Performance Evaluation of Junctionless FinFET using Spacer Engineering at 15nm gate Length

In this proposed work, performance of junctionless transistor with the use of spacers has been evaluated at 15nm gate length in Cogenda TCAD tool. This work is implemented as variation in four parts: changing the spacer extension length, placement of spacers having dual-κ, proportion of low and high-κ spacers, and value of high-κ dielectric constant. Impact of all these parameters is considered on the output of proposed device in terms of various output parameters like on-current (ION), off-current (IOFF), subthreshold swing (SS), drain induced barrier lowering (DIBL), transconductance (gm), transconductance generation factor (TGF), output conductance (gd), early voltage (Vea) and intrinsic gain (Av). From the simulations, it has been observed that placing spacers of dual-κ along the left and right sides of gate region has improved device performance in terms of output parameters. Due to increased gate capacitances, the increase in dielectric constant value has degraded the device performance for longer spacer extension length. However, for shorter spacer extension length, the device characteristics are improved as the value of dielectric constant is increased. Therefore a trade-off is required to get the optimum results of the device.

Effect of the welding process on microstructure, microhardness and residual stresses of capacitor discharge stud welded joint

Capacitor discharge (CD) stud welding is a common and fast connection technology. This paper presents an experimental and simulation study of the stud weld joint of copper stud and carbon plate. An optimized stud welding process was proposed based on microstructure, microhardness and residual stresses of CD stud welded joint. The results show that a narrow weld seam with widmanstaten structure were formed because of quickly cooling. For the longer stud extension length, the width of weld zone becomes wider and the microstructure becomes more uniform. As the increase of welding voltage and stud extension length, the microhardness increases then decreases. However, the residual stresses are increased with welding voltage increases, while they are decreased with the increases of stud extension length. The optimized welding voltage and stud extension length should be designed to 90 V and 5 mm, respectively. This study will provide a great significance to the stud welding on site.

Experimental study on the flame extension and risk analysis of a diffusion impinging flame in confined compartment

In this work, an experimental investigation on a diffusion impinging flame in a confined compartment was performed. The objective was to study the influence of confinement on the behavior of a flame impinging the ceiling and to deduce the auto-ignition risk of the smoke produced in the confined compartment. For this, configurations with five confinement levels were constructed by the condition of windows and/or door in the compartment and the variation of the heat release rates was made between 0.5 and 18.6 kW. To evaluate the flame morphology and flame extension length, an image processing method based on the direct linear transformation algorithm and the fire segmentation algorithm was adopted. From the experimental data, it was shown that the heat release rate of 4.6 kW presents a critical value for the flame extension in confined configurations, which corresponds to the equivalence ratio of the enclosure greater than 1, highlighting an under-ventilated environment. In addition, an auto-ignition risk analysis of smoke with unburnt gas in the compartment was carried out. The concentration and temperature of these gases were compared to the lower flammability limits and the auto-ignition temperature. It was observed that there was auto-ignition risk of the smoke under the ceiling, especially in the confined compartment of equivalence ratio greater than 1. Under these conditions, it is possible to have a fire spread to another compartment.

Numerical and Experimental Assessment of a Novel Anchored for Intramedullary Telescopic Nails Used in Osteogenesis Imperfecta Fractures

Osteogenesis Imperfecta (IO) is a bone disease mainly characterized by the low bone density that produces common fractures in children around 0–7 years. The use of metal implants is a typical treatment of this disease. The intramedullary telescopic nail (ITN) was inspired by the progressive growth in the long bones such as the femur or humerus during children’s aging. This work shows an experimental assessment of the ITN’s, focusing on their fixation; the proposed improvements in the design of the intramedullary nail studied include the separation of the element into two parts for telescopic enlargement, minimal invasive fixation through the distal anchorage, and the double auto-drilled end for fixation on the distal and proximal section of the bone. The samples were manufactured in 316 L steel and mounted on specialized jaws to replicate the implants’ boundary conditions. The experimental test was repeated three times to report the intramedullary telescopic nail’s behavior at three lengths. The results show that the device supports only 79.06 N when not at extension length. However, if the device is extended 150% it will support 46.87 N which suggests that intramedullary telescopic nails can only increase by 25% of their original length before they fail.

Dynamic Behavior of a Precast and Partial Steel Joint under Various Shear Span-to-Depth Ratios

The dynamic behavior of a PPSRC beam–column joint is related to constraint effect, strength deterioration and strain rate effect. Then, it can be assessed by bearing capacity, stiffness degradation, displacement ductility and energy consumption. The results show that the increased strain rate causes growth in ring stiffness, bearing capacity and energy consumption of PPSRC beam–column joints. However, the influence of shear span-to-depth ratio on dynamic mechanical properties of PPSRC beam–column joints is more obvious than that of strain rate. Regardless of strain rate, the bearing capacity, initial stiffness, ring stiffness and energy consumption of PPSRC beam–column joints decrease as the shear span-to-depth ratio increases. Moreover, the ring stiffness under reverse direction is smaller than that the under forward direction at each displacement level. However, the stiffness degradation under a lower shear span-to-depth ratio is more obvious than that under a higher shear span-to-depth ratio. Moreover, the displacement ductility with a higher shear span-to-depth ratio is better than that with a lower shear span-to-depth ratio. Finally, the mechanical properties of PPSRC beam–column joints are affected by the extension length of partial steel plate, and the reasonable extension length of the partial steel plate in the column is affected by the shear span-to-depth ratio.

