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The purpose of this work is to present a convenient design approach for metal hydride reactors that meet the specific requirements for hydrogen storage. Three methods from the literature, the time scale, the acceptable envelope, and the reaction front, are used to estimate the maximum thickness of the bed allowing for sufficient heat transfer. Further heat transfer calculations are performed within the framework of standardized heat exchanger via the homemade design software, to generate the complete geometry and dimensions of the reactor. LaNi5 material packed in tubular units based on conventional shell-and-tube heat exchanger is selected for analysis for an expected charging time of 500 s, 1000 s, and 1500 s. Apparently, the smaller the expected charging time, the smaller the bed thickness and hence the diameter of the tubular units. After comparison, the method of reaction front was adopted to output standard tube diameters and calculate the weight of the reactor. Significant weight differences were found to result from the varying wall thickness and number of tubes. In general, the shorter the expected charging time, the more tubular units with a small diameter will be built and the heavier the reactor. Fluent 2022 R2 was used to solve the reactor model with a tube diameter of 50 mm supposed to fulfill a charging time of 1500 s. The simulation results revealed that the reaction fraction reaches its maximum and the hydrogen storage process is completed at 500 s. However, because the calculation is conducted on meeting the heat exchange requirements, the average temperature of the bed layer is close to the initial temperature of 290 K and stops changing at 1500 s. The applicability of the method to the design of metal hydride reactors is thus confirmed by the temperature and reaction fraction judgment criteria. [ABSTRACT FROM AUTHOR]

This research was conducted to evaluate the effect of thickness of floating beds on the growth and yield of okra, Indian spinach, cucumber and red amaranth, from 2013 to 2014, at Gopalganj district in Bangladesh. The single-factor experiment was conducted as a Randomized Complete Block Design (RCBD) with three replications. There were three treatments viz. 1.5 m, 2.0 m and 2.5 m thickness of floating bed, the raw material of which was solely comprised of water hyacinth biomass. The thickness of the floating bed was reduced each month due to a gradual decomposition of water hyacinth, and as the rotten material fell into the water and soil. The rate at which the floating bed became thinner accelerated through time. For okra, the maximum plant height (150.67 and 151.77 cm, respectively) was found in response to the 2.5 m thick bed which was significantly similar to the 2.0 m thick bed in both growing seasons. Bed thickness of 2.5 m led to more branches (6.67 and 6.67, respectively), leaves (47.00 and 49.67, respectively), fruits (25.00 and 26.00, respectively), fruit length (14.56 cm and 14.02 cm, respectively), fruit diameter (6.29 cm and 6.08 cm, respectively) and yield (7.99 and 8.09 t ha-1, respectively). Minimum values were observed in response to the 1.5 m thick bed in both years. A similar trend was also observed in the case of other three corps, i.e. Indian spinach, Cucumber and Red amaranth, regarding their growth and yield, as a function of bed thickness. From an economic viewpoint, the 2.0-meter thick bed was found suitable for the production of the said crops. [ABSTRACT FROM AUTHOR]

The purpose of this work is to present a convenient design approach for metal hydride reactors that meet the specific requirements for hydrogen storage. Three methods from the literature, the time scale, the acceptable envelope, and the reaction front, are used to estimate the maximum thickness of the bed allowing for sufficient heat transfer. Further heat transfer calculations are performed within the framework of standardized heat exchanger via the homemade design software, to generate the complete geometry and dimensions of the reactor. LaNi5 material packed in tubular units based on conventional shell-and-tube heat exchanger is selected for analysis for an expected charging time of 500 s, 1000 s, and 1500 s. Apparently, the smaller the expected charging time, the smaller the bed thickness and hence the diameter of the tubular units. After comparison, the method of reaction front was adopted to output standard tube diameters and calculate the weight of the reactor. Significant weight differences were found to result from the varying wall thickness and number of tubes. In general, the shorter the expected charging time, the more tubular units with a small diameter will be built and the heavier the reactor. Fluent 2022 R2 was used to solve the reactor model with a tube diameter of 50 mm supposed to fulfill a charging time of 1500 s. The simulation results revealed that the reaction fraction reaches its maximum and the hydrogen storage process is completed at 500 s. However, because the calculation is conducted on meeting the heat exchange requirements, the average temperature of the bed layer is close to the initial temperature of 290 K and stops changing at 1500 s. The applicability of the method to the design of metal hydride reactors is thus confirmed by the temperature and reaction fraction judgment criteria.

