scholarly journals Microfluidic Chamber Design for Controlled Droplet Expansion and Coalescence

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 394
Author(s):  
Mark Kielpinski ◽  
Oliver Walther ◽  
Jialan Cao ◽  
Thomas Henkel ◽  
J. Michael Köhler ◽  
...  
Keyword(s):  
Ph Value ◽  
Salt Content ◽  
Fluid Viscosity ◽  
Volumetric Expansion ◽  
Chamber Design ◽  
Operation Modes ◽  
Microfluidic Chamber ◽  
Operation Unit ◽  
The One ◽  
Individual Droplet

The defined formation and expansion of droplets are essential operations for droplet-based screening assays. The volumetric expansion of droplets causes a dilution of the ingredients. Dilution is required for the generation of concentration graduation which is mandatory for many different assay protocols. Here, we describe the design of a microfluidic operation unit based on a bypassed chamber and its operation modes. The different operation modes enable the defined formation of sub-µL droplets on the one hand and the expansion of low nL to sub-µL droplets by controlled coalescence on the other. In this way the chamber acts as fluidic interface between two fluidic network parts dimensioned for different droplet volumes. Hence, channel confined droplets of about 30–40 nL from the first network part were expanded to cannel confined droplets of about 500 to about 2500 nL in the second network part. Four different operation modes were realized: (a) flow rate independent droplet formation in a self-controlled way caused by the bypassed chamber design, (b) single droplet expansion mode, (c) multiple droplet expansion mode, and (d) multiple droplet coalescence mode. The last mode was used for the automated coalescence of 12 droplets of about 40 nL volume to produce a highly ordered output sequence with individual droplet volumes of about 500 nL volume. The experimental investigation confirmed a high tolerance of the developed chamber against the variation of key parameters of the dispersed-phase like salt content, pH value and fluid viscosity. The presented fluidic chamber provides a solution for the problem of bridging different droplet volumes in a fluidic network.

scholarly journals CRUDE CATHEPSIN ACTIVITY AND QUALITY CHARACTERISTIC OF SMOKED CATFISH [Pangasius pangasius (Hamilton, 1882)] PROCESSED BY DIFFERENT SMOKING TEMPERATURE

2016 ◽  
Vol 78 (4-2) ◽  
Author(s):  
Fronthea Swastawati ◽  
Ahmad Ni’matullah Al Baarri ◽  
Tri Winarni Agustini ◽  
Eko Nurcahya Dewi ◽  
Ima Wijayanti ◽  
...  
Keyword(s):  
Moisture Content ◽  
Ph Value ◽  
Protein Solubility ◽  
Salt Content ◽  
Quality Characteristic ◽  
Cathepsin Activity ◽  
Textural Changes

The aim of this research was to investigate the effect of smoking temperature towards crude cathepsin activity and quality characteristic of smoked catfish [Pangasius pangasius (Hamilton, 1882)]. Different smoking temperature had  significant  effect (p < 0.05) on crude cathepsin activity, texture, pH, moisture content, salt content and protein solubility. The significant decreasing (30.13 %) of crude cathepsin activity was at P3 (80 °C) from P1 (40 °C to 50 °C). Many factors were correlated to the textural changes of smoked catfish such as changes of crude cathepsin activity, reduction of protein solubility and pH value. 

scholarly journals The COM-Poisson Process for Stochastic Modeling of Osmotic Inactivation Dynamics of Listeria monocytogenes

2021 ◽  
Vol 12 ◽  
Author(s):  
Pierluigi Polese ◽  
Manuela Del Torre ◽  
Mara Lucia Stecchini
Keyword(s):  
Listeria Monocytogenes ◽  
Poisson Process ◽  
Poisson Distribution ◽  
Population Distribution ◽  
Salt Content ◽  
Total Variance ◽  
Good Concordance ◽  
The One ◽  
Osmotic Treatment ◽  
Over Dispersion

