Multiple Small Scale Research Articles

PMMA pyrolysis simulation – from micro- to real-scale

In fire spread simulations, heat transfer and pyrolysis are processes to describe the thermal degradation of solid material. In general, the necessary material parameters cannot be directly measured. They are implicitly deduced from micro- and bench-scale experiments, i.e. thermogravimetric analysis (TGA), micro-combustion (MCC) and cone calorimetry. Using a complex fire model, an inverse modelling process (IMP) is capable to find parameter sets, which are able to reproduce the experimental results. In the real-scale, however, difficulties arise predicting the fire behaviour using the deduced parameter sets. Here, we show an improved model to fit data of multiple small scale experiment types. Primarily, a gas mixture is used to model an average heat of combustion for the surrogate fuel. The pyrolysis scheme is using multiple reactions to match the mass loss (TGA), as well as the energy release (MCC). Additionally, a radiative heat flux map, based on higher resolution simulations, is used in the cone calorimeter setup. With this method, polymethylmetacrylate (PMMA) micro-scale data can be reproduced well. For the bench-scale, IMP setups are used differing in cell size and targets, which all lead to similar and good results. Yet, they show significantly different performance in the real-scale parallel panel setup.

μDFL: A Secure Microchained Decentralized Federated Learning Fabric Atop IoT Networks

Federated Learning (FL) has been recognized as a privacy-preserving machine learning (ML) technology that enables collaborative training and learning of a global ML model based on the aggregation of distributed local model updates. However, security and privacy guarantees could be compromised due to malicious participants and the centralized aggregation manner. Possessing attractive features like decentralization, immutability and auditability, Blockchain is promising to enable a tamper-proof and trust-free framework to enhance performance and security in IoT based FL systems. However, directly integrating blockchains into the large scale IoT-based FL scenarios still faces many limitations, such as high computation and storage demands, low transactions throughput, poor scalability and challenges in privacy preservation. This paper proposes <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> DFL, a novel hierarchical IoT network fabric for decentralized federated learning (DFL) atop of a lightweight blockchain called microchain. Following the hierarchical infrastructure of FL, participants in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> DFL are fragmented into multiple small scale microchains. Each microchain network relies on a hybrid Proof of Credit (PoC) block generation and Voting-based Chain Finality (VCF) consensus protocol to ensure efficiency and privacy-preservation at the network of edge. Meanwhile, microchains are federated vie a high-level inter-chain network, which adopts an efficient Byzantine Fault Tolerance (BFT) consensus protocol to achieve scalability and security. A proof-of-concept prototype is implemented, and the experimental results verify the feasibility of the proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu $ </tex-math></inline-formula> DFL solution in cross-devices FL settings with efficiency, security and privacy guarantees.

PIV measurements on flow behavior behind a mooring line with imposed top-end motion

Experimental investigation on the flow behavior of a mooring line with imposed top-end motions were performed in a water flume. The surge and heave motions were driven by a programmable electrical motor at the fairlead position. The Particle Image Velocimetry technique (PIV) was employed to capture the instantaneous flow fields around the mooring line at both the horizontal and vertical planes. Compared with the stationary mooring line, the instantaneous vorticity contours behave much more complicated for the mooring line under the imposed surge and heave motions. The coherent vortices are formed along the curvature of the catenary mooring line, oblique vortex shedding is observed with multiple small scale vortices. The vortex strength behind the mooring line under the surge motion is larger than that under the heave motion.

Source Authentication of Distribution Synchrophasors for Cybersecurity of Microgrids

This letter proposes a hybrid approach combining Self-Adaptive Mathematical Morphology (SAMM) and Time-Frequency (TF) techniques to authenticate the source information of Distribution Synchrophasors (DS) within near-range locations. The SAMM can adaptively regulate the synchrophasors variations which are representatives of local environmental characteristics. Subsequently, TF mapping is employed to extract informative signatures from the regulated synchrophasors variation. Finally, Random Forest Classification (RFC) is used to correlate the extracted signatures with the source information based on the derived TF mapping. Experiment results using DS collected at multiple small geographical scales validated the proposed methodology.

