scholarly journals EFFECT OF PRODUCTION PARAMETERS ON THE ECONOMIC FEASIBILITY OF A BIOFUEL ENTERPRISE

2017 ◽  
Vol 49 (3) ◽  
pp. 347-362
Author(s):  
SAMUEL D. ZAPATA ◽  
LUIS A. RIBERA ◽  
MARCO A. PALMA
Keyword(s):  
Likelihood Estimation ◽  
Growing Season ◽  
Economic Feasibility ◽  
Biofuel Production ◽  
Financial Model ◽  
Production Parameters ◽  
Simulation Techniques ◽  
Biofuel Industry ◽  
Feedstock Production ◽  
The Impact

AbstractIn order to guarantee the success of the nascent cellulose-based biofuel industry, it is crucial to identify the most economically relevant components of the biofuel production path. To this aim, an original stochastic financial model is developed to estimate the impact that different feedstock production and biofuel conversion parameters have on the probability of economic success. Estimation of the model was carried out using Monte Carlo simulation techniques along with parametric maximum likelihood estimation procedures. Results indicate that operational efficiency strategies should concentrate on improving feedstock yields and extending the feedstock growing season.

scholarly journals Improving ‘Lipid Productivity’ in Microalgae by Bilateral Enhancement of Biomass and Lipid Contents: A Review

2020 ◽  
Vol 12 (21) ◽  
pp. 9083
Author(s):  
Zahra Shokravi ◽  
Hoofar Shokravi ◽  
Ong Hwai Chyuan ◽  
Woei Jye Lau ◽  
Seyed Saeid Rahimian Koloor ◽  
...  
Keyword(s):  
Growth Rate ◽  
Lipid Production ◽  
Integrated Approach ◽  
Economic Feasibility ◽  
Lipid Productivity ◽  
Biofuel Production ◽  
Strain Selection ◽  
Microalgal Biomass ◽  
Lipid Contents ◽  
Feedstock Production

Microalgae have received widespread interest owing to their potential in biofuel production. However, economical microalgal biomass production is conditioned by enhancing the lipid accumulation without decreasing growth rate or by increasing both simultaneously. While extensive investigation has been performed on promoting the economic feasibility of microalgal-based biofuel production that aims to increase the productivity of microalgae species, only a handful of them deal with increasing lipid productivity (based on lipid contents and growth rate) in the feedstock production process. The purpose of this review is to provide an overview of the recent advances and novel approaches in promoting lipid productivity (depends on biomass and lipid contents) in feedstock production from strain selection to after-harvesting stages. The current study comprises two parts. In the first part, bilateral improving biomass/lipid production will be investigated in upstream measures, including strain selection, genetic engineering, and cultivation stages. In the second part, the enhancement of lipid productivity will be discussed in the downstream measure included in the harvesting and after-harvesting stages. An integrated approach involving the strategies for increasing lipid productivity in up- and down-stream measures can be a breakthrough approach that would promote the commercialization of market-driven microalgae-derived biofuel production.

AN ECONOMIC STUDY FOR THE IMPACT OF BIOFUEL PRODUCTION EXPANSION

2018 ◽  
Vol 3 (2) ◽  
pp. 259-260
Author(s):  
I. S. Ali ◽  
A. M. Taryal ◽  
S. A. Abou-El Naga ◽  
M. M. Abd-El Menem
Keyword(s):  
Biofuel Production ◽  
Economic Study ◽  
The Impact

scholarly journals Assessment of Spatiotemporal Peak Shift of Intra-Urban Transportation Taking a Case in Bangkok, Thailand

2021 ◽  
Vol 13 (12) ◽  
pp. 6777
Author(s):  
Masanobu Kii ◽  
Yuki Goda ◽  
Varameth Vichiensan ◽  
Hiroyuki Miyazaki ◽  
Rolf Moeckel
Keyword(s):  
Developing Countries ◽  
Travel Time ◽  
Demand Management ◽  
Likelihood Estimation ◽  
Road Transport ◽  
Peak Shift ◽  
Time Shift ◽  
Peak Time ◽  
Management Scenarios ◽  
The Impact

Reducing congestion has been one of the critical targets of transportation policies, particularly in cities in developing countries suffering severe and chronic traffic congestions. Several traditional measures have been in place but seem not very successful. This paper applies the agent-based transportation model MATSim for a transportation analysis in Bangkok to assess the impact of spatiotemporal transportation demand management measures. We collect required data for the simulation from various data sources and apply maximum likelihood estimation with the limited data available. We investigate two demand management scenarios, peak time shift, and decentralization. As a result, we found that these spatiotemporal peak shift measures are effective for road transport to alleviate congestion and reduce travel time. However, the effect of those measures on public transport is not uniform but depends on the users’ circumstances. On average, the simulated results indicate that those measures increase the average travel time and distance. These results suggest that demand management policies require considerations of more detailed conditions to improve usability. The study also confirms that microsimulation can be a tool for transport demand management assessment in developing countries.

scholarly journals Modeling Energy Communities with Collective Photovoltaic Self-Consumption: Synergies between a Small City and a Winery in Portugal

