Kinds Of Devices Research Articles

High-Current Switched Capacitor Converter for On-Package VR With PDN Impedance Modeling

Digital ASIC devices are widely used in networking and computing applications. This kind of devices is implemented with a short-channel technology requiring high peak currents for high complexity systems and a low supply voltage. Digital ASICs are powered by an external voltage regulator with specifications similar to modern microprocessors’ power supply [voltage regulation modules (VRMs)]. In order to reduce the number of power pins and to reduce the power distribution network (PDN) issue, Intel’s Fourth-Generation Core integrates the voltage regulators. Moreover, many on-package conversion systems are present in the literature. In this article, a conversion solution based on a switched resonant tank is presented, yielding currents up to 300 A at 0.8 V, in an area of 10 cm2, with a resonant-driving technique. The novel converter is used to validate a new linear time-periodic (LTP) system modeling approach that can be applied to generic switched topologies; this contribution yields a mathematical description of the conversion chain, in particular enabling the precise calculation of the output impedance when a switched topology is used as the last stage.

Cultura digital y cambio institucional de las universidades

Con la llegada y el posterior arraigo de una cultura digital en las instituciones de educación superior, las comunidades académicas se modificaron. Sus rutinas, formas de gestión, maneras de interactuar y de relacionarse con otros miembros de la comunidad, de investigar, de dar y de tomar clases o de acceder a la información en todos los casos, se vieron permeados por lo digital. Pero esto no sólo se da de forma superficial en la universidad, como se suele dar en otros niveles educativos; la profundidad con la que llega a los campos disciplinarios, que es distinta pero notoria en cada caso, es elemental para integrar las Tecnologías de la Información y de la Comunicación en los planes y programas universitarios. De acuerdo con los resultados de investigación, la cultura de lo digital en áreas de alta especialización procuradas en la Universidad se refleja en los dispositivos que utilizan los universitarios, los programas informáticos para la manipulación de datos y simulación o las revistas digitales y bases de datos de prestigio y de alta valoración, además de en las formas en que la comunidad académica de una disciplina dada interactúa con estos artefactos digitales, los valora y pone en juego para mejorar sus prácticas disciplinarias y atender una serie de necesidades propias de su campo.

Work Function Lowering of Graphite by Sequential Surface Modifications: Nitrogen and Hydrogen Plasma Treatment.

Graphite-related materials play an important role in various kinds of devices and catalysts. Controlling the properties of such materials is of great significance to widen the potential applications and improve the performance of such applications as field emission devices and catalyst for fuel cells. In particular, the work function strongly affects the performance, and thus development of methods to tune the work function widely is urgently required. Here, we achieved wide-range control of the work function of graphite by nitrogen and hydrogen plasma treatments. The time of hydrogen plasma treatment and the amount of nitrogen atoms doped beforehand could control the work function of graphite from 2.9 to 5.0 eV. The formation of a surface dipole layer and the nitrogen-derived electron donation contributed to such lowering of the work function, which is advantageous for applications in various fields.

