Study and Evaluation on Effect of Ultra-Violet (UV) Radiation on the Structural and Mechanical Properties of Talc filled Polypropylene Co-polymer (TFPP)

2013 ◽  
Vol 66 (3) ◽  
pp. 273-280 ◽  
Author(s):  
S. M. Kakani ◽  
S. S. Zadgaonkar ◽  
S. A. Pande ◽  
K. N. Pande ◽  
D. R. Peshwe
Keyword(s):  
Mechanical Properties ◽  
Uv Radiation ◽  
Ultra Violet

scholarly journals Extensive reduction of surface UV radiation since 1750 in world's populated regions

2009 ◽  
Vol 9 (20) ◽  
pp. 7737-7751 ◽  
Author(s):  
M. M. Kvalevåg ◽  
G. Myhre ◽  
C. E. Lund Myhre
Keyword(s):  
Uv Radiation ◽  
Correlation Coefficients ◽  
Ultra Violet ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Polar Regions ◽  
Ultra Violet Radiation ◽  
Wide Range ◽  
Extensive Surface ◽  
Year 2000

Abstract. Human activity influences a wide range of components that affect the surface UV radiation levels, among them ozone at high latitudes. We calculate the effect of human-induced changes in the surface erythemally weighted ultra-violet radiation (UV-E) since 1750. We compare results from a radiative transfer model to surface UV-E radiation for year 2000 derived by satellite observations (from Total Ozone Mapping Spectroradiometer) and to ground based measurements at 14 sites. The model correlates well with the observations; the correlation coefficients are 0.97 and 0.98 for satellite and ground based measurements, respectively. In addition to the effect of changes in ozone, we also investigate the effect of changes in SO2, NO2, the direct and indirect effects of aerosols, albedo changes and aviation-induced contrails and cirrus. The results show an increase of surface UV-E in polar regions, most strongly in the Southern Hemisphere. Furthermore, our study also shows an extensive surface UV-E reduction over most land areas; a reduction up to 20% since 1750 is found in some industrialized regions. This reduction in UV-E over the industrial period is particularly large in highly populated regions.

Dynamic Mechanical Analysis of Bio-Based and Synthetic Petroleum Based Polymer Foams with Powder Type Organic Filler at Prolonged Ultra-Violet Exposure

2020 ◽  
Vol 01 (01) ◽  
Author(s):  
M A Zulhakimie ◽  
◽  
Anika Zafiah M. Rus ◽  
N S S Sulong ◽  
A Syah Z A ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Polymer ◽  
Loss Modulus ◽  
Ultra Violet ◽  
Mechanical Analysis ◽  
Uv Exposure ◽  
Polymer Foams ◽  
Polymer Foam ◽  
Powder Filler ◽  
Tan Δ

Wood powder filler applied to the bio-based and epoxy polymer foams has the potential to reinforce the polymer foam structure. The 'Meranti' wood filler type was used as the filler in this analysis. In order to observe the pore size of each sample when exposed to different hours of UV exposure using optical microscopy (OM), this study was made.This analysis was conducted to compare the mechanical properties of each sample with different filler ratios of 0 wt%, 5 wt%, 10 wt%, 15wt% and 20 wt% at different UV exposure hours, which is 0 hour to 6000 hours with a 2000 hour rapid increase. Using the DMA Q800 TA unit, the mechanical properties were studied. In order to obtain the product of their mechanical properties, samples having a scale of 40 x 10 x 5 mm were clamped into the machine. The results will show the value of tan δ, loss modulus and storage modulus from the DMA test.The tan δ value shows that the high tanδvalue will be produced by the higher ratio filler. In contrast to bio-based polymer foams, epoxy polymer foams with powder fillers have the highest tan δ value. It shows that the higher filler ratio can be reported with the lower tan δ value. As the filler ratio filler in the polymer foams increased, the consequence of storage and loss modulus was found to increase. The greater the modulus of loss and the modulus of storage, the lower the temperature. As energy is lost as heat during UV irradiation exposure, bio-based polymer foams with a high powder filler ratio can dissipate more energy.

