The freeze-thaw(FT)behavior of porous materials(PMs)involves the coupling of the thermo-hydromechanical(THM)processes and is significantly influenced by the microstructure.However,modeling FT in unsaturated PMs remain...The freeze-thaw(FT)behavior of porous materials(PMs)involves the coupling of the thermo-hydromechanical(THM)processes and is significantly influenced by the microstructure.However,modeling FT in unsaturated PMs remains an open issue,and the influence of microstructure is not yet fully understood.To address these challenges,we propose a THM model for FT in PMs that considers microstructure and variable air content.In this work,a non-equilibrium thermodynamic approach is proposed to capture ice formation/melting,the microstructure is accounted for utilizing micromechanics,and the FT processes in air-entrained PMs are formulated within the proposed THM model.This model incorporates variable air void characteristics,e.g.air content,spacing factor,specific surface area,and supercooled water-filled regimes,and distinguishes the roles of air voids between freezing and thawing.The FT behaviors,including deformation,ice formation/melting,spacing factor,and pore water pressure evolutions,are focused.Comparisons with experimental results,confirm the capability of the present model.The results demonstrate the effects of variable air voids on the FT behavior of air-entrained PMs.The findings reveal that assuming fixed air void characteristics can lead to underestimation of pore pressure and deformation,particularly at low air content.Additionally,air voids act as cryo-pumps during freezing and when the cooling temperature stabilizes.During thawing,air voids supply gas to the melting sites(i.e.“gas escape”),preventing further significant deformation reduction.These results can provide novel insights for understanding the frost damage of PMs.展开更多
With 1 185 pi eces of questionnaire, it is found that in China, people take fresh air, odor, e tc., as well as indoor air temperature, humidity, as the most important indoor a ir parameters. It is also found that ther...With 1 185 pi eces of questionnaire, it is found that in China, people take fresh air, odor, e tc., as well as indoor air temperature, humidity, as the most important indoor a ir parameters. It is also found that there is a significant sensitivity differen ce in indoor environment between southerners and northerners in China. People fr om different regions have different demands for their working and living environ ment. Therefore, as a good design of air conditioning system, it is strongly rec ommended that the different demands of people from different regions should be t aken into consideration.展开更多
The marine sediments of the area of Verde Peninsula - Jabali Island （39°28＇S/62°19%V-40°28＇ S/62°11＇W） Holocene in age （3-2 ky）, and modern beaches contain a significant amount of bioeroded ...The marine sediments of the area of Verde Peninsula - Jabali Island （39°28＇S/62°19%V-40°28＇ S/62°11＇W） Holocene in age （3-2 ky）, and modern beaches contain a significant amount of bioeroded mollusc shells. Fifteen sites were analyzed, in which 20.11% of the mollusc shells （2168 valves） presented bioerosion traces, in 54 species （30 bivalves and 24 gastropods）. Fourteen ichnogenera were reported： Entobia, Maeandropolydora, Iramena, Caulostrepsis, Pennatichnus, Pinaceocladichnus, Trypanites, and Gastrochaenolites （Domichnia）, Gnathichnus and Radulichnus （Pascichnia）, Finichnus and Centrichnus （Fixichnia）, Oichnus （Praedicnia） （macrobioerosion）, y Semidendrina （microbioerosion）, the latter is first reported in mollusc shells in Argentina. Eleven ichnospecies were identified Finichnus peristroma, Maeandropolydora sulcans, Gnathichnus pentax, Pinaceocladichnus onubensis, Caulostrepsis taeniola, Centrichnus eccentricus, Radulichnus inopinatus, Oichnus simplex, Oichnus paraboloides, Oichnus gradatus, and Gastrochaenolites torpedo （lithic remains）. The dominant ichnogenera in the Holocene deposits are Iramena, Entobia and Oichnus. The same ichnogenera are constant with different abundance in the modern beaches, and increasing representation of Pinaceocladichnus and Pennatichnus. The dominant ichnofacies in the Holocene deposits is Trypanites, revealing a benthonic marine community composed of cheilostome bryzoans, clionaid sponges, predator gastropods, regular echinoids, polychaete annelids, bivalves, thallophytas and fungi. Generally, the area was described as a sublittoral, low-energy, stable environment with high rate of oxygenation, and sandy bottoms, with rocky bottoms at Villalonga locality.展开更多
