bluuebunny/crossref_metadata_2025 huggingface dataset:
A hybrid methodology for distribution level photovoltaic power production forecasting verified at the distribution system of Cyprus
Authors: Theocharides Spyros , Spanias Chrysovalantis , Papageorgiou Ioannis , Makrides George , Stavrinos Stavros , Efthymiou Venizelos , Georghiou George E.
Published: September 2021

Accurate photovoltaic (PV) power forecasting is an essential tool that enables the efficient integration of solar electricity and energy trading. This work proposes a novel methodology for the implementation of a forecasting tool that provides aggregated PV production day‐ahead forecasts for the PV systems installed at a distribution level. Specifically, the tool is a cloud‐based platform, comprising of a data quality block, a weather forecasting model, a machine learning power prediction step and an up‐scaling aggregation stage. In this context and in the absence of a fully observable distribution system, the aggregated PV generation was estimated using a clustering approach and up‐scaling the measured generation of reference systems to the aggregated installed capacity. The results demonstrated that the implemented tool exhibited high forecasting accuracies, lower than 10% given by the mean absolute percentage error when applied to the distribution system of Cyprus. Furthermore, the comparative benchmarking of the up‐scaling techniques against the estimated aggregated PV generation demonstrated that the best‐performing approach was the hybrid model, which provided a normalised root mean square error of 10.29% and mean absolute percentage error of 9.11%. Finally, useful information is provided for establishing a robust day‐ahead forecasting methodology that is based on an optimal supervised learning and hybrid up‐scaling approach.
Image semantic segmentation method based on GAN network and FCN model
Authors: Zhao Lixin
Published: September 2021

In order to improve the accuracy of image semantic segmentation, an image semantic segmentation method based on generative adversarial network (GAN) and fully convolutional network (FCN) model is proposed. First of all, the network structure of the generator is improved. Introducing the residual module in the convolutional layer for difference learning makes the network structure sensitive to changes in the output, so as to better adjust the weight of the generator. Second in order to reduce the number of parameters and calculations, a small convolution kernel is used to halve the number of channels of the input feature map before using the large convolution kernel. Finally, the output of the convolutional layer and the output of the deconvolutional layer are connected by using the idea of a U‐shaped network to avoid low‐level information sharing. The proposed method was experimentally demonstrated on the PASCAL VOC 2012 and CamVid datasets. Experimental results show that the proposed method effectively improves the accuracy of image segmentation, and avoids inaccurate detection caused by insufficient image pixel information and noise interference. Its mean pixel accuracy (MPA) and mean intersection over union (MIOU) are higher than other comparison methods.
Adaptive restoration of pedestrian appearance in the spatiotemporal domain
Authors: Zhang Yunzuo , Guo Yaning , Zhang Jiayu
Published: September 2021

Video synopsis based on visual rhythm has a small amount of calculation and strong representativeness, but the drawback is that the spatiotemporal pedestrians are distorted and illegible due to the loss of their own unique spatial morphology information, which leads to poor performance of video synopsis. To solve this problem, this letter proposed an adaptive restoration method of pedestrian appearance in the spatiotemporal domain. First, a single‐pixel row is taken as the sampling unit to complete the horizontal visual rhythm stitching; second, the relationship between the pedestrian spatiotemporal trajectory slope in the horizontal visual rhythm and the pedestrian movement speed is deduced; finally, the spatiotemporal trajectory slope is used as the basis for the vertical visual rhythm sampling width, and the adaptive restoration of pedestrian appearance in the spatiotemporal domain is completed. Experimental results show that the contour fluency and visual perception effect of pedestrian appearance restored by the proposed method are better, and the difference ratio of the proposed method is 0.08566, and the average running time is 421.0760 s, which has obvious advantages over the comparison method.
Beyond the dips of V807 Tau, a spectropolarimetric study of a dipper’s magnetosphere
Authors: Pouilly K. , Bouvier J. , Alecian E. , Alencar S. H. P. , Cody A.-M. , Donati J.-F. , Grankin K. , Rebull L. , Folsom C. P.
Published: September 2021

Context. The so-called dippers are pre-main-sequence objects that accrete material from their circumstellar disks through the stellar magnetosphere. Their unique type of variability allows us to probe the magnetic star-disk interaction processes in young stellar objects.

Aims. We aim to characterize the magnetospheric accretion process in the young stellar object V807 Tau, one of the most stable dippers revealed by K2 in the Taurus star forming region.

Methods. We performed photometric and spectropolarimetric follow-up observations of this system with CFHT/ESPaDOnS in order to investigate the variability of the system over several rotational periods.

