H2SO4 Treatment Research Articles

Influence of Green Synthesized Silver and Zinc Nanoparticle on Seed Quality Attributes in Red Sander (Pterocarpus santalinus Linn.)

Red Sanders (Pterocarpus santalinus), or Rakta chandana, is an endangered tree native to the Southern Indian Peninsula, valued for its medicinal and dye properties. However, its germination is hindered by a hard seed coat, phenolic compounds and hormonal imbalances. Nanotechnology in forestry enhances product innovation, paper processes and sustainability through plant-based nanoparticle biosynthesis. The experiment used a completely randomized design (CRD) with three replications and evaluated seven presowing treatments: T1 (AgNPs at 1000 ppm for 24 hours), T2 (ZnNPs at 2000 ppm for 24 hours), T3 (Conc. H2SO4 for 12 minutes), T4 (NaDC 500 ppm), T5 (Dewinging), T6 (soaking in hot water at 100°C for 5 minutes) and T7 (control). The results indicated that seeds treated with ZnNPs at 2000 ppm (T2) exhibited highest germination rate (56%), germination speed (1.04), root length (17.05 cm), shoot length (16.33cm) and highest dry weight (6.22 g) and highest seedling vigour Index-I (1869). In comparison H2SO4 treatment (T3) delivered 51.67 per cent germination and a speed of germination (0.95), with root length (15.28 cm), shoot length (16.22 cm), dry weight (5.24 g) and seedling vigour Index (1628) slightly lower but still significant. The control (T7) had the lowest performance with 31 per cent germination, a speed of 0.36, root length (15.28 cm), shoot length (16.22 cm), lower dry weight (1.63 g) and the lowest Seedling Vigour Index (649). Overall, ZnNPs at 2000 ppm (T2) were the most effective in enhancing germination, seedling growth and overall vigour in Red sanders.

Enhanced Microstructural Uniformity in Sulfuric-Acid-Treated Poly(3,4-Ethylenedioxythiophene):Poly(Styrene Sulfonate) Films Using Raman Map Analysis.

Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films have emerged as potential alternatives to indium-tin oxide as transparent electrodes in optoelectronic devices because of their superior transparency, flexibility, and chemical doping stability. However, pristine PEDOT:PSS films show low conductivities because the insulating PSS-rich domains isolate the conductive PEDOT-rich domains. In this study, the conductivities and corresponding spatially resolved Raman properties of PEDOT:PSS thin films treated with various concentrations of H2SO4 are presented. After the PEDOT:PSS films are treated with the H2SO4 solutions, their electrical conductivities are significantly improved from 0.5 (nontreated) to 4358 S cm-1 (100% v/v). Raman heat maps of the peak shifts and widths of the Cα═Cβ stretching mode are constructed. A blueshift and width decrease of the Cα═Cβ Raman mode in PEDOT are uniformly observed in the entire measurement area (20 × 20 µm2), indicating that microstructural transitions are successfully accomplished across the area from the coiled to linear conformation and high crystallinity upon H2SO4 treatment. Thus, it is proved that comprehensive Raman map analysis can be easily utilized to clarify microstructural properties distributed in large areas induced by various dopants. These results also offer valuable insights for evaluating and optimizing the performance of other conductive thin films.

Studies in the seed ecology and seedling Phenology of Andrographis paniculata (Brum. f.) Wall. ex Ness in West Bengal, India

