3,901 research outputs found

    A Comparison of Assistive Methods for Suturing in MIRS

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    In Minimally Invasive Robotic Surgery (MIRS) a robot is interposed between the surgeon and the surgical site to increase the precision, dexterity, and to reduce surgeon's effort and cognitive load with respect to the standard laparoscopic interventions. However, the modern robotic systems for MIRS are still based on the traditional telemanipulation paradigm, e.g. the robot behaviour is fully under surgeon's control, and no autonomy or assistance is implemented. In this work, supervised and shared controllers have been developed in a vision-free, human-in-the-Ioop, control framework to help surgeon during a surgical suturing procedure. Experiments conducted on the da Vinci Research Kit robot proves the effectiveness of the method indicating also the guidelines for improving results

    Design of a Base-Board for arrays of closely-packed Multi-Anode Photo-Multipliers

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    We describe the design of a Base-Board to house Multi-Anode Photo-Multipliers for use in large-area arrays of light sensors. The goals, the design, the results of tests on the prototypes and future developments are presented.Comment: 16 pages, 5 figures, submitted to Nucl. Instrum. and Meth.

    VEGETATION LANDSCAPE MANAGEMENT OF “NATURAL RESERVE OF CHIARONE”, MASSACIUCCOLI LAKE BASIN (TUSCANY, IT)

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    The Massaciuccoli Lake is located in NW of Tuscany (Italy) (43°50’N 10°19’E) and it is integral part of the Regional Park of San Rossore, Migliarino and Massaciuccoli. This endorheic lake and the surrounding marshlands, with over 2,000 hectares of surface, form the largest retrodunal wetland of Tuscany. Over the last century this ecological system has undergone profound changes both because of land drainage, both because of the industrial and agricultural development of the surrounding areas that have heavily polluted lake, whose waters are still affected by serious eutrophication and ecological degradation. In order to preserve the great natural value of the lake in 1979, with the birth of the regional protected area, was established in the marshy area around the village of Massaciuccoli, the "Natural Reserve of Chiarone"(100 ha). Since 1985 the association LIPU (Italian League for Bird Protection) has obtained the management of the reserve, and its activity is directed to purposes of environmental education, environmental restoration, monitoring and conservation of specific habitats. This report shows the results of several years of investigation on the main vegetational types and their diachronic tranformations, the presence and distribution of endemic/rare/protected species, the changes on the structure of floating islands of peats and the main actions of conservation and management of these wetlands. The vegetation landscape is mainly formed by a mosaic of Phragmitetum australis Gams 1927, Cladietum marisci (Allorge 1922) Zobrist 1935, Typhetum angustifoliae Pignatti 1953, Myriophyllo-Nupharetum Koch 1926, and a large spread of microwoods of hygrophilous phanerophytes as Alnus glutinosa, Frangula alnus, Salix sp.pl. A particular aspect of this lake environment are the "aggallati", floating islands of peat incurred by intertwining rhizomes of straws. Above these peatlands often develop communities of Sphagnum sp.pl, Osmunda regalis L. and Thelypteris palustris Schott (Fig.1). The monitoring of these environments has highlighted the importance of ongoing management, in relation to the maintenance of certain habitats, through periodic cuttings, such as Sphagnum bogs, the control of exotic fauna such as Myocastor coypus, particularly damaging for Cladietum meadows and the special maintenance of the islands, whose structural peculiarity has lately been severely damaged catastrophic weather event

    The influence of non-living mulch, mechanical and thermal treatments on weed population and yield of rainfed fresh-market tomato (Solanum lycopersicum L.)

