Photo Source Research Articles

Preparation of Nanoparticle Doped Metal-organic Framework (MOF) and its Potential Use for Photodegradation of Antibiotics in Water: A Review

Abstract: Semiconductors have gained recognition as efficient photocatalysts for the degradation of antibiotics in water. However, their performance is limited due to poor absorption of light, recombination of electron-hole pairs, and poor recovery from an aqueous solution. This study reviewed the inclusion of semiconductor nanoparticles in a metal-organic framework (MOF), forming nanoparticle@ MOF composite to overcome these challenges. Three methods including ship-in-bottle, bottlearound- ship, and one-step synthesis were identified for the synthesis of nanoparticle@MOF composite. Among the synthesis methods, the one-step method remains promising with high prospects. Nanoparticle@ MOF composite has exhibited high efficiency in removing antibiotics in an aqueous system utilizing visible light as a photo source for promoting the process. Despite the success achieved, there is a need for large-scale studies and cost evaluation to understand better the feasibility and economic implications of the nanoparticle@MOF composite technique as an affordable technique for the purification of an antibiotic-contaminated water system.

Highly Durable Electrocatalyst with Low-Loading Pt-Co Dispersed over Graphene Nanofiber for Oxygen Reduction Reaction Under PEMFC Condition

Proton exchange membrane fuel cell (PEMFC) has been demonstrated as a highly efficient energy conversion technology. The sluggish oxygen reduction reaction (ORR) at the fuel cell cathode requires 3 to 5 times more catalysts than the hydrogen oxidation reaction at the anode (1). Currently, platinum is still the catalyst material of choice. However, the heavy use of scarce Pt in the electrodes represents a major cost barrier to the commercialization of PEMFCs. Tremendous efforts have been dedicated to reduce or remove Pt usage through the development of Pt-transition metal catalysts, as highlighted recently by dealloyed PtNi (2), Mo-doped PtNi(3), and ordered PtCo (4); or through the development of transition metals-nitrogen-carbon based PGM-free catalysts (5, 6).In the fuel cell, catalysts should be highly dispersed over the electrode surface to be easily accessible by the reactants, especially at the high fuel cell current density where a large influx of O2 must be converted. For the Pt alloy catalyst of large crystallites, there won’t be enough crystallites available to spread over the electrode surface to encounter the incoming O2 if the total loading of platinum has to be maintained ultralow. Furthermore, unprotected Pt nano-alloys may lose their nanostructure and crystallinity from the dissolution and agglomeration during the ORR process. The PGM-free catalysts, on the other hand, have high catalytic site density with uniform distribution when prepared by homogenous precursors such as metal-organic framework or porous organic polymer, rendering them highly efficient in interacting with O2 flux. Their key drawback, however, is the poor stability operated under PEMFC condition.In this presentation, we will describe a method of preparing highly active yet stable electrocatalysts containing ultralow Pt content using polymer fiber containing cobalt zeolitic imidazolate framework as precursor. The new catalyst contains Pt-Co nanoparticels situated over the PGM-free catalystically active support (7,8). The ORR activities of the new catalyst was first tested in O2 saturated acidic electrolyte by rotating ring disk electrode (RRDE) before fabricated into the membrane electrode assembly (MEA) and evaluated under fuel cell operating condition. The synergistic catalysis between PtCo NPs and the PGM-free active substrate led to an unprecedented oRR performance in both RRDE and fuel cell. For example, the fuel cell test demonstrated a mess activity of 2.43 A/mgPt for the new catalysts and > 80% retention of the initial mass activity after 60000 continuous voltage cycles from 0.6 – 1.0 V.The characterizations of the fresh and the post-electrochemical test samples were investigated by x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), x-ray absorption near-edge structure (XANES), extended x-ray absorption fine structure (EXAFS), transmission electron microscopy (TEM), Raman spectroscopy and BET surface analysis. We also performed DFT calculation on the ORR thermodynamic barriers over both Pt-Co NPs and PGM-free site as the descriptors for reaction pathway. The results reveal that the synergistic interaction between Pt-Co and PGM active substrate contribute significantly to both activity and durability enhancements.Acknowledgments:This work was supported by Argonne National Laboratory through Maria Goeppert Mayer Fellowship, US; Overseas Outstanding Youth Fund project, shanghai Jiao Tong university, Shanghai, China, State Key Laboratory of Metal Matrix Composites, shanghai Jiao Tong university, Shanghai, China. The works performed at Argonne National Laboratory’s Center for Nanoscale Materials and Advanced Photo Source, and Hydrogen research center, shanghai Jiao Tong university.Reference: H. A. Gasteiger, N. M. Markovic, Just a Dream-or Future Reality? Science 324, 48-49 (2009).B. Han et al., Record activity and stability of dealloyed bimetallic catalysts for proton exchange membrane fuel cells. Energy & Environmental Science 8, 258-266 (2015).X. Huang et al., High-performance transition metal–doped Pt3Ni octahedra for oxygen reduction reaction. Science 348, 1230-1234 (2015).D. Wang et al., Structurally ordered intermetallic platinum-cobalt core-shell nanoparticles with enhanced activity and stability as oxygen reduction electrocatalysts. Nat Mater 12, 81-87 (2013).L. Chong et al., Investigation of Oxygen Reduction Activity of Catalysts Derived from Co and Co/Zn Methyl-Imidazolate Frameworks in Proton Exchange Membrane Fuel Cells. ChemElectroChem 3, 1541-1545 (2016).J. Shui, C. Chen, L. Grabstanowicz, D. Zhao, D. J. Liu, Highly efficient nonprecious metal catalyst prepared with metal-organic framework in a continuous carbon nanofibrous network. Proc Natl Acad Sci U S A 112, 10629-10634 (2015).L. Chong et al., Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks. Science, (2018).L. Chong et al., Highly durable fuel cell electrocatalyst with low-loading Pt-Co nanoparticles dispersed over single-atom Pt-Co-N-graphene nanofiber. Chem Catalysis 3, 100541.

