Effect of temperature on fermentation kinetics of waste sulphite liquor by Saccharomyces cerevisiae

The optimum operating temperatures for the maximum production of ethanol and the maximum utilization of substrate in batch fermentations of a waste sulphite liquor (WSL) as well as a synthetic medium using Saccharomyces cerevisiae were determined. The fastest consumption of substrate resulting in the shortest fermentation times of 13 h and 45 h was achieved at 35°C and 30°C for the synthetic medium and the WSL, respectively. The concentrations of ethanol in the two media were also maximum under these conditions: 11.6g dm^?3 and 9.4 g dm^?3 for the synthetic medium and the WSL, respectively. The productivities of biomass and ethanol increased with the increase of temperature and reached maximum values of 0.89 g dm^?3 h^?1 and 0.21 g dm^?3 h^?1 in the synthetic medium and the WSL, respectively. The inhibiting agents in the waste sulphite liquor affected the metabolic rates of microbial activities and prolonged the overall fermentation time while decreasing the productivities of biomass and ethanol. From analysis of the fermentation kinetics a mathematical model based on the Monod model was developed to describe the cellular growth and ethanol production. The model included inhibition terms for ethanol and the inhibiting agents in the waste liquor. The temperature dependence of the model parameters followed the Arrhenius law for temperatures between 15°C and 35°C. The activation energies (E) and the frequency constants (A) of these parameters were also determined.     

Axial pressure profiles in non-newtonian flow: Part II: Viscometric flow and relaxation phenomena analyses

Extensive pressure profile data were compiled for a 16.5% polyisobutylene solution in mineral spirits. Values of stored elastic energy obtained from these data compare favorably with those ascertained from die swell and from entrance correction methods. The viscometric normal stress differences were significantly larger than the shear stress and, particularly, the second normal stress rose to a maximum where it was an order of magnitude larger than the first normal stress difference. Time constants calculated from swell decay and entrance-borne elastic stress relaxation are essentially the same and show an approximate inverse relation to the shear rate.     

Submolecular potential profiling across organic monolayers

Potential profiles across molecular layers are constructed by means of noncontact electrically stimulated photoelectron spectroscopy, probing for the first time the molecule-substrate interface potential and resolving local screening effects across inner phenyl groups.     

EquiCast: Scalable multicast with selfish users

Peer-to-peer (P2P) networks suffer from the problem of “freeloaders”, i.e., users who consume resources without contributing anything in return. In this paper, we tackle this problem taking a game theoretic perspective by modeling the system as a non-cooperative game. We introduce EquiCast, a wide-area P2P multicast protocol for large groups of selfish nodes. EquiCast is the first P2P multicast protocol that is formally proven to enforce cooperation in selfish environments. Additionally, we prove that EquiCast incurs a low constant load on each user.     

A scalable lock-free stack algorithm

The literature describes two high performance concurrent stack algorithms based on combining funnels and elimination trees. Unfortunately, the funnels are linearizable but blocking, and the elimination trees are non-blocking but not linearizable. Neither is used in practice since they perform well only at exceptionally high loads. The literature also describes a simple lock-free linearizable stack algorithm that works at low loads but does not scale as the load increases. The question of designing a stack algorithm that is non-blocking, linearizable, and scales well throughout the concurrency range, has thus remained open.     

Performance evaluation of the BioCAST technology: a new multi-zone wastewater treatment system

A new wastewater treatment technology, called BioCAST, has been designed and developed for high rate and simultaneous removal of organic carbonaceous compounds as well as nitrogen and phosphorus, along with reduced sludge generation. The treatment system has two interlinked reactors containing four independent zones with different environmental conditions of aerobic, microaerophilic, anoxic and anaerobic for the biological treatment of wastewater, as well as two clarification zones and a filtration unit for solid-liquid separation. The treatment system contains suspended as well as fixed-film microorganisms. The performance evaluation of the BioCAST system was carried out at organic loading rates of 0.95 to 1.86 kg/m(3) d, and nitrogen and phosphorus loading rates of 0.02 to 0.08 kg/m(3) d and 0.014 to 0.02 kg/m(3) d, respectively. The results demonstrated high removal efficiencies of carbon and nitrogen throughout the operation period, reaching 98.9 and 98.3%, respectively. Phosphorus removal efficiency was lower than 50% during the first 160 days of operation but it increased with the increase of nitrogen loading rate above 0.05 kg/m(3) day and concomitant reduction of C/N ratio below 15. Phosphorus removal efficiency reached 94.1%, producing an effluent concentration of 1.4 mg/L after 225 days of operation. The overall biomass yield based on the consumed COD was 3.7%.     

Message delay and DisCSP search algorithms

Distributed constraint satisfaction problems (DisCSPs) are composed of agents, each holding its own variables, that are connected by constraints to variables of other agents. Due to the distributed nature of the problem, message delay can have unexpected effects on the behavior of distributed search algorithms on DisCSPs. This has been recently shown in experimental studies of asynchronous backtracking algorithms (Bejar et al., Artif. Intell., 161:117–148, 2005; Silaghi and Faltings, Artif. Intell., 161:25–54, 2005). To evaluate the impact of message delay on the run of DisCSP search algorithms, a model for distributed performance measures is presented. The model counts the number of non concurrent constraints checks, to arrive at a solution, as a non concurrent measure of distributed computation. A simpler version measures distributed computation cost by the non-concurrent number of steps of computation. An algorithm for computing these distributed measures of computational effort is described. The realization of the model for measuring performance of distributed search algorithms is a simulator which includes the cost of message delays. Two families of distributed search algorithms on DisCSPs are investigated. Algorithms that run a single search process, and multiple search processes algorithms. The two families of algorithms are described and associated with existing algorithms. The performance of three representative algorithms of these two families is measured on randomly generated instances of DisCSPs with delayed messages. The delay of messages is found to have a strong negative effect on single search process algorithms, whether synchronous or asynchronous. Multi search process algorithms, on the other hand, are affected very lightly by message delay.     

Psychoanalytic supervision and the need to be alone.

Argues that just as infants not left alone (in the marginal presence of their mothers) will not find their true selves, but will develop false selves with conformative tendencies (D. W. Winnicott, 1965), supervisees not left to discover their professional selves in the marginal presence of their supervisors will not develop true professional selves. A false self will then emerge in the place of an authentically experiencing one. This false self will conform to the perceived needs and demands of supervisors, teachers, and various clinical tests. Supervisors must balance the welfare of the patient with the professional developmental needs of the supervisee. A case study is presented as illustrative. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of dietary calcium on blood lead concentrations in occupationally exposed and nonexposed workers

PURPOSE: Evaluation of night glare after excimer laser in situ keratomileusis (LASIK) using two different ablation zone diameters. METHODS: One hundred and twenty eyes of 60 consecutive myopic patients received LASIK with the Nidek EC-5000 excimer laser. Eyes were randomized so that every patient had a single ablation zone of 5.5 mm on one eye and an ablation zone of 5.5 mm with a transition zone of 1.0 mm diameter larger on the other eye. Night glare was measured by two methods; a spot light test and a subjective questionnaire. RESULTS: At 6 months, 54 patients (90%) were examined; results of the spot light test showed that 40 patients (74.1%) perceived more glare with the eye with the single ablation zone; the subjective questionnaire indicated that 22 patients (40.7%) had more night glare with the eye with a single ablation zone compared to the other eye. The use of the transition zone increased the required total ablation depth by 20%. CONCLUSION: The use of a peripheral transition 1.0 mm diameter larger than the ablation zone significantly decreased night glare after LASIK with slight increase in the required central ablation depth.