Case study of life safety standards for a large mined underground space facility in minneapolis, minnesota

Life safety concerns related to fires and explosions are critical design issues for large subsurface facilities. This paper reviews these issues and discusses them in terms of existing life safety codes. The authors apply principles of layout and physical design for life safety to the development of large mined space facilities in the City of Minneapolis. Also discusses is a case study of life safety standards for a large underground building under consideration at the University of Minnesota.     

Effect of milk replacer program on digestion of nutrients in dairy calves

There are concerns with feeding young dairy calves amounts of milk solids approaching 0.9 kg of dry matter (DM) or more because of slumps in average daily gain (ADG) at weaning and low starter intakes. Additionally, programs feeding more than 0.6 kg of DM have not been thoroughly tested for success at different weaning ages. Four milk replacer (MR) programs were compared in trial 1. Program A was 0.44 kg of DM of a 21% crude protein (CP), 21% fat MR powder fed daily for 42 d. Program B was 0.66 kg of DM of a 27% CP, 17% fat MR powder fed daily for 42 d. Program C was 0.66 kg of DM of a 27% CP, 17% fat MR powder daily fed for 28 d. Program D was up to 1.09 kg of DM of a 29% CP, 21% fat MR daily fed for 49 d. Digestibility estimates were made and blood was sampled for serum constituents on d 53 to 56, and performance was measured for 84 d. Three programs feeding a 27% CP, 17% fat MR powder were compared in trial 2 over 56 d. Calves on program A were fed 0.66 kg of DM powder daily and weaned at 28 d. Calves on program B were fed 0.66 kg of DM powder daily and weaned at 42 d. Calves on program C were fed up to 1.09 kg of DM powder daily and weaned at 42 d. Digestibility estimates were made and blood was sampled for serum constituents d 21 to 24, d 36 to 39, and d 53 to 56. In trial 1, calves fed program A had the least overall ADG. Calves fed program D had the greatest ADG from 0 to 56 d, the least ADG from d 56 to 84, the least digestibility estimates, and the least concentrations of serum amylase. At 84 d, there were no differences in body weights of calves fed programs B, C, and D. In trial 2, calves fed program A had the greatest starter intake and greatest concentrations of serum amylase. Calves fed program C had the least estimates of digestibility from d 53 to 56 and the least serum concentrations of amylase. Calves fed up to 1.09 kg/d of 27 to 29% MR powders and weaned at 42 or 49 d had lower starter intakes, concentrations of serum amylase, and digestion of starter postweaning compared with calves fed conventional 21% CP, 21% fat MR powders fed at 0.44 kg/d. Calves fed 0.66 kg/d of a 27% CP, 17% fat MR powder and weaned at 28 or 42 d of age had no reductions in intake or digestion compared with calves fed conventional MR and gained as much total body weight from 0 to 84 d as calves stepped up to 1.09 kg of MR.     

The self-importance of moral identity.

Recent theorizing in moral psychology extends rationalist models by calling attention to social and cultural influences (J. Haidt, 2001). Six studies using adolescents, university students, and adults measured the associations among the self-importance of moral identity, moral cognitions, and behavior. The psychometric properties of the measure were assessed through an examination of the underlying factor structure (Study 1) and convergent, nomological, and discriminant validity analyses (Studies 2 and 3). The predictive validity of the instrument was assessed by examinations of the relationships among the self-importance of moral identity, various psychological outcomes, and behavior (Studies 4, 5, and 6). The results are discussed in terms of models of moral behavior, social identity measurement, and the need to consider moral self-conceptions in explaining moral conduct. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Translational Planar Cable-Direct-Driven Robots

A planar cable-direct-driven robot (CDDR) architecture is introduced with only translational freedoms. The motivation behind this work is to improve the serious cable interference problem with existing CDDRs and to avoid configurations where negative cable tensions are required to exert general forces on the environment and during dynamic motions. These problems generally arise for rotational CDDR motions. Thus, we propose a class of purely translational CDDRs; of course, these are not general but may only perform tasks where no rotational motion or resistance of moments is required at the end-effector. This article includes kinematics and statics modeling, determination of the statics workspace (the space wherein all possible Cartesian forces may be exerted with only positive cable tensions), plus a dynamics model and simulated control for planar translational CDDRs. Examples are presented to demonstrate simulated control including feedback linearization of the 4-cable CDDR (with two degrees of actuation redundancy) performing a Cartesian task. We introduce an on-line dynamic minimum torque estimation algorithm to ensure all cable tensions remain positive for all motion; otherwise slack cables result from the CDDR dynamics and control is lost.     

Thermal and electrical properties of spark plasma sintered (Ti,Cr)B2 ceramics

Thermal and electrical properties were measured for TiB₂ ceramics containing varying CrB₂ contents up to 33 mol%. The room-temperature thermal diffusivity decreased with increasing Cr content from 0.330 ± 0.003 cm²/s for pure TiB₂ to 0.060 ± 0.003 cm²/s for (Ti_0.66Cr_0.33)B₂. The amount of anisotropy in the coefficients of thermal expansion increased with increasing Cr content and the c-axis had the greatest dependence on Cr addition, with an increase of more than 25% in the thermal expansion for 33 mol% CrB₂ compared to TiB₂, whereas the a-axis only increased by about 8%. The electrical conductivity was the lowest for (Ti_0.66Cr_0.33)B₂ at ∼8.5 × 10³ S/cm compared to ∼106.1 × 10³ S/cm for nominally pure TiB₂. Overall, the addition of CrB₂ as a sintering aid for TiB₂ was shown to have a significant effect on the thermal and electrical properties of TiB₂ for additions as small as 5 mol% CrB₂.     

Pressureless sintering of dual-phase,high-entropy boride–carbide ceramics

Dual-phase, high-entropy boride–carbide ceramics were densified by pressureless sintering. Relative densities up to approximately 96% were obtained for ceramics containing about 30 vol% high-entropy boride and 70 vol% high-entropy carbide. Isostatic pressing at 200 MPa resulted in higher relative densities of both the green bodies and final ceramics compared to uniaxial pressing. The highest relative density of 96.3% was achieved for a ceramic that was isostatically pressed at 200 MPa and sintered at 2300°C for 2 h. Grain sizes of the resulting ceramics were approximately 2 µm. This is the first report of pressureless sintering of dual-phase, high-entropy boride–carbide ceramics.