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1.
J Quant Spectrosc Radiat Transf ; 186: 17-39, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32817995

RESUMO

TEMPO was selected in 2012 by NASA as the first Earth Venture Instrument, for launch between 2018 and 2021. It will measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO observes from Mexico City, Cuba, and the Bahamas to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution (~2.1 km N/S×4.4 km E/W at 36.5°N, 100°W). TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry, as well as contributing to carbon cycle knowledge. Measurements are made hourly from geostationary (GEO) orbit, to capture the high variability present in the diurnal cycle of emissions and chemistry that are unobservable from current low-Earth orbit (LEO) satellites that measure once per day. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies. TEMPO takes advantage of a commercial GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), formaldehyde (H2CO), glyoxal (C2H2O2), bromine monoxide (BrO), IO (iodine monoxide),water vapor, aerosols, cloud parameters, ultraviolet radiation, and foliage properties. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides these near-real-time air quality products that will be made publicly available. TEMPO will launch at a prime time to be the North American component of the global geostationary constellation of pollution monitoring together with the European Sentinel-4 (S4) and Korean Geostationary Environment Monitoring Spectrometer (GEMS) instruments.

2.
Mycotoxin Res ; 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39264500

RESUMO

Globally, maize (Zea mays L.) is deemed an important cereal that serves as a staple food and feed for humans and animals, respectively. Across the East African Community, maize is the staple food responsible for providing over one-third of calories in diets. Ideally, stored maize functions as man-made grain ecosystems, with nutritive quality changes influenced predominantly by chemical, biological, and physical factors. Food spoilage and fungal contamination are convergent reasons that contribute to the exacerbation of mycotoxins prevalence, particularly when storage conditions have deteriorated. In Kenya, aflatoxins are known to be endemic with the 2004 acute aflatoxicosis outbreak being described as one of the most ravaging epidemics in the history of human mycotoxin poisoning. In Tanzania, the worst aflatoxin outbreak occurred in 2016 with case fatalities reaching 50%. Similar cases of aflatoxicoses have also been reported in Uganda, scenarios that depict the severity of mycotoxin contamination across this region. Rwanda, Burundi, and South Sudan seemingly have minimal occurrences and fatalities of aflatoxicoses and aflatoxin contamination. Low diet diversity tends to aggravate human exposure to aflatoxins since maize, as a dietetic staple, is highly aflatoxin-prone. In light of this, it becomes imperative to formulate and develop workable control frameworks that can be embraced in minimizing aflatoxin contamination throughout the food chain. This review evaluates the scope and magnitude of aflatoxin contamination in post-harvest maize and climate susceptibility within an East African Community context. The paper also treats the potential green control strategies against Aspergillus spoilage including biocontrol-prophylactic handling for better and durable maize production.

3.
Rev Sci Instrum ; 93(7): 073303, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35922315

RESUMO

The 300 kV DC high voltage photogun at Jefferson Lab was redesigned to deliver electron beams with a much higher bunch charge and improved beam properties. The original design provided only a modest longitudinal electric field (Ez) at the photocathode, which limited the achievable extracted bunch charge. To reach the bunch charge goal of approximately few nC with 75 ps full-width at half-maximum Gaussian laser pulse width, the existing DC high voltage photogun electrodes and anode-cathode gap were modified to increase Ez at the photocathode. In addition, the anode aperture was spatially shifted with respect to the beamline longitudinal axis to minimize the beam deflection introduced by the non-symmetric nature of the inverted insulator photogun design. We present the electrostatic design of the original photogun and the modified photogun and beam dynamics simulations that predict vastly improved performance. We also quantify the impact of the photocathode recess on beam quality, where recess describes the actual location of the photocathode inside the photogun cathode electrode relative to the intended location. A photocathode unintentionally recessed/misplaced by sub-millimeter distance can significantly impact the downstream beam size.

