http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Nadeem Qaiser (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Numerical Modeling of Fracture-Resistant Sn Micropillars as Anode for Lithium Ion Batteries
Qaiser, Nadeem,Kim, Yong Jae,Hong, Chung Su,Han, Seung Min American Chemical Society 2016 The Journal of Physical Chemistry Part C Vol.120 No.13
<P>Sn possesses three times higher capacity in comparison to graphite anode (372 mAhg(-1)) that makes it a promising candidate for enhanced performance Li ion batteries. Contrary to Si, Sn is compliant and ductile in nature and thus is expected to readily relax the Li diffusion-induced stresses. The low melting point of Sn additionally allows for stress relaxations from time-dependent or creep deformations even at room temperature. In this study, numerical modeling is used to reveal the significance of plasticity and creep-based stress relaxations in the Sn working electrode. The maximum elastic tensile hoop stresses for 1 mu m micropillar size with 1C charging rate conditions reduces down from similar to 1 GPa to similar to 200 MPa when Sn is allowed to plastically deform at a yield strength of similar to 150 MPa. After experimentally determining the creep response of Sn micropillars, creep deformations are incorporated in numerical modeling to show that the maximum tensile hoop stress is further reduced to similar to 0.45 MPa under the same conditions. Lastly, the Li-induced stresses are analyzed for different micropillar sizes to evaluate the critical size to prevent fracture, which is determined to be similar to 5.3 mu m for C/10 charging rate, which is significantly larger than that in Si.</P>
-
Nadeem Qaiser,Naeem Iqbal,Amir Hussain,Naeem Qaiser 대한전기학회 2007 International Journal of Control, Automation, and Vol.5 No.5
This paper proposes a simpler solution to the stabilization problem of a special class of nonlinear underactuated mechanical systems which includes widely studied benchmark systems like Inertia Wheel Pendulum, TORA and Acrobot. Complex internal dynamics and lack of exact feedback linearizibility of these systems makes design of control law a challenging task. Stabilization of these systems has been achieved using Energy Shaping and damping injection and Backstepping technique. Former results in hybrid or switching architectures that make stability analysis complicated whereas use of backstepping some times requires closed form explicit solutions of highly nonlinear equations resulting from partial feedback linearization. It also exhibits the phenomenon of explosions of terms resulting in a highly complicated control law. Exploiting recently introduced Dynamic Surface Control technique and using control Lyapunov function method, a novel nonlinear controller design is presented as a solution to these problems. The stability of the closed loop system is analyzed by exploiting its two-time scale nature and applying concepts from Singular Perturbation Theory. The design procedure is shown to be simpler and more intuitive than existing designs. Design has been applied to important benchmark systems belonging to the class demonstrating controller design simplicity. Advantages over conventional Energy Shaping and Backstepping controllers are analyzed theoretically and performance is verified using numerical simulations.
-
Adeel Ikram,Nadeem Ahmad Mufti1,Muhammad Qaiser Saleem,Ahmed Raza Khan 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.7
This paper reports the effect and optimization of eight control factors on material removal rate (MRR), surface roughness and kerf in wire electrical discharge machining (WEDM) process for tool steel D2. The experimentation is performed under different cutting conditions of wire feed velocity, dielectric pressure, pulse on-time, pulse off-time, open voltage, wire tension and servo voltage by varying the material thickness. Taguchi’s L18 orthogonal array is employed for experimental design. Analysis of variance (ANOVA) and signal-tonoise (S/N) ratio are used as statistical analyses to identify the significant control factors and to achieve optimum levels respectively. Additionally, linear regression and additive models are developed for surface roughness, kerf and material removal rate (MRR). Results of the confirmatory experiments are found to be in good agreement with those predicted. It has been found that pulse on-time is the most significant factor affecting the surface roughness, kerf and material removal rate.
-
A review of carbon-based materials and their coating techniques for biomedical implants applications
Hassan Sadia,Nadeem Aroosa Younis,Qaiser Hafsah,Kashif Amer Sohail,Ahmed Ammad,Khan Khushbukhat,Altaf Amna 한국탄소학회 2023 Carbon Letters Vol.33 No.4
Carbon-based materials have emerged as an excellent class of biomedical materials due to their exceptional mechanical properties, lower surface friction, and resistance to wear, tear, and corrosion. Experimental studies have shown the promising results of carbon-based coatings in the field of biomedical implants. The reasons for their successful applications are their ability to suppress thrombo-inflammatory reactions which are evoked as an immune response due to foreign body object implantation. Different types of carbon coatings such as diamond-like carbon, pyrolytic carbon, silicon carbide, and graphene have been extensively studied and utilized in various fields of life including the biomedical industry. Their atomic arrangement and structural properties give rise to unique features which make them suitable for multiple applications. Due to the specificity and hardness of carbon-based precursors, only a specific type of coating technique may be utilized for nanostructure development and fabrication. In this paper, different coating techniques are discussed which were selected based on the substrate material, the type of implant, and the thickness of coating layer. Chemical vapor deposition-based techniques, thermal spray coating, pulsed laser deposition, and biomimetic coatings are some of the most common techniques that are used in the field of biomaterials to deposit a coating layer on the implant. Literature gathered in this review has significance in the field of biomedical implant industry to reduce its failure rate by making surfaces inert, decreasing corrosion related issues and enhancing biocompatibility.
DBpia연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
