scholarly journals Determination of Nitrogen and Sulphur Mineralization in Batch and Semi-Continuous Anaerobic Digestion Using an Artificial Fiber Bag Technique

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4205
Author(s):  
Jacob Rosholm Mortensen ◽  
Alastair James Ward ◽  
Martin Riis Weisbjerg ◽  
Sasha Daniel Hafner ◽  
Henrik Bjarne Møller
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Nutrient Content ◽  
Sulphur Mineralization ◽  
Different Types ◽  
Before And After ◽  
Thermophilic Conditions ◽  
Semi Solid

In the biogas industry, feedstock plans are used to estimate methane production and nutrient content in the digestate, however, these predictions do not consider the mineralized nitrogen fraction of the feedstock, which is useful when determining the quality of the digestate. In this study, the artificial fiber bag technique, which is commonly used to study feedstock degradation in ruminants, was implemented in anaerobic digestion to quantify mineralization of N and S. The artificial fiber bags were used to enclose substrates but with access to inoculum because of small pores in the bags, thereby enabling digestion. The content of the bags was analyzed before and after digestion to quantify residual mass as well as N and S concentration in the substrate. The method was validated through batch anaerobic digestion of a single substrate with and without bags, where the bags showed little influence on methane production and degradation. Semi-continuous anaerobic digestion experiments showed higher substrate degradation and higher N and S release at thermophilic conditions using four different types of feedstocks and proved useful for solid feedstocks but less so for semi-solid feedstock. For N, most of the mineralization occurred during the first 15 days over a trial of 30 days.

scholarly journals Quality of screen printing in knit fabric for different mesh count on semi solid design

2020 ◽  
Vol 6 (6) ◽  
Author(s):  
Rasheda Begum Dina ◽  
Md Zulhash Uddin ◽  
UmmulKhair Fatema
Keyword(s):  
Screen Printing ◽  
Visual Assessment ◽  
Color Difference ◽  
Mesh Screen ◽  
Microscope Images ◽  
Different Types ◽  
Digital Microscope ◽  
Semi Solid ◽  
Screen Mesh

In semi solid design, the parameters of the quality of the printed fabric were color fastness, level of print detail, color difference, print coverage, saw-tooth effect, line sharpness etc. Actually, printed fabric quality was evaluated by these parameters. Again, print coverage, saw-tooth effect, line sharpness, etc. were examined by estimating different distances, angles etc. in printed fabric and these factors were compared with image positives. Mesh opening effect on the quality of screen printed fabric was investigated after printing the semi solid design on knit fabric using different mesh count screens and different types of the link. To print semi solid design on knit fabric different types of ink as well as non-identical mesh count was used. Then mesh screen out come on the design and form of printed fabric in screen printing was examined. For the evaluation of semi solid design effect there remains two different methods.The first one is visual assessment and another way is microscope observation. Here, to determine the probability of the amount of ink flowing by the screen, mesh opening area of every screen was considered and it was done from respective digital microscope images.

The issue of "oil shrinkage" during the compounding of oils in the processes of production, collection, preparation and transportation of hydrocarbon raw materials

2021 ◽  
pp. 104-113
Author(s):  
O. P. Deryugina ◽  
E. A. Trapeznikov
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Colloidal System ◽  
Main Pipelines ◽  
Different Types ◽  
Preliminary Study ◽  
The Stability ◽  
Mixed Oil

The article discusses the issue of industrial compounding, which improves the quality of the raw materials supplied to the main pipelines. Compounding from "to compound" (English) - to mix. When mixing different types of oil obtained, "incompatibility" is possible, which is expressed in the precipitation of a solid sediment and violation of the stability of the colloidal system and due to the differing properties of oils. Attention to this problem is due to the tightening of requirements for the quality of raw materials that must comply with modern standards. The article discusses the causes of the problem of "incompatibility" of oil during compounding and effective ways of solving it, substantiates the need for a preliminary study of the properties of mixed oil in order to identify possible incompatibility of various types of oil. The standard tests for determination of incompatibility indices characterizing the ability of raw materials to mix are considered. The article substantiates the need to develop methods for diagnosing the incompatibility of oils as the most important task of modern chemical science, the solution of which will improve the quality of the raw material obtained and solve many technological problems in the compounding process.

