Simultaneous removal of nitrate and arsenic from drinking water sources utilizing a fixed-bed bioreactor system

A novel bioreactor system, consisting of two biologically active carbon (BAC) reactors in series, was developed for the simultaneous removal of nitrate and arsenic from a synthetic groundwater supplemented with acetic acid. A mixed biofilm microbial community that developed on the BAC was capable of utilizing dissolved oxygen, nitrate, arsenate, and sulfate as the electron acceptors. Nitrate was removed from a concentration of approximately 50 mg/L in the influent to below the detection limit of 0.2 mg/L. Biologically generated sulfides resulted in the precipitation of the iron sulfides mackinawite and greigite, which concomitantly removed arsenic from an influent concentration of approximately 200 ug/L to below 20 ug/L through arsenic sulfide precipitation and surface precipitation on iron sulfides. This study showed for the first time that arsenic and nitrate can be simultaneously removed from drinking water sources utilizing a bioreactor system.     

Vapor Pressure of Water in Mixtures with Hydrophilic Ionic Liquids – A Contribution to the Design of Processes for Drying of Gases by Absorption in Ionic Liquids

The low water vapor pressures of mixtures of water with the ionic liquids (ILs), [EMIM][EtSO₄] and [BEIM][EtSO₄], indicate that a process of gas dehydration by absorption in ILs might be an alternative to the classical absorption process with triethylene glycol (TEG). The activity coefficient for an infinite dilution of water in the IL (x_IL → 1), which should be low for efficient dehydration, is only about 0.2 for [EMIM][EtSO₄] compared to 0.6 for triethylene glycol. In contrast to TEG, losses by evaporation are excluded with ILs as solvents, because they have a negligible vapor pressure. The number of separation stages needed for the absorption in the IL and for the subsequent regeneration of the water‐loaded IL is small, about six and eight, respectively. IL regeneration can be achieved by distillation of water out of the IL (e.g., at 120 °C) and stripping with ambient air, which is not possible in the case of TEG (chemical attack by O₂).     

Influence of Bubble Evolution on the Effective Kinetics of Heterogeneously Catalyzed Gas/Liquid Reactions. Part I: Reactions with Gaseous Products

For heterogeneously catalyzed multiphase reactions the formation of bubbles may have an influence on mass and heat transfer as well as on the effective reaction rate. This first of two contributions deals with the Ni‐catalyzed decomposition of H₂O₂, which was used as a model system for an (almost) isothermal reaction with a gaseous product. (In part II the strongly exothermic hydrogenation of hexene will be analyzed, where gas/vapor bubbles may be generated by overheating of the catalyst.) The discharge of O₂ bubbles formed by decomposition of H₂O₂ enhances the external mass and heat transfer up to one order of magnitude. This is in analogy to the well‐known phenomena during nucleate boiling. The experiments and theoretical considerations also show that the internal mass transfer depends on the intensity of the reaction and thus on the H₂O₂ concentration, which is in contradiction to the classical Thiele approach. This discrepancy could be explained by a modified model that takes the formation of bubbles into account.     

Strategies of the Bulgarian vernacular: continuity in Bulgarian house design from National Revival times to the present day

The starting point of the article is the Bulgarian ‘National Revival House’ as it represents the most noteworthy product of Bulgarian vernacular architecture. It also demonstrates the meeting of European and West Asian building traditions: based on the Ottoman dwelling, the Bulgarian house shows an adaptation of the former to Christian Balkan living as well as the impact of various outside influences from the Ottoman Baroque to Central European models.

The examples date from the late eighteenth century to the present day, with an emphasis on the second half of the nineteenth century. They are encountered in rural, small-town and urban environments and exhibit a remarkable degree of basic uniformity of design: assemblage, lightness, cleanness of form and increasing monumentality are the most abiding characteristics of the Bulgarian ‘National Revival house’.

The thrust of this study is not so much towards a theoretical definition of the Bulgarian vernacular but more the analysis of the dominant architectural strategies in the design of domestic structures. After identifying the principal formal characteristics of the Bulgarian vernacular house, the aim is to demonstrate the continuity of those strategies into the modern period and to the present day. For this purpose, not only well-documented landmark buildings of the inter-War and Communist periods but also little-known examples will be considered. This will serve to establish the idea of a continuous Bulgarian vernacular as the common architecture of the people of Bulgaria.     

