Error estimates for a fully discrete spectral scheme for a class of nonlinear, nonlocal dispersive wave equations

We analyze a fully discrete spectral method for the numerical solution of the initial- and periodic boundary-value problem for two nonlinear, nonlocal, dispersive wave equations, the Benjamin–Ono and the Intermediate Long Wave equations. The equations are discretized in space by the standard Fourier–Galerkin spectral method and in time by the explicit leap-frog scheme. For the resulting fully discrete, conditionally stable scheme we prove an L2-error bound of spectral accuracy in space and of second-order accuracy in time.

Laboratory measurements of the water vapor continuum in the 1200–8000 cm−1 region between 293 K and 351 K

Laboratory Fourier transform spectroscopy of pure water vapor and water vapor mixed with air has been conducted between 1200 and 8000 cm−1 and at temperatures between 293 and 351 K with the purpose of detecting and characterizing the water vapor continuum. The spectral features of the continuum within the major water absorption bands are presented and compared where possible to those from previous experimental studies and to the commonly used MT_CKD and CKD models. It was observed that in the main, both models adequately capture the general spectral form of the continuum; however, there were a number of exceptions. Overall, there is no evidence to indicate that MT_CKD is an improvement upon the older CKD model in these spectral regions. There was generally good agreement between our results and those of other experimental investigators. The general mathematical forms of the self-continuum temperature dependence, given by both Roberts et al. (1976) and CKD/MT_CKD, fit well to the experimental continuum in these spectral regions. However, the range of temperatures over which we made measurements is not sufficient to discriminate between these two forms or to exclude the possibility of other forms of temperature dependence being more appropriate. At the same time, the actual parameters currently used in CKD/MT_CKD to describe the temperature dependence in many spectral regions cannot reproduce the observed strong spectral variation in the temperature dependence. It has not been possible to make definitive conclusions about the magnitude of the continuum absorption in the far wings of the absorption bands investigated here.

Facebook faith - social networking in a faith based community

This paper views the increasing social networking as an efficient emerging ministry to the moveable generation. Through social network such as Facebook, ministry from a pastoral perspective can become more authentic and meaningful. Ministry is relational. Social Networking sites provide a strong platform to being part in other people’s life. Social networking and living online builds community beyond geographical boarders. Young adults and youths digital identity often reflects their faith, this is supported by research which suggests a practice of more openness to share and expose private issues online. Spiritual and religious views are freely shared, creating sacred spaces in the midst of life practising a holistic faith identity in a secular community. Providing a strong platform for information flow, Social Network is attractive in a postmodern society where inviting people to join in events are perceived as non threatening, making church community events transparent and available to people who do not attend church, inviting spiritual friendships and relationships. Social Networking strengthens relationship in a non hierarchical manner and invites the minister into lives where there previously would have been barriers, engaging in prayer and bible study as well as pastoral care through social networking, thus relationships deepens via social networking making people real. It has been observed that, although community building happens on the net, church affiliation loyalty remains to the local community. Therefore presence ministry though social networks emerges as a core form of ministry, where relations to youth who move from local church to university campuses are kept alive. The asynchronous nature of communication within social networking eases the minister in her work. The minister is able to engage with many individuals at the same time. Before the minister could visit one person at a time, now she visits 5-6 individuals at any given time. Therefore social networking not only increases the quality of the work, but also empowers the minister to be more efficient.

Water vapour continuum absorption in near-infrared windows derived from laboratory measurements

In most near-infrared atmospheric windows, absorption of solar radiation is dominated by the water vapor self-continuum and yet there is a paucity of measurements in these windows. We report new laboratory measurements of the self-continuum absorption at temperatures between 293 and 472 K and pressures from 0.015 to 5 atm in four near-infrared windows between 1 and 4 m (10000-2500 cm-1); the measurements are made over a wider range of wavenumber, temperatures and pressures than any previous measurements. They show that the self-continuum in these windows is typically one order of magnitude stronger than given in representations of the continuum widely used in climate and weather prediction models. These results are also not consistent with current theories attributing the self continuum within windows to the far-wings of strong spectral lines in the nearby water vapor absorption bands; we suggest that they are more consistent with water dimers being the major contributor to the continuum. The calculated global-average clear-sky atmospheric absorption of solar radiation is increased by 0.75 W/m2 (which is about 1% of the total clear-sky absorption) by using these new measurements as compared to calculations with the MT_CKD-2.5 self-continuum model.

