bluuebunny/crossref_metadata_2025 huggingface dataset:
Epistemic stance in the climate change debate
Authors: Biri Ylva
Published: October 2022

This study analyses epistemic stance in social media climate change discussions, contributing to our understanding of how factuality and likelihood are evaluated in climate change discourse. Using a corpus of 1.2 million words, the paper compares the frequencies of epistemic stance in climate change sceptic and climate change proponent discourses on two social media platforms, Twitter and Reddit. Based on the quantitative analysis, the paper argues that both platform and climate change beliefs influence register in terms of epistemic stance. Overall, Reddit uses more epistemic stance markers than Twitter. Sceptics use less hedging of likelihood and more lexis evaluating the factuality and reliability of their opponents. The interpersonal functions of epistemic stance are shown to be associated with different platform uses and affordances and with the different goals, worldviews, and concerns of the factions. The study thus calls for further linguistic comparison of platforms and different factions within the platforms.
Two-Dimensional Electron Gas in MoSi2N4/VSi2N4 Heterojunction by First Principles Calculation
Authors: Gao Ruiling , Liu Chao , Fang Le , Yao Bixia , Wu Wei , Xiao Qiling , Hu Shunbo , Liu Yu , Gao Heng , Cao Shixun , Song Guangsheng , Meng Xiangjian , Chen Xiaoshuang , Ren Wei
Published: October 2022

Van der Waals (vdW) layered two-dimensional (2D) materials, which may have high carrier mobility, valley polarization, excellent mechanical properties and air stability, have been widely investigated before. We explore the possibility of producing a spin-polarized two-dimensional electron gas (2DEG) in the heterojunction composed of insulators MoSi2N4 and VSi2N4 by using first-principles calculations. Due to the charge transfer effect, the 2DEG at the interface of the MoSi2N4/VSi2N4 heterojunction is found. Further, for different kinds of stacking of heterojunctions, lattice strain and electric fields can effectively tune the electronic structures and lead to metal-to-semiconductor transition. Under compressive strain or electric field parallel to c axis, the 2DEG disappears and band gap opening occurs. On the contrary, interlayer electron transfer enforces the system to become metallic under the condition of tensile strain or electric field anti-parallel to c axis. These changes are mainly attributed to electronic redistribution and orbitals’ reconstruction. In addition, we reveal that MoSi2N4/VSi2N4 lateral heterojunctions of armchair and zigzag edges exhibit different electronic properties, such as a large band gap semiconductor and a metallic state. Our findings provide insights into electronic band engineering of MoSi2N4/VSi2N4 heterojunctions and pave the way for future spintronics applications.
The influence of liquid conductivity on pulsed discharge generated by a vertical falling liquid electrode device
Authors: Qi Zhihua , Wang Xi , Xia Yang , Zhao Zhiguo , Liu Dongping , Shi Shuhui , Ji Xiaorui , Zhou Zhenyu
Published: October 2022

A novel atmospheric gas–liquid discharge device has been designed in this study to generate discharge directly around the vertical falling liquid column. The device is made up of a quartz tube, an H.V. electrode attached to the outer wall of the quartz tube, and a vertical falling liquid column acting as the liquid ground electrode in the quartz tube`s internal center. An ICCD camera and a 2D axisymmetric numerical modeling are used to analyze the temporal-spatial evolution of the pulsed discharge around the liquid electrode. The results of the experiment and simulation indicate that the propagation and sustaining time of the discharge are strongly dependent on applied voltage and liquid electrode conductivity. It is found that there is no discharge observed around the liquid electrode with a conductivity of 0.05 mS cm−1. As the conductivity of the liquid electrode increases, the electric field applied in the gas phase increases. When the conductivity is greater than 0.05 mS cm−1, the discharge is initiated around the intermediate region of the liquid electrode, then develops upwards and downwards along the liquid electrode. The discharge sustaining time increases with the increase of the conductivity and applied voltage. When the liquid electrode is replaced by the stainless-steel electrode, it is discovered that the discharge sustaining time of the stainless-steel electrode is lower than that of the liquid electrode at the same applied voltage. Analysis suggests that the prolonged discharge sustaining time is caused by the gas capacitance that is increased by water vapor released from the liquid electrode. The simulation results indicate that the discharge around the liquid electrode is constrained to the cone-shaped distribution by the non-uniform electric field around the liquid electrode when the conductivity increases to 200 mS cm−1 .
Quenching of bright and dark excitons via deep states in the presence of SRH recombination in 2D monolayer materials
Authors: Szmytkowski Jȩdrzej
Published: October 2022

Two-dimensional (2D) monolayer materials are interesting systems due to an existence of optically non-active dark excitonic states. In this work, we formulate a theoretical model of an excitonic Auger process which can occur together with the trap-assisted recombination in such 2D structures. The interactions of intravalley excitons (bright and spin-dark ones) and intervalley excitons (momentum-dark ones) with deep states located in the energy midgap have been taken into account. The explanation of this process is important for the understanding of excitonic and photoelectrical processes which can coexist in 2D materials, like transition metal dichalcogenides and perovskites.
Unified theory of spin and charge in a ferromagnet
Authors: Tchernyshyov Oleg
Published: October 2022