Influence of Leaning Materials on the Quality of Building Ceramics

2021 ◽  
Vol 903 ◽  
pp. 197-202
Author(s):  
Ruta Švinka ◽  
Visvaldis Švinka ◽  
Maris Rundans ◽  
Inta Timma ◽  
Laila Petersone
Keyword(s):  
Thermal Expansion ◽  
Glass Fibre ◽  
Material Properties ◽  
Quartz Sand ◽  
Main Method ◽  
Different Types ◽  
Ceramic Building ◽  
Formation Of Cracks

Clay of the deposit Liepa is used for the production of ceramic building and finishing bricks in the factory “Lode” in Latvia. In the present work different types of these clays were investigated and “quartz effect” was determined using quartz sand as a leaning material. The substitution of quartz sand with milled E-glass fibre from Valmiera Glass was investigated and the changes in the magnitude of the quartz inversion effect were analysed. Thermal expansion was the main method for the determination of possible formation of cracks during technological process. Powder of milled glass fibre in amount of 5–10 % affects such properties as water uptake, porosity and apparent density and provides the required material properties at a lower firing temperature.

scholarly journals Uncovering Types of Knowledge in Concept Maps

2019 ◽  
Vol 9 (2) ◽  
pp. 131 ◽  
Author(s):  
Ian M. Kinchin ◽  
Aet Möllits ◽  
Priit Reiska
Keyword(s):  
Curriculum Design ◽  
Concept Maps ◽  
Positive Impact ◽  
Educational Levels ◽  
Types Of Knowledge ◽  
Different Types ◽  
Legitimation Code Theory ◽  
Future Learning

Concept maps have been shown to have a positive impact on the quality of student learning in a variety of disciplinary contexts and educational levels from primary school to university by helping students to connect ideas and develop a productive knowledge structure to support future learning. However, the evaluation of concept maps has always been a contentious issue. Some authors focus on the quantitative assessment of maps, while others prefer a more descriptive determination of map quality. To our knowledge, no previous consideration of concept maps has evaluated the different types of knowledge (e.g., procedural and conceptual) embedded within a concept map, or the ways in which they may interact. In this paper we consider maps using the lens provided by the Legitimation Code Theory (LCT) to analyze concept maps in terms of semantic gravity and semantic density. Weaving between these qualitatively, different knowledges are considered necessary to achieve professional knowledge or expert understanding. Exemplar maps are used as illustrations of the way in which students may navigate their learning towards expertise and how this is manifested in their concept maps. Implications for curriculum design and teaching evaluation are included.

Effect of Welding Speed and Tool Pin Profile on Weld Quality of Friction Stir Welded Semi-Solid Aluminium Alloy 356

2013 ◽  
Vol 372 ◽  
pp. 471-477
Author(s):  
Prapas Muangjunburee ◽  
Sirikul Wisutmethangoon
Keyword(s):  
Welding Speed ◽  
Solid Metal ◽  
Rotating Speed ◽  
Friction Stir ◽  
Uniform Dispersion ◽  
Different Types ◽  
Fine Microstructure ◽  
Semi Solid ◽  
Tool Pin

The effect of welding speeds and tool pin profiles on microstructure and mechanical properties of semi-solid metal 356 joints produced by friction stir welding was investigated. In this work, the joints were made by using a fixed rotating speed of 1750 rpm with varying welding speed of 80, 120 and 160 mm/min. In addition, two different types of tool pins, cylindrical and square pin, were applied. The Scanning Electron Microscope (SEM) reveals fine microstructure and uniform dispersion of Si (Silicon) particles obtained from cylindrical pin than that of square pin. Transverse and longitudinal tensile strengths obtained from cylindrical pin are greater than square pin. Furthermore, the joint made from 1750 rpm, 160 mm/min with cylindrical pin shows highest strength.

Determination of Phenolic Compounds from Jimma Drinking Water Using 4-Aminoantipyrine

2020 ◽  
Vol 12 (5) ◽  
pp. 690-694
Author(s):  
Kassahun Dejene Belayneh ◽  
Khalid Siraj ◽  
Mengesha Tigist
Keyword(s):  
Drinking Water ◽  
Phenolic Compounds ◽  
Disease Transmission ◽  
Raw Water ◽  
Treated Water ◽  
Before And After ◽  
Sulfur Containing ◽  
Jimma Town

The quality of drinking water in Ethiopia is an influential environmental factor of health and water can use as a medium for disease transmission in countries on all continents; all are affected from the poorest to the richest. Moreover, in our globe millions of people are unprotected to unsafe concentration of chemical pollutants in the drinking water. Dichlorohenols are considered as key water pollutants that are destructive to creatures at stumpy concentrations and many of them have been clustered as detrimental pollutants because of their probable to damage human health even in low concentration. This research aimed to determine phenolic compounds from drinking water of Jimma town which is found south west of Ethiopia, by using 4-Aminoantipyridine (AAP). The sample of drinking water before and after treatment was collected for determination of pollutants which classified as raw water (RW), treated water (TW) and system distributed water (SDW). The sample of water was preserved by phosphoric acid and sulfuric acid under pH 4 and distillation was carried out in order to remove sulfur containing compounds by addition of CuSO4 solution. In the analysis of water using 4-Aminoantipyrine the treated water and the system distributed water have been contained 2.73 ppb and 3.64 ppb which had more phenolic compounds as compared to raw water of 1.18 ppb. Therefore, the existence of phenolic compound in both treated and system distributed water of Jimma town drinking water has more phenolic compounds as compared to the permissible level of both Ethiopian Standard, 2 ppb and EPA Standards, 1 ppb.

