Limited Lifetime Research Articles

Adaptive Mode Transformation for Wear Leveling in Nonvolatile FPGAs

Nowadays, field programmable gate arrays (FPGAs) have been widely adopted to serve as accelerators in artificial intelligence and big data related applications. Since the static random access memory (SRAM)-based FPGA is suffering from limited density and high leakage power, nonvolatile FPGAs have been proposed, where SRAM is replaced with emerging nonvolatile memories (NVMs). Multilevel cell (MLC), which can store multiple bits within one memory cell, further improves the density of nonvolatile FPGAs and shows great potential to enable large on-chip memory. However, it suffers from limited lifetime. In this article, we propose a wear leveling scheme to improve lifetime of MLC-based nonvolatile FPGAs. Instead of generating a series of configuration files for runtime reconfiguration, we propose to identify write-heavy MLC regions and dynamically transform them to durable single-level cell (SLC) mode. Specifically, we propose three modules: 1) pertaining to write behavior monitor; 2) approximate cost calculator; and 3) mode transformation manager to achieve adaptive mode transformations. We consider FPGA features to design these modules, which is different from implementations for MLC-SLC transformation in CPU architecture. Evaluation shows that the proposed scheme can improve lifetime for MLC nonvolatile FPGAs by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$6.03\times $ </tex-math></inline-formula> , at cost of 12.5% storage overhead.

JRCS: Joint Routing and Charging Strategy for Logistics Drones

Unmanned aerial vehicles (UAVs), commonly known as drones, are currently being used to combat the COVID-19 pandemic through applications, including the delivery of medical supplies, aerial spraying, and public space monitoring. In a pandemic, drone-based delivery is a promising and highly efficient method to reduce transportation time, cost, and exposure to infection. However, owing to both the limited battery lifetime and the limited functions of UAV in-flight missions, it is difficult to implement multiple deliveries over long distances in a single transportation mission. In this article, we study how to extend the drone flight time with charging stations and ensure multiple deliveries in a single mission. For multiple long-distance deliveries, optimization methods are required to design the delivery area networks of customers, charging stations, and delivery routes. We propose a joint routing and charging strategy (JRCS) comprising three phases to perform multiple deliveries in a single mission. We first split the customers of a delivery area using a clustering algorithm according to their distance from the nearest charging station and the maximum flight range. The second phase provides flight segmentation and intersegment routes between the depot, customer locations, and charging stations based on the maximum flight range and safe flight distance. The joint consideration of drone routes with charging stations minimizes the number of charging stations and ensures safe delivery. Finally, we formulate mixed-integer linear programming to solve the drone delivery route problem. According to simulation results, the proposed JRCS outperforms existing delivery approaches in terms of various performance metrics.

Close to 90% Single-Pass Conversion Efficiency for CO2 Electroreduction in an Acid-Fed Membrane Electrode Assembly

The formation of (bi)carbonates is a pressing issue for CO2 electroreduction in neutral or alkaline solutions. It adversely causes low single-pass conversion efficiency as a result of (bi)carbonate crossover, as well as limited device lifetimes as a result of (bi)carbonate precipitation at the cathode. One emerging solution to circumvent this challenge is conducting the reaction in acids. To this end, we here demonstrate an acid-fed membrane electrode assembly (MEA) for CO2 electroreduction to CO. A diluted electrolyte with an H+ to Cs+ ratio of 1:1 and a relatively low current density are optimal conditions to achieve high CO Faradaic efficiencies. A relatively high H+ versus Cs+ ratio offers high electrocatalytic activities. By systematically evaluating the impact of H+ and Cs+ concentration on the electrochemical performance, we uncover the essential role of the balance between the rates of (bi)carbonate formation and H+ diffusion in determining the selectivity and activity. As a result, we report a CO partial current density of ∼105 mA cm–2 at an ∼4 V cell voltage, a near-doubled activity toward CO compared to a neutral MEA at a similar voltage. Under the optimal conditions for long-term operation, our acid-fed membrane electrode assembly is capable of delivering a CO Faradaic efficiency of ∼80%, an extraordinary single-pass conversion efficiency of ∼90% (about twice that of neutral MEA), and a 50 h long-term stability notably superior to those in previous reports.