Results. We derive a 4.38 day period from the K2 dipper light curve. This period is also seen in the radial velocity variations, which we ascribe to spot modulation. The slightly redshifted narrow component of the He I 5876 Å line as well as the high velocity red wing of the Hβ and Hγ emission line profiles also vary in intensity with the same periodicity. The former traces the accretion shock at the stellar surface, and the latter is a signature of an accretion funnel flow crossing the line of sight. We derive a surface brightness map and the topology of the surface magnetic field from the modeling of Stokes I and V profiles, respectively, for photospheric lines and for the He I emission line. The latter reveals a bright spot at the stellar surface, located at a latitude of 60°, and a maximum field strength of ∼2 kG at this location. The topology of the magnetic field at the stellar surface is dominated by a dipolar component inclined by about 40° onto the spin axis. Variable blueshifted absorption components seen in the Balmer line profiles suggest episodic outflows. Despite of its clear and stable dipper behavior, we derive a relatively low inclination of 40° to 50° for this system, which calls question the origin of the dips. The low inclination we infer is also consistent with the absence of deep inverse P Cygni components in the line profiles.

Conclusions. We conclude that magnetospheric accretion is ongoing in V807 Tau, taking place through non-axisymmetric accretion funnel flows controlled by a strong, tilted, and mainly dipolar magnetic topology. Whether an inner disk warp resulting from this process can account for the dipper character of this source remains to be seen, given the low inclination of the system.
Redshift identification of X-ray-selected active galactic nuclei in the J1030 field: searching for large-scale structures and high-redshift sources
Authors: Marchesi S. , Mignoli M. , Gilli R. , Peca A. , Bolzonella M. , Nanni R. , Annunziatella M. , Balmaverde B. , Brusa M. , Calura F. , Cassarà L. P. , Chiaberge M. , Comastri A. , Cusano F. , D’Amato Q. , Iwasawa K. , Lanzuisi G. , Marchesini D. , Morishita T. , Prandoni I. , Rossi A. , Tozzi P. , Vignali C. , Vito F. , Zamorani G. , Norman C.
Published: September 2021

We publicly release the spectroscopic and photometric redshift catalog of the sources detected withChandrain the field of thez= 6.3 quasar SDSS J1030+0525. This is currently the fifth-deepest extragalactic X-ray field, and reaches a 0.5–2 keV flux limit off0.5 − 2= 6 × 10−17erg s−1cm−2. Using two independent methods, we measure a photometric redshift for 243 objects, while 123 (51%) sources also have a spectroscopic redshift, 110 of which come from an INAF-Large Binocular Telescope (LBT) Strategic Program. We use the spectroscopic redshifts to determine the quality of the photometric ones, and find it to be in agreement with that of other X-ray surveys which used a similar number of photometric data points. In particular, we measure a sample normalized median absolute deviation ofσNMAD= 1.48 × median(||zphot − zspec||/(1 +zspec)) = 0.065. We use these new spectroscopic and photometric redshifts to study the properties of theChandraJ1030 field. We observe several peaks in our spectroscopic redshift distribution betweenz= 0.15 andz= 1.5, and find that the sources in each peak are often distributed across the wholeChandrafield of view. This confirms that X-ray-selected AGNs can efficiently track large-scale structures over physical scales of several megaparsecs. Finally, we computed theChandraJ1030z> 3 number counts: while the spectroscopic completeness of our sample is limited at high redshift, our results point towards a potential source excess atz ≥ 4, which we plan to either confirm or reject in the near future with dedicated spectroscopic campaigns.
Socio-economic benefit of rubber agroforestry system for improved livelihood in Edo State, Nigeria
Authors: Okwu-Abolo C. , Soaga J.A. , Idoko S.O.
Published: September 2021

Rubber Agroforestry System (RAS) is an innovative farming system contributing significantly to the livelihood of smallholders in Edo State. Data for this study were collected from 120 rubber smallholder farmers having a contiguous 2 hectares farmland with the aid of structured questionnaire using multistage sampling technique with a 3-stage design. Data collected were analyzed using descriptive, inferential, and budgetary analysis. The result revealed that majority of the RAS farmers were males, with an average mean age of 49 years and most of the RAS farmers had some level of education, they attained secondary and tertiary education with an average number of 8.3 years in education. Furthermore, the total annual revenue earned by the respondents was ₦992,500 ($ 2,756.94) with a mean annual net income of ₦527,003 ($ 1,463.90) while the return per naira invested was ₦1.69. This shows that for every ₦1 invested in the cropping combination in the RAS, there was a return of 69 kobo in the study area. Thus, RAS provides income and employment for smallholder community to be self-sufficient and economically independent. This study concludes that respondents valued RAS as an innovative sustainable agroforestry system capable of generating income and employment. Government therefore should leverage through adequate fiscal policy to enable easy credit facility by farmers
Ecosystem Services of Indigenous Kaliwu Agroforestry System in Sumba, Indonesia
Authors: Njurumana Gerson N. , Sadono Ronggo , Marsono Djoko , Irham
Published: September 2021

