bluuebunny/crossref_metadata_2025 huggingface dataset:
Paper-based potentiometric sensing devices modified with chemically reduced graphene oxide (CRGO) for trace level determination of pholcodine (opiate derivative drug)
Authors: Abd-Rabboh Hisham S. M. , El-Galil E. Amr Abd , A. Elsayed Elsayed , Sayed Ahmed Y. A. , Kamel Ayman H.
Published: March 2021

Robust, reliable and cost-effective paper-based analytical device for potentiometric pholcodine (opiate derivative drug) ion sensing has been prepared and characterized.
Disila- and digermabenzenes
Authors: Sasamori Takahiro
Published: March 2021

Reactions of isolable disilynes and digermynes with alkynes can result in the formation of the corresponding disila- (DSBs) and digermabenzenes (DGBs), wherein two carbon atoms of the benzene ring are replaced by silicon or germanium atoms.
Nickel-catalyzed enantioselective vinylation of aryl 2-azaallyl anions
Authors: Duan Shengzu , Deng Guogang , Zi Yujin , Wu Xiaomei , Tian Xun , Liu Zhengfen , Li Minyan , Zhang Hongbin , Yang Xiaodong , Walsh Patrick J.
Published: March 2021

A unique enantioselective Ni-catalyzed vinylation of 2-azaallyl anions is advanced. This method affords vinyl aryl methyl amine or 1,3-diamine derivatives with high enantioselectivities, which are frequently occurring scaffolds in medications.
Mechanically compliant single crystals of a stable organic radical
Authors: Commins Patrick , Dippenaar A. Bernard , Li Liang , Hara Hideyuki , Haynes Delia A. , Naumov Panče
Published: March 2021

Mechanically soft crystals are interesting candidates for single crystal electronics. Here, crystals of a stable dithiadiazolyl radical are shown to be plastically bendable and display a change in their spin density in response to mechanical force.
Stress relaxation in tunable gels
Authors: Raffaelli Chiara , Ellenbroek Wouter G.
Published: March 2021

Molecular dynamics shows how stress relaxation of tetra-PEG hydrogels with hybrid (permanent + reversible) crosslinks is set by the strength and concentration of the reversible bonds, which provides a way to improve the responsivity of these gels.
Design of Ni3N/Co2N heterojunctions for boosting electrocatalytic alkaline overall water splitting
Authors: Wen Yan , Qi Jingyao , Wei Peicheng , Kang Xu , Li Xin
Published: March 2021

The heterojunction structure accelerates the overall water splitting for transition metal nitrides. Pyridine nitrogen and metal ions that act as catalytic sites synergistically promote the electrocatalytic process.
Parkinson's disease and mitophagy: an emerging role for LRRK2
Authors: Singh Francois , Ganley Ian G.
Published: March 2021

Parkinson's disease (PD) is a progressive neurodegenerative disorder that affects around 2% of individuals over 60 years old. It is characterised by the loss of dopaminergic neurons in the substantia nigra pars compacta of the midbrain, which is thought to account for the major clinical symptoms such as tremor, slowness of movement and muscle stiffness. Its aetiology is poorly understood as the physiological and molecular mechanisms leading to this neuronal loss are currently unclear. However, mitochondrial and lysosomal dysfunction seem to play a central role in this disease. In recent years, defective mitochondrial elimination through autophagy, termed mitophagy, has emerged as a potential contributing factor to disease pathology. PINK1 and Parkin, two proteins mutated in familial PD, were found to eliminate mitochondria under distinct mitochondrial depolarisation-induced stress. However, PINK1 and Parkin are not essential for all types of mitophagy and such pathways occur in most cell types and tissues in vivo, even in the absence of overt mitochondrial stress — so-called basal mitophagy. The most common mutation in PD, that of glycine at position 2019 to serine in the protein kinase LRRK2, results in increased activity and this was recently shown to disrupt basal mitophagy in vivo. Thus, different modalities of mitophagy are affected by distinct proteins implicated in PD, suggesting impaired mitophagy may be a common denominator for the disease. In this short review, we discuss the current knowledge about the link between PD pathogenic mutations and mitophagy, with a particular focus on LRRK2.
Allosteric regulation of histone lysine methyltransferases: from context-specific regulation to selective drugs
Authors: Davidovich Chen , Zhang Qi
Published: March 2021

Histone lysine methyltransferases (HKMTs) are key regulators of many cellular processes. By definition, HKMTs catalyse the methylation of lysine residues in histone proteins. The enzymatic activities of HKMTs are under precise control, with their allosteric regulation emerging as a prevalent paradigm. We review the molecular mechanisms of allosteric regulation of HKMTs using well-studied histone H3 (K4, K9, K27 and K36) methyltransferases as examples. We discuss the current advances and future potential in targeting allosteric sites of HKMTs for drug development.
Effect of Training With Anchors on Auditory-Perceptual Evaluation of Dysphonia in Speech-Language Pathology Students
Authors: Wong Denise Wai-Man , Chan Roger W. , Wu Chia-Hsin
Published: March 2021

Purpose

Auditory-perceptual evaluation is essential for the clinical assessment of voice disorders. Unstable perceptual voice evaluation has been shown for inexperienced listeners as compared to expert listeners. We examined the effects of perceptual training with external auditory anchors with and without immediate feedback on the evaluation of roughness and breathiness of natural, nonsynthesized speech stimuli (reading of a standard passage) in speech-language pathology students.

