bluuebunny/crossref_metadata_2025 huggingface dataset:
Error factors of AC-DC conversion circuits accuracy
Authors: Jia Dongyu , Yan Ming , Feng Rongwei , Li Shuangyu
Published: December 2021

Voltage standard source is an important basic instrument in the electrical measurement and testing field, and it has important guarantee significance for many industries. AC voltage standard source is based on AC-DC conversion technology to achieve output function of high precision AC voltage. In order to get a better effect of AC-DC conversion, the three factors—operational amplifier, resistance and diode—that have a greater impact on the accuracy of the rectifier output were taken the research object, and their impacts on the circuit error were analyzed respectively. The output result was compared with the output of full wave precision rectification circuit under ideal state, and the scheme of reducing error in the precision rectifier circuit was summarized, which provides a reference for improving the accuracy of AC-DC conversion in the design of full wave rectifier circuit.
Damage Degree analysis of storage failure modes for plastic encapsulated microelectronic devices
Authors: Ju Hang , Liu Shuang
Published: December 2021

After long-term storage, plastic sealing devices must have good performance when installed on the whole machine. Identifying the risk of failure mode and taking preventive measures before failure can effectively improve storage reliability. To ensure the quality of military products, this paper studies the storage failure modes of plastic sealed micro-electronic devices, and uses the method of FMECA to calculate the damage degree of each failure mode and determine the key failure modes. The case analysis shows that the damage degree of failure mode is ranked as external lead corrosion, aging of packaging material, chip corrosion and bonding ball corrosion. The evaluation result accords with the actual situation of the method. The improved FMECA model can better deal with the relative importance of risk factors, improve the accuracy of risk ranking, and quantify risks more reasonably.
Lateral/Directional Control Law Design for Civil Airplane Based on Eigen Structure Assignment
Authors: Li Bingbing , Xu Dongguang , Zheng Xiaohui , Zheng Bowen
Published: December 2021

Considering disadvantages of lateral/directional mode characteristics of civil aircraft, design requirements are thus presented and the P-Beta control law architecture is adopted for the lateral/directional control law. Meanwhile, the practical application of eigen structure assignment in the design of lateral/directional control law is studied. By eigen structure assignment the closed loop is designed, and the decoupling of roll channel and yaw channel is realized. Through the design of feed-forward command channel, the pilot’s stick control roll rate and pedal control sideslip angle are realized. Simulation results show that the designed lateral/directional flight control law could meet design requirements.
Research on Dynamic Characteristics of Constant Power Control of Plunger Pump Variable Regulator
Authors: Dong Haoming , Jin Xiajie , Xing Keli
Published: December 2021

This article takes K3VDT63 variable plunger pump original regulator as the research object, establishes its dynamic motion equation, uses matlab simulation software to establish its simulation model on the basis of this equation, and the dynamic characteristics of the simulation model under different physical parameters Experiment, and get the dynamic response curve and result of variable regulator constant power control under the influence of various factors.
Physical characterization of biopolymers with starch from potato and cassava organic wastes polymerized in water
Authors: Quintana D N , Sanabria D P , Castro H F , Roa K L , Paredes R A , Vargas Y C
Published: December 2021

During the last decades, the use of plastic has become indispensable for the daily life of people; the global production of these materials reaches approximately more than 200 million tons per year. For this reason, research has been carried out to manufacture substitute materials that have similar physical properties, such as starch-based biopolymers; in this research we initially characterized the physical properties of a biopolymer based on starch polymerized in water, without plasticizers, and also to find an optimal proportion between starch and water; in this way an experimental design is generated where the proportion of these two varies, in which starch extracted from potato and cassava wastes was used. These biopolymers were characterized for linear shrinkage, density, and hardness properties. The results of the characterizations showed that the proportions lower than 1:5 starch-water present difficulty to process and deficiency in the homogeneity of the mixture, while the proportions higher than 1:5 presented a linear shrinkage higher than 82. 69% and a loss in weight higher than 74.45%; on the other hand, the hardness analysis showed an average of 79 points on the shore A scale and density with an average of 1.055 g/cm3, the results determined that the most adequate proportion is 1:6.5 starch-water.
Statistical analysis of cutting tool wear in machining centers
Authors: Arévalo-Ruedas J H , Espinel-Blanco E , Florez-Solano E
Published: December 2021

Cutting tools have great use in the industry for their great effectiveness at the time of use, but it is important to know what the proper use is, because the misuse or constant use of such tools, can cause excessive wear and tear that will reduce tool life. There are different methods and equations to measure the useful life of the tool, it is important to know its state so that at the time of being used in a machining process does not cause irreversible damage to the part. One of the most well-known equations is the Taylor equation where they relate useful lifetime to cutting speed. This project was developed in order to demonstrate, by means of equations and graphs, the lifetime and wear of the cutting tools, as well as the application of statistical equations that allow the analysis of the results obtained in the laboratory; a statistical study was able to evaluate the wear on the cutting tool, obtaining statistically the useful life of the tool in each machining process and calculate in the same way the total useful life of the tool.
Low energy event classification in IceCube using boosted decision trees
Authors: Leonard DeHolton K.
Published: December 2021

