Pipeline Placement Research Articles

Microsurgical Management of Internal Carotid Artery Bifurcation Aneurysm After Failure of Endovascular Coiling and Flow Diversion: 2-Dimensional Operative Video.

We describe the case of a 51-year-old woman who underwent craniotomy and surgical clipping of a large internal carotid bifurcation aneurysm that was refractory to treatment with 2 rounds of endovascular coiling and internal carotid artery (ICA) to middle cerebral artery pipeline placement. The patient initially presented in 2004 with a 3-week history of sudden-onset headache with associated nausea. Computed tomography and lumbar puncture on presentation in 2004 were negative for subarachnoid hemorrhage. Digital subtraction angiography, however, demonstrated a large left ICA bifurcation aneurysm. The decision was made to proceed with endovascular coiling of the aneurysm. Six-month and 1-year follow-up imaging showed incomplete resolution of the aneurysm, and retreatment coiling was completed in 2005. After recoiling in 2005, the patient was lost to follow-up. During this period, she underwent pipeline placement from the ICA to the middle cerebral artery across the A1 segment at a different institution. Two years after flow diversion, the patient was referred back to our institution with further worsening of the aneurysm. Our surgical team opted for craniotomy and surgical clipping given the limited management options that this extremely complex case now presented. The patient consented to the procedure. Postoperative imaging demonstrated marked improvement in aneurysm severity. Although the current neurosurgical trend favors endovascular treatment over craniotomy, this case shows the vital importance of craniotomy and aneurysm clipping in the treatment of select patients. We also provide high-quality operative video of aneurysm clipping.1-7.

565 Delayed Rupture Risk of Persistently Filling Saccular ICA Aneurysms Following Flow Diversion with the Pipeline Embolization Device

INTRODUCTION: Flow diversion of intracranial aneurysms results in high occlusion rates. However, 10-20% of aneurysms remain persistently filling on one year angiography. Often, these are retreated, but risks and benefits of retreatment are not well established. Calculating benefit requires a better understanding of rupture risk of persistently filling flow diverted aneurysms, which is not sufficiently established. METHODS: Our single institution database of 1000 flow diversion cases was queried for persistently filling saccular aneurysms of the clinoidal, ophthalmic, and communicating segments of the internal carotid artery treated with Pipeline Embolization Device or Pipeline Flex. Persistent filling was defined as continued contrast flow into the aneurysm on catheter angiogram one year after treatment. The clinical record was queried for occurrences of retreatment and delayed subarachnoid hemorrhage. Only cases with at least two years of follow up were included. RESULTS: Ninety-four persistent aneurysms were identified. The average size was 6 mm. The branch vessel originated separately from the aneurysm in 55% of cases, from the body of the aneurysm in 10.6% of cases, and from the neck in 34% of cases. Eighteen percent of aneurysms demonstrated >95% filling at one year and 61% were filling 5-95% of their original size. Average follow up time was 4.9 years, including 23 cases with >5 years follow up. No retreatment was undertaken in 91.5% of aneurysms. There were no cases of delayed subarachnoid hemorrhage. CONCLUSIONS: In our cohort of saccular ICA aneurysms treated with Pipeline flow diversion that demonstrated persistent aneurysm filling at one year, there were no instances of delayed rupture during the study period. This data suggests that observation may be appropriate for continued aneurysm filling at least in the first several years following Pipeline placement.

Fragility analysis of a pipeline under slope failure-induced displacements occurring parallel to its axis

