Automated Semantic Analysis of Schematic Data

Content in numerous Web data sources, designed primarily for human consumption, are not directly amenable to machine processing. Automated semantic analysis of such content facilitates their transformation into machine-processable and richly structured semantically annotated data. This paper describes a learning-based technique for semantic analysis of schematic data which are characterized by being template-generated from backend databases. Starting with a seed set of hand-labeled instances of semantic concepts in a set of Web pages, the technique learns statistical models of these concepts using light-weight content features. These models direct the annotation of diverse Web pages possessing similar content semantics. The principles behind the technique find application in information retrieval and extraction problems. Focused Web browsing activities require only selective fragments of particular Web pages but are often performed using bookmarks which fetch the contents of the entire page. This results in information overload for users of constrained interaction modality devices such as small-screen handheld devices. Fine-grained information extraction from Web pages, which are typically performed using page specific and syntactic expressions known as wrappers, suffer from lack of scalability and robustness. We report on the application of our technique in developing semantic bookmarks for retrieving targeted browsing content and semantic wrappers for robust and scalable information extraction from Web pages sharing a semantic domain. This work has been conducted while the author was at Stony Brook University.     

Electro-kinetically enhanced mass transport of charged macro-solutes through a microchannel with porous walls

Electrokinetics of the solute transport across the porous walls of micro channel is important from its practical application but less explored. Transport of the charged macro-solutes across perm-selective walls in a microchannel is investigated. The extended Nernst–Planck equation describes the charged macro-solutes distribution in the mass transfer boundary layer over the porous wall. The transverse electromigration of the charged macro-solute either augments or suppresses the concentration polarization and the permeation rate depending on the wall and solute surface potential (attractive or repelling). The wall potential is screened due to the electrical double layer interaction of the wall and charged solute. It is observed that the charged solute concentration over the channel wall enhances by two times in case of oppositely charged interactions (unlike solute and channel wall) compared to like charges. The findings of this study can facilitate understanding of electrokinetic based drug delivery and separation systems involving charged solutes.     

Droplet splitting in multi-furcating microchannel: A three-dimensional numerical simulation study

This work investigates the splitting of a droplet in a multi-furcating microfluidic channel for a two-phase system employing 3D simulation. The simulations were performed using an explicit volume of fluid (VOF) method and have been validated using experimental data taken from the literature. The width ratio of the branch channel to the main channel is set to 0.25 for five branches of the multi-furcating microchannel, as it is the width ratio at which multiple splitting takes place. Simulations have been carried out at different oil velocities (V_o) ranging from 0.12 to 0.22 m/s and at different water velocities (V_w) ranging from 0.002 to 0.10 m/s. Oil fraction data in the main channel has been recorded and compared with the homogenous model. The average difference between the homogeneous model and the 3D simulations is 22.68%. Analysis of dimensionless droplet length in ±0°, ± 40°, and 90° branch channels has been done. α (length of the droplet in branch channel/width of the main channel) increases up to a flow rate ratio of 0.38, and then decreases, whereas β (length of the droplet in the main channel/width of the main channel) increases with an increase in flow rate ratio. A flow pattern map has been developed to identify the various droplet breakup regimes at the junction. Frequency (counts per unit time) of droplet generation increases with capillary number for all the branch channels except for the 0° branch channel, where the regime is that the droplet passes through three branch channels. The volume distribution ratio (λ) decreases at first, then increases with an increase in capillary number for 0°:90° and 40°:90° angle branch channels for the regime where the droplet passes through five branch channels. For the regime where the droplet passes through three branch channels, the trend is likely linear with λ = 0.3 ± 0.04. The dimensionless mother droplet length increases with an increase in capillary number for V_o = 0.13 and 0.16 m/s, but for V_o = 0.19 and 0.22 m/s, the dimensionless mother droplet length becomes constant after capillary number = 0.26 and 0.30 respectively. The droplet breakup time (t) for regime (a), where the droplet passes through three branch channels, is 0.002 s; for regime (b), where the droplet passes through five branch channels, it is 0.001 s; and for regime (c), where multi-furcation and coalescence of the droplet occurs, it is 0.0005 s. Multiple splitting is a topic covered in this paper that can be applied to upcoming microfluidic platform-based devices.     

SMoS: a database of structural motifs of protein superfamilies

The Structural Motifs of Superfamilies (SMoS) database providesinformation about the structural motifs of aligned protein domainsuperfamilies. Such motifs among structurally aligned multiplemembers of protein superfamilies are recognized by the conservationof amino acid preference and solvent inaccessibility and areexamined for the conservation of other features like secondarystructural content, hydrogen bonding, non-polar interactionand residue packing. These motifs, along with their sequenceand spatial orientation, represent the conserved core structureof each superfamily and also provide the minimal requirementof sequence and structural information to retain each superfamilyfold. Received April 25, 2003; revised September 9, 2003; accepted September 24, 2003.     

