Small-Chamber Measurements of Chemical-Specific Emission Factors for Drywall

Energy Technology Data Exchange (ETDEWEB)

Maddalena, Randy; Russell, Marion; Apte, Michael G.

2010-06-01

Imported drywall installed in U.S. homes is suspected of being a source of odorous and potentially corrosive indoor pollutants. To support an investigation of those building materials by the Consumer Products Safety Commission (CPSC), Lawrence Berkeley National Laboratory (LBNL) measured chemical-specific emission factors for 30 samples of drywall materials. Emission factors are reported for 75 chemicals and 30 different drywall samples encompassing both domestic and imported stock and incorporating natural, synthetic, or mixed gypsum core material. CPSC supplied all drywall materials. First the drywall samples were isolated and conditioned in dedicated chambers, then they were transferred to small chambers where emission testing was performed. Four sampling and analysis methods were utilized to assess (1) volatile organic compounds, (2) low molecular weight carbonyls, (3) volatile sulfur compounds, and (4) reactive sulfur gases. LBNL developed a new method that combines the use of solid phase microextraction (SPME) with small emission chambers to measure the reactive sulfur gases, then extended that technique to measure the full suite of volatile sulfur compounds. The testing procedure and analysis methods are described in detail herein. Emission factors were measured under a single set of controlled environmental conditions. The results are compared graphically for each method and in detailed tables for use in estimating indoor exposure concentrations.

Ecologically sustainable chemical recommendations for agricultural pest control?

Science.gov (United States)

Thomson, Linda J; Hoffmann, Ary A

2007-12-01

Effective pest control remains an essential part of food production, and it is provided both by chemicals and by natural enemies within agricultural ecosystems. These methods of control are often in conflict because of the negative impact of chemicals on natural enemies. There are already well-established approaches such as those provided by the International Organization for Biological and Integrated Control-Pesticides and Beneficial Organisms for testing, collecting, and publishing information on responses of natural enemies to chemicals based on laboratory responses of specific organisms; however, these tests do not assess the cumulative impact of chemical inputs across an entire season or consider impacts on the complex communities of natural enemies that can provide effective pest control on a farm. Here, we explore the potential of different approaches for assessing the impact of chemicals on agricultural ecosystems and we propose a simple metric for sustainable chemical use on farms that minimizes overall impact on beneficial groups. We suggest ways in which the effectiveness of metrics can be extended to include persistence and habitat features. Such metrics can assist farmers in developing targets for sustainable chemical use as demonstrated in the viticultural industry.

Chemical factors controlling actinide sorption in the environment

International Nuclear Information System (INIS)

Beall, G.W.; Allard, B.

1979-01-01

The solid geologic media and the aqueous phase are of equal importance for the retention of actinides in the environment. The composition of the water is largely determined by the mineralogical composition of the rock that it is in equilibrium with. The chemical form of the actinides and their sorption, are highly dependent on the composition of the water with respect to pH, redox potential, and concentration of anions like carbonate, phosphate, fluoride, and organic acids

Optimal control for chemical engineers

CERN Document Server

Upreti, Simant Ranjan

2013-01-01

Optimal Control for Chemical Engineers gives a detailed treatment of optimal control theory that enables readers to formulate and solve optimal control problems. With a strong emphasis on problem solving, the book provides all the necessary mathematical analyses and derivations of important results, including multiplier theorems and Pontryagin's principle.The text begins by introducing various examples of optimal control, such as batch distillation and chemotherapy, and the basic concepts of optimal control, including functionals and differentials. It then analyzes the notion of optimality, de

Chemical control methods and tools

Science.gov (United States)

Steven Manning; James. Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

Factors influencing chemical durability of nuclear waste glasses

International Nuclear Information System (INIS)

Feng, Xiangdong; Bates, J.K.

1993-01-01

A short summary is given of our studies on the major factors that affect the chemical durability of nuclear waste glasses. These factors include glass composition, solution composition, SA/V (ratio of glass surface area to the volume of solution), radiation, and colloidal formation. These investigations have enabled us to gain a better understanding of the chemical durability of nuclear waste glasses and to accumulate.a data base for modeling the long-term durability of waste glass, which will be used in the risk assessment of nuclear waste disposal. This knowledge gained also enhances our ability to formulate optimal waste glass compositions

Patterns in the Physical, Chemical, and Biological Composition of Icelandic Lakes and the Dominant Factors Controlling Variability Across Watersheds

Science.gov (United States)

Greco, A.; Strock, K.; Edwards, B. R.

2017-12-01

Fourteen lakes were sampled in the southern and western area of Iceland in June of 2017. The southern systems, within the Eastern Volcanic Zone, have minimal soil development and active volcanoes that produce ash input to lakes. Lakes in the Western Volcanic Zone were more diverse and located in older bedrock with more extensively weathered soil. Physical variables (temperature, oxygen concentration, and water clarity), chemical variables (pH, conductivity, dissolved and total nitrogen and phosphorus concentrations, and dissolved organic carbon concentration), and biological variables (algal biomass) were compared across the lakes sampled in these geographic regions. There was a large range in lake characteristics, including five to eighteen times higher algal biomass in the southern systems that experience active ash input to lakes. The lakes located in the Eastern Volcanic Zone also had higher conductivity and lower pH, especially in systems receiving substantial geothermal input. These results were analyzed in the context of more extensive lake sampling efforts across Iceland (46 lakes) to determine defining characteristics of lakes in each region and to identify variables that drive heterogeneous patterns in physical, chemical, and biological lake features within each region. Coastal systems, characterized by high conductivity, and glacially-fed systems, characterized by high iron concentrations, were unique from lakes in all other regions. Clustering and principal component analyses revealed that lake type (plateau, valley, spring-fed, and direct-runoff) was not the primary factor explaining variability in lake chemistry outside of the coastal and glacial lake types. Instead, lakes differentiated along a gradient of iron concentration and total nitrogen concentration. The physical and chemical properties of subarctic lakes are especially susceptible to both natural and human-induced environmental impacts. However, relatively little is known about the

Controlling organic chemical hazards in food manufacturing: a hazard analysis critical control points (HACCP) approach.

Science.gov (United States)

Ropkins, K; Beck, A J

2002-08-01

Hazard analysis by critical control points (HACCP) is a systematic approach to the identification, assessment and control of hazards. Effective HACCP requires the consideration of all hazards, i.e., chemical, microbiological and physical. However, to-date most 'in-place' HACCP procedures have tended to focus on the control of microbiological and physical food hazards. In general, the chemical component of HACCP procedures is either ignored or limited to applied chemicals, e.g., food additives and pesticides. In this paper we discuss the application of HACCP to a broader range of chemical hazards, using organic chemical contaminants as examples, and the problems that are likely to arise in the food manufacturing sector. Chemical HACCP procedures are likely to result in many of the advantages previously identified for microbiological HACCP procedures: more effective, efficient and economical than conventional end-point-testing methods. However, the high costs of analytical monitoring of chemical contaminants and a limited understanding of formulation and process optimisation as means of controlling chemical contamination of foods are likely to prevent chemical HACCP becoming as effective as microbiological HACCP.

Chemical Spill Prevention, Control, and Countermeasures Plan: 100 Areas

Energy Technology Data Exchange (ETDEWEB)

Chien, Y.M.

1989-06-01

The purpose of this Chemical Spill Prevention, Control, and Countermeasures (SPCC) Plan is to identify the chemical spill control practices, procedures, and containment devices Westinghouse Hanford Company (Westinghouse Hanford) employs to prevent a reportable quantity (RQ) of a hazardous substance (as defined in 40 CFR Part 302) from being released to the environment. The chemical systems and chemical storage facilities in the 100 Areas are described. This document traces the ultimate fate of accidental chemical spills at the 100 Areas. Also included in the document destinations, spill containment devices, and systems surveillance frequencies. 2 tabs.

Chemical Spill Prevention, Control, and Countermeasures Plan: 100 Areas

International Nuclear Information System (INIS)

Chien, Y.M.

1989-06-01

The purpose of this Chemical Spill Prevention, Control, and Countermeasures (SPCC) Plan is to identify the chemical spill control practices, procedures, and containment devices Westinghouse Hanford Company (Westinghouse Hanford) employs to prevent a reportable quantity (RQ) of a hazardous substance (as defined in 40 CFR Part 302) from being released to the environment. The chemical systems and chemical storage facilities in the 100 Areas are described. This document traces the ultimate fate of accidental chemical spills at the 100 Areas. Also included in the document destinations, spill containment devices, and systems surveillance frequencies. 2 tabs

Factors influencing recovery and restoration following a chemical incident.

Science.gov (United States)

Peña-Fernández, A; Wyke, S; Brooke, N; Duarte-Davidson, R

2014-11-01

Chemicals are an important part of our society. A wide range of chemicals are discharged into the environment every day from residential, commercial and industrial sources. Many of these discharges do not pose a threat to public health or the environment. However, global events have shown that chemical incidents or accidents can have severe consequences on human health, the environment and society. It is important that appropriate tools and technical guidance are available to ensure that a robust and efficient approach to developing a remediation strategy is adopted. The purpose of remediation is to protect human health from future exposure and to return the affected area back to normal as soon as possible. There are a range of recovery options (techniques or methods for remediation) that are applicable to a broad range of chemicals and incidents. Recovery options should be evaluated according to their appropriateness and efficacy for removing contaminants from the environment; however economic drivers and social and political considerations often influence decision makers on which remedial actions are implemented during the recovery phase of a chemical incident. To date, there is limited information in the literature on remediation strategies and recovery options that have been implemented following a chemical incident, or how successful they have been. Additional factors that can affect the approach taken for recovery are not well assessed or understood by decision makers involved in the remediation and restoration of the environment following a chemical incident. The identification of this gap has led to the development of the UK Recovery Handbook for Chemical Incidents to provide a framework for choosing an effective recovery strategy. A compendium of practical evidence-based recovery options (techniques or methods for remediation) for inhabited areas, food production systems and water environments has also been developed and is included in the chemical

In-reactor performance of methods to control fuel-cladding chemical interaction

International Nuclear Information System (INIS)

Weber, E.T.; Gibby, R.L.; Wilson, C.N.; Lawrence, L.A.; Adamson, M.G.

1979-01-01

Inner surface corrosion of austenitic stainless steel cladding by oxygen and reactive fission product elements requires a 50 μm wastage allowance in current FBR reference oxide fuel pin design. Elimination or reduction of this wastage allowance could result in better reactor efficiency and economics through improvements in fuel pin performance and reliability. Reduction in cladding thickness and replacement of equivalent volume with fuel result in improved breeding capability. Of the factors affecting fuel-cladding chemical interaction (FCCI), oxygen activity within the fuel pin can be most readily controlled and/or manipulated without degrading fuel pin performance or significantly increasing fuel fabrication costs. There are two major approaches to control oxygen activity within an oxide fuel pin: (1) control of total oxygen inventory and chemical activity (Δ anti GO 2 ) by use of low oxygen-to-metal ratio (O/M) fuel; and (2) incorporation of a material within the fuel pin to provide in-situ control of oxygen activity (Δ anti GO 2 ) and fixation of excess oxygen prior to, or in preference to reaction with the cladding. The paper describes irradiation tests which were conducted in EBR-II and GETR incorporating oxygen buffer/getter materials and very low O/M fuel to control oxygen activity in sealed fuel pins

Chemical control of flowering time

DEFF Research Database (Denmark)

Ionescu, Irina Alexandra; Møller, Birger Lindberg; Sánchez Pérez, Raquel

2017-01-01

Flowering at the right time is of great importance; it secures seed production and therefore species survival and crop yield. In addition to the genetic network controlling flowering time, there are a number of much less studied metabolites and exogenously applied chemicals that may influence...... on the genetic aspects of flowering time regulation in annuals, but less so in perennials. An alternative to plant breeding approaches is to engineer flowering time chemically via the external application of flower-inducing compounds. This review discusses a variety of exogenously applied compounds used in fruit...

Factors influencing choice of care-seeking for acute fever comparing private chemical shops with health centres and hospitals in Ghana: a study using case-control methodology.

Science.gov (United States)

Ansah, Evelyn K; Gyapong, Margaret; Narh-Bana, Solomon; Bart-Plange, Constance; Whitty, Christopher J M

2016-05-25

Several public health interventions to improve management of patients with fever are largely focused on the public sector yet a high proportion of patients seek care outside the formal healthcare sector. Few studies have provided information on the determinants of utilization of the private sector as against formal public sector. Understanding the differences between those who attend public and private health institutions, and their pathway to care, has significant practical implications. The chemical shop is an important source of care for acute fever in Ghana. Case-control methodology was used to identify factors associated with seeking care for fever in the Dangme West District, Ghana. People presenting to health centres, or hospital outpatients, with a history or current fever were compared to counterparts from the same community with fever visiting a chemical shop. Of 600 patients, 150 each, were recruited from the district hospital and two health centres, respectively, and 300 controls from 51 chemical shops. Overall, 103 (17.2 %) patients tested slide positive for malaria. Specifically, 13.7 % (41/300) of chemical shop patients, 30.7 % (46/150) health centre and 10.7 % (16/150) hospital patients were slide positive. While it was the first option for care for 92.7 % (278/300) chemical shop patients, 42.7 % (64/150) of health centre patients first sought care from a chemical shop. More health centre patients (61.3 %; 92/150) presented with fever after more than 3 days than chemical shop patients (27.7 %; 83/300) [AOR = 0.19; p private drug retail sector is the first option for the majority of patients, including poorer patients, with fever in this setting. Most patients with fever arrive at chemical shops with less delay and fewer signs of severity than at public health facilities. Improving chemical shop skills is a good opportunity to diagnose, treat or refer people with fever early.

Chemical Data Reporting: Factors to Consider When Using the Database

Science.gov (United States)

The 2012 Chemical Data Reporting (CDR) database provides non-confidential information on the manufacture, import, processing, and use of chemicals in commerce at national and regional levels. This fact sheet highlights factors to consider.

Physical and chemical trigger factors in environmental intolerance.

Science.gov (United States)

Claeson, Anna-Sara; Palmquist, Eva; Nordin, Steven

2018-04-01

Individuals with environmental intolerance (EI) react to exposure from different environmental sources at levels tolerated by most people and that are below established toxicological and hazardous thresholds. The main aim of this study was to determine the prevalence of attributing symptoms to chemical and physical sources in the environment among individuals with different forms of self-reported EI and in referents. Cross-sectional data from a population-based study, the Västerbotten Environmental Health Study (n = 3406), were used and individuals with self-reported EI to chemicals, buildings, electromagnetic fields and sounds as well as a group with multiple EIs were identified. The Environmental-Symptom Attribution Scale was used to quantify degree to which health symptoms are attributed to 40 specific environmental exposures and sources, with subscales referring to the four types of EI. All EI groups, except the group with building related intolerance (BRI), reported more symptoms from the expected sources compared to the referents. In addition, individuals with chemical and sound intolerance reported symptoms from building related trigger factors, and individuals with electromagnetic hypersensitivity reported symptoms from chemical trigger factors. The study suggests that individuals with BRI react to fewer and more specific trigger factors than do individuals with other EIs, and that it is important to ask about different sources since three of the EI groups attribute their symptoms to a wide variety of sources in addition to the sources to which their EI implicates. Copyright © 2018 Elsevier GmbH. All rights reserved.

Pollution control in oil, gas and chemical plants

CERN Document Server

Bahadori, Alireza

2014-01-01

This unique book covers the fundamental requirements for air, soil, noise and water pollution control in oil and gas refineries, chemical plants, oil terminals, petrochemical plants, and related facilities. Coverage includes design and operational considerations relevant to critical systems such as monitoring of water pollution control, equipment, and engineering techniques as well as engineering/technological methods related to soil, noise and air pollution control. This book also: ·         Covers a diverse list of pollution control strategies important to practitioners, ranging from waste water gathering systems and oil/suspended solids removal to chemical flocculation units, biological treatment, and sludge handling and treatment ·         Provides numerous step-by-step tutorials that orient both entry level and veteran engineers to the essentials of pollution control methods in petroleum and chemical industries ·         Includes a comprehensive glossary providing readers with...

Chemical control and design considerations for CANDU-PHW steam generators

International Nuclear Information System (INIS)

Frost, C.R.; Churchill, B.R.

1978-01-01

Ontario Hydro presently operates eight nuclear power units with a total capacitiy of about 4000 MW(e) net. Operating experience has been with Monel-400 and with Inconel-600 tubed steam generators using sodium phosphate or all volatile control of the boiler steam and water system. With a heavy water Heat Transport System, steam generator tube integrity is an essential ingredient of economical power production. Only three steam generator tube failures have occurred so far in about 40 unit-years operation. None was attributable to corrosion. Factors in the good reliability are, careful engineering design, good quality control at all stages of tubing and steam generator manufacture and close chemical control. The continuing evolution of our steam generator design means that future requirements will be more stringent. (author)

31 CFR 598.309 - Narcotic drug; controlled substance; listed chemical.

Science.gov (United States)

2010-07-01

...; listed chemical. 598.309 Section 598.309 Money and Finance: Treasury Regulations Relating to Money and... SANCTIONS REGULATIONS General Definitions § 598.309 Narcotic drug; controlled substance; listed chemical. The terms narcotic drug, controlled substance, and listed chemical have the meanings given those terms...

The influence of chemical degradation during dietary exposures to fish on biomagnification factors and bioaccumulation factors.

Science.gov (United States)

Arnot, Jon A; Mackay, Donald

2018-01-24

The chemical dietary absorption efficiency (E D ) quantifies the amount of chemical absorbed by an organism relative to the amount of chemical an organism is exposed to following ingestion. In particular, E D can influence the extent of bioaccumulation and biomagnification for hydrophobic chemicals. A new E D model is developed to quantify chemical process rates in the gastrointestinal tract (GIT). The new model is calibrated with critically evaluated measured E D values (n = 250) for 80 hydrophobic persistent chemicals. The new E D model is subsequently used to estimate chemical reaction rate constants (k R ) assumed to occur in the lumen of the GIT from experimental dietary exposure tests (n = 255) for 165 chemicals. The new k R estimates are corroborated with k R estimates for the same chemicals from the same data derived previously by other methods. The roles of k R and the biotransformation rate constant (k B ) on biomagnification factors (BMFs) determined under laboratory test conditions and on BMFs and bioaccumulation factors (BAFs) in the environment are examined with the new model. In this regard, differences in lab and field BMFs are highlighted. Recommendations to address uncertainty in E D and k R data are provided.

Study on chemical reactivity control of liquid sodium. Research program

International Nuclear Information System (INIS)

Saito, Jun-ichi; Ara, Kuniaki; Sugiyama, Ken-ichiro; Kitagawa, Hiroshi; Oka, Nobuki; Yoshioka, Naoki

2007-01-01

Liquid sodium has the excellent properties as coolant of the fast breeder reactor (FBR). On the other hand, it reacts high with water and oxygen. So an innovative technology to suppress the reactivity is desired. The purpose of this study is to control the chemical reactivity of liquid sodium by dispersing the nanometer-size metallic particles (we call them Nano-particles) into liquid sodium. We focus on the atomic interaction between Nano-particles and sodium atoms. And we try to apply it to suppress the chemical reactivity of liquid sodium. Liquid sodium dispersing Nano-particles is named 'Nano-fluid'. Research programs of this study are the Nano-particles production, the evaluation of reactivity suppression of liquid sodium and the feasibility study to FBR plant. In this paper, the research programs and status are described. The important factors for particle production were understood. In order to evaluate the chemical reactivity of Nano-fluid the research programs were planned. The feasibility of the application of Nano-fluid to the coolant of FBR plant was evaluated preliminarily from the viewpoint of design and operation. (author)

Estimation for Retention Factor of Isoflavones in Physico-Chemical Properties

International Nuclear Information System (INIS)

Lee, Seung Ki; Row, Kyung Ho

2003-01-01

The estimation of retention factors by correlation equations with physico-chmical properties maybe helpful in chromatographic work. The physico-chemical properties were water solubility (S), hydrophobicity (P), total energy (Et), connectivity index 1 (1χ), hydrophilic-lipophlic balance (x) and hydrophilic surface area (h) of isoflavones. The retention factors were experimentally measured by RP-HPLC. Especially, the empirical regulations of water solubility and hydrophobicity were expressed in a linear form. The equation between retention factors and various physico-chemical properties of isoflavones was suggested as k = a0 + a 1 log S + a2 log P Q + a3 (E t ) + a4 ( 1 χ) + a5 (x) + a6 (h), and the correlation coefficients estimated were relatively higher than 0.95. The empirical equations might be successfully used for a prediction of the various chromatographic characteristics of substances, with a similar chemical structure

Quantitative relations between chemical oxygen demand concentration and its influence factors in the sluice-controlled river reaches of Shaying River, China.

Science.gov (United States)

Dou, Ming; Li, Guiqiu; Li, Congying

2015-01-01

Recent research on the effects of dam and sluice construction on the water environment has attracted extensive attention from academia and governments alike. Because the operation of sluices greatly alters environmental factors such as water flow and sediment load, the water quality in sluice-controlled river reaches (SCRRs) undergoes complex changes compared with those in normal reaches. This work used river reaches near the Huaidian Sluice in Shaying River of China as a case study to analyse the effects of sluice operation on water quality evolution in SCRRs. The most influential factors affecting the rate of change in chemical oxygen demand (COD) concentration in SCRRs were identified through water quality monitoring experiments performed under various modes of sluice operation and by applying a statistical method 'partial correlation analysis'. Then, a hydrodynamic model incorporating sluice operation and a water quality transport and transform model incorporating the release of endogenous loads were developed. Using these two models, the processes of temporal and spatial change of COD concentrations in the SCRRs were simulated under various scenarios designed to represent the dominant factors of influence. Finally, the simulation results were used to develop empirical relationships between the rate of change in COD concentrations and the dominant factors of influence. The results reveal that three factors, i.e., water inflow concentration, gate opening size, and gate opening number, are the dominant factors of influence, and there are logarithmic relationships between the rate of change in COD concentration in the SCRRs and these factors.

Control of chemical dynamics by lasers: theoretical considerations.

Science.gov (United States)

Kondorskiy, Alexey; Nanbu, Shinkoh; Teranishi, Yoshiaki; Nakamura, Hiroki

2010-06-03

Theoretical ideas are proposed for laser control of chemical dynamics. There are the following three elementary processes in chemical dynamics: (i) motion of the wave packet on a single adiabatic potential energy surface, (ii) excitation/de-excitation or pump/dump of wave packet, and (iii) nonadiabatic transitions at conical intersections of potential energy surfaces. A variety of chemical dynamics can be controlled, if we can control these three elementary processes as we desire. For (i) we have formulated the semiclassical guided optimal control theory, which can be applied to multidimensional real systems. The quadratic or periodic frequency chirping method can achieve process (ii) with high efficiency close to 100%. Concerning process (iii) mentioned above, the directed momentum method, in which a predetermined momentum vector is given to the initial wave packet, makes it possible to enhance the desired transitions at conical intersections. In addition to these three processes, the intriguing phenomenon of complete reflection in the nonadiabatic-tunneling-type of potential curve crossing can also be used to control a certain class of chemical dynamics. The basic ideas and theoretical formulations are provided for the above-mentioned processes. To demonstrate the effectiveness of these controlling methods, numerical examples are shown by taking the following processes: (a) vibrational photoisomerization of HCN, (b) selective and complete excitation of the fine structure levels of K and Cs atoms, (c) photoconversion of cyclohexadiene to hexatriene, and (d) photodissociation of OHCl to O + HCl.

Physico-chemical and biotic factors influencing microalgal seed ...

African Journals Online (AJOL)

Physico-chemical and biotic factors influencing microalgal seed culture propagation for inoculation of a ... African Journal of Biotechnology ... used to inoculate an open raceway pond for large scale biomass production for biodiesel production.

Chemical barriers for controlling groundwater contamination

International Nuclear Information System (INIS)

Morrison, S.J.; Spangler, R.R.

1993-01-01

Chemical barriers are being explored as a low-cost means of controlling groundwater contamination. The barrier can intercept a contaminant plume and prevent migration by transferring contaminants from the groundwater to immobile solids. A chemical barrier can be emplaced in a landfill liner or in an aquifer cutoff wall or can be injected into a contaminant plume. Chemical barriers can be classified as either precipitation barriers or sorption barriers depending upon the dominant mode of contaminant extraction. In a precipitation barrier, contaminants are bound in the structures of newly formed phases; whereas, in a sorption barrier, contaminants attach to the surfaces of preexisting solids by adsorption or some other surface mechanism. Sorption of contaminants is pH dependent. A precipitation barrier can control the pH of the system, but alkaline groundwater may dominate the pH in a sorption barrier. A comparison is made of the characteristics of precipitation and sorption barriers. Experimental data on the extraction of uranium and molybdenum from simulated groundwater are used to demonstrate these concepts. 10 refs., 9 figs., 1 tab

Determinants of job stress in chemical process industry: A factor analysis approach.

Science.gov (United States)

Menon, Balagopal G; Praveensal, C J; Madhu, G

2015-01-01

Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

Computer Controlled Chemical Micro-Reactor

International Nuclear Information System (INIS)

Mechtilde, Schaefer; Eduard, Stach; Adreas, Foitzik

2006-01-01

Chemical reactions or chemical equilibria can be influenced and controlled by several parameters. The ratio of two liquid ingredients, the so called reactants or educts, plays an important role in determining the end product and its yield. The reactants must be weighed and accordingly mixed with the conventional batch mode. If the reaction is done in a microreactor or in several parallel working micro-reactors, units for allotting the educts in appropriate quantities are required. In this report we present a novel micro-reactor that allows the constant monitoring of the chemical reaction via Raman spectroscopy. Such monitoring enables an appropriate feedback on the steering parameters for the PC controlled micro-pumps for the appropriate educt flow rate of both liquids to get optimised ratios of ingredients at an optimised total flow rate. The micro-reactors are the core pieces of the design and are easily removable and can therefore be changed at any time to adapt the requirements of the chemical reaction. One type of reactor consists of a stainless steel base containing small scale milled channels covered with anodically bonded Pyrex glass. Another type of reactor has a base of anisotropically etched silicon, and is also covered with anodically bonded Pyrex glass. The glass window allows visual observation of the initial phase interface of the two educts in the reaction channels by optical microscopy and does not affect, in contrast to infrared spectroscopy, the Raman spectroscopic signal for detection of the reaction kinetics. On the basis of a test reaction, we present non-invasive and spatially highly resolved in-situ reaction analysis using Raman spectroscopy measured along the reaction channel at different locations

WEED CONTROL EFFECTS ON SOIL CHEMICAL CHARACTERISTICS

Directory of Open Access Journals (Sweden)

Paulo Sérgio Lima e Silva

2008-01-01

Full Text Available The weed control procedures are known to affect the soil physical attributes and the nutrient amount taken up by weed roots. This work hypothesis is that weed control methods might also affect soil chemical attributes. Four experiments were carried out, three with maize (E-1, E-2 and E-3 and one with cotton (E-4, in randomized complete blocks design arranged in split-plots, with five replications. In E-1 experiment, the plots consisted of two weed control treatments: no-weed control and weed shovel-digging at 20 and 40 days after sowing; and the subplots consisted of six maize cultivars. In the three other experiments, the plots consisted of plant cultivars: four maize cultivars (E-2 and E-3 and four cotton cultivars (E-4. And, the subplots consisted of three weed control treatments: (1 no-weed control; (2 weed shovel-digging at 20 and 40 days after sowing; and (3 intercropping with cowpea (E-2 or Gliricidia sepium (Jacq. Walp. (E-3 and E-4. In all experiments, after harvest, eight soil samples were collected from each subplot (0-20 cm depth and composed in one sample. Soil chemical analysis results indicated that the weed control by shovel-digging or intercropping may increase or decrease some soil element concentrations and the alterations depend on the element and experiment considered. In E-2, the weed shovel-dug plots showed intermediate soil pH, lower S (sum of bases values and higher soil P concentrations than the other plots. In E-4, soil K and Na concentrations in plots without weed control did not differ from plots with intercropping, and in both, K and Na values were higher than in weed shovel-dug plots. Maize and cotton cultivars did not affect soil chemical characteristics.

Femtosecond laser control of chemical reaction of carbon monoxide and hydrogen

CSIR Research Space (South Africa)

Du Plessis, A

2010-09-01

Full Text Available Femtosecond laser control of chemical reactions is made possible through the use of pulse-shaping techniques coupled to a learning algorithm feedback loop – teaching the laser pulse to control the chemical reaction. This can result in controllable...

Dynamics and Control of Chemical Reactors-Selectively Surveyed

DEFF Research Database (Denmark)

Jørgensen, S. B.; Jensen, N.

1989-01-01

The chemical reactor or bioreactor is physically at a central position in a process, and often with a decisive role on the overall technical and economical performance. Even though application of feedback control on reactors is gaining momentum and on-line optimization has been implemented....... For bioreactors the theory and practice of reactor design, dynamics and control have to be adapted to the peculiarities of the biological catalysts. Enzymes, the protein catalysts, are the simplest ones, which have many common features with chemical catalysts. The living cells are much more complex, these growing...... in industry, many reactor control problems are still left unsolved or only partly solved using open loop strategies where disturbance rejection and model inaccuracies have to be handled through manual reactor control and feedback control of raw material preprocessing and product purification operations...

[Prospects in getting accordance between chemical analytic control means and medical technical requirements to safety system concerning chemical weapons destruction].

Science.gov (United States)

Rembovskiĭ, V R; Mogilenkova, L A; Savel'eva, E I

2005-01-01

The major unit monitoring chemical weapons destruction objects is a system of chemical analyticcontrol over the technologic process procedures and possibility of environment and workplace pollution withtoxicchemicals and their destruction products. At the same time, physical and chemical control means meet sanitary and hygienic requirements incompletely. To provide efficient control, internationally recognized approaches should be adapted to features of Russian system monitoring pollution of chemical weapons destruction objects with toxic chemicals.

Environmental and occupational risk factors for progressive supranuclear palsy: Case-control study.

Science.gov (United States)

Litvan, Irene; Lees, Peter S J; Cunningham, Christopher R; Rai, Shesh N; Cambon, Alexander C; Standaert, David G; Marras, Connie; Juncos, Jorge; Riley, David; Reich, Stephen; Hall, Deborah; Kluger, Benzi; Bordelon, Yvette; Shprecher, David R

2016-05-01

The cause of progressive supranuclear palsy (PSP) is largely unknown. Based on evidence for impaired mitochondrial activity in PSP, we hypothesized that the disease may be related to exposure to environmental toxins, some of which are mitochondrial inhibitors. This multicenter case-control study included 284 incident PSP cases of 350 cases and 284 age-, sex-, and race-matched controls primarily from the same geographical areas. All subjects were administered standardized interviews to obtain data on demographics, residential history, and lifetime occupational history. An industrial hygienist and a toxicologist unaware of case status assessed occupational histories to estimate past exposure to metals, pesticides, organic solvents, and other chemicals. Cases and controls were similar on demographic factors. In unadjusted analyses, PSP was associated with lower education, lower income, more smoking pack-years, more years of drinking well water, more years living on a farm, more years living 1 mile from an agricultural region, more transportation jobs, and more jobs with exposure to metals in general. However, in adjusted models, only more years of drinking well water was significantly associated with PSP. There was an inverse association with having a college degree. We did not find evidence for a specific causative chemical exposure; higher number of years of drinking well water is a risk factor for PSP. This result remained significant after adjusting for income, smoking, education and occupational exposures. This is the first case-control study to demonstrate PSP is associated with environmental factors. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

Testing the control of mineral supply rates on chemical erosion in the Klamath Mountains

Science.gov (United States)

West, N.; Ferrier, K.

2017-12-01

The relationship between rates of chemical erosion and mineral supply is central to many problems in Earth science, including the role of tectonics in the global carbon cycle, nutrient supply to soils and streams via soil production, and lithologic controls on landscape evolution. We aim to test the relationship between mineral supply rates and chemical erosion in the forested uplands of the Klamath mountains, along a latitudinal transect of granodioritic plutons that spans an expected gradient in mineral supply rates associated with the geodynamic response to the migration of the Mendocino Triple Junction. We present 10Be-derived erosion rates and Zr-derived chemical depletion factors, as well as bulk soil and rock geochemistry on 10 ridgetops along the transect to test hypotheses about supply-limited and kinetically-limited chemical erosion. Previous studies in this area, comparing basin-averaged erosion rates and modeled uplift rates, suggest this region may be adjusted to an approximate steady state. Our preliminary results suggest that chemical erosion at these sites is influenced by both mineral supply rates and dissolution kinetics.

Towards benchmarking of multivariable controllers in chemical/biochemical industries: Plantwide control for ethylene glycol production

DEFF Research Database (Denmark)

Huusom, Jakob Kjøbsted; Bialas, Dawid Jan; Jørgensen, John Bagterp

2011-01-01

In this paper we discuss a simple yet realistic benchmark plant for evaluation and comparison of advanced multivariable control for chemical and biochemical processes. The benchmark plant is based on recycle-separator-recycle systems for ethylene glycol production and implemented in Matlab...... for education purposes (operator training, student education, etc) as well as scientific research into chemical process control where it enables rapid evaluation and comparison of advanced multivariable controllers as demonstrated in this study....

The statutory approach: the control of chemical products

International Nuclear Information System (INIS)

Briens, F.

1997-01-01

The evaluation and management of risks linked with chemical products and in particular with petroleum products is now performed using all the available tools developed by the OECD or the European Union in order to harmonize the procedures between member states. This paper describes the statutory liabilities linked to the trade of chemical products of industrial use in the case of new and of existing chemical substances (classification, labelling, risk evaluation and reduction, physico-chemical properties, toxicological and eco-toxicological studies, neutralization, limitation of trade and use, import/export, protection of the ozone layer, etc..). It refers to the legal framework (orders, by-laws, decrees, guidelines..) defined by the OECD and the European Community and recalls the organization and administration of the competent authorities for the control of chemical products. (J.S.)

Compatible biological and chemical control systems for Rhizoctonia solani in potato

NARCIS (Netherlands)

Boogert, van den P.H.J.F.; Luttikholt, A.J.G.

2004-01-01

A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals,

Intelligent Controller Design for a Chemical Process

OpenAIRE

Mr. Glan Devadhas G; Dr.Pushpakumar S.

2010-01-01

Chemical process control is a challenging problem due to the strong on*line non*linearity and extreme sensitivity to disturbances of the process. Ziegler – Nichols tuned PI and PID controllers are found to provide poor performances for higher*order and non–linear systems. This paper presents an application of one*step*ahead fuzzy as well as ANFIS (adaptive*network*based fuzzy inference system) tuning scheme for an Continuous Stirred Tank Reactor CSTR process. The controller is designed based ...

ANALYTICAL SYNTHESIS OF CHEMICAL REACTOR CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

Alexander Labutin

2017-02-01

Full Text Available The problem of the analytical synthesis of the synergetic control system of chemical reactor for the realization of a complex series-parallel exothermal reaction has been solved. The synthesis of control principles is performed using the analytical design method of aggregated regulators. Synthesized nonlinear control system solves the problem of stabilization of the concentration of target component at the exit of reactor and also enables one to automatically transfer to new production using the equipment.

CHEMICAL CONTROL OF BEAN WEEVIL, ACANTHOSCELIDES OBTECTUS SAY IN STORAGE CONDITION

Directory of Open Access Journals (Sweden)

M PORCA

2003-12-01

Full Text Available The paper presents the positive results obtained by some pesticides applied against the bean weevil - Acanthoscelides obtectus Say, after a synthetic rewiew of the potential chemical methods which may be used in the chemical control of the insectes harmful to the stored bean seeds. The chemical control is realised treatments wits syntetic pyrethroid (permetrin, deltametrin and organophosphoric insecticides (malation, pirimifos metil, fenitrotion and chlrorpirifos-metil.

Interactions between toxic chemicals and natural environmental factors--a meta-analysis and case studies.

Science.gov (United States)

Laskowski, Ryszard; Bednarska, Agnieszka J; Kramarz, Paulina E; Loureiro, Susana; Scheil, Volker; Kudłek, Joanna; Holmstrup, Martin

2010-08-15

The paper addresses problems arising from effects of natural environmental factors on toxicity of pollutants to organisms. Most studies on interactions between toxicants and natural factors, including those completed in the EU project NoMiracle (Novel Methods for Integrated Risk Assessment of Cumulative Stressors in Europe) described herein, showed that effects of toxic chemicals on organisms can differ vastly depending purely on external conditions. We compiled data from 61 studies on effects of temperature, moisture and dissolved oxygen on toxicity of a range of chemicals representing pesticides, polycyclic aromatic hydrocarbons, plant protection products of bacterial origin and trace metals. In 62.3% cases significant interactions (pnatural factors and chemicals were found, reaching 100% for the effect of dissolved oxygen on toxicity of waterborne chemicals. The meta-analysis of the 61 studies showed that the null hypothesis assuming no interactions between toxic chemicals and natural environmental factors should be rejected at p=2.7 x 10(-82) (truncated product method probability). In a few cases of more complex experimental designs, also second-order interactions were found, indicating that natural factors can modify interactions among chemicals. Such data emphasize the necessity of including information on natural factors and their variation in time and across geographic regions in ecological risk assessment. This can be done only if appropriate ecotoxicological test designs are used, in which test organisms are exposed to toxicants at a range of environmental conditions. We advocate designing such tests for the second-tier ecological risk assessment procedures. Copyright 2010 Elsevier B.V. All rights reserved.

Physico-chemical quality control 131I-sodium 2-iodohippurate

International Nuclear Information System (INIS)

Morin, J.; Olive, E.; Issac, M.; Cruz, J.

1992-01-01

Some physico-chemical methods for analytical control 131 I-sodium 2-iodohippurate are compared. The most convenient to applicate in hospital and in more especialized quality control laboratories are recommended

Hierarchical optimal control of large-scale nonlinear chemical processes.

Science.gov (United States)

Ramezani, Mohammad Hossein; Sadati, Nasser

2009-01-01

In this paper, a new approach is presented for optimal control of large-scale chemical processes. In this approach, the chemical process is decomposed into smaller sub-systems at the first level, and a coordinator at the second level, for which a two-level hierarchical control strategy is designed. For this purpose, each sub-system in the first level can be solved separately, by using any conventional optimization algorithm. In the second level, the solutions obtained from the first level are coordinated using a new gradient-type strategy, which is updated by the error of the coordination vector. The proposed algorithm is used to solve the optimal control problem of a complex nonlinear chemical stirred tank reactor (CSTR), where its solution is also compared with the ones obtained using the centralized approach. The simulation results show the efficiency and the capability of the proposed hierarchical approach, in finding the optimal solution, over the centralized method.

Chemical inventory control program for mixed and hazardous waste facilities at SRS

International Nuclear Information System (INIS)

Ades, M.J.; Vincent, A.M. III.

1997-01-01

Mixed Waste (MW) and Hazardous Waste (HW) are being stored at the Savannah River Site (SRS) pending onsite and/or offsite treatment and disposal. The inventory control for these wastes has recently been brought under Technical Safety Requirements (TSR) in accordance with DOE Order 5480.22. With the TSRs was the question of the degree of rigor with which the inventory is to be tracked, considering that the variety of chemicals present, or that could be present, numbers in the hundreds. This paper describes the graded approach program to track Solid Waste (SW) inventories relative to TSRs. The approach uses a ratio of the maximum anticipated chemical inventory to the permissible inventory in accordance with Emergency Response Planning Guideline (ERPG) limits for on- and off-site receptors. A specific threshold ratio can then be determined. The chemicals above this threshold ratio are to be included in the chemical inventory control program. The chemicals that fall below the threshold ratio are managed in accordance with existing practice per State and RCRA hazardous materials requirements. Additionally, the facilities are managed in accordance with process safety management principles, specifically using process hazards analyses, which provides safety assurance for even the small quantities that may be excluded from the formal inventory control program. The method yields a practical approach to chemical inventory control, while maintaining appropriate chemical safety margins. The resulting number of specific chemicals that require inclusion in a rigorous inventory control program is greatly reduced by about 80%, thereby resulting in significant reduction in chemical data management while preserving appropriate safety margins

Incorporation of chemical kinetic models into process control

International Nuclear Information System (INIS)

Herget, C.J.; Frazer, J.W.

1981-01-01

An important consideration in chemical process control is to determine the precise rationing of reactant streams, particularly when a large time delay exists between the mixing of the reactants and the measurement of the product. In this paper, a method is described for incorporating chemical kinetic models into the control strategy in order to achieve optimum operating conditions. The system is first characterized by determining a reaction rate surface as a function of all input reactant concentrations over a feasible range. A nonlinear constrained optimization program is then used to determine the combination of reactants which produces the specified yield at minimum cost. This operating condition is then used to establish the nominal concentrations of the reactants. The actual operation is determined through a feedback control system employing a Smith predictor. The method is demonstrated on a laboratory bench scale enzyme reactor

Improvement of chemical control in the water-steam cycle of thermal power plants

International Nuclear Information System (INIS)

Rajakovic-Ognjanovic, Vladana N.; Zivojinovic, Dragana Z.; Grgur, Branimir N.; Rajakovic, Ljubinka V.

2011-01-01

A more effective chemical control in the water-steam cycle (WSC) of thermal power plants (TPP) is proposed in this paper. Minimization of corrosion effects by the production of ultra pure water and its strict control is the basis of all the investigated processes. The research involved the analysis of water samples in the WSC through key water quality parameters and by the most convenient analytical tools. The necessity for the stricter chemical control is demonstrated through a concrete example of the TPP Nikola Tesla, Serbia. After a thorough analysis of the chemical control system of the WSC, diagnostic and control parameters were chosen for continuous systematic measurements. Sodium and chloride ions were recognized as the ions which indicate the corrosion potential of the water and give insight into the proper production and maintenance of water within the WSC. Chemical transformations of crucial corrosion elements, iron and silica, were considered and related to their quantitative values. - Research highlights: → The more effective chemical control in the water-steam cycle of thermal power plant Nikola Tesla, Serbia. → In chemical control the diagnostic and control parameters were optimized and introduced for the systematic measurements in the water-steam cycle. → Sodium and chloride ions were recognized as ions which indicate corrosion potential of water and give insight to proper function of production and maintenance of water within water-team cycle. → Chemical transformations of crucial corrosion elements, iron and silica are considered and related with their quantitative values.

Chemical sensors and gas sensors for process control in biotechnology

International Nuclear Information System (INIS)

Williams, D.E.

1988-04-01

This paper is concerned with the possibilities for chemical measurement of the progress of biotechnological processes which are offered by devices already developed for other demanding applications. It considers the potential use of ultrasonic instrumentation originally developed for the nuclear industry, gas measurement methods from the fields of environmental monitoring and combustion control, nuclear instruments developed for the oil, mining and chemical industries, robotic systems and advanced control techniques. (author)

The Red Queen in a potato field: integrated pest management versus chemical dependency in Colorado potato beetle control.

Science.gov (United States)

Alyokhin, Andrei; Mota-Sanchez, David; Baker, Mitchell; Snyder, William E; Menasha, Sandra; Whalon, Mark; Dively, Galen; Moarsi, Wassem F

2015-03-01

Originally designed to reconcile insecticide applications with biological control, the concept of integrated pest management (IPM) developed into the systems-based judicious and coordinated use of multiple control techniques aimed at reducing pest damage to economically tolerable levels. Chemical control, with scheduled treatments, was the starting point for most management systems in the 1950s. Although chemical control is philosophically compatible with IPM practices as a whole, reduction in pesticide use has been historically one of the main goals of IPM practitioners. In the absence of IPM, excessive reliance on pesticides has led to repeated control failures due to the evolution of resistance by pest populations. This creates the need for constant replacement of failed chemicals with new compounds, known as the 'insecticide treadmill'. In evolutionary biology, a similar phenomenon is known as the Red Queen principle - continuing change is needed for a population to persevere because its competitors undergo constant evolutionary adaptation. The Colorado potato beetle, Leptinotarsa decemlineata (Say), is an insect defoliator of potatoes that is notorious for its ability to develop insecticide resistance. In the present article, a review is given of four case studies from across the United States to demonstrate the importance of using IPM for sustainable management of a highly adaptable insect pest. Excessive reliance on often indiscriminate insecticide applications and inadequate use of alternative control methods, such as crop rotation, appear to expedite evolution of insecticide resistance in its populations. Resistance to IPM would involve synchronized adaptations to multiple unfavorable factors, requiring statistically unlikely genetic changes. Therefore, integrating different techniques is likely to reduce the need for constant replacement of failed chemicals with new ones. © 2014 Society of Chemical Industry.

Speleothems as Examples of Chemical Equilibrium Processes.

Science.gov (United States)

Wilson, James R.

1984-01-01

The chemical formation of speleothems such as stalactites and stalagmites is poorly understood by introductory geology instructors and misrepresented in most textbooks. Although evaporation may be a controlling factor in some caves, it is necessary to consider chemical precipitation as more important in controlling the diagenesis of calcium…

Subfemtosecond directional control of chemical processes in molecules

Science.gov (United States)

Alnaser, Ali S.; Litvinyuk, Igor V.

2017-02-01

Laser pulses with a waveform-controlled electric field and broken inversion symmetry establish the opportunity to achieve directional control of molecular processes on a subfemtosecond timescale. Several techniques could be used to break the inversion symmetry of an electric field. The most common ones include combining a fundamental laser frequency with its second harmonic or with higher -frequency pulses (or pulse trains) as well as using few-cycle pulses with known carrier-envelope phase (CEP). In the case of CEP, control over chemical transformations, typically occurring on a timescale of many femtoseconds, is driven by much faster sub-cycle processes of subfemtosecond to few-femtosecond duration. This is possible because electrons are much lighter than nuclei and fast electron motion is coupled to the much slower nuclear motion. The control originates from populating coherent superpositions of different electronic or vibrational states with relative phases that are dependent on the CEP or phase offset between components of a two-color pulse. In this paper, we review the recent progress made in the directional control over chemical processes, driven by intense few-cycle laser pulses a of waveform-tailored electric field, in different molecules.

ZnO UV photodetector with controllable quality factor and photosensitivity

Directory of Open Access Journals (Sweden)

L. C. Campos

2013-02-01

Full Text Available ZnO nanowires have an enormous potential for applications as ultra-violet (UV photodetectors. Their mechanism of photocurrent generation is intimately related with the presence of surface states where considerable efforts, such as surface chemical modifications, have been pursued to improve their photodetection capabilities. In this work, we report a step further in this direction demonstrating that the relative photosensitivity and quality factor (Q factor of the photodetector are entirely tunable by an applied gate voltage. This mechanism enables UV photodetection selectivity ranging from wavelengths from tens of nanometers (full width at half maximum - FWHM down to a narrow detection of 3 nm. Such control paves the way for novel applications, especially related to the detection of elements that have very sharp luminescence.

Materials Safety Data Sheets: the basis for control of toxic chemicals

Energy Technology Data Exchange (ETDEWEB)

Ketchen, E.E.; Porter, W.E.

1979-09-01

The Material Safety Data Sheets contained in this volume are the basis for the Toxic Chemical Control Program developed by the Industrial Hygiene Department, Health Division, ORNL. The three volumes are the update and expansion of ORNL/TM-5721 and ORNL/TM-5722 Material Safety Data Sheets: The Basis for Control of Toxic Chemicals, Volume I and Volume II. As such, they are a valuable adjunct to the data cards issued with specific chemicals. The chemicals are identified by name, stores catalog number where appropriate, and sequence numbers from the NIOSH Registry of Toxic Effects of Chemical Substances, 1977 Edition, if available. The data sheets were developed and compiled to aid in apprising the employees of hazards peculiar to the handling and/or use of specific toxic chemicals. Space limitation necessitate the use of descriptive medical terms and toxicological abbreviations. A glossary and an abbreviation list were developed to define some of those sometimes unfamiliar terms and abbreviations. The page numbers are keyed to the catalog number in the chemical stores at ORNL.

