Luis Ferreira | Queensland University of Technology (original) (raw)
Papers by Luis Ferreira
E-business (B2B and B2C) is expected to dramatically change the way business is conducted. Assess... more E-business (B2B and B2C) is expected to dramatically change the way business is conducted. Assessment of the likely impact of e-business on the transport system, and hence on the natural and built environment, is thus needed. This paper reports some early findings from a study to consider e-business trends and design a procedure for rating and ranking transport impacts of
This paper describes the findings of a state-of-the-art literature review on the energy consumpti... more This paper describes the findings of a state-of-the-art literature review on the energy consumption of land based freight transport modes and outlines the development of a model to compare corridor energy consumption of road and rail options. The key parameters influencing the energy estimation and comparison procedure are identified and a methodology to compare door to door freight movement is
Lecture Notes in Computer Science, 2004
The use of grid computing technology is being boosted in last years by the growing demand of low ... more The use of grid computing technology is being boosted in last years by the growing demand of low cost computing resources and idle computing capacity in collaborative research and development environments. GridBR is a PETROBRAS project done with the collaboration of COPPE/UFRJ and IBM Brazil partnership. This project aims at grid computing technology in the information technology strategy of PETRO-BRAS Research and Development Center (CENPES). The present environment comprises a heterogeneous mix of architectures and operating systems with AIX IBM and Linux workstations providing the required support for collaborative execution of applications. The results of a genetic algorithm optimization application are presented as an example of how to take advantage of the existing grid computing infrastructure at PETROBRAS.
The aim of this paper is to present a cloudlet architecture for dashboard in Cloud and Ubiquitous... more The aim of this paper is to present a cloudlet architecture for dashboard in Cloud and Ubiquitous Manufacturing. In practice means that, with Cloud Computing adoption, Manufacturing requires management applications where ubiquity and effectiveness are enabled. If ubiquity and resources scalability, availability and capacity can be well supported by cloud, pragmatics instruments are required to support effectiveness. The architecture here presented shows the integration of enriched existing (cloud) services, as instances of resources, with layers of new services towards direct and synchronous communication between users. These Rich Internet Application (RIA) components, here named cloudlets, integration, follow dashboards organization patterns and will be supported by emergent web3.0 interaction technologies. In fact, the paper proposes a new Presentation Layer to be used in UMS and (that may be used) in any multi-layer cloud-based web application.
The main objective of this study was to validate the use of long-chain fatty acids (LCFA) as mark... more The main objective of this study was to validate the use of long-chain fatty acids (LCFA) as markers to estimate diet composition of equines fed with diets composed of herbaceous and woody species. Six crossbreed mares (434±59 kg LW) were divided in 2 groups and each group was fed one of two different diets: D1 100% Lolium perenne, D2 70% L. perenne + 30% heather (Erica spp., Calluna vulgaris). Diet composition was estimated from LCFA concentrations (C22 to C34) in diet and faeces, with (i.e. mean recovery rate of the dietary treatment that the animal belonged to) or without correction for incomplete faecal recoveries using least-squares procedures. Reulsts showed clear differences in the LCFA profiles among diet components. LCFA faecal recovery was in general incomplete and tended to decrease with carbon chain length in a curvilinear fashion (P<0.001) and was affected by diet composition (P<0.001). Results also showed that diet composition was accurately estimated with or wit...
To compare the performance and parasitic status of non-lactating goats during summer-autumn grazi... more To compare the performance and parasitic status of non-lactating goats during summer-autumn grazing (after weaning their kids) on three common vegetation types in NW Iberian Peninsula: perennial ryegrass-white clover improved pastures, heather-dominated shrublands, and gorse-dominated shrublands.
The mountainous less-favored areas of the northwest of the Iberian Peninsula are mostly covered w... more The mountainous less-favored areas of the northwest of the Iberian Peninsula are mostly covered with heathland vegetation, offering little opportunities for the development of profitable productive systems in the interests of rural people. The low nutritive value of heathlands and their high susceptibility to wildfires causes serious problems to livestock management and biodiversity conservation. The SERIDA research team on Animal Production Systems has carried out several studies in Cantabrian heathlands during the last twenty years, aiming to develop sustainable grazing systems maintaining, simultaneously, high levels of biodiversity. Research has been focused on the assessment of the nutritive quality of heathland vegetation and its potential for livestock feeding, the grazing behavior and performance of different domestic herbivore species, the establishment of improved pastures on heathland areas to get the sustainability of productive grazing systems, animal health looking at ...