Spectral multiplexing of telecom emitters with stable transition frequency.

In a quantum network, coherent emitters can be entangled over large distances using photonic channels. In solid-state devices, the required efficient light-emitter interface can be implemented by confining the light in nanophotonic structures. However, fluctuating charges and magnetic moments at the nearby interface then lead to spectral instability of the emitters. Here, we avoid this limitation when enhancing the photon emission up to 70(12)-fold using a Fabry-Perot resonator with an embedded 19-micrometer-thin crystalline membrane, in which we observe around 100 individual erbium emitters. In long-term measurements, they exhibit an exceptional spectral stability of <0.2 megahertz that is limited by the coupling to surrounding nuclear spins. We further implement spectrally multiplexed coherent control and find an optical coherence time of 0.11(1) milliseconds, approaching the lifetime limit of 0.3 milliseconds for the strongest-coupled emitters. Our results constitute an important step toward frequency-multiplexed quantum-network nodes operating directly at a telecommunication wavelength.

Ce-Loaded HZSM-5 Composite for Catalytic Deoxygenation of Algal Hydrolyzed Oil into Hydrocarbons and Oxygenated Compounds.

Despite the extensive research into the catalytic uses of zeolite-based catalysts, these catalysts have a limited useful lifetime because of the deactivating effect of coke production. This study looks at the use of Cerium (Ce) loaded HZSM-5 zeolite catalysts in the hydrocarbon and oxygenated chemical conversion from Chlorella Vulgaris microalgae crude oil. Characterization of structure, morphology, and crystallinity was performed after the catalysts were manufactured using the impregnation technique. Soxhlet extraction was carried out to extract the crude oil of microalgae. Transesterification reaction was used to produce algal hydrolyzed oil (HO), and the resulting HO was put to use in a batch reactor at 300 °C, 1000 rpm, 7 bars of nitrogen pressure, a catalyst to the algal HO ratio of 15% (wt. %), and a retention time of 6 h. To determine which Ce-loaded HZSM-5 catalysts would be most effective in converting algal HO into non-oxygenated molecules (hydrocarbons), we conducted a series of tests. Liquid product characteristics were analyzed for elemental composition, higher heating value (HHV), atomic ratios of O/C and H/C, and degree of deoxygenation (DOD%). Results were categorized into three groups: product yield, chemical composition, and carbon number distribution. When Cerium was added to HZSM-5 zeolite at varying loading percentages, the zeolite's acid sites became more effective in facilitating the algal HO conversion. The results showed that 10%Ce/HZSM-5 had the greatest conversion of the algal HO, the yield of hydrocarbons, HHV, and DOD% (98.2%, 30%, 34.05 MJ/Kg, and 51.44%, respectively) among all the synthesized catalysts in this research. In conclusion, the physical changes seen in the textural characteristics may be attributed to Cerium-loading on the parent HZSM-5; nevertheless, there is no direct association between the physical features and the hydrocarbons yield (%). The primary impact of Cerium alteration of the parent HZSM-5 zeolite was to change the acidic sites required to boost the conversion (%) of the algal HO in the catalytic deoxygenation process, which in turn increased the hydrocarbons yield (%), which in turn increased the HHV and DOD%.

Indolizin-1-ols with Charged Electron Acceptors: A Direct Way to 3H-Indolizinium-1-olates with Donor Functions.