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 323
Author(s):  
Guilherme Pontes Luz ◽  
Rodrigo Amaro e Silva
Keyword(s):  
Economic Feasibility ◽  
Small City ◽  
Total System ◽  
Trade Offs ◽  
Southern Portugal ◽  
Energy Community ◽  
Individual Self ◽  
The Impact ◽  
The City ◽  
Modest Reduction

The recently approved regulation on Energy Communities in Europe is paving the way for new collective forms of energy consumption and production, mainly based on photovoltaics. However, energy modeling approaches that can adequately evaluate the impact of these new regulations on energy community configurations are still lacking, particularly with regards to the grid tariffs imposed on collective systems. Thus, the present work models three different energy community configurations sustained on collective photovoltaics self-consumption for a small city in southern Portugal. This energy community, which integrates the city consumers and a local winery, was modeled using the Python-based Calliope framework. Using real electricity demand data from power transformers and an actual winery, the techno-economic feasibility of each configuration was assessed. Results show that all collective arrangements can promote a higher penetration of photovoltaic capacity (up to 23%) and a modest reduction in the overall cost of electricity (up to 8%). However, there are clear trade-offs between the different pathways: more centralized configurations have 53% lower installation costs but are more sensitive to grid use costs (which can represent up to 74% of the total system costs). Moreover, key actor’s individual self-consumption rate may decrease by 10% in order to benefit the energy community as a whole.

Institutional Quality and Trade Flow: Empirical Evidence from Malaysia and Other OIC Member Countries in Africa

2021 ◽  
pp. 097508782098717
Author(s):  
Hammed Agboola Yusuf ◽  
Luqman Olanrewaju Afolabi ◽  
Waliu Olawale Shittu ◽  
Kafilah Lola Gold ◽  
Murtala Muhammad
Keyword(s):  
Economic Growth ◽  
Bilateral Trade ◽  
Trade Flow ◽  
Estimation Method ◽  
Institutional Quality ◽  
Likelihood Estimation ◽  
Political Stability ◽  
Bilateral Trade Flow ◽  
World Governance Indicators ◽  
The Impact

This article examines the impact of institutional quality on bilateral trade flow between Malaysia and selected 25 African Organisation of Islamic Cooperation (OIC) member countries. Four institutional qualities were selected from World Governance Indicators with other trade predictors from the period from 1985 to 2016. Using gravity model of trade and Poisson pseudo-maximum likelihood estimation method (PPML) technique, the results confirm that government effectiveness, regulatory quality and political stability have an adverse effect on bilateral trade flow among the OIC countries in Africa. On the other hand, these institutional quality variables were considered as a strength for Malaysian economic growth. Therefore, better institutional quality reforms are needed among OIC member countries in Africa in order to accelerate trade, economic growth and development in their region.

scholarly journals The Impact of Climate Change on the Sugar Content of Grapes and the Sustainability of their Production in the Czech Republic

2020 ◽  
Vol 13 (1) ◽  
pp. 222
Author(s):  
Miroslava Navrátilová ◽  
Markéta Beranová ◽  
Lucie Severová ◽  
Karel Šrédl ◽  
Roman Svoboda ◽  
...  
Keyword(s):  
Climate Change ◽  
Czech Republic ◽  
Sugar Content ◽  
Growing Season ◽  
Vegetation Period ◽  
The Czech Republic ◽  
Impact Of Climate Change ◽  
Secondary Sources ◽  
The Impact ◽  
Growing Region

The aim of the presented article is to evaluate the impact of climate change on the sugar content of grapes in the Czech Republic during the period 2000–2019 through selected indicators on the basis of available secondary sources. Attention is focused on the developments in both the main wine-growing regions of Moravia and Bohemia. In the field of viticulture and wine-growing, the sugar content of grapes, as a basic parameter for the classification of wines, plays an important role. In the Czech Republic, the average sugar content of grapes has had a constantly growing trend. This trend is evident both in the wine-growing region of Bohemia and in the wine-growing region of Moravia. The impact of climate change, especially the gradual increase of average temperatures in the growing season, cannot be overlooked. It greatly affects, among other things, the sugar content of grapes. Calculations according to the Huglin Index and the Winkler Index were used to determine the relationship between climate and sugar content. These indexes summarize the course of temperatures during the entire vegetation period into a single numerical value. The results show that both indexes describe the effect of air temperature on sugar content in both wine regions of the Czech Republic in a statistically significant way. The Huglin Index shows a higher correlation rate. The Winkler Index proved to be less suitable for both areas. Alternatively, the Winkler Index calculated for a shorter growing season was tested, which showed a higher degree of correlation with sugar content, approaching the significance of the Huglin Index.

scholarly journals Resources, Production Scales and Time Required for Producing RNA Vaccines for the Global Pandemic Demand

Vaccines ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
Zoltán Kis ◽  
Cleo Kontoravdi ◽  
Robin Shattock ◽  
Nilay Shah
Keyword(s):  
Production Process ◽  
Messenger Rna ◽  
Vaccination Campaign ◽  
Vaccine Dose ◽  
Economic Feasibility ◽  
Small Scale ◽  
Production Scale ◽  
Working Volume ◽  
Global Demand ◽  
The Impact