To evaluate the effects of heather supplementation on diet selection, nutrient intake, and gastro... more To evaluate the effects of heather supplementation on diet selection, nutrient intake, and gastrointestinal nematode infections in goats grazing on mountain grasslands. Do goats select to feed on heather to improve their health status?
Neste trabalho apresenta-se um caso particular de "a água como recurso estruturante do desenvolvi... more Neste trabalho apresenta-se um caso particular de "a água como recurso estruturante do desenvolvimento" de uma região que desde há muitos longos anos tem influenciado o "destino" das populações, inclusivé da expansão urbana da região de Lafões e em particular de S. Pedro do Sul.
A notícia do mês, ou melhor, do ano é a publicação do "Compromisso com a Ciência" pelo Ministério... more A notícia do mês, ou melhor, do ano é a publicação do "Compromisso com a Ciência" pelo Ministério da Ciência, ? e Tecnologia. O documento aporta um conjunto de intenções que a serem concretizadas vão de facto mudar a face da investigação científica em Portugal.
This paper presents a Learning Factory platform that is based on exploration of the freeware coll... more This paper presents a Learning Factory platform that is based on exploration of the freeware collaborative tools to address the education on advanced networked and service-based manufacturing systems such as social network-based manufacturing system. The paper presents (1) an architecture of learning factory with embedded freeware collaborative tools simulating the advanced networked and service-based manufacturing systems and organizations, and (2) elements of an application for manufacturing engineering course. The freeware-based Learning Factory platform, or environment, is oriented towards both internal and external learning and training, and for both communities, academe and industry and, especially, through their partnership. Also, the special feature of the platform is its “low-cost” allowing learning and training on advanced networked and service-based manufacturing systems in investment extensive regions and environment.
2005 European Conference on Power Electronics and Applications, 2005
This paper describes the methods used by the teaching group of power electronics and electrical d... more This paper describes the methods used by the teaching group of power electronics and electrical drives of Electrical Engineering and Automation Department of Instituto Superior de Engenharia de Lisboa (Portugal) to increase the effectiveness of experimental training in the areas of industrial electronics and electric drives. It is well known that the interest of new students for electrical engineering courses
New trends for innovation in the Mediterranean animal production, 2012
ABSTRACT In the north-west of Spain, on a marginal mountain area located at 850-950 m.a.s.l. and ... more ABSTRACT In the north-west of Spain, on a marginal mountain area located at 850-950 m.a.s.l. and dominated by heather species (Erica umbellata, Erica cinerea, Calluna vulgaris), non-lactating goats, ewes, cows and mares were managed for spring-summer grazing during two years (2006-2007). The objective was to study diet selection and live-weight (LW) changes in these animal species. The results show differences in the diet components and in the individual LW changes between these herbivores. Horse was the animal species with higher ability to modify the diet composition according to the changes in vegetation, while cattle and goats only showed minor changes. In both years, cows lost weight in any period of the grazing season, at an average of 0.48 kg/day. However, mares increased LW during the first period (June-July) and lost in the second (August-September), maintaining LW (0.04 kg/day) for the overall grazing season. There were also some differences between the small ruminants. Both sheep and goats increased their LW during the first period, although goats did it at a higher degree. By contrast, in the summer both species lost weight, though the losses tend to be higher in ewes. Thus, in the overall spring-summer grazing, goats were able to increase their LW at 10 g/day while sheep lost 10 g/day (P<0.01). Therefore, areas with improved pasture are necessary for productive animals to maintain or increase their LW, to extend the grazing season, and to achieve the sustainability. The demand for this improved pasture is considerably higher in cattle than in the other species.
