X-Ray Radiation Effect in DRAM Retention Time

For quality verification, an X-ray inspection process is commonly being used for evaluating obscured and defective solder joints in surface-mount technologies, such as ball grid arrays and flip chips. Integrated circuits subjected to any form of radiation, i.e., ionizing or nonionizing, may incur some amount of damage depending on the absorbed dose. Though most X-ray inspections for high-quality imaging require ionizing dose amounts that are considered inconsequential for device failure or non-functionality, the degree of latent damage must be carefully considered. This paper discusses X-ray-induced vulnerabilities of high-density dynamic random access memory exposed to low ionizing radiation levels typical in X-ray inspection systems. We look at critical parameters and their sensitivity in relation to varying dose amounts of X-ray irradiation. In consideration of different methodologies of reducing radiation dose amounts and limiting device exposure, we propose a procedure for attenuating potentially harmful X-ray radiation levels while preserving quality images.     

Spawning by walleye (Sander vitreus) and white sucker (Catostomus commersoni) in the Detroit River: Implications for spawning habitat enhancement

Few active fish spawning grounds have been found in channels connecting the Great Lakes. Here, we describe one near Belle Isle in the Detroit River, part of the channel connecting lakes Huron and Erie. There, in 2005, we collected 1,573 fish eggs, cultured them, and identified the hatched larvae as walleye (Sander vitreus) and white sucker (Catostomus commersoni). Walleye spawning peaked during the week of April 12–19; white sucker spawning peaked on May 10. Average areal rate of egg deposition by walleye and white sucker at this spawning ground in 2005 was 346 and 25 eggs/m², respectively. Our environmental measurements showed that bottom substrates on this spawning ground were largely sand, not optimal for fish reproduction. We hypothesize that reproduction of these fish at this spawning ground could be enhanced by adding rock and gravel substrates for protection of deposited fish eggs and suggest that reproduction by walleye in the Detroit River may add resilience to production of walleye in western Lake Erie.     

Design and construction of microclimate monitoring system

A portable and user-friendly weather monitoring system based on the PIC16F876 microcontroller is described. This instrument measures three parameters: temperature in the range from -10 to +70 degrees C within +/-1 degrees C using an LM335 temperature sensor, wind speed from 0 to 10 m/s within +/-0.1 m/s using a heated bead thermistor, and solar radiation from 0 to 1000 W/m(2) within +/-10 W/m(2) using a solar cell. These variables are displayed digitally, one at a time, with a 5 s separation. The values are stored on EEPROM at 2 min intervals. The instrument is intended for use in agriculture and for educational purposes.     

Push Notifications in Diet Apps: Influencing Engagement Times and Tasks

Background: Smartphones have reached levels of popularity and penetration where they are now suitable for use in population health interventions. A key feature of smartphones is push notification or in app messaging service, which can be used to alert users to messages or instructions pertaining to an installed app. Little evidence exists as to the persuasive power of these messages.

Method: We conducted a 24-week live user evaluation of push notifications used in a behavior-based mobile app for a meal replacement program to understand the role of push notifications in persuading users to engage with self-monitoring tasks.

Results: User perception of the prompts were verified through questionnaires, which in conjunction with the interaction logs show that users were tolerant of multiple daily prompts. The decline in compliance to the tasks set, however, shows that while the participants did not object to receiving prompts, they were less likely to respond to them as the study progressed.

Conclusions: Push notifications and user tasks are appropriate mechanisms to engage users with mobile technology in the short term.     

Imprinted polymers for water purification

Imprinting polymerization is used to make resins with a high capacity for cadmium ions for wastewater treatment. A random copolymer of methacrylate and methacrylamide was found to be most effective, especially when the porosity of the resin is increased. Complete removal for up to 80 ppm of cadmium with only 50 mg of resin was demonstrated with the imprinted resins, but not the nonimprinted reference samples. This shows that imprinting polymerization improves the capacity of the resin in the uptake of cadmium ions. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Determination of structural building blocks in heavy petroleum systems by collision-induced dissociation Fourier transform ion cyclotron resonance mass spectrometry