Controlling harmful microorganisms, such as Listeria monocytogenes, can require reliable inactivation steps, including those providing conditions (e.g., using high salt content) in which the pathogen could be progressively inactivated. Exposure to osmotic stress could result, however, in variation in the number of survivors, which needs to be carefully considered through appropriate dispersion measures for its impact on intervention practices. Variation in the experimental observations is due to uncertainty and biological variability in the microbial response. The Poisson distribution is suitable for modeling the variation of equi-dispersed count data when the naturally occurring randomness in bacterial numbers it is assumed. However, violation of equi-dispersion is quite often evident, leading to over-dispersion, i.e., non-randomness. This article proposes a statistical modeling approach for describing variation in osmotic inactivation of L. monocytogenes Scott A at different initial cell levels. The change of survivors over inactivation time was described as an exponential function in both the Poisson and in the Conway-Maxwell Poisson (COM-Poisson) processes, with the latter dealing with over-dispersion through a dispersion parameter. This parameter was modeled to describe the occurrence of non-randomness in the population distribution, even the one emerging with the osmotic treatment. The results revealed that the contribution of randomness to the total variance was dominant only on the lower-count survivors, while at higher counts the non-randomness contribution to the variance was shown to increase the total variance above the Poisson distribution. When the inactivation model was compared with random numbers generated in computer simulation, a good concordance between the experimental and the modeled data was obtained in the COM-Poisson process.

scholarly journals Heavy Non-ferrous Metals Adsorption from Water Solutions with Granular Filtering Materials Based on Silicon Rock

2018 ◽  
Author(s):  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Ph Value ◽  
Salt Content ◽  
Human Beings ◽  
Waste Waters ◽  
Metal Compounds ◽  
Physical Chemical ◽  
Siliceous Rocks

Water factor plays an important role in formation of healthy environment for human beings. Due to unfavorable anthropogenic impact upon environment certain surface and groundwater water supply sources are contaminated with heavy metal compounds. Clints (siliceous rocks) are considered the most promising materials for the natural and waste waters treatment from such ingredients. The paper presents the results of the siliceous rocks’ physical/chemical and operational properties studying. It has been shown that these siliceous rocks satisfy all requirements to filtering materials. Methods of physical/chemical analysis were applied for studying the adsorption processes nature. It was for the first time stated (with methods of potentiometric titration and infra-red spectroscopy) that siliceous rocks included the fixed functional ion-exchange groups in their composition and were subacid cationits. Beside chemical adsorption heavy metal ions interact with siliceous rocks due to the action of their physical nature forces. Physical adsorption contributes the most in the heavy metal compounds up-taking by filtering materials, this is supported by the fact of low values of the process activation energy: from 3 to 8 kJ/gram-molecule. Parameters of the process of heavy metal ions adsorption with siliceous rocks in static and dynamic conditions have been calculated in accordance with the experimental results. Influence of salt content and the liquid phase pH value on the adsorption process has been stated. Optimal conditions for the worked siliceous rocks regeneration have been determined. New data on heavy metals cations adsorption with nuclear filtering materials confirm principal possibility of their use for natural and waste waters treatment.

scholarly journals CHARACTERISTICS OF FRUIT FERMENTATION OF ANNONA MONTANA FRUIT USING SACCHAROMYCES CEREVICIAE

2021 ◽  
Vol 4 (2) ◽  
pp. 99-111
Author(s):  
Ambar Fidya Sari
Keyword(s):  
Ph Value ◽  
Chemical Characteristic ◽  
Research Data ◽  
Total Acid ◽  
Three Stages ◽  
The One ◽  
Post Hoc ◽  
Physical And Chemical ◽  
The Impact ◽  
One Way Anova