Method

Perceptual voice evaluation and training with anchors using a visual analog scale was implemented with a computer software. Forty-eight speech-language pathology students were randomly assigned into three groups, feedback group (Group F), no feedback group (Group NF), and control group (Group C), attending one training session and four assessment sessions (before training, immediately after training, and 1 and 7 weeks after training). Group F received training with anchors with immediate feedback, Group NF received training without immediate feedback, and Group C received sham training (exposure session).

Results

Training with anchors significantly increased the rating accuracy (agreement with expert ratings) on both roughness and breathiness for Group F, with the effects lasting for 7 weeks. No significant changes in rating accuracy with training were observed for Group NF and Group C. No improvements in intra- and interrater reliability as well as intrarater agreement were observed in all three groups, whereas interrater agreement on breathiness (but not roughness) significantly increased for all groups, with the effect lasting for 7 weeks only for Group F.

Conclusions

These findings suggested that perceptual training with external auditory anchors and the use of immediate feedback could be effective for facilitating the development of perceptual voice evaluation skills in speech-language pathology students. Further studies involving more extensive training with stimuli covering a full range of dysphonia severity categories and improvements in design of the training protocol are recommended to verify these results.
Generalized Slowing Rather Than Inhibition Is Associated With Language Outcomes in Both Late Talkers and Children With Typical Early Development
Authors: Kautto Anna , Jansson-Verkasalo Eira , Mainela-Arnold Elina
Published: March 2021

Purpose

While most of the children who are identified as late talkers at the age of 2 years catch up with their peers before school age, some continue to have language difficulties and will later be identified as having developmental language disorder. Our understanding of which children catch up and which do not is limited. The aim of the current study was to find out if inhibition is associated with late talker outcomes at school age.

Method

We recruited 73 school-aged children (ages 7–10 years) with a history of late talking (
n
= 38) or typical development (
n
= 35). Children completed measures of language skills and a flanker task to measure inhibition. School-age language outcome was measured as a continuous variable.

Results

Our analyses did not reveal associations between inhibition and school-age language index or history of late talking. However, stronger school-age language skills were associated with shorter overall response times on the flanker task, in both congruent and incongruent trials. This effect was not modulated by history of late talking, suggesting that a relationship between general response times and language development is similar in both children with typical early language development and late talkers.

Conclusions

Inhibition is not related to late talker language outcomes. However, children with better language outcomes had shorter general response times. We interpret this to reflect differences in general processing speed, suggesting that processing speed holds promise for predicting school-age language outcomes in both late talkers and children with typical early development.

Supplemental Material

https://doi.org/10.23641/asha.14226722
Enhanced Mentored Undergraduate Research Experiences: Successful Strategies Used in Two Laboratories at Auburn University
Authors: Speights Atkins Marisha , Allison Lauren H. , Sandage Mary J.
Published: March 2021

Purpose

There is a growing trend toward the provision of undergraduate research experiences as a high impact educational practice that promotes the development of critical thinking and problem-solving skills. This tutorial aims to provide mentoring pathways and resources to faculty mentors who may be unaware of the benefits of undergraduate student participation in research or faculty researchers who are interested in developing meaningful mentored undergraduate research experiences (MUREs). Faculty and student perspectives shared from two research labs at Auburn University illustrate an applied framework for implementation of MUREs. The observed benefits and potential barriers related to the development of MUREs in these laboratories as well as specific recommendations for a structured mentoring approach to optimize student training and research deliverables are described.

Conclusions

Key elements for developing successful MUREs include relationship building between the mentor and the student, identifying the benefits for both the students and mentor, and persevering beyond barriers to implementation. The utilization of practical guides, theoretical approaches, and collaborative efforts yielded benefits for both students and mentoring faculty in two research labs at Auburn University. Practical guides for obtaining funding for MUREs and accompanying supplemental materials (a lab manual template and manuscript-writing guide) that have supported success in our labs are provided.

Supplemental Material

https://doi.org/10.23641/asha.14044067
Aberrations in ultrasound images are not just noise
Authors: Yiu Yuen
Published: March 2021

Researchers present an ultrasound imaging technique to reveal aberrating structures in a sample that would otherwise be invisible.
Metasurface-tuning: A camouflaging technique for dielectric obstacles
Authors: Cacocciola Riccardo , Ratni Badreddine , Mielec Nicolas , Mimoun Emmanuel , Burokur Shah Nawaz
Published: March 2021

