Estimation and measurement of effective line mobility on a non-deterministic thin plate excited by a piezoelectric patch

This paper derived the expression to estimate the effective line moment mobility of a non-deterministic thin plate under moment excitation by a piezoelectric patch actuator. The piezoelectric patch actuator is assumed to generate purely line moments at each of its edges and regarded as a finite number of point moments acting on an infinite plate, which is achieved by integration method. The theoretical model is validated using MATLAB simulation and compared with experimental measurements on a randomized thin plate. The derived effective line moment mobility managed to closely estimate high-frequency response while cutting significant computational time and resource. Results from this study can be used in many applications ranging from vibration isolation where power transmission between the isolator with an area distribution and its host structure can be determined more accurately, and to design the optimal shunt circuit of a piezoelectric shunt damper for maximum power dissipation in order to reduce vibration of a non-deterministic thin plate

Dynamic effects of piezoelectric patch actuators on vibrational response of non-deterministic structures: modelling and simulations

Many engineering systems such as aircraft and automotive are considered built-up structures, fabricated from components that are classi fi ed as deterministic subsystems (DS) and non-deterministic subsystems (Non-DS). The response of Non-DS is sensitive to minor details of material properties, geometry, connections and damping distribution; therefore create problems in vibration control. Hence, the response of Non-DS is estimated using statistical modelling technique such as sta- tistical energy analysis (SEA), in which any external input to the subsystem must be represented in terms of power input. In this research, ensemble average of power delivered by a piezoelectric (PZT) patch actuator to a simply-supported plate when subjected to structural uncertainties is studied using Lagrangian method and obtained by Monte-Carlo simulation. The effects of size and location of the PZT patch actuators on the power delivered to the plate are investigated. It is found that changing the patch location on the structure will not affect the average power sup- plied by the patch while changing the patch size will change the power magnitude proportionally but with some variations at higher frequency

FRGS15-165-0406: MATHEMATICAL ANALYSIS TO ESTIMATE OPTIMAL SHUNT IMPEDANCE FOR PIEZOELECTRIC TRANSDUCER TO MAXIMIZE VIBRATION ENERGY DISSIPATION IN NON-DETERMINISTIC SUB-SYSTEMS

Engineering systems such as aircrafts, ships and automotive are built-up structures fabricated from many components that can be classified as deterministic substructure (DS) and non-deterministic substructure (Non-DS). Non-DSs are subjected to high-frequency vibration which produced response that cannot be described mathematically using deterministic method. This makes vibration energy harvesting tricky due to the combined modal response which produce no visible distinct peaks. Piezoelectric (PZT) transducer connected to a shunt circuit is an attractive choice to harvest vibration energy from a Non-DS. Using Hybrid modelling equation, the impedance of the circuit to be attached to the Non-DS needs to be complex conjugate of the impedance faced by the Non-DS at its connection point. The shunt circuit of the PZT shunt harvester is designed such that the impedance is complex conjugate of its inherent capacitance parallel with impedance faced by the host structure at the connection area. In the first part of this research, the impedance faced by the Non-DS at the connection area is estimated using effective line mobility of an infinite thin plate under moment excitation by a square PZT patch using double integration of the infinite mobility which resulted to a hypergeometric function. The analytical model is compared with the average response of a randomized finite thin plate via Monte Carlo simulation which managed to significantly cut computational time to ~40 times shorter compared to using the finite method. Using findings from this part, the implementation of the designed shunt circuit using electronic components is carried out. One possible circuit configuration that closely resembles the theoretical impedance derived is realized by application of two negative impedance converters (NICs) utilizing op-amps, in order to replicate the negative capacitance, C and negative RL in series

Analysis of mutual inductance and coupling factor of inductively coupled coils for wireless electricity

A basic analysis of inductive coils and its parameter calculations are presented. The simulations of mutual inductance, coupling factor calculations are demonstrated with graphical analysis. Three different lab-scale coil models such as square, circular and rectangular coils are wounded to evaluate the magnetic field by experiment, to validate the performance of Wireless Power System (WPT). In the open literature, circular coils are employed in most of the works, but few works have been reported in the parameter analysis. Further investigations on parameter exploration seems as a prerequisite for magnetic field measurement by estimating the parameters such as mutual inductance(M), coupling factor(k), magnetic flux(Φ) and magnetic field(B). It helps us to select the coils according to the applications. In this work, it is observed that circular performs well than other shaped coils in terms of parametrical analysis which are mentioned above. The simulation, and experimental results are tabulated as well as supported graphical plots are shown as proving circular coils performs well in the WPT scenario. Keywords: coupling factor, mutual inductance, magnetic field, inductive coils, wireless power transfer

General Analysis of Resonance Coupled Wireless Power Transfer (WPT) Using Inductive Coils

In this paper, parameter analysis of the inductive coils is evaluated for low power Wireless Power Transfer (WPT) applications. Inductive coils are the major element used in the WPT systems, in which different shaped coils are employed. The selection of coils is very critical, depends purely on the fundamental characteristics (shape and geometry) of the coils. In order to design a better system, three different shapes of coils, namely, circular, square and rectangular are designed and analysed. The vital parameters such as self-inductance, mutual inductance, quality factor, magnetic field and efficiency are evaluated for all three coils. It is observed that these parameters are maximal for circular as compared to the other two shapes. The circular coils produce higher voltage efficiency of 29% as compared to rectangular (25%) and square (23%) shaped coils. Thus, this paves a way to other researchers to suitably select circular inductive coils for wireless electricity applications

A New Probiotic Candidate Bacterium from Human Milk: Limosilactobacillus vaginalis MA-10

