Miracle-dz/UniFAR-FTUs huggingface dataset:
From molecular clusters to nanoparticles: Role of ambient ionization in tropospheric aerosol formation

We investigate the role of background ionization, associated mainly with galactic cosmic radiation, in the generation and evolution of ultrafine particles in the marine boundary layer. We follow the entire course of aerosol evolution, from the initial buildup of molecular clusters (charged and uncharged) through their growth into stable nanoparticles. The model used for this purpose is based on a unified collisional (kinetic) mechanism that treats the interactions between vapors, neutral and charged clusters, and particles at all sizes. We show that air ions are likely to play a central role in the formation of new ultrafine particles. The nucleation of aerosols under atmospheric conditions involves a series of competing processes, including molecular aggregation, evaporation, and scavenging by preexisting particles. In this highly sensitive nonlinear system, electrically charged embryos have a competitive advantage over similar neutral embryos. The charged clusters experience enhanced growth and stability as a consequence of electrostatic interactions. Simulations of a major nucleation event observed during the Pacific Exploratory Mission (PEM) Tropics-A can explain most of the observed features in the ultrafine particle behavior. The key parameters controlling this behavior are the concentrations of precursor vapors and the surface area of preexisting particles, as well as the background ionization rate. We find that systematic variations in ionization levels due to the modulation of galactic cosmic radiation by the solar cycle are sufficient to cause a notable variation in aerosol production. This effect is greatest when the ambient nucleation rate is limited principally by the availability of ions. Hence we conclude that the greatest influence of such ionization is likely to occur in and above the marine boundary layer. While a systematic change in the ultrafine particle production rate is likely to affect the population of cloud condensation nuclei and hence cloud optical properties, the magnitude of the effect cannot be directly inferred from the present analysis, and requires additional analysis based on specific aerosol-cloud interactions.
Using undisturbed columns to predict long term behaviour of effluent irrigated soils under field conditions

Soils only have a finite capacity for the removal of wastewater pollutants and with time this capacity could in fact decline. Not all soil types have the capacity to provide adequate treatment and dispersal of sewage effluent. For continued long term application to be successful, it is essential that infiltration and drainage characteristics of soils do not decline. Also it is critical how long term application of nutrients and cations affects the soils and whether any leaching occurs. The research project described in this paper compares the outcomes of detailed field studies with results from an undisturbed soil column study where typical soils in the South East region of Queensland State, Australia have been subjected to sewage effluent application over a period of 12 months. Multivariate analysis helped to classify the influential soil characteristics and to identify relative changes in each soil after the application of effluent. Identification and correlation of influential soil characteristics in field and accelerated column studies confirmed that undisturbed soil column studies can be useful in predicting long term behaviour of effluent irrigated soils.
Upper mantle cross section from Tonga to Newfoundland

A record section of long-period U.S. and Canadian observations of multibounce SH waves from a Tonga event is used to study lateral variation in the upper mantle. Source to receiver distances range from 81° to 131° with triplication patterns apparent in S4 for the western North America stations and S5 for the more distant stations. A corresponding synthetic section explaining the timing separation and waveform distortions for the various multiple S phases was derived by forward modeling. Initial trial models consisted of connecting existing pure path models, assuming ATL (old Atlantic) as an analog for the old Pacific, TNA for the western portion of the United States, and SNA for the shield portion of North America. Isovelocity depth contours were constructed to connect these models and corresponding synthetics were computed following a modified WKBJ method. Lateral heterogeneity is found to exist in the upper 350 km of the Pacific Ocean region and can be modeled reasonably well with a high-velocity lid (Vs = 4.7 km/s) which thickens with increasing oceanic crustal age at the expense of the underlying low-velocity zone. Velocities in the upper 200 km of the older southwest Pacific are found to be up to 6% faster than those at comparable depths in the younger tectonic region near western North America. The best fitting model indicates that the upper mantle structure of the old Pacific is similar to that of the old Atlantic, although perhaps slightly slower.
Plio-Pleistocene sedimentation in coastal grabens, north-east Rhodes, Greece

