5,991 research outputs found
What do experimental data "say" about growth of hadronic total cross-section?
We reanalyse and high energy data of the elastic scattering
above GeV on the total cross-section and on the
forward -ratio for various models of Pomeron, utilizing two methods. The
first one is based on analytic amplitudes, the other one relies on assumptions
for and on dispersion relation for . We argue that it is
not possible, from fitting only existing data for forward scattering, to select
a definite asymptotic growth with the energy of . We find
equivalent fits to the data together with a logarithmic Pomeron giving a
behavior , and with
a supercritical Pomeron giving a behavior ,
.Comment: LaTeX, 18 pages, 5 eps figures included, to be published in Il Nuovo
Ciment
Critical sets of nonlinear Sturm-Liouville operators of Ambrosetti-Prodi type
The critical set C of the operator F:H^2_D([0,pi]) -> L^2([0,pi]) defined by
F(u)=-u''+f(u) is studied. Here X:=H^2_D([0,pi]) stands for the set of
functions that satisfy the Dirichlet boundary conditions and whose derivatives
are in L^2([0,pi]). For generic nonlinearities f, C=\cup C_k decomposes into
manifolds of codimension 1 in X. If f''0, the set C_j is shown to be
non-empty if, and only if, -j^2 (the j-th eigenvalue of u -> u'') is in the
range of f'. The critical components C_k are (topological) hyperplanes.Comment: 6 pages, no figure
Using global analysis, partial specifications, and an extensible assertion language for program validation and debugging
We discuss a framework for the application of abstract interpretation as an aid during program development, rather than in the more traditional application of program optimization. Program validation and detection of errors is first performed statically by comparing (partial) specifications written in terms of assertions against information obtained from (global) static analysis of the program. The results of this process are expressed in the user assertion language. Assertions (or parts of assertions) which cannot be checked statically are translated into run-time tests. The framework allows the use of assertions to be optional. It also allows using very general properties in assertions, beyond the predefined set understandable by the static analyzer and including properties defined by user programs. We also report briefly on an implementation of the framework. The resulting tool generates and checks assertions for Prolog, CLP(R), and CHIP/CLP(fd) programs, and integrates compile-time and run-time checking in a uniform way. The tool allows using properties such as types, modes, non-failure, determinacy,
and computational cost, and can treat modules separately, performing incremental analysis
Anomalous response of superconducting titanium nitride resonators to terahertz radiation
We present an experimental study of KIDs fabricated of atomic layer deposited
TiN films, and characterized at radiation frequencies of ~GHz. The
responsivity to radiation is measured and found to increase with increasing
radiation powers, opposite to what is expected from theory and observed for
hybrid niobium titanium nitride / aluminium (NbTiN/Al) and all-aluminium
(all-Al) KIDs. The noise is found to be independent of the level of the
radiation power. The noise equivalent power (NEP) improves with higher
radiation powers, also opposite to what is observed and well understood for
hybrid NbTiN/Al and all-Al KIDs. We suggest that an inhomogeneous state of
these disordered superconductors should be used to explain these observations
Bunge’s Mathematical Structuralism Is Not a Fiction
In this paper, I explore Bunge’s fictionism in philosophy of mathematics. After an overview of Bunge’s views, in particular his mathematical structuralism, I argue that the comparison between mathematical objects and fictions ultimately fails. I then sketch a different ontology for mathematics, based on Thomasson’s metaphysical work. I conclude that mathematics deserves its own ontology, and that, in the end, much work remains to be done to clarify the various forms of dependence that are involved in mathematical knowledge, in particular its dependence on mental/brain states and material objects
Projective representation of k-Galilei group
The projective representations of k-Galilei group G_k are found by
contracting the relevant representations of k-Poincare group. The projective
multiplier is found. It is shown that it is not possible to replace the
projective representations of G_k by vector representations of some its
extension.Comment: 15 pages Latex fil
Seletividade de produtos fitossanitários utilizados na cultura da soja para pupas de Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae).
