21 research outputs found
Basic comparison of particle size distribution measurements of pigments and fillers using commonly available industrial methods
The Nanobiosciences Unit of the Joint Research Centreâs Institute for Health and Consumer Protection and Eurocolour, the association of European pigments, dyes and fillers industry, have carried out a program of work to evaluate a number of instrumental methods of measuring particle size distributions as required for assessing compliance versus the EU Recommendation for the definition on nanomaterials. The study has examined the use of five instrumental methods applied to a range of eight widely different but industrially relevant powder pigments. The techniques examined were Laser Diffraction (LD), Dynamic Light Scattering (DLS), Centrifugal Liquid Sedimentation (CLS), Volume Specific Surface Area (VSSA) and Electron Microscopy (EM).
This report describes the materials studied and the preparative and analytical methods used. Individual chapters provide an overview of the single analytical methods used together with a summary of the results obtained using each particular method. In considering the results of this study it is important to note that the aim was not to determine the optimum conditions for every individual sample but rather to produce and evaluate data which could be considered representative of that obtainable in industrial laboratories using existing instrumental facilities operated by experienced but not specialised operators. The report discusses the challenges of using these instrumental methods to obtain a simple unambiguous classification of the test materials according to the EC definition.JRC.I.4-Nanobioscience
Breakthrough Energy Savings with Waterjet Technology
Experiments performed at the University of Missouri-Rolla's Waterjet Laboratory have demonstrated clearly the ability of waterjets to disaggregate, in a single step, four different mineral ores, including ores containing iron, lead and copper products. The study focused mainly on galena-bearing dolomite, a lead ore, and compared the new technology with that of traditional mining and milling to liberate the valuable constituent for the more voluminous host rock. The technical term for the disintegration of the ore to achieve this liberation is comminution. The potential for energy savings if this process can be improved, is immense. Further, if this separation can be made at the mining face, then the potential energy savings include avoidance of transportation (haulage and hoisting) costs to move, process and store this waste at the surface. The waste can, instead, be disposed into the available cavities within the mine. The savings also include the elimination of the comminution, crushing and grinding, stages in the processing plant. Future prototype developments are intended to determine if high-pressure waterjet mining and processing can be optimized to become cheaper than traditional fragmentation by drilling and blasting and to optimize the separation process. The basic new mining process was illustrated in tests on two local rock types, a low-strength sandstone with hematite inclusions, and a medium to high-strength dolomite commonly used for construction materials. Illustrative testing of liberation of minerals, utilized a lead-bearing dolomite, and included a parametric study of the optimal conditions needed to create a size distribution considered best for separation. The target goal was to have 50 percent of the mined material finer than 100 mesh (149 microns). Of the 21 tests that were run, five clearly achieved the target. The samples were obtained as run-of-mine lumps of ore, which exhibited a great deal of heterogeneity within the samples. This, in turn, reduced the ability to apply detailed statistical tests to the product outcomes. Nonetheless, a regression analysis showed that operating pressures between 105 (10,000psi) and 140 (15,000psi) MegaPascals (MPa) at traverse speeds no greater than 10 cm/min (4 in/min), best generated the target result. Variation in other parameters, rotation speed, nozzle diameter, and nozzle separation angle, during the preliminary tests did not substantially change the product, and so were kept fixed during the ore mining tests. The experimental protocols were developed to include proper treatment of the lead-bearing materials, which may be considered hazardous. In anticipation of the creation of a mineral processing design for separation of the concentrates from the tailings (waste), assays were made of the metal content of each screen size for each of the 21 runs; with three screens and a pan for undersize, to give a total of 84 assays. This information