DEVELOPMENT OF A RAPID CONTINUOUS FLOW SALT LEACHING KIT FOR FABRICATION OF POLY(3-HYDROXYBUTYRIC ACID-CO-3-HYDROXYVALERATE) (PHBV) POROUS 3-D SCAFFOLD

2015 ◽  
Vol 75 (1) ◽  
Author(s):  
Syazwan Aizad ◽  
Badrul Hisham Yahaya ◽  
Saiful Irwan Zubairi

Polyhydroxyalkanoates (PHAs) that are synthesized from bacteria that are predominantly produced by microbial fermentation processes on organic waste, such as palm oil mill effluent (POME), olive oil and kitchen waste, contribute to a sustainable waste management. A great variety of materials from this family can be produced, however the application of PHAs in the production of scaffolds in tissue engineering has been mainly constrained to poly(hydroxybutyrate-co-valerate) (PHBV) due to its highly adjustable physico-chemical properties. One of the common methods in making the 3-D scaffolds is by performing solvent-casting particulate-leaching (SCPL) process, but this process requires a long period of soaking in water to extract the entire salt particle in the 3-D scaffolds. Therefore, the objective of this study is to develop a new method to the conventional method of salt leaching process via a highly efficient continuous flow leaching kit. The salt leaching process was carried out by (1) immersing the 3-D porous scaffolds in a fabricated static container containing tap water and (2) by allowing a pre-setting continuous flow rate of water. The concentration of sodium chloride (NaCl) was calculated periodically for both processes based on the salt standard calibration curve. The results showed that the exhaustive salt leaching of the conventional process occurred at 48 ± 5 hrs with the needs of changing the water twice a day. In contrast, the exhaustive salt leaching process via continuous flow leaching kit occurred at 40 ± 5 mins, 72 times faster than the conventional method (p<0.05). Therefore, the salt leaching process using continuous flow leaching kit can be considered a highly efficient and time saving procedure as compared to the conventional method.  

1997 ◽  
Vol 35 (11-12) ◽  
pp. 77-80 ◽  
Author(s):  
A. Wiedenmann ◽  
M. Braun ◽  
K. Botzenhart

A simple continuous flow device in which bacteria were immobilised on membrane filters and flushed with tap water with free chlorine residuals of 0.05, 0.1, 0.2 and 0.4mg/L at pH 7.7 and 10°C, has been used for disinfection experiments with faecal streptococci. A 99.99% reduction of Enterococcus faecium was observed between 3.4–5.2min (0.05mg/L), between 2.8–4.1min (0.1mg/L), between 1.7–3.1min (0.2mg/L) and between 0.8–2.1min (0.4mg/L). CT-products covered a range of 0.17 (0.05mg/L, lower limit) up to 0.85mg/L/min (0.4mg/L, upper limit). The test system is suggested as a more reliable alternative to batch experiments when the disinfection potential of low chlorine concentrations acting for several minutes has to be evaluated. The system cannot be used to demonstrate exact reduction kinetics but it allows the calculation of CT values and the evaluation of the disinfection potential of chlorinated water at any point of a distribution system where initial chlorine concentrations may have already remarkably declined.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 571
Author(s):  
Willy Irakoze ◽  
Hermann Prodjinoto ◽  
Séverin Nijimbere ◽  
Jean Berchmans Bizimana ◽  
Joseph Bigirimana ◽  
...  

Salinity may strongly influence the interaction between plant roots and surrounding soil, but this has been poorly studied for sodium sulfate (Na2SO4). The aim of this study was to investigate the effect of sodium chloride (NaCl) and Na2SO4 salinities on the soil chemical properties as well as rice physiological- and yield-related parameters of two contrasted cultivars (V14 (salt-sensitive) and Pokkali (salt-resistant)). Pot experiments were conducted using soil and electrolyte solutions, namely NaCl and Na2SO4, inducing two electrical conductivity levels (EC: 5 or 10 dS m−1) of the soil solutions. The control treatment was water with salt-free tap water. Our results showed that soil pH increased under Na2SO4 salinity, while soil EC increased as the level of saline stress increased. Salinity induced an increase in Na+ concentrations on solid soil complex and in soil solution. NaCl reduced the stomatal density in salt-sensitive cultivar. The total protein contents in rice grain were higher in V14 than in Pokkali cultivar. Saline stress significantly affected all yield-related parameters and NaCl was more toxic than Na2SO4 for most of the studied parameters. Pokkali exhibited a higher tolerance to saline stress than V14, whatever the considered type of salt. It is concluded that different types of salts differently influence soil properties and plant responses and that those differences partly depend on the salt-resistance level of the considered cultivar.


2012 ◽  
Vol 29 (7) ◽  
pp. 931-934 ◽  
Author(s):  
Jong-Seok Park ◽  
Youn-Mook Lim ◽  
Min-Ho Youn ◽  
Hui-Jeong Gwon ◽  
Young-Chang Nho

2011 ◽  
Vol 13 (19) ◽  
pp. 5008-5011 ◽  
Author(s):  
François Lévesque ◽  
Peter H. Seeberger

2018 ◽  
Vol 28 (4) ◽  
pp. 169-178 ◽  
Author(s):  
Hyun-Ju Hwang ◽  
Yong Tae Kim ◽  
Nam Seon Kang ◽  
Jong Won Han

The algal cell wall is a potent barrier for delivery of transgenes for genetic engineering. Conventional methods developed for higher plant systems are often unable to penetrate or remove algal cell walls owing to their unique physical and chemical properties. Therefore, we developed a simple transformation method for <i>Chlamydomonas reinhardtii</i> using commercially available enzymes. Out of 7 enzymes screened for cell wall disruption, a commercial form of subtilisin (Alcalase) was the most effective at a low concentration (0.3 Anson units/mL). The efficiency was comparable to that of gamete lytic enzyme, a protease commonly used for the genetic transformation of <i>C. reinhardtii</i>. The transformation efficiency of our noninvasive method was similar to that of previous methods using autolysin as a cell wall-degrading enzyme in conjunction with glass bead transformation. Subtilisin showed approximately 35% sequence identity with sporangin, a hatching enzyme of <i>C. reinhardtii</i>, and shared conserved active domains, which may explain the effective cell wall degradation. Our trans­formation method using commercial subtilisin is more reliable and time saving than the conventional method using autolysin released from gametes for cell wall lysis.


Author(s):  
J. S. Chin ◽  
A. H. Lefebvre

The influence of fuel composition on soot emissions from continuous flow combustors is examined. A study of the combustion characteristics of a wide range of present and potential aviation fuels suggests that smoke point provides a better indication of sooting tendency than does hydrogen content. It is concluded from this study that the best empirical relationship between fuel chemical composition and soot emissions is one which combines two fuel composition parameters — smoke point and naphthalene content — into a single parameter which is shown to correlate successfully soot emissions data acquired from several different fuels burning in a variety of gas turbine and model combustors.


ChemCatChem ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 2195-2205 ◽  
Author(s):  
Anton Cunillera ◽  
Carolina Blanco ◽  
Aitor Gual ◽  
Jakob Maximilian Marinkovic ◽  
Eduardo J. Garcia‐Suarez ◽  
...  

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