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https://www.readbyqxmd.com/read/28340476/temporal-patterns-of-co2-and-ch4-in-a-rural-area-in-northern-spain-described-by-a-harmonic-equation-over-2010-2016
#1
Beatriz Fernández-Duque, Isidro A Pérez, M Luisa Sánchez, M Ángeles García, Nuria Pardo
The present paper seeks to improve our knowledge concerning the evolution of CO2 and CH4 in terms of monthly trends, growth rate and seasonal variations in the lower atmosphere. Dry continuous measurements of CO2 and the CH4 mixing ratio were carried out over five and a half years (from 15 October 2010 to 29 February 2016) by multi-point sampling at 1.8, 3.7 and 8.3m, using a Picarro analyzer at a rural site in the Low Atmosphere Research Centre (CIBA), on the upper Spanish plateau. Data were divided into diurnal and nocturnal records...
March 21, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28340435/optimization-of-hydrogen-dispersion-in-thermophilic-up-flow-reactors-for-ex-situ-biogas-upgrading
#2
Ilaria Bassani, Panagiotis G Kougias, Laura Treu, Hugo Porté, Stefano Campanaro, Irini Angelidaki
This study evaluates the efficiency of four novel up-flow reactors for ex situ biogas upgrading converting externally provided CO2 and H2 to CH4, via hydrogenotrophic methanogenesis. The gases were injected through stainless steel diffusers combined with alumina ceramic sponge or through alumina ceramic membranes. Pore size, input gas loading and gas recirculation flow rate were modulated to optimize gas-liquid mass transfer, and thus methanation efficiency. Results showed that larger pore size diffusion devices achieved the best kinetics and output-gas quality converting all the injected H2 and CO2, up to 3...
March 12, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28336887/sio2-zno-composite-hollow-sub-micron-fibers-fabrication-from-facile-single-capillary-electrospinning-and-their-photoluminescence-properties
#3
Guanying Song, Zhenjiang Li, Kaihua Li, Lina Zhang, Alan Meng
In this work, SiO2/ZnO composite hollow sub-micron fibers were fabricated by a facile single capillary electrospinning technique followed by calcination, using tetraethyl orthosilicate (TEOS), polyvinylpyrrolidone (PVP) and ZnO nanoparticles as raw materials. The characterization results of the scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) spectra indicated that the asprepared composite hollow fibers consisted of amorphous SiO2 and hexagonal wurtzite ZnO...
February 24, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336880/synthesis-of-carbon-nanotubes-in-thermal-plasma-reactor-at-atmospheric-pressure
#4
Lukasz Szymanski, Zbigniew Kolacinski, Slawomir Wiak, Grzegorz Raniszewski, Lukasz Pietrzak
In this paper, a novel approach to the synthesis of the carbon nanotubes (CNTs) in reactors operating at atmospheric pressure is presented. Based on the literature and our own research results, the most effective methods of CNT synthesis are investigated. Then, careful selection of reagents for the synthesis process is shown. Thanks to the performed calculations, an optimum composition of gases and the temperature for successful CNT synthesis in the CVD (chemical vapor deposition) process can be chosen. The results, having practical significance, may lead to an improvement of nanomaterials synthesis technology...
February 18, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336538/effects-of-dobutamine-on-intestinal-microvascular-blood-flow-heterogeneity-and-oxygen-extraction-during-septic-shock
#5
Gustavo Adolfo Ospina-Tascón, Alberto Federico García Marín, Gabriel J Echeverri, William Fernando Bermúdez, Humberto José Madriñán Navia, Juan David Valencia, Edgardo Quiñones, Fernando Rodríguez, Angela Marulanda, César Augusto Arango Davila, Alejandro Bruhn, Glenn Hernández, Daniel De Backer
Derangements of microvascular blood flow distribution might contribute to disturbing oxygen extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric oxygen extraction ratio (mes-ERO2) and the heterogeneity of microvascular blood flow at the gut and sublingual mucosa, during the development and resuscitation of septic shock in a swine model of fecal peritonitis. Jejunal-villi and sublingual microcirculation were evaluated using a portable intravital-microscopy technique...
