Degradation Of Acetic Acid Research Articles

Microbiota diversity of three Brazilian native fishes during ice and frozen storage

This study aimed to assess the bacterial microbiota involved in the spoilage of pacu (Piaractus mesopotamics), patinga (female Piaractus mesopotamics x male Piaractus brachypomus), and tambacu (female Colossoma macropomum × male Piaractus mesopotamics) during ice and frozen storage. Changes in the microbiota of three fish species (N = 22) during storage were studied through 16S rRNA amplicon-based sequencing and correlated with volatile organic compounds (VOCs) and metabolites assessed by nuclear magnetic resonance (NMR). Storage conditions (time and temperature) affected the microbiota diversity in all fish samples. Fish microbiota comprised mainly of Pseudomonas sp., Brochothrix sp., Acinetobacter sp., Bacillus sp., Lactiplantibacillus sp., Kocuria sp., and Enterococcus sp. The relative abundance of Kocuria, P. fragi, L. plantarum, Enterococcus, and Acinetobacter was positively correlated with the metabolic pathways of ether lipid metabolism while B. thermosphacta and P. fragi were correlated with metabolic pathways involved in amino acid metabolism. P. fragi was the most prevalent spoilage bacteria in both storage conditions (ice and frozen), followed by B. thermosphacta. Moreover, the relative abundance of identified Bacillus strains in fish samples stored in ice was positively correlated with the production of VOCs (1-hexanol, nonanal, octenol, and 2-ethyl-1-hexanol) associated with off-flavors. 1H NMR analysis confirmed that amino acids, acetic acid, and ATP degradation products increase over (ice) storage, and therefore considered chemical spoilage index of fish fillets.

Evidence of the Relationship between the Oxygen Radical Absorbance Capacity (ORAC) and the Potential Exposure of White Wines to Atypical Aging (ATA).

Atypical aging (ATA) is a well-known wine defect that leads to unacceptable off-odors of wet mop, soap, waxy, furniture varnish, and dish rag. The main compound that is responsible for these undesired scents, 2-aminoacetophenone (AAP), results from the oxidative degradation of 3-indole acetic acid. This study aimed to investigate different technological factors for a possible effect on the oxygen radical absorption capacity (ORAC) and ATA development in white wine. Oxygenation during fermentation did not result in a significant effect on the development of ORAC or ATA development. Instead, the addition of ascorbic acid after vinification led to increased ORAC and decreased AAP formation. The first evidence of a tendency toward a correlation between ORAC and potential ATA development was found, with r = 0.365. This study showed the potential of the ORAC assay for an early assessment of the possible formation of ATA during wine storage.

Strategies to Enhance l-Isoleucine Synthesis by Modifying the Threonine Metabolism Pathway in Escherichia coli.

l-threonine as an important precursor substance of l-isoleucine and improving its accumulation in Escherichia coli became an important idea to construct a chassis strain with high l-isoleucine production. Meanwhile, the effect of l-threonine metabolic pathway disruption in E. coli for the improved production of l-isoleucine remains unrevealed. In the present study, a mutant strain of E. coli was engineered by inactivating specific metabolic pathways (e.g., Δtdh, ΔltaE, and ΔyiaY) that were associated with l-threonine metabolism but unrelated to l-isoleucine synthesis. This was done with the aim to reduce the breakdown of l-threonine and, thereby, increase the production of l-isoleucine. The results obtained demonstrated a 72.3% increment in l-isoleucine production from 4.34 to 7.48 g·L-1 in the mutant strain compared with the original strain, with an unexpected 10.3% increment in bacterial growth as measured at OD600. Transcriptome analysis was also conducted on both the mutant strain NXU102 and the original strain NXU101 in the present study to gain a comprehensive understanding of their physiological attributes. The findings revealed a notable disparity in 1294 genes between the two strains, with 658 genes exhibiting up-regulation and 636 genes displaying down-regulation. The activity of tricarboxylic acid (TCA) cycle-related genes was found to decrease, but oxidative phosphorylation-related genes were highly up-regulated, which explained the increased activity of the mutant strain. For instance, l-lysine catabolism-related genes were found to be up-regulated, which reconfigured the carbon flow into the TCA cycle. The augmentation of acetic acid degradation pathway-related genes assisted in the reduction in acetic acid accumulation that could retard cell growth. Notably, substantial up-regulation of the majority of genes within the aspartate pathway could potentially account for the increased production of l-isoleucine in the present study. In this paper, a chassis strain with an l-isoleucine yield of 7.48 g·L-1 was successfully constructed by cutting off the threonine metabolic pathway. Meanwhile, transcriptomic analysis revealed that the cutting off of the threonine metabolic pathway induced perturbation of genes related to the pathways associated with the synthesis of l-isoleucine, such as the tricarboxylic acid cycle, glycolysis, and aspartic acid pathway.

