scholarly journals Thermal resistance and high-performance microwave decontamination assessment of Bacillus endospores isolated from food-grade herbal extracts

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261988
Author(s):  
Armin Tarrah ◽  
Shadi Pakroo ◽  
Milena Carlot ◽  
Camilla Nesto ◽  
Antonella Cirillo ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Product Quality ◽  
High Performance ◽  
Treatment Time ◽  
Centella Asiatica ◽  
Herbal Extracts ◽  
16S Rrna Analysis ◽  
Microwave Technique ◽  
Bacterial Endospores ◽  
Tilia Tomentosa

Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract against the mixture of Bacillus spores. Results from the microwave technique indicate that the increase of temperature from 100°C to 105°C not only decontaminated the product but also could dramatically decrease the effective thermal treatment time (10 times), which can benefit the product quality. The results provided in this study considerably contribute to improving an original decontamination method for products containing glycerol and ethanol with the most negligible effect on product quality.

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

Thermal Behaviors of Passively-Cooled Hybrid Fin Heat Sinks for Lightweight and High Performance Thermal Management

2015 ◽  
Author(s):  
Nico Setiawan Effendi ◽  
Kyoung Joon Kim
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
High Performance ◽  
Heat Dissipation ◽  
Computational Study ◽  
Heat Sinks ◽  
Channel Diameter ◽  
Internal Channel ◽  
Study Results ◽  
Parametric Effects

A computational study is conducted to explore thermal performances of natural convection hybrid fin heat sinks (HF HSs). The proposed HF HSs are a hollow hybrid fin heat sink (HHF HS) and a solid hybrid fin heat sink (SHF HS). Parametric effects such as a fin spacing, an internal channel diameter, a heat dissipation on the performance of HF HSs are investigated by CFD analysis. Study results show that the thermal resistance of the HS increases while the mass-multiplied thermal resistance of the HS decreases associated with the increase of the channel diameter. The results also shows the thermal resistance of the SHF HS is 13% smaller, and the mass-multiplied thermal resistance of the HHF HS is 32% smaller compared with the pin fin heat sink (PF HS). These interesting results are mainly due to integrated effects of the mass-reduction, the surface area enhancement, and the heat pumping via the internal channel. Such better performances of HF HSs show the feasibility of alternatives to the conventional PF HS especially for passive cooling of LED lighting modules.

The Product Portfolio and Man's Best Friend

1982 ◽  
Vol 25 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Donald C. Hambrick ◽  
Ian C. MacMillan
Keyword(s):  
Product Quality ◽  
High Performance ◽  
Product Portfolio ◽  
Best Friend

Boston Consulting Group's Dogs reconsidered: Their efficiency, superior product quality, and focus mean high performance.

Adding herbal extracts to silicone gel on post-sternotomy scar: a prospective randomised double-blind study

2020 ◽  
Vol 29 (Sup4) ◽  
pp. S36-S42
Author(s):  
Palakorn Surakunprapha ◽  
Kengkart Winaikosol ◽  
Bowornsilp Chowchuen ◽  
Kriangsak Jenwitheesuk ◽  
Kamonwan Jenwitheesuk
Keyword(s):  
Aloe Vera ◽  
Median Sternotomy ◽  
Centella Asiatica ◽  
Herbal Extract ◽  
Double Blind Study ◽  
Herbal Extracts ◽  
Double Blind ◽  
Silicone Gel ◽  
Group 2 ◽  
Group 1

