scholarly journals COMPARISON OF MODEL AND BEACH SCOUR PATTERNS

1970 ◽  
Vol 1 (12) ◽  
pp. 80
Author(s):  
John B. Herbich
Keyword(s):  
Gulf Coast ◽  
Wave Length ◽  
Laboratory Studies ◽  
Intermediate Type ◽  
Characteristic Parameters ◽  
Reflected Waves ◽  
Texas Gulf Coast ◽  
Laboratory Conditions ◽  
Set Up ◽  
Incident Waves

Artificial or natural barriers may be divided into two classes, those from which waves are reflected and those on which waves break In general, any intermediate type that gives a combination of reflection and breaking may set up severe erosive action of the beach m front of barriers When the reflected waves are superimposed on the incident waves a stationary spatial envelope of the combined incident and reflected waves is produced Previous laboratory studies indicated that the crests of the sand bed appear fairly closely under the nodes of the envelope and troughs of the scoured sand bed under the loops of the envelope The predominant scouring pattern had a spacing between crests equal to one-half the wave length Other studies by Keulegan and Shepard established characteristic parameters for bar and trough depth for laboratory conditions and for several field locations Their studies were compared with beach profiles taken along the Texas Gulf Coast.

Gradient-Zone Erosion in Seawater Solar Ponds

1997 ◽  
Vol 119 (1) ◽  
pp. 2-7 ◽  
Author(s):  
J. Shi ◽  
R. A. Hart ◽  
S. J. Kleis ◽  
R. B. Bannerot
Keyword(s):  
Gulf Coast ◽  
Operating Conditions ◽  
Experimental Program ◽  
Entrainment Rate ◽  
Laboratory Studies ◽  
Cold Temperatures ◽  
Gradient Zone ◽  
Solar Ponds ◽  
Texas Gulf Coast ◽  
Thermal Refuge

An experimental program has been conducted to examine the feasibility of using seawater solar ponds in mariculture operations along the Texas gulf coast to protect fish crops from the potentially lethal, cold temperatures experienced in outdoor ponds. Seawater solar ponds in the form of floating thermal refuge areas are proposed as a method for reducing the loss of heat from small sections of a pond. Gradient zone erosion under various ambient and operating conditions is examined. Comparisons with previous laboratory studies show a much lower entrainment rate in the natural environment. For conditions which are typical of those encountered in mariculture pond operation, the entrainment rate was found to depend only weakly on the Richardson number. For these conditions, a simple (linear) correlation of entrainment rate with wind speed was developed.

Involution and Cystic Transformation of the Thymus in the Bottlenose Dolphin, Tursiops truncatus

1994 ◽  
Vol 31 (6) ◽  
pp. 648-653 ◽  
Author(s):  
D. F. Cowan
Keyword(s):  
Body Size ◽  
Bottlenose Dolphin ◽  
Tursiops Truncatus ◽  
Squamous Epithelium ◽  
Gulf Coast ◽  
Bottlenose Dolphins ◽  
Adult Life ◽  
Lymphoid Cells ◽  
Texas Gulf Coast ◽  
Thymic Cysts

The thymus glands of 10 bottlenose dolphins, Tursiops truncatus, collected along the Texas Gulf coast were examined using standard histologic and immunocytochemical methods. The thymus gland of Tursiops persists into adult life, represented by medulla and progressively thinning cortex. A network of epithelial cells, including Hassal bodies, is demonstrable using polyclonal anti-cytokeratin antibody. The network condenses, with loss of lymphoid cells as involution progresses. Cysts arise within the condensed network. These cysts, found in eight of 10 animals, increase in number and size with increasing body size. Body size tends to reflect age. Thymic cysts typically have an irregular shape when small but tend to become spherical as they enlarge. Theey may be lined by squamous epithelium of variable thickness. Eventually, the cysts become macroscopic and filled with a colloidlike material and may largely replace the thymus, which may be identified by noncystic remnants adjacent to the cysts.

scholarly journals Toxicity of Imidacloprid and Diafenthiuron to Chrysoperla Carnea (Stephens) (Neuroptera: Chrysopidae) in the Laboratory Conditions

2009 ◽  
Vol 49 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Gnanadhas Preetha ◽  
Johnson Stanley ◽  
Thiagarajan Chandrasekaran ◽  
Sasthakutty Kuttalam
Keyword(s):  
Plant Protection ◽  
Larval Mortality ◽  
Plant Protection Products ◽  
Threshold Level ◽  
Adult Mortality ◽  
Recommended Dose ◽  
Chrysoperla Carnea ◽  
Laboratory Studies ◽  
Egg Mortality ◽  
Laboratory Conditions

Toxicity of Imidacloprid and Diafenthiuron toChrysoperla Carnea(Stephens) (Neuroptera: Chrysopidae) in the Laboratory ConditionsInsecticides are unavoidable in pest management programs especially when the pest crosses Econimic Threshold Level (ETL). Nevertheless, often the plant protection products kill the natural enemy population making the pest to resurge and thus demanding more sprays. Therefore, insecticides used in IPM programs should be selective enough to spare the beneficials. Laboratory studies were conducted to find out the toxicity of imidacloprid and diafenthiuron to the eggs, larvae and adults ofChrysoperla carnea.Imidacloprid at the recommended dose of 0.28 ml/l caused 15.38% egg mortality, 26.67 and 33.33% larval mortality by ingestion and contact, respectively and 50.00% adult mortality. The egg mortality was about 15.38% and larval mortality of 23.33% and adult mortality of 26.67% was caused by diafenthiuron. Based on the classification given by IOBC/WPRS working group on Pesticides and non-target invertebrates, both the insecticides were classified as harmless toC. carnea, since the recommended dose caused less than 50% mortality in the laboratory conditions.

scholarly journals Coralivoría del gasterópodo Jenneria pustulata (Ovulidae: Pediculariinae) en dos arrecifes coralinos del PNN isla Gorgona

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Mauro Giovanni Zucconi ◽  
Levy D. Obonaga ◽  
Edgardo Londoño-Cruz
Keyword(s):  
Coral Reefs ◽  
Coral Species ◽  
Size Structure ◽  
Coral Tissue ◽  
Laboratory Conditions ◽  
Set Up ◽  
Biological Dynamics ◽  
Colombian Pacific

Coral reefs are very important and highly biodiverse ecosystems that are exposed to various stressors, including biological ones, such as parasitism and corallivory – the direct consumption of coral tissue by a predator. Knowledge on the effects of corallivory on the coral reefs in the Colombian Pacific is poor. Therefore a study was set up to quantify the abundance of and the corallivory rate by the snail Jenneria pustulata in La Azufrada and Playa Blanca coral reefs (Gorgona Island, Colombia). Snails were manually sampled from the underside of Pocillopora sp. colonies and measured in situ to determine their size structure for each reef. To measure possible damage caused by corallivory, several snails were kept under controlled laboratory conditions for 24 h. Snail sizes and corallivory varied significantly between reefs (P=0.0001; P«0.001). Snails from Playa Blanca were larger than snails from La Azufrada, while corallivory was higher in La Azufrada than in Playa Blanca. Although corallivory rates by J. pustulata are smaller than rates reported for other predators in different coral species, it is recommended to continue this kind of investigations in order to increase the knowledge on biological dynamics of this species and to understand how they affect the reefs at Gorgona Island.

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