Subspace wavepacket evolution with Newton polynomials

Time-dependent wavepacket evolution techniques demand the action of the propagator, exp(-iHt/(h)over-bar), on a suitable initial wavepacket. When a complex absorbing potential is added to the Hamiltonian for combating unwanted reflection effects, polynomial expansions of the propagator are selected on their ability to cope with non-Hermiticity. An efficient subspace implementation of the Newton polynomial expansion scheme that requires fewer dense matrix-vector multiplications than its grid-based counterpart has been devised. Performance improvements are illustrated with some benchmark one and two-dimensional examples. (C) 2001 Elsevier Science B.V. All rights reserved.

Habitat complexity, spatial interference, and "minimum risk distribution": a framework for population stability

In the past century, the debate over whether or not density-dependent factors regulate populations has generally focused on changes in mean population density, ignoring the spatial variance around the mean as unimportant noise. In an attempt to provide a different framework for understanding population dynamics based on individual fitness, this paper discusses the crucial role of spatial variability itself on the stability of insect populations. The advantages of this method are the following: (1) it is founded on evolutionary principles rather than post hoc assumptions; (2) it erects hypotheses that can be tested; and (3) it links disparate ecological schools, including spatial dynamics, behavioral ecology, preference-performance, and plant apparency into an overall framework. At the core of this framework, habitat complexity governs insect spatial variance. which in turn determines population stability. First, the minimum risk distribution (MRD) is defined as the spatial distribution of individuals that results in the minimum number of premature deaths in a population given the distribution of mortality risk in the habitat (and, therefore, leading to maximized population growth). The greater the divergence of actual spatial patterns of individuals from the MRD, the greater the reduction of population growth and size from high, unstable levels. Then, based on extensive data from 29 populations of the processionary caterpillar, Ochrogaster lunifer, four steps are used to test the effect of habitat interference on population growth rates. (1) The costs (increasing the risk of scramble competition) and benefits (decreasing the risk of inverse density-dependent predation) of egg and larval aggregation are quantified. (2) These costs and benefits, along with the distribution of resources, are used to construct the MRD for each habitat. (3) The MRD is used as a benchmark against which the actual spatial pattern of individuals is compared. The degree of divergence of the actual spatial pattern from the MRD is quantified for each of the 29 habitats. (4) Finally, indices of habitat complexity are used to provide highly accurate predictions of spatial divergence from the MRD, showing that habitat interference reduces population growth rates from high, unstable levels. The reason for the divergence appears to be that high levels of background vegetation (vegetation other than host plants) interfere with female host-searching behavior. This leads to a spatial distribution of egg batches with high mortality risk, and therefore lower population growth. Knowledge of the MRD in other species should be a highly effective means of predicting trends in population dynamics. Species with high divergence between their actual spatial distribution and their MRD may display relatively stable dynamics at low population levels. In contrast, species with low divergence should experience high levels of intragenerational population growth leading to frequent habitat-wide outbreaks and unstable dynamics in the long term. Six hypotheses, erected under the framework of spatial interference, are discussed, and future tests are suggested.

Monitoring hotel performance

There is a pressing need to address productivity analysis in the hospitality industry if hotels are to exist as sustainable business entities in rapidly maturing markets. Unfortunately, productivity ratios commonly used by managers are narrowly defined. This study illustrates data envelopment analysis of cross-sectional data that benchmark hotels on observed best performances. Data envelopment analysis enables management to integrate unlike multiple inputs and outputs to make simultaneous comparisons. Findings from the cross-sectional data suggest that some of the hotels have the potential to reduce number of beds and number of part-time staff while increasing revenue.

Control of nitrate recirculation flow in predenitrification systems

The control of the nitrate recirculation flow in a predenitrification system is addressed. An elementary mass balance analysis on the utilisation efficiency of the influent biodegradable COD (bCOD) for nitrate removal indicates that the control problem can be broken down into two parts: maintaining the anoxic zone anoxic (i.e. nitrate is present throughout the anoxic zone) and maximising the usage of influent soluble bCOD for denitrification. Simulation studies using the Simulation Benchmark developed in the European COST program show that both objectives can be achieved by maintaining the nitrate concentration at the outlet of the anoxic zone at around 2 mgN/L. This setpoint appears to be robust towards variations in the influent characteristics and sludge kinetics.

