We use Direct Numerical Simulation (DNS) through a Volume of Fluid (VOF) solver with Adaptive Mesh Refinement (AMR) to analyze the atomization of a pulsating round liquid jet with a narrow length scale range configuration , using three grid sizes based on the characteristic scales of the deformation mechanism. We compute drop properties statistics and general spray features for each case. We find that

Accurate geolocation of mobile equipment operating in outdoor environments is an increasingly important question in robotics and automation. Modern geolocation systems, however, rely on the crucial ability for a mobile device to receive specific radio signals at all times. As such geolocation systems are increasingly deployed in harsh or difficult environments, for example, in the presence of tall

Autonomous exploration of subterranean environments remains a major challenge for robotic systems. In response, this paper contributes a novel graph‐based subterranean exploration path planning method that is attuned to key topological properties of subterranean settings, such as large‐scale tunnel‐like networks and complex multibranched topologies. Designed both for aerial and legged robots, the proposed

In this paper, we discuss the following inverse problem: how to reconstruct the mass distribution function of a two-span beam with an overhang via its polynomial fundamental mode and polynomial stiffness function. This leads to a basic equations group constituted by the coefficients of the mass distribution and the stiffness distribution function. To make the basic equations group match, one way is

Due to its inherent low damping, a power transmission line is prone to wind induced vibration. Vibration control is needed to suppress the aeolian vibration of the transmission-line to reduce the fatigue and to extend its service life. Though patented in 1928, more than 90 years ago, the Stockbridge damper or its variants are still commonly used for vibration suppression of conductors in modern day

The basic absorption thermal energy storage cycle suffers from low energy storage efficiency and density, while the conventional H2O/salt working fluids risk crystallization problems. To achieve crystallization-free thermal batteries with improved energy storage performance, a hybrid compression-assisted absorption thermal energy storage cycle using H2O/1,3-dimethylimidazolium dimethylphosphate is

This work aims to analysis and detects the reasons of the collapse of a road in northern Morocco using simulation based on the Finite-Difference Time-Domain method (FDTD) and a real survey by ground-penetrating radar (GPR) method. In the simulation, we test several targets buried in dry soil at the same depth. Depending on the simulation results GPR survey is done in two zones. The first zone shows

The selection of the most suitable instrument for measuring the flow of sewage is especially important due to the urgent work of sewage treatment and complex measurement environment of sewage systems. To this end, the current work reviews a number of sewage flow measuring instruments divided into four categories of differential pressure flowmeters, open channel flowmeters, electromagnetic flowmeters

To reveal the effects of rainfall and runoff-yield conditions on runoff, the abrupt change of the correlation between rainfall and runoff is discussed. Then, according to the correlation between rainfall and runoff with the different rainfall states, the multivariate dynamic regression models of rainfall and runoff are constructed, and the effects of rainfall and runoff-yield conditions on runoff are

Nowadays, design, development, and motion planning of a mobile robot explore research areas in the field of robotics. Mobile robots have an extensive area of applications in various fields like space exploration, military application, industrial use, and many more. Hence, the design and development of a mobile robot is a crucial part of the above application. Among all the mobile robot, the quadrupedal

Absolute gravimeters are instruments that realize reference measurements of the free-fall acceleration, at present by tracking the freely falling objects using interferometry. The functional model of measurements of absolute gravimeters contains parameters related to the model of the local gravity field as well as to the model of particular instrumental effects. In this paper, we show an improvement

Gas-sensor drift is an important issue fading the gas identification performance of an Electronic Nose (E-nose). The most popular drift countermeasure is mathematical-model updating by periodic drift calibrations. Accordingly, drift-calibration-sample formation becomes a challenging issue in online detection because of rare opportunity for collecting drift-calibration samples. However, the class-imbalance