Forages and grazing in horse nutrition, 2012
ABSTRACT In heath-dominated mountains of northern Spain, horse presence for foal meat production ... more ABSTRACT In heath-dominated mountains of northern Spain, horse presence for foal meat production is increasing. The objective of this study was to compare the productive responses of horses grazing on different types of heath-related shrublands, and to assess the changes in vegetation produced by horse intensive grazing. The study was carried out in a mountain area of western Asturias (Spain). Horse performance and grazing effects at a stocking rate of 3.3 mares/ha were studied in three types of heath vegetation: dominated by heather species (Erica-Calluna), dominated by gorse (Ulex gallii), and co-dominated by grasses and gorse. Two crossbred mares with their foals were managed per plot (6 plots of 0.6 ha) during the autumn of 2008, and two non-lactating mares per plot (12 plots of 0.6 ha) during the spring-summer of 2009. Animals were monthly weighed, and plant cover and height were measured. Differences in daily body weight (BW) changes among types of shrubland were analysed using ANOVA, while vegetation data were subjected to mixed model procedures for repeated measures. Mares grazing on gorse and grass-gorse shrublands achieved more favourable BW changes than those grazing on heather-dominated ones in both years. In 2008, foals also obtained higher BW gains in gorse and grass-gorse shrublands. Changes in botanical composition showed a trend for decreasing gorse cover, while heather cover was maintained, indicating a preferential browsing on gorse. Although horses are known to select intensively grasses, herbaceous cover slightly increased as gorse canopy was opening. In conclusion, gorse-dominated shrublands are more beneficial for horse nutrition than heather-dominated ones, as indicated by the better productive responses of both lactating and non-lactating mares in the former ones. Horses could be used to reduce gorse dominance, favouring the spread of heather plants, and preserving a more typical botanical composition in heathlands in the long term.
Forages and grazing in horse nutrition, 2012
ABSTRACT Heathlands are widespread in the north of the Iberian Peninsula and are usually used by ... more ABSTRACT Heathlands are widespread in the north of the Iberian Peninsula and are usually used by feral horses. Knowledge on foraging behaviour of equines in these areas is important for their efficient utilization. In this study, grazing time (GT), diet selection (DS), feed intake (FI) and digestibility (DMD), of five mares grazing on heathlands with an area of improved pasture (IP, ryegrass-white clover) was measured in June and September. Animals’ GT on each vegetation type was determined by recording their activity every 15 minutes from dawn to dusk during two consecutive days. DS, FI and DMD were estimated using n-alkane markers. IP availability was assessed by recording sward surface height. Effect of grazing season on DS, FI and DMD was examined by ANOVA. Equines showed an average daily GT of 621 min/day, with no differences between seasons, despite the shorter observation period in September. In June, mares spent most of their GT on the IP (0.847) whereas in September they spent more time on heather-gorse communities (0.516). DS results showed an almost total selection of herbs (0.971) in June, decreasing (P<0.001) its proportion to 0.823 in September in response to the decrease in IP availability (9.6 to 4.0 cm). Higher participation of woody species in September diet resulted in lower (P<0.001) DMD (368 vs. 685 g/kg DM) due to its higher fibre content. Daily FI was higher (P<0.001) in June than in September (233 vs. 119 g DM/kg LW0.75). Data obtained in this study showed that equines primarily select herbaceous plants, but they are also able to modify their foraging behaviour in response to modifications in the availability of these more nutritional feed resources.
Urban Management, Engineering, and Design, 2010
This paper reviews the main development of approaches to modelling urban public transit users' ro... more This paper reviews the main development of approaches to modelling urban public transit users' route choice behaviour from 1960s to the present. The approaches reviewed include the early heuristic studies on finding the least cost transit route and all-or-nothing transit assignment, the bus common line problem and corresponding network representation methods, the disaggregate discrete choice models which are based on random utility maximization assumptions, the deterministic use equilibrium and stochastic user equilibrium transit assignment models, and the recent dynamic transit assignment models using either frequency or schedule based network formulation.
One of the main constraints hindering the increase of animal production in semi-arid regions of A... more One of the main constraints hindering the increase of animal production in semi-arid regions of Africa is the inadequate supply of nutrients during the dry season. Incorporation of alternative feed resources in ruminant diets during this period could be a viable approach to overcome these limitations. The objective of this study was to evaluate the nutritive value of muiumba (Baikiaea plurijuga) tree seeds as an alternative nutrient source for ruminants. Muiumba seeds were compared to other eight feedstuffs including two cereal grains (corn and oat), two wheat by-products (wheat bran and distilled wheat) and four protein meals (coconut meal, sunflower meal, soybean meal and rapeseed meal) as to its chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production. The moderate crude protein concentrations (145 g/kg DM) of muiumba seeds indicate that this feedstuff could not be used as a protein supplement, contrarily to the majority of multipurpose tree seeds. Although the starch content was scarce (15 g/kg DM), the low neutral detergent fibre (235 g/kg DM), low molecular weight sugar (76.1 g/kg DM) and non-starch polysaccharide (510.5 g/kg DM) contents indicate that this feedstuff has potential feeding value. This was confirmed by the IVOMD (0.770) and by the data provided by the in vitro gas production showing that muiumba seeds had high (P < 0.05) maximum gas production and fractional fermentation rates, suggesting that these seeds are characterized by a highly fermentable fraction.
