Loss on Ignition

Umhlatuzana rockshelter has an occupation sequence spanning the last 70,000 years. It is one of the few sites with deposits covering the Middle to Later Stone Age transition (~40,000-30,000 years BP) in southern Africa. Comprehending the site's depositional history and occupation sequence is thus important for the broader understanding of the development of Homo sapiens' behavior. The rockshelter was first excavated in the 1980s by Jonathan Kaplan. He suggested that the integrity of the late Middle Stone Age and Later Stone Age sediments was compromised by large-scale sediment movement. In 2018, we initiated a high-resolution geoarchaeological study of the site to clarify the site formation processes. Here, we present the results of the excavation and propose a revised stratigraphic division of the Pleistocene sequence based on field observations , sedimentological (particle size) analyses, and cluster analysis. The taphonomy of the site is assessed through phytolith and geo...

Climate change, a timely topic, cannot be understood solely by analyzing modern-day ecosystems. Sediment stratigraphy from tidal marshes is an important source of paleoecological data, as these ecosystems experience high rates of deposition and preserve organic material well. Although Hudson River Valley marshes have been extensively researched, work has focused on the four areas protected by the Hudson
River National Estuarine Research Reserve (HRNERR). The marshlands of Haverstraw in Rockland County are comparable to the HRNERR sites in their capacity for biodiversity, carbon sequestration, and other important ecological functions. They are, however, understudied. This study uses loss-on-ignition and macrofossil analysis in combination with X-ray fluorescence spectroscopy to construct a high-resolution
paleoenvironmental record. Biotic and geochemical zones have been identified and correlated with archaeological and historical data to assess the influence of anthropogenic activity in the area. The organic:inorganic maxima evidenced likely correspond to a preindustrial period, characterized by burning events associated with increasing populations and concentrated settlement, as well as agricultural practices. Invasive species are prevalent, but certain key native species, notably Acorus americanus (American Sweet Flag), persist today. Exponential increases in heavy metal concentrations likely result from industry in the area but have declined following cessation of this activity and introduction of unleaded gasoline. Understanding historical human impacts is vital for predicting the ramifications of future development as well as establishing protocols for conservation and restoration.

Understanding the relationship between soil fertility and species richness in mesotrophic meadows is important for the conservation of species-rich grassland and particularly for habitat creation. This relationship was investigated in surveys of two heterogeneous created meadows. Redundancy analyses of species abundance data and related soil parameters (extractable phosphorus and extractable potassium, mineral nitrogen, pH, loss-on-ignition, texture and moisture) indicated that phosphorus and potassium concentrations separately accounted for most variation in species composition at the different meadows. Contrary to expectation, low potassium was associated with low diversity, although low phosphorus was associated with high diversity. The concentration ranges in the optimal stands most closely related to species richness are: <7 mg extractable P 100 g−1 (Truog's extraction) and 10–30 mg extractable K 100 g−1. These ranges are expected to be useful in evaluating soil nutrient...

Since the publication of the paper of , loss on ignition (LOI) has been widely used as a method to estimate the amount of organic matter and carbonate mineral content (and indirectly of organic and inorganic carbon) in sediments. The relationships between LOI at 550 °C (LOI550) and organic carbon (OC) content and between LOI at 950 °C (LOI950) and inorganic carbon (IC) content are currently accepted as a standard. However, the comparison of 150 analyses of samples of diverse lithologies, collected from a single core, reveals that these relationships are affected by sediment composition (presence of clays, salts, and the variable content of organic carbon). This results in an incremental error on the estimation of carbon content from LOI values that invalidates the use of LOI values as a quantitative method for estimating carbon content. Conversely, the general trends of LOI550 and LOI950 show a good correlation with carbon content (both organic and inorganic) allowing use of LOI as a qualitative test for carbon content. Similarly, in our case, LOI at 105 °C (LOI105) is a good qualitative proxy for the trends in gypsum content.

