RESUMO
In this work, we analyzed trifluoromethyl fluorosulfonate (CF3OSO2F) and trifluoromethoxy sulfur pentafluoride (CF3OSF5) regarding their potential use as dielectrics by investigating some of their intrinsic and extrinsic properties. Both compounds show a higher breakdown voltage than SF6 with averaged relative breakdown voltages of 1.3±0.2 for CF3OSO2F and 1.4±0.2 for CF3OSF5 compared to SF6 with 1.0. Like the dielectric (CF3)2CFCN, both compounds decompose during the breakdown process. The decomposition products were analyzed by IR spectroscopy and GCIR methods. Furthermore, the molecular structures of both gaseous compounds CF3OSO2F and CF3OSF5 have been determined by inâ situ crystallization, and their physical properties were determined as well.
RESUMO
With the annual global electricity production exceeding 30,000 TWh, the safe transmission of electric power has been heavily relying on SF6, the most potent industrial greenhouse gas. While promising SF6 alternatives have been proposed, their compatibilities with materials used in gas-insulated equipment (GIE) must be thoroughly studied. This is particularly true as the emerging SF6 alternatives generally leverage their relatively higher reactivity to achieve lower global warming potentials (GWPs). Here, a high-throughput compatibility screening of common GIE materials was conducted with a representative SF6 alternative, namely, C4F7N (2,3,3,3-tetrafluoro-2-(trifluoromethyl)propanenitrile)/CO2 gas mixtures. In this screening, the insulation performance of C4F7N/CO2 gas mixtures, as an indicator of the C4F7N/materials compatibility level, was periodically monitored during the thermal aging with tens of materials from SF6-insulated GIE, including desiccants/adsorbents, rubber, plastics, composites, ceramics, metals, etc. The identification of incompatible materials and the follow-up mechanism studies suggested that the acidity of materials represents the primary cause for C4F7N/materials incompatibility when C4F7N/CO2 gas mixtures are used as a drop-in replacement solution for existing SF6-insulated apparatuses. Mitigation strategies tackling the acidity of materials were then proposed and validated. Additionally, the amphoteric characteristics of C4F7N were briefly discussed. This work provides insight into the materials incompatibility of SF6 alternatives, along with validated mitigation strategies, for the selection and design of materials used in future eco-friendly GIE.
RESUMO
BACKGROUND: The second version of the Short-Form 6-Dimension (SF-6Dv2) classification system has recently been developed. The objective of this study was to develop a value set for SF-6Dv2 based on the societal preferences of a general population in the capital of Iran. METHODS: A representative sample of the capital of Iran (n = 3061) was recruited using a stratified multistage quota sampling technique. Face-to-face interviews were conducted using binary choice sets from the international valuation protocol of the discrete choice experiment with duration. The conditional logit was used to estimate the final value set, and a latent class model was employed to assess heterogeneity of preferences. RESULTS: Coefficients generated from the models were logically consistent and significant. The best model was the one that included an additional interaction term for cases where one or more dimensions reached their most severe levels. It provides a value set with logical consistent coefficients and the lowest percentage of worse than death health states. Predicted values for the SF-6Dv2 were within the range of - 0.796-1. Pain dimension had the largest impact on utility decrement, whereas vitality had the least impact. The presence of preference heterogeneity was evident, and the Bayesian Information Criterion indicated the optimal fit for a latent class model with two classes. CONCLUSION: This study provided the SF-6Dv2 value set for application in the context of Iran. This value set will facilitate the use of the SF-6Dv2 instrument in health economic evaluations and clinical settings.
