Influence of the strong metal support interaction effect (SMSI) of Pt/TiO2 and Pd/TiO2 systems in the photocatalytic biohydrogen production from glucose solution

Two different catalysts consisting of Pt/TiO2 and Pd/TiO 2 were submitted to diverse oxidative and reductive calcination treatments and tested for photocatalytic reforming of glucose water solution (as a model of biomass component) in H2 production. Oxidation and reduction at 850°C resulted in better photocatalysts for hydrogen production than Degussa P-25 and the ones prepared at 500°C, despite the fact that the former consisted in very low surface area (6-8 m2/g) rutile titania specimens. The platinum-containing systems prepared at 850°C give the most effective catalysts. XPS characterization of the systems showed that thermal treatment at 850°C resulted in electron transfer from titania to metal particles through the so-called strong metal-support interaction (SMSI) effect. Furthermore, the greater the SMSI effect, the better the catalytic performance. Improvement in photocatalytic behavior is explained in terms of avoidance of electron-hole recombination through the electron transfer from titania to metal particles

An absolute calibration system for millimeter-accuracy APOLLO measurements

Lunar laser ranging provides a number of leading experimental tests of gravitation -- important in our quest to unify General Relativity and the Standard Model of physics. The Apache Point Observatory Lunar Laser-ranging Operation (APOLLO) has for years achieved median range precision at the ~2 mm level. Yet residuals in model-measurement comparisons are an order-of-magnitude larger, raising the question of whether the ranging data are not nearly as accurate as they are precise, or if the models are incomplete or ill-conditioned. This paper describes a new absolute calibration system (ACS) intended both as a tool for exposing and eliminating sources of systematic error, and also as a means to directly calibrate ranging data in-situ. The system consists of a high-repetition-rate (80 MHz) laser emitting short (< 10 ps) pulses that are locked to a cesium clock. In essence, the ACS delivers photons to the APOLLO detector at exquisitely well-defined time intervals as a "truth" input against which APOLLO's timing performance may be judged and corrected. Preliminary analysis indicates no inaccuracies in APOLLO data beyond the ~3 mm level, suggesting that historical APOLLO data are of high quality and motivating continued work on model capabilities. The ACS provides the means to deliver APOLLO data both accurate and precise below the 2 mm level.Comment: 21 pages, 10 figures, submitted to Classical and Quantum Gravit

Facile mechanochemical modification of g-C3N4 for selective photo-oxidation of benzyl alcohol

Graphitic carbon nitride enriched with ZnO or Fe2O3 were synthesized using a simple one-pot mechanochemical method. By using this method, composite samples were synthetized without the production of any potentially hazardous waste. The synthesized materials were used as catalysts during the selective photo-oxidation of benzyl alcohol. Both composite materials displayed an enhancement of the activity and benzaldehyde selectivity with respect to the pure g-C3N4. The most active catalyst was Fe2O3/g-C3N4. The conversion and benzaldehyde selectivity of this sample were 20 and 70 %, respectively. It showed a considerable increase of the benzaldehyde selectivity compared to the pure g-C3N4 and TiO2 P25 commercial reference. A complete structural and electronic characterization using Scanning Electron Microscopy-Energy Dispersive (SEM-EDX), BET measurements, X-ray diffraction (XRD), X-ray Photoelectron (XPS), and UV–visible spectroscopies was carried out. The characterization analysis pointed out the leading role of the crystallinity and surface concentration over the activity and benzaldehyde selectivity of the reactio

