bluuebunny/crossref_metadata_2025 huggingface dataset:
The transverse electric plasmonic modes in a negative refractive index black phosphorene waveguide structure
Authors: Yang C H , Zhang J Y , Wieser R , Xu W
Published: November 2021

We consider the transverse electric (TE) plasmonic modes supported by black phosphorene (BP) in a parallel waveguide structure with left-handed material (LHM) instead of the conventional right-handed dielectric material. The existence condition of the TE BP surface plasmon polariton (SPP) is

I
m

σ
>
0

. When an electric field is polarized along one of the two orthogonal crystal axes, the anisotropic symmetric and anti-symmetric plasmonic modes depend on the incident optical energy, the chemical potential, and the distance between two BP sheets can be observed. The symmetric mode has a more extensive effective refractive index, which possesses stronger field confinement. With a decreasing distance d between two BP sheets, the coupling strength between the two separate BPSPP waves increases. When d is small enough, the anti-symmetric mode root does not exist. LHMs can be used to realize a TE BPSPP mode to enhance the localization of the BPSPP, which is a practical method in optoelectronic devices based on black phosphorene.
Bending strain in 3D topological semi-metals
Authors: Diaz Jonas , Putzke Carsten , Huang Xiangwei , Estry Amelia , Analytis James G , Sabsovich Daniel , Grushin Adolfo G , Ilan Roni , Moll Philip J W
Published: November 2021

We present an experimental set-up for the controlled application of strain gradients by mechanical piezoactuation on 3D crystalline microcantilevers that were fabricated by focused ion beam machining. A simple sample design tailored for transport characterization under strain at cryogenic temperatures is proposed. The topological semi-metal Cd3As2 serves as a test bed for the method, and we report extreme strain gradients of up to

1.3
%
 
μ

m−1 at a surface strain value of

≈

0.65
%

at 4 K. Interestingly, the unchanged quantum transport of the cantilever suggests that the bending cycle does not induce defects via plastic deformation. This approach is a first step towards realizing transport phenomena based on structural gradients, such as artificial gauge fields in topological materials.
Compact balanced diplexer based on hairpin split ring resonators with high isolation performance
Authors: Kuang Jiaxin , Liu Haiwen , Feng Linping , Tian Hongliang
Published: November 2021

In this paper, a compact balanced diplexer using a novel hairpin split ring resonator (H-SRR) is presented and demonstrated. First, the working principle of the proposed H-SRR is described, which shows a negative permittivity or a negative permeability in the stopband. It can be used to construct compact passive components and improve the stopband rejection performance. Then, the differential-mode (DM) excitation and common-mode (CM) excitation are investigated, respectively. Under DM operation, the H-SRR can provide one DM resonant mode. Under CM operation, the H-SRR can excite two CM resonant modes far from the DM resonant mode, thus producing a desired CM rejection performance. Moreover, by introducing a mixed electromagnetic coupling, transmission zeros are produced, significantly improving the DM isolation between the two channels. Finally, a balanced diplexer is designed and fabricated. The lower and higher channels of the diplexer are centered at 3.36 and 4.00 GHz. The DM channel isolation is better than 40/41 dB in the two passbands when the frequency ratio is less than 1.2, which is in satisfactory agreement with the simulated results.
In-situ measurement of dust charge density in nanodusty plasma
Authors: Staps Tim Jacobus Adrianus , Maria Donders Tim Jacobus , Platier Bart , Beckers Job
Published: November 2021

A dust grain immersed in a low-pressure gas discharge obtains a permanent negative surface charge due to the high mobility of electrons compared to that of ions. This charge essentially governs all fundamental processes in dusty and complex plasmas involving dust grains, neutrals, (an)ions and electrons and—consequently—virtually all industrial applications of these types of plasmas are affected and steered by it. In this work, we have measured the surface charge by application of laser-induced electron detachment from nanosized dust grains in concert with microwave cavity resonance spectroscopy and laser light extinction. The main result is that the electron release is governed by photodetachment rather than by thermionic emission, and that recharging of the dust grains occurs on timescales that are well in agreement with the orbital-motion-limited (OML) theory. The total surface charge density residing on the dust grains inside the laser volume follows from the saturation of the photodetachment signal, which was used in combination with dust density values derived from extinction measurements to estimate the mean dust charge. The negative dust charge on the 140 nm (average) diameter dust grains in this work is obtained to be in the range of 273 – 2519 elementary charges, of which the lower bound matches well with analytical predictions using the OML theory.
Mechanism, theory and application research of a rotating electromagnetic energy harvester suitable for multi-directional excitation
Authors: Guo Shengkai , Gao Shiqiao , Jin Lei , Du Xueda , Yin Zuozong , Wu Qinghe , Li Zezhang
Published: November 2021

