Journal Articles - Engineering Technology - 2022

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  • Publication
    Regularization of the backward stochastic heat conduction problem
    ( 2021)
    Nguyen Huy Tuan
    ;
    Daniel Lesnic
    ;
    Tran Ngoc Thach
    ;
    Tran Bao Ngoc
    In this paper, we study the backward problem for the stochastic parabolic heat equation driven by a Wiener process. We show that the problem is ill-posed by violating the continuous dependence on the input data. In order to restore stability, we apply a filter regularization method which is completely new in the stochastic setting. Convergence rates are established under different a priori assumptions on the sought solution.
  • Publication
    Speckle Pattern Inversion in High Temperature DIC Measurement
    ( 2021)
    T.Q. Thai
    ;
    J. Ruesch
    ;
    P.R. Gradl
    ;
    T.T. Truscott
    ;
    R.B. Berke
    During hot fire rocket engine testing, non-contacting measurements are superior to bonded gauges because they are immune to burning, shaking loose, or damage due to the harsh testing conditions. Additionally, when compared to instruments which register at single points, Digital Image Correlation (DIC) has the added benefit in that it collects full-field displacement and strain maps over the duration of the test. However, for certain materials and paints under some circumstances of temperature and camera sensitivity, portions of the speckle pattern which were darker at room temperature may emit more light compared to the initially lighter portions of the pattern, resulting in a high temperature pattern which is inverted in comparison with that at room temperature. To address this inversion, a post-processing method is introduced wherein an inverted image containing only emitted light is subtracted from an image containing both emitted and reflected light, thereby generating an un-inverted image. The artificial high temperature image is subsequently correlated against the room temperature image to obtain full-field strains. The subtraction technique is then validated using optical bandpass filters to prevent significant amounts of emitted light from reaching the camera sensor. The two methods are mapped onto common coordinates and shown to produce comparable results. The subtraction method sufficiently mitigates speckle pattern inversion, but its key drawback is that it only works when there is negligible displacement between the subtracted images (i.e. quasi-static loading). It is therefore preferable to eliminate inversion from reaching the camera in the first place by using optical bandpass filters.
  • Publication
    Intelligent Reflecting Surface Aided Wireless Systems with Imperfect Hardware
    ( 2022)
    Nhan Duc Nguyen
    ;
    Anh-Tu Le
    ;
    Munyaradzi Munochiveyi
    ;
    Fatemeh Afghah
    ;
    Evangelos Pallis
    In this article, we investigate the design of reconfigurable intelligent surface (RIS)-aided transmission as a smart method to reflect signals received from access points to users and, hence, improving users’ performance. To implement smart Internet of Things (IoT) networks, massive connectivity and low-cost deployment are essential in designing such systems. In particular, we consider two practical scenarios (dual-hop and single-hop transmissions). These scenarios highlight the potential of RIS in enhancing the system’s outage probability performance. Furthermore, to characterize channel conditions in practice, we pay particular attention to two-channel distributions that are non-central chi-square (NCCS) distributions that approximate the channel distribution of the RIS-aided wireless system and the squared KG distribution. In addition, the RIS-aided system may face imperfect hardware-related issues in practice. Therefore, we need to consider the degraded performance of practical RIS-aided systems by considering the detrimental impact of in-phase and quadrature-phase imbalance (IQI). To characterize the main system performance metric, we provide closed-form formulas of outage probability and ergodic capacity. We then evaluate system performance under the impacts of signal-to-noise ratio (SNR), the number of meta-surfaces, and channel parameters. All closed-form outage expressions are validated via Monte Carlo simulations. Simulation results indicate that the considered RIS scheme at dual-hop and single hop under the impact of IQI and RIS hardware impairment achieves significant improvements in terms of outage probability at high SNR and high meta-surface number N. Additionally, the simulation results demonstrate that the impact of IQI on the proposed system is limited. It is worth noting that, in terms of ergodic capacity, ergodic capacity faces an upper limit. Despite this limitation, the proposed system can still work well once some parameters are controlled well, such as the transmit SNR, levels of IQI, and the number of RIS components.