4.
Int J Biol Macromol ; 158: 231-243, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32344086

RESUMO

A new Schiff base of chitosan, namely Piperonal-chitosan (Pip-Cht), was synthesized for the first time, using a microwave irradiation method and characterized using spectroscopic techniques. The corrosion inhibition behavior of the new Schiff base was evaluated on carbon steel in 15% HCl medium via gravimetric and electrochemical techniques. This is the first work on the application of chemically functionalized chitosan as a corrosion inhibitor in the oil-well acidizing environment. The Pip-Cht inhibitor exhibited a high corrosion inhibition efficiency of 85.16% at a moderate dose of 600 mg L-1. Further, the addition of potassium iodide as a synergistic agent to the corrosive electrolyte produced a significant improvement in the inhibition efficiency to 91.15% at a low dosage of 10 mM of KI. At a higher temperature of 65 °C, the combination of both the inhibitor and KI yielded a high inhibition efficiency. The results of the gravimetric and electrochemical experiments were corroborated using AFM and SEM studies. The DFT calculations indicated that corrosion inhibition behavior of the Schiff base mainly occurs in the protonated form.

5.
Phys Rev Lett ; 84(15): 3265-9, 2000 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-11019066

RESUMO

We have measured the cross section for quasielastic 1p-shell proton knockout in the 16O(e,e(')p) reaction at omega = 0.439 GeV and Q2 = 0.8 (GeV/c)(2) for missing momentum P(miss)

6.
Acta Psychol (Amst) ; 108(1): 53-71, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11485193

RESUMO

Judgment-by-outcomes denotes basing retrospective evaluation of decisions on the valence of their outcomes (success versus failure). Although decisions are typically evaluated in social contexts, so far judgment-by-outcomes has been studied without regard to this context. This study examines the moderating effect of evaluator's identification with the decision maker (the one-of-us-effect) on the influence of outcome information on the evaluation of Arab and Jewish subjects were presented with two cases recounting operations by either Arab or Jewish underground directed against the British authorities in Palestine. One case was a success (from the underground's point of view) and one ended in failure. Consistent with the one-of-us effect, identification with the decision maker variably canceled the influence of outcome information altogether, accentuated or weakened its influence, or determined which outcome constituted successful and unsuccessful outcomes. The one-of-us effect exercised a differential influence over different facets of decision evaluation, influencing most strongly the assignment of sanctions (in-group decision makers were mostly rewarded, out-group decision-makers were mostly punished regardless of outcomes). Next, in order of potency, the effect influenced the evaluation of decision justification, the evaluation of the decision maker, and the evaluation of the quality of decision process.


Assuntos
Cognição , Tomada de Decisões , Conhecimento Psicológico de Resultados , Princípios Morais , Identificação Social , Adolescente , Árabes/psicologia , Feminino , Humanos , Israel , Judeus/psicologia , Masculino
7.
Br J Soc Psychol ; 29 ( Pt 1): 67-77, 1990 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2322783

RESUMO

Relationships between exposure to political hardships, social-economic status and mother's psychological responses, and children's coping modes, were analysed among 66 Palestinian boys and girls aged 8-14 who lived in the West Bank and the Gaza Strip. The effectiveness of children's coping modes in protecting their mental health from the negative impact of political hardships was also analysed. The coping modes were assessed on the intentional (passive-active), cognitive (defensive-purposive), and emotional (helpless-courageous) levels. The results showed that the more children were exposed to political hardships, the more they employed active and courageous coping modes. Furthermore, the more mothers showed psychological symptoms the more their children used active coping modes. The more political activity the mothers used as a coping mode, the more their children used purposive coping. Exposure to political hardships increased children's psychological symptoms, and none of the children's psychological coping modes were effective in mitigating this relationship.


Assuntos
Adaptação Psicológica , Política , Refugiados/psicologia , Violência , Guerra , Adolescente , Ansiedade/psicologia , Criança , Feminino , Humanos , Controle Interno-Externo , Masculino , Relações Mãe-Filho
8.
Sci Total Environ ; 499: 107-13, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25181042

RESUMO

Waterpipe smoking is becoming increasingly popular worldwide. Research has shown that cigarette smoke, in addition to hundreds of carcinogenic and otherwise toxic compounds, may also contain compounds of microbiological origin. In the present study we analyzed waterpipe smoke for some microbial compounds. Both of the two markers studied, viz 3-hydroxy fatty acids of bacterial lipopolysaccharide (LPS) and ergosterol of fungal biomass, were found in waterpipe tobacco, in amounts similar as previously found in cigarette tobacco, and in smoke. Waterpipe mainstream smoke contained on average 1800 pmol LPS and 84.4 ng ergosterol produced per session. An average concentration of 2.8 pmol/m(3) of LPS was found in second hand smoke during a 1-2-h waterpipe smoking session while ergosterol was not detected; corresponding concentrations from smoking five cigarettes were 22.2 pmol/m(3) of LPS and 87.5 ng/m(3) of ergosterol. This is the first time that waterpipe smoking has been shown to create a bioaerosol. In the present study we also found that waterpipe smoking generated several polycyclic aromatic hydrocarbons, carbon monoxide, and high fraction of small (<200 nm) particles that may have adverse effects on human health upon inhalation.