Journal of the Chemical Society, Faraday Transactions, 1992
Ah&r&-Prompt fluorescence as well as delayed fluorescence emission of acridine orange was detecte... more Ah&r&-Prompt fluorescence as well as delayed fluorescence emission of acridine orange was detected at room temperature from samples where this dye is adsorbed on microcrystalline ceIIulose. Ground state absorption studies provided evidence for dimer formation of the dye when adsorbed on cellulose, and the equilibrium constant for dimerisation was determined as 1.6fO.l X ldmol-' g. At low loadings of acridine orange on cellulose (<l pm01 g-') the fluorescence emission is mainly due to the monomer and is similar to that observed in ethanolic solutions where little aggregation occurs, and peaks at 530 nm. A linear dependence of the fluorescence intensity on the amount of light absorbed by the dye was established for these "diluted" samples. However, at higher loadings (>20 umol g-i), the fluorescence intensity decreases, and the emission is broad with its maximum at 620 nm, and is mainly due to the dimer. By assuming that the excited monomer and dimer of acridine orange are the only emitting species, it was possible to determine the fluorescence quantum yields for these two species when adsorbed on microcrystalline cellulose as 0.95 f0.05 and 0.4O+O.10, respectively. Pulsed emission studies at room temperature in the millisecond time-range also revealed monomer and dimer emissions on this longer time-scale. These are shown to be due to thermally activated delayed fluorescence arising from the triplet states of monomer and dimer acridine orange as confirmed by diffuse reflectance transient absorption studies.
E-business (B2B and B2C) is expected to dramatically change the way business is conducted. Assess... more E-business (B2B and B2C) is expected to dramatically change the way business is conducted. Assessment of the likely impact of e-business on the transport system, and hence on the natural and built environment, is thus needed. This paper reports some early findings from a study to consider e-business trends and design a procedure for rating and ranking transport impacts of
This paper describes the findings of a state-of-the-art literature review on the energy consumpti... more This paper describes the findings of a state-of-the-art literature review on the energy consumption of land based freight transport modes and outlines the development of a model to compare corridor energy consumption of road and rail options. The key parameters influencing the energy estimation and comparison procedure are identified and a methodology to compare door to door freight movement is
Lecture Notes in Computer Science, 2004
The use of grid computing technology is being boosted in last years by the growing demand of low ... more The use of grid computing technology is being boosted in last years by the growing demand of low cost computing resources and idle computing capacity in collaborative research and development environments. GridBR is a PETROBRAS project done with the collaboration of COPPE/UFRJ and IBM Brazil partnership. This project aims at grid computing technology in the information technology strategy of PETRO-BRAS Research and Development Center (CENPES). The present environment comprises a heterogeneous mix of architectures and operating systems with AIX IBM and Linux workstations providing the required support for collaborative execution of applications. The results of a genetic algorithm optimization application are presented as an example of how to take advantage of the existing grid computing infrastructure at PETROBRAS.
The aim of this paper is to present a cloudlet architecture for dashboard in Cloud and Ubiquitous... more The aim of this paper is to present a cloudlet architecture for dashboard in Cloud and Ubiquitous Manufacturing. In practice means that, with Cloud Computing adoption, Manufacturing requires management applications where ubiquity and effectiveness are enabled. If ubiquity and resources scalability, availability and capacity can be well supported by cloud, pragmatics instruments are required to support effectiveness. The architecture here presented shows the integration of enriched existing (cloud) services, as instances of resources, with layers of new services towards direct and synchronous communication between users. These Rich Internet Application (RIA) components, here named cloudlets, integration, follow dashboards organization patterns and will be supported by emergent web3.0 interaction technologies. In fact, the paper proposes a new Presentation Layer to be used in UMS and (that may be used) in any multi-layer cloud-based web application.
