bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen technology in Sub-Saharan Africa: Prospects for Power Plants
Authors: Fopah-Lele Armand
Published: July 2022

Hydrogen as an energy vector could be one of the solutions to the crucial energy crisis in sub-Saharan Africa. A technological review is done in this paper as a first attempt to foster research and development on the subject. It shows the hydrogen technology disadvantages and difficulties regarding its usage in Africa, and explores ways to better tackle them. Concepts are also discussed by showing the benefits of hydrogen introduction in sub-Saharan African countries on their economy through the increase of their electrification coverage and the reduction of electricity shortages witnessed in these countries. Ideas of systems hybridization including hydrogen fuel cells are presented, discussed and adapted to the sub-Saharan context. Methods of overcoming possible risks, technologies that could be adopted now and on-going research on the subject are finally performed.
Charge-Controller Optimization on Lead-Acid Battery in Solar PV Systems: Temperature Effects and Efficiency Improvement
Authors: Fai Yenku Clearance , Fendji Marie-Danielle , Fopah-Lele Armand , Tsuanyo David
Published: July 2022

Long-term cell performance is very sensitive to the cell operating temperature, and cell storage capacity can degrade quickly, if the temperature is not maintained within a narrow range (25–50 °C) during charging and discharging of (solar) batteries [1]. Efforts are recently being dedicated to developing models that seek to provide insights into that issue. However, not all models consider the operation of the photovoltaic (PV) battery storage system with regard to battery optimization and temperature effects. The present work provides a controllable algorithm to help charge controllers provide exact amount of PV electricity (charge equalization) to batteries with temperature compensation included, and a proposed charging and discharging schedules of the battery storage. The temperature compensated duty cycle for charging is modelled and the pulse-width modulation (PWM) signal is programmed to change with temperature following this duty cycle model. This research work is based on the optimization of solar battery storage where the micro controller-based charge controller enhances battery life by monitoring the temperature and controlling charging voltages and float charging voltages for specific temperatures. A buck converter was simulated in Proteus, and then realized in the laboratory. The duty cycle of the buck converter was adjusted with temperature. Results collected from lab experiments were plotted on MatLab and it shows homogeneity with calculated results. Moreover, battery-charging currents, battery direct current (DC) disconnect and battery switching for charging and discharging were performed for the converter. Future work is to extend this study to large-scale solar photovoltaic systems in order to overcome the operation limits encountered.
Climate change and some adaptation measures in the Sudano-Sahelian zone of Cameroon
Authors: Djongyang Noël
Published: July 2022

Cameroon aspires to emergence by 2035. Since 2009, it has drawn up reference documents such as the “Vision 2035” and the “Strategy Document for Growth and Employment”, which include growth goals such as poverty reduction, economic development, industrialization, democracy and unity. In addition, in the document of the Intended Determined Contribution to the National Plan submitted to the United Nations, the country undertakes to reduce its greenhouse gas emissions up to 32% by 2035, with particular emphasis on renewable energy which will contribute 25% of total electricity production. The Sudano-Sahelian region of Cameroon is the region most threatened by climate change. For more than a decade, actions have been carried out both under government leadership and private initiatives to reduce the effects of global warming on the socio-economic development of the region. In our work, we will present some of the local action plans experienced both in the laboratory and in the field based on energy, agriculture, environmental techniques, and hydraulics and water control.
Design and implementation of solar powered mini refrigerator using thermoelectric cooler module
Authors: Ndobe Ebong Divine , Aloyem Kaze Claude Vidal , Paiguy Ngouateu Armand
Published: July 2022

Remote areas are known for lack of conventional electrical power supply. But it is a common phenomenon to find health centres in remote areas, where vaccination campaigns are done regularly. Due to small populations, vaccines opened cannot be completely used and some usually get bad. The objective of this project is to design and implement a portable and energy efficient refrigerator for preservation of vaccines in medical centres found in remote areas where electric power supply is absent. The novelty of this work is on the use of planks, which are local materials and cheap for the construction of the frame of the refrigerator. The experimental method is used, that helps to determine the functional operation of the system and the limit to which the system functions. The main component of the refrigerator is the thermoelectric cooler module tec1-12706.The system is tested under various conditions such as simultaneous use of PV module and storage battery as source of electrical energy. The absence of cooling fan on the hot side of tec1-12706.The results show that the temperature of the system reduces from 280 C to 50c within one hour of operation. And the temperature of the hot side of the tec1-12706 module increases drastically within 15 minutes of operation if there is an absence of fan on the hot side. With this the module is easily damaged. From the literature review, the COP is maximum0.6 but the present work raises the COP to 0.7.this is done by reducing the input energy. It is then recommended that the system should not be operated without a fan attached to the hot side of the tec1 module.
Real time photovoltaic power forecasting and modelling using machine learning techniques
Authors: Mwende Rita , Waita Sebastian , Okeng’o Geoffrey
Published: July 2022