  • Publication
    NEW RESULTS FOR PARABOLIC EQUATION ON THE SPHERE WITH CAPUTO–FABRIZIO OPERATOR
    ( 2022)
    NGUYEN ANH TUAN
    ;
    NGUYEN HOANG LUC
    ;
    NGUYEN PHAM QUYNH TRANG
    ;
    HO THI KIM VAN
    In this paper, we are interested in studying the initial value problem for parabolic problem associated with the Caputo–Fabrizio derivative. We deal the problem in two cases: linear inhomogeneous case and nonlinearity source term. For the linear case, we derive the convergence result of the mild solution when the fractional order [Formula: see text] under some various assumptions on the initial datum. For the nonlinear problem, we show the existence and uniqueness of the mild solution using Banach fixed point theory. We also prove the convergence result of the mild solution when the fractional order [Formula: see text].
  • Publication
    Dy3+-doped P2O5–Al2O3–K2O–CaF2–LiF glasses: thermal, spectroluminescence and photometric properties
    ( 2022)
    K Kiran Kumar
    ;
    Ramachari Doddoji
    ;
    V B Sreedhar
    ;
    Nguyen Thi Quynh Lien
    ;
    Ho Van Tuyen
    ;
    Vasudeva Reddy Minnam Reddy
    Fluorophosphate (PAKCLf: P2O5-Al2O3-K2O-CaF2-LiF) glasses with Dy3? concentration of 0.01, 0.05, 0.1, 0.5, 1.0, 2.0 and 3.0 mol% were fabricated by pouring the melt and sudden quenching process. The glass stability factor of 106 C was calculated by glass transition (563 C) and crystallite (669 C) temperatures. The energy bandgap (Eg) of Dy3?:PAKCLf glasses is calculated for (ahm)2 (direct) and (ahm)1/2 (indirect) allowed transitions. From optical absorption, the oscillator strength and spectroscopic intensity (X2,4,6) parameters by performing Judd–Ofelt calculations were estimated to evaluate the radiative transition properties of 4F9/2 level in Dy3? ions. The emission spectra consist of two intense bands in blue (485 nm: 4F9/2?6H15/2) and yellow (576 nm: 4F9/2?6H13/2) regions by stimulating at 349 nm. The decay curves demonstrate the non-exponential nature from 0.5 to 3.0 mol% of Dy3? and fitted well to the Inokuti–Hirayama model. The findings of stimulated emission cross-section (5.20 9 10–21 cm2), optical gain (29.59 9 10–25 cm2s), and quantum efficiency (97%) for Dy3?:PAKCLf glasses could be potentially utilized as optical devices. The photometric parameters like CIE colour coordinates and correlated colour temperatures (CCT:6300-6900 K) of Dy3?:PAKCLf glasses reveal the application of white light-emitting diodes.
  • Publication
    Coal Fly Ash slag and Slag based Geopolymer as An Absorbent for The Removal of Methylene Blue in Wastewater
    ( 2022)
    Nguyễn Đăng Khoa
    The fly ash and slag from coal burning were attractive byproducts to prepare geopolymers for the adsorption of methyelen blue in wastewater due to their availability and low cost. Various mixing amounts between them were conducted during geopolymerization with a Na2SiO3/NaOH ratio of 10 M of 2.5 and a curing temperature of 60◦C for 24 h. When the amount of coal slag in the geopolymer composition was increased from 0 to 51 %, the surface structures of the resultant geopolymers were much softer and more porous due to the lack of initial material, causing a reduction in the surface area of geopolymers to 119,23 m2/g for 0 % and 5,29 m2/g for 51 %. The adsorption amount of methylene blue performed at pH 12 showed different tendencies on the dependence of contact time for the indivually prepared geopolymer. The uptake amount decreased from 36.2 mg/g to 34.2 mg/g with the enhancement of coal slag in the geopolymer from 0 to 51 % after 180 minutes of immersion in methylene blue solution. In addition, the adsorption mechanism evaluated by FT-IR spectroscopy was observed to involve electrostatic forces formed by hydrogen bonding between hydroxyl groups (Si–OH) and nitrogen atoms in the structure of methylene molecules. This study indicated that coal slag could be a potential material to prepare geopolymers for removing dye pollutants.