Energy harvesting in multi-directional excitation for human wearable devices is a challenge. A rotating electromagnetic energy harvester (REMEH) based on an eccentric rotor structure is proposed in this paper. Two poles of the magnets in the REMEH are alternately arranged in a ring. The electrical output characteristics of the energy harvester are analyzed through theoretical, numerical simulation and experimental testing methods based on the establishment of magnetic flux density models, the coil induced voltage, and the excitation direction of the eccentric rotor structure. Theoretical analysis and experimental results show that the design of the eccentric rotor structure is well adapted to multi-directional and irregular excitation. The circular staggered arrangement of the magnets effectively increases the output voltage and output power. The results show that the average output power increases slowly when the walking speed increases from 1 to 3 km h−1, and the average output power increases substantially when the walking speed increases from 3 to 5 km h−1. When the walking speed is 1 and 3 km h−1, the average output power is 0.439 and 0.638 mW, respectively. At a walking speed of 5 km h−1, the average output power increases rapidly to 1.68 mW, corresponding to a power density of 16.59 μW g−1. This high-performance energy harvester can provide effective power supply for wearable devices or low-powered sensors.
The effect of substitutional doping of Yb2+ on structural, electronic, and optical properties of CsCaX
3 (X: Cl, Br, I) phosphors: a first-principles study
Authors: Khan Rashid , Ur Rahman Kaleem , Zhang Qingmin , Rahman Altaf Ur , Azam Sikander , Dahshan Alaa
Published: November 2021

Using first-principles calculations, the effects of Yb2+ substitutional doping on structural, electronic, and optical properties of a series of perovskite compounds CsCaX
3 (X: Cl, Br, I), have been investigated. We employed generalized gradient approximation (GGA) and HSE hybrid functional to study the electronic and optical properties. A series of pristine CsCaX
3 (X: Cl, Br, I) is characterized as a non-magnetic insulator with indirect bandgap perovskite materials. These phosphor materials are suitable candidates for doping with lanthanide series elements to tune their electronic bandgaps according to our requirements because of their wide bandgaps. The calculated electronic bandgaps of CsCaX
3 (X: Cl, Br, I) are 3.7 eV (GGA) and 4.5 eV (HSE) for CsCaI3, 4.5 eV (GGA) and 5.3 eV (HSE) for CsCaBr3, and 5.4 eV (GGA) and 6.4 eV (HSE) for CsCaCl3. According to formation energies, the Yb2+ doped at the Ca-site is thermodynamically more stable as compared to all possible atomic sites. The electronic band structures show that the Yb2+ doping induces defective states within the bandgaps of pristine CsCaX
3 (X: Cl, Br, I). As a result, the Yb2+ doped CsCaX
3 (X: Cl, Br, I) become the direct bandgap semiconductors. The defective states above the valence band maximum are produced due to the f-orbital of the Yb atom. The impurity states near the conduction band minimum are induced due to the major contribution of d-orbital of the Yb atom and the minor contribution of s-orbital of the Cs atom. The real and imaginary parts of the dielectric function, optical reflectivity, electron energy loss spectrum, extinction coefficient, and refractive index of pristine and Yb2+ doped CsCaX
3 (X: Cl, Br, I) were studied. The optical dispersion results of dielectric susceptibility closely match their relevant electronic structure and align with previously reported theoretical and experimental data. We conclude that the Yb2+ doped CsCaX
3 (X: Cl, Br, I) are appealing candidates for optoelectronic devices.
Quince seed mucilage coated iron oxide nanoparticles for plasmid DNA delivery
Authors: Nikforouz Bahar , Allafchian Alireza , Jalali Seyed Amir Hossein , Shakeripour Hamideh , Mohammadinezhad Rezvan
Published: November 2021

This study investigates the potential of iron oxide nanoparticles (Fe3O4) and quince seed mucilage as combined genetic carriers to deliver plasmid DNA (pDNA) through the gastrointestinal system. The samples are characterized by x-ray diffraction (XRD), zeta potential, dynamic light scattering, FT-IR spectroscopy, field emission scanning electron microscopy and vibrating sample magnetometry. The stability of pDNA loading on the nanocarriers and their release pattern are evaluated in simulated gastrointestinal environments by electrophoresis. The XRD patterns reveal that the nanocarriers could preserve their structure during various synthesis levels. The saturation magnetization (M
s) of the Fe3O4 cores are 56.48 emu g−1 without any magnetic hysteresis. Not only does the loaded pDNA contents experience a remarkable stability in the simulated gastric environment, but also, they could be released up to 99% when exposed to an alkaline environment similar to the intestinal fluid of fish. The results indicate that the synthesized nanoparticles could be employed as efficient low-cost pDNA carriers.
Prominent antibacterial effect of sub 5 nm Cu nanoparticles/MoS2 composite under visible light
Authors: Li Jingze , Ma Jiaxin , Hong Liu , Yang Cheng
Published: November 2021

Achieving an efficient and inexpensive bactericidal effect is a key point for the design of antibacterial agent. Recent advances have proved molybdenum disulfide (MoS2) as a promising platform for antimicrobial applications, while the combination of metal nanoparticle would promote the antibacterial efficiency. Nevertheless, the dispersivity, cheapness and safety of metal nanoparticle loaded on MoS2 raised some concerns. In this paper, we successfully realized a uniform decoration of copper nanoparticles (CuNPs) on surface of MoS2 nanosheets, and the size of CuNPs could be controlled below 5 nm. Under 5 min irradiation of 660 nm visible light, the synthesized CuNPs/MoS2 composite demonstrated superior antibacterial performances (almost 100% bacterial killed) towards both Gram-negative E. coli and Gram-positive S. aureus over the single component (Cu or MoS2), while the bactericidal effect could last for at least 6 h. The synergism of photodynamic generated hydroxyl radical (·OH), oxidative stress without reactive oxygen species production and the release of Cu ions was considered as the mechanism for the antibacterial properties of CuNPs/MoS2. Our findings provided new insights into the development of two-dimensional antibacterial nanomaterials of high cost performance.
Liver tumor detection based on objects as points
Authors: Peng Xuefeng , Yang Xinwu
Published: November 2021

