Soaking In Sulfuric Acid Research Articles

Multiplication and development in the nursery of Pterocarpus erinaceus, an endangered agroforestry species in Cote d'Ivoire

Pterocarpus erinaceus is a multi-purpose species threatened with extinction. The present study aims to contribute to the improvement of multiplication and nursery growth of Pterocarpus erinaceus hulled seeds. To this end, four pre-treatments were applied to Pterocarpus erinaceus hulled seeds to lift their dormancy in order to facilitate germination of the species. These were: untreated seeds as Control (To), soaking in ordinary water for 24 h (T1), soaking in hot water at 60°C (T2) and soaking in sulfuric acid (H2SO4) for 20 min (T3). Germination parameters such as germination rate, germination time and average germination time were evaluated. Growth in height, diameter, number of leaves and root length were determined. Germination data and growth parameters were collected. Analyses showed that soaking shelled seeds in ordinary water for 24 h was the best treatment, with a germination rate of 43%. Pre-treatment of the seeds with sulfuric acid for 20 min showed the lowest germination rate (1%), due to the sensitivity of the seeds. Furthermore, these pre-treatments had no effect on seedling growth in the nursery. Those interested in producing Pterocarpus erinaceus seedlings are advised to soak shelled seeds in ordinary water for 24 hours to ensure better germination in the nursery.

Acid resistance and failure mechanism of zinc-rich primer/micaceous iron oxide/polyurethane composite coating immersed in 5 wt% sulfuric acid

In order to study the reliable resistance to sulfuric acid corrosion of epoxy zinc rich primer/micairon oxide intermediate paint/acrylic polyurethane topcoat composite coatings for power transmission and transformation equipment. In this paper, under the condition of immersion in 5 wt% sulfuric acid, the sulfuric acid resistance behaviour of zinc-rich epoxy/micaceous iron oxide/polyurethane composite coating was evaluated by performing soaking tests for 50 h, 100 h and 150 h, and the failure mechanism of the film was studied. The changes in the surface properties of the coating during sulfuric acid soaking were evaluated by testing the hardness, glossiness and adhesion, and the changes in the capacitance and resistance characteristics of the coating during acid soaking were studied by Electrochemical Impedance Spectroscopy (EIS). The micromorphology and chemical element distribution of the cross-section of the composite coatings were studied by Scanning electron microscope (SEM) and Energy-dispersive X-ray spectroscopy (EDS). The functional group changes were studied by Fourier transform infrared spectroscopy (FT-IR). The results show that the corrosive effect of sulfuric acid solution immersion on acrylic polyurethane is weak, while the hydrolysis of water molecules will lead to aging and failure of acrylic polyurethane. Sulfuric acid leads to the formation of zinc deficient areas in zinc-rich primers, which reduces the cathodic protection effect of zinc-rich primers. The service life of the zinc-rich primer/ Micaceous Iron Oxide/acrylic polyurethane composite coating is less than 150 h.

THE EFFECT OF THREE PRETREATMENTS ON BREAKING SEED DORMANCY OF BAOBAB (ADANSONIA DIGITATA L.)

Objective: Baobab (Adansonia digitata) is a native tree that is found in African savannas, it is a member of family ‘Malvaceae’. The tree is found in Nigeria, South Africa, Botswana, Namibia, Mozambique and in different regions of western Madagascar. Seed dormancy is the most limiting factor for some plants propagation. Dormancy allows seeds to separate from their mother plant and survive dispersal, over distance, and time before growth recommences. This study was aimed to determine the effect of three pre-treatments on breaking the seed dormancy of Adansonia digitata L., a multi-purpose and indigenously endangered tree.
 Methods: The study was carried out in the greenhouse of the Department of Biological Sciences, Federal University Dutsin-Ma, Nigeria. The three pre-treatments are: Soaking in hot water (100°C) for 5, 10, 15, and 20 min; and soaking in sulfuric acid (H2SO4) and hydrochloric acid (HCL) concentrations (100%, 75%, 50%, and 25%) for 5, 10, 15, and 20 min. Untreated seeds served as control. These were laid out in a complete randomized design with three replications. Data were collected on germination percentage, germination rate, day of emergence, and the average seedlings height.
 Results: The result showed that earliest mean days of emergence (7 days) were observed in seeds subjected to hot water treatment at 15 min. It also showed the highest rate of germination and percentage 6 (100%). On the other hand, the effect of acids (H2SO4 and HCL) pre-treatments on the seeds gave a fair result (16.66–33.33%), untreated seeds did not germinate.
 Conclusion: All the pre-treatments used in the study were found to be effective. However, soaking of seeds in hot water (100°C) pre-treatment for 15 min is recommended for breaking the seed dormancy of A. digitata.

