimation on adsorption capacity, selectivity and adsorbent selection. Grand Canonical Monte Carlo (GCMC) method via Sorption module in Material Studio was performed to compute loading curves of CO2 and methane (CH4) in MOFs. Based on the simulation results, it shows that gallate-based MOFs can be a new promising adsorbent in CO2 capture as the predicted CO2 loading is significantly higher than CH4. The highest predicted CO2 adsorption capacity is achieved by Mg-gallate and the lowest is by Ag-gallate with 7.79 mmol/g and 6.35 mmol/g respectively. The applicability of gallic acid to act as an alternative linker is relevant for practical applications.
Influence of supercritical CO2 flowrate in one-pot supercritical fluid extraction of Carica papaya linn. leaves: A broken-intact-cell approach
Authors: Chai Yee Ho , Yusup Suzana , Seer Qiu Huan , Ruslan Muhammad Syafiq Hazwan , Chin Bridgid Lai Fui
Published: July 2021

The presence of rich phytochemicals in Carica papaya linn. leaves are potentially beneficial in pharmaceutical, nutraceutical and food industries. This work aims to investigate the roles of solvent flowrate for the predictive behaviour of supercritical fluid extraction of essential oil-rich extracts by broken-intact-cell modelling approach. Through kinetic model fitting of experimental data, the adjustable parameters namely G, φk, Z and Y were determined through error minimization procedure. From the cumulative extraction curve at solvent rate from 4 – 8 mL/min, the values of mass transfer coefficients were in the range of 4.40 × 10−5 m2/s – 19.92 × 10−5 m2/s with an overall relative 8.67% AARD. The grinding index and end of fast extraction time period was within the range of 0.144 – 0.258 and 30.38 – 91.17 min respectively. The role of solvent flowrate played an influential role in the extraction of papaya leaves extract.
Assessing the effects of operating parameters on flocculation of Chlorella vulgaris using bioflocculants extracted from miscellaneous waste biomass
Authors: Ng Zhi Min , Suparmaniam Uganeeswary , Lam Man Kee , Lim Jun Wei , Shuit Siew Hoong , Lim Steven , Chin Bridgid Lai Fui , Kiew Peck Loo
Published: July 2021

Harvesting of microalgae is one of the main challenges in the production of biodiesel due to the small cell size of microalgae cells. Chemical flocculants have been generally used in the harvesting of microalgae, but they are harmful to the environment and relatively costly. Therefore, the utilization of waste biomass in producing bioflocculants is the current research niche to introduce environmental-friendly harvesting method and to minimize the cost of biodiesel production. Thus, in the current work, flocculation Chlorella vulgaris using mild acid-extracted bioflocculants from miscellaneous waste biomass (cockle shell, peanut shell and banana peel) were conducted by varying the pH values, the dosage of bioflocculants and temperatures. Cockle shell bioflocculant demonstrated the best flocculation performance, with highest flocculation efficiency of 85.2% compared to the peanut shell bioflocculant with flocculation efficiency of 37% and banana peel bioflocculant with flocculation efficiency of 16.3%. The optimum flocculation conditions for cockle shell bioflocculant were determined as follow: pH 9, bioflocculant dosage of 140mg/L and temperature of 30oC. The findings herein presented practical applicability of bioflocculants extracted from cockle shell for safe, rapid and inexpensive microalgae harvesting.
Residual stress effects on fatigue crack propagation in Butt–Welded joints for 304 stainless steel sheets
Authors: El Shrief Eman , El-Megharbel Abla , El Domiaty Aly , Abd El-Hafez Hassan
Published: July 2021

