scholarly journals Morphologische Untersuchungen im nordöstlichen Matmata-Vorland (nördliche Djeffara, Südtunesien)

1975 ◽  
Vol 26 (1) ◽  
pp. 218-240 ◽  
Author(s):  
Karl-Ulrich Brosche ◽  
Hans-Georg Molle
Keyword(s):  
Climatic Conditions ◽  
The Other ◽  
Early Holocene ◽  
Distribution Area ◽  
River Systems ◽  
14C Dating ◽  
Entire Area ◽  
Fine Sediments ◽  
River Bed ◽  
14C Age

Abstract. Geomorphological investigations into the sequence of formation phases in the area of the two river-systems Oued Termamane — Oued Zigzaou and Oued en Negueb — Oued El Hallouf — Oued Oum Es Zessar in N. Djeffara in S. Tunisia permit us to distinguish above the recent river-bed, apart from youngest, anthropogenically caused deposits, a "younger accumulation" composed of fine sediments, a "main accumulation" consisting for the most part of coarse pebbles and remainders of at least 2 older, higher-lying levels which cannot be reliably correlated. The "main accumulation" is found in the entire area of the aforementioned Oueds, the „younger accumulation" on the other hand only in their middle and lower courses. The latter is missing in the main distribution area of the Matmata silts (primarily wind-deposited, later fluviatile remodelled sediments), in the mountains and on their edges. On the strength of the 14C-dating of 2 charcoal specimens (Hv 5566 and Hv 5400) the deposits of the „younger accumulation" may be placed in the period between 9000 — 7000 B.P. The dating of a calccrust from the top of the "main accumulation" showed a 14C-age of 21385 ± 235 B.P. (Hv 5402). Even taking into account the considerable possibilities of error in this dating, a Würm age may be assumed for the "main accumulation". The silts of Matmata overlie the "main accumulation" and come into consideration as supplier of material for the sediments of the "younger accumulation", accordingly the age of the silts may be assumed to be Würm to Early Holocene. Climatic conditions more humid than those today are indicated by a fossilized "Kalkbraunerde" in the Matmata silts, the occurence of calccrusts and a transport of pebbles at the time of the "main accumulation" reaching considerably further into the Matmata foreland than the pebble-transport of the recent river-beds.

scholarly journals Palaeoenvironmental evolution from the early Holocene to the present of the Almenara marsh (western Mediterranean)

2019 ◽  
Vol 82 (4) ◽  
pp. 257 ◽  
Author(s):  
Ana M. Blázquez-Morilla ◽  
Ana Rodríguez-Pérez ◽  
Daniel Sanjuán-Lamata
Keyword(s):  
Western Mediterranean ◽  
Freshwater Marsh ◽  
Water Levels ◽  
Early Holocene ◽  
Agricultural Activity ◽  
14C Dating ◽  
Foraminiferal Assemblage ◽  
Entire Area ◽  
Middle Holocene ◽  
Benthic Foraminiferal Assemblage

The main aim of this study is to characterize the different stages in the palaeoenvironmental evolution of the Almenara marsh, Spain, from the early Holocene to the present day. This marsh is one of the most important in Castellón province. Five cores extracted from the marsh underwent sedimentological analysis, micropalaeontological study (foraminifera, ostracods and gastropods) and 14C dating. The results show that before the maximum transgression of the Mediterranean during the Marine Isotope Stage 1 (5500 cal yr. BP dating in the Almenara marsh), the area was occupied by a brackish marsh (prior to the 8.2 ka event). During the middle Holocene, the regional sea level rise and later stability caused an oligohaline/freshwater marsh with fluctuating water levels to form. This marsh occupied the entire area of today’s Almenara marsh at least between 7570 and 2780 cal yr BP. The results may indicate a phase of greater contribution of groundwater inputs (and rainfall/riverine discharge) during the middle Holocene as a response to a climatic phase characterized by higher humidity. Today, the marsh is filled with sediments from natural and anthropic processes related to the agricultural activity carried out throughout the area (except for the central part, which has been reclaimed as wetland). The water of the present-day marsh (like that prior to 8.2 ka event) is brackish, as is indicated by the benthic foraminiferal assemblage; this contrasts with the earlier oligohaline/freshwater marsh determined in the survey cores during the middle Holocene until the time of the Iberian culture.

