Potential solar radiation at H.J. Andrews Experimental Forest, Oregon

EXTRACT (SEE PDF FOR FULL ABSTRACT): Potential (clear-sky) radiation receipt is modeled for the slopes of the H.J. Andrews Experimental Forest Long-Term Ecological Research site in the foothills of the southern Cascade mountains of central Oregon. The modeling method developed by Williams is selected and applied to the forest area for the times of the solstices and equinox as well as mid-month times in January, February, April, and May in order to completely characterize the seasonal change of potential radiation at the location. ... It seems that Lookout Creek approximately divides the Andrews Forest into an area of relatively high potential radiation to the north of the creek and relatively lower potential radiation values to the south of the creek. Potential radiation values seem to be associated with the Andrews GIS data layers of debris flows and predominant tree species zones.

Topography and substratum of the Jaffna Lagoon

Little is known of the topography and substratum of the lagoon and estuarine waters of Ceylon. This knowledge is important in understanding the fisheries and its effective management. Bottom topography of the sea is usually given in the British Admiralty charts and other navigational charts. Some indications of the different types of bottom of the continental shelf are also given. The information given in these charts is inadequate to understand the fisheries of lagoons and estuarine waters. Jaffna lagoon is such a body of water situated in Northern Province of Ceylon. Knowledge of the bottom topography of this lagoon was found to be necessary in revising the fishing regulations in force in the Northern Province of Ceylon, with special reference to the use of the fishing gear, Sirahu Valai. As such a preliminary survey of the topography and type of the bottom of Jaffna lagoon was undertaken.

High frequency multimode radiation from ducts with flow

Multimode sound radiation from hard-walled semi-infinite ducts with uniform subsonic flow is investigated theoretically. An analytic expression, valid in the high frequency limit, is derived for the multimode directivity function in the forward arc for a general family of mode distribution functions. The multimode directivity depends on the amplitude and directivity function of each individual mode. The amplitude of each mode is expressed as a function of cut-off ratio for a uniform distribution of incoherent monopoles, a uniform distribution of incoherent axial dipoles and for equal power per mode. The modes' directivity functions are obtained analytically by applying a Lorentz transformation to the zero flow solution. The analytic formula for the multimode directivity with flow is derived assuming total transmission of power at the open-end of the duct. This formula is compared to the exact numerical result for an unflanged duct, computed utilizing a Wiener-Hopf solution. The agreement is shown to be excellent. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Effects of gamma radiation on nutritional and microbial quality of Pampus chinensis (Euphrasen 1788)

To evaluate the efficiency of gamma radiation in combination with low temperature Chinese pomfret, Pampus chinensis were preserved by the treatment of different doses of gamma radiation (3, 5 and 8 KGy) at freezing temperature (-20°C) during 90 days of storage period. Quality assessments for fish were carried out at an interval of 15 days during the storage period. Quality assessments were done by organoleptic, chemical (Total Volatile Nitrogen, TVN and Trimethylamine, TMA) and microbiological (Total Bacterial Count, TBC and Total Mould Count, TMC) evaluation. From the analysis of all parameters, maximum shelf-life was observed for irradiated (8 KGy) sample. It remained acceptable up to 75 days and that was the highest duration among 4 types of samples.

Studies on radiation pasteurisation of medium fatty fish 1. Control of radiation induced oxidative changes in white pomfret (Stromateus cinereus) by vacuum packaging

Marked differences were observed in proximate biochemical compositions of the skin and muscle of white pomfret. The skin showed comparatively higher content of extractable lipids and was more susceptible to radiation-induced oxidative changes like development of rancid odours and yellow discolouration than the muscle. Irradiation of skin samples under vacuum suppressed these changes. The present paper also reports on the efficacy of vacuum packaging in controlling oxidative rancidity and yellow discolouration in white pomfret skin subjected to irradiation and subsequent storage at 0-2°C.

Studies on radiation pasteurisation of medium fatty fish 3. Storage properties of white pomfret (Stromateus cinereus) fillets

White pomfret fillets packed under aerobic conditions had a limited shelf life of 8 days as against 10 days for samples packed under vacuum and stored at 0-2°C. Irradiation and subsequent storage of the fillets under vacuum at 0-2°C exhibited shelf lives of 30, 50 and 60 days for radiation doses of 0.1, 0.3 and 0.5 Mrad respectively in contrast to aerobically packed fillets which showed only 20, 35 and 50 days of storage life for the same levels of radiation doses and developed yellow discolouration and rancid odours.

