429 research outputs found
HYDROMETEORS PRODUCTION AND ADVECTION IN A GRAVITY WAVE ENVIRONMENT
Production and advection of precipitating water in a prescribed, time dependent flow is investigated by means of a simple 2D model in order to predict the periodical behaviour of rain rate and pressure which was observed in the Po valley during IOP8 of MAP. The (x,z,t)-dependent wave perturbations on wind and temperature fields were derived from a linear stability analysis and are superimposed on z-dependent background fields. The wave influence
on the hydrometeors production and advection is discussed
Global well-posedness of the Kirchhoff equation and Kirchhoff systems
This article is devoted to review the known results on global well-posedness
for the Cauchy problem to the Kirchhoff equation and Kirchhoff systems with
small data. Similar results will be obtained for the initial-boundary value
problems in exterior domains with compact boundary. Also, the known results on
large data problems will be reviewed together with open problems.Comment: arXiv admin note: text overlap with arXiv:1211.300
Međudjelovanje atmosfere s morem u Jadranu: simulacije bure i juga
Two simulations of the response of Adriatic Sea to severe wind performed by an atmosphere-ocean coupled model and the comparisons with observed data and modelled fields published in literature are presented. The model RAMS-DieCAST was applied to simulate the variations of sea currents and temperature profiles, from surface to bottom, induced by two episodes of intense wind over the Adriatic sea: a Bora wind event that occurred in January 1995 and a Sirocco wind event in November 2002. The results of the simulations are compared with observed data at the sea surface. In the Bora episode, the computed surface temperatures are compared with satellite SSTs and in situ observed temperatures; in the Sirocco event the simulated surface currents and temperatures are compared with experimental data collected by surface drifters released in different regions of the Adriatic Sea during the same Sirocco event. In both episodes the simulated temperature trends agree with the observed values and during the Sirocco episode the current fields are in quite good agreement with the drifter data. The modelled sea temperature and velocity fields show also a good concordance with other simulation results in literature.Dvije simulacije jakog vjetra nad Jadranom simuliraju se združenim atmosfersko-oceanografskim modelom te se analiziraju i uspoređuju s mjerenjima i drugim objavljenim modeliranim poljima. U tu svrhu se koristi model RAMS-DieCAST za simulaciju promjena morskih struja i temperaturnih profila po vertikali, uzrokovanih dvjema epizodama intenzivnog vjetra nad Jadranom: burom u siječnju 1995. godine i jugom u studenom 2002. godine. Rezultati simulacija se uspoređuju s opažanjima na morskoj površini. Tijekom bure, modelirana površinska temperatura uspoređuje se s površinskom temperaturom mora dobivene satelitskim mjerenjima i mjerenjima temperature u određenim točkama prostora. Tijekom juga, simulirane površinske struje i temperature se uspoređuju s eksperimentalnim mjerenjima dobivenih na temelju površinskih driftera koji su pušteni u različitim dijelovima Jadrana za istu epizodu. U obje epizode trendovi simulirane temperature dobro se podudaraju s opažanjima. Također se tijekom juga, površinske struje dobro podudaraju s mjerenjima driftera. Modelirana temperatura mora kao i vektorsko polje brzina pokazuju dobro slaganje s rezultatima sličnih simulacija u literaturi
Prediction of chemical composition and peroxide value in unground pet foods by near-infrared spectroscopy
The massive development of the pet food industry in recent years has lead to the formulation of hundreds of canine and feline complete extruded foods with the objective of meeting both the needs of the animals and numerous demands from pet owners. In the meantime, highly variable raw material compositions and the industry's new production techniques oblige manufacturers to monitor all phases of the extrusion process closely in order to ensure the targeted composition and quality of the products. This study aimed at evaluating the potential of infrared technology (visible and near-infrared spectrophotometer; 570-1842 nm) in predicting the chemical composition and peroxide value (PV) of unground commercial extruded dog foods. Six hundred and forty-nine commercial extruded dog foods were collected. For each product, an unground aliquot was analysed by infrared instrument while a second aliquot was sent to a laboratory for proximate analysis and PV quantification. The wide range of extruded dog food typologies included in the study was responsible for the wide variability observed within each nutritional trait, especially crude fibre and ash. The mean value of the 208 pet foods sampled for PV quantification was 17.49 mEq O2/kg fat (min 2.2 and max 94.10 mEq O2/kg fat). The coefficients of determination in cross-validation of NIRS prediction models were 0.77, 0.97, 0.83, 0.86, 0.78 and 0.94 for moisture, crude protein, crude fat, crude fibre, ash and nitrogen-free extract (NFE) respectively. PV prediction was less precise, as demonstrated by the coefficient of determination in cross-validation (0.66). The results demonstrated the potential of NIRS in predicting chemical composition in unground samples, with lower accuracy for moisture and ash, while PV prediction models suggest use for screening purposes only
