Design, construction and testing of a floating hood biodigester prototype for municipal waste organic waste

This paper documented the design, construction and operation test of a floating hood biodigester prototype, using organic residues (ruminal content, blood, bovine excreta and viscera) from the municipal trail of Ciudad Valles, S.L.P., with the purpose of generating biogas. The components of the biodigester system considered were: loading duct, concrete biodigester tank, biogas pipeline, floating hood, gas reservoir, discharge duct and discharge tank. A biodigester with storage capacity in the 0.178 m3 floating hood was designed for a 30-day trial operation and storage of 0.120 m3 of organic waste mixture in the biodigester tank. As of day 17 of operation the daily average of biogas generated was 0.1801 m3. The composition of the biogas at day 30 of operation, showed a content of 59.4% of CH4. When performing the flame test, an intense blue coloration was obtained, which indicates that the biogas produced has a high calorific value that will allow heating and flammability.

Experimental Study of Cyclic Synchronous Vibration of an Integrally Geared Centrifugal Compressor for Air Separation Application

This paper presents an experimental study of high cyclic synchronous vibration observed on the top pinion of an integrally geared centrifugal compressor. This cyclic synchronous vibration was different from the previously reported Morton effect. In a typical cycle, the vibration began with a long quiet period, then took off and followed by settle-down. Sometimes, vibration peaked above a shutdown limit, which subsequently tripped the compressor and then the air separation plant. Frequency spectra showed this new cyclic vibration was dominated by synchronous vibration. To obtain reliable and meaningful phase information for the diagnosis, a new signal processing technique was developed to analyze the historic vibration data captured without a key phasor. An experimental study of this new rotordynamic phenomenon was conducted on the machine in operation. Test data showed the high cyclic synchronous vibration was closely related to Morton effect though it does not have a significant phase shift. An effective remedy measure was therefore taken, and the cyclic synchronous vibration was eliminated. Since then, this compressor has been running smoothly for 17 months. A possible mechanism of the cyclic vibration is discussed in this paper.

Santripreneur Penghasil Kerajinan dari Limbah Plastik di Kawasan Pondok Pesantren KH. Murodi Mranggen Demak

The amount of plastic waste around the Mranggen Market and Pondok Pesantren K.H. Murodi Mranggen Demak is a cause for concern. Good waste management so that plastic waste has use value and is beneficial for the environment around Islamic boarding schools is the goal in this service. The methods used are: problem mapping, design, manufacture, operation test, operation assistance and marketing training for production products. The strategy used to make plastic waste valuable is by conducting training in making variations of plastic waste product crafts with Eco-Bricks made into chairs, flower vases, bags, wallets, prayer mats and others. In addition, it is to strengthen good waste management among students. The results of this santripreneur activity are 1) Santri feel excited to understand and do entrepreneurship/studentpreneurs from an early age; 2) students understand the importance of processing waste and the importance of providing added value to products made from plastic waste, 3) 80 percent of students are able to make variations of crafts from plastic waste and 20 percent still need further assistance, 4) marketing is carried out in collaboration with MSMEs in Indonesia. Semarang and Demak so that it can make passive income for students.

Virtual versus Jaw Simulation in Oral Implant Education: A Randomized Controlled Trial

Background: This research aims to investigate the evaluation methods of teaching oral implant clinical courses and estimate the effectiveness of a virtual simulation platform.Methods: Eighty second- and third-year undergraduates in Lanzhou University were recruited and randomized to either three experimental groups or one control group. The subjects undertook theoretical examinations to test their basic level of knowledge after training in similarly unified knowledge courses. Each student group then participated in an eight-hour operating training session. An operation test on pig mandible was conducted, followed by a second theoretical examination. The assessment consists of three distinct parts: a subjective operating score by a clinical senior teacher, an implant accuracy analysis in cone-beam computed tomography (angular, apical, and entrance deviation), and comparison of the two theoretical examinations. Finally, students completed a questionnaire gauging their understanding of the virtual simulation.Results: There was no significant difference between the four groups in first theoretical examination (P > 0.05); the second theoretical scores of the V-J and J-V group (62.90 ± 3.70, 60.05 ± 2.73) were significantly higher than the first time (57.05 ± 3.92, P < 0.05), while no difference between the V (57.10 ± 3.66) and J (56.89 ± 2.67) groups was found. Thus, the combination of V-J was effective in improving students’ theoretical scores. The V-J and J-V groups had higher scores on operation (73.98 ± 4.58; 71.85 ± 4.67) and showed better implant precision.Conclusion: Virtual simulation education, especially with a jaw simulation model, could improve students’ implantology achievements and training. Currently study found that the V-J group may performed better than the J-V group in oral implant teaching.

Virtual versus Jaw Simulation in Oral Implant Education: A Randomized Controlled Trial

Aim We investigate the evaluation methods of teaching oral implant clinical courses and estimate the effectiveness of a virtual simulation platform. Methods Eighty second- and third-year undergraduates in Lanzhou University were recruited and randomized to either three experimental groups or one control group. The subjects undertook theoretical examinations to test their basic level of knowledge after training in similarly unified knowledge courses. Each student group then participated in an eight-hour operating training session. An operation test on pig mandible was conducted, followed by a second theoretical examination. The assessment consists of three distinct parts: a subjective operating score by a clinical senior teacher, an implant accuracy analysis in cone-beam computed tomography (angular, apical, and entrance deviation), and comparison of the two theoretical examinations. Finally, students completed a questionnaire gauging their understanding of the virtual simulation. Results There was no significant difference between the four groups in first theoretical examination (P>0.05); the second theoretical scores of the V-J and J-V group (62.90±3.70, 60.05±2.73) were significantly higher than the first time (57.05±3.92, P < 0.05), while no difference between the V(57.10±3.66) and J (56.89±2.67) groups was found. Thus, the combination of V-J was effective in improving students’ theoretical scores. The V-J and J-V groups had higher scores on operation (73.98±4.58; 71.85±4.67) and showed better implant precision.Conclusion Virtual simulation education, especially with a jaw simulation model, could improve students’ implantology achievements and training. We found that the V-J group performed better than the J-V group in oral implant teaching.