We derive a unified theory of spin and charge degrees of freedom in a ferromagnet. The spin-transfer torque and spin electromotive force are examined from the coarse-grained perspective of collective coordinates. The resulting equations of motion reflect a balance of conservative, gyroscopic (Berry-phase), and dissipative forces. We then expand the space of collective coordinates by adding the electric charge. The adiabatic spin-transfer torque and spin electromotive force (emf) turn out to be a gyroscopic force; their nonadiabatic counterparts are a dissipative force.
Lattice distortions and the metal–insulator transition in pure and Ti-substituted Ca3Ru2O7
Authors: Petkov V , Rao T Durga , Zafar A , Abeykoon A M Milinda , Fletcher E , Peng J , Mao Z Q , Ke X
Published: October 2022

We report pair distribution function studies on the relationship between the metal–insulator transition (MIT) and lattice distortions in pure and Ti-substituted bilayer Ca3Ru2O7. Structural refinements performed as a function of temperature, magnetic field and length scale reveal the presence of lattice distortions not only within but also orthogonal to the bilayers. Because of the distortions, the local and average crystal structure differ across a broad temperature region extending from room temperature to temperatures below the MIT. The coexistence of distinct lattice distortions is likely to be behind the marked structural flexibility of Ca3Ru2O7 under external stimuli. This observation highlights the ubiquity of lattice distortions in an archetypal Mott system and calls for similar studies on other families of strongly correlated materials.
Design and construction of a lab-made calorimetric system for specific loss power (SLP) measurements in suspensions of magnetic nanoparticles
Authors: Suárez Gómez S E , Velásquez A A , Velásquez Salazar A A , Ospina A M
Published: October 2022

The specific loss power (SLP) is a figure of merit in nanomagnetism, which allows to classify systems of magnetic nanoparticles (MNPs) according to their capability to dissipate heating power in response to the energy absorbed from an alternating magnetic field (AMF) at radiofrequencies. SLP magnitude is relevant in biological applications of MNPs, such as nanomedicine, where the thermal energy released by these nanostructures can be used to produce apoptosis in cancer cells, becoming a promising alternative for the treatment of malignant tumors. In this work we present details of the design and construction of a lab-made electromagnetic system to perform SLP measurements in systems of MNPs. The system is composed by an actuation stage, which generates the AMF to excite the sample, a thermal insulation stage between the sample and its surroundings, and two sensing stages: the first one for measuring the magnetic field applied to the sample and the second one for measuring the changes of temperature of the sample. The system developed allows to reach AMFs around 7.7 kA m−1 in the center of the actuation coil, operating at 260 kHz and with a power consumption less than 150 W. The architecture of the system allows the automatization and control of SLP measurements from remote places through the IEEE 488 bus available in the power source and a graphic interface developed in LabVIEW software, which allows to visualize temperature versus time measurements, control the magnetic field amplitude and store the data in a public folder available in the cloud. Some results are presented, where the system is employed to measure the SLP of a colloidal suspension of MNPs of maghemite (γ-Fe2O3) stabilized with sodium polyacrylate. The results obtained show a satisfactory performance of the device to measure the SLP of samples of MNPs for different purposes.
A 3D radius compensation method to reduce the influence of probe fluctuation error in blade space curve measurement
Authors: Wang Xingzhao , Zhang Xu , Jia Guangjie , Cao Jianbin
Published: October 2022

In the contact measurement of the coordinate measuring machine, the space curve cannot obtain the third-dimension information of its compensation vector by itself. Moreover, the fluctuation error of the probe will cause the unknown spatial offset of the contact point of the curve, making it more difficult to obtain the third-dimensional information of the compensation vector. A three-dimensional radius compensation method based on iterative third-dimensional information is proposed in this paper. The distance value between the intersection point and the compensation point is used as the convergence condition to approximate the offset contact point. The simulation test results show that the error accuracy of radial parameters is 0.1 μm and the error accuracy of Z-direction parameters is 1 μm when only Z-direction fluctuation error is considered. The real machine test results show that this method is closer to the actual situation than the two-dimensional radius compensation method.
Sparse representation and modified density peak clustering-based state identification for multimode processes
Authors: Wang Zhaojing , Chen Bin , Zheng Ying , Wang Yang , Yan Xiaoyun
Published: October 2022

Industrial processes with high-dimensional data are generally operated with mixed normal/faulty states in different modes, making it difficult to automatically and accurately identify the faults. In this paper, a state identification framework is proposed for multimode processes. First, a key variable selection approach is presented based on sparse representation to eliminate redundant variables. Then, modified density peak clustering is proposed to identify different states, in which a distance measurement with a time factor is constructed to select all the possible cluster centers. Then, the sum of squared errors-based approach is developed to determine the optimal cluster centers automatically. Further, considering that the mode attributes may be mixed with the fault attributes, a two-step ‘coarse-to-fine identification’ strategy is designed to precisely identify the modes and the faults in each mode. Finally, three cases including a numerical simulation, Tennessee Eastman benchmark process and an actual semiconductor manufacturing process are presented to show the feasibility of the proposed method.
Modification of the Johnson–Cook model for metal at a wide range of strain rates and application in the dynamic response of honeycomb panels
Authors: Li Shuangbei , Su Quanfu , Wang Xiangyu , Wu Yuan , Zhao Xuan , Chang Yanjun
Published: October 2022

