Hacia un manejo integrado de la degeneracion de la semilla de papa en Ecuador.

Peer Revie

Modeling the formation and composition of secondary organic aerosol from diesel exhaust using parameterized and semi-explicit chemistry and thermodynamic models

2017 Spring.Includes bibliographical references.Laboratory-based studies have shown that diesel-powered sources emit volatile organic compounds that can be photo-oxidized in the atmosphere to form secondary organic aerosol (SOA); in some cases, this SOA can exceed direct emissions of particulate matter (PM); PM is a criteria pollutant that is known to have adverse effects on air quality, climate, and human health. However, there are open questions surrounding how these laboratory experiments can be extrapolated to the real atmosphere and how they will help identify the most important species in diesel exhaust that contribute to SOA formation. Jathar et al. (2017) recently performed experiments using an oxidation flow reactor (OFR) to measure the photochemical production of SOA from a diesel engine operated at two different engine loads (idle, load), two fuel types (diesel, biodiesel) and two aftertreatment configurations (with and without an oxidation catalyst and particle filter). In this work, we will use two different SOA models, namely the volatility basis set (VBS) model and the statistical oxidation model (SOM), to simulate the formation, evolution and composition of SOA from the experiments of Jathar et al. (2017). Leveraging recent laboratory-based parameterizations, both frameworks accounted for a semi-volatile and reactive POA, SOA production from semi-volatile, intermediate-volatility and volatile organic compounds (SVOC, IVOC and VOC), NOx-dependent multigenerational gas-phase chemistry, and kinetic gas/particle partitioning. Both frameworks demonstrated that for model predictions of SOA mass and elemental composition to agree with measurements across all engine load-fuel-aftertreatment combinations, it was necessary to (a) model the kinetically-limited gas/particle partitioning likely in OFRs and (b) account for SOA formation from IVOCs (IVOCs were found to account for more than four-fifths of the model-predicted SOA). Model predictions of the gas-phase organic compounds (resolved in carbon and oxygen space) from the SOM compared favorably to gas-phase measurements made using a Chemical Ionization Mass Spectrometer (CIMS) that, qualitatively, substantiated the semi-explicit chemistry captured by the SOM and the measurements made by the CIMS. Sensitivity simulations suggested that (a) IVOCs from diesel exhaust could be modeled using a single surrogate species with an SOA mass yield equivalent to a C15 or C17 linear alkane for use in large-scale models, (b) different diesel exhaust emissions profiles in the literature resulted in the same SOA production as long as IVOCs were included and (c) accounting for vapor wall loss parameterizations for the SOA precursors improved model performance. As OFRs are increasingly used to study SOA formation and evolution in laboratory and field environments, there is a need to develop models that can be used to interpret the OFR data. This work is one example of the model development and application relevant to the use of OFRs

A Framework for Improved Intrusion Detection and Countermeasure Selection in Cloud Systems

No Abstrac

Analysis of dual-gripper manipulators and finite element analysis of the flexible laminated hose for underground storage tank cleanup

The second generation long-reach manipulator - the dual-gripper Phase 3 Remote Tool Delivery (RTD) system has been developed to retrieve radioactive waste from underground storage tanks with internal structural members. The RTD is equipped with two grippers, one at each end of the system, to grasp the structural member. A vertical translation mechanism is also added to the system that enables the vertical motion inside the tank. This special feature provides greater dexterity and flexibility. Two operating open-chain configurations are considered and modeled. The first configuration is that gripper 1 grasps the structural member and gripper 2 is free to perform a designated task. The other configuration is that gripper 2 grasps the structural member and gripper 1 is free to move. The kinematics, dynamics and simulation of the system are emphasized. Finite Element Analysis (FEA) of the flexible laminated hose used to convey radioactive waste materials was investigated to learn about its structural behavior. The hose is considered relatively fixed at one end (the outlet) and subjected to different loading conditions at the inlet. Liquid (mixture of water and sludge) with high viscosity is sucked through the hose using a vacuum pressure. The software package employed for FEA is ANSYS 5.2. A total of 200 cases, with different X, Y and Z loading conditions at the inlet, for the hose under the consideration with or without vacuum pressure have been analyzed. Numerical results and the ANSYS graphic outputs provided for each case include the deformation, stress distribution and strain distribution throughout the hose

