scholarly journals Effect of Ultraviolet Radiation on Pseudomonas Aeruginosa, Staphylococcus Aureus and Enterococcus

2021 ◽  
pp. 116-123
Author(s):  
B. Madhumitha ◽  
N. P. Muralidharan
Keyword(s):  
Ultraviolet Radiation ◽  
Exposure Time ◽  
Pathogenic Bacteria ◽  
Uv Light ◽  
Solar Spectrum ◽  
Ultraviolet Rays ◽  
Life Saving ◽  
Sterile Normal Saline ◽  
Apparent Decrease ◽  
A Minor

Background: The study of microorganism is called microbiology, which includes bacteria, viruses, fungi and Protozoa. Microbes play a major role in this field. Microbes are also used for life-saving drugs etc.. The effect of ultraviolet rays on the bacterias are mostly lethal to them, UV is a minor fraction of the solar spectrum reaching the ground surfaces, the UV light radiation will reduce the microbes in the surroundings as well as in the labs. Aim: The aim of this study was to evaluate the effect of the ultraviolet rays on pathogenic bacterias. Materials and methods: Three organisms were selected for the study. Pseudomonas, S. Aureus and Enterococcus. 30 watts Uv tube was used to evaluate the antibacterial activity of the Uv radiation. The exposure time was determined as 5, 10 and 15 mins at a close distance of 10cm. 20 microliter of suspension was taken and mixed in 2 ml of sterile normal saline and exposed for respective duration. Sub culture was done on suitable media after the exposure . Time exposed plates were incubated at 37 degree Celsius overnight and checked for the total CFU and data were tabulated. Results: The Ultraviolet radiation of pathogenic bacteria resulted in a significant reduction of the total colony forming unit. Conclusion: Ultraviolet rays were lethal to the bacterias. There are many  airborne bacterias surrounded by environment ultraviolet rays exposure will cause an apparent decrease in the pathogenic bacterias.

scholarly journals Solar Extreme and Far Ultraviolet Radiation Modeling for Aeronomic Calculations

2021 ◽  
Vol 13 (8) ◽  
pp. 1454
Author(s):  
Anatoliy A. Nusinov ◽  
Tamara V. Kazachevskaya ◽  
Valeriya V. Katyushina
Keyword(s):  
Ultraviolet Radiation ◽  
Input Parameter ◽  
Solar Spectrum ◽  
Upper Atmosphere ◽  
Model Calculations ◽  
Radiation Fluxes ◽  
Main Components ◽  
Comparison Of The Results ◽  
Far Ultraviolet ◽  
Radiation Modeling

Modeling the upper atmosphere and ionospheres on the basis of a mathematical description of physical processes requires knowledge of ultraviolet radiation fluxes from the Sun as an integral part of the model. Aeronomic models of variations in the radiation flux in the region of extreme (EUV) and far (FUV) radiation, based mainly on the data of the last TIMED mission measurements of the solar spectrum, are proposed. The EUVT model describes variations in the 5–105 nm spectral region, which are responsible for the ionization of the main components of the earth’s atmosphere. The FUVT model describes the flux changes in the 115–242 nm region, which determines heating of the upper atmosphere and the dissociation of molecular oxygen. Both models use the intensity of the hydrogen Lyman-alpha line as an input parameter, which can currently be considered as one of the main indices of solar activity and can be measured with relatively simpler photometers. A comparison of the results of model calculations with observations shows that the model error does not exceed 1–2% for the FUVT model, and 5.5% for EUVT, which is sufficient for calculating the parameters of the ionosphere and thermosphere.