  • Publication
    Marine Predator Optimization Algorithm for Economic Load Dispatch Target Considering Solar Generators
    ( 2022)
    Nguyễn Văn Bình
    This paper implements Marine predator optimization algorithm (MPA) to seek the optimal solutions of thermal plants (TPs) for a conventional ELD problem and a hybrid ELD (HELD) problem considering solar generators. MPA has a strong and stable search ability by using Brownian distribution and Lévy flights distribution. For testing MPA, four test systems with different constraints and difficult levels are used. In which, the last two systems formed from the first two ones, are first proposed and utilized to analyze the effectiveness of renewable energy resources as installed on the power system. The optimal solutions obtained by running MPA on Systems 1 and 2 are employed to compare with many previous optimization methods. As a result, it can lead to a conclusion that MPA is more effective and stronger than compared methods in terms of solution quality and stable search ability. MPA successfully solves Systems 3 and 4 of the HELD problem considering solar generators. In addition, from analyzing cost reduction level of cases with and without solar generators, it can offer a useful idea that the use of renewable energy resources significantly decreases a cost of buying fossil fuels for TPs.
  • Publication
    A novel gold nanoparticle-based colorimetric assay for highly sensitive detection of ascorbic acid
    ( 2022)
    Thi Hong Anh Nguyen
    ;
    Vu Tuyet Mai Nguyen
    ;
    Van Thuan Le
    ;
    Van-Dat Doan
    ;
    Tan Phat Chau
    ;
    Van Cuong Nguyen
    ;
    Anh-Tien Nguyen
    ;
    Yasser Vasseghian
    In this study, a novel approach for colorimetric detection of ascorbic acid (AA) was proposed based on the peroxidase-like activity of gold nanoparticles, which were synthesized using Oldenlandia corymbosa leaves extract (OC-AuNPs). The OC-AuNPs synthesis was optimized at 0.5 mM Au3+, a reaction time of 20 min, and a temperature of 60 °C. The results showed that the biogenic OC-AuNPs presented as highly-efficient peroxidase mimics for catalyzing H2O2 to oxidize 3,3′,5,5′-tetramethylbenzidine forming a typical blue product with the characteristic absorption at 654 nm. The developed colorimetric method exhibited high sensitivity for AA with a detection limit of 0.26 μM in the linear range of 0 – 100 μM. The proposed assay can be serviced as a sensitive biosensor for the determination of AA in aqueous solutions due to its simple detection procedure, fast operation, and high sensitivity.
  • Publication
    Phytoremediation potential of Gossypium hirsutum on abandoned polluted chromium sludge soil with the amalgamation of Streptomyces tritici D5
    ( 2022)
    Mathiyazhagan Narayanan, Indira Karuppusamy, Maha Alshiekheid, Amal Sabour, Nguyen Thuy Lan Chi, Arivalagan Pugazhendhi
    The phytoremediation potency of Gossypium hirsutum was explored in this research under the influence of preidentified metal tolerant Streptomyces tritici D5 in Cr enriched sludge soil using various treatment sets (I to V) in a greenhouse setting. Interestingly, the G. hirsutum remarkable remediate the Cr metal from the Cr enriched sludge soil under diluted (50:50) condition in 90 days of greenhouse experiment. The S. tritici D5 also effectively support the growth and phytoremediation competence of G. hirsutum. This was evidenced by the under the diluted (set III) condition the growth and major biomolecules such as protein, carbohydrate, and chlorophyll content of G. hirsutum were considerably increased in quantity. Hence, the phytoremediation potential of G. hirsutum was effective at soil diluted with fertile and xenobiotics free soil with dilution ratio of 50:50 (set III) and followed by 75:25 (set II) ratio. Thus, under diluted conditions (50:50) G. hirsutum seed coated with S. tritici D5 showed an outstanding phytoremediation process. Therefore, this method can be implemented to the field level study to assess the metal removal prospects of this environmentally friendly method.
  • Publication
    On a terminal value problem for parabolic reaction–diffusion systems with nonlocal coupled diffusivity terms
    ( 2022)
    Nguyen Huy Tuan
    ;
    Tomás Caraballo
    ;
    Phan Thi Khanh Van
    ;
    Vo Van Au
    In this article, we are interested in investigating the nonlocal nonlinear reaction–diffusion system with final conditions. This problem is called backward in time problem, or terminal value problem which is understood as redefining the previous distributions when the distribution data at the terminal observation are known. There are three main goals presented in this paper. First, we prove that the problem is ill-posed (often called as unstable property) in the sense of Hadamard. Our next propose is to provide a modified quasi-reversibility model to stabilize the ill-posed problem. Using some techniques and tools of Faedo–Galerkin method, we prove the existence of the unique weak solution of the regularized problem. Further, we investigate error estimates between the sought solution and the regularized solution in and norms. The final aim of this paper is to give some numerical results to demonstrate that our method is useful and effective.