Due to the harsh circumstances, planetary gearboxes as the important transmission component of mechanical equipment inevitably incur unexpected failures. Due to the merits of encoder signal, the research of encoder signal for fault detection have recently received much attention. However, the research on how to apply encoder signal to the fault detection of planetary gearbox under variation speed conditions

Three phase medium frequency direct current (DC) resistance spot welding (RSW) machine has a complex electrical structure. Because the structure included various electrical components, it is hard to establish an accurate and integrated numerical model to simulate the energy delivery and control process. This study employed a particle swarm optimization (PSO) algorithm to conduct an intelligent parameters

Magnetic scanning devices for structures, components, and materials have been the subject of intense scientific research and are potential prototypes for use in industry, especially in non-destructive inspection, to identify defects in metal structures subject to extreme conditions such as high temperatures, pressure, and strong tension. These conditions can lead to the failure of these structures

In the robot field, it has always been a hard issue of solving inverse kinematics (IK) problems of redundant robot. Although many researchers have come up with solutions for redundant robots with different configurations, there is still an issue of computational efficiency for redundant robot with complex configuration. In this paper, we proposed a novel optimization method which solves redundant robot

The multicriteria group decision-making method in fuzzy environment has become the focus of many scholars. The purpose of this paper is to extend the traditional ORESTE (organísation, rangement et Synthèse de données relarionnelles) method to solve the multi-criteria group decision-making problem under IT2FS environment. The main contributions of this paper are to define a new similarity measure and

Fault diagnosis of rotating machinery is essential for maintaining system performance and ensuring the operation safety. Deep learning (DL) has been recently developed rapidly and achieved remarkable results in fault diagnosis. However, the temporal information from time-series signals is ignored by convolutional neural networks (CNNs) based methods. Besides, the robustness against the noise is essential

The responses of Al/PTFE reactive materials (RMs) under shock compression were investigated by a single-stage gas gun. A 3D mesoscale-model was established based on micro-computed tomography (micro-CT) slice images and confirmed with experimental results. In the high-pressure stage, the composites reacted partially, whereas there were no deviations between the partially reacted Hugoniot and the inert

Recent studies have reported protective efficacy of both natural immunity1 and vaccine-induced immunity2–7 against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenge in rhesus macaques. However, the importance of humoral and cellular immunity for protection against SARS-CoV-2 infection remains to be determined. Here we show that adoptive transfer of purified IgG from convalescent

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Water locked away in Martian sediments could be split into the gases needed by humans and their machines.

Nature speaks to old hands and first timers about the work they did to make their reviews sing.

Sugars ‘write’ a signal that helps embryonic cells to transition to a vital new job.

Self-assembling particles exhibit a mind-boggling array of structure and composition.

A sustainable ocean economy, video of the moment the Arecibo telescope collapsed and scientists have restored vision in old mice by reversing their biological clocks.

Photon-based quantum computer does a calculation that ordinary computers might never be able to do.

In Earth science, information science, space science, and other disciplines, scientists use the land surface parameter inversion method in their work, applying this to the atmosphere, vegetation, soil, drought, and so on. Multidisciplinary experts sometimes collaborate on a particular application. However, these remote sensing models do not have a unified method of description and management and cannot

The examination of vaginal secretions epithelial is of great importance to female reproductive health. The results of manual detection will be affected by subjective judgment and fatigue. In this paper, an identification method based on computer vision is proposed to identify vaginal secretions epithelial cells and some bacteria. The experimental results demonstrate that the method can significantly

Purpose This research empirically builds a manufacturing firm's power construct that can be used to assess the changes suppliers are willing to make in their operations decision areas, such as quality systems, product management, process management, material management systems and information systems. This approach has not been empirically explored in the operations and supply chain management literature

Millions of craniofacial surgeries are performed annually worldwide for craniofacial bones’ replacement and augmentation. This represents a significant economic burden as well as aesthetic expectations. Autografts and allografts are the first choice for treatment of craniofacial defects; however, their limited availability and difficulty to shape have led to investigation for alternative strategies

