scholarly journals An Investigation of Optimum NLC-Sunscreen Formulation Using Taguchi Analysis

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Pao Chi Chen ◽  
Jun-Wei Huang ◽  
Jimmy Pang
Keyword(s):  
Uv Light ◽  
Effect Of Temperature ◽  
Viscosity Change ◽  
Mixture Ratio ◽  
Rheological Analysis ◽  
Taguchi Analysis ◽  
Uv Blocking ◽  
Sunscreen Formulation ◽  
Blackcurrant Oil ◽  
Measured Particle

This study used three kinds of wax and three kinds of oil, with fixed mixture ratio including UV-blocking materials of ethylhexyl methoxycinnamate, oxybenzone, and avobenzone, and applied hot high-pressure homogenization process to prepare nanolipid sunscreen formulations. The measured particle size of the sunscreen formulations was 100~300 nm around PDI of 0.2 having a moderate polydisperse system. The distribution of zeta potential was −50 mV to −35 mV, showing a stable system. The UV light-absorbing range of 9 groups of sunscreen formulations was 275 nm~380 nm ranging within UVA and UVB. The rheological analysis found that the viscosity change is shear, thinning exhibiting colloid behavior. Taguchi analysis found that the optimum combinations are the carnauba wax and the blackcurrant oil combination for crystallinity and the beeswax and CPG oil for UV absorption. In addition, UV-blocking ability shows that the SPF was 51.5 and PFA was three stars for SU9 formulation. Finally, the effect of temperature on the properties of sunscreen formulations was also explored.

scholarly journals The effect of temperature on persistence of SARS-CoV-2 on common surfaces

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Shane Riddell ◽  
Sarah Goldie ◽  
Andrew Hill ◽  
Debbie Eagles ◽  
Trevor W. Drew
Keyword(s):  
Uv Light ◽  
Risk Mitigation ◽  
Survival Rates ◽  
Environmental Stability ◽  
Effect Of Temperature ◽  
Viral Loads ◽  
Different Temperatures ◽  
C 30 ◽  
D Values

Abstract Background The rate at which COVID-19 has spread throughout the globe has been alarming. While the role of fomite transmission is not yet fully understood, precise data on the environmental stability of SARS-CoV-2 is required to determine the risks of fomite transmission from contaminated surfaces. Methods This study measured the survival rates of infectious SARS-CoV-2, suspended in a standard ASTM E2197 matrix, on several common surface types. All experiments were carried out in the dark, to negate any effects of UV light. Inoculated surfaces were incubated at 20 °C, 30 °C and 40 °C and sampled at various time points. Results Survival rates of SARS-CoV-2 were determined at different temperatures and D-values, Z-values and half-life were calculated. We obtained half lives of between 1.7 and 2.7 days at 20 °C, reducing to a few hours when temperature was elevated to 40 °C. With initial viral loads broadly equivalent to the highest titres excreted by infectious patients, viable virus was isolated for up to 28 days at 20 °C from common surfaces such as glass, stainless steel and both paper and polymer banknotes. Conversely, infectious virus survived less than 24 h at 40 °C on some surfaces. Conclusion These findings demonstrate SARS-CoV-2 can remain infectious for significantly longer time periods than generally considered possible. These results could be used to inform improved risk mitigation procedures to prevent the fomite spread of COVID-19.

scholarly journals Lignin as a UV Light Blocker—A Review

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1134 ◽  
Author(s):  
Hasan Sadeghifar ◽  
Arthur Ragauskas
Keyword(s):  
Molecular Weight ◽  
Functional Groups ◽  
Broad Spectrum ◽  
Uv Light ◽  
Complex Structure ◽  
Pulp And Paper ◽  
Transparent Film ◽  
Uv Blocking ◽  
Pulp And Paper Industries ◽  
Modified Forms

Lignin is the by-product of pulp and paper industries and bio-refining operations. It is available as the leading natural phenolic biopolymer in the market. It has chromophore functional groups and can absorb a broad spectrum of UV light in range of 250–400 nm. Using lignin as a natural ingredient in sunscreen cream, transparent film, paints, varnishes and microorganism protection has been actively investigated. Both in non-modified and modified forms, lignin provides enhancing UV protection of commercial products with less than a 10% blend with other material. In mixtures with other synthetic UV blockers, lignin indicated synergic effects and increased final UV blocking potential in compare with using only synthetic UV blocker or lignin. However, using lignin as a UV blocker is also challenging due to its complex structure, polydispersity in molecular weight, brownish color and some impurities that require more research in order to make it an ideal bio-based UV blocker.