The main objective of this study was to validate the use of long-chain fatty acids (LCFA) as mark... more The main objective of this study was to validate the use of long-chain fatty acids (LCFA) as markers to estimate diet composition of equines fed with diets composed of herbaceous and woody species. Six crossbreed mares (434±59 kg LW) were divided in 2 groups and each group was fed one of two different diets: D1 100% Lolium perenne, D2 70% L. perenne + 30% heather (Erica spp., Calluna vulgaris). Diet composition was estimated from LCFA concentrations (C22 to C34) in diet and faeces, with (i.e. mean recovery rate of the dietary treatment that the animal belonged to) or without correction for incomplete faecal recoveries using least-squares procedures. Reulsts showed clear differences in the LCFA profiles among diet components. LCFA faecal recovery was in general incomplete and tended to decrease with carbon chain length in a curvilinear fashion (P<0.001) and was affected by diet composition (P<0.001). Results also showed that diet composition was accurately estimated with or wit...
To compare the performance and parasitic status of non-lactating goats during summer-autumn grazi... more To compare the performance and parasitic status of non-lactating goats during summer-autumn grazing (after weaning their kids) on three common vegetation types in NW Iberian Peninsula: perennial ryegrass-white clover improved pastures, heather-dominated shrublands, and gorse-dominated shrublands.
The mountainous less-favored areas of the northwest of the Iberian Peninsula are mostly covered w... more The mountainous less-favored areas of the northwest of the Iberian Peninsula are mostly covered with heathland vegetation, offering little opportunities for the development of profitable productive systems in the interests of rural people. The low nutritive value of heathlands and their high susceptibility to wildfires causes serious problems to livestock management and biodiversity conservation. The SERIDA research team on Animal Production Systems has carried out several studies in Cantabrian heathlands during the last twenty years, aiming to develop sustainable grazing systems maintaining, simultaneously, high levels of biodiversity. Research has been focused on the assessment of the nutritive quality of heathland vegetation and its potential for livestock feeding, the grazing behavior and performance of different domestic herbivore species, the establishment of improved pastures on heathland areas to get the sustainability of productive grazing systems, animal health looking at ...
To evaluate the effects of heather supplementation on diet selection, nutrient intake, and gastro... more To evaluate the effects of heather supplementation on diet selection, nutrient intake, and gastrointestinal nematode infections in goats grazing on mountain grasslands. Do goats select to feed on heather to improve their health status?
Neste trabalho apresenta-se um caso particular de "a água como recurso estruturante do desenvolvi... more Neste trabalho apresenta-se um caso particular de "a água como recurso estruturante do desenvolvimento" de uma região que desde há muitos longos anos tem influenciado o "destino" das populações, inclusivé da expansão urbana da região de Lafões e em particular de S. Pedro do Sul.
A notícia do mês, ou melhor, do ano é a publicação do "Compromisso com a Ciência" pelo Ministério... more A notícia do mês, ou melhor, do ano é a publicação do "Compromisso com a Ciência" pelo Ministério da Ciência, ? e Tecnologia. O documento aporta um conjunto de intenções que a serem concretizadas vão de facto mudar a face da investigação científica em Portugal.
This paper presents a Learning Factory platform that is based on exploration of the freeware coll... more This paper presents a Learning Factory platform that is based on exploration of the freeware collaborative tools to address the education on advanced networked and service-based manufacturing systems such as social network-based manufacturing system. The paper presents (1) an architecture of learning factory with embedded freeware collaborative tools simulating the advanced networked and service-based manufacturing systems and organizations, and (2) elements of an application for manufacturing engineering course. The freeware-based Learning Factory platform, or environment, is oriented towards both internal and external learning and training, and for both communities, academe and industry and, especially, through their partnership. Also, the special feature of the platform is its “low-cost” allowing learning and training on advanced networked and service-based manufacturing systems in investment extensive regions and environment.
