Grain Size Analysis

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...

The laser diffraction (LD) is one of the most widely applied grain size measurement methods. The main advantages of LD are: (1) relatively short time of single measurement, (2) low cost of analysis, (3) simplicity of sample preparation, (4) great amount of acquired numerical data. One of the less frequently obtained parameters, often provided only by application of dedicated external hardware, is so-called “elongation parameter”, “grain shape factor” or “grain shape parameter”.
Due to the inability of direct export of numerical grain shape data from the Malvern Hydro Sight camera, authors proposed own method of digitalization and recalculation
of grain shape graphs produced by the Malvern software.
Acquired sedimentological and geochemical data were analysed using statistical methods, such as correlation/regression analysis and principal components analysis (PCA).
Proposed method of data extraction and analysis of grain shape parameters may be especially useful tool during investigation of Quaternary sediments and reconstruction of environmental changes.

Grain-size analysis of beach sediments along Rosetta beach of the Nile delta coast has been carried out to reveal the depositional environment condition, energy and hydrodynamic conditions, as well as the mode of transportation along the study area. In total 56 beach samples were collected, distributed along 3 profiles parallel to the shoreline and covering the shoreline, semi-wet area, and the dry backshore area. The study showed the great sensitivity of the interrelationships of various grain size statistical parameters (mean size, sorting, skewness, and kurtosis) to the slight variations in the compositional formula of the sediment mixture. Distribution of the textural parameters revealed the dominance of unimodal pure sand sediments, mainly Nile sand sources. The fluctuation between moderately well-sorted to well-sorted sediments and from coarse skewed to fine skewed under leptokurtic to platykurtic nature was distinguished at different localities and relevant environmental implications. Different discrimination tools as bivariate cross plot of grain size parameters, Linear Discrimination Functions (LDF), skewness and kurtosis relationship as a non-dimensional  expression of sediment/energy simulation, Energy Process diagram, and mode of transportation (C-M diagram), indicates the marine signature followed the riverine input as a function of the sediments locality. Depositional processes were mainly hydraulically controlled through active energy processes of the marine environment. The fluvial nature of sediment demonstrated the graded suspension and saltation modes as the prime factors for transportation, influenced by marine and turbidity environment actions, within a shallow agitated marine environment.

In combination with the desiccation of the Aral Sea and the formation of the Aral Kum, the dry sea bed became a new source for dust and sand storms. Due to the highly continental climate and the effects of the global climate change in the region, increasing air pressure differences lead to an increasing frequency of high intensity wind events. The resulting aeolian dust movements can be tracked and split into short and long distance transfers using remote sensing approaches, but hard data about the spatial and temporal distribution of the dust deposition requires excessive ground research and thus is scarce. Therefore, we have analyzed the passive dust deposition data from 23 meteorological stations and assessed the spatial and temporal transfer patterns within several transects from the banks of the former Aral Sea in eastern and southern directions covering parts of Kazakhstan, Uzbekistan and Turkmenistan. Dust was collected on a monthly base as well as during specific dust storm events between 2003 and 2012 in the framework of three research projects for both long-term and event based deposition data. Dust transfer in southern direction was the most important trajectory and the newly formed Aral Kum proved to be an important source region for aeolian dust (besides the natural deserts Kyzyl Kum and Kara Kum). Stations close to these source regions frequently showed deposition rates exceeding international thresholds, resulting in possible negative effects on human and livestock health while the mineralogical and chemical composition of the deposited material influences the arable land in this arid region. This presentation will summarize the most important findings from the three research projects and discuss measures to reduce the wind erosion in the Aral Kum.

L’objectif de notre étude est un apport quantitatif de données sédimentaires sur des échelles spatio-temporelles variables pour une meilleure compréhension de la dynamique des plages microtidales Méditerranéennes en climat semi-aride à tempéré. Nous adoptons une approche morphodynamique associée à une étude pluridisciplinaire pour mesurer l’état de vulnérabilité de la plage selon son indicateur d’évolution : la ligne de côte.

