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A method for increasing the volume of a cylinder with minimal area preserving the isometry is expounded. To do this, it was necessary to use numerical methods and a computer program. Such method let us set down a theorem which is analogy to that given for the case of a cube instead of a cylinder, being an immediate application of this theorem to the case of optimization in designing commercial bottles. To get an analytical proof of this new theorem is demanded. Keywords: surface of minimal area; optimization in designing commercial bottles; increasing the volume without stretching.

From the stems of the Cinchona pubescens, wich were collected in the locality Yuracmallo (Province of Sandia, Puno), quinine was obtained, wich was identified by the mass spectra, RMN1H, RMN13C y 1H-1H COSY. Furthermore, the qualitative analysis of the secondary metabolites was done.

Contenido

iP cores (intellectual Property cores) are for hardware design what libraries are for computer programming. They are typically used in the style and form of a discrete integrated circuit, where the “circuit board” is a larger design in asic or FPGa. a core intellectual property often takes the form of a software program written in hDl such as verilog, vhDl or systemc. ideally, an iP-core must be fully portable, meaning that it can be easily adapted to any technology from other suppliers or different design methods. receivers/transmitters universal asynchronous (uart), central Processing units (cPu), ethernet controllers, interfaces Pci are examples of iP-cores. This paper presents the adaptation of a 16-channel PWm iPcore to a separate brick structure similar to soc (system on chip). We did not implement a microprocessor as master of the system, instead a complex state machine runs a bus in order to save resources in the FPGa. This complex state machine that acts as the controller of the system is within a provision which is called sba (single bus architecture), which is just a simplification of the signals and rules establishing the Wishbone specification. The system thus allows the configuration of 16 independent PWm digital outputs in low ripple mode. While the example presented in this work shows a single PWm iPcore instantiated this is not a limit. The implemented PWm core does not use specific or special resources of the FPGa, which allows that the number of instantiated blocks can grow as much as configurable generic blocks in the FPGa become available. That is, for each instantiated core there will be 16 independent PWm channels that will have specific preset positions within the address map of the sba.

The present research was developed in the laboratory of meat unas. The aims were to determine the capacity of water retention and the ph in fresh meat (cra), defrosted (crad), and cooked (crac), at different temperatures in the meat of beef, pork, chicken, sheep, rabbit and paco fish. as well as to produce sausage with the meat that has better water retention capacity and to evaluate the emulsion stability (ee) and capacity of water retention of the sausage (crae). We analyzed the capacity of water retention in fresh meat, defrosted and cooked (at 77, 82 and 87 °c). The data was expressed by the media ± sem, we used variance analyses of complete design at random (Dca) and the tukey test (p<0,05). The best capacity of water retention in fresh meat corresponded to paco fish cra i (25 %) and cra ii (17,333 %) and Ph (6,39), in defrosted meat corresponded to sheep crad (0,357 %) and ph (5,133), in cooked meat at 77 °c temperature corresponded to chicken crac (6,62 %) and ph (5,76), and at 82 °c and 87 °c corresponded to sheep crac (9,31 and 18,953 % respectively) and ph (5,75 y 5,78 respectively). We also carried out the analyses of emulsion stability and the capacity of water retention of the sausages of pork and sheep. The data were expressed by the media ± sem, We used the test of t - student (p<0,05). The best emulsion stability (ee) and capacity of water retention (crae) corresponded to the sausage elaborated with pork ee (8,53 ml/100g of meat) and crae (25 %).

in this research we show an analysis of cylindrical parabolic solar collectors (cPc), which were improved through incorporation of reflective mirrors, thus increasing their efficiency. similarly added a light monitoring system, based on photosensors, so we can maximize every sunbeam. as a first approximation it was assumed that the solar collector works as a perfect black body. Then we propose a more realistic model, where it takes into account the heat losses, dissipation of the solar rays, the optical properties of materials used, etc. in the experimental part, this system was assembled, and was compared with traditional systems of cPc. The principal result was a marked improvement in the temperature for the receiver tube in a shorter time of exposure. also, we show applications of this type of collectors, ranging from domestic heating systems, improving production anaerobic fermentation, to thermal power plants for generating electricity. in the end, we show proposals for the improvement of this system according to theoretical investigation.

The present investigation had the purpose of: determining the differences in the in vitro development of buds from croton young plants of latex producers; to evaluate the response to the acclimatization of croton’s plantulas with better behavior in vitro, and to determine the chromosomal number of selected individuals of croton latex producers. The culture medium for the in vitro introduction was determined evaluating the behavior of croton draconoides in five treatments with the basic medium murashige and skoog (ms) taking into consideration that the species in the study belong to the same gender. The buds coming from croton young plants producers of wine latex had the best behavior in the selected culture medium (ms + 0,01mg/i ana + 0,1mg/i of baP and aG3 + 20 ml of coconut water) presenting an increase in height, number of leaves and percentage of survival in relationship to croton producers of red and ocher latex. The plantulas of croton producers of wine latex, previously rooted in vitro, were taken for acclimatization. Four substrates were tested, determining that the response of the plantulas changes according to the substrate composition, watering conditions (nebulization), fungus control (benlate to 0,1%) and the application of the bioestimulant biogen 1 to 0,1%. The chromosomal number determined in plants of the gender croton producers of red, wine and ocher latex was of 40.

The events el niño and la niña in the tropical Pacific ocean occur periodically over time and have a clear incidence on growth and maintenance of the glacier surface of snow-capped mountains. The behaviour of the glacier surfaces of two snowy tropicals, the Pastoruri and the huandoy, located in the cordillera blanca of Perú were studied in the years when the events el niño and la niña occurred. This study was done applying a multifractal technique, the method of box counting, the normalized difference snow index nDsi and the relationship of bands of satellital images 3/5. multifractals modern techniques became very versatile, practical and sensitive in showing the impact of el niño and la niña in the multifractal spectral and for the estimation of glacier surface. The huandoy and Pastoruri decrease in average glacier surface was 10% in the last 22 years. The estimation of glacier surface for the conventional or multifractal methods was not significantly different in analysis such as related samples, which means that there is no distinction when using the siG or multifractals for determining the glacier area. The dimension D0 for the glacier surface was 1,8.

The present work aims to develop a Dc voltage output regulated with a topology called voltage Drop Diode unit (vDDu). The system is composed of two parts: a power circuit, and a signal processing circuit. The power board contains the responsible circuits to supply the contactor and the signal processing control board. The conditioned signals are processed in a micro-controller. The objective of the system is to maintain the voltage supply around 125 vDc +/- 4%, for a power of 25kW. Thereby supplying a PbaX telecommunication system that is isolated of the electrical network distribution with a battery array. The firmware was developed in the mPlab environment for the micro-controller 18F6620. The obtained results show that the proposed system is satisfactory and that it also presents a lower economic cost of implementation than the existent converter topologies.

The work presents an application case of a versatile platform based on FPGa that has been validated, its architecture makes possible its reuse and promotes the exchange of the firmware and software that transform it in diverse laboratory electronic instruments. This paper describes an instrument that allows the characterization of semiconductor devices by means of its “i vs. v” curve. a board named rvi (reconfigurable virtual instrument) developed at the mlab of the international centre for Theoretical Physics and a signal adapter board makes the hardware of the system while the software was developed using lazarus. The code to configure the FPGa was making using vhDl. This design is intended to contribute to the rvi project initiated by the ictP in 2006, with developing a virtual instrument in this platform.