1,083 research outputs found

    Perceptions of Safety Climate in Construction Projects between Workers and Managers/Supervisors in the Developing Country of Iran

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    What are the different perceptions on safety climate (SC) by workers and managers/supervisors engaged in the construction industry of developing countries? Reconciling these two differing views is pivotal for mitigating and avoiding both the injured and fatal accidents in the construction industry, especially in those developing countries where safety conditions are poor and unpredictable, and safety measures are inadequate in most cases. To answer this research question, the collective perceptions of 118 construction workers and 123 managers/supervisors on the SC in construction projects in Iran were gleaned and investigated. In particular, these perceptions were initially collected by two different empirical surveys validated by a sample of university professors and construction managers and then analyzed through the Kaiser-Meyer-Olkin (KMO) test and Bartlett’s test of sphericity under factor analysis, together with a one-sample t-test. Results indicated that “workers’ attitudes and perceptions”, “safety knowledge and training”, “working relationships and roles of colleagues”, and “workers’ risk perceptions” are important categories of SC factors perceived by construction workers, whereas “safety rules and management practices” is the essential category of SC factors discerned by managers/supervisors. The difference in perceptions between workers and managers/supervisors is considered to be beneficial for an overall understanding of SC in general and for developing countries in particular. Moreover, a series of effective suggestions for improving SC in the construction industry of developing countries are provided with reference to each category. The views of SC factors are reinforced as a social process combining the synergies of workers and managers/supervisors, as well as proper safety training to be pushed forward as an essential activity that should be incorporated in human resources development of construction organizations so as to improve the existing level of SC, leading to fewer accidents at the industry level

    Tailoring spontaneous infrared emission of HgTe quantum dots with laser-printed plasmonic arrays.

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    Chemically synthesized near-infrared to mid-infrared (IR) colloidal quantum dots (QDs) offer a promising platform for the realization of devices including emitters, detectors, security, and sensor systems. However, at longer wavelengths, the quantum yield of such QDs decreases as the radiative emission rate drops following Fermi's golden rule, while non-radiative recombination channels compete with light emission. Control over the radiative and non-radiative channels of the IR-emitting QDs is crucially important to improve the performance of IR-range devices. Here, we demonstrate strong enhancement of the spontaneous emission rate of near- to mid-IR HgTe QDs coupled to periodically arranged plasmonic nanoantennas, in the form of nanobumps, produced on the surface of glass-supported Au films via ablation-free direct femtosecond laser printing. The enhancement is achieved by simultaneous radiative coupling of the emission that spectrally matches the first-order lattice resonance of the arrays, as well as more efficient photoluminescence excitation provided by coupling of the pump radiation to the local surface plasmon resonances of the isolated nanoantennas. Moreover, coupling of the HgTe QDs to the lattice plasmons reduces the influence of non-radiative decay losses mediated by the formation of polarons formed between QD surface-trapped carriers and the IR absorption bands of dodecanethiol used as a ligand on the QDs, allowing us to improve the shape of the emission spectrum through a reduction in the spectral dip related to this ligand coupling. Considering the ease of the chemical synthesis and processing of the HgTe QDs combined with the scalability of the direct laser fabrication of nanoantennas with tailored plasmonic responses, our results provide an important step towards the design of IR-range devices for various applications

    Ab initio Study of Ground-State CS Photodissociation Via Highly Excited Electronic States

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    Photodissociation by ultraviolet radiation is the key destruction pathway for CS in photon-dominated regions, such as diffuse clouds. However, the large uncertainties of photodissociation cross sections and rates of CS, resulting from a lack of both laboratory experiments and theoretical calculations, limit the accuracy of calculated abundances of S-bearing molecules by modern astrochemical models. Here we show a detailed \textit{ab initio} study of CS photodissociation. Accurate potential energy curves of CS electronic states were obtained by choosing an active space CAS(8,10) in MRCI+Q/aug-cc-pV(5+d)Z calculation with additional diffuse functions, with a focus on the BB and C\,^1\Sigma^+ states. Cross sections for both direct photodissociation and predissociation from the vibronic ground state were calculated by applying the coupled-channel method. We found that the CXC-X (00)(0-0) transition has extremely strong absorption due to a large transition dipole moment in the Franck-Condon region and the upper state is resonant with several triplet states via spin-orbit couplings, resulting in predissociation to the main atomic products C (3P)(^3P) and S (1D)(^1D). Our new calculations show the photodissociation rate under the standard interstellar radiation field is 2.9\ee{-9}\,s1^{-1}, with a 57\% contribution from CXC-X (00)(0-0) transition. This value is larger than that adopted by the Leiden photodissociation and photoionization database by a factor of 3.0. Our accurate \textit{ab initio} calculations will allow more secure determination of S-bearing molecules in astrochemical models.Comment: 23 pages, 14 figure

    Genotyping of Sarawak rice cultivars using microsatellite markers

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    Genetic diversity of 53 Sarawak rice cultivars, originating from Southern Sarawak, was assessed using 54 microsatellite markers. Initial polymorphism detection was conducted using 54 primer pairs distributed on 12 rice chromosomes. Polymorphic markers were chosen from the initial screening results in order to obtain microsatellite marker panels that can differentiate the rice cultivars undertaken in the study. The chosen microsatellite marker panel consisted of RM1, RM240, RM489, RM252, RM413, RM204, RM11, RM404, RM316, RM271, RM206, and RM19, with one representative from each chromosome. A total of 43 alleles were detected with an average of 3.58 alleles per locus. The polymorphism information content (PIC) values obtained from the microsatellite marker panels ranged from 0.306 to 0.730, with an average of 0.622. The Unweighted Pair Group Method with Arithmetic Mean (UPGMA) dendrogram (r = 0.789) revealed 2 major groups with 6 sub-clusters and the wide range of similarity values (0.24-1.0) obtained showed a high degree of diversity among the cultivars. The results suggest microsatellite markers as a useful tool for the estimation of genetic diversity and cultivar differentiation and present invaluable genetic information for future breeding and association mapping efforts