Photovoltaic (PV) system installations have increased in recent years partly due to growing energy needs from a rising population. Such PV systems producing electricity contribute in promoting green energy. However, solar energy is highly intermittent and uncontrollable due to its high spatial and temporal variations of atmospheric conditions. With such variability, PV power forecasting is therefore crucial for full integration of solar energy into the grid. In this study, Support Vector Regression (SVR) and Random Forest Regression (RFR) models were built and used to forecast real-time PV power output of a 1.5kW solar PV system installed at the Department of Physics, University of Nairobi in Kenya. SVR model outperforms RFR model with root mean square (RMSE) of 43.16 adjusted R2 of 0.97 and mean absolute error (MAE) of 32.57 on the validation. Dataset compared to RMSE of 86, adjusted R2 of 0.90, MAE of 69 were obtained for RFR model. A real time power forecast application based on the SVR model was successfully built using the Shiny application in R software. This shows that SVR model is more robust than RFR and has capabilities of reducing errors during computations.
Analysis of Hybrid Energy Systems for Telecommunications Equipment: A Case Study in Buea Cameroon
Authors: Majoh Kuetche Christelle Flora , Tsuanyo David , Fopah-Lele Armand
Published: July 2022

The considerable expansion of telecommunications infrastructure in non-electrified areas has led to massive consumption of non-renewable energy sources by diesel generators. The promotion of renewable energy technologies as an alternative to these diesel generators is until now confronted with the problems of Capital Expenditures and system reliability. The hybridization of fossil fuels with renewable energies would make it possible to find a better quality/cost/environment ratio for the supply of off-grid telecommunication base stations (BSs).This paper presents the analyses of eight different hybrid energy systems dedicated for telecommunications equipment with a BS antenna as case study. The techno-economic analysis of hybrid energy system comprises solar, wind and the existing power supply. All the necessary modelling, simulations, and techno-economic evaluations are carried out using the assessment software package HOMER (Hybrid Optimization Model for Electric Renewable). The result shows that adding solar PV to the existing system is the optimal option. For the site studied powered by grid and diesel generator, the hybrid PV-diesel-grid with storage battery system is the best optimal system configuration for the chosen antenna with an initial capital cost of 34,619$, a Net Present Cost (NPC) of 55,588$ and a Cost of Energy (COE) of 0.39$/kWh.
Influence of Sidechain Elongation on Photovoltaic Response of Sidechain-Based Statistical Anthracene-Containing Copolymer
Authors: Boudiba Sameh , Adam Getachew , Ulbricht Christoph , Enengl Sandra , Enengl Christina , Boudiba Louiza , Ayuk Mbi Egbe Daniel
Published: July 2022

A new sidechain-based statistical anthracene-containing poly(arylene-ethynylene)-alt-poly(p-phenylene-vinylene) (P2) bearing 2-ethylhexyloxy and decyloxy side chains was synthesized to study the effect of elongating the sidechain length from octyloxy (as in P1) to decyloxy (as in P2) on the photovoltaic performance. The polymer was prepared using the Horner-Wadsworth-Emmons olefination reaction of two dialdehydes with two bisphosphonate esters. NMR and FTIR spectroscopy characterization were employed to prove the formation of the desired polymeric structure. The photophysical and electrochemical properties showed a broad spectral range of absorption in the visible region and reversible redox activity, respectively. Thermogravimetric analysis (TGA) indicated good thermal stability. Non-optimized bulk-heterojunction solar cells achieved power conversion efficiency (PCE) of 2.4 % for P2. The reduced performance of P2 compared to P1 based solar cells (PCE 3.8%) might originate from inferior nanomorphology of the active layer blend and/or the “dilution” of the photoactive conjugated backbone upon elongation of solubilising sidechains.
Study of ecological charcoal production from agricultural waste
Authors: Djoukouo Nadia H. D. , Djousse Boris M. K. , Djoukeng Henri G. , Egbe Daniel A. M. , Wembe Brillant D. , Kouonang Fabrice C.
Published: July 2022

Wood fuel is undoubtedly the main source of energy for cooking in sub-Saharan Africa as it represents more than three quarter of household energy consumption. The exploitation of wood for fuel purposes contributes to forest degradation. It is becoming urgent to diversify domestic energy sources. Substituting other forms of energy with traditional ones is extremely difficult due to low income of the population and culinary habits. In this context, ecological charcoal seems to be an attractive alternative to wood energy. Agricultural waste was collected, dried to a moisture content of less than 10%. Waste was pyrolysed and the resulting carbonaceous material mixed with a binder and extruded to form briquettes. Three binders were tested: starch, clay and arabic gum. The pyrolysis of biomass generated three by-products: a solid (biochar), liquid and gaseous product. This process took 3 hours 45 minutes to convert 1tonne of waste into 390 kg of biochar and 133 liters of pyrolyser oil. After testing, biochar/binder ratios of 27/1.1, 27/2.7 and 27/2.1 for starch, gum arabic and clay, respectively, at a compaction pressure of 7.8 bar were validated.
Effect of layer type distribution within the crystallite on the diffracted (00ℓ) theoretical intensities
Authors: Mejri Chadha , Oueslati Walid , Ben Haj Amara Abdesslem
Published: July 2022

The XRD-pattern modelling, in the case of layered materials, provides an accurate structural characterization on the layer’s composition and the interlamellar space configuration. The layer type distribution, within the crystallite, is a key parameter and is considered as stacking defects affecting the researched best agreement between theoretical and experimental XRD profiles. This work investigates the effect of layer distribution type (mathematical functions) on the diffracted XRD theoretical intensity to optimize the final adopted model in the case of montmorillonite SWy-Na exchanged Barium. Obtained results showed that several distributions can be approved to carry out the 00ℓ reflection modelling.
Sich im Schulsystem etablieren – Schulbegleitung
Authors: Thierschmidt Anne-Katrin
Published: July 2022

