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1.
Cureus ; 15(11): e49324, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38143649

RESUMEN

BACKGROUND: A second victim (SV) is a healthcare worker who is traumatized by an unexpected adverse patient case, therapeutic mistake, or patient-associated injury that has not been anticipated. Often, the second victim experiences direct guilt for the harm caused to the patients. Healthcare organizations are often unaware of the emotional toll that adverse events can have on healthcare providers (HCPs) who can be harmed by the same incidents that harm their patients. Second victims (SVs) were present in 10.4% up to 43.3% of cases following an adverse event. AIM: This study aims to examine the second victim phenomenon among healthcare providers at Al-Ahsa hospitals, its prevalence, symptoms, associated factors, and support strategies. METHODS: Four major public hospitals participated in this cross-sectional study. The study used the German standardized questionnaire "SeViD-I survey." The directors of the four hospitals sent invitations with links to participate to healthcare providers who had worked in their hospitals for over six months after completing their internship program. RESULTS: More than one-quarter of the respondents (90 (28%)) have been victims of a second victim incident before; of those, 63 (70%) have had it once, 12 (13.3%) twice, and 15 (16.7) repeatedly. In our study, the risk factors for a second victim only appeared in the male gender and were statistically significant. Strong reactivation of situations outside of the workplace was reported in 36 (40%) participants. Thirty-five (38.9%) participants reported reactivating the situation on the job site. Twenty-eight (31%) participants reported aggressive psychosomatic reactions (headaches and back pain). In 28 (31.1%) participants, sleep problems or excessive sleep needs were pronounced. The median of feeling symptoms was 7.2. As for supporting strategies, 64 (71.1%) respondents considered emotional support and crisis management to be very helpful. Sixty-six (73.3%) respondents found a safe chance to be very helpful. CONCLUSION: The findings of this study indicate that healthcare providers in Al-Ahsa, Saudi Arabia, suffer from second victim traumatization at high rates. Several symptoms appear in the second victim, and most do not receive enough support.

2.
Sci Rep ; 12(1): 18963, 2022 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-36347886

RESUMEN

This research endeavored to boost the applicability of methanol in CI engines utilizing n-decanol as cosolvents. The work was split into binary phases. Firstly, the stabilities of pure methanol (M100) and hydrous-methanol (MH10), with diesel as a reference fuel, were examined applying various temperatures: 10 °C, 20 °C, and 30 °C. The findings showed that the M100-diesel and MH10-diesel combinations were unstable. Thus, n-decanol was utilized as a cosolvent. Following by the engine combustion and emissions characteristics were evaluated by manipulating three proportions of M100-diesel mixtures with n-decanol. Three mixtures comprised of 5, 10, and 15% M100 with 20% n-decanol, which are denoted as M5, M10, and M15, correspondingly. These combinations were assessed via thermogravimetric assessment, and their physicochemical properties were assessed corresponding to the ASTM. The maximum in-cylinder pressure, heat release rate, and pressure rise rate diminished by 10, 11, and 10%, respectively, for the M100/diesel/n-decanol combinations compared with the diesel oil. The brake thermal efficiency lowered by 10%, whereas the brake specific fuel consumption enlarged by 10% for the combinations compared with the diesel. NOx and smoke opacity levels diminished by about 30 and 50%, respectively, whereas the CO and UHC enlarged by about 50 and 60% for the blends compared with the diesel oil.


Asunto(s)
Metanol , Emisiones de Vehículos , Metanol/química , Gasolina , Alcoholes Grasos , Biocombustibles
3.
ACS Omega ; 7(10): 8403-8419, 2022 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-35309432

RESUMEN

The design of a highly active Fe-supported catalyst with the optimum particle and pore size, dispersion, loading, and stability is essential for obtaining the desired product selectivity. This study employed a solvothermal method to prepare two Fe-MIL-88B metal-organic framework (MOF)-derived catalysts using triethylamine (TEA) or NaOH as deprotonation catalysts. The catalysts were analyzed using X-ray diffraction, N2-physisorption, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, H2 temperature-programed reduction, and thermogravimetric analysis and were evaluated for the Fischer-Tropsch synthesis performance. It was evident that the catalyst preparation in the presence of TEA produces a higher MOF yield and smaller crystal size than those produced using NaOH. The pyrolysis of MOFs yielded catalysts with different Fe particle sizes of 6 and 35 nm for the preparation in the presence of TEA and NaOH, respectively. Also, both types of catalysts exhibited a high Fe loading (50%) and good stability after 100 h reaction time. The smaller particle size TEA catalyst showed higher activity and higher olefin yield, with 94% CO conversion and a higher olefin yield of 24% at a lower reaction temperature of 280 °C and 20 bar at H2/CO = 1. Moreover, the smaller particle size TEA catalyst exhibited higher Fe time yield and CH4 selectivity but with lower chain growth probability (α) and C5+ selectivity.

