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Study of Thermal and Hydraulic Performances of Circular and Square Ribbed Rough microchannels Using LBm

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Journal of Thermal Science 2015年第6期24卷 549-556页

作者： m.A.taher H.d.Kim Y.W Lee department of mechanical and Automotive Engineering Pukyong National University department of mechanical Engineering Andong National University

The effects of roughness geometries and relative roughness height at the slip flow regime to investigate the thermal and hydraulic performances of microchannel have been considered in the present article using a thermal Lattice Boltzmann method(TLBm).A two dimensional 9-bit(d2Q9)single relaxation time(SRT)model is used to simulate this *** micro-flows,the local density variation is still relatively small,but the total density changes,therefore,in order to account this density variation and its effect on the kinematic viscosityν,a new relaxation time proposed by Niu et al.[13]is *** roughness geometry is modeled as a series of square and circular riblets with a relative roughness height from 0%to 10%of the channel *** friction coefficients in terms of Poiseuille number(Pn)and the dimensionless heat transfer rate in terms of Nusselt number(Nu)have been discussed in order to analyze the roughness *** thermal-hydraulic performance(η)is calculated considering the simultaneous effects of thermal and fluid friction(pressure drop)at the slip flow regime at Knudsen number,Kn,ranging from 0.01 to 0.10 with other controlling parameters for both kind of *** results have been compared with previous published works and it is found to be in very good agreement.

关键词： Lattice-Boltzmann Friction factor Knudsen number Surface Roughness

Exploring the impact of stratification on the dynamics of bioconvective thixotropic fluid conveying tiny particles and Cattaneo-Christov model:Thermal storage system application

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Propulsion and Power Research 2024年第3期13卷 416-432页

作者： T.Oreyeni m.d.Shamshuddin A.m.Obalalu A.Saeed Nehad Ali Shah department of Physical Sciences Mathematics Programme UnitPrecious Cornerstone UniversityIbadanNigeria department of Computer Science and Artificial Intelligence(mathematics) SR UniversityWarangalTelangana State 506371India department of mathematics Augustine University Ilara EpeLagosNigeria Center of Excellence in Theoretical and Computational Science(TaCS-CoE) Faculty of ScienceKing Mongkut’s University of Technology Thonburi(KMUTT)126 Pracha Uthit Rd.BangModThung KhruBangkok 10140Thailand department of mathematics and Statistics College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh 11623Saudi Arabia

Stratified thermal storage promotes energy sustainability by storing excess energy during times of low demand for later use making it possible to integrate renewable energy sources like solar and *** communication discusses the significance of triple stratifica-tion using the Cattaneo-Christov model in the bioconvectiveflow of thixotropicfluid coexisting with nanoparticles and gyrotactic *** Cattaneo-Christov heat and massflux is incorporated into thefluid model allowing more accurate prediction of heat and mass phenomena in thefluid *** governing partial differential equations that describefluidflow are parametrized to yield an ordinary differential equation system by adopting suitable *** series solutions are obtained by applying the homotopy analysis method(ham).The effects of relevant parameters on the various profiles are revealed and accurately *** is observed that amplified thermal stratification lowers the temperature of ***,Brownian motion is used to illustrate the random movement of small particles suspended in liquids,and it is envisioned that the concentration distribution is significantly influenced by the Brownian motion of nanoparticles.

关键词： Cattaneo-Christov model Stratification Bioconvection Nanofluid

development of Tailored Structure and Tensile Properties of Thermomechanical Treated micro Alloyed Low Carbon dual Phase Steel

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materials Sciences and Applications 2020年第12期11卷 851-866页