Abstract Submarine fan deposits are volumetrically the largest sediment accumulations on Earth and host significant hydrocarbon reserves. Extensive research has documented the bed‐scale architecture of high sand‐to‐mud ratio, proximal and axial environments, which can have bed thicknesses of several metres; however, less well‐understood are thin‐bedded turbidites, which are typically lower N:G and deposited in more distal environments. Conceptual models assume that lobe‐fringe‐to‐basin plain environments consist of tabular, sheet‐like beds that extend out continuously and predictably over long distances—up to several kilometres. Extensive lateral continuity, however, is not necessarily reflected in ancient outcrop analogues. This study seeks to apply a quantitative approach to the characterisation of thin‐bedded turbidites to assess the impact of multi‐scale heterogeneity on reservoir predictability. The sea‐cliff outcrop exposures of the Upper Cretaceous Point Loma Formation in San Diego, California, exhibit a wide range of bed thicknesses and stratigraphic architecture, which have been used to interpret an off‐axis‐to‐fringe depositional environment. The study area spans 700 m of laterally continuous outcrop, across which 10 correlated stratigraphic sections are used to quantify changes in metrics such as bed thickness, N:G, lithofacies proportions, etc. Results of this study demonstrate that thin sand beds experience both lateral facies changes and rapid thickness changes more frequently than conceptual models would predict. A single measure of lateral heterogeneity does not reflect the true architecture of sandstone beds, and significant information is lost when beds are correlated over ten to hundreds of metres. Sands are commonly deposited in irregular, ‘finger‐like’, planform geometries, which compounds at the lobe element scale and influences lateral lithofacies predictability. This study of the Point Loma Formation offers high‐resolution bed‐to‐element scale data, which may be used as inputs for reservoir models and horizontal facies predictions in both conventional and unconventional hydrocarbon reservoirs.

Electrodeionization (EDI) is a separation method that combines electrodialysis and ion-exchange. The continual electrical regeneration of the ion-exchange resin is the main advantage of this resulting hybrid process. The purpose of this study is to see how the inter-membrane spacing (resin bed thickness) affects EDI performance. For this purpose, resin beds thicknesses of 2, 4 and 6 mm were tested by varying operating conditions and the efficiency of the process was expressed in terms of mass transfer flux (J), current efficiency (Ce), removal efficiency (R), power consumption (P) and by the comparison of I-V curves. Our research indicated that the choice of thickness depends mainly on the electrical and hydrodynamic conditions used. Furthermore, an impressive empirical equation describing EDI efficiency as a function of flow rate and cell thickness was established. [ABSTRACT FROM AUTHOR]

Submarine fan deposits are volumetrically the largest sediment accumulations on Earth and host significant hydrocarbon reserves. Extensive research has documented the bed‐scale architecture of high sand‐to‐mud ratio, proximal and axial environments, which can have bed thicknesses of several metres; however, less well‐understood are thin‐bedded turbidites, which are typically lower N:G and deposited in more distal environments. Conceptual models assume that lobe‐fringe‐to‐basin plain environments consist of tabular, sheet‐like beds that extend out continuously and predictably over long distances—up to several kilometres. Extensive lateral continuity, however, is not necessarily reflected in ancient outcrop analogues. This study seeks to apply a quantitative approach to the characterisation of thin‐bedded turbidites to assess the impact of multi‐scale heterogeneity on reservoir predictability. The sea‐cliff outcrop exposures of the Upper Cretaceous Point Loma Formation in San Diego, California, exhibit a wide range of bed thicknesses and stratigraphic architecture, which have been used to interpret an off‐axis‐to‐fringe depositional environment. The study area spans 700 m of laterally continuous outcrop, across which 10 correlated stratigraphic sections are used to quantify changes in metrics such as bed thickness, N:G, lithofacies proportions, etc. Results of this study demonstrate that thin sand beds experience both lateral facies changes and rapid thickness changes more frequently than conceptual models would predict. A single measure of lateral heterogeneity does not reflect the true architecture of sandstone beds, and significant information is lost when beds are correlated over ten to hundreds of metres. Sands are commonly deposited in irregular, 'finger‐like', planform geometries, which compounds at the lobe element scale and influences lateral lithofacies predictability. This study of the Point Loma Formation offers high‐resolution bed‐to‐element scale data, which may be used as inputs for reservoir models and horizontal facies predictions in both conventional and unconventional hydrocarbon reservoirs. [ABSTRACT FROM AUTHOR]

