DESIGN AND FABRICATION OF AN ELECTRICALLY POWERED MAIZE PLANTER

The correct application of production inputs for environmental and agricultural production sustainability is a key to successful production of maize. An electrically powered maize planter was designed and fabricated. Light reflecting optoelectronic field counter capable of detecting free falling object with equivalent or greater than 0.7 mm distance in planter delivery tube was designed and built to monitor seed drop on the planter. The device accurately counted the falling seeds with the planter forward speed of 1.38 m/s and seed delivery tube of 24 mm. The average number of two seeds was discharged per hole.

Endoscopic filling with polyglycolic acid sheets and fibrin glue of persistent fistula after esophagectomy

Background Treatment of anastomotic leakage in reconstruction after esophagectomy remains challenging. This report presents a new endoscopic filling method for persistent fistula after failure of conservative treatment of leakage caused by anastomotic insufficiency. Methods 10 of 14 patients, in whom post-esophagectomy leakage had failed to resolve after 2 weeks of conservative treatment, underwent endoscopic filling with polyglycolic acid (PGA) sheet and fibrin glue into the anastomotic leakage site, using a delivery tube and endoscopic catheter, respectively. Results Each patient underwent jejunostomy, to secure nutrition. The leakage was resolved in all 10 patients. The mean number of PGA – fibrin glue procedures was 1.7. The mean period from the first application to the resumption of oral intake was 31.6 days, from the final application it was 14.7 days. Conclusions The reported filling method offers a new endoscopic approach for persistent fistula after esophagectomy when conservative treatment of leakage has failed.

Effects of the Delivery Tube Diameter on the Qualities of Cu-9.7Sn-0.2P Alloy Powder Produced by Gas Atomization

Gas atomization is one of the most cost-effective methods for preparing spherical powders. The Cu-9.7Sn-0.2P alloy powder for 3D printing was prepared by a self-developed double nozzle gas atomization technique with different deliver tube diameters, and the particle size and shape of the powder were characterized. Results show that the powder particles are mostly nearly spherical, mixed with a few irregular powders. The average O. Bluntness of the powders are 60~70%, the average Outgrowths are lower than 18%. The deliver tube diameter affects the powder characteristics directly. The increase of the diameter increases the particle size of the powder and reduces the sphericity. At the same time, the adhesion of the satellite powder decreases, the flowability becomes better and the oxygen content drop. The surface and internal structure of the powder are mainly cellular and dendritic structures.

Properties of PTFE tape as a semipermeable membrane in fluorous reactions

In a PTFE tape phase-vanishing reaction (PV-PTFE), a delivery tube sealed with PTFE tape is inserted into a vessel which contains the substrate. The reagent diffuses across the PTFE tape barrier into the reaction vessel. PTFE co-polymer films have been found to exhibit selective permeability towards organic compounds, which was affected by the presence of solvents. In this study, we attempted to establish general trends of permeability of PTFE tape to different compounds and to better describe the process of solvent transport in PV-PTFE bromination reactions. Though PTFE tape has been reported as impermeable to some compounds, such as dimethyl phthalate, solvent adsorption to the tape altered its permeability and allowed diffusion through channels of solvent within the PTFE tape. In this case, the solvent-filled pores of the PTFE tape are chemically more akin to the adsorbed solvent rather than to the PTFE fluorous structure. The solvent uptake effect, which was frequently observed in the course of PV-PTFE reactions, can be related to the surface tension of the solvent and the polarity of the solvent relative to the reagent. The lack of pores in bulk PTFE prevents solvents from altering its permeability and, therefore, bulk PTFE is impermeable to most solvents and reagents. However, bromine, which is soluble in liquid fluorous media, diffused through the bulk PTFE. A better understanding of the PTFE phase barrier will make it possible to further optimize the PV-PTFE reaction design.

Ultrasonic gas alloy atomization under near-zero aspiration pressure

In this paper, ultrasonic gas atomization (USGA) of Zn – Al under near-zero aspiration pressure was discussed. The protrusion length of delivery tube was modified to adjust the aspiration pressure. Under near-zero aspiration pressure, melt filming was observed by camera and more fine powders were produced. While under larger subambient aspiration pressure, melt filming was unavailable, corresponding to less fine powders. The results suggest that the position of the wake near the delivery tube can be optimized under near-zero aspiration. Less protrusion of delivery tube reduces the energy loss in gas flow deflection. Both facilitate to produce finer powders.