Cybersecurity and dynamic operation in practice: Equipment impacts and safety guarantees

Though dynamic operation of chemical processes has been extensively explored theoretically in contexts such as economic model predictive control or even considering the potential for cyberattacks on control systems creating non-standard operating policies, important practical questions remain regarding dynamic operation. In this work, we look at two of these with particular relevance to process safety: (1) evaluating dynamic operating policies with respect to process equipment fidelity and (2) evaluating procedures for determining the parameters of an advanced control law that can promote both dynamic operation as well as safety if appropriately designed. Regarding the first topic, we utilize computational fluid dynamics and finite element analysis simulations to analyze how cyberattacks on control systems could impact a metric for stress in equipment (maximum Von Mises stress) over time. Subsequently, we develop reduced-order models showing how both a process variable and maximum Von Mises stress vary over time in response to temperature variations at the boundary of the equipment, to use in evaluating how advanced control frameworks might impact and consider the stress. We close by investigating options for obtaining parameters of an economic model predictive control design that would need to meet a variety of theoretical requirements for safety guarantees to hold. This provides insights on practical safety aspects of control theory, and also indicates relationships between control and design from a safety perspective that highlight further relationships between design and control under dynamic operation to deepen perspectives from the computational fluid dynamics and finite element analysis discussions.     

Assessing the economic impact of invasive species: the case of yellow starthistle (Centaurea solsitialis L.) in the rangelands of Idaho, USA

Yellow starthistle (Centaurea solsitialis L.) is an invasive weed that creates problems for the management of Idaho's rangelands. A bioeconomic approach combined with an input-output economic model is used to estimate direct and secondary economic costs of the weed in relation to its interference with agricultural and non-agricultural benefits that rangelands provide. Direct economic costs of the infestations were estimated to be of 8.2 million '05 dollars per year, and secondary costs of 4.5 million '05 dollars per year, for a total of 12.7 million '05 dollars; agricultural related economic impacts accounted for 79% of this total cost, and non-agricultural for 21%.     

Is Municipal Solid Waste Recycling Economically Efficient?

It has traditionally been argued that recycling municipal solid waste (MSW) is usually not economically viable and that only when externalities, long-term dynamic considerations, and/or the entire product life cycle are taken into account, recycling becomes worthwhile from a social point of view. This article explores the results of a wide study conducted in Israel in the years 2000–2004. Our results reveal that recycling is optimal more often than usually claimed, even when externality considerations are ignored. The study is unique in the tools it uses to explore the efficiency of recycling: a computer-based simulation applied to an extensive database. We developed a simulation for assessing the costs of handling and treating MSW under different waste-management systems and used this simulation to explore possible cost reductions obtained by designating some of the waste (otherwise sent to landfill) to recycling. We ran the simulation on data from 79 municipalities in Israel that produce over 60% of MSW in Israel. For each municipality, we were able to arrive at an optimal method of waste management and compare the costs associated with 100% landfilling to the costs born by the municipality when some of the waste is recycled. Our results indicate that for 51% of the municipalities, it would be efficient to adopt recycling, even without accounting for externality costs. We found that by adopting recycling, municipalities would be able to reduce direct costs by an average of 11%. Through interviews conducted with representatives of municipalities, we were also able to identify obstacles to the utilization of recycling, answering in part the question of why actual recycling levels in Israel are lower than our model predicts they should be.     

数字经济、人才流动与长三角地区高质量发展

数字经济技术在产业转型和经济高质量发展中扮演着越来越重要的角色。基于2011—2018年长三角“三省一市”共41个城市数据,测度了长三角地区数字经济和高质量发展的综合水平,分析数字经济对长三角地区高质量发展的影响,创新性地构造了人才流动不平衡指标,并探讨区域内人才流动不平衡对二者关系的调节效应。研究发现：长三角地区高质量发展水平和数字经济规模逐年上升。数字经济发展通过提升生产效率、流通效率和社会便利促进长三角地区高质量发展,非核心区域的正影响强度大于核心区域。人才流动不平衡会逆向调节数字经济对长三角地区高质量发展的正影响程度,但这一调节效应存在区域异质性。此外数字经济对长三角地区高质量发展存在经济距离为权重矩阵的空间负向溢出效应。     

