Search results for "Uniformity"
showing 9 items of 9 documents
Centre-pivot irrigation system design for uniform water application rate
2020
<p>In the last few decades, the use of centre-pivot irrigation systems has significantly increased, since it makes farming easier, is more efficient and less time-consuming compared to the other irrigation systems. Several studies have been focused on the hydraulics of the centre-pivot systems. Standard high-pressure impact sprinklers or low-pressure spray sprinklers or Low Energy Precision Application (LEPA) systems are generally mounted on the pipeline.</p><p>To ensure the uniformity of water application, the centre-pivot design requires increasing the flow rates along the lateral, because the sprinklers farther from the pivot move faster, and th…
Le relazioni fra lo Stato e le Regioni nella gestione della pandemia da Covid-19 tra uniformità e differenziazione
2021
The paper analyze the relations between the State and the regions in the management of the Covid-19 pandemic, both in terms of sources and procedures, as governed by the regulatory and administrative measures adopted by the Government, moving in the direction of uniformity and regional differentiation.
First-order expressibility of languages with neutral letters or: The Crane Beach conjecture
2005
A language L over an alphabet A is said to have a neutral letter if there is a letter [email protected]?A such that inserting or deleting e's from any word in A^* does not change its membership or non-membership in L. The presence of a neutral letter affects the definability of a language in first-order logic. It was conjectured that it renders all numerical predicates apart from the order predicate useless, i.e., that if a language L with a neutral letter is not definable in first-order logic with linear order, then it is not definable in first-order logic with any set N of numerical predicates. Named after the location of its first, flawed, proof this conjecture is called the Crane Beach …
An Analytical Tire Model with Flexible Carcass for Combined Slips
2014
Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2014/397538 The tire mechanical characteristics under combined cornering and braking/driving situations have significant effects on vehicle directional controls. The objective of this paper is to present an analytical tire model with flexible carcass for combined slip situations, which can describe tire behavior well and can also be used for studying vehicle dynamics. The tire forces and moments come mainly from the shear stress and sliding friction at the tread-road interface. In order to describe complicated tire characteristics and tire-roa…
Hume’s Fork and Mixed Mathematics
2017
Abstract:Given the sharp distinction that follows from Hume’s Fork, the proper epistemic status of propositions of mixed mathematics seems to be a mystery. On the one hand, mathematical propositions concern the relation of ideas. They are intuitive and demonstratively certain. On the other hand, propositions of mixed mathematics, such as in Hume’s own example, the law of conservation of momentum, are also matter of fact propositions. They concern causal relations between species of objects, and, in this sense, they are not intuitive or demonstratively certain, but probable or provable. In this article, I argue that the epistemic status of propositions of mixed mathematics is that of matters…
Determining Optimal Seasonal Irrigation Depth Based on Field Irrigation Uniformity and Economic Evaluations: Application for Onion Crop
2016
The crop water production function (WPF), representing the relationship between crop yield and seasonal irrigation water, is a useful tool for irrigation planning purposes. The objective of the paper is to propose a methodology to evaluate the optimal seasonal irrigation depth based on the crop production function, the field distribution uniformity, and economic considerations. An extended unpublished database experimentally obtained on the onion crop on the island of Kula, Hawaii, was initially used to assess the crop WPF. The combination between the crop WPF and the model representing the field distribution uniformity allowed determining the area subjected to underirrigation and overirrig…
Alternative nursery propagation for vineyards establishment
2016
Dead vines are often a problem present in many vineyards and are due to physiological or pathological causes whereby the vines need to be replaced. The aim of the trial was to create in the nursery plant material of four cultivars in order to easily replace the dead vines in the vineyards but also to anticipate the first harvest and to improve the vineyard uniformity and synchronize the vineyard management practices during the first two years of plantation. During the first year in the nursery, the effect of plant density on the percentage of success and vegetative growth was evaluated. During the second year, in the open field and only for one cultivar, the vegetative and reproductive para…
Vegetative and reproductive parameters evaluation of alternative plant material
2013
Dead vines are often a problem in many vineyards and are due to physiological or pathological causes whereby the vines need to be replaced. The replacement operation is a real cost for the direct costs of the plant material, for its planting and for their different management during the current year or in the two years after the replacement, determining also vineyard variability. When replacement is performed in the first years after vineyard establishment it is quite easy, whereas many issues occur when replacement is later, particularly issues considering roots competition. To reduce replacement problems, the use of “alternative plant material” has been evaluated. The “alternative vines” …
Legacy Effects of Contrasting Long-Term Integrated Weed Management Systems
2022
To reduce reliance on herbicides and maintain crop productivity, integrated weed management (IWM) seeks to optimize synergies between diverse sets of weed management practices combined at the cropping system scale. Nevertheless, data on weed community response to the long-term implementation of IWM practices remain scare. Here, we assessed the effects of four IWM systems with contrasting objectives and practices (S2: transition from superficial tillage to conservation agriculture; S3: no-mechanical weeding; S4: mixed mechanical and chemical weeding; S5: herbicide-free; all with 6 year rotations) compared to a conventional reference (S1: herbicide-based with systematic plowing and a 3 year r…