FOR CITATIONS:
Salem, Hilmi S. (2001). Application of the Kozeny-Carman Equation to
Permeability Determination for a Glacial Outwash Aquifer, Using Grain-size Analysis, Energy Sources, 23:5, 461-473,
DOI: 10.1080/009083101300058480
To link to this article: http://dx.doi.org/10.1080/009083101300058480

ABSTRACT:
Permeability (hydraulic conductivity) is a measure of the ability of a porous medium to convey a single liquid or multiphase liquids through its body under a certain hydraulic gradient. In this study, the permeability was determined for the grain-size fractions and the layers of a glacial outwash aquifer and its aeration zone (northern Germany) using grain-size analysis and the Kozeny-Carman equation. The aquifer and the aeration zone are composed of unconsolidated sediments characterized by lateral and vertical heterogeneities. The sediments consist, primarily, of silts, sands and gravels, with a majority of sands and a variety of grain sizes. The permeability of the aquifer and the aeration zone ranges from 2.85 X 10-4  to 4.60 X 10-1 m/s, corresponding to the grain-size fractions, and from 4.02 X 10-6 to 3.35 X 10-2 m/s, corresponding to the layers. These ranges of permeability agree well with those obtained experimentally from pump tests and laboratory measurements. Several
empirical equations correlating between various parameters, with coefficients of correlation ranging from 0.65 to 1.0, were obtained.

Keywords: glacial aquifers, grain-size distribution, Kozeny-Carman equation, permeability, porosity, specic surface area.

Two plain carbon steels with varying manganese content (0.87 wt pct and 1.63 wt pct) were refined to approximately 1 μm by large strain warm deformation and subsequently subjected to intercritical annealing to produce an ultrafine grained ferrite/martensite dual-phase steel. The influence of the Mn content on microstructure evolution is studied by scanning electron microscopy (SEM).

То the methods and instruments known till now to make the grain-size analysis of pelitic sediments we add the Sedimentation Cylinder. This ultimate method, whose features have been described in a previous paper, is here related to the Andreasen Pipette Method through many series of analyses on many silty and clayey samples, in order to visualize as better as possible the possibilities and the limits of the method in question compared with others a long time experienced.
The results reached by the two methods put in comparison show the almost perfect repeatibility of the trials if these ones are made with a certain quantity of material oscillating within defined limits.
The experimental data reached suggest the quantity of material employable in the grain-size analyses in accordance with the request exactness in order to not to be prejudicial to the repeatibility of the trials and the calculus of the effective composition percentage of the frequency curves.
The paper is sustained by a physical-mathematical analysis describing the particles trajectory during the drawing and the place of the points containing the volume occupied by all the particles taken away at each drawing.

Here we present the first results provided from the geo-archaeological characterisation of the quartzites from the site of Ravensberg-Troisdorf. This location is an open-air site situated in the village of Troisdorf, in the North Rhine-Westfalia. The site was excavated in one campaign during the summer of 2015 and preliminary techno-typological results point that this site was used as workshop of quartzite by Middle Palaeolithic societies.
The geo-archaeological analysis performance here only includes the characterisation and identification of a sample of the complete assemblage. This research constitutes a descriptive analysis of eleven artefacts of quartzite sampled from the complete collection. These items of rocks were prepared for thin section analysis and X-Ray Fluorescence to understand the different types of quartzites potentially exploited at the site. These protocols have help us to understand their textures, grain size and morphological distribution, mineral characterisation and geo-chemical composition. Additionally, these artefacts and another 49 items were described under binocular microscopy to guide the procedures of following research.
We have described two different types of quartzite, according to the methodology recently proposed by our team (Prieto, 2018, Prieto, et al., 2019). These types are Clastic and Cemented quartz-arenite (CC) and Syntaxially Overgrown Orthoquartzite (OO). Moreover, two clear varieties or facies were distinguish based on the composition of the cement and matrix, the CC type with clayey matrix (CC_CM) and the CC type with microcrystalline quartz (CC_MQC).
The analysis performed in the site of Ravensberg concludes that the properties of the CC_MQC variety make it optimal for knapping and use. Then, its massive exploitation could be the main reason for human activity in this site. We propose that use and acquisition of the OO type would be secondary and derived from the main product, the CC_MQC type. The CC_CM variety could not be used for knapping due to its friable properties. Then, its usefulness is reduced and it was probably considered a waste product.
This research constitutes the first step to understand catchment, management, and distribution of quartzite in the Rin Valley but also the foundation stone for the post-doctoral research of the first author.

