1,141 research outputs found

    CURRENT STATE CONCERNING THE CONSTRUCTION OF ORGANIC COMPOST EQUIPMENT. A REVIEW

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    Globally, in recent years, attempts have been made to move towards organic farming by eliminating the use of synthetic fertilizers and pesticides. To increase soil fertility, more and more natural, biodegradable fertilizers are used. Composting is a naturally controlled process, in which beneficial microorganisms, bacteria, and fungi, turn waste into a finite, fertilizer and soil hardener, which can be considered the enemy of soil pathogens. By decomposing and stabilizing organic substances during fermentation under the action of microorganisms, by biological degradation, the organic material is transformed into a humus-like material. The main purpose of waste composting technologies is to reduce the amount of biodegradable waste, to store it in environmentally friendly conditions and, finally, to reintroduce the finished product, which is compost, into the economic circuit.This paper aims to present the current state concerning the construction of organic compost equipment, but also the advantages and disadvantages of each equipment /machinery.

    Subcentimeter depth resolution using a single-photon counting time-of-flight laser ranging system at 1550 nm wavelength

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    We demonstrate subcentimeter depth profiling at a stand off distance of 330m using a time-of-flight approach based on time-correlated single-photon counting. For the first time to our knowledge, the photon-counting time-of-flight technique was demonstrated at a wavelength of 1550nm using a superconducting nanowire single-photon detector. The performance achieved suggests that a system using superconducting detectors has the potential for low-light-level and eye-safe operation. The system’s instrumental response was 70ps full width at half-maximum, which meant that 1cm surface-to-surface resolution could be achieved by locating the centroids of each return signal. A depth resolution of 4mm was achieved by employing an optimized signal-processing algorithm based on a reversible jump Markov chain Monte Carlo method

    Infinite-dimensional representations of the rotation group and Dirac's monopole problem

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    Within the context of infinite-dimensional representations of the rotation group the Dirac monopole problem is studied in details. Irreducible infinite-dimensional representations, being realized in the indefinite metric Hilbert space, are given by linear unbounded operators in infinite-dimensional topological spaces, supplied with a weak topology and associated weak convergence. We argue that an arbitrary magnetic charge is allowed, and the Dirac quantization condition can be replaced by a generalized quantization rule yielding a new quantum number, the so-called topological spin, which is related to the weight of the Dirac string.Comment: JHEP style. Extended version of hep-th/0403146. Revised version, title and some notations are changed. References and Appendix B are adde

    A systematic aspect-oriented refactoring and testing strategy, and its application to JHotDraw.

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    Aspect oriented programming aims at achieving better modularization for a system's crosscutting concerns in order to improve its key quality attributes, such as evolvability and reusability. Consequently, the adoption of aspect-oriented techniques in existing (legacy) software systems is of interest to remediate software aging. The refactoring of existing systems to employ aspect-orientation will be considerably eased by a systematic approach that will ensure a safe and consistent migration. In this paper, we propose a refactoring and testing strategy that supports such an approach and consider issues of behavior conservation and (incremental) integration of the aspect-oriented solution with the original system. The strategy is applied to the JHotDraw open source project and illustrated on a group of selected concerns. Finally, we abstract from the case study and present a number of generic refactorings which contribute to an incremental aspect-oriented refactoring process and associate particular types of crosscutting concerns to the model and features of the employed aspect language. The contributions of this paper are both in the area of supporting migration towards aspect-oriented solutions and supporting the development of aspect languages that are better suited for such migration

    Identifying aspects using fan-in analysis

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    The issues of code scattering and tangling, thus of achieving a better modularity for a system's concerns, are addressed by the paradigm of aspect orientation. Aspect mining is a reverse engineering process that aims at finding crosscutting concerns in existing systems. This paper describes a technique based on determining methods that are called from many different places (and hence have a high 'fan-in') to identify candidate aspects in a number of open-source Java systems. The most interesting aspects identified are discussed in detail, which includes several concerns not previously discussed in the aspect-oriented literature. The results show that a significant number of aspects can be recognized using fan-in analysis, and that the technique is suitable for a high degree of automatio

    Time-resolved kinetic assessment of the role of singlet and triplet excited states in the photocatalytic treatment of pollutants at different concentrations

