Evaluation of palatability of 20 plant species as a food source for slugs Deroceras reticulatum (Mi.iller), Arion lusitanicus (Mabille) and Arion ruf us (Linnaeus) was performed under laboratory conditions in tests with multiple choices and without choice. Rate and degree of damage of seedlings and leaves of matured plants of herbs and winter oilseed rape were calculated. Based on conducted experiments, plant species preferred and rejected by particular slug species were defined. Plants that were preferred by all examined slug species were the following: Brassica napus, Conium maculatum and Lamium amplexicaule. Rejected plants were Polygonum nodosum and Plantago lanceolata. Slugs have showed differentiated preferences towards the remaining plant species.

U-10wt.%Zr-5wt.%RE fuel slugs for a sodium-cooled fast reactor (SFR) were conventionally prepared by a modified injection casting method, which had the drawback of a low fabrication yield rate of approximately 60% because of the formation of many metallic fuel scraps, such as melt residue and unsuitable fuel slug butts. Moreover, the metallic fuel scraps were classified as a radioactive waste and stored in temporary storage without recycling. It is necessary to develop a recycling process technology for scrap wastes in order to reduce the radioactive wastes of the fuel scraps and improve the fabrication yield of the fuel slugs. In this study, the additive recycling process of the metallic fuel scraps was introduced to re-fabricate the U-10wt.%Zr-5wt.%RE fuel slugs. The U-10wt.%Zr-5wt.%RE fuel scraps were cleaned on the surface impurity layers with a mechanical treatment that used an electric brush under an Ar atmosphere. The U-10wt.%Zr-5wt.%RE fuel slugs were soundly re-fabricated and examined to evaluate the feasibility of the additive process compared with the metallic fuel slugs that used pure metals.

The intensity of Arion lusitanicus occurrence and the damage degree of 31 crop species have been estimated. It has been found that the slug damaged lettuce and cabbage plants very heavily (Lactuca sativa L. var. capitata L., Brassica oleracea L. var. capitata L. f. alba) and many species of other vegetables (Cucumis sativus L., Phaseolus vulgaris L., Raphanus sativus L. subvar. radicula Pers.). Plant damages in the edge strips were also observed on rape and barley plantations attacked by this slug. The moving activity of particular individuals of Arion lusitanicus was varying. Planning of the experiments in a nested block design has made it possible to statistically determine tendencies of the slug movement. It was observed that when some individuals remained at the point where they were initially placed, others, 2 hours after, moved over 7 m away. The mean weighed length of pathway covered by a single individual and the mean movement rate of one were estimated for each of 9 observation dates. It has been found that slugs penetrating the site surface under observation displayed their tendencies to move towards more moist places and towards food sources.

Population studies on Arion lusitanicus, a slug species introduced into Poland, were carried out over the last decade. The slug occurs commonly in some areas and spreads out relatively quickly. It has an annual life cycle with eggs, and immature individuals overwinter. In the end of July A. lusitanicus begins copulation and three weeks later it lays eggs from which the first offspring hatch within a month. The copulation process and egg laying last until late fall. One A. lusitanicus can lay over 400 eggs. During the growing season there are two peaks of population density. This species feeds on plant material such as leaves, stems, bulbs, but also consumes animal material. The basic plant material are arable crops particularly vegetables and some species of agricultural crops, some fruit trees, ornamental plants, herbs and weeds. A. lusitanicus displays apparent food specialization and prefers certain cultivated and wild growing plants. A. lusitanicus shows large reproduction potential, wide food and ecologic tolerance, and is regarded as a serious pests occurring in home gardens.

Vegetables in addition to arable crops and ornamentals are also at high risk from slug and snail attack at all growth stages. The no-choice tests were conducted under laboratory conditions to assess the harmfulness of the slug Arion rufus (Linnaeus) and the snail Cepaea hortensis (Müller) to young vegetable plants. Ten species representing leaf and root vegetables, allium, brassica, cucurbit and edible pulse plants were chosen to compare their susceptibilities to feeding of these pests (agrotechnical classification – Polish National List of Varieties of Agricultural and Vegetable Plants 2005). The evaluation of the growth of the tested vegetables included a percentage of the damaged plant area and changes in aboveground plant mass. The trend toward increase of mass was defined by the means of regression analysis. Losses of aboveground plant mass resulting from pest feeding and plant growth restraint caused by the slug or the snail damage were assessed. Variance analysis of the general linear model and orthogonal contrasts were calculated to compare the vegetable groups included in the research. The highest losses of aboveground plant mass, by both pest species A. rufus and C. hortensis, were on common bean plants and the smallest on plants of leaf vegetables (lettuce, dill), brassica plants (cauliflower, white cabbage) and allium plants (garden onion).

Metallic fuel slugs containing rare-earth (RE) elements have high reactivity with quartz (SiO2) molds, and a reaction layer with a considerable thickness is formed at the surface of metallic fuel slugs. The surface characterization of metallic fuel slugs is essential for safety while operating a fast reactor at elevated temperature. Hence, it is necessary to evaluate the surface characteristics of the fuel slugs so that chemical interaction between fuel slug and cladding can be minimized in the reactor. When the Si element causes a eutectic reaction with the cladding, it deteriorates the metallic fuel slugs. Thus, it is necessary to examine the characteristics of the surface reaction layer to prevent the reaction of the metallic fuel slugs. In this study, we investigated the metallurgical characteristics of the surface reaction layer of fabricated U-10wt.%Zr-Xwt.%RE (X = 0, 5, 10) fuel slugs using injection casting. The results showed that the thickness of the surface reaction layer increased as the RE content of the metallic fuel slugs increased. The surface reaction layer of the metallic fuel slug was mainly formed by RE, Zr and the Si, which diffused in the quartz mold.