Unsaturated liquid percolation flow through nonwetted packed beds

The unsaturated flow of liquid through packed beds of large particles was studied using six different liquids, all with contact angles greater than 90degrees on the bed packing (wax spheres of 9, 15 and 19.4 mm diameter). The liquid flow was discrete in nature, as drops for low flow rates and rivulets for high flow rates. For unsaturated liquid flows, the actual percolation velocity, not superficial velocity, should be used to characterize the flow. The percolation velocity did not vary with packed-bed depth, but was a strong function of liquid flow rate, liquid and particle properties. Effects of liquid and particle properties (but not flow rate) are well captured by a simple correlation between the liquid-particle friction factor and Reynolds number based on actual percolation velocities. Liquid dispersion, characterized by the maximum dispersion angle, varies significantly with liquid and particle properties. The tentative correlation suggested here needs further validation for a wider range of conditions.

Nitrate in soil humic acids revealed by N-14 nuclear magnetic resonance spectroscopy

Ecosystem management such as plant residue retention and prescribed burning can significantly affect soil organic matter (SOM) composition and, thereby, the closely associated carbon (C) and nitrogen (N) cycling processes, which underpin terrestrial ecosystem productivity and sustainability. Humic acid (HA) is an important SOM component and its chemical composition has attracted much attention. Here we report the first application of N-14 nuclear magnetic resonance (NMR) spectroscopy to soil HA study, revealing the surprising existence of nitrate-N and ammonia-N in the HAs. This newly discovered HA nitrate-N, though in a relatively low concentrations, is closely related to soil N availability and responsive to plant residue management regimes in contrasting forest ecosystems. The HA nitrate-N may be a useful and sensitive biochemical indicator of SOM quality in response to different ecosystem management regimes.

Crisis, change, and institutions in forest management: the Wet Tropics of northeastern Australia

This paper tests the four-phase heuristic model of change in resource management regimes developed by Gunderson et al. (1995. In: Barriers and Bridges to the Renewal of Ecosystems and Institutions. Columbia University Press, New York, pp. 489-533) by applying it to a case analysis of rainforest management in northeastern Australia. The model suggests that resource management regimes change in four phases: (i) crisis caused by external factors, (ii) a search for alternative management solutions, (iii) creation of a new management regime, and (iv) bureaucratic implementation of the new arrangements. The history of human use arid management of the tropical forests of this region is described and applied to this model. The ensuing analysis demonstrates that: (i) resource management tends to be characterized by a series of distinct eras; (ii) changes to management regimes are precipitated by crisis; and (iii) change is externally generated. The paper concludes by arguing that this theoretical perspective oil institutional change in resource management systems has wider utility. (C) 2002 Elsevier Science Ltd. All rights reserved.

delta N-15 values of tropical savanna and monsoon forest species reflect root specialisations and soil nitrogen status

