91 research outputs found
Thermal Performance of Hollow Clay Brick with Low Emissivity Treatment in Surface Enclosures
External walls made with hollow clay brick or block are widely used for their thermal, acoustic and structural properties. However, the performance of the bricks frequently does not conform with the minimum legal requirements or the values required for high efficiency buildings, and for this reason, they need to be integrated with layers of thermal insulation. In this paper, the thermal behavior of hollow clay block with low emissivity treatment on the internal cavity surfaces has been investigated. The purpose of this application is to obtain a reduction in the thermal conductivity of the block by lowering the radiative heat exchange in the enclosures. The aims of this paper are to indicate a methodology for evaluating the thermal performance of the brick and to provide information about the benefits that should be obtained. Theoretical evaluations are carried out on several bricks (12 geometries simulated with two different thermal conductivities of the clay), using a finite elements model. The heat exchange procedure is implemented in accordance with the standard, so as to obtain standardized values of the thermal characteristics of the block. Several values of emissivity are hypothesized, related to different kinds of coating. Finally, the values of the thermal transmittance of walls built with the evaluated blocks have been calculated and compared. The results show how coating the internal surface of the cavity provides a reduction in the thermal conductivity of the block, of between 26% and 45%, for a surface emissivity of 0.1
The Contribution of the ITACA Protocol in the Control of the Environmental Quality in Residential Buildings and the Subsequent Contribution to the Adaptation to Climatic Change
Abstract During the last years the aim to reduce environmental impacts in the building sector has led to the development of assessment methods called protocols, to certify the sustainable quality of the building, such as the ITACA Protocol. In the present work the national version 2011 of the ITACA Protocol has been applied to several residential buildings study cases, and the resulting performances have been compared with a reference building with the same geometric shape and performances within the limit of the law. These results have been compared with the average energy performance of an Italian residential estate, to evaluate the contribution to climate change adaption. Furthermore, the comparison has also been carried out from the costs point of view, to verify the necessity of long-term subsidizing policies. The criteria used to analyze the effective impact reduction are: primary energy for heating and hot water and related CO2 emissions. The average value of savings in energy consumption obtained in the evaluated building (designed and certified with the ITACA Protocol, compared to reaching the law limit value) is 51.25 kWh/m 2 ·y, with corresponding 8.52 kg CO2/m2·y emissions saved. Intervening on 22% of the current Italian housing estates with the performances of the study cases, results in a reduction of the energy load of 20.10%. Whilst from the technical point of view the application could be easily adopted, the high costs of these interventions still have a long payback period, and it could be necessary to provide a durable public incentive
Evaluation of energy conservation opportunities through Energy Performance Contracting: A case study in Italy
Non-residential buildings like healthcare ones contribute to energy consumption and cause a negative environmental impact. This is mainly due to the age of the buildings, their poor level of energy efficiency and the implementation of only a basic maintenance plan. Owing to the very limited budget available for public administrators, Energy Performance Contracting (EPC), that entails the involvement of an Energy Service Company (ESCo), can provide the entire or part of the capital needed for investments aimed at progressively increasing energy efficiency over their service life. In this paper, three acute hospitals and two community clinics built in Italy are analysed, in order to assess the economic feasibility of several energy renovation actions that can be included within EPC contracts. To this purpose, the outcomes of energy audits carried out in 2014 about these buildings are reported, which involved analyses of consumption measured over the previous three years and assessment of use profiles for the development of models to break down the overall consumption and to estimate potential savings. Diverse improvement strategies were assessed, consisting in either isolated or combined renovation actions and tested on the five buildings, whose comparison was carried out in terms of energy saving, pollution reduction and economic feasibility. As a result, the best combined renovation actions per each hospital were recommended, that included - but were not limited to - the improvement of the control and regulation of existing sub-systems without replacement, partial replacement of other sub-systems and integration of renewables. Finally, each scenario was evaluated through the payback period and other economic performance indexes in order-to assess the feasibility of the EPC framework when applied to this case study
