Rapid metal design

Computational material design tools have advanced so that custom materials for specific applications can be designed and manufactured. In the case of metals, my team designs aluminum, iron, nickel, and copper (more to come) alloys using Thermo-Calc with Bayesian optimization. We design microstructures to deliver properties such as strength, conductivity, and corrosion resistance. Custom tailored materials are now practical solutions to engineering challenges, and materials engineers work on multi-disciplinary teams to deliver integrated, enhanced product designs.https://digitalcommons.mtu.edu/techtalks/1003/thumbnail.jp

Three-dimensional Binary Superlattices of Oppositely-charged Colloids

We report the equilibrium self-assembly of binary crystals of oppositely-charged colloidal microspheres at high density. By varying the magnitude of the charge on near equal-sized spheres we show that the structure of the binary crystal may be switched between face-centered cubic, cesium chloride and sodium chloride. We interpret these transformations in terms of a competition between entropic and Coulombic forces

Effect of Zr additions on thermal stability of Al-Cu precipitates in as-cast and cold worked samples

While Zr is frequently added to Al alloys to control grain size with the formation of large (\u3e1 μm) primary precipitates, little research has been conducted on the effect of nanoscale Al3Zr precipitates on Al alloys. By comparing the precipitation and corresponding strength evolution between Al-Cu-Zr alloys with different Zr concentrations, the effects of Zr on Al-Cu precipitation with and without primary Al3Zr precipitates can be observed. In the absence of these large precipitates, all Al3Zr phases can be formed, through high temperature aging treatments, as a dispersion of nanoprecipaites inside the Al grains. In this study, Al-Cu-Zr ternary alloys were produced and heat treated to determine whether an increase in the coarsening resistance of Al-Cu precipitate phases would be observed with a distribution of the more thermally stable Al3Zr nanoprecipitates. Generally, properly aged Al-Cu alloys will coarsen when encountering elevated temperatures higher than ~473 K (~200 °C). Diluted Al-Zr alloys (\u3c0.07 at % Zr) resist coarsening behavior until the significantly higher temperatures of ~673 K (~400 °C), but are comparatively limited in strength because of a limited solubility of Zr in the Al matrix. Hardness testing and transmission electron microscope (TEM) results are discussed, in which it is found that even very small additions of Zr, when properly accounted for during heat treating, produce a finer microstructure and higher strength than in similar Al-Cu binary alloys. No significant change in the thermal stability of strengthening was observed, indicating that the finer precipitate microstructure is resultant from a higher nucleation density, as opposed to a decrease in coarsening behavior

Cotton Price Policy and New Cereal Technology in the Malian Cotton Zone

During the last decade, cotton production and area have been declining as a result of depleting soil nutrients and low cotton prices in the cotton zone of Mali. This paper shows that the Malian government’s 2011 policy to increase the farm gate cotton price as a response to world cotton price increase enhances farm income but has less impact on cotton than on maize production. A complementary policy of introducing new sorghum technologies would have an equal impact on farmers’ incomes in the cotton zone of Mali.Cotton prices, improved sorghum technology, discrete stochastic programming, Mali, Agricultural and Food Policy, Farm Management, International Development, Production Economics, Risk and Uncertainty,

Labor Law and Workmen\u27s Compensation -- 1956 Tennessee Survey

Labor Law Inducing Breach of Contract: Howard v. Haven\u27 was the only case during the survey period which presented a legal problem relating to the activities of a labor organization. In this case an electrical contractor sought an injunction and damages because of the acts of a local labor union, its business agent, and other named defendants in preventing the plaintiff from carrying out a hospital construction contract. On the trial of the case the determinative issue became whether or not the defendants brought about a breach of the contract which the complainant claimed to have had with the general contractor on the project in question. In response to specific questions the jury found that the defendant local labor union did unlawfully procure a breach of contract which complainant had with the general contractor, but it answered the same question in the negative with respect to the local union\u27s business agent and another named defendant. Damages were assessed by the jury at $7,330, which were trebled in the judgment entered by the chancellor pursuant to Williams code section 7811. ===================================== Workmen\u27s Compensation Employees\u27 claims for workmen\u27s compensation were involved in twenty-three of the cases before the Supreme Court during the survey year, and three cases presented questions of first impression. Although the Tennessee Workmen\u27s Compensation Law was enacted over thirty-seven years ago, controversy still rages with apparently undiminished vigor over its proper interpretation and application

Labor Law and Workmen\u27s Compensation -- 1957 Tennessee Survey

The decisions of Tennessee appellate courts during the survey period have dealt extensively with the major area of controversy in current labor relations law--federal preemption.\u27 The number of Tennessee decisions handed down which relate to injunctions restraining directly or indirectly the activities of labor organizations exceeds that in any recent comparable period. Clarification of the law applicable in the courts of the state to such activities, however, has not been achieved through these decisions. Two were reversed subsequently without opinion by the Supreme Court of the United States, and these two reversals, in turn, present serious questions as to the ultimate effect of the holdings in three additional Tennessee cases of the survey period. The problem is further complicated when consideration is given to the United States Supreme Court\u27s affirmance of a Wisconsin injunction three weeks after the reversal of the Tennessee decisions. One of the Tennessee decisions involved picketing to achieve a purpose deemed contrary to the state\u27s right-to-work statute, as did the Wisconsin case

