bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of Faults in Power Transformers Based on Oil Chromatographic Analysis in the Coastal Zone
Authors: Collazos Camilo , Arroyo Victor , Chauca Mario , Ramos Javier , Morales Jose , Cuba Roberto
Published: July 2022

The purpose of this research work is to predict failures in power transformers based on oil chromatographic analysis and thus improve their reliability and avoid further deterioration of equipment and untimely service outages. The research is basic, descriptive, correlational level, and an experimental design. The sample consisted of 3 transformers corresponding to a company in charge of the distribution of electrical energy in the coastal area of Peru, different techniques were used such as the characteristic gas methods, from Dornemburg, from the Rogers relationships, from the total gases fuels. From the analysis of these samples, the gas content presented by the transformers was related to the faults presented by the equipment. The values found were compared with the maximum levels allowed using the key gas method. In this way, they were related to the conditions and the possible causes of breakdowns that could occur. We conclude that gas chromatography analyzes the oil that is composed of elements that make up the insulation of a transformer of many hydrocarbon bases comprised of between 16 and 22 carbon atoms, in addition to cellulose, which is a polymeric hydrocarbon that decomposes and releases gases when a thermal or electrical fault occurs.
Designing MPC Controller for a Heat Exchanger Equipped with Thermoelectric Generators
Authors: Kemjariya Sucha , Daosud Wachira , Weerachaipichasgul Weerawun , Kittisupakorn Paisan
Published: July 2022

A thermoelectric generator (TEG) is a solid-state semiconductor device that can convert temperature differences and heat flow into electrical energy. Nowadays, industries with high-temperature production processes tend to experience unavoidable heat loss. Heat exchangers are therefore the most widely used equipment to recover these waste heat. The researcher therefore saw the benefits of bringing TEG devices to be installed in heat exchangers. It is thought that in addition to the heat exchanger being a device that helps the heat transfer of one fluid to another fluid. Can also generate electricity back to use as well. This will be of great benefit in increasing the efficiency of waste heat recovery and reducing production costs. In this research, 36 plates of Bismuth Telluride (Bi2Te3) TEG devices were installed in plate and fin heat exchangers and studied the effect of changes in the inlet flow rate of cold water at 20 °C on the effect of heat exchange and the electrical power produced by TEG. The hot water inlet flow rate was constant at 1 l/min and the temperature was constant at 85 °C. Then mathematical model was created to predict the results of the outlet hot water temperature, outlet cold water temperature, current and voltage produced. The model can predict accurately the least squares value (R2) with values of 0.949, 0.859, 0.707 and 0.749, respectively. In addition, a multiple input, multiple output (MIMO) using model predictive controller (MPC) was designed to control the output current, and temperature can control into the setpoint effectively.
A Study of Large Sheave Counter-Roller Spinning Force
Authors: Zhu Chengcheng , Li Fan , Meng Dean , Dong Yuanzhe
Published: July 2022

In this paper, a counter-roller spinning method is presented, which is designed to produce relatively thin-walled large sheaves. The large sheave counter-roller spinning force is poorly studied. And the forming forces have a significant influence on industrial applications. Herein, theoretical analysis and numerical simulation methods were utilized to explore the large sheave counter-roller spinning process and spinning force. Anisotropy of the material was considered by the Hill-48 anisotropic yield criterion. Numerical simulation has been demonstrated to correspond to experimental values. The spinning forces in the simulation and experiment matched well and steadily increased throughout the process. The roller and mandrel have similar spinning forces, and the radial spinning force is much larger than other forces. Finally, a theoretical model to compute the spinning force was constructed.
Design and Application of Automobile Intelligent Instrument Panel Interface
Authors: Zhang Caizhong
Published: July 2022

This article first investigates the functions and styles of automotive dashboards on the market, and summarizes some of the existing problems and user pain points. Combining emerging technologies and user needs, analyze the functions and technologies that are helpful to the driver, thereby improving the safety of the driver’s operation. This research uses the user-centered design concept and explores the intelligent and humanized dashboard design to replace the display of the car’s central control screen. The dashboard adopts an innovative form that combines a steering wheel and a game handle, which gives it a sense of technology and speed, and improves the safety and cognition of users.
The BIM Lifecycle Management of Manufacturing Cultural Heritage Projects
Authors: Lin Kaixin , Long Yongzhuo , Chen Boke , Chen Simin , Luo Zhihua
Published: July 2022

As a popular cultural heritage in China, the Lingnan architecture is increasingly adopting prefabricated construction to meet the growing need in building projects exhibiting the unique culture of the region, which can be enhanced by BIM technology. As most BIM related research focuses on particular phases of a project, there lacks of a study on the BIM lifecycle management, particularly on manufacturing cultural heritage projects. Hence, this research analogizes the BIM lifecycle management to the evolution of biological agents, and constructs the self-organizing relationship complex of BIM application key items and BIM application technology prototype, taking this as the cornerstone to develop a lifecycle BIM management framework and form an operation theory for manufactured heritage buildings, which are verified through a case study.
Some Generalizations of Random Broken and Pick-up Stick Problems
Authors: Liu Yucheng , Wang Zhichao
Published: July 2022

