Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 62
Filtrar
1.
Bull Math Biol ; 86(5): 51, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38581579

RESUMO

Forest plantations are economically and environmentally relevant, as they play a key role in timber production and carbon capture. It is expected that the future climate change scenario affects forest growth and modify the rotation age for timber production. However, mathematical models on the effect of climate change on the rotation age for timber production remain still limited. We aim to determine the optimal rotation age that maximizes the net economic benefit of timber volume in a negative scenario from the climatic point of view. For this purpose, a bioeconomic optimal control problem was formulated from a system of Ordinary Differential Equations (ODEs) governed by the state variables live biomass volume, intrinsic growth rate, and area affected by fire. Then, four control variables were associated to the system, representing forest management activities, which are felling, thinning, reforestation, and fire prevention. The existence of optimal control solutions was demonstrated, and the solutions of the optimal control problem were also characterized using Pontryagin's Maximum Principle. The solutions of the model were approximated numerically by the Forward-Backward Sweep method. To validate the model, two scenarios were considered: a realistic scenario that represents current forestry activities for the exotic species Pinus radiata D. Don, and a pessimistic scenario, which considers environmental conditions conducive to a higher occurrence of forest fires. The optimal solution that maximizes the net benefit of timber volume consists of a strategy that considers all four control variables simultaneously. For felling and thinning, regardless of the scenario considered, the optimal strategy is to spend on both activities depending on the amount of biomass in the field. Similarly, for reforestation, the optimal strategy is to spend as the forest is harvested. In the case of fire prevention, in the realistic scenario, the optimal strategy consists of reducing the expenses in fire prevention because the incidence of fires is lower, whereas in the pessimistic scenario, the opposite is true. It is concluded that the optimal rotation age that maximizes the net economic benefit of timber volume in P. radiata plantations is 24 and 19 years for the realistic and pessimistic scenarios, respectively. This corroborates that the presence of fires influences the determination of the optimal rotation age, and as a consequence, the net economic benefit.


Assuntos
Incêndios , Florestas , Incêndios/prevenção & controle , Conceitos Matemáticos , Modelos Biológicos
2.
J Environ Manage ; 355: 120525, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38437743

RESUMO

Activated carbon (AC), renowned for its versatile applications in water treatment, air purification, and industrial processes, is a critical component in environmental remediation and resource recovery strategies. This study encompasses the process modeling of AC production using anthracite coal as a precursor, involving multiple activation stages at different operating conditions, coupled with a detailed techno-economic analysis aimed at assessing the operational feasibility and financial viability of the plant. The economic analysis explores the investigation of economic feasibility by performing a detailed cashflow and sensitivity analysis to identify key parameters influencing the plant's economic performance, including raw material and energy prices, operational and process parameters. Capital and operational costs are meticulously evaluated, encompassing raw material acquisition, labor, energy consumption, and equipment investment. Financial metrics like Net Present Value (NPV), Internal Rate of Return (IRR), and payout period (POP) are employed, and the results show that AC selling price, raw material cost and plant capacity are the most influential parameters determining the plant's feasibility. The minimum AC production cost of 1.28 $/kg is obtained, corresponding to coal flow rate of 14,550 kg/h. These findings provide valuable insights for stakeholders, policymakers, and investors seeking to engage in activated carbon production from anthracite.


Assuntos
Carvão Vegetal , Recuperação e Remediação Ambiental , Carvão Mineral , Investimentos em Saúde , Plantas
3.
Waste Manag ; 174: 203-217, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38061188