COLLABORATIVE TRIAL AND QUALITY CONTROL IN CHEMICAL ANALYSIS

Directory of Open Access Journals (Sweden)

Narsito Narsito

2010-06-01

Full Text Available Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of analytical method, quality assurance in chemical analysis. The assessment of quality parameter for analytical method like the use of standard materials as well as standard methods is given. Concerning with the quality control of analytical data, the use of several techniques, such as control samples and control charts, in monitoring analytical data in quality control program are described qualitatively.  In the final part of this paper, some important remarks for the preparation of collaborative trials, including the evaluation of accuracy and reproducibility of analytical method are also given Keywords: collaborative trials, quality control, analytical data Abstract                                                             This paper deals with some practical problems related to the quality of analytical chemical data usually met in practice. Special attention is given to the topic of quality control in analytical chemistry, since analytical data is one of the primary information from which some important scientifically based decision are to be made. The present paper starts with brief description on some fundamental aspects associated with quality of analytical data, such as sources of variation of analytical data, criteria for quality of

The Synergistic Effect between Electrical and Chemical Factors in Plasma Gene/Molecule-Transfection

Science.gov (United States)

Jinno, Masafumi

2016-09-01

This study has been done to know what kind of factors in plasma and processes on cells promote plasma gene/molecule transfection. We have discovered a new plasma source using a microcapillary electrode which enables high transfection efficiency and high cell survivability simultaneously. However, the mechanism of the transfection by plasma was not clear. To clarify the transfection mechanisms by micro plasma, we focused on the effects of electrical (current, charge, field, etc.) and chemical (radicals, RONS, etc.) factors generated by the micro plasma and evaluated the contribution weight of three groups of the effects and processes, i.e. electrical, chemical and biochemical ones. At first, the necessity of the electrical factors was estimated by the laser produced plasma (LPP). Mouse L-929 fibroblast cell was cultured on a 96-well plate or 12-well micro slide chamber. Plasmids pCX-EGFP in Tris-EDTA buffer was dropped on the cells and they were exposed to the capillary discharge plasma (CDP) or the LPP. In the case of the CDP, the plasma was generated between the tip of the capillary electrode and the cells so that both electrical and chemical factors were supplied to the cells. In this setup, about 20% of average transfection efficiency was obtained. In the case of the LPP, the plasma was generated apart from the cells so that electrical factors were not supplied to the cells. In this setup, no transfection was observed. These results show that the electrical factors are necessary for the plasma gene transfection. Next, the necessity of the chemical factors was estimated the effect of catalase to remove H2O2 in CDP. The transfection efficiency decreased to 0.4 by scavenging H2O2 with catalase. However, only the solution of H2O2 caused no gene transfection in cells. These results shows that H2O2 is important species to cause gene/molecule transfection but still needs a synergistic effect with electrical or other chemical factors. This work was partly supported by

In silico models for predicting vector control chemicals targeting Aedes aegypti

Science.gov (United States)

Devillers, J.; Lagneau, C.; Lattes, A.; Garrigues, J.C.; Clémenté, M.M.; Yébakima, A.

2014-01-01

Human arboviral diseases have emerged or re-emerged in numerous countries worldwide due to a number of factors including the lack of progress in vaccine development, lack of drugs, insecticide resistance in mosquitoes, climate changes, societal behaviours, and economical constraints. Thus, Aedes aegypti is the main vector of the yellow fever and dengue fever flaviviruses and is also responsible for several recent outbreaks of the chikungunya alphavirus. As for the other mosquito species, the A. aegypti control relies heavily on the use of insecticides. However, because of increasing resistance to the different families of insecticides, reduction of Aedes populations is becoming increasingly difficult. Despite the unquestionable utility of insecticides in fighting mosquito populations, there are very few new insecticides developed and commercialized for vector control. This is because the high cost of the discovery of an insecticide is not counterbalanced by the ‘low profitability’ of the vector control market. Fortunately, the use of quantitative structure–activity relationship (QSAR) modelling allows the reduction of time and cost in the discovery of new chemical structures potentially active against mosquitoes. In this context, the goal of the present study was to review all the existing QSAR models on A. aegypti. The homology and pharmacophore models were also reviewed. Specific attention was paid to show the variety of targets investigated in Aedes in relation to the physiology and ecology of the mosquito as well as the diversity of the chemical structures which have been proposed, encompassing man-made and natural substances. PMID:25275884

Toxic effects of the interaction of titanium dioxide nanoparticles with chemicals or physical factors

Science.gov (United States)

Liu, Kui; Lin, Xialu; Zhao, Jinshun

2013-01-01

Due to their chemical stability and nonallergic, nonirritant, and ultraviolet protective properties, titanium dioxide (TiO2) nanoparticles (NPs) have been widely used in industries such as electronics, optics, and material sciences, as well as architecture, medicine, and pharmacology. However, increasing concerns have been raised in regards to its ecotoxicity and toxicity on the aquatic environment as well as to humans. Although insights have been gained into the effects of TiO2 NPs on susceptible biological systems, there is still much ground to be covered, particularly in respect of our knowledge of the effects of the interaction of TiO2 NPs with other chemicals or physical factors. Studies suggest that interactions of TiO2 NPs with other chemicals or physical factors may result in an increase in toxicity or adverse effects. This review highlights recent progress in the study of the interactive effects of TiO2 NPs with other chemicals or physical factors. PMID:23901269

Application of hazard analysis critical control points (HACCP) to organic chemical contaminants in food.

Science.gov (United States)

Ropkins, K; Beck, A J

2002-03-01

Hazard Analysis Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards that was developed as an effective alternative to conventional end-point analysis to control food safety. It has been described as the most effective means of controlling foodborne diseases, and its application to the control of microbiological hazards has been accepted internationally. By contrast, relatively little has been reported relating to the potential use of HACCP, or HACCP-like procedures, to control chemical contaminants of food. This article presents an overview of the implementation of HACCP and discusses its application to the control of organic chemical contaminants in the food chain. Although this is likely to result in many of the advantages previously identified for microbiological HACCP, that is, more effective, efficient, and economical hazard management, a number of areas are identified that require further research and development. These include: (1) a need to refine the methods of chemical contaminant identification and risk assessment employed, (2) develop more cost-effective monitoring and control methods for routine chemical contaminant surveillance of food, and (3) improve the effectiveness of process optimization for the control of chemical contaminants in food.

Process Control Systems in the Chemical Industry: Safety vs. Security

Energy Technology Data Exchange (ETDEWEB)

Jeffrey Hahn; Thomas Anderson

2005-04-01

Traditionally, the primary focus of the chemical industry has been safety and productivity. However, recent threats to our nation’s critical infrastructure have prompted a tightening of security measures across many different industry sectors. Reducing vulnerabilities of control systems against physical and cyber attack is necessary to ensure the safety, security and effective functioning of these systems. The U.S. Department of Homeland Security has developed a strategy to secure these vulnerabilities. Crucial to this strategy is the Control Systems Security and Test Center (CSSTC) established to test and analyze control systems equipment. In addition, the CSSTC promotes a proactive, collaborative approach to increase industry's awareness of standards, products and processes that can enhance the security of control systems. This paper outlines measures that can be taken to enhance the cybersecurity of process control systems in the chemical sector.

Health impacts of chemical irritants used for crowd control: a systematic review of the injuries and deaths caused by tear gas and pepper spray.

Science.gov (United States)

Haar, Rohini J; Iacopino, Vincent; Ranadive, Nikhil; Weiser, Sheri D; Dandu, Madhavi

2017-10-19

Chemical irritants used in crowd control, such as tear gases and pepper sprays, are generally considered to be safe and to cause only transient pain and lacrimation. However, there are numerous reports that use and misuse of these chemicals may cause serious injuries. We aimed to review documented injuries from chemical irritants to better understand the morbidity and mortality associated with these weapons. We conducted a systematic review using PRISMA guidelines to identify injuries, permanent disabilities, and deaths from chemical irritants worldwide between January 1, 1990 and March 15, 2015. We reviewed injuries to different body systems, injury severity, and potential risk factors for injury severity. We also assessed region, context and quality of each included article. We identified 31 studies from 11 countries. These reported on 5131 people who suffered injuries, two of whom died and 58 of whom suffered permanent disabilities. Out of 9261 total injuries, 8.7% were severe and required professional medical management, while 17% were moderate and 74.3% were minor. Severe injuries occurred to all body systems, with the majority of injuries impacting the skin and eyes. Projectile munition trauma caused 231 projectile injuries, with 63 (27%) severe injuries, including major head injury and vision loss. Potentiating factors for more severe injury included environmental conditions, prolonged exposure time, and higher quantities of chemical agent in enclosed spaces. Although chemical weapons may have a limited role in crowd control, our findings demonstrate that they have significant potential for misuse, leading to unnecessary morbidity and mortality. A nuanced understanding of the health impacts of chemical weapons and mitigating factors is imperative to avoiding indiscriminate use of chemical weapons and associated health consequences.

Meta-analysis of studies on chemical, physical and biological agents in the control of Aedes aegypti.

Science.gov (United States)

Lima, Estelita Pereira; Goulart, Marília Oliveira Fonseca; Rolim Neto, Modesto Leite

2015-09-04

Aedes aegypti is a vector of international concern because it can transmit to humans three important arboviral diseases: yellow fever, dengue and chikungunya. Epidemics that are repeated year after year in a variety of urban centers indicate that there are control failures, allowing the vector to continue expanding. To identify the most effective vector control strategies and the factors that contributed to the success or failure of each strategy, we carried out a systematic review with meta-analysis of articles published in 12 databases, from 1974 to the month of December 2013. We evaluated the association between the use of whatever chemical substance, mechanical agent, biological or integrated actions against A. aegypti and the control of the vector, as measured by 10 indicators. We found 2,791 articles, but after careful selection, only 26 studies remained for analysis related to control interventions implemented in 15 countries, with 5 biological, 5 chemical, 3 mechanical and 13 integrated strategies. The comparison among all of them, indicated that the control of A. aegypti is significantly associated with the type of strategy used, and that integrated interventions consist of the most effective method for controlling A. aegypti. The most effective control method was the integrated approach, considering the influence of eco-bio-social determinants in the virus-vector-man epidemiological chain, and community involvement, starting with community empowerment as active agents of vector control.

Material compatibility and corrosion control of the KWU chemical cleaning process

International Nuclear Information System (INIS)

Odar, S.

1994-01-01

The concentrations of salt impurities within the deposits on the tube sheet and in the tube to tube-support-plate crevices can induce a variety of corrosion mechanisms on steam generator tubes. One of the most effective ways of counteracting corrosion mechanisms and thus of improving steam generator performance is to clean the steam generators and keep them in a clean condition. As shown by field results chemical cleaning is a way of removing hazardous deposits from steam generators. All available chemical cleaning processes use inhibitors to control the corrosion except the KWU chemical cleaning process. In this article the corrosion control technique of KWU Chemical Cleaning Process without using conventional inhibitors will be explained and the state of the field experience with respect to material compatibility will be presented. (author). 4 figs., 1 tab., 8 refs

Q-factor control of multilayer micromembrane using PZT composite material

Science.gov (United States)

Čekas, Elingas; Janušas, Giedrius; Palevicius, Arvydas; Janušas, Tomas; Ciganas, Justas

2018-02-01

Cantilever and membrane based sensors, which are capable of providing accurate detection of target analytes have been always an important research topic of medical diagnostics, food testing, and environmental monitoring fields. Here, the mechanical detection is achieved by micro- and nano-scale cantilevers for stress sensing and mass sensing, or micro- and nano-scale plates or membranes. High sensitivity is a major issue for the active element and it could be achieved via increased Q-factor. The ability to control the Q factor expands the range of application of the device and allows to achieve more accurate results. The aim of this paper is to investigate the mechanical and electrical properties, as well as, the ability to control the Q factor of the membrane with PZT nanocomposite. This multilayered membrane was formatted using the n-type silicon substrate by implementing the Low Pressure Chemical Vapor Deposition (LPCVD), photolithography by using photomask with defined dimensions, deep etching, and e-beam evaporation techniques. Dynamic and electrical characteristics of the membrane were numerically investigated using COMSOL Multiphysics software. The use of the multilayered membrane can range from simple monitoring of particles concentration in a closed environment to inspecting glucose levels in human fluids (blood, tears, sweat, etc.).

Chemical Controls of Ozone Dry Deposition to the Sea Surface Microlayer

Science.gov (United States)

Carpenter, L.; Chance, R.; Tinel, L.; Saint, A.; Sherwen, T.; Loades, D.; Evans, M. J.; Boxhall, P.; Hamilton, J.; Stolle, C.; Wurl, O.; Ribas-Ribas, M.; Pereira, R.

2017-12-01

Oceanic dry deposition of atmospheric ozone (O3) is both the largest and most uncertain O3 depositional sink, and is widely acknowledged to be controlled largely by chemical reactions in the sea surface microlayer (SML) involving iodide (I-) and dissolved organic material (DOM). These reactions not only determine how quickly O3 can be removed from the atmosphere, but also result in emissions of trace gases including volatile organic compounds and may constitute a source of secondary organic aerosols to the marine atmosphere. Iodide concentrations at the sea surface vary by approximately an order of magnitude spatially, leading to more than fivefold variation in ozone deposition velocities (and volatile iodine fluxes). Sea-surface temperature is a reasonable predictor of [I-], however two recent parameterisations for surface I- differ by a factor of two at low latitudes. The nature and reactivity of marine DOM to O3 is almost completely unknown, although studies have suggested approximately equivalent chemical control of I- and DOM on ozone deposition. Here we present substantial new measurements of oceanic I- in both bulk seawater and the overlying SML, and show improved estimates of the global sea surface iodide distribution. We also present analyses of water-soluble DOM isolated from the SML and bulk seawater, and corresponding laboratory studies of ozone uptake to bulk and SML seawater, with the aim of characterizing the reactivity of O3 towards marine DOM.

Chemical and ecological control methods for Epitrix spp.

Directory of Open Access Journals (Sweden)

A. G. S. Cuthbertson

2015-01-01

Full Text Available Very little information exists in regards to the control options available for potato flea beetles, Epitrix spp. This short review covers both chemical and ecological options currently available for control of Epitrix spp. Synthetic pyrethroids are the weapon of choice for the beetles. However, the impetus in integrated pest management is to do timely (early-season applications with something harsh which will give long-term protection at a time when there are not a lot of beneficials in the field. Finding the balance for control of Epitrix spp. is proving difficult.

AMAZON RAINFOREST COSMETICS: CHEMICAL APPROACH FOR QUALITY CONTROL

Directory of Open Access Journals (Sweden)

Mariko Funasaki

2016-02-01

Full Text Available The market for natural cosmetics featuring ingredients derived from Amazon natural resources is growing worldwide. However, there is neither enough scientific basis nor quality control of these ingredients. This paper is an account of the chemical constituents and their biological activities of fourteen Amazonian species used in cosmetic industry, including açaí (Euterpe oleracea, andiroba (Carapa guianensis, bacuri (Platonia insignis, Brazil nut (Bertholletia excelsa, buriti (Mauritia vinifera or M. flexuosa, cumaru (Dipteryx odorata, cupuaçu (Theobroma grandiflorum, guarana (Paullinia cupana, mulateiro (Calycophyllum spruceanum, murumuru (Astrocaryum murumuru, patawa (Oenocarpus bataua or Jessenia bataua, pracaxi (Pentaclethra macroloba, rosewood (Aniba rosaeodora, and ucuuba (Virola sebifera. Based on the reviewed articles, we selected chemical markers for the quality control purpose and evaluated analytical methods. Even though chromatographic and spectroscopic methods are major analytical techniques in the studies of these species, molecular approaches will also be important as used in food and medicine traceability. Only a little phytochemical study is available about most of the Amazonian species and some species such as açaí and andiroba have many reports on chemical constituents, but studies on biological activities of isolated compounds and sampling with geographical variation are limited.

Health impacts of chemical irritants used for crowd control: a systematic review of the injuries and deaths caused by tear gas and pepper spray

Directory of Open Access Journals (Sweden)

Rohini J. Haar

2017-10-01

Full Text Available Abstract Background Chemical irritants used in crowd control, such as tear gases and pepper sprays, are generally considered to be safe and to cause only transient pain and lacrimation. However, there are numerous reports that use and misuse of these chemicals may cause serious injuries. We aimed to review documented injuries from chemical irritants to better understand the morbidity and mortality associated with these weapons. Methods We conducted a systematic review using PRISMA guidelines to identify injuries, permanent disabilities, and deaths from chemical irritants worldwide between January 1, 1990 and March 15, 2015. We reviewed injuries to different body systems, injury severity, and potential risk factors for injury severity. We also assessed region, context and quality of each included article. Results We identified 31 studies from 11 countries. These reported on 5131 people who suffered injuries, two of whom died and 58 of whom suffered permanent disabilities. Out of 9261 total injuries, 8.7% were severe and required professional medical management, while 17% were moderate and 74.3% were minor. Severe injuries occurred to all body systems, with the majority of injuries impacting the skin and eyes. Projectile munition trauma caused 231 projectile injuries, with 63 (27% severe injuries, including major head injury and vision loss. Potentiating factors for more severe injury included environmental conditions, prolonged exposure time, and higher quantities of chemical agent in enclosed spaces. Conclusions Although chemical weapons may have a limited role in crowd control, our findings demonstrate that they have significant potential for misuse, leading to unnecessary morbidity and mortality. A nuanced understanding of the health impacts of chemical weapons and mitigating factors is imperative to avoiding indiscriminate use of chemical weapons and associated health consequences.

Factors controlling metal fuel lifetime

International Nuclear Information System (INIS)

Porter, D.L.; Hofman, G.L.; Seidel, B.R.; Walters, L.C.

1986-01-01

The reliability of metal fuel elements is determined by a fuel burnup at which a statistically predicted number of fuel breaches would occur, the number of breaches determined by the amount of free fission gas which a particular reactor design can tolerate. The reliability is therefore measured using experimentally determined breach statistics, or by modelling fuel element behavior and those factors which contribute to cladding breach. The factors are fuel/cladding mechanical and chemical interactions, fission gas pressure, fuel phase transformations involving volume changes, and fission product effects on cladding integrity. Experimental data for EBR-II fuel elements has shown that the primary, and perhaps the only significant factor affecting metal fuel reliability, is the pressure-induced stresses caused by fission gas release. Other metal fuel/cladding systems may perform similarly

Chemical and molecular factors in irritable bowel syndrome: current knowledge, challenges, and unanswered questions.

Science.gov (United States)

Camilleri, Michael; Oduyebo, Ibironke; Halawi, Houssam

2016-11-01

Several chemical and molecular factors in the intestine are reported to be altered and to have a potentially significant role in irritable bowel syndrome (IBS), particularly in IBS with diarrhea. These include bile acids; short-chain fatty acids; mucosal barrier proteins; mast cell products such as histamine, proteases, and tryptase; enteroendocrine cell products; and mucosal mRNAs, proteins, and microRNAs. This article reviews the current knowledge and unanswered questions in the pathobiology of the chemical and molecular factors in IBS. Evidence continues to point to significant roles in pathogenesis of these chemical and molecular mechanisms, which may therefore constitute potential targets for future research and therapy. However, it is still necessary to address the interaction between these factors in the gut and to appraise how they may influence hypervigilance in the central nervous system in patients with IBS. Copyright © 2016 the American Physiological Society.

MIMO Self-Tuning Control of Chemical Process Operation

DEFF Research Database (Denmark)

Hallager, L.; Jørgensen, S. B.; Goldschmidt, L.

1984-01-01

The problem of selecting a feasible model structure for a MIMO self-tuning controller (MIMOSC) is addressed. The dependency of the necessary structure complexity in relation to the specific process operating point is investigated. Experimental results from a fixed-bed chemical reactor are used...

Retrofitting existing chemical scrubbers to biotrickling filters for H2S emission control.

Science.gov (United States)

Gabriel, David; Deshusses, Marc A

2003-05-27

Biological treatment is a promising alternative to conventional air-pollution control methods, but thus far biotreatment processes for odor control have always required much larger reactor volumes than chemical scrubbers. We converted an existing full-scale chemical scrubber to a biological trickling filter and showed that effective treatment of hydrogen sulfide (H2S) in the converted scrubber was possible even at gas contact times as low as 1.6 s. That is 8-20 times shorter than previous biotrickling filtration reports and comparable to usual contact times in chemical scrubbers. Significant removal of reduced sulfur compounds, ammonia, and volatile organic compounds present in traces in the air was also observed. Continuous operation for >8 months showed stable performance and robust behavior for H2S treatment, with pollutant-removal performance comparable to that achieved by using a chemical scrubber. Our study demonstrates that biotrickling filters can replace chemical scrubbers and be a safer, more economical technique for odor control.

Chemical signal activation of an organocatalyst enables control over soft material formation.

Science.gov (United States)

Trausel, Fanny; Maity, Chandan; Poolman, Jos M; Kouwenberg, D S J; Versluis, Frank; van Esch, Jan H; Eelkema, Rienk

2017-10-12

Cells can react to their environment by changing the activity of enzymes in response to specific chemical signals. Artificial catalysts capable of being activated by chemical signals are rare, but of interest for creating autonomously responsive materials. We present an organocatalyst that is activated by a chemical signal, enabling temporal control over reaction rates and the formation of materials. Using self-immolative chemistry, we design a deactivated aniline organocatalyst that is activated by the chemical signal hydrogen peroxide and catalyses hydrazone formation. Upon activation of the catalyst, the rate of hydrazone formation increases 10-fold almost instantly. The responsive organocatalyst enables temporal control over the formation of gels featuring hydrazone bonds. The generic design should enable the use of a large range of triggers and organocatalysts, and appears a promising method for the introduction of signal response in materials, constituting a first step towards achieving communication between artificial chemical systems.Enzymes regulated by chemical signals are common in biology, but few such artificial catalysts exist. Here, the authors design an aniline catalyst that, when activated by a chemical trigger, catalyses formation of hydrazone-based gels, demonstrating signal response in a soft material.

Chemical optimization algorithm for fuzzy controller design

CERN Document Server

Astudillo, Leslie; Castillo, Oscar

2014-01-01

In this book, a novel optimization method inspired by a paradigm from nature is introduced. The chemical reactions are used as a paradigm to propose an optimization method that simulates these natural processes. The proposed algorithm is described in detail and then a set of typical complex benchmark functions is used to evaluate the performance of the algorithm. Simulation results show that the proposed optimization algorithm can outperform other methods in a set of benchmark functions. This chemical reaction optimization paradigm is also applied to solve the tracking problem for the dynamic model of a unicycle mobile robot by integrating a kinematic and a torque controller based on fuzzy logic theory. Computer simulations are presented confirming that this optimization paradigm is able to outperform other optimization techniques applied to this particular robot application

Diameter control and emission properties of carbon nanotubes grown using chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Kaatz, F.H.; Siegal, M.P.; Overmyer, D.L.; Provencio, P.P.; Jackson, J.L

2003-01-15

We grow multiwalled carbon nanotubes (CNTs) via thermal chemical vapor deposition from a sputtered 4-nm-thick nickel catalyst film on a tungsten-coated silicon substrate. CNTs grow from a mixture of nitrogen and acetylene gases at temperatures ranging from 630 to 790 deg. C, resulting in CNT outer diameters of 5-350 nm. CNT diameters increase exponentially with temperature. These results define regimes for template growth fabricated in catalytically active anodized aluminum oxide (AAO) with controlled pinhole sizes ranging from 10 to 50 nm. We measure a threshold electron emission field of 3 V/{mu}m and a field enhancement factor {beta}=5230 on randomly oriented 10-nm diameter CNTs.

Diameter control and emission properties of carbon nanotubes grown using chemical vapor deposition

International Nuclear Information System (INIS)

Kaatz, F.H.; Siegal, M.P.; Overmyer, D.L.; Provencio, P.P.; Jackson, J.L.

2003-01-01

We grow multiwalled carbon nanotubes (CNTs) via thermal chemical vapor deposition from a sputtered 4-nm-thick nickel catalyst film on a tungsten-coated silicon substrate. CNTs grow from a mixture of nitrogen and acetylene gases at temperatures ranging from 630 to 790 deg. C, resulting in CNT outer diameters of 5-350 nm. CNT diameters increase exponentially with temperature. These results define regimes for template growth fabricated in catalytically active anodized aluminum oxide (AAO) with controlled pinhole sizes ranging from 10 to 50 nm. We measure a threshold electron emission field of 3 V/μm and a field enhancement factor β=5230 on randomly oriented 10-nm diameter CNTs

Soft Sensors: Chemoinformatic Model for Efficient Control and Operation in Chemical Plants.

Science.gov (United States)

Funatsu, Kimito

2016-12-01

Soft sensor is statistical model as an essential tool for controlling pharmaceutical, chemical and industrial plants. I introduce soft sensor, the roles, the applications, the problems and the research examples such as adaptive soft sensor, database monitoring and efficient process control. The use of soft sensor enables chemical industrial plants to be operated more effectively and stably. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physical chemical quality control of the molybdenum technetium generator

International Nuclear Information System (INIS)

Olive, E.; Cruz, J.; Isaac, M.; Gamboa, R.; D'Alessandro, K.; Desdin, L.F.

1995-01-01

Comparative operational procedure imported molybdenum technetium generators have been made. Procedures for determination of chemical, radiochemical and radionuclidic purities that may be applied in Hospital's laboratories and in the quality control of generators production are developed

Economic model predictive control theory, formulations and chemical process applications

CERN Document Server

Ellis, Matthew; Christofides, Panagiotis D

2017-01-01

This book presents general methods for the design of economic model predictive control (EMPC) systems for broad classes of nonlinear systems that address key theoretical and practical considerations including recursive feasibility, closed-loop stability, closed-loop performance, and computational efficiency. Specifically, the book proposes: Lyapunov-based EMPC methods for nonlinear systems; two-tier EMPC architectures that are highly computationally efficient; and EMPC schemes handling explicitly uncertainty, time-varying cost functions, time-delays and multiple-time-scale dynamics. The proposed methods employ a variety of tools ranging from nonlinear systems analysis, through Lyapunov-based control techniques to nonlinear dynamic optimization. The applicability and performance of the proposed methods are demonstrated through a number of chemical process examples. The book presents state-of-the-art methods for the design of economic model predictive control systems for chemical processes. In addition to being...

Factors associated with chemical burns in Zhejiang province, China: An epidemiological study

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Jiang Rui M

2011-09-01

Full Text Available Abstract Background Work-related burns are common among occupational injuries. Zhejiang Province is an industrial area with a high incidence of chemical burns. We aimed to survey epidemiological features of chemical burns in Zhejiang province to determine associated factors and acquire data for developing a strategy to prevent and treat chemical burns. Methods Questionnaires were developed, reviewed and validated by experts, and sent to 25 hospitals in Zhejiang province to prospectively collect data of 492 chemical burn patients admitted during one year from Sept. 1, 2008 to Aug. 31, 2009. Questions included victims' characteristics and general condition, injury location, causes of accident, causative chemicals, total body surface area burn, concomitant injuries, employee safety training, and awareness level of protective measures. Surveys were completed for each of burn patients by burn department personnel who interviewed the hospitalized patients. Results In this study, 417 victims (87.61% got chemical burn at work, of which 355 victims (74.58% worked in private or individual enterprises. Most frequent chemicals involved were hydrofluoric acid and sulfuric acid. Main causes of chemical injury accidents were inappropriate operation of equipment or handling of chemicals and absence of or failure to use effective individual protection. Conclusions Most chemical burns are preventable occupational injuries that can be attributed to inappropriate operation of equipment or handling of chemicals, lack of employee awareness about appropriate action and lack of effective protective equipment and training. Emphasis on safety education and protection for workers may help protect workers and prevent chemical burns.

Chemical and physical quality control of the HIPPURAN-131I

International Nuclear Information System (INIS)

Morin Zorilla, J.; Olive, E.; Isaac, M.; Cruz, J.

1989-01-01

Some physico-chemical methods for analytical control of Hippuran- 131 I are compared. The most convenient to applicate in hospitals and in more specialized quality control laboratories are recommended. The quality of Hippuran- 131 I produced by ISOTOP (USSR) is also evaluated. The product met the requirement of the International Pharmacopeia

Motivational Factors Contributing to Turkish High School Students' Achievement in Gases and Chemical Reactions

Science.gov (United States)

Kadioglu, Cansel; Uzuntiryaki, Esen

2008-01-01

This study aimed to investigate the contribution of motivational factors to 10th grade students' achievement in gases and chemical reactions in chemistry. Three hundred fifty nine 10th grade students participated in the study. The Gases and Chemical Reactions Achievement Test and the Motivated Strategies for Learning Questionnaire were…

PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

Energy Technology Data Exchange (ETDEWEB)

Mukul Sharma; Steven Bryant; Chun Huh

2008-03-31

There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and

Analysis of chemical factors affecting marine ecosystem around nuclear power plant

International Nuclear Information System (INIS)

Chun, Kwan Sik; Choi, Yoon Dong; Chun, Ki Jeong; Kim, Jin Kyu; Jung, Kyeong Chai; Lee, Yeong Keun; Park, Hyo Kook

1994-06-01

The ecological data of the coastal area of Youngkwang nuclear power plant from 1987 to 1993 were comprehensively analyzed, and various physical and chemical properties of sea water and sediments were measured. Major factors affecting phytoplankton standing crops were suspended substances, nitrate, and silicate. The contents of iron, chromium, copper, and sulfur in sediments sampled from the discharge channel were slightly higher than those in the other areas. In order to qantify the chemical impacts on marine ecosystem, it is desirable that a systematic survey be made through the whole year cycle to assure the consistency and confidence of the related data. (Author)

Chemical factors of soil polution in Taganrog as population health risk factors

Directory of Open Access Journals (Sweden)

G.T. Aydinov

2017-03-01

Full Text Available Our research goal was to perform a hygienic assessment of soil pollution with chemicals on areas aimed for housing and recreation zones in Taganrog, Rostov region. Due to the fact that surface layer of city soils is an open dynamic system which is tightly connected to atmosphere and hydrosphere we treated pollutants content in soils as indicators of territory anthropogenic transformation and technogenic load on population. We used atomic-adsorption spectrophotometry to detect heavy metals and highly efficient liquid chromatography to detect 3,4-benzpyrene content. The results comprise 660 examined soil samples taken from 19 monitoring points; they were examined to detect 7 pollutants content (lead, zinc, copper, nickel, cadmium, chromium, and mercury over 2008–2015; 144 samples were examined to detect 3,4-benzpyrene content over 2013–2015. We determined that priority pollutants among detected metals were zinc and lead; their content in city soils amounted up to 5.91 and 1.95 maximum permissible concentration. Complex indicator of city soils contamination varied from 1.61 to 2.02, long-term average annual value being 1.83. 3,4-benzpyrene was confirmed to be a substantial risk factor for population health as its concentrations exceeded maximum allowable values in 65.28 % of examined soil samples at average and maximum concentrations (2.45 and 38.05 MPC correspondingly. We recommend to include this chemical into systematic environmental quality monitoring. We detected regional peculiarities of soil pollution with chemicals on city territories aimed for housing, territories of pre-school children facilities, and recreation zones.

Serum Transforming Growth Factor Beta-1 as an Index of Chemical Hepato carcinogenesis in Rats

International Nuclear Information System (INIS)

Abdelgawad, M.R.; Fekry, A.E.; Edrees, G.; Ali, M.A.; Ghareeb, N.A.

2008-01-01

Transforming growth factor beta-1 (TGF β1) is an important mediator which controls liver cell proliferation and replication. The relation between TGF β1, Alpha-fetoprotein (AFP) and clinically thought hepatocellular carcinoma (HCC) in rats were investigated to clarify the clinical value of measuring peripheral serum TGF β1 and AFP in evaluation of HCC. Peripheral serum TGF β1 and AFP were measured during chemically induced hepato carcinogenesis. Male rats were given a genotoxic compound diethylnitrosamine (DEN) in drinking water for 149 days with control receiving drinking water only. Animals were killed at different times intervals 54, 86 and 149 days, serum TGF β1 levels were measured by, Enzyme Linked Immunosorbent Assay (ELISA) and AFP levels were assayed by immunoradiometric assay (IRMA). In DEN treated rats 54 days, there was mild portal tract inflammatory cellular infiltrate, serum TGF β1 and AFP levels were both significantly elevated above control (P>0.05 and P<0.001). At 86 days there were moderate inflammation (portal and peri portal), serum TGF β1 and AFP levels were significantly increased, (P<0.001). At 149 days typical HCC were present in ten of ten rats and serum TGF β1 and AFP were both significantly elevated compared with controls, (P<0.001). It can be concluded that serum TGF β1 and AFP levels are elevated during chemically induced HCC and have roles during the stages of process (initiation, promotion and progression); both serum TGF β1 and AFP levels can be used in parallel as a non invasive tumor markers for early diagnosis and prognosis of HCC

Chemical elements in pearl oysters (Paxyodon ponderosus), phytoplankton and estuarine sediments from eastern Amazon (Northern Brazil): Bioaccumulation factors and trophic transfer factors

Science.gov (United States)

Vilhena, Maria P. S. P.; Costa, Marcondes L.; Berrêdo, José F.; Paiva, Rosildo S.; Souza, Crisvaldo C. S.

2016-04-01

The current study was conducted near Barcarena County, which is a mid-sized urban center where aluminum ore processing industries (bauxite) and Vila do Conde cargo terminal are located. It aims to discuss the bioaccumulation factors as well as factors related to the trophic transfer of chemical elements in water, oyster, phytoplankton and bottom sediments from an estuary in the Brazilian Northern coast. The bioaccumulation factor (BAF), trophic transfer factor (TTF) and biota-sediment-water were used to correlate the contents of chemical elements found in organisms. The sediment, surface water, phytoplankton and pearl oysters chemical composition was analyzed by ICP-OES and ICP-MS. Pearl oysters showed K, Ca, Mg, P, Mn, Fe, Zn, Al, Ba and Pb accumulation, which concentration increase is associated with their diet (phytoplankton). Al concentrations are 14 times higher in pearl oysters (Paxyodon ponderosus), assuming that they are associated with wastewater emissions and with industrialization processes in the area. BAF and BSAF values are 1000 times higher than the metal concentrations in water and bioavailable fraction concentrations. The oyster-phytoplankton trophic transfer factor indicates that P, Ba, Ca, Na, Cd and Zn showed the largest transfers (from 5 to 19). These trophic transfers may be sufficient to cause significant ecotoxicological effects on the region biota.

Chemical weathering as a mechanism for the climatic control of bedrock river incision

Science.gov (United States)

Murphy, Brendan P.; Johnson, Joel P. L.; Gasparini, Nicole M.; Sklar, Leonard S.

2016-04-01

Feedbacks between climate, erosion and tectonics influence the rates of chemical weathering reactions, which can consume atmospheric CO2 and modulate global climate. However, quantitative predictions for the coupling of these feedbacks are limited because the specific mechanisms by which climate controls erosion are poorly understood. Here we show that climate-dependent chemical weathering controls the erodibility of bedrock-floored rivers across a rainfall gradient on the Big Island of Hawai‘i. Field data demonstrate that the physical strength of bedrock in streambeds varies with the degree of chemical weathering, which increases systematically with local rainfall rate. We find that incorporating the quantified relationships between local rainfall and erodibility into a commonly used river incision model is necessary to predict the rates and patterns of downcutting of these rivers. In contrast to using only precipitation-dependent river discharge to explain the climatic control of bedrock river incision, the mechanism of chemical weathering can explain strong coupling between local climate and river incision.

Pulse-density modulation control of chemical oscillation far from equilibrium in a droplet open-reactor system.

Science.gov (United States)

Sugiura, Haruka; Ito, Manami; Okuaki, Tomoya; Mori, Yoshihito; Kitahata, Hiroyuki; Takinoue, Masahiro

2016-01-20

The design, construction and control of artificial self-organized systems modelled on dynamical behaviours of living systems are important issues in biologically inspired engineering. Such systems are usually based on complex reaction dynamics far from equilibrium; therefore, the control of non-equilibrium conditions is required. Here we report a droplet open-reactor system, based on droplet fusion and fission, that achieves dynamical control over chemical fluxes into/out of the reactor for chemical reactions far from equilibrium. We mathematically reveal that the control mechanism is formulated as pulse-density modulation control of the fusion-fission timing. We produce the droplet open-reactor system using microfluidic technologies and then perform external control and autonomous feedback control over autocatalytic chemical oscillation reactions far from equilibrium. We believe that this system will be valuable for the dynamical control over self-organized phenomena far from equilibrium in chemical and biomedical studies.

The Potential Of Cultural And Chemical Control Practices For ...

African Journals Online (AJOL)

The Potential Of Cultural And Chemical Control Practices For Enhancing ... and a significant (P < 0.05) increase in yield components of hands per bunch and finger ... Une étude de l\\'effet de la population de plantes, l\\'application des engrais, ...

The effect of biological and chemical control agents on the health status of the very early potato cultivar Rosara

Directory of Open Access Journals (Sweden)

Cwalina-Ambroziak Bożena

2015-12-01

Full Text Available The external appearance and quality of table potatoes are determined, among other factors, by the health status of the plants during the growing season. Chemical control methods are often combined with biocontrol agents to effectively fight potato pathogens. Potatoes of the very early cultivar Rosara were grown in experimental plots. The plots were located in Tomaszkowo (NE Poland, 2007-2009. The experiment involved the following treatments: 1 biological control − mycorrhizal Glomus spp. inoculum was applied to the roots, − tubers were dressed and plants were sprayed with Polyversum three times during the growing season, 2 chemical control - at two-week intervals, plants were sprayed with the following fungicides: Infinito 687.5 SC and Tanos 50 WG, Valbon 72 WG and Tanos 50 WG. In the control treatment, potato plants were not protected against pathogens. During the growing season, the severity of late blight and early blight was evaluated on a nine-point scale. The composition of fungal communities colonising potato stems was analysed. The fungistatic properties of the fungicides used in the field experiment were evaluated in an in vitro test. The symptoms of infections caused by Phytophthora infestans and Alternaria spp. were significantly reduced in the treatment which used the integrated chemical and biological control. The least diverse fungal community was isolated from fungicide-treated plants. In the in vitro test, fungicides at all analysed concentrations inhibited the linear mycelial growth of selected pathogens.

Communication: Control of chemical reactions using electric field gradients

Energy Technology Data Exchange (ETDEWEB)

Deshmukh, Shivaraj D.; Tsori, Yoav, E-mail: tsori@bgu.ac.il [Department of Chemical Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)

2016-05-21

We examine theoretically a new idea for spatial and temporal control of chemical reactions. When chemical reactions take place in a mixture of solvents, an external electric field can alter the local mixture composition, thereby accelerating or decelerating the rate of reaction. The spatial distribution of electric field strength can be non-trivial and depends on the arrangement of the electrodes producing it. In the absence of electric field, the mixture is homogeneous and the reaction takes place uniformly in the reactor volume. When an electric field is applied, the solvents separate and the reactants are concentrated in the same phase or separate to different phases, depending on their relative miscibility in the solvents, and this can have a large effect on the kinetics of the reaction. This method could provide an alternative way to control runaway reactions and to increase the reaction rate without using catalysts.

Communication: Control of chemical reactions using electric field gradients.

Science.gov (United States)

Deshmukh, Shivaraj D; Tsori, Yoav

2016-05-21

We examine theoretically a new idea for spatial and temporal control of chemical reactions. When chemical reactions take place in a mixture of solvents, an external electric field can alter the local mixture composition, thereby accelerating or decelerating the rate of reaction. The spatial distribution of electric field strength can be non-trivial and depends on the arrangement of the electrodes producing it. In the absence of electric field, the mixture is homogeneous and the reaction takes place uniformly in the reactor volume. When an electric field is applied, the solvents separate and the reactants are concentrated in the same phase or separate to different phases, depending on their relative miscibility in the solvents, and this can have a large effect on the kinetics of the reaction. This method could provide an alternative way to control runaway reactions and to increase the reaction rate without using catalysts.

The chemical monitoring and control during temporary turbine trip or reactor scram of nuclear power plant

International Nuclear Information System (INIS)

Liu Heng

2012-01-01

During normal operation, a malfunction of equipment or improper operation sometimes results in a turbine trip or reactor scram or even cold shutdown. Because present chemical control strategy and programs aimed at the situation of normal operation and planed refueling outage, no integrate emergency program of radiochemical and chemical control had been developed to focus on this urgent and unexpected situation. After many years of practice and experience feedback, chemists have created an emergency collaborative program of radiochemical and chemical control which aims at these unexpected situations such as unplanned unit down power, turbine trip, or reactor scram. The program defines different radiochemical and chemical control measures and steps during different status to monitor primary loop dose rate variation, fuel assembly integrity and water chemical excursion to prevent components from corrosion. (author)

Sensitivity of men and women to effect of chemical factors

Energy Technology Data Exchange (ETDEWEB)

Aliyev, V.A.

1985-05-01

The activity of enzymes performing energy metabolism and electron transport in the respiratory chain and anabolism and catabolism processes in cells of the blood system of men and women petroleum processing workers is described and discussed. Enzymic activity was studied by cytochemical methods. Subjects included basic petroleum processing device operators (96 women and 74 men ranging in age from 19-30 years with work experience ranging from 4 months to 10 years). The control group included 133 persons of corresponding age-sex groups who were not involved in petroleum processing work. The cytoenzymic studies refuted the assumption that women workers are more sensitive than men workers to the effect of toxic substances. On the whole, the men in the study were found to be less resistant to the effect of chemical factors encountered in petroleum processing work. It was assumed that specific features of functioning of the female body (menstruation, pregnancy and birth), causing stress and reconstruction of homeostasis systems, promoted improvement of adaptational mechanisms in the process of evolution, which mechanisms were coded in the gene pool. It is speculated that sexual differences may cause differences in cell metabolism. 12 refs.

Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control

Science.gov (United States)

Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

2016-01-01

Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature. PMID:27571209

Integrated Microfluidic Membrane Transistor Utilizing Chemical Information for On-Chip Flow Control.

Science.gov (United States)

Frank, Philipp; Schreiter, Joerg; Haefner, Sebastian; Paschew, Georgi; Voigt, Andreas; Richter, Andreas

2016-01-01

Microfluidics is a great enabling technology for biology, biotechnology, chemistry and general life sciences. Despite many promising predictions of its progress, microfluidics has not reached its full potential yet. To unleash this potential, we propose the use of intrinsically active hydrogels, which work as sensors and actuators at the same time, in microfluidic channel networks. These materials transfer a chemical input signal such as a substance concentration into a mechanical output. This way chemical information is processed and analyzed on the spot without the need for an external control unit. Inspired by the development electronics, our approach focuses on the development of single transistor-like components, which have the potential to be used in an integrated circuit technology. Here, we present membrane isolated chemical volume phase transition transistor (MIS-CVPT). The device is characterized in terms of the flow rate from source to drain, depending on the chemical concentration in the control channel, the source-drain pressure drop and the operating temperature.

Nonlinear model predictive control for chemical looping process

Science.gov (United States)

Joshi, Abhinaya; Lei, Hao; Lou, Xinsheng

2017-08-22

A control system for optimizing a chemical looping ("CL") plant includes a reduced order mathematical model ("ROM") that is designed by eliminating mathematical terms that have minimal effect on the outcome. A non-linear optimizer provides various inputs to the ROM and monitors the outputs to determine the optimum inputs that are then provided to the CL plant. An estimator estimates the values of various internal state variables of the CL plant. The system has one structure adapted to control a CL plant that only provides pressure measurements in the CL loops A and B, a second structure adapted to a CL plant that provides pressure measurements and solid levels in both loops A, and B, and a third structure adapted to control a CL plant that provides full information on internal state variables. A final structure provides a neural network NMPC controller to control operation of loops A and B.

MEANS OF CHEMICAL RECONNAISSANCE AND CONTROL IN THE FIGHT AGAINST CBRN TERRORISM

Directory of Open Access Journals (Sweden)

Dušan VIČAR

2013-01-01

Full Text Available The chemical, biological, radiological and nuclear terrorism (CBRN terrorism is a special form of terrorism known for its extraordinary efficiency as superterrorism or ultra-terrorism. Detection and identification of the presence of hazardous chemical toxic substances is very difficult and can be achieved only by using advanced detection and monitoring instruments and devices that are currently only in the equipment of units of the Fire and Rescue Service of the Czech Republic and some units of the chemical troops of the Czech Army. Instigators of chemical terrorism count on the surprise factor, as well as on the difficulty and great delay in detecting the presence of hazardous chemical toxic substances. Therefore, for early warning of the population and minimization of consequences of a terrorist attack with the use of hazardous chemicals, the ability of early detection and subsequent identification is very important.

Biological effects of concomitant influence of radioactive and chemical factors. (Experimental research)

International Nuclear Information System (INIS)

Meshkov, N.A.

1995-01-01

Remote consequences of concomitant influence of radioactive and chemical hazards substances, modeling the ecological situation at the territory of the Altaj region after the nuclear tests at the Semipalatinsk test site is studied on the mice. Negative effect of the concomitant impact of radioactive and hazardous chemical substances on the basic morpho-functional systems of animals is revealed; the reproduction function proved to be the most sensitive one. It is noted that the radiation factor constitutes the basis of all violations of bone marrow blood-producing function by concomitant influence

Human factors methods for nuclear control room design. Volume I. Human factors enhancement of existing nuclear control rooms. Final report

International Nuclear Information System (INIS)

Seminara, J.L.; Seidenstein, S.; Eckert, S.K.; Smith, D.L.

1979-11-01

Human factors engineering is an interdisciplinary specialty concerned with influencing the design of equipment systems, facilities, and operational environments to promote safe, efficient, and reliable operator performance. Human factors approaches were applied in the design of representative nuclear power plant control panels. First, methods for upgrading existing operational control panels were examined. Then, based on detailed human factors analyses of operator information and control requirements, designs of reactor, feedwater, and turbine-generator control panels were developed to improve the operator-control board interface, thereby reducing the potential for operator errors. In addition to examining present-generation concepts, human factors aspects of advanced systems and of hybrid combinations of advanced and conventional designs were investigated. Special attention was given to warning system designs. Also, a survey was conducted among control board designers to (1) develop an overview of design practices in the industry, and (2) establish appropriate measures leading to a more systematic concern for human factors in control board design

Chemical control of blossom blight disease of sarpagandha caused ...

African Journals Online (AJOL)

ONOS

2010-09-20

Sep 20, 2010 ... Chemical control of blossom blight disease of sarpagandha caused by Colletotrichum capsici. R. S. Shukla, Abdul-Khaliq and M. Alam*. Department of Plant Pathology, Central Institute of Medicinal and Aromatic Plants, Council of Scientific and Industrial. Research, P. O. CIMAP, Lucknow–226 015, India.

Chemical Weed Control Increases Survival and Growth in Hardwood Plantings

Science.gov (United States)

Gayne G. Erdmann

1967-01-01

In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond...

Sequence correction of random coil chemical shifts: correlation between neighbor correction factors and changes in the Ramachandran distribution

DEFF Research Database (Denmark)

Kjærgaard, Magnus; Poulsen, Flemming Martin

2011-01-01

Random coil chemical shifts are necessary for secondary chemical shift analysis, which is the main NMR method for identification of secondary structure in proteins. One of the largest challenges in the determination of random coil chemical shifts is accounting for the effect of neighboring residues....... The contributions from the neighboring residues are typically removed by using neighbor correction factors determined based on each residue's effect on glycine chemical shifts. Due to its unusual conformational freedom, glycine may be particularly unrepresentative for the remaining residue types. In this study, we...... in the conformational ensemble are an important source of neighbor effects in disordered proteins. Glutamine derived random coil chemical shifts and correction factors modestly improve our ability to predict (13)C chemical shifts of intrinsically disordered proteins compared to existing datasets, and may thus improve...

Size-controlled synthesis of transition metal nanoparticles through chemical and photo-chemical routes

Science.gov (United States)

Tangeysh, Behzad

The central objective of this work is developing convenient general procedures for controlling the formation and stabilization of nanoscale transition metal particles. Contemporary interest in developing alternative synthetic approaches for producing nanoparticles arises in large part from expanding applications of the nanomaterials in areas such as catalysis, electronics and medicine. This research focuses on advancing the existing nanoparticle synthetic routes by using a new class of polymer colloid materials as a chemical approach, and the laser irradiation of metal salt solution as a photo-chemical method to attain size and shape selectivity. Controlled synthesis of small metal nanoparticles with sizes ranging from 1 to 5nm is still a continuing challenge in nanomaterial synthesis. This research utilizes a new class of polymer colloid materials as nano-reactors and protective agents for controlling the formation of small transition metal nanoparticles. The polymer colloid particles were formed from cross-linking of dinegatively charged metal precursors with partially protonated poly dimethylaminoethylmethacrylate (PDMAEMA). Incorporation of [PtCl6]2- species into the colloidal particles prior to the chemical reduction was effectively employed as a new strategy for synthesis of unusually small platinum nanoparticles with narrow size distributions (1.12 +/-0.25nm). To explore the generality of this approach, in a series of proof-of-concept studies, this method was successfully employed for the synthesis of small palladium (1.4 +/-0.2nm) and copper nanoparticles (1.5 +/-0.6nm). The polymer colloid materials developed in this research are pH responsive, and are designed to self-assemble and/or disassemble by varying the levels of protonation of the polymer chains. This unique feature was used to tune the size of palladium nanoparticles in a small range from 1nm to 5nm. The procedure presented in this work is a new convenient room temperature route for synthesis of

Odor and odorous chemical emissions from animal buildings: part 1 - project overview, collection methods, and quality control

Science.gov (United States)

Livestock facilities have historically generated public concerns due to their emissions of odorous air and various chemical pollutants. Odor emission factors and identification of principal odorous chemicals are needed to better understand the problem. Applications of odor emission factors include i...

Maternal Chemical and Drug Intolerances: Potential Risk Factors for Autism and Attention Deficit Hyperactivity Disorder (ADHD).

