Tailings Dust Emissions

Fugitive dust emissions from the storage and handling of mine tailings presents environmental and safety concerns, which must be addressed to promote the land sustainability and the health and safety of individuals around a tailings storage facility (TSF). The investigated dust control methods were agglomeration, binder slurry injection, and topical spray. The Dust Busters determined that pelletizing was the most practical method of agglomeration. In order to produce durable pellets from the mine tailings, which consist primarily of silica, a binder must be added. A variety of binders were considered including magnesium and calcium chloride, bentonite, barite, cement, vinyl polymers, acrylic polymers, starch, carboxymethyl cellulose, and a commercial lignosulfonate/bitumen blend. Portland cement proved to be the most effective binder in regards to the pellet’s cost, structural integrity, and longevity. However, due to the abrasive nature of the tailings, pelletizing is not cost effective in comparison to other dust suppression techniques. Binder slurry injection incorporates a pugmill mixer to inject a binding agent into the tailings slurry. Addition of a binder allows the slurry mixture to form a rigid crust that prevents fugitive dust once dried on the existing tailings dam. While the injected slurry is effective at minimizing dust emissions, it is not economically feasible due to high capital costs. The most effective, environmentally safe, and economically feasible solution to reduce the dust associated with tailings storage facilities is a topical spray solution consisting of a vinyl copolymer. The vinyl copolymer, at relatively low concentrations, produces a robust yet permeable crust along the surface of the tailings, which is unmatched in comparison to the other binding agents. By applying the binder as topical solution rather than injecting the binder into the slurry, the capital cost for effective dust suppression is reduced by eliminating the additional process equipment required for both pelletizing and binder slurry injection. Treating 400 acres per year with a vinyl copolymer application costs $110,000. Existing equipment and personnel are adequate to change from the current magnesium chloride treatment to a vinyl copolymer treatment. Current yearly treatments using the magnesium chloride cost approximately$240,000-$720,000 assuming 1-3 applications per year across the 400 acre area; thus changing to a vinyl copolymer treatment will save$130,000-$390,000 per year

The development of a light-weight, long-life diphacinone rodent bait

Ross, J.G., Eason, C.T., Sam, S., Shapiro, L., Blackie, H., MacMorran, D., Aylett, P., Tucker, N., Razzaq, H

Polysubstance-induced relapse of schizoaffective disorder refractory to high-dose antipsychotic medications: a case report

BACKGROUND: The high prevalence of comorbid illicit drug use in persons with chronic psychotic illness represents a strong determinant of psychotic relapse and rehospitalization. Epidemiological studies indicate changing patterns of illicit drug use in Australia, which are concerning because of increased use of crystal methamphetamine, also known as "ice." An important complication of habitual use of crystal methamphetamine is the development of a dose-dependent acute psychotic reaction. We report a case of an acute psychotic relapse in response to polydrug use most notable for multiple recent binges of crystal methamphetamine. Unlike previously described case reports, our patient\u27s acute psychosis was refractory to ultra-high doses of multiple antipsychotic medications. This presented safety challenges due to the risk of serious side effects with high-dose antipsychotic medications.CASE PRESENTATION: A 30-year-old white man with a past history of schizoaffective disorder was brought to our emergency department by the police in a state of extreme agitation, combativeness, and paranoia after use of cannabis and crystal methamphetamine. Despite existing compliance with zuclopenthixol decanoate depot medication, he required multiple emergency injections of zuclopenthixol acetate, and regular high-dose droperidol, chlorpromazine, and lorazepam. However, he remained severely agitated and psychotic with continuous threats of harm to others. A test of antipsychotic drug metabolism by cytochrome P450 enzymes did not reveal a pharmacogenetic cause for the poor therapeutic efficacy of antipsychotic medications. His psychosis did not appear to be modified by psychoactive medications but was instead self-limited to the presence of endogenous methamphetamine within his system. He fully recovered 96 to 120 hours post-presentation and was discharged home with out-patient clinic follow-up.CONCLUSIONS: The current case highlights the challenging nature of a severe psychotic relapse precipitated by illicit substances that is resistant to medical management. High doses of multiple antipsychotic medications may be required to manage dangerous behaviors associated with these acute psychotic relapses. These patients require close monitoring for adverse effects with adjustment of dosing to ensure the optimal balance of risk versus benefit while the patient is acutely psychotic. The results are of relevance for the management of psychiatric emergencies in emergency departments and acute mental health settings

The 2015 Global Climate Legislation Study: a review of climate change legislation in 99 countries: summary for policy-makers

This report summarises the main insights from the 2015 Global Climate Legislation Study. It is the fifth edition in a series dating back to 2010 (Townshend et al., 2011). The 2015 edition covers 98 countries plus the EU, up from 66 in 2014, which together account for 93 per cent of global greenhouse gas emissions. The study is intended as a source of information for legislators, researchers and policy-makers. It is hoped that parliaments considering climate change legislation will benefit from the growing body of experience reflected in the study. Facilitating knowledge exchange among parliamentarians was one of the primary motivations behind the Climate Legislation Study when the series was conceived by the Grantham Research Institute, LSE and GLOBE International in 2010. Since then there have been many examples of parliamentarians learning from, and being inspired by, each other through forums such as GLOBE and the Inter-Parliamentary Union – the two co-sponsors of the 2015 study

