Miracle-dz/UniFAR-FTUs huggingface dataset:
THREE-DIMENSIONAL SLOPE STABILITY : END EFFECTS

ABSTRACT Common procedures for slope stability analysis are essentially two dimensional (plane strain) despite the fact that observed failure mechanisms in the field possess clear three dimensional characteristics. A review of the few existing analysis procedures which are applicable to three dimensional failure mechanisms revealed some serious shortcomings such as failure to degenerate to known solutions when boundary cases are considered or dependence on constants which are extremely difficult to estimate. Presented is a three dimensional failure mechanism which is obtained through a variational limiting equilibrium approach without arbitrary assumptions. This mechanism consists of the shape of the potential slip surface and the potential direction of slip at each point on this surface. The present work deals with homogeneous and symmetrical slopes which are constrained in the 3rd direction; e. g. a dam in a narrow valley or a trench of finite length. The analysis results are presented in a form of stability charts relating the geometrical parameters of the slope, soil properties, and the 3-D factor of safety. Qualitatively, the results show that 3-D end effects are most pronounced in slopes made of highly cohesive soil. For cohesionless soil, no end effects exist since the critical slip surface then coincides with the surface of the slope.
The Dynamics of Large-Scale, Wind-Driven Variations in the Antarctic Circumpolar Current

A nonlinear model is devloped and analytical results obtained to discuss the response of the Antarctic Circumpolar Current to wind forcing over a wide range of frequencies. The main results are as follows: (i) The nonlinear equations of motion can be conveniently separated into one ''baroclinic'' and one ''barotropic'' mode. (ii) For forcing with period T equal to less than a few years, wind-driven fluctuations in the Antarctic Circumpolar Current are barotropic and governed by the linearized Laplace tidal equations. Theory suggests that fluctuations in the transport should lag, and be most strongly correlated with, the circumpolar-averaged wind stress. These theoretical results are consistent with recent measurements made in Drake Passage. An interested untested theoretical prediction is that the sea level fluctuations measured at the southern side of Drake-Passage with T between one month and a few years should be coherent at zero lag with sea level fluctuations at the same latitude around the earth. (iii) For longer period forcing, baroclinic fluctuations are important. The baroclinic pressure, current and associated density variations all decrease exponentially with depth. Exponential depth decay of these baroclinic fields is in fact observed, the decay scale being about 1 km. (iv) The theory indicates thatmore » significant large-scale, wind-driven fluctuations in the strength of the baroclinic Antarctic Circumpolar Current can only occur at frequencies with periodicity > or approx. =70 years. Climatic changes associated with such variability must therefore consist of oscillations of similar or longer period. This is consistent with limited observations which suggest that wind and sea-surface temperature in the region of the Antarctic Circumpolar Current have fluctuated through one ''cycle'' over the last 100 years. « less
Interannual variability of air-sea fluxes of carbon dioxide and oxygen

Columbia University / Lamont Doherty Earth Observatory New York NY / Palisades NY 2017 to present Professor, Earth and Environmental Sciences The focus of my research program is the ocean carbon cycle. I am particularly interested in physical drivers of variability in the carbon cycle, distinguishing this variability from anthropogenic trends, and links between primary production and carbon cycling.
Hysteresis between coral reef calcification and the seawater aragonite saturation state

Some predictions of how ocean acidification (OA) will affect coral reefs assume a linear functional relationship between the ambient seawater aragonite saturation state (Ωa) and net ecosystem calcification (NEC). We quantified NEC in a healthy coral reef lagoon in the Great Barrier Reef during different times of the day. Our observations revealed a diel hysteresis pattern in the NEC versus Ωa relationship, with peak NEC rates occurring before the Ωa peak and relatively steady nighttime NEC in spite of variable Ωa. Net ecosystem production had stronger correlations with NEC than light, temperature, nutrients, pH, and Ωa. The observed hysteresis may represent an overlooked challenge for predicting the effects of OA on coral reefs. If widespread, the hysteresis could prevent the use of a linear extrapolation to determine critical Ωa threshold levels required to shift coral reefs from a net calcifying to a net dissolving state.
Smoke consequences of new wildfire regimes driven by climate change

