Regularized nonnegative shared subspace learning

Joint modeling of related data sources has the potential to improve various data mining tasks such as transfer learning, multitask clustering, information retrieval etc. However, diversity among various data sources might outweigh the advantages of the joint modeling, and thus may result in performance degradations. To this end, we propose a regularized shared subspace learning framework, which can exploit the mutual strengths of related data sources while being immune to the effects of the variabilities of each source. This is achieved by further imposing a mutual orthogonality constraint on the constituent subspaces which segregates the common patterns from the source specific patterns, and thus, avoids performance degradations. Our approach is rooted in nonnegative matrix factorization and extends it further to enable joint analysis of related data sources. Experiments performed using three real world data sets for both retrieval and clustering applications demonstrate the benefits of regularization and validate the effectiveness of the model. Our proposed solution provides a formal framework appropriate for jointly analyzing related data sources and therefore, it is applicable to a wider context in data mining.     

Metallurgical Studies of Austenitic Stainless Steel 304 under Warm Deep Drawing

Austenitic stainless steel 304 was deep drawn with different blank diameters under warm conditions using 20 t hydraulic press. A number of deep drawing experiments both at room temperature and at 150 ℃ were conducted to study the metallography. Also, tensile test experiments were conducted on a universal testing machine up to 700 ℃ and the broken specimens were used to study the fractography of the material using scanning electron microscopy in various regions. The microstructure changes were observed at limiting draw ratio （LDR） when the cup is drawn at different temperatures. In austenitic stainless steel, martensite formation takes place that is not only affected by temperature, hut also influenced by the rate at which the material is deformed. In austenitic stainless steel 304, dynamic strain regime appears above 300 ℃ and it decreases the formability of material due to brittle fracture as studied in its fractography. From the metallographic studies, the maximum LDR of the material is observed at 150 ℃ before dynamic strain regime. It is also observed that at 150 ℃, grains are coarse in the drawn cups at LDR.     

Ultrathin PFPE Film Systems Fabricated by Covalent Assembly: An Application to Tribology

In this study, we have employed covalent molecular assembly to fabricate robust thin film structures comprising molecular layers and have demonstrated its application in tribology. An anhydride-functionalized polymer (gantrez) was deposited over an amine-functionalized silicon surface through covalent binding and employed as an intermediate layer between derivatized silicon and perfluoropolyether (PFPE). X-ray photoelectron spectroscopy, atomic force microscopy, and ellipsometry were employed to study the interfacial chemistry, morphology, and thickness of the assembled films. The films show excellent stability and strength against sonication, which can be attributed to the covalent interlayer linkage. Such films showed wear life of >100,000 cycles in ball-on-disk sliding tests at a normal load of 0.5 N and a sliding rotation of 200 rpm at a track radius of 3.2 mm. The performance was superior compared to that of PFPE-coated self assembled monolayers used as the lubricating layer. The film systems and assembly technique can be employed as nano-lubrication in several technological applications, such as information storage devices and micro-electro-mechanical systems.     

Ion-Exchange Behavior of New and Novel Zirconium(IV)-Based Composite Cation-Exchangers

The synthesized polyaniline-Zr(IV) selenoiodate and polyaniline-Zr(IV) selenomolybdate composite ion exchangers were characterized by Fourier transform infrared spectroscopy, UV spectra, X-ray diffraction, scanning electron microscope, thermogravimetric analysis, and conductivity studies. The ion-exchange capacities, effect of eluent concentration, elution time, elution behavior, and pH on ion-exchange capacity were also studied to exploit the ion-exchange capability of the composites. The study revealed that polyaniline-Zr(IV) selenoiodate and polyaniline-Zr(IV) selenomolybdate ion exchangers are having excellent ion-exchange capacity values for K⁺ ion 1.36 and 1.44?meq?g^?1, respectively. The organic polymeric part of the composites provides mechanical and chemical stability, whereas the inorganic part supports the ion-exchange behavior and thermal stability. The increase in electrical conductivity is due to the inorganic and organic parts. A mechanism for the formation of the polyaniline-Zr(IV) selenoiodate and polyaniline-Zr(IV) selenomolybdate composite ion exchangers is discussed, which may also be applied for the preparation of other composite ion exchangers. Sorption behavior of metal ions on the composites was studied in different solvent systems. On the basis of distribution coefficient values (K_d), it has been found that the cation-exchange materials are highly selective for Pb(II)-ions. Such modified composite materials can be applied as an electrochemically switchable ion exchanger for water treatment, especially water softening.     

Periodic nano/micro-hole array silicon solar cell

In this study, we applied a metal catalyst etching method to fabricate a nano/microhole array on a Si substrate for application in solar cells. In addition, the surface of an undesigned area was etched because of the attachment of metal nanoparticles that is dissociated in a solution. The nano/microhole array exhibited low specular reflectance (<1%) without antireflection coating because of its rough surface. The solar spectrum related total reflection was approximately 9%. A fabricated solar cell with a 40-μm hole spacing exhibited an efficiency of 9.02%. Comparing to the solar cell made by polished Si, the external quantum efficiency for solar cell with 30 s etching time was increased by 16.7%.     

Performance and emission characteristics of diesel engine operated on plastic pyrolysis oil with exhaust gas recirculation

The objective of this research was to study the performance and emission characteristics of using waste plastic pyrolysis oil in diesel engine without any engine modification. The engine used in this study is a four-stroke single-cylinder naturally aspirated diesel engine (compression ignition). In the present work, the engine fuelled with blends of diesel fuel (DF) with plastic oil in the ratio of 90:10 (blend10%), 80:20 (blend20%), 70:30 (blend30%), and 50:50 (blend50%) are experimentally measured the efficiencies and emissions, analysed the performance, and compared results with that of DF.     

Ultra-light-weight composites from bamboo strips and polypropylene web with exceptional flexural properties

Fine bamboo strips (BSs) have been laid on polypropylene (PP) web, stacked, and compression molded to prepare unconsolidated light-weight (0.312 g/cm³) composites. Composite properties are superior compared with jute-based composites and bamboo strips show potential to replace fiberglass or polyurethane in composites. Flexural strength, modulus, offset yield load, and Noise Reduction Coefficient (NR) of the BS–PP composites are 5.8×, 2.9×, 6.5×, and 1.4× higher, respectively, compared to jute–PP composites. Bamboo-based non-consolidated composites with excellent mechanical and sound absorption properties utilizing the methods described in this research provide an opportunity to manufacture functional composites with bio-based materials leading to reduction of environmental pollution and sustainable manufacturing.