Science.gov (United States)

Heilbrun, Lynne P; Palmer, Raymond F; Jaen, Carlos R; Svoboda, Melissa D; Perkins, Jimmy; Miller, Claudia S

2015-01-01

The aim of this study was to assess whether chemically intolerant women are at greater risk for having a child with autism spectrum disorders (ASD) or attention deficit hyperactivity disorder (ADHD). We conducted a case-control study of chemical intolerance among mothers of children with ASD (n = 282) or ADHD (n = 258) and children without these disorders (n = 154). Mothers participated in an online survey consisting of a validated chemical intolerance screening instrument, the Quick Environmental Exposure and Sensitivity Inventory (QEESI). Cases and controls were characterized by parental report of a professional diagnosis. We used a one-way, unbalanced analysis of variance to compare means across the 3 groups. Both mothers of children with ASD or ADHD had significantly higher mean chemical intolerance scores than did mothers of controls, and they were more likely to report adverse reactions to drugs. Chemically intolerant mothers were 3 times more likely (odds ratio, 3.01; 95% confidence interval, 1.50-6.02) to report having a child with autism or 2.3 times more likely (odds ratio, 2.3; 95% confidence interval, 1.12-5.04) to report a child with ADHD. Relative to controls, these mothers report their children are more prone to allergies (P Family Medicine.

How to control chemical hazards

CERN Multimedia

2012-01-01

Improving protection against chemical hazards is one of the 2012 CERN safety objectives identified by the Director General. Identifying and drawing up a complete inventory of chemicals, and assessing the associated risks are important steps in this direction.   The HSE Unit has drawn up safety rules, guidelines and forms to help you to meet this objective. We would like to draw your attention to: • safety guidelines C-0-0-1 and C-1-0-2 (now also available in French), which deal with the identification of hazardous chemicals and the assessment of chemical risk; • safety guideline C-1-0-1, which deals with the storage of hazardous chemicals. All safety documents can be consulted at: cern.ch/regles-securite The HSE Unit will be happy to answer any questions you may have. Write to us at: safety-general@cern.ch The HSE Unit

Application of Chemically Accelerated Biotreatment to Reduce Risk in Oil-Impacted Soils

Energy Technology Data Exchange (ETDEWEB)

Paterek, J.R.; Bogan, W.W.; Sirivedhin; Tanita

2003-03-06

Research was conducted in six major focus areas: (1) Evaluation of the process using 6 test soils with full chemical and physical characteristics to determine controlling factors for biodegradation and chemical oxidation; (2) Determination of the sequestration time on chemical treatment suspectability; (3) Risk factors, i.e. toxicity after chemical and biological treatment; (4) Impact of chemical treatment (Fenton's Reagent) on the agents of biodegradation; (5) Description of a new genus and its type species that degrades hydrocarbons; and (6) Intermediates generate from Fenton's reagent treatment of various polynuclear aromatic hydrocarbons.

Effective chemical control of fruit flies (Diptera: Tephritidae) pests in ...

African Journals Online (AJOL)

Effective chemical control of fruit flies (Diptera: Tephritidae) pests in mango orchards in northern Côte-d'Ivoire. OR N'depo, N Hala, A N'da Adopo, F Coulibaly, PK Kouassi, JF Vayssieres, M de Meyer ...

Accessible protocol for practice classroom about physical and chemical factors that affect the biomembranes integrity

Directory of Open Access Journals (Sweden)

Thiago Barros Galvão

2012-12-01

Full Text Available The aim of the current work is to review a protocol used in practical classes to demonstrate some factors that affect biomembrane integrity. Sugar-beet fragments were utilized as the experimental model as membrane damage could be visualized by leakage of betacyanins, hydrophilic pigments accumulated in the cell vacuoles. The tests were carried out as discrete experiments utilizing physical agents and chemical products present in the student daily routine. To test the effect of temperature, sugar-beet fragments were submitted to heat, cold or both at different times of exposition. When chemical products were tested, sugar-beet fragments were exposed to organic solvents (common alcohol and acetone or polar and amphipathic substances (disinfectant, detergent, hydrogen peroxide, and sodium hypochlorite. The obtained results were discussed in terms of the capacity of the physical and chemical factors to cause membrane damage. The review of this protocol using reagents that are present in the student daily routine were able to demonstrate clearly the effect of the different tested factors, allowing the utilization of this practical class under limited conditions.

Role of the Slug Transcription Factor in Chemically-Induced Skin Cancer

Directory of Open Access Journals (Sweden)

Kristine von Maltzan

2016-02-01

Full Text Available The Slug transcription factor plays an important role in ultraviolet radiation (UVR-induced skin carcinogenesis, particularly in the epithelial-mesenchymal transition (EMT occurring during tumor progression. In the present studies, we investigated the role of Slug in two-stage chemical skin carcinogenesis. Slug and the related transcription factor Snail were expressed at high levels in skin tumors induced by 7,12-dimethylbenz[α]anthracene application followed by 12-O-tetradecanoylphorbol-13-acetate (TPA treatment. TPA-induced transient elevation of Slug and Snail proteins in normal mouse epidermis and studies in Slug transgenic mice indicated that Slug modulates TPA-induced epidermal hyperplasia and cutaneous inflammation. Although Snail family factors have been linked to inflammation via interactions with the cyclooxygenase-2 (COX-2 pathway, a pathway that also plays an important role in skin carcinogenesis, transient TPA induction of Slug and Snail appeared unrelated to COX-2 expression. In cultured human keratinocytes, TPA induced Snail mRNA expression while suppressing Slug expression, and this differential regulation was due specifically to activation of the TPA receptor. These studies show that Slug and Snail exhibit similar patterns of expression during both UVR and chemical skin carcinogenesis, that Slug and Snail can be differentially regulated under some conditions and that in vitro findings may not recapitulate in vivo results.

Factors influencing the profitability of optimizing control systems

International Nuclear Information System (INIS)

Broussaud, A.; Guyot, O.

1999-01-01

Optimizing control systems supplement conventional Distributed Control Systems and Programmable Logic Controllers. They continuously implement set points, which aim at maximizing the profitability of plant operation. They are becoming an integral part of modern mineral processing plants. This trend is justified by economic considerations, optimizing control being among the most cost-effective methods of improving metallurgical plant performance. The paper successively analyzes three sets of factors, which influence the profitability of optimizing control systems, and provides guidelines for analyzing the potential value of an optimizing control system at a given operation: external factors, such as economic factors and factors related to plant feed; features of the optimizing control system; and subsequent maintenance of the optimizing control system. It is shown that pay back times for optimization control projects are typically measured in days. The OCS software used by the authors for their applications is described briefly. (author)

Human factors methods for nuclear control room design. Volume 2. Human factors survey of control room design practices

International Nuclear Information System (INIS)

Seminara, J.L.; Parsons, S.O.

1979-11-01

An earlier review of the control rooms of operating nuclear power plants identified many design problems having potential for degrading operator performance. As a result, the formal application of human factors principles was found to be needed. This report demonstrates the use of human factors in the design of power plant control rooms. The approaches shown in the report can be applied to operating power plants, as well as to those in the design stage. This study documents human factors techniques required to provide a sustained concern for the man-machine interface from control room concept definition to system implementation

Methylene Diphosphonate Chemical and Biological control of MDP complex

International Nuclear Information System (INIS)

Aungurarat, Angkanan; Ngamprayad, Tippanan

2000-01-01

Technetium-9 9m MDP easy prepared from MDP kits which different sources such as OAP (In house), SIGMA. The resulting Tc 9 9m -MDP preparations were controlled in chemical and biological tests to compare the different results in these cases: radiochemical purity, the quantity of starting material and biodistribution result

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

Directory of Open Access Journals (Sweden)

Xiang Wang

2013-01-01

Full Text Available We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

KAUST Repository

Wang, Xiang; Li, Shunbo; Wang, Limu; Yi, Xin; Hui, Yu Sanna; Qin, Jianhua; Wen, Weijia

2013-01-01

We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

Microfluidic Device for Controllable Chemical Release via Field-Actuated Membrane Incorporating Nanoparticles

KAUST Repository

Wang, Xiang

2013-01-01

We report a robust magnetic-membrane-based microfluidic platform for controllable chemical release. The magnetic membrane was prepared by mixing polydimethylsiloxane (PDMS) and carbonyl-iron nanoparticles together to obtain a flexible thin film. With combined, simultaneous regulation of magnetic stimulus and mechanical pumping, the desired chemical release rate can easily be realized. For example, the dose release experimental data was well fitted by a mathematical sigmoidal model, exhibiting a typical dose-response relationship, which shows promise in providing significant guidance for on-demand drug delivery. To test the platform’s feasibility, our microfluidic device was employed in an experiment involving Escherichia coli culture under controlled antibiotic ciprofloxacin exposure, and the expected outcomes were successfully obtained. Our experimental results indicate that such a microfluidic device, with high accuracy and easy manipulation properties, can legitimately be characterized as active chemical release system.

78 FR 39337 - Importer of Controlled Substances, Notice of Application, Boehringer Ingelheim Chemicals

Science.gov (United States)

2013-07-01

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Importer of Controlled Substances, Notice of Application, Boehringer Ingelheim Chemicals Pursuant to Title 21 Code of Federal Regulations 1301.34(a), this is notice that on May 31, 2013, Boehringer Ingelheim Chemicals, 2820 N. Normandy Drive, Petersburg...

77 FR 43861 - Importer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals

Science.gov (United States)

2012-07-26

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Importer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals Pursuant to Title 21 Code of Federal Regulations 1301.34(a), this is notice that on June 8, 2012, Boehringer Ingelheim Chemicals, Inc., 2820 N. Normandy Drive...

Nanoscale control of reversible chemical reaction between fullerene C60 molecules using scanning tunneling microscope.

Science.gov (United States)

Nakaya, Masato; Kuwahara, Yuji; Aono, Masakazu; Nakayama, Tomonobu

2011-04-01

The nanoscale control of reversible chemical reactions, the polymerization and depolymerization between C60 molecules, has been investigated. Using a scanning tunneling microscope (STM), the polymerization and depolymerization can be controlled at designated positions in ultrathin films of C60 molecules. One of the two chemical reactions can be selectively induced by controlling the sample bias voltage (V(s)); the application of negative and positive values of V(s) results in polymerization and depolymerization, respectively. The selectivity between the two chemical reactions becomes extremely high when the thickness of the C60 film increases to more than three molecular layers. We conclude that STM-induced negative and positive electrostatic ionization are responsible for the control of the polymerization and depolymerization, respectively.

A study of the effects of physical dermabrasion combined with chemical peeling in porcine skin.

Science.gov (United States)

Kang, Boo Kyoung; Choi, Jeong Hwee; Jeong, Ki Heon; Park, Jong Min; Suh, Dong Hye; Lee, Sang Jun; Shin, Min Kyung

2015-02-01

Many comparative studies of chemical peeling and dermabrasion have been reported. However, rare basic scientific data about the immediate effects after combined treatment with chemical peeling and dermabrasion have been confirmed. The aim of this study is to evaluate the effect of the application of physical abrasion in combination with chemical peels. Three pigs were treated with physical abrasion using a water jet device in combination with an α-hydroxy acid solution, and the skin samples of the control received chemical peeling solution alone. The levels of growth factors and neuropeptides were measured with a multiplex immunoassay. Skin treated with physical dermabrasion combined with chemical peeling showed prominent detachment and swelling of the stratum corneum (SC), and fluid collection in the hair follicles. The mean cell count of CD34 positive fibroblasts and mast cells, levels of epidermal growth factor, fibroblast growth factor-2, vascular endothelial growth factor, and neurotensin, were significantly increased in the tissue treated with physical abrasion combined with a chemical peeling agent, compared to the skin in the control. We concluded that physical dermabrasion combined with chemical peeling can be more effective than chemical peeling alone, for the approach through transfollicular routes.

Worldwide estimation of river concentrations of any chemical originating from sewage-treatment plants using dilution factors.

Science.gov (United States)

Keller, Virginie D J; Williams, Richard J; Lofthouse, Caryn; Johnson, Andrew C

2014-02-01

Dilution factors are a critical component in estimating concentrations of so-called "down-the-drain" chemicals (e.g., pharmaceuticals) in rivers. The present study estimated the temporal and spatial variability of dilution factors around the world using geographically referenced data sets at 0.5° × 0.5° resolution. Domestic wastewater effluents were derived from national per capita domestic water use estimates and gridded population. Monthly and annual river flows were estimated by accumulating runoff estimates using topographically derived flow directions. National statistics, including the median and interquartile range, were generated to quantify dilution factors. Spatial variability of the dilution factor was found to be considerable; for example, there are 4 orders of magnitude in annual median dilution factor between Canada and Morocco. Temporal variability within a country can also be substantial; in India, there are up to 9 orders of magnitude between median monthly dilution factors. These national statistics provide a global picture of the temporal and spatial variability of dilution factors and, hence, of the potential exposure to down-the-drain chemicals. The present methodology has potential for a wide international community (including decision makers and pharmaceutical companies) to assess relative exposure to down-the-drain chemicals released by human pollution in rivers and, thus, target areas of potentially high risk. © 2013 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Colon cancer controls versus population controls in case-control studies of occupational risk factors

DEFF Research Database (Denmark)

Kaerlev, Linda; Lynge, Elsebeth; Sabroe, Svend

2004-01-01

are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors...... about occupational, medical and life style conditions. RESULTS: No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure...... to pesticides among colon cancer controls. CONCLUSIONS: Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming....

Comparison of childhood sexual histories in subjects with pedophilia or opiate addiction and healthy controls: is childhood sexual abuse a risk factor for addictions?

Science.gov (United States)

Cohen, Lisa J; Forman, Howard; Steinfeld, Matthew; Fradkin, Yuli; Frenda, Steven; Galynker, Igor

2010-11-01

Given the recent interest in the concept of sexual addictions, it is instructive to study subjects with pedophilia alongside chemically addicted individuals and non-addicted controls in order to help identify which factors may determine the objects of people's respective addictions, as well as any factors that may predispose people to developing an addictive disorder. In this study, we considered whether childhood sexual abuse (CSA) is a specific risk factor for pedophilia as opposed to other types of addictive disorders by comparing the childhood sexual histories of 48 pedophilic sex offenders, 25 subjects with opiate addiction in remission, and 61 healthy controls. CSA was assessed with The Sexual History Questionnaire and the Child Trauma Questionnaire (CTQ). Compared with both opiate addicted subjects and healthy controls, subjects with pedophilia were more likely to report experiencing adult sexual advances when they were children and a first sexual contact by age 13 with a partner at least 5 years older. Although both subjects with pedophilia and those with opiate addiction first had sex at a younger age than healthy controls, opiate addicted subjects, compared with healthy controls, reported neither increased reception of sexual advances as children nor increased rates of first sexual contact before age 13 with a partner at least 5 years older. Further, subjects with pedophilia but not those with opiate addiction scored significantly higher than healthy controls on the CTQ. Sexual abuse in childhood may be a specific risk factor for sexual addictions such as pedophilia but may not be a specific risk factor for chemical addictions.

Selection of chemical markers for the quality control of medicinal plants of the genus Cecropia.

Science.gov (United States)

Rivera-Mondragón, Andrés; Ortíz, Orlando O; Bijttebier, Sebastiaan; Vlietinck, Arnold; Apers, Sandra; Pieters, Luc; Caballero-George, Catherina

2017-12-01

Several Cecropia (Cecropiaceae) species are traditionally used in Latin America for the treatment of a variety of diseases including diabetes, arterial hypertension, asthma, bronchitis, anxiety, and inflammation. At present, a number of commercial products based on these plants have been introduced into the market with very little information on methods for guaranteeing their quality and safety. This work proposes potential chemical markers for the quality control of the raw materials of Cecropia obtusifolia Bertol., Cecropia peltata L., Cecropia glaziovii Snethl., Cecropia pachystachya Trécul, and Cecropia hololeuca Miq. The Herbal Chemical Marker Ranking System (Herb MaRS) developed by the National Institute of Complementary Medicine (NICM) at the University of Western Sydney was used for selecting chemical markers for the quality control of selected medicinal species of Cecropia. This review covers the period from 1982 to 2016. Chlorogenic acid, flavonoidal glycosides (orientin, isoorientin, vitexin, isovitexin, and rutin), catechin, epicatechin, procyanidins (B2, B5, and C1), steroids (β-sitosterol), and triterpenoids (α-amyrin, pomolic, tormentic and ursolic acids) were selected as chemical markers for the quality control of the leaves. It is necessary to establish comprehensive standards for guaranteeing quality, safety and efficacy of herbal drugs. The selection of adequate chemical markers for quality control purposes requires a good knowledge about the chemical composition of medicinal plants and their associated biological properties. To the best of our knowledge this review article is the first to address the identification and quantitative determination of the chemical markers for the genus Cecropia.

Chemical potential and reaction electronic flux in symmetry controlled reactions.

Science.gov (United States)

Vogt-Geisse, Stefan; Toro-Labbé, Alejandro

2016-07-15

In symmetry controlled reactions, orbital degeneracies among orbitals of different symmetries can occur along a reaction coordinate. In such case Koopmans' theorem and the finite difference approximation provide a chemical potential profile with nondifferentiable points. This results in an ill-defined reaction electronic flux (REF) profile, since it is defined as the derivative of the chemical potential with respect to the reaction coordinate. To overcome this deficiency, we propose a new way for the calculation of the chemical potential based on a many orbital approach, suitable for reactions in which symmetry is preserved. This new approach gives rise to a new descriptor: symmetry adapted chemical potential (SA-CP), which is the chemical potential corresponding to a given irreducible representation of a symmetry group. A corresponding symmetry adapted reaction electronic flux (SA-REF) is also obtained. Using this approach smooth chemical potential profiles and well defined REFs are achieved. An application of SA-CP and SA-REF is presented by studying the Cs enol-keto tautomerization of thioformic acid. Two SA-REFs are obtained, JA'(ξ) and JA'' (ξ). It is found that the tautomerization proceeds via an in-plane delocalized 3-center 4-electron O-H-S hypervalent bond which is predicted to exist only in the transition state (TS) region. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

77 FR 70188 - Manufacturer of Controlled Substances; Notice of Registration; Boehringer Ingelheim Chemicals, Inc.

Science.gov (United States)

2012-11-23

...; Notice of Registration; Boehringer Ingelheim Chemicals, Inc. By Notice dated July 17, 2012, and published in the Federal Register on July 26, 2012, 77 FR 43863, Boehringer Ingelheim Chemicals, Inc., 2820 N... has considered the factors in 21 U.S.C. 823(a) and determined that the registration of Boehringer...

Factors influencing warfarin control in Australia and Singapore.

Science.gov (United States)

Bernaitis, Nijole; Ching, Chi Keong; Teo, Siew Chong; Chen, Liping; Badrick, Tony; Davey, Andrew K; Crilly, Julia; Anoopkumar-Dukie, Shailendra

2017-09-01

Warfarin is widely used for patients with non-valvular atrial fibrillation (NVAF). Variations in warfarin control, as measured by time in therapeutic range (TTR), have been reported across different regions and ethnicities, particularly between Western and Asian countries. However, there is limited data on comparative factors influencing warfarin control in Caucasian and Asian patients. Therefore, the aim of this study was to determine warfarin control and potential factors influencing this in patients with NVAF in Australia and Singapore. Retrospective data was collected for patients receiving warfarin for January to June 2014 in Australia and Singapore. TTR was calculated for individuals with mean patient TTR used for analysis. Possible influential factors on TTR were analysed including age, gender, concurrent co-morbidities, and concurrent medication. The mean TTR was significantly higher in Australia (82%) than Singapore (58%). At both sites, chronic kidney disease significantly lowered this TTR. Further factors influencing control were anaemia and ageWarfarin control was significantly higher in Australia compared to Singapore, however chronic kidney disease reduced control at both sites. The different levels of control in these two countries, together with patient factors further reducing control may impact on anticoagulant choice in these countries with better outcomes from warfarin in Australia compared to Singapore. Copyright © 2017 Elsevier Ltd. All rights reserved.

78 FR 64210 - Extension of Review Periods Under the Toxic Substances Control Act; Certain Chemicals and...

Science.gov (United States)

2013-10-28

... Under the Toxic Substances Control Act; Certain Chemicals and Microorganisms; Premanufacture... 325 and 324110), e.g., chemical manufacturing and petroleum refineries. The North American Industrial... Agency under section 5 of the Toxic Substances Control Act (TSCA), received by EPA on or before October 1...

Soft-Starting Power-Factor Motor Controller

Science.gov (United States)

Nola, F. J.

1983-01-01

Three-phase power-factor controller with soft start is based on earlier version that does not control starting transients. Additional components serve to turn off "run" command signal and substitute gradual startup command signal during preset startup interval. Improved controller reduces large current surge that usually accompanies starting. Controller applies power smoothly, without causing motor vibrations.

Two Experiments to Approach the Boltzmann Factor: Chemical Reaction and Viscous Flow

Science.gov (United States)

Fazio, Claudio; Battaglia, Onofrio R.; Guastella, Ivan

2012-01-01

In this paper we discuss a pedagogical approach aimed at pointing out the role played by the Boltzmann factor in describing phenomena usually perceived as regulated by different mechanisms of functioning. Experimental results regarding some aspects of a chemical reaction and of the viscous flow of some liquids are analysed and described in terms…

Development of Computational Approaches for Simulation and Advanced Controls for Hybrid Combustion-Gasification Chemical Looping

Energy Technology Data Exchange (ETDEWEB)

Joshi, Abhinaya; Lou, Xinsheng; Neuschaefer, Carl; Chaudry, Majid; Quinn, Joseph

2012-07-31

This document provides the results of the project through September 2009. The Phase I project has recently been extended from September 2009 to March 2011. The project extension will begin work on Chemical Looping (CL) Prototype modeling and advanced control design exploration in preparation for a scale-up phase. The results to date include: successful development of dual loop chemical looping process models and dynamic simulation software tools, development and test of several advanced control concepts and applications for Chemical Looping transport control and investigation of several sensor concepts and establishment of two feasible sensor candidates recommended for further prototype development and controls integration. There are three sections in this summary and conclusions. Section 1 presents the project scope and objectives. Section 2 highlights the detailed accomplishments by project task area. Section 3 provides conclusions to date and recommendations for future work.

Algorithmization of problems on the personnel information support in the automatic chemical control systems at NPP

International Nuclear Information System (INIS)

Vilkov, N.Ya.; Kryukov, Yu.V.; Cheshun, A.V.

2001-01-01

When elaborating software for the standard algorithms of the information support of the efficient control (keeping) of water chemistry operation (WCO) at the NPP power units one introduces an approach when the systems of chemical control are realized as the systems of quality control of in-loop physical and chemical processes gathering force in the course of time. Elaboration of algorithms to proceed data of the operational chemical control seeks for elaboration of the statistic procedures to detect anomalies of the processes at the early stages of their development more efficient in contrast to the standard procedures of control. The introduced procedure is used in the demonstration model of the system for diagnostics of some typical reasons of violation of the first circuit WCO of WWER-1000 power units [ru

Chemical composition dependence of exposure buildup factors for some polymers

Energy Technology Data Exchange (ETDEWEB)

Singh, Tejbir [Department of Physics, S.D.D.I.E.T., Barwala, District Panchkula, Haryana 134 118 (India)], E-mail: tejbir.s@rediffmail.com; Kumar, Naresh [Department of Physics, Lovely Professional University, Phagwara 144 402 (India)], E-mail: naresh20dhiman@yahoo.com; Singh, Parjit S. [Department of Physics, Punjabi University, Patiala 147 002 (India)], E-mail: dr_parjit@hotmail.com

2009-01-15

Exposure buildup factors for some polymers such as poly-acrylo-nitrile (PAN), poly-methyl-acrylate (PMA), poly-vinyl-chloride (PVC), synthetic rubber (SR), tetra-fluro-ethylene (Teflon) have been computed using the G.P. fitting method in the energy range of 0.015-15.0 MeV, up to the penetration of 40 mean free paths (mfp). The variation of exposure buildup factors for all the selected polymers with incident photon energy at the fixed penetration depths has been studied, mainly emphasizing on chemical composition (equivalent atomic number) of the selected polymers. It has been observed that for the lower penetration depths (below 10 mfp), the exposure buildup factor decreases with the increase in equivalent atomic number of the selected polymers at all the incident photon energies. However, at the penetration depth of 10 mfp and incident photon energy above 3 MeV, the exposure buildup factor becomes almost independent of the equivalent atomic number of the selected polymers. Further, above the fixed penetration depth of 15 mfp of the selected polymers and above the incident photon energy of 3 MeV, reversal in the trend has been observed, i.e., the exposure buildup factor increases with the increase in equivalent atomic number.

Chemical composition dependence of exposure buildup factors for some polymers

International Nuclear Information System (INIS)

Singh, Tejbir; Kumar, Naresh; Singh, Parjit S.

2009-01-01

Exposure buildup factors for some polymers such as poly-acrylo-nitrile (PAN), poly-methyl-acrylate (PMA), poly-vinyl-chloride (PVC), synthetic rubber (SR), tetra-fluro-ethylene (Teflon) have been computed using the G.P. fitting method in the energy range of 0.015-15.0 MeV, up to the penetration of 40 mean free paths (mfp). The variation of exposure buildup factors for all the selected polymers with incident photon energy at the fixed penetration depths has been studied, mainly emphasizing on chemical composition (equivalent atomic number) of the selected polymers. It has been observed that for the lower penetration depths (below 10 mfp), the exposure buildup factor decreases with the increase in equivalent atomic number of the selected polymers at all the incident photon energies. However, at the penetration depth of 10 mfp and incident photon energy above 3 MeV, the exposure buildup factor becomes almost independent of the equivalent atomic number of the selected polymers. Further, above the fixed penetration depth of 15 mfp of the selected polymers and above the incident photon energy of 3 MeV, reversal in the trend has been observed, i.e., the exposure buildup factor increases with the increase in equivalent atomic number

Environment polluting conventional chemical control compared to an environmentally friendly IPM approach for control of diamondback moth, Plutella xylostella (L.), in China: a review.

Science.gov (United States)

Shakeel, Muhammad; Farooq, Muhammad; Nasim, Wajid; Akram, Waseem; Khan, Fawad Zafar Ahmad; Jaleel, Waqar; Zhu, Xun; Yin, Haichen; Li, Shuzhong; Fahad, Shah; Hussain, Saddam; Chauhan, Bhagirath Singh; Jin, Fengliang

2017-06-01

The diamondback moth, Plutella xylostella, is recognized as a widely distributed destructive insect pest of Brassica worldwide. The management of this pest is a serious issue, and an estimated annual cost of its management has reached approximately US$4 billion. Despite the fact that chemicals are a serious threat to the environment, lots of chemicals are applied for controlling various insect pests especially P. xylostella. An overreliance on chemical control has not only led to the evolution of resistance to insecticides and to a reduction of natural enemies but also has polluted various components of water, air, and soil ecosystem. In the present scenario, there is a need to implement an environmentally friendly integrated pest management (IPM) approach with new management tactics (microbial control, biological control, cultural control, mating disruption, insecticide rotation strategies, and plant resistance) for an alternative to chemical control. The IPM approach is not only economically beneficial but also reduces the environmental and health risks. The present review synthesizes published information on the insecticide resistance against P. xylostella and emphasizes on adopting an alternative environmentally friendly IPM approach for controlling P. xylostella in China.

Development of hazard analysis by critical control points (HACCP) procedures to control organic chemical hazards in the agricultural production of raw food commodities.

Science.gov (United States)

Ropkins, Karl; Ferguson, Andrew; Beck, Angus J

2003-01-01

Hazard Analysis by Critical Control Points (HACCP) is a systematic approach to the identification, assessment, and control of hazards in the food chain. Effective HACCP requires the consideration of all chemical microbiological, and physical hazards. However, current procedures focus primarily on microbiological and physical hazards, while chemical aspects of HACCP have received relatively little attention. In this article we discuss the application of HACCP to organic chemical contaminants and the problems that are likely to be encountered in agriculture. We also present generic templates for the development of organic chemical contaminant HACCP procedures for selected raw food commodities, that is, cereal crops,raw meats, and milk.

Effect of chemical and mechanical weed control on cassava yield, soil quality and erosion under cassava cropping system

Science.gov (United States)

Islami, Titiek; Wisnubroto, Erwin; Utomo, Wani

2016-04-01

Three years field experiments were conducted to study the effect of chemical and mechanical weed control on soil quality and erosion under cassava cropping system. The experiment were conducted at University Brawijaya field experimental station, Jatikerto, Malang, Indonesia. The experiments were carried out from 2011 - 2014. The treatments consist of three cropping system (cassava mono culture; cassava + maize intercropping and cassava + peanut intercropping), and two weed control method (chemical and mechanical methods). The experimental result showed that the yield of cassava first year and second year did not influenced by weed control method and cropping system. However, the third year yield of cassava was influence by weed control method and cropping system. The cassava yield planted in cassava + maize intercropping system with chemical weed control methods was only 24 t/ha, which lower compared to other treatments, even with that of the same cropping system used mechanical weed control. The highest cassava yield in third year was obtained by cassava + peanuts cropping system with mechanical weed control method. After three years experiment, the soil of cassava monoculture system with chemical weed control method possessed the lowest soil organic matter, and soil aggregate stability. During three years of cropping soil erosion in chemical weed control method, especially on cassava monoculture, was higher compared to mechanical weed control method. The soil loss from chemical control method were 40 t/ha, 44 t/ha and 54 t/ha for the first, second and third year crop. The soil loss from mechanical weed control method for the same years was: 36 t/ha, 36 t/ha and 38 t/ha. Key words: herbicide, intercropping, soil organic matter, aggregate stability.

Experimental Investigation of Electro-chemical Processes Controlled by High Magnetic Fields.

Czech Academy of Sciences Publication Activity Database

Mathon, Ph.; Nouri, A.; Alemany, A.; Chopart, J.P.; Sobolík, Václav

2006-01-01

Roč. 42, 4 (2006) , s. 363-369 ISSN 0024-998X Institutional research plan: CEZ:AV0Z40720504 Keywords : lorentz and magnetic force * diffusion-controlled regime * electrical current Subject RIV: CI - Industrial Chemistry, Chemical Engineering

77 FR 43863 - Manufacturer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals Inc.

Science.gov (United States)

2012-07-26

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Manufacturer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals Inc. Pursuant to Sec. 1301.33(a), Title 21 of the Code of Federal Regulations (CFR), this is notice that on June 8, 2012, Boehringer Ingelheim Chemicals...

78 FR 39340 - Manufacturer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals, Inc.

Science.gov (United States)

2013-07-01

... DEPARTMENT OF JUSTICE Drug Enforcement Administration Manufacturer of Controlled Substances; Notice of Application; Boehringer Ingelheim Chemicals, Inc. Pursuant to Sec. 1301.33(a), Title 21 of the Code of Federal Regulations (CFR), this is notice that on May 31, 2013, Boehringer Ingelheim Chemicals...

COMPLIANCE AS FACTORING BUSINESS RISK MANAGEMENT: CONTROL ASPECTS

Directory of Open Access Journals (Sweden)

V.K. Makarovych

2016-03-01

Full Text Available Indetermination of modern economy conditions and the lack of theoretical knowledge gained by domestic scientists about risk in factoring business actualize the research concerning the methodology and technique of factoring companies’ risk management. The article examines compliance which is the technology innovative for Ukrainian market of factoring risk management technologies. It is determined that the compliance is the risk management process directed to free will correspondence to state, international legislation as well as to the ethics standards accepted in the field of regulated legal relations and to the traditions of business circulation to sustain the necessary regulations and standards of market behaviour, and to consolidate the image of a factoring company. Compliance risks should be understood as the risks of missed profit or losses caused by the conflicts of interests and the discrepancy of employees’ actions to internal and external standard documents. The attention is paid to the control over the compliance. The author singles out 3 kinds of the compliance control such as institutional, operational and the compliance control over the observance of conducting business professional ethics regulations which are necessary for providing of efficient management of factoring business risks. The paper shows the organizing process of factoring business compliance control (by the development of internal standard documents, a compliance program, the foundation of compliance control subdivision, monitoring of the risks cause the choice, made by management entities of a factoring company, of the management methods of risks for their business. The development of new and improvement of existed forms of compliance control organizing process help satisfy users’ information needs and requests of the risk management factoring company department. The suggestions proposed create the grounds for the transformation and improvement of factoring

Margins of safety provided by COSHH Essentials and the ILO Chemical Control Toolkit.

Science.gov (United States)

Jones, Rachael M; Nicas, Mark

2006-03-01

COSHH Essentials, developed by the UK Health and Safety Executive, and the Chemical Control Toolkit (Toolkit) proposed by the International Labor Organization, are 'control banding' approaches to workplace risk management intended for use by proprietors of small and medium-sized businesses. Both systems group chemical substances into hazard bands based on toxicological endpoint and potency. COSSH Essentials uses the European Union's Risk-phrases (R-phrases), whereas the Toolkit uses R-phrases and the Globally Harmonized System (GHS) of Classification and Labeling of Chemicals. Each hazard band is associated with a range of airborne concentrations, termed exposure bands, which are to be attained by the implementation of recommended control technologies. Here we analyze the margin of safety afforded by the systems and, for each hazard band, define the minimal margin as the ratio of the minimum airborne concentration that produced the toxicological endpoint of interest in experimental animals to the maximum concentration in workplace air permitted by the exposure band. We found that the minimal margins were always occupational exposure limits, we argue that the minimal margins are better indicators of health protection. Further, given the small margins observed, we feel it is important that revisions of these systems provide the exposure bands to users, so as to permit evaluation of control technology capture efficiency.

Volumetric and chemical control auxiliary circuit for a PWR primary circuit

International Nuclear Information System (INIS)

Costes, D.

1990-01-01

The volumetric and chemical control circuit has an expansion tank with at least one water-steam chamber connected to the primary circuit by a sampling pipe and a reinjection pipe. The sampling pipe feeds jet pumps controlled by valves. An action on these valves and pumps regulates the volume of the water in the primary circuit. A safety pipe controlled by a flap automatically injects water from the chamber into the primary circuit in case of ruptures. The auxiliary circuit has also systems for purifying the water and controlling the boric acid and hydrogen content [fr

Chemical Cocktails Enable Hepatic Reprogramming of Mouse Fibroblasts with a Single Transcription Factor

Directory of Open Access Journals (Sweden)

Ren Guo

2017-08-01

Full Text Available Liver or hepatocytes transplantation is limited by the availability of donor organs. Functional hepatocytes independent of the donor sources may have wide applications in regenerative medicine and the drug industry. Recent studies have demonstrated that chemical cocktails may induce reprogramming of fibroblasts into a range of functional somatic cells. Here, we show that mouse fibroblasts can be transdifferentiated into the hepatocyte-like cells (iHeps using only one transcription factor (TF (Foxa1, Foxa2, or Foxa3 plus a chemical cocktail. These iHeps show typical epithelial morphology, express multiple hepatocyte-specific genes, and acquire hepatocyte functions. Genetic lineage tracing confirms the fibroblast origin of these iHeps. More interestingly, these iHeps are expandable in vitro and can reconstitute the damaged hepatic tissues of the fumarylacetoacetate hydrolase-deficient (Fah−/− mice. Our study provides a strategy to generate functional hepatocyte-like cells by using a single TF plus a chemical cocktail and is one step closer to generate the full-chemical iHeps.

Structure-mechanism-based engineering of chemical regulators targeting distinct pathological factors in Alzheimer's disease.

Science.gov (United States)

Beck, Michael W; Derrick, Jeffrey S; Kerr, Richard A; Oh, Shin Bi; Cho, Woo Jong; Lee, Shin Jung C; Ji, Yonghwan; Han, Jiyeon; Tehrani, Zahra Aliakbar; Suh, Nayoung; Kim, Sujeong; Larsen, Scott D; Kim, Kwang S; Lee, Joo-Yong; Ruotolo, Brandon T; Lim, Mi Hee

2016-10-13

The absence of effective therapeutics against Alzheimer's disease (AD) is a result of the limited understanding of its multifaceted aetiology. Because of the lack of chemical tools to identify pathological factors, investigations into AD pathogenesis have also been insubstantial. Here we report chemical regulators that demonstrate distinct specificity towards targets linked to AD pathology, including metals, amyloid-β (Aβ), metal-Aβ, reactive oxygen species, and free organic radicals. We obtained these chemical regulators through a rational structure-mechanism-based design strategy. We performed structural variations of small molecules for fine-tuning their electronic properties, such as ionization potentials and mechanistic pathways for reactivity towards different targets. We established in vitro and/or in vivo efficacies of the regulators for modulating their targets' reactivities, ameliorating toxicity, reducing amyloid pathology, and improving cognitive deficits. Our chemical tools show promise for deciphering AD pathogenesis and discovering effective drugs.

Combined impact of lead, cadmium, polychlorinated biphenyls and non-chemical risk factors on blood pressure in NHANES

International Nuclear Information System (INIS)

Peters, Junenette L.; Patricia Fabian, M.; Levy, Jonathan I.

2014-01-01

High blood pressure is associated with exposure to multiple chemical and non-chemical risk factors, but epidemiological analyses to date have not assessed the combined effects of both chemical and non-chemical stressors on human populations in the context of cumulative risk assessment. We developed a novel modeling approach to evaluate the combined impact of lead, cadmium, polychlorinated biphenyls (PCBs), and multiple non-chemical risk factors on four blood pressure measures using data for adults aged ≥20 years from the National Health and Nutrition Examination Survey (1999–2008). We developed predictive models for chemical and other stressors. Structural equation models were applied to account for complex associations among predictors of stressors as well as blood pressure. Models showed that blood lead, serum PCBs, and established non-chemical stressors were significantly associated with blood pressure. Lead was the chemical stressor most predictive of diastolic blood pressure and mean arterial pressure, while PCBs had a greater influence on systolic blood pressure and pulse pressure, and blood cadmium was not a significant predictor of blood pressure. The simultaneously fit exposure models explained 34%, 43% and 52% of the variance for lead, cadmium and PCBs, respectively. The structural equation models were developed using predictors available from public data streams (e.g., U.S. Census), which would allow the models to be applied to any U.S. population exposed to these multiple stressors in order to identify high risk subpopulations, direct intervention strategies, and inform public policy. - Highlights: • We evaluated joint impact of chemical and non-chemical stressors on blood pressure. • We built predictive models for lead, cadmium and polychlorinated biphenyls (PCBs). • Our approach allows joint evaluation of predictors from population-specific data. • Lead, PCBs and established non-chemical stressors were related to blood pressure. �

Combined impact of lead, cadmium, polychlorinated biphenyls and non-chemical risk factors on blood pressure in NHANES

Energy Technology Data Exchange (ETDEWEB)

Peters, Junenette L., E-mail: petersj@bu.edu; Patricia Fabian, M., E-mail: pfabian@bu.edu; Levy, Jonathan I., E-mail: jonlevy@bu.edu

2014-07-15

High blood pressure is associated with exposure to multiple chemical and non-chemical risk factors, but epidemiological analyses to date have not assessed the combined effects of both chemical and non-chemical stressors on human populations in the context of cumulative risk assessment. We developed a novel modeling approach to evaluate the combined impact of lead, cadmium, polychlorinated biphenyls (PCBs), and multiple non-chemical risk factors on four blood pressure measures using data for adults aged ≥20 years from the National Health and Nutrition Examination Survey (1999–2008). We developed predictive models for chemical and other stressors. Structural equation models were applied to account for complex associations among predictors of stressors as well as blood pressure. Models showed that blood lead, serum PCBs, and established non-chemical stressors were significantly associated with blood pressure. Lead was the chemical stressor most predictive of diastolic blood pressure and mean arterial pressure, while PCBs had a greater influence on systolic blood pressure and pulse pressure, and blood cadmium was not a significant predictor of blood pressure. The simultaneously fit exposure models explained 34%, 43% and 52% of the variance for lead, cadmium and PCBs, respectively. The structural equation models were developed using predictors available from public data streams (e.g., U.S. Census), which would allow the models to be applied to any U.S. population exposed to these multiple stressors in order to identify high risk subpopulations, direct intervention strategies, and inform public policy. - Highlights: • We evaluated joint impact of chemical and non-chemical stressors on blood pressure. • We built predictive models for lead, cadmium and polychlorinated biphenyls (PCBs). • Our approach allows joint evaluation of predictors from population-specific data. • Lead, PCBs and established non-chemical stressors were related to blood pressure. �

Plant management in natural areas: balancing chemical, mechanical, and cultural control methods

Science.gov (United States)

Steven Manning; James. Miller

2011-01-01

After determining the best course of action for control of an invasive plant population, it is important to understand the variety of methods available to the integrated pest management professional. A variety of methods are now widely used in managing invasive plants in natural areas, including chemical, mechanical, and cultural control methods. Once the preferred...

Automatic control of the effluent turbidity from a chemically enhanced primary treatment with microsieving.

Science.gov (United States)

Väänänen, J; Memet, S; Günther, T; Lilja, M; Cimbritz, M; la Cour Jansen, J

2017-10-01

For chemically enhanced primary treatment (CEPT) with microsieving, a feedback proportional integral controller combined with a feedforward compensator was used in large pilot scale to control effluent water turbidity to desired set points. The effluent water turbidity from the microsieve was maintained at various set points in the range 12-80 NTU basically independent for a number of studied variations in influent flow rate and influent wastewater compositions. Effluent turbidity was highly correlated with effluent chemical oxygen demand (COD). Thus, for CEPT based on microsieving, controlling the removal of COD was possible. Thereby incoming carbon can be optimally distributed between biological nitrogen removal and anaerobic digestion for biogas production. The presented method is based on common automation and control strategies; therefore fine tuning and optimization for specific requirements are simplified compared to model-based dosing control.

The influences of the physical-chemical factors on the free-volume relations in polymers

International Nuclear Information System (INIS)

Bartos, J.; Kristiak, J.; Kristiakova, K.; Sausa, O.; Bandzuch, P.

1995-01-01

The positron annihilation spectroscopy was used to the study of different physical-chemical factors on the free-volume microstructure of the model polymeric systems [amorphous 1,4-cis-poly(butadiene), amorphous a-tactic and semi-crystal iso-tactic poly(propylene), polycarbonate

Integrated Process Design, Control and Analysis of Intensified Chemical Processes

DEFF Research Database (Denmark)

Mansouri, Seyed Soheil

chemical processes; for example, intensified processes such as reactive distillation. Most importantly, it identifies and eliminates potentially promising design alternatives that may have controllability problems later. To date, a number of methodologies have been proposed and applied on various problems......, that the same principles that apply to a binary non-reactive compound system are valid also for a binary-element or a multi-element system. Therefore, it is advantageous to employ the element based method for multicomponent reaction-separation systems. It is shown that the same design-control principles...

Is the efficacy of biological control against plant diseases likely to be more durable than that of chemical pesticides?

Directory of Open Access Journals (Sweden)

Marc eBardin

2015-07-01

Full Text Available The durability of a control method for plant protection is defined as the persistence of its efficacy in space and time. It depends on (i the selection pressure exerted by it on populations of plant pathogens and (ii on the capacity of these pathogens to adapt to the control method. Erosion of effectiveness of conventional plant protection methods has been widely studied in the past. For example, apparition of resistance to chemical pesticides in plant pathogens or pests has been extensively documented. The durability of biological control has often been assumed to be higher than that of chemical control. Results concerning pest management in agricultural systems have shown that this assumption may not always be justified. Resistance of various pests to one or several toxins of Bacillus thuringensis and apparition of resistance of the codling moth Cydia pomonella to the Cydia pomonella granulovirus have, for example, been described. In contrast with the situation for pests, the durability of biological control of plant diseases has hardly been studied and no scientific reports proving the loss of efficiency of biological control agents against plant pathogens in practice has been published so far. Knowledge concerning the possible erosion of effectiveness of biological control is essential to ensure a durable efficacy of biological control agents on target plant pathogens. This knowledge will result in identifying risk factors that can foster the selection of strains of plant pathogens resistant to biological control agents. It will also result in identifying types of biological control agents with lower risk of efficacy loss i.e. modes of action of biological control agents that does not favor the selection of resistant isolates in natural populations of plant pathogens. An analysis of the scientific literature was then conducted to assess the potential for plant pathogens to become resistant to biological control agents.

Remote-controlling chemical reactions by light: towards chemistry with high spatio-temporal resolution.

Science.gov (United States)

Göstl, Robert; Senf, Antti; Hecht, Stefan

2014-03-21

The foundation of the chemical enterprise has always been the creation of new molecular entities, such as pharmaceuticals or polymeric materials. Over the past decades, this continuing effort of designing compounds with improved properties has been complemented by a strong effort to render their preparation (more) sustainable by implementing atom as well as energy economic strategies. Therefore, synthetic chemistry is typically concerned with making specific bonds and connections in a highly selective and efficient manner. However, to increase the degree of sophistication and expand the scope of our work, we argue that the modern aspiring chemist should in addition be concerned with attaining (better) control over when and where chemical bonds are being made or broken. For this purpose, photoswitchable molecular systems, which allow for external modulation of chemical reactions by light, are being developed and in this review we are covering the current state of the art of this exciting new field. These "remote-controlled synthetic tools" provide a remarkable opportunity to perform chemical transformations with high spatial and temporal resolution and should therefore allow regulating biological processes as well as material and device performance.

A non-chemical system for online weed control.

Science.gov (United States)

Rueda-Ayala, Victor; Peteinatos, Gerassimos; Gerhards, Roland; Andújar, Dionisio

2015-03-30

Non-chemical weed control methods need to be directed towards a site-specific weeding approach, in order to be able to compete the conventional herbicide equivalents. A system for online weed control was developed. It automatically adjusts the tine angle of a harrow and creates different levels of intensity: from gentle to aggressive. Two experimental plots in a maize field were harrowed with two consecutive passes. The plots presented from low to high weed infestation levels. Discriminant capabilities of an ultrasonic sensor were used to determine the crop and weed variability of the field. A controlling unit used ultrasonic readings to adjust the tine angle, producing an appropriate harrowing intensity. Thus, areas with high crop and weed densities were more aggressively harrowed, while areas with lower densities were cultivated with a gentler treatment; areas with very low densities or without weeds were not treated. Although the weed development was relatively advanced and the soil surface was hard, the weed control achieved by the system reached an average of 51% (20%-91%), without causing significant crop damage as a result of harrowing. This system is proposed as a relatively low cost, online, and real-time automatic harrow that improves the weed control efficacy, reduces energy consumption, and avoids the usage of herbicide.

Intelligent process control of fiber chemical vapor deposition

Science.gov (United States)

Jones, John Gregory

Chemical Vapor Deposition (CVD) is a widely used process for the application of thin films. In this case, CVD is being used to apply a thin film interface coating to single crystal monofilament sapphire (Alsb2Osb3) fibers for use in Ceramic Matrix Composites (CMC's). The hot-wall reactor operates at near atmospheric pressure which is maintained using a venturi pump system. Inert gas seals obviate the need for a sealed system. A liquid precursor delivery system has been implemented to provide precise stoichiometry control. Neural networks have been implemented to create real-time process description models trained using data generated based on a Navier-Stokes finite difference model of the process. Automation of the process to include full computer control and data logging capability is also presented. In situ sensors including a quadrupole mass spectrometer, thermocouples, laser scanner, and Raman spectrometer have been implemented to determine the gas phase reactants and coating quality. A fuzzy logic controller has been developed to regulate either the gas phase or the in situ temperature of the reactor using oxygen flow rate as an actuator. Scanning electron microscope (SEM) images of various samples are shown. A hierarchical control structure upon which the control structure is based is also presented.

Dietary pattern and lifestyle factors in asthma control

Directory of Open Access Journals (Sweden)

Mohammed Noufal Poongadan

2016-01-01

Full Text Available Background: The prevalence of asthma in adults varied from 0.96% to 11.03% while in children ranged from 2.3% to 11.9% in India. A number of factors including genetic predisposition, environment, and lifestyle factors including dietary habits influence the development and expression of asthma. The goal of asthma treatment is to achieve and maintain clinical control, which can be achieved in a majority of patients with pharmacologic intervention strategy. Objective: To assess the role of diet and lifestyle factors in asthma control in Indian population. Materials and Methods: Diagnosed asthma patients (aged 12-40 years were enrolled from the outpatient clinics. All patients were followed up and reassessed after 4 weeks with asthma control test (ACT and dietary and lifestyle questionnaire. The assessment of dietary pattern was performed by food frequency questionnaire (Nordic Nutrition Recommendations-Danish Physical Activity Questionnaire. The lifestyle factor included body mass index, smoking status, tobacco chewing, alcohol consumption, duration of travel (h/week, mental stress (visual analog scale: 0-10, sports activity - h/day, television (TV watching/video games - h/day, duration of sleep - h/day. Results: Seventy-five asthma patients (43 males and 32 females were divided into three groups according to ACT, 18 (24% patients in poorly-controlled asthma, 35 (46.7% in well-controlled asthma, and 22 (29.3% patients with totally-controlled asthma. Increased consumption of vegetables and cereals in patients with total-controlled asthma while increased consumption of sugar, nonvegetarian, fast food, salted and fried snacks in patients with poorly-controlled asthma. Poorly-controlled asthma had the highest duration of watching TV and sleep and least duration of travel and sports, though the results failed to reach statistical significance. Conclusion: The dietary and lifestyle factors too contribute to degree of control of asthma in India.