Assuntos
Qualidade de Vida , Humanos , Irã (Geográfico) , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Inquéritos e Questionários , Idoso , Nível de Saúde , Comportamento de Escolha , Adulto Jovem , Psicometria , Adolescente , Entrevistas como AssuntoRESUMO
PURPOSE: To develop the mapping functions from the Impact of Weight on Quality of Life-Lite (IWQOL-Lite) scores onto the EQ-5D-5L and SF-6Dv2 utility values among the overweight and obese population in China. METHODS: A representative sample of the overweight and obese population in China stratified by age, sex, body mass index (BMI), and area of residence was collected by online survey and the sample was randomly divided into development (80%) and validation (20%) datasets. The conceptual overlap between the IWQOL-Lite and the EQ-5D-5L or SF-6Dv2 was evaluated by Spearman's correlation coefficients. Five models, including OLS, Tobit, CLAD, GLM, and PTM were explored to derive mapping functions using the development dataset. The model performance was assessed using MAE, RMSE, and the percentage of AE > 0.05 and AE > 0.1 in the validation dataset. RESULTS: A total of 1000 respondents (48% female; mean [SD] age: 51.7 [15.3]; mean [SD] BMI: 27.4 [2.8]) were included in this study. The mean IWQOL-Lite scores and the utility values of EQ-5D-5L and SF-6Dv2 were 78.5, 0.851, and 0.734, respectively. The best-performing models predicting EQ-5D-5L and SF-6Dv2 utilities both used IWQOL-Lite total score as a predictor in the CLAD model (MAE: 0.083 and 0.076 for the EQ-5D-5L and SF-6Dv2; RMSE: 0.125 and 0.103 for the EQ-5D-5L and SF-6Dv2; AE > 0.05: 20.5% and 27.5% for the EQ-5D-5L and SF-6Dv2; AE > 0.10: 9.5% and 15.0% for the EQ-5D-5L and SF-6Dv2). CONCLUSION: CLAD models with the IWQOL-Lite total score can be used to predict both the EQ-5D-5L and SF-6Dv2 utility values among overweight and obese population in China.
Assuntos
Sobrepeso , Qualidade de Vida , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Qualidade de Vida/psicologia , Inquéritos e Questionários , China , ObesidadeRESUMO
BACKGROUND: Because health resources are limited, health programs should be compared to allow the most efficient ones to emerge. To that aim, health utility instruments have been developed to allow the calculation of quality-adjusted life-year (QALY). However, generic instruments, which can be used by any individual regardless of their health profile, typically consider the preferences of the general population when developing their value set. Consequently, they are often criticized for lacking sensitivity in certain domains, such as cancer. In response, the latest version of the Short Form 6-Dimension (SF-6Dv2) has been adapted to suit the preferences of patients with breast or colorectal cancer in the Canadian province of Quebec. By extension, our study's aim was to determine cancer population norms of utility among patients with breast or colorectal cancer in Quebec using the SF-6Dv2. METHOD: To determine the cancer population norms, we exploited the data that were used in the development of a new value set for the SF-6Dv2. This value set was developed considering the preferences of patients with breast or colorectal cancer. Stratification by time of data collection (i.e., T1 and T2), sociodemographic variables (i.e., age, sex, body mass index, and self-reported health problems affecting quality of life), and clinical aspects (i.e., cancer site, histopathological classification, cancer stage at diagnosis, modality, and treatment characteristics) was performed. RESULTS: In 353 observations, patients were more likely to have negative utility scores at T1 than at T2. Males had higher mean utility scores than females considering type of cancer and comorbidities. Considering the SF-6Dv2's dimensions, more females than males reported having health issues, most which concerned physical functioning. Significant differences by sex surfaced for all dimensions except "Role Limitation" and "Mental health." Patients with multifocal cancer had the highest mean and median utility values in all cancer sites considered. CONCLUSION: Cancer population norms can serve as a baseline for interpreting the scores obtained by a given population in comparison to the situation of another group. In this way, our results can assist in comparing utility scores among cancer patients with different sociodemographic groups to other patients/populations groups. To our knowledge, our identified utility norms are the first for patients with breast or colorectal cancer from Quebec.