Agroforestry is an environmentally friendly land resource management applied by farmers in various countries. The differences in ethnicity, geography, biophysical environment, and socio-economic background influence the application of this agricultural model, known as indigenous agroforestry. However, information on the management and ecosystem services of indigenous agroforestry in semi-arid ecosystems is not widely known. This research examined the management and provision of service for the Indigenous Kaliwu Agroforestry System (IKAS) on Sumba island. It was carried out in the Central Sumba regency using survey and observation methods in 70 sample units of farmer households distributed in 7 villages. Data were collected through interviews and observations on IKAS management initiatives, including provision services for foodstuff, fuelwood, timbers, and fodders. The results showed that IKAS is a local initiative model for the management of flora biodiversity through the replication of natural forest models in traditional cultivation environments. This is reflected by the plant’s biodiversity developed at IKAS, including endemic and cultural keystone species. The development of various plant species has implications for the provision services for foodstuff in form of tubers and fruits, fuelwood, timbers, and fodder. In addition, IKAS plays a role in supporting sustainable dryland management, biodiversity conservation, and farmers’ livelihoods. This research recommends that the optimization of the IKAS role for community livelihoods and environmental conservation be carried out through the support of its development policies by local government in Sumba.
Variations of Soil Properties on Post Shifting Cultivation area in Primary Forest
Authors: Nufus Malihatun , Budiadi  , Widiyatno
Published: September 2021

Shifting cultivation in tropical forest was presumed as the major cause of soil degradation and soil nutrient depletion, and need several years--namely forest-fallow periods-- to be recovered. Soil properties dynamic monitoring has been done in the tropical forest in Central Kalimantan at one, five and ten year after abandonment, and compared to primary forest, to predict the time for soil recovery in term of Calcium (Ca), Magnesium (Mg), Potassium (K), Natrium (Na) content and cation exchange capacity (CEC). The soil properties status can be beneficial for rehabilitation activities through practicing agroforestry by the forest dwellers. The results showed that soil properties (i.e. Ca, Mg, K, CEC) were significantly different among soil depth (P<0.05), but not for Na. Highest value of Ca, Mg, K and Na were observed in the soil surface (0-20 cm), Soil nutrient contents were significantly changed with the time of abandonment, the highest value of CEC, Ca, K, and pH were found in five years after the abandonment. It suggested that soil nutrients were distributed in the soil surface composed from litter of pioneer trees. The research suggested that soil recovery was probably occurred during early fallows, and agroforestry can be practiced at five year after the abandonment.
Understory and Soil Macrofauna Diversity under the Three Young Native Species andAcacia crassicarpain a Drained Peatland of Pelalawan-Riau, Indonesia
Authors: Pribadi Avry , Junaedi Ahmad
Published: September 2021

Most studies mentioned thatAcacia crassicarpabelongs to invasive species that could threat the native biodiversity. To respond that issue, we conducted a study that covers the understory and soil macrofauna diversity of three native tree species, namely mahang (Macaranga pruinosa), skubung (Macaranga gigantea) and geronggang (Cratoxylum arborescens) and an exotic species namely krassikarpa in a drained peatland in Pelalawan, Riau. The observation of understory vegetation under each studied species was undertaken by using 2 x 1 m plots. Furthermore, the structure of macrofauna was observed by pitfall trap methods. Results revealed that there were two fern species namelyNeprolephis biserrataandStenochlaena palustristhat dominated the understory vegetation in namely mahang (Macaranga pruinosa), skubung (Macaranga gigantea) and geronggang (Cratoxylum arborescens). The diversity index in vegetation structure among those four tree species was insignificantly varied. Moreover, the percentage of understory coverage underA. crassicarpawas significantly higher than that under all native tree species. On the other hand, Formicidae and Rhinotermitidae were dominant in skubung and krassikarpa. Meanwhile, Formicidae and Blattidae were high in mahang and geronggang. Furthermore, diversity index of macrofauna were significantly low at krassikarpas`s understory compare to other three native species. This study suggested that the introduction of krassikarpa affect the biodiversity.
Contribution of Agroforestry Plants to Farmers’ Income in Nglanggeran Agricultural Technology Park
Authors: Adhi Saputro Wahyu , Purnomo Singgih , Rahmawati Ika
Published: September 2021

Agroforestry cultivation is very often practiced in Indonesia. In particular, combining cocoa plantations with several other types of plants such as woody plants, bananas and other plants. This is also done by farmers in the Nglanggeran Agricultural Technology Park. Cultivating agroforestry crops has many advantages, one of which is increasing profits. This study aims to determine the composition of agroforestry patterned crops that provide the highest income and welfare levels for farmers. This research uses analytical descriptive method. The sample used is 60 farmers who cultivate the main crop of cocoa in Nglanggeran Village. Based on the research results, it can be seen that type 6 criteria provides more benefits by combining cocoa with Mahogany, sengon, guava crystals, and durian plants. These criteria have an Average income / household / year of IDR 18,120,430. The highest contribution is in Criterion IV, followed by Criterion VI, then followed by Criteria I, II, V and III. The highest contribution is criterion 4 with a contribution to farmers’ income of 60.32%.
Delayed gamma fraction determination in the zero power reactor CROCUS
Authors: Pakari Oskari , Mager Tom , Lamirand Vincent , Frajtag Pavel , Pautz Andreas
Published: September 2021

