scholarly journals Two-Stage Dry Anaerobic Digestion of Beach Cast Seaweed and Its Codigestion with Cow Manure

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Valentine Nkongndem Nkemka ◽  
Jorge Arenales-Rivera ◽  
Marika Murto
Keyword(s):  
Methane Yield ◽  
Cow Manure ◽  
Two Stage ◽  
Limit Values ◽  
Second Stage ◽  
Anaerobic Codigestion ◽  
Stage System ◽  
Dry Anaerobic Digestion ◽  
Beach Cast

Two-stage, dry anaerobic codigestion of seaweed and solid cow manure was studied on a laboratory scale. A methane yield of 0.14 L/g VSadded was obtained when digesting solid cow manure in a leach bed process and a methane yield of 0.16 L/g VSadded and 0.11 L/g VSadded was obtained from seaweed and seaweed/solid manure in a two-stage anaerobic process, respectively. The results showed that it was beneficial to operate the second stage methane reactor for the digestion of seaweed, which produced 83% of the methane, while the remainder was produced in the first leach bed reactor. Also, the two-stage system was more stable for the codigestion for seaweed and manure when compared to their separate digestion. In addition, the initial ammonia inhibition observed for manure digestion and the acidification of the leach bed reactor in seaweed digestion were both avoided when the materials were codigested. The seaweed had a higher Cd content of 0.2 mg Cd/kg TS than the manure, 0.04 mg Cd/kg TS, and presents a risk of surpassing limit values set for fertiliser quality of seaweed digestate. Evaluation of the heavy metal content of seaweed or a mixture of seaweed and manure digestate is recommended before farmland application.

A novel two-stage method of plant seedlings classification based on deep learning

2021 ◽  
pp. 1-11
Author(s):  
Tianhong Dai ◽  
Shijie Cong ◽  
Jianping Huang ◽  
Yanwen Zhang ◽  
Xinwang Huang ◽  
...  
Keyword(s):  
Deep Learning ◽  
Learning Technology ◽  
Two Stage ◽  
Second Stage ◽  
Stage Classification ◽  
Different Types ◽  
Two Stages ◽  
Plant Seedlings

In agricultural production, weed removal is an important part of crop cultivation, but inevitably, other plants compete with crops for nutrients. Only by identifying and removing weeds can the quality of the harvest be guaranteed. Therefore, the distinction between weeds and crops is particularly important. Recently, deep learning technology has also been applied to the field of botany, and achieved good results. Convolutional neural networks are widely used in deep learning because of their excellent classification effects. The purpose of this article is to find a new method of plant seedling classification. This method includes two stages: image segmentation and image classification. The first stage is to use the improved U-Net to segment the dataset, and the second stage is to use six classification networks to classify the seedlings of the segmented dataset. The dataset used for the experiment contained 12 different types of plants, namely, 3 crops and 9 weeds. The model was evaluated by the multi-class statistical analysis of accuracy, recall, precision, and F1-score. The results show that the two-stage classification method combining the improved U-Net segmentation network and the classification network was more conducive to the classification of plant seedlings, and the classification accuracy reaches 97.7%.

scholarly journals Research on Efficiency of Animation Enterprises Based on Two-Stage DEA Network System Model of Sharing Input Resources

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Shuo Zhang ◽  
Xuemei Yang ◽  
Jian Zhang ◽  
Mengjie Liao ◽  
Lin Qi
Keyword(s):  
Production Quality ◽  
System Model ◽  
Network System ◽  
Research Model ◽  
Two Stage ◽  
Second Stage ◽  
Production Quantity ◽  
Overall Efficiency ◽  
Stage Efficiency

This research constructs a two-stage DEA network system model of shared input resources to evaluate the efficiency of animation companies: the first-stage efficiency to reflect the production quantity and the second-stage efficiency to reflect the production quality of animation products, where the quality of animation products is judged based on the market recognition of the animation products. The overall efficiency in the research model is used to describe the development of animation enterprises. According to the result, it is concluded that the overall efficiency of the surveyed animation companies and the efficiency of each sub-stage have shown an upward trend, which is in line with the growth of the company's development.

