Journal articles on the topic 'Blanket Creet'

China Low Activation Martensitic (CLAM) steel has been chosen as the structural material for China ITER Test Blanket Module (TBM). Creep-rupture and fatigue damage caused by high temperature and pulse stresses are two key issues for the final application of CLAM steel in China ITER TBM. In this paper, the research and development progress of the creep and fatigue behaviors of CLAM steel were presented. These results showed that CLAM steel possessed good high temperature mechanical properties.

Construction of earthen dams has developed quickly to access water and electricity. The earthquake phenomena can generate cracks at the crest, and transferred them to the structural body. It has occurred during the interaction between structure and reservoir. In this context, some reinforcement techniques have experienced according to the literature. They have included a perpendicular drain, prefabricated vertical drain, Geosynthetic in some layers within the structure, Pile, injection and cut off wall system on the dam foundation. Most of them controlled this aspect costly. The Finite-element method has applied via plane strain aspect using the ANSYS13. This paper evaluated effects of using blanket layer between a short homogenized earthen dam and weak foundation on the dynamic behavior throughout the seismic process. As a result, clay soil in the blanket layer with a modulus elasticity ratio equal to 2.50 between it, and loose sand of foundation has indicated the optimal approach. It has revealed that, this method can be changed the situation of the minimum and maximum value of shear stress when it has located in the middle of the foundation without the blanket layer at the end of vibration.

This paper insight about reasons of disappointment in distribution transformers. It has been suggested that crawl may be a noteworthy purpose behind such disappointments. The impact of anxiety, temperature, and material on unfaltering state killjoy rate on aluminum and copper wires (utilized as a part of 25 KVA distribution transformers) have been introduced. Proposed study affirms that the disappointment rate of aluminum wound DTs is higher than the disappointment rate of copper injury DTs in force insufficient ranges and poor conveyance systems. The higher disappointment rate of aluminum wound DTs has been credited to the lifted enduring state wet blanket rate of the aluminum wire than copper wire.

This study discusses the result of creep-fatigue tests of a high-chromium steel, F82H which was designed as blanket structural materials of nuclear fusion reactor, carried out at room temperature to 823K in air. Strain paths applied were a push-pull loading and a circle loading in which normal and shear strain have 90 degree phase difference. The holding times used were 180 s and 600 s. Moreover, an evaluation of failure life by taking into account intensities of creep and non-proportionality is discussed based on both the life evaluation proposed by Itoh, et al and method of modified universal slopes. Availability of the equation for the life evaluation was confirmed by comparison with conventional universal slope method.

Reduced activation ferritic/martensitic (RAFM) steels are candidate materials for the test blanket modules of ITER. Several degradation mechanisms such as thermal fatigue, low cycle fatigue, creep fatigue interaction, creep, irradiation hardening, swelling and phase instability associated irradiation embrittlement must be understood to estimate the component lifetime. The current work focuses on the effect of tungsten and tantalum on low cycle fatigue (LCF) and creep-fatigue interaction (CFI) behavior of four RAFM steels with varying W and Ta contents. Total strain controlled LCF experiments were performed under various strain amplitudes in the range +0.25% to +1% and temperatures (300 K to 873 K) in air at a constant strain rate of 3×10-3s-1 using a servo hydraulic fatigue testing system. CFI experiments were carried out at total strain amplitude of +0.6% and by applying strain hold of different durations (10 min and 30 min) in peak tension and peak compression. Both LCF and CFI life of the RAFM steels improved with the increase in tungsten and tantalum contents. Based on the amount of softening during continuous cycling, tungsten content was optimized at 1.4 wt. % and the tantalum content at 0.06 wt%. Stress relaxation obtained during creep-fatigue interaction studies showed close relation with the chemical composition of the RAFM steels. Other damaging parameters influencing fatigue life were dynamic strain ageing (DSA) occurring in the intermediate temperature regime and oxidation at elevated temperatures. Keywords: RAFM steel, low cycle fatigue, dynamic strain ageing, creep-fatigue interaction, oxidation

This paper describes the stress analysis performed to assess structural adequacy of the Clinch River Breeder Reactor (CRBR) core removable shield assemblies. Removable shield assemblies are located in the peripheral region of the core (between blanket assemblies and the fixed radial shield), and are subjected to severe cross-sectional thermal gradients and seismic loads requiring a relatively complex duct load pad design. For cost-effectiveness, the analysis was conducted in two stages. First, an elasto-plastic seismic stress analysis was performed using a detailed nonlinear finite element model (with gaps) of the load pad configuration. Next, in order to determine the total strain accumulation and the creep-fatigue damage the maximum seismic stresses combined with the “worst” thermal stresses from a single assembly model were used to perform a simplified inelastic analysis using two sets of material properties to bound the changing material conditions during reactor operation. This work demonstrated the necessity and applicability of the two simplified analysis techniques in elevated temperature structural design, i.e., the treatment of time-dependent degradation of material properties due to temperature and nuclear irradiation, and the use of time-independent finite element stress analysis results to perform a simplified creep-fatigue analysis.

Hillock formation, a stress-induced diffusional relaxation process, was studied in sputter-deposited Al films. The grain sizes in these films were small compared to those in other sputter-deposited Al films, and impurities (O, Ti, W) were incorporated during the preparation of the films. Stress and hardness measurements both indicate that the Al films were strengthened by the small grain size and incorporated impurities. We observed a new type of hillock in these Al thin films after annealing for 2 h at 450 °C in a forming gas ambient. The hillocks were composed of large Al grains created between the substrate and the original Al film with its columnar grain structure, apparently by diffusion from the surrounding area. By modifying the boundary conditions of Chaudhari's hillock formation model [P. Chaudhari, J. Appl. Phy. 45, 4339 (1974)], we have created a new model that can describe the experimentally observed hillocks. Our model seems to explain the experimentally observed abnormal hillock formation and may be applied to other types of hillock formation using different creep laws.

