scholarly journals Impact induced mechanical damage of Agria potato tubers

2012 ◽  
Vol 51 (No. 2) ◽  
pp. 39-43 ◽  
Author(s):  
J. Blahovec

Potato variety Agria was cultivated in different fertilisation and/or irrigation regimes. Tuber damage after impact was studied two months after the harvest with aim to find some relation between the regime of cultivation and impact test tuber damage. It was found that tuber cracking and/or crushing belongs to the most frequent mechanisms of damage masking usual bruising in many cases. Most severe tuber cracking was observed for cultivation with irrigation and classical methods of fertilisation. On the other hand, bruising was most frequent in case without any irrigation and fertilisation and in cases used for fertilisation the pig slurry. In every cultivation regime the bruising was more pronounced in narrower tuber side in comparison to the wider flat side.

2012 ◽  
Vol 52 (No. 3) ◽  
pp. 81-86
Author(s):  
J. Blahovec ◽  
A. Hejlová ◽  
J. Vacek

The Agria potato tubers were grown in 2005 in cultivation regimes involving different irrigation and fertilisation levels and forms. The impact induced tuber damage was simulated dynamically by an impact pendulum test and studied with the aim to detect some relationship between the cultivation regimes and the type and extent of the damage. The usual bruising presented as black spots is in many cases masked by other mechanisms of damage, e.g. by tuber cracking and/or crushing. The highest degree of tuber cracking and at the same time the least frequent bruising were observed for tubers cultivated in the regime with irrigation and without fertilising. The bruising was more pronounced in the narrower tuber side in comparison to the wider flat side in all cultivation regimes. Some results could be compared with similar previous measurements performed on tubers from the same field experiment organised during three successive years 2003–2005. The flatter side parts of the Agria tubers are more sensitive to bruising than the more oblique ones. The bruise spot shape depends mainly on its dimension. The role of different cultivation regimes can be interpreted in this way.


Author(s):  
Д.В. КОЛОШЕИН ◽  
Н.В. ЦЫГАНОВ ◽  
Л.А. МАСЛОВА ◽  
С.Н. КУЛЬКОВ

Проблема и цель. Целью проводимого исследования является снижение механических повреждений в процессе погрузки, перевозки клубней и закладке картофеля на хранение. Методология. Повреждения клубней влияют на лежкость картофеля при хранении. Для достижения цели исследования были определены в соответствии со стандартами предельно допустимые значения энергии удара и высоты падения клубней. Анализ факторов, влияющих на появление повреждений клубней картофеля, позволил группе авторов предложить классификацию основных факторов. Дальнейший анализ показал, что факторы или причины, влияющие на появление повреждений у клубней картофеля, делятся на несколько основных видов. Биологический фактор возникновения повреждений клубней картофеля, как показывает практика, можно минимизировать за счет районирования сортов картофеля (использование наиболее пригодных сортов картофеля для машинной уборки) и соблюдения технологии уборки урожая. Технический фактор в первую очередь зависит от конструктивных особенностей картофелеуборочной техники. Результаты. Проведенные исследования позволили уточнить причины механических повреждений клубней, получаемых при закладке на хранение картофеля в контейнеры. Были определены также размерно-массовые характеристики сорта картофеля «Гала» Заключение. По итогам проведенных исследований было определено, что при загрузке контейнеров и хранении картофеля, а также с целью снижения повреждений клубней необходимо применять различные типы гасителей ударной нагрузки. Самым простым гасителем будут являться ремни из прорезиненной ткани, с креплением по краям контейнера. Problem and goal. The purpose of the study is to reduce mechanical damage during loading, transportation of tubers and laying potatoes for storage. Methodology. Damage to the tubers afects the shelf life of potatoes during storage. Thus, in order to achieve the goal of the study, the maximum permissible values of the impact energy and the fall height of the tubers were determined in accordance with the standards. For this purpose, a group of authors proposed a classifcation of factors that afect the appearance of damage to potato tubers. The analysis of the factors allowed us to identify the classifcation of the necessary factors that afect the appearance of mechanical damage. Further analysis showed that the factors or causes that afect the appearance of damage in potato tubers are divided into several main types. The biological factor of damage to potato tubers, as practice shows, can be minimized by zoning potato varieties (using the most suitable potato varieties for machine harvesting) and compliance with harvesting technology. The technical factor, as practice shows, primarily depends on the design features of potato harvesting equipment. Results. The conducted research allowed us to clarify the causes of mechanical damage to tubers obtained when storing potatoes in containers. The size and mass characteristics of the potato variety "Gala" were also determined» Conclusion. Based on the results of the conducted studies, it was determined that various types of shock absorbers should be used to load containers and store potatoes, as well as to reduce damage to tubers. The simplest extinguisher will be belts made of rubberized fabric, with fastening at the edges of the container.


