•Green synthesis of silver nanoparticles using polysaccharides extracted from marine macroalgae.•The diameter range of the formed Ag-NPs depends on the algal species used.•The resultant Ag-NPs were ...applied to cotton fabrics with/without citric acid or a binder.•The treated fabrics showed excellent antibacterial activity.•The activity depends on type of the fabric treatment, size of the Ag-NPs and the algal species used.
Green synthesis of nanoparticles that have environmentally acceptable solvent systems and eco-friendly reducing agents is of great importance. The aim of this work was to synthesis of silver nanoparticles (AgNPs) using water soluble polysaccharides extracted from four marine macro-algae, namely, Pterocladia capillacae (Pc), Jania rubins (Jr), Ulva faciata (Uf), and Colpmenia sinusa (Cs) as reducing agents for silver ions as well as stabilizing agents for the synthesized AgNPs. The formed Ag-NPs have been confirmed by UV–Vis spectroscopy, FTIR analysis and TEM. The resultant Ag-NPs colloidal solutions were applied to cotton fabrics in presence and absence of citric acid (CA) or a binder (B). The antimicrobial activity of the treated fabrics was evaluated. The results revealed that the antimicrobial activity depends on type of the fabric treatment, size of the synthesized Ag-NPs and the algal species used for polysaccharides extraction.
This paper presents a literature review of the application of cement, lime and polymer emulsion in road construction. The focus is mainly on the soil candidates, binding mechanism, the reported ...strengths and weaknesses for each chemical stabiliser used in soil stabilisation. While it is generally agreed that cement is best suited for sand-sized to gravel-sized soil mixtures (well-graded), lime is mainly used for wet heavy-clay soil mixtures. Polymer emulsion is more suitable for silt-sized to fine gravel-sized soil mixtures (well-graded). Organic soils are the most difficult soil type to stabilise, and for any kind of chemical stabiliser used, the strength gain is relatively minimal. Cement undergoes hydration reaction which is rapid, and results in high compressive strength, while lime undergoes a slower pozzolanic reaction is slower, and provide lower compressive strength. Polymer emulsion depends on the rate of evaporation for the film formation to complete, and results in ductile polymer-soil matrix. Like lime, polymer does not provide significant compressive strength but does provide great flexural strength that prevents crack propagations. The outcomes from this paper provide an insight into recent and upcoming research trend using chemical soil stabilisers on local soil mixtures to improve the engineering properties of pavement layers made of these soil mixtures.
This report provides the first description of the myco-synthesis of rod-shaped MnO NPs with an average crystallite size of ~ 35 nm, employing extracellular bioactive metabolites of endophytic ...Trichoderma virens strain EG92 as capping/reducing agents and MnCl
·4H
O as a parent component. The wheat bran medium was chosen to grow endophytic strain EG92, which produced a variety of bioactive metabolites in extracellular fraction, which increases the yield of MnO NPs to 9.53 g/l. The whole medium and fungal growth conditions that influenced biomass generation were optimized as successive statistical optimization approaches (Plackett-Burman and Box-Behnken designs). The production improvements were achieved at pH 5.5, WBE (35%), and inoculum size (10%), which increased X
to twelve-folds (89.63 g/l); thereby, P
increased to eight-folds (82.93 g/l). After 162 h, X
(145.63 g/l) and P
(99.52 g/l) on the side of µ
and Y
were determined as 0.084 and 7.65, respectively. Via Taguchi experimental design, fungus-fabricated MnO NPs reaction was improved by adding 0.25 M of MnCl
·4H
O to 100% of fungal extract (reducing/capping agents) and adjusting the reaction pH adjusted to ~ 5. This reaction was incubated at 60 °C for 5 h before adding 20% fungal extract (stabilizing agent). Also, P
was raised 40-fold (395.36 g/l) over the BC. Our myco-synthesized MnO NPs exhibit faster and more precise antagonistic actions against phytopathogenic bacteria than fungi; they could be employed as an alternative and promised nano-bio-pesticide to manage a variety of different types of disease-pathogens in the future.
