Ppm Si Research Articles

Drought stress-induced modification of morpho-anatomical and yield attributes of mung bean associated with the application of silicon and Moringa leaf extract

Mung bean (Vigna radiata) is the rich source of fiber and essential nutrients. They play a vital role in sustainable agriculture due to their ability to fix nitrogen in the soil and enhance soil fertility. Drought is characterized by limited water resources and severe arid climatic conditions, notably impair crop growth and yield. In the current experiment, two genotypes, Azri-M 2006 and NM-92, were studied against drought stress that was applied as 2 days and 4 days irrigation gap per week. Foliar application of magnesium-silicate (20 ppm and 30 ppm concentrations) and Moringa leaf extract (30% v/v solution) was applied as treatments. The results from the experiment morphology anatomical and yield components were recorded according to the prescribed methods. The result revealed that drought stress reduced the growth of plant. Foliar application of 30 ppm silicon against drought stress showed a highly significant (p<0.001) result compared with control group. Morphology parameters, including shoot and root length, shoot and root fresh weight, root dry weight, leaf area, leaf number, the anatomical structure included (stem epidermis, cortex, and stem vascular bundles,) and also yield components (pod length, and seed numbers). In contrast, MLE (30%) showed a significant impact (p<0.01) on leaf lamina thickness (Leaf anatomical parameters; midrib xylem and phloem, number of stomata on the adaxial and abaxial surface) and yield components included (100-grain weight, grains weight per plant, and numbers of pods,). The overall impact of 30 ppm Si was 39.9% more positive on Azri-M2006 than the NM-92 against the drought stress. The 30-ppm silicon and 30% MLE showed 90% similar results in all studied parameters. This study confirms that 30% MLE could be recommended to farmers to improve productivity under arid conditions than the silicon.

Effect of Silicon on the Fruit Quality and Disease Response to Gummy Stem Blight in Cucumber

Gumm y stem blight (GSB) caused by Stagonosporopsis cucurbitacearum is the most destructive fungal disease affecting cucumber (Cucumis sativus L.) production. In Thailand, cucumber is one of the most popularly marketed vegetables and the cultivation of cucumbers or Cucurbitaceae often face impact epidemics and insect infestation. Furthermore, global climatic or climate change affects crop production too, which increases the frequency and severity of disease and pest outbreaks. Silicon (Si) enhances plant resistance against insect pests and fungal, bacterial, and viral diseases although Si is not the only beneficial element for plants but also it does play an important role in improving plant health and increasing resistance against pests and diseases. Therefore, the aim of the study was to investigate the effect of Si-application at two levels i.e., 50 ppm, and 100 ppm on yield, yield components, aroma, Si-concentration and disease response of cucumber under greenhouse condition in a randomized complete block design with 4 replications. Results, when compared with control, depicted that the highest fruit weight, marketable yield, fruit length, fruit width, and pith length were found under 50 ppm Si. Moreover, higher Si-levels resulted in increased aroma in rind (exocarp) and increased percentage of Si-concentrations in rind (exocarp), leaves, and shoot. Further in this research, the response of Gummy stem blight disease (GSB) in cucumber was also investigated the response of. The taxonomic identification of Stagonosporopsis cucurbitacearum was confirmed based on the evidence from morpho-molecular analyses and the pathogenicity test was performed to confirm its potential pathogenicity. The results showed that the varying treatments of Si affects the disease development. The 50 ppm Si caused the lowest disease response on cucumber fruits. This study can be used as a guideline for modifying Si-fertilizer application inputs to plants to increase disease resistance and fruit quality.

Enhanced Growth of Chili (Capsicum annuum L.) by Silicon Nutrient Application in Fertigation System

Silicon (Si) is one of the most abundant elements naturally available in the soil. This element performs an essential function in improving plant growth. This present study was carried out to evaluate the impact of Si nutrient application on the growth performance of chili (Capsicum annuum L.). Chili plant grown using a fertigation system was subjected to manual application of a silicon nutrient solution in varying concentrations (0 ppm, 108 ppm, 180 ppm, & 360 ppm) via root application. Each treatment was replicated five times, with five plants in each replicate, and all plants were grown in a shade house. The growth performance parameters measured were the number of leaves, stem diameter, plant height, plant biomass (dry weight), and Si accumulation in the stem, leave, and chili fruit. Results showed that Si nutrient application significantly affected the growth performances of chili plants. Application of T3 (360 ppm Si nutrient) was able to produce the highest stem diameter (8.92 mm), fresh weight (129.63 g), dry weight (67.23 g), as well as Si accumulation in stem (54 ppm), and chili fruit (24 ppm). On the other hand, applications with T2 (180 ppm Si nutrient) also demonstrated the highest plant height (20.98 cm), number of leave (27), and Si accumulation in leave (87 ppm). In conclusion, the application of silicon nutrients has the potential to enhance plant growth in numerous crops, making it a beneficial supplement to traditional agricultural practices.