Managing Energy Retrofit of Acute Hospitals and Community Clinics through EPC Contracting: The MARTE Project
Abstract Acute hospitals and community clinics contribute to energy consumption and have a negative environmental impact. This is mainly due to the age of the buildings, a poor level of energy efficiency and a basic maintenance plan. Owing to the very limited money available for public administrators, Energy Performance Contracting (EPC), involving an Energy Service Company (ESCo), can provide the capital needed for investments aimed at increasing energy efficiency. In this paper three acute hospitals and two community clinics in Italy are analyzed prior to EPC development in order to assess the economic feasibility of retrofit strategies. The outcome of energy audits carried out in 2014, the analyses of consumption measured over the last 3 years, and the assessment of use profiles were all considered for the development of models to break down the overall consumption and to assess potential savings. Recommended improvement strategies include better insulation in envelopes, enhancement of mechanical and lighting equipment, use of renewable energy, better regulation of systems. Finally, payback periods for the most likely scenarios were evaluated
Yield and stability of safflower varieties (Carthamus tinctorius L.) in the Semiarid Pampean Region
El cultivo de cártamo se realiza actualmente en el noroeste de la Argentina, aunque el área más apta para el mismo es la Región Pampeana Central Semiárida. Se estudió el comportamiento de diferentes variedades en distintos ambientes para determinar aquellas capaces de producir un rendimiento más estable y productivo, para ser utilizadas en programas de difusión del cultivo en esa región. A tal fin se efectuaron seis ensayos comparativos de rendimiento en dos localidades: Santa Rosa (La Pampa, 36° 39 ’S, 64° 16 ’O) y Tres Picos (Buenos Aires, 38° 16’ S, 62° 13’ O), durante varios años. Para el estudio de la estabilidad del rendimiento se utilizó el análisis de los rendimientos relativos. Las variedades S-541, S-200 y S-400 fueron las más estables y las de mayor rendimiento en grano y aceite.Safflower production is mainly concentrated in northwestern Argentina although the most suitable area for its production is the central, Semiarid Pampean Region. The response of different varieties able to produce high sustainable yields was studied under different environments, with the idea of promoting these varieties in the study region. Six variety trials were carried out at two locations in the study area, Santa Rosa (La Pampa, 36° 39’ S, 64° 16’ W) and Tres Picos (Buenos Aires, 38° 16’ S, 62° 13’ W), during several years. Relative yield was used as a measure of safflower stability. Varieties S-541, S-200 and S-400 were the most stable and showed the highest grain and oil yields.Fil: Mirassón, H.R.. Universidad Nacional de La Pampa. Facultad de AgronomÃa; ArgentinaFil: Palomo, Iris Rosana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Brevedan, Roberto. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; ArgentinaFil: Fioretti, Maria Nelida. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiarida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiarida; Argentin
Allelopathic effect of Baccharis ulicina on germination and initial growth of Avena sativa, Lolium perenne and Raphanus sativus
Baccharis ulicina es una maleza ampliamente
distribuida en los pastizales de la zona semiárida
argentina. A fin de evaluar sus posibles efectos
alelopáticos, se utilizaron extractos acuosos de
B. ulicina (hoja, tallo, raÃz y planta entera) a dos
concentraciones (50 y 150 g tejido/L agua) sobre
la germinación y crecimiento inicial de Avena
sativa, Lolium perenne y Raphanus sativus.
Para cada especie se regaron 100 semillas y se
mantuvieron a 25°C y oscuridad. Se registraron
la germinación de las semillas y la longitud de
coleóptilo / hipocótile (C/H) y radÃcula (R). Con
los datos obtenidos se determinó: porcentaje
de germinación, coeficiente de velocidad de
germinación, vigor de la germinación, inhibición
de la germinación, inhibición de la longitud de
la radÃcula y del coleóptilo / hipocótile e Ãndice
de vigor de radÃcula y de coleóptilo / hipocótile.
Los extractos con alta concentración redujeron
la germinación en promedio 65% mientras que
inhibieron la longitud en 58,8% (C/H) y 93,3% (R)
para A. sativa; 71,5% (C/H) y 87,9% (R) para
L. perenne, y 93,8% (C/H) y 94,5% (R) para
R. sativus. Se registró un evidente efecto fitotóxico
de B. ulicina sobre las especies evaluadas,
indicando que la alelopatÃa serÃa una estrategia
ecológica de la especie.Baccharis ulicina is a weed widely distributed
in pastures of the semiarid zone of Argentina.
