Bubble Electrospinning with an Auxiliary Electrode and an Auxiliary Air Flow

2020 ◽  
Vol 14 (1) ◽  
pp. 42-45 ◽  
Author(s):  
Xiao-Xia Li ◽  
Ji-Huan He
Keyword(s):  
Room Temperature ◽  
Air Flow ◽  
Positive Electrode ◽  
Auxiliary Electrode ◽  
Long Distance ◽  
Effective Technique ◽  
Factors Affecting ◽  
Multiple Jets ◽  
Spinning Process ◽  
Electric Field Force

Background: The patented bubble electrospinning, which is a simple and effective technique for mass-production of polymer nanofibers, has been studying extensively, but it is still under development. In the bubble electrospinning, multiple jets move from the positive electrode to the receptor, a long distance between the two electrodes is needed to guarantee complete solvent evaporation, as a result a relative high voltage is needed. Objective: The aim of the present study is to use an auxiliary electrode and an auxiliary air flow to improve bubble electrospinning with lower voltage and higher output than those by its traditional one. Methods: The modification of the bubble electrospinning with an auxiliary electrode and an auxiliary airflow is used to fabricate nanofibers. The auxiliary electrode is close to the positive electrode. The experiment was carried out at room temperature with 8%PVA solution. The result was analyzed with a S4800 cold field scanning electron microscope (SEM, Hitachi S-4800, Tokyo, Japan). Results: The auxiliary electrode can generate a strong induced electric field force. With the action of airflow, the jets will fly to the receptor instead of the auxiliary electrode. Conclusion: Both auxiliary electrode and auxiliary airflow are two important factors affecting the spinning process. It can reduce the spinning voltage and improve spinning efficiency.

scholarly journals Fractal-like multiple jets in electrospinning process

2020 ◽  
Vol 24 (4) ◽  
pp. 2499-2505
Author(s):  
Yu-Ke Wu ◽  
Yong Liu
Keyword(s):  
Surface Tension ◽  
Electrospinning Process ◽  
Taylor Cone ◽  
Solution Viscosity ◽  
Fiber Morphology ◽  
Factors Affecting ◽  
Multiple Jets ◽  
Spinning Process ◽  
Main Factors

The electrospinning process is greatly affected by the instability of Taylor cone, an instable point can eject a jet, and multiple instable points can produce multiple jets. A fractal-like multi-jet phenomenon was found in electrospinning process with auxiliary electrodes, and main factors affecting the spinning process were studied experimentally, which included solution viscosity, surface tension, and conductivity. The fractal-like multi-jet is feasible to control the fiber morphology and its output.

THE STUDY ON TA VAT WINE PRODUCTION FROM SUGAR PALM (ARENGA PINNATA) SAP

2014 ◽  
Vol 83 (5) ◽  
Author(s):  
Nguyễn Thị Hồng Thu ◽  
Đặng Minh Nhật ◽  
Nguyễn Hoàng Dung
Keyword(s):  
Room Temperature ◽  
Fermentation Process ◽  
Inoculum Size ◽  
Wine Fermentation ◽  
Wine Production ◽  
Factors Affecting ◽  
Natural Fermentation ◽  
Tropical Asia ◽  
Best Parameters

Sugar palm (Arenga pinnata) is a feather palm native to tropical Asia. In Vietnam, it is named Búng Báng or Đoác and grown only on the highlands in the central or northern part of Vietnam. It is utilized for many purposes, especially for Ta Vat wine production - a characteristic and unique product of Co Tu ethnic minority. However, because of the natural fermentation used in the production, the product quality is inconsistent. The purpose of this study was to examine a new procedure of using palm sap for making Ta Vat wine. Some characteristics of the sap, which was collected at Nam Giang district, Quang Nam province are determined, proving the potential of the sap for making wine product. The quality of sap changes quickly at room temperature. At low temperature (4 - 60C), the changes in sap quality are apparently slower. Examining some factors affecting its quality during the wine fermentation process, we determined the best parameters for the fermentation process as follows: inoculum size of 3% with cell density of about 1x108 cells/ml, the addition of the extract from the bark of Ceylon ironwood (Mesua ferrea L.) 4%. Keywords: Arenga pinnata, sap, Ceylon ironwood bark, Mesua ferrea L., wine fermentation.

