bluuebunny/crossref_metadata_2025 huggingface dataset:
Methane emission and control at Lingan Colliery
Authors: Kond B W , Kochhar J
Published: September 2017

Lingan mine is one of two underground collieries operated by the Cape Breton Development Corporation in Nova Scotia, Canada. The mine produces about 1.4 million tonnes of saleable bituminous coal from the 2.2 m thick Harbour Seam by advancing longwall method. The
workings are submarine. The Harbour Seam is fourth in a sequence of eleven seams identified in the Sydney Coalfield. It is gassy and the gas emission increases with depth. Total gas emission at Lingan increased from about 29 m3 /tonne in 1978 when the workings were at a depth of about 400 m to the
present 50 m3 /tonne at a depth of 600 m. The ventilation at Lingan is provided by a 1350 kW Sheldon Centrifugal fan with variable inlet vanes exhausting at a rate of 190 m3 /s and 450 mm w.g. Each wall is supplied with air in excess of 30m3/s. Because of the submarine workings, surface boreholes to
control methane in gobs during longwall mining is not practical and dilution with ventilation alone is inadequate and costly. Hence, the cross-measure borehole technique was adopted in the Sydney Coalfield in the 1950's and the current practice was developed over the years by trial and error. The
holes are drilled in the return gate, parallel to the faceline, at an angle of 50° - 600 to the horizontal, to a depth of 40 m with a 11 m standpipe cemented into it. The roof holes are spaced at 25 m and those in the floor at 50-75 m. The active holes, which could number to a maximum of
fourteen at any one-time are connected to a 200 mm pipeline. Until April 1985, the pipeline was connected to vacuum pumps underground and the extracted methane was discharged at a point in the main return airway where the ventilation was sufficient to quickly dilute it to a safe level. However, the
district methane pipelines are now connected to a main trunk pipeline and a new surface extraction plant capable of handling up to 120,000 m3 per day of gas at a vacuum of 465 mm of mercury. It is now contemplated not only to increase the number of methane drainage holes in each district to improve
capture ratio, but also to extract methane from old workings. -A Sieger Methane Monitoring system is used on each wallface with automatic power cutoff at 1.25% methane. A computer based remote environmental monitoring system is now installed and is expected to be fully operational later this
year. This will monitor wallface ventilation, fan performance and methane drainage on a continuous basis.
A suggested method for estimating bolt lengths and loadings for support of rectangular openings
Authors: Das B , Stimpson B
Published: September 2017

Where the structural geological conditions are not well defined, the choice of roof bolt patterns and length and the calculation of expected loading are difficult. In this paper the authors propose an elliptically shaped zone in the roof that will require
support. This ellipse is assumed to bound a rectangular shaped underground excavation where the volume of rock mass requiring support is dependent on the span and height of opening, the in-situ stress ratio, and the CSIR Rock Mass Rating. Some case histories are slected to validate this model. It is
suggested that data on rock quality, in-situ stress, and relative movement in the roof are required to optimize rock bolts layout.
Longwall mining under the ocean at Cape Breton collieries
Authors: Konda B W , Kochhar J K
Published: September 2017

Cape Breton is an island at the northeastern extremity of mainland Nova Scotia on Canada's eastern seaboard. The Sydney Coalfield, located on the east coast of Cape Breton, is part of a large carboniferous basin beneath the Atlantic Ocean between the shores of
Cape Breton and the province of Newfoundland. The coalfield is Pennsylvanian in age and contains the largest coal reserves in Eastern Canada. More than 98% of the coalfield is submarine. Cape Breton Development Corporation (CBDC), a federal Crown corporation, currently operates two underground
coal collieries, Lingan and Prince, producing nearly 2.5 million tonnes of saleable coal and has under development two new collieries, Phalen and DonkinMorien. All currently operating and planned collieries are 'slope collieries'. While room and pillar mining has been practised at shallower depths
in the past, all current workings are based on 'U' layout longwall (advancing at Lingan and retreating at Prince) system with full caving. In designing submarine workings, the major concern is the prevention of ingress of seawater consistent with optimal extraction of resources. Guidelines based on
experience and engineering are established for partial to full extraction. The important guideline followed in the Sydney Coalfield is that the strain at the seabed should not exceed 8.5 mm/m as the result of extraction. The longwall faces are fully mechanized with ranging double drum shearers,
armoured face conveyors and twolegged hydraulic shield supports. Roadheaders are deployed in maingates. The coal is transported to the surface by a system of belt conveyors whereas men and materials are transported by a rope haulage system in the slopes and by diesel locomotives in the maingates.
Because of the submarine workings, mine openings cannot be at the desired location. Hence, efficient layout from the point of view of optimal extraction of resources is not feasible. As the mine progresses, the length of ventilation circuits and transportation distances for men and materials
increase. This results in the requirement of higher ventilation pressures and reduced effective shift working time which contribute to higher costs and lower productivity. Efforts are being made to overcome these shortcomings by the introduction of advanced technology in all aspects of operations:
ventilation design by computer simulations, methane control by crossmeasure borehole drainage, environmental monitoring by computerized remote monitoring system and reduction in.travel time by highspeed haulage system are a few of these aspects.
A strategy for measuring off-highway truck rolling resistances
Authors: Stuart N J , Kolada R J
Published: September 2017