Providing urbanized centers with hydrocarbon supplies from remote production centers, transmission pipelines run for thousands of kilometers, inevitably traversing mountainous and rugged terrain, where slope failure is the dominant source of risk. Strategies to manage these risks heavily depend on the quantification of uncertainty. To this end, this paper presents a fragility analysis framework to quantify the effect of uncertainties, that makes use of a Random Forests algorithm as a surrogate model to thoroughly explore the uncertain parameter space. The Random Forests algorithm is trained and tested against a small, yet statistically significant sample of Sliding Slope-Pipeline Interaction (SSPI) cases that are meticulously analyzed using a rigorous 3D continuum-based numerical methodology. The fragility analysis framework is applied to a 36 in. pipeline descending a slope, with possible soil movement occurring parallel to its axis. Uncertainty stems from the variability in soil properties (friction angle, cohesion and density), in pipe steel material properties (yield strength), in the magnitude of operational loads (pressure and temperature) and in the pipeline placement depth around their expected values, as well as from the lack of knowledge of the geological conditions (the depth of the eroded surficial layer) that ultimately control the shape of the failure surface. Τhe significance of each uncertain variable on the response of the pipeline is investigated, concluding that the depth and shape of the failure surface (correlated with the depth of the surficial layer) is be the most influential parameter, governing the pipeline performance and ultimately the safety thresholds.

Design Space Exploration for High-Speed Implementation of the MISTY1 Block Cipher

This paper proposes 2 × unrolled high-speed architectures of the MISTY1 block cipher for wireless applications including sensor networks and image encryption. Design space exploration is carried out for 8-round MISTY1 utilizing dual-edge trigger (DET) and single-edge trigger (SET) pipelines to analyze the tradeoff w.r.t. speed/area. The design is primarily based on the optimized implementation of lookup tables (LUTs) for MISTY1 and its core transformation functions. The LUTs are designed by logically formulating S9/S7 s-boxes and FI and {FO + 32-bit XOR} functions with the fine placement of pipelines. Highly efficient and high-speed MISTY1 architectures are thus obtained and implemented on the field-programmable gate array (FPGA), Virtex-7, XC7VX690T. The high-speed/very high-speed MISTY1 architectures acquire throughput values of 25.2/43 Gbps covering an area of 1331/1509 CLB slices, respectively. The proposed MISTY1 architecture outperforms all previous MISTY1 implementations indicating high speed with low area achieving high efficiency value. The proposed architecture had higher efficiency values than the existing AES and Camellia architectures. This signifies the optimizations made for proposed high-speed MISTY1 architectures.

Application of rooftop solar panels with coolant natural circulation

AbstractIn line with the energy development strategy of Europe, it is necessary to implement energy efficient buildings, in which the external enclosures are converters of solar energy to thermal. Therefore, the purpose of the publication was the scientific substantiation and development of the solar heating system with the use of rooftop solar panels. Graphical and analytical dependences of the coefficient of thermal efficiency of the solar panel in heat supply system from the angles of solar radiation incoming and the density of the radiation flux were obtained. Analysis of the results showed that the coefficient of thermal efficiency of the solar panel without transparent coating with the placement of pipelines of the circulation circuit of the coolant over the heat absorber increases by 50%.

Managing Chains of Application Functions Over Multi-Technology Edge Networks

Next-generation networks are expected to provide higher data rates and ultra-low latency in support of demanding applications, such as virtual and augmented reality, robots and drones, etc. To meet these stringent requirements of applications, edge computing constitutes a central piece of the solution architecture wherein functional components of an application can be deployed over the edge network to reduce bandwidth demand over the core network while providing ultra-low latency communication to users. In this article, we provide solutions to resource orchestration and management for applications over a virtualized client-edge-server infrastructure. We investigate the problem of optimal placement of pipelines of application functions (virtual service chains) and the steering of traffic through them, over a multi-technology edge network model consisting of both wired and wireless millimeter-wave (mmWave) links. This problem is NP-hard. We provide a comprehensive “microscopic” binary integer program to model the system, along with a heuristic that is one order of magnitude faster than optimally solving the problem. Extensive evaluations demonstrate the benefits of orchestrating virtual service chains (by distributing them over the edge network) compared to a baseline “middlebox” approach in terms of overall admissible virtual capacity. Moreover, we observe significant gains when deploying a small number of mmWave links that complement the Wire physical infrastructure in high node density networks.