Austenite formation, which originated from a fined-grained ferrite plus carbide microstructure, was observed during tensile testing at
973 K (60 K below Ae1, the equilibrium austenite–pearlite transformation temperature). Scanning electron microscopy, electron
backscatter diffraction and atom probe tomography results reveal the mechanism of austenitic transformation below Ae1. The initial
fine-grained microstructure, in combination with the warm deformation process, determines the occurrence of strain-induced austenite formation below Ae1. The initial fine-grained microstructure essentially contains a higher dislocation density to facilitate the formation of Cottrell atmospheres and a larger area fraction of ferrite/carbide interfaces which serve as austenite nucleation sites. The warm deformation promotes the Ostwald ripening process and the increase in dislocation density, and hence promotes the accumulation of local high carbon concentrations in the form of Cottrell atmospheres to reach a sufficiently high thermodynamic driving force for austenite nucleation. The critical carbon concentration required for the nucleation of austenite was calculated using classical nucleation theory, which correlated well with the experimental observations.

Grain size statistical parameters studies were carried out for the sediments along Karaikal to Nagore stretch of the beach. The sediments are found to be mainly medium to coarse grained, moderately sorted, fine skewed to coarse skewed and leptokurtic to me okurtic in nature. Based on the eM pattern the sediment are concentrated in the environment of rolling and suspension. These textural parameters have been further examined to understand the hydrodynamics of the depositional environment.

The samples of AISI 1018 Low carbon steel were heated to austenite zone then cooled in different mediums with different cooling rates. Mechanical tests show increase in hardness, yield strength, tensile strength, modulus of elasticity, and yield/tensile ratio as cooling rate is increase. Ductility has inverse proportionality to cooling rate. The resulting microstructures show decreasing in grains sizes accompanying to cooling rate increase. The relations between mechanical properties and grains size are opposites of relations between mechanical properties with cooling rates. Hardness, yield strength, tensile strength, modulus of elasticity, and yield/tensile ratio increase as grains size decreases, while ductility decreases.

