The Effect of Slider Geometry on the Performance of a Powder Lubricated Bearing

The experimental investigation was carried out for dry contact tribosystems to elucidate the ascertained, yet uncharacterized, relationship between the coefficient of friction, η and apparent contact geometry in sliders. This paper presents the results of various experimentally evaluated slider pad width to length ratios, B/L (L is signified with direction of motion), while maintaining the unit loading constant. The empirical data is intended to provide guidance in design and in theoretical prediction of optimum bearing geometry for solid/powder lubricated systems.

In this experiment, a liquid lubricant, two different dry powders (MoS₂ and TiO₂), and four test specimens with B/L ratios ranging from 0.5 to 2.0 were used. An alternative experimental method has been used to simulate wear debris in the dry contact tribosystems, vis-à-vis dry powders, which were introduced into the interface gap to address the affinity of the wear process. Slider pads' performance characteristics as a function of the applied load (ranging from 34.5 to 345 kPa) and surface speed (0.004 to 4.5 m/sec) were determined at ambient condition. Experimental evidence shows that in the pre-hydrodynamic regime (low speed) the friction coefficient, η, decreases as B/L ratio increased from 0.5 to 1.5. Beyond a B/L ratio of 1.5, η increased with increasing B/L ratios. Optimum B/L ratio of 1 (based on measured minimum η) was identified for operation in the hydrodynamic regime. Overall reduction in η as a function of load was observed which is independent of B/L ratio and lubricant type. Also presented are the velocity effects on slider frictional performance.     

Genetically engineered brain drug delivery vectors: cloning, expression and in vivo application of an anti-transferrin receptor single chain antibodystreptavidin fusion gene and protein

A single chain Fv antibody–streptavidin fusion proteinwas expressed and purified from bacterial inclusion bodies followingcloning of the genes encoding the variable region of the heavychain and light chain of the murine OX26 monoclonal antibodyto the rat transferrin receptor. The latter undergoes receptormediated transcytosis through the brain capillary endothelialwall in vivo, which makes up the blood–brain barrier (BBB);therefore, the OX26 monoclonal antibody and its single chainFv analog may act as brain drug delivery vectors in vivo. Attachmentof biotinylated drugs to the antibody vector is facilitatedby production of the streptavidin fusion protein. The bi-functionalityof the OX26 single chain Fv antibody–streptavidin fusionprotein was retained, as the product both bound biotin and therat transferrin receptor in vitro and in vivo, based on pharmacokineticand brain uptake analyses in anesthetized rats. The attachmentof biotin–polyethyleneglycol–fluorescein to theOX26 single chain Fv antibody–streptavidin fusion proteinresulted in illumination of isolated rat brain capillaries inconfocal fluorescent microscopy. In conclusion, these studiesdemonstrate that genetically engineered single chain Fv antibody–streptavidinfusion proteins may be used for non-invasive neurotherapeuticdelivery to the brain using endogenous BBB transport systemssuch as the transferrin receptor.     

De Novo Missense Mutations in TNNC1 and TNNI3 Causing Severe Infantile Cardiomyopathy Affect Myofilament Structure and Function and Are Modulated by Troponin Targeting Agents

Rare pediatric non-compaction and restrictive cardiomyopathy are usually associated with a rapid and severe disease progression. While the non-compaction phenotype is characterized by structural defects and is correlated with systolic dysfunction, the restrictive phenotype exhibits diastolic dysfunction. The molecular mechanisms are poorly understood. Target genes encode among others, the cardiac troponin subunits forming the main regulatory protein complex of the thin filament for muscle contraction. Here, we compare the molecular effects of two infantile de novo point mutations in TNNC1 (p.cTnC-G34S) and TNNI3 (p.cTnI-D127Y) leading to severe non-compaction and restrictive phenotypes, respectively. We used skinned cardiomyocytes, skinned fibers, and reconstituted thin filaments to measure the impact of the mutations on contractile function. We investigated the interaction of these troponin variants with actin and their inter-subunit interactions, as well as the structural integrity of reconstituted thin filaments. Both mutations exhibited similar functional and structural impairments, though the patients developed different phenotypes. Furthermore, the protein quality control system was affected, as shown for TnC-G34S using patient’s myocardial tissue samples. The two troponin targeting agents levosimendan and green tea extract (-)-epigallocatechin-3-gallate (EGCg) stabilized the structural integrity of reconstituted thin filaments and ameliorated contractile function in vitro in some, but not all, aspects to a similar degree for both mutations.     

