27 research outputs found
Using magnets for particle extraction from powder flow
A model is explored for the extraction of ferromagnetic metallic particles using a magnetic filtration system. These metallic particles, which are transported by a powder flow may be fragments resulting from the standard wear and tear on industrial machinery. A project of this nature was brought to the 2015 Mathematics and Statistics in Industry NZ Study Group. Possible configurations of the magnetic filtration systems are considered with the target of better particle capture. The dependence of the model on the metallic particle's release zone and velocity is investigated. Monte-Carlo simulations are conducted for cases using perpendicular as well as parallel magnetic rods. The results confirm the efficacy of parallel offset rods and emphasise the importance of dense rod placement. The approach could be used to explore further alternative rod arrangements in advance of experimental implementation.
References S.M. Blinder (2011) Magnetic Field of a Cylindrical Bar Magnet Wolfram Demonstrations Project. http://demonstrations.wolfram.com/MagneticFieldOfACylindricalBarMagnet/ J.C. Butcher (2008) Numerical Methods for Ordinary Differential Equations, John Wiley and Sons Ltd., England. H. Cooper, J. Denier, A. Ali, V. Chopovda, A. Gulley (2017) Modelling the effectiveness of magnets in particle extraction, ANZIAM Journal (2017), 57: M332–M352. doi:10.21914/anziamj.v57i0.12037 A. Einstein (1906) Eine neue Bestimmung der Molekuldimensionen, Ann. Phys., 324: 289–306. A. Einstein, R. Furth (1893-1956) Investigations on the theory of the Brownian movement, Dover. isbn=978-0-486-60304-9 Y. Nakai, F. Mishima, Y. Akiyama, S. Nishijima (2010) Development of Magnetic Separation System for Powder Separation, IEEE Transactions on applied superconductivity, 20:3, 941-944. doi:10.1109/TASC.2010.2043086 S. Noguchi, S. Kim (2011) Development of a numerical simulation method for the magnetic separation of magnetic particles, IEEE Transactions on magnetics, 47:5, 898-901. doi:10.1109/CEFC.2010.5481745 A.W. Strandling (1993) The physics of open-gradient dry magnetic separation, International Journal of Mineral Processing, 39, 1-18. doi:10.1016/0301-7516(93)90048-F J. Svoboda, T. Fujita (2003) Recent developments in magnetic methods of material separation, Minerals Engineering, 16, 785-792. doi:10.1016/S0892-6875(03)00212-
Racial/ethnic variation in EBV-positive classical Hodgkin lymphoma in California populations
Epstein-Barr virus (EBV) is detected in the tumor cells of some but not all Hodgkin lymphoma (HL) patients, and evidence indicates that EBV-positive and –negative HL are distinct entities. Racial/ethnic variation in EBV-positive HL in international comparisons suggests etiologic roles for environmental and genetic factors, but these studies used clinical series and evaluated EBV presence by differing protocols. Therefore, we evaluated EBV presence in the tumors of a large (n=1,032), racially and sociodemographically diverse series of California incident classical HL cases with uniform pathology re-review and EBV detection methods. Tumor EBV-positivity was associated with Hispanic and Asian/Pacific Islander (API) but not black race/ethnicity, irrespective of demographic and clinical factors. Complex race-specific associations were observed between EBV-positive HL and age, sex, histology, stage, neighborhood socioeconomic status (SES), and birth place. In Hispanics, EBV-positive HL was associated not only with young and older age, male sex, and mixed cellularity histology, but also with foreign birth and lower SES in females, suggesting immune function responses to correlates of early childhood experience and later environmental exposures, respectively, as well as of pregnancy. For APIs, a lack of association with birth place may reflect the higher SES of API than Hispanic immigrants. In blacks, EBV-positive HL was associated with later-stage disease, consistent with racial/ethnic variation in certain cytokine polymorphisms. The racial/ethnic variation in our findings suggests that EBV-positive HL results from an intricate interplay of early- and later-life environmental, hormonal, and genetic factors leading to depressed immune function and poorly controlled EBV infection
A Genetic Animal Model of Alcoholism for Screening Medications to Treat Addiction
The purpose of this review is to present up-to-date pharmacological, genetic, and behavioral findings from the alcohol-preferring P rat and summarize similar past work. Behaviorally, the focus will be on how the P rat meets criteria put forth for a valid animal model of alcoholism with a highlight on its use as an animal model of polysubstance abuse, including alcohol, nicotine, and psychostimulants. Pharmacologically and genetically, the focus will be on the neurotransmitter and neuropeptide systems that have received the most attention: cholinergic, dopaminergic, GABAergic, glutamatergic, serotonergic, noradrenergic, corticotrophin releasing hormone, opioid, and neuropeptide Y. Herein, we sought to place the P rat's behavioral and neurochemical phenotypes, and to some extent its genotype, in the context of the clinical literature. After reviewing the findings thus far, this chapter discusses future directions for expanding the use of this genetic animal model of alcoholism to identify molecular targets for treating drug addiction in general
