scholarly journals Wenn Baumwunden dazu beitragen, Steinschlagmodelle weiterzuentwickeln

2017 ◽  
Vol 168 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Verena Eichenberger ◽  
Brian McArdell ◽  
Marc Christen ◽  
Daniel Trappmann ◽  
Markus Stoffel

When tree scars contribute to develop rockfall models Rockfall is an often occurring natural hazard in mountainous areas. Because rocks proceed very quickly with different types of motion, and because their run-out path is influenced by several factors, the implementation of rockfall processes in numerical models is complex. This article presents the methods of visual scar identification on trees and of measuring rock deposits, to validate the accuracy of the RAMMS::Rockfall model within the active rockfall area of Meretschibach (Canton of Valais, Switzerland). Scenarios with different rock shapes and modified terrain parameters were applied to test the sensitivity of the model to these parameters. Using scans of natural rocks from the field site, which are representative in shape and volume resulted in more realistic modelled median jump heights compared to rocks of the same size (small or large), but also to standard RAMMS rocks which were quite similar in shape and volume to the scanned rocks. The best simulations resulted when the terrain type was defined as two classes softer than registered in terrain. In this case, the difference between the simulated median jump height and the height of the scars on trees was just 23 cm. These results led to improvements in the model and handbook. This study highlights the importance of precise field data to better specify input parameters for rockfall modelling.

Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Tim Tofan ◽  
Rimantas Stonkus ◽  
Raimondas Jasevičius

The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3988
Author(s):  
Fátima Ternero ◽  
Pedro M. Amaral ◽  
Jorge Cruz Fernandes ◽  
Luís Guerra Rosa

A type of disc-on-plate test methodology was used to determine the wear behavior of metallic binders employed in the manufacturing of diamond impregnated tools. The disc consists of a special circular wheel that allows the binder materials alone (i.e., without diamond, but sintered under conditions identical to those of the complete tool) to be tested against a plate of stone material under pre-determined testing conditions. The testing conditions are intended to be equivalent to those used in the industrial processes. Using plates of five types of granite and one type of marble, this work comprises wear tests of 15 different types of metallic binders and two sintering modes conducted under, at least, three different values of contact-force. The analysis of the results demonstrated that the wear of the binders can be related to their mechanical properties through an empirical expression. The larger the difference between the characteristics of the tribological pair (binder versus stone), the higher is the correlation between the experimental wear data and the values given by the empirical expression. The relationships presented in this work allow predicting the wear behavior of the binder, and therefore may help in the design process of diamond tools. There was a clear difference between the wear behavior of metallic binders when they were employed against the two main classes of stone under analysis (marble and granite).


2021 ◽  
Vol 2 (1) ◽  
pp. 17-23
Author(s):  
Subiyanto Subiyanto ◽  
Nira na Nirwa ◽  
Yuniarti Yuniarti ◽  
Yudi Nurul Ihsan ◽  
Eddy Afrianto

The purpose of this study was to determine the hydrodynamic conditions at Bojong Salawe beach. The method used in this research is a quantitative method, where numerical data is collected to support the formation of numerical models such as wind, bathymetry, and tide data. The hydrodynamic model will be made using Mike 21 with the Flow Model FM module to determine the current movement pattern based on the data used. In the west monsoon with a maximum instantaneous speed of 0.04 - 0.08 m/s, while in the east monsoon it moves with a maximum instantaneous speed of 0,4 – 0,44 m/s. The dominant direction of current movement tends to the northeast. The results indicate the current speed during the east monsoon is higher than the west monsoon. The difference in the current speed is also influenced by the tide conditions; higher during high tide and lower during low tide. Monsoons also have a role in the current movements, though the effect is not very significant.


2021 ◽  
Vol 43 (2) ◽  
pp. 51-55
Author(s):  
Katherine Fox ◽  
Victor Garcia

Abstract Traditionally, ethnography is an enterprise based on face-to-face contact with research populations. Preventive measures designed to stop the spread of COVID-19, such as sheltering in place and maintaining social distance, have disrupted this important interaction and how anthropologists gather field data. New strategies are needed to overcome this restriction, especially when our research involves Latinx diasporic populations. Drawing on our current research that, to one degree or another, involves Latinx refugee, immigrant, and migrant populations, we make recommendations for using different media for maintaining virtual social contact and interviewing. Trust and rapport are key components of ethnographic research, and it is important to maintain a human connection within one’s field site, through this pandemic and beyond.


2015 ◽  
Vol 15 (11) ◽  
pp. 2569-2583 ◽  
Author(s):  
F. Frank ◽  
B. W. McArdell ◽  
C. Huggel ◽  
A. Vieli

Abstract. This study describes an investigation of channel-bed entrainment of sediment by debris flows. An entrainment model, developed using field data from debris flows at the Illgraben catchment, Switzerland, was incorporated into the existing RAMMS debris-flow model, which solves the 2-D shallow-water equations for granular flows. In the entrainment model, an empirical relationship between maximum shear stress and measured erosion is used to determine the maximum potential erosion depth. Additionally, the average rate of erosion, measured at the same field site, is used to constrain the erosion rate. The model predicts plausible erosion values in comparison with field data from highly erosive debris flow events at the Spreitgraben torrent channel, Switzerland in 2010, without any adjustment to the coefficients in the entrainment model. We find that by including bulking due to entrainment (e.g., by channel erosion) in runout models a more realistic flow pattern is produced than in simulations where entrainment is not included. In detail, simulations without entrainment show more lateral outflow from the channel where it has not been observed in the field. Therefore the entrainment model may be especially useful for practical applications such as hazard analysis and mapping, as well as scientific case studies of erosive debris flows.