Welded joints are sensitive to fatigue failure due to cyclic loading, as well as fatigue crack propagation influenced by the distribution of welding residual stress. In this study, the fatigue crack propagation rates in butt-welded joints for 304 stainless steel sheets were evaluated in the presence of welding residual stresses. The analysis consisted of two separate models: first, a 3D-finite element (FE) model was used to predict the residual stresses due to welding; second, a numerical study was undertaken to predict fatigue crack propagation in the presence and absence of residual stress using the extended finite element method (XFEM). The crack growth model (NASGRO) and available experimental data were applied to verify the simulation results. The XFEM without residual stress effects shows good agreement with the experimental data and the NASGRO model. However, in the presence of residual stress, the simulation results show less agreement with the NASGRO model. The level and the nature of residual stress have significant effects on crack growth. A faster crack propagation rate is recognized due to the effect of tensile residual stress at the crack tip, while a higher resistance to crack growth is developed due to a compressive residual stress field.
Stationäre psychiatrische Versorgung in der Corona-Krise durch Psychologen und Psychiater im Homeoffice und in der Klinik
Authors: Schaub Annette , Michel Clara , Beck Paula , Falkai Peter
Published: July 2021

Seit Auftreten der neuen Coronavirus (COVID-19) Pandemie im März 2020 erkrankten viele Menschen in Deutschland. Dies bedeutete eine Herausforderung für die Versorgung psychisch kranker stationärer Personen. Es kam zu einem sozialen Shut-down in Bayern mit Abnahme der sozialen Kontakte. Die vorliegende Studie beschäftigt sich mit der Umsetzung der stationären psychiatrischen Versorgung durch Psychologen und Psychiater im homeoffice und in der Klinik. Psychologen der Klinik für Psychiatrie und Psychotherapie der LMU München etablierten in der akuten Krise im homeoffice während der Quarantäne zusammen mit den in der Klinik tätigen Ärzten eine telefonische Patientenversorgung für stationäre Patienten, an der 23 Patienten mit depressiven und schizophrenen Störungen teilnahmen. Die Psychologen arbeiteten danach im stationären Setting mit 98 Teilnehmern. Die derzeitige Notlage und ihre Belastungen werden thematisiert und neue therapeutische Komponenten in die Versorgung integriert. Die Umsetzbarkeit von homeoffice, deren Möglichkeiten und Grenzen werden vorgestellt. Konzepte der stationären Patientenversorgung für Betroffene mit affektiven und schizophrenen Störungen sowie aktuelle Belastungsfaktoren und psychotherapeutische Konzepte werden thematisiert. Der aktuelle Ansatz wird von den Betroffenen und Ärzten positiv bewertet und bietet gute Möglichkeiten in der derzeitigen Situation. Mit Ausnahme der Patienten von der Akutstation konnten alle Patienten und selbst ältere von dieser Maßnahme profitieren. Während der Krise von März bis August arbeiteten alle Psychologen auf Ganztagsstellen mit der üblichen Behandlungsfrequenz von 1–2 Sitzungen die Woche, was insbesondere für ältere Personen von Bedeutung war. Während der akuten COVID-19 Krise pausierten lediglich stationsübergreifende Gruppen und Angehörigengruppen. Die Psychologen hatten wie die Ärzte und das Pflegepersonal eine systemrelevante Aufgabe.
Fallbericht: Kammerflimmern beim Jogging am Rheinufer: erfolgreiche Laienreanimation und Nachbesprechung (Outcome) nach 7 Monaten
Authors: Switalski Jörg , Lechleuthner Alex
Published: July 2021

Der vorliegende Fallbericht einer erfolgreichen Reanimation beruht auf der Durchführung
von suffizienten Maßnahmen der Wiederbelebung durch den Ehemann, als seine Frau beim
gemeinsamen Joggen einen Herz-Kreislauf-Stillstand aufgrund von Kammerflimmern erleidet. Es
erfolgt eine Nachbesprechung mit dem Ehepaar nach 7 Monaten.
New Phenolic Glycosides and Lignans from the Roots of Lilium dauricum
Authors: Xia Xiao , Zhang Jiao , Wang Xiao-Jiang , Lu Yan , Chen Dao-Feng
Published: July 2021