We consider sticks with random lengths, which are further randomly broken into several pieces. The probability that these sticks can form a polygon is computed in this article. This Broken Pick-up Stick Problem was first asked in [1] and we give a general formula to solve this problem. Besides, we study the probability that any three sticks with independent and uniformly distributed lengths can form a triangle. Our results generalize the famous Spaghetti Problem and the Pick-up Stick Problem in probability. We present a way to transfer these continuous probability problems into discrete problems and apply combinatorial methods to address the discrete version of the problems.
Application of the Chimera Method to Poisson’s Equation with the Homogeneous Dirichlet Boundary Condition
Authors: Chien Henry , Fan Yupeng , Zeng Ziyun
Published: July 2022

Establishing variational formulation is an effective way to study the existence and uniqueness of the solution of certain elliptic partial differential equation with boundary condition. For the solution of certain elliptic partial differential equation with boundary condition, we know that the numerical solution obtained by the finite element method approximates the solution of this equation. Moreover, to avoid gridding overly complex domains, we can use the Chimera method to decompose the domain into several overlapping sub-domains. In this paper, we study Poisson’s equation with the homogeneous Dirichlet boundary condition. By analyzing the existence and uniqueness of the solution of the corresponding variational formulation, we know the existence and uniqueness of the solution of Poisson’s equation with the homogeneous Dirichlet boundary condition. We use the Chimera method and the finite element method to deal with Poisson’s equation with the homogeneous Dirichlet boundary condition by constructing two iterative sequences and analyzing their properties.
Application of WKB Method in Approximating Wave Functions in Square Potential Wells
Authors: Guo Haohui
Published: July 2022

This paper introduces a widely used approximation method, the Wentzel-Kramers-Brillouin (WKB) method, for solving the Schrodinger equation, sets up a theoretical framework to derive the general solutions of the method, and carries out the application of the approximation method in specific cases to verify the validity and practicality of the method. Throughout the study, numerical methods, such as the Simpsons method, and programming tools, such as Python, are used to process sophisticated calculations. The final approximated solutions for the Schrodinger equation are able to demonstrate the state of a particle in an isolated quantum system. All the presented studies are based upon the knowledge and skillsets of a high school student.
Drug Level Modelling with Difference and Differential Equations
Authors: D’Cunha Shilpa , Lakshmi Gorty V R
Published: July 2022

In the current study, drug level in the human body is studied using mathematical modelling, where the difference equations have been used as a means of analyzing the dosage over a prescribed time, reduction in dose half-life, and the total amount of residual drug in the blood-stream for a given time-period. Further, the differential equations approach is investigated for data fitting using Mathematica to extend the application adhering to the continuous nature of the inherent function. The perspective helps to preserve critical resources and render comparative results. In this approach, zero-order, first-order, and fractional order kinetics are explored and compared.
Numerical Simulation Study and Analysis of Water Inrush from Floor Concealed Subsidence Column during Mining
Authors: Wei Fu
Published: July 2022

In order to clarify the role of mining on the surrounding rock failure and water inrush of the karst collapse column in the working face floor, the concealed karst collapse column in the floor of Geting Coal Mine is taken as the research object, and the FLAC3D numerical simulation software is used to analyze the mining process. The stress field in the vertical direction, the plastic failure zone and the displacement change in the vertical direction are analyzed and studied, and the water inrush process of the hidden floor karst collapse column under different advancing distances is analyzed. The research results show that with the continuous increase of the advancing distance, the plastic failure range of the karst collapse column continues to increase, and the vertical displacement of the floor continues to increase. When the plastic failure zone of the coal floor and the plastic failure zone of the karst collapse column are connected, Water inrush accidents from the karst collapse column of the floor are prone to occur.
Simulation of Meshing of Herringbone Double Circular-Arc Helical Gears using Multibody Dynamic Analysis Software
Authors: Lee C K , Hsieh C L , Ruan J C , Wang C Y
Published: July 2022

This paper aims to complete the simulation of meshing of a pair of herringbone double circular-arc helical gears by using the multibody dynamic analysis software, SolidWorks motion. Three types of edge modifications, including no edge modification, chamfered edge modification, and rounded edge modification, are applied respectively to the pair of gears. The output angular velocities and contact regions corresponding with the three types of edge modifications are analyzed. Moreover, whether the center distance assembly error affects the output angular velocity and contact regions are analyzed. The results obtained by the simulation of meshing show that rounded edge modification is better than chamfered edge modification, and chamfered edge modification is better than no edge modification. The center distance assembly error has no effect on the output angular velocity and has little effect on the contact regions. Therefore, double circular-arc helical gears are not sensitive to center distance assembly errors.
A Hybridizable Discontinuous Galerkin and Boundary Element coupling method for electromagnetic simulations
Authors: Kong Yan , Yan Mei
Published: July 2022