Long-term in-situ starvation and reactivation of co-digestion with food waste and corn straw in a continuous AnDMBR: Performance, sludge characteristics, and microorganism community

To explore the effects of in-situ starvation and reactivation in a continuous anaerobic dynamic membrane reactor (AnDMBR), the anaerobic co-digestion system of food waste and corn straw was firstly start-up and stability operated, and then stopped feeding substrate approximately 70 days. After long-term in-situ starvation, the continuous AnDMBR was reactivated using the same operation conditions and organic loading rate as the continuous AnDMBR used before in-situ starvation. Results shown that the anaerobic co-digestion of corn straw and food waste in the continuous AnDMBR can resume stable operation within 5 days, and the corresponding methane production of 1.38 ± 0.26 L/L/d was completely returned to the methane production before in-situ starvation (1.32 ± 0.10 L/L/d). Through analysis of the specific methanogenic activity and key enzyme activity of the digestate sludge, only the acetic acid degradation activity of methanogenic archaea can be partially recovered, however, the activities of lignocellulose enzyme (lignin peroxidase, laccase, and endoglucanase), hydrolase (α-glucosidase) and acidogenic enzyme (acetate kinas, butyrate kinase, and CoA-transferase) can be fully recovered. Analysis of microorganism community structure using metagenomic sequencing technology showed that starvation decreased the abundance of hydrolytic bacteria (Bacteroidetes and Firmicutes) and increased the abundance of small molecule-utilizing bacteria (Proteobacteria and Chloroflexi) due to lack of substrate during the long-term in-situ starvation stage. Furthermore, the microbial community structure and key functional microorganism still maintained and similar with that of starvation final stage even after long-term continuous reactivation. The reactor performance and sludge enzymes activity in the continuous AnDMBR co-digestion of food waste and corn straw can be well reactivated after long-term in-situ starvation, even though the microbial community structure can not be recovered to the initiating stage.

Alkyl halide formation from degradation of carboxylic acids in the presence of Fe(III) and halides under light irradiation

Advanced oxidation processes (AOPs) have been widely used in water and wastewater treatment and have shown excellent performance in remediating contaminated water. However, their oxidation byproducts, including halogenated organics, have recently attracted increasing attention. Alkyl halides are among the most important environmental pollutants in nature. Here, we report a Fenton-like reaction in which alkyl halides can form during the photodegradation of aliphatic carboxylic acids in the presence of Fe(III) and halides. Chloromethane, chloroethane, and 1-chloropropane were produced from the degradation of acetic acid, propionic acid and n-butyric acid, respectively. CH3Cl, CH2Cl2 and CHCl3 were all identified as the products of acetic acid with the yields of approximately 5.1%, 0.2% and 0.005%, respectively. It was demonstrated that hydroxyl radicals, halogen radicals and alkyl radicals were involved in the formation of alkyl halides. A possible mechanism of chloromethane formation was proposed based on the results. In real samples of saline water, the addition of carboxylic acid and Fe(III) significantly promoted the generation of CH3Cl under xenon lamp irradiation. The results indicated that the coexistence of Fe(III), halides and carboxylic acids enhanced the photochemical release of alkyl halides. The reactions described in this paper may contribute to knowledge on the mechanism of halogenated byproduct formation during AOPs.