A large number of herbaceous and woody plants from tropical woodland, savanna, and monsoon forest were analysed to determine the impact of environmental factors (nutrient and water availability, fire) and biological factors (microbial associations, systematics) on plant delta(15)N values. Foliar delta(15)N values of herbaceous and woody species were not related to growth form or phenology, but a strong relationship existed between mycorrhizal status and plant delta(15)N. In woodland and savanna, woody species with ectomycorrhizal (ECM) associations and putative N-2-fixing species with ECM/arbuscular (AM) associations had lowest foliar delta(15)N values (1.0-0.6parts per thousand), AM species had mostly intermediate delta(15)N values (average +0.6parts per thousand), while non-mycorrhizal Proteaceae had highest delta(15)N values (+2.9 to +4.1parts per thousand). Similar differences in foliar delta(15)N were observed between AM (average 0.1 and 0.2parts per thousand) and non-mycorrhizal (average +0.8 and +0.3parts per thousand) herbaceous species in woodland and savanna. Leguminous savanna species had significantly higher leaf N contents (1.8-2.5% N) than non-fixing species (0.9-1.2% N) indicating substantial N acquisition via N-2 fixation. Monsoon forest species had similar leaf N contents (average 2.4% N) and positive delta(15)N values (+0.9 to +2.4parts per thousand). Soil nitrification and plant NO3- use was substantially higher in monsoon forest than in woodland or savanna. In the studied communities, higher soil N content and nitrification rates were associated with more positive soil delta(15)N and plant delta(15)N. In support of this notion, Ficus, a high NO3- using taxa associated with NO3- rich sites in the savanna, had the highest delta(15)N values of all AM species in the savanna. delta(15)N of xylem sap was examined as a tool for studying plant delta(15)N relations. delta(15)N of xylem sap varied seasonally and between differently aged Acacia and other savanna species. Plants from annually burnt savanna had significantly higher delta(15)N values compared to plants from less frequently burnt savanna, suggesting that foliar N-15 natural abundance could be used as marker for assessing historic fire regimes. Australian woodland and savanna species had low leaf delta(15)N and N content compared to species from equivalent African communities indicating that Australian biota are the more N depauperate. The largest differences in leaf delta(15)N occurred between the dominant ECM Australian and African savanna (miombo) species, which were depleted and enriched in N-15, respectively. While the depleted delta(15)N of Australian ECM species are similar to those of previous reports on ECM species in natural plant communities, the N-15-enriched delta(15)N of African ECM species represent an anomaly.

Dry matter production and allocation in Eucalyptus cloeziana and Eucalyptus argophloia seedlings in response to soil water deficits

Effects of soil water availability on seedling growth, dry matter production and allocation were determined for Gympie ( humid coastal) and Hungry Hills ( dry inland) provenances of Eucalyptus cloeziana F. Muell. and for E. argophloia Blakely ( dry inland) species. Seven-month-old seedlings were subjected to well-watered (100% field capacity, FC), moderate (70% FC) and severe (50% FC) soil water regimes in a glasshouse environment for 14 wk. There were significant differences in seedling growth, biomass production and allocation patterns between species. E. argophloia produced twice as much biomass at 100% FC, and more than three times as much at 70% and 50% FC than did either E. cloeziana provenance. Although the humid provenance of E. cloeziana had a greater leaf area at 100% FC conditions than did the dry provenance, total biomass production did not differ significantly. Both E. cloeziana provenances were highly sensitive to water deficits. E. argophloia allocated 10% more biomass to roots than did E. cloeziana. Allometric analyses indicated that relative biomass allocation patterns were significantly affected by genotype but not by soil water availability. These results have implications for taxon selection for cultivation in humid and subhumid regions.

Photosynthetic responses of the coral Montipora digitata to cold temperature stress

Coral bleaching events have become more frequent and widespread, largely due to elevated sea surface temperatures. Global climate change could lead to increased variability of sea surface temperatures, through influences on climate systems, e.g. El Nino Southern Oscillation (ENSO). Field observations in 1999, following a strong ENSO, revealed that corals bleached in winter after unusually cold weather. To explore the basis for these observations, the photosynthetic responses of the coral species Montipora digitata Studer were investigated in a series of temperature and light experiments. Small replicate coral colonies were exposed to ecologically relevant lower temperatures for varying durations and under light regimes that ranged from darkness to full sunlight. Photosynthetic efficiency was analyzed using a pulse amplitude modulated (PAM) fluorometer (F-0, F-m, F-v/F-m), and chlorophyll a (chl a) content and symbiotic dinoflagellate density were analyzed with spectrophotometry and microscopy, respectively. Cold temperature stress had a negative impact on M digitata colonies indicated by decreased photosynthetic efficiency (F-v/F-m), loss of symbiotic dinoflagellates and changes in photosynthetic pigment concentrations. Corals in higher light regimes were more susceptible to cold temperature stress, Moderate cold stress resulted in photoacclimatory responses, but severe cold stress resulted in photodamage, bleaching and increased mortality. Responses to cold temperature stress of M digitata appeared similar to that observed in corals exposed to warmer than normal temperatures, suggesting a common mechanism. The results of this study suggest that corals and coral reefs may also be impacted by exposure to cold as well as warm temperature extremes as climate change occurs.