Effects of selective fishing on a small scale multi-species and multi-gear freshwater fishery in the Magdalena River Basin (Colombia)

Classical management has not been able to stop the 65% decrease in fishery production during the last 40 years in the Magdalena–Cauca River Basin. To analyze the effects of selective fishing of multiple species and small scale fisheries we addressed temporal changes at fishing level and the response of fishermen. The fishery reduced production and CPUE (catch per unit effort standardized), decreased the large sizes and growth rates of Prochilodus magdalenae and Pseudoplatystoma magdaleniatum, changed the abundance of trophic levels (decreased carnivores and increase of detritivores, omnivores), and increased exploitation rates. The fishermen have responded by implementing self-control measures, diversifying fishing gear and mesh size, including new species and sizes in the catch with a higher CPUE of small sized fish, adjusting the fishing effort to the abundance. We conclude that selective fishing has had ecological effects and fishermen have empirically self-regulated to optimize the cost–benefit ratio of their activity, developing a fishery that is more in line with ecosystemic structures. We address the balanced harvest strategy as a management alternative.

Scalar Mismatches and Underlying Factors for Underutilization of Climate Information: Perspectives From Farmers and Ranchers

Growing demand for water resources coupled with climate-driven water scarcity and variability present critical challenges to agriculture in the Western US. Despite extensive resources allocated to downscaling climate projections and advances in understanding past, current, and future climatic conditions, climate information is underutilized in decisions made by agricultural producers. Climate information providers need to understand why this information is underutilized and what would better meet the needs of producers. To better understand how agricultural producers perceive and utilize climate information, we conducted five focus groups with farmers and ranchers across Montana. Focus groups revealed that there are fundamental scalar issues (spatial and temporal) that make climate information challenging for producers to use. While climate information is typically produced at regional, national, or global spatial scales and at a seasonal and mid- to end-of-century temporal scales, producers indicated that decision-making takes place at multiple intermediate and small temporal and spatial scales. In addition, producers described other drivers of decision-making that have little to do with climate information itself, but rather aspects of source credibility, past experience, trust in information, and the politics of climate change. Through engaging directly with end-users, climate information providers can better understand the spatial and temporal scales that align with different types of agricultural producers and decisions, as well as the limitations of information provision given the complexity of the decision context. Increased engagement between climate information providers and end-users can also address the important tradeoffs that exist between scale and uncertainty.

CHEMODNERVATION FOR CERVICAL DYSTONIA: A CLINICAL REVIEW

Cervical dystonia (CD) is a focal dystonia characterized by involuntary contractions of neck muscles that result in patterned movements and abnormal postures of the head and neck that have a directional quality. CD is the most common form of dystonia presenting to the movement disorders clinic. Botulinum toxin is an effective treatment for cervical dystonia. It has become the first-line treatment for cervical dystonia with a satisfactory relief of symptoms reported in more than 80% of the cases. Multiple small and large scale studies proven that fact and provided Class-A evidence for the benefit. However, 20% of the patients discontinue treatment due to adverse effects, treatment failure and other reasons. With the proper knowledge of toxins and the anatomy of the neck, much better results can be achieved with fewer and self-limiting adverse effects as compared to other modalities. However, the expert consensus recommendations are lacking to guide clinicians for optimal use of botulinum toxin for cervical dystonias. This paper discusses the different available treatments, botulinum injection techniques and the adverse effects involved with the procedure.