We present the concept of metasurface-tuning as a solution to reduce spurious scattering from parasitic dielectric objects. By burying metasurfaces in the dielectric volume, it is possible to control the scattering behavior of the parasitic object and camouflage it with respect to a given dielectric reference. A transmission-line model is proposed for the metasurface’s surface impedance retrieval. Microwave near-field and far-field full-wave simulation results validate the scattering reduction of the dielectric parasitic object for both normal and off-normal transverse-electric and transverse-magnetic polarized incident waves. The frequency stability and robustness to a change of dielectric reference of the proposed technique is also studied in a frequency range around 10 GHz. The study suggests that metasurface-tuning can be a polarization-insensitive and frequency-adjustable solution to reduce spurious scattering from high-index, dielectric mechanical pieces such as seams in large ground-based radomes.
Deep-learning of parametric partial differential equations from sparse and noisy data
Authors: Xu Hao , Zhang Dongxiao , Zeng Junsheng
Published: March 2021

Data-driven methods have recently made great progress in the discovery of partial differential equations (PDEs) from spatial-temporal data. However, several challenges remain to be solved, including sparse noisy data, incomplete library, and spatially or temporally varying coefficients. In this work, a new framework, which combines neural network, genetic algorithm, and stepwise methods, is put forward to address all of these challenges simultaneously. In the framework, a trained neural network is utilized to calculate derivatives and generate a large amount of meta-data, which solves the problem of sparse noisy data. Next, the genetic algorithm is used to discover the form of PDEs and corresponding coefficients, which solves the problem of the incomplete initial library. Finally, a stepwise adjustment method is introduced to discover parametric PDEs with spatially or temporally varying coefficients. In this method, the structure of a parametric PDE is first discovered, and then the general form of varying coefficients is identified. The proposed algorithm is tested on the Burgers equation, the convection-diffusion equation, the wave equation, and the KdV equation. Results demonstrate that this method is robust to sparse and noisy data, and is able to discover parametric PDEs with an incomplete initial library.
Controlling relaxation dynamics of excitonic states in monolayer transition metal dichalcogenides WS2 through interface engineering
Authors: Wang Anran , Wang Yuhan , Li Jianfei , Xu Ning , Li Songlin , Wang Xinran , Shi Yi , Wang Fengqiu
Published: March 2021

Transition metal dichalcogenides (TMDs) are known to support complex excitonic states. Revealing the differences in relaxation dynamics among different excitonic species and elucidating the transition dynamics between them may provide important guidelines for designing novel excitonic devices. Combining photoluminescence and reflectance contrast measurements with ultrafast pump-probe spectroscopy at cryogenic temperatures, we herein study the relaxation dynamics of neutral and charged excitons in a back-gate-controlled monolayer device. Pump-probe results reveal quite different relaxation dynamics of excitonic states under different interfacial conditions: while neutral excitons have a much longer lifetime than trions in monolayer WS2, the opposite is true in the WS2/hexagonal boron nitride (h-BN) heterostructure. It is found that the insertion of the h-BN layer between the TMD monolayer and the substrate has a great influence on the lifetimes of different excitonic states. The h-BN flakes can not only screen the effects of impurities and defects at the interface but also help establish a non-radiative transition from neutral excitons to trions to be the dominant relaxation pathway, at cryogenic temperature. Our findings highlight the important role that the interface may play in governing the transient properties of carriers in 2D semiconductors and may also have implications for designing light-emitting and photo-detecting devices based on TMDs.
Percolation on coupled networks with multiple effective dependency links
Authors: Dong Gaogao , Yao Qunying , Wang Fan , Du Ruijin , Vilela André L. M. , Eugene Stanley H.
Published: March 2021

The ubiquitous coupled relationship between network systems has become an essential paradigm to depict complex systems. A remarkable property in the coupled complex systems is that a functional node should have multiple external support associations in addition to maintaining the connectivity of the local network. In this paper, we develop a theoretical framework to study the structural robustness of the coupled network with multiple useful dependency links. It is defined that a functional node has the broadest connectivity within the internal network and requires at least M support link of the other network to function. In this model, we present exact analytical expressions for the process of cascading failures, the fraction of functional nodes in the stable state, and provide a calculation method of the critical threshold. The results indicate that the system undergoes an abrupt phase transition behavior after initial failure. Moreover, the minimum inner and inter-connectivity density to maintain system survival is graphically presented at different multiple effective dependency links. Furthermore, we find that the system needs more internal connection densities to avoid collapse when it requires more effective support links. These findings allow us to reveal the details of a more realistic coupled complex system and develop efficient approaches for designing resilient infrastructure.
Thermal- and photo-induced spin crossover in the 1D coordination polymer [Fe(4-tBupy)3][Au(CN)2]2 (4-tBupy = 4-tert-butylpyridine)
Authors: García-López Víctor , Clemente-León Miguel , Coronado Eugenio
Published: March 2021

