بهبود تولید بیودیزل با کمک اولتراسونیک حاصل از ضایعات صنعت گوشت (چربی خوک) با استفاده از نانوکاتالیزور اکسید مس سبز: مقایسه سطح پاسخ و مدل سازی شبکه عصبی
سال انتشار: 2021 - تعداد صفحات فایل pdf انگلیسی: 11 - تعداد صفحات فایل doc فارسی: 25
سوخت زیستی سبز ، تمیز و پایدار تنها گزینه به منظور کاهش کابرد سوخت های فسیلی ، پاسخگویی به تقاضای زیاد انرژی و کاهش آلودگی هوا است. تولید بیودیزل زمانی ارزان می شود که از یک پیش ماده ارزان ، کاتالیزور سازگار با محیط زیست و فرآیند مناسب استفاده کنیم. پیه خوک از صنعت گوشت حاوی اسید چرب بالا است و به عنوان یک پیش ماده موثر برای تهیه بیودیزل کاربرد دارد. این مطالعه بیودیزل را از روغن پیه خوک از طریق فرآیند استری سازی دو مرحله ای با کمک اولتراسونیک و کاتالیزور تولید می کند. عصاره Cinnamomum tamala (C. tamala) برای تهیه نانوذرات CuO مورد استفاده قرار گرفت و با استفاده از طیف مادون قرمز ، پراش اشعه ایکس ، توزیع اندازه ذرات ، میکروسکوپ الکترونی روبشی و انتقال مشخص شد. تولید بیودیزل با استفاده از طرح Box-Behnken (BBD) و شبکه عصبی مصنوعی (ANN) ، در محدوده متغیرهای زمان اولتراسونیک (us )(20-40 min)، بارگیری نانوکاتالیزور 1-3) CuO درصد وزنی( ، و متانول به قبل از نسبت مولی PTO (10:1e30:1) مدلسازی شد. آنالیز آماری ثابت کرد که مدل سازی شبکه عصبی بهتر از BBD است. عملکرد بهینه 97.82٪ با استفاده از الگوریتم ژنتیک (GA) در زمان US: 35.36 دقیقه ، بار کاتالیزور CuO: 2.07 درصد وزنی و نسبت مولی: 29.87: 1 به دست آمد. مقایسه با مطالعات قبلی ثابت کرد که اولتراسونیک به میزان قابل توجهی موجب کاهش بار نانوکاتالیزور CuO می شود ، و نسبت مولی را افزایش می دهد و این فرایند را بهبود می بخشد.
کلمات کلیدی: چربی خوک | التراسونیک | اکسید مس | سنتز سبز | شبکه عصبی | سطح پاسخ
|مقاله ترجمه شده|
Performance assessment of coupled green-grey-blue systems for Sponge City construction
ارزیابی عملکرد سیستم های سبز و خاکستری-آبی همراه برای ساخت و ساز شهر اسفنجی-2020
In recent years, Sponge City has gained significant interests as a way of urban water management. The kernel of Sponge City is to develop a coupled green-grey-blue system which consists of green infrastructure at the source, grey infrastructure (i.e. drainage system) at the midway and receiving water bodies as the blue part at the terminal. However, the current approaches for assessing the performance of Sponge City construction are confined to green-grey systems and do not adequately reflect the effectiveness in runoff reduction and the impacts on receiving water bodies. This paper proposes an integrated assessment framework of coupled green-grey-blue systems on compliance of water quantity and quality control targets in Sponge City construction. Rainfall runoff and river system models are coupled to provide quantitative simulation evaluations of a number of indicators of landbased and river quality. A multi-criteria decision-making method, i.e., Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is adopted to rank design alternatives and identify the optimal alternative for Sponge City construction. The effectiveness of this framework is demonstrated in a typical plain river network area of Suzhou, China. The results demonstrate that the performance of Sponge City strategies increases with large scale deployment under smaller rainfall events. In addition, though surface runoff has a dilution effect on the river water quality, the control of surface pollutants can play a significant role in the river water quality improvement. This framework can be applied to Sponge City projects to achieve the enhancement of urban water management.
