1,475 research outputs found
An overview of forest management and change with respect to environmental protection in the UK
International audienceThis paper overviews changes in forest management in the UK with respect to environmental protection. The evolution of policy is explained from historical and sustainability perspectives and covers developments in forest planning, accreditation, devolution and future challenges and opportunities. Keywords: forest management, best practice, sustainable forestry, environmental protection, land use chang
Methane Mitigation:Methods to Reduce Emissions, on the Path to the Paris Agreement
The atmospheric methane burden is increasing rapidly, contrary to pathways compatible with the goals of the 2015 United Nations Framework Convention on Climate Change Paris Agreement. Urgent action is required to bring methane back to a pathway more in line with the Paris goals. Emission reduction from âtractableâ (easier to mitigate) anthropogenic sources such as the fossil fuel industries and landfills is being much facilitated by technical advances in the past decade, which have radically improved our ability to locate, identify, quantify, and reduce emissions. Measures to reduce emissions from âintractableâ (harder to mitigate) anthropogenic sources such as agriculture and biomass burning have received less attention and are also becoming more feasible, including removal from elevated-methane ambient air near to sources. The wider effort to use microbiological and dietary intervention to reduce emissions from cattle (and humans) is not addressed in detail in this essentially geophysical review. Though they cannot replace the need to reach ânet-zeroâ emissions of CO2, significant reductions in the methane burden will ease the timescales needed to reach required CO2 reduction targets for any particular future temperature limit. There is no single magic bullet, but implementation of a wide array of mitigation and emission reduction strategies could substantially cut the global methane burden, at a cost that is relatively low compared to the parallel and necessary measures to reduce CO2, and thereby reduce the atmospheric methane burden back toward pathways consistent with the goals of the Paris Agreement
The local adsorption structure of benzene on Si(001)-(2 Ă 1): a photoelectron diffraction investigation
Scanned-energy mode C 1s photoelectron diffraction has been used to investigate the local adsorption geometry of benzene on Si(001) at saturation coverage and room temperature. The results show that two different local bonding geometries coexist, namely the 'standard butterfly' (SB) and 'tilted bridge' (TB) forms, with a composition of 58 ± 29% of the SB species. Detailed structural parameter values are presented for both species including SiâC bond lengths. On the basis of published measurements of the rate of conversion of the SB to the TB form on this surface, we estimate that the timescale of our experiment is sufficient for achieving equilibrium, and in this case our results indicate that the difference in the Gibbs free energy of adsorption, ÎG(TB)âÎG(SB), is in the range â0.023 to +0.049 eV. We suggest, however, that the relative concentration of the two species may also be influenced by a combination of steric effects influencing the kinetics, and a sensitivity of the adsorption energies of the adsorbed SB and TB forms to the nature of the surrounding benzene molecules
30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being
There is a need to increase peopleâs engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature
Making electromagnetic wavelets
Electromagnetic wavelets are constructed using scalar wavelets as
superpotentials, together with an appropriate polarization. It is shown that
oblate spheroidal antennas, which are ideal for their production and reception,
can be made by deforming and merging two branch cuts. This determines a unique
field on the interior of the spheroid which gives the boundary conditions for
the surface charge-current density necessary to radiate the wavelets. These
sources are computed, including the impulse response of the antenna.Comment: 29 pages, 4 figures; minor corrections and addition
Studying patterns of use of transport modes through data mining - Application to U.S. national household travel survey data set
Data collection activities related to travel require large amounts of financial and human resources to be conducted successfully. When available resources are scarce, the information hidden in these data sets needs to be exploited, both to increase their added value and to gain support among decision makers not to discontinue such efforts. This study assessed the use of a data mining technique, association analysis, to understand better the patterns of mode use from the 2009 U.S. National Household Travel Survey. Only variables related to self-reported levels of use of the different transportation means are considered, along with those useful to the socioeconomic characterization of the respondents. Association rules potentially showed a substitution effect between cars and public transportation, in economic terms but such an effect was not observed between public transportation and nonmotorized modes (e.g., bicycling and walking). This effect was a policy-relevant finding, because transit marketing should be targeted to car drivers rather than to bikers or walkers for real improvement in the environmental performance of any transportation system. Given the competitive advantage of private modes extensively discussed in the literature, modal diversion from car to transit is seldom observed in practice. However, after such a factor was controlled, the results suggest that modal diversion should mainly occur from cars to transit rather than from nonmotorized modes to transi
Highly Efficient Source for Indistinguishable Photons of Controlled Shape
We demonstrate a straightforward implementation of a push-button like
single-photon source which is based on a strongly coupled atom-cavity system.
The device operates intermittently for periods of up to 100 microseconds, with
single-photon repetition rates of 1.0 MHz and an efficiency of 60 %. Atoms are
loaded into the cavity using an atomic fountain, with the upper turning point
near the cavity's mode centre. This ensures long interaction times without any
disturbances induced by trapping potentials. The latter is the key to reaching
deterministic efficiencies as high as obtained in probabalistic
photon-heralding schemes. The price to pay is the random loading of atoms into
the cavity and the resulting intermittency. However, for all practical
purposes, this has a negligible impact
The Middle Holocene mangrove shellfish gatherers of Las Bela coast (Balochistan, Pakistan): new AMS dates from Lake Siranda shell middens
The discovery and AMS dating of many shell middens along the shores of the dry basin of Lake Siranda (Las Bela, Balochistan, Pakistan) have shown that it was a lagoon in the northern coast of the Arabian Sea in Neolithic times, densely settled by communities of mangrove shellfish gatherers
Effects of antibiotic-suppelmented media on recovery of enterobacteria
The frequency at which Salmonella typhimurium (ST) and Escherichia coli were recovered from tryptic soy agar (TSA), brilliant green agar (BGA) and MacConkey agar (MAC) alone or supplemented with 2 and 16 ”g kanamycin and 0.25 and 2 ”g enrofloxacin was investigated
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