Growth and production of irrigated vitória pineapple grown in semi-arid conditions

This study aimed to evaluate the growth characteristics of irrigated Vitória pineapple plants grown in semi-arid conditions and determine its developmental stages based on those characteristics. It was used a randomized block design with four replicates. The experimental treatments were: plant harvest at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The following variables were determined: plant height, stem diameter, D-leaf length, D-leaf fresh and dry mass, biomass production of plants and plant parts (organs), and vegetative biomass. Five phenological stages are proposed based on vegetative biomass production: < 20% biomass production (V1); 21-40% (V2); 41-60% (V3); 61-80% (V4); and > 80% (V5). The maximum growth rate for plant height, D-leaf length, and stem diameter was observed at the end of the phenological stage V1 (390-411 DAP), and at the end of stage V5 these plant traits had average values of 106, 82, and 7 cm, respectively. The maximum biomass accumulation rates were observed at stages V4 and V5, resulting in a final fruit yield and total fresh biomass of 72 t ha-1 and 326 t ha-1, respectively. Finally, we estimated that 80% of the accumulated biomass may remain in the field after fruit and slip harvest, and could be incorporated as plant residue into the soil.

CITRICULTURE ECONOMIC AND FINANCIAL EVALUATION UNDER CONDITIONS OF UNCERTAINTY

ABSTRACT The citriculture consists in several environmental risks, as weather changes and pests, and also consists in considerable financial risk, mainly due to the period ofreturn on the initial investment. This study was motivated by the need to assess the risks of a business activity such as citriculture. Our objective was to build a stochastic simulation model to achieve the economic and financial analysis of an orange producer in the Midwest region of the state of Sao Paulo, under conditions of uncertainty. The parameters used were the Net Present Value (NPV), the Modified Internal Rate of Return(MIRR), and the Discounted Payback. To evaluate the risk conditions we built a probabilistic model of pseudorandom numbers generated with Monte Carlo method. The results showed that the activity analyzed provides a risk of 42.8% to reach a NPV negative; however, the yield assessed by MIRR was 7.7%, higher than the yield from the reapplication of the positive cash flows. The financial investment pays itself after the fourteenth year of activity.

Monte Carlo thermodynamic and structural properties of the TIP4P water model: dependence on the computational conditions

Classical Monte Carlo simulations were carried out on the NPT ensemble at 25°C and 1 atm, aiming to investigate the ability of the TIP4P water model [Jorgensen, Chandrasekhar, Madura, Impey and Klein; J. Chem. Phys., 79 (1983) 926] to reproduce the newest structural picture of liquid water. The results were compared with recent neutron diffraction data [Soper; Bruni and Ricci; J. Chem. Phys., 106 (1997) 247]. The influence of the computational conditions on the thermodynamic and structural results obtained with this model was also analyzed. The findings were compared with the original ones from Jorgensen et al [above-cited reference plus Mol. Phys., 56 (1985) 1381]. It is notice that the thermodynamic results are dependent on the boundary conditions used, whereas the usual radial distribution functions g(O/O(r)) and g(O/H(r)) do not depend on them.

Labile copper and zinc fractions under different salinity conditions in a shipyard area in the patos lagoon estuary, south of Brazil

Copper and zinc are common elements in paint residues and can be toxic to estuarine organisms. This study aims to determine the labile dissolved and labile particulate fractions (LPFs) of copper and zinc in the estuarine waters of a shipyard in southern Brazil under different salinity levels and in different seasons. The labile dissolved fraction was determined using the diffusive gradient in thin-film (DGT) technique. The variations in DGT-Cu (0.22-1.05 µg L-1), DGT-Zn (0.54-18.39 µg L-1), LPF-Cu (1.22-3.77 µg g-1), and LPF-Zn (4.29-19.12 µg g-1) concentration were related to changes in their physico-chemical parameters and as a result of boat maintenance activities.

