Enhanced production from an Air Gap Membrane Distillation Desalination system by varying the feed entry angle

The membrane distillation (MD) process is an evaporative metho driven by the partial pressure difference between two different temperature solutions, namely the hot feed and the coolant. The hot feed evaporates, and the vapour gets condensed to the cooler side. A hydrophobic membrane maintains the evaporating surface. Air Gap Membrane Distillation(AGMD) separates the hot feed from the coolant by a narrow air gap and a coolant plate. The condensate forms on the coolant plate, and the air gap works as an insulation for the heat loss through the membrane. The salient parameters like feed temperature, coolant temperature, and air gap thickness have already been identified through research in previous years. In this study, an innovative technique has been tested to minimize the polarization and increase the production from an AGMD lab-scale unit. The effect of the feed flow entry angle has been investigated. Also, the combined effect of inclined flow entry and a finned coolant surface has been studied. It has been found from the experiments that with a feed flow entry angle of 60°, the system shows an average of 10% to 14% boost in performance. When 60° inlet flow angle and finned coolant plate work in combination, an average of 69% to 78% increase of distillate flux was observed with the same energy input.

Numerical simulation of cavitation characteristics in high speed water entry of head-jetting underwater vehicle

Autonomous underwater vehicle will be subjected to a huge impact load during high speed water entry, which will damage the structure and the internal instruments of the vehicle. Therefore, it is of great significance to study the buffer mechanism of the vehicle during the process of water-entry. In this paper, a kind of head-jetting device with disk cavitation is used. The complex cavitation forms, under the three-phase coupling of gas, liquid and solid, in the water entry process of the vehicle on which the device is installed. In this paper, the numerical simulation of high-speed water entry of the vehicle equipped with head jet device is carried out. Through the analysis of water entry cavitation under typical working conditions, the following conclusions are obtained. After the installation of head jet device, the water entry cavity of the vehicle changes gradually from cone to spindle shape. The air jet, compared with that without jet, can promote the formation of water inlet supercavitation, decrease the interaction area between the vehicle and water, and reduce the impact load during water entry. At the same water entry depth, the diameter of cavitation increases with the amount of air jet. The water entry velocity has a great influence on the difference of cavitation shape. The water entry depth closure phenomenon, when the water entry velocity is less than 100 m/s, can be observed in the depth of 3.5 times of the projectile length. The water entry angle has a significant effect on the cavitation shape. The cavity shows obvious asymmetry when the vehicle slants into the water, and the diameter and length of the bubbles decrease with the increase of the water entry angle. The research content of this paper provides technical support for the engineering practice of high-speed water entry and load reduction, and the conclusions are of great significance in related fields.

Sensitivity of Rodel Roundabout Delay Estimates to Input Parameters

Modern roundabouts are developed to increase the traffic capacity and decrease the traffic delay. They are popular around the world and are becoming common in Canada and the United States. A great design of a roundabout is to achieve the minimum delay. According to the research papers regarding the delay at roundabouts, it is expected the vehicle delay, the stop ratio at various traffic volumes, and the level of saturation of roundabouts are smaller than the amount of similar parameters on un-signalized intersections. The purpose of this thesis is clarification and measurement of the geometric parameters through the RODEL software to depict their influence on the sensitivity of roundabout delay. This study has been done through creation and analysis of numerous tables and graphs for various traffic volumes and peak periods. Furthermore, the required accuracy of each parameter in estimating delay of a planned roundabout is determined. The outcome of this analysis indicates the effects of the geometric parameters on the roundabout delay. While the Half Width, Entry Width, and Flare Length have the greatest influence on the delay, the Entry Radius, Entry Angle (PHI), and Inscribed Circle Diameter have the least influence.

Sensitivity of Rodel Roundabout Delay Estimates to Input Parameters

Modern roundabouts are developed to increase the traffic capacity and decrease the traffic delay. They are popular around the world and are becoming common in Canada and the United States. A great design of a roundabout is to achieve the minimum delay. According to the research papers regarding the delay at roundabouts, it is expected the vehicle delay, the stop ratio at various traffic volumes, and the level of saturation of roundabouts are smaller than the amount of similar parameters on un-signalized intersections. The purpose of this thesis is clarification and measurement of the geometric parameters through the RODEL software to depict their influence on the sensitivity of roundabout delay. This study has been done through creation and analysis of numerous tables and graphs for various traffic volumes and peak periods. Furthermore, the required accuracy of each parameter in estimating delay of a planned roundabout is determined. The outcome of this analysis indicates the effects of the geometric parameters on the roundabout delay. While the Half Width, Entry Width, and Flare Length have the greatest influence on the delay, the Entry Radius, Entry Angle (PHI), and Inscribed Circle Diameter have the least influence.