Three new phenolic glycosides, carvacrol-2-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (1), 1-methyl-3-isopropylphenol-4-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (2), p-methoxythymol-5-O-β-D-apiofuranosyl-(1 → 6)-β-D-glucopyranoside (3), and a pair of new 8-O-4′ neolignan enantiomers (5a/5b), together with 26 known compounds (4, 6 – 30) were isolated from the roots of Lilium dauricum. The structures of the new compounds were elucidated based on extensive spectroscopic and chemical methods, and the absolute configurations of 5a and 5b were established by electronic circular dichroism analysis. Nine compounds (1, 3, 4, 8, 9, 17, 25, 29, and 30) exhibited potent α-glucosidase inhibitory activity with IC50 values ranging from 73.4 µM to 988.2 µM. Besides, compound 19 displayed
strong anticomplementary activity (CH50: 71.6 µM).
When Benign Becomes Cancer: Malignant Degeneration of Chronic Inflammation
Authors: Conlon Christopher , Pupa Lauren , Reece Edward M. , Chu Carrie K. , Yu Jessie Z. , Vorstenbosch Joshua , Winocour Sebastian
Published: July 2021

Chronic inflammation, long implicated in the genesis of malignancy, is now understood to underlie an estimated 25% of all cancers. The most pertinent malignancies, to the plastic surgeon, associated with the degeneration of chronic inflammation include Marjolin's ulcer, breast implant-associated large cell lymphoma, radiation-induced sarcoma, and Kaposi's sarcoma. The cellular and genetic damage incurred by a prolonged inflammatory reaction is controlled by an increasingly understood cytokinetic system. Advances in understanding the chronic inflammatory cascade have yielded new therapeutics and therapeutic targets.
Preparedness for Pediatric COVID-19 Using Systems Approach: Experience of a Health Care Facility from India
Authors: Shenoy Rathika D. , Nayak Praveen , Jacob Ankeeta Menona , Rao Swathi Sunil , Hiremath Shivakumar
Published: July 2021

A pandemic leads to disruption and stretching of an existing health care system and its resources. Coronavirus disease 2019 (COVID-19) data show distinct and severe manifestations in children necessitating critical care. Children need prioritization as they are susceptible to COVID-19 as part of the family cluster, varied presentations, and mortality. The purpose of this report is to discuss the optimization of the health care system for pediatric care. The key initiatives were to identify our objectives, bring out changes to the organizational processes, and integrate the same into the existing system. A systems approach to health care delivery by optimizing infrastructure, human resources, materials, funding, leadership, and governance was undertaken. This resulted in creation of distinct COVID-19 and non-COVID-19 service areas, management protocols, and trained health care workers. Partnership was forged with the public health system. This preparedness and continued responses to the demands of the health care system helped us manage children ranging from neonates to adolescents efficiently. Though the health care system is mostly open, acting upon the modifiable factors gave better preparedness in a short time.
pH dependence of photochemical kinetics of thioxanthen-9-one from nanosecond time-resolved laser flash photolysis
Authors: Chen Lin , Li Yuan-ming , Zheng Min , Wei Xin , Wang Lin
Published: July 2021

pH dependent fluorescence emission of a thioxanthone-based probe has been reported recently. The potential determinant factors of pH dependence may provide important clues to design novel thioxanthone-based probes in the future. pH dependence of photochemical kinetics of thioxanthone itself was investigated in this work using nanosecond time-resolved laser flash photolysis. The nanosecond time-resolved transient absorption spectra and kinetics of TX in aqueous acetonitrile were recorded, as well as for a model reaction system including TX with diphenylamine (DPA) as a co-initiator. Besides the well-known absorption peak of 3TX*, other peaks at 417, 518, 673 and 780 nm, have been reliably attributed to major intermediates in the overall reaction between TX and DPA with photolysis, which has been confirmed to occur along a multistep process. In the strong acidic solution (pH≈3.0), TX and protonated TX ions (TXH+) coexist due to protonated equilibrium. Consequently, high proton concentration promotes the predominant decay pathway after photolysis from electron transfer to proton affinity. Subsequently, the different primary products, 3TXH+* or TX•−, proceed different secondary reaction channels. In addition, within the wide pH range from weak acid (pH=5.0) to alkaline solution (pH=13.0), the overall reaction mechanism and rates do not show visible changes.
Ultrafast decay dynamics of N-ethylpyrrole excited
to the S1 electronic state: A femtosecond time-resolved photoelectron
imaging study
Authors: Yuan Wen-peng , Feng Bai-hui , Yang Dong-yuan , Min Yan-jun , Yu Sheng-rui , Wu Guo-rong , Yang Xue-ming
Published: July 2021