作者： Hany Khalifa G. m. megahed taher el-Bitar m.ham.d A. Taha Faculty of Engineering Ain-Shams University Cairo Egypt EZZ Steel Cairo Egypt Central metallurgical R & d Institute (CmRdI) Helwan Cairo Egypt

direct hot rolled dual phase steel production represents a challenging route, compared with cold rolled and intercritical annealing process, due to complex and sophisticated control of the hot strip mill processing parameters. Instead, high technology compact slab production plant offers economic advantages, adequate control and prompt use of the advanced thermomechanical controlled rolling. The current work aims to obtain different structures and tensile properties by physical simulation of direct hot rolled niobium micro alloyed dual phase low carbon steel by varying the metallurgical temperatures of hot strip mill plant. This starts with adaptation of the chemical analysis of a low carbon content to fall far from the undesired peritectic region to avoid slab cracking during casting. Thermodynamic and kinetics calculations by Thermo-Calc 2020 and Jmat pro software are used to define the transformation’s temperatures Ae1 and Ae3 as well as processing temperatures;namely of reheating, finishing rolling, step cooling and coiling temperatures. The results show that the increase of finishing rolling temperature from 780°C to 840°C or decreasing either of step cooling duration at ferrite bay from 7 to 4 seconds, enhances yield and tensile strengths, all due to more martensite volume fraction formation. The yield and tensile strengths also increase with decreasing coiling temperature from 330°C to 180°C, which is explained due to the increase of dislocation densities resulted from the sudden shape change during martensite formation at the lower coiling temperature in additional to the self-tempering of martensite formed at higher coiling temperatures which soften the dual phase steel.

关键词： micro-Alloyed Steel dual Phase Steel Thermomechanical Simulation Thermomechanical Rolling Compact Slab Production CSP Hot Strip mill HSm

Postoperative Radiotherapy in Bladder Cancer Patients: 5-Year Institutional Experience of National Cancer Institute, Cairo University

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Journal of Cancer Therapy 2015年第7期6卷 579-593页

作者： Azza m. Nasr magda el mongi mamdouh Hagag manar m. moneer Hisham el Hossieny Azza taher Sherif magdy Radiation Oncology department National Cancer Institute Cairo University Giza Egypt Clinical Oncology department Faculty of Medicine Cairo University Giza Egypt Cancer Epidemiology and Biostatistics department National Cancer Institute Cairo University Giza Egypt

Purpose: Adjuvant radiation therapy could reduce loco regional failure, but currently has no defined role because of previously reported morbidity. NCI-Cairo routine work is to give adjuvant PORT for locally advanced bladder carcinoma patients. The aim of this work is to re-evaluate this protocol regarding its effect on prognosis and complications. Patients and method: A retrospective study included 208 patients with pathologically proven bladder cancer who presented to the NCI, Cairo University from 2007-2011. All of them underwent RC with bilateral PLNd followed by conventional post-operative radiotherapy in 2 - 6 weeks after surgery for 5000 cGy in 25 fractions, over 5 weeks using 2d technique. Analysis of data from their files was done for the treatment results, prognostic factors and complications. Results: Three years overall survival (OS) and disease free survival (dFS) for the whole group was ~60%, and 54% respectively in favour of the female gender, non-smokers, Squamous cell carcinoma patients, low grade tumours (grade 1 and 2) negative margins, N0, pT2b and early stage group showed the best prognoses. The 3 years metastases free survival (mFS) was ~71%. Only four factors showed a significant relation with the mFS which were the grade, LN status, T-stage and group staging. The local recurrence rate (LRC) at 2 years for the whole group was ~95% and 94% at 3 years. Only surgical margin status and extent of LN dissection had a significant impact on the LRC. Conclusions: Adjuvant radiotherapy shows sustained improvement in the loco regional control, and should be recommended for patients with locally advanced disease especially those with less than 10 dissected lymph nodes and those with positive margins.

关键词： Bladder Cancer Radiotherapy Pelvic Irradiation

A Study on Heat Transfer Enhancement through Various Nanofluids in a Square Cavity with Localized Heating

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Energy Engineering 2021年第6期118卷 1659-1679页

作者： Sheikh Hassan didarul Ahasan Redwan md.mamun molla Sharaban Thohura m.Abu taher Sadia Siddiqa department of mathematics and Physics North South UniversityDhakaBangladesh Center for Applied and Scientific Computing(CASC) North South UniversityDhakaBangladesh department of mathematics Jagannath UniversityDhakaBangladesh department of mathematics Dhaka University of Engineering and TechnologyGazipurBangladesh department of mathematics COMSAT University IslamabadAttock CampusAttockPakistan