In this paper, the H/V-Johnson Cook (JC)/Cowper Symonds (CS) dynamic constitutive relation suitable for a wide range of strain rates is proposed. Based on the experimental data in the existing literatures, the parameters of the H/V-JC/CS constitutive model for metal materials are calibrated by using the global optimization algorithm, which has high accuracy, convenient application, and is unlimited in number of parameters. The obtained parameters do not depend on the initial value and are the global optimal combination. The corresponding ABAQUS visual user material subroutine is compiled and imported into the finite element analysis for the dynamic response of the honeycomb panel structure. The influence of geometric parameters on the energy absorption effect of honeycomb panels under impact load is explored. The research shows that the proposed H/V-JC/CS constitutive model can well describe the mechanical behavior of various metals in a wide range of strain rates under impact load, and can be used in ABAQUS dynamic explicit environment. It provides a high-precision engineering application analysis model for metal structures under dynamic load.
Reaction mechanism of core–shell Al@SiO2 nanoparticles from molecular dynamics simulations
Authors: Zhang Jinping , Wang Erping , Yu Chunlai , Xie Jingpei , Tang Cuiming , Jia Yu
Published: October 2022

Nanothermites play an important roles in both civil and military fields. In this paper, using molecular dynamics simulations with reactive force field (ReaxFF), we study the thermally induced reactions of core–shell Al@SiO2 nanoparticles to elucidate the underlying reaction mechanism between Al and a metallic oxide. Core–shell Al@SiO2 nanoparticles undergo a four-stage explosive reaction after being heated to the ignition temperature. They are, in sequence: (i) Heat is released from the core–shell interface to Al core, and Al core begins to melt. (ii) The melted Al core accelerates the redox exothermic reaction, producing a pure Si shell. (iii) The Si shell moves towards the center of the system under electric field induction, and the distorted AlnO (n = 4, 5) clusters are ejected from the system’s surface. (iv) The detonation of the nanoparticles, and the formation of final products. Notably, the electric-field-induced Al atoms diffuse faster than the O atoms throughout the reaction. Our findings provide a reference guide for the reactions of nanothermites.
Enhanced piezoelectric response in BTO NWs-PVDF composite through tuning of polar phase content
Authors: Hazra Snehamoyee , Ghatak Ankita , Ghosh Arnab , Sengupta Subhamita , Raychaudhuri A K , Ghosh Barnali
Published: October 2022

We have fabricated a flexible, environment friendly piezoelectric nanogenerator (PENG) based on the ferroelectric Polyvinylidene fluoride (PVDF) composite incorporated with Barium titanate (BaTiO3) nanowires (NWs) of piezoelectric coefficient d
33 = 308 pm V−1. The single-layered PENG can deliver output power density of 10 μW cm−2 and an output voltage of 2 V with a nominal mechanical load of 1 kPa. BaTiO3 (BTO) NWs of different concentrations were incorporated into PVDF to tune the polar phase content, internal resistance, and optimize the output power. We show that there exists a critical value of BTO NWs loading of 15 wt%, beyond which the piezoelectric energy harvesting characteristics of the PVDF nanocomposites decrease. The oxygen vacancies present in the BTO NWs surface attract the fluorine ions of PVDF chain and favour the formation of β phase. The enhanced value of dielectric constant and dielectric loss of BTO-PVDF samples in the low frequency region suggest strong interfacial polarization in the composite system. The fabricated PENG can charge a super-capacitor up to 4 V within 35 s. The origin of the high power output from the BTO (15 wt%)-PVDF composite is attributed to the combined effect of enhanced polar phase content, strong interfacial polarization, and reduced internal resistance. This study provides an effective pathway in enhancing the performance of BTO-PVDF based piezoelectric energy harvesters.
Non-invasive blood pressure estimation combining deep neural networks with pre-training and partial fine-tuning
Authors: Meng Ziyan , Yang Xuezhi , Liu Xuenan , Wang Dingliang , Han Xuesong
Published: October 2022

Objective. Daily blood pressure (BP) monitoring is essential since BP levels can reflect the functions of heart pumping and vasoconstriction. Although various neural network-based BP estimate approaches have been proposed, they have certain practical shortcomings, such as low estimation accuracy and poor model generalization. Based on the strategy of pre-training and partial fine-tuning, this work proposes a non-invasive method for BP estimation using the photoplethysmography (PPG) signal. Approach. To learn the PPG-BP relationship, the deep convolutional bidirectional recurrent neural network (DC-Bi-RNN) was pre-trained with data from the public medical information mark for intensive care (MIMIC III) database. A tiny quantity of data from the target subject was used to fine-tune the specific layers of the pre-trained model to learn more individual-specific information to achieve highly accurate BP estimation. Main results. The mean absolute error and the Pearson correlation coefficient (r) of the proposed algorithm are 3.21 mmHg and 0.919 for systolic BP, and 1.80 mmHg and 0.898 for diastolic BP (DBP). The experimental results show that our method outperforms other methods and meets the requirements of the Association for the Advancement of Medical Instrumentation standard, and received an A grade according to the British Hypertension Society standard. Significance. The proposed method applies the strategy of pre-training and partial fine-tuning to BP estimation and verifies its effectiveness in improving the accuracy of non-invasive BP estimation.
Engineering the insulator-to-metal transition by tuning the population of dopant defects: first principles simulations of Se hyperdoped Si
Authors: Debernardi Alberto
Published: October 2022