N -ethylpyrrole is one of ethyl-substituted derivatives of pyrrole and its excited-state decay dynamics has never been explored. In this work, we investigate ultrafast decay dynamics of N - ethylpyrrole excited to the S1 electronic state using a femtosecond time-resolved photoelectron imaging method. Two pump wavelengths of 241.9 and 237.7 nm are employed. At 241.9 nm, three time constants, 5.0±0.7 ps, 66.4±15.6 ps and 1.3±0.1 ns, are derived. For 237.7 nm, two time constants of 2.1±0.1 ps and 13.1±1.2 ps are derived. We assign all these time constants to be associated with different vibrational states in the S1 state. The possible decay mechanisms of different S1 vibrational states are briefly discussed.
High-performance chemical information database towards accelerating discovery of metal-organic frameworks for gas adsorption with machine learning
Authors: Hao Zi-kai , Lv Hai-feng , Wang Da-yong , Wu Xiao-jun
Published: July 2021

Chemical structure searching based on databases and machine learning has attracted great attention recently for fast screening materials with target functionalities. To this end, we established a high-performance chemical structure database based on MYSQL engines, named MYDB. More than 160000 metal-organic frameworks (MOFs) have been collected and stored by using new retrieval algorithms for efficient searching and recommendation. The evaluations results show that MYDB could realize fast and efficient key-word searching against millions of records and provide real-time recommendations for similar structures. Combining machine learning method and materials database, we developed an adsorption model to determine the adsorption capacitor of metal-organic frameworks toward argon and hydrogen under certain conditions. We expect that MYDB together with the developed machine learning techniques could support large-scale, low-cost, and highly convenient structural research towards accelerating discovery of materials with target functionalities in the field of computational materials research.
Verification of mixing properties in two-dimensional shifts of finite type
Authors: Ban Jung-Chao , Hu Wen-Guei , Lin Song-Sun , Lin Yin-Heng
Published: July 2021

This work introduces constructive and systematic methods for verifying the topological mixing and strong specification (or strong irreducibility) of two-dimensional shifts of finite type. First, we define transition matrices on infinite strips of width n for all n ≥ 2. To determine the primitivity of the transition matrices, we introduce the connecting operators that reduce the high-order transition matrices to lower-order transition matrices. Then, two sufficient conditions for primitivity are provided; they are invariant diagonal cycles and primitive commutative cycles of connecting operators. Then, the primitivity, corner-extendability, and crisscross-extendability are used to demonstrate the topological mixing. Finally, we show that the hole-filling condition yields the strong specification property. The application of all the above-mentioned conditions can be verified in a finite number of steps.
Improving the short-term frequency stability of a magnetic-state-selected cesium beam clock with optical detection
Authors: Liu Chang , Chen Sifei , Chen Ziyu , Li Lingxiang , Xu Shaohang , Li Yining , Wang Jiale , Wang Yanhui , Hou Shimin , Zhang Jun , Dong Richang , Jiang Xiaobo
Published: July 2021

The microwave spectrum line shape and the signal-to-noise ratio of a compact optically detected magnetic-state-selection cesium beam clock are analyzed in this paper. As the noise analysis shows, the performance is related to the atomic utilization ratio and locking parameters when the laser frequency noise is the dominant noise source. Methods are adopted for realizing better short-term frequency stability of the clock, including using a highly efficient state-selection cesium beam tube, optimizing the locking parameters, and stabilizing the microwave power to maximize the error signal. After optimization, the signal-to-noise ratio of the clock reaches 7.0 × 103 in a bandwidth of 1 Hz and the clock demonstrates a short-term stability of 4.1 × 10−12 τ−1/2. The five-day Allan standard deviation reaches 7.7 × 10−15.
Gyrokinetic simulation of turbulence and transport in the SPARC tokamak
Authors: Howard N. T. , Rodriguez-Fernandez P. , Holland C. , Rice J. E. , Greenwald M. , Candy J. , Sciortino F.
Published: July 2021

