Lower Lifetime Costs Research Articles

Impact of battery weight and charging patterns on the economic and environmental benefits of plug-in hybrid vehicles

Plug-in hybrid electric vehicle (PHEV) technology is receiving attention as an approach to reducing US dependency on foreign oil and greenhouse gas (GHG) emissions from the transportation sector. PHEVs require large batteries for energy storage, which affect vehicle cost, weight, and performance. We construct PHEV simulation models to account for the effects of additional batteries on fuel consumption, cost, and GHG emissions over a range of charging frequencies (distance traveled between charges). We find that when charged frequently, every 20 miles or less, using average US electricity, small-capacity PHEVs are less expensive and release fewer GHGs than hybrid electric vehicles (HEVs) or conventional vehicles. For moderate charging intervals of 20–100 miles, PHEVs release fewer GHGs, but HEVs have lower lifetime costs. High fuel prices, low-cost batteries, or high carbon taxes combined with low-carbon electricity generation would make small-capacity PHEVs cost competitive for a wide range of drivers. In contrast, increased battery specific energy or carbon taxes without decarbonization of the electricity grid would have limited impact. Large-capacity PHEVs sized for 40 or more miles of electric-only travel do not offer the lowest lifetime cost in any scenario, although they could minimize GHG emissions for some drivers and provide potential to shift air pollutant emissions away from population centers. The tradeoffs identified in this analysis can provide a space for vehicle manufacturers, policymakers, and the public to identify optimal decisions for PHEV design, policy and use. Given the alignment of economic, environmental, and national security objectives, policies aimed at putting PHEVs on the road will likely be most effective if they focus on adoption of small-capacity PHEVs by urban drivers who can charge frequently.

Dependability-Based Design Optimization of Degrading Engineering Systems

In this paper, we present a methodology that helps select the distribution parameters in degrading multiresponse systems to improve dependability at the lowest lifetime cost. The dependability measures include both quality (soft failures) and reliability (hard failures). Associated costs of scrap, rework, and warrantee work are included. The key to the approach is the fast and efficient creation of the system cumulative distribution function through a series of time-variant limit-state functions. Probabilities are evaluated by Monte Carlo simulation although the first-order reliability method is a viable alternative. The cost objective function that is common in reliability-based design optimization is expanded to include a lifetime loss of performance cost, herein based on present worth theory (also called present value theory). An optimum design in terms of distribution parameters of the design variables is found via a methodology that involves minimizing cost under performance policy constraints over the lifetime as the system degrades. A case study of an over-run clutch provides the insights and potential of the proposed methodology.

Cost-Effectiveness Analysis in Canada of Dasatinib Versus Imatinib for the Treatment of Chronic Myelogenous Leukemia in Patients with Imatinib Resistance.

Objective: To estimate the cost-utility of dasatinib versus high-dose imatinib (HDI, imatinib 800mg/day) for chronic myelogenous leukemia (CML) in patients with resistance to imatinib at standard doses.Methods: We adapted to the Canadian setting a Markov model with a monthly cycle length that followed hypothetical patients until death. Cost effectiveness was evaluated during three phases of CML: chronic (86% of Ontario patients in 2006), accelerated (9%) and blast crisis (5%). Efficacy of dasatinib and HDI (cytogenetic and hematologic response) and adverse events (AEs) were taken from randomized trials. Canadian costs of medications, laboratory tests, professional fees, hospitalizations, and AEs were obtained from published sources. Societal utility scores were estimated from a Canadian time trade-off study. Analyses were performed from the perspective of the Ontario Ministry of Health. Costs (2006 CDN$) and outcomes (QALYs) were discounted at 5% annually after the first year. Univariate and probabilistic sensitivity analyses were carried out to quantify uncertainty for the incremental cost-effectiveness ratios (ICERs).Results: Dasatinib dominated HDI in chronic phase patients with additional QALYs (3.92 vs. 3.47) and a lower lifetime cost ($379,678 vs. $444,934). The ICERs of dasatinib vs. HDI in accelerated and blast phase were $88,098/QALY and $173,922/QALY respectively. The higher cost/QALY of dasatinib in the advanced phases is explained primarily by the increased predicted survival of dasatinib patients and therefore the longer duration of drug therapy for these patients. Parameters with the greatest influence on results were the time horizon, drug costs and utility values. The interpretation of results remained robust in univariate and probabilistic sensitivity analyses.Conclusion: From an economic perspective dasatinib is an attractive treatment choice for the majority of imatinib resistant CML patients and provides better value for money than HDI.

