The impact and recovery of asteroid 2008 TC3

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995nm wavelength range, and designated 2008 TC3 (refs 4-6). It subsequently hit the Earth. Because it exploded at 37km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.

The application of colloidal gas aphrons in the recovery of fine cellulose fibres from paper mill wastewater

Colloidal gas aphrons (CGAs) are micron-sized gas bubbles of 25–30 µm in diameter produced by a high-speed stirrer in a vessel containing dilute surfactant solution. These bubbles, because of their small size, exhibit some colloidal properties. In this work, CGAs were used to separate fine fibres from a lean slurry of cellulosic pulp in a flotation column. The pulp fibres were recovered as foamate from the top. Sodium dodecyl sulphate at a concentration of 2.0 kg/m3 was used as a surfactant to generate the CGAs in a spinning disc apparatus. The results indicated that up to 70% flotation efficiency could be obtained within a short column height of 0.3–0.35 m. This technique can be applied to recover fine cellulosic pulp from paper-machine backwater.

Recovery from brain injury: Finding the missing bits of the puzzle

Background: One basic problem found during rehabilitation is that people with brain injuries lack awareness of their difficulties. Research into this phenomenon has often disregarded the voices of those affected by the trauma and do not give an insider's perspective on the process through which a person with a brain injury develops awareness of their difficulties.

Methadone as Social Control: Institutionalized Stigma and the Prospect of Recovery

Methadone maintenance treatment (MMT) is an intervention used to treat opioid (heroin) dependence. Several investigators have found that MMT is effective in reducing heroin use and other behaviors; however, a disproportionate number of MMT clients leave treatment prematurely. Moreover, MMT outcome variables are often limited in terms of their measurement. Utilizing an integrated theoretical framework of social control and stigma, we focused on the experiences of methadone maintenance from the perspective of clients. We pooled interview data from four qualitative studies in two jurisdictions and found linkages between social control and institutional stigma that serve to reinforce "addict" identities, expose undeserving customers to the public gaze, and encourage clients to be passive recipients of treatment. We discuss the implications for recovery and suggest recommendations for change.