VENOUS ACCESS DEVICE RELATED COMPLICATIONS IN ONCOLOGIC PATIENTS ENROLLED ON HOME PARENTERAL NUTRITION

Oncologic patients with important anorexia or alterated digestive tract function, for obstruction or malabsorption, may benefit by Home Parenteral Nutrition. Aim: to evaluate the incidence of venous access related complications in cancer patients undergoing HPN. We included 195 patients enrolled on HPNon the basis of ESPEN guidelines, in 2015- 2016. Incidence of complications were expressed as events per 1000 HPN days, calculated from the HPN start date until the discontinuation of home infusions or the removal of the VAD or the death of the patient. The VADs used were peripherally inserted central catheters (PICCs), subcutaneous implanted port, tunneled central catheters (TCCs) or non tunneled central catheters (NTCCs). 111 males, 84 females; median age 65 years(27-94). Median HPN duration was 106 days. A total of 208 VADs were studied: 67% PICCs, 21% ports, 9% TCCs and 3% NTCCs. Both thrombosis and tip migrations occurred only in PICCs, while infections happened in PICCs, ports and TCCs. The overall incidence of VAD related complications per 1000 HPN days was 0,73(0,27 in TCCs, 0,70 in PICCs, 1,25 in ports and null in NTCCs). HPN results to be a supportive therapy with low rate of VADs related complications. Infections are the most frequent complication and may occur in all kind of devices. Cotogni P. Catheter-related complications in cancer patients on home parenteral nutrition: a prospective study of over 51,000 catheter days. JPEN J Parenter Enteral Nutr. 2013;37(3):375-83 Vashi PG. A longitudinal study investigating quality of life and nutritional outcomes in advanced cancer patients receiving home parenteral nutrition.BMC Cancer.2014;14:593

Photo- and Redox-Driven Artificial Molecular Motors.

Directed motion at the nanoscale is a central attribute of life, and chemically driven motor proteins are nature's choice to accomplish it. Motivated and inspired by such bionanodevices, in the past few decades chemists have developed artificial prototypes of molecular motors, namely, multicomponent synthetic species that exhibit directionally controlled, stimuli-induced movements of their parts. In this context, photonic and redox stimuli represent highly appealing modes of activation, particularly from a technological viewpoint. Here we describe the evolution of the field of photo- and redox-driven artificial molecular motors, and we provide a comprehensive review of the work published in the past 5 years. After an analysis of the general principles that govern controlled and directed movement at the molecular scale, we describe the fundamental photochemical and redox processes that can enable its realization. The main classes of light- and redox-driven molecular motors are illustrated, with a particular focus on recent designs, and a thorough description of the functions performed by these kinds of devices according to literature reports is presented. Limitations, challenges, and future perspectives of the field are critically discussed.

Experimental analysis of open check dams and protection bars against debris flows and driftwood

The paper addresses the influence of intense sediment transport (bed load and debris flow) on the efficiency of the structures aimed at the interception of wood logs. In the literature different devices designed to intercept woods are proposed: steel barriers, net barriers, check dam with steel bars positioned in the opening. In this paper we firstly define some fundamental dimensionless parameter governing the phenomenon, in order to determine a rational criterion to evaluate the efficiency of the different kind of devices. In particular, we deepen the interaction between slit check dams and driftwood, in both bed load and debris flow conditions. Starting from the results of this first analysis, we propose some arrangements of steel bars be installed in the check dam. Through a laboratory experimental investigation, by now conduced in simplified conditions (i.e. spherical mono-dispersed sediments), we define some criteria to obtain the best design parameters for the bars, that is their optimal disposition and spacing, in function of the logs characteristics (mainly the lengths). We investigate also the influence of different lengths of the transported woods, finding a general criterion to evaluate an overall length representing the logs ensemble.

On the challenges novice programmers experience in developing IoT systems: A Survey

The co-existence of various kinds of devices, protocols, architectures, and applications make Internet of Things (IoT) systems complex to develop, even for experienced programmers. When novice programmers are learning to implement these systems, they are required to deal with areas in which they do not have a deep knowledge. Furthermore, besides becoming proficient in these areas separately, they should integrate them and build a system whose components are heterogeneous from both software and hardware perspectives.The accurate understanding of the most challenging issues that novices face is fundamental to envision strategies aimed at easing the development of IoT systems. This paper focuses on identifying such issues in terms of software development tasks that novice programmers encounter when working on IoT systems. To this end, a survey was conducted among 40 novice developers that worked in groups developing IoT systems during several years of a university course. Based on their own experiences, individually and as a group, the most challenging development tasks were identified and prioritized over a common architecture, in terms of difficulty level and efforts. In addition, qualitative data about the causes of these issues was collected and analyzed. Finally, the paper offers critical insights and points out possible future work.