The reaction of cyclopropenones with pyridines, having an attached integer-charged electron-withdrawing group (pyridinium, imidazolium, and phosphonium) was discovered to afford novel indolizin-1-ol derivatives in high yields with no chromatographic purification required. While being stable as solids, these indolizin-1-ols have a limited lifetime in solution. The study of reasons for such instability uncovered an aerobic oxidative pathway, eventually resulting in indolizine-1,7-dione dimers. The exploration of N-(1-hydroxyindolizin-7-yl)pyridinium salts' chemistry led to a reaction discovery, affording a new type of rare pseudo-cross-conjugated mesomeric betaines (3H-indolizin-4-ium-1-olates with an electron-donating function at C7 position) inaccessible by other means. In this reaction, a sequential introduction of nucleophiles takes place: the first one (Nu1) is represented by simple anilines, whereas Nu2 extends to primary, secondary, aliphatic, aromatic amines, and phenols. For the obtained betaines having unsymmetrical aliphatic amino groups at C7 position an increased order of the C7-Nu2 bond resulting in existence of amide type E/Z-forms (∼1:1 at room temperature) was demonstrated. For aryl amino groups, with typically reduced nitrogen's lone-pair donation, the barrier of rotation around the C7-Nu2 bond was lower, and for the C7-oxy betaines, no such E/Z-isomerism was revealed. Although primary amines (as Nu2) introduce a hydrogen atom in the conjugated betaine system, allowing prototropic tautomerism in this way, non-zwitterionic tautomers (3-amino-7-iminoindolizin-1-ones) were rejected by nuclear Overhauser effect spectroscopy experiments.

High Throughput Studies of Li-La-Zr-O Garnet Solid Electrolytes

Development of next-generation Li-ion batteries has increasingly focused on all-solid batteries employing either ceramic, polymer, or glass electrolytes in order to address shortcomings in currently commercialized liquid electrolyte Li-ion batteries including safety, limited lifetime, and lower energy densities resulting from instability with respect to Li metal anodes.[1] Lithium lanthanum zirconium oxide (LLZO) is a leading candidate for solid Li-batteries due to its high Li-ion conductivity, stability in air and against Li metal, and compatibility with high-voltage cathodes.[2],[3] Despite significant progress being made, our understanding of LLZO is limited by the relatively small number of compositions which have been studied; especially considering the leading contender is a pseudo-quaternary oxide (Ga-doped LLZO) and many studies are now utilizing multiple dopants.[4] Herein, we have applied a high-throughput methodology for synthesizing, characterizing, and testing sets of 64 LLZO electrolytes at the mg-scale. We employ a citrate sol-gel synthesis method whereby reagent solutions are dispensed across a well-plate to give a composition gradient. After drying the samples and burning off the citrates, the resulting powders are pressed into pellets using a custom-made 64-pellet die and the pellets are sintered at the desired temperature. The high-throughput characterization techniques utilized include powder X-ray diffraction, electrochemical impedance spectrometry and electrochemical cycling in order to test electrolyte stability; with each method performed on up to 64 samples simultaneously.Using our methodology, we have studied over 700 samples to produce a full phase stability diagram for the Li-La-Zr-O pseudoternary system. We find that within the Li-La-Zr-O system, there is significant solubility of Li into the La2Zr2O7 pyrochlore structure commonly found as an impurity in LLZO synthesis due to lithium loss. We also find that LLZO appears as both tetragonal and cubic forms throughout the system, with the cubic LLZO appearing in an extremely restricted region that is difficult to access as pure phase due to lithium loss, while excess lithium leads to the tetragonal LLZO. Li conductivity measurements show that both cubic and tetragonal undoped LLZO have similar bulk conductivities, but there is only a limited region near the formal Li7La3Zr2O12 composition where grain boundary conductivity is high. Our methodology is also applied to a comprehensive doping study where over 40 different dopants are evaluated and promising dopants are tested in co-doped compositions. [1] D. Aurbach et al., Electrochimica Acta 2004, 50, 247-254. [2] Q. Liu, et al., J. Power Sources 2018, 389, 120-134. [3] T. Thompson, et al., ACS Energy Letters 2017, 2, 462-468. [4] F. Zheng, et al., J. Power Sources 2018, 389, 198-213.

