In this paper silver nanoparticles (NPs) which are synthesized by a simple plasma arc discharge method, that is a kind of electrochemical methods, are examined. The method is very simple and silver NPs are obtained very fast by means of two polished silver plates and electrochemical cell. The effects of changing some terms of the experiment including using Hydrogen peroxide (H2O2), temperature and the medium of experiment on oxygen percent and crystalline structure of silver NPs have been studied by transmission electron microscopy, UV-visible spectrophotometery, and X-ray diffraction. Water medium gets larger nanoparticles with less oxygen content compare to air medium. The size of synthesized nanoparticles become smaller and they also become more spherical by using H2O2 in air medium. In water medium, the size and concentration of the silver crystallite increase by temperature growth and adding H2O2 respectively.
Attempts were made in the present study to design and develop skeletally modified ether linked tetraglycidyl epoxy resin (TGBAPSB), which is subsequently reinforced with different weight percentages of amine functionalized mullite fiber (F-MF). The F-MF was synthesized by reacting mullite fiber with 3-aminopropyltriethoxysilane (APTES) as coupling agent and the F-MF structure was confirmed by FT-IR. TGBAPSB reinforced with F-MF formulation was cured with 4,4’-diamino diphenyl methane (DDM) to obtain nanocomposite. The surface morphology of TGBAPSB-F-MF epoxy nanocomposites was investigated by XRD, SEM and AFM studies. From the study, it follows that these nanocomposite materials offer enhancement in mechanical, thermal, thermo-mechanical, dielectric properties compared to neat (TGBAPSB) epoxy matrix. Hence we recommend these nanocomposites for a possible use in advanced engineering applications that require both toughness and stiffness.
Antioxidants are derivatives of vitamin C or beta-carotene that prevent reactions stimulated by oxygen, peroxides, or free radicals, thus reducing the oxidative stress. They have found their way into many uses in treating several human diseases and reducing the risk of developing diseases like cancer. In view of this property, the present study was focussed in identifying several plants possessing antioxidative properties and which were also conserved in the ex-situ park of CSIR – Central Institute of Mining and Fuel Research, Dhanbad, India. Fifteen medicinal plants including herbs, shrubs and grasses are reported in this paper, and a collective insight has been presented about their antioxidant properties and the present state of their pharmacological applications. The specific chemical constituents abundant in the leaves, roots, stems, seeds and fruits of each of these plants have also been dealt with. To report a few antioxidant pharmacological preparations from Ayurvedic literature are Vimang, Maharishi Amrit Kalash (MAK4, MAK5), Maharishi Ayurved (MA631, MA47), MA Raja’s Cup, MA Student Rasayana and MA Ladies Rasayana. This review has been attempted to enhance the importance of the plants which are generally being neglected, so that it can used by the local people in rural areas for their cultivation and it will also pave the pathway for their subsequent future use in medicinal and research industry for drug formulation.
ZrO2 thin film samples were produced by the sol-gel dip coating method. Four different absorbed dose levels (such as ~ 0.4, 0.7, 1.2 and 2.7 Gray-Gy) were applied to ZrO2 thin films. Hence, the absorbed dose of ZrO2 thin film was examined as physical dose quantity representing the mean energy imparted to the thin film per unit mass by gamma radiation. Modification of the grain size was performed sensitively by the application of the absorbed dose to the ZrO2 thin film. Therefore the grain size reached from ~50 nm to 87 nm at the irradiated ZrO2 thin film. The relationship of the grain size, the contact angle, and the refractive index of the irradiated ZrO2 thin film was investigated as being an important technical concern. The irradiation process was performed in a hot cell by using a certified solid gamma ray source with 0.018021 Ci as an alternative technique to minimize the utilization of extra toxicological chemical solution. Antireflection and hydrophilic properties of the irradiated ZrO2 thin film were slightly improved by the modification of the grain size. The details on the optical and structural properties of the ZrO2 thin film were examined to obtain the optimum high refractive index, self-cleaning and anti-reflective properties.
Cucumber Variety ‘Drite L108’ (Cucumis sativus L. Cv. Derit L108) was selected as the test material. In the solar greenhouse, different days (1, 3, 5, 7, 9 d) of light (PAR < 200 µmol·m-2·s-1) and normal light conditions were designed with shading nets to observe the growth indexes of cucumber plants and the changes of antioxidant enzyme activities in leaves. The results showed that: (1) continuous low light increased the SPAD (relative chlorophyll) value of cucumber leaves and decreased the net photosynthetic rate. The longer the continuous low light days are, the smaller the net photosynthetic rate of cucumber leaves and the worse the photosynthetic recovery ability would be. (2) The plant height, stem diameter and leaf area per plant were lower than CK, and the above indexes could not return to the normal level after 9 days of normal light recovery; the yield and marketability of cucumber fruit decreased under continuous low illumination. (3) The activities of SOD (superoxide dismutase) and POD (peroxidase) in cucumber leaves increased, the activities of CAT (catalase) first increased and then decreased, and the content of MDA (malondialdehyde) continued to increase. The longer the days of continuous light keep, the more seriously the cucumber leaves were damaged by membrane lipid peroxidation. After continuous light for more than 7 days, the metabolic function of cucumber leaves was difficult to recover to the normal level.
One functional class is described in terms of one-sided modulus of continuity and the modulus of positive (negative) variation on which there
is a uniform convergence of the truncated cardinal Whittaker functions.
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