OpenFlow Channel Research Articles

Evaluating the performance of particle oxidation catalyst for construction equipment

The regeneration ability of diesel particulate filter (DPF) may not meet the immense power demand of construction equipment. Furthermore, few research addresses the emission control technologies for construction equipment. Therefore, this study aims to provide the potential application of diesel oxidation catalyst (DOC) and particle oxidation catalyst (POC) in terms of reducing PM, gaseous pollutants, and polycyclic aromatic hydrocarbons (PAHs) emitted from the exhaust of diesel engines without losing power. The results showed an absence of reaction on engine power when DOC + POC was installed due to the open-flow channel of the POC. Moreover, POC reduced the PM emissions by 92.4%–93.1% and for gaseous pollutants, CO was reduced by 87.2%–93.3% while HC showed 80.7%–100%. Against DPF, the PM filtration of the POC is lower however, the two Euro III diesel engines still met the Euro V standards for PM, CO, and HC. For new POC condition, a minimum of 80.9% PAH removal efficiency was shown by both engines, while lower percentages were displayed for the remaining conditions. Although, the data suggest that the POC utilized did not wane, but rather an incomplete combustion occurred which lowered the PAH removal efficiency of the other conditions. Nevertheless, the DOC + POC still managed a 33.0%–57.0% PAH mass reduction. Lastly, following the high-performance results of the engines, the same was seen on the excavator as 86.5–96.7% of PM were removed from the raw exhaust while testing its idle and action mode.

Detecting man-in-the-middle attacks via hybrid quantumclassical protocol in software-defined network

Man-in-the-middle (MitM) attacks became one of the most risk attacks on OpenFlow communication channel in software-defined networking, its detection is a very hard task due there is no authentication in OpenFlow protocol. This channel is the most important in the network and is responsible for sending the control commands from the controller to the switches, so once the OpenFlow channel is hacked, the entire network is controlled by the attacker. Therefore, we propose a complementary solution to transport layer security protocol to detect man-in-the-middle attacks based on hybrid quantum-classical protocol. Based on the hybrid protocol, an easy-toimplement authentication between controller and switches depends on quantum and classical security layers. Also, detect eavesdropping on channel depending on quantum parameters. In this paper, we implement a simulation of hybrid protocol using a software-defined networking emulator for monitoring the OpenFlow channel to detect attacks, and the results showed the ease of detecting the eavesdrop and verifying the authentication of the other party with a hybrid method to get a high level of authentication.

Enhanced Security of Software-defined Network and Network Slice Through Hybrid Quantum Key Distribution Protocol

Software-defined networking (SDN) has revolutionized the world of technology as networks have become more flexible, dynamic and programmable. The ability to conduct network slicing in 5G networks is one of the most crucial features of SDN implementation. Although network programming provides new security solutions of traditional networks, SDN and network slicing also have security issues, an important one being the weaknesses related to openflow channel between the data plane and controller as the network can be attacked via the openflow channel and exploit communications with the control plane. Our work proposes a solution to provide adequate security for openflow messages through using a hybrid key consisting of classical and quantum key distribution protocols to provide double security depending on the computational complexity and physical properties of quantum. To achieve this goal, the hybrid key used with transport layer security protocol to provide confidentiality, integrity and quantum authentication to secure openflow channel. We experimentally based on the SDN-testbed and network slicing to show the workflow of exchanging quantum and classical keys between the control plane and data plane and our results showed the effectiveness of the hybrid key to enhance the security of the transport layer security protocol. Thereby achieving adequate security for openflow channel against classical and quantum computer attacks.

Comparative Assessment of Tubular Ceramic, Spiral Wound, and Hollow Fiber Membrane Microfiltration Module Systems for Milk Protein Fractionation.

The fractionation efficiency of hollow fiber membranes (HFM) for milk protein fractionation was compared to ceramic tubular membranes (CTM) and spiral wound membranes (SWM). HFM combine the features of high membrane packing density of SWM and the more defined flow conditions and better control of membrane fouling in the open flow channel cross-sections of CTM. The aim was to comparatively analyze the effect of variations in local pressure and flow conditions while using single industrially sized standard modules with similar dimensions and module footprints (module diameter and length). The comparative assessment with varied transmembrane pressure was first applied for a constant feed volume flow rate of 20 m3 h−1 and, secondly, with the same axial pressure drop along the modules of 1.3 bar m−1, similar to commonly applied crossflow velocity and wall shear stress conditions at the industrial level. Flux, transmission factor of proteins (whey proteins and serum caseins), and specific protein mass flow per area membrane and per volume of module installed were determined as the evaluation criteria. The casein-to-whey protein ratios were calculated as a measure for protein fractionation effect. Results obtained show that HFM, which so far are under-represented as standard module types in industrial dairy applications, appear to be a competitive alternative to SWM and CTM for milk protein fractionation.

A comparison on the dynamical performance of a proton exchange membrane fuel cell (PEMFC) with traditional serpentine and an open pore cellular foam material flow channel

Minimising the pressure drop in flow channels, ensuring high efficiency and utilisation of open pore cellular foam (OPCF) material in place of a traditional serpentine channel are investigated in this work. The paper establishes novel mathematical model that takes into account the effect of pressure drop in the flow channel and compares the dynamics of a porous flow channel with those of the traditional serpentine flow channel. The performance of a Polymer Electrolyte Membrane fuel cell with porous foam flow channel is analysed under static and transient conditions. The fuel cell mass transport equations are used in the model that also takes into account the effect of varying the current on the stack temperature. The membrane water content and IV-curves are analysed and simulation results are presented based on the mathematical models of the proposed system using the MATLAB®/Simulink® environments. The effect of varying pore diameter, porosity, and the flow velocity on pressure drop are also investigated using sensitivity analysis. Due to the lower pressure drop provided by the uniform distribution of reactants in OPCF channel, an improvement of approximately 55% is observed in current density when compared with that of the serpentine channel under the same operating conditions. The investigation further concluded that a higher pore diameter can have a lower drop in pressure provided the flow velocity of the reactant does not exceed 6 m/s.

Numerical Simulation for Interaction between the Fracture Surface and the Proppant Column after HiWay Fracturing

HiWay fracturing uses impulse sand to achieve the proppant column supporting the rock wall surface, creating an open flow channel that is more conducive to improving the stimulation effect. The deformation law of the proppant column under the compression of the fracture wall surface is directly related to the effectiveness of the high conductivity fracture. However, the related laboratory physical simulation experiments are challenging to conduct, which restricts the study of the interaction between the fracture surface and the proppant column. In this paper, first, establish the finite element model of the interaction between the fracturing crack and the proppant column, and the variation law of stress-deformation of the crack wall and displacement of the crack wall under the closure stress is analyzed. Furthermore, this paper carries out the quantitative characterization of the active support area of the proppant column. Finally, the accuracy of the simulation results is verified by applying the experimental results of indoor proppant column rock plate compression. The numerical simulation method proposed in this paper can effectively realize the simulation of the interaction between the fracture surface and the proppant column in HiWay fracturing based on real engineering parameters, which lays theoretical and simulation experimental support for improving the effect of channel fracturing stimulation.

Software Defined Networks – OpenFlow Channel Security and Efficiency

Software Defined Networks – OpenFlow Channel Security and Efficiency

The supply of total nitrogen and total phosphorus from small urban catchments into the Gulf of Gdańsk

The main goal of work was to quantify the nitrogen and phosphorus loads transported by small streams to the Gulf of Gdańsk. The research aims to determine wastewater release volumes over time, instead of focusing only on spatial distributions. Another aim is to identify the main determinants potentially affecting water quality in rivers flowing across the city of Sopot. The study area consists of six small river catchments located in the city of Sopot, each with an open flow channel, which lies along the bay. Studies were conducted 12 times per year in the period from March 2014 to February 2015. Laboratory analyses were performed to determine the concentration of both total nitrogen and total phosphorus. In order to calculate pollutant loads, discharge was also measured in each of studied rivers. Conducted research has shown that all analyzed streams were characterized by low total nitrogen and total phosphorus concentrations. The mean annual values ranged from 0.60 to 1.28 mg·dm-3 in case of total nitrogen and from 0.066 to 0.100 mg·dm-3 in case of total phosphorus. In 2012, the total nitrogen load from Poland to the Baltic Sea was 210.768.000 kg N while the total phosphorus load was 15.269.000 kg P, which means that streams analyzed in this paper supplied barely 0.002 % of the biogenic load supplied to the Baltic Sea by Poland as a whole.

FLOW VELOCITY MEASUREMENTS IN THE OPEN CHANNELS

This study aimed at determining dependencies between incident wave height and flow velocity in open flow channels by utilizing computer vision algorithms. Authors use computer modeling and experimental studies to check possibilities of flow velocity measurement by measuring incident wave height in front of semi-submerged artificial obstacle placed in the open flow channel.

Maxing Out Water Desalination with MXenes

In this issue of Joule, Guoxiu Wang, Yury Gogotsi, and collaborators design and synthesize highly porous MXene electrodes that are resistant to nanosheet restacking and deliver high electroadsorption capacity for capacitive deionization (CDI) of saline water. In CDI cells constructed with aerogel-like Ti3C2Tx MXene electrodes, an adsorption capacity of 118 mg/cm3 (45 mg/g) was achieved in a 10,000 mg/L salt solution, more than one order of magnitude greater than carbon-based electrode materials.

Packet Injection Attack and Its Defense in Software-Defined Networks

Software-defined networks (SDNs) are novel networking architectures that decouple the network control and forwarding functions from the data plane. Unlike traditional networking, the control logic of SDNs is implemented in a logically centralized controller which provides a global network view and open programming interface to the applications. While SDNs have become a hot topic among both academia and industry in recent years, little attention has been paid on the security aspect. In this paper, we introduce a novel attack, namely, packet injection attack, in SDNs. By maliciously injecting manipulated packets into SDNs, attackers can affect the services and networking applications in the control plane, and largely consume the resources in the data plane. The consequences could be the disruption of applications built on the top of the topology manager service and rest API, as well as a huge consumption of network resources, such as the bandwidth of the OpenFlow channel. To defend against the packet injection attack, we present PacketChecker, a lightweight extension module on SDN controllers to effectively detect and mitigate the flooding of falsified packets. We implement a prototype of PacketChecker in floodlight controller and conduct experiments to evaluate the efficiency of the defense mechanism. The evaluation shows that the PacketChecker module can effectively mitigate the attack with a minor overhead to the SDN controller.

Securing SDN Infrastructure of IoT–Fog Networks From MitM Attacks

While the Internet of Things (IoT) is making our lives much easier, managing the IoT becomes a big issue due to the huge number of connections, and the lack of protections for devices. Recent work shows that software-defined networking (SDN) has a great capability in automatically and dynamically managing network flows. Besides, switches in SDNs are usually powerful machines, which can be used as fog nodes simultaneously. Therefore, SDN seems a good choice for IoT–Fog networks. However, before deploying to IoT–Fog networks, the security of the OpenFlow channel between the controller and its switches need to be addressed. Since all the controller commands are sent through this channel, once compromised, the network will be completely controlled by an attacker. This is a disaster for both the network service providers and their customers. Previous works on SDN security either protect controllers themselves or make a strong assumption that the OpenFlow channel is already secured. Using TLS to encrypt the channel is not a “silver-bullet” solution due to the known TLS vulnerabilities. In this paper, we specifically investigate the potential threats of man-in-the-middle attacks on the OpenFlow control channel. We first introduce a feasible attack model in an IoT–Fog architecture, and then we implement attack demonstrations to show the severe consequences of such attacks. Additionally, we propose a lightweight countermeasure using Bloom filters. We implement a prototype for this method to monitor stealthy packet modifications. The result of our evaluation shows that our Bloom filter monitoring system is efficient and consumes few resources.