The stratigraphy of marine Plio-Pleistocene sediments from northeast Rhodes (Dodecanese islands, Greece) is revised in the light of facies mapping and the recognition of three major transgression–regression cycles. Before late Pliocene submergence, metamorphosed Mesozoic limestones formed a high-relief karstic landscape. During subsequent transgressions, subsiding basins with spectacular cliffed and bioeroded margins were infilled by a mosaic of carbonate-dominated sediments, sourced by high rates of carbonate productivity on narrow shelves rimming the basins and their drowning islands. Periods of relative sea-level fall superimposed a complex series of ‘fossil’ coastal geomorphological features such as cliffs, abrasion platforms, surf caves, notches, boulder beaches and palaeokarsts. These created the rugged present day topography of the island's northeast coast. Three main lithostratigraphic units, the Kritika, Rhodes and Lindos Acropolis Formations, are defined. The Rhodes and Lindos Acropolis Formations are subdivided into mappable facies groups rather than members, as the lithofacies are strongly diachronous. The Kritika and Rhodes Formations were each subaerially exposed and partly eroded before re-transgression. Although there is a general pattern of lithological succession, details vary across the study area and some facies groups are restricted in development, indicating differences in tectonic behaviour and palaeo-geomorphology between neighbouring basins. A preliminary process-response model is presented for the sedimentation history of the Rhodes and Lindos Acropolis Formations, using sedimentological, palaeontological, palaeoecological and ichnological data.
WRF Model Sensitivity to Land Surface Model and Cumulus Parameterization under Short-Term Climate Extremes over the Southern Great Plains of the United States

Extreme weather and climate events, especially short-term excessive drought and wet periods over agricultural areas, have received increased attention. The Southern Great Plains (SGP) is one of the largest agriculturalregionsinNorthAmericaandfeaturestheunderlyingOgallala-HighPlainsAquifersystemworth great economic value in large part due to production gains from groundwater. Climate research over the SGP isneededtobetterunderstandcomplexcoupledclimate‐hydrology‐socioeconomicinteractionscriticaltothe sustainability of this region, especially under extreme climate scenarios. Here the authors studied growingseason extreme conditionsusing the WeatherResearchand Forecasting(WRF) Model.The six most extreme recent years, both wet and dry, were simulated to investigate the impacts of land surface model and cumulus parameterization on the simulated hydroclimate. The results show that under short-term climate extremes, the land surface model plays a more important role modulating the land‐atmosphere water budget, and thus theentireregionalclimate,thanthecumulus parameterizationunder current model configurations.Betweenthe two land surface models tested, the more sophisticated land surface model produced significantly larger wet bias inlargepartduetooverestimationofmoisturefluxconvergence, which is attributedmainlytoanoverestimation ofthesurfaceevapotranspirationduringthesimulatedperiod.Thedeficienciesofthecumulusparameterizations resultedinthemodel’sinabilitytodepictthediurnalrainfallvariability.Bothlandsurfaceprocessesandcumulus parameterizations remain the most challenging parts of regional climate modeling under extreme climates over the SGP, with the former strongly affecting the precipitation amount and the latter strongly affecting the precipitation pattern.
Effect of soil surface amendments on runoff and erosion from simulated rain applied to a sesquioxidic soil

Simulated rainfall, using low conductivity water, was applied at an intensity of 63 mm h−1 to a field soil of the Doveton series (a kaolinitic, sesquioxidic clay soil at Cedara in Natal, recently cultivated out of pasture) after pre-treatment of the scarified soil surface with a mulch of maize stover, 200 kg ha−1 of sodium hexametaphosphate (applied in solution), or 10 000 kg ha−1 of industrial phosphogypsum. The decline in infiltration rate with cumulative rainfall was accelerated by the hexametaphosphate (final infiltration rate after 126 mm rain was 27 mm h−1 compared with 42 mm h−1 for the untreated control) and retarded by the gypsum (final IR=47 mm h−1) and mulch (53 mm h−1) treatments. After 60 mm of a second rain, final IR was 26 (control), 24 (hexametaphosphate), 35 (gypsum) and 26 mm h−1 (mulch). Laboratory-simulated rain produced a similar result with gypsum to that found in the field. Ultrasonic treatment of suspensions of the same soil showed (i) that with decreasing aggregate size, an increa.
Las principales discordancias del Mesozoico de la Cuenca Neuquina según observaciones de superficie