Assuntos
Neoplasias da Mama , Neoplasias Colorretais , Humanos , Quebeque , Feminino , Neoplasias Colorretais/psicologia , Masculino , Pessoa de Meia-Idade , Idoso , Neoplasias da Mama/psicologia , Inquéritos e Questionários , Adulto , Qualidade de Vida , Preferência do Paciente/psicologia , Anos de Vida Ajustados por Qualidade de Vida , Psicometria , Nível de Saúde , Idoso de 80 Anos ou maisRESUMO
Sulfur hexafluoride (SF6) gas is extensively utilized as an insulating and arc-quenching medium in the circuit breakers and isolating switches of electrical equipment. It effectively isolates the circuits from the atmosphere and promptly extinguishes arcs. Therefore, the issue of SF6 gas leakage poses a significant threat to the related application fields, and the detection of SF6 gas leakage becomes extremely important. Infrared imaging detection offers advantages including non-contact, high precision, and visualization. However, most existing infrared detection systems are equipped with only one filter to detect SF6 gas. The images captured contain background noise and system noise, making these systems vulnerable to interference from such noises. To address these issues, we propose a method for monitoring SF6 gas leakage based on a customized binocular imaging (CBI) system. The CBI system has two filters, greatly reducing the interference of system noise and background noise. The first filter features the absorption resonant peak of SF6 gas. The second filter is used to record background noise and system noise. One aspect to note is that, in order to avoid the interference of other gases, the central wavelength of this second filter should keep away from the absorption resonant peaks of those gases. Accordingly, the central wavelengths of our customized filters were determined as 10,630 nm and 8370 nm, respectively. Then, two cameras of the same type were separately assembled with a customized filter, and the CBI prototype was accomplished. Finally, we utilized the difference method using two infrared images captured by the CBI system, to monitor the SF6 gas leakage. The results demonstrate that our developed system achieves a high accuracy of over 99.8% in detecting SF6 gas. Furthermore, the CBI system supports a plug-and-play customization to detect various gases for different scenarios.
RESUMO
To enhance the precision of evaluating the operational status of SF6 high-voltage circuit breakers (HVCBs) and devise judicious maintenance strategies, this study introduces an operational state assessment method for SF6 HVCBs grounded in the integrated data-driven analysis (IDDA) model. The relative degradation weight (RDW) is introduced as a metric for quantifying the relative significance of distinct indicators concerning the operational condition of SF6 HVCBs. A data-driven model, founded on critical factor stability (CFS), is formulated to convert environmental indicators into quantitative computations. Furthermore, an optimized fuzzy inference (OFI) system is devised to streamline the system architecture and enhance the processing speed of continuous indicators. Ultimately, the efficacy of the proposed model is substantiated through validation, and results from instance analyses underscore that the presented approach not only attains heightened accuracy in assessment compared to extant analytical methodologies but also furnishes a dependable foundation for prioritizing maintenance sequences across diverse components.
RESUMO
The online monitoring of GIS equipment can be realized through detecting SF6 decomposition gasses. Metal oxide heterojunctions are widely used as gas-sensing materials. In this study, the structural and electrical properties of In2O3-ZnO and TiO2-ZnO heterojunctions were analyzed based on density functional theory calculations. After heterojunction structural optimization, the electrical conductivity of these two heterojunctions was enhanced compared to each intrinsic model, and the electrical conductivity is ranked as follows: In2O3-ZnO heterojunction > TiO2-ZnO heterojunction. The gas-sensing response of these two heterojunctions to four SF6 decomposition gasses, H2S, SO2, SOF2, and SO2F2, was investigated. For gas adsorption systems, the adsorption energy, charge transfer, density of states, charge difference density, and frontier molecular orbitals were calculated to analyze the adsorption and gas-sensing performance. For gas adsorption on the In2O3-ZnO heterojunction surface, the induced conductivity changes are in the following order: H2S > SO2F2 > SOF2 > SO2. For gas adsorption on the TiO2-ZnO heterojunction surface, H2S and SOF2 increase conductivity, and SO2 and SO2F2 decrease conductivity.
Assuntos
Teoria da Densidade Funcional , Gases , Titânio , Titânio/química , Gases/química , Adsorção , Condutividade Elétrica , Óxidos/química , Óxido de Zinco/química , Hexafluoreto de Enxofre/química , Dióxido de Enxofre/química , ÍndioRESUMO
Essential oils (EOs), as rumen additives, decreased CH4 emissions in in vitro trials but results from in vivo studies are still limited. We investigated the effects of Origanum vulgare (OEO) and Thymus vulgaris (TEO) EOs on in vivo methane emissions from Nellore beef cattle. Six adult rumen-cannulated Nellore cattle were used in a double 3 × 3 Latin square design. Treatments consisted of three diets containing either 3 mL OEO per kg of concentrate, 3 mL TEO/kg of concentrate, or no EO addition. The experimental period consisted of three 21 d feeding periods and methane production was measured using the sulfur hexafluoride (SF6) technique from Day 16 to Day 21 of each feeding period. Intake, total apparent digestibility (dry matter as well as neutral and acid detergent fiber), and rumen parameters (pH, ammoniacal nitrogen concentration, and short-chain fatty acids) were also evaluated. The EOs did not decrease CH4 emissions and had no effect on rumen parameters.
