Applied Scientific Research Research Articles

Estimation of toxicity of chemical mixtures through modeling of chemical interactions.

The Agency for Toxic Substances and Disease Registry (ATSDR), in collaboration with the Dutch Organization for Applied Scientific Research (TNO) Nutrition and Food Research Institute, is conducting studies to evaluate the role of chemical interactions in the expression of toxicity from low-level exposure to combinations of chemicals. The goal of this collaborative effort is to use a weight-of-evidence (WOE) approach to estimate joint toxicity of some simple chemical mixtures and to compare the estimations with test results from animal toxicity studies. The WOE approach uses individual chemical dose-response assessments and algorithms that incorporate various assumptions regarding potential chemical interactions. Qualitative evaluations were prepared for binary combinations of chemicals for the effect of butyl hydroxyanisole on di(2-ethylhexyl)phthalate, the effect of stannous chloride on Cd chloride (CdCl2), and the effect of CdCl2 on loperamide. Analyses of these evaluations and their comparison with the conclusions of laboratory animal experiments indicate that the WOE approach can be used to estimate qualitatively the joint toxicity of such simple mixtures. To further test the utility of the WOE approach, qualitative and semiquantitative evaluations were prepared for two chemical mixtures--one with similarly acting halogenated aliphatics (trichloroethylene, tetrachloroethylene, hexachloro-1,3-butadiene[HCBD], and 1,1,2-trichloro-3,3,3-trifluoropropene [TCTFP]) and the other with dissimilarly acting nephrotoxic components (mercuric chloride, lysinolalanine, D-limonene, and HCBD). These two sets of data were used to estimate the overall toxicities of the mixtures using the WOE algorithm for the mixture. The comparison of the results of the estimated toxicity with experimentally determined toxicity of the mixture of similarly acting nephrotoxicants demonstrated that the WOE approach correctly adjusted for the observed interactions in experimental animal studies. However, this was not true for the mixture of dissimilarly acting nephrotoxicants. This could be attributed to the fact that WOE evaluations are based on dose additivity that postulates that all chemicals in a given mixture act in the same way--by the same mechanism--and differ only in their potencies. In these cases the WOE approach evaluations, based on consideration of common mechanisms for simple chemical mixtures, can lead to better estimates of joint toxicity of chemical mixtures than the default assumption of dose additivity. The results also show that the WOE evaluations should be target-organ specific because none of the models tested could approximate the observed responses in organs other than the target organs in the laboratory animal studies.

Presidential Address, 1998] Applied scientific research: I did it my way.

Presidential Address, 1998] Applied scientific research: I did it my way.

National database of patients visiting rheumatologists in The Netherlands: the standard diagnosis register of rheumatic diseases. A report and preliminary analysis.

I most countries, little is known about the number Netherlands, patients do not have direct access to rheumatologists, but have to present with the rheumof patients who attend rheumatological out-patient clinics, or about the type, characteristics and severity atic complaints to a general practitioner (GP) first. Nearly all people are registered with a GP. The GP of their diseases, because existing registers predominantly focus on hospitalized patients. Perhaps the can decide whether or not it is necessary to refer someone, for instance to a rheumatologist, another best known example of a rheumatology register is the ARAMIS (American Rheumatism Association medical specialist or a physiotherapist. In addition to the primary focus of the register, the SDR can be used Medical Information System) database [1–4]. However, this is not a register that can be used to to select or sample cohorts of patients with specific diagnoses for clinical or epidemiological research. This study the morbidity patterns and the number of patients with particular diseases in rheumatological system for collecting data could be used in other countries to enable comparison of rheumatological practices because the data do not include all patients attending out-patient clinics. Recently, three articles practice at an international level. In this report, we first describe the set-up and were published describing morbidity patterns in paediatric rheumatology clinics in the USA [5], the UK [6 ] contents of the register. We then present the results of analyses of data from the 1993 database of the SDR and Canada [7]. This article describes morbidity patterns in rheumatology out-patient clinics in general. to give an impression of morbidity patterns in rheumatological practices in the Netherlands. In the discusUntil 1978, little was known about the attendance of rheumatological out-patient clinics in the sion, we address some issues about the strengths and weaknesses of the SDR. Netherlands, even though 95% of the patients of rheumatologists are treated at out-patient clinics. For DESCRIPTION OF THE SDR that reason, in 1978 the Rheumatic Diseases Research Committee of TNO (The Netherlands Organization of Aims Applied Scientific Research) set up the so-called The SDR was set up to provide national data on Standard Diagnosis Register of Rheumatic Diseases the morbidity of patients who visit rheumatologists. (SDR). The focus of this register is the collection of Therefore, the participants in the register are practising representative data from the participating rheumatorheumatologists. In addition to receiving aggregated logical practices, to form a national database. data, each participant is also provided with data from Data from the SDR can be used to gain insight into his or her own practice, so that he or she can compare the morbidity pattern of the ‘average’ Dutch rheumatohis or her own practice population and morbidity logical practice and into differences between practices patterns with the national data or with relevant suband trends over the years [8]. If the participation rate groups (e.g. university hospitals vs other hospitals). is high enough, estimates of the 1 yr new episode Another important goal of the SDR is to facilitate the incidence and the 1 yr consulting prevalence of the sampling or selection of patients for clinical research, various rheumatic diseases or complications at the level especially multicentre trials. of rheumatological practices can be obtained. These data are not representative for the general population, Participation rates but with such information it is possible to estimate the When the SDR started in 1978, the yearly collection proportion of patients with a particular disease, who of data was limited to rheumatological diagnoses and are referred to rheumatologists, if epidemiological data demographic information. The participation rate has from the general population are also available. In The increased substantially from 1988 onwards, when the SDR was financially supported by the Dutch Ministry of Health and the Dutch League Against Rheumatism. Submitted 9 October 1997; revised version accepted 11 In addition, the organization and the collection of December 1997. data were improved and extended. The number of Correspondence to: H. S. Miedema, Department of Public Health participating rheumatologists increased between 1983 and Prevention, TNO Prevention and Health, PO Box 2215, 2301 CE Leiden, The Netherlands. and 1994 from 32 to 85 (37 and 80%, respectively, of

