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Simple Device (simple + device)

Distribution by Scientific Domains
Medical Sciences44%

Selected Abstracts

Simple devices for measuring complex ultrashort pulses

LASER & PHOTONICS REVIEWS, Issue 3 2009
R. Trebino
Abstract We describe experimentally simple, accurate, and reliable methods for measuring from very simple to potentially very complex ultrashort laser pulses. With only a few easily aligned components, these methods allow the measurement of a wide range of pulses, including those with time-bandwidth products greater than 1000 and those with energies of only a few hundred photons. In addition, two new, very simple methods allow the measurement of the complete spatio-temporal intensity and phase of even complex pulses on a single shot or at a tight focus. [source]

A spring-driven press device for hot embossing and thermal bonding of PMMA microfluidic chips

ELECTROPHORESIS, Issue 15 2010
Zhi Chen
Abstract A novel spring-driven press device was designed and manufactured for hot embossing and thermal bonding of PMMA microfluidic chips in this work. This simple device consisted of two semi-cylinder silicone rubber press heads, three steel clamping plates, and three compression springs that were assembled together using two screw bolts and two butterfly nuts. The three springs were clamped between the upper and the middle clamping plates, whereas the two press heads were assembled between the middle and the lower clamping plates. After an epoxy template covered by a PMMA plate or a PMMA channel plate together with a cover were sandwiched between two microscopic glass slides for embossing or bonding, respectively, they were clamped between the two elastic press heads of the press device by fastening the screw nuts on the upper clamping plate. Because the convex press heads applied pressure along the middle line of the glass slides, they would deform resulting in a negative pressure gradient from the middle to the sides so that air bubbles between the sandwiched parts could be squeezed out during embossing and bonding processes. High-quality PMMA microfluidic chips were prepared by using this unique device and were successfully applied in the electrophoretic separation of several cations. [source]

Application of siphon principle to fluid drainage in transurethral surgery

INTERNATIONAL JOURNAL OF UROLOGY, Issue 8 2006
AKITO TERAI
Abstract, Transurethral resection is usually performed using an all-in-one drape with a fluid collection pouch, drainage port and hose. Gravity drainage of irrigation fluid through the hose is often hampered, resulting in fluid retention in the pouch. We applied a siphon principle to facilitate fluid drainage by making a U-shaped bend near the distal end of the hose, using an adhesive tape, and hooking the distal end of inverted U shape on the edge of bucket placed on the floor. When the hose is filled with irrigation fluid up to the crest of the siphon, fluid flow driven by atmospheric pressure continues until the pouch is evacuated. Repriming and restarting occur automatically throughout the operation. This simple device has virtually eliminated fluid retention in the pouch and proved to be especially useful in transurethral prostatectomy, which requires a large amount of irrigation fluid. [source]

"Gumnut" Device for Off-Pump Proximal Aortocoronary Anastomosis

JOURNAL OF CARDIAC SURGERY, Issue 5 2008
Mark A. J. Newman F.R.A.C.S.
We describe the use of a simple device to avoid use of side-biting clamp on aorta for proximal aortocoronary anastomosis. [source]

A simple device for the evaluation of the UV radiation index

METEOROLOGICAL APPLICATIONS, Issue 2 2003
Giuseppe Rocco Casale
The solar ultraviolet radiation (UV) flux density at the earth's surface depends on the incoming solar energy and the transmission properties of the atmosphere. UV radiation is strongly absorbed by ozone in the spectral range 200,310 nm, while the attenuation is increasingly weaker at longer wavelengths. Following the discovery of the Antarctic ozone hole in 1985, the risk of a possible UV increase at ground level, due to the observed stratospheric ozone depletion, has heightened the interest within the scientific community given the potentially harmful effects on terrestrial and aquatic ecosystems. Spectroradiometers, broad-band meters and dosimeters may be used for measurements of solar UV. In addition, radiation transfer models can be used to quantify UV irradiances at various times and locations, provided that the extraterrestrial solar radiation and the state of the atmosphere are known. Information about UV radiation at the earth's surface is given by the ultraviolet index ,UVI', which is defined as the effective integrated irradiance (280,400 nm) weighted by the erythemal action spectrum. The UV Index is widely used by many international weather services as an indicator of UV levels at the earth's surface providing public awareness of the effects of prolonged exposure to the sun's rays. The aim of this paper is to present a device capable of estimating the UV Index. This device is a compact disc, used as a sundial, and is based on modelled UV irradiances derived from the STAR radiative transfer model (System for Transfer of Atmospheric Radiation). The device was tested in an urban setting under clear sky conditions. Copyright © 2003 Royal Meteorological Society [source]