RESUMO
The purpose of this study was to evaluate the differences in annual pasture and native pasture on dry matter (DM) intake, nutrient digestibility, nitrogen (N) and energy utilization, and methane (CH4) emission of grazing sheep, and to provide the basis for rational livestock grazing in salinized regions. The study used 10 male Hu sheep ââ ×â thin-tailed Han sheep â rams (20â ±â 5 kg) aged 5 mo. Sheep grazing was conducted in annual pasture and native pasture using a 2â ×â 2 Latin square design. After a 15-d adaptation period for grazing, the digestion and metabolism experiment of sheep were conducted, while CH4 emissions were measured using sulfur hexafluoride tracer gas. DM intake did not differ between annual pasture and native pasture (Pâ =â 0.386). Meanwhile, the digestibility of DM (Pâ <â 0.001), neutral detergent fiber (Pâ <â 0.001), acid detergent fiber (Pâ <â 0.01), crude protein (Pâ <â 0.001), and ether extract (Pâ <â 0.001) of sheep grazing on native pasture was significantly higher than that of annual pasture. Sheep grazing on native pasture had increased N intake (Pâ <â 0.001) and N retained (Pâ <â 0.001) compared with those grazing on annual pasture. Digestion energy (Pâ <â 0.05) and metabolic energy (Pâ <â 0.01) of sheep grazing on annual pasture were significantly improved compared with those on native pasture, while fecal energy (Pâ <â 0.001), urine energy (Pâ <â 0.001) and CH4 energy (CH4-E) output (Pâ <â 0.001) and CH4 emission (Pâ <â 0.001) of sheep grazing on annual pasture were significantly decreased. The CH4-E/gross energy (GE) values of sheep grazing on annual pasture and native pasture were 0.09 and 0.10, respectively. In conclusion, grazing sheep have higher N utilization on native pasture, whereas grazing sheep have higher energy utilization and low CH4 emissions in annual pasture. In conclusion, annual pasture has a lower CH4-E/GE compared to native pasture, which helps in reducing environmental pollution.
The reduction of methane (CH4) emissions and nitrogen (N) excretion from livestock production systems can help mitigate environmental impact and improve feeding efficiency. The energy requirements of livestock are crucial for enhancing their performance and minimizing environmental impact. It is imperative to accurately ascertain the N and energy efficiency, and CH4 emissions associated with sheep grazing across diverse grassland ecosystems to optimize forage resource utilization without compromising livestock production performance, thereby facilitating sustainable grassland management and grazing practices. Sheep grazing on native pasture had higher nutrient digestibility and N utilization, while sheep grazing on annual pasture showed higher energy utilization and less CH4 emissions. CH4-energy/gross energy for grazing sheep on annual pasture and native pasture was 0.09 and 0.10, respectively. This study assessed the differences in N and energy utilization and CH4 emissions, among sheep grazing on different grasses, providing data support for the development of more rational livestock grazing methods.
Assuntos
Ração Animal , Dieta , Ovinos , Masculino , Animais , Ração Animal/análise , Dieta/veterinária , Metano/metabolismo , Nitrogênio/metabolismo , Detergentes , Carneiro Doméstico , DigestãoRESUMO
BACKGROUND: Post-pneumonectomy syndrome (PPS) is a rare but serious condition that can occur after pneumonectomy. It is characterized by a mediastinal shift towards the vacated hemithorax, which can potentially lead to respiratory failure. The management of PPS poses a clinical challenge, especially in the context of the limited availability of certain therapeutic devices due to regulatory restrictions in Japan. CASE PRESENTATION: A 36-year-old female with stage IB non-small cell lung cancer underwent left pneumonectomy. Approximately 2 years later, she developed dyspnea. After consulting with our hospital, subsequent imaging revealed an extreme mediastinal shift causing bronchial obstruction. Emergency thoracotomy and subsequent sulfur hexafluoride (SF6) injections were successfully used to manage her condition. Over the course of follow-up, the interval between SF6 injections was extended from 3 to 11 months, indicating an improvement in the intrathoracic condition. CONCLUSIONS: This case illustrates the efficacy of SF6 gas in treating PPS and in reducing the frequency of medical interventions. SF6 gas administration is safe and effective for the treatment of patients with PPS.