Yapılan tez çalışmasında, 200C ve 250C alttaş sıcaklıklarında üretilmiş Si/Bi-Te tabanlı termoelektrik ince filmlerinin topografik ve elektriksel özelliklerinin incelenmesi amaçlanmaktadır. Malzemeler, Si alttaş üzerine kompozisyonel hedef kullanılarak aynı sürede fakat 200C ve 250C alttaş sıcaklıklarında DC manyetik saçtırıcı ince film cihazında üretilmiştir. Özellikle son yıllarda, termoelektrik malzemelerin üzerinde nanomühendislik uygulamaları(ince filmler, nanoparçacık katkılanmaları, katmanlı ara yüzey yapılar vb.)
termoelektrik malzemelerin özelliklerinin büyük ölçüde arttırılmasına olanak sağlamıştır. Termoelektrik ince filmlerde, güç faktörü 𝑆^2 * 𝜎(S: Seebeck katsayısı, 𝜎: iletkenlik) ve kalite faktörü 𝑍=𝑆^2 * 𝜎 / 𝜅 (𝜅: ısısal iletkenlik) olduğundan dolayı elektriksel iletkenlik ve ısısal iletkenlik çok büyük önem arz etmektedir.Termoelektrik malzemelerde, elektriksel iletkenlik ve özellikle ısısal iletkenlik, topografik özelliklerle ilişkilidir. Malzemenin tanecik sınırlarının ve yüzey pürüzlülüğün değişimi, elektriksel ve ısısal iletkenlikte köklü değişimlere sebebiyet verebilmektedir. Üretilen ince filmler, nano yapıda oldukları için tanecik sınırları optik mikroskoplarla gözlenememektedir. Ayrıca üretilen ince filmlerin, farklı malzemelerle yapılabilecek ara yüzeylerle etkileşimlerini anlayabilmek için yüzey potansiyeli ölçümüne ihtiyaç duyulmaktadır. Üretilen ince filmlerin topografik ölçümleri yarı-temaslı ölçüm modunda 75kHz salınım frekansında, yansıtıcı yüzeyi alüminyum temas yüzeyi platinyum kaplı olan uç ile yapılmıştır. 200C alttaş sıcaklıklı üretilmiş olan filmde farklı bölgelerden (5x5μm) ve (20x20μm)’lik topografik görüntüler alınmıştır. 250C alttaş sıcaklıklı üretilmiş olan filmde farklı bölgelerden (5x5μm)’lik topografik görüntüler alınmıştır. Elektriksel ölçümler, metal bir kablo ile örnek yüzeyinden gümüş pasta ile kontak alınarak yapılmıştır. 200C alttaş sıcaklıklı üretilmiş olan filmde farklı bölgelerden (5x5μm) ve (20x20μm)’lik yüzey potansiyeli görüntüleri alınmıştır. 250C alttaş sıcaklıklı üretilmiş olan filmde farklı bölgelerden (5x5μm)’lik yüzey potansiyeli görüntüleri alınmıştır. Alınan ölçümler sonucunda, 200C alttaş sıcaklıklı üretilmiş olan filmde (5x5μm)’lik alanda tanecik büyüklüğü 2.237𝜇𝑚2 ve (20x20μm)’lik alanda 3.08𝜇𝑚2 olarak bulunmuştur. 250C alttaş sıcaklıklı üretilmiş olan filmde (5x5μm)’lik alanda tanecik büyüklüğü 0.306𝜇𝑚2 ve (5x5μm)’lik alanda 0312𝜇𝑚2 olarak bulunmuştur.

A control scheme for crystal size distribution (CSD) in a batch crystallizer, based on indirect measurement of fines suspension density and manipulation of fines dissolving rate, is proposed and implemented on a 27 L laboratory batch cooling crystallizer using the potash alum-water system. The measured variable was a temperature difference related to the fines suspension density detected by a new fines sampling/suspension density measuring device proposed by Rohani and Paine (1987). Servo-control of the fines suspension density was achieved using a conventional PI control mode. Two different cooling policies, namely, linear cooling and isothermal operation were examined and improvement in the final CSD was observed in both cases. The weight-mean crystal size and the coefficient of variation of the end product showed a maximum improvement (larger mean size and smaller coefficient of variation) of 80% and 31% over the uncontrolled experiments, respectively. The weight fraction of fines (smaller than 150 μm) in the end product was decreased by a maximum of 99% over the uncontrolled run. Higher overall rates of fines dissolution led to a more uniform product with a larger weight-mean crystal size at the expense of a small reduction in the rate of solids make.Un schéma de contrôle de la distribution de taille des cristaux dans un cristalliseur discontinu, basé sur la mesure indirecte de la densité de suspension des fines et la manipulation du taux de dissolution des fines, est proposé et utilisé sur un cristalliseur à refroidissement discontinu de laboratoire d'une capacité de 27 L avec un système alun de potasse-eau. La variable mesurée est une différence de température reliée à la densité de suspension des fines détectée par un nouveau dispositif de mesure d'échantillons de fines et de densité de suspension proposé par Rohani et Paine (1987). On a effectué la servorégulation de la densité de suspension des fines en utilisant un mode de contrôle PI classique. Deux procédures de refroidissement différentes ont été étudiées, à savoir le refroidissement linéaire et le fonctionnement isotherme, et on a observé une amélioration de la distribution finale de taille des cristaux dans les deux cas. La taille des cristaux de poids moyen et le coefficient de variation du produit final montrent une amélioration maximale (taille moyenne plus grande et coefficient de variation plus petit) de 80 et 31% pour les expériences non régulées, respectivement. La fraction de poids des fines (inférieure à 150 μm) dans le produit final est réduite jusqu'à 99% lors du cycle non régulé. Des vitesses globales supérieures de dissolution des fines donnent un produit plus uniforme avec une taille des cristaux de poids moyen plus grande au détriment d'une légère réduction de la vitesse de formation des solides.