The Georgina Basin is an intracratonic basin on the central-northern Australian craton. Its southern portion includes a highly prospective Middle Cambrian petroleum system which remains largely unexplored. A plethora of stratigraphic names plagued previous exploration but the lithostratigraphy has now been rationalised using previously unpublished electric-log correlations and seismic and core data.Neoproterozoic and Lower Palaeozoic sedimentary rocks of the southern portion of the basin cover an area of 100,000 km2 and thicken into two main depocentres, the Toko and Dulcie Synclines. In and between these depocentres, a Middle Cambrian carbonate succession comprising Thorntonia Limestone and Arthur Creek Formation provides a prospective reservoir-source/seal couplet extending over 80,000 km2. The lower Arthur Creek Formation includes world class microbial source rocks recording total organic carbon (TOC) values of up to 16% and hydrocarbon yields up to 50 kg/tonne. This blanket source/seal unconformably overlies sheetlike, platform dolostone of the Thorntonia Limestone which provides the prime target reservoir. Intra- Arthur Creek high-permeability grainstone shoals are important secondary targets.In the Toko Syncline, Middle Cambrian source rocks entered the oil window during the Ordovician, corresponding to major sediment loading at this time. The gas window was reached prior to structuring associated with the Middle Devonian-Early Carboniferous Alice Springs Orogeny, and source rocks today lie in the dry gas window. In contrast, high-temperature basement granites have resulted in overmaturity of the Arthur Creek Formation in the Dulcie Syncline area. On platform areas adjacent to both these depocentres source rocks reached peak oil generation shortly after the Alice Springs Orogeny; numerous structural leads have been identified in these areas. In addition, an important stratigraphic play occurs in the Late Cambrian Arrinthrunga Formation (Hagen Member) on the southwestern margin of the basin. Key elements of the play are the pinchout of porous oil-stained, vuggy dolostone onto basement where top seal is provided by massive anhydrite while underlying Arthur Creek Formation shale provides a potential source.

The reliability of integrated-circuit wiring depends strongly on the development and relaxation of stresses that promote void and hillock formation. In this paper an analysis based on existing models of creep is presented that predicts the stresses developed in thin blanket films of copper on Si wafers subjected to thermal cycling. The results are portrayed on deformation-mechanism maps that identify the dominant mechanisms expected to operate during thermal cycling. These predictions are compared with temperature-ramped and isothermal stress measurements for a 1 μm-thick sputtered Cu film in the temperature range 25–450 °C. The models successfully predict both the rate of stress relaxation when the film is held at a constant temperature and the stress-temperature hysteresis generated during thermal cycling. For 1 μm-thick Cu films cycled in the temperature range 25–450 °C, the deformation maps indicate that grain-boundary diffusion controls the stress relief at higher temperatures (>300 °C) when only a low stress can be sustained in the films, power-law creep is important at intermediate temperatures and determines the maximum compressive stress, and that if yield by dislocation glide (low-temperature plasticity) occurs, it will do so only at the lowest temperatures (<100 °C). This last mechanism did not appear to be operating in the film studied for this project.

Room-temperature scanning probe microscopy was used to generate out-of-plane deformation maps around Cu vias and polyimide mesas in single-level Cu–polyimide damascene interconnect structures subjected to a room-temperature to 350 °C thermal cycle. The deformation maps are obtained by taking the difference between the images obtained before and after thermal processing. The deformation of the Cu is shown to be highly heterogeneous on the submicrometer scale. Direct evidence of Cu–Ta interfacial sliding, Cu–Cu grain boundary sliding, and diffusion creep is presented. The direction of Cu–Ta sliding is shown to depend on polyimide mesa size. A hot-stage atomic force microscope was used to show that hillock/extrusion growth occurs at temperatures between 130 and 180 °C. We propose that this hillock/extrusion growth is correlated with dips in stress–temperature plots for blanket, uncapped Cu films in the same temperature range and that the absence of dips for nitride-capped Cu films is due to suppression of the hillock/extrusion growth.

Reflectances of Eocene vitrinite from a wide selection of sites in southern British Columbia show a concentration between 0.45 and ~1.0%. Localities with reflectances less than 0.45% may be less deeply buried (Kamloops at 0.25%) than most of the others, younger (Hat Creek), or perhaps associated with an abnormally low geothermal gradient (Princeton?). Localities with abnormally high reflectances (>1.0%) include sites with local heat sources, such as an intrusion (Afton mine near Kamloops), a coal fire (Hat Creek), or a hot, pyroclastic flow (south of Princeton). Other occurrences with high reflectances are those that may have been blanketed by an overthrust sheet (Big Bar), deposited on crustal rocks shortly after they had been tectonically stripped and while they were still warm (Enderby), or otherwise juxtaposed against such deep crustal rocks (White Lake area). Measurement of reflectance plays a useful role in calling attention to abnormal geothermal conditions once the regional pattern is determined.

Prior to construction at Fire Island Inlet, Fire Island was moving westward at more than 200 feet per year, the north shore of the inlet was eroding severely, and navigation in the inlet was difficult. The Federal Jetty, completed in 1941, and the sand dike, built in 1959, have halted the westward migration, eliminated the severe erosion, and partially improved navigation, with minimal maintenance or repair to the structures. There has been a large net accretion of sand east of the jetty and west of the dike, an unknown part of which is at the expense of shores to the west of the inlet. At the State Park on the south side of the inlet interior, erosion accelerated, probably because of the dike. The middle and ocean segments of the 4750-foot Federal Jetty are now (1987) in good condition, although the design implies a stability coefficient for the quarrystone jetty head at time of construction that would now be considered risky. Stability has been promoted by a stone blanket under and east of the jetty, a thick stone apron seaward of the jetty, a low (8 feet MLW) crest, and armor stone that has been partially keyed in place. Damage due to scour, common at other single-jetty inlets, is absent here because longshore transport, which easily overtops the low crest, keeps the inlet channel away from the jetty. Although the two seaward segments of the jetty remain in good condition, the inshore segment of the jetty is in poor condition, despite its apparently sheltered location. The cumulative effects of waves, possibly channeled to the site along recurved spits during storms, have damaged 1200 feet, and tidal scour has destroyed about 230 feet. The damaged segment has a design cross section which is onefifth and one-twelfth the cross sections of the jetty trunk and head.

