16 research outputs found
Phytochemical s creening and a ntibacterial a ctivities of Tectona grandis L. f. (Teak) l eaves on m icroorganisms i solated from d ecayed f ood s amples
Bacteria were isolated from decayed food samples (tomatoes, cooked
beans
and rice)
collected from Afe Babalola University, Ado Ekiti (ABUAD) cafeteria
and characterized. Some of
these isolated microorganisms could pose serious har
m to humans including animals and they are
normally treated with commercial antibiotics. However, the
majority
of bacteria are resistant to
many
antibiotics
therefore, the use of plant extracts with therapeutic potential against resistant
bacteria is neces
sary. In this investigation,
eight bacteria were isolated from decayed food samples.
The bacterial isolates were identified as
Bacillus cereus
and
B. siamensis
from rice sample;
Klebsiella
oxytoxa
, Salimicrobium
halophilium
and
Norcardia
brasiliensis
from
beans sample;
Bacillus subtilis
,
Enterobacter taylore
, and
Brevibacillus agri
from tomatoes. The leaf samples of
Tectona grandis
were screened qualitatively and quantitatively for the phytochemicals while the
crude methanol and chloroform extracts were used as antimicrobial agents against the isolated
microorganisms. Alkaloids,
carotenoids
and tannins were present in large amount. T
he bacterial
isolates were more susceptible to commercial antibiotics than that of methanol extracts of
T.
grandis
.
The methanol extracts of
T. grandis
have a higher antimicrobial activity than the
chloroform ext
ract
Fundamental design strategies for advancing the development of high entropy alloys for thermo-mechanical application: A critical review
Nearly three decades since the discovery of high entropy alloys (HEAs), it has greeted a broad interest in the field of materials research as a better alternative to conventional alloy materials due to the exceptional combinatorial properties they offer in terms of lightweight, high-specific strength in elevated temperatures, excellent oxidation and corrosion resistance properties (among others). Leveraging on the âfour core effectsâ: high-entropy effect, sluggish/hysteretic diffusion effect, severe-lattice-distortion effect and cocktail effect which define the special features responsible for their outstanding properties, HEAs have been successfully employed for high-temperature applications in automobile and in the aerospace. An emerging sub-field of HEAs is the incorporation of a secondary strengthening phase that can be provided by the precipitation of intermetallic (IM) compounds to enhance the microstructure which will concomitantly affect the properties of a material (thermal, chemical and mechanical properties) for broader engineering applications. In this article, design concepts brewed from thermo-physical parameters calculation and computational thermodynamics using a CALPHAD-based tool were reviewed as fundamental design strategies in the development of IM-containing HEAs