Collision-induced dissociation Fourier Transform ion cyclotron resonance mass spectrometry (CID-FTICR MS) was developed to determine structural building blocks in heavy petroleum systems. Model compounds with both single core and multicore configurations were synthesized to study the fragmentation pattern and response factors in the CID reactions. Dealkylation is found to be the most prevalent reaction pathway in the CID. Single core molecules exhibit primarily molecular weight reduction with no change in the total unsaturation of the molecule (or Z-number as in chemical formula C(c)H(2c+Z)N(n)S(s)O(o)VNi). On the other hand, molecules containing more than one aromatic core will decompose into the constituting single cores and consequently exhibit both molecular weight reduction and change in Z-numbers. Biaryl linkage, C(1) linkage, and aromatic sulfide linkage cannot be broken down by CID with lab collision energy up to 50 eV while C(2)+ alkyl linkages can be easily broken. Naphthenic ring-openings were observed in CID, leading to formation of olefinic structures. Heavy petroleum systems, such as vacuum resid (VR) fractions, were characterized by the CID technology. Both single-core and multicore structures were found in VR. The latter is more prevalent in higher aromatic ring classes.     

How not to do research: or How I escaped alive from a social service agency.

Relates a personal experience of being in charge of a research project in a social service agency. Problems encountered included lack of office space and equipment, hiring of assistants, and conflicting views of project personnel. (0 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nearshore Phytoplankton of Hammond Bay,Lake Huron

To predict the effects of increased nutrient loading on nearshore phytoplankton populations in northern Lake Huron, we collected phytoplankton from a small, nearshore water intake at Hammond Bay four times per week from August 1973 to July 1975. Phytoplankton density, taxonomic composition, and biomass in the nearshore waters followed predictable, seasonal fluctuations during each of two 12-month periods. The density of total phytoplankton was high (450 to 650 cells/mL) in June and low (60 to 210 cells / mL) from January to April each year. The mean annual composition of the phytoplankton assemblage by number for the study period was 33% cryptomonads, 24% diatoms, 16% chrysophytes, 16% blue-green algae, and 10% green algae. Phytoplankton biomass was low throughout each year (range, 0.09 to 0.66 g/m³), resembling values previously reported from Lake Superior. Pennate diatoms contributed 60 to 80% of the total biomass from December to April and in July. Phytoflagellates consisting of chrysophytes and cryptomonads accounted for 35% of the biomass throughout the 2-year study.     

Australia’s nutritional food balance: situation,outlook and policy implications

Australia is a food trading nation with a complex food system. Change can have important implications for rural communities, employment, trade, public health nutrition and food security. This study compares Australian food intake scenarios to 2050 with linear projections for Australian agricultural production. The study is distinguished by its nutritional perspective, characterising food balance in terms of basic foods rather than food energy or macronutrients, as well as its systems perspective, taking into account the transformations that occur in food processing and cooking, livestock feed requirements, as well as supply chain and kitchen losses. With Australia’s population projected to increase from around 23 million in 2015 to 37.5 million in 2050, substantial increases in domestic food supply will be required. Although the situation and outlook differ for each commodity, in most respects demand is projected to increase at a greater rate than local production. This suggests that the Australian food system is on a trajectory toward reduced net food exports and increased dependence on imports. This will have implications for Australia’s role in the global food system and presents a change in some of the determinants of national food security. The trajectory of the food system also appears to be at odds with the massive public health challenges associated with diet related disease. These and other implications of an enlarging and increasingly international food system are discussed.     

Use of Aerial Photography to Inventory Aquatic Vegetation

This study demonstrates the feasibility of using low‐altitude aerial photography to inventory submersed macrophytes in the connecting channels of the Great Lakes. For this purpose, we obtained aerial color transparencies and collateral ground truth information about submersed vegetation at 160 stations within four study sites in the St. Clair and Detroit rivers, September 17 to October 4, 1984. Photographs were interpreted by five test subjects to determine with what accuracy they could detect beds of submersed macrophytes, and the precision of delineating the extent of such vegetation beds. The interpreters correctly determined the presence or absence of vegetation 80% of the time (range 73–86%). Differences between individuals were statistically significant. Determination of the presence or absence of macrophytes depended partly on their relative abundance and water clarity. Analysis of one photograph from each of the four study sites revealed that photointerpreters delineated between 35 and 75 ha of river bottom covered by vegetation. This wide range indicates that individuals should be tested to assess their relative capability and be trained before they are employed to delineate plant beds in large‐scale inventories. Within limits, low‐altitude aerial photography, combined with collateral ground truth information, can be used to determine the presence or absence and delineate the extent of submersed macrophytes in connecting channels of the Great Lakes.