The quality of road pavements is an important factor to ensure an acceptable level of service and safety to the road users. When flexible road pavements are to be constructed on weak sub-grade soils, ...it is often necessary to provide a stabilised sub-base to improve their relevant engineering properties. This paper presents the results and observations from a laboratory investigation evaluating the compaction properties of road sub-base stabilised with Type I cement (ordinary Portland cement) and styrene-butadiene latex copolymer. The proposed polymer contents were 0.5%, 0.75%, 1% and 2% and the proposed cement contents were 2%, 3% and 5%. The 2.5kg rammer compaction test was conducted on the gravelly SAND and sandy GRAVEL samples. It was found that the maximum dry densities (MDD) for the untreated soil samples were higher than the cement-polymer-treated soil samples, indicating that the MDD values decrease when cement and polymer are added. The MDD values for gravelly SAND and sandy GRAVEL treated with cement-polymer lied between 2Mg/m3+0.03Mg/m3 and 2.09Mg/m3+0.04Mg/m3 respectively. The optimum moisture contents for gravelly SAND and sandy GRAVEL treated with cement-polymer were maintained at 9%+0.5%. The air void lines for gravelly SAND and sandy GRAVEL lied between 7%+1% and 3%+1% respectively.
•The present work was undertaken with applying AgNPs for coating cotton fabrics to impart antibacterial activity.•The treated fabrics were analyzed by scanning electron microscope, energy dispersive ...X-ray and FTIR.•Silver contents in fabrics were measured using atomic absorption spectroscopy (AAS).•Color coordinates and silver release for the coated fabrics were both detected.•The antibacterial action of the coated fabrics was tested against Gram +ve Gram −ve bacteria.
An ecological and viable method for coating of cotton fabrics with silver nanoparticles (AgNPs) has been carried out. Nanocoated fabrics were characterized by scanning electron microscopy, energy dispersive X-ray and infrared spectroscopy. Color coordinates and silver release were assessed and the impact of repeated washings was evaluated. Silver contents were measured using atomic absorption spectroscopy and were 109.07 and 97.85mg/kg for the fabrics treated with 100ppm of AgNPs in presence and absence of binder respectively. Antibacterial activities of the cotton fabrics coated by AgNPs were evaluated qualitatively and quantatively, and the results explored that, regardless of the concentration of AgNPs used, the biocidability was always higher without washing. However, for all coated fabrics, a sufficient antibacterial action still observed after 20 washings. The results revealed that valuable antibacterial textiles which are required in different medical textile fields could be successfully produced.
•The goal of this work is the production of cotton fabrics with biocidal properties.•Preparation of colloidal solution of silver nanoparticles by ecological and viable method using sodium ...alginate.•Physical deposition of AgNPs on the surface of cotton fabrics with/without using binder was achieved.•Characterization of the AgNPs-coated fabrics was carried out through different measurements.•The bactericidal behavior of the coated fabrics was detected by two techniques, quantitative and qualitative techniques.
In recent years nano-sized particles have been focused on bacteriostasis. We investigated antimicrobial activities by applying AgNPs–alginate composite on cotton fabric, using a simple one-step rapid synthetic route by reduction of silver nitrate using alkali hydrolyzed alginate solution which acts as both reducing and capping agent. FTIR spectra, color coordinates, silver content, silver release percent and SEM images of treated fabric samples confirmed the successful physical deposition of AgNPs–alginate composite on the fabric. The treated fabrics demonstrated an excellent antibacterial activity against the tested bacteria, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. A slight decrease in the antibacterial feature of the cotton fabrics was observed after successive washings. However, an efficient antibacterial activity still remained on the fabrics.
•This study is concerned with synthesizing AgNPs using pectin.•The concentration of reducing sugars was measured using dinitrosalicylic acid.•UV–visible spectroscopic data was systematically ...studied.•Transmission electron microscope images were studied.•Studying the particle size and size distribution of the prepared nanoparticles.
