Joint entropy and multi-objective evolutionary optimization of water distribution networks

It is essential to consider resilience when designing any water distribution network and surrogate measures of resilience are used frequently as accurate measures often impose prohibitive computational demands in optimization algorithms. Previous design optimization algorithms based on flow entropy have essentially employed a single loading condition because the flow entropy concept formally has not been extended to multiple loading conditions in water distribution networks. However, in practice, water distribution networks must satisfy multiple loading conditions. The aim of the research was to close the gap between the prevailing entropy-based design optimization approaches based on one loading condition essentially and water distribution practice that must address multiple loading conditions. A methodology was developed and applied to a real-world water distribution network in the literature, based on the concept of the joint entropy of independent probability schemes. The results demonstrated that the critical loading conditions were design specific. In other words, the critical loading and operating conditions cannot readily be determined beforehand. Consequently, maximizing the joint entropy provided the most consistently competitive solutions in terms of the balance between cost and resilience. The results were derived using a penalty-free genetic algorithm with three objectives. Compared to previous research using flow entropy based on a single loading condition and two objectives, there was a substantial increase of 274% in the number of non-dominated solutions achieved

Entropy maximizing evolutionary design optimization of water distribution networks under multiple operating conditions

The informational entropy model for flow networks was formulated over 30 years ago by Tanyimboh and Templeman (University of Liverpool, UK) for a single discrete operating condition that typically comprises the maximum daily demands and was undefined for water distribution networks (WDNs) under multiple operating conditions. Its extension to include multiple independent discrete operating conditions was investigated experimentally herein considering the relationships between flow entropy and hydraulic capacity reliability and redundancy. A novel penalty-free multi-objective genetic algorithm was developed to minimize the initial construction cost and maximize the flow entropy subject to the design constraints. Furthermore, optimized designs derived from the maximum daily demands as a single discrete operating condition were compared to those derived from a combination of discrete operating conditions. Optimized designs from a combination of discrete operating conditions outperformed those from a single operating condition in terms of performance and initial construction cost. The best results overall were achieved by maximizing the sum of the flow entropies of the discrete operating conditions. The logical inference from the results is that the flow entropy of multiple discrete operating conditions is the sum of their respective entropies. In addition, a crucial property of the resulting flow entropy model is that it is bias free with respect to the individual operating conditions; hitherto a fundamental weakness concerning the practical application of the flow entropy model to WDNs is thus addressed

Photochemical modification of polysulfone

Badano zmiany związane z fotochemiczną modyfikacją polisulfonu w oparciu o analizę spektralną naświetlanych próbek. Stwierdzono tworzenie połączeń karbonylowych, grup hydroksylowych a także obniżenie ilości grup eterowych i sulfonowych, które związane jest z degradacją polimeru. Obserwowany wzrost absorbancji w zakresie długofalowej części zakresu UV (?>290 nm) przypisano tworzeniu się sprzężonych struktur polifenylowych.The changes resulting from the photochemical modification of polysulfone were examined with the use of spectroscopic analysis of irradiated samples. The formation of carbonyl and hydroxyl groups in irradiated films and the reduction of the amount of ether and sulfone groups, connected with the degradation of the polymer were observed. The increase of the long wave UV absorption (?>290 nm) was attributed to the formation of polyphenyl conjugated structures

Digital Workflow for Prosthetically Driven Implants Placement and Digital Cross Mounting: A Retrospective Case Series

Fully digital workflow in implant dentistry is ever increasing. Treatment of partial edentulous cases is well-documented; nevertheless, complete edentulous cases are still a challenge. To present several innovations in the treatment of complete edentulous patients using digital solutions, both for implant placement and restoration delivery, was the objective of this study. It was designed as a retrospective case series study, aimed to tune further research with larger sample size, and a longer follow-up. Patients requiring complete, implant-supported restoration were asked to participate in this study. Enrolled patients were treated with four implants, immediate loading and a definitive complete arch restoration. Patients were treated using computer-assisted, template-based surgery. Multi-piece surgical templates were used to accurately place the implants, to manage the bone if needed and to make immediate loading procedure quicker and easier. After osseointegration period, definitive, extra-oral, digital impressions were taken using newly developed scan analogs, connected in the patient mouth using temporary cylinders and stabilized by means of the low-shrinkage, flowable, resin composite. Outcomes were implant and prosthesis survival rate, complications, accuracy, and patient satisfaction. Radiographic evaluation performed with a preliminary, radiopaque aluminum try-in, was used to test the accuracy of the digital impressions. Overall, 20 implants were placed in five patients. All the implants osseointegrated without complications. One impression was taken a second time due to inaccuracy of the aluminum tray-in. Finally, all of the patients were completely satisfied with both surgical and prosthetic procedures. Within the limitations of this case series, multi-piece surgical templates showed promising results improving the clinician’s confidence in the case of bone reduction, post-extractive implants and immediate loading. The prosthetic template increased the trueness of the digital impression for complete edentulous patients. Finally, even if an impression was performed again, the scan-analog used for extra-oral chair-side digital impressions seemed to be a promising tool. Continuous improvements and further study are needed to confirm these preliminary results

Comparison Between Single Early-loaded Implants With Sandblasted Acidetched (Sa) Surface Versus Sa Surface Modified With Ph Buffering Agent (Soi): Four-month Data From a Split-mouth, Multicentre Randomized Controlled Trial

PURPOSE. To compare implant survival and success rates and implant stability quotient (ISQ) values of early-loaded single implants with sandblasted acid-etched (SA, control group) surface versus implants with SA surface modified with pH buffering agent (SOI, test group). MATERIALS AND METHODS. This study was designed as multicentre, split-mouth, randomized controlled trial to evaluate implant and prosthesis survival rates, complications, and implant stability quotient (ISQ) in any partially edentulous subject requiring at least two single implant-supported crowns. A one-stage implant placement procedure was used, and implants were randomized after implant site preparation. ISQ values were eva-luated for each implant, at baseline and then every week up to 8 weeks after surgery, and finally at definitive crown delivery (12 weeks after implant placement). RESULTS. Overall, 62 patients from 9 centres were enrolled in this study. One patient dropped out from the study at 8 weeks. In the first 12 weeks of observation, 2 implants failed, both in the SA group, the difference not being statistically significant (P = 0.5). No prosthesis failure occurred up to 4 months after fitting. Five complications were expe-rienced, 3 in the SA group and 2 in the SOI group. The difference between groups was not statistically significant (OR = 0.66, 95% CI: 0.11 to 4.07; P = 0.650). Of these complications, loss of stability without rotation was observed in 2 implants from the SOI group and 2 implants from the SA group, all in the third and fourth weeks of measurements. All the implants were submerged and successfully osseointegrated at the twelfth week. The last complication was an SA implant screw loosening, which was resolved chair-side. The baseline mean ISQ values were 76.57 ± 7.54 (95% CI 74.69 to 78.44) in the SA group and 75.92 ± 7.69 (95% CI 73.89 to 77.73) in the SOI group. The mean ISQ values at 12 weeks were 79.17 ± 7.83 (95% CI 77.03 to 81.29) and 78.82 ± 8.80 (95% CI 76.42 to 81.21) in the SA and SOI groups, respectively. Mixed-effects modelling revealed a statistically significant difference between groups over time, with slightly lower ISQ values for the SOI group (-0.65; 95% CI-1.14 to-0.15). Statistically significant differences were also estimated among centres (P <0.001). CONCLUSIONS. Within the limitations of the present preliminary report, it is possible to conclude that both implants can be successfully loaded early