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Build systems are used to transform static source code into executable software. They play a crucial role in modern software development and maintenance. As such, much research effort has been invested in understanding the quality and evolution of build systems, including Apache ANT, Apache Maven, and Make‐based ones. However, the quality and evolution of build systems for mobile apps, such as on the Android platform, have not as yet been investigated in detail. Mobile app development, and the Android development context in particular, impose unique constrains, such as different device conditions and capabilities. It presents unique challenges, such as frequently upgraded Android frameworks, which those who implement and maintain build systems must tackle. In this paper, we present an exploratory empirical study of the build systems of 5222 Android projects to better understand their quality and evolution. We (a) study the build technology choices that Android developers make (Gradle being recommended and the most popular choice), (b) explore the sustainability of the official Gradle build system (parts of build files are updated more frequent that others and the update of the special Gradle plugin would induce unrecommended configurations), and (c) analyze the quality of Gradle scripts for Android apps—more than a half of the open‐source Android apps cannot be successfully built due to five common root causes. [ABSTRACT FROM AUTHOR]

Food security depends on sustainable phosphorus (P) fertilisers, which at present are mostly supplied from a finite rock phosphate source. Phosphate (PO43−) and ammonium (NH4+) in dairy processing wastewater can be recovered as struvite (Mg + NH4+ + PO43− 6H20), a nutrient rich mineral for fertiliser application. The objectives of this study were to (1) quantify the effects of, pH, temperature and Mg: PO43− dosing rates on nutrient (PO43− and NH4+) removal and struvite precipitation from post anaerobic digested dairy processing wastewater, and (2) co-blend different dairy processing wastewaters to improve the reactant stoichiometry of NH4+ and PO43− for optimal struvite recovery and NH4+ removal. Phosphate removal (>90%) and struvite production (>60%) was achieved across a range of synthesis conditions, and was significantly impacted by pH as determined by response surface modelling. A combination of disproportionate molar ratios of PO43− and NH4+, presence of calcium and the apparent mineralisation of organic N, resulted in co-precipitation of hydroxyapatite and elevated levels of residual aqueous NH4+. In the second phase of this study, struvite was successfully precipitated and NH4+ removal was improved (~17%) however, higher concentrations of calcium in the wastewater blends resulted in greater hydroxyapatite co-precipitation (up to 30%). While struvite was the desired product in this study the formation of multiple heterogenous P-rich products (struvite and hydroxyapatite) has the potential to improve P recovery from dairy processing wastewaters and produce a fertiliser blend with amenity and value in agricultural systems. [ABSTRACT FROM AUTHOR]

The recovery of phosphorus (P) from milk processing flotation sludges (MFS) using pyrolysis can contribute to a sustainable reuse of P by converting waste to fertiliser. The objectives of this study were to quantify the recovery and transformation of P following MFS pyrolysis and compare the efficacy of raw and pyrolysed MFS as organic P fertilisers. Phosphorus retention in biochars was high (98 ± 0.73% yield), leading to the enrichment of P relative to the raw MFS by a factor of 4.3–4.5. Pyrolysis of the MFS at 450 °C led to a 3-fold increase in the proportion of P in the HCl-extractable fraction (65 ± 0.32%), a 2-fold reduction in NaOH-P (30 ± 2.1%), and negligible amounts of P in the H2O-P and NaHCO3-P fractions. The bioavailability of P in raw MFS and 450 °C biochar was compared to a soluble P fertiliser in P-limiting plant bioassays. In the short-term (70 day) trial where ryegrass was grown on three soil types (Arenosol, Vertisol or Ferralsol), biochar MFS showed higher efficacy as a P fertiliser than raw MFS in the acidic Ferralsol, whereas the opposite response was observed in the near-neutral Arenosol. In the Vertisol, neither the raw MFS nor biochar produced more cumulative biomass or P uptake than any of the nil P controls. Over a longer 200-day period, raw MFS and biochar applied to the Arenosol were about 20% as efficient at providing P to ryegrass plants as the water-soluble K2PO4, suggesting that higher application rates of MFS or biochar would be required to match synthetic fertilisers in the short term. [ABSTRACT FROM AUTHOR]

