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1.
The present work aims to study the impact of O and N addition on Cr-sputtered coatings on plastic (polycarbonate, PC) used in automobile parts, as a promisor alternative for auto part metallization, while eliminating the usage of toxic hexavalent chromium. The coatings were deposited using DC magnetron sputtering from a single pure Cr target in a reactive atmosphere (N2 and/or O2). The deposition of the coatings was performed maintaining the total pressure constant and close to 1 Pa by tuning Ar pressure while reactive gases were added. The target current density was kept at JW = 20 mA·cm−2. Structural characterization revealed a mixture of α-Cr, δ-Cr, β-Cr2N, and CrN crystalline structures as well as amorphous oxides. The coating hardness ranged from 9 GPa for the CrON coating to 15 GPa for the CrN coating. All deposited coatings showed a particularly good interface adhesion; adjusting the amount of O and N made it possible to tune the optical properties of the Cr-based coatings as desired. The promising results open future industrialization of sputtered Cr-based coatings for automotive industries.  相似文献   

2.
Carbon–chromium carbide–chromium multilayer coatings were deposited by utilizing reactive high-power impulse magnetron sputtering with alternating various ratios of ethyne and argon mixtures under a constant total deposition pressure, target pulse frequency, pulse duty cycle, average chromium target power, and total deposition time. Two different alternating gas mixture periods were applied to obtain films with different numbers of layers and lamination thicknesses. The results show that the reduction in the modulation period effectively affects the elastic modulus and the subsequent ratio of hardness to elastic modulus (H/E) of the whole coating, which helps adapt the elastic strain in the coating. This improves the adhesion strength and wear resistance of coatings at room temperature. However, with the increase in wear test temperature, the difference between the wear behaviors of two types of coatings becomes inconspicuous. Both types of coatings lose the wear resistance due to the decomposition of hydrocarbon and the oxidation of the chromium content in the films.  相似文献   

3.
The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.  相似文献   

4.
OBJECTIVE: To estimate the cost of illness in an incidence based cohort of patients with juvenile idiopathic arthritis. METHODS: Direct costs (healthcare and non-healthcare costs) and indirect costs (productivity loss due to sick leave and work disability) were measured in 215 JIA patients, assessed on an average of 17 years after disease onset. Assessment included a clinical evaluation, a structured interview, and two self completion questionnaires. Annual direct costs were estimated based on the reported use of healthcare services and resources, using average unit prices. Indirect costs were estimated from the number of work days missed-that is, using the human capital approach. RESULTS: The mean total cost of late JIA was estimated to be 3500 per patient and year, of which the direct cost contributed more than half. Patients with still active disease (55%) incurred the major share (90%) of the cost. They had a mean total cost of 5700 per patient year, with those under rheumatological care incurring a cost of 9300. Having a certain JIA subgroup, functional disability, or receipt of specialised care independently contributed to the total cost in active JIA. Highest mean total costs were found in active seropositive polyarthritis (17 000) and extended oligoarthritis (11 000), while the lowest were found in active enthesitis related arthritis (1500) and persistent oligoarthritis (2700). CONCLUSIONS: Estimated 12 month costs in late JIA are considerable, differing among the various JIA subgroups. Treatment strategies in JIA should be analysed for their cost effectiveness in the long term.  相似文献   

5.
Silicon and silicon nitride (Si3N4) are some of the most appealing candidates as anode materials for LIBs (Li-ion battery) due to their favorable characteristics: low cost, abundance of Si, and high theoretical capacity. However, these materials have their own set of challenges that need to be addressed for practical applications. A thin film consisting of silicon nitride-coated silicon on a copper current collector (Si3N4@Si@Cu) has been prepared in this work via RF magnetron sputtering (Radio Frequency magnetron sputtering). The anode material was characterized before and after cycling to assess the difference in appearance and composition using XRD (X-ray Powder Diffraction), XPS (X-ray Photoelectron Spectroscopy), SEM/EDX (Scanning Electron Microscopy/ Energy Dispersive X-Ray Analysis), and TEM (Transmission Electron Microscopy). The effect of the silicon nitride coating on the electrochemical performance of the anode material for LIBs was evaluated against Si@Cu film. It has been found that the Si3N4@Si@Cu anode achieved a higher capacity retention (90%) compared to Si@Cu (20%) after 50 cycles in a half-cell versus Li+/Li, indicating a significant improvement in electrochemical performance. In a full cell, the Si3N4@Si@Cu anode achieved excellent efficiency and acceptable specific capacities, which can be enhanced with further research.  相似文献   

