2,207 research outputs found
Processes of MISS-formation in a modern siliciclastic tidal flat, Patagonia (Argentina)
The study focus on the description of several MISS as erosional pockets and remnants, flipped-over edges, and large microbial deformation structures as roll-ups, folds and gas domes, in the context of sediment composition, hydraulics, and geomorphology. The aim of the paper is to recognize the mechanisms of formation of MISS by analyses on hydrodynamics under the influence of the geomorphology. The study was conducted in an elongated inactive tidal channel colonized by microbial mats (2.5 × 0.3 km) in a progradation environment. To continuously record the water-level fluctuations, a HOBO water level logger was placed 40 cm below the flat surface for two years. The sea water enters several times a year, during storms, where the flood currents were characterized by faster velocity than ebb currents, reaching a water depth up to 0.70 m over the tidal flat. That coastal process creates MISS over the tidal flat. The most conspicuous microbial structures are the huge deformation roll-ups several m-scale, associated to elongated rip-off mats, folds and flipped over mats. The process of fluidization was postulated to explain the sand-infilling of gas domes and folds we observed. This process would result from the wave action on the water column that produces a temporal fluid behavior of the underlying sand.Fil: Maisano, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Cuadrado, Diana Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Gomez, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Universidad Tecnológica Nacional. Facultad Regional Bahía Blanca; Argentin
Single crystal growth and study of the magnetic properties of the mixed spin-dimer system BaSrCrO
The compounds SrCrO and BaCrO are
insulating dimerized antiferromagnets with Cr magnetic ions. These
spin- ions form hexagonal bilayers with a strong intradimer
antiferromagnetic interaction, that leads to a singlet ground state and gapped
triplet states. We report on the effect on the magnetic properties of
SrCrO by introducing chemical disorder upon replacing Sr by
Ba. Two single crystals of BaSrCrO with
(3.33\% of ) and (6.66\%) were grown in a four-mirror type
optical floating-zone furnace. The magnetic properties on these compounds were
studied by magnetization measurements. Inelastic neutron scattering
measurements on BaSrCrO were performed in order to
determine the interaction constants and the spin gap for . The
intradimer interaction constant is found to be =5.332(2) meV, about 4\%
smaller than that of pure SrCrO, while the interdimer
exchange interaction is smaller by 6.9\%. These results indicate a
noticeable change in the magnetic properties by a random substitution effect
THE CONDITION OF WASTE MANAGEMENT IN ROMANIA
The present article approaches a very important and actual theme and that is the problem of generating waste in Romania which, on one hand, affects the environment and human health, and on the other hand it reflects the inefficient way of using the natural resources in society. Probably the majority of us have thought or hoped that the natural resources are inexhaustible, but we can see today that the unwise exploitation of these resources is threatening our future. Waste management is a difficult and complex problem in Romania which is far from being solved according to the environment rules of the European Union. The worsening of the waste problem, especially of the domestic waste is generated by the significant increase of its quantity, as well as by the inappropriate way of solving different stages of waste processing.environmental protection; waste; waste management; reuse, reduce and recycle waste
Oferta de biomasa y regulación de temperatura del arbolado urbano en Puerto Carreño, Vichada - Colombia
Los bosques urbanos se consideran un elemento clave en la estructura ecológica de las ciudades, contribuyendo a la provisión de servicios ecosistémicos como el secuestro de carbono y la regulación climática. Sin embargo, pocos estudios han investigado estos servicios de regulación en ciudades pequeñas del Neotrópico. El objetivo de este estudio fue estimar el suministro de biomasa y el carbono secuestrado por el arbolado urbano, así como evaluar la capacidad de regulación térmica de los árboles durante la temporada más calurosa de 2021 (de diciembre de 2020 a mayo de 2021) en Puerto Carreño - Colombia. Se implementó un muestreo aleatorio a través de 200 parcelas circulares para estimar la biomasa y el almacenamiento de carbono de los árboles. Además, utilizamos 16 sensores