Feasibility Study of S-Lay Installation for Deepwater SCRs and Pipelines

Author(s):  
Jing Hou ◽  
Chenteh Alan Yu ◽  
Yongming Cheng ◽  
Gurudutt Bangalore ◽  
Hao Song

Abstract The J-lay and S-lay are two common methods for SCR and pipeline installations. When using the S-lay installation method, onboard welded pipe joints leave the vessel horizontally and are guided to the seabed over a stinger structure. The pipe is lowered using tensioners. With the advantage of high production rate, Slay can be a cost-effective solution for deepwater riser and pipeline installation. Based on HYSY201 installation vessel, this paper investigates the feasibility of S-lay installation for deepwater SCRs and pipelines to be used in South China Sea. It first introduces the SCRs and pipelines to be used for a deep draft semi-submersible for the Lingshui 17-2 project. It then presents the S-lay installation vessel HYSY201 and S-lay configuration. The hydrodynamic motion analysis for a Response Amplitude Operator (RAO) was computered for HYSY201 in different environmental headings. With the site-specific metocean design basis, this paper presents an installation procedure, analysis methodology, and acceptance criteria. The study covers different sizes of SCRs and pipelines to investigate the feasibility of S-lay installation. The study starts from the static installation analysis of SCRs and pipelines and includes different installation steps. The acceptance criteria are examined for the pipes at over bend and sag bend regions. The support reactions load on the stinger structure are reported at each step. The dynamic analysis is selectively performed to evaluate Dynamic Amplification Factors (DAFs) of support reaction loads especially for roller box supports on the stinger structure. The sensitivity of DAFs to wave parameters such as wave height and peak period is analyzed as well. The extreme support reaction loads are computed for evaluating the strength performance of the stinger structure. The feasibility of S-lay installation for deepwater SCRs and pipelines is determined by the global performance of SCRs and pipelines, installation vessel hold back tension and A&R winch load capacity, and performance of the stinger structure. Based on the study work, this paper finds the feasibility of S-lay installation of deepwater SCRs and pipelines for Lingshui 17-2 project using the installation vessel of HYSY201.

Author(s):  
Yan Pan ◽  
Shining Li ◽  
Qianwu Chen ◽  
Nan Zhang ◽  
Tao Cheng ◽  
...  

Stimulated by the dramatical service demand in the logistics industry, logistics trucks employed in last-mile parcel delivery bring critical public concerns, such as heavy cost burden, traffic congestion and air pollution. Unmanned Aerial Vehicles (UAVs) are a promising alternative tool in last-mile delivery, which is however limited by insufficient flight range and load capacity. This paper presents an innovative energy-limited logistics UAV schedule approach using crowdsourced buses. Specifically, when one UAV delivers a parcel, it first lands on a crowdsourced social bus to parcel destination, gets recharged by the wireless recharger deployed on the bus, and then flies from the bus to the parcel destination. This novel approach not only increases the delivery range and load capacity of battery-limited UAVs, but is also much more cost-effective and environment-friendly than traditional methods. New challenges therefore emerge as the buses with spatiotemporal mobility become the bottleneck during delivery. By landing on buses, an Energy-Neutral Flight Principle and a delivery scheduling algorithm are proposed for the UAVs. Using the Energy-Neutral Flight Principle, each UAV can plan a flying path without depleting energy given buses with uncertain velocities. Besides, the delivery scheduling algorithm optimizes the delivery time and number of delivered parcels given warehouse location, logistics UAVs, parcel locations and buses. Comprehensive evaluations using a large-scale bus dataset demonstrate the superiority of the innovative logistics UAV schedule approach.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1437
Author(s):  
Jing Yi Ong ◽  
Andrew Pike ◽  
Ling Ling Tan

The presence of mycotoxins in foodstuffs and feedstuffs is a serious concern for human health. The detection of mycotoxins is therefore necessary as a preventive action to avoid the harmful contamination of foodstuffs and animal feed. In comparison with the considerable expense of treating contaminated foodstuffs, early detection is a cost-effective way to ensure food safety. The high affinity of bio-recognition molecules to mycotoxins has led to the development of affinity columns for sample pre-treatment and the development of biosensors for the quantitative analysis of mycotoxins. Aptamers are a very attractive class of biological receptors that are currently in great demand for the development of new biosensors. In this review, the improvement in the materials and methodology, and the working principles and performance of both conventional and recently developed methods are discussed. The key features and applications of the fundamental recognition elements, such as antibodies and aptamers are addressed. Recent advances in aptasensors that are based on different electrochemical (EC) transducers are reviewed in detail, especially from the perspective of the diagnostic mechanism; in addition, a brief introduction of some commercially available mycotoxin detection kits is provided.


Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1342
Author(s):  
Borja Nogales ◽  
Miguel Silva ◽  
Ivan Vidal ◽  
Miguel Luís ◽  
Francisco Valera ◽  
...  

5G communications have become an enabler for the creation of new and more complex networking scenarios, bringing together different vertical ecosystems. Such behavior has been fostered by the network function virtualization (NFV) concept, where the orchestration and virtualization capabilities allow the possibility of dynamically supplying network resources according to its needs. Nevertheless, the integration and performance of heterogeneous network environments, each one supported by a different provider, and with specific characteristics and requirements, in a single NFV framework is not straightforward. In this work we propose an NFV-based framework capable of supporting the flexible, cost-effective deployment of vertical services, through the integration of two distinguished mobile environments and their networks: small sized unmanned aerial vehicles (SUAVs), supporting a flying ad hoc network (FANET) and vehicles, promoting a vehicular ad hoc network (VANET). In this context, a use case involving the public safety vertical will be used as an illustrative example to showcase the potential of this framework. This work also includes the technical implementation details of the framework proposed, allowing to analyse and discuss the delays on the network services deployment process. The results show that the deployment times can be significantly reduced through a distributed VNF configuration function based on the publish–subscribe model.


Author(s):  
Kala Meah ◽  
Steven Fletcher ◽  
Yu Wan ◽  
Sadrul Ula

Many parts of the western US is rural in nature and consequently do not have electrical distribution lines in many parts of farms and ranches. Distribution line extension costs can run from $15,000 to $25,000 per mile, thereby making availability of electricity to small water pumping projects economically unattractive. Solar photo-voltaic (PV) powered water pumping is more cost effective in these small scale applications. Many western states including Wyoming are passing through fifth year of drought with the consequent shortages of water for many applications. Wyoming State Climatologist is predicting a possible 5–10 years of drought. Drought impacts the surface water right away, while it takes much longer to impact the underground aquifers. To mitigate the effect on the livestock and wildlife, Wyoming Governor Dave Freudenthal initiated a solar water pumping initiative in cooperation with the University of Wyoming, County Conservation Districts, Rural Electric Cooperatives, and ranching organizations. Solar water pumping has several advantages over traditional systems; for example, diesel or propane engines require not only expensive fuels, they also create noise and air pollution in many remote pristine areas. Solar systems are environment friendly, low maintenance and have no fuel cost. In this paper the design, installation and performance monitoring of the solar system for small scale remote water pumping will be presented.


Author(s):  
Will Judge ◽  
Georges Kipouros

The production of aluminum alloys through powder metallurgy (PM) processes allows for the manufacture of net- or near-net-shape components in a cost-effective and sustainable manner. The high reactivity of aluminum metal, however, complicates PM processing, and special attention must be given to certain steps during production, particularly sintering. PM processing conditions strongly affect the structure and porosity of aluminum PM alloys, which ultimately determine their material properties and performance. In this article, the fundamental aspects of the commercial production of aluminum PM alloys are presented, along with the effects of production conditions on the structure and porosity of aluminum PM alloys. The properties and performance of aluminum PM alloys are then analyzed and interpreted with respect to their structure and porosity.


2021 ◽  
Vol 10 (19) ◽  
pp. 4353
Author(s):  
Jonas Pfeifle ◽  
David Hasler ◽  
Nicola Maffiuletti

Deficits in maximal and explosive knee extensor strength, which are usually assessed with unilateral tasks, are substantial in patients with knee osteoarthritis (KOA). The aim of this study was to investigate the clinical relevance of unilateral vs. bilateral tasks for assessing knee extensor strength in patients with KOA. This was achieved primarily by comparing unilateral and bilateral inter-limb strength asymmetries and secondarily by examining the relationship between unilaterally and bilaterally measured strength, and performance-based and self-reported function. Twenty-four patients with unilateral KOA (mean age: 65 ± 7 years) performed isometric gradual and explosive maximal voluntary contractions to assess, respectively their maximal and explosive strength. Performance-based and self-reported function were also evaluated with standard functional tests and questionnaires, respectively. Inter-limb asymmetries of maximal and explosive strength did not differ significantly between unilateral (mean asymmetry: 26 ± 15%) and bilateral tasks (22 ± 21%). In the same way, the relationships between knee extensor strength—measured either unilaterally or bilaterally—and performance-based or self-reported function were not influenced by the type of task. In conclusion, it does not seem to make a difference in terms of clinical relevance whether maximal and explosive knee extensor strength are evaluated with unilateral or bilateral tasks in KOA patients.


Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Olli S Mattila ◽  
Heini Harve ◽  
Saana Pihlasviita ◽  
Juhani Ritvonen ◽  
Gerli Sibolt ◽  
...  

Background and purpose: Blood-based biomarkers could enable early and cost-effective diagnostics for acute stroke patients in the prehospital setting to support early initiation of treatments. However, large prehospital sample sets required for biomarker discovery and validation are missing, and the feasibility of large-scale blood sampling by emergency medical services (EMS) has not been determined. We set out to establish extensive prehospital blood sampling of thrombolysis candidates in the catchment area of our comprehensive stroke center, with a 1.5 million population base. Methods: EMS personnel were trained to collect prehospital blood samples using a cannula-adapter technique. Time delays, sample quality and performance bottlenecks were investigated between May 20, 2013 and May 19, 2014. Results: Prehospital blood sampling and study recruitment were successfully performed in 430 thrombolysis candidates, of which 55.3% were admitted outside office hours. The median (interquartile range) emergency call to prehospital sample time was 33 minutes (25-41), and the median time from reported symptom onset or wake-up to prehospital sample was 53 minutes (38-85; n=394). Prehospital sampling was performed 31 minutes (25-42) earlier than admission blood sampling, and 37 minutes (30-47) earlier than admission neuroimaging. Quality control data from 25 participating EMS units indicated a 4-minute increase in median transport time (from arrival on-scene to hospital door) for study patients compared to patients of the preceding year. The hemolysis rate in serum and plasma samples was 6.5% and 9.3% for EMS samples, and 0.7% and 1.6% for admission samples collected with venipuncture. Conclusions: Prehospital biomarker sampling is feasible in standard EMS units and provides a median timesaving of over 30 minutes to obtain first blood samples. Large biobanks of prehospital blood samples will facilitate development of ultra-acute stroke biomarkers.


2021 ◽  
Vol 21 (8) ◽  
pp. 4400-4405
Author(s):  
Junyeop Lee ◽  
Nam Gon Do ◽  
Dong Hyuk Jeong ◽  
Sae-Wan Kim ◽  
Maeum Han ◽  
...  

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO2). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K2Pd(SO3)2) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.


2011 ◽  
pp. 1595-1604
Author(s):  
Scott P. Schaffer ◽  
Ian Douglas

Considerable effort has been devoted recently to development of systems or platforms that manage the learning, performance, or knowledge delivered to students and employees. These systems are generically labeled learning management systems (LMS), learning and content management systems (LCMS), performance support systems, and knowledge management systems (Rockley, 2002). Organizations increasingly use content management systems to deliver content objects to employees on a just-in-time basis to support knowledge and performance requirements (Rosenberg, 1999). While systems are developed that efficiently manage learning, knowledge, or performance, it seems desirable to consider how integration of each of these areas into a single system would benefit organizations. A major challenge to developing such systems has been the degree to which they are interoperable and the components within each are reusable. Reuse of data or information for learning or performance solution development is considered the primary driving force behind the movement toward object-based architectures for such systems (Douglas & Schaffer, 2002; Schaffer & Douglas, 2004). Ideas for integrating different sources of support for individuals and making its construction more cost effective have begun to take shape. Some efforts have focused on reusable and interchangeable (between different delivery systems) content objects, such as the U.S. Department of Defense Advanced Distributed Learning initiative (http://www.adlnet. org). A big challenge in development of support is the lack of a pedagogical model that takes advantage of object-based architectures while promoting collaboration and knowledge capture and sharing. A significant move in this direction has been outlined by Collis and Strjker (2003) who view the learner as a contributor of knowledge that may be captured and stored for reuse by future learners or course designers. An expansion of this idea, focused on in this article, is the reuse of the contributions of various members of a design and development team. This includes artifacts, decisions, and rationales related to activities such as the analysis of needs, identification of metrics, and identification of causes and possible solutions to workplace problems. This approach essentially attempts to link the analysis and design processes related to initial development of solutions with the ongoing adaptation and evaluation


Sign in / Sign up

Export Citation Format

Share Document