Increasing recycling in office environments: The effects of specific, informative cues

We investigated the effects of prompts on the recycling behavior of approximately 217 faculty, staff, and graduate students in two academic departments of a large university. During the intervention, two signs were posted in each department. One sign prompted recycling (posted above the recycling receptacle), and the other sign prompted proper disposal of trash (posted above the trash receptacle). Results of a multiple baseline design across the two departments indicated that the sign prompt increased recycling behavior. Installation of the sign prompts in close proximity to receptacles in Department A resulted in a 54% improvement over baseline. Posting of sign prompts over containers 4 m apart in Department B resulted in a 17% improvement, whereas positioning the signs and receptacles in close proximity resulted in a 29% improvement over baseline.     

Why do salmon go upstream in fresh water from oceans: Evolution of the global recycling of nutrients through higher organisms

The quasi‐homogeneous cold water mass lying deeper than 1000 m below sea level serves as a sink for, and hence is rich in, inorganic nutrients, including nitrates and above all phosphates, which, directly or through numerous food chains, have found their way to the ocean bottom. This cold water mass surfaces during the cold season in temperate zones and permanently in arctic/antarctic zones, which could support extremely rich marine life permitted by relatively low temperatures. Such fruits de mer are predated by rich marine faunas of local and migrating mammals and birds. As for the migrating birds, they breed during the short summer in both circumpolar zones of the earth, to bring the newly acquired biomaterial including inorganic matter to their overwintering sites of the temperate/ subtropical region. Through food chains mainly involving birds and insects, the nutrients accumulated in the deep sea waters would thus be brought back to the land, upwards even to the high mountains. A similar role may be attributed to salmonids and their southern hemisphere counterparts.

In the case of woodland birds, an estimate made in Japan indicates that ca. 10 tons per km2 of insects support the total insectivorous bird lives of the area. This figure may approximately be used as an index of the inorganic nutrients to be returned per annum to the soil through bird droppings and corpses. Using the number of salmonids caught during the peak period of the highly exploitative fishery perpetrated by Japanese fishing boats around 1910 near the mouth of Amur River, I estimate possible biomass contribution to the land from the sea by salmon returning to the upstream of the Amur in wilderness (ca. 6000 tons per annum). According to Arsen'ev (1930), a school of salmons swimming upstream became a victim of active predation by mammals and birds in the mountains. Whereas the total length of the main path of the Amur beyond the junction of Shilka and Onon Rivers is ca. 4000 km, the total contribution of biomass (and hence inorganic material) by salmonid fish to land would amount to, using the above index for birds’ annual predation of insects per unit area, an equivalent of 100 m‐wide zone along streams of a total length of at least 60,000 km, a distance which would cover a good part of smaller tributary currents of the Amur.

The coevolution of nutrient recycling through organism's migration throughout the global ecosystem would be difficult to explain by natural selection, because there cannot be competition for improvement with the unique system of global redistribution of nutrient materials. Also the time scale needed to bring about selection would by far exceed the generation time of organisms involved.     

Newly observed microscopic planar defects on {111} in natural diamond

Abstract

Circular disc-crack-like defects randomly distributed on {111} planes have been discovered by 300kV transmission electron microscopy in diamond that had crystallized on non-faceted growth surfaces of mean orientation {100}. In a sample of ～ 100 defects, disc diameters were narrowly distributed about a mean of 1·2 μm and one in seven discs were located on a coplanar stacking fault of average diameter 2 μm. Discs totally enclosed within the specimen exhibit concentric moiré fringes covering their image areas when viewed obliquely, showing them to be dilated into thin lenticles. Internal pressures, deduced from moiré-fringe counts on six lenticles, were in the range 1·5 to 1·8 GPa.     

Influence of heat treatment on the microstructural evolution of Al–3 wt.% Cu during high-pressure torsion

Solution-treated, peak-aged and overaged samples of the model alloy Al–3?wt.% Cu, obtained by selective heat treatments of the pre-material, have been subjected to high-pressure torsion at room temperature and at 200?°C. The mechanical behaviour of the samples was investigated with torque measurements during deformation and microhardness measurements after deformation. Irrespective of the initial material condition, in the saturation regime a comparable equilibrium microstructure was found consisting of ultrafine aluminium grains stabilized by precipitates formed at grain boundaries.     