Field test study on the evaluation of the microvibration controlling capacity of a mass concrete layer

Microvibration induced by natural disturbance and human activities has an adverse effect on the operation of the large-scale and ultraprecise facilities in the world. Under such circumstances, a passive vibration control method is generally deployed for such vibration-sensitive facilities, taking the High Energy Photo Source (HEPS) in Beijing as an example, a 3 m-thick mass concrete layer forming a ring foundation was cast at the facility, where a 1 m-thick reinforced concrete slab (RC slab) lies. Since microvibration control plays a crucial role in the operation of such large-scale scientific and ultraprecise facilities and few studies have been reported for large-scale concrete layer as antimicrovibration devices, this paper presents four field tests in Beijing, China, to evaluate the vibration control capacity of a mass concrete layer. Based on a large number of field tests, the effect of applying the concrete layer is discussed, and a reference is provided for the construction of similar facilities. The vibration signals, generated by shock excitation and ambient excitation, are measured through a highly sensitive and high-accuracy vibration acquisition system. It is concluded that the existence of the 1 m-thick RC slab has little influence on the microvibration signal frequency distribution in the vertical direction and that the signals from the concrete layer and subsoil differ by approximately 10 Hz in the vertical direction while differing by approximately 5 Hz in the horizontal direction. The microvibration control ability of the concrete layer is favorable in a higher frequency band over 20 ~ 30 Hz and more than 50% attenuation can be gained through the concrete layer; however, the microvibration control ability is not significant below 20 ~ 30 Hz. The vibration levels across different heights of the concrete layer section are the same. To prevent adverse vibration disturbance below 20 ~ 30 Hz, it is suggested that the traffic and road surface conditions should be taken into consideration when choosing the construction location. In addition, a long-term monitoring shows that 75% vibration energy at the site is firmly related to the construction activities which are approximately 1.4 km from the site.

Design and Field Performance of Octupole Magnet With Skew Quadrupole Component in HEPS

The High Energy Photo Source (HEPS) is being built in China and the magnets are in batch production. The octupole magnets with skew quadrupole component used in the storage ring have been designed and manufactured. The octupole has an aperture of 30 mm, a field gradient of 735000 T/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and a length of 0.26 m. In this paper, detailed magnetic design of HEPS octupole magnets is presented. Different design schemes of the skew quadrupole coils are compared, and the temperature effect on magnetic center and the integral field in the first batch of octupole magnets are also given. In addition, the influence of the combined power-on mode on the magnetic field is studied.

PEMBANGKITAN CITRA TIME EXPOSURE MENGGUNAKAN FILTER MEDIAN

Time exposure (timex) image is a type of image generated from image acquisition at acertain time or image acquisition with different exposure criteria, the advantage of timex imageis High Dynamic Range which can help provide details in a digital image processing. Toproduce a good timex image, a method is needed that is able to create a timex image fromeither a video or photo source. There are several methods used to produce timex images,namely Gradient-Based Synthesized, Multi-Exposure Image, and Median Filter. In this study,the three methods are compared in producing timex images with input in the form of imageswith over exposure and low exposure as well as video images. For testing the timex image, theHistogram, Standard Deviation, Variance, Mean, Median, and Mode parameters are used.Based on the results of research conducted on timex images with the Median Filter method, thestandard deviation value is 0.0739 and the variance value is 0.0054 where this value indicatesthat the intensity distribution on the median timex filter image has a wider dynamic range thanthe other two methods. The comparison of the timex image with the fps variation shows that thehigher the fps used, the better the timex image.

Analysis of Double Peak Detection in a D-Shaped Photonic Crystal Fiber Plasmonic Sensor

We present a novel D-shaped photonic crystal fiber sensor with double loss peaks based on surface plasmon resonance. The proposed sensor has a lot of better characteristics for refractive index detection compared with single-peak sensor. It is worth noting that the trough of the loss spectrum keeps unchanged as the analyte refractive index increases, which indicates that this sensor is extremely stable. In addition, numerical simulation shows that the average wavelength sensitivity can reach 29,000 nm/RIU and the maximum resolution is as high as 3.45 × 10−5 RIU. Furthermore, the coupling theory between fundamental mode and the surface plasmon polarization (SPP) mode is investigated in this paper. It is found that there is obvious competition between the resonant modes. This study has enlightening significance for us to understand the generation mechanism of polarization-entangled quantum photo source.

