scholarly journals Determining Sonication Effect on E. coli in Liquid Egg, Egg Yolk and Albumen and Inspecting Structural Property Changes by Near-Infrared Spectra

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 398
Author(s):  
David Nagy ◽  
Jozsef Felfoldi ◽  
Andrea Taczmanne Bruckner ◽  
Csilla Mohacsi-Farkas ◽  
Zsanett Bodor ◽  
...  
Keyword(s):  
Ultrasonic Treatment ◽  
Near Infrared ◽  
Cooling System ◽  
Power Level ◽  
Free Water ◽  
Egg Yolk ◽  
E Coli ◽  
Egg Products ◽  
Absorbed Power ◽  
Energy Dose

In this study, liquid egg, albumen, and egg yolk were artificially inoculated with E. coli. Ultrasound equipment (20/40 kHz, 180/300 W; 30/45/60 min) with a circulation cooling system was used to lower the colony forming units (CFU) of E. coli samples. Frequency, absorbed power, energy dose, and duration of sonication showed a significant impact on E. coli with 0.5 log CFU/mL in albumen, 0.7 log CFU/mL in yolk and 0.5 log CFU/mL decrease at 40 kHz and 6.9 W absorbed power level. Significant linear correlation (p < 0.001) was observed between the energy dose of sonication and the decrease of E. coli. The results showed that sonication can be a useful tool as a supplementary method to reduce the number of microorganism in egg products. With near-infrared (NIR) spectra analysis we were able to detect the structural changes of the egg samples, due to ultrasonic treatment. Principal component analysis (PCA) showed that sonication can alter C–H, C–N, –OH and N–H bonds in egg. The aquagrams showed that sonication can alter the properties of H2O structure in egg products. The observed data showed that the absorbance of free water (1412 nm), water molecules with one (1440 nm), two (1462 nm), three (1472 nm) and four (1488 nm) hydrogen bonds, water solvation shell (1452 nm) and strongly bonded water (1512 nm) of the egg samples have been changed during ultrasonic treatment.

scholarly journals Photoelectronic Properties of End-bonded InAsSb Nanowire Array Detector under Weak Light

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiaomei Yao ◽  
Xutao Zhang ◽  
Tingting Kang ◽  
Zhiyong Song ◽  
Qiang Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cooling System ◽  
Variable Temperature ◽  
Light Trapping ◽  
Nanowire Array ◽  
Infrared Light ◽  
Laser Source ◽  
Array Detector ◽  
Weak Light ◽  
Gap States

AbstractA simple fabrication of end-bonded contacts InAsSb NW (nanowire) array detector to weak light is demonstrated in this study. The detector is fabricated using InAsSb NW array grown by molecular beam epitaxy on GaAs substrate. The metal-induced gap states are induced by the end-bonded contact which suppresses the dark current at various temperatures. The existence of the interface dipole due to the interfacial gap states enhances the light excitation around the local field and thus upgrades the photoresponsivity and photodetectivity to the weak light. The light intensity of the infrared light source in this report is 14 nW/cm2 which is about 3 to 4 orders of magnitude less than the laser source. The responsivity of the detector has reached 28.57 A/W at room temperature with the light (945 nm) radiation, while the detectivity is 4.81 × 1011 cm·Hz1/2 W−1. Anomalous temperature-dependent performance emerges at the variable temperature experiments, and we discussed the detailed mechanism behind the nonlinear relationship between the photoresponse of the device and temperatures. Besides, the optoelectronic characteristics of the detector clarified that the light-trapping effect and photogating effect of the NWs can enhance the photoresponse to the weak light across ultraviolet to near-infrared. These results highlight the feasibility of the InAsSb NW array detector to the infrared weak light without a cooling system.

scholarly journals Performance Study of a Floricultural Greenhouse Surrounded by Shallow Water Ponds

2017 ◽  
Vol 6 (2) ◽  
pp. 137
Author(s):  
Debajit Misra ◽  
Sudip Ghosh
Keyword(s):  
Shallow Water ◽  
Water Surface ◽  
Natural Ventilation ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Free Water ◽  
Weather Data ◽  
Ventilation Mode ◽  
Performance Study ◽  
Tropical Regions

