Silicon最新文献

The application of Silicon modulates the plant defense mechanism by signaling secondary defense metabolites activating signal transduction pathways further triggering the HIPVs which in turn attracts natural enemies thereby suppressing the pest population. Continuous mono culturing of high yielding varieties with intensive cultural practices lead to depletion of available Si in soils and hence exogenous application of Si sources is necessary. Exploiting plant resistance and strengthening the induced defenses through Si and PGR could represent an effective viable alternative to synthetic insecticides that could form an efficient tactic in integrated pest management including biological control. In this context, we underscore recent advancements in understanding Si-mediated enhancement of plant resistance against pests, emphasizing the significance of these findings for potential incorporation into future strategies for crop protection.

Drought, one of the most frequent natural disasters, is a devastating abiotic stress that arises unpredictably, develops gradually, and carries long-lasting repercussions even after it ceases. The duration and severity of drought markedly impact plant growth, development, and yield by disrupting normal morpho-physio-biochemical processes. Silicon (Si) is regarded as a crucial element for mitigating the detrimental effects of abiotic stress, including drought. The objective of this study was to evaluate the effect of Si application method on morpho-physio-biochemical traits of cucumber plants under drought stress. Two independent polyhouse experiments were conducted where cucumber (Cucumis sativus L.) plants were grown under four levels of soil moisture that included 40%, 60%, 80%, and 100% field capacity (FC) and Si was applied either in the form of seed priming (Experiment 1) or as soil drench (Experiment 2). For the seed priming study, four doses of Si (in the form of monosilicic acid with 20% Si content) applied were 0.25, 0.5, 1.0, and 2.0 mM along with a control in which seeds were sown directly without any priming. For the soil application study, four doses of Si (in the form of monosilicic acid with 20% Si content) applied were 15, 30, 60, and 120 kg ha^–1 along with a control. The minimal soil moisture level (40% FC) resulted in 55–68% and 53–76% reduction in root dry matter in Experiment 1 and Experiment 2, respectively, in comparison to that at 100% FC throughout Si doses. Fruit yield, irrigation water productivity, and net photosynthetic rate exhibited a respective reduction of 77–84% and 78–84%, 25–52% and 13–47%, and 37–46% and 26–33% in Experiment 1 and Experiment 2, respectively, at 40% FC than those at 100% FC throughout Si doses. The exogenous application of Si was equally efficient irrespective of application methods. Seed priming with 0.5 mM Si outperformed all other doses and resulted in an increase of 199–284%, 169–263%, and 20–59% in fruit yield, irrigation water productivity, and net photosynthetic rate, respectively, in comparison to the control throughout soil moisture levels. Among different soil application doses of Si, 60 kg ha^–1 was the most efficient, which resulted in 217–293%, 198–307%, and 11–33% enhancement in fruit yield, irrigation water productivity, and net photosynthetic rate, respectively, in comparison to the control throughout soil moisture levels. Exogenous incorporation of Si as seed priming at 0.5 mM and as soil drench at 60 kg ha^–1 is recommended for cucumber cultivation in drought-affected areas.

Recent developments in the fabrication of microfluidic channels of silica glass require repeatability and surface integrity for the industrial purpose of the ECDM process, which is made possible by controlling the dynamic parameters during machining. The characteristics of gas film, i.e., nucleation growth and bubble departure away from the tool, play a vigorous role in enhancing the quality characteristics of ECDM. MHD convection induced by a rotary magnetic field precisely regulates the gas film characteristics. It improves the ejection of particles at higher depths after chemical etching, which enhances the machining capability to fabricate a high aspect ratio microchannel. Various researchers have already done work by applying static magnetic fields in the ECDM process for micro-drilling. This work uses the novel approach of the rotary magnetic field in the electrochemical discharge machining process to fabricate microchannels using an in-house fabricated RMAECDM (Rotary magnetic field assisted ECDM) setup. The percentage reduction in the width overcut obtained by a rotary magnetic field compared to conventional ECDM and static magnetic field application is 21% and 8 %, respectively, under the same environments. Nature-inspired algorithms, coupled with Taguchi techniques, were applied to find the optimal setting of input parameters. The optimal voltage setting, concentration, field rotation, and magnetic strength are 40V,20%, 20000 RPM, and 220mT.