Objective: Silicone gel has been shown effective in improving healing post-sternotomy scars. It remains to be determined whether adding herbal extracts to the gel would augment the healing effect. Method: After median sternotomy, patients were randomised into two groups. Group 1: topical silicone gel plus herbal extract gel (Allium cepa, Centella Asiatica, Aloe vera and Paper Mulberry) and Group 2: silicone gel. Patients were treated for six months. The postoperative scars were assessed at three and six months by plastic surgeons using the Vancouver Scar Scale (VSS) and the patient assessment scar scale. Results: Each group comprised 23 patients (n=46 in total). The VSS was significantly lower in Group 1 than in Group 2 (p=0.018 and p=0.051, respectively). In Group 1, the four differences from baseline were vascularity scores at three and six months (–0.391, p=0.025; –0.435, p=0.013, respectively), and pigmentation scores at three and six months (–0.391, p=0.019; –0.609, p=0.000, respectively). In Group 2, differences from baseline were the pigmentation and vascularity score at six months (–0.6609, p=0.000; –0.348, p=0.046, respectively). Conclusion: Our results suggest, post-sternotomy scars trend to have better vascularity and pigmentation when treated with silicone gel plus herbal extracts.

In Situ Measurement of Thermal Resistance of Building Envelope at the Residential Occupancy in Indonesia

2015 ◽  
Vol 771 ◽  
pp. 191-194 ◽  
Author(s):  
Wahyu Sujatmiko ◽  
Hermawan Kresno Dipojono ◽  
F.X. Nugroho Soelami ◽  
Soegijanto
Keyword(s):  
Thermal Resistance ◽  
High Performance ◽  
Building Materials ◽  
Precast Concrete ◽  
Green Building ◽  
Building Envelope ◽  
Building Wall ◽  
Ashrae Standards ◽  
Building Walls

Abstract. This paper presents the measurement results of three building wall materials which are commonly used for residential housings in Indonesia, namely clay brick, batako (concrete brick), and precast concrete. In-situ measurement of the steady state thermal flow (heat flux) at building walls (envelopes) is conducted in order to determine the thermal resistance of building wall according to ASTM C1155. The results show that all three building materials having a thermal resistance values are far below the energy conservation provisions of ASHRAE 90.1 and especially when compared to the provision of high performance green building ASHRAE 189.1 It is found that precast concrete has higher thermal resistance (or has lower thermal conductivity) than that of other two materials, hence a better compliance to the ASHRAE standards.

High Performance and Sub-Ambient Silicon Microchannel Cooling

2006 ◽  
Author(s):  
E. G. Colgan ◽  
B. Furman ◽  
M. Gaynes ◽  
N. LaBianca ◽  
J. H. Magerlein ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
High Performance ◽  
Water Flow Rate ◽  
Cooling Water ◽  
Interface Layer ◽  
Inlet Temperature ◽  
Chip Surface ◽  
Thermal Interface ◽  
Performance Improvements ◽  
Average Unit

High performance single-phase Si microchannel coolers have been designed and characterized in single chip modules in a laboratory environment using either water at 22°C or a fluorinated fluid at temperatures between 20 and −40°C as the coolant. Compared to our previous work, key performance improvements were achieved through reduced channel pitch (from 75 to 60 microns), thinned channel bases (from 425 to 200 microns of Si), improved thermal interface materials, and a thinned thermal test chip (from 725 to 400 microns of Si). With multiple heat exchanger zones and 60 micron pitch microchannels with a water flow rate of 1.25 lpm, an average unit thermal resistance of 15.9 C-mm2/W between the chip surface and the inlet cooling water was demonstrated for a Si microchannel cooler attached to a chip with Ag epoxy. Replacing the Ag epoxy layer with an In solder layer reduced the unit thermal resistance to 12.0 C-mm2/W. Using a fluorinated fluid with an inlet temperature of −30°C and 60 micron pitch microchannels with an Ag epoxy thermal interface layer, the average unit thermal resistance was 25.6 C-mm2/W. This fell to 22.6 C-mm2/W with an In thermal interface layer. Cooling >500 W/cm2 was demonstrated with water. Using a fluorinated fluid with an inlet temperature of −30°C, a chip with a power density of 270 W/cm2 was cooled to an average chip surface temperature of 35°C. Results using both water and a fluorinated fluid are presented for a range of Si microchannel designs with a channel pitch from 60 to 100 microns.

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