Inorganic-Organic Hybrid Nanocomposites for Photovoltaic Applications

2012 ◽  
Vol 571 ◽  
pp. 120-124
Author(s):  
Liang Min Zhang
Keyword(s):  
Solar Cells ◽  
Uv Light ◽  
Solar Spectrum ◽  
Wide Band ◽  
Hybrid Nanocomposites ◽  
Wide Band Gap ◽  
Inorganic Semiconductors ◽  
The Cost ◽  
Ruthenium Dye ◽  
Photovoltaic Characteristics

Hybrid photovoltaic concepts based on a nanoscale combination of organic and inorganic semiconductors are promising way to enhance the cost efficiency of solar cells through a better use of the solar spectrum, a higher ratio of interface-to-volume, and the flexible processability of polymers. In this work, two types of thin film solar cells have been developed. In both types of solar cells, poly-N-vinylcarbazole (PVK) is used as electron donor, cadmium sulfide (CdS) and titanium dioxide (TiO2) nanocrystals are used as electron acceptors, respectively. Since TiO2 has a wide band gap and can only absorb UV light, in the second type of solar cell, ruthenium dye is used as photo-sensitizer. The preliminary results of photoconductive and photovoltaic characteristics of these two inorganic-organic composites are presented.

QUINACRINE FLUORESCENCE AND Q-BANDING PATTERNS OF HUMAN CHROMOSOMES.: I. Effects of Varying Factors

1975 ◽  
Vol 17 (1) ◽  
pp. 81-92 ◽  
Author(s):  
C. C. Lin ◽  
H. van de Sande ◽  
W. K. Smink ◽  
D. R. Newton
Keyword(s):  
Exposure Time ◽  
Uv Light ◽  
Human Chromosomes ◽  
Concave Mirror ◽  
Banding Patterns ◽  
Fluorescent Microscope ◽  
Sperm Dna ◽  
Quinacrine Fluorescence ◽  
Well Differentiated ◽  
Salmon Sperm Dna

Various factors involved in the production of "Q-bands" have been studied. It was found that a Zeiss standard WL fluorescent microscope required a shorter exposure time for photography as compared to a Zeiss photomicroscope. The minimal exposure time was obtained when the standard WL microscope was equipped with a UV light source containing a DC powered mercury burner and a concave mirror. Further, the pH and type of water used in the staining, washing and mounting of the slide were also important factors in producing clear and well differentiated "Q-bands". It also appears that the factors involved in the production of "Q-bands" effect the enhancement or quenching of fluorescence by poly d(A-T).poly d(A-T) and salmon sperm DNA or poly dG∙poly dC respectively. This preliminary report also suggests that DNA or polynucleotides with a specific base sequence may play an important role in Q-banding patterns on chromosomes.

Inhibition of Salmonella typhimurium on Agar Medium and Poultry Skin by Ultraviolet Energy

1996 ◽  
Vol 59 (3) ◽  
pp. 319-321 ◽  
Author(s):  
SUSAN S. SUMNER ◽  
EVA A. WALLNER-PENDLETON ◽  
GLENN W. FRONING ◽  
LA VERNE E. STETSON
Keyword(s):  
Ultraviolet Radiation ◽  
Salmonella Typhimurium ◽  
Agar Medium ◽  
Uv Light ◽  
Light Treatment ◽  
Complete Elimination ◽  
Bacterial Reduction ◽  
Colony Forming Units ◽  
Ultraviolet Energy ◽  
Different Doses

Ultraviolet radiation (UV) was effective in destroying Salmonella typhimurium on agar plates and poultry skin. Agar plates inoculated with varying numbers of colony-forming units (CFU) of S. typhimurium (1.2 × 102 to 1.7 × 109) were subjected to different doses of UV light to determine optimal killing. Poultry skin was also inoculated with varying CFU of S. typhimurium per 2 cm2 of skin and subjected to UV light. UV light treatment of inoculated agar plates revealed almost complete elimination (99.9%) of S. typhimurium at 2,000 μW · s · cm−2. Bacterial reduction was less effective on the surface of poultry skin when a 80.5% reduction in S. typhimurium was obtained at 2,000 μW · s · cm−2.

