Development of the Strength of the Fluidized Bed Combustion Fly Ash Based Geopolymer in Time

ThispaperpresentsastudyintothemechanicalbehaviourofFluidizedBedCombustion (FBC)fly ash-based geopolymer.FBCflyashisaby-product of a burning of a solid fuel (hard coal in case of this study) in a furnace at a low temperature. FBC fly ash is a type of a waste which is more difficult to recycle than pulverized fly ash.UsingFBCflyashin geopolymers offers one possible way to recycle it. The main goals of the investigation were to determine the influence of curing temperature and curing conditions on the strength of FBC fly ash-based geopolymer; to determine the changes of strength over time and the changes of the temperature inside the geopolymer during the curing process. Tests have shown that the strength of the geopolymer generally increases in line with the increase of a curing temperature. The compressive strength stabilizes after 5 days of curing and yet continues to gain extra strength over the longer term. Theflexuralbehaviourisnotmonotonicandthereforehardtopredict.The temperature inside the geopolymer rises rapidly until reaching around 27.5°C and then decreases steadily. Keywords: geopolymer, Fluidized Bed Combustion Fly ash, temperature, strengt

Simultaneous Reconstruction of Duplication Episodes and Gene-Species Mappings

We present a novel problem, called MetaEC, which aims to infer gene-species assignments in a collection of gene trees with missing labels by minimizing the size of duplication episode clustering (EC). This problem is particularly relevant in metagenomics, where incomplete data often poses a challenge in the accurate reconstruction of gene histories. To solve MetaEC, we propose a polynomial time dynamic programming (DP) formulation that verifies the existence of a set of duplication episodes from a predefined set of episode candidates. We then demonstrate how to use DP to design an algorithm that solves MetaEC. Although the algorithm is exponential in the worst case, we introduce a heuristic modification of the algorithm that provides a solution with the knowledge that it is exact. To evaluate our method, we perform two computational experiments on simulated and empirical data containing whole genome duplication events, showing that our algorithm is able to accurately infer the corresponding events

Defining the optimal mixture composition of geopolymers based on the coal mine waste and the shale.

Nowadays, industry plays one of the main roles in daily life. Extractive industry is one of the oldest industries, present in almost each country. Unfortunately, besides the benefits connected with development of the extractive industry, there are also disadvantages such as enlarging amounts of stored industrial wastes. One of the ideas how to manage with unnecessary wastes is geopolymer, relatively new material which parameters are similar to the parameters of the concrete. The paper shows the following attempts to define optimal mixture composition of geopolymer based on the wastes from the coal mine and geopolymer based on the shale from the post-mining spoil tip. Coal mine waste, shale, powdered glass waste, metakaolin and sand were used as the raw materials. Sodium hydroxide and sodium silicate were used as activators. Mixtures consisting of mentioned components used in different ratios were prepared and poured into small moulds. The compressive strength of samples was tested after 3, 5 and 7 days. From the best mixture, the bigger samples of dimensions 4x4x4cm were prepared and tested after 7 and 14 days. The paper presents characteristics of used wastes, preparation and curing processes, test procedure and finally, compressive strengths and densities of tested geopolymers

Dysregulation of microRNAs in triple-negative breast cancer

Objectives: Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited treatment options and poor prognosis. TNBC is usually diagnosed at a relatively young age and is characterized by high risk of developing metastases. Some epigenetic regulation of gene expression is associated with TNBC. Expression of microRNAs (miRNAs) can serve as a potential tool for identifying critical biomarkers in TNBC. The aim of our study is to examine expression of selected miRNAs in TNBC and to assess the relationship between miRNA expression and clinicopathological factors. Material and methods: Expression levels of 19 selected miRNAs were compared between cancerous and normal breast tissues by use of qPCR method. We have evaluated the relationship between the expression level of miRNAs and clinicopathological factors such as: age, tumor size and lymph node status. Results: We found that in TNBC tissues, when compared with normal breast tissues, the expression of miR-190a, miR- 136-5p and miR-126-5p was significantly reduced (p = 0.0041, p = 0.0007, p = 0.0007, respectively) whereas expression of miR-135b-5p and miR-182-5p was significantly increased (p = 0.0194, p = 0.0041, respectively). We found a linear trend for tumor size and expression of miR-126-5p (p = 0.0296) and miR-135b-5p (p = 0.0241). Conclusions: Our study confirms that miRNA expression profile is dysregulated in TNBC patients compared to healthy controls. MiR-190a, miR-136-5p, miR-126-5p, miR-135b-5p and miR-182-5p may be associated with development and progression of TNB

Elastic modulus and stress-strain curve analysis of a tungsten mine waste alkali-activated concrete

In the paper the compressive strength, the elastic modulus and the stress-strain curve of an alkaliactivated concrete were studied. A tungsten mine waste mud (TMWM), aggregate (also from the tungsten mine), glass waste and metakaolin were used as raw materials. Sodium silicate and sodium hydroxide were used as activators. First, TMWM chemical composition was determined by scanning electron microscopyenergy dispersive spectroscopy (SEM-EDS). The maximum particle size was 18mm. Two cubes with side dimension of 15cm were prepared from the mixture. Samples were cured at 60°C for 24 hours. A concrete mixer, vibration table and an oven were used in the process. After the curing process, cubes were cut into seven prisms and one cube with the dimensions 15x7.4x7.4cm and 7.4cm respectively. After 28 days, the laboratory tests were performed. During the compressive strength tests, the displacements were also recorded which allowed drawing the stress-strain curve of the samples. The compressive strength ranged from 17.27 to 28.84MPa. The elastic modulus was calculated by four different standards: ASTM, LNEC and European standard. The elastic modulus ranged from 2.48 to 7.49GPa what showed that the material is more elastic than ordinary Portland cement concrete

