Kinetics of Cell Growth and Cyclosporin A Production by Tolypocladium inflatum when Scaling Up from Shake Flask to Bioreactor

( El Enshasy H. ),( Y. Abdel Fattah ),( A. Atta ),( H. Omar ),( S. Abou El Magd ),( R. Abou Zahra ),( M. Anwar ) 한국미생물 · 생명공학회 2008 Journal of microbiology and biotechnology Vol.18 No.1

The kinetics of cell growth and Cyclosporin A (Cyc A) production by Tolypocladium inflatum were studied in shake flasks and bioreactors under controlled and uncontrolled pH conditions. In the case of the shake flask, the production time was extended to 226 h and the maximal antibiotic concentration was 76 mg/l. When scaling up the cultivation process to a bioreactor level, the production time was reduced to only 70 h with a significant increase in both the cell growth and the antibiotic production. The maximal dry cell weights in the case of the controlled pH and uncontrolled pH cultures in the bioreactor were 22.4 g/l and 14.2 g/l, respectively. The corresponding maximal dry cell weight values did not exceed 7.25 g/l with the shake flask cultures. The maximal values for Cyc A production were 144.72 and 131.4 mg/l for the controlled and uncontrolled pH cultures, respectively. It is also worth noting that a significant reduction was observed in both the dry cell mass and the antibiotic concentration after the Cyc A production phase, whereas the highest rate of antibiotic degradation was observed in the stirred tank bioreactor with an uncontrolled pH. Morphological characterization of the micromorphological cell growth (mycelial/pellet forms) was also performed during cultivation in the bioreactor.

Nitrogen plasma synthesis of flexible supercapacitors based on reduced graphene oxide/aloe vera/carbon nanotubes nanocomposite

M. M. Atta,Hesham M. H. Zakaly,N. Almousa,A. M. Abdel Reheem,M. Madani,Usama.F. Kandil,A. M. A. Henaish,Eman O. Taha 한국탄소학회 2023 Carbon Letters Vol.33 No.6

Flexible supercapacitors (FS) are ideal as power backups for upcoming stretchable electronics due to their high power density and good mechanical compliance. However, lacking technology for FS mass manufacturing is still a significant obstacle. The present study describes a novel method for preparing FS based on reduced graphene oxide (RGO) using the N+ plasma technique, in which N+ reduces graphene oxide on the surface of a cotton/polyester substrate. The effect of aloe vera (AV) as a natural reducing & capping agent and carbon nanotubes (CNT) as nanoconductors on the electrochemical performance of the electrodes is studied. FESEM and XPS were employed to investigate the electrodes' structural and chemical composition of electrodes. The galvanostatic charge–discharge curves of electrodes revealed the enhancement of the electrochemical activity of the as-prepared electrode upon additions of AV and CNT. The areal capacitance of the RGO, RGO/AV, and RGO/ AV/CNT supercapacitors at 5 mV/s was 511, 1244.5, and 1879 mF/cm2, respectively. The RGO electrode showed capacitive retention of 80.9% after 2000 cycles enhanced to 89.7% and 92% for RGO/AV and RGO/AV/CNT electrodes, respectively. The equivalent series resistance of the RGO electrode was 126.28 Ω, decreased to 56.62 and 40.06 Ω for RGO/AV and RGO/ AV/CNT electrodes, respectively.

Measurement of the Ratioσtt¯/σZ/γ*→lland Precise Extraction of thett¯Cross Section

Aaltonen, T.,Adelman, J.,Á,lvarez Gonzá,lez, B.,Amerio, S.,Amidei, D.,Anastassov, A.,Annovi, A.,Antos, J.,Apollinari, G.,Apresyan, A.,Arisawa, T.,Artikov, A.,Asaadi, J.,Ashmanskas, W.,Atta American Physical Society 2010 Physical review letters Vol.105 No.1

<P>We report a measurement of the ratio of the tt to Z/관{*} production cross sections in sqrt[s]=1.96??TeV pp collisions using data corresponding to an integrated luminosity of up to 4.6??fb{-1}, collected by the CDF II detector. The tt cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/관{*}?l cross section predicted by the standard model, the extracted tt cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result ?{tt}=7.70±0.52??pb, for a top-quark mass of 172.5??GeV/c{2}.</P>

Search for new color-octet vector particle decaying to tt¯ in pp¯ collisions at s=1.96 TeV

Aaltonen, T.,Adelman, J.,Á,lvarez Gonzá,lez, B.,Amerio, S.,Amidei, D.,Anastassov, A.,Annovi, A.,Antos, J.,Apollinari, G.,Apresyan, A.,Arisawa, T.,Artikov, A.,Asaadi, J.,Ashmanskas, W.,Atta Elsevier 2010 Physics letters: B Vol.691 No.4