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    Weed control is often a major limitation for vegetable crops, since compared to arable crops fewer herbicides are available and the crops are more sensitive to weeds. Field experiments were carried out in the province of Pisa (Central Italy) to determine the effect of two different mulches (black biodegradable plastic film and wheat straw) and mechanical and thermal treatments on weed population and yield of rain-fed fresh market tomato (Solanum lycopersicum L.). Rolling harrow, flaming machine and precision hoe for weed control, which were either built, enhanced or modified by the University of Pisa were used separately (mechanical-thermal strategy) or in combination with a straw mulch (mechanical-thermal-straw strategy). These two innovative strategies were compared with the traditional farming system, which uses a biodegradable plastic mulch film. The strategies were compared in terms of machine performance, weed density, total labour requirement, weed dry biomass, and crop fresh yield at harvest. The total operative time for weed control was on average ~25 h ha-1 for the two systems, which included mulching, and over 30 h ha-1 for the mechanical-thermal strategy. The three strategies controlled weeds effectively, with only 30 g m-2 in each treatment. Tomato yield, however, was 35% higher for strategies that included mulching (both biodegradable film and straw)

    Hot foam and hot water for weed control: a comparison

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    Thermal weed control plays an important role in managing weeds in synthetic herbicide-free systems, particularly in organic agriculture and in urban areas where synthetic herbicides are prohibited. This study compares the impact on weed control of increased doses of hot water and hot foam (i.e. 0, 0.67, 1.67, 3.33, 5.00, 6.67 and 8.33 kg m–2). The doses were applied using the same machine. The temperatures, weed control effectiveness, weed regrowth after the death of the aboveground vegetative weed tissues, and weed dry biomass 30 days after the treatments were studied in two experimental fields with a different weed composition (i.e. Site I and Site II). The results showed that difficult weeds to control, such as Cynodon dactylon (L.) Pers., Digitaria sanguinalis (L.) Scop. and Taraxacum officinale Weber, like all the other species in the initial weed populations in the two experiments, died after lower doses of hot foam compared to hot water. Adding foam to hot water made it possible to lower the required dose of water by at least 2.5-fold compared to hot water used alone. By insulating the weeds, the foam led to higher peak temperatures and slower temperature decay, thus determining an effective weed control with lower doses compared to hot water. Starting from 11 days and 16 days after treatments (for Site I and Site II, respectively), there were no statistically significant differences in weed regrowth between hot foam and hot water at all the doses applied. There were no differences between the dry biomass of weeds collected 30 days after treatments when the same doses of hot foam and hot water were used

    Using flaming as an alternative method to vine suckering.

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    Suckering is the process of removing the suckers that grapevine trunks put out in the spring. Suckering by hand is costly and time consuming and requires constant bending down, getting up and making repetitive motions. The mechanical removal of suckers with rotating scourges can damage the vine plants. Chemical suckering is a limiting factor for wine grape growers interested in sustainable and/or organic agriculture. The aim of this research was to test flaming as an alternative method to vine suckering. A three-year experiment was conducted on a 10-year-old Sangiovese vine (775 Paulsen rootstock). The treatments consisted of flame suckering at different phenological stages, hand-suckering and a no-suckered control. Data on the number of suckers, grape yield components, and grape composition were collected and analysed. The results showed that flaming significantly reduced the initial number of suckers. This effect on the suckers was highest when the main productive shoots of the vines were at the 18-19 BBCH growth stage. Flame-suckering did not affect grape yield components and grape composition. Future studies could investigate the simultaneous use of flaming for both suckering and weed control

    Flaming, glyphosate, hot foam and nonanoic acid for weed control: a comparison.

