Role of mineral admixtures in self compacting concrete: Scanning electron microscopy approach

2021 ◽  
Author(s):  
Layth A. Al-Jaberi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mineral Admixtures ◽  
Self Compacting Concrete ◽  
Scanning Electron

The use of scanning electron microscopy in interpreting chenopodium remains from three archaeological sites in northwestern Iowa

1992 ◽  
Vol 50 (2) ◽  
pp. 1112-1113
Author(s):  
Douglas William Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Archaeological Sites ◽  
Late Prehistoric ◽  
Eastern United States ◽  
Chenopodium Berlandieri ◽  
Seed Identification ◽  
Level 2 ◽  
Scanning Electron

Within the past 20 years, archaeobotanical research in the Eastern United States has documented an early agricultural complex before the dominance of the Mesoamerican domesticates (corn, beans, and squash) in late prehistoric and historic agricultural systems. This early agricultural complex consisted of domesticated plants such as Iva annua var.macrocarpa (Sumpweed or Marshelder), Hellanthus annuus (Sunflower) and Chenopodium berlandieri, (Goosefoot or Lasbsquarters), and heavily utilized plants such as Polygonum erectum (Erect Knotweed), Phalaris caroliniana (May grass), and Hordeum pusillum (Little Barley).Recent research involving the use of Scanning Electron Microscopy (SEM) specifically on Chenopodium has established diagnostic traits of wild and domesticated species seeds. This is important because carbonized or uncarbonized seeds are the most commonly recovered Chenopodium material from archaeological sites. The diagnostic seed traits assist archaeobotanists in identification of Chenopodium remains and provide a basis for evaluation of Chenopodium utilization in a culture's subsistence patterns. With the aid of SEM, an analysis of Chenopodium remains from three Late Prehistoric sites in Northwest Iowa (Blood Run [Oneota culture], Brewster [Mill Creek culture], and Chan-Ya-Ta [Mill Creek culture]) has been conducted to: 1) attempt seed identification to a species level, 2) evaluate the traits of the seeds for classification as either wild or domesticated, and 3) evaluate the role of Chenopodium utilization in both the Oneota and Mill Creek cultures.

Effect of Zn on the intermetallics formation and reliability of Sn-3.5Ag solder on a Cu pad

2007 ◽  
Vol 22 (7) ◽  
pp. 1879-1887 ◽  
Author(s):  
Y.K. Jee ◽  
Y.H. Ko ◽  
Jin Yu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Isothermal Aging ◽  
X Ray Diffraction ◽  
X Ray ◽  
Drop Tests ◽  
Joint Microstructures ◽  
Role Of Zn ◽  
Scanning Electron

Varying amounts of Zn (1, 3, and 7 wt%) were added to Sn–3.5Ag solder on a Cu pad, and the resultant solder joint microstructures after a reflow and isothermal aging (150 °C, up to 500 h) were investigated using scanning electron microscopy, energy dispersive x-ray, and x-ray diffraction, which were subsequently correlated to the results of microhardness and drop tests. Zinc was effective in improving the drop resistance of Sn–3.5Ag solder on the Cu pad, and an addition of 3 wt% Zn nearly doubled the number of drops-to-failure (Nf). The beneficial role of Zn was ascribed to suppression of Cu6Sn5 and precipitation of Zn-containing intermetallic compounds (IMCs). However, the Zn effect was reduced as Cu6Sn5 and Ag3Sn precipitated in a joint IMC layer after prolonged aging. The interface between Ag5Zn8 and Cu5Zn8 was resistant to drop impact, but two other layered IMC structures of Cu6Sn5/Cu3Sn and Cu5Zn8/Cu6Sn5 were not.

scholarly journals Fine Structure of Maxillary Palps in Adults of Hermetia illucens (Diptera: Stratiomyidae)

2020 ◽  
Author(s):  
M Pezzi ◽  
C Scapoli ◽  
M Bharti ◽  
M J Faucheux ◽  
M Chicca ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sexual Dimorphism ◽  
Hermetia Illucens ◽  
The Family ◽  
Sensory Structures ◽  
First Time ◽  
Maxillary Palps ◽  
Scanning Electron

Abstract A relevant species in waste management but also in forensic, medical, and veterinary sciences is the black soldier fly, Hermetia illucens (Linnaeus; Diptera: Stratiomyidae). An ultrastructural study by scanning electron microscopy (SEM) was conducted for the first time on maxillary palps of both sexes, describing in detail the morphology and distribution of sensilla and microtrichia. The maxillary palps, composed of two segments, show sexual dimorphism in length and shape. In both sexes, the first segment is covered only by microtrichia, but the second one is divided into two parts: the proximal one, covered only by microtrichia, and the distal one containing both microtrichia and sensory structures. These structures include two types of sensory pits and one of chaetic sensilla. Due to sexual dimorphism in palp size, females have a higher number of sensory pits. The sexual dimorphism of palps and the presence and role of sensilla in H. illucens was discussed in comparison to other species of the family Stratiomyidae and of other Diptera. This study may represent a base for further investigations on mouthpart structures of this species, involved in key physiological activities, such as feeding, mating and oviposition.

A novel method for assessing the role of iron and its functional chelation in fibrin fibril formation: the use of scanning electron microscopy

2013 ◽  
Vol 23 (5) ◽  
pp. 352-359 ◽  
Author(s):  
Etheresia Pretorius ◽  
Natasha Vermeulen ◽  
Janette Bester ◽  
Boguslaw Lipinski ◽  
Douglas B. Kell
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fibril Formation ◽  
Novel Method ◽  
Scanning Electron
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