Effect of severe plastic deformation on the coercivity of Co–Cu alloys

Cast Co–5.6 wt% Cu and Co–13.6 wt% Cu alloys were subjected to severe plastic deformation (SPD) by high-pressure torsion (HPT). The HPT treatment drastically decreases the size of the Co grains (from 20 µm to 100 nm) and the Cu precipitates (from 2 µm to 10 nm). As a result, the coercivity H _c of both the alloys radically increases. The saturation magnetization, M _s, remains almost unchanged. Thus, SPD of the bulk samples opens the way for drastic increase in the coercivity for the Co-based alloys.     

Observation of planar stacking faults in a Ti-rich two-phase Ti-Al alloy after deformation at elevated temperatures

It is a common observation that in two-phase Ti-Al-based binary alloys, deformation of the gamma phase occurs by 1/2<110]-type ordinary dis-location activity and twinning associated with 1/6<112] type partials. In the present study the microstructure of a new Ti-Al-based alloy (Ti-47at.% Al-2at.%Mn-2at.%Nb+ 0.8 vol.% TiB₂) with a duplex microstructure consisting of primary equiaxed gamma grains and lamellar alpha₂+ gamma colonies was studied by transmission electron microscopy (TEM) after deformation at elevated temperatures. Planar stacking faults were found in the gamma laths. A detailed contrast analysis by TEM shows that these planar stacking faults lying on {111} planes are bound by all the fcc variants of the Shockley partial dislocations of type 1/6<121>, in contrast with the observations in stoichiometric binary TiAl alloys, where only 1/6<112]-type Shockley partials are found to be associated with the true twins. It is proposed that the addition of ternary and quaternary elements such as Mn and Nb promotes the other variants of the fcc-like dissociations (not common in L1₀structure) in the present alloy.     

A model for 〈c+a〉 dislocation transmission across nano-spaced parallel basal stacking faults in a HCP alloy

We develop a model for recently observed 〈c + a〉 dislocation transmission across nano-spaced parallel basal stacking faults in hexagonal close-packed (HCP) Mg microcrystalline grains. The model theoretically predicts nanospace-dependent yield strength that is in good agreement with experimental data. Additionally, it theoretically predicts activation volume and strain rate sensitivity.     

Incorporating environmental ethics into the undergraduate engineering curriculum

The design and economic realities associated with Personal Computers (PCs) was used as a model for implementing ethical issues into the core-engineering curriculum. Historically, products have not been designed to be recycled easily. By incorporating environmental ethics into our classrooms and industries, valuable materials can be recovered and harmful materials can be eliminated from our waste stream. Future engineers must consider the economic cost-benefit analysis of designing a product for easy material recovery and recycling versus the true cost of the disposal and continued use of virgin materials. A three hour unit on the economic and environmental impacts of product design is proposed for inclusion in the ABET accredited engineering program. An earlier version of this paper was presented at the “Ethics and Social Responsibility in Engineering and Technology” meeting, New Orleans, 2003.     

整形美容外科年轻医师的人文修炼

我国整形美容外科在迅速发展的同时还存在许多弊病,为了促进学科整体健康快速发展,整形美容外科的年轻医师除了精进专业技术,还必须进行必要的人文修炼。本文介绍并分析了整形美容外科面临的五个人文困境,指出整形美容外科年轻医师具有进行人文修炼的必要性,并提出人文修炼的三条途径。     

Equivalent and effective strains during severe plastic deformation (SPD)

ABSTRACT

This paper considers the characteristics of severe plastic deformation (SPD) to estimate its efficacy and to compare different processing techniques. In contrast to effective strains by von Mises and Hencky, the rotation component of the strain rate is included in the analysis as a mode of deformation, which ranges from simple shear to pure shear. Distortions of material elements during a uniform plane plastic flow are calculated using a kinematic approach. For the fixed deformation mode, the current state is defined by the accumulated shears that are identical to the von Mises effective shear strains. In specific cases of pure shear and simple shear, the accumulated shears match the specific distortions of round or square elements prescribed by Hencky or von Mises approach, respectively. The mode of deformation is important to the structural effects of SPD. In general, two separated characteristics, accumulated shear and the coefficient of deformation mode, are necessary to describe strains during SPD.