The reproduction potentials of four entomopathogenic nematode strains related to cost-effective production for biological control

Chau Nguyen N.,Anh Le T.,Vu Nguyen H.,Phuc Hoang K. 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.2

Bioassays to evaluate the mortality, virulence and reproduction potentials of four indigenous EPN strains, SPQ16, S-BM12, H-KT3987 and H-CB3452 on insect larvae of mealworm (Tenebrio molitor) and greater wax moth (Galleria mellonella) revealed the highest mortality rates of two insect larvae at the highest inoculation dose of 100 IJs to range from 89 to 100 percent and 94.3–100 percent at 48 h after inoculation, respectively. Virulence was high for all nematode strains, with LC 50 values between 29.6 and 47.3 IJs/insect host. The highest IJ yields were different between nematode strains and insect host, from 66.8 × 10 3 IJs (S-PQ16) to 118.6 × 10 3 IJs (HKT3987) on T. molitor, and from 54.2 × 10 3 IJs (S-BM12) to 163.3 × 10 3 IJs (H-KT3987) on G. mellonella. The culturing cost in terms of food expenditure for rearing insect larvae varied between insect larvae and nematode strains, from 6.76 to 26.63 USD per billion IJs for nematode strains cultured on T. molitor larvae and from 3.54 to 7.81 USD per billion IJs for nematode strains cultured on G. mellonella larvae. The full cost for a nematode product of 2.5 × 10 9 IJs per hectare, produced through in vivo mass culturing, of the most efficient nematode strain, H-KT3987, was 191.3 USD, slightly cheaper than 199.4 USD for the same nematode product produced through in vitro mass culturing.

Effect of Co substitution on ferrimagnetic Heusler compound Mn3Ga

Nguyen Quynh Anh T.,Ho Thi H.,Jung Myung-Hwa,Rhim Sonny H. 한국물리학회 2023 Current Applied Physics Vol.49 No.-

Effect of Co substitution on Mn3Ga is investigated using first-principles study for structural and magnetic properties. Without Co, ferrimagnetic Heusler compound Mn3Ga is in tetragonal phase. With Co substitution, depending on Co concentration (x), Mn3Ga prefers tetragonal (cubic) phase when x ≤ 0.5 ( x ≥ 0.5). Ferrimagnetism is robust regardless of x in both phases. While magnetic moments of two Mn do not vary significantly with x, magnetic moments of Co in two phases exhibit different behaviors, leading to distinct features in absolute value of total magnetic moment (|Mtot |). When x ≤ 0.5, in tetragonal phase, magnetic moment of Co is vanishingly small, resulting in a decrease of |Mtot | with x. In contrast, when x ≥ 0.5, in cubic phase, magnetic moment of Co is roughly 1μB, which is responsible for the increase of |Mtot |. Electronic structure is analyzed with partial density of states for various x. To elucidate the counterintuitively small Co moment, the magnetic exchange interaction is investigated, where exchange coefficient between Co and Mn(II) in x ≤ 0.5 is much smaller than that in x ≥ 0.5.

Low-blinking SERS substrate for switchable detection of kanamycin

Nguyen, Anh H.,Ma, Xingyi,Park, Hyun Gyu,Sim, Sang Jun Elsevier 2019 Sensors and actuators. B, Chemical Vol.282 No.-

<P><B>Abstract</B></P> <P>Metallic plasmonic nanoparticles generate surface-enhanced Raman Scattering (SERS) for wide sensing applications of biomolecules, gas and environmental contaminants. However, the metallic materials cause high thermal radiation during laser excitation in the opto-microfluidic systems and give rise to temporal intensity fluctuations, which is called blinking effects in SERS spectra. This work developed nanocomposite consisting of graphene oxide (GO) and gold nanoparticles (AuNPs) with high thermal stability and low thermal radiation, which provided plasmonic resonance while reduced blinking effect for SERS-based sensing in the microfluidic detection system. The system was applied to detect kanamycin in drinking water, orange juice, and milk by using Texas Red-dye conjugated Beacon aptamer, where the aptamer was designed to be specific and switchable in kanamycin recognition. The sensor was reusable, and its limit of detection was 0.75 nM in a linear range of 1 nM to 100 nM. The microfluidic SERS detection system can be potentially used for sensitive and reliable assays of small molecules.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanocomposite of graphene oxide and gold nanoparticles was developed. </LI> <LI> The nanocomposite was substrate of a SERS microfluidic biosensor. </LI> <LI> Blinking effects in SERS was obviously reduced. </LI> <LI> The biosensor was applied to detect kanamycin in drinking water (LOD, 0.75 nM). </LI> <LI> The aptamer of the sensor is specific and switchable. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Nanoplasmonic probes of RNA folding and assembly during pre-mRNA splicing

