Tolerance-based process plan evaluation using Monte Carlo simulation

In the discrete part manufacturing industry, engineers develop process plans by selecting appropriate machining processes and production equipment to ensure the quality of finished components. The decisions in process planning are usually made based on personal experience and the verification of process plans is based on physical trial-and-error runs, which is costly and time-consuming. This paper proposes to verify process plans by predicting machining tolerances via Monte Carlo simulation. The basic idea is to use a set of discrete sample points to represent workpiece geometry. The changes of their spatial position are simulated and tracked as the workpiece undergoes a series of machining processes. Virtual inspections are then conducted to determine the dimensional and geometric tolerances of the machined component. Machining tolerance prediction is completed through: (1) manufacturing error synthesis, and (2) error propagation in multiple operations. In this way, engineers can quickly screen alternative process plans, spot the root error causes, and improve their decisions. Therefore, physical trial-and-error runs can be reduced, if not eliminated, resulting in significant savings in both time and costs.     

Thermally stable phosphonium-montmorillonite organoclays

Sodium montmorillonite (MMT) was modified with several organic phosphonium salts. Organoclays with water soluble surfactants were prepared by the traditional cation exchange reaction. An alternative procedure was used to prepare organoclays with water insoluble salts. The effect of chemical composition and molecular weight of the salts on the thermal stability and basal spacing were evaluated. The phosphonium montmorillonites exhibit higher thermal stability than conventional ammonium organoclays. The basal spacing is generally larger for the phosphonium montmorillonites. These properties provide a good potential for the use of phosphonium organoclays for the synthesis of polymer/clay nanocomposites by melt processing.     

Laser-based light barrier

Design methods of a light barrier consisting of a reciprocally placed transmitter-receiver system with a continuous directional light beam are considered. An optical diagram is designed. Usage of multiple lasers in the transmitter is proposed to form a rectangular detection area. A sequential pulsed driving method is used. A detection method to find the detectors blocked by an object existing in the detection area is proposed. Light barrier detection area determination, line laser placements, photodetector array design principles, a common operation principle of sequentially pulsed lasers, reaction time obtainment, a simplified diagram, the structure of the light barrier using two line lasers, and the time diagrams explaining the operation principle are given.     

Phenolic profiles of Turkish olives and olive oils

Phenolic compound distribution of Turkish olive cultivars and their matching olive oils together with the influence of growing region were investigated. One hundred and one samples of olives from 18 cultivars were collected during two crop years from west, south and south‐east regions of Turkey. The olives were processed to oils and both olive and olive oil samples were evaluated for their phenolic compound distribution. The results have shown that main phenolics of Turkish olives were tyrosol, oleuropein, p‐coumaric acid, verbascoside, luteolin 7‐O‐glucoside, rutin, trans cinnamic acid, luteolin, apigenin, cyanidin 3‐O‐glucoside and cyanidin 3‐O‐rutinoside. Oleuropein and trans cinnamic acid were present in higher amounts among all phenolics. Principal component analyses showed that the growing region did not have drastic effect on phenolic profile of olives. The major phenolic compounds of olive oils were tyrosol, syringic acid, p‐coumaric acid, luteolin‐7‐O‐glucoside, trans cinnamic acid, luteolin and apigenin. Luteolin is a predominant phenolic compound in almost all oil samples. Total phenol concentrations of Southeast Anatolian oils were found to be lower than those of the other regions.     

Determination of 4-Allyl Resorcinol and Chavibetol from Piper betle Leaves by Subcritical Water Extraction Combined with High-Performance Liquid Chromatography

A method has been developed for the determination of 4-allyl resorcinol and chavibetol from Piper betle leaves using subcritical water extraction combined with high-performance liquid chromatography. Several important parameters, such as effect of extraction temperature, solvent, particle size, flow rate and duration time of extraction were comprehensively optimized. The method showed good linearity in the range of 0.2–30 μg/mL, good correlation coefficients 0.9999 for all studies, acceptable reproducibility (RSD 0.16-5.43, n?=?3), low limit of detection (0.1 μg/mL), satisfactory average recoveries of (92.22 to 111.05 %) from subcritical extraction with water with RSDs of 0.31 to 7.96 %whereas, the average recoveries from subcritical extraction with methanol–water ranged from (96.58 to 110.72) with RSDs of 0.79 to 8.09 %. The method exhibit high extraction yield in range of (1.51 to 34.64 % w/w) obtained from subcritical extraction with water whereas for subcritical extraction with methanol–water the yield obtained in range of (2.08 to 9.06 % w/w). It was found that subcritical extraction with water offered improved extraction efficiency in extraction of the target compounds compared to subcritical extraction with methanol–water.     

In-house validation for the determination of honey adulteration with plant sugars (C4) by Isotope Ratio Mass Spectrometry (IR-MS)

The objective of any analytical measurement is to obtain consistent, reliable, and accurate data. Validated analytical methods play a major role in achieving this goal. Although there have been many studies reporting about the isotopic compositions of honeys, little has been documented regarding the validation of these methods. In this study, an Isotope Ratio Mass Spectrometry (IR-MS) method for the determination of honey adulteration was validated in-house in terms of selectivity, stability, linearity, accuracy, repeatability, sensitivity, and recovery. This study was the first attempt to describe some important method validation parameters, such as the limit of detection (LOD), limit of quantification (LOQ), and recovery for the IR-MS studies. The LOD of the method was 0.11%, and the LOQ was 0.38% based on the percent adulteration ratio. The recovery value for spiked blank honey sample with the in-house standard was 98.57%. To evaluate the usefulness of the method, 13 different brands of honey samples were collected from markets in Turkey and analyzed. The ranges of δ¹³C values of analyzed honey samples and their protein fractions were from −12.87 ± 0.01 to −25.56 ± 0.08‰ and from −23.77 ± 0.09 to −25.98 ± 0.06‰, respectively. Adulteration was found in one honey sample.