Indian Institute of Technology Hyderabad
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Smart manufacturing systems for industry 4.0
No full textManufacturing industries have evolved from using of steam power for mechanization to using of electricity in the past two industrial revolutions. The third industrial revolution was brought about with the application of information technology in manufacturing. Now, it has reached the fourth industrial revolution or Industry 4.0 which is built on inter-connectivity. Smart manufacturing systems play an integral role in moving towards Industry 4.0. The aim of this chapter is to discuss the technologies which supports and contributes to smart manufacturing and to understand its characteristics. Because of the benefits of smart manufacturing, it has attracted various professionals to apply smart manufacturing in their own fields. In this chapter, the applications of smart manufacturing are presented especially in industrial and mechanical engineering. The challenges faced by the industry while implementing smart manufacturing systems has also been mentioned
Field angle dependent resonant dynamics of artificial spin ice lattices
No full textArtificial spin ice structures which are networks of coupled nanomagnets arranged on different lattices that exhibit a number of interesting phenomena are promising for future information processing. We report reconfigurable microwave properties in artificial spin ice structures with three different lattice symmetries namely square, kagome, and triangle. Magnetization dynamics are systematically investigated using field angle dependent ferromagnetic resonance spectroscopy. Two distinct ferromagnetic resonance modes are observed in square spin ice structures in contrast with the three well-separated modes in kagome and triangular spin ice structures that are spatially localized at the center of the individual nanomagnets. A simple rotation of the sample placed in magnetic field results in the merging and splitting of the modes due to the different orientations of the nanomagnets with respect to the applied magnetic field. Magnetostatic interactions are found to shift the mode positions after comparing the microwave responses from the array of nanomagnets with control simulations with isolated nanomagnets. Moreover, the extent of the mode splitting has been studied by varying the thickness of the lattice structures. The results have potential implications for microwave filter-type applications which can be operated for a wide range of frequencies with ease of tunability
Large Eddy Simulation Study of Atmospheric Boundary Layer Flow over an Abrupt Rough-to-Smooth Surface Roughness Transition
Full text linkThe atmospheric boundary layer flow downstream of an abrupt rough-to-smooth surface roughness transition is studied using large eddy simulations (LES) for a range of surface roughness ratios. Standard wall models assume horizontal homogeneity and are inapplicable for heterogeneous surfaces. Two heterogeneous-surface wall models are evaluated, one based on a local application of similarity theory using a twice-filtered velocity field (BZ model) and another based on a local friction-velocity obtained by blending the upstream and downstream profiles (APA model). The wall shear stress and the turbulence intensity (TI) are sensitive to the wall model while the mean streamwise velocity and the total shear stress (TSS) are less sensitive. The APA model is more accurate than the BZ model on comparison to previous experiments. The wall shear stress obtained using the APA wall model is sensitive to the ratio of the equilibrium and the internal boundary layer (IBL) heights, while other statistics are not. The IBL height is insensitive to the turbulent quantity (TSS or TI) on which it is based. Several analytical relations for the IBL height are evaluated using the LES data. Two models are found to be accurate for different roughness ratios while one model is reasonable over the full range investigated. A phenomenological model is developed for the TI downstream of the roughness jump using a weighted average of the upstream and far-downstream profiles. The model yields reasonable predictions for all roughness ratios investigated
Toward Performance Improvement of a Baculovirus–Insect Cell System under Uncertain Environment: A Robust Multiobjective Dynamic Optimization Approach for Semibatch Suspension Culture