Background and aims: Hydrothermal carbonisation (HTC) is an alternative thermochemical method for conversion of waste to carbonised material. HTC converts high moisture biomass into hydrochar, with substantially lower energy inputs than pyrolysis since pre-drying is not required. Hydrochar is increasingly being proposed as a soil amendment; however, hydrochar addition to soils has inconsistent effects on germination and plant growth. Here, we aggregated hydrochar-plant studies to ascertain the effect of hydrochar on plant production. Method: Using meta-analysis, data from 43 published articles with 437 pairwise comparisons was synthesised to investigate the effect of hydrochar on seed germination or plant growth, and the driving factors. Results: On average, hydrochar application significantly reduced both seed germination (-38 %) and shoot biomass (-10 %) across hydrochar properties and experimental conditions. Negative impacts of hydrochar on seed germination and shoot biomass were greatest when application rates of hydrochar were above 11 t/ha (for all feedstocks except woody biomass) and 16 t/ha, respectively. At a standardised application rate of 10 t/ha, unmodified sewage sludge, animal manure and green waste hydrochars had a significant negative effect on germination, whilst food waste and woody hydrochars had no effect. Importantly, modification of hydrochar to lower toxin content significantly mitigated the negative effect on both shoot biomass and germination. Conclusions: Findings provide a basis for further research to elucidate mechanisms leading to the different plant responses following hydrochar application. Fundamentally, interactions among hydrochar dose, properties and edaphic variables are essential to understand when and where benefits may be achieved. [ABSTRACT FROM AUTHOR]

As dairy industries increase across Australia, the amount of dairy waste is also on the rise. Australia annually production stands at around 377 727 t of cheese, 273 425 t of milk powder and 92 698 t of butter, and it is the third largest exporter of milk. The waste produced by these industries is considered a potentially valuable resource, and an environmental pollutant if not appropriately managed. The focus of this review is to evaluate the potential of converting typical Australian dairy industry waste into sustainable energy. Five fundamental methods including transesterification, pyrolysis, anaerobic digestion, steam reforming, and hydrothermal carbonization are discussed. Their technological merits, demerits and adaptability from the perspective of Australia are examined. The properties of representative wastes are also considered for the different energy conversion processes. This review aims to highlight the potential use of dairy industry wastes as feedstock for the emerging renewable energy sector. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Cotton gin trash (CGT), a waste product of cotton gins, make up about 10% of each bale of cotton bolls ginned. The current study investigates high value volatile compounds in CGT to add value to this by-product. The volatile compounds in CGT and different parts of the cotton plant were extracted using various methods, identified by gas chromatography-mass spectrometry (GC-MS) or nuclear magnetic resonance (NMR) spectroscopy, and then quantified by gas chromatography-flame ionisation detection (GC-FID) against available standards. Terpenoids including monoterpenoids and sesquiterpenoids were found to be the most abundant, making up 64.66% (area under peak) of total volatiles extracted by hydro-distillation. The major extractable terpenoids in CGT were α-pinene (13.69–23.05 μg/g), β-caryophyllene (3.99–74.32 μg/g), α-humulene (2.00–25.71 μg/g), caryophyllene oxide (41.50–102.08 μg/g) and β-bisabolol (40.05–137.32 μg/g). Recoveries varied between different extraction methods. The terpenoids were found to be more abundant in the calyx (659.12 μg/g) and leaves (627.72 μg/g) than in stalks (112.97 μg/g) and stems (24.24 μg/g) of the cotton plant, indicating the possible biological origin of CGT volatiles. This study is the first to identify and quantify the different terpenoids present in CGT and significantly, β-bisabolol, an abundant compound (sesquiterpene alcohol) which may have valuable biological prospects. These findings therefore contribute to identifying alternative management strategies and uses of CGT. [ABSTRACT FROM AUTHOR]