When geneticist Haig H. Kazazian Jr. was 16, he overheard a conversation between his father and a family friend. “What do you think? Is he going to be a doctor?” asked his father. “I think he’ll be a scientist,” replied the friend. Kazazian went on to become both. Trained in pediatrics, he developed a love of genetics early on and took up research. At first, he focused on blood disorders, with an eye

We use the synthetic control method to analyze the effect of face masks on the spread of COVID-19 in Germany. Our identification approach exploits regional variation in the point in time when wearing of face masks became mandatory in public transport and shops. Depending on the region we consider, we find that face masks reduced the number of newly registered severe acute respiratory syndrome coronavirus

High-affinity iron (Fe) scavenging compounds, or siderophores, are widely employed by soil bacteria to survive scarcity in bioavailable Fe. Siderophore biosynthesis relies on cellular carbon metabolism, despite reported decrease in both carbon uptake and Fe-containing metabolic proteins in Fe-deficient cells. Given this paradox, the metabolic network required to sustain the Fe-scavenging strategy is

In photosynthetic eukaryotes, thousands of proteins are translated in the cytosol and imported into the chloroplast through the concerted action of two translocons—termed TOC and TIC—located in the outer and inner membranes of the chloroplast envelope, respectively. The degree to which the molecular composition of the TOC and TIC complexes is conserved over phylogenetic distances has remained controversial

Fluorescent molecules are like antennas: The rate at which they absorb light depends on their orientation with respect to the incoming light wave, and the apparent intensity of their emission depends on their orientation with respect to the observer. However, the directions along which the most important fluorescent molecules in biology, fluorescent proteins (FPs), absorb and emit light are generally

α-Synuclein is expressed at high levels at presynaptic terminals, but defining its role in the regulation of neurotransmission under physiologically relevant conditions has proven elusive. We report that, in vivo, α-synuclein is responsible for the facilitation of dopamine release triggered by action potential bursts separated by short intervals (seconds) and a depression of release with longer intervals

Obligate symbioses involving intracellular bacteria have transformed eukaryotic life, from providing aerobic respiration and photosynthesis to enabling colonization of previously inaccessible niches, such as feeding on xylem and phloem, and surviving in deep-sea hydrothermal vents. A major challenge in the study of obligate symbioses is to understand how they arise. Because the best studied obligate

Plant tropism refers to the directed movement of an organ or organism in response to external stimuli. Typically, these stimuli induce hormone transport that triggers cell growth or deformation. In turn, these local cellular changes create mechanical forces on the plant tissue that are balanced by an overall deformation of the organ, hence changing its orientation with respect to the stimuli. This

In the wake of the COVID-19 pandemic many countries implemented containment measures to reduce disease transmission. Studies using digital data sources show that the mobility of individuals was effectively reduced in multiple countries. However, it remains unclear whether these reductions caused deeper structural changes in mobility networks and how such changes may affect dynamic processes on the

What are the ground states of an interacting, low-density electron system? In the absence of disorder, it has long been expected that as the electron density is lowered, the exchange energy gained by aligning the electron spins should exceed the enhancement in the kinetic (Fermi) energy, leading to a (Bloch) ferromagnetic transition. At even lower densities, another transition to a (Wigner) solid,

Understanding the processes underlying normal, impaired, and recovered language performance has been a long-standing goal for cognitive and clinical neuroscience. Many verbally described hypotheses about language lateralization and recovery have been generated. However, they have not been considered within a single, unified, and implemented computational framework, and the literatures on healthy participants

Myasthenia gravis (MG) is a disorder of the neuromuscular junction mediated by the actions of autoantibodies directed against one of several proteins expressed on the postjunction muscle membrane. For the large majority of MG patients the target for the autoantibodies is the acetylcholine receptor (AChR) (1) that interacts with acetylcholine, the transmitter released by the motor nerve, to trigger

