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Drilling is a chip machining process widely used in manufacturing .The term drilling includes all methods for making cylindrical holes in a work piece with chip cutting tools. There are many applications where drilling is used, such as drilling holes in PCBs. Robotic systems are used today to perform the drilling process. A problem that affects the use of these systems is the drilling sequence, as there are usually a number of points to visit. The determination of the drilling sequence is similar to the problem of synchronization of movement and travel time. The main objective is to optimize the time and trajectory of the three axes robot equipped with an automatic drill that seeks the best performance. In this paper, we have built a genetic optimization and problem solving algorithms to shorten the machining time to drill a given group of holes and reduce machining costs in order to improve the efficiency of the machining process as well robotic machining with three axes without degradation of the precision of the movement. The results of the experiments show that the proposed approach is feasible and practical. It is particularly useful in planning and scheduling systems for real-time manufacturing processes.

Through this research, we aim to know the role of E- marketing and how it affects on the consumer buying decision in \"Condor\", the study variables were defined as: an independent variable, represented by E- marketing, and a dependent variable, represented by the buying decision. The study was conducted on Condor managers, where data was collected from the target segment (50 individuals) using a questionnaire, to achieve the study's objective, we used the SPSS, through the results, we found that E-marketing has an impact on the consumer's buing decision at Condor, we got several results, the most important is that the economic companies should focus on the use of e-marketing.

The main objective of our work is to optimize the positional and orientation error of a platform using the direct geometric model of a parallel plane manipulator robot. It is well known that the main disadvantage of parallel manipulators is the existence of singularities within its workspace, the adaptive neuro-fuzzy solution is proposed in this study. Intermediate methods have been used to determine the optimal solution. The first method is a graphical method which determines all possible positions of the platform based on the intersection of circles. The second method is the polynomial method used to calculate the coordinates of the center of gravity and the orientation of the platform. Matlab programming simulation of these methods makes it possible to find all the solutions deduced from these methods. The analysis shows that the polynomial method is the one that provides the optimal solution.

In this work, we study the parameters influencing the positioning and rotation accuracy of industrial robot manipulators. From the Denavit–Hartenberg model (standard or modified DH) and the generalized transformation matrix, position and rotation is carried out in the general case and then applied to the Puma 560 robot. To illustrate this work, a program is developed using the symbolic calculation tools of this language was developed for the calculation of the robot’s precision for given absolute uncertainties. Calculate errors positions in each case. Once the error values have been calculated and compared with other authors, we use these results to determine the influence of each parameter on the errors positions, and to see which is the most influential and secondly proposed a model that represents the analytical part of this method and gives a confidence interval of each parameter.

Macroeconomics in general has several objectives, including: the variables that explain the behaviour of groups of agents. Macroeconomics also studies the main imbalances that can occur between aggregates (inflation, unemployment, foreign trade, etc.). Similarly, macroeconomics highlights the means of achieving certain goals set by society (price stability, growth, full employment, etc.). The analysis of these means is the responsibility of public policies implemented by the public authorities. In Algeria, macroeconomic variables must be studied and implemented in a coherent manner. Thus, in order to establish and promote macroeconomic indicators for the emergence and development of the national economy, Algeria should undertake a series of structural reforms as soon as possible that are complementary and mutually reinforcing.

The COVID-19 pandemic has been a global phenomenon defined by uncertainty, fear and grief which has resulted in record high levels of stress and anxiety in the first half of 2020. It also led to an increased interest in the study of the role of belief, religion, and spirituality as responses to coping with and responding to the pandemic throughout different societal domains. This study explores the impact of anxiety and stress caused by the pandemic on Muslim academics’ subjective well-being. It also explores correlations between coping and spirituality by assessing Muslim academics’ coping strategies in overcoming stress and anxiety. To this end, this study sampled 480 Muslim academics ages 25–60 years residing in Muslim countries. The findings show a negative yet significant correlation between anxiety and well-being while also showing a positive and significant correlation between coping strategies and subjective well-being. The research also points to the role of coping strategies in reducing anxiety and stress, the resulting improvements in well-being for Muslim academics, and the mediating effect of coping strategies between anxiety, stress, and well-being for Muslim academics.

