Does safety climate predict safety performance in Italy and the USA? Cross-cultural validation of a theoretical model of safety climate

Previous studies have acknowledged the relevance of assessing the measurement equivalence of safety related measures across different groups, and demonstrating whether the existence of disparities in safety perceptions might impair direct group comparisons. The Griffin and Neal (2000) model of safety climate, and the accompanying measure (Neal et al. [NGH], 2000), are both widely cited and utilized. Yet neither the model in its entirety nor the measure have been previously validated across different national contexts. The current study is the first to examine the NGH measurement equivalence by testing whether their model of safety climate predicting safety performance is tenable in both English speaking and non-English speaking countries. The study involved 616 employees from 21 organizations in the US, and 738 employees from 20 organizations in Italy. A multi-group confirmatory factor analytic approach was used to assess the equivalence of the measures across the two countries. Similarly, the structural model of relations among the NGH variables was examined in order to demonstrate its cross-country invariance. Results substantially support strict invariance across groups for the NGH safety scales. Moreover, the invariance across countries is also demonstrated for the effects of safety climate on safety knowledge and motivation, which in turn positively relate to both compliance and participation. Our findings have relevant theoretical implications by establishing measurement and relational equivalence of the NGH model. Practical implications are discussed for managers and practitioners dealing with multi-national organizational contexts. Future research should continue to investigate potential differences in safety related perceptions across additional non-English speaking countries.     

Determination of microheterogeneous substitution in shrimp tropomyosin and its effect on IgE-binding capacity

Tropomyosin (TM), the major shrimp allergen that belongs to a highly conserved protein family, has frequently been investigated owing to its high rate of human consumption. In this study, the sequence microheterogeneity of TMs, irrespective of the organism and differences in the N- and C-termini, from different shrimp species was analyzed. The TM sequences were analyzed using bioinformatics tools and confirmed by dot-blot using human serum. The results showed that all 13 shrimp species share high mutual TM sequence identity values, ranging from 85.5 to 99.7 %, and 60 cases of sequence microheterogeneity were identified in shrimp TM, with a sequence identity ranging from 90.1 to 99.7 %. A total of 719 unique amino acid residue substitutions (that affect 43 residues, 15 % of 284 residues) involving sequence microheterogeneity were characterized, in which 214 substitutions involving 15 residues were located in the epitope regions. About 45 % of these substitutions occurred in the TM sequences that are reported allergens, whereas 43 % of the substitutions occurred overall for the allergenic and nonallergenic TMs. Dot-blot immunoassay revealed that single microheterogeneous mutation of allergic peptides resulted in significant changes in the IgE-binding capacity of the peptides. Overall, microheterogeneous mutations of TM occurred in different shrimp species. These mutations can potentially induce changes in the IgE-binding capacity and might be responsible for variations in the hypersensitivity to different shrimp species.     

Evaluating the performance of an integrated CALPUFF-MM5 modeling system for predicting SO<Subscript>2</Subscript> emission from a refinery

Oil refineries are one of the proven sources of environmental pollution as they emit more than 100 chemicals into the atmosphere including sulfur dioxide (SO₂). The dispersion patterns of SO₂ from emissions of Sohar refinery was simulated by employing California Puff (CALPUFF) model integrated with state of the art meteorological Mesoscale Model (MM5). The results of this simulation were used to quantify the ground level concentrations of SO₂ in and around the refinery. The evaluation of the CALPUFF and MM5 modeling system was carried out by comparing the estimated results with that of observed data of the same area. The predicted concentrations of SO₂ agreed well with the observed data, with minor differences in magnitudes. In addition, the ambient air quality of the area was checked by comparing the model results with the regulatory limits for SO₂ set by the Ministry of Environment and Climate Affairs (MECA) in Oman. From the analysis of results, it was found that the concentration of SO₂ in the nearby communities of Sohar refinery is well within the regulatory limits specified by MECA. Based on these results, it was concluded that no health risk, due to SO₂ emissions, is present in areas adjacent to the refinery.     

Structural elucidation of humic acids extracted from Pakistani lignite using spectroscopic and thermal degradative techniques

The present paper describes the characterization of Pakistan lignite coal, derived humic acids (HAL) and nitrohumic acids (NHA) along with the standard leonardite humic acids (LHA). The study utilized chromatographic and spectroscopic techniques to characterize the structure of coal and derived materials. Pyrolysis coupled to gc/ms was conducted with and without methylating agent (tetramethyl ammonium hydroxide). The pyrolysis study resulted in releasing mainly fatty acid methyl esters, different series of hydrocarbons and α, ω-dicarboxylic acid methyl esters. Triterpenoids, syringic and ρ-coumaric compounds and aromatic compounds derived from lignin moieties were also detected. Fourier transform infrared (FT-IR) and NMR data helped to evaluate the influence of coal rank on regeneration and nitration processes with respect to chemical structural composition of coal and derived materials. FT-IR spectra of four materials were similar except that NHA showed an absorption band at 1532 cm⁻¹, thus confirming the presence of -NO₂ groups. ¹³C NMR indicated higher aromaticity and less hydroxylalkyl material in HAL than NHA. The elemental composition and acid functional group content of four materials were also reported.The combination of results from different analytical techniques gives an improved understanding of the Pakistan coal nature and helpful for its future utilization.     

