γ-Irradiation Dose: Effects on Baby-Leaf Spinach Ascorbic Acid, Carotenoids, Folate, α-Tocopherol, and Phylloquinone Concentrations

2010 ◽  
Vol 58 (8) ◽  
pp. 4901-4906 ◽  
Author(s):  
Gene E. Lester ◽  
Guy J. Hallman ◽  
Juliana A. Pérez
Keyword(s):  
Ascorbic Acid ◽  
Irradiation Dose ◽  
Γ Irradiation ◽  
Dose Effects

4-o-methyl-d-glucurono-d-xylan degradation by γ-irradiation. Part 1 — Dose effects on the macromolecular properties

1991 ◽  
Vol 15 (3) ◽  
pp. 255-263 ◽  
Author(s):  
A EBRINGEROVA ◽  
T EREMEEVA ◽  
O KHINOVEROVA ◽  
B ERSHOV
Keyword(s):  
Γ Irradiation ◽  
Xylan Degradation ◽  
Dose Effects

scholarly journals Chemical and Physical Properties of Cassava Starch–CM-Chitosan–Acrylic Acid Gel Copolymerization by Gamma Irradiation

2014 ◽  
Vol 14 (1) ◽  
pp. 37-42
Author(s):  
Gatot Trimulyadi Rekso
Keyword(s):  
Acrylic Acid ◽  
Irradiation Dose ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Γ Irradiation ◽  
Equilibrium Degree ◽  
Preparation Conditions ◽  
Gel Fraction ◽  
Gelatinized Starch ◽  
Acid Gel

Starch is a renewable natural polymer that can be decomposed easily in the environment and can be modified to various applications such as biomedical, agricultural and pharmaceutical applications. Copolymerization of gelatinized starch–CM-chitosan and acrylic acid (AAc) in aqueous medium using γ-irradiation was carried out. The preparation conditions, such as irradiation dose and AAc concentration were investigated. The copolymers were characterized by FTIR spectroscopy, thermo-gravimetric analysis (TGA) and scanning electron microscopy (SEM). The results show that by increasing of irradiation dose the gel fraction increases till the dose of 15 kGy. Above the stating dose the gel fraction decreases. The Equilibrium Degree of Swelling (EDS) value slightly increases with increasing irradiation dose and after dose of 15 kGy is decreasing. The swelling of starch–CM-chitosan–AAc hydro gels reduced as the gel content increases. The results indicated that the optimum condition for obtaining hydro gels with desirable properties was irradiated at dose of 15 kGy. The results indicated that SEM revealed that the higher the dose, the lower the copolymer pore size. The starch–CM-chitosan–AAc copolymers have thermal stability higher than that for starch individually.

Positron Lifetimes and Crystallinity of γ-Irradiated Polypropylenes

2012 ◽  
Vol 733 ◽  
pp. 163-166
Author(s):  
Zhe Chen ◽  
Wei Huang ◽  
Peng Fei Fang ◽  
Wen Yu ◽  
Shao Jie Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Irradiation Dose ◽  
Gamma Ray ◽  
Positron Lifetime ◽  
Γ Irradiation ◽  
Scanning Calorimetry ◽  
Γ Ray ◽  
Positron Lifetimes ◽  
Dsc Method ◽  
Low Irradiation

The microstructure of the polypropylenes (PP) irradiated by gamma ray was studied by positron lifetime technique and differential scanning calorimetry (DSC). Lifetime measurement shows o-Ps intensity decreases with increasing γ irradiation dose. The crystallinity of irradiated samples was detected by DSC method. The correlation between o-Ps intensity and crystallinity indicates γ-ray can induce higher crystallinity in the polypropylene at low irradiation dose.

Effect of Buffer on the Optical Properties of Irradiated Hydroxyethyl Methacrylate Copolymer

2002 ◽  
Vol 17 (5) ◽  
pp. 1199-1207
Author(s):  
K. F. Chou ◽  
C. C. Han ◽  
Sanboh Lee
Keyword(s):  
Optical Properties ◽  
Irradiation Dose ◽  
Ph Value ◽  
Bathochromic Shift ◽  
Cutoff Wavelength ◽  
Hydroxyethyl Methacrylate ◽  
Γ Irradiation ◽  
Incident Wavelength ◽  
Γ Ray ◽  
Methacrylate Copolymer

The effect of buffer and γ irradiation on the optical properties of hydroxyethyl methacrylate (HEMA) copolymer was investigated. The transmission of HEMA copolymer decreased with the increase of irradiation dose and/or pH value of the buffer. The cutoff wavelength of HEMA copolymer exhibits a bathochromic shift as the γ-ray dose and/or pH value of buffer increases. The influence of atmosphere during γ-ray irradiation on the optical properties of HEMA copolymer was investigated. The change of optical properties of HEMA copolymer irradiated in air was more pronounced than that irradiated in vacuum. Light was scattered by holes in the polymer. The relationship between scattering intensity (Is) and incident wavelength (λ) can be described by the formula Is ∝ λ−n. The span of holes increases with the irradiation dose regardless of radiation atmosphere and pH value in the range of 4.1–6.5. A boundary between the inner and outer layers of HEMA copolymer irradiated in air was observed, separating two differential morphologies of holes.

Effect of Irradiation on the Molecular Weight, Structure and Apparent Viscosity of Xanthan Gum in Aqueous Solution

2011 ◽  
Vol 239-242 ◽  
pp. 2632-2637 ◽  
Author(s):  
Yan Jie Li ◽  
Yi Ming Ha ◽  
Feng Wang ◽  
Yong Fu Li
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Apparent Viscosity ◽  
Irradiation Dose ◽  
Xanthan Gum ◽  
Gel Permeation Chromatography ◽  
Uv Spectra ◽  
X Ray Diffraction ◽  
Γ Irradiation ◽  
Radiation Chemical

Xanthan gum samples were irradiated in aqueous solution at different doses (0-120 kGy) of 60Co γ-rays. The changes of molecular weight and structures of irradiated xanthan gum samples were investigated and characterized by using gel permeation chromatography(GPC), X-ray diffraction (XRD), fourier-transform infrared spectra (FTIR), ultraviolet–visible spectral (UV–vis) analysis and rheometer. Results showed the molecular weight decreased gradually with increasing irradiation dose. The radiation chemical yields G(d) of xanthan gum was 26.55. FTIR spectra and XRD indicated that γ-irradiation introduced no significant changes into the structure and crystal texture, but UV spectra showed a distinct absorption peak at about 265 nm, increasing with irradiation dose, which was attributed to the formation of carbonyl groups or double bond. Apparent viscosity of xanthan gum solution decreased with increasing irradiation dose and remain basically constant with the prolonging of shear time after irradiation.

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