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Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. These actuators suffer from an operational instability, the so-called pull-in effect that limits the actuators’ travel range to one third of the electrode separation. High driving voltages and large electrode gaps are required to achieve large displacements. In our work, we present a novel electrostatic actuator class, which allows high deflections with nanometric electrode separation. The approach presented utilizes a bimorph like effective lever to transform electrostatic forces into deflection. It permits to make use of high electrostatic forces generated in small gaps and thus gives access to large actuator deflections. We demonstrate that quasi-static deflections as large as four times the gap size are possible. [ABSTRACT FROM AUTHOR]

Summary: Objectives: To determine factors associated with diagnostic yield of ENB. Methods: In 112 consecutive patients referred to our department between March 2010 and December 2010 the diagnostic work-up for solitary pulmonary lesions included a FDG-PET-CT scan, and ENB in combination with ROSE. The final diagnosis was confirmed by histopathological evaluation of specimen obtained either by ENB, or – if ENB was not diagnostic – by CT-guided fine needle aspiration or surgery. Results: Thirty-seven (33%) subjects were female, mean age was 66.7 (±1.04) years. The mean diameter of lesions was 27mm (range: 6–46mm). In 83.9% the combination of PET-CT, ENB, and ROSE established a correct diagnosis, as defined by the definite histopathological result. 15.2% (17/112) of lesions were benign, and 84.8% (95/112) were malignant. For 112 procedures we observed a steep learning curve with a diagnostic yield of 80% and 87.5% for the first 30 and last 30 procedures, respectively. The diagnostic yield in lesions ≤20mm and >20mm in diameter was 75.6% and 89.6% (p =0.06), respectively. No significant difference in diagnostic yield was seen depending on lung function, and the localization of the lesions. Two cases (1.8%) of pneumothorax were seen during and up to 24h after bronchoscopy, none of them required a chest tube. Conclusion: Diagnostic yield increased with experience but was independent from the size of the lesion, the localisation in the lungs, and lung function. The diagnostic yield of ENB can be as high as for CT-guided transthoracic biopsies but carries a significantly lower complication rate. [Copyright &y& Elsevier]

Abstract: This paper reports on procedure and preliminary research results of long-term fatigue tests up to a number of 109 cycles on shot peened helical compression springs with two basic dimensions, made of three different spring materials. The corresponding research project was initiated together with a working group of the Association of German Springs’ Industry (VDFi – Verband der Deutschen Federnindustrie). The test springs were manufactured of oil hardened and tempered SiCr- and SiCrV-alloyed valve spring steel wires and of a stainless steel wire with diameters of 1.6mm and 3.0mm and finally shot peened. Fractured test springs were investigated by stereo-microscope, Scanning Electron Microscope (SEM) and by means of metallographic microsections in order to analyse the fracture behavior and the failure mechanisms. It becomes obvious that the various spring types in test exhibit different fatigue properties and also different failure mechanisms in the VHCF regime. [ABSTRACT FROM AUTHOR]

Summary: Background: The presence of non-reversible airway obstruction (AO) in never smokers has only received limited attention until now. Methods: We analyzed data from the Austrian Burden of Obstructive Lung Disease (BOLD) study. We defined non-reversible AO as post-bronchodilator FEV1/FVC <0.7 which corresponds to COPD I and higher (COPD I+) according to current GOLD guidelines. Significant AO was defined as FEV1/FVC <0.7 and FEV1 <80% predicted (GOLD II and higher, GOLD II+). The prevalence and characteristics of non-reversible AO in never smokers were analyzed in relation to the severity of the disease. Results: Never smokers comprised 47.3% of the study population. Non-reversible AO was seen in 18.2% of never smokers, and 5.5% of never smokers fulfilled criteria for significant non-reversible AO (GOLD stage II+). Therefore, the resulting population prevalence of significant non-reversible AO (GOLD stage II+) was 2.6%. Never smokers with non-reversible AO were predominantly female and slightly older. The airway obstruction was found to be less severe as compared with ever smokers. Despite this, 20% of never smokers with significant non-reversible AO (GOLD stage II+) reported respiratory symptoms and 50% reported impairment of quality of life. This burden of illness in never smokers was similar to that in smokers when severity of AO was taken into account. Conclusion: Approximately every third subject with non-reversible AO has never smoked, yet still demonstrates a substantial burden of symptoms and impairment of quality of life. Never smokers should receive far greater attention when efforts are undertaken to prevent and treat chronic airway obstruction. [Copyright &y& Elsevier]

