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Effect of equal channel angular extrusion on Al-6063 bending fatigue characteristics

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International Journal of Minerals,Metallurgy and Materials 2015年第4期22卷 395-404页

作者： J.Nemati G.H.Majzoobi s.sulaiman B.T.H.T.Baharudin M.A.Azmah Hanim Department of Mechanical and Manufacturing Engineering University Putra Malaysia Engineering Faculty Bu-Ali Sina University school of Mechanics Islamic Azad UniversityTakestan Branch

The purpose of this investigation was to refine the grains of annealed 6063 aluminum alloy and to improve its yield stress and ul- timate strength. This was accomplished via the equal channel angular extrusion （ECAE） process at a temperature of 200℃ using route A, with a constant ram speed of 30 mm/min through a die angle of 90° between the die channels for as many as 6 passes. The experiments were conducted on an Avery universal testing machine. The results showed that the grain diameter decreased from 45 μm to 2.8 μm after 6 extru- sion passes. The results also indicated that the major improvement in fatigue resistance occurred after the first pass. The subsequent passes improved the fatigue life but at a considerably lower rate. A maximum increase of 1100% in the case of low applied stresses and an ap- proximately 2200% increase in fatigue resistance in the case of high applied stresses were observed after 5 passes. The improvement of fa- tigue resistance is presumed to be due to （1） a reduction in the size and the number of si crystals with increasing number of ECAE passes, （2） the aggregation of Cu during the ECAE process, （3） the formation and growth of CuA12 grains, and （4） grain refinement of the A1--6063 alloy during the ECAE process.

关键词： aluminum alloys equal channel angular pressing bending fatigue life grain size microstructure

Improvements in the microstructure and fatigue behavior of pure copper using equal channel angular extrusion

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International Journal of Minerals,Metallurgy and Materials 2014年第6期21卷 569-576页

作者： J.Nemati G.H.Majzoobi s.sulaiman B.T.H.T.Baharudin M.A.Azmah Hanim Department of Mechanical and Manufacturing Engineering Universiti Putra Malaysia school of Mechanics Islamic Azad UniversityTakestan Branch348194 9479 Takestan Iran

In this study, annealed pure copper was extruded using equal channel angular extrusion （ECAE） for a maximum of eight passes. The fatigue resistance of extruded specimens was evaluated for different passes and applied stresses using fatigue tests, fractography, and metallography. The mechanical properties of the extruded material were obtained at a tensile test velocity of 0.5 mm/min. It was found that the maximum increase in strength occurred after the 2nd pass. The total increase in ultimate strength after eight passes was 94%. The results of fatigue tests indicated that a significant improvement in fatigue life occurred after the 2nd pass. In subsequent passes, the fatigue life con-tinued to improve but at a considerably lower rate. The improved fatigue life was dependent on the number of passes and applied stresses. For low stresses （or high-cycle fatigue）, a maximum increase in fatigue resistance of approximately 500%was observed for the extruded material after eight passes, whereas a maximum fatigue resistance of 5000%was obtained for high-applied stresses （or low-cycle fatigue）. Optical microscopic examinations revealed grain refinements in the range of 32 to 4 μm. A maximum increase in impact energy absorption of 100%was achieved after eight passes. Consistent results were obtained from fractography and metallography examinations of the ex-truded material during fatigue tests.

关键词： copper equal channel angular extrusion fatigue of materials grain size grain refinement fracture toughness

Impact of endoscopic ultrasound examination for deep esophageal collateral veins evaluation in liver cirrhosis patients prior to endoscopic treatment:A case series

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Portal Hypertension & Cirrhosis 2022年第1期1卷 76-81页

作者： Cosmas Rinaldi A.Lesmana saut H.Nababan Kemal F.Kalista Juferdy Kurniawan Chyntia O.M.Jasirwan Andri s.sulaiman Irsan Hasan Rino A.Gani Department of Internal Medicine Hepatobiliary DivisionDr.Cipto Mangunkusumo National General HospitalJakartaIndonesia Digestive Disease and GI Oncology Center Medistra HospitalJakartaIndonesia

