Thermodynamic analysis of the province of Ravenna (Italy)

This is a thermodynamic analysis of the Province of Ravenna (Italy) and its districts (Ravenna, Faenza and Lugo) and an evaluation of entropy waste production based on a balance sheet of greenhouse gases. The method used is energy analysis. The results show that the Province and Ravenna are characterized by a heavy exploitation of local non renewable resources, Faenza strikes a good balance between economic development and environment conservation and Lugo is less sustainable than the others. The greenhouse gas balance shows that the Province emits 10.5 times the quantity of greenhouse gases that it adsorbs and that the emissions reduction is required in the energy sector, which is responsible for 92% of the total.     

Chemical waves and pattern formation in the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/water lamellar system

The present work deals with the spatially extended oscillatory Belousov Zhabotinsky reaction-diffusion system carried out in an anisotropic environment of phosphatidylcholines/water binary system, which presents layered aqueous domains separated by lipid bilayers. We report the occurrence of stable Turing patterns, spiral waves, and other exotic structures in phospholipids bilayers that are generally used as a models for cell plasma membranes.     

Visual detection of cysteine and homocysteine

The determination of cysteine and homocysteine levels is of great current interest for the monitoring of desease states. A new colorimetric method for the simultaneous detection of l-cysteine and l-homocysteine has been developed. A fluorescein derivative reacts with the above amino acids, producing their respective thiazolidines resulting in color changes. Interference from other amino acids and proteins is minimal.     

Environmental certification: a scientific tool for sustainability. Evaluation of possible indicators for the environmental performance evaluation (EPE) of Ravenna province (Italy)

Environmental certification is becoming the main tool for application of sustainable development principles. The European Regulation Emas and the international standard ISO 14001 both require for certification, to perform an environmental management system to prevent environmental impacts and to continuously improve environmental performance. For a good environmental performance evaluation (EPE), certification needs to use scientific methodologies and to interface with scientific research; here we proposed emergy analysis as a valid method for EPE and emergetic environmental performance and condition indicators (EPIs, ECIs) to monitor a territorial system: Ravenna province (Italy). Together with emergy indicators were selected other indicators for a deeper EPE: emitted/adsorbed CO2, energy consumptions, air and water pollution measures. The paper showed that Ravenna system has a good environmental performance and demonstrated how different indicators from the most advanced chemical research (chemical-physical, analytical, etc.) contribute to a complete EPE of a complex territorial system and are useful for environmental certification and sustainable development.     

Heavy metals content in rain water collected in three different locations in Italy during 1999

Rain water samples collected at three different locations in Italy during 1999 were analysed for heavy metals determination. Results for V, Cr, Mn, Co, Cu, Cd, Sb, Pb, Al and Ni are reported in this paper. For most of the elements higher concentration values have been measured in the samples from Alpe Gera (rural site): only for Cd and V were the concentrations higher at Pisa. The total annual deposition (microg m(-2) y(-1)) shows a similar behaviour, with Alpe Gera being the location with highest total annual input for Cr, Mn, Co, and in particular for Cu, Sb, Pb and Al. The reason of the higher deposition at a rural site in comparison to a urban one (Milan) is not known: further experimental work and investigations are needed. Generally, no evident seasonal trends have been observed for the measured concentrations, while few correlations have been found among elements within the same station. Crustal contribution to total concentration varies from about 20% for V to less than 1% for Cu, Cd, Sb, Pb and Ni.     

Thermal behavior of holo- and hemicellulose obtained from rice straw and bagasse

Thermal gravimetric analysis, and differential thermal behavior of holo- and hemicelluloses obtained from rice straw and bagasse were investigated. Degradation was found to be of first order reaction. The activation energy values and the rate constants were calculated from the kinetic of weight loss. Hemicellulose was found to be less stable than holocellulose, and the stability of the samples was arranged in the order, rice straw holo- > bagasse holo- > rice straw hemi- > bagasse hemicellulose. Degradation of rice straw (holo- as well as hemicellulose) was performed via two exothermic processes, whereas bagasse hemicellulose combustion was completed through three exothermic processes. The magnitude and the shape of the exotherms depend, mainly, on the chemical composition of the sample.     