Gamma rays are an inextricable part of a nuclear reactor’s radiation field, and as such require characterization for dose rate estimations required for the radiation protection of personnel, material choices, and the design of nuclear facilities. Most commonplace radiation transport codes used for shielding calculations only included the prompt neutron induced component of the emitted gamma rays. The relative amount of gamma rays that are emitted from delayed processes – the delayed gamma fraction – amount to a significant contribution, e.g. in a typical zero power reactor at steady state is estimated to be roughly a third. Accurate predictions of gamma fields thus require an estimation of the delayed content in order to meaningfully contribute. As a consequence, recent code developments also include delayed gamma sources and require validation data. The CROCUS zero power research reactor at EPFL is part of the NEA IRPhE and has therefore been characterized for benchmark quality experiments. In order to provide the means for delayed gamma validation, a dedicated experimental campaign was conducted in the CROCUS reactor using its newly developed gamma detection capabilities based on scintillators. In this paper we present the experimental determination of the delayed gamma fraction in CROCUS using in-core neutron and gamma detectors in a benchmark reactor configuration. A consistent and flexibly applicable methodology on how to estimate the delayed gamma fraction in zero power reactors has hitherto not existed – we herein present a general experimental setup and analysis technique that can be applied to other facilities. We found that the build-up time of relevant short lived delayed gamma emitters is likely attributed to the activation of the aluminium cladding of the fuel. Using a CeBr3scintillator in the control rod position of the CROCUS core, we determined a delayed gamma fraction of (30.6±0.6)%.
Exploration of high-altitude dynamic soaring based on six-degree-of-freedom model
Authors: Liu Siqi , Bai Junqiang
Published: September 2021

Dynamic soaring is an emerging flight range-extension technology that effectively reduces UAV's energy consumption by deriving wind energy from lateral gradient wind fields. Comparing with the small UAV's near the surface, the application of dynamic soaring technology in the high-altitude long-endurance flight requires the additional consideration of the influence of sustained side wind, the influence of the sideslip angle cannot be ignored. This puts higher requirements on the flight dynamics model. In this paper, the dynamic model for the high-altitude dynamic soaring based on the six-degree-of-freedom equation is modeled to replace the traditional mass point model; the energy change principle of the high-altitude dynamic gliding is derived; the effect of the high-altitude wind field on the dynamic soaring UAV is analyzed; and the way to get optimal wind field energy acquisition and energy saving efficiency are analyzed. The results show that the dynamics model based on the six-degree-of-freedom equation can more realistically reflect at high altitude; the application of dynamic soaring can effectively improve the range of the high-altitude UAV; the wind direction at high-altitude wind field has a significant effect on the dynamic soaring efficiency.
Optimization of secondary source configuration in enclosure using plane wave decomposition
Authors: Xu Jian , Chen Kean , Wang Lei , Zhang Yazhou
Published: September 2021

The optimization of secondary source configuration for an active noise control (ANC) system in its enclosed space generally focuses on noise reduction requirements at discrete points only. This may lead to the poor noise reduction performance in the whole spatial region, and it is necessary to know the information on error sensor positions in advance. To address this problem, a cost function for spatial-region-oriented noise reduction is proposed. The plane wave decomposition of the enclosed sound field is used to obtain the primary field plane waves and the unit secondary field plane wave of each candidate secondary source as the prior knowledge for configuration optimization, so as to formulate a wave-domain ANC cost function. The optimization method adopts the simulated annealing search. Taking a rigid-walled rectangular cavity as an example, the optimization method is firstly compared with two space-domain methods by using analytic values of the wave-domain prior knowledge. The comparison results show that the better reduction of spatial acoustic potential energy can be achieved independent of the error sensor configuration information. Then the estimated values of the wave-domain prior knowledge through measuring randomly distributed microphones are used to optimize the configuration of the ANC system. The optimization results suggest that the noise reduction of spatial acoustic potential energy of the optimized configuration can be better than that of the space-domain method, but the microphone positions have a great influence on the noise reduction performance.
Neurofeedback in der Suchtrehabilitation
Authors: Hässelbarth Farid
Published: September 2021

Mithilfe des Neurofeedbacks sollen suchterkrankte Patienten lernen, ihre Wahrnehmung zu steuern und ihr Verhalten zu verändern. Unser Autor – selbst Pflegender – beschreibt, welche Erfahrungen er bei der Behandlung seiner Patienten mit Neurofeedback gemacht hat und ob es sich als ergänzende Methode in der Suchttherapie eignet.
Speech Characteristics of Patients with Parkinson's Disease—Does Dopaminergic Medications Have a Role?
Authors: Vandana Valiyaparambath Purushothaman , Darshini Jeevendra Kumar , Vikram Venkappayah Holla , Nitish Kamble , Pal Pramod Kumar , Ravi Yadav
Published: September 2021

Objective The present study aimed to investigate the effects of dopaminergic medication on voice, speech motor functions, and motor impairment in patients with Parkinson's disease (PD).

Materials and Methods Twenty-five individuals (16 males and 9 females) with PD underwent comprehensive assessment of voice, speech, and motor functions in levodopa medication ON and medication OFF conditions. Age- and gender-matched healthy controls were recruited to compare speech and acoustic parameters. Multi-Dimensional Voice Program (MDVP) from Computerized Speech Laboratory (Model: 4500) was utilized for acoustic analysis of voice and the Voice Handicap Index (VHI) for the self-assessment of vocal function. Frenchay Dysarthria Assessment (FDA-2) and Unified Parkinson's Disease Rating Scale-III (UPDRS III) were used to evaluate speech motor and motor functions, respectively.

