Evaluation of sustainability of a city through fuzzy logic

The sustainable indicators are characterized by a low degree of aggregation and a high amount of information. An indicator must show a synthetic representation of a real environmental, by using a value or a parameter, so that they can be easily used by policy makers. It is necessary to connect, therefore, the various systems in an appropriately integrated sustainable system. The indicators need to be aggregated based on the structure of the data. Each indicator must to be defined through a weight with reference to another weighted indicator.     

A model to manage a large number of transactions: a case study

The aim of this paper is to present a model for the Computer Centre of an important Italian banking group. The model groups data and transactions to deal with the large dimension of the Centre. The transactions arrivals are considered as Posson stochastic variables and the probability values are estimated. Some computational results are given.     

Copper resistant human hepatoblastoma mutant cell lines without metallothionein induction overexpress ATP7B

Mutant human hepatoblastoma cell lines resistant to copper toxicity were isolated from mutagenized HuH7. Two copper resistant cell lines (CuR), CuR 23 and CuR 27, had reduced basal expression of metallothionein (MT) messenger RNA (mRNA) and exhibited minimal or no increase in resistance to cadmium or zinc toxicity. Copper uptake, efflux of newly transported copper, glutathione content, and efflux rate were comparable with HuH7, whereas holoceruloplasmin synthesis and secretion were slightly decreased. Subcellular distribution of copper at steady-state showed an increase in organelle and membrane fractions with a reduction in cytosol. Expression of ATP7B mRNA was fivefold increased, and ATP7B protein approximately threefold increased in both CuR 23 and 27. Another cell line, CuR 41, showed increased basal expression of MT and ATP7B mRNA but not ATP7B protein, and resistance to cadmium and zinc toxicity. Copper uptake in CuR 41 was comparable with HuH7, but initial rates of efflux of copper and glutathione were reduced. The synthesis of holoceruloplasmin but not ceruloplasmin peptide was markedly diminished in CuR 41. Subcellular distribution of copper showed an increase in cytosolic and decreased organelle and membrane-associated copper. These data suggest that cellular resistance to copper toxicity was achieved in two independent cell lines without MT induction and that the induction of ATP7B may lead to the enhanced intracellular sequestration of copper by organelles.     

Methodology for estimating saving of primary energy with membrane operations in industrial processes

Membrane separation processes can realize significant savings of direct energy (e.g., oil, gas, coal) and indirect energy (intrinsically contained in the materials recovered and/or recycled). The methodology of the energy analysis in various industrial cycles is described, and the benefits of these operations, based principally on electrical energy consumption, are evaluated using the definition of “substitution coefficient” (primary energy saved vs. 1 kWh of electrical energy consumed). The industrial sectors where this methodology has been applied are: textile (recycle of water, dyes and chemicals); polymer manufacturing (recycle of caprolactame and water); the tanning industry (recycle of sulfides and protein recovery), the dairy industry (saving of thermal energy and recovery of fat substances); and tomato and orange juice concentration (saving of thermal energy). The analyses show very interesting values for the substitution coefficients confirming the convenience of membrane operations from an energetic viewpoint.     

Synchronization Using Pulse Edge Tracking in Optical Pulse-Position Modulated Communication Systems

A pulse-position modulated (PPM) optical communication system using narrow pulses of light for data transmission requires accurate time synchronization between transmitter and receiver. The presence of signal energy in the form of optical pulses suggests the use of a pulse edge-tracking method of maintaining the necessary timing. In this report the edge-tracking operation in a binary PPM system is examined, taking into account the quantum nature of the optical transmissions. Consideration is given first to "pure" synchronization using a periodic pulsed intensity, then extended to the case where position modulation is present and auxiliary bit decisioning is needed to aid the tracking operation. Performance analysis is made in terms of timing error and its associated statistics. Timing error variances are shown as a function of system signal-to-noise ratio.     

Carbon nanowall growth on carbon paper by hot filament chemical vapour deposition and its microstructure

Carbon nanowall films were synthesized by plasma enhanced hot filament chemical vapour deposition on carbon paper, a three dimensionally structured material. The micro-structured nature of the carbon paper, which is composed of an irregular and open mesh of carbon fibres, allowed one to determine the microstructure of the carbon nanowalls both at the tip and at the fibre–nanowall base interface. The number of graphenes which pile up to form the structure of a single nanowall ranges from 1 to 2 at the tip up to several 10s at the base, making this material suitable to study and eventually exploit the electronic properties of graphenes on a macroscopic scale. Such material is promising for electrochemical applications.     

NEM-FEM comparison on porthole die extrusion of AA-6082

Porthole die extrusion is a forming process used to manufacture hollow components with different shapes. This forming process is optimized to improve the welding line quality. Process optimization can be achieved by determining the influences that each process parameter has on the pressure along the welding plane. The construction complexity of the die results in research difficulty from an experimental point of view. Even the finite element method (FEM) presents relevant drawbacks primarily because of numerical codes are not capable of simulating the welding phase. Hence, the natural element method (NEM), which allows the joining phase of free surfaces, presents significant advantages. In this work, experimental results obtained using a flexible porthole die are discussed. A suitable 2D geometry was extracted from the die, and both FEM and NEM were conducted. A good agreement among the numerical results was recorded.     

Steady-state mathematical models of battery storage plants withline-commutated converters

Battery storage plants can be interfaced to electric power systems by AC/DC line-commutated converters, whose behavior is strongly influenced by AC and DC side interactions, and which can work in nonideal conditions such as those arising from voltage harmonics and imbalances. Mathematical models of battery storage plants with conventionally and nonconventionally controlled line-commutated converters are presented. The aim is to carry out a complete harmonic analysis in steady-state nonideal conditions. The models, which include the DC side of the converter, can be directly employed in an iterative harmonic analysis of a power system with converters. Numerical simulation results are discussed     

Study of the axially symmetric motion of an incompressible viscous fluid between two concentric rotating spheres

The research reported herein involves the study of the steady state and transient motion of a system consisting of an incompressible, Newtonian fluid in an annulus between two concentric, rotating, rigid spheres. The primary purpose of the research is to study the use of an approximate analytical method for analyzing the transient motion of the fluid in the annulus and the spheres which are started suddenly due to the action of prescribed torques. The problems include cases where: (a) one (or both) spheres rotate with prescribed constant angular velocities and (b) one sphere rotates due to the action of an applied constant or impulsive torque.In this research, the coupled solid and fluid equations of motion are linearized by employing the perturbation technique. The meridional dependence in these equations is removed by expanding the dependent variables in a series of Gegenbauer functions with variable coefficients and employing the orthogonality property of these functions. The equations for the variable coefficients are solved by separation of variables and Laplace transform methods. Results for the stream function, circumferential function, angular velocity of the spheres and torque coefficient are presented as a function of time for various values of the dimensionless system parameters.