The turbulence and transport expected in the SPARC tokamak Primary Reference Discharge (PRD) [P. Rodriguez-Fernandez et al., J. Plasma Phys. 86, 865860503 (2020)] have been investigated with the gyrokinetic code CGYRO [J. Candy et al., J. Comput. Phys. 324, 73–93 (2016)]. Linear and nonlinear simulations that focus on ion (kθρs<1.0) and electron-scale (kθρs>1.0) turbulence were used to probe the nature of the turbulence and the resulting transport in the fusion core. It is found that in the SPARC PRD, ion temperature gradient (ITG) turbulence is expected to dominate transport over most of the profile with some potential trapped electron mode impact in the near edge. Stiff turbulence is observed over a part of the plasma core such that SPARC's ion temperature profile will likely be pinned to just above the critical gradient for ITG. The role of electromagnetic turbulence, rotation, and electron-scale turbulence was investigated to provide some insight into the physics required to accurately predict SPARC performance via gyrokinetics. Additionally, predictions of impurity peaking for potential low- and high-Z SPARC first-wall materials are probed using ion-scale simulation. The dominance of low-k turbulence in SPARC provides a potential opportunity for more tractable prediction of plasma profiles using nonlinear gyrokinetics. This work is the first step toward full gyrokinetic profile prediction of SPARC kinetic profiles and the resulting fusion power and plasma gain.
Active feedback cooling of a SiN membrane resonator by electrostatic actuation
Authors: Borrielli A. , Bonaldi M. , Serra E. , Sarro P. M. , Morana B.
Published: July 2021

Feedback-based control techniques are useful tools in precision measurements as they allow us to actively shape the mechanical response of high quality factor oscillators used in force detection measurements. In this paper, we implement a feedback technique on a high-stress low-loss SiN membrane resonator, exploiting the charges trapped on the dielectric membrane. A properly delayed feedback force (dissipative feedback) enables the narrowing of the thermomechanical displacement variance in a similar manner to the cooling of the normal mechanical mode down to an effective temperature Teff. In the experiment reported here, we started from room temperature and gradually increasing the feedback gain, we were able to cool down the first normal mode of the resonator to a minimum temperature of about 124mK. This limit is imposed by our experimental setup and, in particular, by the injection of the read-out noise into the feedback. We discuss the implementation details and possible improvements to the technique.
Estimate of pre-thermal quench non-thermal electron density profile during Ar pellet shutdowns of low-density target plasmas in DIII-D
Authors: Hollmann E. M. , Austin M. , Bykov I. , Eidietis N. W. , Embreus O. , Herfindal J. L. , Hoppe M. , Lvovskiy A. , Parks P. B. , Paz-Soldan C. , Shiraki D. , Svenningsson I.
Published: July 2021

The radial density profile of pre-thermal quench (pre-TQ) early-time non-thermal (hot) electrons is estimated by combining electron cyclotron emission and soft x-ray data during the rapid shutdown of low-density (ne≲1019 m−3) DIII-D target plasmas with cryogenic argon pellet injection. This technique is mostly limited in these experiments to the pre-TQ phase and quickly loses validity during the TQ. Two different cases are studied: a high (10 keV) temperature target and a low (4 keV) temperature target. The results indicate that early-time, low-energy (∼10 keV) hot electrons form ahead of the argon pellet as it enters the plasma, affecting the pellet ablation rate; it is hypothesized that this may be caused by rapid cross field transport of argon ions ahead of the pellet or by rapid cross field transport of hot electrons. Fokker–Planck modeling of the two shots suggests that the hot electron current is quite significant during the pre-TQ phase (up to 50% of the total current). Comparison between modeled pre-TQ hot electron current and post-TQ hot electron current inferred from avalanche theory suggests that hot electron current increases during the high-temperature target TQ but decreases during the low-temperature target TQ. The uncertainties in this estimate are large; however, if true, this suggests that TQ radial loss of hot electron current could be larger than previously estimated in DIII-D.
Thermodynamic properties of the finite-temperature electron gas by the fermionic path integral Monte Carlo method
Authors: Filinov V. S. , Levashov P. R. , Larkin A. S.
Published: July 2021

