Sample pre-treatment effects on identification of smectite by X-ray diffraction

Analysing the mineral assemblage of soils and their clay fractions requires extensive pre-treatment, such as removal of carbonates, iron oxides, and organic matter, as well as dispersion procedures. These pre-treatments affect the properties of target minerals, and thus, hamper their identification. Smectites, being expandable and of small particle size, are most prone to undesired changes upon pre-treatments. We studied the changes in X-ray diffraction patterns of smectite-dominated soil material (topsoil and subsoil of vertisols) in response to sequential pre-treatments. The sequence started with the removal of carbonates (by HCl), followed by the removal of iron oxides (dithionite-citrate-bicarbonate (DCB) method, without heating) and organic matter by H2O2 or NaOCl (at pH 8). Last, the samples were dispersed either in sodium pyrophosphate or sodium pyrophosphate in combination with sonication. Untreated material and material from each treatment step was magnesium-saturated, and then freeze dried. Textured specimen were analysed by X-ray diffraction. The pre-treatments had small effects of the position of the 001 reflection, with a tendency to larger d spacing with increasing numbers of pre-treatments. This suggests increasing accessibility of the interlayer spaces, probably by increasing dispersion of the samples. Also, the width of the 001 reflection was little affected by the different treatments. Pre-treatment of soil samples with HCl for removal of carbonates, with DCB for iron oxide removal, and with H2O2 for organic matter removal had either some positive or only little negative effects on the intensity of 001 reflection of smectite. Dispersion with pyrophosphate, especially in combination with sonication, strongly decreased the 001 reflection. Treatment with NaOCl resulted in a more complete removal of organic matter than H2O2, however, at the cost of a pronounced drop the intensity of the 001 reflection. In summary, all pre-treatments of soil samples for X-ray analyses have the potential to hamper the identification of smectite. The effect of the removal carbonate, iron oxides, and organic matter is little; these treatments may even support the identification in some samples. Dispersion with pyrophosphate or by sonication and the treatment with NaOCl may impair the identification of smectite in textured specimen

Intrapore-Texturized Vanadia-Hydrate Supercapacitor with Ultrahigh Area-Normalized Capacitance

A pressing need for ultrahigh area‐normalized capacitance emerges from the migration to miniaturized composite supercapacitors. Herein, an advanced electric field‐assisted sol–gel synthesis protocol that allows to obtain ribbon‐like vanadium oxides that preferentially creep along the porous tunnels in a commercially available carbon host of low density is demonstrated. In particular, this design offers 1) to convert the original submicrometer‐sized pore network into hierarchically macroporous yet 3D‐interconnected bicontinuous composite frameworks and 2) to considerably add pseudo‐capacitive functionalities onto a highly conductive carbon cloth backbone. Both are demonstrated by an unprecedented area‐normalized capacitance exceeding 5 F cm−2. Moreover, the as‐designed symmetric supercapacitor is characterized by a maximum area‐normalized cell capacitance in the order of 1 F cm−2, a geometric energy density of 0.34 mW h cm−2, and a geometric power density of 28.3 mW cm−2. These features outperform commercial double‐layer supercapacitors as well as many state‐of‐the‐art composite pseudo‐capacitors and lithium‐ion microbatteries

Black Perspectives on Creativity, Trustworthiness, Welcome and Well-Being--Findings From a Qualitative Study

Culture + Community in a Time of Transformation: A Special Edition of Culture Track is a collaborative effort to keep the cultural sector in dialogue with its communities and participants during the pandemic and inform deeper equity and justice in the years to come. The project pivoted from examining public attitudes and behaviors in a "time of crisis" in 2020 to doing so in a "time of transformation" in 2021, with a crucial focus around racialized experiences in connection with cultural participation and cultural organizations.The first phase of the research, conducted in Spring 2020, was a large-scale survey intended to inform not just resilience but also innovation and progress toward equity in the cultural sector, and to give the U.S. public a voice in the future of cultural engagement. But that first phase was designed and conducted before the murder of George Floyd ignited a national upswell of anger, sadness, and activism and the Movement for Black Lives began to reshape the discourse around racism in every aspect of American life. In a follow-up statistical analysis of the same (early 2020) data published in December as "Centering the Picture," we and our colleagues explored respondents' experiences in relation to their racial and ethnic identities to highlight and amplify what people of color have been going through and what they would like to see changed in the future. The report revealed some unique experiences and perspectives that Black and African American adults in the U.S. have in relation to cultural engagement, digital connection with arts and culture, and social change. The Slover Linett team, knowing that qualitative methods would be necessary to understand those perspectives in a more nuanced and holistic way, advocated for an additional phase of research in 2021 that would offer a triangulation with — as well as departure point from — the twowave quantitative survey.To that end, and in order to authentically amplify Black voices and stories, we dedicated this qualitative phase of the research solely to Black and African American participants' perspectives, since those viewpoints have historically been excluded or sidelined in most research studies and planning efforts in the cultural field. We intentionally took a broad approach to this inquiry, exploring general dynamics of creativity, trustworthiness, welcome, and community support rather than focusing narrowly on arts and culture organizations and attendance. This allowed us to hear and explore how culture and community experiences and organizations naturally fit into peoples' lives, and it led to rich insights that can inform practice, funding, and policy

