Network-on-Chip

Addresses the Challenges Associated with System-on-Chip Integration Network-on-Chip: The Next Generation of System-on-Chip Integration examines the current issues restricting chip-on-chip communication efficiency, and explores Network-on-chip (NoC), a promising alternative that equips designers with the capability to produce a scalable, reusable, and high-performance communication backbone by allowing for the integration of a large number of cores on a single system-on-chip (SoC). This book provides a basic overview of topics associated with NoC-based design: communication infrastructure design, communication methodology, evaluation framework, and mapping of applications onto NoC. It details the design and evaluation of different proposed NoC structures, low-power techniques, signal integrity and reliability issues, application mapping, testing, and future trends. Utilizing examples of chips that have been implemented in industry and academia, this text presents the full architectural design of components verified through implementation in industrial CAD tools. It describes NoC research and developments, incorporates theoretical proofs strengthening the analysis procedures, and includes algorithms used in NoC design and synthesis. In addition, it considers other upcoming NoC issues, such as low-power NoC design, signal integrity issues, NoC testing, reconfiguration, synthesis, and 3-D NoC design. This text comprises 12 chapters and covers: The evolution of NoC from SoC—its research and developmental challenges NoC protocols, elaborating flow control, available network topologies, routing mechanisms, fault tolerance, quality-of-service support, and the design of network interfaces The router design strategies followed in NoCs The evaluation mechanism of NoC architectures The application mapping strategies followed in NoCs Low-power design techniques specifically followed in NoCs The signal integrity and reliability issues of NoC The details of NoC testing strategies reported so far The problem of synthesizing application-specific NoCs Reconfigurable NoC design issues Direction of future research and development in the field of NoC Network-on-Chip: The Next Generation of System-on-Chip Integration covers the basic topics, technology, and future trends relevant to NoC-based design, and can be used by engineers, students, and researchers and other industry professionals interested in computer architecture, embedded systems, and parallel/distributed systems

INVESTIGATION OF FLOW AND MICROSTRUCTURE IN RHEOMETRIC AND PROCESSING FLOW CONDITIONS FOR LIQUID CRYSTALLINE PITCH

A fundamental understanding of flow and its influence on the microstructure is required to obtain carbon materials with desired properties. The objective of this research was to investigate the flow and microstructural behavior of a synthetic mesophase pitch (AR-HP) in rheometric and processing flow conditions. In addition, simulation studies were performed to establish a frame work for modeling the flow behavior of this complex material in different flow situations. The steady-shear viscosities obtained from a cone-plate rheometer during increasing rate-sweep experiments exhibited a shear-thinning region (Region I) with a slope of about -0.2 and a plateau (Region II) region. The transient shear stress responses, as measured from cone-plate rheometer, exhibited nonmonotonic behavior as a function of applied strain at all shear rates and temperatures tested. Microstructural study on three orthogonal sections of the sheared samples, reported for the first time, indicates that the local maximum in shear stress was due to yielding of initial microstructure. In addition to high-strain experiments, dynamic experiments were also performed in the linear viscoelastic region. The elastic response was found to be strongly dependent on the microstructure, and a lower slope of 0.8 for the elastic modulus in the low-frequency terminal region was observed as compared to 2 observed for flexible-chain polymers. Relaxation of microstructure was found to be influenced not only by the textural size, but also by layer-plane orientation. The flow-microstructural study was extended to the processing flow conditions by extruding AR-HP mesophase pitch through custom-made dies. Microstructural observations suggest that in the capillary, the orientation of the layer-plane was approximately radial near the wall and the orientation deviated from the radial orientation away from the wall. In the core, no preferred orientation of mesophase layer-planes was observed. Simulation studies were performed using constitutive equations for discotic liquid-crystalline materials in simple shear flow, corresponding with the experimental studies. Two different initial conditions were considered that resemble the experimental results. At steady state, the bulk of the discs were found to be oriented at a flow-aligned angle of -64.1°, which is consistent with the theoretical predictions