This paper presents an investigation into the machining of CFRP composites using rotary ultrasonic machining. The study aims to analyze how various process parameters influence machining performance and to identify the optimal value of cutting force. The design approach employed isolates the effects of individual characteristics and explores the interactions between them. The results of this study reveal a nuanced interplay between the investigated parameters and the mechanical behavior of carbon fiber-reinforced plastic (CFRP) during rotary ultrasonic machining (RUM). Notably, variations in vibration amplitude (VA), tool rotation speed (TRS), and feed rate (Fr) significantly influenced the cutting force exerted on the CFRP material. Surprisingly, while both VA and TRS exhibited noticeable effects on the machining process, the feed rate emerged as the predominant factor in determining optimal cutting force levels. Specifically, the data illustrate that higher feed rates led to reduced cutting forces, indicating improved machinability. This unexpected inverse relationship prompts a reconsideration of traditional assumptions about the influence of process parameters on CFRP machining. The outcomes suggest that a strategic emphasis on feed rate adjustment can mitigate cutting forces, potentially enhancing the overall efficiency and quality of CFRP machining operations. These findings carry implications for industries reliant on CFRP components, such as aerospace and automotive sectors, offering a practical guide for optimizing machining processes and advancing the broader understanding of CFRP behavior under RUM conditions. The observed trends also open avenues for further research into the intricate dynamics of material removal in composite structures.

This study focuses on the use of dredged sediment (SD) from the dam for the synthesis of a geopolymer. The samples investigated in this work were prepared by mixing micronized and calcined sediment and ground granulated blast furnace slag (GGBFS), at different percentages (10%, 20%, 30%, 40%, and 50%). Furthermore, the influence of the molarity of the NaOH solution, which was used as an activator, as well as the impacts of the (SD/GGBFS) and (SiO2/Al2O3) ratios, and the use of different activator solutions, were also examined. In addition, the effects of the curing temperature and porosity were explored The results revealed that among the NaOH concentrations studied (6M, 8M, 10M, 12M, and 14M), 12M was identified as the optimal concentration, and the optimum SD/GGBFS ratio was 70/30. In addition, variation of the ratio (SiO2/Al2O3) allowed the identification of specific proportions for different binders. Indeed, a ratio (SiO2/Al2O3) equal to 4.45 offered an optimum compressive strength of 24.86 MPa, which is significantly higher than the 13.7 MPa obtained for the geopolymer based on sediment with a SiO2/Al2O3 ratio of 3.12 and 12M NaOH. Moreover, the curing temperature of 40 °C, for a period of 48 h, gave a mechanical strength value that was higher than that obtained at room temperature. Similarly, the optimal formulations led to a significant reduction in total porosity, especially when the molarity of the NaOH solution was high, with a GGBFS percentage of 30% achieving an optimal porosity value of 12.5%. Likewise, the X-ray diffraction, infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses confirmed the formation of geopolymers with a compact structure, which paves the way for the development of innovative and sustainable eco-construction materials with a low-carbon footprint.

In this work, natural biocomposites were developed from thermoplastic starch reinforced with natural fibers extracted from the sawdust, an industrial waste. The extracted fibers were thoroughly characterized for their chemical composition. To improve the adhesion properties, the fibers were treated with 5% NaOH solution at different time intervals of 2, 4, 6, 12, 24, and 48 hours. The resulting nanofibers were characterized using infrared spectroscopy. The starch/fiber biocomposites were then prepared using extracted fibers and starch and biocomposites were characterized comrehensively. For this purpose, various compositions of starch/nanofibers biocomposite were prepared and effect of different parameters were optimized. The effect of time for alkaline treatment of the fibers (2, 4, 6, 12, 24, and 48 h), mass percentage of added fibers (3%, 6%, 10%, and 12%), and fiber sizes (200 and 500 μm) on the moisture absorption rate of the synthesized biocomposites was studied. Finally, the biodegradability study of the synthesized biocomposite films (30 mm × 30 mm) was carried out by burial in the soil, in which a slurry in different proportions was incorporated. The samples lost their shape and became too fragile and brittle after 20 days of incubation, and after 30 days of burial, a total biodegradation of the films was observed, making it difficult to differentiate from the soil