Study on performance change of phenolic resin impregnated graphite in acid environment

Phenolic impregnated graphite is a new kind of material with higher corrosion resistance and thermal conductivity. In the chemical industry, it is often used to make containers and pipes containing strong acid and alkali medium. In this paper, the working conditions of impregnated graphite materials in the actual production were simulated in the laboratory, and the. mechanical properties and material characterization of impregnated graphite after soaking in sulfuric acid at different temperatures were compared. The results show that the tensile strength of phenolic resin impregnated graphite decreases with the increase of immersion temperature under the action of acid medium and temperature; the results of thermogravimetric analysis show that the inner phenolic resin expands and extrudes graphite particles to produce internal stress, and the graphite particles will fall off partially, but the chemical structure of phenolic resin does not change.

Effects and mechanism of dilute acid soaking with ultrasound pretreatment on rice bran protein extraction

This research focused on enhancing protein extraction from defatted rice bran (DRB) by using ultrasound combined with dilute sulfuric acid-soaking pretreatment. The extraction yield of protein was increased from 53.1% to 72.8% when the DRB was pretreated by ultrasound combined with 0.9% sulfuric-acid soaking at 90 °C. Untreated and pretreated DRB were then characterized by scanning electron microscope (SEM), fourier transform infrared (FTIR), and thermogravimetry analysis (TGA). The physicochemical analysis showed that combined pretreatment could significantly cause changes of chemical structure and reduce the thermalstability indicating the destruction of matix structue of DRB. This destruction would improve the accessibility of solvent to protein resulting in increase of protein extraction yield. Overall, the consequences of this investigation demonstrate that combined pretreatment is a comparatively effective process to extract protein from DRB, and the obtained results also prove a valuable insight into mechanism of protein extraction.

Seed anatomy and water uptake and their relation to seed dormancy of Ormosia paraensis Ducke

Abstract: Ormosia paraensis Ducke has ornamental seeds widely used in the manufacture of bio-jewels and wood used in the furniture industry. For seedling production, the information on its seed physiology is scarce. Thus, the aim of this study was to assess methods for breaking dormancy and relate them to integument structure and water uptake by O. paraensis seeds. Seed dormancy-breaking was performed by mechanical scarification and soaking in sulfuric acid for 0, 15, 30, 60, 120, and 240 minutes. Dormancy‐broken seeds were compared with intact seeds. Seed integument is formed by a cuticle (hydrophobic substances), epidermis (macroesclereids of the palisade layer,), hypodermis (osteosclereids), and parenchyma cells. Intact seeds did not absorb water after 72 hours of soaking. The highest percentages and rates of seed germination were observed in treatments with mechanical scarification and soaking in sulfuric acid for 60 or 120 minutes. Seed soaking in sulfuric acid (H2SO4 p.a. 98.08%) for 60 or 120 minutes or mechanical scarification are adequate to overcome physical dormancy associated with O. paraensis seed integument impermeability to water or gases.

Causes and Breaking of Seed Dormancy in Flowering Dogwood (Cornus florida L.)