HACCP approach to ensure the safety and quality of food packaging

EC Directive 93/43/EEC of 14 June 1993 on the hygiene of foodstuffs has been implemented in the Netherlands through the Food and Commodity Act (Warenwet) of 14 December 1995. This Directive requires food companies to identify steps in their activities that are critical to ensuring food safety, and to ensure that adequate safety procedures are identified, implemented, maintained and reviewed based on the principles of the Hazard Analysis Critical Control Point (HACCP) system. HACCP is a tool used to assess hazards, estimate risks and establish specific control measures that emphasize prevention and control rather than reliance on end‐product testing. Increasing public awareness of food safety, together with the introduction of this new legislation, has led producers and retailers of food to demand higher standards from their suppliers. Suppliers of raw materials, ingredients and also food packaging will be expected to bring their standards of hygiene in line with the expectations of the food industry. Food producers will need to obtain the guarantee from their suppliers that the packaging does not negatively influence their products. HACCP is a method that can also be applied to ensure the safety and other quality aspects of all kinds of food packaging materials such as films, foils, trays, cups, boxes and tubs made of paper, cardboard, polymers, metal and other materials (single use or disposable packagings as well as re‐usable and recycled packagings). At the Netherlands Organization for Applied Scientific Research (TNO), the quality and safety aspects of re‐use of food packaging, and refillable bottles in particular, have been the subject of extensive investigations in the project ‘Quality monitoring of synthetic refillable bottles’. In this paper the set‐up of the project and the Codes of Practice for refillable bottles are described. Moreover, the applicability of HACCP to food packagings and an example of a HACCP study for refillable PET bottles will be discussed.

Comparison of probit expressions for the prediction of lethality due to toxic exposure

Abstract Probit expressions are widely used in quantitative risk analysis to predict the human response to to inhalation of toxic gases. This paper presents a comparison of predicted lethal concentrations using two authoritative sources for the probit equation constants, i.e. publications of the Center for Chemical Process Safety of the American Institute of Chemical Engineers and of the Netherlands Organization of Applied Scientific Research. The comparison shows that the predicted lethal concentrations are significantly different for a number of important chemicals. The basis of the probit constants for ammonia is examined in detail. Some suggestions are made regarding further work in this area.

Curvature corrections to Reynolds stress model for computation of turbulent recirculating flows

References ^rabha, S., and Jain, A. C., On the Use of Compatibility Conditions in the Solution of Gas Paniculate Boundary Layer Equations, Applied Scientific Research, Vol. 36, No. 1, 1980, pp. 81-91. Osiptsov, A. N., Structure of the Laminar Boundary Layer of a Disperse Medium on a Flat Plate, Fluid Dynamics, Vol. 15, No. 4, 1980, pp. 512-517. Marble, F. E., of Dusty Gases, Annual Review of Fluid Mechanics, Vol. 2, No. 1, 1970, pp. 397-446. Blottner, F. G., Finite Difference Methods of Solution of the Boundary-Layer Equations, AIAA Journal, Vol. 8, No. 2, 1970, pp. 193-205. Spo, S. L., Fluid Dynamics of Multiphase Systems, Blaisdell, Waltham, MA, 1967, Chap. 8.

