Surface-Enhanced Nitrate Photolysis on Ice

Heterogeneous nitrates photolysis is the trigger for many chemical processes occurring in the polar boundary layer and is widely believed to occur in a quasi-liquid layer (QLL) at the surface of ice. The dipole forbidden character of the electronic transition relevant to boundary layer atmospheric chemistry and the small photolysis/photoproducts quantum yields in ice (and in water) may confer a significant enhancement and interfacial specificity to this important photochemical reaction at the surface of ice. Using amorphous solid water films at cryogenic temperatures as models for the disordered interstitial air/ice interface within the snowpack suppresses the diffusive uptake kinetics thereby prolonging the residence time of nitrate anions at the surface of ice. This approach allows their slow heterogeneous photolysis kinetics to be studied providing the first direct evidence that nitrates adsorbed onto the first molecular layer at the surface of ice are photolyzed more effectively than those dissolved within the bulk. Vibrational spectroscopy allows the ~3-fold enhancement in photolysis rates to be correlated with the nitrates’ distorted intramolecular geometry thereby hinting at the role played by the greater chemical heterogeneity in their solvation environment at the surface of ice than in the bulk. A simple 1D kinetic model suggests 1-that a 3(6)-fold enhancement in photolysis rate for nitrates adsorbed onto the ice surface could increase the photochemical NO[subscript 2] emissions from a 5(8) nm thick photochemically active interfacial layer by 30%(60)%, and 2-that 25%(40%) of the NO[subscript 2] photochemical emissions to the snowpack interstitial air are released from the top-most molecularly thin surface layer on ice. These findings may provide a new paradigm for heterogeneous (photo)chemistry at temperatures below those required for a QLL to form at the ice surface

The Essential Role for Laboratory Studies in Atmospheric Chemistry

Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This article highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines

The Essential Role for Laboratory Studies in Atmospheric Chemistry

Laboratory studies of atmospheric chemistry characterize the nature of atmospherically relevant processes down to the molecular level, providing fundamental information used to assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor air quality, and stratospheric ozone depletion. Laboratory studies have a central role in addressing the incomplete fundamental knowledge of atmospheric chemistry. This article highlights the evolving science needs for this community and emphasizes how our knowledge is far from complete, hindering our ability to predict the future state of our atmosphere and to respond to emerging global environmental change issues. Laboratory studies provide rich opportunities to expand our understanding of the atmosphere via collaborative research with the modeling and field measurement communities, and with neighboring disciplines

Biodiversity protection on wetlands of national parks

W artykule przedstawiono w ogólnym zarysie analizę problemu niekontrolowanej sukcesji roślinności na obszarach wodno-błotnych, głównie parków narodowych. Pokazano ponadto sposoby wykonywania za pomocą dostępnych technologii zabiegów ochronnych ograniczających tę sukcesję oraz dokonano ich oceny pod kątem oddziaływania na środowisko naturalne. Przedstawiono koncepcję poduszkowcowego nośnika narzędzi do wykonywania zabiegów ograniczających sukcesję roślinności.The paper presents an overview of the analysis of the problem of uncontrolled vegetation succession on wetlands of national parks. Moreover, it shows how to perform protective treatments that used available technologies against succession and evaluated them from the point of view of environmental impact. The article presents the concept of hovercraft tool carrier to perform the procedures reducing vegetation succession

PIMR tracked vehicle : design modifications of the grass cutting module and module for removing shrubs in swampy areas

W artykule przedstawiono prace badawczo-rozwojowe dotyczące specjalistycznego pojazdu gąsienicowego PIMR związane z badaniami jego modułu roboczego, służącego do koszenia traw (turzyce, trzciny) oraz modułu do usuwania zakrzaczeń na chronionych terenach wodno-błotnych parków narodowych, parków krajobrazowych i obszarów Natura 2000. Przeprowadzone wstępne testy terenowe wskazywały na celowość dokonania modyfikacji konstrukcji obu modułów celem poprawy ich funkcjonalności i niezawodności działania. Próby terenowe potwierdziły korzyści z wprowadzonych modyfikacji konstrukcyjnych obu modułów roboczych dla poprawy jakości i efektywności pracy pojazdu gąsienicowego w terenie bagnistym.Paper presents research and development concerning a specialized PIMR tracked vehicle related to the study of its working modules used for mowing grass (sedges, reeds) and a module for removing shrubs in protected wetlands of national parks, landscape parks and Natura 2000 sites. Initial field trails carried out indicated the desirability of modifying the design of both modules to improve their functionality and operational reliability. The field tests confirmed the benefits of the introduced construction modifications of both working modules to improve the quality and work efficiency of the tracked vehicle in the marshy terrain