<span><span style="font-family: Times New Roman;">Ferritic/Martensitic steels, with chromium contents ranging between 9 and 12%, were introduced into fusion material programs due to their better creep resistance and excellent thermal and nuclear properties compared to austenitic stainless steels. Reduced activation ferritic/martensitic (RAFM) steels are considered promising candidates for the test blanket modules of the future International Thermonuclear Experimental Reactor (ITER), being EUROFER steel is the EU reference material. It is a 9 % Cr RAFM steel which exhibits a tempered martensitic <span style="font-family: Times New Roman;">microstructure and presently allows operation up to 550 </span><span style="font-family: Cambria Math;">⁰</span><span style="font-family: Times New Roman;">C. This paper shows the work carried out</span></span><span style="font-family: Times New Roman;"><span style="font-family: Times New Roman;"> to develop at a pilot plant scale a Reduced Activation Ferritic/Martensitic (RAFM) steel, Asturfer </span><span style="font-family: Times New Roman; font-size: xx-small;"><span style="font-family: Times New Roman; font-size: xx-small;">®</span></span><span style="font-family: Times New Roman;">,</span></span><span style="font-family: Times New Roman;"> with chemical composition and mechanical properties very close to EUROFER steel. </span>

AbstractIce-walled melt ponds on the surfaces of active valley-floor rock glaciers and Matthes (Little Ice Age) moraines in the southern Sierra Nevada indicate that most of these landforms consist of glacier ice under thin (ca. 1 - 10 m) but continuous covers of rock-fall-generated debris. These debris blankets effectively insulate the underlying ice and greatly reduce rates of ablation relative to that of uncovered ice. Such insulation explains the observations that ice-cored rock glaciers in the Sierra, actually debris-covered glaciers, are apparently less sensitive to climatic warming and commonly advance to lower altitudes than do adjacent bare-ice glaciers. Accumulation-area ratios and toe-to-headwall-altitude ratios used to estimate equilibrium-line altitudes (ELAs) of former glaciers may therefore yield incorrect results for cirque glaciers subject to abundant rockfall. Inadvertent lumping of deposits from former debris-covered and bare-ice glaciers partially explains an apparently anomalous regional ELA gradient reported for the pre-Matthes Recess Peak Neoglacial advance. Distinguishing such deposits may be important to studies that rely on paleo-ELA estimates. Moreover, Matthes and Recess Peak ELA gradients along the crest evidently depend strongly on local orographic effects rather than latitudinal climatic trends, indicating that simple linear projections and regional climatic interpretations of ELA gradients of small glaciers may be unreliable.

Abstract The geological structures associated with the site of the 55 million m 3 Karameh embankment dam constructed in the Jordan Valley and the tectonic effects on dam foundation and reservoir margins were reviewed. The dam crosses the strike-slip fault of the Jordan Valley Rift Zone. Trace evidence of the fault indicates a displacement of 8 to 15 m over a rupture length of some 130 km, which probably took place several centuries ago. Earthquakes with Richter magnitudes as great as 7.8 have occurred along the Jordan Valley Fault. Deterministic studies by Tapponnier (1992) indicated that the dam design should incorporate the possibility of a 7.8 event, a maximum horizontal rupture displacement on the fault of 10 m and a design peak ground acceleration (PGA) of 0.74 g at the site of the dam. These values are consistent with those which would be used in the USA for a similar case. However, the dam was actually designed by a consultant and constructed for a PGA of about a quarter of this value, based on seismic hazard analysis following guidelines of the International Committee on Large Dams (ICOLD) (1989). Moreover, the dam was designed for displacements of 6 m horizontal and 2 m vertically. Liquefiable sand layers were found in the dam foundation. A PGA of 0.50 g will trigger liquefaction of the sand layers in the dam foundation which would be expected to result in a crest settlement of 4.4 m. Slope stability analysis indicated deep failure planes in the foundation zone. The excavation of loose materials from under the dam foundation has not precluded the possibility of liquefaction occurring under the expected earthquake. Field mapping of geological features during the dam foundation excavation and construction revealed that: a) the most likely location of the Jordan Valley fault is in the area where the Wadi Mallaha stream crosses the dam axis, b) zones of en echelon type open fissures have been defined in the laminates sub-parallel to the Jordan Valley Fault Zone, c) at the Wadi Mallaha stream bed a parallel zone of faulting and warping of the Lisan Formation was identified, and d) the alignment is clearly confirmed by the exposure immediately upstream of the core at Ch 1375. The main wrench fault zone crosses the embankment footprint (upstream to downstream approximately) and reaches the surface around Ch 1375. The critical safety elements of the embankment are the core, the downstream fine filter, the chimney drain and the drainage blanket. To resist large earthquake events safely, the following safety measures should be implemented: 1. A freeboard of 7.0 m instead of the 5.0 m constructed. 2. The foundation of the dam should be stabilized against liquefaction. 3. The embankment internal zoning should be designed to accommodate damage resulting from earthquake events with a magnitude of 7.8. 4. The foundation needs relief measures downstream to lower the pore pressure. This paper describes the measures taken during construction as overall defense against future fault movements through a wide plastic core, an extensive upstream blanket, a 5.0-m thick downstream chimney filter and drain zones, a 5-m freeboard and an upstream crack stopper zone which may be critical for normal faults with a lateral extension component. The geological determination of the main wrench fault alignment resulted in the addition of an extra 2-m width to each of the already wide chimney filter and drain zones. In order to reduce potential seepage, local cut-off trenches or slush grouting were used for treatment of any open fissures at the upstream edge of the external blanket and the right bank ridge. The scale and scope of this dam and inherent engineering geological hazards are unprecedented. The design is considered deficient. This paper documents serious safety issues with the dam. The constructed dam presents serious safety risks and represents a case history of a disaster waiting to happen.

