Effects of high frequency current in welding aluminum alloy 6061

Uncontrolled high frequency current causes cracking in the heat-affected zone of aluminum alloy 6061 weldments during tungsten inert gas ac welding. Cracking developed when an improperly adjusted superimposed high frequency current was agitating the semimolten metal in the areas of grain boundary

Rapid recreation assessment: a tool to assess visitor use and associated impacts at coastal and marine protected areas

As more people discover coastal and marine protected areas as destinations for leisure-time pursuits, the task of managing coastal resources while providing opportunities for high quality visitor experiences becomes more challenging. Many human impacts occur at these sites; some are caused by recreation and leisure activities on-site, and others by activities such as agriculture, aquaculture, or residential and economic development in surrounding areas. Coastal management professionals are continually looking for effective ways to prevent or mitigate negative impacts of visitor use. (PDF contains 8 pages) Most coastal and marine protected area managers are challenged with balancing two competing goals—protection of natural and cultural resources and provision of opportunities for public use. In most cases, some level of compromise between the goals is necessary, where one goal constrains or “outweighs” the other. Often there is a lack of clear agreement about the priority of these competing goals. Consequently, while natural resource decisions should ultimately be science-based and objective, such decisions are frequently made under uncertainty, relying heavily upon professional judgment. These decisions are subject to a complex array of formal and informal drivers and constraints—data availability, timing, legal mandate, political will, diverse public opinion, and physical, human, and social capital. This paper highlights assessment, monitoring, and planning approaches useful to gauge existing resource and social conditions, determine feasibility of management actions, and record decision process steps to enhance defensibility. Examples are presented from pilot efforts conducted at the Rookery Bay National Estuarine Research Reserve (NERR) and Ten Thousand Islands National Wildlife Refuge (NWR) in South Florida

Very Large Array Detection of the 36 GHz Zeeman Effect in DR21W Revisited

We report on the observation of the 36 GHz methanol maser line in the star forming region DR21W to accurately measure the Zeeman effect. The reported Zeeman signature by Fish et al. (2011) became suspicious after an instrumental effect was discovered in the early days of the Very Large Array Wide-band Digital Architecture (WIDAR) correlator commissioning. We conclude that the previously reported magnetic field strength of 58 mG ((1.7 Hz/mG)/z) is instrumental in nature and thus incorrect. With the improved performance of the array, we now deduce a 3 sigma limit of -4.7 to +0.4 mG ((1.7 Hz/mG)/z) for the line-of-sight component of the magnetic field strength in DR21W.Comment: 6 pages, 1 figure, accepted for publication in Ap

An Artificial Intelligence Approach to International Market Screening DSS

This paper applies artificial intelligence (AI) computing, Kohonan Self-Organizing Maps (SOMs), to the problem of international market selection (IMS). Broadly speaking, IMS can be summarized to consist of three stages a) screening stage, b) identification stage and, c) selection stage. The screening stage often employs some type of grouping technique so that firms can begin to view the potential markets in terms of similarities and differences over variables of interest. The underlying purpose is to screen out or eliminate markets that do not meet certain criteria established by the firm. Statistical techniques such as cluster analysis, discriminant analysis or factor analysis have long been employed at this stage. This study uses empirical data to demonstrate how an AI approach can assist international firms in the screening process and provide them with information that is not readily available by standard statistical techniques

Discovery of 6.035GHz Hydroxyl Maser Flares in IRAS18566+0408

We report the discovery of 6.035GHz hydroxyl (OH) maser flares toward the massive star forming region IRAS18566+0408 (G37.55+0.20), which is the only region known to show periodic formaldehyde (4.8 GHz H2CO) and methanol (6.7 GHz CH3OH) maser flares. The observations were conducted between October 2008 and January 2010 with the 305m Arecibo Telescope in Puerto Rico. We detected two flare events, one in March 2009, and one in September to November 2009. The OH maser flares are not simultaneous with the H2CO flares, but may be correlated with CH3OH flares from a component at corresponding velocities. A possible correlated variability of OH and CH3OH masers in IRAS18566+0408 is consistent with a common excitation mechanism (IR pumping) as predicted by theory.Comment: Accepted for publication in the Astrophysical Journa

Use of Earth Resources Technological Satellite (ERTS) data in a natural resource inventory

There are no author-identified significant results in this report

Testing of Great Bay Oysters for Two Protozoan Pathogens

Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo), are known to be present in Great Bay oysters. With funds provided by the Piscataqua Region Estuaries Partnership ( PREP ), the Marine Fisheries Division of the New Ham pshire Fish and Game Department (NHF&G) continues to assess the presence and intensity of both of these disease conditions in oysters from the major beds within the Great Bay estuarine system. Histological examination s of Great Bay oysters have also revea led other endoparasites

Testing of Great Bay Oysters for Two Protozoan Pathogens

Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus (Dermo), are known to be present in Great Bay oysters. With funds provided by the Piscataqua Region Estuaries Partnership (PREP), the Marine Fisheries Division of the New Hampshire Fish and Game Department (NHF&G) continues to assess the presence and intensity of both of these disease conditions in oysters from the major beds within the Great Bay estuarine system. Histological examinations of Great Bay oysters have also revealed other endoparasites