(Invited) Spin and Optical Properties of the Silicon Vacancy in 4H-SiC for Quantum Science and Technology

Silicon vacancies in SiC are of significant interest for quantum information and sensing due to their unusual combination of long spin coherence time, optical addressability, and room-temperature operation in an industrially-relevant semiconductor. We characterize the spin and optical properties of the V2 silicon vacancy in 4H-SiC for both single defects and ensembles. We also show that they can be deterministically placed with sub-micron precision using focused Li ion implantation. Low-temperature photoluminescence excitation spectroscopy of the spin-dependent optical transitions of single silicon vacancies reveals two sharp lines with linewidths near the radiative lifetime limit. These lines correspond to the ms=±1/2 and ms=±3/2 states of an S=3/2 spin system that can be optically initialized, coherently manipulated with RF pulses, and read out via spin-dependent photoluminescence. We measure the different properties of spins in the two bases, and compare them to theoretical models. To suppress the limiting effects of the nuclear spin bath, we grow isotopically purified SiC with a very low abundance of 29Si and 13C. Our room temperature spin coherence measurements show orders-of-magnitude improvement of the coherence times in these materials. In particular, the inhomogeneous dephasing time T2 * in the ms=±1/2 basis shows a ~100x improvement, reaching 20 μs. We consider the prospects of this system for quantum sensing and as an efficient spin-photon interface for use in quantum networks.This work was supported by the U.S. Office of Naval Research, the OSD Quantum Sciences and Engineering Program, the Defense Threat Reduction Agency, and the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.

Towards a Leadless Wirelessly Controlled Intravenous Cardiac Pacemaker.

Traditional lead-based cardiac pacemakers suffer from lead-related complications including lead fracture, lead dislodgement, and venous obstruction. Modern leadless pacemakers mitigate the complications, but since they are implanted inside the heart with a small battery, their limited battery lifetime necessities device replacement within the patient's lifetime. This paper presents a leadless and batteryless, wirelessly powered intravenous cardiac pacemaker that can potentially mitigate both problems. Wireless power is transferred at 13.56 MHz in bursts between the pacemaker modules to achieve sufficient power over the required distance for wireless pacing. The pacemaker stimulation module is designed to fit within the anatomical constraints of a cardiac vein, consume low power, apply greater than 5 V stimulation and comply with FCC SAR regulations. The module is primarily implemented in CMOS technology to achieve extreme system miniaturization. Ex-vivo pacing capability was demonstrated with a system that can apply 5 V stimulation, consume 1 mW power, and operate up to 2.5 cm TX and RX separation. An in-vivo experiment verified the pacemaker functionality by increasing the heartbeat of Yorkshire pig from 64 bpm to 100 bpm. This work establishes that intravascular cardiac pacing can be achieved that can mitigate lead and battery-related complications. This study has a potential to advance leadless and wirelessly powered pacemaker technology.

Lifetime-Limited and Tunable Quantum Light Emission in h-BN via Electric Field Modulation.

Color-center-based single-photon emitters in hexagonal boron nitride (h-BN) have shown promising photophysical properties as sources for quantum light emission. Despite significant advances toward such a goal, achieving lifetime-limited quantum light emission in h-BN has proven to be challenging, primarily due to various broadening mechanisms, including spectral diffusion. Here, we propose and experimentally demonstrate suppression of spectral diffusion by applying an electrostatic field. We observe both Stark shift tuning of the resonant emission wavelength and emission line width reduction (down to 89 MHz) nearly to the homogeneously broadened lifetime limit. Finally, we find a cubic dependence of the line width with respect to temperature at the homogeneous broadening regime. Our results suggest that field tuning in electrostatically gated heterostructures is promising as an approach to control the emission characteristics of h-BN color centers, removing spectral diffusion and providing the energy tunability necessary for integrate of quantum light emission in nanophotonic architectures.