With the aim of evaluate potential allelopathic
effects, aqueous extracts of B. ulicina (leaf, stem,
root and whole plant) at two concentrations
(50 and 150 g tissue/L water) were used on
germination and initial growth of Avena sativa,
Lolium perenne and Raphanus sativus. For each
species, 100 seeds were watered and maintained
at 25°C at darkness. Seed germination and length
of coleoptile / hypocotyl (C/H) and radicle (R)
was measured. Then, germination percentage,
germination rate coefficient, germination vigor,
inhibition of germination, inhibition of radicle
length and coleoptile / hypocotyl length, radicle
vigor index and the coleoptile / hypocotyl vigor
index were calculated. High concentration
extracts reduced germination an average of 65%,
in addition, they produced a length inhibition
of 58.8% (C/H) and 93.3% (R) to A. sativa;
71.5% (C/H) and 87.9% (R) to L. perenne, and
93.8% (C/H) and 94.5% (R) to R. sativus. There
was an evident phytotoxic effect of B. ulicina on
evaluated species, indicating that allelopathy
would be an ecological strategy of the species.Fil: Tucat, Guillermo.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Bentivegna, Diego.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Fernández, Osvaldo.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Busso, Carlos.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Brevedan, Roberto.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Mujica, MarÃa de la Merced.Fil: Torres, Yanina.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Daddario, Juan.
Centro de Recursos Naturales Renovables de la Zona Semiárida (Buenos Aires, Argentina).Fil: Ithurrart, Leticia.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: Giorgetti, Hugo.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: RodrÃguez, Gustavo.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: Montenegro, Oscar.
Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental Patagones.Fil: Baioni, Sandra.
Universidad Nacional del Sur. Departamento de AgronomÃaFil: EntÃo, José.Fil: Fioretti, MarÃa Nélida.
Universidad Nacional del Sur. Departamento de AgronomÃ
Phosphorus nutrition on nitrogen metabolism of non-nodulated soybean
Se realizaron dos experimentos en el invernáculo para estudiar la influencia de la deficiencia de P en la nutrición con nitrógeno de plantas de soja no nodulada. Hubo una reducción en el contenido de N y P en las plantas deficientes en P (P-) de casi el 50% y del 33% en la materia seca, luego de 50 dÃas. La actividad de la nitrato reductasa y el contenido de nitratos en tallos fueron menores en plantas P- que en aquellas P+. Del total de nitratos en las plantas P-, 75% estuvo en las raÃces. La acumulación de nitratos en las raÃces serÃa debido a la menor actividad de la nitrato reductasa en las mismas, y a una disminución en el flujo de agua hacia el vástago. El incremento en la concentración de nitratos en la raÃz causarÃa una retroalimentación negativa que reducirÃa su absorción por la planta.Two experiments were conducted under greenhouse conditions to study the influence of P deficiency on nitrogen nutrition of non-nodulated soybean. There was a reduction of N and P content in P deficient (P-) plants of almost 50% after 50 days. During this period, dry matter of these plants was reduced by 33%. Nitrate reductase activity and shoot nitrate content were lower in Pthan in P+ plants. Seventy five percent of nitrates in P- plants were in the roots. Nitrate accumulation in roots would be due to the lower nitrate reductase activity in this organ and a reduced water flux to shoots. Root nitrate concentration increases would cause a negative feedback which would reduce plant nitrate uptake.Fil: Brevedan, Roberto. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Aveldaño, Marta Isabel. Universidad Nacional del Sur; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Fioretti, Maria Nelida. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Varillas, MarÃa Alejandra. Universidad Nacional del Sur. Departamento de BiologÃa, BioquÃmica y Farmacia. Cátedra de Control de Calidad de Medicamentos; ArgentinaFil: Baioni, Sandra Sonia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; ArgentinaFil: Mirasson, H. R.. Universidad Nacional de la Pampa. Facultad de Agronomia. Cátedra de FisiologÃa Vegetal; ArgentinaFil: Palomo, Iris Rosana. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida. Universidad Nacional del Sur. Centro de Recursos Naturales Renovables de la Zona Semiárida; Argentin
Water stress and temperature effects on germination and early seedling growth of Digitaria eriantha
