Technological behaviour and recycling potential of spent foundry sands in clay bricks.

The feasibility of recycling spent foundry sand in clay bricks was assessed in laboratory, pilot line and industrial trials, using naturally occurring sand as a reference. Raw materials were analyzed by X-ray fluorescence, X-ray diffraction, particle size distribution, and leaching and combined to produce bodies containing up to 35% wt. sand. The extrusion, drying and firing behaviour (plasticity, drying sensitivity, mechanical strength, bulk density, water absorption, and shrinkage) were determined. The microstructure, phase composition, durability and leaching (EN 12457, granular materials, end-life step, European Waste Landfill Directive; NEN 7345, monolithic materials, use-life step, Dutch Building Material Decree) were evaluated for bricks manufactured at optimal firing temperature. These results demonstrate that spent foundry sand can be recycled in clay bricks. There are no relevant technological drawbacks, but the feasibility strongly depends on the properties of the raw materials. Spent foundry sand may be introduced into bricks up to 30% wt. Most of the hazardous elements from the spent foundry sand are inertized during firing and the concentrations of hazardous components in the leachates are below the standard threshold for inert waste category landfill excepting for chromium and lead; however, their environmental risk during their use-life step can be considered negligible.

Recycling PC and TV waste glass in clay bricks and roof tiles.

Disposal of PC monitors and TV sets is a growing problem, with over 40% of the weight of these systems comprised of waste glasses with high Pb (funnel) or Ba-Sr concentrations (panel), making them unsuitable for recycling and manufacturing new glass. A possible way to re-use these glasses is in the manufacturing of clay bricks and roof tiles. This possibility was appraised by laboratory simulation of the brickmaking process and technological characterization of unfired and fired products. The recycling of both funnel and panel glasses into clay bodies is technologically feasible, resulting in a substantially reduced plasticity behaviour during shaping-drying (implying a reduction of mechanical strength), and a promotion of sintering during firing. No significant release of Pb, Ba, and Sr was observed during the firing and leaching test for the carbonate-poor body; in contrast, some Pb volatilization during firing and Sr leaching were observed for the carbonate-rich body. Additions of 2 wt.% appear to be practicable, while 5 wt.% glass induces unacceptable modifications of technological properties. The recommended amount is within 2 and 4 wt.%, depending on the characteristics of the clay bodies. The main constraint is that the glass must have a particle size below the limit of the pan mills used in brickmaking (<1mm).

Heart rate stationarity in heart transplanted patients.

The heart rate stationary was studied by tachographic of 24 Holter analysis in 15 normal subjects and in 13 recipient subjects that were heart transplanted at least 5 years and that, at the time of our research, presented a very good post-operative course. To test the stationary heart rate we performed a scanning of Holter in qualified strips of four beats in which the three consecutive intervals demonstrate a constant acceleration or deceleration sequential variations of tachographic values. The results obtained demonstrated that in normal and transplanted subjects stationary and non stationary strips are evident. Both in normal and in transplanted subjects non-stationary strips are prevalent, although in different ways: in normal subjects the stationary and non-stationary ratio is 1:1.40; in transplanted subjects the ratio is 1:1.68. Non-stationary strips, that in the cartesian plane do not demonstrate any directional variation, in normal subjects are, on average, higher than in transplanted subjects. The same phenomenon is available for the strips with only one variation. The strips with three consecutive variations are much more evident (more 50%) in transplanted subjects. These strips are also more numerous compared to the sum of all the other strips with a single variation. The statistical analysis demonstrates that the difference between the normal and the transplanted subjects is significative. Our data can suggest an absent autonomic nervous system regulation and can confirm the results we obtained in these patients using a phase space analysis of the same Holter recording.

The autocorrelation of cardiac beat as a method of research of the heart's memory (first communication).

The AA. have studied the heart's memory by autocorrelation function of heart beats in healthy. The results have demonstrated that there is positive or negative correlation in the space of the first 25-35 pulsation which follow pulsation chosen at random.

Variability in the arterial pressure of newborns as compared to that of adults and old men.

The systolic and diastolic blood pressure was monitored on healthy subjects of different ages, spanning from newborns (24-48 hs old, to elderly age (70-80 years old). Each subject was monitored for 15 minutes, and the pressure values collected every minute. This protocol allowed a statistical evaluation of both inter- and intraindividual variabilities among and within different class ages. As expected, increasing age is paralleled by a marked increase in the average values of systolic blood pressure; the trend of variabilities around the average, however, as traced by standard deviations, is just the opposite: a marked decrease going from newborns to adults is accompanied--in most cases--by a statistically significant difference in the same direction also between adults and old men. This can be rationalized, in the light of recent findings on the role of deterministic chaos in the functional behaviour of complex biological systems, in terms of decreased functional flexibility characteristic of the aging process.

