Model of Thermal Mechanism of Subclass A1 Fire Extinguishing with General Purpose Fire Extinguishing Powder in Non-Stationary Heat Exchange Conditions

The aim of the paper was to develop a model of thermal extinguishing mechanism using dry chemical powder taking into account the inertia of heat transfer to powder particles during unsteady heat exchange to identify the optimal conditions for extinguishing of A1 class fires with powders.The method of experimental and mathematical modelling of fire extinguishing process using dry chemical powder with short-term effect on the fire was used to achieve the goal. The experimental dependences of the extinguishing time and unit consumption of the extinguishing powder on the intensity of the powder supply to the combustion zone in extinguishing of subclass A1 fire in same area and in a limited volume were obtained. The mathematical model of a thermal extinguishing mechanism using dry chemical powder has been developed, taking into account the inertia of heat transfer to powder particles during unsteady heat exchange.Analysis of the regularities of extinguishing the subclass A1 fire using powder with a short feeding it into the fire indicates the presence of optimum values of unity consumption of powder on the fire from the intensity of feeding it into the fire. The presence of this optimum is due to the inertia of extinguishing the subclass A1 fire using powder due to the finiteness of the heat transfer time to the particles of the extinguishing powder and the limited time of interaction of particles with the combustible material.The theoretical analysis of the fire extinguishing process over the area taking into account the inertia of heat transfer to the powder particles at non-stationary heat exchange are carried out. The results of the analysis are in qualitative agreement with the results of the experimental study of the regularities of extinguishing of model fire foci of subclass A1 with General-purpose fire extinguishing powder.

The influence of feeding on muscle tissues composition in cage reared bluefin tuna (Thunnus thynnus)

Capture-based tuna aquaculture rates as one of the most important aquaculture activities in Cro-atia, where juvenile tuna are reared in cages for over a year long period in order to increase substan-tially their weight. The aim of this study was to assess the effect of length and intensity of feeding on biochemical composition (total fat, moisture, dry matter, carbohydrates and protein content) of tuna (Thunnus thynnus) white muscle tissues in newly caught tuna prior to feeding (NCTPF) versus far-med tuna kept in rearing circular cages in the Vela Grska Bay, Adriatic Sea (LAT 43°17’40,6984”N, LONG 016°28’58,4315”E (WGS84)) between 2001 and 2004. Farmed tunas from all cages were fed with the feed consisting of domestic small pelagic fish, or with mixtures containing North Sea herring (Clupea harengus) and Sardina pilchardus, for five months (cage 3), eight months (cage 4) or 21 months (cages 1 and 2). A low content of moisture and high content of dry matter including fat was observed in farmed tuna muscles compared to wild-caught tuna. In farmed tuna muscles, measured moisture was 55.26% in cage 1, 39.95% in cage 2, 54.64% in cage 3 and 49.70% in cage 4. These results are significantly lower than moisture measured in NCTPF (80.36%). Content of dry matter found in farmed tuna muscles also differed greatly between wild tuna (19.64%) and far-med tuna, but also between the cages (44.74% in cage 1, 60.05% in cage 2, 45.36% in cage 3 and 50.30% in cage 4). In NCTPF, muscle tissues total fat encompassed less than 1% of the total body weight, while it reached over 20% of total body mass in farmed fed tuna (20.62% in cage 1, 42.50% in cage 2, 20.97% in cage 3 and 20.57% in cage 4). These results demonstrate that high fat content can be achieved already after five months of intensive feeding. Higher content of proteins was also found in aquacultured tuna (18.60% in cage 1, 16.00% in cage 2, 15.09% in cage 3 and 20.58% in cage 4) compared to wild-caught tuna (13.77%). There were no differences in carbohydrates con-tent between tuna farmed in different cages and NCTPF tuna, indicating glycogen as a less optimal indicator of muscle tissue quality in farmed tuna of the present study.