will enable Dr. McNulty, project consultant, to create a flow sheet for the prototype mining machine. As a preliminary component to such a system, the experimental layout included a product-recovery system that delivered all of the fragmented product to the nest of screens which allowed study of the liberation at the different size levels. Where incomplete liberation is found, a secondary process was demonstrated for using pressurized cavitation to further comminute the material. This concept was successfully demonstrated, with a small cavitation chamber illustrating the much smaller space that such a tool requires, relative to conventional ball and rod mills. Additional testing is ongoing, external to this program, to find whether an one-step process using higher jet pressures and longer dwell times to achieve all the required comminution in mining, is more efficient than a two-step process in which normal jet pressures and feed rates do the initial mining, but full particle liberation is achieved only through secondary processing of the product in a cavitation chamber. Subsequent testing is also planned, to determine preferred methods for separating ore minerals from the waste. Tests with this system have included both the galena samples, and copper ores from Poland. The development of this tool lies within an expanding market for the use of high-pressure waterjet equipment across a broad spectrum of applications. As the industry develops new tools, it is anticipated that the research team will investigate the development of a prototype machine based on these tools, since this will simplify and speed up equipment development. It is hoped that once this is developed that can be taken into an active mine. Such a machine should be able to produce large enough samples to allow assessment of optimal operating conditions
The Grizzly, November 1, 1985
Exploring Faculty/Student Research Opportunities âą Dean Muench: An Expert on RA Supervision âą Letters: No More Roving Reporter Complaints, Please; J. Board Decision Not Seen as Fair; Campus Social Life Taking a Left Turn âą Editorial: Discontent is in the Air âą In Search of Success: Vanessa Embarks on her Career âą Liberal Arts and Science to be Discussed on Founder\u27s Day âą Loss to Penn State Works Against the Bears âą Grizzlies Prepare for Make or Break Game vs. Mules âą Harriers Race Into Autumn âą Philadelphia Sports: Frustrating Times âą Soccer Team Ties a Few âą Athlete of the Week: Steve Coulter âą College Campaign Launched âą Tuition: An Ever-Increasing Problem âą Exercise to Release Stress âą Medical Schools Suffering âą Ursinus Aid to Mexico âą Alcohol and Advertising âą Open Dialog Interaction: Jerry Falwell in Politics; Protecting America âą Natural Science Perspectives âą New Course Offerings: Argument and Debate; East Asian Literature and Politics âą Reimert Task Force Means Law and Order, of Coursehttps://digitalcommons.ursinus.edu/grizzlynews/1150/thumbnail.jp
COSORE: A community database for continuous soil respiration and other soilâatmosphere greenhouse gas flux data
Globally, soils store two to three times as much carbon as currently resides in the atmosphere, and it is critical to understand how soil greenhouse gas (GHG) emissions and uptake will respond to ongoing climate change. In particular, the soilâtoâatmosphere CO2 flux, commonly though imprecisely termed soil respiration (RS), is one of the largest carbon fluxes in the Earth system. An increasing number of highâfrequency RS measurements (typically, from an automated system with hourly sampling) have been made over the last two decades; an increasing number of methane measurements are being made with such systems as well. Such high frequency data are an invaluable resource for understanding GHG fluxes, but lack a central database or repository. Here we describe the lightweight, openâsource COSORE (COntinuous SOil REspiration) database and software, that focuses on automated, continuous and longâterm GHG flux datasets, and is intended to serve as a community resource for earth sciences, climate change syntheses and model evaluation. Contributed datasets are mapped to a single, consistent standard, with metadata on contributors, geographic location, measurement conditions and ancillary data. The design emphasizes the importance of reproducibility, scientific transparency and open access to data. While being oriented towards continuously measured RS, the database design accommodates other soilâatmosphere measurements (e.g. ecosystem respiration, chamberâmeasured net ecosystem exchange, methane fluxes) as well as experimental treatments (heterotrophic only, etc.). We give brief examples of the types of analyses possible using this new community resource and describe its accompanying R software package
