基于生命周期的土壤源热泵系统CO2减排效果评价

基于生命周期理论,分别对土壤源热泵系统和溴化锂冷水机组/集中供热系统的CO2排放量进行计算,采用CO2回收期和减排量两个指标对土壤源热泵系统进行减排效果评价。计算结果表明,在建造阶段,管井钻探、热泵机组、聚乙烯管和置换土壤的CO2排放量分别占CO2排放总量的47%、31%、17%和5%。管井钻探过程在CO2排放总量中占主要地位,它具有减少CO2排放量的最大潜力。建造阶段土壤源热泵系统比溴化锂冷水机组/集中供热系统增加CO2排放量为224t,运行阶段土壤源热泵系统减少CO2排放量为237t/年。在整个生命周期(20年)内,土壤源热泵系统的CO2回收期为0.95年,减排量为4745t。     

Potentials of GHG reductions from wastewater treatment for the CDM

The study aims to evaluate the potential of GHG (greenhouse gas) reductions by installing an anaerobic digester in a wastewater treatment facility in Southeast Asia. Then the break-even point of additional investment to reduce GHG is obtained by exchanging carbon price as emissions credits. In the project scenario, the wastewater treatment system has the digester, where methane (biogas) is produced and recovered. Compared with the baseline scenario, the biogas has calorific value to produce heat and electri...     

Economy and CO2 emissions trade-off: A systematic approach for optimizing investments in process integration measures under uncertainty

In this paper we present a systematic approach for taking into account the resulting CO₂ emissions reductions from investments in process integration measures in industry when optimizing those investments under economic uncertainty. The fact that many of the uncertainties affecting investment decisions are related to future CO₂ emissions targets and policies implies that a method for optimizing not only economic criteria, but also greenhouse gas reductions, will provide better information to base the decisions on, and possibly also result in a more robust solution. In the proposed approach we apply a model for optimization of decisions on energy efficiency investments under uncertainty and regard the decision problem as a multiobjective programming problem. The method is applied to a case of energy efficiency investments at a chemical pulp mill. The case study is used to illustrate that the proposed method provides a good framework for decision-making about energy efficiency measures when considerations regarding greenhouse gas reductions influence the decisions. We show that by setting up the problem as a multiobjective programming model and at the same time incorporating uncertainties, the trade-off between economic and environmental criteria is clearly illustrated.     

Improving the training time of support vector regression algorithms through novel hyper-parameters search space reductions

The selection of hyper-parameters in support vector machines (SVM) is a key point in the training process of these models when applied to regression problems. Unfortunately, an exact method to obtain the optimal set of SVM hyper-parameters is unknown, and search algorithms are usually applied to obtain the best possible set of hyper-parameters. In general these search algorithms are implemented as grid searches, which are time consuming, so the computational cost of the SVM training process increases considerably. This paper presents a novel study of the effect of including reductions in the range of SVM hyper-parameters, in order to reduce the SVM training time, but with the minimum possible impact in its performance. The paper presents reduction in parameter C, by considering its relation with the rest of SVM hyper-parameters (γ and ε), through an approximation of the SVM model. On the other hand, we use some characteristics of the Gaussian kernel function and a previous result in the literature to obtain novel bounds for γ and ε hyper-parameters. The search space reductions proposed are evaluated in different regression problems from UCI and StatLib databases. All the experiments carried out applying the popular LIBSVM solver have shown that our approach reduces the SVM training time, maintaining the SVM performance similar to when the complete range in SVM parameters is considered.     

The problem of guaranteeing the absence of a complete set of reductions

This article is the twelfth of a series of articles discussing various open research problems in automated reasoning. Here we focus on finding criteria for guaranteeing the absence of a complete set of reductions. We include a suggestion for evaluating a proposed solution to this research problem.This work was supported by the Applied Mathematical Sciences subprogram of the Office of Energy Research, U.S. Department of Energy, under Contract W-31-109-Eng-38.     

An Explicit Lower Bound for TSP with Distances One and Two

Abstract. We show that, for any ɛ>0 , it is NP-hard to approximate the asymmetric traveling salesman problem with distances one and two within 2805/2804-ɛ . For the special case where the distance function is constrained to be symmetric, we show a lower bound of 5381/5380-ɛ , for any ɛ>0 . While it was previously known that there exists some constant, strictly greater than one, such that it is NP-hard to approximate the traveling salesman problem with distances one and two within that constant, this result is a first step towards the establishment of a good bound. In our proof we develop a new gadget construction to reduce from systems of linear equations mod 2 with two unknowns in each equation and at most three occurrences of each variable. Compared with earlier reductions to the traveling salesman problem with distances one and two, ours reduces the number of cities to less than a tenth of what was previously necessary.     

Future energy goals for Maryland: Greenhouse gas reductions

Legislative requirements in Maryland set very robust goals for the implementation of energy efficiency by utilities. Significant energy savings has been achieved in all customer sectors and efficiency gains have been made over time in equipment and building construction. Looking forward, utilities should implement programs to promote energy efficiency with a greater emphasis on GHG reductions. Feasibility studies need to occur, but flexibility is key given changing codes and standards and market transformation.     

天津中新生态城绿色建筑评价体系及节能效益研究

基于天津中新生态城绿色建筑标准,计算住宅楼全年负荷和CO2减排量及协同效益.中新生态城建筑比常规建筑每年减排527.867 kt CO2,在经济上可获得至少3523.512万元/年的收益.根据美国LEED绿色建筑评价标准对中新生态城进行了评价.中新生态城依据美国LEED评估体系得分为30分,符合美国LEED评价标准对绿...     

Synthesis of sex pheromones of lesser peachtree borer and peachtree borer

The sex pheromones produced by females of the lesser peachtree borer,Synanthedon pictipes (Grote and Robinson), and the peachtree borer,Synanthedon exitiosa (Say), (E,Z)- and (Z,Z)-3,13-octadecadien-1-ol acetate, respectively, were synthesized from 1,8-dichlorooctane, lithium acetylide, and ethylene oxide. In the course of the synthesis a new carbon-oxygen cleavage reaction of homopropargylic acetals was found, and the stereochemistry of the dissolving metal reductions of acetylenic alcohols was investigated.Mention of a commercial or proprietary product in this paper does not constitute an endorsement of that product by the USDA.     

K终端可靠度分解算法中多边形→链简化定理的完善

无向网络K终端可靠度的分解算法中,包括多边形→链简化在内的等可靠度简化和分解定理结合,可以降低算法的复杂度。本文完善了边随机无向网络和混合随机无向网络的4#,6#,7#型多边形→链简化定理。计算机编程验证了其正确性。