Chalcogens are extremely promising for hyperdoping Si because of their superior electronic properties with respect to group V elements of the periodic table traditionally employed as dopants. Within the framework of plane-wave pseudopotential techniques we computed the formation energy of different types of defects formed by dopants in Se-hyperdoped Si, as a function of the dopant concentration. Moreover, we studied the possibility of tailoring the electronic properties of the system, by tuning the probability that each type of defect can form. In particular, by using supercells exceeding thousands of atoms we characterized the double impurity band (IB) structure of

S
e

S
i

3

−

V

S
i

complex, formed by a Si vacancy surrounded by three Se, which presents a shallow metallic IB and a deep insulating IB in the Si band gap, thus allowing sub-threshold photon absorption, and suggesting that a significant improvement in the performance of Se-hyperdoped Si as an infrared detector, can be achieved by increasing the population of

S
e

S
i

3

−

V

S
i

complexes. Our findings relate the range of microscopic sizes in which dopants can diffuse to the population of different types of complexes, revealing the possibility of engineering the critical concentration at which the insulator-to-metal transition occurs by varying the diffusion length of the dopant. These results pave the way for the exploitation of Se-hyperdoped Si as a building block in newly conceived ultra-scaled nano-electronic devices, infra-red detectors and intermediate-band photovoltaic applications.
A semi-active toroidal TLCD for multidirectional vibration reduction of structures
Authors: Zhang Jian , Ding Hao , Wang Jin-Ting
Published: October 2022

The toroidal tuned liquid column damper (TTLCD) is a recently developed device to mitigate multidirectional vibrations of structures. In this paper, a semi-active TTLCD (S-TTLCD), which can automatically identify the frequency change of structures and tune its natural frequency correctly by adjusting the liquid level, is proposed. The feasibility of the S-TTLCD is proved experimentally. The impacts of several important parameters, such as the multi-stage stiffness variation of structure, the pump flow rate, the mass ratio, and the damping ratio, on the performance of the S-TTLCD are evaluated numerically. The results confirm that the S-TTLCD is well adaptive and reduces the structural response more significantly when the structural natural frequency changes, compared to the passive TTLCD.
Superconductivity, generalized random phase approximation and linear scaling methods
Authors: Peotta Sebastiano
Published: October 2022

The superfluid weight is an important observable of superconducting materials since it is related to the London penetration depth of the Meissner effect. It can be computed from the change in the grand potential (or free energy) in response to twisted boundary conditions in a torus geometry. Here we review the Bardeen–Cooper–Schrieffer mean-field theory emphasizing its origin as a variational approximation for the grand potential. The variational parameters are the effective fields that enter in the mean-field Hamiltonian, namely the Hartree–Fock potential and the pairing potential. The superfluid weight is usually computed by ignoring the dependence of the effective fields on the twisted boundary conditions. However, it has been pointed out in recent works that this can lead to unphysical results, particularly in the case of lattice models with flat bands. As a first result, we show that taking into account the dependence of the effective fields on the twisted boundary conditions leads in fact to the generalized random phase approximation. Our second result is providing the mean-field grand potential as an explicit function of the one-particle density matrix. This allows us to derive the expression for the superfluid weight within the generalized random phase approximation in a transparent manner. Moreover, reformulating mean-field theory as a well-posed minimization problem in terms of the one-particle density matrix is a first step towards the application to superconducting systems of the linear scaling methods developed in the context of electronic structure theory.
Strong surface termination dependence of the electronic structure of polar superconductor LaFeAsO revealed by nano-ARPES
Authors: Jung Sung Won , Rhodes Luke C , Watson Matthew D , Evtushinsky Daniil V , Cacho Cephise , Aswartham Saicharan , Kappenberger Rhea , Wurmehl Sabine , Büchner Bernd , Kim Timur K
Published: October 2022

The electronic structures of the iron-based superconductors have been intensively studied by using angle-resolved photoemission spectroscopy (ARPES). A considerable amount of research has been focused on the LaFeAsO family, showing the highest transition temperatures, where previous ARPES studies have found much larger Fermi surfaces than bulk theoretical calculations would predict. The discrepancy has been attributed to the presence of termination-dependent surface states. Here, using photoemission spectroscopy with a sub-micron focused beam spot (nano-ARPES) we have successfully measured the electronic structures of both the LaO and FeAs terminations in LaFeAsO. Our data reveal very different band dispersions and core-level spectra for different surface terminations, showing that previous macro-focus ARPES measurements were incomplete. Our results give direct evidence for the surface-driven electronic structure reconstruction in LaFeAsO, including formation of the termination-dependent surface states at the Fermi level. This experimental technique, which we have shown to be very powerful when applied to this prototypical compound, can now be used to study various materials with different surface terminations.
Spatially resolved spectroscopy of alkali metal vapour diffusing inside hollow-core photonic crystal fibres
Authors: Häupl Daniel R , Weller Daniel , Löw Robert , Joly Nicolas Y
Published: October 2022