Microstructure and Mechanical Properties of the Wide-Gap Region Brazed with Various Powder Mixing Ratios of Additive to Filler Metal Powders

2006 ◽  
Vol 118 ◽  
pp. 479-484 ◽  
Author(s):  
Yong Hwan Kim ◽  
S.I. Kwun
Keyword(s):  
Mechanical Properties ◽  
Metal Powder ◽  
Room Temperature ◽  
Filler Metal ◽  
Metal Powders ◽  
Powder Mixing ◽  
Factors Affecting ◽  
Mixing Ratios ◽  
Microstructure And Mechanical Properties ◽  
Wide Gap

This study investigated the microstructure and mechanical properties of the wide-gap region brazed with various powder mixing ratios of additive powder (IN738) to filler metal powder (DF4B). The wide-gap brazing process was carried out in a vacuum of 2×10-5 torr at 1230°C for 1 hr. The microstructure of the brazed region was analyzed by FESEM and AES. The wide-gap region brazed with 60wt.% IN738 additive powder and 40 wt.% DF 4B filler metal powder had a microstructure consisting of Ni solid solution + γ' and (Cr, W)2B. The fracture strength of the wide-gap region brazed with 60 wt.% IN738 additive and 40 wt.% DF 4B powder was as high as 832 MPa at room temperature. It was found that the (Cr, W)2B and pores in the brazed region are important microstructural factors affecting the mechanical properties of the wide-gap brazed region.

scholarly journals Factors affecting poor attendance for outpatient physiotherapy by patients discharged from Mthatha General Hospital with a stroke

2013 ◽  
Vol 69 (3) ◽  
Author(s):  
N.P. Ntamo ◽  
D. Buso ◽  
B. Longo-Mbenza
Keyword(s):  
Health Care ◽  
General Hospital ◽  
Specific Reference ◽  
Clinical Impression ◽  
Long Term Effects ◽  
Structured Interviews ◽  
Stroke Patients ◽  
Long Distance ◽  
Factors Affecting ◽  
Physiotherapy Department

Background: Stroke is a major cause of disability inthe world and its long term effects require adherence to physiotherapyprotocols for optimal rehabilitation. Clinical impression of data fromMthatha General Hospital (MGH) Physiotherapy Department revealedthat there was poor attendance of outpatient physiotherapy by strokepatients discharged from MGH and this had negative effects on outcomesand health care costs.Objective: To determine the extent and the socio-demographic reasonsfor poor attendance for outpatient physiotherapy by stroke patients.Methods: An observational descriptive study was conducted using arandomly selected sample of 103 stroke patients from a population of 139who attended physiotherapy in MGH in 2007. Structured interviews wereconducted and SPSS was used for data analysis.Results: The majority (86%) of patients did not attend physiotherapy until discharge from the Physiotherapy Department. Themajor reasons for poor attendance were lack of finances (95%), migration to other areas (36%), and living a long distance fromMGH (38%).Conclusion: Almost 9 out of 10 stroke patients fail to attend for outpatient physiotherapy because of lack of finances.Recommendation: Development of a Provincial Rehabilitation Policy with specific reference to decentralization of rehabilitationservices to address unavailability of physiotherapy services at clinics and health care centers which are proximal to the patients’residential areas is recommended.

scholarly journals Elastic, inelastic and time constant measurement for M102 (AL–C–O) dispersions-reinforced aluminum alloys

2020 ◽  
pp. 61-66
Author(s):  
Khaleel Abushgair
Keyword(s):  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Time Constant ◽  
Room Temperature ◽  
Strain Range ◽  
Time Interval ◽  
Cnc Milling ◽  
Plastic Deformations ◽  
Factors Affecting ◽  
Bulk Content

