What do We Know about Reaction Mechanism? The Electrospray Ionization Mass Spectrometry Approach

Santos, LS (reprint author), Univ Talca, Lab Asymmetr Synth, POB 747, Talca, Chile.Man's fascination with chemical reactions goes back to ancient times. With the introduction of spectroscopic techniques, the art of exploiting reactions became an intriguing science. It is, therefore, not surprising that one of the most flourishing and rewarding frontiers in modern Chemistry is the study of reaction mechanisms in chemical and biological processes. As man's imagination does not stop at the frontiers defined by nature, and with the ever increasing power of catalysis, the synthetic organic chemist is poised to make important contributions by inventing and developing new enabling technologies for the generation of new catalysts and methodologies. In this account is offered a new tool for accelerating the development through electrospray ionizationmass spectrometric (ESI-MS) monitoring in new reaction discovering

Efficient Water Use in Dairy Cattle Production: A Review

Background: Dairy cattle production has often been pointed out as a big source of wastewater; although these statements seem exaggerated, they can save a lot of water when a correct use of this resource is made. Objective: The objective of this review was to explore what technological improvements in drinking and feeding systems, water reuse systems, and irrigation systems have been made in the last ten years that allow a more efficient use of water and consequently a decrease in water use in dairy cattle production. Methods: The literature analysis for the review involved a keyword-based search, mainly for conference and/or journal articles. The scientific research databases, ScienceDirect and IEEE Xplore, as well as the scientific search engine Google Scholar, were employed to conduct this review. Results: Dairy farmers can reduce their water footprint by implementing practices that can include proper feeding of animals and monitoring of water consumption, adequate ventilation of facilities, as well as maintenance and repair of water, wastewater, and irrigation systems. Water from heat exchange systems to cool milk after milking can be reused to water and irrigate fields, and the farmers can also use technological equipment to increase the efficiency of irrigation. Conclusion: Proper management strategies are highly essential for sustaining the livestock production systems and meeting the food demands of a growing population with the available water resources, for which water-saving technologies and strategies are the need of the hour. The use of technological options has been a key driving force for the transition to smarter farming systems and for efficient water use in dairy farms.info:eu-repo/semantics/publishedVersio

Plantas medicinais da Península de Setúbal. Contribuição para o conhecimento da sua relevância Etnobotânica

A Península de Setúbal engloba ambientes muito distintos, na medida em que, por um lado, alberga cidades de grande/média e pequena dimensão, intimamente relacionadas com a capital, e por outro, áreas bem preservadas que integram parques naturais ou reservas/zonas protegidas. Assim sendo, os principais objectivos deste estudo prenderam-se com: 1) a caracterização dos remédios vegetais usados por populações distintas (as de áreas urbanas e as de áreas rurais); 2) a comparação e compreensão destas práticas (modo de aquisição e transmissão) e 3) a avaliação da influência da flora envolvente e da disponibilidade das plantas na sua persistência nestas populações. Os dados foram obtidos através de entrevistas semi-estruturadas a 121 pessoas, maioritariamente idosos, e permitiram recolher informações relativas ao nome vernáculo das plantas, à sua utilização terapêutica, ao seu modo de obtenção, aos procedimentos de colheita, à parte utilizada, ao seu modo de utilização, conservação e administração, a precauções/contraindicações do tratamento e ao modo de avaliação da sua eficácia, à fonte deste conhecimento e a outras utilizações das plantas. Foram referidos 186 usos medicinais distintos para os 253 taxa tentativamente catalogados, correspondendo a [Lavatera cretica L., Malva spp. (M. nicaeensis All.; M. sylvestris L.; M. tournefortiana L.); Pelargonium graveolens L' Her.] (“malvas”) o maior número de usos (31), enquanto que o taxon mais citado foi Aloysia triphylla (L'Hérit.) Britt. (“doce-lima”) (60 entrevistas). O grupo terapêutico com maior número de usos atribuído foi “Sistema digestivo” e o uso mais citado foi “Estômago” (45 taxa). Para averiguar de que modo as plantas eram caracterizadas pelos usos e os informantes pelas características identitárias (idade, sexo, local de nascimento, local de residência, escolaridade e actividade profissional) e plantas usadas (espécies, modo de aquisição, objectivo e regularidade do uso), recorreu-se à Análise das Correspondências seguida de Classificação Automática. Verificou-se que apesar de muitas das plantas terem várias aplicações terapêuticas, eram frequentemente utilizadas em afecções fisiologicamente relacionáveis. Constatou-se também que os informantes residentes em áreas mais urbanas apresentavam características distintas daqueles que residiam em áreas mais rurais, sendo que a sua área de residência tinha influência nas plantas que usavam. Para muitos dos parâmetros analisados a percentagem de esquecimento/desconhecimento foi importante, revelando que muitos dos informantes já não têm bem presentes os conhecimentos da medicina tradicional, o que confere urgência a uma recolha mais exaustiva destes conhecimentos, antes que desapareçam por completo

Temperature inversion symmetry in the Casimir effect with an antiperiodic boundary condition