Cornus florida seeds show strong dormancy. In this study, we investigated the causes of the dormancy by assessing the permeability of the stony endocarp, the germination of seeds after mechanical dissection, and the effect of endogenous inhibitors. Water uptake by intact and cracked seeds during imbibition showed that the endocarp formed a strong barrier for water absorption. Meanwhile, extracts from endocarp decreased the germination frequency of chinese cabbage seeds from 99.3% (control) to 2.7%. Therefore, the endocarp was the mechanical barrier and contained endogenous inhibitors for seed germination. However, the germination percentage of decoated seeds and dissected seeds with the exposed radicle were only 13.3% and 28.7%, respectively. It was found that the endosperm also played a role in seed dormancy. Extracts from endosperm decreased the germination frequency of chinese cabbage seeds from 99.3% (control) to 53.0%. By contrast, extracts from embryo did not affect the germination of chinese cabbage seeds. When tested with the excised embryos, germination percentage was up to 85.3% at the 16th day of incubation. Taking these results together, we concluded that the endocarp and endosperm were responsible for seed dormancy in C. florida. To break the seed dormancy of C. florida, stratification and soaking in sulfuric acid are the effective means. The highest germination frequency was achieved by immersing seeds in 98% sulfuric acid for 10 minutes, then soaking the seeds in 500 mg·L−1 gibberellic acid (GA3) for 72 hours before cold stratification at 5 °C for 60 days.

Preparation and physicochemical properties of soluble dietary fiber from orange peel assisted by steam explosion and dilute acid soaking

The coupled pretreatment of orange peel with steam explosion (SE) and sulfuric-acid soaking (SAS) was investigated to enhance the yield and improve the functionality of soluble dietary fiber (SDF). When orange peel was pretreated by SE at 0.8MPa for 7min, combined with 0.8% SAS, the content of SDF was increased from 8.04% to 33.74% in comparison to the control and SDF prepared with SE–SAS showed the high water solubility, water-holding capacity, oil-holding capacity, swelling capacity, emulsifying activity, emulsion stability and foam stability. SDF from orange peel treated by SE–SAS exhibited significantly (p<0.05) higher binding capacity for three toxic cations (Pb, As and Cu) and smaller molecular weight (Mw=174kDa). Furthermore, differential scanning calorimetry (DSC) measurement showed that SDF from orange peel treated by SE–SAS had a higher peak temperature (170.7±0.4°C) than that of the untreated sample (163.4±0.3°C). Scanning electron micrograph (SEM) images demonstrated that the surface of SDF from orange peel treated by SE–SAS was rough and collapsed. It can be concluded that SDF from orange peel treated by SE–SAS has the higher potential to be applied as a functional ingredient in food products.

A high-surface-area mesoporous sulfated nano-titania solid superacid catalyst with exposed (101) facets for esterification: facile preparation and catalytic performance

In this paper, a high-surface-area mesoporous sulfated nano-titania exposed with (101) facets was prepared by a simple hydrothermal method without any template followed by surface sulfate modification. The physicochemical properties of the as-prepared catalyst were well characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), Raman spectroscopy (Raman), Fourier transform infrared spectroscopy (FTIR), N2 adsorption–desorption isotherms, temperature programmed desorption of NH3 (NH3-TPD), X-ray photoelectron spectroscopy (XPS) and pyridine adsorption infrared spectroscopy. The BET surface area of sulfated nano-titania with exposed (101) facets was 121 m2 g−1. Well dispersed bidentate sulfate groups were linked to the exposed (101) facets of anatase nano-titania. Acid sites with moderate- and superacidic strength formed in the sulfated titania catalyst. Also, the as-prepared sulfated sample possessed both Lewis and Bronsted acid sites. The catalytic activity of sulfated nano-titania with exposed (101) facets was evaluated using the esterification reaction between acetic acid and n-butanol. It was found that the yield of butyl acetate increased to about 92.2% in the presence of the catalyst. Compared with the exposed (001) facets, the exposed (101) facets showed better catalytic activity of sulfated TiO2 in esterification. The effects of different reaction conditions were discussed in detail. Additionally, the as-prepared sulfated sample could be efficiently recycled and regenerated by simple soaking in sulfuric acid followed by calcination.