Structure optimization and optimal pipeline placement in programmable data plane virtualization scheme

Virtualization of the programmable data plane allows multiple virtual pipelines to be placed on the same physical programmable device, enabling more flexible network function composition, debugging, etc. Existing proposals like HyPer4 and HyperVDP realize virtualization with a hypervisor-like program to emulate customers' programs, which becomes the mainstream of the current methods. Despite the progress achieved, their designs still have problems from inefficient structure to waste of resources. At the same time, they do not consider how to reasonably place the pipeline of different customers on the hypervisor which may cause unnecessary recirculations. So, in this paper, we present HyperSwitch, an efficient data plane hypervisor with several new techniques to optimize its structure design and reduce the resource consumption. We also model the multiple pipeline placement problem into an integer linear programming problem so that it can have the optimal solution. Compared to existing work, HyperSwitch acquires a decreasing delay by 26.3\% on average and avoids almost all happenings of recirculation.

Modular approach for optimal pipeline layout

Oil and gas production systems are getting deeper, more complex, and far away offshore where energy companies are targeting further resources. These complexities are transforming the problem of field layout design optimization into a much more pressing need. Considering the various pipeline design and layout constraints and associated investment costs, planning and development of production gathering and transmission pipeline networks for oil and gas fields is gaining further importance in field development planning. The optimization of transmission and gathering pipeline networks is conducted to accommodate the encountered topological complexities and significantly reduce total investment cost for the corresponding fields. Although many optimization schemes are developed and widely available in literature, these methods are either prohibitively slow with exhaustive search required, or they don't account for the various topological complexities typically encountered in real scenarios. Thus, the deficiency associated to these optimization schemes becomes drastically more limiting in the case of a concept-select phase of field development planning where many scenarios need to be assessed in a relatively short timeframe.In this study, the optimal shortest path A* algorithm is introduced to the field of pipeline placement optimization. A* is successfully used in other applications such as unmanned aerial vehicle (UAV) and robots motion planning. A benchmark comparison is presented with the Dijkstra algorithm; another algorithm that assures optimal shortest path solution that was recently introduced into this field. This comparison is performed on a varied set of pipeline layout scenarios accounting for different topological complexities and dynamic conditions. The conducted tests show the superiority of the A* algorithm in terms of accounting for the application heuristics and assuring an optimal and efficient solution.

Акустическая эффективность экранов для снижения шума от газораспределительных пунктов и их газопроводов

The aim of this study is to determine the capabilities of acoustic barriers to reduce noise from gas distribution stations (GDS) and gas pipelines outgoing from them. The specific feature relating to the calculation of noise from the GDS building is that the noise emitted from the GDS building at the gas pipelines exit place can be taken as the main source of noise. The uniqueness of the calculation of noise from gas pipelines is that the noise is emitted nonuniformly over the length, and that the gas pipelines go at different heights above the ground level. Computer-aided calculations are carried out for estimating the acoustic efficiency of barriers having different heights in terms of reducing noise from the GDS building and from the gas pipelines going from the GDS building at different heights from the ground at a fixed barrier height. Three-dimensional graphs for determining the attenuation as a function of the barrier height and distance from the barrier to the calculated point at a fixed distance from the GDS building to the barrier are plotted. The calculation results show that it is not possible to fulfill the permissible sanitary norms for industrial areas by using an acoustic barrier from the noise of a large GDS building with a sound level of 110 dBA. It is shown that the maximum attenuation of noise from the GDS building will be at a barrier height of not less than 7.4 m with the calculation point located at a distance of 300 m. The calculation results have shown that the larger the gas pipeline placement height, the less efficient the noise attenuation by the barrier is. If the height from the gas pipeline to the barrier top edge is less than 2.5 m, the use of the barrier is not recommended. It is shown that, owing to the reduction of sound along the gas pipeline, the application of barriers makes it possible to comply with the permissible sanitary norms for production areas.