Anaerobic digestion of mixed microalgae cultivated in secondary effluent under mesophilic and thermophilic conditions

2015 ◽  
Vol 72 (8) ◽  
pp. 1398-1403 ◽  
Author(s):  
Glenda Cea-Barcia ◽  
Gloria Moreno ◽  
Germán Buitrón
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Incubation Temperature ◽  
Secondary Effluent ◽  
Microalgae Culture ◽  
Batch Tests ◽  
Volatile Solids ◽  
Thermophilic Conditions ◽  
Maximum Production Rate ◽  
Mesophilic Conditions

The anaerobic digestion of mixed indigenous microalgae, grown in a secondary effluent, was evaluated in batch tests at mesophilic (35°C) and thermophilic (50°C) conditions. Under mesophilic conditions, specific methane production varied from 178 to 207 mL CH4/g volatile solids (VS) and the maximum production rate varied from 8.8 to 26.1 mL CH4/(gVS day), depending on the type of microalgae culture. Lower methane parameters were observed in those cultures where Scenedesmus represents more than 95% of the microalge. The culture with the lowest digestion performances under mesophilic conditions was studied under thermophilic conditions. The increase in the incubation temperature significantly increased the specific methane production (390 mL CH4/g VS) and rate (26.0 mL CH4/(gVS day)). However, under thermophilic conditions a lag period of 30 days was observed.

scholarly journals METHODOLOGY FOR AUTOMATIC DETERMINATION OF CONTRAST OF LASER MARKING FOR DIFFERENT MATERIALS

2019 ◽  
Vol 3 ◽  
pp. 134
Author(s):  
Lyubomir Lazov ◽  
Edmunds Teirumnieks ◽  
Nikolay Angelov ◽  
Erika Teirumnieka
Keyword(s):  
Laser System ◽  
Digital Camera ◽  
Test Field ◽  
Automatic Determination ◽  
Technological Parameters ◽  
Test Analysis ◽  
Laser Marking ◽  
Different Types

A new methodology for determining and optimizing the contrast of the technological laser marking process has been developed. It can evaluate the quality of the markings regardless of the type of material and the type of laser system. To perform the test analysis, a specialized test field is programmed, which including the change of two of the main parameters influencing the marking process: the linear energy density (LED) and the linear density of the pulses (LDI). Marking of a test field consisting of squares of a certain size is done by means of a raster marking method with a constant step between the lines. The results are processed with a digital camera and specialized software. The maximum blackening is compared with the background of all fields and is juxtaposed with the effective energy needed to obtain a certain contrast. Several consecutive iterations are made, with each of the following experiments excluding the variants with least contrast. Thus, the study consistently brings the result to a minimum working area of the basic technological parameters, providing the user's desired contrast of the marking. The developed author's method of automatically determining the contrast of the laser marking reduces the time for preliminary experimental research and gives a reliable and subjectively absent way of qualitatively marking different types of industrial products.

scholarly journals Pemanfaatan Kunyit (Curcuma domestica Val) Untuk Memurnikan Minyak Jelantah

2018 ◽  
Vol 7 (1) ◽  
pp. 41
Author(s):  
Muhammad Silmi Hi Abubakar ◽  
Siti Nuryanti ◽  
Suherman Suherman
Keyword(s):  
Fatty Acids ◽  
Moisture Content ◽  
Free Fatty Acids ◽  
Quality Parameters ◽  
Test Results ◽  
Cooking Oil ◽  
Used Cooking Oil ◽  
Before And After

Study on the purification and quality test of used cooking oil with turmeric has been done. This study aims to determine the quality of cooking oil after purified turmeric. The quality parameters of oil studied were the moisture content, free fatty acids (FFA), and peroxide. The methods used for determination of these parameters were gravimetry for moisture content, acid-base titration for free fatty acids, and iodometric for peroxide. The test results for water from 0.6% to 0.4% free fatty acid from 1.2% to 0.2%, and peroxide levels before and after purification were successively from and 6 meq/g to 4 meq/g, respectively. Only free fatty acids of all three parameters met the requirement of SNI.

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