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Many engineering applications include the heat exchange process between two fluids with distinct temperature gradients separated by solid walls. The machinery used in this operation is known as a heat exchanger. The interaction between exhaust gas and water was modeled in this study using a variety of heat exchanger types. The boundary conditions parameters of the input exhaust gas for the simulation model were established based on the test diesel engine. When the engine is operating at 1200 rpm and 100% load, modeling results show that the heat recovery efficiency of the exhaust gas reaches the maximum value of 65% thanks to the 9-compartment structure and one heat sink in each compartment.

The paper introduces a one-step projection method for solving a pseudomonotone equilibrium problem given by a sum of two bifunctions in Hilbert spaces. Compared with the existing splitting methods, our algorithm is simpler as it only requires one projection onto the feasible set at each iteration. Under standard assumptions, the weak convergence of the new algorithm is established. Besides, we present a strong convergence result of a regularized version of the proposed method. Finally, we perform two numerical examples to demonstrate the promise of the proposed algorithms.

This article investigates the performance of a multi-antenna unmanned aerial vehicle (UAV)-aided backscatter short packet communication (SPC) system. The energy and radio frequency (RF) for the operations of backscatter devices are supported by UAV, and finite block length data are transmitted via uplink. The block error rate (BLER), throughput, goodput, reliability, latency, and age of information (AoI) are used to evaluate the proposed system performance, where the closed-form BLER expressions are approximated by the Gaussian-Chebyshev quadrature with line-of-sight (LoS) and non-LoS (NLoS) probabilities. We formulate optimization problems to maximize the throughput subject to the number of transmit bits and the UAV altitude and to minimize BLER subject to the UAV altitude, then solve them by using the one-dimensional search method. Monte Carlo simulations verify the accuracy of analysis results. The results show that using multi-antennas and maximal-ratio transmission (MRT) significantly improves the BLER. In addition, choosing a suitable altitude of UAV and relevant transmission bit can provide the best BLER and throughput or goodput. Finally, the impacts of UAV velocity, the operating environments, and LoS probability on the system performance are significant.

In this article, we utilize multiple reconfigurable intelligent surfaces (RISs) to improve the secrecy performance of non-orthogonal multiple access (NOMA) systems. In particular, multi-RIS is exploited to aid two legitimate NOMA users under the existence of colluding eavesdroppers. We successfully derive the mathematical expressions of the secrecy outage probabilities (SOPs) and ergodic secrecy capacities (ESCs) of the proposed systems under realistic Nakagami-$m$ channels recommended for the fifth and beyond generation (5 G & B5G) wireless networks. Numerical results confirm the enormous benefits of the proposed systems compared to the classical NOMA systems with multiple eavesdroppers and without RISs. More specifically, compared to the classical NOMA systems, the SOPs of the proposed systems are considerably lower, while the ESCs are dramatically higher. In addition, the transmit power to obtain the lowest SOPs of the proposed systems is lower than that to get the lowest SOPs of the classical NOMA systems. On the other hand, the effects of many crucial parameters, such as the carrier frequencies of Wi-Fi systems, the fading order, and the distances between transmitter-receiver, are thoroughly examined to obtain the behaviors of the proposed systems. Finally, Monte-Carlo simulations are provided to validate the derived expressions.

This study investigates the role of financial development in the effect of exchange rate volatility on capital inflows. The threshold methodology and GMM estimation are employed to analyse the panel dataset of 20 emerging countries from 2010 to 2019. Two types of inflows are involved in the studies including foreign direct investment and portfolio investment to examine the responses of different inflows to exchange rate risk. Financial development is measured by two traditional indices including ratios of broad money to GDP and domestic credit to GDP. The results indicate a negative relationship between exchange rate volatility and capital inflows. However, financial development can reduce the detrimental influence of exchange rate volatility on capital inflows. This result suggests an improvement of financial development is necessary for diminishing the negative effect of exchange rate volatility. Emerging countries with low financial development should stabilise the exchange rate to attract more capital inflows.