Monodispersed silver nanoparticles capped by pectin were prepared by the reaction of silver nitrate with alkali hydrolyzed pectin at 70°C for 30min. Spherical and size-regulated silver nanoparticles were prepared using alkali hydrolyzed pectin as a reducing and particle-stabilizing agent. This approach is facile, effective, rapid, and convenient for the large scale preparation of silver nanoparticles. UV–visible spectral analysis confirmed that the nanoparticles consisted of metallic silver. Transmission electron microscopy (TEM) was used to estimate particle size and size distribution of the produced silver nanoparticles. Transmission electron microscopy and size distribution analysis revealed the presence of spherical silver nanoparticles with a main diameter of 5–10nm and have a narrow size distribution. The concentration of reducing sugars was monitored by using dinitrosalicylic acid. A comprehensive schematic mechanism for the formation of silver nanoparticles using pectin is proposed.
In this article the perturbed Gerdjikov-Ivanov (GI)-equation which acts for the dynamics of propagation of solitons is employed. The balanced modified extended tanh-function and the non-balanced ...Riccati-Bernoulli Sub-ODE methods are used for the first time to obtain the new optical solitons of this equation. The obtained results give an accuracy interpretation of the propagation of solitons. We held a comparison between our results and those are in the previous work. The efficiency of these methods for constructing the exact solutions has been demonstrated. It is shown that these different technique's reduces the large volume of calculations.
•This study is concerned with discovering novel, easily applicable and green approach for synthesizing AgNPs.•The concentration of reducing sugars in the reaction mixture was measured using DNS ...(dinitrosalicylic acid) reagent.•UV–visible spectroscopic data was systematically studied for indicating the presence AgNPs.•Transmission electron microscope (TEM) images were presented to confirm the presence of silver nanoparticles.•Particle size and size distribution of the prepared nanosilver under the different experimental conditions were studied.
A new method to prepare silver nanoparticles was reported. Alginate colloidal solution containing chemically synthesized silver nanoparticles (AgNPs) was investigated regarding the nanoparticles stabilization and possibilities for production of alginate based nanoparticles. The formation of AgNPs has been confirmed by UV–visible spectroscopy and monitoring of reducing sugars in the reaction was carried out. The morphology of synthesized silver nanoparticles was characterized by transmission electron microscopy (TEM). The results showed that the morphology of Ag nanoparticles is spherical and the main size is about 1–4nm.
In Egypt, it seems that adolescent girls are a candidate for Vitamin D Deficiency (VDD), mostly due to inadequate sun exposure as a result of the culture and social dress codes and dietary factors. ...Currently, there is growing evidence that VDD is associated with Iron Deficiency Anemia (IDA).
To investigate the frequency of VDD in adolescent females with IDA in comparison to healthy control and demonstrate whether VD level was correlated with serum iron indices.
Forty adolescent females with known cases of IDA (group 1) and 30 healthy females matched for age as a control (group 2) were selected. We compared the differences between the two groups to determine the degree of VD level; where VDD was defined as 25-hydroxyvitamin D 25(OH)D ≤20 ng/mL, vitamin D insufficiency (VDI) as 25(OH) D of 20-30 ng/mL, and vitamin D sufficiency (VDS) as 25(OH)D >30 ng/mL. Body mass index (BMI), complete blood count (CBC), serum iron, total iron binding capacity (TIBC), serum ferritin, serum creatinine, ionized calcium and 25(OH)D were measured for all participants.
We found that subnormal vitamin D (VDD and VDI) was more frequent in the IDA group (75%) than control (40%), (p = 0.025); where 19 adolescent female patients (47.5%) were VDD, 11 (27.5%) were VDI and 10 (25%) were VDS, while in the control group, VDD was present in 4 (20%), VDI in 4 (20%) and VDS in 12 (60%) respectively. There was not any significant correlation between serum VD and serum iron indices (r =0.168, p < 0.05) and Hb (r = 0.360, p < 0.001). There was no significant difference in serum hemoglobin level between IDA patients with subnormal VD and those with VDS. The mean level of serum 25(OH) D was significantly lower in winter months than summer in both groups; (16.87 vs. 31.57 mg/dL, p < 0.001) and (31.9 vs. 35.04 mg/dL, p < 0.001) respectively. BMI, Iron, TIBC and seasonal variation were not predictors of 25(OH) D levels in adolescent girls with IDA.
VDD has a higher frequency in Egyptian adolescent females with IDA than healthy control. However, vitamin D levels were not significantly correlated with iron indices. Our result might direct the attention for measuring vitamin D level in patients with IDA with the possibility of VD supplementation with iron.
PDF