This report describes the need for a convenient method to measure the rolling resistance experienced by trucks travelling on mine haulage roads. The importance of knowing the rolling resistance produced by haulage roads is illustrated by an example of its effect
on the productivity of a haulage fleet and the consequent effect on the economics of the mine. A proposal is outlined for a resistance measuring test vehicle which is towed by a small truck and includes suggestions for both the construction of the test vehicle and the instrumentation package. Also
included is a discussion on how the test data may be calibrated to predict the resistance experienced by the various types of mobile mining machinery.
Rock characterization microhardness technique
Authors: Das B
Published: September 2017

yes
A review of an on board truck management systems
Authors: Srajer V
Published: September 2017

In the paper an overview of the existing truck monitoring systems available on the North American market is presented. The systems were evaluated based on their functions, diagnostics and integrated system control. The nonopeator dependent onboard truck
management systems are recognized as having greatest potential for installation on mining trucks in Canadian surface coal mines. The Canada Centre for Mineral and Energy Technology (CANNET), Calgary Coal Research Laboratory and the Canadian .coal mining industry are preparing a proposal to jointly
fund, demonstrate and evaluate such a management system at producing surface coal mine in Canada.
A rapid sequential tracer gas analyzer suitable for use in the underground environment
Authors: Kennedy D J
Published: September 2017

Tracer gas measurement is an advantageous technique for evaluating mine ventilation problems. A portable instrument capable of rapid tracer gas measurements in an actual mining environment would be a most valuable tool. This report describes a prototype
instrument which was used in the uranium mines of Elliot Lake, Ontario.
The effect of different crushers on fines generation from western Canadian friable coals.
Authors: Mikhail M W , Mikula R J , Humeniuk O E
Published: September 2017

The fines production during coal crushing has been investigated and related to microstructural coal characteristics. Four types of crushers (Jaw crusher, Hammer mill, Coalpactor and Bradford breaker) were used to reduce the top size of five coals from different
operating mines. Laboratory tests were done to indirectly measure the degree of friability of the coals and to relate this to the fines generation that occurs during crushing. The amount of fines generated from a particular coal has been shown to be dependent upon coal friability. For a particular
crusher, the fines are proportional to the friability. For a particular coal, a coal with a high friability produces a small variation in the amount of fines (as a function of the crusher used) whereas a coal with a low friability produces a large variation in the amount of fines. The Bradford
breaker generated the least fines and the Jaw crusher generated the greatest amount of fines. Similarly, the Bradford breaker produced the largest average particle size while the Hammer mill and Coalpactor produced the smallest. A linear relationship was indicated between the amount of fines
generated during crushing and the friability of the coal (as measured indirectly by the delta P index of gas desorption). The extensive fissuration of western Canadian coals is beneficial from a crushing and grinding point of view. This can be economically advantageous in preparing these coals for
applications that require fine particles for utilization.
Point load index' users guide: computer calculation of point load indices and rock strengths using an IBM-PC/AT
Authors: Issard M , Aston T R C
Published: September 2017

Le présent rapport donne une description du programme "POINT LOAD INDEX" (indice de charge ponctuelle) qui permet de calculer l'indice de charge ponctuelle, l'indice normalisé (Is - NX équivalent à la dimension de l'échantillon) ainsi que
la résistance à la compression et à la traction uniaxiales. Ce programme est écrit en langage BASIC A Version 3,10 pour un IMB-PC/AT.
Continuous mining systems for surface mining of coal
Authors: Singhal R K , Golosinski T S
Published: September 2017

Traditional mining equipment such as shovel/trucks, draglines, front-end loaders and scrapers are the main stay of surface mining, however, a new breed of equipment is being increasingly applied. These include hydraulic Shovels, bucket wheel excavators, hydraulic
bucket wheels, belt conveyors, high angle conveyors and cross-pit conveyors. The various components can be combined to provide a continuous and flexible material handling system for large, as well as small sized operations. High volume operations are dependent on continuous mining systems for their
success. A variety of equipment of different sizes and mobility is either available or in an advanced stage of development. In some situations material handling systems are supplemented by crushing equipment to break large rocks This paper reviews the current practice in continuous mining systems
and attempts to highlight the manner and advantages of blending conventional mining equipment and newer equipment resulting in greater productivity and reduced material handling costs.
Surface mining of Canadian coal: equipment selection and mining methods
Authors: Singhal R K , Golosinski T S
Published: September 2017