  • Publication
    In vitro analysis of green synthesized copper nanoparticles using Chloroxylon swietenia leaves for dye degradation and antimicrobial application
    ( 2022)
    Yan Yuan, Yingji Wu, V. Chinnadurai, Mythili Saravanan, Arunachalam Chinnathambi, Sulaiman Ali Alharbi, Kathirvel Brindhadevi, Nguyen Thuy Lan Chi, Arivalagan Pugazhendhi
    Green fabrication of copper nanoparticles (CuNPs) is an environmentally friendly and cost-effective method of synthesis for biomedical and bioremediation applications. In recent times, bacterial pathogens contaminating or affecting food and food crops pose the greatest threat to the food industry. In addition to this issue, synthetic dyes released from the textile and dyeing industries are polluting aquatic ecosystems and agricultural lands. The combined impact of these two factors is considered a major threat to life. Therefore, the use of CuNPs will provide an effective and long-term solution as an antibacterial and dye removing agent. The current study focuses on the synthesis of CuNPs using the leaf extract of Chloroxylon swietenia (C-CuNPs). The formation of a peak at 390 nm and a change in color from yellow to dark brown confirmed the synthesis of C-CuNPs. Subsequent synthesis at pH 9 was suitable for preparing C-CuNPs. Structural and chemical characterization of C-CuNPs was performed using Fourier Transfer Infra-Red (FTIR), X-ray diffraction (XRD), Dynamic Light scattering (DLS), and Scanning Electron Microscopy (SEM) analysis. The synthesized C-CuNPs possess a crystalline nature, a functional group that resembles C. swietenia, and are negatively charged and spherical in shape. C-CuNPs were tested against Congo red, Coomassie blue, and crystal violet and they showed complete degradation within 24 h under optimum conditions. Disk diffusion and broth dilution assay were used to test the antibacterial activity of CCuNPs against Staphylococcus nepalensis, Staphylococcus gallinarum, Pseudomonas stutzeri, Bacillus subtilis, and Enterococcus faecalis. Therefore, the present study represents the first report on C-CuNPs’ ability to degrade synthetic dyes and kill foodborne bacterial pathogens. Thus, the study has shed light on the potential of green synthesized CuNPs as bioremediation and packaging material in the future.
  • Publication
    Sustainable bioremediation approach to treat the sago industry effluents and evaluate the possibility of yielded biomass as a single cell protein (SCP) using cyanide tolerant Streptomyces tritici D5
    ( 2022)
    Wongchai Anupong, Khumchai Jutamas, Ruangwong On-uma, Amal Sabour, Maha Alshiekheid, Indira Karuppusamy, Nguyen Thuy Lan Chi, Arivalagan Pugazhendhi
    This sustainable approach was performed to evaluate the bioremediation potential of cyanide resistant bacterial species on sago industry effluents and assess the possibility of using the yielded biomass as single cell protein (SCP). The predominant cyanide tolerant bacterium enumerated from muddy soil was identified as Streptomyces tritici D5 through 16S rRNA sequencing. The identified S. tritici D5 strains showed excellent resistant and degradation potential at 100 mM concentration of potassium cyanide. Furthermore, the physicochemical properties analysis of sago industry effluents results revealed that the most of the parameters were crossing the permissible limits of Pollution control board of India. The bioremediation process was performed at various temperatures at 25 ◦C, 35 ◦C, and 45 ◦C for a period of 30 days of continuous bioremediation process with the aid of an aerator. Surprisingly, the best organic pollutant reduction was found at 35 ◦C and 45 ◦C, with 25 ◦C following close behind. Remarkably, the dissolved oxygen (DO) level was gradually increased from 2.24 to 12.04 mg L􀀀 1 at 35 ◦C in 30 days of the remediation process. The pH and ammonia were also significantly increased during the bioremediation process in 30 days of treatment. Similarly, at 35 ◦C of bioremediation process the S. tritici D5 yielded maximum dried biomass (6.9 g L􀀀 1) with the total crude protein (SCP) as 4.8 g L􀀀 1 (69.56%) in 30 days of growth. These findings stated that S. tritici D5 can treat sago industry effluents and that the biomass produced may be considered SCP after some in-vitro and in-vivo analyses.
