Fill and vent quick disconnect

Hydraulic disconnect coupling on ground serving half of spacecraft refrigeration cooling system employs movable center stem for venting and closing nipple poppet. Self sealing poppet quickly connects cooling system to spacecraft without manual work. Recessed sealing surface insures open poppet when stem retracts

Ecotourism sustainability

Ecotourism is defined by the Ecotourism Society as “responsible travel to natural areas which conserves the environment and improves the welfare of the local people”. The effect of this type of tourism poses both negative and positive impacts on the tourist and society. The importance of true ecotourism is to conserve and improve the environment, but the sustainability of this type of tourism can face ecological and economic challenges

Will the Dollar Be Dethroned as the Main Reserve Currency?

The U.S. dollar was in the line of fire as leaders from the largest developed and developing countries participated in the G8 meeting on July, 2009. China and other emerging market heavy-weights such as Russia and Brazil are pushing for debate on an eventual shift away from the dollar to a new global reserve currency. These countries are particularly concerned about the heavy debt burden of the United States and fear inflation will further debase the dollar which has lost 33 percent in value against other major currencies since 2002. Will the dollar continue as the main reserve currency of the world? What are the other currencies to watch as challengers to the throne? This paper address these questions

Diacetyl and Acetylmethylcarbinol production in the manufacture of unsalted butter

During the ripening of sweet or neutralized sour cream in laboratory and semi-commercial trials there were some irregularities in the effects of various factors on the diacetyl and acetylmethylcarbinol contents of the cream, but generally the contents were increased by an increase in the acidity to which the cream was ripened, by addition of small ·amounts of citric acid to the cream and by agitation (shaking in the laboratory trials and revolving the coils in the semi-commercial trials) during the ripening. In some trials the contents were greatly influenced by the use of certain butter cultures, while in other trials they were not. In general, as the diacetyl contents increased in the ripening cream the acetylmethylcarbinol contents. also increased, but there were variations from this relationship. The occasional decreases in diacetyl contents often were accompanied by increases in acetylmethylcarbinol contents. Some of the ripening procedures used with the cream were beneficial from the standpoint of score of the butter under certain holding conditions. These procedures included development of higher acidities in the cream, addition of citric acid to the cream and agitation of the cream during ripening

History and Silence. Purge and the Rehabilitation of Memory in Late Antiquity.

In AD 431 a statue of the senator Virius Nicomachus Flavianus was erected in Trajanâs Forum at Rome. On its base was inscribed an imperial letter that rehabilitated Flavianusâ reputation (CIL 6. 1783). Flavianus had committed suicide after the usurper Eugenius, whose revolt he had supported, was defeated in 394. In the aftermath, Flavianus was subject to damnatio memoriae for his part in the rebellion. This disgrace and subsequent rehabilitation form the theme of H.âs study, which has at its heart a study of the inscription on the statue base

History and Silence. Purge and the Rehabilitation of Memory in Late Antiquity.

In AD 431 a statue of the senator Virius Nicomachus Flavianus was erected in Trajanâs Forum at Rome. On its base was inscribed an imperial letter that rehabilitated Flavianusâ reputation (CIL 6. 1783). Flavianus had committed suicide after the usurper Eugenius, whose revolt he had supported, was defeated in 394. In the aftermath, Flavianus was subject to damnatio memoriae for his part in the rebellion. This disgrace and subsequent rehabilitation form the theme of H.âs study, which has at its heart a study of the inscription on the statue base

Flight Mechanics and Control of Escape Manoeuvres in Hummingbirds. I. Flight Kinematics

Hummingbirds are nature’s masters of aerobatic manoeuvres. Previous research shows that hummingbirds and insects converged evolutionarily upon similar aerodynamic mechanisms and kinematics in hovering. Herein, we use three-dimensional kinematic data to begin to test for similar convergence of kinematics used for escape flight and to explore the effects of body size upon manoeuvring. We studied four hummingbird species in North America including two large species (magnificent hummingbird, Eugenes fulgens, 7.8 g, and blue-throated hummingbird, Lampornis clemenciae, 8.0 g) and two smaller species (broad-billed hummingbird, Cynanthus latirostris, 3.4 g, and black-chinned hummingbirds Archilochus alexandri, 3.1 g). Starting from a steady hover, hummingbirds consistently manoeuvred away from perceived threats using a drastic escape response that featured body pitch and roll rotations coupled with a large linear acceleration. Hummingbirds changed their flapping frequency and wing trajectory in all three degrees of freedom on a stroke-by-stroke basis, likely causing rapid and significant alteration of the magnitude and direction of aerodynamic forces. Thus it appears that the flight control of hummingbirds does not obey the ‘helicopter model’ that is valid for similar escape manoeuvres in fruit flies. Except for broad-billed hummingbirds, the hummingbirds had faster reaction times than those reported for visual feedback control in insects. The two larger hummingbird species performed pitch rotations and global-yaw turns with considerably larger magnitude than the smaller species, but roll rates and cumulative roll angles were similar among the four species

Flight Mechanics and Control of Escape Manoeuvres in Hummingbirds. II. Aerodynamic Force Production, Flight Control and Performance Limitations

The superior manoeuvrability of hummingbirds emerges from complex interactions of specialized neural and physiological processes with the unique flight dynamics of flapping wings. Escape manoeuvring is an ecologically relevant, natural behaviour of hummingbirds, from which we can gain understanding into the functional limits of vertebrate locomotor capacity. Here, we extend our kinematic analysis of escape manoeuvres from a companion paper to assess two potential limiting factors of the manoeuvring performance of hummingbirds: (1) muscle mechanical power output and (2) delays in the neural sensing and control system. We focused on the magnificent hummingbird (Eugenes fulgens, 7.8 g) and the black-chinned hummingbird (Archilochus alexandri, 3.1 g), which represent large and small species, respectively. We first estimated the aerodynamic forces, moments and the mechanical power of escape manoeuvres using measured wing kinematics. Comparing active-manoeuvring and passive-damping aerodynamic moments, we found that pitch dynamics were lightly damped and dominated by the effect of inertia, while roll dynamics were highly damped. To achieve observed closed-loop performance, pitch manoeuvres required faster sensorimotor transduction, as hummingbirds can only tolerate half the delay allowed in roll manoeuvres. Accordingly, our results suggested that pitch control may require a more sophisticated control strategy, such as those based on prediction. For the magnificent hummingbird, we estimated that escape manoeuvres required muscle mass-specific power 4.5 times that during hovering. Therefore, in addition to the limitation imposed by sensorimotor delays, muscle power could also limit the performance of escape manoeuvres