Transparent Core Research Articles

Multifactorial performance comparison of WDM fully transparent core networks fitted with 96 GBd or 130 GBd transponders

Multifactorial performance comparison of WDM fully transparent core networks fitted with 96 GBd or 130 GBd transponders

Characterization of two-phase flow in a faulted sandstone

Fault zones present in some underground CO2 storage formations can impact on injectivity, storage capacity, and the path taken by migrating CO2, including possible leakage to overlying formations and the escape of a plume beyond the area of a demarcated storage lease licence. A thorough understanding of the 2-phase flow in fault zones is therefore essential to de-risk any storage location where faults could be present. Many previous studies have addressed top-seal risks from fault reactivation, but the influence of intra-reservoir faults on flow within the target storage formations has received less attention. Studies of intraformational faults in sandstones have typically used plugs cored from outcrops or from subsurface boreholes, where important aspects of the geological history such as the stress conditions during faulting, and the degree of post-faulting compaction and cementation may be poorly constrained. Moreover, only intact fault rocks can be cored and re-loaded under stress with this approach, so that it is very difficult to establish the interacting effects or rock fractures and cataclastic gouge in a single experiment using borehole/outcrop samples.This study investigates newly created fault rock in sandstone that has been deformed under controlled conditions and without the effects of secondary cementation. We used a large direct shear rig to deform a large, water-saturated Bentheimer sandstone block to sufficient displacement (40mm) and under enough overburden pressure (25 MPa) to create a zone of cataclastic gouge several mm thick bounded by a damage zone of fractured rock. The sheared block was cored at an inclined angle while deep frozen to extract an oriented plug containing a complete and intact section of fault rock that could be reloaded under hydrostatic conditions in an x-ray transparent core holder. The faulted plug of Bentheimer was used for running steady-state drainage and imbibition 2-phase flow experiments. The fluid saturation and its spatial distribution in 3D inside the faulted plug were dynamically monitored during all stages of the experiment in a medical x-ray CT scanner.Analysis of the flow patterns revealed from the X-ray CT images collected over time enables us to characterize in detail, the influence of recently formed fault core and damage zones on fluid flow both during drainage as gas breaks across the fault zone, and as water re-invades during imbibition. The fault core acts as a semi-permeable membrane that is only permeable to the wetting phase (water) under pressure differentials less than the capillary entry pressure (Pce) of the membrane. During drainage stages, the high Pce of the fault core led to backfilling of the upstream end of the core and almost to compartmentalization of the sample. The fracture network that exists in the damage zone played a critical role in keeping the upstream side of the fault core connected to the downstream side. During imbibition stages, the high Pce of the fault core led to significant gas trapping at the upstream side of the fault core adjacent to the fault core-damage zone interface. While the fault core formed a barrier to flow, the fracture network can provide bypass pathways for gas flow. In this particular sample bypassing through fractures was sufficient such that for a particular value of average gas saturation the flow rate was faster in the faulted rock than in the unfaulted reservoir rock.

Influence of Optic Cable Construction Parts on Recovery Process after Gamma Irradiation

Fibre optic cables are widely used as communication cables in Instrumentation and Control (I&C) systems. In the case of nuclear power plants (NPPs), using optic cables in mild environments outside of containment areas are very common. However, at present, there is a need for fibre optic cables to be used in containment areas, i.e., with radiation. An optical fibre consists of a highly transparent core that possesses a higher refractive index than the surrounding transparent cladding, which possesses a lower refractive index. Most optical fibres are manufactured from glass (silica with required dopants) which is created at high temperatures from the reaction between gasses. The glass used in optical fibres is sensitive; it becomes dark during exposure to radiation, which compromises the optic functions. That is why there has been a slow infiltration of optic cable in NPP containment areas. Radiation resistant optic fibres have been developed. Although these fibres are called “radiation resistant,” they go through a darkening process (absorbance increase) as well, but not as quickly. Immediately after the irradiation has stopped, a recovery process starts in the glass structure. During this period, optical losses of the glass improve, but not to the original level as before the irradiation. During the testing of optic cables for the installation in nuclear power plant containment areas, we observed an unusual recovery process. In the beginning, a healing effect was observed. However, after a few days of recovery, the healing process stopped, and the trend changed again as a worsening of the optical properties was observed. This paper describes experiments which explain the reasons for such an unexpected behaviour.

Filiform projections of the vestibular mucosa: What’s your diagnosis?

29-year-old recently married woman was reffered by her gynecologist to our dermatology department for suspected vulvar condyloma acuminatum. She had no history of any extramarital sexual contacts and her partner was free of any clinical features of genital HPV infections. She was anxious about the origin of her lesions and the risk of her husband’s contamination. She reported burning sensation, irritation and vulvar pain. On clinical examination soft digitate mucous colored papules with a smooth surface were noted at the vulvar vestibule. These papillomatous projections were pearly, uniformly arranged and had separate bases (Fig. 1). Dermatoscopy demonstrated regular and linear pinkish projections arranged in a symmetric distribution. Irregular linear vascular channels were observed (Fig. 2). Figure 1: Clinical aspect: multiple skin-colored filiform and soft projections. Figure 2: Dermatoscopy showing regular and linear pinkish projections arranged in a symmetric distribution. WHAT’S YOUR DIAGNOSIS? ANSWER: Vestibular Papillomatosis Vestibular papillomatosis (VP) is a normal variant of the female genital mucosa [1,2]. It is first described in 1981 by Altemeyer and named pseudocondylomata of the vulva [3]. VP is frequently misdiagnosed as condyloma acuminatum and presents a source of anxiety in patients, aggressive investigations and inappropriate treatment [2]. This entity is most often asymptomatic, but it can be accompanied, as our case, by a feeling of burning, pain or dyspareunia. To avoid the misdiagnosis of VP as genital warts, Moyal-Barranco et al. had proposed five clinical parameters [4]. Unlike condyloma acuminatum, VP is formed by regular, soft and pink-colored papillae arising from a separate base. It is also characterized by the lack of circumscribed whitening on 5% acetic acid application. Dermoscopy can help to differentiate these two conditions by allowing a better identification of these clinical parameters. Linear vessels may sometimes be observed in the transparent core of the finger-like projections [5]. On the other hand, dermoscopy of condyloma acuminatum shows irregular whitish projections with tapering end that arise from a common base and comprise conglomerate vessel. Based on these clinical criteria and the dermoscopic aspect, biopsies will be unnecessary to confirm the diagnosis of VP.

Tools for pressure core sub-coring and pore-scale micro-CT (computed tomography) scans

Abstract. The pore habits of gas hydrate in natural sediment matrices provide essential clues for understanding physical (mechanical, thermal, hydraulic, and electrical) properties of hydrate-bearing sediments, yet there are no tools that can directly visualize the pore habits of natural gas hydrate other than indirect interpretation based on core-scale or field-scale observations. A significant challenge is to obtain a mini-core from pressure cores retrieved from natural reservoirs for high-resolution micro-CT (computed tomography) scans while maintaining pressure and temperature conditions required for stability of gas hydrate during all operational steps including manipulation, cutting, transferring, sub-coring and CT scanning. We present a new set of tools for pore-scale micro-CT imaging of natural hydrate-bearing sediments while maintaining pressure and temperature control. The tests with laboratory-prepared cores and pressure cores successfully demonstrate the capability of this set of tools to subsample a mini-core from pressure cores, transfer the mini-core to an X-ray transparent core holder, and conduct micro-CT scans. Successfully obtained CT images prove the functionality of this set of tools.

Fabrication of Stretchable and Transparent Core–Shell Polymeric Nanofibers Using Coaxial Electrospinning and Their Application to Phototransistors

Abstract1D semiconducting nanomaterials are promising candidates for wearable electronic devices, in which variability of form (i.e., flexibility and stretchability) is a crucial factor for achieving stable operation during a user's physical activity. Although many stretchable 1D electronic materials have been suggested, they mainly rely on structural engineering, rather than the intrinsic stretchability of the materials, and hence suffer from electrical instability under mechanical deformation. In this work, stretchable core–shell polymeric nanofibers (NFs) are fabricated using coaxial electrospinning. The stretchable core–shell NFs, which consist of a stretchable core and a semiconducting shell, provide both mechanical robustness and superior electrical properties under external strain. The stretchable core–shell NF‐based transistors show high operational stability at up to 30% mechanical strain. Furthermore, fully stretchable organic field‐effect transistors fabricated using core–shell NFs and stretchable conductors exhibit stable operation and high optical transparency (71% of transmittance at a wavelength of 550 nm). The core–shell NFs also exhibit excellent optoelectronic properties, including a maximum light responsivity (R) of 84.2 A W−1 and an external quantum efficiency (EQE) of 178.6%, under illumination at a wavelength of 585 nm. The results demonstrate a viable approach to fabricating wearable electronic devices using stretchable core–shell polymeric NFs.

The Defect-Impurity Composition of Diamond Crystals with 〈100〉 Growth Pyramids from Placers of the Krasnovishersk District, the Urals

Abstract—The internal structure and spectroscopic features of cuboid diamonds from recent alluvial placers of the Krasnovishersk District (the Urals) have been investigated. Crystals were divided into four groups by their anatomy and spectroscopy: cuboids of the II group (according to the Yu.L. Orlov classification): cuboids with a transparent core and peripheral zone saturated with inclusions; crystals with mixed habit growth of 〈100〉 and 〈111〉 pyramids, and crystals with the sequential growth of 〈100〉 and 〈111〉 pyramids. In all studied crystals, the regenerative formation of the {111} face steps together with the formation of tetragonal pits on the cuboid surface was the last stage of growth. Local photoluminescence investigations have been carried out for all cubic diamond crystals of the Urals for the first time. It was established that luminescence bands at 926 and 933 nm are related to growth pyramids of 〈100〉 and 〈111〉, respectively. Bands with peaks at 800, 820.5, 840, 860, and 869 nm were revealed in the luminescence systems of the cuboids of II group. We note that the cuboid diamonds from different regions of the world have similar internal structures and spectroscopic features.

Digital and experimental rock analysis of proppant injection into naturally fractured coal

Proppant-laden fluid injection has been applied to many low permeability reservoirs, such as coal seams, to enhance permeability and thus production. While there are several laboratory-scale experimental studies on proppant placement in hydraulic fractures, the possible infiltration of proppant into natural fractures and its effect on overall permeability has received little attention. We study proppant injection into a naturally fractured coal sample by a combination of experimental and digital rock technologies. The sample was imaged using a helical X-ray computed tomography (micro-CT) scanner in as-received condition. Then, proppants of different size ranges were gradually injected into the sample, using a purpose-built X-ray transparent core flooding system, and the permeability was measured at different effective stresses. Subsequently, the propped sample was re-imaged and registered to the as-received image to map the internal changes. The experimental results indicated almost no permeability change of the sample after proppant injection. While proppant collection in the outlet proved passage of the proppant through the sample, observation of the sample indicated that some of the proppants were accumulated on the inlet face of the core and created a filter leading to no permeability increment. Micro-CT images confirmed that proppants were effectively placed in the sample and kept the fractures open. Numerical computation of permeability, using the digital coal sample in which accumulated proppants at the coal surface were excluded, indicated a significant increase in the sample permeability. Such an increase resulted from the opening of the fractures, particularly in the outlet region. This demonstrated the significance of proppant size selection for coal seam hydraulic fracturing. While proppants were successfully placed in the fractures, the experiment measured the permeability of the system, including proppants accumulated on the inlet, and could not effectively map the internal changes. This, therefore, needs to be considered when an experimental program for proppant injection is executed. To accurately monitor the internal changes, application of digital rock technology is recommended for such experiments.

Construction and Evaluation of Collagen-Based Corneal Grafts Using Polycaprolactone To Improve Tension Stress.

The emergence of innovative surgical procedures using partial thickness corneal transplant has created a need for the development of corneal grafts to replace pathologic corneal tissue. Corneal repair materials have been successfully prepared in the past 10 years, but they were difficult to be used in clinics because of the unbearable tension caused by interrupted suture during routine surgery. However, polycaprolactone (PCL), a medical polymer material, can solve this problem. Therefore, a hierarchical collagen (Col)-based corneal graft with curvature, consisting of a transparent core part composed of collagen in the center and a mechanically robust fixed part containing collagen and polycaprolactone in the edge, was used as a potential corneal graft for corneal repair and regeneration in this study. The hierarchical collagen-based corneal grafts [collagen–polycaprolactone (Col–PCL) membranes] that are capable of mimicking the native cornea were developed based on chemical and thermal crosslinking mechanisms. The water adsorption of Col–PCL membranes could reach over 80% similar to that of human cornea, and its swelling could reach over 400%. More importantly, the formed Col–PCL membranes could resist a larger tensile strength (1.1 ± 0.03 MPa) before rupturing in comparison with pure collagen membranes and polycaprolactone membranes. Furthermore, the biodegradable Col–PCL membranes could facilitate cell adhesion and proliferation as well as cell migration (exhibiting epithelial wound coverage in <5 days), which showed promise as corneal grafts for cornea tissue engineering.

Synchrotron X-ray tomographic characterization of microstructural evolution in coal due to supercritical CO2 injection at in-situ conditions

Microstructural evolution in coal due to CO2 injection directly influences the gas transport and storage properties of coal during CO2 sequestration in deep coal seams. Using synchrotron X-ray tomography, we performed CT imaging under simulated reservoir conditions with a novel X-ray transparent core holder and investigated the time-dependent evolution of 3-D microstructures of an anthracite coal with 1.37% moisture as-received interacted with supercritical CO2 (ScCO2). Three sets of CT scans were taken: (1) coal was subjected to 10 MPa confining pressure before exposed to ScCO2, (2) coal was subjected to 10 MPa confining pressure and after 7 h of exposure to ScCO2, and (3) coal was subjected to 10 MPa confining pressure and after 53 h of exposure to ScCO2. When ScCO2 interacts with coal, complex physico-chemical reactions occur, changing coal microstructures in multiple ways and resulting in significant permeability changes. After 7 h ScCO2 injection, we directly observed the pre-existing microfracture closure, which was attributed to coal swelling. A significant permeability reduction was measured from 3.0 to 0.24 µD with up to 26 h CO2 injection. With increasing injection duration, interestingly, we observed the wormhole growth in coal due to hydrocarbon mobilization and mineral dissolution, which accordingly caused a permeability rebound to 1.2 µD after 53 h CO2 injection. Coal swelling occurred readily upon ScCO2 injection but hydrocarbon mobilization and mineral dissolution were delayed to affect the permeability probably due to the slower reaction kinetics. This study suggests that ScCO2 injection has the potential to improve the permeability and enhance the coalbed methane recovery due to the effects of hydrocarbon mobilization and mineral dissolution.

Spatial Mapping of Fracture Aperture Changes With Shear Displacement Using X‐ray Computerized Tomography

AbstractThe shearing of fractures can be a significant source of permeability change by altering the distribution of void space within the fracture itself. Common methods to estimate the effects of shearing on properties, such as aperture, roughness, and connectivity, are incapable of providing these observations in situ. Laboratory protocols are needed that enable measurements of the spatial structure of the fracture aperture field in the medium, noninvasively. Here, we investigate changes in rough‐walled Brazilian‐induced tensile fracture aperture distribution with progressive shear displacement in Westerly granite and Carrara marble using a novel X‐ray transparent core holder. The so‐called calibration‐free missing attenuation method is applied to reconstruct highly resolved (submillimeter) fracture aperture maps as a function of displacement (0 to 5.75 mm) in induced fractures. We observe that shearing increases the core‐averaged fracture aperture and significantly broadens the distribution of local values, mostly toward higher apertures. These effects are particularly strong in Westerly granite and may be the result of the higher initial roughness of its fracture surfaces. Also, while the correlation length of the aperture field increases in both parallel and perpendicular directions, significant anisotropy is developed in both samples with the progression of shearing. The results on Westerly granite provide a direct indication that fracture aperture remains largely unaffected until 1 mm of displacement is achieved, which is important when estimating permeability enhancement due to natural and induced shear displacement in faults.

Fabrication and characterization of bismuth-doped germano-silicate and phospho-silicate fibers for VIS/NIR applications

We report a reproducible fabrication process ensuring repeatable absorption and emission properties of bismuth (Bi) doped silica-glass optical fibers (BDFs) with single-mode operation above ∼800 nm. BDFs were fabricated through a modified chemical vapor deposition process in-line with the solution-doping technique. Lithium-germanosilicate, yttrium-germanosilicate, and yttrium-phosphosilicate glasses were used as hosts for Bi. Bi and other dopant concentrations were measured by EPMA. ∼0.07wt% of Bi content is obtained with a transparent core. The absorptive and emissive properties of BDFs in the VIS-NIR range (targeted onto 600-900 nm) were studied thoroughly. This study is oriented to the development of VIS/NIR lasers and amplifiers, using BDFs of this type.

Особенности дефектно-примесного состава кристаллов алмаза с пирамидами роста &lt;100&gt; из россыпей Красновишерского района, Урал

The internal structure of cuboid diamonds from contemporary alluvial placers of the Krasnovishersky district at the Urals was investigated with analyzing their spectroscopic characteristics. Crystals were divided into four groups by their anatomy and spectroscopic features: cuboids of the II variety in the Yu. L. Orlov classification; cuboids with transparent core and outer part saturated with inclusions; crystals with simultaneous growth of and pyramids, and crystals with their consecutive growth. The local photoluminescence investigations have been carried out for all different growth zones and pyramids. There was revealed localization of luminescence bands 926 and 933 nm to growth pyramids and . In all studied crystals, the last stage of growth was the regenerative formation of {111} face steps together with square pits forming on the surface. Some cuboids with C centres have specific luminescence systems, such as 575, 635.1, 636.8 nm, broad band with maximum at 700 nm, and intense lines at 800, 820.5, 840, 860, 869 nm. Different thermal history of mixed-habit diamonds was shown. It is noted that the cuboid diamonds from different regions of the world have the similar internal structure and spectroscopic features.

Sediment sampling with a core sampler equipped with aluminum tubes and an onboard processing protocol to avoid plastic contamination

Microplastics are abundant even on the deep-sea floor far from land and the ocean surface where human activities take place. To obtain samples of microplastics from the deep-sea floor, a research vessel and suitable sampling equipment, such as a multiple corer, a box corer, or a push corer manipulated by a remotely operated (ROV) or human occupied vehicle (HOV) are needed. Most such corers use sampling tubes made of plastic, such as polycarbonate, acrylic, or polyvinyl chloride. These plastic tubes are easily scratched by sediment particles, in particular during collection of coarse sandy sediments, and, consequently, the samples may become contaminated with plastic from the tube. Here, we report on the use of aluminum tubes with both a multiple corer and a push corer to prevent such plastic contamination. When compared with plastic tubes, aluminum tubes have the disadvantages of heavier weight and non-transparency. We suggest ways to overcome these problems, and we also present an onboard processing protocol to prevent plastic contamination during sediment core sampling when plastic tubes are used.•Use of a sediment corer with aluminum tubes reduces the risk of plastic contamination in the sediment samples•The proposed method allows undisturbed sediment cores to be retrieved with comparable efficiency to conventional transparent core tubes

A core–shell MnO2@Au nanofiber network as a high-performance flexible transparent supercapacitor electrode

A highly transparent core–shell MnO2@AuNF network electrode is fabricated for a flexible portable energy storage device

Monte Carlo simulation of gamma-ray distribution around spent nuclear fuel assembly using a fiber-optic Cerenkov radiation sensor

A fiber-optic Cerenkov radiation sensor (FOCRS), which utilizes transparent core of the optical fiber as a sensing material of gamma ray, has been evaluated a feasibility in application of determining radiation release characteristic of spent nuclear fuel by Monte Carlo simulation with GEANT4 simulation toolkit. A simulation model with Westinghouse type 17 × 17 fuel assembly and the FOCRS were constructed with GEANT4 and the nuclide composition of spent nuclear fuel was evaluated with ORIGEN-ARP. The simulation results exhibit that the FOCRS could describe the gamma ray distribution emitted from spent nuclear fuel assembly. The FORCS, therefore, can be used to evaluate gamma ray distribution at extremely radiation environment around the spent nuclear fuel assembly.

A series of nanoparticles with phase-separated structures by 1,1-diphenylethene controlled one-step soap-free emulsion copolymerization and their application in drug release

A facile one-step approach to synthesize various phase-separated porous, raspberry-like, flower-like, core–shell and anomalous nanoparticles and nanocapsules via 1,1-diphenylethene (DPE) controlled soap-free emulsion copolymerization of styrene (S) with glycidyl methacrylate (GMA), or acrylic acid (AA) is reported. By regulating the mass ratio of S/GMA, transparent polymer solution, porous and anomalous P(S-GMA) particles could be produced. The P(S-GMA) particles turn from flower-like to raspberry-like and then to anomalous structures with smooth surface as the increase of divinylbenzene (DVB) crosslinker. Transparent polymer solution, nanocapsules and core–shell P(S-AA) particles could be obtained by altering the mole ratio of S/AA; anomalous and raspberry-like P(S-AA) particles are produced by adding DVB. The unpolymerized S resulted from the low monomer conversion in the presence of DPE aggregates to form nano-sized droplets, and migrates towards the external surfaces of the GMA-enriched P(S-GMA) particles and the internal bulk of the AA-enriched P(S-AA) particles. The nano-sized droplets function as in situ porogen, porous P(S-GMA) particles and P(S-AA) nanocapsules are produced when the porogen is removed. This novel, facile, one-step method with excellent controllability and reproducibility will inspire new strategies for creating hierarchical phase-separated polymeric particles with various structures by simply altering the species and ratio of comonomers. The drug loading and release experiments on the porous particles and nanocapsules demonstrate that the release of doxorubicin hydrochloride is very slow in weakly basic environment and quick in weakly acidic environment, which enables the porous particles and nanocapsules with promising potential in drug delivery applications.

Saturation and degradation of the photoluminescent response of pyrromethene imbedded in a polymeric matrix; Comparison between films and optical fiber geometries

In this work, poly(methyl methacrylate) (PMMA) thin films and a polymer optical fiber doped with pyrromethene (PM-567) were fabricated and characterized. The obtained films were uniform and homogeneous in its central zone and no aggregation of dye molecules were observed. UV–vis absorption, photoluminescence spectra, lifetime and photodegradation were measured for the fabricated films. Peak intensity and position of the photoluminescence spectra were dependent on the pyrromethene concentration. A resonant energy transfer mechanism is proposed as the main process associated with this behavior. Photodegradation results were well fitted by a gamma probability density function. While thin films were highly degraded under 405nm excitation, the studied optical fiber displayed a much more stable behavior, presumably related with its construction design based on a transparent core and a thin PM-567 doped cladding.

Analysis of Partial Crystallization in Yb3+ Doped Aluminophosphosilicate Fiber Preforms Prepared with Organic Chelate Precursor Doping Technique

Yb3+ doped aluminophosphosilicate fiber preforms have been prepared by modified chemical vapor deposition (MCVD) with organic chelate precursor doping technique (OCD). It was found that the flow ratio of Yb(thd)3/POCl3 had an important influence on partial crystallization in the preform cores. The wholly transparent core was obtained when the flow ratio of Yb(thd)3/POCl3 ranged in 0.71:1–0.82:1. Crystallization occurred during etching process when the Yb(thd)3/POCl3 flow ratio was over 0.83:1, corresponding to a doping ratio of Yb2O3/P2O5 larger than 1.01:1, as characterized by electron probe microanalysis (EPMA). X-ray photoelectric spectroscopy (XPS) analysis indicated exsistence of P in the quasi-metaphosphate [PO4] bond structures in the crystallized area. Raman spectra displayed characteristic peaks of silica glasses except 1330 cm−1 Raman peaks, which can be assigned to P=O bond due to the presence of quasi-metaphosphate [PO4] units. When the content ratio of Yb2O3/P2O5 exceeded 1.01:1, Al was depleted and P was enriched, and the Yb3+ ions was mainly connected with the quasi-metaphosphate [PO4] units, which weakened the role of P and Al preventing Yb3+ ions clustering. As a result, crystallization occurred. And this schematic glass structural model was proposed for the partially crystallized preform core.

Exploiting Dual Homing in Access Networks to Improve Resiliency in Core Networks

We propose a network architecture consisting of long-reach passive optical network-based access and a transparent optical core network. The end users are connected to the remote node or the local exchange (LE) through an optical distribution network, and the remote node is connected by disjoint feeder fiber links to central offices located in two distinct metro/core (MC) nodes. This method of connecting a single remote node to two geographically separate MC nodes for dedicated protection in case of feeder fiber failure is referred to as dual homing. In this work, we explore the benefits of dual homing in the access in simultaneously providing better resilience and load balancing in the core network considering connections between LEs. While looking into the benefits of dual homing in terms of network resiliency, we also explore whether the path redundancies added by dual homing play a role in providing efficient distribution of load across the core network and thereby reduce the cost of provisioning capacity in terms of number of lightpaths, transponders, etc. Dual homing at both the source and destination LEs offers more options for paths between LEs through the core network. Our results show that dual-homed access proves to be advantageous over single-homed access in terms of enhancing both core network resiliency and facilitating better load balancing.