In this paper, the hybridizable discontinuous Galerkin (HDG) method is combined with the electric field integral equation (EFIE) for the numerical simulation of time-harmonic Maxwell’s equation. The key feature of HDG-EFIE is that the HDG method and the boundary element method (BEM) can be coupled naturally through the extra hybrid variable on the faces of elements, the combined method produces a linear system in term of the degrees of freedom of the extra hybrid variable only. A numerical solution was compared to the analytical solution and found to be in excellent agreement.
A Short Review of Deep Tissue Imaging Techniques and Applications
Authors: Song J , Dean Z
Published: July 2022

Deep tissue imaging is a fundamental research method in the field of biological imaging. With an intent on obtaining more clear and detailed images deep within tissue, researchers have put much focus on developing deep tissue imaging techniques. In the past few decades, deep tissue imaging techniques have been improved in many aspects. In contrast to increasingly refined techniques, the application of these techniques seems to have not received equally attention. In this review, we will focus on the advanced applications of deep issue imaging that have emerged in recent years.
Reconstruction, Analysis of the Process ggH Decay to llνν Monte Carlo with MH=125 GeV and Introduction of the Physical Background
Authors: Zeng Fanli , Liu Yiwei , Ouyang Ze , Wu Bolin , Zhang Jingyuan
Published: July 2022

This paper outlines analysis the process gg → H → WW → llνν Monte Carlo, collision events with MH=125GeV. The discovery of the Higgs boson perfected the standard model and proposed more processes of the production, decay of the Higgs and the Higgs Mechanism. In this analysis, ggH process is reconstructed. Analyzed and calculated the probability of decay WW pairs as productions of decay process. Simulated Monte Carlo signal samples and background are compared to data from Atlas.
Research on Physical Laws Behind Irreversible Cartesian Diver
Authors: Zhang Wantong , Wu Zhe
Published: July 2022

The float-sink is an instrument used to demonstrate the pressure transmission of liquids, and it is a vivid proof of Archimedes's principle and Pascal's principle. When pressure is applied to the container in which the sinker is located, the sinker sinks; when the pressure is released, the sinker floats up. This phenomenon qualitatively proves Archimedes's law. But when the sinker sinks to a certain critical depth, even if the pressure is released, the sinker will no longer float up. This phenomenon is the so-called "irreversible sinker". This article mainly analyzes the irreversible principle and influencing factors when the float-sink reaches the critical depth and explores the influence of different influencing factors on the critical depth through mathematical analysis and experimental methods. Finally, it is concluded that the critical depth when the float is irreversible is related to factors such as the mass of the float, the volume of gas in the float and the height of the water in the container, and the critical depth has a linear relationship with the mass of the float.
Observing the Development of Two Solar Flares by Monitoring AR 12882 which Produces a Kp6 Geomagnetic Storm in October 2021
Authors: Rossdee Anis , Shariff N N M
Published: July 2022

In this paper, we study active region 12882 in conjunction with the level of geomagnetic storm based on space weather data. Several flares occurred in this region in October 2021, including M1.6 and C2.1. Data were also collected from the online solar monitor and space weather live database provided by NOAA and SDO/AIA. The study of the solar flare events was done by monitoring the sunspot region for the past four days to observed changes in the earth’s atmosphere. The M-class flare event made by AR 12882 produced a CME with a speed exceeding 500 km/sec which directed towards Earth and produced an intense geomagnetic storm with kp6 index.
Research on the Galaxy Rotation Model based on 21 cm Hydrogen Spectrum
Authors: Jia Ruopeng
Published: July 2022

Glon sky survey is a data acquisition method of 21 cm neutral hydrogen spectrum. Recently, the author has conducted a series of studies on the data of the gLon sky survey. After transforming and analyzing the data, the author found that in the region of the center of the Milky Way galaxy, the linear velocity of galactic rotation increases with the distance away from the center. For the region 15 light-years away, the linear velocity of rotation remains almost unchanged. By transforming the variation of velocity with radius into the chart, it can be found that there are deviations in the early galactic rotation structure model. For the newly proposed combined Exponential and Isothermal model, there is a high degree of agreement. The model confirms that there is a huge dark matter halo at the outer edge of the Galaxy. The weak gravitational interaction between dark matter halo and visible matter affects the current rotational structure of the Galaxy.
Structural Design for Improving the Strength of Flat Wooden Pallets
Authors: Zhu X , Toyota H , Ito D , Doi K
Published: July 2022

The purpose of this study is to develop a new pallet structure using the inexpensive hinoki wood, which is produced in the Ehime Prefecture, having the same strength as the conventional Oregon pine wood. A new pallet structure was proposed for achieving high-strength by improving the flexural stiffness and compressive stiffness and achieving high-cost performance by using the inexpensive hinoki wood. The results obtained in this study are summarized as follows: deflection of the new type is reduced compared to the standard type, due to the increased bending rigidity of the edge board and deck board; compressive displacement of the new model decreases, as the compressive stiffness of the pallet legs increases; new mold pattern 6 made is higher in strength and rigidity than the standard mold; cost of the new type #6 is 72% of that of the standard type pallet, and cost can be reduced by 28%.
Trials of transmission imaging using clinically used Ir-192 source for high-dose-rate brachytherapy
Authors: Nagata J. , Yamamoto S. , Nakanishi K. , Noguchi Y. , Okudaira K. , Kataoka J.
Published: July 2022