Benchmarking nitrogen removal suspended-carrier biofilm systems using dynamic simulation

We are witnessing an enormous growth in biological nitrogen removal from wastewater. It presents specific challenges beyond traditional COD (carbon) removal. A possibility for optimised process design is the use of biomass-supporting media. In this paper, attached growth processes (AGP) are evaluated using dynamic simulations. The advantages of these systems that were qualitatively described elsewhere, are validated quantitatively based on a simulation benchmark for activated sludge treatment systems. This simulation benchmark is extended with a biofilm model that allows for fast and accurate simulation of the conversion of different substrates in a biofilm. The economic feasibility of this system is evaluated using the data generated with the benchmark simulations. Capital savings due to volume reduction and reduced sludge production are weighed out against increased aeration costs. In this evaluation, effluent quality is integrated as well.

Standardised audit of hip fractures in Europe

The objectives of this study were to evaluate the outcomes of our patients admitted with hip fractures, and to benchmark these results with other hospitals, initially in Europe and subsequently in Australia. The Standardised Audit of Hip Fractures in Europe (SAHFE) questionnaires was used as the data gathering instrument. The participants were all patients admitted to Redcliffe Hospital with a fractured neck of femur prior to surgery. This paper reports the results of the first 70 consecutive patients admitted to Redcliffe Hospital with a fractured neck of femur from November 1st 2000. The main outcome measures were mobility, independence, residence prior to fracture; type of fracture and surgical repair; and time to surgery, survival rates and discharge destination. Results: 43 patients were admitted from home, but only 13 returned home directly from the orthopaedic ward. It is hoped that most of the 26 transferred to the rehabilitation ward will ultimately return home. 7 patients died, these were aged 82 to 102, and all had premorbid disease. Delays in surgery were apparent for 13 patients, mainly due to administrative problems. Conclusions: We support the recommendation in the Fifteenth Scottish Intercollegiate Guidelines Network Publication on the management of hip fractures, that all units treating this condition should enter an audit to evaluate their management. (author abstract)

Detection of swallowing sounds: Methodology revisited

Cervical auscultation is in the process of gaining clinical credibility. In order for it to be accepted by the clinical community, the procedure and equipment used must first be standardized. Takahashi et al. [Dysphagia 9:54-62, 1994] attempted to provide benchmark methodology for administering cervical auscultation. They provided information about the acoustic detector unit best suited to picking up swallowing sounds and the best cervical site to place it. The current investigation provides contrasting results to Takahashi et al. with respect to the best type of acoustic detector unit to use for detecting swallowing sounds. Our study advocates an electret microphone as opposed to an accelerometer for recording swallowing sounds. However, we agree on the optimal placement site. We conclude that cervical auscultation is within reach of the average dysphagia clinic.

Engineering closure of an open pit gold operation in a semi-arid climate

Along with material characteristics and geometry, the climate in which a mine is located can have a dramatic effect on the appropriate options for rehabilitation. The paper outlines the setting, mining, milling and waste disposal at Kidston Gold Mine's open pit operations in the semi-arid climate of North Queensland, Australia, before focusing on the engineering aspects of the rehabilitation of Kidston. The mine took a holistic and proactive approach to rehabilitation, and was prepared to demonstrate a number of innovative approaches, which are described in the paper. Engineering issues that had to be addressed included the geotechnical stability and deformation of waste rock dumps, including a 240 m high in-pit dump: the construction and performance monitoring of a “store and release” cover over potentially acid forming mineralised waste rock; erosion from the side slopes of the waste rock dumps; the in-pit co-disposal of waste rock and thickened tailings; the geotechnical stability of the tailings dam wall; the potential for erosion of bare tailings; the water balance of the tailings dam; direct revegetation of the tailings; and the pit hydrology. The rehabilitation of the mine represents an important benchmark in mine site rehabilitation best practice, from which lessons applicable worldwide can be shared.

Overseas Visitor Deaths in Australia: 1997-2000

Reassuring visitors about their health and safety is particularly important for tourist destinations since the terrorist attacks of 11 September 2001. This study examined the deaths of 1513 overseas visitors to Australia over a four-year period, and found that most deaths (76%) were due to natural causes.Among the accidental deaths, the main causes were motor vehicle crashes and water-related incidents. The study findings support a widely held view that Australia is a safe destination for overseas visitors. It also provides a safety benchmark for other tourist destinations.

Product form approximations for highly linear loss networks with trunk reservation

Admission controls, such as trunk reservation, are often used in loss networks to optimise their performance. Since the numerical evaluation of performance measures is complex, much attention has been given to finding approximation methods. The Erlang Fixed-Point (EFP) approximation, which is based on an independent blocking assumption, has been used for networks both with and without controls. Several more elaborate approximation methods which account for dependencies in blocking behaviour have been developed for the uncontrolled setting. This paper is an exploratory investigation of extensions and synthesis of these methods to systems with controls, in particular, trunk reservation. In order to isolate the dependency factor, we restrict our attention to a highly linear network. We will compare the performance of the resulting approximations against the benchmark of the EFP approximation extended to the trunk reservation setting. By doing this, we seek to gain insight into the critical factors in constructing an effective approximation. (C) 2003 Elsevier Ltd. All rights reserved.

