Practical solutions for sampling alternatives in large-scale models

Many large-scale real-world transport applications have choice sets that are so large as to make model estimation and application computationally impractical. The ability to estimate models on subsets of the alternatives is thus of great appeal, and correction approaches have existed since the late 1970s for the simple multinomial logit (MNL) model. However, many of these models in practice rely on nested logit specifications, for example, in the context of the joint choice of mode and destination. Recent research has put forward solutions for such generalized extreme value (GEV) structures, but these structures remain difficult to apply in practice. This paper puts forward a simplification of the GEV method for use in computationally efficient implementations of nested logit. The good performance of this approach is illustrated with simulated data, and additional insights into sampling error are also provided with different sampling strategies for MNL

Effect of Polypropylene fibres on the Workability parameters of Extrudable Cementitious Material

Additive manufacturing in construction industry has been introduced as an aspiration for a more sustainable built environment and currently evolving with high demand amongst researches. This study is an investigation of the influence of polypropylene (PP) fibre addition on the workability parameters of a new extrudable concrete mixture. As the quality of final printed structure prominently depends on the fresh state properties of concrete, this investigation mainly focused on the rheological properties such as workability (flow), setting time, extrudability and buildability. These parameters were systematically investigated through a small scale experimental process with time after mixing. The selected control mix with Ground granulated blast furnace slag (GGBS) and Silica Fume (SF) was used in this analysis. The Control cementitious specimens without fibre inclusion and with fibre addition in different volume fraction of binder, ranging from 0.5% to 3% were printed. The results showed that the fibre addition of 0, 0.5 and 1.0% have the better flowability and extrudability compared to 1.5, 2 and 3%. Also, reduction in the print quality was assessed visually with increasing fibre percentage. However, results indicated that the initial setting time is comparatively low for those mixes with higher fibre inclusion which is required for better bond strength between layers. Moreover, higher fibre content caused better buildability and shape retention in the extruded samples

Si Based Mis Devices with Ferroelectric Polymer Films for Non-Volatile Memory Applications

Ferroelectric non-volatile memories have gained momentous importance in the recent years. Significant research is being done on different device structures with several ferroelectric films for better data retention, lower power dissipation and higher density of integration. Metal - ferroelectric insulator – semiconductor (MIS) capacitor structures with Poly Vinylidene Fluoride(80%) - trifluoroethylene (20%) (PVDF – TrFE) copolymer are observed to demonstrate consistent dielectric properties and retainable memory action under selected operating conditions. Prior research was done on devices with MFeOS structure with an oxide buffer layer. The presence of a buffer oxide reduces the field acting on the film for memory state switching, which in effect requires the devices to be operated at higher voltages. In this work, MFeS devices with lower ferroelectric film thickness; with, and without a very thin buffer oxide have been studied. The dielectric behavior of PVDF thin film, when deposited directly on Si, is observed to exhibit reliable memory properties without significant charge injection under certain operating conditions. Electrical characteristics such as capacitance-voltage(C-V) and polarization-electric field (P-E) hysteresis with the direction of measurement and conduction properties through the junction have been comprehensively studied to establish the behavior of the MIS device for possible use in MIS FETs for high density ferroelectric memories

Tumor associated carbonic anhydrase inhibitors: Rational approaches, design strategies, structure activity relationship and mechanistic insights

The emergence of tumor-associated human carbonic anhydrases (hCA) as promising therapeutic targets has urged rigorous research into the development of potent and selective hCA IX and XII inhibitors. Rationalization of targeting tumor-specific hCA isoforms is a major challenge that requires a comprehensive understanding of the interactions between inhibitors and the dynamic hCA active site. The benzenesulfonamides and its bioisosteres are currently being used clinically as inhibitors of various hCA isoforms through classical inhibitory mechanism. In addition, several other chemotypes have also been developed with improved potency and selectivity through non-classical inhibitory mechanisms. Coumarin and its derivatives represent highly selective and potent inhibitors of hCA IX and XII. Recently, various other pharmacophores were also proven to have a strong selectivity and potency against hCA IX and XII including pyrazole, 1,2,3-triazole, 4-thiazolidinone, and thiourea. This review navigates through understanding the role of hCA IX and XII in cancer biology, encompassing different inhibition approaches, strategic design methodologies, recent advancements in the rational design of hCA inhibitors, exploration of structure-activity relationships, in-depth mechanistic insights, and PET imaging applications for in vivo visualization of target enzymes

Utilization of wrightia tinctoria nano seed fibers as a reinforcement in the preparation of epoxy-based composites

Natural seed fiber reinforced composite materials are replacing many conventional ones because of their excellent properties, less weight, easy availability, etc. Composite materials are used in many areas because of their superior features. Mechanical property is one of the vital parameters for choosing the material. The current investigation has revealed an importance of recently well-known Wrightia tinctoria nano seed fibers (WTNSFs), which are extracted physically. Wrightia tinctoria nano seed fiber reinforced composite was prepared with the epoxy resin by hand layup method. Epoxy resin is easy to handle and available at low cost. Mechanical tests are conducted reinforced composites of plain epoxy and WTNSFs to obtain strength properties like tensile, flexural, impact. Water absorption tests also performed on composites. Here, the developed composites are easy to handle, offered economically, and used primarily in marine applications due to less water absorption and good wax content. A comprehensive description of different tests and the properties of WTNSFs are studied and compared with the other existing natural fibers. This work showed that 35% combination of WTNSFs reinforced epoxy matrix offers enhanced mechanical properties with minimum water absorption compared with plain epoxy composites