Extrusion with ultrasound applied on intumescent flame‐retardant polypropylene

In this work, the effect of processing conditions on the production of an intumescent flame‐retardant system is studied in polypropylene‐based compounds. Two distinct procedures were used: ultrasonic assisted single screw (with a static mixer die) and twin screw extrusion. The flame‐retardant, thermal, mechanical, morphological, and rheological properties were measured. It was found that the flame‐retardant intumescent content can be diminished from 30 phr (as usually used) to 21 phr using the application of ultrasonic waves during extrusion and with the addition of chemically modified clay to obtain a V0 classification according to UL94‐V standards. In addition, the processed materials presented improvements in the mechanical properties such as impact resistance (Izod Notched), strain at break and tenacity upon ultrasound application. The online application of ultrasound through a die that produces extensional flows improved greatly the dispersion and distribution of the particles of the intumescent system and the chemically modified clay in the polymer matrix. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

A 200-mA, 93% peak power efficiency, single-inductor, dual-output DC–DC buck converter

A single-inductor dual-output (SIDO) DC–DC buck converter is presented. The circuit uses only one (external) inductor to provide two independent output voltages ranging from 1.2 V to the power supply (2.6–5 V) with a maximum total output current of 200 mA. The proposed converter has been fabricated in a 0.35-μm p-substrate CMOS technology. Measurement results demonstrate that a peak power efficiency as high as 93.3% can be achieved. An automatic substrate bias switch technique, that cancels the body effect of the p-channel output power transistors, improves the converter power efficiency performance.     

Performance of control systems based on recycle compensators in integrated plants

The paper illustrates the effects of recycle streams on the controllability of integrated plants and the improvement of performance made possible by a direct compensation of the recycle. A procedure for the decomposition of the global process in a part representing the process without recycle and in a part representing the recycle is presented. This is the key issue for evaluating the relevance of the recycle and to reduce the control system to two blocks: a regulator, depending on the process without recycle, plus a recycle compensator. The design of this control scheme is much easier with respect to a specific regulator computed for the global process and allows to achieve relevant improvement of performance with respect to a standard PI regulator. This is clearly illustrated for a SISO reference case, where process parameters are changed to create situations of particular evidence, and have been confirmed in the application to the two MIMO benchmarks, proposed in literature: the two reactors in series (W.H. Ray, Advanced Process Control, McGraw–Hill, New York, 1981, pp. 219–224), and the two reactors plus three distillation columns (M.L. Luyben, W.L. Luyben, Design and control of a complex process involving two reaction steps, three distillation columns and two recycle streams, Ind. Eng. Chem. Res. 34 (1995) 3885–3898). For a full evaluation of the effectiveness of the proposed control system, the effect of the uncertainty, of the approximated structure of the compensator, as well as possible improvements by including partial adaptive features in the control system, are also taken into consideration.     

Starch and Starch Derivatives Industry in India

Tapioca and maize are the major sources of starch in India. Tapioca starch is produced in very small units which are not extensively mechanized. This quality of the starch produced is not of a high quality. Maize starch is produced in mechanized units. The liberalization of the economy and growing consumerism bode well for the starch industry in India. Growth of the starch industry would depend on developing applications for starch as well as optimizing usage to derive maximum benefits. The unique properties of maize and tapioca should be considered.     

An Efficient Aequorea victoria Green Fluorescent Protein for Stimulated Emission Depletion Super-Resolution Microscopy

In spite of their value as genetically encodable reporters for imaging in living systems, fluorescent proteins have been used sporadically for stimulated emission depletion (STED) super-resolution imaging, owing to their moderate photophysical resistance, which does not enable reaching resolutions as high as for synthetic dyes. By a rational approach combining steady-state and ultrafast spectroscopy with gated STED imaging in living and fixed cells, we here demonstrate that F99S/M153T/V163A GFP (c3GFP) represents an efficient genetic reporter for STED, on account of no excited state absorption at depletion wavelengths <600 nm and a long emission lifetime. This makes c3GFP a valuable alternative to more common, but less photostable, EGFP and YFP/Citrine mutants for STED imaging studies targeting the green-yellow region of the optical spectrum.     

A mediator-based approach for integrating heterogeneous multimedia sources

In many applications, the information required by the user cannot be found in just one source, but has to be retrieved from many varying sources. This is true not only of formatted data in database management systems, but also of textual documents and multimedia data, such as images and videos. We propose a mediator system that provides the end-user with a single query interface to an integrated view of multiple heterogeneous data sources. We exploit the capabilities of the MOMIS integration system and the MILOS multimedia data management system. Each multimedia source is managed by an instance of MILOS, in which a collection of multimedia records is made accessible by means of similarity searches employing the query-by-example paradigm. MOMIS provides an integrated virtual view of the underlying multimedia sources, thus offering unified multimedia access services. Two features are that MILOS is flexible—it is not tied to any particular similarity function—and the MOMIS’s mediator query processor only exploits the ranks of the local answers.     

Static analysis for discovering IoT vulnerabilities

The Open Web Application Security Project (OWASP), released the “OWASP Top 10 Internet of Things 2018” list of the high-priority security vulnerabilities for IoT systems. The diversity of these vulnerabilities poses a great challenge toward development of a robust solution for their detection and mitigation. In this paper, we discuss the relationship between these vulnerabilities and the ones listed by OWASP Top 10 (focused on Web applications rather than IoT systems), how these vulnerabilities can actually be exploited, and in which cases static analysis can help in preventing them. Then, we present an extension of an industrial analyzer (Julia) that already covers five out of the top seven vulnerabilities of OWASP Top 10, and we discuss which IoT Top 10 vulnerabilities might be detected by the existing analyses or their extension. The experimental results present the application of some existing Julia’s analyses and their extension to IoT systems, showing its effectiveness of the analysis of some representative case studies.

     

Directional Discretized Occluders for Accelerated Occlusion Culling

We present a technique for accelerating the rendering of high depth-complexity scenes. In a preprocessing stage, we approximate the input model with a hierarchical data structure and compute simple view-dependent polygonal occluders to replace the complex input geometry in subsequent visibility queries. When the user is inspecting and visualizing the input model, the computed occluders are used to avoid rendering geometry which cannot be seen. Our method has several advantages which allow it to perform conservative visibility queries efficiently and it does not require any special graphics hardware. The preprocessing step of our approach can also be used within the framework of other visibility culling methods which need to pre-select or pre-render occluders. In this paper, we describe our technique and its implementation in detail, and provide experimental evidence of its performance. In addition, we briefly discuss possible extensions of our algorithm.     

Building Decision Procedures for Modal Logics from Propositional Decision Procedures: The Case Study of Modal K(m)

The goal of this paper is to propose a new technique for developing decision procedures for propositional modal logics. The basic idea is that propositional modal decision procedures should be developed on top of propositional decision procedures. As a case study, we consider satisfiability in modal K(m), that is modal K with m modalities, and develop an algorithm, called K , on top of an implementation of the Davis–Putnam–Longemann–Loveland procedure. K is thoroughly tested and compared with various procedures and in particular with the state-of-the-art tableau-based system K . The experimental results show that K outperforms K and the other systems of orders of magnitude, highlight an intrinsic weakness of tableau-based decision procedures, and provide partial evidence of a phase transition phenomenon for K(m).