Design, construction and performance study of a cascade impactor for reducing diesel particulate emission

2009 ◽  
Vol 39 (0) ◽  
Author(s):  
Md Shamim Akhter ◽  
SM Najmul Hoque ◽  
Md Nurun Nabi
1970 ◽  
Vol 39 (1) ◽  
pp. 26-29
Author(s):  
Md Shamim Akhter ◽  
SM Najmul Hoque ◽  
Md Nurun Nabi

In this paper, the design and construction of a cascade impactor for reducing particulate emission from a diesel engine exhaust has been presented and experiments have been carried out to determine its collection efficiency. The cascade impactor designed in this work consists of four stages having successive decreasing nozzle diameter so as to capture successive smaller diameter particles in the stages. The successive nozzle diameters (D) were selected 2.1cm, 1.7cm, 1.3cm and 0.9cm. Also the distances between nozzle and impaction plate (S) were taken as 2.1cm, 1.4cm, 0.9cm and 0.45cm respectively so that S/D for succeeding stages becomes 1, 0.82, 0.7 and 0.5 respectively. In this investigation, collection efficiency of the cascade impactor based on different engine operating conditions has been determined. Effect of fitting the cascade impactor to engine exhaust on different engine parameters and engine emissions were also found out. At a constant speed of 1000 rpm, a maximum collection efficiency of about 85% of the impactor was obtained at a load of 6kg. A slight decrease in brake thermal efficiency of the engine with the cascade impactor was also noticed. However, by fitting the cascade impactor to the engine, CO and NOx emissions were found to decrease. Keywords: Real impactor, cascade impactor, Reynolds number, Stokes number, collection efficiency. doi:10.3329/jme.v39i1.1830 Journal of Mechanical Engineering, vol. ME39, No. 1, June 2008 26-29


2014 ◽  
Vol 45 (3) ◽  
pp. 239-245 ◽  
Author(s):  
Robert J. Calin-Jageman ◽  
Tracy L. Caldwell

A recent series of experiments suggests that fostering superstitions can substantially improve performance on a variety of motor and cognitive tasks ( Damisch, Stoberock, & Mussweiler, 2010 ). We conducted two high-powered and precise replications of one of these experiments, examining if telling participants they had a lucky golf ball could improve their performance on a 10-shot golf task relative to controls. We found that the effect of superstition on performance is elusive: Participants told they had a lucky ball performed almost identically to controls. Our failure to replicate the target study was not due to lack of impact, lack of statistical power, differences in task difficulty, nor differences in participant belief in luck. A meta-analysis indicates significant heterogeneity in the effect of superstition on performance. This could be due to an unknown moderator, but no effect was observed among the studies with the strongest research designs (e.g., high power, a priori sampling plan).


Author(s):  
Jyoti Baijal

Examination stress is a ubiquitous phenomenon that has, in the present times, adversely affected the learning outcomes and performance of the students at all levels- primary, secondary or higher education. It’s increasing intensity specifically among students appearing for high stakes board examination evokes a response from the teaching fraternity at the earliest. The reason being that a prolonged experience of stress with respect to evaluative situations is bound to prove detrimental to the mental, physical and emotional well-being of the students. For the nation to develop and progress towards a knowledge society, it is imperative that the students are taught to cope with stressful stimuli and improve performance. Study-Skills Training is an intervention intended to improve their study and test- taking habits and skills. It is based on a cognitive-deficit model which is directed towards improving a variety of cognitive activities that affect the organization, processing and retrieval of information and thereby help in reducing the experience of examination stress. Systematic desensitization as a process can be used to unlearn anxiety reactions by replacing the anxiety response with a calm, relaxed state. Thus, a combination of study-skills training and systematic desensitization has been shown to be effective and superior in alleviating test anxiety


2020 ◽  
Vol 15 ◽  
pp. 155892502097575
Author(s):  
Huiling Wang ◽  
Bin Zhou

Facial masks are beauty products which composed of a facial mask paper and beauty solution. Silk contains the amino acid structure closest to the human skin, and has the skin-friendly, cosmetic and antibacterial functions, but the common method for making nonwoven facial mask paper is not suitable for silk. In this paper, the silkworm’s spinning path is intervened manually to obtain a smart silk facial mask paper (SMC) of controllable thickness, so that the sericin on the silk fiber is well preserved. In the experiment where the SMC is compared with the nonwoven 384-cuprammonium rayon facial mask paper (CRMC) which is the most widely used in the market, it is found that the ways of forming the two facial mask paper are completely different, and therefore the morphologies under SEM are obviously different. The thickness of the SMC is 0.183 mm and the areal weight of it is 38.0 g/m2. It is very close to the CRMC (0.187 mm, 38.4 g/m2). The porosity of the SMC is 84.0%, which is slightly lower than that of the CRMC (86.3%), but its pores are well distributed. Compared with the CRMC, the smart SMC has higher dry and wet strength, lower elongation, slightly lower air permeability and liquid entrainment rate, and better antibacterial performance.


Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 415
Author(s):  
Dayong Ning ◽  
Zihao Li ◽  
Gangda Liang ◽  
Qibo Wang ◽  
Weifeng Zou ◽  
...  

Considering the further exploration of the ocean, the requirements for deep-sea operation equipment have increased. Many problems existing in the widely used deep-sea hydraulic system have become increasingly prominent. Compared with the traditional deep-sea hydraulic system, actuators using a paraffin phase change material (PCM) have incomparable advantages, including lightweight structure, low energy consumption, high adaptability to the deep sea, and good biocompatibility. Thus, a deep-sea drive microunit (DDM) based on paraffin PCM is proposed in this paper. The device adopts a flexible shell, adapting to the high-pressure environment of the deep-sea based on the principle of pressure compensation. The device realizes the output of displacement and force through the electrothermal drive, which can be used as actuator or power source of other underwater operation equipment. The microunit successfully completes the functional verification experiments in air, shallow water, and hydrostatic pressure of 110 MPa. In accordance with experimental results, a reasonable control curve is fitted, highlighting its potential application in deep-sea micro electro mechanical systems, especially in underwater soft robot.


2021 ◽  
Vol 41 ◽  
pp. 102031
Author(s):  
Mohammad Arif Budiman Pauzan ◽  
Mohd Hafiz Dzarfan Othman ◽  
Nurul Jannah Ismail ◽  
Mohd Hafiz Puteh ◽  
Ahmad Fauzi Ismail ◽  
...  

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