The recently developed quantum path integral Monte Carlo approach [Filinov et al., Phys. Rev. E 102(3), 033203 (2020)] has been applied for the entropy difference calculations for the strongly coupled degenerated uniform electron gas (UEG), a well-known model of simple metals. The used approach includes the Coulomb and exchange interaction of fermions in the basic Monte Carlo cell and its periodic images as well as the change of variables in the path integral measure and exchange determinant. Calculations have been carried out at finite temperature in the canonical ensemble. Presented results include the pair distribution functions, the isochors, and isotherms of pressure, internal energy, and the entropy change in the strongly coupled and degenerate UEG. The obtained data may be useful for density functional theory.
Chirping modes in hybrid tokamak discharges
Authors: Marchenko V. S. , Reznik S. N.
Published: July 2021

In the so-called “hybrid” shots characterized by shear-free core with safety factor slightly above 1, an interesting yet unexplained chirping activity has been observed in tokamaks with a high fast ion content. Namely, fishbone modes with m=n=1 and downward frequency chirping are accompanied by frequency jumps of the tearing modes with m=n+1 and n > 1 [here m(n) is the poloidal (toroidal) mode number]. In the present work, these related phenomena are attributed to a combination of the two impulsive toroidal torques: (1) recoil torque applied to the shear-free core during fishbone burst and (2) electromagnetic torque applied to the tearing layer. We have developed a quasi-linear model in which fast transients of the plasma toroidal rotation induced by these torques qualitatively reproduce the observed chirping dynamics.
Re-cyclic photophysics in perovskite Cs4PbBr6
Authors: Bae Hyeongyu , Park Dongcheol , Lee Eunsang , Lee Hohjai , Lee Kang Taek
Published: July 2021

Most photophysical studies in the halide perovskite have focused on the characteristics of the surface. However, the photons generated at the surface would be absorbed by the same material (re-absorption), and the photophysics of re-absorbed photons are rarely studied. Herein, we present our recent observation of the re-emission (photoluminescence after re-absorption, IR) in Cs4PbBr6, which is temporally slower than the surface-emission (IS). We performed a characterization of Cs4PbBr6, a power dependence experiment, and a lifetime measurement to reveal the emitting properties of Cs4PbBr6. However, we characterized the first re-emission (re-emission after first re-absorption, IFR) of Cs4PbBr6. The analysis of IFR revealed that the energy intervals between IS and IFR and between IFR and final re-emission (IR) are close to integer multiples. Therefore, we suggested that the least number of repeated re-absorptions required for generating IR is three.
Capturing and recording cold chain temperature violations through parametric alarm-sensor tags
Authors: Hussein Hussein M. E. , Rinaldi Matteo , Onabajo Marvin , Cassella Cristian
Published: July 2021

While the Internet-of-Things has already fueled a plethora of different possibilities, we are still in need of means to mitigate the inefficiencies of the cold chain generating every year massive food and drug waste, even causing serious illnesses. This is caused by the lack of remote sensing technologies suitable for a widespread deployment able to timely mark any cooled items exposed to inadequate temperatures. This work introduces a class of printable, battery-less, and chip-less passive tags, namely, the Parametric Alarm Sensor Tags (PASTs), allowing detection of any violations in the storage temperature of refrigerated items with extraordinary reading ranges. In order to do so, PASTs leverage a three-way sensing scheme and nonlinear dynamics never explored in any tag technologies to trigger the passive generation of a radio frequency signal only when the temperature exceeds a remotely configurable threshold (Tth). Furthermore, PASTs exhibit a dynamically enabled temperature-controlled hysteresis loop. As a result, the signal generated at the occurrence of a temperature violation remains active even if the temperature returns within a tolerable range. This allows us to flag any items previously or currently exposed to inadequate temperatures, allowing their prompt identification. We report a 870 MHz PAST and show that, thanks to its unique characteristics, it is finally possible to identify any items along the cold chain whose temperature has exceeded a remotely configurable Tth value as low as −47 °C, even if operating in uncontrolled electromagnetic environments and up to 46 m away from the corresponding PAST outside a line-of-sight.
Continuously graded doped semiconducting polymers enhance thermoelectric cooling
Authors: Ma Tengzhou , Kent William , Dong Ban Xuan , Grocke Garrett L. , Patel Shrayesh N.
Published: July 2021