Laparoscopic Specimen Extraction in Vitro: Preliminary Experience

Background: The last procedure of the surgeon in laparoscopic surgery is to extract the specimen with the smallest incision. This experiment aimed to explore the maximum diameter of specimens that can be extracted with different adjuvant incision length and shape by in vitro physical experiments.Materials and Methods: We use the abdominal wall with the muscle layer of pigs was fixed on a square wooden frame to simulate the abdominal wall of humans. Then, making specimen extraction port: circular, inverted Y-shaped and straight-line incisions with different sizes and lengths respectively，and making different sizes and species specimens. These specimens are extracted from different incisions by force device. Measure the tension value (N), and record the length or diameter of the smallest auxiliary incision that the largest sample diameter can pass through. This experiment provides us with preliminary experience on how to choose the appropriate specimen extraction auxiliary incision according to the specimen diameter in surgery. Results: The maximum diameters of specimens that can be extracted with circular ostomy diameters of 2.4, 2.7 and 3.3 cm are 4.0, 4.5 and 6.0 cm, respectively. Specimens with diameters of 6.0, 8.0 and 10.0 cm could be extracted with inverted Y-shaped incisions with the length around umbilicus of 1 cm and extension length of 1.0, 3.0, 4.0 cm, respectively. Moreover, these same specimens could be extracted with inverted Y-shaped incisions with the length around umbilicus of 2 cm and extension length of 0.0, 1.0 and 2.0 cm, respectively. In straight-line incisions, tough tissue specimens (made from chicken gizzard) with diameters of 1.0, 2.0, 4.0 and 6.0 cm could be removed from incisions with diameters of 1.0, 2.0, 3.0 and 4.0 cm, respectively. Conclusion: Along with preoperative imaging, surgical planning and trocar position, the shape and length of adjuvant incisions can be used to improve the extraction of specimens via laparoscopy.

Modeling research on the extreme hydraulic extension length of horizontal well: impact of formation properties, drilling bit and cutting parameters

Horizontal well can increase well productivity and improve the economic benefit, which significantly promotes the development of shale gas, tight oil and heavy oil. Moreover, it plays an important role in the development of natural gas hydrate. Horizontal extension ability is one of the key indexes of horizontal well, but it is always impacted by formation properties and well structure. Therefore, a model is established to analyze the impact of formation properties and well structure as comprehensive as possible, which considers not only traditional influencing factors, like formation pressure and drilling bit parameters, but also other key factors, including cutting particle size, wellbore diameter and cross section. Based on the analysis, some advises are proposed for field application. The analysis indicates that horizontal well has stronger extension ability in the formation with low formation pressure and high fracture pressure, but it is still limited by pump pressure. Under-balanced drilling can strength the extension ability in high formation pressure by reducing drilling mud density. The natural fractures in formation should be noted when drilling long horizontal well. The extension length increases and then decreases with the cutting particle size, so cutting particle has optimal size for the horizontal extension length, which can be adjusted by the rate of penetration and rotation speed. The extension length increases first and then decreases with the gap between drilling string and hole. Considering the demand of rock breaking and cutting sweeping around drilling bit, it is not recommended to adjust the drilling bit parameters. Both the cutting bed height and drilling string eccentricity have impact on horizontal extension length by changing minimum cutting-carry pump rate and annular pressure drop. Under different combinations of above two parameters, minimum cutting-carry pump rate and horizontal extension length are determined by different factors and can be divided into three parts, including acceptable cutting bed height, cutting lifting efficiency, pump pressure and total circulation pressure loss and well bottom pressure and formation fracture pressure. The findings of this study can help for better understanding of horizontal well hydraulic extension length and optimization method.

Design and optimisation of magnetically-tunable hybrid piezoelectric-triboelectric energy harvester

The demand for energy harvesting technologies has been increasing over the years that can be attributed to its significance to low power applications. One of the key problems associated with the available vibration-based harvester is the maximum peak power can only be achieved when the device frequency matches the source frequency to generate low usable power. Therefore, in this study, a magnetically-tunable hybrid piezoelectric-triboelectric energy harvester (MT-HPTEH) was designed and optimised. Four key design factors: mass placement, triboelectric surface area, extension length and magnetic stiffness were investigated and optimised. The voltage generation from piezoelectric and triboelectric mechanisms was determined individually to understand the effect of each design factor on the mechanisms. An output power of 659 µW at 180 kΩ at 44 Hz was obtained from the optimised MT-HPTEH with a theoretical–experimental discrepancy of less than 10%. The added magnetically-tunable feature enabled the harvester to work at the desired frequency range with an open circuit voltage between 7.800 and 20.314 V and a frequency range from 38 to 54 Hz. This MT-HPTEH can power at least six wireless sensor networks and can be used for low power applications such as RFID tags. Future work may include designing of energy-saving and sustainable harvester.