ULTRA VIOLET DETECTION SENSORS

2006 ◽  
Vol 16 (02) ◽  
pp. 583-588
Author(s):  
Vahé NERGUIZIAN ◽  
Mustapha RAFAF ◽  
Muthukumaran PACKIRISAMY ◽  
Ion STIHARU
Keyword(s):  
Human Skin ◽  
Uv Radiation ◽  
Radiation Risk ◽  
Ultra Violet ◽  
Visual Monitoring ◽  
Ultra Violet Light ◽  
Actuation Mechanism ◽  
Violet Light ◽  
Uv Sensors ◽  
Chemical Material

This article presents an innovative and creative approach to detect harmful level of Ultra Violet light on human skin. Different commercial UV sensors are evaluated for comparison. The comparison is made for performance, cost and dimension. The proposed affordable UV sensor solutions are presented using chemical and MEMS/MOEMS technologies. The UV dynamic sensor detects the harmful level of UV and informs the user about the eventual UV radiation risk. The proposed two solutions consider chemical material for UV detection and different actuation mechanism to inform the UV harmful level to the user. These sensors are non disposable and are packaged for visual monitoring (without battery) and acoustic operation (using a battery).

Plasma agriculture based on quantitative monitoring of reactions between fungal cells and atmospheric-pressure plasmas

2012 ◽  
Vol 1469 ◽  
Author(s):  
Masafumi Ito ◽  
Takayuki Ohta ◽  
Keigo Takeda
Keyword(s):  
Uv Radiation ◽  
Absorption Spectroscopy ◽  
Ground State ◽  
Atmospheric Pressure ◽  
Atomic Oxygen ◽  
Fungal Spores ◽  
Ultra Violet ◽  
High Density ◽  
Inactivation Rate ◽  
The Absolute

ABSTRACTA high-density non-equilibrium atmospheric pressure plasma (NEAPP) applied for inactivating fungal spores of P. digitatum is introduced as an environmentally safe and rapid-inactivation method. The contributions of ozone, ultra violet (UV) radiation and ground-state atomic oxygen in the NEAPP on the inactivation of the spores are evaluated using colony count method.The absolute densities of ozone were measured by using ultraviolet absorption spectroscopy. The ozone density increased from 2 to 8 ppm with an increase in the distance from the plasma source, while the inactivation rate decreased. The inactivation rate of plasma was evaluated to be thousand times higher than that of an ozone generator using the integrated number density of ozone. In addition, it was clarified that the contribution of UV radiation to inactivation was not dominant for P. digitatum inactivation by NEAPP by filtering the active species using quartz plate. From these results, we can speculate that the inactivation efficiency of reactive oxygen species (ROS) will be larger than those of others.In order to investigate the effect of ground-state atomic oxygen as one of ROS, the inactivation of P. digitatum spores using an oxygen radical source that employs a high-density atmospheric-pressure O2/Ar plasma. The absolute O density was measured to be 1.4×1014 and 1.5×1015 cm–3 using vacuum ultra violet absorption spectroscopy (VUVAS) using a microdischarge hollow cathode lamp. The behaviors of the O densities as a function of O2/(Ar+O2) mixture flow rate ratio correspond to that of the inactivation rate. This result indicates that ground-state atomic oxygen is concluded to be the dominant species that causes inactivation.

scholarly journals INFLUENCE OF ENVIRONMENTAL FACTORS ON PHYSICAL-MECHANICAL PROPERTIES OF POLYDIMETHYL ETHER OF NORBORENE -2;3-DICARBOXYLIC ACID

2017 ◽  
Vol 60 (5) ◽  
pp. 68 ◽  
Author(s):  
Galina S. Bozhenkova ◽  
Alexandra N. Tarakanovskaya ◽  
Oksana D. Tarnovskaya ◽  
Roman V. Ashirov
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Hydrochloric Acid ◽  
Environmental Factors ◽  
Dicarboxylic Acid ◽  
Uv Radiation ◽  
Accelerated Aging ◽  
The Impact