[Individual arterial pressure variability in newborn infants, adults, and the elderly]. / Osservazioni sulla variabilità individuale della pressione arteriosa in neonati, adulti e anziani.

The complexity of the cardiovascular function is related to a wide interindividual variability (VA) that changes with age. The aim of our study was to investigate the spontaneous blood pressure (BP) VA in 3 groups of 20 healthy subjects (S) each, 10 M and 10 F: Group I newborns 24 hours old; Group II 30-40 yrs; Group III 70-80 yrs. Each S underwent BP monitoring in a comfortable condition for 15'. Our data show an increase, with age, of both the average systolic and diastolic BP, paralleled by a simultaneous decrease of their standard deviations. Furthermore, the three distributions show a reasonably gaussian behaviour (maximum absolute value of the skewness was 0.21). These results emphasize the age-dependent reduction in functional flexibility of the cardiovascular system. A major pool of subjects is required to confirm our preliminary data.

[New horizons in medicine. The application of "fuzzy logic" in clinical and experimental medicine]. / Nuovi orizzonti in medicina. Sulla applicazione della "logica sfumata" in medicina clinica e sperimentale.

In medicine, the study of physiological and physiopathological problems is generally programmed by elaborating models which respond to the principals of formal logic. This gives the advantage of favouring the transformation of the formal model into a mathematical model of reference which responds to the principles of the set theories. All this is in the utopian wish to obtain as a result of each research, a net answer whether positive or negative, according to the Aristotelian principal of tertium non datur. Taking this into consideration, the A. briefly traces the principles of modal logic and, in particular, those of fuzzy logic, proposing that the latter substitute the actual definition of "logic with more truth values", with that perhaps more pertinent of "logic of conditioned possibilities". After a brief synthesis on the state of the art on the application of fuzzy logic, the A. reports an example of graphic expression of fuzzy logic by demonstrating how the basic glycemic data (expressed by the vectors magnitude) revealed in a sample of healthy individuals, constituted on the whole an unbroken continuous stream of set partials. The A. calls attention to fuzzy logic as a useful instrument to elaborate in a new way the analysis of scenario qualified to acquire the necessary information to single out the critical points which characterize the potential development of any biological phenomenon.

[New horizons in medicine. Aging and the laws of modern physics]. / Nuovi orizzonti in medicina. L'invecchiamento e le leggi della fisica moderna.

Even today the problem of aging is not well known. The latest discoveries on the arrow of time, the theory of complexity, the identification of dissipative stationary structures in "non equilibrium", the observation that deterministic systems with a complex structure may produce chaos (which today we have begun to identify, with evident contradictions, laws and principles: the laws of disorder), are the new laws by which it will be possible to understand the evolution along the time of automatic control feed-back of homeostasis and so the progression of senescence. The attention is pointed particularly to three magnitudes of modern physics: dynamic stability, dissipative structures and entropy. In aging the structures of automatic control systems are submitted to a greater functional effort with the results of a reduction of dynamic stability, an increase in dissipative phenomena and entropy. Moreover the functional exhaustion of homeostatic systems (the linearization of the system) is not compatible with life unless a substitute system takes on its function. In this condition the possibility of survival of the living subjects is conditioned to the capacity of the vicarial system of having a higher state of "non equilibrium" at disposal and therefore of a higher dissipative capacity. From the valuation of dynamic stability, dissipative structures and entropy, it appears possible in a near future to clarify many aspects of the nature and dynamics of aging.

[New horizons in medicine. Complexity and predictability in internal medicine]. / Nuovi orizzonti in Medicina. Complessità e predicibilità in Medicina Interna.

Being a highly sophisticated structure, the human body should be considered on a physical level as a whole of inter-correlated non-linear dynamic systems, which are by definition, complex systems because they are always conditioned in their operativity by numerous variables. We must draw attention to the opportunity that within the field of medical science the concept of complexity referring to diagnostic, therapeutic and prognostical problems, is distinct between structural and functional. The functional complexity of a system, a phenomena, an event, MY be recognized in its dynamics, only if analysed using modern methods recently brought to light, on the relationship which exist between classic determinism and deterministic chaos. Furthermore, also on practical level, the recent discoveries on the general principles, which are at the base of the functional complexity of non-linear dynamic systems, demonstrate exactly how fragile is the probabilistic predictability which guides a doctor in clinical reasoning in all its various stages; in the gathering of anamnestic and objective data; in the programming the researches aimed at confirming the validness of the diagnosis; in the therapy aimed at reaching the best possible results; in the prognosis which summarize the destiny of the binomial patient illness. The scientific enunciate of universal nature, which demonstrate how, from a tiny uncertainty in the initial functional data of a system, of a phenomena, of an event can unleash a condition of absolute unpredictability, find daily confirmation in both clinical and experimental medicine.(ABSTRACT TRUNCATED AT 250 WORDS)

[New horizons in medicine. The attractors]. / Nuovi orizzonti in medicina. Gli attrattori.