The automatic detection of liver tumors by computed tomography is challenging, owing to their wide variations in size and location, as well as to their irregular shapes. Existing detection methods largely rely on two-stage detectors and use CT images marked with bounding boxes for training and detection. In this study, we propose a single-stage detector method designed to accurately detect multiple tumors simultaneously, and provide results demonstrating its increased speed and efficiency compared to prior methods. The proposed model divides CT images into multiple channels to obtain continuity information and implements a bounding box attention mechanism to overcome the limitation of inaccurate prediction of tumor center points and decrease redundant bounding boxes. The model integrates information from various channels using an effective Squeeze-and-Excitation attention module. The proposed model obtained a mean average precision result of 0.476 on the Decathlon dataset, which was superior to that of the prior methods examined for comparison. This research is expected to enable physicians to diagnose tumors very efficiently; particularly, the prediction of tumor center points is expected to enable physicians to rapidly verify their diagnostic judgments. The proposed method is considered suitable for future adoption in clinical practice in hospitals and resource-poor areas because its superior performance does not increase computational cost; hence, the equipment required is relatively inexpensive.
Effect of tailored density profiles on the stability of imploding Z-pinches at microsecond rise time megaampere currents
Authors: Cherdizov R K , Baksht R B , Kokshenev V A , Oreshkin V I , Rousskikh A G , Shishlov A V , Shmelev D L , Zhigalin A S
Published: November 2021

To study the effect of the radial density profile of the material of a metal-plasma Z-pinch load on the development of magneto-Rayleigh–Taylor (MRT) instabilities, experiments have been performed at the Institute of High Current Electronics with the GIT-12 generator which produces microsecond rise time megaampere currents. The Z-pinch load was an aluminum plasma jet (PJ) with an outer plasma shell. This configuration leads to the formation of a uniform current sheath in a Z-pinch load upon application of a high-voltage pulse. It was successfully used in experiments with hybrid deuterium gas-puffs (Klir et al 2020 New J. Phys.
22 103036). The initial density profiles of the Z-pinch loads were estimated from the pinch current and voltage waveforms using the zero-dimensional ‘snowplow’ model, and they were verified by simulating the expansion of the PJ formed by a vacuum arc using a two-dimensional quasi-neutral hybrid model (Shmelev et al 2020 Phys. Plasmas
27 092708). Two Z-pinch load configurations were used in the experiments. The first configuration provided tailored load density profiles, which could be described as ρ(r) ≈ 1/r^s for s > 2. In this case, MRT instabilities were suppressed and thus a K-shell radiation yield of 11 kJ cm−1 and a peak power of 0.67 TW cm−1 could be attained at a current of about 3 MA. For the second configuration, the radial density profiles were intentionally changed using a reflector. This led to the appearance of a notch in the density profiles at radii of 1–3 cm from the pinch axis and to magnetohydrodynamic instabilities at the final implosion stage. As a result, the K-shell radiation yield more than halved and the power decreased to 0.15 TW cm−1 at a current of about 3.5 MA.
Soliton generation and drift wave turbulence spreading via geodesic acoustic mode excitation
Authors: Chen Ningfei , Wei Shizhao , Wei Guangyu , Qiu Zhiyong
Published: November 2021

The two-field equations that govern fully nonlinear dynamics of the drift wave (DW) and geodesic acoustic mode (GAM) interaction in toroidal geometry are derived within the nonlinear gyrokinetic framework. Two stages with distinctive features are identified and analyzed using both analytical and numerical approaches. In the ‘linear’ growth stage, the derived set of nonlinear equations can be reduced to the intensively studied parametric decay instability, accounting for the spontaneous resonant excitation of GAM by the DW. The main results of previous works on spontaneous GAM excitation, e.g. the greatly enhanced GAM group velocity and the nonlinear growth rate of GAM, are reproduced from the numerical solution of the two-field equations. In the fully nonlinear stage, soliton structures are observed to form due to the balancing of the self-trapping effect by the spontaneously excited GAM and kinetic dispersiveness of the DW. The soliton structures enhance turbulence spreading from the DW linearly unstable region to the stable region, exhibiting convective propagation instead of a typical linear dispersive process, and are thus expected to induce core-edge interaction and nonlocal transport.
Modeling of high power impulse magnetron sputtering discharges with graphite target
Authors: Eliasson H , Rudolph M , Brenning N , Hajihoseini H , Zanáška M , Adriaans M J , Raadu M A , Minea T M , Gudmundsson J T , Lundin D
Published: November 2021

