The vehicle routing problem with backhauls (VRPB) as an extension of the classical vehicle routing prob-lem (VRP) attempts to define a set of routes which services both linehaul customers whom product are to be delivered and backhaul customers whom goods need to be collected. A primary objective for the problem usually is minimizing the total distribution cost. Most real-life problems have othe...

in this article, we have investigated the role of dimethylamine (dma), tributylamine (tba), triethanoleamine (tea), trishydroxymethylamine (trizma), and hexamethyleneterraamine (hmta), in the formation of zeolitic compounds. the experiments were carried out in acidic and basic media using si/al< 10 and si/a1>10. the structure of the resulting synthetic zeolites were similar to natro davyne, amm...

Anaerobic digestion (AD) has been recently introduced as a promising technology for producing bioenergy around the world. Due to its especial characteristics, solid waste could be considered as a proper feedstock in the digester. Retention time (RT) and rate of biogas production are two major parameters affecting the efficiency of the process. The AD procedure of biogas production consists of h...

one of the causes of perturbation at vertical intakes is the happening of vortices with an air core. the vortices with an air core occur whenever the submergence of the intake is less than a critical value. anti-vortex devices and specially plates are used to avoid the negative effects of the air-core vortices. if plates are used, then the geometry of them should be studied experimentally. acco...

A lack of diversity permeates the science, technology, engineering, and mathematics (STEM) field. Under-representation within STEM fields can stifle innovation progressive approaches to future STEM. Traditional pathways focus on identifying participants who show academic promise in schools. One segment young people, youth have been ‘pushed out’ high schools, often excluded from pathways. Altern...

In this research, Sauter-mean drop diameters and the flooding behavior have been investigated experimentally in a pilot scale Kühni extraction column. The experiments were carried out in the absence of mass transfer for two different standard chemical systems. In the experiments operating parameters including agitation speed, flow rate of both liquid phases and interfacial tension have been stu...

abstract the aim of this study is laboratory investigation of nitrate reduction in water using fe/cu nano particles. in this regards, nano fe0 (54±4 nm) and fe/cu particles (75±3 nm) was synthesized and characterized by x-ray diffraction pattern (xrd), scanning electron microscope (sem) and transmission electron microscopy (tem) photographs. the effects of coating load of nano-fe0 by cu (0, 5, ...