Current knowledge of submarine fan deposits has historically relied heavily on qualitative field and subsurface observations and interpretations, but recent studies using statistical analyses have enhanced the understanding of submarine fan sub‐environments, including the degree of confinement, stratigraphic patterns and potential control factors. The purpose of this study is to improve the quantitative understanding of synorogenic submarine fan deposition at foreland basin settings with a statistical approach. A suite of statistical methods is integrated and developed (Hurst Statistics/rescaled range analysis, bed thickness frequency distribution analysis, Markov Chains and time‐series analysis), and applied to the well‐understood Pennsylvanian lower Atoka submarine fan system in the Ouachita Mountains, United States, for this purpose. The results of the Hurst Statistics and bed thickness analyses corroborate qualitative interpretations that: (i) the lower Atoka is lobe‐dominated; and (ii) the south‐eastern (wedge top) portion of the system is more strongly confined than the northern (foredeep) portion. The Markov Chains and time‐series analyses reveal the prevalence (56% of the measured sections) of stratigraphic orderliness and cyclicity; these results are used to discuss potential control signals, which are otherwise difficult to distinguish, on the turbidite sandstone recurrence cycles. The results of this study demonstrate that these integrated statistical methods can be utilized to quantify depositional interpretations and extract hidden information using outcrops with limited exposures. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the kinetic characteristics of the high‐density polyethylene (HDPE) waste pyrolysis process based on thermogravimetric analysis (TGA) and using a fixed bed pyrolytic reactor (FBPR) at different temperatures. In addition, the influence of material bed thickness on the yield distribution and the composition of products was examined over a temperature range of 425–550°C. A higher wax fraction was obtained in the thin bed of the FBPR bed at 425°C. With temperature above 500°C, more oil and wax products were generated in the thick bed of the FBPR. Based on the experimental study, a discrete first‐order kinetic lumping model, comprising three independent parallel reactions (lumps), was developed to describe the yield distribution of gases, oil fractions, wax fractions, and solid residue, coupling with secondary cracking reactions of the wax fractions into lighter fractions (i.e., oil and gas). The overall apparent activation energy (Ea) and pre‐exponential factor (A0) of HDPE pyrolysis were estimated in the FBPR. The results showed that the thickness of the bed of plastics has a pronounced influence on the pyrolysis kinetics of HDPE. [ABSTRACT FROM AUTHOR]

Gas depletion results in shrinkage of the coal bed and hence in distortion of the stress–strain state near the face. The swelling of the coal is plotted against its yield of volatiles (its coalification). By randomization of the data, the shrinkage of the coal is expressed as a function of two variables: its yield of volatiles and its methane capacity. Knowing the gas depletion at the face and the dependence of the bed shrinkage on its methane capacity, we describe the variation in bed thickness as a function of the distance from the face. [ABSTRACT FROM AUTHOR]

The partitioning of different grain‐size classes in gravity flow deposits is one of the key characteristics used to infer depositional processes. Turbidites have relatively clean sandstones with most of their clay deposited as part of a mudstone cap or as a distal mudstone layer, whereas sand‐bearing debrites commonly comprise mixtures of sand grains and interstitial clay; hybrid event beds develop alternations of clean and dirty (clay‐rich) sandstones in varying proportions. Analysis of co‐genetic mudstone caps in terms of thickness and composition is a novel approach that can provide new insight into gravity flow depositional processes. Bed thickness data from the ponded Castagnola system show that turbidites contain more clay overall than do hybrid event beds. The Castagnola system is characterized by deposits of two very different petrographic types. Thanks to this duality, analyses of sandstone and mudstone composition allow inference of which proportion of the clay in each of the deposit types was acquired en route. In combination with standard sedimentological observations the new data allow insight into the likely characteristics of their parent flows. Clean turbidites were deposited by lower concentration, long duration, erosive, muddy turbidity currents which were more efficient at fractionating clay particles away from their basal layer. Hybrid event beds were deposited by shorter duration, higher‐concentration, less‐erosive sandier flows which were less efficient at clay fractionation. The results are consistent with data from other turbidite systems (for example, Marnoso‐arenacea). The approach represents a new method to infer the controls on the degree of clay partitioning in gravity flow deposits. [ABSTRACT FROM AUTHOR]

