Minimal Niven numbers

Define a(k,q) to be the smallest positive multiple of k such that the sum of its digits in base q is equal to k. The asymptotic behavior, lower and upper bound estimates of a(k,q) are investigated. A characterization of the minimality condition is also considered.Comment: 28 pages, 2 figure

Multiferroic (Nd,Fe)-doped PbTiO3 ceramics with coexistent ferroelectricity and magnetism at room temperature

We report the structural, dielectric, elastic, ferroelectric and ferromagnetic properties of multiferroic (Nd, Fe)-doped PbTiO3 perovskite ceramics with composition (Pb 0.88 Nd 0.08 )(Ti 0.94 Fe 0.04 Mn 0.02 )O 3 , prepared by different solid state reaction methods: the first one based on a single-stage calcination (Method I) and the second based on a double-stage calcination (Method II). Structural, dielectric and anelastic measurements evidenced a double phase transition for samples prepared by Method I, which has been attributed to phase separation. This phase separation has been confirmed also by TEM and HRTEM investigations. Samples prepared by Method II showed a single phase transition from paraelectric to ferroelectric phase. We found coexistent ferroelectric and ferromagnetic properties, also at room-temperature, but only for ceramics prepared by Method II. The crucial role of calcination process for avoiding phase separation and obtaining homogeneous structures with ferroelectric and ferromagnetic order is underlined

Advances in Vehicular Ad-hoc Networks (VANETs): challenges and road-map for future development

Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks (VANETs) over the past few years. A vehicular network consists of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system (ITS). Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS

Monotonic phinomial coefficients

DOI: 10.1017/S000497271600108

FIELD EVALUATION OF SOME STRAWBERRY CULTIVARS REGARDING THEIR BEHAVIOR TO FUNGAL PATHOGENS

The researches were done between 2012-2013, many observation and assessments being carried out in strawberry field, on the incidence (F%), severity (I notes; I %) and damages degree (DD%) of diseases which affect the strawberries foliage: Mycosphaerela fragariae - leaf spot, Podosphaera aphanis - powdery mildew and Diplocarpon earliana - leaf scorch. Under the environment of South-central of Roumania, the most tolerant cvs. on the Mycosphaerela fragariae - leaf spot were: ‘Cambridge Favourite’ (GA%=0.00-0.06) and ‘Mira’ (GA%=0.00-0.86). As regard the behavior on the Podosphaera aphanis - powdery mildew attack, the most tolerant cvs. were ‘Cambridge Favourite’, ‘Onebor’, ‘Idea’ (GA%=0.00) and ‘Elsanta’ (GA%=0.00-1.70). The most tolerant cvs. on the Mycosphaerela fragariae - leaf spot were: ‘Benton’, ‘Mira’, ‘Idea’ (GA%=0.00) and ‘Cambridge Favourite’ (GA%=0.00-0.03). ‘Mira’ and ‘Onebor’ are still used in strawberry breedin

Evoluzione recente del Delta del Danubio in base a documenti cartografici. Working Paper, depositato c/o BNCF 1/10/2009, ID 2610, 66 pagg.

Il volume \ue8 composto prevalentemente di immagini cartografiche dal passato alle attuali mappe digital

Sediment Transfer and Geomorphological Evolution in River Systems & Coastal Zones in Italy, Romania and Greece

This work deals with with the comparative account and evaluation of the impact to the environment and especially the changes to the sediments transfer and geomorphological evolution in river systems and coastal zones in Italy, Romania, and Greece