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Possible Future Applications (possible + future_application)

Distribution by Scientific Domains

Medical Sciences	33%

Selected Abstracts

A New Pulsatile Volumetric Device With Biomorphic Valves for the In Vitro Study of the Cardiovascular System

ARTIFICIAL ORGANS, Issue 12 2009
Ettore Lanzarone
Abstract A pulsatile mock loop system was designed and tested. This prototype represents a versatile, adjustable, and controllable experimental apparatus for in vitro studies of devices meant to interface with the human circulatory system. The pumping system consisted of a ventricular chamber featuring two biomorphic silicone valves as the inlet and outlet valves. The chamber volume is forced by a piston pump moved by a computer-controlled, low-inertia motor. Fluid dynamic tests with the device were performed to simulate physiological conditions in terms of cardiac output (mean flow of 5 and 6 L/min, with beat rates from 60 to 80 bpm), of rheological properties of the processed fluid, and of systemic circulation impedance. The pulsating actuator performed a good replication of the physiological ventricular behavior and was able to guarantee easy control of the waveform parameters. Experimental pressure and flow tracings reliably simulated the physiological profiles, and no hemolytic subatmospheric pressures were revealed. The performance of the prototype valves was also studied in terms of dynamic and static backflow, effective orifice area, and pressure loss, resulting in their applicability for this device. Mechanical reliability was also tested over 8 h. The device proved to be a reliable lab apparatus for in vitro tests; the pumping system also represents a first step toward a possible future application of pulsating perfusion in the clinic arena, such as in short-term cardiac assist and pulsatile cardiopulmonary bypass. [source]

Glycerol upgrading by ketalization in a zeolite membrane reactor

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2009
Laura Roldán
Abstract Solketal, a valuable green solvent, has been produced from glycerol and acetone in a catalytic system, using K10 montmorillonite as a heterogeneous catalyst. The use of a zeolite membrane to remove water formed during the reaction gives rise to a significant improvement in the achievable glycerol conversion with a reduction in the excess of acetone needed because of the low equilibrium constant. Several zeolite membranes are compared, showing that the quality of the membrane is a key factor for this improvement, and that water/acetone separation is more difficult to achieve than the commonly used ethanol/water separation test. This method is compatible with a mixture of glycerol and fatty esters, showing the possible future application in an integrated system of biodiesel and solketal production. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]

Using natural 13C abundances to differentiate between three CO2 sources during incubation of a grassland soil amended with slurry and sugar

JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 6 2004
Yakov Kuzyakov
Abstract This study describes a novel approach to separate three soil carbon (C) sources by one tracer method (here 13C natural abundance). The approach uses the temporal dynamics of the CO2 efflux from a C3 grassland soil amended with added C3 or C4 slurry and/or C3 or C4 sugar to estimate contributions of three separate C sources (native soil, slurry, and sugar) to CO2 efflux. Soil with slurry and/or sugar was incubated under controlled conditions, and concentration and ,13C values of evolved CO2 were measured over a 2-week period. The main assumption needed for separation of three C sources in CO2 efflux, i.e., identical decomposition of applied C3 and C4 sugars in soil, was investigated and proven. The relative contribution to the CO2 efflux was higher, but shorter with an increased (microbial) availability of the C source, i.e., sugar > slurry > SOM. The shortcomings and limitations as well as possible future applications of the suggested method are discussed. Anwendung der natürlichen 13C-Abundanz zur Trennung von drei CO2 -Quellen bei der Inkubation eines mit Gülle und Zucker behandelten Graslandbodens Die Untersuchung beschreibt ein neues Verfahren zur Trennung von drei C-Quellen im Boden mit Hilfe einer Tracermethode (hier die natürliche 13C-Abundanz). Die zeitliche Dynamik des CO2 -Effluxes aus einem C3 -Graslandboden nach der Applikation von C3 - oder C4 -Gülle und/oder C3 - oder C4 -Zucker wurde verfolgt, um die Anteile der drei unabhängigen C-Quellen (organische Bodensubstanz (OBS), Gülle und Zucker) am CO2 -Efflux zu untersuchen. Boden mit Gülle und/oder Zucker wurde unter kontrollierten Bedingungen inkubiert, und die CO2 -Konzentration und ihre ,13C-Werte wurden im Laufe von zwei Wochen gemessen. Die Hauptvoraussetzung der Methode zur Trennung der drei C-Quellen , identischer Abbau von zugeführten C3 - und C4 -Zuckern im Boden , wurde geprüft. Der relative Beitrag zum CO2 -Efflux wurde höher, die Dauer jedoch kürzer mit steigender (mikrobieller) Verfügbarkeit der C-Quelle: Zucker > Gülle > OBS. Die Mängel, Einschränkungen und mögliche künftige Anwendungen der vorgeschlagenen Methode werden diskutiert. [source]