In the present study, the effect of biomass bed thickness and distance between successive beds on pyrolytic products yield were carried out. Sawdust of pine wood and sal wood, as well as husk of areca nut, were used as a biomass feedstock. To achieve maximum liquid yield, 500 °C temperature, 80 °C min−1 heating rate, 0.5 mm particle size and 100 mL min−1 gas flow rate was selected as optimum conditions. An equal amount of biomass was placed in six different bed arrangements while dividing the amount of biomass equally among the number of beds as well as keeping an equal distance between the successive beds. Further, the entire reactor was fitted inside the furnace so as to distribute the heat uniformly throughout the rector which also signified that each biomass bed has the same thermal profile at any time. It was found that liquid properties were better (lower viscosity, higher heating value) at fourth bed arrangement than in other bed arrangements. FTIR and GC-MS analysis confirmed the presence of aromatic, phenol, ester, ether, alcohol, acid, and amide groups. Gas chromatography also confirmed that with increasing temperature, the amount of hydrogen and hydrocarbons increased significantly while the formation of CO 2 was reduced. Image 1 • Effect of bed height and thickness on biomass pyrolytic products yields were studied. • Temperature, heating rate and particle size were optimized. • Optimization of bed arrangements resulted in higher and better liquid. • Complete characterization of pyrolytic oil was carried out. • Amounts of H 2 , HCs increased with increase in temperature whereas CO 2 reduced. [ABSTRACT FROM AUTHOR]

Results are given for reconstruction and modernization of sintering machine AKM-312/336 No. 7 of Iron and Steel Works ArcelorMittal Temirtau (previously Karaganda Metallurgical Combine). The sintering machine gas exhaust path is reconstructed: the first stage of the gas cleaning system is dismantled, i.e., the dirty gas collector, 28 TsN-15 cyclones and the scraper conveyor, and the semi-clean gas collector is replaced by an extended sectional collector with 32 dust chambers and two valve gates, under which a rubber conveyor is placed. The unit for loading sinter into the linear cooler is modernized. The planned number of multicyclone battery cyclones is restored (from 780 to 960) and a 'zero' vacuum chamber is added beneath the ignition hearth. Stationary throttling devices are installed in the zero and first vacuum chamber connecting pipes. As a result of reconstruction, the sintering area of the sintering machine increased from 336 to 348 m and the charge bed height is higher by 60 mm compared with the rest of the sintering machines, and according to data of May 2016 the specific productivity of the sintering machine is increased by 44.4%, gas consumption is reduced by 70%, and solid fuel for 2016 is reduced by 7.1% compared with the rest of the sintering machines. [ABSTRACT FROM AUTHOR]

Results are given for the reconstruction and modernization of sintering machine AKM-312/336 No. 7 of ArcelorMittal Temirtau (formerly Karaganda Metallurgical Combine). The gas exhaust conduit of the sinter machine is reconstructed: the first stage of the gas cleaning system within the composition of the 'dirty gas' collector, 28 TsN-15 cyclones and two scraper conveyers are dismantled, and the 'semiclean gas' collector with 32 dust chambers and two gate valves have been replaced, beneath which a rubber conveyer has been installed. The following have been modernized: a charge drum-mixer, two charge drum pelletizers, a charge loading assembly for the sinter machine, an ignition hearth, and an assembly for charging sinter into a linear cooler. A planned number of multicyclones (from 780 to 960) of two battery cyclones is restored, and a 'zero' vacuum chamber is installed beneath the ignition hearth. Stationary throttling devices are mounted within connections of the 'zero' and first vacuum chambers. The first batch of massive self-cleaning grates is manufactured and tested instead of the existing light grate bars. As a result of reconstruction and modernization, the sinter machine operating area is increased from 336 to 348 m, the charge layer from 380 to 450 mm, and sinter specific productivity is increased by ~40%; gas consumption is reduced by 70%, solid fuel consumption by 7% compared with other sinter machines. [ABSTRACT FROM AUTHOR]

The quality analysis of well-logging inversion results has always been an important part of formation evaluation. The precise calculation of hydrocarbon reserves requires the most accurate possible estimation of porosity, water saturation, and shale and rock-matrix volumes. The local inversion method conventionally used to predict the above model parameters depth by depth represents a marginally overdetermined inverse problem, which is rather sensitive to the uncertainty of observed data and limited in estimation accuracy. To reduce the harmful effect of data noise on the estimated model, we have suggested the interval inversion method, in which an increase of the overdetermination ratio allows a more accurate solution of the well-logging inverse problem. The interval inversion method inverts the data set of a longer depth interval to predict the vertical distributions of petrophysical parameters in a joint inversion procedure. In formulating the forward problem, we have extended the validity of probe response functions to a greater depth interval assuming the petrophysical parameters are depth dependent, and then we expanded the model parameters into a series using the Legendre polynomials as basis functions for modeling inhomogeneous formations. We solved the inverse problem for a much smaller number of expansion coefficients than data to derive the petrophysical parameters in a stable overdetermined inversion procedure. The added advantage of the interval inversion method is that the layer thicknesses and suitably chosen zone parameters can be estimated automatically by the inversion procedure to refine the results of inverse and forward modeling. We have defined depth-dependent model covariance and correlation matrices to compare the quality of the local and interval inversion results. A detailed study using well logs measured from a Hungarian gas-bearing unconsolidated formation revealed that the greatly overdetermined interval inversion procedure can be effectively used in reducing the estimation errors in shaly sand formations, which may refine significantly the results of reserve calculation. [ABSTRACT FROM AUTHOR]

