Miracle-dz/UniFAR-FTUs huggingface dataset:
MHD flow of viscoelastic nanofluid over a stretching sheet in a porous medium with heat source and chemical reaction

The present study investigates the heat and mass transfer of MHD viscoelastic (Walters’ B’ model) nanofluid flow over a stretching sheet embedded in a saturated porous medium subject to thermal slip and temperature jump. A simulation model is established through the analysis on relevant constraints such as stretching of bounding surface keeping the origin fixed and thermal slip and temperature jump on the boundary. The numerical solutions are obtained by Runge-Kutta fourth order method with shooting technique. The affects of important thermo-physical parameters on the velocity, temperature, concentration and surface criteria are displayed and analyzed through graphs and tables. As a result of the analysis, the following observations are made. Elasticity of the base fluid in the presence of nanoparticle acts adversely to the growth of velocity as well as thermal boundary layers. Brownian diffusion, thermophoresis and heat source enhance the fluid temperature resulting the cooling of the stretching surface. Further, positive values of heat and mass fluxes for different values of elastic, magnetic and permeability parameters indicate that heat and mass transfer occur from the stretching surface to the fluid. These recommendations are useful to limit the parameters to design viable heat exchangers. RÉSUMÉ. La présente étude examine le transfert de chaleur et de masse du flux de nanofluide viscoélastique MHD (modèle de Walters) sur une feuille d’étirement encastrée dans un milieu poreux saturé soumis au glissement thermique et au saut de température. Un modèle de simulation est établi par l’analyse de contraintes pertinentes, telles que l’étirement de la surface de délimitation en maintenant l’origine, le glissement thermique et le saut de température sur la limite.Les solutions numériques sont obtenues par la méthode de l’ordre quatre de Runge-Kutta avec technique d’injection. Les effets d'importants paramètres thermophysiques sur les critères de vitesse, de température, de concentration et de surface sont présentés et analysés au moyen de graphiques et de tableaux. À la suite de l'analyse, les observations suivantes sont faites.L'élasticité du fluide de base en présence de nanoparticules agit négativement sur la croissance de la vitesse ainsi que sur les couches limites thermiques. 8 ACSM. Volume 42 – n° 1/2018 La diffusion brownienne, la thermophorèse et la source de chaleur augmentent la température du fluide, ce qui entraîne le refroidissement de la surface d’étirement. En outre, des valeurs positives des flux de chaleur et de masse pour différentes valeurs de paramètres élastiques, magnétiques et de perméabilité indiquent que des transferts de chaleur et de masse ont lieu de la surface d’étirement au fluide.Ces recommandations sont utiles pour limiter les paramètres permettant de concevoir des échangeurs de chaleur viables.
Dynamic modeling and optimized trajectory tracking control of an autonomous tracked vehicle via backstepping and sliding mode control

This article presents a complete kinematic and dynamic modeling and trajectory tracking control of an autonomous tracked vehicle. First, based on the vehicle’s kinematics, the reference linear and angular velocities are evaluated. The kinematic controller is proposed as an integrated backstepping controller. Then, based on vehicle dynamics and slipping characteristics, an integral sliding mode control is utilized to get the desired vehicle drive torques and converge its trajectory to the desired one. Whereas the controller gains are optimally calculated. Furthermore, based on the Lyapunov stability, the proof of stability for proposed controllers is presented. Finally, simulation results are conducted to validate the effectiveness of the proposed control algorithm compared with a hybrid backstepping-modified proportional–integral–derivative dynamic controller and a nonlinear feedback acceleration controller.
An in vitro investigation of Mycobacterium Tuberculosis biofilm formation and its effect on the host innate immune response

