STATISTICAL QUALITY CONTROL AND ELECTRICAL CONDUCTIVITY FOR EVALUATION OF THE UNIFORMITY OF DIFFERENT DRIP FERTIGATION SOLUTIONS

Population growth has led to an intensified search for ways to increase the efficiency of agricultural production, including improvements of irrigation systems. The aim of this work was to evaluate the uniformity of different drip fertigation techniques, as well as their monitoring using electrical conductivity measurements and statistical quality control charts. For this, an experiment was performed according to a fully randomized design, with six treatments: T1) water (control); T2) Forth Frutas fertilizer; T3) Fortgreen fertilizer; T4) water (control); T5) Bio Bokashi liquid fertilizer; and T6) swine production wastewater. Each treatment consisted of 25 assays (replications). For the assays, 16 collection points were selected for measurements of volume, pH, and electrical conductivity. The data were analyzed using the Christiansen uniformity coefficient, the distribution uniformity coefficient, and the coefficient of variation of the total flow, employing Tukey’s test (5% level), together with statistical quality control charts. The results revealed uniformity above 90% for irrigation and fertigation, while statistically better control was obtained for irrigation. It could be concluded that irrigation and fertigation were similar in terms of uniformity, demonstrating the feasibility of using different fertigation solutions, while the control charts enabled efficient monitoring of the uniformity of the systems.

The Role of Probability Distributions in Establishing Acceptance Sampling Plans and Quality Control Charts

This paper aims at identifying the probability distributions used in controlling the quality of products of industrial companies by examining the degree of the probability distributions' efficient in strengthen the control process that, consequently, would lead companies to cope with the new technologies to overcome the difficulties and problems they counter in controlling the quality of their products. This study used discrete and continuous probability distributions and explained how they can be used in acceptance inspection plans and quality control charts by examining the inputs and outputs of the production process and the production process itself. The results of this study indicated to the use of probability distributions maintains continuous improvement in quality and checks for convergence between inputs and outputs. In addition, the use of probability distributions enhances the efficiency and effectiveness of quality control. The results of this study are of importance to managements in the manufactured companies concerning the significance of using probability distributions to control the quality of products at all stages of production. Moreover, the establishment of periodical training programs specialized in quality control, with a focus on the use of probability distributions.

THE STUDY OF THE ACCURACY AND STABILITY OF GTE NOZZLE GUIDE VANES ASSEMBLY UNITS MANUFACTURING BY THE METHOD OF SELECTIVE LASER MELTING USING QUALITY CONTROL CHARTS

This paper presents the results of a study of the accuracy and stability of GTE nozzle guide vanes assembly units manufacturing by the method of selective laser melting using quality control charts. The GTE nozzle guide vanes assembly units were made from material Inconel 738 by selective laser melting on an SLM 280HL equipment. The control of the geometric characteristics of the nozzle guide vanes assembly units that manufactured using additive technology was carried out on a coordinate measuring machine. We statistical analyzed the technological process using control charts for quantitative data and an assessment of the SLM process capabilities to meet the specified requirements. The geometry accuracy of guide nozzle blades airfoil was selected as a part quality parameter, which significantly affects the operational part characteristics. As a result of the conducted statistical analysis, it was found that the SLM process is in a state of statistical controllability with respect to internal variability, is suitable for meeting the given requirements and has a sufficient margin of capabilities necessary for effective process control. Checking the quality assurance terms for compliance with the requirements indicates that there may be geometers parameters values that lie outside the tolerance limit and, as a result, the part may be defective.