Decomposition Of Organic Components Research Articles

Nanoscale chirality generated in zinc(II) orthophosphate clusters: evidence by vibrational circular dichroism.

Layered zinc(II) hydroxides (LZH) intercalating the deprotonated forms of R-(-) or S-(+)-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate (denoted as R- or S-BNDHPH, respectively) were prepared from Zn(NO3)2 at pH 5 and 60 °C by the mixing method. The obtained hybrid compounds (denoted as R- or S-BNDHP-/LZH, respectively) were heated from room temperature up to 800 °C under nitrogen atmosphere. According to the thermal gravimetric/differential thermal analysis measurements, hydroxyl groups were dehydrated at 270-400 °C, followed by the decomposition of organic components at 420-600 °C. X-ray diffraction patterns and scanning electron microscopy images indicated that the final products were a mixture of α-Zn3(PO4)2, ZnO crystals and non-crystalline zinc(II) orthophosphates. Vibrational circular dichroism (VCD) spectra were recorded before and after calcination. Before calcination, R- or S-BNDHP-/LZH exhibited VCD peaks assigned to intercalated R- or S-BNDHP-. The calcined products exhibited several VCD peaks in the range of 900-1200 cm-1, maintaining the mirror-image relationship between R-BNDHP-/LZH and S-BNDHP-/LZH used as starting materials. The observed peaks were assigned to the PO (symmetric), -POO-, and PO (asymmetric) stretching vibrations of the PO43- groups. According to theoretical simulations, the observed VCD activity can be rationalised in terms of vibrational coupling between two PO43- groups in a generated chiral zinc(II) orthophosphate cluster.

Amorphous (lysine)2PbI2 layer enhanced perovskite photovoltaics

Passivation materials play a crucial role in a wide range of high-efficiency, high-stability photovoltaic applications based on crystalline silicon and state-of-the-art perovskite materials. Currently, for perovskite photovoltaic, the mainstream passivation strategies routinely rely on crystalline materials. Herein, we have invented a new amorphous (lysine)2PbI2 layer-enhanced halide perovskite. By utilizing a solid phase reaction between PbI2 and lysine molecule, an amorphous (lysine)2PbI2 layer is formed at surface/grain boundaries in the perovskite films. The amorphous (lysine)2PbI2 with fewer dangling bonds can effectively neutralize surface/interface defects, achieving an impressive efficiency of 26.27% (certified 25.94%). Moreover, this amorphous layer not only reduces crystal lattice stress but also functions as a barrier against the decomposition of organic components, leading to suppressed de-structuring of perovskite and highly stable perovskite solar cells.

Investigating the Deformation Characteristics of Buried High-Density Polyethylene Pipes: Considering the Effect of Sequentially Applying Pressure and Elevating Temperature.

High-density polyethylene (HDPE) materials have many applications in the municipal solid waste (MSW) landfills. HDPE gravity drainage pipes are commonly utilized in MSW landfills because of the polymer’s resistance to harsh chemical conditions. When landfill wastes are freshly filled, the weight acting on the leachate collection pipe increases. The temperature of the leachate collection pipe increases as a result of the heat produced by the decomposition of organic components after waste filling. In this paper, the effects of sequentially applying pressure and elevating temperature on the deformation characteristics (such as deformations and strains) of HDPE pipes are investigated. Measurements of pipe deformations and circumferential strains from model experiments in which 110 mm HDPE pipes were backfilled with sand and subjected to 300 kPa of maximum vertical pressure at temperatures of 20, 60 and 80 °C showed the following results: (1) a classification of pipe behavior relative to the surrounding soil stiffness is advantageous for HDPE pipe design; (2) when temperature increases to 60 °C and 80 °C, the strain distribution around the pipe changes from V-shaped to U-shaped, and the pipe deformation profile changes from elliptical to rectangular; (3) when temperature increases from 20 °C to 60 °C, the vertical and horizontal pipe deflections increase by a factor of 1.08~1.19; (4) when temperature increases from 60 °C to 80 °C, the vertical and horizontal pipe deflections increase by a factor of 1.15~1.31; and (5) the existing analytical method that considers two extreme interfaces can capture the deformations measured in the model test well. In addition, preliminary recommendations for the design of leachate collection pipes are provided based on the analysis of differences in pipe profile versus temperature.