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    [EN] A kinetic-based rationale to assess the role of each excited species in thermodynamically favoured photocatalytic processes at different pollutant concentrations, has been developed and illustrated with new experimental data. Specifically, 2,4,6-triphenylthiapyrylium (TPTP+) salt has been chosen as a representative organic compound capable to act as photocatalyst, and the possible involvement of its excited states in the photodegradation of pollutants commonly found in aqueous ecosystems has been investigated using five chemicals, namely acetaminophen, acetamiprid, caffeine, clofibric acid and carbamazepine. First, steady-state photolysis has been carried out under simulated solar irradiation in the presence of TPTP+, and second, photophysical measurements (fluorescence and laser flash photolysis) have been performed in order to obtain reliable fast kinetic data. Thermodynamic considerations allow ruling out energy transfer processes, while the kinetic results are in good agreement with an electron transfer to the triplet excited state of TPTP+. Hence, the higher the intersystem crossing quantum yield the better. Although quenching of the singlet excited state is also observed, the contribution of this reactive species is only minor, due to its shorter lifetime. In general, the efficiency of a photocatalyst should be enhanced at higher pollutant concentrations, at which the intrinsic decay of the triplet excited state is minimized. (C) 2016 Elsevier B.V. All rights reserved.Financial support from Spanish Government (Grants SEV-2012-0267, CTQ2012-38754-C03-03 and CTQ2015-69832-C4-4-R) and Generalitat Valenciana (Prometeo Program) is gratefully acknowledged. R. Martinez-Haya thanks financial support from Spanish Government (Grant SEV-2012-0267). We also thank support from VLC/Campus.Martínez-Haya, R.; Gomis, J.; Arques Sanz, A.; Marín García, ML.; Amat Payá, AM.; Miranda Alonso, MÁ. (2017). Time-resolved kinetic assessment of the role of singlet and triplet excited states in the photocatalytic treatment of pollutants at different concentrations. Applied Catalysis B Environmental. 203:381-388. https://doi.org/10.1016/j.apcatb.2016.10.042S38138820

    Cysteine-based 3-substituted 1, 5-benzoxathiepin derivatives: Two new classes of anti-proliferative agents

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    Two distinct series of the 3-amino-1, 5-benzoxathiepin scaffold, derived from L-cysteine, were synthesized and evaluated for their anti-proliferative activity in the breast cancer MDA-MB-231 and MCF-7 cells, and in the ovarian carcinoma SKOV-3 cell line. (3R)-Amino-3, 4-dihydro-2H-1, 5-benzoxathiepin [(R)-10] was diversified into two forms: (a) by incorporating different amino acids at its position 3, through an amide bond; and (b) by construction of the purine ring to give 6-chloro-9-[2-(3, 4-dihydro-2H-1, 5-benzoxathiepin-(3R)-yl)]-9H-purine [(R)-28]. Nevertheless, when the introduction of iodine was tried at position 2 of the purine ring of (R)-28, 2-{[2-(6-chloro-2-iodo-9H-purin-9-yl) prop-2-en-1-yl] thio} phenol (34) was obtained. Compound 34 shows activity against cancer cells. Interestingly, 34 inhibits mammosphere formation at the micromolar range, demonstrating activity against cancer stem cells. Although further studies of its targets and mechanism of action are needed, these findings support the therapeutic potential of this compound in cancer

    Discrete Variational Optimal Control

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    This paper develops numerical methods for optimal control of mechanical systems in the Lagrangian setting. It extends the theory of discrete mechanics to enable the solutions of optimal control problems through the discretization of variational principles. The key point is to solve the optimal control problem as a variational integrator of a specially constructed higher-dimensional system. The developed framework applies to systems on tangent bundles, Lie groups, underactuated and nonholonomic systems with symmetries, and can approximate either smooth or discontinuous control inputs. The resulting methods inherit the preservation properties of variational integrators and result in numerically robust and easily implementable algorithms. Several theoretical and a practical examples, e.g. the control of an underwater vehicle, will illustrate the application of the proposed approach.Comment: 30 pages, 6 figure

    The littoral sea cucumbers (Echinodermata: Holothuroidea) of Guam re-assessed - a diversity curve that still does not asymptote

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    The Micronesian island of Guam has been an important site for the study of littoral tropical holothuriantaxonomy for almost 200 years. Despite substantial attention by both expeditions and resident taxonomists, new records arestill regularly added to the fauna, demonstrating the challenge of documenting even such large and well-known animals ina small hyper-diverse area. Guam is the type locality of species described by Quoy & Gaimard (1833) and Brandt (1835).A survey of the sea cucumber fauna by Rowe & Doty (1977) led to one of the most used guides for the identification oftropical Pacific sea cucumbers because of the color illustrations of living animals it presented. Focus on echinodermsincluding holothurians continued with numerous new records added in the following decades. Paulay (2003a) summarizedthe fauna last, recording 46-47 species. At this stage the fauna was thought to be well documented. A week-long workshopon holothurian systematics sponsored by the National Science Foundation PEET (Partnerships for Enhancing Expertise inTaxonomy) project in 2010 included a substantial field work component, sampling both during the day and night, withsnorkeling and SCUBA, across a variety of habitats. This survey yielded 40 species, including numerous new records andeven species. Further sampling by Kerr’s lab since the workshop has added additional records. The littoral holothuroidfauna of Guam now comprises 65 species in 17 genera and 7 families. Half of the 19 newly recorded species are the resultof unravelling cryptic species in complexes, the other half are based on new collections. Eleven species are known fromsingle specimens, suggesting that much still remains to be learned about the fauna
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