Homogeneous Flow Performance of Steel-Fiber Reinforced Self-Consolidating Concrete for Repair Application: A Biphasic Approach

In this study, fiber-reinforced self-consolidating concrete (FR-SCC) was considered as a diphasic suspension of fiber and coarse aggregate (F-A ≥ 5 mm) skeleton in mortar suspension with solid particles finer than 5 mm. The coupled effect of the volumetric content of fibers, coarse aggregate particle-size distribution, and rheological properties of the mortar on the passing ability and dynamic stability of various FR-SCC mixtures was investigated. Nine high-strength and 10 conventional-strength FR-SCC mixtures for repair application were proportioned with water-to-binder ratios (W/B) of 0.35 and 0.42, respectively, and macro steel fibers of 0.1%–0.5% volumetric contents. The dosages of high-range water-reducer (HRWR) admixture were optimized to achieve a targeted slump flow of 680 ± 20 mm. The yield stress and plastic viscosity of the mortar mixtures varied between 4.6-17.7 Pa and 2.8–8.2 Pa s, respectively. Flow performance of the investigated mixtures were evaluated in terms of flowability (slump-flow test), passing ability (J-Ring and L-Box set-ups), and dynamic stability (T-Box test). According to the established correlations, the main influencing parameters on homogeneous performance of FR-SCC include W/B, paste volume, volumetric content-to-packing density of F-A (φ/φmax), HRWR dosage, fiber content, mortar rheology, and volume of excess mortar. The robustness analyses results revealed that homogeneous flow performance of FR-SCC is more sensitive due to variations of the φ/φmax and paste volume rather than mortar rheology, W/B, and HRWR dosage. The characteristics of the mixture constituents for FR-SCC mixtures with different strength levels were finally recommended to ensure acceptable homogeneous performance under restricted flow conditions of repair application

Homogenous Flow Performance of Steel Fiber-Reinforced Self-Consolidating Concrete for Repair Applications: Developing a New Empirical Set-Up

In this study, a new empirical Square-Box test was employed to evaluate the homogeneous flow performance of fiber-reinforced self-consolidating concrete (FR-SCC) under confined-flow conditions that are typical of repair applications. The Square-Box set-up consisted of a closed-circuit box, providing 2.4-m flow distance and a closed-surface cross section of 100-mm width and 200-mm height, equipped with 0 and 4 rows of reinforcing bar grids with 45-mm clear spacing. The flow performance was assessed in terms of dynamic stability and passing ability. The investigated mixtures were considered as diphasic suspensions of fiber-coarse aggregate (F-A \u3e 5 mm) in suspending mortars containing particles finer than 5 mm. According to the experimental results, the dynamic segregation and blocking indices of the investigated mixtures were found in good agreements with characteristics of F-A combination and rheology of mortar. The investigated mixtures exhibited significantly higher blocking indices through the Square-Box set-up compared to those obtained using the L-Box test. Furthermore, the characteristics of F-A and rheology of mortar showed opposite effects on dynamic segregation assessed using Square-Box and conventional T-Box set-ups. Under confined flow conditions, higher dynamic segregation led to more dissimilar compressive strength values at different flow distances through the proposed Square-Box set-up. A new filling ability classification was established based on the experimental dynamic stability and passing ability results of the proposed empirical test

Coupled Effect of Fiber and Granular Skeleton Characteristics on Packing Density of Fiber-Aggregate Mixtures