Predicting the required time to fix an issue (i.e., a new feature, bug fix, or enhancement) has long been the goal of many software engineering researchers. However, after an issue has been fixed, it must be integrated into an official release to become visible to users. In theory, issues should be quickly integrated into releases after they are fixed. However, in practice, the integration of a fixed issue might be prevented in one or more releases before reaching users. For example, a fixed issue might be prevented from integration in order to assess the impact that this fixed issue may have on the system as a whole. While one can often speculate, it is not always clear why some fixed issues are integrated immediately, while others are prevented from integration. In this paper, we empirically study the integration of 20,995 fixed issues from the ArgoUML, Eclipse, and Firefox projects. Our results indicate that: (i) despite being fixed well before the release date, the integration of 34% to 60% of fixed issues in projects with traditional release cycle (the Eclipse and ArgoUML projects), and 98% of fixed issues in a project with a rapid release cycle (the Firefox project) was prevented in one or more releases; (ii) using information that we derive from fixed issues, our models are able to accurately predict the release in which a fixed issue will be integrated, achieving Areas Under the Curve (AUC) values of 0.62 to 0.93; and (iii) heuristics that estimate the effort that the team invests to fix issues is one of the most influential factors in our models. Furthermore, we fit models to study fixed issues that suffer from a long integration time. Such models, (iv) obtain AUC values of 0.82 to 0.96 and (v) derive much of their explanatory power from metrics that are related to the release cycle. Finally, we train regression models to study integration time in terms of number of days. Our models achieve R2 values of 0.39 to 0.65, and indicate that the time at which an issue is fixed and the resolver of the issue have a large impact on the number of days that a fixed issue requires for integration. Our results indicate that, in addition to the backlog of issues that need to be fixed, the backlog of issues that need to be released introduces a software development overhead, which may lead to a longer integration time. Therefore, in addition to studying the triaging and fixing stages of the issue lifecycle, the integration stage should also be the target of future research and tooling efforts in order to reduce the time-to-delivery of fixed issues. [ABSTRACT FROM AUTHOR]

Although cultivated for over 7000 years, mainly for production of cotton fibre, the cotton plant has not been fully explored for potential uses of its other parts. Despite cotton containing many important chemical compounds, limited understanding of its phytochemical composition still exists. In order to add value to waste products of the cotton industry, such as cotton gin trash, this review focuses on phytochemicals associated with different parts of cotton plants and their biological activities. Three major classes of compounds and some primary metabolites have been previously identified in the plant. Among these compounds, most terpenoids and their derivatives (51), fatty acids (four), and phenolics (six), were found in the leaves, bolls, stalks, and stems. Biological activities, such as anti-microbial and anti-inflammatory activities, are associated with some of these phytochemicals. For example, β-bisabolol, a sesquiterpenoid enriched in the flowers of cotton plants, may have anti-inflammatory product application. Considering the abundance of biologically active compounds in the cotton plant, there is scope to develop a novel process within the current cotton fibre production system to separate these valuable phytochemicals, developing them into potentially high-value products. This scenario may present the cotton processing industry with an innovative pathway towards a waste-to-profit solution. [ABSTRACT FROM AUTHOR]

The widespread deployment of commercial-scale cellulosic ethanol currently hinges on developing and evaluating scalable processes whilst broadening feedstock options. This study investigates whole Eucalyptus grandis trees as a potential feedstock and demonstrates dilute acid pre-treatment (with steam explosion) followed by pre-saccharification simultaneous saccharification fermentation process ( PSSF) as a suitable, scalable strategy for the production of bioethanol. Biomass was pre-treated in dilute H2SO4 at laboratory scale (0.1 kg) and pilot scale (10 kg) to evaluate the effect of combined severity factor ( CSF) on pre-treatment effectiveness. Subsequently, pilot-scale pre-treated residues (15 wt.%) were converted to ethanol in a PSSF process at 2 L and 300 L scales. Good polynomial correlations (n = 2) of CSF with hemicellulose removal and glucan digestibility with a minimum R2 of 0.91 were recorded. The laboratory-scale 72 h glucan digestibility and glucose yield was 68.0% and 51.3%, respectively, from biomass pre-treated at 190 °C /15 min/ 4.8 wt.% H2SO4. Pilot-scale pre-treatment (180 °C/ 15 min/2.4 wt.% H2SO4 followed by steam explosion) delivered higher glucan digestibility (71.8%) and glucose yield (63.6%). However, the ethanol yields using PSSF were calculated at 82.5 and 113 kg/ton of dry biomass for the pilot and the laboratory scales, respectively. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]