scholarly journals Thermal Pyrolysis of Used Lubricant and Cooking Oil Mixtures

2021 ◽  
Vol 7 (2) ◽  
pp. 218
Author(s):  
Nazarudin Nazarudin ◽  
S.P. Amalia ◽  
Afrida Afrida ◽  
Ulyarti Ulyarti
Keyword(s):  
Liquid Fraction ◽  
Effect Of Temperature ◽  
Mixture Ratio ◽  
Cooking Oil ◽  
Thermal Pyrolysis ◽  
Reaction Condition ◽  
Different Temperatures ◽  
Oil Mixtures ◽  
The One ◽  
Semibatch Reactor

Pyrolysis is the one solution to recycle hydrocarbon-based waste material such as used lubricant and cooking oil. The aim of this research was to determine the effect of temperature and sample ratio on the liquid yields of a mixture of used lubricant and cooking oil. The semibatch reactor was used with a constant nitrogen flow rate of 5 mL/min. Three different ratios of sample mixture were applied in this experiment: 0.5:1, 1:1, and 1.5:1, and three different temperatures: 4000C, 4500C, and 5000C. The thermal pyrolysis of a mixture of used lubricant and cooking oil was deemed as the most effective pyrolysis to produce liquid fraction was obtained from reaction condition with the sample mixture ratio of 0.5:1 at 5000C. At this reaction condition, the liquid yields was 58.90% which consist of 64.12% were C1-C3 and 29.54% were C5-C15.  Liquid fraction is predicted to increase as the temperature increase and the ratio of used lubricant to cooking oil decrease. When the ratio is increased , more gas fraction is produced.

The laminar flame speed of propane/air mixtures with heat extraction from the flame

1954 ◽  
Vol 225 (1160) ◽  
pp. 71-96 ◽  
Keyword(s):  
Laminar Flame ◽  
Porous Plate ◽  
Flame Speed ◽  
Heat Extraction ◽  
Effect Of Temperature ◽  
Mixture Ratio ◽  
Flat Flame ◽  
Wide Range ◽  
Cellular Flames ◽  
Good Agreement

This paper describes the measurement of flame speed by means of the flat flame formed downstream of a cooled porous plate through which flows a mixture of propane and air. A flat flame has been stabilized over a wide range of mixture ratios and with flame speeds ranging between 4 and 38 cm/s; the adiabatic flame speeds are obtained by extrapolation. Good agreement is obtained with the results of other investigators as to the effect of temperature on flame speed. Cellular flames are observed in rich, weak and stoichiometric mixtures; cell size varies both with mixture ratio and heat-extraction rate.

scholarly journals PHOTOPROTECTIVE EFFECT OF SUNSCREEN CREAM WITH ADDITION OF CARRAGEENAN AND BLACK MANGROVE FRUIT (Rhizopora mucronata Lamk.)

2015 ◽  
Vol 7 (1) ◽  
Author(s):  
Sri Purwaningsih ◽  
Ella Salamah ◽  
M. Nur Adnin
Keyword(s):  
Emulsion Stability ◽  
Uv Light ◽  
Sun Exposure ◽  
Total Phenol ◽  
Protection Factor ◽  
Fruit Extract ◽  
Light Absorber ◽  
Sun Protection Factor ◽  
Black Mangrove ◽  
Sunscreen Formulation