Cerinichthys koelblae, gen. et sp. nov., from the Upper Jurassic of Cerin, France, and its phylogenetic setting, leading to a reassessment of the phylogenetic relationships of Halecomorphi (Actinopterygii)

ABSTRACTUnknown, well-preserved fish specimens from the Upper Jurassic Plattenkalk of Cerin, France, found in the historical collection in Muséum d'Histoire Naturelle de Lyon, France, and from the excavation site of the Collections de Géologie, Université Claude Bernard Lyon 1, France, permit description of Cerinichthys koelblae, gen. et sp. nov. This new genus differs from all other Halecomorphi in the following combination of features: 27 caudal principal rays; 51 vertical scale rows; presence of broadened basal fin segments in the posterior rays of the pectoral, pelvic, anal, and dorsal fins and the median rays of the caudal fin; complete absence of vertebral centra in adult-sized individuals and multiple small scales in the median and ventral parts of the caudal peduncle. Investigations concerning the phylogenetic setting of the new genus Cerinichthys led to a proposal for a revision of the Halecomorphi, with Cerinichthys as a basal member of the new order Ophiopsiformes. The new family Ophiopsiellidae, as replacement for Ophiopsidae, within the Ophiopsiformes, are ganoin-scaled Halecomorphi with one horizontally elongated dorsal fin or two dorsal fins. The Ionoscopidae are proposed to belong in the Amiiformes, and the order Ionoscopiformes needs to be reconsidered. The more basal Halecomorphi with massive ganoin scales remain poorly known, compared with the more advanced halecomorph group of the Amiidae. Closer investigation of their morphology and taxonomic relationships is therefore important for understanding broader patterns of halecomorph evolution.http://zoobank.org/urn:lsid:zoobank.org:pub:0D13F672-DBC1-4484-AE30-7D360DCD3123SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Ebert, M. 2018. Cerinichthys koelblae, gen. et sp. nov., from the Upper Jurassic of Cerin, France, and its phylogenetic setting, leading to a reassessment of the phylogenetic relationships of Halecomorphi (Actinopterygii). Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1420071.

Abstract 21347: Percutaneous Coronary Intervention With Drug Eluting Stents is as Efficacious as Coronary Artery Bypass Grafting in Unprotected Left Main Disease: A Meta Analysis

Background: CABG is the preferred revascularization strategy for unprotected left main disease. Multiple small scale trials and registry data showed that PCI with Drug Eluting Stents is a non-inferior strategy and is a Class IIa ACC/AHA recommendation in a high surgical risk patient with favorable anatomy. However, two recent large scale randomized trials have shown conflicting evidence. We conducted a meta-analysis of the existing data to compare the long term outcomes of PCI with DES vs CABG for left main stenosis. Methods: 4 randomized and 8 non-randomized studies involving 10,284 patients were included. The primary endpoint was a composite of death, stroke or MI at three years or longer. Secondary end points were MACCE (death, stroke, MI or repeat revascularization) and it's individual components. Heterogeneity of the studies was analyzed by Cochran’s Q statistics. The Mantel-Haenszel random effects model was used to calculate the combined odds ratio for outcomes. An independent analysis was performed for the randomized data only. Results: There was no significant difference in the primary composite outcome between PCI and CABG at long term follow up. However the MACCE was significantly higher in PCI, primarily driven by significantly high repeat revascularization. The stroke rate was lower in PCI, although not significant. Analysis of randomized data also yielded similar results. A subgroup analysis stratified by SYNTAX score showed that MACCE and repeat revascularization were not significantly different between PCI and CABG in low to intermediate SYNTAX score (&lt;33) while they were significantly higher in PCI in high SYNTAX score. Conclusion: There was no significant difference in the primary composite outcome between PCI with DES and CABG at long term follow up. Repeat Revascularization in PCI was also not different from CABG in left main stenosis with low SYNTAX score. PCI with DES can be considered as a reasonable alternate strategy in isolated left main stenosis.

Rapid cooling and cold storage in a silicic magma reservoir recorded in individual crystals.

Silicic volcanic eruptions pose considerable hazards, yet the processes leading to these eruptions remain poorly known. A missing link is knowledge of the thermal history of magma feeding such eruptions, which largely controls crystallinity and therefore eruptability. We have determined the thermal history of individual zircon crystals from an eruption of the Taupo Volcanic Zone, New Zealand. Results show that although zircons resided in the magmatic system for 103 to 105 years, they experienced temperatures >650° to 750°C for only years to centuries. This implies near-solidus long-term crystal storage, punctuated by rapid heating and cooling. Reconciling these data with existing models of magma storage requires considering multiple small intrusions and multiple spatial scales, and our approach can help to quantify heat input to and output from magma reservoirs.

