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Zwalczanie owadów - szkodników technicznych drewna za pomocą mikrofal

100%

Krajewski A.

Ochrona Zabytków

1990

nr 1

27-34

In 1 9 8 5— 1 9 8 7 , in the Research and Conservation Branch of the Ateliers for Conservation of Cultural Property State Enterprise in Warsaw, studies were carried out on the disinsectization of wood by means of microwaves 12.2 cm (2 .4 5 G H z ) in length, emitted in the form of a scattered field. In the experiments tw o field devices with 6 0 0 W and 1 4 0 0— 2 4 0 0 W of power, and a microwave chamber with 1 0 0 0 W of power (fig. 2) were used. Heating of the air-dry w o od through the use of microwaves was of a jumping nature (fig. 3 ). After a rapid, several-minute heating through microwaves, there followed a significantly slowe cooling process. The quickest heating took place in the layers closest to the antenna of the field device, while the weakest heating was in the layers farthest away. In the case of the microwave chamber, the middle layers of w o od became the most heated. Heating of the wood by means of radio waves of a high and very high frequency depends on the thickness of the wood (fig. 4 ), the course of the fibres, the humidity and density, and on the strength of microwave action. In the presented publication these dependencies are discussed against the background of results given in literature. As a result of experiments conducted on the larvae of the common Cerambycid (Hylotrupes bajulus L.), the death watch beetle (Anobium punctaum De Geer) and the Criocephalus rusticus, it was determined that the first of the above is the most resistant to microwave action. The effectiveness of combatting the Cerambycid in pine, spruce and fir w o od by means of microwaves is very similar (fig. 5) and the latter can be generally treated as coniferous w o o d (fig. 6 ). The greater the power of the microwave device, the shorter the time necessary to kill the insects in the wood (fig. 7 ). W ithdrawing the antenna from the wood surface causes a decline in the resistance to microwave action in insect control (fig. 8) due to the decreasing intensity of the scattered field. A rectilinear dependency was found of the mortality of Cerambycid larvae on the temperature of the wood subjected to microwave action (fig. 9 ). The average temperarure of the wood subjected to microwave action had to exceed 80° С for it to be possib'e to obtain a 100% effect in combatting Cerambycid larvae. In this publication a polemic is taken up with the views of the non-thermic killing of the insects by means of microwaves. Similarly to other radio waves of high and very high frequencies, microwaves destroy all stages of development of insects in the thermic manner. Unfortunately these waves, due to the heating up of the wood, can cause damages to the coats of paint, lacquer, polish and waxing, and can cause melting down of resin. Microwaves, in spite of some earlier information, damage gilding very strongly (fig. 1 0 ). It has not been confirmed, however, that wood subjected to microwave action in the presence of tw o -in ch steel nails burns. It was found that wood does burn without the presence of metal, when the shortest time of microwave action necessary for a 100% disinsectization of wood is exceeded. In the course of combatting insects, a relatively small area of w ood can be covered with an electromagnetic field each time. It is also necessary to pay great attention that the people operating the equipment and others not be within the emitted field. With the appropriate safety measures this danger can be avoided. The disinsectization method discussed should be limited to disinsectization of w o od withou t coatings, e.g. the wood of ceiling beams in brick or other houses or the wood of traditional folk architecture in museums in the open air. This, however, is a relatively labour-consuming (and therefore expensive) method, requiring specialized servicing and a strict observance of the technological regime.

Technologia spalania drewna o dużej wilgotności

100%

Kruczek S. , Kendra M. , Głąbik R.

Energetyka Cieplna i Zawodowa

2006

tom Nr 1

48--50

W artykule przedstawiono sposób spalania odpadów drzewnych o dużej wilgotności. Zaproponowano bezpośrednie spalanie odpadów w komorze wirowej, bez uprzedniego suszenia. Zaprojektowano w tym celu specjalną konstrukcję paleniska z recyrkulacją spalin z komory dopalania do komory wirowej. Dla realizacji powyższego przedsięwzięcia zastosowano strumienicę, dla której czynnikiem roboczym jest powietrze z otoczenia. Uzyskano w ten sposób możliwość spalania odpadów drzewnych o dużej wilgotności.

Wpływ wilgoci i wody na podstawowe własności drewna

72%

Krzysik F.

Ochrona Zabytków

1961

nr 1-2

50-65

Hybrydowa metoda pomiaru wilgotności drewna

72%

Ivakh R. , Dominyuk T.

tom Nr 38

29--31

W artykule dokonano analizy wpływu czynników zakłócających (temperatura, gęstość, szczelność, itp.) na wyniki pomiaru wilgotności drewna. W oparciu o dostępne analityczne zależności zawartości wilgoci w drewnie, zaproponowano jednoczesne stosowanie kilku metod dla pomiarów wilgotności drewna. W wypadku prawidłowego wyboru tych metod i racjonalnego dopasowania odpowiadających funkcji – w znacznym stopniu można zmniejszyć negatywny wpływ czynników zakłócających na wynik pomiaru wilgotności.

Established that to achieve high measurement accuracy and eliminate the effect of non-informative parameters (temperature, density, thickness of wood, etc.) during the measurement of wood moisture should be used hybrid methods, which are based on the combined search tool that meets specifications.

Zabezpieczanie konstrukcji drewnianych

58%

Fojutowski A.

Materiały Budowlane

2007

tom nr 2

52-55