Treatment of septage using single and two stage activated sludge batch reactors systems

1995 ◽  
Vol 32 (9-10) ◽  
pp. 95-104 ◽  
Author(s):  
A. D. Andreadakis ◽  
G. Kondili ◽  
D. Mamais ◽  
A. Noussi
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Substantial Reduction ◽  
Subsequent Treatment ◽  
Batch Reactors ◽  
Two Stage ◽  
Second Stage ◽  
Nitrogen Concentrations ◽  
Stage System

The cyclic or sequencing batch activated sludge process was applied for the treatment of septage originating from cesspools serving non-sewered areas. Single and two stage systems were investigated in bench scale units. The single stage aerated system was capable in removing practically all the biodegradable COD and producing a well stabilised excess sludge with excellent settling and thickening characteristics. With respect to nitrogen the average removal rate was to the order of 70%, but the performance was unstable due to periodic strong inhibition of the nitrification process. Subsequent treatment in a second stage aerated unit improved nitrification but did not result in higher nitrogen removal rates due to the increased concentrations of oxidised nitrogen. An anoxic second stage post denitrification unit resulted in an overall nitrogen removal of 88%, through a substantial reduction of nitrates. Further improvement of the system, with nitrogen removal of about 95% and average effluent nitrogen concentrations lower than 10 mg.1−1, can be achieved by adoption of a two stage system consisting of a first aerated stage unit, followed by a second stage unit with alternating aerated and anoxic cycles and addition of external carbon during the anoxic cycle.

DIFFUSION ACTIVITY OF CARBON DURING POLYMORPHIC TRANSFORMATION OF STEEL AND TWO-STAGE LOW-TEMPERATURE CEMENTATION

2020 ◽  
pp. 3-10
Author(s):  
B. V. Fokin ◽  
A. A. Zhukov ◽  
A. P. Navoev ◽  
Yu. A. Kustov ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Polymorphic Transformation ◽  
Interatomic Interaction ◽  
Carbon Diffusion ◽  
Two Stage ◽  
Two Phase ◽  
Second Stage ◽  
Required Quality

It was studied diffusive mobility of carbon’s atoms in the process of decarbonation steel У8 and cementation steel Ст3 in the temperature’s interval of polymorphic transformation. It was set that low temperature cementation (LTC) is possible only after a preliminary austenitization steel. In the state of polymorphic transformation due to the weakening of interatomic interaction, the formation of a two-phase structure of complexes, there is a decrease in the activation energy of carbon diffusion and a corresponding increase in the diffusion coefficient, which indicates the possibility of conducting LTC. The diffusion ability of carbon in LTC in a two-phase state was estimated using the value of the effective activation energy of diffusion taking into account the relative content of austenite and ferrite according to the «lever» rule. As a result of the studies performed, the following two-stage LTC method is proposed: the first stage – austenization (carburization) of the surface layer at a temperature of 920 °С for 20 minutes; the second stage – cementation in the temperature range 700…740 °С for 2 hours. Subsequent hardening and low-temperature tempering provide the required quality of the cemented layer by analogy with the traditional cementation process.

scholarly journals Experience in conducting aftercare for children with consequences of neuroinfections on the basis of the Science Research Institute of Сhildren Infections

2018 ◽  
Vol 20 (2) ◽  
pp. 33-35
Author(s):  
I G Samoylova
Keyword(s):  
Nervous System ◽  
Infectious Diseases ◽  
Average Length ◽  
Science Research ◽  
Medical Rehabilitation ◽  
Two Stage ◽  
Second Stage ◽  
Clinical Center ◽  
Degree Of Disability ◽  
Stage System