Purpose. To conduct an experimental study on M102 aluminum alloy bulk content characterization under cyclic loadings for precision applications such as balance machines, optical, and laser instruments. M102 (AL-C-O) dispersion-reinforced aluminum alloy was chosen because of its ability to withstand temperatures beyond 200C and has a better strength than precipitation-hardened Al alloys at room temperature. A CNC milling machine is used to manufacture test samples with longitudinal machining directions. A constant time interval is set for the fabric a quarter-hour span, which is based on the investigation of inelastic and plastic deformations in the nanoscale. Methodology. An electromagnetic test instrument applies a tensile stress range of 10 to 145 N/mm2 to samples with particular shape. It should be noted that interferometers and capacitive sensors were used to measure all forms of deformations with and without loading. The experiments are carried out in a temperature-stable environment of 30.5 C; measurements are taken within a residual strain range of 10 microns. Findings. The results obtained show that results for inelastic deformations for samples of longitudinal cuts direction at 30.5 C were measured under 150 N/mm2 stress as 500 nm inelastic deformation and 100 nm plastic deformation were measured, which is much higher than aluminum alloy studied before at room temperature (20 C). Furthermore, it was found that the time constant of the M102 (ALCO) aluminum alloy samples was double times higher than that for other samples, Originality. For the first time, a study has been conducted on inelastic and plastic deformations in the nanoscale for characterization of M102 aluminum alloy bulk content under cyclic loadings for precision applications. Practical value. One of the main factors affecting the using of other materials than steel in precision applications such as balance machines, optical, and laser instruments is measurement and determination of inelastic, plastic and time constant of the process of delamination of materials of different aluminum alloys since they are nonmagnetic, are easily machined and shaped. This will bring new products and opportunities for these materials.

Socio-cultural Factors affecting People Living with HIV/AIDS Attendance at Hawassa and Yirgalem Hospital ART Clinics, South Ethiopia. Quantitative and Qualitative Mixed Approach.

2021 ◽  
Author(s):  
Alemante A Ayalew ◽  
Zeytu G Asfaw ◽  
Solomon A Lemma
Keyword(s):  
Cultural Practices ◽  
Cultural Factors ◽  
Complete Healing ◽  
People Living With Hiv ◽  
Long Distance ◽  
Factors Affecting ◽  
Care Givers ◽  
The World ◽  
Living With Hiv ◽  
Hiv Aids

Abstract Background: HIV/AIDS pandemic seriously ravaged the world for the past three decades. It left the world with full of complicated social, economic and political problems. The problem has continued as major health problems for most developing countries, including Ethiopia. Socio-cultural practices which are predominantly determining the life of most of these peoples have structured the spread of HIV/AIDS. The aim of this study was to investigate how socio-cultural factors are affecting patients' adherence at ART clinics in Hawassa and Yirgalem Referral Hospitals. Methods: Qualitative and quantitative designs were used to collect the data. Results: The findings have shown that for fear of stigma and discrimination at family and community levels forced patients' affected adherence at ART clinics. People living with HIV were forced to travel long distance to get rid of social exclusion and isolation that resulting in drug interruptions and drop outs. The findings have also shown that most of the followers of protestant religion make believe that HIV could be cured and boycotted them from taking ART drugs. Moreover, confidentiality of information about HIV positive children living with care givers and newly tested patients found to be resistant to start or continue their drugs. Sense of wellbeing elicited form long term ART drugs effects made patients to imagine complete healing thereby dropping their treatment. Conclusions: The findings made clear that multidimensional socio-cultural factors structure and restructure adherence problems at the ART clinics in the study hospitals. Interventions targeting to change socio-cultural factors play crucial roles to prevent and control new infections, occurrence of drug resistant strains, and social and economic repercussions in the society.

Teleportation of a controlled-NOT gate for photon and electron-spin qubits assisted by the nitrogen-vacancy center

2015 ◽  
Vol 15 (15&16) ◽  
pp. 1397-1419
Author(s):  
Ming-Xing Luo ◽  
Hui-Ran Li
Keyword(s):  
Electron Spin ◽  
Spin System ◽  
Room Temperature ◽  
Coherence Time ◽  
Nitrogen Vacancy ◽  
Cnot Gate ◽  
Long Distance ◽  
Two Photon ◽  
Nitrogen Vacancy Center ◽  
Vacancy Center