La production canadienne de charbon est actuellement d'environ 60 millions de tonnes par année, dont quelque 27 millions de tonnes sont exportées. L'Ouest du Canada (l'Alberta, la Colombie-Britannique et la Saskatchewan) est à l'origine de plus de
95 % de cette production; presque tout le charbon est exploité en surface. Les conditions géologiques de bon nombre des bassins houillers de l'Ouest sont complexes. Le charbon est friable et les filons sont fortement inclinés, très cisaillés et intensément
plissés et faillés, notamment dans la région montagneuse, où de nombreuses mines de surface sont actuellement exploitées. Entre 15 et 20 filons houillers peuvent être présents à la fois, leur épaisseur réelle pouvant varier de 2,5 mètres à
plus de 8 mètres. Cette étude décrit les méthodes normalement utilisées pour l'exploitation du charbon et de la lignite dans l'Ouest du Canada, qui se fondent sur l'emploi des draglines ainsi que des camions et des pelles. Elle souligne les difficultés associées
à l'exploitation des filons multiples fortement inclinés de charbon friable, soit les faibles taux de récupération, la dilution marquée et le problème du nettoyage du charbon fin dans les lavoirs, ainsi que les mesures prises en vue de résoudre ces problèmes.
Les mines canadiennes sont fortement mécanisées et utilisent le matériel minier de pointe. Les exploitants se servent de plus en plus de la technologie fondée sur les ordinateurs et les micro-processeurs, ce qui fait que les mines de charbon canadiennes exploitées en surface
sont parmis les plus efficaces du monde.
Some remarks on the beating efficiency of the photomixing techniques
Authors: Mansour N A
Published: September 2017

Two techniques are used to detect scattered light. These may be classified as the direct photodetection and the photomixing techniques. The latter is the most commonly used because it gives better S/N ratio. However, it requires stringent spatial requirements.
advantages and disadvantages, and S/N ratio formulas of the two techniques are presented. The beating efficiency is calculated for the case of mixing of two plane waves and the results are given. The beating efficiency of two spherical waves originated from two point sources, is calculated for
various shapes of the photodetector. It was found that the beating efficiency is a function of the detector shape and the incidence angle of the two light beams on the detector.
An object-based seafloor classification tool using recognition of empirical angular backscatter signatures
Authors: Alevizos E
Published: September 2017

This study presents a novel concept of seafloor acoustic mapping utilizing the angular dependence of high density soundings. A prerequisite is that data should result from a backscatter-dedicated survey (>100% swath overlap) in order to obtain
small-scale seafloor areas ensonified from multiple incidence angles. Accordingly, backscatter data should be geometrically and radiometrically corrected in order to represent only variations due to seafloor type. This method is considered as a mixture of OBIA with empirical ARA and pattern
recognition concepts and it provides supervised classification based on empirical backscatter angular signatures of a known set of seafloor types. Therefore it requires a library with all angular signatures corresponding to ground truth locations (seafloor type, dB and angle). The backscatter only
needs to be stable and hence this approach is not only applicable on calibrated sonars but works for any MBES system that records backscatter in a stable way. The library should consist of sediment samples, underwater images and/or video which are used to drive the classification and validate its
results. Ideally, the ground truth set should cover all different seafloor types from the study area. The concept is that angular backscatter signatures of known seafloor types that have been extracted from fine square areas of seafloor can be utilized for comparison with angular signatures of
unknown seafloor. Initially, the study area is segmented into fine squares within which soundings from various beam-angles fall. The smaller the square size, the higher the seafloor homogeneity can be achieved; hence more representative angular backscatter signatures can be extracted for each
seafloor type. In this study 5x5 m squares were used for representing naturally homogeneous seafloor. By extracting the angular signatures from the vicinity of sediment sample locations it was possible to use them as reference vectors for performing supervised classification. The classification
works in the following way: vectors carrying the mean backscatter value per swath angle are being created from each group of soundings belonging to the same square. Following, each vector is compared to the reference vectors that represent ground-truthed seafloor types. The comparison tests whether
the backscatter values of the vector under-comparison fall within a user-defined envelope (range of values) above and below the mean backscatter values of the reference vectors. If the backscatter values for the majority (>85%) of corresponding swath angles belong to the envelope of a
reference vector, then these soundings are assigned with the class number of the reference vector. Empirical ARA is more flexible in describing seafloor heterogeneity, compared to physical backscatter models, therefore allowing for classification of a wider variety of seafloor types in a consistent
way.
Submerged channels of the Eastern Brazilian Continental Shelf: can the slope value be used as potential surrogates of reef environments?
Authors: Araújo T C M , Camargo J M R , Ferreira B P , Maida M
Published: September 2017