Real Time RF Simulator (RTS) and control

The multi-cavity RTS allows LLRF algorithm development and lab testing prior to commissioning with real cavities and cryomodules. The RTS is a valuable tool since it models the functions, errors and disturbances of real RF systems. The advantage of a RTS over an off-line simulator is that it can be implemented on the actual LLRF hardware, on the same FPGA and processor, and run at the same speed of the LLRF control loop. Additionally the RTS can be shared by collaborators who do not have access to RF systems or when the systems are not available to LLRF engineers. The RTS simulator incorporates hardware, firmware and software errors and limitations of a real implementation, which would be hard to identify and time consuming to model in off-line simulations

Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure

Sperandio PA, Oliveira MF, Rodrigues MK, Berton DC, Treptow E, Nery LE, Almeida DR, Neder JA. Sildenafil improves microvascular O-2 delivery-to-utilization matching and accelerates exercise O-2 uptake kinetics in chronic heart failure. Am J Physiol Heart Circ Physiol 303: H1474-H1480, 2012. First published September 28, 2012; doi:10.1152/ajpheart.00435.2012.-Nitric oxide (NO) can temporally and spatially match microvascular oxygen (O-2) delivery (QO(2mv)) to O-2 uptake (VO2) in the skeletal muscle, a crucial adjustment-to-exercise tolerance that is impaired in chronic heart failure (CHF). To investigate the effects of NO bioavailability induced by sildenafil intake on muscle QO(2mv)-to-O-2 utilization matching and VO2 kinetics, 10 males with CHF (ejection fraction = 27 +/- 6%) undertook constant work-rate exercise (70-80% peak). Breath-by-breath VO2, fractional O-2 extraction in the vastus lateralis {similar to deoxy-genated hemoglobin + myoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy}, and cardiac output (CO) were evaluated after sildenafil (50 mg) or placebo. Sildenafil increased exercise tolerance compared with placebo by similar to 20%, an effect that was related to faster on-and off-exercise VO2 kinetics (P 0.05). On-exercise [deoxy-Hb + Mb] kinetics were slowed by sildenafil (similar to 25%), and a subsequent response overshoot (n = 8) was significantly lessened or even abolished. in contrast, [deoxy-Hb + Mb] recovery was faster with sildenafil (similar to 15%). Improvements in muscle oxygenation with sildenafil were related to faster on-exercise VO2 kinetics, blunted oscillations in ventilation (n = 9), and greater exercise capacity (P < 0.05). Sildenafil intake enhanced intramuscular QO(2mv)-to-VO2 matching with beneficial effects on VO2 kinetics and exercise tolerance in CHF. the lack of effect on CO suggests that improvement in blood flow to and within skeletal muscles underlies these effects.Universidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilQueens Univ, Dept Med, Div Resp & Crit Care Med, Kingston, ON K7L 3N6, CanadaUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Resp Dis, Pulm Funct & Clin Exercise Physiol Unit, BR-04020050 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, Div Cardiol, BR-04020050 São Paulo, BrazilWeb of Scienc

Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods A (07/31/2013

Pain Behavior Changes Following Disc Puncture Relate to Nucleus Pulposus Rather than to the Disc Injury Per Se: An Experimental Study in Rats

It has previously been demonstrated that disc puncture in the rat induced changes in grooming and wet dog shakes, two behavioral changes that may be linked to discomfort and neuropathic pain. In this study the aim was to separate the effects of disc injury and the epidural presence of nucleus pulposus. Following anesthesia, the L4-5 disc was exposed using a dorsal approach. Ten rats received a superficial disc injury without nucleus pulposus leakage and ten rats received nucleus pulposus from a donor rat without disc injury. In ten animals the L4-5 disc was punctured using a ventral approach, with 10 corresponding controls. Spontaneous behavior was assessed after surgery. The data was matched to historical control of dorsal sham surgery and disc puncture. The study showed that the effects of nucleus pulposus were more pronounced than the effects induced by the disc injury. Ventral disc puncture did not induce any behavioral changes different from sham exposure. In conclusion, the data from the study indicate that behavioral changes induced by disc puncture are more likely to relate to the epidural presence of nucleus pulposus than the disc injury per se