The DeepCore sub-array within the IceCube Neutrino Observatory is a densely instrumented region of Antarctic ice designed to observe atmospheric neutrino interactions above 5 GeV via Cherenkov radiation. An essential aspect of any neutrino oscillation analysis is the ability to accurately identify the flavor of neutrino events in the detector. This task is particularly difficult at low energies when very little light is deposited in the detector. Here we discuss the use of machine learning to perform event classification at low energies in IceCube using a boosted decision tree (BDT). A BDT is trained using reconstructed quantities to identify track-like events, which result from muon neutrino charged current interactions. This new method improves the accuracy of particle identification compared to traditional classification methods which rely on univariate straight cuts.
Embedded software developments in KM3NeT phase I
Authors: van Beveren V. , Real D. , Chiarusi T. , Calvo D. , Mastroianni S. , Musico P. , Pellegrini G. , Jansweijer P. , Colonges S. , Bozza C. , Filippini F. , Nicolau C. , Díaz A.
Published: December 2021

The KM3NeT collaboration has already produced more than one thousand acquisition boards, used for building two deep-sea neutrino detectors at the bottom of the Mediterranean Sea, with the aim of instrumenting a volume of several cubic kilometers with light sensors to detect the Cherenkov radiation produced in neutrino interactions. The so-called digital optical modules, house the PMTs and the acquisition and control electronics of the module, the central logic board, which includes a Xilinx FPGA and embedded soft processor. The present work presents the architecture and functionalities of the software embedded in the soft processor of the central logic board.
Demonstrating a single-block 3D-segmented plastic-scintillator detector
Authors: Boyarintsev A. , De Roeck A. , Dolan S. , Gendotti A. , Grynyov B. , Kose U. , Kovalchuk S. , Nepokupnaya T. , Rubbia A. , Sgalaberna D. , Sibilieva T. , Zhao X.Y.
Published: December 2021

Three-dimensional finely grained plastic scintillator
detectors bring many advantages in particle detectors, allowing a
massive active target which enables a high-precision tracking of
interaction products, excellent calorimetry and a sub-nanosecond
time resolution. Whilst such detectors can be scaled up to
several-tonnes, as required by future neutrino experiments, a
relatively long production time, where each single
plastic-scintillator element is independently manufactured and
machined, together with potential challenges in the assembly,
complicates their realisation. In this manuscript we propose a novel
design for 3D granular scintillator detectors where
O(1 cm3) cubes are efficiently glued in a single block of
scintillator after being produced via cast polymerization, which can
enable rapid and cost-efficient detector construction. This work
could become particularly relevant for the detectors of the
next-generation long-baseline neutrino-oscillation experiments, such
as DUNE, Hyper-Kamiokande and ESSnuSB.
Modeling of U-shaped composite detectors
Authors: Chakraborty A. , Kshetri R. , Patra A.S.
Published: December 2021

We have investigated the basic operation of a composite
detector comprising of elements arranged in the shape of an U-shaped
rectangular well. Considering an isotropic scattering of gamma-rays
and partial energy absorptions in up to four detector modules,
expressions for the addback factor and the peak-to-total ratio have
been obtained in terms of only one probability amplitude. We have
compared the performance of two U-shaped detectors having different
geometries and observed negligible gain in addback due to the longer
arms. For completeness, comparisons have been made with composite
detectors like the two element stacked detector and the two level
pyramidal detector, both being embedded inside the U-shaped
detector. Our pen-on-paper approach could be used to understand the
operation of modern arrays having detector elements arranged in
various sophisticated ways.
A review of the importance of mineral nitrogen cycling in the plant-soil-microbe system of permafrost-affected soils—changing the paradigm
Authors: Ramm Elisabeth , Liu Chunyan , Ambus Per , Butterbach-Bahl Klaus , Hu Bin , Martikainen Pertti J , Marushchak Maija E , Mueller Carsten W , Rennenberg Heinz , Schloter Michael , Siljanen Henri M P , Voigt Carolina , Werner Christian , Biasi Christina , Dannenmann Michael
Published: December 2021

The paradigm that permafrost-affected soils show restricted mineral nitrogen (N) cycling in favor of organic N compounds is based on the observation that net N mineralization rates in these cold climates are negligible. However, we find here that this perception is wrong. By synthesizing published data on N cycling in the plant-soil-microbe system of permafrost ecosystems we show that gross ammonification and nitrification rates in active layers were of similar magnitude and showed a similar dependence on soil organic carbon (C) and total N concentrations as observed in temperate and tropical systems. Moreover, high protein depolymerization rates and only marginal effects of C:N stoichiometry on gross N turnover provided little evidence for N limitation. Instead, the rather short period when soils are not frozen is the single main factor limiting N turnover. High gross rates of mineral N cycling are thus facilitated by released protection of organic matter in active layers with nitrification gaining particular importance in N-rich soils, such as organic soils without vegetation. Our finding that permafrost-affected soils show vigorous N cycling activity is confirmed by the rich functional microbial community which can be found both in active and permafrost layers. The high rates of N cycling and soil N availability are supported by biological N fixation, while atmospheric N deposition in the Arctic still is marginal except for fire-affected areas. In line with high soil mineral N production, recent plant physiological research indicates a higher importance of mineral plant N nutrition than previously thought. Our synthesis shows that mineral N production and turnover rates in active layers of permafrost-affected soils do not generally differ from those observed in temperate or tropical soils. We therefore suggest to adjust the permafrost N cycle paradigm, assigning a generally important role to mineral N cycling. This new paradigm suggests larger permafrost N climate feedbacks than assumed previously.
Early-winter North Atlantic low-level jet latitude biases in climate models: implications for simulated regional atmosphere-ocean linkages
Authors: Bracegirdle Thomas J , Lu Hua , Robson Jon
Published: December 2021

