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Redetermination of hydronium perchlorate at 193 and 293 K

Rahman AA, Usman A, Chantrapromma S, Fun HK

Acta Crystallogr C, 2003 Sep;59(Pt 9):i92-4.
PMID: 12944636

A sample of hydronium perchlorate, H(3)O(+) x ClO(4)(-), crystallized from ethanol at ambient temperature, was found to be orthorhombic (space group Pnma) at both 193 and 293 K, with no phase transition observed in this temperature range. This contrasts with the earlier observation [Nordman (1962). Acta Cryst. 15, 18-23] of a monoclinic phase (space group P2(1)/n) at 193 K for crystals grown at that temperature from perchloric acid. The hydronium and perchlorate ions lie across a mirror plane but it is not possible to define at either temperature a simple description of the H-atom positions due to the three-dimensional tumbling of the hydronium cation.

Matched MeSH terms: Aircraft
Fulltext Production of talc nanosheets via fine grinding and sonication processes

Palaniandy, Samayamutthirian, Noorina Hidayu Jamil, Khairun Azizi Mohd Azizli, Syed Fuad Saiyid Hashim, Hashim Hussin

Journal of Nuclear and Related Technologies, 2009;2009(1):255-265.
MyJurnal

Fine grinding of high purity talc in jet mill at low grinding pressure was carried out by varying the feed rate and classifier rotational speed. These ground particles were sonicated in laboratory ultrasonic bath by varying the soniction period at five levels. The ground and sonicated particles were characterized in terms of particle size and particle size distribution. Mechanochemical and sonochemical effect of talc was determine via X-ray diffraction. Particle shape and surface texture of the ground and sonicated product was determined via scanning electron microscope and transmission electron microscope. The ground particle size exhibited particle size below 10 µm with narrow size distribution. The reduction of peak intensity in (002) plane indicated the layered structure has been distorted. The sonicated talc shows that the thickness of the talc particles after the sonication process is 20 nm but the lateral particle size still remains in micron range. The reduction of the XRD peak intensity for (002) plane and thickness of sonicated talc as shown in SEM and TEM micrographs proves that fine grinding and sonication process produces talc nanosheets.

Matched MeSH terms: Aircraft
Fulltext Problems in the Malaysian Armed Forces (ATM) and its effects on Malaysia's national defense policy

Mohamad Faisol Keling, Mohamad Hanapi Mohamad

Malaysian Journal of Social Sciences and Humanities, 2016;1(3):66-82.
MyJurnal

Logistics development of Malaysian Armed Forces (ATM) involving the Malaysian Army (TDM),
Royal Malaysian Navy (RMN) and Royal Malaysian Air Force (RMAF) have been developed since
1957. Since the 1990s, ATM has been through the process of modernization which is can seen through
the rapid and strong capabilities in logistics aspect. Defense policy development has involved the
development of the logistical aspects of ATM. Purchasing of defense equipments such as the most
modern warship in Armed Force in 1990, Scorpene submarines, fighter aircraft which is used by the
developed countries such as the MiG-29, FA/18 Hornet and Sukhoi 30MKM, battle tanks from Poland
and so on with the transfer package technology is essential to ensure that the principle of self-reliance
defense ATM can be achieved. This process has force the government to allocate a large amount of
money in providing modern logistics equipments so it can be used to the maximum by the defense forces. In fact, the development of the defense and Malaysian Armed Forces (ATM) also growing
along with the development of technology, defense policy, doctrine of current world logistics. However
the logistics development has raised questions because of the capabilty of logistic and Malaysian
Armed Forces (ATM) itself which are caused various accidents and issues affecting ATM.

Matched MeSH terms: Aircraft
Fulltext Pneumocephalus and air travel: an experimental investigation on the effects of aircraft cabin pressure on intracranial pressure