From the Global Historical Climate Network (GHCN-V3), monthly mean summer (DJF) temperature (1856-2012) and total precipitation (1861-2012) are analyzed in correlation with four climate modes and sunspot number to bet...From the Global Historical Climate Network (GHCN-V3), monthly mean summer (DJF) temperature (1856-2012) and total precipitation (1861-2012) are analyzed in correlation with four climate modes and sunspot number to better understand the role of teleconnections on Buenos Aires’ (Argentina) climate. A general increase in temperature and precipitation was observed. Temperature has increased by about 1.8°C and precipitation has increased by about 300 mm in the past century and a half. Indices of Arctic Oscillation (AO), Pacific North American (PNA), Antarctic Oscillation (AAO), and El Nino-Southern Oscillation (ENSO) are evaluated to study their effects on wheat and corn production and export. AO and PNA show strong relationships with precipitation and temperature received. AAO and ENSO show strong negative correlations with precipitation patterns and weak correlations with temperature. Sunspot Number shows a positive correlation with temperature. ENSO phases are strongly linked with the wheat and corn production and export;during El Nino Buenos Aires tends to experience extremely wet summer weather, causing soggy fields and extremely dry summer weather during La Nina causing drought. Both of these conditions result in reducing wheat and corn production and export.展开更多
Introduction: Mechanical or physical restraint is an exceptional therapeutic resource to immobilize a subject and thus guarantee the safety of the patient and/or third parties in the face of high-risk behaviors, but i...Introduction: Mechanical or physical restraint is an exceptional therapeutic resource to immobilize a subject and thus guarantee the safety of the patient and/or third parties in the face of high-risk behaviors, but it entails multiple crossings (bioethical, philosophical, medical, psychological, legal). Framed in the so-called “safety culture” developed by the WHO, based on the Protocol for its implementation of the CABA and attentive to its frequent use in CABA by different hospital services (medical clinic, geriatrics, intensive care and medical guards) we consider it necessary its study in terms of compliance with the risks it entails and its management. Objectives: Identify regulatory compliance with the GCABA Mechanical restraint (MR) Protocol from a patient safety perspective, as well as describe the clinical and medicolegal aspects, and propose the usefulness of a tool for its management and control. Methodology: Observational, descriptive, transversal and prospective work through the analysis of Clinical Records with indication of MR using a rubric-type form. 177 cases were analyzed between September-November 2023 from three hospitals of the Government of the City of Buenos Aires, statistical parameters were applied and graphs were made. Results: Only 12.99% complied with the Protocol. In the mental health specialized hospital compliance was almost 5 times greater than in the general one, and in the emergency services compliance was 12 times greater than in Inpatient services. We found that the start or end time of MR was not recorded and only 43% described the causes/justifications for the indication (mostly in Emergency and Specialized hospitals), with the MR average time being shorter in Emergency. Conclusions: Only 1.3 out of 10 patients reliably completed the Protocol and it was mostly in the mental health specialized hospital and the emergency services. The results show non-compliance behavior in the application and management of the risk that the use of mechanical restraints entails, being causes for criminal litigation. We consider that the checklists are useful to complete the Protocol and thus provide security to patients and professionals.展开更多
Background: The impact of urban air pollution and temperature changes over health is a growing concern for epidemiologists all over the world and particularly for developing countries where fewer studies have been per...Background: The impact of urban air pollution and temperature changes over health is a growing concern for epidemiologists all over the world and particularly for developing countries where fewer studies have been performed. Aim: The main goal of this paper is to analyze the short term effects of changes in temperature and atmospheric carbon monoxide on daily mortality in Buenos Aires, Argentina. Methods: We conducted a time series study focused on three age groups, gender, and cardiovascular and respiratory mortality, with lags up to four days and temporal variables as modifiers. Results: Temperature correlates positively with total mortality for summer months, with a RR = 1.0184 (95%, CI 1.0139, 1.0229) on the same day for each 1℃ increase. In winter this relationship reverses, as 1?C temperature increase exhibit a protective effect with a RR = 0.9894 (95%, CI 0.9864, 0.9924) at the 3 day lag. Carbon monoxide correlates always positively with mortality, with a RR = 1.0369 (95%, CI 1.0206, 1.0534) for each 1 ppm increase, on the previous day. Conclusions: Climate and pollution parameters measured in Buenos Aires City exhibit a correlation with health outcomes. The impacts of temperature and carbon monoxide vary with age and gender, being elderly the most susceptible subgroup. One day after an increase in CO of 1 ppm, about 4% extra deaths can be expected. The correlation found between increases in CO and mortality for greater lags may be ascribed to the role of CO as a chemical marker of urban air pollution, indicating the co-presence of other pollutants.展开更多
基金the funding support from the National Natural Science Foundation of China(Grant Nos.52350004 and 51925903).