Studies on radiation pasteurisation of medium fatty fish 2. Precursors of yellow discolouration in irradiated white pomfret (Stromateus cinereus)

Triglycerides, phospholipids and sarcoplasmic proteins fractions of white pomfret produced considerable amounts of thiobarbituric acid reactive substances (TBRS) on irradiation. Incubation of malonaldehyde with pomfret skin under aseptic conditions developed yellow pigmentation of the skin tissues, similar in spectral characteristics to those produced on irradiation of the skin.

Commercial studies on radiation preservation of fish and shell-fish in Canada

The author describes work being undertaken at the Fisheries Research Board of Canada's Laboratory at Halifax (Nova Scotia). These studies relate particularly to the irradiation of fish and shellfish for storage, and bacterial analysis of irradiated products.

Tensile strength properties of polyethylene netting twines under exposure to out-door and artificial UV radiation

Photodegradation of three types of polyethylene twines namely, polyethylene fibrillated tape twine, polyethylene flat tape twine and polyethylene monofilament twines were studied by exposing them to sunlight and artificial UV radiation. The percentage residual strength varied in the samples, the monofilament with the highest residual strength followed by fibrillated tape twine and flat tape twine. A plot of the difference between the breaking strengths of the fibrillated tape twine and the mono filament twines against any given period of exposure exhibited a linear relationship

A mitogenomic perspective on the ancient, rapid radiation in the Galliformes with an emphasis on the Phasianidae

Background: The Galliformes is a well-known and widely distributed Order in Aves. The phylogenetic relationships of galliform birds, especially the turkeys, grouse, chickens, quails, and pheasants, have been studied intensively, likely because of their close association with humans. Despite extensive studies, convergent morphological evolution and rapid radiation have resulted in conflicting hypotheses of phylogenetic relationships. Many internal nodes have remained ambiguous. Results: We analyzed the complete mitochondrial (mt) genomes from 34 galliform species, including 14 new mt genomes and 20 published mt genomes, and obtained a single, robust tree. Most of the internal branches were relatively short and the terminal branches long suggesting an ancient, rapid radiation. The Megapodiidae formed the sister group to all other galliforms, followed in sequence by the Cracidae, Odontophoridae and Numididae. The remaining clade included the Phasianidae, Tetraonidae and Meleagrididae. The genus Arborophila was the sister group of the remaining taxa followed by Polyplectron. This was followed by two major clades: ((((Gallus, Bambusicola) Francolinus) (Coturnix, Alectoris)) Pavo) and (((((((Chrysolophus, Phasianus) Lophura) Syrmaticus) Perdix) Pucrasia) (Meleagris, Bonasa)) ((Lophophorus, Tetraophasis) Tragopan))). Conclusions: The traditional hypothesis of monophyletic lineages of pheasants, partridges, peafowls and tragopans was not supported in this study. Mitogenomic analyses recovered robust phylogenetic relationships and suggested that the Galliformes formed a model group for the study of morphological and behavioral evolution.

Effects of gamma radiation and -20°C temperatures on the shelf life of Hilsa, Tenualosa ilisha (ham.-Buch. 1822)

The combined effect of radiation and refrigeration on the shelf life of hilsa, Tanualosa ilisha was studied by monitoring the microbiological, chemical and sensory changes of unirradiated and irradiated fish samples using low dose irradiation, doses of 300 krad, 600 krad and 900 krad. Irradiation (900 krad) dramatically reduced population of bacteria, namely total viable counts 48.850cfu per gm for unirradiated, 31.850cfu per gm and 19.600cfu per gm of 300 krad and 600 krad, respectively. The effect was more pronounced at the higher dose (900 krad), total viable count were 14.100cfu per gm. Another microbial indicator total mould counts (TMC) was 8.750cfu per gm, 6.350cfu per gm, and 19.600cfu per gm for 300 krad and 600 krad, respectively. The effect was more pronounced at the higher dose (900 krad) where total viable counts were 14,100cfu per gm. Total volatile nitrogen values increased slowly attaining a value of 101.02mgN per 100gm for unirradiated T. ilisha during refrigerated storage, whereas for irradiated fish, lower values of 71.13, 59.33 and 47.03mgN per 100gm muscle were recorded. Sensory evaluation showed a good correlation with bacterial populations on the basis of overall acceptability scores.