Spatial control of thermoelectric (TE) material properties through functional grading is a promising strategy in improving cooling performance. Notably, studies on organic-based functionally graded materials for thermoelectrics have been limited compared to their inorganic-based counterparts. In this Letter, we demonstrate how the inherent processability of semiconducting polymers coupled with molecular doping provides a facile approach in fabricating continuously graded (CG) thin films beneficial for thermoelectric (Peltier) cooling. We achieve CG thin films with 1D profiles in conductivity (σ) and Seebeck coefficient (α) through spatial compositional control of the molecular p-dopant 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane in semiconducting poly[2,5-bis(3-tetradecylthiophen-2-yl) thieno [3,2-b]thiophene]. Using the experimentally derived σ and α spatial profiles, linear constitutive relations coupled with conservation of charge and energy are used to model the cooling performance of the CG thin films. In comparison to their equivalent uniform conditions, the CG thin films yield higher cooling temperature (ΔTc = TH − Tc) and higher coefficient of performance. The enhanced performance arises from efficient redistribution of the Joule heating and Peltier cooling effects. Moreover, the model calculations reveal that the magnitude of the σ profile and the slope of the α profile are specific attributes leading to the enhanced cooling in CG thin films. Overall, this study highlights a simple yet powerful strategy to improve the cooling performance of thermoelectric materials through functionally graded doped semiconducting polymers.
Controlled syngas production by electrocatalytic CO2 reduction on formulated Au25(SR)18 and PtAu24(SR)18 nanoclusters
Authors: Choi Woojun , Seong Hoeun , Efremov Vladimir , Lee Yongjin , Im Sanghyeok , Lim Dong-Hee , Yoo Jong Suk , Lee Dongil
Published: July 2021

Syngas, a gaseous mixture of CO and H2, is a critical industrial feedstock for producing bulk chemicals and synthetic fuels, and its production via direct CO2 electroreduction in aqueous media constitutes an important step toward carbon-negative technologies. Herein, we report controlled syngas production with various H2/CO ratios via the electrochemical CO2 reduction reaction (CO2RR) on specifically formulated Au25 and PtAu24 nanoclusters (NCs) with core-atom-controlled selectivities. While CO was predominantly produced from the CO2RR on the Au NCs, H2 production was favored on the PtAu24 NCs. Density functional theory calculations of the free energy profiles for the CO2RR and hydrogen evolution reaction (HER) indicated that the reaction energy for the conversion of CO2 to CO was much lower than that for the HER on the Au25 NC. In contrast, the energy profiles calculated for the HER indicated that the PtAu24 NCs have nearly thermoneutral binding properties; thus, H2 production is favored over CO formation. Based on the distinctly different catalytic selectivities of Au25 and PtAu24 NCs, controlled syngas production with H2/CO ratios of 1 to 4 was demonstrated at a constant applied potential by simply mixing the Au25 and PtAu24 NCs based on their intrinsic catalytic activities for the production of CO and H2.
Perspective—On the thermodynamics of perfect unconditional security
Authors: Chamon Christiana , Kish Laszlo B.
Published: July 2021

A secure key distribution (exchange) scheme is unconditionally secure if it is unbreakable against arbitrary technological improvements of computing power and/or any development of new algorithms. There are only two families of experimentally realized and tested unconditionally secure key distribution technologies: quantum key distribution (QKD), the base of quantum cryptography, which utilizes quantum physical photonic features, and the Kirchhoff-Law–Johnson-Noise (KLJN) system that is based on classical statistical physics (fluctuation–dissipation theorem). The focus topic of this paper is the thermodynamical situation of the KLJN system. In all the original works, the proposed KLJN schemes required thermal equilibrium between the devices of the communicating parties to achieve perfect security. However, Vadai et al., in (Nature) Sci. Rep. 5, 13653 (2015) show a modified scheme, where there is a non-zero thermal noise energy flow between the parties, yet the system seems to resist all the known attack types. We introduce an attack type against their system. The attack utilizes coincidence events between the line current and voltages. We show that there is a non-zero information leak toward the Eavesdropper, even under idealized conditions. As soon as the thermal equilibrium is restored, the system becomes perfectly secure again. In conclusion, perfect unconditional security requires thermal equilibrium.
Prednisolone rescues Duchenne muscular dystrophy phenotypes in human pluripotent stem cell–derived skeletal muscle in vitro
Authors: Al Tanoury Ziad , Zimmerman John F. , Rao Jyoti , Sieiro Daniel , McNamara Harold M. , Cherrier Thomas , Rodríguez-delaRosa Alejandra , Hick-Colin Aurore , Bousson Fanny , Fugier-Schmucker Charlotte , Marchiano Fabio , Habermann Bianca , Chal Jérome , Nesmith Alexander P. , Gapon Svetlana , Wagner Erica , Gupta Vandana A. , Bassel-Duby Rhonda , Olson Eric N. , Cohen Adam E. , Parker Kevin Kit , Pourquié Olivier
Published: July 2021