Influence of thermal boundary conditions on local convective heat transfer in coiled tubes

Helical coil heat exchangers are commonly used in a wide variety of engineering applications because, due to curvature of the tube that generates secondary flows, this kind of geometry can generate an enhancement of the convective heat transfer coefficient. Since the distributions of the fluid velocity and temperature in coiled pipes are strongly asymmetrical over the cross-section of the tube, particularly in laminar flow conditions, it is important to monitor the local heat transfer phenomena, mainly with regard to the applications where the local behaviour plays a leading role, such as in food industry. Indeed, due to the high viscosity of fluid foods or to the low velocity in which they may operate, the flow regime is often laminar in this kind of devices. In laminar flow regime, the thermal boundary conditions considerably affect the convective heat transfer performance. In the present paper, a numerical investigation focused on the evaluation of the effect of the choice of the thermal boundary condition on the local heat transfer phenomena in coiled-tubes, within the laminar regime, is presented. To cover realistic configurations in which the helical coil heat exchangers are commonly used, the conjugate heat transfer problem in the tube was also considered. The momentum and energy equations were solved by means of the open-source CFD software OpenFOAM®, with second-order accurate finite-volume schemes. The here adopted numerical model was validated by comparing the results with local experimental data. The numerical outcomes, obtained for several values of the Prandtl number, revealed that the thermal boundary conditions could significantly change the local distribution of the convective heat transfer coefficient. Finally, the influence of the thermal boundary condition on the average convective heat transfer coefficient were evaluated by considering the two definitions of the circumferentially averaged Nusselt number commonly used in literature.

Las publicaciones de los museos sobre sus colecciones. El caso “ediciones digitales”del Museo Castagnino+macro

Los museos producen mensajes para legitimar y desarrollar un relato sobre su colección a través de sus espacios expositivos, actividades educativas, eventos masivos, publicaciones, entre otras opciones. En la actualidad, las piezas gráficas o editoriales se convierten en herramientas que permiten acercarse a las prácticas comunicacionales que operan en este tipo de institución cultural. Por ello, el presente trabajo tiene por objetivo desentrañar algunas transformaciones que se producen en este tipo de dispositivo en el modelo museístico contemporáneo.Esta exploración articula enfoques teóricos críticos museológicos y estudios de lo comunicacional. En este entrecruzamiento se busca, primeramente, trabajar el uso de este tipo de dispositivos, luego, definir algunos rasgos significativos que cobran las publicaciones en la actualidad a partir de los cruces entre comercial-experiencia-TIC, para confluir en un posible ejemplo de este tipo de propuesta llevada adelante por el museo argentino Castagnino+macro.

Characterization of variable inductors using finite element analysis

The variable inductor (VI) uses a small DC current to regulate the permeability of magnetic cores. Nonetheless, this magnetic device is composed of magnetic cores and multiple windings, which leads to a more complex geometry. Its magnetic properties variations and non-linear behavior complicate its modeling, analysis and its characterization. This paper uses Finite Element Analysis tool MagNet Infolytica software to characterize the VI in order to verify its feasibility for DC–DC converters with wide range of load variations. The inductance characterization, the losses and improvements in the saturation level are used to quantify the capability of the VI. The characterization and analysis presented in this paper will be a good base for researchers and designers to integrate the VI in converters and help them in choosing suitable VI configurations for their application. Moreover, the theoretical aspects presented in this paper will be essential for development of analytical ways for the characterization of such kind of devices. The inductance characterization obtained from FEM simulations agree with the experimental values with a mean squared error of 1.6%. Furthermore, for a current of more than twice the rated current, the differential inductance is increased by 56 times with control current in the auxiliary winding. This reveals the potential significance of VI in improving the current handling capability and core utilization leading to core size reduction in power electronic converters.

