An Innovative Enhanced Wall to Reduce the Energy Demand in Buildings

Energy saving in buildings is one of most important issues for European countries. Although in the last years many studies have been carried out in order to reach the zero-consumption house the energy rate due to passive solar heating could be further enhanced. This paper proposes a method for increasing the energy rate absorbed by opaque walls by using a two phase loop thermosyphon connecting the internal and the external façade of a prefabricated house wall. The evaporator zone is embedded into the outside facade and the condenser is indoor placed to heat the domestic environment. The thermosyphon has been preliminary designed and implanted into a wall for a prefabricated house in Italy. An original dynamic thermal model of the building equipped with the thermosyphon wall allowed the evolution of the indoor temperature over time and the energy saving rates. The transient behaviour of the building has been simulated during the winter period by using the EnergyPlusTM software. The annual saving on the heating energy is higher than 50% in the case of a low consumption building

FLAT PLATE PULSATING HEAT PIPES WITH DIFFERENT CHANNEL GEOMETRIES FOR HIGH HEAT FLUX APPLICATIONS

The thermal performance of flat plate pulsating heat pipes with differentchannel geometries was performed in this experimental work. The testswere accomplished with two channel profiles, round and grooved. One ofthe channel geometries, located on the evaporator, can be considered novel,consisting of a round channel with two lateral grooves. Diffusion bondingtechnology was used to manufacture the PHPs made of two copper flatplates. Distilled water was used as the working fluid with a filling ratio of50% (17.9 ml) of the total volume. The pulsating heat pipes were tested atone position (vertical) under heat loads from 20 up to 2000 W. Theexperimental results showed that both flat plate pulsating heat pipesoperates successfully for high heat fluxes. The lateral grooves reduced thethermal resistance, being principally efficient in lower loads. Besides that,the novel channel considerably anticipated the operation startup. Therefore,a much better performance was obtained by the grooved channel PHP,which was constructed from a simple, low cost modification of thefabrication process

An Innovative Enhanced Wall to Reduce the Energy Demand in Buildings

Energy saving in buildings is one of most important issues for European countries. The 40% of the total European energy consumption is due to building Heating and conditioning. Although in the last years many studies have been carried out in order to reach the zero-consumption house by means of passive solar heating, ventilation or thermal insulation, the energy rate due to passive solar heating could be further enhanced. This paper proposes a method for increasing the energy rate absorbed by opaque walls by using a two phase loop thermosyphon connecting the internal and the external façade of a prefabricated house wall. The evaporator zone is located on the outside face and it is irradiated by the sunlight while the condenser zone is placed on the internal face and releases heat to the domestic environment. The temperature differences between the internal and external wall facades are lower than 30 K and the heat fluxes at the evaporator change during the day from 2 up to 7 x 104 W/m2 K. The thermosyphon has been preliminary designed and implanted into a wall for a prefabricated house in Italy. A thermal model of building equipped with the thermosiphon wall has been used in order to evaluate the impact in terms of energy saving and thermal comfort in a real prefabricated low consumption house. The transient behaviour of the building has been simulated day by day during the winter period by using the EnergyPlusTM software. This solution enhances the thermal comfort of the building by keeping the indoor temperature close to the thermal comfort standard for most of the day. The annual saving on the heating energy is higher than 50% in the case of a low consumption buildin

Nature of the global fluctuations in the spherical model at criticality

We study the universal nature of global fluctuations in the critical regime of the spherical model by evaluating the exact distribution of the magnetization and its absolute value in the thermodynamical limit, in the presence of a conjugate field. We show that the probability distribution function for this model is described by non-Gaussian asymptotics and non-symmetric characteristics which depend on the dimension of the system 2<d<4. Relation with extreme statistics of independent wavelength modes is discussed.Comment: 22 pages, 8 figures; 05.70.Jk, 05.40.-a, 05.50.+q, 68.35.R

Treatment of ocular allergies:nonpharmacologic, pharmacologic and immunotherapy

Ocular allergy is a significant and growing issue worldwide but for many patients, it is often not differentiated from systemic conditions, such as hay fever. Management of seasonal and perennial allergic conjunctivitis is often poor. Management is principally through avoidance measures (blocking or hygiene), nonpharmaceutical (such as artificial tears and cold compresses) and pharmaceutical (such as topical antihistamines and prophylactic mast cell stabilizers). Vernal and atopic keratoconjunctivitis are more severe and generally need treatment with NSAIDs, steroids and immunomodulators. Giant papillary conjunctivitis can be related to allergy but also is often contact lens related and in such cases can be managed by a period of abstinence and replacement of the lens or a change in lens material and/or design. Immunotherapy can be efficacious in severe, persistent cases of contact lens or allergic conjunctivitis