Statistical Analysis The mean and standard deviation were used as descriptive statistics measures. Raw scores were obtained for FDA-2, DRS, VHI, MDVP parameters, and UPDRS-III in either medication condition. The Wilcoxon signed-rank test was performed to determine the statistical significance of the above measures in both genders across the medication conditions. Spearman's rank correlation coefficient was used to determine the relationship between motor speech function and motor impairment and between VHI and MDVP parameters across both medication conditions. The interrater reliability rating was established using Cohen's kappa.

Results An improvement in lip and laryngeal functioning was found in the medication ON over medication OFF state in both males and females with PD. A few frequency and amplitude-related measures improved in the medication-ON state over the medication-OFF state. UPDRS-III scores reduced from the OFF state to the ON state, and no change in dysarthria severity or VHI was found in either gender or medication condition. No correlation was found between speech motor function and motor function or between VHI and acoustic parameters of voice in either medication condition.

Conclusions Improvement in motor symptoms with levodopa was predominantly observed when compared with the minor improvements in a few aspects of speech motor function and vocal parameters. The results of this study suggest the need for speech therapy as a nonpharmacological treatment method for speech impairments in PD.
Impact of Stroke on Quality of Life of Stroke Survivors and Their Caregivers: A Qualitative Study from India
Authors: Tiwari Sharad , Joshi Ankur , Rai Nirendra , Satpathy Parmeshwar
Published: September 2021

Objectives Stroke is a significant global public health challenge attributable to an array of disabilities it causes alongside an impairment in cognition. The monetary impact of stroke care includes acute treatment expenses as well as outrageous expenses of postdischarge chronic hospital care and rehabilitation services. The current study aimed to study the perceptions along with experiences of stroke survivors and caregivers.

Materials and Methods In-depth interviews (IDIs) of stroke survivors and their primary caregivers were conducted at their home 2 months after their discharge from the hospital in Bhopal, India. These IDIs were later analyzed.

Results The following eight themes emerged: pervasive and irreversible, multifunction loss and dependency, holistic impact on the health of person and family, money and matter, nonaccommodative cost and baffled belief, professional paralysis, social crisis, and slow and obscured progress. The added obligation of taking care of a disabled stroke survivor along with adjusting their own lifestyle with financial apprehensions, worry about future, prolonged hours of care, and stress are major factors that increase the burden of the caregivers.

Conclusion Caregivers should be sensitized with proper counseling and training through health care institutions to ensure appropriate care and management of stroke survivors at home, as it will also help in addressing their psychosocial needs, and minimizing the knowledge gap, doubts and uncertainties about the disease and its aftereffects.
A Microbiological Study of Acinetobacter calcoaceticus baumannii with Special Reference to Multidrug Resistance
Authors: Longjam Langamba Angom , Tsering Dechen Chomu , Das Dipmala
Published: September 2021

Introduction The outbreak of Acinetobacter calcoaceticus baumannii (ACB) is mainly reported to be a notorious pathogens at health-care settings. It is the major problem on the health-care system with high morbidity and mortality rates because of the broad range of antibiotic resistance and lack of understanding the mechanism of developing new antibiotic resistance rapidly. It emphasizes the importance of local surveillance in describing or understanding and predicting microbial resistance patterns so that there will be limited use of antibiotics by developing strategies to control the extensive use of antimicrobial chemotherapy in clinical environment, which is still considered as one of the factors in the emergence of multidrug resistance microorganisms.

Objectives The study aims to detect the occurrence rate of ACB infections from various clinical samples, identify the resistance levels to different groups of antimicrobial agents, and the occurrence rate of multidrug resistant (MDR) ACB clinical isolates from a tertiary hospital in Durgapur, West Bengal, India.

Material and Methods The study was performed in the Department of Microbiology of the IQ City Medical College and Hospital, Durgapur, West Bengal, India, for the 24 months duration, that is, from January 1, 2018 to December 31, 2019. Altogether 15,800 clinical samples consisting of endotracheal tube aspirates, sputum, pus, blood, catheter tips, urine, tissue, and other body fluids were studied. ACB from clinical samples were identified by its characteristic colonies (nonlactose fermenting, glistening, small mucoid colonies), Gram-staining pattern (Gram-negative coccobacillus), and standard biochemical reactions. It was further confirmed in the Department of Microbiology of the Healthworld Hospital, Durgapur, West Bengal, India, by Vitek2 compact system (bioMerieux, Inc., Durham, North Carolina, United States). Antibiotic susceptibility testing was performed using automated broth microdilutions by Vitek2 compact system (bioMerieux, Inc.) and Kirby-Bauer disk diffusion test on Mueller-Hinton Agar (HiMedia).

Results Nonrepetitive 289 ACB were isolated from various clinical samples. A total of 277 (96%) isolates of ACB were MDR strains.