RESUMO
Sulfur hexafluoride (SF6), recognized as a potent greenhouse gas with significant contributions to climate change, presents challenges in understanding its degradation processes. Molecular dynamics simulations are valuable tools for understanding modes of decomposition while the traditional approaches face limitations in time scale and require unrealistically high temperatures. The collective variable-driven hyperdynamics (CVHD) approach has been introduced to directly depict the pyrolysis process for SF6 gas at practical application temperatures, as low as 1600 K for the first time. Achieving an unprecedented acceleration factor of up to 107, the method extends the simulation time scale to milliseconds and beyond while maintaining consistency with experimental and theoretical models. The differences in the reaction process between simulations conducted at actual and elevated temperatures have been noted, providing insights into SF6 degradation pathways. The work provides a basis for the further studies on the thermal degradation of pollutants.
RESUMO
The SF-6D health descriptive system and its second version published in 2020, the SF-6Dv2, is used worldwide for valuing health-related quality of life (HRQoL) for economic evaluation and measuring patient-reported health outcomes. In this study, a valuation tool was developed and applied to create a social value set, comprising 18,750 health state values, for the SF-6Dv2 for New Zealand (NZ). This tool was adapted and extended from the one used to create a social value set for the EQ-5D-5L, a simpler health descriptive system with fewer dimensions and health states. The tool implements the PAPRIKA method, a type of adaptive discrete choice experiment, and a binary search algorithm to identify health states worse than dead and has extensive data quality controls to ensure the validity and reliability of the social value set derived from participants' personal value sets. The tool, accompanied by a short introductory video designed specifically for the SF-6Dv2, was distributed via an online survey to a large representative sample of adult New Zealanders in June-July 2022. The tool's data quality controls enabled participants who failed to understand or sincerely engage with the valuation tasks to be identified and excluded, resulting in the participants being pared down to a sub-sample of 2985 'high-quality' participants whose personal value sets were averaged for the social value set. These results, including participants' positive feedback, demonstrate the feasibility and acceptability of using the tool to value larger health descriptive systems such as the SF-6Dv2. Having successfully created an SF-6Dv2 social value set for NZ, the valuation tool can be readily applied to other countries, used to generate personal value sets for personalised medicine and adapted to create value sets for other health descriptive systems.
Assuntos
Qualidade de Vida , Valores Sociais , Humanos , Nova Zelândia , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Inquéritos e Questionários , Reprodutibilidade dos Testes , Nível de Saúde , Idoso , Psicometria/instrumentação , Psicometria/métodosRESUMO
A considerable debate persists in the literature about whose preferences should be considered in the calculation of quality-adjusted life-years. Some suggest considering only the preferences of the general population, while others advocate for the consideration of those of patients or a combination of both. This study aims to inform and measure the differences in health preferences between cancer patients and the general population in Quebec. A total of 60,976 observations representing the preferences of the general population for various health states were collected and used to develop a new value set using the SF-6Dv2. This value set was generated by combining 34,299 observations with time trade-off (TTO) and 26,677 observations with discrete choice experiment (DCE). Utility scores derived from this value set were compared to those of patients' preferences from a new value set in breast and colorectal patients for the SF-6Dv2. For both patients and the general population, the 'Pain' dimension was the highest contributor to the utility score. However, noticeable differences were observed in the estimates. Estimates of levels 2 and 3 were generally lower for cancer patients, while they were more likely to have greater estimates in severe levels. Significant differences in utility scores were also noticed with the general population showing higher mean utility scores for the same health states. These differences increased as the health states worsened. This study sheds light on the existing differences in preferences between cancer patients and the general population of Quebec for a better consideration in healthcare decision-making.
