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Abstract: Hydrogen is the fuel used by the National Aeronautics and Space Administration (NASA) for the Space Shuttle Main Engine (SSME), among others. The purity of the hydrogen fuel is very important for the performance of hydrogen-fueled engines. In the present work, we have designed, developed, and tested a state-of-the-art laser-induced breakdown spectroscopy (LIBS) based optical sensor to detect four important trace level impurities (i.e. nitrogen, argon, oxygen, and helium) in hydrogen as a rocket fuel. The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen fuel storage tanks and supply lines. LABVIEW® based software is also developed to control and operate the optical sensor. The software performs the data analysis and provides elemental concentrations (in ppm) of these impurities. The sensor has estimated limits of detection of 80ppm for nitrogen, 97ppm for argon, 10ppm for oxygen, and 25ppm for helium. This prototype sensor is easy to deploy in the field. [Copyright &y& Elsevier]

Introduction. Prostate cancer is a disease with major social and economic impact, therefore the development of minimally invasive therapeutic methods is highly important worldwide. Prostate crytherapy fulfills the requirements and was extensively developed in the USA . Material and method. We carried out a prospective study of 556 patients with prostate adenocarcinoma, treated by US-guided transperineal primary prostate cryotherapy between October 2006-July 2010 at the Institute of Urology and Renal Transplantation of Cluj-Napoca and the Lukmed Urology Clinic. Prostate cryoablation was performed using the Oncura 200 Golden SeedNet 2 cryotherapy system, based on argon cooling and active heating with helium, and which may use up to 25 cryotherapy needles simultanoeusly and 5 temperature sensors. The study included patients with stage T1c-T3a tumours, without metastases or severe urinary obstruction (IPSS<30), and with no history of abdomin-perineal resection for colorectal cancer or rectal stenosis. We assessed the early and late complications of this procedure. Results. The patients in the study group were followed up for 12 to 54 months, mean period 31.6 months. The patients' age ranged between 50 and 89 years, mean age 65.96 years. The most frequent complications of cryotherapy were perineal echymosis (59.9%), lower urinary tract symptoms (33.1%) and scrotal echymosis (27.2%). Rectal or pelvic pain occurred in 9.2% of cases, penile hypoesthesia in 3.6%, urinary tract infection in 9.7%, while urethral stricture was 3.4%. Erectile function one year after the operation was preserved in 303 patients (54.7%), while in 251 (45.3%) it worsened. Severe complications rate was minimal (one patient, representing 0.2%). Urinary incontinence after 3 months was noted in only 2.9%. Intestinal occlusion and hydronephrosis respectively were not reported in this group. Conclusions. Prostate cryotherapy is a valid therapeutic option for prostate cancer; increasing the efficiency of the procedure will further reduce postoperative complications. Moder cryotherapy equipment and use of fine cryotherapy needles (IceRoad), together with controlled freezing of the tumoral tissue, have opened a new era in the treatment of prostate cancer, with minimal complications. [ABSTRACT FROM AUTHOR]

Abstract: Lakes are highly sensitive recorders of climate processes, but are extremely difficult to correlate precisely to ice-core and marine records, especially in the absence of reliable radiocarbon dates. Relative paleointensity (RPI) of Earth''s magnetic field is an independent method of correlating high-resolution climate records, and can be applied to both marine and terrestrial sediments, as well as (inversely) correlated to the cosmogenic nuclide records preserved in ice cores. Here we present the correlation of an RPI record from Mono Lake, California to GLOPIS, the Global PaleoIntensity Stack, which increases the age estimation of the basal Mono Lake sediments by >20000 yr (20 kyr), from ∼40 ka (kyr before present) to 67 ka. The Mono Lake sediments thus preserve paleoclimatic records of most of the last glacial period, from 67 to 14 ka. In addition, the paleointensity-based age of 40 ka for the geomagnetic excursion preserved at Mono Lake indicates that this is a record of the global Laschamp excursion. [Copyright &y& Elsevier]

Discusses the 40Ar/ 39Ar geochronology of the Eocene Green River formation in Wyoming. Biostratigraphy; Magnetostratigraphy; Lithostratigraphic correlation across the basin.

Discusses the 40Ar/ 39Ar geochronology of the Eocene Green River formation in Wyoming. Biostratigraphy; Magnetostratigraphy; Inheritance of xenocrysts or detrital grains; Incremental heating; Single-crystal laser fusion.

The Laschamp Geomagnetic Excursion (ca. 41 ka) and a related increase of cosmogenic nuclides provides a global tie point among sedimentary and ice core records. In the Wilson Creek Formation, Mono Lake, California, the Laschamp Excursion has not been recognized although the so-called Mono Lake excursion was found in the section with an estimated age of about 28 14C ka. However, our reevaluation of the age of the Mono Lake excursion at its type locality using new 14C dates on carbonates and 40Ar/39Ar sanidine dates on ash layers yields an estimate of 38–41 ka. This chronology and the absence of a second excursion in the Wilson Creek Formation suggest that the distinct paleomagnetic feature with negative inclinations at Mono Lake is correlative with the Laschamp Excursion. [Copyright &y& Elsevier]