Smoke from wildfires has adverse biological and social consequences, and various lines of evidence suggest that smoke from wildfires in the future may be more intense and widespread, demanding that methods be developed to address its effects on people, ecosystems, and the atmosphere. In this paper, we present the essential ingredients of a modeling system for projecting smoke consequences in a rapidly warming climate that is expected to change wildfire regimes significantly. We describe each component of the system, offer suggestions for the elements of a modeling agenda, and provide some general guidelines for making choices among potential components. We address a prospective audience of researchers whom we expect to be fluent already in building some or many of these components, so we neither prescribe nor advocate particular models or software. Instead, our intent is to highlight fruitful ways of thinking about the task as a whole and its components, while providing substantial, if not exhaustive, documentation from the primary literature as reference. This paper provides a guide to the complexities of smoke modeling under climate change, and a research agenda for developing a modeling system that is equal to the task while being feasible with current resources.
Sea surface Warming and its Implications for Harmful Algal Blooms off Oman

The analysis of the sea surface temperature (SST) data for the period from 1961 to 2010, showed the SST regime changes off Oman on different temporal scales. A rapid warming phase is conspicuous in the SST off Muscat and off Masirah along Oman after 1984. The shifts in the SST occurred several times on shorter time scales prior to 1984 but a notable shift in the SST occurred after 1984 when the mean annual SST increased by 0.53℃ off Masirah and by 0.32℃ off Muscat. The amplitude and period of heating/cooling are smaller and shorter off Muscat compared to Masirah with increasing summer warming and decreasing winter cooling. The multivariate ENSO index (MEI) and the annual mean SST at the study locations showed better correlation (R 2 =0.3) with April-May MEI compared to the other months. The highs and lows of SST at both the locations responded with stronger El Nino and La Nina events respectively. The frequency of harmful algal bloom (HAB) events off Oman closely followed the warming and cooling patterns of the sea surface. The frequency of HAB events increased with increasing SST during present decade (2001~2010). The increase in toxic or potentially harmful HAB events may be the consequence of upper ocean stratification forced by increasing SST.
Unification and Planning of Urban Public Spaces With Bioclimatic Conditions. Case Study Drama, Greece

The green spaces in the urban environment facilitate the movement of air masses that act as air refreshment in the wider region. The unification of urban open spaces and their enrichment with vegetation affect the micro-climate positively and act as a decisive factor for the increasing of urban thermal comfort, via the shading and the phenomenon of evapotranspiration. The planning of urban public spaces can support a habitat network encouraging the connectivity of the man-made environments with the surrounding natural ecosystems. The present paper aims to promote the unification of urban open spaces, with bioclimatic criteria by emphasizing the role of vegetation aiming the enhancement of living conditions in settlements. In particular is analysed the data collection like the proportion of building height with road width H/W, the road orientation and the solar access, the paving materials, the existent vegetation and concludes to an urban unification in a central part of Drama city in Northern Greece, by creating walkways and green corridors. The issue of solar access outdoors has been briefly discussed as an additional criterion in landscape designing the street. Design recommendations are also outlined for designing comfortable urban spaces.
A Bayesian coregionalization approach for multivariate pollutant data

[1] Spatial data collection increasingly turns to vector valued measurements at spatial locations. An example is the observation of pollutant measurements. Typically, several different pollutants are observed at the same sampled location, referred to as a monitoring station or gauged site. Usually, interest lies in the modeling of the joint process for the levels of the different pollutants and in the prediction of pollutant levels at ungauged sites. In this case, it is important to take into account not only the spatial correlation but also the correlation among the different variables at each gauged site. Since, conceptually, there is a potentially observable measurement vector at every location in the study region, a multivariate spatial process becomes a natural modeling choice. In using a Gaussian process, the main challenge is the specification of a valid and flexible cross-covariance function. This paper proposes a rich class of covariance functions developed through the so-called linear coregionalization model [see, e.g., Wackernagel, 1998] for multivariate spatial observations. Following the ideas in the work of, for example, Royle and Berliner [1999], we can reparameterize a multivariate spatial model using suitable univariate conditional spatial processes, facilitating the computation. We provide explicit details, including the computation of the range associated with the different component processes. As an example, we fit our model to a particular day average of CO, NO, and NO2 for a set of monitoring stations in California, USA.
Feathers and ‘feather‐like’ integumentary structures in Liaoning birds and dinosaurs

