Outotec (Canada)

Fecal samples are highly complex and heterogeneous, containing materials at various stages of digestion. The heterogeneity and complexity of feces make stool metabolomics inherently challenging. The level of homogenization influences the outcome of the study, affecting the metabolite profiles and reproducibility; however, there is no consensus on how fecal samples should be prepared to overcome the topographical discrepancy and obtain data representative of the stool as a whole. Various combinations of homogenization conditions were compared to investigate the effects of bead size, addition of solvents and the differences between wet-frozen and lyophilized feces. The homogenization parameters were systematically altered to evaluate the solvent usage, bead size, and whether lyophilization is required in homogenization. The metabolic coverage and reproducibility were compared among the different conditions. The current work revealed that a combination of mechanical and chemical lysis obtained by bead-beating with a mixture of big and small sizes of beads in an organic solvent is an effective way to homogenize fecal samples with adequate reproducibility and metabolic coverage. Lyophilization is required when bead-beating is not available. A comprehensive and systematical evaluation of various fecal matter homogenization conditions provides a profound understanding for the effects of different homogenization methods. Our findings would be beneficial to assist with standardization of fecal sample homogenization protocol.

Historically, strength development in underground backfill is estimated based on the results of historic unconfined compressive strength (UCS) testing. During both preliminary study phases and operational phases are batched to specific solids and binder contents and placed in curing chambers, with the intention that these chambers replicate the curing conditions experienced underground. The rate of strength development in mining backfill can be greatly affected by variations in environmental factors including temperature & humidity. Therefore accurate representation of in situ curing conditions for cemented specimens is crucial. This paper investigates the effect that differing curing conditions can have on the strength development of cemented mine backfill specimens. This paper explores how variations expected to be encountered in typical fill masses impacts the resulting strengths and also investigates how aspects that may appear subtle can actually have a significant impact on the resulting measured strengths. Given the findings of this investigation a series of recommendations are provided for improving the way mine backfill curing chambers are managed.

ABSTRACTProofreading polymerases have 3’ to 5’ exonuclease activity that allows the excision and correction of mis-incorporated bases during DNA replication. In a previous study, we demonstrated that in addition to correcting substitution errors and lowering the error rate of DNA amplification, proofreading polymerases can also edit PCR primers to match template sequences. Primer editing is a feature that can be advantageous in certain experimental contexts, such as amplicon-based microbiome profiling. Here we develop a set of synthetic DNA standards to report on primer editing activity and use these standards to dissect this phenomenon. The primer editing standards allow next-generation sequencing-based enzymological measurements, reveal the extent of editing, and allow the comparison of different polymerases and cycling conditions. We demonstrate that proofreading polymerases edit PCR primers in a concentration-dependent manner, and we examine whether primer editing exhibits any sequence specificity. In addition, we use these standards to show that primer editing is tunable through the incorporation of phosphorothioate linkages. Finally, we demonstrate the ability of primer editing to robustly rescue the drop-out of taxa with 16S rRNA gene-targeting primer mismatches using mock communities and human skin microbiome samples.

ABSTRACTBackgroundSARS-CoV-2 causes significant morbidity and mortality in health care settings. Our understanding of the distribution of this virus in the built healthcare environment and wastewater, and relationship to disease burden, is limited.MethodsWe performed a prospective multi-center study of environmental sampling of SARS-CoV-2 from hospital surfaces and wastewater and evaluated their relationships with regional and hospital COVID-19 burden. We developed and validated a qPCR-based approach to surface sampling, and swab samples were collected weekly from different locations and surfaces across two tertiary care hospital campuses for a 10-week period during the pandemic, along with wastewater samples.ResultsOver a 10-week period, 963 swab samples were collected and analyzed. We found 61 (6%) swabs positive for SARS-CoV-2, with the majority of these (n=51) originating from floor samples. Wards that actively managed patients with COVID-19 had the highest frequency of positive samples (p<0.01). Detection frequency in built environment swabs was significantly associated with active cases in the hospital throughout the study (p<0.025). Wastewater viral signal changes appeared to predate change in case burden.ConclusionsEnvironment sampling for SARS-CoV-2, in particular from floors, may offer a unique and resolved approach to surveillance of COVID-19.

