20 research outputs found
Combining Green Energy Production with Hazardous Waste Recycling: Railway Sleepers as Support of Photovoltaic Systems
Constraints on the thickness and seismic properties of the lithosphere in an extensional setting (Nógrád-Gömör Volcanic Field, Northern Pannonian Basin)
TheNógrád-GömörVolcanic Field (NGVF) is one of the five mantle xenolith bearing
alkaline basalt locations in the Carpathian Pannonian Region. This allows us to constrain
the structure and properties (e.g. composition, current deformation state, seismic anisotropy,
electrical conductivity) of the upper mantle, including the lithosphere-asthenosphere boundary
(LAB) using not only geophysical, but also petrologic and geochemical methods. For
this pilot study, eight upper mantle xenoliths have been chosen from Bárna-Nagyk˝o, the
southernmost location of the NGVF. The aim of this study is estimating the average seismic
properties of the underlying mantle. Based on these estimations, the thickness of the
anisotropic layer causing the observed average SKS delay time in the area was modelled
considering five lineation and foliation end-member orientations. We conclude that a 142–
333km thick layer is required to explain the observed SKS anisotropy, assuming seismic
properties calculated by averaging the properties of the eight xenoliths. It is larger than the
thickness of the lithospheric mantle. Therefore, the majority of the delay time accumulates
in the sublithospheric mantle. However, it is still in question whether a single anisotropic
layer, represented by the studied xenoliths, is responsible for the observed SKS anisotropy,as it is assumed beneath the Bakony–Balaton Highland Volcanic Field (Kovács et al. 2012),
or the sublithospheric mantle has different layers. In addition, the depths of the Moho and
the LAB (25 ± 5, 65 ± 10 km, respectively) were estimated based on S receiver function
analyses of data from three nearby permanent seismological stations
The athlete’s heart Part I (Review)
Importance of the athlete’s heart has been arisen in the last decades.
Consequences of the sedentary way of life are the most threatening through the impairments of the cardiovascular system.
Endurance performance is mostly limited by the characteristics of the athlete’s heart.
Sudden death of the athletes is always associated with cardiac disorders.
Main characteristics of the athlete’s heart can be divided into morphologic, functional and regulatory ones.
The main morphologic characteristics are the physiologic left ventricular (LV) hypertrophy and a richer coronary capillary network.
The functional adaptation contains a better systolic and diastolic function, modified metabolism and electric characteristics. The most easily detected modification is the better LV diastolic function.
Adaptation of the cardiac regulation is manifested mostly by a lower heart rate (HR).
Summarizing: the athlete’s heart is an enlarged but otherwise normal heart characterized by a low heart rate, an increased pumping capacity, and a greater ability to deliver oxygen to skeletal muscle
Relationship between the heart rate and E/A ratio in athletic and non-athletic males
To clarify whether the higher E/A quotient of male athletes is a favourable change in the intrinsic relaxation
properties of the left ventricle.
Methods:
Peak early (E) and atrial blood flow velocities (A) were assessed by Doppler echocardiography at rest
in 1237 males (939 athletes) in Hungary. Data were collected between 1993–2009. Relationship between E/A and
resting heart rate (HR), was determined by linear regression analysis.
Results:
The E/A decreased with age, the rate of decrease was slower in the physically trained subjects, except in
children. In children, adolescent-young and young adult subjects E/A against HR equations of the athletic and non-
athletic groups were similar, differences between the means were only due to the differences of the HR. In the 31–44
yr old males, the intercepts of the athletes’ regression lines were higher. The oldest (>44 yr) active subjects showed
a significant regression while sedentary males did not.
Conclusions:
The HR-independent beneficial effect of regular physical training on the diastolic function manifests
itself at the older ages. The impact of resting HR should always be taken into consideration when assessing intergroup
differences in the E/A ratio, especially when studying the effect of exercise training upon cardiac function
Echocardiographic and spiroergometric data of elite Hungarian female water polo players
In the authors’ earlier study the relative aerobic power of Hungarian top-level male water polo players was found to be smaller than that of other top-level athletes, while their echocardiographic parameters proved to be the most characteristic of the athlete’s heart. In the present investigation echocardiographic and spiroergometric data of female top-level water polo players were compared to those of other female elite athletes and of healthy, non-athletic subjects. Relative aerobic power in the water polo players was lower than in endurance athletes. Mean resting heart rates were the slowest in the water polo players and endurance athletes. Morphologic indicators of the heart (body size related left ventricular wall thickness and muscle mass) were the highest in the water polo players, endurance and power athletes. In respect of diastolic functions (diastolic early and late peak transmitral flow velocities) no difference was seen between the respective groups.These results indicate that, similarly to the males, top-level water polo training is associated with the dimensional parameters of the heart rather than with relative aerobic power. For checking the physical condition of female water polo players spiroergometric tests seem to be less appropriate than swim-tests with heart rate recovery studies such as the ones used in the males
Interannual variability of grasslands’ carbon balance depends on soil type
Interannual variation of carbon fluxes of grasslands on sandy (5 years data) and heavy clay soils (4 years data) have been analysed. The sandy grassland was carbon sink in 3 (2004, 2005, 2006) out of the investigated 5 years. Its annual C-balance is precipitation limited, the relation seems strongly conservative, with r2
of 0.83. More than half of the net source activity fell to the summer droughts. The heavy clay grassland was net source of carbon in one year (2007) only with no whole year record from 2003, a drought and heat wave year. Dependence of the C-balance on precipitation was somewhat weaker (r2 =0.57) than in the sandy grassland. Length of growing period showed less variation here compared to the sandy grassland. Recovery of sink activity after rains was much slower for the heavy clay grassland than for the sandy grassland. The reason behind is that the amount of water required to reach optimal soil water content for plant functioning is several times larger for the mountain grassland. This fact and the low conductivity of the clay soil for water decrease the heavy clay grassland’s recovery potential after droughts. Owing to these soil characteristics, the clay grassland may be more vulnerable to droughts in terms of decreased C-assimilation and (soil) carbon losses under the predicted drier summers even if the annual precipitation sum was higher by 10.7% on average for the mountain compared to the sandy grassland. The annual precipitation sum is close to the threshold, below which the grasslands may turn into source of carbon. While in one hand this can be viewed as an example of ecosystem scale adaptation to available water, drought events also involve loss of soil carbon and a potential positive feedback between source activity and decreasing net primary production, on the other