<P><B>Abstract</B></P><P>We present the result of a search for a massive color-octet vector particle, (e.g. a massive gluon) decaying to a pair of top quarks in proton–antiproton collisions with a center-of-mass energy of 1.96 TeV. This search is based on 1.9<SUP> fb−1</SUP> of data collected using the CDF detector during Run II of the Tevatron at Fermilab. We study tt¯ events in the lepton+jets channel with at least one <I>b</I>-tagged jet. A massive gluon is characterized by its mass, decay width, and the strength of its coupling to quarks. These parameters are determined according to the observed invariant mass distribution of top quark pairs. We set limits on the massive gluon coupling strength for masses between 400 and 800 GeV/<SUP>c2</SUP> and width-to-mass ratios between 0.05 and 0.50. The coupling strength of the hypothetical massive gluon to quarks is consistent with zero within the explored parameter space.</P>

Effect of nitrogen ions on the structural, optical, and thermal properties of polyvinyl alcohol/starch blend

Atta M.M.,Abdel Reheem A.M. 한국물리학회 2022 Current Applied Physics Vol.36 No.-

This work examines the properties of polyvinyl alcohol (PVA)/starch film containing glycerol as a plasticizer under exposure to different nitrogen ion fluence. The prepared PVA/starch blend was irradiated with ion fluence from 3 × 1017 to 12 × 1017 ions.cm− 2 . From FTIR, the ion beam irradiation attack and weakens the C–H bond in PVA/starch blend. From XRD findings, the crystallite size of the blend decreased at 3 × 1017 ions/cm2 while it increased at higher fluence up to 9 × 1017 ions/cm2 . This indicates the degradation of the blend at low ion fluence compared to crosslinking at high ion fluence. Also, the optical bandgap of the blend was decreased with an increase in ion fluence. Furthermore, the effect of N+ ions on some optical dispersion parameters is studied. The thermal stability of the PVA/starch blend shows a decrease in thermal stability upon irradiation with 3 × 1017 ions/cm2 compared to higher thermal stability at higher doses up to 9 × 1017 ions/cm2 .

Oxygen plasma irradiation-induced surface modifications on HDPE and PET polymeric films

Atta A.,Althubiti N. A.,Althubiti S. 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.79 No.4

Nowadays, plasma treatments are one of the powerful techniques usually accomplished to change the surface characteristics of polymeric films. This study presents the influence of oxygen plasma irradiation on the structural and the optical properties of high-density polyethylene (HDPE) and polyethylene terephthalate (PET) films that will be used in optoelectronic devices. The films were irradiated with an oxygen plasma for duration of 3, 4.5, and 6 min. The surface structure of the films was investigated utilizing X-ray diffraction (XRD). For an irradiation time of 6 min, the crystallite size changes from 13.9 to 19.7 nm and from 5.7 to 6.5 nm for pristine HDPE and PET, respectively. The UV–Vis optical absorption spectrum demonstrates a slight shift in the absorption edge towards the visible region caused by the oxygen irradiation time for both the HDPE and the PET films. Increasing the irradiation time leads to a slight decrease in the optical energy band gap Eg and to an improvement in the carbon cluster number N. The results show clear improvements in the optical properties of HDPE and PET due to plasma irradiation that make them good candidates for use in optoelectronics applications.

Characterization and dielectric studies of hydrogen-beam-irradiated PDMS polymeric materials

Haifa A. Al‑Yousef,B. M. Alotaibi,A. Atta,M. M. Abdel‑Hamid 한국고분자학회 2023 Macromolecular Research Vol.31 No.8

In this work, PDMS films are treated with varying fluence of hydrogen ion beams (6 × 1017, 9 × 1017, and 12 × 1017 ions/cm2) for used in storage energy devices. XRD and FTIR were used to analyze the PDMS films. Furthermore, the SEM is employed to study the morphological alterations in treated PDMS films. Both XRD and FTIR result indicated that PDMS is chemically interacting after ion treatment. In addition, the dielectric parameters of PDMS films are measured using an LCR device in the frequencies 102–106 Hz. After PDMS exposed to 12 × 1017 ions/cm2, the dielectric constant of the PDMS increased from 23.4 to 44.8, and energy density increased from 1.01 × 10–4 to 1.92 × 10–4 J/m3, while the conductivity increased from 0.29 × 10–7 to 4.3 × 10–7 S/cm. Moreover, the real M′ decreased from 0.198 for PDMS to 0.165 for 6 × 1017 ions/cm2 and to 0.052 at 12 × 1017 ions/cm2, while the imaginary M″ is decreased from 0.205 to 0.155 for 6 × 1017 ions/cm2, and to 0.069 for 12 × 1017 ions/cm2. The studies indicated that the structure as well as electrical characteristics of the treated PDMS had been improved, which allowing being used these substances in different electronic instrumentations.

