Two microcell flow-injection analysis (FIA) platforms for capacitive silicon-based field-effect sensors

pH- and penicillin-sensitive electrolyte-insulator-semiconductor (EIS) sensors (Al/Si/SiO₂/Ta₂O₅ and penicillinase) have been successfully integrated into a commercial flow-injection analysis (FIA) system. For the FIA set-up, a miniaturised home-made flow-through cell of plexiglass with a variable internal volume from 12 to 48 μl has been developed. As a second platform, an SU-8 based miniaturised flow-through cell, also combined with a pH-sensitive EIS structure, has been fabricated at wafer level. The application of SU-8 as a photoresist with good qualities (distinct chemical resistance, high aspect ratio, good mechanical and dielectric behaviour) is favoured. Different channel/sensor layouts have been realised with sensitive areas of the EIS sensors of 1.7-8.2 mm² and sample volumes of 0.3-4 μl, respectively. FIA parameters (sample volume, flow rate, distance between injection valve and sensor) have been optimised in terms of high throughput, minimum dispersion, fluid consumption, sensitivity and reproducibility.     

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让越来越多的电子设备来参与汽车操控已经是大势所趋。F1汽车赛不仅是一项汽车高科技的竞赛,更兼有将未来的汽车技术展示给人们的效果。翻阅历史资料,可以知道在上世纪五六十年代,汽车安全带并不是车     

Effect of ceramic filler content on the mechanical and thermal behaviour of poly-<Emphasis Type="SmallCaps">l</Emphasis>-lactic acid and poly-<Emphasis Type="SmallCaps">l</Emphasis>-lactic-co-glycolic acid composites for medical applications

One main application of resorbable poly-l-lactic acid (PLLA) and poly-l-lactic-co-glycolic acid (PLGA) based materials is in medical implants. In this study composites were made from PLLA and PLGA with hydroxyapatite (HAp) respective β-tricalcium phosphate (β-TCP) fillers. The filler content and particle size were varied, and the thermal properties as well as the mechanical strength of the composites were investigated. The composites were made by an extrusion compounding process giving 2–2.5 mm diameter sized profiles. The results verified that the thermal stability of the composites was reasonable during the optimized compounding conditions. Scanning electron microscopy revealed that the fillers were well dispersed in the polymer matrices. The mechanical properties were improved by the addition of the fillers. The optimum mechanical properties for the extruded profiles were obtained with the HAp fillers. The E-modulus was increased from 3.3 to 4.6 GPa by addition of filler particles (30 wt%) whereas the flexural strength was reduced from 133 to 106 MPa.     

Study of Heat Recovery in Spray Booths

More frequently, spray booths are offered with cross recuperators. The paint stop filters do not provide a complete cleaning of the air from the overspray particles. The layers of sediment of paint particles grow up on the walls of the extraction duct and recuperator fins. Forming sediment is a thermal insulator. This paper presents the results of a preliminary analysis of sediments growth rate and the impact of overspray deposits on heat recovery in spray booths.     

Exact OBDD Bounds for Some Fundamental Functions

Ordered binary decision diagrams (OBDDs) are nowadays one of the most common dynamic data structures or representation types for Boolean functions. Among the many areas of application are verification, model checking, computer aided design, relational algebra, and symbolic graph algorithms. Although many exponential lower bounds on the OBDD size of Boolean functions are known, there are only few functions where the OBDD size is asymptotically known exactly. In this paper the exact OBDD sizes of the fundamental functions multiplexer and addition of n-bit numbers are determined.     

Pressure - temperature relations in the silver - tellurium system at 75 at-% tellurium

The p,T-relations in the silver-tellurium system at 75 at-% Te were studied by high pressure DTA and quenching experiments at pressures up to 3.2 GPa. Fitted data for the phase boundaries are given. AgTe₃ becomes a stable phase in the system above 0.4 GPa. In quenching melts with a nominal composition AgTe₃ from high temperatures, stable and metastable equilibria can be observed. Conditions for the formation of homogeneous AgTe₃ from the melts in the low-pressure region are discussed.     

Process safeguarding throughout the product life cycle

Measurement technologies are mandatory in different manufacturing technologies and can be found in all phases of the product life cycle. Often there are a lot of parameters that influence process quality. The limitations of sensor-based measuring methods with which quality-affecting quantities can be detected are also unknown. Therefore, quality loops are needed to react to imperfections at an early stage and to minimize the reject rate.A large, up to now incompletely examined field is the influence of surface contaminations on subsequent processes such as adhesive bonding, coating, soldering, welding, hardening, etc. As an example the paper will concentrate on a hardening process succeeding a machining process.     

Multiplexed Nucleic Acid Hybridization Assays Using Single‐FRET‐Pair Distance‐Tuning

Multiplexed photoluminescence (PL) detection plays an important role in chemical and biological sensing. Here, it is shown that time‐gated (TG) detection of a single terbium‐donor‐based Förster resonance energy transfer (FRET) pair can be used to selectively quantify low nanomolar concentrations of multiple DNAs or microRNAs in a single sample. This study demonstrates the applicability of single‐TG‐FRET‐pair multiplexing for molecular (Tb‐to‐dye) and nanoparticle (Tb‐to‐quantum‐dot) biosensing. Both systems use acceptor‐sensitization and donor‐quenching for quantifying biomolecular recognition and modification of the donor–acceptor distance for tuning the PL decays. TG intensity detection provides extremely low background noise and a quick and simple one‐step assay format. Single‐TG‐FRET‐pair multiplexing can be combined with spectral and spatial resolution, paving the way for biosensing with unprecedented high‐order multiplexing capabilities.     

Atomic and electronic structure of Si dangling bonds in quasi-free-standing monolayer graphene

Nano Research - Si dangling bonds at the interface of quasi-free-standing monolayer graphene (QFMLG) are known to act as scattering centers that can severely affect carrier mobility. Herein, we...