maximum exposure
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2022 ◽  
Vol 9 ◽  
Author(s):  
Bo Xu ◽  
David Anguiano Sanjurjo ◽  
Davide Colombi ◽  
Christer Törnevik

International radio frequency (RF) electromagnetic field (EMF) exposure assessment standards and regulatory bodies have developed methods and specified requirements to assess the actual maximum RF EMF exposure from radio base stations enabling massive multiple-input multiple-output (MIMO) and beamforming. Such techniques are based on the applications of power reduction factors (PRFs), which lead to more realistic, albeit conservative, exposure assessments. In this study, the actual maximum EMF exposure and the corresponding PRFs are computed for a millimeter-wave radio base station array antenna. The computed incident power densities based on near-field and far-field approaches are derived using a Monte Carlo analysis. The results show that the actual maximum exposure is well below the theoretical maximum, and the PRFs similar to those applicable for massive MIMO radio base stations operating below 6 GHz are also applicable for millimeter-wave frequencies. Despite the very low power levels that currently characterize millimeter-wave radio base stations, using the far-field approach can also guarantee the conservativeness of the PRFs used to assess the actual maximum exposure close to the antenna.


Author(s):  
Pankaj Mehta ◽  
Jennifer Ngangbam ◽  
Neelam Thakur ◽  
Navneet Kaur

The explosive global change in the emissions of Sulphur dioxide (SO2) over the decades have brought about tremendous effects in the regional as well as global scale in the composition and quality of air that we breathe. The global SO2 emission peaked in the 1970s, decreased until 2000 and has risen to peak again mainly as the result of increased globalization in developing countries. The global estimation is surprisingly low but the regional output of SO2 is high. The main hotspots being in East Asia Countries. The Sulphur aerosols not only impacts the animals’ health, but those of the ecosystems at large. SO2 contributes to global warming, ozone depletion, acid rain, smog etc. that has brought disastrous environmental conditions. WHO recommends a maximum exposure of not more than 0.5 ppm for around 24 hours’ span. SO2 reacts with other gases to form sulphate particles, constituent of particulate matters i.e. PM 2.5 concentrations, the exposure to which causes skin, respiratory, reproductive failures and cardiovascular ailments. This study, as such, is meant to bring into light the sources of SO2 and its harmful effects on health and environment at large. Air pollution is a major issue with adverse effects prevailing over the globe at present.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6325
Author(s):  
Yaohua Gong ◽  
Tao Huang ◽  
Xun’an Zhang ◽  
Purong Jia ◽  
Yongyong Suo ◽  
...  

Determination of the fracture angle and maximum exposure value of extended Puck’s 3D inter-fiber failure (IFF) criterion is of great importance for predicting the failure mechanism of unidirectional fiber-reinforced composites. In this paper, a reliable semi-analytical algorithm (RSAA) is presented for searching fracture angle and corresponding exposure value for the extended Puck’s failure criterion. One hundred million cases are tested for verifying the accuracy of the present and other algorithms on Python using the strength-value-stress-state combinations more universal than those in previous literatures. The reliability of previous algorithms is discussed and counterexamples are provided for illustration. The statistical results show RSAA is adequate for implementation in extended Puck’s criterion and much more reliable than previous algorithms. RSAA can correctly predict the results with a probability of over 99.999%.


JTCVS Open ◽  
2021 ◽  
Author(s):  
Connor P. McDonald ◽  
Dawn S. Hui
Keyword(s):  

2021 ◽  
Author(s):  
Bo Xu ◽  
Davide Colombi ◽  
Christer Törnevik ◽  
Fatemeh Ghasemifard ◽  
Jiajia Chen