Preparation and functional properties of protein from heat-denatured soybean meal assisted by steam flash-explosion with dilute acid soaking

The combined pretreatment of heat-denatured soybean meal using steam flash-explosion (SFE) with sulfuric-acid soaking was investigated to prepare protein from soybean meal. When soybean meal was pretreated by SFE at 1.8MPa, 2.2MPa for 8min and at 2.0MPa for 8min and 10min, combined with 0.9% sulfuric-acid soaking, the extraction yield of protein increased to 67.72%, 70.54%, 69.47% and 71.21% respectively, compared to untreated soybean meal. Scanning electron micrograph of pretreated samples showed the structural disruption of soybean meal. After pretreatment, the protein yield was improved, while protein content of soy protein isolate (SPI) decreased slightly. The functional properties of SPI from pretreated soybean meal were all improved compared to untreated soybean meal and the relationship between functional properties and the changes of surface hydrophobicity of SPI was discussed. The emulsification properties and fat-binding capacity of pretreated SPI were superior to those of SPI prepared from white flakes.

Superação da dormência de sementes de Cupressuslusitanica Mill

Cupressuslusitanica Mill.is a multipurpose tree species with a high potential for wood production in Brazil. The main objective was to evaluate methods to dormancy break to promote seed germinationin C. lusitanica. The following treatments were used: T1 (intact seeds); T2 (soaking in water for 24 hours); T3 (soaking in water for 36 hours); T4 (stratification on 4 °C for 30 days); T5 (immersion in water for 8 hours + stratification on 4 °C for 30 days); T6 (immersion in water for 8 hours + stratification on 4 °C for 20 days); T7 (immersion for 12 hours + stratification on 4 °C for 20 days); T8 (soaking in hot water at 80ºC for 5 minutes); T9 (sulfuric acid soaking for 5 minutes). It was evaluated the percentage and germination speed (IVG). The resultsweresubmitted to ANOVA andmeanswere comparedusingthe Skott-Knott. The treatments T5, T2 and T7 showedhighergermination, and T7 higherspeedofgermination, thesecanberecommended for overcomingseeddormancyof C. lusitanica.

The effect of pre-sowing treatments and light on seed germination of Dracocephalum kotschyi Boiss: An endangered medicinal plant in Iran

The aim of this study was to investigate the effect of pre-sowing treatments and light on Dracocephalum kotschyi Bioss. seed germination. The following treatments were used: sandpaper; 3, 5 and 10 min soaking in sulfuric acid; 15 min in sodium hypochlorite; 24 h in water, hot water and boiling water; 50, 150, and 250 mg·L−1 of Gibberellic acid; 1000, 2000, 4000, and 6000 mg·L−1 of KNO3, and water (control). The germination rate, germination start (GS), mean germination time (MGT), time to 50% germination (T50) and cumulative germination were determined as germination indices. Root, shoot and seedling length and the vigor index (VI) were evaluated as growth factors at the end of the incubation period. Second experiment was carried out to study the effect of light on seed germination. It was observed that both the physical and chemical scarification methods were effective in enhancing D. Kotschyi seed germination and growth. In the first stage, up to day 20 SA (10 min) and sandpaper scarification treated seed had shown germination more than 70% whereas control seeds did not begin germination until day 20. The highest germination rate was observed with sandpaper (1.77 units) and SA (1.56 units) in compare with other treatments (less than 0.9 units). Also the highest vigor index was found in SA- and sandpaper-treated seeds and the lowest occurred in sodium hypochlorite treatments. The other results showed that light was more effective than darkness for seed germination.