An old generation diesel engine running on dual-fuel dimethyl ether (DME) and diesel was tested for pollution reduction and performance enhancement. DME was pre-mixed with intake air using a single-port gaseous fuel injection system to replace 5% (DME5) and 10% (DME10) diesel. Study results show that the fuel economy improves when the engine operates with dual fuel. The brake-specific energy consumption reduces by 2.5% and 3.0% at full load condition and 4.5% and 5.1% at a medium speed of 1600 rpm on average for DME5 and DME10 compared to pure diesel case. The in-cylinder pressure, temperature, and vibration rate were evaluated to determine DME's effect on engine combustion. The impact of DME was noticeable as exhaust pollutants enhanced remarkably for NOxand smoke components. When the engine was fueled with DME5 and DME10, the specific particulate matter fell dramatically by 32.90% and 50.23%, NOxdeclined moderately by 8.66% and 20.39%.

AbstractAchieving sustainable development goals (SDGs) is a global requirement that attracts new researchers and regulators. So, the current research investigates the impact of investment on the environment, social, and governance (ESG) activities on the achievement of SDGs of the Chinese manufacturing companies. The current article also examines the mediating impact of organizational effectiveness among the nexus of investment in ESG activities and the achievement of SDGs of the Chinese manufacturing companies. The current research has taken the questionnaires to gather the data and used the smart-PLS to analyze the data. The results exposed that investment in the environment and social activities have a positive impact on the achievement of SDGs. The findings also revealed that the organizational effectiveness significantly mediates among the nexus of investment in the environment and social activities and the achievement of SDGs of the Chinese manufacturing companies. This study provides help to the relevant authorities to achieve the SDGs using the investment in ESG activities.

Corynespora cassiicolais a causal agent of Corynespora leaf fall disease (CLFD) in Hevea brasiliensis. This pathogen attacks the host cells using a small-secreted glycoprotein named cassiicolin that has been demonstrated to be an important effector during the infection process of C. cassiicola. Cassiicolin-encoding genes were identified and their virulence was evaluated in rubber varieties. Identification of Casgenes was conducted using seven pairs of primers on 24 C. cassiicolaisolates collected from rubber plantations in Vietnam. Only two pairs of primers including F1CasU1-2–6 and R1CasU1-2–6 (Cas1, Cas2, Cas6) and CasF17 and CasR24 (Cas2) were able to amplify target PCR fragments. BLAST and phylogenetic analyses indicated that six C. cassiicolaisolates carried the sequences of the Cas2 gene and showed the same group with the Cas2 sequences from Brazil. The link between cassiicolin encoding genes and fungal virulence remains unclear but the Cas2 gene also showed severe fungal virulence on rubber varieties in Vietnam. Results supported the prediction of fungal virulence of C. cassiicolaisolates from Vietnam and will assist in finding appropriate approaches to efficiently control CLFD in Vietnamese rubber plantations.

DNA functions only in aqueous environments and adopts different conformations depending on the hydration level. The dynamics of hydration water and hydrated DNA leads to rotating and oscillating dipoles that, in turn, give rise to a strong megahertz to terahertz absorption. Investigating the impact of hydration on DNA dynamics and the spectral features of water molecules influenced by DNA, however, is extremely challenging because of the strong absorption of water in the megahertz to terahertz frequency range. In response, we have employed a high-precision megahertz to terahertz dielectric spectrometer, assisted by molecular dynamics simulations, to investigate the dynamics of water molecules within the hydration shells of DNA as well as the collective vibrational motions of hydrated DNA, which are vital to DNA conformation and functionality. Our results reveal that the dynamics of water molecules in a DNA solution is heterogeneous, exhibiting a hierarchy of four distinct relaxation times ranging from ∼8 ps to 1 ns, and the hydration structure of a DNA chain can extend to as far as ∼18 Å from its surface. The low-frequency collective vibrational modes of hydrated DNA have been identified and found to be sensitive to environmental conditions including temperature and hydration level. The results reveal critical information on hydrated DNA dynamics and DNA-water interfaces, which impact the biochemical functions and reactivity of DNA.