Diet-Right: A Smart Food Recommendation System

( Faisal Rehman ),( Osman Khalid ),( Nuhman Ul Haq ),( Atta Ur Rehman Khan ),( Kashif Bilal ),( Sajjad A. Madani ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.6

Inadequate and inappropriate intake of food is known to cause various health issues and diseases. Due to lack of concise information about healthy diet, people have to rely on medicines instead of taking preventive measures in food intake. Due to diversity in food components and large number of dietary sources, it is challenging to perform real-time selection of diet patterns that must fulfill one`s nutrition needs. Particularly, selection of proper diet is critical for patients suffering from various diseases. In this article, we highlight the issue of selection of proper diet that must fulfill patients` nutrition requirements. To address this issue, we present a cloud based food recommendation system, called Diet-Right, for dietary recommendations based on users` pathological reports. The model uses ant colony algorithm to generate optimal food list and recommends suitable foods according to the values of pathological reports. Diet-Right can play a vital role in controlling various diseases. The experimental results show that compared to single node execution, the convergence time of parallel execution on cloud is approximately 12 times lower. Moreover, adequate accuracy is attainable by increasing the number of ants.

Worth of the Three Dimensional Simulations of Seepage in the Vicinity of Heading-up Structures

Mohamed A. Gad,Doaa Anas,Nahla A. Atta,Ghada Samy 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.2

This paper evaluates the three dimensional effects in studying seepage in the vicinity of heading up structures. An artificial heading-up structure installed on pervious soil is studied using both a 3D model (Seep3D) and a vertical 2D model (SEEP2D). The uplifts under the apron and the exit gradients resulting from both models are compared for different structure configurations including the presence and lack of sheetpiles for both laterally homogeneous and heterogeneous conditions. In addition, the effects of downstream wing walls (guide walls) on seepage are also assessed. The results showed that the exit gradient in the 3D simulations can reach almost double its value in the 2D simulations in different configurations. The existence of downstream guide walls can also lead to significant increase in the exit gradient. The paper proves that studying seepage in 3D can significantly become critical over the traditional 2D approach especially in cases of significant lateral heterogeneity.

Synthesis, structural characterization, and optical properties of PVA/MnO2 materials for optoelectronics applications

Norah A. M. Alsaif,A. Atta,E. Abdeltwab,M. M. Abdel‑Hamid 한국고분자학회 2024 Macromolecular Research Vol.32 No.1

In this study, polyvinyl alcohol (PVA) was mixed with concentration of 5%, 7.5%, and 10% of manganese dioxide ( MnO2) to form PVA/MnO2 films using solution cast approach method. The X-ray diffraction (XRD) verified that the nanomaterials films were successfully fabricated. The scanning electron microscope (SEM) illustrates the uniform MnO2 dispersion within the PVA host matrix. Additionally, the influence of MnO2 on the optical properties is recorded. The refractive index (n0) is improved by adding MnO2, from 1.29 for PVA to 1.87 for PVA/5%MnO2 and 2.86 for PVA/10%MnO2. The PVA had a dispersion energy of 2.53 eV, while PVA with 5% MnO2 had 4.86 eV, PVA with 7.5% MnO2 had 5.74 eV, and PVA with 10%MnO2 had 7.12 eV. In addition, the oscillation energy E0 decreased from 3.79 for PVA to 1.94, 1.72, and 0.99 eV, respectively for PVA/5%MnO2, PVA/7.5%MnO2, and PVA/10%MnO2. It is evident from the data that the incorporation of MnO2 to the PVA polymer alters its optical properties. This proved the existence of strong interactions of PVA and MnO2 due to the modification of the PVA/MnO2 electronic structure. Moreover, the plasma frequency W p value increased from 0.79 × 1013 s− 1 for PVA to 2.06 × 1013 s− 1 for PVA/10%MnO2. These shifts in W p provided the polarization is modified for the PVA/MnO2. The results obtained in this study provide evidence of the advantages associated with the utilization of MnO2 nanoparticles as a filler of improved polymeric structures. These findings also propose the potential suitability of MnO2 nanoparticles for application in the field of optics and electronic devices.