SO42−/ZrO2–titania nanotubes as efficient solid superacid catalysts for selective mononitration of toluene

SO42 −/ZrO2–titania nanotubes–X (SO42 −/ZrO2–TNTs–X; X of Ti/Zr) solid superacid catalysts with different atom ratios (Ti/Zr) were successfully prepared. The SO42 −/ZrO2–TNTs–2 (Ti/Zr of 2) have a specific surface area of 394 m2/g and an acid intensity of 1.839 mmol/g. The SO42 −/ZrO2–TNTs–2 show excellent selectivity (p/o of 3.34) and activity (yield of 98%) in the selective mononitration of toluene. Importantly, the SO42 −/ZrO2–TNTs–2 can be efficiently recycled and regenerated by simple sulfuric acid soaking.

Tratamentos para acelerar a germinação e reduzir a deterioração das sementes de Ormosia nitida Vog

O trabalho foi conduzido no Laboratório de Sementes do Centro de Ciências Agrárias da Universidade Federal do Espírito Santo, objetivando avaliar tratamentos para acelerar a germinação e reduzir a deterioração de sementes de Ormosia nitida. Foram conduzidos dois experimentos em delineamento inteiramente casualizado, com quatro repetições. No primeiro estudo, feito em papel substrato, os tratamentos foram sementes intactas, escarificação mecânica e escarificação química com H2SO4 durante 10 min. No segundo estudo feito em placas de Petri, os tratamentos utilizados foram sementes intactas (controle); escarificação mecânica; escarificação mecânica + pré-embebição por 24 horas; H2O2 no substrato; e escarificação química com H2SO4 durante 1, 5, 10,15, 20, 25 e 30 min. Foram avaliados o vigor, através do índice de velocidade de germinação, e a germinação, através da porcentagem de plântulas normais. A todos os tratamentos pré-germinativos foram apresentados respostas positivas na porcentagem e velocidade de germinação em relação ao controle. A escarificação mecânica e o H2O2 no substrato proporcionaram aumento significativo na velocidade e porcentagem de germinação das sementes, com redução da deterioração.

Protonated Sites on Sulfate-Promoted Zirconium Oxide Catalysts: A Fourier Transform-IR, Thermal Analysis, and Solid State1H NMR Study

A series of sulfate-promoted ZrO2solid acid catalysts samples were prepared, each sample differing only in the pH of the sulfuric acid soaking step of the synthesis procedure. Fourier-transform infrared (FTIR) spectra and thermal weight-loss measurements (as measured by thermal gravimetric analysis (TGA)) indicate that the pH of the sulfuric acid soaking solution influences the number of surface proton sites. The activity of sulfate-promoted ZrO2in catalyzing the isomerization of n-butane to iso-butane at 220°C and the surface area of the calcined catalyst are also found to depend on the soaking solution pH, with maximum surface areas and activities observed between pH 6 and pH 9. Proton nuclear magnetic resonance (NMR) chemical shifts measured using combined rotation and multiple pulse spectroscopy indicate that the sulfating step produces proton species that are more acidic than proton sites on the nonsulfated support. The proton NMR spectra of these samples consist of at least two overlapped, but distinct, resonances that can be separated on the basis of a large disparity in spin-lattice (T1) relaxation times. By comparing the experimental spectra with a series of simulated spectra, the long T1component has been assigned to a discrete three- or four-proton site that includes one water molecule, and the short T1component to an ill-defined cluster of protons. Variable-temperature NMR lineshape data also suggest that the protons are in rapid motion on the sulfate-promoted zirconium oxide surface.

Improving germination of hop-hornbeam seeds

The effects of stratification, clipping, sulfuric acid soaking, and pericarp removal on the germination of hop-hornbeam (Ostryavirginiana [Mill.] K. Koch) seeds were investigated. Untreated seeds failed to germinate. Removing the pericarp produced 34–37% germination. Gibberellic acid (GA3) improved germination of intact seeds, but was most effective for seeds with pericarps removed, resulting in 76–80% germination. Although stratification of intact seeds for 3 months produced 15% germination, a combination of pericarp removal, GA3 treatment, and stratification was best, resulting in 81% germination. For seed testing, the pericarps should be removed and seeds treated with 500 mg/L GA3 for 24 h at 20 °C. Germination at 20 °C with continuous light appears to be a good test condition.