On natures of sub-gap photoelectric and optical spectra in nitrogen-contaminated nanocrystalline diamond

Experimentally observed optical and photoelectrical spectra of nitrogen-contaminated (unintentionally doped) nano-crystalline CVD diamond films are simulated using semi-empirical adiabatic General Skettrup Model (GSM), which presumes dominant contributions of defect states from sp 3-coordinated intra-granular carbon atoms to intra-band single electron spectrum N(E) of the material. This picture disagrees with a common viewpoint that the N(E) spectrum of the gap states in diamond powders and polycrystalline CVD films mainly originates from π and π* bonds of sp2-coordinated carbon atoms, which are distributed nearly uniformly over outer surfaces and/or interfaces of the diamond grains. The GSM predicts as well strong effect of granular morphology on the density of intra-band defect states in polycrystalline diamonds.

Reactive Oxygen Species and Reactive Nitrogen Species in Epigenetic Modifications

For the normal homeostasis of a cell, there must be a balance between radical oxygen species/radical nitrogen species (ROS/RNS) production and the neutralization of these species by antioxidant scavenging. In times of stress, this balance is not maintained, and the result is oxidative stress. This stress can affect many pathways in the body and result in pathological consequences. Recent evidence suggests that ROS/RNS can affect the epigenetic regulation of genes by affecting the function of histone and DNA modifying enzymes, thus affecting phenotypic changes within the cellular environment. In the following chapter, we provide a broad overview of how oxidative stress induced by ROS/RNS can affect epigenetics, and using lung disease as our model we link the connection between these processes.

Nitrous oxide emissions from fertilized, irrigated cotton (Gossypium hirsutum L.) in the Aral Sea Basin, Uzbekistan : influence of nitrogen applications and irrigation practices

Nitrous oxide emissions were monitored at three sites over a 2-year period in irrigated cotton fields in Khorezm, Uzbekistan, a region located in the arid deserts of the Aral Sea Basin. The fields were managed using different fertilizer management strategies and irrigation water regimes. N2O emissions varied widely between years, within 1 year throughout the vegetation season, and between the sites. The amount of irrigation water applied, the amount and type of N fertilizer used, and topsoil temperature had the greatest effect on these emissions. Very high N2O emissions of up to 3000 μg N2O-N m−2 h−1 were measured in periods following N-fertilizer application in combination with irrigation events. These “emission pulses” accounted for 80–95% of the total N2O emissions between April and September and varied from 0.9 to 6.5 kg N2O-N ha−1.. Emission factors (EF), uncorrected for background emission, ranged from 0.4% to 2.6% of total N applied, corresponding to an average EF of 1.48% of applied N fertilizer lost as N2O-N. This is in line with the default global average value of 1.25% of applied N used in calculations of N2O emissions by the Intergovernmental Panel on Climate Change. During the emission pulses, which were triggered by high soil moisture and high availability of mineral N, a clear diurnal pattern of N2O emissions was observed, driven by daily changes in topsoil temperature. For these periods, air sampling from 8:00 to 10:00 and from 18:00 to 20:00 was found to best represent the mean daily N2O flux rates. The wet topsoil conditions caused by irrigation favored the production of N2O from NO3− fertilizers, but not from NH4+ fertilizers, thus indicating that denitrification was the main process causing N2O emissions. It is therefore argued that there is scope for reducing N2O emission from irrigated cotton production; i.e. through the exclusive use of NH4+ fertilizers. Advanced application and irrigation techniques such as subsurface fertilizer application, drip irrigation and fertigation may also minimize N2O emission from this regionally dominant agro-ecosystem.

Organisational culture, change readiness and retention : a human services perspective

The Third Sector is experiencing unprecedented change as nonprofit organisations pursue their mission, organisational excellence and sustainability. This research collected data from employees of Australian nonprofit human service organisations. Instruments to measure organisational culture and change readiness were validated. The relationships between perceptions of organisational cultures, change readiness, job satisfaction and intentions to leave were explored. Findings indicate flexible organisational cultures influence employee attitudes more positively than control cultures. It identified that leaders have a significant role to play in developing and fostering change readiness and job satisfaction. This improves employees' adaptation to change, increases staff retention and organisational sustainability.