Reviewers of Applied Scientific Research, 1991?1992

Reviewers of Applied Scientific Research, 1991?1992

Risk Analysis of a Gas‐Processing Complex in India

ONGC's Hazira Gas-Processing Complex (HGPC) consists of facilities for receiving natural gas along with associated condensate from an off-shore field at a rate of 20 MMN M3 per day. After separating the condensate, which is processed in condensate fractionation units, the gas is processed through various steps to recover LPG and to reduce its dew point to less than 5 degrees C in order to make it suitable for transportation over long distances. The acid gas recovered during the gas-sweetening step is processed to obtain sulphur. The major products manufactured at HGPC therefore are lean sweet gas, LPG, NGL, and sulphur. The Oil and Natural Gas Commission awarded the assignment on Hazard Study and Risk Analysis of their Hazira Gas-Processing Complex (HGPC) to the Council of Scientific and Industrial Research (CSIR) in association with the Netherlands Organisation for Applied Scientific Research (TNO). The scope of this assignment covered a number of closely related and fully defined activities normally encountered in this type of work. Identification of hazards through the most appropriate methods, assigning frequency of occurrence of major unwanted incidents, quantification and assessment of probable damage to plant equipment, environment, human and animal life due to an unexpected event, and evaluation of various methods for reducing risk, together constituted the methodology for this assignment. Detailed recommendations aimed at reducing risk and enhancing reliability of plant and machinery were made. This article gives an overview of the assignment.

Adhesive joints in aluminium alloy structures

The structural bonding of aluminium components in load-bearing civil engineering applications has been the subject of an extensive research programme carried out by TNO (Dutch Organisation for Applied Scientific Research), 8 industrial companies and the Ministry of Commerce. The TNO Research input was provided by TNO-IBBC - TNO Institute for Building Materials and Structures; and TNO-KRI - Plastics and Rubber Institute of TNO. The main objective of this study was to stimulate the application of adhesive bonding in aluminium alloy structures. In ppite of many years of experience - particularly in the aircraft industry - as well as developments in adhesive technology, the application of adhesives for load-bearing structures in civil engineering has never taken hold. The research programme was divided into four parts:-state of the art experimental research on adhesive mechanical properties; theoretical and experimental research on assembly details and evaluation of results and formulation of design rules. This paper summarises the most important results.

The Pulse Physics Research Program of the Netherlands Organization for Applied Scientific Research TNO

The pulse physics program is directed toward pulsed power, electromagnetic-launch, and materials research. An overview of specific research efforts being pursued in these areas is given. Details concerning the Pulse Physics Laboratory at Delft and its equipment are described. An in-house-developed fast discharge megawatt bipolar battery and a 6.7 MJ pulsed homopolar-generator-driven repetitive electromagnetic launcher are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Applied Scientific Research and the Developing Countries : Science and Public Policy

Applied Scientific Research and the Developing Countries : Science and Public Policy

Mathematical modeling of Turbulent Reacting Plumes—II. Application to the NONO 2O 3 system

Calculations performed with the Turbulent Reacting Plume Model (TRPM) developed in Part I are compared with the experimental data of Builtjes (1981, Netherlands Organization for Applied Scientific Research, Div. of Technology for Soc., Ref. No. 81-013563) for the reaction between NO in a point source plume and ambient O 3, taking place in a wind tunnel simulating a neutral atmospheric boundary layer. The comparison shows the TRPM capable of quantitatively predicting the retardation imposed on the evolution of nonlinear plume chemistry by incomplete mixing.

From Southern Morocco to Northern Israel: A Study in the Material Culture of Shelomi, by Yedida K. Stillman. 79 pages, map, 29 photographs (11 in color). In Hebrew with English introduction. Applied Scientific Research Co., University of Haifa Ltd., Haifa1982.

From Southern Morocco to Northern Israel: A Study in the Material Culture of Shelomi, by Yedida K. Stillman. 79 pages, map, 29 photographs (11 in color). In Hebrew with English introduction. Applied Scientific Research Co., University of Haifa Ltd., Haifa1982. - Volume 19 Issue 1

The Delft airgun experiment

In April and May 1983 the Geophysics Group of the Mining Department. Technische Hogeschool Delft (Delft University of Technology), carried out a seismic reflection experiment in the North Sea in cooperation with the Netherlands Organisation for Applied Scientific Research (DGV-TNO). The experiment, which cost in excess of f200000, was sponsored by six major oil companies, three seismic contractors and DGV-TNO, who also managed the project.