The ionization region model (IRM) is applied to model a high power impulse magnetron sputtering discharge in argon with a graphite target. Using the IRM, the temporal variation of the various species and the average electron energy, as well as internal parameters such as the ionization probability, back-attraction probability, and the ionized flux fraction of the sputtered species, is determined. It is found that thedischarge develops into working gas recycling and most of the discharge current at the cathode target surface is composed of Ar+ ions, which constitute over 90% of the discharge current, while the contribution of the C+ ions is always small (

<
5

%), even for peak current densities close to 3 A cm−2. For the target species, the time-averaged ionization probability ⟨α
t,pulse⟩ is low, or 13–27%, the ion back-attraction probability during the pulse β
t,pulse is high (

>
92

%), and the ionized flux fraction is about 2%. It is concluded that in the operation range studied here it is a challenge to ionize carbon atoms, that are sputtered off of a graphite target in a magnetron sputtering discharge, when depositing amorphous carbon films.
A study of mechanoelectrical transduction behavior in polyvinyl chloride (PVC) gel as smart sensors
Authors: Neubauer Justin , Olsen Zakai J , Frank Zachary , Hwang Taeseon , Kim Kwang J
Published: November 2021

Polyvinyl chloride (PVC) gels are soft electroactive polymers (EAPs) being researched for soft robotic applications. Sensing properties of these EAPs have not been investigated in detail in regard to fundamental mechanoelectrical transduction behavior, but this smart material has been shown to exhibit a detectable response to external stimuli. This study shows PVC gels to be an extremely sensitive material when undergoing mechanoelectrical transduction and explores some response dependencies and proposes a theoretical framework for mechanoelectrical transduction within the gel. The work presented here also uncovers a very interesting phenomena under extremely low compressive loads during the initial contact with the gel. This phenomenon is attributed to a surface tension creeping motion onto the loading surface with an accompanying polarity inversion in the sensing signal relative to fully loaded gels in compression. Experimental work on hysteresis was also completed showing very little memory in steady state mechanoelectrical response to repeated stepped loading cycles. This study demonstrates the mechanoelectric ability of PVC gels to perform in sensing experiments and acts as a fundamental framework to further broaden the applications of PVC gel sensors.
Ab initio calculations of the elastic, vibrational, electronic properties, and electron-phonon constant of superconducting YB6 compound under low pressure
Authors: Romero M , Arévalo-López E P , Rosas-Huerta J L , Antonio J E , Benitez-Rico A , Marquina M L , Escamilla R
Published: November 2021

The crystal structure, mechanical, electronic properties, as well as the electron-phonon constant of YB6 under low pressure (<1.0 GPa) were investigated by first-principles density functional theory (DFT) within the bounds of the generalized gradient approximation (GGA). The calculated cell parameter a at zero pressure is in good agreement with the reported experimental and theoretically data and decreases as pressure increases. Under pressure, the elastic constants and mechanical moduli increase while the hardness decreases. The calculated elastic constants reveals mechanical stability up to 1 GPa. Pugh's criterion and Poisson's ratio suggest that the compound has ductile behavior. The electronic density of states (DOS) under pressure shows a slight decrease due to reducing the B 2p states. Finally, the electron-phonon coupling constant (λ

e−f
) was determined using the Debye temperature and the McMillan equation, the value found was λ

e−f
 = 0.53 as a function of pressure; therefore, our results suggest that the YB6 is an intermediate coupling superconductor.
Gamma radiation shielding properties of recycled polyvinyl chloride composites reinforced with micro/nano-structured PbO and CuO particles
Authors: El-Khatib Ahmed M , Abbas Yehia M , Badawi Mohamed S , Hagag Osama M , Alabsy Mahmoud T
Published: November 2021

In this work, the γ-ray shielding characteristics of fabricated recycled polyvinyl chloride (rPVC) loaded with micro and nano fillers of PbO and CuO composites were investigated. The PbO/rPVC and CuO/rPVC composites were prepared by changing the percentage of injected materials (PbO and CuO) between 10% and 40% with additions by 10%. Gamma-ray attenuation properties, such as mass attenuation coefficients, linear attenuation coefficients and half-value layer for PbO and CuO-supported polymers were obtained in the energy range between 59.5 and 1408.0 keV using narrow beam transmission geometry. These experiments were carried out by using a HPGe detector and five standard radioactive sources [241Am, 133Ba, 137Cs, 60Co and 152Eu]. Moreover, equivalent atomic numbers and the exposure buildup factor (EBF) values for incident photon energy in the range from 0.015 MeV to 15 MeV were also calculated by Geometric Progression (G-P) method. The experimental results revealed that, the measured values of the linear attenuation coefficients of the PbO/rPVC and CuO/rPVC composites showed their dependence on the type and the concentration of the filler (either PbO or CuO) and also on the incident gamma ray energy. Increasing the filler weight fractions wt.% in the rPVC matrix, increases the linear attenuation coefficients of the composite and the improvement is more significant in case of PbO compared to CuO of the same filler wt.% at the same energy. The results also demonstrated an enhancement in the radiation protection behavior of rPVC composites due to the addition of PbO and CuO fillers as nano-sized particles.
A mathematical model of enzymatic non-competitive inhibition by product and its applications
Authors: Mai Vinh Quang , Nhan Thái Anh , Hammouch Zakia
Published: November 2021