Fracture networks in limestone and dolostone quarries in southern Belgium were analyzed as analogues to fractured subsurface Lower Carboniferous carbonates in the Campine-Brabant Basin (northern Belgium, southern Netherlands and westernmost Germany), which are considered as potential geothermal reservoirs. This study focuses on the difference in fracture density, intensity and connectivity in dolostone and limestone quarry walls, as well as on the relationship between bed thickness and fracture density/intensity. Bedding planes and fractures were interpreted based on orthorectified images of quarry walls. Statistical tests show that fracture density and intensity are significantly larger in the dolostones than in the limestones, which is explained by rock mechanical properties. Fracture connectivity is also highest in the studied dolostones. Interpreted bed thickness is significantly larger in limestones than dolostones, but no correlation is present between bed thickness and fracture density or intensity. This may be explained by the low percentage of bed-bounded fractures in the quarry walls. Fracture density, intensity and connectivity are key parameters influencing permeability, especially in carbonates with low matrix porosity. The results suggest that, in light of fracture properties, Lower Carboniferous dolostones might possess better geothermal reservoir characteristics than limestones. • Outcrop analogues to subsurface Lower Carboniferous carbonates (geothermal reservoir target) in northern Belgium were carefully selected. • Photogrammetry was used to digitize fracture patterns, which were statistically analyzed. • Fracture density, intensity and connectivity are significantly larger in the studied dolostones than in the limestones. • No correlation between bed thickness and fracture density or intensity is present. • Fracture intensity and connectivity can influence permeability, which makes the dolostones interesting from a reservoir perspective. [ABSTRACT FROM AUTHOR]

Siltation is a big hurdle in maintaining the required depth in and around port. Dredging is required in order to maintain the desired depths in the port. Dumping of dredged material has its own impact in the surrounding area and in turn its cost effectiveness. Studies for identification of dredged material dumping ground for development of a multipurpose terminal at Karanja were carried out. Four sets of dumping grounds were initially identified and their impact was observed at three different locations. MIKE 21HD with flexible mesh setup was used for the studies. Since the capital dredging would be going on for a period of six months, model simulations with MIKE 21 HD were done for a period of one month and then extrapolated for six months period. The impact of each dumping location for continuous dumping for a period of one month was assessed using the model simulations. The time required to restore the ambient conditions once the dumping is stopped was also examined. A comparison of the suspended sediment concentration was done at some locations in the vicinity of the dumping site. A comparison on the suspended sediment concentration and the bed thickness change at different points for the different dumping ground were observed. It was found that the suspended sediment concentration will fluctuate with the tide and will attain the lowest value of 5 ppt at the dumping location. The change in bed thickness is expected to be very marginal with maximum being of the order of 5 cm and the time required restoring the ambient conditions after the dumping ceases would be about 10 to 15 days. Based on this information location of the dumping ground could be finalised which has the minimum impact on the relevant area and is cost effective. [ABSTRACT FROM AUTHOR]

• Demonstration of a stator-rotor vortex chamber (STARVOC) • Improved solids loading and reduced gas consumption relative to GSVR. • Bed behavior and pressure drop investigated to characterize gas–solid hydrodynamics. The gas–solid vortex reactor (GSVR) has enormous process intensification potential. However the huge gas consumption can be a serious disadvantage for the GSVR in some applications such as fast pyrolysis. In this work, we demonstrate a recent novel design, where a stator-rotor vortex chamber (STARVOC) is driven by the fluid's kinetic energy, to decouple the solids bed rotation and gas. Gas-solid fluidization by using air and monosized aluminum balls was performed to investigate the hydrodynamics. A constructed fluidization flow regime map for a fixed solids loading of 100 g shows that the bed can only be fluidized for a rotation speed between 200 and 400 RPM. Below 200 RPM, particles settle down on the bottom plate and cannot form a stable bed due to inertia and friction. Above 400 RPM, the bed cannot be fluidized with superficial velocities up to 1.8 m/s (air flow rate of 90 Nm3/h). The bed thickness shows some non-uniformities, being smaller at the top of the bed than at the bottom counterpart. However by increasing the air flow rate or rotation speed the axial nonuniformity can be resolved. The bed pressure drop first increases with increasing gas flow rate and then levels off, showing similar characteristics as conventional fluidized beds. Theoretical pressure drops calculated from mathematical models such as Kao et al. model agree well with experimental measurements. Particle velocity discrepancies between the top and bottom particles reveal that the impact of gravity cannot be completely neglected. Design guidelines and possible applications for further development of STARVOC concept are proposed based on fundamental data provided in this work. [ABSTRACT FROM AUTHOR]