March 23, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28335680/ampk-knockdown-in-placental-labyrinthine-progenitor-cells-results-in-restriction-of-critical-energy-resources-and-terminal-differentiation-failure
#6
Christopher A Waker, Renee E Albers, Richard L Pye, Savannah R Doliboa, Christopher N Wyatt, Thomas L Brown, Debra Ann Mayes
Placental abnormalities can cause Pregnancy-Associated Disorders including preeclampsia, intrauterine growth restriction, and placental insufficiency that result in complications for both the mother and fetus. Trophoblast cells within the labyrinthine layer of the placenta facilitate the exchange of nutrients, gases, and waste between mother and fetus; therefore, the development of this cell layer is critical for fetal development. As trophoblast cells differentiate, it is assumed their metabolism changes with their energy requirements...
March 23, 2017: Stem Cells and Development
https://www.readbyqxmd.com/read/28335355/influence-of-external-gaseous-environments-on-the-electrical-properties-of-zno-nanostructures-obtained-by-a-hydrothermal-method
#7
Marcin Procek, Tadeusz Pustelny, Agnieszka Stolarczyk
This paper deals with experimental investigations of ZnO nanostructures, consisting of a mixture of nanoparticles and nanowires, obtained by the chemical (hydrothermal) method. The influences of both oxidizing (NO₂) and reducing gases (H₂, NH₃), as well as relative humidity (RH) on the physical and chemical properties of ZnO nanostructures were tested. Carrier gas effect on the structure interaction with gases was also tested; experiments were conducted in air and nitrogen (N₂) atmospheres. The effect of investigated gases on the resistance of the ZnO nanostructures was tested over a wide range of concentrations at room temperature (RT) and at 200 °C...
November 29, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335219/post-plasma-siox-coatings-of-metal-and-metal-oxide-nanoparticles-for-enhanced-thermal-stability-and-tunable-photoactivity-applications
#8
Patrick Post, Nicolas Jidenko, Alfred P Weber, Jean-Pascal Borra
The plasma-based aerosol process developed for the direct coating of particles in gases with silicon oxide in a continuous chemical vapor deposition (CVD) process is presented. It is shown that non-thermal plasma filaments induced in a dielectric barrier discharge (DBD) at atmospheric pressure trigger post-DBD gas phase reactions. DBD operating conditions are first scanned to produce ozone and dinitrogen pentoxide. In the selected conditions, these plasma species react with gaseous tetraethyl orthosilicate (TEOS) precursor downstream of the DBD...
May 13, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28333580/air-quality-measurements-from-rubber-bands-to-tapping-the-rainbow
#9
George M Hidy, Peter K Mueller, Samuel L Altshuler, Judith C Chow, John G Watson
It is axiomatic that good measurements are integral to good public policy for environmental protection. The generalized term for "measurements" includes sampling and quantitation, data integrity, documentation, network design, sponsorship and operations, and archiving and accessing for applications. Each of these components has evolved and advanced over the last 200 years as knowledge of atmospheric chemistry and physics has matured. Air quality was first detected by what people could see smoke and smell contaminated air...
March 23, 2017: Journal of the Air & Waste Management Association
https://www.readbyqxmd.com/read/28331786/a-3d-chemically-modified-graphene-hydrogel-for-fast-highly-sensitive-and-selective-gas-sensor
#10
Jin Wu, Kai Tao, Yuanyuan Guo, Zhong Li, Xiaotian Wang, Zhongzhen Luo, Shuanglong Feng, Chunlei Du, Di Chen, Jianmin Miao, Leslie K Norford
Reduced graphene oxide (RGO) has proved to be a promising candidate in high-performance gas sensing in ambient conditions. However, trace detection of different kinds of gases with simultaneously high sensitivity and selectivity is challenging. Here, a chemiresistor-type sensor based on 3D sulfonated RGO hydrogel (S-RGOH) is reported, which can detect a variety of important gases with high sensitivity, boosted selectivity, fast response, and good reversibility. The NaHSO3 functionalized RGOH displays remarkable 118...
