Current Generation Of Devices Research Articles

Study on the influence of ship waves on the dynamic response of floating tidal current power generation device

To study the influence of ship traveling waves on the hydrodynamic performance between the carrier platform and the turbine, the computational fluid dynamics method and the DFBI motion module of STAR CCM+ software were adopted. Under the condition of the coupling of the ship traveling wave and wave current generated at different speeds, the overall motion response of the power plant is simulated. What’s more, the influence of different wave conditions on the heave, pitch, and roll of the carrier platform and the energy efficiency of the turbine is analyzed. The results show that the ship speed has little effect on the carrier heave motion, but the maximum value of the carrier pitch motion increases with the increase in the ship speed. The value of turbine energy acquisition efficiency always decreases with decreasing lateral spacing and increases with decreasing speed. This paper has a certain reference value for the engineering application of floating tidal current power generation equipment.

Transcatheter Left Atrial Appendage Closure: Devices Available, Pitfalls, Advantages, and Future Directions.

Transcatheter left atrial appendage closure has emerged as a non-pharmacological alternative to long-term anticoagulation for stroke prevention in appropriately selected patients with AF. In this concise review, the Food and Drug Administration-approved and some other left atrial appendage closure devices that are under investigation are discussed. Currently, Watchman Flx and Amplatzer Amulet are the only two devices that have been approved for commercial use by the Food and Drug Administration. A brief overview of device designs, clinical data on efficacy and safety, major limitations of left atrial appendage closure devices, and perspectives on future direction are provided. The current generation of devices is effective; however, efforts should continue on innovations and refinement of device technology.

Enhancing moisture-electric power generation through in situ incorporation of carbon dots into polyelectrolyte membrane

The electric generation performance of traditional polyelectrolyte membrane with moisture usually fall far behind expectations due to its limited hydrophilic groups and poor directional transport capacity of protons. To this end, we introduce the suspension of carbon dots (CDs) prepared by selective oxidation etching of coal pitch with the mixture of formic acid and H2O2 under ambient temperature into the aqueous solution of polyvinyl alcohol (PVA) and poly(4-styrensulfonic acid) (PSS) to fabricate a novel hybrid membrane. This membrane (1.00 cm2) continuously delivers a voltage output of 0.83 V with a short-circuit current of 5.20 μA under proper moist conditions over a prolonged period, outperforming the power generation performance of the pristine membrane and many current moisture-enabled electric generation (MEG) devices. Moreover, CDs endow the polymer membrane with more superior mechanical properties, in favor of processing and scale integration for higher power output. With excess hydrophilic groups provided by as-prepared CDs’ suspension, the denser hydrogen-bond network can be formed in the membrane and facilitates water adsorption and the formation of a higher proton concentration gradient. CDs-induced bridging interactions between PSS chains pave a fast directional transport pathway for moveable protons, resulting in a remarkable power output. Accordingly, this work offers a facile and economic method for remoulding traditional polyelectrolyte membrane to conduct highly efficient MEG for practical applications.

Real-World Comparison of Transcatheter Versus Surgical Aortic Valve Replacement in the Era of Current-Generation Devices.

Few studies have reported comparisons of out-of-hospital clinical outcomes after transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis (AS) in the era of current-generation valves that reflect the real-world situation. Data on patients with severe AS aged 65 years or older who underwent TAVR or SAVR between 2015 and 2018 were obtained from the National Health Insurance Service in Korea and clinical event rate was analyzed. The primary endpoint was all-cause death at 1 year. The cohort included a total of 4623 patients over 65 years of age, of whom 1269 (27.4%) were treated with TAVR. After 1:1 propensity score matching, 2120 patients were included in the study. TAVR was associated with reduced 1-year mortality (hazard ratio (HR): 0.55; 95% confidence interval (CI): 0.42-0.70; p < 0.001). There was no difference between the groups in the incidence of ischemic stroke (HR: 0.72, 95% CI: 0.43-1.20; p = 0.21) and intracranial hemorrhage (HR: 1.10; p = 0.74). Permanent pacemaker insertion was observed more frequently in the TAVR cohort (9.4% vs. 2.5%, HR: 3.95, 95% CI: 2.57-6.09; p < 0.001), whereas repeat procedures were rare in both treatments (0.5% vs. 0.3%, p = 0.499). In the nation-wide real-world data analysis, TAVR with current-generation devices showed significantly lower 1-year mortality compared to SAVR in severe AS patients.

