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2021 ◽  
Vol 88 ◽  
pp. 61-70
Author(s):  
Alex Wcislo ◽  
Xavier Graham ◽  
Stan Stephens ◽  
Johannes Ehoulé Toppe ◽  
Lucas Wcislo ◽  
...  

Some Azteca ants are well-known symbionts that defend their Cecropia host plants against herbivory, although there is considerable variability in behavior among colonies, conditions, and species. In exchange, ants receive food, and also shelter within the plants’ internodes. Here we demonstrate that ants repair damage to the host plant when their brood is directly threatened. Using comminuted plant fibers and an unidentified binding liquid (probably plant sap) ants generally began patching holes in the tree trunk immediately, and significantly reduced the size of the hole 2.5 hours after it was created, and they generally completed the repairs within 24 hours.


PANALUNGTIK ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 61-74
Author(s):  
Ria Intani T ◽  
Lasmiyati Lasmiyati

As of today, quinine plants are still found in the Bukit Unggul Plantation, Bandung Regency, which is part of PT Perkebunan Nusantara VIII. Quinine is processed in the processing plant located in Bukit Unggul. In general, people have known quinine as an anti-malarial drug in which the ingredients were taken from the bark of the quinine tree trunk, afterward it becomes waste. In the past, quinine waste was used as firewood and building material for offices, factories, and homes for plantation worker. In its development, there were those who use quinine waste to make furniture to meet their own needs. The results showed that the previous idea of using quinine waste inspired people in the future to utilize and develop quinine waste into furniture, in a sense of worth-selling furniture. The purpose of this study is to demonstrate the utilization of quinine waste in the past and its development. This is descriptive research with a qualitative approach. The data collection was carried out using interview, observation, and documentation studies. The conclusion of the study is that the discourse about quinine became widespread, not only limited to medicine, but also building materials and crafts.


Acarologia ◽  
2021 ◽  
Vol 61 (4) ◽  
pp. 967-977
Author(s):  
Farid Faraji ◽  
Mohsen Zare ◽  
Hasan Rahmani

A new genus and species of digamasellid mites is described based on adult females and males. Bulbolaelaps bossei n. gen., n. sp. was collected from the fruiting bodies of gilled fungi on a tree trunk in Zanjan province, Iran. The new genus can be distinguished from the other genera of Digamasellidae by having a bulbous swollen protuberance on the venter of the palptrochanter; corniculi weakly formed and epistome weakly sclerotised; hypostomal setae h1 and h2 positioned more or less transversely; deutosternal groove narrow with limited number of denticles; ventral base of female cheliceral digit with a spine-like projection; and setae ad1 and pd1 tarsi II–IV narrowly lanceolate apically.


Author(s):  
Kathrin Kühnhammer ◽  
Adrian Dahlmann ◽  
Alberto Iraheta ◽  
Malkin Gerchow ◽  
Christian Birkel ◽  
...  

Author(s):  
Nikhil Kumar Singh ◽  
Jyoti Yadav

A beam bridge is a bridge that uses struts as a method of supporting the deck. A bridge consists of three sections: the foundation consisting of protrusions and supports and the substructure consisting of protrusions and quay and the superstructure (bracing, cantilever or curve) and the deck. A beam bridge is probably the most manufactured and used bridge on the planet. Its basic plant, at its best, can be likened to a tree trunk extending to one side to alternate across a stream or river. All decks consist of two main parts: the substructure and the superstructure. The superstructure is everything from the support cushions to - it's the thing that supports the posts and it's the most distinctive part of the deck. The substructure is the device that exchanges the poles of the superstructure on the ground. The two sections must work together to form a strong and durable bridge. Prestressed concrete is basically concrete where the internal concern is reasonable and the pressure propagation created by the external load is concentrated to the desired extent. In this research, we analyze a beam bridge with the effect of prestressed concrete and compare it to a generic deck bridge. Regarding the finite element analysis, the analysis of forces and costs. Here it is concluded that the implementation of a prestressed ceiling results in an economical, stable and load-resistant element.


2021 ◽  
Author(s):  
Aleksey Platonov ◽  
A. Popov ◽  
Svetlana Snegireva ◽  
Ekaterina Kantieva

Fires have a significant impact on the structure and physical and mechanical properties of wood. The degree of this effect depends on the type of fire, its intensity and the duration of exposure to high temperature. The greatest impact on the wood occurs with a strong grassroots and general top fire. Gorenje fire is characterized by a high intensity of burning of forest floor and undergrowth, as well as the crown of trees. The effect of the high temperature of the fire on the tree trunk is different. As a result of the destruction of wood, there is a partial blocking of hydroxyl groups in the cellulose molecules and leads to a decrease in the hygroscopicity limit of wood. Of great practical interest is the change in the hygroscopicity of wood damaged by fire. The aim of this study is to determine the changes in the hygroscopicity of the core wood of Scots pine (Pinus sylvestris L.)after damage by a strong grassroots and general high-level fire. The studies were carried out on wood growing on the territory of the UOL in the Voronezh region, on samples of pine core wood cut from the clump, middle and apex parts of the trunk. It was experimentally established that the greatest decrease in the hygroscopicity of pine core wood occurred in the left part of the trunk, and the smallest in the middle part, after fire damage.


Author(s):  
Danilo Samuel Jodas ◽  
Sergio Brazolin ◽  
Takashi Yojo ◽  
Reinaldo Araujo de Lima ◽  
Giuliana Del Nero Velasco ◽  
...  
Keyword(s):  

2021 ◽  
Vol 875 (1) ◽  
pp. 012016
Author(s):  
E Kantieva ◽  
S Snegireva ◽  
A Platonov

Abstract Wood is a material with unique properties that contribute to its wide use as a raw material for various types of industries. Different quality requirements are imposed on the raw materialdepending on the material or wood product. However, physical and mechanical properties of wood are not homogenousalong the radius and height of the trunk and depend on the species, location in the trunk and growing conditions. The aim of this research is to study the variability of porosity and density of Scots pine (Pinus sylvestris L.) wood in a tree trunk growing in dry forests of the forest-steppe zone of the Russian Federation. The studies were carried out on wood cuts, sawn at different trunk heights. The change in the density of pine wood along the height of the trunk by 1.43% for each meter has been established. The wood porosity increases from the butt to the top by an average of 5.5%. New information about the variability of wood properties makes it possible to rationally and reasonably approach the choice of raw materials for obtaining materials with specified performance characteristics.


2021 ◽  
Author(s):  
Lilong Zou ◽  
Livia Lantini ◽  
Fabio Tosti ◽  
Amir M. Alani
Keyword(s):  

2021 ◽  
pp. 1302-1309
Author(s):  
Eusébio Conceição ◽  
João Gomes ◽  
Mª Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Viegas ◽  
...  

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