Task conflict and team creativity: A question of how much and when.

Bridging the task conflict, team creativity, and project team development literatures, we present a contingency model in which the relationship between task conflict and team creativity depends on the level of conflict and when it occurs in the life cycle of a project team. In a study of 71 information technology project teams in the greater China region, we found that task conflict had a curvilinear effect on team creativity, such that creativity was highest at moderate levels of task conflict. Additionally, we found this relationship to be moderated by team phase, such that the curvilinear effect was strongest at an early phase. In contrast, at later phases of the team life cycle, task conflict was found to be unrelated to team creativity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Integrating Java and CORBA: a programmer's perspective

The introduction of Java's proprietary remote method invocation (RMI) with version 1.1 of the Java Development Kit simplified the challenging task of developing distributed object-based systems. RMI provides convenient integration with Java; however, it lacks interoperability with other languages. The Object Management Group's Common Object Request Broker Architecture (CORBA), on the other hand, is a platform- and language-neutral specification for developing distributed object systems. CORBA provides services not covered by RMI, such as managing transactional safety and persistency. We use a small chat room application to describe how a programmer can combine Java RMI's ease of use with CORBA's language neutrality. We start with an implementation based on a set of distributed objects using RMI. We then adapt the example to CORBA or, more specifically, the RMI-over-IIOP (Internet inter-ORB protocol) specification developed by Sun and IBM     

Etching Effect on CMP of Different GaN Layers

Chemical mechanical polishing (CMP) was used to etch various GaN materials, such as GaN layers on sapphire and silicon carbide substrates grown by metal-organic chemical vapor deposition and thick GaN layers grown by physical vapor transport. It was found that CMP could reveal the dislocations in GaN surfaces due to a selective etching component. After the optimization of CMP condition, the surface finish improved and the subsurface damage was almost completely removed, demonstrated by atomic force microsco...     

Spray-Assisted Polyelectrolyte Multilayer Buildup: from Step-by-Step to Single-Step Polyelectrolyte Film Constructions

The alternate deposition of polyanions and polycations on a solid substrate leads to the formation of nanometer to micrometer films called Polyelectrolyte Multilayers. This step-by-step construction of organic films constitutes a method of choice to functionalize surfaces with applications ranging from optical to bioactive coatings. The method was originally developed by dipping the substrate in the different polyelectrolyte solutions. Recent advances show that spraying the polyelectrolyte solutions onto the substrate represents an appealing alternative to dipping because it is much faster and easier to adapt at an industrial level. Multilayer deposition by spraying is thus greatly gaining in interest. Here we review the current literature on this deposition method. After a brief history of polyelectrolyte multilayers to place the spraying method in its context, we review the fundamental issues that have been addresses so far. We then give an overview the different fields where the method has been applied.     

Report on the 7th International Conference on Autonomous Infrastructure,Management, and Security (AIMS 2013): Emerging Management Mechanisms for the Future Internet

This article contains the report on AIMS 2013, which was held on June 25–28, 2013 at the Universitat Politècnica de Catalunya (UPC), Spain and was driven by the theme “Emerging Management Mechanisms for the Future Internet”. It covers the three main parts that formed the event program: the keynote and technical sessions of the main track, the PhD workshop and the hands-on tutorials. Finally, the report highlights the evolutions that would shape the future version of AIMS.     

Mathematical Models of the Common-Source and Common-Gate Amplifiers Using a Metal-Ferroelectric-Semiconductor Field Effect Transistor

Mathematical models of the common-source and common-gate amplifiers using metal-ferroelectric-semiconductor field effect transistors (MFSFETs) are developed in this paper. The models are compared against data collected with MFSFETs of varying channel lengths and widths, and circuit parameters such as biasing conditions are varied as well. Considerations are made for the capacitance formed by the ferroelectric layer present between the gate and substrate of the transistors. Comparisons between the modeled and measured data are presented in depth.