iButton digitales ubicados en sitios por pares (sin sombra y con sombra de árboles) en ocho coberturas de suelo dentro de la ciudad para medir la temperatura y la humedad por hora durante seis meses. Encontramos que los bosques urbanos en Puerto Carreño tienen una diversidad de árboles relativamente alta y estructuras verticales complejas, mayores que las de ciudades más pobladas de la región, y un alto almacenamiento de carbono (en un rango entre 37 - 51 tC/ha). La regulación térmica de los bosques urbanos aumenta exponencialmente con la temperatura ambiente, es decir, 7,5 °C a 44 °C, mientras que 2 °C a 34,9 °C. Específicamente, durante los extremos de calor más altos, los bosques urbanos neotropicales maximizan los efectos de enfriamiento. La humedad relativa es generalmente mayor en las áreas sombreadas que en las áreas sin sombra, lo que es aún más pronunciado durante los períodos críticos de calor. Bajo un contexto global, Puerto Carreño tiene un alto riesgo de desarrollar una combinación mortal de condiciones climáticas de temperatura y humedad. Altos índices de no confort térmico son mitigados considerablemente por los bosques urbanos por un factor de 10 durante las horas más calurosas (9 a.m. a 4:00 p.m.). Las encuestas aplicadas confirmaron que las personas perciben los efectos de bienestar de los árboles y sus servicios de regulación del clima: la sombra de los árboles y la provisión de frutas fueron los beneficios de los servicios ecosistémicos más identificados por los residentes. Nuestro estudio muestra que los bosques urbanos tropicales son una medida clave de mitigación a nivel local y global (sumideros de carbono) y adaptación (reducción del calor extremo) para combatir el cambio climático.Urban forests are considered a key element in the ecological structure of cities, contributing to the provision of ecosystem services such as carbon sequestration and climate regulation. However, few studies have investigated these regulating services in small Neotropical cities. The aim of this study was to estimate the biomass supply and carbon sequestered by urban trees, as well as to evaluate the capacity of trees in thermal regulation during the hottest season in 2021 (from December 2020 to May 2021) in Puerto Carreño - Colombia. Accordingly, we implemented random sampling through 200 circular plots to estimate the biomass and carbon storage of trees. Moreover, we used 16 digital iButton sensors located in paired sites (unshaded and tree-shaded) in eight ground covers in the city to measure hourly temperature and humidity for six months. We find that urban forests in Puerto Carreño have relatively high tree diversity and complex vertical structures, greater than that of more populated cities in the region, and high carbon storage (in a range between 37 - 51 tC/ha). Thermal regulation by urban forests increases exponentially with the ambient temperature i.e. 7,5°C at 44 °C but 2°C at 34,9°C. Specifically, during higher daily heat extremes, cooling effects are maximized by neotropical urban forests. Relative humidity is generally greater in shaded areas versus unshaded areas, which is even more pronounced during critical hot periods. Under a global context, Puerto Carreño has a high risk to develop a deadly combination of climatic conditions for temperature and humidity. Very high discomfort indexes are considerably mitigated by urban forests by a factor of 10 during the hottest hours (9 a.m. to 4:00 p.m.). On site surveys confirmed that people perceive the well-being effects of trees and their climate regulating services: tree shade and fruit provision were the key ecosystem service benefits mostly identified by residents. Our study shows that tropical urban forests are key local and global mitigation (carbon stocks) and adaptation (extreme heat reduction) measures to fight climate change.Asociación Colombo-Francesa de Investigadores - COLIFR
The impact of rainwater harvesting and fertilizer micro-dosing on farm and household sustainability in rural Tanzania
