decomposition time
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Author(s):  
Nirvani S. Henrique ◽  
Katia L. Maltoni ◽  
Glaucia A. Faria

ABSTRACT Litterfall is an important source of soil nutrients, but its decomposition can be affected by the crop system used. The objective of this study was to evaluate litterfall decomposition and macronutrient stocks in coffee crop systems in shaded (SHCS) environments and those in full sun (FSCS). The experiment was conducted on a rural property in Cacoal, state of Rondônia, Brazil, in a 2 × 6 factorial scheme with two crop systems (SHCS and FSCS), and six litterfall decomposition evaluation times (0, 30, 60, 180, 300, and 360 days after the litterfall was returned to the soil (DAL)), with seven replicates. The constant of decomposition (k), half-life time (t1/2) at 360 DAL, and phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), and nitrogen (N) concentrations of the remaining litterfall were determined at each evaluation time. The litterfall in the SHCS had a greater weight loss and constant of decomposition and a lower half-life time at the last evaluation, and the weight loss increased as a function of decomposition time. The litterfall stocks of macronutrients N, P, K, Ca, and Mg showed a linear decrease throughout the decomposition time, and increases in sulfur stock were found at the last evaluation.


Author(s):  
Prismahardi Aji Riyantoko ◽  
Tresna Maulana Fahrudin ◽  
Kartika Maulida Hindrayani ◽  
Amri Muhaimin ◽  
Trimono

Time series is one of method to forecasting the data. The ACEA company has competition with opened the data in the Water Availability and uses the data to forecast. The dataset namely, Aquifers-Petrignano in Italy in water resources field has five parameters e.g. rainfall, temperature, depth to groundwater, drainage volume, and river hydrometry. In our research will be forecast the depth to groundwater data using univariate and multivariate approach of time series using Prophet Method. Prophet method is one of library which develop by Facebook team. We also use the other approach to making the data clean, or the data ready to forecast. We use handle missing data, transforming, differencing, decomposition time series, determine lag, stationary approach, and Augmented Dickey-Fuller (ADF). The all approach will be uses to make sure that the data not appearing the problem while we tried to forecast. In the other describe, we already get the results using univariate and multivariate Prophet method. The multivariate approach has presented the value of MAE 0.82 and RMSE 0.99, it’s better than while we forecast using univariate Prophet.


2021 ◽  
Vol 2 (2) ◽  
pp. 86-94
Author(s):  
Nio Maharani Putri ◽  
Anugrah Ricky Wijaya ◽  
Yudhi Utomo

Cu that is absorbed in marine sediments can accumulate in the food chain even in small concentrations. Cu analysis in these sediments can be used to analyze water pollution due to human activities. The purpose of this study was to determine the level of Cu in decomposed sediments with variation of solvent concentration, variation of decomposition time, and variation of solvent volume and then compare the result of Cu analysis decomposed using HNO3 solvent under effective condition with aqua regia solvent. The method of analysis used is decomposition technique of sediment sample by using reflux and then analyzed with AAS.. Cu yang terserap dalam sedimen laut dapat berakumulasi dalam rantai makanan meskipun dalam konsentrasi kecil. Analisis Cu dalam sedimen ini dapat digunakan untuk menganalisis pencemaran perairan akibat aktivitas manusia. Tujuan penelitian ini adalah menentukan kadar Cu dalam sedimen yang didekomposisi dengan variasi konsentrasi pelarut, variasi waktu dekomposisi, dan variasi volume pelarut dan membandingkan hasil analisis Cu yang didekomposisi menggunakan pelarut HNO3 pada kondisi efektif dengan pelarut akuaregia. Metode analisis yang digunakan yaitu teknik dekomposisi sampel sedimen dengan menggunakan refluks dan dianalisis dengan SSA.


Author(s):  
Ramdana Sari ◽  
Astuti Arif ◽  
Muhammad Restu ◽  
dan Retno Prayudyaningsih

Oyster mushroom (Pleurotus ostreatus) cultivation produces waste in the form of mushroom substrate that has passed the production period and contaminated substrate. Non-productive spent mushroom substrates (SMS) still contain nutrients that allow them to be composted. The main goal of this study is to determine the potential of SMS as compost. The composting was done by mixing each of the old substrate waste (P1) and contaminated (P2) with a solution of EM4 and sugar. Temperature measurement and material compost stirring were done every week. The test results after 8 weeks of composting showed that the physical characteristics of compost, including the color and texture, have complied with the standards of SNI 19-7030-2004, which was brown and smooth. P1 compost has an earthy odor while P2 compost still has a slight woody. The mass of P1 and P2 composts decreased by 32% and 32,4%, respectively. Micronutrients such as Fe, Zn, and Mo were varied and according to SNI 19-7030-2004, Minister of Agriculture Regulations No.28/Permentan/SR.130/5/2009 as well as Minister of Agriculture Regulations No.70/Permentan/SR.140/10/2011. Co did not comply with the standard. The water content, pH, and macronutrients such as N-total, P2O5, K2O dan C-organic in both types of compost were according to SNI 19-7030-2004, Minister of Agriculture Regulations No.28/Permentan/SR.130/5/2009 or Minister of Agriculture Regulations No.70/Permentan/SR.140/10/2011. The C/N ratio in compost was still high, compost P1 and P2 had 25,26% and 25,16%. To reduce the C/N ratio of compost, it is necessary to carry out several treatments such as increasing the decomposition time or adding other organic materials during the composting process. The addition of organic materials such as manure or bran allows the microbial activators to be optimally in decomposing compost material to shorten the composting time.