Standards-based semantic integration of manufacturing information: Past, present, and future

Service-oriented architecture (SOA) has been identified as a key to enabling the emerging manufacturing paradigms such as smart manufacturing, Industrie 4.0, and cloud manufacturing where things (i.e., various kinds of devices and software systems) from heterogeneous sources have to be dynamically connected. Data exchange standards are playing an increasingly important role to reduce risks associated with investments in these Industrial Internet of Things (IIoT) and adoptions of those emerging manufacturing paradigms. This paper looks back into the history of the standards for carrying the semantics of data across systems (or things), how they are developed, maintained, and represented, and then presents an insight into the current trends. In particular, the paper discusses the emerging move in data exchange standards practices toward model-based development and usage. We present functional requirements for a system supporting the model-based approach and conclude with implications and future directions.

Estudio del comportamiento de sensores de gas basados en resonadores de cristal de cuarzo para altas frecuencias

Quartz crystal microbalance (QCM) sensors have been frequently used as micro-weighing devices, since they have demonstrated to be highly sensitive due to the frequency shifts ought to mass- increments stuck on the sensing film surface of the sensor. This kind of devices are normally used as arrays of sensors in systems known as Electronic Noses, for the detection and analysis of gases, fluids, and biological compounds among others. The sensitivity of the QCM sensors is directly proportional to the resonance frequency of the crystal. Therefore, increasing sensitivity implies using high frequency crystals above 20 MHz. Quartz crystals have been manufactured in two modalities: fundamental and overtone, the latter being used for frequencies between 30 MHz and 200 MHz. In this work, we present theoretical arguments as well as experimental results that describe the characteristics and differences in the performance of 30 MHz sensors in both modalities, in addition to other considerations in the behavior of these devices that cannot be observed from the analytical point of view, but from the point of experimental view.

A Novel Device Identification Method Based on Passive Measurement

Nowadays, with the continuous integration of production network and business network, more and more Industrial Internet of Things and Internal Office Network have been interconnected and evolved into a large-scale enterprise-level intraindustry network. Terminal devices are the basic units of internal network. Accurate identification of the type of device corresponding to the IP address and detailed description of the communication behavior of the device are of great significance for conducting network security risk assessment, hidden danger investigation, and threat warning. Traditional cyberspace surveying and mapping techniques take the form of active measurement, but they cannot be transplanted to large-scale intranet. Resources or specific targets in internal networks are often protected by firewalls, VPNs, gateways, and other technologies, so they are difficult to analyze and determine by active measurement. In this paper, a passive measurement method is proposed to identify and characterize devices in the network through real traffic data. Firstly, a new graph structure mining method is used to determine the server-like devices and host-like devices; then, the NAT-like devices are determined by quantitative analysis of traffic; finally, by qualitative analysis of the NAT-like device traffic, it is determined whether there are server-like devices behind the NAT-like device. This method will prove to be useful in identifying all kinds of devices in network data traffic, detecting unauthorized NAT-like devices and whether there are server-like devices behind the NAT-like devices.

Stretchable electrochromic devices enabled via shape memory alloy composites (SMAC) for dynamic camouflage

Electrochromic device is a kind of device that can produce color change under the actuation of electric signal. It has attracted wide attention because of its dynamic color change properties, color diversity and convenience of driving signals. These properties highlight its potential application prospects in dynamic display, anti-counterfeiting treatment, biomedicine and other fields. In this study, stretchable photonic crystals are prepared by nano-imprint technology, soft actuators made by shape memory alloy composites (SMAC) were developed based on shape memory alloy (SMA). A stretchable electrochromic device is obtained by integrating the stretchable photonic crystal and SMAC. The electrochromic properties of the device is tested under different voltages. It is found that under the voltage of 1.0 V–1.5 V, it can achieve color changing in entire visible light range, and the total deformation required is less than 30%. The properties of stretchable electrochromic devices based on SMAC is comparative analyzed with that of other electrochromic devices or structures. The results show that the proposed stretchable electrochromic device has the characteristics of low driving voltage, good compliance, wide color changing range, short response time and large effective color changing area. Finally, the excellent soft dynamic display and camouflage functions of stretchable electrochromic devices are demonstrated in a special pattern, and the high impact resistance of the device is verified. The results indicates that the proposed structure is a promising stretchable electrochromic device, which may have great potential for applications of chameleon-like camouflage functional materials and devices.

