Estimating the compressive strength of fly ash added concrete using artificial neural networks

The aim of this study is to develop an artificial intelligence that predicts the compressive strength of fly ash substituted concretes using material mixing ratios. Within the scope of the study, 5 different fly ash mixed concrete samples were estimated. The strength values were estimated using artificial neural networks before the produced samples were subjected to the pressure test. In order to develop the artificial neural network, it is introduced as a dataset of 1030 different mixing ratios consisting of experimental results in the existing literature. In order to estimate the compressive strength, varying ratios of 8 different materials such as water, cement, fly ash entering the mixture are analyzed. As a result of the study, it has been observed that the predictions made using artificial neural networks are very close to the strength values obtained from the experiment

Mechanical and microstructural properties of mortars: Obsidian powder effect

Concrete has been the world's most produced and utilized building material for years due to its economic and easy accessibility. However, it attracts attention due to the CO2 emitted from cement, the raw material of concrete, during the production and consumption stages. Although there are different research studies to reduce this emission, one of the most logical solutions is to use pozzolanic materials with cement and reduce the need for cement. This paper investigated the general material characteristics of mortar samples generated by substituting obsidian powder with pozzolanic properties into cement at different ratios by weight. Mortar specimens with varying proportions of obsidian, such as 0%, 10%, 20%, and 30% by weight, were subjected to mechanical tests at 3, 7, 14, and 28 days. Material tests like X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize the material. As a result of the mechanical tests, 42.52 MPa compressive strength was obtained from the 28-day reference sample, while 44.331 MPa compressive strength was obtained from the mortar sample with 30% obsidian substitution. The outcomes of this paper noted that obsidian powder, which has pozzolan-ic properties, increased the mechanical strength of cementitious mortar specimens. This work indicates the suitability of using obsidian as pozzolan material with cement was determined

Predicting mechanical properties in geopolymer mortars, including novel precursor combinations, through XGBoost method

Concrete is the most widely used material in the building industry due to its affordability, durability, and strength. However, considering carbon emissions, it is believed that concrete will be replaced by geopolymers in the future. As numerous parameters significantly affect the strength of geopolymers, the performance of potential algorithms for strength prediction needs to be evaluated for different binders to select an appropriate algorithm. This study employs machine learning approaches to provide the best prediction method for the flexural strength and compressive strength of geopolymers. A new dataset containing 533 compressive strength and 533 flexural strength values of geopolymers with different binders such as waste glass (GW), obsidian (OB), and fly ash was created. The best prediction solution, with R2 = 0.981 for compressive strength and R2 = 0.898 for flexural strength, was obtained from the extreme gradient boosting (XGBoost) algorithm. Additionally, several other machine learning models were employed, including linear regression, k-nearest neighbors, deep neural network, and random forest, with corresponding determination coefficient (R2) values of 0.763, 0.804, 0.93, and 0.96, respectively. These models were trained and evaluated using a dataset encompassing features such as binder types, age, and heat, to forecast the mechanical properties of geopolymers. Among these models, XGBoost demonstrated the highest R2 value, indicating superior performance in predicting both compressive and flexural strengths. The findings of this study provide valuable insights into the selection of appropriate machine learning algorithms for predicting mechanical properties in geopolymers, thus contributing to advancements in sustainable construction materials

Heavy aggregate and different admixtures effect on pavings: pyrite, corundum and water-retaining polymer

Concrete pavings are widely used in the construction industry as flooring for decorative and structural purposes in the gardens, parks, and roads of America, and Europe. In the present study, the effects of pyrite, corundum, and water-retaining polymer additives on the surface wear resistance of concrete pavings were investigated. Concrete pavings were poured in 2 stages and all of the bottom layers of samples were the same, but upper layers of pavings were produced by adding pyrite in the ratio of 0.10, 0.20, 0.30, 0.40 according to the mass of the aggregate, 5 kg /m2 corundum-based surface hardener to the paving surface area, and a high amount of water-absorbing polymer at a ratio of 0.05 and 0.10 to the water content of the mixture. Vertical abrasion, splitting tensile strength, water absorption, freeze-thaw resistance, pendulum footed friction, and surface hardness measurements with Schmidt test hammer experiments were made to TS 2824 EN 1338 standard. Also, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses were carried out to characterize the produced materials. Results of the study indicate that the use of pyrite, corundum, and water-retaining polymers provided improvements in the surface wear resistance of concrete pavings

Effect of wrapping thickness and type on reinforced bridge piers: A numerical study