Aim:The presence of esophageal collateral veins(ECV)has been reported to be associated with the recurrence of esophageal varices(EV)and bleeding in liver cirrhotic(LC)*** study aimed to see the potential clinical value of deep collateral veins assessment using endoscopic ultrasound(EUs)in liver cirrhotic patients with ***:During 6 months period,a prospective study is conducted,where we identified LC patients who were admitted for esophagogastroduodenoscopy(EGD)screening at the Department of Internal Medicine,*** Mangunkusumo National General Hospital,*** was examined using *** were excluded if they had(1)liver malignancy,(2)history of ligation or glue injection,or(3)portal or splenic vein *** collected demographic data,medical history,data pertaining to use of nonselective beta blocker(NsBB),and laboratory,imaging,and endoscopy *** was performed using a gastroscope(EG29‐i10,3.2 mm Pentax Medical)while EUs was performed using a linear array echoendoscope(EG‐3870UTK,3.8 mm,Pentax Medical)before band ligation or glue ***:There were 20 LC patients included in this study,where 15(75%)of patients were classified with Child-Pugh(CP)‐A and five(25%)of patients with CP‐*** most common aetiologies were hepatitis B in seven(35%)patients and hepatitis C in nine(45%)*** EV with peri‐or para‐esophageal veins(PEEV or PAEV)were detected in 65%of *** of the LC patients with no EV showed the presence of *** or PAEV were detected in grades 1-3 ***:EUs examination can give a better evaluation before managing gastroesophageal varices through deep ECV detection in LC patients.

关键词： endoscopic ultrasound esophageal collateral vein gastroesophageal varices liver cirrhosis portal hypertension

Innovations in endoscopic ultrasound for portal hypertension and its role in managing complications in clinical practice:Lessons learned from a tertiary referral public hospital

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Portal Hypertension & Cirrhosis 2024年第1期3卷 31-35页

作者： Cosmas R.A.Lesmana Kemal F.Kalista saut H.H.Nababan Juferdy Kurniawan Chyntia O.M.Jasirwan Andri s.sulaiman Irsan Hasan Rino A.Gani Department of Internal Medicine Hepatobiliary DivisionDr.Cipto Mangunkusumo National General HospitalMedical Faculty Universitas IndonesiaJakartaIndonesia Digestive Disease&GI Oncology Center Medistra HospitalJakartaIndonesia Gastrointestinal Cancer Center MRCCC Siloam Semanggi HospitalJakartaIndonesia

Portal hypertension(PH)poses significant *** paper presents an innovative study on the utilization of endoscopic ultrasound(EUs)for both the diagnosis and management of *** at *** Mangunkusumo National General Hospital in Jakarta,this retrospective case series included patients diagnosed with PH through clinical examination,imaging evaluation,and *** criteria comprised a history of reduced blood consumption within the last 5 days,hepatocellular carcinoma,massive ascites,or elevated international normalized ratio(>1.4).EUs-guided portal pressure gradient(PPG)measurements were performed using an innovative standard *** study involved 15 patients,with 14 having liver cirrhosis and 1 diagnosed with Budd–Chiari *** them,nine patients experienced bleeding due to gastroesophageal *** and large esophageal varices were identified in four and eight patients,*** varices type 1 were observed in two patients,and type 2 in four *** gastric fundal varices type 1 were present in one *** on EUs-PPG measurements,14 patients exhibited clinically significant portal *** patients underwent endoscopic band ligation and three underwent EUs-guided cyanoacrylate injection during the same session as the EUs-PPG measurement ***,no adverse events,such as abdominal pain,perforation,or bleeding were observed during or after the *** emerges as a promising and accurate tool for both diagnosis and management.

关键词： cyanoacrylate injection endoscopic ultrasound liver cirrhosis portal hypertension portal pressure gradient

Multi-solutions with specific geometrical wave structures to a nonlinear evolution equation in the presence of the linear superposition principle

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Communications in Theoretical Physics 2023年第1期75卷 5-14页

作者： Hajar F Ismael Tukur Abdulkadir sulaiman M s Osman Department of Mathematics Faculty of ScienceUniversity of ZakhoZakhoIraq Department of Computer Engineering Biruni UniversityIstanbulTurkey Department of Mathematics Faculty of ScienceCairo UniversityGiza 12613Egypt

Lump solutions are one of the most common solutions for nonlinear evolution *** study aspires to investigate the generalized Hietarintatype *** auspiciously provide multiple M-lump *** the other hand,collision phenomena to multiple M-lump waves with soliton wave solutions are also *** the collision,the amplitude of the lump will change significantly over the processes,whereas the amplitude of the soliton will just minimally *** it is of paramount importance,we use suitable values of parameter to put out the physical features of the reported results through three dimensional and contour *** results presented express physical features of lump and lump interaction phenomena of different kinds of nonlinear physical ***,this study serves to enrich nonlinear dynamics and provide insight into how nonlinear waves propagate.

关键词： the generalized Hietarintatype equation M-lump waves interaction phenomena hirota bilinear method

Optical solitons and modulation instability analysis of the(1+1)-dimensional coupled nonlinear schrodinger equation

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Communications in Theoretical Physics 2020年第2期72卷 17-22页

作者： Tukur Abdulkadir sulaiman Hasan Bulut Firat University Faculty of ScienceElazigTurkey Federal University DutseFaculty of ScienceJigawaNigeria Final International University Faculty of EducationKyreniaCyprus

This study successfully reveals the dark,singular solitons,periodic wave and singular periodic wave solutions of the(1+1)-dimensional coupled nonlinear schr?dinger equation by using the extended rational sine-cosine and rational sinh-cosh *** modulation instability analysis of the governing model is *** using the suitable values of the parameters involved,the 2-,3-dimensional and the contour graphs of some of the reported solutions are plotted.

