Outsourcing: A Growing Trend in EHS Management

This article explores the recent growth and current trends in outsourcing EHS services. More and more organizations are recognizing that outsourcing can cut costs, save time, improve staffing flexibility, and enhance the overall quality of EHS programs. © 2001 John Wiley & Sons, Inc.     

Phenes of Woody Plants: Identification,Scaling, and Use in Population Studies (An Example of Pinus sylvestrisL.)

The methods of identification and scaling of phenes of forest plants are described. The phene identification consists of five stages. Specific features of studies at each stage are shown using identification of the phenes of seed color, cone color, and seed scale structure in Scotch pine (Pinus sylvestrisL.) as examples. The method of phene scaling is based on the comparison of phene frequencies in a bog and in adjacent upland populations of pine. At the boundary between the bog and dry land, the frequencies of population-level phenes change, whereas those of superpopulation-level phenes remain unchanged.     

Estimating the Carbon Pool in the Phytomass of Larch Forests in Northern Eurasia

A data bank on larch phytomass was compiled on the basis of 60 publications describing the data obtained on 360 plots distributed over the area extending from England to Japan. These data were used for calculating conversion factors, i.e., the ratios of carbon pools in trunks, roots, skeletal branches, foliage, and understory (metric tons per hectare) to standing crop (m³/ha). The systems of recursive equations for estimating both volume-forming indices and conversion factors and combined into a second-level recursion system were calculated for 21 regions and forest formations of Northern Eurasia. The values of organic carbon pool in phytomass fractions were estimated for each region and formation.     

On Assessing Decomposition Rates of Plant Debris and Standard Cellulose Samples in Tundra Communities

Russian Journal of Ecology -     

Application of a Second-Order Kinetic Model to a Complex Melt Polymerization Reaction

A novel copolymer system has been synthesized using methyl hydroquinone diacetate (MHQDA), 1,4 naphthalene dicarboxylic acid (1,4 NDCA), and polybutylene terephthalate (PBT) using the melt polymerization technique. The optimum kinetic parameters pertinent to this system are reported in this study. A simple second-order reaction sequence summarizes catalyzed and uncatalyzed reactions between MHQDA, 1,4 NDCA, and PBT. The kinetic parameters for the copolymerization reaction were determined using a new second-order model. This technique was used to compute the moles of acetic acid generated in the polymerization process. The model was compared to that of the experimentally determined data. Close comparison (percentage error of less than 5%) was obtained between the experimental and theoretical data. The kinetic data support block copolyester formation. The thermal data also supports formation of block polymers.     

A simple model for complex waste recycling scenarios in developing economies

Future uncertainties involved in the current waste management activities in the developing nations have been addressed through determining plastic waste recovery, recycling and landfilling scenarios in two case study countries — Bangladesh and India. In order to discern and comprehend the material in-flow and out-flow of such complex successive plastics recoveries and recyclings, within the closed-loop recycling systems present in these two countries, a simple mathematical model is developed. The model is based on limited published information, on extensive fieldwork in Dhaka, Calcutta and Delhi, and on experimental data. An environmental legislative factor has been included in the model which will allow balancing of the quality of recycled products and the amount of landfilling non-recyclable plastics. The model has the potential to create and predict a sound waste database for these countries. Bangladesh has been chosen as a model developing country for this study. The mathematical model can be used in future decision making processes within the plastics recycling arena of the countries concerned to achieve an environmentally sound and cost effective waste management option.     

Eventual saturation of the climate–carbon cycle feedback studied with a conceptual model

A saturation of climate–carbon cycle feedback was found earlier in the simulations with the IAP RAS climate model of intermediate complexity. Here, this eventual saturation is interpreted by using a conceptual linearised coupled model. It is shown that this saturation is due to weak, logarithmic, dependence of the carbon dioxide radiative forcing on its atmospheric concentration. This eventual saturation leads to the non-monotonic behaviour of climate–carbon cycle parameter f   in time. If the time scale of the atmospheric CO₂${\text{CO}}_2$ build up is _tp$t_{\text{p}}$ then, starting from an initial equilibrium, f   approaches maximum in time ?_tp$?t_{\text{p}}$. Afterwards, climate–carbon cycle parameter decreases and eventually tends to unity. The time scale of the latter decrease is _t1=(1−5)_tp$t_1=(1-5)t_{\text{p}}$. A dependence of _tm$t_{\text{m}}$ and _t1$t_1$ on governing parameters of the conceptual model is studied. It is argued that an eventual saturation of the climate–carbon cycle feedback is expected to occur also in the other integrations of sufficient length with coupled climate–carbon cycle models.     

Population as an oscillating system

In this paper we present a new approach describing population dynamics based on the view of a population as an oscillating system. To develop a mathematical model of an oscillating population, we applied a third-order differential equation. Our model describes population dynamics within a parametric-temporal continuum, formed by the relative values of population growth and decrease over time. In this paper we also illustrate how our oscillative model effectively compliments the existing suite of models in population dynamics.