We present a discrete-time, one-dimensional quantum walk based on the entanglement between the momentum of ultracold rubidium atoms (the walk space) and two internal atomic states (the "coin" degree ...of freedom). Our scheme is highly flexible and can provide a platform for a wide range of applications such as quantum search algorithms, the observation of topological phases, and the realization of walks with higher dimensionality. Along with the investigation of the quantum-to-classical transition, we demonstrate the distinctive features of a quantum walk and contrast them to those of its classical counterpart. Also, by manipulating either the walk or coin operator, we show how the walk dynamics can be steered or even reversed.
Declining oxygen in the global ocean and coastal waters Breitburg, Denise; Levin, Lisa A; Oschlies, Andreas ...
Science (American Association for the Advancement of Science),
01/2018, Letnik:
359, Številka:
6371
Journal Article, Web Resource
Recenzirano
Odprti dostop
Oxygen is fundamental to life. Not only is it essential for the survival of individual animals, but it regulates global cycles of major nutrients and carbon. The oxygen content of the open ocean and ...coastal waters has been declining for at least the past half-century, largely because of human activities that have increased global temperatures and nutrients discharged to coastal waters. These changes have accelerated consumption of oxygen by microbial respiration, reduced solubility of oxygen in water, and reduced the rate of oxygen resupply from the atmosphere to the ocean interior, with a wide range of biological and ecological consequences. Further research is needed to understand and predict long-term, global- and regional-scale oxygen changes and their effects on marine and estuarine fisheries and ecosystems.
We report the properties of a hydrogen (H2) gas sensor based on platinum (Pt)-coated carbon nanotubes (CNTs) in this paper. To fabricate the Pt–CNT composite sensor, a highly aligned CNT sheet was ...prepared on a glass substrate from a spin-capable CNT forest, followed by electrobeam (e-beam) deposition of Pt layers onto the CNT sheet. To investigate the effect of Pt on the response of the sensor, Pt layers of different thicknesses were deposited on the CNT sheets. A Pt thickness of 6 nm yielded the highest response for H2 detection, whereas Pt layers thinner or thicker than 6 nm led to a reduction of the surface area for gas adsorption and, consequently, decreased response. The Pt–CNT composite sensor detects H2 concentrations of 3–33% at room temperature and shows reproducible behavior with fast response and recovery times.
This paper presents a novel bioinspired algorithm to tackle complex optimization problems: the coral reefs optimization (CRO) algorithm. The CRO algorithm artificially simulates a coral reef, where ...different corals (namely, solutions to the optimization problem considered) grow and reproduce in coral colonies, fighting by choking out other corals for space in the reef. This fight for space, along with the specific characteristics of the corals' reproduction, produces a robust metaheuristic algorithm shown to be powerful for solving hard optimization problems. In this research the CRO algorithm is tested in several continuous and discrete benchmark problems, as well as in practical application scenarios (i.e., optimum mobile network deployment and off-shore wind farm design). The obtained results confirm the excellent performance of the proposed algorithm and open line of research for further application of the algorithm to real-world problems.
Inspired by the high specific capacitances found using ultrathin films or nanoparticles of manganese oxides (MnOx), we have electrodeposited MnOx nanoparticles onto sheets of carbon nanotubes (CNT ...sheets). The resulting composites have high specific capacitances (Csp <= 1250 F/g), high charge/discharge rate capabilities, and excellent cyclic stability. Both the Csp and rate capabilities are controlled by the average size of the MnOx nanoparticles on the CNTs. They are independent of the number of layers of CNT sheets used to form an electrode. The high-performance composites result from a synergistic combination of large surface area and good electron-transport capabilities of the MnOx nanoparticles with the good conductivity of the CNT sheets. Such composites can be used as electrodes for lithium batteries and supercapacitors.
•The Co3O4 particles were directly deposited on CNT sheet by the electrodeposition method.•Sensitivity of the sensor highly depends on the mean size of the Co3O4 particles.•The mean size of the Co3O4 ...particles was controlled by the electro-deposition time.•Annealing treatment could improve the performance of the sensor at room temperature.
Hydrogen gas (H2) sensors are fabricated using a carbon-nanotube (CNT) sheet decorated with cobalt oxide (Co3O4) nanoparticles. The proposed hybrid sensor is fabricated by electrodepositing Co3O4 on CNT sheets. With an annealing treatment, the CNTs/Co3O4 composite sensors exhibit a much higher response to H2 gas at room temperature than sensors that have not undergone the annealing treatment. The functional groups and oxygen defects that are formed during annealing serve as chemisorption sites for H2 at room temperature. Moreover, the annealing treatment results in strong interaction between Co3O4 and the CNTs, which allows carriers to easily diffuse from the Co3O4 nanoparticles to the CNTs.