The Eastern Brazilian Continental Shelf (EBCS) is narrow, shallow and predominantly covered by biogenic sediments. Bathymetric surveys have revealed the common occurrence of submerged channels, related to the largest watersheds in the region and probably carved
during periods of marine regression. With its break located between 40 and 80 metres deep, the EBCS was subjected to sub-aerial erosion for long periods, which justifies the occurrence of these erosive features related to continental drainage.
Based on a DEM with spatial resolution of 10 metres, the slope values of a section of the continental shelf of the state of Pernambuco were extracted. This initiative indicated an average slope value of 0.38°, consistent with that expected for a continental shelf. However, along the edges of
three submerged channels the slope is more pronounced, with values generally between 3 and 45°. Therefore, in order to verify the characteristics of these steep reliefs, 03 video-transects were performed in two sectors of the Zieta Channel with a GoPRO 3 Black. Video-transects I and II were
situated about 18 kilometres off the coast, while video-transect III was about 30 kilometres.
The data analysis involved the integration of the three parameters: substrate, geomorphology, and biota. The seascapes in each video-transect were defined such as: predominant, secondary or occasional. The record of combinations of substrate characteristics, geomorphology and biota occurrences also
contributed to the definition of an associative pattern between the physical characteristics and the biological assemblages recorded.
Extreme values of slope (20-45°) are related to seascapes dominated by large rocky outcrops, cut by small channels and with relative structural complexity, as well as fish, sponges, algae and corals. On the other hand, values of slopes between 3 and 8°, composed seascapes dominated by
small rocky outcrops, with irregular surface, usually covered by algae, and seascapes dominated by sub-outcrops, associated with rocky bottoms, sponges and corals. The flat reliefs (0-3°), related to the thalweg, harboured seascapes dominated by unconsolidated substrates, with bioturbation and
occurrence of dense spots of algae of the genus Halimeda.
From these preliminary results, it can be suggested that the slope presented potential to be considered a surrogate for seascapes dominated by consolidated substrates and associated reef environments. This potential should be better investigated through new video surveys, contributing greatly to the
consolidation of this relationship between slope, seascapes and benthic habitats, which, in turn, may guide the most appropriate design of Marine Protected Areas, as well as management measures of their fishing resources.
Numerical Study on Skin Friction and Shock Inception in Various Geometries of Supersonic Nozzle
Authors: Jassim E.I.
Published: September 2017

In the present study, a numerical simulation is conducted to predict the influence of convergent-divergent nozzle geometry and NPR on the skin friction and shockwave location. Various shapes of nozzles are numerically simulated using the Computational Fluid Dynamics code. The shock position is examined to demonstrate the impact of nozzle shape on its location. Skin friction is shown to be smoothly decreasing at the divergent part of the nozzle for all NPRs lower than 2.0. However, an inverse behavioural trend was observed at NPR equal to 2. This could be attributed to the fact that the large disturbance of fluid near the wall is the major factor behind such an oddity. The results also show that the shock position is reliant on the nozzle geometry at certain NPR.
Effect of Underbody Diffuser on the Aerodynamic Drag of Vehicles in Convoy
Authors: Aulakh D.J.S.
Published: September 2017

Current study examines the effect on coefficient of drag (Cd) of convoy of two reference car bodies (Ahmed body) by employing underbody diffuser on lead body. CFD analysis of convoy is done using Shear-Stress-Transport model under moving ground conditions. The lead bodyâ€™s diffuser length is taken as 222m with diffuser angle of 0Â° (no diffuser), 3Â°, 5ï‚°, 7Â°, 9Â°, 15Â°, 20Â°, 25Â°and 30Â° each at inter-vehicular 0.25 and 0.75 body length. Each configuration resulting was analyzed with lead body backlite angle of 25Â° (pre-critical) and 35Â° (post-critical) with follow body backlite angle remaining 25Â°. To understand the flow features developed on Ahmed body due to an underbody diffuser a preliminary CFD analysis is done on an isolated body with 25Â° and 35Â° backlite angles by applying each diffuser angle in current study. CFD analyses are conducted after performing two validation analyses from previous studies. The drag on lead and follow vehicles was found to also depend on the axial vortices due to diffuser in addition to those from backlite surface of lead body. Average drag on cases with diffuser is found to be lesser than the no diffuser cases up to a certain diffuser angle. Thus applying diffuser has resulted in potential for reducing the overall drag on convoy by deciding optimum configuration.
An efficient approach for treating composition-dependent diffusion within organic particles
Authors: O'Meara Simon , Topping David O. , Zaveri Rahul A. , McFiggans Gordon
Published: September 2017

Abstract. Mounting evidence demonstrates that under certain conditions the rate of component partitioning between the gas and particle phase in atmospheric organic aerosol is limited by particle-phase diffusion. To date, however, particle-phase diffusion has not been incorporated into regional atmospheric models. An analytical rather than numerical solution to diffusion through organic particulate matter is desirable because of its comparatively small computational expense in regional models. Current analytical models assume diffusion to be independent of composition and therefore use a constant diffusion coefficient. To realistically model diffusion, however, it should be composition-dependent (e.g. due to the partitioning of components that plasticise, vitrify or solidify). This study assesses the modelling capability of an analytical solution to diffusion corrected to account for composition dependence against a numerical solution. Results show reasonable agreement when the gas-phase saturation ratio of a partitioning component is constant and particle-phase diffusion limits partitioning rate ( <  10 % discrepancy in estimated radius change). However, when the saturation ratio of the partitioning component varies, a generally applicable correction cannot be found, indicating that existing methodologies are incapable of deriving a general solution. Until such time as a general solution is found, caution should be given to sensitivity studies that assume constant diffusivity. The correction was implemented in the polydisperse, multi-process Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) and is used to illustrate how the evolution of number size distribution may be accelerated by condensation of a plasticising component onto viscous organic particles.
Soil water regulates the control of photosynthesis on diel hysteresis between soil respiration and temperature in a desert shrubland
Authors: Wang Ben , Zha Tian Shan , Jia Xin , Gong Jin Nan , Bourque Charles , Feng Wei , Tian Yun , Wu Bin , Zhang Yu Qing , Peltola Heli
Published: September 2017

