A mixer design for the pigtail braid

The stirring of a body of viscous fluid using multiple stirring rods is known to be particularly effective when the rods trace out a path corresponding to a nontrivial mathematical braid. The optimal braid is the so-called "pigtail braid", in which three stirring rods execute the usual "over-under" motion associated with braiding plaiting) hair. We show how to achieve this optimal braiding motion straightforwardly: one stirring rod is driven in a figure-of-eight motion, while the other two rods are baffles, which rotate episodically about their common centre. We also explore the extent to which the physical baffles may be replaced by flow structures (such as periodic islands).

单长周期光栅迈克耳孙干涉仪特性研究

单长周期光栅迈克耳孙（Michelson）干涉仪是由尾纤端面蒸镀高反膜的单根长周期光纤光栅构成。入射光经长周期光栅后，部分被耦合到包层中传输。经过包层和纤芯传输的光信号经尾纤端面反射后，重新耦合回到长周期光栅中，在光栅区域形成干涉。通过理论计算分析了各种因素对其光谱响应的影响。从实验上得到了干涉光谱的谐振峰波长位移与光纤段温度变化成良好的线性关系，测得其温度系数为31．3pm／℃。表明这种结构可用于高温传感或作为波分复用滤波器。

Behandlingsmetoder och amningsförekomst vid bröstböld

Bakgrund: Amningens fördelar för mor, barn och samhälle är välkända. En komplikation vid amning är bröstböld. Medvetenhet om fördelar och nackdelar med olika behandlingsmetoder vid bröstböld och deras inverkan på fortsatt amning är viktig. Syftet: Att studera behandlingsmetoder och amningsförekomst vid bröstböld. Metod: Retrospektiv design från en journalgranskning genomförd på Södersjukhuset mellan januari 2006 och september 2008. Statistiska analyser genomfördes med Chi-två test, Independent samples T-test samt Fishers exakta test. Resultat: Totalt 139 kvinnor med bröstböld behandlades med nålpunktions-, pigtail- eller dränagebehandling, eller en kombination av dessa. Sextiotre procent pigtailbehandlades enbart och dessa behövde i mindre omfattning sjukhusinläggning jämfört med ej enbart pigtailbehandlade, samt resulterade i större andel av ett till tre sjukhusbesök. Enbart dränagebehandling och flera metoder resulterade i större andel sjukhusinläggningar än ej enbart dränagebehandling och en metod. Amningsförekomsten sjönk från 96 procent före behandling till 69 procent en månad efteråt. Konklusion: Enbart pigtailbehandling var den vanligaste metoden och resulterade i färre sjukhusinläggningar och sjukhusbesök. Förekomsten av amning hade sjunkit efter behandling av bröstböld

Newly designed, self-coiling catheters for regional anesthesia--an imaging study

A major concern with the use of continuous peripheral nerve block is the difficulty encountered in placing the catheters close enough to the nerves to accomplish effective analgesia. The aim of this study was to investigate if a self-coiling catheter would remain close to the sciatic nerve once introduced through needles placed under ultrasound guidance and if contrast dye injected through the pigtail catheter made direct contact to the nerves.

Ultra small integrated optical fiber sensing system

This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs) and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 µm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL), fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

Ultra small integrated optical fiber sensing system

This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs) and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 µm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL), fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.