Food insecurity and poverty are of major concern for farmers in Tanzania, and the technologies rainwater harvesting coupled with fertilizer micro-dosing promise to aid in easing these burdens, particularly in a water-limited context. In this study, I performed an ex-post assessment of the impact of these two innovations in the sustainability of households and farms, in two contrasting regions of Tanzania semi-arid Dodoma and semi-humid Morogoro, to see if they would be relevant to promote in the country. The method used accounts for households’ and farms’ characteristics, estimates sustainability indicators, and uses a difference-in-differences propensity score matching (PSM) estimator. The results indicate contrary to expectations, that the households in the semi-arid region of Dodoma are not benefiting from the adoption of the innovations, neither in food security nor in economic sustainability and even exacerbated the frequency of water conflicts by 7%. On the opposite, in the semi-humid region of Morogoro, these two innovations enhanced households’ environmental sustainability and food security by increasing these indices by 3% and 10% respectively. Using aggregated indicators to assess the impact of rainwater harvesting and fertilizer micro-dosing on economic, social and environmental aspects, was relevant to show that these technologies have limited benefits on the sustainability of farmers’ households in Tanzania, thus need to be complemented by policies that promote households’ characteristics associated with better food security and economic results, such as training for higher levels of education, greater land security, and promoting the cultivation of cash-crops
The flexible periodic vehicle routing problem: modeling alternatives and solution techniques
In this thesis the Flexible Periodic Vehicle Routing Problem is introduced and studied. In this problem a carrier must establish a distribution plan to serve a given set of customers over a planning horizon using a fleet of homogeneous capacitated vehicles. The total demand of each customer is known for the time horizon and it can be satisfied by visiting the customer in several time periods. There is, however, a limit on the maximum quantity that can be delivered at each visit. The aim is to minimize the total routing cost. This problem can be seen as a generalization of the Periodic Vehicle Routing Problem which, instead, has fixed service schedules and fixed delivered quantities per visit. On the other hand, the Flexible Periodic Routing Problem shares some characteristics with the Inventory Routing Problem in which inventory levels are considered at each time period, the delivery of product is a decision of the problem and, typically, an inventory cost is involved in the objective function. The relation among these periodic routing problems is discussed and a worst-case analysis, which shows the advantages of the studied problem with respect to the problems with periodicity mentioned above, is presented. Furthermore, alternative mixed-integer programming formulations are described and computationally tested.
Given the difficulty to optimally solve the studied problem for small size instances, a matheuristic is developed, which is able to solve large size instances efficiently. Extensive computational experiments illustrate the characteristics of the solutions of the problem and show that, also in practice, allowing flexible policies may produce substantial savings in the routing costs in comparison with both the Periodic Vehicle Routing Problem and the Inventory Routing Problem.: En esta tesis se presenta y estudia el Problema de Ruteo de Vehículos Periódico Flexible. En este problema, un transportista debe establecer un plan de distribución para atender a un conjunto determinado de clientes durante un horizonte de planificación utilizando una flota de vehículos con capacidad homogénea. La demanda total de cada cliente es conocida por el horizonte temporal y se puede satisfacer visitando al cliente en varios períodos de tiempo. Sin embargo, hay un límite en la cantidad máxima que se puede entregar en cada visita. El objetivo es minimizar el costo total de ruteo. Este problema puede verse como una generalización del Problema clásico de Ruteo de Vehículos Periódico que, en cambio, tiene programas de servicio fijos y cantidades de entrega fijas por visita. Por otro lado, el Problema de Ruteo de Vehículos Periódico Flexible comparte algunas características con el Problema de Ruteo de Inventarios en el cual los niveles de inventario se consideran en cada período de tiempo, la entrega del producto es una variable de decisión y, típicamente, un costo de inventario está involucrado en la función objetivo. Se discute la relación entre estos problemas periódicos de rutas y se presenta un análisis del peor de los casos, que muestra las ventajas del problema estudiado con respecto a los problemas periódicos mencionados anteriormente. Además, las formulaciones alternativas de programación entera mixta se describen y se prueban computacionalmente. Dada la dificultad de resolver a optimalidad el problema estudiado para instancias de tamaño pequeño , se desarrolla una matheurística que puede resolver instancias de gran tamaño de manera eficiente. Una extensa experiencia computacional ilustra las características de las soluciones del problema y muestra que, también en la práctica, permitir políticas flexibles puede producir ahorros sustanciales en los costos de ruteo en comparación con el Problema de Ruteo de Vehículos Periódico y el Problema de Rutas de Inventario.Postprint (published version