ABSTRACTThis study aims to develop the models of emission and fuel consumption during idling of motorcycles (MCs) in Hanoi, including the unsteady and steady idling stages. Five MC models commonly used in Hanoi were selected to measure the instantaneous emission and fuel consumption rates under the controlled conditions at the laboratory conditions. The instantaneous emission and fuel consumption models during idling were developed for the test MCs in the unsteady idling stage. The R2of obtained models are higher than 0.9. The average emission and fuel consumption rates in the steady idling stages were determined. The average idling emissions of pollutants CO, CO2, HC and NOxwere 60.9, 534.3, 10.3 and 1.8 g/h, respectively. The average fuel loss during idling is around 180 g/h. The emission released from the MC fleet in Hanoi during idling was estimated for the year 2018. The total idling emissions from the MC fleet of 3.9 million vehicles in the year 2018 of CO, CO2, HC and NOxwere 6.5, 57.1, 1.1 and 0.2 kt, respectively. The total fuel loss during idling of the MC fleet in 2018 was ∼19.3 kt. The air pollutants eliminated in the idle mode as CO, CO2, HC and NOxcontributed 2.23%, 3.19%, 1.14% and 1.03%, respectively, of the total emission from the MC fleet in Hanoi.Abbreviations:CVT: continuously variable transmission; TWC: three-way catalytic; CVS: constant volume sampler; FR: fuel consumption rate; IR: infrared sensor; MC: motorcycleHighlightsThe difference in the fuel used between steady and unsteady idle stages was identified.The instantaneous emission and fuel used models for unsteady idling were developed.The total fuel loss during idling of the motorcycle fleet in Hanoi was estimated.The total pollutant during idling of the motorcycle fleet in Hanoi was calculated.

In this work, the monodisperse Fe3O4@Ag core‐shell hybrid nanoparticles (NPs) with an average size of 16.0 nm have been successfully fabricated by the seeded‐growth method in the organic solvent. The influence of the molar ratios of AgNO3/OLA on the formation of hybrid NPs has been investigated in detail to find the optimal conditions for the synthesis of the desired Fe3O4@Ag hybrid NPs. The hydrophobic Fe3O4@Ag hybrid NPs were successfully transferred into the water using poly (maleic anhydride‐alt‐1‐octadecene) (PMAO). The PMAO coated Fe3O4@Ag nanoparticles were well dispersed and stable in water over a wide range of pH from 2 to 11 as well as reasonable electrolyte concentration. The Fe3O4@Ag magneto‐plasmonic design can efficiently combine magnetic hyperthermia into an effective bimodal thermo‐therapy.

Insight into the phase-dependent electron transfer kinetics and electrocatalytic activity of metal oxide nanostructures is important in the rational design of functional nanostructures for realizing high-performance electrochemical sensors. This study focuses on elucidating the effect of the crystalline phase on the electron transfer kinetics and electrocatalytic activity of iron(III) oxide. The α-FeOOH, γ-Fe2O3, and α-Fe2O3nanorods were designed by using a simple chemical method and calcining process. The phase-dependent difference in the electron transfer kinetics and electrocatalytic activity toward the sensitive response of chloramphenicol (CAP) is observed by the transformation from α-FeOOH to γ-Fe2O3, and from α-FeOOH to α-Fe2O3nanorods. We found that the oxygen vacancies formed in phase transformation from α-FeOOH to α-Fe2O3is a key factor in promoting the electrochemical reduction of chloramphenicol. The α-Fe2O3nanorods-based electrochemical sensors showed a linear response in the CAP concentration range from 0.1 to 75 μM with a limit of detection of 60 nM and an electrochemical sensitivity of 2.86 μA μM−1cm−2. This work further provides valuable physical insight into the phase-dependent electron transfer kinetics and electrocatalytic activity of metal oxide nanostructures for the rational design of sensing interface.

The present work deals with multi-objective optimization of powder mixed electric discharge machining (PMEDM) when processing cylindrically shaped parts. In this work, the pulse on time Ton, the pulse off time Toff, the powder concentration Cp, the pulse current IP, and the server voltage SV were chosen for the optimization problem. Also, the surface roughness (SR), the material removal rate (MRR), and the electrode wear (EW) were chosen as three objectives for the investigation. Besides, the Taguchi method and the grey relational analysis (GRA) were applied for optimizing simultaneously three the SR, the MRR and the EW to find the optimum input factors. The impact of the process parameters on the overall goal was weighed. Additionally, optimum input factors of PMEDM process for multi-objectives were recommended.

