scholarly journals Photodegradation of Timber of Three Hardwood Species Caused by Different Light Sources

2012 ◽  
Vol 8 (1) ◽  
pp. 145-156 ◽  
Author(s):  
László Tolvaj ◽  
Dénes Varga
Keyword(s):  
Black Locust ◽  
Irradiation Time ◽  
Colour Change ◽  
Chemical Components ◽  
Mercury Vapour ◽  
Extractive Content ◽  
Xenon Lamp ◽  
Light Sources ◽  
Colour Measurements ◽  
Mercury Vapour Lamp

Abstract - In this study, resistance of black locust, beech and poplar wood to photodegradation was tested, applying sunlight, a xenon lamp and a mercury vapour lamp. The irradiation time was 200 hours for sunlight and the xenon light and 20 hours for the mercury light. The changes were monitored by colour measurements and infrared spectroscopy. The colour change of black locust was more intensive at the beginning of the irradiation than that of the beech and poplar. The degradation of aromatic structure of lignin (absorbing at 1510 and 1596 cm-1) in black locust was minor compared to the same changes of beech and poplar during the first 10 hours. The mercury lamp induced more intensive changes both in colour and in infrared spectrum than the other two light sources. The results show that the high extractive content of black locust absorbs a considerable amount of light radiation protecting the main chemical components of wood.

scholarly journals Testing the Photostability of Acetylated and Boiled Linseed Oil-coated Common Hornbeam (Carpinus betulus L.) Wood

2017 ◽  
Vol 13 (1) ◽  
pp. 81-94
Author(s):  
Fanni Fodor ◽  
Róbert Németh
Keyword(s):  
Artificial Aging ◽  
Linseed Oil ◽  
Colour Change ◽  
Ftir Spectra ◽  
Mercury Vapour ◽  
Colour Stability ◽  
Carpinus Betulus ◽  
Irradiation Test ◽  
Mercury Vapour Lamp ◽  
Weather Resistance

AbstractIn this study, the effect of acetylation and coating with boiled linseed oil was evaluated concerning the photodegradation of common hornbeam wood (Carpinus betulusL.). To measure colour stability, a 10-month-long outdoor weather resistance test without soil contact was performed as well as artificial aging using a 200 hour mercury-vapour lamp irradiation test. The measurements were done on hornbeam, acetylated hornbeam, boiled linseed oil-treated hornbeam, and acetylated and boiled linseed oil-treated hornbeam samples. The control and treated samples’ colour change was determined by comparing them to the original colour in all cases. The photodegradation process was examined with Fourier Transform Infrared (FTIR) spectra. Acetylated hornbeam was less prone to crack, but the modification did not hinder the fading and greying caused by UV irradiation. Coating the samples with boiled linseed oil decreased the rate of colour change and cracking. The photodegradation of lignin was confirmed by the FTIR spectra.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.

scholarly journals Photocatalytic Performance of ZnO: Al Films under Different Light Sources

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Prashant Pradhan ◽  
Juan Carlos Alonso ◽  
Monserrat Bizarro
Keyword(s):  
White Light ◽  
Irradiation Time ◽  
Zno Films ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Very High ◽  
High Degradation Rate

ZnO and Al doped ZnO films were produced by spray pyrolysis. The films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-vis spectroscopy, and photoluminescence. Their photocatalytic activity was evaluated by the decomposition of the methyl orange dye using different light sources: ultraviolet light, artificial white light, and direct sunlight. The films were also tested under darkness for comparison. The ZnO films were able to degrade the test pollutant under UV and sunlight in more than a 60% after 180 min of irradiation and a scarce degradation was obtained using white light. However, the Al doped ZnO films presented a very high degradation rate not only under UV and sunlight (100% degradation), but also under white light (90% degradation after the same irradiation time). An unexpected high degradation was also obtained in the dark, which indicates that a nonphotonic process is taking place parallel to the photocatalytic process. This can be due to the extra electrons—provided by the aluminum atoms—that migrate to the surface and produce radicals favoring the decomposition process even in the dark. The high activity achieved by the ZnO: Al films under natural conditions can be potentially applied to water treatment processes.

scholarly journals Intercalibration of different light-traps and bulbs used in moth monitoring in northern Europe

1998 ◽  
Vol 9 (1) ◽  
pp. 37-51 ◽  
Author(s):  
Reima Leinonen ◽  
Guy Söderman ◽  
Juhani Itämies ◽  
Seppo Rytkönen ◽  
Ilpo Rutanen
Keyword(s):  
The Other ◽  
Northern Europe ◽  
Mercury Vapour ◽  
Light Traps ◽  
Mercury Vapour Lamp ◽  
Species Being ◽  
Tungsten Lamp

Four different combinations of light-traps and bulbs were tested during the summer 1996 in Kainuu, northern Finland: a Jalas model with a 160-W (J/160W) blended light lamp or a 125-W (J/125W) mercury vapour lamp, a Ryrholm trap with a 125-W (R/125W) mercury vapour lamp and a Rothamsted trap with a 200-W tungsten lamp (G/200W). The traps were rotated between four sites every night, but were kept in the same position for the fifth night in order to prevent the possible influence of moonlight. The longest distance between the traps was 150m, and there was no direct visibility between any of them. Three orders were inspected, i.e. Lepidoptera, Coleoptera and Hemiptera, the total numbers of individuals and species being as follows: 20857/425, 862/101 and 1868/58. G/200W collected significantly fewer moths than the other traps. In some cases, J/125W collected significantly more moths and less species than the J/160W design. The R/125W design collected significantly more species than the J/160W design. Similar differences in the effectiveness of the lamps and traps were found in the case of Coleoptera and Hemiptera. Alpha diversities showed the same trend.

