Effects of surface wettability on pool boiling of water using super-polished silicon surfaces

Mohammadi, Niloofar,Fadda, Dani,Choi, Chang Kyoung,Lee, Jungho,You, S.M. Elsevier Science B.V., Amsterdam. 2018 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.127 No.2

Digital application of bioreactor monitoring

Hye Ji Lee,Sarah Fadda,Lorena F.S. Souza,Jong Min Lee 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10

Real-time monitoring of the batch process is beneficial as many batch processes are employed to produce high value-added products. Although many theoretical studies deal with the monitoring algorithm, the platform where to apply these ideas as well as the algorithm based on a mechanistic model are rarely proposed. In this study, the gPROMS Digital Applications Platform (gDAP) that takes care of all activities for online implementation and execution of models is described. This platform allows connecting a mechanistic cell culture model implemented in the gPROMS FormulatedProducts modeling environment with plant data and web-based Dashboards, which displays both plant data and values estimated by the model. The mathematical model is used to predict the process performance, and it is started by the user from the dashboards. Model outputs are instantly stored in a database, where all the plant and model data are historized. Users can access the dashboards which displays the values stored in the database through the internet. The proposed platform is applied to a monoclonal antibody production process.

Enaminones in Heterocyclic Synthesis part 2: One-Pot Synthesis of Some New Indeno [3,2-b] pyridines

Hammouda, M.,Mashaly, M.,Fadda, A.A. The Pharmaceutical Society of Korea 1995 Archives of Pharmacal Research Vol.18 No.3

Six new indeno[3,2-b]pyridine derivatives were synthesized via reactions of 1-phenylamino-3-indenone with cyano olefins.

Development and Stability Evaluation of Enteric Coated Diclofenac Sodium Tablets Using AquaPolish E.

( Zaid A. N. ),( Fadda A. M. ),( Nator S. ),( Qaddumi A. ) 한국약제학회 2011 Journal of Pharmaceutical Investigation Vol.41 No.4

The aim of this study was to develop a stable enteric coated diclofenac sodium (DFS) tablets using Aqua- Polish E without using a subcoat. DFS uncoated tablets were manufactured through the non direct compression process. AquaPolish E white aqueous coating dispersion was used as enteric coating material. This film forming polymer is a mixture of selected polymethacrylic/ethylacrylate copolymers. The stability of the obtained enteric coated tablets was evaluated according to ICH guidelines. No signs of disintegration or cracking was observed when they placed in 0.1N HCl solution (pH1.2), but they were completely disintegrated within 10 minutes when they placed in buffered solution at pH6.8. Dissolution test was also conducted by placing tablets in 0.1 N HCl for 2 hours and then 1 hour in phosphate buffer at pH 6.8. Less than 0.9 % of drug was released in the acidic phase and up to 97% in the basic medium. These findings suggest that aqueous enteric coating with AquaPolish E system is an easy and economical approach for preparing stable DFS enteric coat without the use of a subcoating layer.

Enhancement of pool boiling heat transfer in water on aluminum surface with high temperature conductive microporous coating

Godinez, Juan C.,Fadda, Dani,Lee, Jungho,You, Seung M. Elsevier 2019 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.132 No.-

<P><B>Abstract</B></P> <P>The effects of an aluminum high temperature conductive microporous coating (Al-HTCMC) on the nucleate boiling heat transfer (NBHT) coefficient and critical heat flux (CHF) are studied in saturated distilled water at 1 atm. Aluminum powders with three different mean particle diameters (d<SUB>m</SUB> = 11, 24, and 66 µm) are used in the fabrication of the Al-HTCMC. For each mean particle diameter, an optimal coating thickness to yield the highest NBHT coefficient is determined. The optimized Al-HTCMC thickness is found to result in comparable NBHT coefficients regardless of the particle diameter. Pool boiling tests with a plain aluminum surface are used for comparison. The coated and plain aluminum surfaces are treated equally before the pool boiling tests to establish a Boehmite oxidation nano layer on the aluminum surfaces. Following the Boehmite treatment, the contact angle is unmeasurable (∼0°) with the Al-HTCMC surface and 12° with a plain aluminum surface. Then, pool boiling tests are performed and reveal comparable CHF (1725–1850 kW/m<SUP>2</SUP>) values with or without the Al-HTCMC. However, the Al-HTCMC is shown experimentally to improve the NBHT coefficient by a factor of five as the wall superheat is reduced by from 31 K to 6 K just before CHF. The results obtained are also compared to similar work using an HTCMC layer on a copper surface to demonstrate the performance of the Al-HTCMC.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Study of the effects of an aluminum high temperature conductive microporous coating on pool boiling. </LI> <LI> Aluminum microporous coating (Al-HTCMC) fabricated using different aluminum powder particle sizes. </LI> <LI> Coating thickness optimized to yield highest nucleate boiling heat transfer coefficients. </LI> <LI> Boehmite treatment applied to aluminum surface with the microporous coating. </LI> </UL> </P>