2011 ◽  
Vol 32 (No. 3) ◽  
pp. 89-95 ◽  
Author(s):  
K. Hamouz ◽  
J. Čepl ◽  
P. Dvořák

In 1995–1997 seven varieties of potatoes were cultivated in field trials in twelve localities in the Czech Republic. Six of the twelve localities were situated in lower, warmer and drier areas with fertile, predominantly loamy soils. The other localities were situated in higher, colder and more humid areas. They represent traditional potato-growing areas  in the Czech Republic. After harvest  potato tubers of all varieties were analysed for resistance to mechanical damage, dry matter content, reducing sugar (RS) content, nitrate content, polyphenol content. Glycoalkaloid (GA) content  was analysed only in Karin variety. In all experimental years potatoes cultivated at lower altitudes contained less RS (by 22%), less polyphenolic compounds (by 5.8%), higher percentage of tubers not mechanically damaged with the rebound pendulum (by 12.7%), compared to tubers from higher localities. On the other hand, tubers grown at lower altitudes contained more nitrates (by 26.8%) in all three years. Over the three years, the average of results in Karin variety did not demonstrate the influence of environmental conditions of the areas on GA content in tubers.    


1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró

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.


Author(s):  
A. V. Crewe

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.


Author(s):  
K.H. Westmacott

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.


2005 ◽  
Vol 19 (3) ◽  
pp. 129-132 ◽  
Author(s):  
Reimer Kornmann

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.


Author(s):  
Stefan Krause ◽  
Markus Appel

Abstract. Two experiments examined the influence of stories on recipients’ self-perceptions. Extending prior theory and research, our focus was on assimilation effects (i.e., changes in self-perception in line with a protagonist’s traits) as well as on contrast effects (i.e., changes in self-perception in contrast to a protagonist’s traits). In Experiment 1 ( N = 113), implicit and explicit conscientiousness were assessed after participants read a story about either a diligent or a negligent student. Moderation analyses showed that highly transported participants and participants with lower counterarguing scores assimilate the depicted traits of a story protagonist, as indicated by explicit, self-reported conscientiousness ratings. Participants, who were more critical toward a story (i.e., higher counterarguing) and with a lower degree of transportation, showed contrast effects. In Experiment 2 ( N = 103), we manipulated transportation and counterarguing, but we could not identify an effect on participants’ self-ascribed level of conscientiousness. A mini meta-analysis across both experiments revealed significant positive overall associations between transportation and counterarguing on the one hand and story-consistent self-reported conscientiousness on the other hand.


2019 ◽  
Vol 50 (2) ◽  
pp. 80-93
Author(s):  
Jort de Vreeze ◽  
Christina Matschke

Abstract. Not all group memberships are self-chosen. The current research examines whether assignments to non-preferred groups influence our relationship with the group and our preference for information about the ingroup. It was expected and found that, when people are assigned to non-preferred groups, they perceive the group as different to the self, experience negative emotions about the assignment and in turn disidentify with the group. On the other hand, when people are assigned to preferred groups, they perceive the group as similar to the self, experience positive emotions about the assignment and in turn identify with the group. Finally, disidentification increases a preference for negative information about the ingroup.


1961 ◽  
Vol 6 (6) ◽  
pp. 222-223
Author(s):  
Edwin G. Boring
Keyword(s):  

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