Teleportations of quantum gates are very important in the construction of quantum network and teleportation-based model of quantum computation. Assisted with nitrogenvacancy centers, we propose several schemes to teleport the quantum CNOT gate. Deterministic CNOT gate may be implemented on a remote two-photon system, remote two electron-spin system, hybrid photon-spin system or hybrid spin-photon system. Each photon only interacts with one spin each time. Moreover, quantum channel may be constructed by all combinations of the photon or electron-spin entanglement, or their hybrid entanglement. Since these electron-spin systems have experimentally shown a long coherence time even at the room temperature, our schemes provide useful ways for long-distance quantum applications.

scholarly journals Analysis of Transcriptional Activation at a Distance in Saccharomyces cerevisiae

2007 ◽  
Vol 27 (15) ◽  
pp. 5575-5586 ◽  
Author(s):  
Krista C. Dobi ◽  
Fred Winston
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Target Gene ◽  
Core Promoter ◽  
Striking Difference ◽  
Base Pairs ◽  
Long Distance ◽  
Factors Affecting ◽  
Promoter Specificity

ABSTRACT Most fundamental aspects of transcription are conserved among eukaryotes. One striking difference between yeast Saccharomyces cerevisiae and metazoans, however, is the distance over which transcriptional activation occurs. In S. cerevisiae, upstream activation sequences (UASs) are generally located within a few hundred base pairs of a target gene, while in Drosophila and mammals, enhancers are often several kilobases away. To study the potential for long-distance activation in S. cerevisiae, we constructed and analyzed reporters in which the UAS-TATA distance varied. Our results show that UASs lose the ability to activate normal transcription as the UAS-TATA distance increases. Surprisingly, transcription does initiate, but proximally to the UAS, regardless of its location. To identify factors affecting long-distance activation, we screened for mutants allowing activation of a reporter when the UAS-TATA distance is 799 bp. These screens identified four loci, SIN4, SPT2, SPT10, and HTA1-HTB1, with sin4 mutations being the strongest. Our results strongly suggest that long-distance activation in S. cerevisiae is normally limited by Sin4 and other factors and that this constraint plays a role in ensuring UAS-core promoter specificity in the compact S. cerevisiae genome.

scholarly journals Factors affecting developmental competence of equine oocytes after intracytoplasmic sperm injection

Reproduction ◽  
2004 ◽  
Vol 127 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Y H Choi ◽  
L B Love ◽  
D D Varner ◽  
K Hinrichs
Keyword(s):  
Embryo Culture ◽  
Intracytoplasmic Sperm Injection ◽  
Room Temperature ◽  
Culture Media ◽  
Developmental Competence ◽  
Glucose Medium ◽  
Factors Affecting ◽  
Nuclear Maturation ◽  
High Glucose Medium

This study was conducted to evaluate the effect of initial cumulus morphology (expanded or compact) and duration of in vitro maturation (24, 30 or 42 h) on the developmental competence of equine oocytes after intracytoplasmic sperm injection (ICSI). The effect of manipulation temperature (room temperature vs 37 °C) at the time of ICSI and concentration of glucose (0.55 vs 5.5 mM) during embryo culture was also investigated. The nuclear maturation rates of expanded (Ex) oocytes were significantly (P < 0.001) higher than those of compact (Cp) oocytes at all maturation times (61–72 vs 23–25% respectively). Forty-eight hours after ICSI of mature Ex oocytes, the rate of cleavage with normal nuclei was significantly (P < 0.05) higher for oocytes matured for 24 h than for those matured for 30 or 42 h (73 vs 57–59% respectively). For Cp oocytes, the morphologic cleavage rates for oocytes matured for 30 h were significantly higher (P < 0.05) than for those matured for 24 or 42 h (86 vs 55–61% respectively). The overall proportion of embryos having more than four normal nuclei at 48 h culture was significantly higher (P < 0.05) for Cp than for Ex oocytes. Manipulation temperature did not affect development of embryos from Ex or Cp oocytes at 96 h after ICSI. Culture in high-glucose medium significantly increased morphologic cleavage of Cp, but not Ex, oocytes (P < 0.05). Embryos from Cp oocytes had a significantly higher average nucleus number after 96-h culture than did embryos from Ex oocytes. These data indicate that developmental competence differs between Ex and Cp equine oocytes, and is differentially affected by the duration of maturation and by composition of embryo culture media.

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