scholarly journals Welche Zukunft für den Bergwald und die Berglandwirtschaft in der Schweiz?: Fallstudien Gündlischwand und Grindelwald im Berner Oberland | What future for mountain forests and mountain forest management in Switzerland? Case studies in Gündlischwand and Grindelwald in the Bernese Oberland

2004 ◽  
Vol 155 (11) ◽  
pp. 492-500
Author(s):  
Annemarie Ruef ◽  
Michael Stettler
Keyword(s):  
Mountain Forest ◽  
Mountain Forests ◽  
Central Importance ◽  
The Face ◽  
Agricultural Use ◽  
Regional Landscape ◽  
Traditional Structures ◽  
Tourist Region ◽  
The Given ◽  
New Strategies

In the popular tourist region of Lütschinental there is much debate on the areas of shrubland, which in former times had been put to agricultural use, and the overaging of the forests. Managers' underuse of forest and land has a number of reasons:new challenges at political levels, the economic situation in the agrarian and wood markets, as well as the situation with regard to property laws. The actors involved, however, do not stand hopelessly in the face of shrubland and overaging forests. Concepts offering solutions exist and can be implemented within the given room for manoeuvring. The certification of forests or regional landscape developments, for example,offer promising approaches. On the other hand, the preservation of traditional structures, such as the mountain teams for the management of forest and land, is of central importance. The future of the Lütschinental will therefore need to include both old and new strategies.

Change of the redox potential in the profile of light grey forest surface-gleyed soil under different anthropogenic

2018 ◽  
Vol 2 (95) ◽  
pp. 26-29
Author(s):  
O.S. Gavrishko ◽  
Yu.M. Olifir ◽  
T.V. Partyka
Keyword(s):  
Redox Potential ◽  
Mineral Fertilizer ◽  
Fertilizer Application ◽  
Soil Tillage ◽  
Mineral Fertilizers ◽  
Gleyed Soil ◽  
Agricultural Use ◽  
Fertilizer System ◽  
And Control ◽  
The Given

The results of studies of the change in redox potential in the profile of light gray forest surface-gleyed soil on variants with long-term agricultural use without applying fertilizers and mineral fertilizer system solely compared with the soil under the forest are presented. On the basis of the conducted analyzes it was established, that soil tillage without fertilizer application and with mineral fertilizer solely has a different effect on ROP in the profile. In the soil without fertilization (control) as compared to the forest a moderate oxidizing (514 mV) and slightly oxidizing (437 mV) processes are happening. Prolonged application of mineral fertilizers to the soil (N65R68K68) significantly reduced the redox potential of all genetic horizons compared with forest and control without fertilizers. For the given fertilizer system the highest values of ROP were obtained in arable HEgl and underarable HEgl layers: 426 mV and 416 mV respectively. Redox potential sharply decreases with the depth to 398-311 mV, which characterizes processes occurring in the soil profile, as weakly reducing and close to moderately reducing.

Manufacturability Analysis for Solid Freeform Fabrication

1999 ◽  
Author(s):  
R. K. Arni ◽  
S. K. Gupta
Keyword(s):  
Systematic Approach ◽  
Solid Freeform Fabrication ◽  
Second Step ◽  
Freeform Fabrication ◽  
Design Tolerance ◽  
The Face ◽  
The Right ◽  
The Given ◽  
Manufacturing Problems ◽  
Case Effect

Abstract This paper describes a systematic approach to analyzing manufacturability of parts produced using Solid Freeform Fabrication (SFF) processes with flatness, parallelism and perpendicularity tolerance requirements on the planar faces of the part. SFF processes approximate objects using layers, therefore the part being produced exhibits stair-case effect. The extent of this stair-case effect depends on the angle between the build orientation and the face normal. Therefore, different faces whose direction normal is oriented differently with respect to the build direction may exhibit different values of inaccuracies. We use a two step approach to perform the manufacturability analysis. We first analyze each specified tolerance on the part and identify the set of feasible build directions that can be used to satisfy that tolerance. As a second step, we take the intersection of all sets of feasible build directions to identify the set of build directions that can simultaneously satisfy all specified tolerance requirements. If there is at least one build direction that can satisfy all tolerance requirements, then the part is considered manufacturable. Otherwise, the part is considered non-manufacturable. Our research will help SFF designers and process providers in the following ways. By evaluating design tolerances against a given process capability, it will help designers in eliminating manufacturing problems and selecting the right SFF process for the given design. It will help process providers in selecting a build direction that can meet all design tolerance requirements.

