Redundant disc

A rotatable disc is described that consists of parallel plates tightly joined together for rotation about a hub. Each plate is provided with several angularly projecting spaced lands. The lands of each plate are interposed in alternating relationship between the lands of the next adjacent plate. In this manner, circumferential displacement of adjacent sectors in any one plate is prevented in the event that a crack develops. Each plate is redundantly sized so that, in event of structural failure of one plate, the remaining plates support a proportionate share of the load of the failed plate. The plates are prevented from separating laterally through the inclusion of generally radially extending splines which are inserted to interlock cooperating, circumferentially adjacent lands

Quand les tanetys rejoignent les rizières au lac Alaotra " : Diversification et innovation sur les zones exondées dans un contexte foncier de plus en plus saturé.

Le lac Alaotra reste une zone d'immigration importante malgré une population rurale qui double tous les 18 ans. Le foncier est saturé dans les zones basses irrigables (riziculture irriguée contrôlée), les rizières à mauvaise maîtrise de l'eau et les zones de " baiboho " (sols d'alluvions exondés riches, de plaine avec accès à l'eau phréatique pendant la saison sèche). L'expansion en termes de nouvelles terres à cultiver se fait donc sur les zones exondées des collines environnant la plaine du lac (les " tanety "). La diversité des sols, leur fragilité (avec des phénomènes érosifs et géologiques importants comme ceux des " lavaka " (zone d'effondrement des tanety), la déforestation massive dans les fonds de vallées et les bas de pente et l'élevage bovin extensif initialement basé sur la vaine pâture ont créé une forte diversité dans les paysages et les conditions de mise en valeur des terres. Cette large gamme de situations implique, pour les actions de développement, de proposer des techniques diversifiées et localement adaptées, notamment des systèmes de culture permettant une production régulière et durable (basée sur la réduction des risques), une protection des sols contre l'érosion et une " mise en défens " aboutissant à une renégociation des relations agriculture - élevage. Les systèmes de semis direct sur couverture végétale (" SCV "), introduits et diffusés par le projet BVLac depuis 2003, semblent prometteurs dans cette voie. Le suivi de plusieurs centaines de parcelles, encadrées par l'opérateur BRL, a permis la création d'une base de données solide reprenant les résultats réellement observés en milieu paysan. Liée à une approche " exploitation ", centrée sur la prise en compte des stratégies paysannes et des contraintes liées à l'ensemble des activités agricoles, l'exploitation de cette base de données permet de mieux appréhender les processus d'innovation locaux face à ce changement de paradigme important pour les producteurs. En effet, les techniques novatrices de l'agro-écologie impliquent l'abandon du labour et la combinaison de plantes dont certaines ne sont pas productives mais qui génèrent, au sein du système, des externalités positives. De plus, ces techniques s'accompagnent d'un certain niveau d'intensification permettant de valoriser les variétés améliorées introduites, en fonction des sols et surtout de la situation financière des exploitations. La gestion du risque et la régularité des productions dans le cadre de stratégies anti-aléatoires sont au cœur de ces processus d'innovation en cours, lesquels montrent une remarquable flexibilité dans l'adaptation et l'appropriation et induisent quelquefois la modification du comportement des paysans face à des systèmes somme toute complexes, nécessitant l'accès à de nombreux services encore embryonnaires dans la région

Modeling impact of Conservation Agriculture adoption on farming systems agricultural incomes. The case of Lake Alaotra Region, Madagascar

Conservation Agriculture (CA) was introduced at the lake Alaotra, in Madagascar, in the 2000's in a context of traditionnal mining upland agriculture and silting-up of lowlands rice fields. Land tenure pressure linked to the attractiveness of the area lead to the progressive colonization of surrounding upland hills (Tanety), very sensitive to erosion. Conservation agriculture tackles with a double challenges: i) maintain and/or increase household income and ii) preserve natural resources through sustainable agricultural practices in the long term. This paper assesses the economic impact of CA adoption on farmers's income trough modeling representative farms selected according to a local typology, based on the last 5 years with a prospective analysis for the next 5 years. The BV-lac Project Field database highlighted a light increase of yield according to the age of CA systems. A buffering effect on climate hazards has been as well identified trough production stability over the years leading to adoption as part of a risk limiting strategy. Elements of the CA techniques are adopted spontaneously within surrounding farming systems leading to improvment of conventionnal tillage based systems. Smallholders agricultural practices evolution displays a high capacity for innovation. Modeling with a dedidated tool (Olympe is a budget analysis oriented tool) has highlighted that CA systems improve significantly net farm income in the midterm (5 to 10 years) and gross margin at plot scale. For farm holdings with few irrigated rice fields, mainly relying on upland agriculture, CA systems increase farming systems resilience to climatic events and price volatility as well as sustainable agricultural practices maintaining local and fragile ressources

