Numerical study on combined thermal radiation and magnetic field effects on entropy generation in unsteady fluid flow past an inclined cylinder

Zachariah Mbugua Mburu,Sabyasachi Mondal,Precious Sibanda 한국CDE학회 2021 Journal of computational design and engineering Vol.8 No.1

This study reports on combined thermal radiation, chemical reaction, and magnetic field effects on entropy generation in an unsteady nanofluid flow past an inclined cylinder using the Buongiorno model. We consider the impact of viscous dissipation, velocity slip conditions, thermal slip conditions, and the Brownian motion. The transport equations governing the flow are solved using an overlapping grid spectral collocation method. The results indicate that entropy generation is suppressed significantly by thermal radiation and chemical reaction parameters but enhanced with the magnetic field, viscous dissipation, the Brinkman number, and the Reynolds number. Also, fluid flow variables are affected by the thermophoresis parameter, the angle of cylinder inclination, and the Richardson number. We present the findings of the skin friction coefficient, the Nusselt number, and the Sherwood number. The model is applicable in fields such as the petroleum industry, building industries, and medicine.

The acceptance of nuclear energy as an alternative source of energy among Generation Z in the Philippines: An extended theory of planned behavior approach

Belmonte Zachariah John A.,Prasetyo Yogi Tri,Benito Omar Paolo,Liao Jui-Hao,Susanto Krisna Chandra,Young Michael Nayat,Persada Satria Fadil,Nadlifatin Reny 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.8

Nuclear Power Plants (NPP) are widely utilized around the globe from different base forms as it is one of the most dependable renewable resources that technological advancements have offered. However, different perceptions of the usage of NPPs emerged from different generations. The purpose of this study was to investigate the acceptance of nuclear energy as an alternative source of energy among Generation Z in the Philippines by utilizing an extended Theory of Planned Behavior (TPB) approach. An online questionnaire which consisted of 31 items was distributed using a purposive sampling approach and 450 respondents of Generation Z voluntarily answered. Structural Equation Modeling (SEM) showed that the knowledge regarding NPP had significant effects on risk perception and benefit perception which subsequently led to subjective norms. In addition, perceived behavioral control and subjective norms had significant effects on behavioral intention which led to nuclear acceptance. Interestingly, the respondents perceived the benefit of NPP as slightly higher than the perceived risk. With these, it was clear that the commissioning Nuclear Power Plant must consider as an alternative source of electric energy in the Philippines. Moreover, this study is one of the first studies that investigated the acceptance of NPP among Generation Z. Lastly, the model could be a basis to strengthen the acceptance strategy of opening NPP among Generation Z, particularly in developing countries.

EWSR1 rearranged primary renal myoepithelial carcinoma: a diagnostic conundrum

Nilay Nishith,Zachariah Chowdhury 대한병리학회 2023 Journal of Pathology and Translational Medicine Vol.57 No.5

Primary renal myoepithelial carcinoma is an exceedingly rare neoplasm with an aggressive phenotype and Ewing sarcoma breakpoint region 1 (EWSR1) rearrangement in a small fraction of cases. In addition to its rarity, the diagnosis can be challenging for the pathologist due to morphologic heterogeneity, particularly on the biopsy specimen. At times, immunohistochemistry may be indecisive; therefore, molecular studies should be undertaken for clinching the diagnosis. We aim to illustrate a case of primary myoepithelial carcinoma of the kidney with EWSR1-rearrangement in a 67-year-old male patient who presented with right supraclavicular mass, which was clinically diagnosed as carcinoma of an unknown primary. An elaborate immunohistochemical work-up aided by fluorescent in-situ hybridization allowed us to reach a conclusive diagnosis. This unusual case report advocates that one should be aware of the histological mimickers and begin with broad differential diagnoses alongside sporadic ones and then narrow them down with appropriate ancillary studies.