Radioisotopes of the noble gases xenon and argon can be important indicators of underground nuclear explosions. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) includes monitoring capabilities to identify potential nuclear explosions conducted in violation of the CTBT. This monitoring currently focuses on measurement of the xenon isotopes 131mXe, 133Xe, 133mXe, and 135Xe. However, it is predicted that within 100 days of an underground nuclear explosion (UNE) 37Ar would be released to the atmosphere at higher concentrations than xenon and with a higher signal to background ratio, depending on the radioxenon background levels. Therefore, inclusion of 37Ar measurement capabilities at atmospheric International Monitoring System (IMS) stations may represent an improvement in the capability to detect a nuclear explosion. At an IMS station location, an understanding of the expected range of background 37Ar activity concentrations is critical to determining what levels would constitute an elevated concentration. This work describes our analysis of atmospheric samples for 37Ar to evaluate the range of background concentrations. Samples were collected at multiple locations withing the United States, with approximately half coming from a sampler co-located with an IMS xenon monitoring station (RN75). The range of 37Ar concentrations measured in atmospheric air samples was relatively narrow; for samples considered detectable, the minimum and maximum measured concentrations were 0.56 and 2.3 mBq/m3, respectively. Comparison of 37Ar and 133Xe concentrations measured at the IMS station indicated some correlation between the measured concentrations. The results presented here demonstrate the capability to detect background concentrations of 37Ar in atmospheric air and provide a basis for potential implementation of 37Ar monitoring at IMS stations. • Measurements of concentrations of 37Ar in atmospheric air samples. • Measurements of concentrations of 133Xe in atmospheric air samples from an international treaty monitoring station. • Comparison of co-located measurements of 37Ar and 133Xe. [ABSTRACT FROM AUTHOR]

While radioisotopes of noble gases are known to be indicators of underground nuclear explosions (UNE), McIntyre et al. (2017) was the first to report the presence of 39Ar in shallow soil gas in association with a decades old UNE. While this finding hinted at the potential application of 39Ar to be used as an indicator of a UNE, doing so would also require an understanding of the natural concentrations of 39Ar present in soil gas. Without knowing the expected range and variability of naturally occurring concentrations of 39Ar, it is difficult to determine what measured concentrations would be indicative of an elevated concentration. This paper presents results from 16 soil gas samples and three atmospheric air samples collected from various locations across the western United States. Shallow soil gas samples were collected into self-contained underwater breathing apparatus (SCUBA) tanks using a custom-built soil gas sampling system and then processed and analyzed for 39Ar. The measured concentrations of 39Ar varied from atmospheric air concentrations to about 3.5 times atmospheric air concentrations (58 mBq/m3). The results presented here represent the first measurements of natural background 39Ar concentrations in shallow soil gas. This data will be necessary if 39Ar is to be used as an indicator of UNE. • Measurements of concentrations of 39Ar in shallow soil gas samples and atmospheric air. • Results are, to the best of our knowledge, first published concentrations of naturally occurring 39Ar in shallow soil gas. • Results compared to previously published concentrations of 39Ar is soil gas measured near an underground nuclear explosion. [ABSTRACT FROM AUTHOR]

Presents the results of a series of experiments on the spectroscopic analysis of laser-driven implosions at the Laboratory for Laser Energetics. Records of time-resolved K-shell argon spectra using two spectrographs; Analysis of the helium-beta line associated with lithium like satellites.

Discusses the relationship of ages of the Steens and Columbia River flood basalts to extension related calc-alkalic volcanism in eastern Oregon. Magnetostratigraphy; 40Ar/ 39Ar radiometric ages for basalts; Chemical and petrographic equivalents of the Grande Ronde Basalt; Incremental heating.

Discusses the relationship of ages of the Steens and Columbia River flood basalts to extension related calc-alkalic volcanism in eastern Oregon. Magnetostratigraphy; [sup 40]Ar/[sup 39]Ar incremental heating; Total fusion analysis of plagioclase.

The Food and Drug Administration (FDA) is announcing that it has issued an order in the form of a letter to HGM Medical Laser Systems, Inc., reclassifying the microsurgical argon laser for use in rhinology and laryngology from class III (premarket approval) to class II (special controls). The order is being codified in the Code of Federal Regulations as specified herein.

Laser use in the United States for the treatment of gastrointestinal disease in general, and for upper GI bleeding in particular has grown exponentially. In 1979, only 3 American medical centers were using lasers for the therapy of UGI bleeding. Today, lasers are employed in more than 200 centers. Recently, the Food and Drug Administration, which regulates its use, has ruled that it is safe and effective, and therefore is no longer considered to be an investigational device. Most commonly it is used to treat discrete lesions such as ulcers, but it has been employed for other lesions, including varices. A recent American randomized controlled trial assessing its efficacy in acute esophageal variceal bleeding, found it to be effective for initial hemostasis; however, rebleeding was common. A key question is whether or not the laser is superior to other less costly and more portable modalities for treating acute UGI bleeding. One U.S. investigator recently presented data which suggested to him that the heater probe was better than the laser. There is insufficient comparative data available to answer the critical question about the relative superiority of one endoscopic treatment modality as compared to another. Foreseeable technologic advances may make laser therapy easier and more effective.