Feasibility studies of intraocular use of gelatin methacryloyl hydrogel to patch retinal tears

2021 ◽  
Author(s):  
Juan Chen ◽  
Chunyi Wang ◽  
Wen Wen ◽  
Jie Ni ◽  
Jingjie Jiang ◽  
...  
Keyword(s):  
Feasibility Studies ◽  
Retinal Tears

Dependence of Current Harmonics of Greenhouse Irradiators on Supply Voltage

2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva
Keyword(s):  
Mathematical Models ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Feasibility Studies ◽  
Power Losses ◽  
Voltage Level ◽  
Supply Networks ◽  
Current Harmonics ◽  
Cable Lines ◽  
Harmonic Composition

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.

Integration of Ecological and Engineering Aspects in Planning Large Scale Tidal Power Development in the Bay of Fundy, Canada

1984 ◽  
Vol 16 (1-2) ◽  
pp. 281-295 ◽  
Author(s):  
Donald C Gordon
Keyword(s):  
Large Scale ◽  
Feasibility Studies ◽  
Bay Of Fundy ◽  
Final Decision ◽  
Power Development ◽  
Tidal Power ◽  
History Of ◽  
Scientists And Engineers ◽  
The Many ◽  
University Scientists

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.

Dilution studies on three marine outfalls in South Africa

1995 ◽  
Vol 32 (2) ◽  
pp. 297-304
Author(s):  
Willem A. M. Botes ◽  
J. F. Kapp
Keyword(s):  
South Africa ◽  
South African ◽  
Field Data ◽  
Prediction Models ◽  
Feasibility Studies ◽  
The South ◽  
Average Current ◽  
Predicted Values ◽  
Prediction Techniques ◽  
Domestic Effluent

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.

Internal limiting membrane graft as a treatment for the retinal detachment secondary to an optic disc coloboma

2021 ◽  
pp. 112067212199268
Author(s):  
Jorge Fernández-Engroba ◽  
Muhsen Saman ◽  
Jeroni Nadal
Keyword(s):  
Visual Acuity ◽  
Retinal Detachment ◽  
Optic Disc ◽  
Subretinal Fluid ◽  
Visual Outcome ◽  
Internal Limiting Membrane ◽  
Subretinal Space ◽  
Direct Closure ◽  
Retinal Tears ◽  
Optic Disc Coloboma

Purpose: To report our anatomical outcome with the internal limiting membrane (ILM) graft procedure in the management of rhegmatogenous retinal detachment (RRD) secondary to optic disc coloboma (ODC). Methods: Description of a new surgical procedure in one eye of one patient who underwent pars plana vitrectomy (PPV) combined with ILM graft technique. Subsequent follow-up included optical coherence tomography (OCT) and visual acuity. Results: After only 1 week, the OCT revealed the ILM graft plugging the retinal tear with complete resorption of subretinal fluid. The sealing effect of this graft persisted after 6 months. However, visual outcome was poor and corrected distance visual acuity was 20/200 as a result of the previous long-standing retinal detachment with loss of photoreceptors. Conclusion: We suggest that ILM graft could be performed as a first line treatment in the management of RRD secondary to ODC. This direct closure of the retinal tears, allows a quick and effective interruption of the communication between the subretinal space and the vitreous cavity. Detecting these retinal tears and applying this technique as soon as possible could achieve not only an earlier anatomical success but obtain good visual results in retinal tears with RRD secondary to ODC. Further studies will be necessary to provide more evidences

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