2005 European Conference on Power Electronics and Applications, 2005
This paper describes the methods used by the teaching group of power electronics and electrical d... more This paper describes the methods used by the teaching group of power electronics and electrical drives of Electrical Engineering and Automation Department of Instituto Superior de Engenharia de Lisboa (Portugal) to increase the effectiveness of experimental training in the areas of industrial electronics and electric drives. It is well known that the interest of new students for electrical engineering courses
New trends for innovation in the Mediterranean animal production, 2012
ABSTRACT In the north-west of Spain, on a marginal mountain area located at 850-950 m.a.s.l. and ... more ABSTRACT In the north-west of Spain, on a marginal mountain area located at 850-950 m.a.s.l. and dominated by heather species (Erica umbellata, Erica cinerea, Calluna vulgaris), non-lactating goats, ewes, cows and mares were managed for spring-summer grazing during two years (2006-2007). The objective was to study diet selection and live-weight (LW) changes in these animal species. The results show differences in the diet components and in the individual LW changes between these herbivores. Horse was the animal species with higher ability to modify the diet composition according to the changes in vegetation, while cattle and goats only showed minor changes. In both years, cows lost weight in any period of the grazing season, at an average of 0.48 kg/day. However, mares increased LW during the first period (June-July) and lost in the second (August-September), maintaining LW (0.04 kg/day) for the overall grazing season. There were also some differences between the small ruminants. Both sheep and goats increased their LW during the first period, although goats did it at a higher degree. By contrast, in the summer both species lost weight, though the losses tend to be higher in ewes. Thus, in the overall spring-summer grazing, goats were able to increase their LW at 10 g/day while sheep lost 10 g/day (P<0.01). Therefore, areas with improved pasture are necessary for productive animals to maintain or increase their LW, to extend the grazing season, and to achieve the sustainability. The demand for this improved pasture is considerably higher in cattle than in the other species.
Forages and grazing in horse nutrition, 2012
ABSTRACT In heath-dominated mountains of northern Spain, horse presence for foal meat production ... more ABSTRACT In heath-dominated mountains of northern Spain, horse presence for foal meat production is increasing. The objective of this study was to compare the productive responses of horses grazing on different types of heath-related shrublands, and to assess the changes in vegetation produced by horse intensive grazing. The study was carried out in a mountain area of western Asturias (Spain). Horse performance and grazing effects at a stocking rate of 3.3 mares/ha were studied in three types of heath vegetation: dominated by heather species (Erica-Calluna), dominated by gorse (Ulex gallii), and co-dominated by grasses and gorse. Two crossbred mares with their foals were managed per plot (6 plots of 0.6 ha) during the autumn of 2008, and two non-lactating mares per plot (12 plots of 0.6 ha) during the spring-summer of 2009. Animals were monthly weighed, and plant cover and height were measured. Differences in daily body weight (BW) changes among types of shrubland were analysed using ANOVA, while vegetation data were subjected to mixed model procedures for repeated measures. Mares grazing on gorse and grass-gorse shrublands achieved more favourable BW changes than those grazing on heather-dominated ones in both years. In 2008, foals also obtained higher BW gains in gorse and grass-gorse shrublands. Changes in botanical composition showed a trend for decreasing gorse cover, while heather cover was maintained, indicating a preferential browsing on gorse. Although horses are known to select intensively grasses, herbaceous cover slightly increased as gorse canopy was opening. In conclusion, gorse-dominated shrublands are more beneficial for horse nutrition than heather-dominated ones, as indicated by the better productive responses of both lactating and non-lactating mares in the former ones. Horses could be used to reduce gorse dominance, favouring the spread of heather plants, and preserving a more typical botanical composition in heathlands in the long term.