6.
An important element in the correct operation of the rolling mill is appropriate planning of the condition of the rolls because this factor constitutes a limiting element in the production process. In this work, with the aim of indicating the method of proper use of production tools–metallurgical rollers during their operation in a Polish rolling mill, the wear and tear of particular kinds of rollers built in the whole rolling set was determined. For this purpose, data were collected at the strip mill from grinding processes, production reports and roll files, while our statistical analysis, laboratory calculations and measurements were used. These data were used to perform computer calculations on the service life of metallurgical rollers installed in the rolling line. Wear mechanisms were identified in industrial practice. The characteristic features of roller wear were investigated using non-destructive tests, including eddy currents. The laboratory tests reproduced the wear mechanisms in very hot rolling rolls. The statistical method for determining the service life of working rolls indicated that their reconstruction is determined both by natural physical phenomena and inappropriate use in about 30% of cases, mainly in the F5 and F6 cages of the finishing unit. Calculations indicated the possibility of replacing the working rolls made of high chromium cast iron Hi-Cr with those made of HSS in the F5 and F6 cages, which will contribute to an increase in the durability of the rolls, a reduction in production costs and a decrease in the number of roll rebuildings. The service life of HSS rolls is 14,000–20,000 Mg of rolled material per 1 mm of wear on its surface in the radial direction, compared to 2000 Mg for rolls made of high chromium cast iron Hi-Cr. The constructed model may be a source of information for further analyses and decision-making processes supporting the management of metallurgical enterprises. On the basis of the constructed model, it was shown that the analyzed projects, depending on their type and technical specification, will bring measurable economic benefits in the form of reduced annual energy consumption and environmental benefits in the form of reduced carbon dioxide emissions into the atmosphere. The constructed model of the roll consumption, verified in the real conditions of the rolling mills, will contribute to the fulfillment of energy and emission obligations with the EU.  相似文献   

7.
OBJECTIVE: To analyze the annual cost of rheumatoid arthritis (RA) and its predictive factors. METHODS: Data were obtained from a 12-month retrospective cohort of 201 RA patients, randomly selected from a rheumatology registry, through a structured interview and records of the Central Information System of the hospital. Results were divided into direct, indirect, and total costs in 2001 US dollars. A sensitivity analysis was performed. Multiple linear regression models for the different types of costs were carried out. RESULTS: The total cost was US dollars 2.2 million per year, with a cost attributable to RA of US dollars 2.07 million per year. The average cost per patient was US dollars 10419 per year (ranging from US dollars 7914 per patient per year in the best scenario to US dollars 12922 per patient per year in the worst case). Direct costs represent nearly 70% of total costs. We found an average increment in total costs of US dollars 11184 per year per unit of Health Assessment Questionnaire (HAQ) score (P < 0.0001) and an average annual increment of US dollars 621 per year of disease (P < 0.0001). After adjustment, the HAQ score, inability to perform housework tasks, and being permanently disabled for work were the only predictors of high costs. CONCLUSION: Our data show a remarkable economic impact of RA over society and link the costs of the disease to its consequences in terms of functional disability, work disability, and housework disability.  相似文献   

8.
Currently, electric vehicles are a rapidly growing alternative to those with combustion engines and can contribute to reduction of CO2 emissions in the transport sector, especially when the energy to power electric motors is predominantly derived from renewable sources. Until now, the comparison of environmental impact and influence of electric transport means on the power systems was not fully addressed in the case of Poland. The purpose of the study is to describe, analyse and assess electric vehicles (EV) operation against performance indicators in Poland, especially the influence of electric transport means (ETM) (electric cars, trams, trolley buses and buses) on power system and environment. The influence on the power system was investigated for the Polish National Powers system using the simulation of different scenarios of loads generated by EV charging. The energy demand of the National Power System and daily load variability indices were determined. Based on the data of ETM powers consumption and emissions of energy production, the emissions of harmful gases per one km and per one person were calculated, as well as the financial outlays for energy necessary to drive 1 km per 1 passenger. To assess and compare the environmental impact of the selected ETM life cycle, the life cycle assessment method was used. The results of environmental impacts were determined for selected assessment methods: CML 2 and IPCC 2013 GWP 100. The functional unit in this study is one selected ETM with a service life of 100,000 km. Comparison of trams, trolley buses, buses and electric passenger cars indicates that most beneficial are electric buses which do not need rails or overhead lines, thus investment costs are lower.  相似文献   