Andrographis paniculata (Brum. f.) Wall. ex Nees is an important medicinal plant of tropical Asia and has been used widely for a long time for different clinical ailments. Despite profuse flowering and a high percentage of fruit set,the number of seedlings in the natural population is the bare minimum. Knowledge regarding the seed ecology and seedling phenology of A. paniculata, is needed to formulate conservation strategies for the species. Therefore, a detailed study on seed ecology and seedling phenology has been conducted. During seed ecological studies,seed production, seed-set percentage, seed-ovule ratio, mechanism of seed dispersal, seed structure along with germination status, viability, dormancy and its breaking, and percentage of moisture content loss have been studied. Seeds exhibit some kind of dormancy [germination percentage (GP) = 28.51 ± 0.98, mean germination time (MGT) = 33.07± 0.89 days, and germination index (GI) = 0.73 ± 0.08] which can be effectively overcome through acid scarification using H2SO4 and hot water treatment. The species shows epigealphanerocotylar germination. The hypocotyls exhibit rapid growth, and cotyledons emerged at 7.52±0.27 TARA (Time After Radicle Appearance in days). Seedling is characterised by a thickened, hairy hypocotyl, a distinct collet, a pair of paracotyledons, and three pairs of eophylls in opposite decussate phyllotaxy. The studies on seed ecology and seedling phenology play a significant role in understanding how the shortening of the inception period enhances the germination status, and distinct seedling morphology provides the opportunity to formulate conservation strategies in their wild habitat.

Enhanced resistance to K poisoning and SO2 & H2O on Ce0.63TiOx catalyst by sulfation treatment

At present, alkali metal poisoning is still a problem should be solved for catalyst deactivation of selective catalytic reduction (SCR) of NOx with NH3. In this work, the Ce0.63TiOx (CT) catalyst was synthesized by hydrothermal method and it was used the wet immersion method of H2SO4 treatment to obtain CT-xwt%S catalysts. The NH3-SCR denitrification (de-NOx) activity, resistance to SO2 & H2O and K-resistant properties of catalysts were studied, and the catalysts were characterized by N2 physical adsorption, XRD, Raman spectroscopy, TEM images, NH3-TPD, H2-TPR, NO-TPD, XPS, IR spectra of pyridine adsorption and in situ DRIFTS. The experimental results show that CT-0.5 wt%S catalyst has stronger resistance to K, H2O and SO2 than CT catalyst. Although the redox performance of the CT-0.5 wt%S catalyst is reduced, the sulfation treatment increased the surface acidity, which promoted the adsorption and activation of ammonia. This facilitates the high-temperature activity of CT-0.5 wt%S catalyst and enhances the K resistance of the catalyst. Satisfyingly, the strong interaction between K species and SO42− in the CT-0.5 wt%S catalyst protects the active sites to K poisoning. In addition, in situ DRIFTS results indicate that K poisoning depletes the acid sites, and the rich acid sites of CT-0.5 wt%S catalyst can be used as sacrifices site to coordinate with K, thus weakening the influence of K poisoning on catalyst. This work provides a new strategy for designing NH3-SCR catalysts with excellent resistance to K.

Degradation selectivity for bamboo fiber and parenchyma lignin-carbohydrates complexes (LCC) esters

The degradation of lignin-carbohydrate complex (LCC) esters has been proven to be crucial for the selective separation of lignocellulosic components. This study utilized Raman microspectroscopy to image the preferential degradation of lignin and LCC esters from the bamboo wall during successive NaOH (0.2 to 5.0 % w/w), H2SO4 (1 to 8 % v/v), and NaClO2 (5 to 20 min) treatments. Raman imaging showed that lignin and LCC esters were selectively removed from the middle lamella of fibers and the secondary wall of parenchyma during NaOH and NaClO2 treatments. In contrast, H2SO4 primarily caused the simultaneous removal of lignin and LCC esters from the fiber wall under harsh conditions (8 %), while the middle lamella of parenchyma was less affected, both morphologically and topochemically. Raman spectral analysis indicated that the band intensity at 1605 cm−1 for lignin and at 1173 cm−1 for LCC esters decreased by >87.0 % in the highly lignified parenchyma secondary wall after a 5.0 % NaOH treatment, while the decrease was <67 % in the fiber wall. Interestingly, a strong linear correlation was observed between LCC esters and carbohydrates in the parenchyma (R2 > 0.912). These findings provide important insights into the graded and classified utilization of bamboo resources.