Towards Rechargeable Zinc-Air Batteries with Aqueous Chloride Electrolytes

This paper presents a combined theoretical and experimental investigation of aqueous near-neutral electrolytes based on chloride salts for rechargeable zinc-air batteries (ZABs). The resilience of near-neutral chloride electrolytes in air could extend ZAB lifetime, but theory-based simulations predict that such electrolytes are vulnerable to other challenges including pH instability and the unwanted precipitation of mixed zinc hydroxide chloride products. In this work, we combine theory-based simulations with experimental methods such as full cell cycling, operando pH measurements, ex-situ XRD, SEM, and EDS characterization to investigate the performance of ZABs with aqueous chloride electrolytes. The experimental characterization of near-neutral ZAB cells observes the predicted pH instability and confirms the composition of the final discharge products. Steps to promote greater pH stability and control the precipitation of discharge products are proposed.Comment: 13 pages, 12 figure

Global Antifungal Profile Optimization of Chlorophenyl Derivatives against Botrytis cinerea and Colletotrichum gloeosporioides

Twenty-two aromatic derivatives bearing a chlorine atom and a different chain in the para or meta position were prepared and evaluated for their in vitro antifungal activity against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. The results showed that maximum inhibition of the growth of these fungi was exhibited for enantiomers S and R of 1-(40-chlorophenyl)- 2-phenylethanol (3 and 4). Furthermore, their antifungal activity showed a clear structure-activity relationship (SAR) trend confirming the importance of the benzyl hydroxyl group in the inhibitory mechanism of the compounds studied. Additionally, a multiobjective optimization study of the global antifungal profile of chlorophenyl derivatives was conducted in order to establish a rational strategy for the filtering of new fungicide candidates from combinatorial libraries. The MOOPDESIRE methodology was used for this purpose providing reliable ranking models that can be used later

Depression symptoms and mortality in elderly peruvian navy veterans: a retrospective cohort study

Abstract: Our study was design to determine the association between depressive symptoms and mortality in adults over 60 years old Navy Peruvian Veterans. We performed a retrospective cohort study based on a previous cohort study. A total of 1681 patients over 60 years old were included between 2010–2015. Demographic information, self-reported information about falls, physical frailty assessment, tobacco consumption, hypertension, Type 2 Diabetes Mellitus, Chronic Obstructive Pulmonary Disease and was collected. Depression was assessed by the short form of the Geriatric Depression Scale. We found that depressive symptoms were present in 24.9% of the participants and 40.5% of them died. Mortality risk in patients with depressive symptoms, physical frailty, and male sex was: RR of 23.1 (95% CI: 11.7–45.7), 3.84 (95% CI: 2.16–6.82), and 1.37 (95% CI: 1.07–1.75) respectively. We concluded that depressive symptoms in Peruvian retired military personnel and their immediate relatives are high and are significatively associated with mortality. Also, being male and frail was associated with an increased risk of death. This reinforces that early detection and assessment of depressive symptoms could be an opportunity to improve the health status of older adults

PENGARUH MEDIA PEMBELAJARAN EDMODO TERHADAP HASIL BELAJAR SISWA DI SMA PASUNDAN 2 BANDUNG (Studi Eksperimen pada Mata Pelajaran Ekonomi Materi Pokok BUMN dan BUMD di Kelas Lintas Minat X MIPA 5 Tahun Ajaran 2017/2018)