Assuntos
Neoplasias , Anos de Vida Ajustados por Qualidade de Vida , Humanos , Quebeque , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Neoplasias/psicologia , Preferência do Paciente/psicologia , Preferência do Paciente/estatística & dados numéricos , Adulto , Inquéritos e Questionários , Qualidade de Vida/psicologia , Nível de SaúdeRESUMO
AIM: To assess and compare the measurement properties of EQ-5D-5L and SF-6Dv2 among lymphoma patients in China. METHODS: A face-to-face survey of Chinese lymphoma patients was conducted at baseline (all types) and follow-up (diffuse large B-cell). EQ-5D-5L and SF-6Dv2 health utility scores (HUSs) were calculated using the respective Chinese value sets. Ceiling effect was assessed by calculating the percentage of respondents reporting the optimal health state. Convergent validity of EQ-5D-5L and SF-6Dv2 was assessed using the Spearman rank correlation coefficient (r) with QLQ-C30 as a calibration standard. Known-groups validity of the two HUSs was evaluated by comparing their scores of patients with different conditions; and their sensitivity was further assessed in the known-groups using relative efficiency (RE). Test-retest reliability and responsiveness was tested using ICC and standardized response mean (SRM), respectively. RESULTS: Altogether 200 patients were enrolled at baseline and 78 were followed up. No ceiling effect was found for SF-6Dv2 compared to 24.5% for EQ-5D-5L. Correlation between the two HUSs and with QLQ-C30 score was strong (r > 0.5). Each dimension of EQ-5D-5L and SF-6Dv2 had moderate or greater correlations with similar dimensions of QLQ-C30 (r > 0.35). Both EQ-5D-5L and SF-6Dv2 could only a minority known-groups, and the latter may have better sensitivity. EQ-5D-5L had better test-retest reliability (ICC = 0.939); while both of them were responsive to patients with worsened and improved clinical status. CONCLUSIONS: EQ-5D-5L and SF-6Dv2 were found to have good convergent validity and responsiveness, while EQ-5D-5L had better test-retest reliability and higher ceiling effect. Not enough evidence indicates which of the two measures has better known-group validity and sensitivity.
RESUMO
OBJECTIVE: The objective of this study was to evaluate the psychometric properties of the EQ-5D (3L and 5L) and SF-6Dv2 in a group of Chinese patients with late-on Pompe disease (PD), and compare their performance in this patient group. METHODS: The data used in this study were obtained from a web-based and cross-sectional survey conducted in China. All participants completed the 3L, 5L, and SF-6Dv2. Information about their sociodemographic status and health conditions was also collected. The measurement properties were assessed by examining ceiling and floor effects, evaluating convergent validity, known-group validity, and test-retest reliability (Intraclass correlation coefficient [ICC] and Gwet's AC). RESULTS: A total of 117 PD patients completed the questionnaire. All dimensions of the 3L showed strong ceiling effects, ranging between 17.1 and 42.7%. All three measures showed good test-retest reliability, with ICC values ranging from 0.85 to 0.87. The Gwet's AC values showed that four out of five dimensions of the 3L showed very good agreement. All hypothesized correlations between the 3L, 5L, SF-6Dv2, and items of WHODAS were supported, indicating satisfactory convergent validity. The 5L showed stronger correlations (|r|= 0.53-0.84) with WHODAS than the other two measures. The outcomes of ANOVA indicated that the 5L had higher F-statistics than the 3L and SF-6Dv2, indicating a stronger discriminant ability to differentiate most condition groups. CONCLUSION: The 5L demonstrates lower ceiling and floor effects, higher discriminant ability, and better convergent validity than the SF-6Dv2 and 3L in patients with PD. In addition, the 5L may generate a larger utility gain compared to the other two instruments when conducting cost-effectiveness analysis.
RESUMO
Accurate and efficient quantitative analysis of the decomposition products of the insulating medium SF6 in gas-insulated switchgear (GIS) is important for an effective assessment of its internal insulation status. In this work, a quantitative calibration model of Fourier Transform Infrared Spectroscopy (FTIR) combined with SCARS-DNN (Stability Competitive Adaptive Reweighted Sampling-Deep Neural Network) is proposed for the rapid non-destructive detection of SF6 decomposition products. First, the interference of the background gas SF6 on the absorption spectra of the decomposition products is eliminated according to the Lambert-Beer law, while baseline correction and Savitzky-Golay (S-G) smoothing are used to remove baseline drift and noise. Subsequently, a Monte Carlo cross-validation method is used to detect and eliminate the anomalous samples. Then feature selection is performed using uninformative variable elimination (UVE) and stability competitive adaptive reweighted sampling (SCARS), and finally quantitative calibration models of FULL-DNN (full spectral band), UVE-DNN, and SCARS-DNN are developed. For the quantitative detection of SF6 decomposition products, the SCARS-DNN model had the best prediction performance with a maximum reduction of 96.18% in the root mean square error (RMSE) and 96.11% in the mean absolute percentage error (MAPE). Results reveal that the relative errors are basically kept below 1.36% when predicting the three decomposition products, even in the presence of a high level of SF6 interference. Therefore, the SCARS-DNN model is suitable for high-precision quantitative detection of SF6 decomposition gas.