Corrosion testing of solar cells: Wear-out degradation behavior

Corrosion is one of the main end-of-life degradation and failure modes in photovoltaic (PV) modules. However, it is a gradual process and can take many years to become a major risk factor because of the slow accumulation of water and acetic acid (from encapsulant ethylene vinyl acetate (EVA) degradation). In this work, an accelerated aging test for acetic acid corrosion was developed to probe wear-out and end-of-life behavior and facilitate screening of new cell, passivation, metallization, and interconnection technologies. In the tests, the top glass and EVA layers were removed from PV modules to expose the solar cells and interconnects. These “opened” modules were then placed in acid baths under varying conditions, including acid concentration, temperature, and electrical bias. Three cell technologies were tested, including Al-back surface field (BSF), passivated emitter and rear contact (PERC), and silicon heterojunction (SHJ). For all conditions, the presence of acid accelerated module power loss compared to control tests with water baths. Increased temperature accelerated the rate of degradation by several times. Application of electrical bias led to an initial drop in short circuit current, but these modules eventually outperformed the non-biased modules. In all tests, lead oxides were the primary degradation products detected, and found to accumulate mostly along the printed metallization, especially in proximity to the busbar. SHJ cells with a silver paste-based interconnection outperformed Al-BSF and PERC cells with a solder-based interconnection. The accelerated corrosion test methods can be optimized to match corrosion behavior observed in field modules with greater precision and shorter times than standard damp heat tests, and is especially useful to assess the long-term durability of the continuously increasing variety of corrosion sensitive PV materials and components. • Continued use of EVA poses risk for new cell technologies because of acid generation. • Accelerated corrosion test for solar cells is developed, improving upon damp heat. • Rate of power loss dependent on concentration, temperature, bias, and technology. • Cell interconnect solder joint most susceptible to corrosion by acid.

Iron-enriched coal and volcanic rock waste powder composite with enhanced microwave absorption capacity for the degradation of 2,4-D and atrazine pesticides in single and binary systems

A novel catalyst was synthesized employing coal and volcanic rock waste (VRW) residues enriched with iron nanoparticles, and its efficiency was investigated upon the degradation of (2,4-dichlorophenoxy)acetic acid (2,4-D) and atrazine (ATZ) pesticides. The composite was synthesized by a facile and effective chemical precipitation technique and extensively characterized by XRD, FTIR, XRF, ICP-OES, ICP-MS, and SEM-EDS. The effects of pH, catalyst dosage, and initial pollutant concentration were investigated in single and binary systems irradiated with microwave (MW) under atmospheric pressure. The optimal reaction conditions were obtained at pH 3 and 5 for 2,4-D and ATZ in single systems and pH 3 in binary systems, respectively, with 20 mg L−1 of initial pollutant concentration and 0.1 g L−1 of CVRWMag (coal, VRW, and nano-Fe3O4) catalyst. The kinetic data fitted better to the pseudo-first-order model (R2 > 0.965). In addition, the phytotoxicity was investigated with Lactuca sativa seeds, and the root elongation and the seed germination rate were enhanced as the MW irradiation time increased. The complete degradation of both compounds was reached within 30 min, with outstanding mineralization efficiency. The degradation efficiency was attributed to hydroxyl radical (OH) formation and electrostatic surface interaction, enhanced by hot spot formation. Therefore, the CVRWMag is a promising MW absorbing catalyst for the removal and degradation of pesticides without the need for H2O2 or any radical enhancing agent addition.