Seed Dormancy Class and Germination Characteristics of Prunus spachiana (Lavallée ex Ed.Otto) Kitam. f. ascendens (Makino) Kitam Native to the Korean Peninsula.

Prunus spachiana (Lavallée ex Ed.Otto) Kitam. f. ascendens (Makino) Kitam leaves exert natural anti-inflammatory effects by inhibiting nitric oxide formation. P. spachiana flowers bloom earlier than other Prunus spp. and thus could serve as a valuable resource for the horticulture and pharmaceutical industries. However, its seed dormancy class and germination traits remain uncharacterized. Thus, this study aimed to characterize the seed dormancy and germination of P. spachiana. Imbibition, phenological, and move-along experiments were performed, and the effects of H2SO4 treatment, hormone soaking, warm/cold stratification, and endocarp removal on germination were explored. Observation revealed that ripe seeds of P. spachiana contain developed embryos and are water permeable. Radicle and shoot emergence began in March and April, respectively, under natural conditions in the year following production. No seed germination was observed after 30 days of incubation at 4, 15/6, 20/10, or 25/15 °C under light/dark conditions, indicating the physiological dormancy of the seeds. Germination increased with prolonged stratification and was affected by incubation temperature. Seed scarification by H2SO4 and soaking with gibberellic acid (GA3) and fluridone were ineffective in breaking dormancy. However, GA3 soaking of the seeds after endocarp removal effectively induced germination (100%). These results indicate that P. spachiana seeds exhibit intermediate physiological dormancy.

Development and validation of an acid/alkaline digestion method for efficient microplastic extraction from wastewater treatment plant effluents: Sulfuric acid concentration and contact time do matter

Accurate analysis of microplastic particles (MPs) in environmental samples requires removal of interferences during sample preparation. Wastewater samples are interference-rich and thus particularly challenging, with concentrated sulfuric acid currently deemed impractical as a reagent. Therefore, this study aimed to establish a straightforward, effective, and safe method employing concentrated sulfuric acid and potassium hydroxide to eliminate interferents from effluent samples obtained from wastewater treatment plants (WWTPs). We found that 80 % sulfuric acid at room temperature with a brief contact time of 5 min was viable through a qualitative spot test involving 37 plastics categorized into three types (I, II, and III) based on their polymer structure's oxygen position. A quantitative assessment revealed that treatments involving H2SO4 and KOH (20 %, 24 h, 48 °C), either separately or in combination, had no discernible physical impact on the overall plastics, except for a subtle one for Type III plastics (e.g., nylon and PMMA) known to be labile under harsh pH conditions. This acid/alkaline digestion (AAD) method, incorporating such conditions for H2SO4 and KOH treatments, yielded a high mass removal efficacy (97.8 ± 2.4 %, n = 13) for eliminating natural particle interferents for primary, secondary, and tertiary effluent samples. Furthermore, the AAD method allowed for the determination of MPs in effluents with high surrogate particle recoveries (e.g., 95.1 % for larger than 500 μm size fraction). This method is readily adaptable to create appropriate protocols for different types of environmental matrices.

Seed dormancy mechanism and dormancy-breaking methods in wild raspberry (Rubus fraxinifolius Poir.)