The main unconformities of the Mesozoic of the Neuquen Basin based on surface observations. A general summary of the main unconformities which produced major order break-ups during the evolution of the Mesozoic sedimentary infill of the Neuquen Basin is offered in this paper. Based on its hierarchy, they are categorized in three groups, as follows: 1) key unconformities widely spread along the whole basin; 2) «Intracuyan» unconformities related to the Dorsal de Huincul, and 3) «Intraprecuyan» unconformities restricted to isolated depocentres. Having into account tectonic, eustatic, paleoclimatic and/or paleontological aspects of the sedimentites situated below- and above of each unconformity, precisions about their ages are given. The number of the recognized key unconformities sums 10, as follows: Huarpican (Intratriassic), Rioatuelican (Intraliassic), Lotenican (Intracallovian), Araucanican (ca. Oxfordian/Kimmeridgian boundary), Huncalican (Intravalanginian), Coihuequican (Intrahauterivian), Pampatrilican (Intrabarremian), Pichineuquenican (Intraaptian), Patagonidican (ca. Albian/Cenomanian boundary) and Huantraiquican (Intracampanian). In relationship with the area realated with the Dorsal de Huincul, three «intracuyan» unconformities were identified, as follows: the Intratoarcian, only recognized at subsurface, the Seguelican (Intrabajocian 1) and the Lohanmahuidican (Intrabajocian 2). However, the influence of these unconformities diminish towards northern areas of the basin, as the distance increase with regard to the cited morphostructural element. The «intraprecuyan» unconformities recorded in the Cordillera del Viento and Chachil depocentres are of local character and less hierarchy. They are the result of short interruptions in the volcano-sedimentary infill of these halfgrabens. Given its geographical restriction to the cited depocentres, no formal names were ascribed to these unconformities. Once defined the key unconformities, a summary in three tables of genetically related formational units bounded by them, using the classical lithostratigraphic categorization in Groups, the latter ones basically coincident with the concept of tectosedimentary units (TSU), is presented. The obtained results lead to suggest some new ideas with regard to the evolution of the Neuquen Basin and to keep attention on still open nomenclatural problems.
Flood-Frequency Analyses from Paleoflood Investigations for Spring, Rapid, Boxelder, and Elk Creeks, Black Hills, Western South Dakota

Flood-frequency analyses for the Black Hills area are significant because of the severe flooding that occurred on June 9–10, 1972, that was instigated by a large mesoscale convective system and resulted in at least 238 fatalities. Many 1972 peak flows are high outliers (by factors of 10 or more) in observed records that date to the early 1900s. An effective and efficient way to reduce uncertainties for flood recurrence is to enhance gaged records by utilizing paleohydrologic techniques to ascertain ages and magnitudes of prior large floods (paleofloods). This report summarizes results of paleoflood investigations for Spring Creek, Rapid Creek (two reaches), Boxelder Creek (two subreaches), and Elk Creek. Stratigraphic records and resulting long-term flood chronologies, locally extending more than 2,000 years, were merged with observed and adjusted peak-flow values (gaged records) and historical flood information to derive flood-frequency estimates for the six study reaches. Results indicate that (1) floods as large as and even substantially larger than the 1972 flood have impacted most of the study reaches, and (2) incorporation of the paleohydrologic information enormously reduced uncertainties in estimating flood recurrence.
Urban heat islands in China

We used 1954–1983 surface temperature from 42 Chinese urban (average population 1.7*106) and rural (average population 1.5*105) station pairs to study the urban heat island effects. Despite the fact that the rural stations are not true rural stations, the magnitude of the heat islands was calculated to average 0.23 °C over the thirty-year period with a minimum value during the 1964–1973 decade and maximum during the most recent decade. The urban heat islands were found to have seasonal dependence which varied considerably across the country. The urban heat islands also had a strong regional dependence with the Northern Plains dominating the magnitude of the heat islands. The changes in heat island intensity over three decades studied suggest a general increase in heat island intensity of about 0.1°C, but this has not been constant in time. These results suggest that caution must be exercised when attributing causes to observed trends when stations are located in the vicinity of metropolitan areas.
Weekly cycle of lightning: Evidence of storm invigoration by pollution

We have examined summertime 1998–2009 U.S. lightning data from the National Lightning Detection Network (NLDN) to look for weekly cycles in lightning activity. As was found by Bell et al. (2008) for rain over the southeast U.S., there is a significant weekly cycle in afternoon lightning activity that peaks in the middle of the week there. The weekly cycle appears to be reduced over population centers. Lightning activity peaks on weekends over waters near the SE U.S. The statistical significance of weekly cycles over the western half of the country is generally small. We found no evidence of a weekly cycle of synoptic‐scale forcing that might explain these patterns. The lightning behavior is entirely consistent with the explanation suggested by Bell et al. (2008) for the cycles in rainfall and other atmospheric data from the SE U.S., that aerosols can cause storms to intensify in humid, convectively unstable environments.
Gamification in Workforce Management Systems

As the competition for software grows companies are searching for methods of keeping users interested and engaged with their solutions. One such method called gamification uses elements from games to increase motivation and engagement. As gamification is usually found in consumer-focused environments this thesis sought to research if gamification could be successfully incorporated into a professional environment. Researching and interviewing users and hypothesizing ideas resulted in potential solutions which were then visualized in interactive prototypes. Testing these prototypes showed results indicating that gamification could have positive effects on motivation and engagement for users completing their goals in a professional environment. As the results show that gamification could have beneficial effects this could indicate that it is a method worth looking more into for companies wanting to increase their users’ motivation and engagement. Faculty of Sci ence and Technol ogy, U ppsal a U niversity. Place of publication eg Uppsala/Visby. Supervisor: Tomas Johansson, Subjec t reader: Mikael Laaksoharju, Exami ner : Johannes Borgstr öm
Possible links between ozone and temperature profiles