We provide an overview of the known feather and other ‘feather‐like’ integumentary structure types known to‐date in the birds and dinosaurs from the Cretaceous rocks of Liaoning, NE China. These feather‐types are classified and compared with similar structures seen in Mesozoic and extant birds. We consider that integumentary feathers and ‘feather‐like’ structures fall within two major structural categories (‘shafted’ and ‘non‐shafted’). Comments are also made on the possible aerodynamic or insulating function of leg and tail feathers in Mesozoic birds and theropods. Copyright © 2006 John Wiley & Sons, Ltd.
Precipitation of iron silicate nanoparticles in early Precambrian oceans marks Earth's first iron age

The early ocean was characterized by anoxic, iron-rich (ferruginous) conditions before the rise of atmospheric oxygen ∼2.45 b.y. ago. A proxy for ferruginous conditions in the ancient ocean is the deposition of banded iron formations (BIFs), which are iron- and silica-rich chemical sediments whose constituents were largely derived from seawater. Although experiments simulating ancient ocean chemistry support the rapid growth of iron-silicate phases, the main iron precipitates are hypothesized to have been ferric oxyhydroxides. The paradox between the prevailing reducing conditions and the deposition of oxidized iron phases is explained by biologically mediated oxidation in the water column. New high-resolution microscopy of BIFs and shales throughout the 2.63–2.45 b.y. old Hamersley Group, Australia, reveals the presence of vast quantities of nanometer-sized iron-silicate particles in laminated chert. The nanoparticles are finely disseminated in early diagenetic chert and locally define sedimentary lamination, indicating that they represent relicts of the original sediments. By inference from experimental studies simulating the composition of the early Precambrian ocean, we suggest that the nanoparticles precipitated from anoxic seawater enriched in silica and dissolved iron, and were silicified upon deposition. The prevalence of iron-silicate nanoparticles implies that they were pervasive background precipitates in ferruginous, silica-enriched oceans, forming the primary sediments of BIFs during periods of enhanced submarine mafic volcanism. Our results imply that silicate precipitation was a major sink of seawater iron and silica before the Great Oxidation Event and, because of the reactivity of nanoparticle surfaces, may also have influenced the transport and geochemical cycling of trace metals and nutrients. Our hypothesis that the basic building blocks of BIFs were predominantly iron-silicate muds rather than iron oxides and/or hydroxides may lead to new insights into seawater chemistry on the early Earth and the role of biology in the deposition of BIFs.
Distribution of Some Elements in Veronica scutellata L. from Bolu, Turkey: Soil-Plant Interactions

Veronica scutellata L. occurs in moist and wet habitats, such as ponds, marshes and other wetlands. This study was conducted on this species to examine its mineral element uptake status in terms of interactions between soil and plant. Experimental materials were taken from the Southern coast of Black Sea at coordinates 40o36'N and 31o16'E at an altitude of 1400 m above sea level from Bolu - Turkey; using standard methods and plant (root, stem and leaf parts) and soil mineral element measurements (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, Ni and Zn) were done. During the study, ICP-OES was employed for the measurement of mineral elements. It was observed that considerable amounts of B, Ca, K, Mg, Mn, Na and Zn are accumulated by the plant. ABSTRAK Veronica scutellata L. wujud di habitat lembab dan basah seperti kolam, rawa dan tanah bencah lain. Kajian dijalankan ke atas spesies ini untuk meneliti status pengambilan unsur mineral daripada segi saling tindakan antara tanih dan tumbuhan. Bahan percubaan telah diambil dari Pantai Timur Laut Hitam pada koordinat 40o36'U dan 31o16'T pada altitud 1400 m atas paras laut dari Bolu, Turki dengan menggunakan kaedah piawai dan tumbuhan (bahagian akar, batang dan daun) dan pengukuran unsur mineral tanih (Al, B, Ca, Cu, Fe, K, Mg, Mn, Na, Ni dan Zn) telah dilakukan. Semasa kajian, ICP-OES telah digunakan bagi pengukuran unsur mineral. Telah diperhatikan bahawa sejumlah amaun B, Ca, K, Mg, Mn, Na dan Zn telah terkumpul oleh tumbuhan.
The three‐dimensional solar wind around solar maximum

Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post‐maximum phase of the solar cycle. A mid‐sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from ∼70°N down to ∼30°N. We find that the speed maxima in the high‐speed streams follow the same slow drop in speed with decreasing latitude observed in the large polar coronal holes around solar minimum. These results suggest a solar wind acceleration effect that is related to heliolatitude or solar rotation. We also find that the solar wind dynamic pressure is significantly lower in the post‐maximum phase of this solar cycle than during the previous one, indicating that while the heliosphere is larger than near solar minimum, it should be smaller than during or after the previous maximum.
On the Problem of the Relation Between Structure and Function in the Brain From a Contemporary Viewpoint (Continued)*

In the first half of the present paper, which appeared in vol. 3, issue 4 issue of Motor Control, the authors elaborated on Bernstein's (193511967) idea of the ambiguity of the relationship between the central command and the peripheral effect. The authors presented maybe the strongest statement so far: It is because the means are variant that the results can be invariant. As in Bernstein's 1935 paper, this was taken as evidence that there is no one-to-one relationship between structure and function in the brain. The authors discussed the history of localization theories, pointing out that neither strong localizationism nor strong antilocalizationism (as in Lashley's equipotentiality) would help understand the relation between brain structure and function. In order to understand the nature of a "brain center" for a function, the authors argued, one has to understand the concept of "function" itself. The development of "function7' does not imply that the organism learns to (re)act in a stereotyped fashion, but that a control matrix is established, with non-single-valued relationships, allowing the organism to (re)act differently every time, in accordance with the need and actual situation. At the end of the first part of the paper, the authors emphasized the importance of a new basic logic of neurophysiology. In that sense, there are certain parallels between neurophysiology in the 60s (and also today, the present editors would add) and physics around the turn of the century, when Maxwell, Boltzmann, Planck, and others, created a completely new framework for theoretical physics.
Contribution of Viscous Forces to Avalanche Dynamics

Mini-avalanche systems were constructed both in a low-temperature laboratory and in a snowfield, and the behaviour of the flowing snow was observed in each case. Velocity profiles for the individual snow particles were determined and these implied that a viscous force, which has been neglected in most previous numerical simulations of snow-avalanche motion, needs to be taken into account for many avalanches. Kinematic viscosity coefficients for the fluidized snow were also measured using a modified Stormer-type viscometer. Substituting the dry-friction value and the kinematic viscosity coefficient for fluidized snow into the equation for avalanche motion, numerical simulation of natural events was achieved for the Shiai-dani region. Taking viscous resistance factors into account led to the conclusion that the magnitude of turbulent resistance of snow in avalanche systems is probably much smaller than that represented by the values previously in use.
Changes in stream water quality due to logging of the boreal forest in the Montmorency Forest, Québec