Industry 4.0 and digitalization are common themes in aluminium producers’ strategies. However, the actual penetration of such applications varies and there is a lack of common terminology. In this article, we first establish a framework around different types of applications seen in the aluminium industry, specifically the carbon area, consisting of:

Abstract This study examined the impact of changing the secondary disinfectant from chlorine to a stabilized hydrogen peroxide (SHP) in three full‐scale drinking water treatment plants serving small communities in the provinces of Ontario and Newfoundland, Canada. In all three communities, the SHP residuals were maintained within the limits specified by local regulators, with the exception of one of the sites in Newfoundland, where residuals were outside these limits on several occasions during the study. Following the transition to the SHP system, total coliforms and Escherichia coli consistently tested negative (nondetected) in all cases. Switching to the SHP system reduced concentrations of total trihalomethanes to 22–44 μg/L and total haloacetic acids to 47–70 μg/L, corresponding to 72 ± 9 and 67 ± 11% reductions, respectively. The present study indicated that changing the secondary disinfectant to SHP did not negatively affect the polyvinyl chloride and ductileiron pipes in the distribution systems studied.

Corvin Castle, located in Hunedoara County (Transylvania), is an important Romanian cultural site. Originally, a fort constructed in the 14th century, it was first converted into a castle by Ioan de Hunedoara in the 15th century, frequently changing owners (with significant construction in the 15th and 17th centuries) until it was abandoned in the mid-19th century. After undergoing various ill-fated reconstruction efforts in the late 19th century, the castle reopened in the 1950s when the Romanian government renewed its interest in cultural sites and undertook a series of sparsely-documented archaeological investigations and conservation projects. Presently, restoration efforts require renewed investigation of Corvin Castle’s construction and history. Ground penetrating radar (GPR) is a promising tool for investigating the construction phases of heritage structures like Corvin Castle, where invasive methods are inappropriate and extensive historical modification has left incomplete records. In 2017, a comprehensive GPR survey of the castle was conducted. The survey recognizes features mentioned in texts, discovers previously unknown constructions, locates areas of moisture ingress around the courtyard, and identifies the extent and composition of the building foundations. Information gained from these scans, especially combined with printed sources, is an asset in planning restoration efforts and understanding the effects of past modifications.

Abstract A systematic study of various temporary and permanent clay stabilizers was conducted with assorted binary blends of bentonite and silica flour. A specific stabilizer's performance is directly correlated to the type and loading of the inhibitor and particular ratio of existing inorganic substrate. Results exhibited high performance correlation; response surface general topography is dependent upon the temporary or permanent characteristics of the stabilizer. Studies comprised combined mixture, single numeric, optimal, design of experiment and performance test data gathering utilizing a low-pressure fluid loss cell. A predetermined concentration of unadulterated sodium bentonite and 325-mesh silica flour were blended into water at a specific RPM and duration in the presence of a particular stabilizer then placed into a the cell, sealed, and pressure was applied. Increased Darcy leak off slope values are reliable, accurate indicators of increased stabilizer performance thus each slope was calculated and plotted versus stabilizer dosage and inorganic substrate ratio. KCl was studied from 0 to 8 weight percent and used as a comparative guide for all stabilizers tested with the balance tested in their "as is" state from 0.0 to 2.0 gallons per thousand gallons. Temporary stabilizers typically provided a consistent topography with respect to performance, with a 20/80 bentonite/ silica flour ratio yielding the highest performance. Bimodal maximum performance inorganic ratios were present for permanent stabilizers tested. KCl dosage offset lab results correlate well with reported field application results. At higher stabilizer loadings superior performance relative to KCl was evident. Traditionally clay stabilizer selection is based upon Capillary Suction Time and Roller Oven testing methods. This alternate bentonite and silica flour comprehensive matrix clay stabilizer selection method is consistent, continuous, portable, field friendly and applicable over a wide range of stabilizer and variable inorganic matrix types.

Abstract Stainless steels are characterized as having relatively poor wear resistance and tribological properties, but they are often required for a particular application because of their corrosion resistance. This article describes the classification of stainless steels and wear. Stainless steels have been classified by microstructure and are categorized as austenitic, martensitic, ferritic, or duplex. The main categories of wear are related to abrasion, erosion, adhesive wear, and surface fatigue. The article presents a list that proposes the alloy family that could be the optimal selection for a particular wear mode. The corrosion modes include dry sliding, tribocorrosion, erosion, erosion-corrosion, cavitation, dry erosion, erosion-oxidation, galling and fretting.