Climate model biases in the North Atlantic (NA) low-level tropospheric westerly jet are a major impediment to reliably representing variability of the NA climate system and its wider influence, in particular over western Europe. A major aspect of the biases is the occurrence of a prominent early-winter equatorward jet bias in Coupled Model Inter-comparison Project Phase 5 (CMIP5) models that has implications for NA atmosphere-ocean coupling. Here we assess whether this bias is reduced in the new CMIP6 models and assess implications for model representation of NA atmosphere-ocean linkages, in particular over the sub-polar gyre (SPG) region. Historical simulations from the CMIP5 and CMIP6 model datasets were compared against reanalysis data over the period 1861–2005. The results show that the early-winter equatorward bias remains present in CMIP6 models, although with an approximately one-fifth reduction compared to CMIP5. The equatorward bias is mainly associated with a weaker-than-observed frequency of poleward excursions of the jet to its northern position. A potential explanation is provided through the identification of a strong link between NA jet latitude bias and systematically too-weak model-simulated low-level baroclinicity over eastern North America in early-winter. CMIP models with larger equatorward jet biases exhibit weaker correlations between temporal variability in speed of the jet and sea surface conditions (sea surface temperatures and turbulent heat fluxes) over the SPG. The results imply that the early-winter equatorward bias in jet latitude in CMIP models could partially explain other known biases, such as the weaker-than-observed seasonal-decadal predictability of the NA climate system.
Modeling of colloidal systems in technological processes
Authors: Belenko E V , Sakharov P A , Khvatov A V , Lukanina Yu K
Published: December 2021

The article describes the main methods of mathematical modeling of industrial free-dispersed systems. The method of constructing the regression equation by the method of linear and nonlinear installation of coefficients is proposed. The fundamentals of tensor and harmonic approaches to the analysis of disperse systems are considered, which allow optimizing the equations of material and energy balance in the conditions of industrial operation of dispersions.
The application of basin modeling of oil and gas systems for seismogeological projects for assessment of hydrocarbon potential and risks of exploration work
Authors: Trigub A V , Chereneva K R
Published: December 2021

In this article, the methodology of basin modeling was systematized and the sequence of solutions to the applied problems related to the forecast of deposits of oil and gas was updated, and the applicability of basin modeling to traditional regional projects was evaluated.
Soil cryogenesis as a natural risk factor for gas pipelines in the permafrost zone during modern warming
Authors: Khudyakov I , Reshotkin O V , Demin D V
Published: December 2021

The paper summarizes the experience of studying the effect of modern warming on the thawing depth of sandy and loamy soils in the permafrost zone. The definition of soil cryogenesis as a natural process and facies as the end result of soil cryogenesis as a process is given. The effect of soil cryogenesis facies on stress corrosion cracking of gas pipes of the Gazprom system in cold and warm seasons has been studied. It was found that the facies of soil cryogenesis are interconnected by the process of energy and mass exchange. It is shown that in the annual cycle, each facies formed by soil cryogenesis is the basis for the development of stress corrosion cracking of gas pipelines.
Development of polymer emulsions stabilized with anionic polyelectrolytes
Authors: Khvatov A V , Sakharov P A , Lukanina Yu K , Belenko E V
Published: December 2021

The colloidal-chemical principles of the formation of reversibly reversible microemulsions based on compositions of anionic polysaccharides, higher fatty acids, and nonionic polyoxyethylated surfactants have been investigated. The structural formula of the interpolymer complex in the “polyelectrolyte - surfactant” system was proposed, and the molar ratios of the components were determined. The effectiveness of the developed polymer emulsions as drilling fluids for the construction of oil wells is shown.
Application of Machine Learning Algorithms in Predicting Pyrolytic Analysis Result
Authors: Suong Le Thi Nhut , Bondarev A V , Kozlova E V
Published: December 2021

