Evaluation of acrylamide formation in potatoes during deep-frying: The effect of operation and configuration

It is nowadays well known that heating, which is carried out to improve the hygienic, sensory and nutritional properties of foods, can be also responsible for the development of acrylamide. Acrylamide levels between a few ppb and in excess of 1000 ppb have been found in many heated foods. As acrylamide is classified as a probable human carcinogen, the knowledge of critical processing variables leading to its formation is needed to ensure safety requirements.     

Response of self-compacting concrete filled tubes under eccentric compression

Self-Compacting Concrete (SCC) use is spreading worldwide and it is becoming a regular solution in some special applications, including steel-concrete composite columns. In the particular case of Concrete Filled Tubes (CFT), the main advantage from a practical point of view in the use of SCC consists in employing the steel tube as a formwork to directly cast concrete inside it, without the need of vibration. The study of three different concretes for structural applications as composite elements is presented, each of them designed for a 28-day cylindrical compressive strength of 50 MPa: (i) a Normal Vibrated Concrete, (ii) a Self-Compacting Concrete, (iii) an expansive SCC (with the goal of an increase in bond strength as a consequence of the expansion).CFT with critical length ranging from 131 cm to 467 cm have been experimentally and analytically investigated in uniaxial compression. In each case the steel case presents a cross section of 139.6 mm of external diameter and 4.0 mm thickness and with a fixed eccentricity of the applied load equal to 25 mm. The bond strength at the steel-concrete interface is reported for each of the three mixes.The experimental and analytical results show that the behavior of eccentrically loaded columns is governed by the bending moment-axial load interaction. As a consequence, perfect bond at the interface can be assumed and the axial capacity of the column is only a function of its geometry and of the mechanical properties of the materials.A numerical procedure is proposed to evaluate the increase in the axial capacity of the composite columns consequent to the confinement of the internal concrete in case of zero-eccentricity of the applied axial load with respect to the column’s axis.Finally, the obtained numerical results are introduced into code provisions to evaluate modified axial force N-bending moment M interaction diagrams to predict the axial capacity of the column in the particular test configuration.     

High survival of frozen cells irradiated with gamma radiation

Cell storage in liquid nitrogen (LN) offers the most secure method of cell preservation even if cryopreserved cells are exposed to natural background of ionising radiation (IR). A lot of experiments have demonstrated that IR can induce damages in living cells, but only a little information regarding the response of cryopreserved cells is available. To investigate the effect of IR on frozen and unfrozen cells, peripheral blood mononuclear cells were directly irradiated at room temperature, then immediately frozen, or frozen and then irradiated in LN with different doses of gamma rays. After thawing, cells were incubated and death fraction was evaluated at different time points. Interestingly, the percentages of dead cells induced by IR gradually increased with both dose radiation and incubation time and were significantly lower for cells irradiated at -196°C than those irradiated at room temperature.     

Direct ink writing of silicone/filler mixtures for sphene scaffolds with advanced topologies

Pastes based on preceramic polymers have a great potential for direct ink writing of bioceramic scaffolds. In this paper, we discuss the fabrication of phase pure sphene (CaTiSiO₅) bioceramics, developed by firing, at 1300°C, of silicone-based printed scaffolds containing CaCO₃ and TiO₂ as active fillers. As a proof of the flexibility of the combination of preceramic polymers and additive manufacturing technologies, several lattice geometries of increasing complexity were successfully explored. In particular, the approach allowed the fabrication of sphene scaffolds with gyroid-like structure exhibiting an impressive compressive strength, given the high porosity. Moreover, different lattice topologies of sphene scaffolds were compared also in terms of permeability.     

A simple model to explain the effect of different boundary conditions in direct tensile tests

Experimental observations suggests that concrete specimens subjected to uniaxial tension may have different responses depending on the imposed kinematic “constrains”. A simple model is proposed here to explain the experimental findings. Concrete specimens are schematized as a system composed of three trusses. This model can thus consider the non-homogeneity of the material, and the eccentricity between the head of the testing machine and the specimen. Two kinds of tests are considered: imposed uniform displacement (fixed platens) and freely rotating platens. The results of the model show that the tests based on fixed platens provide higher peak loads. Only for a perfect specimen and testing conditions (homogeneous material and absence of geometric eccentricity) the results of a fixed platens test and of a rotating platens test coincide. Furthermore, the same results are obtained by energy balance.     