Raspberries are subtropical plants that contain high levels of vitamin C, antibacterial and anti-inflammatory. They can potentially be developed as horticultural and medicinal plants. Dormancy is a challenge in the cultivation of raspberries (Rubus fraxinifolius Poir.). This study was conducted as two separate experiments. The first experiment aimed to identify the dormancy mechanism of R. fraxinifolius seed. In a two-factor factorial design, the first factor was seed storage, as unstored and three-month-stored, and the second factor was chemical-immersed treatment consisting of control, H2SO4, acetone, GA3, KNO3, H2SO4-GA3, acetone-GA3, H2SO4-KNO3, acetone-KNO3. The second experiment was aimed at determining dormancy-breaking methods for R. fraxinifolius seeds. In main plots were filter paper and cocopeat germination substrates. The subplots included control, immersed with distilled water, H2SO4, ultrafine bubble water, and temperature treatment at −80 °C, 50 °C, and 70 °C. The germination of unstored and three-month-stored seeds increased after H2SO4 treatment (36 to 82% and 82 to 94%, respectively). Seed germination increased after three months of storage. There was an increase in cytokinin hormone levels along with germination enhancement. The seeds went into physical dormancy because their seed coat was hard, and they went into physiological dormancy because of low cytokinin concentration. Stratification at 50 °C increased germination (78.5 to 93.0%), reduced dormancy intensity (15 to 6.5%), and increased the percentage of the speed of germination (1.99 to 3.12 ) on filter paper substrate.

Effects of H2SO4, GA3, and cold stratification on the water content, coat composition, and dormancy release of Tilia miqueliana seeds

IntroductionTilia miqueliana is an endemic species whose population is declining. The permeability barrier and mechanical constraint of the pericarp (seed coat) are important causes of its seed dormancy. Although there has been considerable research on this subject, questions remain regarding how the permeability barrier and mechanical constraint of the seed coat are eliminated during dormancy release and how water enters the seed. Therefore, protecting the species by improving its germination/dormancy breaking in the laboratory is urgentMethodsIn this study, the changes in the cellular structure, mechanical properties, and components of the Tilia miqueliana seed coat after an H2SO4-gibberellic acid (GA3) treatment were analyzed during dormancy release. Various analyses (e.g., magnetic resonance imaging, scanning electron microscopy, and paraffin section detection) revealed the water gap and water channel.ResultsThe H2SO4 treatment eliminated the blockage at the micropyle and hilum of the seeds. Water entered the seeds through the water gap (micropyle) rather than through the hilum or seed coat, after which it dispersed along the radicle, hypocotyl, and cotyledon to the endosperm. During the cold stratification period, the cellular structure was damaged and an increasing number of holes appeared on the inner and outer surfaces of the seed coat. Vickers hardness tests showed that GA3 decreased the seed coat hardness. Additionally, the seed coat lignin and total phenol contents continuously decreased during the cold stratification period. Notably, the Liquid chromatography–mass spectrometry (LC–MS) analysis of the seed coat detected polyethylene glycol (osmoregulator), which may have destabilized the water potential balance inside and outside the seed and increased the water content to levels required for germination, ultimately accelerating seed dormancy release.DiscussionThis sophisticated and multi-level study reveals how H2SO4 and GA3 eliminate the permeability barrier and mechanical constraints of the seed coat during dormancy release of Tilia miqueliana seeds. This will be beneficial to artificially assist the natural regeneration and population expansion of Tilia miqueliana.

Pengujian Lignoselulosa Tandan Kosong Kelapa Sawit dengan Waktu Delignifikasi H2SO4 Menggunakan Uap Bertekanan

Oil palm empty fruit bunches (EFB) are the most abundant solid waste from the palm oil industry and are underutilized, even though they have the potential to become industrial raw materials because they contain three fractions, namely cellulose, hemicellulose, and lignin. This research was carried out using the steam method using 1 molar sulfuric acid with concentrations of 6.4%, 7.6%, and 8.7%. The delignification temperature was measured at 120 oC and with different delignification times of 60 minutes, 90 minutes, and 120 minutes. The best treatment with 1 M H2SO4 concentration and heating time for hemicellulose was the treatment with 8.7% H2SO4 concentration and 90 minutes of heating time. The best treatment with 1 M H2SO4 concentration and heating temperature for cellulose was found to be 6.4% H2SO4 concentration with 90 minutes of heating time. The best treatment with a 1 M H2SO4 concentration and heating temperature for lignin was the 6.4% H2SO4 treatment with 90 minutes of heating time.