The article is devoted to the production of polymer by metathesis ring-opening polymerization under the influence of ruthenium initiator of type of Hoveyda-Grubbs II generation. The monomer used the mixture of dimethyl ether norbornene-2;3-dicarboxylic acid. The monomer was prepared by the Diels-Alder reaction of dicyclopentadiene and dimethyl maleate. The polymer was prepared in bulk of the monomer mixture. In this paper we have studied the physical and mechanical properties polydimethyl ether of norbornene-2;3-dicarboxylic acid; and assessed the impact of environmental factors on the change in properties of the polymer. As environmental factors; light; UV radiation; water; 0.1 M hydrochloric acid were applied; and accelerated aging conditions; which were held in a climate chamber. During performance we found that maintaining the polymer samples in the UV light chamber led to the slight increase in flexural modulus. In contrast; the polymer storage in water and in a hydrochloric acid solution for two months resulted in a slight decrease in the modulus of elasticity in bending index. These factors did not affect the change in the glass transition temperature of the polymer. Under the conditions of accelerated aging conducted for 1; 2 and 6 days after two cycles we observed the drop in modulus for bending of 8.5%; after 6 cycles of 13%. The glass transition temperature of polydimethyl ether of norbornene-2;3-dicarboxylic acid after 6 cycles decreased by only 3.4% in the climatic chamber. Studies have shown that the resulting polymer is resistant to water; hydrochloric acid; light and UV radiation; as well as it saves properties at a sufficient level for operation at conditions of accelerated aging. It should be noted that the tested polymer was prepared without additives; stabilizers and antioxidants. The proposed polymer can be used as a structural material for machine parts; including bulky.For citation:Bozhenkova G.S.; Tarakanovskaya A.N.; Tarnovskaya O.D.; Ashirov R.V. Influence of environmental factors on physical-mechanical properties of polydimethyl ether of norborene -2;3-dicarboxylic acid. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 5. P. 68-73

scholarly journals Effects of Thermal Cycle and Ultraviolet Radiation on 3D Printed Carbon Fiber/Polyether Ether Ketone Ablator

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 95
Author(s):  
Farhan Abdullah ◽  
Kei-ichi Okuyama ◽  
Akito Morimitsu ◽  
Naofumi Yamagata
Keyword(s):  
Mechanical Properties ◽  
Carbon Fiber ◽  
Uv Radiation ◽  
Thermal Cycle ◽  
Temperature Behavior ◽  
Heat Shield ◽  
Polyether Ether Ketone ◽  
Peek Composite ◽  
3D Printed ◽  
Ether Ketone

The extreme heating environment during re-entry requires an efficient heat shield to protect a spacecraft. The current method of manufacturing a heat shield is labor intensive. The application of 3D printing can reduce cost and manufacturing time and improve the quality of a heat shield. A 3D printed carbon fiber/polyether ether ketone (CF/PEEK) composite was proposed as a heat shield material. The aim was to develop a heat shield and the structural member as a single structure while maintaining the necessary recession resistance. Test samples were exposed to thermal cycles and ultraviolet (UV) radiation environment. Subsequently, a tensile test was performed to evaluate the effect of thermal cycle and UV radiation on the mechanical properties. The sample’s recession performance and temperature behavior were evaluated using an arc heated wind tunnel. Exposure to thermal cycle and UV radiation have limited effect on the mechanical properties, recession behavior and temperature behavior of 3D CF/PEEK. Results from the arc heating test showed an expansion of the sample surface and better recession resistance than other existing ablator materials. Overall, 3D CF/PEEK has excellent recession resistance while maintaining mechanical properties when exposed to high temperature, thermal cycle and UV radiation.

scholarly journals Vegetable Tannin as a Sustainable UV Stabilizer for Polyurethane Foams

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 480 ◽  
Author(s):  
Maria Oliviero ◽  
Mariamelia Stanzione ◽  
Marco D’Auria ◽  
Luigi Sorrentino ◽  
Salvatore Iannace ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Uv Radiation ◽  
Polyurethane Foams ◽  
Accelerated Weathering ◽  
Polyphenolic Compound ◽  
Uv Treatment ◽  
Blowing Agent ◽  
Performance Change ◽  
Urethane Linkage ◽  
Vegetable Tannin

A vegetable tannin, a flavonoid-type natural polyphenolic compound, was used to promote the stabilization of polyurethane foams against UV radiation. Several polyurethane foams were synthesized by using an isocyanate, and a mixture of ethoxylated cocoalkyl amine and vegetable tannin. The content of vegetable tannin was varied from 0 to 40 wt %. The effects of tannin and water (used as a blowing agent) on the foaming kinetics and cellular morphology of foams were investigated. Samples were subjected to accelerated weathering under UV radiation for 3 to 24 h, and FTIR and DMA analyses were conducted to assess the performance change. The former analysis revealed a strong inhibiting effect of tannin on urethane linkage degradation during the UV treatment. The mechanical properties were significantly affected by the addition of tannin. The capability of the foams to withstand UV radiation was dependent on the amount of tannin. At tannin contents higher than 20%, the decrease in mechanical properties under UV irradiation was almost avoided.