Pipeline in thermal insulation of outside wall

Abstract The paper deals with the pipeline management in the thermal insulation of the perimeter wall. Such a pipeline reduces the thickness of the thermal insulation of the building envelope, deteriorates the thermal insulation properties of the wall and creates a linear thermal bridge. The paper deals with alternatives of gas pipeline placement in the thermal insulation of the perimeter wall. The result is a comparison of alternatives of detail solutions with graphical representation of temperature and humidity of structures, description of critical areas and possibilities of application in practice.

Patterns, Predictors, and Outcomes of Postprocedure Delayed Hemorrhage Following Flow Diversion for Intracranial Aneurysm Treatment

To evaluate patterns, predictors, and outcomes of postprocedure delayed hemorrhage (PPDH) following flow diversion therapy for intracranial aneurysm treatment. From 2012 to 2016, 50 patients with 52 aneurysms were treated with the Pipeline embolization device. Device placement was performed as a standalone therapy or with adjunctive coil embolization. Patients underwent dual antiplatelet therapy for 6 months after treatment. Medical comorbidities; aneurysm traits; and treatment factors, including platelet function testing, were studied. Statistical analysis was performed using cross-tabulation. Six PPDHs (12%) occurred 2-16 days (mean 6.8 days) after Pipeline placement, manifesting as 1 of 2 distinct patterns: convexity subarachnoid hemorrhage (cSAH) (n= 4) or lobar intraparenchymal hemorrhage (IPH) (n= 2). All PPDHs occurred ipsilateral to the device; 1 IPH occurred ipsilateral but in a different arterial territory. PPDH occurred in both treated anterior communicating artery aneurysms. Cases of PPDH demonstrated on average lower P2Y12 reaction unit values at the time of treatment. Platelet function testing at the time of hemorrhage was consistently hypertherapeutic. Patients with cSAH had only minimal worsening of modified Rankin Scale score at the time of discharge, whereas the 2 patients with IPH experienced significant deterioration. PPDH is a poorly understood complication following flow diversion therapy that can result in significant morbidity. In our experience, nonaneurysmal cSAH does not result in poor clinical outcomes, whereas IPH leads to long-term deficits or death. As previously suggested, there appears to be a correlation between low P2Y12 reaction unit values and PPDH.

Modeling of energy efficient solutions regarding the heating system and the facade heat insulation in the implementation of thermomodernization

We substantiated design and construction-technological solutions for increasing the energy efficiency of thermomodernizable buildings and structures based on the conducted calculation-and-experimental and numerical studies. We investigated effective structural parameters and material of examined elements of a thermomodernization system of residential buildings and structures, which started their operation before the 90-ies of the last century. We proposed a number of innovative design and construction-technological solutions for the thermomodernization of residential buildings and structures that provide simultaneous modernization of a system of central water heating and facade insulation. Distribution of the temperature field inside a building structure, temperature on the surface of a facade thermal insulation at variation of its thickness by different forms of making of new indents, where new pipelines of a two-pipe system of a central water heating are located, were investigated. In particular, we established that such placement of pipelines makes it possible to reduce heat losses from these pipelines significantly (by up to 74 %) comparing with the placement in a layer of facade insulation at the side of a wall. We investigated the dependence of the cooling time of a heat-transfer agent temperature to 0 o C at the complete cessation of its flow through pipelines on the thickness of a thermal insulation. We determined experimentally the minimum thickness of a facade insulation layer, which is 50 mm, for the studied temperature mode and operating conditions, as well as for characteristics of the materials used, the geometry of pipelines and the facade insulation. We obtained the optimum thickness of a facade insulation layer, which is 100 mm. It provides up to a 100 % freeze protection of pipelines even when a heat-transfer agent movement stops for more than 24 hours. We established that an increase in the thickness of a facade heat insulation contributes to the additional drainage of a building structure, which leads to improvement of thermal characteristics of the thermomodernized building. The study showed that the developed innovative design and construction-technological solutions lead to a significant reduction in the energy consumption of existing buildings and structures of the housing stock, which has been in operation for longer than 30 years, and contribute to maintaining comfortable living conditions.