Spatio-temporal variation in European starling reproductive success at multiple small spatial scales.

Understanding population dynamics requires spatio-temporal variation in demography to be measured across appropriate spatial and temporal scales. However, the most appropriate spatial scale(s) may not be obvious, few datasets cover sufficient time periods, and key demographic rates are often incompletely measured. Consequently, it is often assumed that demography will be spatially homogeneous within populations that lack obvious subdivision. Here, we quantify small-scale spatial and temporal variation in a key demographic rate, reproductive success (RS), within an apparently contiguous population of European starlings. We used hierarchical cluster analysis to define spatial clusters of nest sites at multiple small spatial scales and long-term data to test the hypothesis that small-scale spatio-temporal variation in RS occurred. RS was measured as the number of chicks alive ca. 12 days posthatch either per first brood or per nest site per breeding season (thereby incorporating multiple breeding attempts). First brood RS varied substantially among spatial clusters and years. Furthermore, the pattern of spatial variation was stable across years; some nest clusters consistently produced more chicks than others. Total seasonal RS also varied substantially among spatial clusters and years. However, the magnitude of variation was much larger and the pattern of spatial variation was no longer temporally consistent. Furthermore, the estimated magnitude of spatial variation in RS was greater at smaller spatial scales. We thereby demonstrate substantial spatial, temporal, and spatio-temporal variation in RS occurring at very small spatial scales. We show that the estimated magnitude of this variation depended on spatial scale and that spatio-temporal variation would not have been detected if season-long RS had not been measured. Such small-scale spatio-temporal variation should be incorporated into empirical and theoretical treatments of population dynamics.

Optimal design of multi-storage network for combined sewer overflow management using a diversity-guided, cyclic-networking particle swarm optimizer – A case study in the Gunja subcatchment area, Korea

Multiple small-scale, distributed storage facilities have recently received much attention owing to their effectiveness for combined sewer overflow (CSO) mitigation. In this line of research, designing the optimal configuration of storage tanks in a sewer network is very challenging, and thus relatively few studies have been made to this day. To solve such a large-scale complex multimodal optimal design problem, a meta-heuristic particle swarm optimization-based design methodology of complex sewer networks for CSO management is developed. This search engine includes two mechanisms: a diversity-guided three-phase velocity update law and restricted social best searching based on the cyclic network structure. It allows regions of the design space to be explored efficiently by driving each particle to share information in switching the velocity update mechanism only with a set of neighboring particles via a fixed near-neighbor interaction structure. Therefore, the movement of a particle is no longer driven by the global best position of the entire swarm, which enhances the diversification attitude of the scheme. Its implementability under an actual environment is demonstrated by applying it to a combined sewer network case study of a complex large-scale multi-storage network in the Gunja subcatchment area located in Seoul, Republic of Korea. The simulation results indicate that the developed particle swarm optimization–based design methodology exhibits not only superior reliability but also high practicality, simplicity, and implementability for optimal planning of real-life CSO storage facilities.

Generalized Batchelor functions of isotropic turbulence

We generalize Batchelor’s parameterization of the autocorrelation functions of isotropic turbulence in a form involving a product expansion with multiple small scales. The richer small scale structure acquired this way, compared to the usual Batchelor function, is necessary so that the associated energy spectrum approximate well actual spectra in the universal equilibrium range. We propose that the generalized function provides an approximation of arbitrary accuracy for actual spectra of isotropic turbulence over the universal equilibrium range. The degree of accuracy depends on the number of higher moments which are determinable and it is reflected in the number of small scales involved. The energy spectrum of the generalized function is derived, and for the case of two small scales is compared with data from high-resolution direct numerical simulations. We show that the compensated spectra (which illustrate the bottleneck effect) and dissipation spectra are encapsulated excellently, in accordance with our proposal.