Fabrication and characterization of Y2Si2O7 fibers prepared by electrospinning

Ceramic fibers have played an important role in the thermal protection field of aerospace vehicles at high-temperature over the past decades. In this work, Y2Si2O7 precursor fibers were prepared by electrospinning and characterized. The spinning solution consisted of yttrium nitrate, tetraethyl orthosilicate, and polyvinyl alcohol. The microstructure and elements distribution of fibers was investigated by scanning electron microscopy. The decomposition of organic components and crystallization process of yttrium silicate were explored by thermogravimetry-differential scanning calorimetry. The phase composition of fibers was analyzed by X-ray diffraction. The results showed the fibers were composed of uniform tiny grains after calcined at 1000 °C and the phase of the fibers was α-Y2Si2O7. The size of grains increased with increasing calcination temperature and the intact fibrous structure was maintained. The average diameter of the precursor fibers was 1383 ± 345 nm and decreased to 786 ± 171 nm after calcined at 1300 ℃. Elements distribution was uniform in the fibers, confirming a good homogeneity of the fibers.

Fermentation Microbials Isolated from Marine: A Review

Marine fish is one of the foodstuffs that containsk many compounds that are good for the human body. Marine fish contain omega-3 essential fatty acids as Docosahexanoic Acids (DHA) which are few other animal protein ingredients. This fish is rich in nutrients and minerals that can help prevent and maintain the body's immune system so that the body is fit. The benefits obtained include maintaining the cardiovascular system, efficient brain function, preventing damage to the thyroid gland and improving eye health. Fermentation is one way to process fishery products by utilizing the decomposition process of compounds from complex protein ingredients. To ferment food, microorganisms are needed that play a role in the decomposition of organic components in the material. Microorganisms commonly used are lactic acid bacteria (LAB), acetic acid bacteria (BAA), bacilli or other bacteria, yeast, or filamentous fungi.

Effects of different returning method combined with decomposer on decomposition of organic components of straw and soil fertility

In view of the problems of low straw decomposition rates and reduced soil fertility in southern Liaoning, China, we investigated the effects of no-tillage mode (NT), deep loosening + deep rotary tillage mode (PT), rotary tillage mode (RT) and the addition of decomposing agent (the next is called a decomposer) (NT + S, PT + S, RT + S) on the decomposition proportion of straw, respectively, by using the nylon net bag method in combination with 365-day field plot experiments. The decomposition rules of cellulose, hemicellulose and lignin as well as the dynamics of soil organic carbon (SOC), soil microbial biomass carbon (MBC) and soil dissolved organic carbon (DOC) in straw returned to the field for 15, 35, 55, 75, 95, 145 and 365 days were analyzed. The results showed that in the short term, the decomposition of straw was better in both the rotray tillage and deep loosening + deep rotary modes than in the no-tillage mode, and the addition of decomposer significantly promoted the decomposition of straw and the release of carbon from straw, among them, the RT + S treatment had the highest straw decomposition proportion and carbon release proportion in all sampling periods. After a one year experimental cycle, the RT + S treatment showed the highest proportion of cellulose, hemicellulose and lignin decomposition with 35.49%, 84.23% and 85.50%, respectively, and soil SOC, MBC and DOC contents were also higher than the other treatments with an increase of 2.30 g kg−1, 14.22 mg kg−1 and 25.10 mg kg−1, respectively, compared to the pre-experimental soil. Our results show that in the short term, to accelerate the decomposition rate of returned straw and increase the content of various forms of carbon in soil, rotary tillage can be used to return the straw to the field, while also spraying straw decomposer on its surface. This experiment used a new straw decomposer rich in a variety of microorganisms, combined with the comparison of a variety of straw return modes, and in-depth study of straw decomposition effects of cellulose, hemicellulose and lignin. Thus, a scheme that can effectively improve the decomposition rate of straw and the content of various forms of organic carbon in soil within a short period of time was explored to provide theoretical support for the southern Liaoning.

Thermogravimetric and DSC Studies of Mixtures of Aluminum Powder with Low-Molecular Organic Compounds after Plastic Deformation under High Pressure

Powdered mixtures of aluminum with 20 wt % of organic components were subjected to plastic deformation under a pressure of 0.5–4.0 GPa on an anvil-type high-pressure apparatus and then investigated by thermogravimetry and DSC. In deformed mixtures in the T-range of 30–500°C, there was a decrease in mass associated with the decomposition of organic components, while there was an increase in mass associated with the oxidation of aluminum in the T-range of 500–800°C. The mass changes were accompanied by exothermic effects. The enthalpies of exoeffects in the high-temperature range were always higher than in the low-temperature range. The magnitudes of exothermic effects depended on the content of carbon and oxygen in organic molecules; in a series of organic acids, they depended on the pH of acids.