Mycobacterium tuberculosis is ostensibly an intracellular pathogen, which may form pellicle-like biofilms in the peripheries of tuberculosis cavities. Environment-induced cell wall modifications and extracellular polymeric substance production may alter host-pathogen interactions. Specifically, expectorated mycobacteria from cavities, which establish infection in new hosts, may have distinct phenotypic adaptations to impair early clearance by the innate immune system. M. tuberculosis H37Rv biofilm extracellular polymeric substance was identified using scanning electron microscopy. Biofilm phenotype non-covalently-bound extracts of cell wall lipids and carbohydrates were compared to planktonic phenotype and a relative reduction in the proportion of constituent glucose in biofilm carbohydrate extracts was discovered, indicative of a reduction in α-glucan prevalence. Comparison of carbohydrate extracts’ potency in stimulating cytokine and chemokine secretion in whole blood and complement activation elucidated reduced C3b/iC3b deposition onto biofilm carbohydrate extracts. Labelling live dispersed M. tuberculosis planktonic and biofilm samples with fluorescent antibodies showed C3b/iC3b, C5b-9, MBL and C1q deposition was reduced on biofilm phenotype cells, using flow cytometry. The relative contribution of each major pathway of complement activation was investigated and greater dependence on classical pathway activation by M. tuberculosis biofilm cells compared to planktonic cells was observed. Implications of these findings in M. tuberculosis pathogenesis are discussed.
Rethinking Current Controller Design for PLL-Synchronized VSCs in Weak Grids

This article revisits the design of the current controller for grid-connected voltage-source converters (VSCs), considering the dynamic impacts of the phase-locked loop (PLL), weak grids, and of voltage feedforward (VFF) control. First, a single-input single-output transfer-function-based model is proposed to characterize the interactions of control loops. It is analytically found that the proportional gain of the current controller essentially aggravates the instability effect of PLL in weak grids, while the cutoff frequency of the low-pass filter used with the VFF loop has a nonmonotonic relationship with the PLL-induced instability. Then, based on these findings, a guideline for redesigning the current controller of PLL-synchronized VSCs is developed, which enables a codesign of the current controller and VFF controller. Finally, simulation and experimental results confirm the validity of theoretical analyses.
Ultrasonically enhanced low-temperature microwave-assisted vacuum frying of edamame: Effects on dehydration kinetics and improved quality attributes

Abstract Using ultrasound (US) at microwave-assisted vacuum Frying (MVF) program was investigated to acquire better process efficacy and bodily high-quality attributes of fried edamame. Different power degrees of US (0, 150, 300, 600 W) and temperature (80, 90, and 100 °C) were utilized in a constant microwave power and frequency of 1000 W and 28 kHz during ultrasound and microwave-assisted vacuum frying (USMVF) process. Ten different mathematical models were employed to describe dehydration kinetics of the fried edamame, and nonlinear regression analysis was used to determine model parameters. Concerning fitting performance, the most suitable model was the two-term model. Drying kinetics, effective moisture diffusivity (De), activation energy (Ea), and physical properties of fried samples were evaluated in this newly designed USMVF equipment using different ultrasound power to the studied temperature range. By increasing the US power level, the calculated De increased from 1.947 × 10−9 to 4.742 × 10−9 m2/s. The results have revealed that the Ea of this fried edamame decreased significantly with increasing the US power level. The USMVF process at every frying temperature increased the drying kinetics and De when compared to the non-USMVF process. The USMVF samples always gave lower oil content and water activity in contrast to the non-USMVF samples. The color and texture properties of fried edamame were significantly improved and higher the US power level in the USMVF produced a better progress. Vitamin C and chlorophyll retention of fried edamame was highest in US600MVF process.
Wound-Healing Activity of Some Species of Euphorbia L.