Nowadays Alternaria is considered one of the main fungi causing damage in cereal crop such barley. This work was designed to assess the potential role of silicon dioxide nanoparticles (SiO₂ NPs) in enhancing barley's tolerance against A. alternata attack. For this purpose, twenty day-olds, seedlings were irrigated either with tap water or with SiO₂ NPs solutions at 20 and 200 ppm for one week. After that, different group of seedlings were exposed to fungus inoculation and the others serve as control. The results showed that the fungi attack reduced seedlings biomass, hydration status, transpiration, stomatal conductance, total antioxidant activity, and DPPH levels compared to non-inoculated seedlings. Meanwhile, there was an increase in total phenolic compounds and flavonoid contents. The application of SiO₂ NPs in absence of inoculation, resulted in an increase in seedling shoot length, shoot and root biomass, and water content at any NPs concentrations. Furthermore, when applied prior to inoculation at both concentrations (20 and 200 ppm), SiO₂ NPs mitigated the effects of pathogen attack by enhancing net CO₂ assimilation rate, internal CO₂ concentration, transpiration, and stomatal conductance and increasing total antioxidant activity and DPPH antioxidant profiles compared to inoculated plants. The shoot exhibited a significant increase in zinc, iron, manganese, and potassium with SiO₂ NPs at 200 ppm, regardless of the presence of fungi. The substrate's pH and conductivity remained unchanged compared to the control. However, there was a notable increase in nitrogen, manganese, potassium, and iron contents. On the other hand, levels of zinc and copper slightly decreased. This exploratory work highlights the protective role of SiO₂ NPs in barley seedlings under pathogen attack conditions possibly due to the Si-mediated protection against oxidative stress and photosynthesis modulation. Using SiO₂ NPs as a supplement offers a cost-effective and an eco-friendly and avenue for sustainable agriculture. They aid in nutrient delivery, help plants combat biotic stress, and enhance plant tolerance.

In this study, an adiabatic mode circulator based on the adiabatic mode evolution mechanism with thickness of 220 nm for the cyclic transfer of TE₁ modes is presented, which has two adiabatic mode converters suitable for mode conversion between TE₁ and TM₀ modes, and four adiabatic taper waveguides suitable for the transfer of either TE₁ or TM₀ modes. Due to the symmetry of the structure, only the first half needs to be considered: the first adiabatic taper waveguide evolves the TE₁ mode at width W₁ = 1.5 μm to the TE₁ mode at width W₂ = 0.7 μm. The first adiabatic mode converter evolves the TE₁ mode at width W₂ = 0.7 μm to the TM₀ mode at width W₃ = 0.62 μm. The second adiabatic taper waveguide evolves the TM₀ mode at width W₃ = 0.7 μm to the TM₀ mode at width W₄ = 0.4 μm. The design results show that the adiabatic mode circulator designed in this study can achieve the same power transfer efficiency with an ultra-compact device size compared with other design methods (such as the design approach in Ref. (Dai et al. Opt Exp 20(12):13425-13439, 2012). The device length of the proposed adiabatic mode circulator has been reduced by a factor of 80 compared to the design approach in Ref. (Dai et al. Opt Exp 20(12):13425-13439, 2012). As a result, the device size of the proposed adiabatic mode circulator is drastically reduced, enabling the design of ultra-compact adiabatic mode circulators.

In this study, a Mg-X wt.%SiO₂ (X = 1, 2) nanocomposite was developed using amorphous silica nanoparticles via the accumulative extrusion method. The reinforcement phase was added to the matrix between extrusion passes. The study evaluated the mechanical properties of the composite samples via compression and hardness tests, while the microstructure and texture were analyzed using optical microscopy, field emission scanning electron microscopy (FESEM) and X-ray diffractometry. To remove the deformation history and examine the effect of the reinforcement phase on mechanical properties, the samples were annealed in an argon atmosphere. In addition, monolithic magnesium samples were fabricated through the same process to serve as a basis for comparison. This study revealed that adding 1 wt% amorphous silica nanoparticles to the magnesium matrix improved the overall mechanical properties. However, the nanocomposites displayed varying properties in different directions. Along the extrusion direction, the yield strength and ductility increased up to 57% and 5%, respectively, while the ultimate compressive strength decreased by about 8%. Along the normal direction, the yield strength and ductility increased up to 37% and 45%, respectively, while the ultimate compressive strength decreased by about 9%. The Mg/2wt.%SiO₂ nanocomposite sample showed superior Brinell hardness. The number of extrusion passes had a significant impact on the distribution of nanoparticles within the matrix. The optical microscope micrographs revealed that the reinforcement phase was uniformly distributed throughout the matrix, and no agglomeration of nanoparticles was observed. The X-ray diffraction results demonstrated that the texture of nanocomposite samples weakened after adding nanoparticles, resulting in improved ductility.