Enzymes are biological catalysts naturally present in living organisms, and they are capable of accelerating biochemical reactions in the metabolism process. Cells use many regulatory mechanisms to regulate the concentrations of cellular metabolites at physiological levels. Enzymatic inhibition is one of the key regulatory mechanisms naturally occurring in cellular metabolism, especially the enzymatic non-competitive inhibition by product. This inhibition process helps the cell regulate enzymatic activities. In this paper, we develop a novel mathematical model describing the enzymatic non-competitive inhibition by product. The model consists of a coupled system of nonlinear ordinary differential equations for the species of interest. Using nondimensionalization analysis, a formula for product formation rate for this mechanism is obtained in a transparent manner. Further analysis for this formula yields qualitative insights into the maximal reaction velocity and apparent Michaelis-Menten constant. Asymptotic solutions of the model are carefully given by using the homotopy perturbation analysis. A good agreement between the asymptotic solutions and numerical solutions are found. In addition, a Sobol global sensitivity analysis is implemented to help identify the key mechanisms of the enzyme activities. The results of this analysis show that the rate of product formation is relatively sensitive to the following factors: the catalytic rate of the enzyme, the rates of binding/unbinding of the product to/from the enzyme/enzyme complex. The numerical simulations provide insights into how variations in the model parameters affect the model output. Finally, an application of the model to the phosphorylation of glucose by mutant-hexokinase I enzyme is briefly discussed.
Finding sound shells in LISA mock data using likelihood sampling
Authors: Giese Felix , Konstandin Thomas , van de Vis Jorinde
Published: November 2021

We study to what extent LISA can observe features of gravitational
wave spectra originating from cosmological first-order phase transitions.
We focus on spectra which are of the form of double-broken power laws.
These spectra are predicted by hydrodynamic simulations and also analytical models such as
the sound shell model. We argue that the ratio of the two break frequencies is
an interesting observable since it can be related to the wall velocity
while overall amplitude and frequency range are often degenerate for the numerous
characteristics of the phase transition. Our analysis uses mock data obtained from the power spectra predicted by the simplified simulations and the sound shell model and analyzes the detection prospects using χ2-minimization and likelihood sampling. We point out that the prospects of observing
two break frequencies from the electroweak phase transition is hindered by a shift of the spectrum to smaller frequencies for strong phase
transitions. Finally, we also highlight some
differences between signals from the sound shell model compared to simulations.
Possible dibaryon production at

anda with a Lagrangian approach *
Authors: Dong Yubing , Shen Pengnian
Published: November 2021

In order to confirm the existence of the dibaryon state

observed at WASA@COSY, we estimate the cross section for production of the possible dibaryon and anti-dibaryon pair

in the energy region of the upcoming experiments at

anda. Based on some qualitative properties of

extracted from the analyses in the non-relativistic quark model, the production cross section for this spin-3 particle pair are calculated with the help of a phenomenological effective relativistic and covariant Lagrangian approach.
EEG-based brain–computer interfaces exploiting steady-state somatosensory-evoked potentials: a literature review
Authors: Petit Jimmy , Rouillard José , Cabestaing François
Published: November 2021

A brain–computer interface (BCI) aims to derive commands from the user’s brain activity in order to relay them to an external device. To do so, it can either detect a spontaneous change in the mental state, in the so-called ‘active’ BCIs, or a transient or sustained change in the brain response to an external stimulation, in ‘reactive’ BCIs. In the latter, external stimuli are perceived by the user through a sensory channel, usually sight or hearing. When the stimulation is sustained and periodical, the brain response reaches an oscillatory steady-state that can be detected rather easily. We focus our attention on electroencephalography-based BCIs (EEG-based BCI) in which a periodical signal, either mechanical or electrical, stimulates the user skin. This type of stimulus elicits a steady-state response of the somatosensory system that can be detected in the recorded EEG. The oscillatory and phase-locked voltage component characterising this response is called a steady-state somatosensory-evoked potential (SSSEP). It has been shown that the amplitude of the SSSEP is modulated by specific mental tasks, for instance when the user focuses their attention or not to the somatosensory stimulation, allowing the translation of this variation into a command. Actually, SSSEP-based BCIs may benefit from straightforward analysis techniques of EEG signals, like reactive BCIs, while allowing self-paced interaction, like active BCIs. In this paper, we present a survey of scientific literature related to EEG-based BCI exploiting SSSEP. Firstly, we endeavour to describe the main characteristics of SSSEPs and the calibration techniques that allow the tuning of stimulation in order to maximise their amplitude. Secondly, we present the signal processing and data classification algorithms implemented by authors in order to elaborate commands in their SSSEP-based BCIs, as well as the classification performance that they evaluated on user experiments.
Skilled independent control of individual motor units via a non-invasive neuromuscular–machine interface
Authors: Formento Emanuele , Botros Paul , Carmena Jose M
Published: November 2021