Creating an Effective Applied Scientific Research Program in a Developing Country

A systematic approach to the development of an applied scientific research program to meet a developing country's future technological needs is briefly described. The essential features common to all applied science programs are discussed, and approaches to the special problems of a developing country suggested.

Applied scientific research and the developing countries

Applied scientific research and the developing countries

Recovered-sulfur: a constraint or a relief for future hydrocarbon related energy technologies?

Summary All over the world where large tonnages of recovered sulfur are being produced as a result of sweetening operations at existing and coming natural-gas-exploitation projects a first order oversupply problem has to be overcome. This problem will be the more overstressed by the probability of more sulfur being recovered as a result of world environmental legislation targeted at power-plant stack-gas emissions and by the expected growth of recovered sulfur supplied following commercialization of projects for synthetic natural gas, coal liquefaction and other alternative energy sources. For the past two years a programme has been underway of the Netherlands Organization for Applied Scientific Research in assessing sulfur related subjects with interfaces to energy, materials, pollution and implementation. Sulfur proved to be a promising composite-filler with extraordinary characteristics as far as recycling, water resistance, handling etc. is concerned. For both a near and a far future an energy technology based on sulfur related primary energy resources seems possible for the so-called underdeveloped as well as the developed countries.

Integrated Control in the Netherlands 1)

AbstractIn the Netherlands the need for an ecological approach in pest control has led to the establishment in 1958 of the Research Group on harmonious control of arthropod pests later renamed into Research Group on integrated control of arthropod pests which has several sections. This Group is part of the National Council for Agricultural Research of the Organization for Applied Scientific Research (TNO). There is a close co‐operation between many Research Institutes towards developing integrated control of which the TNO Research Group is the co‐ordinating body. The research priorities have been clearly defined and the ways leading to a practical implementation of integrated control studied.

Fire Endurance of Concrete-Protected Steel Columns

An empirical formula is developed for the pre­ diction of the endurance of concrete-protected steel columns. Fire endurance is interpreted as the time during a standard test required for the temperature of the steel core to reach I 000 F (538 CJ. In the light of numerous test results, the accuracy of the formula appears to be satis­ factory. A numerical example is included to show the application of the formula. temperature. • IN A RECENT PUBLICATION1 the authors described a numerical procedure by which the temperature history of protected steel columns can be calcu­ lated during exposure. The most important information that one can derive from such a nu­ merical study is fire endurance, i.e., the time at which structural failure of a column occurs during a standard test. As the direct cause of structural failure is the buckling of the load-bearing steel core of the col­ umn, calculations aimed at predicting time of failure in a standard exposure should normal­ ly consist of two steps: the calculation of the temperature history of the column, followed by a study of its stress-deformation history. The re­ sults of numerous tests indicate, however, that structural failure usually occurs when the average T. T. Lie is a research officer with the Fire Section, Di­ vision of Building Research, National Research Council of Canada, a gradu.ate in Engineering Physics of the Technical University of Delft. He worked as a physicist in the Organi­ zation for Applied Scientific Research. T. N.. 0., in Holl~nd from 1954 to 1967 and studied on a fellowship at the Bu.ld­ ing Research Institute in Japan during 1962. Mr. Lie is .a+ present engaged in research in the field of struc.+ural _f>re protection and has published several papers on th1s subJect and is author of a book on Fire and Buildings.

Ascocarps of Aspergillus Stromatoides, A. Niveus, and A. Flavipes

SUMMARY Previously unknown ascosporic states of Aspergillus stromatoides Raper & Fennell, A. niveus Blochwitz, and A. ftavipes (Bain. & Sart.) Thorn & Church, are described from several strains recently isolated from Thailand soils. Cleistothecia of A. stromatoides are like those of the A. cremeus group. Ascocarps of A. niveus resemble those of the A. nidulans group. The perfect state of A. ftavipes is similar to that de­ scribed for A. rehmii Zukal. Several strains of Aspergillus stromatoides Raper & Fennell, A. niveus Blochwitz, and A. flavipes (Bain. & Sart.) Thorn & Church have been isolated from Thailand soils in recent years. These strains were made available to the authors from a general survey collection of micro­ scopic fungi isolated in upland forested areas of central Thailand during a cooperative program of the Tropical Environmental Data Project, U. S. Army, and the Applied Scientific Research Corporation of Thailand. These isolates have been identified by comparison with strains derived from type or authentic material of the species to which they are assigned. They are notable in the production of perfect states, previously unde­ scribed for these species.