Conclusion ACB was mostly isolated from the intensive care unit department and was found to be the most MDR type in the tertiary care hospital by this study.
Less Invasive Surfactant Administration in Very Prematurely Born Infants
Authors: Shetty Sandeep , Egan Helen , Cornuaud Peter , Kulkarni Anay , Duffy Donovan , Greenough Anne
Published: September 2021

Background Less invasive surfactant administration (LISA) is the preferred mode of surfactant administration for spontaneously breathing preterm babies supported by noninvasive ventilation (NIV).

Objective The aim of this study was to determine whether LISA on the neonatal unit or in the delivery suite was associated with reduced rates of bronchopulmonary dysplasia (BPD) or the need for intubation, or lower durations of invasive ventilation and length of hospital stay (LOS).

Methods A historical comparison was undertaken. Each “LISA” infant was matched with two infants (controls) who did not receive LISA.

Results The 25 LISA infants had similar gestational ages and birth weights to the 50 controls (28 [25.6–31.7] weeks vs. 28.5 [25.4–31.9] weeks, p = 0.732; 1,120 (580–1,810) g vs. 1,070 [540–1,869] g, p = 0.928), respectively. LISA infants had lower requirement for intubation (52 vs. 90%, p < 0.001), shorter duration of invasive ventilation (median 1 [0–35] days vs. 6 [0–62] days p = 0.001) and a lower incidence of BPD (36 vs. 64%, p = 0.022). There were no significant differences in duration of NIV (median 26 [3–225] vs. 23 [2–85] days, p = 0.831) or the total LOS (median 76 [24–259] vs. 85 [27–221], p = 0.238).

Conclusion LISA on the neonatal unit or the delivery suite was associated with a lower BPD incidence, need for intubation, and duration of invasive ventilation.
Extremely thin reflective metasurface for low-frequency underwater acoustic waves: Sharp focusing, self-bending, and carpet cloaking
Authors: Chen Zhong , Yan Fei , Negahban Mehrdad , Li Zheng
Published: September 2021

An extremely thin metasurface is proposed for manipulating underwater reflected waves. Each metasurface unit is only 1/61.7 of the target wavelength in thickness and comprises an air cavity capped with a thin vibration plate held in place by rubber spacers on steel supports. The unit-cell design is thin, simple, and can be adjusted to obtain a full 2π phase shift in water waves that are reflected from the metasurface. It also provides this phase shift for a broad frequency range of 20–800 Hz for incident waves. The effectiveness of the design and the resolution of the expected effect is demonstrated for sharp focusing, self-bending, and directional carpet cloaking, which are applications with great potential in energy harvesting, underwater communication, and submarine stealth and antidetection.
A compact and fast magnetic coil for the manipulation of quantum gases with Feshbach resonances
Authors: Kell A. , Link M. , Breyer M. , Hoffmann A. , Köhl M. , Gao K.
Published: September 2021

Cold atom experiments commonly use broad magnetic Feshbach resonances to manipulate the interaction between atoms. In order to induce quantum dynamics by a change in the interaction strength, rapid (∼μs) magnetic field changes over several tens of Gauss are required. Here, we present a compact design of a coil and its control circuit for a change in the magnetic field up to 36 G in 3 µs. The setup comprises two concentric solenoids with minimal space requirements, which can be readily added to existing apparatuses. This design makes the observation of non-equilibrium physics with broad Feshbach resonances accessible.
Relaxation modes of metaphosphate glasses with entropic shrinkage
Authors: Yaoita Takatoshi , Inaba Seiji
Published: September 2021

We have reconfirmed the anomalistic reversible strain (shrinkage) after tensile creep in the specific metaphosphate glass melts with entropic elasticity in a wide range of applied stresses. We attempted to elucidate the origin of the anomalistic shrinkage by focusing on the relaxation modes. The fast mode was identified for all glasses by two different measurements, i.e., the dynamic viscoelasticity in the linear range and the creep recovery in the non-linear range. In contrast, the slow mode in addition to the fast mode was confirmed only for the glasses showing the anomalistic shrinkage. The slow mode induced the essential shrinkage at whole tensile stresses, whereas the fast mode, especially at higher tensile stresses, contributed to the moderate shrinkage. As the most likely mechanism in the linear range, the local segmental motion with mobile cation motion and the large-scale relaxation of the connected molecules through scission and renewal of the bond between alkali cations and the oxygen anion were assigned to the fast and the slow modes, respectively. In the non-linear range, the dimensionless strain-rate dependence of the reversible strains for both modes had a similar characteristic to that of the viscosity.
Fast optimal entrainment of limit-cycle oscillators by strong periodic inputs via phase-amplitude reduction and Floquet theory
Authors: Takata Shohei , Kato Yuzuru , Nakao Hiroya
Published: September 2021

Optimal entrainment of limit-cycle oscillators by strong periodic inputs is studied on the basis of the phase-amplitude reduction and Floquet theory. Two methods for deriving the input waveforms that keep the system state close to the original limit cycle are proposed, which enable the use of strong inputs for entrainment. The first amplitude-feedback method uses feedback control to suppress deviations of the system state from the limit cycle, while the second amplitude-penalty method seeks an input waveform that does not excite large deviations from the limit cycle in the feedforward framework. Optimal entrainment of the van der Pol and Willamowski–Rössler oscillators with real or complex Floquet exponents is analyzed as examples. It is demonstrated that the proposed methods can achieve considerably faster entrainment and provide wider entrainment ranges than the conventional method that relies only on phase reduction.
Ultrafast relaxation dynamics of Au38(SC6H13)24 monolayer-protected clusters resolved by two-dimensional electronic spectroscopy
Authors: Jeffries William R. , Foxley Juniper , Knappenberger Kenneth L.
Published: September 2021

