AN ANALYSIS OF THE WEAR OF PLOUGHSHARES WITH VARIOUS TECHNOLOGICAL SOLUTIONS

Tribologia ◽  
2016 ◽  
Vol 267 (3) ◽  
pp. 139-151 ◽  
Author(s):  
Jerzy NAPIÓRKOWSKI ◽  
Magdalena LEMECHA
Keyword(s):  
Sandy Soil ◽  
The Other ◽  
Soil Conditions ◽  
Additional Material ◽  
Chromium Carbides ◽  
Wear Process ◽  
Other Hand ◽  
Natural Operation ◽  
Martensitic Microstructure

The paper analyses wear processes in various technological forms of ploughshares. Tests involved ploughshares made of Hardox 500, B 27 and 38GSA steel, as well as Hardox 500 steel with the cutting edges hardfaced by means of an El – Hard 63 electrode on the front and back sides, as well as 38GSA steel hardfaced by means of an EStelMn60 electrode. The tests were conducted during natural operation when processing sandy soil. During the tests, the changes in the mass and geometry of ploughshares were measured as a function of the processed area. Ploughshares made of steel were characterised by a diverse martensitic microstructure. The hardfaced layers, on the other hand, were dominated by chromium carbides with alloy ferrite. It has been concluded that the use of hardfaced layers considerably impact the decrease in the intensity of wear of the tested working elements. On the other hand, no significant differences were observed in the wear processes of hardfaced ploughshares depending on the native and additional material and the place of the application of the hardfacing agent. In the analysed soil conditions, ploughshares made of steel did not exhibit any significant differences in the wear process.

scholarly journals Differences in soil organic matter and humus of sandy soil after application of biochar substrates and combination of biochar substrates with mineral fertilizers

2020 ◽  
Vol 23 (3) ◽  
pp. 117-124
Author(s):  
Dušan Šrank ◽  
Vladimír Šimanský
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Content ◽  
Humic Substances ◽  
Sandy Soil ◽  
The Other ◽  
Mineral Fertilizers ◽  
Other Hand ◽  
Sheep Manure ◽  
The Impact

The effort to achieve the sustainable farming system in arable soil led to the intensive search for a new solution but an inspiration can also be found in the application of traditional methods of soil fertility improvement as it is shown in numerous examples in history. Recently many scientific teams have focused their attention on the evaluation of biochar effects on soil properties and crop yields. Since there are a lot of knowledge gaps, especially in explanations how biochar can affect soil organic matter (SOM) and humus substances, we aimed this study at the solution of these questions. Therefore, the objective of the experiment was to evaluate the impact of two biochar substrates (B1 – biochar blended with sheep manure, and B2 – biochar blended with sheep manure and the residue from the biogas station) at two rates (10 and 20 t ha-1) applied alone or in combination with mineral fertilizers (Urea was applied in 2018, at rate 100 kg ha-1, and Urea at rate 100 kg ha-1 + AMOFOS NP 12-52 at 100 kg ha-1 were applied in 2019) on the quantity and quality of SOM and humus of sandy soil (Arenosol, Dolná Streda, Slovakia). The results showed that application of the biochar substrates together with mineral fertilizers (MF) had more pronounced effect on the organic matter mineralization in the sandy soil which resulted in low accumulation of soil organic carbon (Corg) and labile carbon compared to biochar substrates treatments without MF. The share of humic substances in Corg significantly decreased by 16, 50, 16 and 24% in B1 at 10 t ha-1, B1 at 20 t ha-1, B2 at 10 t ha-1 and B2 at 20 t ha-1 treatments, respectively, compared to the control. A similar tendency was observed for biochar substrates treatments + MF, compared to MF control. The carbon content of humic substances (CHS) was equal to 4.40 – 5.80 g kg-1 and the biochar substrates had statistically significant influence on CHS content. On average, there was a smaller decrease of CHS in B1 at rate 10 t ha-1 than at rate 20 t ha-1 and no effect of B2 compared to control. The carbon content of fulvic acid (CFA) was 9% higher in B1 at 10 t ha-1, and 20 t ha-1, 47% higher in B2 at 10 t ha-1 and 17% higher in B2 at 20 t ha-1 compared to control. As a result of biochar substrates + MF application, the reduction in CFA was observed. The results showed a decrease of CHA : CFA ratio with association to biochar substrates alone application compared to control on one hand, and a wider of CHA : CFA ratio in biochar substrates + MF treatments in comparison to MF control on the other hand. Humus stability was increased in biochar substrates alone treatments compared to control, on the other hand, compared to MF control, the application of biochar substrates + MF resulted in a lower humus stability.