<p><em>The need of people’s face protection  from sun exposure is </em><em>continuosly increasing</em><em>. However, the available </em><em>sunscreen </em><em>in the market </em><em>are </em><em>mostly chemical</em><em>y generated</em><em>. </em><em>S</em><em>eaweed </em><em>(</em><em><span style="text-decoration: underline;">Kappaphycus</span></em><em> <span style="text-decoration: underline;">alvarezii</span></em><em>)</em><em> produced carrageenan, which can be used as stabilizer, thickener, and emulsifier on sunscreen</em><em> production</em><em>.  Black mangrove fruit</em><em> </em>(<em><span style="text-decoration: underline;">R.</span></em><em> <span style="text-decoration: underline;">mucronata</span></em>)<em> contains an antioxidant activity, tanin, flavonoids, and phenolic compounds, </em><em>which are</em><em> potential to be used for UV light absorber as well as </em><em>skin</em><em> </em><em>protector</em><em>. </em><em>The aim</em><em>s</em><em> of this research </em><em>were </em><em>to determine</em><em>: (1)</em><em> the best carrageenan concentration </em><em>in the</em><em> cream; (2) content of total phenol, flavonoids, and tannin of mangrove fruit extract; and (3) </em><em>Sun Protection Factor</em><em> (SPF) value of</em><em> </em><em>sunscreen cream.  The experiment used a complete random design  and with Duncan test.  The result showed that the best natural sunscreen formulation was </em><em>an</em><em> addition </em><em>of </em><em>0.5% carrageenan and 1%  extract  from <span style="text-decoration: underline;">R.</span> <span style="text-decoration: underline;">mucronata</span>. </em><em>The best characteristics of natural sunscreen were found within the level of 7</em><em>.</em><em>62 pH, 38.250 cP viscosity, 100% emulsion stability, </em><em> </em><em>3</em><em>.</em><em>72% shrinkage, and  &lt;10<sup>2</sup> colonies/g total microbial, 10.21 ± 0.06  SPF content,  37.90% total phenol,  0.51% total flavonoids, and 6.20 mg/g tannins.</em></p> <p> </p> <strong><em>Keywords:</em></strong><em> antioxidant, carrageenan, flavonoids, <span style="text-decoration: underline;">Rhizophora</span> <span style="text-decoration: underline;">mucronata</span>, SPF</em>

scholarly journals Degradation of Dazomet by Thermal Fenton and Photo-Fenton Processes under UV and Sun lights at Different Temperatures

2018 ◽  
Vol 15 (2) ◽  
pp. 158-168
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thermodynamic Functions ◽  
Reaction Rate ◽  
Uv Light ◽  
Reaction Rate Constant ◽  
Effect Of Temperature ◽  
Fenton Process ◽  
Fenton Reagents ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Sun Light

In this research, the degradation of Dazomet has been studied by using thermal Fenton process and photo-Fenton processes under UV and lights sun. The optimum values of amounts of the Fenton reagents have been determined (0.07g FeSO4 .7H2O, 3.5µl H2O2) at 25 °C and at pH 7 where the degradation percentages of Dazomet were recorded high. It has been found that solar photo Fenton process was more effective in degradation of Dazomet than photo-Fenton under UV-light and thermal Fenton processes, the percentage of degradation of Dazomet by photo-Fenton under sun light are 88% and 100% at 249 nm and 281 nm respectively, while the percentages of degradation for photo-Fenton under UV-light are 87%, 96% and for thermal Fenton are 70% and 66.8% at 249 nm and 281 nm respectively. In this research the effect of temperature on all the reactions has been studied in the range 25°C-45°C, it has been noticed that the reaction rate constant (k) has increased with increasing temperature, and the best percentage degradation of Dazomet was at 45°C in all processes, so, the thermodynamic functions ?G*, ?H*, ?S* have been calculated

Stability of Recombinant Mosaic Adeno-Associated Virus Vector rAAV/DJ/CAG at Different Temperature Conditions

2021 ◽  
Vol 17 (11) ◽  
pp. 2114-2124
Author(s):  
Alicja Bie´nkowska-Tokarczyk ◽  
Maciej Małecki
Keyword(s):  
Gene Therapy ◽  
Uv Light ◽  
Temperature Fluctuations ◽  
Effect Of Temperature ◽  
Transduction Efficiency ◽  
Microscopy Imaging ◽  
Adeno Associated Virus ◽  
Targeted Gene Delivery ◽  
Gene Therapy Vectors ◽  
The Stability

