Classroom acoustics: the national acoustic standard

This paper discusses the variables affecting classroom acoustics and a case study examination of some local classrooms. Classrooms were measured against proposed American National Standards Institute (ANSI) standards and treatment options for improving acoustics are suggested.

Made in “Polish village” – modern ethno-design vs. traditional culture of Polish countryside

Tradycyjna polska wieś – kolorowa, wesoła, zintegrowana z naturą i rządząca się swoimi prawami to zbiorowy mit, odległy w czasie. To klasyczny temat wielu poszukiwań etnografi cznych – terenowych, naukowych opracowań i porównań. We współczesnym świecie mamy do czynienia jedynie z wybranymi elementami – tradycjami jeszcze żywymi lub przetworzonymi i dostosowanymi do wymogów współczesnego odbiorcy – turysty, ale także artysty i projektanta. Obecne zainteresowanie polską sztuką ludową i rzemiosłem to kolejna fala mody folkowej. Ten ogólnoeuropejski trend, poszukujący w kulturze egalitarnej natchnienia i inspiracji swój początek bierze w I połowie XIX wieku. W polskiej sztuce dekoracyjnej (wzornictwie przemysłowym) także nastąpił powrót do źródeł, a w ludowości i wiejskości doszukiwano się narodowego ducha, inspiracją dla polskich artystów był angielski Ruch Arts and Craft, a w ich projektach widoczne były echa fi lozofi i Johna Ruskina oraz Williama Morrisa m. in. odrzucających masową produkcję, mającą wg nich zły wpływ na jakość produkowanych przedmiotów, jednocześnie na piedestał wynoszących umiejętności rękodzielnicze i rzemieślnicze. Po okresie PRLu utożsamianym głównie z funkcjonowaniem Cepelii i sprowadzeniem produktów inspirowanych ludowością do roli masowych dekoracji, stanowiących często synonim kiczu, powróciła moda na polskie rękodzieło, tradycyjną sztukę ludową oraz na inspiracje wypływające z obserwowania wiejskiego stylu życia. Współczesne poszukiwania polskich twórców w obszarze tworzących w ramach nurtu zwanego etnodizajnem przebiegają dwutorowo. Z jednej strony to inspiracja tylko przejawami ludowości, jej konkretnymi wytworami, które stanowią głównie dekorację dla współczesnych rozwiązań formalnych i technologicznych. Jednak coraz silniejszy jest drugi nurt,starający się wniknąć głębiej, którego celem jest zrozumienie istoty tradycyjnej kultury ludowej polskiej wsi. To inspiracja wiejskim stylem życia, wraz z jego zaletami i wadami, to wreszcie inspiracja zmieniającym się krajobrazem kulturowym i poszukiwanie nowych rozwiązań, dzięki którym odbiorca zbliży się do natury. Projekty zaliczane do nurtu etnodizajnu cechuje przede wszystkim różnorodność wykorzystanych materiałów (tradycyjnych i nowoczesnych), sposób ich przetworzenia, zachowanie pierwotnej funkcji lub nadanie nowej. Większość tych projektów sytuuje się też w nurcie eko-artu, sztuki nawiązującej do natury, z wykorzystaniem ekologicznych materiałów. Jest więc etnodizajn XXI kontynuacją ideologii stworzonej już w wieku XIX – przeciwstawieniem dla przemysłu, technicyzacji i umasowienia. A dla współczesnego człowieka – miejskiego – może być etnodizajn powrotem do źródeł.