Bioaugmentation with methanogenic culture to improve methane production from chicken manure in batch anaerobic digestion

This study sought to investigate the effect of bioaugmentation on batch anaerobic digestion of chicken manure. The digestion performance with and without bioaugmentation and bioaugmented efficiency under different dosages were compared. The results demonstrated that bioaugmentation increased the methane yield and shortened the methane production time in batch reactors. Compared to the un-bioaugmented control, the methane yield of bioaugmented digesters was increased by 1.2-, 1.7-, 2.2-, 3.4-, and 3.6-fold at addition ratios of 0.07, 0.14, 0.21, 0.27, and 0.34 g VS bioaugmentation seed (BS)/g VSCM, respectively. However, higher bioaugmentation doses (0.34 g VSBS/g VSCM) did not exhibit significantly improved bioaugmentation efficiency, thus, the recommended dose is 0.27 g VSBS/g VSCM for biomethane conversion of CM. Moreover, whole genome pyrosequencing revealed that Methanoculleus and Methanobrevibacter predominated the non-bioaugmentation digesters, whereas Methanothrix, Methanobacterium, and Methanomassiliicoccus were the dominant methanogens in bioaugmentation digesters. The increased methane may be explained by an increase in the Methanothrix population, which accelerated acetic acid degradation. With bioaugmentation the mainly methanogenic pathways have become more diverse. From gene function perspective, bioaugmentation enhanced metabolic activities in digestor which function better in metabolism.

Improvement of environmental stress cracking performance, load‐carrying capacity, and UV light barrier property of polyethylene terephthalate packaging material

AbstractThis study deals with the improvement of light barrier properties and stress cracking strength of polyethylene terephthalate (PET) packaging materials by incorporating calcium metaborate (CaB2O4). CaB2O4 powders were synthesized by the sol–gel method. After the extrusion process produced PET/ CaB2O4 granules, the preform and bottle production was carried out by injection molding and blow molding. Compared to pure PET, UV transmittance is reduced (~88%), and it is more effective at lower wavelengths (<800 nm). Similarly, the presence of CaB2O4 improved the environmental stress cracking performance of PET packaging materials. While the burst strength increased in the range of 0.05%–0.2% CaB2O4 concentration, it decreased at higher concentrations. The load‐carrying capacity is approximately 109% higher than pure PET. Acetic acid (COOH) degradation increased with the incorporation of CaB2O4 particles, while isophthalic acid and diethylene glycol degradations did not change. The experimental data indicate that the photocatalytic degradation of the PET bottle is prevented significantly, and its mechanical performance is also improved with the incorporation of CaB2O4. Thanks to this novel product, the quality of food and beverages in PET packaging materials can be protected from the harmful effects of light, and the deformation of PET packaging materials can be prevented for various reasons.

Insights into ROS-dependent signalling underlying transcriptomic plant responses to the herbicide 2,4-D.

The synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D) functions as an agronomic weed control herbicide. High concentrations of 2,4-D induce plant growth defects, particularly leaf epinasty and stem curvature. Although the 2,4-Dtriggered reactive oxygen species (ROS) production, little is known about its signalling. In this study, by using a null mutant in peroxisomal acyl CoA oxidase 1 (acx1-2), we identified acyl-coenzyme A oxidase 1 (ACX1) as one of the main sources of ROS production and, in part, also causing the epinastic phenotype following 2,4-D application. Transcriptomic analyses of wild type (WT) plants after treatment with 2,4-D revealed a ROS-related peroxisomal footprint in early plant responses, while other organelles, such as mitochondria and chloroplasts, are involved in later responses. Interestingly, a group of 2,4-D-responsive ACX1-dependent transcripts previously associated with epinasty is related to auxin biosynthesis, metabolism, and signalling. We found that the auxin receptor auxin signalling F-box 3 (AFB3), a component of Skp, Cullin, F-box containing complex (SCF) (ASK-cullin-F-box) E3 ubiquitin ligase complexes, which mediates auxin/indole acetic acid (AUX/IAA) degradation by the 26S proteasome, acts downstream of ACX1 and is involved in the epinastic phenotype induced by 2,4-D. We also found that protein degradation associated with ubiquitin E3-RING and E3-SCF-FBOX in ACX1-dependent signalling in plant responses to 2,4-D is significantly regulated over longer treatment periods.