An accidental visualization of the Brillouin zone in an Ni–W alloyviadiffuse scattering

2013 ◽  
Vol 46 (4) ◽  
pp. 1211-1215 ◽  
Author(s):  
Sascha B. Maisel ◽  
Nils Schindzielorz ◽  
Stefan Müller ◽  
Harald Reichert ◽  
Alexei Bosak
Keyword(s):  
Fermi Surface ◽  
Brillouin Zone ◽  
Expansion Method ◽  
Reciprocal Space ◽  
Three Dimensions ◽  
X Rays ◽  
Solid State Physics ◽  
Seitz Cell ◽  
The Face ◽  
The Given

Solid state physics is built on the concept of reciprocal space. The physics of any given periodic crystal is fully defined within the Wigner–Seitz cell in reciprocal space, also known as the first Brillouin zone. It is a purely symmetry-based concept and usually does not have any eye-catching signature in the experimental data, in contrast with some other geometrical constructions like the Fermi surface. However, the particular shape of the Fermi surface of nickel allowed the visualization of the system of edges (skeleton) of the Wigner–Seitz cell of the face-centred cubic lattice in reciprocal space in three dimensions by the diffuse scattering of X-rays from Ni1−xWx(x= 0.03, 0.05, 0.08) single crystals. Employing a cluster-expansion method with first-principles input, it is possible to show that the observed scattering is inherent to the given nickel alloys and the crystal structures they form. This peculiar feature can be understood by considering the shape of the Fermi surface of pure nickel.

scholarly journals Huftiere und Verjüngung im Gebirgswald: eine Geschichte mit vielen Variablen und noch mehr Interaktionen | Ungulates and Tree Regeneration in Mountain Forests: an Issue with many Variables and even more Interactions

2000 ◽  
Vol 151 (4) ◽  
pp. 99-106 ◽  
Author(s):  
Josef Senn
Keyword(s):  
Tree Regeneration ◽  
Small Scale ◽  
Mountain Forest ◽  
Forest Trees ◽  
Mountain Forests ◽  
Wild Ungulates ◽  
Site Factors ◽  
The Past

After excessive cutting in Swiss mountain forests and extirpation of most of the wildlife during the past centuries, efficient forestry and hunting laws allowed a wide regeneration of the forests and a rapid increase of ungulate populations in the present century. As a consequence, the impacts of ungulates on the vegetation became obvious. Regeneration of forest trees, however, is influenced not only by ungulates, but by a number of physical site factors and biotic impacts. As these impacts and their interactions vary extensively, regeneration is neither spatially nor temporally constant. Most of the presently used tree-regeneration methods, however, assume constant conditions, which renders a proper evaluation of tree regeneration in mountain forests and the role of ungulates impossible. Furthermore, the effect of this variation on forest development and forest functions is unknown with regard to the long term. While society requires a multipurpose mountain forest, structured at a small scale, wild ungulates use their habitat at a larger scale. This often leads to conflicts. Consequently,solutions including different scales are necessary. A lack of knowledge will, therefore, have to be met by research making data available to the practice as well as through coordinated investigations and experiments.

A Context-Aware Model of Trust for Facilitating Secure Ad Hoc Collaborations

2010 ◽  
pp. 250-281 ◽  
Author(s):  
Indrajit Ray ◽  
Indrakshi Ray ◽  
Sudip Chakraborty
Keyword(s):  
Incomplete Information ◽  
Ad Hoc ◽  
Sensitive Information ◽  
Trust Value ◽  
Trust Relationships ◽  
The Face ◽  
Trust Models ◽  
Almost All ◽  
Ad Hoc Collaborations ◽  
The Given

Ad hoc collaborations often necessitate impromptu sharing of sensitive information or resources between member organizations. Each member of resulting collaboration needs to carefully assess and tradeoff the requirements of protecting its own sensitive information against the requirements of sharing some or all of them. The challenge is that no policies have been previously arrived at for such secure sharing (since the collaboration has been formed in an ad hoc manner). Thus, it needs to be done based on an evaluation of the trustworthiness of the recipient of the information or resources. In this chapter, the authors discuss some previously proposed trust models to determine if they can be effectively used to compute trustworthiness for such sharing purposes in ad hoc collaborations. Unfortunately, none of these models appear to be completely satisfactory. Almost all of them fail to satisfy one or more of the following requirements: (i) well defined techniques and procedures to evaluate and/or measure trust relationships, (ii) techniques to compare and compose trust values which are needed in the formation of collaborations, and (iii) techniques to evaluate trust in the face of incomplete information. This prompts the authors to propose a new vector (we use the term “vector” loosely; vector in this work means a tuple) model of trust that is suitable for reasoning about the trustworthiness of systems built from the integration of multiple subsystems, such as ad hoc collaborations. They identify three parameters on which trust depends and formulate how to evaluate trust relationships. The trust relationship between a truster and a trustee is associated with a context and depends on the experience, knowledge, and recommendation that the truster has with respect to the trustee in the given context. The authors show how their model can measure trust in a given context. Sometimes enough information is not available about a given context to calculate the trust value. Towards this end the authors show how the relationships between different contexts can be captured using a context graph. Formalizing the relationships between contexts allows us to extrapolate values from related contexts to approximate a trust value of an entity even when all the information needed to calculate the trust value is not available. Finally, the authors develop formalisms to compare two trust relationships and to compose two or more of the same – features that are invaluable in ad hoc collaborations.