The AM4I Architecture and Framework for Multimodal Interaction and Its Application to Smart Environments.

Technologies, such as smart sensors, actuators, and other kinds of devices, are often installed in our environments (e.g., our Homes) and available to integrate our daily lives. Despite their installation being motivated by the pursuit of automation and increased efficiency, making these environments usable, acceptable and enjoyable in a sustainable, energy efficient way is not only a matter of automation. Tackling these goals is a complex task demanding the combination of different perspectives including building and urban Architecture, Ubiquitous Computing and Human-Computer Interaction (HCI) to provide occupants with the means to shape these environments to their needs. Interaction is of paramount relevance in the creation of adequate relations of users with their environments, but it cannot be seen independently from the ubiquitous sensing and computing or the environment’s architecture. In this regard, there are several challenges to HCI, particularly in how to integrate this multidisciplinary effort. Although there are several solutions to address some of these challenges, the complexity and dynamic nature of the smart environments and the diversity of technologies involved still present many challenges, particularly for its development. In general, the development is complex, and it is hard to create a dynamic environment providing versatile and adaptive forms of interaction. To participate in the multidisciplinary effort, the development of interaction must be supported by tools capable of facilitating co-design by multidisciplinary teams. In this article, we address the development of interaction for complex smart environments and propose the AM4I architecture and framework, a novel modular approach to design and develop adaptive multiplatform multilingual multi-device multimodal interactive systems. The potential of the framework is demonstrated by proof-of-concept applications in two different smart environment contexts, non-residential buildings and smart homes.

Easyhaler®: an overview of an inhaler device for day-to-day use in patients with asthma and chronic obstructive pulmonary disease

Inhalation therapy is likely to continue to dominate asthma and chronic obstructive pulmonary disease (COPD) treatment. The pressurised metered-dose inhaler (pMDI) accounts for most of the global inhaler market, but this kind of device is difficult to use properly. Dry powder inhalers (DPIs) have several advantages over pMDIs: they are breath-activated, easy and convenient to use, and environmentally friendly. The Easyhaler® (Orion; Finland) is a multidose reservoir-type DPI developed to efficiently deliver a wide range of medications, including fixed-dose combinations of bronchodilators and corticosteroids. Easyhaler shares a similar shape with the pMDI, and its performance is unaffected by moisture, dropping, vibration, and freezing/thawing. For these reasons, Easyhaler may be considered one of the most convenient inhalers for daily use in patients with asthma or COPD.

Quasi One-Dimensional Metal-Semiconductor Heterostructures.

The band offsets occurring at the abrupt heterointerfaces of suitable material combinations offer a powerful design tool for high performance or even new kinds of devices. Because of a large variety of applications for metal-semiconductor heterostructures and the promise of low-dimensional systems to present exceptional device characteristics, nanowire heterostructures gained particular interest over the past decade. However, compared to those achieved by mature two-dimensional processing techniques, quasi one-dimensional (1D) heterostructures often suffer from low interface and crystalline quality. For the GaAs-Au system, we demonstrate exemplarily a new approach to generate epitaxial and single crystalline metal-semiconductor nanowire heterostructures with atomically sharp interfaces using standard semiconductor processing techniques. Spatially resolved Raman measurements exclude any significant strain at the lattice mismatched metal-semiconductor heterojunction. On the basis of experimental results and simulation work, a novel self-assembled mechanism is demonstrated which yields one-step reconfiguration of a semiconductor-metal core-shell nanowire to a quasi 1D axially stacked heterostructure via flash lamp annealing. Transmission electron microscopy imaging and electrical characterization confirm the high interface quality resulting in the lowest Schottky barrier for the GaAs-Au system reported to date. Without limiting the generality, this novel approach will open up new opportunities in the syntheses of other metal-semiconductor nanowire heterostructures and thus facilitate the research of high-quality interfaces in metal-semiconductor nanocontacts.