In high-dose-rate (HDR) brachytherapy, verification of an
Ir-192 source's position during treatment is required. One of the
methods for this used a high-energy pinhole gamma camera to image
the position of the source, but the absolute position of the source
cannot be measured. To confirm the absolute position, it will be
useful to acquire the transmission image of a subject in addition to
the gamma photon image at the same time without using an additional
X-ray system. To measure the transmission images, we tried to use
the high-energy gamma photons emitted from the Ir-192 source used
for the therapy. We developed a high-energy gamma photon imaging
system composed of 1-mm-thick Pr doped Gd2O2S (GOS), a
surface mirror, and a cooled charge-coupled device (CCD) camera. The
developed imaging system achieved transmission imaging of
high-energy gamma photons by transporting the Ir-192 source in front
of the imaging system. The spatial resolution of the imaging system
was better than 2.4 mm FWHM with and without a 10-cm-thick acrylic
block set between the imaging system and the source. Moderate
spatial resolution and contrast images of phantoms were obtained
with the system. For the dynamic imaging mode, continuous images of
the phantoms were measured with 1-sec intervals. There was no
observable difference in the transmission images by the movement of
the Ir-192 source. Transmission imaging of subjects using an Ir-192
source for HDR brachytherapy could be achieved using our developed
imaging system. The system offers a new method to measure the
real-time transmission images of the subject during HDR
brachytherapy.
Comparative study on charging-up of single, double and triple Gas Electron Multipliers (GEM)
Authors: Kumar V. , Mukhopadhyay S. , Majumdar N. , Sarkar S.
Published: July 2022

In this paper, a detailed investigation has been carried out to understand the physics behind GEM charging-up and its effects on gain. Experiments have been performed on both double and triple GEM with the help of 55Fe X-ray source and a comparative study of these configurations along with the single GEM results observed in our previous work has been reported.
The increase in gain due to polarization of GEM foil dielectric and reduction in gain due to charge accumulation on dielectric are studied for various field configurations and different radiation intensities.
Timing performance of the Timepix4 front-end
Authors: Heijhoff K. , Akiba K. , Ballabriga R. , van Beuzekom M. , Campbell M. , Colijn A.P. , Fransen M. , Geertsema R. , Gromov V. , Llopart Cudie X.
Published: July 2022

A characterisation of the Timepix4 pixel front-end with a
strong focus on timing performance is presented. Externally
generated test pulses were used to probe the per-pixel
time-to-digital converter (TDC) and measure the time-bin sizes by
precisely controlling the test-pulse arrival time in steps of
10 ps. The results indicate that the TDC can achieve a time
resolution of 60 ps, provided that a calibration is performed to
compensate for frequency variation in the voltage controlled
oscillators of the pixel TDCs. The internal clock distribution
system of Timepix4 was used to control the arrival time of
internally generated analog test pulses in steps of about
20 ps. The analog test pulse mechanism injects a controlled amount
of charge directly into the analog front-end (AFE) of the pixel, and
was used to measure the time resolution as a function of signal
charge, independently of the TDC. It was shown that for the default
configuration, the AFE time resolution in the hole-collecting mode
is limited to 105 ps. However, this can be improved up to about
60 ps by increasing the preamplifier bias-current at the cost of
increased power dissipation. For the electron-collecting mode, an
AFE time resolution of 47 ps was measured for a bare Timepix4
device at a signal charge of 21 ke. It was observed that additional
input capacitance from a bonded sensor reduces this figure to
62 ps.
Energetic neutron identification with pulse shape discrimination in pure CsI crystals
Authors: Longo S. , Khan M. , Dharani S. , von Krosigk B. , Ferber T.
Published: July 2022

Pulse shape discrimination with pure CsI scintillators is
investigated as a method for separating energy deposits by energetic
neutrons and photons at particle physics experiments. Using neutron
data collected near the European XFEL XS1 beam window the pulse
shape discrimination capabilities of pure CsI are studied and
compared to CsI(Tl) using near-identical detector setups, which were
operated in parallel. The inelastic interactions of 100 MeV
neutrons are observed to produce a slower scintillation emission in
pure CsI relative to energy deposits from cosmic muons. By
employing a charge-ratio method for pulse shape characterization,
pulse shape discrimination with pure CsI is shown to be effective
for identifying energy deposits from neutrons vs. cosmic muons,
however, pure CsI was not able resolve the specific type of neutron
inelastic interactions as can be done with CsI(Tl). Using pulse
shape discrimination, the rate of energetic neutron interactions in
a pure CsI detector is measured as a function of time and shown to
be correlated with the European XFEL beam power. The results
demonstrate that pulse shape discrimination with pure CsI has
significant potential to improve electromagnetic vs. hadronic
shower identification at future particle physics experiments.
Grid-based simulation of soil moisture in the UK: future changes in extremes and wetting and drying dates
Authors: Kay A L , Lane R A , Bell V A
Published: July 2022