Electronic relaxation dynamics of neutral Au38(SC6H13)24 monolayer-protected clusters (MPCs), following excitation of the mixed 15 875 cm−1 charge transfer resonance, were studied using femtosecond transient absorption (fsTA) and two-dimensional electronic spectroscopy (2DES). The excited carriers relax by three different mechanisms, including an ∼100 fs HOMO−12/−13 to HOMO−4/−6 hole transfer, picosecond HOMO−4/−6 to HOMO hole transfer, and subsequent electron–hole recombination that persisted beyond the hundreds of picoseconds measurement range. The fsTA data revealed two transient bleach components at 15 820 and 15 625 cm−1, where the lower frequency component exhibited a delayed first-order buildup of 80 ± 25 fs that matched the decay of the high-energy bleach component (110 ± 45 fs). These results suggested that the excited charge carriers internally relax within the exited-state manifold in ≈100 fs. 2DES resolved multiple electronic fine-structure transient peaks that spanned excitation frequencies ranging from 15 500 to 16 100 cm−1. State-to-state dynamics were understood by the analysis of time-dependent 2DES transient signal amplitudes at numerous excitation-detection frequency combinations. An off-diagonal cross peak at 15 825–15 620 cm−1 excitation-detection signified the HOMO−12/−13 to HOMO−4/−6 hole transfer process. The lowest-frequency (15 620 cm−1) 2DES diagonal fine-structure peak exhibited instantaneous amplitude but intensified following a 75 ± 10 fs buildup when compared to diagonal peaks at higher frequencies. This observation indicated that the charge transfer resonance in Au38(SC6H13)24 MPCs is comprised of several electronic transitions of unique spectral weights, which may result from different orbital contributions associated with specific cluster domains. The use of 2DES in combination with structurally precise MPCs can provide a platform for understanding structure-dependent electronic dynamics in metal nanoclusters and technologically important metal–chalcogenide interfaces.
Laboratory-size x-ray microscope using Wolter mirror optics and an electron-impact x-ray source
Authors: Ohba Akira , Nakano Tomoyasu , Onoda Shinobu , Mochizuki Takahiro , Nakamoto Katsuhiro , Hotaka Hisaya
Published: September 2021

We developed a laboratory-size three-dimensional water-window x-ray microscope using condenser and objective grazing incidence Wolter type I mirrors, an electron-impact-type x-ray source, and a back-illuminated CCD. The imaging system was improved for practical applications in life science research fields. Using a new objective mirror with reduced figure errors, a resolution limit of 3.1 line pairs/μm was achieved for two-dimensional transmission images and sub-micrometer-scale three-dimensional structures were resolved. Incorporating a cryogenic stage into the x-ray microscope, we observed biological samples embedded in ice to evaluate the usefulness of observation in the water-window region and multi-energy observation was demonstrated using an x-ray source with multiple x-ray tubes.
Deposition of conformal thin film coatings on sawtooth substrates using ion bombardment
Authors: Randel Emmett , Bradley R. Mark , Menoni Carmen S.
Published: September 2021

When a nominally flat surface is bombarded with a broad ion beam at oblique incidence, nanoscale ripples often develop on the surface. For high angles of incidence, surfaces typically develop into a terraced form at the late stages of their time evolution. In the present work, this process is exploited to prevent unwanted smoothing of ordered terraced substrates during the deposition of thin films. A Si surface prepatterned with a 500 nm pitch binary grating structure was bombarded at oblique incidence by a low energy Xe+ ion beam to establish an ordered terraced topography. Subsequently, Si/SiO2 bilayers were deposited on the surface, and further oblique incidence Xe+ bombardment was performed following the deposition of each Si layer to re-establish the ordered terraced topography. Self-organized processes, such as in the present work, that only require exposure of a surface to a plasma or ion source have the potential to provide a simple and inexpensive route for fabricating large-area nanostructured surfaces. The presented procedure has potential applications in the fabrication of multilayer blazed gratings for use in the extreme ultraviolet or soft x-ray regimes.
Coupling improved discrete velocity method and G13-based gas kinetic flux solver: A hybrid method and its application for non-equilibrium flows
Authors: Liu W. , Liu Y. Y. , Yang L. M. , Liu Z. J. , Yuan Z. Y. , Shu C. , Teo C. J.
Published: September 2021