A two-dimensional(2d)laminar flow of nanofluids confined within a square cavity having localized heat source at the bottom wall has been *** governing Navier–Stokes and energy equations have been non dimensionalized using the appropriate non dimensional variables and then numerically solved using finite volume *** flow was controlled by a range of parameters such as Rayleigh number,length of heat source and nanoparticle volume *** numerical results are represented in terms of isotherms,streamlines,velocity and temperature distribution as well as the local and average rate of heat transfer.A comparative study has been conducted for two different base fluids,ethylene glycol and water as well as for two different solids Cu and Al_(2)O_(3).It is found that the ethylene glycol-based nanofluid is superior to the water-based nanofluid for heat transfer enhancement.

关键词： Nanofluids finite volume method heat transfer enhancement localized heating

multi-redox phenazine/non-oxidized graphene/cellulose nanohybrids as ultrathick cathodes for high-energy organic batteries

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Nano Research 2021年第5期14卷 1382-1389页

作者： Youngjin ham Vitalii Ri Jin Kim Yeoheung Yoon Jinho Lee Kisuk Kang Ki-Seok An Chunjoong Kim Seokwoo Jeon department of materials Science and Engineering Advanced Battery CenterKorea Advanced Institute of Science and Technology(KAIST)Daejeon34141Republic of Korea department of materials Science and Engineering Chungnam National UniversityDaejeon34134Republic of Korea Thin Film materials Research Center Korea Research Institute of Chemical Technology(KRICT)Daejeon34114Republic of Korea department of materials Science and Engineering Seoul National UniversitySeoul08826Republic of Korea

Various redox-active organic molecules can serve as ideal electrode materials to realize sustainable energy storage systems. Yet, to be more appropriate for practical use, considerable architectural engineering of an ultrathick, high-loaded organic electrode with reliable electrochemical performance is of crucial importance. Here, by utilizing the synergetic effect of the non-covalent functionalization of highly conductive non-oxidized graphene flakes (NOGFs) and introduction of mechanically robust cellulose nanofiber (CNF)-intermingled structure, a very thick (≈ 1 mm), freestanding organic nanohybrid electrode which ensures the superiority in cycle stability and areal capacity is reported. The well-developed ion/electron pathways throughout the entire thickness and the enhanced kinetics of electrochemical reactions in the ultrathick 5,10-dihydro-5,10-dimethylphenazine/NOGF/CNF (dmPZ-NC) cathodes lead to the high areal energy of 9.4 mWh·cm−2 (= 864 Wh·kg−1 at 158 W·kg−1). This novel ultrathick electrode architecture provides a general platform for the development of the high-performance organic battery electrodes.

关键词： energy storage organic electrodes batteries graphene cellulose nanofibers

An Iterative Relaxation Approach to the Solution of the hamilton-Jacobi-Bellman-Isaacs Equation in Nonlinear Optimal Control

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 360-366页

作者： m.d.S.Aliyu department of electrical Engineering King Faisal University Al-Ahsa 31982 Saudi Arabia IEEE

In this paper, we propose an iterative relaxation method for solving the hamilton-Jacobi-Bellman-Isaacs equation(HJBIE) arising in deterministic optimal control of affine nonlinear systems. Local convergence of the method is established under fairly mild assumptions, and examples are solved to demonstrate the effectiveness of the method. An extension of the approach to Lyapunov equations is also discussed. The preliminary results presented are promising, and it is hoped that the approach will ultimately develop into an efficient computational tool for solving the HJBIEs.