2021 ◽  
Vol 16 (3) ◽  
pp. 019-023
Author(s):  
Stoyan Vergiev

The Bulgarian Black Sea coastal zone is relatively protected from sea floods. Only extreme meteorological events such as unusual storms can cause flooding of coastal areas. Crucial for the application of rapid methods for vulnerability assessment of coastal plant communities from flooding caused by unusual storms over the Bulgarian Black Sea Coast is to obtain experimental data for sea water flood resilience. This study aims to determine the plant species survival in simulated flooding experiments in order to identify sea water flood resilience of five plant species with conservation status: Centaurea arenaria M. Bieb. ex Willd., Crambe tataria Sebeok, Aurinia uechtritziana (Bornm.) Cullen & Dudley, Silene thymifolia Sm., and Stachys maritima Gouan. As a result of a simulated flooding experiment, Critical Decomposition Time (CDT) was obtained. The five species were within the most vulnerable group (CDT < 48 h). The CDT was significantly shorter than floods with a maximum duration for the Bulgarian Black Sea Coast. Only the values of the parameter beginning of decomposition of the leaves were accelerated by higher water temperatures. Other parameters were unrelated to different water temperatures. The investigated species have low survival rates and low degree of sea water flood resilience and their communities will not be able to recover after flooding with maximum duration within one vegetation season.


2021 ◽  
Vol 9 (E) ◽  
pp. 847-856
Author(s):  
Attapol Arunwuttipong ◽  
Parinton Jangtawee ◽  
Viwat Vchirawongkwin ◽  
Wiyong Kangwansupamonkon ◽  
Kavin Asavanant ◽  
...  

BACKGROUND: Public transportation has been linked to an increase in the risk of coronavirus disease 2019 transmission. The effective decontamination system using aerosolized hydrogen peroxide can mitigate the transmission risk from using public transportation. AIM: The aim of this study was to develop and validate an effective decontamination system for public transport. METHODS: The experimental research was performed in 13 inter-city public buses. The aerosol generator with ultrasonic atomizer was used in the experiment. The validation process for disinfection was conducted using both a chemical indicator (CI) and spore discs biological indicator (inoculated with 106 Geobacillus stearothermophilus enclosed in glassine envelopes). The CIs and biological indicators were marked by number and placed in nine locations on each bus. The decontamination cycle was developed by analyzed of various aerosolized and decomposition period. Both concentrations of hydrogen peroxide, 5% and 7%, were used for comparison. RESULTS: In an aerosolized period, both concentrations of hydrogen peroxide at 30 min were effective for sporicidal 6-log reductions. The decontamination cycle totaled 100 min, based on a 70 min average decomposition time. CONCLUSIONS: The automated hydrogen peroxide aerosolized system is a highly effective and safe method of decontaminating public buses.


2021 ◽  
Author(s):  
Gabriela Iuliana Paraschiv (Ganea) ◽  
◽  
Stefania-Rodica Hubel (Angel) ◽  
Elena Condrea ◽  
◽  
...  

This paper aims to present a study linked with the evaluation of the life cycle of both biodegradable and compostable packaging focusing on the impact these have upon the environment, regardless of the life-cycle stage, actually looking at it as a whole. In this article, the evaluation process will focus on the final stage of the product's life - decommissioning and reintegration into the environment. At present, in order for products to be approved by consumers, who are increasingly selective about health and environmental protection, they need to send an appropriate message. The message for consumers can take different forms, being informed about: rational use of resources in the production process, economical and sustainable packaging, attestation of the quality of the product in question, the fact that they are sustainable (compared to similar products in trade). The explosive development of design technologies and software allows the identification of design solutions that lead to the optimization of the project in a new, clean, environmentally friendly formula. Eco-design must ensure technical and aesthetic accuracy, while identifying the optimal shape depending on the chosen material. Consumers are particularly concerned about its persistence in the environment, due to the decomposition time of 100 to 400 years (Zins Beauchesne et al., 2008), its non-renewable fossil resources and the amount of waste allocated to it. The presence of dispersed plastics in nature associated with their persistence in the environment causes major impacts on terrestrial and marine ecosystems (Allsopp et al., 2006). In this context, the objectives of this article are risk assessment, environmental performance assessment, environmental impact assessment and identification of possible changes in each phase of the life cycle of both biodegradable as well as compostable packaging, which in turn may be the originator source of environmental benefits.