This study aims to minimize electrode wear (EW) and maximize material removal rate (MRR) in powder mixed electrical discharge machining (PMEDM) process of 9CrSi alloy steel with silicon carbide powder. To achieve these objectives, Taguchi method and Grey Relational Analysis (GRA) are applied to optimize one two-level and four three-level PMEDM process parameters, including Ton, Toff, CP, IP and SV in eighteen experiments based on an orthogonal array L18 (21 and 43). Results have provided a set of optimal PMEDM process parameters in which Ton has the strongest effect on SW and MRR while that of CP is insignificant. The obtained minimum EW and maximum MRR have been verified and proven by a PMEDM experiment using optimal process parameters. The proposed method can be further applied to optimize other PMEDM process parameters for different objectives.

In the modern navigation system, the height channel is always the most unstable channel. Combination processing the height measurement signals by using the Kalman filter algorithm can improve the precision of the high measurement. However, in the process of performing the signal processing algorithm by using the Kalman filter, the transition time to obtain the set status is long. Moreover, within different flight conditions, the inertia height meter will be combined with the supporting height meter to get the structure of the combination height meter in order to process the height measurement signals more precisely. In this article, the authors proposed using the criterion for evaluating the observable level to improve the quality of height measurement signal processing. The research results were simulated on three combined high measurements, in which the inertia height meter (IHM) (the basic meter) was combined with one or two supporting height meters (the radio height meter [RHM] and the barometer [AHM]) to show the correctness of the proposed algorithm.

This paper deals with the effect of input parameters of Powder Mixed Electric Discharge Machining (PMEDM) process on the surface roughness when processing cylindrical shaped parts. In this work, the workpiece material is 90CrSi alloy tool steel and the nanopowder is silicon carbide. Also, five input parameters including the pulse on time, the pulse off time, the powder concentration, the current and the server voltage were selected to investigate their influence on the surface roughness. Taguchi method and ANOVA analysis were used and the effect of input parameters on the surface roughness was presented. Moreover, optimum input parameters for minimum surface roughness was suggested.

This paper explores a new perspective of finding the best tournament structures by focusing on two aspects (apart from the number of matches): competitiveness development and ranking precision. Competitiveness development emphasizes the importance of participants’ motivation while keeping the matches exciting whereas ranking precision reflects the persuasiveness of tournament result to its participants. To address competitiveness development, this paper proposes a new method that visualizes tournament structures using a tree-like graphical model called progress tree. In addition, ranking precision is addressed by considering the similarities and qualities of the ranking process by the sorting algorithm during the ranking process. With respect to these two aspects, several well-known tournament structures such as the single elimination, double elimination, Round-Robin, and Swiss systems were analyzed. Although each tournament has its own pros and cons, none of them can thoroughly convince all participants of the tournament results while keeping the matches strongly motivating. As such, a new tournament structure called Reapertournament system with its variants, are proposed. The Reapertournament system with its variants were evaluated on simulated football matches and validated with real-world data of previous football tournaments. Thence, practical insights into tournament structures are obtained and possible future works are discussed.

Mental disorders are the leading global cause of health burden among adolescents. However, prevalence data for mental disorders among adolescents in low-income and middle-income countries are scarce with often limited generalisability. This study aimed to generate nationally representative prevalence estimates for mental disorders in adolescents in Kenya, Indonesia, and Viet Nam.

This study proposes a facile method for superhydrophobic and slippery-infused porous surfaces for water repellency and anti-icing purposes. Both adhesion force and time delaying were systematically investigated, showing their strong dependence on surface parameters and slipperiness. The uniform patterns of nanoscale textures inspired by rose leaf structure have been generated on silicon wafers using the plasma etching process. We believe the lower real contact area can play a dual role in the icing mechanism including reducing heat transfer and adhesion force attributed to the projected area. On the other hand, slipperiness plays an important role in reducing adhesion strength and preventing ice nucleation. The slippery superhydrophobic surface demonstrates outstanding in reducing the adhesion strength while documenting several times lower compared to bare Si, superhydrophobic Si, and slippery Si surfaces. In addition, the rational combination facilitates the efficient function after a number of test cycles, illustrating the mechanical anti-corrosion properties. The results lead to understanding the role of the icing process and designing the anti-icing structure.