Abstract. Explanations for the occurrence of hysteresis (asynchronicity) between diel soil respiration (Rs) and soil temperature (Ts) have evoked both biological and physical mechanisms. The specifics of these explanations, however, tend to vary with the particular ecosystem or biome being investigated. So far, the relative degree of control of biological and physical processes on hysteresis is not clear for drylands. This study examined the seasonal variation in diel hysteresis and its biological control in a desert-shrub ecosystem in northwest (NW) China. The study was based on continuous measurements of Rs, air temperature (Ta), temperature at the soil surface and below (Tsurf and Ts), volumetric soil water content (SWC), and photosynthesis in a dominant desert shrub (i.e., Artemisia ordosica) over an entire year in 2013. Trends in diel Rs were observed to vary with SWC over the growing season (April to October). Diel variations in Rs were more closely associated with variations in Tsurf than with photosynthesis as SWC increased, leading to Rs being in phase with Tsurf, particularly when SWC > 0.08 m3 m−3 (ratio of SWC to soil porosity  =  0.26). However, as SWC decreased below 0.08 m3 m−3, diel variations in Rs were more closely related to variations in photosynthesis, leading to pronounced hysteresis between Rs and Tsurf. Incorporating photosynthesis into a Q10-function eliminated 84.2 % of the observed hysteresis, increasing the overall descriptive capability of the function. Our findings highlight a high degree of control by photosynthesis and SWC in regulating seasonal variation in diel hysteresis between Rs and temperature.
The effect of GCM biases on global runoff simulations of a land surface model
Authors: Papadimitriou Lamprini V. , Koutroulis Aristeidis G. , Grillakis Manolis G. , Tsanis Ioannis K.
Published: September 2017

Abstract. Global climate model (GCM) outputs feature systematic biases that render them unsuitable for direct use by impact models, especially for hydrological studies. To deal with this issue, many bias correction techniques have been developed to adjust the modelled variables against observations, focusing mainly on precipitation and temperature. However, most state-of-the-art hydrological models require more forcing variables, in addition to precipitation and temperature, such as radiation, humidity, air pressure, and wind speed. The biases in these additional variables can hinder hydrological simulations, but the effect of the bias of each variable is unexplored. Here we examine the effect of GCM biases on historical runoff simulations for each forcing variable individually, using the JULES land surface model set up at the global scale. Based on the quantified effect, we assess which variables should be included in bias correction procedures. To this end, a partial correction bias assessment experiment is conducted, to test the effect of the biases of six climate variables from a set of three GCMs. The effect of the bias of each climate variable individually is quantified by comparing the changes in simulated runoff that correspond to the bias of each tested variable. A methodology for the classification of the effect of biases in four effect categories (ECs), based on the magnitude and sensitivity of runoff changes, is developed and applied. Our results show that, while globally the largest changes in modelled runoff are caused by precipitation and temperature biases, there are regions where runoff is substantially affected by and/or more sensitive to radiation and humidity. Global maps of bias ECs reveal the regions mostly affected by the bias of each variable. Based on our findings, for global-scale applications, bias correction of radiation and humidity, in addition to that of precipitation and temperature, is advised. Finer spatial-scale information is also provided, to suggest bias correction of variables beyond precipitation and temperature for regional studies.
Origin of water in the Badain Jaran Desert, China: new insight from isotopes
Authors: Wu Xiujie , Wang Xu-Sheng , Wang Yang , Hu Bill X.
Published: September 2017

Abstract. To better understand the origin of water in the Badain Jaran Desert, China, water samples were collected from lakes, a spring and local unconfined aquifer for analyses of radiocarbon (14C), tritium (3H), stable hydrogen and oxygen isotope ratios (δ2H – δ18O), and d-excess values ( = δ2H – 8δ18O). A series of evaporation experiments were also conducted in the desert to examine how the isotopic signature of water may change during evaporation and infiltration under local environmental conditions. The results show that the lakes in the southeastern sand dune area are fed by groundwater discharging into the lakes and that local groundwater, on the other hand, is derived primarily from modern meteoric precipitation in the region. Although dissolved inorganic carbon (DIC) in groundwater yielded very old radiocarbon ages, the presence of detectable amounts of tritium in groundwater samples, together with their δ2H, δ18O and d-excess characteristics, strongly suggests that the old radiocarbon ages of DIC do not represent the residence time of water in the aquifer but are the result of addition of old DIC derived from dissolution of ancient carbonates in the aquifer. The data do not support the hypothesis that the water in the Badain Jaran Desert was sourced in remote mountains on the northern Tibetan Plateau. This study also finds no support for the hypothesis that present-day water resources in the desert were recharged by the precipitation that fell in the past during the early Holocene when the climate was much wetter than today. Instead, this study shows that both groundwater and lake water originated from meteoric precipitation in the region including mountainous areas adjacent to the desert under the modern climatic condition.
Wave–ice interactions in the neXtSIM sea-ice model
Authors: Williams Timothy D. , Rampal Pierre , Bouillon Sylvain
Published: September 2017

