Morphological Adaptation for Speed Control of Pipeline Inspection Gauges MC-PIG

Passive and active hybrid pipeline inspection gauges (PIGs) have been used for in-pipe inspection. While a passive PIG cannot control its speed, the hybrid version can achieve this by using an integrated valve specifically designed and embedded in the PIG. This study proposes a generic new method for speed adaptation in PIGs (called MC-PIG) by introducing a generic, modular, controllable, external valve unit add-on for attaching to existing conventional (passive) PIGs with minimal change. The MC-PIG method is based on the principle of morphological computation with closed-loop control. It is achieved by regulating/computing the PIG's morphology (i.e., a modular rotary valve unit add-on) to control bypass flow. Adjustment of the valve angle can affect the flow rate passing through the PIG, resulting in speed regulation ability. We use numerical simulation with computational fluid dynamics (CFD) to investigate and analyze the speed of a simulated PIG with the valve unit adjusted by proportional-integral (PI) control under various in-pipe pressure conditions. Our simulation experiments are performed under different operating conditions in three pipe sizes (16″, 18″, and 22″ in diameter) to manifest the speed adaptation of the PIG with the modular valve unit add-on and PI control. Our results show that the PIG can effectively perform real-time adaptation (i.e., adjusting its valve angle) to maintain the desired speed. The valve design can be adjusted from 5 degrees (closed valve, resulting in high moving speed) to a maximum of 45 degrees (fully open valve, resulting in low moving speed). The speed of the PIG can be regulated from 0.59 m/s to 3.88 m/s in a 16″ pipe at 4.38 m/s (in-pipe fluid velocity), 2500 kPa (operating pressure), and 62 °C (operating temperature). Finally, the MC-PIG method is validated using a 3D-printed prototype in a 6″ pipe. Through the investigation, we observed that two factors influence speed adaptation; the pressure drop coefficient and friction of the PIG and pipeline. In conclusion, the results from the simulation and prototype show close characteristics with an acceptable error.

Spreader Graft Versus Spreader Flap in Rhinoplasty: A Systematic Review and Meta-Analysis of Aesthetic and Functional Outcomes

Background Insufficient support of the nasal mid-vault during rhinoplasty can cause significant complications. Accordingly, surgeons recently pay much more attention to the preservation of nasal patency. The spreader graft is the gold standard technique for the reconstruction of nasal mid-vault. Objectives The objective of this study was to compare the spreader graft and spreader flap in terms of aesthetic and functional outcomes. Methods An inclusive search was performed using PubMed/Medline, Google Scholar, Cochrane Library databases up to April 2021. Multiple aesthetic and functional factors including dorsal aesthetic lines restoration, satisfaction rate, internal nasal valve angle improvement, nasal obstruction symptom evaluation (NOSE) scale, and active anterior rhinomanometry (AAR) were evaluated. Also, a meta-analysis was performed on included articles that provided adequate data for mentioned factors. Results After excluding papers that did not conform with the selection criteria, 10 articles with a total sample size of 567 cases with a mean age of 27.7 (range: 18- 65) were finally included. Analysis of the data revealed no statistically significant difference between the spreader graft and spreader flap techniques in terms of dorsal aesthetic lines restoration, internal nasal valve angle improvement, NOSE scale, and AAR. Conclusions However, in terms of satisfaction rate, the analyzes indicated that spreader graft has significantly superior aesthetic outcomes. Generally, in case of appropriately selected patients, there is no statistically significant difference between spreader graft and spreader flap techniques in terms of aesthetic and functional outcomes.

Numerical study on a rotational hydraulic damper with variable damping coefficient

The rotational hydraulic damper has advantages in the design and control of rotational machines. This paper presents a novel hydraulic rotational damper with the characteristic of adjusting the damping coefficient. It is composed of a shell, a gap, a rotor shaft, sliding vanes, a valve, and a motor, just like a combination of a sliding pump system and a valve driven by a motor. A new cam ring slot designed to guide the radial motion of sliding vanes could reduce friction resistance force, which will also benefit the design of the sliding pump. The damping coefficient model of this damper is established based on dynamic analysis. Series of numerical simulations validate the impact of factors on the damping coefficient. Frictional resistances have little influence on the damping coefficient during most conditions. The total coefficient is positively correlative with the angular velocity and the valve angle. Therefore, changing the valve angle according to the rotor shaft’s angular speed could adjust the damping coefficient.