  • Publication
    Drivers of climate change in selected emerging countries: the ecological effects of monetary restrictions and expansions
    ( 2022)
    Thanh Phuc Nguyen, Tho Ngoc Tran, Thi Thu Hong Dinh, Tri M. Hoang & Trang Duong Thi Thuy
    Drivers of environmental quality have recently been identified in a large body of literature. However, the ecological effects of both regimes of monetary policy remain under-explored so far. Moreover, previous studies use limited samples and econometric approaches. Climate change from the empirical perspective of the country’s monetary policy has recently become a promising avenue to investigate. Motivated by the aforementioned research gaps and increasing attention from energy researchers and policy-makers, this research aims to test the monetary restrictions and expansion on climate change represented by CO2 emissions, after controlling other significant drivers. We use a dataset from 1998 to 2018 for a sample of 14 selected emerging economies and quantitatively advanced techniques for panel data analysis, such as Ordinary Least Squares (OLS), Dynamic OLS, Fully-Modified OLS, and Panel Quantile Regression. We also use a two-step system generalized method of moments to avoid concerns about endogeneity and heteroskedasticity issues. We find strong evidence that contractionary and expansionary monetary policy both eliminate and escalate the environmental degradation through an increase in CO2 emissions, respectively. Moreover, these ecological effects of monetary policy interestingly appear in the middle and large quantiles of CO2 levels. Based on these findings, the research offers some key implications for policymakers looking to initiate green monetary policy for carbon abatement.
  • Publication
    Efficacy of Different Routes of Formalin-Killed Vaccine Administration on Immunity and Disease Resistance of Nile Tilapia (Oreochromis niloticus) Challenged with Streptococcus agalactiae
    ( 2022)
    Nguyen Vu Linh , Le Thanh Dien , Ha Thanh Dong , Nuttapon Khongdee, Seyed Hossein Hoseinifar, Mohamed Saiyad Musthafa, Mahmoud A. O. Dawood, Hien Van Doan
    Vaccines prepared from formalin-killed Streptococcus agalactiae were administered to Nile tilapia (Oreochromis niloticus) via three different routes: immersion in a water-based vaccine, injection with an oil-based vaccine, and as a water-based oral vaccine. All vaccination treatments increased lysozyme and peroxidase activity in skin mucus of Nile tilapia by 1.2- to 1.5-fold compared to their activities in unvaccinated control fish. Likewise, alternative complement, phagocytosis, and respiratory burst activities in the blood serum of the vaccinated fish were 1.2- to 1.5-times higher than in the unvaccinated fish. In addition, the expression transcripts of interleukin-1 (IL-1), interleukin-8 (IL-8), and lipopolysaccharide-binding protein (LBP) were 2.3- to 2.9-fold higher in the vaccinated fish compared to those in the unvaccinated control. The unvaccinated fish challenged with Streptococcus agalactiae had a survival rate of 25% compared to a survival rate of 78–85% for the vaccinated fish. The differences between the unvaccinated and vaccinated fish were all statistically significant, but there was no significant difference in any of the indicators of immunity between the three vaccinated groups. Collectively, these results confirm that vaccination with formalin-killed Streptococcus agalactiae significantly improved the resistance of Nile tilapia to infection by the pathogen. Overall, the efficacy of oral administration of the vaccine was comparable to that of vaccine administered via injection, indicating that oral vaccination is a viable cost-effective alternative to administering vaccines by injection.