Summer stream water quality was monitored before and following the logging of 50% of the boreal forest within three small watersheds (<50 ha) nested in the ‘Ruisseau des Eaux‐Volées’ Experimental Watershed, Montmorency Forest (Québec, Canada). Logging was conducted in winter, on snow cover according to recommended best management practices (BMPs) to minimize soil disturbance and protect advance growth. A 20‐m forest buffer was maintained along perennial streams. In watershed 7·2, cut‐blocks were located near the stream network and logging was partially allowed within the riparian buffer zone. In watersheds 7·5 and 7·7, logging occurred farther away from the stream network. Observations were also made for watershed 7·3 that collected the runoff from watersheds 7·2 and 7·5, and watershed 7·6, the uproad portion of watershed 7·7. The control watershed 0·2 was contiguous to the impacted watersheds and remained undisturbed. Following clearcutting, changes in summer daily maximum and minimum stream temperatures remained within ± 1 °C while changes in diurnal variation did not decrease by more than 0·5 °C. Concentrations of NO3− greatly increased by up to 6000% and concentrations of K+ increased by up to 300% during the second summer after logging. Smaller increases were observed for Fetotal (up to 71%), specific conductance (up to 26%), and Mg2+ (up to 19%). Post‐logging pH decreased slightly by no more than 7% while PO43− concentration remained relatively constant. Suspended sediment concentrations appeared to increase during post‐logging, but there was not enough pre‐logging data to statistically confirm this result. Logging of moderate intensity and respecting established BMPs may account for the limited changes of water quality parameters and the low exceedances of the criteria for the protection of aquatic life. The proximity of the cutover to the stream network and logging within the riparian zone did not appear to affect water quality. Copyright © 2008 John Wiley & Sons, Ltd.
The potential impact of long-term copper fungicide usage on soil microbial biomass and microbial activity in an avocado orchard

The impact of copper-based fungicides on soil microbial function in an avocado orchard was assessed. Copper (Cu) residues (280 and 340 mg/kg, respectively) in surface soils (0-2 cm) of an established avocado orchard were shown to be significantly (n = 6, P ≤ 0.05) greater than a nearby reference site under natural vegetation (13 mg/kg). The bioavailable fraction of Cu in these soils was also shown to be significantly greater (2.15 and 1.29 mg/kg, c. pCu2+ 8.64) than in the reference site (0.71 mg/kg, c. pCu2+ 9.2), as measured by ion-selective electrode in CaCl2 extraction. Similar trends were observed for the 2-10 cm soil profile. Data suggest that the Cu residues are responsible for significant reductions in biomass carbon (Cmic) even though the orchard soils had similar or elevated levels of total organic carbon (Corg). The Cmic : Corg ratio was significantly lower in all of the Cu contaminated soils, and a significant correlation was observed between CaCl2-extractable Cu in the surface soils and Cmic (n = 16, r2 = 0.68, P b 0.01). Soil respiration in surface soils from the orchard were elevated (6.04 and 5.57 mg CO2-C/kg.day) compared with the reference soil (3.04 mg CO2-C/kg.day), and the metabolic quotient (qCO2) was also significantly greater.
Late Quaternary Paleoclimate in the Eastern Mediterranean Region from Stable Isotope Analysis of Speleothems at Soreq Cave, Israel

The eastern Mediterranean continental paleoclimate during the past 25,000 years was determined by a high-resolution petrographic, stable isotopic, and age study of speleothems from Soreq Cave, Israel. δ18O–δ13C trends indicate that all speleothems older than 7000 yr formed under conditions that differ from those of today. The period from 25,000 to 17,000 yr B.P. was characterized by the highest δ18O and δ13C values, which indicate deposition at temperatures of 12°–16°C, annual rainfall of 300–450 mm, and vegetation typical of a mixed C3–C4type. From 17,000 to 10,000 yr B.P. (deglaciation in northern Europe) δ18O values dropped progressively, correlative with warming (2°–3°C) and a gradual increase in precipitation. A simultaneous decrease in δ13C gives a range expected for C3-type vegetation. This period also shows significant δ18O and δ13C “spikes” which are correlatable with global events (e.g., Heinrich events and the Younger Dryas Stade). The speleothems that grew between 10,000 and 7000 yr B.P. have a unique petrography showing irregular thin laminae of various colors and much detritus. They have the lowest δ18O (corresponding to ∼1000 mm rain) coupled with the highest δ13C (caused by flooding events which stripped the soil cover). From 7000 to 1000 yr B.P. conditions became closer to those of today. This study demonstrates that global events which were recognized in Northern Europe and North Africa are also evident in the eastern Mediterranean and are reflected principally by large changes in the rainfall rate.