The discovery of the fact that chaotic systems can suddenly coagulate into deterministic systems, and that deterministic systems can precipitate into chaotic systems has, on the one hand, clearly revealed the limits of the Cartesian geometrization of random phenomena, and on the other, has made in possible to identify the attractor as the reference entity when studying the functional dynamics of biological systems. The attractors is identified as the point of equilibrium upon which the behaviour of a dynamic system stabilizes and towards which it is constantly attracted. In some systems the attractor is identified as an "ideal" optimum reference point termed "the point". In other systems, however, the attractor is identified as a closed curve: "the ultimate cycle". Lastly, in other systems the attractor is identified as a surface in which the space of the states delimits a flat doughnut-shaped image constituting a "torus". The recent discovery of the laws governing deterministic chaos has made it possible to identify a new type of attractor termed the "strange attractor". This attractor has a fractal dimension (i.e. one midway between linear and plane), is of finite dimension and depends on the initial condition of the system. In many biological functions it is now possible to demonstrate the presence of attractors that operate starting from different initial conditions or that vary with time or that display both these conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

[New horizons in medicine. Fractals]. / Nuovi orizzonti in medicina. I frattali.

In these last few years, a vertiginous growth in the application of informatics in the field of science has generated a new branch of geometry: the geometry of irregularity whose paradigmatical expression is fractals. We can identify in the fractal an object of complex structure which, when gradually enlarged, shows up details which repeat themselves as the scale of enlargement is progressively run through. It is possible, therefore, by using fractals to study and quantify in a much more concise way and much less approximatively those structures which were until recently described as granulous, tentacular, ramified, etc. Fractals bridge the gap between mathematics and visual art and allow us to explore the rapport between determinism and apparent chaos in the study of non-linear biological systems. Fractal dimension is an intermediary one between linear and surface dimensions. The applications of fractals images in the study of certain problematics which concern the cardiovascular system are referred to synthetically; particularly those concerning the sectorial differences of myocardial blood flow and the branches of small coronary vessels, both in physiological and pathological conditions. Fractal images permit us to analyse the regional flow of the pulmonary parenchyma, and to quantify pulmonary damage from thromboembolism. Other applications of fractal studies regard the digestive system, the nervous system and mammary pathology. In specialistic fields, fractals have been studied in both ophthalmology and odontology, and also in biochemistry to study protein surfaces and fluids turbulence.

[New horizons in medicine. Chaos and its laws]. / Nuovi orizzonti in Medicina. Il caos e le sue leggi.

We have synthesized the fundamentals that modern technology offers in all areas of research, especially in the field of biomedicine. The theory of systems, cybernetics, synergetics, boolean algebra, communication science (according to modern laws of signal transmission and translation), the solution of non-linear equations by computer science, applied principles of reduction in biological survey, fractal analysis as a representation of dynamic, chaotic, non-linear systems, defined attractors as conditioning elements of biologic function, are just a few of the many instruments that modern science offers as a revolutionary approach to research programming. Borrowing the laws of mathematics, we have defined the fundamental characteristics of linear and non-linear homeostatic systems along with the concept of predictable behavior of a system as a function of its complex structure. Lastly, we have documented, based on personal research and recent findings in biomathematics, and despite current and strong opposition, how the functional death of any dynamic system is identified by the system's absolute state of equilibrium. The operative errors at times caused by different stimuli acting on specific organs and apparatus, are interpreted not as an index of altered function but as an expression of a chaotic response of the deterministic type and therefore an indication of the system's adaptability to the specific functional requirements in that precise moment.

The application of the theory of systems in internal medicine. State of the art and perspectives.

The application and contribution of Cartesian methodology to the development of medicine in physiology, pathophysiology and therapy have been overwhelming. The accumulation of knowledge over the last 3 centuries in scientific research is largely attributed to Cartesian methodology. This method, which in the past was used for the acquisition of nosological data is no longer sufficient for the interpretation of complex phenomena which modern science nowadays requires. The solution to these complex problems is only possible by means of the application of the theory of systems especially for the functional evaluation of biological feedback.