The influence of the association of barley plants with petroleum degrading bacteria on the hormone content, growth and photosynthesis of barley plants grown in the oil-contaminated soil

Maintenance of active plant growth is important for successful phytoremediation of soil contaminated with petroleum oil products. Strains of oil-degrading bacteria introduced into rhizosphere were found to reduce the extent of plant growth inhibition resulting from petroleum stress. The effect was due to combining the capacity for petroleum degradation with promotion of plant growth by bacterial phytohormones. The purpose of this work was to compare the relative importance of these mechanisms in supporting the growth of barley plants against the background of oil pollution of the soil. Plants were treated with bacterial suspensions of four strains capable of petroleum degradation and production of indole acetic acid (IAA, plant hormone of the auxin class). The strains were shown to differ in their ability to support plant growth under conditions of oil pollution. Introduction of bacteria into soil accelerated petroleum degradation. Nevertheless, oil degradation was not the only mechanism behind promotion of plant growth, since the strain with the lowest ability to degrade oil was characterized by a relatively high growth-stimulating activity. The highest ability to stimulate plant growth was detected in the case of strains, which were the most effective in increasing the concentration of IAA in plants and decreasing the stress-induced accumulation of abscisic acid (ABA).

Simultaneous Hydrogen Production and Acetic Acid Degradation by Heterogeneous Photocatalysis using a Metallurgical Waste as Catalyst

This study presents the generation of a renewable fuel using acetic acid as electron donor, copper slag (CS) as photocatalyst and UV–Vis irradiation. The CS was characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), and UV–Vis spectroscopy. Specific surface area (SBET) was determined on basis of N2 isotherms. A 23 factorial experimental design was performed to identify factors controlling the hydrogen evolution and mineralisation of acetic acid. The experimental factors were: slag dose (0.1, 0.55 and 1 g/L), acetic acid concentration (1, 5.5 and 10% vol) and reaction time (2, 5 and 8 h). Synthetic acetic acid solutions were used. An Analysis of Variance (ANOVA) was performed showing that slag dose, reaction time and an interaction between both factors were statistically significant (p-value < 0.05) for hydrogen generation. Two absorption edges (2.2 and 2.6 eV) were determined associated with the presence of fayalite and magnesioferrite identified by XRD. The best rate of the hydrogen production was 4.35 μmol/h g CS at 10% vol acetic acid, 0.1 g/L of CS and 2 h of reaction. This value is similar to values reported using similar catalysts. CS performance is due to the high iron content (60.09% wt. as Fe2O3) and traces of other semiconductors such as zinc, copper and manganese which may have some contribution to the photocatalytic activity.

The role of rice husk biochar addition in anaerobic digestion for sweet sorghum under high loading condition

Biochar is a carbon rich product made from the biomass pyrolysis process. Recently, biochar addition in anaerobic digestion processes has attracted attention for its possible functions to act as pH stabilizing agent, microbial carrier, and interspecies electron transfer. In this study, the effects of rice husk biochar addition in sorghum anaerobic digestion were investigated in batch tests. Under high F/M (food to microorganism) ratio conditions, obvious pH decreases and volatile fatty acids (VFA) accumulation was observed. Addition of 15 g/L biochar was found effective to increase the sorghum maximum methane production rate by 25 % and shorten the lag phase time by 44 %. Further biochar concentration increase showed little effects. Alkalinity increase brought by biochar addition contributed to the performance enhancement. Moreover, the promotive effects of biochar addition on degradation of acetic acid, propionic and butyric acid were not obvious under neutral pH conditions.

