Fracture-tough, corrosion-resistant bearing steels

The fundamental principles allowing design of stainless bearing steels with enhanced toughness and stress corrosion resistance has involved both investigation of basic phenomena in model alloys and evaluation of a prototype bearing steel based on a conceptual design exercise. Progress in model studies has included a scanning Auger microprobe (SAM) study of the kinetics of interfacial segregation of embrittling impurities which compete with the kinetics of alloy carbide precipitation in secondary hardening steels. These results can define minimum allowable carbide precipitation rates and/or maximum allowable free impurity contents in these ultrahigh strength steels. Characterization of the prototype bearing steel designed to combine precipitated austenite transformation toughening with secondary hardening shows good agreement between predicted and observed solution treatment response including the nature of the high temperature carbides. An approximate equilibrium constraint applied in the preliminary design calculations to maintain a high martensitic temperature proved inadequate, and the solution treated alloy remained fully austenitic down to liquid nitrogen temperature rather than transforming above 200 C. The alloy can be martensitically transformed by cryogenic deformation, and material so processed will be studied further to test predicted carbide and austenite precipitation behavior. A mechanistically-based martensitic kinetic model was developed and parameters are being evaluated from available kinetic data to allow precise control of martensitic temperatures of high alloy steels in future designs. Preliminary calculations incorporating the prototype stability results suggest that the transformation-toughened secondary-hardening martensitic-stainless design concept is still viable, but may require lowering Cr content to 9 wt. pct. and adding 0.5 to 1.0 wt. pct. Al. An alternative design approach based on strain-induced martensitic transformation during cryogenic forming, thus removing the high martensitic constraint, may permit alloy compositions offering higher fracture roughness

Fracture-tough, high hardness stainless steel and method of making same

A cryogenically-formed and tempered stainless steel is provided having improved fracture toughness and corrosion resistance at a given hardness level, such as, for example, of at least about Rc 60 for bearing applications. The steel consists essentially of, in weight %, about 21 to about 24% Co, about 11 to about 13% Cr, about 7 to about 9% Ni, about 0.1 to about 0.5% Mo, about 0.2 to about 0.3% V, about 0.28 to about 0.32% C, and the balance iron. The steel includes a cryogenically-formed martensitic microstructure tempered to include about 5 to about 10 volume % post-deformation retained austenite dispersed therein and M.sub.2 C-type carbides, where M is Cr, Mo, V, and/or Fe, dispersed in the microstructure

Civic Attitude and Activity of Loma Linda University Dental Graduates

Introduction: Dentistry is regarded as a profession and granted certain privileges, such as self-regulation. Associated with this status are stated and implied responsibilities which are widely debated. In recent years, dental professionalism seems to be on the decline. Evidence cited includes access-to-care issues and decreased public trust in dentists. In response, academia and professional organizations have developed curricula and statements intended to bolster professionalism. Meanwhile little is known about practicing dentists’ attitudes or participation in health-related civic matters. Objectives: This study seeks to examine the importance Loma Linda University (LLU) dental graduates place on public roles, their reported participation in public activities and the factors related to their responses. Methods: Four hundred and fifty-six LLU dental graduates were surveyed. Civic-mindedness was ascertained from respondents’ reported attitudes regarding community participation, political involvement and collective advocacy. Civic activity was determined from reported civic participation during the last three years. Additional responses were gathered on a number of health-related issues to assess the respondents’ level of social concern beyond the immediate dental care needs of their patients. Findings from this study were compared with those of a similar study of physicians from the US.1 Results: Overall, three quarters of LLU respondents were considered civic-minded and 91% participated in civic activities. Attitudes regarding civic obligations were very similar to the US physician group. 1 The LLU dental graduates, however, reported a higher level of civic action than did the US physicians1 (91% vs. 65%). Regression analysis for civic-mindedness determined female gender and the specialties of pediatric dentistry and orthodontics were salient factors. Regression analysis for civic activity determined civic-mindedness, pediatric dentistry, and professional age greater than 20 years were related factors. The majority of LLU respondents, unlike US physicians, 1 deemed broader concerns not obviously tied to the health of their patients as important. The implications of these results as well as directions for future research were discussed