Landscape and Environment: Social Acceptance of Wind Energy in Apulia and Basilicata Regions
The present paper is centred on the issue of social (or public) acceptance of renewable energy. Due to the climate change at global level, governments are showing an increasing interest in the adoption of renewable energy policies. Nonetheless, social acceptance to renewable energy still represents an obstacle to these policies. This is particularly true for wind energy. Generally, a wind farm project could alter the aesthetic view of a territory and rise an active opposition to its development. Furthermore, the lack of knowledge and the lack of trust towards the technology and the institutions could undermine a wind energy project. The paper critically reviews the public acceptance of renewable energy with a particular emphasis on wind energy, and examines the main factors determining the success or the failure of a wind energy project and their importance to support the decision making process. The issue of social acceptance is studied through a survey carried out in the regions of Apulia and Basilicata, in the South of Italy. The rationale behind the choice of these regions is that they are represent, particularly in the case of Apulia, a large portion of the wind energy installation capacity in Italy. Additionally, an ANOVA analysis is performed to assess whether similarities exist across these regions. Finally, the social acceptance of wind energy is discussed in the light of the particular territorial context of the two regions
THE CONDITION OF WASTE MANAGEMENT IN ROMANIA
The present article approaches a very important and actual theme andthat is the problem of generating waste in Romania which, on one hand,affects the environment and human health, and on the other hand itreflects the inefficient way of using the natural resources in society.Probably the majority of us have thought or hoped that the naturalresources are inexhaustible, but we can see today that the unwiseexploitation of these resources is threatening our future.Waste management is a difficult and complex problem in Romania whichis far from being solved according to the environment rules of theEuropean Union. The worsening of the waste problem, especially of thedomestic waste is generated by the significant increase of its quantity, aswell as by the inappropriate way of solving different stages of wasteprocessing
Nivelul de informare şi atitudinea față de raportarea reacțiilor adverse la medicamente
Background. The action of drugs is like a balance, on the one side being placed the benefits and on the
other the risks. Each drug has a wide range of adverse reactions, so their detection, analysis and reporting
have a major importance in medical practice. Objective of the study. The aim of the study is to
determine the level of knowledge and attitude of physicians towards adverse drug reaction reporting and
to identify impediments which lead to a low reporting rate. Material and Methods. The study was
based on a questionnaire consisting of 32 questions. The attitude was evaluated using Inman's "seven
deadly sins".For each questionnaire was calculated the score, each favourable and unfavourable
response receiving 1 and 0 points, respectively. Total score of 70 % and more for each domain was
qualified as "satisfactory" and less than 70 % as "unsatisfactory". Results. Eighty-three participants
completed the questionnaire. Regarding the level of knowledge, 50,6 % have a unsatisfactory level, 65,1
% don't know how the information presented in reports is used. Regarding the attitude, 72,4 % have a
unsatisfactory attitude toward ADR reporting, 78,3 % showed complacency, 89,2 % insecurity and 73,5
% lethargy. 95.2% consider reporting a professional obligation, but 44.6% consider that the involvement
of specialists should be remunerated. Statistical differences were determined between the scores
accumulated by the age groups (p= 0,001), while no differences were found between the groups of
specialists. Conclusion. The study showed unsatisfactory results for the level of information and
attitude of physicians regarding adverse drug reaction reporting. The age or practical experience of the
physicians could be a decisive factor for the level of knowledge.