9.
OBJECTIVES: To compare the costs of mobile and stationary mammography and examine the incremental cost-effectiveness of using mobile mammography to increase screening rates.
DESIGN: A cost-effectiveness analysis was performed using effectiveness data from a randomized clinical trial and modeling of costs associated with the mobile mammography intervention.
SETTING: The trial involved 60 community-based meal sites, senior centers, and clubs.
PARTICIPANTS: Four hundred ninety-nine individuals were enrolled in the study, of whom 463 had outcome data available for analysis.
MEASUREMENTS: Costs were calculated for stationary and mobile mammography, as well as costs due to differences in technology and film versus digital. Incremental cost-effectiveness (cost per additional screen) was modeled, and sensitivity analysis was performed by altering efficiency (throughput) and effectiveness based on subgroup data from the randomized trial.
RESULTS: The estimated annual costs were $435,162 for a stationary unit, $539,052 for a mobile film unit, and $456, 392 for a mobile digital unit. Assuming mobile units are less efficient (50% annual volume), the cost per screen was $41 for a stationary unit, $86 for a mobile film unit, and $102 for a mobile digital unit. The incremental cost per additional screen were $207 for a mobile film unit and $264 for a mobile digital unit over a stationary unit.
CONCLUSION: Although mobile mammography is a more effective way to screen older women, the absolute cost per screen of mobile units is higher, whereas the reimbursement is no different. Financial barriers may impede the widespread use of this approach.  相似文献   

10.
OBJECTIVE: To investigate 1) the magnitude of indirect costs, 2) changes in cost components, and 3) correlations between changes in cost and social, clinical, and occupational variables within the first 3 years of rheumatoid arthritis (RA). METHODS: We evaluated the indirect costs per person-year in 133 consecutive gainfully employed out-patients with early RA, in a prospective multicenter followup study. Costs due to RA-related sick leave, work disability, and other work loss were assessed using the human capital approach. Variables associated with reduction in lost productivity were tested by multivariate logistic regression analysis. RESULTS: Mean +/- SEM annual indirect costs were $11,750 +/- 1,120 per person. During the 3-year period of observation, a marked reduction in the costs associated with sick leave was seen, which exceeded the increase in costs due to work disability and other work loss. This phenomenon resulted in an overall reduction in indirect costs of 21%. The final logistic regression model of reduced loss of productivity included 3 variables: no problems with standing (odds ratio [OR] 7.1), no problems with working speed (OR 4.1), and no problems with outdoor work (OR 3.1). CONCLUSION: High indirect costs in early RA were demonstrated. An overall decrease of costs can be seen in the first 3 years, due to the reduction in sick leave. Since the absence of problems due to strenuous working conditions was found to be associated with a reduction in indirect costs, it is assumed that early intensified vocational rehabilitation, apart from controlling disease activity by adequate treatment, might help to reduce indirect costs.  相似文献   

11.
We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO(2) emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent.  相似文献   

12.
The TaC, HfC, and Hf-Ta-C coatings are successfully prepared by non-reactively DC magnetron sputtering. The effects of working pressure and deposition temperature on the structure and mechanical properties of Ta-Hf-C coating are analyzed. The scratch performance of the Ta-Hf-C coating deposited on 304 stainless steel and tungsten substrates are investigated. Results show the hardness and elastic modulus of Ta-Hf-C solid solution coating both increase to 37.8 ± 1.1 GPa and 435.8 ± 13.8 GPa due to the solid solution strengthening effect. Plastic deformation resistance H3/E2 of Ta-Hf-C coating can reach 0.285, which is more than twice that of binary coating. Furthermore, the scratch performance and failure mechanism show that Ta-Hf-C coating has a weaker plastic deformation resistance on soft substrate and low friction characteristic (0.01) on hard substrate, which implies that Ta-Hf-C coating is a good protective coating that can be applied to cutting tools.  相似文献   

13.
Machining operations are very common for the production of auto parts, i.e., connecting rods, crankshafts, etc. In machining, the use of cutting oil is very necessary, but it leads to higher machining costs and environmental problems. About 17% of the cost of any product is associated with cutting fluid, and about 80% of skin diseases are due to mist and fumes generated by cutting oils. Environmental legislation and operators’ safety demand the minimal use of cutting fluid and proper disposal of used cutting oil. The disposal cost is huge, about two times higher than the machining cost. To improve occupational health and safety and the reduction of product costs, companies are moving towards sustainable manufacturing. Therefore, this review article emphasizes the sustainable machining aspects of steel by employing techniques that require the minimal use of cutting oils, i.e., minimum quantity lubrication, and other efficient techniques like cryogenic cooling, dry cutting, solid lubricants, air/vapor/gas cooling, and cryogenic treatment. Cryogenic treatment on tools and the use of vegetable oils or biodegradable oils instead of mineral oils are used as primary techniques to enhance the overall part quality, which leads to longer tool life with no negative impacts on the environment. To further help the manufacturing community in progressing towards industry 4.0 and obtaining net-zero emissions, in this paper, we present a comprehensive review of the recent, state of the art sustainable techniques used for machining steel materials/components by which the industry can massively improve their product quality and production.  相似文献   

