359 research outputs found
Optimization of Extraction Process of Carob Bean Gum Purified from Carob Seeds by Response Surface Methodology
The carob product most widely used, especially for the food industry, is the carob bean gum (CBG), or locust bean gum (LBG). This gum comes from the endosperm of the seed and chemically is a polysaccharide, a galactomannan. It is used as thickener, stabilizer, emulsifier and gelling agent. Response surface methodology (RSM) was applied to optimize the extraction of CBG from Moroccan carob seeds. A central composite design was used for experimental design and analysis of the results searching for the optimal extraction conditions: Extraction temperature, extraction time and water to endosperm seeds ratio. Based on the RSM analysis, optimum conditions were: temperature 97°C, time 36 min and water to endosperm of seeds ratio of (197:1). Under the optimized conditions, the experimental values were in close agreement with values predicted by the model and for wish. Predicted yield of carob gum extracted is 69% of endosperm seeds. Keywords: Carob bean gum; Extraction; Central composite design; Optimization experiment
Magnetic Field Uniformity Across the GF 9-2 YSO, L1082C Dense Core, and GF 9 Filamentary Dark Cloud
The orientation of the magnetic field (B-field) in the filamentary dark cloud
GF 9 was traced from the periphery of the cloud into the L1082C dense core that
contains the low-mass, low-luminosity Class 0 young stellar object (YSO) GF 9-2
(IRAS 20503+6006). This was done using SOFIA HAWC+ dust thermal emission
polarimetry (TEP) at 216 um in combination with Mimir near-infrared background
starlight polarimetry (BSP) conducted at H-band (1.6 um) and K-band (2.2 um).
These observations were augmented with published I-band (0.77 um) BSP and
Planck 850 um TEP to probe B-field orientations with offset from the YSO in a
range spanning 6000 AU to 3 pc. No strong B-field orientation change with
offset was found, indicating remarkable uniformity of the B-field from the
cloud edge to the YSO environs. This finding disagrees with weak-field models
of cloud core and YSO formation. The continuity of inferred B-field
orientations for both TEP and BSP probes is strong evidence that both are
sampling a common B-field that uniformly threads the cloud, core, and YSO
region. Bayesian analysis of Gaia DR2 stars matched to the Mimir BSP stars
finds a distance to GF 9 of 270 +/- 10 pc. No strong wavelength dependence of
B-field orientation angle was found, contrary to previous claims.Comment: 18 pages, 6 figures ApJ, accepte
Phenotypic methods versus PCR-RFLP for the identification of dermatophyte species isolated from patients with dermatophytosis in Egypt
Background: Dermatophytes are major causative agents of cutaneous fungal infections worldwide. Identification of dermatophyte species is based on macroscopic and microscopic morphology on different culture media. Molecular methods such as PCR-RFLP are rapid, reliable and precise identification methods. This local study aimed to identify the spectrum of dermatophyte species among the studied patients population using different phenotypic and genotypic methods.Materials and methods: Hair, skin and nail specimens were collected from 135 patients with clinically suspected cases of dermatophytosis. All specimens were subjected to microscopic examination using KOH and culture on SDA and dermasel agar. Phenotypic identification was done by colony and microscopic morphology, and subculture on malt, PDA, lactrimel and urea agar plates. Molecular identification was done by PCR-RFLP using MvaI.Results: Out of 135 patients included in the study, 78 (57.8%) were positive by culture for dermatophytes. Five different species were identified, the most commonly isolated species was M. canis (51.3%) followed by T. violaceum (42.3%). PCR-RFLP correctly identified the isolated dermatophyte species, producing unique restriction patterns.Conclusion: Dermatophytosis is common in Egypt where humid hot climate and animal contact play important role in the spread of these fungi. The use of PCR-RFLP directly on clinical specimens rather than its use in the identification of dermatophytes from culture media is recommended.Keywords: Dermatophytosis, Dermasel agar, SDA, Sporulation media, PCR-RFL
Proper Motion of the Faint Star near KIC 8462852 (Boyajian's Star) - Not a Binary System
A faint star located 2 arcsec from KIC 8462852 was discovered in Keck 10 m
adaptive optics imaging in the near-infrared (NIR) in 2014 by Boyajian et
al. (2016). The closeness of the star to KIC 8462852 suggested the two could
constitute a binary, which might have implications for the cause of the
brightness dips seen by {\it Kepler} (Boyajian et al. (2016) and in
ground-based optical studies Boyajian et al. (2018). Here, NIR imaging in 2017
using the Mimir instrument resolved the pair and enabled measuring their
separation. The faint star had moved milliarcsec (mas) relative to
KIC 8462852 since 2014. The relative proper motion of the faint star is mas yr, for a tangential velocity of km s if
it is at the same 390 pc distance as KIC 8462852. Circular velocity at the 750
AU current projected separation is km s, hence the star pair
cannot be bound.Comment: 10 pages, 2 figure
Gamma radiation mediated green synthesis of gold nanoparticles using fermented soybean-garlic aqueous extract and their antimicrobial activity
Aspergillus oryzae was used to enhance the mobilization of antioxidants of soybean matrix along with garlic as a co-substrate by modulating polyphenolic substances during solid-state fermentation. Mobilized polyphenols were used as a green tool for synthesis and stabilization of gold nanoparticles (AuNPs). The radiation-induced AuNPs synthesis is a simple, clean and inexpensive process which involves radiolysis of aqueous solution that provides an efficient method to reduce metal ions. Gamma irradiated aqueous extract of fermented soybean and garlic was used for rapid preparation of AuNPs combining both effects of radiolytic reactions by radiation and stabilization by bioactive components of fermented extract. The synthesized AuNPs were confirmed by UV-Visible spectrophotometry, dynamic light scattering (DLS), Fourier Transform infra red (FT-IR) spectrophotometry, and transmission electron microscope (TEM) analysis which revealed morphology of spherical AuNPs with size ranging from 7–12 nm. The synthesized AuNPs exhibited antimicrobial activity against both Gram positive and Gram negative bacteria, as measured by well diffusion assay