76 FR 17778 - Control of Ergocristine, a Chemical Precursor Used in the Illicit Manufacture of Lysergic Acid...

Science.gov (United States)

2011-03-31

... 1117-AB24 Control of Ergocristine, a Chemical Precursor Used in the Illicit Manufacture of Lysergic... for the List I chemicals ergotamine and ergonovine to illicitly manufacture the schedule I controlled..., due to growing concerns regarding its use for the illicit manufacture of LSD. [[Page 17779...

Controlled air incineration of hazardous chemical and mixed waste at Los Alamos

International Nuclear Information System (INIS)

Borduin, L.C.; Hutchins, D.A.; Vavruska, J.J.; Warner, C.L.

1987-01-01

The Los Alamos National Laboratory (LANL) Controlled Air Incineration (CAI) system, originally developed for transuranic (TRU) waste volume reduction studies, is currently being qualified for hazardous chemical and mixed waste treatment under provisions of the Resource Conservation and Recovery Act (RCRA). The objective is to obtain a permanent RCRA Part B permit for thermal disposal of hazardous and mixed wastes generated by LANL. Constructed in the mid-1970s as a demonstration project for incineration of TRU solid wastes, the CAI process was substantially modified and tested in 1980-1983 for acceptance of both liquid and solid hazardous chemicals. Successful demonstration of TRU solid waste processing objectives in 1979 and later chemical waste incineration studies have been documented in several publications. In 1984, the LANL CAI became the first US Dept. of Energy (DOE) incinerator to be permitted for polychlorinated biphenyl disposal under the Toxic Substances Control Act. Following establishment of Environmental Protection Agency (EPA) jurisdiction over DOE chemical waste management in 1984, LANL sought and was granted interim status for the CAI and applied for a trial burn permit in the overall laboratory RCRA Part B application. A trial burn and final report have been completed; results have been submitted to EPA and the New Mexico Environmental Improvement Division. This paper provides an overview of trial burn planning and results together with the operational status of LANL's CAI

Structure and behavior as determinants: United States nuclear test ban and chemical and biological arms control policy

International Nuclear Information System (INIS)

Reich, J.C.

1991-01-01

US efforts to control chemical and biological warfare and nuclear testing are examined with the aim of explaining the paucity of US backed agreements in these areas. Two theoretical perspectives, the behavioral and structural approaches, are used to explore US arms control outcomes. In the behavioral approach, the effects of governmental organization and the bargaining dynamics of policy-making elites with different cognitive styles are posited as important influences on US nuclear test ban and chemical and biological arms control policy outcomes. The behavioral perspective accounts for the timing of all US failed and successful entries (with one exception) into nuclear test bans and chemical and biological warfare restraints. A shortcoming of the behavior approach, however, is that it tends to overemphasize the chances for successful US entry into nuclear test and chemical and biological warfare limitations. Analysis of the same events from the structural perspective helps to correct for expectations generated by behavioral variables for a higher success rate than ultimately resulted. In the structural approach, the focus is on the effect of the organization of international politics on US nuclear test ban and chemical and biological arms control policy outcomes

Comparison of dilution factors for German wastewater treatment plant effluents in receiving streams to the fixed dilution factor from chemical risk assessment.

Science.gov (United States)

Link, Moritz; von der Ohe, Peter C; Voß, Katharina; Schäfer, Ralf B

2017-11-15

Incomplete removal during wastewater treatment leads to frequent detection of compounds such as pharmaceuticals and personal care products in municipal effluents. A fixed standard dilution factor of 10 for effluents entering receiving water bodies is used during the exposure assessment of several chemical risk assessments. However, the dilution potential of German receiving waters under low flow conditions is largely unknown and information is sparse for other European countries. We calculated dilution factors for two datasets differing in spatial extent and wastewater treatment plant (WWTP) size: a national dataset comprising 1225 large WWTPs in Central and Northern Germany and a federal dataset for 678 WWTPs of a single state in Southwest Germany. We found that the fixed factor approach overestimates the dilution potential of 60% and 40% of receiving waters in the national and the federal dataset, with median dilution factors of 5 and 14.5, respectively. Under mean flow conditions, 8% of calculated dilution factors were below 10, with a median dilution factor of 106. We also calculated regional dilution factors that accounted for effluent inputs from upstream WWTPs. For the national and the federal dataset, 70% and 60% of calculated regional dilution factors fell below 10 under mean low flow conditions, respectively. Decrease of regional dilution potential in small receiving streams was mainly driven by the next WWTP upstream with a 2.5 fold drop of median regional dilution factors. Our results show that using the standard dilution factor of 10 would result in the underestimation of environmental concentrations for authorised chemicals by a factor of 3-5 for about 10% of WWTPs, especially during low flow conditions. Consequently, measured environmental concentrations might exceed predicted environmental concentrations and ecological risks posed by effluents could be much higher, suggesting that a revision of current risk assessment practices may be required

B827 Chemical Synthhesis Project - Industrial Control System Integration - Statement of Work & Specification with Attachments 1-14

Energy Technology Data Exchange (ETDEWEB)

Wade, F. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-04-21

The Chemical Synthesis Pilot Process at the Lawrence Livermore National Laboratory (LLNL) Site 300 827 Complex will be used to synthesize small quantities of material to support research and development. The project will modernize and increase current capabilities for chemical synthesis at LLNL. The primary objective of this project is the conversion of a non-automated hands-on process to a remoteoperation process, while providing enhanced batch process step control, stored recipe-specific parameter sets, process variable visibility, monitoring, alarm and warning handling, and comprehensive batch record data logging. This Statement of Work and Specification provides the industrial-grade process control requirements for the chemical synthesis batching control system, hereafter referred to as the “Control System” to be delivered by the System Integrator.

Human factors challenges for advanced process control

International Nuclear Information System (INIS)

Stubler, W.F.; O'Hara, J..M.

1996-01-01

New human-system interface technologies provide opportunities for improving operator and plant performance. However, if these technologies are not properly implemented, they may introduce new challenges to performance and safety. This paper reports the results from a survey of human factors considerations that arise in the implementation of advanced human-system interface technologies in process control and other complex systems. General trends were identified for several areas based on a review of technical literature and a combination of interviews and site visits with process control organizations. Human factors considerations are discussed for two of these areas, automation and controls

Los Alamos Controlled Air Incinerator for hazardous chemical and mixed radioactive wastes

International Nuclear Information System (INIS)

Vavruska, J.S.; Borduin, L.C.; Hutchins, D.A.; Koenig, R.A.; Warner, C.L.

1986-01-01

The Los Alamos Controlled Air Incinerator (CAI) is currently the only radioactive waste incineration facility in the US permitted to treat polychlorinated biphenyls (PCBs). The CAI was developed in the mid-1970's as a demonstration system for volume reduction of transuranic (TRU) contaminated combustible solid wastes. It has since undergone additions and modifications to accommodate hazardous chemical wastes in response to a need within the Department of Energy (DOE) to treat mixed radioactive/chemical wastes. An overview of these additions which include a liquid feed system, a high intensity liquid injection burner, and an activated carbon adsorption unit is presented here. Also included is a discussion of the procedures required for Toxic Substances Control Act (TSCA) and Resource Conservation and Recovery Act (RCRA) permitting of the CAI

A cellular automata approach to chemical reactions : 1 reaction controlled systems

NARCIS (Netherlands)

Korte, de A.C.J.; Brouwers, H.J.H.

2013-01-01

A direct link between the chemical reaction controlled (shrinking core) model and cellular automata, to study the dissolution of particles, is derived in this paper. Previous research on first and second order reactions is based on the concentration of the reactant. The present paper describes the

Synthetically chemical-electrical mechanism for controlling large scale reversible deformation of liquid metal objects

Science.gov (United States)

Zhang, Jie; Sheng, Lei; Liu, Jing

2014-11-01

Reversible deformation of a machine holds enormous promise across many scientific areas ranging from mechanical engineering to applied physics. So far, such capabilities are still hard to achieve through conventional rigid materials or depending mainly on elastomeric materials, which however own rather limited performances and require complicated manipulations. Here, we show a basic strategy which is fundamentally different from the existing ones to realize large scale reversible deformation through controlling the working materials via the synthetically chemical-electrical mechanism (SCHEME). Such activity incorporates an object of liquid metal gallium whose surface area could spread up to five times of its original size and vice versa under low energy consumption. Particularly, the alterable surface tension based on combination of chemical dissolution and electrochemical oxidation is ascribed to the reversible shape transformation, which works much more flexible than many former deformation principles through converting electrical energy into mechanical movement. A series of very unusual phenomena regarding the reversible configurational shifts are disclosed with dominant factors clarified. This study opens a generalized way to combine the liquid metal serving as shape-variable element with the SCHEME to compose functional soft machines, which implies huge potential for developing future smart robots to fulfill various complicated tasks.

Chemical control of ticks on cattle and the resistance of these parasites to acaricides.

Science.gov (United States)

George, J E; Pound, J M; Davey, R B

2004-01-01

Toward the end of the nineteenth century a complex of problems related to ticks and tick-borne diseases of cattle created a demand for methods to control ticks and reduce losses of cattle. The discovery and use of arsenical solutions in dipping vats for treating cattle to protect them against ticks revolutionized tick and tick-borne disease control programmes. Arsenic dips for cattle were used for about 40 years before the evolution of resistance of ticks to the chemical, and the development and marketing of synthetic organic acaricides after World War II provided superior alternative products. Most of the major groups of organic pesticides are represented on the list of chemicals used to control ticks on cattle. Unfortunately, the successive evolution of resistance of ticks to acaricides in each chemical group with the concomitant reduction in the usefulness of a group of acaricides is a major reason for the diversity of acaricides. Whether a producer chooses a traditional method for treating cattle with an acaricide or uses a new method, he must recognize the benefits, limitations and potential problems with each application method and product. Simulation models and research were the basis of recommendations for tick control strategies advocating approaches that reduced reliance on acaricides. These recommendations for controlling ticks on cattle are in harmony with recommendations for reducing the rate of selection for acaricide resistance. There is a need to transfer knowledge about tick control and resistance mitigation strategies to cattle producers.

76 FR 35130 - Pipeline Safety: Control Room Management/Human Factors

Science.gov (United States)

2011-06-16

...: Control Room Management/Human Factors AGENCY: Pipeline and Hazardous Materials Safety Administration... the Control Room Management/Human Factors regulations in order to realize the safety benefits sooner... FR 5536). By this amendment to the Control Room Management/Human Factors (CRM) rule, an operator must...

Localized temperature and chemical reaction control in nanoscale space by nanowire array.

Science.gov (United States)

Jin, C Yan; Li, Zhiyong; Williams, R Stanley; Lee, K-Cheol; Park, Inkyu

2011-11-09

We introduce a novel method for chemical reaction control with nanoscale spatial resolution based on localized heating by using a well-aligned nanowire array. Numerical and experimental analysis shows that each individual nanowire could be selectively and rapidly Joule heated for local and ultrafast temperature modulation in nanoscale space (e.g., maximum temperature gradient 2.2 K/nm at the nanowire edge; heating/cooling time chemical reactions such as polymer decomposition/cross-linking and direct and localized hydrothermal synthesis of metal oxide nanowires were demonstrated.

Risk factors associated with lipomyelomeningocele: a case-control study.

Science.gov (United States)

Esmaeili, Arash; Hanaei, Sara; Fadakar, Kaveh; Dadkhah, Sahar; Arjipour, Mahdi; Habibi, Zohreh; Nejat, Farideh; El Khashab, Mostafa

2013-01-01

In general, it seems that both genetic and environmental factors play important roles in the induction of neural tube defects. Lipomyelomeningocele (LipoMMC) is a rather common type of closed neural tube defect, but only limited studies have investigated the potential risk factors of this anomaly. Therefore, the purpose of this case-control study was to investigate the risk factors involved in LipoMMC formation. Various risk factors were evaluated in 35 children between 1 month and 10 years of age with LipoMMC in a hospital-based case-control study. The 2 control arms consisted of 35 children with myelomeningocele (MMC group) and 35 children with congenital anomalies other than central nervous system problems (control group). All groups were matched for age and visited the same hospital. A structured questionnaire was used for the collection of all data, including the mothers' weight and height during pregnancy, education, reproductive history, previous abortions, and socioeconomic status, as well as the parents' consanguinity and family history of the same anomalies. Univariate analysis of the children with LipoMMC compared to the control group showed that the use of periconceptional folic acid supplementation was significantly lower in the MMC and LipoMMC groups compared to the control group. In addition, comparison of the MMC and control groups revealed statistically significant differences regarding the use of folic acid and maternal obesity. In multivariate analysis, use of folic acid in the periconceptional period and during the first trimester was an independent risk factor for LipoMMC and MMC. Furthermore, maternal obesity was a significantly positive risk factor for MMC. The probable risk factors for LipoMMC were investigated in this case-control study. Consumption of folic acid in the periconceptional period and during the first trimester is an independent protective factor against LipoMMC. It seems that larger studies are needed to examine other possible

X-ray fluorescence control of chemical composition of cast iron

International Nuclear Information System (INIS)

Prekina, I.M.; Rozova, O.F.; Loran, A.V.; Teplitskaya, G.A.; Smagunova, A.N.

1995-01-01

A method of x-ray fluorescence analysis developed for analytical set (KRF-18 diffractometer/DVK-3 computer) is used to control cast iron composition. A quantitative evaluation of errors attributed to the violation of conditions of cast iron sampling from the flow and to the quality of preparing samples for XFA is obtained. It is shown that the main component of the integral experimental error is attributed to nonuniformity of chemical composition of cast iron. Metrological studies show that reproductibility, convergence, accuracy, and sensitivity of the method match the requirements characteristic of the control process. 4 refs.; 2 tabs

Natural control in cabbage root fly populations and influence of chemicals

NARCIS (Netherlands)

Abu Yaman, I.K.

1960-01-01

To facilitate studies on the natural and chemical control of Hylemya (Erioischia) brassicae (Bch.) in Holland, the bionomics and abundance of the Anthomyiid were investigated in 1959-9 in fields in which cauliflower was grown. The numbers of eggs and larvae were estimated by scrutiny of

78 FR 40175 - Exempt Chemical Preparations Under the Controlled Substances Act

Science.gov (United States)

2013-07-03

...Standard, Inc M-8270-04-ASL, Method 8270B-- Amber ampule: 1 mL...... 1/28/2013 Base/Neutrals Mix. Accu... CSA and its implementing regulations are designed to prevent, detect, and eliminate the diversion of... controlled substances and listed chemicals for legitimate medical, scientific, research, and industrial...

Scientific and technical conference. Problems and horizons of development of chemical and radiochemical control in nuclear energetics. Collection of summaries of reports

International Nuclear Information System (INIS)

2001-01-01

During scientific and technical conference on problems of development of chemical and radiochemical control in nuclear energetics following themes were considered: the problems of methodological and instrumental assurance of chemical and radiochemical control at working nuclear power plants and nuclear energetic units; modern conceptions of automation systems construction of chemical and radiochemical control on the basis of intellectual measuring channels; the ways of decision of generally system problems of organization and management of chemical and radiochemical control using computed technologies; the problems of certification of chemical and radiochemical methods of measuring in nuclear energetics [ru

Chemical-Reaction-Controlled Phase Separated Drops: Formation, Size Selection, and Coarsening

Science.gov (United States)

Wurtz, Jean David; Lee, Chiu Fan

2018-02-01

Phase separation under nonequilibrium conditions is exploited by biological cells to organize their cytoplasm but remains poorly understood as a physical phenomenon. Here, we study a ternary fluid model in which phase-separating molecules can be converted into soluble molecules, and vice versa, via chemical reactions. We elucidate using analytical and simulation methods how drop size, formation, and coarsening can be controlled by the chemical reaction rates, and categorize the qualitative behavior of the system into distinct regimes. Ostwald ripening arrest occurs above critical reaction rates, demonstrating that this transition belongs entirely to the nonequilibrium regime. Our model is a minimal representation of the cell cytoplasm.

A multi target approach to control chemical reactions in their inhomogeneous solvent environment

International Nuclear Information System (INIS)

Keefer, Daniel; Thallmair, Sebastian; Zauleck, Julius P P; Vivie-Riedle, Regina de

2015-01-01

Shaped laser pulses offer a powerful tool to manipulate molecular quantum systems. Their application to chemical reactions in solution is a promising concept to redesign chemical synthesis. Along this road, theoretical developments to include the solvent surrounding are necessary. An appropriate theoretical treatment is helpful to understand the underlying mechanisms. In our approach we simulate the solvent by randomly selected snapshots from molecular dynamics trajectories. We use multi target optimal control theory to optimize pulses for the various arrangements of explicit solvent molecules simultaneously. This constitutes a major challenge for the control algorithm, as the solvent configurations introduce a large inhomogeneity to the potential surfaces. We investigate how the algorithm handles the new challenges and how well the controllability of the system is preserved with increasing complexity. Additionally, we introduce a way to statistically estimate the efficiency of the optimized laser pulses in the complete thermodynamical ensemble. (paper)

Human factors survey of advanced instrumentation and controls

International Nuclear Information System (INIS)

Carter, R.J.

1989-01-01

A survey oriented towards identifying the human factors issues in regard to the use of advanced instrumentation and controls (I ampersand C) in the nuclear industry was conducted. A number of United States (US) and Canadian nuclear vendors and utilities were participants in the survey. Human factors items, subsumed under the categories of computer-generated displays (CGD), controls, organizational support, training, and related topics, were discussed. The survey found the industry to be concerned about the human factors issues related to the implementation of advanced I ampersand C. Fifteen potential human factors problems were identified. They include: the need for an advanced I ampersand C guideline equivalent to NUREG-0700; a role change in the control room from operator to supervisor; information overload; adequacy of existing training technology for advanced I ampersand C; and operator acceptance and trust. 11 refs., 1 tab

Occupational and Environmental Risk Factors for Idiopathic Pulmonary Fibrosis in Egypt: A Multicenter Case-Control Study

Directory of Open Access Journals (Sweden)

NJ Awadalla

2012-06-01

Full Text Available Background: Despite the advances in medical therapy and technology, the prognosis of idiopathic pulmonary fibrosis (IPF remains poor and the need for disease prevention based on identifying the risk factors becomes mandatory. Occupational and environmental exposures were studied in several countries and found to play important role in the disease development. However, in Egypt, a little attention has been paid to study the effect of these factors in the disease development. Objective: To identify the occupational and environmental risk factors associated with the development of IPF in Egypt. Methods: A multicenter hospital-based case-control study was carried out in chest hospitals affiliated to three Egyptian cities—Cairo, Tanta and Mansoura. Subjects were 201 patients with confirmed IPF (cases and 205 age-, sex- and residence-matched controls. Data on occupational and environmental factors were obtained from a questionnaire. Multiple logistic regression analysis was used to determine the independent risk factors of IPF in both sexes for single factors with adjustment for age, residence and smoking status. Results: Compared with the controls, the risk of IPF in male workers was observed to increase significantly in chemical and petrochemical industries and carpentry and wood working (OR=2.56, 95% CI: 1.02–7.01, and with occupational exposures to wood dust and wood preservatives. Among female workers, a significant increase was observed in farming (OR=3.34, 95% CI: 1.17–10.12, raising birds and occupational exposures to animal feeds, products and dusts and pesticides. Risk of IPF decreased significantly in male workers and insignificantly among female workers in sales and clerical related activities. The environmental exposures to birds and cats were significantly associated with elevated risk of IPF development in both sexes. Conclusion: In Egypt, farming, raising birds and wood working are important risk factors for the development of

A coupled model between mechanical deformation and chemical diffusion: An explanation for the preservation of chemical zonation in plagioclase at high temperatures

Science.gov (United States)

Zhong, Xin; Vrijmoed, Johannes; Moulas, Evangelos; Tajcmanová, Lucie

2016-04-01

Compositional zoning in metamorphic minerals have been generally recognized as an important geological feature to decipher the metamorphic history of rocks. The observed chemical zoning of, e.g. garnet, is commonly interpreted as disequilibrium between the fractionated inner core and the surrounding matrix. However, chemically zoned minerals were also observed in high grade rocks (T>800 degree C) where the duration of metamorphic processes was independently dated to take several Ma. This implies that temperature may not be the only factor that controls diffusion timescales, and grain scale pressure variation was proposed to be a complementary factor that may significantly contribute to the formation and preservation of chemical zoning in high temperature metamorphic minerals [Tajcmanová 2013, 2015]. Here, a coupled model is developed to simulate viscous deformation and chemical diffusion. The numerical approach considers the conservation of mass, momentum, and a constitutive relation developed from equilibrium thermodynamics. A compressible viscoelastic rheology is applied, which associates the volumetric change triggered by deformation and diffusion to a change of pressure. The numerical model is applied to the chemically zoned plagioclase rim described by [Tajcmanová 2014]. The diffusion process operating during the plagioclase rim formation can lead to a development of a pressure gradient. Such a pressure gradient, if maintained during ongoing viscous relaxation, can lead to the preservation of the observed chemical zonation in minerals. An important dimensionless number, the Deborah number, is defined as the ratio between the Maxwell viscoelastic relaxation time and the characteristic diffusion time. It characterizes the relative influence between the maintenance of grain scale pressure variation and chemical diffusion. Two extreme regimes are shown: the mechanically-controlled regime (high Deborah number) and diffusion-controlled regime (low Deborah number

Femtosecond laser induced and controlled chemical reaction of carbon monoxide and hydrogen

CSIR Research Space (South Africa)

Du Plessis, A

2011-07-01

Full Text Available Results from experiments aimed at bimolecular chemical reaction control of CO and H2 at room temperature and pressure, without any catalyst, using shaped femtosecond laser pulses are presented. A stable reaction product (CO2) was measured after...

III Scientific-technical conference. Problems and outlooks for development of chemical and radiochemical control in atomic energetics (Atomenergoanalytics-2005). Summaries of reports

International Nuclear Information System (INIS)

2005-01-01

Summaries of reports of the III Scientific-technical conference: Problems and outlooks for development of chemical and radiochemical control in atomic energetics (Atomenergoanalytics-2005) are presented. The conference performed 20-22 September, 2005, in Sosnovyj Bor. Problems of methodical, instrumental and metrological supply of chemical, radiochemical and radiometric control at active NPP and NPU, modern concepts of construction of automated systems of chemical and radiometric control in the atomic energetics, directions for the decision of questions in organization and conducting of chemical and radiochemical control of water-chemical regimes of NPP and NPU are discussed [ru

Applying Human Factors Evaluation and Design Guidance to a Nuclear Power Plant Digital Control System

Energy Technology Data Exchange (ETDEWEB)

Thomas Ulrich; Ronald Boring; William Phoenix; Emily Dehority; Tim Whiting; Jonathan Morrell; Rhett Backstrom

2012-08-01

The United States (U.S.) nuclear industry, like similar process control industries, has moved toward upgrading its control rooms. The upgraded control rooms typically feature digital control system (DCS) displays embedded in the panels. These displays gather information from the system and represent that information on a single display surface. In this manner, the DCS combines many previously separate analog indicators and controls into a single digital display, whereby the operators can toggle between multiple windows to monitor and control different aspects of the plant. The design of the DCS depends on the function of the system it monitors, but revolves around presenting the information most germane to an operator at any point in time. DCSs require a carefully designed human system interface. This report centers on redesigning existing DCS displays for an example chemical volume control system (CVCS) at a U.S. nuclear power plant. The crucial nature of the CVCS, which controls coolant levels and boration in the primary system, requires a thorough human factors evaluation of its supporting DCS. The initial digital controls being developed for the DCSs tend to directly mimic the former analog controls. There are, however, unique operator interactions with a digital vs. analog interface, and the differences have not always been carefully factored in the translation of an analog interface to a replacement DCS. To ensure safety, efficiency, and usability of the emerging DCSs, a human factors usability evaluation was conducted on a CVCS DCS currently being used and refined at an existing U.S. nuclear power plant. Subject matter experts from process control engineering, software development, and human factors evaluated the DCS displays to document potential usability issues and propose design recommendations. The evaluation yielded 167 potential usability issues with the DCS. These issues should not be considered operator performance problems but rather opportunities

Taking account of human factors in control-room design

International Nuclear Information System (INIS)

Dien, Y.; Montmayeul, R.

1995-07-01

Since the Three Mile Island accident two ways for improving the Human-Machine Interface have mainly been followed: the development of computerized operator aids in existing control-rooms and the design of advanced control-rooms. Insufficient attention paid to human factors in the design of operator aids has generally led to these aids being neglected or unused by their potential users. While for the design of advanced control-rooms efforts have been made for dealing with human factors in more extensive way. Based upon this experience, a general method for taking account of human factors in a control-room design has been devised and is described in this paper. (author)

Method and apparatus for controlling gas evolution from chemical reactions

Science.gov (United States)

Skorpik, James R.; Dodson, Michael G.

1999-01-01

The present invention is directed toward monitoring a thermally driven gas evolving chemical reaction with an acoustic apparatus. Signals from the acoustic apparatus are used to control a heater to prevent a run-away condition. A digestion module in combination with a robotic arm further automate physical handling of sample material reaction vessels. The invention is especially useful for carrying out sample procedures defined in EPA Methods SW-846.

Comparative Studies of Physico-chemical Properties of Some ...

African Journals Online (AJOL)

Akorede

cement (As, Br, De and Sk) sold in Nigerian market using standard methods; due to the persistent collapse of buildings. ... important factors for chemical control in cement (Nasir and .... and mixed for 90s; this was allowed to stop at every 15s in.

Improvements to enforcement of multilateral environmental agreements to control international shipments of chemicals and wastes.

Science.gov (United States)

Liu, Ning; Somboon, Vira; Wun'gaeo, Surichai; Middleton, Carl; Tingsabadh, Charit; Limjirakan, Sangchan

2016-06-01

Illegal trade in hazardous waste and harmful chemicals has caused severe damage on human health and the environment, and brought big challenges to countries to meet their commitments to related multilateral environmental agreements. Synergy-building, like organising law enforcement operations, is critical to address illegal trade in waste and chemicals, and further improve the effectiveness of environmental enforcement. This article discusses how and why law enforcement operations can help countries to implement chemical and waste-related multilateral environmental agreements in a more efficient and effective way. The research explores key barriers and factors for organising law enforcement operations, and recommends methods to improve law enforcement operations to address illegal trade in hazardous waste and harmful chemicals. © The Author(s) 2016.

Modeling and control of diffusion and low-pressure chemical vapor deposition furnaces

Science.gov (United States)

De Waard, H.; De Koning, W. L.

1990-03-01

In this paper a study is made of the heat transfer inside cylindrical resistance diffusion and low-pressure chemical vapor deposition furnaces, aimed at developing an improved temperature controller. A model of the thermal behavior is derived which also covers the important class of furnaces equipped with semitransparent quartz process tubes. The model takes into account the thermal behavior of the thermocouples. It is shown that currently used temperature controllers are highly inefficient for very large scale integration applications. Based on the model an alternative temperature controller of the linear-quadratic-Gaussian type is proposed which features direct wafer temperature control. Some simulation results are given.

Chemical Control for Host-Parasitoid Model within the Parasitism Season and Its Complex Dynamics

Directory of Open Access Journals (Sweden)

Tao Wang

2016-01-01

Full Text Available In the present paper, we develop a host-parasitoid model with Holling type II functional response function and chemical control, which can be applied at any time of each parasitism season or pest generation, and focus on addressing the importance of the timing of application pesticide during the parasitism season or pest generation in successful pest control. Firstly, the existence and stability of both the host and parasitoid populations extinction equilibrium and parasitoid-free equilibrium have been investigated. Secondly, the effects of key parameters on the threshold conditions have been discussed in more detail, which shows the importance of pesticide application times on the pest control. Thirdly, the complex dynamics including multiple attractors coexistence, chaotic behavior, and initial sensitivity have been studied by using numerical bifurcation analyses. Finally, the uncertainty and sensitivity of all the parameters on the solutions of both the host and parasitoid populations are investigated, which can help us to determine the key parameters in designing the pest control strategy. The present research can help us to further understand the importance of timings of pesticide application in the pest control and to improve the classical chemical control and to make management decisions.

The complete information for phenomenal distributed parameter control of multicomponent chemical processes in gas, fluid and solid phase

International Nuclear Information System (INIS)

Niemiec, W.

1985-01-01

A constitutive mathematical model of distributed parameters of multicomponent chemical processes in gas, fluid and solid phase is utilized to the realization of phenomenal distributed parameter control of these processes. Original systems of partial differential constitutive state equations, in the following derivative forms /I/, /II/ and /III/ are solved in this paper from the point of view of information for phenomenal distributed parameter control of considered processes. Obtained in this way for multicomponent chemical processes in gas, fluid and solid phase: -dynamical working space-time characteristics/analytical solutions in working space-time of chemical reactors/, -dynamical phenomenal Green functions as working space-time transfer functions, -statical working space characteristics /analytical solutions in working space of chemical reactors/, -statical phenomenal Green functions as working space transfer functions, are applied, as information for realization of constitutive distributed parameter control of mass, energy and momentum aspects of above processes. Two cases are considered by existence of: A/sup o/ - initial conditions, B/sup o/ - initial and boundary conditions, for multicomponent chemical processes in gas, fluid and solid phase

Chemical Ecology of the Colorado Potato Beetle, Leptinotarsa decemlineata (Say (Coleoptera: Chrysomelidae, and Potential for Alternative Control Methods

Directory of Open Access Journals (Sweden)

François J. Verheggen

2012-12-01

Full Text Available The Colorado potato beetle (CPB has been a major insect pest to potato farming for over 150 years and various control methods have been established to reduce its impact on potato fields. Crop rotation and pesticide use are currently the most widely used approaches, although alternative methods are being developed. Here we review the role of various volatile and nonvolatile chemicals involved in behavior changes of CPB that may have potential for their control. First, we describe all volatile and nonvolatile chemicals involved in host plant localization and acceptance by CPB beetles, including glycoalcaloids and host plant volatiles used as kairomones. In the second section, we present the chemical signals used by CPB in intraspecific communication, including sex and aggregation pheromones. Some of these chemicals are used by natural enemies of CPBs to locate their prey and are presented in the third section. The last section of this review is devoted a discussion of the potential of some natural chemicals in biological control of CPB and to approaches that already reached efficient field applications.

Real-time nonlinear feedback control of pattern formation in (bio)chemical reaction-diffusion processes: a model study.

Science.gov (United States)

Brandt-Pollmann, U; Lebiedz, D; Diehl, M; Sager, S; Schlöder, J

2005-09-01

Theoretical and experimental studies related to manipulation of pattern formation in self-organizing reaction-diffusion processes by appropriate control stimuli become increasingly important both in chemical engineering and cellular biochemistry. In a model study, we demonstrate here exemplarily the application of an efficient nonlinear model predictive control (NMPC) algorithm to real-time optimal feedback control of pattern formation in a bacterial chemotaxis system modeled by nonlinear partial differential equations. The corresponding drift-diffusion model type is representative for many (bio)chemical systems involving nonlinear reaction dynamics and nonlinear diffusion. We show how the computed optimal feedback control strategy exploits the system inherent physical property of wave propagation to achieve desired control aims. We discuss various applications of our approach to optimal control of spatiotemporal dynamics.

History of EPI Suite™ and future perspectives on chemical property estimation in US Toxic Substances Control Act new chemical risk assessments.

Science.gov (United States)

Card, Marcella L; Gomez-Alvarez, Vicente; Lee, Wen-Hsiung; Lynch, David G; Orentas, Nerija S; Lee, Mari Titcombe; Wong, Edmund M; Boethling, Robert S

2017-03-22

Chemical property estimation is a key component in many industrial, academic, and regulatory activities, including in the risk assessment associated with the approximately 1000 new chemical pre-manufacture notices the United States Environmental Protection Agency (US EPA) receives annually. The US EPA evaluates fate, exposure and toxicity under the 1976 Toxic Substances Control Act (amended by the 2016 Frank R. Lautenberg Chemical Safety for the 21 st Century Act), which does not require test data with new chemical applications. Though the submission of data is not required, the US EPA has, over the past 40 years, occasionally received chemical-specific data with pre-manufacture notices. The US EPA has been actively using this and publicly available data to develop and refine predictive computerized models, most of which are housed in EPI Suite™, to estimate chemical properties used in the risk assessment of new chemicals. The US EPA develops and uses models based on (quantitative) structure-activity relationships ([Q]SARs) to estimate critical parameters. As in any evolving field, (Q)SARs have experienced successes, suffered failures, and responded to emerging trends. Correlations of a chemical structure with its properties or biological activity were first demonstrated in the late 19 th century and today have been encapsulated in a myriad of quantitative and qualitative SARs. The development and proliferation of the personal computer in the late 20 th century gave rise to a quickly increasing number of property estimation models, and continually improved computing power and connectivity among researchers via the internet are enabling the development of increasingly complex models.

Decay Accelerating Factor (CD55) Protects Neuronal Cells from Chemical Hypoxia-Induced Injury

Science.gov (United States)

2010-04-09

Pavlakovic G, Isom GE: Dopaminergic neurotoxicity of cyanide: neurochemical, histological and behavioral characterization. Toxicol Appl Pharmacol...provided the original work is properly cited. ResearchDecay accelerating factor (CD55) protects neuronal cells from chemical hypoxia-induced injury...deposition of C3a/C5a and membrane attack complex (MAC or C5b-9) production. The present study investigates the ability of DAF to protect primary cultured

Mercury transformations in resuspended contaminated sediment controlled by redox conditions, chemical speciation and sources of organic matter

Science.gov (United States)

Zhu, Wei; Song, Yu; Adediran, Gbotemi A.; Jiang, Tao; Reis, Ana T.; Pereira, Eduarda; Skyllberg, Ulf; Björn, Erik

2018-01-01

Mercury (Hg) contaminated sediments can be significant sources of Hg in aquatic ecosystems and, through re-emission processes, to the atmosphere. Transformation and release of Hg may be enhanced by various sediment perturbation processes, and controlling biogeochemical factors largely remain unclear. We investigated how rates of Hg transformations in pulp-fiber enriched sediment contaminated by Hg from chlor-alkali industry were controlled by (i) transient redox-changes in sulfur and iron chemistry, (ii) the chemical speciation and solubility of Hg, and (iii) the sources and characteristics of organic matter (OM). Sediment-bottom water microcosm systems were exposed to four combinations of air and nitrogen gas for a total time of 24 h. The treatments were: 24 h N2, 0.5 h air + 23.5 h N2, 4 h air + 20 h N2 and 24 h of air exposure. As a result of these treatments, microcosms spanned a wide range of redox potential, as reflected by the dissolved sulfide concentration range of ≤0.3-97 μM. Four different chemical species of inorganic divalent Hg (HgII) and methyl mercury (MeHg), enriched in different Hg isotope tracers, were added to the microcosms: 201Hg(NO3)2(aq), 202HgII adsorbed to OM (202HgII-OM(ads)), 198HgII as microcrystalline metacinnabar (β-198HgS(s)) and Me204HgCl(aq). Microcosm systems were composed of bottom water mixed with sediment taken at 0-2, 0-5 and 0-10 cm depth intervals. The composition of OM varied with sediment depth such that compared to deeper sediment, the 0-2 cm depth-interval had a 2-fold higher contribution of labile OM originating from algal and terrestrial inputs, serving as metabolic electron-donors for microorganisms. The potential methylation rate constant (kmeth) of Hg tracers and net formation of ambient MeHg (MeHg/THg molar ratio) increased up to 50% and 400%, respectively at intermediate oxidative conditions, likely because of an observed 2-fold increase in sulfate concentration stimulating the activity of sulfate reducing

Controlling “chemical nose” biosensor characteristics by modulating gold nanoparticle shape and concentration

Directory of Open Access Journals (Sweden)

Mohit S. Verma

2015-09-01

Full Text Available Conventional lock-and-key biosensors often only detect a single pathogen because they incorporate biomolecules with high specificity. “Chemical nose” biosensors are overcoming this limitation and identifying multiple pathogens simultaneously by obtaining a unique set of responses for each pathogen of interest, but the number of pathogens that can be distinguished is limited by the number of responses obtained. Herein, we use a gold nanoparticle-based “chemical nose” to show that changing the shapes of nanoparticles can increase the number of responses available for analysis and expand the types of bacteria that can be identified. Using four shapes of nanoparticles (nanospheres, nanostars, nanocubes, and nanorods, we demonstrate that each shape provides a unique set of responses in the presence of different bacteria, which can be exploited for enhanced specificity of the biosensor. Additionally, the concentration of nanoparticles controls the detection limit of the biosensor, where a lower concentration provides better detection limit. Thus, here we lay a foundation for designing “chemical nose” biosensors and controlling their characteristics using gold nanoparticle morphology and concentration. Keywords: Morphology, Color change, Staphylococcus aureus, Point-of-care, Nanocubes, Nanorods

Defect-engineered graphene chemical sensors with ultrahigh sensitivity.

Science.gov (United States)

Lee, Geonyeop; Yang, Gwangseok; Cho, Ara; Han, Jeong Woo; Kim, Jihyun

2016-05-25

We report defect-engineered graphene chemical sensors with ultrahigh sensitivity (e.g., 33% improvement in NO2 sensing and 614% improvement in NH3 sensing). A conventional reactive ion etching system was used to introduce the defects in a controlled manner. The sensitivity of graphene-based chemical sensors increased with increasing defect density until the vacancy-dominant region was reached. In addition, the mechanism of gas sensing was systematically investigated via experiments and density functional theory calculations, which indicated that the vacancy defect is a major contributing factor to the enhanced sensitivity. This study revealed that defect engineering in graphene has significant potential for fabricating ultra-sensitive graphene chemical sensors.

Chemical analysis and quality control of Ginkgo biloba leaves, extracts, and phytopharmaceuticals

NARCIS (Netherlands)

Beek, van T.A.; Montoro, P.

2009-01-01

The chemical analysis and quality control of Ginkgo leaves, extracts, phytopharmaceuticals and some herbal supplements is comprehensively reviewed. The review is an update of a similar, earlier review in this journal [T.A. van Beek, J. Chromatogr. A 967 (2002) 21¿55]. Since 2001 over 3000 papers on

Use of direct washing of chemical dispense nozzle for defect control

Science.gov (United States)

Linnane, Michael; Mack, George; Longstaff, Christopher; Winter, Thomas

2006-03-01

Demands for continued defect reduction in 300mm IC manufacturing are driving process engineers to examine all aspects of the chemical apply process for improvement. Historically, the defect contribution from photoresist apply nozzles has been minimized through a carefully controlled process of "dummy dispenses" to keep the photoresist in the tip "fresh" and remove any solidified material, a preventive maintenance regime involving periodic cleaning or replacing of the nozzles, and reliance on a pool of solvent within the nozzle storage block to keep the photoresist from solidifying at the nozzle tip. The industry standard has worked well for the most part but has limitations in terms of cost effectiveness and absolute defect elimination. In this study, we investigate the direct washing of the chemical apply nozzle to reduce defects seen on the coated wafer. Data is presented on how the direct washing of the chemical dispense nozzle can be used to reduce coating related defects, reduce material costs from the reduction of "dummy dispense", and can reduce equipment downtime related to nozzle cleaning or replacement.

Can Chemical Mouthwash Agents Achieve Plaque/Gingivitis Control?

Science.gov (United States)

Van der Weijden, Fridus A; Van der Sluijs, Eveline; Ciancio, Sebastian G; Slot, Dagmar E

2015-10-01

Also note that structured abstracts are not allowed per journal style: What is the effect of a mouthwash containing various active chemical ingredients on plaque control and managing gingivitis in adults based on evidence gathered from existing systematic reviews? The summarized evidence suggests that mouthwashes containing chlorhexidine(CHX) and essential oils (EO) had a large effect supported by a strong body of evidence. Also there was strong evidence for a moderate effect of cetylpyridinium chloride(CPC). Evidence suggests that a CHX mouthwash is the first choice, the most reliable alternative is EO. No difference between CHX and EO with respect to gingivitis was observed. Copyright © 2015 Elsevier Inc. All rights reserved.

Economic Benefit from Progressive Integration of Scheduling and Control for Continuous Chemical Processes

Directory of Open Access Journals (Sweden)

Logan D. R. Beal

2017-12-01

Full Text Available Performance of integrated production scheduling and advanced process control with disturbances is summarized and reviewed with four progressive stages of scheduling and control integration and responsiveness to disturbances: open-loop segregated scheduling and control, closed-loop segregated scheduling and control, open-loop scheduling with consideration of process dynamics, and closed-loop integrated scheduling and control responsive to process disturbances and market fluctuations. Progressive economic benefit from dynamic rescheduling and integrating scheduling and control is shown on a continuously stirred tank reactor (CSTR benchmark application in closed-loop simulations over 24 h. A fixed horizon integrated scheduling and control formulation for multi-product, continuous chemical processes is utilized, in which nonlinear model predictive control (NMPC and continuous-time scheduling are combined.

Production of chemical substances in Tajikistan

International Nuclear Information System (INIS)

Boboev, Kh.E.; Nazarov, K.M.

2010-01-01

Full text: Government of the Republic of Tajikistan has signed Convention "On prohibition of chemical weapon application"and no chemical weapon (CHW) is produced on the territory of republic. However, the potential production of CHW by individual persons or groups can be organized, using available production and obtaining chemical substances from other countries. Chemical substances, which have strong damage effect, easily, can be synthesized in chemical laboratories. These are general toxic substances, as hydrocyanic acid acid, phosgene, mustard gas, lewisite, sarin and others. The similar chemical substances of industrial significance are produced in Tajikistan: ammonia, chlorine, explosives, caustic soda, carbamide, formaldehyde and others. For industrial needs and agriculture from other countries Tajikistan is receiving the following: sodium cyanide and potassium for gold-mining; mineral acids; pesticides and others. Besides, there are different deposits in Tajikistan, reprocessing of which gives an opportunity to obtain different chemical substances. What can be obtained from chemicals produced in Tajikistan? Chlorine - from this reagent the fluoride chlorine, phosgene COCl_2 and many other compounds are easily synthesized, which are CHW components. Obtained cyanic compounds for gold mining can be used as precursor for neuroparalytic action. A big amount of metallic aluminum is produced in the republic. The Al powder for rocket fuel can be obtained from it. Obtained from other countries pesticides are potential components for CHW creation. A strong control and account of pesticides use is necessary. It is extremely important to control materials, equipment and technologies which allow countries and separate groups to create weapons of mass destruction (WMD). The most important factor is goods identification. Firstly - inspection of external view, labeling, packing specifications, license availability and etc. Strong control of checklists is necessary according

76 FR 38169 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data

Science.gov (United States)

2011-06-29

... (7405M), Office of Pollution Prevention and Toxics, Environmental Protection Agency, 1200 Pennsylvania... gold leaf, dyeing mixtures, antifreeze mixtures, extraction of resins and waxes, preservative for...: June 21, 2011. Maria J. Doa, Director, Chemical Control Division, Office of Pollution Prevention and...

[Current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry].

Science.gov (United States)

Wu, S S; Yu, J N; He, C H; Mu, H X; Wang, C; Zhang, Y; Zhang, C Y; Yu, S F; Li, X L

2016-12-20

Objective: To investigate the current status of hearing loss and related influencing factors in workers with noise exposure in refining and chemical industry. Methods: From August 2015 to March 2016, the investigation method of collecting the data of past occupational health examinations and measuring noise in working environment was used to enroll 8 672 male workers. Results: Of all workers, 11.6% were diagnosed with hearing loss. There were significant differences in the distribution of hearing impairment among workers exposed to noise at different ages, device types and types of work (χ(2)=17.80, 77.80 and 30.53, all P hearing loss in workers with noise exposure in refining and chemical industry. Conclusion: The level of noise exposure and working years with noise exposure are main influencing factors for hearing loss in workers with noise exposure in refining and chemical industry.

An electrochemical study of natural and chemically controlled eumelanin

Science.gov (United States)

Xu, Ri; Prontera, Carmela Tania; Di Mauro, Eduardo; Pezzella, Alessandro; Soavi, Francesca; Santato, Clara

2017-12-01

Eumelanin is the most common form of the pigment melanin in the human body, with functions including antioxidant behavior, metal chelation, and free radical scavenging. This biopigment is of interest for biologically derived batteries and supercapacitors. In this work, we characterized the voltammetric properties of chemically controlled eumelanins produced from 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA) building blocks, namely, DHI-melanin, DHICA-melanin, and natural eumelanin, extracted from the ink sac of cuttlefish, Sepia melanin. Eumelanin electrodes were studied for their cyclic voltammetric properties in acidic buffers including Na+, K+, NH4+, and Cu2+ ions.

Impact of a low intensity controlled-fire in some chemical soil properties.

Science.gov (United States)

Martínez-Murillo, Juan F.; Hueso-González, Paloma; Aranda-Gómez, Francisco; Damián Ruiz-Sinoga, José

2014-05-01

Some changes in chemical soil properties can be observed after fires of low intensities. pH and electric conductivity tend to increase, while C/N ratio decrease. In the case of organic matter, the content can increase due to the massive incorporation of necromass including, especially, plants and roots. The aim of this study is to assess the impact of low intensity and controlled fire in some soil properties in field conditions. El Pinarillo experimental area is located in South of Spain. Two set of closed plots were installed (24 m2: 12 m length x 2 m width). One of them was remained as control with the original vegetation cover (Mediterranean matorral: Rosmarinus officinalis, Cistus clusii, Lavandula stoechas, Chamaeropos humilis, Thymus baetica), and the other one was burnt in a controlled-fire in 2011. Weather conditions and water content of vegetation influenced in the intensity of fire (low). After the controlled-fire, soil surface sample (0-5 cm) were taken in both set of plots (B, burnt soil samples; C, control soil samples). Some soil chemical properties were analysed: organic matter content (OM), C/N ratio, pH and electrical conductivity (EC). Some changes were observed in B corroborating a controlled-fire of low intensity. pH remained equal after fire (B: pH=7.7±0.11; C: pH=7.7±0.04). An increment was obtained in the case of EC (B: EC=0.45 mScm-1±0.08 mScm-1; C: EC=0.35 mScm-1±0.07 mScm-1) and OM (B: OM=8.7%±3.8%; C: pH=7.3%±1.5%). Finally, C/N ratio decreased after fire respect to the control and initial conditions (B: C/N=39.0±14.6; C: C/N =46.5±10.2).

Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system

International Nuclear Information System (INIS)

El Kanawati, W.; Perot, B.; Carasco, C.; Eleon, C.; Valkovic, V.; Sudac, D.; Obhodas, J.

2011-01-01

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the 3 H(d,n) 4 H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs.

Conversion factors from counts to chemical ratios for the EURITRACK tagged neutron inspection system

Energy Technology Data Exchange (ETDEWEB)

El Kanawati, W. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Perot, B., E-mail: bertrand.perot@cea.fr [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Carasco, C.; Eleon, C. [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France); Valkovic, V. [A.C.T.d.o.o., Prilesje 4, 10000 Zagreb (Croatia); Sudac, D.; Obhodas, J. [Ruder Boskovic Institute, Bijenicka c. 54, 10000 Zagreb (Croatia)

2011-10-21

The EURopean Illicit TRAfficking Countermeasures Kit (EURITRACK) uses 14 MeV neutrons produced by the {sup 3}H(d,n){sup 4}H fusion reaction to detect explosives and narcotics in cargo containers. Reactions induced by fast neutrons produce gamma rays, which are detected in coincidence with the associated alpha particle to determine the neutron direction. In addition, the neutron path length is obtained from a time-of-flight measurement, thus allowing the origin of the gamma rays inside the container to be determined. Information concerning the chemical composition of the target material is obtained from the analysis of the energy spectrum. The carbon, oxygen, and nitrogen relative count contributions must be converted to chemical proportions to distinguish illicit and benign organic materials. An extensive set of conversion factors based on Monte Carlo numerical simulations has been calculated, taking into account neutron slowing down and photon attenuation in the cargo materials. An experimental validation of the method is presented by comparing the measured chemical fractions of known materials, in the form of bare samples or hidden in a cargo container, to their real chemical composition. Examples of application to real cargo containers are also reported, as well as simulated data with explosives and illicit drugs.

Thermally activated reaction–diffusion-controlled chemical bulk reactions of gases and solids

Directory of Open Access Journals (Sweden)

S. Möller

2015-01-01

Full Text Available The chemical kinetics of the reaction of thin films with reactive gases is investigated. The removal of thin films using thermally activated solid–gas to gas reactions is a method to in-situ control deposition inventory in vacuum and plasma vessels. Significant scatter of experimental deposit removal rates at apparently similar conditions was observed in the past, highlighting the need for understanding the underlying processes. A model based on the presence of reactive gas in the films bulk and chemical kinetics is presented. The model describes the diffusion of reactive gas into the film and its chemical interaction with film constituents in the bulk using a stationary reaction–diffusion equation. This yields the reactive gas concentration and reaction rates. Diffusion and reaction rate limitations are depicted in parameter studies. Comparison with literature data on tokamak co-deposit removal results in good agreement of removal rates as a function of pressure, film thickness and temperature.