Lim E, Lan BL, Ooi EH, Low HL

Sci Rep, 2020 08 12;10(1):13626.
PMID: 32788610 DOI: 10.1038/s41598-020-70614-w

This study investigates the effects of aircraft cabin pressure on intracranial pressure (ICP) elevation of a pneumocephalus patient. We propose an experimental setup that simulates the intracranial hydrodynamics of a pneumocephalus patient during flight. It consists of an acrylic box (skull), air-filled balloon [intracranial air (ICA)], water-filled balloon (cerebrospinal fluid and blood) and agarose gel (brain). The cabin was replicated using a custom-made pressure chamber. The setup can measure the rise in ICP during depressurization to levels similar to that inside the cabin at cruising altitude. ΔICP, i.e. the difference between mean cruising ICP and initial ICP, was found to increase with ICA volume and ROC. However, ΔICP was independent of the initial ICP. The largest ΔICP was 5 mmHg; obtained when ICA volume and ROC were 20 ml and 1,600 ft/min, respectively. The postulated ICA expansion and the subsequent increase in ICP in pneumocephalus patients during flight were successfully quantified in a laboratory setting. Based on the quantitative and qualitative analyses of the results, an ICA volume of 20 ml and initial ICP of 15 mmHg were recommended as conservative thresholds that are required for safe air travel among pneumocephalus patients. This study provides laboratory data that may be used by doctors to advise post-neurosurgical patients if they can safely fly.

Matched MeSH terms: Aircraft*
Observation of tt[over ¯]H Production

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 Jun 08;120(23):231801.
PMID: 29932697 DOI: 10.1103/PhysRevLett.120.231801

The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of sqrt[s]=7, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and 35.9 fb^{-1}, respectively. The data were collected with the CMS detector at the CERN LHC. The results of statistically independent searches for Higgs bosons produced in conjunction with a top quark-antiquark pair and decaying to pairs of W bosons, Z bosons, photons, τ leptons, or bottom quark jets are combined to maximize sensitivity. An excess of events is observed, with a significance of 5.2 standard deviations, over the expectation from the background-only hypothesis. The corresponding expected significance from the standard model for a Higgs boson mass of 125.09 GeV is 4.2 standard deviations. The combined best fit signal strength normalized to the standard model prediction is 1.26_{-0.26}^{+0.31}.

Matched MeSH terms: Aircraft
Observation of the Production of Three Massive Gauge Bosons at sqrt[s]=13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2020 Oct 09;125(15):151802.
PMID: 33095594 DOI: 10.1103/PhysRevLett.125.151802

The first observation is reported of the combined production of three massive gauge bosons (VVV with V=W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV. The analysis is based on a data sample recorded by the CMS experiment at the CERN LHC corresponding to an integrated luminosity of 137 fb^{-1}. The searches for individual WWW, WWZ, WZZ, and ZZZ production are performed in final states with three, four, five, and six leptons (electrons or muons), or with two same-sign leptons plus one or two jets. The observed (expected) significance of the combined VVV production signal is 5.7 (5.9) standard deviations and the corresponding measured cross section relative to the standard model prediction is 1.02_{-0.23}^{+0.26}. The significances of the individual WWW and WWZ production are 3.3 and 3.4 standard deviations, respectively. Measured production cross sections for the individual triboson processes are also reported.

Matched MeSH terms: Aircraft
Observation of Top Quark Production in Proton-Nucleus Collisions

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2017 Dec 15;119(24):242001.
PMID: 29286735 DOI: 10.1103/PhysRevLett.119.242001

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb^{-1}. The significance of the tt[over ¯] signal against the background-only hypothesis is above 5 standard deviations. The measured cross section is σ_{tt[over ¯]}=45±8 nb, consistent with predictions from perturbative quantum chromodynamics.

Matched MeSH terms: Aircraft
Observation of Single Top Quark Production in Association with a Z Boson in Proton-Proton Collisions at sqrt[s]=13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2019 Apr 05;122(13):132003.
PMID: 31012605 DOI: 10.1103/PhysRevLett.122.132003

The observation of single top quark production in association with a Z boson and a quark (tZq) is reported. Events from proton-proton collisions at a center-of-mass energy of 13 TeV containing three charged leptons (either electrons or muons) and at least two jets are analyzed. The data were collected with the CMS detector in 2016 and 2017 and correspond to an integrated luminosity of 77.4fb^{-1}. The increased integrated luminosity, a multivariate lepton identification, and a redesigned analysis strategy improve significantly the sensitivity of the analysis compared to previous searches for tZq production. The tZq signal is observed with a significance well over 5 standard deviations. The measured tZq production cross section is σ(pp→tZq→tℓ^{+}ℓ^{-}q)=111±13(stat)_{-9}^{+11}(syst) fb, for dilepton invariant masses above 30 GeV, in agreement with the standard model expectation.