Unilateral variation in the position of internal and external carotid arteries

During the routine dissection of the neck region of a 77 years old male cadaver in the Department of Anatomy at Bankura Sammilani Medical College, a unilateral variation in the position and course of internal and external carotid arteries was noticed on the right side of neck. The internal carotid artery was anteromedial to the external carotid artery at the site of bifurcation of the common carotid artery. Knowledge of variation in the course and relation of internal and external carotid arteries is important for surgeons to perform neck surgery and also for the radiologists to interpret carotid system imaging

Age associated oxidative damage in lymphocytes

Lymphocytes are an important immunological cell and have been played a significant role in acquired immune system; hence, may play in pivotal role in immunosenescence. Oxidative stress has been reported to increase in elderly subjects, possibly arising from an uncontrolled production of free radicals with aging and decreased antioxidant defenses. This study was aimed to evaluate the level of lipid-protein damage and antioxidant status in lymphocytes of healthy individuals to correlate between oxidative damage with the aging process. Twenty healthy individuals of each age group (11–20; 21–30; 31–40; 41–50; and 51–60 years) were selected randomly. Blood samples were drawn by medical practitioner and lymphocytes were isolated from blood samples. Malondialdehyde (MDA), protein carbonyls (PC) level were evaluated to determine the lipid and protein damage in lymphocytes. Superoxide dismutase (SOD), catalase (CAT), glutathione and glutathione dependent enzymes were estimated to evaluate the antioxidant status in the lymphocytes. Increased MDA and PC levels strongly support the increased oxidative damage in elderly subject than young subjects. The results indicated that, balance of oxidant and antioxidant systems in lymphocytes shifts in favor of accelerated oxidative damage during aging. Thus oxidative stress in lymphocytes may particular interest in aging and may play important role in immunosenescence

Magnetic frustration driven by conduction carrier blocking in Nd2_2Co0.85_{0.85}Si2.88_{2.88}

The intermetallic compound Nd$_2$Co$_{0.85}$Si$_{2.88}$ having a triangular lattice could be synthesized in single-phase only with defect crystal structure. Investigation through different experimental techniques indicate the presence of two magnetic transitions in the system. As verified experimentally and theoretically, the high-temperature transition T$_H$ ~ 140 K is associated with the development of ferromagnetic interaction between itinerant Co moments, whereas the low-temperature transition at T$_L$ ~ 6.5 K is due to the coupling among Nd-4f and Co-3d moments, which is antiferromagnetic in nature. Detailed studies of temperature-dependent dc magnetic susceptibility, field dependence of isothermal magnetization, non-equilibrium dynamical behavior, viz. magnetic relaxation, aging effect, magnetic-memory effect, and temperature dependence of heat capacity, along with density functional theory (DFT) calculations, suggest that the ground state is magnetically frustrated spin-glass in nature, having competing magnetic interactions of equivalent energies. DFT results further reveal that the 3d/5d-conduction carriers are blocked in the system and act as a barrier for the 4f-4f RKKY interactions, resulting in spin-frustration. Presence of vacancy defects in the crystal are also conducive to the spin-frustration. This is an unique mechanism of magnetic frustration, not emphasized so far in any of the ternary R$_2$TX$_3$ (R=rare-earth, T=transition elements and X=Si, Ge, In) type compounds. Due to the competing character of the itinerant 3d and localized 4f moments, the compound exhibits anomalous field dependence of magnetic coercivity.Comment: 16 pages, 15 figure

Exploring grindability of Ti-6Al-4V using an indigenously developed environment friendly micro pump based cooling system

724-729Titanium alloys are ideally suited for different manufacturing applications because of their unique combination of high specific strength over a wide range of temperature, in addition to excellent corrosion resistance properties. However, grinding of titanium alloys is quite difficult due to their high hardness at elevated temperature, low thermal conductivity and elastic modulus. Application of cutting fluid helps to improve grindability, but with the increasing level of environmental consciousness, new technologies have been required to address the problem. This investigation deals with application of alkaline soap water through an indigenously developed micro pump based cooling system during grinding of Ti-6Al-4V. Comparison has been made with dry grinding with respect to some response parameters such as grinding forces, specific energy, surface roughness, grinding chips and ground surface morphology. Results have indicated that grinding forces, specific energy requirement and surface roughness decrease with the application of the micro pump based system. Observation of grinding ratio, chip form and ground surface has shown favourable results. Therefore, this newly developed micro pump system may be recommended to supply soap water for grinding titanium alloys