Soil moisture, typically defined as the amount of water in the unsaturated soil layer, is a central component of the hydrological cycle. The potential impacts of climate change on soil moisture have been less specifically studied than those on river flows, despite soil moisture deficits/excesses being a factor in a range of natural hazards, as well as having obvious importance for agriculture. Here, 1 km grids of monthly mean soil moisture content are simulated using a national-scale grid-based hydrological model, more typically applied to look at changes in river flows across Britain. A comparison of the soil moisture estimates from an observation-based simulation, with soil moisture deficit data from an operational system developed by the UK Met Office (Meteorological Office Rainfall and Evaporation Calculation System; MORECS), shows relatively good correspondence in soil drying and wetting dates, and in the month when soils are driest. The UK Climate Projections 2018 Regional projections are then used to drive the hydrological model, to investigate changes in occurrence of indicative soil moisture extremes and changes in typical wetting and drying dates of soils across the country. Analyses comparing baseline (December 1981–November 2011) and future (December 2050–November 2080) time-slices suggest large increases in the spatial occurrence of low soil moisture levels, along with later soil wetting dates, although changes to soil drying dates are less clear. Such information on potential future changes in soil moisture is important to enable the development of appropriate adaptation strategies for a range of sectors vulnerable to soil moisture levels.
In situ conservation of mangroves species in Bagan Datuk, Perak
Authors: Nurcahaya Khairany M A , Farah Shahanim M M , Zahirah M T
Published: July 2022

In situ conservation is one of the methods recommended for conserving forest genetic resources. It aims to maintain and recover viable population of species in its natural habitat, to reintroduce the rare and endangered species and to recreate the habitats for plant species. Though mangrove rehabilitation programmes are widely carried out in Malaysia, the most common species planted for this purpose have always been Rhizophora apiculata (Bakau minyak) and Rhizophora mucronata (Bakau kurap). In this study, mangroves species namely Bruguiera cylindrica (Berus-berus), Ceriops tagal (Tengar), Xylocarpus granantum (Nyireh bunga), Xylocarpus moluccensis (Nyireh batu) and Sonneratia ovata (Gedabu) were planted in Bagan Datuk Mangrove Germplasm, Perak. These species were selected due to their unavailability in the study area. The main objective of this study is to rehabilitate and to introduce new species in the Bagan Datuk Mangrove Germplasm area. The initial growth and survival of saplings planted were measured and data obtained were analyzed using SPSS program. After 12 months of planting, the survival rate was 80% and Sonneratia ovata recorded the highest mean height increment.
Research notes on bats’ species assemblage in Madai Cave of Segama Valley, Sabah, Malaysia
Authors: Mahyudin A , Sukiman S S , Kumar S V , Hoque M Z
Published: July 2022

Insectivorous bats spend approximately half of their lives in the roost. Most of them are cave-dwelling and use the caves as roosting grounds. Roosts are important for mating, hibernation, rearing young, and a place to socialise, while providing protection from predators in a thermo-stable environment. This study aims to assess the diversity of insectivorous bats at Madai caves in Kunak, Lahad Datu, Sabah over a temporal period of 8 years. The sampling of bats was conducted twice i.e. in August 2010 and in December 2018. Harp traps and mist nets were used to sample bats in all sampling sessions. Eighteen species of bats, including two fruit bats, Cynopterus brachyotis and Rousettus spinalatus, were identified from the study site. Four insectivorous bat species were found in both years consistently i.e. Hipposideros cervinus, Rhinolophus creaghi, R. philippinensis, and Chaerephon plicatus. The species list in 2010 and 2018 differed by more than 50%, which may be a cause of concern and warrants further investigation. Most of the listed species are categorised as Least Concern, under the IUCN Red List of Threatened Species, except for Rousettus spinalatus, Hipposideros ridleyi and Miniopterus schreibersii which are listed as vulnerable. Only Hipposideros dyacorum is protected under Sabah Wildlife Enactment (1997). These findings will assist policymakers in making decisions on the importance to conserve the natural habitats of bats.
Selection of agroforestry tree-base participatory and ecological approach in Central Kalimantan, Indonesia
Authors: Purnawan E I , Jemi R , Kasim H , Uthan L A , Regalino J , Hamidi A
Published: July 2022

This study investigates the selection agroforestry tree species based on a participatory approach and an ecological approach in Humbang Raya village and Tumbang Mantuhe village. This study method was carried out using a participatory approach through Focus Group Discussion (FGD) activities and an ecological approach through the identification of tree species in open and closed forests. The results of the FGD selected tree species in Humbang Raya village as many as 17 tree species and in Tumbang Mantuhe village as many as five tree species. The results of the identification of tree species in Humbang Raya village in closed forest amounted to 34 tree species, while in open forest there were 10 tree species. In Tumbang Mantuhe village in closed forest there are 29 species of trees and open forest five species of trees. It was concluded that the selected tree species to be planted on agroforestry land in Humbang Raya village and Tumbang Mantuhe village each had 4 tree species.
Vertical accuracy comparison of multi-source Digital Elevation Model (DEM) with Airborne Light Detection and Ranging (LiDAR)
Authors: Chai L T , Wong C J , James D , Loh H Y , Liew J J F , Wong W V C , Phua M H
Published: July 2022