  • Publication
    The role of economic conditions and sustainable rural development on the sustainability of tourism development: evidence from China
    ( 2022)
    Lam Minh Trung, Chenlei Xue, Yu‑Te Tu, Mohammed Ananzeh, Ahmad Ibrahim Aljumah, Thanh Quang Ngo
    At present, tourism is counted among those industries which have gained global attention due to rapid growth. Hence, a constant diversification in terms of destination is needed in tourism development. The recent trends of industry highlight the demand of alternative tourism types, among which nature-related tourism appears to be an emerging concept. In this regard, the present article investigates the impact of economic conditions and sustainable rural development on the sustainability of tourism development in China. The current research has gathered secondary data from the World Bank from 1981 to 2020. The quartile autoregressive distributed lag model has been applied to test the association between the variables. The results revealed that GDP, inflation, FDI, exchange rate, energy use, gross savings, and sustainable rural development have a significant and positive association with the sustainability of tourism development in China. Findings offer managerial implications recommending the local government to focus on the sustainability of rural development and economic conditions that may lead to the implementation of tourism-related development projects. This study also guides the policymakers in establishing policies related to tourism development using different economic conditions and sustainable rural development
  • Publication
    Fungi fabrication, characterization, and anticancer activity of silver nanoparticles using metals resistant Aspergillus niger
    ( 2022)
    Nguyen Thuy Lan Chi, Geetha Royapuram Veeraragavan, Kathirvel Brindhadevi, Arunachalam Chinnathambi, Saleh H. Salmen, Sulaiman Ali Alharbi, Ramakrishnan Krishnan, Arivalagan Pugazhendhi
    ings) metal-tolerant Aspergillus niger biomass filtrate and the anticancer potential of synthesized silver nanoparticles (AgNPs) tested with a Human Cervical cancer cell line (HeLa cells: Henrietta Lacks cells). The nitrate reduction test demonstrated that A. niger has the ability to reduce nitrate, and filtrate derived from A. niger biomass efficiently fabricated AgNPs from AgNO3, as demonstrated by a visible color change from pale greenish to brownish. The UV–visible spectroscopy analysis revealed an absorbance peak at 435 nm, which corresponded to the AgNPs. These AgNPs have been capped and stabilized with several functional groups related to various bioactive molecules such as aldehyde, benzene rings, aldehydic, amines, alcohols, and carbonyl stretch protein molecules. Fourier-Transform Infrared Spectroscopy (FTIR) analysis confirmed the capping and stabilizing chemical bonding pattern. Scanning Electron Microscopy (SEM) revealed that the synthesized AgNPs were spherical, with an average size of 21.38 nm. This bio-fabricated AgNPs has in-vitro anticancer potential when tested against the HeLa cell line due to its potential size and shape. At 100 g mL􀀀 1 concentrations of this biofabricated AgNPs, the anticancer activity percentage was found to be 70.2%, and the IC50 value was found to be 66.32 g m􀀀 1. These findings demonstrated that the metal-tolerant A. niger cell filtrate could produce AgNPs with anticancer potential.
  • Publication
    A viable bioremediation strategy for treating paper and pulp industry effluents and assessing the prospect of resulted bacterial biomass as single cell protein (SCP) using indigenous bacterial species
    ( 2022)
    Jutamas Khumchai, Anupong Wongchai, Ruangwong On-uma, Amal Sabour, Maha Alshiekheid, Mathiyazhagan Narayanan, Indira Karuppusamy, Arivalagan Pugazhendhi, Kathirvel Brindhadevi, Nguyen Thuy Lan Chi
    Aim of this research was to treat the organics enriched Paper and Pulp Industry (PPI) effluents using multi-metal tolerant predominant indigenous bacterial species. In addition, assessing the potential of treated bacterial biomass as a single cell protein (SCP). The multi-metal tolerant Streptomyces tuirus OS1 was enumerated from the Paper and Pulp Industry (PPI) effluents was identified through standard molecular characterization. S. tuirus OS1 proficiently ameliorated organic contaminants in PPI effluent in the in study at 35 ◦C, 45 ◦C, and 25 ◦C. Fortunately, the S. tuirus OS1 considerably increased the dissolved oxygen level in treated PPI effluent in 30 days of bioremediation process. Interestingly, at 35 ◦C of bioremediation process the S. tuirus OS1 demonstrated increased dried biomass (7.1 g L􀀀 1) with the total crude protein (SCP) as 5.3 g L􀀀 1 (78.79%) in 30 days of bioremediation process. These findings suggest that S. tuirus OS1 is capable of reducing organic pollutants in PPI effluents and producing biomass with enriched protein content.