Sub-irrigation of Petunia: benefits in dry summers

With the increasing frequency and magnitude of warmer days during the summer in the UK, bedding plants which were a traditional part of the urban green landscape are perceived as unsustainable and water-demanding. During recent summers when bans on irrigation have been imposed, use and sales of bedding plants have dropped dramatically having a negative financial impact on the nursery industry. Retaining bedding species as a feature in public and even private spaces in future may be conditional on them being managed in a manner that minimises their water use. Using Petunia x hybrida ‘Hurrah White’ we aimed to discover which irrigation approach was the most efficient for maintaining plants’ ornamental quality (flower numbers, size and longevity), shoot and root growth under water deficit and periods of complete water withdrawal. Plants were grown from plugs for 51 days in wooden rhizotrons (0.35 m (h) x 0.1 m (w) x 0.065 m (d)); the rhizotrons’ front comprised clear Perspex which enabled us to monitor root growth closely. Irrigation treatments were: 1. watering with the amount which constitutes 50% of container capacity by conventional surface drip-irrigation (‘50% TOP’); 2. 50% as sub-irrigation at 10 cm depth (‘50% SUB’); 3. ‘split’ irrigation: 25% as surface drip- and 25% as sub-irrigation at 15 cm depth (‘25/25 SPLIT’); 4. 25% as conventional surface drip-irrigation (‘25% TOP’). Plants were irrigated daily at 18:00 apart from days 34-36 (inclusive) when water was withdrawn for all the treatments. Plants in ‘50% SUB’ had the most flowers and their size was comparable to that of ‘50% TOP’. Differences between treatments in other ‘quality’ parameters (height, shoot number) were biologically small. There was less root growth at deeper soil surface levels for ‘50% TOP’ which indicated that irrigation methods like ‘50% SUB’ and ‘25/25 SPLIT’ and stronger water deficits encouraged deeper root growth. It is suggested that sub-irrigation at 10 cm depth with water amounts of 50% container capacity would result in the most root growth with the maximum flowering for Petunia. Leaf stomatal conductance appeared to be most sensitive to the changes in substrate moisture content in the deepest part of the soil profile, where most roots were situated.

Spectral analysis of diffusions with jump boundary

In this paper we consider one-dimensional diffusions with constant coefficients in a finite interval with jump boundary and a certain deterministic jump distribution. We use coupling methods in order to identify the spectral gap in the case of a large drift and prove that there is a threshold drift above which the bottom of the spectrum no longer depends on the drift. As a corollary to our result we are able to answer two questions concerning elliptic eigenvalue problems with non-local boundary conditions formulated previously by Iddo Ben-Ari and Ross Pinsky.

Complexity theory and planning: examining 'fractals' for organising policy domains in planning practice

This article examines selected methodological insights that complexity theory might provide for planning. In particular, it focuses on the concept of fractals and, through this concept, how ways of organising policy domains across scales might have particular causal impacts. The aim of this article is therefore twofold: (a) to position complexity theory within social science through a ‘generalised discourse’, thereby orienting it to particular ontological and epistemological biases and (b) to reintroduce a comparatively new concept – fractals – from complexity theory in a way that is consistent with the ontological and epistemological biases argued for, and expand on the contribution that this might make to planning. Complexity theory is theoretically positioned as a neo-systems theory with reasons elaborated. Fractal systems from complexity theory are systems that exhibit self-similarity across scales. This concept (as previously introduced by the author in ‘Fractal spaces in planning and governance’) is further developed in this article to (a) illustrate the ontological and epistemological claims for complexity theory, and to (b) draw attention to ways of organising policy systems across scales to emphasise certain characteristics of the systems – certain distinctions. These distinctions when repeated across scales reinforce associated processes/values/end goals resulting in particular policy outcomes. Finally, empirical insights from two case studies in two different policy domains are presented and compared to illustrate the workings of fractals in planning practice.