Objective. Brain–machine interfaces (BMIs) have the potential to augment human functions and restore independence in people with disabilities, yet a compromise between non-invasiveness and performance limits their relevance. Approach. Here, we hypothesized that a non-invasive neuromuscular–machine interface providing real-time neurofeedback of individual motor units within a muscle could enable independent motor unit control to an extent suitable for high-performance BMI applications. Main results. Over 6 days of training, eight participants progressively learned to skillfully and independently control three biceps brachii motor units to complete a 2D center-out task. We show that neurofeedback enabled motor unit activity that largely violated recruitment constraints observed during ramp-and-hold isometric contractions thought to limit individual motor unit controllability. Finally, participants demonstrated the suitability of individual motor units for powering general applications through a spelling task. Significance. These results illustrate the flexibility of the sensorimotor system and highlight individual motor units as a promising source of control for BMI applications.
Siberian 2020 heatwave increased spring CO2 uptake but not annual CO2 uptake
Authors: Kwon Min Jung , Ballantyne Ashley , Ciais Philippe , Bastos Ana , Chevallier Frédéric , Liu Zhihua , Green Julia K , Qiu Chunjing , Kimball John S
Published: November 2021

Siberia experienced an unprecedented strong and persistent heatwave in winter to spring of 2020. Using bottom–up and top–down approaches, we evaluated seasonal and annual CO2 fluxes of 2020 in the northern hemisphere (north of 30 °N), focusing on Siberia where the pronounced heatwave occurred. We found that, over Siberia, CO2 respiration loss in response to the pronounced positive winter temperature anomaly was greater than in previous years. However, continued warming in the spring enhanced photosynthetic CO2 uptake, resulting in the largest seasonal transition in net ecosystem CO2 exchange; that is, the largest magnitude of the switch from the net CO2 loss in winter to net CO2 uptake in spring until June. However, this exceptional transition was followed by the largest reduction in CO2 uptake in late summer due to multiple environmental constraints, including a soil moisture deficit. Despite a substantial increase of CO2 uptake by 22 ± 9 gC m−2 in the spring in response to the heatwave, the mean annual CO2 uptake over Siberia was slightly lower (3 ± 13 gC m−2yr−1) than the average of the previous five years. These results highlight the highly dynamic response of seasonal carbon fluxes to extreme temperature anomalies at high latitudes, indicating a seasonal compensation between abnormal uptake and release of CO2 in response to extreme warmth that may limit carbon sink capacity in high northern latitudes.
Indices Extraction from Multitemporal Remote Sensing Data for Mapping Urban Built-Up
Authors: Hayati A. K. , Hestrio Y.F. , Cendiana N. , Kustiyo K.
Published: November 2021

Remote sensing data analysis in the cloudy area is still a challenging process. Fortunately, remote sensing technology is fast growing. As a result, multitemporal data could be used to overcome the problem of the cloudy area. Using multitemporal data is a common approach to address the cloud problem. However, most methods only use two data, one as the main data and the other as complementary of the cloudy area. In this paper, a method to harness multitemporal remote sensing data for automatically extracting some indices is proposed. In this method, the process of extracting the indices is done without having to mask the cloud. Those indices could be further used for many applications such as the classification of urban built-up. Landsat-8 data that is acquired during 2019 are stacked, therefore each pixel at the same position creates a list. From each list, indices are extracted. In this study, NDVI, NDBI, and NDWI are used to mapping built-up areas. Furthermore, extracted indices are divided into four categories by their value (maximum, quantile 75, median, and mean). Those indices are then combined into a simple formula to mapping built-up to see which produces better accuracy. The Pleiades as high-resolution remote sensing data is used to assist supervised classification for assessment. In this study, the combination of mean NDBI, maximum NDVI, and mean NDWI result highest Kappa coefficient of 0.771.
Assessment of Rapid Urban Development Impact for a Small-Sized Transit City Using Remote Sensing: A Case Study of Salatiga, Indonesia
Authors: Dewa D. D. , Buchori I.
Published: November 2021

Salatiga is the connecting city between Semarang City and Surakarta, which makes it one of the small-sized transit cities in Central Java. Its strategic location has led to various developments being carried out in Salatiga in the last ten years. This study aimed to assess the impact of the rapid development of Salatiga as a transit city. This study utilized remote sensing to analyze land cover changes and changes in land surface temperature (LST). The results showed that Salatiga experienced more significant growth in the built-up area than the population growth. The rapid development in Salatiga creates various new activities, such as trade and services and industries. This development changed the land cover and affected the land surface temperature in Salatiga. In the last ten years, Salatiga experienced an average temperature increase of 0.23°C. Mitigation efforts are needed to suppress environmental changes in the future.
Mapping of Vegetation Development Zone to Enhance the Coastal Community Resiliency
Authors: Dewi S. P. , Kurniati R. , Sarasadi A.
Published: November 2021

