1,932 research outputs found

    Generalized Artin–Mumford curves over finite fields

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    Let Fq be the finite field of order q=ph with p>2 prime and h>1, and let FqÂŻ be a subfield of Fq. From any two qÂŻ-linearized polynomials L1,L2∈F‟q[T] of degree q, we construct an ordinary curve X(Ljavax.xml.bind.JAXBElement@3de21171,Ljavax.xml.bind.JAXBElement@44e73174) of genus g=(q−1)2 which is a generalized Artin–Schreier cover of the projective line P1. The automorphism group of X(Ljavax.xml.bind.JAXBElement@265fda03,Ljavax.xml.bind.JAXBElement@5ee20ea3) over the algebraic closure F‟q of Fq contains a semidirect product Σ⋊Γ of an elementary abelian p-group ÎŁ of order q2 by a cyclic group Γ of order q¯−1. We show that for L1≠L2, Σ⋊Γ is the full automorphism group Aut(X(Ljavax.xml.bind.JAXBElement@4b2f1fff,Ljavax.xml.bind.JAXBElement@2ddc4e9)) over F‟q; for L1=L2 there exists an extra involution and Aut(X(Ljavax.xml.bind.JAXBElement@2daa9e77,Ljavax.xml.bind.JAXBElement@1c89ae0d))=Σ⋊Δ with a dihedral group Δ of order 2(q¯−1) containing Γ. Two different choices of the pair L1,L2 may produce birationally isomorphic curves, even for L1=L2. We prove that any curve of genus (q−1)2 whose F‟q-automorphism group contains an elementary abelian subgroup of order q2 is birationally equivalent to X(Ljavax.xml.bind.JAXBElement@1301e61e,Ljavax.xml.bind.JAXBElement@61aac551) for some separable qÂŻ-linearized polynomials L1,L2 of degree q. We produce an analogous characterization in the special case L1=L2. This extends a result on the Artin–Mumford curves, due to Arakelian and KorchmĂĄros [1]

    On maximal curves that are not quotients of the Hermitian curve

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    For each prime power ℓ the plane curve Xℓwith equation Yℓ2ℓ+1=Xℓ2-X is maximal over Fℓ6. Garcia and Stichtenoth in 2006 proved that X3is not Galois covered by the Hermitian curve and raised the same question for Xℓwith ℓ>3; in this paper we show that Xℓis not Galois covered by the Hermitian curve for any ℓ>3. Analogously, Duursma and Mak proved that the generalized GK curve Cℓnover Fℓ2nis not a quotient of the Hermitian curve for ℓ>2 and n≄5, leaving the case ℓ=2 open; here we show that C2nis not Galois covered by the Hermitian curve over F22nfor n≄5

    Complete (k,3)-arcs from quartic curves

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    Complete (Formula presented.) -arcs in projective planes over finite fields are the geometric counterpart of linear non-extendible Near MDS codes of length (Formula presented.) and dimension (Formula presented.). A class of infinite families of complete (Formula presented.) -arcs in (Formula presented.) is constructed, for (Formula presented.) a power of an odd prime (Formula presented.). The order of magnitude of (Formula presented.) is smaller than (Formula presented.). This property significantly distinguishes the complete (Formula presented.) -arcs of this paper from the previously known infinite families, whose size differs from (Formula presented.) by at most (Formula presented.)

    Potential Benefits of Remote Working on Urban Mobility and Related Environmental Impacts: Results from a Case Study in Italy

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    Remote working is increasingly seen as an effective model in several countries in the last decade, mainly thanks to the development of information and communication technologies in support of common daily working tasks. The emergence of the COVID-19 pandemic has represented a pivotal moment for the adoption of remote working in multiple sectors, with positive effects on the environmental impacts caused by the daily commuting of workers. However, due to the fact that pandemic-induced remote working has represented a major forced experiment on a global scale, and that it has often been imposed rather than chosen by employees, workers’ well-being has not always been ensured. This research work presents an analysis of a wide survey of remote workers in public administrations in four different provinces in Italy, with the aim of assessing the main characteristics of the users and the related environmental benefits. Survey data refer to remote workers before COVID-19, thus representing workers who have freely chosen to work from home for different reasons. The results of this work represent a useful tool with which to support the definition of new remote work strategies that could help policy makers reduce a part of the systematic mobility demand. We have also calculated average energy and emission savings to provide useful indicators for a preliminary estimation of the potential environmental benefits of remote working. Considering the entire sample of respondents, workers who would have commuted at least partially by car have saved on average 6 kg of CO2 per day thanks to remote working (with an average round-trip commuting distance of approximately 35 km). The current results will be supplemented by the results of a new survey underway, aimed at evaluating the differences of remote working experiences during the emergency response to COVID-19

    Quantitative analysis of headspace volatile compounds using comprehensive two-dimensional gas chromatography and their contribution to the aroma of Chardonnay wine.

