504 research outputs found
Coupled oceanâatmosphere interactions between the MaddenâJulian oscillation and synoptic-scale variability over the warm pool
A principal component analysis of the combined fields of sea surface temperature (SST) and surface zonal and meridional wind reveals the dominant mode of intraseasonal (30-70-day) co-variability during northern winter in the tropical Eastern Hemisphere is that of the Madden-Julian Oscillation (MJO). Regression calculations show that the submonthly (30-day high-pass filtered) surface wind variability is significantly modulated during the MJO. Regions of increased (decreased) submonthly surface wind variability propagate eastward, approximately in phase with the intraseasonal surface westerly (easterly) anomalies of the MJO. Due to the dependence of the surface latent heat flux on the magnitude of the total wind speed, this systematic modulation of the submonthly surface wind variability produces a significant component in the intraseasonal latent heat flux anomalies, which partially cancels the latent heat flux anomalies due to the slowly varying intraseasonal wind anomalies, particularly south of 10S. A method is derived that demodulates the submonthly surface wind variability from the slowly varying intraseasonal wind anomalies. This method is applied to the wind forcing fields of a one-dimensional ocean model. The model response to this modified forcing produces larger intraseasonal SST anomalies than when the model is forced with the observed forcing over large areas of the southwest Pacific Ocean and southeast Indian Ocean during both phases of the MJO. This result has implications for accurate coupled modeling of the MJO. A similar calculation is applied to the surface shortwave flux, but intraseasonal modulation of submonthly surface shortwave flux variability does not appear to be important to the dynamics of the MJO
Methanosarcinaceae and acetate-oxidizing pathways dominate in high-rate thermophilic anaerobic digestion of waste-activated sludge
This study investigated the process of high-rate, high-temperature methanogenesis to enable very-high-volume loading during anaerobic digestion of waste-activated sludge. Reducing the hydraulic retention time (HRT) from 15 to 20 days in mesophilic digestion down to 3 days was achievable at a thermophilic temperature (55°C) with stable digester performance and methanogenic activity. A volatile solids (VS) destruction efficiency of 33 to 35% was achieved on waste-activated sludge, comparable to that obtained via mesophilic processes with low organic acid levels
Phosphorus recovery: a need for an integrated approach
Increasing cost of phosphate fertilizer, a scarcity of high quality phosphate rock (PR)and increasing surface water pollution are driving aneed to accelerate the recovery and re-use ofphosphorus (P) from various waste sectors. Options to recover P occur all along the open P cycle from mining to households to oceans. However, P recovery as a regional and global strategy towards P sustainability and future food, bio energy and water security is in its infancy because of a number of technological, socio-economic and institutional constraints. There is no single solution and resolving these constraints requires concerted collaboration betweenrelevant stakeholders and an integrated approach combiningsuccessful business models withsocio-economic and institutional change. We suggest that an operational framework is developed for fast tracking cost-effective recovery options
Contested resources: unions, employers, and the adoption of new work practices in US and UK telecommunications
The pattern of adoption of high-performance work practices has been explained in terms of strategic contingency and in terms of union presence. We compare the post-deregulation/privatization changes in work practice at AT&T, Bell Atlantic and British Telecom. On the basis of these cases, we argue that the choice of new work practices should be understood as a consequence not only of the company's resources or changes in its environment, nor of a simple union presence, but also as a consequence of the practices' effects on union power, the nature of the union's engagement, and the union's strategic choices
Identification of synergistic impacts during anaerobic co-digestion of organic wastes
Anaerobic co-digestion has been widely investigated, but there is limited analysis of interaction between substrates. The objective of this work was to assess the role of carbohydrates, protein and lipids in co-digestion behaviour separately, and together. Two sets of batch tests were done, each set consisting of the mono-digestion of three substrates, and the co-digestion of seven mixtures. The first was done with pure substrates - cellulose, casein and olive oil - while in the second slaughterhouse waste - paunch, blood and fat - were used as carbohydrate, protein and lipid sources, respectively. Synergistic effects were mainly improvement of process kinetics without a significant change in biodegradability. Kinetics improvement was linked to the mitigation of inhibitory compounds, particularly fats dilution. The exception was co-digestion of paunch with lipids, which resulted in an improved final yield with model based analysis indicating the presence of paunch improved degradability of the fatty feed
The difference that tenure makes
This paper argues that housing tenures cannot be reduced to either production relations or consumption relations. Instead, they need to be understood as modes of housing distribution, and as having complex and dynamic relations with social classes. Building on a critique of both the productionist and the consumptionist literature, as well as of formalist accounts of the relations between tenure and class, the paper attempts to lay the foundations for a new theory of housing tenure. In order to do this, a new theory of class is articulated, which is then used to throw new light on the nature of class-tenure relations
Variations in concerns reported on the Patient Concerns Inventory (PCI) in head and neck cancer patients from different health settings across the world
Background: The aim was to collate and contrast patient concerns from a range of different head and neck cancer follow-up clinics around the world. Also, we sought to explore the relationship, if any, between responses to the patient concerns inventory (PCI) and overall quality of life (QOL). Methods: Nineteen units participated with intention of including 100 patients per site as close to a consecutive series as possible in order to minimize selection bias. Results: There were 2136 patients with a median total number of PCI items selected of 5 (2-10). âFear of the cancer returningâ (39%) and âdry mouthâ (37%) were most common. Twenty-five percent (524) reported less than good QOL. Conclusion: There was considerable variation between units in the number of items selected and in overall QOL, even after allowing for case-mix variables. There was a strong progressive association between the number of PCI items and QOL
The leadership component of Kellyâs Mobilisation Theory : contribution, tensions, limitations and further development
This reassessment of Kellyâs analysis of the relationship of activist leadership to collective action within the overall jigsaw of mobilisation theory draws on social movement literature, studies by industrial relations scholars utilising aspects of Kellyâs approach â including this authorâs own work â and related research on union leadership within collective mobilisation. In the process, it identifies and celebrates how Kellyâs work, whilst contributing a distinct and substantive actor-related approach, recognised that leadership is one ingredient amongst other factors, including important structural opportunities and constraints. It considers three potential ambiguities/tensions within Kellyâs conceptualisation of leadership related to the social construction of workersâ interests, spontaneity of workersâ action and the âleader/followerâ interplay. The review also identifies two important limitations, related to the union member/bureaucracy dynamic and the role of left-wing political leadership, and concludes by signalling different forms of leadership relationships on which further refinement and development would be fruitful
Anaerobic membrane bioreactors enable high rate treatment of slaughterhouse wastewater
Anaerobic membrane bioreactors (AnMBRs) enable high space loading by retaining solids selectively through microfiltration membranes. For organic industrial wastewaters, this offers an alternative to lagoons and granule based high-rate anaerobic treatment due to excellent effluent quality, high tolerance to load variations, and ability to produce a solids free effluent for the purposes of reuse. While there has been extensive work on low-strength and low solids effluent, there has been limited application in high-solids, high fats systems such as slaughterhouse wastewater, which are a key application. A 200L AnMBR pilot plant operated at 2 Australian cattle slaughterhouses consistently removed over 95% of chemical oxygen demand (COD) from the wastewater. Virtually all degradable COD was converted to biogas, 78-90% of nitrogen and 74% of phosphorus in the wastewater were released to the treated permeate as ammonia and phosphate, respectively; which would enable subsequent nutrient capture. The mass loading rate limit of 3-3.5g CODLd is imposed by the active biomass inventory, with this in turn limited to 40gL (TS) by the need to manage membrane fouling control
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