scholarly journals Diversity of the floral nectaries surface of four Crataegus L. species

2012 ◽  
Vol 59 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Mirosława Chwil ◽  
Agata Konarska ◽  
Elżbieta Weryszko-Chmielewska

The performed studies focused on the surface structure of floral nectaries of four species from the following genus: <i>C. coccinea</i> L. , <i>C. crus-galli</i> L., <i>C. curvisepala</i> Lindm and <i>C. prunifolia</i> (Poiret) Pers. The observations of the epidermis area were made in a scanning electron microscope (SEM). A nectary appears to be shaped like a slightly curved disk situated between the pistil style and the basal part of the stamens filaments. The nectary area of the studied species differed substantially as regards the cuticle sculpture and stomata number. The nectary secretion in <i>Crataegus</i> flowers proceeds through the stomata located below a level of the other epidermis cells, in the deep indents of the secretory tissue. The highest stomata number in 1 mm<sup>2</sup> nectary epidermis was recorded in <i>C. crus-galli</i>, <i>C. coccinea</i>, <i>C. prunifolia</i> and finally, <i>C. curvisepala</i>. Analyzing the nectary cuticular structure in respect of its increasing complexity (absence or presence of stripes), the investigated taxons can be ordered as following: <i>Crataegus curvisepala</i>, <i>C. coccinea</i>, <i>C. crus-galli</i> and <i>C. prunifolia</i>.

Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


1993 ◽  
Vol 12 (2) ◽  
pp. 154-154
Author(s):  
Stephen Tatman

Abstract. The preparation of microfossil specimens for study with the scanning electron microscope involves the transfer of material from slides to stubs. Specimens must then be oriented and mounted securely. To do this accurately the slide and stub should both be viewed through a stereomicroscope. However due to differences in shape and height, both surfaces are not usually in the plane of focus at the same time. Many micropalaeontologists routinely use small boxes or sample tube lids to hold the stub and refocus before finally mounting the specimens. The risk of dropping specimens is reduced by using a single carrier, securely holding both the slide and stub. The design illustrated below (fig.1) was developed from a prototype constructed from cardboard and plastic. The metal unit can easily be made in a workshop at a very low cost or cardboard versions made in the laboratory.The stage is based on the principle that both slide and stub should be held securely, close together and in the same plane of focus. The slide holders should be secure but not too tight otherwise the stub may be jarred as slides are changed. The number of slides which can be held on one unit may be varied. The presence of two holders has proved useful, any more could make the unit cumbersome. If the microscope to be used does not have a wide stage then it may prove more practical to have only one holder.The stub holders allow the stub to be clamped to . . .


2019 ◽  
Vol 2 (1) ◽  
pp. 9-13
Author(s):  
Ni Made Dwidiani ◽  
Putu Wijaya Sunu ◽  
Gusti Ngurah Nitya Santhiarsa

This work studies the use of red chilli tree (capsicum anuumm L) waste as material of activated carbon and examines the morphological structure and elemental composition of the activated chili trees. The morphological structure was measured at TekMIRA (Pusat Penelitian dan Pengembangan Teknologi Mineral dan Batubara, Bandung) by using the scanning electron microscope (SEM), and the composition of the elements of carbon, hydrogen, nitrogen and ash is determined by the ultimate testing analysis with the ASTM D5373 standard. In the testing procedure, activated carbon is made from red chili tree waste by dehydration with a temperature of 2000 C for 1 hour and carbonized with a temperature of 3750 C for 1 hour. Then, the chemical activation (NaOH) is made in variation of concentration of 1%, 3%, and 5% with soaked time 24 hours, and dried at 2000 C for one hour. The carbonization at a concentration of 1% (NaOH) gave the best result on activated carbon from red chili trees.


2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.


Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.


Phytotaxa ◽  
2018 ◽  
Vol 373 (3) ◽  
pp. 169 ◽  
Author(s):  
YUE CAO ◽  
PAN YU ◽  
QINGMIN YOU ◽  
REX L. LOWE ◽  
DAVID M. WILLIAMS ◽  
...  

A new species of Tabularia, Tabularia sinensis, is described from the inland Poyang Lake (Jiangxi Province), the largest lake in China. The description is based on light and scanning electron microscope observations of valve and girdle elements. Given the diversity of forms in the genus, the relationships and status of the genus was investigated in the context of the other known species in the genus and to ascertain if Tabularia, as originally circumscribed, remains monophyletic.


1973 ◽  
Vol 19 (3) ◽  
pp. 392-393 ◽  
Author(s):  
Michael Corlett

Observations with the scanning electron microscope reveal tuberculate prominences up to 0.75 to 1.0 μ high and 0.5 μ wide on the suface of the conidium. The prominences are 1.0 to 1.5 μ apart and in the mature conidia have flattened cap-like tops. The swollen tips of the conidiophores are finely warted.


1969 ◽  
Vol 7 (3) ◽  
pp. 270-272 ◽  
Author(s):  
Y. Ito ◽  
Y. Nozawa ◽  
H. Suzuki ◽  
T. Setoguti

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