Rôle et place du riz pluvial dans les exploitations du lac Alaotra

International audienceLa région de l'Alaotra repose sur un plateau situé à 750 mètres d'altitude avec au cœur de la plaine le lac Alaotra. La surface cultivée en riziculture est estimée à 148 500 ha en 2000 (FAO/UPDR, 2000), dont 75-80 000 ha dans la cuvette du Lac et plus de 65-70 000 ha au sud et dans les zones en périphérie, qui constitue 10% de la surface rizicole nationale pour seulement 4% des riziculteurs malgaches. Cette région réalise 33% de la valeur ajoutée de l'ensemble de la filière nationale et 15% de la richesse générée par le secteur riz. Le climat irrégulier constitue une contrainte majeure pour tous les agriculteurs du lac Alaotra. Les relations agriculture-élevage sont au cœur de la problématique de développement et d'évolution des exploitations agricoles.Ainsi, avec la saturation des rizières irrigables ou à Mauvaise Maîtrise de l'Eau (RMME), la colonisation agricole des tanety anciennement dévolus aux pâturages extensifs depuis les années 1980 s'est accélérer, induisant la perturbation des activités d'élevage bovin traditionnel extensif à objectif de capitalisation qui évoluent aujourd'hui vers un élevage productif (embouche et production laitière) ou de trait. Le diagnostic réalisé en 2007 a mis en évidence 7 types d'exploitations agricoles différents. Les différents systèmes de riziculture pluviale se retrouvent sur les plateaux sommitaux et les pentes des collines (en rotation jachère culture sur les sols très pauvres), les bas de pente et les baiboho, en rotation avec d'autres cultures pluviales (maïs, manioc, pois de terre...) avec ou sans jachère, ou en système SCV depuis leur introduction au début des années 2000. L'introduction de variétés composites poly-aptitudes de type Sebota a pu lever une contrainte majeure des zones ni totalement irriguées ni totalement pluviales mais intermédiaires dans les RMME (riziculture pluviale partiellement irriguée, selon l'accès à l'eau et les caractéristiques climatiques de la saison), Les systèmes SCV mis au point sur baiboho avec des successions culturales de type riz de saison / haricot de contre saison - maïs de saison ou riz de saison puis vesce de contre saison associée ou non à des cultures maraîchères montrent également un niveau de production et de sécurité par rapport aux aléas climatiques très proche voire supérieurs à ceux obtenus en riziculture irriguée. La part du riz pluvial dans la formation du revenu et la sécurité alimentaire a été analysée pour chaque type d'exploitation et varie de 20 à 30 % du revenu riz total (avant autoconsommation), et se révèle croissante en fonction du rapport tanety / rizière dans l'exploitation. Ainsi, sur certaines zones, le riz pluvial semble avoir de beaux jours devant lui. Mots clés : Riz pluvial, exploitation agricoles, lac Alaotra, SCV, riz poly-aptitudes

Pengaruh Sebaran Fasilitas Pendidikan Dasar Hingga Menengah Pertama Terhadap Sistem Zonasi Di Kecamatan Serengan Tahun 2021

Zoning is the division or splitting of an area into several parts, in accordance with the functions and management objectives (Big Indonesian Dictionary). All zoning systems – especially public schools – are prepared to provide quality education services equally to members of the community in a certain area or area so that the “best children” do not have to look for the “best schools” which are located far from where they live. This research was conducted in the Serengan District of Surakarta City by taking two main problem formulations, namely (1) the distribution of public elementary school education facilities to junior high schools in Serengan District in 2021 and (2) the linkage of the distribution of public elementary school level education facilities to secondary schools of the junior to the zoning system in Serengan District in 2021. The objectives of this study are (1) to analyze the distribution of basic to junior high school education facilities in Serengan District in 2021 and (2) to analyze the relationship between the distribution of basic to junior high school education facilities. on the implementation of the zoning system in Serengan District in 2021. This study uses a field survey method because the number of samples is so small that it is required to make all educational facilities at each level the population in this study. Then, a spatial approach is carried out by showing the level of distribution with the analysis, namely the administrative area. The data collection method used is the method of documentation and field observation, while the data processing technique used is GIS analysis using Nearest-neighbour analysis and analyzing the impact of factors that will affect the distribution and assembly of the zoning system. The results of this study are as follows: (1) the pattern of distribution of educational facilities at each level from elementary school to junior high school shows a clustered pattern, this is presented in maps 5 and 6 and is further strengthened by the results of the calculation of the closest analysis to obtain the distance between school buildings. at each level of education is 0.90 km. where the distance of 0.90 km is a reference for the clustering pattern. (2) the linkage of the distribution of state basic to high school education facilities to the implementation of the zoning system in Serengan District does not have much of a connection or influence. However, in this case the Serengan District or the Education Office or the authorities in the world of Education are required to be able to increase the number of educational facilities for junior high school. This is because the number of state junior high school facilities is only 2 schools, where this number can be categorized as low because it cannot meet the needs of the population aged 12-15 years in each yea

On the Generalizability of Experimental Results

The age-old question of the generalizability of the results of experiments that are conducted in artificial laboratory settings to more realistic inferential and decision making situations is considered in this paper. Conservatism in probability revision provides an example of a result that 1) has received wide attention, including attention in terms of implications for real-world decision making, on the basis of experiments conducted in artificial settings and 2) is now apparently thought by many to be highly situational and not at all a ubiquitous phenomenon, in which case its implications for real-world decision making are not as extensive as originally claimed. In this paper we consider the questions of generalizations from the laboratory to the real world in some detail, both within the context of the experiments regarding conservatism and within a more general context. In addition, we discuss some of the difficulties inherent in experimentation in realistic settings, suggest possible procedures for avoiding or at least alleviating such difficulties, and make a plea for more realistic experiments

EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats

Aim: The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation‐plot records to the habitats of the EUNIS system, use it to classify a European vegetation‐plot database, and compile statistically‐derived characteristic species combinations and distribution maps for these habitats. Location: Europe. Methods: We developed the classification expert system EUNIS‐ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and set‐theoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating species‐to‐habitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat. Results: Formal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 man‐made habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination. Conclusions: EUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNIS‐ESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Global maps of soil temperature

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km² resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e., offset) between in-situ soil temperature measurements, based on time series from over 1200 1-km² pixels (summarized from 8500 unique temperature sensors) across all the world’s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

Global maps of soil temperature.

Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications