Hydrometallurgical recovery of zinc from ashes of automobile tire wastes

Study has been performed on the investigation of metal leaching behavior for fly and bottom ashes from automobile tire wastes using acid and alkaline solutions from both viewpoints of environmental protection and resource utilization. The two ashes were found to contain substantial amounts of zinc and iron along with small quantities of cobalt, manganese, magnesium, copper, titanium and aluminum. The fly ash contained a much larger amount of zinc than the bottom ash, and seems to be a promising secondary source for the metal. Effects of such experimental parameters as temperature, time and solid-liquid ratio on the leaching behavior were investigated. Using three mineral acids and citric acid, selective leaching of zinc was successfully attained; the concentration of zinc in the leach liquors from the fly ash reached as high as 20 g l(-1) while the iron leaching was much suppressed. Selective separation of zinc was also attained in the leaching with alkaline solutions, though the percent leaching was lower than that in the acid leaching. Moreover, solvent extraction and precipitation were applied to the metal-loaded leach liquors as downstream processing to evaluate the feasibility of zinc recovery.     

Metabolism and body composition of a copepod (<Emphasis Type="Italic">Neocalanus cristatus</Emphasis>: Crustacea) from the bathypelagic zone of the Oyashio region,western subarctic Pacific

Metabolism [respiratory oxygen consumption, electron-transfer-system (ETS) activity] and body composition [water, ash, carbon (C), nitrogen (N), carbon/nitrogen (C/N) ratio] of stage C5/C6 Neocalanus cristatus from 1000 to 2000 m depth of the Oyashio region, western subarctic Pacific, were determined during the period of July 2000 through June 2003. Compared with the C5 specimens from shallow depths (<250 m), those from 1000 to 2000 m were characterized by quiescent behavior, reduced respiration rates (30% of the rates at active feeding), very low water content (61–70% of wet weight), but high C content (56–64% of dry weight) and C/N ratios (7.2–10.6, by weight). Artifacts due to the recovery of live specimens from the bathypelagic zone appeared to be unlikely in this study, as judged by the consistent results between re-compression (100 atm) and non-compression (1 atm) respiration experiments, and between ETS activities and respiration rates directly measured. In addition, the respiration rates of C6 males and females of N. cristatus from the same 1000–2000 m depth were two to three times higher than the rates of C5 individuals, but were similar to the rates of a bathypelagic copepod, Paraeuchaeta rubra. Combining these results with literature data, C budgets of: (1) diapausing C5 specimens, weighing 6–10 mg dry weight; (2) molt to C6 females; and (3) the complete the life span were established, taking into account assorted losses in respiration during diapause at stages C5 and C6, molt production and egg production. Respiratory C losses by C5 and C6 specimens were estimated on the basis of body N as adjusted metabolic rates [AMR; µl O₂ (mg body N)^–0.843 h^–1], then N budgets were also computed subtracting N lost in the form of cast molts and eggs from the initial stock. Calculations revealed that allocation of the C stock was greatest to egg production (34–57%), followed by respiration (27%) and cast molts (3%), leaving residual C of 13–36% in spent C6 females. The present results for N. cristatus from the North Pacific are compared with those of Calanus spp. in the North Atlantic.Communicated by O. Kinne, Oldendorf/Luhe     

Cementation vs mobility: development of a cemented byssus and flexible mobility in Anomia chinensis

The mobility of Anomia chinensis Philippi was studied in relation to its byssal development stage. This species shows high mobility even after it begins cementation in its post-larval stage. Juveniles develop a calcified byssus in the post-larval stage and cement to substrata. However, juveniles up to about 10 mm in shell length can relocate by repeating a sequence of formation of the calcified byssus, abandonment of it, locomotion by crawling, reattachment, and recementation. Juvenile anomiids up to 25 mm in shell length also can move, without breaking their byssal attachments, by shifting the center of byssal calcification dorsally. Even an adult can change its orientation by forming a twisted byssus. These possible methods of movement are closely related to five stages of byssal development. Anomiids can use this mobility to seek a preferable position for attachment after initial cementation, or to adjust their orientation, and thus promote higher survivorship. Received: 18 August 1997 / Accepted: 19 July 1998     

The generative power of metaphor: long‐term action research on disaster recovery in a small Japanese village

Disaster recovery is a dynamic process of creating, maintaining, and changing the meaningful context of survivors. It is completed when they redevelop their self‐reliance and resume managing their social relations with a sense of community. This study employed action research to examine how researchers and survivors collaborated to change disaster recovery through the generative power of metaphor in a small village in Japan that experienced the Niigata–Chuetsu earthquake on 23 October 2004. It outlines long‐term collaborative practices as survivors undertook new activities owing to the power of the metaphor of ‘school’. Once ‘school’ was adopted as the metaphor for where survivors learnt new skills and passed on traditional knowledge, they created new metaphors and performed new activities independently, which is critical for recovery as it demonstrates self‐reliance. The paper assesses the reasons why generative metaphors worked effectively in this case and highlights some academic and practical implications for disaster recovery.     

Growth and reproductive cycles of the marine fouling ascidians Ciona intestinalis,Styela plicata,Botrylloides violaceus,and Leptoclinum mitsukurii at Aburatsubo-Moroiso Inlet (central Japan)

Experimental cultivations of post-metamorphosis juveniles were repeated in different seasons for Ciona intestinalis (L.) and Styela plicata (Lesueur) (simple ascidians) as well as for Leptolinum mitsukurii (Oka) and Botrylloides violaceus Oka (compound ascidians) at Aburatsubo-Moroiso Inlet near Misaki Biological Station (Japan). Growth in body length of simple ascidians was exponential during juvenile development up to near sexual maturity. C. intestinalis grew to sexual maturity in 1 month in summer and in 2 months in winter; S. plicata, in 2 months in summer and in nearly 5 months in winter. The doubling time decreased approximately twofold in the two simple ascidians with a 10C° increase in environmental temperature. Growth of colonies in compound ascidians was exponential after maturation of the first functional zooids. Sexual reproduction of L. mitsukurii and B. violaceus was continuous throughout the year, forming many generations in a year. Doubling time of colony growth in the two compound ascidians decreased approximately threefold with a 10C° increase in temperature.