Recycling wastewater for hydraulic fracturing by use of nanofiltration membranes

Hydraulic fracturing creates large volumes of produced water, contaminated with organics, suspended solids, and dissolved minerals. This water must either be disposed of in injection wells or treated for reuse. One option is to use a combination of ultrafiltration and nanofiltration to treat this water and reuse it in future hydraulic fracturing wells. The object of this study was to test and characterize commercial nanofiltration membranes. The work done for this project will lead to future work in modifying membranes to improve the rejection of desired components

Optimizing mating schemes in fish breeding

The optimal contribution selection method and the simulated annealing algorithm were used to maximize the genetic gain and reduce inbreeding in fish breeding populations. This study considered the following mating designs: full factorial (3 x 3); full factorial (6 x 6) and nested (6 males x 18 females). A quantitative trait based on a strictly additive and polygenic model was simulated. Two levels for the number of genotyped offspring (360 or 720) and three levels of heritability (0.1; 0.3; 0.5) were assumed. The best results in terms of DF and DG were obtained with the full factorial design (6 x 6) and considering a trait with a high heritability. The optimal family size was found at 20 fish per mating

Conceptualizing Student Practice for the 21st Century: Educational and Ethical Considerations in Modernizing the District of Columbia Student Practice Rules

This article traces the history of the amendment process. It provides a short history of student practice rules and then, using the student practice rule in effect in the District of Columbia prior to the 2014 amendments, describes the various components of those rules that courts and bars across the nation have implemented to assist courts, advance legal education, and preserve advocates’ ethical obligations to clients. It then describes some of the comments to the proposed amendments offered by the District of Columbia Bar and other D.C. lawyers during the public comment period and the modifications to the District of Columbia student practice rule that the District of Columbia Court of Appeals accepted. Finally, it discusses some areas of disagreement that arose during the process and a description of the reasons for those disagreements

Arguing satisfaction of security requirements

This chapter presents a process for security requirements elicitation and analysis, based around the construction of a satisfaction argument for the security of a system. The process starts with the enumeration of security goals based on assets in the system, then uses these goals to derive security requirements in the form of constraints. Next, a satisfaction argument for the system is constructed, using a problem-centered representation, a formal proof to analyze properties that can be demonstrated, and structured informal argumentation of the assumptions exposed during construction of the argument. Constructing the satisfaction argument can expose missing and inconsistent assumptions about system context and behavior that effect security, and a completed argument provides assurances that a system can respect its security requirements

Arguing security: validating security requirements using structured argumentation

This paper proposes using both formal and structured informal arguments to show that an eventual realized system can satisfy its security requirements. These arguments, called 'satisfaction arguments', consist of two parts: a formal argument based upon claims about domain properties, and a set of informal arguments that justify the claims. Building on our earlier work on trust assumptions and security requirements, we show how using satisfaction arguments assists in clarifying how a system satisfies its security requirements, in the process identifying those properties of domains that are critical to the requirements

A framework for security requirements engineering

This paper presents a framework for security requirements elicitation and analysis, based upon the construction of a context for the system and satisfaction arguments for the security of the system. One starts with enumeration of security goals based on assets in the system. These goals are used to derive security requirements in the form of constraints. The system context is described using a problem-centered notation, then this context is validated against the security requirements through construction of a satisfaction argument. The satisfaction argument is in two parts: a formal argument that the system can meet its security requirements, and a structured informal argument supporting the assumptions expressed in the formal argument. The construction of the satisfaction argument may fail, revealing either that the security requirement cannot be satisfied in the context, or that the context does not contain sufficient information to develop the argument. In this case, designers and architects are asked to provide additional design information to resolve the problems

A comparison of scores of kindergarten children and nonkindergarten children in specific background abilities at first grade entrance

Thesis (Ed.M.)--Boston Universit