With a multiple linear regression analysis ozone and temperature trends are determined for a cold and warm half-year cycle, based on concurrent ozone and temperature data recorded at various ozonesonde stations over the past decades. It is attempted to quantify the derived temperature trends, either in terms of radiative cooling caused by the trends in ozone and other greenhouse gases, or in terms of changes in the vertical advection regime. In the lower stratosphere, it is found that an increase in the ascent-rate of air over the observed period often explains the observed cooling and ozone depletion, whereas higher up in the stratosphere the temperature trends are often in agreement with radiative transfer calculations. With the ozone and temperature residuals, correlation profiles are constructed, as well as sensitivity curves which give the local air temperature response to local changes in ozone. These sensitivity curves are compared with radiative transfer calculations for the stratosphere.
Detection of soot particles in gas turbine engine combustion gases using nonintrusive FTIR spectroscopy

Fourier transform IR (FTIR) spectroscopy for making non- intrusive measurements of gas turbine exhaust gases and laser induced incandescence for measuring soot content are being evaluated in EU Brite EuRam project AEROJET. Soot concentrations in modern aero-engine exhausts are very low with mean particle sizes < 100 nm. The standard extractive filter paper soot measurement gives results expressed in terms of SAE smoke number, typically < 10 SAE for modern engines.
Land cover change and its relation with population dynamics in Burkina Faso, West Africa

In the tropics, conversion of woodland and forest into cropland and pasture has risen drastically during the last decade. Rapid population growth and poverty are believed to be the main factors of change in land use in these zones. Southern Burkina Faso experienced rapid population growth due to massive peasants' migration from the north and central regions of the Country, exacerbated by decreasing rainfall and arable land in the area of origin. This paper assessed the impact of such increased population on land use change in the attracting zones from 1986 to 2006. Satellite images were used to measure changes in land cover types over time and national population census data were used to examine the population dynamics over the same time. Results showed that the forest land was progressively converted to croplands at an annualized rate of 0·96 per cent, while the population density shifted from 17 inhabitants per km2 in 1986 to 30 inhabitants per km2 in 2006. Pearson correlation analysis revealed the positive role of population size and distribution in explaining land cover change. Policy initiatives that will lead to better environmental management are recommended. Copyright © 2010 John Wiley & Sons, Ltd.
Subglacial thermal balance permits ongoing grounding-line retreat along the Siple Coast of West Antarctica

Abstract Changes in the discharge of West Antarctic ice streams are of potential concern with respect to global sea level. The six relatively thin, fast-flowing Ross ice streams are of interest as low-slope end-members among Antarctic ice streams. Extensive research has demonstrated that these “rivers of ice” have a history of relatively high-frequency , asynchronous discharge variations with evolving lateral boundaries. Amidst this variability, a ∼1300 km grounding-line retreat has occurred since the Last Glacial Maximum. Numerical studies of Ice Stream D (Parizek and others, 2002) indicate that a proposed thermal-regulation mechanism (Clarke and Marshall, 1998; Hulbe and MacAyeal, 1999; Tulaczyk and others, 2000a, b), which could buffer the West Antarctic ice sheet against complete collapse, may be over-ridden by latent-heat transport within melt-water from beneath inland ice. Extending these studies to Ice Stream A, Whillans Ice Stream and Ice Stream C suggests that further grounding-line retreat contributing to sea-level rise is possible thermodynamically However, the efficiency of basal water distribution may be a constraint on the system. Because local thermal deficits promote basal freeze-on (especially on topographic highs), observed short-term variability is likely to persist.
A Marine Reservoir Correction Value (ΔR) for the Palauan Archipelago: Environmental and Oceanographic Considerations

ABSTRACT This paper investigates the marine reservoir effect (ΔR) around Palau with specific focus on environmental and oceanographic causes of variation. Two new ΔR values of known-age, pre-AD 1950 Scaridae sp. fish bone from the lagoon, are compared to extant marine shell values from the western branch of the North Pacific Gyre. This review indicates that a ΔR value of 75 ± 68 14C yrs for the ocean immediately surrounding Palau best fits the available evidence, while a value of −52 ± 22 14C yrs should be used for the southwest lagoon. Comparison of marine and charcoal samples from archaeological deposits on Ulong Island lend support to this regional open ocean marine reservoir value, but additional analysis is required to assess the stability of this value around the archipelago and over time. The analysis highlights that careful, informed selection of radiocarbon samples is essential to produce tight radiocarbon chronologies for Pacific archaeological sites.