Labor Law and Workmen\u27s Compensation -- 1954 Tennessee Survey

Labor Law is best defined, perhaps, as that body of law which is directed toward, and peculiar to, the various incidents of the employer-employee relationship, whether viewed individually or collectively.\u27 In this sense it includes all laws, such as those on workmen\u27s compensation, wages and hours and unemployment insurance, setting forth the rights and limitations of the individual employee as against the employer (directly or indirectly), as well as those concerned with union organizational activity and collective bargaining

Terrestrial Measurements of Diffusivities in Refractory Melts by Pulsed Melting of Thin Films

Laterally homogeneous pulsed melting of thin films is being investigated as a way to eliminate convection and thereby determine diffusivities in refractory mels under terrestrial conditions, providing comparison data for microgravity measurements. The silicon liquid self-diffusivity was determined by pulsed laser melting for 30Si+ experimental concentration spatial profile given the initial concentration profile and the temporal melt-depth profile. The silicon liquid self-diffusivity at the melting point (4.0 plus or minus 0.5) X 10-4cm2/s. Calculations of Buoyancy and Marangoni convection indicate that convective contamination is unlikely.Engineering and Applied Science

Free and open-source control software for 3-D motion and processing

RepRap 3-D printers and their derivatives using conventional firmware are limited by: 1) requiring technical knowledge, 2) poor resilience with unreliable hardware, and 3) poor integration in complicated systems. In this paper, a new control system called Franklin, for CNC machines in general and 3-D printers specifically, is presented that enables web-based three dimensional control of additive, subtractive and analytical tools from any Internet connected device. Franklin can be set up and controlled entirely from a web interface; it uses a custom protocol which allows it to continue printing when the connection is temporarily lost, and allows communication with scripts

Effect of urinary pH and diatrizoate on Bence Jones protein nephrotoxicity in the rat

Effect of urinary pH and diatrizoate on Bence Jones protein nephrotoxicity in the rat. Both low urinary pH and radiocontrast agents may intensify myeloma nephrotoxicity. To study the effects of these factors, we determined inulin clearances (CIn) before and after infusions of human Bence Jones protein (BJP) in male Sprague-Dawley rats in a dose previously shown to be nephrotoxic. Rats that drank 0.15 M NaHCO3 for 48 hr before study had no change in CIn (+ 3 ± 20%) after BJP unlike those that drank 0.15 M NH4Cl (- 33 ± 14%, P < 0.05); urinary pH differed (7.6 ± 0.1 vs. 6.2 ± 0.1, P < 0.05), but urinary flow rates did not. The acidifying regimen was used in all subsequent groups. Infusion of diatrizoate (DTZ) after BJP produced a further decrease in CIn (- 85 ± 8%, P < 0.05). In contrast, infusion of albumin, which raised plasma protein concentration to that seen in BJP-infused rats, did not change CIn (+ 39 ± 17%). Infusion of beta-lactoglobulin also led to a greater decrease in CIn after DTZ (- 35 ± 9 vs. - 67 ± 8%, P < 0.05), but myoglobin did not (- 58 ± 7 vs. - 54 ± 12%). Urinary pH and flow rate did not differ between any DTZ-infused group and its appropriate control. These data suggest that aciduria independent of urinary flow rate increases the nephrotoxicity of BJP. In this setting, DTZ further intensifies the nephrotoxicity of BJP as well as some but not all filterable proteins.Effet du pH urinaire et du diatrizoate sur la néphrotoxicité de la protéine de Bence Jones chez le rat. Un pH urinaire bas et les produits de contraste peuvent accroître la néphrotoxité du myélome. Pour étudier les effets de ces facteurs, nous avons déterminé les clearances de l'inuline (CIn) avant et après perfusion de protéine de Bence Jones humaine (BJP) chez des rats mâles Sprague-Dawley à dose préalablement montrée néphrotoxique. Les rats qui buvaient 0,15 M NaHCO3 pendant 48 hr avant l'étude n'avaient pas de modification de CIn (+ 3 ± 20%) après BJP à la différence de ceux qui buvaient 0,15 M NH4Cl (- 33 ± 14%, P < 0,05); les pH urinaires différaient (7,6 ± 0,1 contre 6,2 ± 0,1, P < 0,05), mais non les débits urinaires. Le régime acidifiant a été utilisé chez tous les groupes ultérieurs. La perfusion de diatrizoate (DTZ) après BJP a entraîné une diminution supplémentaire de CIn (- 85 ± 8%, P < 0,05). A l'opposé une perfusion d'albumine, qui augmentait la protidémie à la valeur observée chez les rats perfusés avec BJP ne modifiait pas CIn (+ 39 ± 17%). Une perfusion de béta-lactoglobuline a également entraîné une plus forte baisse de CIn après DTZ (- 35 ± 9 contre - 67 ± 8%, P < 0,05), mais non de la myoglobine (- 58 ± 7 contre - 54 ± 12%). Le pH et le débit urinaires ne différaient pas entre aucun des groupes perfusés par le DTZ et leur contrôle approprié. Ces données suggèrent que l'acidurie, indépendamment du débit urinaire, augmente la néphrotoxicité de la BJP. Dans ce schéma, DTZ accentue encore la néphrotoxicité de la BJP, de même que certaines, mais non toutes les protéines filtrables