Structural and Electrotransport Properties of Perfluorinated Sulfocationic Membranes Modified by Silica and Zirconium Hydrophosphate.

A correlation between changes in structural and electrotransport properties of membranes after modification by silica and zirconium hydrophosphate was established. The total water volume, volume fraction of the free water in the membrane and the volume fraction of the water having high binding energy were considered as structural characteristics, which were found from the curves of water distribution on the water binding energy and the effective pore radii. The conductivity, diffusion and electroosmotic permeabilities were investigated as electrotransport properties. The influence of the modifier type on the current flow paths in the membrane was analyzed within the framework of the extended three-wire model. It has been established that the treatment of membranes with alcohol before the intercalation of a modifier leads to the appearance of cavities with an effective size of more than 100 nm filled with free water with the binding energy less than 10 J/mol. It is accompanied with an increase in the diffusion permeability of hybrid membranes by approximately 3–6 times in NaCl and HCl solutions, which limits the application of such materials in proton exchange membrane fuel cells. The different conditions of modification of perfluorinated membranes with similar properties by the dopant with same type allow for the preparation of the hybrid materials for various applications such as electrodialysis concentration or electric current generation devices.

The 10-year horizon: Survival and structural valve degeneration in first-generation transcatheter aortic valves

Transcatheter aortic valve replacement is an established treatment for high- or intermediate-risk patients with symptomatic aortic valve stenosis. As more low-risk patients are being treated, transcatheter heart valve durability is gaining importance. Data on structural valve deterioration beyond 8 years after transcatheter aortic valve replacement is limited. To evaluate the outcomes of transcatheter aortic valve replacement in high-risk patients with a follow-up of ≥10 years, focusing on survival and structural valve deterioration, according to the European Association of Percutaneous Cardiovascular Interventions/European Society of Cardiology/European Association for Cardio-Thoracic Surgery definitions. Only patients with a follow-up of ≥ 10 years were included in this study (n=510). Using serial echocardiographic data, the cumulative incidences of structural valve deterioration and bioprosthetic valve failure were analysed. Receiver operating characteristic analysis was used for predictor assessment. Mean age was 79.6±6.7 years, with a mean logistic EuroSCORE of 19.8±12.7%. Immediate procedural mortality was 2.9%, and 30-day mortality was 7.8%. Kaplan-Meier-estimated survival at 10 years was 10.3±1.5%. At 10 years, the cumulative incidences of severe and moderate structural valve deterioration were 4.3% and 13%, respectively, for the total population. The cumulative incidence of bioprosthetic valve failure at 10 years was 9.0%. There was a significant difference in the rates of structural valve deterioration and bioprosthetic valve failure depending on valve type: structural valve deterioration, SAPIEN 8.9% vs CoreValve 2.2% at 10 years (P=0.001); bioprosthetic valve failure, SAPIEN 13.9% vs CoreValve 6.7% at 10 years (P=0.021). Structural valve deterioration and bioprosthetic valve failure of early transcatheter heart valves was low at 10 years. The identified differences between valve types must be validated using current-generation devices in younger patients.

Patient-Specific Computer Simulation to Predict Conduction Disturbance With Current-Generation Self-Expanding Transcatheter Heart Valves

BackgroundPatient-specific computer simulation may predict the development of conduction disturbance following transcatheter aortic valve replacement (TAVR). Validation of the computer simulations with current-generation devices has not been undertaken. MethodsA retrospective study was performed on patients who had undergone TAVR with a current-generation self-expanding transcatheter heart valve (THV). Preprocedural computed tomography imaging was used to create finite element models of the aortic root. Procedural contrast angiography was reviewed, and finite element analysis performed using a matching THV device size and implantation depth. A region of interest corresponding to the atrioventricular bundle and proximal left bundle branch was identified. The percentage of this area (contact pressure index [CPI]) and maximum contact pressure (CPMax) exerted by THV were recorded. Postprocedural electrocardiograms were reviewed, and major conduction disturbance was defined as the development of persistent left bundle branch block or high-degree atrioventricular block. ResultsA total of 80 patients were included in the study. THVs were 23- to 29-mm Evolut PRO (n = 53) and 34-mm Evolut R (n = 27). Major conduction disturbance occurred in 27 patients (33.8%). CPI (28.3 ± 15.8 vs. 15.6 ± 11.2%; p < 0.001) and CPMax (0.51 ± 0.20 vs. 0.36 ± 0.24 MPa; p = 0.008) were higher in patients who developed major conduction disturbance. CPI (area under the receiver operating characteristic curve [AUC], 0.74; 95% CI, 0.63-0.86; p < 0.001) and CPMax (AUC, 0.69; 95% CI, 0.57-0.81; p = 0.006) demonstrated a discriminatory power to predict the development of major conduction disturbance. ConclusionsPatient-specific computer simulation may identify patients at risk for conduction disturbance after TAVR with current-generation self-expanding THVs.