Integrated control of nitrate recirculation and external carbon addition in a predenitrification system

The integrated control of nitrate recirculation and external carbon addition in a predenitrification biological wastewater treatment system is studied. The proposed control structure consists of four feedback control loops, which manipulate the nitrate recirculation and the carbon dosage flows in a highly coordinated manner such that the consumption of external carbon is minimised while the nitrate discharge limits (based on both grab and composite samples) are met. The control system requires the measurement of the nitrate concentrations at the end of both the anoxic and the aerobic zones. Distinct from ordinary control systems, which typically minimise the variation in the controlled variables, the proposed control system essentially maximises the diurnal variation of the effluent nitrate concentration and through this maximises the use of influent COD for denitrification, thus minimising the requirement for external carbon source. Simulation studies using a commonly accepted simulation benchmark show that the controlled system consistently achieves the designated effluent quality with minimum costs.

Induction in the timed interval calculus

The Timed Interval Calculus, a timed-trace formalism based on set theory, is introduced. It is extended with an induction law and a unit for concatenation, which facilitates the proof of properties over trace histories. The effectiveness of the extended Timed Interval Calculus is demonstrated via a benchmark case study, the mine pump. Specifically, a safety property relating to the operation of a mine shaft is proved, based on an implementation of the mine pump and assumptions about the environment of the mine. (C) 2002 Elsevier Science B.V. All rights reserved.

Plano de implementa????o do projeto de desenvolvimento de capacidade de governan??a