From the aspect of the multiscale nature of the rarefied flow, a simple hybrid strategy is proposed in this paper in the process of flux reconstruction to couple the improved discrete velocity method (IDVM) and the G13-based gas kinetic flux solver (G13-GKFS). The flow field is divided into the IDVM area and G13 area according to the kinetic nature of the Knudsen layer and the criteria of the local Knudsen number. By eliminating the storage of the distribution functions and evolution of the microscopic equation, the reduction of the computational effort and memory storage can be achieved without sacrificing the accuracy in the whole flow field. Four different non-equilibrium cases from the micro-flow to the supersonic flow are tested by the present hybrid method. The results show good performance and better efficiency. Furthermore, under the framework of the present hybrid method, different non-equilibrium distribution functions with higher-order moments could be employed and coupled easily.
MB-Fit: Software infrastructure for data-driven many-body potential energy functions
Authors: Bull-Vulpe Ethan F. , Riera Marc , Götz Andreas W. , Paesani Francesco
Published: September 2021

Many-body potential energy functions (MB-PEFs), which integrate data-driven representations of many-body short-range quantum mechanical interactions with physics-based representations of many-body polarization and long-range interactions, have recently been shown to provide high accuracy in the description of molecular interactions from the gas to the condensed phase. Here, we present MB-Fit, a software infrastructure for the automated development of MB-PEFs for generic molecules within the TTM-nrg (Thole-type model energy) and MB-nrg (many-body energy) theoretical frameworks. Besides providing all the necessary computational tools for generating TTM-nrg and MB-nrg PEFs, MB-Fit provides a seamless interface with the MBX software, a many-body energy and force calculator for computer simulations. Given the demonstrated accuracy of the MB-PEFs, particularly within the MB-nrg framework, we believe that MB-Fit will enable routine predictive computer simulations of generic (small) molecules in the gas, liquid, and solid phases, including, but not limited to, the modeling of quantum isomeric equilibria in molecular clusters, solvation processes, molecular crystals, and phase diagrams.
Visualization of intracellular lipid metabolism in brown adipocytes by time-lapse ultra-multiplex CARS microspectroscopy with an onstage incubator
Authors: Takei Yuki , Hirai Rie , Fukuda Aya , Miyazaki Shinichi , Shimada Rintaro , Okamatsu-Ogura Yuko , Saito Masayuki , Leproux Philippe , Hisatake Koji , Kano Hideaki
Published: September 2021

We visualized a dynamic process of fatty acid uptake of brown adipocytes using a time-lapse ultra-broadband multiplex coherent anti-Stokes Raman scattering (CARS) spectroscopic imaging system with an onstage incubator. Combined with the deuterium labeling technique, the intracellular uptake of saturated fatty acids was traced up to 9 h, a substantial advance over the initial multiplex CARS system, with an analysis time of 80 min. Characteristic metabolic activities of brown adipocytes, such as resistance to lipid saturation, were elucidated, supporting the utility of the newly developed system.
Lattice-matched AlInN/GaN multi-channel heterostructure and HEMTs with low on-resistance
Authors: Li Ang , Wang Chong , Xu Shengrui , Zheng Xuefeng , He Yunlong , Ma Xiaohua , Lu Xiaoli , Zhang Jinfeng , Liu Kai , Zhao Yaopeng , Hao Yue
Published: September 2021

In this paper, a high-performance multi-channel heterostructure based on lattice-matched AlInN/GaN has been reported. The stacking of five heterostructures yields a high two-dimensional electron gas density of 3.67 × 1013 cm−2 and a small sheet resistance (RSH) of 74.5 Ω/sq. Compared with the AlGaN/GaN sample with the same number of heterojunctions, the AlInN/GaN sample reduces the RSH by 51.2%. Since the AlInN barrier and GaN channel are lattice-matched, the strain defects caused by piezoelectric strain can be alleviated. The high-resolution x-ray diffraction results show that the total dislocation density in AlInN/GaN multi-channels is reduced by 18.9%. The calculation models of multiple-channel heterostructures are obtained to investigate the electron population and energy band diagram, and the calculated results are roughly consistent with the experimental results. With a gate–drain spacing of 11.5 μm, the on-resistance (RON) of the AlInN/GaN multi-channel HEMT was only 2.26 Ω mm, indicating that the lattice-matched multi-channel AlInN/GaN heterostructure can substantially enhance the current drive efficiency and improve the output performance of the devices.
CODATA Recommended Values of the Fundamental Physical Constants: 2018
Authors: Tiesinga Eite , Mohr Peter J. , Newell David B. , Taylor Barry N.
Published: September 2021

We report the 2018 self-consistent values of constants and conversion factors of physics and chemistry recommended by the Committee on Data of the International Science Council. The recommended values can also be found at physics.nist.gov/constants. The values are based on a least-squares adjustment that takes into account all theoretical and experimental data available through 31 December 2018. A discussion of the major improvements as well as inconsistencies within the data is given. The former include a decrease in the uncertainty of the dimensionless fine-structure constant and a nearly two orders of magnitude improvement of particle masses expressed in units of kg due to the transition to the revised International System of Units (SI) with an exact value for the Planck constant. Further, because the elementary charge, Boltzmann constant, and Avogadro constant also have exact values in the revised SI, many other constants are either exact or have significantly reduced uncertainties. Inconsistencies remain for the gravitational constant and the muon magnetic-moment anomaly. The proton charge radius puzzle has been partially resolved by improved measurements of hydrogen energy levels.