Impact of sigmoid septum on periprocedural outcomes following transcatheter aortic valve implantation using current-generation valves.

The role of sigmoid septum (SS) observed using preprocedural transthoracic echocardiography (TTE) in patients undergoing transcatheter aortic valve implantation (TAVI) remains unknown. This study aimed to compare clinical outcomes of TAVI using the current-generation transcatheter heart valves in patients with and without SS. We divided 140 consecutive patients, excluding four patients who underwent pacemaker implantation before TAVI, into two groups (those with and without SS) and compared the periprocedural outcomes, including new pacemaker implantation, within 30days post-TAVI. Thirty-five patients (25%; 32 female patients) had SS before TAVI. The body surface area and aortic annulus area measured using computed tomography were significantly smaller in patients with SS than in those without SS (1.40 m2 vs. 1.48 m2, P = 0.03; and 372 mm2 vs. 409 mm2, P < 0.01; respectively). Device success was achieved in all patients with SS. Postprocedural TTE on 30days post-TAVI showed no significant differences in the valvular hemodynamics between patients with and without SS. No severe prosthesis-patient mismatch was noted on TTE, although the transcatheter heart valve size tended to be smaller in patients with SS. Within 30days of the TAVI, three (8.6%) and eight (7.6%) patients with and without SS, respectively, had new pacemaker implantation (P = 0.86). The presence of SS was not associated with periprocedural outcomes following TAVI in patients without pre-existing pacemakers. No specific assessment or treatment strategy is required for the TAVI in patients with SS using the current-generation devices.

B-PO01-097 DO APPLE IPHONE 12 MAGSAFE MAGNETS TRIGGER MAGNET MODE IN CARDIAC DEVICES?

Cardiac devices (pacemaker and defibrillators) have a magnet sensitive switch. Magnet application on a pacemaker generally causes an asynchronous pacing mode. Magnet application on a defibrillator temporarily suspends all anti-tachycardia therapies. Suspending anti-tachycardia therapies on a defibrillator can result in inhibition of potential life-saving therapies. The new Apple iPhone 12 line contain new magnets as part of their MagSafe charging system. Apple has recently released a warning for their iPhone 12 series and MagSafe accessories to keep a safe distance of more than 6 inches away from cardiac devices. This study aims to study the safety of Apple iPhone 12 with MagSafe near cardiac devices and to see how often then may trigger magnet mode. During clinic device checks or in hospital new cardiac device implant or generator changes, an Apple iPhone 12 with MagSafe cover will be used to see if magnet mode can be triggered on the cardiac device. Three sites were tested (<6 inches), holding the phone near the mouth, near the ear on the cardiac device implanting side and physically on top of the device. Magnet mode was first confirmed by using a standard medical grade device magnet while connected to an ECG or device interrogator. The Apple iPhone 12 with MagSafe cover was tested at 3 different sites to see if magnet mode could be triggered. The Apple iPhone 12 was tested on 30 devices for a total of 90 different positions. Manufacturer breakdown was 18 from Abbott, 10 from Medtronic and 2 from Boston Scientific. Device type breakdown was 20 pacemakers, 10 transvenous ICD and 1 SubQ ICD. Magnet response occurred in 0/30 near mouth position, 0/30 ear position and 3/30 over the device position. The 3 magnet responses were on Abbott pacemakers. One magnet response was easy to induce on an older generation of Abbott CRT pacemaker before generator change. The other 2 magnet responses were on current generation of Abbott pacemakers but was very positional. Apple iPhone 12 with MagSafe can be safely used with cardiac devices in normal phone use. Even with extreme close contact, only 10% of the time we were able to elicit magnet response. On current generation of devices, it was very positional to elicit magnet response.