Surficial mapping and geologic information on the nature and evolution of surficial materials in the Slave geologic province indicate that the geotechnical properties and potential ground ice contents associated with these materials depend largely upon their provenance, depositional conditions, and the postglacial climatic history. This information may be used to provide a regional-scale view of the distribution of ground ice conditions and terrain sensitivities associated with various surficial materials. In till veneers and blankets, ground ice content is generally low, as suggested by lack of thermokarst and other permafrost features. However, distinctive surface relief in hummocky till including kettle depressions, rim-ridges, and shallow thaw flowslides may be attributed to massive ice, resulting in sensitive till terrain. Although many outwash sediments have low ice contents near the surface, massive ice ranging from 5 to 10 m thick is present in some eskers and ice-contact outwash sediments. These are associated with thermokarst, slope movement, and collapse features, indicative of meltout or creep of large bodies of massive ice. The terrain sensitivity associated with these deposits is typically low to moderate, due to the coarse-grained nature of the sediments. In contrast, terrain sensitivity is high, and active-layer detachment slides are common along the Coronation Gulf coast where frozen silty clay marine sediments contain a wide range of ice contents. Results from this study may be applied to a much more extensive area of the glaciated western Arctic mainland and adjacent Arctic coastal plain in which materials with a similar glacial history are found.

The first quantitative phylogenetic analysis within the spider family Philodromidae (using 65 morphological characters from 40 ingroup taxa) does not corroborate Schick’s division into the tribes Thanatini (Apollophanes O. P.-Cambridge, 1898, Pelloctanes Schick, 1965, Thanatus C. L. Koch, 1837; Tibellus, Simon, 1875) and Philodromini (Ebo Keyserling, 1884, Philodromus Walckenaer, 1826; Rhysodromus Schick, 1965). Instead, Ebo is sister to all other genera in the family, and a fraction of Philodromus (the histrio species-group = Rhysodromus Schick) are contained with the Thanatini. The forgotten genus Artanes Thorell, 1870 constitutes a well-defined distal taxon in a clade that contains the majority of Philodromus species. Here Artanes is considered a subgenus of Philodromus, and includes the margaritatus and the poecilus species-groups. The western Palearctic species of the subgenus are revised. Twelve species are (re-)described, keyed and illustrated: Philodromus blanckei (Wunderlich, 1995) (first description of ♀); P. calidus Lucas, 1846; P. femurostriatus, sp. nov. from the eastern Mediterranean; P. fuscomarginatus (De Geer, 1778); P. johani, sp. nov. from Crete; P. laricium Simon, 1875, removed from synonymy with P. corticinus (C. L. Koch); P. maghrebi, sp. nov. from northern Africa (♀ only); P. margaritatus (Clerck, 1757); P. parietalis Simon, 1875; P. pentheri, sp. nov. from the Caspian region and Albania (♀ only); P. pinetorum, sp. nov. from the Mediterranean; and P. poecilus (Thorell, 1872).