Effect of Exogenous Salicylic Acid and Silicon Application on Salinity Tolerance of Rice

Soil salinity remarkably hinders rice growth, development and productivity. The present study was set up to explore the role of exogenous salicylic acid (SA) and silicon (Si) application on the growth and yield performance of two contrasting rice genotypes, namely BRRI dhan41 (salt-tolerant) and BRRI dhan49 (salt-sensitive) under salinity. The experiment was laid out in a randomized complete block design with three replications and four SA and Si treatments such as control (tap water), 100 ppm SA, 100 ppm Si (as CaSiO3) and, co-application of SA and Si (50 ppm each). Results revealed that the maximum plant height (125.2 cm), fresh weight of shoot (267.3 g) and maximum K+/Na+ (5.2) were obtained in BRRI dhan49 after sole application of Si under salt stress. Besides, the number of grains per panicle and grains per hill significantly increased in BRRI dhan41 after the sole application of SA (64 and 46%, respectively) and co-application of SA and Si (29 and 21%, respectively), and in BRRI dhan49 with sole SA (182 and 277%, respectively) and Si (75 and 446%, respectively) compared with their respective controls. Besides, we observed that the K+/Na+ was increased where the shoot accumulation of Na+ reduced significantly in both rice varieties after sole and co-application of SA and Si compared with the untreated plants. However, the present findings showed new dimensions regarding the beneficial effects of Si on rice plants which could effectively be utilized to grow and maximize rice production in the saline-prone coastal areas of Bangladesh encountering detrimental effects of salt stress on rice.
 Bangladesh Agron. J. 2022, 25(2): 119-127

Performance Evaluation of Silica–Graphene Quantum Dots for Enhanced Oil Recovery from Carbonate Reservoirs

Nanomaterials have shown significant performances in enhancing oil recovery by reducing the interfacial tension (IFT) and contact angle (CA) of the rock/crude oil/water system in porous media. This is evaluated by the synergistic impact of silica–graphene quantum dots (Si–GQDs) on IFT reduction and wettability alteration for the purpose of enhancing oil recovery from carbonate reservoirs. The silica–graphene quantum dots (Si–GQDs) were synthesized by combining graphene oxide and silicon oxide nanoparticles (NPs) and characterized using several analytical techniques. Both distilled water and brine, as dispersion media, were used to prepare nanofluids by dispersing the synthesized Si–GQDs at different concentrations from 1000 to 10,000 ppm. The main properties of the nanofluids including pH, density, and conductivity were measured to evaluate their quality and the performance of Si–GQDs. In addition, the prepared nanofluids were used in the measurements of IFT and contact angles at different concentrations of the synthesized Si–GQDs in both types of used water. The obtained results show that the DWN1000 nanofluid formulated from dispersing 1000 ppm Si–GQDs in distilled water enables an additional 14.4% OOIP oil recovery due to a significant reduction in the value of IFT from 28.3 to 9.5 mN m–1, improving rheology behavior and wettability alteration toward a strong water-wet system from 134 to 61° contact angles.