Kindern die Teilhabe am Schulalltag ermöglichen und sie zu Selbstbestimmung zu empowern zählt zu den Aufgaben einer Schulbegleitung. Auch Ergo- therapeut*innen können in diesem Handlungsfeld tätig werden. Es birgt jedoch nicht nur Chancen, sondern auch Herausforderungen und Barrieren, die es zu überwinden gilt.
Synthesis of 7-Arylpurines from Substituted Pyrimidines
Authors: Novosjolova Irina , Turks Māris , Sebris Armands
Published: July 2022

A simple three-step approach for the synthesis of substituted N7-arylpurines with an overall yield of the whole sequence from 40% to 71% is described. N7-Arylpurines were constructed by de novo synthesis from commercially available substituted 4-chloropyrimidine-5-amines. Different substituents at purine C2 and C6 were obtained by changing the corresponding substituents of the starting pyrimidine. Further, heteroaromatic, electron-deficient, and electron-rich aromatic groups were attached to the exocyclic amino group by iodane reagents under copper catalysis. This moiety is prepared to become purine N7 position after the ring closure. Finally, purine C8 substitution was varied during the last step of the developed sequence by employing different reagents for the purine ring closing reactions or post functionalization.
Asymmetric Construction of Highly Functionalized Cyclobutanones Bearing Three Contiguous Stereogenic Centers by an Amino Acid Salt-Catalyzed Desymmetrization Reaction
Authors: Wu Jingjie , Bao Fengda , Ye Xiaoxia , Jiang Jun , Li Juan
Published: July 2022

We report an amino acid salt-catalyzed direct desymmetrization of 3-substituted cyclobutanones through a direct aldol reaction under mild reaction conditions. The developed method provides an array of highly functionalized cyclobutanones bearing three contiguous stereogenic centers in high yields and stereoselectivities with varied functional-group compatibility. Furthermore, the obtained adducts can be smoothly converted into polyfunctional 1,4-butyrolactones with maintained enantioselectivity.
Solid Primary Retroperitoneal Masses in Adults: An Imaging Approach
Authors: Gulati Vaibhav , Swarup M. Sarthak , Kumar Jyoti
Published: July 2022

Mass lesions in the retroperitoneal space may be primary or secondary. Primary retroperitoneal mass lesions are relatively uncommon as compared to pathology that arises secondarily from retroperitoneal organs. These may be solid or cystic lesions. The overlapping imaging features of various solid primary retroperitoneal tumors make the diagnosis difficult, and hence, histopathology remains the mainstay of diagnosis. This paper provides a brief review of the anatomy of the retroperitoneal space and provides an algorithmic approach based on cross-sectional imaging techniques to narrow down the differential diagnosis of solid primary retroperitoneal masses encountered in the adult population.
Bilateral Talocalcaneal and Talocalcaneocentral Luxation after a Road Traffic Accident in a Dog
Authors: Serrano-Crehuet Tomas , Espinel-Rupérez Jorge , Amorós Olga , Mullins Ronan A.
Published: July 2022

A 4-year-old, 25 kg, male, castrated, crossbreed dog was referred after having been driven over by a trailer 3 days prior. On examination, the dog was unable to ambulate on the pelvic limbs. There was crepitus, soft tissue swelling and pain on manipulation of the tarsi, with bilateral rotational and suspected mild lateral instability. Radiographs identified bilateral talocalcaneal luxation with dorsal displacement of the head of talus and bilateral avulsion fracture of lateral malleolus. A dorsomedial approach to the tarsocrural joint was performed bilaterally and the dorsal luxation of the head of talus was reduced. A 3.5 mm positional cortical screw was placed on both sides from dorsomedial head of talus to plantarolateral distal calcaneus. A temporary calcaneotibial screw was also applied bilaterally. No complications were encountered apart from mild bandage-related dermatitis, and the dog made a complete recovery. No lameness was identified on subjective gait assessment at 14 weeks and 12 months postoperatively; however, mild-to-moderate osteoarthritis affecting the talocalcaneocentral and centrodistal joints was identified at 12 months postoperatively.
Colloidal gels age differently under shallow, deep quenches
Authors: Piccone Ashley
Published: July 2022

If a quench is deep enough, complex phenomena can trap a nonequilibrium gel and inhibit its strengthening over time.
Verification of a fully kinetic ion model for electromagnetic simulations of high-frequency waves in toroidal geometry
Authors: Yu Y. Y. , Wei X. S. , Liu P. F. , Lin Z.
Published: July 2022

For the study of high-frequency electromagnetic waves in tokamaks, an electromagnetic simulation model, in which the ion dynamics is described by a six-dimensional Vlasov equation and the electron dynamics is described by a drift kinetic equation, is formulated and implemented in the global gyrokinetic toroidal code (GTC). Analytic dispersion relations are derived in reduced systems and compared with various theories to verify the model. Linear simulations of a generalized ion Bernstein wave and ion cyclotron emission are verified by comparing the GTC simulation results with analytic dispersion relation theory and magnetoacoustic cyclotron instability theory, respectively, in cylindrical geometry.
Plasma-enhanced fluorination of multi-walled carbon nanotubes for CFx cathode materials with ultrahigh electrochemical performance
Authors: Zhou H. P. , Yao L. S. , Chen G. T. , Zhang S. , Feng T. T. , Xu Z. Q. , Wu M. Q.
Published: July 2022