Oxygen Transport in Electrodes with Degraded d-PtCo/C Cathode Catalyst

We have investigated the mechanism of increase in oxygen transport resistance (Rm) due to aging of electrodes with low-loaded de-alloyed PtCo cathode catalysts supported on high surface area carbon (d-PtCo/C). Commercially available membrane electrode assemblies with 0.05, 0.1 and 0.15 mg/cm2 Pt loadings in d-PtCo/C cathode catalysts were assembled into cells and subjected to accelerated stress tests (ASTs) that consisted of 0.6-0.95 V square wave potentials with 3-s hold at upper and lower potential limits. Catalyst degradation was characterized by measuring mass activity for the oxygen reduction reaction, electrochemically active surface area (ECSA) and polarization performance in H2/air at beginning of test (BOT) and after 15k and 30k (EOT) potential cycles in H2/N2. Concurrently, limiting current densities (iL) were measured for different pressures (1.3, 1.8, 2.3, 2.8 and 3.2 atm) and oxygen concentrations (0.01, 0.02 and 0.04 O2 mole fraction in dry air) at 80oC and 90% relative humidity (RH). We observed that the O2 transport resistance inferred from the measured limiting current densities depends not only on pressure (P), catalyst loading and aging, but also on the current density itself. The observed increase in Rm with iL is almost linear and independent of pressure, suggesting the following new representation for Rm: Rm = {Rg P/Pr + Rd P/Pr} + RKn + {Rf + Ri i/ir}, Rf = RO2/SPt In this representation, the various terms denote the resistance for O2 transport across the boundary layer in the gas channel (Rg), across the gas diffusion layer (Rd), across the microporous layer and secondary pores in cathode electrode (RKn), and across the ionomer film on Pt particles supported on carbon (Rf). Note that Rf is inversely proportional to roughness (SPt, cmPt 2/cm2), and Ri is the portion of Rm that depends linearly on the normalized current density (ir = 1 A/cm2). As in earlier formulations, Rg and Rd are pressure dependent (Pr = 1 atm) as they are related to molecular diffusivity of O2 in gas channel (GC) and in gas diffusion layer (DM), whereas RKn and Rf are pressure-independent as they are related to Knudsen diffusion in <50-nm pores and O2 permeability across the ionomer film. Using the new representation for the three cells with different loadings, we determined Ri from the current density dependence of Rm at BOT as 0.306 ± 0.1 s/cm; Ri was found to be nearly independent of pressure. We estimated Rg + Rd from the pressure dependence of Rm at BOT as 0.409 ± 0.032 s/cm. Knowing Rg, Rd, and Ri, we calculated RKn + Rf from Rm, and plotted it as a function of 1/ SPt to determine RKn from the intercept and Rf from the slope. Using all the available data at BOT and after 15k and 30k potential cycles, the estimated values are 0.07 s/cm for RKn and 9.15 s/cm for RO2. This value of RO2 compares favorably with the reported literature data for fresh electrodes. To explain the current density dependence of Rm, we conducted O2 transport simulations on an electrode microstructure determined from nano-computed X-ray tomography at an APS (Advanced Photo Source) beamline. The microstructure was digitized at a resolution of 2.5 nm to reconstruct the connectivity and heterogeneous size and spatial distributions of secondary pores, primary pores, carbon, catalyst particles, and ionomer phases. Assuming that the secondary pores are dry at 90% RH, the primary pores were progressively filled with liquid water to match the measured increase in electrode resistance at higher limiting current densities. The water-filling algorithm follows the concept of capillary condensation whereby the smallest primary pores are allowed to preferentially saturate first. In these simulations, changing the primary pore saturation from 0 (dry) to 1 (flooded) results in the limiting current density increasing from 0 to 1 A/cm2 and the electrode resistance from 0.2 to 0.65 s/cm. Figure 1 summarizes the effects of Pt loading and catalyst aging on O2 transport resistance at one set of reference conditions: 1.5 atm operating pressure, 4% O2 mole fraction, 80oC and 90% RH. At BOT, reducing Pt loading to 0.05 from 0.15 mg/cm2 causes a 31% increase in Rm and a 23% drop in iL. After 30k cycles, Rm increases by 12% for the 0.15 mg/cm2 loading and by 43% for the 0.05 mg/cm2 loading, and is 66% higher in the lower loaded cell even though iL is 40% smaller. More telling is the increase in the electrode resistance (Rf + Ri i/ir) after 30 k cycles: 35% for 0.15 mg/cm2 loading and 115% for 0.05 mg/cm2 loading. Figure 1

Feasibility study of neutron production at SLRI beam test facility

SLRI Beam Test Facility (SLRI-BTF) has been constructed in order to increase usage of the Siam Photo Source injector. SLRI-BTF aims to provide electron test beams for calibration and testing of high-energy particle detectors and diagnostic instrumentations. The test-beam energy varies from 40 MeV to 1.2 GeV with adjustable intensity from a few to several millions of electrons per repetition rate. Since the test-beam energy is sufficiently large, the electron test beam can be used to produce photoneutrons resulted from collision of high-energy electrons to metal targets. Similar to the electron test beams, this neutron source will be utilized for calibration and testing of neutron detectors and instrumentations. In this work, the neutron production and its angular dependence has been investigated using the PHITS simulation code. The results show that photoneutrons generated by collision of the high-energy electron beam on a tungsten target are in range of intermediate and fast neutrons or 0.01 - 10 MeV with peak contribution at 0.6 ± 0.1 MeV and uniformly distributed in angular direction. For the primary beam of 108 electrons per spill at SLRI-BTF, the photoneutron flux is predicted to be around 50 neutrons/cm2. Based on this study, the possibility to service a neutron source for users in the future will be determined further.