We present explicitly another example of a temperature inversion symmetry in the Casimir effect for a nonsymmetric boundary condition. We also give an interpretation for our result.Comment: 4 page

Water requirements and footprint of a super intensive olive grove under Mediterranean climate

Abstract The water footprint of a product can be described as the volume of freshwater used to produce it, associated to a geographic and temporal resolution. For crops, the water footprint relates crop water requirements and yield. The components of water footprint, blue, green and grey water footprints, refer to the volumes of respectively, surface and groundwater, rainfall, and water required to assimilate pollution, used to produce the crop yield. The global standard for crop water footprint assessment relies on evapotranspiration models to estimate green and blue water evapotranspiration. This approach has been used in the present study to estimate the water footprint of a very high density drip irrigated olive grove and further compared with data obtained from evapotranspiration measurements or from its components: the eddy covariance method to quantify latent heat flux, a heat dissipation sap flow technique to determine transpiration and microlysimeters to evaluate soil evaporation. The eddy covariance technique was used for short periods in 2011 and 2012, while sap flow measurements were performed continuously, hence allowing the extension of the data series. Measurements of evapotranspiration with the eddy covariance method provided an average close to 3.4 mm d-1 (2011) and 2.5 mm d-1 (2012). The ratio of evapotranspiration to reference evapotranspiration approached 0.6 and 0.4 for the respective periods. The water footprint of the olive crop under study, calculated with field data, was higher than the water footprint simulated using the global standard assessment and was lower than that reported in literature for olives. Lower values are probably related to differences in cultural practices, e.g., the density of plantation, harvesting techniques and irrigation management. The irrigated high-density olive grove under study had a high yield, which compensates for high water consumption, thus leading to a water footprint lower than the ones of rainfed or less dense groves. Other differences may relate to the procedures used to determine evapotranspiration

Production and Characterization of Energy Materials with Adsorbent Properties by Hydrothermal Processing of Corn Stover with Subcritical H2O

This work aims to investigate the effect of temperature on the process performance of hydrothermal processing (HTC) of corn Stover with subcritical H2O and on the morphology of solid products. The experiments were carried out at 200, 225 and 250 ºC, reaction time of 240 minutes, heating rate of 2.0 ºC/min, and biomass to water ratio of 1:10, using a pilot scale stirred tank reactor (STR) of 5 gallon, operating in batch mode. The process performance analyzed by computing the yields of solid and liquid reaction products (RLP). The aqueous phase (H2O + RLP) was physicochemical analyzed for pH and total carboxylic acids, expressed as total acetic acid content. The chemical compositions of carboxylic acids, furfural, and hydroxymethylfurfural (HMF) in the aqueous phase determined by GC-MS and HPLC. The results showed solid yields ranging from 57.39 to 35.82% (wt.), and liquid reaction products (RLP) yields ranging from 39.53 to 54.59% (wt.). The solid phase products were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The chemically activated (2.0 M NaOH) solid phase energy material obtained by HTC at 250 °C, applied as adsorbent to investigate the capacity and/or efficiency to adsorb acetic acid from 1.0 to 4.0 g/L model solutions at 25 °C. The solid phase yield decreases along with the temperature, showing an inflection region between 200 and 225 °C, whereas a drastic change takes place, while that of liquid phase increases, showing also a drastic change between 200 and 225 °C. The total acetic acid content of aqueous phase varied from 4064 to 5387 mg/L, while the pH from 3.77 to 3.91. The GC analysis identified the presence of volatile carboxylic acids, particularly acetic acid, in concentrations between 4020 and 5040 mg/L. HPLC identified the presence of furfural and hydroxymethylfurfural, whose concentrations decrease exponentially and linearly along with the temperature between 686.7 and 0.0, and 443.9 and 0.0 mg/L, respectively, being both compounds not detectable at 250 °C. The elemental/ultimate analysis of solid products shows that carbon content increases, while the oxygen and hydrogen contents decrease, along with the temperature. The H/C and O/C ratios decrease linearly as process temperature increases, and the high heating value (HHV) of solid reaction products, an energy densified material, changes sharply between 200 and 225 °C, showing an increase with temperature. The SEM, EDX, and XDR indicates a change on the morphology and mineralogical phases present in solid reaction products with temperature, particularly at 250 °C. The activated solid phase has proven to be very selective to adsorb acetic acid, showing that recovery of acetic acid from hydrothermal carbonization/liquefaction aqueous solutions is feasible by using a multistage-stage adsorption process in series

tri-n-butyltin hydride-mediated radical reaction of a 2-iodobenzamide: Formation of an unexpected carbon-tin bond

Leonardo S. Santos. Instituto de Química de Recursos Naturales, Universidad de Talca, P.O. Box 747, Talca - Chile.The tri-n-butyltin hydride-mediated reaction of methyl 2,3-di-O-benzyl-4-O-trans-cinnamyl -6-deoxy-6-(2-iodobenzoylamino)-a-D-galactopyranoside afforded an unexpected aryltributyltin compound. The structure of this new tetraorganotin(IV) product has been elucidated by 1H, 13C NMR spectroscopy, COSY and HMQC experiments and electrospray ionization mass spectrometry (ESI-MS). The formation of this new compound via a radical coupling reaction and a radical addition-elimination process is discusse