Use of Ornamental Trees in Dating of Abandoned Cemeteries on the Example of Thuja Occidentalis and Thuja Orientalis

2012 ◽  
Vol 1 (1) ◽  
pp. 45-50
Author(s):  
Magdalena Opała ◽  
Leszek Majgier
Keyword(s):  
Climatic Conditions ◽  
The Other ◽  
Lake District ◽  
Thuja Occidentalis ◽  
North Eastern ◽  
The 1960S ◽  
Thuja Orientalis ◽  
Ornamental Trees ◽  
Common Tree ◽  
Local Habitat

Abstract Due to the lack of maintenance, abandoned cemeteries are often incorporated into the landscape. In many cases the information about the age of the cemetery is unavailable. To find out the approximate time of the formation of the cemetery the information recorded in the annual tree and shrub rings can be used. One of the most common tree species, planted for ornamental and symbolic purposes on the cemeteries, are Thuja orientalis and Thuja occidentalis. Alien to the Polish flora, these species adapted well to the local habitat and climatic conditions. The paper presents an attempt to apply dendrochronological dating to determine the age of the abandoned cemeteries in the region of the Great Masurian Lakes, part of the Masurian Lake District (north-eastern Poland). The study included five abandoned cemeteries. In total, 15 cores were taken from the trees. After applying the standard dendrochronological method, local chronologies for the studied species were established. The research indicated that the oldest found specimens - over 70 yrs old - are Thuja occidentalis individuals growing at the Słabowo cemetery. At the other sites the specimens of both Thuja species date back to the 1960s and early 1970s. Compared to the historical information regarding the age and origin of the studied objects, thujas growing there are much younger than the age of the cemeteries foundation. The presented method proved to be very helpful in understanding the time of Thuja occidentalis and Thuja orientalis introduction at the investigated cemeteries.

scholarly journals When Density Matters: The Spatial Balance between Early and Latewood

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 818
Author(s):  
Maria Royo-Navascues ◽  
Edurne Martinez del Castillo ◽  
Roberto Serrano-Notivoli ◽  
Ernesto Tejedor ◽  
Klemen Novak ◽  
...  
Keyword(s):  
Species Distribution ◽  
Pinus Halepensis ◽  
Environmental Gradients ◽  
Temporal Variations ◽  
Western Mediterranean ◽  
Climatic Conditions ◽  
Growth Patterns ◽  
Distribution Area ◽  
Mediterranean Forests ◽  
Climatic Influence

Understanding the influence of the current climate on the distribution, composition, and carbon storage capacity of Mediterranean tree species is key to determining future pathways under a warmer and drier climate scenario. Here, we evaluated the influence of biotic and environmental factors on earlywood (EW) and latewood (LW) growth in Aleppo pine (Pinus halepensis Mill.). Our investigation was based on a dense dendrochronological network (71 sites), which covered the entire distribution area of the species in the Iberian Peninsula (around 119.652 km2), and a high-resolution climate dataset of the Western Mediterranean area. We used generalized linear-mixed models to determine the spatial and temporal variations of EW and LW across the species distribution. Our results showed an intense but differentiated climatic influence on both EW and LW growth components. The climatic influence explained significant variations across the environmental gradients in the study area, which suggested an important adaptation through phenotypic plasticity and local adaptation to varying climatic conditions. In addition, we detected a clear spatial trade-off between efficiency and safety strategy in the growth patterns across the species distribution. Additionally, in more productive areas, the trees presented a higher proportion of EW (more efficient to water transport), while, in more xeric conditions, the LW proportion increased (more safety to avoid embolisms), implying an adaptation to more frequent drought episodes and a higher capacity of carbon depletion. We therefore concluded that Mediterranean forests adapted to dryer conditions might be more efficient as carbon reservoirs than forests growing in wetter areas. Finally, we advocated for the need to consider wood density (EW/LW proportion) when modeling current and future forest carbon sequestrations.

Treatment of frostbite in an open way (without dressings)

1937 ◽  
Vol 33 (1) ◽  
pp. 84-86
Author(s):  
V. A. Petrovykh
Keyword(s):  
Recovery Period ◽  
Climatic Conditions ◽  
The Other ◽  
Critical Approach ◽  
Tatar Strait ◽  
Other Hand ◽  
Number Of Patients ◽  
The One ◽  
Apparent Similarity ◽  
Methods Of Treatment

The harsh climatic conditions of the coast of the Tatar Strait make explainable the large number of patients with frostbite who passed under our supervision during the winter of 1935-36 and amounted to 2.8% (26 people) of the total contingent of inpatients. The variety of recommended methods for treating frostbite, on the one hand, and the relatively long recovery period for all of them, on the other hand, made us take a critical approach to the proposed methods of treatment. All currently existing methods are reduced to the treatment of frostbite areas with bandages; and on the locus morbi apply indifferent or slightly disinfecting ointments, or a similar property of a powder, or wipes moistened with slightly disinfecting solutions, for example, Sol. kalii hyperm. 1: 1000. The apparent similarity of the external manifestations of frostbite and burns inspired us with the idea of ​​conducting frostbite therapy in an "open way", which has long occupied a well-deserved place in the treatment of burns.

