Anti-inflammatory Activities of Wheat grain and Wheatgrass extracts of Korean origin in LPS-Stimulated RAW 264.7 macrophages

Laura Amaya Quiroz,Soo Min Baek,Mi Jeong Kim,In Hye Jung,Bok Kyung Han,Young Jun Kim 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Wheatgrass is being studied because it is considered a better source of various flavonoids, phytochemicals. The Korean origin cultivar of Keumgang and Arihuk have been known for containing various functional ingredients at relatively higher level compared to imported wheat. However, the anti-inflammatory activity has not yet been clearly elucidated. Therefore, the focus of this study was to determine the anti-inflammatory effects of ethanol extracts of whole wheat and wheat sprouts of Keumgang and Ariheuk. Treatment with ethanol extracts of whole wheat grain and wheat sprouts showed low cytotoxicity and inhibition of nitric oxide (NO) production. In particular, NO production was inhibited at a concentration-dependent manner when ethanol extracts of the whole wheat grain extracts were treated. As well, it was confirmed that both the whole wheat grain and wheat sprout extracts showed the inhibitory effects on the expression of inflammatory cytokines (iNOS, CoX2, IL-6). Therefore, taken the above results together, it was believed that the ethanol extracts of whole wheat and wheat sprouts of Keumgang and Ariheuk can be developed as functional ingredients with anti-inflammatory effects.

RANS Simulation of Wind Loading on Vaulted Canopy Roofs

Edmundo Amaya-Gallardo,Adrián Pozos-Estrada,Roberto Gómez 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.12

The use of isolated vaulted canopy roofs (VCR) for schools, emerging shelters, sports and recreational centers, among others, is quite popular worldwide. However, the design of such structures to resist wind effects is usually a problem due to the scarce technical information available in the literature. As an alternative resource, in the present research, wind effects on this type of structures immersed in the atmospheric boundary layer (ABL) are studied numerically by using the 3D Reynolds averaged Navier Stokes (RANS) approach considering different aspect ratios and wind directions. Since wind tunnel testing information for these structures is limited, experimental results of a Gabled Canopy Roof (GCR) as well as some experimental results for VCR are used as a validation source for the numerical models. Based on this validation, the simulation results of the mean wind loads of VCR appear to be reasonably good. The numerical results are used to study the mean net-pressure coefficients (CPN) over the VCR models and to establish the theoretical bases for coding them. It was found that the CPN are very sensitive to the VCR curvature and wind direction (90°, 75°, and 60°), and to a less extent to the plan and elevation geometric ratios. Further, it was also found that the use of GCR CPN for the design of VCR, as is usually done in professional practice, could lead to important differences in the magnitude of pressure coefficients and pressure distribution regarding actual VCR CPN and its distribution. A detailed analysis of the CPN for VCRs is presented.

EFFECT OF SOLUBLE ADDITIVES, BORIC ACID (H_3BO_3) AND SALT (NaCl), IN POOL BOILING HEAT TRANSFER

곽상묵,MIGUEL AMAYA,HYEJIN MOON,SEUNG M. YOU 한국원자력학회 2011 Nuclear Engineering and Technology Vol.43 No.3

The effects on pool boiling heat transfer of aqueous solutions of boric acid (H_3BO_3) and sodium chloride (NaCl) as working fluids have been studied. Borated and NaCl water were prepared by dissolving 0.5~5% volume concentration of boric acid and NaCl in distilled-deionized water. The pool boiling tests were conducted using 1 x 1 cm2 flat heaters at 1 atm. The critical heat flux (CHF) dramatically increased compared to boiling pure water. At the end of boiling tests it was observed that particles of boric acid and NaCl had deposited and formed a coating on the heater surface. The CHF enhancement and surface modification during boiling tests were very similar to those obtained from boiling with nanofluids. Additional experiments were carried out to investigate the reliability of the additives deposition in pure water. The boric acid and NaCl coatings disappeared after repeated boiling tests on the same surface due to the soluble nature of the coatings, thus CHF enhancement no longer existed. These results demonstrate that not only insoluble nanoparticles but also soluble salts can be deposited during boiling process and the deposited layer is solely responsible for significant CHF enhancement.