Estimation of methane generation from the landfill sites

Landfill Gas (LFG) recovery is a very important element of an integrated solid waste management. The use of the landfills for solid waste disposal will continue to be the predominant method worldwide. This includes the information on how LFG to energy technologies worldwide can be implemented to extract the energy locked up in the landfills. This contributes the consolidation of knowledge in the field of LFG.Provide an overview of the status and prospects of LFG including the technical aspects and benefits of LFG recovery. Estimate of the methane generation estimation once the empirical constants have been determined by using the LFG models.In the present study, various physico-chemical parameters of the MSW were analysed to characterize the waste dumped at Okhla landfill sites in Delhi, India, which shows that it contains a high fraction of degradable organic components. The decomposition of organic components produces methane, a significant contributor to global warming. Based on the waste composition, waste age and the total amount dumped, a first-order model (FOD) was applied to estimate the methane generation potential of the Okhla landfill site, which yields an estimate of 25.98×106 m 3 /year.

Production of High Purity Amorphous Silica from Rice Husk

Combustion of the rice husk produces rice husk ash, which consists of mainly silica. High purity silica can be produced by controlled combustion after acid treatment. In this study, leaching of rice husk with hydrochloric acid and sulfuric acid were carried out prior to combustion to obtain purer silica. It was found that pre-treatment of the rice husk with sulfuric acid had accelerated the hydrolysis and decomposition of organic components as revealed by thermogravimetry (TG) and Scanning Electron Microscopy (SEM) analyses. In a systematic study, the combustion of un-leached, hydrochloric acid-leached and sulfuric acid-leached rice husks were performed in a muffle furnace at 500, 600, 700, 800 and 900oC for 2h. Results demonstrated that all the samples produced amorphous silica (SiO2) and the average particle size were in the range of 0.50 to 0.70μm. The effect of combustion at different temperatures between 500oC and 900oC on the silica production is very small, particularly at temperature above 600oC. Thus, amorphous silica with purity above 99% as confirmed by X-Ray Fluorescence (XRF) analysis can be produced by hydrochloric and sulfuric acids leaching of the rice husk, followed by controlled combustion at 600oC for 2h. The BET surface area of the silica produced after leaching the rice husk with hydrochloric acid was higher (218 m2/g) than with sulfuric acid (209 m2/g). The silica obtained has potential application as filler in plastics and rubber compounding.

Effect of Interaction between Earthworm and Microbes on the Degradation Time of Agro-Waste

Impact of macro-organisms in biological processes had been considerably studied but some of the discrete interactions that exist between macro- and micro-organisms still remain complex and sometimes elusive. Agro-waste is a type of waste that remains highly inevitable in our society and its disposal is a subject of concern. Therefore, this study aimed to degrade sugarcane bagasse which is a significant agro-waste in Malaysia, while trying to understand the interaction between microbes and earthworm utilized in the bioprocess. Sugarcane bagasse was blended with spent tea in equal ratio before composting with the aid of Eudrilus eugeniae and introduced microbial consortia. Though varied, pH values across the amendments tended towards alkaline state, just as the available Phosphorus (P) and exchangeable Potassium (K) increased in the value. Total organic carbon (TOC) across the amendments showed reduction in value; 47% in TS (tea and sugarcane bagasse), whereas 25% in TS6M (Tea + sugarcane bagasse + 6 microbes) and 68% in TS3M (tea bagasse + 3 microbes). However, weight loss in Eudrilus eugeinae was found to be proportional to the reduced time of degradation. TS3M at 33% worm weight loss was recorded at 11 day degradation time, than TS6M (27%) and TS (16%) that showed 13 and 20 days degradation time respectively. Weight loss in earthworm is correlated with microbial interaction and can be a reflection of rate decomposition of organic components of agro-waste in a vermicomposting process.