Abstract. In this paper we describe a waves-in-ice model (WIM), which calculates ice breakage and the wave radiation stress (WRS). This WIM is then coupled to the new sea-ice model neXtSIM, which is based on the elasto-brittle (EB) rheology. We highlight some numerical issues involved in the coupling and investigate the impact of the WRS, and of modifying the EB rheology to lower the stiffness of the ice in the area where the ice has broken up (the marginal ice zone or MIZ). In experiments in the absence of wind, we find that wind waves can produce noticeable movement of the ice edge in loose ice (concentration around 70 %) – up to 36 km, depending on the material parameters of the ice that are used and the dynamical model used for the broken ice. The ice edge position is unaffected by the WRS if the initial concentration is higher (≳ 0.9). Swell waves (monochromatic waves with low frequency) do not affect the ice edge location (even for loose ice), as they are attenuated much less than the higher-frequency components of a wind wave spectrum, and so consequently produce a much lower WRS (by about an order of magnitude at least).In the presence of wind, we find that the wind stress dominates the WRS, which, while large near the ice edge, decays exponentially away from it. This is in contrast to the wind stress, which is applied over a much larger ice area. In this case (when wind is present) the dynamical model for the MIZ has more impact than the WRS, although that effect too is relatively modest. When the stiffness in the MIZ is lowered due to ice breakage, we find that on-ice winds produce more compression in the MIZ than in the pack, while off-ice winds can cause the MIZ to be separated from the pack ice.
Are There Road Blocks to Access Micro-Credit From Selected Microfinance Banks in Delta State, Nigeria? Implications for Small Scale Farmers Sustainability!
Authors: Theophilus Miebi Gbigbi
Published: September 2017

The study was carried out to investigate the factors that affect small scale farmers to access fund and utilized for greater efficiency in production in Delta State, Nigeria. The logit model was used to analyze the data. A multi-stage random sampling technique was used for the study. Charts were used to analyze the socioeconomic characteristics of the farmers. About 120 farmers were interviewed using pretested questionnaire. The study showed that sex, education, farm size, cash balance, collateral, frequency of transaction and membership of cooperative society were positive and significant at 1%, 5% and 10% probability levels respectively. The coefficient of age, interest rate, household size and distance were negative and significant at 10% and 5% levels. The results of the study call for policies aimed at encouraging microfinance banks to consider the farmers in accessing credit to increase their output, income and productivity in the study area.
Measurement of straylight for glare assessment and driving.
Authors: Van den Berg Thomas JTP
Published: September 2017

In this review an overview of straylight as method to assess glare sensitivity for driver licensing will be given. Glare is an important safety issue while driving. It is well known that people stop driving at night because of glare when early cataract develops. It has been found to derive from the physical process of light scattering in the eye, causing a veil of straylight over the road scene. This veil lessens visibility, potentially up till complete blinding. By international agreement, glare is to be quantified by straylight based on the â€œequivalent luminanceâ€ concept. Normal standards have been defined, including age and cataract dependence. Straylight can be measured accurately with the psychophysical 2AFC â€œcompensation comparisonâ€ method, including a reliability check. A commercial instrument called C-Quant is marketed.Â  As straylight is a basic quality of the eye, also other aspects of quality of vision, such as face recognition, contrast sensitivity, etc. depend on it. Straylight is used in ophthalmology as early indication for cataract surgery. It is to a large degree independent from acuity. Practical aspects of straylight measurement and limit values for occupational testing will be discussed. Normal young values are around log(s)=0.9. For demanding professions a limit elevation of 2x (0.3 log, corresponding to 3 standard deviations) is proposed. For normal driving a limit elevation of 4x is proposed, corresponding to log(s)=1.5. Cataract surgery is indicated at log(s)=1.4.
Translating Professional Development for Teachers Into Professional Development for Instructional Leaders
Authors: Carlson Mary Alice , Heaton Ruth , Williams Molly
Published: September 2017

In recent years, teacher noticing of children's mathematical thinking has emerged as an important and generative construct in mathematics education (Sherin, Jacobs, & Philipp, 2011). Less is known about ways instructional leaders notice teachers' learning. Between 2011 and 2015, we facilitated professional development (PD) in which coaches, principals, and teachers studied mathematics teaching and learning together. Our initial focus on teacher decision-making was inadequate in meeting instructional leaders' learning needs. We adapted the PD to focus instructional leaders' attention on the work of learning teaching. Analysis of leaders' discourse revealed shifts from noticing teacher characteristics to noticing dilemmas and decision-making within teaching and coaching. Findings suggest new roles for teacher educators and new forms of PD for instructional leaders.
Remote Ischemic Conditioning
Authors: Boghossian Jano A. , Joseph Bellal , Slepian Marvin J. , Armstrong David G.
Published: September 2017

Remote ischemic conditioning involves the use of a blood pressure cuff or similar device to induce brief (3–5 min) episodes of limb ischemia. This, in turn, seems to activate a group of distress signals that has shown the potential ability to improve healing of the heart muscle and other organ systems. Until recently, this has not been tested in people with diabetic foot ulcers. The purpose of this review was to provide background on remote ischemic conditioning and recent data to potentially support its use as an adjunct to healing diabetic foot ulcers and other types of tissue loss. We believe that this inexpensive therapy has the potential to be deployed and incorporated into a variety of other therapies to prime patients for healing and to reduce morbidity in patients with this common, complex, and costly complication.
Fibular-Lengthening Osteotomy to Correct a Malunited Ankle Fracture Using Fresh-Frozen Femoral Head Allograft
Authors: Visser Harry J. , Malik Khawar , Djali Robert A.
Published: September 2017

