The Effect of 45° Rolling Process on the Mechanical Properties of P/M Rhenium

A novel processing technique which utilizes the 45° rolling mode is introduced. An optimum processing method of light rolling (10-12% reduction in thickness) along the 45° direction, followed by intermittent annealing (1650°C / 30 min. in H₂ atmosphere) was carried out. The partial reduction and intermittent annealing were repeated until an 82.9% reduction was achieved with a tensile strength of 2388 MPa (346.6 Ksi) and 3.3% elongation. Additional experiments were performed to test the feasibility of increasing the percentage of reduction in thickness in cold rolling from the conventional 10-15% to 20-55% along the 45° direction. Although extensive microcracking occurred, intermediate strengths were achieved and ductility was retained. This processing technique has the potential of producing ultra high strength, very thin sheets, which are vital for space nuclear power applications and missile guidance systems.     

Patterns of publication by the staff of an international fisheries research center

The scientific productivity, measured as number of publication credits per year, of 105 BS, MS and PhD degree holders at the authors' institution — a nonprofit international fisheries research organization based in Manila—was studied. All authored and edited items produced by these staff, from 1978 to 1993, presently published or in press were considered, and weights assigned depending on document type, number of pages, and rank of the name in cases of multiple authorship or editorship. The staff's output of conference papers and technical reports outweighed contributions to the primary (journal) literature. Predictors of productivity were position/salary, education, and age. However, a large unexplained variance remained, suggesting that individual factors largely determine productivity.ICLARM Contribution No. 1046.     

CHF enhancement by vessel coating for external reactor vessel cooling

In-vessel retention (IVR) is a key severe accident management (SAM) strategy that has been adopted by some operating nuclear power plants and proposed for some advanced light water reactors (ALWRs). One viable means for IVR is the method of external reactor vessel cooling (ERVC) by flooding the reactor cavity during a severe accident. As part of a joint Korean–United States International Nuclear Energy Research Initiative (K-INERI), an experimental study has been conducted to investigate the viability of using an appropriate vessel coating to enhance the critical heat flux (CHF) limits during ERVC. Toward this end, transient quenching and steady-state boiling experiments were performed in the subscale boundary layer boiling (SBLB) facility at the Pennsylvania State University using test vessels with micro-porous aluminum coatings. Local boiling curves and CHF limits were obtained in these experiments. When compared to the corresponding data without coatings, substantial enhancement in the local CHF limits for the case with surface coatings was observed. Results of the steady-state boiling experiments showed that micro-porous aluminum coatings were very durable. Even after many cycles of steady-state boiling, the vessel coatings remained rather intact, with no apparent changes in color or structure. Moreover, the heat transfer performance of the coatings was found to be highly desirable with an appreciable CHF enhancement in all locations on the vessel outer surface but with very little effect of aging.     

How to evaluate suspected immunodeficiency

The periacetabular osteotomy is a strategy for the treatment of residual hip dysplasia in young adults with the aim of preventing secondary coxarthrosis. This polygonal, juxta-articular osteotomy respects the vascular blood supply to the acetabular fragment and thus facilitates an extensive acetabular reorientation with improvement of the insufficient coverage of the femoral head, including medial displacement of the fragment. All osteotomies are performed by one approach, the modified Smith-Petersen, which allows an anterior capsulotomy. Inspection of the joint not only provides information on acetabular rim pathologies, but also facilitates the control of impingement-free range of motion after the correction. The posterior column remains partially intact, allowing minimal internal fixation of the acetabular fragment and early mobilization similar to that after an intertrochanteric osteotomy. The dimensions of the true pelvis are unchanged, providing the capacity to have an unimpeded delivery in women. This paper describes the preoperative evaluation, current indications, surgical technique, postoperative care, and the results of this osteotomy.     

Ic degradation behaviors of Bi-2223 superconducting tapes under axial fatigue loading

For the endurance evaluation of High Temperature Superconductors (HTS), the mechanical and transport properties of multifilamentary Bi₂Sr₂Ca₂Cu₃O_10+x (Bi-2223) superconducting tapes with different reinforcements subjected to high-cycle axial fatigue loading were investigated at 77 K in the self-field. The mechanical fatigue limits based on the relations between the applied stress amplitude and the numbers of cyclic steps to reach failure (S-N_f curves) were obtained. The transport properties were evaluated with the increase of repeated cycles, N, at different applied stress amplitudes which eventually leads to the electric fatigue limit. The influence of reinforcement on the mechanical and transport properties of Bi-2223 tapes were discussed. Fractographic observation was performed in order to understand the I_c degradation mechanism in fatigue tested Bi-2223 tapes.     

On the Selection of Durable Coatings for Cryogenic Engine Technology

Many benefits can be realized by incorporating hydrostatic bearings into liquid hydrogen turbopumps; however, suitable material coatings must be used to avoid excessive wear during multiple starts and stops. Chemical vapor deposited (CVD) diamond coatings were developed and tested at Phillips Laboratory for use as liquid hydrogen rocket turbopump bearing surfaces. A short list of coating materials other than diamond is suggested. Nine manufacturers out of fifty contacted are identified as capable of depositing durablecoatings on Inconel 718. A cost effective low temperature tribometer based on the hydrostatic bearing application should be designed and built prior to performing full scale tests.     

A multigigahertz clocking scheme for the Pentium(R) 4microprocessor

Core and I/O clock design for the Pentium(R) 4 microprocessor is described. Two phase-locked loops generate core and I/O clocks supporting concurrent multiple frequencies. A clock distribution network with skew optimization and jitter reduction is designed to achieve low clock inaccuracies for processors at frequencies ⩾2 GHz for the core and ⩾4 GHz for the rapid execution engine. A global medium clock frequency is distributed. Local clock drivers generate pulsed or regular (nonpulsed) clocks at fast, medium, and slow frequencies. A 3.2-GB/s system bus is achieved using a dedicated I/O phase-locked loop with glitch protection and detection. Silicon speed path tools and clock debug features are designed to enable a short debug cycle     

Genetically Modified (GM) Foods and Ethical Eating

The ability to manipulate and customize the genetic code of living organisms has brought forth the production of genetically modified organisms (GMOs) and consumption of genetically modified (GM) foods. The potential for GM foods to improve the efficiency of food production, increase customer satisfaction, and provide potential health benefits has contributed to the rapid incorporation of GM foods into the American diet. However, GM foods and GMOs are also a topic of ethical debate. The use of GM foods and GM technology is surrounded by ethical concerns and situational judgment, and should ideally adhere to the ethical standards placed upon food and nutrition professionals, such as: beneficence, nonmaleficence, justice and autonomy. The future of GM foods involves many aspects and trends, including enhanced nutritional value in foods, strict labeling laws, and potential beneficial economic conditions in developing nations. This paper briefly reviews the origin and background of GM foods, while delving thoroughly into 3 areas: (1) GMO labeling, (2) ethical concerns, and (3) health and industry applications. This paper also examines the relationship between the various applications of GM foods and their corresponding ethical issues. Ethical concerns were evaluated in the context of the code of ethics developed by the Academy of Nutrition and Dietetics (AND) that govern the work of food and nutrition professionals. Overall, there is a need to stay vigilant about the many ethical implications of producing and consuming GM foods and GMOs.