It's not often that you are asked to come up with an article to a strict deadline but with absolutely no constraints as to the content. It's a challenge but also a luxury. Without a moment's hesitation I chose the journal as my topic. After all it is in JCS that I published my first papers; its editorial board was the first editorial board that I joined; and, of course, since I became Editor-in-Chief it has occupied a significant proportion of my waking thoughts. I was a PhD student in the laboratory of one of the Editors of the journal (now retired), and so it seemed natural that my thesis work would be published in JCS (though, come to think of it, no other options were on offer). We worked hard on my first manuscript until we had it in a form that we were satisfied with. I then left the manuscript with my advisor and, a few days later, he told me that the referees were positive and that the paper was now in press. (Oh happy days - now that I'm Editor my papers get rejected from JCS with some regularity.) While this gave me a very positive experience of science publishing in general and of JCS in particular, it did leave me completely unprepared for the more conventional review process. I was quite shocked when, as a postdoc, I submitted my first paper to a non-JCS journal (J. Cell Biol. in fact) and received referees' reports that were a) in writing, b) critical and c) took almost two months to arrive. I also discovered that JCS did not enjoy the same star billing at MIT as in Oxford and, when I rushed to the library to see my precious papers in print, it was some time before I located the journal in a dusty corner of the building. So, as we hurtle into the new Millennium, are my experiences as a PhD student relevant to publishing in JCS today? I believe that the answer is yes, for two reasons. First, because JCS still strives to be very author-friendly and, second, because any journal inevitably reflects the personalities and tastes of its Editors. JCS has always put the author first. Tangible examples of this philosophy are the open and rapid review process (ahem, I know we do slip up occasionally, so no need to interrupt my New Year hangover with any reminders), rapid, high quality publication, lack of page charges, free reprints and free colour. These features of the journal have undoubtedly benefited non-JCS authors, as competitor journals have been forced to adopt some of our policies. We are also unusual in being owned by a non-profit organisation that is committed to returning the (not inconsiderable) profits of the journal to the scientific community, through support for conferences, grants to allow scientists to visit other laboratories, and so on. While being kind to authors isn't controversial (is it?), the issue of journal content certainly is. We all grumble that such and such a journal ‘likes’ one research area and ‘dislikes’ another, and there is no doubt that for any given journal it is easier to publish some types of paper than others (thereby, of course, creating a convenient niche for new journals to fill). Here I would make two points: you can't publish papers that aren't submitted; and it is much easier to edit a journal with a modest number of submissions (JCS pre-1992) than to edit one in which the number of submissions exceeds the page allocation by a factor of greater than four (JCS at the cusp of the Millennium). As the impact factor of JCS has crept upwards, submissions have soared, but there is still a need to attract stronger papers, and so I spend a fair amount of time talking to potential authors and soliciting manuscripts, using any of the inducements at my disposal (sliding scale available on request). Along the way I seem to spend a lot of time over drinks in dingy conference bars, listening to authors' tales of cruel mistreatment at the hands of other journals; sometimes it is a struggle to remember exactly what I promised once I am safely back in my own lab. My tastes in cell biology are famously eclectic, but at some point in the last few years we no longer had space to publish all the scientifically sound papers that were being submitted. We were forced to resort to editorial rejections. This is when an Editor decides that a piece of work should not appear in the journal, even if the referees were to be positive, and therefore that the paper should not be sent out for review. Ouch! It always hurts to have a paper rejected in this way. We bend over backwards to spell out at the front of the journal the type of paper that will be editorially rejected and to explain the reasons for rejection in the decision letter to the author. An author can always appeal, in which case we will almost always send the paper out for review (and sadly the referees almost always tick the ‘too descriptive’, insufficient advance' or ‘insufficient general interest’ box on the report form). Even if space were not a limitation (and it will not be when hard copy journals disappear) there would still be the constant desire to improve the quality of the journal, the crude index of which is the impact factor. It is worth pointing out that the motivation to publish better and better science is largely the Editors' own and has almost nothing to do with the commercial success of the journal. It comes as a surprise to most scientists to discover that a large portfolio of journals with tiny circulations and mediocre content can potentially make as much money as one blockbuster journal; if the authors pay high enough page charges you enter the lucrative world of vanity publishing. Nor does it matter if a journal has a life span of only a few years; its demise is devastating for the scientists who put so much effort into it, but for the publisher it can simply be replaced with another new journal and another new title. Oops, I am beginning to sound cynical (but remember that I am writing this in 1999 and the rays of the new Millennium have yet to warm my soul). If the discrepancy between commercial success and scientific success is one issue that I brood on, the other is the growing ‘professionalisation’of science publishing. ‘Amateur’ editors, such as myself, who combine editing with running a research lab, are not quite an endangered species, but we are probably decreasing in number. We are being replaced by people who have left bench science after a PhD and, often, postdoctoral training and have taken up science publishing as a career. There have always been PhDs involved in different aspects of journal publishing, but I am thinking particularly of the growing numbers who actually determine the scientific content of the journal. At their best professional Editors are unparalleled in the flair that they bring to the job - witness the legendary Miranda Robertson and Benjamin Lewin. At their worst they have the mentality of failed postdocs, their understanding of science frozen at the point where they retired, injured, from the fray. At conferences they will assiduously take notes during the talks by their former colleagues and stare blankly into space when subjects that they are unfamiliar with are presented. They become fashion junkies, unable to decide for themselves what their journal should be publishing this season. The JCS experience of ‘professionalisation’, I hasten to add, has been totally positive (otherwise this bit would have been mysteriously edited out!). By recruiting a staff editor we have been able to take new initiatives we simply didn't have the time or energy for before. Without him ‘Editorials’, ‘In This Issue’ and a constant flow of interesting review articles would never have become reality - and there are plenty of other innovations in the pipeline. I believe in a partnership between the amateurs and the professionals, with the amateurs providing an accountability and a practical perspective that can only come from being active in the lab. No article about science publishing is complete without some pontification on electronic publishing. I'm all for it (electronic publishing, that is) for all the reasons that are rehearsed ad nauseam, but also out of nostalgia for those papers I published when I was a PhD student. Electronic publication can free us from the severe restrictions that are currently imposed on the length of individual articles. Of course it is already possible to publish supplementary material, such as movies and methods, on journal web sites, but what I would like to see is a return to longer reference lists. When I was beavering away on my first JCS paper, I took great trouble to cite all the relevant literature, both recently published and ancient (i.e. more than three years old). These days, so often, in the interests of space we restrict our citations to the newest papers, the papers in the top three journals or, worse, avoid the primary publications altogether and rely on reviews. All too often the Acknowledgements at the end of an article will include a blanket apology to those authors whose work could not be cited owing to lack of space. It would be doing science a great service if we could, once more, enjoy the luxury and the responsibility of placing our own work both in the context of the papers that preceded it and in a wider context than our own narrow research area. So, happy Millennium - and thank you to all the unsung heroes of JCS: the authors, referees, Editors and board members and all the staff who miraculously turn the constant deluge of accepted papers into a rather fine journal.

AbstractIn this investigation, a thermo-mechanical model of pebble beds is adopted and developed based on experiments by Dr. Reimann at Forschungszentrum Karlsruhe (FZK). The framework of the present material model is composed of a non-linear elastic law, the Drucker-Prager-Cap theory, and a modified creep law. Furthermore, the volumetric inelastic strain dependent thermal conductivity of beryllium pebble beds is taken into account and full thermo-mechanical coupling is considered.Investigation showed that the Drucker-Prager-Cap model implemented in ABAQUS can not fulfill the requirements of both the prediction of large creep strains and the hardening behaviour caused by creep, which are of importance with respect to the application of pebble beds in fusion blankets [1]. Therefore, UMAT (user defined material's mechanical behaviour) and UMATHT (user defined material's thermal behaviour) routines are used to re-implement the present thermo-mechanical model in ABAQUS. An elastic predictor radial return mapping algorithm is used to solve the non-associated plasticity iteratively, and a proper tangent stiffness matrix is obtained for cost-efficiency in the calculation. An explicit creep mechanism is adopted for the prediction of time-dependent behaviour in order to represent large creep strains in high temperature. Finally, the thermo-mechanical interactions are implemented in a UMATHT routine for the coupled analysis.The oedometric compression tests and creep tests of pebble beds at different temperatures are simulated with the help of the present UMAT and UMATHT routines, and the comparison between the simulation and the experiments is made.