Running Climate Models On The NERC Cluster Grid Using G-Rex

Compute grids are used widely in many areas of environmental science, but there has been limited uptake of grid computing by the climate modelling community, partly because the characteristics of many climate models make them difficult to use with popular grid middleware systems. In particular, climate models usually produce large volumes of output data, and running them usually involves complicated workflows implemented as shell scripts. For example, NEMO (Smith et al. 2008) is a state-of-the-art ocean model that is used currently for operational ocean forecasting in France, and will soon be used in the UK for both ocean forecasting and climate modelling. On a typical modern cluster, a particular one year global ocean simulation at 1-degree resolution takes about three hours when running on 40 processors, and produces roughly 20 GB of output as 50000 separate files. 50-year simulations are common, during which the model is resubmitted as a new job after each year. Running NEMO relies on a set of complicated shell scripts and command utilities for data pre-processing and post-processing prior to job resubmission. Grid Remote Execution (G-Rex) is a pure Java grid middleware system that allows scientific applications to be deployed as Web services on remote computer systems, and then launched and controlled as if they are running on the user's own computer. Although G-Rex is general purpose middleware it has two key features that make it particularly suitable for remote execution of climate models: (1) Output from the model is transferred back to the user while the run is in progress to prevent it from accumulating on the remote system and to allow the user to monitor the model; (2) The client component is a command-line program that can easily be incorporated into existing model work-flow scripts. G-Rex has a REST (Fielding, 2000) architectural style, which allows client programs to be very simple and lightweight and allows users to interact with model runs using only a basic HTTP client (such as a Web browser or the curl utility) if they wish. This design also allows for new client interfaces to be developed in other programming languages with relatively little effort. The G-Rex server is a standard Web application that runs inside a servlet container such as Apache Tomcat and is therefore easy to install and maintain by system administrators. G-Rex is employed as the middleware for the NERC1 Cluster Grid, a small grid of HPC2 clusters belonging to collaborating NERC research institutes. Currently the NEMO (Smith et al. 2008) and POLCOMS (Holt et al, 2008) ocean models are installed, and there are plans to install the Hadley Centre’s HadCM3 model for use in the decadal climate prediction project GCEP (Haines et al., 2008). The science projects involving NEMO on the Grid have a particular focus on data assimilation (Smith et al. 2008), a technique that involves constraining model simulations with observations. The POLCOMS model will play an important part in the GCOMS project (Holt et al, 2008), which aims to simulate the world’s coastal oceans. A typical use of G-Rex by a scientist to run a climate model on the NERC Cluster Grid proceeds as follows :(1) The scientist prepares input files on his or her local machine. (2) Using information provided by the Grid’s Ganglia3 monitoring system, the scientist selects an appropriate compute resource. (3) The scientist runs the relevant workflow script on his or her local machine. This is unmodified except that calls to run the model (e.g. with “mpirun”) are simply replaced with calls to "GRexRun" (4) The G-Rex middleware automatically handles the uploading of input files to the remote resource, and the downloading of output files back to the user, including their deletion from the remote system, during the run. (5) The scientist monitors the output files, using familiar analysis and visualization tools on his or her own local machine. G-Rex is well suited to climate modelling because it addresses many of the middleware usability issues that have led to limited uptake of grid computing by climate scientists. It is a lightweight, low-impact and easy-to-install solution that is currently designed for use in relatively small grids such as the NERC Cluster Grid. A current topic of research is the use of G-Rex as an easy-to-use front-end to larger-scale Grid resources such as the UK National Grid service.

Mass and size distribution measurement of particulates from a gas turbine combustor using modern mobility analyzer and particle sizer

SMPS and DMS500 analysers were used to measure particulate size distributions in the exhaust of a fully annular aero gas turbine engine at two operating conditions to compare and analyse sources of discrepancy. A number of different dilution ratio values were utilised for the comparative analysis, and a Dekati hot diluter operating at a temperature of 623°K was also utilised to remove volatile PM prior to measurements being made. Additional work focused on observing the effect of varying the sample line temperatures to ascertain the impact. Explanations are offered for most of the trends observed, although a new, repeatable event identified in the range from 417°K to 423°K – where there was a three order of magnitude increase in the nucleation mode of the sample – requires further study.

Seasonality of modern pollen and sediment deposition in an estuarine context: the Severn Estuary Levels, southwest England

Recent sedimentological and palynological research on subfossil Holocene banded sediments from the Severn Estuary Levels suggested seasonality of deposition, registered by variations in mineral grain-size and pollen assemblages between different parts of the bands. Here we provide data that strengthen this interpretation from sampling of modern sediments and pollen deposition on an active mudflat and saltmarsh on the margin of the Severn Estuary, and comparison with a vegetation survey and contemporary records of climate, river and tidal regimes. The results of grain-size analysis indicate deposition of comparatively coarse-grained silts during the relatively cool and windy conditions of winter and comparatively fine-grained sediments during relatively warm and calm summer months. Pollen analysis demonstrates the significance of long-term storage of pollen grains and fern spores in the estuarine waterbody, superimposed on which seasonal variations in pollen inputs from local and regional vegetation remain detectable. Copyright (C) 2007 John Wiley & Sons, Ltd.

Seasonality of delta C-13 and C/N ratios in modern and mid-holocene sediments in the Severn Estuary levels, SW Britain

Bulk organic VC and C/N ratios from mid-Holocene salt-marsh deposits with sedimentary banding reveal subtle but significant differences between coarse- and fine-grained deposits. These are consistent with findings from seasonally sampled modern silts, and with the interpretation, on physical and palynological grounds, of the fine-grained and coarse-grained components as warm-season and cold-season deposits, respectively. The control is considered to be seasonal variations in the character of the organic matter supplied.

Evolution of the modern Nile delta promontories: development of accretional features during shoreline retreat

The active accretional features that have developed along the modern Nile Delta promontories during shoreline retreat are analysed using topographic maps, remote imagery, ground and hydrographic surveys, together providing 15 time-slice maps (1922-2000) at Rosetta and 14 time-slice maps (1909-2000) at Damietta. Small double sandy spits developed and persisted at Rosetta between 1986 and 1991. At Damietta, a much larger single spit, 9 km long, formed approximately east of the mouth of the Damietta Nile branch between 1955 and 1972, although its source has now been depleted. Both the Rosetta and Damietta inlets are associated with submerged mouth bars that accumulated prior to the damming of the Nile, but that continue to contribute to local sedimentation problems, particularly at Rosetta. The development of the active accretional features along the Nile promontories reflects a combination of factors including sediment availability, transport pathways from source areas, a decrease in the magnitude of Nile flood discharges, as well as the impact of protective structures at the river mouths.