Acoustic emission frequency discrimination

In acoustic emission nondestructive testing, broadband frequency noise is distinguished from narrow banded acoustic emission signals, since the latter are valid events indicative of structural flaws in the material being examined. This is accomplished by separating out those signals which contain frequency components both within and beyond (either above or below) the range of valid acoustic emission events. Application to acoustic emission monitoring during nondestructive bond verification and proof loading of undensified tiles on the Space Shuttle Orbiter is considered

Seasonal variability in ichthyoplankton abundance and assemblage composition in the northern Gulf of Mexico off Alabama

Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes. Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and historic water temperatures, including a relatively long (June–October) “summer” period (water temperature >26°C). Fish egg abundance, total larval abundance, and larval taxonomic diversity were significantly related to water temperature (but not salinity), with peaks in the spring, spring–summer, and summer periods, respectively. Larvae collected during the survey represented 58 different families, of which engraulids, sciaenids, carangids, and clupeids were the most prominent. The most abundant taxa collected were unidentified engraulids (50%), sand seatrout (Cynoscion arenarius, 7.5%), Atlantic bumper (Chloroscombrus chrysurus, 5.4%), Atlantic croaker (Micropogonias undulatus, 4.4%), Gulf menhaden (Brevoortia patronus, 3.8%), and unidentified gobiids (3.6%). Larval concentrations for dominant taxa were highly variable between years, but the timing of seasonal occurrence for these taxa was relatively consistent. Documented increases in sea surface temperature on the Alabama shelf may have various implications for larval fish dynamics, as indicated by the presence of tropical larval forms (e.g., fistularids, labrids, scarids, and acanthurids) in our ichthyoplankton collections and in recent juvenile surveys of Alabama and northern Gulf of Mexico seagrass habitats

A HEDONIC APPROACH TO URBAN WETLAND VALUATION

Land Economics/Use,

The Theory of International Values

The problem of reciprocal demand, 582. — Advantage of variety of exports, 586. — Gains of large and small countries, 589. — Influence of demand for foreign products, 595. — Elasticity of demand, 600; of supply, 607. — The case of India, 610. — Long-run and short-run factors, 612. — Conclusion, 61

Protective Tariffs

https://digitalrepository.trincoll.edu/eastbooks/1182/thumbnail.jp

Evaluation of Betaine and Methionine Replacement for Improving Performance and Meat Quality for Broilers reared under Higher Temperature Conditions

4,096 broiler chicks were randomly allocated to 128 floor pens (32 birds/pen). 2,048 day-old male broilers were placed in the east end of a barn, and the following week 2,048 day-old male broilers were placed in the west end. At each placement day, half of the chicks were Cobb 500 and half were Ross 708, and each pen contained only one breed source. East end birds received coccidiostat in the feed, west end received coccidial vaccine, and each end was under separate environmental control. Eight diets contained two levels of coccidiostat (0, 1 lb./ton), methionine (deficient, adequate), and betaine (0, 2 lb./ton). Live weights were measured at days 0, 15, 31, 42 and 56. Cocci scoring was performed on day 22, ammonia flux was measured on day 36, and paw scoring was performed on days 42 and 56. Processing occurred on days 43 (5 birds/pen) and 57 (5 birds/pen). There were no significant differences between treatments in live weights for days 15, 31, 42, or 56. Day 42 paw scores for birds fed betaine + deficient methionine were significantly lower than other treatments, for Cobb Treatments 3 and 7, and for Ross Treatment 3. Birds in the west end had no cocci lesions, while the east did. Ross birds receiving coccidiosis-vaccine, fed betaine + reduced methionine had lower ammonia flux than Ross birds receiving either coccidiostat, fed no betaine + reduced methionine or Ross birds receiving coccidiosis-vaccine, fed betaine + adequate methionine. At day 57, Cobb birds fed betaine + reduced methionine had significantly higher breast and tender weights than all other Cobb birds, while Ross birds fed reduced methionine + no betaine had higher wing weights than any Ross birds receiving betaine. These findings indicate betaine supplementation can act to partially spare methionine. Betaine supplementation was also shown to decrease single-day heat-related mortality and also affect processing performance in broilers reared to heavy weights

Frank P. Graham to Professor James Wesley Silver, undated

Personal correspondenc

Peptic ulcer

The probable explanation of the development of a chronic peptic ulcer is that there is a lowering of local vitality. Important amongst numerous predisposing causes for this are faulty diet and nervous strain. Described types of organisms either attack the stomach and duodenum before such a devitilisation or more likely after it. The acid of the stomach tends to keep the ulcer open and to counteract a tendency for spontaneous cure. As Judd has truly remarked, "The final word concerning (the pathogenesis of) gastric and duodenal ulcer has not been spoken". Diagnosis rests particularly on two considerations. The first consideration is that following a careful clinical examination where especial note is made of the history. The second is a consideration of an X-ray examination. When operation has been advised or a post-mortem has been made, the excellence of modern radiology is proved, I have no regrets for basing my diagnosis so essentially on this ancillary science. Claims that a proper etiological basis had been found, led to the administration of histidine. Its use has been very doubtful, if not useless. A recent successful treatment of haematemesls has been described. The mortality rate is not high. The future health and working capacity of the individual is frequently impaired. Gastric acidity must be neutralised or buffered. Thus diet, alkalies and buffering agents are necessary. A reasonable proportion of cases does well. Relapses are likely in the present state of our knowledge. Routine treatments are useful. Physicians and Surgeons are co-operating to obtain a higher proportion of cures. There must, however, be a decided change from general treatment of the disease, to the individual study of the patient, and his circumstances