Geochemical studies of organic matter in source rocks play an important role in predicting the oil and gas accumulation of any territory, especially in oil and gas shale. For deep understanding, pyrolytic analyses are often carried out on samples before and after extraction of hydrocarbon with chloroform. However, extraction is a laborious and time-consuming process and the workload of laboratory equipment and time doubles. In this work, machine learning regression algorithms is applied for forecasting S2ex based on the pyrolytic analytic result of non-extracted samples. This study is carried out using more than 300 samples from 3 different wells in Bazhenov formation, Western Siberia. For developing a prediction model, 5 different machine learning regression algorithms including Multiple Linear Regression, Polynomial Regression, Support vector regression, Decision tree and Random forest have been tested and compared. The performance of these algorithms is examined by R-squared coefficient. The data of the X2 well was used for building a model. Simultaneously, this data is divided into 2 parts – 80% for training and 20% for checking. The model also was used for prediction of wells X1 and X3. Then, these predictive results were compared with the real results, which had been obtained from standard experiments. Despite limited amount of data, the result exceeded all expectations. The result of prediction also showcases that the relationship between before and after extraction parameters are complex and non-linear. The proof is R2 value of Multiple Linear Regression and Polynomial Regression is negative, which means the model is broken. However, Random forest and Decision tree give us a good performance. With the same algorithms, we can apply for prediction all geochemical parameters by depth or utilize them for well-logging data.
Distributions of environmental parameters and fish at Humbold Bay, Jayapura
Authors: Pujiyati S , Hamuna B , Hisyam M , Rohilah  , Azzah A H , Sunarwati E , Pasaribu R
Published: December 2021

Research on the distribution of fish and plankton in waters that are equipped with environmental parameters is needed to obtain maximum results and increase accuracy also it provides comprehensive information. The research, which was conducted in Humbold Bay, aimed to map the fish and plankton distribution data both vertically and horizontally and combine it with environmental parameters in the bay. Fish and plankton’s data was the volume backscattering strength (Sv) value obtained using the SIMRAD EK-15 device while environmental parameter data, such as temperature, salinity, and chlorophyll obtained from marine.copernicus.eu which processed in the 5-80 m depth range. The results showed that Humbold Bay had the highest average surface temperature distribution was 30 °C, with the highest average salinity from 35.89 ppt and the highest average chlorophyll value from 0.3859 mg/m3. The horizontal distribution of plankton had an average SV value of -76.63 dB, while the fish was -56.00 dB that evenly distributed. Vertically, the Sv of plankton decreased with increasing depth as well as the Sv of fish which its’ also did not have a distribution pattern in certain environmental parameters.
Unmanned Surface Vehicle (USV) performance test in Bintan Island Waters
Authors: Fauzi R , Jaya I , Iqbal M
Published: December 2021

An unmanned surface vehicle (USV) is an unmanned vehicle that is operated on the surface of the water for certain purposes, for example, bathymetry measurement, underwater imaging, etc. These unmanned surface vehicles can be used in impassable waters for crewed vessels in dangerous waters. This research measures the movement of the vehicle acceleration and then calculates it as the USV roll and pitch values. The direction of movement and wind speed and the height of the water surface at low tide are also aspects measured in this research. An accelerometer is a sensor that can measure the acceleration of an object, both dynamic and static. Based on the observations, the highest roll value is 6.0° deep while the highest pitch value is 6.5°. The standard deviation value at roll conditions of 2.92 and the standard deviation value at pitch conditions of 1.25. The average frequency of roll conditions is 2.18 and pitch conditions of 1.13. The dominant wind moves from the south to the southwest with a dominant speed ranging from 3.0 to 4.0 m/s. The results of this research indicate that the USV has a good performance so that it is possible to collect data in the water.
Segmentation of seagrass (Enhalus acoroides) using deep learning mask R-CNN algorithm
Authors: Lestari N A , Jaya I , Iqbal M
Published: December 2021

Seagrass is an Angiosperms that live in shallow marine waters and estuaries. The method commonly used to identify seagrass is Seagrass-Watch which is done by sampling seagrass or by carrying a seagrass identification book. Technological developments in the era of the industrial revolution 4.0 made it possible to identify seagrass automatically. This research aims to apply the deep learning algorithm to detect seagrass recorded by underwater cameras. Enhalus acoroides seagrass species identification was carried out using a deep learning method with the mask region convolutional neural networks (Mask R-CNN) algorithm. The steps in the research procedure include collecting, labeling, training, testing models, and calculating the seagrass area. This study used 6000 epochs and got a measure of value generated by the model of ± 1.2. The Precision value, namely the model’s ability to correctly classify objects, reached 98.19% and the model’s ability to find all positive objects, based on system testing was able to perform recall is 95.04% and the F1 Score value of 96.58%. The results showed that the MASK R-CNN algorithm could detect and segment seagrass Enhalus acoroides.
Spatial and temporal analysis for mangrove community healthiness in Liki Island, Papua-Indonesia
Authors: Nurdiansah D , Dharmawan I W E
Published: December 2021

Indonesian mangrove declined significantly in the last two decades which has been considered to deliver a negative impact for adjacent communities in small islands. Mangrove quality monitoring was conducted during Nusa Manggala Expedition in 2018, which was aimed to analyze forest structure and healthiness using spatial-temporal investigation in Liki island, Papua. Field data were collected from 10m-×-10m quadratic plots which were distributed following stratified purposive sampling method. Spatial and temporal was implemented using Sentinel 2 imagery on this area from 2016 to 2021. The result of this field study had considered that mangrove in Liki island was in moderate healthiness since the MHI value was between 33.33%-66.67%. It was supported by remote sensing analysis in 2018 which showed that the moderate MHI area was dominant by approximately 42% compared to the excellent area in about 33%. Liki’s mangrove had experienced a declining trend of excellent category from 2016 and reached the lowest area of its category in 2018. In the last four-year observation, excellent areas gradually increased which was covering 57.68% of forest MHI. The dynamic of mangrove healthiness on this island tended to be delivered by natural events.
Distribution and diversity of gelatinous zooplankton in the southern South China Sea
Authors: Kamaruddin N A , Ishak N H A
Published: December 2021