Stress-driven dynamic regulation of multiple tolerance genes improves robustness and productive capacity of Saccharomyces cerevisiae in industrial lignocellulose fermentation

Yeast productivity in lignocellulosic ethanol fermentation is clearly impeded by stress. Enhancing the robustness of xylose-fermenting yeast is important for improving lignocellulosic ethanol production. In this study, the glutathione biosynthesis pathway and acetic acid degradation pathway were strengthened to enhance yeast tolerance to stress due to elevated reactive oxygen species (ROS) and acetic acid. Dynamic feedback regulation of the anti-stress genetic circuits was achieved using stress-driven promoters discovered from the transcriptome to maintain low intracellular ROS, relieve the metabolic burden, and ultimately improve the robustness and ethanol production of yeast. The cell growth, xylose utilization and ethanol production of the engineered strain were enhanced under both stress and nonstress conditions. The engineered strain showed 49.5% and 17.5% higher ethanol productivity in laboratory media and industrial lignocellulosic media, respectively, at 36 °C compared with the parent strain. This study provides novel insights on the rational design and construction of feedback genetic circuits for dynamically improving yeast robustness.

Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability

Titanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel core-interlayer-shell TiO2 magnetic photocatalysts modified with metal nanoparticles (Pt, Cu), which exhibit both photocatalytic and magnetic properties, making it easily separable within the magnetic field. Accordingly, the core–shell structure of Fe3O4@SiO2/TiO2 was obtained in water/TX100/cyclohexane microemulsion. Platinum and copper were photodeposited on four TiO2 templates and characterized by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), specific surface area (BET) measurement and diffuse reflectance spectroscopy (DR-UV/Vis). Photoactivity was studied in the reaction of phenol, acetic acid, and methanol degradation under UV/Vis irradiation, using both polychromatic and monochromatic irradiation (action spectrum analysis). The core-interlayer-shell structure of Pt and Cu modified magnetic photocatalysts was confirmed using scanning transmission electron microscopy (STEM). Magnetic photocatalysts modified with platinum and copper revealed improved photoactivity both in oxidation and reduction photocatalytic reactions, as compared to unmodified Fe3O4@SiO2/TiO2 photocatalysts. Finally, the correlation between physicochemical properties and photocatalytic activities of Fe3O4@SiO2/TiO2-Pt/Cu photocatalysts was investigated. For the first time, the effect of metals’ loading on the efficiency of phenol degradation and mineralization (TOC removal), and quantum efficiency of reaction in the presence of magnetic photocatalysts were analyzed. It was found that phenol can be efficiently decomposed (ca. 100%) during 60 min of UV/Vis irradiation for the photocatalyst recovered within the magnetic field during three subsequent degradation cycles.

Field-Aged Glass/Backsheet and Glass/Glass PV Modules: Encapsulant Degradation Comparison

Ethylene vinyl acetate (EVA) is the predominant encapsulant in crystalline-silicon photovoltaic (PV) modules; however, its degradation is a subject of major concern, which causes significant power loss under field conditions. This article presents a comparison of EVA degradation in field-aged PV modules with glass/backsheet (G/B) and glass/glass (G/G) architectures. Modulelevel characterization included UV fluorescence imaging and I-V measurements. Material analytical techniques, including colorimetry, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Raman spectroscopy, were performed to correlate the module performance parameters with EVA material properties. An intense EVA discoloration in G/G modules was observed, which was corroborated by higher module Isc and Pmax degradation rates compared with its counterpart G/B modules. Higher power degradation was accompanied by a significant increase in EVA crosslinking, vinyl acetate content, yellowness index, and presence of functional groups containing unsaturated moieties that are linked to degradation products of photothermal reaction, and a higher decrease in the degree of crystallinity. The absence of a polymeric backsheet in hermetically sealed G/G modules, which restricts photobleaching and enhances the entrapment of volatile acetic acid and other degradation by-products, plays a major role in causing higher EVA degradation in G/G modules. This article concludes that EVA might have been a good choice of an encapsulant for the G/B modules over the decades, but it may prove to be an inappropriate choice for the G/G modules because of potential degassing, corrosion, and/or discoloration issues. Ionomers or polyester-based encapsulants like polyolefins could be best suited for G/G modules as it appears to be a current trend in the industry.