Some species of Euphorbia have been used as medicinal plants to treat wounds, and skin diseases, around the world. The solvents n-hexane, ethyl acetate, and methanol were used successively to prepare extracts of the aerial parts of E. characias subsp. wulfenii, E. helioscopia, E. macroclada, E. seguieriana subsp. seguieriana, and E. virgata. Linear incision, circular excision wound models and the hydroxyproline assay method were used to assess the wound-healing activity. The inhibition of the increase in capillary permeability induced by acetic acid was used to assay the anti-inflammatory activity. The methanol extract of the aerial parts of E. characias subsp. wulfenii showed statistically significant wound-healing activity with 43.03% tensile strength for the linear incision wound model and a 65.24% reduction in the area of the wound by day 10 for the circular excision model. The tissue treated with this extract was found to contain 35.47 μg/mg of hydroxyproline. The methanol extract of E. characias subsp. wulfenii inhibited inflammation induced by acetic acid with a value of 34.74%. The results showed that the aerial parts of E. characias subsp. wulfenii possess wound-healing and anti-inflammatory activities on different models.
Free radical scavenging activity of two edible vegetables from the Niger delta region of Nigeria

Oxidative stress and diseases that have their aetiology and pathophysiology in reactive oxygen species can be prevented by medicinal plants and herbs. We undertook in this study, to investigate the free radical scavenging activity of dichloromethane (DCM) and ethanol (ETOH) extracts of Lasianthera africana and Gongronema latifolium in vitro using 2, 2, diphenyl-1-picrylhydrazine (DPPH). The leaves of both plants were obtained locally, washed, dried and pulverized using mechanical grinder. The powdered materials were defatted using n-hexane and subsequently extracted with DCM and thereafter with ETOH. The DPPH scavenging potentials of the extracts were then evaluated. The percentage inhibition of the DCM and ETOH extracts were; 46.2 and 80% respectively for L. africana and 37.2 and 82.6 respectively for G. latifolium. The standard substance (quercetin) produced 98.4 per cent inhibition at 1 mg/mL. The IC50 for the L. africana were; 2.017 and 3.256 mg/mL; DCM and ETOH extracts respectively. While that of G. latifolium were 1.495 and 1.116 mg/mL respectively for DCM and ETOH extracts. The standard substance produced IC50 of 0.55 mg/mL. The DPPH inhibitory activity was found to be prominent with the ETOH extracts of both plants. The result from this study validates the use of the leaves of both plants as supplements to improve health conditions and quality of life in general.
Light in Electrochemistry

Electrochemistry represents an important analytical technique used to acquire and assess chemical information in detail, which can aid fundamental investigations in various fields, such as biological studies. For example, electrochemistry can be used as simple and cost-effective means for bio-marker tracing in applications, such as health monitoring and food security screening. In combination with light, powerful spatially-resolved applications in both the investigation and manipulation of biochemical reactions begin to unfold. In this article, we focus primarily on light-addressable electrochemistry based on semiconductor materials and light-readable electrochemistry enabled by electrochemiluminescence (ECL). In addition, the emergence of multiplexed and imaging applications will also be introduced.
Research on correlation of compositions with oestrogenic activity of Cistanche based on LC/Q-TOF-MS/MS technology

Abstract LC technology is a recognized method used worldwide to evaluate the quality of traditional Chinese medicines (TCM). The quality of TCM has a direct impact on its efficacy. Therefore, in order to thoroughly reveal how TCM exerts its efficacy, first of all, it is necessary to understand the material basis for its efficacy, and then to control the quality of active compounds. The application of the spectrum-effect relationship method is crucial for determining the pharmacological material basis. The goal of this paper was to investigate the underlying correlations between the chemical profiles and oestrogenic activity of Cistanche, to reveal the active compounds. The chemical profiles of Cistanche were recorded using HPLC/Q-TOF-MS/MS, and oestrogenic activity was determined by the Uterus growth test and the MTT assay. Then combining the results of bivariate analysis, principal component analysis and gray correlation analysis method, fifteen active compounds were identified. They are 8-epiloganic acid, salidroside, syringalide A 3’-α-l-rhamnopyranoside, cistanoside A, echinacoside, cistanoside F, cistanoside B, cistanoside C, osmanthuside B, acteoside, isoacteoside, tubuloside B, 2’-acetylacteoside, and two unknown compounds. This study lays a foundation for in vivo studies of Cistanche and for the development of its clinical application.
Opponent portrait for multiagent reinforcement learning in competitive environment