As one of the most promising lithium primary batteries, lithium/fluorinated carbon (Li/CFx) batteries are irreplaceable in military, aerospace, medical, and other markets due to their advantages such as the high energy density, long shelf life, and wide operating temperature. However, it is difficult to enable CFx cathode materials to achieve simultaneously high-capacity and excellent rate-capability. Moreover, the high-temperature direct F2 fluorination method for the commercial CFx material preparation is hazardous, eco-unfriendly, and costly. Herein, we developed an efficient, safe, and cost-effective synthesis approach, in which plasma fluorinated multi-walled carbon nanotubes (PFCNTs) were synthesized by using CF4 plasma as a fluorine source under a low fluorination temperature (300 °C) within excessively short time (110 min). The plasma not only induced ionization of CF4 gas through the electron impact reaction but also promoted the diffusion of fluorine-containing ions in multi-walled carbon nanotubes. The PFCNT possessed un-fluorinated graphitic inner layers, electrochemically active semi-ionic C–F bonds, and few inactive C–F2 and conductive sp2 C=C bonds, endowing it excellent electronic and electrochemical properties. PFCNTs exhibited a high specific capacity of 819.3 mAh/g with an energy density of 2050 Wh/kg. Furthermore, a Li/PFCNT coin cell delivered a capacity of 527.4 mAh/g and a maximum power density of 58 206 W/kg at an ultrahigh current density of 30 A/g. The underling fluorination mechanism was also analyzed by combining with the plasma diagnostic tool of optic emission spectroscopy.
On the equivalence between mass perturbation and DC voltage bias in coupled MEMS resonators: Theoretical and experimental investigation
Authors: Rabenimanana Toky , Najar Fehmi , Ghommem Mehdi , Walter Vincent , Kacem Najib
Published: July 2022

In this work, we consider MEMS devices made of mechanically coupled microbeams under electric actuation. We conduct an experimental study to identify the occurrence of veering and then investigate its dynamic response for different electric actuations. A slight change in the DC voltage bias from the veering point is observed to affect significantly the frequency response. Indeed, jump to large orbits occurred when perturbing the applied DC voltage while operating near the cyclic-fold bifurcation point. We also develop and validate a mathematical model to simulate the response of the device. The model showed similarities in the softening effect of the DC voltage bias and an added mass when matching their induced shift in the natural frequency. As such, one can discern the inherent nonlinear effects of DC voltage bias on coupled resonators and exploit them for mass sensing applications without going over the hassle of mass deposition, which requires the deployment of complex processes. We also investigate different mass detection mechanisms. We show the potential of mode localization and the significant and abrupt jumps in the deflection of the coupled microbeams due to mass perturbation to enhance the sensitivity of MEMS mass sensors.
Thermocapillary-driven dynamics of a free surface in microgravity: Control of sloshing
Authors: Gligor D. , Salgado Sánchez P. , Porter J. , Ezquerro Navarro J. M.
Published: July 2022

Numerical simulations are used to analyze the dynamics of a free surface excited by thermal modulations at the lateral boundaries that generate a time-dependent thermocapillary flow. Fluid parameters are selected to be representative of 5 cSt silicone oil. Following the work of Gligor et al. [“Thermocapillary-driven dynamics of a free surface in microgravity: Response to steady and oscillatory thermal excitation,” Phys. Fluids 34, 042116 (2022)], the response of the free surface to oscillatory thermal excitation is characterized by the displacement of the contact points, and a frequency sweep is used to obtain a Bode-type diagram that reveals a resonance peak in the vicinity of the first sloshing mode. The ability of the thermocapillary flow to excite this sloshing mode suggests a control strategy that uses thermal modulations to dampen sloshing motion. After the response of the isothermal surface to a generic pulse-like inertial perturbation is measured, a classical proportional integral derivative control is implemented and the effect of its gains is considered separately. The efficacy of the controller is characterized by the decay time of the contact point oscillations and by a cost function. The effect of possible delays in the control loop is accounted for. Finally, a controller with a derivative gain is selected and used to dampen the motion induced by a reboosting maneuver of the International Space Station.
On the interfacial dynamics and capillary waves during impingement of a drop on liquid pool: A background-oriented schlieren study at low Weber numbers
Authors: Shahdhaar Mohammad Autif , Srivastava Atul , Singh Suneet
Published: July 2022