Solar Wind Ion Sputtering of Sodium from Silicates Using Molecular Dynamics Calculations of Surface Binding Energies

For nearly 40 yr, studies of exosphere formation on airless bodies have been hindered by uncertainties in our understanding of the underlying ion collisional sputtering by the solar wind (SW). These ion impacts on airless bodies play an important role in altering their surface properties and surrounding environment. Much of the collisional sputtering data needed for exosphere studies come from binary collision approximation (BCA) sputtering models. These depend on the surface binding energy (SBE) for the atoms sputtered from the impacted material. However, the SBE is not reliably known for many materials important for planetary science, such as plagioclase feldspars and sodium pyroxenes. BCA models typically approximate the SBE using the cohesive energy for a monoelemental solid. We use molecular dynamics (MD) to provide the first accurate SBE data we are aware of for Na sputtered from the above silicate minerals, which are expected to be important for exospheric formation at Mercury and the Moon. The MD SBE values are ∼8 times larger than the Na monoelemental cohesive energy. This has a significant effect on the predicted SW ion sputtering yield and energy distribution of Na and the formation of the corresponding Na exosphere. We also find that the SBE is correlated with the coordination number of the Na atoms within the substrate and with the cohesive energy of the Na-bearing silicate. Our MD SBE results will enable more accurate BCA predictions for the SW ion sputtering contribution to the Na exosphere of Mercury and the Moon

Sputtering of Surfaces by Ion Irradiation: A Comparison of Molecular Dynamics and Binary Collision Approximation Models to Laboratory Measurements

We compare various sputtering simulation methods to experimental results in both the low energy (<1 keV) and high energy (≥1 keV) impact regimes for argon ions impacting a pure copper substrate at normal incidence. Our results indicate that for high energy impacts, both binary collision approximation (BCA) and molecular dynamics methods can be used to generate reasonable predictions for the yield and energy distribution of the sputtered atoms. We also find reasonable agreement between the theoretical and experimental results down to impact energies of 600 eV. However, at 200 eV impact energies, significant discrepancies appear between the experimental and theoretical ejecta energy distributions in the peak position, the width of the energy distribution, and the magnitude of the high energy tail. These discrepancies appear to arise from the experimental results being only for atoms sputtered normal to the substrate surface, whereas the theoretical results are integrated over all 2π solid angles above the surface. Using the BCA code SDTrimSP and limiting the results to only atoms emitted within ±15° of the surface normal brings theory and experiment into reasonable agreement. These results suggest that for low energy impacts, the energy distribution of sputtered atoms is highly dependent on the emission angle of the ejecta

Is there a hormonal regulation of phagocytosis at unicellular and multicellular levels? A critical review

Phagocytosis is an ancient cell function, which is similar at unicellular and multicellular levels. Unicells synthesize, store, and secrete multicellular (mammalian) hormones, which influence their phagocytosis. Amino acid hormones, such as histamine, serotonin, epinephrine, and melatonin stimulate phagocytosis, whereas peptide hormones, such as adrenocorticotropic hormone (ACTH), insulin, opioids, arginine vasopressin, and atrial natriuretic peptide decreased it, independently on their chemical structure or function in multicellulars. Macrophage phagocytosis of multicellulars is also stimulated by amino acid hormones, such as histamine, epinephrine, melatonin, and thyroid hormones, however, the effect of peptide hormones is not uniform: prolactin, insulin, glucagon, somatostatin, and leptin have positive effects, whereas ACTH, human chorionic gonadotropin, opioids, and ghrelin have negative ones. Steroid hormones, such as estrogen, hydrocortisone, and dexamethasone are stimulating macrophage phagocytosis, whereas progesterone, aldosterone, and testosterone are depressing it. Considering the data and observations there is not a specific phagocytosis hormone, or a hormonal regulation of phagocytosis neither unicellular, nor multicellular level, however, hormones having specific functions in multicellulars also influence phagocytosis at both levels universally (in unicellulars) or individually (in macrophages). Nevertheless, the hormonal influence cannot be neglected, as phagocytosis (as a function) is rather sensitive to minute dose of hormones and endocrine disruptors. The hormonal influence of phagocytosis by macrophages can be deduced to the events at unicellular level

Prospectus, February 9, 1983

FOCUS ON ARCOLA…; News Digest; 292 vote in election; Pro-file: PS instructor Alan Hartter; More to PM job than fun, travel; New senators thank voters; Weapons are big business; Off-beat comedy set for PC drama team; Students offer suggestions on priorities; \u27Police must be flexible; C-U happenings; Club Notes; Works by Taft on display; Skylines; Plants may be blue; Roses are red; Amish have chosen Arcola area as home; Tourism and manufacturing vital to Arcola\u27s continued growth; Arcola sweeps broom market; NASA footage highlights evening; PBS celebrates Black History Month; Movie fans face heavy dose of déja vu; Guest artists gathered; False sincerity comes across; Future may see change in TV and radio ads; Classified; Holiday busy time for PO; Job seekers can learn; Cardinals proud to be champions; Athletic schedule; Sports junkies take delight in ESPN sports networkhttps://spark.parkland.edu/prospectus_1983/1027/thumbnail.jp