A closed-loop electrogenerative recycling process for recovery of silver from a diluted cyanide solution.

A closed-loop process for the complete recovery of silver from a diluted silver cyanide solution has been constructed based on an electrogenerative process. It was shown that the reduction of silver was a mass transport controlled process. Under optimal experimental conditions, 100% of silver was recovered from 500 mg L-1 and 100 mg L-1 silver cyanide solutions by using a reticulated vitreous electrode (RVC) as the cathode. The cyanide solution was recycled and reused so that a closed-loop process was obtained. In addition, the RVC in this study can be used repeatedly up to 10 cycles with a calculated relative standard deviation of 1.90%.

Is knowledge a barrier to implementing low back pain guidelines? Assessing the knowledge of Israeli family doctors.

OBJECTIVES: To measure knowledge of Israeli low back pain (LBP) clinical practice guidelines among different subgroups of primary care doctors, prior to designing an intervention programme to enhance guideline adherence in practice. STUDY DESIGN: Confidential mailed survey questionnaire. SETTING: Family practices in the Haifa and western Galilee district, Israel. PARTICIPANTS: Random sample of 163 primary care doctors. A total of 134 doctors (82%) completed the questionnaire. MAIN OUTCOME MEASURES: A Multiple Choice Questionnaire measuring knowledge of the LBP guidelines. Instrument reliability and inter-item reliability were tested in a pilot phase. Content validity was assured by having the Israeli LBP guideline authors involved in a consensus procedure. RESULTS: Distribution of test scores significantly differentiated professional levels and background variables, demonstrating the instrument reliability. Cronbach's alpha was above 0.91. The average test score was 67.7 [standard deviation (SD) 16.2], family doctors had average scores of 75.2 (SD 9.8), general practitioners (GPs) 57.9 (SD 19) and family practice residents 67.4 (SD 13.2). The difference between the test average scores of family doctors, GPs and residents was significant (P < 0.001). Significant differences were also found for specific variables including the doctor's age, country of medical training and self-report familiarity with the LBP guidelines. CONCLUSIONS: Striking differences exist between subgroups of primary care doctors regarding their knowledge of LBP guidelines. These differences will require the design of multiple interventions tailored to each subgroup.