Prediction of self compacted rubberized concrete properties using Taguch methods

The effect and optimization of using self-compacting rubberized concrete was investigated by using Taguchi method. Design of experiment was performed via orthogonal array to accommodate four factors with four levels. These factors were the percentage of fine rubber, coarse rubber, fly ash and viscocrete in the concrete mix. The signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) were employed to study the performance characteristics of self-compacting rubberized concrete (SCRC). Rubberized concrete can be improved using the concrete proportioned as self-compacting concrete. The results indicate that there was a reduction in the strength with increasing rubber content but there was an increase in impact resistance. However, the replacement of 10% of coarse aggregate with coarse rubber gave more strength than that of zero rubber mix by 124% at 90 days. Replacement of 20% of both fine and coarse aggregates with fine and coarse rubber respectively, increased impact resistance by 453% compared to the corresponding SCRC control mix

An Application of Genetic Algorithms to Time-Cost-Quality Trade-off in Construction Industry

Time, cost and quality are used for measuring project success. So, they are considered the most important objectives in construction projects. Project managers should deliver their project on time with minimum cost and at a certain quality level. To get these conflicting objectives, project managers introduce many possible methods of execution (modes) for each activity in the project. This paper presents an optimization model that supports project managers and decision makers in performing this challenging task and leads to identification of the best solution. Developed model is based on Genetic Algorithms which have many advantages over traditional optimization techniques and considered suitable for more than one objective function. The developed Genetic Algorithms model considers target function, design variables affecting that target, and problem constraints. Through application to two projects, the model feasibility is examined. The results show that the proposed approach can help the practitioners in considering different modes for activities and easily find minimum cost for a certain project time meeting the quality requirements. The model can easily reach the best solution from huge number of solutions in reasonable running time. In addition, the results tell that the present method can be used in generating a group of optimal solutions. Key words: construction projects; time-cost-quality; trade-off; optimization; Genetic Algorithm

Technetium-labeled danofloxacin complex as a model for infection imaging

AbstractDanofloxacin, a fluoroquinolone derivative antibiotic, was synthesized, successfully labeled with technetium-99m and formulated for the development of a potential diagnostic imaging agent of the bacterial infection and inflammation with higher efficiency than that of the commercially available 99mTc-ciprofloxacin. Factors affecting the labeling yield were optimized. The radiolabeled antibiotic was subjected to preclinical assessments such as purity, stability, and pharmacokinetic investigations in animals. The biodistribution studies indicated that the uptake of 99mTc-danofloxacin was high in the infectious lesion (T/NT=7.2±0.1) at 2h post injection. The abscess to normal ratio indicated that the danofloxacin tracer can be used for infection diagnosis. The radiolabeled compound was cleared quickly from most of the body organs. The results displayed that 99mTc-danofloxacin could not differentiate between infection and sterile inflammation

Approximate solutions for solving nonlinear variable-order fractional Riccati differential equations

In this manuscript, we introduce a spectral technique for approximating the variable-order fractional Riccati equation (VO-FRDEs). Firstly, the solution and its space fractional derivatives is expanded as shifted Chebyshev polynomials series. Then we determine the expansion coefficients by reducing the VO-FRDEs and its conditions to a system of algebraic equations. We show the accuracy and applicability of our numerical approach through four numerical examples. &nbsp

Shifted Jacobi spectral collocation method with convergence analysis for solving integro-differential equations and system of integro-differential equations

This article addresses the solution of multi-dimensional integro-differential equations (IDEs) by means of the spectral collocation method and taking the advantage of the properties of shifted Jacobi polynomials. The applicability and accuracy of the present technique have been examined by the given numerical examples in this paper. By means of these numerical examples, we ensure that the present technique is simple and very accurate. Furthermore, an error analysis is performed to verify the correctness and feasibility of the proposed method when solving IDE

Quantitative measurement of amoxicillin in Ibuprofen tablets using UPLC

A novel quantitative analytical method for the determination of Penicillin contaminant, Amoxicillin in non-penicillin pharmaceutical drug product (Ibuprofen tablet 400 mg) has been developed and validated using Ultra performance liquid chromatography (UPLC). The extraction of amoxicillin from the drug tablets was carried out with bi-distilled water and the separation was achieved by making use of a BEH C18 column with particle size of 1.7 μm (100 mm × 2.1 mm). The isocratic run accomplished using phosphate buffer (pH 5.0): methanol (95:5, v/v) mixture as mobile phase run at a flow rate of 0.3 mL/min. The rapid, accurate and low cost UPLC method was proven to be suitable within the current good manufacturing practices (cGMP) of pharmaceutical ingredients. In addition, the validation of the developed method was conducted as per the ICH (International conference of harmonization) guidelines Q2 (R1). Further, the method was found to be linear in the range of (0.024–0.096 μg/mL for amoxicillin) with a correlation coefficient, R2 of 0.999 and net in terms of specificity, linearity, precision, accuracy, detection limit (DL), and quantitation limit (QL) are appeared to be satisfactory. The precision was assessed in terms of injections repeatability with a maximum %RSD of 1.8%, while the intermediate precision Day-1 with %RSD of 0.96 and the intermediate precision Day-2 with %RSD of 1.56 were observed. Thus, from the observation of satisfactory results for amoxicillin detection, the developed UPLC-based method can successfully be applied in the pharmaceutical quality control laboratories to fulfill the regulatory requirements

A Cross-Cultural Systematic Review of Vitamin D Deficiency in Women

Vitamin D deficiency has been reported in several cultures and regions, including the Middle East, North Europe, and Australia. In this review, we summarize and discuss existing studies on factors underlying vitamin D deficiency across different regions. In particular, we explain key roles played by lifestyle, including sun exposure, season change, diet, and clothing (concealing vs. non-concealing) as factors leading to vitamin D deficiency. We further discuss gender differences in vitamin D levels and, the impact of vitamin D supplements on cognition. The introductory section of this paper focuses on introducing vitamin D deficiency and highlighting the prevalence of vitamin D deficiency in Eastern countries. Here, we also provide a comparative literature analysis not only based on Eastern and Western countries but also compare the prevalence of vitamin D deficiency between males and females. Our review provides key information on potential life changes that help increase vitamin D and protect against the development of several disorders

Minimally invasive, no hardware subtalar arthrodesis with autogenous posterior iliac bone graft

Sixteen patients underwent minimally invasive subtalar arthrodesis through a mini-invasive approach with posterior iliac graft between 2004 and 2006. No hardware was used to transfix the arthrodesis and partial weight bearing was allowed immediately. The primary indication for surgery was the squeal of fracture os calcis in terms of subtalar joint arthritis, loss of heel height, malalignment of the hindfoot, and pain with weight bearing. There were 12 male and 4 female patients with a mean age of 30 (range 17–52). Patients were followed up for a period of 40.8 months (range 36–48 months). The mean interval from injury to fusion was 2 (+0.6) years ranging from 6 months to 6 years post fracture. The average clinical rating scale based on the American Orthopaedic Foot and Ankle Society (AOFAS) improved from 36 preoperatively to 78 at the latest follow-up (P < 0.05). Union rate was 94%. Radiographic evaluation revealed a mean increase in calcaneal inclination of 6.25 + 8.3° (P < 0.07) and a mean increase in the lateral talocalcaneal angle of 7.42 + 10.2° (P < 0.08). Complications were graft nonunion in 1 patient and transient tendoachilles tendinitis in another. This technique can be used to decrease the morbidity associated with the late complications of os calcis fractures by aligning the hindfoot, restoring the heel height and correcting calcaneal and talar inclination. It offers the advantage of early weight bearing while avoiding hardware complications