Anti-inflammatory properties of S53P4 bioactive glass implant material

ObjectivesTo assess whether the dissolution products of S53P4 bioactive glass (BG) affect cellular response of macrophages and clinically relevant peri‑implant cell populations to dental implant particles in vitro. Cells chosen were human gingival fibroblasts (HGFs), osteoblasts and bone marrow derived stromal cells (HBMSCs). MethodsMelt-derived S53P4 bioactive glass were prepared. HGFs, Saos-2 human osteoblastic cell line, HBMSCs and macrophages, derived from THP-1 human monocytic cell line, were cultured in the presence of particles from commercially pure titanium (Ti-CP4), grade 5 titanium alloy (Ti-6Al-4V), titanium-zirconium alloy (Ti-15Zr) or zirconia (Zr) (with respective diameters of 34.1 ± 3.8, 33.3 ± 4.4, 97.8 ± 8.2 and 71.3 ± 6.1 µm) with or without S53P4 dissolution products (conditioned media contained 327.30 ± 2.01 ppm Ca, 51.34 ± 0.41 ppm P and 61.48 ± 1.17 ppm Si, pH 8.01 ± 0.21). Inflammatory and macrophage polarisation markers including TNF-ɑ, IL-1, IL-6 and CD206 were quantified using enzyme-linked immunosorbent assay (ELISA). ResultsThe presence of Ti-6Al-4V implant particles significantly induced the expression of pro-inflammatory markers in all tested cell types. S53P4 BG dissolution products regressed the particle induced up-regulation of pro-inflammatory markers and, appeared to suppress M1 macrophage polarisation. ConclusionsImplant particles, Ti-6Al-4V in particular, resulted in significant inflammatory responses from cells. S53P4 BG may possess anti-inflammatory properties and potentially mediate macrophage polarisation behaviour. Clinical SignificanceThe findings highlight that the use and benefits of BG is a promising field of study. Authors believe more collective efforts are required to fully understand the reliability, efficiency and exact mechanisms of action of BG in the search for new generation of treatment modalities in dentistry.

Potential Benefits of Silicon Nutrition to Hydroponically Grown Sweet Basil

Sweet basil (Ocimum basilicum L.) is a globally cultivated and consumed herb known for its unique aroma and flavor. Sweet basil grows best in warm temperatures, and productivity and marketability decrease when grown under cool conditions (<10 °C). Silicon (Si) is not considered an essential plant nutrient, but it can be beneficial to Si macroaccumulator plants by alleviating several biotic and abiotic stresses. Recent studies have shown that some microaccumulator species may also benefit from Si. In this study, we examined the effects of different levels (0, 25, and 75 ppm Si) of Si amendments on hydroponic basil grown at 23 °C. Si (75 ppm) significantly increased shoot height and weight with no negative impact on plant morphology. All Si-treated basil plants absorbed Si in small quantities and affected the uptake of phosphorus, magnesium, sulfur, iron, manganese, copper, zinc and molybdenum. After an unintentional frost event, basil plants treated with 75 ppm had significantly higher survival rates and reduced cold injury symptoms. We concluded that Si amendments can have a positive impact on hydroponically grown sweet basil, and that such amendments may reduce plant damage due to occasionally cooler growing temperatures.

Ameliorative Effects of Organic Fertilizer, Trichoderma and Silicon on Productivity and Quality of Tomato Grown under Contaminated soil Conditions

The present study was carried out during the summer seasons of 2017 and 2018 in Talkha city, Dakahlia Governorate, Egypt near El-Mansoura-Damietta highway and El Delta Company for Fertilizers and Chemical Industries, where lead (Pb) and copper (Cu) levels in the soil exceed the permissible levels. Therefore, the aim of this study was to alleviate the adverse effects of heavy metals (HMs) on tomato plant (Solanumlycopersicum L.) Super Strain B F1. Twelve treatments were conducted which were the interactions between two silicon (Si) foliar spraying (without or 300 ppm Si) and six soil amendments : 100% chemical fertilizers (CF), 50% farmyard manure (FYM), 100% FYM, 100% CF+ Trichoderma spp. (T.), 50% FYM + T. and 100% FYM + T. Data indicate that Pb and Cu were accumulated in tomato organs to hazardous levels in the following descending order : roots > shoots > fruits and shoots > roots > fruits, respectively which consequently severely reduced tomato plant growth and fruit yield and fruit quality. Results also, showed that the application of Si treatment sole or in combination with soil amendments markedly enhanced plant height, dry weight, total chlorophyll, number of fruits/plant, total yield/fed, Vitamin C, acidity %, TSS and taste index, where as, reduced Pb and Cu concentrations in different plant organs, bio-concentration factor (BCF) and translocation factor (TF). However, Si + FYM + T. treatment was superior in these respects, therefore increased the net return. Also, negative correlations were obtained between fruit yield and BCF of Pb or Cu and between taste index and TF of Pb or Cu.