Although gelatinous zooplankton are widely distributed in many ocean ecosystems, they have been understudied due to their fragility nature, difficulties to sample or handle and a lack of expertise. This study gives an insight into the distribution and diversity of gelatinous species in the Southern South China Sea. Species composition, distribution and abundance of gelatinous zooplankton were investigated along the East Coast of Peninsular Malaysia. A total of 37 species were recorded from 10 locations along 4 transects at 5.10° N and 6.80° N extending from 103.2° E to 105.3° E in August 2016. Seven medusae, six siphonophores, four appendicularians, six chaetognaths, six salps, four doliolids and four pteropods were identified from the study area. Appendicularia with 201 ind/m3 was found to be the most dominant taxa recorded, followed by chaetognaths with 197 ind/m3. Scyphomedusae were the least represented group in the study, with an abundance of 8 ind/m3. Stations near the inshore region show higher abundance and diversity of gelatinous zooplankton compared to offshore regions. The evenness index between stations revealed that the gelatinous zooplankton were evenly distributed. According to Principal Component Analysis (PCA), the diversity and distribution of gelatinous zooplankton are driven by depth and temperature.
The application of Landsat imageries and mangrove vegetation index for monitoring mangrove community in Segara Anakan Lagoon, Cilacap, Central Java
Authors: Prayudha B , Siregar V , Ulumuddin Y I , Suyadi  , Prasetyo L B , Agus S B , Suyarso  , Anggraini K
Published: December 2021

The only place for estuarine-mangroves in Java Island, Segara Anakan Lagoon, experiences the vast decline of mangrove cover. Satellite remote sensing has a critical role in monitoring that change as it allows to record vast areas over time. However, most studies tend to utilize satellite data to investigate the change of mangrove areas into other land-use types rather than identify the mangrove community’s shifting. This study utilized the mangrove vegetation index (MVI) for monitoring the changes of mangrove communities at the life-form level using satellite data. The study used multi-temporal Landsat images as it has historical systematic archive data. The threshold value of the index for each class is defined by referring to the field data. The class referred to the life-form classification consisting of mangrove trees, Nypa, and understorey. The image analysis was conducted using Google Earth Engine (GEE), while R software was used for determining threshold values through statistical analysis. The result shows that the MVI can differentiate between some life forms of mangroves, with the overall accuracy reaching 78.79% and a kappa coefficient of 0.729. Further, the multi-temporal maps showed the decline of mangrove tree areas, which the understorey and Nypa community have replaced.
Suitability analysis of mangrove conversation areas in Mundu District, Cirebon Regency using Geographic Information Systems (GIS)
Authors: Akbar M R , Abimanyu A , Faid G M , Izza M Y N , As-syahiraand Z N , Febriani C
Published: December 2021

This study aims to analyze the suitability of mangrove conservation areas in the Mundu District, Cirebon Regency. In this study, we used Sentinel-2A satellite data obtained from ESA Copernicus’s web to analyze the normalized difference vegetation index (NDVI) of mangrove that will be used as a mangrove health indicator and several oceanographic characteristics to assess the suitability of mangrove conservation areas based on weighing-scores systems. All data were then analyzed using image processing combined with geographic information systems (GIS) tools available in the open-access QGIS software. Results show that the health of the mangrove based on vegetation index was in the range of 0.3–0.6. Mangroves in Mundu Region have consisted of two species,Avicennia marina, andRhizophora apiculata. The substrate in this area is dominated by muddy sand with a pH value of 8 and an average salinity of 32 PSU. The tidal type in Mundu region has mixed semi-diurnal characteristics with an average tidal height of 1.22 m. Based on those parameters and NDVI analysis, the suitability rank for mangrove conservation areas can be classified as suitable with a total score in the ranges of 101-200.
Spatial and temporal variability of satellite sea surface temperature in the Makassar Strait and the Java Sea
Authors: Syahdan M , Atmadipoera A S , Susilo S B , Lumban-Gaol J
Published: December 2021

Sea surface temperature (SST) data obtained from the Aqua-MODIS satellite from 2002 to 2012 were analyzed to determine the spatial and temporal variability in the key region of small pelagic fisheries between Makassar Strait and the Java Sea. Results of the Empirical Orthogonal Function (EOF) analysis show that the characteristics of this region are described by 60% based on the greatest contribution value respectively. The largest contribution of 52% shows that the SSTs in this region is warm. A strong indicator of these conditions appears in the east through the southern part of Kalimantan Island while the weak indicator is in the south to western part of Sulawesi Island. The temporal variation shows that the annual oscillation is dominant in this area where maximum SSTs occurs in the first transitional monsoon (April), while the minimum occurs in the southeast monsoon period (August). The influence of southeast monsoon formats the minimum SSTs area in the south of South Sulawesi that is generated by parallel wind-driven induces to the coast and the divergent current close to the coast. Due to inter-annual variability, minimum SSTs occurs before the El Nino episode whereas the maximum occurs before the La Nina event.
Internal solitary waves in the Northwest Sumatra Sea-Indonesia: from observation and modeling
Authors: Prasetya I A , Atmadipoera A S , Budhiman S , Nugroho U C
Published: December 2021

