/’(H)WETH: VOICE – BREATH – BODY – FORM/S

/’(h)weTH is a collaborative work of visual and sound art produced by R. Armstrong (USA) and Lauren Redhead (UK). The work combines an installation, two video projections, four channel sound, and an optional solo performance part, in order to create an experience that is simultaneously aural and visual, in all of its elements. This article sets out to further explore the main themes of the work, by means of a dialogue between the voices of the two artists. In doing so, it also facilitates a discussion of how /’(h)weTH might contribute to an understanding of the materiality of sound art, and the boundaries between visual art, sound art, and music

Particle acceleration due to shocks in the interplanetary field: High time resolution data and simulation results

Data were examined from two experiments aboard the Explorer 50 (IMP 8) spacecraft. The Johns Hopkins University/Applied Lab Charged Particle Measurement Experiment (CPME) provides 10.12 second resolution ion and electron count rates as well as 5.5 minute or longer averages of the same, with data sampled in the ecliptic plane. The high time resolution of the data allows for an explicit, point by point, merging of the magnetic field and particle data and thus a close examination of the pre- and post-shock conditions and particle fluxes associated with large angle oblique shocks in the interplanetary field. A computer simulation has been developed wherein sample particle trajectories, taken from observed fluxes, are allowed to interact with a planar shock either forward or backward in time. One event, the 1974 Day 312 shock, is examined in detail

An asymptotic solution to a problem in shell stability

Equilibrium configuration for buckled cylindrical shel

Transitions to Nematic states in homogeneous suspensions of high aspect ratio magnetic rods

Isotropic-Nematic and Nematic-Nematic transitions from a homogeneous base state of a suspension of high aspect ratio, rod-like magnetic particles are studied for both Maier-Saupe and the Onsager excluded volume potentials. A combination of classical linear stability and asymptotic analyses provides insight into possible nematic states emanating from both the isotropic and nematic non-polarized equilibrium states. Local analytical results close to critical points in conjunction with global numerical results (Bhandar, 2002) yields a unified picture of the bifurcation diagram and provides a convenient base state to study effects of external orienting fields.Comment: 3 Figure

IMPLICATIONS OF A MARKET FOR CARBON ON TIMBER AND NON-TIMBER VALUES IN AN UNCERTAIN WORLD

Despite considerable interest in the potential for forests to sequester carbon, the impact of carbon management on the provision of timber and non-timber resources has received relatively little attention in the literature. The introduction of value for stored carbon may result in modifications to traditional forest management objectives, generating trade-offs with other forest resources depending on the incentives provided by carbon markets. This paper investigates these issues by examining the impact of a particular form of carbon market on timber and non-timber values in a managed forest. An integrated modeling framework, developed for the incorporation of carbon management into operational timber management modeling tools, is also described. There is still substantial debate over how to properly credit carbon sequestered in forests. To date, there has been little research on how the form of a carbon market will impact the operations and objectives of forestry firms. Alternative market structures could produce very different responses in terms of rotation age, net present value and harvest policy. Here, a specific form of carbon market, the specified level contract, is investigated. Forestry firms are assumed to reach contracts with carbon-seeking agents which "guarantee" that a specified level of carbon stock will be maintained over a defined time period. Optimal forest management decisions are examined by implementing an optimization model for a specific land base in Alberta. The Woodstock forest modeling package is used for optimization. Analysis of trade-offs is based on the work of Armstrong et al. (1999, 2003) which assess non-timber resources using the natural disturbance approach to forest management. The analysis is then expanded to include a more rigorous, and realistic, depiction of carbon and carbon stock changes. Using the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3), carbon yield curves are developed which are integrated directly into the Woodstock forest management ii model. These carbon yields capture dynamics specific to separate biomass and dead organic matter (DOM) carbon pools and are represented for individual forest cover types. Interestingly, the inclusion of DOM carbon generates unexpected relationships between non-timber resources and incentives to sequester carbon. Results show that the presence of co-benefits will depend upon forest cover type, the harvest flow regulation faced by the managing firm and the incentives for timber supply provided by the market. Furthermore, firms that agree to enter contracts for carbon sequestration appear to do so at the expense of a decline in timber supply, with estimates of the opportunity cost of carbon management falling within the range of those found in recent literature.Resource /Energy Economics and Policy,