In the present paper, an innovative low energy-intensive evaporative cooling system has been proposed for greenhouse application in near-tropical regions dominated by hot climate. The system can operate under dual- ventilation mode to maintain a favourable microclimate inside the greenhouse. A single ridge type un-even span greenhouse has been considered, targeting a few species of Indian tropical flowers. The greenhouse has a continuous roof vent as well as adjustable side vents and is equipped with exhaust fans on top and roll-up curtains on the sides. The greenhouse is surrounded by shallow water ponds outside its longitudinal walls and evaporative surfaces partially cover the free water surface. Inside the pond, low cost evaporative surfaces are so placed that they form air channels.  Thus, outside air flows through the channels formed by the wetted surfaces over the water surface and undergoes evaporative cooling before entering the greenhouse. A simplified theoretical model has been presented in this paper to predict the inside greenhouse air temperature while ambient weather data are used as model inputs. The study reveals that during average radiation periods, the greenhouse can depends solely on natural ventilation and during peak radiation hours fan-induced ventilation is needed to maintain the required level of temperature. It is seen that under dual-ventilation mode greenhouse, temperature can be kept 3-6 oC lower than ambient temperature when saturation effectiveness is 0.7 and with 75% shading. Keywords: Greenhouse, Evaporative Cooling, Ventilation, Saturation Effectiveness, Wetted SurfaceArticle History: Received February 25th 2017; Received in revised form April 14th 2017; Accepted May 4th 2017; Available onlineHow to Cite This Article: Misra, D. and Ghosh, S., (2017) Performance Study of a Floricultural Greenhouse Surrounded by Shallow Water Ponds. International Journal of Renewable Energy Develeopment, 6(2), 137-144.https://doi.org/10.14710/ijred.6.2.137-144

scholarly journals Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-drug Release, Antimicrobial, and Photothermal Conversion Functions

2021 ◽  
Author(s):  
Zheng Su ◽  
Daye Sun ◽  
Li Zhang ◽  
Miaomiao He ◽  
Yulin Jiang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Drug Release ◽  
Composite System ◽  
Near Infrared ◽  
Environment Friendly ◽  
Photothermal Conversion ◽  
E Coli ◽  
Nanocomposite System ◽  
Dual Drug

In this work, we designed and fabricated a multifunctional nanocomposite system which consists of chitosan, raspberry-like silver nanoparticles and graphene oxide. Room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environment-friendly method for introducing silver nanoparticles into the composite system. By loading different drugs onto the polymer matrix and/or graphene oxide, our composite can achieve a pH controlled dual drug release with release profile specific to the drugs used. In addition to its strong antibacterial ability against E. coli and S. aureus, our composite also demonstrates excellent photothermal conversion effect under irradiation of near infrared lasers. These unique functionalities point to it&rsquo;s the potential of nanocomposite system in multiple applications areas such as multimodal therapeutics in healthcare, water treatment, and anti-microbial, etc.

scholarly journals Photothermal-assisted antibacterial application of GO-Ag against clinical isolated MDR E. coli

2019 ◽  
Author(s):  
Yuqing Chen ◽  
Wei Wu ◽  
Zeqiao Xu ◽  
Cheng Jiang ◽  
Shuang Han ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Near Infrared ◽  
Antibacterial Effect ◽  
Luria Bertani ◽  
Fluorescent Imaging ◽  
Photothermal Effect ◽  
Antibacterial Efficiency ◽  
E Coli ◽  
Morphology Characterization