文摘The freeze-thaw(FT)behavior of porous materials(PMs)involves the coupling of the thermo-hydromechanical(THM)processes and is significantly influenced by the microstructure.However,modeling FT in unsaturated PMs remains an open issue,and the influence of microstructure is not yet fully understood.To address these challenges,we propose a THM model for FT in PMs that considers microstructure and variable air content.In this work,a non-equilibrium thermodynamic approach is proposed to capture ice formation/melting,the microstructure is accounted for utilizing micromechanics,and the FT processes in air-entrained PMs are formulated within the proposed THM model.This model incorporates variable air void characteristics,e.g.air content,spacing factor,specific surface area,and supercooled water-filled regimes,and distinguishes the roles of air voids between freezing and thawing.The FT behaviors,including deformation,ice formation/melting,spacing factor,and pore water pressure evolutions,are focused.Comparisons with experimental results,confirm the capability of the present model.The results demonstrate the effects of variable air voids on the FT behavior of air-entrained PMs.The findings reveal that assuming fixed air void characteristics can lead to underestimation of pore pressure and deformation,particularly at low air content.Additionally,air voids act as cryo-pumps during freezing and when the cooling temperature stabilizes.During thawing,air voids supply gas to the melting sites(i.e.“gas escape”),preventing further significant deformation reduction.These results can provide novel insights for understanding the frost damage of PMs.
文摘With 1 185 pi eces of questionnaire, it is found that in China, people take fresh air, odor, e tc., as well as indoor air temperature, humidity, as the most important indoor a ir parameters. It is also found that there is a significant sensitivity differen ce in indoor environment between southerners and northerners in China. People fr om different regions have different demands for their working and living environ ment. Therefore, as a good design of air conditioning system, it is strongly rec ommended that the different demands of people from different regions should be t aken into consideration.
基金CONICETPICT 468(ANPCYT) for providing financial support to this research project
文摘The marine sediments of the area of Verde Peninsula - Jabali Island （39°28＇S/62°19%V-40°28＇ S/62°11＇W） Holocene in age （3-2 ky）, and modern beaches contain a significant amount of bioeroded mollusc shells. Fifteen sites were analyzed, in which 20.11% of the mollusc shells （2168 valves） presented bioerosion traces, in 54 species （30 bivalves and 24 gastropods）. Fourteen ichnogenera were reported： Entobia, Maeandropolydora, Iramena, Caulostrepsis, Pennatichnus, Pinaceocladichnus, Trypanites, and Gastrochaenolites （Domichnia）, Gnathichnus and Radulichnus （Pascichnia）, Finichnus and Centrichnus （Fixichnia）, Oichnus （Praedicnia） （macrobioerosion）, y Semidendrina （microbioerosion）, the latter is first reported in mollusc shells in Argentina. Eleven ichnospecies were identified Finichnus peristroma, Maeandropolydora sulcans, Gnathichnus pentax, Pinaceocladichnus onubensis, Caulostrepsis taeniola, Centrichnus eccentricus, Radulichnus inopinatus, Oichnus simplex, Oichnus paraboloides, Oichnus gradatus, and Gastrochaenolites torpedo （lithic remains）. The dominant ichnogenera in the Holocene deposits are Iramena, Entobia and Oichnus. The same ichnogenera are constant with different abundance in the modern beaches, and increasing representation of Pinaceocladichnus and Pennatichnus. The dominant ichnofacies in the Holocene deposits is Trypanites, revealing a benthonic marine community composed of cheilostome bryzoans, clionaid sponges, predator gastropods, regular echinoids, polychaete annelids, bivalves, thallophytas and fungi. Generally, the area was described as a sublittoral, low-energy, stable environment with high rate of oxygenation, and sandy bottoms, with rocky bottoms at Villalonga locality.