Matched MeSH terms: Aircraft
Observation of Higgs Boson Decay to Bottom Quarks

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2018 Sep 21;121(12):121801.
PMID: 30296133 DOI: 10.1103/PhysRevLett.121.121801

The observation of the standard model (SM) Higgs boson decay to a pair of bottom quarks is presented. The main contribution to this result is from processes in which Higgs bosons are produced in association with a W or Z boson (VH), and are searched for in final states including 0, 1, or 2 charged leptons and two identified bottom quark jets. The results from the measurement of these processes in a data sample recorded by the CMS experiment in 2017, comprising 41.3 fb^{-1} of proton-proton collisions at sqrt[s]=13 TeV, are described. When combined with previous VH measurements using data collected at sqrt[s]=7, 8, and 13 TeV, an excess of events is observed at m_{H}=125 GeV with a significance of 4.8 standard deviations, where the expectation for the SM Higgs boson is 4.9. The corresponding measured signal strength is 1.01±0.22. The combination of this result with searches by the CMS experiment for H→bb[over ¯] in other production processes yields an observed (expected) significance of 5.6 (5.5) standard deviations and a signal strength of 1.04±0.20.

Matched MeSH terms: Aircraft
Fulltext Nitrogen management is essential to prevent tropical oil palm plantations from causing ground-level ozone pollution

Hewitt CN, MacKenzie AR, Di Carlo P, Di Marco CF, Dorsey JR, Evans M, et al.

Proc Natl Acad Sci U S A, 2009 Nov 3;106(44):18447-51.
PMID: 19841269 DOI: 10.1073/pnas.0907541106

More than half the world's rainforest has been lost to agriculture since the Industrial Revolution. Among the most widespread tropical crops is oil palm (Elaeis guineensis): global production now exceeds 35 million tonnes per year. In Malaysia, for example, 13% of land area is now oil palm plantation, compared with 1% in 1974. There are enormous pressures to increase palm oil production for food, domestic products, and, especially, biofuels. Greater use of palm oil for biofuel production is predicated on the assumption that palm oil is an "environmentally friendly" fuel feedstock. Here we show, using measurements and models, that oil palm plantations in Malaysia directly emit more oxides of nitrogen and volatile organic compounds than rainforest. These compounds lead to the production of ground-level ozone (O(3)), an air pollutant that damages human health, plants, and materials, reduces crop productivity, and has effects on the Earth's climate. Our measurements show that, at present, O(3) concentrations do not differ significantly over rainforest and adjacent oil palm plantation landscapes. However, our model calculations predict that if concentrations of oxides of nitrogen in Borneo are allowed to reach those currently seen over rural North America and Europe, ground-level O(3) concentrations will reach 100 parts per billion (10(9)) volume (ppbv) and exceed levels known to be harmful to human health. Our study provides an early warning of the urgent need to develop policies that manage nitrogen emissions if the detrimental effects of palm oil production on air quality and climate are to be avoided.

Matched MeSH terms: Aircraft
Fulltext Medical services to the aborigines in West Malaysia

Bolton JM

Br Med J, 1968 Jun 29;2(5608):818-23.
PMID: 5658921
Matched MeSH terms: Aircraft
Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in pp Collisions at sqrt[s]=13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Brandstetter J, et al.

Phys Rev Lett, 2020 May 22;124(20):202001.
PMID: 32501048 DOI: 10.1103/PhysRevLett.124.202001

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at sqrt[s]=13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb^{-1}. The measurement is performed in the lepton+jets channel of tt[over ¯] events, where the lepton is an electron or muon. The products of the hadronic top quark decay t→bW→bqq[over ¯]^{'} are reconstructed as a single jet with transverse momentum larger than 400 GeV. The tt[over ¯] cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6±2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.

Matched MeSH terms: Aircraft
Fulltext Measles outbreak associated with an arriving refugee - Los Angeles County, California, August-September 2011

Centers for Disease Control and Prevention (CDC)