Digital Elevation Model (DEM) is a digital representation of ground surface topography or terrain. There are many freely available DEM data with a spatial resolution of 30 m to 90 m. Nevertheless, their vertical accuracy may vary, depending on the vegetation cover and terrain characteristics. This study examined the vertical accuracy of open-access global DEMs (ALOS PALSAR, ASTER GDEM3, SRTM, TanDEM-X) and fused DEM (EarthEnv-DEM90, MERIT DEM). Their performances were assessed using a Digital Terrain Model (DTM) generated using airborne LiDAR data that had an outstanding absolute vertical accuracy (mean error (ME) = 0.24 m; root mean square error (RMSEz) = 1.20 m). Height differences between the global DEMs and the LiDAR DTM were calculated and examined their performances by forested vs. non-forested, slope, and elevation classes. The results showed the MERIT DEM was superior to other DEMs in most of the testing methods. It outperformed other DEMs with an RMSEz value of 3.02 m in the forested areas, followed by ALOS PALSAR (9.29 m), EarthEnv-DEM90 (9.40 m), SRTM (9.80 m), TanDEM-X (10.41 m), and ASTER GDEM3 (12.57 m). The MERIT DEM also had the best accuracy in the higher elevation areas. Overall, the ASTER GDEM3 had the worst accuracies, with relatively large over-estimations compared to other DEMs. Despite its low spatial resolution, the MERIT DEM was the best for representing terrain elevation for applications over a large area.
Utilizing Landsat 8 OLI for land cover classification in plantations area
Authors: Anua S N , Wong W V C
Published: July 2022

Identifying the land cover in plantations is crucial to assist the management of an area. Today, land cover classification can be achieved using free satellite data. The objective of this study is to perform a supervised classification using LANDSAT 8 OLI to differentiate the land cover in Brumas Camp which consists of non-vegetation, oil palm, forest, and forest plantations. The overall accuracy and Kappa’s coefficients were 71.64% and 0.62, respectively. We found out that the accuracy of classification for non-vegetation is relatively higher compared to vegetation land cover types. The non-vegetation land cover has distinct spectral reflectance which is useful to differentiate between non-vegetation and vegetation land covers.
Correlation between hardness and density profile of glue-laminated timber manufactured from viscoelastic-thermal compression modified Paraserianthes falcataria laminas
Authors: Albert C M , Liew K C
Published: July 2022

A fast-growing tree species, Paraserianthes falcataria, possessed low value in density. Therefore, it was subjected to a densification treatment, i.e., viscoelastic-thermal compression (VTC), to enhance its density and mechanical performance. The objective of this study was to investigate the correlation between the density profile and hardness of VTC-modified glue-laminated timber. The laminas underwent VTC, whereby five different pre-steaming durations were applied, ranging from 0-30 minutes prior to forming into glue-laminated timber panels. The panels were cut into pre-determined test pieces and subjected to density determination using an X-ray densitometer and hardness test in the tangential direction using the ball indentation method. The correlation analysis found that increasing density slightly enhanced the hardness of the tangential surface of the glue-laminated timber test pieces, whereby the Pearson’s correlation values, r were .074 (0 minutes, non-densified), .154 (0 minutes, densified), -.027 (10 minutes, densified), .088 (20 minutes, densified), and .225 (30 minutes, densified). Nevertheless, the associations were found to be statistically insignificant because the p-values were greater than 0.05, thus suggesting densification treatment did not enhance hardness.
Morphological and bending properties of cross-laminated timber prototype manufactured with densified Paraserianthes falcataria
Authors: Tan Y F , Liew K C
Published: July 2022

Densification is a modification process commonly used to modify the density and hence, properties improvement of low-density wood. Cross-laminated timber (CLT) manufactured from plantation tree has gained more interest recently but the potentiality of using densified fast-grown plantation wood, Batai (Paraserianthes falcataria) in the layering of CLT has yet to be discovered. This study aims to investigate the relationship between morphology of densified wood and bending performance of lab-scale prototype CLT manufactured from it. Laminas after conditioned were hot-pressed (105°C, 6 MPa for 10 minutes) for two stages with venting (press released for 1 minute 40 seconds) in between before cooling to below 100°C to reduce immediate springback. Densified laminas with three different targeted thicknesses (8, 10, and 15) mm were produced before further manufactured into three-layer CLT (24, 30, and 45) mm thick panels. CLT 60 mm thick panels from three pieces of undensified (20 mm) laminas acts as control. Results show that area of pores morphologically had reduced significantly (average 6.59 µm2) for laminas densified to 8 mm. CLT 24 show significant improvement up to 696% (Modulus of Elasticity) and 48.8% (Modulus of Rupture) when the area of pores had reduced. Morphological of densified laminas correlates negatively with bending properties of CLT.
Wear life of PTFE/Kevlar self-lubricating composite under high frequency oscillatory conditions
Authors: Jian Liu , Jialun Li , Fei Lu , Yongzhen Zhang
Published: July 2022