Full text linkThe baculovirus expression vector system (BEVS) is one of the well-known versatile platforms for the recombinant protein/vaccine production. Mathematical modeling and optimization of a baculovirus-insect cell system can have significant industrial relevance as this reduces the number of expensive experiments and time involved in the experiment-based optimization. However, modeling and control of such a nonlinear system remains challenging due to the presence of uncertainties in the model. In this context, we propose a novel computational framework combining the principles of systems biology and dynamic optimization under uncertainty for optimizing a semibatch baculovirus-insect cell system. Toward this, first, a mathematical model replicating the dynamic experimental data on cell and virus growth was identified. Next, the proposed model was used for deterministic multiobjective dynamic optimization of the control variables, substrate, and multiplicity of infection (MOI) to achieve the conflicting objectives of productivity maximization and substrate minimization, simultaneously. Finally, based on the sensitivity analysis, six of the most influential parameters depicting model uncertainties have been considered for the robust multiobjective optimal control of the system. A comprehensive comparison displays up to 114% and 76% increases in the cell densities for the deterministic and stochastic semibatch processes, respectively, compared to the batch process. Semibatch operation also favors a minimum 40% reduction in MOI required to achieve the same level of infected cell density compared to the batch operation. This study provides a generic methodology for exhibiting a proof of concept that a semibatch suspension culture considering uncertainty in model parameters can give better productivity compared to a batch suspension culture for a BEVS
Voltage-Gated T-Type Calcium Channel Modulation by Kinases and Phosphatases: The Old Ones, the New Ones, and the Missing Ones
Full text linkCalcium (Ca2+) can regulate a wide variety of cellular fates, such as proliferation, apoptosis, and autophagy. More importantly, changes in the intracellular Ca2+ level can modulate signaling pathways that control a broad range of physiological as well as pathological cellular events, including those important to cellular excitability, cell cycle, gene-transcription, contraction, cancer progression, etc. Not only intracellular Ca2+ level but the distribution of Ca2+ in the intracellular compartments is also a highly regulated process. For this Ca2+ homeostasis, numerous Ca2+ chelating, storage, and transport mechanisms are required. There are also specialized proteins that are responsible for buffering and transport of Ca2+. T-type Ca2+ channels (TTCCs) are one of those specialized proteins which play a key role in the signal transduction of many excitable and non-excitable cell types. TTCCs are low-voltage activated channels that belong to the family of voltage-gated Ca2+ channels. Over decades, multiple kinases and phosphatases have been shown to modulate the activity of TTCCs, thus playing an indirect role in maintaining cellular physiology. In this review, we provide information on the kinase and phosphatase modulation of TTCC isoforms Cav3.1, Cav3.2, and Cav3.3, which are mostly described for roles unrelated to cellular excitability. We also describe possible potential modulations that are yet to be explored. For example, both mitogen-activated protein kinase and citron kinase show affinity for different TTCC isoforms; however, the effect of such interaction on TTCC current/kinetics has not been studied yet
Optimizing anion storage performances of graphite/ non-graphitic carbon composites as cathodes for dual-ion batteries
Full text linkAnion intercalation capacity of graphite cathode is a limiting factor towards the development of dual-ion energy storage devices. A large portion of electrochemically active sites in graphite lattice remains inaccessible to anions due to the instability of electrolytes beyond 5 V. Strategy to composite graphitic intercalation along with surface storage from non-graphitic carbons to enhance capacity is explored in this work. Optimizations are performed to determine the best ratio of graphitic and non-graphitic carbons, and to find out the blend of physical properties of non-graphitic carbons that aid the surface contribution to the greatest extent. Besides, it is also optimized to obtain the maximum achievable lifetime and efficiency, suitable active material loading for balancing energy-power output, and the safest upper cut-off voltage for trading off capacity against cycle life. Surface area, pore size, functional groups, and doped elements govern the electrochemical properties of non-graphitic carbons. A composite of graphite with high surface area carbon (2477 m2 g − 1) in a 75:25 ratio doubles the capacity, whereas the composite of graphite and reduced graphene oxide at the same ratio yields prolonged cycle life at 100 mA g − 1 within 2.0–5.0 V. The capacity improvement is invariably reproducible in dual carbon cell using composite materials as both electrodes