A recently introduced interpretation workflow has confirmed that inversion-based interpretation is more reliable than conventional well-log analysis in high-angle (HA) and horizontal (HZ) wells because the former accounts for well trajectory and shoulder-bed effects on well logs. Synthetic examples show that the inversion workflow could improve the estimation of hydrocarbon volumes by 15% and 10% in HA and HZ intervals, respectively. Using field examples of thinly interbedded calcite-cemented siltstone formations, we document results of the joint petrophysical inversion of logging-while-drilling multisector nuclear (neutron porosity, density, natural gamma ray, photoelectric factor) and multiarray propagation resistivity measurement for improved formation evaluation in HA/HZ wells. Under the assumption of multilayer formation petrophysical models, the inversion approach estimates formation properties by numerically reproducing the available measurements. Subsequently, inversion-derived hydrocarbon pore volume is calculated for assessment of reservoir pay. Application of the joint inversion-based interpretation in challenging field examples highlights petrophysical characteristics such as capillary trends or water saturation variations in a hydrocarbon column influenced by reservoir quality and formation electrical anisotropy which otherwise remain inconspicuous with conventional and quick-look interpretation of well-logs. [ABSTRACT FROM AUTHOR]

Abstract: A statistical evaluation of turbidite bed thickness was performed for 11 turbidite successions which constitute part of foreland basins formed along the Alpine fold and thrust belt of western and southeastern Greece. The purpose was to compare the results from this study with previously published investigations and discuss if and how statistical approaches could contribute to the environmental analysis of turbidite deposits in tectonically complex areas. Bed thickness datasets exhibit a clear non-normal signal in their distribution behavior. Statistical analysis was focused on: i) fitting of widely used non-normal theoretical distribution models using robust non-parametric goodness-of-fit statistical tests, and ii) detecting the possible presence of asymmetric bed thickness cycles and/or non-random bed thickness clustering. Results indicate that the studied bed thickness datasets are well characterized by a bimodal lognormal distribution model probably reflecting deposition from both high- and low-density turbidity currents. Several datasets exhibit distributions characterized by power law tails. Exponential distribution types were not observed. All datasets exhibit non-random thinning-upward bed thickness trends probably due to tectonically induced gravity flows. Proposed methods for identifying depositional sub-environments using turbidite bed thickness statistics were found to have limited applicability. Observations of the present study may prove useful for the environmental analysis of turbidite deposits in fold and thrust belt areas characterized by limited outcrop exposures. [Copyright &y& Elsevier]

Abstract: A common practice for characterizing uncertainty in coal resource assessments has been the itemization of tonnage at the mining unit level and the classification of such units according to distance to drilling holes. Distance criteria, such as those used in U.S. Geological Survey Circular 891, are still widely used for public disclosure. A major deficiency of distance methods is that they do not provide a quantitative measure of uncertainty. Additionally, relying on distance between data points alone does not take into consideration other factors known to have an influence on uncertainty, such as spatial correlation, type of probability distribution followed by the data, geological discontinuities, and boundary of the deposit. Several geostatistical methods have been combined to formulate a quantitative characterization for appraising uncertainty. Drill hole datasets ranging from widespread exploration drilling to detailed development drilling from a lignite deposit in Texas were used to illustrate the modeling. The results show that distance to the nearest drill hole is almost completely unrelated to uncertainty, which confirms the inadequacy of characterizing uncertainty based solely on a simple classification of resources by distance classes. The more complex statistical methods used in this study quantify uncertainty and show good agreement between confidence intervals in the uncertainty predictions and data from additional drilling. [ABSTRACT FROM AUTHOR]