The capture and retention evaluation of a stormwater gross pollutant trap design

Gross pollutant traps (GPT) are designed to capture and retain visible street waste, such as anthropogenic litter and organic matter. Blocked screens, low/high downstream tidal waters and flows operating above/below the intended design limits can hamper the operations of a stormwater GPT. Under these adverse operational conditions, a recently developed GPT was evaluated. Capture and retention experiments were conducted on a 50% scale model with partially and fully blocked screens, placed inside a hydraulic flume. Flows were established through the model via an upstream channel-inlet configuration. Floatable, partially buoyant, neutrally buoyant and sinkable spheres were released into the GPT and monitored at the outlet. These experiments were repeated with a pipe-inlet configured GPT. The key findings from the experiments were of practical significance to the design, operation and maintenance of GPTs. These involved an optimum range of screen blockages and a potentially improved inlet design for efficient gross pollutant capture/retention operations. For example, the outlet data showed that the capture and retention efficiency deteriorated rapidly when the screens were fully blocked. The low pressure drop across the retaining screens and the reduced inlet flow velocities were either insufficient to mobilise the gross pollutants, or the GPT became congested.

Development and application of Palygorskite porous ceramsite in a biological aerated filter (BAF)

Novel filter Palygorskite porous ceramsite (PC) was prepared using Palygorskite clay, poreforming material sawdust, and sodium silicate with a mass ratio of 10:2:1 after sintering at 700°C for 180 min. PC was characterized with X-ray diffraction, X-ray fluorescence, scanning electron microscopy, elemental, and porosimetry. PC had a total porosity of 67% and specific surface area of 61 m2/g. In order to assess the usefulness of PC as a medium for biological aerated filters (BAF), PC and (commercially available ceramsite) CAC were used to treat wastewater city in two laboratory-scale upflow BAFs. The results showed that the reactor containing PC was more efficient than the reactor containing CAC in terms of total organic carbon (TOC), ammonia nitrogen (NH3-N), and the removal of total nitrogen (TN) and phosphorus (P). This system was found to be more efficient at water temperatures ranging from 20 to 26°C, an air–water (A/W) ratio of 3:1, dissolved oxygen concentration >4.00 mg/L, and hydraulic retention time (HRT) ranging from 0.5 to 7 h. The interconnected porous structure produced for PC was suitable for microbial growth, and primarily protozoan and metazoan organisms were found in the biofilm. Microorganism growth also showed that, under the same submerged culture conditions, the biological mass in PC was significantly higher than in CAC (34.1 and 2.2 mg TN/g, respectively). In this way, PC media can be considered suitable for the use as a medium in novel biological aerated filters for the simultaneous removal of nitrogen and phosphorus.

Improving retention and graduation of Aboriginal and Torres Strait Islander students in initial teacher education programs

In 2012, the Australian Council of Deans of Education (ACDE), through the Queensland University of Technology, led a MATSITI project focusing on issues related to the retention, support and graduation of Aboriginal and Torres Strait Islander teachers in initial Teacher Education programs across Australia. While some of the barriers that impact on the graduation of Aboriginal and Torres Strait Islander teachers are well, known, this was the first large-scale Australian study to look at the issues nationally and in depth. Thirty-four Teacher Education programs across the country were audited, meetings were held in each state, both Aboriginal and Torres Strait Islander and non-Indigenous Faculty were consulted and approximately 70 Aboriginal and Torres Strait Islander pre-service teachers interviewed. This paper reports on the outcomes of that project, including the evidence that while recruitment into Teacher Education has, in some sites, reached parity, retention rates are well-below expected across the nation. The paper focuses both on the quantitative data and, even more significantly, on the voices of the pre-service teachers themselves, offering insights into the ways forward. As a result of this study, Deans and Heads of School of Teacher Education programs across the country have developed Action Plans alongside their university's Indigenous Higher Education Centres to improve support and retention of Aboriginal and Torres Strait Islander teachers.