H2SO4-treated and raw watermelon waste bio-briquettes: Comparative, eco-friendly and machine learning studies

As the world faces the challenges of climate change and diminishing fossil fuel reserves, researchers and scientists have increasingly explored the use of plant waste as a viable biofuel source. Among the various plant waste materials, watermelon peel waste, which is typically discarded during processing of beverages or consumption, has gained attention due to its high cellulose content. This study focuses on comparing the properties and environmental sustainability of watermelon peel waste biofuel treated with H2SO4 to raw watermelon peel waste biofuel. From a sustainable energy perspective, maximizing the amount of energy recovered from solid bio-fuel is a critical consideration. Thus, the adaptive neuro-fuzzy inference system (ANFIS) was developed in this study to predict the calorific value (a significant indicator of the energy values) of both H2SO4-treated and raw watermelon waste briquettes while providing useful insights into the effect of the H2SO4 treatment on the energy value of the briquette. The results indicate that the watermelon peel waste treated with acid performed better compared to the untreated sample. It exhibited a higher mean fixed carbon content and calorific value of 22.70 ± 0.16 % and 14.62 ± 0.21 MJ/kg, respectively. Additionally, the treated sample showed a significantly lower mean ash content of 11.20 ± 0.13 %. The EDXRF analysis revealed that the treated samples had reduced proportions of Nickel, Sulfur, and Arsenic, along with a higher carbon count. The FTIR analysis confirmed surface modification in the acid-treated watermelon peel waste (ATWB) through a decrease in lignin content (8.41 ± 0.014 wt%). It also identified a shift in the C-O vibrational stretch from 1021 cm−1 in the untreated watermelon peel waste (UWB) sample to 1028 cm−1 in the ATWB. Moreover, the SEM micrographs displayed a well-packed surface, indicating a reduction in fiber diameter (porosity) in the treated sample. The recorded RMSE, MAD, MAE, and MAPE values of the model are 0.1427, 0.0883, 0.1246 and 1.2313 at the training phases and 0.1581, 0.0997, 0.1484, and 1.9011 at the testing. The regression plot of calorific value with a R2-value of 0.9065, depicts a strong positive linear relationship between the predicted and real values. This outcome of the study suggests an improvement in thermal energy release and enhanced combustibility while the ANFIS model's ability to optimize energy values aligns with the objective of developing eco-friendly bio-briquettes.

Macro-micro structure engineering of bio-spore-derived hard carbon as an efficient anode in sodium ion batteries

Elucidating the macro–micro structures of hard carbon is critical to address the issues of deficient Na+ storage capacity at the anode in Na+ ion batteries. Herein, hard carbon materials with various macro–micro structures were synthesized by pyrolyzing the spores of Calvatia Gigantea (SCG) as precursors treated by a coupling strategy with a dehydration process via concentrated H2SO4 treatment and the removal of inherent Si species by NaOH. Research results demonstrate that the process of concentrated H2SO4 pretreatment can induce the collapse of original hollow spheres of SCG to form specific hard carbon hollow hemispheres, while the NaOH leaching treatment can further modulate the microstructures of hard carbon. Attributed to the unique characteristics of specific hollow hemi-spherical morphology, ultra-low surface area, rich closed pore and appropriate layer spacing, the hard carbon not only exhibits outstanding specific capacity up to 500 mA h g−1 with a high initial Coulombic efficiency of 90.23 % for Na+ storage, but also presents excellent high-rate capability with 254.88 mA h g−1 at 5 A/g and cycling stability with a capacity retention rate of ≥80 % after 4102 cycles. The outstanding performance exceeds the vast majority of reported hard carbons for Na+ storage. Theoretical analysis further reveals that increasing closed pores constructed by distorted graphite-like layers together with proper lattice distance and curvature in hard carbon is essential to improve Na+ storage capacity. The coupling strategy of tuning the morphologies and microstructures of spore-derived hard carbon in the work provides new insights for developing advanced hard carbon with efficient Na+ storage performance.