Enhancing Water Use Efficiency in Sandy Soil Using some Organic and Mineral Additives under Deficit Irrigation during Vegetative Growth of Peanut

A field experiment has been carried out at the Ismailia Agricultural Research station, Agricultural Research Center (ARC), Egypt, during the summer seasons of 2017 and 2018. It aimed to study the effect of deficit irrigation during vegetative growth and addition of humic acid (Hu), gibberellic acid (GA3), silicon (Si), potassium (K) and calcium (Ca) on peanut yield and its components. The present work included three irrigation treatments, T1 irrigation with amount of 100% ETc, imposed from 10 days after sowing until harvest, T2 irrigation with amount water equal to 60%ETc imposed 10 days after sowing until 38 days after sowing after which with 100% ETc until harvest, T3 irrigation with amount of water equal to 80% ETc imposed from 10 days after sowing until 38 days after sowing follows with 100% ETc maintained until harvest. Foliar spray included 5000 ppm Hu, 150 ppm GA3 and 200 ppm Si. Potassium K was added as soil application before sowing at a rate of 100 kg ha-1 as K2SO4 and Ca was applied during soil preparation as CaSO4 at rate of 500 kg ha-1. The fully irrigated treatment T1 100% ETc yielded the highest pods and kernel yield but non-significant difference from T2 and T3. WUE and IWUE increased by deficit irrigation during vegetative growth. Application of Hu, GA3, Si, K and Ca significantly increased peanut pods and kernel yield and had significant effect on WUE and IWUE.

Inhibition of the negative effect of high glucose on osteogenic differentiation of bone marrow stromal cells by silicon ions from calcium silicate bioceramics.

Human bone marrow stem cells (hBMSCs) are exploited for miscellaneous applications in bone tissue engineering where they are mainly used as seed cells. However, high glucose (HG) environment has negative impacts on the proliferation and osteogenic differentiation of hBMSCs, thus reducing the bone formation in diabetic patients. In our former research works, we discovered that silicon (Si) ions extracted from silicate-based bioceramics are able to stimulate the proliferation and osteogenic differentiation of hBMSCs under normal culture condition. This study aimed to investigate if Si ions could prevent HG-induced inhibition of proliferation and osteogenesis of hBMSCs. We found that 2.59 ppm concentration of Si ions promoted the proliferation of hBMSCs under HG condition. The results from alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time PCR analysis of osteogenic genes (BMP2, RUNX2, ALP, COL1 and OCN) demonstrated that the 15.92 ppm concentration of Si ions prevented HG-induced inhibition of the osteogenic differentiation of hBMSCs. Moreover, application of Si ions reduced the level of reactive oxygen species in HG-treated hBMSCs. In HG-treated hBMSCs following 15.92 ppm Si ions treatment, activation of BMP2/SMAD signaling pathway was detected, as indicated by the increased expression of BMP2 receptors and its downstream genes such as SMAD1, SMAD4 and SMAD5. Taken together, we provide evidence that the specific concentration of Si ions compensated HG-induced inhibition of proliferation and osteogenic differentiation of hBMSCs through antioxidant effect and modulation of BMP2/SMAD pathway. The results suggest that silicate-based bioceramics might be good scaffold biomaterials for bone engineering applications in diabetes patients.

Time-sequential corrosion behaviour observation of micro-alloyed Mg-0.5Zn-0.2Ca alloy via a quasi-in situ approach

The corrosion behaviour of as-cast and solution-annealed Mg-0.5Zn-0.2Ca alloy containing 150 ppm Si was investigated in 0.9% NaCl solution. The main secondary phases in the as-cast state are isolated MgCaSi and a coexisting intermetallic particle which consists of Mg2Ca and Ca2Mg6Zn3. A quasi-in situ approach is applied to investigate the corrosion initiation and development. It is proved that Mg2Ca phase is anodic and preferentially corrodes within the first hour of immersion. Whereas, Ca2Mg6Zn3 and MgCaSi phases continuously act as cathodes until 24 h. After solution annealing, the more homogeneous microstructure and reduced galvanic corrosion result in a higher corrosion resistance.

Combination of ions promotes cell migration via extracellular signal‑regulated kinase 1/2 signaling pathway in human gingival fibroblasts.