scholarly journals Control contribution for wear bearing recurrence process

2014 ◽  
Vol 62 (4) ◽  
pp. 691-700
Author(s):  
K. Wierzcholski ◽  
A. Miszczak
Keyword(s):  
Control Problem ◽  
Variable Coefficients ◽  
The Other ◽  
Infinite Time ◽  
Wear Process ◽  
Factor Method ◽  
Recurrence Equations ◽  
Other Hand ◽  
Operation Process ◽  
Methods Of Control

Abstract This paper presents the methods of control problem solutions using recurrence equations implementation and UOS transformation for the bearing wear estimation during the finite and infinite time units of an operation process. If we have two wear value increase processes then very important is information which process is divergent more slowly. On the other hand, in comparison with two convergent processes we must decide which process is convergent more quickly. The wear process is determined mostly by the summation factor method. Such a method is applied for the solutions of recurrence equations with variable coefficients

scholarly journals The stuble-field plant communities in South-East Poland. Part V. The comparative characteristics of stuble-fleld plant communities

2013 ◽  
Vol 46 (1) ◽  
pp. 99-127
Author(s):  
Czesława Trąba
Keyword(s):  
Plant Communities ◽  
The Other ◽  
Euphorbia Esula ◽  
Soil Conditions ◽  
Hydrological Conditions ◽  
Mechanical Structure ◽  
Field Plant ◽  
Other Hand ◽  
Setaria Glauca

In this of the presented paper results of the studies conducted in preceding four parts (I-IV) were synthetically assumed. On that background a comparative characteristics of specified stuble-field plant communities was conducted. It contains the most important features of communities and seats, in which they appear. In climatically, geomorphologically, hydrologically and with respect to soils differentiated conditions of South-East Poland, especially in former Rzeszów region, there were described stubble-field plant communities occurring as well on lowland, as on highland agricultural utility complexes. There were analysed 359 phytosociological records, in which 232 ones came from lowland, while 127 from highland complexes. The specified communities were included to two orders: <i>Secali-Violetalia arvensis</i> (suborder <i>Polygono-Chenopodienalia</i> : alliances <i>Eu-Polygono-Chenopodion</i> and <i>Panico-Setarion</i>) and <i>Cyperetalia fusci</i> (alliance <i>Nanocyperion flavescentis</i>). On the lowland agricultural utility complexes specified were seven types of communities: 3 belonged to <i>Panico-Setarion</i> alliance (association <i>Digitarietum ischaemi</i>; community with <i>Setaria glauca</i> and association <i>Echinochloo-Setarietum</i>), 2 to <i>Eu-Polygono-Chenopodion</i> alliance (the community with <i>Euphorbia esula</i> and <i>Oxalis stricta</i> as well the community with <i>Veronica persica</i>), while 2 associations from the <i>Nanocyperion flavescentis</i> (<i>Hyperico-Spergularietum</i> and <i>Centunculo-Anthocerotetum</i>) alliance. On the other hand, on the highland complexes of South-East Poland only 3 communities were found: 1) with <i>Setaria glauca</i> included to <i>Panico-Setarion</i> alliance, 2) with <i>Veronica persica</i> from <i>Eu-Polygono-Chenopodion</i> alliance and 3) <i>Centunculo-Anthocerotetum</i> association from <i>Nanocyperion flavescentis</i> alliance. The specified floral types, as well as lower units (variants and sub variants), reflected the mechanical structure, hydrological conditions and pH soils in their seats, what confrumed a great differentiation of soil conditions on the tested area.