Eccentric debris belts reveal the dynamical history of the companion exoplanet

ABSTRACT In recent years, a number of eccentric debris belts have been observed in extrasolar systems. The most common explanation for their shape is the presence of a nearby eccentric planetary companion. The gravitational perturbation from such a companion would induce periodic eccentricity variations on the planetesimals in the belt, with a range of precession frequencies. The overall expected shape is an eccentric belt with a finite minimum width. However, several observed eccentric debris discs have been found to exhibit a narrower width than the theoretical expectation. In this paper, we study two mechanisms that can produce this small width: (i) the protoplanetary disc can interact with the planet and/or the planetesimals, slowly driving the eccentricity of the former and damping the eccentricities of the latter; and (ii) the companion planet could have gained its eccentricity stochastically, through planet–planet scatterings. We show that under appropriate conditions, both of these scenarios offer a plausible way to reduce the minimum width of an eccentric belt exterior to a perturbing planet. However, the effects of protoplanetary discs are diminished at large separations (a &amp;gt; 10 au) due to the scarcity of gas and the limited disc lifetime. These findings suggest that one can use the shape and width of debris discs to shed light on the evolution of extrasolar systems, constraining the protoplanetary disc properties and the prevalence of planet–planet scatterings. Further observations of debris-harbouring systems could confirm whether thin debris belts are a common occurrence, or the results of rare initial conditions or evolutionary processes.

Superfast fuel-free tubular hydrophobic micromotors powered by ultrasound

Versatile micro/nanomotors hold remarkable potentials in medical interventions, environmental remediation and cell engineering, etc. However, limited lifetime and weak locomotion prohibit such micromachines away from most practical applications where fast propulsion without chemical fuels is extremely required. Hereby, we introduce a tubular hydrophobic micromotor activated by ultrasonic power to swim at a superfast speed. The proposed tubular micromotor incorporates one hydrophobic layer inside and captures air bubbles as immersed into liquid surroundings. Once applied with the ultrasound at a reasonable frequency, the trapped bubble vibrates to create intensified local streaming, thereby powering the micromotor to swim spontaneously. To achieve high throughput fabrication, template-assisted electrochemical deposition is utilized for constructing the basic multiple-layer tubular configuration of PEDOT-SiO2 micromotors, followed by one step of hydrophobic treatment to modify the inner structure wettability. Tested results illustrate that the micromotor swims at a speed of up to 11 mm/s, which is equivalent to 1100 times of the body length per second. Additionally, motilities in different fluid environments are compared and interesting interactions between micromotor individuals and other neighbored elements are experimentally discussed. Driven by oscillated microbubbles, the fuel-free hydrophobic micromotors exhibit unique potentials to accomplish superfast swimming for myriad biological applications.

Aluminium corrosion in power semiconductor devices

In this study, insulated gate bipolar transistor (IGBT) power modules were exposed to high voltage, high humidity, high temperature and reverse bias (HV-H3TRB) conditions until end-of-life (EoL). The limited lifetime of power semiconductor devices when used in demanding applications involving high relative humidity during operation is commonly reported to be associated with the design of the edge termination in power transistor or diode chips. A physics-of-failure (PoF) oriented methodology was adopted in failure analysis, including using lock-in thermography (LiT) for failure localisation and using an advanced microwave-induced plasma (MIP) decapsulation technique for the selective etching of the edge termination polyimide passivation film. A focused ion beam (FIB) was utilised to create a cross-section of the samples for both scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis. The evidence gathered using the physics-of-failure methodology were compared with the results from advanced statistical analysis of the failure distributions in Weibull plots, including comparison of α and β parameters. This analysis revealed correlation with the Weibull distributions and the results from the physics-of-failure. Aluminium corrosion products were systematically observed on guard rings (GR) and field plates (FP) showing that the migration of these corrosion products forming an electrical path between the guard rings that seems to be a major failure mechanism in high humidity environments when reverse bias voltage is applied.

Water Dynamics in Aqueous Poly-N-Isopropylacrylamide Below and Through the Lower Critical Solution Temperature.