Molecular Characterization of Vibrio cholerae Isolates from Cholera Outbreaks in North India

Joseph J. Kingston,Kuruvilla Zachariah,Urmil Tuteja,Sanjay Kumar,Harsh Vardhan Batra 한국미생물학회 2009 The journal of microbiology Vol.47 No.1

Vibrio cholerae isolates recovered from cholera outbreaks in Bhind district of Madhya Pradesh and Delhi, Northern India were characterized. The O1 serogroup isolates from Bhind outbreak were of Inaba serotype whereas both Ogawa and Inaba serotypes were recovered from Delhi. PCR analysis revealed that only O1 serogroup V. cholerae isolates carried the virulence-associated genes like ctxA, tcpA, ace, and zot. Molecular typing by repetitive sequence based ERIC, VCR1, and VC1 PCR’s revealed similar DNA profile for both Inaba and Ogawa serotypes. A discrete VC1-PCR band identified among the El Tor strains had greater similarity (>97%) to the V. cholerae genome sequence and therefore has the potential to be used as a marker for the identification of the V. cholerae strains. Non-O1 strains recovered from Bhind region differed among themselves as well as from that of the O1 isolates. All the O1 serogroup isolates possessed SXT element and were uniformly resistant to the antibiotics nalidixic acid, polymyxin-B, furazolidone, cloxacilin, trimethoprim-sulfamethaxazole, and vibriostatic agent O129. Inaba strains from both Delhi and Bhind differed from Ogawa strains by their resistance to streptomycin despite sharing similar DNA patterns in all the three rep-PCRs. Though Delhi and Bhind are separate geographical regions in Northern India, Inaba strains from both these places appear to be closely related owing to their similarity in antibiogram and genetic profile.

Metabolomic Analysis and Antioxidant Effect of Amla (Emblica officinalis) Extract in Preventing Oxidative Stress-Induced Red Cell Damage and Plasma Protein Alterations: An In Vitro Study

Rajaa Muthu Packirisamy,Zachariah Bobby,Sankar Panneerselvam,Smitha Mariam Koshy,Sajini Elizabeth Jacob 한국식품영양과학회 2018 Journal of medicinal food Vol.21 No.1

Amla (Emblica officinalis) has antidiabetic, hypolipidemic, anti-inflammatory, and antioxidant properties, but its effect on free radical induced red cell damage and membrane and plasma protein alterations has not been adequately addressed. The aim of the present study was to evaluate the antioxidant property of amla against oxidative stress induced red cell damage and plasma protein alterations. Red blood cells (RBCs) were preincubated with different concentrations of amla extract (50, 100, 150, and 200 μg/mL) and then treated with physiological (5 mM) and pathological (50 mM) concentrations of glucose for 24 h. In another in vitro study the plasma was pretreated with different concentrations of amla extract and then incubated with 2, 2′-Azo-Bis (2-methylpropionamidine) dihydrochloride (AAPH) for 2 h. After the incubation RBC-malondialdehyde (MDA), RBC-reduced glutathione (GSH), RBC indices, RBC morphometric study, plasma MDA, protein carbonylation, total protein, and albumin were estimated. The antioxidant property of amla was assessed by DPPH assay. RBC-MDA levels were significantly decreased and RBC-GSH levels were significantly increased with higher concentration of amla extract (150 and 200 μg/mL). Red cell count and its indices were improved with the increasing concentration of amla. In addition, at higher concentration, amla restored the RBC membrane integrity. The plasma in vitro study also showed that amla improved the plasma MDA, protein carbonylation, total protein, and albumin levels. Amla extract effectively protected the RBCs and plasma proteins from the reactive oxygen species induced oxidative damage. Liquid chromatography-mass spectrometry (LC-MS) analysis of the extract revealed the presence of gallic acid, quinic acid, and quercetin as the major constituents in addition to the other flavonoids.

Nanosecond laser induced energetic ion formation from a nanoparticle: The origin of ion detection loss in a single particle mass spectrometry

Oh, Yongsuk,Zahaf, Riyan,Zachariah, Michael R.,Lee, Donggeun Institute of Pure and Applied Physics 2014 Japanese Journal of Applied Physics Vol. No.

<P>Here we study the interaction of a nanosecond laser pulse with a nanoparticle to explore the mechanism of energetic ion formation and in particular the particle size dependence. Multiphoton ionization and the subsequent electron impact ionization accompanied by inverse Bremsstrahlung process are determined appropriate for generation of multiple charged ions. The Coulomb expansion of a positive ion cloud is then calculated with molecular dynamics simulations, resulting in temporal evolution of ions, a radial distribution of kinetic energy of ions, and size-dependency of the ion kinetic energy. A mass spectrum peak of ion simulated by the present model is found comparable to the experimental data. Alternatively, a direct measurement of kinetic energy is also explained by the model. (C) 2014 The Japan Society of Applied Physics</P>

단일입자 질량분석기를 이용한 서브마이크론 입자의 특성화 (I)

이동근,Michael R. Zachariah 대한기계학회 2005 大韓機械學會論文集B Vol.29 No.4

Density measurement of size selected multiwalled carbon nanotubes by mobility-mass characterization