RESUMO

Medical waste (MW) is exploding due to the COVID-19 pandemic, posing a significant environmental threat, and leading to the urgent requirement for affordable and environmentally friendly MW disposal technologies. Prior research on individual MW disposal plants is region-specific, applying these results to other regions may introduce bias. In this study, major MW disposal technologies in China, i.e., incineration technologies (pyrolysis incineration and rotary kiln incineration), and sterilization technologies (steam sterilization, microwave sterilization, and chemical disinfection) with residue landfill or incineration were analyzed from an industry-level perspective via life cycle assessment (LCA), life cycle costing (LCC) and net present value (NPV) methods. Life cycle inventories and economic cost data for 4-5 typical companies were selected from 128 distinct enterprises and academic sources for each technology. LCA results show that microwave sterilization with residue incineration has the lowest environmental impact, emitting only 480 kg CO2 eq. LCC and NPV analyses indicate that steam sterilization with landfilling is the most economical, yielding revenues of 1,210 CNY/t and breaking even in the first year. Conversely, pyrolysis and rotary kiln incineration break even between the 4th and 5th years. Greenhouse gas emissions from the MW disposal in ten cities with the largest MW production in 2020 increased by 7% over 2019 to 43,800 tons and other pollutants increased by 6% to 12%. Economically, Shanghai exhibits the highest cost-effectiveness, while Nanjing delivers the lowest. It can be observed that the adoption of optimal environmental technologies has resulted in a diminution of greenhouse gas emissions by 279,000 tons and energy conservation of 1.76 billion MJ.


Assuntos
Gases de Efeito Estufa , Eliminação de Resíduos de Serviços de Saúde , Resíduos de Serviços de Saúde , Eliminação de Resíduos , Gerenciamento de Resíduos , Humanos , Eliminação de Resíduos de Serviços de Saúde/métodos , Cidades , Vapor , Análise Custo-Benefício , Pandemias , China , Incineração/métodos , Instalações de Eliminação de Resíduos , Eliminação de Resíduos/métodos , Gerenciamento de Resíduos/métodos
4.
J Surg Res ; 291: 527-535, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37540970

RESUMO

INTRODUCTION: Surgical residents make decisions that may have a dramatic impact on career earnings based off conceptions regarding future income potential. This study examines the effect of debt burden, repayment plan, and practice setting on a general surgeon's career value. METHODS: Debt levels, repayment plans, and practice setting were considered to model a surgeon's career value using net present value (NPV) across 35 scenarios. The NPV was calculated using salary, education debt, yearly spending, and a discount rate of 5%. Salary data were obtained from the Medical Group Management Association, student debt information from the Association of American Medical Colleges, and tax and household spending data from U.S. government records. Assumptions included no gaps in training, no prior debt, single-person household, and career duration of 35 y. RESULTS: A general surgeon's salary adequately repays debt burdens from $100,000-$300,000 over 10-25 y, regardless of repayment plan or practice setting. Practice setting decreased career value for academic surgeons when debt burden and repayment plan were held constant: the NPV for an academic surgeon was $382,000 compared to $500,000 for a nonacademic surgeon with the same debt and repayment plan. Debt burden repaid through unsubsidized and income-based repayment plans reduced NPV for all surgeons, while subsidized plans increased NPV. The projected NPV for all scenarios ranged $2.35M-$2.87 M. CONCLUSIONS: Though the modeled scenarios do not account for prior debt burden, major expenditures, or increases in yearly household spending beyond national averages, surgery residents should be aware that general surgery remains a financially feasible career.


Assuntos
Internato e Residência , Cirurgiões , Humanos , Escolha da Profissão , Renda , Salários e Benefícios
5.
Poult Sci ; 102(4): 102507, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36805393

RESUMO

Smaller scale agricultural production for food, income, and as a hobby is a growing trend among United States (US) producers. Laying hens or quail are an economically viable livestock enterprise for small-scale producers with limited resources. In this study, we evaluated the economic feasibility of small-scale egg production (1,000 birds) and compared the profitability under 3 different production systems, and 2 price scenarios. The cost-benefit analysis in this study encompasses calculating and simulating all costs and returns associated with chicken and quail production over a 10-yr period. Two prices were evaluated, farm gate prices that US commercial producers face, and US farmers' market prices more often faced by small-scale producers. In all 3 production scenarios (chicken with the option of natural molting, chicken without molting, and raising quail) small-scale egg production is economically viable when farmers' market egg prices were used to calculate the Net Present Value (NPV). Using farmers' market prices, raising quail has the highest NPV. Raising chickens without molting has the second highest NPV, while raising chickens and allowing them to undergo molting has the lowest NPV. Contrarily, when farm gate egg prices are used in the estimation, only raising quail had a positive NPV. Although the quail enterprise resulted in the highest NPV under both price conditions, there may be marketing difficulties based on the producer's location. Producers located near cities, or Asian populations where quail eggs are more popular may be successful with small-scale quail operations.