Human tactile perception as a standard for artificial tactile sensing,a review

THE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 1 2004
J Dargahi
Abstract In this paper, we examine the most important features of human skin tactile properties with special emphasis on the characteristics which are vital in the design of artificial systems. Contrary to the visual and auditory senses, the touch signal is not a well-defined quantity. As a result, the researchers of this field are still dealing with the basics of collecting the most relevant data. Following this, mimicking the sense of touch by producing artificial tactile skin is a challenging process. Although the sense of touch is widely distributed all over the human body, the tactile perception in the human hand is of great importance in terms of surgical and medical robotics applications. In this study, the role of various mechanoreceptors in the human hand, such as, RA, SA I, SA II, and PC units are discussed in relation to the stimuli like force, position, softness, and surface texture. Taking human hand as a suitable tactile model, the necessary engineering features of an artificial tactile sensor, such as, spatial and temporal resolutions, force sensitivity, and linearity, are being reviewed. In this work, we also report on the current and possible future applications of tactile sensors in various surgical procedures. Copyright © 2004 Robotic Publications Ltd. [source]

Watching the birdie watching you: eyewitness memory for actions using CCTV recordings of actual crimes

APPLIED COGNITIVE PSYCHOLOGY, Issue 4 2001
Penny S. Woolnough
In this paper we describe a method of assessing eyewitness performance for actual crimes that could prove a valuable addition to more traditional experimental and field-based approaches to the study of eyewitnessing. We present the findings of the first reported attempt to assess the accuracy of information contained in police statements given by eyewitnesses to actual criminal episodes using CCTV as a means of verification. Employing the criterion of using only those items that could be verified against CCTV recordings (largely action details), both victims and bystanders from eight incidents of assault were found to be highly accurate in their accounts (96% accurate). These results are discussed in terms of what they might indicate about the relationship between arousal and eyewitness performance and how they compare with laboratory and other field-based approaches to the study of eyewitness memory. In addition, we consider some of the methodological, technological and practical constraints associated with this novel approach and its possible future applications to the study of everyday memory as well as memory for unusual events. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Hydrogen photoproduction by nutrient-deprived Chlamydomonas reinhardtii cells immobilized within thin alginate films under aerobic and anaerobic conditions

BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2009
Sergey N. Kosourov
Abstract A new technique for immobilizing H2 -photoproducing green algae within a thin (<400 µm) alginate film has been developed. Alginate films with entrapped sulfur/phosphorus-deprived Chlamydomonas reinhardtii, strain cc124, cells demonstrate (a) higher cell density (up to 2,000 µg Chl mL,1 of matrix), (b) kinetics of H2 photoproduction similar to sulfur-deprived suspension cultures, (c) higher specific rates (up to 12.5 µmol,mg,1,Chl,h,1) of H2 evolution, (d) light conversion efficiencies to H2 of over 1% and (e) unexpectedly high resistance of the H2 -photoproducing system to inactivation by atmospheric O2. The algal cells, entrapped in alginate and then placed in vials containing 21% O2 in the headspace, evolved up to 67% of the H2 gas produced under anaerobic conditions. The results indicate that the lower susceptibility of the immobilized algal H2 -producing system to inactivation by O2 depends on two factors: (a) the presence of acetate in the medium, which supports higher rates of respiration and (b) the capability of the alginate polymer itself to effectively separate the entrapped cells from O2 in the liquid and headspace and restrict O2 diffusion into the matrix. The strategy presented for immobilizing algal cells within thin polymeric matrices shows the potential for scale-up and possible future applications. Biotechnol. Bioeng. 2008. Biotechnol. Bioeng. 2009;102: 50,58. © 2008 Wiley Periodicals, Inc. [source]