Material Characterization of Ge1−x Sn x Alloys Grown by a Commercial CVD System for Optoelectronic Device Applications

High-quality compressive-strained Ge_1?x Sn _x /Ge films have been deposited on Si(001) substrate using a mainstream commercial chemical vapor deposition reactor. The growth temperature was kept below 450°C to be compatible with Si complementary metal–oxide–semiconductor processes. Germanium tin (Ge_1?x Sn _x ) layers were grown with different Sn composition ranging from 0.9% to 7%. Material characterizations, such as secondary-ion mass spectrometry, Rutherford backscattering spectrometry, and x-ray diffraction analysis, show stable Sn incorporation in the Ge lattice. Comparison of the Sn mole fractions obtained using these methods shows that the bowing factor of 0.166 nm (in Vegard’s law) is in close agreement with other experimental data. High-resolution transmission electron microscopy and atomic force microscopy results show that the films have started to relax through the formation of misfit and threading dislocations. Raman spectroscopy, ellipsometry, and photoluminescence (PL) techniques are used to study the structural and optical properties of the films. Room-temperature PL of the films shows that 7% Sn incorporation in the Ge lattice results in a decrease in the direct bandgap of Ge from 0.8 eV to 0.56 eV.     

A new metal-to-metal antifuse with amorphous carbon

We report the development of a new metal-to-metal antifuse with amorphous carbon as the dielectric. Amorphous carbon antifuses have several characteristics making them superior to amorphous silicon antifuses, including lower values of OFF-state leakage current, ON-state resistance, dielectric constant, and breakdown voltage. Most importantly, amorphous carbon antifuses do not show ON-OFF switching, which is observed in amorphous silicon antifuses. A new model is proposed to explain the breakdown mechanism and ON-state reliability of amorphous carbon antifuses     

Geochemistry of cretaceous rocks,Pakistan: I. Biomarker approach to assess thermal maturity of OM

The sediment samples from cretaceous sequences, Lower Indus basin, were analyzed using diagnostic biomarkers to predict the thermal maturity of organic matter. The sediments were tested for aliphatic biomarkers ratios, i.e. homohopanes and steranes isomerization ratios and carbon preference indices. These biomarker maturity parameters reveal that the Lower Goru (including its members Upper shale, Lower shale, and Talhar shale) and Sembar Formations in the Lower Indus Basin of Cretaceous age have reached the maturity level equivalent to the main zone of hydrocarbons generation, whereas Parh and Upper Goru Formations are immature and far from oil window. Geochemical analyses carried out stresses that hydrocarbons derived from the Sembar and Lower Goru Formations (particularly deeper Members) are within the zone of peak oil generation.     

Modeling and electrical analysis of seamless high off-chipconnectivity (SHOCC) interconnects

Scaling down on-chip interconnect cross-sectional dimensions results not only in higher circuit wiring density, but also in the long lossy line problem, wherein the long lines become highly resistive and have unacceptable delays. One possible solution to the problem of long lossy lines is to transfer these lines off-chip using seamless high off-chip connectivity (SHOCC) technology. In this work, me modeled and studied the electrical performance of SHOCC signal lines. The performance of SHOCC interconnects was compared with that of typical on-chip interconnerts. Modeling and simulation results, along with recommendations with regards to driver sizes and the type of interconnect that should be used, are presented     

Hydrocarbon potential of cretaceous sediments from lower Indus Basin,Pakistan

In previous studies, Patala-Nammal Composite Total Petroleum System (TPS) was recognized as a potential source of hydrocarbon in the Upper Indus Basin, and Sembar-Goru Composite TPS in the Lower Indus Basin. However, petroleum source-rock potential of Cretaceous strata in the Indus Basin is poorly known. In the current study, Rock Eval and total organic carbon (TOC) analyses were conducted to investigate the thermal maturity and source-rock potential of Cretaceous unit in the Lower Indus Basin. The Parh Formation of the Lower Indus Basin is lean in organic contents (TOC < 0.73%) and consistent with immature type-III/IV kerogen. The Upper Goru Formation is fair in organic contents and presents similar characteristics to the Parh Formation with respect to the hydrocarbon generation zone. The Lower Goru Formation presents fair to very good organic contents. The members of Lower Goru Formation have enough organic matter (OM) and are mature, with the exception of Badin shales. The OM, throughout the formation, is predominantly gas prone. The Sembar Formation is fair in organic contents and mature with respect to hydrocarbons generation. These results support that the Lower Goru rocks are comparatively more prospective with respect to hydrocarbons.