Microstructural evolution of the Serido Belt, NE-Brazil: the effect of two tectonic events on development of c-axis preferred orientation in quartz

The polyphase evolution of the Serido Belt (NE-Brazil) includes D, crust formation at 2.3-2.1 Ga, D-2 thrust tectonics at 1.9 Ga and crustal reworking by D-3 strike-slip shear zones at 600 Ma. Microstructural investigations within mylonites associated with D-2 and D-3 events were used to constrain the tectono-thermal evolution of the belt. D-2 shear zones commenced at deeper crustal levels and high amphibolite facies conditions (600-650 degreesC) through grain boundary migration, subgrain rotation and operation of quartz Q-prism slip. Continued shearing and exhumation of the terrain forced the re-equilibration of high-T fabrics and the switching of slip systems from (c)-prism to positive and negative (a)-rhombs. During D-3, enhancement of ductility by dissipation of heat that came from syn-D-3 granites developed wide belts of amphibolite facies mylonites. Continued shearing, uplift and cooling of the region induced D-3 shear zones to act in ductile-brittle regimes, marked by fracturing and development of thinner belts of greenschist facies mylonites. During this event, switching from (a)-prism to a basal slip indicates a thermal path from 600 to 350 degreesC. Therefore, microstructures and quartz c-axis fabrics in polydeformed rocks from the Serido Belt preserve the record of two major events, which includes contrasting deformation mechanisms and thermal paths. (C) 2003 Elsevier Ltd. All rights reserved.

Biaxial failure model for fiber reinforced concrete

Steel fiber reinforced concrete (SFRC) is widely applied in the construction industry. Numerical elastoplastic analysis of the macroscopic behavior is complex. This typically involves a piecewise linear failure curve including corner singularities. This paper presents a single smooth biaxial failure curve for SFRC based on a semianalytical approximation. Convexity of the proposed model is guaranteed so that numerical problems are avoided. The model has sufficient flexibility to closely match experimental results. The failure curve is also suitable for modeling plain concrete under biaxial loading. Since this model is capable of simulating the failure states in all stress regimes with a single envelope, the elastoplastic formulation is very concise and simple. The finite element implementation is developed to demonstrate the conciseness and the effectiveness of the model. The computed results display good agreement with published experimental data.

The Lake Tekapo experiment (LTEX): An investigation of atmospheric boundary layer processes in complex terrain

A research program on atmospheric boundary layer processes and local wind regimes in complex terrain was conducted in the vicinity of Lake Tekapo in the southern Alps of New Zealand, during two 1-month field campaigns in 1997 and 1999. The effects of the interaction of thermal and dynamic forcing were of specific interest, with a particular focus on the interaction of thermal forcing of differing scales. The rationale and objectives of the field and modeling program are described, along with the methodology used to achieve them. Specific research aims include improved knowledge of the role of surface forcing associated with varying energy balances across heterogeneous terrain, thermal influences on boundary layer and local wind development, and dynamic influences of the terrain through channeling effects. Data were collected using a network of surface meteorological and energy balance stations, radiosonde and pilot balloon soundings, tethered balloon and kite-based systems, sodar, and an instrumented light aircraft. These data are being used to investigate the energetics of surface heat fluxes, the effects of localized heating/cooling and advective processes on atmospheric boundary layer development, and dynamic channeling. A complementary program of numerical modeling includes application of the Regional Atmospheric Modeling System (RAMS) to case studies characterizing typical boundary layer structures and airflow patterns observed around Lake Tekapo. Some initial results derived from the special observation periods are used to illustrate progress made to date. In spite of the difficulties involved in obtaining good data and undertaking modeling experiments in such complex terrain, initial results show that surface thermal heterogeneity has a significant influence on local atmospheric structure and wind fields in the vicinity of the lake. This influence occurs particularly in the morning. However, dynamic channeling effects and the larger-scale thermal effect of the mountain region frequently override these more local features later in the day.