PIMR tracked vehicle - design modifications of the grass cut-ting module and module for removing shrubs in swampy areas

W artykule przedstawiono prace badawczo-rozwojowe dotyczące specjalistycznego pojazdu gąsienicowego PIMR związane z badaniami jego modułu roboczego, służącego do koszenia traw (turzyce, trzciny) oraz modułu do usuwania zakrzaczeń na chronionych terenach wodno-błotnych parków narodowych, parków krajobrazowych i obszarów Natura 2000. Przeprowadzone wstępne testy terenowe wskazywały na celowość dokonania modyfikacji konstrukcji obu modułów celem poprawy ich funkcjonalności i niezawodności działania. Próby terenowe potwierdziły korzyści z wprowadzonych modyfikacji konstrukcyjnych obu modułów roboczych dla poprawy jakości i efektywności pracy pojazdu gąsienicowego w terenie bagnistym.Paper presents research and development concerning a specialized PIMR tracked vehicle related to the study of its working modules used for mowing grass (sedges, reeds) and a module for removing shrubs in protected wetlands of national parks, landscape parks and Natura 2000 sites. Initial field trails carried out indicated the desirability of modifying the design of both modules to improve their functionality and operational reliability. The field tests confirmed the benefits of the introduced construction modifications of both working modules to improve the quality and work efficiency of the tracked vehicle in the marshy terrain

Bis(trifluoromethyl)methylene addition to vinyl-terminated SAMs : a gas-phase C–C bond-forming reaction on a surface

The authors acknowledge the Scottish Funding Council for a SPIRIT Studentship (M.A.) and the EPSRC (EP/K000411/1) for financial support, and D.O’H. acknowledges the European Research Council for an Advanced Grant and the Royal Society for a Wolfson Research Merit Award.Vinyl-terminated self-assembled monolayers (SAMs) on silicon oxide substrates were chemically modified by the addition of a bis(trifluoromethyl)methylene group in a rare gas-phase C–C bond-forming reaction to directly generate films carrying terminal CF3 groups. The vinyl-terminated films were treated with hexafluoroacetone azine (HFAA) for modification. The films were characterized with ellipsometry, contact angle measurements, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). In this study, we find that for optimized conditions clean reactions occur on a surface between SAMs with terminal olefins and HFAA, and the product is consistent with bis(trifluoromethyl)cyclopropanation formation after nitrogen extrusion.Publisher PDFPeer reviewe

Additional buoyancy tanks for off-road vehicles : to improve the work safety and efficiency of movement on lakes and wetlands

W artykule przedstawiono konstrukcję i sposób montażu nowej wersji zbiorników wypornościowych na zespole pojazdów gąsienicowych PIMR, które przeznaczone są do pracy w trudnym wodno-błotnym terenie. Nowej wydłużonej wersji zbiorniki wypornościowe zapewniają wystarczającą pływalność zespołu pojazdów gąsienicowych wraz z modułami roboczymi oraz poprawiają efektywność poruszania się po grząskich terenach pokrytych kilku centymetrową warstwą wody. Przeniesienie pędników śrubowych z kadłuba pojazdu gąsienicowego na rufową część zbiorników wypornościowych - poprawiło efektywność napędu, prędkość pływania wzrosła o około 60%. Nowe dodatkowe zbiorniki wypornościowe są przeznaczone do mocowania w pojazdach pozadrogowych i wpływają istotnie na poprawę poziomu bezpieczeństwa pracy i efektywności ich poruszania.The paper presents the design and mounting of a new version of the buoyancy tanks for the PIMR’s tracked vehicles unit, which i designed for work on wetlands. The new longer version of tanks provide sufficient buoyancy of tracked vehicles unit with mounted on them modules and work tools, and should improve the efficiency of moving the vehicles on the muddy areas covered by several cm layer of water. Transfer of the propulsion system of the hull of the tracked vehicle to the aft part of the buoyancy tank - improved drive efficiency, speed in water has increased by approx. 60%. Assembly of the buoyancy tanks in these vehicles should improve the level of work safety and vehicles efficiency of moving