This paper deals with minimization of tardiness in single machine scheduling problem when each job has two different due-dates i.e. ordinary due-date and drop dead date. The drop dead date is the date in which jobs’ weights rise sharply or the customer cancels the order. A linear programming formulation is developed for the problem and since the problem is known to be NP-hard, three heuristic...

Designed experiments based on a simplex mixture design were employed to explore the effects of three solvent components (water, formic acid, and aqueous acetic acid), extraction time, and extraction temperature for the automated microextraction of basic (cationic) dyes from acrylic fibers. Extractions were conducted by an automated liquid handling system, and dye extraction was evaluated using ...

A method for simultaneous determination of nine sulfonylurea herbicides in water and soil samples with solvent demulsification-dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with high perfomence liquid chromatography was established. 120 μL of 1-dodecanol as extractant and 400 μL of methanol as dispersing reagent were injected into the sample s...

Dispersive Liquid-Liquid MicroExtraction technique based on Solidification of a Floating Organic drop (DLLME-SFO) combined with flame atomic absorption spectrometry was developed for determination of thallium in water sample. An appropriate mixture of acetone and 1-undecanol was rapidly injected into an aqueous sample containing TlCl4- which forms an ion pair with bril...

A rapid, simple, and sensitive dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFOD) method coupled with UV–Vis spectrophotometry has been applied for the extraction and determination of trace amounts of aluminium. The aluminium was extracted from the aqueous media containing aluminon and cetyltrimethylammonium bromide (CTAB). After rapid injecti...

This study describes a method to determine nonsteroidal anti-inflammatory drugs (NSAIDs) in urine samples based on the use of single-drop microextraction (SDME) in a three-phase design as a preconcentration technique coupled in-line to capillary electrophoresis. Different parameters affecting the extraction efficiency of the SDME process were evaluated (e.g. type of extractant, volume of the mi...

The central role of extraction during a chemical analysis compounds a critical review of developments in the field. Thousands of articles annually list “extraction” as a key word (about 2500 articles per year when searching only keywords for English chemistry journal articles). Consequently, narrowing the topic of this review is highly selective since about 10 000 articles survived the initial ...