Soursop mountain (Annona montana Macf) is a genus of Annonaceae, which contains metabolite compounds and antioxidant activity. Mountain soursop fermentation process is carried out with the addition of yeast Saccharomyces cereviciae which can convert carbohydrates into ethanol and organic acid.. The study is aimed at knowing the impact of the duration of the fermentation on the Soursop mountain on physical and chemical characteristics as a natural preservative. The study involves three stages, beginning with the production of mountain-source-juice, then fermentation, and testing of physical characteristics involving organoleptic (colour, aroma, taste, and texture), pH, and viscosity, whereas on the chemical characteristic that is total acid. Research data is analyzed by the One Way Anova method when there is a valid influence followed by the Post Hoc Tukey at real levels α=5%. Changes in physical and chemical grade values include organoleptic (yellow whiteness, aroma scent of the tape, a slightly thick liquid texture (soft) and no gloating, a very sour taste, a 3,86 pH value, a viscosity 583,33 cp, and a total acetate acid 0,4281%.Keywords: Annona Montana; fermentation ;Saccharomyces cereviciae

scholarly journals Effects of Continuous Cropping of Dictyophora on Soil Physical and Chemical Properties, Microbial Biomass and Enzyme Activity

2021 ◽  
Vol 8 (7) ◽  
pp. 214-220
Author(s):  
Long Tong ◽  
◽  
Hongyan Li ◽  
Xiaoming Liu ◽  
Bin Li ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Ph Value ◽  
Chemical Properties ◽  
Available Phosphorus ◽  
Continuous Cropping ◽  
Physical And Chemical Properties ◽  
Factors Affecting ◽  
The One ◽  
Physical And Chemical ◽  
And Chemical Properties

The continuous obstacle of Dictyophora indusiata has become the one of the main factors affecting the healthy development of D. indusiata industry. In order to study the effects of continuous cropping of D. indusiata on the soil environment, four treatments were used in this study: no planted (CK), planted for 1 years (1Y), continuous cropping for 2 years (2Y) and continuous cropping for 3 years (3Y), to determined of the yield of D. indusiata, soil physical and chemical properties, microbial content and enzyme activity. The results showed that the yield and soil pH value decreased with the increase of continuous cropping years, and the contents of organic matter, total nitrogen, total phosphorus and total potassium, C/N and C/P also increased with the increase of continuous cropping years. Soil availability decreased with the increase of continuous cropping years, the content of alkaline nitrogen, available phosphorus and available potassium decreased by 12.25%, 28.91% and 24.86% at 3Y compared with 1Y, respectively. The biomass of bacteria, actinomycetes and fungi and the total amount of microorganism in soil increased at 1Y compared with CK, but with the increase of continuous cropping years, the biomass of bacteria and actinomycetes and the total amount of microorganism decreased significantly, while the biomass of fungi increased significantly; the continuous cropping of D. indusiata also decreased the value of bacteria/fungi in soil. The enzyme activities of the soil were higher than those of the unplanted plots, however, the activities of urease, catalase, peroxidase, sucrase, phosphatase and protease decreased with the increase of continuous cropping years. In a word, with the increase of continuous cropping, the acidity of rhizosphere soil increased, the availability of soil nutrients and the activity of soil enzymes decreased, the biomass of soil microorganisms, bacteria and actinomycetes decreased. However, the increase of fungal biomass led to the decline of soil texture.

scholarly journals Highly efficient removal of thallium(I) by facilely fabricated amorphous titanium dioxide from water and wastewater

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Gaosheng Zhang ◽  
Jinglin Luo ◽  
Hanlin Cao ◽  
Shengping Hu ◽  
Huosheng Li ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
High Efficiency ◽  
Ph Value ◽  
Hydroxyl Group ◽  
Precipitation Method ◽  
Solution Ph ◽  
Surface Complexes ◽  
Environmental Friendliness ◽  
Mining Wastewater ◽  
The One