Reaction of the unidentate pyridine ligand containing a bulky t-butyl substituent with Fe2+ and [Au(CN)2]− affords a new type of spin crossover (SCO) coordination polymer in the 1D compound [Fe(4-tBupy)3][Au(CN)2]2⋅0.5H2O (1), which is formed by chains of Fe(II) complexes linked through bridging [Au(CN)2]− with three terminal 4-tBupy and one monodentate [Au(CN)2]− ligands completing the octahedral coordination around Fe(II). Longer reaction times led to the minor products [Fe(4-tBupy)2][Au(CN)2]2 (2), which presents a 2D structure more similar to that found in the other SCO compounds based on [Au(CN)2]−, and the 1D compound [Fe(4-tBupy)2(MeOH)][Au(CN)2]2 (3), in which one of the three terminal 4-tBupy found in 1 is replaced by a coordinating MeOH molecule. Magnetic measurements of 1 show an abrupt spin transition with the temperature with hysteresis and light-induced excited spin-state trapping effect. Structural analysis of 2 and 3 indicates that Fe(II) remains in the high-spin state in these compounds.
Serial reproduction reveals the geometry of visuospatial representations
Authors: Langlois Thomas A. , Jacoby Nori , Suchow Jordan W. , Griffiths Thomas L.
Published: March 2021

Significance

A primary function of human vision is to encode and recall spatial information about visual scenes. We developed an experimental paradigm that reveals the structure of human spatial memory priors in unprecedented detail. We ran a series of 85 large-scale online experiments with 9,202 participants that paint an intricate picture of these priors. Our results suggest a way to understand visuospatial representations as reflecting the efficient allocation of coding resources. In a radical departure from traditional theory, we introduce a model that reinterprets spatial memory priors as reflecting an optimal allocation of perceptual resources. We validate the predictions of the model experimentally by showing that perceptual biases are correlated with variations in discrimination accuracy.
Phyllotactic patterning of gerbera flower heads
Authors: Zhang Teng , Cieslak Mikolaj , Owens Andrew , Wang Feng , Broholm Suvi K. , Teeri Teemu H. , Elomaa Paula , Prusinkiewicz Przemyslaw
Published: March 2021

Significance

Flower heads, such as those of gerbera or sunflower, comprise hundreds of bracts and florets. They are organized into conspicuous spiral patterns with intriguing mathematical properties: For example, the numbers of left- and right-winding spirals are typically consecutive Fibonacci numbers. We examined auxin reporter lines of gerbera and combined diverse microscopy and modeling techniques to understand how these patterns develop. The critical process is the early patterning of bracts, which emerge in a specific order and guide the placement of the subsequent bracts and florets. This process, controlled by expansion and contraction of the organogenetic zone during head growth, is different from the extensively studied phyllotactic patterning in the model plantsArabidopsisand tomato.
Phytophthora lateralis (port-orford-cedar root disease).
Authors: Hansen Em
Published: March 2021

Genetics P. lateralis is in phylogenetic clade 8, defined by ITS DNA sequence (Cooke et al., 2000). The most closely related species is P. ramorum, the sudden oak death pathogen (Ivors et al., 2004). Other related species include P. hibernalis and P. foliorum; these species sometimes cross-react in molecular diagnostic tests designed for P. lateralis (Winton and Hansen, 2001). In much of Europe and in western North America, P. lateralis populations are very uniform in appearance and genetics, as expected of a clonally spread pathogen that is inbreeding or functionally asexual (McWilliams, 1999; 2000). In Taiwan and one small area of Britain, however, morphologically and genetically distinctive populations are established (Brasier et al., 2012). Isolates from Taiwan are especially variable, as might be expected of an ancestral, endemic population. In total, four distinct lineages have been described, including two from Taiwan, the invasive population found in North America and Europe, and the small UK population. Reproductive Biology P. lateralis reproduces primarily through asexual zoospores and chlamydospores (Trione, 1974; Englander and Roth, 1980). Zoospores are released from sporangia, sack-like hyphal appendages that hold about 20 zoospores each. Sporangia form in water or in saturated soil, on hyphae that grow from colonies in tree roots (or in agar). Zoospores are encased only in a membrane and are vulnerable to drying. In water they are motile with flagellae. They are chemotactic, following chemical gradients or root exudates. They remain active for about 24 hours. Zoospores encyst on root surfaces or after agitation, such as in a fast moving stream, and germinate with hyphae that may penetrate a host root and establish a new infection (Oh and Hansen, 2007). Chlamydospores are thick-walled asexual resting spores that form on hyphae in roots, foliage or in culture. They allow the pathogen to survive drying conditions, germinating with hyphae and sporangia when cool moist conditions resume (Trione, 1959). Oospores are sexual spores formed from the fusion of antheridia and oogonia. They are thick-walled and presumably function as resting spores in roots and foliage, as well as providing the population with genetic variation. They are very seldom seen in culture, however. Longevity P. lateralis survives for up to 10 years in infected root fragments in the soil (Hansen and Hamm, 1996). Population Size and Structure Populations of propagules free in the soil are small (Tsao et al., 1995). Environmental Requirements P. lateralis dies quickly from surface horizons exposed to sun as it cannot survive warm dry conditions (Hansen and Hamm, 1996). P. lateralis is active during cool, wet times of the year (Trione, 1959).
Rumex acetosella (sheep's sorrel).
Authors: Clements David R.
Published: March 2021