Assuntos
Galinhas , Codorniz , Animais , Feminino , Fazendas , Óvulo , Agricultura , Coturnix
6.
Heliyon ; 9(1): e12902, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36685476

RESUMO

This paper presents the technical, financial, and environmental impact assessment of a 50-MW (MW) utility-scale wind farm in Ghana at four locations: Anloga, Atiteti, Sege, and Denu. The monthly average wind speeds recorded at the locations were 6.01 m/s, 5.98 m/s, 5.46 m/s, and 5.17 m/s respectively at 60 m above ground level. Capacity factors of 24.9%, 24.4%, 20.6%, and 18.0% were obtained at the locations respectively. The Net Present Value (NPV) was the main financial metric employed to determine the viability of the projects. The results indicated that a potential utility-scale wind project is viable at all locations under study. Furthermore, the Electricity Exported to the Grid and the Electricity Export Rate (EER) had the highest impact of 0.63 and 0.62 on the NPV respectively and therefore these key parameters should be well considered before any potential project implementation.

7.
J Environ Manage ; 325(Pt A): 116468, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36419299

RESUMO

The number of micro-scale spirit distilleries worldwide has grown considerably over the past decade. With an onus on the distillery sector to reduce its environmental impact, such as carbon emissions, opportunities for increasing energy efficiency need to be implemented. This study explores the potential environmental benefits and financial gains achievable through heat recovery from different process and by-product streams, exemplified for a Scotch whisky distillery, but transferrable to micro-distilleries worldwide. The eco-efficiency methodology is applied, taking into account both climate change and water scarcity impacts as well as economic performance of alcohol production with and without heat recovery. A Life Cycle Assessment, focusing on climate change and water scarcity, is combined with a financial assessment considering investment costs and the present value of the savings over the 20-year service life of the heat recovery system. The proposed heat recovery systems allow carbon emission reductions of 8-23% and water scarcity savings of 13-55% for energy and water provision for 1 L of pure alcohol (LPA). Financial savings are comparatively smaller, at 5-13%, due to discounting of the future savings - but offer a simple payback of the investment costs in under two years. The eco-efficiency of the distillery operations can be improved through all proposed heat recovery configurations, but best results are obtained when heat is recovered from mashing, distillations and by-products altogether. A sensitivity analysis confirmed that the methodology applied here delivers robust results and can help guide other micro-distilleries on whether to invest in heat recovery systems, and/or the heat recovery configuration. Uptake should be enhanced through increased information and planning support, and in cases where the distillery offers insufficient heat and water sinks to use all pre-warmed water, opportunities to link with a heat sink outside the distillery are encouraged. A 10% reduction in heating fuel use through heat recovery has the potential to save 47 kt of CO2 eq. or £7.4 M per annum in United Kingdom malt whisky production alone, based on current fuel types used and current prices (2021).


Assuntos
Temperatura Alta , Água , Etanol , Mudança Climática , Carbono
8.
J Environ Manage ; 326(Pt A): 116679, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36403320

RESUMO

Despite significant drop in pollinator abundance, no studies exist on the benefits and costs of pollinator conservation in the public domain. An in-person survey was conducted at three large, public US universities to estimate benefits to become Bee Campus USA certified. We test whether different types of reminders on existing student sustainability fees affect Willingness to Pay. Costs of achieving this certification per university were obtained. Net Present Value demonstrates that the net benefits to each school are largely positive, except under the most restrictive assumption. Information reminders of existing fees lead to little change in support of pollinator conservation.


Assuntos
Criação de Animais Domésticos , Certificação , Análise Custo-Benefício , Animais , Abelhas , Certificação/economia , Setor Público , Universidades/economia , Criação de Animais Domésticos/economia , Criação de Animais Domésticos/legislação & jurisprudência , Polinização
9.
Ther Innov Regul Sci ; 57(2): 209-219, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36104654