In this contribution grain size analyses of various terrestrial soils and sediments from Jordan are compared, which are characterized by different contents of primary and secondary calcium carbonates. An intermethod comparison of pipette analysis according to Köhn, Sedigraph, and laser diffraction confirms reports
from the literature that laser diffraction is not directly comparable and should not be used. Sedigraph is
possibly the most precise method, comparable to pipette analysis, and recommended due to several advantages. Particle analyses with and without removal of CaCO
3
and comparison with BET specific surfaces
indicate limited coagulating effects of secondary carbonates, which apparently affect mainly clay subfractions. As it seems both primary and secondary carbonates are characterized by small specific surfaces. In
one sample with high share of active calcium carbonate, pre-treatment with HCl had the unexpected effect
of reduced clay contents since CaCO
3
was largely present in this fraction. These secondary carbonates occluded water and apparently formed when water-saturated sediments dried out. In most other samples, distortions due to diminished sand and silt contents could be observed. Although diluted acid seemed to have
slightly less distorting effects, it also removed all calcite grains from the sand fraction. Therefore removal of
CaCO3
is not recommended for particle size analysis of calcareous terrestrial soil and sediment samples.

The distribution of grain size parameters along 11 km stretch of the beach sediments between Karikal and Nagore, reveals that the mean grain size exhibits a marked decreasing trend on either side of the mouth of the Tirumalairajanar River which flow from west to east. The sediments are mainly of medium to coarse grained, moderately sorted, near-symmetrical skewed to fine skewed and leptokurtic to mesokurtic in nature. Interrelationship of various parameters shows bimodal nature of sediments having dominance of medium to coarse sand. The major part of the sediment fall in a coarse to fine grained category (sand and silt). Based on the CM (Coarser one percentile value in micron) pattern, the sediment fall in rolling and suspension field. These factors includes the sediments discharged from the river mixes with offshore sediments and with the sediments eroded from a source rock. The effect of wave sorting, and the northward drifting of sediments by littoral current are understandable. Results indicate that the Tirumalairajanar River is the most important source for modern sediments in the study area. The agitation by waves is an important sorting mechanism in the study area, and the net sediment transport in the study area is northward. The findings are based on the grain sizes and also corroborated by short- term observations of the beach sediment dynamics and transport during the monsoon and summer seasons between Karaikal and Nagore region.