Ex-situ probing of PEFC liquid droplet dynamics in the presence of vibration

PEFC performance degradation when exposed to vibration has been attributed to liquid water redistribution; however, fundamental liquid droplet behavior under such conditions is not well understood. As this technology continues to penetrate automotive, aerospace, and marine markets, where vibration and mechanical shock may be common, it is necessary to characterize droplet dynamics under such conditions. This work uses ex-situ experimental techniques to study the effects of sinusoidal vibration on water and gas-diffusion layer interactions for open cathode and flow channel based designs. Parameters such as contact angle, key droplet dimensions, adhesion force, and detachment velocity were measured for a range of frequencies and amplitudes. Vertical and horizontal oriented cells were investigated. The results show that vibration can significantly impact wetting; in some cases, increasing the barrier for liquid removal. Sessile droplet contact angle and dimensions such as height and wetting diameter, shifted toward more hydrophilic wetting under elevated frequency. Droplet detachment velocities were measured to be higher at 100 Hz then at 0 Hz for air speeds up to 10 m s−1. These results may be of interest to PEFC modelers and flow-field designers.

Sweat Lactic Acid Monitoring System for Assessment of Exercise Intensity

A microfluidic lactic acid (LA) monitoring system for in-situ monitoring of LA excretion in sweat was fabricated and tested. Our system consists of a micro flow-cell made of PDMS with open flow-channel for sweat sampling and a LA biosensor using redox reaction. The micro flow-cell was fixed on the skin’s surface to connect eccrine sweat gland and micro-channel. Phosphate buffer saline (PBS) was supplied into the flow-channel as carrier flow for transporting whole sweat contents to the biosensor. Continuous monitoring of LA at the skin’s surface was conducted during cycling exercises and intervals. Intensity of the exercises were regulated by heartrates (HR). As a result, secretion of LA was confirmed when the intensity of exercise was high (HR: 159 bpm) and the signal decreased after the exercise. Similar results were obtained in the arm muscle training measurement. This indicates that our system was suitable for the assessment of exercise intensity.

Performance Prediction of Darrieus-Type Hydroturbine with Inlet Nozzle Operated in Open Water Channels

Small hydropower is one of the renewable energies and is expected to be effectively used for local supply of electricity. We have developed Darrieus-type hydro-turbine systems, and among them, the Darrieus-turbine with a weir and a nozzle installed upstream of turbine is, so far, in success to obtain more output power by gathering all water into the turbine. However, there can several cases exist, in which installing the weir covering all the flow channel width is unrealistic, and in such cases, the turbine should be put alone in open channels without upstream weir. Since the output power is very small in such a utilization of small hydropower, it is important to derive more power for the cost reduction. In the present study, we parametrically investigate the preferable shape of the inlet nozzle for the Darrieus-type hydroturbine operated in an open flow channel. Experimental investigation is carried out in the open channel in our lab. Tested inlet nozzles are composed of two flat plates with the various nozzle converging angles and nozzle outlet (runner inlet) widths with the nozzle inlet width kept constant. As a result, the turbine with the nozzles having large converging angle and wide outlet width generates higher power. Two-dimensional unsteady numerical simulation is also carried out to qualitatively understand the flow mechanism leading to the better performance of turbine. Since the depth, the width and the flow rate in the real open flow channels are different from place to place and, in some cases from time to time, it is also important to predict the onsite performance of the hydroturbine from the lab experiment at planning stage. One-dimensional stream-tube model is developed for this purpose, in which the Darrieus-type hydroturbine with the inlet nozzle is considered as an actuator-disk modelled based on our experimental and numerical results.