RESUMO

BACKGROUND: Deployment of remote and virtual clinical trial methods and technologies, referred to collectively as decentralized clinical trials (DCTs), represents a profound shift in clinical trial practice. To our knowledge, a comprehensive assessment of the financial net benefits of DCTs has not been conducted. METHODS: We developed an expected net present value (eNPV) model of the cash flows for new drug development and commercialization to assess the financial impact of DCTs. The measure of DCT value is the increment in eNPV that occurs, on average, when DCT methods are employed in comparison to when they are not. The model is populated with parameter values taken from published studies, Tufts CSDD benchmark data, and Medable Inc. data on DCT projects. We also calculated the return on investment (ROI) in DCTs as the ratio of the increment in eNPV to the DCT implementation cost. RESULTS: We found substantial value from employing DCT methods in phase II and phase III trials. If we assume that DCT methods are applied to both phase II and phase III trials the increase in value is $20 million per drug that enters phase II, with a seven-fold ROI. CONCLUSIONS: DCTs can provide substantial extra value to sponsors developing new drugs, with high returns to investment in these technologies. Future research on this topic should focus on expanding the data to larger datasets and on additional aspects of clinical trial operations not currently measured.


Assuntos
Ensaios Clínicos como Assunto , Desenvolvimento de Medicamentos , Desenvolvimento de Medicamentos/economia , Ensaios Clínicos como Assunto/economia
10.
Front Insect Sci ; 3: 1180568, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38469473

RESUMO

Integrated pest management (IPM) strategies are being promoted to suppress tephritid fruit fly infestation and reduce economic damage in mango production. However, research on their economic performance across different mango production scales (measured by the number of mango trees) is limited. This study estimated the economic benefits of IPM practices (parasitoids, orchard sanitation, food bait, biopesticides, male annihilation technique, and their combinations) in Kenya's small-, medium-, and large-scale mango production systems. We used the value-cost ratio (VCR) and net present value methods to estimate the heterogeneous economic performance of IPM practices using data from two unique farm surveys. On average, all IPM practices were profitable across various production scales. However, we found that these practices were more profitable for medium-scale farmers than for small- and large-scale farmers. The results show that farmers need a minimum of 9-17 trees, depending on the practice used, to break even and that there are little to no economic benefits to using IPM practices for farmers with more than 320 mango trees. The male annihilation technique was the most profitable practice, with a VCR of 36, and consequentially, the most adopted practice across all scales of production. Overall, we found significant heterogeneity in the profitability of IPM practices across different scales of production. The reason for the lack of profitability of IPM on large-scale farms remains unclear and warrants further investigation.

11.
Sustainability ; 14(19): 1-33, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36406588

RESUMO

Riparian buffer zones (RBZs) have been shown to be effective best management practices (BMPs) in controlling non-point source pollutants in waterbodies. However, the holistic sustainability assessment of individual RBZ designs is lacking. We present a methodology for evaluating the holistic sustainability of RBZ policy scenarios by integrating environmental and economic indicators simulated in three watersheds in the southeastern USA. We developed three unique sets of 40, 32, and 48 RBZ policy scenarios as decision management objectives (DMOs), respectively, in Back Creek, Sycamore Creek, and Greens Mill Run watersheds (Virginia and North Carolina) by combining the RBZ-widths with vegetation types (grass, urban, naturalized, wildlife, three-zone forest, and two-zone forest). We adapted the RBZ-hydrologic and water quality system assessment data of instream water quality parameters (dissolved oxygen, total phosphorus, total nitrogen, total suspended solids-sediment and biochemical oxygen demand) as environmental indicators, recently published by U.S. EPA. We calculated 20-year net present value costs as economic indicators using the RBZ's establishment, maintenance, and opportunity costs data published by the Natural Resources Conservation Service. The mean normalized net present value costs varied by DMOs ranging from 4% (grass RBZ-1.9 m) to 500% (wildlife RBZ-91.4 m) across all watersheds, due primarily to the width and the opportunity costs. The mean normalized environmental indicators varied by watersheds, with the largest change in total nitrogen due to urban RBZs in Back Creek (60-95%), Sycamore Creek (37-91%), and Greens Mill (52-93%). The holistic sustainability assessments revealed the least to most sustainable DMOs for each watershed, from least sustainable wildlife RBZ (score of 0.54), three-zone forest RBZ (0.32), and three-zone forest RBZ (0.62), respectively, for Back Creek, Sycamore Creek, and Greens Mill, to most sustainable urban RBZ (1.00) for all watersheds.

