Vintage Model Research Articles

A vintage ophthalmoscope

traces the development of the ophthalmoscope and describes a vintage model in his possession

Supercapacitor based cost effective hybrid energy storage system with reduction in battery size for diesel generator cold cranking

The supercapacitor characteristic of high-power delivery coupled with very fast charge/discharge cycles find its use in hybrid energy storage systems. In this paper, the supercapacitor bank is integrated with small capacity lead-acid battery for the development of cost-effective hybrid energy storage system to crank vintage model of diesel-generator. The developed system uses microcontroller-based controls with active voltage balancing circuit with reliable cranking, enhanced battery life and reduced failures at low temperatures are the advantages of the developed system. The developed system resulted in battery size reduction by almost 80%, and thus, reduction in its replacement cost, besides devising a general formula for the sizing of supercapacitor bank for different diesel generators is an innovative outcome of the research study. The multiple cold cranking in a single charge of supercapacitor bank is another novelty, with the charging of supercapacitor bank from the available automobile battery is the added feature in the developed hybrid energy storage system. The developed system paves the ways for the reduced maintenance.

Weather potential for high-quality still wine from Chardonnay viticulture in different regions of the UK with climate change

UK viticulture is benefitting from climate change with an increase in vineyard area and a move towards French grapevine varieties, primarily Chardonnay and Pinot noir, to produce sparkling wine. Doubt remains, however, as to how good UK still wine can be from these varieties. The simple Chablis vintage model uses only three climatic indices: mean temperature from April to September, mean minimum temperature in September (cool night index) and total rainfall from June to September. It was applied to the UK for the periods 1981–2000, 2010–2019 and, with climate change projections, to 2040–2059 to locate sites in the UK with the climate potential to produce high-quality Chardonnay still wine. Weather data for 1981–2000 and 2010–2019 were taken from the Met Office’s HadUK-Grid at a resolution of 5 × 5 km, and climate projections for 2040–2059 were derived from UKCP18, using intermediate emission scenario RCP 4.5 at the 5th, 50th and 95th percentile probabilities. Recent and current climatic conditions throughout most of the UK were unsuitable for sustainable production of high-quality still Chardonnay wine (only 0.2 to 1.8 % of UK land area suitable), but model scores corresponded with high-quality Chardonnay still wine production observed in some regions of England in 2018. Under the 5th percentile RCP 4.5 projection for 2040–2059, climatic conditions are similar to 2010–2019 and generally unsuitable for sustainable, high-quality still Chardonnay wine production. Under the median and 95th percentile projections for 2040–2059, however, South East England and East of England have the potential for high-quality still Chardonnay wine production in an average year, and Central England also with the 95th percentile projection. Overall, climate change is expected to benefit the production of high-quality still Chardonnay wine in the medium term, with up to 42.4 % of UK land possibly climatically (but not necessarily agronomically) suitable by mid-century. The model does not account for extreme events, however, and there is uncertainty over future inter-annual weather variability, and so the sustainability of high-quality still wine production. Planting Chardonnay clones suitable for both sparkling and still wines in the most-suitable areas of England would provide flexibility and so resilience.

Investigating the role of surface engineering in mitigating greenhouse gas emissions of energy technologies: An outlook towards 2100

Energy improvements in the energy sector constitute a key strategy to mitigate climate change. These expected improvements increasingly depend on the development of materials with improved surface characteristics. To prospectively assess the large-scale benefits and trade-offs of such novel surface engineering (SE) technology deployments in the energy sector, an integrated modelling framework is proposed. This paper links an integrated assessment model (IAM) forecasting socio-economic changes in energy supply with life cycle assessment (LCA) models of targeted technology candidates. Different shared socio-economic pathway narratives are used with the MESSAGE IAM to forecast future energy supply scenarios. A dynamic vintage model is employed to model plants decommissioning and adoption rates of innovative SE. Potential benefits and impacts of SE are assessed through prospective LCA. The approach is used to estimate the prospective GHG emission reduction potential achieved by large-scale adoption of innovative SE technologies to improve the efficiency of four energy conversion technologies (coal power plants, gas turbines, wind turbines and solar panels) until 2100. Applying innovative SE technologies to the energy sector has the potential of reducing annual CO2-eq emissions by 1.8 Gt in 2050 and 3.4 Gt in 2100 in an optimistic socio-economic pathway scenario. This corresponds to 7% and 8.5% annual reduction in the energy sector in 2050 and 2100, respectively. The mitigation potential of applying innovative SE technologies highly depends on the energy technology, the socio-economic pathways, and the implementation of stringent GHG mitigation policies. Due to their high carbon intensity, fossil-based technologies showed a higher GHG mitigation potential compared to renewables. Besides, GHG emissions related to the SE processes are largely offset by the GHG savings of the energy conversion technologies where the innovative SE technologies are applied.

Penicillium chrysogenum, a Vintage Model with a Cutting-Edge Profile in Biotechnology.