Infrared (IR) radiation heating could provide a high heating rate and rapid moisture removal for rough rice drying. The objective of this research was to investigate the effect of the drying bed thickness on drying characteristics and quality of rough rice subjected to IR heating. Samples of freshly harvested medium grain rice (M202 variety) with 20.5% and 23.8%, (w.b.) moisture contents were used for this study. They were dried with two different radiation intensities (4685 and 5348 W m-2) and exposure times of 15, 30, 40, 60, 90, and 120 s for each drying bed thickness. The three tested drying bed thicknesses were single layer, 5 mm, and 10 mm. After IR drying, the samples were tempered for 4 h followed by natural cooling. The drying rate, moisture removal, and temperature of the rice were determined. The rice temperatures after the IR heating were its the range of 35.9 °C to 71.4 °C. The heating and drying rates decreased with the increase of bed thickness. Up to 2.2%, of moisture was removed during natural cooling after tempering, without additional energy input. IR heating under tested conditions did not have adverse effects on rice sensory and milling quality, including total rice yield, head rice yield, and degree of milling of the dried rice. We concluded that a high heating rate, fast drying, and good rice quality cats be achieved by IR heating of rough rice to about 60 °C followed by tempering and natural cooling with a tested bed thickness up to 10 mm. [ABSTRACT FROM AUTHOR]

Abstract: Refuge chamber is a kind of rescue equipment that protects trapped miners waiting for rescue in mine accidents. When a refuge chamber is in refuge state, carbon dioxide scrubbing is an important function of the environmental control system in chamber. In this paper, a series of experiments about the power consumption, purification efficiency, bed thickness and other factors of carbon dioxide scrubber in mine refuge chamber were carried out to obtain the optimal operating way. Then these parameters were testified by life supporting experiment in enclosed chamber. [Copyright &y& Elsevier]

Carbonate lithofacies thickness distributions are of fundamental importance to understanding shallow-water carbonate deposystems because they record evidence of the lateral distribution and migration of lithofacies elements, as well as evidence for the various other intrinsic and extrinsic controls on stratal geometries and accumulation rates. Previous analyses of lithofacies thickness data led to the suggestion that exponential distributions are ubiquitous in the ancient record. This has been interpreted to indicate deposition by stochastic Poisson process lithofacies mosaics. To further investigate these ideas statistical analysis of 56 outcrop and core examples was performed. The Kolmogorov-Smirnov test was used to identify the degree to which measured lithofacies thicknesses are well represented by a theoretical exponential distribution. Results from this analysis show that 16 of the 56 examples can be confidently shown to be exponential, while 28 are very probably not exponential. This indicates that stochastic Poisson processes are a plausible explanation for many carbonate successions, but they do not explain all of those tested here, suggesting that other non-Poisson processes, either stochastic or deterministic in nature, or both, must also be important. Thus lithofacies planform geometries, and the processes controlling vertical stacking in ancient carbonate platform top deposystems, were likely more diverse than has been suggested, requiring significant further quantitative analysis and numerical forward modeling to properly understand. [ABSTRACT FROM AUTHOR]

Turbidite bed thickness distributions are often interpreted in terms of power laws, even when there are significant departures from a single straight line on a log–log exceedence probability plot. Alternatively, these distributions have been described by a lognormal mixture model. Statistical methods used to analyse and distinguish the two models (power law and lognormal mixture) are presented here. In addition, the shortcomings of some frequently applied techniques are discussed, using a new data set from the Tarcău Sandstone of the East Carpathians, Romania, and published data from the Marnoso-Arenacea Formation of Italy. Log–log exceedence plots and least squares fitting by themselves are inappropriate tools for the analysis of bed thickness distributions; they must be accompanied by the assessment of other types of diagrams (cumulative probability, histogram of log-transformed values, q–q plots) and the use of a measure of goodness-of-fit other than R2, such as the chi-square or the Kolmogorov–Smirnov statistics. When interpreting data that do not follow a single straight line on a log–log exceedence plot, it is important to take into account that ‘segmented’ power laws are not simple mixtures of power law populations with arbitrary parameters. Although a simple model of flow confinement does result in segmented plots at the centre of a basin, the segmented shape of the exceedence curve breaks down as the sampling location moves away from the basin centre. The lognormal mixture model is a sedimentologically intuitive alternative to the power law distribution. The expectation–maximization algorithm can be used to estimate the parameters and thus to model lognormal bed thickness mixtures. Taking into account these observations, the bed thickness data from the Tarcău Sandstone are best described by a lognormal mixture model with two components. Compared with the Marnoso-Arenacea Formation, in which bed thicknesses of thin beds have a larger variability than thicknesses of the thicker beds, the thinner-bedded population of the Tarcău Sandstone has a lower variability than the thicker-bedded population. Such differences might reflect contrasting depositional settings, such as the difference between channel levées and basin plains. [ABSTRACT FROM AUTHOR]