Dynamics of nitrogen and suspended solids removal in experimental stormwater biofilters under intermittent wetting and drying

This research study comprehensively analyses the dynamics of nitrogen and suspended solids removal in stormwater biofilters. The study focuses on pollutant removal during an event with time, rather than the conventional event-mean analysis. Antecedent dry days (number of days in between rainfall) during which biofilters remain dry and the inflow concentration of pollutants were two other important variables analysed in this study. The research outcome highlights the significance of dry-phase processes and the process of stabilization on filter performance and sets a paradigm shift from the current approach towards an innovative way of performance analysis of biofilters.

H2 purification by functionalized graphdiyne – role of nitrogen doping

A nitrogen modified graphdiyne is investigated concerning its performance for hydrogen purification from CH4 and CO by density functional theory with dispersion correction and transition state theory. After nitrogen doping, the porous N-graphdiyne nano-mesh shows a reduced H2 diffusion barrier and increased CH4/CO diffusion barriers, hence leading to an enhanced hydrogen purification capability.

The repertoire of nitrogen assimilation in Rhodococcus: Catalysis, pathways and relevance in biotechnology and bioremediation

The Rhodococcus genus exhibits diverse enzymatic activity that can be exploited in the conversion of natural and anthropogenic nitrogenous compounds. This catalytic response provides a selective advantage in terms of available nutrients while also serving to remove otherwise harmful xenobiotics. This review provides a critical assessment of the literature on bioconversion of organo-nitrogen compounds with a consideration of applications in bioremediation and commercial biotechnology. By examining the major nitro-organic compounds (amino acids, amines, nitriles, amides and nitroaromatics) in turn, the considerable repertoire of Rhodococcus spp. is established. The available published enzyme reaction data is coupled with genomic characterisation to provide a molecular basis for Rhodococcus enzyme activity with an assessment of the cellular properties that aid substrate accessibility and ensure stability. The metabolic gene clusters associated with the observed reaction pathways are identified and future directions in enzyme optimisation and metabolic engineering are assessed. © 2014 Society of Chemical Industry.

Removal characteristics of ammonium nitrogen from wastewater by modified Ca-bentonites

A modified inorganic bentonite (Na/Al) based on purified Ca-bentonite was prepared through exchanging Al and Na ions in the interlayer space of Ca-bentonite. The structural properties of purified and modified bentonites were characterized by XRD and SEM analysis. Batch experiments were performed for the adsorption of ammonium nitrogen and different experimental conditions were studied in order to investigate the optimum adsorption conditions. Comparative experiments were also carried out for natural Ca-bentonite (RB), unmodified purified bentonite (PB) and modified purified bentonite (MB). Through the thermodynamic analysis, the ammonium nitrogen adsorption process can be spontaneous, the standard heat was −41.46kJmol −1 , and the adsorption process based on ion exchange adsorption. The ammonium nitrogen adsorption capacity of MB (46.904mg/g) was improved compared to raw bentonite (RB) (26.631mg/g), which was among the highest values of ammonium nitrogen adsorption compared with other adsorbents according to the literatures. The described process provides a potential pathway for the removal of ammonium nitrogen at low concentrations encountered in most natural waters.

Brain activity during the encoding, retention, and retrieval of stimulus representations

Studies of delayed nonmatching-to-sample (DNMS) performance following lesions of the monkey cortex have revealed a critical circuit of brain regions involved in forming memories and retaining and retrieving stimulus representations. Using event-related functional magnetic resonance imaging (fMRI), we measured brain activity in 10 healthy human participants during performance of a trial-unique visual DNMS task using novel barcode stimuli. The event-related design enabled the identification of activity during the different phases of the task (encoding, retention, and retrieval). Several brain regions identified by monkey studies as being important for successful DNMS performance showed selective activity during the different phases, including the mediodorsal thalamic nucleus (encoding), ventrolateral prefrontal cortex (retention), and perirhinal cortex (retrieval). Regions showing sustained activity within trials included the ventromedial and dorsal prefrontal cortices and occipital cortex. The present study shows the utility of investigating performance on tasks derived from animal models to assist in the identification of brain regions involved in human recognition memory.