Understanding the dynamics of a droplet impinging on a liquid pool and the associated phenomena have been of interest due to its prevalence in nature as well as in technical applications. This paper aims toward studying the characteristics of the capillary waves generated due to the low Weber number droplet interactions with the liquid pool. In this direction, experiments have been carried out for six different pool heights varying from h = 1.4 to 12 mm, encompassing thin liquid film, shallow pool, and deep pool regimes. Due to its wide usage, water has been chosen as the fluid of interest for droplet as well as for pool liquid. The study is focused on droplets impinging on the liquid pool at low Weber number ranging from 1 to 100. In order to characterize the post-impact perturbations in the liquid, background oriented schlieren (BOS) technique has been employed which offers real-time, non-intrusive whole-field measurements of the perturbations in the liquid pool. Measurements from BOS have been validated against the side-view projection of the impact. The transient variations of the air–water interface for different pool regimes and Weber numbers have been delineated. Results evince the formation of secondary wave at impact followed by the formation of primary wave after the crater retraction. The wave formation was faster and had higher amplitude in thin liquid regime for droplets with the same Weber number compared to the other regimes, but the perturbations were reduced through higher dissipation. The formation of the Worthington jet was seen in shallow and deep pool regimes for droplets with higher Weber number (We = 100), and its effect on the capillary wave is also discussed.
Model predictive control-based energy management strategy with vehicle speed prediction for hybrid electric vehicles
Authors: Xu Enyong , Wei Fumin , Lin Changbo , Meng Yanmei , Zhu Jihong , Liu Xin
Published: July 2022

The speed of a hybrid electric vehicle is a critical factor that affects its energy management performance. In this study, we focus on the importance of solving the problem of inaccurate speed prediction in the energy management strategy (EMS) and application of dynamic programming (DP) needs to know the entire driving cycle. A gated recurrent unit neural network (GRU-NN) speed predictive model based on machine learning is developed by using the model predictive control (MPC) framework and solved in the prediction domain by employing DP. The neural network is trained on the training set, which is a collection of standard driving cycles. The results are compared with other two types of speed predictive models to verify the effects of different parameters of different speed predictive models on the state of charge and fuel consumption under Urban Dynamometer Driving Schedule driving cycle. Simulation shows that MPC based on the GRU-NN speed predictive model can effectively improve the fuel economy of hybrid electric vehicles, with a 94.14% fuel economy, which proves its application potential. Finally, the GRU-NN speed predictive model is applied under the Real-World Driving Cycle, whose fuel consumption has a fuel economy of 91.95% compared with that of the original rule-based EMS.
Low-cost and facile synthesis of LAGP solid state electrolyte via a co-precipitation method
Authors: Ji Fengjun , Xiao Shenyi , Cheng Jun , Li Deping , Liao Jialin , Guo Yixuan , Zhang Hongqiang , Zhang Shuai , Wei Youri , Liu Yunzhuo , Ci Naixuan , Gao Quan , Wang Jiajun , Ci Lijie
Published: July 2022

A solid-state electrolyte with high ionic conductivity and improved safety is a strong competitor in the race for the development of next-generation solid-state lithium batteries, which have stepped into the limelight of materials research. Li1.5Al0.5Ge1.5(PO4)3 (LAGP) with satisfied ionic conductivity (∼10−4 S cm−1) at room temperature, high stability in the ambient atmosphere, and a facile sintering nature shows a promising potential for applications in solid-state lithium batteries. However, the current synthesis methods like solid-state strategy and liquid phase route all require harsh conditions, such as long thermal treatments, expensive raw materials, and complex operation. In this study, we propose a co-precipitation method for synthesizing the LAGP solid electrolyte with low-cost and nontoxic GeO2 as the germanium source. Process optimization in the pH value and water bath temperature was employed as a strategy to eliminate the remnants of GeO2, and the pure LAGP phase is acquired. Moreover, the co-precipitation method can also reduce the sintering temperature of LAGP to 750 °C so that uniform nano-LAGP grains (∼150 nm) can be obtained. During the subsequent processing, denser LAGP pellets are fabricated and exhibit a high ionic conductivity of 5.87 × 10−4 S cm−1 at 30 °C; the Li/Li symmetrical batteries periodically cycle at room temperature for above 310 h with a constant current density of 0.05 mA cm−2.
Sampling constrained stochastic trajectories using Brownian bridges
Authors: Koehl Patrice , Orland Henri
Published: July 2022

We present a new method to sample conditioned trajectories of a system evolving under Langevin dynamics based on Brownian bridges. The trajectories are conditioned to end at a certain point (or in a certain region) in space. The bridge equations can be recast exactly in the form of a non-linear stochastic integro-differential equation. This equation can be very well approximated when the trajectories are closely bundled together in space, i.e., at low temperature, or for transition paths. The approximate equation can be solved iteratively using a fixed point method. We discuss how to choose the initial trajectories and show some examples of the performance of this method on some simple problems. This method allows us to generate conditioned trajectories with a high accuracy.
Reflections on applied cognitive corpus linguistics
Authors: Gilquin Gaëtanelle
Published: July 2022

This article is a response to the commentaries written in reaction to my target article “Cognitive corpus linguistics and pedagogy: From rationale to applications”. It focuses on some issues raised by several commentators: the complexity of applying cognitive corpus linguistics in the language classroom; the question of authenticity in pedagogy; the link between input, intake and output; the place of the teacher and the researcher in applied cognitive corpus linguistics; and possible expansions of the paradigm. It concludes by underlining the importance of exchanges such as those found in this target issue.
JIP3 interacts with dynein and kinesin-1 to regulate bidirectional organelle transport
Authors: Celestino Ricardo , Gama José B. , Castro-Rodrigues Artur F. , Barbosa Daniel J. , Rocha Helder , d’Amico Ennio A. , Musacchio Andrea , Carvalho Ana Xavier , Morais-Cabral João H. , Gassmann Reto
Published: July 2022