Malreduction of a distal fibular fracture can lead to degenerative changes in the ankle joint. Previous studies have shown that the selective use of various fibular reconstructive osteotomies may halt the progression of degenerative arthritis by restoring the normal tibiotalar contact area and decreasing the stresses on the articular cartilage. In this case report, we achieved alignment with restoration of the talocrural angle and Shenton's line of the ankle using a transfibular osteotomy and an allogeneic fresh-frozen femoral head graft to fill the resultant defect. The advantage of this procedure is twofold. First, fibular-lengthening procedures may potentially decrease the eventual need for joint-sacrificing procedures such as an arthrodesis or arthroplasty. Second, an allograft allows for larger deficit correction without concern for donor-site morbidity. To our knowledge, this is the first case report using a fresh-frozen femoral head allograft for a fibular-lengthening osteotomy in the podiatric medical literature. Further research with larger patient populations is needed to establish whether fresh-frozen femoral head allograft is a reliable graft option for fibular-lengthening procedures.
Zerstörungsfreie Bewertung der strukturellen Substanz der Asphaltbefestigung mit Geofonen
Authors: Wang Dawei , Liu Pengfei , Otto Frédéric , Oeser Markus , Balck Henning
Published: September 2017

Die aktuell in Deutschland genutzten Verfahren zur Beurteilung der Substanz basieren vorwiegend auf der Analyse des Zustands der Oberfläche. Die Zielsetzung des vom Bundesministerium für Verkehr und digitale Infrastruktur beauftragten Forschungsprojekts „In‐Motion“ aus dem nationalen Innovationsprogramm Straße bestand darin, mithilfe verschiedener zerstörungsfreier Verfahren die strukturelle Substanz von Asphaltbefestigungen zu erfassen und zu bewerten. Dieser Ansatz wurde auf der Modellstraße der Bundesanstalt für Straßenwesen (BASt) validiert; auf dem Versuchsfeld der Modellstraße wurden zyklische Belastungen mit dem sog. Mobile Load Simulator (MLS10) zur Simulation von Strukturschädigungen in der Fahrbahn aufgebracht.

Durch eine systematische Analyse von Deflektionsmessungen bei bewegter Belastung wurden Rückschlüsse auf das Tragverhalten der Asphaltbefestigungen gezogen. Dabei wurden aus den gemessenen Deflektionen physikalisch begründete Struktur‐ und Materialparameter rechnerisch abgeleitet. Die Rückrechnung erfolgte mithilfe der Methode der finiten Elemente, wobei insbesondere auf eine realitätsnahe Abbildung des jeweiligen Belastungszustands durch bewegte Lasten geachtet wurde. Aus den gewonnenen Erkenntnissen wurde ein eigenständiges Modul erarbeitet, welches als Grundlage für eine konzeptionelle Erweiterung bestehender Pavement‐Managementsysteme hin zu einer realistischeren Berücksichtigung der Substanzwerte von flexiblen Befestigungen dienen kann.
Synthesis and Biological Evaluation of O‐Methylated Glycolipids Related to PGLs via Direct Stereoselective Glycosidation and Sequential Suzuki–Miyaura Coupling using Boracyclane
Authors: Sato Ko , Omahdi Zakaria , Shibata Kensuke , Sonoda Koh‐hei , Yamasaki Sho , Tanaka Hiroshi
Published: September 2017

Synthesis of O‐methylated glycolipids via direct stereoselective glycosidation whose sugar moieties are related to those in phenolic glycolipids (PGLs) is reported. Treatment of 2‐O‐methyl‐rhamnosyl imidates with I2 and nBu4NOTf resulted in their activation under low temperature and provided the α‐rhamnosides with excellent α‐selectivity. nBu4NOTf enhanced the electorophilicity of iodine. This methodology improved the efficiency of the synthesis of both PGL‐1 and PGL‐tb1 sugars. The process involved the formation of 2‐O‐naphthylmethyl‐α‐rhamnoside and 2‐O‐methyl‐α‐fucoside. Sequential Suzuki–Miyaura coupling using synthetic glycosides, boracyclane, and aryl bromides provided glycolipids related to PGL sugars, and was accomplished with a one‐pot process. Finally, we elucidated the immunosuppressive activities of all these synthetic compounds and found that a phenyl 3‐O‐α‐rhamnosyl‐2‐O‐methyl‐α‐rhamnoside possessing a 6‐(2‐naphthyl)hexyl group exhibited the strongest inhibitory effect.
Live long and prosper: plant–soil feedback, lifespan, and landscape abundance covary
Authors: Kulmatiski Andrew , Beard Karen H. , Norton Jeanette M. , Heavilin Justin E. , Forero Leslie E. , Grenzer Josephine
Published: September 2017