Radiation Protection Design and Licensing for an Experimental Fusion Facility: The Italian and European Approaches

An experimental nuclear fusion device could be seen as a step toward the development of the future nuclear fusion power plant. If compared with other possible solutions to the energy problem, nuclear fusion has advantages that ensure sustainability and security. In particular, considering the radioactivity and the radioactive waste produced in a nuclear fusion plant, the component materials for the plant could be selected in order to limit the decay period, making recycling possible in a new reactor after about 100 yr from the beginning of decommissioning. To achieve this and other pertinent goals, many experimental machines have been developed and operated worldwide in the last decades, underlining that radiation protection and worker exposure are critical aspects of these facilities due to the high-flux, high-energy neutrons produced in the fusion reactions. Direct radiation, material activation, tritium diffusion, and other related issues pose a real challenge to demonstrating that these devices are safer than nuclear fission facilities. In Italy, for the past 30 yr, a limited number of fusion facilities have been constructed and operated, mainly at the ENEA Frascati Center, where a new one, the Italian Divertor Tokamak Test Facility (DTT), is now under development. The radiation protection approach, addressed by national licensing requirements, shows that respecting the constraints for worker exposure to ionizing radiation is not always straightforward. In the current analysis the main radiation protection issues encountered in the Italian fusion facilities are considered and discussed, and the technical and legal requirements are described. The licensing process for this kind of device is outlined and compared with that of other European countries.The following aspects are considered throughout the current study: description of the installation, plant, and systems; suitability of the area; buildings and structures; radioprotection structures and organization; exposure of personnel; accident analysis and relevant radiological consequences; and radioactive waste assessment and management.In conclusion, the analysis points out the need for special attention to the radiological exposure of workers in order to demonstrate at least the same level of safety as that reached at nuclear fission facilities.

Kablosuz Uzaktan Kontrol İçin Platform Geliştirilmesi

In this study, a platform to develop remote control appliactions via bluetooth communication by using general purpose microcontroller boards and Adroid-based devices was designed. This system was designed to integrate easily into all kind of devices that was developed by students or manufacturers in especially biomedical area. In addition, it has an Android application. It is possible to transmit control statements wirelessly from a microcontroller board or an Android-based device to another microcontroller board via bluetooth. On the client-side board, there are PWM-driven led illumination control, servo motor control and four on-off relay controls. The implemented system is designed to use easily for educational purposes. Time saving from sofware design applications is aimed in this study.

(Invited) Graphene Based Devices for in Vitro and In Vivo Electrophysiology

In the field of electrophysiology, graphene has just recently gained impact in cellular interfacing. Compared to silicon-based transistors, they are more sensitive, hence more favorable. Moreover, intrinsic flexibility and biocompatibility of graphene has a promising future for this research, pointing out in the direction of fully flexible, soft and implantable neuroprosthetic applications. There, graphene can be used either actively as a transistor's active area or passively as an electrode material. In the first case, the device requires at least two electrodes (source and drain), complicated electrochemical gating, and read-out schematics while in the second case there is just one feedline required to feed and record from a graphene electrode. Moreover, such graphene-based electrodes are comparably easy to fabricate, characterize and use. In this presentation, we will describe a method to fabricate arrays of graphene-based probes, requiring minimal number of fabrication steps, while maintaining overall device functionality. These devices are either fabricated on rigid or flexible substrates. Devices, such as graphene field effect transistors (GFETs) and graphene multielectrode arrays (GMEAs) have been designed, fabricated and tested for their performance. The flexible GFETs exhibit an order of magnitude larger sensitivity compared to silicon transistors with similar geometry. Multiple probe per wafer design allows us to fabricate different kinds of devices on one 4-inch wafer, consequently increasing a possible range of applications from e.g. retinal to cortical neuroprosthetics.