Desorption of hydrocarbon chains by association with ionic and nonionic surfactants under flow as a mechanism for enhanced oil recovery

The need to extract oil from wells where it is embedded on the surfaces of rocks has led to the development of new and improved enhanced oil recovery techniques. One of those is the injection of surfactants with water vapor, which promotes desorption of oil that can then be extracted using pumps, as the surfactants encapsulate the oil in foams. However, the mechanisms that lead to the optimal desorption of oil and the best type of surfactants to carry out desorption are not well known yet, which warrants the need to carry out basic research on this topic. In this work, we report non equilibrium dissipative particle dynamics simulations of model surfactants and oil molecules adsorbed on surfaces, with the purpose of studying the efficiency of the surfactants to desorb hydrocarbon chains, that are found adsorbed over flat surfaces. The model surfactants studied correspond to nonionic and cationic surfactants, and the hydrocarbon desorption is studied as a function of surfactant concentration under increasing Poiseuille flow. We obtain various hydrocarbon desorption isotherms for every model of surfactant proposed, under flow. Nonionic surfactants are found to be the most effective to desorb oil and the mechanisms that lead to this phenomenon are presented and discussed.Comment: 10 figures; to appear in Scientific Report

Towards automated composition of convergent services: A survey

A convergent service is defined as a service that exploits the convergence of communication networks and at the same time takes advantage of features of the Web. Nowadays, building up a convergent service is not trivial, because although there are significant approaches that aim to automate the service composition at different levels in the Web and Telecom domains, selecting the most appropriate approach for specific case studies is complex due to the big amount of involved information and the lack of technical considerations. Thus, in this paper, we identify the relevant phases for convergent service composition and explore the existing approaches and their associated technologies for automating each phase. For each technology, the maturity and results are analysed, as well as the elements that must be considered prior to their application in real scenarios. Furthermore, we provide research directions related to the convergent service composition phases

Role of the vaccum pressure and temperature in the shape of metal Zn nanoparticles

Artículo especializado en revista indexadaZinc (Zn) nanoparticles were fabricated by the high-vacuum thermal evapouration technique. The vacuum pressure was modified from 10−6 to 15 Torr and the substrate temperature was increased from room temperature to 100◦C in order to evaluate the changes in the morphological and structural characteristics of the Zn nanoparticles. Well-faceted hexagonal disk shaped nanoparticles were formed at a vacuum pressure of 10−6 Torr with the substrate kept at room temperature. Aggregation and surface irregularities at the edges of the hexagonal nanodisks were observed with further increases in the vacuum pressure. The nanoscale characteristics of the nanodisks were lost at a vacuum pressure of 10−6 Torr and heating the substrate at 100◦C. The nanodisks were transformed into Zn wires at a vacuum pressure of 15 Torr with a substrate temperature of 100◦C. It is suggested that the initial stages of the growth of the Zn wires are governed by the agglomeration of the Zn nanodisks since the structure of the wires was observed to be composed by stacked nanodisks.CONACYT and PRODEP proyecto de red 2014-201

Castor biodiesel-diesel blend to power a diesel engine: evaluation of the bus efficiency and emissions under driving conditions

Biodiesel produced from castor oil has attractive properties as this fuel can be produced from renewable energy sources without compromising food supply. A B20 castor biodiesel-diesel blend was used on a diesel engine without any other modification. A field study was conducted on a diesel school bus in the state of Morelos, Mexico, to evaluate fuel efficiency and fuel emissions from diesel and from the B20 castor biodiesel-diesel blend under bus driving conditions on the highway and in the urban area. Refined castor oil was used to produce biodiesel at pilot scale (300 liters) in compliance with the B100 ASTM D6751 standard. The results show the benefits of using castor biodiesel since, when com¬pared to diesel fuel, similar fuel efficiencies and reductions in exhaust emissions were accomplished with the B20 castor biodiesel-diesel blend. This blend represents an environmental-friendly alternative to reduce diesel consumption without threatening the food supply, because castor biodiesel is produced from wild plant oil