>The southern Andaman waters has been well known as one of the strongest generating and propagating area of internal solitary waves (ISWs), generated by semidiurnal barotropic tidal currents that impinge submarine ridge offshore western Weh. This study aims to investigate sea surface features of internal tides and tidal current around the submarine ridge and adjacent Weh-Aceh waters, derived from satellite imagery datasets (January-May 2018) and CROCO model-output datasets. The results show that sea surface signatures of ISWs are characterized by a strong radar signal backscattering of a dense ripple package in the generating area and two groups of ISWs arch in the propagating area, where the distance of the package groups and wavelengths vary 60-80 km and 9-163 km, respectively. Observed ISWs in March 2018 was 31. The satellite and model datasets suggest that generating area of internal waves is confined over the Breuh ridge. Here, the very strong semidiurnal (M2) barotropic tidal currents of 0.5-5.0 m/s are observed. During high-tide, amplified barotropic tidal currents acrossing the ridge flow partly southeastward into the Weh-Breuh passage. The model suggests that generating internal tidal waves over the ridge are manifested by strong vertical perturbation of isopycnal and current stratifications in the Lee-waves area.
Analysis of the relationship between chlorophyll-a and sea surface temperature on marine capture fisheries production in Indonesia: 2018
Authors: Ningsih W A L , Lestariningsih W A , Heltria S , Khaldun M H I
Published: December 2021

Fishery production in Indonesia is still relatively high, dominated by the marine capture fisheries. Oceanographic dynamics can affect the high and low levels of marine fishery production. Sea surface temperature and chlorophyll-a are oceanographic parameters that are often used as indicators for determining fishing areas, especially pelagic fish which are associated with ocean fertility. This study aims to identify the effect of chlorophyll-a and sea surface temperature (SST) on the production of fish catches in Indonesia: 2018. Data on marine capture fisheries production (skipjack, mackerel tuna, tuna and shrimp) in 2018 were obtained from the Ministry of Marine Affairs and Fisheries (KKP). Data of Chlorophyll-a and sea surface temperature (SST) are satellite observations from Marine Copernicus. The relationship between chlorophyll-a and sea surface temperature (SST) with marine capture fisheries production was analyzed using logistic regression analysis. The results showed that chlorophyll-a significantly affected the yield of skipjack and tuna in Indonesia with coefficients of -5.7066 and -4.3760, respectively. A higher concentration of chlorophyll-a had the possibility to produce high fish production of 0.0033 times than an area with a lower concentration of chlorophyll-a.
Turbulent mixing process in the Lombok Strait
Authors: Naulita Y , Natih N M N , Nabil
Published: December 2021

Turbulent mixing process in the Lombok Strait was evaluated from density inversions in CTD (Conductivity Temperature Depth) profiles obtained from the INSTANT (International Nusantara Stratification and Transport) recovery cruise, June 14-19th2005. The quality of the detected-overturn regions has been improved by applying wavelet denoising to CTD signals. The Thorpe analysis shows that many overturn regions less than 7 m were detected in throughout the water column of the Lombok Strait. Based on linear relationship between Thorpe Scale and Ozmidov Scale, the turbulent kinetic energy dissipation rate ε was estimated about 10−12−10−6W kg−1and density of eddy diffusivityKρ(10−6−10−2m2s−1). A relatively high ofKρØ (10−2m2s−1) was found at the southern part of the strait, near the sill which obstruct the Indonesian Thoughflow into the Indian Ocean. The dipped and rebounded isopycnal surfaces of σθ= 25.5–26.5 near the sill and the presence of strong shear at the same depth of the interval solitary wave (150 to 250 m) indicate that strong turbulence in this layer was driven by shear instability associated with breaking internal waves.
Broadband absorption of monolayer MoS2 in visible region using a tetramerized nanorod metasurface
Authors: Pei Yao , Sang Tian , Mi Qing , Wang Jicheng , Wang Yueke
Published: December 2021

High-efficient broadband absorption of the monolayer MoS2 is achieved by using a tetramerized nanorod metasurface (TNM), and the average absorption of 64.5% for the monolayer MoS2 can be obtained in the visible range of 400–750 nm. The unit cell of the TNM consists four Ag nanorods with different diameters, the incident light can be selectively absorbed by the monolayer MoS2 due to the magnetic resonance associated with the individual Ag nanorod, and broadband absorption of the monolayer MoS2 is realizable due to the cooperative magnetic resonances related to the tetramerized Ag nanorods. In addition, the absorption of the monolayer MoS2 is robust to the variation of the structural parameters, and it exhibits wide-angle and polarization-independent features.
NaYF4-based upconverting nanoparticles with optimized phosphonate coatings for chemical stability and viability of human endothelial cells
Authors: Lisjak Darja , Vozlič Maša , Kostiv Uliana , Horák Daniel , Majaron Boris , Kralj Slavko , Zajc Irena , Žiberna Lovro , Ponikvar-Svet Maja
Published: December 2021