March 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
https://www.readbyqxmd.com/read/28331192/pd-zno-nanorods-based-sensor-for-highly-selective-detection-of-extremely-low-concentration-hydrogen
#11
Mohit Kumar, Vijendra Singh Bhati, Sapana Ranwa, Jitendra Singh, Mahesh Kumar
We report highly hydrogen selective Pd contacted ZnO nanorods based sensor detecting low concentration even at low operating temperature of 50 °C. The sensor performance was investigated for various gases such as H2, CH4, H2S and CO2 at different operating temperatures from 50 °C to 175 °C for various gas concentrations ranging from 7 ppm to 10,000 ppm (1%). The sensor is highly efficient as it detects hydrogen even at low concentration of ~7 ppm and at operating temperature of 50 °C. The sensor's minimum limit of detection and relative response at 175 °C were found 7 ppm with ~38...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28330727/evaluation-of-bam-butorphanol-azaperone-medetomidine-in-captive-african-lion-panthera-leo-immobilization
#12
Aleksandr Semjonov, Vladimir Andrianov, Jacobus P Raath, Toomas Orro, Derik Venter, Liesel Laubscher, Silke Pfitzer
OBJECTIVE: The combination of butorphanol, azaperone and medetomidine (BAM) with subsequent antagonism by naltrexone-yohimbine or naltrexone-atipamezole was evaluated for reversible immobilization of captive African lions (Panthea leo). STUDY DESIGN: Prospective, clinical trial. ANIMALS: Twenty lions, 11 males and nine females, weighing 38-284 kg were immobilized in South Africa. METHODS: The BAM volume dose rate administered was 0...
February 8, 2017: Veterinary Anaesthesia and Analgesia
https://www.readbyqxmd.com/read/28330368/exchange-functionals-based-on-finite-uniform-electron-gases
#13
Pierre-François Loos
We show how one can construct a simple exchange functional by extending the well-know local-density approximation (LDA) to finite uniform electron gases. This new generalized local-density approximation functional uses only two quantities: the electron density ρ and the curvature of the Fermi hole α. This alternative "rung 2" functional can be easily coupled with generalized-gradient approximation (GGA) functionals to form a new family of "rung 3" meta-GGA (MGGA) functionals that we have named factorizable MGGAs...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28330142/an-overview-of-physico-chemical-mechanisms-of-biogas-production-by-microbial-communities-a-step-towards-sustainable-waste-management
#14
REVIEW
Ramansu Goswami, Pritam Chattopadhyay, Arunima Shome, Sambhu Nath Banerjee, Amit Kumar Chakraborty, Anil K Mathew, Shibani Chaudhury
Biogas is a combination of methane, CO2, nitrogen, H2S and traces of few other gases. Almost any organic waste can be biologically transformed into biogas and other energy-rich organic compounds through the process of anaerobic digestion (AD) and thus helping in sustainable waste management. Although microbes are involved in each step of AD, knowledge about those microbial consortia is limited due to the lack of phylogenetic and metabolic data of predominantly unculturable microorganisms. However, culture-independent methods like PCR-based ribotyping has been successfully employed to get information about the microbial consortia involved in AD...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28329240/effect-of-breathing-oxygen-enriched-air-on-exercise-performance-in-patients-with-precapillary-pulmonary-hypertension-randomized-sham-controlled-cross-over-trial
#15
Silvia Ulrich, Elisabeth D Hasler, Stéphanie Saxer, Michael Furian, Séverine Müller-Mottet, Stephan Keusch, Konrad E Bloch
Aims: The purpose of the current trial was to test the hypothesis that breathing oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Methods and results: Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while breathing oxygen-enriched (FiO2 0...