Wound healing is a dynamic process that involves highly coordinated cellular events, including proliferation and migration. Oral gingival fibroblasts serve a central role in maintaining oral mucosa homeostasis, and their functions include the coordination of physiological tissue repair. Recently, surface pre‑reacted glass‑ionomer (S‑PRG) fillers have been widely applied in the field of dental materials for the prevention of dental caries, due to an excellent ability to release fluoride (F). In addition to F, S‑PRG fillers are known to release several types of ions, including aluminum (Al), boron (B), sodium (Na), silicon (Si) and strontium (Sr). However, the influence of these ions on gingival fibroblasts remains unknown. The aim of the present study was to examine the effect of various concentrations of an S‑PRG filler eluate on the growth and migration of gingival fibroblasts. The human gingival fibroblast cell line HGF‑1 was treated with various dilutions of an eluent solution of S‑PRG, which contained 32.0ppm Al, 1,488.6ppm B, 505.0ppm Na, 12.9ppm Si, 156.5ppm Sr and 136.5ppm F. Treatment with eluate at a dilution of 1:10,000 was observed to significantly promote the migration of HGF‑1 cells. In addition, the current study evaluated the mechanism underlying the mediated cell migration by the S‑PRG solution and revealed that it activated the phosphorylation of extracellular signal‑regulated kinase 1/2 (ERK1/2), but not of p38. Furthermore, treatment with a MEK inhibitor blocked the cell migration induced by the solution. Taken together, these results suggest that S‑PRG fillers can stimulate HGF‑1 cell migration via the ERK1/2 signaling pathway, indicating that a dental material containing this type of filler is useful for oral mucosa homeostasis and wound healing.

Effects of Si and Fe micro-additions on the aging response of a dilute Al-0.08Zr-0.08Hf-0.045Er at.% alloy

The precipitation behavior of an Al-0.08Zr-0.08Hf-0.045Er at.% alloy with micro-additions of Si and/or Fe was investigated using microhardness and electrical conductivity measurements in conjunction with scanning electron microscopy and atom-probe tomography. Hardening is achieved through the formation of a high number density (~1023 m−3) of coarsening-resistant, nanoscale L12 trialuminide precipitates containing Zr, Hf, Er, and Si. Simultaneous additions of 300 at. ppm Si and 400 at. ppm Fe produce an alloy with the fastest precipitation kinetics and highest microhardness after homogenization at 640 °C for 24 h followed by 90 days aging at 350 °C, due to: (i) scavenging of Er by Fe in the form of primary precipitates, thus reducing Er-stimulated precipitation of coarse Zr- and Hf-rich precipitates during homogenization; and (ii) the accelerating effects of Si on the precipitation kinetics of the nanometric L12 trialuminide. Removal of the homogenization step results in accelerated precipitation kinetics during aging due to an increased supersaturation of L12-forming elements, Zr, Hf, and Er. During isothermal aging of a non-homogenized Al-0.08Zr-0.08Hf-0.045Er-0.03Si-0.04Fe (at.%) alloy at 400 °C, a peak microhardness of 500 MPa is maintained for up to 90 days. Atom-probe tomography displays a high number density of nanometric L12 precipitates with an Er-rich core and homogeneously distributed Zr and Hf, with Hf concentrations ~1.5 times higher at the matrix/nanoprecipitate heterophase interface than in the core (~5 vs. ~3.5 at.%). The presence of Hf in the nanoprecipitates does not, however, affect their precipitation kinetics or coarsening resistance.

Kinetic study of the thermal decomposition of octamethylcyclotetrasiloxane on activated gamma alumina

Biogas produced at wastewater treatment plants and landfills is contaminated with siloxanes that impedes its use as fuel. Before being safe to use in solid oxide fuel cells or engines, siloxane contamination must be reduced to below 0.01 and 9.1ppm (vol/vol) Si equivalent respectively. The literature has identified thermal decomposition in a packed bed of heated gamma alumina as a method that can remove siloxanes to the requisite levels Finocchio (2008) & Urban (2009). Missing from the literature is a kinetic study of the decomposition reaction where a theoretical model is fitted to experimental breakthrough curves so that breakthrough times can be predicted. The present work is this kinetic study.Experiments with synthetic biogas (0 to 100% methane and carbon dioxide mixtures) contaminated with octamethylcyclotetrasiloxane (D4) at concentrations between 32.3 and 72.7ppm (vol/vol) Si equivalent were conducted. Beds of alumina were exposed to the gas at temperatures between 307 and 384°C for contact times between 5.0 and 8.0ms. The effluent D4 concentration was measured by GC-FID.The breakthrough curves obtained were fitted with a kinetic model that assumed a first order surface reaction, shrinking core particle kinetics, and plug flow in the reactor. For temperatures between 333 and 384°C, the model fit the data well, most especially near the breakthrough point. Experimental conditions had no effect on quality of fit. At 307°C, the model was inadequate; possibly due to D4 physisorption or shrinking core kinetics assumptions not holding true anymore.

