1,222 research outputs found
X-ray Imaging of Transplanar Liquid Transport Mechanisms in Single Layer Textiles
Understanding the
penetration of liquids within textile fibers
is critical for the development of next-generation smart textiles.
Despite substantial research on liquid penetration in the plane of
the textile, little is known about how the liquid penetrates in the
thickness direction. Here we report a time-resolved high-resolution
X-ray measurement of the motion of the liquidâair interface
within a single layer textile, as the liquid is transported across
the textile thickness following the deposition of a droplet. The measurement
of the time-dependent position of the liquid meniscus is made possible
by the use of ultrahigh viscosity liquids (dynamic viscosity from
10<sup>5</sup> to 2.5 Ă 10<sup>6</sup>Â times larger than
water). This approach enables imaging due to the slow penetration
kinetics. Imaging results suggest a three-stage penetration process
with each stage being associated with one of the three types of capillary
channels existing in the textile geometry, providing insights into
the effect of the textile structure on the path of the three-dimensional
liquid meniscus. One dimensional kinetics studies show that our data
for the transplanar penetration depth Î<i>x</i><sub>L</sub> vs time do not conform to a power law, and that the measured
rate of penetration for long times is smaller than that predicted
by LucasâWashburn kinetics, challenging commonly held assumptions
regarding the validity of power laws when applied to relatively thin
textiles
Towards biological control strategies for the bronze bug, Thaumastocoris peregrinus, on eucalyptus plantations in South America.
Edição dos abstracts do 24Âș IUFRO World Congress, 2014, Salt Lake City. Sustaining forests, sustaining people: the role of research
Boosting the Performance of PC-based Software Routers with FPGA-enhanced Network Interface Cards
The research community is devoting increasing attention to software routers based on off-the-shelf hardware and open-source operating systems running on the personalcomputer (PC) architecture. Today's high-end PCs are equipped with peripheral component interconnect (PCI) shared buses enabling them to easily fit into the multi-gigabit-per-second routing segment, for a price much lower than that of commercial routers. However, commercially-available PC network interface cards (NICs) lack programmability, and require not only packets to cross the PCI bus twice, but also to be processed in software by the operating system, strongly reducing the achievable forwarding rate. It is therefore interesting to explore the performance of customizable NICs based on field-programmable gate array (FPGA) logic devices we developed and assess how well they can overcome the limitations of today's commercially-available NIC
Sporadic flat ileal adenocarcinoma: an intriguing challenge in the comprehension of a rare neoplasia and its genesis. Case report and review of literature
Small bowel adenocarcinoma is a rare tumor, with a still not well studied tumorigenesis process, usually presenting in an advanced stage. The clinical diagnosis is often difficult; surgery is the treatment of choice when feasible, while the chemotherapic approach is still not well codified. We describe the case of a 71-yr-old male patient, presenting with an acute right abdomen. At laparotomy the terminal ileum appeared chronically inflamed and thickened. An ileocecal resection with laterolateral
ileocolic anastomosis was performed. The gross appearance resembled an inflammatory bowel disease, but microscopic examination revealed the extensive presence of an infiltrating ileal adenocarcinoma. Literature about small bowel adenocarcinoma has been reviewed for better understanding its pathogenesis
A multi-purpose control and power electronic architecture for active magnetic actuators
This paper shows the results related with the
design and implementation of a multi-purpose electronic
architecture used to drive magnetic actuators by means of a
three-phase independent-legs module in place of the
commonly used H-bridge modules. The typical application
is the magnetic actuators drive used in active magnetic
bearings. The architecture is composed of a control unit
with a floating point Digital Signal Processor (DSP), a
power board with six independent phase legs and a carrier
board to interconnect them. When more than one module is
required by the application, the communication between
them is guaranteed by means of CAN bus interconnection.
The proposed system allows to drive two pairs of opposite
electromagnets, such as those typically used to control active
magnetic bearings. The study is motivated by the
opportunity of reducing the amount of power and control
electronic components resulting in a more straightforward,
efficient and cost reduction design
Hysteresis-type electronic controlling device for fuel injectors and associated method
A hysteresis-type electronic controlling
device is provided for fuel injectors that
includes, but is not limited to a power
driving unit for driving the fuel injectors with
an electric signal, a control stage
connected to the power driving unit and a
sensing stage fed by the power driving unit
and feeding the control stage, the device
has a feedback frequency control stage for
measuring a waveform period of the signal
feeding the fuel injectors; the feedback
frequency control stage is fed by the control stage with an electric signal. A fuel injector
control method is also provided that includes, but is not limited to driving fuel injectors
with an electric signal coming from a power driving unit fed by a control stage , sensing
the signal with a sensing stage, and measuring a waveform period of the signal through
the feedback frequency control stage
Fault management in an i.c. engine piezoelectric fuel injection system
A piezoelectric injection system 15, eg for a diesel engine, comprises a VDCpower supply 24 for supplying a power circuit 17 provided with a DC-DC converter having high-side and low-side drivers 20, 21 connected at a switching node 22, the drivers being electrically connected to at least a piezoelectric injector 16. The value of an electric parameter representative of the operation the injection system is monitored and compared with a predetermined reference parameter value, and emergency means 32 are activated when the monitored parameter value exceeds the respective reference value. The electric parameter may be the current flowing through the piezoelectric actuator 19 and/or the low-side driver 21, sensed by current sensor 30, or the voltage across the piezoelectric actuator. The emergency means 32 may interrupt the operation of the drivers 20, 21, discharge the piezoelectric injector or disconnect the injector form the power circuit 1
Model and Design of a Power Driver for Piezoelectric Stack Actuators
A power driver has been developed to control piezoelectric stack actuators used in automotive application. An FEM model of the actuator has been implemented starting from experimental characterization of the stack and mechanical and piezoelectric parameters. Experimental results are reported to show a correct piezoelectric actuator driving method and the possibility to obtain a sensorless positioning control
Fault management in an i.c. engine piezoelectric fuel injection system
A piezoelectric injection system 15, eg for a
diesel engine, comprises a VDCpower
supply 24 for supplying a power circuit 17
provided with a DC-DC converter having
high-side and low-side drivers 20, 21
connected at a switching node 22, the
drivers being electrically connected to at
least a piezoelectric injector 16. The value
of an electric parameter representative of
the operation the injection system is
monitored and compared with a
predetermined reference parameter value,
and emergency means 32 are activated when the monitored parameter value exceeds
the respective reference value. The electric parameter may be the current flowing
through the piezoelectric actuator 19 and/or the low-side driver 21, sensed by current
sensor 30, or the voltage across the piezoelectric actuator. The emergency means 32
may interrupt the operation of the drivers 20, 21, discharge the piezoelectric injector or
disconnect the injector form the power circuit 17
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