Strategic management as an enabler of co-creation in public services

The current transformations in society, the economy and the public sector call for the development of more unified theoretical frameworks. This article takes the literature on strategic management as a theoretical entry angle and aims to better understand how the adoption of models of strategic management can enable processes of public value co-creation. Utilising the literature centred on the notion of ‘schools of thought’ in the strategic management of public services, the article discusses how co-creation as a mode of governance in public services can contribute to innovative public service solutions and value co-creation. The Welsh Water’s ‘Water Resilient Community’ ‐ a project characterised by long-term strategic planning as well as by local innovation ‐ is used to illustrate the argument. Four propositions on the drivers/enablers and key managerial issues for undertaking a strategic approach to co-creation as a mode of governance are offered to enhance future practice, research and theory.

Kinematic Analysis of 2-Point and 3-Point Jump Shot of Elite Young Male and Female Basketball Players

Basketball shooting is one of the most important offensive skills in basketball. Winning or losing a game mostly depends on the shooting effectiveness. The study aims to compare the selected kinematic variables of 2-point (2-pt) and 3-point (3-pt) jump shots (after making a cut and receiving the ball) and ascertain the differences between elite male under 16 and 18 (U16M, U18M) and female under 16 and 18 (U16F, U18F) basketball players. Overall, forty-eight young male and female basketball players participated in the study. 3D motion analysis using an inertial suit with the addition of utilizing a smart ball was performed for assessing the 2-pt and 3-pt shooting techniques. Players in male categories shot for 2-pt with a higher center of mass difference in the vertical direction (U16M 5.7 cm, U18M 3.9 cm vs. U16F 1.4 cm, U18F 0.6 cm), with higher release shoulder angle (U16M 110.9, U18M 113.8 vs. U16F 103, U18F 105), and with a higher entry angle of the ball (U16M 34, U18M 32 vs. U16F 30, U18F 30) when compared to female categories (p < 0.001). In the 3-pt shooting, there were differences between male and female categories in the shoulder angle when releasing the ball (p < 0.001). In the players shooting speed, there were differences between U16M vs. U18F (0.95 ± 0.1 vs. 0.88 ± 0.1; p = 0.03) and U16F vs. U18F (0.96 ± 0.06 vs. 0.88 ± 0.1; p = 0.02) players. Male categories shot 3-pt shots with a smaller center of mass difference in the horizontal direction when compared to 2-pt shots (p < 0.001). The entry angle was higher in successful shooting attempts compared to unsuccessful shooting attempts when shooting for 3-pt (p = 0.02). Player shooting speed was higher in all categories (except U18F) when shooting for 3-pt (p < 0.001). It appears that performers show difference in kinematic variables based on distance from the basket. Basketball coaches and players should work to minimize the kinematic differences between 2-pt and 3-pt shooting and to optimize the shooting technique.

Gravity assists maneuver in the problem of extension accessible landing areas on the Venus surface

This study discusses the usage of Venus gravity assist in order to choose and reaching any point on Venusian surface. The launch of a spacecraft to Venus during the launch windows of 2029 to 2031 is considered for this purpose. The constraints for the method are the re-entry angle and the maximum possible overload. The primary basis of the proposed strategy is to use the gravitational field of Venus to transfer the spacecraft to an orbit resonant to the Venusian one – with the aim of expanding accessible landing areas. Results of the current research show that this strategy provides an essential increase in accessible landing areas and, moreover, may provide an access to any point on the surface of Venus with a small increase in ∆V required for launch from the Earth and in the flight duration. The comparison with the landing without using gravity assist near planet is also given.

