92 research outputs found
The Electromagnetic Force between Two Parallel Current Conductors Explained Using Coulombâs Law
In this book chapter the electromagnetic force between two parallel electric conductors has been derived, applying thereby the effects of propagation delay and the Special Relativity theory, taking thereby also into count the thus far neglected effects introduced by the voltage sources of both circuits. This has been done for a specific case consisting of two rectangular circuits, aligned to each other along one of the long sides, at a distance that is short compared to the long sides. The intention in doing so is to make a meaningful application of the concept of âtwo parallel conductors of infinite lengthâ, so that it is possible to make a complete calculation of the force between the two circuits, avoiding thus making a vague claim as for example Maxwell, saying that the other parts of the conductors do not contribute to the force. What is radically new in this interpretation is that it is Coulombâs law that is responsible for the force
The sensitivity of tropospheric chemistry to cloud interactions
Clouds, although only occupying a relatively small fraction of the troposphere volume, can have a substantial impact on the chemistry of the troposphere. In newly formed clouds, or in clouds with air rapidly flowing through, the chemistry is expected to be far more active than in aged clouds with stagnant air. Thus, frequent cycling of air through shortlived clouds, i.e. cumulus clouds, is likely to be a much more efficient media for altering the composition of the atmosphere than an extensive cloud cover i.e. frontal cloud systems. The impact of clouds is tested out in a 2-D channel model encircling the globe in a latitudinal belt from 30 to 60 deg N. The model contains a detailed gas phase chemistry. In addition physiochemical interactions between the gas and aqueous phases are included. For species as H2O2, CH2O, O3, and SO2, Henry's law equilibria are assumed, whereas HNO3 and H2SO4 are regarded as completed dissolved in the aqueous phase. Absorption of HO2 and OH is assumed to be mass-transport limited. The chemistry of the aqueous phase is characterized by rapid cycling of odd hydrogen, (H2O2, HO2, and OH). O2(-) (produced through dissociation of HO2) reacting with dissolved O3 is a major source of OH in the aqueous phase. This reaction can be a significant sink for O3 in the troposphere. In the interstitial cloud air, odd hydrogen is depleted, whereas NO(x) remains in the gas phase, thus reducing ozone production due to the reaction between NO and HO2. Our calculations give markedly lower ozone levels when cloud interactions are included. This may in part explain the overpredictions of ozone levels often experienced in models neglecting cloud chemical interactions. In the present study, the existence of clouds, cloud types, and their lifetimes are modeled as pseudo random variables. Such pseudo random sequences are in reality deterministic and may, given the same starting values, be reproduced. The effects of cloud interactions on the overall chemistry of the troposphere are discussed. In particular, tests are performed to determine the sensitivity of cloud frequencies and cloud types
Gastronomicscape: Determinants of Gastronomic Tourism Experience and Loyalty
This study aims to examine the factors that contribute to the development of a favorable gastronomy tourism experience, by exploring the interrelationship among gastronomicscape dimensions (gastronomic quality, gastronomic image, social interaction, and price value), gastronomic attitude, gastronomic motivation, gastronomic satisfaction, and behavioral intention grounded in the Theory of Planned Behavior, the research collected empirical data from tourists visiting gastronomy destination. Partial least squares-structural equation
modeling (PLS-SEM) was employed to analyze the combined and simultaneous impact of gastronomicscape dimensions on the perceived quality of gastronomy tourism experiences. The results demonstrated that the positive perception of gastronomicscape dimensions significantly and directly influences both gastronomic satisfaction and behavioral intention among tourists. The result revealed that measuring the perceived gastronomic attitude and motivation towards gastronomiscape experience of tourist strongly influence the formation of gastronomic satisfaction and loyalty. Additionally, the study reveals that the investigation of gastronomy tourism experience necessitates a comprehensive examination of collective and intersecting factors that encompass behavioral
motivation and satisfaction. Consequently, this research provides a valuable framework in understanding gastronomic motivation and offers practical implications for the industry players to provide strategic approach in
satisfying gastronomy tourism experience
Assessing the costs and environmental benefits of IMO regulations of ship-originated SOx and NOx emissions in the Baltic Sea
To assess the value of the environmental benefits of the Sulphur
Emission regulation (SECA) that came into force in 2015, changes in
depositions of SOx and NOx from ship exhaust gas emissions were modelled
and monetized for the Baltic Sea region for the years 2014 and 2016.