Photorearrangement of 2-cyanobicyclo[2.2.1]hept-2-ene. Observation of 1,2- and 1,3-sigmatropic shifts

1982 ◽  
Vol 60 (13) ◽  
pp. 1657-1663 ◽  
Author(s):  
Ikbal A. Akhtar ◽  
John J. McCullough ◽  
Susan Vaitekunas ◽  
Romolo Faggiani ◽  
Colin J. L. Lock
Keyword(s):  
Single Crystals ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Major Product ◽  
Molecular Structures ◽  
Lithium Aluminum ◽  
Mercury Vapour ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Mercury Vapour Lamp

Irradiation of 2-cyanobicyclo[2.2.1]hept-2-ene (2-cyanonorbornene, 4) in hexane, with the full arc of a mercury vapour lamp, gives the rearrangement products 1-cyanobicyclo[4.1.0]hept-2-ene 5 and 7-cyanotricyclo[4.1.0.03.7]heptane 6 in the ratio 20:1. These products were separated by preparative vpc. The structure of the major product 5 was determined by single crystal X-ray analysis. Reduction of 5 with lithium aluminum hydride gave the corresponding primary amine, which was converted to the p-bromobenzenesulfonamide 9, mp 150–151 °C, which gave single crystals from ethanol–water. The crystal and molecular structures are described. The minor product 6 was hydrogenated to give 7-cyanobicyclo[2.2. 1]heptane. Formation of 5 and 6 may involve concerted σ2s + π2s and σ2a + π2a processes respectively, which are photochemically allowed.

scholarly journals Physical and Mechanical Properties of Ammonia-Treated Black Locust Wood

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 377 ◽  
Author(s):  
Mariana Domnica Stanciu ◽  
Daniela Sova ◽  
Adriana Savin ◽  
Nicolae Ilias ◽  
Galina A. Gorbacheva
Keyword(s):  
Mechanical Properties ◽  
Black Locust ◽  
Loss Modulus ◽  
Colour Change ◽  
Treated Wood ◽  
Physical And Mechanical Properties ◽  
Mechanical Analysis ◽  
Modulus Of Rupture ◽  
Elastic Behaviour ◽  
Control Samples

Because of the uneven colour of black locust wood, different technologies are used to change the colour, the bestknown being chemical and thermal treatments. Some of them affect the mechanical properties of wood, such as elasticity modulus, strength, durability. This study aims to compare the physical and mechanical properties of black locust wood control samples and treated wood samples with ammonia hydroxide, in terms of density profile, colour values (CIE L*, a*, b*), mechanical properties of samples subjected to static bending, viscous-elastic properties (storage modulus (E’), loss modulus (E”) and damping (tanδ)). Two types of ammonia-fuming treatment were applied on samples: first treatment T1-5% concentration of ammonia hydroxide for 30 days; second treatment T2-10% concentration for 60 days. The results highlighted the following aspects: the overall colour change in the case of the second treatment is 27% in comparison with 7% recorded for the control samples; the lightness and yellowness values are the most affected by the second ammonia treatment of black locust wood. The density increased with almost 20% due to ammonium fuming (10% concentration/60 days); in case of static bending, the elastic modulus (MOE) tends to decrease with increasing the exposure time to ammonium, but the modulus of rupture (MOR) increases with almost 17% and the breaking force increases too, with almost 41%. In the case of dynamic mechanical analysis, the temperature leads to different viscous-elastic behaviour of each type of samples.

scholarly journals Usefulness of selected methods of colour change measurement for pork quality assessment

2011 ◽  
Vol 29 (No. 3) ◽  
pp. 212-218 ◽  
Author(s):  
T. Karamucki ◽  
J. Gardzielewska ◽  
A. Rybarczyk ◽  
M. Jakubowska ◽  
W. Natalczyk-Szymkowska
Keyword(s):  
Quality Assessment ◽  
Meat Quality ◽  
Colour Change ◽  
Industrial Process ◽  
Chemical Components ◽  
Pork Quality ◽  
Before And After ◽  
Longissimus Lumborum ◽  
Colour Parameters ◽  
Meat Colour

A few selected methods of the meat colour change determination were compared with regard to their usefulness in the assessment of the quality of minced pork. The study was carried out on 128 samples of the muscle longissimus lumborum, taken from 128 carcasses weighing 70&ndash;105 kg (equal number of both sexes &ndash; 64), obtained from pigs slaughtered in an industrial process line. The relationships were determined between the meat quality traits (concentrations of basic chemical components in the meat, colour, sensory analysis of wateriness and firmness, WHC and pH<sub>u</sub>), and the changes in colour parameters measured in CIELAB and CIELCh scales, total colour change (&Delta;E*), and the changes determined by Karamucki using the modified Kortz method. It was found that the most useful method for the quality assessment was the Kortz method modified by Karamucki, used to determine the stability of the meat colour (expressed as % colour change) and based on the measurements of absorbance at wavelengths 580 nm and 630 nm, before and after the change of colour. Out of the meat colour parameters, the most useful for assessing the meat quality were the changes in redness (a*) &ndash; CIELAB scale, and hue angle h&ordm; &ndash; CIELCh scale. The changes in colour determined by the aforementioned methods were a better indicator of the pork quality than the total colour change (&Delta;E*).

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