EXPERIMENTAL POOL BOILING HEAT TRANSFER STUDY OF THE NANOPOROUS COATING IN VARIOUS FLUIDS

곽상묵,MIGUEL AMAYA,SEUNG M. YOU 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.1

An experimental pool boiling study was conducted using plain and nanoporous coated heater surfaces immersed in various working fluids: water, ethanol and HFE-7100. Pool boiling tests were performed on flat 1 cm × 1 cm heaters. Unlike in water, the critical heat flux (CHF) enhancement of the nanoporous coating seems to be less or marginal in ethanol and HFE-7100 at 1 atm. The reduced effect of the nanoporous coating in ethanol and HFE-7100 is believed to be due to the highly wetting nature of these fluids since no obvious difference in wettability is observed between nanoporous coated and uncoated surfaces through apparent contact angle measurement. Moreover, pressure effects were also investigated for the fluids mentioned above. For the nanoporous coated surface, CHF enhancement of the nanoporous coating appeared to be dependent on the test pressure, showing greater CHF enhancement at lower pressure. It is believed that this pressure dependent CHF enhancement behavior could be closely related to the bubble departure diameter. As pressure lowers, the departure bubble size increases and this allows the nanoporous coating to become more influential, even for the highly wetting fluids, in delaying local dry-out, which in turn results in increasing CHF enhancement.

A REVIEW OF ENHANCEMENT OF BOILING HEAT TRANSFER THROUGH NANOFLUIDS AND NANOPARTICLE COATINGS

SEUNG M. YOU,MIGUEL AMAYA,곽상묵 대한설비공학회 2010 International Journal Of Air-Conditioning and Refr Vol.18 No.4

This review traces the development of nanofluid pool boiling from its beginning (1984) to the present through a sampling of studies that have interested the authors and which have led to the latest findings at the University of Texas at Arlington (UTA). The studies of thermophysical properties of nanofluids are briefly covered. Several works in the last 7 years are highlighted to illustrate the modes of nanofluid pool boiling testing, the variability of nanofluid boiling heat transfer (BHT), and the postulations of causes of this behavior. Starting in 2006, the wettability increase in the nanoparticle coating, generated during the nanofluid pool boiling, is recognized as the source of critical heat flux (CHF) enhancement through its effect on the dynamics of hot spots and departing bubbles. The reasons for the observed contradictory BHT behavior are not yet fully clear, but recently at UTA, nanofluid boiling heat transfer has shown to be transient due to the dynamic nature of the formation of the nanoparticle coating. Also at UTA, the mechanism of nanoparticle deposition on the heated surface has been further confirmed. Thus, nanofluid boiling has led back to heat transfer enhancement through surface modification in nanoscale. These developments from 2006 are covered in more detail.

Pre-emphasis, Windowing and Spectral Estimation of Silent Speech Signals Using Embedded Systems

Leonardo A. Góngora,Dario Amaya,Olga L. Ramos 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.10

The feature extraction process is the fundamental stage in the development of speech processing systems. In this paper is described the methodology and implementation of an embedded algorithm for extracting characteristic information from silent speech signals. The classical approach based on frequency representations of the signals is followed as methodology for this work. First, the acquisition stage of the silent speech signals is performed using a Non-Audible Murmur microphone and the STM32F4Discovery evaluation board. Then, the digitalized signal is filtered, segmented and normalized using the pre-emphasis and windowing steps. The magnitude spectrogram is calculated from the pre-processed signal using the Fast Fourier Transform (FFT), to finally estimate characteristic data from de silent speech signal. As result of this process, the signal characteristic parameters, defined in the frequency domain are obtained and used as elements at later stages of pattern recognition, in order to build systems of Automatic Speech Recognition (ASR), Speech Coding, Speaker Recognition, among other applications.

Virtual Laboratory of Bottling Process with Temperature Control in an Autoclave

Jefry Anderson Mora,Dario Amaya 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.9

Technological advances in the area of virtual laboratories in recent years, have made possible the implementation of industrial processes in virtual environments for different purposes, such as monitoring and control of these processes, and as a didactic aid in the education field at professional level. This development offers the capability to navigate and control a graphical environment of a bottling process in the brewery industry. As well as being accessible from any virtual platform with internet access.