The MAP kinase and motor scaffold JIP3 prevents excess lysosome accumulation in axons of vertebrates and invertebrates. How JIP3’s interaction with dynein and kinesin-1 contributes to organelle clearance is unclear. We show that human dynein light intermediate chain (DLIC) binds the N-terminal RH1 domain of JIP3, its paralog JIP4, and the lysosomal adaptor RILP. A point mutation in RH1 abrogates DLIC binding without perturbing the interaction between JIP3’s RH1 domain and kinesin heavy chain. Characterization of this separation-of-function mutation in Caenorhabditis elegans shows that JIP3–bound dynein is required for organelle clearance in the anterior process of touch receptor neurons. Unlike JIP3 null mutants, JIP3 that cannot bind DLIC causes prominent accumulation of endo-lysosomal organelles at the neurite tip, which is rescued by a disease-associated point mutation in JIP3’s leucine zipper that abrogates kinesin light chain binding. These results highlight that RH1 domains are interaction hubs for cytoskeletal motors and suggest that JIP3–bound dynein and kinesin-1 participate in bidirectional organelle transport.
Lensing of gravitational waves: universal signatures in the beating pattern
Authors: Bulashenko Oleg , Ubach Helena
Published: July 2022

When gravitational waves propagate near massive objects, their paths curve resulting in gravitational lensing, which is expected to be a promising new instrument in astrophysics.
If the time delay between different paths is comparable with the wave period, lensing may induce beating patterns in the waveform, and it is very close to caustics that these effects are likely to be observable.
Near the caustic, however, the short-wave asymptotics associated with the geometrical optics approximation breaks down. In order to describe properly the crossover from wave optics to geometrical optics regimes, along with the Fresnel number, which is the ratio between the Schwarzschild diameter of the lens and the wavelength, one has to include another parameter — namely, the angular position of the source with respect to the caustic.
By considering the point mass lens model, we show that in the two-dimensional parameter space, the nodal and antinodal lines for the transmission factor closely follow hyperbolas in a wide range of values near the caustic.
This allows us to suggest a simple formula for the onset of geometrical-optics oscillations which relates the Fresnel number with the angular position of the source in units of the Einstein angle.
We find that the mass of the lens can be inferred from the analysis of the interference fringes of a specific lensed waveform.
An efficient approach to solving fractional Van der Pol–Duffing jerk oscillator
Authors: El-Dib Yusry O
Published: July 2022

The motive behind the current work is to perform the solution of the Van der Pol–Duffing jerk oscillator, involving fractional-order by the simplest method. An effective procedure has been introduced for executing the fractional-order by utilizing a new method without the perturbative approach. The approach depends on converting the fractional nonlinear oscillator to a linear oscillator with an integer order. A detailed solving process is given for the obtained oscillator with the traditional system.
A theoretical investigation of glide dislocations in BN/AlN heterojunctions
Authors: Zhang Shujun
Published: July 2022

Glide dislocations with periodic pentagon-heptagon pairs are investigated within the theory of one-dimensional misfit dislocations in the framework of an improved Peierls–Nabarro (P–N) equation in which the lattice discreteness is fully considered. We find an approximate solution to handle misfit dislocations, where the second-order derivative appears in the improved P–N equation. This result is practical for periodic glide dislocations with narrow width, and those in the BN/AlN heterojunction are studied. The structure of the misfit dislocations and adhesion work are obtained explicitly and verified by first-principles calculations. Compared with shuffle dislocations, the compression force in the tangential direction of glide dislocations has a greater impact on the normal direction, and the contributions of the normal displacement to the interfacial energy cannot simply be ignored.
Pattern transition and regulation in a subthalamopallidal network under electromagnetic effect
Authors: Cao Zilu , Du Lin , Zhang Honghui , Zhao Yuzhi , Shen Zhuan , Deng Zichen
Published: July 2022

Although the significant roles of magnetic induction and electromagnetic radiation in the neural system have been widely studied, their influence on Parkinson’s disease (PD) has yet to be well explored. By virtue of the magnetic flux variable, this paper studies the transition of firing patterns induced by magnetic induction and the regulation effect of external magnetic radiation on the firing activities of the subthalamopallidal network in basal ganglia. We find: (i) The network reproduces five typical waveforms corresponding to the severity of symptoms: weak cluster, episodic, continuous cluster, episodic, and continuous wave. (ii) Magnetic induction is a double-edged sword for the treatment of PD. Although the increase of magnetic coefficient may lead the physiological firing activity to transfer to pathological firing activity, it also can regulate the pathological intensity firing activity with excessive β-band power transferring to the physiological firing pattern with weak β-band power. (iii) External magnetic radiation could inhibit continuous tremulous firing and β-band power of subthalamic nucleus (STN), which means the severity of symptoms weakened. Especially, the bi-parameter plane of the regulation region shows that a short pulse period of magnetic radiation and a medium level of pulse percentage can well regulate pathological oscillation. This work helps to understand the firing activity of the subthalamopallidal network under electromagnetic effect. It may also provide insights into the mechanisms behind the electromagnetic therapy of PD-related firing activity.
Theoretical investigation on the fluorescent sensing mechanism for recognizing formaldehyde: TDDFT calculation and excited-state nonadiabatic dynamics
Authors: Yang Yunfan , Yang Lujia , Ma Fengcai , Li Yongqing , Qiu Yue
Published: July 2022