The discovery of penicillin entailed a decisive breakthrough in medicine. No other medical advance has ever had the same impact in the clinical practise. The fungus Penicillium chrysogenum (reclassified as P. rubens) has been used for industrial production of penicillin ever since the forties of the past century; industrial biotechnology developed hand in hand with it, and currently P. chrysogenum is a thoroughly studied model for secondary metabolite production and regulation. In addition to its role as penicillin producer, recent synthetic biology advances have put P. chrysogenum on the path to become a cell factory for the production of metabolites with biotechnological interest. In this review, we tell the history of P. chrysogenum, from the discovery of penicillin and the first isolation of strains with high production capacity to the most recent research advances with the fungus. We will describe how classical strain improvement programs achieved the goal of increasing production and how the development of different molecular tools allowed further improvements. The discovery of the penicillin gene cluster, the origin of the penicillin genes, the regulation of penicillin production, and a compilation of other P. chrysogenum secondary metabolites will also be covered and updated in this work.

Frankenstein Redux

Frankenstein Redux

Products of Interest

Products of Interest

Vintage analysis of Chinese Baijiu by GC and 1H NMR combined with multivariable analysis

Economical-driven counterfeit and inferior aged Chinese Baijiu has caused serious concern of publicity in China. In this study, a total of 167 authentic Chinese Baijiu samples with different vintages including 3 flavor types were carefully collected. Gas chromatography (GC) was used to determine main volatile components and proton nuclear magnetic resonance (1H NMR) spectroscopy was employed to obtain non-targeted fingerprints of Chinese Baijiu samples. Partial least squares regression (PLSR) models, which were confirmed by internal and external validation, were established for effectively identifying actual storage vintage of Chinese Baijiu with various brands, flavor types. Centering (Ctr), pareto scaling (Par), unit variance scaling (UV) data pretreatment methods, principal components (PCs), and three modified variable selection methods were proposed to successfully optimize the vintage model and effectively extract important vintage characteristic factors. This study demonstrated that NMR and GC combined with multivariate statistical analysis are effective tools for validating vintage authenticity of Chinese Baijiu.

Investment and Technical Progress in the G7 Countries and Australia

The vintage model of capital accumulation predicts that technical progress depends on the installation of new capital equipment. In this paper it is found that investment raises labor productivity in the G7 countries and Australia. This finding implies that the decline in investment during the global financial crisis will have a long lasting detrimental effect on labor productivity and hence wages.

Economic Retirement Age and Lifelong Learning: A Theoretical Model With Heterogeneous Labor, Biased Technical Change and International Sourcing

AbstractThe employability of an aging population in a world of continuous and biased technical change is top of the political agenda. Due to endogenous human capital depreciation the effective retirement age is often below statutory retirement age resulting in permanent non-employability of older workers. We analyze this phenomenon in a putty-putty human capital vintage model and focus on education and the speed of human capital depreciation. Introducing a two-stage education system with initial schooling and lifelong learning, not even lifelong learning turns out to be capable of aligning economic and statutory retirement. However, well-designed education programs will keep more workers in highly productive activities at the end of their working life, and hence will substitute for simple social transfers, or for an early switch towards very low paid jobs.

A vintage model with endogenous growth and human capital

AbstractWe develop an endogenous growth model with vintages of physical capital where human capital is endogenously produced. Under some simplifying assumptions, we can solve the model analytically and study its dynamics. We provide conditions under which a balanced growth path, in the ratio of capital to human capital, exists and is stable, with the transition dynamics exhibiting oscillatory echo effects associated with vintages.

Economics of forest carbon storage and the additionality principle

The ability of forests to store carbon is vital in maintaining the preset climate conditions, but is not systematically included in forest management or land-use decisions. Economic reasoning suggests subsidizing carbon storage, but empirical models show that this may easily more than double stand-level bare land values. Subsidization may thus be expensive, as it requires paying for all storage, including what would otherwise be obtained for free. To limit the consumption of public funds, the regulator may apply an additionality principle and solely subsidize storage exceeding a baseline level. We show that the commonly applied stand-level analysis suggests that the additionality principle could be applied to optimal rotation decisions without distortions. However, applying a forest vintage model with endogenous prices and land allocation decisions shows that similar application of the additionality principle causes distortions to both land allocation and optimal forest rotation. Nevertheless, subsidizing carbon storage by forest site productivity tax may still be preferable among the second-best policies. The distortions can be avoided by eliminating excessive subsidies by general land taxation irrespective of whether the land is used for forestry or agriculture.

Economic Retirement Age and Lifelong Learning - A Theoretical Model with Heterogeneous Labor, Biased Technical Change and International Sourcing

The employability of an aging population in a world of continuous and biased technical change is top of the political agenda. Due to endogenous human capital depreciation the effective retirement age is often below statutory retirement age resulting in permanent non-employability of older workers. We analyze this phenomenon in a putty-putty human capital vintage model and focus on education and the speed of human capital depreciation. Introducing a two-stage education system with initial schooling and lifelong learning, not even lifelong learning turns out to be capable of aligning economic and statutory retirement. However, well designed education programs will keep more workers in highly productive activities at the end of their working life, and hence will substitute for simple social transfers, or for an early switch towards very low paid jobs.