Development of small scale cell culture models for screening poloxamer 188 lot-to-lot variation.

Shear protectants such as poloxamer 188 play a critical role in protecting cells during cell culture bioprocessing. Lot-to-lot variation of poloxamer 188 was experienced during a routine technology transfer across sites of similar scale and equipment. Cell culture medium containing a specific poloxamer 188 lot resulted in an unusual drop in cell growth, viability, and titer during manufacturing runs. After switching poloxamer lots, culture performance returned to the expected level. In order to control the quality of poloxamer 188 and thus maintain better consistency in manufacturing, multiple small scale screening models were developed. Initially, a 5L bioreactor model was established to evaluate cell damage by high sparge rates with different poloxamer 188 lots. Subsequently, a more robust, simple, and efficient baffled shake flask model was developed. The baffled shake flask model can be performed in a high throughput manner to investigate the cell damage in a bubbling environment. The main cause of the poor performance was the loss of protection, rather than toxicity. It was also suggested that suspicious lots can be identified using different cell line and media. The screening methods provide easy, yet remarkable models for understanding and controlling cell damage due to raw material lot variation as well as studying the interaction between poloxamer 188 and cells.

Study of Flood Control Capability and Advanced Application of Multiple Dams Constructed in Series

The new concept for flood control called ‘Cascade’ method which permits dams to overflow around an upstream region with a sequence of dams constructed in a river is proposed. Multiple small scale dry dams should be constructed in series instead of a large scale dam in order to prevent flood disaster and preserve the natural environment. Recently a flood control dam with a bottom outlet hole as its regular spillway, known as ‘dry dam’, has been reviewed, planned and built in some sites in Japan. Under a condition of a common reservoir capacity, the Cascade type flood control permitting upstream dams to overflow except for the most downstream dam in a river is compared with a conventional one not to overflow each dam in a numerical simulation. As a result, it is made clear that the Cascade method using multiple dry dams is much more effective than the conventional one. In this connection, the Cascade type flood control method permitting upstream dams to overflow from emergency spillways except for the most downstream dam can be applied to normal storage dams with slide gates operated conventionally. Therefore, it could become an effective adaptation method for the global warming problem since it is performed by only changing how to operate slide gates in existing storage dams constructed in series. In addition, we also propose a new type of dry dam that has a closable and openable gate for its regular spillway primarily to retain the water for the water utilization. The new type of dry dam, which should be constructed in the upper reach away from the existing downstream storage dam needing still more its capacity for water utilization, ensures the amount of water available for the use by closing the regular spillway after the new dry dam is at full capacity, and the flood control capacity of the dams including the new dry dam is stronger than that of the normal dams owing to the storage function with the new dry dam. The new dry dams may improve the water utilization, the flood control, and environmentfriendliness under the current condition in Thailand damaged by the severe flood in 2011.

Is There a Continuing Rationale for Swidden Cultivation in the 21st Century?