In this study, the PTFE/Kevlar self-lubricating composite was prepared for the service conditions of high frequency oscillation. The full-life cycle friction and wear characteristics was analyzed, and the tribological properties and failure mechanism at different life stages were studied. Fatigue life test of PTFE/Kevlar self-lubricating composite was performed by a self-developed heavy load reciprocating test machine. Results show that the self-lubricating performance of the material increases while the wear life decreases with the increase of stress and frequency. The main failure mode of the material consists of abrasive wear and adhesive wear, accompanied by extrusion fracture of the fiber. Tribological performance and surface state show distinct phase characteristics in the life cycle. The change of frequency affects the adhesive wear degree in the fiber fracture area. Differently, the change of stress affects the adhesive wear degree in the fiber fracture area as well as the uniform stability of the transfer film. The comparison of frequency and stress shows that the change of frequency has a greater influence on the material self-lubricating performance and life. This study could provide a research basis for the design and development of self-lubricating composites in high frequency oscillating conditions, and also provide reference data for the calibration of service conditions for PTFE/Kevlar self-lubricating composites.
The FMRFamide-like peptide FLP-2 is involved in the modulation of larval development and adult lifespan by regulating the secretion of the insulin-like peptide INS-35 in Caenorhabditis elegans
Authors: Kageyama Natsumi , Nose Masayo , Ono Masahiro , Matsunaga Yohei , Iwasaki Takashi , Kawano Tsuyoshi
Published: July 2022

In the animal kingdom, neuropeptides regulate diverse physiological functions. In invertebrates, FMRFamide and its related peptides, a family of neuropeptides, play an important role as neurotransmitters. The FMRFamide-like peptides (FLPs) are one of the most diverse neuropeptide families and are conserved in nematodes. Our screen for flp genes of the free-living soil nematode Caenorhabditis elegans revealed that the flp-2 gene is involved in the larval development. The gene is also conserved in plant-parasitic root-knot nematodes. Our molecular genetic analyses of the C. elegans flp-2 gene demonstrated as follows: (1) the production and secretion of FLP-2, produced in the head neurons, are controlled by environmental factors (growth density and food); (2) the FLP-2 is involved in not only larval development but also adult lifespan by regulating the secretion of one of the insulin-like peptides INS-35, produced in the intestine. These findings provide new insight into the development of new nematicides.
Studying predator foraging mode and hunting success at the individual level with an online videogame
Authors: Fraser Franco Maxime , Santostefano Francesca , Kelly Clint D , Montiglio Pierre-Olivier
Published: July 2022

Predator–prey interactions are important drivers of community and ecosystem dynamics. With an online multiplayer videogame, we propose a novel system to explore within population variation in predator hunting mode, and how predator–prey behavioral interactions affect predator hunting success. We empirically examined how four predator foraging behaviors covary at three hierarchical levels (among environments, among individuals, and within individuals) to assess the structure of predator hunting mode. We also investigated how prey activity affects the foraging behavior and hunting success of predators. Our study supports key findings on predator foraging mode and predator-prey interactions from behavioral ecology. We found that individual predators displayed a diversity of hunting tactics that were conditioned by prey behavior. With prey movement, individual predators specialized either as cursorial or ambush hunters along a continuum of their hunting traits, but also shifted their strategy between encounters. Both types of hunters were generally better against slower moving prey, and they achieved similar prey captures over the sampling period. This suggests that virtual worlds supporting multiplayer online videogames can serve as legitimate systems to advance our knowledge on predator–prey interactions.
Failed despots and the equitable distribution of fitness in a subsidized species
Authors: Brunk Kristin M , West Elena H , Peery M Zachariah , Pidgeon Anna
Published: July 2022

Territorial species are often predicted to adhere to an ideal despotic distribution and under-match local food resources, meaning that individuals in high-quality habitat achieve higher fitness than those in low-quality habitat. However, conditions such as high density, territory compression, and frequent territorial disputes in high-quality habitat are expected to cause habitat quality to decline as population density increases and, instead, promote resource matching. We studied a highly human-subsidized and under-matched population of Steller’s jays (Cyanocitta stelleri) to determine how under-matching is maintained despite high densities, compressed territories, and frequent agonistic behaviors, which should promote resource matching. We examined the distribution of fitness among individuals in high-quality, subsidized habitat, by categorizing jays into dominance classes and characterizing individual consumption of human food, body condition, fecundity, and core area size and spatial distribution. Individuals of all dominance classes consumed similar amounts of human food and had similar body condition and fecundity. However, the most dominant individuals maintained smaller core areas that had greater overlap with subsidized habitat than those of subordinates. Thus, we found that (1) jays attain high densities in subsidized areas because dominant individuals do not exclude subordinates from human food subsidies and (2) jay densities do not reach the level necessary to facilitate resource matching because dominant individuals monopolize space in subsidized areas. Our results suggest that human-modified landscapes may decouple dominance from fitness and that incomplete exclusion of subordinates may be a common mechanism underpinning high densities and creating source populations of synanthropic species in subsidized environments.
HiC-TE: a computational pipeline for Hi-C data analysis to study the role of repeat family interactions in the genome 3D organization
Authors: Lexa Matej , Cechova Monika , Nguyen Son Hoang , Jedlicka Pavel , Tokan Viktor , Kubat Zdenek , Hobza Roman , Kejnovsky Eduard
Published: July 2022

Motivation

The role of repetitive DNA in the 3D organization of the interphase nucleus is a subject of intensive study. In studies of 3D nucleus organization, mutual contacts of various loci can be identified by Hi-C sequencing. Typical analyses use binning of read pairs by location to reduce noise. We use binning by repeat families instead to make similar conclusions about repeat regions.