不同施肥措施下长江经济带地区农田土壤有机碳含量的变化分析

收集整理1992年1月至2022年5月长江经济带地区长期定位施肥试验文献,提取并整合了其中农田土壤有机碳的资料.采用归一化处理和变化速率的分析方法,研究长期不同施肥措施下长江经济带地区农田土壤有机碳含量的总体变化,并比较3种耕作模式及不同土壤类型下土壤有机碳含量的变化差异,判断分析试验持续年限长短对土壤有机碳动态的影响.结果表明,在长期不同施肥措施下,我国长江经济带地区农田土壤有机碳含量整体呈上升趋势,无机氮肥磷肥配施(NP)、无机氮磷钾肥配施(NPK)、单独施用有机肥(O)和有机无机肥配施(NPKO)处理均能增加农田土壤的有机碳含量,其中以NPKO处理为最大,而单独施用无机氮肥(N)则会降低土壤有机碳含量.旱田、水田和水旱轮作农田土壤有机碳含量变化速率分别为0.22、 0.24和0.16g·(kg·a)^-1,3种耕作模式在土壤固碳效果方面并无显著性差异.O和NPKO处理下所带来的有机碳相对快速增加效应在旱田土壤中的持续年限最高不超过28 a,而在水田及水旱轮作土壤中依然可以持续到28 a以上.在不同的土壤类型下,土壤有机碳含量的变化速率存在着一定的差异,平均有机...     

水库溃坝损失及其计算方法研究

主要研究水库渍坝损失及其计算方法．分析了水库溃坝及其损失的特点，提出了溃坝洪水淹没损失的直接经济损失的实物型损失与收益型损失、间接经济损失、非经济损失的内容及其计算方法，并探讨了库区坍岸损失与清决工程损失计算方法．     

The idea of sustainable development

In this lecture, I demonstrate how very different macroeconomic history begins to look if Nature is included as a capital asset in production activities. The tentative conclusions I draw from the evidence are: (1) high population growth in the world’s poorest regions (South Asia and sub-Saharan Africa) has been an obstacle to the achievement of sustainable economic development there; relatedly, (2) when population growth is taken into account, the accumulation of manufactured capital, knowledge, and human capital (health and education) has not compensated for the degradation of natural capital in South Asia and sub-Saharan Africa and, in all probability, even in the UK and the US; (3) China is possibly an exception to (1) and (2). This article is based on the Keynote Lecture delivered at the international symposium on “Sustainability in an Unequal World”, held in Tokyo on November 24, 2006. The exposition relies on my book, Economics: A Very Short Introduction, Oxford University Press, Oxford, 2007. The author is the Frank Ramsey Professor of Economics at the University of Cambridge and a Fellow of St. John’s College, Cambridge.     

关于企业环境保护审计的初探

从环保审计的现状入手，分析目前企业环保审计难以向纵深发展的主要原因，提出实施企业环保审计的最佳切入点，将环保审计融入常规审计之中，并对环保审计提出配套的措施，确保环保审计适应现代化企业的发展。     

Sustainable cities: do political factors determine the quality of life?

The implementation of urban sustainability practices is affected by political obstacles, and diverse political ideologies may defend different city models. Sustainable policy design could also be affected by several factors that cause the deflection of resources initially allocated to other groups that are contrary to the concerns pursued and have the power to veto sustainable plans by exerting pressure on the party in power.In this sense, the aim of this paper is to show the impact that political factors have on cities’ sustainability, and the effect of both on cities’ economic development. To do so, we used the 78 Spanish cities with a population over 100,000 studied by MERCO (Spanish Corporate Reputation Monitor) as regards their levels of sustainability for the fiscal years 2008 and 2009. Both relationships have been tested empirically through two dependence models using linear regression techniques.The results obtained show that political competition improves cities’ sustainability, while a leftist ideology has an inverse impact. On the other hand, a significant direct relationship has been observed between urban sustainability and municipal economic activity.     

Holocene fire history from the Greater Blue Mountains World Heritage Area, New South Wales, Australia: the climate, humans and fire nexus

This study presents a reconstruction of the fire activity of the last ~14,200 cal. years BP (before AD 1950) from Gooches Crater Right, located on the Newnes Plateau, approximately 150 km to the west of Sydney (~33°27′S, 150°16′E) within the Blue Mountains National Park. Charcoal analysis and palynology were undertaken with the aim of untangling any inter-relationship between climate, humans and fire. A chronology of the site was provided by radiocarbon dating. The dominant control on fire in this environment during the Holocene appears to be climate. Periods of climate change, identified in previous studies, are associated with higher levels of fire activity. Fire was less ubiquitous between ~9,000 and 6,000 years BP, a period normally described as having a higher effective moisture in south-eastern Australia. The mid-Holocene fluctuations in charcoal may reflect anthropogenic fire, climate forcing or alternatively human responses to any climate change. Coeval changes in palaeoclimatic sequences elsewhere and palynology at the site support a climatic explanation or that Aboriginal people used fire within a climatic framework.