Poly-N-isopropylacrylamide (PNIPAM) is a thermo-responsive polymer that exhibits a reversible structural change from extended chains to aggregates in aqueous solution above its lower critical solution temperature (LCST). Using polarization-selective IR pump-probe spectroscopy, the water orientational dynamics in PNIPAM from below to above the LCST were examined and compared to those of its monomer solution, N-isopropylacrylamide (NIPAM), polyacrylamide, and an acrylamide monomer solution, which are not thermo-responsive. The OD stretch of dilute HOD in H2O is used as a vibrational probe of water orientational dynamics. Below the LCST of the polymer, NIPAM and PNIPAM solutions exhibited identical water dynamics that were significantly different from those of bulk water, containing both faster and slower components due to solute-water interactions. Therefore, there is no difference in the nature of water interactions with a single NIPAM moiety and a long polymer chain. For all systems, including PNIPAM below and above the LCST, the orientational dynamics were modeled with a bulk water component and a polymer/monomer-associated component based on previous experimental and computational findings. Above the LCST, PNIPAM showed fast water orientational relaxation but much slower long-time dynamics compared to those of NIPAM. The slow component in PNIPAM, which was too slow to be accurately measured due to the limited OD vibrational lifetime, is ascribed to water confined in small voids (<2 nm in diameter) of PNIPAM globules. These results highlight important details about thermo-responsive polymers and the dynamics of their solvation water as they undergo a significant structural change.

Wireless charging for cardiac pacemakers based on class‐D power amplifier and a series–parallel spider‐web coil

AbstractBiomedical implants (BMIs) and biomedical sensors (BMSs) help to improve quality of life, detect diseases, provide monitoring of vital signs, and take over the role of malfunctioning organs. These implants and sensors require continuous battery power to work effectively, but the batteries used are restricted by their limited capacity and lifetime. This research reported here involved the design and implementation of a wireless charging system based on a series–parallel spider‐web coil (WPT‐SP‐SWC), specifically for cardiac pacemakers. The experimental design investigated several important parameters, including air gap, applied source voltage, coil size, and operating frequency. Performance metrics were evaluated in terms of output DC voltage, delivered output power, and power transfer efficiency. The target voltage was 5 V, which is adequate to charge a BMI such as a pacemaker, and three source voltages (5, 15, and 25 V) were tested. The design was examined at six operating frequencies, ranging from 1.78 MHz to 6.78 MHz. The most favorable results were achieved at 1.78 MHz. Power transfer efficiencies at a 10 mm air gap were 95.75% and 92.08% for applied voltages of 5 V and 15 V, respectively. The effectiveness of the proposed system was also validated by comparing the findings with previous articles.

A depth-controlled and energy-efficient routing protocol for underwater wireless sensor networks

Underwater wireless sensor network attracted massive attention from researchers. In underwater wireless sensor network, many sensor nodes are distributed at different depths in the sea. Due to its complex nature, updating their location or adding new devices is pretty challenging. Due to the constraints on energy storage of underwater wireless sensor network end devices and the complexity of repairing or recharging the device underwater, this is highly significant to strengthen the energy performance of underwater wireless sensor network. An imbalance in power consumption can cause poor performance and a limited network lifetime. To overcome these issues, we propose a depth controlled with energy-balanced routing protocol, which will be able to adjust the depth of lower energy nodes and be able to swap the lower energy nodes with higher energy nodes to ensure consistent energy utilization. The proposed energy-efficient routing protocol is based on an enhanced genetic algorithm and data fusion technique. In the proposed energy-efficient routing protocol, an existing genetic algorithm is enhanced by adding an encoding strategy, a crossover procedure, and an improved mutation operation that helps determine the nodes. The proposed model also utilized an enhanced back propagation neural network for data fusion operation, which is based on multi-hop system and also operates a highly optimized momentum technique, which helps to choose only optimum energy nodes and avoid duplicate selections that help to improve the overall energy and further reduce the quantity of data transmission. In the proposed energy-efficient routing protocol, an enhanced cluster head node is used to select a strategy that can analyze the remaining energy and directions of each participating node. In the simulation, the proposed model achieves 86.7% packet delivery ratio, 12.6% energy consumption, and 10.5% packet drop ratio over existing depth-based routing and energy-efficient depth-based routing methods for underwater wireless sensor network.

