Slag ladle insulation

Slag from Pasminco's lead-zinc smelters, which is rich in zinc, is transferred in thirteen tonne capacity ladles from the blast furnace to the slag fuming furnace. The cycle time is about three hours. The Study Group was asked to examine whether heat could be conserved by some insulation strategy, without at any stage overheating the steel of the ladle

Systems validation: application to statistical programs

BACKGROUND: In 2003, the United States Food and Drug Administration (FDA) released a guidance document on the scope of "Part 11" enforcement. In this guidance document, the FDA indicates an expectation of a risk-based approach to determining which systems should undergo validation. Since statistical programs manage and manipulate raw data, their implementation should be critically reviewed to determine whether or not they should undergo validation. However, the concepts of validation are not often discussed in biostatistics curriculum. DISCUSSION: This paper summarizes a "Plan, Do, Say" approach to validation that can be incorporated into statistical training so that biostatisticians can understand and implement validation principles in their research. SUMMARY: Validation is a process that requires dedicated attention. The process of validation can be easily understood in the context of the scientific method

Efficient numerical solution of the time fractional diffusion equation by mapping from its Brownian counterpart

The solution of a Caputo time fractional diffusion equation of order $0<\alpha<1$ is expressed in terms of the solution of a corresponding integer order diffusion equation. We demonstrate a linear time mapping between these solutions that allows for accelerated computation of the solution of the fractional order problem. In the context of an $N$-point finite difference time discretisation, the mapping allows for an improvement in time computational complexity from $O\left(N^2\right)$ to $O\left(N^\alpha\right)$, given a precomputation of $O\left(N^{1+\alpha}\ln N\right)$. The mapping is applied successfully to the least-squares fitting of a fractional advection diffusion model for the current in a time-of-flight experiment, resulting in a computational speed up in the range of one to three orders of magnitude for realistic problem sizes.Comment: 9 pages, 5 figures; added references for section

Generalised balance equations for charged particle transport via localised and delocalised states: Mobility, generalised Einstein relations and fractional transport

A generalised phase-space kinetic Boltzmann equation for highly non-equilibrium charged particle transport via localised and delocalised states is used to develop continuity, momentum and energy balance equations, accounting explicitly for scattering, trapping/detrapping and recombination loss processes. Analytic expressions detail the effect of these microscopic processes on the mobility and diffusivity. Generalised Einstein relations (GER) are developed that enable the anisotropic nature of diffusion to be determined in terms of the measured field-dependence of the mobility. Interesting phenomena such as negative differential conductivity and recombination heating/cooling are shown to arise from recombination loss processes and the localised and delocalised nature of transport. Fractional transport emerges naturally within this framework through the appropriate choice of divergent mean waiting time distributions for localised states, and fractional generalisations of the GER and mobility are presented. Signature impacts on time-of-flight current transients of recombination loss processes via both localised and delocalised states are presented.Comment: 21 pages, 4 figure

Well structured program equivalence is highly undecidable

We show that strict deterministic propositional dynamic logic with intersection is highly undecidable, solving a problem in the Stanford Encyclopedia of Philosophy. In fact we show something quite a bit stronger. We introduce the construction of program equivalence, which returns the value $\mathsf{T}$ precisely when two given programs are equivalent on halting computations. We show that virtually any variant of propositional dynamic logic has $\Pi_1^1$-hard validity problem if it can express even just the equivalence of well-structured programs with the empty program \texttt{skip}. We also show, in these cases, that the set of propositional statements valid over finite models is not recursively enumerable, so there is not even an axiomatisation for finitely valid propositions.Comment: 8 page

Monte Carlo aided design of the inner muon veto detectors for the Double Chooz experiment

The Double Chooz neutrino experiment aims to measure the last unknown neutrino mixing angle theta_13 using two identical detectors positioned at sites both near and far from the reactor cores of the Chooz nuclear power plant. To suppress correlated background induced by cosmic muons in the detectors, they are protected by veto detector systems. One of these systems is the inner muon veto. It is an active liquid scintillator based detector and instrumented with encapsulated photomultiplier tubes. In this paper we describe the Monte Carlo aided design process of the inner muon veto, that resulted in a detector configuration with 78 PMTs yielding an efficiency of 99.978 +- 0.004% for rejecting muon events and an efficiency of >98.98% for rejecting correlated events induced by muons. A veto detector of this design is currently used at the far detector site and will be built and incorporated as the muon identification system at the near site of the Double Chooz experiment