Analysis and testing of two-dimensional vented Coanda ejectors with asymmetric variable area mixing sections

The analysis of asymmetric, curved (Coanda) ejector flow has been completed using a finite difference technique and a quasi-orthogonal streamline coordinate system. The boundary layer type jet mixing analysis accounts for the effect of streamline curvature in pressure gradients normal to the streamlines and on eddy viscosities. The analysis assured perfect gases, free of pressure discontinuities and flow separation and treated three compound flows of supersonic and subsonic streams. Flow parameters and ejector performance were measured in a vented Coanda flow geometry for the verification of the computer analysis. A primary converging nozzle with a discharge geometry of 0.003175 m x 0.2032 m was supplied with 0.283 cu m/sec of air at about 241.3 KPa absolute stagnation pressure and 82 C stagnation temperature. One mixing section geometry was used with a 0.127 m constant radius Coanda surface. Eight tests were run at spacing between the Coanda surface and primary nozzle 0.01915 m and 0.318 m and at three angles of Coanda turning: 22.5 deg, 45.0 deg, and 75.0 deg. The wall static pressures, the loci of maximum stagnation pressures, and the stagnation pressure profiles agree well between analytical and experimental results

Detailed Morphologicial Studies in Netopirjev rov, Predjama Cave: A Hypogene Segment of Slovenian Cave.

Netopirjev Rov, part of the upper level of Jana near Predjama Cave, is not a former fluvial cave passage but a complex void made up of coalesced, structurally guided elongate cavities with cupolas and a range of speleogens normally associated with hy­pogene caves. These cavities were initially separate and later became integrated by the breakdown of their common walls. The main chamber consists of at least two coalesced voids while an apparent bend, a pseudobend, towards the northern end of Netopirjev Rov results from the breakdown of the com­mon wall near the ends of two adjacent elongate cavities. It is proposed that this section of cave was excavated by the action of water rising from below (per-ascensum speleogenesis), but the nature and source of this water remains unclear

Dating ancient caves and related palaeokarst

 There are few cases of open caves that have been reliably dated to ages greater than 65 Ma. This does not mean that such caves are extremely rare, rather it is difficult to reliably establish that a cave, or palaeokarst related to a cave, is this old. Relative dating methods such as: - regional stratigraphic, lithostratigraphic, biostratigraphic, relative climatic, relative isotopic, morphostratigraphic, and regional geomorphic are very useful. They suffer however from significant difficulties, and their results lack the impact of a crisp numerical date. While many of the methods used to date younger caves will not work over the required age range, some isotopic methods and palaeomagnetic methods have been applied with varying degrees of success. While finding something to date and having it dated is difficult enough, producing the date is rarely the end of the story. The difficult issue is not the date or relative correlation itself, but what the date or correlation means. Demonstrating that caves are ancient seems to rapidly become beset with the old adage that “extraordinary claims require extraordinary proof”. The presence of a well-dated or correlated sediment in a cave does not necessarily mean that the cave is that old or older. Perhaps the dated material was stored somewhere in the surrounding environment and deposited much more recently in the cave. A lava flow in a cave must be demonstrated conclusively to be a flow, not a dyke or a pile of weathered boulders washed into the cave. It must be conclusively shown that dated minerals were precipitated in the cave and not transported from elsewhere. There seems little doubt that in the future more ancient caves, or ancient sections of caves, will be identified and that as a result our perception of the age of caves in general will change. R.A.L. Osborne: Datiranje starih jam in z njimi povezanega paleokrasa Je le nekaj primerov odprtih jam, ki bi imele zanesljivo določeno starost nad 65 milijonov let. To ne pomeni, da so take jame izredno redke, ampak da je težko zanesljivo ugotoviti, da so oziroma paleokras, povezan z njimi, res tako stare. Relativne metode datiranja, kot so regionalno stratigrafsaka, litostratigrafska, biostratigrafska, relativno klimatološka, relativno izotopska, morfostratigrafska in regionalno geomorfološka, so zelo uporabne. Imajo pa pomembne pomanjkljivosti, saj njihovi izsledki ne temelje na jasnih številčnih podatkih. Medtem, ko marsikatera od metod, ki so uporabne za datiranje mlajših jam, ni uporabna za omenjeno starost, pa je bilo uporabljenih več izotopskih in paleomagnetnih metod z različnim uspehom. Težko je najti snov za datiranje in jo datirati, a sama starost še ni konec zgodbe. Težava ni z datiranjem ali s korelacijo, ampak v tem, kaj starost oziroma korelacija pomenita. Dokazovanje, da so jame stare, je hitro odpravljeno s pregovorom »Izredni izsledki zahtevajo izredne dokaze«. Dobro datirani ali korelirani sedimenti v jami še ne pomenijo, da je jama toliko stara ali starejša. Morda je bilo datirano gradivo odloženo nekje v okolici in šele mnogo kasneje preneseno v jamo. Lavin tok v jami mora biti neizpodbitno določen kot lavin tok, ne pa da je dyke ali balvani, prenešeni v jamo. Neizpodbitno mora biti dokazano, da so bili datirani minerali izločeni v jami in ne preneseni od nekod drugod. Nedvomno bo v bodoče spoznanih več starih jam ali njihovih delov in zaradi tega se bo tudi naše pojmovanje o starosti jam v celoti spremenilo.  