The Mountain Zebra National Park (MZNP) has been extended over the last couple of years. One of the newly procured areas is the Doornhoek section, which had been adjacent to the park. To develop scientifically sound management programmes for conservation areas, it is essential that an inventory of their natural resources be undertaken. The aim of this study was to classify, describe and map the vegetation of the Doornhoek section of the park. The floristic data were analysed in accordance with the Braun-Blanquet procedures using the BBPC suite. The data analysis resulted in the identification of eight communities, which can be grouped into seven major community types (Rhus lucida–Buddleja glomerata Shrubland, Rhigozum obovatum–Rhus longispina Shrubland, Helichrysum dregeanum–Aristida diffusa Grassland, Pentzia globosa–Enneapogon scoparius Grassland, Aristida adscensionus–Pentzia globosa Grassland, Cadaba aphylla–Acacia karroo Woodland and Lycium oxycarpum–Acacia karroo Woodland). Four of these communities occur on the higher-lying plateau, mid-slope and crest areas, while the other four communities are located on the lower-lying mid-plateau and foot slope, along drainage lines and in valley-bottom areas. The description of the plant communities, together with the vegetation map, can serve as a basis for formulating a management programme for the larger park. Although sections of Doornhoek have been overgrazed and degraded in the past, its recent addition to the MZNP contributes to the available habitat preferred by large herbivores, such as valley bottoms, foot-slopes and plateaux.