2021 ◽  
Vol 13 (S) ◽  
pp. 159-167
Author(s):  
Artur A. PSYANCHIN ◽  
Elena M. ZAKHAROVA ◽  
Aigiz G. KHUSNULLIN ◽  
Vadim P. ZAKHAROV

The relevance of the study is conditioned by the fact that increased consumption of synthetic polymers leads to an increase in environmental pollution due to the long decomposition time of plastic waste. As a result, it is necessary to develop polymer composites based on a biodegradable polymer matrix, and to improve the performance properties of finished plastic products, it is necessary to purposefully select cheap and affordable inorganic fillers. Thus, the purpose of this study is to investigate the regularities in the generation of a spatially structured polymer matrix under UV irradiation of polylactide-based composites filled with aluminosilicate microspheres (ASM). The leading approach to the given problem is to melt polymer composites of various compositions and to determine the physical, mechanical, and thermophysical characteristics of the prototypes, including the supermolecular structure of the polymer matrix under the influence of ultraviolet irradiation. The study suggests that the filling of polylactide with ASM particles leads to an increase in the elastic modulus, a decrease in the strength at static rupture and resistance to dynamic destructive effects, as well as heat resistance. Small aluminosilicate microspheres, when added to polylactide, perform the function of nucleation and, even with a small content, increase the crystallinity degree by 3.7 percentage points. In the range of ASM content from 1 pph to 10 pph, the absolute value of the crystallinity degree practically does not depend on the filler concentration in the polymer composite. UV (ultraviolet) irradiation in the presence of air oxygen initiates the thermooxidative destruction of polylactide and leads to the establishment of a spatially structured polymer phase using the electrostatic intermolecular interaction of additionally formed oxygen-containing functional groups in macrochains, as well as partial intermolecular crosslinking during recombination of macroradicals. The establishment of spatial structures in the polymer matrix under UV irradiation determines an increase in the resistance of experimental samples to thermal effects. It is manifested in an increase in the bending temperature under load by 7-10 percentage points, a decrease in the crystallinity degree by 1.2-2.6 percentage points, a decrease in the fluidity of the meltage and also an increase in the glass transition and melting temperature. The materials of the study are of practical value for the development of biodegradable composites based on polylactide filled with inorganic components.


Author(s):  
Hypolith Koffi Kouadio ◽  
Alain Jacques Acka. Kotaix ◽  
Zoumana Konaté ◽  
Emmanuel Koffi Kassin ◽  
Stanislas Koffi Kouakou ◽  
...  

A study on soil mineral fertilization was carried out over three years in three cocoa farms in the Nawa region of south-western Côte d'Ivoire. The aim of this study was to evaluate the effects of mineral fertilizers on the decomposition time of cocoa leaf litter. The experimental design was Fisher block with four treatments (T0, T1, T2, T3) repeated three times. The treatments were for T0, the control without fertilizer, for T1, NPK fertilizer 0-23-19, for T2, NPK fertilizer 0-15-15 + 17 CaO + 5 MgO + 1 B2O3 + 0.5 Zn and for T3, NPK fertilizer 4-10-10 + 19 CaO + 4 MgO + 0.8 B2O3 + 0.3 Zn. In each treatment, 3 plots of 1 m2 were delimited with a 1 cm2 mesh wire grid. The rate of decomposition of the cocoa leaf litter was made by measuring twice a year the weight loss of the ground litter contained in the plots. Comparison of the average decomposition rates between treatments showed that the fertilized soils had the best rates during the first 6 and 12 months of the trial. In Soubré, the T2 treatment (24.6±0.6%) in the 6th month and the T1 (72.6±6.6), T2 (82.4±1.6) and T3 (78.8±4.0%) treatments in the 12th month had the best decomposition rates. At Divo, treatment T1 (38.8±0.5%) in month 6 and treatments T1 (57.8±1.7%), T2 (67.9±10%) and T3 (66.9±7.7%) in month 12 were the best. At Méagui, decay rates did not differ between treatments throughout the trial. The application of mineral fertilizers resulting from soil diagnosis reduced the decomposition time of the cocoa leaf litter.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5947-5963
Author(s):  
Ruidong Wang ◽  
Xia Yang ◽  
Yong Gao ◽  
Xiaohong Dang ◽  
Yumei Liang ◽  
...  

Salix psammophila has been extensively used as a sand barrier material for various desertification control applications. Elucidating the long-term decomposition characteristics and nutrient cycling process of this sand barrier in desert environments is of great importance. In this study, which was conducted for 1 to 9 years, changes in the mass loss percentage and the residual percentage in the decomposition process were explored of S. psammophila sand barriers in arid Northwestern China. In addition, the S. psammophila analysis nutrient elements release rule and its influence on soil properties were evaluated. The results showed that the decomposition process of S. psammophila sand barriers exhibited a “slow-fast” trend. After decomposition time for 9 years, mass decreased remarkably, and the residual percentage was 33.6%. Further, the nutrient release characteristics differed. C, P, and K were in the release state, whereas N was in the enrichment state. The decomposition percentage of the sand barriers was significantly correlated with N, P, K, C/N, C/P, and N/P (p < 0.05). The soil nutrient contents of C, P, and K contents increased 3.43, 2.23, and 2.08 g/kg compared to the initial values, respectively. The soil nutrient contents of N contents decreased 0.19 g/kg.


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