Desde a d??cada de 1990, o Governo Federal brasileiro vem implementando uma agenda ambiciosa de reformas do Estado, centradas na redu????o da pobreza e na melhoria da efici??ncia dos servi??os p??blicos. As principais prioridades, conforme previstas no Plano Plurianual (PPA) para o per??odo 2003-2007, s??o as seguintes: inclus??o social e redu????o da desigualdade; crescimento econ??mico com gera????o de emprego; distribui????o de renda e respeito ao meio ambiente; promo????o e amplia????o dos direitos de cidadania; e fortalecimento da democracia. No in??cio de 2006, o Governo criou a Pol??tica Nacional de Desenvolvimento de Pessoal (Decreto 5.707), com o objetivo de melhorar e aumentar a efici??ncia e a efic??cia na presta????o de servi??os p??blicos. No marco dessa pol??tica recente, as escolas de administra????o p??blica desempenham um papel fundamental na identifica????o das compet??ncias que precisam ser desenvolvidas nas institui????es do governo, bem como na implementa????o de pol??ticas de capacita????o para os servidores p??blicos, diretamente e/ou em parceria com escolas de governo nos n??veis federal, estadual ou local. O Canad?? tamb??m est?? criando uma estrutura para levantar as compet??ncias necess??rias para os servidores p??blicos e desenvolv??-las como um componente da Renova????o do Servi??o P??blico em todo o governo. Como institui????es l??deres no desenvolvimento de compet??ncias de servidores p??blicos, a Canada School of Public Service (CSPS) e a Escola Nacional de Administra????o P??blica (ENAP) firmaram uma parceria para implementar o Projeto de Desenvolvimento de Capacidade de Governan??a no Brasil. A finalidade do Projeto ?? melhorar a capacidade de servidores p??blicos federais, estaduais e municipais do Brasil para desenvolver e implementar programas de capacita????o e gerenciar pol??ticas p??blicas descentralizadas. Espera-se que essa parceria e o resultante compartilhamento de experi??ncias em capacita????o para governan??a efetiva contribuam para a redu????o da pobreza e das desigualdades no Brasil, por meio do desenvolvimento de compet??ncias de servidores na presta????o de servi??os p??blicos eficazes e eficientes, voltados para o cidad??o. O Projeto re??ne, al??m das duas principais Escolas de Governo no Canad?? e no Brasil, seis Escolas Brasileiras de Administra????o P??blica regionais e duas renomadas Institui????es Acad??micas Canadenses ??? a Queen???s University e a Western Ontario University. O Minist??rio do Desenvolvimento Social e Combate ?? Fome (MDS) e tr??s Secretarias Especiais do Governo Federal ??? Ra??a (SEPPIR), Direitos Humanos (SEDH) e Pol??ticas para as Mulheres (SPM) ??? tamb??m se envolver??o nas atividades de compartilhamento de conhecimentos com o Human Resources and Skills Development Canada (HRSDC) e a Canada Public Service Agency (CPSA). A CIDA fornecer?? CND$1.700.000 por meio do Programa Brasil-Canad?? de Interc??mbio de Conhecimentos para a Promo????o da Equidade (PIPE). A contribui????o da ENAP ser?? de CND$1.069.707 em esp??cie. A CSPS contribuir?? com cursos, al??m de conhecimentos e suporte t??cnicos, avaliados em CND$1.000.000. Aproveitando a parceria entre a CSPS e a ENAP, que resultou na transfer??ncia e na adapta????o bem sucedidas de cursos e metodologias canadenses, o novo projeto extrapola o n??cleo do servi??o p??blico em Bras??lia, alcan??ando escolas de governo em regi??es brasileiras em situa????o de desvantagem. ?? semelhan??a do papel da CSPS no primeiro projeto, a ENAP fortalecer?? a capacidade das escolas parceiras regionais para capacitar servidores p??blicos envolvidos na presta????o de servi??os aos brasileiros. O interc??mbio estruturado entre Minist??rios dos Governos canadense e brasileiro tamb??m aplicar?? a aprendizagem mais diretamente a quest??es de pol??ticas e programas sociais do Brasil. O desafio assumido neste Projeto ?? a adapta????o de conhecimentos e aprendizagem, com vistas a melhorar a implementa????o de pol??ticas e programas sociais. Para tanto, a CSPS e a ENAP introduzir??o novos cursos nos curr??culos das escolas parceiras e incorporar??o novos m??todos e tecnologias de aprendizagem como, por exemplo, comunidades de pr??tica virtuais e um componente de tutoria (mentoring) envolvendo o Human Resources and Skills Development Canada e o Minist??rio do Desenvolvimento Social e Combate ?? Fome do Brasil. Seis institui????es da Rede Nacional de Escolas de Governo do Brasil e do Programa de Parceria da ENAP foram selecionadas e convidadas a se unir ?? CSPS e ?? ENAP nesse novo Projeto: a Universidade Federal do Par?? (UFPA), de Bel??m (estado do Par?? ??? regi??o Norte); a Funda????o Joaquim Nabuco (FUNDAJ), de Recife (Pernambuco ??? Nordeste); a Universidade Corporativa do Servi??o P??blico / Secretaria de Administra????o do Estado da Bahia (UCS/SAEB), Salvador (Bahia ??? Nordeste); a Escola de Governo do Mato Grosso do Sul (ESCOLAGOV), Campo Grande (estado do Mato Grosso do Sul ??? Centro-Oeste); a Escola Nacional de Ci??ncias Estat??sticas / Instituto Brasileiro de Geografia e Estat??stica (ENCE/IBGE), Rio de Janeiro (estado do Rio de Janeiro ??? Sudeste); e o Instituto Municipal de Administra????o P??blica (IMAP) de Curitiba (Paran?? ??? Sul). Essas escolas de refer??ncia foram escolhidas segundo sua capacidade de trabalhar como p??los de pr??ticas inovadoras em pol??ticas p??blicas e disseminar os benef??cios do Projeto para outras escolas em suas regi??es, por meio da Rede Nacional coordenada pela ENAP. O objetivo dessa parceria ?? fortalecer as escolas de governo locais, para que estas desenvolvam, por meio de eventos de aprendizagem, compet??ncias em servidores p??blicos, a fim de aumentar a capacidade do governo na implementa????o e gest??o de pol??ticas p??blicas. O Plano de Implementa????o do Projeto (PIP) descreve o trabalho a ser realizado por essas institui????es nos pr??ximos 30 meses, ao tempo em que serve de guia para os Parceiros do Projeto no que se refere ??s a????es e aos recursos necess??rios para a obten????o dos resultados acordados. Na medida em que o Projeto estiver em andamento e os parceiros iniciarem um interc??mbio produtivo de conhecimentos, o Plano de Trabalho Anual ser?? atualizado e revisto por meio de reuni??es anuais de avalia????o e encontros do Comit?? Diretor do Projeto, com vistas a assegurar que os resultados descritos no PIP sejam alcan??ados com sucesso

Monitorização de sistemas solares térmicos: simulação de perfis de consumo e cálculo de comportamento térmico a longo prazo