RESUMO
AIM: This paper reports the first estimation of an SF-6D value set based on the SF-12 for Spain. METHODS: A representative sample (n = 1020) of the Spanish general population valued a selection of 56 hypothetical SF-6D health states by means of a probability lottery equivalent (PLE) method. The value set was derived using both random effects and mean models estimated by ordinary least squares (OLS). The best model was chosen on the basis of its predictive ability assessed in terms of mean absolute error (MAE). RESULTS: The model yielding the lowest MAE (0.075) was that based on main effects using OLS. Pain was the most significant dimension in predicting health state severity. Comparison with the previous SF-6D (SF-36) model estimated for Spain revealed no significant differences, with a similar MAE (0.081). Nevertheless, the new SF-6D (SF-12) model predicted higher utilities than those generated by the SF-6D (SF-36) scoring algorithm (minimum value - 0.071 vs - 0.357). CONCLUSION: A value set for the SF-6D (SF-12) based on Spanish general population preferences elicited by means of a PLE technique is successfully estimated. The new estimated SF-6D (SF-12) preference-based measure provides a valuable tool for researchers and policymakers to assess the cost-effectiveness of new health technologies in Spain.
RESUMO
With the clarification of the CO2 abatement targets and pathways, the management and control of non-CO2 greenhouse gases (GHGs) have been widely emphasized. As the potent GHGs restricted by the Kyoto Protocol, methane (CH4) and sulfur hexafluoride (SF6) emissions contribute to a significant and increasing share of the total global GHG emissions, resulting in a continuous impact on the environment. Hence, the abatement of CH4 and SF6, the potent GHGs, is a matter of urgency. This paper focuses on recent advances in abatement of lean CH4 and SF6 waste gas. Firstly, a systematic review of abatement technologies for lean CH4 is presented, and two methods, namely, pressure swing adsorption and catalytic combustion, are emphasized. Additionally, the current status of four mainstream methods such as adsorption separation, thermal (catalytic) degradation, photocatalytic degradation, and non-thermal plasma degradation, as well as emerging technologies for SF6 abatement are summarized, and the inherent shortcomings and industrialization potentials of each technology are analyzed from multiple perspectives. This review demonstrates that, under dual-carbon target, existing abatement technologies are inadequate to meet the complex and diverse demands of the power and coal industries. There are many drawbacks for lean CH4 abatement technologies such as high investment in utilization devices, low processing capacity, high operating cost and requirement of high CH4 concentration. Degradation technologies for SF6 waste gas also suffer from low energy efficiency, high investment in catalytic degradation devices, and secondary pollution of degradation products. Based on this, two large-scale processing schemes with high feasibility are proposed. Finally, the current research hotspots, challenges, and future directions are put forward. This review aims to contribute some new perspectives to the abatement efforts of non-CO2 GHGs, so that the dual-carbon target can be realized as soon as possible.
RESUMO
OBJECTIVES: The SF-6Dv1 is a preference-based measure derived from the SF-36 for use in quality-adjusted life-year estimation for cost-utility analysis. Country-specific value sets for SF-6Dv1 are needed to reflect societal preferences but none are available for Lebanon and other Arabic countries. This study aimed to generate a value set for SF-6Dv1 for Lebanon and to compare results with the UK set. METHODS: A sample of 249 health states defined by the SF-6Dv1 were valued by a representative sample of 577 members of the Lebanon general population, using standard gamble. Several multivariate regression models at mean and individual level were fitted to estimate utilities for all SF-6Dv1 states with selection of best fitting models based on predictive ability, consistency, and model fit. The best fitting models were compared with those fitted in the UK study. RESULTS: Data from 553 eligible respondents providing 3308 valuations were used for the analysis. Lebanese values were consistently higher than UK values, indicating differences in preferences, and there were no negative values. The random effects model using only main effects was the best performing model. There were inconsistencies in 2 dimensions, thereby consistent models were estimated with values ranging from 0.367 to 1. The results are consistent with the UK results. CONCLUSIONS: This study provides the first population-based value set for SF-6Dv1 health states for Lebanon, making it possible to generate quality-adjusted life-years for cost-utility analysis studies. The potential for applications of a standardized utility measure is enormous both in Lebanon and all Arab countries.