Estudio de factibilidad de sistemas híbridos eólico-solar en el Departamento de Moquegua

El uso de energías renovables en cualquier lugar de nuestro país requiere tener información actualizada sobre las características y operación de las alternativas de equipos que se pueden instalar. También es muy importante el conocer si existe o no recurso disponible en el lugar donde se planea realizar la instalación Actualmente en nuestro país sólo existen datos confiables respecto del recurso solar, tal vez este hecho ha influido en que la energía solar sea la que más aceptación tenga en nuestro medio, sin embargo existe también energía del viento que puede y debe ser aprovechada. En este trabajo se realiza un estudio de las características de salida de energía que tendría un sistema híbrido (solar–eólico) en la localidad de Ilo. Se escoge este lugar debido a que se cuenta con datos precisos de viento (velocidad y dirección) proporcionados por la Municipalidad Provincial de Ilo, asimismo se tienen disponible los datos de radiación solar y con ello es posible realizar un estudio preciso sobre la salida de energía del sistema. Para lograr esto se desarrolla en los primeros capítulos la metodología que permite hacer el tratamiento estadístico de los datos con que se cuenta. Teniendo como base un ejemplo hipotético, pero bastante realista, de consumo de energía en una localidad rural se establecen la demanda de energía que se requiere para satisfacer necesidades básicas de luz y agua. Finalmente y estableciendo a partir de las alternativas que ofrece el mercado, la configuración del sistema solar–eólico, se puede conocer la energía que es capaz de suministrar el sistema y hacer la comparación con la alternativa de grupo electrógeno la cual es una de las más utilizadas en nuestro país para suministrar energía en situaciones de aislamiento.Tesi

Seasonal patterns and controls on net ecosystem CO2 exchange in a boreal peatland complex

We measured seasonal patterns of net ecosystem exchange (NEE) of CO2 in a diverse peatland complex underlain by discontinuous permafrost in northern Manitoba, Canada, as part of the Boreal Ecosystems Atmosphere Study (BOREAS). Study sites spanned the full range of peatland trophic and moisture gradients found in boreal environments from bog (pH 3.9) to rich fen (pH 7.2). During midseason (July‐August, 1996), highest rates of NEE and respiration followed the trophic sequence of bog (5.4 to −3.9 μmol CO2 m−2 s−1) \u3c poor fen (6.3 to −6.5 μmol CO2 m−2 s−1) \u3c intermediate fen (10.5 to −7.8 μmol CO2 m−2 s−1) \u3c rich fen (14.9 to −8.7 μmol CO2m−2 s−1). The sequence changed during spring (May‐June) and fall (September‐October) when ericaceous shrub (e.g., Chamaedaphne calyculata) bogs and sedge (Carex spp.) communities in poor to intermediate fens had higher maximum CO2 fixation rates than deciduous shrub‐dominated (Salix spp. and Betula spp.) rich fens. Timing of snowmelt and differential rates of peat surface thaw in microtopographic hummocks and hollows controlled the onset of carbon uptake in spring. Maximum photosynthesis and respiration were closely correlated throughout the growing season with a ratio of approximately 1/3 ecosystem respiration to maximum carbon uptake at all sites across the trophic gradient. Soil temperatures above the water table and timing of surface thaw and freeze‐up in the spring and fall were more important to net CO2 exchange than deep soil warming. This close coupling of maximum CO2 uptake and respiration to easily measurable variables, such as trophic status, peat temperature, and water table, will improve models of wetland carbon exchange. Although trophic status, aboveground net primary productivity, and surface temperatures were more important than water level in predicting respiration on a daily basis, the mean position of the water table was a good predictor (r2 = 0.63) of mean respiration rates across the range of plant community and moisture gradients. Q10 values ranged from 3.0 to 4.1 from bog to rich fen, but when normalized by above ground vascular plant biomass, the Q10 for all sites was 3.3

Objectifying Acupuncture Effects by Lung Function and Numeric Rating Scale in Patients Undergoing Heart Surgery

Rationale. Poststernotomy pain and impaired breathing are common clinical problems in early postoperative care following heart surgery. Insufficiently treated pain increases the risk of pulmonary complications. High-dose opioids are used for pain management, but they may cause side effects such as respiratory depression. Study Design. We performed a prospective, randomized, controlled, observer-blinded, three-armed clinical trial with 100 patients. Group 1 (n=33) and Group 2 (n=34) received one 20 min session of standardized acupuncture treatment with two different sets of acupoints. Group 3 (n=33) served as standard analgesia control without additional intervention. Results. Primary endpoint analysis revealed a statistically significant analgesic effect for both acupuncture treatments. Group 1 showed a mean percentile pain reduction (PPR) of 18% (SD 19, P<0.001). Group 2 yielded a mean PPR of 71% (SD 13, P<0.001). In Group 1, acupuncture resulted in a mean forced vital capacity (FVC) increase of 30 cm3 (SD 73) without statistical significance (P=0.303). In Group 2, posttreatment FVC showed a significant increase of 306 cm3 (SD 215, P<0.001). Conclusion. Acupuncture revealed specific analgesic effects after sternotomy. Objective measurement of poststernotomy pain via lung function test was possible