Drastic Shock Research Articles

A comprehensive comparison between halophilic granular and flocculent sludge in withstanding short and long-term salinity fluctuations

The effects of salinity fluctuations on the activity of autochthonous halophilic bacteria in aerobic granular sludge (AGS) and flocculent activated sludge (FAS) reactors were investigated. The response of nitrifiers and denitrifiers activity to drastic and moderate salinity shocks in the short-term (ST) and long-term (LT) was examined.The BOD5 removal efficiency decreased only in the reactors subjected to the drastic LT salinity increase. Nevertheless, stable performances were achieved 18 days after the shock in the AGS-R1 (90%), whereas after 27 days in the FAS-R1 (82%).The loss in nitritation efficiency was higher in the FAS reactors and was proportional to the shock intensity. Nitritation activity collapsed from approximately 3.8 mgNH4-N gVSS−1 h−1 to 0.73 mgNH4-N gVSS−1 h−1 and from 4.5 mgNH4-N gVSS−1 h−1 to 0.24 mgNH4-N gVSS−1 h−1 in the AGS-R1 and FAS-R1, respectively, even if the ammonium oxidation capacity did not completely disappeared. Denitritation activity decreased from 11.44 mgNO2-N gVSS−1 h−1 to 3.93 mgNO2-N gVSS−1 h−1 in the AGS-R1 at steady state, whereas in the FAS-R1, it decreased from 12.53 mgNO2-N gVSS−1 h−1 to 2.09 mgNO2-N gVSS−1 h−1.Nitritation and denitritation were completely restored 5 days after ST shock. No significant effects were observed after the moderate shock.The changes in the total EPS content were lower than 10%, therefore, it was considered negligible. Only drastic shocks caused significant changes in the EPS structure, with an increase of the loosely-bound by 45% in the AGS and 55% in the FAS.

Humphrey's Legacy: Loss and Recall

Until I became involved in dance, I believed that art is public property. It seemed there was a definite connection between the personal, even intimate character of the artist's process and the generosity with which he or she relinquishes a work when it is completed. This interchange might partly define the altruism that people have associated with artists—up to the twentieth century anyway.Since the last millenium, Western culture has undergone many drastic shocks that have redefined the transaction known as artmaking. Mechanical and electronic reproduction techniques have put the uniqueness of the art object into question. They have transformed visual arts and music into commodities—”cheapened” them by diminishing their exclusivity and multiplying the number of people who can enjoy them. Yet dance continues to elude capture by the potent, ever-present media of films, video and computers. A dance is still a singular event—but, it seems to me, one that's even more vulnerable now to disappearance. Dance images submerge almost instantly in the flood of other visual stimuli that's constantly washing over us; dance is everywhere but the choreographic entity has resisted translation to film. As an inherently live phenomenon dance preserves its aura of spontaneity and surprise, but it loses some of the visibility, and the standards and protections, that benefit artworks with a more permanent format.