We report relaxation dynamics of glycerol–water mixtures as probed by megahertz-to-terahertz dielectric spectroscopy in a frequency range from 50 MHz to 0.5 THz at room temperature. The dielectric relaxation spectra reveal several polarization processes at the molecular level with different time constants and dielectric strengths, providing an understanding of the hydrogen-bonding network in glycerol–water mixtures. We have determined the structure of hydration shells around glycerol molecules and the dynamics of bound water as a function of glycerol concentration in solutions using the Debye relaxation model. The experimental results show the existence of a critical glycerol concentration of ∼7.5 mol %, which is related to the number of water molecules in the hydration layer around a glycerol molecule. At higher glycerol concentrations, water molecules dispersed in a glycerol network become abundant and eventually dominate, and four distinct relaxation processes emerge in the mixtures. The relaxation dynamics and hydration structure in glycerol–water mixtures are further probed with molecular dynamics simulations, which confirm the physical picture revealed by the dielectric spectroscopy.

We introduce two new algorithms based upon the extragradient and inertial methods for solving pseudomonotone equilibrium problems in real Hilbert spaces. Strong converge and weak convergence of the proposed algorithms are established under some mild assumptions. Numerical results show that the proposed algorithms are more efficient than some existing methods for equilibrium problems.

In this paper, we propose a CQ-type algorithm for solving the split feasibility problem (SFP) in real Hilbert spaces. The algorithm is designed such that the step-sizes are directly computed at each iteration. We will show that the sequence generated by the proposed algorithm converges in norm to the minimum-norm solution of the SFP under appropriate conditions. In addition, we give some numerical examples to verify the implementation of our method. Our result improves and complements many known related results in the literature.

AbstractIntroductionVery Brief Advice (VBA) on smoking is an evidence-based intervention and a recommended clinical practice for all healthcare professionals in the UK.AimsWe report on experience from the FRESH AIR project in adapting the VBA model and training in three low-resource settings: Greece, Vietnam and Kyrgyzstan.MethodsUsing a participatory research process, UK experts and local stakeholders conducted an environmental scan and needs assessment to examine the VBA intervention model, training materials and recommend adaptations to the local context. Two VBA training sessions were piloted in each country to inform adaptation. A final training tool kit was developed in the local language.ResultsIn each country, the VBA on smoking intervention model remained primarily intact. The lack of a formal smoking cessation system to refer motivated clients in two countries required adaptation of the ACT component of the model. A range of local adaptations to the training resources were made in all three countries to ensure cultural appropriateness as well as enhance key messages including expanding training on nicotine addiction, second-hand smoke and pharmacotherapy.ConclusionsImplementation of VBA requires sensitive, collaborative, local and cultural adaptation if it is to be achieved successfully.Trial registrationTrial ID# NTR5759Critical appraisal toolsThe Standards for Reporting Implementation Studies (StaRI) statement: https://www.equator-network.org/reporting-guidelines/stari-statement/

In this study, goethite nanoparticles were successfully synthesized by chemical precipitation approach with the assistance of microwave aimed to adsorb heavy metals from water. The phase and morphology of the obtained sample was characterized using XRD and SEM methods. The feasibility of goethite nanoparticles for Pb(II) and Cd(II) removal from aqueous solution was evaluated. The effects of pH, contact time, and initial heavy metals concentrations were investigated. The adsorption of Pb(II) and Cd(II) on goethite remarkably depended on the pH of the solution and contact time. Adsorption kinetics for both metals obeyed the pseudo‐second‐order and the adsorption data fit well with the Langmuir adsorption model. The maximum adsorption of Pb(II) and Cd(II) on goethite nanoparticles was 111.11 and 76.92 mg.g‐1at pH 5.5 after 120 and 90 min of the contact time, respectively.

Avicennia officinalisL., Avicenniaceae,is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia,… A. officinalis’schemical compositions remain mostly unknown. Therefore, we now report on the structural elucidation of six compounds isolated from this plant growing in Can Gio mangrove forest in Ho Chi Minh City by using a variety of chromatographic techniques. The structures of these compounds were elucidated by NMR spectroscopy analysis as well as compared with data in the literature. They areaviridoid(1), (1S,5R,8S,9R)‐2'‐(E‐coumaroyl)mussaenosidic acid (2), velutin (3), α‐tocopherol (4), and a mixture of 6‐methoxynaphtho[2,3‐b]‐furan‐4,9‐quinone (5)and 7‐methoxynaphtho[2,3‐b]‐furan‐4,9‐quinone (6). To the best of our knowledge, (1)is a new compound while (2), (4), (5)and (6)are obtained from Avicenniagenus for the first time. Further studies on this species are in progress.