scholarly journals The Effects of Weathering on Mechanical Properties of Glass Fiber Reinforced Plastics (Grp) Materials

1970 ◽  
Vol 1 (2) ◽  
Author(s):  
H. Abdullah ◽  
S. Al Araimi and R. A. Siddiqui
Keyword(s):  
Mechanical Properties ◽  
Relative Humidity ◽  
Ultraviolet Radiation ◽  
Glass Fiber ◽  
Exposure Time ◽  
Atmospheric Conditions ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced ◽  
Fiber Reinforced Plastics

Glass fiber reinforced plastics composite is extensively used as a structural material for pools, oil pipes and tanks because it has good corrosion resistance properties.  The effects of weathering on the mechanical properties of glass fiber reinforced plastics (GRP) in the Sultanate of Oman have been studied.  The tensile and three point bend specimens were exposed to outdoor conditions (open atmosphere) in sunlight and tested for various intervals of time.  It was observed that as the exposure time to sunlight, ultraviolet radiation and dust increases the mechanical properties of GRP materials decrease.  The effects of relative humidity (%RH) on the mechanical properties were also studied. It was found that as the relative humidity increased in the atmosphere during the exposure time, the tensile strength, flexural strength and modulus of elasticity are lowered. This work has revealed that the decrease in the mechanical properties of GRP under weathering conditions is subjected to atmospheric conditions such as humidity, temperature, ultraviolet radiation and pollutant.Key Words: Weathering, Glass-Fiber Reinforced Plastics, Degradation

scholarly journals Ultraviolet Protection Activity of Selected Herbal and Biopolymer for Textile Application

2021 ◽  
Vol 7 (03) ◽  
pp. 80-83
Author(s):  
Dr. Banupriya J and Dr. V Maheshwari
Keyword(s):  
Ultraviolet Radiation ◽  
Research Work ◽  
Herbal Extract ◽  
Ultraviolet Rays ◽  
Ft Ir ◽  
Encapsulation Method ◽  
Ultraviolet Protection ◽  
Chitosan Biopolymer ◽  
Protection Activity ◽  
Finished Sample

The textile protection of human skin against ultraviolet radiation is very important problem and over recent years researches have shown increasing interests in this area. This research work deals with the causing harm effects of ultraviolet rays and protection against them through the woven materials by using Opuntia littoralis herbal extract and Chitosan biopolymer extract with nano encapsulation method. Finishing of fabric with an eco friendly manner is getting very advanced nowadays. So, this research work is fully based on ecofriendly and skin friendly. The samples were imparted with herb and biopolymer nanocapsules which showed best results for ultraviolet protection even after 30 washes.The finished sample was analyzed for its morphology using FESEM and FT-IR.

scholarly journals Semiconducting Nanocrystalline Bismuth Oxychloride (BiOCl) for Photocatalytic Reduction of CO2

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 998
Author(s):  
Dalia Sánchez-Rodríguez ◽  
Alma Berenice Jasso-Salcedo ◽  
Niklas Hedin ◽  
Tamara L. Church ◽  
Aitor Aizpuru ◽  
...  
Keyword(s):  
Band Gap ◽  
Carbon Capture ◽  
Uv Light ◽  
Active Catalyst ◽  
Triethylene Glycol ◽  
Photocatalytic Reduction ◽  
Carbon Capture And Utilization ◽  
Reduction Of Co2 ◽  
A Minor ◽  
Band Gap Tuning