High Active Ultra-Low Pt Content Oxygen Reduction Reaction Catalyst Derived from Metal Organic Framework for PEMFC

Proton exchange membrane fuel cell (PEMFC) has been demonstrated as a highly efficient energy conversion technology. The sluggish oxygen reduction reaction (ORR) at the fuel cell cathode requires 3 to 5 times more catalysts than the hydrogen oxidation reaction at the anode.(1) Currently, platinum is still the catalyst material of choice. However, the heavy use of scarce Pt in the electrodes represents a major cost barrier to the commercialization of PEMFCs. Tremendous efforts have been dedicated to reduce or remove Pt usage through the development of Pt-transition metal catalysts, as highlighted recently by dealloyed PtNi (2), Mo-doped PtNi(3), and ordered PtCo(4); or through the development of transition metals-nitrogen-carbon based PGM-free catalysts (5, 6). In the fuel cell, catalysts should be highly dispersed over the electrode surface to be easily accessible by the reactants, especially at the high fuel cell current density where a large influx of O2 must be converted. For the Pt alloy catalyst of large crystallites, there won’t be enough crystallites available to spread over the electrode surface to encounter the incoming O2 if the total loading of platinum has to be maintained ultralow. Furthermore, unprotected Pt nano-alloys may lose their nanostructure and crystallinity from the dissolution and agglomeration during the ORR process. The PGM-free catalysts, on the other hand, have high catalytic site density with uniform distribution when prepared by homogenous precursors such as metal-organic framework or porous organic polymer, rendering them highly efficient in interacting with O2 flux. Their key drawback, however, is the poor stability operated under PEMFC condition. In this presentation, we will describe a method of preparing highly active yet stable electrocatalysts containing ultralow Pt content using Co or Co/Zn zeolitic imidazolate frameworks as precursors. The new catalysts contain Pt-Co core-shell nanoparticles (NPs) situated over the PGM-free catalytically active support (7). The ORR activities of the new catalysts were first tested in the O2 saturated acidic electrolyte by rotating ring disk electrode (RRDE) before fabricated into the membrane electrode assembly (MEA) and evaluated under fuel cell operating condition. The synergistic catalysis between Pt-Co NPs and PGM-free active substrate led to an unprecedented ORR performance in both RRDE and fuel cell. For example, the fuel cell test demonstrated a mass activity of 1.77 A/mgPt for the new catalysts and > 60% retention of the initial mass activity after 30,000 continuous voltage cycles from 0.6V – 1.0V. The characterizations of the fresh and the post-electrochemical test samples were investigated by x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), x-ray absorption near-edge structure (XANES), extended x-ray absorption fine structure (EXAFS), transmission electron microscopy (TEM), Raman spectroscopy and BET surface analysis. We also performed DFT calculation on the ORR thermodynamic barriers over both Pt-Co NPs and PGM-free site as the descriptors for reaction pathway. The results reveal that the synergistic interaction between Pt-Co and PGM active substrate contribute significantly to both activity and durability enhancements. Acknowledgments: This work was supported by U.S. Department of Energy, Fuel Cell Technologies Office through Office of Energy Efficiency and Renewable Energy. LC wishes to thank Argonne National Laboratory for Maria Goeppert Mayer Fellowship. The works performed at Argonne National Laboratory’s Center for Nanoscale Materials and Advanced Photo Source, U.S. Department of Energy Office of Science User Facilities, is supported by Office of Science, U.S. Department of Energy under Contract DE-AC02-06CH11357. H. A. Gasteiger, N. M. Markovic, Just a Dream-or Future Reality? Science 324, 48-49 (2009).B. Han et al., Record activity and stability of dealloyed bimetallic catalysts for proton exchange membrane fuel cells. Energy & Environmental Science 8, 258-266 (2015).X. Huang et al., High-performance transition metal–doped Pt3Ni octahedra for oxygen reduction reaction. Science 348, 1230-1234 (2015 ).D. Wang et al., Structurally ordered intermetallic platinum-cobalt core-shell nanoparticles with enhanced activity and stability as oxygen reduction electrocatalysts. Nat Mater 12, 81-87 (2013).L. Chong et al., Investigation of Oxygen Reduction Activity of Catalysts Derived from Co and Co/Zn Methyl-Imidazolate Frameworks in Proton Exchange Membrane Fuel Cells. ChemElectroChem 3, 1541-1545 (2016).J. Shui, C. Chen, L. Grabstanowicz, D. Zhao, D. J. Liu, Highly efficient nonprecious metal catalyst prepared with metal-organic framework in a continuous carbon nanofibrous network. Proc Natl Acad Sci U S A 112, 10629-10634 (2015).L. Chong et al., Ultralow-loading platinum-cobalt fuel cell catalysts derived from imidazolate frameworks. Science, (2018).