The experience of medical rehabilitation for children who have undergone neuroinfections and other disorders of the central and peripheral nervous systems on the basis of the Children’s Scientific and Clinical Center of Infectious Diseases is presented. The importance of this problem is determined by the high degree of disability of children with lesions of the nervous system. Based on this center, a two-stage system of medical rehabilitation of children was developed and organized, which transferred the neuroinfections. The first stage is carried out directly in the profile department intended for the treatment of neuroinfections. In this department, children with diseases of the nervous system prevail, infectious and parasitic diseases accounting for 70.2 and 17.6%, respectively. The second stage of medical rehabilitation is conducted in the profile 55-bed rehabilitation department of day and night stay. The department is equipped with robotic medical diagnostic devices. In this department, not only those children who have undergone neuroinfections can be treated, but also with a number of complications arising from other diseases. A two-stage system of medical rehabilitation of children, created on the basis of the Children’s Scientific and Clinical Center for Infectious Diseases, is an exemplary model of providing medical rehabilitation for children. Nevertheless, there was a significant excess of the load on this department for such indicators as: the average length of stay of the patient on the bed, and also the average annual employment of the bed both at the first stage of medical rehabilitation and at the second stage. The data obtained during the study indicate the need to develop and expand the network of these institutions.

Efficiency Improvement in Entrained Flow Gasification

2011 ◽  
Author(s):  
Ankit Bhatnagar ◽  
S. Pushpavanam
Keyword(s):  
Oxygen Consumption ◽  
Single Stage ◽  
Stage Model ◽  
Two Stage ◽  
Entrained Flow ◽  
Second Stage ◽  
Cold Gas Efficiency ◽  
Stage System ◽  
Gas Efficiency ◽  
Cold Gas

In this work a one dimensional steady state model is developed for a single stage and two-stage bottom fed entrained flow coal gasifier for. The single stage model was first analysed for two different oxidants (i) oxygen and (ii) air to study their effects on gasification. Analysis proved oxygen to be the better oxidant. The model is then extended to a two stage gasifier. Here 30 (70) percent of the coal is fed in the first stage (second stage). The first (second) stage operates in oxidant rich (lean) environment. The performances of single stage and two-stage models are compared in terms of their cold gas efficiencies for the same coal feed rates. It is observed that a two-stage system has better cold gas efficiency (77%) than a single stage system (72%) with lower oxygen consumption. The two-stage model is used to optimise the O2/Coal ratio as the H2O/Coal ratio is varied in the 2nd stage. The optimum yields the highest cold gas efficiency with minimum possible oxygen consumption.

scholarly journals Inoculum Selection and Micro-Aeration for Biogas Production in Two-Stage Anaerobic Digestion of Palm Oil Mill Effluent (POME)

2019 ◽  
Vol 8 (1) ◽  
pp. 14-21
Author(s):  
Sri Ismiyati Damayanti ◽  
Dian Fitriani Astiti ◽  
Chandra Wahyu Purnomo ◽  
Sarto Sarto ◽  
Wiratni Budhijanto
Keyword(s):  
Anaerobic Digestion ◽  
Palm Oil ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Liquid Waste ◽  
Palm Oil Mill Effluent ◽  
Cow Manure ◽  
Two Stage ◽  
Second Stage ◽  
Palm Oil Mill

Two-stage anaerobic fluidized bed is an innovation in anaerobic digestion technology intended to handle liquid waste with high organic loading and complex substrate. The process is based on separation between acidogenic/acetogenic and methanogenic processes. The first stage is anaerobic process to convert substrate (represented as soluble chemical oxygen demand/sCOD) into volatile fatty acids (VFA). The second stage is methanogenic process to convert VFA into biogas. This study aimed to separate acidogenic/acetogenic and methanogenic processes by means of limited injection of air (micro-aeration) and inoculum selection. Micro-aeration was introduced in acidogenic/acetogenic stage because the relevant microbes were facultative so that the obligate anaerobic methanogens will be suppressed. On the other hand, the methanogenic reactor was kept completely anaerobic to ensure methanogenic dominance over acidogenic/acetogenic ones. Two sources of inoculums were used in this study, i.e. anaerobically digested biodiesel waste and anaerobically digested cow manure. Both inoculums were taken from active biogas reactor treating biodiesel waste and cow manure, respectively. Experiments were run in batch reactors treating palm oil mill effluent (POME) as the substrate for the acidogenic/acetogenic reactor. After the reaction in the first stage reached the minimum substrate concentration, the content of the reactor was used as the substrate for the methanogenic reactor as the second stage. Routine measurements were taken for sCOD and VFA concentrations, biogas production, and methane concentration in the biogas. Results confirmed that micro-aeration maintained good performance of acidogenic/acetogenic process, which was indicated by peaks in VFA accumulation, while suppressing methanogenic activities as no methane produced in this stage. Digested biodiesel waste was superior inoculum to be compared to digested cow manure with respect to sCOD removal. In the methanogenic stage, digested biodiesel waste also performed better as inoculum as it led to higher VFA conversion, higher biogas production rate, and higher methane content in the biogas. 