Numerical simulation of mechanical properties tests of tungsten mud waste geopolymer

Geopolymers are believed to become in the future an environmental friendly alternative for the concrete. The low CO2 emission during the production process and the possibility of ecological management of the industrial wastes are mentioned as main advantages of geopolymers. The main drawback, causing problems with application of geopolymers as a building material is the lack of the theoretical material model. Indicated problem is being solved now by the group of scientists from the Silesian University of Technology. The series of laboratory tests are carried out within the European research project REMINE. The paper introduces the numerical analyses of tungsten mud waste geopolymer samples which have been performed in the Atena software on the basis of the laboratory tests. Numerical models of bended and compressed samples of different shapes are presented in the paper. The results obtained in Atena software were compared with results obtained in Abaqus and Mafem3D software

Unifying duplication episode clustering and gene-species mapping inference

Abstract We present a novel problem, called MetaEC, which aims to infer gene-species assignments in a collection of partially leaf-labeled gene trees labels by minimizing the size of duplication episode clustering (EC). This problem is particularly relevant in metagenomics, where incomplete data often poses a challenge in the accurate reconstruction of gene histories. To solve MetaEC, we propose a polynomial time dynamic programming (DP) formulation that verifies the existence of a set of duplication episodes from a predefined set of episode candidates. In addition, we design a method to infer distributions of gene-species mappings. We then demonstrate how to use DP to design an algorithm that solves MetaEC. Although the algorithm is exponential in the worst case, we introduce a heuristic modification of the algorithm that provides a solution with the knowledge that it is exact. To evaluate our method, we perform two computational experiments on simulated and empirical data containing whole genome duplication events, showing that our algorithm is able to accurately infer the corresponding events

Absolute Quantification of Selected microRNAs Expression in Endometrial Cancer by Digital PCR

MicroRNAs (miRNA) are involved in the process of carcinogenesis, including the development of endometrial cancer (EC). This study aimed to investigate the association between the expression of three miRNAs (miR-21-5p, miR-205-5p, and miR-222-3p) in endometrial cancer tissues. In addition, the stability of expression of SNORD48 and U6, which were initially planned to be used as reference miRNAs for normalization, was investigated. Endometrial tissue was obtained from 111 patients with EC during hysterectomy and from 19 patients undergoing surgery for uterine fibroids or pelvic organ prolapse as a control group without neoplastic changes. Our study was based on calculations made with a digital PCR method (Qiagen, Hilden, Germany) to measure the absolute expression. In the endometrial cancer tissue, miR-205-5p was upregulated, while miR-222-3p and SNORD48 were downregulated compared to the control group. We detected statistically significant correlation of miR-205-5p, U6, and SNORD48 expression with different histological grades; the expression of miR-205-5p increases with the histopathological grade advancement (intraepithelial neoplasia- EIN = 1590, G1 = 3367.2, G2 = 8067 and G3 = 20,360), while U6 and SNORD expression decreases from EIN to G2 and increases again in the G3 grade (U6: EIN = 19,032, G1 = 16,482.4, G2 = 13,642.4, G3 = 133,008; SNORD48: EIN = 97,088, G1 = 59,520, G2 = 43,544, G3 = 227,200). Our study suggests that upregulation of miR-205-5p and downregulation of miR-222-3p and SNORD48 may influence development of endometrial cancer. Moreover, miR-205-5p, U6, and SNORD48 expression changes may be associated with progression of endometrial cancer. The results also indicate that SNORD48 and U6, commonly used as internal references, may influence endometrial cancer development and progression; therefore, they should not be used as references. However, it is important to note that further research is required to understand their role in endometrial cancer

Elastic modulus and stress-strain curve analysis of a tungsten mine waste alkali-activated concrete

In the paper the compressive strength, the elastic modulus and the stress-strain curve of an alkaliactivated concrete were studied. A tungsten mine waste mud (TMWM), aggregate (also from the tungsten mine), glass waste and metakaolin were used as raw materials. Sodium silicate and sodium hydroxide were used as activators. First, TMWM chemical composition was determined by scanning electron microscopyenergy dispersive spectroscopy (SEM-EDS). The maximum particle size was 18mm. Two cubes with side dimension of 15cm were prepared from the mixture. Samples were cured at 60°C for 24 hours. A concrete mixer, vibration table and an oven were used in the process. After the curing process, cubes were cut into seven prisms and one cube with the dimensions 15x7.4x7.4cm and 7.4cm respectively. After 28 days, the laboratory tests were performed. During the compressive strength tests, the displacements were also recorded which allowed drawing the stress-strain curve of the samples. The compressive strength ranged from 17.27 to 28.84MPa. The elastic modulus was calculated by four different standards: ASTM, LNEC and European standard. The elastic modulus ranged from 2.48 to 7.49GPa what showed that the material is more elastic than ordinary Portland cement concrete