Soil application of potassium silicate reduces the intensity of downy mildew in bitter gourd (Momordica charantia L.) leaves

Effect of soluble silicon (Si) on downy mildew in bitter gourd ( Momordica charantia L.) leaves caused by Pseudoperonospora cubensis was tested using three concentrations of liquid potassium silicate (100, 200, 300 mg Si/kg) added to the growing medium containing top soil, compost and sand. Disease severity, plant growth parameters, silicon accumulation on leaves and cuticle-epidermal layer thickness of transverse sections of leaves were measured. Si treated plants exhibited less disease severity than that of control plants and 200 mg Si/kg treatment resulted in highly significant disease suppression (37 - 53% reduction against controls). The suppression of the disease strongly correlated with the Si accumulation in leaves. Cuticle-epidermis thickness was higher in Si- treated leaves (17.2 - 21.3 μm) against non-treated (10.3 - 13.81 μm). Numbers of leaves, flowers or fruits in Si treated plants were significantly higher (p < 0.05) than control plants except in 300 ppm Si level. Structural changes created by Si may at least be partly responsible for reducing the fungal disease severity in bitter gourd leaves.

Quality control of (Th,Pu)O2 fuel pellet obtained by coated agglomerate pelletization

(Th,Pu)O2 fuel pellets were synthesised by coated agglomerate pelletization route and characterized for the chemical quality control. (Th,Pu)O2 pellets were characterized for trace metals by spectrometric methods and non metals by ion chromatographic, spectrophotometric, conductometric and manometric methods. H, F, B and Cd contents were found to be less than 1 ppm while that for V and Cl were found to be less than 10 ppm. The pellets were found to contain Cr, Cu, Mo, Na, Ni and Pb in the range of 10–50 ppm whereas Zn, Al, Ca and C in the range of 50–100 ppm. More than 100 ppm Si, Fe and Mg were found to be present in the (Th,Pu)O2 pellets. The O/M content of the pellets were found to be ~2.00. A comparative study on (Infrared) I.R. and microwave (microwave) dissolution were also used to ascertain the Th and Pu content in the (Th,Pu)O2 pellets.

Silicon-Rich, Iron Oxide Microtubular Sheath Produced by an Iron-Oxidizing Bacterium, Leptothrix sp. Strain OUMS1, in Culture

This study aimed to manipulate the texture and elemental composition of the novel sheaths produced by the iron-oxidizing bacterium Leptothrix in culture by altering components of the medium. When previously isolated strain OUMS1 was cultured in media (pH 7.0 throughout incubation) containing various levels of Si on a rotary shaker at 20 °C and 70 rpm for 14 days, the strain was able to reproduce in media with up to 300 ppm Si, and the hollow microtubular architecture of the sheath was maintained even at 300 ppm Si. The constitutional iron oxide phase changed from poorly crystalline lepidocrocite at 0 ppm Si to X-ray diffraction (XRD)-amorphous 2-line ferrihydrite at 100–300 ppm via their mixture phase with intermediate Si content (Si-30 and -50 ppm). The results strongly indicate that the chemical character and crystallinity of the sheath texture can be regulated by culture conditions, especially components of the medium.