An evolvable, scalable, and resilient control channel for software defined wireless access networks

This paper presents a novel multipath communication-based OpenFlow channel for Software Defined Wireless Access Networks (SDWANs), namely mOpenFlow. The advantageous features of mOpenFlow include the following: (i) resilience and scalability in wireless environments, (ii) evolvability of the existing access networks and the OpenFlow standard, (iii) a novel network calculus-based model for performance analysis of mOpenFlow. By leveraging the multipath communication for conveying OpenFlow traffic, mOpenFlow enhances both robustness (i.e., resilience) and throughput (i.e., scalability) of the control channel. To achieve the evolvability, mOpenFlow adopts the multipath transport control protocol, which conforms to SDWANs and the OpenFlow standard. We evaluate mOpenFlow in an emulated SDWAN in relation to the standard channel. The results show that mOpenFlow outperforms the standard channel, both in terms of robustness and scalability. Additionally, the numerical results indicate that the model provides a fast and reliable way for analyzing the end-to-end delay on mOpenFlow.

Sweat Lactic Acid Monitoring System for Assessment of Exercise Intensity

A microfluidic lactic acid (LA) monitoring system for in-situ monitoring of LA excretion in sweat was fabricated and tested. LA is a chemical substance that is widely distributed in human body and it is known as a marker of metabolism which reflects the exercise intensity. For this reason, blood LA is often used in the conditioning of elite athletes. However, it is still difficult to be used in the public sports, or daily diet because blood sampling is requested for blood LA determination. On the other hand, eccrine sweat is known as a biomarker-rich body fluid that is one of the most promising candidate for non-invasive biomonitoring. Previously numbers of wearable devices that measures ionic solutes in sweat (Cl-, K+, Mg2+, NH4+, and Zn2+) or other contents such as glucose or lactic acid. Although this sort of devises has been intensively investigated, there are several struggle points to be cleared for practical use. One of the most significant challenge is to stabilize the baseline of the signal. Since a part of sweat fluid immediately evaporates from the skin surface, the concentrations of sweat contents are influenced by the humidity or the secretion volume (i.e. surface area). Our approach to solve this problem is using an open flow-channel fixed on the skin surface for transporting whole sweat contents to the sensing devise. Our system consists of two elements: a printed biosensor for LA based on a redox reaction of osmium wired horseradish peroxidase (Os-HRP) with a flexible micro flow channel formed using PDMS, and a sampling devise with the open flow-channel. We used polyethylene terephthalate (PET) as a substrate material of the biosensor and printed carbon graphite electrodes on the substrate by conventional screen printing method. Owing to the Os-HRP redox reaction, the sensor is operated under the low potential of 0V vs. silver / silver chloride electrode, which is possible to reduce the effect of interferences such as uric acid. The biosensor has four electrodes (working electrode on which lactate oxidase (LOD) is immobilized, working electrode without LOD, silver / silver chloride reference electrode and counter electrode). LA is measured by amperometric method as a change of hydrogen peroxide which is produced by enzymatic reaction of LOD. For accurate sensing, differences of output signals between LOD electrode and electrode without LOD was recognized as an output current. Characterization of the biosensor was first conducted using standard LA solution. As a result, the biosensor had sufficient sensitivity (LA : 0.13nA µM-1) for monitoring of skin’s surface lactic acid continuously. The linear detection range was 10 µM -1.0 mM which contained the sweat LA level diluted in the PBS career flow. Selectivity to LA was also investigated. The biosensor showed sufficient selectivity (> 40.5) towards 0.5 mM LA under the presence of uric acid, urea, ammonia, glucose, ethanol (0.5 mM), because of specific activity of LOD from Aerococcus viridans. Continuous monitoring of LA at the skin’s surface was also carried out. First, the PDMS flow-cell with an open flow-channel (1 mm wide and 20 mm long) was attached on the surface of the upper arm of healthy male volunteer. Phosphate buffer saline (PBS) was supplied into the flow-channel as carrier flow and the flow rate of PBS was regulated at 10 µL min-1. Excreted sweat content was solved into the PBS and transported to the biosensor. Monitoring of LA was conducted during a cycling exercise (20 min) and interval (20 min). Intensity of the exercises were adjusted by monitoring heartrates. As a result, elevation of the output signal was confirmed during the exercises and the signal decreased to the background level during the intervals (Figure). The output current of LA increased to 24.2 nA during the workout (heartrate : 160). This indicates that our system was suitable for continuous monitoring of exercise intensity. It is also possible to employ bluetooth-interface to construct of a wireless system. Design and characteristics of the monitoring system, and the latest results of in-situ LA monitoring at the skin’s surface during the ‘bike’ exercises will be presented at the meeting. Figure 1