Health-Care Costs Associated with Amputation or Reconstruction of a Limb-Threatening Injury

Recent reports have suggested that functional outcomes are similar following either amputation or reconstruction of a severely injured lower extremity. The goal of this study was to compare two-year direct health-care costs and projected lifetime health-care costs associated with these two treatment pathways. Two-year health-care costs were estimated for 545 patients with a unilateral limb-threatening lower-extremity injury treated at one of eight level-I trauma centers. Included in the calculation were costs related to (1) the initial hospitalization, (2) all rehospitalizations for acute care related to the limb injury, (3) inpatient rehabilitation, (4) outpatient doctor visits, (5) outpatient physical and occupational therapy, and (6) purchase and maintenance of prosthetic devices. All dollar figures were inflated to constant 2002 dollars with use of the medical service Consumer Price Index. To estimate projected lifetime costs, the number of expected life years was multiplied by an estimate of future annual health-care costs and added to an estimate of future costs associated with the purchase and maintenance of prosthetic devices. When costs associated with rehospitalizations and post-acute care were added to the cost of the initial hospitalization, the two-year costs for reconstruction and amputation were similar. When prosthesis-related costs were added, there was a substantial difference between the two groups ($81,316 for patients treated with reconstruction and $91,106 for patients treated with amputation). The projected lifetime health-care cost for the patients who had undergone amputation was three times higher than that for those treated with reconstruction ($509,275 and $163,282, respectively). These estimates add support to previous conclusions that efforts to improve the rate of successful reconstructions have merit. Not only is reconstruction a reasonable goal at an experienced level-I trauma center, it results in lower lifetime costs.

Health-Care Costs Associated with Amputation or Reconstruction of a Limb-Threatening Injury

Background: Recent reports have suggested that functional outcomes are similar following either amputation or reconstruction of a severely injured lower extremity. The goal of this study was to compare two-year direct health-care costs and projected lifetime health-care costs associated with these two treatment pathways. Methods: Two-year health-care costs were estimated for 545 patients with a unilateral limb-threatening lower-extremity injury treated at one of eight level-I trauma centers. Included in the calculation were costs related to (1) the initial hospitalization, (2) all rehospitalizations for acute care related to the limb injury, (3) inpatient rehabilitation, (4) outpatient doctor visits, (5) outpatient physical and occupational therapy, and (6) purchase and maintenance of prosthetic devices. All dollar figures were inflated to constant 2002 dollars with use of the medical service Consumer Price Index. To estimate projected lifetime costs, the number of expected life years was multiplied by an estimate of future annual health-care costs and added to an estimate of future costs associated with the purchase and maintenance of prosthetic devices. Results: When costs associated with rehospitalizations and post-acute care were added to the cost of the initial hospitalization, the two-year costs for reconstruction and amputation were similar. When prosthesis-related costs were added, there was a substantial difference between the two groups ($81,316 for patients treated with reconstruction and $91,106 for patients treated with amputation). The projected lifetime health-care cost for the patients who had undergone amputation was three times higher than that for those treated with reconstruction ($509,275 and $163,282, respectively). Conclusions: These estimates add support to previous conclusions that efforts to improve the rate of successful reconstructions have merit. Not only is reconstruction a reasonable goal at an experienced level-I trauma center, it results in lower lifetime costs. Level of Evidence: Economic and decision analysis, Level II. See Instructions to Authors for a complete description of levels of evidence.

Geosynthetic-wrap around revetments for shore protection

Geosynthetic structures for shore protection have demonstrably lower construction and lifetime costs than those of hard structures. This paper outlines the recent development of a geosynthetic structure that is commonly used for shore protection: geotextile wrap-around revetments (GWRs). Its advantages are also explained. Model tests described in this paper show that these structures are stable against wave action and that their stability can be increased with some simple modifications. Additionally, GWRs have been shown to adapt extremely well against differential settlement and scour erosion. Knowledge obtained from model tests has facilitated the creation of modified design charts. Efficiency of these systems against storm surges, rising sea level, and tsunami is also discussed. Analyses show that many uncertainties involving these structures remain, but that geosynthetic structures should not be regarded as an alternative shore construction method. Rather, they are a preferable solution for numerous coastal problems.

Prevalence, consequences, and determinants of nonadherence in adult renal transplant patients: a literature review

This literature review summarizes the evidence on the prevalence, determinants, clinical and economic consequences of nonadherence with immunosuppressive drugs in renal transplant patients. A literature search yielded 38 articles measuring nonadherence by self-report, collateral report, assay, refill prescriptions or electronic monitoring. The weighted mean prevalence of self-reported nonadherence was 28%. Nonadherence is associated with poor clinical outcomes, contributing to 20% of late acute rejection episodes and 16% of the graft losses (weighted means). In addition, nonadherence results in lower lifetime costs because of shorter survival, yet also in a lower number of quality adjusted life years. Consistent determinants of nonadherence were younger age, social isolation, and cognitions (e.g. low self-efficacy, certain health beliefs). Determinants concerning the health care system/team seem to be under-investigated. Because the evidence summarized in this review is based on older immunosuppressive regimens, further research should focus on prevalence, determinants and consequences of nonadherence with newer immunosuppressive regimens.