12.
Data Brief ; 44: 108485, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35966950

RESUMO

This data article contains the location, energy consumption, renewable energy potential, techno-economics, and profitability of hybrid renewable energy systems (HRES) in 634 Philippine off-grid islands. The HRES under consideration consists of solar photovoltaics, wind turbines, lithium-ion batteries, and diesel generators. The islands were identified from Google Maps™, Bing Maps™, and the study of Meschede and Ocon et al. (2019) [1]. The peak loads of these islands were acquired from National Power Corporation - Small Power Utilities Group (NPC-SPUG), if available, or estimated from the island population otherwise. Hourly-resolution load profiles were synthesized using the normalized profiles reported by Bertheau and Blechinger (2018) [2]. Existing diesel generators in the islands were compiled from reports by NPC-SPUG, while monthly average global horizontal irradiance and wind speeds were taken from the Phil-LIDAR 2 database. Islands that are electrically interconnected were lumped into one microgrid, so the 634 islands were grouped into 616 microgrids. The HRES were optimized using Island System LCOEmin Algorithm (ISLA), our in-house energy systems modeling tool, which sized the energy components to minimize the net present cost. The component sizes and corresponding techno-economic metrics of the optimized HRES in each microgrid are included in the dataset. In addition, the net present value, internal rate of return, payback period, and subsidy requirements of the microgrid are reported at five different electricity rates. This data is valuable for researchers, policymakers, and stakeholders who are working to provide sustainable energy access to off-grid communities. A comprehensive analysis of the data can be found in our article "Techno-economic and Financial Analyses of Hybrid Renewable Energy System Microgrids in 634 Philippine Off-grid Islands: Policy Implications on Public Subsidies and Private Investments" [3].

13.
Glob Chall ; 6(7): 2100108, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35860394

RESUMO

This research entails the simulation of three possible power scenarios for Kenya from 2015 to 2035 using low emissions analysis platform (LEAP). These scenarios represent the unfolding future electricity generation that will fully satisfy the demand while considering the following: energy security, power generation cost, and impacts on the environment. These scenarios are reference scenario (RS), coal scenario (CS), nuclear scenario (NS), and more renewable scenario (MRS). The findings obtained reveals that the most sustainable scenario while comparing the costs was found to be the coal scenario with a net present value (NPV) of $30 052.67 million though it has the highest greenhouse gases (GHGs) emissions. However, the more renewable scenario (MRS) has the least GHGs emissions but is found to be the most expensive scenario to implement with an NPV of $30 733.07 million.

14.
Expert Rev Pharmacoecon Outcomes Res ; 22(6): 993-1011, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35488437

RESUMO

BACKGROUND: Selection of a biosimilar development candidate requires detailed and careful analysis to ensure value creation. RESEARCH DESIGN AND METHODS: We applied the net present value (NPV) model for financial evaluation of biosimilar development candidates for the global market. Biosimilar development candidates from three categories were identified based on the global sales of their respective original biological products (OBPs): >$1 and ≤$4 billion, >$4 and ≤$7 billion and >$7 and ≤$10 billion. The standard NPV and risk-adjusted NPV (rNPV) were calculated under the base-case and various scenarios related to development costs, sales, selling, general and administrative expense, cost of goods sold, and discount rates. RESULTS: A biosimilar to an OBP with sales of $1.6 billion has some financial risk. Biosimilars to OBPs with sales of $5.5 billion and $9.4 billion have very less financial risk under the base-case scenario of analysis. Sales of an OBP had impact on the financial valuation and attractiveness of a biosimilar. Sensitivity of rNPV to different parameters varied for three biosimilars. Discount rates, sales and development costs were important parameters affecting financial valuation of biosimilars. CONCLUSION: Biosimilar development candidate selection requires a thorough financial evaluation considering product-, company- and market-specific aspects.