Bedrock geology of DFDP-2B, central Alpine Fault, New Zealand
<p>During the second phase of the Alpine Fault, Deep Fault Drilling Project (DFDP) in the Whataroa River, South Westland, New Zealand, bedrock was encountered in the DFDP-2B borehole from 238.5–893.2 m Measured Depth (MD). Continuous sampling and meso- to microscale characterisation of whole rock cuttings established that, in sequence, the borehole sampled amphibolite facies, Torlesse Composite Terrane-derived schists, protomylonites and mylonites, terminating 200–400 m above an Alpine Fault Principal Slip Zone (PSZ) with a maximum dip of 62°. The most diagnostic structural features of increasing PSZ proximity were the occurrence of shear bands and reduction in mean quartz grain sizes. A change in composition to greater mica:quartz + feldspar, most markedly below c. 700 m MD, is inferred to result from either heterogeneous sampling or a change in lithology related to alteration. Major oxide variations suggest the fault-proximal Alpine Fault alteration zone, as previously defined in DFDP-1 core, was not sampled.</p
Petrophysical, Geochemical, and Hydrological Evidence for Extensive Fracture-Mediated Fluid and Heat Transport in the Alpine Fault's Hanging-Wall Damage Zone
International audienceFault rock assemblages reflect interaction between deformation, stress, temperature, fluid, and chemical regimes on distinct spatial and temporal scales at various positions in the crust. Here we interpret measurements made in the hanging‐wall of the Alpine Fault during the second stage of the Deep Fault Drilling Project (DFDP‐2). We present observational evidence for extensive fracturing and high hanging‐wall hydraulic conductivity (∼10−9 to 10−7 m/s, corresponding to permeability of ∼10−16 to 10−14 m2) extending several hundred meters from the fault's principal slip zone. Mud losses, gas chemistry anomalies, and petrophysical data indicate that a subset of fractures intersected by the borehole are capable of transmitting fluid volumes of several cubic meters on time scales of hours. DFDP‐2 observations and other data suggest that this hydrogeologically active portion of the fault zone in the hanging‐wall is several kilometers wide in the uppermost crust. This finding is consistent with numerical models of earthquake rupture and off‐fault damage. We conclude that the mechanically and hydrogeologically active part of the Alpine Fault is a more dynamic and extensive feature than commonly described in models based on exhumed faults. We propose that the hydrogeologically active damage zone of the Alpine Fault and other large active faults in areas of high topographic relief can be subdivided into an inner zone in which damage is controlled principally by earthquake rupture processes and an outer zone in which damage reflects coseismic shaking, strain accumulation and release on interseismic timescales, and inherited fracturing related to exhumation
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Modelling the effectiveness of magnets in particle extraction
We develop a computational model to simulate the effective capture of metallic particles in industrial processes through the use of magnetic filtration systems, where these metallic particles are fragments resulting from the standard wear and tear on the machinery itself. This work is an explorative step in developing a full analytic model to better understand both the strengths and limits of such systems.
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Initialising finisher gaps in a hot strip mill
In the late stages of steel production in the New Zealand Steel hot strip mill, the sheets pass through a series of four pairs of rollers that squeeze the metal to the required thickness. The gaps between the pairs of rollers are controlled by controllers based upon a combination of models with feedback from measurements. New Zealand Steel brought a project to consider this process to the 2016 Mathematics-in-Industry New Zealand Study Group. The lines of investigation described include mathematical models based on the physics of the process, which have identified the primary parameters affecting steel processing between the rollers; and statistical analysis of data provided, revealing that the present electronic controllers improve target gauge over time. The first few metres of a strip are often outside acceptable thickness limits after going through the rollers. We diagnose likely causes and suggest possible cures.
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