Cardiac Autonomic Control and Neural Arousal as Indexes of Fatigue in Professional Bus Drivers

Lecca, Luigi I.,Fadda, Paolo,Fancello, Gianfranco,Medda, Andrea,Meloni, Michele Occupational Safety and Health Research Institute 2022 Safety and health at work Vol.13 No.2

Background: Bus driving is a mentally demanding activity that requires prolonged attention to ensure safety. The aim of the study was to assess mental fatigue caused by driving a public bus and to find a profile of workers at higher risk. Methods: We evaluated changes of critical flicker fusion (CFF) (index of central arousal) and heart rate variability (HRV) (index of autonomic balance) in a 6-hour driving shift on a real route, in 31 professional bus drivers, and we tested the influence of personal factors such as sleep quality, BMI, and age. Paired t-test was used to test differences of CFF and HRV between both initial and final phase of driving, while multiple linear regression tested the influence of personal variables on the indexes of mental fatigue. Results: Results showed that CFF significantly decreased after 6 hours of bus driving (41.91 Hz, sd 3.31 vs. 41.15 Hz, sd 3.15; p = 0.041), and heart rate significantly decreased in the final phase of driving, with respect to the initial phase (85 vs. 78 bpm, p = 0.027). Increasing age (beta = -0.729, p = 0.022), risk of obstructive sleep apnea syndrome (beta = -0.530, p = 0.04), and diurnal sleepiness (beta = -0.406, p = 0.017) showed a significant effect on influencing mental fatigue. Conclusion: Elderly drivers at higher risk of sleep disorders are more prone to mental fatigue, when exposed to driving activity. Monitoring indexes of central arousal and autonomic balance, coupled with the use of structured questionnaires can represent a useful strategy to detect profile of workers at higher risk of mental fatigue in such duty.

SPECTROSCOPICALLY SELECTED<i>SPITZER</i>24<i>μm</i>ACTIVE GALACTIC NUCLEI

Choi, P. I.,Yan, Lin,Helou, G.,Storrie-Lombardi, L. J.,Fadda, D.,Im, M.,Shim, H. IOP Publishing 2011 The Astrophysical journal Vol.732 No.1

<P>We investigate the active galactic nucleus (AGN) sub-population of a 24 mu m flux-limited galaxy sample in the Spitzer Extragalactic First Look Survey. Using deep Keck optical spectroscopy and a series of emission-line diagnostics, we identify AGN-dominated systems over broad redshift 0 < z < 3.5 and luminosity 9 < log(L-TIR) < 14 ranges, with sample means of < z > = 0.85 and < log(LTIR)> = 11.5. We find that down to the flux limits of our Spitzer MIPS sample (f(24) > 200 mu Jy), 15%-20% of sources exhibit strong AGN signatures in their optical spectra. At this flux limit, the AGN population accounts for as much as 25%-30% of the integrated 24 mu m flux. This corresponds to an MIR AGN contribution approximate to 2-3x greater than that found in ISOCAM 15 mu m studies that used X-ray AGN identifications. Based on our spectroscopically selected AGN sample, we also investigate the merits of Infrared Array Camera (IRAC) color selection for AGN identification. Our comparison reveals that although there is considerable overlap, a significant fraction of spectroscopic AGNs are not identifiable based on their MIR colors alone. Both the measured completeness and reliability of the IRAC color selections are found to be strongly dependent on the MIR flux limit. Finally, our spectroscopic AGN sample implies as much as a 3x higher AGN surface density at high redshift (z > 1.2) than that of recent optical surveys at comparable optical flux limits, suggestive of a population of heavily obscured, optical/UV reddened AGNs.</P>