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The paper describes a stretchable, microfabricated power generator that will be attached on the skin and will produce energy based on the movements of the human body. The device was fabricated on a polymeric, elastomeric, poly(dimethylsiloxane) (PDMS) sheet. It consists of a piezoelectric thin film of ZnO sandwiched between two stretchable gold electrodes. An innovative technique was used for the deposition of ZnO thin film on the gold electrode-coated polymeric substrate at low temperatures below 150 °C. This is the first attempt to use a uniform film of ZnO, for energy harvesting. The ZnO film had the thickness at the submicron scale and the surface at the centimeter scale. We demonstrated that under a strain of 8% the voltage output from this power generator was equal to 2 V, the power output was equal to 160 μW and the corresponding power density was 1.27 mW/cm2. This device has great potential for application in power sensors attached on the human body, such as temperature sensors or wearable electrocardiography systems.

This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient’s hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient’s hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon’s susceptible organs and the direct radiation dose to a patient’s hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy.

This study addresses a feasibility evaluation method for the heterogeneous reactive extractive distillation of azeotropic quinary mixtures based on visualization in composition space. A critical composition region, that is, thermodynamically infeasible region for heterogeneous reactive extractive distillation, is determined by the constraint of reaction and phase equilibria. In addition, operating constraints are imposed on the feasibility evaluation in terms of the upper and lower internal reflux boundaries. Using these two kinds of feasibility constraints, we examine how the ethyl and isopropyl acetate reactive distillation systems, which cannot produce pure products because of four minimum-boiling azeotropes, lead to a full conversion and pure product recovery with the introduction of an external entrainer inducing L−L splits. The pure acetate production in a single reactive extractive distillation column is possible because the composition trajectory approaches the desired region in composition space without being blocked by both the critical composition region and the infeasible region confined by the internal reflux boundaries.