We present a new type of compact and all-glass based vapour cell integrating hollow-core photonic crystal fibres. The absence of metals, as in a traditional vacuum chamber and the much more compact geometry allows for fast and homogeneous heating. As a consequence we can fill the fibres on much faster timescales, ranging from minutes to hours. Additionally the all-glass design ensures optical access along the fibre. This allows live monitoring of the diffusion of rubidium atoms inside the hollow-core by measuring the frequency-dependent fluorescence from the atoms. The atomic density is numerically retrieved using a five-level system of Bloch-equations.
Ultraviolet metalens and metalens array of focused vortex beams
Authors: Zhang Jinping , Wang Yan , Yuan Huan , Wang Zehao , Deng Yang , Huang Chengzhi , Wu Jiagui , Yang Junbo
Published: October 2022

The solar-blind ultraviolet (UV) wavelength is particularly interesting within the range of 200 nm–300 nm. Here, we propose a focusing metalens, focusing vortex beam (VB) metalens and metalens array that specifically work in the UV band to focus a beam or VB. Firstly, a high numerical aperture (NA) focusing metalens working at a wavelength of 214.2 nm was designed, and the NA reached 0.83. The corresponding conversion efficiency of the unit structure reached as high as 94%, and the full width at half maximum was only 117.2 nm. Metalenses with large NA can act as optical tweezers and can be applied to trap ultracold atoms and molecules. Secondly, a focused VB metalens in the wavelength range of 200 nm–300 nm was also designed, which can convert polarized light into a VB and focus the VB simultaneously. Finally, a metalens array was developed to focus VBs with different topological charges on the same focal plane. This series of UV metalenses could be widely used in UV microscopy, photolithography, photonics communication, etc.
Realization of high-efficiency AlGaN deep ultraviolet light-emitting diodes with polarization-induced doping of the p-AlGaN hole injection layer
Authors: Cao Yi-Wei , Lv Quan-Jiang , Yang Tian-Peng , Mi Ting-Ting , Wang Xiao-Wen , Liu Wei , Liu Jun-Lin
Published: October 2022

We investigate the polarization-induced doping in the gradient variation of Al composition in the p-Al0.75Ga0.25N/Al
x
Ga1−x
N hole injection layer (HIL) for deep ultraviolet light-emitting diodes (DUV-LEDs) with an ultra-thin p-GaN (4 nm) ohmic contact layer capable of emitting 277 nm. The experimental results show that the external quantum efficiency (EQE) and wall plug efficiency (WPE) of the structure graded from 0.75 to 0.55 in the HIL reach 5.49% and 5.04%, which are improved significantly by 182% and 209%, respectively, compared with the structure graded from 0.75 to 0.45, exhibiting a tremendous improvement. Both theoretical speculations and simulation results support that the larger the difference between 0.75 and x in the HIL, the higher the hole concentration that should be induced; thus, the DUV-LED has a higher internal quantum efficiency (IQE). Meanwhile, as the value of x decreases, the absorption of the DUV light emitted from the active region by the HIL is enhanced, reducing the light extraction efficiency (LEE). The IQE and LEE together affect the EQE performance of DUV-LEDs. To trade off the contradiction between the enhanced IQE and decreased LEE caused by the decrease in Al composition, the Al composition in the HIL was optimized through theoretical calculations and experiments.
High photon detection efficiency InGaAs/InP single photon avalanche diode at 250 K
Authors: He Tingting , Yang Xiaohong , Tang Yongsheng , Wang Rui , Liu Yijun
Published: October 2022

Planar semiconductor InGaAs/InP single photon avalanche diodes with high responsivity and low dark count rate are preferred single photon detectors in near-infrared communication. However, even with well-designed structures and well-controlled operational conditions, the performance of InGaAs/InP SPADs is limited by the inherent characteristics of avalanche process and the growth quality of InGaAs/InP materials. It is difficult to ensure high detection efficiency while the dark count rate is controlled within a certain range at present. In this paper, we fabricated a device with a thick InGaAs absorption region and an anti-reflection layer. The quantum efficiency of this device reaches 83.2%. We characterized the single-photon performance of the device by a quenching circuit consisting of parallel-balanced InGaAs/InP single photon detectors and single-period sinusoidal pulse gating. The spike pulse caused by the capacitance effect of the device is eliminated by using the characteristics of parallel balanced common mode signal elimination, and the detection of small avalanche pulse amplitude signal is realized. The maximum detection efficiency is 55.4% with a dark count rate of 43.8 kHz and a noise equivalent power of 6.96 × 10−17 W/Hz1/2 at 247 K. Compared with other reported detectors, this SPAD exhibits higher SPDE and lower noise-equivalent power at a higher cooling temperature.
Evaluating photosynthetic activity across Arctic-Boreal land cover types using solar-induced fluorescence
Authors: Cheng Rui , Magney Troy S , Orcutt Erica L , Pierrat Zoe , Köhler Philipp , Bowling David R , Bret-Harte M Syndonia , Euskirchen Eugénie S , Jung Martin , Kobayashi Hideki , Rocha Adrian V , Sonnentag Oliver , Stutz Jochen , Walther Sophia , Zona Donatella , Frankenberg Christian
Published: October 2022