Second-order subdifferentials of C1,1 functions and optimality conditions

We present second-order subdifferentials of Clarke's type of C ^1,1 functions, defined in Banach spaces with separable duals. One of them is an extension of the generalized Hessian matrix of such functions in ⁿ , considered by J. B. H.-Urruty, J. J. Strodiot and V. H. Nguyen. Various properties of these subdifferentials are proved. Second-order optimality conditions (necessary, sufficient) for constrained minimization problems with C ^1,1 data are obtained.This work was partially supported by the National Foundation for Scientific Investigations in Bulgaria under contract No. MM-406/1994.     

Selective monodeoxygenation of quinoxaline-amino acid and ester dioxides

Trimethyl phosphite selectively removes the N-1-oxygen in N-(3-methyl-2-quinoxaloyl) L-α-amino ester-1,4-dioxides, whereas it removes the N-4-oxygen in the corresponding series of dioxides lacking the C₃-Me. This selectivity reversal reflects the relative strength of the intrahydrogen-bridging to the N-1-oxygen. The monoxides having the favourable N-oxygen are not reduced to the quinoxalines, implying that the reagent requires doubling of the N-oxide function for deoxygenation. However, alkaline sodium dithionite removes the N-1-oxygen in both series of the amino acid-dioxides, as well as in the parent quinoxaline-2-carboxylic acid-dioxides, a result that contradicts the report stating removal of the N-4-oxygen. The N-oxygenated quinoxalinium ion ($\text{m}\text{e}$ 145 or 159) prevails in the MS of the 4-oxides, but it is not observed (<1%) for the isomeric 1-oxides. ¹H NMR, ¹³C NMR and UV spectral data also offer diagnostic criteria for differentiation between the isomeric 1- and 4-oxides. Aryl-heteryl “interaction” (as revealed by ¹H NMR, though not by ¹³C NMR in the aromatic amino ester dioxides) is not manifested in the corresponding monoxides.     

Spectrophotometric determination of some drugs for osteoporosis

Three simple, accurate and sensitive spectrophotometric methods are developed for the determination of some new drugs for the treatment of osteoporosis: risedronate sodium (I), alendronate sodium (II) and etidronate disodium (III). The first method is based on the measurement of difference in absorbance (Delta A) of risedronate sodium in 0.01 mol l(-1) hydrochloric and 0.1 mol l(-1) sodium hydroxide at 262 nm. Beer's law is obeyed over a concentration range of 15-150 microg ml(-1) with mean recovery 99.75+/-1.22 and molar absorptivity (epsilon) 1.891 x 10(3). The second method is based on the reaction of the primary amino group of (II) with ninhydrin reagent in methanolic medium in the presence of 0.05 mol l(-1) sodium bicarbonate. The colored product is measured at 568 nm, and the linearity range is found to be 3.75-45 microg ml(-1) with mean recovery 99.77+/-0.73 and epsilon 9.425 x 10(3). The third method is based on oxidation of the three mentioned drugs with ceric (IV) sulphate in 0.5 mol l(-1) sulphuric acid at room temperature and subsequent measurement of the excess unreacted cerium (IV) sulphate at 320 nm. The method obeyed Beer's law over a concentration range of 2-24 microg ml(-1) for the three drugs with mean recovery 99.79+/-1.16, 99.73+/-1.38 and 99.86+/-1.13 and epsilon 14.427 x 10(3), 13.813 x 10(3) and 14.000 x 10(3) for drugs I, II, III respectively. The proposed methods were successfully applied for the determination of the studied drugs in bulk powder and in pharmaceutical formulations. The results were found to agree statistically with those obtained the reported methods. Furthermore, the methods were validated according to USP regulations and also assessed by applying the standard addition technique.