Investigation of Initial Bubbles of CO2 Injected into Polymer Melt

2011 ◽  
Vol 311-313 ◽  
pp. 2127-2131
Author(s):  
Hao Hua Zeng ◽  
Xiao Dan Wu

Continuous extrusion foaming of CO2gas is an efficient method to produce microcellular. The CO2concentration in polymer melt is related to initial bubble morphology. Using video recording in this paper bubble interfacial morphology was studied when the gas was injected into polymer melt . The process of single bubble formation in the static and dynamic polymer melt includes three stages. Screw was more effective for gas breaking up and separating. When mixed in screw channel, and blent in the mixing segment, the dispersion, and diffusion rate of gas into polymer melt were increased largely.

2014 ◽  
Vol 607 ◽  
pp. 629-632
Author(s):  
Yan Yan ◽  
Yu Sheng Zhang

Taking into account China's abundant coal resources, methanol and DME(Dimethyl Ether) obtained from coal are good alternative fuels. The research project is to utilize the fuel of DME and methanol in diesel engines for new combustion models PCCI (Premixed Charge Compression Ignition).The tests of the PCCI mode with different boundary conditions were studied on PCCI test bench. PCCI combustion is consisted of three stages: low temperature reaction of DME, high-temperature reaction of DME and diffusion combustion reaction of methanol. DME as combustion improver should be kept relatively low concentration, and with the decrease of methanol, its concentration need to be reduced. Methanol and formaldehyde are important parts of HC emission, their volume fraction was about 70%.


1977 ◽  
Vol 42 (5) ◽  
pp. 758-760 ◽  
Author(s):  
B. A. Hills

Gaseous supersaturation can be induced under steady-state conditions when two inert gases are transmitted in opposite directions across any system comprising a diffusion barrier adjacent to a zone of limited convective capacity. This has many implications for bubble formation in vivo and can explain the occurence of symptoms of decompression sickness without decompression.


2005 ◽  
Vol 79 (1) ◽  
pp. 622-625 ◽  
Author(s):  
Hillel Haim ◽  
Israel Steiner ◽  
Amos Panet

ABSTRACT To override the diffusion-limited adsorption step of viral infection, we magnetically synchronized cell attachment. Human immunodeficiency virus type 1-based lentivirus preparations were rendered magnetically reactive by association with magnetite nanoparticles, 50 nm in diameter. Application of a magnetic field resulted in immediate redistribution of the viral inoculum to the cell-associated state and completion of the productive adsorption process within 1 min. Independent of adsorption time, viral concentration, and diffusion rate, infection subsequently progressed by the receptor-mediated entry mechanism. Synchronization of this rate-limiting step of infection may now be applied to analyze isolated events in the viral replication sequence.


2018 ◽  
Vol 174 ◽  
pp. 03005
Author(s):  
L. Benussi ◽  
S. Bianco ◽  
G. Saviano ◽  
S. Muhammad ◽  
D. Piccolo ◽  
...  

Systematic studies on the GEM foil material are performed to measure the moisture diffusion rate and saturation level. These studies are important because the presence of this compound inside the detector’ s foil can possibly change its mechanical and electrical properties, and in such a way, the detector performance can be affected. To understand this phenomenon, a model is developed with COMSOL Multiphysics v. 4.3 [1], which described the adsorption and diffusion within the geometry of GEM foil, the concentration profiles and the time required to saturate the foil. The COMSOL model is verified by experimental observations on a GEM foil sample. This note will describe the model and its experimental verification results.


2021 ◽  
Vol 4 (1) ◽  
pp. 27-32
Author(s):  
Tania Intan ◽  
Ferli Hasanah ◽  
Sri Rijati Wardiani ◽  
Vincentia Tri Handayani