Wave activity in the tropical tropopause layer in seven reanalysis and four chemistry climate model data sets

Sub-seasonal variability including equatorial waves significantly influence the dehydration and transport processes in the tropical tropopause layer (TTL). This study investigates the wave activity in the TTL in 7 reanalysis data sets (RAs; NCEP1, NCEP2, ERA40, ERA-Interim, JRA25, MERRA, and CFSR) and 4 chemistry climate models (CCMs; CCSRNIES, CMAM, MRI, and WACCM) using the zonal wave number-frequency spectral analysis method with equatorially symmetric-antisymmetric decomposition. Analyses are made for temperature and horizontal winds at 100 hPa in the RAs and CCMs and for outgoing longwave radiation (OLR), which is a proxy for convective activity that generates tropopause-level disturbances, in satellite data and the CCMs. Particular focus is placed on equatorial Kelvin waves, mixed Rossby-gravity (MRG) waves, and the Madden-Julian Oscillation (MJO). The wave activity is defined as the variance, i.e., the power spectral density integrated in a particular zonal wave number-frequency region. It is found that the TTL wave activities show significant difference among the RAs, ranging from ∼0.7 (for NCEP1 and NCEP2) to ∼1.4 (for ERA-Interim, MERRA, and CFSR) with respect to the averages from the RAs. The TTL activities in the CCMs lie generally within the range of those in the RAs, with a few exceptions. However, the spectral features in OLR for all the CCMs are very different from those in the observations, and the OLR wave activities are too low for CCSRNIES, CMAM, and MRI. It is concluded that the broad range of wave activity found in the different RAs decreases our confidence in their validity and in particular their value for validation of CCM performance in the TTL, thereby limiting our quantitative understanding of the dehydration and transport processes in the TTL.

Applications of micromorphology to understanding activity areas and site formation processes in experimental hut floors

Experimental buildings at Butser Ancient Farm and St. Fagans (UK) and Lejre (Denmark) were sampled to investigate micromorphology of known activity areas, to contribute to our understanding of the internal use of space in excavated buildings and formation processes of house floor deposits. The experimental buildings provided important information relating to activity residues and sediments over the 16 years that the buildings were in use. Specifically, these results contribute to our understanding of the routes and cycles for transportation of materials in occupation contexts, which can be used to inform archaeological studies. It has been possible to identify internal ‘hot spots’ within the buildings for the deposition of activity residues and for the formation of specific deposit types. Analysis also highlighted postdepositional alterations occurring in internal occupation deposits, which has provided a means of identifying roofed and unroofed spaces in the archaeological record.

A review of the performance of different ventilation and airflow distribution systems in buildings

The objective of this article is to review the scientific literature on airflow distribution systems and ventilation effectiveness to identify and assess the most suitable room air distribution methods for various spaces. In this study, different ventilation systems are classified according to specific requirements and assessment procedures. This study shows that eight ventilation methods have been employed in the built environment for different purposes and tasks. The investigation shows that numerous studies have been carried out on ventilation effectiveness but few studies have been done regarding other aspects of air distribution. Amongst existing types of ventilation systems, the performance of each ventilation methods varies from one case to another due to different usages of the ventilation system in a room and the different assessment indices used. This review shows that the assessment of ventilation effectiveness or efficiency should be determined according to each task of the ventilation system, such as removal of heat, removal of pollutant, supply fresh air to the breathing zone or protecting the occupant from cross infection. The analysis results form a basic framework regarding the application of airflow distribution for the benefit of designers, architects, engineers, installers and building owners.

Derivation of an urban materials spectral library through emittance and reflectance spectroscopy