Constructing tetrahedra with given face areas

2020 ◽  
Vol 104 (559) ◽  
pp. 63-73
Author(s):  
Michael Fox
Keyword(s):  
The Face ◽  
The Given ◽  
Unusual Problem

We tackle an unusual problem that, as far as I know, is not in the standard literature. To state it concisely I use what I call ‘valid sets’. We know that in any three or more positive quantities, only the largest can be half or more of the total value; and is then obviously greater than the sum of all the others. But if the largest is less than half the total of the set, it must be less than the sum of the others; and this is true for every element in this set. I call such a set ‘valid’. For example, the sides of a triangle are valid, as are the face areas of a tetrahedron. Our problem relates to the converse for a tetrahedron: given any four valid quantities, is there always a tetrahedron with those face areas? In this article I answer this by showing that, for any valid set, we can always construct the net of a corresponding tetrahedron. In fact, for any given valid set there is always an infinity of non-congruent tetrahedra with the given face areas. Although in general there are no formulae that give the exact edge lengths of these solids, I show that there are always several distinct infinite subsets that are constructible and whose edge lengths can be determined exactly.

scholarly journals Exact Formula for Computing the Hyper-Wiener Index on Rows of Unit Cells of the Face-Centred Cubic Lattice

2018 ◽  
Vol 26 (1) ◽  
pp. 169-187 ◽  
Author(s):  
Hamzeh Mujahed ◽  
Benedek Nagy
Keyword(s):  
Wiener Index ◽  
Exact Formula ◽  
Mathematical Induction ◽  
Binomial Coefficients ◽  
Integer Sequences ◽  
Cubic Lattice ◽  
Unit Cells ◽  
The Face ◽  
The Given ◽  
Sum Of Distances

Abstract Similarly to Wiener index, hyper-Wiener index of a connected graph is a widely applied topological index measuring the compactness of the structure described by the given graph. Hyper-Wiener index is the sum of the distances plus the squares of distances between all unordered pairs of vertices of a graph. These indices are used for predicting physicochemical properties of organic compounds. In this paper, the graphs of lines of unit cells of the face-centred cubic lattice are investigated. The graphs of face-centred cubic lattice contain cube points and face centres. Using mathematical induction, closed formulae are obtained to calculate the sum of distances between pairs of cube points, between face centres and between cube points and face centres. The sum of these formulae gives the hyper-Wiener index of graphs representing face-centred cubic grid with unit cells connected in a row. In connection to integer sequences, a recurrence relation is presented based on binomial coefficients.

scholarly journals Long-Term Temporal Changes of Precipitation Quality in Slovak Mountain Forests

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2920
Author(s):  
Jozef Minďaš ◽  
Miriam Hanzelová ◽  
Jana Škvareninová ◽  
Jaroslav Škvarenina ◽  
Ján Ďurský ◽  
...  
Keyword(s):  
Base Cations ◽  
Monitoring And Evaluation ◽  
Kendall Test ◽  
Chemical Components ◽  
Mountain Forest ◽  
Mountain Forests ◽  
Precipitation Regime ◽  
Pollution Effects ◽  
Icp Forests

The paper is focused on the evaluation of long-term changes in the chemical composition of precipitation in the mountain forests of Slovakia. Two stations with long-term measurements of precipitation quality were selected, namely the station of the EMEP (European Monitoring and Evaluation Programme) network Chopok (2008 m a.s.l.) and the station of the ICP Forests (International Co-operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests) network Poľana-Hukavský grúň (850 m a.s.l.). All basic chemical components were analyzed, namely sulfur (S-SO4), nitrogen (N-NH4, N-NO3), and base cations (Ca, Mg, and K) contained in precipitation. The time changes of the individual components were statistically evaluated by the Mann–Kendall test and Kruskal–Wallis test. The results showed significant declining trends for almost all components, which can significantly affect element cycles in mountain forest ecosystems. The evaluated forty one-year period (1987 to 2018) is characterized by significant changes in the precipitation regime in Slovakia and the obtained results indicate possible directions in which the quantity and quality of precipitation in the mountainous areas of Slovakia will develop with ongoing climate change.