R. acetosella is perennial, reproducing by both creeping roots and seed. It has relatively shallow, extensive slender roots. Early growth is as basal rosettes of leaves. Leaves are 1-8 cm long, smooth, variable in shape but primarily consisting of three lobes, primary lobe is linear to egg-shaped terminating in a point; two secondary lobes appear at the base of the primary lobe and point outwards giving an arrowhead-shape appearance to the leaves which are sour in taste. It has long basal leaf stalks and short-stalked to sessile leaves on the upper stem; a membranous sheath (modified stipules) surrounds the stem above the leaf base. Multiple stems can appear from a single crown growing upright, 15-40 cm in height, slender, branching near the top to form a loose leafless panicle. Flowers are unisexual with male and female appearing on separate plants (dioecious). Males have six stamens on short filaments, females have three styles with branched stellate stigma. Flowers consist of three inner and three outer tepals, appearing red to yellowish, borne on raceme near the top of the stem. Flower stalks are jointed close to the flower. Seeds are three sided (achenes), ca. 1.5 mm in length, shiny reddish brown in colour. A reddish brown hull often adheres to the seed and is rough in texture (Buchholtz et al., 1954; Hitchcock and Cronquist, 1981; Gleason and Cronquist, 1991; Pojar and MacKinnon, 1994; Douglas et al., 1999).
Efficient soft x-ray high-order harmonic generation via dual-pulse driving lasers in the overdriven regime
Authors: Shao Renzhi , Zhai Chunyang , Zhang Yinfu , He Lixin , Zhu Xiaosong , Lan Pengfei , Lu Peixiang
Published: March 2021

We theoretically investigate the high-order harmonic generation (HHG) driven by dual-pulse lasers. The first pulse of 800 nm can create plasma in the high-density gas target. Then, the second pulse of 1800 nm is spatiotemporally reshaped by the plasma and generates soft x-ray high-order harmonics in the overdriven regime. The simulation results show that adding the first pulse can promote the phase matching of HHG in the cutoff region. As a result, a cutoff-extended HHG is achieved, which is one order of magnitude more intense than that in one pulse scheme reported previously. In dual-pulse driving lasers, the harmonic yield and the cutoff photon energy can be optimized effectively by increasing the gas pressure inside the water window region.
Density functional theory study of the mechanical behavior of silicene and development of a Tersoff interatomic potential model tailored for elastic behavior
Authors: Yoo SangHyuk , Lee Byeongchan , Kang Keonwook
Published: March 2021

Silicene, a graphene-like 2D material made from Si atoms, has been fabricated and studied for its promising applications in micro/nanoelectronics. For the reliable function of silicene devices, it is important to investigate silicene’s mechanical properties. In this study, the authors conducted density functional theory (DFT) simulations of mechanical tests of silicene and investigated the elastic modulus and mechanical response such as structural transformation. In addition, the authors optimized the Tersoff potential parameters using a gradient-based minimization with a grid search method in hyperdimensional parameter space, to match the DFT calculation results in the elastic regime. With the new parameter set, the elastic moduli of silicene in the zigzag (ZZ) and armchair (AC) directions were computed with molecular statics (MS) simulations and compared with those of other Si interatomic potential models and DFT results. In addition, uniaxial tensile tests along the ZZ and AC directions were performed to examine how far the Tersoff model is transferable with our new parameter set to describe the nonlinear mechanical behavior of silicene. The results of uniaxial tensile tests suggest that the angle penalty function in the Tersoff model needs to be modified and that the stress–strain curve predicted with this modification shows improvement compared to the original function.
Barrier height tuning by inverse sputter etching at poly-Si/4H-SiC heterojunction diodes
Authors: Triendl F , Pfusterschmied G , Schwarz S , Pobegen G , Konrath J P , Schmid U
Published: March 2021

Si/4H-SiC heterojunction diodes (HJDs) are fabricated by applying Ar+ inverse sputter etching (ISE) of the 4H-SiC substrate prior to Si deposition. A subsequent annealing step was used to crystallize the sputter deposited amorphous Si. Numerical simulations and experiments were conducted to investigate the amorphization depth and etch rate of low energy Ar+ ions on the Si-face of 4H-SiC. Electrical characterization of the HJDs showed a strong influence of the ISE treatment in both n and p-type Si contacts compared to untreated diodes. The ISE power, as well as the ISE time can be tailored to adjust the Schottky barrier height (SBH) in a certain range, by simultaneously improving the device ideality for most ISE parameters compared to diodes without any ISE treatment. In addition, the homogeneity of the SBHs is improved, resulting in less variation over temperature and between different samples. The formation of a smooth Si–SiC transition region instead of a sharp interface is found after both ISE treatment and thermal annealing.
Threshold voltage shift induced by intrinsic stress in gate metal of AlGaN/GaN HFET
Authors: Yazdani Hossein , Chevtchenko Serguei , Ostermay Ina , Würfl Joachim
Published: March 2021