Recent advances in thermal infrared remote sensing include the increased availability of airborne hyperspectral imagers (such as the Hyperspectral Thermal Emission Spectrometer, HyTES, or the Telops HyperCam and the Specim aisaOWL), and it is planned that an increased number spectral bands in the long-wave infrared (LWIR) region will soon be measured from space at reasonably high spatial resolution (by imagers such as HyspIRI). Detailed LWIR emissivity spectra are required to best interpret the observations from such systems. This includes the highly heterogeneous urban environment, whose construction materials are not yet particularly well represented in spectral libraries. Here, we present a new online spectral library of urban construction materials including LWIR emissivity spectra of 74 samples of impervious surfaces derived using measurements made by a portable Fourier Transform InfraRed (FTIR) spectrometer. FTIR emissivity measurements need to be carefully made, else they are prone to a series of errors relating to instrumental setup and radiometric calibration, which here relies on external blackbody sources. The performance of the laboratory-based emissivity measurement approach applied here, that in future can also be deployed in the field (e.g. to examine urban materials in situ), is evaluated herein. Our spectral library also contains matching short-wave (VIS–SWIR) reflectance spectra observed for each urban sample. This allows us to examine which characteristic (LWIR and) spectral signatures may in future best allow for the identification and discrimination of the various urban construction materials, that often overlap with respect to their chemical/mineralogical constituents. Hyperspectral or even strongly multi-spectral LWIR information appears especially useful, given that many urban materials are composed of minerals exhibiting notable reststrahlen/absorption effects in this spectral region. The final spectra and interpretations are included in the London Urban Micromet data Archive (LUMA; http://LondonClimate.info/LUMA/SLUM.html).

Complex extreme learning machine applications in terahertz pulsed signals feature sets

This paper presents a novel approach to the automatic classification of very large data sets composed of terahertz pulse transient signals, highlighting their potential use in biochemical, biomedical, pharmaceutical and security applications. Two different types of THz spectra are considered in the classification process. Firstly a binary classification study of poly-A and poly-C ribonucleic acid samples is performed. This is then contrasted with a difficult multi-class classification problem of spectra from six different powder samples that although have fairly indistinguishable features in the optical spectrum, they also possess a few discernable spectral features in the terahertz part of the spectrum. Classification is performed using a complex-valued extreme learning machine algorithm that takes into account features in both the amplitude as well as the phase of the recorded spectra. Classification speed and accuracy are contrasted with that achieved using a support vector machine classifier. The study systematically compares the classifier performance achieved after adopting different Gaussian kernels when separating amplitude and phase signatures. The two signatures are presented as feature vectors for both training and testing purposes. The study confirms the utility of complex-valued extreme learning machine algorithms for classification of the very large data sets generated with current terahertz imaging spectrometers. The classifier can take into consideration heterogeneous layers within an object as would be required within a tomographic setting and is sufficiently robust to detect patterns hidden inside noisy terahertz data sets. The proposed study opens up the opportunity for the establishment of complex-valued extreme learning machine algorithms as new chemometric tools that will assist the wider proliferation of terahertz sensing technology for chemical sensing, quality control, security screening and clinic diagnosis. Furthermore, the proposed algorithm should also be very useful in other applications requiring the classification of very large datasets.

Toeplitz operators on Dirichlet-Besov spaces

We study Toeplitz operators on the Besov spaces in the case of the open unit disk. We prove that a symbol satisfying a weak Lipschitz type condition induces a bounded Toeplitz operator. Such symbols do not need to be bounded functions or have continuous extensions to the boundary of the open unit disk. We discuss the problem of the existence of nontrivial compact Toeplitz operators, and also consider Fredholm properties and prove an index formula.

Histologic Evaluation of the Buccal and Lingual Bone Plates in Anterior Dog Teeth: Possible Influence on Implant Dentistry

Background: Recent studies in animals have shown pronounced resorption of buccal bone plate after immediate implantation. The sectioning of experimental material for histologic evaluation of the bone plates could provide valuable information about the possible effect of bone exposure in periodontal and implant surgeries. Methods: Twenty-four incisors were collected from dogs. After decalcification, the blocks were immersed in paraffin and bucco-lingual histologic sections were examined under light microscope. Some sections were reserved for immunohistochemical analysis. Results: The bone density, the width of the bone plates, and the percentage of vessels presented in the periodontal ligament and periosteum were analyzed in the buccal and lingual bone plates, which were divided corono-apically into thirds. The buccal bone plates showed statistically higher bone density compared to the lingual bone plates in the coronal thirds. The width of both bone plates increased from the coronal to the apical third, but all the buccal thirds were significantly thinner compared to the lingual thirds. No statistically significant differences were found between the bone plates for the percentage of area occupied by the blood vessels in the periodontal ligament or periosteum. Conclusion: It is reasonable to conclude that the higher bone density, represented by the lower number of marrow spaces, in association with the thinner aspect of the buccal bone plates made them more fragile to absorb compared to the lingual bone plates, especially during mucoperiosteal procedures. J Periodontol 2017;82:872-877.