Dynamic Relative Standards versus Emission Taxes in a Putty-Clay Model

AbstractThe paper derives the dynamics of pollution taxes and relative standards—which set bounds on emissions per unit of output—and the resulting optimal replacement of capital goods in a vintage model under the putty-clay assumption. Comparing policies that are constrained by the same aggregate pollution target level, the productive life of capital is longer under dynamic relative standards, as the variable cost of pollution imposed on aging capital is lower. As a result, the absolute level of output from the industry is generally higher under dynamic relative standards than under taxes. The results also show, under reasonable assumptions, that the pollution goal will be achieved using cleaner technologies under dynamic relative standards. These results can explain, from a political economy perspective, the prevalence of dynamic relative standards in regulations.

Are distance measures effective at measuring efficiency? DEA meets the vintage model

In this paper I develop a model of capacity expansion that accounts for differences in the productivity of the installed capital due to technical progress exhibited by the ex ante production function. A putty-clay set-up is assumed, meaning flexible input coefficients and substitution possibilities ex ante, but fixed input coefficients ex post. Based on the model, I generate a capacity distribution of DMUs (vintages) describing an industry with a homogeneous output and perform an efficiency analysis employing data envelopment analysis, a popular non-parametric method for estimating efficiency. The results show that in some circumstances older vintages might appear on the efficiency frontier, unlike some newer vintages that are found to be inefficient, despite benefiting from the advancement of the technology.

Comment

Comment

The time profile approach to production with an application to gestation lags

This paper proposes a unified framework to analyse the effect of different features of the time profile of production. The paper starts considering that features as the schedule of capital depreciation or possible installation costs and gestation lags can be analysed together. This is done by a generalisation of the vintage model in the setting proposed by Benhabib and Rustichini (1991) that considers the time profile of production as a whole, putting together the cost of the investment and its in-time consequences. Another direction of this generalisation is to cast it in a case of endogenous growth models. We use this method in the specific case of gestation lags to analyse and give economic meaning to the stability properties of the steady growth solution of consumption, and the non linear dynamics of investment paths associated to this base case of time-to-build.

Are Internal Heat Gains Underestimated in Thermal Performance Evaluation of Buildings?

Improving the energy performance of buildings can contribute substantially to reducing energy demand. To evaluate the useful energy demand for space heating purposes from an energy economics perspective norm-based bottom-up models are applied that capture the energy-related characteristics of buildings. As electricity demand per household attributed to appliances and lighting has increased substantially in the EU27 during the last two decades (+50%), the question arises whether the static norm-based approach is underestimating the contribution of internal heat gains to covering useful energy demand. To analyze the impact of dynamic internal heat gains in the residential sector, a bottom-up vintage model is applied that covers the EU27 building stock with a country-specific typology. This means the internal heat gains are time-dependent and heat dissipation is distinguished by appliances, lighting and residents. The analysis consists of two explorative scenarios for the residential building stock of EU27 until 2050. A reference scenario represents the static norm-based modelling of internal heat gains while the second scenario considers their dynamic development. The study reveals that the norm-based approach underestimates the contribution of internal heat gains to covering thermal heat demand. Comparing the countries throughout the EU27 climate zones indicates that on average the static and the dynamic share of internal heat gains differ in a range from 20-70% by 2050. Especially in the case of nearly Zero-Energy Buildings (nZEB), e.g. with 30 kWh/m2*a useful energy demand, the internal heat gains are about 10-15% higher using the dynamic approach compared to the norm-based approach.

Viability Theory in Population Economics

Set-valued analysis combined with the principles of maintenance and acquisition allow the handling of heterogeneity, uncertainty, and diversity of economic trajectories. It makes models stem from constraints, instead of having an optimum found from a guessed (and often stylized) model. A review of realistic applications at the heart of population economics shows the explanation power of viability theory, including the economic theory of the life cycle, vintage models, the demographic transition, network analysis, population and environment, the origin of preferences, endogenous growth, diffusion. The optimum principle is articulated with viability.

A Vintage Model of Terrorist Organizations

A dynamic model of a terrorist organization is presented with the defining feature being that a succession of operatives is recruited at different points in time. Consequently, a government’s counterterror policy must be tailored according to the vintage structure of the terrorist group that it faces. This implies that past history of counterterror policy and attacks matter for the formulation of current and future policy. The authors present the necessary steps to formulate and solve a vintage model, and to deal with the delay differential equations that naturally arise from the vintage structure. The resulting analysis captures the implications of a diverse set of phenomena such as Internet recruiting, training delays for logistically complex plots, age distribution of operatives, and the sensitivity of government impatience/cabinet composition to terrorist events for the inner dynamics of terrorist organizations and counterterror policy. Directions for future research are also suggested.