Keywords: Low impact development | Sponge City | Green-grey-blue system | Performance assessment | TOPSIS
Influencing factors on energy management in industries
تأثیر عوامل مؤثر بر مدیریت انرژی در صنایع-2020
Energy management has been considered in the global agenda as a way to improve energy performance and greenhouse gas reduction in organizations. Industries account for a significant part of energy use worldwide and present opportunities for energy efficiency improvements. Within the industry, energy management is a complex task, regarding scenarios with variables related to the following perspectives: economics, contingency, technological change and behavioural. This paper aims at analyzing the influencing factors on energy management in industries from these perspectives. A survey with 40 variables was carried out with middle managers from different industrial sectors in Brazil. The variables were divided into three groups: drivers for investments in energy efficiency; organizational processes and actions in energy management; involvement of middle managers. Initially, an exploratory factor analysis technique was employed aiming at specifying the main factors influencing energy management. In the sequence, a confirmatory factor analysis was used to associate the variables to the main factors as well as to know how the factors relate to each other. The study showed a positive correlation among all the factors identified. Statistical tests suggested that the factors could not be explained separately. Hypotheses tests were applied to verify the influence of the factors among the groups surveyed. The final model comprised eight factors into the three groups: organizational (strategic, operational), involvement (motivation, support), drivers (production, economics, competitiveness, environment). The results and the main implications of the study are discussed in the paper.
Keywords: Energy management | ISO 50001 | Energy efficiency | Industries | Factor analysis
Diaspora entrepreneurs’ push and pull institutional factors for investing in Africa : Insights from African returnees from the United Kingdom
فشار و جذب عوامل نهادی کارآفرینان دیاسپورا برای سرمایه گذاری در آفریقا: بینش بازگشت کنندگان آفریقایی از انگلستان-2020
Applying the institution-based views, this article conceptualises how diaspora entrepreneurs take stimuli from the push and pull institutional factors to develop business enterprises in their countries of origin. Using cases of African diaspora entrepreneurs in the UK and the grounded theory methodological approach, our conceptualised model demonstrates that the diasporas use the new knowledge, skills and wealth they have gained in the UK in tandem with support from trusted family, kinship and business ties at home to develop enterprises. It further demonstrates that diaspora entrepreneurs foster resilience to withstand weak formal institutions in their countries of origin and the discriminatory obstacles in the UK. We also found that institutional barriers which served as push factors that encouraged or forced migrants to leave their home countries to seek greener pastures abroad may later become pull factors that enable them to engage in diaspora entrepreneurship which is often characterised by paradoxes. Particularly, the informal institutions that constrain foreign investors can become assets for African diaspora entrepreneurs and help them set up new businesses and exploit market opportunities in Africa. The implications of the study for diaspora entrepreneurship literature are outlined.
Keywords: Africa | Institutional challenges | Policy | Diaspora entrepreneurs | Entrepreneurship | Institutions
Phase-based externality analysis for large hydropower projects
تجزیه و تحلیل بیرونی مبتنی بر فاز برای پروژه های بزرگ نیروگاهی-2020
The global pressure of reducing greenhouse gas emission with an increasing energy demand has promoted the development of hydropower projects. However, these projects are always involved with controversial issues even when providing great positive externalities. This calls for more comprehensively quantitative analysis of hydropower project externalities. This paper establishes an analysis framework for hydropower project externalities based on the Life Cycle Assessment methodology and the economic valuation of hydropower externalities, and then applies the framework to the assessment of the Three Gorges Project and the Xiluodu Project as cases. The results indicate that: (1) hydropower project externalities are multi-component and dynamic in different phases of project life cycle; (2) the construction of large hydropower projects is beneficial for social welfare promotion, but the enhancement doesnt appear immediately at the startup but with a lag; and (3) along the life cycle of a hydropower project, negative externalities are prominent in the early phases while positive ones account for a major proportion in the late phases, calling for special attention to risk management during the construction and benefit allocation management during project operation. The results and recommendations of this paper can also be applied to other types of public or private projects for better social performance.
Keywords: Externality | Life cycle assessment | Stakeholders | Hydropower project | The Three Gorges project | The Xiluodu project
Goal heterogeneity at start-up_ are greener start-ups more innovative?