Mathematical modeling of the technological process of operation and parameters of the device for formation of longitudinal rollers (pawls) between cotton rows

This article reveals the features of mathematical modeling of the technological process of work and the parameters of the device for the formation of longitudinal pawls between cotton rows. And also, the results of the STUDY are presented, and the following main conclusions were made: the task of mechanizing the formation of longitudinal legs can be solved by lifting the soil from the two side furrows and throwing it into the central furrow using a palletizing device with active working organs. Studies have shown that for the qualitative formation of longitudinal dogs between rows of cotton, it is advisable to use a device with a single-pass continuous auger. To avoid damage to cotton seedlings, to ensure the required productivity with minimal energy consumption, the screw device must have the following parameters: the screw diameter is 400 mm, the inner and outer diameters of the screw pipe 420 and 426 mm; respectively, the pitch of the screw is 320 mm; the rotation speed of not less than 325 rpm; and the mounting angle relative to horizontal-not more than 35 °; the entry angle into the ground shield located in front of the screw tube, the device needs to be within 24-25º.

Transfemoral-venous transcatheter access to left ventricle through the created communication of inter-ventricular septum with the assistance of arterio-venous circuit

Background During transcatheter aortic/mitral valve replacement (TA/MVR), current available routes are limited due to unfavorable entry-angle, vessel-anatomy or mini-thoracotomy. Through created communication of inter-ventricular septum (C-IVS), transfemoral venous transcatheter access to left ventricle becomes feasible with the assistance of arterio-venous circuit. Purpose The study was conducted to investigate the feasibility and safety of transfemoral-venous transcatheter access to left ventricle through the created C-IVS in a swine model. Methods Via femoral artery, transcatheter puncture of mid-IVS was performed with the custom-made nickel-titanium needle (0.038-inch, needle-tip bent 60 degrees automatically associated with increased hardness when temperature was above 30°C) and 6F-sheath in 20 healthy Chinese mini-swine. Then femoral arterio-venous circuit was established through created C-IVS with hydrophilic guidewire in all swine, and femoral veno-venous circuit was further created through C-IVS and atrial septum in 4 swine. After pre-dilation of C-IVS, a 20F-sheath was introduced into left ventricle transvenously over the guidewire. Furthermore, transfemoral-venous TAVR was attempted with this approach in one swine. C-IVS was evaluated postoperatively and was further confirmed pathologically 2 months later. Results All transcatheter puncture of IVS was performed successfully in left ventricle and the thickness of mid-IVS was 7.67±0.98 mm. During the puncture, ventricular fibrillation occurred in one swine (successfully defibrillation) and only isolated ventricular premature beats/non-sustained ventricular tachycardia were observed in other swine. In all swine, femoral arterio-venous/veno-venous circuit was established via C-IVS, and the 20F-sheath was introduced into left ventricle safely through femoral vein and C-IVS. With the aid of vessel circuit, the 20F-sheath was further advanced into aorta in 16 swine (the entry-angle was 145.3±12.2 degrees) and into left atrium in 4 swine. After the procedure, there was one swine with moderate tricuspid regurgitation and 5 swine with mild residual shunt (2.6±0.7 mm). In addition, epicardial coronary arteries were normal in all swine. Two months later, residual shunt was still detected in 3 swine and the communication was confirmed pathologically. In other swine, there was no defect of IVS and mild replacement-scar was identified along C-IVS. In the swine underwent transfemoral-venous TAVR, prosthetic valve was deployed successfully with good function. Conclusions With the aid of vessel circuit, transfemoral-venous transcatheter access to left ventricle is feasible and safe via C-IVS, and transfemoral-venous TAVR was achieved successfully using this novel approach with favorable entry-angle. Figure 1 Funding Acknowledgement Type of funding source: Other. Main funding source(s): National Natural Science Foundation of China

A Quantitative Anatomic Study of Plate-Screw Fixation of the Acetabular Posterior Column through a Posterior Approach

Objective The aim of this study was to determine safe paths for screw placement on the posterior column of the acetabulum. Methods A total of 25 male hemipelvises were utilized in this study. These hemipelvises were sectioned, and formed cross-sections A, B, C, D, and E. The length of the screw and screw posterior column angle of the entry points at cross-sections B, C, and D were measured. Results On the margin of the acetabulum, lateral middle 1/4 point, midpoint, medial middle 1/4 point, and medial margin of the posterior column of each cross-section, the safe entry angle of inclination is 39, 57, 74, 90, and 106°, respectively, and the length of the screw is 35.5 mm, 33 mm, 32 mm, 31 mm, and 74 mm, respectively. Conclusion On the lateral 1/4 region, lateral middle 1/4 region, medial middle 1/4 region, and medial 1/4 region of the posterior column, the screw posterior column angle is 40 ~ 60°, 60 ~ 75°, 75 ~ 90°, and 90°~parallel to the quadrilateral plate, respectively, and the length of the screw is 30 mm.