Abstract Background: Treatment of multidrug-resistant (MDR) bacterial infection is a great challenge in public health. Herein, we provide a solution to this problem with the use of graphene oxide-silver (GO-Ag) nanocomposites as anti-bacterial agent. Methods: Following established protocols, silver nanoparticles were grown on graphene oxide sheets. Then, a series of in-vitro studies were conducted to validate the antibacterial efficiency of the GO-Ag nanocomposites against clinical MDR Escherichia coli (E. coli) strains. Firstly, minimum inhibitory concentrations (MICs) of different antimicrobials were tested against MDR E. Coli strains. Then, bacteria viability assessments were conducted with different nanomaterials in Luria-Bertani (LB) broth. Afterwards, photothermal irradiation was conducted on MDR E. coli with lower GO-Ag concentration. At last, fluorescent imaging and morphology characterization using scanning electron microscope (SEM) were done to find the possible cause of antibacterial effect. Results: GO-Ag nanocomposites showed the highest antibacterial efficiency among tested antimicrobials. Synergetic antibacterial effect was observed in GO-Ag nanocomposites treated group. The remained bacteria viabilities were 4.4% and 4.1% respectively for different bacteria strains with GO-Ag concentration at 14.0 µg mL-1. In addition, GO-Ag nanocomposites have strong absorption in the near-infrared field and can convert the electromagnetic energy to heat. With the use of this photothermal effect, effective sterilization could be achieved using GO-Ag nanocomposites concentration as low as 7.0 µg mL-1. Fluorescent imaging and morphology characterization were used to analyze bacteria living status, which uncovered that bacteria integrity was disrupted after GO-Ag nanocomposites treatment. Conclusions: GO-Ag nanocomposites are proved to be efficient antibacterial agent against multi-drug resistant E. coli. Their strong antibacterial effect arises from inherent antibacterial property and photothermal effect that provides aid for bacteria killing.

scholarly journals Photoelectronic Properties of End-bonded InAsSb Nanowire Array Detector under Weak Light

2021 ◽  
Author(s):  
Xiaomei Yao ◽  
Xutao Zhang ◽  
Tingting Kang ◽  
Zhiyong Song ◽  
Qiang Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Cooling System ◽  
Variable Temperature ◽  
Light Trapping ◽  
Nanowire Array ◽  
Infrared Light ◽  
Laser Source ◽  
Array Detector ◽  
Weak Light ◽  
Gap States

Abstract A simple fabrication of end-bonded contacts InAsSb NW (nanowire) array detector to weak light is demonstrated in this study. The detector is fabricated using InAsSb NW array grown by molecular beam epitaxy on GaAs substrate. The MIGS (metal-induced gap states) is induced by the end-bonded contact which suppresses the dark current at various temperatures. The existence of the interface dipole due to the interfacial gap states enhances the light excitation around the local field, thus upgrade the photo responsivity and photo detectivity to the weak light. The light intensity of the infrared light source in this report is 14 nW/cm2 which is about 3 to 4 orders of magnitude less than the laser source. The responsivity of the detector has reached 28.57 A/W at room temperature with the light (945 nm) radiation, while the detectivity is 4.81×1011 cm·Hz1/2 W−1. Anomalous temperature-dependent performance emerges at the variable temperature experiments, and we discussed the detailed mechanism behind the non-linear relationship between the photoresponse of the device and temperatures. Besides, the optoelectronic characteristics of the detector clarified that the light trapping effect and photogating effect of the NWs can enhance the photoresponse to the weak light across ultraviolet to near-infrared. These results highlight the feasibility of the InAsSb NW array detector to the infrared weak light without a cooling system.

scholarly journals HOW DOES CRYOGENIC FREEZING AFFECT THE CALORIMETRIC PROPERTIES OF LIQUID EGG PRODUCTS?

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidas Karina Ilona ◽  
Ildikó Csilla Nyulas-Zeke ◽  
László Friedrich ◽  
Anna Visy ◽  
Judit Csonka ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Frozen Storage ◽  
Colour Change ◽  
Egg Yolk ◽  
Egg White ◽  
Dry Matter Content ◽  
Scanning Calorimetry ◽  
Egg Products ◽  
Liquid Whole Egg ◽  
Whole Egg