ناهمگنی هدف در شروع کار: آیا استارت آپ های سبزتر نوآورتر هستند؟-2020
Start-ups differ in the extent to which they introduce innovations to markets and, hence, in their potential contribution to society. Understanding the heterogeneous character of start-ups is key to explaining the varia- bility in innovation. In this study, we explore whether start-ups that place more emphasis on environmental value creation versus economic value creation (‘greener start-ups’) are more innovative. We also examine how environmental regulations at the country level affect this relationship. We theorize that the fundamental dif- ference between economic value creation (private wealth generation, i.e., self-regarding interest) and en- vironmental value creation (environmental gains for society, i.e., other-regarding interest) influences en- trepreneurial opportunity identification and exploitation. When considering the regulatory context, we draw on the innovation inducement effect of environmental regulations and expect these regulations to be most effective for entrepreneurs with a strong emphasis on economic value creation. Performing multi-level ordered logit regressions with 2,945 start-up entrepreneurs in 31 countries (Global Entrepreneurship Monitor data), we find that ‘greener start-ups’ are more likely to engage in product and process innovations. We find some evidence of a positive moderation effect for environmental regulations. We advance research on innovative entrepreneurship by theorizing and finding evidence that other-regarding goals are relevant in explaining start-up innovativeness.
Keywords: Goal heterogeneity | Start-ups | Green entrepreneurship | Environmental regulations | Innovation | Global Entrepreneurship | Monitor
Nonlinear contact force law for spherical indentation of FGM coated elastic substrate: An extension of Hertz’s solution
قانون نیروی غیر تماس غیر خطی برای تورفتگی کروی بستر الاستیک روکش شده با FGM: گسترش راه حل هرتز-2020
This paper develops a nonlinear contact force law for the indentation of an elastic substrate with thin functionally graded material (FGM) coating by a rigid smooth sphere. The nonlinear contact force law is explicitly expressed in form of extended Hertz’s solution with a correction factor, which is related to the coating thickness, radius of the indenter, contact interference and the modulus ratio. The explicit expres- sion of the correction factor for arbitrary coating modulus gradation can be determined statistically with extensive numerical results. For computational efficiency and accuracy, an analytical contact model based on multilayered half space is developed and the associated mixed boundary value problem is converted to a Fredholm integral equation of the second kind. This model discretizes the thin FGM coating into n dissimilar and fully bonded sub-layers. Each sub-layer is a homogeneous elastic seam of finite thick- ness and constant elastic modulus and Poisson’s ratio. Variation of the coating elastic properties along the thickness direction is accurately approximated by the multilayered system. The non-linear contact force laws in closed-form are specifically given for both linear and exponential modulus gradations. The load-displacement relations predicted by these force laws are shown to be in exact agreement with the numerical results from the Fredholm integral equation. Additionally, this nonlinear contact force law for FGM coating is further incorporated into the Greenwood and Williamson model, which provides a feasible and effective way for modeling the contact of FGM coated rough surfaces.
Keywords: Contact force law | Coated materials | Functionally graded material (FGM) | Rough surface | Spherical indentation
The role of environmental entrepreneurship for sustainable development: Evidence from 35 countries in Sub-Saharan Africa
نقش کارآفرینی زیست محیطی برای توسعه پایدار: شواهدی از 35 کشور در جنوب صحرای آفریقا-2020
This research seeks to confirm the achievement of sustainable development in Sub-Sahara Africa. In view of this, a panel of 35 Sub-Saharan Africa countries divided into two sub-panels based on their income groupings, namely lowincome, and middle-income countries, from 2000 to 2014 with a cross-sectional dependence among the series was used as a prerequisite for the analysis. We used the Pooled Mean Group estimators of the Autoregressive Distributed Lag model to ascertain the long-run mechanism between variables and analyse the Environmental Kuznets Curve hypothesis. The key results are: (1) income per capita significantly increases environmental pollution where environmental entrepreneurship decreases pollution of the environment across all panels of SSA countries; (2) in the low-income SSA economies, trade openness enhance environmental quality but increase environmental pollution in both the aggregated panel and middle-income SSA nations; (3) with the exception of low-income countries, human development palpably decreases environmental pollution in middle-income countries and in the aggregated panel a reduction is observed; (4) from financial development perspective, it produces positive and significant effect in the aggregated panel of SSA countries and middle-income SSA nations; (5) the environmental Kuznets curve conjuncture is supported for the selected panels in SSA region. Consequently, governments and policymakers should reinforce policies for the reduction of environmental pollution, more importantly, green financing policies, encourage aspiring environmental entrepreneurs to set environmentally-driven businesses, promote the use of environmental products to mitigate environmental problems and achieve sustainable development.