Breakout Session: View from the Bleachers: Applied Skills in Finding and Using Free Media Resources. Presented by Barbara Waxer, Santa Fe Community College.

The purpose of copyright is to promote the creation of creative content; however, copyright confusion can make students and creators feel limited or intimidated from using media in their work. At the 2017 Kraemer Copyright Conference, Barbara Waxer presented a resourceful session about copyright and Creative Commons licensing through the eyes of information consumers and creators who in essence just want to know whether they can use a certain song, photo, or media source. Waxer’s breakout session highlighted the decision-making process for the copyright conscious by presenting easy-to-use flow charts and online resources that clearly explain Creative Commons licensing, with hopes that librarians can use these tools for teaching copyright at large.

Soil Warming Increases Arsenic Availability in the Rice Rhizosphere

Photo source: Flickr/WorldFish Arsenic is a widely distributed toxic element that naturally occurs in minerals. One of the most common pathways for exposure is when arsenic leaches into drinking water supplies, often through natural weathering/breakdown. People are also exposed to arsenic through food and dust. Long-term exposure is linked to health problems, including skin lesions, cardiovascular disease, and cancer. Research from Bangladesh shows long-term exposure through drinking water increases the rate of morbidity by up to 60% (http://bit.ly/2fFhq6w). Understanding exposure routes and minimizing human consumption and contact with arsenic has widespread human health benefits. One crop known to take up arsenic when the element is available in soils or irrigation water is rice (Oryza sativa L.). Arsenic accumulates throughout the plant tissues including the grain that is consumed. This is concerning for people whose diets include a high proportion of rice or rice products such as regions and cultures where rice is served with most meals, those on a gluten-free diet using rice substitutes (e.g., rice milk or rice flour), and young children who are given rice crackers and rice cereals. Rice plants may be exposed to arsenic through soil or irrigation water. Because of this, the hydrological and biogeochemical processes that take place in the rhizosphere, or the soil zone around the roots of plants, influence arsenic uptake, according to Rebecca Neumann, Assistant Professor in the Department of Civil and Environmental Engineering at the University of Washington. Specifically, rice plants release oxygen from their roots when flooded, which reacts with iron, forming “plaques” along root surfaces. The iron oxide plaques scavenge arsenic, and the plants take up arsenic released from the plaques or dissolved in the soil solution. One factor that can influence rhizosphere processes, which ultimately affect arsenic accumulation in the rice grain, is soil temperature. Because global climate models predict an increase in average temperatures, Neumann and colleagues set up an experiment to determine if elevated soil temperatures would have an effect on plaque formation and arsenic uptake. Their results were recently published in Agricultural & Environmental Letters (see http://bit.ly/2vCtRUO). “We purposefully grew our plants in a system where we could image and visualize the rhizosphere,” Neumann says. The researchers grew plants in rhizoboxes (30 cm 3 20 cm 3 2.5 cm), which enabled them to sample soil porewater and perform synchrotron imaging on the plant root zone at the end of the experiment. Rice plants were kept in growing chambers, where the atmospheric and ambient soil conditions were designed to mimic conditions in Bangladesh. The elevated soil temperature treatment was 5°C higher, which is the upper limit of expected warming in the region. Globally, Bangladesh does not have the highest concentration of arsenic in rice grains; however, “arsenic contamination of rice poses a large human health problem [in Bangladesh] because rice is the staple food. So that was part of the motivation for focusing on and trying to mimic conditions that are relevant in that context,” Neumann explains. X-ray fluorescence data collected for (a,c) one plant from the 26.1°C soil-temperature treatment and (b,d) one plant from the 30.5°C soil temperature treatment. (a–b) Solid-phase iron concentrations in counts per second (cps); concentrations in both panels scale with color bar in panel (a). (c–d) Solid-phase arsenic concentrations in counts per second; concentrations in both panels scale with color bar in panel (c). The synchrotron imaging provided additional information about arsenic in the rhizosphere. The authors report that with warmer soil temperature, there was more iron plaque on roots and more arsenic sequestration. Neumann explains, “There is more arsenic mobilized and made available in the warmer temperatures. This excess arsenic, some of it [is] sequestered in the plaques, and then some of it [is taken up through] the roots.” At the end of the experiment, plants were destructively sampled to test for arsenic levels in plant tissues. The authors report the plants grown in warmer soil temperatures had greater concentrations of arsenic in the porewater, root tissue, straw tissue, and husk. However, arsenic concentrations in the grain did not change with soil temperature. Read the full study in Agricultural & Environmental Letters http://bit.ly/2vCtRUO. While this is a small data set, using a single rice cultivar and focusing only on elevated soil temperature in laboratory conditions, Neumann says the results show, “it's not just plant physiology that can change [with increased temperatures], but actually these processes in the rhizosphere.” Having established this response, Neumann hopes to investigate rhizosphere interactions in other rice cultivars and to scale up to field experiments. Understanding what changes may occur under future climate conditions enables researchers to help mitigate arsenic exposure through rice before it happens.