Correlation for Photocatalytic Degradation Kinetics of Carboxylic Acids using Electrochemically Synthesized Al2S3 Nanoparticles and Study of Antibacterial Activity

Aluminium sulfide (Al2S3) nanoparticles were successfully synthesized by electrochemical method. Further, the synthesized nanoparticles were used as a photocatalyst for degradation of trichloroacetic acid, chloroacetic acid, acetic acid and degradation kinetics was studied by volumetric method using NaOH under various experimental conditions. The Al2S3 nanoparticles were characterized by UV-visible spectroscopy, X-ray diffraction and SEM-EDAX. The study of UV-visible spectroscopy indicates that Al2S3 nanoparticles shows maximum intensity peak at 222 nm in the UV region and there is no absorption peak in the visible region, therefore the synthesized nanoparticles is active under UV light and band gap energy was found to be 3.07 eV, which was calculated using Tauc plot. The structure of Al2S3 was found to be tetragonal structure and average crystal size was found to be 25.76 nm, which was calculated using Debye-Scherrer′s formula. The SEM results showed that Al2S3 appears as nanoflakes with agglomerated. The presence of aluminium and sulfur was confirmed using EDAX spectra. The photocatalytic activity of the synthesized Al2S3 nanoparticles was examined by taking three carboxylic acids by volumetric method. Taft LFER was tested, the isokinetic temperature β was calculated for oxidation of carboxylic acids. The antibacterial activity was investigated for synthesized nanoparticles by using Bacillus subtilis MTCC 2763 and Escherichia coli MTCC 40 of different bacteria.

Synthesis of Nickel Oxide Nanoparticles by Electrochemical Method, Characterization and Photo degradation of Acetic Acid and Study of Antibacterial Activity of Synthesized Nickel Oxide Nanoparticles

Synthesis of Nickel Oxide Nanoparticles by Electrochemical Method, Characterization and Photo degradation of Acetic Acid and Study of Antibacterial Activity of Synthesized Nickel Oxide Nanoparticles

Synthesis of Cadmium Oxide Nanoparticles by Electrochemical Method: Its Photodegradative Effects on Carboxylic Acids and Antibacterial Behaviours

Cadmium oxide (CdO) nanomaterial has been synthesized by electrochemical method which is simple and inexpensive method. The synthesized cadmium oxide nanomaterial was used as a catalyst for the photocatalytic degradation of acetic acid, formic acid and oxalic acids under varies experimental conditions by volumetric method. The synthesized nanomaterials were characterized by various techniques such as UV-Visible spectroscopy, SEM-EDAX, FT-IR spectrum and X-ray diffraction studies. The UV-VIS spectroscopy study revealed that the band gap energy of cadmium oxide nanomaterials to be 2. 85 eV Tauc plot. The structure of cadmium oxide was found to be cubic structure and crystal size was found to be 32 nm which was confirmed from XRD data. SEM reports showed that the cadmium oxide nanomaterials have regular spherical shape and uniform size. The presence of cadmium and oxygen in the nanomaterial is confirmed from the EDAX spectrum. FT-IR spectra reveal the presence of characteristic band corresponds to Cd-O mode. The photocatalytic activity of the synthesized cadmium oxide nanomaterial was examined by the kinetics of photodegradation of carboxylic acids by volumetric method by using NaOH solution. Taft LFER was tested the isokinetic temperature β was calculated for oxidation of carboxylic acids. The antibacterial activity of cadmium oxide nanomaterial was investigated.<div><br></div>

Microwave-enhanced, stereospecific ring-closure of medium-ring cyanamide ethers to yohimbine

A highly efficient acid-promoted, stereospecific, transannular ring-closure of medium-ring ether compounds to the indole alkaloid yohimbine is described. Microwave-enhanced acetic acid degradation of cyanamide compounds involves loss of (R)- or (S)-ethers, followed by a stereospecific, nucleophilic ring-closure from the cyanamide to afford yohimbine in up to 74% yield in as little as one minute. This nucleophilic reactivity of the amino moiety of the cyanamide highlights an alternative reactivity profile from its traditional electrophilic properties. Additionally, this reaction pathway highlights a rare case of an SN1 pathway that proceeds with complete stereospecificity.