200 research outputs found
Heavy metal accumulation in Artemisia and foliaceous lichen species from the Azerbaijan flora
Artemisia plants and foliaceous lichens are known to be capable of accumulating heavy metals (HM) from soil and air. These plant species are widespread on polluted sites of Azerbaijan. However, so far their capacity to accumulate HM in their shoots and roots has not been tested. Three Artemisia and two lichen species were collected from different contaminated sites of Azerbaijan. Plant and surface soil samples were measured for Cd, Cu, Pb, Ni and Zn concentrations by ICP-AES.The results indicated that among the Artemisia species A. scoparia showed the best HM accumulation properties. Lichen species were also distinguished by very high amounts of HM in their biomass, while in surrounding soil samples HM concentrations had higher contents than the soils occupied only with Artemisia species.The results indicate that on contaminated sites Artemisia and lichens accumulated metals in their biomass without toxicity symptoms. Taking large biomass and high adaptation ability into account, A. scoparia represents a good tool for a phytoremediation approach on polluted soils
Positiivisen psykologian näkökulma trauman seurauksiin:posttraumaattista kasvua edistävät tekijät
Tiivistelmä. Tässä kandidaatin tutkielmassa tarkastellaan traumaattisia tapahtumia positiivisen psykologian näkökulmasta. Nykykirjallisuudessa trauma määritellään äkilliseksi tapahtumaksi, joka järkyttävyydellään aiheuttaa poikkeavaa stressiä yksilölle ja voimakkuudellaan ravisuttelee sisäistettyä todellisuutta sekä ydinarvoja. Traumaattinen tapahtuma laukaisee yksilössä psyykkisen kriisin, joka häiriintyessään johtaa mielen oireiluun. Positiivinen psykologia kuitenkin näkee traumassa myös mahdollisuuden psyykkiseen kasvuun ja vahvistumiseen. Mikäli yksilö onnistuu sopeutumaan trauman aiheuttamaan kokonaisvaltaiseen muutokseen, voi prosessi johtaa psykologisen kamppailun seurauksena esimerkiksi elämän arvostuksen lisääntymiseen, ihmissuhteiden syventymiseen sekä omien vahvuuksien tiedostamiseen — posttraumaattiseen kasvuun. Kuvailevana kirjallisuuskatsauksena toteutetussa tutkielmassa tarkoituksena on eritellä yksilöllisiä sekä ympäristöllisiä tekijöitä, jotka edistävät tätä myönteistä kasvua koetun traumaattisen tapahtuman jälkeen tai sitä edeltäen.
Tutkimustulokset osoittivat, että posttraumaattista kasvua edistävät tekijät näyttäytyvät tutkimuksissa laajakirjoisina. Tuloksissa esiintyvien ominaisuuksien pohjalta kyettiin muodostamaan kokonaiskuva yksilön sopeutumiskyvyn sekä myönteisten, sopeutumista edistävien selviytymiskeinojen hyödyntämisen merkityksestä traumaattisessa kriisissä. Kirjallisuudessa kyseiset elementit liitetään etenkin resilienssin käsitteeseen. Katsauksen tulokset puolsivat täten kiisteltyä näkemystä siitä, että yksilön resilienssin vahvistaminen on keskeisessä roolissa posttraumaattisen kasvun vahvistamisessa. Puolestaan ympäristön tarjoama sosiaalinen tuki näyttäytyi merkittävänä etenkin traumaattisen kriisin jälkeisissä vaiheissa, sekä mikäli yksilölliset edistävät tekijät eivät olleet riittäviä posttraumaattisen kasvun muodostumiseksi. Täten tämän tutkielman pohjalta posttraumaattisen kasvun edistämiseksi ehdotetaan resilienssiä vahvistavien elementtien vaalimista ja riittävän sosiaalisen tuen tarjoamista trauman kokeneille yksilöille
Upstream structural management measures for an urban area flooding in Turkey
In recent years, flooding has become an increasing concern across many parts of the world of both the general public and their governments. The climate change inducing more intense rainfall events occurring in short period of time lead flooding in rural and urban areas. In this study the flood modelling in an urbanized area, namely Samsun-Terme in Blacksea region of Turkey is performed. MIKE21 with flexible grid is used in 2-dimensional shallow water flow modelling. 1 x 1000(-1) scaled maps with the buildings for the urbanized area and 1 x 5000(-1) scaled maps for the rural parts are used to obtain DTM needed in the flood modelling. The bathymetry of the river is obtained from additional surveys. The main river passing through the urbanized area has a capacity of 500 m(3) s(-1) according to the design discharge obtained by simple ungauged discharge estimation depending on catchment area only. The upstream structural base precautions against flooding are modelled. The effect of four main upstream catchments on the flooding in the downstream urban area are modelled as different scenarios. It is observed that if the flow from the upstream catchments can be retarded through a detention pond constructed in one of the upstream catchments, estimated Q(100) flood can be conveyed by the river without overtopping from the river channel. The operation of the upstream detention ponds and the scenarios to convey Q(500) without causing flooding are also presented. Structural management measures to address changes in flood characteristics in water management planning are discussed
Radiological Mapping of Post-disaster Nuclear Environments Using Fixed-wing Unmanned Aerial Systems:A Study from Chernobyl