Assuntos
Medicamentos Biossimilares , Humanos
15.
Renew Sustain Energy Rev ; 153: 111786, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34690528

RESUMO

Combating the COVID-19 pandemic has raised the demand for and disposal of personal protective equipment in the United States. This work proposes a novel waste personal protective equipment processing system that enables energy recovery through producing renewable fuels and other basic chemicals. Exergy analysis and environmental assessment through a detailed life cycle assessment approach are performed to evaluate the energy and environmental sustainability of the processing system. Given the environmental advantages in reducing 35.42% of total greenhouse gas emissions from the conventional incineration and 43.50% of total fossil fuel use from landfilling processes, the optimal number, sizes, and locations of establishing facilities within the proposed personal protective equipment processing system in New York State are then determined by an optimization-based site selection methodology, proposing to build two pre-processing facilities in New York County and Suffolk County and one integrated fast pyrolysis plant in Rockland County. Their optimal annual treatment capacities are 1,708 t/y, 8,000 t/y, and 9,028 t/y. The proposed optimal personal protective equipment processing system reduces 31.5% of total fossil fuel use and 35.04% of total greenhouse gas emissions compared to the personal protective equipment incineration process. It also avoids 41.52% and 47.64% of total natural land occupation from the personal protective equipment landfilling and incineration processes.

16.
Entramado ; 17(2): 24-40, jul.-dic. 2021. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1360412

RESUMO

RESUMEN El objetivo es desarrollar un modelo de planeación financiera que permita calcular las ganancias probables de una compañía de alimentos en Colombia, en un horizonte temporal de seis años. La metodología utilizada es el Valor Presente Neto de sus flujos de caja libre, calculados a partir de 38 variables de entrada y de proceso que recogen el aspecto macroeconómico, las políticas financieras y los estados contables. Se realizaron 10.000 iteraciones con la técnica de simulación Montecarlo. Los resultados de la simulación indican que sus ganancias probables están entre $278.293 millones y $449.934 millones con un nivel de confianza del 90%. El análisis de sensibilidad del plan financiero permite concluir que la compañía debe reformular sus políticas financieras relacionadas con la administración del capital de trabajo, dado que la cartera y principalmente los inventarios tienen una influencia negativa sobre el VPN, según los coeficientes de regresión. CLASIFICACIÓN JEL B41, C15


ABSTRACT The goal is to develop a financial planning model that allows calculating the probable profits of a food company in Colombia, in a time horizon of six years. The methodology used is the Net Present Value of its Free Cash Flow, calculated from 38 input and process variables that include the macroeconomic aspect, financial policies and financial statements. 10.000 iterations were carried out with the Montecarlo simulation technique. The simulation results indicate that its probable profits are between $278.293 million and y $449.934 million with a confidence level of 90%. The sensitivity analysis of the financial plan allows to conclude that the company should reformulate its financial policies related to the management of working capital, since the debt clients and mainly the inventories has a negative influence on the Net Present Value, according the regression coefficients. JEL CLASSIFICATION B41, C15


RESUMO O objectivo é desenvolver um modelo de planeamento financeiro que permita calcular os prováveis lucros de uma empresa alimentar na Colômbia, num horizonte temporal de seis anos. A metodologia utilizada é o Valor Presente Líquido dos seus fluxos de caixa livres, calculado a partir de 38 variáveis de entrada e de processo que recolhem o aspecto macroeconómico, as políticas financeiras e as declarações contabilísticas. Um total de 10.000 iterações foram realizadas utilizando a técnica de simulação de Monte Carlo. Os resultados da simulação indicam que os seus prováveis lucros se situam entre $278,293 milhões e $449,934 milhões com um nível de confiança de 90%. A análise de sensibilidade do plano financeiro permite concluir que a empresa deve reformular as suas políticas financeiras relacionadas com a gestão do capital de exploração, uma vez que a carteira e principalmente os inventários têm uma influência negativa no VPL, de acordo com os coeficientes de regressão. CLASSIFICAÇÃO JEL B4I, CI5

17.
J Biopharm Stat ; 31(6): 788-808, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34709137

RESUMO

The discouragingly high rates of attrition in drug development, and in particular in Phase 2, warrant a closer look at the decision criteria applied for investment in the next phase (Phase 3). We have in this article evaluated Stop/Go criteria after Phase 2, based on a model encompassing both Phase 2 and 3, as well as the eventual outcome on the market. The results indicate that the value of a drug project is often maximized if rather liberal decision criteria are applied. The routine adherence to standard criteria, e.g. requiring significance at 5% level, may lead to an unduly high rate of false negative decisions. This might ultimately hamper the productivity of drug development and leading to potentially useful drugs not being taken forward to benefit the intended patients.