Exploring grindability of Ti-6Al-4V using an indigenously developed environment friendly micro pump based cooling system

Titanium alloys are ideally suited for different manufacturing applications because of their unique combination of highspecific strength over a wide range of temperature, in addition to excellent corrosion resistance properties. However,grinding of titanium alloys is quite difficult due to their high hardness at elevated temperature, low thermal conductivity andelastic modulus. Application of cutting fluid helps to improve grindability, but with the increasing level of environmentalconsciousness, new technologies have been required to address the problem. This investigation deals with application ofalkaline soap water through an indigenously developed micro pump based cooling system during grinding of Ti-6Al-4V.Comparison has been made with dry grinding with respect to some response parameters such as grinding forces, specificenergy, surface roughness, grinding chips and ground surface morphology. Results have indicated that grinding forces,specific energy requirement and surface roughness decrease with the application of the micro pump based system.Observation of grinding ratio, chip form and ground surface has shown favourable results. Therefore, this newly developedmicro pump system may be recommended to supply soap water for grinding titanium alloys

Electronic and magnetic properties of the topological semimetal SmMg2_2Bi2_2

Dirac semimetals show nontrivial physical properties and can host exotic quantum states like Weyl semimetals and topological insulators under suitable external conditions. Here, by combining angle-resolved photoemission spectroscopy measurements (ARPES) and first-principle calculations, we demonstrate that Zintl-phase compound SmMg$_2$Bi$_2$ belongs to the close proximity to a topological Dirac semimetallic state. ARPES results show a Dirac-like band crossing at the zone-center near the Fermi level ($E_\mathrm {F}$) which is further confirmed by first-principle calculations. Theoretical studies also reveal that SmMg$_2$Bi$_2$ belongs to a $Z_2$ topological class and hosts spin-polarized states around the $E_\mathrm {F}$. Zintl's theory predicts that the valence state of Sm in this material should be Sm$^{2+}$, however we detect many Sm-4$f$ multiplet states (flat-bands) whose energy positions suggest the presence of both Sm$^{2+}$ and Sm$^{3+}$. It is also evident that these flat-bands and other dispersive states are strongly hybridized when they cross each other. Due to the presence of Sm$^{3+}$ ions, the temperature dependence of magnetic susceptibility $\chi(T)$ shows Curie-Weiss-like contribution in the low temperature region, in addition to the Van Vleck-like behaviour expected for the Sm$^{2+}$ ions. The present study will help in better understanding of the electronic structure, magnetism and transport properties of related materials.Comment: 10 pages, 7 figure

Anisotropic magnetism and electronic structure of trigonal EuAl2_2Ge2_2 single crystals

The magnetic and electronic properties of the layered Zintl-phase compound EuAl$_2$Ge$_2$ crystallizing in the trigonal CaAl$_2$Si$_2$-type structure are reported. Our neutron-diffraction measurements show that EuAl$_2$Ge$_2$ undergoes A-type antiferromagnetic (AFM) ordering below $T_{\rm N} = 27.5(5)$~K, with the Eu moments (Eu$^{2+}$, $S = 7/2$) aligned ferromagnetically in the $ab$ plane. The $H = 0$ magnetic structure consists of trigonal AFM domains associated with $ab$-plane magnetic anisotropy and a field-induced reorientation of the Eu spins in the domains is evident at $T = 2$~K below the critical field $H_{c1} = 2.5(1)$ kOe. Electrical resistivity and ARPES measurements show that EuAl$_2$Ge$_2$ is metallic both above and below $T_{\rm N}$. In the AFM phase, we directly observe folded bands in ARPES due to the doubling of the magnetic unit cell along the $c$ axis with an enhancement of quasiparticle weight due to the complex change in the coupling between the magnetic moments and itinerant electrons on cooling below $T_{\rm N}$. The observed electronic structure is well reproduced by first-principle calculations, which also predict the presence of nontrivial electronic states near the Fermi level in the AFM phase with $Z_2$ topological numbers 1;(000).Comment: 16 pages, 13 captioned figures, 53 references Updated several affiliation