Significance and Monitoring

Za vsak program monitoringa v jamah je nujno potreben predhodni popis vseh bistvenih lastnosti nekega procesa. Monitoring ni sam sebi namen, pač pa je del integriranega procesa, osnovanega na bistvenih lastnostih upravljalskega procesa. Nujno je, da vemo, kaj v jami je res pomembno, da poznamo pogoje, v katerih lahko to pomembnost ohranimo in, da so tako ohranjeni pogoji celota vseh pomembnih dejavnikov. Na primer, če ne poznamo mehanizma odlaganja blatnih sedimentov, potem monitoring stanja kapnikov ne bo preprečil ponovnega odlaganja blata, ki smo ga sicer odstranili s pranjem pod visokim pritiskom. Podobno nima nobenega smisla merjenje temperature, če je prah glavna gro‘nja pomembnim elementom. Edini način, po katerem spoznamo, da je monitoring uspešen je ta, da merimo značilnosti in celovitost pomembnih elementov. Sicer lahko zberemo veliko pomembnih podatkov, najpomembnejše oblike pa nam medtem propadejo. Zato se mora monitoring nanašati na nujne okoliščine, pri katerih še lahko ohranimo bistvene značilnosti ter na sprotno stanje in celovitost pomembnih značilnosti.An inventory survey followed by a significance assessment process, are essential precursors to any cave monitoring program. Monitoring must not be seen as an end in itself, but as part of an integrated, significance- based management process. It is essential to know what is significant, the conditions necessary to maintain its significance and that the condition and integrity of significant elements are being maintained. For instance, if the significance of a mud deposit is not known, monitoring the condition of speleothems will not stop the mud deposit from being destroyed by high-pressure water cleaning. Similarly, there is little point in monitoring temperature if dust is the main threat to the significant elements. The only way to know that monitoring of environmental conditions is effective is to monitor the ongoing condition and integrity of the significant elements themselves. Without this, lots of interesting data could be collected while the most important features of the cave are lost. Monitoring should therefore address the conditions necessary for the maintenance of significance and the ongoing condition and integrity of significant elements

Cave Turbidites

Turbidites are uncommon in caves, but are more common as palaeokarst deposits. Marine carbonate turbidites, called cay­manites, are the most common cave and palaeokarst turbidites, but marine non-carbonate turbidites, freshwater carbonate turbidites and freshwater non-carbonate turbidites are also de­posited in caves and preserved in palaeokarst sequences. One of the most complex sequences of cave turbidites occurs in the Wellington Caves Phosphate Mine in Australia. Cave turbidites form in ponded water in caves and may be triggered by floods and highintensity rain events. While caymanites are most likely to form during marine transgressions, they can be emplaced by tsunami. Freshwater cave turbidites are most likely to form in flooded hypogene caves located in the seasonally wet tropics and in areas withirregular highintensity rainfall events