Mathematical Simulation of the Behavior of Spent Organic Extracting Agent in the Near-Well Region in the Case of Deep Burial

A mathematical model of the physicochemical processes occurring in a reservoir bed with simultaneous disposal of organic and aqueous radioactive wastes in deep-lying porous geological formations is presented. The model includes a description of filtration, convective-dispersive mass transfer, sorption and desorption of radionuclides by the surrounding rock, radioactive decay, decomposition of organic components, and convective heat transfer and heat transmission. The numerical implementation of the method is used as a basis for developing computer software that makes it possible to perform predictive calculations of the change in the state of a reservoir bed of radioactive wastes. The results of the simulation of the dynamics of the thermal fields and the behavior of the components of the spent organic extracting agent and aqueous radioactive wastes in the reservoir bed in the deep-disposal test area are presented.

Healthy Substrates Need Physicals Too!

Many research studies have evaluated potential organic and mineral container substrate components for use in commercial potting substrates. Most studies report results of plant growth over a single production season and only a few include physical properties of the substrates tested. Furthermore, substrates containing predominantly organic components decompose during crop production cycles producing changes in air and water ratios. In the commercial nursery industry, crops frequently remain in containers for longer periods than one growing season (18 to 24 months). Changes in air and water retention characteristics over extended periods can have significant effect on the health and vigor of crops held in containers for 1 year or more. Decomposition of organic components can create an overabundance of small particles that hold excessive amounts of water, thus creating limited air porosity. Mineral aggregates such as perlite, pumice, coarse sand, and calcined clays do not decompose, or breakdown slowly, when used in potting substrates. Blending aggregates with organic components can decrease changes in physical properties over time by dilution of organic components and preserving large pore spaces, thus helping to maintain structural integrity. Research is needed to evaluate changes in container substrates from initial physical properties to changes in air and water characteristics after a production cycle.

Analysis of Pyrolysis Products during Thermal Decomposition of Organic Components in Ceramic Green Bodies

For improved quality and machinability of ceramic green bodies the use of organic additives is necessary. During the debinding process the polymers are thermally decomposed and partially emitted as ecotoxicologically relevant components. The aim of this study was to determine and to quantify these compounds during pyrolysis with the ultimate goal of reducing the emission of undesirable pyrolysis products. Four organic polymers frequently used in ceramics industry were investigated: polyacrylic acid (PAA), polyvinyl alcohol (PVA), polyethylene glycol (PEG) and latex. The decomposition experiments were carried out using a tube furnace. Cylindrical green bodies, mainly Al 2 O 3 but also SiC, containing a common amount of 5 mass % of organic additives were pressed and heated. To gather the different volatile decomposition products, a branched sampling system with different adsorbents was developed. After elution of these adsorbents separation and quantification of the pyrolysis products were performed using GC/MS and HPLC. The main pyrolysis products of the three aliphatic organic additives are low molecular mass aldehydes in particular the potentially carcinogenic form-, acet-, and crotonaldehyde in the range of mg/g. According to the used polymer, the concentration of aromatic compounds varies over a wide range from μg/g to mg/g. While the pyrolysis of PEG results in nearly undetectable concentrations of aromatics, mono-, di-, and trimers of ethylene glycol, 2-methyl-1,3-dioxolan and 1,4-dioxan are formed in concentrations in the range of mg/g. The formation of the potentially carcinogenic 1,4-dioxan could be of toxicological relevance.

The effect of oxygen addition on the determination of cadmium and lead in blood and foods by graphite furnace atomic absorption spectrometry

It is well known that in the analysis of low temperature vaporized metal elements such as cadmium and lead, a high ashing temperature causes a loss of the target atoms at the ashing stage, while low ashing temperature causes incomplete decomposition of organic components in the sample. In order to solve these problems, the effect of oxygen addition on determination of cadmium and lead in blood and foods was studied. Oxygen was introduced into the atmosphere in the graphite furnace at the beginning of ashing stage for 20 seconds at 0.5 l/min. Relation between ashing temperature and sensitivity was examined, and the oxygen addition minimized signal depression by the sample matrix. It can be concluded that the addition of oxygen at the ashing stage not only reduces the background absorption, but also suppress the volatilization of target atoms at the ashing stage by the formation of their oxides.

The applicability of DTA to the study of ceramic fibres

To determination of thermal properties of different ceramic fibres the DTA method has been applied. Characteristic temperatures of the glass fibres have been determined. As a result of the study of aluminosilicate fibres temperature of mullite crystallisation has been evaluated. Alumina spinel polycrystalline fibres were obtained from organic solutions and then they were heated to get ceramic structure. DTA and TG methods can be applied to the investigation of chemical processes during decomposition of organic component and forming of fibras ceramic structure.