A REVIEW OF ENHANCEMENT OF BOILING HEAT TRANSFER THROUGH NANOFLUIDS AND NANOPARTICLE COATINGS

You, Seung-M.,Amaya, Miguel,Kwark, Sang-M. The Society of Air-Conditioning and Refrigerating 2010 International Journal Of Air-Conditioning and Refr Vol.18 No.4

This review traces the development of nanofluid pool boiling from its beginning (1984) to the present through a sampling of studies that have interested the authors and which have led to the latest findings at the University of Texas at Arlington (UTA). The studies of thermophysical properties of nanofluids are briefly covered. Several works in the last 7 years are highlighted to illustrate the modes of nanofluid pool boiling testing, the variability of nanofluid boiling heat transfer (BHT), and the postulations of causes of this behavior. Starting in 2006, the wettability increase in the nanoparticle coating, generated during the nanofluid pool boiling, is recognized as the source of critical heat flux (CHF) enhancement through its effect on the dynamics of hot spots and departing bubbles. The reasons for the observed contradictory BHT behavior are not yet fully clear, but recently at UTA, nanofluid boiling heat transfer has shown to be transient due to the dynamic nature of the formation of the nanoparticle coating. Also at UTA, the mechanism of nanoparticle deposition on the heated surface has been further confirmed. Thus, nanofluid boiling has led back to heat transfer enhancement through surface modification in nanoscale. These developments from 2006 are covered in more detail.

EFFECT OF SOLUBLE ADDITIVES, BORIC ACID (H₃BO₃) AND SALT (NaCl), IN POOL BOILING HEAT TRANSFER

Kwark, Sang-M.,Amaya, Miguel,Moon, Hye-Jin,You, Seung-M. Korean Nuclear Society 2011 Nuclear Engineering and Technology Vol.43 No.3

The effects on pool boiling heat transfer of aqueous solutions of boric acid ($H_3BO_3$) and sodium chloride (NaCl) as working fluids have been studied. Borated and NaCl water were prepared by dissolving 0.5~5% volume concentration of boric acid and NaCl in distilled-deionized water. The pool boiling tests were conducted using $1{\times}1\;cm^2$ flat heaters at 1 atm. The critical heat flux (CHF) dramatically increased compared to boiling pure water. At the end of boiling tests it was observed that particles of boric acid and NaCl had deposited and formed a coating on the heater surface. The CHF enhancement and surface modification during boiling tests were very similar to those obtained from boiling with nanofluids. Additional experiments were carried out to investigate the reliability of the additives deposition in pure water. The boric acid and NaCl coatings disappeared after repeated boiling tests on the same surface due to the soluble nature of the coatings, thus CHF enhancement no longer existed. These results demonstrate that not only insoluble nanoparticles but also soluble salts can be deposited during boiling process and the deposited layer is solely responsible for significant CHF enhancement.

Comparative antioxidant activity of Korean wheat cultivar; Keumgang and Ariheuk

Soo Min Baek,Laura Amaya,Mi Jeong Kim,In Hye Jung,Bok Kyung Han,Young Jun Kim 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

Colored grain is known to have relatively higher nutritional value because it is rich in anthocyanins and polyphenol compounds. In this study, total phenolic content, antioxidant activity, and cytoprotective against oxidative damage were confirmed for extract of grain and sprout from Keumgang, white wheat, and Ariheuk, colored wheat. Total phenolic content was higher in sprout than in grain, and highest in hot water extracts of Keumgang and Ariheuk sprout. Antioxidant activity was confirmed by measuring ABTS and DPPH radical scavenging ability. As a result, extracts of sprout had higher antioxidant efficacy than extracts of grain. When the cytoprotective effect of extracts of Keumgang and Ariheuk wheat were confirmed in oxidative stress-induced Caco-2 cells, the sprout extract had a higher cytoprotective effect compared to the grain extract. Particularly, Ariheuk sprout had highest effect when extracted with 30% EtOH. The above results suggest that wheat sprout extracts of Keumgang and Ariheuk could be considered as a source of antioxidants and cytoprotective agent.