Penelitian ini berjudul: Pengaruh Media Pembelajaran Edmodo terhadap Hasil Belajar Siswa di SMA Pasundan 2 Bandung. Tujuan dari penelitian ini adalah: (i) untuk mengetahui bagaimana hasil belajar siswa sebelum diterapkannya media pembelajaran Edmodo (pretest), (ii) untuk mengetahui bagaimana hasil belajar siswa setelah diterapkannya media pembelajaran Edmodo (posttest), (iii) untuk mengetahui perbedaan hasil belajar siswa pada pengukuran awal (pretest) dan pengukuran akhir (posttest), dan (iv) untuk mengetahui seberapa besar pengaruh media pembelajaran Edmodo terhadap hasil belajar siswa pada kelas lintas minat X MIPA 5 di SMA Pasundan 2 Bandung. Metode yang digunakan dalam penelitian ini adalah pra-eksperimen dengan desain penelitian one-group pretest-posttest. Sampel penelitian ini adalah seluruh siswa kelas lintas minat X MIPA 5 SMA Pasundan 2 Bandung. Instrumen penelitian yang digunakan berupa tes. Tes yang digunakan berupa pilihan ganda (pretest dan posttest) dan telah diuji validitas serta reliabilitasnya. Berdasarkan data hasil nilai rata -rata pretest dan posttest diketahui N-Gain sebesar 0,70 dengan interpretasi tinggi, dan diperoleh kesimpulan bahwa terdapat perbedaan hasil belajar siswa sebelum dan setelah penerapan media pembelajaran Edmodo. Pembelajaran menggunakan media Edmodo memberikan pengaruh terhadap hasil belajar siswa kelas lintas minat X MIPA 5 sebesar 27,2% dengan interpretasi cukup. Pengaruh lainnya sebesar 72,8%. Hal ini dapat dipengaruhi oleh beberapa faktor yaitu motivasi, kompetensi guru, lingkungan, dan model pembelajaran. Sebagai penutup, penulis menyampaikan saran sebaiknya guru menggunakan media pembelajaran yang beragam. Salah satunya menggunakan media pembelajaran Edmodo, karena media tersebut dapat meningkatkan hasil belajar siswa. Kata Kunci: Media Pembelajaran, Edmodo, Hasil Belaja

First positron annihilation lifetime measurement of Pu

We have made the first measurement of defects in an aged sample of {delta} phase, Ga stabilized Pu, using positron annihilation lifetime spectroscopy. This measurement validates the procedure necessary to perform measurements on this highly toxic material and obtain data representative of sample conditions. Comparison of the positron annihilation lifetime analysis of the data with calculated values suggests that He filled vacancies or vacancy clusters dominate the defect population. Such defects are the necessary precursor to void growth and swelling. The evolution of defects resulting from the radioactive decay of Pu during its life in the stockpile is one of the unknown quantities affecting our confidence in predictions of the limit on stockpile components. Radiation damage leads to changes in the size and strength of metals studied for reactor and accelerator use and similar effects may be expected in Pu. The evolution of radiation produced vacancies into larger void structures and accompanying macroscopic swelling may occur in Pu at some age. A detailed understanding of the defects in self irradiated Pu is required to predict the time scale of void swelling and related radiation effects. 1 fig

Self-Medication Practices, Use of Brand-Name, and Over-the-Counter Medicines by Peruvian Older Adults

Background Older adults are a particularly vulnerable group to drug use and self-medication. The aim of the study was to evaluate self-medication as a factor associated with the purchase of brand-name and over-the-counter (OTC) drugs in older adults in Peru. Methods A secondary analysis was performed using an analytical cross-sectional design of data from a nationally representative survey from 2014 to 2016. The exposure variable was self-medication, defined as the purchase of medicines without a prescription. The dependent variables were purchases of brand-name and OTC drugs, both as a dichotomous response (yes/no). Information of sociodemographic variables, health insurance, and the types of drugs purchased by the participants was collected. Crude prevalence ratios (PR) were calculated and adjusted using generalized linear models of the Poisson family, considering the complex sample of the survey. Results In this study, 1,115 respondents were evaluated, with a mean age of 63.8 years and a male proportion of 48.2%. The prevalence of self-medication was 66.6%, while the proportions of purchases of brand-name and OTC drugs were 62.4% and 23.6%, respectively. The adjusted Poisson regression analysis revealed an association between self-medication and the purchase of brand-name drugs (adjusted PR [aPR]=1.09; 95% confidence interval [CI]: 1.01–1.19). Likewise, self-medication was associated with the purchase of OTC medications (aPR=1.97; 95%CI: 1.55–2.51). Conclusions This study evidenced a high prevalence of self-medication in Peruvian older adults. Two-thirds of the surveyed people bought brand-name drugs, whereas one-quarter bought OTC drugs. Self-medication was associated with a greater likelihood of buying brand-name and OTC drugs