Large areas of the tropical forest landscapes are still occupied – partly or fully – by swidden cultivation, but it is also clear that in many areas both the extent and intensity of swidden cultivation are changing. This is not new as it has always been a dynamic system used when it is opportune and changed or even dropped when other more favorable options for land and labor use, income, etc. appear. It seems that these changes now occur faster in some regions and slower or not at all in others (van Vliet et al. 2012). Political and economic pressures are the main drivers that have encouraged or enforced such changes, particularly towards more intensive agricultural practices or to other types of land use (urbanization, large scale plantations, protected areas, extractive concessions, etc.). However, the nature of these changes in swidden cultivation are not well documented, partly because swidden fields and the various successional stages of woody re-growth associated with it are often categorized as ‘unclassified’ or ‘degraded’ land or lumped together with other land cover categories (Padoch et al. 2007; Schmidt-Vogt et al. 2009). Swidden cultivation is a smallholder category that government authorities find difficult to quantify because it forms part of a complex and diversified production system, together with other multiple small scale land use types (Gleave 1996; Padoch et al. 2007) and there is also little political interest in understanding the logic inherent to swidden cultivation and to quantify the number of people dependent on swidden as they are usually not a desired category of farmers to have appearing in official statistics (Mertz et al. 2009a). It is obvious that if such basic information is unavailable, planners and policymakers have no sound basis for decisions on land use and development in the poorest regions of their countries. In 2009, as a response to the lack of information on swidden cultivation, a special issue was published in Human Ecology providing a comprehensive and mainly literature based overview of swidden cultivation in Southeast Asia (Mertz et al. 2009b). Some of the articles highlighted the problem of defining and measuring the spatial and demographical extent of swidden (Mertz et al. 2009a; Messerli et al. 2009; Schmidt-Vogt et al. 2009), others addressed the drivers and impacts of swidden change by analyzing the political economy of swidden and the implications of swidden transformation for rural livelihoods (Cramb et al. 2009; Fox et al. 2009), and a final set of articles addressed the impacts on the environment of swidden cultivation as well as of the systems that are replacing swidden cultivation (Bruun et al. 2009; Rerkasem et al. 2009; Ziegler et al. 2009). That special issue settled a number of questions about swidden cultivation in Southeast Asia, but also raised a number of other concerns. Indeed, despite a relatively large number of case studies from that region, the knowledge of swidden cultivation is still very patchy and many essential elements such as exact areas under swidden management, the number of persons involved, and the livelihood and environmental consequences of swidden transformations remained only partially N. Van Vliet :O. Mertz (*) : T. Birch-Thomsen Department of Geosciences and Natural Resource Management, University of Copenhagen, Oster Voldgade 10, 1350 Copenhagen K, Denmark e-mail: om@geo.ku.dk

On asymptotic behavior for 1‐dimensional functional of Ginzburg‐Landau type with internally‐externally created oscillations of minimizers

AbstractIn this note we provide a kind of generalization of the well‐known notion of internally (externally, resp.) created oscillations of minimizers of non‐convex integrands in the calculus of variations. As an example, we consider a class of 1‐dimensional Ginzburg‐Landau functionals (the simplest case being considered in the paper G. Alberti, S. Muller: A new approach to variational problems with multiple scales, Comm. Pure Appl. Math. 54, 761–825 (2001)). We describe asymptotic behavior leading to multiple small scale separation as parameter epsilon tends to zero. (© 2012 Wiley‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Purify First: Rapid expression and purification of proteins from XMRV

Purifying proteins from recombinant sources is often difficult, time-consuming, and costly. We have recently instituted a series of improvements in our protein purification pipeline that allows much more accurate choice of expression host and conditions and purification protocols. The key elements are parallel cloning, small scale parallel expression and lysate preparation, and small scale parallel protein purification. Compared to analyzing expression data only, results from multiple small scale protein purifications predict success at scale-up with greatly improved reliability. Using these new procedures we purified eight of nine proteins from xenotropic murine leukemia virus-related virus (XMRV) on the first attempt at large scale.

A result in asymptotic analysis for the functional of Ginzburg-Landau type with externally imposed multiple small scales in one dimension

A result in asymptotic analysis for the functional of Ginzburg-Landau type with externally imposed multiple small scales in one dimension

Role of rural land use management in flood and coastal risk management

AbstractFlood risk is influenced by the rate and speed of rural land runoff within the catchment and by flow attenuation in the floodplain. Most research to date has demonstrated that the overall flood risk benefits of multiple small scale land management changes at a large catchment scale are difficult to determine and, in some situations, may not provide significant benefits in flood events. Measures may, however, offer potential for attenuation, improving flood warning times and therefore reducing flood damages. Climate change and major legislative drivers such as the Water Framework Directive will also further drive the need to consider different approaches to how land is managed and the impact that this may have on flood and coastal risk management.