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    The quantitative determination of volatile compounds of Chardonnay wines using HS-SPME-GC × GC/TOFMS along with the determination of odor activity value (OAV) and relative odor contribution (ROC) of volatiles are reported for the first time. The use of GC × GC/TOFMS for the analysis of Chardonnay wine of Serra Gaucha resulted in the tentative identification of 243 compounds, showing the superior performance of this analytical technique for this specific varietal wine, considering that the number of compounds usually separated by 1D-GC for this type of wine is lower. Furthermore, 42 compounds co-eluted in the first dimension and 34 of them were separated in the second dimension, while the others were resolved by spectral deconvolution (8), which indicates that the conventional 1D-GC/MS may result in misleading results. The calculation of OAV and ROC allowed the determination of the volatile compounds that presented the greater contribution to wine aroma. Ethyl octanoate, ethyl hexanoate, ethyl butanoate, and beta-damascenone showed the highest OAV and ROC values, although other 43 compounds showed also potential to contribute to wine aroma. Figures of merit of the developed method were: accuracies from 92.4 to 102.6%, repeatability from 1.2% to 13.4%, LOD from 0.001 ?g L?1 (ethyl isovalerate and hexanoic acid) to 2.554 ?g L?1 (ethyl 3-hydroxybutanoate), LOQ from 0.003 ?g L?1 (ethyl isovalerate and hexanoic acid) to 7.582 ?g L?1 (ethyl 3-hydroxybutanoate)

    Rheological investigation and simulation of a debris-flow event in the Fella watershed

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    Abstract. To set an approach for the future territorial planning, the Geological Survey of Friuli Venezia Giulia Region, through the researchers of Trieste University, started a program of debris-flow risk analysis using Flo-2D software as tool to delimit the hazardous areas. In the present paper, as a case study, a debris flow, called Fella sx, occurring in a torrent catchment was analyzed. The choice was due to the abundance of information about past events, inundated areas, rain fall, geology and to its representativeness. An initial back-analysis investigation identified a couple of representative rheological parameters. Riverbed samples were collected, sieve analyses were performed and rheological tests were carried out on the fraction finer than 0.063 mm using a rotationally controlled stress rehometer equipped with the serrated parallel plate geometry. The shear dependent behaviour was examined at different concentrations ranging from 33 to 48%, by weight. Viscosity data treatment was performed to determine the most suitable rheological model to provide the best approximation of the debris-flow behaviour. The rheological parameters, derived from experimental data, were used and compared with those obtained through the back-analysis and with the real inundated area. Data obtained through rheological analysis are useful in constructing scenarios of future events where no data for back-analysis are available

    The effect of renal diet in association with enalapril or benazepril on proteinuria in dogs with proteinuric chronic kidney disease

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    Treating proteinuria in dogs reduces the progression of chronic kidney disease (CKD); renal diets and angiotensin - converting enzyme (ACE)-inhibitors are cornerstones of treatment. Whether different ACE-inhibitors have distinct kidney protective effects is unknown; it is therefore hypothesized that renal diets and enalapril or benazepril have different beneficial effects in proteinuric CKD dogs. Forty-four dogs with proteinuric CKD (IRIS stages 1-4) were enrolled in the study and were fed renal diet for 30 days. Thereafter, they were randomly assigned to one of 2 groups. Dogs in group A (n=22) received enalapril (0.5 mg/kg, q12h) and in group B (n=22) benazepril (0.5 mg/kg, q24h); in both groups, dogs were fed the same renal diet. After randomization, dogs were monitored for 120 days. Body weight and body condition score (BCS), serum concentrations of creatinine, blood urea nitrogen (BUN), albumin and total proteins, and urine protein-to-creatinine (UPC) ratio were compared at different time-points. After 30 days of renal diet, creatinine, BUN and UPC ratio decreased significantly (p<0.0001). Compared to randomization, body weight, BCS, albumin, total proteins, creatinine and BUN did not vary during follow-up in the 44 dogs and differences between group A and B were not observed. However, the UPC ratio of group A at day 60, 90 and 150 was significantly lower than in group B and compared to randomization (p<0.05). In group B it did not vary overtime. It is concluded that the renal diet is beneficial to decrease creatinine, BUN and UPC ratio in proteinuric CKD dogs. Enalapril further ameliorates proteinuria if administered along with renal diet
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