Convergences of Cumulative Wear after Time of Bearing Operation

2015 ◽  
Vol 220-221 ◽  
pp. 295-300
Author(s):  
Krzysztof Wierzcholski ◽  
Andrzej Miszczak
Keyword(s):  
Operation Time ◽  
The Other ◽  
Wear Process ◽  
Slide Bearing ◽  
Other Hand ◽  
Convergence And Divergence

The numerous machine exploitation problems in the field of the experimental and numerical wear slide bearing determination problems demand to know information referring the features of the sequence of the existing wear process during the operation time. The above-mentioned information includes the velocity of the wear values increases during the particular time units of the operation and convergence and divergence properties of the wear value increases are very important. If we have two wear value increase processes, then very important is information which process is divergent more slowly. On the other hand, in comparison between two convergent processes, we must decide which process is convergent more quickly.

Winter Leaching and the Manurial Value of Green Manures and Crop Residues for Winter Wheat

1931 ◽  
Vol 21 (3) ◽  
pp. 493-525 ◽  
Author(s):  
E. M. Crowther ◽  
T. J. Mirchandani
Keyword(s):  
Winter Wheat ◽  
Sandy Soil ◽  
Crop Residues ◽  
The Other ◽  
Green Manures ◽  
Excess Carbon ◽  
Experimental Station ◽  
Other Hand ◽  
Carbon Compounds

1. It is suggested that the striking failure of winter wheat grown in rotation with two summer crops of tares or mustard on the sandy soil the Woburn Experimental Station is due to the production of nitrate and ammonia from the green manures at times when the wheat is unable to use them efficiently and to the consequent loss of nitrate in the drainage. Owing to its low C: N ratio the nitrogen in tares nitrifies very rapidly and the loss by leaching is very great. Mustard, on the other hand, reduces the winter loss, but the nitrogen present in the mustard and that absorbed in the decomposition of the excess carbon compounds are liberated too slowly to be utilised efficiently by the wheat and much of the nitrate subsequently produced is also lost by leaching.

Effects of forest floor environment on germination and seedling establishment of two Bornean rainforest emergent species

1995 ◽  
Vol 11 (4) ◽  
pp. 517-527 ◽  
Author(s):  
Akira Itoh
Keyword(s):  
Seedling Establishment ◽  
Forest Floor ◽  
The Other ◽  
Light Environment ◽  
Primary Leaf ◽  
Soil Conditions ◽  
Leaf Production ◽  
Other Hand ◽  
Emergent Species

ABSTRACTSeeds of Dryobalanops aromatica and D. lanceolata (Dipterocarpaceae) were sown in gaps and understorey on a ridge and a valley in a Bornean rainforest. Germination rates were 92–100% regardless of site and species. On the ridge, the proportion of seedlings that opened primary leaves was larger in D. aromatica (19–30%) than in D. lanceolata (7–19%) due to higher root predation on D. lanceolata. In the valley, on the other hand, the proportion was larger in D. lanceolata (71–74%) than in D. aromatica (56%). After primary leaf production, seedlings of both species had higher survivorship in the gaps than in the understorey. Interactions between predators, soil conditions and light environment and their effects on seedling establishment are discussed.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

Can the Academic Self-Concept be Positive and Realistic?

2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann
Keyword(s):  
Academic Performance ◽  
Opposite Effect ◽  
Self Esteem ◽  
Point Of View ◽  
The Other ◽  
Self Concept ◽  
High Ability ◽  
Self Image ◽  
Other Hand

Summary: My comment is basically restricted to the situation in which less-able students find themselves and refers only to literature in German. From this point of view I am basically able to confirm Marsh's results. It must, however, be said that with less-able pupils the opposite effect can be found: Levels of self-esteem in these pupils are raised, at least temporarily, by separate instruction, academic performance however drops; combined instruction, on the other hand, leads to improved academic performance, while levels of self-esteem drop. Apparently, the positive self-image of less-able pupils who receive separate instruction does not bring about the potential enhancement of academic performance one might expect from high-ability pupils receiving separate instruction. To resolve the dilemma, it is proposed that individual progress in learning be accentuated, and that comparisons with others be dispensed with. This fosters a self-image that can in equal measure be realistic and optimistic.

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