Water-soluble polymeric chemosensor for detection of Cu2+ ions with high selectivity and sensitivity

Development of water-soluble chemosensors that are selective and sensitive to Cu²⁺ ions is of tremendous importance owing to their potential applications in biological systems. In the present work, we report the synthesis of a new water-soluble polymer containing pendant rhodamine units that are capable of highly selective and sensitive detection of Cu²⁺ ions in aqueous medium. Poly(2-pyrrolidinemethyl acrylate) was prepared using RAFT polymerization technique. The pyrrolidine nitrogen group in the polymer was subjected to Aza-Michael type addition with ethyl acrylate that was followed by covalent linking of rhodamine units to the polymer. This polymer was completely water-soluble and found to be capable of sensing Cu²⁺ ions in aqueous medium. Cu²⁺-induced opening of the spirolactam ring of the rhodamine units resulted in rapid and easily noticeable colour change, thus enabling a highly selective detection of Cu²⁺ in μmol range. The ability of these polymeric systems to detect Cu²⁺ ions in complete aqueous media has more importance than use of organic solvents to solubilize the polymer as reported previously, and thus opened a new window for application of these systems in the detection of copper ions in biological systems.     

Wear assessment of Cr2O3-/TiAlN-coated DAC-10 tool steel against steel and Al2O3 counterbodies

TiAlN film was deposited on Cr₂O₃-coated plasma-nitrided DAC-10 tool steel to obtained multilayer Cr₂O₃/TiAlN coating layer using cathodic arc deposition technique. The structural make-up of the coating was characterized using Atomic Force Microscopy (AFM) and X-ray diffraction methods, and the mechanical properties were evaluated using nanoindentation and nanoscratch test. The structural phases of the coating indicated the presence of crystalline CrO structure and cubic TiAlN phases. The coating showcased improved hardness (38 GPa), elastic modulus (387 GPa), and adhesion along with appreciable H/E (0.09) and H³/E² (0.366 GPa) attributes. Further, friction-induced wear behavior of the coating was investigated against steel and Al₂O₃ counterbodies under dry sliding conditions. The wear behavior of the coating was greatly influenced by its hardness and deformation properties and frictional behavior of the counterbodies. More spikes and fluctuation were observed in the frictional curve against Al₂O₃ counterbody attributed to the emanation of TiO₂, Cr₂O₃, and Al₂O₃ compounds due to dry sliding leading to the formation of flakes and delamination induced debris. Against the steel counterbody, the coating mainly formed a typical smooth glossy surface ascribed to the formation of Fe₂O₃ compound on the worn surface.     

Investigation of droplet coalescence propelled by dielectrophoresis

We propose dielectrophoretic force driven coalescence of droplets having equal or nonequal sizes with an electrode base actuation system over a solid surface. Coupled electrohydrodynamic conservation equations are solved to simulate the phenomenon based on finite volume scheme. Volume of fluid technique is used to capture the interface. Electric potential and dissimilarity index are varied to comprehend the coalescence dynamics. The interplay between the capillary and electrostatic influences during the coalescence is analyzed by tracking the dimension of the liquid connection formed at the onset of fusion. Efforts have been made to characterize the liquid bridge formation as a function of inertia normalized time scale. The capillary force showed higher dominance in the initial period of agglomeration. The electrostatic influence can be perceived at the latter stages of the growth of liquid connection. Directional predilection in the flow field is observed during the coalescence of dissimilar droplets. © 2018 American Institute of Chemical Engineers AIChE J, 65: 829–839, 2019     

Quinoline–Glycomimetic Conjugates Reducing Lipogenesis and Lipid Accumulation in Hepatocytes

Nonalcoholic fatty liver disease (NAFLD), which is characterized by excess accumulation of triglyceride in hepatocytes, is the major cause of chronic liver disease worldwide and no approved drug is available. The mechanistic target of rapamycin (mTOR) complexes has been implicated in promoting lipogenesis and fat accumulation in the liver, and thus, serve as attractive drug targets. The generation of non‐ or low cytotoxic mTOR inhibitors is required because existing cytotoxic mTOR inhibitors are not useful for NAFLD therapy. New compounds based on the privileged adenosine triphosphate (ATP) site binder quinoline scaffold conjugated to glucose and galactosamine derivatives, which have significantly low cytotoxicity, but strong mTORC1 inhibitory activity at low micromolar concentrations, have been synthesized. These compounds also effectively inhibit the rate of lipogenesis and lipid accumulation in cultured hepatocytes. This is the first report of glycomimetic–quinoline derivatives that reduce lipid load in hepatocytes.