The Relationship between Lateral Nasal Wall Collapse and Nasal Obstruction, a case-control study

Objectives In clinical practice, lateral nasal wall collapse during forced inspiration is widely regarded as a sign of nasal obstruction or criterion indicating nasal valve surgery. This study aims to evaluate the relationship between the degree of lateral nasal wall collapse and subjective nasal obstruction. Design Case-Control study Setting Tertiary centre hospital Participants Case group consisted of 24 patients who had been diagnosed with a deviated nasal septum or nasal valve stenosis. Control group consisted of 27 volunteers with no nasal obstruction symptoms and no septal deviation on nasal endoscopy. Main outcome measures Lateral nasal wall collapse is determined by the degree of lateral nasal wall triangle (LNWT) area reduction on frontal view during forced inspiration compared to quiet inspiration. LNWT area ratio of the patient and control groups was compared. The relationship between the lateral nasal wall collapse and clinical factors including symptom scores, nasal valve angles, skin thickness were evaluated. Results The average LNWT area ratio of the patient (n=24) and control groups (n=27) was 0.96 and 0.83 respectively (p=0.001). Symptom score (NOSE and VAS) is not related to the degree of lateral nasal wall collapse. Moreover, nasal valve angle and skin thickness were also not related to the degree of lateral nasal wall collapse. In 14 of the 19 patients, the more obstructed side corresponded to the side of narrower nasal valve angle, and 5 were not. Conclusion Lateral nasal wall collapse is not related to a patients’ nasal obstruction.

Significance of Inner Nasal Valve In Septoplasty

Background: Nasal obstruction due to deviated septum is commonly treated with conventional septoplasty. This surgery however is inadequate in cases of compromised nasal valves and leads to persistent symptoms. Hence, we stressed the evaluation of nasal valves before septal surgery & studied the outcome of the patients with valve area correction. Aim: To prove the significance of inner nasal valve in nasal surgery. Objective : To analyse the outcome of Open septoplasty. Methodology:A retrospective review of our patients undergoing Open septoplasty was analysed from April 2016 to January 2021. The preoperative and post operative evaluations were calculated & statistically analysed. Results : A total of 400 patients underwent Open septoplasty. Out of which 392(98%) showed symptomatic improvement in breathing difficulty & 380(95%) were happy with the asthetic improvement. Conclusion: Open septoplasty and Spreader grafts is best solution to improve Internal Nasal valve angle. Rim graft to improve external valve collapse. Spreader graft also gives asthetic & functional improvement

ANALISIS DEBIT AIR DENGAN VARIASI BENTUK OPEN CHANNEL DENGAN PENAMPANG SEGITIGA, PERSEGI, DAN TRAPESIUM PADA SUATU ALIRAN

An open channel is a channel where water flows with free water. In open channels, such as rivers (natural channels), channel parameters are very irregular. Damming the channel is a transition that serves to determine the height of the water surface along the channel, on this issue the author examines how water flows when through open channel with v-notch, rectangular and trapezoidal shapes in a stream. Based on the test results on 35° valve angle variations, the increase debit from the v-notch debit leads to a rectangular-notch debit of 23.63% and the largest decrease in debit from the rectangular notch to trapezodial-notch is 48.38%. In the valve angle variation 40°, the largest increase in debit between the v-notch discharge towards a rectangular-notch discharge of 18.64% and the decrease in the largest debit from rectangular-notch to trapezodial-notch at 45.31%. In the valve angle variation 45° the largest increase debit between the v-notch debit towards a rectangular-notch debit is 18.64% and the largest decrease debit from the rectangular notch to trapezodial-notch debit is 46.15%.

Experiment and Analysis Briquette Cob Upon Which Burn Producer of Vapour

In Indonesia Corn is one of the second type of food crop, this condition based on physical characteristics andcorn chemical has potential as a source of biomass energy. Corncob biomass waste can be made into corncobbriquettes to produce environmentally friendly alternative energy, where the utilization of biomass as energy isdone by combustion in the combustion chamber, which in this case is stoker. The purpose of this research is toknow the characteristics and efficiency of burning corncobs and corncob briquettes as steam-producing biomassfuels. The experimental method was experiment with combustion of corncob briquettes with 10%, 20%, 30%adhesive variation on stocker combustion chamber using air supply 0,00144 m3/ s, air excess 10% (0,00158 m3/s), and excess Air 20% (0,00173 m3/s) with valve angle 15º, 17º, 18º, and feeding fuel 0,1 kg, 0,15 k, 0,2 kg, fuelis put into continuous combustion chamber using conveyor. The calorific value of 10% tuna corncob briquettesHHV= 8578,38 kJ/kg, LHV= 5338.38 kJ/kg, 20% adhesive HHV= 6127,41 kJ/kg, LHV= 2887,43 kJ/kg, adhesive30% HHV= 6127,41 kJ/kg, LHV: 2887,43 kJ/kg using a calorimeter boom analysis. Temperature generated onburning 10cm tuna corncob briquettes reach 906 ºC and at the lowest temperature of 284 ºC, 20% adhesivereaches 901 ºC and at the lowest temperature of 225 ºC, 30% adhesives reach 829 oC and at the lowesttemperature of 250 ºC. Efficiency of combustion chamber of briquettes 10% cobber cornet briquettes are η: 69%,adhesive 20% η = 66%, adhesive 30% η = 67%. From the results of this type of corn tuna briquette fuel withadhesive variation, fuel on 10% adhesive produces the highest temperature and efficiency