MMWR Morb Mortal Wkly Rep, 2012 Jun 1;61(21):385-9.
PMID: 22647743

Measles is a highly communicable, acute viral illness with potential for severe complications, including death. Although endemic measles was eliminated in the United States in 2000 as a result of widespread vaccination, sporadic measles outbreaks still occur, largely associated with international travel from measles-endemic countries and pockets of unvaccinated persons. On August 26, 2011, the Los Angeles County Department of Public Health (LACDPH) was notified of suspected measles in a refugee from Burma who had arrived in Los Angeles, California, on August 24, after a flight from Kuala Lumpur, Malaysia. Passengers on the flight included 31 other refugees who then traveled to seven other states, widening the measles investigation and response activities. In California alone, 50 staff members from LACDPH and the California Department of Public Health (CDPH) interviewed and reinterviewed 298 contacts. Measles was diagnosed in three contacts of the index patient (patient A). The three contacts with measles were two passengers on the same flight as patient A and a customs worker; no secondary cases were identified. Delayed diagnosis of measles in patient A and delayed notification of health officials precluded use of measles-mumps-rubella (MMR) vaccine as an outbreak intervention. This outbreak emphasizes the importance of maintaining a high level of vaccination coverage and continued high vigilance for measles in the United States, particularly among incoming international travelers; clinicians should immediately isolate persons with suspected measles and promptly report them to health authorities.

Matched MeSH terms: Aircraft*
Fulltext Measles among U.S.-bound refugees from Malaysia--California, Maryland, North Carolina, and Wisconsin, August-September 2011

Centers for Disease Control and Prevention (CDC)

MMWR Morb Mortal Wkly Rep, 2011 Sep 23;60(37):1281-2.
PMID: 21937975

On August 26, 2011, California public health officials notified CDC of a suspected measles case in an unvaccinated male refugee aged 15 years from Burma (the index patient), who had lived in an urban area of Kuala Lumpur, Malaysia, which is experiencing ongoing measles outbreaks. Currently, approximately 92,000 such refugees are living in urban communities in Malaysia. Resettlement programs in the United States and other countries are ongoing. The health and vaccination status of urban refugees are largely unknown.

Matched MeSH terms: Aircraft
Mapping infectious disease landscapes: unmanned aerial vehicles and epidemiology

Fornace KM, Drakeley CJ, William T, Espino F, Cox J

Trends Parasitol, 2014 Nov;30(11):514-9.
PMID: 25443854 DOI: 10.1016/j.pt.2014.09.001

The potential applications of unmanned aerial vehicles (UAVs), or drones, have generated intense interest across many fields. UAVs offer the potential to collect detailed spatial information in real time at relatively low cost and are being used increasingly in conservation and ecological research. Within infectious disease epidemiology and public health research, UAVs can provide spatially and temporally accurate data critical to understanding the linkages between disease transmission and environmental factors. Using UAVs avoids many of the limitations associated with satellite data (e.g., long repeat times, cloud contamination, low spatial resolution). However, the practicalities of using UAVs for field research limit their use to specific applications and settings. UAVs fill a niche but do not replace existing remote-sensing methods.

Matched MeSH terms: Aircraft/standards*
Lost at sea

Normile D

Science, 2014 May 30;344(6187):963-5.
PMID: 24876475 DOI: 10.1126/science.344.6187.963
Matched MeSH terms: Aircraft*
Fulltext Knowledge, confidence and attitude of primary care doctors in managing in-flight medical emergencies: a cross-sectional survey

Ng WL, Abdullah N

Singapore Med J, 2020 Feb;61(2):81-85.
PMID: 32152640 DOI: 10.11622/smedj.2020016

INTRODUCTION: Medical emergencies occur at a rate of one in 604‒753 flights. Doctors travelling on commercial flights may encounter an in-flight medical emergency requiring their assistance. There is a paucity of studies on how confident primary care doctors are in managing in-flight medical emergencies. This study aimed to determine the knowledge, confidence and attitude of primary care doctors in managing in-flight medical emergencies.
METHODS: A cross-sectional study was conducted on all primary care doctors working in government health clinics in Kuala Lumpur, Malaysia, from October 2016 to November 2016. A self-reported questionnaire was used, which included questions on demographic information, knowledge of in-flight medicine, and the attitude and confidence of primary care doctors in managing in-flight medical emergencies.
RESULTS: 182 doctors completed the questionnaire (92.9% response rate). The mean knowledge score was 8.9 out of a maximum score of 20. Only 11.5% of doctors felt confident managing in-flight medical emergencies. The majority (69.2%) would assist in an in-flight medical emergency, but the readiness to assist was reduced if someone else was already helping or if they were not familiar with the emergency. Total knowledge score was positively associated with confidence in managing in-flight medical emergencies (p = 0.03).
CONCLUSION: Only one in ten primary care doctors in this study felt confident managing in-flight medical emergencies. A higher total knowledge score of in-flight medical emergencies was positively associated with greater confidence in managing them. Educational programmes to address this gap in knowledge may be useful to improve doctors' confidence in managing in-flight medical emergencies.