The Redundant Compressor System for the Helium Cryogenic Plant at TPS

Recommissioning the 700-W helium cryogenic system was completed in 2014 and it entered service in 2015. The main target of this system is a stable supply of liquid helium to the superconducting RF cavities at Taiwan Photo Source. The annual maintenance of the compressor of the plant causes operation of the system to be suspended at least two weeks. To avoid such a long suspension for the cryogenic plant, we installed a redundant compressor system for the cryogenic plant in 2015. We can switch to this redundant compressor system and restart the cryogenic system in a few minutes. In this paper we present the configuration, local testing and long-term operation of this redundant compressor system.

Visible-light emission properties of α-TeO2:Ho3+/Yb3+/Eu3+ nanoparticles via both up- and down-conversion modes

In this study, α-TeO2:Ho3+/Yb3+, α-TeO2:Eu3+ and α-TeO2:Ho3+/Yb3+/Eu3+ nanoparticles were prepared via a simple hydrothermal process. The up- and down-conversion properties of the as-prepared nanoparticles were tested at room temperature under a near-infrared photo source (980 nm) and UV-vis photo source, respectively. The results indicated that α-TeO2 NPs were a kind of outstanding host material for both up- and down-conversion luminescence. The α-TeO2:Ho3+/Yb3+ nanoparticles showed sharp up-conversion emission at 545 and 660 nm under 980 nm excitation, ascribed to the 5S2→5I8 and 5F5→5I8 (Ho3+) transitions, and weaker down-conversion emission at 545 nm under 455 nm excitation, ascribed to the 5S2→5I8 (Ho3+) transitions. The α-TeO2:Eu3+ nanoparticles showed strong down-conversion emission at 592 and 615 nm under 395 nm excitation, attributed to the 5D0→7F1 and 5D0→7F2 (Eu3+) transitions. Possessing the advantages of these two luminescent materials, the as-prepared tri-doped samples of α-TeO2:0.5Ho3+/10Yb3+/3Eu3+ (mol.%) nanoparticles could successfully emit visible light via both up- and down-conversion modes.

Political Communication by Political Parties in 2014 Legislative Election in Indonesia

At this time the image of political parties in Indonesia deteriorated because of various problems afflict their cadres in the Parliament and the executive. In order to increase the public's trust, many political parties begin to perform activities of political communication. This research is aimed to discuss and analyze the political communication held by political parties in the election of 2014. In order to analyze the political communication process conducted by the political parties, researchers using the theory of political communication with the indicator: sources (political communicator), political messages, media or political channels, influence or effect of political communication. The method used is qualitative, with primary data sources such as interviews and observations, as well as secondary data such as photo documentation and source literature obtained from other sources. From the research that has been made known that the political parties use the sources of political communication in the form of print media, electronic, outdoor media, and public communication channel group. Associated with the delivery of a political message, that the political parties use multiple channel messages, both textual and non-verbal, where all of the message channel associated with the media or political channels that are used by political parties, namely the print and electronic media. The results of this study also showed that the influence of political communication has been done by the political parties through the mass media are not always able to influence the attitudes or perceptions of society, because it needs to be seen also from the other side that is the perspective and needs of the community. From the results can be concluded that political communication conducted by political parties through a variety of media is no longer always have a dominant effect because audiences are active and independent.

BJOG Editors‐in‐chief since 1902

Charles James Cullingworth was born in Leeds in 1841. His father was a businessman who sent Charles to Wesley College in Sheffield, where he passed the matriculation examination of the University of London in 1858. After helping his father for several years with a view to becoming a lawyer, his father died, and Charles was able to sell the business and change to a medical career. He was initially apprenticed to a general practitioner while attending a course at the Leeds School of Medicine, qualifying as a member of the Royal College of Surgeons in 1865. After 18 months in general practice, he was elected resident physician assistant at the Manchester Royal Infirmary, and was so efficient that he took over the substantive post within weeks. In 1872, needing an improved income, he took up the post of Police Surgeon in Manchester, which he then held until 1882, meanwhile becoming a member of the Royal College of Physicians of London. In 1873, he was also appointed surgeon to St Mary's Hospital for Women in Manchester. Wanting to develop an academic component to his police work, in 1879 he was appointed lecturer in medical jurisprudence at Owens College (founded in 1851, subsequently merging with the federal Victoria University, which in 1903–4 split into the Universities of Manchester, Leeds, and Liverpool) and took a Doctor of Medicine (MD) degree at Durham University. Because of his interests in obstetrics and gynaecology, he was appointed to the chair of obstetric medicine at Owens College in 1885. While in Manchester, he was honorary librarian and secretary to the Manchester Medical Society. Having developed a large and lucrative private practice, and established himself as a senior academic within the North of England, in 1888 he was persuaded to take up the post of obstetric physician to St Thomas’ Hospital in London. It was here that he did his most important research, studying the pathology of pelvic inflammation, and its relationship with ectopic pregnancy. He published his book ‘Diseases of the Fallopian Tubes’ in 1895. He championed the admission of women to the medical register, the registration and training of midwives, and popularised the work of Oliver Wendell Holmes on puerperal fever (Holmes, like Semmelweiss, attributed it to inadequate antisepsis). He wrote many papers in major medical journals, and was fond of quoting Tennyson and Browning. A keen supporter of the establishment of our journal, it was entirely appropriate for him to become editor in 1906, although he had by then already been suffering angina for 6 years. He died of a heart attack in May 1908. Happily married to Emily Mary Freeman, with one daughter, he was widely liked and admired by his colleagues for being a ‘willing slave to the dictates of his conscience’. In a letter to the Debating Society at Leeds, he declared that only putting the patients’ needs above financial considerations could ‘raise the medical life out of the category of the sordid and self-seeking into that of the unselfish and ennobling’. Philip Steer is Emeritus Editor, BJOG. For a full disclosure of interests, please go to www.BJOG.org. Photo source: reproduced from BMJ, 1908;1:1269 with permission from BMJ Publishing Group Ltd.