The addition of fiber to cementitious materials enhances mechanical performance but can reduce workability of the fiber-reinforced concrete (FRC) mixtures. This can be due to the negative effect of fibers on packing density (PD) of the fiber-coarse aggregate (F-A) combination. The performance of FRC, as a diphasic suspension, is dependent on the characteristics of both F-A (suspended-solid skeleton) and mortar (suspending liquid) phases. PD can reflect the voids within the F-A skeleton to be filled with mortar. An adequate optimization of the characteristics of the F-A skeleton can modify the performance of FRC in fresh and hardened states. The F-A skeleton can be characterized in terms of particle-size distribution, volumetric content, and morphology of the coarse aggregate, as well as size, rigidity, and content of fibers. In this study, a comprehensive investigation was undertaken to identify the coupled effect of the characteristics of fibers and coarse aggregate on the PD of F-A combination used without any cement paste/mortar. The solid components play a key role in the overall performance of the concrete produced. This study was carried out to optimize the F-A combination and enhance the workability design of FRC. Various types of steel, polypropylene, and polyolefin fibers having different sizes and rigidities were investigated. Moreover, four combinations of three different classes of coarse aggregate were used to proportion F-A mixtures. Test results showed that shorter length, smaller diameter, and more flexible fibers can lead to higher PD of F-A systems. Moreover, the coarser aggregate skeleton with larger interparticle voids led to more available length for fibers to be deformed, hence improving the PD of F-A mixtures. New empirical models were proposed to predict the packing density of F-A combinations given the characteristics of coarse aggregate and fibers, as well as the level of compaction. The established models were employed to propose a new proportioning approach for fiber-reinforced self-consolidating concrete mixtures to achieve the targeted workability

Novel Tri-Viscous Model to Simulate Pumping of Flowable Concrete through Characterization of Lubrication Layer and Plug Zones

In this study, computational fluid dynamics (CFD) was employed to simulate the pipe flow of 18 self-consolidating and four highly workable concrete mixtures in a 30-m long pumping circuit. Pressure loss (ΔP) in 100- and 125-mm diameter (DP) pipelines was measured under low (1.2–6.2 l/s) and high (8.1–16.4 l/s) flow rates (Q). The numerical simulation was successfully carried out using a two-fluid model and a new variable-viscosity single-fluid approach, namely double-Bingham and tri-viscous models, respectively. The radial variation of rheological properties of the concrete across the pipe section, representing the plug flow, sheared concrete, and lubrication layer (LL) zones was successfully simulated based on a total of 404 pipe flow experiments. The relative LL viscous constant (ηLL) values obtained using numerical simulations-to-those obtained experimentally using a tribometer ranged between 30% and 200%. Moreover, the coupled effect of the characteristics of different flow zones, DP, and Q on ΔP was evaluated

Association between vitamin D levels and insulin resistance in patients with type 2 diabetes mellitus

Background: Insulin resistance (IR) is a major contributor to type 2 diabetes mellitus (T2DM) and is associated with various metabolic disorders. Vitamin D deficiency (VDD) has been linked to an increased risk of T2DM, but the relationship between vitamin D status and IR in T2DM patients remains unclear. This study explores this association in a male population with T2DM in Baghdad, Iraq.Methods: A case-control study was conducted on 190 male participants: 40 healthy controls and 150 patients categorized into different groups; 40 diabetic patients, 55 with coronary artery disease (CAD) and T2DM (CAD+DM), and 55 with only CAD. Physicians diagnosed them, and they were evaluated by physical and full medical history. All the sample set parameters were measured in the fasting state for each group. The biochemical tests included body mass index (BMI), vitamin D levels, insulin levels, fasting tests glucose (FBG), and HbA1c were measured. Insulin resistance was calculated using the HOMA-IR model.Results: Vitamin D levels were significantly lower in all diabetic groups (DM, CAD+DM) compared to the control group (p<0.001). All diabetic patients had insulin resistance. BMI was significantly higher in the CAD and CAD+DM groups compared to controls (p<0.00001, p<0.004). FBG, HbA1c, insulin levels, and HOMA-IR were all significantly higher in diabetic patients compared to controls (p<0.001 for all). Furthermore, increased HbA1c, fasting insulin, and homeostatic model assessment for insulin resistance (HOMA-IR) were associated with CAD progression in T2DM patients (p < 0.001).Conclusion: This study suggests that vitamin D deficiency may contribute to insulin resistance in male T2DM patients in Baghdad, Iraq. Maintaining optimal vitamin D levels may be beneficial in diabetes management in this population. Incorporating vitamin D screening into routine check-ups for T2DM patients could aid in early detection and prevention of insulin resistance-associated complications.Keywords: Diabetes mellitus; Insulin resistance; Vitamin D; Coronary artery disease 

