Characterization of semiconductor devices by infrared laser interferometry

The principles of characterization techniques for semiconductor devices based on infrared laser interferometry are reviewed. Transient optical signals due to plasma-and thermo-optical effects are studied by experiment and numerical modeling, providing information on carrier concentration and lattice temperature in the device. The applicability of the techniques is demonstrated on smart power devices, VDMOSFETs, IGBTs and on sub-micron technology MOS- and bipolar transistors.     

Automatic identification of bacterial types using statistical imaging methods

The objective of the current study is to develop an automatic tool to identify microbiological data types using computer-vision and statistical modeling techniques. Bacteriophage (phage) typing methods are used to identify and extract representative profiles of bacterial types out of species such as the Staphylococcus aureus. Current systems rely on the subjective reading of profiles by a human expert. This process is time-consuming and prone to errors, especially as technology is enabling the increase in the number of phages used for typing. The statistical methodology presented in this work, provides for an automated, objective and robust analysis of visual data, along with the ability to cope with increasing data volumes.     

Highly emissive nano rod-in-rod heterostructures with strong linear polarization

We report the synthesis of CdSe/CdS rod in rod core/shell heterostructures. These rods, synthesized using a seeded-growth approach, show narrow distributions of rod diameters and lengths and exhibit high emission quantum efficiencies and highly polarized emission. The degree of polarization is controlled by the inner core rod dimensions, and it is equal or up to 1.5 times higher than the polarization of equivalent sphere in rod systems. Using the method of photoselection we measure the polarization anisotropy at different excitation wavelengths and study the interplay between electronic contribution and dielectric effects in determining the absorption and emission polarization.     

Scaling-index method as an image processing tool in scanning-probe microscopy

The scaling-index method (SIM) is a novel tool for image processing in scanning-probe microscopy. Originating from the theory of complex systems, the SIM can be used in order to extract structural information from arbitrary data sets. This method can readily be applied to the analysis of digital atomic-force microscopy (AFM) images. Especially for biomedical diagnostics, where genetic material is investigated by various microscopic methods, a reliable image segmentation based on the SIM algorithm is helpful. As a first application, AFM-images of GTG-banded human metaphase chromosomes (with G bands obtained by Trypsin using Giemsa) are compared with micrographs from conventional light microscopy by means of a scaling-index analysis. While the grey-level distributions of the optical and the AFM-images are largely different from each other, the scaling-index images are remarkably similar. Using this method, a fingerprint of an image can be produced which helps in the classification and interpretation of the measured data.     

GTG banding pattern on human metaphase chromosomes revealed by high resolution atomic-force microscopy

Surface topography of human metaphase chromosomes following GTG banding was examined using high resolution atomic force microscopy (AFM). Although using a completely different imaging mechanism, which is based on the mechanical interaction of a probe tip with the chromosome, the observed banding pattern is comparable to results from light microscopy and a karyotype of the AFM imaged metaphase spread can be generated. The AFM imaging process was performed on a normal 2 n  = 46, XX karyotype and on a 2 n  = 46, XY, t(2;15)(q23;q15) karyotype as an example of a translocation of chromosomal bands.     

Copolymerization of norbornene containing 3,5-di-tert-butyl-4-hydroxybenzoyl group with norbornene using metathesis catalyst

Summary The ring opening metathesis copolymerization of 5-{[(3,5-di-t-butyl-4-hydroxybenzoyl)oxy]methyl}-2-norbornene (BHBN) with norbornene was carried out using Ru and Os based catalysts. Analysis of the copolymers obtained during the initial stages of copolymerization revealed that both monomers were incorporated randomly and with the same reactivity, indicating that the steric effect of BHBN is not important. The molecular weights of copolymers were found to be in the order of 3×10⁵ with dispersity of around 2. Characterization and some properties of these copolymers are described.     

Natural hormone patterns of meat from steers and bulls depending on slaughter age

 Natural patterns of steroid hormones (androgens, progestogens and corticoids), their precursors and metabolites were analysed in 48 beef samples with gas chromatography-mass spectrometry (GC-MS). Muscle tissue samples were taken from steers (n=23) and bulls (n=25) of the breed German Simmental, which were slaughtered at different ages (151–705 days of age). Concentrations of testosterone, dehydroepiandrosterone (DHEA), progesterone, cortisol and cortisone in beef from steers were not dependent on age, whereas pregnenolone, androstenedione and epitestosterone increased significantly with increasing slaughter age (r=0.48, P<0.05;r=0.60, P<0.01 and r=0.62, P<0.001, respectively). The concentrations of the metabolite androsterone tended to increase as well. The differences were not significant, however, due to the high level of variability. In beef from bulls cortisone concentrations were inversely correlated with increasing slaughter age (r=–0.47, P<0.05). The decrease from day 175 to day 260 was significant. Testosterone was positively correlated with increasing age (r=0.46, P<0.05). The tissue concentrations at the different slaughter ages did not differ significantly, however. The Δ5-precursors pregnenolone and DHEA tended to show a minimum at the age of 370 days, followed by a significant increase. No age dependence of the progesterone, androstenedione, androsterone, epitestosterone and cortisol concentrations could be detected. Analysis of steroid hormone concentrations may form part of a reliable method for estimating the age of slaughtered cattle. In this study, the age of samples was estimated to within ± an average of 10 weeks. Received: 29 December 1997 / Revised version: 1 March 1998     

Modeling psychotherapy outcome as an event in time: An application of multistage analysis.