This research paper investigates the impact of wrapping thickness and type on reinforced bridge piers through a numerical study. The Incesu bridge, located in the Ardanu & ccedil; district of Artvin province, was selected as the case study, as it was completed with low concrete strength. Initially, the bridge was examined, revealing that the piers were inadequate against dynamic, dead, pedestrian, and covering loads. The study concentrated on employing carbon fiber reinforced polymer to reinforce the bridge piers. Various models were wrapped with carbon fiber reinforced polymer in full-length, half-length, and one -meter intervals. In the analysis, it is assumed that the wraps are linked to each other in both principal directions and not detached from one another. Along with the analyses conducted, stress and strain values are presented separately. It was observed that the wrapping effect obtained in smallsized elements in literature could not be obtained in large-sized elements. As the concrete quality improves, the influence of wrapping thickness diminishes. Moreover, the effects of full-length and half-length wrapping are very close to each other, suggesting that halflength wrapping of bridge piers is sufficient. The authors believe that the obtained analysis results will prove beneficial in achieving economic advantages in retrofitting projects within the construction sector

Common Methylenetetrahydrofolate Reductase Polymorphisms (A1298C & C677T) in Ectopic Trophoblasts and Methotrexate Treatment Failure in Tubal Pregnancies

Objectives: The success rate of methotrexate (MTX) therapy varies among tubal ectopic pregnancies. Commonmethylenetetrahydrofolate reductase (MTHFR) polymorphisms (C677T&A1298C) have been suggested to alter MTX effect. This study aimed to assess and compare MTX treatment failure rates with respect to MTHFR polymorphisms in trophoblasts of ectopic tubal pregnancies.Material and methods: A retrospective chart review of tubal ectopic pregnancies was conducted and 34 eligible cases were found. Paraffinized blocks of ectopic trophoblastic tissues were retrieved from the archives of pathology department.Common MTHFR polymorphisms were studied on microdissected trophoblastic tissues. Sixteen cases with history of failed MTX therapy (study group) and 18 control cases were compared for their pertinent clinical characteristics and common MTHFR polymorphisms (C677T&A1298) data.Results: In the study group, there were 8 (50%) C677T single nucleotide polymorphisms (SNP) and 9 (56.7%) A1298C SNP. Polymorphism rates were not found to be different between two groups for neither polymorphism (p > 0.05 for both). Number of compound heterozygotes was 3 (18.7%) in study group and 5 (27.7%) in controls (p = 0.693). In addition, MTHFR polymorphism presence seemed to have no effect on interval serum β-hCG concentration change in MTX-fail group (p=0.693).Conclusions: Our data implied that common MTHFR polymorphisms of ectopic trophoblastic tissue are not associated with MTX failure in patients with tubal pregnancies. Additionally, serum β-hCG concentration changes caused by MTX treatment and studied MTHFR polymorphisms are likely independent

Prevalencija triju virusa medonosne pčele u Turskoj

In this study, 10 worker bees from each of 28 different apiaries were collected (a total of 280 honey bees) from 6 provinces of the Black Sea region in Turkey. These samples were tested by Reverse-Transcriptase PCR (RT-PCR), for three honey bee viruses: acute bee paralysis virus (ABPV), chronic bee paralysis virus (CBPV) and black queen cell virus (BQCV). In addition, the samples were microscopically examined for Varroa destructor. In conclusion, CBPV, BQCV and Varroa destructor were identified in 25%, 21.42% and 53.57% of the bees respectively, but ABPV could not be detected in apiaries. This is the first report of CBPV, BQCV in Turkey.Prikupljeno je po 10 radilica s 28 različitih pčelinjaka u šest provincija na području oko Crnoga mora u Turskoj. Uzorci su bili pretraženi lančanom reakcijom polimerazom uz prethodnu reverznu transkripciju (RTPCR) na tri virusa medonosne pčele: virus akutne pčelinje paralize, virus kronične pčelinje paralize i virus crnih matičnjaka. Uzorci su povrh toga bili pretraženi na prisutnost parazita Varroa destructor. Virus kronične paralize bio je ustanovljen u 25%, virus crnih matičnjaka u 21,4% i Varroa destructor u 53,57% pčela dok virus akutne pčelinje paralize nije bio dokazan. Ovo je prvi dokaz prisutnosti virusa kronične pčelinje paralize i virusa crnih matičnjaka u Turskoj

Mechanical and radiation attenuation properties of conventional and heavy concrete with diverse aggregate and water/cement ratios