Introducere. Acțiunea medicamentelor este ca o balanță, pe unul din talere plasându-se beneficiile, iar
pe celălalt riscurile. Fiecare medicament posedă o gamă vastă de efecte adverse, astfel, detectarea,
analiza și raportarea acestora au o importanță majoră în practica medicală. Scopul lucrării. Scopul
studiului este de a determina nivelul de informare și atitudinea referitor la raportarea reacțiilor adverse
la medicamente în rândurile medicilor, precum și de a identifica impedimentele care conduc la scăderea
ratei raportării. Material și Metode. Studiul s-a bazat pe un chestionar compus din 32 de întrebări.
Atitudinea a fost evaluată folosind cele „șapte păcate mortale” ale lui Inman. Pentru fiecare chestionar
a fost calculat scorul, fiecare răspuns afirmativ și negativ primind 1 și 0 puncte, respectiv. Scorul total
de 70 % și mai mult pentru fiecare domeniu a fost calificat ca „satisfăcător”, iar mai puțin de 70 % ca
„nesatisfăcător”. Rezultate. Chestionarul a fost completat de 83 de participanți. Referitor la nivelul de
informare, 50,6 % au prezentat un nivel nesatisfăcător, 65,1 % nu cunosc cum este utilizată informația
din fișele de raportare. În privința atitudinii, 72,4 % au prezentat o atitudine nesatisfăcătoare față de
raportarea RAM, 78,3 % demonstrând automulțumire, 89,2 % nesiguranță și 73,5 % letargie. 95,2 %
dintre respondenți consideră raportarea o obligație profesională, dar 44,6 % sunt de părere că implicarea
specialiștilor ar trebui să fie remunerată. Între scorurile acumulate de grupele de vârstă au fost
determinate diferențe statistice (p= 0,001), pe când între grupele de specialiști acestea
lipsesc. Concluzii. Studiul a arătat rezultate nesatisfăcătoare pentru nivelul de informare și atitudinea
medicilor referitor la raportarea reacțiilor adverse la medicamente. Vârsta sau experiența practică a
medicilor ar putea fi un factor determinant al nivelului de informare
Tipos naturais, tipos normativos e comportamento humano
The main thesis of this paper is that a large part of human behavior cannot be understood in terms of natural kinds but by appealing to normative kinds. In the first section we explain the distinction between natural kinds and normative kinds. In the second section we focus on the notion of “human behavior”, proposing a distinction between type A and type B behaviors and pointing out that psychology deals with type B behaviors, which are also included as diagnostic criteria for mental disorders. In the third section we analyze the strategies used in biomedical research to find specific etiologies (“essences”) in order to explain such disorders. We argue that their results are inconsistent and that the lack of biomarkers that are clinically useful to refine the diagnoses is due to the fact that, unlike certain neuropathologies, there are no physiological essences behind such disorders. On the other hand, we argue that, as we are dealing with type B behaviors, we must interpret mental disorders as normative kinds.Keywords: human behavior, natural kinds, normative kinds. A tese principal deste artigo é que uma grande parte do comportamento humano não pode ser entendida em termos de tipos naturais, mas deve recorrer a tipos normativos. Na primeira seção, explicamos a distinção entre tipos naturais e tipos normativos. Na segunda seção, ressaltamos a noção de “comportamento humano”, propondo uma distinção entre comportamentos do tipo A e tipo B e salientando que a psicologia lida com comportamentos do tipo B, que também são incluídos como critérios de diagnóstico para transtornos mentais. Na terceira seção, analisamos as estratégias utilizadas na pesquisa biomédica, a fim de encontrar etiologias específicas (“essências”) para explicar esses transtornos. Argumentamos que seus resultados são inconsistentes e que a falta de biomarcadores clinicamente úteis para refinar os diagnósticos se deve ao fato de que, diferentemente de certas neuropatologias, não existem essências fisiológicas por trás desses transtornos. Por outro lado, argumentamos que, ao lidarmos com comportamentos do tipo B, devemos interpretar os transtornos mentais como tipos normativos.Palavras-chave: comportamento humano, tipos naturais, tipos normativos
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