Plant soil feedbacks (PSFs) are thought to be important to plant growth and species coexistence, but most support for these hypotheses is derived from short‐term greenhouse experiments. Here we use a seven‐year, common garden experiment to measurePSFs for seven native and six nonnative species common to the westernUnited States. We use these long‐term, field‐based estimates to test correlations betweenPSFand plant landscape abundance, species origin, functional type, and lifespan. To assess potentialPSFmechanisms, we also measured soil microbial community composition, root biomass, nitrogen cycling, bulk density, penetration resistance, and shear strength. Plant abundance on the landscape and plant lifespan were positively correlated withPSFs, though this effect was due to the relationships for native plants.PSFs were correlated with indices of soil microbial community composition. Soil nutrient and physical traits and root biomass differed among species but were not correlated withPSF. While results must be taken with caution because only 13 species were examined, these species represent most of the dominant plant species in the system. Results suggest that native plant abundance is associated with the ability of long‐lived plants to create positive plant–soil microbe interactions, while short‐lived nonnative plants maintain dominance by avoiding soil‐borne antagonists, increasing nitrogen cycling and dedicating resources to aboveground growth and reproduction rather than to belowground growth. Broadly, results suggest thatPSFs are correlated with a suite of traits that determine plant abundance.
Vegetable Oils Acting as Encapsulated Bioactives and Costabilizers in Miniemulsion Polymerization Reactions
Authors: Bigon Joice P. , Montoro Fabiano E. , Lona Liliane M. F.
Published: September 2017

Vegetable oils with different chemical structures are successfully encapsulated and applied as costabilizers in miniemulsion polymerization reactions. The results are compared to hexadecane, a well‐known costabilizer used for this type of polymerization. The great advantage of using vegetable oils is that besides acting as costabilizers, they are also encapsulated, increasing the application of the nanoparticles. Results show that kinetics tend to be slower with argan oil, due to the higher concentration of double bonds present in the oil. When coconut oil and jojoba oil are used, the kinetic rate kept nearly the same. The different types of costabilizers do not affect the average size of the particle, and are able to keep the miniemulsion stable throughout the reaction. DSC analysis shows a decrease in the glass transition temperature when the vegetable oils are used. However, after a long period of storage, the Tg of the polymers increases. STEM images show the formation of nanoparticles for hexadecane and the vegetable oils. However, the nanocapsule morphology appeares only when coconut oil, jojoba oil, and hexadecane are used, while for argan oil no phase separation can be detected in the polymer particle.

Practical Applications: Miniemulsion polymerization reactions allow the production of polymeric nanoparticles in only one step with high encapsulation efficiency. To obtain a stable miniemulsion, it is necessary the addition of a costabilizer. The vegetable oils are chosen because besides acting as costabilizers the vegetable oils can increase the application of the nanoparticles since they have important characteristics and functionalities.

Miniemulsion polymerization reactions allow the production of polymeric nanoparticles in only one step with high encapsulation efficiency. To obtain a stable miniemulsion, the addition of a costabilizer is necessary. The vegetable oils are chosen because besides acting as costabilizers, the vegetable oils can increase the application of the nanoparticles since they have important characteristics and functionalities. Furthermore, the vegetable oils are biodegradable. In this work, we propose two oils that are not composed of unsaturated fatty acids, unlike many vegetable oils commonly used in the literature.
Quantitative assessment of airway dimensions in young children with cystic fibrosis lung disease using chest computed tomography
Authors: Kuo Wieying , Soffers Thomas , Andrinopoulou Eleni‐Rosalina , Rosenow Tim , Ranganathan Sarath , Turkovic Lidija , Stick Stephen M. , Tiddens Harm A.W.M. ,   on behalf of AREST CF
Published: September 2017

Objective

To evaluate lung disease progression using airway and artery (AA) dimensions on chest CT over 2‐year interval in young CF patients longitudinally and compare to disease controls cross‐sectionally.

Methods

Retrospective analysis of pressure controlled end‐inspiratory CTs, 12 routine baseline (CT1) and follow up (CT2) from AREST CF cohort; 12 disease controls with normal CT. All visible AA‐pairs were measured perpendicular to the airway axis. Inner and outer airway diameters and wall (outer‐inner radius) thickness were divided by adjacent arteries to compute AinA‐, AoutA‐, and AWTA‐ratios, respectively. Differences between CF and control data were assessed using mixed effects models predicting AA‐ratios per segmental generation (SG). Power calculations were performed with 80% power and ɑ = 0.05.

Results

CF, median age CT1 2 years; CT2 3.9 years, 5 males. Controls, median age 2.9 years, 10 males. Total of 4798 AA‐pairs measured. Cross‐sectionally: AinA‐ratio showed no difference between controls and CF CT1 or CT2. AoutA‐ratio was significantly higher in CF CT1 (SG 2‐4) and CT2 (SG 2‐5) compared to controls. AWTA‐ratio was increased for CF CT1 (SG 1‐5) and CT2 (SG 2‐6) compared to controls. CF longitudinally: AinA‐ratio was significantly higher at CT2 compared to CT1. Increase in AoutA‐ratio at CT2 compared to CT1 was visible in SG ≥4. Sample sizes of 21 and 58 would be necessary for 50% and 30% AoutA‐ratio reductions, respectively, between CF CT2 and controls.

Conclusion

AA‐ratio differences were present in young CF patients relative to disease controls. AoutA‐ratio as an objective parameter for bronchiectasis could reduce sample sizes for clinical trials.