G-Force Test Stand for the Evaluation of Weapon Component Strength

This paper discusses the design of a G-force test stand intended to examine of the effects of mechanical loads present during firing of a weapon and applied to the electronic components contained in the 155 mm calibre guided projectile. The G-force test stand is used to develop and test the effects of using high mechanical loads by decelerating a test specimen through the use of a purpose-designed fender assembly. For the purpose of testing, it is irrelevant whether a load is developed by acceleration or deceleration of the test specimen, as a test result obtained by the deceleration of a test specimen is equivalent to a test result obtained by the acceleration of a test specimen, as used in a 155 mm calibre artillery guided projectile. The G-force test stand was used to test and determine the velocities developed by the test specimens and the G-forces applied to them. The maximum velocity to which a test specimen was accelerated was approx. 72 m/s. The test stand was able to propel the test specimens to velocities an order of magnitude higher than the velocities obtained with a Kast and Masset ram. The tests were performed with rubber and copper fender assemblies. The effect of the specific fender used was demonstrated on the trend of the generated G-force. The test stand could develop G-forces in excess of 10,000 with a duration of more than 500 µs.

Application of Self-Adhesive Soft Silicone Common Foam Dressing in Reducing Intraoperative Pressure Ulcers in Elderly ICU Patients

Pressure ulcer (PU), also called pressure injury, is localized damage to the skin and underlying soft tissues, usually over bony prominences, as a result of sustained mechanical loads applied to the tissues. However, in many situations, complete off-loading of sacral PUs is not possible. Minimising the exposure of wounds and their surroundings to elevated mechanical loads is crucial for healing. We for the first time reported the application of Meipicang in the prevention and treatment of intraoperative pressure ulcers in elderly ICU patients with severe illness. We found that the pressure ulcer risk score ( 20.15 ± 2.17 ) in the dressing group after intervention was higher than that ( 17.42 ± 3.62 ) in the regular group. The incidence of pressure sores in the dressing group was 3.77% lower than the 18.88% in the regular group. The psychological concern score ( 31.41 ± 3.15 ) of the dressing group was higher than that ( 26.92 ± 3.43 ) of the regular group. The trust score ( 29.57 ± 2.61 ) of the dressing group was higher than the score ( 24.28 ± 2.29 ) of the regular group. The score of physiological problems in the dressing group ( 34.69 ± 3.82 ) is higher than that in the regular group ( 29.88 ± 3.54 ). The skin complication rate of the dressing group was 5.56% lower than that of the regular group (22.64%). The comfort score (92.46 ± 4.15) of the dressing group was higher than that ( 80.59 ± 5.43 ) of the regular group. The nursing satisfaction score ( 94.53 ± 3.72 ) of the dressing group was higher than that ( 81.79 ± 4.61 ) of the regular group. To conclude, in this study, we found that the Meipicang dressing can reduce the incidence of pressure ulcers in ICU patients with severe ICU and improve the comfort and nursing satisfaction of elderly ICU patients with severe ICU, which is worthy of promotion.

Experimental Investigation of Performance Characteristics for Savonius-Style VAWTs: A Comparative Study

Savonius-style wind turbines are mainly gauged by two types of coefficients namely: (i) coefficient of power (CP) and (ii) coefficient of torques (CT). Coefficient of power is defined as the ratio of power generated by the turbine to the total power available to the turbine from the free-flowing wind. This is synonymous to the operational efficiency of the wind turbine. Coefficient of torque reflects the torque generating ability of the turbine. In this manuscript, experiments have been performed using three different types of rotor profiles for Savonius-style wind turbines (SSWTs) namely, classical SSWT, Benesh type SSWT and elliptical shaped SSWT using oriented jets. Using deflector plates the orientation of jets have been varied from 20° to 70°. Addition of deflector plates to the wind turbines, assists in maximizing the utilization of wind energy. Experiments have been performed in the laminar air flow. Mechanical loads have been used to study Coefficient of performance (CP) and coefficient of torque (CT) as a function of tip speed ratio (TSRs). The velocity of the wind is adjusted by varying the rheostat that controls the AC motor for the wind tunnel systems. Experimental results indicated that optimum performance could be achieved from all three types of SSWT variants at TSR ∼ 0.70. Out of the three designs studied in this manuscript, elliptic shaped SWT yielded best coefficient of performance equal to 0.39 at TSR = 0.70.