To overcome pandemics, such as COVID-19, vaccines are urgently needed at very high volumes. Here we assess the techno-economic feasibility of producing RNA vaccines for the demand associated with a global vaccination campaign. Production process performance is assessed for three messenger RNA (mRNA) and one self-amplifying RNA (saRNA) vaccines, all currently under clinical development, as well as for a hypothetical next-generation saRNA vaccine. The impact of key process design and operation uncertainties on the performance of the production process was assessed. The RNA vaccine drug substance (DS) production rates, volumes and costs are mostly impacted by the RNA amount per vaccine dose and to a lesser extent by the scale and titre in the production process. The resources, production scale and speed required to meet global demand vary substantially in function of the RNA amount per dose. For lower dose saRNA vaccines, global demand can be met using a production process at a scale of below 10 L bioreactor working volume. Consequently, these small-scale processes require a low amount of resources to set up and operate. RNA DS production can be faster than fill-to-finish into multidose vials; hence the latter may constitute a bottleneck.

Fuelling rural development? The impact of biofuel feedstock production in southern Africa on household income and expenditures

2021 ◽  
Vol 76 ◽  
pp. 102053
Author(s):  
S. Mudombi ◽  
C. Ochieng ◽  
F.X. Johnson ◽  
G. von Maltitz ◽  
D. Luhanga ◽  
...  
Keyword(s):  
Rural Development ◽  
Southern Africa ◽  
Household Income ◽  
Biofuel Feedstock ◽  
Feedstock Production ◽  
The Impact

scholarly journals Facilitation Effects of Haloxylon salicornicum Shrubs on Associated Understory Annuals, and a Modified “Stress-Gradient” Hypothesis for Droughty Times

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1726
Author(s):  
Nasr H. Gomaa ◽  
Ahmad K. Hegazy ◽  
Arafat Abdel Hamed Abdel Latef
Keyword(s):  
Species Richness ◽  
Water Availability ◽  
Stress Gradient ◽  
Growing Season ◽  
Annual Species ◽  
Negative Effects ◽  
Growing Seasons ◽  
Dry Seasons ◽  
The Impact ◽  
Haloxylon Salicornicum

Perennial shrub-annual plant interactions play key roles in desert regions influencing the structure and dynamics of plant communities there. In the present study, carried out in northwestern Saudi Arabia, we examined the effect of Haloxylon salicornicum shrubs on their associated understory annual species across four consecutive growing seasons, along with a record of the seasonal rainfall patterns. We measured density and species richness of all the annual species in permanent quadrats located beneath individual shrubs, as well as in the spaces between shrubs. During wet growing season H. salicornicum shrubs significantly enhanced the density and species richness of sub-canopy species, whereas in the relatively dry seasons they exerted negative effects on the associated species. In all growing seasons, the presence of shrubs was associated with enhanced soil properties, including increased organic carbon content, silt + clay, and levels of nutrients (N, P and K). Shrubs improved soil moisture content beneath their canopies in the wet growing season, while in the dry seasons they had negative effects on water availability. Differences in effects of H. salicornicum on understory plants between growing seasons seem due to the temporal changes in the impact of shrubs on water availability. Our results suggest the facilitative effects of shrubs on sub-canopy annuals in arid ecosystems may switch to negative effects with increasing drought stress. We discuss the study in light of recent refinements of the well-known “stress-gradient hypothesis”.

scholarly journals Maximum Likelihood Estimation of the VAR(1) Model Parameters with Missing Observations

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Helena Mouriño ◽  
Maria Isabel Barão
Keyword(s):  
Stochastic Process ◽  
Missing Data ◽  
Maximum Likelihood ◽  
Moving Average ◽  
Practical Importance ◽  
Likelihood Estimation ◽  
Model Parameters ◽  
Missing Observations ◽  
Data Set ◽  
The Impact

Missing-data problems are extremely common in practice. To achieve reliable inferential results, we need to take into account this feature of the data. Suppose that the univariate data set under analysis has missing observations. This paper examines the impact of selecting an auxiliary complete data set—whose underlying stochastic process is to some extent interdependent with the former—to improve the efficiency of the estimators for the relevant parameters of the model. The Vector AutoRegressive (VAR) Model has revealed to be an extremely useful tool in capturing the dynamics of bivariate time series. We propose maximum likelihood estimators for the parameters of the VAR(1) Model based on monotone missing data pattern. Estimators’ precision is also derived. Afterwards, we compare the bivariate modelling scheme with its univariate counterpart. More precisely, the univariate data set with missing observations will be modelled by an AutoRegressive Moving Average (ARMA(2,1)) Model. We will also analyse the behaviour of the AutoRegressive Model of order one, AR(1), due to its practical importance. We focus on the mean value of the main stochastic process. By simulation studies, we conclude that the estimator based on the VAR(1) Model is preferable to those derived from the univariate context.

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