The Effect Of Calcium Score On Aortic Regurgitation Post Transcatheter Aortic Valve Replacement

Introduction: As transcatheter aortic valve replacements (TAVR) becomes more common in lower risk populations, the importance of even mild post-procedural paravalvular aortic regurgitation (AR) becomes more important. A very high Agatson calcium score (CS) of the aortic valve has been shown to be an independent prognostic factor for ≥ moderate aortic regurgitation post TAVR, however, the predictive value of CS for mild AR is not known. Furthermore, the evidence mainly refers to older TAVR valve models; new TAVR valve models have much lower rates of AR, and the evidence of calcium scoring to predict AR in these devices is limited. Our aim was to study the relationship of valve calcium and paravalvular AR in the current generation of devices.

Design and performance evaluation of a submerged floating tidal current power generation device

Due to the difficulty and high cost of offshore power supply, there are still many remote islands which have not been fully developed and utilized. In order to solve this kind of problem, a new type of marine current turbine (MCT) power generation device was designed for Tuoji Island, Changdao County, Shandong Province, which is convenient for installation and maintenance. This paper presents both the prototype design and model test verification work. Limited by the size of circulating water channel, the test model was modeled and manufactured under the scale of 3:100, which means the turbine model is not able to meet the small scale geometry similarity and gravity equivalent at the same time. A light circular plate was designed to replace the resistance of the turbine as equal by means of CFD. Then it combines the main body and the equivalent disc to complete the mooring test, observing the attitude response of the device under different angles of current. On the basis, the hydrodynamic performance of the whole device model was observed under different inflow speeds and angles. The results of the model tests indicated that the prototype is relatively stable under the design condition.

CMOS series-shunt single-pole double-throw transmit/receive switch and low noise amplifier design for internet of things based radio frequency identification devices

The incompatibility between current RFID standards has led to the need for universal and Wi-Fi compatible RFID for IoT applications. Such a universal RFID requires an SPDT and an LNA to direct and amplify the received raw signal by the antenna. The SPDT suffers from low isolation, high insertion loss and low power handling capacity whereas the LNA suffers from bulky die area, lesser Q factor, limited tuning flexibility etc. because of passive inductor usage in current generation of devices. In this research, nano-CMOS inductorless SPDT and LNA designs are proposed. The SPDT adopts a series-shunt topology along with parallel resonant circuits and resistive body floating in order to achieve improved insertion loss and isolation performance whereas the LNA design is implemented with the gyrator concept in which the frequency selective tank circuit is formed with an active inductor accompanied by the buffer circuits. The post-layout simulation results, utilizing 90nm CMOS process of cadence virtuoso, exhibit that our SPDT design accomplishes 0.83dB insertion loss, a 45.3dB isolation, and a 11.3dBm power-handling capacity whereas the LNA achieves a peak gain of 33dB, bandwidth of 30MHz and NF of 6.6dB at 2.45GHz center frequency. Both the SPDT and LNA have very compact layout which are 0.003mm 2 and 127.7 μm 2 , respectively. Such SPDT and LNA design will boost the widespread adaptation of Wi-Fi-compatible IoT RFID technology.

Progressive Dynamic Time Warping for Noninvasive Blood Pressure Estimation

Abstract Arterial blood pressure is one of the most important cardiovascular parameters. Yet, current-generation devices for continuous, noninvasive acquisition are few, expensive and bulky. Novel signal processing applied to easily acquired unimodal signals can alleviate this issue, reducing size, cost and expanding the use of such devices to ambulatory, everyday settings. The features of pulse waves acquired by photo- or impedance-plethysmography can be used to estimate the underlying blood pressure. We present a progressive dynamic time warping algorithm, which implicitly parametrizes the morphological changes in these waves. This warping method is universally applicable to most pulse wave shapes, as it is largely independent of fiducial point detection or explicit parametrization. The algorithm performance is validated in a feature selection and regression framework against a continuous, noninvasive Finapres NOVA monitor, regarding systolic, mean and diastolic pressures during a light physical strain test protocol on four clinically healthy subjects (age18- 33, one female). The obtained mean error is 2.13 mmHg, the mean absolute error is 5.4 mmHg and the standard deviation is 5.6 mmHg. These results improve on our previous work on dynamic time warping. Using single-sensor, peripherally acquired pulse waves, progressive dynamic time warping can thus improve the flexibility of noninvasive, continuous blood pressure estimation.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Bicuspid Aortic Valve Disease: A Report From the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.

