Entrainment by axisymmetric jets impinging on a flat plate

An experimental technique is described for the determination of the entrainment in an axisymmetric gaseous jet impinging normally on a flat plate situated below the nozzle. Typical results are given of experimental work carried out using this technique for an Rix jet flowing into a like atmosphere of similar density. These results suggest that the relationships describing the entrainment are: (a) m/mo = 0.3 hid for the axial jet, and (b) mimo = 0.6 Rid for the wall jet. It is also deduced that the growth of the *wall jet is described by the equation: 5 w r approximately. Some experimental results are given for a jet at a higher temperature than the surrounding atmosphere

PSC implementation and integration

Hardware and software design of the performance seeking control (PSC) for the NASA F-15 research aircraft are described. The hardware architecture, vehicle management system computer (VMSC), pilot interface, and PSC mode selection are discussed. The PSC software is distributed among the VMSC, central computer, digital electronic engine controls (DEEC's), and electronic air inlet controllers (EAIC's). The major PSC modules, VMSC logic, VMSC channel C memory requirements, VMSC channel C timing, and navigation control indicator (NCI) variables and where they are located are presented

An exploratory study of fashion social customer service

La tecnología digital ha cambiado la forma de las marcas de moda se comunican con los consumidores y del mercado de sus productos. Por otra parte, el auge de las plataformas de medios sociales en los últimos años ha ayudado a hacer este diálogo más atractivo, convocando a millones de nuevos consumidores a  comprometerse con las marcas a nivel personal (PEW, 2013). Un reciente informe de Drapers (2013) sobre la innovación en el mercado del retail en moda, sugiere que el 52 % de las empresas de la moda están utilizando los medios sociales para la interacción con el cliente y la gestión de las relaciones. El objetivo de esta investigación es explorar el uso de los medios de comunicación social para el servicio al cliente. En primer lugar el estudio identificará las razones por las cuales las marcas de moda están utilizando esta plataforma y en segundo lugar, se examinará cómo las marcas las están utilizando. Las empresas que son líderes en este espacio son en su mayor parte empresas de dedicación exclusiva estadounidenses. Como ejemplo, Warby Parker la innovadora marca de anteojos ha estado respondiendo a los problemas de servicio al cliente a través de You Tube clips que actualmente reciben más de 100 visitas (Mashable, 2013). Uno de los grandes retos, y una oportunidad al mismo tiempo, es que los consumidores utilizan las redes sociales para quejarse de los problemas de servicio al cliente (Brandwatch, 2013). ASOS abrió las cuentas de Facebook y Twitter “Estamos aquí para ayudar” para permitir que sus otros canales sociales sean utilizados con fines de relaciones públicas y comunicación minimizando así el contenido negativo en ellos (Bauer, 2013).  Conversocial (2013) es un proveedor de atención al cliente especialista en medios sociales, que ha medido que el monitoreo y la respuesta efectiva en el servicio al cliente en redes sociales pueden tener un retorno directo sobre la inversión. Debido a la ausencia de marcos teóricos asociados, el presente estudio adopta un enfoque cualitativo, utilizando fuentes secundarias, el análisis de contenido de las plataformas de medios sociales y entrevistas en profundidad con representantes de marcas de moda con el fin de cumplir el  objetivo de la investigación.Digital technology has changed the way fashion brands communicate with consumers and market their products. Moreover, the rise of social media platforms in recent years has helped to make this dialogue more appealing, inviting millions of new consumers to engage with brands on a personal level (PEW, 2013). A recent Drapers (2013) report on innovation in fashion retail suggests that 52% of fashion businesses are using social media for customer interaction and relationship management. The aim of this research is to explore the use of social media for customer service. Firstly the study will identifythe reasons why fashion brands are using this platform and secondly it will examine how brands are using it. Companies who are leading in this space are predominately American or Pure Play. To illustrate Warby Parker the innovative eyewear brand has been responding to customer service issues via You Tube clips which are now getting over 100 views (Mashable, 2013). One of the major challenges but also opportunities is that consumers use social media to complain about customer service issues (Brandwatch, 2013). ASOS has dedicated Facebook and Twitter ‘Here to Help’ accounts which allow their other socialchannels to be used for PR and communication purposes thereby minimizing negative content on them (Bauer, 2013). Conversocial (2013) is a specialist social media customer service provider which has calculated that effective monitoring and reaction to social customer service can have a direct return on investment. Due to an absence of accepted theoretical frameworks this study adopts a qualitative approach, using secondary research, content analysis of social media platforms and in-depth interviews with fashion brand representatives in order to meet the research aim

Failoure On All Fronts: The United States Army in the First Year of the War of 1812

The United States declared war on the United Kingdom in the hopes of defending the nation\u27s national honor. However, the United States Army was unprepared to go wage war. The army\u27s supply system, militia system, and field commanders failed and led to a disastrous first year of conflict

PSC algorithm description

An overview of the performance seeking control (PSC) algorithm and details of the important components of the algorithm are given. The onboard propulsion system models, the linear programming optimization, and engine control interface are described. The PSC algorithm receives input from various computers on the aircraft including the digital flight computer, digital engine control, and electronic inlet control. The PSC algorithm contains compact models of the propulsion system including the inlet, engine, and nozzle. The models compute propulsion system parameters, such as inlet drag and fan stall margin, which are not directly measurable in flight. The compact models also compute sensitivities of the propulsion system parameters to change in control variables. The engine model consists of a linear steady state variable model (SSVM) and a nonlinear model. The SSVM is updated with efficiency factors calculated in the engine model update logic, or Kalman filter. The efficiency factors are used to adjust the SSVM to match the actual engine. The propulsion system models are mathematically integrated to form an overall propulsion system model. The propulsion system model is then optimized using a linear programming optimization scheme. The goal of the optimization is determined from the selected PSC mode of operation. The resulting trims are used to compute a new operating point about which the optimization process is repeated. This process is continued until an overall (global) optimum is reached before applying the trims to the controllers