The traditional approach of radio frequency electromagnetic field exposure compliance assessment is highly conservative when applied to radio base station antennas implementing dynamic beamforming. In this paper, an analytical model based on the queuing theory with a hyper-exponential service distribution time is developed to assess the time-averaged actual maximum downlink exposure of 5G multi-column radio base station antennas by taking into account the effects of beam scanning over time in free space. Using the measured antenna radiation patterns, the 5G downlink antenna precoding codebook, and assuming a conservative user equipment distribution, the ratio of the actual maximum exposure to the theoretical maximum exposure with 100% traffic load and 75% time-division duplex downlink duty cycle is found to be less than 0.5 and 0.3 for four-transmitter and eight-transmitter radio base station antennas, respectively. These results show that assuming constant peak power transmission in a fixed direction leads to an overestimate of downlink exposure also from conventional antennas characterized by only a few transmitters in addition to massive multi-input multi-output products.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 522
Author(s):  
Xinying Yang ◽  
Jin Tian ◽  
Yang Guo ◽  
Mengyuan Teng ◽  
Haixia Liu ◽  
...  

Zinc oxide (ZnO) possesses superior chemical and physical properties so that it can occupy an essential position in the application of nanostructures. In this paper, ZnO nano-rod arrays were synthesized by a simple one-step hydrothermal approach with the assistance of cetyl trimethyl ammonium bromide (CTAB). Exposure of the {0001} facets could be controlled by adjusting the amount of CTAB and the maximum exposure of the {0001} facets of ZnO nanorods is obtained at 1.2 g of CTAB. The photocurrent, EIS, and PL measurements support the facile charge transfer with minimum recombination of the photogenerated excitons of the ZnO nano-rod arrays obtained at 1.2 g of CTAB. Consequently, the obtained ZnO nano-rod arrays at the optimal CTAB of 1.2 g exhibit an excellent photocatalytic degradation rate of 99.7% for rhodamine B (RhB), while the degradation rate of RhB by the ZnO obtained without CTAB is only 35%.


2021 ◽  
pp. 109-126
Author(s):  
Gillian Kelly

This chapter looks at Power’s work within the genre of musicals. Despite his lack of singing and dancing ability, he was cast as the lead in five musicals between 1937 and 1939, although he made no more films in this genre after the decade ended. To compensate for his lack of musical talent, Power was cast opposite female stars who were skilled musical performers, being paired with ice-skating champion Sonja Henie twice and singer-actress Alice Faye three times. This move by Twentieth Century-Fox demonstrates the actor’s appeal to contemporary audiences at a time when musicals were extremely popular and its plans for his maximum exposure. Power’s characterisations in all five musicals are slightly different, some building on his already established screen image and others advancing it either slightly or significantly. Indeed, while his films with Henie have many similarities to his comedic pairings with Young, Faye provides his most sensual screen pairing to date, suggesting a new sexual maturity to his image at the end of the 1930s.


Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 20
Author(s):  
Eric Tielemans ◽  
Heidi Erasmus ◽  
Mandie Momberg ◽  
Anthony Pfefferkorn ◽  
Norba Targa ◽  
...  

NexGard® Combo, a novel topical endectoparasiticide product for cats, is a combination of esafoxolaner, eprinomectin and praziquantel. The safety of this novel combination administered to females during reproduction and lactation was evaluated per analysis of breeding parameters and adverse reactions observed on females and offspring. Females with successful breeding history were randomized to three groups, a placebo group and groups treated with the novel formulation at 1× or 3× multiples of the maximum exposure dose. Females were dosed at 28-day intervals, at least twice before mating, then during a period including mating, pregnancy, whelping and 56 days of lactation. In the placebo, 1× and 3× groups, 10, 9 and 10 females, respectively completed the study (nine, seven and nine females achieved pregnancy), and were dosed 7.1 times on average. Breeding parameters included success of mating, success of gestation, length of gestation, abortion rate, number of live, dead and stillborn kittens at birth, number of kittens with abnormalities, weight of kittens after birth and at weaning, growth of kittens, proportion of male and female kittens, and proportion of kittens born alive and weaned. No significant adverse reactions related to the novel combination were observed on females and on kittens; no significant and adverse effects on breeding parameters were observed.


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