Patients with bicuspid aortic valve (AV) stenosis were excluded from the pivotal evaluations of transcatheter AV replacement (TAVR) devices. We sought to evaluate the outcomes of TAVR in patients with bicuspid AV stenosis in comparison with those with tricuspid AV stenosis. We used data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry (November 2011 through November 2018) to determine device success, procedural outcomes, post-TAVR valve performance, and in-hospital clinical outcomes (mortality, stroke, and major bleeding) according to valve morphology (bicuspid versus tricuspid). Results were stratified by older and current (Sapien 3 and Evolut R) generation valve prostheses. Medicare administrative claims were used to evaluate mortality and stroke to 1 year among eligible individuals (≥65 years). After exclusions, there were 170 959 eligible procedures at 593 sites during the specified interval. Of these, 5412 TAVR procedures (3.2%) were performed in patients with bicuspid AV, including 3705 with current-generation devices. In comparison with patients with tricuspid valves, patients with bicuspid AV were younger and had a lower Society of Thoracic Surgeons Predicted Risk of Operative Mortality score. When current-generation devices were used to treat patients with bicuspid AV, device success increased (93.5 versus 96.3; P=0.001) and the incidence of 2+ aortic insufficiency declined (14.0% versus 2.7%; P<0.001) in comparison with older-generation devices. With current-generation devices, device success was slightly lower in the bicuspid (versus tricuspid) AV group (96.3% in bicuspid versus 97.4% in tricuspid, P=0.07), with a slightly higher incidence of residual moderate or severe aortic insufficiency among patients with bicuspid AV (2.7% versus 2.1%; P<0.001). A lower 1-year adjusted risk of mortality (hazard ratio, 0.88 [95% CI, 0.78-0.99]) was observed for patients with bicuspid AV versus patients with tricuspid AV in the Medicare-linked cohort, whereas no difference was observed in the 1-year adjusted risk of stroke (hazard ratio, 1.14 [95% CI, 0.94-1.39]). Using current-generation devices, procedural, postprocedural, and 1-year outcomes were comparable following TAVR for bicuspid AV versus tricuspid AV disease. With newer-generation devices, TAVR is a viable treatment option for patients with bicuspid AV disease.

Mid-term outcome in patients with bicuspid aortic valve stenosis following transcatheter aortic valve replacement with a current generation device: A multicenter study.

To perform clinical and echocardiographic follow-up beyond 1 year in consecutive patients with severe bicuspid aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) with a current generation balloon-expandable valve. Treatment of bicuspid aortic valve disease with TAVR remains controversial and late follow-up data is still scarce. We collected baseline characteristics, procedural data, 30-day and mid-term clinical follow-up findings from six centers in Europe and Canada from patients with bicuspid AS treated with TAVR using the SAPIEN 3 valve. Seventy-nine patients underwent TAVR. Mean age was 76 ± 9 years; median STS risk score for mortality was 3.8% (interquartile range 2.3-5.5%). Median follow-up was 390 days (interquartile range 138-739 days). Device success was achieved in 95% of patients. Postimplantation mean aortic gradient decreased from 50.2 ± 16.2 to 8.8 ± 4.4 mmHg and no patient had more than mild aortic regurgitation. At last follow-up, there was persistent good valve performance. At 30 days and 1 year, the rates of all-cause mortality were 3.8 and 7.7%, stroke 1.2 and 1.2%, and the rate of new pacemakers 18 and 18%. Our data confirm that treating patients with stenotic bicuspid aortic valves is safe, effective, and has favorable valve performance over time.

Toward fast, low-noise charge-coupled devices for Lynx

Lynx requires large-format x-ray imaging detectors with performance at least as good as the best current-generation devices but with much higher readout rates. We are investigating an advanced charge-coupled device (CCD) detector architecture under development at MIT Lincoln Laboratory for use in the Lynx high-definition x-ray imager and x-ray grating spectrometer instruments. This architecture features a CMOS-compatible detector integrated with parallel CMOS signal processing chains. Fast, low-noise amplifiers and highly parallel signal processing provide the high frame rates required. CMOS-compatibility of the CCD enables low-power charge transfer and signal processing. We report on the performance of CMOS-compatible test CCDs read at pixel rates up to 5.0 Mpix s − 1 (50 times faster than Chandra ACIS CCDs), with transfer clock swings as low as 1.0-V peak-to-peak (power/gate-area comparable to ACIS CCDs at 100 times the parallel transfer rate). We measure read noise of 4.6 electrons RMS at 2.5 MHz and x-ray spectral resolution better than 150-eV full-width at half maximum at 5.9 keV for single-pixel events. We report charge transfer efficiency measurements and demonstrate that buried channel trough implants as narrow as 0.8 μm are effective in improving charge transfer performance. We find that the charge transfer efficiency of these devices drops significantly as detector temperature is reduced from ∼ − 30 ° C to −60 ° C. We point out the potential of previously demonstrated curved-detector fabrication technology for simplifying the design of the Lynx high-definition imager. We discuss the expected detector radiation tolerance at these relatively high transfer rates. Finally, we note that the high pixel “aspect ratio” (depletion depth: pixel size ≈9 ∶ 1) of our test devices is similar to that expected for Lynx detectors and discuss implications of this geometry for x-ray performance and noise requirements.