Hydraulic conductivities associated with measurement scale of the order of 10–1 m and collected during an extensive field campaign near Tübingen, Germany, are analyzed. Estimates are provided at coinciding locations in the system using: (1) the empirical Kozeny-Carman formulation, providing conductivity values, K GS, based on particle-size distribution, and (2) borehole impeller-type flowmeter tests, which infer conductivity, K FM, from measurements of vertical flows within a borehole. Correlation between the two sets of estimates is virtually absent. However, statistics of the natural logarithm of K GS and K FM at the site are similar in terms of mean values (averages of ln K GS being slightly smaller) and differ in terms of variogram ranges and sample variances. This is consistent with the fact that the two types of estimates can be associated with different (albeit comparable) measurement (support) scales. It also matches published results on interpretations of variability of geostatistical descriptors of hydraulic parameters on multiple observation scales. The analysis strengthens the idea that hydraulic conductivity values and associated key geostatistical descriptors inferred from different methodologies and at similar observation scales (of the order of tens of cm) are not readily comparable and should not be embedded blindly into a flow (and eventually transport) prediction model. Des conductivités hydrauliques associées à des échelles de mesure de l’ordre de 10–1 m et acquises pendant une vaste campagne près de Tübingen, Allemagne, sont analysées. Les valeurs sur site sont fournies par : (1) la formule empirique de Kozeny-Carman qui donne une valeur de conductivité K GS basée sur la distribution granulométrique (2) des tests de débitmétrie micro moulinet, qui donnent la conductivité K FM par mesure de débit vertical. Une corrélation entre les deux séries d’estimations est pratiquement exclue. Cependant, les distributions statistiques des logarithmes népériens de K GS et K FM sont comparables en termes de valeurs moyennes (les moyennes de ln K GS étant légèrement plus faibles) et diffèrent en termes d’écarts du variogramme et de la variance. Ceci est cohérent avec le fait que deux types d’estimations peuvent être associés à différentes (bien que comparables) échelles de mesure (support). Ceci correspond aussi aux résultats publiés sur l’interprétation de la variabilité des descripteurs géostatistiques des paramètres hydrauliques sur des échelles d’observation multiples. L’analyse conforte l’idée selon laquelle les valeurs de conductivité hydraulique et les principaux descripteurs géostatistiques associés, déduits de différentes méthodologies et à des échelles d’observation similaires (de l’ordre de la dizaine de cm) ne sont pas directement comparables et ne devraient pas être insérées aveuglément dans un modèle de prévision d’écoulement (et finalement de transport). Se analizaron las conductividades hidráulicas asociadas con escalas de medidas del orden de 10–1 m y recolectadas durante una extensiva campaña de campo cerca de Tübingen, Alemania. Las estimaciones son provistas en localidades coincidentes en el sistema usando: (1) la formulación empírica de Kozeny-Carman, que provee valores de conductividad, K GS, basados en la distribución del tamaño de partículas, y (2) pruebas en pozos con un medidor de flujo con impulsor, lo cuales infieren la conductividad, K FM, a partir de mediciones de flujos verticales dentro del pozo. La correlación entre los dos conjuntos de estimaciones está de hecho ausente. Sin embargo, la estadística de los logaritmos naturales de K GS y K FM en los sitios son similares en términos de los valores medios (siendo los promedios del ln K GS ligeramente menores) y difiere en términos de los intervalos del variograma y de las varianzas de la muestra. Esto es consistente con el hecho que los dos tipos de estimaciones pueden estar asociados con diferentes (aunque comparables) escalas de medidas (de apoyo). También coincide con resultados publicados en la interpretación de la variabilidad de los descriptores geoestadísticos de los parámetros hidráulicos en múltiples escalas de observación. Los análisis refuerzan la idea que los valores de conductividad hidráulica y los asociados descriptores geoestadísticos claves inferidos a partir de diferentes metodologías y en las escalas de observación similar (del orden de decenas de cm) no son apropiadamente comparables y no deben ser incorporados a ciegas en un modelo de predicción de flujo (o finalmente de transporte). Analisam-se as condutividades hidráulicas associadas à escala de medição da ordem de 10–1 m de amostras recolhidas durante uma extensa campanha de campo perto de Tübingen, na Alemanha. Há estimativas fornecidas para locais coincidentes no sistema utilizando: (1) a fórmula empírica de Kozeny-Carman, fornecendo valores de condutividade, K GS, baseados na distribuição do tamanho de partículas, e (2) testes do tipo medidor de fluxo, que inferem a condutividade, K FM, a partir de medições de fluxos verticais dentro de um furo. Verificou-se que a correlação entre os dois tipos de estimativas é praticamente nula. Contudo, as estatísticas do logaritmo natural de K GS e de K FM no local são semelhantes em termos de valores médios (as médias do ln K GS sendo ligeiramente menores) e diferem em termos de escalas de variogramas e variâncias da amostra. Isto é consistente com o facto de que os dois tipos de estimativas podem estar associados a diferentes (embora comparáveis) escalas de medidas. Coincide, também, com os resultados publicados sobre interpretações de variabilidade de descritores geoestatísticos de parâmetros hidráulicos em múltiplas escalas de observação. A análise reforça a ideia de que os valores de condutividade hidráulica e os associados descritores geoestatísticos chave, inferidos a partir de diferentes metodologias, e a escalas de observação similares (da ordem de dezenas de centímetros), não são facilmente comparáveis e não devem ser incorporados às cegas num modelo de previsão de escoamento (e eventualmente de transporte).