Interplay of nonlocality and incompatibility breaking qubit channels
Full text linkIncompatibility and nonlocality are not only of foundational interest but also act as important resources for quantum information theory. In the Clauser-Horne-Shimony-Holt (CHSH) scenario, the incompatibility of a pair of observables is known to be equivalent to Bell nonlocality. Here, we investigate these notions in the context of qubit channels. The Bell-CHSH inequality has a greater perspective - compared to any genuine tripartite nonlocality scenario - while determining the interplay between nonlocality breaking qubit channels and incompatibility breaking qubit channels. In the Bell-CHSH scenario, we prove that if the conjugate of a channel is incompatibility breaking, then the channel is itself nonlocality breaking and vice versa. However, this equivalence is not straightforwardly generalized to multipartite systems, due to the absence of an equivalence relation between incompatibility and nonlocality in the multipartite scenario. We investigate this relation in the tripartite scenario by considering some well-known states like Greenberger-Horne-Zeilinger and W states and using the notion of Mermin and Svetlichny nonlocality. By subjecting the parties in question to unital qubit channels, we identify the range of state and channel parameters for which incompatibility coexists with nonlocality. Further, we identify the set of unital qubit channels that is Mermin or Svetlichny nonlocality breaking irrespective of the input state
Design and performance characteristics of cement grouted bituminous mixtures - a review
Full text linkCement grouted bituminous mix (CGBM) is a composite type of pavement surfacing prepared by injecting cementitious grouting material in porous asphalt mixtures under the effect of gravity. Over the past few decades, CGBM is gaining attention due to its numerous advantages over flexible and rigid pavement. Several researchers conducted various laboratory and field studies on CGB mixes using different grouting materials. A comprehensive review of the aggregate gradation, binder type, composition of grouting materials, their effect on the mechanical properties and performance characteristics of CGB mixes, micro-mechanical analysis of CGBM, effect of reclaimed asphalt pavement (RAP) on CGBM are summarized
Generation of continuous T-norms through latticial operations
Full text linkIt is well known that the usual point-wise ordering over the set T of t-norms makes it a poset but not a lattice, i.e., the point-wise maximum or minimum of two t-norms need not always be a t-norm again. In this work, we propose, two binary operations [Formula presented] on the set TCA of continuous Archimedean t-norms and obtain, via these binary operations, a partial order relation ⊑, different from the usual point-wise order ≤, on the set TCA. As an interesting outcome of this structure, some stronger versions of some existing results dealing with the upper and lower bounds of two continuous Archimedean t-norms with respect to the point-wise order ≤ are also obtained. Finally, with the help of the operations [Formula presented] on the set TCA, two binary operations ⊕,⊗ on the set TC of continuous t-norms are proposed and showed that (TC,⊕,⊗) is a lattice. Thus we have both a way of generating continuous t-norms from continuous t-norms and also obtain an order on them
Effect of molybdenum on recrystallization behavior of Fe30Mn5Al1C- x Mo lightweight austenitic steels
Full text linkLightweight austenitic steels are among the materials of interest which can potentially reduce the CO2 emissions and improve the fuel efficiency in automotive sector. Understanding the recrystallization behavior of these steels would open the door for a spectrum of structural applications that need a strength-ductility balance. In the present work, the recrystallization behavior of cold rolled Fe-30Mn-5Al-1C- (0–3 wt%) Mo austenitic steels after annealing at 600–1200 °C was investigated through EBSD, FESEM, TEM and hardness. The solubility of molybdenum in austenite and the equilibrium phases is determined through thermodynamic calculations. Alloying with more than 0.5 wt% Mo increased the recrystallization temperature by ∼ 100 °C. M2C type carbides precipitated in 2-Mo and 3-Mo alloys leading to grain refinement and delay in recrystallization. The hardness increased with increase in Mo content and decreased with increase in annealing temperature. At 1200 °C, due to grain growth all the alloys have similar grain size and hardness