Multi-Layer Aluminum Alloy Products and Methods of Manufacture

Described herein are multilayer aluminum alloy products containing four or more different layers and methods for making multilayer aluminum alloy products. The disclosed methods include additive manufacturing processes in which different aluminum alloys are deposited on underlying layers to make a multilayer aluminum alloy product

Centerline Depletion in Direct-Chill Cast Aluminum Alloys: The Avalanche Effect and Its Consequence for Turbulent Jet Casting

Avalanche dynamics of sedimenting grains in direct-chill casting of aluminum ingots is investigated as a primary driving force for centerline segregation. An analytical model predicting the importance of avalanche events as a function of casting parameters is proposed and validated with prior art results. New experimental results investigating the transient and steady-state centerline segregation of DC casting with a turbulent jet are reported

Metal Products Exhibiting Improved Mechanical Properties and Methods of Making the Same

The present disclosure relates to metal stock and methods for producing metal stock, such as coils of metal strip, and more specifically to continuously cast recrystallized alloys containing dispersoids, as well as the processes for making such alloys

Some thoughts on pseudoprimes

We consider several problems about pseudoprimes. First, we look at the issue of their distribution in residue classes. There is a literature on this topic in the case that the residue class is coprime to the modulus. Here we provide some robust statistics in both these cases and the general case. In particular we tabulate all even pseudoprimes to $10^{16}$. Second, we prove a recent conjecture of Ordowski: the set of integers $n$ which are a pseudoprime to some base which is a proper divisor of $n$ has an asymptotic density

Reliably Making Monolithic Ingots of Difficult to Cast Aluminum Alloys Using Direct Chill Casting

Described are monolithic aluminum alloy ingots and methods of making monolithic aluminum alloy ingots, such as monolithic aluminum alloy ingots comprising brittle aluminum alloys formed by direct chill co-casting the brittle aluminum alloy as a core with a clad layer of another more ductile aluminum alloy as a composite ingot followed by scalping the resultant composite ingot to remove the clad layer

A METHOD FOR REDUCING ALLIGATORING DURING THE HOT ROLING PROCESS OF ALUMINUM INGOTS

The embodiments described herein rely on the ability to cast a distinct alloy into the head of an ingot, and to secure a reliable metallurgical bond between the parent alloy of the ingot and the softer alloy. The timing of the addition of the distinct alloy and the composition of the distinct alloy are important for success, and in turn reduction in the alligatoring defect

Strengthening the Baillie-PSW primality test

The Baillie-PSW primality test combines Fermat and Lucas probable prime tests. It reports that a number is either composite or probably prime. No odd composite integer has been reported to pass this combination of primality tests if the parameters are chosen in an appropriate way. Here, we describe a significant strengthening of this test that comes at almost no additional computational cost. This is achieved by including in the test what we call Lucas-V pseudoprimes, of which there are only five less than $10^{15}$.Comment: 25 page

The insufficiency of circulating miRNA and DNA as diagnostic tools or as biomarkers of treatment efficacy for Onchocerca volvulu

Skin snip evaluation for onchocerciasis has insufficient sensitivity when skin microfilarial (mf) densities are low, such as following ivermectin treatment. Mf density is suitable for assessing microfilaricidal efficacy but only serves as an indirect indicator of macrofilaricidal activity. We assessed circulating nucleic acids from Onchocerca volvulus as an alternative to skin snips. We screened a plasma sample set of infected individuals followed up at four, 12 and 21 months after microfilaricidal (ivermectin, n = four), macrofilaricidal (doxycycline, n = nine), or combination treatment (n = five). Two parasite-derived miRNAs, cel-miR-71-5p and bma-lin-4, and O-150 repeat DNA were assessed. Highly abundant DNA repeat families identified in the O. volvulus genome were also evaluated. miRNAs were detected in two of 72 plasma samples (2.8%) and two of 47 samples (4.3%) with microfilaridermia using RT-qPCR. O-150 DNA was detected in eight (44.4%) baseline samples by qPCR and the number of positives declined post-treatment. One doxycycline-treated individual remained O-150 positive. However, only 11 (23.4%) samples with microfilaridermia were qPCR-positive. Analysis by qPCR showed novel DNA repeat families were comparatively less abundant than the O-150 repeat. Circulating parasite-derived nucleic acids are therefore insufficient as diagnostic tools or as biomarkers of treatment efficacy for O. volvulus

Continuous Casting of Multi-Alloy Metal Products and Related Methods

Described are multi-alloy metal products formed by a continuous casting system, as well as methods of continuously casting multi-alloy metal products. The disclosed multi-alloy metal product includes a plurality of layers of metallurgically bonded together metal alloys. The layers can be distributed along the thickness of the metal product or along the width of the metal product. The disclosed continuous casting system includes a plurality of injectors configured to simultaneously inject a plurality of metal alloys into a casting cavity to form the multi-alloy metal product