Mechanical stress/strain is altering the charging properties of piezoelectric materials. For AlGaN and GaN heterostructures, this phenomenon has been described theoretically (Ambacher et al 2000 J. Appl. Phys.
87 334–44). Recently it was shown that a mechanically stressed SiN
x
passivation layer may produce local strain in the AlGaN/GaN layers underneath the gate at certain conditions. This results in a threshold voltage (V
th) shift (Osipov et al 2018 IEEE Trans. Electron Devices
65 3176–84). It is therefore straightforward to also investigate the influence of an intrinsically stressed gate metal on the device characteristics. In this study, AlGaN/GaN HFETs were fabricated on nominally identical wafers with variations of intrinsic stress in the gate metallization and in the first passivation. It is verified that the built-in mechanical stress of the gate metal can shift the threshold voltage. In detail we varied the intrinsic stress of both the first passivation layer (SiN
x
) and the gate metallization (Ir) by about 1 GPa. These variations result respectively in 0.65 and 0.20 V threshold voltage shift. We have additionally analyzed the thermal stability of SiN
x
and iridium films with respect to their mechanical properties and the resulting threshold voltage shift.
Wave processes in silicon samples with nickel impurities arising at pulsed hydrostatic pressure
Authors: Khamidov Rustam , Mamatkarimov Odiljon
Published: March 2021

The paper considers relaxation–vibrational processes in silicon samples with nickel impurities, which create deep energy levels in its forbidden zone, during pulsed hydrostatic compression. The experiments were carried out under the direct influence of hydrostatic compression. Theoretical calculations showed that an increase in the temperature of the studied samples during dynamic compression is mainly associated with a change in the temperature of the surrounding liquid. The resulting differential equation shows that at dynamic pressure (at high rates of increase in hydrostatic pressure), wave thermodynamic processes arise. It was experimentally found that in silicon samples with deep impurity levels at pulsed hydrostatic pressure, in addition to the temperature effect, vibration-wave effects also appear. We have also shown experimentally that the relaxation part of the relative change in the current strongly depends on the degree of compensation. With weak compensation, the relaxation part is almost absent. And with strong compensation, the relaxation part of the relative change in compensated samples n-Si  is noticeably higher than in overcompensated samples p-Si .
Dynamical inflection point inflation
Authors: Bai Yang , Stolarski Daniel
Published: March 2021

We provide a mechanism to obtain multiple inflection points for the inflaton potential based on the Coleman-Weinberg potential. The key ingredient is the existence of zeros of the inflaton quartic coupling beta function, which can be simply realized by a sign change of a gauge coupling beta function at a massive threshold scale in gauge-Yukawa models. A universal inflaton potential emerges for a wide range of models and can accommodate the observational data in the small-field inflation scenario. While the ratio of tensor over scalar amplitudes is predicted to be small, the running of the scalar spectral index, αs, has branches with both positive and negative values. The positive branch with αs ≳ 0.002 will be tested by the coming cosmic microwave background observations.
Application of XGBoost Algorithm in The Detection of SARS-CoV-2 Using Raman Spectroscopy
Authors: Zeng Wandan , Wang Qi , Xia Zhiping , Li Zhiping , Qu Han
Published: March 2021

The novel coronavirus (SARS-CoV-2), which was first discovered in late 2019 and rapidly spread to many countries around the world in a short period of time, is highly contagious and poses a significant threat to global public safety. How to quickly and efficiently detect whether a human is infected by the novel coronavirus is a crucial step in dealing with this public health emergency. Therefore, the collected Raman spectral data are preprocessed by normalization, smoothing denoising and feature extraction in this paper. A novel coronavirus detection method based on XGBoost and Raman spectroscopy is proposed. The experiments demonstrated the feasibility and accuracy of the method in the detection of novel coronavirus with an accuracy of 93.548%.
Prediction of 18Ni300 laser cladding topography based on back-propagation neural network and particle swarm optimization
Authors: Xiawei LE , Jingbin HAO , Qingdong MENG , Fangtao HU , Hao LIU , Haifeng YANG , Xinhua LIU
Published: March 2021

Laser cladding is an advanced new surface manufacturing technology, which has a wide range of applications in production, repair and surface strengthening of parts in many industries. Aiming at the problem that the forming quality cannot be guaranteed after the Q235 substrate, a full factorial design method was used to conduct the experiments. Then a multiple linear regression model was established to obtain the functional expression between the cladding layer morphology parameters (cladding layer height, cladding layer width and dilution ratio) and laser power, scanning speed and powder feeding rate. And then back-propagation neural network (BPNN) and particle swarm optimization (PSO) were used to establish prediction models between the morphology quality of the laser cladding layer and the process parameters. Finally, the prediction results of two models were compared with the measured value, respectively. The results showed that the average relative errors of the multiple linear regression model for the prediction of cladding layer width, height, and dilution ratio were 4.525%, 6.018%, and 5.659%, respectively, while the average relative errors predicted by the optimized neural network model were 3.177%, 7.242%, 4.679%, respectively. The goodness of fit(R2) in linear regression model were 0.8034, 0.8407, and 0.8297 respectively, while the R2 in PSO-BPNN model were 0.8134, 0.8336, and 0.9576 respectively. In this paper, the feasibility of the PSO-BPNN model in theory and practice was verified, and it provided theoretical guidance for the realization of the subsequent laser cladding closed-loop control system.
Visualization of google mobility data for provinces in Indonesia using seaborn python programming package
Authors: Aurachman R
Published: March 2021