The increasing interest in upconverting nanoparticles (UCNPs) in biodiagnostics and therapy fuels the development of biocompatible UCNPs platforms. UCNPs are typically nanocrystallites of rare-earth fluorides codoped with Yb3+ and Er3+ or Tm3+. The most studied UCNPs are based on NaYF4 but are not chemically stable in water. They dissolve significantly in the presence of phosphates. To prevent any adverse effects on the UCNPs induced by cellular phosphates, the surfaces of UCNPs must be made chemically inert and stable by suitable coatings. We studied the effect of various phosphonate coatings on chemical stability and in vitro cytotoxicity of the Yb3+,Er3+-codoped NaYF4 UCNPs in human endothelial cells obtained from cellular line Ea.hy926. Cell viability of endothelial cells was determined using the resazurin-based assay after the short-term (15 min), and long-term (24 h and 48 h) incubations with UCNPs dispersed in cell-culture medium. The coatings were obtained from tertaphosphonic acid (EDTMP), sodium alendronate and poly(ethylene glycol)-neridronate. Regardless of the coating conditions, 1 − 2 nm-thick amorphous surface layers were observed on the UCNPs with transmission electron microscopy. The upconversion fluorescence was measured in the dispersions of all UCNPs. Surafce quenching in aqueous suspensions of the UCNPs was reduced by the coatings. The dissolution degree of the UCNPs was determined from the concentration of dissolved fluoride measured with ion-selective electrode after the ageing of UCNPs in water, physiological buffer (i.e., phosphate-buffered saline—PBS) and cell-culture medium. The phosphonate coatings prepared at 80 °C significantly suppressed the dissolution of UCNPs in PBS while only minor dissolution of bare and coated UCNPs was measured in water and cell-culture medium. The viability of human endothelial cells was significantly reduced when incubated with UCNPs, but it increased with the improved chemical stability of UCNPs by the phosphonate coatings with negligible cytotoxicity when coated with EDTMP at 80 °C.
Wound healing properties of a fibrin-based dermal replacement scaffold
Authors: Brown Stuart J , Surti Farhana , Sibbons Paul , Hook Lilian
Published: December 2021

When serious cutaneous injury occurs, the innate wound healing process attempts to restore the skin’s appearance and function. Wound healing outcome is affected by factors such as contraction, revascularisation, regeneration versus fibrosis and re-epithelialisation and is also strongly influenced by the pattern and extent of damage to the dermal layer. Dermal replacement scaffolds have been designed to substitute for lost tissue, provide a structure to promote dermal regeneration, and aid skin grafting, resulting in a superior healing outcome. In this study the wound healing properties of a novel fibrin-alginate dermal scaffold were assessed in the porcine wound healing model and also compared to two widely used dermal scaffolds and grafting alone. The fibrin-alginate scaffold, unlike the other scaffolds tested, is not used in combination with an overlying skin graft. Fibrin scaffold treated wounds showed increased, sustained superficial blood flow and reduced contraction during early healing while showing comparable wound closure, re-epithelialisation and final wound outcome to other treatments. The increase in early wound vascularisation coupled with a decrease in contraction and no requirement for a skin graft suggest that the fibrin-based scaffold could provide an effective, distinctive treatment option to improve healing outcomes in human patients.
Analysis of anomalous transport based on radial fractional diffusion equation
Authors: WU Kaibang , WEI Lai , WANG Zhengxiong
Published: December 2021

Anomalous transport in magnetically confined plasmas is investigated by radial fractional transport equations. It is shown that for fractional transport models, hollow density profiles are formed and uphill transports can be observed regardless of whether the fractional diffusion coefficients (FDCs) are radially dependent or not. When a radially dependent FDC

D

α

r

<
1

is imposed, compared with the case under

D

α

r

=
1.0
,

it is observed that the position of the peak of the density profile is closer to the core. Further, it is found that when FDCs at the positions of source injections increase, the peak values of density profiles decrease. The non-local effect becomes significant as the order of fractional derivative

α
→
1

and causes the uphill transport. However, as

α
→
2
,

the fractional diffusion model returns to the standard model governed by Fick’s law.
Interaction between energetic-ions and internal kink modes in a weak shear tokamak plasma
Authors: ZHU Xiaolong , WANG Feng , CHEN Wei , WANG Zhengxiong
Published: December 2021

Based on the conventional tokamak HL-2A-like parameters and profiles, the linear properties and the nonlinear dynamics of non-resonant kink mode (NRK) and non-resonant fishbone instability (NRFB) in reversed shear tokamak plasmas are investigated by using the global hybrid kinetic-magnetohydrodynamic nonlinear code M3D-K. This work mainly focuses on the effect of passing energetic-ions on the NRK and NRFB instabilities, which is different from the previous works. It is demonstrated that the NRFB can be destabilized by the passing energetic-ions when the energetic-ion beta β
h exceeds a critical value. The transition from NRK to NRFB occurs when the energetic-ion beta β
h increases to above a critical value. The resonance condition responsible for the excitation of NRFB is interestingly found to be satisfied at ω
t + ω
p ≈ ω, where ω
t is the toroidal motion frequency, ω
p is the poloidal motion frequency and ω is the mode frequency. The nonlinear evolutions of NRFB’s mode structures and Poincaré plots are also analyzed in this work and it is found that the NRFB can induce evident energetic-ion loss/redistribution, which can degrade the performance of the plasmas. These findings are conducive to understanding the mechanisms of NRFB induced energetic-ion loss/redistribution through nonlinear wave-particle interaction.
Analytical study on discharge process of multiphase air-core pulsed alternators
Authors: Zhang Ying , Wen Xuhui , Li Wenchao , Wei Jialin , Zhang Xiaofeng , Wang Youlong
Published: December 2021