Eggs are widely utilized because of their high nutrient value, coagulating, foaming, emulsifying and sometimes even colouring or flavouring facilities in food manufacturing. Production of processed egg products shows an increasing trend. Frozen products belong to first processing, their shelf life can increase up to 1 year. By freezing, a large reduction in microbial loss can be achieved. But different undesirable processes can occur. The effect of freezing on animal cells is highly dependent on freezing parameters. It has a different effect on egg subtituents. Egg yolk undergoes a gelation process while proteins can denaturate. In our study pasteurized liquid egg products (liquid egg white, liquid egg yolk and liquid whole egg) were frozen by dripping into liquid nitrogen. After that, a 14-day frozen storage experiment was carried out at -18°C. Before freezing and on the 1th, 7th and 14th days of storage experiment pH, dry matter content, colour and calorimetric properties (denaturation temperatures and enthalpy of denaturation) with differential scanning calorimetry were tested. For statistical analysis, one-way ANOVA (α = 0.05) was employed. In our experiment, we found no significant change in calorimetric properties of liquid egg white after freezing, but significant decreasing of enthalpy and denaturation temperatures of liquid egg yolk and liquid whole egg was identified. In contrast, frozen storage had a decreasing effect in all these products. Freezing caused a clearly visible colour change in LEW, a visible change in colour of LWE and a very clearly visible change in colour of LEY. In case of LEW and LEY changes increased to clearly visible 14 days. In conclusion, our results show that frozen storage had a greater effect on liquid egg products properties than freezing in liquid nitrogen.

Coupling Immunofluorescence and Optoelectrokinetic Technique for Escherichia Coli Detection and Quantification in Water

2018 ◽  
Author(s):  
Uzumma O. Ozeh ◽  
A. G. Agwu Nnanna ◽  
Justus C. Ndukaife
Keyword(s):  
Traditional Method ◽  
Free Water ◽  
Culturable Bacteria ◽  
Inorganic Contaminants ◽  
E Coli ◽  
Ac Electric Field ◽  
Large Pool ◽  
Microfluidic Chamber ◽  
Timely Access ◽  
Patterning Technique

At least 2 billion people worldwide drink water from sources contaminated with feces, in other words, sources contaminated with E. coli. The traditional method for detecting E. coli, among other limitations, detects only culturable bacteria and takes about 24–48 hours to yield a result. Consequently, the aim of this work is to develop a rapid diagnostic procedure for E. coli by combining immunofluorescence and optoelectrokinetic patterning to specifically target and sensitively trap the whole organism. This is to ensure the populace have timely access to sustained “E. coli-free” water for both domestic and recreational activities. The procedure involves conjugation of streptavidin functionalized superparamagnetic fluorescent micro-beads with biotin-labelled anti-E. coli polyclonal antibody. The conjugate is introduced into a water sample containing E. coli among other contaminants, where it specifically and sensitively targets the bacteria in the sample solution which is quantified using an optoelectrokinetic patterning technique by introducing the targeted organism in a fabricated microfluidic chip and trapping it with an application of both laser beam and AC electric field simultaneously. Preliminary experiments have shown that increasing concentrations of E. coli in the microfluidic chamber varies directly with the electrical resistance of the entire system. This on-going research has the potential of sensitively isolating E. coli from a large pool of organic and inorganic contaminants in water in less than 4 hours.

Application of Phase Change Materials to Thermal Control of Electronic Modules: A Computational Study

1997 ◽  
Vol 119 (1) ◽  
pp. 40-50 ◽  
Author(s):  
D. Pal ◽  
Y. K. Joshi
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Cooling System ◽  
Computational Study ◽  
Power Level ◽  
Thermal Control ◽  
The Other ◽  
Three Dimensions ◽  
Temperature Isotherm ◽  
Laminate Thickness

A computational model is developed to predict the performance of phase change materials(PCMs) for passive thermal control of electronic modules during transient power variations or following an active cooling system failure. Two different ways of incorporating PCM in the module are considered. One is to place a laminate of PCM outside the multichip module, and the other is to place the PCM laminate between the substrate and the cold plate. Two different types of PCMs are considered. One is n-Eicosene, which is an organic paraffin, and the other one is a eutectic alloy of Bi/Pb/Sn/In. Computations are performed in three dimensions using a finite volume method. A single domain fixed grid enthalpy porosity method is used to model the effects of phase change. Effects of natural convection on the performance of PCM are also examined. Results are presented in the form of time-wise variations of maximum module temperature, isotherm contours, velocity vectors, and melt front locations. Effects of PCM laminate thickness and power levels are studied to assess the amount of PCM required for a particular power level. The results show that the PCMs are an effective option for passive cooling of high density electronic modules for transient periods.

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