Artículos de publicaciones periódicas

Permanent URI for this collection

http://ri.itba.edu.ar/handle/123456789/43

Browse

Now showing 1 - 5 of 5

Analytical models integrated with satellite images for optimized pest management
(2016) Bright, L. Zack; Handley, Michael; Chien, Isabel; Curi, Sebastián; Anders Brownworth, L.; D'hers, Sebastián; Bernier, Ulrich R.; Gurman, Pablo; Elman, Noel M.
"The global field protection (GFP) was developed to protect and optimize pest management resources integrating satellite images for precise field demarcation with physical models of controlled release devices of pesticides to protect large fields. The GFP was implemented using a graphical user interface to aid the end-user to select location and define an arbitrary perimeter for protection. The system provides coordinates of drop points for the controlled release devices which can be delivered using drone technology, e.g. unmanned air vehicles. In this work, we present the first proof of concept of this technology. A vast number of pest management applications can benefit from this work, including prevention against vector-borne diseases as well as protection of large agriculture fields."
A combined experimental-computational approach for spatial protection efficacy assessment of controlled release devices against mosquitoes (Anopheles)
(2018-03) Bernier, Ulrich R.; Kline, Daniel L.; Abad Vázquez, Agustín; Perry, Melynda; Cohnstaedt, Lee W.; Gurman, Pablo; D'hers, Sebastián; Elman, Noel M.
"This work describes the use of entomological studies combined with in silico models (computer simulations derived from numerical models) to assess the efficacy of a novel device for controlled release of spatial repellents. Controlled Release Devices (CRDs) were tested with different concentrations of metofluthrin and tested against An. quadrimaculatus mosquitoes using arm-in cage, semi-field, and outdoor studies. Arm-in-cage trials showed an approximate mean values for mosquito knockdown of 40% and mosquito bite reduction of 80% for the optimal metofluthrin formulation for a 15-minute trial. Semi-field outdoor studies showed a mean mortality of a 50% for 24 hour trial and 75% for a 48 hour trial for optimal concentrations. Outdoors studies showed an approximate mean mortality rate of 50% for a 24 hour trial for optimal concentrations. Numerical simulations based on Computational Fluid Dynamics (CFD) were performed in order to obtain spatial concentration profiles for 24 hour and 48 hour periods. Experimental results were correlated with simulation results in order to obtain a functional model that linked mosquito mortality with the estimated spatial concentration for a given period of time. Such correlation provides a powerful insight in predicting the effectiveness of the CRDs as a vector-control tool. While CRDs represent an alternative to current spatial repellent delivery methods, such as coils, candles, electric repellents, and passive emanators based on impregnated strips, the presented method can be applied to any spatial vector control treatment by correlating entomological endpoints, i.e. mortality, with in-silico simulations to predict overall efficacy. The presented work therefore presents a new methodology for improving design, development and deployment of vector-control tools to reduce transmission of vector-borne diseases, including malaria and dengue."
Controlled release spatial repellent devices (CRDs) as novel tools against malaria transmission: a semi‑field study in Macha, Zambia
(2018-11) Stevenson, Jennifer C.; Simubali, Limonty; Mudenda, Twig; Cardol, Esther; Bernier, Ulrich R.; Abad Vázquez, Agustín; Thuma, Philip E.; Norris, Douglas E.; Perry, Melynda; Kline, Daniel L.; Cohnstaedt, Lee W.; Gurman, Pablo; D'hers, Sebastián; Elman, Noel M.
"The emergence of mosquitoes that can avoid indoor-deployed interventions, such as treated bed nets and indoor residual spraying, threatens the mainstay of malaria control in Zambia. Furthermore, the requirement for high coverage of these tools poses operational challenges. Spatial repellents are being assessed to supplement these vector control tools, but limitations exist in the residual effect of the repellent and the need for external power or heat for diffusion of the volatiles."
Planar nozzles for controllable microthrusters
(2017) Pedreira, Patricio; Lauretta, Juan Ricardo; D'hers, Sebastián
"Orbital maneuvering of microsatellite and nanosatellite requirements can be efficiently addressed by planar nozzles, in which realtime thrust control is gained actuating on the nozzle throat area. In the present work, the method of characteristics is used to design a hypersonic contour; then, the resulting profile is laser cut, assembled, and built into a propulsion system to finally perform tests in a vacuum chamber under several working conditions. Results are used to validate the profile and modeling assumptions and investigate overall behavior. Tests showed that thrust-inlet pressure ratio is a linear function of separation between nozzle contours and that no additional losses are introduced in the system. The corresponding design/manufacture/assembly tools can be used to a provide low-cost/low-weight controllable propulsion systems to the small-satellite industry with no efficiency loss."
Rapid reconstitution packages (RRPs) for stable storage and delivery of glucagon
(2019-06) D'hers, Sebastián; Abad Vázquez, Agustín; Gurman, Pablo; Elman, Noel M.
"Current emergency injectors of glucagon require manual reconstitution, which involves several steps that may lead to dosage errors. Rapid reconstitution packages (RRPs) are new devices, designed using computational fluid dynamics (CFD) to optimize fluid mixing, integrating physical properties of active pharmaceutical ingredients (APIs), excipients and diluents. RRPs improve drug stability for long-term storage and ease of delivery. Device prototypes were manufactured using advanced stereolithography apparatus (SLA) 3D printing technology. Reconstitution of glucagon with RRPs was evaluated by highperformance liquid chromatography (HPLC) and optical spectroscopy methods. Enzyme-linked immunosorbent assays were performed to test in vitro activity. Experimental results showed that RRPs effectively reconstituted glucagon even after exposure to 60 °C for a 24-h period. RRPs exhibited improved performance at maintaining drug stability compared to lyophilized glucagon stored in a standard glass vial under the same temperature conditions. RRPs represent a portable platform for rapid reconstitution of lyophilized drugs, compatible with standard syringes available in any clinical setting. The RRP provides an alternative to manual reconstitution process, especially designed for medical emergencies."

Browse

Browsing Artículos de publicaciones periódicas by Author "D'hers, Sebastián"

Results Per Page

Sort Options