Investigation of direct waste-activated sludge dewatering benefits and costs in a water resource recovery facility.

Dewatering of anaerobic digested (AD) sludge containing waste-activated sludge (WAS) from enhanced biological phosphorus removal (EBPR) poses numerous challenges including poor dewaterability, struvite scale formation, and recycling of high N and P levels in the sludge liquor to the treatment process. A full-scale water reclamation facility was investigated to mitigate these problems by experimenting with direct dewatering of EBPR WAS, bypassing the AD step. The investigations experimented with various blends of AD primary sludge with undigested thickened WAS to achieve dewatering performance improvements and overall operational cost savings. Direct thickened WAS dewatering has had many positive impacts including enhanced sludge cake solids concentration, reduced chemical use for facility operations, reduced struvite scaling, reduced biogas conditioning media servicing, eliminated need for centrate treatment, recovered capacity of existing unit operations including anaerobic digesters, and eliminated several proposed capital improvement projects that were previously deemed necessary. Although bypassing of WAS to AD reduced total biogas production, the specific gas yield increased to meet all of the facility's biogas demands and minimized excess gas flaring. The overall biosolids production mass increased causing increased transportation costs for disposal and caused notable odors, both of which are being currently investigated. PRACTITIONER POINTS: Direct WAS dewatering bypassing anaerobic digestion yields operational and process benefits in an EBPR water resource recovery facility Dewatered cake solids were increased compared with combined primary and WAS anaerobic digestion and dewatering Nutrient loads in sludge processing returns streams and operational costs are reduced by direct WAS dewatering.

How Is Science Being Taught? Measuring Evidence-Based Teaching Practices across Undergraduate Science Departments.

While there is a wealth of research evidencing the benefits of active-learning approaches, the extent to which these teaching practices are adopted in the sciences is not well known. The aim of this study is to establish an evidential baseline of teaching practices across a bachelor of science degree program at a large research-intensive Australian university. Our purpose is to contribute to knowledge on the adoption levels of evidence-based teaching practices by faculty within a science degree program and inform our science curriculum review in practical terms. We used the Teaching Practices Inventory (TPI) to measure the use of evidence-based teaching approaches in 129 courses (units of study) across 13 departments. We compared the results with those from a Canadian institution to identify areas in need of improvement at our institution. We applied a regression analysis to the data and found that the adoption of evidence-based teaching practices differs by discipline and is higher in first-year classes at our institution. The study demonstrates that the TPI can be used in different institutional contexts and provides data that can inform practice and policy.

Measuring the 2D baryon acoustic oscillation signal of galaxies in WiggleZ: cosmological constraints.

We present results from the 2D anisotropic baryon acoustic oscillation (BAO) signal present in the final data set from the WiggleZ Dark Energy Survey. We analyse the WiggleZ data in two ways: first using the full shape of the 2D correlation function and secondly focusing only on the position of the BAO peak in the reconstructed data set. When fitting for the full shape of the 2D correlation function we use a multipole expansion to compare with theory. When we use the reconstructed data we marginalize over the shape and just measure the position of the BAO peak, analysing the data in wedges separating the signal along the line of sight from that parallel to the line of sight. We verify our method with mock data and find the results to be free of bias or systematic offsets. We also redo the pre-reconstruction angle-averaged (1D) WiggleZ BAO analysis with an improved covariance and present an updated result. The final results are presented in the form of Ω c h2, H(z), and DA (z) for three redshift bins with effective redshifts z = 0.44, 0.60, and 0.73. Within these bins and methodologies, we recover constraints between 5 and 22 per cent error. Our cosmological constraints are consistent with flat ΛCDM cosmology and agree with results from the Baryon Oscillation Spectroscopic Survey.

AIDS and agriculture in Zambia.

BACKGROUND: Because agriculture is the livelihood base for the majority of people affected by AIDS in sub-Saharan Africa, the interactions between AIDS and agriculture, and their implications for policy and programming, are of fundamental importance. OBJECTIVE: This paper summarizes evidence from three RENEWAL (Regional Network on AIDS, Livelihoods, and Food Security) research studies and one policy review on the interactions between AIDS and agriculture in Zambia and their implications for future policy and programming. METHODS: The unit of analysis adopted for each study varies, spanning the individual, household, cluster, and community levels, drawing attention to the wider socioeconomic landscape within which households operate. Results. This paper identifies the ways in which livelihood activities, within the prevailing norms of gender, sexuality, and perceptions of risk in rural Zambia, can influence susceptibility to HIV and how the nature and severity of the subsequent impacts of AIDS are modified by the specific characteristics and initial conditions of households, clusters, and communities. CONCLUSIONS: The findings demonstrate the importance of studying the risks, vulnerabilities, and impacts of the AIDS epidemic in the context of multiple resource flows and relationships between and within households-and in the context of other drivers of vulnerability, some of which interact with HIV and AIDS. The paper addresses several factors that enable or hinder access to formal support programs, and concludes by highlighting the particular importance of engaging communities proactively in the response to HIV and AIDS, to ensure relevance, sustainability, and scale.