Optimization of chromatographic conditions and comparison of extraction efficiencies of four different methods for determination and quantification of pesticide content in bovine milk by UFLC-MS/MS

This paper describes the optimization of a multiresidue chromatographic analysis for the identification and quantification of 20 pesticides in bovine milk, including three carbamates, a carbamate oxime, six organophosphates, two strobilurins, a pyrethroid, an oxazolidinedione, an aryloxyphenoxypropionate acid/ester, a neonicotinoid, a dicarboximide, and three triazoles. The influences of different chromatographic columns and gradients were evaluated. Furthermore, four different extraction methods were evaluated; each utilized both different solvents, including ethyl acetate, methanol, and acetonitrile, and different workup steps. The best results were obtained by a modified QuEChERS method that lacked a workup step, and that included freezing the sample for 2 hours at -20 ºC. The results were satisfactory, yielding coefficients of variation of less than 20%, with the exception of the 50 µg L-1 sample of famoxadone, and recoveries between 70 and 120%, with the exception of acephate and bifenthrin; however, both analytes exhibited coefficients of variation of less than 20%.

PYROLIGNEOUS LIQUOR PRODUCED FROM ACACIA MEARNSII DE WILD WOOD UNDER CONTROLLED CONDITIONS AS A RENEWABLE SOURCE OF CHEMICALS

Acacia mearnsii de Wild (black wattle) is one of the most important trees planted in Southern Brazil for tannin extraction and charcoal production. The pyrolysis of the black wattle wood used for obtaining charcoal is performed in brick ovens, with the gas fraction being sent directly into the environment. The present study examines the condensable compounds present in the liquor produced from black wattle wood at different thermal degradation conditions, using gas chromatography coupled with mass spectrometry (GC/MS). Branches of black wattle were thermally degraded at controlled ambient and temperature conditions. Overall, a higher variety of compounds were obtained under atmospheric air pressure than under synthetic air pressure. Most of the tentatively identified compounds, such as carboxylic acids, phenols, aldehydes, and low molecular mass lignin fragments, such as guayacol, syringol, and eugenol, were products of lignin thermoconversion. Substituted aromatic compounds, such as vanillin, ethyl vanillin, and 2-methoxy-4-propeny-phenol, were also identified. At temperatures above 200 ºC, furan, 2-acetylfuran, methyl-2-furoate, and furfural, amongst others, were identified as polysaccharide derivatives from cellulose and hemicellulose depolymerization. This study evidences the need for adequate management of the condensable by-products of charcoal production, both for economic reasons and for controlling their potential environmental impact.

Temporal progress of southern rust in maize under different environmental conditions

The progress of the severity of southern rust in maize (Zea mays) caused by Puccinia polysora was quantified in staggered plantings in different geographical areas in Brazil, from October to May, over two years (1995-1996 and 1996-1997). The logistic model, fitted to the data, better described the disease progress curves than the Gompertz model. Four components of the disease progress curves (maximum disease severity; area under the disease progress curve, AUDPC; area under the disease progress curve around the inflection point, AUDPCi; and epidemic rate) were used to compare the epidemics in different areas and at different times of planting. The AUDPC, AUDPCi, and the epidemic rate were analyzed in relation to the weather (temperature, relative humidity, hours of relative humidity >90%, and rainfall) and recorded during the trials. Disease severity reached levels greater than 30% in Piracicaba and Guaíra in the plantings between December and January. Lower values of AUDPC occurred in later plantings at both locations. The epidemic rate was positively correlated (P < 0.05) with the mean daily temperatures and negatively correlated with hours of relative humidity >90%. The AUDPC was not correlated with any weather variable. The AUDPCi was negatively related to both variables connected to humidity, but not to rain. Long periods (mostly >13 h day-1) of relative humidity >90% (that corresponded to leaf wetness) occurred in Castro. Severity of southern rust in maize has always been low in Castro, thus the negative correlations between disease and the two humidity variables.

Influence of the synthesis conditions on the characteristics and metal adsorption properties of the 3-(1,4-phenylenediamine)propylsilica xerogel

The hybrid 3-(1,4-phenylenediamine)propylsilica xerogel was obtained starting from two different organic precursor quantity (5 and 8 mmol) to 22 mmol of TEOS, in the synthesis. The xerogel samples were characterized by using CHN elemental analysis, N2 adsorption-desorption isotherms, infrared thermal analysis. The xerogel was used as metal sorbent for Cu2+, Cd2+ and Pb2+ in aqueous solution with concentration range of 10-3 to 10-5 mmol l-1. The quantity of organic precursor added in the synthesis influences the characteristics of the xerogel as morphology and thermal stability, as well as the metal adsorption capacity.