基于不同三组分模型解析生物质热解过程

三组分模型（three pseudocomponent model）通常被用来表征生物质热解过程。传统三组分模型中单个模型的反应级数被限定为1或3。在本研究过程中，利用非线性最小二乘法，在不限定反应级数的前提下回归三组分模型动力学参数（活化能、指前因子、反应级数）。通过研究发现，纤维素（cellulose）分解反应级数接近1，与前人结果相一致。木质素（lignin）分解级数与生物质种类有关，接近于1或3。半纤维素（hemicellulose）的分解过程最复杂，其反应级数在1.5～4之间变化。以Ozawa方法计算得到的活化能作为相对标准，对3种三组分模型进行比较，发现反应级数未确定时的模型比其他两种模型更精确地表征生物质热解过程。     

The use of psychoanalytic constructs in the service of empire: Comment on Baruch (2003).

Comments on an article by Baruch on psychoanalysis and terrorism (see record 2003-09630-009). The author believes that there is an extra-analytic space for articulating that which is beyond analysts' work with patients and for informing their understanding of history, culture, politics, gender, power, and other phenomena. The rules that govern psychoanalysts' "analysis" of these extra-analytic phenomena are, however, different from those that govern their work with patients. The complexities and vicissitudes of psychoanalytic discourse within analysts' clinical frame (their standard clinical practice) are different for phenomena on the "outside." In addition, clinical psychoanalytic discourse cannot stand outside the powerful narratives of power, gender, race, class, and empire. A psychoanalytic perspective is important in addressing extra-analytic issues only after analysts understand their relationship to power, gender, race, class, and empire. Just as analysts check themselves with supervision and careful countertransference reflection, they must also check themselves when they engage in extra-analytic work. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of helical parameters to generate candidate conformations for crystal packing: illustrative application to a polyimide

This communication describes the application and extension of a method for calculating the helical parameters with which to describe molecular conformations. The method, which was originally developed by Shimanouchi and others, is applied to a polyimide of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) and 2,2-dimethyl-1,3-(4-aminophenoxy)propane (DMDA) which has eight torsional bonds in the chemical repeat unit. Discrete low energy states for these torsions were determined by Ramanchandran energy maps of sequential dihedral pairs or single bond torsional energy diagrams. The total number of possible low energy conformations for these states is 1152 including conformationally related isoenantiomorphs. The method conveniently generates the conformations for subsequent crystal structure packing and refinement. Consideration of these together with the X-ray data of Cheng and co-workers reduces the number to about 15 with about a 2/1 conformation and a c axis of approximately 49.2 Å. Of these, about half appear to be good candidates for crystal packing.     

Foreground memory management in data path synthesis

The management of foreground memory is a main issue in data path synthesis. the storage of values in registers and register files not only determines the number of each of them but also has a major impact on the interconnect structure. Both the amount of multiplexing and interconnect are crucial factors to both the delay and area of a circuit. In this paper it is shown that when values are grouped into register files before being assigned to actual registers, significant savings (20 per cent) can be obtained in the number of local interconnections and the amount of global interconnect at the expense of only slightly more register area. These results can be enhanced by splitting the read and write phases of registers and even more by introducing serial (re)write operations for the same value. the value grouping is based on edge-colouring algorithms that provide a sharp upper bound on the number of register groups needed. After value grouping, the registers are allocated for each register file separately. Algorithms for register allocation published up till now have only considered loop-free data flow graphs. When these algorithms are applied to data flow graphs with loops, unnecessary register transfer operations can be introduced. In this paper a new algorithm is presented that performs a minimal register allocation eliminating all superfluous register transfer operations. Experiments on a benchmark set have shown that in all cases all register transfers could be eliminated at no increase in register cost. This paper provides a deeper insight to the computational complexity of some problems in the area of data path synthesis. It shows that the various subtasks can be solved exactly using polynomial time algorithms.