General practitioners' deprescribing decisions in older adults with polypharmacy: a case vignette study in 31 countries

BACKGROUND: General practitioners (GPs) should regularly review patients' medications and, if necessary, deprescribe, as inappropriate polypharmacy may harm patients' health. However, deprescribing can be challenging for physicians. This study investigates GPs' deprescribing decisions in 31 countries. METHODS: In this case vignette study, GPs were invited to participate in an online survey containing three clinical cases of oldest-old multimorbid patients with potentially inappropriate polypharmacy. Patients differed in terms of dependency in activities of daily living (ADL) and were presented with and without history of cardiovascular disease (CVD). For each case, we asked GPs if they would deprescribe in their usual practice. We calculated proportions of GPs who reported they would deprescribe and performed a multilevel logistic regression to examine the association between history of CVD and level of dependency on GPs' deprescribing decisions. RESULTS: Of 3,175 invited GPs, 54% responded (N = 1,706). The mean age was 50 years and 60% of respondents were female. Despite differences across GP characteristics, such as age (with older GPs being more likely to take deprescribing decisions), and across countries, overall more than 80% of GPs reported they would deprescribe the dosage of at least one medication in oldest-old patients (> 80 years) with polypharmacy irrespective of history of CVD. The odds of deprescribing was higher in patients with a higher level of dependency in ADL (OR =1.5, 95%CI 1.25 to 1.80) and absence of CVD (OR =3.04, 95%CI 2.58 to 3.57). INTERPRETATION: The majority of GPs in this study were willing to deprescribe one or more medications in oldest-old multimorbid patients with polypharmacy. Willingness was higher in patients with increased dependency in ADL and lower in patients with CVD

How a wall thermosyphon can enhance the energy savings in a prefabricated house in Italy

Energy saving in buildings is one of most important issue for European countries. The energy consumption rate devoted to building is about the 40% with respect the total European energy consumption. Although in the last years many studies have been carried out in order to reach the zero-consumption house by means of passive solar heating, ventilation or thermal insulation, the energy rate due to passive solar heating could be further enhanced. This paper proposes a method to increase the energy rate coming from the solar opaque elements by using a two phase loop thermosyphon to connect the internal and the outside façade of prefabricated house wall. The evaporator zone is located on the outside side of the wall and it is irradiated by the sunlight while the condenser zone is placed on the internal side of the wall and releases heat to the domestic environment. The temperature differences between the internal and outside wall facades are lower than 30 K) and the heat fluxes at the evaporator changes during the time range from 2 to 7 x 104 W/m2 K. The thermosyphon has been preliminary designed and implanted into a wall for a prefabricated house in Italy. A thermal model of building with the wall enhanced by the wall thermosyphon has been used to evaluate the impact of this solution in terms of energy saving and thermal comfort in a real prefabricated low consumption house. The transient behavior of the building has been simulated day by day during the winter period by using the EnergyPlusTM software. This solution enhances the thermal comfort of the building by keeping the indoor temperature close to the thermal comfort standard for the most of the day. The annual heating energy demand saving rate is higher than 23% in the case of a low consumption building. These rates reach the maximum of 38.8% in the case of a hous

Line-pack management for producing electric power on peak periods

The distribution of natural gas is carried out by means of long ducts and intermediate compression stations to compensate the pressure drops due to friction. The natural gas compressors are usually driven by an electric motor or a gas turbine system, offering possibilities for energy management, one of these consisting in generating energy for use in-plant or to commercialize as independent power producer. It can be done by matching the natural gas demand, at the minimum pressure allowed in the reception point, and the storage capacity of the feed duct with the maximum compressor capacity, for storing the natural gas at the maximum permitted pressure. This allows the gas turbine to drive an electric generator during the time in which the decreasing pressure in duct is above the minimum acceptable by the sink unit. In this paper, a line-pack management analysis is done for an existing compression station considering its actual demand curve for determining the economic feasibility of maintaining the gas turbine system driver generating electricity in a peak and off-peak tariff structure. The potential of cost reduction from the point of view of energy resources (natural gas and electric costs) is also analyzed. (C) 2010 Elsevier Ltd. All rights reserved