Analysis of a Simple Test Device for Tribo-Electric Charging of Bulk Powders

PARTICLE & PARTICLE SYSTEMS CHARACTERIZATION, Issue 1-2 2009
upuk
Abstract We have developed a simple device to characterise the tribo-electric charging propensity of powders. A sample of around one gram of powder is shaken in a container by reciprocal strokes in a horizontal direction. The electric charge on the powder is quantified by a Faraday cup before and after shaking. In this paper, we analyse the operation of this simple test device by investigating the behaviour of ,-lactose monohydrate (,-LM), hydroxy propyl cellulose (HPC) and a 50 : 50 binary mixture (by mass) of these two powders with various container surfaces commonly used in the pharmaceutical industry. The experiments are carried out in controlled environmental conditions and using different shaking times and frequencies of 10, 20 and 30,Hz. The experimental results show that the saturated charge is independent of the shaking frequency. Furthermore adhered particles coating the inner surface of the shaking container decrease the net amount of charge generated by up to 50,%. [source]

A simple device as a guide to 15° tilt during Caesarean section

ANAESTHESIA, Issue 9 2003
C. Siegmueller
No abstract is available for this article. [source]

Calibration of three capnographs for use with helium and oxygen gas mixtures,

ANAESTHESIA, Issue 2 2003
J. A. S. Ball
Summary Capnography is considered essential in the management of mechanically-ventilated patients. Helium, as an adjunct to mechanical ventilation, is the subject of renewed interest and used increasingly. However, helium affects the performance of infrared capnometry. We constructed a simple device to generate variable mixtures of helium, oxygen and carbon dioxide within the normal physiological range, and tested the performance of two side-stream and one in-line capnographs. We found that addition of helium to the gas mixture caused all three capnographs to underestimate the concentration of carbon dioxide. The underestimation increased as the proportion of helium increased. The maximum underestimation (30%) occurred in a 79:21 helium/oxygen mixture. [source]

Determination of DNA methylation by COBRA: A comparative study of CGE with LIF detection and conventional gel electrophoresis

ELECTROPHORESIS, Issue 17 2009
Simon Goedecke
Abstract DNA methylation as an epigenetic modification of the human genome is under emphatic investigation. Several studies have demonstrated a role of DNA methylation in oncogenesis. In conjunction with histone modifications, DNA methylation may cause the formation of heterochromatin and thus mediate the inactivation of gene transcription. It is important to develop methods that allow for an accurate quantification of the amount of DNA methylation in particular DNA regions, to gain information concerning the threshold of methylation levels necessary for gene inactivation. In this article, a CGE method with on-column LIF detection using SYBR Green is compared with a conventional slab-gel electrophoresis. We thus investigate the validity to analyze DNA methylation in the samples of a combined bisulfite restriction analysis. It is demonstrated that CGE is superior to gel electrophoresis in means of linearity, precision, accuracy, automatization (high throughput), and sample consumption. However, gel electrophoresis is easier to perform (simple devices, no PC usage), and the running costs are comparatively low. A further advantage of CGE is the sparse use of toxic compounds (MeOH and SYBR Green), whereas gel electrophoresis is performed in polyacrylamide gels with ethidium bromide staining. [source]