Fotoetnografía educativa: una ruta para comprender la cultura corporal escolarizada

Las imágenes icónicas y los ambientes educacionales observados desde la antropología y la estética cotidiana educativa presentan un amplio campo cultural, semántico y sensible que permite aproximaciones comprensivas a la cultura educativa y escolar. La fotografía, a partir de su desarrollo tecnológico y su transformación en herramienta masiva, se consolida como fuente de información visual y de indagación perceptual de gran utilidad para la investigación etnográfica educativa. En el presente artículo, el autor, a partir de una experiencia de investigación realizada con este medio (Moreno 2005, 2007, 2009a, 2009b, 2010; Moreno y otros 2012), presenta una perspectiva metodológica sobre las posibilidades que ofrecen la fuente fotográfica y la investigación fotoetnográfica para el amplio campo de la educación corporal, en este caso para la descripción y comprensión del proceso de intervención pedagógica de lo corporal

An Increase in Productivity

Oceanography![Figure][1] CREDIT: IMAGE ENHANCED (PHOTO SOURCE) © LEE THOMAS/ALAMY One of the most dramatic consequences of recent global warming has been the rapid and large reduction of summertime sea ice in the Arctic Ocean. The seasonal disappearance of so much ice exposed huge expanses of the ocean that were previously covered, and creates the possibility for greater marine productivity in the regions newly exposed to sunlight. Solar irradiation alone is not sufficient to cause increased biological productivity, of course: There also must be an adequate supply of nutrients to fuel it. Tremblay et al. used a combination of in situ and remote observations to show that new productivity in the Arctic coastal Beaufort Sea has increased because of climate warming there, and that the nutrients needed to fuel that new production are derived from deep waters that have upwelled in response to the stronger winds and reductions in summertime sea-ice coverage caused by climate change. Further increases in the amounts of new production can be expected as increasingly deep and frequent seaward retreat of the ice pack and stronger winds occur. Geophys. Res. Lett. 38, L18604 (2011). [1]: pending:yes

광반응 반응기 내부의 에너지 분포와 라디칼 생성에 대한 연구

본 연구에서는 광 반응기 내부의 영향반경을 평가하기 위해 자외선(UV-C) 램프의 강도와 photochemical에 의한 OH 라디칼 생성량을 측정하였다. 또한 <TEX>$TiO_2$</TEX> (Degussa P-25)를 농도별로 첨가하여 자외선 램프의 영향반경을 측정하였다. 광 반응기는 아크릴 재질의 bath 타입을 사용하였고, 254 nm의 파장을 가진 UV-C 자외선 램프를(SANKYO DENKI, 지름 : 2.2 cm, 길이 : 18.5 cm) 사용하였다. 램프의 소비전력은 10.5 W이고, OH 라디칼 생성량을 측정하기 위해 KI dosimetry를 사용하였다. 실험 결과로부터 광 반응기에서 자외선의 강도가 0.367 mW/<TEX>$cm^2$</TEX>이상 조사되어야하고, 거리는 13 cm 이내에서 OH 라디칼 생성에 영향을 미치는 것으로 나타났다. 또한 광촉매 반응기에서는 촉매의 농도로 인해 자외선의 영향반경이 매우 감소하는 것을 확인할 수 있었다. In this study, photochemical effects (OH radical formation) in the photoreactor was investigated to analyze UV-C intensity distribution. In addition, The influence radius of the UV-C lamp was measured at various dose of <TEX>$TiO_2$</TEX> (Degussa P-25). The photoreactor used in this study was bath type reactor which is made by acrylic and the UV-C lamp (SANKYO DENKI, wavelength : 254 nm, Diameter : 2.2 cm, Length : 18.5 cm) was used as photo source. The maximum electric power consumption of the UV lamp was 10.5 W. The OH radical formation by UV-C was measured by KI dosimetry methods. From the results, the effective OH radical formation was occurred under the following condition. The reasonable distance of UV-C lamp is within 13 cm and the intensity of UV-C lamp should be more than 0.367 mW/<TEX>$cm^2$</TEX>. Moreover, the concentration of catalyst affects on the influence radius of the UV lamp.