Assessment of Alcohol Use in the Natural Environment.

The current article critically reviews 3 methodological options for assessing drinking episodes in the natural environment. Ecological momentary assessment (EMA) typically involves using mobile devices to collect self-report data from participants in daily life. This technique is now widely used in alcohol research, but investigators have implemented diverse assessment strategies. This article focuses on "high-resolution" EMA protocols that oversample experiences and behaviors within individual drinking episodes. A number of approaches have been used to accomplish this, including using signaled follow-ups tied to drinking initiation, asking participants to log entries before and after individual drinks or drinking episodes, and delivering frequent signaled assessments during periods of the day when alcohol use is most common. Transdermal alcohol sensors (TAS) are devices that are worn continuously and are capable of detecting alcohol eliminated through the skin. These methods are appealing because they do not rely upon drinkers' self-report. Studies using TAS have been appearing with greater frequency over the past several years. New methods are making the use of TAS more tractable by permitting back-translation of transdermal alcohol concentration data to more familiar estimates of blood alcohol concentration or breath alcohol concentration. However, the current generation of devices can have problems with missing data and tend to be relatively insensitive to low-level drinking. An emerging area of research investigates the possibility of using mobile device data and machine learning to passively detect the user's drinking, with promising early findings. EMA, TAS, and sensor-based approaches are all valid, and tend to produce convergent information when used in conjunction with one another. Each has a unique profile of advantages, disadvantages, and threats to validity. Therefore, the nature of the underlying research question must dictate the method(s) investigators select.

Design of Blade for Horizontal-Shaft Ocean Current Generation Device

Ocean current energy has become an important development direction of renewable energy and has broad application prospects. At present, most of the research on the energy of the current is on the improvement of the generator structure and the design of the blade, but the design of the blade is mostly the design of the wind turbine, which fails to meet the optimal condition of ocean currents. This paper aims at the development and utilization of ocean current energy, compares the application environment of wind turbines and ocean currents, and designs a blade suitable for ocean current energy generation devices. Through CFD simulation and PROFILI selection of blade airfoiled, the curve of the Lift-to-drag ratio with the angle of attack is obtained, and other parameters of the blade are obtained by solving the Wilson method through MATLAB. Finally, the 3D modeming is carried out by SolidWorks.

Potential Induction Heating using MOSFET H-Bridge Circuit for Material Synthesis

Here we report our effort to integrate microcontroller to control AC current-generating MOSFET H-bridge circuit-based device. We have carried out the tests of the potential application of the induction heating generated by the device for material synthesis by controlling the variation of AC current at constant frequency value. The results showed that at the constant frequency value, the heating process depended on the amount of AC current. The different responses of different kind of materials to the different frequencies at constant AC current value have also been observed. The results provide the fundamental base for further development of induction heating furnace using microcontroller based AC current generation device.

A Review on Low-Grade Thermal Energy Harvesting: Materials, Methods and Devices.

Combined rejected and naturally available heat constitute an enormous energy resource that remains mostly untapped. Thermal energy harvesting can provide a cost-effective and reliable way to convert available heat into mechanical motion or electricity. This extensive review analyzes the literature covering broad topical areas under solid-state low temperature thermal energy harvesting. These topics include thermoelectricity, pyroelectricity, thermomagneticity, and thermoelasticity. For each topical area, a detailed discussion is provided comprising of basic physics, working principle, performance characteristics, state-of-the-art materials, and current generation devices. Technical advancements reported in the literature are utilized to analyze the performance, identify the challenges, and provide guidance for material and mechanism selection. The review provides a detailed analysis of advantages and disadvantages of each energy harvesting mechanism, which will provide guidance towards designing a hybrid thermal energy harvester that can overcome various limitations of the individual mechanism.