Improving the vibration suppression capabilities of a magneto-rheological damper using hybrid active and semi-active control

This paper presents a new hybrid active & semi-active control method for vibration suppression in flexible structures. The method uses a combination of a semi-active device and an active control actuator situated elsewhere in the structure to suppress vibrations. The key novelty is to use the hybrid controller to enable the magneto-rheological damper to achieve a performance as close to a fully active device as possible. This is achieved by ensuring that the active actuator can assist the magneto-rheological damper in the regions where energy is required. In addition, the hybrid active & semi-active controller is designed to minimize the switching of the semi-active controller. The control framework used is the immersion and invariance control technique in combination with sliding mode control. A two degree-of-freedom system with lightly damped resonances is used as an example system. Both numerical and experimental results are generated for this system, and then compared as part of a validation study. The experimental system uses hardware-in-the-loop to simulate the effect of both the degrees-of-freedom. The results show that the concept is viable both numerically and experimentally, and improved vibration suppression results can be obtained for the magneto-rheological damper that approach the performance of an active device

MAKING OF AMORPHOUS AND MICROCRYSTALLINE THIN-FILM MATERIALS OF a-Si*001*00-*00xC*00x:H, mu c-Si:H, STUDY OF PROPERTIES OF FILMS AND INSTRUMENT STRUCTURES ON THEIR BASIS

There the original production plant to decompose the silane, the methane and the silane-hydrogen mixtures in the plasma of glow high-frequency discharge stabilized by magnetic field has been developed and has been introduced. The microcrystalline layer of mu a-Si:H hydrogenated silicon has been made by the method of hydrogen dilution. The optical, photoluminescent and electroluminescent properties of a-Si*001*00-*00xC*00x:H, mu c-Si:H have been studied. The new semiconductor thin-film materials, which are compatible with the silicon electronics, which have the properties which are of interest for the apparatus of visible band (the photodetectors and the light-emitting diodes) have been createdAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

A stainless-steel-based implantable pressure sensor chip and its integration by microwelding

A stainless-steel (SS) chip of capacitive pressure sensor and its integration method are developed with a focus on smart implant applications. The sensors are entirely microfabricated with biocompatible materials, through thermal bonding of gold-polyimide diaphragm film to the chip dies made of medical-grade SS. The reference cavity design with dead-end holes created in the SS die is both theoretically and experimentally verified to enhance pressure sensitivity. Laser microwelding is investigated as an alternative integration path for this type of SS-based sensors to establish permanent and reliable bond onto SS-based platform devices. The microwelded bond is revealed to provide twice the mechanical strength and ∼6 × electrical conductance compared with a conventional conductive epoxy case. The microwelded sensors exhibit an average sensitivity of 110 ppm/mmHg close to its pre-welding level. The microwelding integrations of fabricated chips with the SS antenna stent and hypodermic needle are demonstrated. The results suggest not only that the developed pressure sensor is compatible with laser microwelding, but also that micowelding is a promising packaging technique for SS-based biomedical and implant microdevices that require long-term bond reliability

Sellar, suprasellar, and parasellar masses: Imaging features and neurosurgical approaches

The sellar, suprasellar, and parasellar space contain a vast array of pathologies, including neoplastic, congenital, vascular, inflammatory, and infectious etiologies. Symptoms, if present, include a combination of headache, eye pain, ophthalmoplegia, visual field deficits, cranial neuropathy, and endocrine manifestations. A special focus is paid to key features on CT and MRI that can help in differentiating different pathologies. While most lesions ultimately require histopathologic evaluation, expert knowledge of skull base anatomy in combination with awareness of key imaging features can be useful in limiting the differential diagnosis and guiding management. Surgical techniques, including endoscopic endonasal and transcranial neurosurgical approaches are described in detail

Wirelessly addressable heater array for centrifugal microfluidics and escherichia coli sterilization

Localized temperature control and heater interface remain challenges in centrifugal microflu idics and integrated lab-on-a-chip devices. This paper presen ts a new wireless heating method that enables selective acti vation of micropatterned resonant heaters using external radi ofrequency (RF) fields and its applications. The wireless heat ers in an array are individually activated by modulating the freque ncy of the external field. Temperature of 93 ° °° ° C is achieved in the heater when resonated with a 0.49-W RF output power. The w ireless method is demonstrated to be fully effective for he ating samples under spinning at high speeds, showing its applicab ility to centrifugal systems. Selective sterilization of Escherichia coli through the wireless heating is also demonstrated. Healthcare applications with a focus on wound sterilization ar e discussed along with preliminary experiments, showing promisi ng results