文摘From the Global Historical Climate Network (GHCN-V3), monthly mean summer (DJF) temperature (1856-2012) and total precipitation (1861-2012) are analyzed in correlation with four climate modes and sunspot number to better understand the role of teleconnections on Buenos Aires’ (Argentina) climate. A general increase in temperature and precipitation was observed. Temperature has increased by about 1.8°C and precipitation has increased by about 300 mm in the past century and a half. Indices of Arctic Oscillation (AO), Pacific North American (PNA), Antarctic Oscillation (AAO), and El Nino-Southern Oscillation (ENSO) are evaluated to study their effects on wheat and corn production and export. AO and PNA show strong relationships with precipitation and temperature received. AAO and ENSO show strong negative correlations with precipitation patterns and weak correlations with temperature. Sunspot Number shows a positive correlation with temperature. ENSO phases are strongly linked with the wheat and corn production and export;during El Nino Buenos Aires tends to experience extremely wet summer weather, causing soggy fields and extremely dry summer weather during La Nina causing drought. Both of these conditions result in reducing wheat and corn production and export.
文摘Introduction: Mechanical or physical restraint is an exceptional therapeutic resource to immobilize a subject and thus guarantee the safety of the patient and/or third parties in the face of high-risk behaviors, but it entails multiple crossings (bioethical, philosophical, medical, psychological, legal). Framed in the so-called “safety culture” developed by the WHO, based on the Protocol for its implementation of the CABA and attentive to its frequent use in CABA by different hospital services (medical clinic, geriatrics, intensive care and medical guards) we consider it necessary its study in terms of compliance with the risks it entails and its management. Objectives: Identify regulatory compliance with the GCABA Mechanical restraint (MR) Protocol from a patient safety perspective, as well as describe the clinical and medicolegal aspects, and propose the usefulness of a tool for its management and control. Methodology: Observational, descriptive, transversal and prospective work through the analysis of Clinical Records with indication of MR using a rubric-type form. 177 cases were analyzed between September-November 2023 from three hospitals of the Government of the City of Buenos Aires, statistical parameters were applied and graphs were made. Results: Only 12.99% complied with the Protocol. In the mental health specialized hospital compliance was almost 5 times greater than in the general one, and in the emergency services compliance was 12 times greater than in Inpatient services. We found that the start or end time of MR was not recorded and only 43% described the causes/justifications for the indication (mostly in Emergency and Specialized hospitals), with the MR average time being shorter in Emergency. Conclusions: Only 1.3 out of 10 patients reliably completed the Protocol and it was mostly in the mental health specialized hospital and the emergency services. The results show non-compliance behavior in the application and management of the risk that the use of mechanical restraints entails, being causes for criminal litigation. We consider that the checklists are useful to complete the Protocol and thus provide security to patients and professionals.
文摘Background: The impact of urban air pollution and temperature changes over health is a growing concern for epidemiologists all over the world and particularly for developing countries where fewer studies have been performed. Aim: The main goal of this paper is to analyze the short term effects of changes in temperature and atmospheric carbon monoxide on daily mortality in Buenos Aires, Argentina. Methods: We conducted a time series study focused on three age groups, gender, and cardiovascular and respiratory mortality, with lags up to four days and temporal variables as modifiers. Results: Temperature correlates positively with total mortality for summer months, with a RR = 1.0184 (95%, CI 1.0139, 1.0229) on the same day for each 1℃ increase. In winter this relationship reverses, as 1?C temperature increase exhibit a protective effect with a RR = 0.9894 (95%, CI 0.9864, 0.9924) at the 3 day lag. Carbon monoxide correlates always positively with mortality, with a RR = 1.0369 (95%, CI 1.0206, 1.0534) for each 1 ppm increase, on the previous day. Conclusions: Climate and pollution parameters measured in Buenos Aires City exhibit a correlation with health outcomes. The impacts of temperature and carbon monoxide vary with age and gender, being elderly the most susceptible subgroup. One day after an increase in CO of 1 ppm, about 4% extra deaths can be expected. The correlation found between increases in CO and mortality for greater lags may be ascribed to the role of CO as a chemical marker of urban air pollution, indicating the co-presence of other pollutants.