Climate forcing of volcano lateral collapse: evidence from Mount Etna, Sicily

2010 ◽  
Vol 368 (1919) ◽  
pp. 2559-2577 ◽  
Author(s):  
K. R. Deeming ◽  
B. McGuire ◽  
P. Harrop
Keyword(s):  
Slope Failure ◽  
Climatic Conditions ◽  
Early Holocene ◽  
Mount Etna ◽  
Watershed Development ◽  
Eastern Flank ◽  
Consequent Reduction ◽  
Water Saturated ◽  
Excess Pore Pressures ◽  
Exposure Ages

In this study, we present evidence for early Holocene climatic conditions providing circumstances favourable to major lateral collapse at Mount Etna, Sicily. The volcano’s most notable topographic feature is the Valle del Bove, a 5×8 km cliff-bounded amphitheatre excavated from the eastern flank of the volcano. Its origin due to prehistoric lateral collapse is corroborated by stürtzstrom deposits adjacent to the amphitheatre’s downslope outlet, but the age, nature and cause of amphitheatre excavation remain matters for debate. Cosmogenic 3 He exposure ages determined for eroded surfaces within an abandoned watershed flanking the Valle del Bove support channel abandonment ca 7.5 ka BP, as a consequence of its excavation in a catastrophic collapse event. Watershed development was largely dictated by pluvial conditions during the early Holocene, which are also implicated in slope failure. A viable trigger is magma emplacement into rift zones in the eastern flank of a water-saturated edifice, leading to the development of excess pore pressures, consequent reduction in sliding resistance, detachment and collapse. Such a mechanism is presented as one potential driver of future lateral collapse in volcanic landscapes forecast to experience increased precipitation or melting of ice cover as a consequence of anthropogenic warming.

scholarly journals ARDUINO based accident prevention and auto intimation system

2020 ◽  
Vol 17 (3) ◽  
pp. 1275
Author(s):  
Palanisamy R ◽  
PLS Sai Kumar ◽  
Mekala Paavan Kiran ◽  
Ashutosh Mahto ◽  
Md. Irfan ◽  
...  
Keyword(s):  
Collision Avoidance ◽  
Black Box ◽  
Climatic Conditions ◽  
The Other ◽  
Motor Vehicles ◽  
The Road ◽  
Ir Sensors ◽  
Collision Mitigation ◽  
Collision Avoidance System ◽  
On The Road

<p>Often modern cars have a collision avoidance system built into them known as Pre-Crash System, or Collision Mitigation System in order to reduce the collision. But majority of vehicles on the road, especially heavy motor vehicles lack in such a system. In this paper, the implementation of the Collision Avoidance System is to reduce the risks of collisions at the hairpin bend on a Hilly track, Ghats, or other Zero visibility turns. The proposed system contains a set of IR sensors, LEDs, etc. It uses four IR sensors, which are placed on either side of the hairpin bend. The sensors are mutually exclusive and are connected to LEDs through wires. Based on the output of sensors, the LEDs will glow and start alerting the other vehicle approaching from the other end, Hence the drivers will decrease their speeds which would help in preventing collision. The LEDs will help the drivers in detecting the position of  the vehicles on either side of the bend. During climatic conditions like fog, snow, etc, the visibility of the drivers would decrease due to which they will not be able to see the LEDs, Hence, a collision may take place. To bring help as soon as possible to the injured, we have also made a proposed system which would alert the nearby hospitals that an accident has taken place. We have used Arduino UNO, GSM sim module and these will be kept inside a black box which will be inside the, car safe from breakage during the accident.<strong></strong></p>

Late Pleistocene and early Holocene rivers and wetlands in the Bonneville basin of western North America

2003 ◽  
Vol 60 (2) ◽  
pp. 200-210 ◽  
Author(s):  
Charles G. Oviatt ◽  
David B. Madsen ◽  
Dave N. Schmitt
Keyword(s):  
Great Basin ◽  
Late Pleistocene ◽  
Theoretical Models ◽  
Coarse Sand ◽  
Early Holocene ◽  
River Channels ◽  
Human Occupation ◽  
Lake Bonneville ◽  
River Bed ◽  
Bonneville Basin

