Tiled STED Imaging of Extended Sample Regions

Stimulated Emission Depletion (STED) nanoscopy has become one of the most used nanoscopy techniques over the last decade. However, most recordings are done in specimen regions no larger than 10–30 × 10–30 µm2 due to aberrations, instability and manual mechanical stages. Here, we demonstrate automated STED nanoscopy of extended sample regions up to 0.5 × 0.5 mm2 by using a back-aperture-stationary beam scanning system. The setup allows up to 80–100 x 80–100 µm2 field of view (FOV) with uniform spatial resolution, a mechanical stage allowing sequential tiling to record larger sample areas, and a feedback system keeping the sample in focus at all times. Taken together, this allows automated recording of theoretically unlimited-sized sample areas and volumes, without compromising the achievable spatial resolution and image quality.

The bioconversion of municipal solid waste in the biodrying reactor

The bioconversion process of municipal solid waste was assessed on the basis of the results obtained from the biodrying reactor working at a full industrial scale. The bio- reactor is a part of mechanical-biological installation following mechanical stage. The bio-reactor was equipped with measuring devices allowing the analysis of the parameters like: temperature both inside the waste and also air above the waste and also the humidity of waste during the 14 days of the biodrying process. The kinetics of bioconversion was assessed basing on measured the loss of ignition (LOI) parameter detected during the biodrying process.The LOI value of the samples varied from 17.03% d.m. to 30.34% d.m. depending on the location inside the reactor. The estimated kinetic rate constant kT of the bioconversion of biomass in the industrial reactor was kT = 0.3141.In analyzed case study the calorific value of product leaving the full-scale bio-reactor is too low to use this product as an alternative fuel. As was stated, the reason of this is too low a share of the carbon-rich fraction in the feedstock.

Studying of Optical Fiber Strain Using Speckle Pattern Correlation

The present work discusses the optical fiber strain induced by the thermal and the mechanical effects. Two different optical fibers of different core diameters were used in the study. The thermal effect was induced by temperature control system in order to raise optical fibers temperatures to controlled values. The mechanical stress was induced on the optical fibers by a micro mechanical stage. The sensitivity of the optical fibers to both effects was studied by speckle pattern correlation in which the speckles are recorded at each disturbance and analyzed. By tracing the recorded speckles , x and y displacements could be measured and the strain could be determined in two dimensions. Power attenuation in each fiber was studied in each case as well. Both speckle correlation and power attenuation techniques used in the study showed similar indication on the sensitivity of the optical fibers to the external disturbers.

High Precision Modeling and Identification of the Near Transition Sliding Friction in a Mechanical Stage

Mechanical stages are common but very important tools to all the fields in the modern world. However, with the increasing demand for high-precision stage capability, it is found that the frictional characteristics play a more vital role for the stage motion and are worth of a careful investigation. Therefore, the problem of dynamic behavior and parameter identification for the sliding friction in a normal mechanical stage system operated in long range is studied in this paper, especially for the near transition regime between the presliding and sliding friction behaviors. A dynamic model and its corresponding identification method are proposed such that all the system parameters can identified from the derived relationships in a systematical way. The results show that the proposed method indeed works effectively with the experimental data regardless the complex composition and unevenly distributed contact conditions of the actual stage system.

Three-Dimensional Holographic Lithography Using a Spatial Light Modulator

In this paper we present a lithographic process with the ability to automatically translate and arbitrarily position three-dimensional (3D) computer-generated patterns through the use of phase holograms. This method, dynamic maskless holographic lithography (DMHL), advances current photo-directed patterning and functionalization capabilities by expanding the capability to manipulate light in real-time without the use of expensive fixed masks. The system could be used for large-scale parallel manufacturing over larger areas and for point specific serial fabrication, interrogation, and metrology. The use of coherent illumination allows for the direct creation of 3D patterns of light for lithography as opposed to the mechanical stage, layer-by-layer 3D fabrication approach typical of direct-write systems. Extrinsic control over interfacial properties will provide a method for addressing aqueous phase bionanotechnolgy experimental systems in which detection, separation, transport, and handling are vital.

Strain Dependent Transport and Mechanical Characteristics of High-current and High-Strength Type Ag/Bi2223 Composite Superconductors

ABSTRACTTensile strain dependence of electromechanical characteristics of high-current, (Hic) and high-strength, (Hs) type Ag/Bi2223 composite tapes measured at room temperature, RT and 77K is investigated. Mechanical strength of composites revealed strain-hardening signature in Bi2223 filaments due to plastic strain above the elastic limit. Critical current, Ic maintained constant value up to the elastic limit then decreased slowly before finally dropped to about 10% at 0.19% and 0.39% strain, signaling a three-stage limitation. Microstructure observations and electromechanical response of the composites suggest that a limited longitudinal, transverse, interfacial, granular and transgranular microcracks formed during gradual imposition of strain hardening in Bi2223 filaments may be responsible for the slow reduction of Ic in the medium mechanical stage.

Methodologies for Damage Identification in MEMS Structures

While significant research is focused on the design and fabrication of the MEMS devices, studies on in-service failure evolution and the consequences of failure/damage are limited. Long term embedding and reliable performance of MEMS devices in systems require understanding of failure evolution and recalibration/retuning of the devices. The objective of this research is to study the effects of micro-mechanical damage on MEMS device response and develop techniques for monitoring device failure. This work entails the development and validation of models for simulating device performance and emulating the response of damaged devices. A device level to system level hierarchical methodology is developed to simulate the electro-mechanical operation of MEMS devices. The methodology is illustrated using MEMS-based accelerometer as an example. The response of undamaged devices and devices with a damaged mechanical stage can be simulated using this method. The emulation of a damaged device is carried out using a special finite element developed to represent cracks in the mechanical stage of the MEMS device. An inverse damage detection methodology is formulated using the emulated device response, a local optimization technique and the response from a physical device which enables detection and localization of damage. The damage detection method can establish, while in operation, the extent and the location of damage in the MEMS device. Experimentation with a commercial MEMS accelerometer is performed to measure the characteristics of a physical device and the effectiveness of the damage detection method. Some correlations with experiments are presented. The impact of this research is on improved device reliability and robustness as well as self-calibration features of MEMS devices.