Acitve noise control in three dimension enclosure using piezoceramics

Analysis and experiment are undertaken to attenuate the three dimension enclosure noise using piezoceramics. A flexible aluminium plate and five wood walls are constructed with clamped four edges conditions. Noise is generated by speaker and transmitted to the three dimension enclosure. Piezoceramics are used to control the noise inside. A microphone is put inside to monitor the noise. State space method is used to identify the system, the vibration mode and acoustic mode is also researched. Different arithmetic is used to control the noise inside. The sound pressure level reduction at selected point is observed

Rapid assessment of early biophysical changes in K562 cells during apoptosis determined using dielectrophoresis

Apoptosis, or programmed cell death, is a vital cellular process responsible for causing cells to self-terminate at the end of their useful life. Abrogation of this process is commonly linked to cancer, and rapid detection of apoptosis in vitro is vital to the discovery of new anti-cancer drugs. In this paper, we describe the application of the electrical phenomenon dielectrophoresis for detecting apoptosis at very early stages after drug induction, on the basis of changes in electrophysiological properties. Our studies have revealed that K562 (human myelogenous leukemia) cells show a persistent elevation in the cytoplasmic conductivity occurring as early as 30 minutes following exposure to staurosporine. This method therefore allows a far more rapid detection method than existing biochemical marker methods

A microencapsulation approach to design microbial seed coatings to boost wheat seed germination and seedling growth under salt stress

IntroductionSalt stress in seed germination and early seedling growth is the greatest cause of crop loss in saline-alkali soils. Microbial seed coating is an effective way to promote plant growth and salt resistance, but these coatings suffer from poor seed adhesion and low survival rates under typical storage conditions.MethodsIn this study, the marine bacterium Pontibacter actiniarum DSM 19842 from kelp was isolated and microencapsulated with calcium alginate using the emulsion and internal gelation method.ResultsCompared to unencapsulated seeds, the spherical microcapsules demonstrated a bacterial encapsulation rate of 65.4% and survival rate increased by 22.4% at 25°C for 60 days. Under salt stress conditions, the seed germination percentage of microcapsule-embedded bacteria (M-Embed) was 90%, which was significantly increased by 17% compared to the germination percentage (73%) of no coating treatment (CK). Root growth was also significantly increased by coating with M-Embed. Chlorophyll, peroxidase, superoxide dismutase, catalase, proline, hydrogen peroxide and malondialdehyde levels indicated that the M-Embed had the best positive effects under salt stress conditions.DiscussionTherefore, embedding microorganisms in suitable capsule materials provides effective protection for the survival of the microorganism and this seed coating can alleviate salt stress in wheat. This process will benefit the development of sustainable agriculture in coastal regions with saline soils

Carbon nanotube based X-ray sources: Applications in pre-clinical and medical imaging

Field emission offers an alternate method of electron production for Bremsstrahlung based X-ray tubes. Carbon nanotubes (CNTs) serve as very effective field emitters, allowing them to serve as electron sources for X-ray sources, with specific advantages over traditional thermionic tubes. CNT derived X-ray sources can create X-ray pulses of any duration and frequency, gate the X-ray pulse to any source and allow the placement of many sources in close proximity.We have constructed a number of micro-CT systems based on CNT X-ray sources for applications in small animal imaging, specifically focused on the imaging of the heart and lungs. This paper offers a review of the pre-clinical applications of the CNT based micro-CT that we have developed. We also discuss some of the current and potential clinical applications of the CNT X-ray sources

Prospective Respiratory Gated Carbon Nanotube Micro Computed Tomography

Challenges remain in the imaging of the lungs of free-breathing mice. Though computed tomography (CT) is near optimal from a contrast perspective, the rapid respiration rate, limited temporal resolution and inflexible x-ray pulse control of most micro-CT (mCT) scanners limits their utility in pulmonary imaging. Carbon nanotubes (CNTs) have permitted the development of field emission cathodes, with rapid switching and precise pulse control. The goal of this study was to explore the utility of a CNT-based mCT for application in quantitative pulmonary imaging