O objetivo do trabalho foi avaliar o efeito de produtos fitossanitários sobre pupas de Trichogramma pretiosum. Foram conduzidos três bioensaios em delineamento inteiramente casualizado com 11 tratamentos e cinco repetições. Em cada repetição, ovos de Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae) foram utilizados como hospedeiro alternativo, sendo aderidos em cartelas de cartolina de 1 cm2 com solução de goma arábica à 40% e oferecidos para o parasitismo por 24h. Após 168-192h do parasitismo, quando os parasitoides estavam na fase de pupa, as cartelas foram mergulhadas por cinco segundos nos tratamentos testados. Avaliou-se a sobrevivência dos indivíduos tratados e a redução na emergência dos parasitoides foi classificada segundo as normas da IOBC. Os inseticidas flufenoxurom (Cascade®) 10, diflubenzurom (Dimilin®) 20 e metoxifenozide (Intrepid 240SC®) 21,6 e 36 g i.a. ha-1 foram classificados como inócuos. Permetrina (Valon 384 CE®) 49,92; betaciflutrina 12,5 + imidacloprido 100 (Connect®) e gama-cialotrina (Stallion 150SC®) 3,75 g i.a. ha-1 foram levemente nocivos. Clorpirifós (Lorban 480BR®) 384 e espinosade (Tracer®) 24 g i.a. ha-1 foram moderadamente nocivos. Os herbicidas glifosato 720 + imazetapir 90 (Alteza®); s-metolacloro (Dual Gold®) 1920; flumioxazina (Flumyzin 500®) 60; clomazona (Gamit®) 1000; glifosato 2880 (Gliz 480SL®); dicloreto de paraquate 600 + diurom 300 (Gramocil®); glifosato 1200 (Roundup Ready®); foram classificados como inócuos e os herbicidas 2,4-D (DMA 806BR®) 1209; dicloreto de paraquate (Gramoxone®) 600; glifosato (Roundup Transorb®) 2592 g i.a. ha-1 classificados como levemente nocivos. Os fungicidas tiofanato-metílico (Cercobin 500 SC®) 400; flutriafol 60 + tiofanato-metílico 300 (Celeiro®); carbendazin (Derosal 500SC®) 250; tebuconazole (Folicur EC®) 150; flutriafol (Impact®) 125; tebuconazole 120 + trifloxistrobina 60 (Nativo®); epoxiconazole 30 + piraclostrobina 79,8 (Opera®); epoxiconazole (Opus SC®) 12,5; azoxistrobina (Priori®) 50; azoxistrobina 60 + ciproconazole 24 (Priori Xtra®) g i.a. ha-1 foram classificados como inócuos a T. pretiosum na fase de desenvolvimento avaliada (pupa). Dentre os produtos avaliados, aqueles classificados como inócuos devem ser priorizados no manejo integrado de pragas (MIP) por compatibilizar o uso do controle químico sem prejudicar o controle biológico. Do mesmo modo, os produtos classificados como moderadamente nocivos devem ser evitados sempre que possível ou substituídos por outro de menor impacto
An assertion language for constraint logic programs
In an advanced program development environment, such as that discussed in the introduction of this book, several tools may coexist which handle both the program and information on the program in different ways. Also, these tools may interact among themselves and with the user. Thus, the different tools and the user need some way to communicate. It is our design principie that such communication be performed in terms of assertions. Assertions are syntactic objects which allow expressing properties of programs. Several assertion languages have been used in the past in different contexts, mainly related to program debugging. In this chapter we propose a general language of assertions which is used in different tools for validation and debugging of constraint logic programs in the context of the DiSCiPl project. The assertion language proposed is parametric w.r.t. the particular constraint domain and properties of interest being used in each different tool. The language proposed is quite general in that it poses few restrictions on the kind of properties which may be expressed. We believe the assertion language we propose is of practical relevance and appropriate for the different uses required in the tools considered
Assessment of the corneal collagen organization after chemical burn using second harmonic generation microscopy
The organization of the corneal stoma is modified due to different factors, including pathology, surgery or external damage. Here the changes in the organization of the corneal collagen fibers during natural healing after chemical burn are investigated using second harmonic generation (SHG) imaging. Moreover, the structure tensor (ST) was used as an objective tool for morphological analyses at different time points after burn (up to 6 months). Unlike control corneas that showed a regular distribution, the collagen pattern at 1 month of burn presented a non-organized arrangement. SHG signal levels noticeably decreased and individual fibers were hardly visible. Over time, the healing process led to a progressive re-organization of the fibers that could be quantified through the ST. At 6 months, the stroma distribution reached values similar to those of control eyes and a dominant direction of the fibers re-appeared. The present results show that SHG microscopy imaging combined with the ST method is able to objectively monitor the temporal regeneration of the corneal organization after chemical burn. Future implementations of this approach into clinically adapted devices would help to diagnose and quantify corneal changes, not only due to chemical damages, but also as a result of disease or surgical procedures
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