Keywords: Environmental entrepreneurship | Sustainable development | Environmental pollution | Environmental Kuznets curve | Sub-Saharan Africa
Economic feasibility valuing of deep mineral resources based on risk analysis: Songtao manganese ore - China case study
ارزیابی امکان سنجی اقتصادی منابع معدنی عمیق بر اساس ریسک تجزیه و تحلیل: سنگ معدن منگنز Songtao - مطالعه موردی چین-2020
The exploitation of deep mineral resources is an inevitable choice under economic development and resource shortage. Assessing the economic feasibility of deep mineral resource exploit projects is a prerequisite for resource industry development. Mining industry have some problems influence its economic feasibility, including long mining period, high infrastructure investment and lack flexibility, and have risks of geology instability and economic reserve degrade. On the other hand, with the increase of the buried depth of mineral resources, some problems have intensified the uncertainty of the profit of deep resource utilization project, such as high stress, high lithology, high temperature environment, and increase of upgrading cost. Net Present Value (NPV) and Internal Rate of Return (IRR) are traditional economic evaluation means which difficult to identify and assess risks precisely. Decoupled Net Present Value (DNPV) provides an efficiency tool to separate the time value and risk cost which is helpful to finds the real value of projects. A manganese mining project which is located Guizhou province, China is analyzed, paper choices several mainly risks of influence expected revenue to analysis project feasibility based on the DNPV technology, which includes the thickness of ore body, ore grade, market price, operation cost and nature disaster. The cost of potential environmental risk (carbon emission cost) also is analyzed. Paper constructs a risk management framework by risk identify, assess and classification, and analyzes the corresponding measures to reduce risk costs. The mainly risk cost of study case from market price shock and unexpected ore grade decline, which accounting for 80% of the total risk cost. In the process of deep mineral resources exploit, effective cost control measures can reduce the risk cost to a certain extent, including improving productivity, reducing unit cost of ore, improving mine sustainability and exploration accuracy. Green mineral construction is a feasible direction of deep resource utilization. For improve the accuracy of economic feasibility evaluation of deep mineral resources utilization, further improvement is needed in the selection and construction of different risk assessment model.
Keywords: Deep mining | Risk value assess | DNPV | Risk management | Songtao manganese
Nudging and citizen science: The effectiveness of feedback in energy-demand management
برهنگی و علم شهروندی: اثربخشی بازخورد در مدیریت تقاضای انرژی-2020
Nudging is a framework for directing individuals toward better behavior, both for personal and societal benefits, through heuristics that drive the decision-making process but without preventing any available choice. Considering the Grand Challenges that our society faces today, nudging represents an effective framework to tackle some of these pressing issues. In this work, we assessed the effectiveness of informational nudges in the form of detailed, customized feedback, within an energy-demand-management project. The project aligns energy production and demand, thereby reducing greenhouse gases and pollutant emissions to mitigate climate change. We also offered evidence that this kind of feedback is efficacious in involving individuals as citizen scientists, who volunteer their efforts toward the success of the environmentally-related aim of the project. The results of this research – based on surveys, electroencephalography measurements and online participation measures – indicate that feedback can be an effective tool to steer participants’ behavior under the libertarian paternalistic view of nudging, increase their motivation to contribute to citizen science, and improve their awareness about environmentally-related issues. In so doing, we provide evidence that nudging and citizen science can be jointly adopted toward the mitigation of pressing environmental issues.
Keywords: Nudging | Citizen science | Crowd | Energy-demand management | Grand challenges | Electroencephalography