14.
Duplex stainless steels are being used on applications that require high corrosion resistance and excellent mechanical properties, such as the naval and oil-gas exploration industry. The components employed in these industries are usually obtained by machining; however, these alloys have low machinability when compared to conventional stainless steels, usually requiring the employment of tool coatings. In the present work, a comparative study of TiAlSiN coating performance obtained by these two techniques in the milling of duplex stainless-steel alloy LDX 2101 was carried out. These coatings were obtained by the conventional direct current magnetron sputtering (dc MS) and the novel high power impulse magnetron sputtering (HiPIMS). The coatings were analyzed and characterized, determining mechanical properties for both coatings, registering slightly higher mechanical properties for the HiPIMS-obtained coating. Machining tests were performed with varying cutting length and feed-rate, while maintaining constant values for axial and radial depth of cut and cutting speed. The surface roughness of the material after machining was assessed, as well as the wear sustained by each of the tool types, identifying the wear mechanisms and behavior of these tools, as well as registering the flank wear values presented for each of the tested tools. The HiPIMS-obtained coating exhibited a very similar behavior when compared to the other, producing similar surface roughness quality. However, the HiPIMS coating exhibited less wear for higher cutting lengths, proving to be a better choice in this case, especially regarding tool life.  相似文献   

15.
Background and aims The objective of this work is to evaluate the health care utilization and cost of different types of functional bowel disorder (FBD) in a population of Iranian patients and compare the costs in consulters and non-consulters. Materials and methods A consecutive sample of 1,023 patients in an outpatient gastroenterology clinic in central Tehran were interviewed, using two questionnaires based on the Rome II criteria, from December 2004 to May 2005 to detect FBD patients and to determine the frequency of health resource utilization (physician visit, hospitalization, laboratory tests, imaging studies, and drugs) and productivity loss (days off work or with low functionality) due to FBD symptoms in the past 12 months. Societal perspective was used and cost per person per year was estimated in purchasing power parity dollars (PPP$). Results The direct costs (for consulters, non-consulters; data presented in this order) were: irritable bowel syndrome (IBS; $92.04, $1.04), unspecified functional bowel disorder (FBD; $100.94, $0.39), functional constipation ($57.23, $1.04), and functional abdominal bloating ($71.35, $0.63). Indirect costs (for consulters, non-consulters) were: IBS ($811.85, $669.09), unspecified FBD ($705.85, $263.47), functional constipation ($587.48, $97.49), and functional abdominal bloating ($147.88, $38.60). Total yearly costs of IBS and functional constipation for urban adult population of Iran were roughly estimated at 2.94 billion PPP$ and 89.2 million PPP$, respectively. Conclusions As proven in developed countries, FBD and especially IBS seem to put a heavy burden on the economy of a developing country like Iran. Further population-based studies are needed for more precise estimations.  相似文献   

16.

Objective

To analyze the annual cost of rheumatoid arthritis (RA) and its predictive factors.

Methods

Data were obtained from a 12‐month retrospective cohort of 201 RA patients, randomly selected from a rheumatology registry, through a structured interview and records of the Central Information System of the hospital. Results were divided into direct, indirect, and total costs in 2001 US dollars. A sensitivity analysis was performed. Multiple linear regression models for the different types of costs were carried out.

Results

The total cost was $2.2 million per year, with a cost attributable to RA of $2.07 million per year. The average cost per patient was $10,419 per year (ranging from $7,914 per patient per year in the best scenario to $12,922 per patient per year in the worst case). Direct costs represent nearly 70% of total costs. We found an average increment in total costs of $11,184 per year per unit of Health Assessment Questionnaire (HAQ) score (P < 0.0001) and an average annual increment of $621 per year of disease (P < 0.0001). After adjustment, the HAQ score, inability to perform housework tasks, and being permanently disabled for work were the only predictors of high costs.