A presente dissertação assenta na monitorização de sistemas solares térmicos com incidência em perfis de consumo e cálculo de comportamento térmico a longo prazo. No início faz-se uma introdução aos temas e definições que são primordiais para uma melhor compreensão do trabalho em causa. Procedeu-se à simulação do comportamento térmico de sistemas solares térmicos, tendo como base os parâmetros de cálculo obtidos nos relatórios de ensaio. Os sistemas solares térmicos podem ser ensaiados segundo duas metodologias de cálculo diferentes. Estas metodologias estão descritas nas normas ISO 9459-2:1995 para a metodologia CSTG – Dynamic System Testing Group e ISO 9459-5:2007 para a metodologia DST – Dynamic System Testing. Neste trabalho foram utilizadas as duas metodologias mencionadas. Analisaram-se e simularam-se ainda os perfis de consumo do Anexo IV da Directiva EcoDesign tendo como objectivo definir um “benchmark” entre os diferentes sistemas solares térmicos e também saber qual é a energia primária necessária para satisfazer cada uma das necessidades dos diferentes perfis de extracção. O estudo e análise desta Directiva é bastante importante, pois é com base nela que se vai proceder à classificação e posterior rotulagem dos sistemas solares térmicos.

Development of fire-resistant (B1 & B2) winter 1 KPU foams applied by gun or straw adapter and optimization of a gun applied winter 1 KPU foam

A realização do presente trabalho teve como principais objectivos o desenvolvimento de espumas de poliuretano de um componente com propriedades de resistência à chama superiores (B1 & B2), aplicadas por pistola ou por adaptador/tubo e a optimização de uma espuma de poliuretano de um componente de inverno aplicada por pistola. Todo o trabalho desenvolvido está dividido em dois projectos distintos: i. O primeiro projecto consistiu em desenvolver espumas de um componente com propriedades de resistência à chama (classificadas como B1 e B2 de acordo com a norma alemã DIN 4102), aplicadas por pistola (GWB1 e GWB2) ou por adaptador/tubo (AWB), utilizando polióis poliésteres aromáticos modificados e aditivos retardantes de chama halogenados. Estas espumas deveriam apresentar também propriedades aceitáveis a baixas temperaturas. Após realizar várias formulações foi possível desenvolver uma espuma AWB2 com apenas 3,3% de poliol poliéster no pré-polímero e com propriedades equivalentes às da melhor espuma comercial mesmo a 5/-10 (temperatura da lata/cura da espuma em °C) e também com uma altura de chama de apenas 11 cm. A partir de duas formulações (AWB2) que passaram o Teste B2, foram obtidas também, uma espuma GWB2 e outra GWB1 com propriedades equivalentes às da melhor espuma da concorrência a -10/-10 e a 23/5, respectivamente, embora não tenham sido submetidas ao teste B2 e B1 após as modificações efectuadas. ii. O segundo projecto consistiu em optimizar uma espuma de poliuretano de um componente de inverno aplicada por pistola (GWB3). A espuma inicial tinha problemas de glass bubbles quando esta era dispensada a partir de uma lata cheia, sendo necessário ultrapassar este problema. Este problema foi resolvido diminuindo a razão de GPL/DME através do aumento da percentagem em volume de DME no pré-polímero para 14% no entanto, a estabilidade dimensional piorou um pouco. O reagente FCA 400 foi removido da formulação anterior (6925) numa tentativa de diminuir o custo da espuma, obtendo-se uma espuma aceitável a 23/23 e a 5/5, com uma redução de 4% no custo da produção e com uma redução de 5,5% no custo por litro de espuma dispensada, quando comparada com a sua antecessora. Por último, foi avaliada a influência da concentração de diferentes surfactantes na formulação 6925, verificando-se o melhoramento da estrutura celular da espuma para concentrções mais elevadas de surfactante, sendo este efeito mais notório a temperaturas mais baixas (5/5). Dos surfactantes estudados, o B 8871 mostrou o melhor desempenho a 5/5 com a concentração mais baixa, sendo portanto o melhor surfactante, enquanto o Struksilon 8003 demonstrou ser o menos adequado para esta formulação específica, apresentando piores resultados globais. Pode-se ainda acrescentar que os surfactantes L-5351, L-5352 e B 8526 também não são adequados para esta formulação uma vez que as espumas resultantes apresentam cell collapse, especialmente a 5/5. No caso dos surfactantes L-5351 e L-5352, esta propriedade piora com concentrações mais elevadas. Em cada projecto foram também efectuados testes de benchmark em determinadas espumas comerciais com o principal objectivo de comparar todos os resultados das espumas desenvolvidas, em ambos os projectos, com espumas da concorrência.