The recovery of silicon and copper from spent silicon contact mass (SSCM) holds significant importance for environmental protection and resource scarcity. This study introduced a novel strategy that combines low-temperature and oxygen-poor roasting, and selective leaching, exhibiting high efficiency in recovering Si and Cu in the form of Si–Cu powder from SSCM. The recovered Si–Cu powder can be used as high-quality raw materials for Si–Cu composite materials, and is expected to continue to be used as monomer production raw materials. A protective Si oxide layer on the outer surface, formed during the low-temperature and oxygen-poor roasting process, preventing the undesirable oxidation of Si powder, and the C in the SSCM was effectively removed. The chemical stability difference between Cu and other metallic elements was exploited during selective leaching with mixed HCl–HF acid, resulting in the targeted removal of impurities. The thermodynamics of impurity leaching was analyzed by E-pH diagram, and the kinetic behavior of impurity leaching was described elucidated using homogeneous model. This innovative strategy marks the first instance of combining C removal with selective leaching of metallic impurities, achieving efficient and functional utilization of SSCM. This study offered a new and effective approach to SSCM treatment.

The gamma ray shielding characteristics of different borosilicate glasses are examined in this work. Four glasses with a composition of 60B₂O₃–5Na₂O–5PbO–(30-x)SiO₂–xBaO, (x = 5, 10, 15, and 20 mol%) were created using the conventional melt quenching technique followed by an annealing step. Linear attenuation coefficient, LAC, values have been determined using HPGe semi-conductor detector. These values were compared with calculated values estimated from Phy-X software and a good matching was observed. The samples were irradiated using the point sources viz., Am²⁴¹ (0.0595 MeV), Cs¹³⁷ (0.6617 MeV) and Co⁶⁰ (1.173 and 1.330 MeV). The LAC data were further utilized in computations of other radiological parameters that are half value layer (HVL) and Tenth value layer (TVL). Furthermore, radiation shielding efficiency (RSE) of the prepared glass materials has been evaluated. The sample 10S20B exhibits higher values of LAC than the others because it has the largest density and weight fraction of elements with higher atomic numbers. The significance of the atomic number and density parameters-higher atomic number and density imply greater probability of interaction, leading to better attenuation.

Calcium oxide and silicon oxide are combined to form calcium silicate. Since calcium silicate materials offer tuneable physical, chemical, mechanical, and optical characteristics, these materials have found uses in various applications such as luminescence, batteries, bioimaging, supercapacitors, and concrete materials. In the majority of applications, high-purity calcium silicate is produced from chemical precursors such as calcium/silicate oxides or nitrites, even though this method could be expensive, environmentally harmful, and non-biocompatible. As an alternative, natural calcium and silica from biomass are usually economical and abundant, yet they contain impurities but sometimes the trace impurities influence the properties of material in positive ways. Silica can be extracted from wheat husk, rice husk, and sugarcane bagasse, which are frequently dumped in rivers, ponds, and other water bodies, contributing to ecological and health problems, likewise, calcium oxide can be extracted from eggshells, marble waste, snail shell. The trash may recycle or utilized to create marketable, value-added items with significant ecological and financial benefits rather than being dumped. The purpose of this review paper is to discuss the composition, processing, and applications of calcium silicate derivatives. The analysis shows that calcium silicate derivatives have enormous potential for using waste as a replacement of organic precursor materials.

Methylene blue dye (MB), prevalent in textiles like cotton, wood, and silk, raises environmental and health concerns. This study presents a successful synthesis of a Bayerite/zeolite nanocomposite powder using fumed silica by-product and aluminum nitrate. Hydrothermal exploration of factors, including duration, temperature, and Al/Si ratios, revealed that high temperature (160°C) and short duration (6h) favored optimal crystallization of bayerite/zeolite phases. Subsequently, an integrated photocatalytic adsorbent (IPA) was developed by mechanically mixing the synthesized bayerite/zeolite with TiO₂, followed by calcination (500 °C, 2 h), demonstrating superior efficiency in MB photodegradation under UV–Vis light. The IPA achieved 100% degradation efficiency for 60 mg/L of MB and maintained good photostability over three cycles. The bayerite/zeolite-supported TiO₂ nanocomposite exhibited the generation of positive holes (h +) and active hydroxyl radicals (OH•), showcasing its potential as a promising material for wastewater treatment applications.

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