Progressive fracture of fiber composites

Refined models and procedures are described for determining progressive composite fracture in graphite/epoxy angleplied laminates. Lewis Research Center capabilities are utilized including the Real Time Ultrasonic C Scan (RUSCAN) experimental facility and the Composite Durability Structural Analysis (CODSTRAN) computer code. The CODSTRAN computer code is used to predict the fracture progression based on composite mechanics, finite element stress analysis, and fracture criteria modules. The RUSCAN facility, CODSTRAN computer code, and scanning electron microscope are used to determine durability and identify failure mechanisms in graphite/epoxy composites

Seabrook: A Case Study in Mismanagement

The Seabrook nuclear power plant construction project is an unqualified financial disaster. It simultaneously threatens its chief owner, the Public Service Co. of New Hampshire (PSNH) with bankruptcy and the company\u27s electricity customers with huge rate increases. The fifteen-year history of the project is reviewed to identify what went wrong? The review suggests that the basic problem has been mismanagement by both PSNH and by government regulators. A three-year regulatory imbroglio over the environmental effects of the plant\u27s cooling system was extremely costly in the mid-1970s. By the time this problem was belatedly resolved, the project had begun to outstrip the financial resources of its owners. These resources were seriously weakened by a political battle over how to pay for construction costs. By the end of the 1970s, the risks of proceeding with Seabrook were beginning to exceed the benefits. PSNH management, however, chose to accept these risks, in effect betting their company that the project could be completed. Underlying many of Seabrook\u27s problems are certain federal nuclear regulatory policies and practices whose roots go all the way back to the Eisenhower administration. These policies are also briefly reviewed

Study of the Remediation of Deficiencies in Auditory Perception

Author Institution: Kent City Schools; Department of Counseling and Special Education, University of AkronThe screening of 243 students from 10 kindergarten classes resulted in the identification of 39 children with perceptual deficiencies in the auditory channel. Auditory training procedures dictated by Lerner's definition of auditory perception were introduced into 5 kindergarten classes. Five no-treatment classes were included as control groups. Effects of the training program reported for these 39 subjects indicated growth at the meaningful level of language usage and improvement in the ability to analyze words. The effects of the auditory training program on reading readiness and self-concept were encouraging

Geographic Information System for Upscaling the Seaweed Industry Operation In Two Areas in Mindanao, Southern Philippines

This study used the geographic information system (GIS) in mapping cultured seaweed (Kappaphycus and Eucheuma) areas as production support system for sustainable farming and upscaling of seaweed industry operation. However, the current information on the aerial extent and spatial distribution of seaweeds farms in the Philippines has limited accuracy and reliability. To address this, the ArcGIS tool and spatial method was used in compiling bio-physical and socio-economic data, including the extent of seaweed production areas, the culture techniques and systems, and other relevant information on the various farming sites in the Davao Region and major production areas in Tawi-Tawi Province of Mindanao, Southern Philippines. The results show that major source of seaweeds in Davao Region comes from Davao del Sur while for Tawi-Tawi, the bulk of production is from Sitangkai. For seaweed extent, Davao Region reaches a total of 408.59 ha while Tawi-Tawi covers 47,802.18 ha. In terms of the salinity level, Davao Region ranges from 27 to 32 ppt and Tawi-Tawi from 31 to 32 ppt. Temperature level ranges from 26 to 27 °C in Davao Region and 27– 30 °C in Tawi-Tawi. As to the socio-economic dimension, the most common farming method applied in both areas is the multiple floating long-line; however, several culture systems were recorded such as basket, monoline, and fix-off bottom methods. The product flow and value chain mapping suggest the absence of consolidators in some areas and the lack of coordination and complementation among seaweed industry enablers, which may have contributed setbacks to the industry on top of the prevailing problems on diseases and environment-related issues. The results of this study may assist decision making for seaweed farming operations and eventually upscale the seaweed industry in Mindanao and the whole country

Soybean Residual Effects on a Following Corn Crop

The reason for the yield advantage of rotations is still speculative. Differences in soil nutrients, soil moisture, diseases, insects, weeds, and soil physical properties have all been considered to be responsible for this effect. It was not until the late \u2770s that a non-nitrogen soybean effect on the following corn crop was substantially documented. Corn after soybeans consistently performed better than second-year corn irrespective of nitrogen fertilization. In previous work done with the soybean-corn rotation, there has never been an evaluation of the potentially different effects of soybean varieties on following corn yields. This study aimed to evaluate whether such differences exist

Characterization of Aerosols Containing Microcystin

Toxic blooms of cyanobacteria are ubiquitous in both freshwater and brackish water sources throughout the world. One class of cyanobacterial toxins, called microcystins, is cyclic peptides. In addition to ingestion and dermal, inhalation is a likely route of human exposure. A significant increase in reporting of minor symptoms, particularly respiratory symptoms was associated with exposure to higher levels of cyanobacteria during recreational activities. Algae cells, bacteria, and waterborne toxins can be aerosolized by a bubble-bursting process with a wind-driven white-capped wave mechanism. The purposes of this study were to: evaluate sampling and analysis techniques for microcystin aerosol, produce aerosol droplets containing microcystin in the laboratory, and deploy the sampling instruments in field studies. A high-volume impactor and an IOM filter sampler were tried first in the laboratory to collect droplets containing microcystins. Samples were extracted and analyzed for microcystin using an ELISA method. The laboratory study showed that cyanotoxins in water could be transferred to air via a bubble-bursting process. The droplets containing microcystins showed a bimodal size distribution with the mass median aerodynamic diameter (MMAD) of 1.4 and 27.8 μm. The sampling and analysis methods were successfully used in a pilot field study to measure microcystin aerosol in situ