Inspired by the activity-based sensing method, the hydrazine-modified naphthalene derivative (Naph1) was synthesized and used as a fluorescent probe to detect formaldehyde (FA) in living cells. Through the condensation reaction between the probe Naph1 and analyte FA, researchers observed a ∼14 folds enhancement of fluorescent signal around 510 nm in an experiment, realizing the high selectivity and sensitivity detection of FA. However, a theoretical understanding of the sensing mechanism was not provided in the experimental work. Given this, the light-up fluorescent detecting mechanism was in-depth unveiled by performing the time-dependent density functional theory (TDDFT) and the complete active space self-consistent field (CASSCF) theoretical calculations on excited-state intramolecular proton transfer (ESIPT) and non-adiabatic excited-state dynamics simulation. The deactivation channel of S1/T2 intersystem crossing (ISC) was turned off to successfully recognize FA. Insight into the ESIPT-based fluorescent detecting mechanism indicated that ESIPT was essential to light-up fluorescent probes. This work would provide a new viewpoint to develop ESIPT-based fluorescent probes for detecting reactive carbon species in vivo or vitio.
Boosting the performance of crossed ZnO microwire UV photodetector by mechanical contact homo-interface barrier
Authors: Liu Yinzhe , Liu Kewei , Yang Jialin , Cheng Zhen , Han Dongyang , Ai Qiu , Chen Xing , Zhu Yongxue , Li Binghui , Liu Lei , Shen Dezhen
Published: July 2022

One-dimensional (1D) micro/nanowires of wide band gap semiconductors have become one of the most promising blocks of high-performance photodetectors. However, in the axial direction of micro/nanowires, the carriers can transport freely driven by an external electric field, which usually produces large dark current and low detectivity. Here, an UV photodetector built from three cross-intersecting ZnO microwires with double homo-interfaces is demonstrated by the chemical vapor deposition and physical transfer techniques. Compared with the reference device without interface, the dark current of this ZnO double-interface photodetector is significantly reduced by nearly 5 orders of magnitude, while the responsivity decreases slightly, thereby greatly improving the normalized photocurrent-to-dark current ratio. In addition, ZnO double-interface photodetector exhibits a much faster response speed (∼ 0.65 s) than the no-interface device (∼ 95 s). The improved performance is attributed to the potential barriers at the microwire–microwire homo-interfaces, which can regulate the carrier transport. Our findings in this work provide a promising approach for the design and development of high-performance photodetectors.
Design of readout circuit for high sampling miniaturized MEMS wall shear force sensor
Authors: Guo ZhiJiang , Guo Hui Hui , Liu tingting , Gao Yang
Published: July 2022

Wall shear stress is one of the important measurement parameters in wind tunnel experiments. In the shock wind tunnel, the duration of the flow field is very short, usually a few milliseconds. To ensure measurement accuracy, the sampling rate should not be less than 1kHz. Due to the limitation of model volume and experimental environment, it is necessary to design a miniaturized readout circuit with high precision and high sampling rate, which is highly integrated with the MEMS wall shear stress sensor. The circuit includes a micro capacitance detection module integrated with the sensor head and a host computer signal processing and display module. Aiming at the complex measurement environment of the shock tunnel, to ensure the measurement accuracy, stability, and anti-interference ability of the weak capacitance detection circuit, a miniaturized ceramic substrate circuit is fabricated by a microstrip circuit process. The test results show that the resolution of the micro capacitance of the circuit can reach 20fF at the detection frequency of 3kHz, which can meet the measurement requirements of Shock tunnel, and realize the real-time measurement and display of wall shear stress signal.
An air target association algorithm for infrared sensors
Authors: liu Qing-sheng
Published: July 2022

In order to solve the problem that it is difficult to judge whether the air targets detected by infrared detectors at different locations are the same target, an infrared air target fusion algorithm is proposed. The algorithm constructs a cylindrical coordinate system, introduces two infrared sensors into the cylindrical coordinate system. Then introduces the aerial target information which including azimuth elevation into the cylindrical coordinate system, thus establishing the association between the targets. Finally, the correctness of the algorithm is verified by three rounds of experiments. The simulation results show that the error of the algorithm is within the reservation threshold and has certain engineering application value.
Responses of compound daytime and nighttime warm-dry and warm-humid events to individual anthropogenic forcings
Authors: Chiang Felicia , Cook Benjamin I , McDermid Sonali , Marvel Kate , Schmidt Gavin A , Nazarenko Larissa S , Kelley Maxwell
Published: July 2022