Effect of Small Addition of Si on Superplastic Elongation at Room Temperature in Zn-Al Eutectoid Superplastic Alloy

Recent experimental data have revealed that a small amount of impurity can significantly influence the superplastic behavior in Zn-Al eutectoid superplastic alloy. However, the effect of Si content on the superplastic behavior in Zn-Al alloy has not been reported. In this study, the superplastic behavior at a room temperature of two grades of the Zn-Al eutectoid superplastic alloy was studied under identical conditions of grain size, temperature, and strain rate. These two grades were prepared from high-purity Zn, Al and Al-Si alloy using the same procedure but different Si impurity levels; Zn-Al-10Si and Zn-Al-1000Si contain 10 and 900 wt. ppm of Si, respectively. As a result of annealing treatments, an average grain size of 0.6 μm in both grades. To investigate the effects of Si content on superplastic properties, the tensile tests were performed at a room temperature of 298 K and a constant strain rate of 1×10-3 s-1. Microstructures before and after the tensile tests was observed using a scanning electron microscope. The experimental results show that the elongations decreased with increasing the Si content. In contrast, the flow stress of Zn-Al alloys was not affected by the Si content. On the microstructure observation of the two grades of the Zn-Al alloy before and after the tensile tests, cavities existed at grain boundaries and strain enhanced grain growth was observed.

Quantification of Si in Silicone Oils by ICP-OES

A new simple and low cost method of quantification of trace amounts of silicon (Si) in silicone oils has been developed by combining the silicone emulsion and inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. Silicone oils that contained phenyl groups in the viscosity range from 20 to 1000 mPa.s formed stable oil in water emulsions in the presence of Tween 80 surfactant and methylisobutylketone (MIBK). The Si in the emulsions was further quantified by ICP-OES. The calibration was performed using spiked inorganic silicon standard in the emulsions and the method was verified by the standard reference material SRM1066a. The precision and accuracy of the emulsion method applied to three phenyl containing silicone oils and polydimethylsiloxane (PDMS) with low viscosity (10 cSt) were good and acceptable (RSD < 10 % and the error range <10 %) with the limits of detection (LOD) in the emulsion as 0.5 ppm Si. Compared to the Si determination by the direct organic solvent ICP-OES, this method is much more convenient, where a regular ICP-OES instrument can be directly used for the quantification of Si in the silicone oils obtained via extraction by organic solvents from plastics and other samples.

IMPACT THE FOLIAR APPLICATION OF SILICON AND B WITH OR WITHOUT COMPOST ON SOIL FERTILITY AND PEANUT PRODUCTIVITY UNDER NEWLY RECLAIMED SOIL CONDITIONS

Two field experiments were carried out in a private farm at El-Quntra Shark east Suez Canal, Egypt during the two successive summer seasons of 2011 and 2012. Both experiments were conducted to study the influence of spraying on soil surface of Silicon i.e. 0, 50, 100 and 150 ppm and boron i.e. 0, 25, 50 and 100 ppm with or without compost on soil fertility and yield, yield components, oil %, protein, proline, chlorophyll content as well as nutritive status of peanut plants grown on sandy saline soil. The soil is irrigated with Sprinkler from El-Salam canal water (Nile water mixed with agriculture drainage water 1:1). The cultivar of seeds peanut was Gregory. Plant samples were taken at maturity stage to estimate the yield and the chemical composition of seeds. The results showed significant increase in all studied parameters of peanut as compared with the treatment of without compost in both seasons. The highest values of yield and yield components were obtained from plants received foliar spraying with 150 ppm Si and 100 ppm B alone or with compost. Also different rates of Si and B increased significantly the concentration of N, P, K, Si, Zn and B in seeds of peanut in both seasons as compared without compost treatments. The highest values of N, P, K, Si, Zn and B concentrations in seeds of peanut plants were obtained by using (150 ppm of Si and 100 ppm of B combined with compost in both seasons. The highest values of oil (%), protein (%) and chlorophyll contents in peanut seeds in both of seasons were attained when the highest level of Si (150 ppm) and B (100 ppm) alone or combinated with compost. addition as foliar application. The different rates of Si and B led to decreases of proline in both seasons as compared with control. The highest values of proline in both seasons were obtained by using foliar spraying with the low rates of Si or B, under high soil salinity. Soil salinity (EC) was decrease when soil treated with compost combined with highest rates of Si 150 ppm and B 100 ppm. Soil pH decreased with increasing Si and B combined with compost .The highest values of N, P, K, Si, B and Zn were obtained from soil receiving foliar spraying with 150 ppm Si and 100 ppm B alone or with compost. It could be concluded that foliar spray Si and boron at (100 and 150 ppm Si) and (50 and100 ppm B) in combination with compost led to improve soil fertility, enhanced plant growth and peanut yield and its components.