Effects of soil water availability on water use efficiency of Eucalyptus cloeziana and Eucalyptus argophloia plants

Effects of soil water availability on transpiration efficiency (WUET), instantaneous water use efficiency (WUEi) and carbon isotope composition (delta(13)C) were investigated in 7-month-old plants of humid coastal (Gympie) and dry inland ( Hungry Hills) provenances of Eucalyptus cloeziana F. Muell. and in a dry inland provenance of E. argophloia Blakely (Chinchilla), supplied with 100 (W-100), 70 (W-70) and 50% (W-50) of their water requirements. At W-100, WUET of the three provenances were not significantly different but as available soil moisture decreased, E. argophloia produced greater biomass and demonstrated significantly higher WUET than either E. cloeziana provenance. Midday WUEi was not significantly affected by watering regime within each provenance but was lowest in E. argophloia. A decrease in soil water availability caused a consistent increase in delta(13)C values in all three provenances; however, delta(13)C values of E. argophloia in all three water regimes were significantly lower than those of E. cloeziana provenances, which did not differ significantly from each other. For all three provenances, delta(13)C was not correlated with WUEi but height and root collar diameter were negatively correlated to delta(13)C. There was little evidence of differences in delta(13)C, WUET and WUEi between E. cloeziana provenances but clear differences between E. cloeziana and E. argophloia. The high WUET, low WUEi and low delta(13)C for E. argophloia may have implications in the selection of Eucalyptus provenances for commercial forestry in low-rainfall regions.

Inova????es na Gest??o P??blica Federal: balan??o de cinco anos do Concurso organizado pela ENAP

Este livro apresenta uma an??lise de informa????es consolidadas e sistematizadas sobre experi??ncias vencedoras do Concurso de Inova????es na Gest??o P??blica Federal entre os anos de 1996 a 2000, para oferecer algumas sugest??es para o debate aos que est??o engajados no processo de aperfei??oamento do setor p??blico ou se interessam pelo tema

Sistema integrado de informa????es previdenci??rias: SIPREV

No ano de 1998, a quest??o espec??fica da gest??o da previd??ncia dos servidores p??blicos da Uni??o, Estados e Munic??pios emergiu como fator cr??tico, em face ao aumento exponencial do d??ficit financeiro e atuarial e do impacto desse desequil??brio nas contas da Uni??o. Em raz??o disso, o Poder Executivo Federal patrocinou ampla reforma legislativa da mat??ria previdenci??ria p??blica, mediante aprova????o da Emenda Constitucional n?? 20/98 e da Lei 9.717/98, a chamada Lei Geral da Previd??ncia Social, calcada em preceitos que possam assegurar equil??brio financeiro e atuarial dos Regimes Pr??prios de Previd??ncia Social - RPPS. A situa????o, ??quela altura, da previd??ncia gerida por Estados e Munic??pios, apresentava-se preocupante, especialmente quanto aos aspectos estruturais, operacionais e t??cnicos, incluindo base de informa????es desatualizadas, dispersas e pulverizadas nos diversos ??rg??os de cada ente federado, bem como gestores e t??cnicos desqualificados para atender aos novos preceitos estabelecidos pela Reforma Previdenci??ria. Para concretizar a inten????o do legislador federal, a Uni??o, por interm??dio do MPAS, deveria orientar, supervisionar, acompanhar e apoiar a reforma e gest??o dos regimes pr??prios de previd??ncia social. Para tanto, inicia-se, ent??o, no ??mbito do pr??prio MPAS, o processo de concep????o institucional do SIPREV. O SIPREV possibilita in??meros benef??cios ?? sociedade, usu??rios, operadores e gestores previdenci??rios da Uni??o, Estados e Munic??pios, elencados a seguir: transpar??ncia das contas p??blicas, comprometimento dos segurados com a gest??o previdenci??ria, integra????o da Previd??ncia Social P??blica, dissemina????o de ferramentas especializadas de gest??o previdenci??ria, planejamento previdenci??rio, preven????o contra fraudes e informa????es hist??ricas

