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Kensington, Australia

Kinal J.,Science Division | Stoneman G.L.,Sustainable Forest Management Division
Journal of Hydrology | Year: 2011

The hydrological impact of two different intensities of timber harvest and associated silviculture, one standard and the other more intensive, was investigated using a paired-catchment study in jarrah forest in south-western Australia. This study was undertaken during a period when average annual rainfall was below the long-term average and deep groundwater levels were declining. Following treatment, recharge increased and slowed the decline in deep groundwater levels in proportion to the magnitude of the initial reduction in vegetation density. However, neither treatment was sufficiently intense to reverse the continued decline in groundwater levels over the course of the study. Annual stream salinity did not increase in response to either treatment because saline deep groundwater did not rise following the treatments. Annual streamflow did not increase in either catchment for three reasons. Firstly, there was little additional net precipitation to the intermittent shallow perched groundwater system in the streamzone because the area remained untreated. Secondly, there was minimal additional throughflow to the perched groundwater system in the streamzone from upslope areas because the increased net precipitation in hillslope areas following treatment was used in replenishing the progressively increasing soil moisture deficit. Thirdly, because groundwater levels did not rise and hence there was little prospect for an increased discharge of saline groundwater or of an expanded deep groundwater discharge zone. This study has demonstrated that the measures that were implemented to timber harvest and silvicultural methods to reduce the magnitude of the groundwater response and hence the risk of a transient increase in stream salinity are effective. If annual rainfall remains relatively low and deep groundwater levels remain at current levels or decline further, then the risk of an increase in stream salinity from either the standard or the more intensive harvest and silviculture will be low. © 2011. Source


Kinal J.,Science Division | Stoneman G.L.,Sustainable Forest Management Division
Journal of Hydrology | Year: 2012

In south-western Australia, significant declines in annual rainfall in recent decades have been accompanied by even greater declines in annual streamflow. The disproportionate decline in annual streamflow is perplexing and while there has been speculation about the causes, the mechanisms responsible for the disproportionate decline have not been demonstrated. This study seeks to clarify the role of groundwater in the disproportionate decline in annual streamflow in a small catchment in the jarrah forest by examining records of annual streamflow, stream salinity and groundwater which progressively declined from 1976 to 2011. The records span the transition from connected groundwater-surface water systems to disconnected. This provided a unique opportunity to differentiate the groundwater contribution to streamflow for two reasons. Firstly, because the change in streamflow following disconnection can be largely attributed to streamflow that was previously generated because groundwater was connected. Secondly, because groundwater was the main source of stream salinity and hence stream salinity was a natural tracer which indicated the presence and relative proportion of groundwater in streamflow.Disconnection occurred around 2001 and was signalled by a change in the annual stream salinity signature from moderately high and variable, to low and constant, and by the transition in piezometric levels at the catchment outlet from mostly above ground, to mostly below ground. Following disconnection, the average runoff coefficient which had been slowly declining, abruptly fell by more than half and subsequently remained relatively low and constant. This indicated that whilst groundwater was connected it played a key role in streamflow generation. The contribution by groundwater to streamflow generation was non-linear and was dominant at higher rainfalls.The annual stream salinity signature indicated that direct groundwater discharge to the stream was a relatively minor component, especially at higher rainfalls. Hence connected groundwater contributed to streamflow generation mostly indirectly, thus amplifying other streamflow-generating processes, by facilitating additional surface runoff and/or throughflow which were relatively fresh. As groundwater levels, and hence connectivity, declined, the amplifying effect of groundwater-facilitated streamflow generation also declined.We suggest that the large disparity between the rates of decline in annual rainfall and inflow into reservoirs elsewhere in the forests in south-western Australia mostly reflects the aggregate loss of connectivity in the catchments of streams contributing inflow into the reservoirs. © 2012. Source


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The top five candidates of the Gerhard Ertl Young Investigator Award 2016 that have qualified for the final round of selection, have been announced. These highly qualified candidates will be asked to give 30-minute (25 min. talk and 5 min. discussion) oral presentations in a special session at the DPG Spring Meeting of the Surface Science Division. The prize committee will then select the winner and she/he will receive a certificate plus the cash prize of EUR 3,000. The runner ups will receive  EUR 500 as recognition of their efforts. For more information, go to http://www.journals.elsevier.com/surface-science-including-surface-science-letters/awards/calling-for-papers-gerhard-ertl-young-investigator-award-201/