A Building Program Study

The purpose of this field study is to explore the need for a building program, to give recommendations for the best building site and why, and to check the feelings of the community on the passing of a referendum in Community Unit #3, Palestine, Illinois. This study included an evaluation of both the elementary and the high school buildings. This included the condition and availability of classroom space and special education space. The best possible site for a building program and reasons for the choice site were considered. The community of Palestine in the past has passed referendums for building projects, if the school has been capable of showing a real need for the building. It is the belief of this author that a referendum could pass, but it will take much research and communication between the school personnel and the community. The board of education and administration must be definite on what they want and be convinced that it is the best building program possible, before they try to persuade the citizens of the community to support the program. The reason for the consideration of a building program is a result of all the mandated programs and the emergence of girls athletics. The Palestine Community Unit Schools are located in the village of Palestine, Illinois, a town situated in the south eastern area of Crawford County. The Palestine Community Unit District #3 is a consolidated unit school district with the assessed valuation of $10,599,455 and the bonding ability of$1,486,764. The town of Palestine has a population of about 1,650 people. The Unit #3 District has a population of about 612 students of which 190 are presently enrolled in grades 9 through 12. Many parents live in the Palestine area and commute to Robinson which is 7 miles west of Palestine. The rural areas have a diversified type of agriculture, and business in the village is geared largely as supportive of agriculture enterprise. Palestine school district is considered 100% rural. The district has no private or parochial schools. The community is composed primarily of middle class citizens--a stable community of citizens who take pride in their homes, schools, and businesses. A large portion of this population is native to the Palestine area. However, current trends seem to indicate increased movement from the metropolitan areas. Most of the residents are commuter oriented-working in nearby towns. The working population seems to be primarily skilled and semi-skilled laborers. The main education level of the people of the Palestine Community has risen sharply within the last five years. This increase in education level is due in part, to the courses offered at Lincoln Trail Junior College and the courses offered at Palestine through the continuing education program. The high school student enrollment has been stable over the last ten years and by all indications it will remain stable for at least the next five years. Realizing that quality education can not exist without good facilities, high morale on the part of the faculty, and contentment, pride, and a learning attitude on the part of the students, this writer feels that the citizens of this community would support a building program, if they could be assured that it would solve the majority of the problems that the school district now has

Successful retrieval of competing spatial environments in humans involves hippocampal pattern separation mechanisms.

The rodent hippocampus represents different spatial environments distinctly via changes in the pattern of "place cell" firing. It remains unclear, though, how spatial remapping in rodents relates more generally to human memory. Here participants retrieved four virtual reality environments with repeating or novel landmarks and configurations during high-resolution functional magnetic resonance imaging (fMRI). Both neural decoding performance and neural pattern similarity measures revealed environment-specific hippocampal neural codes. Conversely, an interfering spatial environment did not elicit neural codes specific to that environment, with neural activity patterns instead resembling those of competing environments, an effect linked to lower retrieval performance. We find that orthogonalized neural patterns accompany successful disambiguation of spatial environments while erroneous reinstatement of competing patterns characterized interference errors. These results provide the first evidence for environment-specific neural codes in the human hippocampus, suggesting that pattern separation/completion mechanisms play an important role in how we successfully retrieve memories

Extending the aridity record of the Southwest Kalahari: current problems and future perspectives

An extensive luminescence-based chronological framework has allowed the reconstruction of expansions and contractions of the Kalahari Desert over the last 50 ka. However, this chronology is largely based on near-surface pits and sediment exposures. These are the points on the landscape most prone to reactivation and resetting of the luminescence dating ‘clock’. This is proving to be a limiting feature for extending palaeoenvironmental reconstructions further back in time. One way to obviate this is to sample desert marginal areas that only become active during significant arid phases. An alternative is to find and sample deep stratigraphic exposures. The Mamatwan manganese mine at Hotazel in the SW Kalahari meets both these criteria. Luminescence dating of this site shows the upper sedimentary unit to span at least the last 60 ka with tentative age estimates from underlying cemented aeolian units dating back to the last interglacial and beyond. Results from Mamatwan are comparable to new and previously published data from linear dunes in the SW Kalahari but extend back much further. Analysis of the entire data set of luminescence ages for the SW Kalahari brings out important inferences that suggest that different aeolian forms (1) have been active over different time scales in the past, (2) have different sensitivities to environmental changes and (3) have different time scales over which they record and preserve the palaeoenvironmental record. This implies that future optically stimulated luminescence work and palaeoenvironmental reconstructions must consider both site location and its relationship to desert margins and sediment depositional styles, so that the resolution and duration of the aridity record can be optimally understood