Breakdown of the continuum stokes-einstein relation for nanoparticle diffusion

Cadmium selenide nanoparticles are found to diffuse approximately 200 times faster in a polymeric liquid than predicted by the Stokes-Einstein relation. This remarkable behavior is hypothesized to be due to the nanoparticles being smaller than the entanglement mesh to create a frictional drag that does not follow continuum expectations, in line with a theoretical calculation presented before. This is one of the first demonstrations of X-ray photo correlation spectroscopy applied to polymeric liquids, which we use to explain the simultaneous 60% viscosity reduction of the mixture through a proposed constraint release mechanism.     

Confinement-Induced Phonon Softening and Hardening in Sb2Te3 Thin Films

Scaling effects in Sesqui-chalcogenides are of major interest to understand and optimize their performance in heavily scaled applications, including topological insulators and phase-change devices. A combined experimental and theoretical study is presented for molecular beam epitaxy-grown films of antimony-telluride  (Sb₂Te₃). Structural,vibrational, optical, and bonding properties upon varying confinement are studied for thicknesses ranging from 1.3 to 56 nm. In ultrathin films, the low-frequency coherent phonons of A_1g¹ symmetry are softened compared to the bulk (64.5 cm⁻¹ at 1.3 nm compared to 68 cm⁻¹ at 55.8 nm). A concomitant increase of the high-frequency A_1g² Raman mode is seen. X-ray diffraction analyses unravel an accompanying out of plane stretch by 5%, mainly stemming from an increase in the Te-Te gap. This conclusion is supported by density functional theory slab models, which reveal a significant dependency of chemical bonding on film thickness. Changes in atomic arrangement, vibrational frequencies, and bonding extend over a thickness range much larger than observed for other material classes. The finding of these unexpectedly pronounced thickness-dependent effects in quasi-2D material Sb₂Te₃ allows tuning of the film properties with thickness. The results are discussed in the context of a novel bond-type, characterized by a competition between electron localization and delocalization.     

Product feature and functionality driven integrated framework for product commercialization in presence of qualitative consumer reviews

The purpose of this research is to aid manufacturers operating in multiple market segments (characterised by a number of product variants) to formulate and synchronise their product commercialisation strategy. Product commercialisation is primarily characterised by upgrading/launching product features aimed at meeting customer’s preferences, while at the same time, enabling the enterprise to achieve its major commercial objectives. Firstly, by employing the semi-automated crowd sourcing-based approach and considering qualitative customer evaluations, customer-preferred product features have been identified and their relative weights determined. Thereafter, a detailed mixed integer quadratic programming formulation has been evolved taking into account pertinent commercial objectives of the enterprise and engineering-level constraints of the product. The developed formulation has been solved using the Branch and Cut method of commercial solver, LINGO. Detailed sensitivity analysis has been carried out, followed by populating key managerial insights. The proposed framework has been illustrated using a real-life case example of operator cabin used in heavy construction equipment industry. Our focus has been on development and illustration of devised framework; hence, the superiority of results has not been claimed. Better results may be obtained using other heuristics/algorithms.     

基于主观评价的非织造布质量客观评价方法——QualiVlies

非织造布在世界范围内广泛生产.全球标准是非织造布生产的一个竞争因素.目前,非织造布在市场中的优势不仅是价格便宜,而且质量优良.因此,为了保持非织造布的市场,有必要提高非织造布质量.在线检测系统可检测破洞、薄区、厚区等疵点,但影响非织造布质量的不仅仅是疵点,还取决于其光学均匀性.尤其对于面密度较小(如15 g/m2)的非织造布,明显的不规则纤维分布会影响顾客的主观评价.阐述了一种代表主观评价的客观图像分析方法.     

Fibre breakage during drafting on ring frame

Fibres are subjected to forces while undergoing drafting in any drafting zone. Various factors, such as fibre bulk, roller setting, roller pressure, draft, fibre length, fineness and friction between fibres, affect the magnitude of this force. It is usually considered that the drafting force in the ring frame is too low to have any consequence as far as fibre breakage is concerned. The present investigation, however, shows a substantial increase in short fibre percentage and reduction in upper quartile length, giving a clear evidence of fibre breakage during drafting process.     

Design of reliable universal QCA logic in the presence of cell deposition defect

The emergence of Quantum-dot Cellular Automata (QCA) has resulted in being identified as a promising alternative to the currently prevailing techniques of very large scale integration. QCA can provide low-power nanocircuit with high device density. Keeping aside the profound acceptance of QCA, the challenge that it is facing can be quoted as susceptibility to high error rate. The work produced in this article aims towards the design of a reliable universal logic gate (r-ULG) in QCA (r-ULG along with the single clock zone and r-ULG-II along with multiple clock zones). The design would include hybrid orientation of cells that would realise majority and minority, functions and high fault tolerance simultaneously. The characterisation of the defective behaviour of r-ULGs under different kinds of cell deposition defects is investigated. The outcomes of the investigation provide an indication that the proposed r-ULG provides a fault tolerance of 75% under single clock zone and a fault tolerance of 100% under dual clock zones. The high functional aspects of r-ULGs in the implementation of different logic functions successfully under cell deposition defects are affirmed by the experimental results. The high-level logic around the multiplexer is synthesised, which helps to extend the design capability to the higher-level circuit synthesis.     

Note on flash and distillation systems

Flash and distillation systems evolving on the equilibrium manifold possess stable steady states when the molar flows and the boundary conditions are fixed and a vapor and liquid phase is present at all times. The results extend the range of validity of a local stability theorem for linear, constant molar overflow systems due to Acrivos and Amundson. The approach to stability analysis is motivated by the tangent plane method developed by Gibbs to open systems as it takes advantage of the negative curvature of the entropy surface to construct a Lyapunov function. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3322–3332, 2013     

Evacuation infrastructure for new generating station: Options available in Indian context

Facing a deficit of 9% in power generation, India needs to harness all forms of generation including renewable energy (RE) which presently contributes less than 8% to total generation capacity. To increase the same, concerns of RE developers are being addressed by the government and regulatory bodies. One such concern is availability of transmission grid for evacuation of power. Transmission lines required for power evacuation from RE generators are typically not included in their network plan by the transmission utility. Considering the financial health and underperformance of these utilities, even if the required transmission lines are included in the network plan, RE developers are uncertain and unsure of the timely execution of the plan. Ministry of Power has earlier notified guidelines [Government of India, Ministry of Power, 2006a. Resolution on tariff based competitive-bidding guidelines for transmission service; Government of India, Ministry of Power, 2006b. Resolution on guidelines for encouraging competition in development of transmission projects] for enabling private sector participation in transmission to enable the private developers to build the required evacuation infrastructure. This paper evaluates the options available as per the legislative and regulatory framework in India through which the evacuation infrastructure for the RE projects can be built by the transmission utility or the potential investors. The key concept of “dedicated transmission line”, which has been a keenly debated and often a misunderstood issue, is also discussed in great detail.