Photosynthesis of terrestrial ecosystems in the Arctic-Boreal region is a critical part of the global carbon cycle. Solar-induced chlorophyll Fluorescence (SIF), a promising proxy for photosynthesis with physiological insight, has been used to track gross primary production (GPP) at regional scales. Recent studies have constructed empirical relationships between SIF and eddy covariance-derived GPP as a first step to predicting global GPP. However, high latitudes pose two specific challenges: (a) Unique plant species and land cover types in the Arctic–Boreal region are not included in the generalized SIF-GPP relationship from lower latitudes, and (b) the complex terrain and sub-pixel land cover further complicate the interpretation of the SIF-GPP relationship. In this study, we focused on the Arctic-Boreal vulnerability experiment (ABoVE) domain and evaluated the empirical relationships between SIF for high latitudes from the TROPOspheric Monitoring Instrument (TROPOMI) and a state-of-the-art machine learning GPP product (FluxCom). For the first time, we report the regression slope, linear correlation coefficient, and the goodness of the fit of SIF-GPP relationships for Arctic-Boreal land cover types with extensive spatial coverage. We found several potential issues specific to the Arctic-Boreal region that should be considered: (a) unrealistically high FluxCom GPP due to the presence of snow and water at the subpixel scale; (b) changing biomass distribution and SIF-GPP relationship along elevational gradients, and (c) limited perspective and misrepresentation of heterogeneous land cover across spatial resolutions. Taken together, our results will help improve the estimation of GPP using SIF in terrestrial biosphere models and cope with model-data uncertainties in the Arctic-Boreal region.
Quantum-jump vs stochastic Schrödinger dynamics for Gaussian states with quadratic Hamiltonians and linear Lindbladians
Authors: Christie Robson , Eastman Jessica , Schubert Roman , Graefe Eva-Maria
Published: October 2022

The dynamics of Gaussian states for open quantum systems described by Lindblad equations can be solved analytically for systems with quadratic Hamiltonians and linear Lindbladians, showing the familiar phenomena of dissipation and decoherence. It is well known that the Lindblad dynamics can be expressed as an ensemble average over stochastic pure-state dynamics, which can be interpreted as individual experimental implementations, where the form of the stochastic dynamics depends on the measurement setup. Here we consider quantum-jump and stochastic Schrödinger dynamics for initially Gaussian states. While both unravellings converge to the same Lindblad dynamics when averaged, the individual dynamics can differ qualitatively. For the stochastic Schrödinger equation, Gaussian states remain Gaussian during the evolution, with stochastic differential equations governing the evolution of the phase-space centre and a deterministic evolution of the covariance matrix. In contrast to this, individual pure-state dynamics arising from the quantum-jump evolution do not remain Gaussian in general. Applying results developed in the non-Hermitian context for Hagedorn wavepackets, we formulate a method to generate quantum-jump trajectories that is described entirely in terms of the evolution of an underlying Gaussian state. To illustrate the behaviours of the different unravellings in comparison to the Lindblad dynamics, we consider two examples in detail, which can be largely treated analytically, a harmonic oscillator subject to position measurement and a damped harmonic oscillator. In both cases, we highlight the differences as well as the similarities of the stochastic Schrödinger and the quantum-jump dynamics.
Effects of Bifidobacterium lactis HN019 and Lactobacillus acidophilus NCFM on volatile sulfur compounds produced by oral anaerobes
Authors: Huang Peiqing , Yuan Shaotang , Xu Xin , Peng Xian
Published: October 2022

Halitosis is a term that refers to an unpleasant or foul odor originating from oral cavity, which is mainly caused by volatile sulfur compounds (VSCs) produced by oral anaerobes such as Porphyromonas gingivalis, Fusobacterium nucleatum, Treponema denticola and Prevotella intermedia. General therapies, such as tooth and tongue brushing or usage of bacteriostat can hardly provide a harmless and continuous therapeutic effect on halitosis. Recent evidence has suggested the potential clinical application value of probiotics in the treatment of halitosis. In this study, Bifidobacterium lactis HN019 and Lactobacillus acidophilus NCFM were identified from four kinds of probiotics and the antimicrobial activities against pathogens related to halitosis and inhibitory effects on VSCs were investigated. The results showed that B. lactis HN019 and L. acidophilus NCFM exhibited superior bacteriostatic action against pathogens related to halitosis and showed remarkable inhibitory effect on the production and emission of VSCs. These findings suggest that B. lactis HN019 and L. acidophilus NCFM may serve as promising parts of a successful halitosis manage plan.
Sungai Subang Rehabilitation Methods towards a Liveable and Integrated Environment Approach
Authors: Malek Nurhayati Abdul , Ani Fairouz Che , Othman Noriah
Published: October 2022