A series of laboratory experiments on cohesive sediments under inorganic conditions was undertaken in order to evaluate the impact of fluid bed shear stress on the build-up of bed resistance to erosion with time. The importance of small pressures due to flowing water to increase bed strength is presented. It is also shown that the susceptibility of a cohesive bed to changes in its erodibility is related to deposited bed thickness due to sediment disturbance caused by dewatering from the consolidating bed. Laboratory experiments that use beds deposited from suspension should thus report the thickness of the bed prior to resuspension. [ABSTRACT FROM AUTHOR]

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The frequency distribution of turbidite thickness records information on flow hydrodynamics, initial sediment volumes and source migration and is an important component of petroleum reservoir models. However, the nature of this thickness distribution is currently uncertain, with log-normal or negative-exponential frequency distributions and power-law cumulative frequency distributions having been proposed by different authors. A detailed analysis of the Miocene Marnoso Arenacea Formation of the Italian Apennines shows that turbidite bed thickness and sand-interval thickness within each bed have a frequency distribution comprising the sum of a series of log-normal frequency distributions. These strata were deposited predominantly in a basin-plain setting, and bed amalgamation is relatively rare. Beds or sand intervals truncated by erosion were excluded from this analysis. Each log-normal frequency distribution characterizes bed or sand-interval thickness for a given basal grain-size or basal Bouma division. Measurements from the Silurian Aberystwyth Grits in Wales, the Cretaceous Great Valley Sequence in California and the Permian Karoo Basin in South Africa show that this conclusion holds for sequences of disparate age and variable location. The median thickness of these log-normal distributions is positively correlated with basal grain-size. The power-law exponent relating the basal grain-size and median thickness is different for turbidites with a basal A or B division and those with only C, D and E divisions. These two types of turbidite have been termed ‘thin bedded’ and ‘thick bedded’ by previous workers. A change in the power-law exponent is proposed to be related to: (i) a transition from viscous to inertial settling of sediment grains; and (ii) hindered settling at high sediment concentrations. The bimodal thickness distribution of ‘thin-bedded’ and ‘thick-bedded’ turbidites noted by previous... [ABSTRACT FROM AUTHOR]

Recent studies of turbidite bed thickness distributions have demonstrated power-law as well as log-normal statistical distributions. The different distributions may reflect different fan processes and environments and, therefore, could be used as a quantitative method to help identify those environments, including those devoid of sequential patterns. The cumulative distributions of well-known turbidite deposits spanning a range of interpreted fan subenvironments are used to illustrate the potential correlation between cumulative distribution and environments. Assuming that power-law distributions may, for some systems, be the primary input signal, one-dimensional modelling allows semi-quantitative characterization of the effects of different fan processes such as erosion and bed amalgamation. Environments indicative of different fan processes may be characterized based on the degree to which processes have acted as a ‘filter’ to modify the assumed power-law distribution systematically. This model of the effect of fan processes on the power-law distribution is used to help to account for bed thickness distributions observed in several field sites. [ABSTRACT FROM AUTHOR]

A stochastic model of bed thickness distribution is given. The following scheme of sedimentation and bed formation is assumed: ( 1) sedimentation consists of an unending sequence of alternating periods of deposition and erosion; ( 2) succession of sedimentary environments is described in terms of a transition probability matrix; ( 3) each depositional period accumulates a bed of sediments; ( 4) net accumulation exceeds erosion; ( 5) amounts of deposition and erosion are independent random variables. The equations for transformation of bed thickness distribution from sedimentary environment to geologic record are obtained. The sedimentological significance of these equations is discussed. [ABSTRACT FROM AUTHOR]

An extreme value model is developed for the situation where a cloud of sediment particles moves away from the boundary of a defined source area while undergoing constant depletion due to deposition of the larger particles. Taking the particles deposited at distance x from the source boundary to represent a distribution of largest extremes derived from a parent distribution of smallest extremes, it is possible to express the mean size of the deposited sediment in terms of the parameters of the original distribution at the source area. Thickness functions can be obtained as the product of expected diameter and particle frequency. If the spatial distribution f(x) of particle frequency along a linear transect can be inferred from a physical process, then this provides sufficient information for the construction of particle size and bed thickness prediction equations. Alternatively, the model places some restrictions on distribution selection if an empirical choice of f(x) is necessary. Some generalizations are obtained for trends in the mean and variance of the deposited particles on the basis of the hazard function of f(x). [ABSTRACT FROM AUTHOR]