Investigating the influence of different pretreatment methods on the morphological structure of Arachis hypogea shells

This study investigates the effect of acid, alkali, and thermal pretreatment methods on the morphological structure of Arachis hypogea shells. Arachis hypogea shells were pretreated with H2SO4, NaOH, and conventional thermal treatment. The effect of the pretreatment on the microstructure, crystallinity and functional groups was examined using Structural Electron Microscopy, X-ray Diffraction, and Fourier Infra-red Transform (FTIR). The results showed that the different pretreatment techniques have varying effects on the microstructure of the feedstock. The crystallinity index of Arachis hypogea shells differs with treatment, and the FTIR results indicated that the functional groups were detected at different wavenumbers.

Highly Conductive and Reusable Cellulose Hydrogels for Supercapacitor Applications.

We report Na-Alginate-based hydrogels with high ionic conductivity and water content fabrication using poly (3,4-ethylene dioxythiophene) (PEDOT): poly (4-styrene sulfonic acid) (PSS) and a hydrogel matrix based on dimethyl sulfoxide (DMSO). DMSO was incorporated within the PEDOT:PSS hydrogel. A hydrogel with higher conductivity was created through the in-situ synthesis of intra-Na-Alginate, which was then improved upon by H2SO4 treatment. Field emission scanning electron microscopy (FESEM) was used to examine the surface morphology of the pure and synthetic hydrogel. Structural analysis was performed using Fourier-transform infrared spectroscopy (FTIR). Thermogravimetric analysis (TGA), which examines thermal properties, was also used. A specific capacitance of 312 F/g at 80 mV/s (energy density of 40.58 W/kg at a power density of 402.20 W/kg) at 100 DC mA/g was achieved by the symmetric Na-Alginate/PEDOT:PSS based flexible supercapacitor. The electrolyte achieved a higher ionic conductivity of 9.82 × 10-2 and 7.6 × 10-2 Scm-1 of Na-Alginate and a composite of Na-Alginate/PEDOT:PSS at 25 °C. Furthermore, the supercapacitor Na-Alginate/PEDOT:PSS//AC had excellent electrochemical stability by showing a capacity retention of 92.5% after 3000 continuous charge-discharge cycles at 10 mA current density. The Na- Alginate/PEDOT:PSS hydrogel displayed excellent flexibility and self-healing after re-contacting the two cut hydrogel samples of electrolyte for 90 min because of the dynamic cross-linking network efficiently dissipated energy. The illumination of a light-emitting diode (LED) verified the hydrogel's capacity for self-healing.

Touch wood: Conversion of lignin to dicarboxylic acids using biochar-based solid-acid photo-Fenton catalysts

The depolymerization of lignin into dicarboxylic acids (DCA) by the Fenton oxidation process is a promising approach to valorising lignin. However, Fenton oxidation is challenging due to the demand for acidic reaction conditions and homogeneous Fe2+ catalysts, which cannot be recovered. Herein, we fabricated a biochar-based solid-acid catalyst (SBC) from the pyrolysis of rice straw biomass followed by H2SO4 treatment. This novel catalyst achieved an enhanced catalytic performance in the activation of H2O2 under circumneutral pH, visible-light irradiation and Fe-free conditions. Under optimum conditions, a cumulative yield of 40.1 μ mol. gcat−1. h−1 of malonic, maleic, fumaric, succinic and gallic acid was obtained using 40 mM H2O2, 1 g/L catalyst loading and 4 h reaction time, which is comparable to yields reported in the literature under elevated temperatures and pressures. The activity of SBC stems from the synergy of oxygenated surface functional groups and persistent free radicals (PFRs), which can chemisorb and subsequently activate H2O2 and dissolved O2 to yield •OH and 1O2. Addition of NaN3 scavenger for 1O2 enhanced the cumulative DCA yields to 282.4 μ mol. gcat−1.h−1, suggesting that 1O2 is the main reactive oxygen species in the reaction. Finally, the SBC catalysts remained stable at the said reaction conditions and could be recycled without significant deactivation. After five cycles, the lignin conversion and cumulative DCA yields decreased by 19.7% and 23% respectively. These results show that Fe-free, visible-light Fenton-like catalytic oxidation of lignin with acid-modified biochars is a promising way to produce high-value platform chemicals.