Ensure the availability and sustainable management of water and sanitation for all nations aim to the Sustainable Development Goal 6 (SDG) formed under the 2030 Agenda for Sustainable Development. The current United Nations (UN) report release stated that the UN targets all people to enjoy access to freshwater in its quality and quantity. Hence, achieving the goal is one of the significant challenges to all governments by 2030. In tandem with vast industrial development and an increase in its population, Malaysia is one of the developed countries facing water sufficiency issues regarding its quality and management. This study believes that poor water management, lack of public awareness, vast development, urbanisation, lack of integration, and a holistic approach are the leading causes of water quality depletion in Malaysia. Responding to the issues mentioned above, water sustainability approaches are believed to be one of the solutions to tackle the problems in this study. The data were gathered using qualitative methods of i) Document analysis and ii) Site inventory. It has taken place in Sg. Subang, one of the polluted rivers, and this project applied sustainable water approaches in its design to overcome the existing river issues. Hence, the river becomes part of the open spaces to serve the nearby residence.
Assessment for Local Road Scenic Routes Conservation - Tanjung Karang to Sabak Bernam
Authors: Ismail Junairiza , Misni Alamah
Published: October 2022

Nowadays, many people are interested in using the highway rather than using the local road to go to their destination. The roads have many interesting points that can attract road users to use the road. Still, the road user did not consider the existing natural and cultural landscape as one of the attractions in the area. It can make the loss of the value of the natural and artistic at the location. This study was conducted to identify the scenic view observable along the scenic route and the influence on the road user along the Tanjung Karang to Sabak Bernam road. The study had used the mixed-method, which is qualitative and quantitative. The scenic routes provided access to people to go to the natural and cultural features. Besides that, it also identifies the road that will intrigue the road user according to the uniqueness, naturalness, vividness, attractiveness and unity of the study area.
Understanding local community and the cultural heritage values at a World Heritage City: a grounded theory approach
Authors: Bakri Aidatul Fazlin , Zaman Nurulhusna Qamaruz , Kamarudin Hikmah
Published: October 2022

The nomination of a World Heritage site generally focuses on the tangible heritage assets, and intangible heritage is given less attention in the site management. There is also a lack of awareness of the complicated relationship between tangible and intangible heritage assets, the meanings and values of the site to its local community, and the complexity of space in the World Heritage Site in the management of cultural heritage sites. This paper discusses grounded theory to investigate the relationship between local communities and their cultural heritage in George Town World Heritage Site, Malaysia. The methodology employed an ethnographic approach for the observational work and semi-structured interviews. The findings demonstrate a deep and rich knowledge of the links between the World Heritage designation and its local communities, including how local people interact and contribute meaning to the site. This study may encourage other researchers to apply grounded theory to understand social phenomena on other World Heritage Sites of similar context for heritage management purposes.
A Study on the indoor air quality (IAQ) at primary school in Industrial Area: A case study to Sekolah Kebangsaan Pasir Gudang 3(SKPG3)
Authors: Mohamad Nor Zaki Natasya Kamilia , Ahmad Bari Nor Azmi
Published: October 2022

Existing research has shown that numerous air contaminants are present in classrooms, sometimes in high concentrations, which may have an impact on children’s health and academic performance. In order to create a safe, healthy, productive, and comfortable atmosphere for students, instructors, and other school personnel, schools must have good indoor air quality. This study has assessed the current IAQ’s level at selected school in one of the industrial areas in Johor Bahru, which is Pasir Gudang. To measure the quality of the indoor air parameters, three chemical substances which are Formaldehyde (HCHO), Total Volatile Organic Compound (TVOC) and Particulate Matter (PM) in the classroom were assessed. Besides that, this study also analyzed the temperature and relative humidity of the classroom surrounding. Furthermore, the students’ insight on the impact of IAQ parameters towards their class performances were also explored using questionnaire survey. It was found that physical parameters of the classroom were in good state, but the relative humidity percentage range was too high. Meanwhile, on the chemical contaminants, the measurement shows that the concentration of PM, HCHO and TVOC for the classroom are still in the permissible exposure range. In the end, some suggestions have been made to provide good indoor quality in the classroom by emphasizing proper design, construction, and ongoing maintenance procedures.
Successful Park Characteristics and Users’ Behavior: An Experience of Perdana Botanical Garden, Kuala Lumpur
Authors: Hashim Nur Idzhainee , Mohd Hashim Nor Hanisah , MohdNasir Nurul Akmaniza , Mohd Soliheen Siti Syahirah
Published: October 2022

A successful park characteristic includes four crucial indicators; access and linkages, comfort, and image, users and activities and sociability. Good accessibility and well connected are important factors that urban park should have in order to expand its values and encourage social interaction among visitors. The result of this study proved that urban park characteristics such as adequate accessibility, be able to foster good sociability, offers comfort while being in the park and variety of uses and activities contributes to the successful of an urban park.
Preferred green home features by potential buyers in Sibu Sarawak
Authors: Wong Shi Yee , Wong Sing Sing , Palis Prescilla Anak
Published: October 2022