Traceability and Quality Control in Traditional Chinese Medicine: From Chemical Fingerprint to Two-Dimensional Barcode

Directory of Open Access Journals (Sweden)

Yong Cai

2015-01-01

Full Text Available Chemical fingerprinting is currently a widely used tool that enables rapid and accurate quality evaluation of Traditional Chinese Medicine (TCM. However, chemical fingerprints are not amenable to information storage, recognition, and retrieval, which limit their use in Chinese medicine traceability. In this study, samples of three kinds of Chinese medicines were randomly selected and chemical fingerprints were then constructed by using high performance liquid chromatography. Based on chemical data, the process of converting the TCM chemical fingerprint into two-dimensional code is presented; preprocess and filtering algorithm are also proposed aiming at standardizing the large amount of original raw data. In order to know which type of two-dimensional code (2D is suitable for storing data of chemical fingerprints, current popular types of 2D codes are analyzed and compared. Results show that QR Code is suitable for recording the TCM chemical fingerprint. The fingerprint information of TCM can be converted into data format that can be stored as 2D code for traceability and quality control.

Data acquisition and control system with a programmable logic controller (PLC) for a pulsed chemical oxygen-iodine laser

Science.gov (United States)

Yu, Haijun; Li, Guofu; Duo, Liping; Jin, Yuqi; Wang, Jian; Sang, Fengting; Kang, Yuanfu; Li, Liucheng; Wang, Yuanhu; Tang, Shukai; Yu, Hongliang

2015-02-01

A user-friendly data acquisition and control system (DACS) for a pulsed chemical oxygen -iodine laser (PCOIL) has been developed. It is implemented by an industrial control computer，a PLC, and a distributed input/output (I/O) module, as well as the valve and transmitter. The system is capable of handling 200 analogue/digital channels for performing various operations such as on-line acquisition, display, safety measures and control of various valves. These operations are controlled either by control switches configured on a PC while not running or by a pre-determined sequence or timings during the run. The system is capable of real-time acquisition and on-line estimation of important diagnostic parameters for optimization of a PCOIL. The DACS system has been programmed using software programmable logic controller (PLC). Using this DACS, more than 200 runs were given performed successfully.

Statistical process control support during Defense Waste Processing Facility chemical runs

International Nuclear Information System (INIS)

Brown, K.G.

1994-01-01

The Product Composition Control System (PCCS) has been developed to ensure that the wasteforms produced by the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS) will satisfy the regulatory and processing criteria that will be imposed. The PCCS provides rigorous, statistically-defensible management of a noisy, multivariate system subject to multiple constraints. The system has been successfully tested and has been used to control the production of the first two melter feed batches during DWPF Chemical Runs. These operations will demonstrate the viability of the DWPF process. This paper provides a brief discussion of the technical foundation for the statistical process control algorithms incorporated into PCCS, and describes the results obtained and lessons learned from DWPF Cold Chemical Run operations. The DWPF will immobilize approximately 130 million liters of high-level nuclear waste currently stored at the Site in 51 carbon steel tanks. Waste handling operations separate this waste into highly radioactive sludge and precipitate streams and less radioactive water soluble salts. (In a separate facility, soluble salts are disposed of as low-level waste in a mixture of cement slag, and flyash.) In DWPF, the precipitate steam (Precipitate Hydrolysis Aqueous or PHA) is blended with the insoluble sludge and ground glass frit to produce melter feed slurry which is continuously fed to the DWPF melter. The melter produces a molten borosilicate glass which is poured into stainless steel canisters for cooling and, ultimately, shipment to and storage in a geologic repository

Chemical quality of different argentine honey varieties, irradiated to control american foulbrood

International Nuclear Information System (INIS)

Zunich, C.D.; Markowski, I.; Narvaiz, Patricia

2011-01-01

'American foulbrood' is a disease that seriously affects bees. Honey may be contaminated with spores of the related bacteria, Paenibacillus larvae larvae, which is a great drawback for trade. The scientific literature reports that these spores, resistant to heat and chemicals, are inactivated in honey when it is irradiated al 10 kGy, being this treatment mandatory in the Republic of Southafrica. Irradiated food wholesomeness is endorsed by the World Health Organization. Considering that Argentina is an important honey producer and exporter, the aim of this work was to evaluate the effect of ionizing radiation on some of its commercial chemical parameters along storage time. Honeys with different characteristics, coming from five different regions of the country: Middle, Patagonia, North, Litoral, Humid Pampa, were provided by producers from a commission called 'Packaged honey' of the National Food, Fishery and Agriculture Ministry. Fifteen kg of each honey variety were packaged in 500 g polypropylene recipes with polyethylene lids, and irradiated at the semi industrial cobalt-60 facility of the Ezeiza Atomic Center, 500,000 Ci of activity, with doses of 0, 10 and 20 kilo Grays. Control and irradiated samples were stored at room temperature for 10 months. Some standardized chemical analysis required by the Argentine Food Code (AFC) were performed on the first, fourth and tenth storage months: water content, acidity, diastase content, reducing sugars, and hydroxymethylfurfural. Reducing sugars and diastase activity slightly diminished, and acidity slightly increased, along storage which is typical in this product; no significant differences were found between control and irradiated samples. Hydroxymethylfurfural values, related to aging or thermal abuse, diminished slightly though significantly due to irradiation, which would not affect the product quality as regulations require not to surpass a maximum value, 40 mg/kg in the AFC. So ionizing

Control of neuronal network organization by chemical surface functionalization of multi-walled carbon nanotube arrays

International Nuclear Information System (INIS)

Liu Jie; Bibari, Olivier; Marchand, Gilles; Benabid, Alim-Louis; Sauter-Starace, Fabien; Appaix, Florence; De Waard, Michel

2011-01-01

Carbon nanotube substrates are promising candidates for biological applications and devices. Interfacing of these carbon nanotubes with neurons can be controlled by chemical modifications. In this study, we investigated how chemical surface functionalization of multi-walled carbon nanotube arrays (MWNT-A) influences neuronal adhesion and network organization. Functionalization of MWNT-A dramatically modifies the length of neurite fascicles, cluster inter-connection success rate, and the percentage of neurites that escape from the clusters. We propose that chemical functionalization represents a method of choice for developing applications in which neuronal patterning on MWNT-A substrates is required.

Control of neuronal network organization by chemical surface functionalization of multi-walled carbon nanotube arrays

Energy Technology Data Exchange (ETDEWEB)

Liu Jie; Bibari, Olivier; Marchand, Gilles; Benabid, Alim-Louis; Sauter-Starace, Fabien [CEA, LETI-Minatec, 17 Rue des Martyrs, 38054 Grenoble Cedex 9 (France); Appaix, Florence; De Waard, Michel, E-mail: fabien.sauter@cea.fr, E-mail: michel.dewaard@ujf-grenoble.fr [Inserm U836, Grenoble Institute of Neuroscience, Site Sante la Tronche, Batiment Edmond J Safra, Chemin Fortune Ferrini, BP170, 38042 Grenoble Cedex 09 (France)

2011-05-13

Carbon nanotube substrates are promising candidates for biological applications and devices. Interfacing of these carbon nanotubes with neurons can be controlled by chemical modifications. In this study, we investigated how chemical surface functionalization of multi-walled carbon nanotube arrays (MWNT-A) influences neuronal adhesion and network organization. Functionalization of MWNT-A dramatically modifies the length of neurite fascicles, cluster inter-connection success rate, and the percentage of neurites that escape from the clusters. We propose that chemical functionalization represents a method of choice for developing applications in which neuronal patterning on MWNT-A substrates is required.

Factors Affecting Exocellular Polysaccharide Production by Lactobacillus delbrueckii subsp. bulgaricus Grown in a Chemically Defined Medium†

Science.gov (United States)

Petry, Sandrine; Furlan, Sylviane; Crepeau, Marie-Jeanne; Cerning, Jutta; Desmazeaud, Michel

2000-01-01

We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains of Lactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp. bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricus CNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricus strains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production. PMID:10919802

Model-Based Integrated Process Design and Controller Design of Chemical Processes

DEFF Research Database (Denmark)

Abd Hamid, Mohd Kamaruddin Bin

that is typically formulated as a mathematical programming (optimization with constraints) problem is solved by the so-called reverse approach by decomposing it into four sequential hierarchical sub-problems: (i) pre-analysis, (ii) design analysis, (iii) controller design analysis, and (iv) final selection......This thesis describes the development and application of a new systematic modelbased methodology for performing integrated process design and controller design (IPDC) of chemical processes. The new methodology is simple to apply, easy to visualize and efficient to solve. Here, the IPDC problem...... are ordered according to the defined performance criteria (objective function). The final selected design is then verified through rigorous simulation. In the pre-analysis sub-problem, the concepts of attainable region and driving force are used to locate the optimal process-controller design solution...

Factors Controlling Nitrogen Fluxes in Groundwater in Agricultural Areas

Science.gov (United States)

Liao, L.; Green, C. T.; Bekins, B. A.; Bohlke, J. K.

2010-12-01

Predictions of effects of land use changes on water quality require identification of the relative importance of geochemical and hydrologic factors. To understand the factors controlling the transport of nitrogen in groundwater, vertical fluxes of water and solutes were estimated for 13 aquifers in agricultural areas located in California, Iowa, Maryland, Minnesota, Mississippi, Nebraska, North Carolina, Texas, and Wisconsin. The aquifers are overlain by unsaturated zones with thicknesses ranging from 2.5 to 100 m. Precipitation ranges from 19 to 132 cm/yr and irrigation ranges from 0 to 120 cm/yr. Main crop types include corn, soybeans, forage, wheat, and cotton. A 1-dimensional mathematical model was developed to estimate vertical N transport in response to N inputs on the land surface from chemical fertilizer, manure and atmospheric deposition. Simulated vertical profiles of O2, NO3-, N2 from denitrification, Cl- and atmospheric age tracers were matched to observations by adjusting parameters for recharge rate, unsaturated zone travel time, N leaching ratio (defined as leaching fraction of N reaching water table of N input at land surface), Cl- leaching ratio, O2 reduction rate and denitrification rate. Results indicated that vertical NO3 fluxes below the water table were affected by both geochemical and physical factors. High vertical NO3 fluxes below the water table are associated with high N input at the land surface. Values of Cl- leaching ratios were less than 1 (0.42 to 1) likely as a result of runoff and exported harvested crops. N leaching ratios were lower (0.1 to 0.6), consistent with additional N losses such as denitrification and volatilization. The sites with high leaching ratios for both N and Cl tended to be those with high recharge rates and low ET loss, defined as the fraction of applied water lost to ET. Modeled zero-order denitrification rates in the saturated zone varied within an order of magnitude with a maximum rate of 1.6 mg

Evaluation of Chemical and Physical-morphological Factors as Potential Determinants of Biomphalaria pfeifferi (Krauss, 1848 Distribution

Directory of Open Access Journals (Sweden)

Utzinger Jürg

1997-01-01

Full Text Available This study was carried out in five sites along a small perennial river system in south-central Tanzania, which had been identified as the focus for transmission of intestinal schistosomiasis in the area. Malacological surveys preceding the study showed a focal distribution of Biomphalaria pfeifferi, intermediate host snail of Schistosoma mansoni, the snails being present in three sites but absent from the other two sites. The objective of this study was to evaluate to what extent chemical and/or physical-morphological factors determine the distribution of B. pfeifferi between these five sites. It was found that none of the chemical constituents in the waters examined were outside the tolerance range of B. pfeifferi snails. Moreover, the composition of water from B. pfeifferi-free sites was not different from that in those sites where snails occurred. Furthermore, none of the physical-morphological constituents seemed likely to be a determinant for the absence of B. pfeifferi. In view of these findings, and those of previous studies, it is concluded that the focal distribution of B. pfeifferi cannot be associated with a single environmental factor and is rather the result of more complex interactions of habitat factors

Analysis of radiation and chemical factors which define the ecological situation of environment

International Nuclear Information System (INIS)

Trofimenko, A.P.

1996-01-01

A new method of large information set statistical analysis is proposed. It permits to define the main directions of work in a given field in the world or in a particular country, to find the most important investigated problems and to evaluate the role each of them quantitatively, as well as to study the dynamics of work development in time, the methods of research used, the centres in which this research is mostly developed, authors of publications etc. Statistical analysis may be supplemented with subject analysis of selected publications. Main factors which influence on different environment components and on public health are presented as an example of this method use, and the role of radiation and chemical factors is evaluated. 18 refs., 6 tab

Controlled growth of epitaxial CeO2 thin films with self-organized nanostructure by chemical solution method

DEFF Research Database (Denmark)

Yue, Zhao; Grivel, Jean-Claude

2013-01-01

Chemical solution deposition is a versatile technique to grow oxide thin films with self-organized nanostructures. Morphology and crystallographic orientation control of CeO2 thin films grown on technical NiW substrates by a chemical solution deposition method are achieved in this work. Based...

Physical and chemical factors influencing radionuclide behaviour in arable soils

International Nuclear Information System (INIS)

Rauret, G.; Vidal, M.; Alexakhin, R.M.; Kruglov, S.V.; Cremers, A.; Wauters, J.; Valcke, E.; Ivanov, Y.

1996-01-01

Soil-to-plant transfer of radionuclides integrates plant physiological and soil chemical aspects. Therefore, it is necessary to study the factors affecting the equilibrium of the radionuclides between solid and soil solution phases. Desorption and adsorption studies were applied to the podsolic and peat soils considered in the ECP-2 project. In the desorption approach, both sequential extraction and 'infinite bath' techniques were used. In the adsorption approach, efforts were directed at predicting Cs and Sr-K D on the basis of soil properties and soil solution composition. Desorption approach predicts time-dynamics of transfer with time but it is un sufficient for comparatively predicting transfer. Adsorption studies informs about which are the key factors affecting radionuclide transfer. For Sr, availability depends on the CEC and on the concentration of the Ca + Mg in the soil solution. For Cs, availability is mainly dependent on the partitioning between FES -frayed edge sites-, which are highly specific and REC -regular exchange complex-, with low selectivity for Cs. Moreover, availability depends on the K and NH 4 , levels in the soil solution and fixation properties of the soil. Considering these factors, the calculation of the in situ K D values helps to predict the relative transfer of radionuclides. The calculation of the K D of the materials that could be used as countermeasures could permit the prediction of its suitability to decrease transfer and therefore to help in producing cleaner agricultural products

An approach to quantitate and control the mutagenic hazards of environmental chemical and radioactive pollutants

International Nuclear Information System (INIS)

Murthy, M.S.S.

1977-01-01

Human population, both at the occupational and non-occupational levels, is exposed to the environment polluted by man-made chemicals and radiation sources. The parameters required for quantitating mutagenic hazards of any agent are listed and it has been pointed out that though sufficient information of this nature is available in the case of radiations, it is almost impossible to collect similar information for chemical substances due to their number running into astronomical figures. A short-cut approach, therefore, is suggested to quantitate and control the mutagenic hazards of these pollutants. It is to express the mutagenic hazards of a chemical substance in terms of equivalent radiation units. The unit proposed for this purpose is called as Rem-Equivalent Chemical (REC). Total mutagenic burden to the society should take account of exposure from both chemicals and radiations. Advantages and limitation of this approach are discussed. (M.G.B.)

Ab initio study of electron-ion structure factors in binary liquids with different types of chemical bonding

International Nuclear Information System (INIS)

Klevets, Ivan; Bryk, Taras

2014-01-01

Electron-ion structure factors, calculated in ab initio molecular dynamics simulations, are reported for several binary liquids with different kinds of chemical bonding: metallic liquid alloy Bi–Pb, molten salt RbF, and liquid water. We derive analytical expressions for the long-wavelength asymptotes of the partial electron-ion structure factors of binary systems and show that the analytical results are in good agreement with the ab initio simulation data. The long-wavelength behaviour of the total charge structure factors for the three binary liquids is discussed

Report: EPA Should Assess Needs and Implement Management Controls to Ensure Effective Incorporation of Chemical Safety Research Products

Science.gov (United States)

Report #17-P-0294, June 23, 2017. With management controls that ensure the collaborative development of research products and prioritize chemical safety research needs, the EPA would be better able to conduct faster chemical risk assessments.

An electrochemical study of natural and chemically controlled eumelanin

Directory of Open Access Journals (Sweden)

Ri Xu

2017-12-01

Full Text Available Eumelanin is the most common form of the pigment melanin in the human body, with functions including antioxidant behavior, metal chelation, and free radical scavenging. This biopigment is of interest for biologically derived batteries and supercapacitors. In this work, we characterized the voltammetric properties of chemically controlled eumelanins produced from 5,6-dihydroxyindole (DHI and 5,6-dihydroxyindole-2-carboxylic acid (DHICA building blocks, namely, DHI-melanin, DHICA-melanin, and natural eumelanin, extracted from the ink sac of cuttlefish, Sepia melanin. Eumelanin electrodes were studied for their cyclic voltammetric properties in acidic buffers including Na+, K+, NH4+, and Cu2+ ions.

Phase distribution of ecologically controlled chemical elements in production of extraction phosphoric acid

International Nuclear Information System (INIS)

Kazak, V.G.; Agnelov, A.I.; Zajtsev, P.M.

1995-01-01

Content of 16 ecologically controlled chemical element (among them Cd, Sr, Th, U, V, Y) in solid and liquid phases of extraction phosphorus acid (EPA) production is determined. These elements are recommended to control by Scientific research institute of human ecology and environment to establish their extraction coefficients to phosphogypsum and EPA and optimal variant of production of ecologically sate phosphorus fertilizers. X-ray fluorescent, atomic-absorption and polarographic methods are used for analysis these elements

SALE, Quality Control of Analytical Chemical Measurements

International Nuclear Information System (INIS)

Bush, W.J.; Gentillon, C.D.

1985-01-01

1 - Description of problem or function: The Safeguards Analytical Laboratory Evaluation (SALE) program is a statistical analysis program written to analyze the data received from laboratories participating in the SALE quality control and evaluation program. The system is aimed at identifying and reducing analytical chemical measurement errors. Samples of well-characterized materials are distributed to laboratory participants at periodic intervals for determination of uranium or plutonium concentration and isotopic distributions. The results of these determinations are statistically evaluated and participants are informed of the accuracy and precision of their results. 2 - Method of solution: Various statistical techniques produce the SALE output. Assuming an unbalanced nested design, an analysis of variance is performed, resulting in a test of significance for time and analyst effects. A trend test is performed. Both within- laboratory and between-laboratory standard deviations are calculated. 3 - Restrictions on the complexity of the problem: Up to 1500 pieces of data for each nuclear material sampled by a maximum of 75 laboratories may be analyzed

PMBLDC motor drive with power factor correction controller

DEFF Research Database (Denmark)

George, G.J.; Ramachandran, Rakesh; Arun, N.

2012-01-01

reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase...

FACTORS INFLUENCING ORGANIZATIONAL STRUCTURE IN THE FOOD MANUFACTURING, CHEMICAL, AGRICULTURAL WHOLESALING AND BIOTECHNOLOGY INDUSTRIES

OpenAIRE

Maude Roucan-Kane

2009-01-01

The objective of this study is to identify factors determining a business investment strategy (i.e., the choice of investment commitment and form of organizational structure) in the food manufacturing, chemical, agricultural wholesaling and biotechnology industries. Propositions regarding strategic alliance theories are tested on over 400 inter-firm collaborative agreements using secondary data from major US and European companies for the 1994-97 period. Results suggest that transactions with...

A Self-Calibrating Remote Control Chemical Monitoring System

Energy Technology Data Exchange (ETDEWEB)

Jessica Croft

2007-06-01

The Susie Mine, part of the Upper Tenmile Mining Area, is located in Rimini, MT about 15 miles southwest of Helena, MT. The Upper Tenmile Creek Mining Area is an EPA Superfund site with 70 abandoned hard rock mines and several residential yards prioritized for clean up. Water from the Susie mine flows into Tenmile Creek from which the city of Helena draws part of its water supply. MSE Technology Applications in Butte, Montana was contracted by the EPA to build a treatment system for the Susie mine effluent and demonstrate a system capable of treating mine waste water in remote locations. The Idaho National Lab was contracted to design, build and demonstrate a low maintenance self-calibrating monitoring system that would monitor multiple sample points, allow remote two-way communications with the control software and allow access to the collected data through a web site. The Automated Chemical Analysis Monitoring (ACAM) system was installed in December 2006. This thesis documents the overall design of the hardware, control software and website, the data collected while MSE-TA’s system was operational, the data collected after MSE-TA’s system was shut down and suggested improvements to the existing system.

Control charts technique - a tool to data analysis for chemical experiments

International Nuclear Information System (INIS)

Yadav, M.B.; Venugopal, V.

1999-01-01

A procedure using control charts technique has been developed to analyse data of a chemical experiment which was conducted to assign a value to uranium content in Rb 2 U(SO 4 ) 3 . A value of (34.164 ± 0.031)% has been assigned against (34.167 ± 0.042)% already assigned by analysis of variance (ANOVA) technique. These values do not differ significantly. Merits and demerits of the two techniques have been discussed. (author)

Developing ecotoxicological testing procedures for chemicals in soils

International Nuclear Information System (INIS)

Scheunert, I.; Doerfler, U.; Quast, I.; Schroll, R.; Topp, E.; Wolf, E.; Korte, F.

1989-01-01

The work deals with the determination of adsorption coefficients of volatile environmental chemicals, of volatilization rates (example: Lindane), biomineralization rates, total balances, and uptake into higher plants, further with the correlation of the uptake of chemicals by plants with physico-chemical and structural mass characteristics, and field experiments with lysimeters using labelled carbon 14 compounds for validation of the results obtained under laboratory conditions. - The devices for determination of adsorption coefficients and of volatilization rates of chemicals from soil and plant surfaces, as well as the closed experimental setup with controlled air throughput for billing labelled carbon 14 chemicals in the soil/plant system are described. The mass balance of the adsorption of volatile labelled carbon 14 chemicals in an alfisol, the volatilization of Lindane from the surface of a sandy soil, the concentration of hexachlorbenzene in different parts of plants, the uptake pathways of organic chemicals in higher plants and their corelation with mass properties, as well as the correlation between bioconcentration factors of chemicals in barley after application into the soil and physico-chemical and structural mass parameters are investigated and indicated in the form of tables and diagrams. (HK) [de

Using Chemicals to Optimize Conformance Control in Fractured Reservoirs; TOPICAL

International Nuclear Information System (INIS)

Seright, Randall S.; Liang, Jenn-Tai; Schrader, Richard; Hagstrom II, John; Wang, Ying; Kumar, Ananad; Wavrik, Kathryn

2001-01-01

This report describes work performed during the third and final year of the project, Using Chemicals to Optimize Conformance Control in Fractured Reservoirs. This research project had three objectives. The first objective was to develop a capability to predict and optimize the ability of gels to reduce permeability to water more than that to oil or gas. The second objective was to develop procedures for optimizing blocking agent placement in wells where hydraulic fractures cause channeling problems. The third objective was to develop procedures to optimize blocking agent placement in naturally fractured reservoirs

Why the toxic substances control act needs an overhaul, and how to strengthen oversight of chemicals in the interim.

Science.gov (United States)

Vogel, Sarah A; Roberts, Jody A

2011-05-01

The Toxic Substances Control Act gives the Environmental Protection Agency (EPA) the authority to regulate industrial chemicals not covered by other statutes. Today there are more than 83,000 such chemicals. However, the law is widely perceived as weak and outdated, and various stakeholders have called for its reform, citing the EPA's inability to regulate the use of asbestos, among other substances. We analyze the flaws in the act and suggest ways in which the EPA might better position itself to manage chemical risks and protect the public's health. In addition to the new tools and technologies it is adopting, the agency needs new allies-both inside and outside the government-in its efforts to identify and control hazardous chemicals.

Environmental and hormonal factors controlling reversible colour change in crab spiders.

Science.gov (United States)

Llandres, Ana L; Figon, Florent; Christidès, Jean-Philippe; Mandon, Nicole; Casas, Jérôme

2013-10-15

Habitat heterogeneity that occurs within an individual's lifetime may favour the evolution of reversible plasticity. Colour reversibility has many different functions in animals, such as thermoregulation, crypsis through background matching and social interactions. However, the mechanisms underlying reversible colour changes are yet to be thoroughly investigated. This study aims to determine the environmental and hormonal factors underlying morphological colour changes in Thomisus onustus crab spiders and the biochemical metabolites produced during these changes. We quantified the dynamics of colour changes over time: spiders were kept in yellow and white containers under natural light conditions and their colour was measured over 15 days using a spectrophotometer. We also characterised the chemical metabolites of spiders changing to a yellow colour using HPLC. Hormonal control of colour change was investigated by injecting 20-hydroxyecdysone (20E) into spiders. We found that background colouration was a major environmental factor responsible for colour change in crab spiders: individuals presented with white and yellow backgrounds changed to white and yellow colours, respectively. An ommochrome precursor, 3-OH-kynurenine, was the main pigment responsible for yellow colour. Spiders injected with 20E displayed a similar rate of change towards yellow colouration as spiders kept in yellow containers and exposed to natural sunlight. This study demonstrates novel hormonal manipulations that are capable of inducing reversible colour change.

Factores de riesgo para carcinoma basocelular: Estudio de casos-controles en Córdoba Risk factors for basal cell carcinoma: Case-control study in Cordoba

Directory of Open Access Journals (Sweden)

Alejandro Ruiz Lascano

2005-12-01

Full Text Available El carcinoma basocelular es una enfermedad compleja. Su etiología es todavía poco clara y a pesar de su frecuencia hay pocos datos sobre factores de riesgo. Nosotros evaluamos factores de riesgo potenciales para carcinoma basocelular en una población de Córdoba (Argentina. Este estudio de casos y controles incluyó a 88 casos nuevos de carcinoma basocelular, y 88 controles pareados por sexo y edad. Los siguientes factores de riesgo fueron significativos en el análisis multivariado: fototipos I, II y III, exposición solar recreativa alta después de los 20 años de edad, exposición solar alta en vacaciones en la playa y la presencia de queratosis actínicas.Basal cell carcinoma is undoubtedly a complex disease. Its etiology is still unclear and despite its frequency, there is a paucity of data on its risk factors. We assessed potential risk factors for basal cell carcinoma in a population from Córdoba (Argentina. This case-control study involved 88 newly diagnosed cases and 88 controls, matched by age and sex. The following risk factors were significant in the multivariate analysis: skin type I-II-III, high recreational sun exposure after 20 years of age, high sun exposure for beach holidays and actinic keratosis.

Factors controlling accumulation of soil organic carbon along vegetation succession in a typical karst region in Southwest China

Energy Technology Data Exchange (ETDEWEB)

Liu, Shujuan [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Zhang, Wei [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Wang, Kelin, E-mail: kelin@isa.ac.cn [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); Pan, Fujing [Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha 410125 (China); Huanjiang Observation and Research Station of Karst Ecosystem, Chinese Academy of Sciences, Huanjiang, Guangxi Zhuang Autonomous Region 547100 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yang, Shan [Changsha university, Changsha 410003 (China); Shu, Shiyan [Changjiang Project Supervision & Consultancy Co. Ltd, Wuhan 430010 (China); Changjiang Ecology (Hubei) Technology Development LLC, Wuhan 430010 (China)

2015-07-15

Vegetation succession enhances the accumulation of carbon in the soil. However, little is known about the mechanisms underlying soil organic carbon (SOC) accumulation in different vegetation types in the karst region of Southwest China. The goal of this study was to identify and prioritize the effects of environmental parameters, including soil physico-chemical properties, microbial biomass, enzyme activities, and litter characteristics, on SOC accumulation along a vegetation succession sere (grassland, shrubland, secondary forest, and primary forest) in the karst landscape of Southwest China. Relationships between these parameters and SOC were evaluated by redundancy analysis. The results showed that SOC accumulation was significantly different among vegetation types (P < 0.01) and increased with vegetation succession (from 29.10 g·kg{sup −1} in grassland to 73.92 g·kg{sup −1} in primary forest). Soil biochemistry and physical characteristics significantly affected the accumulation of SOC. Soil microbial biomass showed a predominant effect on SOC in each of the four vegetation types. In addition, the soil physical property (especially the silt content) was another controlling factor in the early stages (grassland), and urease activity and saccharase activity were important controlling factors in the early-middle and middle-late stages, respectively. Litter characteristics only showed mild effects on SOC accumulation. Variation partitioning analysis showed that the contribution of sole main factors to SOC variation decreased, while the interaction effect among parameters increased along the succession gradient. - Highlights: • Vegetation restoration is conducive to soil carbon sequestration in karst areas. • The factors controlling SOC accumulation differed along vegetation succession. • The interaction effect among significant factors became more and more prominent along succession.

Geochemical factors in borehole-shaft plug longevity

International Nuclear Information System (INIS)

Roy, D.M.

1981-01-01

Geochemical investigations that address factors controlling the longevity of repository sealing materials in a geochemical environment are discussed. Studies are being made of cement-based materials as major candidates for seals for borehole plugging, and shaft and tunnel sealing in certain potential repository environments. Factors controlling the extent of attainment of equilibrium of the plug components with time and the rate of approach to a state of stable equilibrium of the plug component chemical subsystem within the total system are discussed. The effect of these factors on changes in physical, mechanical and thermal properties of a seal system, and the consequent effectiveness of the seal in preventing transport of radioactive waste species are the dominant features to be determined. Laboratory experiments on the effects of anticipated temperature, pressure, and environmental factors (including chemical composition and specific rock type) are described. Thermodynamic studies are used to determine the potentially stable reaction products under conditions similar to those anticipated for the repository boreholes, shafts, and tunnels during and after the operating stage. Multitemperature reaction series are studied, and reaction kinetics are investigated for the purpose of predicting the course of likely reactions. Detailed studies of permeability, diffusion, and interfacial properties and chemical and microphase characterization of the products of experiments are carried out. Characterization studies of old and ancient cements, mortars, and concretes and prototype man-made seal materials are performed to further assess the factors associated with longevity

Controlled assembly of organic whispering-gallery-mode microlasers as highly sensitive chemical vapor sensors.

Science.gov (United States)

Gao, Miaomiao; Wei, Cong; Lin, Xianqing; Liu, Yuan; Hu, Fengqin; Zhao, Yong Sheng

2017-03-09

We demonstrate the fabrication of organic high Q active whispering-gallery-mode (WGM) resonators from π-conjugated polymer by a controlled emulsion-solvent-evaporation method, which can simultaneously provide optical gain and act as an effective resonant cavity. By measuring the shift of their lasing modes on exposure to organic vapor, we successfully monitored the slight concentration variation in the chemical gas. These microlaser sensors demonstrated high detection sensitivity and good signal repeatability under continuous chemical gas treatments. The results offer an effective strategy to design miniaturized optical sensors.

Coupled sensor/platform control design for low-level chemical detection with position-adaptive micro-UAVs

Science.gov (United States)

Goodwin, Thomas; Carr, Ryan; Mitra, Atindra K.; Selmic, Rastko R.

2009-05-01

We discuss the development of Position-Adaptive Sensors [1] for purposes for detecting embedded chemical substances in challenging environments. This concept is a generalization of patented Position-Adaptive Radar Concepts developed at AFRL for challenging conditions such as urban environments. For purposes of investigating the detection of chemical substances using multiple MAV (Micro-UAV) platforms, we have designed and implemented an experimental testbed with sample structures such as wooden carts that contain controlled leakage points. Under this general concept, some of the members of a MAV swarm can serve as external position-adaptive "transmitters" by blowing air over the cart and some of the members of a MAV swarm can serve as external position-adaptive "receivers" that are equipped with chemical or biological (chem/bio) sensors that function as "electronic noses". The objective can be defined as improving the particle count of chem/bio concentrations that impinge on a MAV-based position-adaptive sensor that surrounds a chemical repository, such as a cart, via the development of intelligent position-adaptive control algorithms. The overall effect is to improve the detection and false-alarm statistics of the overall system. Within the major sections of this paper, we discuss a number of different aspects of developing our initial MAV-Based Sensor Testbed. This testbed includes blowers to simulate position-adaptive excitations and a MAV from Draganfly Innovations Inc. with stable design modifications to accommodate our chem/bio sensor boom design. We include details with respect to several critical phases of the development effort including development of the wireless sensor network and experimental apparatus, development of the stable sensor boom for the MAV, integration of chem/bio sensors and sensor node onto the MAV and boom, development of position-adaptive control algorithms and initial tests at IDCAST (Institute for the Development and

Status of dental health in chemical warfare victims: the case of Isfahan, Iran.

Science.gov (United States)

Mottaghi, Ahmad; Hoseinzade, Abolfath; Zamani, Elham; Araghizade, Habib Allah

2012-01-01

Little evidence is available regarding the dental health of victims of chemical warfare in Iran. Therefore, in this study, we examined the decayed, missing, and filled teeth index (DMFT), community periodontal index of treatment needs (CPITN), and saliva secretion rate of chemical warfare victims living in the province of Isfahan in Iran. This case-control study was conducted with 300 chemical warfare victims as the treatment group and 300 age-matched individuals without exposure to chemical warfare as the control group. DMFT and CPITN indices and saliva secretion rate were measured and compared between the two groups. Chemical warfare victims had significantly higher scores than the control group for decayed teeth (4.25 ± 3.88 vs 3.52 ± 2.81; P=0.009), missing teeth (8.79 ± 9.3 vs 6.15 ± 8.43; Pwarfare victims was significantly lower than that in the control group (1.71 ± 0.05 vs 3.85 ± 1.95 cc/5 min; PChemical warfare victims have relatively poor dental/oral health. Chemical injury might cause a dysfunction in saliva secretion, with decrease in saliva secretion increasing the risk for tooth decay and periodontal disorders. Further research is required to find out the exact underlying mechanisms and the factors associated with poor dental/oral health in chemical warfare victims.

Controlling the resistivity gradient in chemical vapor deposition-deposited aluminum-doped zinc oxide

NARCIS (Netherlands)

Ponomarev, M. V.; Verheijen, M. A.; Keuning, W.; M. C. M. van de Sanden,; Creatore, M.

2012-01-01

Aluminum-doped ZnO (ZnO:Al) grown by chemical vapor deposition (CVD) generally exhibit a major drawback, i.e., a gradient in resistivity extending over a large range of film thickness. The present contribution addresses the plasma-enhanced CVD deposition of ZnO: Al layers by focusing on the control

Synthetic biology expands chemical control of microorganisms.

Science.gov (United States)

Ford, Tyler J; Silver, Pamela A

2015-10-01

The tools of synthetic biology allow researchers to change the ways engineered organisms respond to chemical stimuli. Decades of basic biology research and new efforts in computational protein and RNA design have led to the development of small molecule sensors that can be used to alter organism function. These new functions leap beyond the natural propensities of the engineered organisms. They can range from simple fluorescence or growth reporting to pathogen killing, and can involve metabolic coordination among multiple cells or organisms. Herein, we discuss how synthetic biology alters microorganisms' responses to chemical stimuli resulting in the development of microbes as toxicity sensors, disease treatments, and chemical factories. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficiency factor of a chemical nuclear reactor with gamma sources

International Nuclear Information System (INIS)

Anguis T, C.

1975-01-01

A chemonuclear reactor is simulated in order to calculate the efficiency factor of molecular species in chemical reactions induced by gamma radiation, with the purpose to obtain information for its design and consider the electromagnetic energy as a possible solution to the present problem of energy. The research is based on a mathematical model of succesive Compton processes applied to spherical and cylindrical geometry and corroborated through the absorbed dose and the experimental date of the increase factor, for the radioisotopic sources Co-60 and Cs-137 relating the quantity of energy deposited into various cylinders with the G value, the relation radius/height of the reactor is optimized according to the molecular production. This is illustrated with the radiolysis of a solution of CH 3 OH/H 2 O which forms H 2 and with the obtainment of C 2 H 5 Br that represents and industrial process induced radioactively. The results show a greater energy deposition with Cs-137 but a larger production of H 2 /hr with Co-60, and besides we can find high production values of C 2 H 5 Br. The cylinder with more advantages is that whose relation R/H is of 0.5. It can be concluded that the final selection of the reactor should be made after a more intense study of the used isotope and the source activity. The efficiency factor of H 2 can be increased selecting the appropriate type and concentration of solute of the irradiated aqueous solutions

Serum levels of chemical elements in esophageal squamous cell carcinoma in Anyang, China: a case-control study based on machine learning methods.

Science.gov (United States)

Lin, Tong; Liu, Tiebing; Lin, Yucheng; Zhang, Chaoting; Yan, Lailai; Chen, Zhongxue; He, Zhonghu; Wang, Jingyu

2017-09-24

Esophageal squamous cell carcinoma (ESCC) is the predominant form of esophageal carcinoma with extremely aggressive nature and low survival rate. The risk factors for ESCC in the high-incidence areas of China remain unclear. We used machine learning methods to investigate whether there was an association between the alterations of serum levels of certain chemical elements and ESCC. Primary healthcare unit in Anyang city, Henan Province of China. 100 patients with ESCC and 100 healthy controls matched for age, sex and region were included. Primary outcome was the classification accuracy. Secondary outcome was the p Value of the t-test or rank-sum test. Both traditional statistical methods of t-test and rank-sum test and fashionable machine learning approaches were employed. Random Forest achieves the best accuracy of 98.38% on the original feature vectors (without dimensionality reduction), and support vector machine outperforms other classifiers by yielding accuracy of 96.56% on embedding spaces (with dimensionality reduction). All six classifiers can achieve accuracies more than 90% based on the single most important element Sr. The other two elements with distinctive difference are S and P, providing accuracies around 80%. More than half of chemical elements were found to be significantly different between patients with ESCC and the controls. These results suggest clear differences between patients with ESCC and controls, implying some potential promising applications in diagnosis, prognosis, pharmacy and nutrition of ESCC. However, the results should be interpreted with caution due to the retrospective design nature, limited sample size and the lack of several potential confounding factors (including obesity, nutritional status, and fruit and vegetable consumption and potential regional carcinogen contacts). © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted

Risk factors for cataract: A case control study

Directory of Open Access Journals (Sweden)

Ughade Suresh

1998-01-01

Full Text Available The present study was designed as a hospital-based, group-matched, case-control investigation into the risk factors associated with age-related cataract in central India. The study included 262 cases of age-related cataract and an equal number of controls. A total of 21 risk factors were evaluated: namely, low socioeconomic status (SES, illiteracy, marital status, history of diarrhoea, history of diabetes, glaucoma, use of cholinesterase inhibitors, steroids, spironolactone, nifedipine, analgesics, myopia early in life, renal failure, heavy smoking, heavy alcohol consumption, hypertension, low body mass index (BMI, use of cheaper cooking fuel, working in direct sunlight, family history of cataract, and occupational exposure. In univariate analysis, except marital status, low BMI, renal failure, use of steroids, spironolactone, analgesics, and occupational exposure, all 14 other risk factors were found significantly associated with age-related cataract. Unconditional multiple logistic regression analysis confirmed the significance of low SES, illiteracy, history of diarrhoea, diabetes, glaucoma, myopia, smoking, hypertension and cheap cooking fuel. The etiological role of these risk factors in the outcome of cataract is confirmed by the estimates of attributable risk proportion. The estimates of population attributable risk proportion for these factors highlight the impact of elimination of these risk factors on the reduction of cataract in this population.

Revisiting factors controlling methane emissions from high-Arctic tundra

DEFF Research Database (Denmark)

Mastepanov, M.; Sigsgaard, C.; Tagesson, T.

2013-01-01

controlling methane emission, i.e. temperature and water table position. Late in the growing season CH4 emissions were found to be very similar between the study years (except the extremely dry 2010) despite large differences in climatic factors (temperature and water table). Late-season bursts of CH4...... short-term control factors (temperature and water table). Our findings suggest the importance of multiyear studies with a continued focus on shoulder seasons in Arctic ecosystems....

Power factor improvement in three-phase networks with unbalanced inductive loads using the Roederstein ESTAmat RPR power factor controller

Science.gov (United States)

Diniş, C. M.; Cunţan, C. D.; Rob, R. O. S.; Popa, G. N.

2018-01-01

The paper presents the analysis of a power factor with capacitors banks, without series coils, used for improving power factor for a three-phase and single-phase inductive loads. In the experimental measurements, to improve the power factor, the Roederstein ESTAmat RPR power factor controller can command up to twelve capacitors banks, while experimenting using only six capacitors banks. Six delta capacitors banks with approximately equal reactive powers were used for experimentation. The experimental measurements were carried out with a three-phase power quality analyser which worked in three cases: a case without a controller with all capacitors banks permanently parallel connected with network, and two other cases with power factor controller (one with setting power factor at 0.92 and the other one at 1). When performing experiments with the power factor controller, a current transformer was used to measure the current on one phase (at a more charged or less loaded phase).

Evaluation of factors affecting adherence to asthma controller ...

African Journals Online (AJOL)

Evaluation of factors affecting adherence to asthma controller therapy in chest clinics in a sub-Saharan African setting: a cross-sectional study. ... Background: Adherence to controller therapy in asthma is a major concern during the management of the disease. Objective: To determine the adherence rate and identify the ...

Experience with multiple control groups in a large population-based case-control study on genetic and environmental risk factors.

Science.gov (United States)

Pomp, E R; Van Stralen, K J; Le Cessie, S; Vandenbroucke, J P; Rosendaal, F R; Doggen, C J M

2010-07-01

We discuss the analytic and practical considerations in a large case-control study that had two control groups; the first control group consisting of partners of patients and the second obtained by random digit dialling (RDD). As an example of the evaluation of a general lifestyle factor, we present body mass index (BMI). Both control groups had lower BMIs than the patients. The distribution in the partner controls was closer to that of the patients, likely due to similar lifestyles. A statistical approach was used to pool the results of both analyses, wherein partners were analyzed with a matched analysis, while RDDs were analyzed without matching. Even with a matched analysis, the odds ratio with partner controls remained closer to unity than with RDD controls, which is probably due to unmeasured confounders in the comparison with the random controls as well as intermediary factors. However, when studying injuries as a risk factor, the odds ratio remained higher with partner control subjects than with RRD control subjects, even after taking the matching into account. Finally we used factor V Leiden as an example of a genetic risk factor. The frequencies of factor V Leiden were identical in both control groups, indicating that for the analyses of this genetic risk factor the two control groups could be combined in a single unmatched analysis. In conclusion, the effect measures with the two control groups were in the same direction, and of the same order of magnitude. Moreover, it was not always the same control group that produced the higher or lower estimates, and a matched analysis did not remedy the differences. Our experience with the intricacies of dealing with two control groups may be useful to others when thinking about an optimal research design or the best statistical approach.

A survey of process control computers at the Idaho Chemical Processing Plant

International Nuclear Information System (INIS)

Dahl, C.A.

1989-01-01

The Idaho Chemical Processing Plant (ICPP) at the Idaho National Engineering Laboratory is charged with the safe processing of spent nuclear fuel elements for the United States Department of Energy. The ICPP was originally constructed in the late 1950s and used state-of-the-art technology for process control at that time. The state of process control instrumentation at the ICPP has steadily improved to keep pace with emerging technology. Today, the ICPP is a college of emerging computer technology in process control with some systems as simple as standalone measurement computers while others are state-of-the-art distributed control systems controlling the operations in an entire facility within the plant. The ICPP has made maximal use of process computer technology aimed at increasing surety, safety, and efficiency of the process operations. Many benefits have been derived from the use of the computers for minimal costs, including decreased misoperations in the facility, and more benefits are expected in the future

The effects of chemical and physical factors on mammalian embryo culture and their importance for the practice of assisted human reproduction.

Science.gov (United States)

Wale, Petra L; Gardner, David K

2016-01-01

Although laboratory procedures, along with culture media formulations, have improved over the past two decades, the issue remains that human IVF is performed in vitro (literally 'in glass'). Using PubMed, electronic searches were performed using keywords from a list of chemical and physical factors with no limits placed on time. Examples of keywords include oxygen, ammonium, volatile organics, temperature, pH, oil overlays and incubation volume/embryo density. Available clinical and scientific evidence surrounding physical and chemical factors have been assessed and presented here. Development of the embryo outside the body means that it is constantly exposed to stresses that it would not experience in vivo. Sources of stress on the human embryo include identified factors such as pH and temperature shifts, exposure to atmospheric (20%) oxygen and the build-up of toxins in the media due to the static nature of culture. However, there are other sources of stress not typically considered, such as the act of pipetting itself, or the release of organic compounds from the very tissue culture ware upon which the embryo develops. Further, when more than one stress is present in the laboratory, there is evidence that negative synergies can result, culminating in significant trauma to the developing embryo. It is evident that embryos are sensitive to both chemical and physical signals within their microenvironment, and that these factors play a significant role in influencing development and events post transfer. From the viewpoint of assisted human reproduction, a major concern with chemical and physical factors lies in their adverse effects on the viability of embryos, and their long-term effects on the fetus, even as a result of a relatively brief exposure. This review presents data on the adverse effects of chemical and physical factors on mammalian embryos and the importance of identifying, and thereby minimizing, them in the practice of human IVF. Hence, optimizing the

Controllable chemical vapor deposition of large area uniform nanocrystalline graphene directly on silicon dioxide

DEFF Research Database (Denmark)

Sun, Jie; Lindvall, Niclas; Cole, Matthew T.

2012-01-01

Metal-catalyst-free chemical vapor deposition (CVD) of large area uniform nanocrystalline graphene on oxidized silicon substrates is demonstrated. The material grows slowly, allowing for thickness control down to monolayer graphene. The as-grown thin films are continuous with no observable pinholes...

Control of Chemical Equilibrium by Solvent: A Basis for Teaching Physical Chemistry of Solutions

Science.gov (United States)

Prezhdo, Oleg V.; Craig, Colleen F.; Fialkov, Yuriy; Prezhdo, Victor V.

2007-01-01

The study demonstrates that the solvent present in a system can highly alter and control the chemical equilibrium of a system. The results show that the dipole moment and polarizibility of a system can be highly altered by using different mixed solvents.

Post-control surveillance of Triatoma infestans and Triatoma sordida with chemically-baited sticky traps.

Science.gov (United States)

Rojas de Arias, Antonieta; Abad-Franch, Fernando; Acosta, Nidia; López, Elsa; González, Nilsa; Zerba, Eduardo; Tarelli, Guillermo; Masuh, Héctor

2012-01-01

Chagas disease prevention critically depends on keeping houses free of triatomine vectors. Insecticide spraying is very effective, but re-infestation of treated dwellings is commonplace. Early detection-elimination of re-infestation foci is key to long-term control; however, all available vector-detection methods have low sensitivity. Chemically-baited traps are widely used in vector and pest control-surveillance systems; here, we test this approach for Triatoma spp. detection under field conditions in the Gran Chaco. Using a repeated-sampling approach and logistic models that explicitly take detection failures into account, we simultaneously estimate vector occurrence and detection probabilities. We then model detection probabilities (conditioned on vector occurrence) as a function of trapping system to measure the effect of chemical baits. We find a positive effect of baits after three (odds ratio [OR] 5.10; 95% confidence interval [CI(95)] 2.59-10.04) and six months (OR 2.20, CI(95) 1.04-4.65). Detection probabilities are estimated at p ≈ 0.40-0.50 for baited and at just p ≈ 0.15 for control traps. Bait effect is very strong on T. infestans (three-month assessment: OR 12.30, CI(95) 4.44-34.10; p ≈ 0.64), whereas T. sordida is captured with similar frequency in baited and unbaited traps. Chemically-baited traps hold promise for T. infestans surveillance; the sensitivity of the system at detecting small re-infestation foci rises from 12.5% to 63.6% when traps are baited with semiochemicals. Accounting for imperfect detection, infestation is estimated at 26% (CI(95) 16-40) after three and 20% (CI(95) 11-34) after six months. In the same assessments, traps detected infestation in 14% and 8.5% of dwellings, whereas timed manual searches (the standard approach) did so in just 1.4% of dwellings only in the first survey. Since infestation rates are the main indicator used for decision-making in control programs, the approach we present may help improve T

Effect of endogenous factors on the chemical perception of Grapholita molesta (Busck) (Lepidoptera: Tortricidae) to sex pheromone; Efeito de fatores endogenos na percepcao quimica de Grapholita molesta(Busck) (Lepidoptera: Tortricidae) ao feromonio sexual

Energy Technology Data Exchange (ETDEWEB)

Altafini, Deisi L.; Sant' Ana, Josue; Redaelli, Luiza R., E-mail: deisila@gmail.co [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Fitossanidade. Programa de Pos-Graduacao em Fitotecnia

2010-06-15

The oriental fruit moth, Grapholita molesta (Busck), stands out as one of the most important pest in Rosaceae orchards in Brazil. During feeding, caterpillars bore into shoots, branches and fruits, impairing the commercial production. This work aimed to study the effect of endogenous factors in the chemical perception and in the species chemotactic behavior, seeking to optimize monitoring and the behavioral control of this pest. We evaluated male electroantennographical (EAG) and chemotactical (olfactometry) responses to the synthetic sex pheromone in different ages, virgins or mated and fed or unfed. The EAG responses of males did not differ for all evaluated factors. Nevertheless, the chemotactical behavior of males seems to decrease with age, not varying as a function of mating or feeding conditions. The knowledge about the interference of these factors in G. molesta may help with the interpretation of fi eld results, allowing the development of suitable and reliable control measures based on infochemicals for behavioral control. (author)

Non- chemical methods of seed treatment for control of seed- borne pathogens on vegetables

NARCIS (Netherlands)

Amein, T.; Wright, S.A.I.; Wickstrom, M.; Schmitt, A.; Koch, E.; Wolf, van der J.M.; Groot, S.P.C.; Werner, S.; Jahn, M.