Comparing the economic value of lithium-ion battery technologies in the nine wholesale electricity markets in North America

Lithium-ion batteries are becoming critical flexibility assets in future electric power systems. Batteries can arbitrage price differences in wholesale electricity markets to make a profit while at the same time reducing total system operating costs and improving renewable energy integration. However, lithium-ion batteries have a limited lifetime due to capacity degradation, and one battery pack can only make a limited profit before reaching its end-of-life. In this paper, we screen the profit potential of Lithium iron phosphate (LFP), nickel manganese cobalt (NMC), and lithium nickel cobalt aluminum oxides (NCA) batteries in all nine wholesale electricity markets in North America. We apply a systematic dynamic valuation framework that finds the highest revenue potential for the considered lithium-ion battery project subjecting to its degradation mechanism, while the degradation model used in the valuation is derived based on real lab test data over varying cycle conditions. The study found that battery valuation depends largely on battery technology and storage duration and varies across operational locations. Moreover, the study revealed that calendar life has a greater impact on battery valuation than cycle life for an 8-years calendar life scenario while cycle life shows greater impact for a 15-year calendar life scenario for all battery technologies. This impact is more pronounced in LFP than in NMC and NCA. The study recommends battery operators consider strategies that would maximize a longer cycle life or calendar life usage of a battery as this would accumulate higher profits over its lifetime.

Novel Structure for Electromagnetic Micro-Power Harvester

Energy harvester could supply electronic devices such as implantable biomedical systems. Among the different methods of energy harvesting, the mechanical approach with the electromagnetic transduction method converts mechanical vibrations into output electrical power. In this research, an electromagnetic micro-generator is designed. The proposed device consists of a spring and a planar coil, designed using the Micro-electromechanical Systems (MEMS) technology, and also, a magnet and magnetic core. Different configurations are proposed to optimize the output power of the micro-generator. An innovative structure for the magnetic core is used to maximize the output power. The results show that the output power is increased up to 1.0344 μW and the power density is 2.94 μW/cm3. The attained output power is higher than that reported in the literature. The proposed energy harvester is a suitable replacement for limited lifetime supplies.

A Review on Quality Assurance in Mobile Ad Hoc Network and Applications

Mobile Ad Hoc Network (MANET) routing is highly dynamic network &amp; challenged by power and bandwidth constrained as well as frequent topology changes to which it must adapt to and converge quickly. As we know that it is not possible to give a continuous significant amount of power to mobile devices of MANET so that it could be active for long time. As MANET nodes are powered by batteries with limited lifetime. One of the most existing challenge for MANET is in this Energy constrained to increase the time between recharging. It is possible if and only if energy consumption in communication is less without increasing interruption or packet loss.

Teriparatide and Osteosarcoma Risk: History, Science, Elimination of Boxed Warning, and Other Label Updates

ABSTRACTThe phase 3 trials of the bone anabolic drug teriparatide were prematurely terminated because of a preclinical finding of osteosarcoma in rats treated with high doses of teriparatide for near lifetime. Even so, results from these and subsequent clinical trials showed efficacy and tolerability. Based on the phase 3 results and additional preclinical investigations, Forteo (teriparatide) was approved for use in the United States with an indication for the treatment of osteoporosis in patients at high risk for fracture, a boxed warning regarding potential risk of osteosarcoma, a 2‐year lifetime limitation of use, other risk mitigations, and a requirement to assess for risk of osteosarcoma in humans treated with teriparatide. Subsequent investigations included five real‐world studies directed at assessing a connection between teriparatide and osteosarcoma risk in humans. The early studies did not identify an increased risk of osteosarcoma but were inadequate to sufficiently characterize risk, given the low incidence of this rare form of bone cancer. Learning from these efforts, two studies were undertaken using claims data to identify large cohorts of patients treated with teriparatide and assess whether these patients were found to have osteosarcoma by linking pharmacy claims data with data from cancer registries. These studies showed no increase in osteosarcoma in patients using teriparatide compared with unexposed groups, as well as to the expected population‐based background incidence of the disease. Based on this real‐world evidence and the totality of data collected from postmarketing use and other clinical investigations, the label was updated in 2020. The changes included addition of information from large observational studies using real‐world evidence, removal of the boxed warning, and a revision of the 2‐year lifetime limitation. Thus, observational studies with large sample sizes using real‐world data can provide supportive evidence to facilitate regulatory decisions including the elimination of a boxed warning. © 2022 Eli Lilly and Company. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.