AbstractField investigations at Dugway Proving Ground in western Utah have produced new data on the chronology and human occupation of late Pleistocene and early Holocene lakes, rivers, and wetlands in the Lake Bonneville basin. We have classified paleo-river channels of these ages as “gravel channels” and “sand channels.” Gravel channels are straight to curved, digitate, and have abrupt bulbous ends. They are composed of fine gravel and coarse sand, and are topographically inverted (i.e., they stand higher than the surrounding mudflats). Sand channels are younger and sand filled, with well-developed meander-scroll morphology that is truncated by deflated mudflat surfaces. Gravel channels were formed by a river that originated as overflow from the Sevier basin along the Old River Bed during the late regressive phases of Lake Bonneville (after 12,500 and prior to 11,000 14C yr B.P.). Dated samples from sand channels and associated fluvial overbank and wetland deposits range in age from 11,000 to 8800 14C yr B.P., and are probably related to continued Sevier-basin overflow and to groundwater discharge. Paleoarchaic foragers occupied numerous sites on gravel-channel landforms and adjacent to sand channels in the extensive early Holocene wetland habitats. Reworking of tools and limited toolstone diversity is consistent with theoretical models suggesting Paleoarchaic foragers in the Old River Bed delta were less mobile than elsewhere in the Great Basin.

Study on the interference of pier on the channel bed

2021 ◽  
pp. 278-284
Author(s):  
Atul Kumar Rahul ◽  
Akash Priyadarshee ◽  
Prabhat Kumar Singh ◽  
Shyam Bihari Dwivedi
Keyword(s):  
Laboratory Tests ◽  
The Other ◽  
Straight Channel ◽  
Sand Mining ◽  
Continuous Processes ◽  
River Bed ◽  
Natural Flow ◽  
Scouring Process ◽  
Study Laboratory ◽  
The Impact

Scoring and sedimentation are two continuous processes which take place in river bed. These two phenomena have significant impact over the overall behavior of river. Scoring and sedimentation process get affected due the construction of structures like Bridges. Piers of bridge alter the natural flow of rivers. Due to this scouring process increases near to the pier. The scouring process gets affected due to the other activities like sand mining or filling. Also any obstruction like some construction can also affect the scouring. In this study laboratory tests were conducted to understand the nature of scouring near to the pier. For this purpose, model test were conducted in a straight channel with a model concrete pier. The impact of the obstruction in flow, mining of sand and filling of the sand is investigated through this investigation. The finding of this study can be utilized in understanding and development of techniques of controlling scouring near the pier

Probabilistic Approach to the Assessment of the Depth of Soil Freezing

2016 ◽  
Author(s):  
Jerzy Antoni Żurański ◽  
Andrzej Sobolewski
Keyword(s):  
Soil Structure ◽  
Maximum Likelihood Method ◽  
Probabilistic Method ◽  
Probabilistic Approach ◽  
Climatic Conditions ◽  
The Other ◽  
Soil Freezing ◽  
Likelihood Method ◽  
Freezing Depth ◽  
Characteristic Values

The paper deals with the probabilistic method of the assessment of the depth of soil freezing. Annual (winter) maxima of the position of the zero centigrade temperature measured in the soil were approximated by Gumbel probability distribution. Its parameters were estimated using maximum likelihood method. Results received on the base of data from 2 meteorological stations and 30 years of observations, called as characteristic values of 50-year return period, refelect the influence of the climatic conditions on the freezing depth. On the other hand the soil structure and its conditions also play an important role in freezing. Nowadays they may be taken into account using correction coefficients. It is concluded that this methods is more precise than a method using so called air freezing index. Received results are not the same as given in the old Polish Standard. New analysis is currently being done.

scholarly journals Durability of traditional clamped joints in the vapour barrier layer: experimental and numerical analysis

2019 ◽  
Vol 46 (11) ◽  
pp. 996-1000 ◽  
Author(s):  
Lars Gullbrekken ◽  
Klodian Gradeci ◽  
Øyvind Norvik ◽  
Petra Rüther ◽  
Stig Geving
Keyword(s):  
Climate Change ◽  
Energy Consumption ◽  
Climatic Conditions ◽  
The Other ◽  
Use Of Self ◽  
Air Leakage ◽  
Building Envelopes ◽  
Frame Buildings ◽  
Wood Frame ◽  
Numerical Estimations

Clamped joints of wood frame buildings are a traditional way in Norway to attain airtight joints for the air and vapour barrier. There are numerous defects registered in the SINTEF Building Defects Archive related to air leakage through the vapour barrier, on one hand, and stricter requirements for reduced energy consumption, on the other hand, question today’s efficacy of these type of joints. This study investigates the durability of clamped joints by studying how the airtightness is affected by several drying and wetting cycles. Experimental work is carried out to measure air leakage rates, which in turn, are used to evaluate their impact on the airtightness of two different constructions by numerical estimations. Results show that the air leakage rates are increased significantly due to transient climatic conditions. Clamped joints may no longer provide airtight building envelopes given the stricter requirements for energy consumption and implications of climate change. A more promising and robust alternative is the use of self-adhesive tapes.

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