    A new design method for broadband microphone arrays for speech input in automobiles

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    Global Guidelines in Dermatology Mapping Project (GUIDEMAP):a scoping review of dermatology clinical practice guidelines

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    Background Clinical practice guidelines (CPGs) play a critical role in standardizing and improving treatment outcomes based on the available evidence. It is unclear how many CPGs are available globally to assist clinicians in the management of patients with skin disease. Objectives To search for and identify CPGs for dermatological conditions with the highest burden globally. Methods We adapted a list of 12 dermatological conditions with the highest burden from the Global Burden of Disease (GBD) study 2019. A systematic literature search was done to identify CPGs published between October 2014 to October 2019. The scoping review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) framework. Results A total of 226 CPGs were included. Melanoma had the greatest representation in the CPGs, followed by dermatitis and psoriasis. Skin cancers had a relatively high CPG representation but with lower GBD disease burden ranking. There was an uneven distribution by geographical region, with resource-poor settings being under-represented. The skin disease categories of the CPGs correlated weakly with the GBD disability-adjusted life-years metrics. Eighty-nine CPGs did not have funding disclosures and 34 CPGs were behind a paywall. Conclusions The global production of dermatology CPGs showed wide variation in geographical representation, article accessibility and reporting of funding. The number of skin disease CPGs were not commensurate with its disease burden. Future work will critically appraise the methodology and quality of dermatology CPGs and lead to the production of an accessible online resource summarizing these findings.Dermatology-oncolog

    Differential permeability reduction in single-bottle adhesives with an oxalate desensitizer

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    Lowest-lying Tetra-Quark Hadrons in Anisotropic Lattice QCD

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    We present a detailed study of lowest-lying q2qˉ2q^{2}\bar{q}^{2} hadrons in quenched improved anisotropic lattice QCD. Using the ππ\pi\pi and diquark-antidiquark local and smeared operators, we attempt to isolate the signal for I(JP)=0(0+),2(0+)I(J^{P})=0(0^{+}), 2(0^{+}) and 1(1+)1(1^{+}) states in two flavour QCD. In the chiral limit of light-quark mass region, the lowest scalar 4q4q state is found to have a mass, m4qI=0=927(12)m^{I=0}_{4q}=927(12) MeV, which is slightly lower than the experimentally observed f0(980)f_{0}(980). The results from our variational analysis do not indicate a signature of a tetraquark resonance in I=1 and I=2 channels. After the chiral extrapolation the lowest 1(1+)1(1^{+}) state is found to have a mass, m4qI=1=1358(28)m^{I=1}_{4q}=1358(28) MeV. We analysed the static 4q4q potential extracted form a tetraquark Wilson loop and illustrated the behaviour of the 4q4q state as a bound state, unbinding at some critical diquark separation. From our analysis we conclude that scalar 4q4q system appears as a two-pion scattering state and that there is no spatially-localised 4q4q state in the light-quark mass region.Comment: 9 pages, 10 figure

    Surgical aortic valve replacement in the era of transcatheter aortic valve implantation: a review of the UK national database

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    Objectives To date the reported outcomes of surgical aortic valve replacement (SAVR) are mainly in the settings of trials comparing it with evolving transcatheter aortic valve implantation. We set out to examine characteristics and outcomes in people who underwent SAVR reflecting a national cohort and therefore ‘real-world’ practice. Design Retrospective analysis of prospectively collected data of consecutive people who underwent SAVR with or without coronary artery bypass graft (CABG) surgery between April 2013 and March 2018 in the UK. This included elective, urgent and emergency operations. Participants’ demographics, preoperative risk factors, operative data, in-hospital mortality, postoperative complications and effect of the addition of CABG to SAVR were analysed. Setting 27 (90%) tertiary cardiac surgical centres in the UK submitted their data for analysis. Participants 31 277 people with AVR were identified. 19 670 (62.9%) had only SAVR and 11 607 (37.1%) had AVR+CABG. Results In-hospital mortality for isolated SAVR was 1.9% (95% CI 1.6% to 2.1%) and was 2.4% for AVR+CABG. Mortality by age category for SAVR only were: 75 years=2.2%. For SAVR+CABG these were; 2.2%, 1.8% and 3.1%. For different categories of EuroSCORE, mortality for SAVR in low risk people was 1.3%, in intermediate risk 1% and for high risk 3.9%. 74.3% of the operations were elective, 24% urgent and 1.7% emergency/salvage. The incidences of resternotomy for bleeding and stroke were 3.9% and 1.1%, respectively. Multivariable analyses provided no evidence that concomitant CABG influenced outcome. However, urgency of the operation, poor ventricular function, higher EuroSCORE and longer cross clamp and cardiopulmonary bypass times adversely affected outcomes. Conclusions Surgical SAVR±CABG has low mortality risk and a low level of complications in the UK in people of all ages and risk factors. These results should inform consideration of treatment options in people with aortic valve disease
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