Climate change has implications for the environment and community such as the existence of climate-related disasters. The changes of weather cycle triggers flooding in coastal areas, then high water discharge eroded the soil and caused landslides. Land conversion of upstream area causes low water absorption and high run-off which also contributes to flooding and landslides in the downstream area. Efforts to normalize rivers and urban drainage have not been able to cope with floods and landslides. Therefore, it needs an effort to minimize these disasters. The vegetative approach is an alternative for mitigating floods and landslides that are considered more comprehensive which not only conserves landscapes but also contributes to increasing green open space provision. This study aims to analyse the possibility of applying a vegetative approach to improve the physical and socio-economic community’s resiliency in coastal areas from climate-related disasters. The research method used a quantitative method with data collection techniques through literature studies, field observations, and questionnaires. The data processing stages include analysis of the physical condition to determine the physical vulnerability of the area through the physical natural map overlay technique; analysis of the climate-related disasters impact on society through descriptive statistical analysis techniques; and analysis of the possibility of applying the vegetative approach by using spatial analysis techniques to determine the level of vulnerability and priority zones for vegetation development.
Effect of Changes Composition and Intensity of Green Space on Surface Temperature: Case Study in Pekalongan Regency, Indonesia
Authors: Pradana A. , Pugara A. , Puspasari D. A.
Published: November 2021

The spatial planning document is planning guidance intended to regulate an area’s spatial use and development planning. This document contains the component that regulates the composition of green space. This composition is designed to maintain the stability of the existing ecosystem quality. Pekalongan is one of the Regency in Central Java Province with environmental problems related to lack of green space area. The existence of ecological degradation makes environmental quality in Pekalongan one that needs to be considered. This study aims to determine the effect of changes in the composition and intensity of green space on surface temperature from these problems. This study will use time-series data during the initial implementation of spatial planning documents (2013) to the current year (2021) to see how changes in the composition and intensity of green space in each sub-district in Pekalongan Regency. The method used is descriptive quantitative with a GIS approach. The result of this study can be a consideration to make policies related to green space.
Spatial Modeling of Environmental Quality Change Based on Geographic Information System
Authors: Wiratmaja I. G. , Sejati A. W.
Published: November 2021

A coastal area is prone to decrease of environmental quality due to coastal land abrasion and inundation/tidal flood. Several studies have shown that the coastline of Sayung District, Demak Regency, is moving toward the mainland for 6.8 mm/year and the surrounding area is experiencing land subsidence for 5-7 cm/year. These phenomena have consequences to the environmental quality in the area. In this case, this research aims to develop a spatial model using a Geographical Information System (GIS) in describing and predicting changes of environmental quality in Sayung District, Demak Regency. Four variables in a Risk-Screening Ecological Index (RSEI) approach, namely (1) vegetation density, (2) soil moisture, (3) soil quality, and (4) built space and surface temperature were used as indicators of the environmental quality. A raster calculator and Spatial Principal Component Analysis (SPCA) were then used to calculate total value of the environmental quality. This research results that the environmental quality of the study area is decreasing which indicated by the RSEI value of 0.614 (1999), 0.4749 (2009), and 0.3933 (2019). The environmental quality in the study area is also worsened by waterbody expansion.
The Social Restrictions Impact on Urban Heat Island Phenomena (Case Study: Cities in Java Island)
Authors: Agni A. M. , Pangi P. , Septiarani B. , Astuti K. D.
Published: November 2021

The Coronavirus Disease 2019 (Covid-19) pandemic has hit Indonesia since March 14, 2020. The rapid spread of the virus has caused the central and regional governments to implement community activity policies. Some terms and methods used by local governments such as PSBB (the Large-Scale Social Restrictions) are applied in Special Capital Region of Jakarta and Surabaya City, in Semarang City has PKM (Restrictions on Community Activities). This study aims to analyze the impact of the social restrictions on Urban Heat Island (UHI) in the Java Island big city. This research was conducted in big cities on Java Island that apply social restrictions, namely Special Capital Region of Jakarta, Bandung, Semarang, Yogyakarta, Surakarta, Surabaya, and Malang. The data used are Landsat 8 satellite imagery in 2019 and 2020. The method used is to compare the magnitude of the Land Surface Temperature (LST) and UHI before and after social restrictions. The results of the analysis explain that there is a decrease in LST and changes in UHI in the cities of Special Capital Region of Jakarta, Bandung, Semarang, Surakarta, and Yogyakarta. However, in Surabaya and Malang, there was an increase in LST. This study concludes that the implementation of social restrictions affects changes in UHI and decreases LST.
Understanding Spatial Planning Policies in Responding to Urban Heat Island Using GIS Analysis in The Kendal Industrial Area
Authors: Ariani N. M. , Wijaya M. I. H. , Priambudi B. N.
Published: November 2021