An Approach Based on Knowledge-Defined Networking for Identifying Heavy-Hitter Flows in Data Center Networks

Heavy-Hitters (HHs) are large-volume flows that consume considerably more network resources than other flows combined. In SDN-based DCNs (SDDCNs), HHs cause non-trivial delays for small-volume flows known as non-HHs that are delay-sensitive. Uncontrolled forwarding of HHs leads to network congestion and overall network performance degradation. A pivotal task for controlling HHs is their identification. The existing methods to identify HHs are threshold-based. However, such methods lack a smart system that efficiently identifies HH according to the network behaviour. In this paper, we introduce a novel approach to overcome this lack and investigate the feasibility of using Knowledge-Defined Networking (KDN) in HH identification. KDN by using Machine Learning (ML), allows integrating behavioural models to detect patterns, like HHs, in SDN traffic. Our KDN-based approach includes mainly three modules: HH Data Acquisition Module (HH-DAM), Data ANalyser Module (HH-DANM), and APplication Module (HH-APM). In HH-DAM, we present the flowRecorder tool for organizing packets into flows records. In HH-DANM, we perform a cluster-based analysis to determine an optimal threshold for separating HHs and non-HHs. Finally, in HH-APM, we propose the use of MiceDCER for routing non-HHs efficiently. The per-module evaluation results corroborate the usefulness and feasibility of our approach for identifying HHs

High-heat flux testing of an interceptive device for an intense proton beam

An interceptive device referred to here as a scraper has been designed and tested for use in a diagnostic device [1]. The scraper will be used to probe a proton beam in order to detect the formation of beam halo [2]. Probing the proton beam exposes the scraper to high heat fluxes on the order of 610 kW/cm{sup 2}. The high-heat flux exposure is cyclic since the beam is probed while in pulsed mode. In order to test the design repetitive high-heat flux testing has been performed on a prototype design of the scraper. This paper describes the design, analysis, and testing of the scraper

Incorporation of the UGRAFT Technique to High-definition Liposuction

Summary:. High-definition liposuction is now a reliable procedure that provides more athletic results. It is a trend among plastic surgeons and patients. The ultrasound-guided rectus abdominis fat transfer (UGRAFT) technique has expanded the range of patients who can benefit from rectus abdominis fat grafting, including those without skin laxity. Its advantage over isolated high-definition liposuction is a more natural-looking result because it increases muscle volume and provides a contoured abdomen even during movement, regardless of the patient’s position. In this article, we describe one patient undergoing the UGRAFT technique after high-definition liposuction, versus one patient undergoing only high-definition liposuction. We determined that the use of the UGRAFT technique provides greater muscle definition over those in which this technique has not been performed. The UGRAFT technique opens the possibility of developing more complete body structures regarding definition, providing volume to muscular areas. The more muscle mass and less body fat, the greater the body definition in a liposuction. The less muscle mass and more body fat, the less definition a patient will have in a liposuction. Under these principles, we improve the result by increasing the volume of muscle mass

Final mechanical design, fabrication, and commissioning of a wire scanner and scraper assembly for halo-formation measurements in a proton beam

The 6.7 MeV, 100 mA proton beam being produced in the Low Energy Demonstration Accelerator (LEDA) RFQ is being injected into a 52 magnet lattice in order to study the charged-beam phenomenon known as beam halo [1]. Quadrupole magnets in the lattice are purposely mismatched to cause or amplify halo formation in the beam. Interceptive diagnostics that consist of a thin wire and a paddle type device called a scraper are placed in the beam to obtain charge-distribution data. The charge-distribution data is used to create a current-density distribution plot of the beam at the probed location [2]. This paper describes the mechanical design, fabrication, and commissioning of the interceptive diagnostic devices and the assembly that carries them