Impact of the urbanisation process in the availability of ecosystem services in a tropical ecotone area

Urbanisation has been a main cause of land use land cover (LULC) change worldwide, often with irreparable consequences to the provision of ecosystem services. Despite an increase in quantitative assessments of ecosystem services value (ESV) related to LULC changes, data are scarce for ecotones, such as the agreste in northeast Brazil (a transitional area between the Atlantic Forest and the Caatinga biomes). The benefit transfer method was used to quantify changes in ESV between 1989, 2007 and 2014 due to urbanisation in the microwatershed Riacho das Piabas (3,660 ha) in the agreste of Paraíba. Remote sensing techniques and geographic information system were used to quantify LULC changes. Loss of arboreal vegetation (covering 46% of the study area in 1989 and 5% in 2014) was the key factor driving the 73.2% decline in the total ESV (from US$13.7 million to US$ 3.7 million in 2017 values). LULC changes resulted in losses of 89% in the estimated value of eight ecosystem services, including climate regulation, water flow regulation, moderation of disturbance, nutrient cycling and biological control, which are critical locally when considering the regional trend towards aridification and the existing pressures on water resources. Ecosystem functions loss and climate change impacts may lead to a shift in ecotone boundaries favouring the semiarid Caatinga vegetation. These results urge the implementation of ecosystem-based spatial planning, focusing on urban green infrastructure and restoration of natural habitats and their connectivity, to prevent further ecosystem services losses. Local estimates of ESV required to inform the suggested policy actions are identified

Indexes Of Spatio-temporal Change To Reconstruct The Historical Evolution Of A Coastal Region - Case Study: São Sebastião Island - Sp

The coastal regions of Brazil have lost most of their distinct characteristics due to an intense, diverse, and long history of land use. The current scenario is the result of successive changes which have taken place since the colonization of Brazil. These changes should be taken into account in environmental planning since the decisions about the future depend on the understanding of past changes. In this regard, the aim of this study was to identify and quantify the spatio-temporal changes in land use in a coastal region, using principles of landscape ecology and scenario construction. The case study was the São Sebastião Island, divided into 61 watersheds, off the northern coast of São Paulo State (Brazil). The study involved the development and application of a methodology to interpret the historical dynamics of the island. The driving forces were identified and indexes of change were calculated to define the phases of occupation of the island. Five phases of occupation of the coastal landscape were mapped: preservation, conservation, regeneration, exploitation and urbanization. These phases represent a pattern of internal heterogeneity, sometimes positive (environmental conservation), and sometimes negative (environmental degradation).58SPEC. ISSUE 33747França, A.A., (1954) Ilha De São Sebastião: Estudo De Geografia Humana, , São Paulo: USPFujihara, M., Kikuchi, T., Changes in the landscape structure of the Nagara Watershed, central Japan (2005) Landscape and Urban Planning, 70, pp. 271-281Gibson, C.C., Ostrom, E., Anh, T.H., The concept of scale and the human dimension of global change: A survey (2000) Ecological Economics, 32, pp. 217-239Pedreira, B.C.C.G., Santos, R.F., Sensores emotos, escalas geográficas e análises espaciais orientados a planejamentos ambientais em áreas florestais (2003) Revista Do Instituto Florestal, São Paulo, 15 (2), pp. 81-96de Ilhabela, P.M., (2005) Plano Gestor De Turismo - Estância Balneária IlhabelaSantos, M.A., Santos, R.F., (2008) Construção De Cenários Por Análises Temporais E Métricas Espaciais, , Revista do Instituto FlorestalSantos, R.F., (2004) Planejamento Ambiental - Teoria E Prática, , São Paulo: Oficina de Texto(2008) Relatório Estadual De Acompanhamento Dos Objetivos De Desenvolvimento Do Milênio - 2008, , SEADE - FUNDAÇÃO SISTEMA ESTADUAL DE ANÁLISE DE DADOS. São Paulo: Imprensa Oficial do Estado de São PauloStefanov, W.L., Ramsey, M.S., Christensen, P.R., Monitoring urban land cover change: An expert system approach to land cover classification of semiarid to arid urban centers (2001) Remote Sensing of Environment, 77, pp. 173-185Turner, M.G., Gardner, R.H., Oneill, R.V., (2001) Landscape Ecology in Theory and Practice: Pattern and Process, p. 401. , New York: Springer-VerlagWeng, Y.C., Spatiotemporal changes of landscape pattern in response to urbanization (2007) Landscape and Urban Planning, 81, pp. 341-353Wilson, J.S., Clay, M., Martin, E., Stuckey, D., Vedder-Risch, K., Evaluating environmental influences of zoning in urban ecosystems with remote sensing (2003) Remote Sensing of Environment, 86, pp. 303-321Wu, J., Hobbs, R.J., (2007) Key Topics in Landscape Ecology, , Cambridge University Press. United Kingdo