Social facilitation of polydipsia as an animal model of compulsive behavior

Behavior excesses are a key feature in many psychiatric diagnoses. Obsessive-compulsive disorder (OCD), in particular, is almost entirely defined in terms of behavior excesses. Although much research has been conducted on OCD treatment, very little research has focused on understanding how these compulsive behaviors are acquired. The few theories advanced to explain the etiology of OCD compulsions have significant limitations. The purpose of this study is to test social facilitation as a potential mechanism through which compulsive behaviors are acquired, via an animal model. Schedule-induced polydipsia (SIP) was employed as the behavior of interest because there is empirical support indicating it as an animal model of compulsive behavior. The fundamental issue was to determine if naïve rats exposed to rats that drank reliably would (1) show elevated rates of drinking as a result of the exposure, and then (2) acquire SIP more rapidly than rats without that exposure. Twenty-four male Sprague-Dawley rats were randomly designated to be (1) drinking model rats, (2) drinking naïve rats, (3) feeding control model rats, (4)feeding control naïve rats, (5) social contact control model rats, (6) social contact control naïve rats, and (7) naïve control rats. SIP was established in the drinking model rats using a fixed-time 60-second schedule of food delivery (FT-60) with water available. Once stable drinking occurred, the models and their matched naïve rat were placed in the same experimental chamber to determine if drinking in the naïve rat would be socially facilitated. Strong individual differences in drinking by the naïve rats were observed. However, the overall indications were that social facilitation may play a role in enhancing the acquisition of SIP and that social facilitation may be a factor in the development of compulsive behavior

Modified Micro-Deval Procedure for Polishing of Fine Asphalt Mix Aggregates

A procedure combining Micro-Deval and 2nd generation Aggregate Imaging Measurement System (AIMS-II) test procedures was developed to characterize aggregate polishing characteristics, and in turn, provide a means for qualifying aggregate sources for friction purposes. This study focused on the minimum number of aggregate particles, aggregate sizes, and the number of revolutions in the Micro-Deval test. Only two aggregate sources were included in this study. Thus, further analyses are needed for wider range of aggregate sources/mineralogical properties in order to establish the minimum required aggregate shape properties for friction.IDOT-R27-SP36Ope

Assessment of Hydro-Chemical Changes in Nalgonda District: A Pre- and Post-Monsoon Comparison

Environmental fluids are crucial for the survival of all living organisms and are found in abundance throughout the Earth. Nowadays this environmental water is heavily polluted and is causing many health problems to the people, cattles, and plants using this water. Consequently, there are ongoing efforts to analyze the composition of environmental waters. However, the use of river water in various industries has resulted in water pollution, which poses a serious threat to life on Earth. As a response to this pollution, many have turned to groundwater as an alternative source. It is crucial to understand that surface water and groundwater are linked; pollution in surface water can affect groundwater quality, which in turn impacts the global water cycle. To address this issue, a comprehensive study was conducted in and around Nalgonda District, spanning both pre-monsoon (01-03-2023 to 31-05-2023) and post-monsoon (01-10-2023 to 31-12-2023) seasons in 2023. The study involved the collection of water samples from various bore-holes located at five different sites along the district. Fourteen key parameters, including pH, electrical conductivity, total dissolved solids, various ions, and specific ion interactions, were analyzed to assess the water quality in the region

Reduction of Elopement Using a Multicomponent Treatment in Young Children with ASD

Elopement, leaving a caregiver\u27s side without permission or supervision, is a behavior that is more prevalent among children with autism as compared to their typically developing peers. With potentially fatal consequences (e.g., exposure to water, traffic, and strangers), it is reported to cause high levels of stress for caregivers. In the present study, we evaluated the assessment and treatment of elopement using a multicomponent treatment package to address the multiple functions of elopement. Treatment consisted of verbal instructions, blocking, and differential reinforcement of other behaviors with extinction (DRO w/ EXT). An ABAB reversal design was utilized to assess treatment effectiveness. Results showed a significant reduction of elopement following the first phase of treatment for both participants. However, for one participant, previous reduction rates were not reached upon reimplementation. The implications for practice and limitations are discussed