One important data needed in handling the COVID-19 pandemic is human mobility data. Based on mobility data provided by Google, analysis can be done as a basis for decision making. This research produces several visualization methods that provide insight to decision makers. Visualization is done using Python Programming.
Automatic braking system using fuzzy logic method
Authors: Rizianiza I , Shoodiqin D M
Published: March 2021

This research is design an autonomous car control system that can reduce the rate of traffic accident. Car prototype is designed by using Fuzzy Logic Control. Fuzzy logic is as main component of artificial intelligence has significantly influence the design controlled system. Fuzzy logic system is integrated with the arduino Mega 2560 microcontroller as the central control car prototype. In this paper, the Fuzzy logic used Mamdani method and 28 rule base. The fuzzy system was made based on fuzzy mechanism which are fuzzification, inference and defuzzification. Fuzzy logic has a variable input and output variables. Input variables used in this research is the distance between car and obstacle; the speed of car prototype and the output variable is the brake angle. The test is done with 5 variations of distance that is 100 cm, 125 cm, 150 cm, 175 cm, and 200 cm and two variations of speed that are 54 cm/s, and 63 cm/s. The test results showed that the prototype of the car was able to stop with a range of 22 cm - 35 cm from obstacle. The highest deceleration value at the speed of 63 cm/s is - 49.22 cm/s2 and the accuracy of braking on a system that has been designed is between 99.91% -100%.
Decreasing corrosion rate of clean water distribution pipes using bio-inhibitor
Authors: Mulyaningsih N , Ika D
Published: March 2021

Iron pipes that distribute clean water to the community often experience corrosion and leakage. It causes dirt in the soil to enter the water flow and can cause health problems. Therefore, to provide good quality water to the community, it is necessary to control pipes’ corrosion. In previous research, there has been much discussed the bio-inhibitor corrosion in pipes, but very few have tested corrosion under real environmental conditions. Thus, this research aims to analyze the amount of reduction in the corrosion rate of clean water distribution pipes using real environmental conditions using bio-inhibitors. This study employed the same bio-inhibitor but different concentration variations. The inhibitor used came from lime peel waste with various concentrations of 120, 220, and 320 ppm. Corrosion rate testing used Potentiodynamic methods. The results showed that using a bio-inhibitor of 320 ppm could reduce the pipe’s corrosion rate by 90.7%. Before being given the bio-inhibitor, the corrosion rate was 34.690 mpy, and after being given the bio-inhibitor, it decreased to 3,225 mpy. This study’s results will later be useful for the community to utilize the bio-inhibitor as an alternative to controlling corrosion in pipes.
Students’ perspective: instructional design and technology that should be done in vocational teacher education
Authors: Yudantoko A
Published: March 2021

The development of science and technology, the industrial revolution 4.0, the 21st century required skills, the ASEAN Economic Community, and the characteristic of 21st-century students bring significant effects for educational programs for preparing appropriate skills for students to face those challenges. Instructional design that should be done in the teaching and learning processes in the classroom is one of the crucial things that have high impacts on students’ success in mastering subject matter. This study aims to describe important things of instructional design and technology that students want to be implemented in their learning activities. This study is a descriptive survey research with exploratory sequential mixed-methods data analysis. The data was collected by conducting focus group discussions (FGD) and questionnaires with first-year students in 2 classes of automotive vocational teacher education in Yogyakarta State University. The results of this study are (1) having a structured program in an online platform with specific preferred learning materials before classroom activities for preparing needed background knowledge, (2) having discussions for exercising high order thinking skills in classroom activities, and (3) having checking understanding and discussion forum program in an online platform.
Human daily activities recognition using decision tree
Authors: Nurwulan N R , Selamaj G
Published: March 2021

Decision tree is a supervised classifier that is easy to understand. There are various decision tree methods. This study aimed to compare the performance of decision tree methods in human activity recognition using acceleration and jerk data. The subjects performed human activity daily living, namely walking on a flat surface, walking upstairs, walking downstairs, sitting, standing, and lying down. The features were grouped into three categories: acceleration features, jerk features, and combined features of acceleration and jerk. The evaluation was done using Random Forest, J48, Logistic Model Tree, Reduced Error Pruning Tree, Decision Stump, Random Tree, and Hoeffding Tree. The results showed that Random Forest outperformed the other classifiers with acceleration features performed better than the jerk features. However, the combined acceleration and jerk features yielded the highest accuracy. In conclusion, Random Forest is the best decision tree technique in recognizing the pattern in human activity.
A model of serious game-based learning media on the basic material of statics and dynamics
Authors: Zen A. S. , Nurhadi D. , Widiyanti
Published: March 2021