Assuntos
Desenvolvimento de Medicamentos , Indústria Farmacêutica , Humanos
18.
Polymers (Basel) ; 13(16)2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34451263

RESUMO

Poly(methyl methacrylate) (PMMA) is a versatile polymer with a forecast market of 4 Mtons/y by 2025, and 6 USD billion by 2027. Each year, 10% of the produced cast sheets, extrusion sheets, or granules PMMA end up as post-production waste, accounting for approximately 30 000 tons/y in Europe only. To guide the future recycling efforts, we investigated the risks of depolymerization process economics for different PMMA scraps feedstock, capital expenditure (CAPEX), and regenerated MMA (r-MMA) prices via a Monte-Carlo simulation. An analysis of plastic recycling plants operating with similar technologies confirmed how a maximum 10 M USD plant (median cost) is what a company should aim for, based on our hypothesis. The capital investment and the r-MMA quality have the main impacts on the profitability. Depending on the pursued outcome, we identified three most suitable scenarios. Lower capital-intensive plants (Scenarios 4 and 8) provide the fastest payback time, but this generates a lower quality monomer, and therefore lower appeal on the long term. On 10 or 20 years of operation, companies should target the very best r-MMA quality, to achieve the highest net present value (Scenario 6). Product quality comes from the feedstock choice, depolymerization, and purification technologies. Counterintuitively, a plant processing low quality scraps available for free (Scenario 7), and therefore producing low purity r-MMA, has the highest probability of negative net present value after 10 years of operation, making it a high-risk scenario. Western countries (especially Europe), call for more and more pure r-MMA, hopefully comparable to the virgin material. With legislations on recycled products becoming more stringent, low quality product might not find a market in the future. To convince shareholders and government bodies, companies should demonstrate how funds and subsidies directly translate into higher quality products (more attractive to costumers), more economically viable, and with a wider market.

19.
Heliyon ; 7(7): e07646, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34381900

RESUMO

In the Russian oil and gas industry, there are still no technical regulations for unified rules and standards governing the establishment of the abandonment fund and the decommissioning of fields. With an increase in the volume of assets decommissioned, the issues of correct accounting and financial reporting of these expenses are becoming more and more urgent. There is also uncertainty regarding the taxation guidelines of operations completion on the production facilities. The strategic aspects of the decommissioning policy of oil and gas fields are stated using the example of the North Sea countries. As part of the responsible investment policy, environmental aspects and industrial safety management during decommissioning of facilities are outlined. An overview of the Russian legislative and regulatory framework is made. Recommendations are given to improve the methodology and practice of abandonment funds management in Russia.

20.
Cureus ; 13(2): e13272, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33728207

RESUMO

Background The factors influencing medical student clinical specialty choice have important implications for the future composition of the US physician workforce. The objective of this study was to determine the career net present values (NPVs) of US medical students' clinical specialty choices and identify any relationships between a specialty's NPV and competitiveness of admissions as measured by the US Medical Licensing Examination (USMLE) Step 1 scores. Methodology NPVs were calculated using the results of the 2019 Doximity Physician Compensation report, a survey of 90,000 physicians. Mean USMLE Step 1 scores for matched US allopathic seniors in the 2018 National Resident Matching Program were used as a measure of clinical specialties' competitiveness of admissions. We calculated a composite measure of NPV and annual work-hours by dividing each specialty's NPV by the reported average number of hours worked per year. Results In our analysis, orthopedic surgery had the highest NPV ($10,308,868), whereas family medicine had the lowest NPV ($5,274,546). Dermatology and plastic surgery had the highest mean USMLE Step 1 scores (249 for both), whereas family medicine had the lowest (220). Clinical specialties' NPVs were positively associated with mean USMLE Step 1 scores (Pearson's r = 0.82; p < 0.001). Conclusions In this study, we describe associations suggesting that medical students respond to financial incentives in choosing clinical specialties and that these decisions are mediated by USMLE Step 1 scores. This underscores the importance of titrating and aligning incentives to improve the allocation of medical students into clinical specialties.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...