Food and feeding habits of mangrove shellfish, Telescopium telescopium (Linnaeus, 1758) in Bangladesh

Experiments on food and feeding behaviour of Telescopium telescopium was conducted in the Sundarbans and surrounding area during January to December 2008. The stomach contents of 960 individuals were examined, in which 74.79% and 25.21% were found with and without food respectively. Of the 74.79% stomach with food 16.98%, 18.23%, 21.14% and 18.44% were full fed, ¾ fed, ½ fed and ¼ fed respectively. The intensity of feeding in tidal cycle and monthly sampling periods showed a clear trend. The snail fed mainly at low tide and preferred grazing at day time in winter and night in summer in spring tide. They consumed fine particulate mud along with organic detritus from upper intertidal surface sediment using its long extensible snout. In the time of neap tide especially in winter when the muddy habitat of Telescopium telescopium became dry, the animal survived a long time without food.Bangladesh J. Zool. 41(2): 233-239, 2013

Zur Erhebung des Einflusses von Wildtieren auf die Waldverjüngung | Investigation of the Influence of Wild Animals on Forest Regeneration

The existing information on the influence of wild animals on forest regeneration is an important basis for solution-finding for the ever-increasing problems of regeneration. Sufficient expert estimations allow the problematic areas to be recognised at a regional level and to be separated from the others. Indicator areas of the problematic sites, which should amount to at least 30 ha, the woody plants assessed according to tree species, size class and feeding damage to tips during the vegetation period of the previous year and the resting period directly before the assessment time in spring, can be counted on systematically distributed, permanent, simple sample circles. The interpretation of regenerative parameters should be based particularly on the intensity of feeding damage and its limited values according to EIBERLE and NIGG (1987) as well as the stem numbers. Pairs of comparable areas, one fenced and one unfenced respectively,are suitable as sample subjects for selective small-scale site observation. They present information on the influence of wild animals on indicator areas of the size of a stand or of a micro-site favourable to regeneration.

The biology of a landlocked form of the normally catadromous salmoniform fish Galaxias maculatus (Jenyns). IV. Nutritional cycle

The nutritional cycle of a landlocked form of the normally catadromous streamdwelling fish Galaxias maculatus inhabiting Lake Modewarre (south-western Victoria) was studied by following seasonal fluctuations in its general body condition, liver condition, visceral fat stores, and intensity of feeding. The interrelations of these parameters of nutritional condition and the gonadal cycle (which was described in a previous paper in the same series) are then considered. The conclusion is drawn that the landlocked jollytail, like some of the related salmonid fishes, belongs to the nutritional category of "fat fishes", in which lipid reserves are mobilized from fat stores other than the liver for development of the gametes and the reproductive effort.

FEEDING BEHAVIOUR OF THE PALES WEEVIL, HYLOBIUS PALES (COLEOPTERA: CURCULIONIDAE): I. SYNERGISTIC EFFECTS WITH LOBLOLLY PINE PHLOEM EXTRACTS

A bioassay with elder pith wafers was developed to measure sustained feeding of the pales weevil, Hylobius pales (Herbst). Sucrose, fructose, glucose, and extracts of phloem of loblolly pine (Pinus taeda L.) were compared in three-choice experiments. Intensity of feeding indicated a synergistic effect occurred when sucrose and phloem lipid were present together. The non-polar or neutral lipid fraction of phloem stimulated more feeding than did the polar lipid fraction.

A New Type of Coprometer for Laboratory and Field Use

It is often desirable to establish the relationship between the amount of feeding of an insect and the prevailing meteorological conditions. With colonial insects, especially, it is difficult to determine visually whether members of a colony are feeding heavily, moderately, or lightly. If periodic measurements of frass drop are made, more reliable information may be obtained, for such measurements have proved to be reliable indicators of the intensity of feeding (Gornitz (1933); Monro (1935; Morris (1949), and Taranukha (1937)).