DSOL: a declarative approach to self-adaptive service orchestrations

Service oriented computing (SOC) has brought a simplification in the way distributed applications can be built. Mainstream approaches, however, failed to support dynamic, self-managed compositions that would empower even non-technical users to build their own orchestrations. Indeed, because of the changeable world in which they are embedded, service compositions must be able to adapt to changes that may happen at run-time. Unfortunately, mainstream SOC languages, like BPEL and BPMN, make it quite hard to develop such kind of self-adapting orchestrations. We claim that this is mostly due to the imperative programming paradigm they are based on. To overcome this limitation we propose a radically different, strongly declarative approach to model service orchestration, which is easier to use and results in more flexible and self-adapting orchestrations. An ad-hoc engine, leveraging well-known planning techniques, interprets such models to support dynamic service orchestration at run-time.     

Analytic Critical Flow Method (ACFM): A Reliability Allocation Method Based on Analytic Hierarchy Process

RAMS is an acronym for reliability, availability, maintainability and safety. These four properties concern the application of important methodologies to design and manage complex systems. In the present research, starting from the analysis of several literature reliability allocation techniques, a reliability allocation method has been implemented called analytic critical flow method (ACFM). Critical flow method is a reliability allocation method for series-parallel configurations, based on failure analysis of each unit of the system. The new approach is based on critical flow method, whose results are matched with the analytic hierarchy process multicriteria method. The result is a dynamic model that combines the advantages of the allocation method and the multicriteria approach. The need to develop the ACFM is the outcome of a careful analysis of the current military and commercial approaches. In particular, no literature method takes into account to assign a different level of significance (weight) to the different units of the system, simultaneously to the considered factors. The proposed approach has been applied and compared with other traditional methods on an aerospace prototype (series-parallel configuration), where the reliability allocation process is rigorous. The results demonstrate the effectiveness of the new approach and its ability to overcome the criticalities highlighted in literature.     

A surface roughness predictive model in deterministic polishing of ground glass moulds

The introduction of deterministic NC grinding and polishing operations, in the manufacturing of free-form glass components for precision optics, requires the characterization of surface topography evolution as a function of process parameters. In this work, a model based on Reye's wear hypothesis is proposed for the assessment of surface roughness prediction as a function of operating parameters, in the deterministic polishing process of glass moulds. According to Reye's hypothesis, the removed material per unit area is proportional to the work due to the friction force: the removed material per unit area can be computed by adequately integrating the areal material ratio function (Abbott–Firestone curve) of the surface and can be associated with the amplitude roughness parameter; the work due to the friction force per unit area is proportional to the integral of the product of pressure and velocity in the time interval and can be derived from the process parameters by means of the Hertz theory. The model assessment was performed on ground glass flat samples polished with different operating parameters, mapping the surface roughness using an atomic force microscope (AFM). The developed model shows a satisfactory estimate of surface roughness evolution during the polishing process and confirms the experimental results found in the literature for the Preston coefficient.     

Deployment strategies for distributed complex event processing

Several complex event processing (CEP) middleware solutions have been proposed in the past. They act by processing primitive events generated by sources, extracting new knowledge in the form of composite events, and delivering them to interested sinks. Event-based applications often involve a large number of sources and sinks, possibly dispersed over a wide geographical area. To better support these scenarios, the CEP middleware can be internally built around several, distributed processors, which cooperate to provide the processing and routing service. This paper introduces and compares different deployment strategies for a CEP middleware, which define (i) how the processing load is distributed over different processors and (ii) how these processors interact to produce the required results and to deliver them to sinks. Our evaluation compares the presented solutions and shows their benefits with respect to a centralized deployment, both in terms of network traffic and in terms of forwarding delay.