The aim was to compare the epidemiology of injuries between elite male and female football players from the same club. Injuries and individual exposure time in a male team and a female team, both ...playing in the Spanish first division, were prospectively recorded by the club's medical staff for five seasons (2010‐2015) following the FIFA consensus statement. Total, training, and match exposure hours per player‐season were 20% higher for men compared to women (P<.01). Total, training, and match injury incidence were 30%‐40% higher in men (P≤.04) mainly due to a 4.82 (95% confidence interval CI 2.30‐10.08) times higher incidence of contusions, as there were no differences in the incidence of muscle and joint/ligament injuries (P≥.44). The total number of absence days was 21% larger in women owing to a 5.36 (95% CI 1.11‐25.79) times higher incidence of severe knee and ankle ligament injuries. Hamstring strains and pubalgia cases were 1.93 (95% CI 1.16‐3.20) and 11.10 (95% CI 1.48‐83.44) times more frequent in men, respectively; whereas quadriceps strains, anterior cruciate ligament ruptures, and ankle syndesmosis injuries were 2.25 (95% CI 1.22‐4.17), 4.59 (95% CI 0.93‐22.76), and 5.36 (95% CI 1.11‐25.79) times more common in women, respectively. In conclusion, prevention strategies should be tailored to the needs of male and female football players, with men more predisposed to hamstring strains and hip/groin injuries, and women to quadriceps strains and severe knee and ankle ligament injuries.
Genetic association studies on alopecia areata (AA) performed in various populations have shown heterogeneous results. The aim of the current review was to synthesize the results of said studies to ...estimate the impact of FAS, FASL, PTPN22, CTLA4 and IL2RA gene polymorphisms on AA susceptibility.
A systematic literature search was conducted in the Medline, Web of Science, Scopus, EMBASE and LILACS databases. Studies published up to June 2020 were included. The results available in the grey literature including the Open Grey and Google Scholar databases were also used. The texts of potentially related studies were screened by individual reviewers. Evidence of publication bias was assessed using the Newcastle-Ottawa scale and the quality of evidence was assessed using the GRADE system. The quantitative synthesis was performed using the fixed effect model.
Out of 1784 articles, we identified 18 relevant articles for the qualitative synthesis and 16 for the quantitative synthesis. In a study of rs2476601 polymorphism of PTPN22 gene, including 1292 cases and 1832 controls, a correlation was found with the risk of developing AA in the allelic model (OR1.49 95% C:1.13-1.95), the heterozygous codominant (OR1.44 95% CI:1:19-1.76) and dominant model (OR1.43 95% CI:1.18-1.73). No association was found between the presence of FASL, PTPN22, CTLA and IL2RA gene polymorphisms with AA susceptibility.
The results suggest that the T allele of the single nucleoid polymorphism (SNP) rs2476601 in PTPN22 gene is a risk factor for developing alopecia areata. However, more robust studies defining the ethnic background of the population of origin are required, so that the risk identified in the present study can be validated. Additionally, a greater number of studies is necessary to evaluate the role of the FAS, FASL, PTPN22, CTLA4 and IL2RA genetic variants, given the heterogenous results found in the literature.
•The sensor can be fabricated easily using a spin-capable CNT.•Metal oxides were deposited on CNT yarn to improve performance of the sensor.•Flexibility of the sensor can be achieved by using CNT as ...sensor platform.
In this study, carbon nanotube (CNT)-yarn humidity sensors were fabricated using either a MnO2-coated CNT yarn or a pure CNT yarn as the sensing material. The results of this study showed that an increase in humidity causes a decrease in the hole density of p-type nanotubes, which in turn results in an increase in the resistance of the sensors. Here, the MnO2-coated sensor showed better sensitivity than the uncoated sensor. Active MnO2 coated on a CNT yarn serves as a catalyst for promoting charge transfer between the H2O molecules and the CNTs by forming a p–n heterojunction; this charge transfer plays an important role in realizing a composite sensor with high sensitivity. Further, these CNT-yarn sensors are flexible, bendable, and durable. These sensors can also be used as gas and vapor sensors, as well as for the construction of flexible sensing materials.