Significance

Duchenne muscular dystrophy (DMD) is a devastating disease caused by mutation in the X-linked dystrophin gene, resulting in skeletal muscle loss and patient premature death. Here, we present an improved protocol for the differentiation of human pluripotent stem cells to the skeletal muscle lineage. Using this protocol for the differentiation of human isogenic-induced pluripotent stem cells lacking the DMD gene, we can reproduce several features of the pathology including mislocalization of proteins of the dystrophin-associated complex, increased fiber branching, contraction defects, and calcium signaling hyperactivity. Several of these defects can be rescued in part in vitro by treating cells with prednisolone, the standard of care for DMD patients, supporting direct action of this drug on the diseased fibers.
Observing the subglacial hydrology network and its dynamics with a dense seismic array
Authors: Nanni Ugo , Gimbert Florent , Roux Philippe , Lecointre Albanne
Published: July 2021

Significance

Our understanding of when, where, and under which conditions subglacial water flow favors or impedes glacier flow remains uncertain mainly because of sparse field observations. This strongly limits our capability to assess the susceptibility of glaciers and ice sheets to a future increase in meltwater input due to climate warming. Here, we overcome classic observational difficulties by establishing an innovative seismic-based approach. From dense seismic array observations, we retrieve with unprecedented detail the two-dimensional map of a subglacial hydrology network. We observe its day-to-day evolution from a cavity-like system that favors glacier flow to a channel-like system that impedes glacier flow. Our method is easily adaptable and readily applicable to other settings than alpine glaciers such as Greenland or Antarctica.
Sufu negatively regulates both initiations of centrosome duplication and DNA replication
Authors: Zhuang Tenghan , Zhang Boyan , Song Yihong , Huang Fan , Chi Wangfei , Xin Guangwei , Zhang Ziyu , Cheng Steven Y. , Jiang Qing , Zhang Chuanmao
Published: July 2021

Significance

The initiations of both DNA replication and centrosome duplication are strictly coordinated during the cell cycle, and failure to do so will damage the cell or induce centrosome amplification and genome instability. Here, we report that Sufu inhibits centrosome duplication via facilitating CP110 phosphorylation and suppresses DNA replication via promoting intranuclear Cdt1 degradation and expelling prereplication complex (pre-RC) components from chromosomes. Elimination of inhibitory Sufu from the centrosome counts on vesicle release at the ciliary tip, and, from the nucleus, it relies on protein degradation. This work reveals a mechanism through which Sufu, which acts as a “master switch,” negatively regulates both initiations of DNA replication and centrosome duplication, and it may shed light on the preparation step control of cell proliferation.
Proton-gated coincidence detection is a common feature of GPCR signaling
Authors: Kapolka Nicholas J. , Rowe Jacob B. , Taghon Geoffrey J. , Morgan William M. , O’Shea Corin R. , Isom Daniel G.
Published: July 2021

Significance

In complex biological systems, cells are constantly exposed to multiple physical and chemical stimuli. To decode such diverse inputs, cells use proteins embedded in the membrane to distinguish signal from noise and mount appropriate cellular responses. G protein-coupled receptors (GPCRs) represent the largest family of cell surface receptors in humans with more than 800 unique members. Here, we show that many GPCRs function as molecular coincidence detectors that couple proton (H
+
) binding to receptor agonism. Our findings provide insights into the fundamentals of GPCR signaling and avenues for exploring GPCR responses to coincident H
+
signals generated by a variety of biological processes and pathological scenarios.