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    Synthetic herbicides are commonly used in weed management, however, 70 years of use has led to weed resistance and environmental concerns. These problems have led scientists to consider alternative methods of weed management in order to reduce the inputs and impacts of synthetic herbicides. The aim of this experiment was to test the level of weed control using four weeding methods: glyphosate applied at an ultra-low volume, the organic herbicide nonanoic acid, flaming, and hot foam. The results showed that weed control was eective only when flaming and hot foam were applied (99% and 100% weed control, respectively). Nonanoic acid at a dose of 11 kg a.i. ha1 diluted in 400 L of water did not control developed plants of Cyperus esculentus (L.), Convolvulus arvensis (L.) and Poa annua (L.). Glyphosate at a dose of 1080 g a.i. ha1 (pure product) only controlled P. annua (L.), but had no eect on C. esculentus (L.) and C. arvensis (L.). After the aboveground tissues of weeds had died, regrowth began earlier after flaming compared to hot foam. There was no regrowth of P. annua (L.) only after using hot foam and glyphosate. Hot foam was generally better at damaging the meristems of the weeds. In one of the two experiment sites, significantly more time was needed after the hot foam to recover 10% and 50% of the ground compared to flaming. The time needed to recover 90% of the ground was on average 26–27 days for flaming and hot foam, which is the time that is assumed to be required before repeating the application. A total of 29 days after the treatments, weeds were smaller after flaming, glyphosate and hot foam compared to nonanoic acid and the control, where they had more time to grow

    The use of different hot foam doses for weed control

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    Thermal weed control technology plays an important role in managing weeds in synthetic herbicide-free systems, particularly in organic agriculture. The use of hot foam represents an evolution of the hot water weed control thermal method, modified by the addition of biodegradable foaming agents. The aim of this study was to test the weeding eect of dierent five hot foam doses, in two sites of dierent weed composition fields [i.e., Festuca arundinacea (Schreb.), Taraxacum ocinale (Weber) and Plantago lanceolata (L.)], by evaluating the devitalisation of weeds, their regrowth, the weed dry biomass at the end of the experiment and the temperature of hot foam as aected by dierent foam doses. The results showed that the eect of the hot foam doses diered with the dierent infested weed species experiments. In the Festuca arundinacea (Schreb.) infested field, all doses from 3.33 L m2 to 8.33 L m2 led to a 100% weed cover devitalisation and a lower weed dry biomass compared to the dose of 1.67 L m2, whereas the weed regrowth was similar when all doses were applied. In the Taraxacum ocinale (Weber) and Plantago lanceolata (L.) infested fields, doses from 5.00 L m2 to 8.33 L m2 in site I and from 3.33 L m2 to 8.33 L m2 in site II led to 100% of weed cover devitalisation. The highest doses of 6.67 L m2 and 8.33 L m2 led to a slower weed regrowth and a lower weed dry biomass compared to the other doses. The time needed for weeds to again cover 50%, after the 100% devitalisation, was, on average, one month when all doses were applied in the Festuca arundinacea (Schreb.) infested field, whereas in the Taraxacum ocinale (Weber) and Plantago lanceolata (L.) fields, this delay was estimated only when doses of 6.67 L m2 and 8.33 L m2 were used in site I and a dose of 8.33 L m2 in site II. Thus, in the Festuca arundinacea (Schreb.) field experiments hot foam doses from 3.33 L m2 to 8.33 L m2 were eective in controlling weeds, and the use of the lowest dose (i.e., 3.33 L m2) is recommended. However, for Taraxacum ocinale (Weber) and Plantago lanceolata (L.) the highest doses are recommended (i.e., 6.67 L m2 and 8.33 L m2), as these led to 100% weed devitalisation, slower regrowth, and lower weed dry biomass than other doses. A delay in the regrowth of weeds by 30 days can lead to the hypothesis that the future application of hot foam as a desiccant in no-till field bands, before the transplant of high-income vegetable crops, will provide a competitive advantage against weeds

    Evolution of smart strategies and machines used for conservative management of herbaceous and horticultural crops in the mediterranean basin: a review

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    Preserving soil quality and increasing soil water availability is an important challenge to ensure food production for a growing global population. As demonstrated by several studies, conservative crop management, combined with soil cover and crop diversification, can significantly reduce soil and water losses. The aim of this review is to evaluate the spread of smart solutions to perform conservation agriculture (CA) well in the Mediterranean Basin, taking into account the evolution of the strategies and the machines used to perform conservative tillage systems in different contexts in the last 30 years, as well as the effects induced by their adoption on the productivity of herbaceous and horticultural crops, weed control and economic feasibility, in comparison with those obtained utilizing conventional techniques based on soil inversion
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