Daytime heat is often associated with reduced soil moisture and cloud cover, while nighttime heat is connected to high humidity and increased cloud cover. Due to these differing mechanisms, compound daytime and nighttime heat events may respond differently to major anthropogenic forcings (greenhouse gases, anthropogenic aerosols, land-use and land-cover change). Here, we use GISS ModelE2.1-G historical single-forcing runs from 1955 to 2014 to examine how individual anthropogenic forcings affect compound heat events—specifically warm daytime and nighttime temperatures compounded with dry precipitation or high humidity conditions. We show that greenhouse gases alone amplify the natural frequency of warm-dry events by 1.5–5 times and warm-humid events by 2–9 times in tropical and extratropical latitudes. Conversely, aerosols and land-use/land-cover change reduce the frequency of these events, resulting in more modest increases and in some regions, declines, in the historical ‘all-forcings’ scenario. Individually, aerosol effects are stronger and more widespread compared to land-use, oftentimes reducing the natural frequency of these events by 60%–100%. The responses of these compound events are primarily driven by changes in daytime and nighttime temperatures through large-scale warming via greenhouse gases and cooling from aerosols and land-use/land-cover change. However, changes in warm-dry events are amplified in regions with concurrent precipitation declines (e.g. Central America, Mediterranean regions) and warm-humid events are amplified by global concurrent humidity increases. Additionally, we find differences between daytime and nighttime compound responses in the historical experiment that can be traced back to the individual forcings. In particular, aerosols produce a greater cooling effect on daytime relative to nighttime temperatures, which notably results in a historical reduction of Northern Hemisphere daytime warm-dry events relative to natural conditions. Our analysis provides a more comprehensive understanding of the significant impacts of different anthropogenic climate forcings on daytime and nighttime warm-dry and warm-humid events, informing future risk and impact assessments.
Wildfire burn severity and emissions inventory: an example implementation over California
Authors: Xu Qingqing , Westerling Anthony LeRoy , Notohamiprodjo Andrew , Wiedinmyer Christine , Picotte Joshua J , Parks Sean A , Hurteau Matthew D , Marlier Miriam E , Kolden Crystal A , Sam Jonathan A , Baldwin W Jonathan , Ade Christiana
Published: July 2022

Wildfire severity is a key indicator of both direct ecosystem impacts and indirect emissions impacts that affect air quality, climate, and public health far beyond the spatial footprint of the flames. Comprehensive, accurate inventories of severity and emissions are essential for assessing these impacts and setting appropriate fire management and health care preparedness strategies, as is the ability to project emissions for future wildfires. The frequency of large wildfires and the magnitude of their impacts have increased in recent decades, fueling concerns about decreased air quality. To improve the availability of accurate fire severity and emissions estimates, we developed the wildfire burn severity and emissions inventory (WBSE). WBSE is a retrospective spatial burn severity and emissions inventory at 30 m resolution for event-based assessment and 500 m resolution for daily emissions calculation. We applied the WBSE framework to calculate burn severity and emissions for historically observed large wildfires (>404 hectares (ha)) that burned during 1984–2020 in the state of California, U.S., a substantially more extended period than existing inventories. We assigned the day of burning and daily emissions for each fire during 2002–2020. The framework described here can also be applied to estimate severity for smaller wildfires and can also be used to estimate emissions for fires simulated in California for future climate and land-use scenarios. The WBSE framework implemented in R and Google Earth Engine can provide quick estimates once a desired fire perimeter is available. The framework developed here could also easily be applied to other regions with user-modified vegetation, fuel data, and emission factors.
No general relation between phase vortices and orbital angular momentum
Authors: Berry M V , Liu Wei
Published: July 2022

Simple superpositions of Laguerre–Gauss beams illustrate, counterintuitively, the difference between two quantities that are commonly conflated: the component of orbital angular momentum ⟨l⟩ in the propagation direction z, and the total topological charge S, which is the algebraic sum of the charges of vortices piercing any plane perpendicular to z. The examples illustrate two contrasting situations: ⟨l⟩ = 0, S ≠ 0, and ⟨l⟩ ≠ 0, S = 0. In the second situation, not only is the total charge zero but also there are no vortices in the infinite half-space beyond the beam waist plane z = 0.
A novel atmospheric pressure hydrolysis without stirring and combustion–calcination process for the fabrication of magnetic Fe3O4/α-Fe2O3 heterostructure nanorods
Authors: Qin Jiang , Liu Min , Wang Zhou , Pei Lin , Zhao Mingjie , Zhou Qunmei , Bin Wu  , Liu Ruijiang
Published: July 2022

Atmospheric pressure hydrolysis without stirring and a combustion–calcination method were utilized to fabricate magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods. First, the β-FeOOH nanorods were fabricated via hydrolysis, and the concentration of Fe3+, hydrolysis temperature, and hydrolysis time were optimized. The optimal fabrication conditions were as follows: a 0.1 M FeCl3 solution was hydrolyzed at 90 °C for 2 h. The average length and diameter of the β-FeOOH nanorods fabricated under the optimal conditions were approximately 216 and 58 nm, respectively. Subsequently, Fe3O4/α-Fe2O3 heterogeneous nanorods were fabricated via a combustion–calcination process. The volume of absolute ethanol, calcination temperature, and calcination time were investigated to optimize the fabrication conditions of Fe3O4/α-Fe2O3 heterogeneous nanorods under the following conditions: absolute ethanol: 50 ml; calcination temperature: 300 °C; and calcination time: 2 h. Magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods fabricated under optimal conditions were characterized with an average length of 199 nm, an average diameter of 51 nm, a zeta potential of +17.2 mV, and a saturation magnetization of 13 emu·g–1.