Matched MeSH terms: Aircraft*
Fulltext Interfacial Compatibility Evaluation on the Fiber Treatment in the Typha Fiber Reinforced Epoxy Composites and Their Effect on the Chemical and Mechanical Properties

Rizal S, Ikramullah, Gopakumar DA, Thalib S, Huzni S, Abdul Khalil HPS

Polymers (Basel), 2018 Nov 28;10(12).
PMID: 30961241 DOI: 10.3390/polym10121316

Natural fiber composites have been widely used for various applications such as automotive components, aircraft components and sports equipment. Among the natural fibers Typha spp have gained considerable attention to replace synthetic fibers due to their unique nature. The untreated and alkali-treated fibers treated in different durations were dried under the sun for 4 h prior to the fabrication of Typha fiber reinforced epoxy composites. The chemical structure and crystallinity index of composites were examined via FT-IR and XRD respectively. The tensile, flexural and impact tests were conducted to investigate the effect of the alkali treated Typha fibers on the epoxy composite. From the microscopy analysis, it was observed that the fracture mechanism of the composite was due to the fiber and matrix debonding, fiber pull out from the matrix, and fiber damage. The tensile, flexural and impact strength of the Typha fiber reinforced epoxy composite were increased after 5% alkaline immersion compared to untreated Typha fiber composite. From these results, it can be concluded that the alkali treatment on Typha fiber could improve the interfacial compatibility between epoxy resin and Typha fiber, which resulted in the better mechanical properties and made the composite more hydrophobic. So far there is no comprehensive report about Typha fiber reinforcing epoxy composite, investigating the effect of the alkali treatment duration on the interfacial compatibility, and their effect on chemical and mechanical of Typha fiber reinforced composite, which plays a vital role to provide the overall mechanical performance to the composite.

Matched MeSH terms: Aircraft
Increased levels of depressive symptoms among pregnant women in The Netherlands after the crash of flight MH17

Truijens SE, Boerekamp CA, Spek V, van Son MJ, Oei SG, Pop VJ

Am J Epidemiol, 2015 Sep 1;182(5):426-30.
PMID: 26173773 DOI: 10.1093/aje/kwv161

On July 17, 2014, Malaysia Airlines flight MH17 was shot down, a tragedy that shocked the Dutch population. As part of a large longitudinal survey on mental health in pregnant women that had a study inclusion period of 19 months, we were able to evaluate the possible association of that incident with mood changes using pre- and postdisaster data. We compared mean Edinburgh Depression Scale (EDS) scores from a group of women (n = 126 cases) at 32 weeks' gestation during the first month after the crash with mean scores from a control group (n = 102) with similar characteristics who completed the EDS at 32 weeks' gestation during the same summer period in 2013. The mean EDS scores of the 126 case women in the first month after the crash were significantly higher than the scores of 102 control women. There were no differences in mean EDS scores between the 2 groups at the first and second trimesters. The present study is among the first in which perinatal mental health before and after the occurrence of a disaster has been investigated, and the results suggest that national disasters might lead to emotional responses.

Matched MeSH terms: Aircraft*
Fulltext General characteristics of relative dispersion in the ocean

Corrado R, Lacorata G, Palatella L, Santoleri R, Zambianchi E

Sci Rep, 2017 04 11;7:46291.
PMID: 28397797 DOI: 10.1038/srep46291

The multi-scale and nonlinear nature of the ocean dynamics dramatically affects the spreading of matter, like pollutants, marine litter, etc., of physical and chemical seawater properties, and the biological connectivity inside and among different basins. Based on the Finite-Scale Lyapunov Exponent analysis of the largest available near-surface Lagrangian data set from the Global Drifter Program, our results show that, despite the large variety of flow features, relative dispersion can ultimately be described by a few parameters common to all ocean sub-basins, at least in terms of order of magnitude. This provides valuable information to undertake Lagrangian dispersion studies by means of models and/or of observational data. Moreover, our results show that the relative dispersion rates measured at submesoscale are significantly higher than for large-scale dynamics. Auxiliary analysis of high resolution GPS-tracked drifter hourly data as well as of the drogued/undrogued status of the buoys is provided in support of our conclusions. A possible application of our study, concerning reverse drifter motion and error growth analysis, is proposed relatively to the case of the missing Malaysia Airlines MH370 aircraft.

Matched MeSH terms: Aircraft

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