Abstract: Good living behavior is a community habit that upholds health aspects, such as managing cleanliness and environmental health, maintaining physical and psychological fitness, and providing adequate nutritional intake to achieve good health standards. Community Service Activities regarding the culture of healthy living during this pandemic were carried out by a teaching team from the Faculty of Humanities Sciences, Padjadjaran University. The activity method used is education with techniques of extension, consultation, and diffusion of knowledge which are all held virtually. To obtain comprehensive data, the implementation team distributed a questionnaire about the culture of healthy living to the primary target public, namely students of the Faculty, and the secondary target public, namely student families. Activities were carried out in July 2020 in three stages, namely the preparation, implementation, and evaluation stages. The results of the activity showed that PPM activities regarding healthy cultural behavior to the public of students and their families were well organized and following the protocol for preventing the transmission of Covid-19. Also, it is known that the biggest impact of a pandemic is economic. Keywords: covid-19; culture of healthy living; pandemic; virtual socialization  Abstrak: Perilaku hidup sehat adalah kebiasaan masyarakat yang menjunjung tinggi aspek-aspek kesehatan, seperti pengelolaan kebersihan dan kesehatan lingkungan, menjaga kebugaran fisik dan psikis, serta pemberian asupan nutrisi yang cukup sehingga tercapai standar kesehatan yang baik. Kegiatan Pengabdian Pada Masyarakat tentang budaya hidup sehat di masa pandemi ini dilakukan oleh tim pengajar dari Fakultas Ilmu Budaya Universitas Padjadjaran. Metode kegiatan yang digunakan adalah pendidikan dengan teknik penyuluhan, konsultasi, dan difusi ilmu pengetahuan yang seluruhnya diselenggarakan secara virtual. Untuk mendapatkan data yang komprehensif, tim pelaksana mendistribusikan angket mengenai budaya hidup sehat pada publik sasaran primer, yaitu mahasiswa, dan publik sasaran sekunder, yaitu keluarga mahasiswa. Kegiatan dilakukan pada bulan Juli 2020 dalam tiga tahap, yaitu tahap persiapan, pelaksanaan, dan evaluasi. Hasil kegiatan menunjukkan bahwa kegiatan PPM mengenai perilaku budaya sehat kepada publik mahasiswa dan keluarganya telah terselenggara dengan baik dan sesuai dengan protokol pencegahan penularan Covid-19. Selain itu diketahui bahwa dampak terbesar dari pandemi adalah ekonomi. Kata kunci: budaya hidup sehat; Covid-19; pandemic; sosialisasi virtual


Author(s):  
LUSI NURDIANTI ◽  
RISNA CLARA ◽  
HENDY SUHENDY ◽  
FAJAR SETIAWAN ◽  
KENI IDACAHYATI

Objective: Astaxanthin is one of the natural carotenoids with strong antioxidant characteristics which is widely used in skin care. The aim of this study was developed to formulate and characterize the antioxidant serum containing astaxanthin nanoemulsion and the diffusion rate studies using diffusion Franz method. Methods: Astaxanthin nanoemulsion (As-NE) was prepared by using the self-nanoemulsifying method, followed by incorporation into serum preparation with the using carbomer as a gelling agent. Evaluation of serum As-NE was performed by physical, chemical characterizations and diffusion assay. Stability study was carried out in both accelerated (temperature of 40±2 °C/75±5%RH) and non-accelerated (at ambient temperature) conditions. Results: These results suggest that antioxidant serum As-NE had good physical and chemical characteristics that are suitable for topical administration. Conclusion: For the study of diffusion and stability under different storage conditions, it was proven that antioxidant serum As-NE form was packed in a carbomer as a gelling agent that could enhance the stability and diffusion rate of the astaxanthin.


2021 ◽  
Vol 3 (2) ◽  
pp. 78-86
Author(s):  
Gabena Indrayani Dalimunthe ◽  
Ricky Andi Ayaputra

Diclofenac sodium is a Transfersom is a transdermal delivery system consisting of phospholipids and edge activators. Transfersom increases the size of the stratum corneum lipid barrier pores, then enters the skin through the drive of the trans-barrier motion and squeezes itself to follow the lipid barrier pore size. The purpose of this study is to determine the effect of the tween-80 concentration as an edge activator on the characteristics and diffusion rate of diclofenac sodium transfersom. Transferom preparation used the vortex-sonication method which was made in five formulae with variations in the concentration ratio of phosphatidylcholine and tween-80 (95:05, 90:10, 85:15, 80:20, and 75:25). The results show that all five formulae have different morphological forms. The results of statistical tests using One-Way ANOVA finds a significant effect (p-value) of the edge activator concentration on the diffusion rate of diclofenac sodium transfersom.


2015 ◽  
Vol 656 ◽  
pp. 012042 ◽  
Author(s):  
Xianxian Yu ◽  
Yiwei Wang ◽  
Chenguang Huang ◽  
Tezhuan Du

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