Use of thromboelastography to tailor dual-antiplatelet therapy in patients undergoing treatment of intracranial aneurysms with the Pipeline embolization device

BackgroundPlatelet function testing is controversial and not well studied in patients with neurovascular disease.ObjectiveTo evaluate the performance of thromboelastography (TEG) as a platelet function test in neurovascular patients treated with...

Method of calculating vibrations in a pipeline with damping supports made of MR material

A method of calculating vibrations in a pipeline of an arbitrary shape with damping supports made of MR material with the help of the finite element method ANSYS software is developed. The method takes into account the non-linearity of MR material, it makes it possible to determine the amplitudes of pipeline vibration and the stress in the pipeline. The calculation results are confirmed by an experiment with the ARAMIS measurement system. The method can be used for placement of pipelines.

Placing pipeline stages on a Grid: Single path and multipath pipeline execution

In a Grid computing environment, several applications such as scientific data analysis and visualization are naturally computation and communication intensive. These applications can be decomposed into a sequence of pipeline stages which can be placed on different Grid nodes for concurrent execution. Due to the aggregation of the computation and communication costs involved, finding the way to place such pipeline stages on a Grid in order to achieve the maximum application throughput becomes a challenging problem. This paper proposes a solution that considers both the pipeline placement and the data movement between stages. Specifically, we try to minimize the computation cost of the pipeline stages while preventing the communication overhead between successive stages from dominating the entire processing time. Our proposed solution consists of two novel methods. The first method is single path pipeline execution, which exploits only temporal parallelism, and the second method is multipath pipeline execution, which considers both temporal and spatial parallelism inherent in any pipeline applications. We evaluate our work in a simulated environment and also conduct a set of experiments in a real Grid computing system. When compared with the results from several traditional placement methods, our proposed methods give the highest throughput.

Ground penetrating radar surveys of peatlands for oilfield pipelines in Canada

Placement of buried pipelines in thick peat deposits is difficult because of the low bearing strength and high water content of the material for support of heavy construction equipment. Previously, ground penetrating radar (GPR) has been used to assess thickness and volume of peat as a fuel resource and horticultural material in Scandinavia and Canada. To our knowledge, GPR has not been applied to the site assessment and placement of pipelines crossing peatlands. Field experiments were conducted in the Mitsue oilfield operated by Chevron Canada Resources Ltd., located immediately southeast of Lesser Slave Lake in north-central Alberta Province, Canada. Surficial deposits consist of Holocene, linear, sandy beach ridges separated by peatlands underlain by sand. Several GPR surveys assessed the thickness of the peat along two oil pipeline right-of-ways. Results show the peat-sand contact as irregular and undulating, ranging from 0 to 3.7 m deep. Each survey, 460 and 550 m long, was completed in two hours. Such results from 1 m station spacings (sampling interval) can considerably reduce the uncertainties in planning and placement of oil, gas, and water pipelines crossing peatlands. Results indicate that thickness variations of peat can be detected more effectively in terms of quality of results, lower cost, and less time with GPR than with a peat probe or by coring.

Offshore Oil in the Alaskan Arctic

Oil and gas deposits in the Alaskan Arctic are estimated to contain up to 40 percent of the remaining undiscovered crude oil and oil-equivalent nature gas within U.S. jurisdiction. Most (65 to 70 percent) of these estimated reserves are believed to occur offshore beneath the shallow, ice-covered seas, of the Alaskan continental shelf. Offshore recovery operations for such areas are far from routine, with the primary problems associated with the presence of ice. Some problems that must be resolved if efficient, cost-effective, environmentally safe, year-round offshore production is to be achieved include the accurate estimation of ice forces on offshore structures, the proper placement of pipelines beneath ice-produced gouges in the sea floor, and the cleanup of oil spills in pack ice areas.

Predicting Frost Depth; Protecting Underground Pipelines

To aid in protecting buried pipelines in a climate where winter temperatures can fall as low as ‐30°C, a study was undertaken to find better formulas for predicting frost depth so as to more reliably select optimum pipeline placement depths.