Deformation Rate and Temperature Sensitivity in TWIP/TRIP VCrFeCoNi Multi-Principal Element Alloy
High-entropy alloys (HEAs) and medium-entropy alloys (MEAs), also sometimes referred to as multi-principal element alloys (MPEAs), present opportunities to develop new materials with outstanding mechanical properties. Through the careful selection of constituent elements along with optimized thermal processing for proper control of structure, grain size, and deformation mechanisms, many of the newly developed HEA systems exhibit superior strength and ductility levels across a wide range of temperatures, particularly at cryogenic deformation temperatures. Such a remarkable response has been attributed to the hardening capacity of many MPEAs that is achieved through the activation of deformation twinning. More recent compositions have considered phase transforming systems, which have the potential for enhanced strengthening and therefore high strength and ductility levels. However, the strain rate sensitivity of such transforming MPEAs is not well understood and requires further investigation. In this study, the tensile properties of the non-equiatomic V10Cr10Fe45Co30Ni5 MPEA were investigated at different deformation rates and temperatures ranging from 77 K (-196 degrees C) to 573 K (300 degrees C). Depending on the deformation temperature, the considered MPEA exhibits plasticity through either crystallographic slip, deformation twinning, or solid-state phase transformation. At 300 degrees C, only slip-mediated plasticity was observed for all the considered deformation rates. Deformation twinning was detected in samples deformed at room temperature, while face-centered cubic to body-centered cubic phase transformation became more favorable at cryogenic deformation temperatures. The trends are nonlinear with twinning-induced plasticity (TWIP) favored at the intermediate deformation rate, while transformation-induced plasticity (TRIP) was observed, although limited, only at the slowest deformation rate. For all the considered deformation rates at cryogenic deformation temperature, a significant TRIP activity was always detected. The extent of TRIP, however, was dependent on the deformation rate. Increasing the deformation rate is not conducive to TRIP and thus hinders the hardening capacity
Syrup of natural carob sugars and a process for its production using Response Surface Methodology
Experimental design was used to investigate the effect of three parameters (extraction temperature, extraction time and ratio of water to pulp) on syrups yields. The ranges of the factors investigated were 20–45°C for extraction temperature (X1), 1–3h for extraction time (X2) and 1–3 for extraction ratio of water to pulp (X3). The extracting parameters for syrups yields were optimized by using three-factor-three-level Box Behnken design (BBD) and response surface methodology based on the single-factor experiments. As results, the optimum conditions were extracting temperature 43.45°C, extracting time 2.40 h and the ratio of extraction solvent (water) to pulp (v/w) 2.27. Under these conditions, the experimental values were in close agreement with values predicted by the model and for wish. Predicted yield of syrup extracted is 39.51 %. Keywords: Carob pods; pulp; Syrup yield; Optimization experiment; Box Behnken design.
ENHANCEMENT OF PLANT GROWTH, CHEMICAL COMPOSITION AND SECONDARY METABOLITES OF ESSENTIAL OIL OF SALT-STRESSED CORIANDER (CORIANDRUM SATIVUM L.) PLANTS USING SELENIUM, NANO-SELENIUM, AND GLYCINE BETAINE
Two pot experiments were carried out under greenhouse conditions during the two successive winter seasons of 2017/2018 and 2018/2019 to enhance the performance of coriander (Coriandrum sativum L.) plants under salt stress conditions (NaCl at 0, 25, 50 and 75 mM). Along with the possibility of enhancing the plant growth, chemical composition, and secondary metabolites of essential oils. Foliar applications of selenium (25 and 50 ppm), nano selenium (25 and 50 ppm), glycine betaine (5 and 10 mM), and distilled water (control treatment) were applied on C. sativum plants. The foliage and root growth, chemical composition, and secondary metabolites of essential oils of coriander plants grown under salt stress were examined. The obtained results of the two seasons revealed that salt stress had significant deleterious effects on vegetative growth, fruit yield, essential oil yield, secondary components, and leaves chemical composition, while it enhanced the electrolyte leakage, proline content, Na+ and Cl- of the leaves. Generally, the tested treatments: selenium, nano selenium, and glycine betaine varied in their significant effects on the studied characters. Selenium and glycine betaine treatments were more effective in improving coriander plants to salinity stress where they significantly increased almost all the studied parameters under saline compared to the control
Rheological Quality and Influence Factor of Moroccan Prickly Pear Juice (Opuntia ficus indica L.)
Rheological properties of prickly pear juice fruit of cactus (Opuntia ficus indica) and impacts of temperature, shearing rate and pH value on its viscosity were studied using a rotational concentric cylinders viscometer. The results show that the viscosity of prickly pear juice decreases with the increase of its temperature and shearing rate. The solution presents pseudo-plasticity fluid, which shows the characters of shear thinning as follows: first, its viscosity decreases gradually as the temperature increases. The viscosity decreases sharply at both acid and alkaline conditions, indicating that it is influenced apparently by pH value. Keywords: Prickly Pear, Juice, temperature, shearing rate, pH, Viscosity
- …