2006-01-01

The aim of EU-project "Seed Treatments for Organic Vegetable Production" (STOVE) was to evaluate non-chemical methods for control of seed-borne pathogens in organic vegetable production. Physical (hot air, hot water and electron) and biologi-cal (microorganisms and different agents of natural

Helium leak and chemical impurities control technology in HTTR

International Nuclear Information System (INIS)

Tochio, Daisuke; Shimizu, Atsushi; Hamamoto, Shimpei; Sakaba, Nariaki

2014-01-01

Japan Atomic Energy Agency (JAEA) has designed and developed high-temperature gas-cooled reactor (HTGR) hydrogen cogeneration system named gas turbine high-temperature reactor (GTHTR300C) as a commercial HTGR. Helium gas is used as the primary coolant in HTGR. Helium gas is easy to leak, and the primary helium leakage should be controlled tightly from the viewpoint of preventing the release of radioactive materials to the environment. Moreover from the viewpoint of preventing the oxidization of graphite and metallic material, the helium coolant chemistry should be controlled tightly. The primary helium leakage and the helium coolant chemistry during the operation is the major factor in the HTGR for commercialization of HTGR system. This paper shows the design concept and the obtained operational experience on the primary helium leakage control and primary helium impurity control in the high-temperature engineering test reactor (HTTR) of JAEA. Moreover, the future plan to obtain operational experience of these controls for commercialization of HTGR system is shown. (author)

Multiple chemical sensitivity

DEFF Research Database (Denmark)

Tran, Marie Thi Dao; Arendt-Nielsen, Lars; Kupers, Ron

2013-01-01

BACKGROUND: Multiple Chemical Sensitivity (MCS) is a chronic condition characterized by recurrent, non-specific symptoms in response to chemically unrelated exposures in non-toxic concentrations. Although the pathophysiology of MCS remains unknown, central sensitization may be an important factor...

Comparison of atherogenic risk factors among poorly controlled and well-controlled adolescent phenylketonuria patients.

Science.gov (United States)

Gündüz, Mehmet; Çakar, Sevim; Kuyum, Pınar; Makay, Balahan; Arslan, Nur

2016-06-01

Previous studies investigating the known risk factors of atherosclerosis in phenylketonuria patients have shown conflicting results. The primary aim of our study was to investigate the serum atherogenic markers in adolescent classical phenylketonuria patients and compare these parameters with healthy peers. The secondary aim was to compare these atherogenic markers in well-controlled and poorly controlled patients. A total of 59 patients (median age: 12.6 years, range: 11-17 years) and 44 healthy controls (median age: 12.0 years, range: 11-15 years) were enrolled in our study. Phenylketonuria patients were divided into two groups: well-controlled (serum phenylalanine levels below 360 µmol/L; 24 patients) and poorly controlled patients (serum phenylalanine levels higher than 360 µmol/L). The mean high-density lipoprotein cholesterol levels of well-controlled patients (1.0±0.2 mmol/L) were significantly lower compared with poorly controlled patients and controls (1.1±0.2 mmol/L, p=0.011 and 1.4±0.2 mmol/L, pphenylketonuria patients. In particular, these changes were more prominent in well-controlled patients. We conclude that phenylketonuria patients might be at risk for atherosclerosis, and therefore screening for atherosclerotic risk factors should be included in the phenylketonuria therapy and follow-up in addition to other parameters.

Chemical control of different Digitaria insularis populations and management of a glyphosate-resistant population

OpenAIRE

CORREIA,N.M.; ACRA,L.T.; BALIEIRO,G.

2015-01-01

This study aimed to control different populations of Digitaria insularisby glyphosate herbicide, isolated and mixed, besides the combination of methods (chemical and mechanical) to manage resistant adult plants. Three experiments were conducted, one in pots which were maintained under non-controlled conditions and two under field conditions. In the experiment in pots, twelve populations of D. insularis were sprayed with isolated glyphosate (1.44 and 2.16 kg a.e. ha-1) and mixed (1.44 and 2.16...

Public perception and attitude towards chemical industry park in Dalian, Bohai Rim.

Science.gov (United States)

He, Guizhen; Chen, Chunci; Zhang, Lei; Lu, Yonglong

2018-04-01

Recent decade has witnessed accelerating expansion of chemical industry and increasing conflicts between the local citizens, governmental authorities and project developers, especially in some coastal and port cities in China. Development and transformation of chemical industrial parks has been adopted as a national initiative recently. However, there is a paucity of research examining public perspectives on chemical industrial parks and their risks. Aiming to understand public perception, attitude, and response and the factors underlying the support/acceptance of chemical industry park, this paper investigated 418 residents neighboring to two chemical industrial parks, Dalian in Bohai Rim through face-to-face questionnaire survey. The results showed the knowledge of the respondents on the chemical industrial parks development was very limited. The respondents had complex perceptions on the environmental impacts, risks control, social-economic benefits, and problem awareness. The current levels of information disclosure and public participation were very low. The central governmental official (44.3%) was the most trustworthy group by the respondents. Only 5.5% and 23.2% of the respondents supported the construction of a new CIP nearby and far away their homes, whilst 13% thought new CIP project as acceptable. The spearman correlation analysis results showed a strong NIMBY effect (Not In My Backyard). Factor analysis results demonstrated five latent factors: knowledge, benefit, information, trust, and participation. Multiple linear regression analysis indicated how socio-demographic differences and five latent factors might impact on the support/acceptance of the chemical industrial parks. Education level, trust, information, and participation were significant predictors of public support/acceptance level. This study contributes to our limited knowledge and understanding of public sentiments to the chemical industry parks in China. Copyright © 2017 Elsevier Ltd

Simplifying the audit of risk factor recording and control

DEFF Research Database (Denmark)

Zhao, Min; Cooney, Marie Therese; Klipstein-Grobusch, Kerstin

2016-01-01

BACKGROUND: To simplify the assessment of the recording and control of coronary heart disease risk factors in different countries and regions. DESIGN: The SUrvey of Risk Factors (SURF) is an international clinical audit. METHODS: Data on consecutive patients with established coronary heart disease...

Spatial patterns and controls of soil chemical weathering rates along a transient hillslope

Science.gov (United States)

Yoo, K.; Mudd, S.M.; Sanderman, J.; Amundson, Ronald; Blum, A.

2009-01-01

Hillslopes have been intensively studied by both geomorphologists and soil scientists. Whereas geomorphologists have focused on the physical soil production and transport on hillslopes, soil scientists have been concerned with the topographic variation of soil geochemical properties. We combined these differing approaches and quantified soil chemical weathering rates along a grass covered hillslope in Coastal California. The hillslope is comprised of both erosional and depositional sections. In the upper eroding section, soil production is balanced by physical erosion and chemical weathering. The hillslope then transitions to a depositional slope where soil accumulates due to a historical reduction of channel incision at the hillslope's base. Measurements of hillslope morphology and soil thickness were combined with the elemental composition of the soil and saprolite, and interpreted through a process-based model that accounts for both chemical weathering and sediment transport. Chemical weathering of the minerals as they moved downslope via sediment transport imparted spatial variation in the geochemical properties of the soil. Inverse modeling of the field and laboratory data revealed that the long-term soil chemical weathering rates peak at 5 g m- 2 yr- 1 at the downslope end of the eroding section and decrease to 1.5 g m- 2 yr- 1 within the depositional section. In the eroding section, soil chemical weathering rates appear to be primarily controlled by the rate of mineral supply via colluvial input from upslope. In the depositional slope, geochemical equilibrium between soil water and minerals appeared to limit the chemical weathering rate. Soil chemical weathering was responsible for removing 6% of the soil production in the eroding section and 5% of colluvial influx in the depositional slope. These were among the lowest weathering rates reported for actively eroding watersheds, which was attributed to the parent material with low amount of weatherable

Scales of columnar jointing in igneous rocks: field measurements and controlling factors

Science.gov (United States)

Hetényi, György; Taisne, Benoît; Garel, Fanny; Médard, Étienne; Bosshard, Sonja; Mattsson, Hannes B.

2012-03-01

Columnar jointing is a common feature of solidified lavas, sills and dikes, but the factors controlling the characteristic stoutness of columns remain debated, and quantitative field observations are few in number. In this paper, we provide quantitative measurements on sizing of columnar joint sets and our assessment of the principal factors controlling it. We focus on (1) chemistry, as it is the major determinant of the physical (mechanical and thermal) properties of the lava, and (2) geology, as it influences the style of emplacement and lava geometry, setting boundary conditions for the cooling process and the rate of heat loss. In our analysis, we cover lavas with a broad range of chemical compositions (from basanite to phonolite, for six of which we provide new geochemical analyses) and of geological settings. Our field measurements cover 50 columnar jointing sites in three countries. We provide reliable, manually digitized data on the size of individual columns and focus the mathematical analysis on their geometry (23,889 data on side length, of which 17,312 are from full column sections and 3,033 data on cross-sectional area and order of polygonality). The geometrical observations show that the variation in characteristic size of columns between different sites exceeds one order of magnitude (side length ranging from 8 to 338 cm) and that the column-bounding polygons' average order is less than 6. The network of fractures is found to be longer than required by a minimum-energy hexagonal configuration, indicating a non-equilibrium, geologically quick process. In terms of the development and characteristic sizing of columnar joint sets, our observations suggest that columns are the result of an interplay between the geological setting of emplacement and magma chemistry. When the geological setting constrains the geometry of the emplaced body, it exerts a stronger control on characteristic column stoutness. At unconstrained geometries (e.g. unconfined lava

Evaluation of chemical, botanical and cultural managements of termites control.

Science.gov (United States)

Dufera, Jiregna Tasisa; Fufa, Tena Gobena

2014-01-15

The study was conducted at Bojdi Dirmaji District, Wollega Zone (Western Ethiopia) using Randomized Complete Block Design with three replications. Eight different treatments of chemical, botanical and cultural control methods independently and in combinations were evaluated to identify the most effective method which is environmentally sustainable and economically feasible in controlling the termite problems. The data were collected over 12 weeks and analysis of variance showed significant difference among the treatments for all parameters. Maesa lanceolata 100 g alone showed lower percent damage between 2-8 weeks (33.3%), later on after 9-12 weeks it become non significant and the destructed mound was recovered. Mound treated with Diazinon 60% EC at the rate of 25 and 20 mL alone and Diazinon 60% EC combination with queen removal at rate of 15 and 10 mL showed significant control overall the treatment. From the results of the study the lower rate of Diazinon 60% EC (10 mL per mound) and queen removal could be better option to manage the termite problem and could be more sustainable and integrated manner in the study area.

Beverton-Holt discrete pest management models with pulsed chemical control and evolution of pesticide resistance

Science.gov (United States)

Liang, Juhua; Tang, Sanyi; Cheke, Robert A.

2016-07-01

Pest resistance to pesticides is usually managed by switching between different types of pesticides. The optimal switching time, which depends on the dynamics of the pest population and on the evolution of the pesticide resistance, is critical. Here we address how the dynamic complexity of the pest population, the development of resistance and the spraying frequency of pulsed chemical control affect optimal switching strategies given different control aims. To do this, we developed novel discrete pest population growth models with both impulsive chemical control and the evolution of pesticide resistance. Strong and weak threshold conditions which guarantee the extinction of the pest population, based on the threshold values of the analytical formula for the optimal switching time, were derived. Further, we addressed switching strategies in the light of chosen economic injury levels. Moreover, the effects of the complex dynamical behaviour of the pest population on the pesticide switching times were also studied. The pesticide application period, the evolution of pesticide resistance and the dynamic complexity of the pest population may result in complex outbreak patterns, with consequent effects on the pesticide switching strategies.

Combined Noncyclic Scheduling and Advanced Control for Continuous Chemical Processes

Directory of Open Access Journals (Sweden)

Damon Petersen

2017-12-01

Full Text Available A novel formulation for combined scheduling and control of multi-product, continuous chemical processes is introduced in which nonlinear model predictive control (NMPC and noncyclic continuous-time scheduling are efficiently combined. A decomposition into nonlinear programming (NLP dynamic optimization problems and mixed-integer linear programming (MILP problems, without iterative alternation, allows for computationally light solution. An iterative method is introduced to determine the number of production slots for a noncyclic schedule during a prediction horizon. A filter method is introduced to reduce the number of MILP problems required. The formulation’s closed-loop performance with both process disturbances and updated market conditions is demonstrated through multiple scenarios on a benchmark continuously stirred tank reactor (CSTR application with fluctuations in market demand and price for multiple products. Economic performance surpasses cyclic scheduling in all scenarios presented. Computational performance is sufficiently light to enable online operation in a dual-loop feedback structure.

Chemical composition of water from roofs in Gdansk, Poland

International Nuclear Information System (INIS)

Tsakovski, Stefan; Tobiszewski, Marek; Simeonov, Vasil; Polkowska, Zaneta; Namiesnik, Jacek

2010-01-01

This study deals with the assessment of roof runoff waters from the region of Gdansk collected during the winter season (2007/2008). The chemical analysis includes 16 chemical variables: major ions, PAHs and PCBs measured at 3 sampling sites for 6-14 rain events. Although the data set is of limited volume the statistical data treatment using self-organizing maps (SOM) reveals the main factors controlling roof runoff water quality even for a data set with small dimension. This effort for explanation of the identified factors by the possible emission sources of the urban environment and air-particulate formation seems to be very reliable. Additionally to the roof runoff water quality factors the rain events patterns are found: 'background' group of events and groups formally named 'PAHs', 'PCBs' and 'air-borne particles' - dominated events. The SOM classification results give an opportunity to uncover the role of roof 'impact' on the runoff waters. Rain runoff water quality is described by four latent factors and the 'roof' impact is uncovered. - Identification of the urban roof runoff water quality factors and 'roof' impact by self-organizing map classification.

Efficacy and mechanisms of non-antibacterial, chemical plaque control by dentifrices - An in vitro study

NARCIS (Netherlands)

Busscher, Henk J.; White, Don J.; Atema-Smit, Jelly; van der Mei, Henny C.

Objectives: The provision of antiplaque benefits to dentifrices assists patients in improving hygiene and reducing susceptibility to gingivitis and caries. Chemical plaque control involves different mechanisms and is mostly associated with antibacterial effects, but also includes effects on pellicle

Reasons of chlorella strain's resistance to physical and chemical factors of environment

Energy Technology Data Exchange (ETDEWEB)

Apasheva, L M; Bujiashvilie, D M; Naydich, V I; Shevchenko, V A

1979-07-01

Under environmental pollution it is necessary to study the reasons of an organism's resistance as well as the specificity of it. Some chlorella strains were under the influence of uv- and x-irradiation, heat treatment, cadmium salts, insecticide, and detergent. It was shown that cells which were resistant to physical factors were resistant to chemical intoxication, as well. The positive correlation between resistance of strains and the described influences and the levels of endogenic thiols was found. The second reason for higher resistance is an increase of free radicals' concentration. It is linked with increasing P/sub 700/ quantity of electron-transport chains that make possible higher levels of photosynthetic reactions of resistant cells.

Evaluation on the Effect of Load Follow Controller's Weighting Factors

Energy Technology Data Exchange (ETDEWEB)

Yu, Keuk Jong; Lee, Jae Gon [KHNP CRI, Daejeon (Korea, Republic of)

2016-10-15

there are several important physical effects that limit the possibilities of power variations in NPPs. Some major effects are moderator and xenon effect. Moderator effect is relation with moderator density change and xenon effect is relation with the concentration change of Xe-135 which could affect axial power shape. These effects are more significant with large magnitudes of power variations and they are considered as major disturbances at the aspect of control method. Due to the above physical effects, it is necessary to carefully change nuclear power considering power distribution change in the core. So, when nuclear plants are required to operate on load variation mode, we could control not only reactor power but also power distribution. Generally, power distribution is controlled by reactor operators who have enough experience, whereas reactor power is automatically controlled by automatic controllers. So, it is necessary to design an automatic controller that controls both reactor power and power distribution for frequent load following operation. Korea Hydro and Nuclear Power Co., LTD (KHNP) has been developing automatic load follow controller as a part of Advanced Power Reactor Plus (APR+) development. The developing controller is composed of three algorithms which could control reactor power and axial power shape. This paper aimed to evaluate the effect of the controller’s weighting factors. So, in this paper, we identify the meaning of the weighting factors and the controlled output weighting factors are selected among them. In this study, the effect of output weighting factors is analyzed. According to the simulation results, it is recommended that the weighting factor of power be between 200 and 400 and that of ASI be between 200 and 600. In the near future, based on the study, optimization of power and ASI weighting factors will be performed at the same time.

Hazardous Chemicals

Centers for Disease Control (CDC) Podcasts

Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.

Effect of genes controlling radiation sensitivity on chemical mutagenesis in yeast

International Nuclear Information System (INIS)

Prakash, L.

1975-01-01

Ultraviolet radiation, x radiation, nitrogen mustard, methyl methanesulfonate, and dimethyl sulfate were found to revert all the tester strains with the same efficiency or without any dependence on simple types of base-pair changes, and it was concluded that these mutagens were nonspecific in the types of base-pair changes produced. The cycl-131 tester was used in studies designed to determine the genetic control of mutation induction using a variety of mutagens. The rad 6 and rad g genes greatly reduce the frequency of chemically induced reversion of cycl-131

Pulse-density modulation control of chemical oscillation far from equilibrium in a droplet open-reactor system

OpenAIRE

Sugiura, Haruka; Ito, Manami; Okuaki, Tomoya; Mori, Yoshihito; Kitahata, Hiroyuki; Takinoue, Masahiro

2016-01-01

The design, construction and control of artificial self-organized systems modelled on dynamical behaviours of living systems are important issues in biologically inspired engineering. Such systems are usually based on complex reaction dynamics far from equilibrium; therefore, the control of non-equilibrium conditions is required. Here we report a droplet open-reactor system, based on droplet fusion and fission, that achieves dynamical control over chemical fluxes into/out of the reactor for c...

Factors associated with suicide: Case-control study in South Tyrol.

Science.gov (United States)

Giupponi, Giancarlo; Innamorati, Marco; Baldessarini, Ross J; De Leo, Diego; de Giovannelli, Francesca; Pycha, Roger; Conca, Andreas; Girardi, Paolo; Pompili, Maurizio

2018-01-01

As suicide is related to many factors in addition to psychiatric illness, broad and comprehensive risk-assessment for risk of suicide is required. This study aimed to differentiate nondiagnostic risk factors among suicides versus comparable psychiatric patients without suicidal behavior. We carried out a pilot, case-control comparison of 131 cases of suicide in South Tyrol matched for age and sex with 131 psychiatric controls, using psychological autopsy methods to evaluate differences in clinically assessed demographic, social, and clinical factors, using bivariate conditional Odds Risk comparisons followed by conditional regression modeling controlled for ethnicity. Based on multivariable conditional regression modeling, suicides were significantly more likely to have experienced risk factors, ranking as: [a] family history of suicide or attempt≥[b] recent interpersonal stressors≥[c] childhood traumatic events≥[d] lack of recent clinician contacts≥[e] previous suicide attempt≥[f] non-Italian ethnicity, but did not differ in education, marital status, living situation, or employment, nor by psychiatric or substance-abuse diagnoses. Both recent and early factors were associated with suicide, including lack of recent clinical care, non-Italian cultural subgroup-membership, familial suicidal behavior, and recent interpersonal distress. Copyright © 2017 Elsevier Inc. All rights reserved.

Underlying Factors for Practicality of the Production Control Systems

DEFF Research Database (Denmark)

Arica, Emrah; Strandhagen, Jan Ola; Hvolby, Hans-Henrik

2012-01-01

and communication technology, coordination and feedback, human factors and decision making, and measurement are the identified factors to be taken into account. Industrial interviews with three case companies, that are participating to the research program called The Norwegian Manufacturing Future (SFI NORMAN......This paper gives indications to important factors that must be considered for effectiveness of the production control systems under uncertainty. Five key factors have been identified by the literature study. Production schedule generation and execution approach under uncertainty, information...

Risk assessment of chemicals in foundries: The International Chemical Toolkit pilot-project

International Nuclear Information System (INIS)

Ribeiro, Marcela G.; Filho, Walter R.P.

2006-01-01

In Brazil, problems regarding protection from hazardous substances in small-sized enterprises are similar to those observed in many other countries. Looking for a simple tool to assess and control such exposures, FUNDACENTRO has started in 2005 a pilot-project to implement the International Chemical Control Toolkit. During the series of visits to foundries, it was observed that although many changes have occurred in foundry technology, occupational exposures to silica dust and metal fumes continue to occur, due to a lack of perception of occupational exposure in the work environment. After introducing the Chemical Toolkit concept to the foundry work group, it was possible to show that the activities undertaken to improve the management of chemicals, according to its concept, will support companies in fulfilling government legislations related to chemical management, occupational health and safety, and environmental impact. In the following meetings, the foundry work group and FUNDACENTRO research team will identify 'inadequate work situations'. Based on the Chemical Toolkit, improvement measures will be proposed. Afterwards, a survey will verify the efficency of those measures in the control of hazards and consequently on the management of chemicals. This step is now in course

Chemical characterization of nuclear fuel materials

International Nuclear Information System (INIS)

Ramakumar, K.L.

2011-01-01

control programme would result in reducing generation of analytical waste especially of plutonium. Selection of the evaluation techniques is made considering various aspects viz. accuracy, reliability, type of testing (non-destructive or otherwise), analysis time etc. In order to meet stringent chemical specifications, analyses of process intermediates and final pellets are essential. It should be realized that nuclear fission occurs only in the fissile atoms (e.g. 235 U or 239 Pu) and during nuclear fission a number of fission products starting from Br to Gd are produced making the nuclear fuel a highly heterogeneous and 'impure' system. But to start with the nuclear fuel should be as pure as possible. But invariably a number of trace impurities are always present in the fuel. There are a number of factors which need to be considered for realizing the designed performance of the nuclear fuel in side the reactor

Risk factors for measles among adults in Tianjin, China: Who should be controls in a case-control study?

Science.gov (United States)

Wagner, Abram L; Boulton, Matthew L; Gillespie, Brenda W; Zhang, Ying; Ding, Yaxing; Carlson, Bradley F; Luo, Xiaoyan; Montgomery, JoLynn P; Wang, Xiexiu

2017-01-01

Control groups in previous case-control studies of vaccine-preventable diseases have included people immune to disease. This study examines risk factors for measles acquisition among adults 20 to 49 years of age in Tianjin, China, and compares findings using measles IgG antibody-negative controls to all controls, both IgG-negative and IgG-positive. Measles cases were sampled from a disease registry, and controls were enrolled from community registries in Tianjin, China, 2011-2015. Through a best subsets selection procedure, we compared which variables were selected at different model sizes when using IgG-negative controls or all controls. We entered risk factors for measles in two separate logistic regression models: one with measles IgG-negative controls and the other with all controls. The study included 384 measles cases and 1,596 community controls (194 IgG-negative). Visiting a hospital was an important risk factor. For specialty hospitals, the odds ratio (OR) was 4.53 (95% confidence interval (CI): 1.28, 16.03) using IgG-negative controls, and OR = 5.27 (95% CI: 2.73, 10.18) using all controls. Variables, such as age or length of time in Tianjin, were differentially selected depending on the control group. Individuals living in Tianjin ≤3 years had 2.87 (95% CI: 1.46, 5.66) times greater odds of measles case status compared to all controls, but this relationship was not apparent for IgG-negative controls. We recommend that case-control studies examining risk factors for infectious diseases, particularly in the context of transmission dynamics, consider antibody-negative controls as the gold standard.

Physical and Chemical Factors Affecting Contaminant Hydrology in Cold Environments

National Research Council Canada - National Science Library

Grant, Steven

2000-01-01

.... The chemical thermodynamics of geochemical solutions below 0 deg C is then reviewed. Particular attention is placed on the physical-chemical properties of ice and liquid water at subzero temperatures...

Risk factors for syphilis in women: case-control study

Directory of Open Access Journals (Sweden)

Vilma Costa de Macêdo

2017-08-01

Full Text Available ABSTRACT OBJECTIVE To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. METHODS This is a case-control study (239 cases and 322 controls with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay. The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. RESULTS The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02, lack of access to telephone (OR = 2.4, catholic religion (OR = 1.70 , four or more pregnancies (OR = 2.2, three or more sexual partners in the last year (OR = 3.1, use of illicit drugs before the age of 18 (OR = 3.0, and use of illicit drugs by the current partner (OR = 1.7. Only one to three prenatal appointments (OR = 3.5 and a previous history of sexually transmitted infection (OR = 9.7 were also identified as determinant factors. CONCLUSIONS Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability.

Risk factors for syphilis in women: case-control study

Science.gov (United States)

de Macêdo, Vilma Costa; de Lira, Pedro Israel Cabral; de Frias, Paulo Germano; Romaguera, Luciana Maria Delgado; Caires, Silvana de Fátima Ferreira; Ximenes, Ricardo Arraes de Alencar

2017-01-01

ABSTRACT OBJECTIVE To determine the sociodemographic, behavioral, and health care factors related to the occurrence of syphilis in women treated at public maternity hospitals. METHODS This is a case-control study (239 cases and 322 controls) with women admitted to seven maternity hospitals in the municipality of Recife, Brazil, from July 2013 to July 2014. Eligible women were recruited after the result of the VDRL (Venereal Disease Research Laboratory) under any titration. The selection of cases and controls was based on the result of the serology for syphilis using ELISA (enzyme-linked immunosorbent assay). The independent variables were grouped into: sociodemographic, behavioral, clinical and obstetric history, and health care in prenatal care and maternity hospital. Information was obtained by interview, during hospitalization, with the application of a questionnaire. Odds ratios and 95% confidence intervals were estimated using logistic regression to identify the predicting factors of the variable to be explained. RESULTS The logistic regression analysis identified as determinant factors for gestational syphilis: education level of incomplete basic education or illiterate (OR = 2.02), lack of access to telephone (OR = 2.4), catholic religion (OR = 1.70 ), four or more pregnancies (OR = 2.2), three or more sexual partners in the last year (OR = 3.1), use of illicit drugs before the age of 18 (OR = 3.0), and use of illicit drugs by the current partner (OR = 1.7). Only one to three prenatal appointments (OR = 3.5) and a previous history of sexually transmitted infection (OR = 9.7) were also identified as determinant factors. CONCLUSIONS Sociodemographic, behavioral, and health care factors are associated with the occurrence of syphilis in women and should be taken into account in the elaboration of universal strategies aimed at the prevention and control of syphilis, but with a focus on situations of greater vulnerability. PMID:28832758

The significance of feedback control for chemical sensors

NARCIS (Netherlands)

Bergveld, Piet

1992-01-01

The conventional way of applying chemical sensors is in an open-loop configuration. A parameter of the chemical domain, such as a gas or ion concentration, is converted into a parameter of the mechanical or electrical domain, often with non-linear transfer characteristics. The paramagnetic oxygen

Potential risk factors for diabetic neuropathy: a case control study

Directory of Open Access Journals (Sweden)

Nooraei Mahdi

2005-12-01

Full Text Available Abstract Background Diabetes mellitus type II afflicts at least 2 million people in Iran. Neuropathy is one of the most common complications of diabetes and lowers the patient's quality of life. Since neuropathy often leads to ulceration and amputation, we have tried to elucidate the factors that can affect its progression. Methods In this case-control study, 110 diabetic patients were selected from the Shariati Hospital diabetes clinic. Michigan Neuropathic Diabetic Scoring (MNDS was used to differentiate cases from controls. The diagnosis of neuropathy was confirmed by nerve conduction studies (nerve conduction velocity and electromyography. The multiple factors compared between the two groups included consumption of angiotensin converting enzyme inhibitors (ACEI, blood pressure, serum lipid level, sex, smoking, method of diabetes control and its quality. Results Statistically significant relationships were found between neuropathy and age, gender, quality of diabetes control and duration of disease (P values in the order: 0.04, 0.04, Conclusion In this study, hyperglycemia was the only modifiable risk factor for diabetic neuropathy. Glycemic control reduces the incidence of neuropathy, slows its progression and improves the diabetic patient's quality of life. More attention must be paid to elderly male diabetic patients with poor diabetes control with regard to regular foot examinations and more practical education.

The effect of biological and chemical additives on the chemical composition and fermentation process of Dactylis glomerata silage

Energy Technology Data Exchange (ETDEWEB)

Alba-Mejía, J.E.; Skladanka, J.; Hilger-Delgado, A.; Klíma, M.; Knot, P.; Doležal, P.; Horky, P.

2016-11-01

This study was carried out to determine the chemical composition, silage quality and ensilability of ten cocksfoot cultivars using biological and chemical silage additives. The plant material was harvested from the first and second cut, cultivated at the Research Station of Fodder Crops in Vatín, Czech Republic. Wilted forage was chopped and ensiled in mini-silos with 3 replicates per treatment. The treatments were: 1) without additives, used as a control; 2) with bacterial inoculants; and 3) with chemical preservatives. The results indicated that the year factor (2012-2013) influenced significantly the chemical composition of the silage in both cuts. The use of biological inoculants reduced the content of crude fibre and acid detergent fibre; but it did not influence the content of neutral detergent fibre, in comparison with the control silage in both cuts. Furthermore, the application of biological inoculants reduced the concentration of lactic acid (LA) and acetic acid (AA) in contrast to the control silage in the first cut. Moreover, in the second cut the same values tended to be the opposite. Interestingly, ‘Amera’ was the unique variety that presented a high concentration of butyric acid (0.2%) in comparison with other varieties in the first cut. In conclusion, the biological inoculants had a favourable effect on silage fermentation. Notably, only ‘Greenly’ and ‘Starly’ varieties from the first cut; and ‘Greenly’, ‘Sw-Luxor’, and ‘Otello’ varieties from the second cut were appropriate for ensiling because their pH-values; LA and AA concentrations were ideal according to the parameters of the fermentation process. (Author)

The effect of biological and chemical additives on the chemical composition and fermentation process of Dactylis glomerata silage

Directory of Open Access Journals (Sweden)

Jhonny E. Alba-Mejía

2016-06-01

Full Text Available This study was carried out to determine the chemical composition, silage quality and ensilability of ten cocksfoot cultivars using biological and chemical silage additives. The plant material was harvested from the first and second cut, cultivated at the Research Station of Fodder Crops in Vatín, Czech Republic. Wilted forage was chopped and ensiled in mini-silos with 3 replicates per treatment. The treatments were: 1 without additives, used as a control; 2 with bacterial inoculants; and 3 with chemical preservatives. The results indicated that the year factor (2012-2013 influenced significantly the chemical composition of the silage in both cuts. The use of biological inoculants reduced the content of crude fibre and acid detergent fibre; but it did not influence the content of neutral detergent fibre, in comparison with the control silage in both cuts. Furthermore, the application of biological inoculants reduced the concentration of lactic acid (LA and acetic acid (AA in contrast to the control silage in the first cut. Moreover, in the second cut the same values tended to be the opposite. Interestingly, ‘Amera’ was the unique variety that presented a high concentration of butyric acid (0.2% in comparison with other varieties in the first cut. In conclusion, the biological inoculants had a favourable effect on silage fermentation. Notably, only ‘Greenly’ and ‘Starly’ varieties from the first cut; and ‘Greenly’, ‘Sw-Luxor’, and ‘Otello’ varieties from the second cut were appropriate for ensiling because their pH-values; LA and AA concentrations were ideal according to the parameters of the fermentation process.

Human factors evaluation of the engineering test reactor control room

International Nuclear Information System (INIS)

Banks, W.W.; Boone, M.P.

1981-03-01

The Reactor and Process Control Rooms at the Engineering Test Reactor were evaluated by a team of human factors engineers using available human factors design criteria. During the evaluation, ETR, equipment and facilities were compared with MIL-STD-1472-B, Human Engineering design Criteria for Military Systems. The focus of recommendations centered on: (a) displays and controls; placing displays and controls in functional groups; (b) establishing a consistent color coding (in compliance with a standard if possible); (c) systematizing annunciator alarms and reducing their number; (d) organizing equipment in functional groups; and (e) modifying labeling and lines of demarcation

The Influence of Soil Chemical Factors on In Situ Bioremediation of Soil Contamination

Energy Technology Data Exchange (ETDEWEB)

Breedveld, Gijs D.

1997-12-31

Mineral oil is the major energy source in Western society. Production, transport and distribution of oil and oil products cause serious contamination problems of water, air and soil. The present thesis studies the natural biodegradation processes in the soil environment which can remove contamination by oil products and creosote. The main physical/chemical processes determining the distribution of organic contaminants between the soil solid, aqueous and vapour phase are discussed. Then a short introduction to soil microbiology and environmental factors important for biodegradation is given. There is a discussion of engineered and natural bioremediation methods and the problems related to scaling up laboratory experiments to field scale remediation. Bioremediation will seldom remove the contaminants completely; a residue remains. Factors affecting the level of residual contamination and the consequences for contaminant availability are discussed. Finally, the main findings of the work are summarized and recommendations for further research are given. 111 refs., 41 figs., 19 tabs.

Community structure, phytoplankton density and physical-chemical factor of batang palangki waters of sijunjung regency, west sumatera

Science.gov (United States)

Gusmaweti; Deswati, L.

2018-03-01

The long-term goal of this study is to provide an overview of the presence of phytoplankton in support of its functions in the waters of Batang Palangki as a conservation area of information on river water management, especially for Batang Palangki stakeholders. Specific targets to be achieved in achieving these objectives are (1) to know the density of phytoplankton, index of diversity of species, equitabilty index, domination index, and in Batang Palangki waters, and (2) to analyze the chemical and physical factors of the waters. The sampling method of phytoplankton is purposive sampling. The phytoplankton sampling is done By filtering 100 liters of water into the net plankton no 25 and filtered into the 25 cc, and then identified. The determination of water quality such as water temperature, water pH and watercolour. dissolved oxygen (DO) and BOD, and Hg content (mercury). The results showed that phytoplankton found from each of station was 370 individualis per liter with the highest density found in the station I of 155. The number of genus was 7, namely Neidium, Gyrogsima, Synedra, Frustulia, Fragillaria, Nitzschia and Peridinium. The diversity index averaged at 0.45, equabilty index averaged at 0.54, while the dominance index averaged at 0.28. Physical and chemical factor measurement results found that water temperature averaged at 26 °C, transparency ranged from 12 - 30 cm, velocity speed ranged from 8 - 15 m/s, while chemical factors such as DO, BOD, and COD ranged from 5.25 to 5.96 mg/L, 3.28 - 3.49 mg/L, and 47.05 - 76.25 mg/L respectively. Likewise, TOM measured in this research was 9.61 - 2.10 mg/L while Hg content ranged from 0.098 - 0.208 mg/L.

The association of the original OSHA chemical hazard communication standard with reductions in acute work injuries/illnesses in private industry and the industrial releases of chemical carcinogens.

Science.gov (United States)

Oleinick, Arthur

2014-02-01

OSHA predicted the original chemical Hazard Communication Standard (HCS) would cumulatively reduce the lost workday acute injury/illness rate for exposure events by 20% over 20 years and reduce exposure to chemical carcinogens. JoinPoint trend software identified changes in the rate of change of BLS rates for days away from work for acute injuries/illnesses during 1992-2009 for manufacturing and nonmanufacturing industries for both chemical, noxious or allergenic injury exposure events and All other exposure events. The annual percent change in the rates was used to adjust observed numbers of cases to estimate their association with the standard. A case-control study of EPA's Toxic Release Inventory 1988-2009 data compared carcinogen and non-carcinogens' releases. The study estimates that the HCS was associated with a reduction in the number of acute injuries/illnesses due to chemical injury exposure events over the background rate in the range 107,569-459,395 (Hudson method/modified BIC model) depending on whether the HCS is treated as a marginal or sole factor in the decrease. Carcinogen releases have declined at a substantially faster rate than control non-carcinogens. The previous HCS standard was associated with significant reductions in chemical event acute injuries/illnesses and chemical carcinogen exposures. © 2013 Wiley Periodicals, Inc.

Factores de necesidad asociados al uso adecuado del control prenatal

Directory of Open Access Journals (Sweden)

Clarybel Miranda Mellado

2016-07-01

Full Text Available Introducción: Por las implicaciones sociales de la mortalidad y morbilidad materna es importante determinar los factores de necesidad que influyen en el uso adecuado del control prenatal en gestantes de Sincelejo. Materiales y Métodos: Estudio analítico de corte transversal, que incluyó 730 gestantes, seleccionadas mediante muestreo aleatorio por conglomerados, de las comunas de la ciudad. La información fue recolectada por medio de una encuesta sociodemográfica, una ficha de uso de control prenatal y un Cuestionario para evaluar los factores de necesidad  propuestos por el Modelo de Promoción de la Salud de Nola Pender. Las gestantes fueron contactadas en sus domicilios y diligenciaron los instrumentos. Los datos fueron analizados aplicando estadística descriptiva e inferencial para determinar las asociaciones entre variables. Resultados: El 97,7% (713 de las gestantes asistía al control prenatal, con una mediana de 4 controles prenatales. Un 2,3% (17 no lo habían iniciado al momento de la encuesta y 24,4% (178 hizo uso inadecuado. El 80,7% (589 de las gestantes califican su estado de salud como bueno o muy bueno, 94,8% (692 percibieron beneficios del control prenatal. Se encontró asociación significativa entre la percepción de beneficios y el uso adecuado de control prenatal [OR=5,5 (IC 95%: 2,8 - 10,8]. Discusión y Conclusiones: La percepción que las mujeres tienen sobre los buenos resultados que reporta la asistencia al control prenatal, es el principal factor que puede explicar la adherencia al control y el cumplimiento regular de las consultas. Cómo citar este artículo: Miranda C, Castillo IY. Factores de necesidad asociados al uso adecuado del control prenatal. Rev Cuid. 2016; 7(2: 1345-51. http://dx.doi.org/10.15649/cuidarte.v7i2.340

Proportional-Integral-Derivative (PID) Control of Secreted Factors for Blood Stem Cell Culture.

Science.gov (United States)

Caldwell, Julia; Wang, Weijia; Zandstra, Peter W

2015-01-01

Clinical use of umbilical cord blood has typically been limited by the need to expand hematopoietic stem and progenitor cells (HSPC) ex vivo. This expansion is challenging due to the accumulation of secreted signaling factors in the culture that have a negative regulatory effect on HSPC output. Strategies for global regulation of these factors through dilution have been developed, but do not accommodate the dynamic nature or inherent variability of hematopoietic cell culture. We have developed a mathematical model to simulate the impact of feedback control on in vitro hematopoiesis, and used it to design a proportional-integral-derivative (PID) control algorithm. This algorithm was implemented with a fed-batch bioreactor to regulate the concentrations of secreted factors. Controlling the concentration of a key target factor, TGF-β1, through dilution limited the negative effect it had on HSPCs, and allowed global control of other similarly-produced inhibitory endogenous factors. The PID control algorithm effectively maintained the target soluble factor at the target concentration. We show that feedback controlled dilution is predicted to be a more cost effective dilution strategy compared to other open-loop strategies, and can enhance HSPC expansion in short term culture. This study demonstrates the utility of secreted factor process control strategies to optimize stem cell culture systems, and motivates the development of multi-analyte protein sensors to automate the manufacturing of cell therapies.

A new approach to evaluate factors controlling elemental sediment–seawater distribution coefficients (K{sub d}) in coastal regions, Japan

Energy Technology Data Exchange (ETDEWEB)

Takata, Hyoe, E-mail: takata@kaiseiken.or.jp [Marine Ecology Research Institute, Central Laboratory, Onjuku, Chiba (Japan); National Institute of Radiological Sciences, Chiba City, Chiba (Japan); Aono, Tatsuo; Tagami, Keiko; Uchida, Shigeo [National Institute of Radiological Sciences, Chiba City, Chiba (Japan)

2016-02-01

In numerical models to simulate the dispersion of anthropogenic radionuclides in the marine environment, the sediment–seawater distribution coefficient (K{sub d}) for various elements is an important parameter. In coastal regions, K{sub d} values are largely dependent on hydrographic conditions and physicochemical characteristics of sediment. Here we report K{sub d} values for 36 elements (Na, Mg, Al, K, Ca, V, Mn, Fe, Co, Ni, Cu, Se, Rb, Sr, Y, Mo, Cd, I, Cs, rare earth elements, Pb, {sup 232}Th and {sup 238}U) in seawater and sediment samples from 19 Japanese coastal regions, and we examine the factors controlling the variability of these K{sub d} values by investigating their relationships to hydrographic conditions and sediment characteristics. There was large variability in K{sub d} values for Al, Mn, Fe, Co, Ni, Cu, Se, Cd, I, Pb and Th. Variations of K{sub d} for Al, Mn, Fe, Co, Pb and Th appear to be controlled by hydrographic conditions. Although K{sub d} values for Ni, Cu, Se, Cd and I depend mainly on grain size, organic matter content, and the concentrations of hydrous oxides/oxides of Fe and Mn in sediments, heterogeneity in the surface characteristics of sediment particles appears to hamper evaluation of the relative importance of these factors. Thus, we report a new approach to evaluate the factors contributing to variability in K{sub d} for an element. By this approach, we concluded that the K{sub d} values for Cu, Se, Cd and I are controlled by grain size and organic matter in sediments, and the K{sub d} value for Ni is dependent on grain size and on hydrous oxides/oxides of Fe and Mn. - Highlights: • K{sub d}s for 36 elements were determined in 19 Japanese coastal regions. • K{sub d}s for several elements appeared to be controlled by multiple factors in sediments. • We evaluated these factors based on physico-chemical characteristics of sediments.

Factors Influencing Prevention and Control of Malaria among ...

African Journals Online (AJOL)

AJRH Managing Editor

investigate factors that influence malaria prevention and control practices among pregnant ... treatment of clinical cases and the promotion of ... influence their decision regarding malaria ..... have the ability to purchase anti-malaria drugs that.

Survey of control-room design practices with respect to human factors engineering

International Nuclear Information System (INIS)

Seminara, J.L.; Parsons, S.O.

1980-01-01

Human factors engineering is an interdisciplinary speciality concerned with influencing the design of equipment systems, facilities, and operational environments to promote safe, efficient, and reliable operator performance. This emphasis has been applied to most military and space systems in the past 30 y. A review of five nuclear power-plant control rooms, reported in the November-December 1977 issue of Nuclear Safety, revealed that human factors principles of design have generally not been incorporated in present-generation control rooms. This article summarizes the findings of a survey of 20 control-board designers from a mix of nuclear steam-supply system and architect-engineering firms. The interviews with these designers probed design methods currently used in developing control rooms. From these data it was concluded that there is currently no consistent, formal, uniform concern for the human factors aspects of control-room design on the part of the design organizations, the utilities, or the Nuclear Regulatory Commission. Although all the parties involved are concerned with human factors issues, this responsibility is not focused, and human factors yardsticks, or design standards, specific to power plants have not been evolved and applied in the development and verification of control-room designs from the standpoint of the man-machine interface

Improved CO sub 2 enhanced oil recovery -- Mobility control by in-situ chemical precipitation

Energy Technology Data Exchange (ETDEWEB)

Ameri, S.; Aminian, K.; Wasson, J.A.; Durham, D.L.

1991-06-01

The overall objective of this study has been to evaluate the feasibility of chemical precipitation to improve CO{sub 2} sweep efficiency and mobility control. The laboratory experiments have indicated that carbonate precipitation can alter the permeability of the core samples under reservoir conditions. Furthermore, the relative permeability measurements have revealed that precipitation reduces the gas permeability in favor of liquid permeability. This indicates that precipitation is occurring preferentially in the larger pores. Additional experimental work with a series of connected cores have indicated that the permeability profile can be successfully modified. However, Ph control plays a critical role in propagation of the chemical precipitation reaction. A numerical reservoir model has been utilized to evaluate the effects of permeability heterogeneity and permeability modification on the CO{sub 2} sweep efficiency. The computer simulation results indicate that the permeability profile modification can significantly enhance CO{sub 2} vertical and horizontal sweep efficiencies. The scoping studies with the model have further revealed that only a fraction of high permeability zones need to be altered to achieve sweep efficiency enhancement. 64 refs., 30 figs., 16 tabs.

Short-term response of Holcus lanatus L. (Common Velvetgrass) to chemical and manual control at Yosemite National Park, USA

Science.gov (United States)

Jones, Laura J.; Ostoja, Steven M.; Brooks, Matthew L.; Hutten, Martin

2015-01-01

One of the highest priority invasive species at both Yosemite and Sequoia and Kings Canyon national parks is Holcus lanatus L. (common velvetgrass), a perennial bunchgrass that invades mid-elevation montane meadows. Despite velvetgrass being a high priority species, there is little information available on control techniques. The goal of this project was to evaluate the short-term response of a single application of common chemical and manual velvetgrass control techniques. The study was conducted at three montane sites in Yosemite National Park. Glyphosate spot-spray treatments were applied at 0.5, 1.0, 1.5, and 2.0% concentrations, and compared with hand pulling to evaluate effects on cover of common velvetgrass, cover of other plant species, and community species richness. Posttreatment year 1 cover of common velvetgrass was 12.1% ± 1.6 in control plots, 6.3% ± 1.5 averaged over the four chemical treatments (all chemical treatments performed similarly), and 13.6% ± 1.7 for handpulled plots. This represents an approximately 50% reduction in common velvetgrass cover in chemically- treated plots recoded posttreatment year 1 and no statistically significant reduction in hand pulled plots compared with controls. However, there was no treatment effect in posttreatment year 2, and all herbicide application rates performed similarly. In addition, there were no significant treatment effects on nontarget species or species richness. These results suggest that for this level of infestation and habitat type, (1) one year of hand pulling is not an effective control method and (2) glyphosate provides some level of control in the short-term without impact to nontarget plant species, but the effect is temporary as a single year of glyphosate treatment is ineffective over a two-year period.

Dealing With A Controllable Risk Factor Like Diet In The ...

African Journals Online (AJOL)

Cardiovascular disease (CVD) is a silent killer in Nigeria and many parts of the world. Certain factors increase the risk of CVD. While there are controllable factors that contribute and predispose to the development of CVD like diet, exercise, tobacco use, high blood pressure and obesity, there are uncontrollable factors like ...

Factors Associated with Long-Term Control of Type 2 Diabetes Mellitus.

Science.gov (United States)

Badedi, Mohammed; Solan, Yahiya; Darraj, Hussain; Sabai, Abdullah; Mahfouz, Mohamed; Alamodi, Saleh; Alsabaani, Abdullah

2016-01-01

Aims. This study assessed factors associated with glycemic control among Saudi patients with Type 2 diabetes mellitus (T2DM). Methods. We conducted an analytical cross-sectional study, which included a random sample of 288 patients with T2DM proportional to the diabetes population of each primary health care center in Jazan city, Kingdom of Saudi Arabia. Results. More than two-thirds (74%) of patients had poor glycemic control. Lack of education, polypharmacy, and duration of diabetes ≥ 7 years were significantly associated with higher glycated hemoglobin (HbA1c). Moreover, patients who were smoker or divorced were significantly more likely to have higher HbA1c. The patients who did not comply with diet or take their medications as prescribed had poor glycemic control. The study found lower HbA1c levels among patients who received family support or had close relationship with their physicians. Similarly, knowledgeable patients towards diabetes or those with greater confidence in ability to manage self-care behaviors had a lower HbA1c. In contrast, risk factors such as depression or stress were significantly correlated with poorer glycemic control. Conclusion. The majority of T2DM patients had poor glycemic control. The study identified several factors associated with glycemic control. Effective and tailored interventions are needed to mitigate exposure to these risk factors. This would improve glycemic control and reduce the risks inherent to diabetes complications.

Factors Associated with Long-Term Control of Type 2 Diabetes Mellitus

Directory of Open Access Journals (Sweden)

Mohammed Badedi

2016-01-01

Full Text Available Aims. This study assessed factors associated with glycemic control among Saudi patients with Type 2 diabetes mellitus (T2DM. Methods. We conducted an analytical cross-sectional study, which included a random sample of 288 patients with T2DM proportional to the diabetes population of each primary health care center in Jazan city, Kingdom of Saudi Arabia. Results. More than two-thirds (74% of patients had poor glycemic control. Lack of education, polypharmacy, and duration of diabetes ≥ 7 years were significantly associated with higher glycated hemoglobin (HbA1c. Moreover, patients who were smoker or divorced were significantly more likely to have higher HbA1c. The patients who did not comply with diet or take their medications as prescribed had poor glycemic control. The study found lower HbA1c levels among patients who received family support or had close relationship with their physicians. Similarly, knowledgeable patients towards diabetes or those with greater confidence in ability to manage self-care behaviors had a lower HbA1c. In contrast, risk factors such as depression or stress were significantly correlated with poorer glycemic control. Conclusion. The majority of T2DM patients had poor glycemic control. The study identified several factors associated with glycemic control. Effective and tailored interventions are needed to mitigate exposure to these risk factors. This would improve glycemic control and reduce the risks inherent to diabetes complications.