scholarly journals ALTERNATIVE FUELS FROM TECHNICAL OILS: INNOVATIVE METHODS AND TECHNOLOGIES OF OBTAINING AND USING

2020 ◽  
pp. 43-54
Author(s):  
V.I. Kirichenko ◽  
V.V. Kirichenko ◽  
V.P. Nezdorovin
Keyword(s):  
Temperature Regime ◽  
Alternative Fuels ◽  
Two Stage ◽  
Second Stage ◽  
Innovative Methods ◽  
Output Quality ◽  
Low Efficiency ◽  
A New Technique ◽  
The Given

The chemical aspects of increasing the efficiency of processing rape or soy-gm oils (oils in general) into biofuel by two methods are considered. These methods involve: traditional alcoholysis by methanol or ethanol and a new method — esterolysis which is based on reesterification reaction of ester oils mollecules by indusrially produced non-oil esters. The comparison of chemical-technological foundations of oils processing by traditional etanolysis and esterolysis by ethyl-acetate revealed that both technologies demonstrate unsatisfactory indicators of their efficiency, in particular temperature regime, selectiveness in relation to biofuels, output, quality and others, despite certain advantages of esterolysis. It is determined that overcoming the major reasons and consequences of low efficiency of these two methods is possible with the help of the innovative two-stage approach to the realization of technologies of ethanolysis and esterolysis. The chemical-technological principles of each stage of the two-stage processes have been developed, and the conditions of their procedure have been optimized. At the first stage, the alcoholysis of oils by glycerine, the so-called glycerolysis-2, is carried out, with the aim of changing triacyl-glycerine oils molecules into monoacyl-glycerine molecules. The second stage includes ethanolysis or esterolysis of monoacyl-glycerine molecules. The comparative analysis of the given material balances of technologies for one-stage and two-stage types of ethanolysis and esterolysis demonstrated a considerable increase of efficiency, mainly selectiveness, output and quality of biofuel. A new technique of optimizing the temperature regime of technologies for processing oils into biofuels is suggested. It is shown that the biofuel obtained with the help of two-stage ethanolysis is of better quality. It is confirmed that the most rational direction of using biofuel is the formation of composite diesel fuel. Ref. 12, Tab. 4.

Pilot-scale, two-stage, thermophilic batch anaerobic digestion of sugar beets

2013 ◽  
pp. 97-104
Author(s):  
Jaime Chavez ◽  
Samriddhi Buxy ◽  
Pratap Pullammanappallil
Keyword(s):  
Hydrogen Sulfide ◽  
Total Yield ◽  
Pilot Scale ◽  
Methane Yield ◽  
Nitrogen And Phosphorus ◽  
Two Stage ◽  
Sugar Beets ◽  
Volatile Solids ◽  
Working Volume ◽  
Stage System

Whole sugar beets without the tops and without size reduction were anaerobically digested in a batch, two-stage, thermophilic, pilot-scale digestion system. The two-stage system consisted of a solids digester (SD; 150 L working volume) into which the sugar beets were loaded and an anaerobic filter (AF; 600 L working volume). The methane yield from the system was 305 L at STP/kg volatile solids (VS) loaded and was obtained within 17 days. This is equivalent to 52 L of methane at STP/kg sugar beet as received from the stockpiles. 60% of the methane was formed in the AF and the rest in the SD. The methane yield from this pilot system was 80% of that obtained in laboratory scale trials. 90% of the total methane produced in the AF was collected within 10 days. A 10 day residence time would yield a total of 256 L at STP/kg VS or 84% of total yield from pilot scale system. The digester required addition of nitrogen and phosphorus nutrients. The biogas may not require hydrogen sulfide clean up before utilization.

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