Abstract: This report presents first results of very high cycle fatigue tests on helical compression springs which respond to external compressive forces with torsional stresses. The results of these investigation can add an important contribution to the experience of fatigue behaviour in the very high cycle regime. Most investigations performed on that field deal with specimens under tensile or rotating bending load. The springs tested were manufactured of Si–Cr-alloyed valve spring wire with a wire diameter between 2 and 5mm, shot-peened and preset. Compared to the fatigue limits evaluated in fatigue tests on these springs up to 107 cycles substantial decreases in fatigue strength are to be observed if the fatigue tests are continued up to 108 cycles or even more. It is obvious that nucleations of fractures tend to occur below the surface, if fractures happen after more than 107 cycles. Investigations of broken springs by scanning electron microscope show a typical appearance of fracture initiation sites without non-metallic inclusions at the nucleations of fracture. [Copyright &y& Elsevier]

Abstract: Long-term fatigue tests on shot peened helical compression springs were conducted by means of a special spring fatigue testing machine at 40Hz. Test springs were made of three different spring materials – oil hardened and tempered SiCr- and SiCrV-alloyed valve spring steel and stainless steel. With a special test strategy in a test run, up to 500 springs with a wire diameter of d =3.0mm or 900 springs with d =1.6mm were tested simultaneously at different stress levels. Based on fatigue investigations of springs with d =3.0mm up to a number of cycles N =109 an analysis was done after the test was continued to N =1.5×109 and their results were compared. The influence of different shot peening conditions were investigated in springs with d =1.6mm. Fractured test springs were examined under optical microscope, scanning electron microscope (SEM) and by means of metallographic microsections in order to analyse the fracture behaviour and the failure mechanisms. The paper includes a comparison of the results of the different spring sizes, materials, number of cycles and shot peening conditions and outlines further investigations in the VHCF-region. [Copyright &y& Elsevier]

Abstract: Ultrasonic force microscopy (UFM) is used to resolve the elastic nanostructure of strained antimony (Sb) particles. These nanoparticles were formed by aggregation and spontaneous rapid crystallization of thermally deposited Sb onto the (0001) basal planes of highly oriented pyrolytic graphite (HOPG) and molybdenum disulfide (MoS2). UFM reveals clear contrast within individual nanoparticles, which can be attributed to differences in the local stiffness. This interpretation is confirmed by transmission electron microscopy (TEM) images, in which bending contours prove the existence of strained regions within the nanocrystals. [Copyright &y& Elsevier]

In the present study the electrical properties of 100 nm and 400 nm alumina films grown by the atomic layer deposition technique on p -type Si before and after a post-deposition annealing at 440 °C and after a dc H plasma treatment at different temperatures are investigated. We show that the density of interface states is below 2 × 10 10 cm −2 in these samples and this value is significantly lower compared to that reported previously in thinner alumina layers (below 50 nm). The effective minority carrier lifetime τ g,eff and the effective surface recombination velocity s eff in untreated p -type Si samples with 100 nm and 400 nm aluminum oxide is comparable with those obtained after thermal oxidation of 90 nm SiO 2 . Both, a post-deposition annealing in forming gas (nitrogen/hydrogen) at elevated temperatures and a dc H-plasma treatment at temperatures close to room temperature lead to the introduction of negatively charged defects in alumina films. The results obtained in samples annealed in different atmospheres at different temperatures or subjected to a dc H plasma treatment allow us to correlate these centers with H-related defects. By comparing with theory we tentatively assign them to negatively charged interstitial H atoms. [ABSTRACT FROM AUTHOR]

An all earth-abundant and precious metal-free photocathode based on a low-temperature fabricated amorphous silicon tandem junction is demonstrated to be an efficient device for solar water splitting. With a particular designed Al/Ni layer stack as photocathode/electrolyte contact an onset potential for cathodic photocurrent of 1.7 V vs. RHE and a saturation photocurrent density of 7.2 mA/cm 2 were achieved. For a high-cost alternative with a Ag/Pt layer stack an even higher photocathode performance is demonstrated. Above all we present an approach for a dedicated photovoltaic and electrochemical development for solar water splitting. [ABSTRACT FROM AUTHOR]