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A dual switched DC-DC converter with high gain for low-voltage fuel cell stack electric vehicles
Abstract A high-gain, boost-derived, non-isolated DC-DC converter employing dual switches is introduced to supply the 400 V DC link bus voltage required for fuel cell vehicles, featuring a minimal number of passive components and diodes. Additional features of a DC-DC converter employed in fuel cell electric vehicles include minimal input current ripple, attenuated inrush currents, lowered voltage stress, and minimized reverse recovery losses, all contributing to a reduction in the converter’s size and weight. The proposed converter achieves the aforementioned characteristics that conventional converters cannot replicate. The voltage gain of this converter, varying from 20 to 8, is achieved with a low wide variation of input voltage between 20 V and 50 V. This article addresses the functionality, control methods, and characteristics of comparable converters. The suggested converter is validated through hardware, providing an output power of 400 W/400 V at a 1 A load across a low-wide fluctuation in input voltage (20 V to 50 V) at a switching frequency of 50 kHz.
World leaders must find the courage to end the fossil-fuel age
Impact of state-of-charge and temperature on the cross-plane thermal conductivity of a Li-ion pouch cell
Molecular dynamics study of host–guest interactions between anticancer drugs and Cucurbit[8]uril nanocontainer
Comprehensive analysis of Escherichia coli in bovine urinary tract infections: serotypes, antibiotic resistance, and virulence gene profiles
Safety and cosmetic results of trans-submental endoscopic thyroidectomy
Impact of mild hyperthermia on tumor-immune dynamics explored through mathematical modeling
Visually estimating body mass of wild pigs
Abstract Body mass of wild pigs ( Sus scrofa ) can provide useful information regarding reproductive capacity of a population, and population health and resilience for this highly-destructive invasive species. Body mass of females is an indicator of whether they reproduce before 1 year of age, which could have substantial impacts on reproductive capacity of a population. Measuring body mass can be difficult because large wild pigs may require > 1 person to weigh, are often located in remote areas making equipment difficult to transport, or are often culled without access to the carcass (e.g., shooting from aircraft). We evaluated our ability to accurately estimate the body mass of wild pigs by visual inspection, and identified which factors (i.e., morphometrics and demographics) influenced the accuracy of our estimates. We visually estimated the body mass of wild pigs and then collected actual weights of 1,210 wild pigs across 5 regions (Alabama, Texas, Hawaii, Guam, Queensland). We also collected morphometric measurements and age to evaluate how these factors impacted our estimates. On average we found our estimates were accurate, averaging only -0.14 kg underestimated weights across all wild pigs weighed. However, our estimates were most severely underestimated (e.g., up to -20 kg) for younger wild pigs (i.e., < 1–3 years) that were heavier (i.e., > 30 kg). We also confirmed that although growth rates slowed after 1 year of age, wild pigs continued to grow in body length, head length, height, and girth as they aged, which explained why the age of an animal influenced our ability to generate accurate estimates. We surmised that young-yet-heavy wild pigs were disproportionally stouter than older animals, thus were underestimated due to their shortened appearance. Underestimating the body mass for young-yet-heavy females could misinform management plans, because these animals may have substantial influence on the reproductive capacity of a population. For visually estimating body mass of wild pigs, we recommend considering indicators of age (e.g., morphological proportions) to avoid underestimating young-yet-heavy animals with stout appearances. We also recommend calibrating observers regularly using known weights and morphometrics.
Participatory evaluation of an irrigation decision support system for water-saving and productivity gains in Lake Urmia Basin
Factors affecting health-related quality of life in women with and without abnormal uterine bleeding: an unmatched case-control study
Chile must preserve international science in Antarctica
Cymbopogon citratus and Lippia multiflora essential oils as alternative repellent to DEET against Anopheles gambiae s.l. in Bobo-Dioulasso, Burkina Faso
Brain power comparison between microgravity and head-down tilt bed rest: an electroencephalography approach
Abstract This study examines neurophysiological changes in microgravity by comparing EEG data from two ground analog 60-day head-down tilt bed rest (HDBR) experiments (ESA/DLR “Cocktail” and “RSL”) and the NEUROSPAT experiment in space. The primary objective was to determine whether HDBR could effectively model spaceflight’s impact on the human brain’s EEG signal. In the HDBR dataset, increases in relative delta (2–4 Hz) ( p < 0.01) and theta (4–8 Hz) ( p < 0.001) power bands were observed during a two-month HDBR experiment, predominantly in the left temporal and parieto-occipital regions. Conversely, the NEUROSPAT dataset showed a significant increase in beta (12–30 Hz) ( p < 0.05) power in the left somatosensory cortex during in-flight conditions, suggesting a potential adaptation to disrupted proprioceptive input and motor control in microgravity. The contrasting findings between the two datasets indicate that while HDBR can simulate some aspects of microgravity, it may not serve as a model for all central nervous system changes, especially those related to proprioception and motor functions. This highlights the need for further research, including larger sample sizes, consistent EEG recording conditions, and integration of additional physiological and cognitive markers to fully understand the effects of prolonged microgravity.