March 11, 2017: European Heart Journal
https://www.readbyqxmd.com/read/28328824/early-use-of-noninvasive-techniques-for-clearing-respiratory-secretions-during-noninvasive-positive-pressure-ventilation-in-patients-with-acute-exacerbation-of-chronic-obstructive-pulmonary-disease-and-hypercapnic-encephalopathy-a-prospective-cohort-study
#16
Jinrong Wang, Zhaobo Cui, Shuhong Liu, Xiuling Gao, Pan Gao, Yi Shi, Shufen Guo, Peipei Li
Noninvasive positive-pressure ventilation (NPPV) might be superior to conventional mechanical ventilation (CMV) in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPDs). Inefficient clearance of respiratory secretions provokes NPPV failure in patients with hypercapnic encephalopathy (HE). This study compared CMV and NPPV combined with a noninvasive strategy for clearing secretions in HE and AECOPD patients.The present study is a prospective cohort study of AECOPD and HE patients enrolled between October 2013 and August 2015 in a critical care unit of a major university teaching hospital in China...
March 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28324711/fire-hazard-reduction-of-hollow-glass-microspheres-in-thermoplastic-polyurethane-composites
#17
Chuanmei Jiao, Hongzhi Wang, Shaoxiang Li, Xilei Chen
Nowadays, reducing the fire hazard of thermoplastic polyurethane (TPU) is an important research direction in the fields of fire safety materials. In this article, hollow glass microsphere (HGM) was used to reduce the fire hazard of TPU in combustion process. The fire characteristics including smoke and heat production of TPU composites were evaluated using smoke density test (SDT) and cone calorimeter test (CCT). And the thermal decomposition and flammable properties were further studied using thermogravimetric analysis/infrared spectrometry (TG-IR) and limiting oxygen index (LOI), etc...
February 24, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28323763/prospective-randomized-clinical-trial-investigating-the-effect-of-the-reamer-irrigator-aspirator-on-the-volume-of-embolic-load-and-respiratory-function-during-intramedullary-nailing-of-femoral-shaft-fractures
#18
Jeremy A Hall, Michael D McKee, Milena R Vicente, Zachary A Morison, Niloofar Dehghan, Christine E Schemitsch, Hans J Kreder, Brad Petrisor, Emil H Schemitsch
OBJECTIVES: We sought to determine whether the use of the Reamer-Irrigator-Aspirator (RIA) device resulted in a decreased amount of fat emboli compared with standard reaming (SR) when performing intramedullary (IM) nailing of femoral shaft fractures. DESIGN: Prospective randomized clinical trial. SETTING: Multi-centered trial, level I trauma centers. PATIENTS/PARTICIPANTS: All eligible patients who presented to participating institutions with an isolated femoral shaft fracture amenable to fixation with antegrade IM nailing...
April 2017: Journal of Orthopaedic Trauma
https://www.readbyqxmd.com/read/28323482/constraints-on-the-early-terrestrial-surface-uv-environment-relevant-to-prebiotic-chemistry
#19
Sukrit Ranjan, Dimitar D Sasselov
The UV environment is a key boundary condition to abiogenesis. However, considerable uncertainty exists as to planetary conditions and hence surface UV at abiogenesis. Here, we present two-stream multilayer clear-sky calculations of the UV surface radiance on Earth at 3.9 Ga to constrain the UV surface fluence as a function of albedo, solar zenith angle (SZA), and atmospheric composition. Variation in albedo and latitude (through SZA) can affect maximum photoreaction rates by a factor of >10.4; for the same atmosphere, photoreactions can proceed an order of magnitude faster at the equator of a snowball Earth than at the poles of a warmer world...
March 2017: Astrobiology
https://www.readbyqxmd.com/read/28323413/designing-morphology-in-epitaxial-silicon-nanowires-the-role-of-gold-surface-chemistry-and-phosphorus-doping
#20
Seokhyoung Kim, David J Hill, Christopher W Pinion, Joseph D Christesen, James R McBride, James F Cahoon
Vertically-aligned semiconductor nanowires (NWs) have many potential applications for NW-based technologies, ranging from solar cells to intracellular sensors. Aligned NWs can be fabricated by top-down etching of planar wafers or synthesized from the bottom-up using the vapor-liquid-solid (VLS) mechanism to induce epitaxial growth on lattice-matched substrates. The VLS process permits the modulation of dopants along the NW growth axis, which, if combined with dopant-dependent wet-chemical etching, can be used to encode precise morphology...
March 21, 2017: ACS Nano
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