The reduction of CO2 is relevant for the production of compounds as part of the carbon capture and utilization research approaches. Thus, photocatalytic reduction of CO2 over a tailored BiOCl-based photocatalyst (BTEG) was tested under UV light (365 nm). BTEG was synthesized in the presence of triethylene glycol, which gave 4-nm crystallites, much smaller than the 30 nm crystallites of commercial BiOCl. Commercial BiOCl reduced CO2 mainly to methane with a minor fraction of ethanol, and was inactivated after 20 h. BTEG was a more active catalyst for CO2 photoreduction, producing approximately equal amounts of methane, methanol, and ethanol while consuming 0.38 µmol g−1 h−1 of CO2 before the experiment was stopped after 43 h, with the catalyst still active. The different products formed by the BTEG photocatalyst samples were tentatively ascribed to its greater content of {110} facets. Thus, in addition to band-gap tuning, the relative fractions of BiOCl facets had a key role in the effective photocatalytic reduction of CO2, and the BiOCl-based BTEG catalyst promoted the formation of important compounds as methanol and ethanol.

scholarly journals Use of Flavonoids and Cinnamates, the Main Photoprotectors with Natural Origin

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Alesandra R. Nunes ◽  
Ícaro G. P. Vieira ◽  
Dinalva B. Queiroz ◽  
Antonio Linkoln Alves Borges Leal ◽  
Selene Maia Morais ◽  
...  
Keyword(s):  
Ultraviolet Radiation ◽  
The Sun ◽  
Uvb Radiation ◽  
Natural Origin ◽  
Cosmetic Industry ◽  
Response To Stress ◽  
A Minor ◽  
Plant Compounds ◽  
Cellular Alterations ◽  
Uva Radiation

Many pathological problems are initiated by ultraviolet radiation (UVR), such as skin cancer, the most commonly diagnosed cancer worldwide. The UVA (320–400 nm) and UVB (290–320 nm) wavelengths may cause effects such as photoaging, DNA damage, and a series of cellular alterations. The UVA radiation can damage the DNA, oxidize the lipids, and produce dangerous free radicals, which can cause inflammation, modify the gene expression in response to stress, and weaken the skin immune response. With a minor penetration, the UVB radiation is more harmful, being responsible for immediate damage. Ultraviolet radiation light emitted by the sun is considered necessary for the existence of life but cause radiation problems, especially in the skin. The photoprotective activities of plant extracts and isolated composts were evaluated by many reports, as well as the correlation of these compounds with the antioxidant activity. This review presents plant compounds with interest to the cosmetic industry to be used in sunscreens such as flavonoids and cinnamates.

scholarly journals Testing of resveratrol microemulsion photostability and protective effect against UV induced oxidative stress

2017 ◽  
Vol 67 (2) ◽  
pp. 247-256 ◽  
Author(s):  
Vaida Juškaitė ◽  
Kristina Ramanauskienė ◽  
Vitalis Briedis
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Activity ◽  
Ultraviolet Radiation ◽  
Uv Light ◽  
Biological Testing ◽  
Human Keratinocyte ◽  
Improved Stability ◽  
Rate Profile

Abstract Resveratrol is well known for its antioxidant activity and susceptibility to ultraviolet radiation. Development of formulations providing improved stability and relevant drug delivery of resveratrol is still a challenging task. The aim of this study was to determine protective characteristics of formulated microemulsions by evaluating photoisomerization of resveratrol and to investigate the effects of resveratrol on human keratinocyte cells under oxidative stress caused by ultraviolet radiation. Incorporation of resveratrol into microemulsions resulted in increased photostability of active compounds and the results demonstrated that photodegradation of resveratrol was significantly delayed. Results of biopharmaceutical evaluation in vitro demonstrated that up to 60 % of resveratrol was released from microemulsions within 6 hours under a constant release rate profile. In vivo biological testing confirmed the ability of resveratrol to protect cells from oxidative stress and to increase cell viability. It was concluded that microemulsions might be considered in the development of UV light sensitive compounds.

Hemolysis and the ultraviolet rays of the solar spectrum

PROTOPLASMA ◽  
1938 ◽  
Vol 31 (1) ◽  
pp. 207-220 ◽  
Author(s):  
George E. Davis ◽  
W. W. Lepeschein
Keyword(s):  
Solar Spectrum ◽  
Ultraviolet Rays
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