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Tempe, AZ, United States

Hashmi U.S.,Bahria University | Anjum N.,Aerospace | Israr A.,Bahria University
Proceedings of International Conference on Computational Intelligence, Modelling and Simulation | Year: 2013

The Global software industry worth about $293 billion in 2011 is plagued by an ironic fact that a huge proportion of the software projects are below their schedules or are not completed due to bad planning, poor specification of software product specifications and technical inadequacies. The concept of software quality management is gaining increasingly more and more popularity as software firms now prefer the use of quality assurance practices to provide software products that are more reliable and efficient. This paper aims to augment earlier research conducted relating to software quality assurance practices and identifies any link between customer satisfaction and optimization of costs associated with the development and maintenance of software products. The gathered data from Clients and development teams is analyzed in SPSS tool to measures the impact of implementing Software Quality Standards on Customer Satisfaction through variations in Product Development Time and Product Safety. © 2013 IEEE. Source

Staresinic M.,University of Ljubljana | Sumiga B.,Aerospace | Sumiga B.,University of Ljubljana | Boh B.,University of Ljubljana
Tekstilec | Year: 2011

The article presents the possibilities of using scanning electron microscopy (SEM) for the microencapsulation research purpose and for the visualisation of microcapsule applications on textiles. The laboratory and industrial scale synthesis of aminoplast microcapsules with in situ polymerisation of melamine-formaldehyde prepolymers, containing fragrances, essential oils and phase change materials (PCM) as core materials, is presented. The following properties of microcapsules were studied with the use of SEM in combination and in comparison with classical methods of microcapsule properties evaluation: (a) appearance, size and morphology of microcapsules, including the determination of wall thickness, (b) visualisation of fragrance and/or essential oils containing aminoplast microcapsules on non-woven and woven textile carriers, (c) evaluation of mechanical resistance of PCM microcapsule walls under pressure at an elevated temperature, and (d) detection of morphological changes of PCM microcapsules caused by ammonia scavenger. For graphical analyses, the processing of SEM images was performed with ImageJ software. Source

Babu S.S.,Aerospace | Babu S.S.,Oak Ridge National Laboratory
PTM 2015 - Proceedings of the International Conference on Solid-Solid Phase Transformations in Inorganic Materials 2015 | Year: 2015

This paper pertains to non-equilibrium solid-solid phase transformation during dynamic thermal conditions typical to that of welding and additive manufacturing processes. Need for measurement of these phenomena using in-situ and ex-situ characterization tools, as well as, prediction using computational modeling is highlighted with two examples. In the first example, kinetics of dissolution and growth of M23C6 during normalizing, welding and post-weld heat treatment in Cr-Mo steels is discussed. In the second example, growth and dissolution of γ' and γ" within g phase in an Inconel 718 alloy during laser additive manufacturing will be discussed. Source

Sumiga B.,University of Ljubljana | Knez E.,Aerospace | Vrtacnik M.,University of Ljubljana | Savec V.F.,University of Ljubljana | And 2 more authors.
Acta Chimica Slovenica | Year: 2011

Paraffinic phase change materials (PCM) were microencapsulated by in situ polymerization of melamineformaldehyde prepolymers. Partly methylated trimethylolmelamine was used as an aminoaldehyde prepolymer for the microcapsule wall, a styrene-maleic acid anhydride copolymer as an emulsifier and modifying agent, and ammonia as a scavenger for reducing residual formaldehyde. For the determination of residual formaldehyde in a ppm concentration range, EDANA and malachite green analytical methods were studied, and the EDANA 210.1-99 was applied for the determination of residual formaldehyde in 25 samples of microcapsules, produced in a 200-L reactor. A linear correlation was observed between the added ammonia scavenger concentration and the reduction of residual formaldehyde concentration. Compared with 0.45% (4500 ppm) formaldehyde in a non-treated microcapsule suspension, with ammonia scavenger concentrations 0.80, 0.90 and 1.35%, the concentration of residual formaldehyde dropped to 0.27, 0.20 and 0.09% (i.e. 2700, 2000 and 900 ppm), respectively. Morphological characterisation of microcapsules by SEM and microcapsule wall permeability measurements by gravimetry / mass loss at an elevated temperature (135 °C) suggested that ammonia positively contributed to the wall elasticity / durability, while microcapsules with no ammonia scavenger added tended to have more brittle walls, and were more prone to cracking. Source

Walter Engines A.S, Walter A.S. and Aerospace | Date: 1992-05-19

engines for aircraft and watercraft. medical devices; namely, artificial limbs and joints, and dental prostheses and implants. engines for land vehicles.

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