Standard survival analysis (SA) and multistate analysis (MSA) are methods for modeling categorical psychotherapy outcome events over time. The underlying principles, mathematical details, and indications for using each technique are discussed, and data from an anorexia nervosa psychotherapy outcome study comparing psychodynamic psychotherapy with psychodynamic psychotherapy plus cognitive–behavioral techniques are used to illustrate the use of SA and MSA techniques. MSA includes multiple competing outcome states in a single model. A single MSA model includes reaching target weight and treatment dropout before reaching target weight as competing events. It is concluded that MSA is an informative analytic technique in the domain of psychotherapy research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intraneural lidocaine uptake compared with analgesic differences between pregnant and nonpregnant rats

BACKGROUND AND OBJECTIVES: Pregnant patients need less local anesthetic in order to obtain the same quality of functional block as nonpregnant patients. Our goal was to demonstrate a similarly increased functional susceptibility to local anesthetics in the awake pregnant rat during peripheral nerve block and to investigate the pharmacokinetic and/or pharmacodynamic mechanisms responsible for this phenomenon. METHODS: Radiolabeled lidocaine uptake was determined in vivo during sciatic nerve block with 0.1 ml of 1% lidocaine in the nerves of nine pregnant and five nonpregnant female rats and six male rats at the return of deep pain sensation, assessed by withdrawal of the hindlimb from a brief squeeze of a digit with serrated forceps. During recovery from complete functional block, the time at which deep pain returned and the amount of lidocaine in the nerve at that time were compared among the three groups of rats. Lidocaine content was also determined in vitro after exposure of ensheathed sciatic nerves from pregnant and nonpregnant rats to a 0.2% lidocaine bath for specified times. RESULTS: Full block of function developed in all groups within 6 minutes of the lidocaine injection and lasted significantly longer in pregnant rats than in nonpregnant and male rats (49.0 +/- 3.3 vs 34.0 +/- 3.1 and 32.0 +/- 1.3 minutes mean +/- SEMI, respectively. At the time of deep pain return, the intraneural lidocaine content of pregnant rats was significantly lower than that of nonpregnant and male rats (2.2 +/- 0.25 vs 3.9 +/- 0.7 and 3.7 +/- 0.6 nmoles/mg of wet nerve, respectively). No difference in lidocaine uptake kinetics between P and NP nerves was observed in vitro. CONCLUSIONS: Block of peripheral neural function is prolonged in pregnant rats, and lidocaine content in the nerve is lower at a specific stage of neural block. These results are consistent with a pharmacodynamic mechanism for increased susceptibility to lidocaine neural block during pregnancy.     

Investigations on possibilities of inline inspection of high aspect ratio microstructures

LIGA is the basic idea of promising developments for the manufacturing of microelectromechanical system parts containing high aspect ratio microstructures. Aim of the work is a brief discussion of the starting-points for inline process inspection within a direct LIGA technology using deep X-ray lithography for the production of micromechanical gear wheels with critical dimensions of ∼35 μm width at ∼1 mm height as well as to show methodic and technical measuring possibilities. Firstly, results of the determination of residual solvent content distribution within ultra-thick SU-8 films are shown obtained from refracted near field optical measurements. Furthermore, the capability of X-ray computer tomographic imaging is discussed and measurements for the determination of the three-dimensional shape of high aspect ratio microstructures are practically demonstrated with microscopic and interferometric optical methods. Finally, first results demonstrate the potential of the optical coherence tomography for several further important measurement tasks, among others, e.g. for the imaging of the distribution of mechanical stress at the resist–substrate interface. The results show that much information which is essential in the LIGA process can be achieved with recently available measurement methods. However, further development of non-destructive measurement techniques would be desirable for an effective inline process control of mass production of micromechanical parts. This work is a summary of the poster “Residual Solvent Content Distribution in Ultra-Thick SU-8 Films and Its Influence on the Imaging Quality” and of the presentation “Possibilities of Inline Process Inspection of High Aspect Ratio LIGA Micro Structures” to the High Aspect Ratio Micro Structure Technology workshop HARMST 2005 held in Gyeongju (Republic of Korea), June 10–13, 2005.