Leaf protein concentration of alfalfa juice by membrane technology

Membrane technology (microfiltration (MF) and ultrafiltration (UF)) of alfalfa juice was studied as an alternative method to conventional leaf protein concentration. Three types of filtration modules (dead end filtration using laboratory Amicon cell (DA), dynamic cross filtration using rotating disk module (CRDM) and dead end filtration using rotating disk module (DRDM)) were used to investigate concentration efficiency of MF and UF with full recycling tests and concentration tests. Rotating speed and transmembrane pressure (TMP) improved flux behavior, but higher permeate flux caused by higher rotating speed reduced leaf protein rejection of MF. The strong rotating shear effect and open flow channel structure of CRDM could control concentration polarization and membrane fouling, therefore, it gave the best flux behavior, least flux decline, best clarification effect, smallest irreversible fouling and highest permeability recovery in membrane cleaning. However, the best leaf protein rejection was obtained by DRDM, because of high shear rate and “secondary filtration” of fouling layer created by closed flow channel structure. Besides, CRDM showed the highest productivity and best potential for industrial application. These results from laboratory-scale tests can be very useful for concentrating leaf protein from alfalfa juice and serve as a valuable guide for process design in industrial scale.

Theoretical analysis of high flow conductivity of a fracture induced in HiWay fracturing

HiWay (or channel) fracturing has been a new technology for development of unconventional oil and gas resources in recent years. It has been carried out more than 4000 times worldwide, and obtained good performance in oil and gas recovery. HiWay fracturing improves the flow conductivity of fractures by constructing inhomogeneous distributions of proppant and stable, open flow channel in hydraulic fractures. However, the mechanism and impact factors of high flow conductivity of HiWay fractures are not very clear. To the best of our knowledge, there are no relevant research reports available for such analysis. In this paper, it is first assumed that the fluid flow in proppant clusters follows the Darcy's law and the flow in the channels with proppant clusters is laminar viscous flow, which can be described using Stokes equation. However, the coupling of Darcy-Stokes equations is difficult, and some untrivial interface conditions at the interface between the porous and free-flow regions should be introduced, this will increase greater complexity in numerical computation. As an alternative approach, the Darcy-Brinkman equation is often used for this coupling flow problem, which provides a unified equation with continuous variable coefficients in the two different flow regions. Therefore, there is not necessary to introduce specific interface conditions any more. In this work, we first applied the Darcy-Brinkman equation to model the fluid flow in hydraulic fractures, and then the upscaling of Darcy-Brinkman equation is conducted to evaluate the equivalent permeability of a fracture by using homogenization theory and finite element numerical simulation. Finally, various impact factors of flow conductivity of a hydraulic fracture, such as the cluster shape, cluster distribution, cluster size, etc., are analyzed based on the equivalent permeability. Results show that the permeability of a hydraulic fracture is considerably greater than thst of proppant cluster when the free-flow region is well connected in the fracture, and the geometric properties of proppant clusters are also the key influencing factors for the flow conductivity. Therefore, in HiWay fracturing process, how to construct the well-connected free-flow region in hydraulic fractures is most important, and the flow conductivity of proppant cluster is not the keypoint. However, the surface roughness and stress sensitivity of the hydraulic fractures have not been considered in this work, it will be considered in the future work.

Measures of mixing quality in open flows with chaotic advection

We address the evaluation of mixing efficiency in experiments of chaotic mixing inside an open-flow channel. Since the open flow continuously brings new fluid into the limited mixing region, it is difficult to define relevant mixing indices as fluid particles experience typically very different stretching and mixing histories. The repeated stretching and folding of a spot of dye leads to a persistent pattern. We propose that the normalized standard deviation of this characteristic pattern is a good measure of the mixing quality of the flow. We discuss the link between this measure and mixing of continuously injected dye, and investigate it using an idealized map.