This study focused on the two major processes critical for plant establishment: Seed germination and seedling survival. We determined the effects of (1) water stress and temperature on the germination, and (2) water stress on early seedling growth of Digitaria eriantha cv ‘Irene’. Seeds harvested in 2007 were used for temperature studies, and those coming from 2006 and 2007 for water stress studies. In 2009, viability decreased by 65.4% from 2006 to 2007. During the first twenty-four hours, germination was more than 50% at constant (30 or 35°C) than alternating (10/30 or 10/35°C) temperatures, although total germination was about 80% for all temperature treatments. Polyethylene glycol 8000 was used to impose water stress conditions. Germination percentages and coefficients of velocity decreased with decreasing water potentials. Early seedling growth was smaller at lower water potentials. D. eriantha cv ‘Irene’ appeared to germinate within a wide range of temperatures, but it varied greatly in germination response to water potentials. Results suggest that this species could be planted in late spring-early summer, when seedbed temperatures are increasing and soil moisture might still be adequate.Fil: Brevedan, Roberto. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentina. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Busso, Carlos Alberto. Universidad Nacional del Sur. Departamento de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: Fioretti, M. N.. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Toribio, M. B.. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Baioni, S. S.. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Torres, Yanina Alejandra. Universidad Nacional del Sur. Departamento de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: Fernandez, Osvaldo Alberto. Universidad Nacional del Sur. Departamento de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: Giorgetti, H. D.. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Bentivegna, Diego Javier. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); ArgentinaFil: EntÃo, J.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: Ithurrart, Leticia Soledad. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentina. Universidad Nacional del Sur. Departamento de AgronomÃa; ArgentinaFil: Montenegro, O.. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Mujica, M. de las M.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales; ArgentinaFil: RodrÃguez, G.. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios. Chacra Experimental de Patagones; ArgentinaFil: Tucat, Guillermo. Universidad Nacional del Sur. Departamento de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico BahÃa Blanca. Centro de Recursos Naturales Renovables de la Zona Semiárida(i); Argentin
Plant growth and survival of five introduced and two native/naturalized perennial grass genotypes exposed to two defoliation managements in arid Argentina
The field performance of the native Pappophorum vaginatum, the naturalized Eragrostis curvula and various cultivars of the introduced Achnatherum hymenoides and Leymus cinereus was evaluated as potential forage resources in rangelands of arid Argentina during the warm seasons of 2007/2008 and 2008/2009. Plants of these grass species, obtained from seeds, were transplanted to the field in 2006, when they were 1 year old. During the study years, there were two defoliation managements: plants of all study genotypes either remained undefoliated (controls) or were defoliated twice a year during spring at 5 cm stubble height. Despite tiller number being lower (P 0·05) between defoliation managements by mid-spring, there were no differences (P > 0·05) in dry weight production between defoliated and undefoliated plants in all genotypes at the end of the second growing season. Plants of one or more of the introduced genotypes showed a similar (P > 0·05) or greater (P 0·05) or greater (P 70%) or naturalized (>39%) genotypes at the end of the first or second growing seasons.Facultad de Ciencias Agrarias y Forestale
Root proliferation in native perennial grasses of arid Patagonia, Argentina
Pappophorum vaginatum is the most abundant C4 perennial grass desirable to livestock in rangelands of northeastern Patagonia, Argentina. We hypothesized that (1) defoliation reduce net primary productivity, and root length density and weight in the native species, and (2) root net primary productivity, and root length density and weight, are greater in P. vaginatum than in the other, less desirable, native species (i.e., Aristida spegazzinii, A. subulata and Sporobolus cryptandrus). Plants of all species were either exposed or not to a severe defoliation twice a year during two growing seasons. Root proliferation was measured using the cylinder method. Cylindrical, iron structures, wrapped up using nylon mesh, were buried diagonally from the periphery to the center on individual plants. These structures, initially filled with soil without any organic residue, were dug up from the soil on 25 April 2008, after two successive defoliations in mid-spring 2007. During the second growing season (2008–2009), cylinders were destructively harvested on 4 April 2009, after one or two defoliations in mid-and/or late-spring, respectively. Roots grown into the cylinders were obtained after washing the soil manually. Defoliation during two successive years did reduce the study variables only after plants of all species were defoliated twice, which supported the first hypothesis. The greater root net primary productivity, root length density and weight in P. vaginatum than in the other native species, in support of the second hypothesis, could help to explain its greater abundance in rangelands of Argentina.Facultad de Ciencias Agrarias y Forestale
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