Existing investigations of opponent modeling and intention inferencing cannot make clear descriptions and practical explanations of the opponent's behaviors and intentions, which may inevitably limit the applicability of them. In this work, we propose a novel approach for opponent's policy explanation and intention inference based on the behavioral portrait of opponent. Specifically, we use the multiagent deep deterministic policy gradients (MADDPG) algorithm to train the agent and opponent in the competitive environment, and collect the behavioral data of opponent based on agent's observations. Then we perform pattern segmentation and extract the opponent's behavior events via Toeplitz inverse covariance‐based clustering (TICC) algorithm; hence the opponent's behavior data can be encoded into a knowledge graph, named opponent's behavior knowledge graph (OKG). Based on this, we built a question‐answer system (QA system) to query and match opponent historical information in OKG, so that the agent can obtain additional experience and gradually infer the intention of opponent with the episodes of iteration. We evaluate the proposed method on the competitive scenario in multiagent particle environment (MPE). Simulation results show that the agents are able to learn better policies with opponent portrait in competitive settings.
Conformal Hermetic Sealing of Wireless Microelectronic Implantable Chiplets by Multilayered Atomic Layer Deposition (ALD)

A hermetic sealing method of sub‐millimeter‐sized microelectronic chiplets for wireless body implants is presented by ultrathin and electromagnetically transparent atomic layer deposition (ALD) coatings. Fully 3D conformal encapsulation of wirelessly powered microdevices is demonstrated both with and without opening windows for electrophysiological measurements. The chiplets embedding custom application‐specific integrated circuits (ASICs) with radio frequency (RF) transmitters are encapsulated by a stack of alternating layers of hafnium oxide and silicon dioxide to maximize impermeability of water and ionic penetration while minimizing the volume of the packaging material. The hermeticity of the devices is characterized through accelerated aging tests in saline at T = 87 °C, while continued functionality is monitored via evaluation of backscattered RF signals (near 1 GHz) to ascertain possible degradation and electronic failure. Earliest failures of wirelessly functional devices occur after more than 180 d of immersion at 87 °C. Wireless devices having opening windows through the ALD envelope show no signs of degradation for >100 d. This implies an equivalent lifetime >10 years at T = 37 °C. This approach is readily scalable to high throughput batch processing of hundreds of microchiplets, offering a methodology for hermetic packaging of microscale biomedical chronic implants.
A Virtual Reality Embodiment Technique to Enhance Helping Behavior of Police Toward a Victim of Police Racial Aggression

Abstract There is an alarming level of violence by police in the US toward African Americans. Although this may be rooted in explicit racial bias, the more intractable problem is overcoming implicit bias, bias that is non-conscious but demonstrated in actual behavior. If bias is implicit, it is difficult to change through explicit methods that attempt to change attitudes. We carried out a study using virtual reality (VR) with 38 officers in a US police department, who took part in an interrogation of an African American suspect alongside an officer who was racially abusive toward the suspect. Seventeen of the participants witnessed the interview again from a third person perspective (Observer) and 21 from the embodied perspective of the suspect, now a victim of the interrogation (Victim condition), having been assigned randomly to these two groups. Some weeks later, all witnessed aggression by an officer toward an African American man in a virtual cafe scenario. The results show that the actions of those who had been in the Victim condition were coded as being more helpful toward the victim than those in the Observer condition. We argue that such VR exposures operate at the experiential and implicit level rather than the explicit, and hence are more likely to be effective in combating aggression rooted in implicit bias.
What is the Purpose of this Meeting? The hidden meanings of the meeting announcement