In the immediate aftermath following a large-scale release of radioactive material into the environment, it is necessary to determine the spatial distribution of radioactivity quickly. At present, this is conducted by utilizing manned aircraft equipped with large-volume radiation detection systems. Whilst these are capable of mapping large areas quickly, they suffer from a low spatial resolution due to the operating altitude of the aircraft. They are also expensive to deploy and their manned nature means that the operators are still at risk of exposure to potentially harmful ionizing radiation. Previous studies have identified the feasibility of utilizing unmanned aerial systems (UASs) in monitoring radiation in post-disaster environments. However, the majority of these systems suffer from a limited range or are too heavy to be easily integrated into regulatory restrictions that exist on the deployment of UASs worldwide. This study presents a new radiation mapping UAS based on a lightweight (8 kg) fixed-wing unmanned aircraft and tests its suitability to mapping post-disaster radiation in the Chornobyl Exclusion Zone (CEZ). The system is capable of continuous flight for more than 1 h and can resolve small scale changes in dose-rate in high resolution (sub-20 m). It is envisaged that with some minor development, these systems could be utilized to map large areas of hazardous land without exposing a single operator to a harmful dose of ionizing radiation
Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg day Data of the CDEX-10 Experiment
We report the first results of a light weakly interacting massive particles
(WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector
array immersed in liquid nitrogen at the China Jinping Underground Laboratory
with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee,
improved limits of 8 and 3 cm at a
90\% confidence level on spin-independent and spin-dependent WIMP-nucleon cross
sections, respectively, at a WIMP mass () of 5 GeV/ are
achieved. The lower reach of is extended to 2 GeV/.Comment: 5 pages, 4 figure
Neutron background measurements with a hybrid neutron detector at the Kuo-Sheng Reactor Neutrino Laboratory
We report in situ neutron background measurements at the Kuo-Sheng Reactor
Neutrino Laboratory (KSNL) by a hybrid neutron detector (HND) with a data size
of 33.8 days under identical shielding configurations as during the neutrino
physics data taking. The HND consists of BC-501A liquid and BC-702 phosphor
powder scintillation neutron detectors, which is sensitive to both fast and
thermal neutrons, respectively. Neutron-induced events for the two channels are
identified and differentiated by pulse shape analysis, such that background of
both are simultaneously measured. The fast neutron fluxes are derived by an
iterative unfolding algorithm. Neutron induced background in the germanium
detector under the same fluxes, both due to cosmic-rays and ambient
radioactivity, are derived and compared with the measurements. The results are
valuable to background understanding of the neutrino data at the KSNL. In
particular, neutron-induced background events due to ambient radioactivity as
well as from reactor operation are negligible compared to intrinsic cosmogenic
activity and ambient -activity. The detector concept and analysis
procedures are applicable to neutron background characterization in similar
rare-event experiments.Comment: 12 pages, 29 figure
The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)
The observation of neutrinoless double-beta decay (0)
would show that lepton number is violated, reveal that neutrinos are Majorana
particles, and provide information on neutrino mass. A discovery-capable
experiment covering the inverted ordering region, with effective Majorana
neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with
excellent energy resolution and extremely low backgrounds, at the level of
0.1 count /(FWHMtyr) in the region of the signal. The
current generation Ge experiments GERDA and the MAJORANA DEMONSTRATOR
utilizing high purity Germanium detectors with an intrinsic energy resolution
of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in
the 0 signal region of all 0
experiments. Building on this success, the LEGEND collaboration has been formed
to pursue a tonne-scale Ge experiment. The collaboration aims to develop
a phased 0 experimental program with discovery potential
at a half-life approaching or at years, using existing resources as
appropriate to expedite physics results.Comment: Proceedings of the MEDEX'17 meeting (Prague, May 29 - June 2, 2017
Ceramic Microbial Fuel Cells Stack: Power generation in standard and supercapacitive mode
© 2018 The Author(s). In this work, a microbial fuel cell (MFC) stack containing 28 ceramic MFCs was tested in both standard and supercapacitive modes. The MFCs consisted of carbon veil anodes wrapped around the ceramic separator and air-breathing cathodes based on activated carbon catalyst pressed on a stainless steel mesh. The anodes and cathodes were connected in parallel. The electrolytes utilized had different solution conductivities ranging from 2.0 mScm-1 to 40.1 mScm-1, simulating diverse wastewaters. Polarization curves of MFCs showed a general enhancement in performance with the increase of the electrolyte solution conductivity. The maximum stationary power density was 3.2 mW (3.2 Wm-3) at 2.0 mScm-1 that increased to 10.6 mW (10.6 Wm-3) at the highest solution conductivity (40.1 mScm-1). For the first time, MFCs stack with 1 L operating volume was also tested in supercapacitive mode, where full galvanostatic discharges are presented. Also in the latter case, performance once again improved with the increase in solution conductivity. Particularly, the increase in solution conductivity decreased dramatically the ohmic resistance and therefore the time for complete discharge was elongated, with a resultant increase in power. Maximum power achieved varied between 7.6 mW (7.6 Wm-3) at 2.0 mScm-1 and 27.4 mW (27.4 Wm-3) at 40.1 mScm-1
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