Recent applications of Chemical Imaging to pharmaceutical process monitoring and quality control.

Science.gov (United States)

Gowen, A A; O'Donnell, C P; Cullen, P J; Bell, S E J

2008-05-01

Chemical Imaging (CI) is an emerging platform technology that integrates conventional imaging and spectroscopy to attain both spatial and spectral information from an object. Vibrational spectroscopic methods, such as Near Infrared (NIR) and Raman spectroscopy, combined with imaging are particularly useful for analysis of biological/pharmaceutical forms. The rapid, non-destructive and non-invasive features of CI mark its potential suitability as a process analytical tool for the pharmaceutical industry, for both process monitoring and quality control in the many stages of drug production. This paper provides an overview of CI principles, instrumentation and analysis. Recent applications of Raman and NIR-CI to pharmaceutical quality and process control are presented; challenges facing CI implementation and likely future developments in the technology are also discussed.

Soil chemical sensor and precision agricultural chemical delivery system and method

Science.gov (United States)

Colburn, Jr., John W.

1991-01-01

A real time soil chemical sensor and precision agricultural chemical delivery system includes a plurality of ground-engaging tools in association with individual soil sensors which measure soil chemical levels. The system includes the addition of a solvent which rapidly saturates the soil/tool interface to form a conductive solution of chemicals leached from the soil. A multivalent electrode, positioned within a multivalent frame of the ground-engaging tool, applies a voltage or impresses a current between the electrode and the tool frame. A real-time soil chemical sensor and controller senses the electrochemical reaction resulting from the application of the voltage or current to the leachate, measures it by resistivity methods, and compares it against pre-set resistivity levels for substances leached by the solvent. Still greater precision is obtained by calibrating for the secondary current impressed through solvent-less soil. The appropriate concentration is then found and the servo-controlled delivery system applies the appropriate amount of fertilizer or agricultural chemicals substantially in the location from which the soil measurement was taken.

On frequency-weighted coprime factorization based controller reduction

OpenAIRE

Varga, Andras

2003-01-01

We consider the efficient solution of a class of coprime factorization based controller approximation problems by using frequency-weighted balancing related model reduction approaches. It is shown that for some special stability enforcing frequency-weights, the computation of the frequency-weighted controllability and observability grammians can be done by solving reduced order Lyapunov equations. The new approach can be used in conjunction with accuracy enhancing square-root and balancing-fr...

Mitochondrial respiratory control is lost during growth factor deprivation.

Science.gov (United States)

Gottlieb, Eyal; Armour, Sean M; Thompson, Craig B

2002-10-01

The ability of cells to maintain a bioenergetically favorable ATP/ADP ratio confers a tight balance between cellular events that consume ATP and the rate of ATP production. However, after growth factor withdrawal, the cellular ATP/ADP ratio declines. To investigate these changes, mitochondria from growth factor-deprived cells isolated before the onset of apoptosis were characterized in vitro. Mitochondria from growth factor-deprived cells have lost their ability to undergo matrix condensation in response to ADP, which is accompanied by a failure to perform ADP-coupled respiration. At the time of analysis, mitochondria from growth factor-deprived cells were not depleted of cytochrome c and cytochrome c-dependent respiration was unaffected, demonstrating that the inhibition of the respiratory rate is not due to loss of cytochrome c. Agents that disrupt the mitochondrial outer membrane, such as digitonin, or maintain outer membrane exchange of adenine nucleotide, such as Bcl-x(L), restored ADP-dependent control of mitochondrial respiration. Together, these data suggest that the regulation of mitochondrial outer membrane permeability contributes to respiratory control.

Case–control study of breast cancer and exposure to synthetic environmental chemicals among Alaska Native women

Directory of Open Access Journals (Sweden)

Adrianne K. Holmes

2014-11-01

Full Text Available Background: Exposure to environmental chemicals may impair endocrine system function. Alaska Native (AN women may be at higher risk of exposure to these endocrine disrupting chemicals, which may contribute to breast cancer in this population. Objective: To measure the association between exposure to select environmental chemicals and breast cancer among AN women. Design: A case–control study of 170 women (75 cases, 95 controls recruited from the AN Medical Center from 1999 to 2002. Participants provided urine and serum samples. Serum was analyzed for 9 persistent pesticides, 34 polychlorinated biphenyl (PCB congeners, and 8 polybrominated diethyl ether (PBDE congeners. Urine was analyzed for 10 phthalate metabolites. We calculated geometric means (GM and compared cases and controls using logistic regression. Results: Serum concentrations of most pesticides and 3 indicator PCB congeners (PCB-138/158; PCB-153, PCB-180 were lower in case women than controls. BDE-47 was significantly higher in case women (GM=38.8 ng/g lipid than controls (GM=25.1 ng/g lipid (p=0.04. Persistent pesticides, PCBs, and most phthalate metabolites were not associated with case status in univariate logistic regression. The odds of being a case were higher for those with urinary mono-(2-ethylhexyl phthalate (MEHP concentrations that were above the median; this relationship was seen in both univariate (OR 2.16, 95% CI 1.16–4.05, p=0.02 and multivariable (OR 2.43, 95% CI 1.13–5.25, p=0.02 logistic regression. Women with oestrogen receptor (ER–/progesterone receptor (PR-tumour types tended to have higher concentrations of persistent pesticides than did ER+/PR+ women, although these differences were not statistically significant. Conclusions: Exposure to the parent compound of the phthalate metabolite MEHP may be associated with breast cancer. However, our study is limited by small sample size and an inability to control for the confounding effects of body mass index

Human Factors Analysis of Pipeline Monitoring and Control Operations: Final Technical Report

Science.gov (United States)

2008-11-26

The purpose of the Human Factors Analysis of Pipeline Monitoring and Control Operations project was to develop procedures that could be used by liquid pipeline operators to assess and manage the human factors risks in their control rooms that may adv...

Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

Energy Technology Data Exchange (ETDEWEB)

Bae, Ok-Nam [College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung [College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 151-742 (Korea, Republic of); Kim, Eun-Sun [College of Pharmacy, Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan 426-791 (Korea, Republic of); Jeong, Tae Cheon [College of Pharmacy, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Chun, Young-Jin [College of Pharmacy, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Lee, Ai-Young, E-mail: leeay@duih.org [Department of Dermatology, Dongguk University Ilsan Hospital, Goyang 410-773 (Korea, Republic of); Noh, Minsoo, E-mail: minsoo@alum.mit.edu [College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 151-742 (Korea, Republic of)

2015-03-01

Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. - Highlights: • Pro-inflammatory cytokines induced VEGF production in normal human

Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor

International Nuclear Information System (INIS)

Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

2015-01-01

Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. - Highlights: • Pro-inflammatory cytokines induced VEGF production in normal human

Indoor Residential Chemical Exposures as Risk Factors for Asthmaand Allergy in Infants and Children: a Review

Energy Technology Data Exchange (ETDEWEB)

Mendell, M.J.

2006-03-01

Most research into effects of residential indoor air exposures on asthma and allergies has focused on exposures to biologic allergens, moisture and mold, endotoxin, or combustion byproducts. This paper briefly reviews reported findings on associations of asthma or allergy in infants or children with risk factors related to indoor chemical emissions from residential materials or surface coatings. Associations, some strong (e.g., odds ratios up to 13), were reported. The most frequently identified risk factors were formaldehyde, aromatic organic compounds such as toluene and benzene, plastic materials and plasticizers, and recent painting. Exposures and consequent effects from indoor sources may be exacerbated by decreased ventilation. Identified risk factors may be proxies for correlated exposures. Findings suggest the frequent occurrence of important but preventable effects on asthma and allergy in infants and children worldwide from modern residential building materials and coatings.

Thermodynamic chemical energy transfer mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium chemical reactions

International Nuclear Information System (INIS)

Roh, Heui-Seol

2015-01-01

Chemical energy transfer mechanisms at finite temperature are explored by a chemical energy transfer theory which is capable of investigating various chemical mechanisms of non-equilibrium, quasi-equilibrium, and equilibrium. Gibbs energy fluxes are obtained as a function of chemical potential, time, and displacement. Diffusion, convection, internal convection, and internal equilibrium chemical energy fluxes are demonstrated. The theory reveals that there are chemical energy flux gaps and broken discrete symmetries at the activation chemical potential, time, and displacement. The statistical, thermodynamic theory is the unification of diffusion and internal convection chemical reactions which reduces to the non-equilibrium generalization beyond the quasi-equilibrium theories of migration and diffusion processes. The relationship between kinetic theories of chemical and electrochemical reactions is also explored. The theory is applied to explore non-equilibrium chemical reactions as an illustration. Three variable separation constants indicate particle number constants and play key roles in describing the distinct chemical reaction mechanisms. The kinetics of chemical energy transfer accounts for the four control mechanisms of chemical reactions such as activation, concentration, transition, and film chemical reactions. - Highlights: • Chemical energy transfer theory is proposed for non-, quasi-, and equilibrium. • Gibbs energy fluxes are expressed by chemical potential, time, and displacement. • Relationship between chemical and electrochemical reactions is discussed. • Theory is applied to explore nonequilibrium energy transfer in chemical reactions. • Kinetics of non-equilibrium chemical reactions shows the four control mechanisms

Electrostatic spraying in the chemical control of Triozoida limbata (Enderlein) (Hemiptera: Triozidae) in guava trees (Psidium guajava L.).

Science.gov (United States)

Tavares, Rafael M; Cunha, João Par; Alves, Thales C; Bueno, Mariana R; Silva, Sérgio M; Zandonadi, César Hs

2017-06-01

Owing to the difficulty in reaching targets during pesticide applications on guava trees, it is important to evaluate new technologies that may improve pest management. In electrostatic spraying, an electric force is added to the droplets to control their movements such that they are efficiently directed to the target. The present study evaluated the performance of electrostatic and non-electrostatic spraying in the control of the guava psyllid, the deposition of the spray mixture on the leaves and the losses to the soil. The deposition of the spray mixture was up to 2 times greater when using electrostatic spraying in comparison with non-electrostatic application. The losses of the spray mixture to the soil were up to 4 times smaller with the electrostatic spraying. Electrostatic spraying had better control of the psyllid. It was possible to reduce the volume rate of application with electrostatic spraying without adversely affecting the control of the guava psyllid. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Key Factors Controlling the Applicability and Efficiency of Bioremediation of Chlorinated Ethenes In Situ

Science.gov (United States)

Zhang, M.; Yoshikawa, M.; Takeuchi, M.; Komai, T.

2012-12-01

Bioremediation has been considered as one of environmentally friendly and cost effective approaches for cleaning up the sites polluted by organic contaminants, such as chlorinated ethenes. Although bioremediation, in its widest sense, is not new, and many researches have been performed on bioremediation of different kinds of pollutants, an effective design and implication of in situ bioremediation still remains a challenging problem because of the complexity. Many factors may affect the applicability and efficiency of bioremediation of chlorinated ethenes in situ, which include the type and concentration of contaminants, biological, geological and hydro-geological conditions of the site, physical and chemical characteristics of groundwater and soils to be treated, as well as the constraints in engineering. In this presentation, an overview together with a detailed discussion on each factor will be provided. The influences of individual factors are discussed using the data obtained or cited from different sites and experiments, and thus under different environmental conditions. The results of this study illustrated that 1) the establishment of microbial consortium is of crucial importance for a complete degradation of chlorinated ethenes, 2) in situ control of favorable conditions for increasing microbial activities for bio-degradation through a designed pathway is the key to success, 3) the focus of a successful remediation system is to design an effective delivery process that is capable of producing adequate amendment mixing of contaminant-degrading bacteria, appropriate concentrations of electron acceptors, electron donors, and microbial nutrients in the subsurface treatment area.

75 FR 69912 - Pipeline Safety: Control Room Management/Human Factors

Science.gov (United States)

2010-11-16

... 192 and 195 [Docket ID PHMSA-2007-27954] RIN 2137-AE64 Pipeline Safety: Control Room Management/Human... Control Room Management/Human Factors rule at 49 CFR 192.631 and 195.446. The NPRM proposes to expedite... rule and to engage in open discussions with the agency at PHMSA's Control Room Management...

3D microwave cavity with magnetic flux control and enhanced quality factor

Energy Technology Data Exchange (ETDEWEB)

Reshitnyk, Yarema [The University of Queensland, School of Mathematics and Physics, St Lucia (Australia); Jerger, Markus [The University of Queensland, ARC Centre of Excellence for Engineered Quantum Systems, 4072 (Australia); Fedorov, Arkady [The University of Queensland, School of Mathematics and Physics, St Lucia (Australia); The University of Queensland, ARC Centre of Excellence for Engineered Quantum Systems, 4072 (Australia)

2016-12-15

Three-dimensional (3D) microwave cavities have been extensively used for coupling and interacting with superconducting quantum bits (qubits), providing a versatile platform for quantum control experiments and for realizing hybrid quantum systems. While having high quality factors (>10{sup 6}) superconducting cavities do not permit magnetic field control of qubits. In contrast, cavities made of normal metals are transparent to magnetic fields, but experience lower quality factors (∝10{sup 4}). We have created a hybrid cavity which is primarily composed of aluminium but also contains a small copper insert reaching the internal quality factor of ≅10{sup 5}, an order of magnitude improvement over all previously tested normal metal cavities. In order to demonstrate precise magnetic control, we performed spectroscopy of three superconducting qubits, where individual control of each qubit's frequency was exerted with small external wire coils. An improvement in quality factor and magnetic field control makes this 3D hybrid cavity an attractive new element for circuit quantum electrodynamics experiments. (orig.)

Salivary Chemical Factors in Relation with Oral Cancer in Smokers and Non-Smokers: a Literature Review.

Science.gov (United States)

Nosratzehi, Tahereh

2017-12-01

Squamous cell carcinoma of oral cavity is of malignant tumors, which causes cancerous complications. DNA damage, mainly because of products of oxidative stress like reactive oxygen species, is a frequent mutagenic that triggers carcinoma. Smoking increases the probability of cancer incidence. Saliva is the first biological medium to interact with external compounds, especially smoking substances. The present study overviews the salivary level of some remarkable compounds in relation with smoking and squamous cell carcinoma. To collect data, English literature was searched in databases including PubMed, ScienceDirect and Google Scholar. The keywords used for search were as follows: 'Carcinoma, Squamous Cell', 'Smoking', 'Saliva', and 'Biomarkers'. The inclusion criteria were the presence of salivary chemical factors in relation with oral cancer and influence by smoking. Out of 239 found articles, only 56 were selected. Our results demonstrated the potential role of salivary biochemistry to predict and/or treat complications with cancer in both smoker and non-smoker individuals. Changes in concentrations of salivary chemicals including antioxidants, total antioxidant, glutathione and uric acid, epithelial growth factor, cytokine biomarkers, superoxide dismutase activity, and transcriptome were related to squamous cell carcinoma and could be used as potential biomarkers for cancer prognosis; moreover, enhancement of antioxidant level might be a potential treatment.

Performance ratings and personality factors in radar controllers.

Science.gov (United States)

1970-09-01

The purpose of the study was to determine whether primary or second-order personality questionnaire factors were related to job performance ratings on the Employee Appraisal Record in a sample of 264 radar controllers. A Pearson correlation matrix wa...

Controlled fabrication of the strong emission YVO4:Eu3+ nanoparticles and nanowires by microwave assisted chemical synthesis

International Nuclear Information System (INIS)

Huong, Tran Thu; Vinh, Le Thi; Phuong, Ha Thi; Khuyen, Hoang Thi; Anh, Tran Kim; Tu, Vu Duc; Minh, Le Quoc

2016-01-01

In this report, we are presenting the controlled fabrication results of the strong emission YVO 4 : Eu 3+ nanoparticles and nanowires by microwave which is assisted chemical synthesis. The effects of incorporated synthesis conditions such as microwave irradiated powers, pH values and concentration of chemical composition on properties of nanomaterials are also investigated to obtain the controllable size and homogenous morphology. Morphological and optical properties of YVO 4 : Eu 3+ prepared products which have been characterized by X-ray diffraction (XRD), field emission micrcroscopy (FESEM) and photoluminescence spectroscopy. As based from result of synthesized samples, we found that the changing of pH values, microwave irradiated powers and chemical composition rise to change reform the size and shape of materials from nanoparticles (diameter about 20 nm) to wires shape (with about 500÷800 nm length and 10÷20 nm width). The photoluminescence (PL) spectroscopy measurements of YVO 4 : Eu 3+ nanostructure materials under UV excitation showed that: the strong luminescence in red region with narrow lines corresponding to the intra-4f transitions of 5 D 0 – 7 F j (j=1, 2, 3, and 4) of Eu 3+ ions with the highest luminescence intensity of 5 D 0 → 7 F 2 transition. - Highlights: • The strong emission YVO 4 :Eu 3+ nanostructure materials were successfully synthesized by microwave assisted chemical synthesis. • The size, morphology and luminescence of the YVO 4 :Eu 3+ nanostructure materials can be controlled by the solution pH, microwave irradiated powers and chemical composition. • These YVO 4 :Eu 3+ nanostructure materials above can potentially applied in various fields of application, especially in luminescent labeling and visualization in biomedical application.

DECOLORIZATION AND CHEMICAL REGENERATION OF ...

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Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, China ... of chemical method was an attractive economic factor. ... pharmaceutical industries. Today ... enzyme-treated starch. ... liquid, which increases production costs.

Chemical plant factors affecting resistance in sugarcane in against Scirpophaga Nivella f

International Nuclear Information System (INIS)

Ashfaq, M.; Khan, A.; Ali, A.

2003-01-01

The study was conducted during 2000 to determine the role of various chemical plant factors viz., total minerals, nitrogen, fat contents, carbohydrate, macro an micro nutrients in the leaves of five genotypes of sugarcane i.e., BF-162, SPSG-26, L-118, CP-43/33 and CP-72/2086 by correlating the infestation of top borer, Scirpophaga Nivella F. at tillering stage. None of the genotype was found completely resistant to the pest. CP-43/33 and BF-162 proved susceptible and resistant varieties, respectively. Total mineral, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents played a positive and significant role. Phosphorous, carbohydrates, fats and zinc contents played a significant and negative effect on the pest infestation at tillering stage. (author)

Particle size: a missing factor in risk assessment of human exposure to toxic chemicals in settled indoor dust.

Science.gov (United States)

Cao, Zhi-Guo; Yu, Gang; Chen, Yong-Shan; Cao, Qi-Ming; Fiedler, Heidelore; Deng, Shu-Bo; Huang, Jun; Wang, Bin

2012-11-15

For researches on toxic chemicals in settled indoor dust, selection of dust fraction is a critical influencing factor to the accuracy of human exposure risk assessment results. However, analysis of the selection of dust fraction in recent studies revealed that there is no consensus. This study classified and presented researches on distribution of toxic chemicals according to dust particle size and on relationship between dust particle size and human exposure possibility. According to the literature, beyond the fact that there were no consistent conclusions on particle size distribution of adherent fraction, dust with particle size less than 100 μm should be paid more attention and that larger than 250 μm is neither adherent nor proper for human exposure risk assessment. Calculation results based on literature data show that with different selections of dust fractions, analytical results of toxic chemicals would vary up to 10-fold, which means that selecting dust fractions arbitrarily will lead to large errors in risk assessment of human exposure to toxic chemicals in settled dust. Taking into account the influence of dust particle size on risk assessment of human exposure to toxic chemicals, a new methodology for risk assessment of human exposure to toxic chemicals in settled indoor dust is proposed and human exposure parameter systems to settled indoor dust are advised to be established at national and regional scales all over the world. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tobacco control policy development in the European Union: do political factors matter?

NARCIS (Netherlands)

Bosdriesz, Jizzo R.; Willemsen, Marc C.; Stronks, Karien; Kunst, Anton E.

2015-01-01

There has been much variation between European countries in the development of tobacco control policy. Not much is known about the factors that shape this variation. This study aimed to assess the role of political factors in tobacco control policy development. We used data from 11 European

Risk factors for Creutzfeldt-Jakob disease: a reanalysis of case-control studies.

NARCIS (Netherlands)

D.P.W.M. Wientjens (Dorothee); Z. Davanipour; K. Kondo; W.B. Matthews; R.G. Will (Robert); C.M. van Duijn (Cornelia); A. Hofman (Albert)

1996-01-01

textabstractTo review the evidence for risk factors of Creutzfeldt-Jakob disease (CJD), we pooled and reanalyzed the raw data of three case-control studies. The pooled data set comprised 178 patients and 333 control subjects. The strength of association between CJD and putative risk factors was

The genetic origins of biosynthesis and light-responsive control of the chemical UV screen of land plants

International Nuclear Information System (INIS)

Jorgensen, R.

1994-01-01

Most land plants possess the capacity to protect themselves from UV light, and do so by producing pigments that absorb efficiently in the UV-A and UV-B regions of the spectrum while allowing transmission of nearly all photosynthetically useful wavelengths. These UV-absorbing pigments are mainly phenylpropanoids and flavonoids. This chapter summarizes current understanding of the mechanism of UV protection in higher land plants, evaluates the information available from lower land plants and their green-algal relatives, and then considers the possible evolutionary origins of this use of chemical filters for selectively screening UV light from solar radiation. It is proposed that photo control over the biosynthesis of UV-absorbing phenylpropanoids and flavonoids may have evolved in concert with the evolution of the high biosynthetic activity necessary for UV protection. The toxicity of phenylpropanoids and flavonoids has been postulated to have been a barrier to the evolution of an effective chemical UV screen, and that some means for sequestering these compounds and/or for controlling their synthesis probably evolved prior to, or in concert with, the evolution of high rates of biosynthesis. The original photoreceptor and signal transduction system is speculated to have been based on photo isomerization of a phenylpropanoid ester and a pre-existing product feedback mechanism for controlling phenylpropanoid biosynthesis. Understanding the original mechanism for photo control of the chemical UV screen of land plants could be valuable for understanding the adaptability of extant land plants to rising levels of solar UV-B radiation and may suggest genetic strategies for engineering improved UV tolerance in crop plants. (author)

Human factors engineering applied to Control Centre Design of a research nuclear reactor

Energy Technology Data Exchange (ETDEWEB)

Farias, Larissa P. de; Santos, Isaac J.A. Luquetti dos; Carvalho, Paulo V.R., E-mail: larissapfarias@ymail.com [Instituto de Engenharia Nuclear (DENN/SEESC/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab, de Usabilidade e Confiabilidade Humana; Monteiro, Beany G. [Universidade Federal do Rio Janeiro (UFRJ), Rio Janeiro, RJ (Brazil). Departamento de Desenho Industrial

2017-07-01

The Human Factors Engineering (HFE) program is an essential aspect for the design of nuclear installations. The overall aim of the HFE program is the improvement of the operational reliability and safety of plant operation. The HFE program main purpose is to ensure that human factor practices are incorporated into the plant design, emphasizing man-machine interface issues and design improvement of the nuclear reactor Control Centre. The Control Centre of nuclear reactor is a combination of control rooms, control suites and local control stations, which are functionally connected and located on the reactor site. The objective of this paper is to present a design approach for the Control Centre of a nuclear reactor used to produce radioisotopes and for nuclear research, including human factor issues. The design approach is based on participatory design principles, using human factor standards, ergonomic guidelines, and the participation of a multidisciplinary team during all design phases. Using the information gathered, an initial sketch 3D of the Control Centre was developed. (author)

Human factors engineering applied to Control Centre Design of a research nuclear reactor

International Nuclear Information System (INIS)

Farias, Larissa P. de; Santos, Isaac J.A. Luquetti dos; Carvalho, Paulo V.R.; Monteiro, Beany G.

2017-01-01

The Human Factors Engineering (HFE) program is an essential aspect for the design of nuclear installations. The overall aim of the HFE program is the improvement of the operational reliability and safety of plant operation. The HFE program main purpose is to ensure that human factor practices are incorporated into the plant design, emphasizing man-machine interface issues and design improvement of the nuclear reactor Control Centre. The Control Centre of nuclear reactor is a combination of control rooms, control suites and local control stations, which are functionally connected and located on the reactor site. The objective of this paper is to present a design approach for the Control Centre of a nuclear reactor used to produce radioisotopes and for nuclear research, including human factor issues. The design approach is based on participatory design principles, using human factor standards, ergonomic guidelines, and the participation of a multidisciplinary team during all design phases. Using the information gathered, an initial sketch 3D of the Control Centre was developed. (author)

chemical concepts sjif impact factor evaluation [sjif 2012 = 3.963

African Journals Online (AJOL)

Temechegn

Although there seems to be no agreement about the nature of concepts, one can safely say that chemical concepts are ideas about matter. The major problem in teaching chemical concepts, however, is individuals (students) construct their own ideas about matter depending on their previous experiences in a way that in a ...

Frequency of use controls chemical leaching from drinking-water containers subject to disinfection.

Science.gov (United States)

Andra, Syam S; Makris, Konstantinos C; Shine, James P

2011-12-15

Microbial-, and chemical-based burden of disease associated with lack of access to safe water continues to primarily impact developing countries. Cost-effective health risk-mitigating measures, such as of solar disinfection applied to microbial-contaminated water stored in plastic bottles have been increasingly tested in developing countries adversely impacted by epidemic water-borne diseases. Public health concerns associated with chemical leaching from water packaging materials led us to investigate the magnitude and variability of antimony (Sb) and bromine (Br) leaching from reused plastic containers (polyethylene terephthalate, PET; and polycarbonate, PC) subject to UV and/or temperature-driven disinfection. The overall objective of this study was to determine the main and interactive effects of temperature, UV exposure duration, and frequency of bottle reuse on the extent of leaching of Sb and Br from plastic bottles into water. Regardless of UV exposure duration, frequency of reuse (up to 27 times) was the major factor that linearly increased Sb leaching from PET bottles at all temperatures tested (13-47 °C). Leached Sb concentrations (∼360 ng L(-1)) from the highly reused (27 times) PET bottles (minimal Sb leaching from PC bottles, water at much lower concentrations. Additional research on potential leaching of organic chemicals from water packaging materials is deemed necessary under relevant environmental conditions. Copyright © 2011 Elsevier Ltd. All rights reserved.

Factors controlling physico-chemical characteristics in the coastal waters off Mangalore-A multivariate approach

International Nuclear Information System (INIS)

Shirodkar, P.V.; Mesquita, A.; Pradhan, U.K.; Verlekar, X.N.; Babu, M.T.; Vethamony, P.

2009-01-01

Water quality parameters (temperature, pH, salinity, DO, BOD, suspended solids, nutrients, PHc, phenols, trace metals-Pb, Cd and Hg, chlorophyll-a (chl-a) and phaeopigments) and the sediment quality parameters (total phosphorous, total nitrogen, organic carbon and trace metals) were analysed from samples collected at 15 stations along 3 transects off Karnataka coast (Mangalore harbour in the south to Suratkal in the north), west coast of India during 2007. The analyses showed high ammonia off Suratkal, high nitrite (NO 2 -N) and nitrate (NO 3 -N) in the nearshore waters off Kulai and high nitrite (NO 2 -N) and ammonia (NH 3 -N) in the harbour area. Similarly, high petroleum hydrocarbon (PHc) values were observed near the harbour, while phenols remained high in the nearshore waters of Kulai and Suratkal. Significantly, high concentrations of cadmium and mercury with respect to the earlier studies were observed off Kulai and harbour regions, respectively. R-mode varimax factor analyses were applied separately to surface and bottom water data sets due to existing stratification in the water column caused by riverine inflow and to sediment data. This helped to understand the interrelationships between the variables and to identify probable source components for explaining the environmental status of the area. Six factors (each for surface and bottom waters) were found responsible for variance (86.9% in surface and 82.4% in bottom) in the coastal waters between Mangalore and Suratkal. In sediments, 4 factors explained 86.8% of the observed total variance. The variances indicated addition of nutrients and suspended solids to the coastal waters due to weathering and riverine transport and are categorized as natural sources. The observed contamination of coastal waters indicated anthropogenic inputs of Cd and phenol from industrial effluent sources at Kulai and Suratkal, ammonia from wastewater discharges off Kulai and harbour, PHc and Hg from boat traffic and harbour

Chemical control of vegetation on urban sites: agronomic and ecotoxicological aspects

International Nuclear Information System (INIS)

Zanin, G.; Otto, S.

1996-01-01

The problem of the chemical control of spontaneous vegetation on urban sites is tackled. A method is presented to identify the best herbicides under both the agronomic and ecotoxicological aspects. Selection of the herbicides from the agronomic point of view is on the basis of the qualitative characteristics of the vegetation (life-form types periodicity types botanical composition), surveyed at 5 different times on the year while selection from the environmental viewpoint is based on an evaluation integrated with a series of ecotoxicological indices. The best solution was tested in a pilot area and the contamination of the water compartment evaluated both on entering and leaving the water treatment works

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

Directory of Open Access Journals (Sweden)

Elizandra Pivotto Pavanello

2015-12-01

Full Text Available ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole associated with postharvest application of T. harzianum, after cold storage (with and without application, in three evaluation times (zero, two and four days at 20 °C, resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

Chemicals for crop protection and pest control

National Research Council Canada - National Science Library

Green, Maurice B; Hartley, Gilbert Spencer; West, Trustham Frederick

1977-01-01

.... For the most part, the conventional classification into insecticides, herbicides and fungicides has been followed and some more specialized chemicals are also classified according to their biological...

Hazardous Chemicals

Centers for Disease Control (CDC) Podcasts

2007-04-10

Chemicals are a part of our daily lives, providing many products and modern conveniences. With more than three decades of experience, The Centers for Disease Control and Prevention (CDC) has been in the forefront of efforts to protect and assess people's exposure to environmental and hazardous chemicals. This report provides information about hazardous chemicals and useful tips on how to protect you and your family from harmful exposure.  Created: 4/10/2007 by CDC National Center for Environmental Health.   Date Released: 4/13/2007.

Human Factors Engineering Aspects of Modifications in Control Room Modernization

Energy Technology Data Exchange (ETDEWEB)

Hugo, Jacques [Idaho National Lab. (INL), Idaho Falls, ID (United States); Clefton, Gordon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-06-01

This report describes the basic aspects of control room modernization projects in the U.S. nuclear industry and the need for supplementary guidance on the integration of human factors considerations into the licensing and regulatory aspects of digital upgrades. The report pays specific attention to the integration of principles described in NUREG-0711 (Human Factors Engineering Program Review Model) and how supplementary guidance can help to raise general awareness in the industry regarding the complexities of control room modernization projects created by many interdependent regulations, standards and guidelines. The report also describes how human factors engineering principles and methods provided by various resources and international standards can help in navigating through the process of licensing digital upgrades. In particular, the integration of human factors engineering guidance and requirements into the process of licensing digital upgrades can help reduce uncertainty related to development of technical bases for digital upgrades that will avoid the introduction of new failure modes.

Risk Factors for Anemia in Pregnancy: A Case Control Study

Directory of Open Access Journals (Sweden)

Rutuja Pundkar

2017-12-01

Full Text Available Background: Aim of the study was to find the risk factors leading to Anemia in pregnancy. The main objective was to study the various sociodemographic factors leading to anemia. And to assess the knowledge about anemia among study participants. Material and methods: The present Case control study was carried out at Primary Health Centre, to determine the risk factors leading to anemia in pregnancy. A total of 308 pregnant females were registered. Among them two groups were made, group I cases and group II controls. Each group had 50 cases each. Laboratory test were done and females having hemoglobin less than 11mg/dl were considered anemic. Anemic females were considered cases and females having Hb >11mg/dl were considered controls. Data analysis was done using SPSS software. Results: The overall mean haemoglobin (Hb was 11.55g/dL in controls, whereas it was seen that among the cases it was 9.58g/dL.It would seem that diet, family size, education, social class, gravida and parity are associated with anemia in pregnancy. Conclusion: After adjusting for all the possible covariates there seems to be significant association between Hb levels and age group, education level, family size, diet, gravida and parity.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine.

Science.gov (United States)

Gudzenko, N; Hatch, M; Bazyka, D; Dyagil, I; Reiss, R F; Brenner, A; Chumak, V; Babkina, N; Zablotska, L B; Mabuchi, K

2015-10-01

Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. These data - the first from a working population in Ukraine - add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products. Copyright © 2015 Elsevier Inc. All rights reserved.

Factors influencing the control strategy of hybrid drive of urban public transport buses

International Nuclear Information System (INIS)

Barta, Dalibor; Mruzek, Martin

2015-01-01

The efficiency of each drives is dependent on many factors. Hybrid drives and specially the drives of urban public transport may be affected by other factors given by transport infrastructure or operational conditions. These factors condition the suitable configuration of the individual elements of hybrid drive and the establishment of good control strategy of such drive. The study of influencing factors of the control strategy is the aim of this paper. (full text)

Risk factors for idiopathic orbital inflammation: a case-control study

NARCIS (Netherlands)

Bijlsma, Ward R.; van Gils, Carla H.; Paridaens, Dion; Mourits, Maarten P.; Kalmann, Rachel

2011-01-01

Objective To identify risk factors involved in the development of idiopathic orbital inflammation (IOI). Methods Case-control study of 69 adults who had had a first episode of IOI and 296 adult controls with rhegmatogenous retinal detachment (RD) selected from three orbital centres in The

Method and apparatus for continuous monitoring and control of neutron absorption properties of chemical shim with temperature compensation

International Nuclear Information System (INIS)

Schukei, G.E.; Kowles, J.E.

1975-01-01

An apparatus is described to continuously monitor and control the neutron absorption properties of chemical shim used in regulating reactivity of a pressurized water nuclear reactor. Coolant-moderator fluid, containing soluble chemical shim with a neutron absorption property is continuously passed through a chamber having at least one neutron detector spaced from a neutron source of known strength. Utilizing the neutron absorptiometery principle, a signal relating to the concentration of the chemical shim in the coolant-moderator is derived. In addition, the temperature of the sample of coolant is obtained and a temperature compensation signal is generated. The signal related to chemical shim concentration is modified by the temperature compensation signal to correct for temperature related effects. The corrected signal is then applied to a readout and alarm device so that constant monitoring of the shim concentration may be accomplished; additionally, the signal may be applied to maintain the concentration of the chemical shim in the coolant-moderator at a desired level. (U.S.)

Risk Factors Profile of Shoulder Dystocia in Oman: A Case Control Study

OpenAIRE

Maha M. Al-Khaduri; Rania Mohammed Abudraz; Sayed G. Rizvi; Yahya M. Al-Farsi

2014-01-01

Objective: This study aimed to assess the risk factor profile of shoulder dystocia and associated neonatal complications in Oman, a developing Arab country. Methods: A retrospective case-control study was conducted among 111 cases with dystocia and 111 controls, identified during 1994-2006 period in a tertiary care hospital in Oman. Controls were randomly selected among women who did not have dystocia, and were matched to cases on the day of delivery. Data related to potential risk factor...

76 FR 1067 - Testing of Certain High Production Volume Chemicals; Second Group of Chemicals

Science.gov (United States)

2011-01-07

... Mfg & NOES (number based criteria based criteria significant chemicals (lbs) industrial of workers... 2070-AD16 Testing of Certain High Production Volume Chemicals; Second Group of Chemicals AGENCY... section 4(a)(1)(B) of the Toxic Substances Control Act (TSCA) to require manufacturers, importers, and...

Does behaviour modification affect post-stroke risk factor control? Three-year follow-up of a randomized controlled trial.

Science.gov (United States)

McManus, Julie Ann; Craig, Alison; McAlpine, Christine; Langhorne, Peter; Ellis, Graham

2009-02-01

Little is known about the long-term effectiveness after stroke of interventions for behaviour modification and ensuring concordance with therapies. We describe a follow-up study of a previous randomized controlled trial of a brief period of behaviour modification. The aim of this study was to determine outcomes three years after the initial intervention. Survivors of the original cohort were contacted and asked to attend for follow-up interview, within a geriatric day hospital. This study was carried out in the Geriatric Day Hospital at Stobhill Hospital, Balornock Road, Glasgow. Details of risk factor control, including blood pressure, cholesterol levels and diabetic control, were assessed. Questionnaires used in the initial study were repeated including the Geriatric Depression Scale score, Euroqol Perceived Health Status and Stroke Services Satisfaction Questionnaire. Primary outcome was collective risk factor control. Clinical outcomes including recurrent cerebrovascular events, medication persistence and perceived health status were also recorded. Mean length of follow-up was 3.6 years (SD 0.43). Of the 205 patients enrolled in the initial study, 102 patients attended for repeat interview(49 intervention/53 control). There were no significant differences in the percentage of controlled risk factors between groups (intervention 51.7% versus control 55.9%, P = 0.53). Similarities were observed in the number of recurrent clinical events and medication persistence between groups. No overall difference was observed in perceived health status, satisfaction with care or depression scores. Brief intervention with respect to behaviour modification and risk factor control does not appear to have any long-term benefit. These results must be cautiously interpreted in light of the small study number and further research is required.

Verrucomicrobial community structure and abundance as indicators for changes in chemical factors linked to soil fertility.

Science.gov (United States)

Navarrete, Acacio Aparecido; Soares, Tielle; Rossetto, Raffaella; van Veen, Johannes Antonie; Tsai, Siu Mui; Kuramae, Eiko Eurya

2015-09-01

Here we show that verrucomicrobial community structure and abundance are extremely sensitive to changes in chemical factors linked to soil fertility. Terminal restriction fragment length polymorphism fingerprint and real-time quantitative PCR assay were used to analyze changes in verrucomicrobial communities associated with contrasting soil nutrient conditions in tropical regions. In case study Model I ("Slash-and-burn deforestation") the verrucomicrobial community structures revealed disparate patterns in nutrient-enriched soils after slash-and-burn deforestation and natural nutrient-poor soils under an adjacent primary forest in the Amazonia (R = 0.819, P = 0.002). The relative proportion of Verrucomicrobia declined in response to increased soil fertility after slash-and-burn deforestation, accounting on average, for 4 and 2 % of the total bacterial signal, in natural nutrient-poor forest soils and nutrient-enriched deforested soils, respectively. In case study Model II ("Management practices for sugarcane") disparate patterns were revealed in sugarcane rhizosphere sampled on optimal and deficient soil fertility for sugarcane (R = 0.786, P = 0.002). Verrucomicrobial community abundance in sugarcane rhizosphere was negatively correlated with soil fertility, accounting for 2 and 5 % of the total bacterial signal, under optimal and deficient soil fertility conditions for sugarcane, respectively. In nutrient-enriched soils, verrucomicrobial community structures were related to soil factors linked to soil fertility, such as total nitrogen, phosphorus, potassium and sum of bases, i.e., the sum of calcium, magnesium and potassium contents. We conclude that community structure and abundance represent important ecological aspects in soil verrucomicrobial communities for tracking the changes in chemical factors linked to soil fertility under tropical environmental conditions.

Chemical weed control in Spinach (Spiniacia oleracea

Directory of Open Access Journals (Sweden)

A. Modhej

2016-03-01

Full Text Available Introduction Spinach (Spinacia oleracea is an annual plant of family Chenopodiaceae. It is cultivated in temperate and cold regions in Khouzestan in autumn and winter. Weeds are the main problems that limit the production of vegetables. Competition ability of spinach against weeds is very low and weeds cause the loss of quality and quantity in this plant. Weeds reduce germination and establishment and growth of spinach. Weed management in spinach should be done at the beginning of the season. Hand weeding is the best way to control weeds spinach, although due to the high cost it is not cost effective, but is steel common in large areas. Weed control spinach, using chemical methods, the number of weeds are kept below the threshold of economic damage. Materials and Methods The experiment was conducted in a randomized complete block design with 15 treatments and three replications. Treatments included pre-plant application of EPTC at 5 and 6 lit ha-1, pre-plant application of Trifluralin at 2 lit ha-1, pre-plant and pre-emergence application of Pendimethalin at 3 lit ha-1, pre-emergence and post-emergence application of Meteribouzin at 300 g ha-1, pre-emergence and post-emergence application of Meteribouzin at 400 g ha-1, pre-emergence and post-emergence application of Imazethapyr at 0.7 lit ha-1, pre-emergence and post-emergence application of Imazethapyr at 1 lit ha-1, weedy and weed free checks. Each plot the size of 2.5 × 2 meters and 10 row cultivation with distances between rows of 15 cm and the distance between the plants 25 cm and the sowing depth was 3 cm. The herbicide treatments were applied to the back sprayer with Flat fan nozzle with volume of consumption of 240 lit ha-1 solution. The final harvest was about 50 days after emergence. Sampling of weeds 10 days before harvest was performed with using quadrate 0.5 ×0.5. Results Discussion Important broad-leaf and narrow leaf weeds observed in the field, included field bindweed

Integrated application of human factors to a power plant control room information system

International Nuclear Information System (INIS)

Fish, H.C. Jr.; Gutierrez, R.

1988-01-01

The human factors plan was developed as a methodology to apply human factors from the conceptual design of the EPIC system to the functional verification conducted at the plant. An integral part of the Human Factors Plan was the Functional Verification Plan. Developed in parallel, this second plan and its resultant programs verified functional appropriateness of the SPDS display, NSSS displays, EOP displays, man-machine interfaces (MMI), and workstation designs. The functional verification process was performed at the hardware/software developer's factory and at the JAFNPP, following installation of the EPIC system. Because the EPIC system replaces existing control room equipment, it is important that human factors be applied in a systematic manner consistent with other control room displays and controls. To ensure that this goal was met, a human factors plan was developed

Chemical allergens stimulate human epidermal keratinocytes to produce lymphangiogenic vascular endothelial growth factor.

Science.gov (United States)

Bae, Ok-Nam; Ahn, Seyeon; Jin, Sun Hee; Hong, Soo Hyun; Lee, Jinyoung; Kim, Eun-Sun; Jeong, Tae Cheon; Chun, Young-Jin; Lee, Ai-Young; Noh, Minsoo

2015-03-01

Allergic contact dermatitis (ACD) is a cell-mediated immune response that involves skin sensitization in response to contact with various allergens. Angiogenesis and lymphangiogenesis both play roles in the allergic sensitization process. Epidermal keratinocytes can produce vascular endothelial growth factor (VEGF) in response to UV irradiation and during wound healing. However, the effect of haptenic chemical allergens on the VEGF production of human keratinocytes, which is the primary contact site of toxic allergens, has not been thoroughly researched. We systematically investigated whether immune-regulatory cytokines and chemical allergens would lead to the production of VEGF in normal human keratinocytes (NHKs) in culture. VEGF production significantly increased when NHKs were treated with IFNγ, IL-1α, IL-4, IL-6, IL-17A, IL-22 or TNFα. Among the human sensitizers listed in the OECD Test Guideline (TG) 429, we found that CMI/MI, DNCB, 4-phenylenediamine, cobalt chloride, 2-mercaptobenzothiazole, citral, HCA, cinnamic alcohol, imidazolidinyl urea and nickel chloride all significantly upregulated VEGF production in NHKs. In addition, common human haptenic allergens such as avobenzone, formaldehyde and urushiol, also induced the keratinocyte-derived VEGF production. VEGF upregulation by pro-inflammatory stimuli, IFNγ, DNCB or formaldehyde is preceded by the production of IL-8, an acute inflammatory phase cytokine. Lymphangiogenic VEGF-C gene transcription was significantly increased when NHKs were treated with formaldehyde, DNCB or urushiol, while transcription of VEGF-A and VEGF-B did not change. Therefore, the chemical allergen-induced VEGF upregulation is mainly due to the increase in lymphangiogenic VEGF-C transcription in NHKs. These results suggest that keratinocyte-derived VEGF may regulate the lymphangiogenic process during the skin sensitization process of ACD. Copyright © 2015 Elsevier Inc. All rights reserved.

Low-intensity laser coupled with photosensitizer to reduce bacteria in root canals compared to chemical control

International Nuclear Information System (INIS)

Garcez Segundo, Aguinaldo Silva

2002-01-01

The photodynamic therapy is a process in which a dye is associate with an appropriate wavelength of light and this dye goes to an excited state. The excited reacts with oxygen to form the highly reactive compound singlet oxygen, and this compound can kill bacteria and tumor cells. The purpose of this study was to evaluate the bactericidal reduction in root canal contaminated with E. Faecalis. Thirty teeth with their root canals prepared were contaminated with E. faecalis. The teeth have received the chemical substance sodium hypochlorite for 30 minutes; ten teeth have received the azulene dye paste for 5 minutes and have been irradiated with a diode laser, output power 10 mW and λ= 685 nm for 3 minutes. Ten teeth have not received treatment (control group). The bacterial reduction was significantly higher for laser group when compared to chemical and control groups. These results indicate photodynamic therapy as an effective method to kill bacteria. (author)

Controle químico da mancha-bacteriana do tomate para processamento industrial em campo Field chemical control of bacterial spot on tomato for industrial processing

Directory of Open Access Journals (Sweden)

Abadia dos R Nascimento

2013-03-01

cloretos de benzalcônio. ASM e famoxadona + mancozebe foram os que promoveram uma relação benefício/custo superior a 1.In order to evaluate chemical control of bacterial spot on tomato for industrial processing, two field trials were carried out at the Unilever Bestfoods experimental station, in Goiânia, Goias state, Brazil. The first trial was in a randomized complete block design, with 15 treatments and three replications, using the hybrid Heinz 9992 inoculated with Xanthomonas perforans. The second trial was in a split-plot randomized complete block design with chemical foliar applications (10 treatments and hybrids (Hypeel 108 and U2006 as factors. Plants were inoculated with X. perforans and X. gardneri. In both trials the chemicals, in different number of applications and combinations, were: acibenzolar-S-methyl (ASM; famoxadone + mancozeb; metiram + pyraclostrobin; phosphite PK; benzalkonium chlorides; cuprous oxide, and copper hydroxide (SC, WP and WG. For both trials, disease severity on leaves, number of fruits with symptoms and yield were evaluated. In the second one, sunscald was also evaluated. For the first trial, significant severity differences (p>0.05 among treatments were observed only in the first two evaluations, but none of them differed from the water check control. In the second trial, significant differences were detected only in foliar severity in first evaluation for hybrids. For number of fruits with symptoms and sunscald, besides hybrids, interaction among factors was also significant. 'U2006' was more resistant than 'Hypeel 108', which also had highest sunscald values, but concerning fruits with symptoms, the opposite was observed. The two factors were significant for yield data, 'U2006' yielded better than 'Hypeel 108'. Despite none of the treatments have differed in yield from the water control, famoxadone + mancozeb, which resulted in the highest yield, differed from copper hydroxide, ASM - famoxadone + mancozeb, and benzalkonium

Water chemical control of the TRIGA IPR-R1 reactor primary cooling system

International Nuclear Information System (INIS)

Auler, Lucia M.L.A; Chaves, Renata D.A.; Palmieri, Helena E.L.; Menezes, Maria Angela de B.C.; Oliveira, Paulo F.; Kastner, Geraldo F.; Damazio, Ilza; Fagundes, Oliene dos R.; Cintra, Maria Olivia C.; Andrade, Geraldo V. de; Amaral, Angela M.; Franco, Milton B.; Fortes, Flavio; Gomes, Nilton Carlos; Vidal, Andrea; Maretti Junior, Fausto; Knupp, Eliana A.N.; Souza, Wagner de; Guedes, Joao B.; Furtado, Renato C.S.

2013-01-01

The TRIGA Mark I IPR-R1 reactor located at CDTN/CNEN has been in operation and contributed to research and with services to society since 1960. Is has been used in several activities such as nuclear power plant operation, graduate and post-graduate training courses, isotope production, and as an analytical irradiation tool of different types of samples. Among the several structural and operational safety requirements is the chemical quality control of the primary circuit cooling water. The aim of this work was to check the cooling water quality from the pool reactor. A water sampling plan was proposed (May, 2011 - June, 2012) and presents the results obtained in this period. The natural radioactivity level as gross alpha and gross beta activity and other chemical parameters (pH and electric conductivity) of the samples were analyzed. Some instrumental techniques were used: potentiometric methods (pH), conductometric methods (electrical conductivity, EC) and gross α and gross β proportional counting system). (author)

Controlled density of vertically aligned carbon nanotubes in a triode plasma chemical vapor deposition system

International Nuclear Information System (INIS)

Lim, Sung Hoon; Park, Kyu Chang; Moon, Jong Hyun; Yoon, Hyun Sik; Pribat, Didier; Bonnassieux, Yvan; Jang, Jin

2006-01-01

We report on the growth mechanism and density control of vertically aligned carbon nanotubes using a triode plasma enhanced chemical vapor deposition system. The deposition reactor was designed in order to allow the intermediate mesh electrode to be biased independently from the ground and power electrodes. The CNTs grown with a mesh bias of + 300 V show a density of ∼ 1.5 μm -2 and a height of ∼ 5 μm. However, CNTs do not grow when the mesh electrode is biased to - 300 V. The growth of CNTs can be controlled by the mesh electrode bias which in turn controls the plasma density and ion flux on the sample

Optimizing Chemical Reactions with Deep Reinforcement Learning.

