Evaluating American Rainwater Harvesting Policy: A Case Study of Three U.S. Cities

In spite of increasing support for rainwater harvesting by public agencies, environmental organizations and well-defined industry guidelines, the researchers found a strikingly limited number of municipalities with formal rainwater harvesting policies and programs. With literature on rainwater harvesting limited to mostly instructional material, the researchers were compelled to examine the feasibility of rainwater harvesting guidelines and practices. International and domestic rainwater harvesting guidelines were considered. The researchers surveyed municipalities which have implemented rainwater harvesting policies and ordinances to determine the extent to which industry prescribed guidelines are feasible. The subject jurisdictions commonly regulated rainwater harvesting through ancillary city codes or programs though one enacted a stand-alone rainwater harvesting ordinance. The respondents evaluated system performance primarily through water conservation. The jurisdictions studied also concurred that identification of acceptable end-uses of rainwater and public education were the most feasible industry guidelines. System costs were identified as the main barrier to implementing rainwater harvesting. Economic subsidies and comprehensive planning policies were associated with program success

Flame spray synthesis under a non-oxidizing atmosphere: Preparation of metallic bismuth nanoparticles and nanocrystalline bulk bismuth metal

Metallic bismuth nanoparticles of over 98% purity were prepared by a modified flame spray synthesis method in an inert atmosphere by oxygen-deficient combustion of a bismuth-carboxylate based precursor. The samples were characterized by X-ray diffraction, thermal analysis and scanning electron microscopy confirming the formation of pure, crystalline metallic bismuth nanoparticles. Compression of the as-prepared powder resulted in highly dense, nanocrystalline pills with strong electrical conductivity and bright metallic glos

EOS: A project to investigate the design and construction of real-time distributed embedded operating systems

The EOS project is investigating the design and construction of a family of real-time distributed embedded operating systems for reliable, distributed aerospace applications. Using the real-time programming techniques developed in co-operation with NASA in earlier research, the project staff is building a kernel for a multiple processor networked system. The first six months of the grant included a study of scheduling in an object-oriented system, the design philosophy of the kernel, and the architectural overview of the operating system. In this report, the operating system and kernel concepts are described. An environment for the experiments has been built and several of the key concepts of the system have been prototyped. The kernel and operating system is intended to support future experimental studies in multiprocessing, load-balancing, routing, software fault-tolerance, distributed data base design, and real-time processing

Optimal investment and location decisions of a firm in a flood risk area using impulse control theory

Flooding events can affect businesses close to rivers, lakes or coasts. This paper provides an economic partial equilibrium model, which helps to understand the optimal location choice for a firm in flood risk areas and its investment strategies. How often, when and how much are firms willing to invest in flood risk protection measures? We apply Impulse Control Theory and develop a continuation algorithm to solve the model numerically. We find that, the higher the flood risk and the more the firm values the future, i.e. the more sustainable the firm plans, the more the firm will invest in flood defense. Investments in productive capital follow a similar path. Hence, planning in a sustainable way leads to economic growth. Sociohydrological feedbacks are crucial for the location choice of the firm, whereas different economic settings have an impact on investment strategies. If flood defense is already present, e.g. built up by the government, firms move closer to the water and invest less in flood defense, which allows firms to generate higher expected profits. Firms with a large initial productive capital surprisingly try not to keep their market advantage, but rather reduce flood risk by reducing exposed productive capital

Physico-Chemical Differences Between Particle- and Molecule-Derived Toxicity: Can We Make Inherently Safe Nanoparticles?

The rapidly growing applications of nanotechnology require a detailed understanding of benefits and risks, particularly in toxicology. The present study reviews the physical and chemical differences between particles and molecules when interacting with living organisms. In contrast to classical chemicals, the mobility of nanoparticles is governed by agglomeration, a clustering process that changes the characteristic size of the nanomaterials during exposure, toxicity tests or in the environment. The current status of nanotoxicology highlights non-classical toxic interactions through catalytic processes inside living cells and the enhanced heavy metal transport into the cytosol through the 'Trojan horse mechanism'. The safety of nanoparticles in consumer goods is proposed to be rendered inherently safer by substituting the currently used persistent oxides through biodegradable materials

What Does an Exemplary Middle School Mathematics Teacher Look Like? The Use of a Professional Development Rubric

A School University Research Network (SURN) committee composed of current mathematics teachers, central office math supervisors, building administrators, mathematicians, and mathematics educators researched numerous sources regarding best practices in mathematics instruction. The resulting professional development rubric synthesizes their findings and can serve a professional development role by providing teachers and administrators with a tool to develop clarity and consensus on best mathematics instructional practices, and how these practices are implemented in the classroom. It is also being used as a tool for cooperating teachers in their supervision of student teachers and as a reflective method for self-evaluation

A Dissipative-Particle-Dynamics Model for Simulating Dynamics of Charged Colloid

A mesoscopic colloid model is developed in which a spherical colloid is represented by many interacting sites on its surface. The hydrodynamic interactions with thermal fluctuations are taken accounts in full using Dissipative Particle Dynamics, and the electrostatic interactions are simulated using Particle-Particle-Particle Mesh method. This new model is applied to investigate the electrophoretic mobility of a charged colloid under an external electric field, and the influence of salt concentration and colloid charge are systematically studied. The simulation results show good agreement with predictions from the electrokinetic theory.Comment: 17 pages, 8 figures, submitted to the proceedings of High Performance Computing in Science & Engineering '1

Risk factors for 90-day readmission and return to the operating room following abdominal operations for Crohn's disease.

This study aimed to determine timing and risk factors for 30- and 90-day unplanned hospital readmissions and return to the operating room. Retrospective case series, including consecutive adult patients with Crohn's disease, undergoing a major abdominal surgical procedure during a 3.5-year inclusion period was performed. The primary outcomes were 0- to 30-day and 30- to 90-day readmission and return to the operating room rates. Univariate and multivariable risk factors for both outcomes at 30 and 90 days were assessed through Cox regression analysis. Of 680 included patients with Crohn's disease, 89 (13.1%) were readmitted within 30 days, 55 (8.1%) within 30-90 days, and 11 (1.6%) in both follow-up periods for a combined 90-day readmission rate of 24.4% (n = 166). Multivariable risk factors for 30-day readmissions were type of procedure performed, corticosteroid use (hazard ratio [HR] 1.71, P = .01), younger age (HR 0.98 per year, P = .01), and prolonged disease duration (HR 1.03 per year, P = .03). No significant risk factors identified for 30- to 90-day readmissions. By 90 days, 76 patients (11.2%) had a return to the operating room (of which 8.8% was within 30 days). Risk factors for 30-day return to the operating room included tobacco use (HR 1.86, P = .04), diabetes (HR 3.30, P = .01), corticosteroid use (HR 3.51, P <.001), and preoperative immunomodulator therapy (HR 2.70, P < .001). Type of surgery, corticosteroid use, younger age, and prolonged disease duration were associated with 30-day hospital readmission, and tobacco use, diabetes, corticosteroid use, and preoperative immunomodulator therapy were risk factors for 30-day return to the operating room. Postoperative biologic therapy did not increase hospital readmission or return to operating room rates within 90 days of surgery