Hume, liberty and the object of moral evaluation

Hume's project concerning the conflict between liberty and necessity is ";reconciliatory";. But what is the nature of Hume's project? Does he solve a problem in metaphysics only? And when Hume says that the dispute between the doctrines of liberty and necessity is merely verbal, does he mean that there is no genuine metaphysical dispute between the doctrines? In the present essay I argue for: (1) there is room for liberty in Hume's philosophy, and not only because the position is pro forma compatibilist, even though this has importance for the recognition that Hume's main concern when discussing the matter is with practice; (2) the position does not involve a ";subjectivization"; of every form of necessity: it is not compatibilist because it creates a space for the claim that the operations of the will are non-problematically necessary through a weakning of the notion of necessity as it applies to external objects; (3) Hume holds that the ordinary phenomena of mental causation do not preempt the atribuition of moral responsibility, which combines perfectly with his identification of the object of moral evaluation: the whole of the character of a person, in relation to which there is, nonetheless, liberty. I intend to support my assertions by a close reading of what Hume states in section 8 of the first Enquiry.

Sobre a natureza da teoria moral de Hume

Este artigo discute duas variedades de interpretação para a teoria moral de Hume. De um lado, ela é representada como uma forma de subjetivismo e, de outro, como uma forma de realismo. Ao final, é proposto que esta filosofia pode ser melhor descrita como uma forma de intersubjetivismo.

Considerações sobre o fundamento moral da propriedade

Para Hugo Grotius a propriedade era originalmente coletiva, e os homens tinham, de comum acordo, decidido dividi-la, o que havia feito nascer a propriedade privada. Como a propriedade privada devia ser garantida pelo governo, ela só podia ser uma emanação deste. O problema dessa análise, para John Locke, era que ela era perfeitamente compatível com o absolutismo, pois um monarca podia garantir essa propriedade. Como Locke funda a propriedade sobre a lei natural, sua teoria da prioridade refuta, ao mesmo tempo, as teorias de Sir Robert Filmer e de Grotius e Samuel Pufendorf. A teoria da propriedade de Locke garante, por fim, a liberdade dos indivíduos.

Uma filosofia moral negativa?

Este artigo apresenta a filosofia moral de Adorno baseado no seu esboço na Dialética do Esclarecimento, a partir de duas hipóteses principais: a importância do fundo mimético e animal na adaptação do ser humano, definido primeiramente como um ser sofredor e fraco; a importância da denegação desse fundo na edificação das normas ideológicas nazistas e nas práticas de tortura. Adorno reivindica uma moral ligada não à obrigação de obedecer às normas sociais, mas à aceitação dessa dimensão animal e sofredora (zoè) do ser humano e à solicitude em relação a ela.

Falácia naturalista e naturalismo moral: do é ao deve mediante o quero

O objetivo deste texto é discutir alguns argumentos contra a aceitação da falácia naturalista. Pretende-se mostrar aspectos que parecem corretos na argumentação dos que recusam aquela falácia, e, a despeito de seus acertos, demonstrar que estão fundamentalmente errados. O eixo para este desfecho é a reformulação da falácia em termos da recusa da implicação entre o ser e o querer. Espera-se, assim, tornar mais claras as relações - e a ausência delas - entre verdade e moral, bem como abrir espaço para a defesa de um naturalismo moral não comprometido com a existência de fatos morais. Este texto está dividido em cinco partes. Na primeira, apresenta-se a falácia naturalista de acordo com Moore; na segunda, distingue-se essa entre as formulações de Moore e de Hume; na terceira, apresentam-se objeções à interdição da passagem do "é" ao "deve" e se formulam respostas a essas objeções; na quarta, reapresenta-se o problema da interdição entre "é" e "deve" e se focaliza uma solução alternativa a ele mediante o querer; e, finalmente, na quinta parte, elaboram-se algumas conclusões acerca do naturalismo e do realismo na moral.

Montaigne, leitor de sexto empírico: a crítica da filosofia moral

O objetivo deste artigo é examinar como Montaigne retoma, na sua crítica das filosofias morais e, especialmente, da existência de leis naturais, a proposta por Sexto Empírico acerca do mesmo tema ao final das Hipotiposes Pirronianas. Pretendo mostrar que, para além das consideráveis similaridades, o modo como Montaigne relaciona razão, natureza e costume, confere um perfil próprio à sua reconstrução do pirronismo, particularmente visível na sua compreensão da oposição entre critério de verdade e critério de ação. Igualmente, sustento que essa distinção, proveniente do pirronismo, ocupará um lugar central na sua reflexão moral.