Nguyen, Anh H.,Lee, Jong Uk,Sim, Sang Jun The Royal Society of Chemistry 2016 Nanoscale Vol.8 No.8

<P>RNA splicing plays important roles in transcriptome and proteome diversity. Herein, we describe the use of a nanoplasmonic system that unveils RNA folding and assembly during pre-mRNA splicing wherein the quantification of mRNA splice variants is not taken into account. With a couple of SERS-probes and plasmonic probes binding at the boundary sites of exon-2/intron-2 and intron-2/exon-3 of the pre-mature RNA of the beta-globin gene, the splicing process brings the probes into the plasmonic bands. For plasmonic probes, a plasmon shift increase of similar to 29 nm, corresponding to intron removal and exon-2 and exon-3 connection to form the mRNA molecule, is measured by plasmonic coupling. The increased scattering intensity and surface-enhanced Raman scattering (SERS) fingerprinting reveal the clear dynamics of pre-mRNA splicing. Moreover, a time-resolved experiment of individual RNA molecules exhibited a successful splicing and an inhibited splicing event by 33 mu M biflavonoid isoginkgetin, a general inhibitor of RNA splicing. The results suggest that the RNA splicing is successfully monitored with the nanoplasmonic system. Thus, this platform can be useful for studying RNA nanotechnology, biomolecular folding, alternative splicing, and maturation of microRNA.</P>

Gaussian Decomposition Method in Designing a Freeform Lens for an LED Fishing/Working Lamp

Anh Q. D. Nguyen,Vinh H. Nguyen,Hsiao-Yi Lee 한국광학회 2017 Current Optics and Photonics Vol.1 No.3

In this paper we propose a freeform secondary lens for an LED fishing/working lamp (LFWL). Thisinnovative LED lamp is used to replace the traditional HID fishing lamp, to satisfy the lighting demandsof fishing and the on-board activities on fishing boats. To realize the freeform lens’s geometry, Gaussiandecomposition is involved in our optics-design process for approaching the targeted light intensity distributioncurve (LIDC) of the LFWL lens. The simulated results show that the illumination on the deck, on thesea’s surface, and underwater shows only small differences between LED fishing/working lamps and HIDfishing lamps. Meanwhile, a lighting efficiency of 91% with just one third of the power consumption canbe achieved, when the proposed LED fishing/working lamps are used instead of HID fishing lamps.

Effect of Red-emitting Sr2.41F2.59B20.03O74.8:Eu0.12,Sm0.048 Phosphor on Color Rendering Index and Luminous Efficacy of White LEDs

Anh Q. D. Nguyen,Vinh H. Nguyen,Hsiao-Yi Lee 한국광학회 2017 Current Optics and Photonics Vol.1 No.2

Color rendering index (CRI) and luminous efficacy (LE) are two key performance factors of white LEDs(WLED). While most recent works in optics focus on methodology to improve these factors, little attentionhas been dedicated to chemical composition of materials. This paper studies the effect of Sr2.41F2.59B20.03O74.8:Eu0.12,Sm0.048 phosphor (SrSm), in terms of concentration and particle size on CRI and LE of 8500K -WLEDs. Importantly, the molar mass of the componential ions in SrSm are calculated to shed lighton the connection between the chemical composition of the material of interest and the performance ofWLEDs. Results show that CRI can be improved to a value of around 86 by boosting red-light componentsin WLEDs, for all 3 major configurations: conformal, in-cup, and remote phosphor. CRI value tends todecrease with larger size of particles, while LE value goes in the reverse direction. On the other hand,both CRI and LE appear to be reduced at higher concentration of SrSm. This light attenuation is analyzedby using the Lambert-Beer law and Mie-scattering theory.