A self-powered ultraviolet photodetector based on TiO2 nanoarrays and poly(3,4-ethylenedioxyselenophene) with the enhanced performance by pyro-phototronic effect

Pyro-phototronic effect plays an important role in improving the photodetection performance of ultraviolet (UV) photodetectors (PDs). Here, a novel pyro-phototronic effect between TiO2 nanoarrays (TiO2 NRs) and the conducting polymer poly(3,4-ethylenedioxy selenophene) (PEDOS) is applied to fabricate a self-powered UV PD with the enhanced photodetection ability. The self-powered p-n heterojunction UV PD is fabricated by a face-to-face hybrid of acid (HCl and H2SO4)-treated TiO2 NRs with PEDOS. Interestingly, a pyro-phototronic effect is found between TiO2 NRs/FTO and PEDOS/FTO, and the acid treatment of TiO2 NRs can dramatically enhance the pyro-phototronic effect. H2SO4 treatment can improve the p-n heterojunction, while HCl treatment can increase carrier concentration due to the introduction of surface oxygen vacancies on the surface of TiO2 NRs. Under UV light illumination and 0 bias voltage, the rise time (Trise) and fall time (Tfall) of UV PD from the face-to-face hybrid of PEDOS/FTO with TiO2(HCl)/FTO are 0.080 s and 0.079 s, while the responsivity (R) and detectivity (D*) are 58.706 mA/W and 3.627 × 1011 Jones, respectively. The face-to-face fabrication of UV PDs and the matching of the energy levels between PEDOS and TiO2 NRs cause the pyro-phototronic effect due to temperature change and pyroelectric effect of TiO2 NRs under the UV light illumination. This work gives a new idea to generate pyro-phototronic effect between TiO2 NRs and conducting polymers for application in UV PDs field.

Optimization of electroless Ni B-nanodiamond coating corrosion resistance and understanding the nanodiamonds role on pitting corrosion behavior using shot noise theory and molecular dynamic simulation

This study aimed to optimize the corrosion resistance of the electroless NiB-nanodiamond coating using a response surface method (RSM) by changing the electroless bath parameters and understand the role of nanodiamonds on pitting corrosion behavior using linear polarization, and electrochemical noise measurements as well as molecular dynamics simulation. The structure of optimized coating and nanodiamonds (ND) were characterized using FTIR, XPS, GDOES, SEM, and TEM. The stability of nanodiamonds was improved through acid treatment in HNO3 and H2SO4 (volumetric 1:3) solution. The quadratic model for predicting the polarization resistance of coatings based on the designed experiments was proposed with an accuracy of 92.85 %. Calculation of the pit initiation rate based on Weibull probability plots and probability of non-exceedance of pit diameter from shot noise theory reveals that the pit nuclei form at almost the same rate for NiB and NiB-nanodiamond coating, however, in NiB-nanodiamond coating the growth of pits is stopped. The molecular dynamic simulation showed that chloride ions forms weak chemical bonding on the ND surface than nickel due to the lower adsorption energy between the nanodiamonds surface and chloride ions which block localized corrosion attack.