Green concept was gaining attention since 1960s, with research and development initiatives been allocated to ensure its evolvement, for enhancing the minimization on the impact of global warming and greenhouse gases emissions. Enormous green home features be introduced worldwide, but such features were not collated into a single piece of information, and the preference of home buyers varies according to the culture, living environment, and personal preferences. This research aims to examine the relative importance of green home features to potential home buyers in Sibu, Sarawak. Purposive and random sampling methods were adopted as the participants need to meet the requirement of having intention to purchase a house in Sibu in the next five years. Quantitative online questionnaire survey was distributed to the potential home buyers with 118 valid responses returned (response rate 29.57%). The results indicated that air quality, energy saving lighting, and energy efficient air conditioner were the three most preferred features by the respondents. This research could contribute to the knowledge gap of the preferred green home features by the potential home buyers in Sibu, and hence, serve as a piece of supporting document to the developers, to meet buyers’ demand and further increase the supply of green home in Sibu.
The Commitment of Local Authority Offices toward Sustainable Energy Practices
Authors: Sharkawi Nasrudin , Hasim Mohamad Sufian , Adnan Hamimah , Kamarudin Hikmah , Yaman Rostam
Published: October 2022

Globally, there is a strong trend among local authority offices towards focusing on energy sustainability. This movement is vital as they faced challenges in managing their assets due to financial constraints and declining resources. This study aims to investigate the commitments of the local authority offices in Malaysia towards sustainable energy practices. The objective of this study was to identify the sustainable energy initiatives implemented within the selected local authorities in Malaysia as a case study. For this research context, ‘the commitment’ refers to the extent of information found concerning sustainable energy initiatives undertaken to manage their assets. Eight (8) semi-structured interviews with FM practitioners representing the eight local authorities from the City Hall and Municipal Council categories were conducted. Generally, the commitment of the local authority offices in Malaysia towards sustainable energy implementation was still at an initial stage, with seven (7) related initiatives identified. However, the introduction of energy-saving techniques, energy-saving technology, energy-saving equipment, and encouraging the involvement of officers and staff in energy-saving was the most significant initiatives identified. Therefore, given this perspective, the proactive role of local authorities is needed towards sustainable energy implementation. Indeed, this organisation have to take the lead in achieving sustainability goal.
Challenges of Adopting Building Information Modelling (BIM) Technology amongst SME’s Contractors in Malaysia
Authors: Adillah Ismail Noor Akmal , Aswad Zulkifli Mohd Zul , Azrin Baharuddin Har Einur , Wan Ismail Wan Norizan , Mustapha Arniatul Aiza
Published: October 2022

BIM is a modelling technology consisting digital tools that can be used in project planning, design, monitoring and control, to ensure efficiency in construction project delivery. In Malaysia, the Government has made several initiatives to promote BIM so that it could be used widely by the construction professionals to enhance the construction industry practices. However, the implementation of BIM in Malaysia has faced some challenges especially amongst smaller size construction companies. Although several initiatives were extensively fostered, the reluctance of implementing BIM amongst SME’s contractors still exists. Therefore, the aim of this study is to explore the challenges of BIM adoption amongst SME’s contractors in the Malaysian construction industry. A survey using questionnaire was conducted to identify the challenges and the results were analysed by adopting descriptive analysis and Average Index using IBM SPSS Statistic 23. The findings from the survey revealed the cost issue as one of the major challenges in adopting BIM amongst the SME’s contractors in Malaysia. To invest for BIM technology, high cost is needed for BIM software and hardware installation, proper training of staff to use BIM platform, and specific certification and license requirement. This study is significant in terms of getting input on the current BIM adoption amongst the construction players focusing on the SME’s contractors which could be used as a reference point and benchmark towards BIM development in the Malaysian Construction Industry.
COVID-19 Pandemic: The Impacts and Prospects in the Malaysian Construction Projects
Authors: Bin Mohamed@Arifin Mohd Amizan , Hizami Bin Azmi Muhamad Fahim , Binti Mohd Sheffie Syahirah Intan
Published: October 2022

COVID-19 pandemic has impacted the world globally. To prevent and reduce the virus from spreading, many countries have implemented lockdown, including Malaysia. Restrictions on people movements include social distancing and virtual working. These have impacted the construction industry because it needs real-time inspections at the site and on-site work. The negative impacts on construction projects during lockdowns such as project delay, lack of raw material, shortage of labour, and loss of income would increase the probability of implementations on remote working, Artificial Intelligence, increase in Force Majeure Claims, and requirement of the local worker to face against COVID-19 situation in the new norm. Therefore, this research is essential to be explored to obtain more details about the current construction industry: the impacts of pandemic COVID-19 on construction projects in Malaysia and the prospects of construction projects post COVID-19 as mitigation strategies to survive this pandemic. This pilot study was conducted in Klang Valley (Selangor and Kuala Lumpur). The respondents were directly involved in the projects, i.e., project managers, engineers, and site supervisors. The sample population was registered for construction projects in 2020, obtained from Construction Industry Development Board (CIDB). Collected data from the questionnaire were analysed using Statistical Packages for Social Science (SPSS). Consequentially, the results of this research will benefit Malaysia’s construction industry in justifying the impacts of COVID-19 on construction projects. Hence, offering alternatives to sustain and prepare the construction industry with unexpected circumstances that could happen during this unprecedented pandemic.