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Mars 2020 is targeted for launch in July 2020 aboard an Atlas V 541 rocket from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The rover will conduct geological assessments of its landing site on Mars, determine the habitability of the environment, search for signs of ancient Martian life, and assess natural resources and hazards for future human explorers. Additionally, scientists will use the instruments aboard the rover to identify and collect samples of rock and soil, encase them in sealed tubes, and leave them on the surface of Mars for potential return to Earth by a future mission to the Red Planet. The mission will build on the achievements of Curiosity and other Mars Exploration Program missions, and offer opportunities to deploy new capabilities developed through investments by NASA's Space Technology Program and Human Exploration and Operations Mission Directorate, as well as contributions from international partners. The Mars 2020 rover mission presents new opportunities to learn how future human explorers could use natural resources available on the surface of the Red Planet. An ability to live off the land could reduce costs and engineering challenges posed by Mars exploration. The total cost for NASA to launch Mars 2020 is approximately $243 million, which includes: the launch service; spacecraft and spacecraft power source processing; planetary protection processing; launch vehicle integration; and tracking, data and telemetry support. NASA is on an ambitious journey to Mars that includes sending humans to the Red Planet. The robotic missions of NASA's Planetary Science Division are leading the way with the upcoming Mars 2020 rover, the InSight lander mission targeted for 2018, Opportunity and Curiosity rovers currently exploring the Martian surface, Odyssey and Mars Reconnaissance Orbiter spacecraft currently orbiting the planet, and the Mars Atmosphere and Volatile Evolution Mission (MAVEN) orbiter, which is helping scientists understand what happened to the planet's atmosphere. More information: For more information about NASA's Mars 2020 rover, visit: mars.nasa.gov/mars2020/


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In a new study, researchers from the Cambridge Crystallographic Data Centre (CCDC) in the UK and the US Department of Energy’s (DOE’s) Argonne National Laboratory have teamed up to capture neon within a porous crystalline framework. Neon is the most unreactive element and is a key component in semiconductor manufacturing, but it has never been studied within an organic or metal-organic framework (MOF) until now. These new results, which include critical studies carried out at the Advanced Photon Source (APS), a DOE Office of Science user facility at Argonne, also point the way towards a more economical and greener industrial process for neon production. Although best known for its iconic use in neon signs, industrial applications of neon have recently become dominated by its use in excimer lasers to produce semiconductors. Despite being the fifth most abundant element in the atmosphere, the cost of pure neon gas has risen significantly over the years, increasing the demand for better ways to separate and isolate the gas. In 2015, CCDC scientists presented a talk at the annual American Crystallographic Association (ACA) meeting on the array of elements that have been studied within an organic or metal-organic environment. They challenged the crystallographic community to find the next and possibly last element to be added to the Cambridge Structural Database (CSD). A chance encounter at that meeting with Andrey Yakovenko, a beamline scientist at the APS, resulted in a collaborative project to capture neon – the 95th element to be observed in the CSD. Neon’s low reactivity, along with the weak scattering of X-rays due to its relatively low number of electrons, means that conclusive experimental observation of neon captured within a crystalline framework is very challenging. By conducting in situ high pressure gas flow experiments at X-Ray Science Division beamline 17-BM at the APS using the X-ray powder diffraction technique at low temperatures, the researchers have now managed to elucidate the structure of two different metal-organic frameworks (MOFs) with neon gas captured inside them. “This is a really exciting moment representing the latest new element to be added to the CSD and quite possibly the last given the experimental and safety challenges associated with the other elements yet to be studied” said Peter Wood, senior research scientist at the CCDC and lead author of a paper on this work in Chemical Communications. “More importantly, the structures reported here show the first observation of a genuine interaction between neon and a transition metal, suggesting the potential for future design of selective neon capture frameworks.” The structure of neon captured within a MOF known as NiMOF-74, a porous framework built from nickel metal centers and organic linkers, shows clear nickel-to-neon interactions forming at low temperatures. These interactions are significantly shorter than would be expected from a typical weak contact. “These fascinating results show the great capabilities of the scientific program at 17-BM and the Advanced Photon Source,” said Yakovenko. “Previously we have been doing experiments at our beamline using other much heavier, and therefore easily detectable, noble gases such as xenon and krypton. However, after meeting co-authors Pete, Colin, Amy and Suzanna at the ACA meeting, we decided to perform these much more complicated experiments using the very light and inert gas – neon. In fact, only by using a combination of in situ X-ray powder diffraction measurements, low temperature and high pressure have we been able to conclusively identify the neon atom positions beyond reasonable doubt”. “This is a really elegant piece of in situ crystallography research and it is particularly pleasing to see the collaboration coming about through discussions at an annual ACA meeting,” said Chris Cahill, past president of the ACA and professor of chemistry at George Washington University. This story is adapted from material from the Cambridge Crystallographic Data Centre, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.

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