  • Publication
    Role of soluble nano-catalyst and blends for improved combustion performance and reduced greenhouse gas emissions in internal combustion engines
    ( 2022)
    Xiumei Zhang, Nguyen Thuy Lan Chi, Changlei Xia, Amany Salah Khalifa, Kathirvel Brindhadevi
    Biofuels were getting an enormous attention to be used as fuel for diesel engines. This paper examines the effect of addition of nanoparticles in biofuel on diesel engines. The biofuel used for conducting tests was canola oil. Corn oil was mixed with titanium dioxide (TiO2) at different proportions as 25 ppm, 50 ppm, 75 ppm and 100 ppm. These nanoparticles mixed with biofuel and diesel. The nanoparticles were dispersed with biodiesel at the concentration of B10T25 (10% cornoil + 90% diesel + TiO225), B10T50, B10T75, B10T100, B20T25, B20T50, B20T75, and B20T100 and plain biodiesel are B10 and B20. All tests were carried at different speeds 1800 rpm, 2000 rpm, 2200 rpm, 2400 rpm, 2600 rpm and 2800 rpm. Performance and emission characteristics were estimated for all fuel blends. Results were compared to each other to characterize the fuel blend quality. The addition of titania with biofuel increased the performance qualities such as brake thermal efficiency (BTE), exhaust gas temperature (EGT), Torque and Power. Further this combination reduced the Greenhouse gas emissions such as CO, CO2, and UHC. The specific fuel consumption (SFC) was also reduced and proved to be the better alternative to existing fossil fuel. However, the emission of NOx was increased.
  • Publication
    Synthesis of copper nanoparticles from the aqueous extract of Cynodon dactylon and evaluation of its antimicrobial and photocatalytic properties
    ( 2022)
    Lumsangkul Chompunut, Tapingkae Wanaporn, Wongchai Anupong, Mathiyazhagan Narayanan, Maha Alshiekheid, Amal Sabour, Indira Karuppusamy, Nguyen Thuy Lan Chi, Rajasree Shanmuganathan
    The copper nanoparticles (CuNPs) synthesizing potential of Cynodon dactylon aqueous leaf extract and their antibacterial as well as dye degradation potentials were investigated. The synthesized CuNPs was initially characterized by gradual colour change from dark brown to blue in colour and then found absorbance peak at 469 nm. Furthermore, the SEM and DLS analyses showed that biosynthesized CuNPs were spherical in shaped and size ranging from 120 to 129 nm. The FTIR spectrum confirmed the presence of flavonoids, alkaloids, terpenoids, and phenols, which involved in the reduction, capping, and stabilization of CuNPs. This green synthesized CuNPs also demonstrated remarkable antibacterial activity against the bacterial pathogens such as Escherichia coli, Bacillus subtilis and Staphylococcus aureus and Klebsiella pneumoniae. This green synthesized CuNPs exhibited considerable dye degrading potential in the following order as methyl organge > methyl red > Erichrome black T dyes in the presence of sunlight through photocatalytic degradation process. These results conclude that C. dactylon aqueous leaf extract mediated nanoparticles possess remarkable antibacterial and dye degrading potential.
  • Publication
    Machine learning-based real-time daylight analysis in buildings
    ( 2022)
    Luan Le-Thanh
    ;
    Ha Nguyen-Thi-Viet
    ;
    Jaehong Lee
    ;
    H. Nguyen-Xuan
    Daylight analysis is essential in building design to ensure indoor environment quality, including health and thermal comfort vis-à-vis energy. It is a repeating and time-consuming process of design options. Several studies conducted machine learning models to accurately predict daylight performance in particular design situations. Therefore, developing an AI-based real-time daylight analysis platform becomes more promising. However, buildings can be designed with arbitrary shapes, creating a real challenge for the AI to recognize any building layout. From that perspective, the idea of finding the design variables that characterize all the building layouts becomes the key solution. To unlock this challenge, we promote a novel method of creating design variables and building a machine learning model that can efficiently forecast daylight performance with different building layouts. The daylight metric was Useful Daylight Illuminance with four ranges, and the case studies were assumed medium-sized buildings located in Ho Chi Minh City, Vietnam. All the data for training and predicting were created by the simulation DIVA tool. Obtained results showed the excellent performance of the proposed approach, which brings more promising in developing a data-driven machine learning platform for real-time daylight validation. Moreover, the present framework can adapt to any specific machine learning model or daylight simulation tool and daylight metrics.