Improved Multi-Verse Optimizer In Text Document Clustering For Topic Extraction

This study aims to propose a suitable TE approach, which provides a better overview of the text documents. To achieve this aim: First, A new feature selection method for TDC, that is, binary multi-verse optimizer algorithm (BMVO) is proposed to eliminate irrelevantly, redundant features and obtain a new subset of more informative features. Second, three multi-verse optimizer algorithm (MVOs), namely, basic MVO, modified MVO, hybrid MVO is proposed to solve the TDC problem; these algorithms are incremental improvements of the preceding versions. Third, a novel ensemble method for an automatic TE from a collection of text document is proposed to extract the topics from the clustered document

Changing God’s Creation through Plastic Surgeries

أهداف البحث: يهدف هذا البحث إلى معرفة مدى اعتبار التغيير للحسن والجمال وصفًا يصلح للتعليل؛ ليُقاس عليه كل ما هو جديد في المسألة. منهج الدراسة: اتبع الباحثان المنهج الاستقرائي والتحليلي والنقدي المقارن؛ لإنجاز أهداف الدراسة والإجابة عن مشكلتها. النتائج: توصلنا إلى عدة نتائج من أهمها: أن التزين والتجمل يعد من العادات والمعاملات، وهو مما يلتفت فيه إلى المعاني والتعليل والقياس، وليس في وصف "تغيير خلق الله" نص يدل عليه صراحة أو دلالة، أو إجماع، كما لا يصلح عِلَّة يُبنى عليها حكم عمليات التجميل التحسينية، فلا بد من البحث عن علة أخرى تصلح لبناء الحكم عليها. أصالة البحث: امتاز هذا البحث بتناوله مسألة التعليل بوصف تغيير خلق الله من ناحية أصولية، واختبار هذا الوصف وعرضه على مسالك العلة؛ لمعرفة مدى صلوحه لأن يكون عِلَّة ابتداء، قبل البحث في ضابطه وتحديد معناه.Purpose: This study aims to examine the extent to which change for the good and beautiful could be considered a description fit for explanation to measure all that is novel in this issue. Methodology: The researcher relies on the comparative inductive, analytical and critical methodology to accomplish the objectives of the study and answer its problem. Findings: The study reaches several conclusions, the most important of which: that adornment and beautification are habits and social transactions, in which meanings, explanation and measurement are turned to. There is nothing that refers to that issue explicitly or implicitly in the explanation of "changing God's creation". Neither is there any consensus. This is not fit also to be a reason on which Fiqhi opinion of aesthetic cosmetic operations could be based. It is then necessary to search for another reason suitable for building the opinion on. Originality: This study is characterized by its handling of the issue of reasoning by using the description of “changing God's creation” from a fundamental perspective. The study also tests this description and looks in to it where the modes of reasoning is concerned to determine the extent to which it could be considered as a reason in the first place, before studying its controls and defining its meaning

Earlier stage for straggler detection and handling using combined CPU test and LATE methodology

Using MapReduce in Hadoop helps in lowering the execution time and power consumption for large scale data. However, there can be a delay in job processing in circumstances where tasks are assigned to bad or congested machines called "straggler tasks"; which increases the time, power consumptions and therefore increasing the costs and leading to a poor performance of computing systems. This research proposes a hybrid MapReduce framework referred to as the combinatory late-machine (CLM) framework. Implementation of this framework will facilitate early and timely detection and identification of stragglers thereby facilitating prompt appropriate and effective actions

Narancs- és sárgabaracklé egyes fizikai és kémiai tulajdonságainak változása a tárolás során