Science.gov (United States)

Zhou, Zhenpeng; Li, Xiaocheng; Zare, Richard N

2017-12-27

Deep reinforcement learning was employed to optimize chemical reactions. Our model iteratively records the results of a chemical reaction and chooses new experimental conditions to improve the reaction outcome. This model outperformed a state-of-the-art blackbox optimization algorithm by using 71% fewer steps on both simulations and real reactions. Furthermore, we introduced an efficient exploration strategy by drawing the reaction conditions from certain probability distributions, which resulted in an improvement on regret from 0.062 to 0.039 compared with a deterministic policy. Combining the efficient exploration policy with accelerated microdroplet reactions, optimal reaction conditions were determined in 30 min for the four reactions considered, and a better understanding of the factors that control microdroplet reactions was reached. Moreover, our model showed a better performance after training on reactions with similar or even dissimilar underlying mechanisms, which demonstrates its learning ability.

Human-factors engineering-control-room design review: Shoreham Nuclear Power Station. Draft audit report

International Nuclear Information System (INIS)

Peterson, L.R.; Preston-Smith, J.; Savage, J.W.; Rousseau, W.F.

1981-01-01

A human factors engineering preliminary design review of the Shoreham control room was performed at the site on March 30 through April 3, 1981. This design review was carried out by a team from the Human Factors Engineering Branch, Division of Human Factors Safety. This report was prepared on the basis of the HFEB's review of the applicant's Preliminary Design Assessment and the human factors engineering design review/audit performed at the site. The presented sections are numbered to conform to the guidelines of the draft version of NUREG-0700. They summarize the teams's observations of the control room design and layout, and of the control room operators' interface with the control room environment

Ranking malaria risk factors to guide malaria control efforts in African highlands.

Science.gov (United States)

Protopopoff, Natacha; Van Bortel, Wim; Speybroeck, Niko; Van Geertruyden, Jean-Pierre; Baza, Dismas; D'Alessandro, Umberto; Coosemans, Marc

2009-11-25

Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Active Power Factor Correction Using a Sliding Mode Controller

Directory of Open Access Journals (Sweden)

Korhan KAYIŞLI

2008-03-01

Full Text Available In this paper, a sliding mode controller is designed for active shaping of the input current in the boost converter. Robustness of the designed controller is tested with variable output voltage references, different loads and network voltage variations. For the simulations, MATLAB/Simulink programme is used. From simulation results, the same phase was provided between input current and input voltage and nearly unity power factor was obtained.

Factors to consider in the use of stem cells for pharmaceutic drug development and for chemical safety assessment

International Nuclear Information System (INIS)

Trosko, James Edward; Chang, Chia-Cheng

2010-01-01

Given the reality of the inadequacies of current concepts of the mechanisms of chemical toxicities, of the various assays to predict toxicities from current molecular, biochemical, in vitro and animal bioassays, and of the failure to generate efficacious and safe chemicals for medicines, food supplements, industrial, consumer and agricultural chemicals, the recent NAS Report, 'Toxicity Testing in the 21st Century: A Vision and a Strategy', has drawn attention to a renewed examination of what needs to be done to improve our current approach for better assessment of potential risk to human health. This 'Commentary' provides a major paradigm challenge to the current concepts of how chemicals induce toxicities and how these various mechanisms of toxicities can contribute to the pathogenesis of some human diseases, such as birth defects and cancer. In concordance with the NAS Report to take '... advantage of the on-going revolution in biology and biotechnology', this 'Commentary' supports the use of human embryonic and adult stem cells, grown in vitro under simulated 'in vivo niche conditions'. The human being should be viewed 'as greater than the sum of its parts'. Homeostatic control of the 'emergent properties' of the human hierarchy, needed to maintain human health, requires complex integration of endogenous and exogenous signaling molecules that control cell proliferation, differentiation, apoptosis and senescence of stem, progenitor and differentiated cells. Currently, in vitro toxicity assays (mutagenesis, cytotoxicity, epigenetic modulation), done on 2-dimensional primary rodent or human cells (which are always mixtures of cells), on immortalized or tumorigenic rodent or human cell lines do not represent normal human cells in vivo [which do not grow on plastic and which are in micro-environments representing 3 dimensions and constantly interacting factors]. In addition, with the known genetic, gender, and developmental state of cells in vivo, any in vitro

Factors affecting sustainable animal trypanosomosis control in parts ...

African Journals Online (AJOL)

This study examined the factors affecting sustainable trypanosomiasis control in parts of Kaduna State within the sub-humid savannah ecological zone of Nigeria. Focus group discussions were ... More awareness and preference for pour-on and aerial spraying were higher than the use of traps, target or screens. Rearing of ...

Interactive effects of chemical and biological controls on food-web composition in saline prairie lakes.

Science.gov (United States)

Cooper, Ryan N; Wissel, Björn

2012-11-27

Salinity is restricting habitatability for many biota in prairie lakes due to limited physiological abilities to cope with increasing osmotic stress. Yet, it remains unclear how salinity effects vary among major taxonomic groups and what role other environmental parameters play in shaping food-web composition. To answer these questions, we sampled fish, zooplankton and littoral macroinvertebrates in 20 prairie lakes (Saskatchewan, Canada) characterized by large gradients in water chemistry and lake morphometry. We showed that salinity thresholds differed among major taxonomic groups, as most fishes were absent above salinities of 2 g L-1, while littoral macroinvertebrates were ubiquitous. Zooplankton occurred over the whole salinity range, but changed taxonomic composition as salinity increased. Subsequently, the complexity of fish community (diversity) was associated with large changes in invertebrate communities. The directional changes in invertebrate communities to smaller taxa indicated that complex fish assemblages resulted in higher predation pressure. Most likely, as the complexity of fish community decreased, controls of invertebrate assemblages shifted from predation to competition and ultimately to productivity in hypersaline lakes. Surprisingly, invertebrate predators did not thrive in the absence of fishes in these systems. Furthermore, the here identified salinity threshold for fishes was too low to be a result of osmotic stress. Hence, winterkill was likely an important factor eliminating fishes in low salinity lakes that had high productivity and shallow water depth. Ultimately, while salinity was crucial, intricate combinations of chemical and biological mechanisms also played a major role in controlling the assemblages of major taxonomic groups in prairie lakes.

Chemical reactions confined within carbon nanotubes.

Science.gov (United States)

Miners, Scott A; Rance, Graham A; Khlobystov, Andrei N

2016-08-22

In this critical review, we survey the wide range of chemical reactions that have been confined within carbon nanotubes, particularly emphasising how the pairwise interactions between the catalysts, reactants, transition states and products of a particular molecular transformation with the host nanotube can be used to control the yields and distributions of products of chemical reactions. We demonstrate that nanoscale confinement within carbon nanotubes enables the control of catalyst activity, morphology and stability, influences the local concentration of reactants and products thus affecting equilibria, rates and selectivity, pre-arranges the reactants for desired reactions and alters the relative stability of isomeric products. We critically evaluate the relative advantages and disadvantages of the confinement of chemical reactions inside carbon nanotubes from a chemical perspective and describe how further developments in the controlled synthesis of carbon nanotubes and the incorporation of multifunctionality are essential for the development of this ever-expanding field, ultimately leading to the effective control of the pathways of chemical reactions through the rational design of multi-functional carbon nanoreactors.

Evaluation of chemical stabilizers and windscreens for wind erosion control of uranium mill tailings

International Nuclear Information System (INIS)

Elmore, M.R.; Hartley, J.N.

1984-08-01

Potential wind erosion of uranium mill tailings is a concern for the surface disposal of tailings at uranium mills. Wind-blown tailings may subsequently be redeposited on areas outside the impoundment. Pacific Northwest Laboratory (PNL) is investigating techniques for fugitive dust control at uranium mill tailings piles. Laboratory tests, including wind tunnel studies, were conducted to evaluate the relative effectiveness of 43 chemical stabilizers. Seventeen of the more promising stabilizers were applied to test plots on a uranium tailings pile at the American Nuclear Corporation-Gas Hills Project mill site in central Wyoming. The durabilities of these materials under actual site conditions were evaluated over time. In addition, field testing of commercially available windscreens was conducted. Test panels were constructed of eight different materials at the Wyoming test site to compare their durability. A second test site was established near PNL to evaluate the effectiveness of windscreens at reducing wind velocity, and thereby reduce the potential for wind erosion of mill tailings. Results of the laboratory land field tests of the chemical stabilizers and windscreens are presented, along with costs versus effectiveness of these techniques for control of wind erosion at mill tailings piles. 12 references, 4 figures, 6 tables

[Chemical composition and content of antiphysiological factors of jojoba (Simmondsia chinensis) residual meal].

Science.gov (United States)

Pérez-Gil, F; Sanginés, G L; Torreblanca, R A; Grande, M L; Carranco, J M

1989-12-01

Jojoba (Simmondsia chinensis) is a perennial plant with an interesting economic value by processing it for liquid wax production. By pressing of jojoba seeds, by-product which has been called "residual meal" has been obtained, and because of its high protein content, it would be a great interest to evaluate it as animal feedstuff. The results of this study showed the following. Both seed and residual meal were analyzed in regard to their chemical proximal composition: crude protein 14.03 and 25.24%; ether extract, 48.89 and 14.73%; crude fiber, 10.03 and 10.07%; ash, 1.59 and 4.72, and nitrogen-free extract, 25.46 and 45.25, the limiting amino acids being methionine, lysine and isoleucine. The trypsin inhibitor factors were 13.747 and 11,197 TIU/g; and hemagglutinins and saponins were negative for both samples. Cyanogenic glucosides were positive in both samples. It was concluded that jojoba residual meal is an alternative as an adequate feedstuff in those regions where jojoba is produced. Nevertheless, prior to consumption it must be treated so as to eliminate the toxic factors.

Chemical and biological control of Sclerotinia stem rot in the soybean crop

Directory of Open Access Journals (Sweden)

Ciro Hideki Sumida

2015-05-01

Full Text Available It was evaluated the effect of fungicides and the microbial control agent Trichoderma harzianum on the inhibition of the carpogenic and ascospore germination of Sclerotinia sclerotiorum. This study also evaluated the chemical, fungicidal and microbial control of white mold or Sclerotinia stem rot of soybean in the field. Three experiments were conducted, as follows: 1 inhibition of carpogenic germination of sclerotia, 2 inhibition of ascospore germination, and 3 control of Sclerotinia stem rot in a soybean crop under field conditions. The treatments evaluated were fluazinam, procymidone, iprodione, thiophanate-methyl, carbendazim, benzalkonium chloride + fluazinam, and T. harzianum. Procymidone resulted in an inhibition of 13.5% and benzalkonium chloride in an inhibition of 13.9% in an ascospore germination test. Fluazinam and procymidone were the most effective in reducing the production of ascospores/apothecium, representing 65.6% and 82.4% of inhibition. Procymidone and fluazinam if combined or not with benzalkonium chloride were the most effective in controlling sclerotinia stem rot under field conditions when applied at the onset of flowering and 15 days later. In the 2009-10 harvest, these two fungicides reduced the incidence of Sclerotinia stem rot by 73.1 and 71.6% and in the 2010-11 harvest by 75.7 and 77.6%, respectively.

[Asthma control status in children and related factors in 29 cities of China].

Science.gov (United States)

Zhao, Jing

2013-02-01

To investigate the status of asthma control in the city and severity of asthma in children and to identify related factors. This study was conducted in one children's hospital or tertiary hospital in each of the 29 provinces except Xinjiang and Xizang Autonomous Regions. Totally, 2960 parents with asthmatic children ages 0 to 14 years, and all had been diagnosed with asthma at least 3 months ago and the course was more than 12 months, who visited those hospitals were selected for the knowledge, attitude, and practice (KAP) questionnaire survey, and separated into the controlled asthma group and uncontrolled asthma group according to children's asthma conditions in the past 12 months. Multivariate analysis was carried out based on the answers to 28 tested factors; 2485 of 2960 questionnaires from 29 provinces were valid. Of the 2485 valid questionnaires, 66.0% asthmatic children had asthma attacks in the past 12 months, 26.8% asthmatic children had visited the emergency department, 16.2% asthmatic children had been hospitalized. The total cost was significantly higher in the uncontrolled group than in contro group (χ² = 23.14, P asthma control, knowledge of "3 or more times recurrent wheezing suggesting asthma", knowledge of "cough lasting for more than 4 weeks suggesting asthma", knowledge of "cough improved with bronchodilators suggesting asthma", knowledge of "awareness of using short-acting β₂ agonist for acute attack", avoiding contact with plush toys, adhere to use nasal steroid, inhaled corticosteroids/composite preparation, age of children and course of asthma in children are protective factors that affect asthma control and severity of asthma in children. Food allergies, eczema and family history of asthma are risk factors. Asthma in many children was poorly controlled. Factors that affect asthma control and severity include parents' knowledge about asthma, exposure to adverse environment, the compliance with medication and regular visits for asthma

Controlling the resistivity gradient in aluminum-doped zinc oxide grown by plasma-enhanced chemical vapor deposition

NARCIS (Netherlands)

Ponomarev, M.; Verheijen, M.A.; Keuning, W.; Sanden, van de M.C.M.; Creatore, M.

2012-01-01

Aluminum-doped ZnO (ZnO:Al) grown by chemical vapor deposition (CVD) generally exhibit a major drawback, i.e., a gradient in resistivity extending over a large range of film thickness. The present contribution addresses the plasma-enhanced CVD deposition of ZnO:Al layers by focusing on the control

Conditionally controlling nuclear trafficking in yeast by chemical-induced protein dimerization.

Science.gov (United States)

Xu, Tao; Johnson, Cole A; Gestwicki, Jason E; Kumar, Anuj

2010-11-01

We present here a protocol to conditionally control the nuclear trafficking of target proteins in yeast. In this system, rapamycin is used to heterodimerize two chimeric proteins. One chimera consists of a FK506-binding protein (FKBP12) fused to a cellular 'address' (nuclear localization signal or nuclear export sequence). The second chimera consists of a target protein fused to a fluorescent protein and the FKBP12-rapamycin-binding (FRB) domain from FKBP-12-rapamycin associated protein 1 (FRAP1, also known as mTor). Rapamycin induces dimerization of the FKBP12- and FRB-containing chimeras; these interactions selectively place the target protein under control of the cell address, thereby directing the protein into or out of the nucleus. By chemical-induced dimerization, protein mislocalization is reversible and enables the identification of conditional loss-of-function and gain-of-function phenotypes, in contrast to other systems that require permanent modification of the targeted protein. Yeast strains for this analysis can be constructed in 1 week, and the technique allows protein mislocalization within 15 min after drug treatment.

Risk control in the laboratory

International Nuclear Information System (INIS)

Vermeeren, H.P.W.; Zwaard, A.W.

1986-01-01

This volume contains the knowledge which is needed for safely working in a laboratory. With the help of the contents it is possible to come, after an evaluation of the risks, to practical measures (risk control). Not only exposure to chemicals but also to other burdening factors (radiation, sound, radioactive materials, micro-organisms) are discussed. A general strategy for risk control forms the central point in this book. 51 refs.; 67 figs.; 29 tabs

Study Design for a Case Control Investigation of Cellular Telephones and Other Risk Factors for Brain Tumors in Adults

International Nuclear Information System (INIS)

Inskip, P.D.; Hatch, E.E.; Stewart, P.A.; Heineman, E.F.; Ziegler, R.G.; Dosemeci, M.; Parry, D.; Rothman, N.; Boice, J.D. Jr.; Wilcosky, T.C.; Watson, D.J.; Shapiro, W.R.; Selker, R.G.; Fine, H.A.; Black, P. McL.; Loeffler, J.S.; Linet, M.S.

1999-01-01

The aetiology of brain tumours is poorly understood. Due, in part, to public concern about a postulated relationship between the use of cellular telephones or other increasingly prevalent environmental exposures and the incidence of brain cancer in adults, the National Cancer Institute is collaborating with three US hospitals in a comprehensive case control study of malignant and benign brain tumours. Factors under consideration include use of cellular phones and other wireless communication devices, workplace exposures to chemical agents and electromagnetic fields, dietary factors, family history of tumours, genetic determinants of susceptibility, home appliance use, reproductive history and hormonal exposures, viruses, medical and dental exposure to ionising radiation, and other aspects of medical history. Approximately 800 newly diagnosed brain tumour cases and 800 controls were enrolled at hospitals in Boston, Phoenix and Pittsburgh from 1994 to 1998. Cases include all adults (age ≥ 18 y) newly diagnosed with a histologically confirmed intracranial glioma, histologically confirmed intracranial meningioma or acoustic neuroma. Controls are patients admitted to the same hospitals as the cases, and treated for any of a variety of non-malignant conditions. Key features of the study include its large size, the emphasis on rapid ascertainment of incident cases and interview of study subjects rather than surrogate respondents, the use of detailed, job-specific questions developed by industrial hygienists to ascertain occupational exposures, and the storage of blood samples for future evaluation of inherited susceptibility, biomarkers of exposure and gene environment interactions. (author)

Occupation and occupational exposure to endocrine disrupting chemicals in male breast cancer: a case-control study in Europe

DEFF Research Database (Denmark)

Villeneuve, Sara; Cyr, Diane; Lynge, Elsebeth

2010-01-01

Male breast cancer is a rare disease of largely unknown aetiology. In addition to genetic and hormone-related risk factors, a large number of environmental chemicals are suspected of playing a role in breast cancer. The identification of occupations or occupational exposures associated with an in...

Temporally controlled growth factor delivery from a self-assembling peptide hydrogel and electrospun nanofibre composite scaffold.

Science.gov (United States)

Bruggeman, Kiara F; Wang, Yi; Maclean, Francesca L; Parish, Clare L; Williams, Richard J; Nisbet, David R

2017-09-21

Tissue-specific self-assembling peptide (SAP) hydrogels designed based on biologically relevant peptide sequences have great potential in regenerative medicine. These materials spontaneously form 3D networks of physically assembled nanofibres utilising non-covalent interactions. The nanofibrous structure of SAPs is often compared to that of electrospun scaffolds. These electrospun nanofibers are produced as sheets that can be engineered from a variety of polymers that can be chemically modified to incorporate many molecules including drugs and growth factors. However, their macroscale morphology limits them to wrapping and bandaging applications. Here, for the first time, we combine the benefits of these systems to describe a two-component composite scaffold from these biomaterials, with the design goal of providing a hydrogel scaffold that presents 3D structures, and also has temporal control over drug delivery. Short fibres, cut from electrospun scaffolds, were mixed with our tissue-specific SAP hydrogel to provide a range of nanofibre sizes found in the extracellular matrix (10-300 nm in diameter). The composite material maintained the shear-thinning and void-filling properties of SAP hydrogels that have previously been shown to be effective for minimally invasive material injection, cell delivery and subsequent in vivo integration. Both scaffold components were separately loaded with growth factors, important signaling molecules in tissue regeneration whose rapid degradation limits their clinical efficacy. The two biomaterials provided sequential growth factor delivery profiles: the SAP hydrogel provided a burst release, with the release rate decreasing over 12 hours, while the electrospun nanofibres provided a more constant, sustained delivery. Importantly, this second release commenced 6 days later. The design rules established here to provide temporally distinct release profiles can enable researchers to target specific stages in regeneration, such as the

Evaluation of some microbial agents, natural and chemical compounds for controlling tomato leaf miner, Tuta absoluta (Meyrick (Lepidoptera: Gelechiidae

Directory of Open Access Journals (Sweden)

Abd El-Ghany Nesreen M.

2016-12-01

Full Text Available Solanaceous plants have a great economic impact in Egypt. These groups of plants include potatoes, tomatoes and eggplants. The new invasive pest of tomatoes, Tuta absoluta (Meyrick causes the greatest crop losses which can range from 60 to 100%. After its detection in Egypt during the last half of 2009, it spread quickly to all provinces in the country. We aiming to propose a sustainable control program for this devastating pest. In this research we tested three groups of control agents. The first was microbial and natural, the second - plant extracts and the third - chemical insecticides. Our results showed that the impact of T. absoluta can be greatly reduced by the use of sustainable control measures represented by different insecticide groups. Bioassay experiments showed that this devastating pest can be controlled with some compounds that give high mortality rates. Of these compounds, spinosad and Beauveria bassiana, microbial control agents, followed by azadirachtin, gave the best results in controlling T. absoluta. Of the chemical insecticides, lambda-cyhalotrin was the most effective, followed by lufenuron and profenofos. In conclusion we encourage farmers to use microbial and natural control measures in combating the tomato leafminer, T. absoluta, in Integrated Pest Mangement (IPM programs.

Closed-loop control with a coupling factor using an AO system

International Nuclear Information System (INIS)

Seo, Y-S; Baik, S-H; Park, S-K; Hong, S-K; Lim, C; Kim, C-J

2008-01-01

To stabilize a closed-loop control for a wavefront correction of a distorted laser beam, the instrumentation of an adaptive optics system and the closed-loop wavefront correction algorithms were investigated. We proposed a new control algorithm using a coupling factor from the zonal and the modal ideas. Compensating for an arbitrary wavefront distortion of a laser beam in the real-time, the wavefront correction speed was 5 Hz using the proposed methods of a zonal control with a coupling factor. Although the correction speed is slower in the new algorithm, the correction accuracy is more stable. The experimental results show that the proposed algorithm is appropriate for the wavefront correction of a low frequency fluctuation

Student Teachers' Knowledge about Chemical Representations

Science.gov (United States)

Taskin, Vahide; Bernholt, Sascha; Parchmann, Ilka

2017-01-01

Chemical representations serve as a communication tool not only in exchanges between scientists but also in chemistry lessons. The goals of the present study were to measure the extent of student teachers' knowledge about chemical representations, focusing on chemical formulae and structures in particular, and to explore which factors related to…

Incidence and risk factors of aplastic anemia in Latin American countries: the LATIN case-control study

Science.gov (United States)

Maluf, Eliane; Hamerschlak, Nelson; Cavalcanti, Alexandre Biasi; Júnior, Álvaro Avezum; Eluf-Neto, José; Falcão, Roberto Passetto; Lorand-Metze, Irene G.; Goldenberg, Daniel; Santana, Cézar Leite; de Oliveira Werneck Rodrigues, Daniela; da Motta Passos, Leny Nascimento; Rosenfeld, Luis Gastão Mange; Pitta, Marimilia; Loggetto, Sandra; Feitosa Ribeiro, Andreza A.; Velloso, Elvira Deolinda; Kondo, Andrea Tiemi; de Miranda Coelho, Erika Oliveira; Pintão, Maria Carolina Tostes; de Souza, Hélio Moraes; Borbolla, José Rafael; Pasquini, Ricardo

2009-01-01

Background Associations between aplastic anemia and numerous drugs, pesticides and chemicals have been reported. However, at least 50% of the etiology of aplastic anemia remains unexplained. Design and Methods This was a case-control, multicenter, multinational study, designed to identify risk factors for agranulocytosis and aplastic anemia. The cases were patients with diagnosis of aplastic anemia confirmed through biopsy or bone marrow aspiration, selected through an active search of clinical laboratories, hematology clinics and medical records. The controls did not have either aplastic anemia or chronic diseases. A total of 224 patients with aplastic anemia were included in the study, each case was paired with four controls, according to sex, age group, and hospital where the case was first seen. Information was collected on demographic data, medical history, laboratory tests, medications, and other potential risk factors prior to diagnosis. Results The incidence of aplastic anemia was 1.6 cases per million per year. Higher rates of benzene exposure (≥30 exposures per year) were associated with a greater risk of aplastic anemia (odds ratio, OR: 4.2; 95% confidence interval, CI: 1.82–9.82). Individuals exposed to chloramphenicol in the previous year had an adjusted OR for aplastic anemia of 8.7 (CI: 0.87–87.93) and those exposed to azithromycin had an adjusted OR of 11.02 (CI 1.14–108.02). Conclusions The incidence of aplastic anemia in Latin America countries is low. Although the research study centers had a high coverage of health services, the underreporting of cases of aplastic anemia in selected regions can be discussed. Frequent exposure to benzene-based products increases the risk for aplastic anemia. Few associations with specific drugs were found, and it is likely that some of these were due to chance alone. PMID:19734415

A Study of Interactions between Mixing and Chemical Reaction Using the Rate-Controlled Constrained-Equilibrium Method

Science.gov (United States)

Hadi, Fatemeh; Janbozorgi, Mohammad; Sheikhi, M. Reza H.; Metghalchi, Hameed

2016-10-01

The rate-controlled constrained-equilibrium (RCCE) method is employed to study the interactions between mixing and chemical reaction. Considering that mixing can influence the RCCE state, the key objective is to assess the accuracy and numerical performance of the method in simulations involving both reaction and mixing. The RCCE formulation includes rate equations for constraint potentials, density and temperature, which allows taking account of mixing alongside chemical reaction without splitting. The RCCE is a dimension reduction method for chemical kinetics based on thermodynamics laws. It describes the time evolution of reacting systems using a series of constrained-equilibrium states determined by RCCE constraints. The full chemical composition at each state is obtained by maximizing the entropy subject to the instantaneous values of the constraints. The RCCE is applied to a spatially homogeneous constant pressure partially stirred reactor (PaSR) involving methane combustion in oxygen. Simulations are carried out over a wide range of initial temperatures and equivalence ratios. The chemical kinetics, comprised of 29 species and 133 reaction steps, is represented by 12 RCCE constraints. The RCCE predictions are compared with those obtained by direct integration of the same kinetics, termed detailed kinetics model (DKM). The RCCE shows accurate prediction of combustion in PaSR with different mixing intensities. The method also demonstrates reduced numerical stiffness and overall computational cost compared to DKM.

Research progress on influencing factors of hospital infection and prevention and control measures

Directory of Open Access Journals (Sweden)

He Wenlong

2015-03-01

Full Text Available Hospital infections are associated with the emergence of hospitals. As the understanding of hospital infections deepen and prevention and control measures improve, hospital infections have become manageable. In recent years, affected by the increase in invasive treatment technology, antimicrobial abuse, and other factors, the control of hospital infection has encountered new problems. This paper reviews the influencing factors of hospital infections and their prevention and control measures.

Microcomputer-based systems for automatic control of sample irradiation and chemical analysis of short-lived isotopes

International Nuclear Information System (INIS)

Bourret, S.C.

1974-01-01

Two systems resulted from the need for the study of the nuclear decay of short-lived radionuclides. Automation was required for better repeatability, speed of chemical separation after irradiation and for protection from the high radiation fields of the samples. A MCS-8 computer was used as the nucleus of the automatic sample irradiation system because the control system required an extensive multiple-sequential circuit. This approach reduced the sequential problem to a computer program. The automatic chemistry control system is a mixture of a fixed and a computer-based programmable control system. The fixed control receives the irradiated liquid sample from the reactor, extracts the liquid and disposes of the used sample container. The programmable control executes the chemistry program that the user has entered through the teletype. (U.S.)

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine

International Nuclear Information System (INIS)

Gudzenko, N.; Hatch, M.; Bazyka, D.; Dyagil, I.; Reiss, R.F.; Brenner, A.; Chumak, V.; Babkina, N.; Zablotska, L.B.; Mabuchi, K.

2015-01-01

Background: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. Methods: In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. Results: After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. Conclusions: These data – the first from a working population in Ukraine – add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products. - Highlights: • A unique population – a cohort of 110,645 Chernobyl clean-up workers from Ukraine. • Followed 1986–2006 for leukemia, interviewed about non-radiation risk factors. • Petroleum exposure increased risk for non-CLL leukemias, particularly CML. • No risk factor other than radiation was found for CLL.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine

Energy Technology Data Exchange (ETDEWEB)

Gudzenko, N., E-mail: gudznat@gmail.com [National Research Center for Radiation Medicine, Kyiv (Ukraine); Hatch, M., E-mail: hatchm@mail.nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD (United States); Bazyka, D., E-mail: Bazyka@yahoo.com [National Research Center for Radiation Medicine, Kyiv (Ukraine); Dyagil, I., E-mail: leuk@ukr.net [National Research Center for Radiation Medicine, Kyiv (Ukraine); Reiss, R.F., E-mail: rfr1@columbia.edu [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY (United States); Brenner, A., E-mail: brennera@mail.nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD (United States); Chumak, V., E-mail: Chumak.vadim@gmail.com [National Research Center for Radiation Medicine, Kyiv (Ukraine); Babkina, N., E-mail: natalie.babkina@gmail.com [National Research Center for Radiation Medicine, Kyiv (Ukraine); Zablotska, L.B., E-mail: lydia.zablotska@ucsf.edu [Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, CA (United States); Mabuchi, K., E-mail: mabuchik@mail.nih.gov [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD (United States)

2015-10-15

Background: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. Methods: In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. Results: After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. Conclusions: These data – the first from a working population in Ukraine – add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products. - Highlights: • A unique population – a cohort of 110,645 Chernobyl clean-up workers from Ukraine. • Followed 1986–2006 for leukemia, interviewed about non-radiation risk factors. • Petroleum exposure increased risk for non-CLL leukemias, particularly CML. • No risk factor other than radiation was found for CLL.

Effect of an invasive ant and its chemical control on a threatened endemic Seychelles millipede.

Science.gov (United States)

Lawrence, James M; Samways, Michael J; Henwood, Jock; Kelly, Janine

2011-06-01

The impact of invasive species on island faunas can be of major local consequence, while their control is an important part of island ecosystem restoration. Among these invasive species are ants, of which some have a disruptive impact on indigenous arthropod populations. Here, we study the impact of the invasive African big-headed ant, Pheidole megacephala, on a small Seychelles island, Cousine, and assess the impact of this ant, and its chemical control, using the commercially available hydramethylnon-based bait, Siege, on the endemic keystone Seychelles giant millipede species, Sechelleptus seychellarum. We found no significant correlations in landscape-scale spatial overlap and abundance between the ant and the millipede. Furthermore, the ant did not attack healthy millipedes, but fed only on dying and dead individuals. The chemical defences of the millipede protected it from ant predation. Ingestion of the bait at standard concentration had no obvious impact on the millipede. The most significant threat to the Seychelles giant millipede in terms of P. megacephala invasion is from possible catastrophic shifts in ecosystem function through ant hemipteran mutualisms which can lead to tree mortality, resulting in alteration of the millipede's habitat.

RF control at transient beamloading for high-duty-factor linacs

Energy Technology Data Exchange (ETDEWEB)

Chernogubovsky, M.A.; Sugimoto, Masayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

1998-08-01

An effective RF control with the transient beamloading is the major issue in the operation of the high-duty-factor linacs to suppress the undesirable beam loss. The RF control method is considered to obtain the control principle and the state equation, under the analysis of electrodynamical properties of the excitation in the resonator of the linac due to the transient beamloading. The concept of the directional selective coupling is applied for the RF system to define the main characteristics and to optimize the RF control parameters. (author)

SHIFTING WEED COMPOSITIONS AND BIOMASS PRODUCTION IN SWEET CORN FIELD TREATED WITH ORGANIC COMPOSTS AND CHEMICAL WEED CONTROLS

Directory of Open Access Journals (Sweden)

Marulak Simarmata

2015-10-01

Full Text Available The objectives of the research were to study the shift of weed compositions in sweet corn field treated with organic compost and chemical weed controls and to compare the effect of treatment combinations on weed growth, weed biomass and sweet corn biomass. The research was conducted in Bengkulu, Indonesia, from April to July 2014. Results showed that the number of weed species decreased after the trials from 14 to 13. There was a shift in weed compositions because 5 species of weeds did not emerge after the trials, but 4 new species were found. Chemical weed control used a herbiside mixture of atrazine and mesotrione applied during postemergence was the most effective method to control weeds, which was observed on decreased weed emergence and weed biomass down to 22.33 and 25.00 percent of control, respectively. Subsequently, biomass production of sweet corn increased up to 195.64 percent at the same trials. Biomass of weeds and sweet corn were also affected by the organic composts. Weed biomass was inhibited by treatment of composted empty fruith bunches of oil palm, whereas significantly increased of sweet corn biomass were observed in the plots of organic manure.

Human factors inspection of current control room panel in Jose Cabrera NPP

International Nuclear Information System (INIS)

Almeida, P.; O'Hara, J.; Higgins, J.

2002-01-01

Within the process of renewal of Exploitation Permit of Jose Cabrera Nuclear Power Plant, UNION FENOSA GENERACIO, S. A. (UFG) has carried out an analysis and evaluation project regarding human factors implications of current control room panel arrangement. The project has been developed in two phases. In the first phase, leaded by EPRI and carried out by experts from SAIC, an independent review from a double viewpoint of human reliability and human factors was developed. In the second phase, a multidisciplinary team (composed by human factors, risk analysis, operation, engineering, training and instrumentation and controls experts) has developed a study on human factors implications of current panel arrangement, following the methodology pointed out in NUREG-0711. The project has been developed under the direction of Brookhaven National Laboratory (BNL), organisation that has authored the aforementioned methodology, with the participation of UFG and SOLUZIONA Ingenieria. For the development of the second study the following steps were taken: Firstly, the potential effects of panel arrangement on crew performance were identified its real evidence was analysed and the goals for the improvement of control room operation were established; following NUREG-0711. After this, several design alternatives that addressed these goals were identified and were analysed along three dimensions: human factors, risk analysis and economic costs. Finally the results of these evaluations were combined using a multi-attribute decision method to arrive at a recommended alternative as he best proposal to incorporate human factors criteria and good practices in the design of control room panels. (Author)

Endocrine disrupting chemicals in indoor and outdoor air

Science.gov (United States)

Rudel, Ruthann A.; Perovich, Laura J.

The past 50 years have seen rapid development of new building materials, furnishings, and consumer products and a corresponding explosion in new chemicals in the built environment. While exposure levels are largely undocumented, they are likely to have increased as a wider variety of chemicals came into use, people began spending more time indoors, and air exchange rates decreased to improve energy efficiency. As a result of weak regulatory requirements for chemical safety testing, only limited toxicity data are available for these chemicals. Over the past 15 years, some chemical classes commonly used in building materials, furnishings, and consumer products have been shown to be endocrine disrupting chemicals - that is they interfere with the action of endogenous hormones. These include PCBs, used in electrical equipment, caulking, paints and surface coatings; chlorinated and brominated flame retardants, used in electronics, furniture, and textiles; pesticides, used to control insects, weeds, and other pests in agriculture, lawn maintenance, and the built environment; phthalates, used in vinyl, plastics, fragrances, and other products; alkylphenols, used in detergents, pesticide formulations, and polystyrene plastics; and parabens, used to preserve products like lotions and sunscreens. This paper summarizes reported indoor and outdoor air concentrations, chemical use and sources, and toxicity data for each of these chemical classes. While industrial and transportation-related pollutants have been shown to migrate indoors from outdoor sources, it is expected that indoor sources predominate for these consumer product chemicals; and some studies have identified indoor sources as the predominant factor influencing outdoor ambient air concentrations in densely populated areas. Mechanisms of action, adverse effects, and dose-response relationships for many of these chemicals are poorly understood and no systematic screening of common chemicals for endocrine disrupting

Chemical and biological weapons

International Nuclear Information System (INIS)

Harris, E.D.

1991-01-01

This paper discusses the prospects of the multilateral negotiations aimed at achieving a complete and total ban on chemical weapons the Chemical Weapons convention (CWC). The control of the proliferation of chemical weapons is no longer just on East-West issue; it is also an issue of concern in Third World Countries, and in some of the wealthier middle eastern nations, such as Kuwait

CONTROLLING FACTORS OF POTENTIAL EVAPOTRANSPIRATION ABOVE GRASSLAND IN HUMID AND ARID AREA

Directory of Open Access Journals (Sweden)

. Yanto

2013-05-01

Full Text Available Potential evapotranspiration (PET is an importance process in water balance studies controlled by a number of meteorological factors such as temperature, wind speed, atmospheric pressure, solar radiation, vapor pressure gradient, relative humidity and biological factors such as vegetation type, canopy height and plant density that varied in time-scale and in spatial scale. Of all those variables, determining the most controlling factors of evapotranspiration in humid and arid area is of interest of this paper. Two sites representing humid and arid area i.e. Fermi Prairie site in Illinois and Audubon Research Ranch in Arizona respectively were investigated in this study.  The flux data employed in this study was acquired from Ameriflux Netwotk. Penmann-Monteith formula is employed in to estimate evapotranspiration rate in both sites. The result shows that the PET is in dependence on the considered meteorological factor such as shortwave radiation, vapor pressure, air temperature, wind speed, net radiation and vapor pressure deficit. It is also can be inferred from the analysis that PET is also strongly controlled by vegetation factors represented as stomatal resistance. Keywords: Potential evapotranspiration, Penmann-Monteith, humid, arid.

Ranking malaria risk factors to guide malaria control efforts in African highlands.

Directory of Open Access Journals (Sweden)

Natacha Protopopoff

Full Text Available INTRODUCTION: Malaria is re-emerging in most of the African highlands exposing the non immune population to deadly epidemics. A better understanding of the factors impacting transmission in the highlands is crucial to improve well targeted malaria control strategies. METHODS AND FINDINGS: A conceptual model of potential malaria risk factors in the highlands was built based on the available literature. Furthermore, the relative importance of these factors on malaria can be estimated through "classification and regression trees", an unexploited statistical method in the malaria field. This CART method was used to analyse the malaria risk factors in the Burundi highlands. The results showed that Anopheles density was the best predictor for high malaria prevalence. Then lower rainfall, no vector control, higher minimum temperature and houses near breeding sites were associated by order of importance to higher Anopheles density. CONCLUSIONS: In Burundi highlands monitoring Anopheles densities when rainfall is low may be able to predict epidemics. The conceptual model combined with the CART analysis is a decision support tool that could provide an important contribution toward the prevention and control of malaria by identifying major risk factors.

Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

International Nuclear Information System (INIS)

Pauget, B.; Gimbert, F.; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

2012-01-01

Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO 4 , EDTA, CaCl 2 , NH 4 NO 3 , NaNO 3 , free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r² adj = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r² adj = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: ► New approach to identify chemical methods able to predict metal bioavailability to snails. ► Bioavailability of cadmium, lead and zinc to snails was determined by

Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

Energy Technology Data Exchange (ETDEWEB)

Pauget, B.; Gimbert, F., E-mail: frederic.gimbert@univ-fcomte.fr; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

2012-08-01

Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO{sub 4}, EDTA, CaCl{sub 2}, NH{sub 4}NO{sub 3}, NaNO{sub 3}, free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r Superscript-Two {sub adj} = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r Superscript-Two {sub adj} = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: Black-Right-Pointing-Pointer New approach to identify chemical methods able to predict metal bioavailability

[Risk assessment and risk control for occupational exposure to chemical toxicants from an isophorone nitrile device].

Science.gov (United States)

Wang, Dejun; Fu, Xiaokuan; Kong, Fanling; Sui, Shaofeng; Jiang, Yuanyuan; Du, Yinglin; Zhou, Jingyang

2014-06-01

Risk assessment and risk control for occupational exposure to chemical toxicants were performed on an isophorone nitrile device with an annual production of 5,000 tons, based on improved Singaporean semi-quantitative risk assessment method, with consideration of actual situation in China and in the present project. With the use of engineering analysis and identification of occupational hazards in the improved Singaporean semi-quantitative risk assessment method, hazard rating (HR) and risk assessment were performed on chemical toxicants from an isophorone nitrile device with an annual production of 5,000 tons. The chemical toxicants in the isophorone nitrile device were mainly isophorone, hydrocyanic acid, methanol, phosphoric acid, sodium hydroxide, and sodium cyanide; the HR values were mild hazard (2), extreme hazard (5), mild hazard (2), mild hazard (2), moderate hazard (3), and extreme hazard (5), respectively, and the corresponding exposure rating (ER) values were 2.09, 2.72, 2.76, 1.68, 2.0, and 1.59, respectively. The risk of chemical toxicants in this project was assessed according to the formula Risk = [HR×ER](1/2). Hydrocyanic acid was determined as high risk, sodium hydroxide and sodium cyanide as medium risk, and isophorone, methanol, and phosphoric acid as low risk. Priority in handling of risks was determined by risk rating. The table of risk control measure was established for pre-assessment of occupational hazards. With risk assessment in this study, we concluded that the isophorone nitrile device with 5,000 ton annual production was a high-occupational hazard device. This device is a project of extreme occupational hazard. The improved Singaporean semi-quantitative risk assessment method is a scientific and applicable method, and is especially suitable for pre-evaluation of on-site project with no analogy.

Risk Factors For Ectopic Pregnancy : A Case Control Study

Directory of Open Access Journals (Sweden)

Deshmukh J.S

1999-01-01

Full Text Available Research question: Which are the risk factors for ectopic pregnancy . Objective: To study the strength of association between hypothesised risk factors and ectopic pregnancy. Study design: Unmatched case- control study. Setting: Government Medical College, Hospital, Nagpur. Participants: 133 cases of ectopic pregnancy and equal number of controls (non pregnant women admitted to study hospital. Study variables : Pelvic inflammatory diseases, sexually transmitted diseases, IUD use at conception , past use of IUD, prior ectopic pregnancy, OC pills use at the time of conception, past use of OC pills, induced abortion, spontaneous abortion, infertility and pelvic and abdominal surgery. Statistical analysis: Odds ratios & their 95% CI, Pearson’s chi square test, unconditional logistic regression analysis and population attributable risk proportion. Results : Use of IUD at conception, prior ectopic pregnancy , pelvic inflammatory disease, sexually transmitted diseases, infertility, OC pills use at the time of conception, past use of IUD and induced abortion were found to be significantly associated with ectopic pregnancy. Conclusion: Identification of these risk factors for etopic pregnancy shall help in early detection and appropriate management in an individual case and it may help in devising a comprehensive preventive strategy for ectopic pregnancy

On the quantification of the effects of organizational and management factors in chemical installations

International Nuclear Information System (INIS)

Papazoglou, Ioannis A.; Aneziris, Olga

1999-01-01

The quantitative effects of organizational and management factors in chemical installations are assessed through a linking of the results of a safety management audit with the basic events of a quantified risk assessment (QRA). A safety management audit establishes the relative position of the organizational and management aspects of a particular chemical installation with respect to an ideal management scheme, and for a number of failure causes and failure prevention combinations. A quantitative risk analysis including detailed system analysis offers a plant-specific decomposition of the plant-damage-state frequencies into events like hardware failures, maintenance-related failures, operation-related failures and so on. The basic events incorporated in the QRA are then categorized into classes similar to those explored by the management audit and are quantitatively linked to the audit results. Knowledge of these quantitative links would allow for the reflection of the deficiencies or strengths that might exist in the safety management system on the quantitative risk indices. A case study of an ammonia storage facility that has been audited demonstrates that the sensitivity of the risk indices to the value of the quantitative links is extremely high and that hence great care should be exercised in assessing these links

Design and Control of Chemical Grouting : Volume 3 - Engineering Practice

Science.gov (United States)

1983-04-01

Recent improvements in the engineering practice of chemical grouting have provided increased confidence in this method of ground modification. Designers can significantly improve the success of chemical grouting by defining their grouting program obj...

Neutronics and mass transport in a chemical reactor associated with controlled thermonuclear fusion reactor

International Nuclear Information System (INIS)

Dang, V.D.; Steinberg, M.; Lazareth, O.W.; Powell, J.R.

1976-05-01

The formation of ozone from oxygen and the dissociation carbon dioxide to carbon monoxide and oxygen is studied in a gamma-neutron chemical process blanket associated with a controlled thermonuclear reactor. Materials used for reactor tube wall will affect the efficiency of the energy absorption by the reactants and consequently the yield of reaction products. Three kinds of materials, aluminum, stainless steel and fiber (Al 2 O 3 )-aluminium are investigated for the tube wall material in the study

Chemical and Mechanical Weed Control Methods and Their Effects on Photosynthetic Pigments and Grain Yield of Kidney Bean

Directory of Open Access Journals (Sweden)

A.S Ghatari

2015-11-01

Full Text Available To evaluate the integrated management of weeds in red kidney bean, a split-plot experiment using randomized complete block design with three replications was conducted in 2013 in the Damavand County. In this experiment, the mechanical control treatments consisted of two levels (no cultivation and one cultivation asseigned to main plots and controlling chemical treatments consisted of six levels (non-application of herbicides, pre-emergence herbicide application of Pursuit with full dose of 1 liter per hectare, pre-emergence herbicide application of Pursuit a dose decreased 0.5 liters per hectare, post-emergence herbicide application of Pursuit dose reduced to 0.3 liters per hectare + 2 thousand citogate, post-emergence herbicide application of Pursuit with a reduced dose of 0.5 liters per hectare + 2 thousand citogate, post-emergence herbicide application of Pursuit full dose of 1 liter per hectar + 2 thousand citogate to subplots. The results showed that the effects of interaction between herbicide application and cultivation for traits of carotenoids, chlorophyll a, chlorophyll b and total chlorophyll contents, density of weeds and their dry weights were significant at 1 %, and grain yield at the 5% probability levels. The highest bean seed yield with an average of 5461.6 kg.ha-1 and lowest weed dry weight with an average of 345.9 kg.ha-1 were related to pre-emergence herbicide and cultivation with a dose of 1 liter per hectare treatment. The difference between full and reduced doses of chemical weed control was non-significant. It could be concluded that integrated mechanical and chemical weed control not only may increase seed yield but also reduce, environmental hazards.

Interaction of Physical and Chemical Processes Controlling the Environmental Fate and Transport of Lampricides Through Stream-Hyporheic Systems

Science.gov (United States)

Hixson, J.; Ward, A. S.; Schmadel, N.; McConville, M.; Remucal, C.

2016-12-01

The transport and fate of contaminants of emerging concern through the environment is complicated by the heterogeneity of natural systems and the unique reaction pathways of individual compounds. Our current evaluation of risk is often simplified to controls assumed to be homogeneous in space and time. However, we know spatial heterogeneity and time-variable reaction rates complicate predictions of environmental transport and fate, and therefore risk. These complications are the result of the interactions between the physical and chemical systems and the time-variable equilibrium that exists between the two. Compounds that interact with both systems, such as photolytic compounds, require that both components are fully understood in order to predict transport and fate. Release of photolytic compounds occurs through both unintentional releases and intentional loadings. Evaluating risks associated with unintentional releases and implementing best management practices for intentional releases requires an in-depth understanding of the sensitivity of photolytic compounds to external controls. Lampricides, such as 3-trifluoromethyl-4-nitrophenol (TFM), are broadly applied in the Great Lakes system to control the population of invasive sea lamprey. Over-dosing can yield fish kills and other detrimental impacts. Still, planning accounts for time of passage and dilution, but not the interaction of the physical and chemical systems (i.e., storage in the hyporheic zone and time-variable decay rates). In this study, we model a series of TFM applications to test the efficacy of dosing as a function of system characteristics. Overall, our results demonstrate the complexity associated with photo-sensitive compounds through stream-hyporheic systems, and highlight the need to better understand how physical and chemical systems interact to control transport and fate in the environment.

Enhancing the NCSU PULSTAR reactor control room with human factors considerations

International Nuclear Information System (INIS)

Glover, B.L.; Pupons, D.E.; Perez, P.B.

1993-01-01

The North Carolina PULSTAR research reactor was constructed to support teaching, training, and research. The training provided is not limited to academic students but encompasses plant operators, managers, engineers, designers, and supporting organizations in the nuclear industry. Our facility is under-going design changes to maximize teaching effectiveness and continued safe operation by providing current technology in the control room. The opportunity for the enhancements is a result of the generosity of neighboring utilities and the US Department of Energy instrumentation upgrade funds. Our objective, to provide a control room environment that conforms to selected industry practices, required human factors input. A human factors course, offered jointly between the industrial engineering and the psychology departments, included the PULSTAR control room enhancement as a case study

Controlling Chemical Reactions in Confined Environments: Water Dissociation in MOF-74

Directory of Open Access Journals (Sweden)

Erika M. A. Fuentes-Fernandez

2018-02-01

Full Text Available The confined porous environment of metal organic frameworks (MOFs is an attractive system for studying reaction mechanisms. Compared to flat oxide surfaces, MOFs have the key advantage that they exhibit a well-defined structure and present significantly fewer challenges in experimental characterization. As an example of an important reaction, we study here the dissociation of water—which plays a critical role in biology, chemistry, and materials science—in MOFs and show how the knowledge of the structure in this confined environment allows for an unprecedented level of understanding and control. In particular, combining in-situ infrared spectroscopy and first-principles calculations, we show that the water dissociation reaction can be selectively controlled inside Zn-MOF-74 by alcohol, through both chemical and physical interactions. Methanol is observed to speed up water dissociation by 25% to 100%, depending on the alcohol partial pressure. On the other hand, co-adsorption of isopropanol reduces the speed of the water reaction, due mostly to steric interactions. In addition, we also investigate the stability of the product state after the water dissociation has occurred and find that the presence of additional water significantly stabilizes the dissociated state. Our results show that precise control of reactions within nano-porous materials is possible, opening the way for advances in fields ranging from catalysis to electrochemistry and sensors.

Therapeutic interventions and success in risk factor control for secondary prevention of stroke.