The formulation of spatial planning strategies in an area is strongly influenced by the development of issues and problems in the area. Spatial planning policies contained in a regional regulation must be able to be aware of and deal with all current and future problems. Urban Heat Island) is currently a very growing issue in various regions in Indonesia which is influenced by many factors, one of which is the increase in built-up land. The issue of the Urban Heat Island is important because its effects are starting to be felt, including natural degradation, health, economic losses to excessive energy use. One of the most dominant areas in contributing to hot temperatures in urban areas is the industrial area. Kendal Regency is one of the regions in Indonesia with a fairly dominant industrial estate development. Industrial areas that are synonymous with built-up land, air pollution and the lack of green open spaces are one of the triggers for an increase in temperature. In contrast to the negative effects caused, the development of industrial estates in Kendal Regency is one of the drivers of the regional economy so that its existence is considered important. This study aims to understand spatial planning policies in response to the Urban Heat Island in the Kendal Regency industrial area. The research method used is spatial analysis using Landsat 8 imagery with supervised classification to see the UHI phenomenon in the Kendal industrial area, the results of which are used as a basis for evaluating spatial policies in response to UHI. The spatial policy of Kendal Regency in the designation of industrial areas has not fully responded to the UHI phenomenon in industrial areas, although 13 of the 14 clauses indicate the potential for an increase in surface temperature. UHI in the Kendal Regency spatial policy has not been seen as a threat to urban areas. Mitigation efforts against UHI mentioned are only in the form of providing green open space and waste management. It is hoped that this research can be input in improving spatial planning policies in the Kendal Regency industrial area, especially to suppress the increase in temperature.
Spatial Distribution on Recovery Strategy Due to The Impact of The Covid-19 Pandemic on The Conditions of Micro Small Medium Enterprises (MSME’s) in Central Java Province, Indonesia
Authors: Widiastuti W. , Handayani A. , Hermawan A.
Published: November 2021

MSMEs are the backbone of the economy in Indonesia. However, most MSMEs were collapse due to the Covid-19 pandemic. Therefore, MSMEs recovery is needed to restore the real sector, particularly in Central Java. The study analyses the impact and economic recovery strategies during and after Covid-9 in the MSME sector. The research used a descriptive qualitative method. Data were collected by electronic survey and in-depth interviews and analyzed by SWOT. The results showed the Covid-9 pandemic significantly reduced MSME business actors’ profits due to decreased sales, while production costs remained or even increased. The vulnerability of MSMEs closes their businesses based on the subjective perceptions of business actors is that most of them can survive for more than a year ahead (33.1%) and the next six months to one year (30%). The rest can last for less than one month to the next six months, starting from December 2020. MSME entrepreneurs took several strategies to keep their business running. The methods include looking for new markets, providing discounts and bonuses, diversifying products, giving a consignment, looking for cheaper suppliers/raw materials, and purchasing raw materials with the last payment due. Potential risks when MSMEs are unable to maintain business are (1) lousy credit; (2) layoffs for workers and bankruptcy for business owners; and (3) supply and demand drop. The government should take action to recover MSMEs. The promising policies are (1) Facilitate MSMEs with capital for purchasing raw materials, (2) Development local supply chains through trading houses and regional logistics, (3) Facilitating access to financing, production, and marketing, (4) Encouraging product diversification according to the current needs of consumers, (5) Development of the MSME entrepreneurial ecosystem with a multi-stakeholder approach.
Analysis of Land Potential for Infrastructure Development of Natural Gas Distribution Pipeline for Households in Bekasi Regency, Indonesia
Authors: Rosmayati L. , Eviani M. , Kurniawan D. , Lusyana L. , Atmanto M. D.
Published: November 2021

Priority locations and land for the construction of households natural gas connections in Bekasi Regency are determined based on considerations of regional topography, potential number of household customers (population or household density), proximity to gas tapping point and the absence of installed Jargas, and Bekasi Regency Regional Regulation No. 12 of 2011 concerning Spatial Planning (Rencana Tata Ruang Wilayah) for Bekasi Regency. Prior to the technical design of natural gas pipeline, land mapping was carried out with a geographic information system containing surface spatial data. Geospatial data analysis is used to identify potential locations as natural gas tapping points, locations to place Metering Reduction Stations (M/RS) and Regulating Sector (RS), as well as potential crossing locations in the design of natural gas distribution pipelines. Subsequently, a verification survey was conducted on the results of the geospatial data analysis which was compared with conditions in the field.
Evolution mechanism of cyclized structure of PAN-based pre-oxidized fiber during low temperature carbonization process
Authors: Wang Bin , Wu Shuai , Li Chenggao , Cao Weiyu
Published: November 2021

The low temperature carbonization process is an important stage to realize the structural transition from the organic cyclized structure of PAN based pre-oxidized fiber to the inorganic pseudo-graphite structure of the ultimate carbon fiber. In the present paper, the evolution mechanism of cyclized structure and aggregation structure of PAN stabilized fiber during low temperature carbonization was studied by means of TGA, 13C-NMR, XRD, XPS and Raman. The results indicated that when the heat-treated temperature was lower than 450 °C, the mainly chemical reactions were the dehydrogenation and pyrolysis reactions in acyclic linear molecular chain or partial cyclized structure. At this stage, the growth of cyclized structure was not obvious. While the original ordered structure was destroyed gradually and the internal stress increased significantly. It induced the cyclized structure to be further oriented. When the temperature was higher than 450 °C, the polycondensation and reconstruction in aromatic heterocyclic structure was more important. The early aromatic heterocycles had many different structural scales, poor homogeneity and many defects in the heterocycles. At this stage, a new pseudo-graphite crystalline structure gradually formed and the d-spacing of graphite layer decreased slightly and crystallites size increased slowly with the increase of heat-treated temperature. When the temperature was higher than 550 °C, the pseudo-graphite base structure gradually formed. The d-spacing were further reduced slightly, and the crystallites size increased slowly. A new ordered basis structure was gradually developed into carbon fiber.