Sistem??tica de avalia????o e prioriza????o de investimentos em equipamentos

Sistem??tica de planejamento de investimentos para o hospital universit??rio com a cria????o de um Plano Diretor de Investimentos em Equipamentos que leva em considera????o o contexto de alta complexidade do ambiente e visa atender ??s necessidades de envolvimento e participa????o dos profissionais das diversas ??reas. Os crit??rios criados para a prioriza????o dos investimentos avaliam a contribui????o para otimizar a renda/produtividade, a viabilidade de implanta????o, a contribui????o ao desenvolvimento da excel??ncia, a prioridade de cada investimento no Servi??o e a criticidade do investimento. Hoje, os investimentos em equipamentos est??o sendo adquiridos conforme a prioridade que a comunidade interna definiu, dentro de uma avalia????o objetiva de cada investimento

Aprendizagem ao alcance de todos: a experi??ncia do governo canadense em educa????o por meio eletr??nico

Este trabalho publicado originalmente pelo Canad?? School of Public Service (CSPS), e elaborado a partir dos estudos e da experi??ncia em aprendizagem por meio eletr??nico (e-learning) do setor p??blico canadense, tem por objetivo disseminar a utiliza????o dessa modalidade de ensino a educadores e t??cnicos que trabalhem diretamente com Educa????o a Dist??ncia (EAD) no setor p??blico. Ao procurar esclarecer o processo de aprendizagem, do ponto de vista dos conceitos, das t??cnicas e da operacionaliza????o, o trabalho lan??a luz sobre as vantagens e o potencial que essa modalidade de ensino apresenta para as organiza????es p??blicas, apontando inclusive as armadilhas e obst??culos que devem ser observados em seu uso

Participa????o social: textos para discuss??o

O sexto volume da s??rie Inova????o na Gest??o P??blica apresenta uma colet??nea de tr??s textos sobre a quest??o da participa????o social. O primeiro texto, produzido pelo professor Mark Evans, no ??mbito da coopera????o do Minist??rio do Planejamento Or??amento e Gest??o com a Uni??o Europeia, fornece conhecimentos, tanto acad??micos quanto pr??ticos, sobre as pr??ticas europeias de ponta relacionadas ?? participa????o social. Isso envolve a aplica????o de uma gama de ferramentas para identificar e compartilhar melhores pr??ticas, diagnosticas o que funciona em diferentes contextos sociais, compatibilizar deferentes m??todos de envolvimento com diferentes fins e identificar onde o envolvimento do cidad??o pode ser ??til em quatro pontos de decis??o no processo pol??tico (dire????o estrat??gica, formula????o de pol??ticas, execu????o de pol??ticas e aprendizagem pol??tica). Al??m disso, o estudo tamb??m oferece uma sele????o de estudos de caso de toada Europa, a cada ponto de decis??o. O segundo texto, elaborado por Elisabete Ferrarezi e Clarice G. Oliveira e apresentado no V Congresso Consad de Gest??o P??blica, ocorrido em Bras??lia em junho de 2012, problematiza a efetividade dos espa??os e mecanismos de participa????o social do Brasil do ponto de vista do processamento de pol??ticas p??blicas dentro do aparato burocr??tico a partir de conceitos derivados das teorias de complexidade, participa????o e burocracia com a inten????o de contribuir para o debate sobre o aperfei??oamento desse campo. O ??ltimo texto, desenvolvido por N??ria Cunill Grau em setembro de 2012, no ??mbito da coopera????o entre o Minist??rio do Planejamento, Or??amento e Gest??o, o Banco Mundial e o Programa das Na????es Unidas para o Desenvolvimento (PNUD), cont??m um levantamento, realizado em 2009, dos diferentes instrumentos que facilitam a participa????o e o controle social na Administra????o P??blica Federal do Brasil associados aos diferentes modelos organizacionais existentes