This study examines the coincidence or discrepancy between the purpose of meetings stated in the organizer’s announcement and the purposes perceived by the participants. This analysis enriches and complexifies the view of meeting purposes in the literature. Based on structured questionnaire data from 1,946 respondents involved in 490 meetings conducted in the context of an international project, our analysis shows that the stated and perceived purposes of a meeting are not necessarily the same. In particular, a purpose expressed as a noun (e.g. Coordination) may be perceived by participants as various purposes expressed in verbs, that are strongly or weakly aligned with that noun (e.g. Socialize, Coordinate, Follow up or Persuade). This study establishes the need for a distinct line of research into the discrepancy between stated and perceived meeting purposes to understand meeting-related organizational dynamics, and it lays a basis for theorizing within that line of investigation by demonstrating an influence of the internal-external nature of meetings and the local culture. This study also highlights the core intermediation role of socialization for achieving the stated purposes of certain meeting types. Additionally, this study has immediate implications for organizing and managing meetings.
Effects of Sodium Sulfate and Sodium Chloride for Sonochemical Degradation on 1,4-benzoquinone and Hydroquinone in Aqueous Solution

1,4-benzoquinone, with the molecular formula C6H4O2, is generally known as a para-quinone. It is a six-member ring compound with an oxidized derivative known as 1,4-hydroquinone, which is a bright yellow crystal that has an irritating odour. On the other hand, hydroquinone, also known as benzene-1,4-diol, has the chemical formula C6H4(OH)2. It looks like a white granular solid. Quinone is generally used as a precursor to hydroquinone. The skeletal muscle relaxant, ganglion blocking agent, benzoquinonium, is made from benzoquinone. It is utilized to suppress double-bond migrations during olefin metathesis reactions. 1,4-benzoquinone is also used in the synthesis of Bromodol, while hydroquinone is the main ingredient in black-and-white photographic developers such as film and paper developers, where it diminishes the silver halide to elemental silver. There are various other uses related to this diminishing power. As a polymerization inhibitor, hydroquinone prevents the polymerization of methyl methacrylate, acrylic acid, etc. Studies have demonstrated the various effects of Na2SO4 and NaCl on the sonochemical degradation of 1,4-benzoquinone and hydroquinone using a 200-kHz sonicator. The highest degradation rate was obtained in the presence of 0.433 M Na2SO4 for 1,4-benzoquinone. After 30 minutes of ultrasonic irradiation, the total concentration of 1,4-benzoquinone decreased to 99% in the presence 0.433 M Na2SO4. Without Na2SO4, the sonochemical degradation rate of 1,4-benzoquinone was 4.5 times higher than that of hydroquinone, whereas in the presence of 0.433 M Na2SO4 under the same conditions the initial reaction rate of 1,4-benzoquinone was increased to become 10.6 times higher than that of hydroquinone. On the other hand, in the presence of NaCl, no effects were observed for the decomposition of hydroquinone but negative effects were clearly observed for the decomposition of 1,4-benzoquinone.
Procedural Knowledge of Primary School Teachers in Madagascar for Teaching and Learning towards Land-Use- and Health-Related Sustainable Development Goals

Achieving the Sustainable Development Goals (SDGs) requires the empowerment of learners through Education for Sustainable Development (ESD), already at primary level. Teacher education for the SDGs is a focus of ESD. However, many teachers in Madagascar are underqualified and show knowledge gaps regarding ESD. This paper aims at identifying starting points for an ESD-oriented further development of teacher training, considering regionally relevant issues. Teaching Sustainable Development issues requires procedural knowledge. This paper reports on (i) Malagasy primary school teachers’ (n = 286) teaching and learning prerequisites regarding land-use and health issues compared to expert knowledge, (ii) modeling teachers’ respective procedural knowledge with the Rasch Partial Credit Model and validation studies, and on (iii) comparison of groups of teachers differentiated by diversity dimensions, e.g., teaching at rural or urban schools. The teachers underestimated land-use and health courses of action regarding effectiveness and possibility of implementation, compared to experts. IRT modeling resulted in two distinct knowledge dimensions, i.e., land use and health (latent correlation: 0.31). Rural teachers showed higher procedural land-use knowledge than urban teachers. No differences occurred regarding health knowledge. The paper argues for ESD-focused reorientation of teacher training, considering regional specificities of land-use topics, e.g., regarding vanilla and rice cultivation in North-East Madagascar, and health topics.