The preservation of ancient archaeological structures calls for generic and analogous basic materials. The production and use of marble generates a significant amount of waste, which creates environmental problems. This study investigates the impacts of using waste marble powder and tuff as a replacement for conventional natural aggregate mortar with a low cement content of 5%. Compressive strength and dry density tests were conducted on all mortar specimens. Additionally, the ultrasonic pulse speed and tensile strength of mortar samples and their blends with various marble powders (5, 10, 15%, and 20%) were examined. Results show that mass, pulse speed of ultrasonic, tensile strength, and compressive tensile strengths increased as the quantity of marble powder increased. Large quantities of marble powder are needed to make restoration mortar, and this contributes to the recycling of waste marble.
During chip formation process of machining operations, thermo-mechanical loads are generated which can decrease life of cutting tool and quality of machined components. As a result, analysing the cutting temperatures and cutting tool life during milling operations can enhance productivity in process of part manufacturing using CNC machine tools. To predict the cutting tool life and cutting temperature during machining operations of AISI 1038 Carbon Steel, an application of the virtual machining system is developed. The impact of machining parameters such as cutting speed, feed rate and depth of cut on the cutting tool life and temperature are investigated in order to enhance productivity of milling operations. The modified Johnson-Cook model is used to investigate the combined influence of strain rate and deformation temperature on yield stress during alloy milling operations. Finite element analysis of milling operations is implemented to obtain the cutting temperature of the milling tool during the chip formation process. Then, cutting tool life during milling operations is predicted in order to be analyzed and maximized. The results of virtual machining system in prediction of cutting temperature as well as life of cutting tool are compared with the experimental results in order to validate the developed methodology in the study. So, an advanced virtual machining system is developed in the study in order to decrease cutting temperatures and increase cutting tool life in terms of efficiency enhancement of part production using milling operation.
The present study is aimed to investigate the dry sliding behavior of phenolic friction brake pad materials for industrial applications. Low metallic phenolic friction composites with addition copper-graphite (Cu-C) particles produced by traditional powder metallurgy methods. The friction test is carried out by pin-on-disc configuration on universal tribometer MMW-1 with hardened steel as a counterface material. The plan of experiments conducted by Taguchi’s L 27 orthogonal array on MINITAB 19.1.1 software using 3-level design model. Analysis of variance (ANOVA) was performed for predicting and analyzing the effect of design parameters like contact pressure (1.9, 5.75 and 9,6 MPa), sliding velocity (0.64, 1.57 and 2.5 m/s) and filler content (5, 10 and 15%) to tribological properties. Results of modeling and optimization of composites has showed that contact pressure has the greatest impact on the friction process following sliding distance and filler content. On the other hand, the most influential factor for the wear process was the sliding velocity, following contact pressure and finally filler content. It has also been determined that 5–10 Wt.% Cu-C filler content has an effective impact on tribological properties. The friction surface examination of the composites using a scanning electron microscope (SEM) revealed that Cu-C content has a significant effect on improving heat resistance properties.
The innate nature of polyaniline (PANI) films to visibly change its color from green to blue when exposed to basic volatile amines makes it an excellent candidate for spoilage indication. This is further studied at a low volatile concentrations where slight color changes are detected thru colorimetric image analysis. In this study, we have synthesized polyaniline films on a glass substrate and assessed the performance of the films as food freshness indicator through digital image colorimetry. The synthesized PANI films have an overall homogenous surface that is green in color. Well-dispersed globular nanostructures were revealed in the SEM micrographs. From the results of the Fourier-transform infrared (FTIR) spectroscopy and ultraviolet-visible (UV-Vis) spectroscopy, it was found that the films were in the doped emeraldine oxidation state. The RGB (red, green, and blue) color component values of the PANI film changed correspondingly with the time of exposure to spoiling milkfish samples. Moreover, based on the Pearson product-moment correlation, the green and red components best correlate with the pH values of the milkfish.
The energy created from resources that can be replenished naturally throughout time is referred to as renewable energy. Sunlight is a great source of energy that can be used for a variety of purposes, such as power generation and the conversion of solar energy into electricity. As a clean, long-lasting, and noiseless source of electricity, photovoltaic (PV) technology is attracting a lot of attention. On the other hand, solar cells have precise controllable parameters and a high level of nonlinearity. A simple example that continues to pique the curiosity of many scholars is root discovery. in order to address the intractability of the conventional photovoltaic (PV) cells model and the nonlinear transcendental equation. The purpose of this work is to describe and analyze two distinct iterative procedures for resolving solar cells' nonlinear problems in the absence of temperature. In an iterative evaluation process, the program MATLAB is used in this paper of acquiring approximations for the solutions to nonlinear equations, some hybrid experiments are constructed. Many examples numerically are tested of the new iterative method. This new method may be regarded as an alternative and promising method for solving nonlinear equations. Additionally, an analysis of accuracy and efficiency (as measured by function evaluations) demonstrates that the proposed technique Dekker's Formula (DM) is superior and has the lowest evaluation when compared to Predictor-Corrector Type (A2).