Assuntos
Produtos do Tabaco/análise , Monóxido de Carbono/análise , Ergosterol/análise , Lipopolissacarídeos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Produtos do Tabaco/microbiologia , Poluição por Fumaça de Tabaco/análise , Poluição por Fumaça de Tabaco/estatística & dados numéricos , Microbiologia da Água
9.
Phys Rev Lett ; 94(15): 152001, 2005 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-15904134

RESUMO

We report on a measurement of the parity violating asymmetry in the elastic scattering of polarized electrons off unpolarized protons with the A4 apparatus at MAMI in Mainz at a four momentum transfer value of Q(2)=0.108 (GeV/c)(2) and at a forward electron scattering angle of 30 degrees p)=[-1.36+/-0.29(stat)+/-0.13(syst)]x10(-6). The expectation from the standard model assuming no strangeness contribution to the vector current is A(0)=(-2.06+/-0.14)x10(-6). We have improved the statistical accuracy by a factor of 3 as compared to our previous measurements at a higher Q2. We have extracted the strangeness contribution to the electromagnetic form factors from our data to be G(s)(E)+0.106G(s)(M)=0.071+/-0.036 at Q(2)=0.108 (GeV/c)(2). We again find the value for G(s)(E)+0.106G(s)(M) to be positive, this time at an improved significance level of two sigma.

10.
Phys Rev Lett ; 94(8): 082001, 2005 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-15783877

RESUMO

We report on a measurement of the asymmetry in the scattering of transversely polarized electrons off unpolarized protons, A( perpendicular), at two Q2 values of 0.106 and 0.230 (GeV/c)(2) and a scattering angle of 30 degrees

11.
Phys Rev Lett ; 93(2): 022002, 2004 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-15323904

RESUMO

We report on a measurement of the parity-violating asymmetry in the scattering of longitudinally polarized electrons on unpolarized protons at a Q2 of 0.230 (GeV/c)(2) and a scattering angle of theta (e) = 30 degrees - 40 degrees. Using a large acceptance fast PbF2 calorimeter with a solid angle of delta omega = 0.62 sr, the A4 experiment is the first parity violation experiment to count individual scattering events. The measured asymmetry is A(phys)=(-5.44+/-0.54(stat)+/-0.26(sys))x10(-6). The standard model expectation assuming no strangeness contributions to the vector form factors is A(0) = (-6.30+/-0.43) x 10(-6). The difference is a direct measurement of the strangeness contribution to the vector form factors of the proton. The extracted value is G(s)(E) + 0.225G(s)(M) = 0.039+/-0.034 or F(s)(1) + 0.130F(s)(2) = 0.032+/-0.028.

12.
Phys Rev Lett ; 89(6): 062301, 2002 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-12190578

RESUMO

The 2H(e,e(')p)n cross section was measured in Hall A of the Thomas Jefferson National Accelerator Facility near the top of the quasielastic peak (x(Bj)=0.964) at a four-momentum transfer squared, Q(2)=0.665 (GeV/c) (2) (omega=0.368 GeV, W=2.057 GeV), and for recoil momenta up to 550 MeV/c. The measured cross section deviates by 1-2sigma from a state-of-the-art calculation at low recoil momenta. At high recoil momenta the cross section is well described by the same calculation; however, in this region, final-state interactions and interaction currents are predicted to be large, and alternative choices of nucleon-nucleon potential and nucleon current operator may result in significant spread in the calculations.

13.
Phys Rev Lett ; 92(10): 102003, 2004 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-15089200

RESUMO

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2=0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51+/-0.57 (stat)+/-0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2=0.091 (GeV/c)2, which are also consistent with theoretical predictions.

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