关键词： the coupled nonlinear schrodinger’s equation optical soliton modulation instability

Actuator Fault Monitoring and Fault Tolerant Control in Distillation Columns

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International Journal of Automation and computing 2017年第1期14卷 80-92页

作者： sulaiman Ayobami Lawal Jie Zhang school of Chemical Engineering and Advanced Materials Newcastle University Department of Chemical Engineering University of Lagos

This paper presents, from a practical viewpoint accommodation in distillation columns. Addressing faults in an investigation of real-time actuator fault detection, propagation and industrial processes, coupled with the growing demand for higher performance, improved safety and reliability necessitates implementation of less complex alternative control strategies in the events of malfunctions in actuators, sensors and or other system components. This work demonstrates frugality in the design and implementation of fault tolerant control system by integrating fault detection and diagnosis techniques with simple active restructurable feedback controllers and with backup feedback signals and switchable reference points to accommodate actuator fault in distillation columns based on a priori assessed control structures. A multivariate statistical process monitoring based fault detection and diagnosis technique through dynamic principal components analysis is integrated with one-point control or alternative control structure for prompt and effective fault detection, isolation and accommodation. The work also investigates effects of disturbances on fault propagation and detection. specifically, the reflux and vapor boil-up control strategy used for a binary distillation column during normal operation is switched to one point control of the more valued product by utilizing the remaining healthy actuator. The proposed approach was implemented on two distillation processes： a simulated methanol-water separation column and the benchmark shell standard heavy oil fractionation process to assess its effectiveness.

关键词： Dynamic principal component analysis fault detection and diagnosis distillation column fault tolerant controller inferential control.

Evaluation of metal nanoparticles for drug delivery systems

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The Journal of Biomedical Research 2015年第2期29卷 145-149页

作者： Oluyomi s.Adeyemi Faoziyat A.sulaiman Department of Biological sciences Landmark UniversityOmu-AranKwara StateNigeria Department of Biochemistry University of IlorinIlorinNigeria

Diminazene aceturate is a trypanocide with unwanted toxicity and limited *** was reasoned that conjugating diminazene aceturate to functionalized nanoparticle would lower untoward toxicity while improving selectivity and therapeutic *** and gold nanoparticles were evaluated for their capacities to serve as carriers for diminazene *** silver and gold nanoparticles were synthesized,functionalized and coupled to diminazene aceturate following established *** nanoparticle conjugates were *** free diminazene aceturate and drug conjugated nanoparticles were subsequently evaluated for cytotoxicity in *** characterizations by transmission electron microscopy or UV/Vis spectroscopy revealed that conjugation of diminazene aceturate to silver or gold nanoparticles was *** for cytotoxic actions in vitro demonstrated no significance difference between free diminazene aceturate and the *** data suggest that surface modified metal nanoparticles could be optimized for drug delivery systems.

关键词： drugs trypanocides nanoparticles toxicity targeting

Novel pressure and displacement sensors based on carbon nanotubes

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Chinese Physics B 2015年第1期24卷 560-563页

作者： Kh.s.Karimov Khaulah sulaiman Zubair Ahmad Khakim M.Akhmedov A.Mateen GIK Institute of Engineering sciences and Technology Topi District Swabi KPK 23640 Pakistan Physical Technical Institute of Academy of sciences Rudaki Ave. 33 Dushanbe 734025 Tajikistan Low Dimensional Materials Research Centre (LDMRC) Department of Physics Faculty of Science University of Malaya 50603 Kuala Lumpur Malaysia Center for Innovative Development of science and New Technologies of Academy of sciences Rudaki Ave. 33 Dushanbe 734025 Tajikistan Faculty of Materials science and Engineering Institute of Space Technology Islamabad 44000 Pakistan

We report newly designed pressure and displacement capacitive sensors based on a flexible paper–CNT *** carbon nanotube（CNT） powder was deposited on a thin paper substrate and was pressed at an elevated *** sheet resistance of the paper–CNT films was in the range of 2–4 kΩ/cm^2. The paper–CNT films were used to fabricate pressure and displacement sensors. The sensitivities of the pressure and the displacement sensors were found to be17.3 p F·m^2/k N and 0.93 10-3p F/μm, respectively. The experimental results were compared with the simulated data and they found good agreement with each other.

关键词： carbon nanotube sensors composite capacitance