The first time I read Hélène Cixous’s The Laugh of the Medusa I swooned. I wanted to write the whole thing out, large, and black, and pin it across an entire wall. I was 32 and vulnerable around polemic texts (I was always copying out quotes and sticking them to my walls, trying to hold onto meaning, unable to let the writing I read slip out and away). You must "write your self, your body must be heard" (Cixous 880), I read, as if for the hundredth time, even though it was the first. Those decades old words had an echoing, a resonance to them, as if each person who had read them had left their own mnemonic mark there, so that by the time they reached me, they struck, immediately, at my core (not the heart or the spine, or even the gut, but somewhere stickier; some pulsing place in amongst my organs, somewhere not touched, a space forgotten). The body that read The Laugh was so big its knees had trouble lifting it from chairs (“more body, hence more writing”, Cixous 886), and was soon to have its gallbladder taken. Its polycystic ovaries dreamed, lumpily and without much hope, of zygotes. The body that read The Laugh was a wobbling thing, sheathed in fat (as if this could protect it), with a yearning for sveltness, for muscle, for strength. Cixous sang through its cells, and called it to itself. The body that read The Laugh wrote itself back. It spoke about dungeons, and walls that had collected teenaged fists, and needles that turned it somnambulant and concave and warm until it was not. It wrote trauma in short and staggering sentences (out, get it out) as if narrative could save it from a fat-laden and static decline. Text leaked from tissue and bone, out through fingers and onto the page, and in increments so small I did not notice them, the body took its place. I was, all-of-a-sudden, more than my head. And then the body that read The Laugh performed the ultimate coup, and conceived.The body wrote then about its own birth, and the birth of its mother, and when its own children were born, of course, of course, about them. “Oral drive, anal drive, vocal drive–all these drives are our strengths, and among them is the gestation drive–all just like the desire to write: a desire to live self from within, a desire for the swollen belly, for language, for blood” (Cixous 891). The fat was gone, and in its place this other tissue, that later would be he. What I know now is that the body gets what the body wants. What I know now is that the body will tell its story, because if you “censor the body [… then] you censor breath and speech at the same time” (Cixous 880).I am trying to find a beginning. Because where is the place where I start? I was never a twinkle in my mother’s eye. It was the seventies. She was 22 and then 23–there was nothing planned about me. Her eyes a flinty green, hair long and straight. When I think of her then I remember this photo: black and white on the thick photo paper that is hard to get now. No shiny oblong spat from a machine, this paper was pulled in and out of three chemical trays and hung, dripping, in a dark red room to show me a woman in a long white t-shirt and nothing else. She stares straight out at me. On the shirt is a women’s symbol with a fist in the middle of it. Do you know the one? It might have been purple (the symbol I mean). When I think of her then I see her David Bowie teeth, the ones she hated, and a packet of Drum tobacco with Tally-Hos tucked inside, and some of the scars on her forearms, but not all of them, not yet. I can imagine her pregnant with me, the slow gait, that fleshy weight dragging at her spine and pelvis. She told me the story of my birth every year on my birthday. She remembers what day of the week the contractions started. The story is told with a kind of glory in the detail, with a relishing of small facts. I do the same with my children now. I was delivered by forceps. The dent in my skull, up above my right ear, was a party trick when I was a teenager, and an annoyance when I wanted to shave my head down to the bone at 18. Just before Jem was born, I discovered a second dent behind my left ear. My skull holds the footprint of those silver clamps. My bones say here, and here, this is where I was pulled from you. I have seen babies being born this way. They don’t slide out all sealish and purple and slippy. They are pulled. The person holding the forcep handles uses their whole body weight to yank that baby out. It makes me squirm, all that pulling, those tiny neck bones concertinaing out, the silver scoops sinking into the skull and leaving prints, like a warm spoon in dough. The urgency of separation, of the need to make two things from one. After Jem was born he lay on my chest for hours. As the placenta was birthed he weed on me. I felt the warm trickle down my side and was glad. There was nothing so right as my naked body making a bed for his. I lay in a pool of wet (blood and lichor and Jem’s little wee) and the midwives pushed towels under me so I wouldn’t get cold. He sucked. White waffle weave blankets over both of us. That bloody nest. I lay in it and rested my free hand on his vernix covered back; the softest thing I had ever touched. We basked in the warm wet. We basked. How do I sew theory into this writing? Julia Kristeva especially, whose Stabat Mater describes those early moments of holding the one who was inside and then out so perfectly that I am left silent. The smell of milk, dew-drenched greenery, sour and clear, a memory of wind, of air, of seaweed (as if a body lived without waste): it glides under my skin, not stopping at the mouth or nose but caressing my veins, and stripping the skin from the bones fills me like a balloon full of ozone and I plant my feet firmly on the ground in order to carry him, safe, stable, unuprootable, while he dances in my neck, floats with my hair, looks right and left for a soft shoulder, “slips on the breast, swingles, silver vivid blossom of my belly” and finally flies up from my navel in his dream, borne by my hands. My son (Kristeva, Stabat Mater 141). Is theory more important than this? The smell of milk (dried, it is soursweet and will draw any baby to you, nuzzling and mewling), which resides alongside the Virgin Mother and the semiotics of milk and tears. The language of fluid. While the rest of this writing, the stories not of mothers and babies, but one mother and one baby, came out smooth and fast, as soon as I see or hear or write that word, theory, I slow. I am concerned with the placement of things. I do not have the sense of being free. But if there’s anything that should come from this vain attempt to answer Cixous, to “write your self. Your body must be heard” (880), it should be that freedom and theory, boundary-lessness, is where I reside. If anything should come from this, it is the knowing that theory is the most creative pursuit, and that creativity will always speak to theory. There are fewer divisions than any of us realise, and the leakiness of bodies, of this body, will get me there. The smell of this page is of lichor; a clean but heady smell, thick with old cells and a foetus’s breath. The smell of this page is of blood and saliva and milk mixed (the colour like rotten strawberries or the soaked pad at the bottom of your tray of supermarket mince). It is a smell that you will secretly savour, breathe deeply, and then long for lemon zest or the sharpness of coffee beans to send away that angelic fug. That milk and tears have a language of their own is undeniable. Kristeva says they are “metaphors of non-language, of a ‘semiotic’ that does not coincide with linguistic communication” (Stabat Mater 143) but what I know is that these fluids were the first language for my children. Were they the first language for me? Because “it must be true: babies drink language along with the breastmilk: Curling up over their tongues while they take siestas–Mots au lait, verbae cum lacta, palabros con leche” (Wasserman quoted in Giles 223). The enduring picture I have of myself as an infant is of a baby who didn’t cry, but my mother will tell you a different story, in the way that all of us do. She will tell you I didn’t smile until I was five months old (Soli and Jem were both beaming at three months). Born six weeks premature, my muscles took longer to find their place, to assemble themselves under my skin. She will tell you I screamed in the night, because all babies do. Is this non-language? Jem was unintelligible much of the time. I felt as if I was holding a puzzle. Three o’clock in the morning, having tried breastfeeds, a bath with Nick Drake’s Pink Moon, bouncing him in a baby sling on the fitball (wedged into a corner so that if I nodded off I would hopefully swoon backwards, and the wall would wake me), walking him around and around while rocking and singing, then breastfeeding again, and still he did not sleep, and still he cried and clawed at my cheeks and shoulders and wrists and writhed; I could not guess at what it was he needed. I had never been less concerned with the self that was me. I was all breasts and milk and a craving for barbecued chicken and watermelon at three in the morning because he was