Kim, S.H.,Mulholland, G.W.,Zachariah, M.R. Pergamon Press ; Elsevier Science Ltd 2009 Carbon Vol.47 No.5

We employ a combination of gas phase particle mobility and mass methods to make the first absolute density measurement of gas phase grown carbon nanotubes (CNTs). The approach combines a tandem differential mobility analyzer and aerosol particle mass analyzer in series to achieve two steps of electrical mobility classifications of the CNTs and one of mass classification. In the first mobility classification step a stream of monodisperse catalytic particles was produced by pulsed laser ablation. These mobility-classified catalysts seeded the aerosol growth of CNTs, where were directly passed to a second electrical mobility classification step which allows classification of the diameter-controlled CNTs in length. These diameter- and length-classified CNTs were finally introduced into the aerosol particle mass analyzer to measure their mass distribution. We found that the condensed phase density of CNTs was 1.74+/-0.16g/cm<SUP>3</SUP> for two different groups of CNTs with diameters of ∼15 and ∼22nm. This value is lower (about 3 sigma) than for graphite, and about 1 sigma lower than the average value for density measurements for carbon black.

Characterization of metal-bearing diesel nanoparticles using single-particle mass spectrometry

Lee, D.,Miller, A.,Kittelson, D.,Zachariah, M.R. Elsevier 2006 Journal of aerosol science Vol.37 No.1

<P><B>Abstract</B></P><P>Acute and chronic health effects have been associated with diesel particulate matter (DPM). Since both ultrafine particles and metals have been implicated in this correlation, we are conducting investigations to characterize the metal content of diesel nanoparticles. For this study, DPM was generated by a 1.5l engine and ferrocene was added to the fuel to raise the level of metal in the system. The exhaust particles were analyzed in real time using a recently developed single-particle mass spectrometer (SPMS) that has the capability of ablating each particle down to its elemental constituents, thereby yielding the relative mass of elements in each particle. Particle-size calibration of the instrument was achieved by correlating the SPMS signal intensity with measured DPM size. Using this approach, we present size- and composition-resolved elemental species distributions for both the nuclei mode and ultrafine portion of the accumulation mode of DPM. Results show that when the fuel is doped with ferrocene, iron-rich nanoparticles are formed and their number and size increase with level of doping. Larger iron-bearing particles are also formed, but it is observed that the metal to carbon ratios increase for smaller particle sizes. Hydrogen to carbon ratios were measured as a function of particle size, which allowed us to determine the relative amounts of organic carbon and elemental carbon in the particles and showed that the hydrogen to carbon ratios increase for smaller sized particles. The combined results are used to discuss the effects of metal doping level and engine load on particle nucleation and mechanisms of DPM formation.</P>

Understanding the Interaction of an Intense Laser Pulse with Nanoparticles: Application to the Quantification of Single Particle Mass Spectrometry

Zhou, L.,Park, K.,Milchberg, H. M.,Zachariah, M. R. Taylor Francis 2007 AEROSOL SCIENCE AND TECHNOLOGY Vol.41 No.9

<P> Understanding the characteristic behavior of ions produced from the interaction of a high energy laser pulse with nanoparticles is essential for quantitative determination of composition and size of nanoparticles from single particle mass spectrometry (SPMS). We employed a one-dimensional hydrodynamic model, where the laser field is coupled to the non-equilibrium time-dependent plasma hydrodynamics of the heated particles. We focus on regimes of laser width from 0.01 ns to 10 ns (532 nm wavelength, 100 mJ/pulse) and particle size (20-400 nm in diameter) most relevant to commonly used SPMS, and determine the properties of ions generated during the interaction with a strong laser pulse. We compare the simulation results with experiments conducted on aluminum nanoparticles. The laser-particle interaction is separated into a "soft heating" regime followed by a hydrodynamic expansion. Simulation results showed that the ablation/ionization is effectively complete well before the laser ever reaches its peak intensity. As the pulse width decreased for a given pulse energy, the kinetic energy of ions increased, suggesting that too short a pulse laser (i.e., high laser intensity) would be undesirable because higher energetic ions lead to lower detection efficiency in the SPMS. Results also show that for particle sizes in the range of 100 nm ∼ 400 nm, as particle size increased, the kinetic energy of ions produced from the particle increased with a power law relationship, consistent with experiment. Lastly our simulations indicated that ions from the surface of the particle are of higher energy, and therefore have lower detection efficiency.</P>