During this period, the total deposition of SOx in the study area
decreased by 7.3%. The decrease in ship-originated SOx deposition from
38 kt to 3.4 kt (by over 88%) was translated into a monetary value for
the ecosystem impacts of nearly 130 million USD, according to the
EcoValue08 model. This is less than the modelled health benefits, but it
is not insignificant. For NOx, there was no decreasing trend. The
exceedance of the critical loads of SOx and NOx was also estimated. The
effect of Baltic shipping on the exceedance of critical loads of
acidification after SECA is very small, but Baltic shipping still has a
considerable effect on the exceedance of critical loads for
eutrophication.</p
Implementation and evaluation of updated photolysis rates in the EMEP MSC-W chemical transport model using Cloud-J v7.3e
The present work describes the implementation of the state of the art Cloud-J v7.3 photolysis rate calculation code in the EMEP MSC-W chemistry-transport model. Cloud-J calculates photolysis rates and accounts for cloud and aerosol optical properties at model run time, replacing the old system based on tabulated values. The performance of Cloud-J is evaluated against aerial photolysis rate observations made over the Pacific Ocean and against surface observations from three measurement sites in Europe. Numerical experiments are performed to investigate the sensitivity of the calculated photolysis rates to the spatial and temporal model resolution, input meteorology model, simulated ozone column, and cloud effect parameterization. These experiments indicate that the calculated photolysis rates are most sensitive to the choice of input meteorology model and cloud effect parameterization while also showing that surface ozone photolysis rates can vary by up to 20 % due to daily variations in total ozone column. Further analysis investigates the impact of Cloud-J on the oxidizing capacity of the troposphere, aerosolâphotolysis interactions, and surface air quality predictions. Results find that the annual mean mass-weighted tropospheric hydroxyl concentration is increased by 26 %, while the photolytic impact of aerosols is mostly limited to large tropical biomass-burning regions. Overall, Cloud-J represents a major improvement over the tabulated system, leading to improved model performance for predicting carbon monoxide and daily maximum ozone surface concentrations
Actininopathy : A new muscular dystrophy caused by ACTN2 dominant mutations
Objective To clinically and pathologically characterize a cohort of patients presenting with a novel form of distal myopathy and to identify the genetic cause of this new muscular dystrophy. Methods We studied 4 families (3 from Spain and 1 from Sweden) suffering from an autosomal dominant distal myopathy. Affected members showed adult onset asymmetric distal muscle weakness with initial involvement of ankle dorsiflexion later progressing also to proximal limb muscles. Results In all 3 Spanish families, we identified a unique missense variant in the ACTN2 gene cosegregating with the disease. The affected members of the Swedish family carry a different ACTN2 missense variant. Interpretation ACTN2 encodes for alpha actinin2, which is highly expressed in the sarcomeric Z-disk with a major structural and functional role. Actininopathy is thus a new genetically determined distal myopathy. ANN NEUROL 2019;85:899-906.Peer reviewe
Health impact of air pollution from shipping in the baltic sea : effects of different spatial resolutions in Sweden
In 2015, stricter regulations to reduce sulfur dioxide emissions and particulate air pollution
from shipping were implemented in the Baltic Sea. We investigated the effects on population exposure
to particles <2.5 ”m (PM2.5) from shipping and estimated related morbidity and mortality in Swedenâs
21 counties at different spatial resolutions. We used a regional model to estimate exposure in
Sweden and a city-scale model for Gothenburg. Effects of PM2.5 exposure on total mortality, ischemic
heart disease, and stroke were estimated using exposureâresponse functions from the literature
and combining them into disability-adjusted life years (DALYS). PM2.5 exposure from shipping in
Gothenburg decreased by 7% (1.6 to 1.5 ”g/m3
) using the city-scale model, and 35% (0.5 to 0.3 ”g/m3
)
using the regional model. Different population resolutions had no effects on population exposures.
In the city-scale model, annual premature deaths due to shipping PM2.5 dropped from 97 with
the high-sulfur scenario to 90 in the low-sulfur scenario, and in the regional model from 32 to 21.
In Sweden, DALYs lost due to PM2.5 from Baltic Sea shipping decreased from approximately 5700 to
4200. In conclusion, sulfur emission restrictions for shipping had positive effects on health, but the
model resolution affects estimations.Interreg Baltic Sea Region Program and Sahlgrenska University Hospital under the ALF agreement.http://www.mdpi.com/journal/ijerphpm2021School of Health Systems and Public Health (SHSPH
Hall-conductivity sign change and fluctuations in amorphous NbGe films
The sign change in the Hall conductivity has been studied in thin amorphous
NbGe0.3) films. By changing the film thickness it is
shown that the field at which the sign reversal occurs shifts to lower values
(from above to below the mean-field transition field ) with increasing
film thickness. This effect can be understood in terms of a competition between
a positive normal and a negative fluctuation contribution to the Hall
conductivity.Comment: 5 pages, 4 figures, to appear in Phys. Rev.
Genomic and strontium isotope variation reveal immigration patterns in a Viking Age town
The impact of human mobility on the northern European urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia itself are still largely unexplored. Our study of the demographics in the final phase of the Viking era is the first comprehensive multidisciplinary investigation that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier common pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 individuals from the 10th to 12th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed variation exceeds the genetic diversity in distinct modern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople. Our results uncover the social system underlying the urbanization process of the Viking World of which mobility was an intricate part and was comparable between males and females. The inhabitants of Sigtuna were heterogeneous in their genetic affinities, probably reflecting both close and distant connections through an established network, confirming that early urbanization processes in northern Europe were driven by migration
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