Der Gehalt an Vitamin C, an gesamten und reduzierenden Zuckern, an Säure (berechnet als Zitronensäure) und an gesamter wasserlöslicher Trockensubstanz von frischen und mit Schwefeldioxid behandelten Orangesäften (Valencia) und Aprikosensäften (EI-Amar) wurde bei ihrer Lagerung bei 25, 5 und — 18 °C studiert. Der Vitamin C-, Gesamtzucker, Gesamtsäure- und g esamte wasserlösliche Trockensubstanzgehalt war niedriger in din mit Schwefeldioxid behandelten Säften, während die Menge der reduzierenden Zucker höher als die in frischen Säften erhaltenen Werte. Die Behandlung mit Schwefeldioxid verbesserte die Farbe beider Fruchtsäfte, aber besonders doe des Aprikosensaftes. Der Gehalt an Vitamin C verminderte sich im allgemeinen während der Lagerung, die Geschwindigkeit der Abhanme war jedoch geringer bei niedrigeren Temperaturen. Die während der Lagerung bei verschiedenen Temperaturen im Vitamin C-Gehalt stattfindenden Verluste waren rascher im Aprikosensaft als im Orangesaft. Der Gesamtzuckergehalt des frischen Saftes vor der Lagerung war etwas grösser im Aprikosensaft als im Orangesaft. Die Menge des reduzierenden Zucker war aber im Orangesaft höher. Der Gesamtgehalt an Zuckern und der Gehalt an reduzierenden Zuckern verminderte sich im allgemeinen bei Lagerung bei 5 und 25 °C. Keine Verluste waren jedoch wahrnehmbar bei einer Lagerung bei — 18 °C 35 Tage lang. Ein umgekehrtes Verhältnis bestand zwischen dem Gehalt an reduzierenden Zuckern und dem Säuregehalt. Während der Lagerung war in dem gesamten wasserlöslichen Substanzgehalt der bei den angegebenen Temperaturen gelagerten Orange- und Aprikosensäfte keine nennenswerte Änderung wahrgenommen. Nach den sensorischen Proben waren die frischen und die mit Schwefeldioxid behandelten Orange- und Aprikosensäfte bei 25 °C höchstens 2 Tage lang, bei Lagerung bei 5 °C höchstens 9 Tage lang zum menschlichen Genuss geeignet. Die bei -1 8 °C gelagerten Säfte waren jedoch sogar nach einer 35tägigen Lagerung zum Genuss geeignet. Changes in the contents of vitamin C, total and reducing sugars, total acidity determined as citric acid, and total water-soluble solids were studied in fresh and SO?-treated orange (Valencia), and apricot (El-Amar) juices stored at 25 °C, 5 °C and — 18 °C. The contents of vitamin C, total sugar, acidity and total water-soluble contents were in juices treated with SO. lower and contents of reducing sugars higher than those in fresh juices. The colour of both juices, especially that of apricot juice improved after the preserving process. Generally, the vitamin C contents decreased during storage, but the decreasing rate was lower at lower temperatures. The losses in vitamin C contents during storage at different temperatures took place quicker in apricot juice than in orange juice. In the fresh juice before storage, the contents of total sugar were somewhat higher in apricot juice than in orange juice. Howewer, more reducing sugar was found in the orange juice. In general, storage at 5 °C and 25 °C resulted in a reduction of total and reducing sugars. Neverthless, no noticeable loss was observed when the juices were stored at — 18 °C for a period of 35 days. An inverse relationship was found between contents of reducing sugars and acid content. During the period of storage, there were no noticeable changes in the total water-soluble solids of orange and apricot juice stored at the applied temperatures. The results of sensory tests indicate that both the fresh and the preserved apricot and orange juices are suitable for human consumption for not more than two days when stored at 25 °C and for not more than nine days when stored at 5°C.The tested juices were suitable for human consumption even after a period of 35 days when stored at - 18 °C

Discrete-Element Modeling of Shear-Induced Particle Migration during Concrete Pipe Flow: Effect of Size Distribution and Concentration of Aggregate on Formation of Lubrication Layer

The Paper Seeks to Better Understand the Particulate Mechanics Giving Rise to the Lubrication Layer (LL) in Flows with Wide Particle-Size Distributions (PSD) Typical of Concrete Pumping Applications. the Study Uses a Soft-Sphere Discrete Element Method (DEM) to Simulate the Shear-Induced Particle Migration (SIPM) Mechanism of Formation of the LL. to Provide Realistic Understanding of SIPM and Rheological Heterogeneity of Concrete, Three Wide PSDs (Fine, Medium, and Coarse) and Three Different Concentrations (10 %–40 %) of Five Spherical-Particle Subclasses (1–17 Mm Diameter) Were Investigated. the Radial Evolution of Concentration and Particle Distribution Was Simulated over Time and the LL Formation Was Successfully Simulated. the Predicted LL Thicknesses Compared Well with Experimental Values. the Coupled Effect of PSD, Concentration, and Mean Diameter of Particles on Wall Effect, SIPM, and Rheological Heterogeneities Across the Pipe Was Evaluated. Higher Rheological Heterogeneity Across the Pipe Was Obtained for Higher Concentration and Coarser Particle Size Distributions