Genomic epidemiology of SARS-CoV-2 in a UK university identifies dynamics of transmission
AbstractUnderstanding SARS-CoV-2 transmission in higher education settings is important to limit spread between students, and into at-risk populations. In this study, we sequenced 482 SARS-CoV-2 isolates from the University of Cambridge from 5 October to 6 December 2020. We perform a detailed phylogenetic comparison with 972 isolates from the surrounding community, complemented with epidemiological and contact tracing data, to determine transmission dynamics. We observe limited viral introductions into the university; the majority of student cases were linked to a single genetic cluster, likely following social gatherings at a venue outside the university. We identify considerable onward transmission associated with student accommodation and courses; this was effectively contained using local infection control measures and following a national lockdown. Transmission clusters were largely segregated within the university or the community. Our study highlights key determinants of SARS-CoV-2 transmission and effective interventions in a higher education setting that will inform public health policy during pandemics.</jats:p
The individualisation of glycaemic targets in response to patient characteristics in type 2 diabetes: a scoping review
BACKGROUND: Evidence and guidelines increasingly support an individualised approach to care for people with type 2 diabetes and individualisation of glycaemic targets in response to patient factors. METHODS: We undertook a scoping review of the literature for evidence of factors impacting upon glycated haemoglobin target individualisation in adults with type 2 diabetes. Data were analysed thematically with the themes inductively derived from article review. FINDINGS: Evidence suggests that presence of cardiovascular disease, hypoglycaemia unawareness, severe hypoglycaemia, limited life expectancy, advanced age, long diabetes duration, frailty, cognitive impairment, disability, extensive comorbidity, diabetes distress and patient preference should inform the setting of glycaemic targets. CONCLUSION: The management of people with diabetes is complex. In clinical practice, many patients will have a variety of factors that should be considered when personalising their care. Approaches to personalised care and glycaemic treatment targets should be undertaken as part of a shared decision-making process between physician and patient. Use of electronic records might enable greater efficiency and more widespread use of personalised care plans for people with diabetes
Explicit glycated haemoglobin goals improve subsequent HbA1c levels with no impact on health-related quality of life.
Background: National guidelines recognise the importance of individualising HbA1c targets. Many people with diabetes agree to have their targets re-evaluated in consultations in response to specific characteristics.Aims: We aimed to evaluate the impact of relaxed or stretch HbA1c goals on subsequent HbA1c levels and health-related quality of life (HR-QoL) in adults with diabetes.Methods: We randomised 50 adults with diabetes to receive HbA1c targets either 5mmol/mol above (relaxed target) or 5mmol/mol below (stretch target) current HbA1c readings for 3 months. Participants' HbA1c levels and HR-QoL according to the Euro-QoL-5D-5L (EQ-5D-5L) validated questionnaire were measured at baseline and endpoint. EQ-5D-5L outputs HR-QoL scores (EQ-5D index, rangeâââ0.594â1.000, higher is better) and numerical values from a visual analogue scale (EQ-VAS, range 0â100, higher is better).Results: Thirty-three individuals completed endpoint evaluation. Sulphonylurea and metformin usage increased 3%. Thiazolidinedione, DPP-4 inhibitor, SGLT-2 inhibitor, GLP-1 receptor agonist, and insulin usage remained unchanged. Mean HbA1c improved by 2.9mmol/mol (95% CI -0.4â6.2,p = 0.084) in those with relaxed targets and 2.8mmol/mol (95% CI -0.2â5.7,p = 0.065) with stretch targets. There was no change in median EQ-5D index or EQ-VAS in those with relaxed targets. Median EQ-5D index worsened by 0.005 and EQ-VAS improved by 5 with stretch targets.Conclusions: Our findings suggest goal-setting using specific HbA1c targets is associated with improved HbA1c levels irrespective of the target. Median change in EQ-5D-5L scores were below the threshold of minimum clinically important difference. This may indicate the target-setting process, rather than the goal itself, is beneficial for patient HbA1c levels. Further studies are needed to evaluate these findings in greater detail