scholarly journals Distinctive aspects of consent in pilot and feasibility studies

Author(s):  
Julius Sim
Keyword(s):  
2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva

The article describes the results of the study concerning the effect of the voltage level on current harmonic composition in greenhouses irradiators. It is found that its change affects the level of current harmonics of all types of the studied greenhouse irradiators. With decrease of nominal supply voltage by 10 %, the total harmonic distortion THDi decreases by 9 % for emitters equipped with high pressure sodium lamps (HPSL), by 10 % for emitters with electrode-less lamps and by 3 % for LED based emitters. With increase of nominal supply voltage by 10 %, THDi increases by 23 % for lighting devices equipped with HPSL, by 10 % for irradiators with electrode-less lamps and by 3 % for LED based emitters. Therefore, changes of supply voltage cause the least effect on the level of current harmonics of LED based emitters and then the emitters with electrode-less lamps. Change of the level of supply voltage causes the greatest effect on the level of current harmonics of HPSL based irradiators. Mathematical models of dependence of THDi on the level of supply voltage for greenhouse emitters equipped with LED, electrode-less lamps and HPSL lamps were formulated. These mathematical models may be used for calculations of total current when selecting transformers and supply cable lines for greenhouse lighting devices, for design of new or reconstruction of existing irradiation systems of greenhouse facilities, and for calculation of power losses in power supply networks of greenhouse facilities during feasibility studies for energy saving and energy efficiency increasing projects.


1984 ◽  
Vol 16 (1-2) ◽  
pp. 281-295 ◽  
Author(s):  
Donald C Gordon

Large-scale tidal power development in the Bay of Fundy has been given serious consideration for over 60 years. There has been a long history of productive interaction between environmental scientists and engineers durinn the many feasibility studies undertaken. Up until recently, tidal power proposals were dropped on economic grounds. However, large-scale development in the upper reaches of the Bay of Fundy now appears to be economically viable and a pre-commitment design program is highly likely in the near future. A large number of basic scientific research studies have been and are being conducted by government and university scientists. Likely environmental impacts have been examined by scientists and engineers together in a preliminary fashion on several occasions. A full environmental assessment will be conducted before a final decision is made and the results will definately influence the outcome.


1995 ◽  
Vol 32 (2) ◽  
pp. 297-304
Author(s):  
Willem A. M. Botes ◽  
J. F. Kapp

Field dilution studies were conducted on three “deep” water marine outfalls located along the South African coast to establish the comparibility of actual achievable initial dilutions against the theoretical predicted values and, where appropriate, to make recommendations regarding the applicability of the different prediction techniques in the design of future outfalls. The physical processes along the 3000 km long coastline of South Africa are diverse, ranging from dynamic sub-tropical waters on the east coast to cold, stratified stagnant conditions on the west coast. Fourteen existing offshore marine outfalls serve medium to large industries and various local authorities (domestic effluent). For this investigation three outfalls were selected to represent the range of outfall types as well as the diversity of the physical conditions of the South African coastline. The predicted dilutions, using various approaches, compared well with the measured dilutions. It was found that the application of more “simple” prediction techniques (using average current velocities and ambient densities) may be more practical, ensuring a conservative approach, in pre-feasibility studies, compared to the more detailed prediction models, which uses accurate field data (stratification and current profiles), when extensive field data is not readily available.


Author(s):  
Sharan Deepak Menon ◽  
Koushik Sampath ◽  
Saravanan Sujit Kaarthik

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Katarina Åsberg ◽  
Marcus Bendtsen

Abstract Background Evidence suggests that unhealthy lifestyle behaviours are modifiable risk factors for postoperative complications. Digital behaviour change interventions (DBCIs), for instance text messaging programs and smartphone apps, have shown promise in achieving lifestyle behaviour change in a wide range of clinical populations, and it may therefore be possible to reduce postoperative complications by supporting behaviour change perioperatively using digital interventions. This scoping review was conducted in order to identify existing research done in the area of perioperative DBCIs for reducing alcohol consumption, improving dietary intake, increasing physical activity and smoking cessation. Main text This scoping review included eleven studies covering a range of surgeries: bariatric, orthopaedic, cancer, transplantation and elective surgery. The studies were both randomised controlled trials and feasibility studies and investigated a diverse set of interventions: one game, three smartphone apps, one web-based program and five text message interventions. Feasibility studies reported user acceptability and satisfaction with the behaviour change support. Engagement data showed participation rates ranged from 40 to 90%, with more participants being actively engaged early in the intervention period. In conclusion, the only full-scale randomised controlled trial (RCT), text messaging ahead of bariatric surgery did not reveal any benefits with respect to adherence to preoperative exercise advice when compared to a control group. Two of the pilot studies, one text message intervention, one game, indicated change in a positive direction with respect to alcohol and tobacco outcomes, but between group comparisons were not done due to small sample sizes. The third pilot-study, a smartphone app, found between group changes for physical activity and alcohol, but not with respect to smoking cessation outcomes. Conclusion This review found high participant satisfaction, but shows recruitment and timing-delivery issues, as well as low retention to interventions post-surgery. Small sample sizes and the use of a variety of feasibility outcome measures prevent the synthesis of results and makes generalisation difficult. Future research should focus on defining standardised outcome measures, enhancing patient engagement and improving adherence to behaviour change prior to scheduled surgery.


Sign in / Sign up

Export Citation Format

Share Document