Three Year Assessment of Nearshore Crude Oil Contamination in the Gulf of Mexico Using Gulf Menhaden (Brevoortia Patronus) as an Indicator Species: Menhaden Watch

Approximately 4.9 million barrels of crude oil along with natural gas were released into the Gulf of Mexico (GoM) from April to July 2010 (Deepwater Horizon, DWH, spill). Impacts of this magnitude seldom occur in the GoM (Ixtoc I was the last spill close to this magnitude occurring in 1979), and one cannot predict when they will happen. Major constituents of concern found in crude oil are Polycyclic Aromatic Hydrocarbons (PAHs), which often have low volatility that allows for prolonged existence in the environment. PAHs are compounds of concern according to the United States Environmental Protection Agency (USEPA), with one characteristic being that they have the potential to accumulate within adipose tissue. Several PAHs are listed as mutagenic and carcinogenic, making their presence in commercial fishery populations of major environmental concern. Gulf menhaden fishery was chosen for use as an indicator for impact of crude oil exposure in the years following the spill event. Total whole body PAH concentrations along with both benzo[a]pyrene, toxic and mutagenic equivalents (BaP-TEQ and BaP-MEQ respectively), were used to determine overall impact on the species. Proposed standard weight equations and length categories for Gulf menhaden were developed to assess morphological changes in the species. Lipid content was also used as a metric for determining overall health of the Gulf menhaden. Results are outlined in each chapter abstract

The Hydroxylation Equilibrium Constant for 2,4 Dichlorobenzaldehyde at Various Temperatures

The primary objective of this work was to examine the temperature dependence of dissociation constants of hydroxylated substituted benzldehydes. The equilibrium of 2,3 dichlorobenzaldehyde in aqueos sodium hydroxide solutions has been studied at 35 degrees celsius with varying hydroxide ion concenctrations

PAH Concentrations Found within Gulf Menhaden (Brevoortia patronus) Populations Located off of the South/Southeast Coast of Louisiana

In April 2010, large quantities of crude oil were released into the Gulf of Mexico (GoM) raising questions about the possible contamination of marine organisms with constituents of concern known as Polycyclic Aromatic Hydrocarbons (PAHs). In order to determine the impact of the Deepwater Horizon (DWH) crude oil spill, Gulf menhaden (Brevoortia patronus) were harvested from two coastal regions of Louisiana. Tissue analysis to determine total PAH concentration was conducted using an adapted matrix solid phase dispersion (MSPD) method; a Soxhlet extraction process was used to determine fish oil to mass ratios for “small” (fork length \u3c 16 cm) and “large” (fork length \u3e 16 cm) menhaden. Menhaden oil and meal, harvested prior to the DWH spill, was used to create menhaden facsimiles for baseline total PAH concentrations. Gulf menhaden were harvested off of the coast of Louisiana from July 2011 through October 2011. Sampling occurred at sites around Vermilion Bay (VB) as well as Grand Isle (GI) and the menhaden were analyzed by region as well as size to determine if the concentrations of PAHs varied based on these factors. PAH concentrations were quantified along with total Benzo[a]pyrene mutagenic (B[a]P-MEQ) and Benzo[a]pyrene toxic equivalencies (B[a]P-TEQ) and all analysis was completed using Gas Chromatography/Mass Spectroscopy (GC/MS). Results were reported in ng of total PAH/g of dry weight tissue and the detection limits of the GC/MS method were between 0.4 ng/g dry weight and 4.4 ng/g dry weight. In conclusion, the two Louisiana coastal regions were not statistically different and therefore cannot be used to identify the impact of the DWH spill in a one-year sampling event. However, PAH concentrations were statistically different based on month with a significant interaction based on size. Mean concentrations for “small” and “large” menhaden were not statistically different; the B[a]p-TEQs were highly significant suggesting the larger menhaden were exposed to more carcinogenic PAHs throughout their life due to variations in feeding patterns. Continuing the study for a second year will provide further elucidation on species life cycle exposure to PAHs and possible impacts to fisheries

A potential role for Dkk-1 in the pathogenesis of osteosarcoma predicts novel diagnostic and treatment strategies.