The probiotic and technological potentials of lactic acid bacteria originating from human milk are becoming a remarkable research area. In the present study, Limosilactobacillus vaginalis MA-10 isolated from human milk was investigated in vitro for its probiotic and technological aspects. According to the results obtained in the study, MA-10 strain exhibited non-haemolytic activity and various degrees of sensitivity to most of the tested antibiotics. The strain showed good resistance to the gastrointestinal system and maintained its viability under these conditions. Its antimicrobial activity against human or clinical bacterial and fungal microorganisms and fish bacteria was determined in the range of 2.38–11.22 mm. The MA-10 strain was able to assimilate cholesterol ranging from 31.42 to 82.30%. The strain showed 9.34% ferrous-ion chelating and 32% DPPH free radical scavenging activities. These initial results from the present study confirm that L. vaginalis MA-10 may be a new source with appropriated probiotic and technological traits for various industries, and further in vivo assays. Due to the limited number of studies on L. vaginalis strains originated from human breast milk in the literature, the data obtained in this study are thought to be important for revealing the basic probiotic properties of the strain

Animal sound activity detection using multi-class support vector machines

On March 11th 2011, the whole world was taken aback by another tragic experience of Tsunami triggered by a magnitude 9.8 earthquake in Japan. Just few days after that, on March 25th 2011, another earthquake of magnitude 6.8 hit Myanmar deaths and destructions. Despite the loss incurred on properties and human being, available data show that relatively few numbers of animals died during most natural disasters. Prior to the occurrence of these disasters, available reports shows that animals do migrate to higher level or leave the areas en masse ahead of the event. Other related account show that animal sometimes behaves in unusual ways prior to the occurrence of these natural disasters. These overwhelming evidences point to the fact that animals might have the ability to sense impending natural disaster precursor signals ahead of time. This paper discusses the preliminary results obtained from the use of support vector machine (SVM) and Mel-frequency cepstral coefficients (MFCC) in the development of animal sound activity detection (ASAD) which is an integral part in the development of earthquake and natural disaster prediction using unusual animal behavior. The use of MFCC has been proposed for the features extraction stage while SVM has been proposed for classification of the extracted features. Preliminary results obtained shows that the MFCC and SVM can be used for features extraction and features classification respectively

Intelligent glove for suppression of resting tremor in Parkinson’s disease

One of the significant symptoms in Parkinson’s disease is resting tremor. Resting tremor occurs when the muscle is relaxed, causing the limb to shake. Rhythmic muscle movement of the patients commonly happens within the range of 4 Hz to 6 Hz. Thus, reducing this type of tremor will help improve patients’ quality of life. In this paper, to suppress resting tremors, an intelligent glove was designed utilizing the concepts of vibrations and gyro effect. A rotating brass disc attached to the glove creates a gyroscopic effect of the smart glove. Therefore, the disc will do their utmost to stay upright and counter any input forces instantaneously by providing the counterforce. A reduction of more than 50 % with the intelligent glove is also shown

High Exhaustion Sytem (HES) for leather process: Role of biocatalyst as an exhaustive aid for wet-end

Content: Application of biocatalyst becomes an imperative due to their eco-friendly advantages. Enzymes in pretanning for unhairing, fiber opening, defleshing and bating are well reported and practiced. However, the role of enzymes as a chemical aids is less explored and consider as a secondary applications. Leather enzymes are known for its hydrolytic behavior which makes it more suitable for pretanning operations. However, typical chemical exhaustive aids acts as a vehicle for the diffusion of chemicals, whereas enzymes aids in the splitting of fibers which facilitate the diffusion of chemicals and create more functional sites for the tanning and post tanning chemicals to interact. In this research, pickled pelts are treated with acid protease and subsequently tanned using chrome tanning agent. Enzymatic treated pelts resulted in better uptake of chromium as compared to conventionally processed leathers. Similarly, after neutralization, chrome tanned leathers are treated with alkaline protease to conventional post tanning has been carried out. Enzymatic treated wet blue leathers showed high uptake of post tanning chemical, uniform dyeing and reduction in the pollution load. From the preliminary research, an interesting finding has augmented that application of enzymes at an optimized concentration, temperature, pH and time would lead to better uptake of chrome which reduces the pollution and minimization pollution load in post tanning. This study, emphasize on the application of enzymes in tanning and post tanning for higher diffusion of chemicals. Take-Away: 1. Replacement of conventional exhaustive aids using biocatalyst 2. Higher exhaustion rate of tanning and post tanning chemicals 3. Futuristic technology for sustainable leather manufactur

Optimal piezoelectric shunt dampers for non‑deterministic substructure vibration control: estimation and parametric investigation

Piezoelectric (PZT) shunt damping is an effective method to dissipate energy from a vibrating structure; however, most of the applications focus on targeting specific modes for structures vibrating at low-frequency range, i.e. deterministic substructure (DS). To optimally attenuate structures vibrating at high-frequency range, i.e. non-deterministic substructure (Non-DS) using a PZT shunt damper, it is found that the impedance of the PZT patch’s terminal needs to be the complex conjugate of its inherent capacitance paralleled with the impedance ‘faced’ by its non-deterministic host structure underline moment actuation. The latter was derived in terms of estimation of the effective line moment mobility of a PZT patch on a Non-DS plate by integrating the expression of driving point moment mobility of an infinite thin plate. This paper conducts a parametric investigation to study the effect of changing the size, quantity and configuration of the PZT patch to the performance of the optimal PZT shunt dampers in dissipating the energy of its non-deterministic host structure. Results are shown in terms of energy reduction ratio of the thin plate when attached with optimal PZT shunt damper(s)