NURBS-based postbuckling analysis of functionally graded carbon nanotube-reinforced composite shells

Nguyen, Tan N.,Thai, Chien H.,Luu, Anh-Tuan,Nguyen-Xuan, H.,Lee, Jaehong North-Holland Pub. Co 2019 Computer methods in applied mechanics and engineer Vol.347 No.-

<P><B>Abstract</B></P> <P>An investigation into the postbuckling and geometrically nonlinear behaviors of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) shells is carried out in this study. The discrete nonlinear equation system is established based on non-uniform rational B-Spline (NURBS) basis functions and the first-order shear deformation shell theory (FSDT). The nonlinearity of shells is formed in the Total Lagrangian approach considering the von Karman assumption. The incremental solutions are obtained by using a modified Riks method. In the present formulation, the rule of mixture is used to estimate the effective material properties of FG-CNTRC shells. Effects of CNTs distribution, volume fraction and CNTs orientation on the postbuckling behavior of FG-CNTRC shells are particularly investigated. Exact geometries of shells are modeled by using NURBS interpolation. Several verifications are given to show the high reliability of the proposed formulation. Especially, some complex postbuckling curves of FG-CNTRC panels and cylinders are first provided that could be useful for future references.</P> <P><B>Highlights</B></P> <P> <UL> <LI> NURBS-based postbuckling analysis of functionally graded carbon nanotube-reinforced composite shells is performed in this paper. </LI> <LI> The discrete nonlinear equation system is established based on non-uniform rational B-Spline (NURBS) basis functions and the first-order shear deformation shell theory (FSDT). </LI> <LI> The nonlinearity of shells is formed in the Total Lagrangian approach considering the von Karman assumption. </LI> <LI> Effects of CNTs distribution, volume fraction and CNTs orientation on the postbuckling behavior of FG-CNTRC shells are particularly investigated. </LI> <LI> Some complex postbuckling curves of FG-CNTRC panels and cylinders are first provided that could be useful for future references. </LI> </UL> </P>

The utilization of BIM-IoT-GIS integrated digital twin technology in the context of modular construction for facility management

Nguyen, D. H. N. Truong(응우옌 당 호앙 낫 쯔엉),Nguyen, Ho Anh Thu(원호안트),Chon, Yujin(천유진),Kim, Woo-Jae(김우재),Ahn, Yong-han(안용한) 대한건축학회 2024 대한건축학회 학술발표대회 논문집 Vol.44 No.1

Inverse Magnetoresistance in the Simple Spin Valve System Fe<SUB>1-x</SUB>Cr<SUB>x</SUB>/Cu/Co

Ngoc Anh T. Nguyen,Hoang Yen T. Nguyen,H. Yil,S. J. Joo,K. H. Shin 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Tunability of Structure and Magnetism in Heusler Mn<SUB>3-x</SUB>Co<SUB>x</SUB>Ga (0 ≤ x ≤ 1)

Quynh Anh Thi Nguyen,Thi H. Ho,S. C. Hong,S. H. Rhim 한국자기학회 2021 한국자기학회 학술연구발표회 논문개요집 Vol.31 No.2

Mn₃Ga has drawn interest in spintronics for potential applications due to large perpendicular magnetic anisotropy, high Curie temperature (~760 K), and low magnetization. Motivated by previous studies on tunability of magnetism through transition metal substitutions in Mn₃Ga, we investigate magnetic and structural properties of Mn₃Ga upon Co substitution using first-principles calculations. In the absence of Co, Mn₃Ga is in tetragonal phase. With Co, both tetragonal and cubic phases occur. x ≤ 0.5, tetragonal phase is preferred, while x > 0.5, cubic one is favored. Co magnetic moment in two phases exhibit different magnetic behaviors. In tetragonal phase, unlike other Co compounds, Co magnetic moment nearly vanishes. On the other hand, in cubic phase, it retains a usual moment at about 1 μB. Nearly vanishing Co magnetic moment in tetragonal structure is elucidated phenomenologically by the magnetic exchange coefficient, where coupling between Co and Mn is much smaller than cubic one. Furthermore, anomalous Hall conductivities (AHC) are investigated for x = 0, 0.5, and 1. The magnitude of AHC is about 100~500 S/cm, where the sign change occurs at 0.5 < x < 1.