scholarly journals UV Irradiated Graphene-Based Nanocomposites: Change in the Mechanical Properties by Local HarmoniX Atomic Force Microscopy Detection

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 962 ◽  
Author(s):  
Liberata Guadagno ◽  
Carlo Naddeo ◽  
Marialuigia Raimondo ◽  
Vito Speranza ◽  
Roberto Pantani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Mechanical Stability ◽  
Uv Light ◽  
Ultra Violet ◽  
Graphene Nanoplatelets ◽  
Free Standing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Acquisition Mode

Epoxy based coatings are susceptible to ultra violet (UV) damage and their durability can be significantly reduced in outdoor environments. This paper highlights a relevant property of graphene-based nanoparticles: Graphene Nanoplatelets (GNPs) incorporated in an epoxy-based free-standing film determine a strong decrease of the mechanical damages caused by UV irradiation. The effects of UV light on the morphology and mechanical properties of the solidified nanocharged epoxy films are investigated by Atomic Force Microscopy (AFM), in the acquisition mode “HarmoniX.” Nanometric-resolved maps of the mechanical properties of the multi-phase material evidence that the incorporation of low percentages, between 0.1% and 1.0% by weight, of graphene nanoplatelets (GNPs) in the polymeric film causes a relevant enhancement in the mechanical stability of the irradiated films. The beneficial effect progressively increases with increasing GNP percentage. The paper also highlights the potentiality of AFM microscopy, in the acquisition mode “HarmoniX” for studying multiphase polymeric systems.

BIOACTIVE ASSESSMENT AND BACTERIA TEST FOR THE VARIED DEGREES OF ULTRA-VIOLET RADIATION ONTO THE COLLAGEN-IMMOBILIZED POLYPROPYLENE NON-WOVEN FABRIC

2002 ◽  
Vol 14 (01) ◽  
pp. 20-30 ◽  
Author(s):  
JIUNN-DER LIAO ◽  
YU-CHANG TYAN
Keyword(s):  
Red Blood Cells ◽  
Human Plasma ◽  
Uv Radiation ◽  
Blood Cells ◽  
Ultra Violet ◽  
Woven Fabric ◽  
Plate Count ◽  
Fibrinogen Concentration ◽  
Thrombin Time ◽  
Chemical Structures

Exposure to ultra-violet (UV)-C radiation is a frequently used method to prevent bacteria from invasion of blood-contact biomedical products. Potential damage induced by UV radiation to collagen is of concern due to the decay of bioactivity, considerably correlated with structural alterations. Current investigation indicates to the collagen-immobilized non-woven polypropylene (PP) fabrics with sample temperature ca. 4 °C; the samples are then exposed to UV-254 nm radiation for different time intervals. Using Fourier-Transformed Infrared with Attenuated Total Reflection (FTIR-ATR) and XPS (X-ray Photoelectron Spectroscopy), we examine the chemical structures of samples with different treatments. Blood-clotting effects on the modified samples are assessed by activated partial thromboplastin time, thrombin time, and fibrinogen concentration tests. By means of cell counter and Scanning Electron Microscopy we count red blood cells and platelets adhesion in the modified porous matrix. Applying standard plate count for bacteria tests, E. coli, Bacillus stearothermophilus, Staph. aureus, P. aeruginosa, and Candida albieans are applied. For human plasma incubated samples of various intervals of UV-254 nm radiation, fibrinogen concentration decreases in human plasma, while platelets and red blood cells adhesions increase before UV radiation. The required time for thrombination shows significant change for UV exposure of less than 20 hrs (α = 0.05). Surface analyses indicate that the decrease of R-COOH (derivated from grafted-pAAc or decarboxylation of collagen), amides degradation (broken–NH), and phenylalanine scission (terminated by −OH, tyrosine formation) may gradually damage collagen by increasing the intervals of UV radiation. The XPS measurements of C 1s core levels at 288.1 eV (O=C-NH) and at 289.3 eV (O=C-O) illustrate significant decreases of intensity after radiation time ca. 44 hrs. It is clear that UV-254 nm radiation exposure for ca. 20 hrs has the potential impact to moderate the bioactivities of collagen and therefore act as a vital factor to accelerate bio-degradation. Bacteria test also supports that around 20 hrs of UV radiation, no bacteria clone formation is found on the immobilized collagen. However, the relation between eventual bioactivity of immobilized collagen after UV radiation and the capability of bacteria proliferation should be measured.

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