Conclusion

Our data show a remarkable economic impact of RA over society and link the costs of the disease to its consequences in terms of functional disability, work disability, and housework disability.
  相似文献   

17.
Lithium (Li) is one of the commonly used target materials for compact accelerator-based neutron source (CANS) to generate neutrons by 7Li(p, n)7 Be reaction. To avoid neutron yield decline caused by lithium target reacting with the air, a titanium (Ti) coating was deposited on the lithium target by magnetron sputtering technology. The color change processes of coated and bare lithium samples in the air were observed and compared to infer the chemical state of lithium qualitatively. The surface topography, thickness, and element distribution of the coating were characterized by SEM, EDS and XPS. The compositions of samples were inferred by their XRD patterns. It was found that a Ti coating with a thickness of about 200 nanometers could effectively isolate lithium from air and stabilize its chemical state in the atmosphere for at least nine hours. The Monte Carlo simulations were performed to estimate the effects of the Ti coating on the incident protons and the neutron yield. It turned out that these effects could be ignored. This research indicates that depositing a thin, titanium coating on the lithium target is feasible and effective to keep it from compounds’ formation when it is exposed to the air in a short period. Such a target can be installed and replaced on an accelerator beam line in the air directly.  相似文献   

18.
An extensive literature on substance abuse and mental health treatments suggests that they often lead to decreased usage and/or spending on other medical treatments. We compare alcohol and drug abuse treatment costs with a model that decomposes total treatment costs into amount of treatment (outpatient visits or inpatient days) and costs per treatment. The analysis compares alcohol and drug abuse treatment costs regarding: (1) the incremental costs attributable to changed short-term substance abuse and nonsubstance abuse treatments; (2) the impacts of current substance abuse treatments on short-term nonsubstance abuse, long-term substance abuse, and long-term nonsubstance abuse treatments; and (3) the difference in inpatient and outpatient impacts. Our findings indicate that alcoholism and drug abuse treatment initiation have similar impacts on coincident and subsequent utilization and costs. For both treatments, the largest portions of the cost impacts occur for inpatient treatments, and for treatments that occur within 6 months of the initiation. The similarity of results suggests that it may often be reasonable to infer utilization and cost impacts for one type of care from studies that examine the other.  相似文献   

19.
The objectives of this retrospective study were to assess the economic impact that the practice of 'family replacement donor system' has on the operational costs of a rural blood bank and to rationalize efficient blood screening protocols with a view to minimizing blood screening costs without compromising blood safety. Prevalence of transfusion-transmissible infections such as HIV, hepatitis B and syphilis were ascertained from records of 870 potential donors screened over a period of 6 months. Costs of screening tests were approximated by summing up costs of materials used per test. Overhead and labour costs were not factored in. Average and marginal costs of a fully-screened blood unit were calculated using different blood screening protocols. The average and marginal costs of a fully-screened blood unit vary greatly depending on the order in which screening tests are conducted. Although the variation in average costs per blood unit among different protocols is narrow, US 29.44 dollars to US 33 dollars, the variation in marginal costs is significantly wider ranging from US 22.79 dollars to US 51.85 dollars. Overall, 78 (9%) of the potential donors had HIV infection while 25 (3.2%) had hepatitis B infections and nine (1.2%) donors had syphilis. Co-infection rate was very low at 1.4%. The study shows that it is possible to prioritize blood screening tests for the selection of safe blood donors simply and cost-effectively in a developing country hospital. In the face of rapid rises in health-care spending, it is very important that essential health services such as blood screening are safely delivered with as little expenditure of financial resources as possible. To make sound economic decisions, average cost is not what matters but marginal cost, the cost of one more test.  相似文献   

20.
The objective was to assess the cost-effectiveness of various DMARDs compared with antimalarials (AM) for rheumatoid arthritis (RA) treatment. The data on disease activity, functional status and societal costs were collected from a 1-year cohort of 152 patients with RA receiving at least one DMARD for ≥ 6 months. Incremental cost effectiveness ratio (ICER) was calculated from the societal costs of DMARD treatment compared with AM per one unit of HAQ improvement. All costs were presented in 2001 US dollars. Mean (SD) societal cost of AM treatment was US$ 2,285 (1,154) per patient per year. MTX + AM was less costly and more effective than AM, as the ICER of this combination would save US$ 834 per 1 U of HAQ improvement. MTX + SSZ, leflunomide, and triple therapy (AM + MTX + SSZ) were more effective than AM with additional costs. RA treatment with non MTX-based DMARDs was not cost-effective.  相似文献   

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