Forages and grazing in horse nutrition, 2012
ABSTRACT Heathlands are widespread in the north of the Iberian Peninsula and are usually used by ... more ABSTRACT Heathlands are widespread in the north of the Iberian Peninsula and are usually used by feral horses. Knowledge on foraging behaviour of equines in these areas is important for their efficient utilization. In this study, grazing time (GT), diet selection (DS), feed intake (FI) and digestibility (DMD), of five mares grazing on heathlands with an area of improved pasture (IP, ryegrass-white clover) was measured in June and September. Animals’ GT on each vegetation type was determined by recording their activity every 15 minutes from dawn to dusk during two consecutive days. DS, FI and DMD were estimated using n-alkane markers. IP availability was assessed by recording sward surface height. Effect of grazing season on DS, FI and DMD was examined by ANOVA. Equines showed an average daily GT of 621 min/day, with no differences between seasons, despite the shorter observation period in September. In June, mares spent most of their GT on the IP (0.847) whereas in September they spent more time on heather-gorse communities (0.516). DS results showed an almost total selection of herbs (0.971) in June, decreasing (P<0.001) its proportion to 0.823 in September in response to the decrease in IP availability (9.6 to 4.0 cm). Higher participation of woody species in September diet resulted in lower (P<0.001) DMD (368 vs. 685 g/kg DM) due to its higher fibre content. Daily FI was higher (P<0.001) in June than in September (233 vs. 119 g DM/kg LW0.75). Data obtained in this study showed that equines primarily select herbaceous plants, but they are also able to modify their foraging behaviour in response to modifications in the availability of these more nutritional feed resources.
Urban Management, Engineering, and Design, 2010
This paper reviews the main development of approaches to modelling urban public transit users' ro... more This paper reviews the main development of approaches to modelling urban public transit users' route choice behaviour from 1960s to the present. The approaches reviewed include the early heuristic studies on finding the least cost transit route and all-or-nothing transit assignment, the bus common line problem and corresponding network representation methods, the disaggregate discrete choice models which are based on random utility maximization assumptions, the deterministic use equilibrium and stochastic user equilibrium transit assignment models, and the recent dynamic transit assignment models using either frequency or schedule based network formulation.
One of the main constraints hindering the increase of animal production in semi-arid regions of A... more One of the main constraints hindering the increase of animal production in semi-arid regions of Africa is the inadequate supply of nutrients during the dry season. Incorporation of alternative feed resources in ruminant diets during this period could be a viable approach to overcome these limitations. The objective of this study was to evaluate the nutritive value of muiumba (Baikiaea plurijuga) tree seeds as an alternative nutrient source for ruminants. Muiumba seeds were compared to other eight feedstuffs including two cereal grains (corn and oat), two wheat by-products (wheat bran and distilled wheat) and four protein meals (coconut meal, sunflower meal, soybean meal and rapeseed meal) as to its chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production. The moderate crude protein concentrations (145 g/kg DM) of muiumba seeds indicate that this feedstuff could not be used as a protein supplement, contrarily to the majority of multipurpose tree seeds. Although the starch content was scarce (15 g/kg DM), the low neutral detergent fibre (235 g/kg DM), low molecular weight sugar (76.1 g/kg DM) and non-starch polysaccharide (510.5 g/kg DM) contents indicate that this feedstuff has potential feeding value. This was confirmed by the IVOMD (0.770) and by the data provided by the in vitro gas production showing that muiumba seeds had high (P < 0.05) maximum gas production and fractional fermentation rates, suggesting that these seeds are characterized by a highly fermentable fraction.
Journal of the Chemical Society, Faraday Transactions, 1992
Ah&r&-Prompt fluorescence as well as delayed fluorescence emission of acridine orange was detecte... more Ah&r&-Prompt fluorescence as well as delayed fluorescence emission of acridine orange was detected at room temperature from samples where this dye is adsorbed on microcrystalline ceIIulose. Ground state absorption studies provided evidence for dimer formation of the dye when adsorbed on cellulose, and the equilibrium constant for dimerisation was determined as 1.6fO.l X ldmol-' g. At low loadings of acridine orange on cellulose (<l pm01 g-') the fluorescence emission is mainly due to the monomer and is similar to that observed in ethanolic solutions where little aggregation occurs, and peaks at 530 nm. A linear dependence of the fluorescence intensity on the amount of light absorbed by the dye was established for these "diluted" samples. However, at higher loadings (>20 umol g-i), the fluorescence intensity decreases, and the emission is broad with its maximum at 620 nm, and is mainly due to the dimer. By assuming that the excited monomer and dimer of acridine orange are the only emitting species, it was possible to determine the fluorescence quantum yields for these two species when adsorbed on microcrystalline cellulose as 0.95 f0.05 and 0.4O+O.10, respectively. Pulsed emission studies at room temperature in the millisecond time-range also revealed monomer and dimer emissions on this longer time-scale. These are shown to be due to thermally activated delayed fluorescence arising from the triplet states of monomer and dimer acridine orange as confirmed by diffuse reflectance transient absorption studies.