drinking every ounce of energy I had. I was arms and a voice. I was food. And then I learnt other things; about let downs and waking up in pools of the stuff. Wet. Everywhere. “Lactating bodies tend towards anarchy” (Bartlett 163). Any body will tend towards anarchy – there is so much to keep in – but there are only so many openings a person can keep track of, and breastfeeding meant a kind of levelling up, meant I was as far from clean and proper as I possibly could be (Kristeva, Powers of Horror 72).In the nights I was not alone. Caren could not breastfeed him, but could do everything else, and never said I have to work tomorrow, because she knew I was working too. During waking hours I watched him constantly for those mystical tired signs, which often were hungry signs, which quickly became overtired signs. There was no figuring it out. But Soli, with Soli, I knew. The language of babies had been sung into my bones. There is a grammar in crying, a calling out and telling, a way of knowing that is older than I’ll ever be. Those tiny bodies are brimming with semiotics. Knees pulled up is belly ache, arching is tired, a look to the side I-want-that-take-me-there-not-there. There. Curling in, the whole of him, is don’t-look-at-me-now-hands-away. Now he is one he uses his hands to tell me what he wants. Sign language because I sign and so, then, does he, but also an emphatic placing of my hands on his body or toys, utensils, swings, things. In the early hours of a Wednesday morning I tried to stroke his head, to close his wide-open eyes with my fingertips. He grabbed my hand and moved it to his chest before I could alight on the bridge of his nose. And yesterday he raised his arm into the air, then got my hand and placed it into his raised hand, then stood, and led me down to the laundry to play with the dustpan and broom. His body, literally, speaks.This is the language of mothers and babies. It is laid down in the darkest part of the night. Laid down like memory, like dreams, stitched into tiredness and circled with dread adrenalin and fear. It will never stop. That baby will cry and I will stare owl-eyed into the dark and bend my cracking knees (don’t shake the baby it will only make it worse don’t shake don’t). These babies will grow into children and then adults who will never remember those screaming nights, cots like cages, a stuffed toy pushed on them as if it could replace the warmth of skin and breath (please, please, little bear, replace the warmth of skin and breath). I will never remember it, but she will. They will never remember it, but we will. Kristeva says too that mothers are in a “catastrophe of identity which plunges the proper Name into that ‘unnameable’ that somehow involves our imaginary representations of femininity, non-language, or the body” (Stabat Mater 134). A catastrophe of identity. The me and the not-me. In the night, with a wrapped baby and aching biceps, the I-was batting quietly at the I-am. The I-am is all body. Arms to hold and bathe and change him, milk to feed him, a voice to sing and soothe him. The I-was is a different beast, made of words and books, uninterrupted conversation and the kind of self-obsession and autonomy I didn’t know existed until it was gone. Old friends stopped asking me about my day. They asked Caren, who had been at work, but not me. It did not matter that she was a woman; in this, for most people we spoke to, she was the public and I was the private, her work mattered and mine did not. Later she would commiserate and I would fume, but while it was happening, it was near impossible to contest. A catastrophe of identity. In a day I had fed and walked and cried and sung and fed and rocked and pointed and read books with no words and rolled inane balls across the lounge room floor and washed and sung and fed. I had circled in and around while the sun traced its arc. I had waited with impatience for adult company. I had loved harder than I ever had before. I had metamorphosed and nobody noticed. Nobody noticed. A catastrophe of identity it was, but the noise and visibility that the word catastrophe invokes was entirely absent. And where was the language to describe this peeling inside out? I was burnished bright by those sleepless nights, by the requirement of the I-am. And in those nights I learned what my mother already knew. That having children is a form of grief. That we lose. But that we gain. At 23, what’s lost is possibility. She must have seen her writer’s life drilling down to nothing. She knew that Sylvia Plath had placed her head, so carefully on its pillow, in that gas filled place. No pungent metaphor, just a poet, a mother, who could not continue. I had my babies at 34 and 36. I knew some of what I would lose, but had more than I needed. My mother had started out with not enough, and so was left concave and edged with desperation as she made her way through inner-city Sydney’s grime, her children singing from behind her wait for me, wait for me, Mama please wait for me, I’m going just as fast as I can.Nothing could be more ‘normal’ than that a maternal image should establish itself on the site of that tempered anguish known as love. No one is spared. Except perhaps the saint or the mystic, or the writer who, by force of language, can still manage nothing more than to demolish the fiction of the mother-as-love’s-mainstay and to identify with love as it really is: a fire of tongues, an escape from representation (Kristeva, Stabat Mater 145).We transformed, she and I. She hoped to make herself new with children. A writer born of writers, the growing and birthing of our tiny bodies forced her to place pen to paper, to fight to write. She carved a place for herself with words but it kept collapsing in on her. My father’s bi-polar rages, his scrubbing evil spirits from the soles of her shoes in the middle of the night, wore her down, and soon she inhabited that maternal image anyway, in spite of all her attempts to side step it. The mad mother, the single mother, the sad mother. And yes I remember those mothers. But I also remember her holding me so hard sometimes I couldn’t breathe properly, and that some nights when I couldn’t sleep she had warm eyes and made chamomile tea, and that she called me angel. A fire of tongues, but even she, with her words, couldn’t escape from representation. I am a writer born of writers born of writers (triply blessed or cursed with text). In my scramble to not be mad or bad or sad, I still could not escape the maternal image. More days than I can count I lay under my babies wishing I could be somewhere, anywhere else, but they needed to sleep or feed or be. With me. Held captive by the need to be a good mother, to be the best mother, no saint or mystic presenting itself, all I could do was write. Whole poems sprang unbidden and complete from my pen. My love for my children, that fire of tongues, was demolishing me, and the only way through was to inhabit this vessel of text, to imbibe the language of bodies and tears and night, and make from it my boat.Those children wrote my body in the night. They taught me about desire, that unbounded scribbling thing that will not be bound by subjectivity, by me. They taught me that “the body is literally written on, inscribed, by desire and signification” (Grosz 60), and every morning I woke with ashen bones and poetry aching out through my pores, with my body writing me.This Mother ThingI maintain that I do not have to leavethe house at nightall leathery and eyelinered,all booted up and raw.I maintain that I do not miss thosesmoky rooms (wait that’s not allowed any more)where we strut and, without looking,compare tattoos.Because two years ago I had you.You with your blonde hair shining, your eyes like a creek after rain, that veinthat’s so blue on the side of your small nosethat people think you’ve been bruised.Because two years ago you cameout of me and landed here and grew. There is no going out. We (she and me) washand cook and wash and clean and love.This mother thing is the making of me but I missthose pulsing rooms,the feel of all of you pressing in onall of me.This mother thing is the making of me. And in text, in poetry, I find my home. “You only have to look at the Medusa straight on to see her. And she’s not deadly. She’s beautiful and she’s laughing” (Cixous 885). The mother-body writes herself, and is made new. The mother-body writes her own mother, and knows she was always-already here. The mother-body births, and breastfeeds, and turns to me in the aching night and says this: the Medusa? The Medusa is me.ReferencesBartlett, Alison. Breastwork: Rethinking Breastfeeding. Sydney: UNSW Press, 2005.Cixous, Hélène, Keith Cohen, and Paula Cohen (Trans.). "The Laugh of the Medusa." Signs 1.4 (1976): 875-93. Giles, Fiona. Fresh Milk. Crows Nest, NSW: Allen & Unwin, 2003. Grosz, Elizabeth. Volatile Bodies: Toward a Corporeal Feminism. St Leonards, NSW: Allen & Unwin, 1994.Kristeva, Julia, and Leon S. Roudiez (Trans.) Powers of Horror: An Essay on Abjection. New York: Columbia University Press, 1982.Kristeva, Julia, and Arthur Goldhammer (Trans.). "Stabat Mater." Poetics Today 6.1-2 (1985): 133-52.