AbstractIn this study, amorphous hydrous titanium dioxide was synthesized by a facile precipitation method at room temperature, aiming to effectively remove thallium(I) from water. The titanium dioxide prepared using ammonia as precipitant (TiO2I) is more effective for thallium(I) uptake than the one synthesized with sodium hydroxide (TiO2II). The TiO2 obtained particles are amorphous, aggregates of many nanoparticles and irregular in shape. The thallium(I) uptake increases with the rise of solution pH value. Under neutral pH conditions, the maximal thallium(I) adsorption capacities of TiO2I and TiO2II are 302.6 and 230.3 mg/g, respectively, outperforming most of the reported adsorbents. The amorphous TiO2 has high selectivity towards thallium(I) in the presence of multiple cations such as K+, Ca2+, Mg2+, Zn2+ and Ni2+. Moreover, the TiO2I is efficient in removing thallium(I) from real river water and mining wastewater. Additionally, the spent TiO2I can be regenerated using hydrochloric acid solution and reused. The Tl(I) adsorption is achieved via replacing the H+ in hydroxyl group on the surface of TiO2 and forming inner-sphere surface complexes. Owing to its high efficiency, facile synthesis and environmental friendliness, the TiO2I has the potential to be used as an alternative adsorbent to remove Tl(I) from water.

Reduction of Biogenic Amines during Miso Fermentation by Lactobacillus plantarum as a Starter Culture

2016 ◽  
Vol 79 (9) ◽  
pp. 1556-1561 ◽  
Author(s):  
YI-CHEN LEE ◽  
HSIEN-FENG KUNG ◽  
YA-LING HUANG ◽  
CHIEN-HUI WU ◽  
YU-RU HUANG ◽  
...  
Keyword(s):  
Biogenic Amines ◽  
Lactobacillus Plantarum ◽  
Biogenic Amine ◽  
Ph Value ◽  
Starter Culture ◽  
Salt Content ◽  
Total Volatile ◽  
Total Volatile Basic Nitrogen ◽  
Basic Nitrogen ◽  
Control Samples

ABSTRACTLactobacillus plantarum D-103 isolated from a miso product that possesses amine-degrading activity was used as a starter culture in miso fermentation (25°C for 120 days) in this study. The salt content in control samples (without starter culture) and inoculated samples (inoculated with L. plantarum D-103) remained constant at 10.4% of the original salt concentration throughout fermentation, whereas the pH value decreased from 6.2 to 4.6 during fermentation. The inoculated samples had significantly lower (P &lt; 0.05) levels of total volatile basic nitrogen than control samples after 40 days of fermentation. After 120 days of fermentation, the histamine and overall biogenic amine contents in inoculated samples were reduced by 58 and 27%, respectively, compared with control samples. To our knowledge, this is the first report to demonstrate that application of a starter culture with amine-degrading activity in miso products was effective in reducing the accumulation of biogenic amines.

Ecological Improvement of Fraxinus velutina Forest on Heavy Saline-Alkali Soil

2014 ◽  
Vol 692 ◽  
pp. 143-148
Author(s):  
Xing Xia Lu ◽  
Ting Liu ◽  
Jing Hui Yang ◽  
Yan Jun Liu ◽  
Jun Xuan Huang
Keyword(s):  
Organic Matter ◽  
Forest Soil ◽  
Ph Value ◽  
Salt Content ◽  
Chemical Properties ◽  
Exchange Capacity ◽  
Growth Stages ◽  
Stages Of Growth ◽  
Alkali Soil ◽  
Fraxinus Velutina

In order to discuss improving effect of ecological forest on heavy saline-alkali soil and to provide reference for biological improvement of saline-alkali soil, the soil chemical properties (pH, salt content, organic matter, available potassium and cation exchange capacity) of 20cm-depth in four different stages of growth on pure forest of Fraxinus velutina planted on heavy saline-alkali soil were studied. The results showed that pH value of forest soil in other stages of growth except defoliating stage was lower than that of CK, pH value in flowering stage decreased by 0.77 unit, and the decrease was the largest. The organic matter obviously increased in four different stages of growth, but the best effect of soil organic matter improvement was defoliating stage. During defoliating stage in mid-October, salt content of forest soil was 1/2 of CK, and cation exchange capacity was three point two nine times of CK. The available potassium of forest soil obviously increased in flowering stage and peak leafing stage. All in all, there was greater effect for the soil chemical properties of 20cm-depth in different growth stages of pure forest of Fraxinus velutina, so when salt-tolerance plant was used to improve saline-alkali soil, we should use scientific measure to cultivation and management in consideration of requirement of different growth stages of forest for soil water and soil nutrient in order to consolidate the improving achievements and to accelerate the improving process.

