858 resultados para Alternating Gradient Force Magnetometer (AGFM)
Resumo:
We present a programmable microcontroller-driven injection system for the exchange of imaging medium during atomic force microscopy. Using this low-noise system, high-resolution imaging can be performed during this process of injection without disturbance. This latter circumstance was exemplified by the online imaging of conformational changes in DNA molecules during the injection of anticancer drug into the fluid chamber.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
Morphogen gradients infer cell fate as a function of cellular position. Experiments in Drosophila embryos have shown that the Bicoid (Bcd) gradient is precise and exhibits some degree of scaling. We present experimental results on the precision of Bcd target genes for embryos with a single, double or quadruple dose of bicoid demonstrating that precision is highest at mid-embryo and position dependent, rather than gene dependent. This confirms that the major contribution to precision is achieved already at the Bcd gradient formation. Modeling this dynamic process, we investigate precision for inter-embryo fluctuations in different parameters affecting gradient formation. Within our modeling framework, the observed precision can only be achieved by a transient Bcd profile. Studying different extensions of our modeling framework reveals that scaling is generally position dependent and decreases toward the posterior pole. Our measurements confirm this trend, indicating almost perfect scaling except for anterior most expression domains, which overcompensate fluctuations in embryo length.
Resumo:
The AASHO specifications for highway bridges require that in designing a bridge, the live load must be multiplied by an impact factor for which a formula is given, dependent only upon the length of the bridge. This formula is a result of August Wohler's tests on fatigue in metals, in which he determined that metals which are subjected to large alternating loads will ultimately fail at lower stresses than those which are subjected only to continuous static loads. It is felt by some investigators that this present impact factor is not realistic, and it is suggested that a consideration of the increased stress due to vibrations caused by vehicles traversing the span would result in a more realistic impact factor than now exists. Since the current highway program requires a large number of bridges to be built, the need for data on dynamic behavior of bridges is apparent. Much excellent material has already been gathered on the subject, but many questions remain unanswered. This work is designed to investigate further a specific corner of that subject, and it is hoped that some useful light may be shed on the subject. Specifically this study hopes to correlate, by experiment on a small scale test bridge, the upper limits of impact utilizing a stationary, oscillating load to represent axle loads moving past a given point. The experiments were performed on a small scale bridge which is located in the basement of the Iowa Engineering Experiment Station. The bridge is a 25 foot simply supported span, 10 feet wide, supported by four beams with a composite concrete slab. It is assumed that the magnitude of the predominant forcing function is the same as the magnitude of the dynamic force produced by a smoothly rolling load, which has a frequency determined by the passage of axles. The frequency of passage of axles is defined as the speed of the vehicle divided by the axle spacing. Factors affecting the response of the bridge to this forcing function are the bridge stiffness and mass, which determine the natural frequency, and the effects of solid damping due to internal structural energy dissipation.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
Monthly Labor Force Data report produced by the Iowa Workforce Development.
Resumo:
This report documents the Iowa Department of Transportation's accomplishments and ongoing efforts in response to 39 recommendations proposed by the Governor's Blue Ribbon Transportation Task Force at the end of 1995. Governor Terry Branstad challenged the Task Force to "maximize the benefits of each dollar spent from the Road Use Tax Fund."
Resumo:
Uplift gradients can provide the location of highly strained zones, which can be considered to be seismic. The Turan block (Central Asia) contains zones with high gradient of uplift velocities, above the threshold 0.04mm km-1year-1. Some of these zones are associated with important seismic activity and others are not correlated with any recent important recorded earthquakes, however, recent faults scarps as well as diverted rivers may indicate a recent tectonic activity. This threshold of gradient is probably a significant rheologic property of the upper crust. On the basis of these considerations the Uzboy river area is proposed as a potential high seismic hazard zone.
Resumo:
Atomic Force Microscope and related techniques have played a key role in the development of the nanotechnology revolution that is taking place in science. This paper reviews the basic principles behind the technique and its different operation modes and applications, pointing out research worksperformed in the Nanometric Techniques Unit of the CCiTUB in order to exemplify the vast array of capabilities of these instruments.
Resumo:
The Missouri River floods of 2011 will go down in history as the longest duration flooding event this state has seen to date. The combination of above normal snowfall in the upper Missouri River basin followed by the equivalent of nearly one year’s worth of rainfall in May created an above normal runoff situation which filled the Missouri River and the six main reservoirs within the basin. Compounding this problem was colder than normal temperatures which kept much of the snow pack in the upper basin on the ground longer into the spring, setting the stage for this historic event.
Resumo:
On January 29, 1998, a task force was convened by the Iowa Department of Public Health (IDPH) to address the development of bacterial resistance to antibiotics in Iowa. The purpose of this task force was to evaluate and monitor the prevalence of resistance in Iowa, to monitor the status of the problem, and to develop strategies to diminish the risk to the population of Iowa. The goals of the Iowa Antibiotic Resistance Task Force (IARTF) are to facilitate appropriate use of antibiotics, discourage prescribing practices that promote the development of antibiotic resistance, and decrease the spread of antibiotic-resistant organisms with appropriate prevention and control measures. This group has been meeting since 1998 to accomplish these goals.
Resumo:
In appointing the Iowa Privacy Task Force, Governor Vilsack sought to obtain the opinions of both average Iowa citizens and businesses and professionals that work with health and financial information. The Governor recognized that the free flow of information is essential to the vitality of the Iowa economy. At the same time, he also recognized the legitimate fears and concerns of Iowa citizens with the potential loss of privacy inherent in the vast new information flows in this new economy. In order to obtain broad and balanced input, the Governor appointed half the members of the Task Force to represent average Iowa citizens. The other half of the Task Force was appointed with representatives of the financial services industry, providers of health care and the health insurance industry. The Task Force was further balanced to represent the different geographic regions of the state and gender. A total of 32 members were appointed to the Task Force.