SOLAR ARCHITECTURE

Abstract

The term “solar architecture”is a very dangerous one. As we were always told, there is architecture as to create shelter for people. We have architecture for big people, small people, white people, black people, any kind of colour of people, healthy people, disabled people. And you start thinking to yourself, making these classifications. Does that help? And you probably have architecture for all of them. So there is disabled architecture or black architecture, lbelieve we should say that there isn't. It is quite simple: there is good architecture and there is bad architecture. Good architecture has to take care of all these factors, of solar energy as well. Probably there is a problem that, particularly in the later years, architects have actually not done that. But if you study history you will come to the conclusion, that the solar “factor” has always influenced good architecture? The Jama Manta Observatory in Jaipur where the Shajahan created enormous buildings to actually follow the paths of the sun, you could say are the purest form of solar architecture, but first of it is beautiful architecture. The same is true for Saint Chapel, it is very good architecture, but it is solar architecture, because it wouldn't work without the     

The un-utilizability design method for collector-storage walls

The monthly-average auxiliary energy requirement of a building with a collector-storage (Trombe) wall is estimated using upper and lower theoretical limits to system performance. These two limits on the building auxiliary energy requirements result from considering the building and collector-storage wall to have either zero thermal capacity or infinite thermal capacity. With zero thermal capacity, all solar gain in excess of the load, on an instantaneous basis, is not useful and must be dumped. With infinite thermal capacity, the house is able to store any gain in excess of the instantaneous load and use it at some later time. Auxiliary energy use by real systems will fall between these two theoretical bounds. An empirical correlation is presented for the fraction of the load met by the collector-storage wall, F, for systems with finite capacity. The correlation is based on the solar radiation statistic, utilizability. The correlation is compared to yearly TRNSYS simulation results for a wide variety of system types. The root-mean-square difference between F found from the un-utilizability method and from TRNSYS simulations is less than 4 per cent. One advantage of this method over other simplified design methods is that this method covers a much larger range of design parameters.     

In-situ measurement of ethanol tolerance in an operating fuel cell

Ethanol is seen as an attractive option as a fuel for direct ethanol fuel cells and as a source for on-demand production of hydrogen in portable applications. While the effect of ethanol on in-situ electrode behavior has been studied previously, these efforts have mostly been limited to qualitative analysis. In alkaline fuel cells, several cathode catalysts, including Pt, Cu triazole, and Ag can be used. Here, we apply a methodology using a microfluidic fuel cell to analyze in-situ the performance of these cathodes as well as Pt anodes in the presence of ethanol and acetic acid, a common side product from ethanol oxidation. For a given concentration of ethanol (or acetic acid), the best cathode catalyst can be determined and the kinetic losses due to the presence of ethanol (or acetic acid) can be quantified. These experiments also yield information about power density losses from the presence of contaminants such as ethanol or acetic acid in an alkaline fuel cell. The methodology demonstrated in these experiments will enable in-situ screening of new cathodes with respect to contaminant tolerance and determining optimal operational conditions for alkaline ethanol fuel cells.     

Optimizing the overall configuration of a He-cooled W-alloy divertor for a power plant

A number of different He-cooled divertor configurations have been proposed for magnetic fusion energy (MFE) power plant application. They range in scale from a plate configuration with characteristic dimension of the order of 1 m, to the ARIES-CS T-tube configuration with characteristic dimension of the order of 10 cm, to the EU FZK finger concept with characteristic dimension of the order of 1.5 cm. All these designs utilize tungsten or tungsten alloy as structural material. This paper considers the characteristics of the different divertor configurations and proposes the possibility of optimizing the design by combining different configurations in an integrated design based on the anticipated divertor heat flux profile.     

Reactive ion etching of PECVD silicon nitride in SF6 plasma

The reactive ion etching of PECVD silicon nitride thin films has been investigated using SF₆ plasma. Effects of variations of process parameters such as pressure (50–350 mTorr), RF power (50–250 W), gas flow rate (3–130 sccm) and additions of O₂ and He (0–50%) in SF₆, on the PECVD silicon nitride etch rate and selectivity to the AZ 1350J photoresist were examined. An etch rate of 1 μm/min has been obtained under the condition of 150 mTorr, 100 W and 60 sccm. Experimental results also indicated a maximum etch rate at approximately 30% O₂ while addition of He showed only dilution effect. A nitride/photoresist selectivity ranging from 1 to 3:1 has been obtained.     

Evaluation of crack-Growth resistance curve for a particulate ceramic–Metal composite

A technique is described to evaluate the crack growth resistance behaviour in brittle ceramic-base materials. In this method, the crack increment measurements during the stable crack propagation process are not required. The crack growth resistance curves are studied for a particulate ceramic–metal composite in the system lanthanium chromite–chromium. Experiments were performed with standard fracture mechanics single-edge notched beam specimens in a temperature range from room temperature up to 1100°C. Effect of temperature on crack growth resistance behaviour is discussed.     

Development of rugged and crack-resistant structures in ceramics (review)

The paper considers methods for increasing crack resistance in ceramics, including microcracking in local stress areas, reorientation of crack movement, polymorphous martensite transition in partly stabilized zirconium dioxide, and bridging of cracks with a plastic phase or crystals with highly nonisometric shape (plates, needles, fibers) in the context of the irreversibility and nonequilibrium, producing self-organization, and a synergetic approach. The possibility of increasing crack resistance due to diffuse polymorphous transitions, twinning, and mechanochemical reactions is discussed.     

Design of polymeric dispersants for waterborne coatings

Block and random copolymers of ammonium methacrylate and dimeth-ylaminoethyl methacrylate have been synthesized and tested as dispersants of various organic and inorganic pigments in formulations for waterborne paints. Blockiness of the co-monomer distribution is a prerequisite for good color characteristics in the final paint. It is however noteworthy that a tapered diblock (one-step anionic synthesis), a diblock copolymer with a regular change in composition from one block to the other one, has an interfacial activity quite comparable to the parent “pure” diblock copolymer (two-step anionic synthesis). The most interesting observation is that the poly(dimethylaminoethyl methacrylate) anchoring block can impart stability to dispersions of pigments as different as iron oxide, a blue Cu-phthalocyanine pigment, and a red organic pigment based on pyrrole in representative aqueous paint formulations. This type of diblock copolymer is promising for the design of universal dispersants. Center for Education and Research on Macromolecules (CERM), Sart-Tilman, B6, 4000 Liège, Belgium. Rijksstraatweg 31, P.O.Box 3, 2170 BA Sassenheim, The Netherlands.     

Adsorption processes in the technology of polymer composite materials with magnetic properties

The selection of a model of an adsorption solution was substantiated. Satisfaction of the Larionov criterion [3] indicates that the selected parameters of the adsorption phase do not contradict the physical picture of adsorption. The basic thermodynamic characteristics of adsorption of phenol-formaldehyde oligomer on the solid surface of ferromagnetic disperse fillers were calculated. The correlation of the limiting adsorption value, adsorption layer thickness, and adhesive strength in polymeric magnetic materials was demonstrated. Translated from Khimicheskie Volokna, No. 3, pp. 50–52, May–June, 1998.     

Characteristics of phase transitions in poly[bis(trifluoroethoxy)phosphazene]

The data on phase transitions in bis(trifluoroethoxy)phosphazene were examined and generalized. Their nature was determined and the mechanism of the transitions was described. Schemes were proposed for the phase transitions that take into account the conditions of fabrication and thermal history of the samples. Translated from Khimicheskie Volokna, No. 5, pp. 24–27, September–October, 1998.