Purpose of this paper is to explain a serious game based learning media model on the basic material of statics and dynamics for students of mechanical engineering education, Universitas Negeri Malang. This study carried out by research and research (R&D) with the waterfall research model. In the first stage, the design of this model is based on a low understanding of the basic material of statics and dynamics. Through discussions with the lecturers of the course, the authors developed this design to be prepared for trials for mechanical engineering education students at Universitas Negeri Malang. Furthermore, this media model contains two menus, namely materials and quizzes. The material consisted of unit material and mathematics. Meanwhile, the quiz material consisted of four quizzes with Bloom’s taxonomy levels. Through this media model, it is concluded that it will assist students in understanding basic statics and dynamics in the field of mechanical engineering.
Sealed trash bin with innovative design technology and environmental education
Authors: Peng L H , Wang Y W , Siswanto I
Published: March 2021

With the advancement of the times, science and technology have become more developed, and a variety of items are manufactured quickly, resulting in invisible waste under over-manufacturing. Waste of resources has become a burden on the environment [1], although people’s quality of life The improvement is accompanied by many garbage disposal problems. Although the application of traditional trash cans can improve the mess of the environment in a short time, it cannot effectively prevent the stench emitted by garbage corruption and hygienic infection problems caused by weather changes. In this study, the design improvement of the traditional treaded trash can and the sealing machine seen in daily life was used to analyze the advantages and disadvantages of the creative design of the trash can and the material needs of designers from all over the country and then complete the product that meets the universal system. We also hope that this technology design Can be integrated into environmental education and bring new practical ideas.
Android application innovation as the indonesian basic spices learning media
Authors: Wulandari D R , Handayani T H W
Published: March 2021

Education is a significant aspect in the development of a nation. Currently, Indonesia is entering the industrial revolution 4.0 which brings a great impact in various fields, including the field of education as the learning process must continuously evolve by embracing the applications of digital media. However, the learning process in formal education at the moment in Indonesia, especially in vocational high school, tends to use conventional-type media and methods. As a result, students are less enthusiastic and experience difficulties in understanding the lessons and absorbing the materials in the class. For this reason, this study develops a learning media innovation that addresses current student needs by developing an Android application innovation. The method used was the research and development (R&D) method, while the objective of the study was to examine the development process and feasibility of the Android application learning media for Indonesian Basic Spices. The research findings suggest that (1) the development process of the application uses the 4D research method (define, design, develop, and disseminate) and results in a 26.25 MB application using the Adobe Animate software.
Analysis of the need for the development of learning media for IOT-Based smart building installation systems
Authors: Salsabila A , Khairudin M
Published: March 2021

Learning media is a means of learning for students that can provide a real picture of real work that has a high risk if it is carried out directly. Learning media has a role in facilitating students to be able to experience it directly with minimal risk from a practicum. Analyzing the need for making learning media is very important for the development of real learning media. This study aims to: (1) Determine the need for the development of learning media for IOT-based smart building installation systems in Vocational High School (VHS); (2) Analyzing the needs used in the development of learning media for IOT-based smart building installation systems in VHS. The results showed that the things needed in developing IOT learning media were seen from the technology used in the form of (1) Software based on media interaction with the internet using a visual studio; (2) Arduino Uno, temperature sensor device, ESP8266, gas sensor and light sensor are needed as hardware to reflect building capabilities; (3) The cloud computing system uses spread sheets to store data; (4) Internet network for uploading and downloading data. In its implementation, a needs analysis for the development of instructional media is needed so that in the later development process the media is developed appropriately and on target. The results of research and development research using the ADDIE method need the development of learning media for IOT-based smart building installation systems in vocational high schools to improve the learning abilities of students.
Effect of Convection on the Distortion of Spatial Self-Phase Modulation Pattern in Graphene Dispersions
Authors: Ma Lingyue
Published: March 2021

Effect of convection on the distortion of spatial self-phase modulation(SSPM)pattern in graphene dispersions has been investigated. When a Gaussian laser beam is transmitted through grapheme dispersions, the interference pattern in the far-field first forms a series of circular rings, but the upper half of the rings collapses rapidly after a period of time, forming a stable distorted pattern. Experimental results show that thermal convection effect plays a dominant role for the distortion of the SSPM pattern. In the absence of convection in the beam cross section, the interference rings are circularly symmetric rings. In the presence of convection in the beam cross section, the interference rings exhibit circularly asymmetric rings. Theoretical analyses have then been given for the reason of the interference rings distortion. Convection can effectively change the spatial symmetry distribution of polarized graphene sheets and non-linear refractive index in the beam cross-section, thus making the interference rings distortion based on the spatial self phase modulation. It is concluded that the distortion of the interference pattern is originated from the thermal convections induced by laser heating.
Two-dimensional Phase-field Simulation of Pore Evolution in High Temperature Self-lubrication Composites
Authors: Han Tiantian , Zhou Changxiu , Kong Dejun
Published: March 2021

The phase field model was established based on the free energy function method to simulate the evolution process of microporous matrix. High temperature self-lubricating microporous matrix was prepared by powder metallurgy method, then its porosity was measured under different pore forming agent ratio and addition amount, in order to verify the phase field model. The results show that the simulation value of porosity by phase field method is basically consistent with the experimental value, and the phase field model can be used to simulate the effect of pore forming agent on the pore evolution process of matrix.