Međudjelovanje atmosfere s morem u Jadranu: simulacije bure i juga
Two simulations of the response of Adriatic Sea to severe wind performed by an atmosphere-ocean coupled model and the comparisons with observed data and modelled fields published in literature are presented. The model RAMS-DieCAST was applied to simulate the variations of sea currents and temperature profiles, from surface to bottom, induced by two episodes of intense wind over the Adriatic sea: a Bora wind event that occurred in January 1995 and a Sirocco wind event in November 2002. The results of the simulations are compared with observed data at the sea surface. In the Bora episode, the computed surface temperatures are compared with satellite SSTs and in situ observed temperatures; in the Sirocco event the simulated surface currents and temperatures are compared with experimental data collected by surface drifters released in different regions of the Adriatic Sea during the same Sirocco event. In both episodes the simulated temperature trends agree with the observed values and during the Sirocco episode the current fields are in quite good agreement with the drifter data. The modelled sea temperature and velocity fields show also a good concordance with other simulation results in literature.Dvije simulacije jakog vjetra nad Jadranom simuliraju se združenim atmosfersko-oceanografskim modelom te se analiziraju i uspoređuju s mjerenjima i drugim objavljenim modeliranim poljima. U tu svrhu se koristi model RAMS-DieCAST za simulaciju promjena morskih struja i temperaturnih profila po vertikali, uzrokovanih dvjema epizodama intenzivnog vjetra nad Jadranom: burom u siječnju 1995. godine i jugom u studenom 2002. godine. Rezultati simulacija se uspoređuju s opažanjima na morskoj površini. Tijekom bure, modelirana površinska temperatura uspoređuje se s površinskom temperaturom mora dobivene satelitskim mjerenjima i mjerenjima temperature u određenim točkama prostora. Tijekom juga, simulirane površinske struje i temperature se uspoređuju s eksperimentalnim mjerenjima dobivenih na temelju površinskih driftera koji su pušteni u različitim dijelovima Jadrana za istu epizodu. U obje epizode trendovi simulirane temperature dobro se podudaraju s opažanjima. Također se tijekom juga, površinske struje dobro podudaraju s mjerenjima driftera. Modelirana temperatura mora kao i vektorsko polje brzina pokazuju dobro slaganje s rezultatima sličnih simulacija u literaturi
Influence of the Sonic Anemometer Temperature Calibration on Turbulent Heat-Flux Measurements
Drug resistance in B and non-B subtypes amongst subjects recently diagnosed as primary/recent or chronic HIV-infected over the period 2013–2016: Impact on susceptibility to first-line strategies including integrase strand-transfer inhibitors
Objectives To characterize the prevalence of transmitted drug resistance mutations (TDRMs) by plasma analysis of 750 patients at the time of HIV diagnosis from January 1, 2013 to November 16, 2016 in the Veneto region (Italy), where all drugs included in the recommended first line therapies were prescribed, included integrase strand transfer inhibitors (InNSTI). Methods TDRMs were defined according to the Stanford HIV database algorithm. Results Subtype B was the most prevalent HIV clade (67.3%). A total of 92 patients (12.3%) were expected to be resistant to one drug at least, most with a single class mutation (60/68–88.2% in subtype B infected subjectsand 23/24–95.8% in non-B subjects) and affecting mainly NNRTIs. No significant differences were observed between the prevalence rates of TDRMs involving one or more drugs, except for the presence of E138A quite only in patients with B subtype and other NNRTI in subjects with non-B infection. The diagnosis of primary/recent infection was made in 73 patients (9.7%): they had almost only TDRMs involving a single class. Resistance to InSTI was studied in 484 subjects (53 with primary-recent infection), one patient had 143C in 2016, a total of thirteen 157Q mutations were detected (only one in primary/recent infection). Conclusions Only one major InSTI-TDRM was identified but monitoring of TDRMs should continue in the light of continuing presence of NNRTI-related mutation amongst newly diagnosed subjects, sometime impacting also to modern NNRTI drugs recommended in first-line therapy
Wind generated rogue waves in an annular wave flume
We investigate experimentally the statistical properties of a wind-generated wave field and the spontaneous formation of rogue waves in an annular flume. Unlike many experiments on rogue waves, where waves are mechanically generated, here the wave field is forced naturally by wind as it is in the ocean. What is unique about the present experiment is that the annular geometry of the tank makes waves propagating circularly in an {\it unlimited-fetch} condition. Within this peculiar framework, we discuss the temporal evolution of the statistical properties of the surface elevation. We show that rogue waves and heavy-tail statistics may develop naturally during the growth of the waves just before the wave height reaches a stationary condition. Our results shed new light on the formation of rogue waves in a natural environment
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