Reliability and durability from large heat recovery steam generators

Experience with heat recovery steam generators (HRSGs) designed for larger-heat-input and higher-steam conditions highlights limitations in some features of traditional designs extrapolated from smaller HRSGs that operated predominantly continuously. Many combined-cycle units may be subjected to periods of regular overnight shut-down much earlier than expected and, unless anticipated during the initial design, there will be significant adverse impact on reliability and durability. Very premature problems already experienced on large HRSG designs in combined-cycle and cogeneration applications give an early warning that more widespread problems will arise as HRSGs are subjected to more thermal cycling. Problems that arise when inadequate attention is given to transient conditions over the full range of operation of the combined-cycle gas turbine unit, including at part loads, during shut-downs and restarts from diverse pre-start conditions, are highlighted. The paper gives examples of how the damage to HRSGs during shut-down and starts can be mitigated by minor modifications and sympathetic operating procedures and suggests how prudent purchasers can enhance reliability and lower lifetime costs at a small premium in installed cost by specification of appropriate design features. Other weaknesses which cause problems for operation and maintenance are discussed.

Interval and postabortal contraception with the frameless GyneFix

Intrauterine contraceptive devices (IUDs) have not suffered from the same negative influences in the developing world as in the first world. The method has too many basic advantages to be gainsaid including, most importantly, that it has the lowest lifetime cost of any effective method of contraception, and that user compliance is not an issue once the device is in place.However, the global community is not immune from trends that are seen in selected industrialized countries. Today, better methods of contraception are requested and the discomforts associated with earlier models of IUD, which were once acceptable, are less so today. Faced with the side-effects of oral contraception and the high cost in developing countries, many women who have completed their families undergo surgical sterilization as the only long-term method available to them, notwithstanding severe cultural and economic reservations about doing so.The development of the frameless device is a response to the growing need to develop high-performing, long-acting, reversible and acceptable contraceptives with a high continuation of use and to respond to the urgent need to reverse the legacy of neglect of immediate postabortal family planning.

Costs of HIV+/AIDS at CD4+ counts disease stages based on treatment protocols.

We report treatment protocols for HIV+/AIDS patients by CD4+ counts (T-lymphocyte cells/mm3: > or = 500, 499-200, 199-50, and < 50) as a tool to provide better definition and to project annual costs (total charges for services) and lifetimes costs for HIV+/AIDS. The treatment protocols, derived from the literature and an HIV+/AIDS Physician Panel, defined the resource use associated with antiretroviral therapy and opportunistic disease prophylaxis and treatment. Resource use costs were derived from the published literature, insurance database, Medicare fee schedules, surveys, and the Physician Panel. At CD4+ counts, the rates of opportunistic diseases were derived from the Physician Panel experience; the mean occupancy times were derived from the literature. The sensitivity analysis indicated stability of the lifetime costs to variation in mean occupancy times, rates of opportunistic diseases, rates of adverse events (AE), and costs. The total annual costs (1995 dollars) of HIV+/AIDS patients ranged from $1,934 (> or = 500), $6,015 (200-499), and $9,031 (50-199), to $25,239 ( < 50). The annual costs of opportunistic diseases are esophageal candidiasis (EC) ($2,194), tuberculosis (TB) ($2,924), cryptococcal meningitis (CM) ($17,264), toxoplasmosis ($17,631), Mycobacterium avium complex (MAC) (+20,153), Non-Hodgkin's lymphoma (NHL) ($22,329), wasting syndrome ($26,676), central nervous system (CNS) lymphoma ($27,333), Pneumocystis carinii pneumonia (PCP) [mild ($3,545), moderate ($4,889), and severe ($32,609)], Kaposi' sarcoma (KS) [mild/moderate ($5,902), and severe ($10,744)], and cytomegalovirus (CMV) retinitis ($100,337). The projected lifetime costs of HIV+/AIDS are $94,726 (annual costs $7,645). Our lower lifetime costs as compared with recent estimates may be due to including resources only for HIV+/AIDS-related treatment and not for non-HIV+/AIDS conditions, as well as reduced resource use resulting from more efficient diagnostic and therapeutic techniques and earlier prophylaxis provided by experienced HIV+/AIDS physicians. Nonetheless, our estimates are consistent with decreasing costs of HIV+/AIDS due to a reduction in the average length of stay and frequency of hospitalizations as well as to replacement of inpatient care by outpatient services.

Dish Concentrators for Solar Thermal Energy

A wide variety of point-focusing concentrators are under consideration for solar thermal energy use. They are briefly reviewed in this paper. These concentrators differ in such characteristics as optical configuration and materials, structure for support of the optical elements and receiver, mount, foundation, drive, and controls. Point-focusing concentrators require good optical efficiency and, especially for high-temperature applications, high geometric concentration ratios. Most important are low cost, as installed, and low lifetime cost. Critical cost contributors for quantity production are the cost of materials and the cost of installation labor. Field testing and performance measurements of concentrators, with receivers and controls, are badly needed.

The all-mechanical electric car

Modern flywheel technology could offer a petrol-free, nonpolluting, economical car. The author gives a speculative account of the car of the future. Amongst the advantages listed for the all-mechanical, electric car are: much lower lifetime cost; greatly improved acceleration; many times faster charging time; higher efficiency and improved range; simplified maintenance; improved handling; and temperature independent performance