Canonical Wnt signaling is an osteo-inductive signal that promotes bone repair through acceleration of osteogenic differentiation by progenitors. Dkk-1 is a secreted inhibitor of canonical Wnt signaling and thus inhibits osteogenesis. To examine a potential osteo-inhibitory role of Dkk-1 in osteosarcoma (OS), we measured serum Dkk-1 in pediatric patients with OS (median age, 13.4 years) and found it to be significantly elevated. We also found that Dkk-1 was maximally expressed by the OS cells at the tumor periphery and _in vitro_ Dkk-1 and RANKL are co-expressed by rapidly proliferating OS cells. Both Dkk-1 and conditioned media from OS cells reduces osteogenesis by human mesenchymal cells and by immuno-depletion of Dkk-1, or by adding a GSK3[beta] inhibitor, the effects of Dkk-1 were attenuated. In mice, we found that the expression of Dkk-1 from implanted tumors was similar to the human tumor biopsies in that human Dkk-1 was present in the serum of recipient animals. These data demonstrate that systemic levels of Dkk-1 are elevated in osteosarcoma. Furthermore, the expression of Dkk-1 by the OS cells at the periphery of the tumor probably contributes to its expansion by inhibiting repair of the surrounding bone. These data demonstrate that Dkk-1 may serve as a prognostic or diagnostic marker for evaluation of OS and furthermore, immuno-depletion of Dkk-1 or administration of GSK3[beta] inhibitors could represent an adjunct therapy for this disease

Debunking Intellectual Property Myths: Cross Cultural Experiments on Perceptions of Property

For decades, the prevailing view in the United States and many Western countries has been that China does not appropriately respect intellectual property rights. These beliefs lie at the heart of President Donald Trump’s current trade war with China. Despite substantial geopolitical debate over differences between American an d Chinese attitudes towards intellectual property rights, and despite the critical effects that such attitudes have on international economic markets and the function of intellectual property systems, empirical evidence of these attitudes is largely lacking. This Article presents original experimental survey research that explores cross cross-cultural differences between American and Chinese attitudes towards intellectual property rights, personal property rights, and real property rights. The results of the studies are somewhat counterintuitive. First, Chinese participants are found to have more consistent preferences towards different types of property rights than Americans. In a series of vignettes designed to test attitudes towards patented subject matter, copyrighted subject matter, tangible personal property, and real property, Chinese responses were more consistent and less context driven. Second, Americans do identify a preference for stronger intellectual property rights than Chinese, but only where infringement is committed by a private party for private benefit. Where infringement is conducted for public benefit, whether by a private or a governmental entity, Chinese and Americans tend to have the same attitudes towards intellectual property rights. Third , Americans display a lower regard for intellectual property rights than for tangible property rights in most contexts, a differential that is not echoed in Chinese responses. The distinctions that Americans draw based on the use to which property is put, and between intellectual property and tangible property, is not consistent with United States law. Our experiments reveal that the ongoing debates over Chinese attitudes towards intellectual property rights miss the mark in certain regards. Chinese and American preferences for property rights are more similar than most have assumed, and the manners in which they differ are inconsistent with most proffered theories. These results provide important lessons for the future of international intellectual property rights relations, discourse, and enforcement

Intellectual Property Law’s Plagiarism Fallacy

Intellectual property law is caught in a widespread debate over whether it should serve incentive or natural rights objectives, and what the best means for achieving those ends are. This article reports a series of experiments revealing that these debates are actually orthogonal to how most users and many creators understand intellectual property law. The most common perception of intellectual property among the American public is that intellectual property law is designed to prevent plagiarism. The plagiarism fallacy in intellectual property law is not an innocuous misperception. This fallacy likely helps explain pervasive illegal infringing activity on the Internet, common dismissal of copyright warnings, and other previously puzzling behavior. The received wisdom has been that the public is ethically dismissive or indifferent towards intellectual property rights. This research reveals instead that experts have failed to comprehend what the public’s conception of intellectual property law actually is. The studies reported here uncover several additional intellectual property law findings, including that (1) the majority of the American public views intellectual property rights as too broad and too strong, (2) knowledge of intellectual property law does not affect opinions about what the law should be, and (3) there are significant demographic and cultural divides concerning attitudes towards intellectual property rights. The findings as a whole raise central questions concerning the public legitimacy of intellectual property law and, consequently, its ability to function as intended