Experiment Study of Dredger Fill Using Different Consolidation Methods

2014 ◽  
Vol 960-961 ◽  
pp. 513-516
Author(s):  
Huan Yan ◽  
Qing Wang ◽  
Dong Yan Sun
Keyword(s):  
Ph Value ◽  
Water Discharge ◽  
Salt Content ◽  
Liquid Limit ◽  
Soil Samples ◽  
Soluble Salt ◽  
Vacuum Preloading ◽  
Port Area ◽  
Dredger Fill ◽  
Physical And Chemical

At present, there are many methods of the dredger fill foundation treatment, in which the most widely used application of vacuum preloading method. The dredger fill for test was taken from the Tianjin Binhai new area center fishing port area, separately carried on the self-weight consolidation and vacuum preloading consolidation. Through the indoor test of soil test physical and chemical parameters, comparing the moisture content, soluble salt amount and component, caption exchange capacity, PH value and physical and chemical index. The results show that: the clay content of soil sample in the central fishing port area is higher, degree of aggregation is high, liquid limit is less than 60%, Ip is more than 10, belongs to the low liquid limit clay. Relative self-weight consolidation, soluble salt content of soil samples after vacuum preloading drainage treatment are low, but the particle size composition change less. It is said that parts of salt in the soil samples discharge with water discharge in vacuum preloading process, vacuum preloading effect is better. Introduction All manuscripts must be in English, also the table and figure texts; otherwise we cannot publish your paper.

scholarly journals Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex

2012 ◽  
Vol 3 (2) ◽  
pp. 180-183
Author(s):  
Marcelo Ferrarezi de Andrade ◽  
Renato de Toledo Leonardo ◽  
Edson Alves de Campos ◽  
Milton Carlos Kuga ◽  
Marco Antonio Hungaro Duarte ◽  
...  
Keyword(s):  
Calcium Hydroxide ◽  
Calcium Release ◽  
Ph Value ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Ph Values ◽  
The One ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

ABSTRACT Objective This study evaluated the flow, pH and calcium release of MTA Fillapex (G1) or Fillapex plus 10% in weight of calcium hydroxide powder (G2), compared to AH Plus (G3) and Sealapex (G4). Materials and methods The flow test was performed according to ISO 6876:2001 requirements. The sealers were placed into plastic tubes and immersed in deionized water. After 24 hours, 7, 14 and 28 days, the water of each tube was removed and tested to evaluate the pH values and the level of released calcium. Calcium release values were analyzed statistically by Kruskal Wallis and Dunn tests and pH values analyzed by ANOVA and Tukey tests (α = 5%). Results G1 presented higher flow among all sealers. The addition of 10% calcium hydroxide into MTA Fillapex reduced the flow (p < 0.05) but, in a level, that is lower than the one recommended for ISO norms. G2 and G4 presented pH values and calcium release higher than G3 (p < 0.05) in all periods. G1 presented pH value higher than G3 (p < 0.05), except in 7 days period (p > 0.05). G4 presented higher pH values than G1 and G2, but the calcium release was similar for all periods (p > 0.05). G3 presented lower calcium release among all groups (p < 0.05). Conclusion The addition of 10% calcium hydroxide in MTA Fillapex caused reduction in flow and no negative interference in pH and/or calcium release. However, the obtained flow is different from ISO requirements. Clinical relevance MTA Fillapex presents levels of flow above the ISO norms. The addition of calcium hydroxide is a suggestion for solving this problem, but the impact of these procedures should be carefully evaluated. How to cite this article Keine KC, Guiotti FA, Leonardo RT, Kuga MC, Duarte MAH, de Campos EA, de Andrade MF. Influence of the Addition of Calcium Hydroxide Powder on Some Physical and Chemical Properties of the Sealer MTA Fillapex. World J Dent 2012;3(2):180-183.

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