55 pages

including patents
Wo 2013,017,232 (AVL)
US 3,39,724 by Daimler-Benz
JP 60,001,327 (Mazda)
+ the papers:
  » Effect of spark plug arrangement on flame propagation of rotary engine
  » Amelioration of combustion of hydrogen rotary engine (influence of turbulence)

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

Degradation of tropical peats is a global concern due to large Carbon emission and loss of biodiversity. The degradation of tropical peats usually starts when the government drains and clears peat forests into open peats used for food crops, oil palm and industrial timber plantations. Major properties of tropical peat forests are high in Water Contents (WC), Loss on Ignition (LOI) and Total Organic Carbon (TOC), and low in peat pH, Dry Bulk Density (DBD), and Total Nitrogen (TN). In this study, we investigated impacts of drainage and land use change on these properties. We collected peat samples from peat forests, logged over peat forest, industrial timber plantation, community agriculture, and oil palms. We used independent t-tests and oneway ANOVA to analyze mean differences of the research variables. We found that peat pH, DBD, and TN tend to increase. A significant decrease of C/N ratio in oil palm and agriculture sites importantly denotes a high rate of peat decompositions. Water contents, LOI, and TOC are relatively constants. We suggest that changes in pH, DBD, TN and atomic C/N ratio are important indicators for assessing tropical peat degradation. We infer that land use change from tropical peat forests into cleared and drained peats used for intensive timber harvesting, oil palms and industrial timber plantations in Indonesia has greatly degraded major ecological function of tropical peats as Carbon storage.

Peaty soils have an extremely high water content and a low specific gravity of solids (Gs) compared with most inorganic soils. Accurate knowledge of the Gs value allows void ratio computations for given water contents and densities. However, Gs determinations using the standard pycnometer test are time consuming and pernickety, such
that the Gs value is often predicted by way of ignition loss (N)  correlations instead. This paper presents original Gs–N data for 25 peaty soils (N = 23–86%) from the Dian-Chi Lake area, Kunming City, China, along with a data set assembled from various sources in the literature for 77 peaty clays and peats. The main research aim is to
investigate correlations between Gs, natural water content (wn) and N for the standard ignition temperature of 440°C, thereby allowing indirect Gs estimations. For the 102 peaty soils examined, the best-fit Gs–N correlation was obtained for specific gravities of the inorganic and organic solids fraction values of 2.77 and 1.35, respectively. A weaker inverse bilinear relationship was found between Gs and wn. To  overcome procedural differences between codes and for previous experimental work, it is recommended that an oven temperature of 105°C be consistently used for drying peaty soil specimens.

Road deposited sediments are polluted by various substances like organics, heavy metals and polycyclic aromatic hydrocarbons (PAHs) in site-specific contents. During rain events, a considerable amount of pollutants with storm water runoff are transport as sediment-bound contaminants to receiving watersheds. It is crucial to have a clear understanding of the particle size distribution on street surfaces and the amount of pollutants adhered to various particle sizes to optimize the removal performances of treatment systems. This paper present the results of a study carried out to determine the effect of different site-specific factors on particle size distribution on street surfaces and the amount of organic loads associated with different particle size ranges in road-deposited sediments. Particles were collected from ten different sites with a background of urban pollution and various fixed site characteristics. Particles were collected using dry vacuum cleaning technic and samples were air dried in the laboratory before sieving. Particles first were pre coarse sieved then for particle size distribution analysis subjected for dry and wet sieving with stainless steel vibratory sieving machine for size fraction 40-1000μm. For determination of loss on ignition one gram of particles for each size fraction ignited for two hours in 550°c. The results indicated that particle size range 250-1000μm has the highest abundance in collected road sediments. The results showed site-specific factors like curb height, pavement, and land use have a measurable effect on physical and chemical properties of particles. The load of nutrients in road sediments is under the direct influence of tree’s canopy coverage and surrounding land use. Site-specific factors like maximum car passage speed affect the amount of nutrients on the street surfaces considerably.

This study investigated the distribution of subfossil diatom assemblages in surficial sediments of 100 lakes along steep ecological and climatic gradients in northernmost Sweden (Abisko region, 67.07° N to 68.48° N latitude, 17.67° E to 23.52° E longitude) to develop and cross-validate transfer functions for paleoenvironmental recon- struction. Of 19 environmental variables determined for each site, 15 were included in