Rocky Research (United States)

Birt-Hogg-Dubé syndrome (BHDS) is a rare genetic disorder characterized by cutaneous, pulmonary, and renal manifestations. We present a unique case in which a combination of multiple chronic illnesses, genetic testing, and significant family history led to a diagnosis of BHDS. A 72-year-old male patient presented to their primary care physician with a persistent cough of four months and was admitted to the emergency department after the discovery of a left hydropneumothorax. The patient's medical history was significant for recurrent spontaneous bilateral pneumothoraces diagnosed over 20 years ago, chronic obstructive pulmonary disease (COPD), and many other systemic illnesses. A combination of the patient's significant past medical and family history led to a diagnosis of BHDS. Genetic testing was also done to confirm the diagnosis. Despite benign skin lesionsbeing the most common finding, they are not always present, as seen in our case, which can result in missed diagnosis. Due to the autosomal dominant nature of BHDS, it is vital to make an accurate diagnosis to allow for proper genetic counseling, as the development of renal cancer is the leading cause of mortality.

Dynamic covalent chemistry (DCvC) has become an important tool in developing smart materials in the past few decades. By incorporating reversible covalent bonds into crosslinked polymer networks, those features that are highly desired in wearable electronics, such as stretchability, malleability, self-healing capability, and closed-loop recyclability, could be achieved. In this perspective, we briefly summarize how DCvC influences the development of dynamic polymer networks and discuss their applications in wearable electronics. The advantages and challenges of wearable electronics with dynamic covalent features are also discussed. In addition, forward-thinking outlooks for future directions of utilizing DCvC in the development of wearable electronics are provided.

Abstract Most previous efforts to calibrate how rotation and magnetic activity depend on stellar age and mass have relied on observations of clusters, where isochrones from stellar evolution models are used to determine the properties of the ensemble. Asteroseismology employs similar models to measure the properties of an individual star by matching its normal modes of oscillation, yielding the stellar age and mass with high precision. We use 27 days of photometry from the Transiting Exoplanet Survey Satellite to characterize solar-like oscillations in the G8 subgiant of the 94 Aqr triple system. The resulting stellar properties, when combined with a reanalysis of 35 yr of activity measurements from the Mount Wilson HK project, allow us to probe the evolution of rotation and magnetic activity in the system. The asteroseismic age of the subgiant agrees with a stellar isochrone fit, but the rotation period is much shorter than expected from standard models of angular momentum evolution. We conclude that weakened magnetic braking may be needed to reproduce the stellar properties, and that evolved subgiants in the hydrogen shell-burning phase can reinvigorate large-scale dynamo action and briefly sustain magnetic activity cycles before ascending the red giant branch.

The government wants to save money by loosening radiation exposure standards–how low will it go?

A persistent image-converter device was utilized to make visible to the astronaut solar images that were isolated, instantaneous flashes on the ATM TV monitors. In addition, these instantaneous images, as well as normal TV images, were recorded with a Polaroid SX-70 camera for study by the astronauts.

A heavy, stiff-bottom drill collar can substantially improve deviation performance, theoretically increasing penetration rates by 50 to 100 percent in deviation-prone areas. The theory, performance characteristics, and experience in fabricating and field testing two depleted-uranium alloy heavy metal collars are detailed. Introduction Reducing the weight on bit provides one of the major techniques for controlling or reducing hole angle. This results in lower penetration rates and increased drilling costs. In both straight holes in deviation-prone areas and in directional wells, the cost of deviation control can become a major portion of the total drilling cost, particularly in areas of high rig cost. particularly in areas of high rig cost. This paper presents a method for theoretically increasing penetration rates by 50 to 100 percent when drilling in deviation-prone areas where the weight response is reasonably linear. By using a heavy, stiff bottom collar, the deviation performance of the drillstring can be improved substantially. As is illustrated in Fig. 1, the addition of a heavy metal collar to the drill-collar string allows more weight to be applied to the bit while maintaining the same hole angle. The paper develops the underlying theory that shows how a heavy metal collar can be used to advantage in deviation control. The theory is used to develop practical charts on the performance characteristics of heavy metal drill-collar performance characteristics of heavy metal drill-collar strings for use in selecting suitable hookups. The paper concludes by detailing Shell Development Co.'s experience in fabricating and field testing two heavy metal collars made from a depleted-uranium alloy. Hole Deviation Mechanics The combination of drill-bit/rock interaction and drillstring mechanics that controls hole deviation has been discussed in detail. A principal concern of hole-deviation mechanics is to develop techniques to maximize weight on bit for faster drilling while controlling hole deviation. The tendency for increasing hole deviation with increased weight on bit must be resisted by increased lateral force on the bit. This lateral force is supplied by the pendulum behavior of the drill collars. The longer the pendulum length and the heavier the pendulum, the higher the lateral force will be to resist deviation. Pendulum length and weight increase with drill-collar stiffness and density. The effect of drill-collar density and stiffness on deviation performance can be illustrated by the three cases shown in Fig. 2. The first case, shown for comparison, is an unstabilized 8-in.-diameter steel drill-collar string in a 5 degrees, 12 1/4-in. -diameter hole. The second case is identical to the first (in size and weight per foot), except the collar stiffness is reduced to the stiffness of a 6 1/4-in.-diameter collar string. The final case shows the effect of replacing the bottom steel drill collar with a drill collar made of a heavier material, such as depleted uranium. Notice that, to maintain the same drilling conditions with the more flexible drillstring, the weight on bit must be reduced by 20 percent for the condition shown. Conversely, by using the heavier drillstring. the weight on bit can be increased 60 percent in this example, resulting in a corresponding increase in the penetration rate. Heavy metals structurally suitable for drill-collar service are much more expensive per unit volume than steel. JPT P. 521

New procedures in analysis of soil properties and estimating volume of water to be expected for dewatering and pressure relief of construction excavations; comparative discussion of conventional wellpoints, high-lift systems with ejectors, and submersible or turbine pump units, sand drains, and grout curtain walls; examples of use of dewatering systems in construction works.