Can a wastewater treatment plant be a powerplant? A case study

Today wastewater treatment plants are evaluated not only in terms of their treatment efficiency but also concerning their energy efficiency. Increasing energy efficiency can be realized either through operational optimisation or by realising an already existing potential for energy generation on-site. The main source of energy at a municipal wastewater treatment plant is the biogas produced in the anaerobic sludge digester. Studies indicate excess digester capacities of about 20% in Germany available for co-fermentation of organic substrates other than sewage sludge. This paper presents an example of a municipal wastewater treatment plant going towards an energy self-sufficient operation and even a surplus energy production as the result of an increasing co-fermentation of sludge from grease skimming tanks. In 2005 on average 113% of the electricity consumed for plant operation was generated on-site in gas engines. Co-fermentation of about 30% (related to the total dry residue input) of grease interceptor sludge in the presented case does not only effect a 4-times increased gas yield, but also an intensified 20% higher anaerobic degradation of the organic matter of the sewage sludge and thus having a positive influence not only on the energy and financial balance but also on the anaerobic sludge stabilisation with respect to the degradation degree of the organic fraction.     

Developing a culture of lifelong learning in a library environment

Between 1995 and 1996, the Annette and Irwin Eskind Biomedical Library (EBL) at Vanderbilt University Medical Center (VUMC) radically revised the model of service it provides to the VUMC community. An in-depth training program was developed for librarians, who began to migrate to clinical settings and establish clinical librarianship and information brokerage services beyond the library's walls. To ensure that excellent service would continue within the library, EBL's training program was adapted for library assistants, providing them with access to information about a wide variety of work roles and processes over a four to eight-month training period. Concurrently, customer service areas were reorganized so that any question--whether reference or circulation--could be answered at any of four service points, eliminating the practice of passing customers from person to person between the reference and circulation desks. To provide an incentive for highly trained library assistants to remain at EBL, management and library assistants worked together to redesign the career pathway based on defined stages of achievement, self-directed participation in library-wide projects, and demonstrated commitment to lifelong learning. Education and training were the fundamental principles at the center of all this activity.     

Zur Erkennung dauererhitzter Milch

Ohne Zusammenfassung     

A feedforward decoupling concept for the control of elastic robots

A reference-oriented procedure for controlling elastic robots is presented. This affords, in a first step, an optimal path planning method generating the reference trajectory. It will be realized by a classical feedforward decoupling scheme. The elastic deviations from this reference are corrected within the feedforward loop by calculation of the joint correction angles putting back the endpoint to its nominal position. In a final step, elastic vibrations of the arms are damped by an additional joint output control system, which uses as an input joint kinematics and strain gauge measurements of the elastic curvatures. The concept has been realized for a laboratory manipulator. Theory and experiments agree very well.     

Enzyme-linked immunosorbent assay of epidermal growth factor receptor in lung cancer: comparisons with immunohistochemistry, clinicopathological features and prognosis

PURPOSE: Cyclosporine-A (CSA) combined with corticosteroid therapy was administered to 12 patients with severe Beh?et's uveitis who were resistant to colchicine or cytotoxic therapy. METHODS: Previous colchicine or cytotoxic therapies were tapered off one month before CSA therapy. All patients were started on an initial oral dose of 5 mg/kg/day of CSA. After the first three months, the CSA dose was reduced to a maintenance dose according to the intraocular inflammatory response. RESULTS: The average follow-up period was 20 (12-36) months. Visual acuity remained the same in 12 (%54.5) and improved in 8 (%36.4) eyes. There was a decrease in the frequency (p<0.01) and severity (p<0.01) of ocular attacks and in the maintenance steroid dose (p<0.01) when compared with conventional therapy. The frequent side effects were paraesthesia-hyperesthesia, fatigue, nausea, hirsutism and dose-related nephrotoxicity in one patient. CONCLUSION: The results of the study suggest that low dose CSA combined with low dose corticosteroid may be an effective therapeutic alternative in the treatment of severe refractory Beh?et's uveitis.     

Proton selective substate of the mitochondrial permeability transition pore: regulation by the redox state of the electron transport chain

The permeability transition pore of rat liver mitochondria can be closed by chelating free Ca2+, with respect to the passage of large molecules such as mannitol and sucrose. However, an apparent H+-conducting substate remains open under these conditions, as indicated by the persistence of maximal O2 consumption rates and by the failure to recover a membrane potential. Agents which favor a closed pore, such as cyclosporin A, ADP, Mg2+, or bovine serum albumin, do not close the H+-conducting substate, but it closes spontaneously when respiration becomes limited by the availability of O2. Closure provoked by an O2 limitation requires free Mg2+ in the sub-micromolar concentration range and becomes less efficient with increasing time spent in the presence of free Ca2+. The H+-conducting substate is apparently regulated by the redox status of the electron transport chain, with a reduced form favoring closure. A physical association (or equivalence) between the pore and one of the respiratory chain complexes is supported. These characteristics suggest that the transition is irreversible in vivo, if it involves a small fraction of total mitochondria, and would lead to their elimination and/or replacement by the cell. The implications of this proposal are considered, as they relate to a possible role for the transition in cellular apoptosis and the elimination of mitochondria containing mutated DNA.     

Determination of zinc in fingernails by non-flame atomic absorption spectroscopy

The determination of Zn in fingernails directly using the graphite furnace presented certain difficulties due to the anomalous behavior of the analyte in the furnace. The appearance of two peaks which were due to Zn and not to any background interference was noted. The Zn value obtained by adding the area of these two peaks compared fairly well with Zn levels determined by wet ashing and subsequent determination either in the furnace or flame. Wet ashed samples gave only a single peak. It was possible to produce a model of the phenomenon with various Zn salts in a non aqueous matrix. Under these conditions ZnSO4 and ZnO gave a discretely different peak from ZnC12 or metallic Zn. Several tissues such as serum, whole blood, cuticle, and hair were examined for multiple peak formation. Direct determination of Zn in fingernails with the graphite furnace is possible for certain applications such as the determination of Zn levels of white spots in fingernails. For this purpose it is possible to use a sample size as small as 20 mug using the 2138 Zn line. This allows one to run several determinations on a single white spot. However, where sample size is not a limitation, wet ash digestion prior to determination in the furnace is probably the preferred procedure.