A photochemical source of peroxypropionic and peroxyisobutanoic nitric anhydride

Abstract A method to photochemically generate stable outputs of peroxyacetic, peroxypropionic, or peroxyisobutanoic nitric anhydride (PAN, PPN, or PiBN) in dilute gas streams is described. The PANs are generated by photolysis of excess acetone, diethyl ketone, or diisopropyl ketone in the presence of oxygen and either nitric oxide or nitrogen dioxide. The source output was characterized using a commercial NOy monitor, an in-house constructed thermal dissociation cavity ring-down spectrometer (TD-CRDS) equipped with a heated inlet for quantification of NO2, total peroxyacyl nitrates (∑PAN), and total alkyl nitrates (∑AN), and a thermal dissociation chemical ionization mass spectrometer (TD-CIMS) operated with iodide reagent ion. The TD-CIMS was calibrated (against TD-CRDS) using diffusion sources containing synthetic PAN standards. Response factors of 21, 19, and 5 counts per pptv, normalized to 1 million counts of iodide reagent ion, were found for PAN (monitored at m/z 59), PPN (m/z 73), and PiBN (m/z 87), respectively. The photo source was found to generate the three PANs in high yield. CIMS response factors derived using the photo source and TD-CRDS were identical to those derived from synthetic standards for PAN and PPN; hence, the photochemical PAN and PPN sources may be used to calibrate TD-CIMS (against TD-CRDS). For PiBN, the response factor derived using the photo source was 60% larger than that derived using the synthetic standard, limiting its use to deliver a calibrated stream of PiBN.

In Memoriam Alston Barrington "Barry" Chevannes (1940-2010)

In Memoriam Alston Barrington "Barry" Chevannes (1940-2010) A. Lynn Bolles (bio) Click for larger view View full resolution Photo source: The University of the West Indies. Barry Chevannes joined the ancestors November 5, 2010 as his family and friends did all they could for him as he battled for his life. His legacy is worthy of emulation by all as he will forever be known for his life's work as an anthropologist, political activist, and spiritual healer through music, kindness and love. He was an uptown/downtown interlocutor and an outstanding citizen who brought the best out of every person with whom he met. His love of Jamaica, of the Caribbean, of peoples of African descent and his commitment to understanding the global human condition was reflected in his writings, his politics, his leadership skills and relentless efforts to ease and interpret the pain and behaviors of others as they grappled with the social inequalities experienced in their daily lives due to their race, gender, class, religion and impoverishment. Barry Chevannes's academic and activist work provides us with explanatory tools to understand surviving and for seeking liberation. Born in rural St. Catherine Parish, Jamaica, Barry was third of nine children of parents who were small storeowners. To continue his education, he boarded out in downtown Kingston where he was a student at the all boys St. George's College, a Jesuit secondary school for classical and scientific learning. There, Chevannes developed his passion for learning, teaching, a love of Latin and a deepened faith in Roman Catholicism. In 1959, his faith and conviction led him to Shadowbrook, a Jesuit seminary in the Berkshires Mountains of Massachusetts. In 1965, while a seminarian, Barry Chevennes received his Bachelors degree in philosophy and a year later a second degree in the classics—Ancient Greek and Latin from Boston College, a Jesuit university in Boston. He returned to Jamaica and taught at Campion College, co-ed Jesuit high [End Page 145] school for a few years, but was unsettled as he acknowledged the social and economic inequality in Kingston. His experiences in Roxbury Massachusetts, the black neighborhood of Boston and overall US civil rights movement brought him a new political consciousness. Back in Jamaica, this racial, political and social awareness appeared in the folk songs he composed for church and community gatherings gave spiritual uplift and evoked liberation, social justice and human rights for those who sang the lyrics accompanied by Barry on his guitar. At the same time, the black consciousness movement and the University of the West Indies campus protests against the deportation of revolutionary Guyanese historian Walter Rodney coalesced with Barry Chevannes political fervor. Those days also marked when he left the priesthood, married Pauletta, became a proud father of two daughters and became a radically conscious writer and activist. In the early 1970s, Chevannes studied sociology at UWI and was drawn to the elder leaders of some of Jamaica's Rastafarian groups he identified as a African-Caribbean religion. His research, interviewing skills and writing about Rasta beliefs, politics and worldview led him to another educational opportunity in the US when he received a scholarship to study social and cultural anthropology at Columbia University. It would be years before the dissertation was completed and later still when his outstanding book resulting from that graduate research Rastafari: Roots and Ideology (1995) and then Rastafari and Other African Caribbean Worldviews (1998) would appear. Recognized as a top scholar on socio-religious movements in the region, Barry Chevannes writes of Rastafari in a unique, historical, holistic and religious context, "Rastafari (grew) from an obscure colonial origin (to) spread its influence among Black people all over the world (1998:xvi). These works blended all of Chevannes's worldviews as two historical, ethnographic, spiritual, and philosophic texts. In the mid 1970s, the "revo" movement took hold of the electorate and the governments of Jamaica, Grenada and Guyana. The transformation of society held social justice as precedent and subsequent legislation was passed to ease the pain of centuries of social and economic inequality. These efforts were put forth by the radical politics of these countries. The Workers' Party of Jamaica (WPJ), a socialist...