关键词： Affine nonlinear system bounded continuous function convergence hamilton-Jacobi-Bellman-Isaacs equation Lyapunov equation relaxation method Riccati equation

Treatment of moderate to severe keratoconus with 6-mm Intacs SK

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International Journal of Ophthalmology(English edition) 2012年第4期5卷 513-516页

作者： Sasan Niknam mehrdad Shamshiri Seyed Sahabaldin Shahrzad Abbas Alipour mohammad Bagher Rajabi mohammad taher Rajabi Cornea Unit Dr Khodadoust Eye HospitalShiraz Iran department of Ophthalmology Dr. Khodadoust Eye HospitalShiraz Iran department of Ophthalmology Khalili HospitalShiraz Iran department of Epidemiology and Statistics Faculty of Nutrition and HealthShiraz Iran department of Ophthalmology Eye Research Center Farabi Eye Hospital Tehran University of Medical SciencesTehran Iran

·AIm:To evaluate the effect of Intacs SK corneal ring segment implant for treatment of patients with moderate to severe keratoconus, who have clear central cornea and cannot tolerate contact lens. ·mETHOdS:In this prospective, non-comparative, intervent- ional case series study performed in dena Hospital, Shiraz, Iran, thirty-seven eyes of thirty-six patients with moderate to severe keratoconus, clear central cornea, and contact lens intolerance were enrolled and underwent Intacs SK corneal ring segment implantation. Preoperatively, uncorrected distance visual acuity (UCdVA), best-corrected distance visual acuity (BCdVA), central corneal thickness(CCT) and average keratometry (Av-K) were measured and compared with post-operative results at one week, one month, three months, and six months. ·RESULTS:mean preoperative UCdVA and BCdVA were (1.32±0.31) logmAR and (1.07±0.27) logmAR, respectively. Av-K was (52.13±0.39)d, and the CCT was (432±39.5)μm. Post-operative examinations showed a clinically significant improvement in both UCdVA and BCdVA (P d on the time of assessment on both UCdVA and BCdVA and both parameters had a continuous improvement during the follow-up period. Three months after operation there was a statistical significant reduction of Av-K (P =0.0001), but there were no significant changes in CCT (P =0.149). ·CONCLUSION:Intacs SK corneal ring segment implants seem to be a safe and effective treatment option for patients who have keratoconus, clear central cornea, and contact lens intolerance.

关键词： keratoconus Intacs myopia

Fundamental principles and development of proximity-field nanopatterning toward advanced 3d nanofabrication

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Nano Research 2021年第9期14卷 2965-2980页

作者： Sang-Hyeon Nam Gayea Hyun donghwi Cho Seonggon Han Gwangmin Bae Haomin Chen Kisun Kim Youngjin ham Junyong Park Seokwoo Jeon department of materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea department of mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina School of materials Science and Engineering Kumoh National Institute of TechnologyGumiGyeongbuk 39177Republic of Korea department of Energy Engineering Convergence Kumoh National Institute of TechnologyGumiGyeongbuk 39177Republic of Korea KAIST Institute for NanoCentury(KINC) KAISTDaejeon 34141Republic of Korea

Three-dimensional(3d)nanoarchitectures have offered unprecedented material performances in diverse applications like energy storages,catalysts,electronic,mechanical,and photonic *** outstanding performances are attributed to unusual material properties at the nanoscale,enormous surface areas,a geometrical uniqueness,and comparable feature sizes with optical *** the practical use of the unusual nanoscale properties,there have been developments for macroscale fabrications of the 3d nanoarchitectures with process areas over centimeter *** the many fabrication methods for 3d structures at the nanoscale,proximity-field nanopatterning(PnP)is one of the promising techniques that generates 3d optical holographic images and transforms them into material structures through a lithographic *** conformal and transparent phase masks as a key factor,the PnP process has advantages in terms of stability,uniformity,and reproducibility for 3d nanostructures with periods from 300 nm to several *** merits of realizing precise 3d features with sub-100 nm and rapid processes are attributed to the interference of coherent light diffracted by phase *** this review,to report the overall progress of PnP from 2003,we present a comprehensive understanding of PnP,including its brief history,the fundamental principles,symmetry control of 3d nanoarchitectures,material issues for the phase masks,and the process area expansion to the wafer-scale for the target ***,technical challenges and prospects are discussed for further development and practical applications of the PnP technique.

关键词： proximity-field nanopatterning three-dimensional(3d)nanostructures phase mask interference lithography