4.
ACS Omega ; 6(46): 31099-31111, 2021 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-34841152

RESUMEN

Fischer-Tropsch has become an indispensable choice in the gas-to-liquid conversion reactions to produce a wide range of petrochemicals using recently emerging biomass or other types of feedstock such as coal or natural gas. Herein we report the incorporation of novel Cu nanoparticles with two Fischer-Tropsch synthesis (FTS) catalytic systems, Fe/reduced graphene oxide (rGO) and Fe-Mn/rGO, to evaluate their FTS performance and olefin productivity in two types of reactors: slurry-bed reactor (SBR) and fixed-bed reactor (FBR). Four catalysts were compared and investigated, namely Fe, FeCu7, FeMn10Cu7, and FeMn16, which were highly dispersed over reduced graphene oxide nanosheets. The catalysts were first characterized by transmission electron microscopy (TEM), nitrogen physisorption, X-ray fluorescence (XRF), X-ray diffraction (XRD), and H-TPR techniques. In the SBR, Cu enhanced olefinity only when used alone in FeCu7 without Mn promotion. When used with Mn, the olefin yield was not changed, but light olefins decreased slightly at the expense of heavier olefins. In the FBR system, Cu as a reduction promoter improved the catalyst activity. It increased the olefin yield mainly due to increased activity, even if the CO2 decreased by the action of Cu promoters. The olefinity of the product was improved by Cu promotion but it did not exceed the landmark made by FeMn16 at 320 °C. The paraffinity was also enhanced by Cu promotion especially in the presence of Mn, indicating a strong synergistic effect. Cu was found to be better than Mn in enhancing the paraffin yield, while Mn is a better olefin yield enhancer. Finally, Cu promotion was found to enhance the selectivity towards light olefins C2-4. This study gives a deep insight into the effect of different highly dispersed FTS catalyst systems on the olefin hydrocarbon productivity and selectivity in two major types of FTS reactors.

5.
RSC Adv ; 11(30): 18213-18224, 2021 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-35480937

RESUMEN

This study attempts to enhance the mixture instability of methanol/hydrous methanol mixed with diesel fuel, waste cooking oil (WCO) biodiesel, and Jet A-1 fuel using n-octanol and n-decanol as cosolvent at numerous temperatures of 10 °C, 20 °C, and 30 °C. The experiment is divided into two stages: first, blending pure methanol with diesel oil, Jet A-1, and WCO biodiesel individually utilizing n-octanol and n-decanol as cosolvent at various temperatures. Second, combining hydrous methanol (90% methanol + 10 wt% water) with diesel oil, Jet A-1, and WCO biodiesel independently and applying n-octanol and n-decanol as cosolvent at different temperatures. Pure methanol or hydrous methanol is mixed with the base fuels at different mixing proportions varying from 0 to 100 vol% with 10 vol% increments. The co-solvent, mainly n-octanol and n-decanol (titrant), is progressively and separately inserted into the tube with continuous shaking by utilizing a high-precision pipette until the ternary mixtures' phase borders seem. The findings demonstrate phase separation in pure methanol-diesel and pure methanol-Jet A-1 combinations even when the blend temperature increased to 60 °C. The pure methanol/biodiesel combination proves complete solubility without adding an external agent. The results also illustrate that the ambient temperature considerably affects the stability of mixture and amount of cosolvent in the blend. n-Octanol and n-decanol showed promising performance in enhancing the phase stability issue of methanol and hydrous methanol with the base fuels. It can be deduced that the minimum amount of cosolvent is recorded for biodiesel-hydrous methanol, Jet A-1-hydrous methanol, and diesel-hydrous methanol, respectively.

6.
RSC Adv ; 8(27): 14854-14863, 2018 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-35541361

RESUMEN

Fe nanoparticles (NPs) supported on reduced graphene oxide (rGO) nano-sheets were promoted with Mn and used for the production of light olefins in Fischer-Tropsch reactions carried out in a slurry bed reactor (SBR). The prepared catalysts were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), transmission electron microscope (TEM), Raman spectroscopy, N2 physisorption, temperature programmed reduction (TPR) and X-ray photoelectron spectroscopic (XPS) methods. Mn was shown to preferentially migrate to the Fe NP surface, forming a Mn-rich shell encapsulating a core rich in Fe. The Mn shell regulated the diffusion of molecules to and from the catalyst core, and preserved the metallic Fe phase by lowering magnetite formation and carburization, so decreasing water gas shift reaction (WGSR) activity and CO conversion, respectively. Furthermore, the Mn shell reduced H2 adsorption and increased CO dissociative adsorption which enhanced olefin selectivity by limiting hydrogenation reactions. Modification of the Mn shell thickness regulated the catalytic activity and olefin selectivity. Simultaneously the weak metal-support interaction further increased the migration ability owing to the utilization of a graphene-based support. Space velocities, pressures and operating temperatures were also tested in the reactor to further enhance light olefin production. A balanced Mn shell thickness produced with a Mn concentration of 16 mol Mn/100 mol Fe was found to give a good olefin yield of 19% with an olefin/paraffin (O/P) ratio of 0.77. Higher Mn concentrations shielded the active sites and reduced the conversion dramatically, causing a fall in olefin production. The optimum operating conditions were found to be 300 °C, 2 MPa and 4.2 L g-1 h-1 of 1 : 1 H2 : CO syngas flow; these gave the olefin yield of 19%.

7.
RSC Adv ; 8(74): 42415-42423, 2018 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-35558394

RESUMEN

Mn was used as a promoter for Fe nanoparticles (NPs) loaded on reduced graphene oxide (rGO). The prepared catalysts were the unpromoted Fe/rGO catalysts along with two Mn promoted catalysts FeMn16 and FeMn29. These catalysts were used as Fischer-Tropsch catalysts in a Fixed Bed Reactor (FBR). The operating conditions of the reactor, namely temperature, pressure and space velocity, were varied to evaluate the catalyst performance and the olefin productivity. The olefins were produced in maximum yields of 34.5% and 31.3% with FeMn29 at 320 and 340 °C respectively. The ratio of light to heavy olefins was three times higher at 340 °C. The catalysts showed good stability up to 50 h of interrupted operation while varying the conditions at each interruption. The performance of the catalysts in the FBR was compared with a previous investigation carried out in an SBR under identical conditions with the same catalysts. The FBR was found to be more Mn tolerant than the SBR, giving very high conversion activity with high Mn concentrations (FeMn29). The FBR produced olefins in much higher yields than the SBR. The SBR was more selective to light olefins at low temperatures and high Mn loading levels, while the FBR produced light olefins at higher selectivities at high temperatures and high Mn concentrations.

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