Ovim istraživanjem predstavljaju se rezultati sveobuhvatnog laboratorijskog rada kojemu je cilj ispitati mehanička svojstva i svojstva smanjenja zračenja teških betona u kojima se kao agregat koristio pirit, krom i magnetit te betona normalne težine koji su se proizveli s tri različita vodocementna omjera (v/c = 0,4/0,5/0,6). U laboratoriju su provedena ispitivanja tlačne čvrstoće, brzine prolaska ultrazvuka, eksperimentalni modul elastičnosti te koeficijenta prigušenja mase tih betona. Na temelju provedenih ispitivanja utvrđeno je da betoni normalne težine i teški betoni imaju slično ponašanje u smislu tlačne čvrstoće i modula elastičnosti. U slučaju teških betona (njihovi v/c omjeri povećani su uslijed konstantne količine vode te smanjene količine cementa), gustoća se povećava zbog povećanja količine agregata veće gustoće u odnosu na cement u sastavu betona. To je razlog zašto teški betoni koji su proizvedeni s većim v/c omjerom te koji su manje čvrstoće mogu apsorbirati više rendgenskih zraka. Koeficijenti prigušenja mase konvergiraju pri visokim energetskim razinama kod teških i normalnih betona različitih gustoća.This paper presents the results of comprehensive laboratory work conducted for investigating the mechanical and radiation attenuation characteristics of heavyweight concrete produced with pyrite, chromium, and magnetite aggregates and normal weight concretes produced with three different water/ cement (w/c) ratios. Various experiments were conducted to determine the compressive strengths, ultrasound transmission velocities, experimental elasticity modules, and mass attenuation coefficients of these concretes. Heavy and normal weight concretes exhibited similar behaviour in terms of compressive strength and elasticity modules. In heavyweight concretes, with increased w/c ratios (by keeping the amount of water constant and decreasing the amount of cement), the corresponding density increased due to the increase in the amount of high-density aggregates rather than cement in the composition of concrete. Thus, heavyweight concretes produced with a high w/c ratio and low strength can absorb more X-rays. Mass attenuation coefficients converge in heavy and normal weight concretes with different densities at high energy levels

Investigation and Expression Analysis of R2R3-MYBs and Anthocyanin Biosynthesis-Related Genes during Seed Color Development of Common Bean (Phaseolus vulgaris)

Anthocyanins are responsible for the coloration of common bean seeds, and their accumulation is positively correlated with the expression level of anthocyanin biosynthetic genes. The MBW (MYB-bHLH-WD40) complex is thought to regulate the expression of these genes, and MYB proteins, which are a key factor in activating anthocyanin pathway genes, have been identified in several plants. This study demonstrated gene structures, chromosomal placements, gene duplications of R2R3-MYBs, miRNAs associated with R2R3-MYBs, and the interaction of these genes with other flavonoid regulatory genes. qRT-PCR was used to investigate the role of specific R2R3-MYBs and flavonoid genes in common bean seed color development. As a result of a comprehensive analysis with the help of in silico tools, we identified 160 R2R3-MYB genes in the common bean genome. We divided these genes into 16 classes on the basis of their intron-exon and motif structures. Except for three, the rest of the common bean R2R3-MYB members were distributed to all chromosomes with different densities, primarily located on chromosomes 3 and 8. We identified a total of 44 duplicated gene pairs dispersed across 11 chromosomes and evolved under purifying selection (Ka/Ks  <  1), 19 of which were derived from a whole-genome duplication. Our research uncovered 25 putative repressor PvMYB proteins that contain the EAR motif. Additionally, fifty different cis-regulatory elements regulated by light, stress, and hormone were identified. Within the genome of the common bean, we discovered a total of 36 microRNAs that target a total of 72 R2R3-MYB transcripts. The effect of 16 R2R3-MYB genes and 16 phenylpropanoid pathway genes, selected on the basis of their interaction in the protein-protein interaction map, playing role in the regulation of seed coat color development was evaluated using qRT-PCR in 5 different tissues at different developmental stages. The results revealed that these specific genes have different expression levels during different developmental periods, with higher levels in the pod filling and early pod stages than in the rest of the developmental periods. Furthermore, it was shown that PvTT8 (bHLH), PvTT2 (PvMYB42), PvMYB113, PvTTG1, and PvWD68 genes have effects on the regulation of seed coat color. The findings of this study, which is the first to use whole-genome analysis to identify and characterize the R2R3-MYB genes in common bean, may serve as a reference for future functional research in the legume