Sensitivity and Controllability of Systems Governed by Integral Equations Via Proximal Analysis

AbstractIn this paper, we are concerned with the basic problem defined in [9]. Formulas for δV(0)and δ∞V(0),respectively the generalized and asymptotic gradient of the value function at zero, corresponding to an L2 -additive perturbation of dynamics are given. Under the normality condition, δV(0)turns out to be a compact subset of L2, formed entirely of arcs, and V is locally finite and Lipschitz at 0. Moreover, estimations of the generalized directional derivative and Dini's derivative of V at 0 are derived. Supplementary conditions imply that Dini's derivative of V at 0 exists, and V is actually strictly differentiate at this point.</jats:p

Relaxed Optimal Control Problems Governed by Integral Equations

AbstractIn this paper, a maximum principle is proved for relaxed optimal control problems governed by integral equations. The basic technique is the penalty function method of Berkovitz, but since data are not necessarily differentiable, we work with Clarke′s generalized gradient for functions and normal cone for sets

Production of polyhydroxyalkanoates from methanol by the new methylotrophic bacteria Methylobacterium sp. GW2

A new bacterial strain, isolated from groundwater contaminated with explosives, was characterized as a pink-pigmented facultative methylotroph, affiliated to the genus Methylobacterium. The bacterial isolate designated as strain GW2 was found capable of producing the homopolymer poly-3-hydroxybutyrate (PHB) from various carbon sources such as methanol, ethanol, and succinate. Methanol acted as the best substrate for the production of PHB reaching 40 % w/w dry biomass. PHB accumulation was observed to be a growth-associated process, so that there was no need for two-step fermentation. Optimal growth occurred at 0.5 % (v/v) methanol concentration, and growth was strongly inhibited at [Formula: see text] concentration above 2 % (v/v). Methylobacterium sp. strain GW2 was also able to accumulate the copolyester poly-3-hydroxybutyrate-poly-3-hydroxyvalerate (PHB/HV) when valeric acid was supplied as an auxiliary carbon source to methanol. After 66 h, a copolymer content of 30 % (w/w) was achieved with a PHB to PHV ratio of 1:2. Biopolymers produced by strain GW2 had an average molecular weight ranging from 229,350 to 233,050 Da for homopolymer PHB and from 362,430 to 411,300 Da for the copolymer PHB/HV.NRC publication: Ye

Seasonal variation of lipid content and fatty acid composition of<i>Sardinella aurita</i>from the Tunisian coast

This study was conducted to clarify the seasonal variation of the chemical composition of the TunisianSardinella auritawith a focus on the total lipid content. The chemical composition showed a large fluctuation over years in response to various factors. For the entire fish, lipid content was lower in July (2.50%), but higher in November (10.25%). It varies with seasons in inverse proportion to water content. Interestingly, it was found that red muscle have much higher lipid content than white muscle and the entire fish body. The major fatty acids inS. auritalipids were palmitic acid, palmitoleic acid, eicosapentaenoic acid, docosahexaenoic acid and myristic acid. Palmitic acid comprised the main proportion (23.9%). The high amounts of saturated and monounsaturated fatty acids in the screened species are almost in agreement with other studies. Moreover, the percentage of omega-3 fatty acids (25%) was very similar to that in oil production commercial fish.</jats:p

Impacts of climate change on the tourist-carrying capacity at La Playa beach (Sardinia, IT)

It is largely acknowledged that global mean sea level is rising and accelerating increasing low-lying coastal communities’ exposure and vulnerability. The IPCC AR5 identified the Mediterranean Sea as one of the semi-enclosed seas with projected high rate. Impacts of sea level rise (SLR) at local scale affect the number of visitors in highly vulnerable beaches and previous paper have quantified these adverse effects. In this paper we want to say that coastal climate change is not just sea level rise and other climatic factors can affect the optimal beach carrying capacity in complex and uncertain ways. Specifically, the paper shows that the effects of selected climatic factors as wave, rainfall and wind can be opposite to that of SLR and the beach management could even benefit from those trends