Results

To achieve this, we combined Hi-C data, reference genome data and tools for repeat analysis into a Nextflow pipeline identifying and quantifying the contacts of specific repeat families. As an output, our pipeline produces heatmaps showing contact frequency and circular diagrams visualizing repeat contact localization. Using our pipeline with tomato data, we revealed the preferential homotypic interactions of ribosomal DNA, centromeric satellites and some LTR retrotransposon families and, as expected, little contact between organellar and nuclear DNA elements. While the pipeline can be applied to any eukaryotic genome, results in plants provide better coverage, since the built-in TE-greedy-nester software only detects tandems and LTR retrotransposons. Other repeats can be fed via GFF3 files. This pipeline represents a novel and reproducible way to analyze the role of repetitive elements in the 3D organization of genomes.

Availability and implementation

https://gitlab.fi.muni.cz/lexa/hic-te/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Inhibition of lysosomal acid β-glucosidase induces cell apoptosis via impairing mitochondrial clearance in pancreatic cancer
Authors: Yanagaki Mitsuru , Shirai Yoshihiro , Shimada Yohta , Hamura Ryoga , Taniai Tomohiko , Horiuchi Takashi , Takada Naoki , Haruki Koichiro , Furukawa Kenei , Uwagawa Tadashi , Kobayashi Hiroshi , Ikegami Toru
Published: July 2022

Sphingolipid metabolism plays an important role in the formation of cellular membranes and is associated with malignant potential and chemosensitivity of cancer cells. Sphingolipid degradation depends on multiple lysosomal glucosidases. We focused on acid β-glucosidase (GBA), a lysosomal enzyme the deficiency of which is related to mitochondrial dysfunction. We analyzed the function of GBA in pancreatic ductal adenocarcinoma (PDAC). Human PDAC cell lines (PANC-1, BxPC-3 and AsPC-1) were examined under conditions of GBA knockdown via the short interfering RNA (siRNA) method. We assessed the morphological changes, GBA enzyme activity, GBA protein expression, cell viability, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) and mitophagy flux of PDAC cells. The GBA protein level and enzyme activity differed among cell lines. GBA knockdown suppressed cell proliferation and induced apoptosis, especially in PANC-1 and BxPC-3 cells, with low GBA enzyme activity. GBA knockdown also decreased the MMP and impaired mitochondrial clearance. This impaired mitochondrial clearance further induced dysfunctional mitochondria accumulation and ROS generation in PDAC cells, inducing apoptosis. The antiproliferative effects of the combination of GBA suppression and gemcitabine were higher than those of gemcitabine alone. These results showed that GBA suppression exerts a significant antitumor effect and may have therapeutic potential in the clinical treatment of PDAC.
Excessive risk and poor outcome of hospital-acquired peritoneal dialysis-related peritonitis
Authors: Szeto Cheuk-Chun , Ng Jack Kit-Chung , Fung Winston Wing-Shing , Chan Gordon Chun-Kau , Cheng Phyllis Mei-Shan , Law Man-Ching , Pang Wing-Fai , Li Philip Kam-Tao , Leung Chi-Bon , Chow Kai-Ming
Published: July 2022

Background

Peritoneal dialysis (PD) is a home-based renal replacement therapy. Since hospital staff are not often familiar with PD and its complications, PD patients may have an excess risk of developing PD-related peritonitis during hospital admission for unrelated reasons, and the outcome may be affected.

Methods

We reviewed 371 episodes of hospital-acquired PD peritonitis in our center from 2000 to 2019. Their clinical characteristics and outcomes were compared with 825 episodes that required hospital admission and 1964 episodes that were treated as outpatient.

Results

Hospitalized PD patients had a significantly higher risk of developing peritonitis than outpatients [incident rate ratio 4.41 (95% confidence interval 3.95–4.91]. Hospital-acquired peritonitis episodes were more commonly culture negative. Bacterial isolates from the hospital-acquired episodes were more likely resistant to ceftazidime (P < .0001) than the other groups. The primary response rate, complete cure rate and overall mortality of the hospital-acquired episodes were 66.6%, 62.0%, and 23.2%, respectively, all worse than episodes that developed outside the hospital (P < .0001 for all).

Conclusion

PD patients admitted to the hospital had a 4-fold increase in the risk of developing peritonitis. Hospital-acquired peritonitis episodes were more likely culture negative and resistant to antibiotics. They also had a lower primary response rate, a lower complete cure rate and higher mortality than episodes that developed outside the hospital.