scholarly journals Contribution of regeneration on dead wood to the spontaneous regeneration of a mountain forest

2012 ◽  
Vol 50 (No. 9) ◽  
pp. 405-414 ◽  
Author(s):  
K. Ježek
Keyword(s):  
Natural Regeneration ◽  
Dead Wood ◽  
Nature Reserve ◽  
Soil Surface ◽  
Mountain Forest ◽  
Silver Fir ◽  
Mountain Forests ◽  
Managed Forest ◽  
Vegetation Zone ◽  
Spontaneous Regeneration

In the Moravian-Silesian Beskids in the beech/spruce forest vegetation zone, the amount of dead wood was determined (pieces of wood and stumps) in five sample plots in a managed forest and in three plots in the National Nature Reserve (NNR) Kněhyně-Čertův Ml&yacute;n. In plots situated in the managed forest, 22 to 50 m<sup>3</sup>/haof lying wood was found. In the reserve, the volume of fallen wood ranged from 29 to 144 m<sup>3</sup>/ha. The number of stumps in sample plots in the managed forest ranged from 530 to 980 per ha. In the reserve, the number of new stumps did not increase any more and only stumps from the period before the NNR declaration occurred. On the dead wood, spruce is regenerated nearly exclusively. In the managed forest and in the NNR, the number of regenerated spruce plants ranged from 5,000 to 16,000 and from 600 to 4,500 per ha, respectively. In plots where the sufficient amount of dead lying wood and stumps occurred, the proportion of spruce plants regenerated on the substrates amounted to even 75%. Other species (beech and silver fir) regenerated only on the soil surface. A sufficient amount of dead wood for the germination of seedlings can significantly ensure the natural regeneration of spruce in mountain forests.

Challenges and opportunities of quantifying local CO2 advection at a mountain forest in the Alps

2020 ◽  
Author(s):  
Marta Galvagno ◽  
Georg Wohlfahrt ◽  
Peng Zhao ◽  
Edoardo Cremonese ◽  
Gianluca Filippa
Keyword(s):  
Eddy Covariance ◽  
Control Volume ◽  
Bare Soil ◽  
Mountain Forest ◽  
Mountain Forests ◽  
Flux System ◽  
Forest Sites ◽  
Challenges And Opportunities ◽  
Net Uptake ◽  
Advective Flows

&lt;p&gt;Mountain forests, which play an important role in the mitigation of anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; emissions are supposed to be heavily affected by climatic changes and extremes. Efforts towards the understanding of the physiological processes regulating mountain forest carbon and water fluxes are crucial to correctly manage and protect these key ecosystems. However, among the challenges in micrometeorological flux measurements in complex terrain, the unaccounted presence of advective CO&lt;sub&gt;2&lt;/sub&gt; fluxes has the potential to bias the daily and longer-term CO&lt;sub&gt;2&lt;/sub&gt; exchange estimates towards unrealistic net uptake, a bias that urgently needs to be accounted for in order to reduce uncertainties related to role of mountain forests in the global carbon cycle. On the other hand, given the typical local bi-directional wind system in mountains, information on advective flows at these sites could be easier to detect compared to other terrains. We present the results of a CO&lt;sub&gt;2&lt;/sub&gt; advection experiment conducted at a European larch site in Northern Italy (2100 m asl). The setup consisted of: the main eddy covariance flux tower (20 m), a sub-canopy eddy covariance flux system (2 m), a home-assembled system for measuring CO&lt;sub&gt;2&lt;/sub&gt; concentrations at three heights on the four sides of a 40 x 40 m control volume, composed by a solenoid valve system, multiple sampling inlets and a gas analyzer, and three automatic chambers measuring bare soil respiration (two chambers) and the net ecosystem CO&lt;sub&gt;2&lt;/sub&gt; exchange from the vegetated forest floor (one chamber). Results show that: i) advection is a not-negligible fraction of the total net ecosystem CO&lt;sub&gt;2&lt;/sub&gt; exchange of this forest, ii) coupling measurements of above and below canopy eddy covariance in mountain forest sites could emerge essential for detecting/estimating the unaccounted CO&lt;sub&gt;2&lt;/sub&gt; flux&lt;/p&gt;

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