This paper reports the thermal performance of a new cylindrical solar collector based on an experimental investigation with this difference that instead of the collector tube with absorbent coating, coil into a spiral copper tube is placed in the center of the collector. The spiral shape of the tube, heat transfer without disruption or increase the heat transfer area, is increasing. In this cas...

This paper demonstrates the advantages of extending the scope of prototyping to the requirements capture phase of a project. Prototyping has long been used to elicit users’ responses to ready-formed designs (Boehm, 1988), but only recently has the use of concept demonstrators (Sanderson, 1997) and early throw-away prototypes (Smith et al., 1990) been suggested as a means to capture response to ...

The improvement in reverse recovery of power NPN bipolar transistor (BJT) through incorporation of ‘‘universal contact’’ in the base is studied in detail. It is shown that use of universal contact allows redistribution of base current in saturation from collector region where recombination lifetime is high to extrinsic base region where effective recombination lifetime is low. The reverse recov...

A solar absorption icemaker was designed. It is an intermittent system and uses Calcium Chloride and Ammonia as absorbent and refrigerant respectively. The single glazed collector/absorber/generator unit uses a plane glass sheet as the outer cover. Overall collector plate exposed area is 1.0m. A thermodynamic simulation of the icemaker has been performed in order to investigate the effect that ...

A system is being tested for recovery of rf power by conversion to DC pulsed power. The system consists of a cyclotron autoresonance accelerator (CARA) [1,2], and a single stage depressed collector (Fig. 1). A 50 kV, 5 A electron beam is injected into CARA, and up to 1 MW of S-band rf power is absorbed by the beam with efficiency exceeding 95%. The beam then passes to a single stage depressed c...

Traditionally, implementations for functional logic languages (FLP) have used depth-first search to implement narrowing, a well-known search strategy. While this approach yields good performance, it is unnecessarily restrictive in the sense that some programs lead to non-termination (the search computes forever in one part of the search space, failing to consider the rest) when clearly they sho...

BACKGROUND In low and middle income countries (LMICs), and other areas with low resources and unreliable access to the Internet, understanding the emerging best practices for the implementation of new mobile health (mHealth) technologies is needed for efficient and secure data management and for informing public health researchers. Innovations in mHealth technology can improve on previous metho...

in this study, the possibility of producing coal with less than 11% ash from tailings of flotation process was investigated. the effect of six flotation parameters: collector type, collector consumption, frother type, frother consumption, pulp density and mixing rate were studied on a sample from a tailing dam. a software based experimental design approach (dx7) was applied to determine and mod...

The possibility of using flat plate collector in northern parts of Iran specially city of Rasht has been investigated in this paper. According to the high humidity in the northern parts of this country, diffuse radiation plays a more important role than direct radiation. This fact can change the results of delivered solar energy and the best tilt angle of the collector compared to the sunny cen...