Optimal resource extraction contract with adverse selection

This paper studies the design of a mining concession contract as a multi-period adverse selection problem where production is the depletion of a non renewable resource. Compared with symmetric information, we show that overproduction is optimal in the terminal phase of the resource extraction program. Moreover, asymmetric information lengthens the contract duration but reduces the scarcity rent.     

Comparing petroleum fiscal regimes under oil price uncertainty

This study investigates and compares five upstream petroleum fiscal systems under crude oil price uncertainty. The fiscal systems analyzed are: the Alberta Canada tax and royalty system, the Papua New Guinea (PNG) (pre-2003) traditional Rate of Return (ROR) system, the Sao Tome and Principe/Nigerian Joint Development Zone (SNJDZ) Production Sharing Contract (PSC), the Tanzanian PSC/ROR hybrid system and the Trinidad and Tobago PSC. Contingent claims analysis is used to value the governments’ tax claims under uncertainty using a numerical approach, viz., Monte Carlo simulation. Each system is tested to obtain the after-tax value accruing to firms as well as the distortionary effects introduced by the fiscal systems. The results are then ranked. The Alberta Canada and PNG fiscal systems provide companies with the highest after-tax values while also being the least distortionary. The Tanzanian system is the lowest in both rankings, providing relatively low after-tax values and introducing strong distortionary effects. The SNJDZ PSC imposed a relatively high tax burden on companies with median distortionary effects. The Trinidadian PSC generated a median tax burden on companies but has strong distortionary effects.     

Oil spills on other commodities

This paper examines the effect of crude oil prices on the prices of 35 internationally traded primary commodities for the 1960–2005 period. It finds that the pass-through of crude oil price changes to the overall non-energy commodity index is 0.16. At a more disaggregated level, the fertilizer index had the highest pass-through (0.33), followed by agriculture (0.17), and metals (0.11). The prices of precious metals also exhibited a strong response to crude oil price. In terms of individual commodities, the estimates of the food group exhibited remarkable similarity while those of raw materials and metals gave a mixed picture. The implication is that if crude oil prices remain high for some time, as most analysts expect, then the recent commodity price boom is likely to last much longer than earlier booms, at least for food commodities. The other commodities, however, are likely to follow diverging paths. On the methodological side, the results show that price indices, while providing useful summary statistics, they need to be supplemented by individual commodity analysis.     

Identifying Opportunities for Decision Support Systems in Support of Regional Resource Use Planning: An Approach Through Soft Systems Methodology

/ Regional resource use planning relies on key regional stakeholder groups using and having equitable access to appropriate social, economic, and environmental information and assessment tools. Decision support systems (DSS) can improve stakeholder access to such information and analysis tools. Regional resource use planning, however, is a complex process involving multiple issues, multiple assessment criteria, multiple stakeholders, and multiple values. There is a need for an approach to DSS development that can assist in understanding and modeling complex problem situations in regional resource use so that areas where DSSs could provide effective support can be identified, and the user requirements can be well established. This paper presents an approach based on the soft systems methodology for identifying DSS opportunities for regional resource use planning, taking the Central Highlands Region of Queensland, Australia, as a case study.     

响应面法优化制备污泥基活性炭

利用响应面法进行试验设计,选定炭化温度、升温速率、炭化停留时间及保护气体流量为影响因素,对利用污水厂二次污泥制备污泥基活性炭的工艺条件进行优化.通过响应面法得到了污泥基活性炭的碘吸附值与4种因素之间的非线性回归方程,确定了制备污泥基活性炭的最优工艺条件为:炭化温度530℃、升温速率17℃·min-1、炭化停留时间22 min、保护气体流量280 m L·min-1.在最优条件下,制备的污泥基活性炭碘吸附值为675.9 mg·g-1,比表面积为639.5 m2·g-1,平均孔径为4.1 nm,中孔孔径为3~5 nm;羧基、内酯基和酚羟基含量分别为1.625、0.125和0.375 mmol·g-1,更适合吸附大分子污染物和金属离子.     

水环境红线划定技术与管控措施初探

国家水环境红线是国家环境质量安全底线这一生态保护红线体系的三大要素之一,是国家生态保护红线中非常重要的组成部分.本文系统总结了国家水环境红线的概念、内涵和特征,重点阐述了国家水环境红线的划定流程和技术方法,并从“质量-排放-风险”全面介绍了国家水环境红线的管控措施,提出了加快推进国家水环境红线管理的3点建议.     

Optimized production of a novel bioflocculant M-C11 by Klebsiella sp. and its application in sludge dewatering

The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH 7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids（m/m）. A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl,methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C.The optimum bioflocculating activity was observed as 92.37% for 2.56 mL M-C11 and 0.37 g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration（SRF）decreased from 11.6 × 1012 to 4.7 × 1012m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents,such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.     

Q/SH0569-2013在建立环境监理管理体系中的应用

以山东液化天然气(LNG)项目为例,从环境监理的组织机构体系、管理及技术方法体系、管理程序及体系文件等方面,阐述了Q/SH0569-2013《建设项目环境监理技术规范(试行)》在港口码头及管道运输建设项目环境监理管理体系建立过程中的应用。     

Comamonas sp. IDO2合成靛蓝的特性研究

利用吲哚降解菌丛毛单胞菌(Comamonas)IDO2转化吲哚合成靛蓝,优化靛蓝合成条件,并对合成产物进行分析.结果表明,菌株IDO2能够在苯酚、萘、苯和菲的诱导下转化吲哚合成靛蓝,在苯酚诱导时靛蓝的产量最高.采用表面响应法优化菌株合成靛蓝的条件:吲哚197.76mg·L~(-1),苯酚203.39 mg·L~(-1),酵母浸粉0.18%,在此条件下靛蓝的合成量为9.0 mg·L~(-1),与初始条件下的产量相比提高了104%.此外,考察了不同金属离子对菌株IDO2合成靛蓝的影响,结果表明Ba~(2+)和Ca~(2+)对靛蓝的合成具有促进作用.采用液相色谱/飞行时间/质谱联用对菌株IDO2转化吲哚的产物进行定量和定性分析,发现合成产物主要为靛蓝和靛红,并依此提出了可能的反应途径.     

青贮秸秆活性炭的制备和改性及其对阿莫西林的吸附特性

为提高秸秆活性炭性能及其对AMX（阿莫西林）的吸附效果,研究了青贮秸秆活性炭的制备和改性方法及其对AMX的吸附特性.以青贮玉米秸秆为原料,通过响应面法（RSM）,在活化温度为584℃、浸渍比为1:1.9的条件下,制备了AC-S（青贮活性炭）和AC-SA（改性青贮活性炭）.通过比表面积和孔径分析,AC-S和AC-SA的S_BET（比表面积）分别为1 521、1 347 m2/g,两种活性炭兼具中孔和微孔.研究了吸附动力学、热力学特性及初始ρ(AMX)、pH对吸附结果的影响.结果表明,AC-S和AC-SA对AMX的最大吸附量分别为39.69、45.60 mg/L,均符合伪二级动力学模型和Langmuir吸附等温模型（R20.99）,吸附形式主要为化学吸附,在酸性条件下吸附量增加.研究显示,改性后AC-SA的酸性官能团增加45.31%,提高了其与AMX的碱性基团结合能力,因此对AMX的吸附效果更好.