This paper has investigated the discharge process of a four-phase air-core pulsed alternator. A mathematical model of the short-circuit current, relating to firing angles of discharge thyristors and taking the current coupling and field current attenuation into account, is established. Compared with the conventional trial-and-error method and existing phase peak current model, the proposed model has considered the attenuation trend of the field current in the discharge process and derived the intuitive expression of the resultant short-circuit current. Firstly, the state equation model of a four-phase air-core pulsed alternator is established. Meanwhile, the simulation comparison indicates that the results of the state equation model are close to the finite-element model. Then, the segmented formula of resultant short-circuit current is derived based on the voltage equations of the armature winding circuits and the approximate attenuation coefficient of the field current. Finally, the segmented formula is verified with the finite-element method, and some preliminary experiments for field windings are carried out. The results show that this method can well describe the decay trend of field current and discharge current. It is helpful for selecting firing angles to generate the desired current amplitude and waveform in the future.
American poetry’s two characteristics
Authors: Caplan David
Published: December 2021

“American poetry’s two characteristics” explains the two characteristics which mark American poetry. On the one hand, several of its major figures promoted American poetry as essentially different from any other nation’s. Although the reasons they offer vary, they typically claim that American experience demands a different kind of expression. Such poets advocate for novelty, for a break with what is perceived to be outmoded and foreign. On the other hand, American poetry might be more rightly called profoundly transnational. American poetry often welcomes techniques, styles, and traditions originating from outside it. The two characteristics do not exist separately from each other. Rather, they work in a productive dialectic, inspiring both individual accomplishment and the broader field. Examples include Anne Bradstreet, Elizabeth Bishop, Wallace Stevens, and Langston Hughes.
Cognitive Benefits of Learning Additional Languages in Old Adulthood? Insights from an Intensive Longitudinal Intervention Study
Authors: Kliesch Maria , Pfenninger Simone E , Wieling Martijn , Stark Elisabeth , Meyer Martin
Published: December 2021

Second language (L2) learning has been promoted as a promising intervention to stave off age-related cognitive decline. While previous studies based on mean trends showed inconclusive results, this study is the first to investigate nonlinear cognitive trajectories across a 30-week training period. German-speaking older participants (aged 64–75 years) enrolled for a Spanish course, strategy game training (active control) or movie screenings (passive control). We assessed cognitive performance in working memory, alertness, divided attention, and verbal fluency on a weekly basis. Trajectories were modeled using Generalized Additive Mixed Models to account for temporally limited transfer effects and intra-individual variation in cognitive performance. Our results provide no evidence of cognitive improvement differing between the Spanish and either of the control groups during any phase of the training period. We did, however, observe an effect of baseline cognition, such that individuals with low cognitive baselines increased their performance more in the L2 group than comparable individuals in the control groups. We discuss these findings against the backdrop of the cognitive training literature and Complex Dynamic Systems Theory.
Cold winters have morph-specific effects on natal dispersal distance in a wild raptor
Authors: Passarotto Arianna , Morosinotto Chiara , Brommer Jon E , Aaltonen Esa , Ahola Kari , Karstinen Teuvo , Karell Patrik
Published: December 2021

Dispersal is a key process with crucial implications in spatial distribution, density, and genetic structure of species’ populations. Dispersal strategies can vary according to both individual and environmental features, but putative phenotype-by-environment interactions have rarely been accounted for. Melanin-based color polymorphism is a phenotypic trait associated with specific behavioral and physiological profiles and is, therefore, a good candidate trait to study dispersal tactics in different environments. Here, using a 40 years dataset of a population of color polymorphic tawny owls (Strix aluco), we investigated natal dispersal distance of recruiting gray and pheomelanic reddish-brown (hereafter brown) color morphs in relation to post-fledging winter temperature and individual characteristics. Because morphs are differently sensitive to cold winters, we predicted that morphs’ natal dispersal distances vary according to winter conditions. Winter temperature did not affect the proportion of brown (or gray) among recruits. We found that dispersal distances correlate with winter temperature in an opposite manner in the two morphs. Although the gray morph undertakes larger movements in harsher conditions, likely because it copes better with winter severity, the brown morph disperses shorter distances when winters are harsher. We discuss this morph-specific natal dispersal pattern in the context of competition for territories between morphs and in terms of costs and benefits of these alternative strategies. Our results stress the importance of considering the interaction between phenotype and environment to fully disentangle dispersal movement patterns and provide further evidence that climate affects the behavior and local distribution of this species.