The nanometer size and biological characteristics of recombinant adeno-associated virus vectors (rAAV) make them particularly useful as gene therapy vectors and they have been successfully used in this role. Our latest research revealed that the rAAV/DJ/CAG mosaic vector offers highly efficient targeted gene delivery to melanoma cells metastasized to the lungs and that the transduction is temperature dependent. In order to further explore the ability of the rAAV/DJ/CAG vector to deliver highly selective transduction, this study was designed to identify the transduction stability of rAAV/DJ/CAG under various conditions. The temperatures used in this study ranged from −196 ° (liquid nitrogen) to 90 °, and the effect of temperature fluctuations (freeze-thaw, cooling-heating cycles) was also studied. This research also investigated the effects of UV radiation (ultraviolet) on the rAAV/DJ/CAG activity. Changes in the transduction efficiency were assessed via fluorescence microscopy imaging and the qPCR method. Under the test conditions, the transduction efficiency was reduced by approx. 35%, on average. High temperatures (70 °/90 °) and UV light proved to have the most detrimental impact. Changes in the stability of the rAAV/DJ/CAG structure are manifested by variations in the number of genome copies (gc) and GFP+ cells. Temperature fluctuations resulted in differences in the number of gc while maintaining a similar number of GFP+ cells, which may indicate specific changes in the rAAV/DJ/CAG structure, triggering disorders or degradation in the vector entry. This study provides interesting insights into rAAV/DJ/CAG, and the implications of these findings provide a basis for developing new protocols in cancer gene therapy.

scholarly journals Dragon’s Blood Sap: Storage Stability and Antioxidant Activity

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2641 ◽  
Author(s):  
Juan Escobar ◽  
Cristina Prieto ◽  
Maria Pardo-Figuerez ◽  
José Lagaron
Keyword(s):  
Phenolic Compounds ◽  
Storage Stability ◽  
Uv Light ◽  
Light Exposure ◽  
Consumer Products ◽  
Effect Of Temperature ◽  
High Concentration ◽  
Dragon’S Blood ◽  
Different Temperatures ◽  
Ft Ir

Currently, consumers are demanding additive-free, fresher, and more-natural products. Dragon’s Blood Sap (DBS), the deep red latex of the specie of tree Croton lechleri (Müll. Arg.), contains a high concentration of phenolic compounds of great interest for the food, pharmaceutical, and cosmetic industries. These chemical compounds are highly susceptible to degradation. Therefore, DBS storage stability and its photo-oxidation was studied by Fourier transform infrared spectroscopy (FT-IR) and UV-Vis spectrophotometry for 39 days at different temperatures (4–21 °C) and relative humidities (0–56%), as well as under UV light exposure. It was observed that the degradation of phenolic compounds was reduced at 0% relative humidity (RH), not showing a significant effect of temperature in the range studied. UV light irradiation degraded DBS in a 20%. DBS has an exceptional high and stable antioxidant content (≥93% inhibition percentage of DPPH), which makes it a unique property to consider the DBS as an antioxidant agent or ingredient for consumer products formulations.

The Application of Thermal Insulation Glazed Hollow Bead Concrete in Tunnel Cooling Structure

2012 ◽  
Vol 226-228 ◽  
pp. 1699-1703 ◽  
Author(s):  
Ke Jie Li ◽  
Zhu Li ◽  
Xiu Hua Guo ◽  
Yuan Zhen Liu
Keyword(s):  
Thermal Insulation ◽  
Effect Of Temperature ◽  
Insulation Material ◽  
Tunnel Wall ◽  
Mixture Ratio ◽  
Deep Mine ◽  
Mining Depth ◽  
Exhaust Heat ◽  
Mine Roadway ◽  
Coefficient Of Heat Conductivity

With the mining depth increasing, the effect of temperature on coal mine is outstanding with each passing day. In order to enhance the tunnel insulating layer heat insulation effect, thermal insulation glazed hollow bead concrete will be used in tunnel wall thermal insulation layer, the characteristics of thermal insulation glazed hollow bead concrete will be discussed and the appropriate mixture ratio and coefficient of heat conductivity will also be determined, as well as in the basis of reasonable theoretical analysis and derivation, prediction of the thermal insulation material of surrounding rock after exhaust heat will drop significantly, and it is proved that the thermal insulation glazed hollow bead concrete used in deep mine roadway can produce the benefit and have broad prospects.

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