2015 ◽  
Vol 15 (9) ◽  
pp. 1963-1972 ◽  
Author(s):  
L. Turconi ◽  
D. Tropeano ◽  
G. Savio ◽  
S. K. De ◽  
P. J. Mason

Abstract. The study area (600 km2), consisting of Orco and Soana valleys in the Western Italian Alps, experienced different types of natural hazards, typical of the whole Alpine environment. Some of the authors have been requested to draw a civil protection plan for such mountainous regions. This offered the special opportunity (1) to draw a lot of unpublished historical data, dating back several centuries mostly concerning natural hazard processes and related damages, (2) to develop original detailed geo-morphological studies in a region still poorly known, (3) to prepare detailed thematic maps illustrating landscape components related to natural conditions and hazards, (4) to thoroughly check present-day situations in the area compared to the effects of past events and (5) to find adequate natural hazard scenarios for all sites exposed to risk. The method of work has been essentially to compare archival findings with field evidence in order to assess natural hazard processes, their occurrence and magnitude, and to arrange all such elements in a database for GIS-supported thematic maps. Several types of natural hazards, such as landslides, rockfalls, debris flows, stream floods and snow avalanches cause huge damage to lives and properties (housings, roads, tourist sites). We aim to obtain newly acquired knowledge in this large, still poorly understood area as well as develop easy-to-interpret products such as natural risk maps.


Aksioma ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 57-73
Author(s):  
Nurdin Nurdin ◽  
Ita Sarmita Samad ◽  
Sardia Sardia

Abstract: The theory distinguishes human based on four different personality types such as: sanguine, choleric, melancholic, and phlegmatic. Different types of personality caused by differences in the dominant fluid in the body. These differences will result in terms of behavior, ways of thinking and to get along. The type of this research that is descriptive qualitative which it is describing the logical reasoning based on Hippocrates personality types. The logical reasoning is analyzed through the four types of personality in relation to mathematical problem solving. The Analysis is done based on the logical reasoning indicator/ subindicator and the steps of problem solving stated by Polya. The result shows that there is a reasoning difference on each type of personalities. The difference can be terms of the strenght or the weakness. Sanguine is quicker in understanding problems and communicating results, choleric is more accelerated in work, melancholic is more perfect at work, and  phlegmatic is superior in terms of accuracy. Keywords: Logical reasoning, Hippocrates, sanguine, choleric, melancholic, phlegmatic


2011 ◽  
Vol 1 (1) ◽  
pp. 16-24 ◽  
Author(s):  
Oddbjørn Leirvik

In this article, I discuss how insights from Martin Buber’s and Emmanuel Levinas’ philosophies of dialogue have enlightened my own experience of inter-faith dialogue in Norway. Central perspectives here are Buber’s notion of ’the realm of the between’ and Levinas’ emphasis on asymmetry and vulnerability. Some other philosophers’ reasonings about dialogue are also considered, from the overall perspective of ’practice in search of theory’. In connection with a distinction be-tween different types of dialogue (’spiritual’ and ’necessary’), the difference between government initiated ’dialogue’ and initiatives originating from the faith communities (i.e., civil society) are discussed. The last part of the article analyses the notion of ’(mutual) change’ which is often brought forward when discussing the aims of interfaith dialogue. In this connection, religious education in school is also considered as a possible arena for dialogue—and ’change’.


2008 ◽  
Vol 55 (4) ◽  
pp. 221-228
Author(s):  
Violeta Pavlovic ◽  
Slavoljub Zivkovic

Aim: To evaluate the effect of irrigation techniques, i.e. different types of irrigation needles, on the quality of cleaning of root canal walls using scanning electron microscopy (SEM). Material and Method: The study was conducted on 16 extracted, single-rooted, human teeth. The samples were allocated to two experimental groups depending on the type of the irrigation needle. Conventional needles were used for the irrigation of Group I and laterally perforated ones for Group II. All root canals were instrumented using K files and the Step-back technique. During instrumentation, all samples were irrigated with 2.5 % sodium hypochlorite solution followed by final irrigation with 17 % EDTA for 1 min. After that, all samples were irrigated with 10 ml of distilled water. The roots were, then, sectioned longitudinally and middle one third of each root canal was analyzed using SEM. Quantitative analysis was based on criteria by H?lsmann et al. Results: The obtained results showed that the more efficient removal of debris and the smear layer was accomplished in the group of samples irrigated using laterally perforated needles than conventional needles. The difference between the investigated irrigation techniques were statistically significant (p<0.01). Conclusion: The use of laterally perforated needles for irrigation allows more efficient cleaning of root canal walls, i.e. the removal of debris and the smear layer.


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