In science news around the world, the assassination of a prominent Iranian scientist may impede diplomatic efforts to revive the 2015 Iran nuclear deal. The Nature Research group announced its foray into open-access scientific publishing, charging authors a steep fee to make their papers free to read. The U.S. Army Corps of Engineers denied a permit to the Pebble Mine, potentially dealing a death blow

Artificial intelligence (AI) has solved one of biology's grand challenges: predicting how proteins curl up from a linear chain of amino acids into 3D shapes that allow them to carry out life's tasks. This week, leading structural biologists and organizers of a biennial protein-folding competition announced the achievement by researchers at DeepMind, a U.K.-based AI company. They say the DeepMind method

For decades, something in urban streams has been killing coho salmon in the U.S. Pacific Northwest. Up to 90% of the adults migrating up certain streams to spawn suddenly die after rainstorms. Researchers report online in Science that the primary culprit comes from a chemical widely used to protect tires from ozone, a reactive atmospheric gas. The toxicant, called 6PPD-quinone, leaches out of the small

Brexit is set to become a reality, but its likely consequences for researchers are still emerging. The United Kingdom left the European Union on 31 January, but has remained part of EU trade and travel agreements while the final Brexit deal is negotiated. On 1 January 2021, those ties will be severed—and the future of research funding, international collaboration, and wrinkle-free supply chains of

When Rudyard Kipling told how the leopard got his spots, he missed the mark. Leopards have "rosettes"; spots are for cheetahs. But whatever you call the markings, how these wild cats—and their domestic counterparts—acquire them has long been a mystery. Now, researchers have found an answer by studying domestic cats. In doing so they have shown that a 70-year-old theory explaining color patterns in

Chimpanzee sanctuaries are under the microscope. Since April, former employees of some of the country's biggest chimp refuges have alleged a number of animal welfare issues, from apes not getting proper medical care to hair pulling and other stress behaviors. All of this could be bad news for these operations, as they struggle for donations, and for the retirement of ex–research chimps that still remain

Ordinary sound is a harmonic oscillation in the density, temperature, and velocity of air. Sound intensity decreases because of the spreading of the sound wave, but ultimately, sound attenuation is due to the diffusion of momentum and energy from the crest to the trough of the wave. This effect can be characterized in terms of the diffusivity D of sound. In air, there is a very large separation of

For centuries, humans have been fascinated by flight. Leonardo da Vinci (1452–1519) meshed his skills as an artist, biologist, and engineer to sketch designs for flying machines modeled after bird and bat anatomy. Today, multidisciplinary scientists work systematically from investigating biological prototypes to conducting flight performance tests on new bionic robots. On page 1214 of this issue, Phan

Two-dimensional (2D) semiconductors, such as transition-metal dichalcogenides, may enable new optoelectronic technologies (1). The optical excitation in these atomically thin materials creates tightly bound excitons composed of an excited electron and a valence-state hole (2), as well as a plethora of exciton complexes due to the reduced screening in Coulomb attraction (3–5). So far, excitons with

We are used to human behavior, and the actions of other animals, being described as selfish, aggressive, or cooperative. Such words come up less often when contemplating plants. Yet plants too have evolved a fascinating array of behavioral strategies in their struggle for resources, although these are hard to demonstrate and quantify. Whether and when it pays for plants to selfishly overproduce roots

More than 70 years ago, electrical stimulation of the human visual cortex was shown to elicit the perception of a brief flash of light, or phosphene (1). Subsequently, there were numerous attempts to develop cortical visual prostheses (CVPs) that electrically stimulate the visual cortex to restore vision to people with acquired blindness (2–4). The basic design of a CVP is simple: A head-mounted camera

Decarbonizing the electricity sector is critical for addressing climate change, particularly given the expected role of an expanded clean electricity system for home heating, transportation, and industry (1). This will require vast investment in new infrastructure such as renewable-energy power plants and batteries. Absent major investment in carbon-capture equipment or fuel switching, it will also