Rapid and selective screening of organic peroxide explosives using acid-hydrolysis induced chemiluminescence

Organic peroxide explosives (OPEs) are unstable, non-military, contemporary security threats often found in improvised explosive devices. Chemiluminescence (CL) can be used to detect OPEs, via radical formation consisting of peroxide moieties (-O-O-) under acidic conditions. However, selectivity for specific OPEs is hampered by the ubiquitous background of H2O2. Herein, we report the differentiation of hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP), and methyl ethyl ketone peroxide (MEKP) by specific flow injection analysis–CL (FIA-CL) signal profiles, after H2SO4 treatment. The radical degradation pathway of each structure, and its corresponding FIA-CL profile, was explored using mass spectrometry to reveal the rapid loss of -O-O- from TATP and HMTD structures, while MEKP formed CL signal-sustaining oligomers, as opposed to the immediate attenuation of H2O2. The CL response for OPEs in an aqueous media, measured via the described FIA-CL method, enabled ultra-trace limits of detection down to 0.40 μM for MEKP, 0.43 μM for HMTD, and 0.40 μM for TATP (combined linear range 1–83 μM with 95% confidence limit, n = 12). Expanded uncertainties of measurement (UM) of MEKP = ±0.98, HMTD = ±1.03, and TATP = ±1.1 (UM included probabilities of false positive and false negative as well as standard deviations of % recoveries and limit of detections of OPEs). Direct aqueous sample introduction via FIA-CL thus offers the prospect of rapid and selective screening of OPEs in security-heightened settings (e.g., airports), averting false positives from more ubiquitous H2O2.

Effect of Pre-sowing Treatment to Break the Seed Dormancy and Seed Germination of Melia composita under Laboratory Conditions

Melia composita (Burma dek) is one of the multipurpose fast growing tree species applicable for the agri-silviculture system. In northern India, due to its fast growing and short rotation nature it has developed one of chosen tree species by the farmers under agroforestry. Melia composita occurs mostly in tropical moist and dry deciduous forest of Himalayas. The seed have Hard endocarp and therefore quite difficult to germinate. There are different types of seed dormancy and it helps in find out the better pre-sowing treatment to assure early and uniform germination of seeds. This leads to minimize the cost of large scale seedlings production. The present study was conducted at Laboratory of Seed Science and Technology, CCS Haryana Agricultural University during 2019 to evaluate the “Effect of pre-sowing treatments on seed germination of Melia composita”. Five pre-sowing treatments viz., normal water soaking (24, 48 and 72hr), conc. H2SO4 (5, 10 and 15 min.), cow dung slurry (5, 10 and 15 days), boiling water (5, 10 and 15 min.), mechanical scarification + GA3 (100 ppm) (8, 16 and 24hr). In laboratory conditions, maximum germination (64.67 %) and seed viability (74.67%) were recorded in concentrated H2SO4 treatment at 15 minute, whereas maximum root length (7.54 cm), shoot length (16.72 cm), root: shoot ratio and seedling dry weight (0.65g) were recorded in mechanical scarification + GA3 (100 ppm) at 24 hr.

Insights into sodium-ion batteries through plateau and slope regions in cyclic voltammetry by tailoring bacterial cellulose precursors

Hard carbon with high capacity with fast sodium storage is the most promising anode material for sodium-ion batteries. Many works have been made on improving the plateau and slope capacity of hard carbon in order to obtain high energy-power density sodium-ion batteries. This work explores sodium ions storage behaviors in porous carbon materials from the perspective of plateau and slope regions in cyclic voltammetry through tailoring the bacterial cellulose precursor with sulfuric acid and two-step carbonization. The influences of structure parameters including carbon layer distance, oxygen content, graphitization degree, and length and thickness of graphite crystallite help understand the strategies for improving the plateau and slope capacity. The results indicate the pre-carbonization of bacterial cellulose precursors via H2SO4 treatment introduces oxygen groups in both of bacterial cellulose matrix and bacterial cellulose derived carbon, which is beneficial for improving the slope and plateau capacity. The obtained bacterial cellulose-based carbon material with rational closed pores and micro-mesoporous structure shows a good discharging capacity of 420.6 mA h g−1 at 0.03 A g−1, and the enhanced plateau-slope capacity is 255.2 -167.1 mA h g−1 at 0.03 A g−1, respectively.